diff options
Diffstat (limited to 'vendor/golang.org/x/tools')
82 files changed, 21238 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/LICENSE b/vendor/golang.org/x/tools/LICENSE new file mode 100644 index 0000000..6a66aea --- /dev/null +++ b/vendor/golang.org/x/tools/LICENSE @@ -0,0 +1,27 @@ +Copyright (c) 2009 The Go Authors. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/vendor/golang.org/x/tools/PATENTS b/vendor/golang.org/x/tools/PATENTS new file mode 100644 index 0000000..7330990 --- /dev/null +++ b/vendor/golang.org/x/tools/PATENTS @@ -0,0 +1,22 @@ +Additional IP Rights Grant (Patents) + +"This implementation" means the copyrightable works distributed by +Google as part of the Go project. + +Google hereby grants to You a perpetual, worldwide, non-exclusive, +no-charge, royalty-free, irrevocable (except as stated in this section) +patent license to make, have made, use, offer to sell, sell, import, +transfer and otherwise run, modify and propagate the contents of this +implementation of Go, where such license applies only to those patent +claims, both currently owned or controlled by Google and acquired in +the future, licensable by Google that are necessarily infringed by this +implementation of Go. This grant does not include claims that would be +infringed only as a consequence of further modification of this +implementation. If you or your agent or exclusive licensee institute or +order or agree to the institution of patent litigation against any +entity (including a cross-claim or counterclaim in a lawsuit) alleging +that this implementation of Go or any code incorporated within this +implementation of Go constitutes direct or contributory patent +infringement, or inducement of patent infringement, then any patent +rights granted to you under this License for this implementation of Go +shall terminate as of the date such litigation is filed. diff --git a/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go new file mode 100644 index 0000000..6b7052b --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go @@ -0,0 +1,627 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil + +// This file defines utilities for working with source positions. + +import ( + "fmt" + "go/ast" + "go/token" + "sort" +) + +// PathEnclosingInterval returns the node that encloses the source +// interval [start, end), and all its ancestors up to the AST root. +// +// The definition of "enclosing" used by this function considers +// additional whitespace abutting a node to be enclosed by it. +// In this example: +// +// z := x + y // add them +// <-A-> +// <----B-----> +// +// the ast.BinaryExpr(+) node is considered to enclose interval B +// even though its [Pos()..End()) is actually only interval A. +// This behaviour makes user interfaces more tolerant of imperfect +// input. +// +// This function treats tokens as nodes, though they are not included +// in the result. e.g. PathEnclosingInterval("+") returns the +// enclosing ast.BinaryExpr("x + y"). +// +// If start==end, the 1-char interval following start is used instead. +// +// The 'exact' result is true if the interval contains only path[0] +// and perhaps some adjacent whitespace. It is false if the interval +// overlaps multiple children of path[0], or if it contains only +// interior whitespace of path[0]. +// In this example: +// +// z := x + y // add them +// <--C--> <---E--> +// ^ +// D +// +// intervals C, D and E are inexact. C is contained by the +// z-assignment statement, because it spans three of its children (:=, +// x, +). So too is the 1-char interval D, because it contains only +// interior whitespace of the assignment. E is considered interior +// whitespace of the BlockStmt containing the assignment. +// +// Precondition: [start, end) both lie within the same file as root. +// TODO(adonovan): return (nil, false) in this case and remove precond. +// Requires FileSet; see loader.tokenFileContainsPos. +// +// Postcondition: path is never nil; it always contains at least 'root'. +// +func PathEnclosingInterval(root *ast.File, start, end token.Pos) (path []ast.Node, exact bool) { + // fmt.Printf("EnclosingInterval %d %d\n", start, end) // debugging + + // Precondition: node.[Pos..End) and adjoining whitespace contain [start, end). + var visit func(node ast.Node) bool + visit = func(node ast.Node) bool { + path = append(path, node) + + nodePos := node.Pos() + nodeEnd := node.End() + + // fmt.Printf("visit(%T, %d, %d)\n", node, nodePos, nodeEnd) // debugging + + // Intersect [start, end) with interval of node. + if start < nodePos { + start = nodePos + } + if end > nodeEnd { + end = nodeEnd + } + + // Find sole child that contains [start, end). + children := childrenOf(node) + l := len(children) + for i, child := range children { + // [childPos, childEnd) is unaugmented interval of child. + childPos := child.Pos() + childEnd := child.End() + + // [augPos, augEnd) is whitespace-augmented interval of child. + augPos := childPos + augEnd := childEnd + if i > 0 { + augPos = children[i-1].End() // start of preceding whitespace + } + if i < l-1 { + nextChildPos := children[i+1].Pos() + // Does [start, end) lie between child and next child? + if start >= augEnd && end <= nextChildPos { + return false // inexact match + } + augEnd = nextChildPos // end of following whitespace + } + + // fmt.Printf("\tchild %d: [%d..%d)\tcontains interval [%d..%d)?\n", + // i, augPos, augEnd, start, end) // debugging + + // Does augmented child strictly contain [start, end)? + if augPos <= start && end <= augEnd { + _, isToken := child.(tokenNode) + return isToken || visit(child) + } + + // Does [start, end) overlap multiple children? + // i.e. left-augmented child contains start + // but LR-augmented child does not contain end. + if start < childEnd && end > augEnd { + break + } + } + + // No single child contained [start, end), + // so node is the result. Is it exact? + + // (It's tempting to put this condition before the + // child loop, but it gives the wrong result in the + // case where a node (e.g. ExprStmt) and its sole + // child have equal intervals.) + if start == nodePos && end == nodeEnd { + return true // exact match + } + + return false // inexact: overlaps multiple children + } + + if start > end { + start, end = end, start + } + + if start < root.End() && end > root.Pos() { + if start == end { + end = start + 1 // empty interval => interval of size 1 + } + exact = visit(root) + + // Reverse the path: + for i, l := 0, len(path); i < l/2; i++ { + path[i], path[l-1-i] = path[l-1-i], path[i] + } + } else { + // Selection lies within whitespace preceding the + // first (or following the last) declaration in the file. + // The result nonetheless always includes the ast.File. + path = append(path, root) + } + + return +} + +// tokenNode is a dummy implementation of ast.Node for a single token. +// They are used transiently by PathEnclosingInterval but never escape +// this package. +// +type tokenNode struct { + pos token.Pos + end token.Pos +} + +func (n tokenNode) Pos() token.Pos { + return n.pos +} + +func (n tokenNode) End() token.Pos { + return n.end +} + +func tok(pos token.Pos, len int) ast.Node { + return tokenNode{pos, pos + token.Pos(len)} +} + +// childrenOf returns the direct non-nil children of ast.Node n. +// It may include fake ast.Node implementations for bare tokens. +// it is not safe to call (e.g.) ast.Walk on such nodes. +// +func childrenOf(n ast.Node) []ast.Node { + var children []ast.Node + + // First add nodes for all true subtrees. + ast.Inspect(n, func(node ast.Node) bool { + if node == n { // push n + return true // recur + } + if node != nil { // push child + children = append(children, node) + } + return false // no recursion + }) + + // Then add fake Nodes for bare tokens. + switch n := n.(type) { + case *ast.ArrayType: + children = append(children, + tok(n.Lbrack, len("[")), + tok(n.Elt.End(), len("]"))) + + case *ast.AssignStmt: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.BasicLit: + children = append(children, + tok(n.ValuePos, len(n.Value))) + + case *ast.BinaryExpr: + children = append(children, tok(n.OpPos, len(n.Op.String()))) + + case *ast.BlockStmt: + children = append(children, + tok(n.Lbrace, len("{")), + tok(n.Rbrace, len("}"))) + + case *ast.BranchStmt: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.CallExpr: + children = append(children, + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + if n.Ellipsis != 0 { + children = append(children, tok(n.Ellipsis, len("..."))) + } + + case *ast.CaseClause: + if n.List == nil { + children = append(children, + tok(n.Case, len("default"))) + } else { + children = append(children, + tok(n.Case, len("case"))) + } + children = append(children, tok(n.Colon, len(":"))) + + case *ast.ChanType: + switch n.Dir { + case ast.RECV: + children = append(children, tok(n.Begin, len("<-chan"))) + case ast.SEND: + children = append(children, tok(n.Begin, len("chan<-"))) + case ast.RECV | ast.SEND: + children = append(children, tok(n.Begin, len("chan"))) + } + + case *ast.CommClause: + if n.Comm == nil { + children = append(children, + tok(n.Case, len("default"))) + } else { + children = append(children, + tok(n.Case, len("case"))) + } + children = append(children, tok(n.Colon, len(":"))) + + case *ast.Comment: + // nop + + case *ast.CommentGroup: + // nop + + case *ast.CompositeLit: + children = append(children, + tok(n.Lbrace, len("{")), + tok(n.Rbrace, len("{"))) + + case *ast.DeclStmt: + // nop + + case *ast.DeferStmt: + children = append(children, + tok(n.Defer, len("defer"))) + + case *ast.Ellipsis: + children = append(children, + tok(n.Ellipsis, len("..."))) + + case *ast.EmptyStmt: + // nop + + case *ast.ExprStmt: + // nop + + case *ast.Field: + // TODO(adonovan): Field.{Doc,Comment,Tag}? + + case *ast.FieldList: + children = append(children, + tok(n.Opening, len("(")), + tok(n.Closing, len(")"))) + + case *ast.File: + // TODO test: Doc + children = append(children, + tok(n.Package, len("package"))) + + case *ast.ForStmt: + children = append(children, + tok(n.For, len("for"))) + + case *ast.FuncDecl: + // TODO(adonovan): FuncDecl.Comment? + + // Uniquely, FuncDecl breaks the invariant that + // preorder traversal yields tokens in lexical order: + // in fact, FuncDecl.Recv precedes FuncDecl.Type.Func. + // + // As a workaround, we inline the case for FuncType + // here and order things correctly. + // + children = nil // discard ast.Walk(FuncDecl) info subtrees + children = append(children, tok(n.Type.Func, len("func"))) + if n.Recv != nil { + children = append(children, n.Recv) + } + children = append(children, n.Name) + if n.Type.Params != nil { + children = append(children, n.Type.Params) + } + if n.Type.Results != nil { + children = append(children, n.Type.Results) + } + if n.Body != nil { + children = append(children, n.Body) + } + + case *ast.FuncLit: + // nop + + case *ast.FuncType: + if n.Func != 0 { + children = append(children, + tok(n.Func, len("func"))) + } + + case *ast.GenDecl: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + if n.Lparen != 0 { + children = append(children, + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + } + + case *ast.GoStmt: + children = append(children, + tok(n.Go, len("go"))) + + case *ast.Ident: + children = append(children, + tok(n.NamePos, len(n.Name))) + + case *ast.IfStmt: + children = append(children, + tok(n.If, len("if"))) + + case *ast.ImportSpec: + // TODO(adonovan): ImportSpec.{Doc,EndPos}? + + case *ast.IncDecStmt: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.IndexExpr: + children = append(children, + tok(n.Lbrack, len("{")), + tok(n.Rbrack, len("}"))) + + case *ast.InterfaceType: + children = append(children, + tok(n.Interface, len("interface"))) + + case *ast.KeyValueExpr: + children = append(children, + tok(n.Colon, len(":"))) + + case *ast.LabeledStmt: + children = append(children, + tok(n.Colon, len(":"))) + + case *ast.MapType: + children = append(children, + tok(n.Map, len("map"))) + + case *ast.ParenExpr: + children = append(children, + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + + case *ast.RangeStmt: + children = append(children, + tok(n.For, len("for")), + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.ReturnStmt: + children = append(children, + tok(n.Return, len("return"))) + + case *ast.SelectStmt: + children = append(children, + tok(n.Select, len("select"))) + + case *ast.SelectorExpr: + // nop + + case *ast.SendStmt: + children = append(children, + tok(n.Arrow, len("<-"))) + + case *ast.SliceExpr: + children = append(children, + tok(n.Lbrack, len("[")), + tok(n.Rbrack, len("]"))) + + case *ast.StarExpr: + children = append(children, tok(n.Star, len("*"))) + + case *ast.StructType: + children = append(children, tok(n.Struct, len("struct"))) + + case *ast.SwitchStmt: + children = append(children, tok(n.Switch, len("switch"))) + + case *ast.TypeAssertExpr: + children = append(children, + tok(n.Lparen-1, len(".")), + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + + case *ast.TypeSpec: + // TODO(adonovan): TypeSpec.{Doc,Comment}? + + case *ast.TypeSwitchStmt: + children = append(children, tok(n.Switch, len("switch"))) + + case *ast.UnaryExpr: + children = append(children, tok(n.OpPos, len(n.Op.String()))) + + case *ast.ValueSpec: + // TODO(adonovan): ValueSpec.{Doc,Comment}? + + case *ast.BadDecl, *ast.BadExpr, *ast.BadStmt: + // nop + } + + // TODO(adonovan): opt: merge the logic of ast.Inspect() into + // the switch above so we can make interleaved callbacks for + // both Nodes and Tokens in the right order and avoid the need + // to sort. + sort.Sort(byPos(children)) + + return children +} + +type byPos []ast.Node + +func (sl byPos) Len() int { + return len(sl) +} +func (sl byPos) Less(i, j int) bool { + return sl[i].Pos() < sl[j].Pos() +} +func (sl byPos) Swap(i, j int) { + sl[i], sl[j] = sl[j], sl[i] +} + +// NodeDescription returns a description of the concrete type of n suitable +// for a user interface. +// +// TODO(adonovan): in some cases (e.g. Field, FieldList, Ident, +// StarExpr) we could be much more specific given the path to the AST +// root. Perhaps we should do that. +// +func NodeDescription(n ast.Node) string { + switch n := n.(type) { + case *ast.ArrayType: + return "array type" + case *ast.AssignStmt: + return "assignment" + case *ast.BadDecl: + return "bad declaration" + case *ast.BadExpr: + return "bad expression" + case *ast.BadStmt: + return "bad statement" + case *ast.BasicLit: + return "basic literal" + case *ast.BinaryExpr: + return fmt.Sprintf("binary %s operation", n.Op) + case *ast.BlockStmt: + return "block" + case *ast.BranchStmt: + switch n.Tok { + case token.BREAK: + return "break statement" + case token.CONTINUE: + return "continue statement" + case token.GOTO: + return "goto statement" + case token.FALLTHROUGH: + return "fall-through statement" + } + case *ast.CallExpr: + if len(n.Args) == 1 && !n.Ellipsis.IsValid() { + return "function call (or conversion)" + } + return "function call" + case *ast.CaseClause: + return "case clause" + case *ast.ChanType: + return "channel type" + case *ast.CommClause: + return "communication clause" + case *ast.Comment: + return "comment" + case *ast.CommentGroup: + return "comment group" + case *ast.CompositeLit: + return "composite literal" + case *ast.DeclStmt: + return NodeDescription(n.Decl) + " statement" + case *ast.DeferStmt: + return "defer statement" + case *ast.Ellipsis: + return "ellipsis" + case *ast.EmptyStmt: + return "empty statement" + case *ast.ExprStmt: + return "expression statement" + case *ast.Field: + // Can be any of these: + // struct {x, y int} -- struct field(s) + // struct {T} -- anon struct field + // interface {I} -- interface embedding + // interface {f()} -- interface method + // func (A) func(B) C -- receiver, param(s), result(s) + return "field/method/parameter" + case *ast.FieldList: + return "field/method/parameter list" + case *ast.File: + return "source file" + case *ast.ForStmt: + return "for loop" + case *ast.FuncDecl: + return "function declaration" + case *ast.FuncLit: + return "function literal" + case *ast.FuncType: + return "function type" + case *ast.GenDecl: + switch n.Tok { + case token.IMPORT: + return "import declaration" + case token.CONST: + return "constant declaration" + case token.TYPE: + return "type declaration" + case token.VAR: + return "variable declaration" + } + case *ast.GoStmt: + return "go statement" + case *ast.Ident: + return "identifier" + case *ast.IfStmt: + return "if statement" + case *ast.ImportSpec: + return "import specification" + case *ast.IncDecStmt: + if n.Tok == token.INC { + return "increment statement" + } + return "decrement statement" + case *ast.IndexExpr: + return "index expression" + case *ast.InterfaceType: + return "interface type" + case *ast.KeyValueExpr: + return "key/value association" + case *ast.LabeledStmt: + return "statement label" + case *ast.MapType: + return "map type" + case *ast.Package: + return "package" + case *ast.ParenExpr: + return "parenthesized " + NodeDescription(n.X) + case *ast.RangeStmt: + return "range loop" + case *ast.ReturnStmt: + return "return statement" + case *ast.SelectStmt: + return "select statement" + case *ast.SelectorExpr: + return "selector" + case *ast.SendStmt: + return "channel send" + case *ast.SliceExpr: + return "slice expression" + case *ast.StarExpr: + return "*-operation" // load/store expr or pointer type + case *ast.StructType: + return "struct type" + case *ast.SwitchStmt: + return "switch statement" + case *ast.TypeAssertExpr: + return "type assertion" + case *ast.TypeSpec: + return "type specification" + case *ast.TypeSwitchStmt: + return "type switch" + case *ast.UnaryExpr: + return fmt.Sprintf("unary %s operation", n.Op) + case *ast.ValueSpec: + return "value specification" + + } + panic(fmt.Sprintf("unexpected node type: %T", n)) +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/enclosing_test.go b/vendor/golang.org/x/tools/go/ast/astutil/enclosing_test.go new file mode 100644 index 0000000..107f87c --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/enclosing_test.go @@ -0,0 +1,195 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil_test + +// This file defines tests of PathEnclosingInterval. + +// TODO(adonovan): exhaustive tests that run over the whole input +// tree, not just handcrafted examples. + +import ( + "bytes" + "fmt" + "go/ast" + "go/parser" + "go/token" + "strings" + "testing" + + "golang.org/x/tools/go/ast/astutil" +) + +// pathToString returns a string containing the concrete types of the +// nodes in path. +func pathToString(path []ast.Node) string { + var buf bytes.Buffer + fmt.Fprint(&buf, "[") + for i, n := range path { + if i > 0 { + fmt.Fprint(&buf, " ") + } + fmt.Fprint(&buf, strings.TrimPrefix(fmt.Sprintf("%T", n), "*ast.")) + } + fmt.Fprint(&buf, "]") + return buf.String() +} + +// findInterval parses input and returns the [start, end) positions of +// the first occurrence of substr in input. f==nil indicates failure; +// an error has already been reported in that case. +// +func findInterval(t *testing.T, fset *token.FileSet, input, substr string) (f *ast.File, start, end token.Pos) { + f, err := parser.ParseFile(fset, "<input>", input, 0) + if err != nil { + t.Errorf("parse error: %s", err) + return + } + + i := strings.Index(input, substr) + if i < 0 { + t.Errorf("%q is not a substring of input", substr) + f = nil + return + } + + filePos := fset.File(f.Package) + return f, filePos.Pos(i), filePos.Pos(i + len(substr)) +} + +// Common input for following tests. +const input = ` +// Hello. +package main +import "fmt" +func f() {} +func main() { + z := (x + y) // add them + f() // NB: ExprStmt and its CallExpr have same Pos/End +} +` + +func TestPathEnclosingInterval_Exact(t *testing.T) { + // For the exact tests, we check that a substring is mapped to + // the canonical string for the node it denotes. + tests := []struct { + substr string // first occurrence of this string indicates interval + node string // complete text of expected containing node + }{ + {"package", + input[11 : len(input)-1]}, + {"\npack", + input[11 : len(input)-1]}, + {"main", + "main"}, + {"import", + "import \"fmt\""}, + {"\"fmt\"", + "\"fmt\""}, + {"\nfunc f() {}\n", + "func f() {}"}, + {"x ", + "x"}, + {" y", + "y"}, + {"z", + "z"}, + {" + ", + "x + y"}, + {" :=", + "z := (x + y)"}, + {"x + y", + "x + y"}, + {"(x + y)", + "(x + y)"}, + {" (x + y) ", + "(x + y)"}, + {" (x + y) // add", + "(x + y)"}, + {"func", + "func f() {}"}, + {"func f() {}", + "func f() {}"}, + {"\nfun", + "func f() {}"}, + {" f", + "f"}, + } + for _, test := range tests { + f, start, end := findInterval(t, new(token.FileSet), input, test.substr) + if f == nil { + continue + } + + path, exact := astutil.PathEnclosingInterval(f, start, end) + if !exact { + t.Errorf("PathEnclosingInterval(%q) not exact", test.substr) + continue + } + + if len(path) == 0 { + if test.node != "" { + t.Errorf("PathEnclosingInterval(%q).path: got [], want %q", + test.substr, test.node) + } + continue + } + + if got := input[path[0].Pos():path[0].End()]; got != test.node { + t.Errorf("PathEnclosingInterval(%q): got %q, want %q (path was %s)", + test.substr, got, test.node, pathToString(path)) + continue + } + } +} + +func TestPathEnclosingInterval_Paths(t *testing.T) { + // For these tests, we check only the path of the enclosing + // node, but not its complete text because it's often quite + // large when !exact. + tests := []struct { + substr string // first occurrence of this string indicates interval + path string // the pathToString(),exact of the expected path + }{ + {"// add", + "[BlockStmt FuncDecl File],false"}, + {"(x + y", + "[ParenExpr AssignStmt BlockStmt FuncDecl File],false"}, + {"x +", + "[BinaryExpr ParenExpr AssignStmt BlockStmt FuncDecl File],false"}, + {"z := (x", + "[AssignStmt BlockStmt FuncDecl File],false"}, + {"func f", + "[FuncDecl File],false"}, + {"func f()", + "[FuncDecl File],false"}, + {" f()", + "[FuncDecl File],false"}, + {"() {}", + "[FuncDecl File],false"}, + {"// Hello", + "[File],false"}, + {" f", + "[Ident FuncDecl File],true"}, + {"func ", + "[FuncDecl File],true"}, + {"mai", + "[Ident File],true"}, + {"f() // NB", + "[CallExpr ExprStmt BlockStmt FuncDecl File],true"}, + } + for _, test := range tests { + f, start, end := findInterval(t, new(token.FileSet), input, test.substr) + if f == nil { + continue + } + + path, exact := astutil.PathEnclosingInterval(f, start, end) + if got := fmt.Sprintf("%s,%v", pathToString(path), exact); got != test.path { + t.Errorf("PathEnclosingInterval(%q): got %q, want %q", + test.substr, got, test.path) + continue + } + } +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/imports.go b/vendor/golang.org/x/tools/go/ast/astutil/imports.go new file mode 100644 index 0000000..83f196c --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/imports.go @@ -0,0 +1,470 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package astutil contains common utilities for working with the Go AST. +package astutil // import "golang.org/x/tools/go/ast/astutil" + +import ( + "fmt" + "go/ast" + "go/token" + "strconv" + "strings" +) + +// AddImport adds the import path to the file f, if absent. +func AddImport(fset *token.FileSet, f *ast.File, ipath string) (added bool) { + return AddNamedImport(fset, f, "", ipath) +} + +// AddNamedImport adds the import path to the file f, if absent. +// If name is not empty, it is used to rename the import. +// +// For example, calling +// AddNamedImport(fset, f, "pathpkg", "path") +// adds +// import pathpkg "path" +func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added bool) { + if imports(f, ipath) { + return false + } + + newImport := &ast.ImportSpec{ + Path: &ast.BasicLit{ + Kind: token.STRING, + Value: strconv.Quote(ipath), + }, + } + if name != "" { + newImport.Name = &ast.Ident{Name: name} + } + + // Find an import decl to add to. + // The goal is to find an existing import + // whose import path has the longest shared + // prefix with ipath. + var ( + bestMatch = -1 // length of longest shared prefix + lastImport = -1 // index in f.Decls of the file's final import decl + impDecl *ast.GenDecl // import decl containing the best match + impIndex = -1 // spec index in impDecl containing the best match + + isThirdPartyPath = isThirdParty(ipath) + ) + for i, decl := range f.Decls { + gen, ok := decl.(*ast.GenDecl) + if ok && gen.Tok == token.IMPORT { + lastImport = i + // Do not add to import "C", to avoid disrupting the + // association with its doc comment, breaking cgo. + if declImports(gen, "C") { + continue + } + + // Match an empty import decl if that's all that is available. + if len(gen.Specs) == 0 && bestMatch == -1 { + impDecl = gen + } + + // Compute longest shared prefix with imports in this group and find best + // matched import spec. + // 1. Always prefer import spec with longest shared prefix. + // 2. While match length is 0, + // - for stdlib package: prefer first import spec. + // - for third party package: prefer first third party import spec. + // We cannot use last import spec as best match for third party package + // because grouped imports are usually placed last by goimports -local + // flag. + // See issue #19190. + seenAnyThirdParty := false + for j, spec := range gen.Specs { + impspec := spec.(*ast.ImportSpec) + p := importPath(impspec) + n := matchLen(p, ipath) + if n > bestMatch || (bestMatch == 0 && !seenAnyThirdParty && isThirdPartyPath) { + bestMatch = n + impDecl = gen + impIndex = j + } + seenAnyThirdParty = seenAnyThirdParty || isThirdParty(p) + } + } + } + + // If no import decl found, add one after the last import. + if impDecl == nil { + impDecl = &ast.GenDecl{ + Tok: token.IMPORT, + } + if lastImport >= 0 { + impDecl.TokPos = f.Decls[lastImport].End() + } else { + // There are no existing imports. + // Our new import goes after the package declaration and after + // the comment, if any, that starts on the same line as the + // package declaration. + impDecl.TokPos = f.Package + + file := fset.File(f.Package) + pkgLine := file.Line(f.Package) + for _, c := range f.Comments { + if file.Line(c.Pos()) > pkgLine { + break + } + impDecl.TokPos = c.End() + } + } + f.Decls = append(f.Decls, nil) + copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:]) + f.Decls[lastImport+1] = impDecl + } + + // Insert new import at insertAt. + insertAt := 0 + if impIndex >= 0 { + // insert after the found import + insertAt = impIndex + 1 + } + impDecl.Specs = append(impDecl.Specs, nil) + copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:]) + impDecl.Specs[insertAt] = newImport + pos := impDecl.Pos() + if insertAt > 0 { + // If there is a comment after an existing import, preserve the comment + // position by adding the new import after the comment. + if spec, ok := impDecl.Specs[insertAt-1].(*ast.ImportSpec); ok && spec.Comment != nil { + pos = spec.Comment.End() + } else { + // Assign same position as the previous import, + // so that the sorter sees it as being in the same block. + pos = impDecl.Specs[insertAt-1].Pos() + } + } + if newImport.Name != nil { + newImport.Name.NamePos = pos + } + newImport.Path.ValuePos = pos + newImport.EndPos = pos + + // Clean up parens. impDecl contains at least one spec. + if len(impDecl.Specs) == 1 { + // Remove unneeded parens. + impDecl.Lparen = token.NoPos + } else if !impDecl.Lparen.IsValid() { + // impDecl needs parens added. + impDecl.Lparen = impDecl.Specs[0].Pos() + } + + f.Imports = append(f.Imports, newImport) + + if len(f.Decls) <= 1 { + return true + } + + // Merge all the import declarations into the first one. + var first *ast.GenDecl + for i := 0; i < len(f.Decls); i++ { + decl := f.Decls[i] + gen, ok := decl.(*ast.GenDecl) + if !ok || gen.Tok != token.IMPORT || declImports(gen, "C") { + continue + } + if first == nil { + first = gen + continue // Don't touch the first one. + } + // We now know there is more than one package in this import + // declaration. Ensure that it ends up parenthesized. + first.Lparen = first.Pos() + // Move the imports of the other import declaration to the first one. + for _, spec := range gen.Specs { + spec.(*ast.ImportSpec).Path.ValuePos = first.Pos() + first.Specs = append(first.Specs, spec) + } + f.Decls = append(f.Decls[:i], f.Decls[i+1:]...) + i-- + } + + return true +} + +func isThirdParty(importPath string) bool { + // Third party package import path usually contains "." (".com", ".org", ...) + // This logic is taken from golang.org/x/tools/imports package. + return strings.Contains(importPath, ".") +} + +// DeleteImport deletes the import path from the file f, if present. +func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) { + return DeleteNamedImport(fset, f, "", path) +} + +// DeleteNamedImport deletes the import with the given name and path from the file f, if present. +func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (deleted bool) { + var delspecs []*ast.ImportSpec + var delcomments []*ast.CommentGroup + + // Find the import nodes that import path, if any. + for i := 0; i < len(f.Decls); i++ { + decl := f.Decls[i] + gen, ok := decl.(*ast.GenDecl) + if !ok || gen.Tok != token.IMPORT { + continue + } + for j := 0; j < len(gen.Specs); j++ { + spec := gen.Specs[j] + impspec := spec.(*ast.ImportSpec) + if impspec.Name == nil && name != "" { + continue + } + if impspec.Name != nil && impspec.Name.Name != name { + continue + } + if importPath(impspec) != path { + continue + } + + // We found an import spec that imports path. + // Delete it. + delspecs = append(delspecs, impspec) + deleted = true + copy(gen.Specs[j:], gen.Specs[j+1:]) + gen.Specs = gen.Specs[:len(gen.Specs)-1] + + // If this was the last import spec in this decl, + // delete the decl, too. + if len(gen.Specs) == 0 { + copy(f.Decls[i:], f.Decls[i+1:]) + f.Decls = f.Decls[:len(f.Decls)-1] + i-- + break + } else if len(gen.Specs) == 1 { + if impspec.Doc != nil { + delcomments = append(delcomments, impspec.Doc) + } + if impspec.Comment != nil { + delcomments = append(delcomments, impspec.Comment) + } + for _, cg := range f.Comments { + // Found comment on the same line as the import spec. + if cg.End() < impspec.Pos() && fset.Position(cg.End()).Line == fset.Position(impspec.Pos()).Line { + delcomments = append(delcomments, cg) + break + } + } + + spec := gen.Specs[0].(*ast.ImportSpec) + + // Move the documentation right after the import decl. + if spec.Doc != nil { + for fset.Position(gen.TokPos).Line+1 < fset.Position(spec.Doc.Pos()).Line { + fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line) + } + } + for _, cg := range f.Comments { + if cg.End() < spec.Pos() && fset.Position(cg.End()).Line == fset.Position(spec.Pos()).Line { + for fset.Position(gen.TokPos).Line+1 < fset.Position(spec.Pos()).Line { + fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line) + } + break + } + } + } + if j > 0 { + lastImpspec := gen.Specs[j-1].(*ast.ImportSpec) + lastLine := fset.Position(lastImpspec.Path.ValuePos).Line + line := fset.Position(impspec.Path.ValuePos).Line + + // We deleted an entry but now there may be + // a blank line-sized hole where the import was. + if line-lastLine > 1 { + // There was a blank line immediately preceding the deleted import, + // so there's no need to close the hole. + // Do nothing. + } else if line != fset.File(gen.Rparen).LineCount() { + // There was no blank line. Close the hole. + fset.File(gen.Rparen).MergeLine(line) + } + } + j-- + } + } + + // Delete imports from f.Imports. + for i := 0; i < len(f.Imports); i++ { + imp := f.Imports[i] + for j, del := range delspecs { + if imp == del { + copy(f.Imports[i:], f.Imports[i+1:]) + f.Imports = f.Imports[:len(f.Imports)-1] + copy(delspecs[j:], delspecs[j+1:]) + delspecs = delspecs[:len(delspecs)-1] + i-- + break + } + } + } + + // Delete comments from f.Comments. + for i := 0; i < len(f.Comments); i++ { + cg := f.Comments[i] + for j, del := range delcomments { + if cg == del { + copy(f.Comments[i:], f.Comments[i+1:]) + f.Comments = f.Comments[:len(f.Comments)-1] + copy(delcomments[j:], delcomments[j+1:]) + delcomments = delcomments[:len(delcomments)-1] + i-- + break + } + } + } + + if len(delspecs) > 0 { + panic(fmt.Sprintf("deleted specs from Decls but not Imports: %v", delspecs)) + } + + return +} + +// RewriteImport rewrites any import of path oldPath to path newPath. +func RewriteImport(fset *token.FileSet, f *ast.File, oldPath, newPath string) (rewrote bool) { + for _, imp := range f.Imports { + if importPath(imp) == oldPath { + rewrote = true + // record old End, because the default is to compute + // it using the length of imp.Path.Value. + imp.EndPos = imp.End() + imp.Path.Value = strconv.Quote(newPath) + } + } + return +} + +// UsesImport reports whether a given import is used. +func UsesImport(f *ast.File, path string) (used bool) { + spec := importSpec(f, path) + if spec == nil { + return + } + + name := spec.Name.String() + switch name { + case "<nil>": + // If the package name is not explicitly specified, + // make an educated guess. This is not guaranteed to be correct. + lastSlash := strings.LastIndex(path, "/") + if lastSlash == -1 { + name = path + } else { + name = path[lastSlash+1:] + } + case "_", ".": + // Not sure if this import is used - err on the side of caution. + return true + } + + ast.Walk(visitFn(func(n ast.Node) { + sel, ok := n.(*ast.SelectorExpr) + if ok && isTopName(sel.X, name) { + used = true + } + }), f) + + return +} + +type visitFn func(node ast.Node) + +func (fn visitFn) Visit(node ast.Node) ast.Visitor { + fn(node) + return fn +} + +// imports returns true if f imports path. +func imports(f *ast.File, path string) bool { + return importSpec(f, path) != nil +} + +// importSpec returns the import spec if f imports path, +// or nil otherwise. +func importSpec(f *ast.File, path string) *ast.ImportSpec { + for _, s := range f.Imports { + if importPath(s) == path { + return s + } + } + return nil +} + +// importPath returns the unquoted import path of s, +// or "" if the path is not properly quoted. +func importPath(s *ast.ImportSpec) string { + t, err := strconv.Unquote(s.Path.Value) + if err == nil { + return t + } + return "" +} + +// declImports reports whether gen contains an import of path. +func declImports(gen *ast.GenDecl, path string) bool { + if gen.Tok != token.IMPORT { + return false + } + for _, spec := range gen.Specs { + impspec := spec.(*ast.ImportSpec) + if importPath(impspec) == path { + return true + } + } + return false +} + +// matchLen returns the length of the longest path segment prefix shared by x and y. +func matchLen(x, y string) int { + n := 0 + for i := 0; i < len(x) && i < len(y) && x[i] == y[i]; i++ { + if x[i] == '/' { + n++ + } + } + return n +} + +// isTopName returns true if n is a top-level unresolved identifier with the given name. +func isTopName(n ast.Expr, name string) bool { + id, ok := n.(*ast.Ident) + return ok && id.Name == name && id.Obj == nil +} + +// Imports returns the file imports grouped by paragraph. +func Imports(fset *token.FileSet, f *ast.File) [][]*ast.ImportSpec { + var groups [][]*ast.ImportSpec + + for _, decl := range f.Decls { + genDecl, ok := decl.(*ast.GenDecl) + if !ok || genDecl.Tok != token.IMPORT { + break + } + + group := []*ast.ImportSpec{} + + var lastLine int + for _, spec := range genDecl.Specs { + importSpec := spec.(*ast.ImportSpec) + pos := importSpec.Path.ValuePos + line := fset.Position(pos).Line + if lastLine > 0 && pos > 0 && line-lastLine > 1 { + groups = append(groups, group) + group = []*ast.ImportSpec{} + } + group = append(group, importSpec) + lastLine = line + } + groups = append(groups, group) + } + + return groups +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/imports_test.go b/vendor/golang.org/x/tools/go/ast/astutil/imports_test.go new file mode 100644 index 0000000..8bc3480 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/imports_test.go @@ -0,0 +1,1818 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil + +import ( + "bytes" + "go/ast" + "go/format" + "go/parser" + "go/token" + "reflect" + "strconv" + "testing" +) + +var fset = token.NewFileSet() + +func parse(t *testing.T, name, in string) *ast.File { + file, err := parser.ParseFile(fset, name, in, parser.ParseComments) + if err != nil { + t.Fatalf("%s parse: %v", name, err) + } + return file +} + +func print(t *testing.T, name string, f *ast.File) string { + var buf bytes.Buffer + if err := format.Node(&buf, fset, f); err != nil { + t.Fatalf("%s gofmt: %v", name, err) + } + return string(buf.Bytes()) +} + +type test struct { + name string + renamedPkg string + pkg string + in string + out string + broken bool // known broken +} + +var addTests = []test{ + { + name: "leave os alone", + pkg: "os", + in: `package main + +import ( + "os" +) +`, + out: `package main + +import ( + "os" +) +`, + }, + { + name: "import.1", + pkg: "os", + in: `package main +`, + out: `package main + +import "os" +`, + }, + { + name: "import.2", + pkg: "os", + in: `package main + +// Comment +import "C" +`, + out: `package main + +// Comment +import "C" +import "os" +`, + }, + { + name: "import.3", + pkg: "os", + in: `package main + +// Comment +import "C" + +import ( + "io" + "utf8" +) +`, + out: `package main + +// Comment +import "C" + +import ( + "io" + "os" + "utf8" +) +`, + }, + { + name: "import.17", + pkg: "x/y/z", + in: `package main + +// Comment +import "C" + +import ( + "a" + "b" + + "x/w" + + "d/f" +) +`, + out: `package main + +// Comment +import "C" + +import ( + "a" + "b" + + "x/w" + "x/y/z" + + "d/f" +) +`, + }, + { + name: "issue #19190", + pkg: "x.org/y/z", + in: `package main + +// Comment +import "C" + +import ( + "bytes" + "os" + + "d.com/f" +) +`, + out: `package main + +// Comment +import "C" + +import ( + "bytes" + "os" + + "d.com/f" + "x.org/y/z" +) +`, + }, + { + name: "issue #19190 with existing grouped import packages", + pkg: "x.org/y/z", + in: `package main + +// Comment +import "C" + +import ( + "bytes" + "os" + + "c.com/f" + "d.com/f" + + "y.com/a" + "y.com/b" + "y.com/c" +) +`, + out: `package main + +// Comment +import "C" + +import ( + "bytes" + "os" + + "c.com/f" + "d.com/f" + "x.org/y/z" + + "y.com/a" + "y.com/b" + "y.com/c" +) +`, + }, + { + name: "issue #19190 - match score is still respected", + pkg: "y.org/c", + in: `package main + +import ( + "x.org/a" + + "y.org/b" +) +`, + out: `package main + +import ( + "x.org/a" + + "y.org/b" + "y.org/c" +) +`, + }, + { + name: "import into singular group", + pkg: "bytes", + in: `package main + +import "os" + +`, + out: `package main + +import ( + "bytes" + "os" +) +`, + }, + { + name: "import into singular group with comment", + pkg: "bytes", + in: `package main + +import /* why */ /* comment here? */ "os" + +`, + out: `package main + +import /* why */ /* comment here? */ ( + "bytes" + "os" +) +`, + }, + { + name: "import into group with leading comment", + pkg: "strings", + in: `package main + +import ( + // comment before bytes + "bytes" + "os" +) + +`, + out: `package main + +import ( + // comment before bytes + "bytes" + "os" + "strings" +) +`, + }, + { + name: "", + renamedPkg: "fmtpkg", + pkg: "fmt", + in: `package main + +import "os" + +`, + out: `package main + +import ( + fmtpkg "fmt" + "os" +) +`, + }, + { + name: "struct comment", + pkg: "time", + in: `package main + +// This is a comment before a struct. +type T struct { + t time.Time +} +`, + out: `package main + +import "time" + +// This is a comment before a struct. +type T struct { + t time.Time +} +`, + }, + { + name: "issue 8729 import C", + pkg: "time", + in: `package main + +import "C" + +// comment +type T time.Time +`, + out: `package main + +import "C" +import "time" + +// comment +type T time.Time +`, + }, + { + name: "issue 8729 empty import", + pkg: "time", + in: `package main + +import () + +// comment +type T time.Time +`, + out: `package main + +import "time" + +// comment +type T time.Time +`, + }, + { + name: "issue 8729 comment on package line", + pkg: "time", + in: `package main // comment + +type T time.Time +`, + out: `package main // comment +import "time" + +type T time.Time +`, + }, + { + name: "issue 8729 comment after package", + pkg: "time", + in: `package main +// comment + +type T time.Time +`, + out: `package main + +import "time" + +// comment + +type T time.Time +`, + }, + { + name: "issue 8729 comment before and on package line", + pkg: "time", + in: `// comment before +package main // comment on + +type T time.Time +`, + out: `// comment before +package main // comment on +import "time" + +type T time.Time +`, + }, + + // Issue 9961: Match prefixes using path segments rather than bytes + { + name: "issue 9961", + pkg: "regexp", + in: `package main + +import ( + "flag" + "testing" + + "rsc.io/p" +) +`, + out: `package main + +import ( + "flag" + "regexp" + "testing" + + "rsc.io/p" +) +`, + }, + // Issue 10337: Preserve comment position + { + name: "issue 10337", + pkg: "fmt", + in: `package main + +import ( + "bytes" // a + "log" // c +) +`, + out: `package main + +import ( + "bytes" // a + "fmt" + "log" // c +) +`, + }, + { + name: "issue 10337 new import at the start", + pkg: "bytes", + in: `package main + +import ( + "fmt" // b + "log" // c +) +`, + out: `package main + +import ( + "bytes" + "fmt" // b + "log" // c +) +`, + }, + { + name: "issue 10337 new import at the end", + pkg: "log", + in: `package main + +import ( + "bytes" // a + "fmt" // b +) +`, + out: `package main + +import ( + "bytes" // a + "fmt" // b + "log" +) +`, + }, + // Issue 14075: Merge import declarations + { + name: "issue 14075", + pkg: "bufio", + in: `package main + +import "bytes" +import "fmt" +`, + out: `package main + +import ( + "bufio" + "bytes" + "fmt" +) +`, + }, + { + name: "issue 14075 update position", + pkg: "bufio", + in: `package main + +import "bytes" +import ( + "fmt" +) +`, + out: `package main + +import ( + "bufio" + "bytes" + "fmt" +) +`, + }, + { + name: `issue 14075 ignore import "C"`, + pkg: "bufio", + in: `package main + +// Comment +import "C" + +import "bytes" +import "fmt" +`, + out: `package main + +// Comment +import "C" + +import ( + "bufio" + "bytes" + "fmt" +) +`, + }, + { + name: `issue 14075 ignore adjacent import "C"`, + pkg: "bufio", + in: `package main + +// Comment +import "C" +import "fmt" +`, + out: `package main + +// Comment +import "C" +import ( + "bufio" + "fmt" +) +`, + }, + { + name: `issue 14075 ignore adjacent import "C" (without factored import)`, + pkg: "bufio", + in: `package main + +// Comment +import "C" +import "fmt" +`, + out: `package main + +// Comment +import "C" +import ( + "bufio" + "fmt" +) +`, + }, + { + name: `issue 14075 ignore single import "C"`, + pkg: "bufio", + in: `package main + +// Comment +import "C" +`, + out: `package main + +// Comment +import "C" +import "bufio" +`, + }, + { + name: `issue 17212 several single-import lines with shared prefix ending in a slash`, + pkg: "net/http", + in: `package main + +import "bufio" +import "net/url" +`, + out: `package main + +import ( + "bufio" + "net/http" + "net/url" +) +`, + }, + { + name: `issue 17212 block imports lines with shared prefix ending in a slash`, + pkg: "net/http", + in: `package main + +import ( + "bufio" + "net/url" +) +`, + out: `package main + +import ( + "bufio" + "net/http" + "net/url" +) +`, + }, + { + name: `issue 17213 many single-import lines`, + pkg: "fmt", + in: `package main + +import "bufio" +import "bytes" +import "errors" +`, + out: `package main + +import ( + "bufio" + "bytes" + "errors" + "fmt" +) +`, + }, +} + +func TestAddImport(t *testing.T) { + for _, test := range addTests { + file := parse(t, test.name, test.in) + var before bytes.Buffer + ast.Fprint(&before, fset, file, nil) + AddNamedImport(fset, file, test.renamedPkg, test.pkg) + if got := print(t, test.name, file); got != test.out { + if test.broken { + t.Logf("%s is known broken:\ngot: %s\nwant: %s", test.name, got, test.out) + } else { + t.Errorf("%s:\ngot: %s\nwant: %s", test.name, got, test.out) + } + var after bytes.Buffer + ast.Fprint(&after, fset, file, nil) + + t.Logf("AST before:\n%s\nAST after:\n%s\n", before.String(), after.String()) + } + } +} + +func TestDoubleAddImport(t *testing.T) { + file := parse(t, "doubleimport", "package main\n") + AddImport(fset, file, "os") + AddImport(fset, file, "bytes") + want := `package main + +import ( + "bytes" + "os" +) +` + if got := print(t, "doubleimport", file); got != want { + t.Errorf("got: %s\nwant: %s", got, want) + } +} + +func TestDoubleAddNamedImport(t *testing.T) { + file := parse(t, "doublenamedimport", "package main\n") + AddNamedImport(fset, file, "o", "os") + AddNamedImport(fset, file, "i", "io") + want := `package main + +import ( + i "io" + o "os" +) +` + if got := print(t, "doublenamedimport", file); got != want { + t.Errorf("got: %s\nwant: %s", got, want) + } +} + +// Part of issue 8729. +func TestDoubleAddImportWithDeclComment(t *testing.T) { + file := parse(t, "doubleimport", `package main + +import ( +) + +// comment +type I int +`) + // The AddImport order here matters. + AddImport(fset, file, "golang.org/x/tools/go/ast/astutil") + AddImport(fset, file, "os") + want := `package main + +import ( + "golang.org/x/tools/go/ast/astutil" + "os" +) + +// comment +type I int +` + if got := print(t, "doubleimport_with_decl_comment", file); got != want { + t.Errorf("got: %s\nwant: %s", got, want) + } +} + +var deleteTests = []test{ + { + name: "import.4", + pkg: "os", + in: `package main + +import ( + "os" +) +`, + out: `package main +`, + }, + { + name: "import.5", + pkg: "os", + in: `package main + +// Comment +import "C" +import "os" +`, + out: `package main + +// Comment +import "C" +`, + }, + { + name: "import.6", + pkg: "os", + in: `package main + +// Comment +import "C" + +import ( + "io" + "os" + "utf8" +) +`, + out: `package main + +// Comment +import "C" + +import ( + "io" + "utf8" +) +`, + }, + { + name: "import.7", + pkg: "io", + in: `package main + +import ( + "io" // a + "os" // b + "utf8" // c +) +`, + out: `package main + +import ( + // a + "os" // b + "utf8" // c +) +`, + }, + { + name: "import.8", + pkg: "os", + in: `package main + +import ( + "io" // a + "os" // b + "utf8" // c +) +`, + out: `package main + +import ( + "io" // a + // b + "utf8" // c +) +`, + }, + { + name: "import.9", + pkg: "utf8", + in: `package main + +import ( + "io" // a + "os" // b + "utf8" // c +) +`, + out: `package main + +import ( + "io" // a + "os" // b + // c +) +`, + }, + { + name: "import.10", + pkg: "io", + in: `package main + +import ( + "io" + "os" + "utf8" +) +`, + out: `package main + +import ( + "os" + "utf8" +) +`, + }, + { + name: "import.11", + pkg: "os", + in: `package main + +import ( + "io" + "os" + "utf8" +) +`, + out: `package main + +import ( + "io" + "utf8" +) +`, + }, + { + name: "import.12", + pkg: "utf8", + in: `package main + +import ( + "io" + "os" + "utf8" +) +`, + out: `package main + +import ( + "io" + "os" +) +`, + }, + { + name: "handle.raw.quote.imports", + pkg: "os", + in: "package main\n\nimport `os`", + out: `package main +`, + }, + { + name: "import.13", + pkg: "io", + in: `package main + +import ( + "fmt" + + "io" + "os" + "utf8" + + "go/format" +) +`, + out: `package main + +import ( + "fmt" + + "os" + "utf8" + + "go/format" +) +`, + }, + { + name: "import.14", + pkg: "io", + in: `package main + +import ( + "fmt" // a + + "io" // b + "os" // c + "utf8" // d + + "go/format" // e +) +`, + out: `package main + +import ( + "fmt" // a + + // b + "os" // c + "utf8" // d + + "go/format" // e +) +`, + }, + { + name: "import.15", + pkg: "double", + in: `package main + +import ( + "double" + "double" +) +`, + out: `package main +`, + }, + { + name: "import.16", + pkg: "bubble", + in: `package main + +import ( + "toil" + "bubble" + "bubble" + "trouble" +) +`, + out: `package main + +import ( + "toil" + "trouble" +) +`, + }, + { + name: "import.17", + pkg: "quad", + in: `package main + +import ( + "quad" + "quad" +) + +import ( + "quad" + "quad" +) +`, + out: `package main +`, + }, + { + name: "import.18", + renamedPkg: "x", + pkg: "fmt", + in: `package main + +import ( + "fmt" + x "fmt" +) +`, + out: `package main + +import ( + "fmt" +) +`, + }, + { + name: "import.18", + renamedPkg: "x", + pkg: "fmt", + in: `package main + +import x "fmt" +import y "fmt" +`, + out: `package main + +import y "fmt" +`, + }, + // Issue #15432, #18051 + { + name: "import.19", + pkg: "fmt", + in: `package main + +import ( + "fmt" + + // Some comment. + "io" +)`, + out: `package main + +import ( + // Some comment. + "io" +) +`, + }, + { + name: "import.20", + pkg: "fmt", + in: `package main + +import ( + "fmt" + + // Some + // comment. + "io" +)`, + out: `package main + +import ( + // Some + // comment. + "io" +) +`, + }, + { + name: "import.21", + pkg: "fmt", + in: `package main + +import ( + "fmt" + + /* + Some + comment. + */ + "io" +)`, + out: `package main + +import ( + /* + Some + comment. + */ + "io" +) +`, + }, + { + name: "import.22", + pkg: "fmt", + in: `package main + +import ( + /* Some */ + // comment. + "io" + "fmt" +)`, + out: `package main + +import ( + /* Some */ + // comment. + "io" +) +`, + }, + { + name: "import.23", + pkg: "fmt", + in: `package main + +import ( + // comment 1 + "fmt" + // comment 2 + "io" +)`, + out: `package main + +import ( + // comment 2 + "io" +) +`, + }, + { + name: "import.24", + pkg: "fmt", + in: `package main + +import ( + "fmt" // comment 1 + "io" // comment 2 +)`, + out: `package main + +import ( + "io" // comment 2 +) +`, + }, + { + name: "import.25", + pkg: "fmt", + in: `package main + +import ( + "fmt" + /* comment */ "io" +)`, + out: `package main + +import ( + /* comment */ "io" +) +`, + }, + { + name: "import.26", + pkg: "fmt", + in: `package main + +import ( + "fmt" + "io" /* comment */ +)`, + out: `package main + +import ( + "io" /* comment */ +) +`, + }, + { + name: "import.27", + pkg: "fmt", + in: `package main + +import ( + "fmt" /* comment */ + "io" +)`, + out: `package main + +import ( + "io" +) +`, + }, + { + name: "import.28", + pkg: "fmt", + in: `package main + +import ( + /* comment */ "fmt" + "io" +)`, + out: `package main + +import ( + "io" +) +`, + }, + { + name: "import.29", + pkg: "fmt", + in: `package main + +// comment 1 +import ( + "fmt" + "io" // comment 2 +)`, + out: `package main + +// comment 1 +import ( + "io" // comment 2 +) +`, + }, + { + name: "import.30", + pkg: "fmt", + in: `package main + +// comment 1 +import ( + "fmt" // comment 2 + "io" +)`, + out: `package main + +// comment 1 +import ( + "io" +) +`, + }, + { + name: "import.31", + pkg: "fmt", + in: `package main + +// comment 1 +import ( + "fmt" + /* comment 2 */ "io" +)`, + out: `package main + +// comment 1 +import ( + /* comment 2 */ "io" +) +`, + }, + { + name: "import.32", + pkg: "fmt", + renamedPkg: "f", + in: `package main + +// comment 1 +import ( + f "fmt" + /* comment 2 */ i "io" +)`, + out: `package main + +// comment 1 +import ( + /* comment 2 */ i "io" +) +`, + }, + { + name: "import.33", + pkg: "fmt", + renamedPkg: "f", + in: `package main + +// comment 1 +import ( + /* comment 2 */ f "fmt" + i "io" +)`, + out: `package main + +// comment 1 +import ( + i "io" +) +`, + }, + { + name: "import.34", + pkg: "fmt", + renamedPkg: "f", + in: `package main + +// comment 1 +import ( + f "fmt" /* comment 2 */ + i "io" +)`, + out: `package main + +// comment 1 +import ( + i "io" +) +`, + }, + { + name: "import.35", + pkg: "fmt", + in: `package main + +// comment 1 +import ( + "fmt" + // comment 2 + "io" +)`, + out: `package main + +// comment 1 +import ( + // comment 2 + "io" +) +`, + }, + { + name: "import.36", + pkg: "fmt", + in: `package main + +/* comment 1 */ +import ( + "fmt" + /* comment 2 */ + "io" +)`, + out: `package main + +/* comment 1 */ +import ( + /* comment 2 */ + "io" +) +`, + }, + + // Issue 20229: MergeLine panic on weird input + { + name: "import.37", + pkg: "io", + in: `package main +import("_" +"io")`, + out: `package main + +import ( + "_" +) +`, + }, +} + +func TestDeleteImport(t *testing.T) { + for _, test := range deleteTests { + file := parse(t, test.name, test.in) + DeleteNamedImport(fset, file, test.renamedPkg, test.pkg) + if got := print(t, test.name, file); got != test.out { + t.Errorf("%s:\ngot: %s\nwant: %s", test.name, got, test.out) + } + } +} + +type rewriteTest struct { + name string + srcPkg string + dstPkg string + in string + out string +} + +var rewriteTests = []rewriteTest{ + { + name: "import.13", + srcPkg: "utf8", + dstPkg: "encoding/utf8", + in: `package main + +import ( + "io" + "os" + "utf8" // thanks ken +) +`, + out: `package main + +import ( + "encoding/utf8" // thanks ken + "io" + "os" +) +`, + }, + { + name: "import.14", + srcPkg: "asn1", + dstPkg: "encoding/asn1", + in: `package main + +import ( + "asn1" + "crypto" + "crypto/rsa" + _ "crypto/sha1" + "crypto/x509" + "crypto/x509/pkix" + "time" +) + +var x = 1 +`, + out: `package main + +import ( + "crypto" + "crypto/rsa" + _ "crypto/sha1" + "crypto/x509" + "crypto/x509/pkix" + "encoding/asn1" + "time" +) + +var x = 1 +`, + }, + { + name: "import.15", + srcPkg: "url", + dstPkg: "net/url", + in: `package main + +import ( + "bufio" + "net" + "path" + "url" +) + +var x = 1 // comment on x, not on url +`, + out: `package main + +import ( + "bufio" + "net" + "net/url" + "path" +) + +var x = 1 // comment on x, not on url +`, + }, + { + name: "import.16", + srcPkg: "http", + dstPkg: "net/http", + in: `package main + +import ( + "flag" + "http" + "log" + "text/template" +) + +var addr = flag.String("addr", ":1718", "http service address") // Q=17, R=18 +`, + out: `package main + +import ( + "flag" + "log" + "net/http" + "text/template" +) + +var addr = flag.String("addr", ":1718", "http service address") // Q=17, R=18 +`, + }, +} + +func TestRewriteImport(t *testing.T) { + for _, test := range rewriteTests { + file := parse(t, test.name, test.in) + RewriteImport(fset, file, test.srcPkg, test.dstPkg) + if got := print(t, test.name, file); got != test.out { + t.Errorf("%s:\ngot: %s\nwant: %s", test.name, got, test.out) + } + } +} + +var importsTests = []struct { + name string + in string + want [][]string +}{ + { + name: "no packages", + in: `package foo +`, + want: nil, + }, + { + name: "one group", + in: `package foo + +import ( + "fmt" + "testing" +) +`, + want: [][]string{{"fmt", "testing"}}, + }, + { + name: "four groups", + in: `package foo + +import "C" +import ( + "fmt" + "testing" + + "appengine" + + "myproject/mylib1" + "myproject/mylib2" +) +`, + want: [][]string{ + {"C"}, + {"fmt", "testing"}, + {"appengine"}, + {"myproject/mylib1", "myproject/mylib2"}, + }, + }, + { + name: "multiple factored groups", + in: `package foo + +import ( + "fmt" + "testing" + + "appengine" +) +import ( + "reflect" + + "bytes" +) +`, + want: [][]string{ + {"fmt", "testing"}, + {"appengine"}, + {"reflect"}, + {"bytes"}, + }, + }, +} + +func unquote(s string) string { + res, err := strconv.Unquote(s) + if err != nil { + return "could_not_unquote" + } + return res +} + +func TestImports(t *testing.T) { + fset := token.NewFileSet() + for _, test := range importsTests { + f, err := parser.ParseFile(fset, "test.go", test.in, 0) + if err != nil { + t.Errorf("%s: %v", test.name, err) + continue + } + var got [][]string + for _, group := range Imports(fset, f) { + var b []string + for _, spec := range group { + b = append(b, unquote(spec.Path.Value)) + } + got = append(got, b) + } + if !reflect.DeepEqual(got, test.want) { + t.Errorf("Imports(%s)=%v, want %v", test.name, got, test.want) + } + } +} + +var usesImportTests = []struct { + name string + path string + in string + want bool +}{ + { + name: "no packages", + path: "io", + in: `package foo +`, + want: false, + }, + { + name: "import.1", + path: "io", + in: `package foo + +import "io" + +var _ io.Writer +`, + want: true, + }, + { + name: "import.2", + path: "io", + in: `package foo + +import "io" +`, + want: false, + }, + { + name: "import.3", + path: "io", + in: `package foo + +import "io" + +var io = 42 +`, + want: false, + }, + { + name: "import.4", + path: "io", + in: `package foo + +import i "io" + +var _ i.Writer +`, + want: true, + }, + { + name: "import.5", + path: "io", + in: `package foo + +import i "io" +`, + want: false, + }, + { + name: "import.6", + path: "io", + in: `package foo + +import i "io" + +var i = 42 +var io = 42 +`, + want: false, + }, + { + name: "import.7", + path: "encoding/json", + in: `package foo + +import "encoding/json" + +var _ json.Encoder +`, + want: true, + }, + { + name: "import.8", + path: "encoding/json", + in: `package foo + +import "encoding/json" +`, + want: false, + }, + { + name: "import.9", + path: "encoding/json", + in: `package foo + +import "encoding/json" + +var json = 42 +`, + want: false, + }, + { + name: "import.10", + path: "encoding/json", + in: `package foo + +import j "encoding/json" + +var _ j.Encoder +`, + want: true, + }, + { + name: "import.11", + path: "encoding/json", + in: `package foo + +import j "encoding/json" +`, + want: false, + }, + { + name: "import.12", + path: "encoding/json", + in: `package foo + +import j "encoding/json" + +var j = 42 +var json = 42 +`, + want: false, + }, + { + name: "import.13", + path: "io", + in: `package foo + +import _ "io" +`, + want: true, + }, + { + name: "import.14", + path: "io", + in: `package foo + +import . "io" +`, + want: true, + }, +} + +func TestUsesImport(t *testing.T) { + fset := token.NewFileSet() + for _, test := range usesImportTests { + f, err := parser.ParseFile(fset, "test.go", test.in, 0) + if err != nil { + t.Errorf("%s: %v", test.name, err) + continue + } + got := UsesImport(f, test.path) + if got != test.want { + t.Errorf("UsesImport(%s)=%v, want %v", test.name, got, test.want) + } + } +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go new file mode 100644 index 0000000..cf72ea9 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go @@ -0,0 +1,477 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil + +import ( + "fmt" + "go/ast" + "reflect" + "sort" +) + +// An ApplyFunc is invoked by Apply for each node n, even if n is nil, +// before and/or after the node's children, using a Cursor describing +// the current node and providing operations on it. +// +// The return value of ApplyFunc controls the syntax tree traversal. +// See Apply for details. +type ApplyFunc func(*Cursor) bool + +// Apply traverses a syntax tree recursively, starting with root, +// and calling pre and post for each node as described below. +// Apply returns the syntax tree, possibly modified. +// +// If pre is not nil, it is called for each node before the node's +// children are traversed (pre-order). If pre returns false, no +// children are traversed, and post is not called for that node. +// +// If post is not nil, and a prior call of pre didn't return false, +// post is called for each node after its children are traversed +// (post-order). If post returns false, traversal is terminated and +// Apply returns immediately. +// +// Only fields that refer to AST nodes are considered children; +// i.e., token.Pos, Scopes, Objects, and fields of basic types +// (strings, etc.) are ignored. +// +// Children are traversed in the order in which they appear in the +// respective node's struct definition. A package's files are +// traversed in the filenames' alphabetical order. +// +func Apply(root ast.Node, pre, post ApplyFunc) (result ast.Node) { + parent := &struct{ ast.Node }{root} + defer func() { + if r := recover(); r != nil && r != abort { + panic(r) + } + result = parent.Node + }() + a := &application{pre: pre, post: post} + a.apply(parent, "Node", nil, root) + return +} + +var abort = new(int) // singleton, to signal termination of Apply + +// A Cursor describes a node encountered during Apply. +// Information about the node and its parent is available +// from the Node, Parent, Name, and Index methods. +// +// If p is a variable of type and value of the current parent node +// c.Parent(), and f is the field identifier with name c.Name(), +// the following invariants hold: +// +// p.f == c.Node() if c.Index() < 0 +// p.f[c.Index()] == c.Node() if c.Index() >= 0 +// +// The methods Replace, Delete, InsertBefore, and InsertAfter +// can be used to change the AST without disrupting Apply. +type Cursor struct { + parent ast.Node + name string + iter *iterator // valid if non-nil + node ast.Node +} + +// Node returns the current Node. +func (c *Cursor) Node() ast.Node { return c.node } + +// Parent returns the parent of the current Node. +func (c *Cursor) Parent() ast.Node { return c.parent } + +// Name returns the name of the parent Node field that contains the current Node. +// If the parent is a *ast.Package and the current Node is a *ast.File, Name returns +// the filename for the current Node. +func (c *Cursor) Name() string { return c.name } + +// Index reports the index >= 0 of the current Node in the slice of Nodes that +// contains it, or a value < 0 if the current Node is not part of a slice. +// The index of the current node changes if InsertBefore is called while +// processing the current node. +func (c *Cursor) Index() int { + if c.iter != nil { + return c.iter.index + } + return -1 +} + +// field returns the current node's parent field value. +func (c *Cursor) field() reflect.Value { + return reflect.Indirect(reflect.ValueOf(c.parent)).FieldByName(c.name) +} + +// Replace replaces the current Node with n. +// The replacement node is not walked by Apply. +func (c *Cursor) Replace(n ast.Node) { + if _, ok := c.node.(*ast.File); ok { + file, ok := n.(*ast.File) + if !ok { + panic("attempt to replace *ast.File with non-*ast.File") + } + c.parent.(*ast.Package).Files[c.name] = file + return + } + + v := c.field() + if i := c.Index(); i >= 0 { + v = v.Index(i) + } + v.Set(reflect.ValueOf(n)) +} + +// Delete deletes the current Node from its containing slice. +// If the current Node is not part of a slice, Delete panics. +// As a special case, if the current node is a package file, +// Delete removes it from the package's Files map. +func (c *Cursor) Delete() { + if _, ok := c.node.(*ast.File); ok { + delete(c.parent.(*ast.Package).Files, c.name) + return + } + + i := c.Index() + if i < 0 { + panic("Delete node not contained in slice") + } + v := c.field() + l := v.Len() + reflect.Copy(v.Slice(i, l), v.Slice(i+1, l)) + v.Index(l - 1).Set(reflect.Zero(v.Type().Elem())) + v.SetLen(l - 1) + c.iter.step-- +} + +// InsertAfter inserts n after the current Node in its containing slice. +// If the current Node is not part of a slice, InsertAfter panics. +// Apply does not walk n. +func (c *Cursor) InsertAfter(n ast.Node) { + i := c.Index() + if i < 0 { + panic("InsertAfter node not contained in slice") + } + v := c.field() + v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem()))) + l := v.Len() + reflect.Copy(v.Slice(i+2, l), v.Slice(i+1, l)) + v.Index(i + 1).Set(reflect.ValueOf(n)) + c.iter.step++ +} + +// InsertBefore inserts n before the current Node in its containing slice. +// If the current Node is not part of a slice, InsertBefore panics. +// Apply will not walk n. +func (c *Cursor) InsertBefore(n ast.Node) { + i := c.Index() + if i < 0 { + panic("InsertBefore node not contained in slice") + } + v := c.field() + v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem()))) + l := v.Len() + reflect.Copy(v.Slice(i+1, l), v.Slice(i, l)) + v.Index(i).Set(reflect.ValueOf(n)) + c.iter.index++ +} + +// application carries all the shared data so we can pass it around cheaply. +type application struct { + pre, post ApplyFunc + cursor Cursor + iter iterator +} + +func (a *application) apply(parent ast.Node, name string, iter *iterator, n ast.Node) { + // convert typed nil into untyped nil + if v := reflect.ValueOf(n); v.Kind() == reflect.Ptr && v.IsNil() { + n = nil + } + + // avoid heap-allocating a new cursor for each apply call; reuse a.cursor instead + saved := a.cursor + a.cursor.parent = parent + a.cursor.name = name + a.cursor.iter = iter + a.cursor.node = n + + if a.pre != nil && !a.pre(&a.cursor) { + a.cursor = saved + return + } + + // walk children + // (the order of the cases matches the order of the corresponding node types in go/ast) + switch n := n.(type) { + case nil: + // nothing to do + + // Comments and fields + case *ast.Comment: + // nothing to do + + case *ast.CommentGroup: + if n != nil { + a.applyList(n, "List") + } + + case *ast.Field: + a.apply(n, "Doc", nil, n.Doc) + a.applyList(n, "Names") + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Tag", nil, n.Tag) + a.apply(n, "Comment", nil, n.Comment) + + case *ast.FieldList: + a.applyList(n, "List") + + // Expressions + case *ast.BadExpr, *ast.Ident, *ast.BasicLit: + // nothing to do + + case *ast.Ellipsis: + a.apply(n, "Elt", nil, n.Elt) + + case *ast.FuncLit: + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Body", nil, n.Body) + + case *ast.CompositeLit: + a.apply(n, "Type", nil, n.Type) + a.applyList(n, "Elts") + + case *ast.ParenExpr: + a.apply(n, "X", nil, n.X) + + case *ast.SelectorExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Sel", nil, n.Sel) + + case *ast.IndexExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Index", nil, n.Index) + + case *ast.SliceExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Low", nil, n.Low) + a.apply(n, "High", nil, n.High) + a.apply(n, "Max", nil, n.Max) + + case *ast.TypeAssertExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Type", nil, n.Type) + + case *ast.CallExpr: + a.apply(n, "Fun", nil, n.Fun) + a.applyList(n, "Args") + + case *ast.StarExpr: + a.apply(n, "X", nil, n.X) + + case *ast.UnaryExpr: + a.apply(n, "X", nil, n.X) + + case *ast.BinaryExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Y", nil, n.Y) + + case *ast.KeyValueExpr: + a.apply(n, "Key", nil, n.Key) + a.apply(n, "Value", nil, n.Value) + + // Types + case *ast.ArrayType: + a.apply(n, "Len", nil, n.Len) + a.apply(n, "Elt", nil, n.Elt) + + case *ast.StructType: + a.apply(n, "Fields", nil, n.Fields) + + case *ast.FuncType: + a.apply(n, "Params", nil, n.Params) + a.apply(n, "Results", nil, n.Results) + + case *ast.InterfaceType: + a.apply(n, "Methods", nil, n.Methods) + + case *ast.MapType: + a.apply(n, "Key", nil, n.Key) + a.apply(n, "Value", nil, n.Value) + + case *ast.ChanType: + a.apply(n, "Value", nil, n.Value) + + // Statements + case *ast.BadStmt: + // nothing to do + + case *ast.DeclStmt: + a.apply(n, "Decl", nil, n.Decl) + + case *ast.EmptyStmt: + // nothing to do + + case *ast.LabeledStmt: + a.apply(n, "Label", nil, n.Label) + a.apply(n, "Stmt", nil, n.Stmt) + + case *ast.ExprStmt: + a.apply(n, "X", nil, n.X) + + case *ast.SendStmt: + a.apply(n, "Chan", nil, n.Chan) + a.apply(n, "Value", nil, n.Value) + + case *ast.IncDecStmt: + a.apply(n, "X", nil, n.X) + + case *ast.AssignStmt: + a.applyList(n, "Lhs") + a.applyList(n, "Rhs") + + case *ast.GoStmt: + a.apply(n, "Call", nil, n.Call) + + case *ast.DeferStmt: + a.apply(n, "Call", nil, n.Call) + + case *ast.ReturnStmt: + a.applyList(n, "Results") + + case *ast.BranchStmt: + a.apply(n, "Label", nil, n.Label) + + case *ast.BlockStmt: + a.applyList(n, "List") + + case *ast.IfStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Cond", nil, n.Cond) + a.apply(n, "Body", nil, n.Body) + a.apply(n, "Else", nil, n.Else) + + case *ast.CaseClause: + a.applyList(n, "List") + a.applyList(n, "Body") + + case *ast.SwitchStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Tag", nil, n.Tag) + a.apply(n, "Body", nil, n.Body) + + case *ast.TypeSwitchStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Assign", nil, n.Assign) + a.apply(n, "Body", nil, n.Body) + + case *ast.CommClause: + a.apply(n, "Comm", nil, n.Comm) + a.applyList(n, "Body") + + case *ast.SelectStmt: + a.apply(n, "Body", nil, n.Body) + + case *ast.ForStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Cond", nil, n.Cond) + a.apply(n, "Post", nil, n.Post) + a.apply(n, "Body", nil, n.Body) + + case *ast.RangeStmt: + a.apply(n, "Key", nil, n.Key) + a.apply(n, "Value", nil, n.Value) + a.apply(n, "X", nil, n.X) + a.apply(n, "Body", nil, n.Body) + + // Declarations + case *ast.ImportSpec: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Name", nil, n.Name) + a.apply(n, "Path", nil, n.Path) + a.apply(n, "Comment", nil, n.Comment) + + case *ast.ValueSpec: + a.apply(n, "Doc", nil, n.Doc) + a.applyList(n, "Names") + a.apply(n, "Type", nil, n.Type) + a.applyList(n, "Values") + a.apply(n, "Comment", nil, n.Comment) + + case *ast.TypeSpec: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Name", nil, n.Name) + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Comment", nil, n.Comment) + + case *ast.BadDecl: + // nothing to do + + case *ast.GenDecl: + a.apply(n, "Doc", nil, n.Doc) + a.applyList(n, "Specs") + + case *ast.FuncDecl: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Recv", nil, n.Recv) + a.apply(n, "Name", nil, n.Name) + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Body", nil, n.Body) + + // Files and packages + case *ast.File: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Name", nil, n.Name) + a.applyList(n, "Decls") + // Don't walk n.Comments; they have either been walked already if + // they are Doc comments, or they can be easily walked explicitly. + + case *ast.Package: + // collect and sort names for reproducible behavior + var names []string + for name := range n.Files { + names = append(names, name) + } + sort.Strings(names) + for _, name := range names { + a.apply(n, name, nil, n.Files[name]) + } + + default: + panic(fmt.Sprintf("Apply: unexpected node type %T", n)) + } + + if a.post != nil && !a.post(&a.cursor) { + panic(abort) + } + + a.cursor = saved +} + +// An iterator controls iteration over a slice of nodes. +type iterator struct { + index, step int +} + +func (a *application) applyList(parent ast.Node, name string) { + // avoid heap-allocating a new iterator for each applyList call; reuse a.iter instead + saved := a.iter + a.iter.index = 0 + for { + // must reload parent.name each time, since cursor modifications might change it + v := reflect.Indirect(reflect.ValueOf(parent)).FieldByName(name) + if a.iter.index >= v.Len() { + break + } + + // element x may be nil in a bad AST - be cautious + var x ast.Node + if e := v.Index(a.iter.index); e.IsValid() { + x = e.Interface().(ast.Node) + } + + a.iter.step = 1 + a.apply(parent, name, &a.iter, x) + a.iter.index += a.iter.step + } + a.iter = saved +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/rewrite_test.go b/vendor/golang.org/x/tools/go/ast/astutil/rewrite_test.go new file mode 100644 index 0000000..1c86970 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/rewrite_test.go @@ -0,0 +1,248 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil_test + +import ( + "bytes" + "go/ast" + "go/format" + "go/parser" + "go/token" + "testing" + + "golang.org/x/tools/go/ast/astutil" +) + +var rewriteTests = [...]struct { + name string + orig, want string + pre, post astutil.ApplyFunc +}{ + {name: "nop", orig: "package p\n", want: "package p\n"}, + + {name: "replace", + orig: `package p + +var x int +`, + want: `package p + +var t T +`, + post: func(c *astutil.Cursor) bool { + if _, ok := c.Node().(*ast.ValueSpec); ok { + c.Replace(valspec("t", "T")) + return false + } + return true + }, + }, + + {name: "set doc strings", + orig: `package p + +const z = 0 + +type T struct{} + +var x int +`, + want: `package p +// a foo is a foo +const z = 0 +// a foo is a foo +type T struct{} +// a foo is a foo +var x int +`, + post: func(c *astutil.Cursor) bool { + if _, ok := c.Parent().(*ast.GenDecl); ok && c.Name() == "Doc" && c.Node() == nil { + c.Replace(&ast.CommentGroup{List: []*ast.Comment{{Text: "// a foo is a foo"}}}) + } + return true + }, + }, + + {name: "insert names", + orig: `package p + +const a = 1 +`, + want: `package p + +const a, b, c = 1, 2, 3 +`, + pre: func(c *astutil.Cursor) bool { + if _, ok := c.Parent().(*ast.ValueSpec); ok { + switch c.Name() { + case "Names": + c.InsertAfter(ast.NewIdent("c")) + c.InsertAfter(ast.NewIdent("b")) + case "Values": + c.InsertAfter(&ast.BasicLit{Kind: token.INT, Value: "3"}) + c.InsertAfter(&ast.BasicLit{Kind: token.INT, Value: "2"}) + } + } + return true + }, + }, + + {name: "insert", + orig: `package p + +var ( + x int + y int +) +`, + want: `package p + +var before1 int +var before2 int + +var ( + x int + y int +) +var after2 int +var after1 int +`, + pre: func(c *astutil.Cursor) bool { + if _, ok := c.Node().(*ast.GenDecl); ok { + c.InsertBefore(vardecl("before1", "int")) + c.InsertAfter(vardecl("after1", "int")) + c.InsertAfter(vardecl("after2", "int")) + c.InsertBefore(vardecl("before2", "int")) + } + return true + }, + }, + + {name: "delete", + orig: `package p + +var x int +var y int +var z int +`, + want: `package p + +var y int +var z int +`, + pre: func(c *astutil.Cursor) bool { + n := c.Node() + if d, ok := n.(*ast.GenDecl); ok && d.Specs[0].(*ast.ValueSpec).Names[0].Name == "x" { + c.Delete() + } + return true + }, + }, + + {name: "insertafter-delete", + orig: `package p + +var x int +var y int +var z int +`, + want: `package p + +var x1 int + +var y int +var z int +`, + pre: func(c *astutil.Cursor) bool { + n := c.Node() + if d, ok := n.(*ast.GenDecl); ok && d.Specs[0].(*ast.ValueSpec).Names[0].Name == "x" { + c.InsertAfter(vardecl("x1", "int")) + c.Delete() + } + return true + }, + }, + + {name: "delete-insertafter", + orig: `package p + +var x int +var y int +var z int +`, + want: `package p + +var y int +var x1 int +var z int +`, + pre: func(c *astutil.Cursor) bool { + n := c.Node() + if d, ok := n.(*ast.GenDecl); ok && d.Specs[0].(*ast.ValueSpec).Names[0].Name == "x" { + c.Delete() + // The cursor is now effectively atop the 'var y int' node. + c.InsertAfter(vardecl("x1", "int")) + } + return true + }, + }, +} + +func valspec(name, typ string) *ast.ValueSpec { + return &ast.ValueSpec{Names: []*ast.Ident{ast.NewIdent(name)}, + Type: ast.NewIdent(typ), + } +} + +func vardecl(name, typ string) *ast.GenDecl { + return &ast.GenDecl{ + Tok: token.VAR, + Specs: []ast.Spec{valspec(name, typ)}, + } +} + +func TestRewrite(t *testing.T) { + t.Run("*", func(t *testing.T) { + for _, test := range rewriteTests { + test := test + t.Run(test.name, func(t *testing.T) { + t.Parallel() + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, test.name, test.orig, parser.ParseComments) + if err != nil { + t.Fatal(err) + } + n := astutil.Apply(f, test.pre, test.post) + var buf bytes.Buffer + if err := format.Node(&buf, fset, n); err != nil { + t.Fatal(err) + } + got := buf.String() + if got != test.want { + t.Errorf("got:\n\n%s\nwant:\n\n%s\n", got, test.want) + } + }) + } + }) +} + +var sink ast.Node + +func BenchmarkRewrite(b *testing.B) { + for _, test := range rewriteTests { + b.Run(test.name, func(b *testing.B) { + for i := 0; i < b.N; i++ { + b.StopTimer() + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, test.name, test.orig, parser.ParseComments) + if err != nil { + b.Fatal(err) + } + b.StartTimer() + sink = astutil.Apply(f, test.pre, test.post) + } + }) + } +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/util.go b/vendor/golang.org/x/tools/go/ast/astutil/util.go new file mode 100644 index 0000000..7630629 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/util.go @@ -0,0 +1,14 @@ +package astutil + +import "go/ast" + +// Unparen returns e with any enclosing parentheses stripped. +func Unparen(e ast.Expr) ast.Expr { + for { + p, ok := e.(*ast.ParenExpr) + if !ok { + return e + } + e = p.X + } +} diff --git a/vendor/golang.org/x/tools/go/buildutil/allpackages.go b/vendor/golang.org/x/tools/go/buildutil/allpackages.go new file mode 100644 index 0000000..c0cb03e --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/allpackages.go @@ -0,0 +1,198 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package buildutil provides utilities related to the go/build +// package in the standard library. +// +// All I/O is done via the build.Context file system interface, which must +// be concurrency-safe. +package buildutil // import "golang.org/x/tools/go/buildutil" + +import ( + "go/build" + "os" + "path/filepath" + "sort" + "strings" + "sync" +) + +// AllPackages returns the package path of each Go package in any source +// directory of the specified build context (e.g. $GOROOT or an element +// of $GOPATH). Errors are ignored. The results are sorted. +// All package paths are canonical, and thus may contain "/vendor/". +// +// The result may include import paths for directories that contain no +// *.go files, such as "archive" (in $GOROOT/src). +// +// All I/O is done via the build.Context file system interface, +// which must be concurrency-safe. +// +func AllPackages(ctxt *build.Context) []string { + var list []string + ForEachPackage(ctxt, func(pkg string, _ error) { + list = append(list, pkg) + }) + sort.Strings(list) + return list +} + +// ForEachPackage calls the found function with the package path of +// each Go package it finds in any source directory of the specified +// build context (e.g. $GOROOT or an element of $GOPATH). +// All package paths are canonical, and thus may contain "/vendor/". +// +// If the package directory exists but could not be read, the second +// argument to the found function provides the error. +// +// All I/O is done via the build.Context file system interface, +// which must be concurrency-safe. +// +func ForEachPackage(ctxt *build.Context, found func(importPath string, err error)) { + ch := make(chan item) + + var wg sync.WaitGroup + for _, root := range ctxt.SrcDirs() { + root := root + wg.Add(1) + go func() { + allPackages(ctxt, root, ch) + wg.Done() + }() + } + go func() { + wg.Wait() + close(ch) + }() + + // All calls to found occur in the caller's goroutine. + for i := range ch { + found(i.importPath, i.err) + } +} + +type item struct { + importPath string + err error // (optional) +} + +// We use a process-wide counting semaphore to limit +// the number of parallel calls to ReadDir. +var ioLimit = make(chan bool, 20) + +func allPackages(ctxt *build.Context, root string, ch chan<- item) { + root = filepath.Clean(root) + string(os.PathSeparator) + + var wg sync.WaitGroup + + var walkDir func(dir string) + walkDir = func(dir string) { + // Avoid .foo, _foo, and testdata directory trees. + base := filepath.Base(dir) + if base == "" || base[0] == '.' || base[0] == '_' || base == "testdata" { + return + } + + pkg := filepath.ToSlash(strings.TrimPrefix(dir, root)) + + // Prune search if we encounter any of these import paths. + switch pkg { + case "builtin": + return + } + + ioLimit <- true + files, err := ReadDir(ctxt, dir) + <-ioLimit + if pkg != "" || err != nil { + ch <- item{pkg, err} + } + for _, fi := range files { + fi := fi + if fi.IsDir() { + wg.Add(1) + go func() { + walkDir(filepath.Join(dir, fi.Name())) + wg.Done() + }() + } + } + } + + walkDir(root) + wg.Wait() +} + +// ExpandPatterns returns the set of packages matched by patterns, +// which may have the following forms: +// +// golang.org/x/tools/cmd/guru # a single package +// golang.org/x/tools/... # all packages beneath dir +// ... # the entire workspace. +// +// Order is significant: a pattern preceded by '-' removes matching +// packages from the set. For example, these patterns match all encoding +// packages except encoding/xml: +// +// encoding/... -encoding/xml +// +// A trailing slash in a pattern is ignored. (Path components of Go +// package names are separated by slash, not the platform's path separator.) +// +func ExpandPatterns(ctxt *build.Context, patterns []string) map[string]bool { + // TODO(adonovan): support other features of 'go list': + // - "std"/"cmd"/"all" meta-packages + // - "..." not at the end of a pattern + // - relative patterns using "./" or "../" prefix + + pkgs := make(map[string]bool) + doPkg := func(pkg string, neg bool) { + if neg { + delete(pkgs, pkg) + } else { + pkgs[pkg] = true + } + } + + // Scan entire workspace if wildcards are present. + // TODO(adonovan): opt: scan only the necessary subtrees of the workspace. + var all []string + for _, arg := range patterns { + if strings.HasSuffix(arg, "...") { + all = AllPackages(ctxt) + break + } + } + + for _, arg := range patterns { + if arg == "" { + continue + } + + neg := arg[0] == '-' + if neg { + arg = arg[1:] + } + + if arg == "..." { + // ... matches all packages + for _, pkg := range all { + doPkg(pkg, neg) + } + } else if dir := strings.TrimSuffix(arg, "/..."); dir != arg { + // dir/... matches all packages beneath dir + for _, pkg := range all { + if strings.HasPrefix(pkg, dir) && + (len(pkg) == len(dir) || pkg[len(dir)] == '/') { + doPkg(pkg, neg) + } + } + } else { + // single package + doPkg(strings.TrimSuffix(arg, "/"), neg) + } + } + + return pkgs +} diff --git a/vendor/golang.org/x/tools/go/buildutil/allpackages_test.go b/vendor/golang.org/x/tools/go/buildutil/allpackages_test.go new file mode 100644 index 0000000..0440ff2 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/allpackages_test.go @@ -0,0 +1,78 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Incomplete source tree on Android. + +// +build !android + +package buildutil_test + +import ( + "go/build" + "sort" + "strings" + "testing" + + "golang.org/x/tools/go/buildutil" +) + +func TestAllPackages(t *testing.T) { + all := buildutil.AllPackages(&build.Default) + + set := make(map[string]bool) + for _, pkg := range all { + set[pkg] = true + } + + const wantAtLeast = 250 + if len(all) < wantAtLeast { + t.Errorf("Found only %d packages, want at least %d", len(all), wantAtLeast) + } + + for _, want := range []string{"fmt", "crypto/sha256", "golang.org/x/tools/go/buildutil"} { + if !set[want] { + t.Errorf("Package %q not found; got %s", want, all) + } + } +} + +func TestExpandPatterns(t *testing.T) { + tree := make(map[string]map[string]string) + for _, pkg := range []string{ + "encoding", + "encoding/xml", + "encoding/hex", + "encoding/json", + "fmt", + } { + tree[pkg] = make(map[string]string) + } + ctxt := buildutil.FakeContext(tree) + + for _, test := range []struct { + patterns string + want string + }{ + {"", ""}, + {"fmt", "fmt"}, + {"nosuchpkg", "nosuchpkg"}, + {"nosuchdir/...", ""}, + {"...", "encoding encoding/hex encoding/json encoding/xml fmt"}, + {"encoding/... -encoding/xml", "encoding encoding/hex encoding/json"}, + {"... -encoding/...", "fmt"}, + {"encoding", "encoding"}, + {"encoding/", "encoding"}, + } { + var pkgs []string + for pkg := range buildutil.ExpandPatterns(ctxt, strings.Fields(test.patterns)) { + pkgs = append(pkgs, pkg) + } + sort.Strings(pkgs) + got := strings.Join(pkgs, " ") + if got != test.want { + t.Errorf("ExpandPatterns(%s) = %s, want %s", + test.patterns, got, test.want) + } + } +} diff --git a/vendor/golang.org/x/tools/go/buildutil/fakecontext.go b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go new file mode 100644 index 0000000..24cbcbe --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go @@ -0,0 +1,108 @@ +package buildutil + +import ( + "fmt" + "go/build" + "io" + "io/ioutil" + "os" + "path" + "path/filepath" + "sort" + "strings" + "time" +) + +// FakeContext returns a build.Context for the fake file tree specified +// by pkgs, which maps package import paths to a mapping from file base +// names to contents. +// +// The fake Context has a GOROOT of "/go" and no GOPATH, and overrides +// the necessary file access methods to read from memory instead of the +// real file system. +// +// Unlike a real file tree, the fake one has only two levels---packages +// and files---so ReadDir("/go/src/") returns all packages under +// /go/src/ including, for instance, "math" and "math/big". +// ReadDir("/go/src/math/big") would return all the files in the +// "math/big" package. +// +func FakeContext(pkgs map[string]map[string]string) *build.Context { + clean := func(filename string) string { + f := path.Clean(filepath.ToSlash(filename)) + // Removing "/go/src" while respecting segment + // boundaries has this unfortunate corner case: + if f == "/go/src" { + return "" + } + return strings.TrimPrefix(f, "/go/src/") + } + + ctxt := build.Default // copy + ctxt.GOROOT = "/go" + ctxt.GOPATH = "" + ctxt.IsDir = func(dir string) bool { + dir = clean(dir) + if dir == "" { + return true // needed by (*build.Context).SrcDirs + } + return pkgs[dir] != nil + } + ctxt.ReadDir = func(dir string) ([]os.FileInfo, error) { + dir = clean(dir) + var fis []os.FileInfo + if dir == "" { + // enumerate packages + for importPath := range pkgs { + fis = append(fis, fakeDirInfo(importPath)) + } + } else { + // enumerate files of package + for basename := range pkgs[dir] { + fis = append(fis, fakeFileInfo(basename)) + } + } + sort.Sort(byName(fis)) + return fis, nil + } + ctxt.OpenFile = func(filename string) (io.ReadCloser, error) { + filename = clean(filename) + dir, base := path.Split(filename) + content, ok := pkgs[path.Clean(dir)][base] + if !ok { + return nil, fmt.Errorf("file not found: %s", filename) + } + return ioutil.NopCloser(strings.NewReader(content)), nil + } + ctxt.IsAbsPath = func(path string) bool { + path = filepath.ToSlash(path) + // Don't rely on the default (filepath.Path) since on + // Windows, it reports virtual paths as non-absolute. + return strings.HasPrefix(path, "/") + } + return &ctxt +} + +type byName []os.FileInfo + +func (s byName) Len() int { return len(s) } +func (s byName) Swap(i, j int) { s[i], s[j] = s[j], s[i] } +func (s byName) Less(i, j int) bool { return s[i].Name() < s[j].Name() } + +type fakeFileInfo string + +func (fi fakeFileInfo) Name() string { return string(fi) } +func (fakeFileInfo) Sys() interface{} { return nil } +func (fakeFileInfo) ModTime() time.Time { return time.Time{} } +func (fakeFileInfo) IsDir() bool { return false } +func (fakeFileInfo) Size() int64 { return 0 } +func (fakeFileInfo) Mode() os.FileMode { return 0644 } + +type fakeDirInfo string + +func (fd fakeDirInfo) Name() string { return string(fd) } +func (fakeDirInfo) Sys() interface{} { return nil } +func (fakeDirInfo) ModTime() time.Time { return time.Time{} } +func (fakeDirInfo) IsDir() bool { return true } +func (fakeDirInfo) Size() int64 { return 0 } +func (fakeDirInfo) Mode() os.FileMode { return 0755 } diff --git a/vendor/golang.org/x/tools/go/buildutil/overlay.go b/vendor/golang.org/x/tools/go/buildutil/overlay.go new file mode 100644 index 0000000..3f71c4f --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/overlay.go @@ -0,0 +1,103 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package buildutil + +import ( + "bufio" + "bytes" + "fmt" + "go/build" + "io" + "io/ioutil" + "path/filepath" + "strconv" + "strings" +) + +// OverlayContext overlays a build.Context with additional files from +// a map. Files in the map take precedence over other files. +// +// In addition to plain string comparison, two file names are +// considered equal if their base names match and their directory +// components point at the same directory on the file system. That is, +// symbolic links are followed for directories, but not files. +// +// A common use case for OverlayContext is to allow editors to pass in +// a set of unsaved, modified files. +// +// Currently, only the Context.OpenFile function will respect the +// overlay. This may change in the future. +func OverlayContext(orig *build.Context, overlay map[string][]byte) *build.Context { + // TODO(dominikh): Implement IsDir, HasSubdir and ReadDir + + rc := func(data []byte) (io.ReadCloser, error) { + return ioutil.NopCloser(bytes.NewBuffer(data)), nil + } + + copy := *orig // make a copy + ctxt := © + ctxt.OpenFile = func(path string) (io.ReadCloser, error) { + // Fast path: names match exactly. + if content, ok := overlay[path]; ok { + return rc(content) + } + + // Slow path: check for same file under a different + // alias, perhaps due to a symbolic link. + for filename, content := range overlay { + if sameFile(path, filename) { + return rc(content) + } + } + + return OpenFile(orig, path) + } + return ctxt +} + +// ParseOverlayArchive parses an archive containing Go files and their +// contents. The result is intended to be used with OverlayContext. +// +// +// Archive format +// +// The archive consists of a series of files. Each file consists of a +// name, a decimal file size and the file contents, separated by +// newlinews. No newline follows after the file contents. +func ParseOverlayArchive(archive io.Reader) (map[string][]byte, error) { + overlay := make(map[string][]byte) + r := bufio.NewReader(archive) + for { + // Read file name. + filename, err := r.ReadString('\n') + if err != nil { + if err == io.EOF { + break // OK + } + return nil, fmt.Errorf("reading archive file name: %v", err) + } + filename = filepath.Clean(strings.TrimSpace(filename)) + + // Read file size. + sz, err := r.ReadString('\n') + if err != nil { + return nil, fmt.Errorf("reading size of archive file %s: %v", filename, err) + } + sz = strings.TrimSpace(sz) + size, err := strconv.ParseUint(sz, 10, 32) + if err != nil { + return nil, fmt.Errorf("parsing size of archive file %s: %v", filename, err) + } + + // Read file content. + content := make([]byte, size) + if _, err := io.ReadFull(r, content); err != nil { + return nil, fmt.Errorf("reading archive file %s: %v", filename, err) + } + overlay[filename] = content + } + + return overlay, nil +} diff --git a/vendor/golang.org/x/tools/go/buildutil/overlay_test.go b/vendor/golang.org/x/tools/go/buildutil/overlay_test.go new file mode 100644 index 0000000..92e2258 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/overlay_test.go @@ -0,0 +1,70 @@ +package buildutil_test + +import ( + "go/build" + "io/ioutil" + "reflect" + "strings" + "testing" + + "golang.org/x/tools/go/buildutil" +) + +func TestParseOverlayArchive(t *testing.T) { + var tt = []struct { + in string + out map[string][]byte + hasErr bool + }{ + { + "a.go\n5\n12345", + map[string][]byte{"a.go": []byte("12345")}, + false, + }, + { + "a.go\n5\n1234", + nil, + true, + }, + { + "a.go\n5\n12345b.go\n4\n1234", + map[string][]byte{"a.go": []byte("12345"), "b.go": []byte("1234")}, + false, + }, + } + + for _, test := range tt { + got, err := buildutil.ParseOverlayArchive(strings.NewReader(test.in)) + if err == nil && test.hasErr { + t.Errorf("expected error for %q", test.in) + } + if err != nil && !test.hasErr { + t.Errorf("unexpected error %v for %q", err, test.in) + } + if !reflect.DeepEqual(got, test.out) { + t.Errorf("got %#v, want %#v", got, test.out) + } + } +} + +func TestOverlay(t *testing.T) { + ctx := &build.Default + ov := map[string][]byte{ + "/somewhere/a.go": []byte("file contents"), + } + names := []string{"/somewhere/a.go", "/somewhere//a.go"} + ctx = buildutil.OverlayContext(ctx, ov) + for _, name := range names { + f, err := buildutil.OpenFile(ctx, name) + if err != nil { + t.Errorf("unexpected error %v", err) + } + b, err := ioutil.ReadAll(f) + if err != nil { + t.Errorf("unexpected error %v", err) + } + if got, expected := string(b), string(ov["/somewhere/a.go"]); got != expected { + t.Errorf("read %q, expected %q", got, expected) + } + } +} diff --git a/vendor/golang.org/x/tools/go/buildutil/tags.go b/vendor/golang.org/x/tools/go/buildutil/tags.go new file mode 100644 index 0000000..486606f --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/tags.go @@ -0,0 +1,75 @@ +package buildutil + +// This logic was copied from stringsFlag from $GOROOT/src/cmd/go/build.go. + +import "fmt" + +const TagsFlagDoc = "a list of `build tags` to consider satisfied during the build. " + + "For more information about build tags, see the description of " + + "build constraints in the documentation for the go/build package" + +// TagsFlag is an implementation of the flag.Value and flag.Getter interfaces that parses +// a flag value in the same manner as go build's -tags flag and +// populates a []string slice. +// +// See $GOROOT/src/go/build/doc.go for description of build tags. +// See $GOROOT/src/cmd/go/doc.go for description of 'go build -tags' flag. +// +// Example: +// flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc) +type TagsFlag []string + +func (v *TagsFlag) Set(s string) error { + var err error + *v, err = splitQuotedFields(s) + if *v == nil { + *v = []string{} + } + return err +} + +func (v *TagsFlag) Get() interface{} { return *v } + +func splitQuotedFields(s string) ([]string, error) { + // Split fields allowing '' or "" around elements. + // Quotes further inside the string do not count. + var f []string + for len(s) > 0 { + for len(s) > 0 && isSpaceByte(s[0]) { + s = s[1:] + } + if len(s) == 0 { + break + } + // Accepted quoted string. No unescaping inside. + if s[0] == '"' || s[0] == '\'' { + quote := s[0] + s = s[1:] + i := 0 + for i < len(s) && s[i] != quote { + i++ + } + if i >= len(s) { + return nil, fmt.Errorf("unterminated %c string", quote) + } + f = append(f, s[:i]) + s = s[i+1:] + continue + } + i := 0 + for i < len(s) && !isSpaceByte(s[i]) { + i++ + } + f = append(f, s[:i]) + s = s[i:] + } + return f, nil +} + +func (v *TagsFlag) String() string { + return "<tagsFlag>" +} + +func isSpaceByte(c byte) bool { + return c == ' ' || c == '\t' || c == '\n' || c == '\r' +} diff --git a/vendor/golang.org/x/tools/go/buildutil/tags_test.go b/vendor/golang.org/x/tools/go/buildutil/tags_test.go new file mode 100644 index 0000000..0fc2618 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/tags_test.go @@ -0,0 +1,28 @@ +package buildutil_test + +import ( + "flag" + "go/build" + "reflect" + "testing" + + "golang.org/x/tools/go/buildutil" +) + +func TestTags(t *testing.T) { + f := flag.NewFlagSet("TestTags", flag.PanicOnError) + var ctxt build.Context + f.Var((*buildutil.TagsFlag)(&ctxt.BuildTags), "tags", buildutil.TagsFlagDoc) + f.Parse([]string{"-tags", ` 'one'"two" 'three "four"'`, "rest"}) + + // BuildTags + want := []string{"one", "two", "three \"four\""} + if !reflect.DeepEqual(ctxt.BuildTags, want) { + t.Errorf("BuildTags = %q, want %q", ctxt.BuildTags, want) + } + + // Args() + if want := []string{"rest"}; !reflect.DeepEqual(f.Args(), want) { + t.Errorf("f.Args() = %q, want %q", f.Args(), want) + } +} diff --git a/vendor/golang.org/x/tools/go/buildutil/util.go b/vendor/golang.org/x/tools/go/buildutil/util.go new file mode 100644 index 0000000..fc923d7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/util.go @@ -0,0 +1,212 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package buildutil + +import ( + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "io" + "io/ioutil" + "os" + "path" + "path/filepath" + "strings" +) + +// ParseFile behaves like parser.ParseFile, +// but uses the build context's file system interface, if any. +// +// If file is not absolute (as defined by IsAbsPath), the (dir, file) +// components are joined using JoinPath; dir must be absolute. +// +// The displayPath function, if provided, is used to transform the +// filename that will be attached to the ASTs. +// +// TODO(adonovan): call this from go/loader.parseFiles when the tree thaws. +// +func ParseFile(fset *token.FileSet, ctxt *build.Context, displayPath func(string) string, dir string, file string, mode parser.Mode) (*ast.File, error) { + if !IsAbsPath(ctxt, file) { + file = JoinPath(ctxt, dir, file) + } + rd, err := OpenFile(ctxt, file) + if err != nil { + return nil, err + } + defer rd.Close() // ignore error + if displayPath != nil { + file = displayPath(file) + } + return parser.ParseFile(fset, file, rd, mode) +} + +// ContainingPackage returns the package containing filename. +// +// If filename is not absolute, it is interpreted relative to working directory dir. +// All I/O is via the build context's file system interface, if any. +// +// The '...Files []string' fields of the resulting build.Package are not +// populated (build.FindOnly mode). +// +func ContainingPackage(ctxt *build.Context, dir, filename string) (*build.Package, error) { + if !IsAbsPath(ctxt, filename) { + filename = JoinPath(ctxt, dir, filename) + } + + // We must not assume the file tree uses + // "/" always, + // `\` always, + // or os.PathSeparator (which varies by platform), + // but to make any progress, we are forced to assume that + // paths will not use `\` unless the PathSeparator + // is also `\`, thus we can rely on filepath.ToSlash for some sanity. + + dirSlash := path.Dir(filepath.ToSlash(filename)) + "/" + + // We assume that no source root (GOPATH[i] or GOROOT) contains any other. + for _, srcdir := range ctxt.SrcDirs() { + srcdirSlash := filepath.ToSlash(srcdir) + "/" + if importPath, ok := HasSubdir(ctxt, srcdirSlash, dirSlash); ok { + return ctxt.Import(importPath, dir, build.FindOnly) + } + } + + return nil, fmt.Errorf("can't find package containing %s", filename) +} + +// -- Effective methods of file system interface ------------------------- + +// (go/build.Context defines these as methods, but does not export them.) + +// hasSubdir calls ctxt.HasSubdir (if not nil) or else uses +// the local file system to answer the question. +func HasSubdir(ctxt *build.Context, root, dir string) (rel string, ok bool) { + if f := ctxt.HasSubdir; f != nil { + return f(root, dir) + } + + // Try using paths we received. + if rel, ok = hasSubdir(root, dir); ok { + return + } + + // Try expanding symlinks and comparing + // expanded against unexpanded and + // expanded against expanded. + rootSym, _ := filepath.EvalSymlinks(root) + dirSym, _ := filepath.EvalSymlinks(dir) + + if rel, ok = hasSubdir(rootSym, dir); ok { + return + } + if rel, ok = hasSubdir(root, dirSym); ok { + return + } + return hasSubdir(rootSym, dirSym) +} + +func hasSubdir(root, dir string) (rel string, ok bool) { + const sep = string(filepath.Separator) + root = filepath.Clean(root) + if !strings.HasSuffix(root, sep) { + root += sep + } + + dir = filepath.Clean(dir) + if !strings.HasPrefix(dir, root) { + return "", false + } + + return filepath.ToSlash(dir[len(root):]), true +} + +// FileExists returns true if the specified file exists, +// using the build context's file system interface. +func FileExists(ctxt *build.Context, path string) bool { + if ctxt.OpenFile != nil { + r, err := ctxt.OpenFile(path) + if err != nil { + return false + } + r.Close() // ignore error + return true + } + _, err := os.Stat(path) + return err == nil +} + +// OpenFile behaves like os.Open, +// but uses the build context's file system interface, if any. +func OpenFile(ctxt *build.Context, path string) (io.ReadCloser, error) { + if ctxt.OpenFile != nil { + return ctxt.OpenFile(path) + } + return os.Open(path) +} + +// IsAbsPath behaves like filepath.IsAbs, +// but uses the build context's file system interface, if any. +func IsAbsPath(ctxt *build.Context, path string) bool { + if ctxt.IsAbsPath != nil { + return ctxt.IsAbsPath(path) + } + return filepath.IsAbs(path) +} + +// JoinPath behaves like filepath.Join, +// but uses the build context's file system interface, if any. +func JoinPath(ctxt *build.Context, path ...string) string { + if ctxt.JoinPath != nil { + return ctxt.JoinPath(path...) + } + return filepath.Join(path...) +} + +// IsDir behaves like os.Stat plus IsDir, +// but uses the build context's file system interface, if any. +func IsDir(ctxt *build.Context, path string) bool { + if ctxt.IsDir != nil { + return ctxt.IsDir(path) + } + fi, err := os.Stat(path) + return err == nil && fi.IsDir() +} + +// ReadDir behaves like ioutil.ReadDir, +// but uses the build context's file system interface, if any. +func ReadDir(ctxt *build.Context, path string) ([]os.FileInfo, error) { + if ctxt.ReadDir != nil { + return ctxt.ReadDir(path) + } + return ioutil.ReadDir(path) +} + +// SplitPathList behaves like filepath.SplitList, +// but uses the build context's file system interface, if any. +func SplitPathList(ctxt *build.Context, s string) []string { + if ctxt.SplitPathList != nil { + return ctxt.SplitPathList(s) + } + return filepath.SplitList(s) +} + +// sameFile returns true if x and y have the same basename and denote +// the same file. +// +func sameFile(x, y string) bool { + if path.Clean(x) == path.Clean(y) { + return true + } + if filepath.Base(x) == filepath.Base(y) { // (optimisation) + if xi, err := os.Stat(x); err == nil { + if yi, err := os.Stat(y); err == nil { + return os.SameFile(xi, yi) + } + } + } + return false +} diff --git a/vendor/golang.org/x/tools/go/buildutil/util_test.go b/vendor/golang.org/x/tools/go/buildutil/util_test.go new file mode 100644 index 0000000..72db317 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/util_test.go @@ -0,0 +1,72 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package buildutil_test + +import ( + "go/build" + "io/ioutil" + "os" + "path/filepath" + "runtime" + "testing" + + "golang.org/x/tools/go/buildutil" +) + +func TestContainingPackage(t *testing.T) { + // unvirtualized: + goroot := runtime.GOROOT() + gopath := filepath.SplitList(os.Getenv("GOPATH"))[0] + + type Test struct { + gopath, filename, wantPkg string + } + + tests := []Test{ + {gopath, goroot + "/src/fmt/print.go", "fmt"}, + {gopath, goroot + "/src/encoding/json/foo.go", "encoding/json"}, + {gopath, goroot + "/src/encoding/missing/foo.go", "(not found)"}, + {gopath, gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go", + "golang.org/x/tools/go/buildutil"}, + } + + if runtime.GOOS != "windows" && runtime.GOOS != "plan9" { + // Make a symlink to gopath for test + tmp, err := ioutil.TempDir(os.TempDir(), "go") + if err != nil { + t.Errorf("Unable to create a temporary directory in %s", os.TempDir()) + } + + defer os.RemoveAll(tmp) + + // symlink between $GOPATH/src and /tmp/go/src + // in order to test all possible symlink cases + if err := os.Symlink(gopath+"/src", tmp+"/src"); err != nil { + t.Fatal(err) + } + tests = append(tests, []Test{ + {gopath, tmp + "/src/golang.org/x/tools/go/buildutil/util_test.go", "golang.org/x/tools/go/buildutil"}, + {tmp, gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go", "golang.org/x/tools/go/buildutil"}, + {tmp, tmp + "/src/golang.org/x/tools/go/buildutil/util_test.go", "golang.org/x/tools/go/buildutil"}, + }...) + } + + for _, test := range tests { + var got string + var buildContext = build.Default + buildContext.GOPATH = test.gopath + bp, err := buildutil.ContainingPackage(&buildContext, ".", test.filename) + if err != nil { + got = "(not found)" + } else { + got = bp.ImportPath + } + if got != test.wantPkg { + t.Errorf("ContainingPackage(%q) = %s, want %s", test.filename, got, test.wantPkg) + } + } + + // TODO(adonovan): test on virtualized GOPATH too. +} diff --git a/vendor/golang.org/x/tools/go/buildutil/util_windows_test.go b/vendor/golang.org/x/tools/go/buildutil/util_windows_test.go new file mode 100644 index 0000000..86fe9c7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/util_windows_test.go @@ -0,0 +1,48 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package buildutil_test + +import ( + "fmt" + "go/build" + "path/filepath" + "runtime" + "strings" + "testing" + + "golang.org/x/tools/go/buildutil" +) + +func testContainingPackageCaseFold(file, want string) error { + bp, err := buildutil.ContainingPackage(&build.Default, ".", file) + if err != nil { + return err + } + if got := bp.ImportPath; got != want { + return fmt.Errorf("ContainingPackage(%q) = %s, want %s", file, got, want) + } + return nil +} + +func TestContainingPackageCaseFold(t *testing.T) { + path := filepath.Join(runtime.GOROOT(), `src\fmt\print.go`) + err := testContainingPackageCaseFold(path, "fmt") + if err != nil { + t.Error(err) + } + vol := filepath.VolumeName(path) + if len(vol) != 2 || vol[1] != ':' { + t.Fatalf("GOROOT path has unexpected volume name: %v", vol) + } + rest := path[len(vol):] + err = testContainingPackageCaseFold(strings.ToUpper(vol)+rest, "fmt") + if err != nil { + t.Error(err) + } + err = testContainingPackageCaseFold(strings.ToLower(vol)+rest, "fmt") + if err != nil { + t.Error(err) + } +} diff --git a/vendor/golang.org/x/tools/go/callgraph/callgraph.go b/vendor/golang.org/x/tools/go/callgraph/callgraph.go new file mode 100644 index 0000000..707a319 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/callgraph.go @@ -0,0 +1,129 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* + +Package callgraph defines the call graph and various algorithms +and utilities to operate on it. + +A call graph is a labelled directed graph whose nodes represent +functions and whose edge labels represent syntactic function call +sites. The presence of a labelled edge (caller, site, callee) +indicates that caller may call callee at the specified call site. + +A call graph is a multigraph: it may contain multiple edges (caller, +*, callee) connecting the same pair of nodes, so long as the edges +differ by label; this occurs when one function calls another function +from multiple call sites. Also, it may contain multiple edges +(caller, site, *) that differ only by callee; this indicates a +polymorphic call. + +A SOUND call graph is one that overapproximates the dynamic calling +behaviors of the program in all possible executions. One call graph +is more PRECISE than another if it is a smaller overapproximation of +the dynamic behavior. + +All call graphs have a synthetic root node which is responsible for +calling main() and init(). + +Calls to built-in functions (e.g. panic, println) are not represented +in the call graph; they are treated like built-in operators of the +language. + +*/ +package callgraph // import "golang.org/x/tools/go/callgraph" + +// TODO(adonovan): add a function to eliminate wrappers from the +// callgraph, preserving topology. +// More generally, we could eliminate "uninteresting" nodes such as +// nodes from packages we don't care about. + +import ( + "fmt" + "go/token" + + "golang.org/x/tools/go/ssa" +) + +// A Graph represents a call graph. +// +// A graph may contain nodes that are not reachable from the root. +// If the call graph is sound, such nodes indicate unreachable +// functions. +// +type Graph struct { + Root *Node // the distinguished root node + Nodes map[*ssa.Function]*Node // all nodes by function +} + +// New returns a new Graph with the specified root node. +func New(root *ssa.Function) *Graph { + g := &Graph{Nodes: make(map[*ssa.Function]*Node)} + g.Root = g.CreateNode(root) + return g +} + +// CreateNode returns the Node for fn, creating it if not present. +func (g *Graph) CreateNode(fn *ssa.Function) *Node { + n, ok := g.Nodes[fn] + if !ok { + n = &Node{Func: fn, ID: len(g.Nodes)} + g.Nodes[fn] = n + } + return n +} + +// A Node represents a node in a call graph. +type Node struct { + Func *ssa.Function // the function this node represents + ID int // 0-based sequence number + In []*Edge // unordered set of incoming call edges (n.In[*].Callee == n) + Out []*Edge // unordered set of outgoing call edges (n.Out[*].Caller == n) +} + +func (n *Node) String() string { + return fmt.Sprintf("n%d:%s", n.ID, n.Func) +} + +// A Edge represents an edge in the call graph. +// +// Site is nil for edges originating in synthetic or intrinsic +// functions, e.g. reflect.Call or the root of the call graph. +type Edge struct { + Caller *Node + Site ssa.CallInstruction + Callee *Node +} + +func (e Edge) String() string { + return fmt.Sprintf("%s --> %s", e.Caller, e.Callee) +} + +func (e Edge) Description() string { + var prefix string + switch e.Site.(type) { + case nil: + return "synthetic call" + case *ssa.Go: + prefix = "concurrent " + case *ssa.Defer: + prefix = "deferred " + } + return prefix + e.Site.Common().Description() +} + +func (e Edge) Pos() token.Pos { + if e.Site == nil { + return token.NoPos + } + return e.Site.Pos() +} + +// AddEdge adds the edge (caller, site, callee) to the call graph. +// Elimination of duplicate edges is the caller's responsibility. +func AddEdge(caller *Node, site ssa.CallInstruction, callee *Node) { + e := &Edge{caller, site, callee} + callee.In = append(callee.In, e) + caller.Out = append(caller.Out, e) +} diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/cha.go b/vendor/golang.org/x/tools/go/callgraph/cha/cha.go new file mode 100644 index 0000000..215ff17 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/cha.go @@ -0,0 +1,139 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package cha computes the call graph of a Go program using the Class +// Hierarchy Analysis (CHA) algorithm. +// +// CHA was first described in "Optimization of Object-Oriented Programs +// Using Static Class Hierarchy Analysis", Jeffrey Dean, David Grove, +// and Craig Chambers, ECOOP'95. +// +// CHA is related to RTA (see go/callgraph/rta); the difference is that +// CHA conservatively computes the entire "implements" relation between +// interfaces and concrete types ahead of time, whereas RTA uses dynamic +// programming to construct it on the fly as it encounters new functions +// reachable from main. CHA may thus include spurious call edges for +// types that haven't been instantiated yet, or types that are never +// instantiated. +// +// Since CHA conservatively assumes that all functions are address-taken +// and all concrete types are put into interfaces, it is sound to run on +// partial programs, such as libraries without a main or test function. +// +package cha // import "golang.org/x/tools/go/callgraph/cha" + +import ( + "go/types" + + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" + "golang.org/x/tools/go/types/typeutil" +) + +// CallGraph computes the call graph of the specified program using the +// Class Hierarchy Analysis algorithm. +// +func CallGraph(prog *ssa.Program) *callgraph.Graph { + cg := callgraph.New(nil) // TODO(adonovan) eliminate concept of rooted callgraph + + allFuncs := ssautil.AllFunctions(prog) + + // funcsBySig contains all functions, keyed by signature. It is + // the effective set of address-taken functions used to resolve + // a dynamic call of a particular signature. + var funcsBySig typeutil.Map // value is []*ssa.Function + + // methodsByName contains all methods, + // grouped by name for efficient lookup. + // (methodsById would be better but not every SSA method has a go/types ID.) + methodsByName := make(map[string][]*ssa.Function) + + // An imethod represents an interface method I.m. + // (There's no go/types object for it; + // a *types.Func may be shared by many interfaces due to interface embedding.) + type imethod struct { + I *types.Interface + id string + } + // methodsMemo records, for every abstract method call I.m on + // interface type I, the set of concrete methods C.m of all + // types C that satisfy interface I. + // + // Abstract methods may be shared by several interfaces, + // hence we must pass I explicitly, not guess from m. + // + // methodsMemo is just a cache, so it needn't be a typeutil.Map. + methodsMemo := make(map[imethod][]*ssa.Function) + lookupMethods := func(I *types.Interface, m *types.Func) []*ssa.Function { + id := m.Id() + methods, ok := methodsMemo[imethod{I, id}] + if !ok { + for _, f := range methodsByName[m.Name()] { + C := f.Signature.Recv().Type() // named or *named + if types.Implements(C, I) { + methods = append(methods, f) + } + } + methodsMemo[imethod{I, id}] = methods + } + return methods + } + + for f := range allFuncs { + if f.Signature.Recv() == nil { + // Package initializers can never be address-taken. + if f.Name() == "init" && f.Synthetic == "package initializer" { + continue + } + funcs, _ := funcsBySig.At(f.Signature).([]*ssa.Function) + funcs = append(funcs, f) + funcsBySig.Set(f.Signature, funcs) + } else { + methodsByName[f.Name()] = append(methodsByName[f.Name()], f) + } + } + + addEdge := func(fnode *callgraph.Node, site ssa.CallInstruction, g *ssa.Function) { + gnode := cg.CreateNode(g) + callgraph.AddEdge(fnode, site, gnode) + } + + addEdges := func(fnode *callgraph.Node, site ssa.CallInstruction, callees []*ssa.Function) { + // Because every call to a highly polymorphic and + // frequently used abstract method such as + // (io.Writer).Write is assumed to call every concrete + // Write method in the program, the call graph can + // contain a lot of duplication. + // + // TODO(adonovan): opt: consider factoring the callgraph + // API so that the Callers component of each edge is a + // slice of nodes, not a singleton. + for _, g := range callees { + addEdge(fnode, site, g) + } + } + + for f := range allFuncs { + fnode := cg.CreateNode(f) + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + if site, ok := instr.(ssa.CallInstruction); ok { + call := site.Common() + if call.IsInvoke() { + tiface := call.Value.Type().Underlying().(*types.Interface) + addEdges(fnode, site, lookupMethods(tiface, call.Method)) + } else if g := call.StaticCallee(); g != nil { + addEdge(fnode, site, g) + } else if _, ok := call.Value.(*ssa.Builtin); !ok { + callees, _ := funcsBySig.At(call.Signature()).([]*ssa.Function) + addEdges(fnode, site, callees) + } + } + } + } + } + + return cg +} diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/cha_test.go b/vendor/golang.org/x/tools/go/callgraph/cha/cha_test.go new file mode 100644 index 0000000..cb2d585 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/cha_test.go @@ -0,0 +1,111 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// No testdata on Android. + +// +build !android + +package cha_test + +import ( + "bytes" + "fmt" + "go/ast" + "go/parser" + "go/token" + "go/types" + "io/ioutil" + "sort" + "strings" + "testing" + + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/callgraph/cha" + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa/ssautil" +) + +var inputs = []string{ + "testdata/func.go", + "testdata/iface.go", + "testdata/recv.go", + "testdata/issue23925.go", +} + +func expectation(f *ast.File) (string, token.Pos) { + for _, c := range f.Comments { + text := strings.TrimSpace(c.Text()) + if t := strings.TrimPrefix(text, "WANT:\n"); t != text { + return t, c.Pos() + } + } + return "", token.NoPos +} + +// TestCHA runs CHA on each file in inputs, prints the dynamic edges of +// the call graph, and compares it with the golden results embedded in +// the WANT comment at the end of the file. +// +func TestCHA(t *testing.T) { + for _, filename := range inputs { + content, err := ioutil.ReadFile(filename) + if err != nil { + t.Errorf("couldn't read file '%s': %s", filename, err) + continue + } + + conf := loader.Config{ + ParserMode: parser.ParseComments, + } + f, err := conf.ParseFile(filename, content) + if err != nil { + t.Error(err) + continue + } + + want, pos := expectation(f) + if pos == token.NoPos { + t.Errorf("No WANT: comment in %s", filename) + continue + } + + conf.CreateFromFiles("main", f) + iprog, err := conf.Load() + if err != nil { + t.Error(err) + continue + } + + prog := ssautil.CreateProgram(iprog, 0) + mainPkg := prog.Package(iprog.Created[0].Pkg) + prog.Build() + + cg := cha.CallGraph(prog) + + if got := printGraph(cg, mainPkg.Pkg); got != want { + t.Errorf("%s: got:\n%s\nwant:\n%s", + prog.Fset.Position(pos), got, want) + } + } +} + +func printGraph(cg *callgraph.Graph, from *types.Package) string { + var edges []string + callgraph.GraphVisitEdges(cg, func(e *callgraph.Edge) error { + if strings.Contains(e.Description(), "dynamic") { + edges = append(edges, fmt.Sprintf("%s --> %s", + e.Caller.Func.RelString(from), + e.Callee.Func.RelString(from))) + } + return nil + }) + sort.Strings(edges) + + var buf bytes.Buffer + buf.WriteString("Dynamic calls\n") + for _, edge := range edges { + fmt.Fprintf(&buf, " %s\n", edge) + } + return strings.TrimSpace(buf.String()) +} diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/testdata/func.go b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/func.go new file mode 100644 index 0000000..ad483f1 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/func.go @@ -0,0 +1,23 @@ +//+build ignore + +package main + +// Test of dynamic function calls; no interfaces. + +func A(int) {} + +var ( + B = func(int) {} + C = func(int) {} +) + +func f() { + pfn := B + pfn(0) // calls A, B, C, even though A is not even address-taken +} + +// WANT: +// Dynamic calls +// f --> A +// f --> init$1 +// f --> init$2 diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/testdata/iface.go b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/iface.go new file mode 100644 index 0000000..1622ec1 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/iface.go @@ -0,0 +1,65 @@ +//+build ignore + +package main + +// Test of interface calls. None of the concrete types are ever +// instantiated or converted to interfaces. + +type I interface { + f() +} + +type J interface { + f() + g() +} + +type C int // implements I + +func (*C) f() + +type D int // implements I and J + +func (*D) f() +func (*D) g() + +func one(i I, j J) { + i.f() // calls *C and *D +} + +func two(i I, j J) { + j.f() // calls *D (but not *C, even though it defines method f) +} + +func three(i I, j J) { + j.g() // calls *D +} + +func four(i I, j J) { + Jf := J.f + if unknown { + Jf = nil // suppress SSA constant propagation + } + Jf(nil) // calls *D +} + +func five(i I, j J) { + jf := j.f + if unknown { + jf = nil // suppress SSA constant propagation + } + jf() // calls *D +} + +var unknown bool + +// WANT: +// Dynamic calls +// (J).f$bound --> (*D).f +// (J).f$thunk --> (*D).f +// five --> (J).f$bound +// four --> (J).f$thunk +// one --> (*C).f +// one --> (*D).f +// three --> (*D).g +// two --> (*D).f diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/testdata/issue23925.go b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/issue23925.go new file mode 100644 index 0000000..59eaf18 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/issue23925.go @@ -0,0 +1,38 @@ +package main + +// Regression test for https://github.com/golang/go/issues/23925 + +type stringFlagImpl string + +func (*stringFlagImpl) Set(s string) error { return nil } + +type boolFlagImpl bool + +func (*boolFlagImpl) Set(s string) error { return nil } +func (*boolFlagImpl) extra() {} + +// A copy of flag.boolFlag interface, without a dependency. +// Must appear first, so that it becomes the owner of the Set methods. +type boolFlag interface { + flagValue + extra() +} + +// A copy of flag.Value, without adding a dependency. +type flagValue interface { + Set(string) error +} + +func main() { + var x flagValue = new(stringFlagImpl) + x.Set("") + + var y boolFlag = new(boolFlagImpl) + y.Set("") +} + +// WANT: +// Dynamic calls +// main --> (*boolFlagImpl).Set +// main --> (*boolFlagImpl).Set +// main --> (*stringFlagImpl).Set diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/testdata/recv.go b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/recv.go new file mode 100644 index 0000000..5ba48e9 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/testdata/recv.go @@ -0,0 +1,37 @@ +//+build ignore + +package main + +type I interface { + f() +} + +type J interface { + g() +} + +type C int // C and *C implement I; *C implements J + +func (C) f() +func (*C) g() + +type D int // *D implements I and J + +func (*D) f() +func (*D) g() + +func f(i I) { + i.f() // calls C, *C, *D +} + +func g(j J) { + j.g() // calls *C, *D +} + +// WANT: +// Dynamic calls +// f --> (*C).f +// f --> (*D).f +// f --> (C).f +// g --> (*C).g +// g --> (*D).g diff --git a/vendor/golang.org/x/tools/go/callgraph/util.go b/vendor/golang.org/x/tools/go/callgraph/util.go new file mode 100644 index 0000000..a8f8903 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/util.go @@ -0,0 +1,181 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package callgraph + +import "golang.org/x/tools/go/ssa" + +// This file provides various utilities over call graphs, such as +// visitation and path search. + +// CalleesOf returns a new set containing all direct callees of the +// caller node. +// +func CalleesOf(caller *Node) map[*Node]bool { + callees := make(map[*Node]bool) + for _, e := range caller.Out { + callees[e.Callee] = true + } + return callees +} + +// GraphVisitEdges visits all the edges in graph g in depth-first order. +// The edge function is called for each edge in postorder. If it +// returns non-nil, visitation stops and GraphVisitEdges returns that +// value. +// +func GraphVisitEdges(g *Graph, edge func(*Edge) error) error { + seen := make(map[*Node]bool) + var visit func(n *Node) error + visit = func(n *Node) error { + if !seen[n] { + seen[n] = true + for _, e := range n.Out { + if err := visit(e.Callee); err != nil { + return err + } + if err := edge(e); err != nil { + return err + } + } + } + return nil + } + for _, n := range g.Nodes { + if err := visit(n); err != nil { + return err + } + } + return nil +} + +// PathSearch finds an arbitrary path starting at node start and +// ending at some node for which isEnd() returns true. On success, +// PathSearch returns the path as an ordered list of edges; on +// failure, it returns nil. +// +func PathSearch(start *Node, isEnd func(*Node) bool) []*Edge { + stack := make([]*Edge, 0, 32) + seen := make(map[*Node]bool) + var search func(n *Node) []*Edge + search = func(n *Node) []*Edge { + if !seen[n] { + seen[n] = true + if isEnd(n) { + return stack + } + for _, e := range n.Out { + stack = append(stack, e) // push + if found := search(e.Callee); found != nil { + return found + } + stack = stack[:len(stack)-1] // pop + } + } + return nil + } + return search(start) +} + +// DeleteSyntheticNodes removes from call graph g all nodes for +// synthetic functions (except g.Root and package initializers), +// preserving the topology. In effect, calls to synthetic wrappers +// are "inlined". +// +func (g *Graph) DeleteSyntheticNodes() { + // Measurements on the standard library and go.tools show that + // resulting graph has ~15% fewer nodes and 4-8% fewer edges + // than the input. + // + // Inlining a wrapper of in-degree m, out-degree n adds m*n + // and removes m+n edges. Since most wrappers are monomorphic + // (n=1) this results in a slight reduction. Polymorphic + // wrappers (n>1), e.g. from embedding an interface value + // inside a struct to satisfy some interface, cause an + // increase in the graph, but they seem to be uncommon. + + // Hash all existing edges to avoid creating duplicates. + edges := make(map[Edge]bool) + for _, cgn := range g.Nodes { + for _, e := range cgn.Out { + edges[*e] = true + } + } + for fn, cgn := range g.Nodes { + if cgn == g.Root || fn.Synthetic == "" || isInit(cgn.Func) { + continue // keep + } + for _, eIn := range cgn.In { + for _, eOut := range cgn.Out { + newEdge := Edge{eIn.Caller, eIn.Site, eOut.Callee} + if edges[newEdge] { + continue // don't add duplicate + } + AddEdge(eIn.Caller, eIn.Site, eOut.Callee) + edges[newEdge] = true + } + } + g.DeleteNode(cgn) + } +} + +func isInit(fn *ssa.Function) bool { + return fn.Pkg != nil && fn.Pkg.Func("init") == fn +} + +// DeleteNode removes node n and its edges from the graph g. +// (NB: not efficient for batch deletion.) +func (g *Graph) DeleteNode(n *Node) { + n.deleteIns() + n.deleteOuts() + delete(g.Nodes, n.Func) +} + +// deleteIns deletes all incoming edges to n. +func (n *Node) deleteIns() { + for _, e := range n.In { + removeOutEdge(e) + } + n.In = nil +} + +// deleteOuts deletes all outgoing edges from n. +func (n *Node) deleteOuts() { + for _, e := range n.Out { + removeInEdge(e) + } + n.Out = nil +} + +// removeOutEdge removes edge.Caller's outgoing edge 'edge'. +func removeOutEdge(edge *Edge) { + caller := edge.Caller + n := len(caller.Out) + for i, e := range caller.Out { + if e == edge { + // Replace it with the final element and shrink the slice. + caller.Out[i] = caller.Out[n-1] + caller.Out[n-1] = nil // aid GC + caller.Out = caller.Out[:n-1] + return + } + } + panic("edge not found: " + edge.String()) +} + +// removeInEdge removes edge.Callee's incoming edge 'edge'. +func removeInEdge(edge *Edge) { + caller := edge.Callee + n := len(caller.In) + for i, e := range caller.In { + if e == edge { + // Replace it with the final element and shrink the slice. + caller.In[i] = caller.In[n-1] + caller.In[n-1] = nil // aid GC + caller.In = caller.In[:n-1] + return + } + } + panic("edge not found: " + edge.String()) +} diff --git a/vendor/golang.org/x/tools/go/loader/cgo.go b/vendor/golang.org/x/tools/go/loader/cgo.go new file mode 100644 index 0000000..72c6f50 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/cgo.go @@ -0,0 +1,207 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader + +// This file handles cgo preprocessing of files containing `import "C"`. +// +// DESIGN +// +// The approach taken is to run the cgo processor on the package's +// CgoFiles and parse the output, faking the filenames of the +// resulting ASTs so that the synthetic file containing the C types is +// called "C" (e.g. "~/go/src/net/C") and the preprocessed files +// have their original names (e.g. "~/go/src/net/cgo_unix.go"), +// not the names of the actual temporary files. +// +// The advantage of this approach is its fidelity to 'go build'. The +// downside is that the token.Position.Offset for each AST node is +// incorrect, being an offset within the temporary file. Line numbers +// should still be correct because of the //line comments. +// +// The logic of this file is mostly plundered from the 'go build' +// tool, which also invokes the cgo preprocessor. +// +// +// REJECTED ALTERNATIVE +// +// An alternative approach that we explored is to extend go/types' +// Importer mechanism to provide the identity of the importing package +// so that each time `import "C"` appears it resolves to a different +// synthetic package containing just the objects needed in that case. +// The loader would invoke cgo but parse only the cgo_types.go file +// defining the package-level objects, discarding the other files +// resulting from preprocessing. +// +// The benefit of this approach would have been that source-level +// syntax information would correspond exactly to the original cgo +// file, with no preprocessing involved, making source tools like +// godoc, guru, and eg happy. However, the approach was rejected +// due to the additional complexity it would impose on go/types. (It +// made for a beautiful demo, though.) +// +// cgo files, despite their *.go extension, are not legal Go source +// files per the specification since they may refer to unexported +// members of package "C" such as C.int. Also, a function such as +// C.getpwent has in effect two types, one matching its C type and one +// which additionally returns (errno C.int). The cgo preprocessor +// uses name mangling to distinguish these two functions in the +// processed code, but go/types would need to duplicate this logic in +// its handling of function calls, analogous to the treatment of map +// lookups in which y=m[k] and y,ok=m[k] are both legal. + +import ( + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "io/ioutil" + "log" + "os" + "os/exec" + "path/filepath" + "regexp" + "strings" +) + +// processCgoFiles invokes the cgo preprocessor on bp.CgoFiles, parses +// the output and returns the resulting ASTs. +// +func processCgoFiles(bp *build.Package, fset *token.FileSet, DisplayPath func(path string) string, mode parser.Mode) ([]*ast.File, error) { + tmpdir, err := ioutil.TempDir("", strings.Replace(bp.ImportPath, "/", "_", -1)+"_C") + if err != nil { + return nil, err + } + defer os.RemoveAll(tmpdir) + + pkgdir := bp.Dir + if DisplayPath != nil { + pkgdir = DisplayPath(pkgdir) + } + + cgoFiles, cgoDisplayFiles, err := runCgo(bp, pkgdir, tmpdir) + if err != nil { + return nil, err + } + var files []*ast.File + for i := range cgoFiles { + rd, err := os.Open(cgoFiles[i]) + if err != nil { + return nil, err + } + display := filepath.Join(bp.Dir, cgoDisplayFiles[i]) + f, err := parser.ParseFile(fset, display, rd, mode) + rd.Close() + if err != nil { + return nil, err + } + files = append(files, f) + } + return files, nil +} + +var cgoRe = regexp.MustCompile(`[/\\:]`) + +// runCgo invokes the cgo preprocessor on bp.CgoFiles and returns two +// lists of files: the resulting processed files (in temporary +// directory tmpdir) and the corresponding names of the unprocessed files. +// +// runCgo is adapted from (*builder).cgo in +// $GOROOT/src/cmd/go/build.go, but these features are unsupported: +// Objective C, CGOPKGPATH, CGO_FLAGS. +// +func runCgo(bp *build.Package, pkgdir, tmpdir string) (files, displayFiles []string, err error) { + cgoCPPFLAGS, _, _, _ := cflags(bp, true) + _, cgoexeCFLAGS, _, _ := cflags(bp, false) + + if len(bp.CgoPkgConfig) > 0 { + pcCFLAGS, err := pkgConfigFlags(bp) + if err != nil { + return nil, nil, err + } + cgoCPPFLAGS = append(cgoCPPFLAGS, pcCFLAGS...) + } + + // Allows including _cgo_export.h from .[ch] files in the package. + cgoCPPFLAGS = append(cgoCPPFLAGS, "-I", tmpdir) + + // _cgo_gotypes.go (displayed "C") contains the type definitions. + files = append(files, filepath.Join(tmpdir, "_cgo_gotypes.go")) + displayFiles = append(displayFiles, "C") + for _, fn := range bp.CgoFiles { + // "foo.cgo1.go" (displayed "foo.go") is the processed Go source. + f := cgoRe.ReplaceAllString(fn[:len(fn)-len("go")], "_") + files = append(files, filepath.Join(tmpdir, f+"cgo1.go")) + displayFiles = append(displayFiles, fn) + } + + var cgoflags []string + if bp.Goroot && bp.ImportPath == "runtime/cgo" { + cgoflags = append(cgoflags, "-import_runtime_cgo=false") + } + if bp.Goroot && bp.ImportPath == "runtime/race" || bp.ImportPath == "runtime/cgo" { + cgoflags = append(cgoflags, "-import_syscall=false") + } + + args := stringList( + "go", "tool", "cgo", "-objdir", tmpdir, cgoflags, "--", + cgoCPPFLAGS, cgoexeCFLAGS, bp.CgoFiles, + ) + if false { + log.Printf("Running cgo for package %q: %s (dir=%s)", bp.ImportPath, args, pkgdir) + } + cmd := exec.Command(args[0], args[1:]...) + cmd.Dir = pkgdir + cmd.Stdout = os.Stderr + cmd.Stderr = os.Stderr + if err := cmd.Run(); err != nil { + return nil, nil, fmt.Errorf("cgo failed: %s: %s", args, err) + } + + return files, displayFiles, nil +} + +// -- unmodified from 'go build' --------------------------------------- + +// Return the flags to use when invoking the C or C++ compilers, or cgo. +func cflags(p *build.Package, def bool) (cppflags, cflags, cxxflags, ldflags []string) { + var defaults string + if def { + defaults = "-g -O2" + } + + cppflags = stringList(envList("CGO_CPPFLAGS", ""), p.CgoCPPFLAGS) + cflags = stringList(envList("CGO_CFLAGS", defaults), p.CgoCFLAGS) + cxxflags = stringList(envList("CGO_CXXFLAGS", defaults), p.CgoCXXFLAGS) + ldflags = stringList(envList("CGO_LDFLAGS", defaults), p.CgoLDFLAGS) + return +} + +// envList returns the value of the given environment variable broken +// into fields, using the default value when the variable is empty. +func envList(key, def string) []string { + v := os.Getenv(key) + if v == "" { + v = def + } + return strings.Fields(v) +} + +// stringList's arguments should be a sequence of string or []string values. +// stringList flattens them into a single []string. +func stringList(args ...interface{}) []string { + var x []string + for _, arg := range args { + switch arg := arg.(type) { + case []string: + x = append(x, arg...) + case string: + x = append(x, arg) + default: + panic("stringList: invalid argument") + } + } + return x +} diff --git a/vendor/golang.org/x/tools/go/loader/cgo_pkgconfig.go b/vendor/golang.org/x/tools/go/loader/cgo_pkgconfig.go new file mode 100644 index 0000000..de57422 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/cgo_pkgconfig.go @@ -0,0 +1,39 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader + +import ( + "errors" + "fmt" + "go/build" + "os/exec" + "strings" +) + +// pkgConfig runs pkg-config with the specified arguments and returns the flags it prints. +func pkgConfig(mode string, pkgs []string) (flags []string, err error) { + cmd := exec.Command("pkg-config", append([]string{mode}, pkgs...)...) + out, err := cmd.CombinedOutput() + if err != nil { + s := fmt.Sprintf("%s failed: %v", strings.Join(cmd.Args, " "), err) + if len(out) > 0 { + s = fmt.Sprintf("%s: %s", s, out) + } + return nil, errors.New(s) + } + if len(out) > 0 { + flags = strings.Fields(string(out)) + } + return +} + +// pkgConfigFlags calls pkg-config if needed and returns the cflags +// needed to build the package. +func pkgConfigFlags(p *build.Package) (cflags []string, err error) { + if len(p.CgoPkgConfig) == 0 { + return nil, nil + } + return pkgConfig("--cflags", p.CgoPkgConfig) +} diff --git a/vendor/golang.org/x/tools/go/loader/doc.go b/vendor/golang.org/x/tools/go/loader/doc.go new file mode 100644 index 0000000..9b51c9e --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/doc.go @@ -0,0 +1,205 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package loader loads a complete Go program from source code, parsing +// and type-checking the initial packages plus their transitive closure +// of dependencies. The ASTs and the derived facts are retained for +// later use. +// +// THIS INTERFACE IS EXPERIMENTAL AND IS LIKELY TO CHANGE. +// +// The package defines two primary types: Config, which specifies a +// set of initial packages to load and various other options; and +// Program, which is the result of successfully loading the packages +// specified by a configuration. +// +// The configuration can be set directly, but *Config provides various +// convenience methods to simplify the common cases, each of which can +// be called any number of times. Finally, these are followed by a +// call to Load() to actually load and type-check the program. +// +// var conf loader.Config +// +// // Use the command-line arguments to specify +// // a set of initial packages to load from source. +// // See FromArgsUsage for help. +// rest, err := conf.FromArgs(os.Args[1:], wantTests) +// +// // Parse the specified files and create an ad hoc package with path "foo". +// // All files must have the same 'package' declaration. +// conf.CreateFromFilenames("foo", "foo.go", "bar.go") +// +// // Create an ad hoc package with path "foo" from +// // the specified already-parsed files. +// // All ASTs must have the same 'package' declaration. +// conf.CreateFromFiles("foo", parsedFiles) +// +// // Add "runtime" to the set of packages to be loaded. +// conf.Import("runtime") +// +// // Adds "fmt" and "fmt_test" to the set of packages +// // to be loaded. "fmt" will include *_test.go files. +// conf.ImportWithTests("fmt") +// +// // Finally, load all the packages specified by the configuration. +// prog, err := conf.Load() +// +// See examples_test.go for examples of API usage. +// +// +// CONCEPTS AND TERMINOLOGY +// +// The WORKSPACE is the set of packages accessible to the loader. The +// workspace is defined by Config.Build, a *build.Context. The +// default context treats subdirectories of $GOROOT and $GOPATH as +// packages, but this behavior may be overridden. +// +// An AD HOC package is one specified as a set of source files on the +// command line. In the simplest case, it may consist of a single file +// such as $GOROOT/src/net/http/triv.go. +// +// EXTERNAL TEST packages are those comprised of a set of *_test.go +// files all with the same 'package foo_test' declaration, all in the +// same directory. (go/build.Package calls these files XTestFiles.) +// +// An IMPORTABLE package is one that can be referred to by some import +// spec. Every importable package is uniquely identified by its +// PACKAGE PATH or just PATH, a string such as "fmt", "encoding/json", +// or "cmd/vendor/golang.org/x/arch/x86/x86asm". A package path +// typically denotes a subdirectory of the workspace. +// +// An import declaration uses an IMPORT PATH to refer to a package. +// Most import declarations use the package path as the import path. +// +// Due to VENDORING (https://golang.org/s/go15vendor), the +// interpretation of an import path may depend on the directory in which +// it appears. To resolve an import path to a package path, go/build +// must search the enclosing directories for a subdirectory named +// "vendor". +// +// ad hoc packages and external test packages are NON-IMPORTABLE. The +// path of an ad hoc package is inferred from the package +// declarations of its files and is therefore not a unique package key. +// For example, Config.CreatePkgs may specify two initial ad hoc +// packages, both with path "main". +// +// An AUGMENTED package is an importable package P plus all the +// *_test.go files with same 'package foo' declaration as P. +// (go/build.Package calls these files TestFiles.) +// +// The INITIAL packages are those specified in the configuration. A +// DEPENDENCY is a package loaded to satisfy an import in an initial +// package or another dependency. +// +package loader + +// IMPLEMENTATION NOTES +// +// 'go test', in-package test files, and import cycles +// --------------------------------------------------- +// +// An external test package may depend upon members of the augmented +// package that are not in the unaugmented package, such as functions +// that expose internals. (See bufio/export_test.go for an example.) +// So, the loader must ensure that for each external test package +// it loads, it also augments the corresponding non-test package. +// +// The import graph over n unaugmented packages must be acyclic; the +// import graph over n-1 unaugmented packages plus one augmented +// package must also be acyclic. ('go test' relies on this.) But the +// import graph over n augmented packages may contain cycles. +// +// First, all the (unaugmented) non-test packages and their +// dependencies are imported in the usual way; the loader reports an +// error if it detects an import cycle. +// +// Then, each package P for which testing is desired is augmented by +// the list P' of its in-package test files, by calling +// (*types.Checker).Files. This arrangement ensures that P' may +// reference definitions within P, but P may not reference definitions +// within P'. Furthermore, P' may import any other package, including +// ones that depend upon P, without an import cycle error. +// +// Consider two packages A and B, both of which have lists of +// in-package test files we'll call A' and B', and which have the +// following import graph edges: +// B imports A +// B' imports A +// A' imports B +// This last edge would be expected to create an error were it not +// for the special type-checking discipline above. +// Cycles of size greater than two are possible. For example: +// compress/bzip2/bzip2_test.go (package bzip2) imports "io/ioutil" +// io/ioutil/tempfile_test.go (package ioutil) imports "regexp" +// regexp/exec_test.go (package regexp) imports "compress/bzip2" +// +// +// Concurrency +// ----------- +// +// Let us define the import dependency graph as follows. Each node is a +// list of files passed to (Checker).Files at once. Many of these lists +// are the production code of an importable Go package, so those nodes +// are labelled by the package's path. The remaining nodes are +// ad hoc packages and lists of in-package *_test.go files that augment +// an importable package; those nodes have no label. +// +// The edges of the graph represent import statements appearing within a +// file. An edge connects a node (a list of files) to the node it +// imports, which is importable and thus always labelled. +// +// Loading is controlled by this dependency graph. +// +// To reduce I/O latency, we start loading a package's dependencies +// asynchronously as soon as we've parsed its files and enumerated its +// imports (scanImports). This performs a preorder traversal of the +// import dependency graph. +// +// To exploit hardware parallelism, we type-check unrelated packages in +// parallel, where "unrelated" means not ordered by the partial order of +// the import dependency graph. +// +// We use a concurrency-safe non-blocking cache (importer.imported) to +// record the results of type-checking, whether success or failure. An +// entry is created in this cache by startLoad the first time the +// package is imported. The first goroutine to request an entry becomes +// responsible for completing the task and broadcasting completion to +// subsequent requestors, which block until then. +// +// Type checking occurs in (parallel) postorder: we cannot type-check a +// set of files until we have loaded and type-checked all of their +// immediate dependencies (and thus all of their transitive +// dependencies). If the input were guaranteed free of import cycles, +// this would be trivial: we could simply wait for completion of the +// dependencies and then invoke the typechecker. +// +// But as we saw in the 'go test' section above, some cycles in the +// import graph over packages are actually legal, so long as the +// cycle-forming edge originates in the in-package test files that +// augment the package. This explains why the nodes of the import +// dependency graph are not packages, but lists of files: the unlabelled +// nodes avoid the cycles. Consider packages A and B where B imports A +// and A's in-package tests AT import B. The naively constructed import +// graph over packages would contain a cycle (A+AT) --> B --> (A+AT) but +// the graph over lists of files is AT --> B --> A, where AT is an +// unlabelled node. +// +// Awaiting completion of the dependencies in a cyclic graph would +// deadlock, so we must materialize the import dependency graph (as +// importer.graph) and check whether each import edge forms a cycle. If +// x imports y, and the graph already contains a path from y to x, then +// there is an import cycle, in which case the processing of x must not +// wait for the completion of processing of y. +// +// When the type-checker makes a callback (doImport) to the loader for a +// given import edge, there are two possible cases. In the normal case, +// the dependency has already been completely type-checked; doImport +// does a cache lookup and returns it. In the cyclic case, the entry in +// the cache is still necessarily incomplete, indicating a cycle. We +// perform the cycle check again to obtain the error message, and return +// the error. +// +// The result of using concurrency is about a 2.5x speedup for stdlib_test. + +// TODO(adonovan): overhaul the package documentation. diff --git a/vendor/golang.org/x/tools/go/loader/example_test.go b/vendor/golang.org/x/tools/go/loader/example_test.go new file mode 100644 index 0000000..88adde3 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/example_test.go @@ -0,0 +1,179 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build go1.8,!go1.9 // TODO(adonovan) determine which versions we need to test here +// +build !windows + +package loader_test + +import ( + "fmt" + "go/token" + "log" + "path/filepath" + "runtime" + "sort" + "strings" + + "golang.org/x/tools/go/loader" +) + +func printProgram(prog *loader.Program) { + // Created packages are the initial packages specified by a call + // to CreateFromFilenames or CreateFromFiles. + var names []string + for _, info := range prog.Created { + names = append(names, info.Pkg.Path()) + } + fmt.Printf("created: %s\n", names) + + // Imported packages are the initial packages specified by a + // call to Import or ImportWithTests. + names = nil + for _, info := range prog.Imported { + if strings.Contains(info.Pkg.Path(), "internal") { + continue // skip, to reduce fragility + } + names = append(names, info.Pkg.Path()) + } + sort.Strings(names) + fmt.Printf("imported: %s\n", names) + + // InitialPackages contains the union of created and imported. + names = nil + for _, info := range prog.InitialPackages() { + names = append(names, info.Pkg.Path()) + } + sort.Strings(names) + fmt.Printf("initial: %s\n", names) + + // AllPackages contains all initial packages and their dependencies. + names = nil + for pkg := range prog.AllPackages { + names = append(names, pkg.Path()) + } + sort.Strings(names) + fmt.Printf("all: %s\n", names) +} + +func printFilenames(fset *token.FileSet, info *loader.PackageInfo) { + var names []string + for _, f := range info.Files { + names = append(names, filepath.Base(fset.File(f.Pos()).Name())) + } + fmt.Printf("%s.Files: %s\n", info.Pkg.Path(), names) +} + +// This example loads a set of packages and all of their dependencies +// from a typical command-line. FromArgs parses a command line and +// makes calls to the other methods of Config shown in the examples that +// follow. +func ExampleConfig_FromArgs() { + args := []string{"mytool", "unicode/utf8", "errors", "runtime", "--", "foo", "bar"} + const wantTests = false + + var conf loader.Config + rest, err := conf.FromArgs(args[1:], wantTests) + prog, err := conf.Load() + if err != nil { + log.Fatal(err) + } + + fmt.Printf("rest: %s\n", rest) + printProgram(prog) + // Output: + // rest: [foo bar] + // created: [] + // imported: [errors runtime unicode/utf8] + // initial: [errors runtime unicode/utf8] + // all: [errors runtime runtime/internal/atomic runtime/internal/sys unicode/utf8 unsafe] +} + +// This example creates and type-checks a single package (without tests) +// from a list of filenames, and loads all of its dependencies. +// (The input files are actually only a small part of the math/cmplx package.) +func ExampleConfig_CreateFromFilenames() { + var conf loader.Config + conf.CreateFromFilenames("math/cmplx", + filepath.Join(runtime.GOROOT(), "src/math/cmplx/abs.go"), + filepath.Join(runtime.GOROOT(), "src/math/cmplx/sin.go")) + prog, err := conf.Load() + if err != nil { + log.Fatal(err) + } + + printProgram(prog) + // Output: + // created: [math/cmplx] + // imported: [] + // initial: [math/cmplx] + // all: [math math/cmplx unsafe] +} + +// In the examples below, for stability, the chosen packages are +// relatively small, platform-independent, and low-level (and thus +// infrequently changing). +// The strconv package has internal and external tests. + +const hello = `package main + +import "fmt" + +func main() { + fmt.Println("Hello, world.") +} +` + +// This example creates and type-checks a package from a list of +// already-parsed files, and loads all its dependencies. +func ExampleConfig_CreateFromFiles() { + var conf loader.Config + f, err := conf.ParseFile("hello.go", hello) + if err != nil { + log.Fatal(err) + } + conf.CreateFromFiles("hello", f) + prog, err := conf.Load() + if err != nil { + log.Fatal(err) + } + + printProgram(prog) + printFilenames(prog.Fset, prog.Package("strconv")) + // Output: + // created: [hello] + // imported: [] + // initial: [hello] + // all: [errors fmt hello internal/race io math os reflect runtime runtime/internal/atomic runtime/internal/sys strconv sync sync/atomic syscall time unicode/utf8 unsafe] + // strconv.Files: [atob.go atof.go atoi.go decimal.go doc.go extfloat.go ftoa.go isprint.go itoa.go quote.go] +} + +// This example imports three packages, including the tests for one of +// them, and loads all their dependencies. +func ExampleConfig_Import() { + // ImportWithTest("strconv") causes strconv to include + // internal_test.go, and creates an external test package, + // strconv_test. + // (Compare with the example of CreateFromFiles.) + + var conf loader.Config + conf.Import("unicode/utf8") + conf.Import("errors") + conf.ImportWithTests("strconv") + prog, err := conf.Load() + if err != nil { + log.Fatal(err) + } + + printProgram(prog) + printFilenames(prog.Fset, prog.Package("strconv")) + printFilenames(prog.Fset, prog.Package("strconv_test")) + // Output: + // created: [strconv_test] + // imported: [errors strconv unicode/utf8] + // initial: [errors strconv strconv_test unicode/utf8] + // all: [bufio bytes errors flag fmt internal/race io log math math/rand os reflect runtime runtime/debug runtime/internal/atomic runtime/internal/sys runtime/trace sort strconv strconv_test strings sync sync/atomic syscall testing time unicode unicode/utf8 unsafe] + // strconv.Files: [atob.go atof.go atoi.go decimal.go doc.go extfloat.go ftoa.go isprint.go itoa.go quote.go internal_test.go] + // strconv_test.Files: [atob_test.go atof_test.go atoi_test.go decimal_test.go example_test.go fp_test.go ftoa_test.go itoa_test.go quote_test.go strconv_test.go] +} diff --git a/vendor/golang.org/x/tools/go/loader/loader.go b/vendor/golang.org/x/tools/go/loader/loader.go new file mode 100644 index 0000000..de756f7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/loader.go @@ -0,0 +1,1077 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader + +// See doc.go for package documentation and implementation notes. + +import ( + "errors" + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "go/types" + "os" + "path/filepath" + "sort" + "strings" + "sync" + "time" + + "golang.org/x/tools/go/ast/astutil" +) + +var ignoreVendor build.ImportMode + +const trace = false // show timing info for type-checking + +// Config specifies the configuration for loading a whole program from +// Go source code. +// The zero value for Config is a ready-to-use default configuration. +type Config struct { + // Fset is the file set for the parser to use when loading the + // program. If nil, it may be lazily initialized by any + // method of Config. + Fset *token.FileSet + + // ParserMode specifies the mode to be used by the parser when + // loading source packages. + ParserMode parser.Mode + + // TypeChecker contains options relating to the type checker. + // + // The supplied IgnoreFuncBodies is not used; the effective + // value comes from the TypeCheckFuncBodies func below. + // The supplied Import function is not used either. + TypeChecker types.Config + + // TypeCheckFuncBodies is a predicate over package paths. + // A package for which the predicate is false will + // have its package-level declarations type checked, but not + // its function bodies; this can be used to quickly load + // dependencies from source. If nil, all func bodies are type + // checked. + TypeCheckFuncBodies func(path string) bool + + // If Build is non-nil, it is used to locate source packages. + // Otherwise &build.Default is used. + // + // By default, cgo is invoked to preprocess Go files that + // import the fake package "C". This behaviour can be + // disabled by setting CGO_ENABLED=0 in the environment prior + // to startup, or by setting Build.CgoEnabled=false. + Build *build.Context + + // The current directory, used for resolving relative package + // references such as "./go/loader". If empty, os.Getwd will be + // used instead. + Cwd string + + // If DisplayPath is non-nil, it is used to transform each + // file name obtained from Build.Import(). This can be used + // to prevent a virtualized build.Config's file names from + // leaking into the user interface. + DisplayPath func(path string) string + + // If AllowErrors is true, Load will return a Program even + // if some of the its packages contained I/O, parser or type + // errors; such errors are accessible via PackageInfo.Errors. If + // false, Load will fail if any package had an error. + AllowErrors bool + + // CreatePkgs specifies a list of non-importable initial + // packages to create. The resulting packages will appear in + // the corresponding elements of the Program.Created slice. + CreatePkgs []PkgSpec + + // ImportPkgs specifies a set of initial packages to load. + // The map keys are package paths. + // + // The map value indicates whether to load tests. If true, Load + // will add and type-check two lists of files to the package: + // non-test files followed by in-package *_test.go files. In + // addition, it will append the external test package (if any) + // to Program.Created. + ImportPkgs map[string]bool + + // FindPackage is called during Load to create the build.Package + // for a given import path from a given directory. + // If FindPackage is nil, (*build.Context).Import is used. + // A client may use this hook to adapt to a proprietary build + // system that does not follow the "go build" layout + // conventions, for example. + // + // It must be safe to call concurrently from multiple goroutines. + FindPackage func(ctxt *build.Context, importPath, fromDir string, mode build.ImportMode) (*build.Package, error) + + // AfterTypeCheck is called immediately after a list of files + // has been type-checked and appended to info.Files. + // + // This optional hook function is the earliest opportunity for + // the client to observe the output of the type checker, + // which may be useful to reduce analysis latency when loading + // a large program. + // + // The function is permitted to modify info.Info, for instance + // to clear data structures that are no longer needed, which can + // dramatically reduce peak memory consumption. + // + // The function may be called twice for the same PackageInfo: + // once for the files of the package and again for the + // in-package test files. + // + // It must be safe to call concurrently from multiple goroutines. + AfterTypeCheck func(info *PackageInfo, files []*ast.File) +} + +// A PkgSpec specifies a non-importable package to be created by Load. +// Files are processed first, but typically only one of Files and +// Filenames is provided. The path needn't be globally unique. +// +// For vendoring purposes, the package's directory is the one that +// contains the first file. +type PkgSpec struct { + Path string // package path ("" => use package declaration) + Files []*ast.File // ASTs of already-parsed files + Filenames []string // names of files to be parsed +} + +// A Program is a Go program loaded from source as specified by a Config. +type Program struct { + Fset *token.FileSet // the file set for this program + + // Created[i] contains the initial package whose ASTs or + // filenames were supplied by Config.CreatePkgs[i], followed by + // the external test package, if any, of each package in + // Config.ImportPkgs ordered by ImportPath. + // + // NOTE: these files must not import "C". Cgo preprocessing is + // only performed on imported packages, not ad hoc packages. + // + // TODO(adonovan): we need to copy and adapt the logic of + // goFilesPackage (from $GOROOT/src/cmd/go/build.go) and make + // Config.Import and Config.Create methods return the same kind + // of entity, essentially a build.Package. + // Perhaps we can even reuse that type directly. + Created []*PackageInfo + + // Imported contains the initially imported packages, + // as specified by Config.ImportPkgs. + Imported map[string]*PackageInfo + + // AllPackages contains the PackageInfo of every package + // encountered by Load: all initial packages and all + // dependencies, including incomplete ones. + AllPackages map[*types.Package]*PackageInfo + + // importMap is the canonical mapping of package paths to + // packages. It contains all Imported initial packages, but not + // Created ones, and all imported dependencies. + importMap map[string]*types.Package +} + +// PackageInfo holds the ASTs and facts derived by the type-checker +// for a single package. +// +// Not mutated once exposed via the API. +// +type PackageInfo struct { + Pkg *types.Package + Importable bool // true if 'import "Pkg.Path()"' would resolve to this + TransitivelyErrorFree bool // true if Pkg and all its dependencies are free of errors + Files []*ast.File // syntax trees for the package's files + Errors []error // non-nil if the package had errors + types.Info // type-checker deductions. + dir string // package directory + + checker *types.Checker // transient type-checker state + errorFunc func(error) +} + +func (info *PackageInfo) String() string { return info.Pkg.Path() } + +func (info *PackageInfo) appendError(err error) { + if info.errorFunc != nil { + info.errorFunc(err) + } else { + fmt.Fprintln(os.Stderr, err) + } + info.Errors = append(info.Errors, err) +} + +func (conf *Config) fset() *token.FileSet { + if conf.Fset == nil { + conf.Fset = token.NewFileSet() + } + return conf.Fset +} + +// ParseFile is a convenience function (intended for testing) that invokes +// the parser using the Config's FileSet, which is initialized if nil. +// +// src specifies the parser input as a string, []byte, or io.Reader, and +// filename is its apparent name. If src is nil, the contents of +// filename are read from the file system. +// +func (conf *Config) ParseFile(filename string, src interface{}) (*ast.File, error) { + // TODO(adonovan): use conf.build() etc like parseFiles does. + return parser.ParseFile(conf.fset(), filename, src, conf.ParserMode) +} + +// FromArgsUsage is a partial usage message that applications calling +// FromArgs may wish to include in their -help output. +const FromArgsUsage = ` +<args> is a list of arguments denoting a set of initial packages. +It may take one of two forms: + +1. A list of *.go source files. + + All of the specified files are loaded, parsed and type-checked + as a single package. All the files must belong to the same directory. + +2. A list of import paths, each denoting a package. + + The package's directory is found relative to the $GOROOT and + $GOPATH using similar logic to 'go build', and the *.go files in + that directory are loaded, parsed and type-checked as a single + package. + + In addition, all *_test.go files in the directory are then loaded + and parsed. Those files whose package declaration equals that of + the non-*_test.go files are included in the primary package. Test + files whose package declaration ends with "_test" are type-checked + as another package, the 'external' test package, so that a single + import path may denote two packages. (Whether this behaviour is + enabled is tool-specific, and may depend on additional flags.) + +A '--' argument terminates the list of packages. +` + +// FromArgs interprets args as a set of initial packages to load from +// source and updates the configuration. It returns the list of +// unconsumed arguments. +// +// It is intended for use in command-line interfaces that require a +// set of initial packages to be specified; see FromArgsUsage message +// for details. +// +// Only superficial errors are reported at this stage; errors dependent +// on I/O are detected during Load. +// +func (conf *Config) FromArgs(args []string, xtest bool) ([]string, error) { + var rest []string + for i, arg := range args { + if arg == "--" { + rest = args[i+1:] + args = args[:i] + break // consume "--" and return the remaining args + } + } + + if len(args) > 0 && strings.HasSuffix(args[0], ".go") { + // Assume args is a list of a *.go files + // denoting a single ad hoc package. + for _, arg := range args { + if !strings.HasSuffix(arg, ".go") { + return nil, fmt.Errorf("named files must be .go files: %s", arg) + } + } + conf.CreateFromFilenames("", args...) + } else { + // Assume args are directories each denoting a + // package and (perhaps) an external test, iff xtest. + for _, arg := range args { + if xtest { + conf.ImportWithTests(arg) + } else { + conf.Import(arg) + } + } + } + + return rest, nil +} + +// CreateFromFilenames is a convenience function that adds +// a conf.CreatePkgs entry to create a package of the specified *.go +// files. +// +func (conf *Config) CreateFromFilenames(path string, filenames ...string) { + conf.CreatePkgs = append(conf.CreatePkgs, PkgSpec{Path: path, Filenames: filenames}) +} + +// CreateFromFiles is a convenience function that adds a conf.CreatePkgs +// entry to create package of the specified path and parsed files. +// +func (conf *Config) CreateFromFiles(path string, files ...*ast.File) { + conf.CreatePkgs = append(conf.CreatePkgs, PkgSpec{Path: path, Files: files}) +} + +// ImportWithTests is a convenience function that adds path to +// ImportPkgs, the set of initial source packages located relative to +// $GOPATH. The package will be augmented by any *_test.go files in +// its directory that contain a "package x" (not "package x_test") +// declaration. +// +// In addition, if any *_test.go files contain a "package x_test" +// declaration, an additional package comprising just those files will +// be added to CreatePkgs. +// +func (conf *Config) ImportWithTests(path string) { conf.addImport(path, true) } + +// Import is a convenience function that adds path to ImportPkgs, the +// set of initial packages that will be imported from source. +// +func (conf *Config) Import(path string) { conf.addImport(path, false) } + +func (conf *Config) addImport(path string, tests bool) { + if path == "C" { + return // ignore; not a real package + } + if conf.ImportPkgs == nil { + conf.ImportPkgs = make(map[string]bool) + } + conf.ImportPkgs[path] = conf.ImportPkgs[path] || tests +} + +// PathEnclosingInterval returns the PackageInfo and ast.Node that +// contain source interval [start, end), and all the node's ancestors +// up to the AST root. It searches all ast.Files of all packages in prog. +// exact is defined as for astutil.PathEnclosingInterval. +// +// The zero value is returned if not found. +// +func (prog *Program) PathEnclosingInterval(start, end token.Pos) (pkg *PackageInfo, path []ast.Node, exact bool) { + for _, info := range prog.AllPackages { + for _, f := range info.Files { + if f.Pos() == token.NoPos { + // This can happen if the parser saw + // too many errors and bailed out. + // (Use parser.AllErrors to prevent that.) + continue + } + if !tokenFileContainsPos(prog.Fset.File(f.Pos()), start) { + continue + } + if path, exact := astutil.PathEnclosingInterval(f, start, end); path != nil { + return info, path, exact + } + } + } + return nil, nil, false +} + +// InitialPackages returns a new slice containing the set of initial +// packages (Created + Imported) in unspecified order. +// +func (prog *Program) InitialPackages() []*PackageInfo { + infos := make([]*PackageInfo, 0, len(prog.Created)+len(prog.Imported)) + infos = append(infos, prog.Created...) + for _, info := range prog.Imported { + infos = append(infos, info) + } + return infos +} + +// Package returns the ASTs and results of type checking for the +// specified package. +func (prog *Program) Package(path string) *PackageInfo { + if info, ok := prog.AllPackages[prog.importMap[path]]; ok { + return info + } + for _, info := range prog.Created { + if path == info.Pkg.Path() { + return info + } + } + return nil +} + +// ---------- Implementation ---------- + +// importer holds the working state of the algorithm. +type importer struct { + conf *Config // the client configuration + start time.Time // for logging + + progMu sync.Mutex // guards prog + prog *Program // the resulting program + + // findpkg is a memoization of FindPackage. + findpkgMu sync.Mutex // guards findpkg + findpkg map[findpkgKey]*findpkgValue + + importedMu sync.Mutex // guards imported + imported map[string]*importInfo // all imported packages (incl. failures) by import path + + // import dependency graph: graph[x][y] => x imports y + // + // Since non-importable packages cannot be cyclic, we ignore + // their imports, thus we only need the subgraph over importable + // packages. Nodes are identified by their import paths. + graphMu sync.Mutex + graph map[string]map[string]bool +} + +type findpkgKey struct { + importPath string + fromDir string + mode build.ImportMode +} + +type findpkgValue struct { + ready chan struct{} // closed to broadcast readiness + bp *build.Package + err error +} + +// importInfo tracks the success or failure of a single import. +// +// Upon completion, exactly one of info and err is non-nil: +// info on successful creation of a package, err otherwise. +// A successful package may still contain type errors. +// +type importInfo struct { + path string // import path + info *PackageInfo // results of typechecking (including errors) + complete chan struct{} // closed to broadcast that info is set. +} + +// awaitCompletion blocks until ii is complete, +// i.e. the info field is safe to inspect. +func (ii *importInfo) awaitCompletion() { + <-ii.complete // wait for close +} + +// Complete marks ii as complete. +// Its info and err fields will not be subsequently updated. +func (ii *importInfo) Complete(info *PackageInfo) { + if info == nil { + panic("info == nil") + } + ii.info = info + close(ii.complete) +} + +type importError struct { + path string // import path + err error // reason for failure to create a package +} + +// Load creates the initial packages specified by conf.{Create,Import}Pkgs, +// loading their dependencies packages as needed. +// +// On success, Load returns a Program containing a PackageInfo for +// each package. On failure, it returns an error. +// +// If AllowErrors is true, Load will return a Program even if some +// packages contained I/O, parser or type errors, or if dependencies +// were missing. (Such errors are accessible via PackageInfo.Errors. If +// false, Load will fail if any package had an error. +// +// It is an error if no packages were loaded. +// +func (conf *Config) Load() (*Program, error) { + // Create a simple default error handler for parse/type errors. + if conf.TypeChecker.Error == nil { + conf.TypeChecker.Error = func(e error) { fmt.Fprintln(os.Stderr, e) } + } + + // Set default working directory for relative package references. + if conf.Cwd == "" { + var err error + conf.Cwd, err = os.Getwd() + if err != nil { + return nil, err + } + } + + // Install default FindPackage hook using go/build logic. + if conf.FindPackage == nil { + conf.FindPackage = (*build.Context).Import + } + + prog := &Program{ + Fset: conf.fset(), + Imported: make(map[string]*PackageInfo), + importMap: make(map[string]*types.Package), + AllPackages: make(map[*types.Package]*PackageInfo), + } + + imp := importer{ + conf: conf, + prog: prog, + findpkg: make(map[findpkgKey]*findpkgValue), + imported: make(map[string]*importInfo), + start: time.Now(), + graph: make(map[string]map[string]bool), + } + + // -- loading proper (concurrent phase) -------------------------------- + + var errpkgs []string // packages that contained errors + + // Load the initially imported packages and their dependencies, + // in parallel. + // No vendor check on packages imported from the command line. + infos, importErrors := imp.importAll("", conf.Cwd, conf.ImportPkgs, ignoreVendor) + for _, ie := range importErrors { + conf.TypeChecker.Error(ie.err) // failed to create package + errpkgs = append(errpkgs, ie.path) + } + for _, info := range infos { + prog.Imported[info.Pkg.Path()] = info + } + + // Augment the designated initial packages by their tests. + // Dependencies are loaded in parallel. + var xtestPkgs []*build.Package + for importPath, augment := range conf.ImportPkgs { + if !augment { + continue + } + + // No vendor check on packages imported from command line. + bp, err := imp.findPackage(importPath, conf.Cwd, ignoreVendor) + if err != nil { + // Package not found, or can't even parse package declaration. + // Already reported by previous loop; ignore it. + continue + } + + // Needs external test package? + if len(bp.XTestGoFiles) > 0 { + xtestPkgs = append(xtestPkgs, bp) + } + + // Consult the cache using the canonical package path. + path := bp.ImportPath + imp.importedMu.Lock() // (unnecessary, we're sequential here) + ii, ok := imp.imported[path] + // Paranoid checks added due to issue #11012. + if !ok { + // Unreachable. + // The previous loop called importAll and thus + // startLoad for each path in ImportPkgs, which + // populates imp.imported[path] with a non-zero value. + panic(fmt.Sprintf("imported[%q] not found", path)) + } + if ii == nil { + // Unreachable. + // The ii values in this loop are the same as in + // the previous loop, which enforced the invariant + // that at least one of ii.err and ii.info is non-nil. + panic(fmt.Sprintf("imported[%q] == nil", path)) + } + if ii.info == nil { + // Unreachable. + // awaitCompletion has the postcondition + // ii.info != nil. + panic(fmt.Sprintf("imported[%q].info = nil", path)) + } + info := ii.info + imp.importedMu.Unlock() + + // Parse the in-package test files. + files, errs := imp.conf.parsePackageFiles(bp, 't') + for _, err := range errs { + info.appendError(err) + } + + // The test files augmenting package P cannot be imported, + // but may import packages that import P, + // so we must disable the cycle check. + imp.addFiles(info, files, false) + } + + createPkg := func(path, dir string, files []*ast.File, errs []error) { + info := imp.newPackageInfo(path, dir) + for _, err := range errs { + info.appendError(err) + } + + // Ad hoc packages are non-importable, + // so no cycle check is needed. + // addFiles loads dependencies in parallel. + imp.addFiles(info, files, false) + prog.Created = append(prog.Created, info) + } + + // Create packages specified by conf.CreatePkgs. + for _, cp := range conf.CreatePkgs { + files, errs := parseFiles(conf.fset(), conf.build(), nil, conf.Cwd, cp.Filenames, conf.ParserMode) + files = append(files, cp.Files...) + + path := cp.Path + if path == "" { + if len(files) > 0 { + path = files[0].Name.Name + } else { + path = "(unnamed)" + } + } + + dir := conf.Cwd + if len(files) > 0 && files[0].Pos().IsValid() { + dir = filepath.Dir(conf.fset().File(files[0].Pos()).Name()) + } + createPkg(path, dir, files, errs) + } + + // Create external test packages. + sort.Sort(byImportPath(xtestPkgs)) + for _, bp := range xtestPkgs { + files, errs := imp.conf.parsePackageFiles(bp, 'x') + createPkg(bp.ImportPath+"_test", bp.Dir, files, errs) + } + + // -- finishing up (sequential) ---------------------------------------- + + if len(prog.Imported)+len(prog.Created) == 0 { + return nil, errors.New("no initial packages were loaded") + } + + // Create infos for indirectly imported packages. + // e.g. incomplete packages without syntax, loaded from export data. + for _, obj := range prog.importMap { + info := prog.AllPackages[obj] + if info == nil { + prog.AllPackages[obj] = &PackageInfo{Pkg: obj, Importable: true} + } else { + // finished + info.checker = nil + info.errorFunc = nil + } + } + + if !conf.AllowErrors { + // Report errors in indirectly imported packages. + for _, info := range prog.AllPackages { + if len(info.Errors) > 0 { + errpkgs = append(errpkgs, info.Pkg.Path()) + } + } + if errpkgs != nil { + var more string + if len(errpkgs) > 3 { + more = fmt.Sprintf(" and %d more", len(errpkgs)-3) + errpkgs = errpkgs[:3] + } + return nil, fmt.Errorf("couldn't load packages due to errors: %s%s", + strings.Join(errpkgs, ", "), more) + } + } + + markErrorFreePackages(prog.AllPackages) + + return prog, nil +} + +type byImportPath []*build.Package + +func (b byImportPath) Len() int { return len(b) } +func (b byImportPath) Less(i, j int) bool { return b[i].ImportPath < b[j].ImportPath } +func (b byImportPath) Swap(i, j int) { b[i], b[j] = b[j], b[i] } + +// markErrorFreePackages sets the TransitivelyErrorFree flag on all +// applicable packages. +func markErrorFreePackages(allPackages map[*types.Package]*PackageInfo) { + // Build the transpose of the import graph. + importedBy := make(map[*types.Package]map[*types.Package]bool) + for P := range allPackages { + for _, Q := range P.Imports() { + clients, ok := importedBy[Q] + if !ok { + clients = make(map[*types.Package]bool) + importedBy[Q] = clients + } + clients[P] = true + } + } + + // Find all packages reachable from some error package. + reachable := make(map[*types.Package]bool) + var visit func(*types.Package) + visit = func(p *types.Package) { + if !reachable[p] { + reachable[p] = true + for q := range importedBy[p] { + visit(q) + } + } + } + for _, info := range allPackages { + if len(info.Errors) > 0 { + visit(info.Pkg) + } + } + + // Mark the others as "transitively error-free". + for _, info := range allPackages { + if !reachable[info.Pkg] { + info.TransitivelyErrorFree = true + } + } +} + +// build returns the effective build context. +func (conf *Config) build() *build.Context { + if conf.Build != nil { + return conf.Build + } + return &build.Default +} + +// parsePackageFiles enumerates the files belonging to package path, +// then loads, parses and returns them, plus a list of I/O or parse +// errors that were encountered. +// +// 'which' indicates which files to include: +// 'g': include non-test *.go source files (GoFiles + processed CgoFiles) +// 't': include in-package *_test.go source files (TestGoFiles) +// 'x': include external *_test.go source files. (XTestGoFiles) +// +func (conf *Config) parsePackageFiles(bp *build.Package, which rune) ([]*ast.File, []error) { + if bp.ImportPath == "unsafe" { + return nil, nil + } + var filenames []string + switch which { + case 'g': + filenames = bp.GoFiles + case 't': + filenames = bp.TestGoFiles + case 'x': + filenames = bp.XTestGoFiles + default: + panic(which) + } + + files, errs := parseFiles(conf.fset(), conf.build(), conf.DisplayPath, bp.Dir, filenames, conf.ParserMode) + + // Preprocess CgoFiles and parse the outputs (sequentially). + if which == 'g' && bp.CgoFiles != nil { + cgofiles, err := processCgoFiles(bp, conf.fset(), conf.DisplayPath, conf.ParserMode) + if err != nil { + errs = append(errs, err) + } else { + files = append(files, cgofiles...) + } + } + + return files, errs +} + +// doImport imports the package denoted by path. +// It implements the types.Importer signature. +// +// It returns an error if a package could not be created +// (e.g. go/build or parse error), but type errors are reported via +// the types.Config.Error callback (the first of which is also saved +// in the package's PackageInfo). +// +// Idempotent. +// +func (imp *importer) doImport(from *PackageInfo, to string) (*types.Package, error) { + if to == "C" { + // This should be unreachable, but ad hoc packages are + // not currently subject to cgo preprocessing. + // See https://github.com/golang/go/issues/11627. + return nil, fmt.Errorf(`the loader doesn't cgo-process ad hoc packages like %q; see Go issue 11627`, + from.Pkg.Path()) + } + + bp, err := imp.findPackage(to, from.dir, 0) + if err != nil { + return nil, err + } + + // The standard unsafe package is handled specially, + // and has no PackageInfo. + if bp.ImportPath == "unsafe" { + return types.Unsafe, nil + } + + // Look for the package in the cache using its canonical path. + path := bp.ImportPath + imp.importedMu.Lock() + ii := imp.imported[path] + imp.importedMu.Unlock() + if ii == nil { + panic("internal error: unexpected import: " + path) + } + if ii.info != nil { + return ii.info.Pkg, nil + } + + // Import of incomplete package: this indicates a cycle. + fromPath := from.Pkg.Path() + if cycle := imp.findPath(path, fromPath); cycle != nil { + cycle = append([]string{fromPath}, cycle...) + return nil, fmt.Errorf("import cycle: %s", strings.Join(cycle, " -> ")) + } + + panic("internal error: import of incomplete (yet acyclic) package: " + fromPath) +} + +// findPackage locates the package denoted by the importPath in the +// specified directory. +func (imp *importer) findPackage(importPath, fromDir string, mode build.ImportMode) (*build.Package, error) { + // We use a non-blocking duplicate-suppressing cache (gopl.io §9.7) + // to avoid holding the lock around FindPackage. + key := findpkgKey{importPath, fromDir, mode} + imp.findpkgMu.Lock() + v, ok := imp.findpkg[key] + if ok { + // cache hit + imp.findpkgMu.Unlock() + + <-v.ready // wait for entry to become ready + } else { + // Cache miss: this goroutine becomes responsible for + // populating the map entry and broadcasting its readiness. + v = &findpkgValue{ready: make(chan struct{})} + imp.findpkg[key] = v + imp.findpkgMu.Unlock() + + ioLimit <- true + v.bp, v.err = imp.conf.FindPackage(imp.conf.build(), importPath, fromDir, mode) + <-ioLimit + + if _, ok := v.err.(*build.NoGoError); ok { + v.err = nil // empty directory is not an error + } + + close(v.ready) // broadcast ready condition + } + return v.bp, v.err +} + +// importAll loads, parses, and type-checks the specified packages in +// parallel and returns their completed importInfos in unspecified order. +// +// fromPath is the package path of the importing package, if it is +// importable, "" otherwise. It is used for cycle detection. +// +// fromDir is the directory containing the import declaration that +// caused these imports. +// +func (imp *importer) importAll(fromPath, fromDir string, imports map[string]bool, mode build.ImportMode) (infos []*PackageInfo, errors []importError) { + // TODO(adonovan): opt: do the loop in parallel once + // findPackage is non-blocking. + var pending []*importInfo + for importPath := range imports { + bp, err := imp.findPackage(importPath, fromDir, mode) + if err != nil { + errors = append(errors, importError{ + path: importPath, + err: err, + }) + continue + } + pending = append(pending, imp.startLoad(bp)) + } + + if fromPath != "" { + // We're loading a set of imports. + // + // We must record graph edges from the importing package + // to its dependencies, and check for cycles. + imp.graphMu.Lock() + deps, ok := imp.graph[fromPath] + if !ok { + deps = make(map[string]bool) + imp.graph[fromPath] = deps + } + for _, ii := range pending { + deps[ii.path] = true + } + imp.graphMu.Unlock() + } + + for _, ii := range pending { + if fromPath != "" { + if cycle := imp.findPath(ii.path, fromPath); cycle != nil { + // Cycle-forming import: we must not await its + // completion since it would deadlock. + // + // We don't record the error in ii since + // the error is really associated with the + // cycle-forming edge, not the package itself. + // (Also it would complicate the + // invariants of importPath completion.) + if trace { + fmt.Fprintf(os.Stderr, "import cycle: %q\n", cycle) + } + continue + } + } + ii.awaitCompletion() + infos = append(infos, ii.info) + } + + return infos, errors +} + +// findPath returns an arbitrary path from 'from' to 'to' in the import +// graph, or nil if there was none. +func (imp *importer) findPath(from, to string) []string { + imp.graphMu.Lock() + defer imp.graphMu.Unlock() + + seen := make(map[string]bool) + var search func(stack []string, importPath string) []string + search = func(stack []string, importPath string) []string { + if !seen[importPath] { + seen[importPath] = true + stack = append(stack, importPath) + if importPath == to { + return stack + } + for x := range imp.graph[importPath] { + if p := search(stack, x); p != nil { + return p + } + } + } + return nil + } + return search(make([]string, 0, 20), from) +} + +// startLoad initiates the loading, parsing and type-checking of the +// specified package and its dependencies, if it has not already begun. +// +// It returns an importInfo, not necessarily in a completed state. The +// caller must call awaitCompletion() before accessing its info field. +// +// startLoad is concurrency-safe and idempotent. +// +func (imp *importer) startLoad(bp *build.Package) *importInfo { + path := bp.ImportPath + imp.importedMu.Lock() + ii, ok := imp.imported[path] + if !ok { + ii = &importInfo{path: path, complete: make(chan struct{})} + imp.imported[path] = ii + go func() { + info := imp.load(bp) + ii.Complete(info) + }() + } + imp.importedMu.Unlock() + + return ii +} + +// load implements package loading by parsing Go source files +// located by go/build. +func (imp *importer) load(bp *build.Package) *PackageInfo { + info := imp.newPackageInfo(bp.ImportPath, bp.Dir) + info.Importable = true + files, errs := imp.conf.parsePackageFiles(bp, 'g') + for _, err := range errs { + info.appendError(err) + } + + imp.addFiles(info, files, true) + + imp.progMu.Lock() + imp.prog.importMap[bp.ImportPath] = info.Pkg + imp.progMu.Unlock() + + return info +} + +// addFiles adds and type-checks the specified files to info, loading +// their dependencies if needed. The order of files determines the +// package initialization order. It may be called multiple times on the +// same package. Errors are appended to the info.Errors field. +// +// cycleCheck determines whether the imports within files create +// dependency edges that should be checked for potential cycles. +// +func (imp *importer) addFiles(info *PackageInfo, files []*ast.File, cycleCheck bool) { + // Ensure the dependencies are loaded, in parallel. + var fromPath string + if cycleCheck { + fromPath = info.Pkg.Path() + } + // TODO(adonovan): opt: make the caller do scanImports. + // Callers with a build.Package can skip it. + imp.importAll(fromPath, info.dir, scanImports(files), 0) + + if trace { + fmt.Fprintf(os.Stderr, "%s: start %q (%d)\n", + time.Since(imp.start), info.Pkg.Path(), len(files)) + } + + // Don't call checker.Files on Unsafe, even with zero files, + // because it would mutate the package, which is a global. + if info.Pkg == types.Unsafe { + if len(files) > 0 { + panic(`"unsafe" package contains unexpected files`) + } + } else { + // Ignore the returned (first) error since we + // already collect them all in the PackageInfo. + info.checker.Files(files) + info.Files = append(info.Files, files...) + } + + if imp.conf.AfterTypeCheck != nil { + imp.conf.AfterTypeCheck(info, files) + } + + if trace { + fmt.Fprintf(os.Stderr, "%s: stop %q\n", + time.Since(imp.start), info.Pkg.Path()) + } +} + +func (imp *importer) newPackageInfo(path, dir string) *PackageInfo { + var pkg *types.Package + if path == "unsafe" { + pkg = types.Unsafe + } else { + pkg = types.NewPackage(path, "") + } + info := &PackageInfo{ + Pkg: pkg, + Info: types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + }, + errorFunc: imp.conf.TypeChecker.Error, + dir: dir, + } + + // Copy the types.Config so we can vary it across PackageInfos. + tc := imp.conf.TypeChecker + tc.IgnoreFuncBodies = false + if f := imp.conf.TypeCheckFuncBodies; f != nil { + tc.IgnoreFuncBodies = !f(path) + } + tc.Importer = closure{imp, info} + tc.Error = info.appendError // appendError wraps the user's Error function + + info.checker = types.NewChecker(&tc, imp.conf.fset(), pkg, &info.Info) + imp.progMu.Lock() + imp.prog.AllPackages[pkg] = info + imp.progMu.Unlock() + return info +} + +type closure struct { + imp *importer + info *PackageInfo +} + +func (c closure) Import(to string) (*types.Package, error) { return c.imp.doImport(c.info, to) } diff --git a/vendor/golang.org/x/tools/go/loader/loader_test.go b/vendor/golang.org/x/tools/go/loader/loader_test.go new file mode 100644 index 0000000..02630eb --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/loader_test.go @@ -0,0 +1,816 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// No testdata on Android. + +// +build !android + +package loader_test + +import ( + "fmt" + "go/build" + "go/constant" + "go/types" + "path/filepath" + "reflect" + "sort" + "strings" + "sync" + "testing" + + "golang.org/x/tools/go/buildutil" + "golang.org/x/tools/go/loader" +) + +// TestFromArgs checks that conf.FromArgs populates conf correctly. +// It does no I/O. +func TestFromArgs(t *testing.T) { + type result struct { + Err string + Rest []string + ImportPkgs map[string]bool + CreatePkgs []loader.PkgSpec + } + for _, test := range []struct { + args []string + tests bool + want result + }{ + // Mix of existing and non-existent packages. + { + args: []string{"nosuchpkg", "errors"}, + want: result{ + ImportPkgs: map[string]bool{"errors": false, "nosuchpkg": false}, + }, + }, + // Same, with -test flag. + { + args: []string{"nosuchpkg", "errors"}, + tests: true, + want: result{ + ImportPkgs: map[string]bool{"errors": true, "nosuchpkg": true}, + }, + }, + // Surplus arguments. + { + args: []string{"fmt", "errors", "--", "surplus"}, + want: result{ + Rest: []string{"surplus"}, + ImportPkgs: map[string]bool{"errors": false, "fmt": false}, + }, + }, + // Ad hoc package specified as *.go files. + { + args: []string{"foo.go", "bar.go"}, + want: result{CreatePkgs: []loader.PkgSpec{{ + Filenames: []string{"foo.go", "bar.go"}, + }}}, + }, + // Mixture of *.go and import paths. + { + args: []string{"foo.go", "fmt"}, + want: result{ + Err: "named files must be .go files: fmt", + }, + }, + } { + var conf loader.Config + rest, err := conf.FromArgs(test.args, test.tests) + got := result{ + Rest: rest, + ImportPkgs: conf.ImportPkgs, + CreatePkgs: conf.CreatePkgs, + } + if err != nil { + got.Err = err.Error() + } + if !reflect.DeepEqual(got, test.want) { + t.Errorf("FromArgs(%q) = %+v, want %+v", test.args, got, test.want) + } + } +} + +func TestLoad_NoInitialPackages(t *testing.T) { + var conf loader.Config + + const wantErr = "no initial packages were loaded" + + prog, err := conf.Load() + if err == nil { + t.Errorf("Load succeeded unexpectedly, want %q", wantErr) + } else if err.Error() != wantErr { + t.Errorf("Load failed with wrong error %q, want %q", err, wantErr) + } + if prog != nil { + t.Errorf("Load unexpectedly returned a Program") + } +} + +func TestLoad_MissingInitialPackage(t *testing.T) { + var conf loader.Config + conf.Import("nosuchpkg") + conf.Import("errors") + + const wantErr = "couldn't load packages due to errors: nosuchpkg" + + prog, err := conf.Load() + if err == nil { + t.Errorf("Load succeeded unexpectedly, want %q", wantErr) + } else if err.Error() != wantErr { + t.Errorf("Load failed with wrong error %q, want %q", err, wantErr) + } + if prog != nil { + t.Errorf("Load unexpectedly returned a Program") + } +} + +func TestLoad_MissingInitialPackage_AllowErrors(t *testing.T) { + var conf loader.Config + conf.AllowErrors = true + conf.Import("nosuchpkg") + conf.ImportWithTests("errors") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed unexpectedly: %v", err) + } + if prog == nil { + t.Fatalf("Load returned a nil Program") + } + if got, want := created(prog), "errors_test"; got != want { + t.Errorf("Created = %s, want %s", got, want) + } + if got, want := imported(prog), "errors"; got != want { + t.Errorf("Imported = %s, want %s", got, want) + } +} + +func TestCreateUnnamedPackage(t *testing.T) { + var conf loader.Config + conf.CreateFromFilenames("") + prog, err := conf.Load() + if err != nil { + t.Fatalf("Load failed: %v", err) + } + if got, want := fmt.Sprint(prog.InitialPackages()), "[(unnamed)]"; got != want { + t.Errorf("InitialPackages = %s, want %s", got, want) + } +} + +func TestLoad_MissingFileInCreatedPackage(t *testing.T) { + var conf loader.Config + conf.CreateFromFilenames("", "missing.go") + + const wantErr = "couldn't load packages due to errors: (unnamed)" + + prog, err := conf.Load() + if prog != nil { + t.Errorf("Load unexpectedly returned a Program") + } + if err == nil { + t.Fatalf("Load succeeded unexpectedly, want %q", wantErr) + } + if err.Error() != wantErr { + t.Fatalf("Load failed with wrong error %q, want %q", err, wantErr) + } +} + +func TestLoad_MissingFileInCreatedPackage_AllowErrors(t *testing.T) { + conf := loader.Config{AllowErrors: true} + conf.CreateFromFilenames("", "missing.go") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed: %v", err) + } + if got, want := fmt.Sprint(prog.InitialPackages()), "[(unnamed)]"; got != want { + t.Fatalf("InitialPackages = %s, want %s", got, want) + } +} + +func TestLoad_ParseError(t *testing.T) { + var conf loader.Config + conf.CreateFromFilenames("badpkg", "testdata/badpkgdecl.go") + + const wantErr = "couldn't load packages due to errors: badpkg" + + prog, err := conf.Load() + if prog != nil { + t.Errorf("Load unexpectedly returned a Program") + } + if err == nil { + t.Fatalf("Load succeeded unexpectedly, want %q", wantErr) + } + if err.Error() != wantErr { + t.Fatalf("Load failed with wrong error %q, want %q", err, wantErr) + } +} + +func TestLoad_ParseError_AllowErrors(t *testing.T) { + var conf loader.Config + conf.AllowErrors = true + conf.CreateFromFilenames("badpkg", "testdata/badpkgdecl.go") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed unexpectedly: %v", err) + } + if prog == nil { + t.Fatalf("Load returned a nil Program") + } + if got, want := created(prog), "badpkg"; got != want { + t.Errorf("Created = %s, want %s", got, want) + } + + badpkg := prog.Created[0] + if len(badpkg.Files) != 1 { + t.Errorf("badpkg has %d files, want 1", len(badpkg.Files)) + } + wantErr := filepath.Join("testdata", "badpkgdecl.go") + ":1:34: expected 'package', found 'EOF'" + if !hasError(badpkg.Errors, wantErr) { + t.Errorf("badpkg.Errors = %v, want %s", badpkg.Errors, wantErr) + } +} + +func TestLoad_FromSource_Success(t *testing.T) { + var conf loader.Config + conf.CreateFromFilenames("P", "testdata/a.go", "testdata/b.go") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed unexpectedly: %v", err) + } + if prog == nil { + t.Fatalf("Load returned a nil Program") + } + if got, want := created(prog), "P"; got != want { + t.Errorf("Created = %s, want %s", got, want) + } +} + +func TestLoad_FromImports_Success(t *testing.T) { + var conf loader.Config + conf.ImportWithTests("fmt") + conf.ImportWithTests("errors") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed unexpectedly: %v", err) + } + if prog == nil { + t.Fatalf("Load returned a nil Program") + } + if got, want := created(prog), "errors_test fmt_test"; got != want { + t.Errorf("Created = %q, want %s", got, want) + } + if got, want := imported(prog), "errors fmt"; got != want { + t.Errorf("Imported = %s, want %s", got, want) + } + // Check set of transitive packages. + // There are >30 and the set may grow over time, so only check a few. + want := map[string]bool{ + "strings": true, + "time": true, + "runtime": true, + "testing": true, + "unicode": true, + } + for _, path := range all(prog) { + delete(want, path) + } + if len(want) > 0 { + t.Errorf("AllPackages is missing these keys: %q", keys(want)) + } +} + +func TestLoad_MissingIndirectImport(t *testing.T) { + pkgs := map[string]string{ + "a": `package a; import _ "b"`, + "b": `package b; import _ "c"`, + } + conf := loader.Config{Build: fakeContext(pkgs)} + conf.Import("a") + + const wantErr = "couldn't load packages due to errors: b" + + prog, err := conf.Load() + if err == nil { + t.Errorf("Load succeeded unexpectedly, want %q", wantErr) + } else if err.Error() != wantErr { + t.Errorf("Load failed with wrong error %q, want %q", err, wantErr) + } + if prog != nil { + t.Errorf("Load unexpectedly returned a Program") + } +} + +func TestLoad_BadDependency_AllowErrors(t *testing.T) { + for _, test := range []struct { + descr string + pkgs map[string]string + wantPkgs string + }{ + + { + descr: "missing dependency", + pkgs: map[string]string{ + "a": `package a; import _ "b"`, + "b": `package b; import _ "c"`, + }, + wantPkgs: "a b", + }, + { + descr: "bad package decl in dependency", + pkgs: map[string]string{ + "a": `package a; import _ "b"`, + "b": `package b; import _ "c"`, + "c": `package`, + }, + wantPkgs: "a b", + }, + { + descr: "parse error in dependency", + pkgs: map[string]string{ + "a": `package a; import _ "b"`, + "b": `package b; import _ "c"`, + "c": `package c; var x = `, + }, + wantPkgs: "a b c", + }, + } { + conf := loader.Config{ + AllowErrors: true, + Build: fakeContext(test.pkgs), + } + conf.Import("a") + + prog, err := conf.Load() + if err != nil { + t.Errorf("%s: Load failed unexpectedly: %v", test.descr, err) + } + if prog == nil { + t.Fatalf("%s: Load returned a nil Program", test.descr) + } + + if got, want := imported(prog), "a"; got != want { + t.Errorf("%s: Imported = %s, want %s", test.descr, got, want) + } + if got := all(prog); strings.Join(got, " ") != test.wantPkgs { + t.Errorf("%s: AllPackages = %s, want %s", test.descr, got, test.wantPkgs) + } + } +} + +func TestCwd(t *testing.T) { + ctxt := fakeContext(map[string]string{"one/two/three": `package three`}) + for _, test := range []struct { + cwd, arg, want string + }{ + {cwd: "/go/src/one", arg: "./two/three", want: "one/two/three"}, + {cwd: "/go/src/one", arg: "../one/two/three", want: "one/two/three"}, + {cwd: "/go/src/one", arg: "one/two/three", want: "one/two/three"}, + {cwd: "/go/src/one/two/three", arg: ".", want: "one/two/three"}, + {cwd: "/go/src/one", arg: "two/three", want: ""}, + } { + conf := loader.Config{ + Cwd: test.cwd, + Build: ctxt, + } + conf.Import(test.arg) + + var got string + prog, err := conf.Load() + if prog != nil { + got = imported(prog) + } + if got != test.want { + t.Errorf("Load(%s) from %s: Imported = %s, want %s", + test.arg, test.cwd, got, test.want) + if err != nil { + t.Errorf("Load failed: %v", err) + } + } + } +} + +func TestLoad_vendor(t *testing.T) { + pkgs := map[string]string{ + "a": `package a; import _ "x"`, + "a/vendor": ``, // mkdir a/vendor + "a/vendor/x": `package xa`, + "b": `package b; import _ "x"`, + "b/vendor": ``, // mkdir b/vendor + "b/vendor/x": `package xb`, + "c": `package c; import _ "x"`, + "x": `package xc`, + } + conf := loader.Config{Build: fakeContext(pkgs)} + conf.Import("a") + conf.Import("b") + conf.Import("c") + + prog, err := conf.Load() + if err != nil { + t.Fatal(err) + } + + // Check that a, b, and c see different versions of x. + for _, r := range "abc" { + name := string(r) + got := prog.Package(name).Pkg.Imports()[0] + want := "x" + name + if got.Name() != want { + t.Errorf("package %s import %q = %s, want %s", + name, "x", got.Name(), want) + } + } +} + +func TestVendorCwd(t *testing.T) { + // Test the interaction of cwd and vendor directories. + ctxt := fakeContext(map[string]string{ + "net": ``, // mkdir net + "net/http": `package http; import _ "hpack"`, + "vendor": ``, // mkdir vendor + "vendor/hpack": `package vendorhpack`, + "hpack": `package hpack`, + }) + for i, test := range []struct { + cwd, arg, want string + }{ + {cwd: "/go/src/net", arg: "http"}, // not found + {cwd: "/go/src/net", arg: "./http", want: "net/http vendor/hpack"}, + {cwd: "/go/src/net", arg: "hpack", want: "vendor/hpack"}, + {cwd: "/go/src/vendor", arg: "hpack", want: "vendor/hpack"}, + {cwd: "/go/src/vendor", arg: "./hpack", want: "vendor/hpack"}, + } { + conf := loader.Config{ + Cwd: test.cwd, + Build: ctxt, + } + conf.Import(test.arg) + + var got string + prog, err := conf.Load() + if prog != nil { + got = strings.Join(all(prog), " ") + } + if got != test.want { + t.Errorf("#%d: Load(%s) from %s: got %s, want %s", + i, test.arg, test.cwd, got, test.want) + if err != nil { + t.Errorf("Load failed: %v", err) + } + } + } +} + +func TestVendorCwdIssue16580(t *testing.T) { + // Regression test for Go issue 16580. + // Import decls in "created" packages were vendor-resolved + // w.r.t. cwd, not the parent directory of the package's files. + ctxt := fakeContext(map[string]string{ + "a": ``, // mkdir a + "a/vendor": ``, // mkdir a/vendor + "a/vendor/b": `package b; const X = true`, + "b": `package b; const X = false`, + }) + for _, test := range []struct { + filename, cwd string + want bool // expected value of b.X; depends on filename, not on cwd + }{ + {filename: "c.go", cwd: "/go/src", want: false}, + {filename: "c.go", cwd: "/go/src/a", want: false}, + {filename: "c.go", cwd: "/go/src/a/b", want: false}, + {filename: "c.go", cwd: "/go/src/a/vendor/b", want: false}, + + {filename: "/go/src/a/c.go", cwd: "/go/src", want: true}, + {filename: "/go/src/a/c.go", cwd: "/go/src/a", want: true}, + {filename: "/go/src/a/c.go", cwd: "/go/src/a/b", want: true}, + {filename: "/go/src/a/c.go", cwd: "/go/src/a/vendor/b", want: true}, + + {filename: "/go/src/c/c.go", cwd: "/go/src", want: false}, + {filename: "/go/src/c/c.go", cwd: "/go/src/a", want: false}, + {filename: "/go/src/c/c.go", cwd: "/go/src/a/b", want: false}, + {filename: "/go/src/c/c.go", cwd: "/go/src/a/vendor/b", want: false}, + } { + conf := loader.Config{ + Cwd: test.cwd, + Build: ctxt, + } + f, err := conf.ParseFile(test.filename, `package dummy; import "b"; const X = b.X`) + if err != nil { + t.Fatal(f) + } + conf.CreateFromFiles("dummy", f) + + prog, err := conf.Load() + if err != nil { + t.Errorf("%+v: Load failed: %v", test, err) + continue + } + + x := constant.BoolVal(prog.Created[0].Pkg.Scope().Lookup("X").(*types.Const).Val()) + if x != test.want { + t.Errorf("%+v: b.X = %t", test, x) + } + } + + // TODO(adonovan): also test imports within XTestGoFiles. +} + +// TODO(adonovan): more Load tests: +// +// failures: +// - to parse package decl of *_test.go files +// - to parse package decl of external *_test.go files +// - to parse whole of *_test.go files +// - to parse whole of external *_test.go files +// - to open a *.go file during import scanning +// - to import from binary + +// features: +// - InitialPackages +// - PackageCreated hook +// - TypeCheckFuncBodies hook + +func TestTransitivelyErrorFreeFlag(t *testing.T) { + // Create an minimal custom build.Context + // that fakes the following packages: + // + // a --> b --> c! c has an error + // \ d and e are transitively error-free. + // e --> d + // + // Each package [a-e] consists of one file, x.go. + pkgs := map[string]string{ + "a": `package a; import (_ "b"; _ "e")`, + "b": `package b; import _ "c"`, + "c": `package c; func f() { _ = int(false) }`, // type error within function body + "d": `package d;`, + "e": `package e; import _ "d"`, + } + conf := loader.Config{ + AllowErrors: true, + Build: fakeContext(pkgs), + } + conf.Import("a") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed: %s", err) + } + if prog == nil { + t.Fatalf("Load returned nil *Program") + } + + for pkg, info := range prog.AllPackages { + var wantErr, wantTEF bool + switch pkg.Path() { + case "a", "b": + case "c": + wantErr = true + case "d", "e": + wantTEF = true + default: + t.Errorf("unexpected package: %q", pkg.Path()) + continue + } + + if (info.Errors != nil) != wantErr { + if wantErr { + t.Errorf("Package %q.Error = nil, want error", pkg.Path()) + } else { + t.Errorf("Package %q has unexpected Errors: %v", + pkg.Path(), info.Errors) + } + } + + if info.TransitivelyErrorFree != wantTEF { + t.Errorf("Package %q.TransitivelyErrorFree=%t, want %t", + pkg.Path(), info.TransitivelyErrorFree, wantTEF) + } + } +} + +// Test that syntax (scan/parse), type, and loader errors are recorded +// (in PackageInfo.Errors) and reported (via Config.TypeChecker.Error). +func TestErrorReporting(t *testing.T) { + pkgs := map[string]string{ + "a": `package a; import (_ "b"; _ "c"); var x int = false`, + "b": `package b; 'syntax error!`, + } + conf := loader.Config{ + AllowErrors: true, + Build: fakeContext(pkgs), + } + var mu sync.Mutex + var allErrors []error + conf.TypeChecker.Error = func(err error) { + mu.Lock() + allErrors = append(allErrors, err) + mu.Unlock() + } + conf.Import("a") + + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed: %s", err) + } + if prog == nil { + t.Fatalf("Load returned nil *Program") + } + + // TODO(adonovan): test keys of ImportMap. + + // Check errors recorded in each PackageInfo. + for pkg, info := range prog.AllPackages { + switch pkg.Path() { + case "a": + if !hasError(info.Errors, "cannot convert false") { + t.Errorf("a.Errors = %v, want bool conversion (type) error", info.Errors) + } + if !hasError(info.Errors, "could not import c") { + t.Errorf("a.Errors = %v, want import (loader) error", info.Errors) + } + case "b": + if !hasError(info.Errors, "rune literal not terminated") { + t.Errorf("b.Errors = %v, want unterminated literal (syntax) error", info.Errors) + } + } + } + + // Check errors reported via error handler. + if !hasError(allErrors, "cannot convert false") || + !hasError(allErrors, "rune literal not terminated") || + !hasError(allErrors, "could not import c") { + t.Errorf("allErrors = %v, want syntax, type and loader errors", allErrors) + } +} + +func TestCycles(t *testing.T) { + for _, test := range []struct { + descr string + ctxt *build.Context + wantErr string + }{ + { + "self-cycle", + fakeContext(map[string]string{ + "main": `package main; import _ "selfcycle"`, + "selfcycle": `package selfcycle; import _ "selfcycle"`, + }), + `import cycle: selfcycle -> selfcycle`, + }, + { + "three-package cycle", + fakeContext(map[string]string{ + "main": `package main; import _ "a"`, + "a": `package a; import _ "b"`, + "b": `package b; import _ "c"`, + "c": `package c; import _ "a"`, + }), + `import cycle: c -> a -> b -> c`, + }, + { + "self-cycle in dependency of test file", + buildutil.FakeContext(map[string]map[string]string{ + "main": { + "main.go": `package main`, + "main_test.go": `package main; import _ "a"`, + }, + "a": { + "a.go": `package a; import _ "a"`, + }, + }), + `import cycle: a -> a`, + }, + // TODO(adonovan): fix: these fail + // { + // "two-package cycle in dependency of test file", + // buildutil.FakeContext(map[string]map[string]string{ + // "main": { + // "main.go": `package main`, + // "main_test.go": `package main; import _ "a"`, + // }, + // "a": { + // "a.go": `package a; import _ "main"`, + // }, + // }), + // `import cycle: main -> a -> main`, + // }, + // { + // "self-cycle in augmented package", + // buildutil.FakeContext(map[string]map[string]string{ + // "main": { + // "main.go": `package main`, + // "main_test.go": `package main; import _ "main"`, + // }, + // }), + // `import cycle: main -> main`, + // }, + } { + conf := loader.Config{ + AllowErrors: true, + Build: test.ctxt, + } + var mu sync.Mutex + var allErrors []error + conf.TypeChecker.Error = func(err error) { + mu.Lock() + allErrors = append(allErrors, err) + mu.Unlock() + } + conf.ImportWithTests("main") + + prog, err := conf.Load() + if err != nil { + t.Errorf("%s: Load failed: %s", test.descr, err) + } + if prog == nil { + t.Fatalf("%s: Load returned nil *Program", test.descr) + } + + if !hasError(allErrors, test.wantErr) { + t.Errorf("%s: Load() errors = %q, want %q", + test.descr, allErrors, test.wantErr) + } + } + + // TODO(adonovan): + // - Test that in a legal test cycle, none of the symbols + // defined by augmentation are visible via import. +} + +// ---- utilities ---- + +// Simplifying wrapper around buildutil.FakeContext for single-file packages. +func fakeContext(pkgs map[string]string) *build.Context { + pkgs2 := make(map[string]map[string]string) + for path, content := range pkgs { + pkgs2[path] = map[string]string{"x.go": content} + } + return buildutil.FakeContext(pkgs2) +} + +func hasError(errors []error, substr string) bool { + for _, err := range errors { + if strings.Contains(err.Error(), substr) { + return true + } + } + return false +} + +func keys(m map[string]bool) (keys []string) { + for key := range m { + keys = append(keys, key) + } + sort.Strings(keys) + return +} + +// Returns all loaded packages. +func all(prog *loader.Program) []string { + var pkgs []string + for _, info := range prog.AllPackages { + pkgs = append(pkgs, info.Pkg.Path()) + } + sort.Strings(pkgs) + return pkgs +} + +// Returns initially imported packages, as a string. +func imported(prog *loader.Program) string { + var pkgs []string + for _, info := range prog.Imported { + pkgs = append(pkgs, info.Pkg.Path()) + } + sort.Strings(pkgs) + return strings.Join(pkgs, " ") +} + +// Returns initially created packages, as a string. +func created(prog *loader.Program) string { + var pkgs []string + for _, info := range prog.Created { + pkgs = append(pkgs, info.Pkg.Path()) + } + return strings.Join(pkgs, " ") +} + +// Load package "io" twice in parallel. +// When run with -race, this is a regression test for Go issue 20718, in +// which the global "unsafe" package was modified concurrently. +func TestLoad1(t *testing.T) { loadIO(t) } +func TestLoad2(t *testing.T) { loadIO(t) } + +func loadIO(t *testing.T) { + t.Parallel() + conf := &loader.Config{ImportPkgs: map[string]bool{"io": false}} + if _, err := conf.Load(); err != nil { + t.Fatal(err) + } +} diff --git a/vendor/golang.org/x/tools/go/loader/stdlib_test.go b/vendor/golang.org/x/tools/go/loader/stdlib_test.go new file mode 100644 index 0000000..2cd066f --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/stdlib_test.go @@ -0,0 +1,201 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader_test + +// This file enumerates all packages beneath $GOROOT, loads them, plus +// their external tests if any, runs the type checker on them, and +// prints some summary information. + +import ( + "bytes" + "fmt" + "go/ast" + "go/build" + "go/token" + "go/types" + "io/ioutil" + "path/filepath" + "runtime" + "strings" + "testing" + "time" + + "golang.org/x/tools/go/buildutil" + "golang.org/x/tools/go/loader" +) + +func TestStdlib(t *testing.T) { + if runtime.GOOS == "android" { + t.Skipf("incomplete std lib on %s", runtime.GOOS) + } + if testing.Short() { + t.Skip("skipping in short mode; uses tons of memory (golang.org/issue/14113)") + } + + runtime.GC() + t0 := time.Now() + var memstats runtime.MemStats + runtime.ReadMemStats(&memstats) + alloc := memstats.Alloc + + // Load, parse and type-check the program. + ctxt := build.Default // copy + ctxt.GOPATH = "" // disable GOPATH + conf := loader.Config{Build: &ctxt} + for _, path := range buildutil.AllPackages(conf.Build) { + conf.ImportWithTests(path) + } + + prog, err := conf.Load() + if err != nil { + t.Fatalf("Load failed: %v", err) + } + + t1 := time.Now() + runtime.GC() + runtime.ReadMemStats(&memstats) + + numPkgs := len(prog.AllPackages) + if want := 205; numPkgs < want { + t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want) + } + + // Dump package members. + if false { + for pkg := range prog.AllPackages { + fmt.Printf("Package %s:\n", pkg.Path()) + scope := pkg.Scope() + qualifier := types.RelativeTo(pkg) + for _, name := range scope.Names() { + if ast.IsExported(name) { + fmt.Printf("\t%s\n", types.ObjectString(scope.Lookup(name), qualifier)) + } + } + fmt.Println() + } + } + + // Check that Test functions for io/ioutil, regexp and + // compress/bzip2 are all simultaneously present. + // (The apparent cycle formed when augmenting all three of + // these packages by their tests was the original motivation + // for reporting b/7114.) + // + // compress/bzip2.TestBitReader in bzip2_test.go imports io/ioutil + // io/ioutil.TestTempFile in tempfile_test.go imports regexp + // regexp.TestRE2Search in exec_test.go imports compress/bzip2 + for _, test := range []struct{ pkg, fn string }{ + {"io/ioutil", "TestTempFile"}, + {"regexp", "TestRE2Search"}, + {"compress/bzip2", "TestBitReader"}, + } { + info := prog.Imported[test.pkg] + if info == nil { + t.Errorf("failed to load package %q", test.pkg) + continue + } + obj, _ := info.Pkg.Scope().Lookup(test.fn).(*types.Func) + if obj == nil { + t.Errorf("package %q has no func %q", test.pkg, test.fn) + continue + } + } + + // Dump some statistics. + + // determine line count + var lineCount int + prog.Fset.Iterate(func(f *token.File) bool { + lineCount += f.LineCount() + return true + }) + + t.Log("GOMAXPROCS: ", runtime.GOMAXPROCS(0)) + t.Log("#Source lines: ", lineCount) + t.Log("Load/parse/typecheck: ", t1.Sub(t0)) + t.Log("#MB: ", int64(memstats.Alloc-alloc)/1000000) +} + +func TestCgoOption(t *testing.T) { + if testing.Short() { + t.Skip("skipping in short mode; uses tons of memory (golang.org/issue/14113)") + } + switch runtime.GOOS { + // On these systems, the net and os/user packages don't use cgo + // or the std library is incomplete (Android). + case "android", "plan9", "solaris", "windows": + t.Skipf("no cgo or incomplete std lib on %s", runtime.GOOS) + } + // In nocgo builds (e.g. linux-amd64-nocgo), + // there is no "runtime/cgo" package, + // so cgo-generated Go files will have a failing import. + if !build.Default.CgoEnabled { + return + } + // Test that we can load cgo-using packages with + // CGO_ENABLED=[01], which causes go/build to select pure + // Go/native implementations, respectively, based on build + // tags. + // + // Each entry specifies a package-level object and the generic + // file expected to define it when cgo is disabled. + // When cgo is enabled, the exact file is not specified (since + // it varies by platform), but must differ from the generic one. + // + // The test also loads the actual file to verify that the + // object is indeed defined at that location. + for _, test := range []struct { + pkg, name, genericFile string + }{ + {"net", "cgoLookupHost", "cgo_stub.go"}, + {"os/user", "current", "lookup_stubs.go"}, + } { + ctxt := build.Default + for _, ctxt.CgoEnabled = range []bool{false, true} { + conf := loader.Config{Build: &ctxt} + conf.Import(test.pkg) + prog, err := conf.Load() + if err != nil { + t.Errorf("Load failed: %v", err) + continue + } + info := prog.Imported[test.pkg] + if info == nil { + t.Errorf("package %s not found", test.pkg) + continue + } + obj := info.Pkg.Scope().Lookup(test.name) + if obj == nil { + t.Errorf("no object %s.%s", test.pkg, test.name) + continue + } + posn := prog.Fset.Position(obj.Pos()) + t.Logf("%s: %s (CgoEnabled=%t)", posn, obj, ctxt.CgoEnabled) + + gotFile := filepath.Base(posn.Filename) + filesMatch := gotFile == test.genericFile + + if ctxt.CgoEnabled && filesMatch { + t.Errorf("CGO_ENABLED=1: %s found in %s, want native file", + obj, gotFile) + } else if !ctxt.CgoEnabled && !filesMatch { + t.Errorf("CGO_ENABLED=0: %s found in %s, want %s", + obj, gotFile, test.genericFile) + } + + // Load the file and check the object is declared at the right place. + b, err := ioutil.ReadFile(posn.Filename) + if err != nil { + t.Errorf("can't read %s: %s", posn.Filename, err) + continue + } + line := string(bytes.Split(b, []byte("\n"))[posn.Line-1]) + ident := line[posn.Column-1:] + if !strings.HasPrefix(ident, test.name) { + t.Errorf("%s: %s not declared here (looking at %q)", posn, obj, ident) + } + } + } +} diff --git a/vendor/golang.org/x/tools/go/loader/testdata/a.go b/vendor/golang.org/x/tools/go/loader/testdata/a.go new file mode 100644 index 0000000..bae3955 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/testdata/a.go @@ -0,0 +1 @@ +package P diff --git a/vendor/golang.org/x/tools/go/loader/testdata/b.go b/vendor/golang.org/x/tools/go/loader/testdata/b.go new file mode 100644 index 0000000..bae3955 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/testdata/b.go @@ -0,0 +1 @@ +package P diff --git a/vendor/golang.org/x/tools/go/loader/testdata/badpkgdecl.go b/vendor/golang.org/x/tools/go/loader/testdata/badpkgdecl.go new file mode 100644 index 0000000..1e39359 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/testdata/badpkgdecl.go @@ -0,0 +1 @@ +// this file has no package decl diff --git a/vendor/golang.org/x/tools/go/loader/util.go b/vendor/golang.org/x/tools/go/loader/util.go new file mode 100644 index 0000000..7f38dd7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/util.go @@ -0,0 +1,124 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader + +import ( + "go/ast" + "go/build" + "go/parser" + "go/token" + "io" + "os" + "strconv" + "sync" + + "golang.org/x/tools/go/buildutil" +) + +// We use a counting semaphore to limit +// the number of parallel I/O calls per process. +var ioLimit = make(chan bool, 10) + +// parseFiles parses the Go source files within directory dir and +// returns the ASTs of the ones that could be at least partially parsed, +// along with a list of I/O and parse errors encountered. +// +// I/O is done via ctxt, which may specify a virtual file system. +// displayPath is used to transform the filenames attached to the ASTs. +// +func parseFiles(fset *token.FileSet, ctxt *build.Context, displayPath func(string) string, dir string, files []string, mode parser.Mode) ([]*ast.File, []error) { + if displayPath == nil { + displayPath = func(path string) string { return path } + } + var wg sync.WaitGroup + n := len(files) + parsed := make([]*ast.File, n) + errors := make([]error, n) + for i, file := range files { + if !buildutil.IsAbsPath(ctxt, file) { + file = buildutil.JoinPath(ctxt, dir, file) + } + wg.Add(1) + go func(i int, file string) { + ioLimit <- true // wait + defer func() { + wg.Done() + <-ioLimit // signal + }() + var rd io.ReadCloser + var err error + if ctxt.OpenFile != nil { + rd, err = ctxt.OpenFile(file) + } else { + rd, err = os.Open(file) + } + if err != nil { + errors[i] = err // open failed + return + } + + // ParseFile may return both an AST and an error. + parsed[i], errors[i] = parser.ParseFile(fset, displayPath(file), rd, mode) + rd.Close() + }(i, file) + } + wg.Wait() + + // Eliminate nils, preserving order. + var o int + for _, f := range parsed { + if f != nil { + parsed[o] = f + o++ + } + } + parsed = parsed[:o] + + o = 0 + for _, err := range errors { + if err != nil { + errors[o] = err + o++ + } + } + errors = errors[:o] + + return parsed, errors +} + +// scanImports returns the set of all import paths from all +// import specs in the specified files. +func scanImports(files []*ast.File) map[string]bool { + imports := make(map[string]bool) + for _, f := range files { + for _, decl := range f.Decls { + if decl, ok := decl.(*ast.GenDecl); ok && decl.Tok == token.IMPORT { + for _, spec := range decl.Specs { + spec := spec.(*ast.ImportSpec) + + // NB: do not assume the program is well-formed! + path, err := strconv.Unquote(spec.Path.Value) + if err != nil { + continue // quietly ignore the error + } + if path == "C" { + continue // skip pseudopackage + } + imports[path] = true + } + } + } + } + return imports +} + +// ---------- Internal helpers ---------- + +// TODO(adonovan): make this a method: func (*token.File) Contains(token.Pos) +func tokenFileContainsPos(f *token.File, pos token.Pos) bool { + p := int(pos) + base := f.Base() + return base <= p && p < base+f.Size() +} diff --git a/vendor/golang.org/x/tools/go/ssa/blockopt.go b/vendor/golang.org/x/tools/go/ssa/blockopt.go new file mode 100644 index 0000000..e79260a --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/blockopt.go @@ -0,0 +1,187 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// Simple block optimizations to simplify the control flow graph. + +// TODO(adonovan): opt: instead of creating several "unreachable" blocks +// per function in the Builder, reuse a single one (e.g. at Blocks[1]) +// to reduce garbage. + +import ( + "fmt" + "os" +) + +// If true, perform sanity checking and show progress at each +// successive iteration of optimizeBlocks. Very verbose. +const debugBlockOpt = false + +// markReachable sets Index=-1 for all blocks reachable from b. +func markReachable(b *BasicBlock) { + b.Index = -1 + for _, succ := range b.Succs { + if succ.Index == 0 { + markReachable(succ) + } + } +} + +// deleteUnreachableBlocks marks all reachable blocks of f and +// eliminates (nils) all others, including possibly cyclic subgraphs. +// +func deleteUnreachableBlocks(f *Function) { + const white, black = 0, -1 + // We borrow b.Index temporarily as the mark bit. + for _, b := range f.Blocks { + b.Index = white + } + markReachable(f.Blocks[0]) + if f.Recover != nil { + markReachable(f.Recover) + } + for i, b := range f.Blocks { + if b.Index == white { + for _, c := range b.Succs { + if c.Index == black { + c.removePred(b) // delete white->black edge + } + } + if debugBlockOpt { + fmt.Fprintln(os.Stderr, "unreachable", b) + } + f.Blocks[i] = nil // delete b + } + } + f.removeNilBlocks() +} + +// jumpThreading attempts to apply simple jump-threading to block b, +// in which a->b->c become a->c if b is just a Jump. +// The result is true if the optimization was applied. +// +func jumpThreading(f *Function, b *BasicBlock) bool { + if b.Index == 0 { + return false // don't apply to entry block + } + if b.Instrs == nil { + return false + } + if _, ok := b.Instrs[0].(*Jump); !ok { + return false // not just a jump + } + c := b.Succs[0] + if c == b { + return false // don't apply to degenerate jump-to-self. + } + if c.hasPhi() { + return false // not sound without more effort + } + for j, a := range b.Preds { + a.replaceSucc(b, c) + + // If a now has two edges to c, replace its degenerate If by Jump. + if len(a.Succs) == 2 && a.Succs[0] == c && a.Succs[1] == c { + jump := new(Jump) + jump.setBlock(a) + a.Instrs[len(a.Instrs)-1] = jump + a.Succs = a.Succs[:1] + c.removePred(b) + } else { + if j == 0 { + c.replacePred(b, a) + } else { + c.Preds = append(c.Preds, a) + } + } + + if debugBlockOpt { + fmt.Fprintln(os.Stderr, "jumpThreading", a, b, c) + } + } + f.Blocks[b.Index] = nil // delete b + return true +} + +// fuseBlocks attempts to apply the block fusion optimization to block +// a, in which a->b becomes ab if len(a.Succs)==len(b.Preds)==1. +// The result is true if the optimization was applied. +// +func fuseBlocks(f *Function, a *BasicBlock) bool { + if len(a.Succs) != 1 { + return false + } + b := a.Succs[0] + if len(b.Preds) != 1 { + return false + } + + // Degenerate &&/|| ops may result in a straight-line CFG + // containing φ-nodes. (Ideally we'd replace such them with + // their sole operand but that requires Referrers, built later.) + if b.hasPhi() { + return false // not sound without further effort + } + + // Eliminate jump at end of A, then copy all of B across. + a.Instrs = append(a.Instrs[:len(a.Instrs)-1], b.Instrs...) + for _, instr := range b.Instrs { + instr.setBlock(a) + } + + // A inherits B's successors + a.Succs = append(a.succs2[:0], b.Succs...) + + // Fix up Preds links of all successors of B. + for _, c := range b.Succs { + c.replacePred(b, a) + } + + if debugBlockOpt { + fmt.Fprintln(os.Stderr, "fuseBlocks", a, b) + } + + f.Blocks[b.Index] = nil // delete b + return true +} + +// optimizeBlocks() performs some simple block optimizations on a +// completed function: dead block elimination, block fusion, jump +// threading. +// +func optimizeBlocks(f *Function) { + deleteUnreachableBlocks(f) + + // Loop until no further progress. + changed := true + for changed { + changed = false + + if debugBlockOpt { + f.WriteTo(os.Stderr) + mustSanityCheck(f, nil) + } + + for _, b := range f.Blocks { + // f.Blocks will temporarily contain nils to indicate + // deleted blocks; we remove them at the end. + if b == nil { + continue + } + + // Fuse blocks. b->c becomes bc. + if fuseBlocks(f, b) { + changed = true + } + + // a->b->c becomes a->c if b contains only a Jump. + if jumpThreading(f, b) { + changed = true + continue // (b was disconnected) + } + } + } + f.removeNilBlocks() +} diff --git a/vendor/golang.org/x/tools/go/ssa/builder.go b/vendor/golang.org/x/tools/go/ssa/builder.go new file mode 100644 index 0000000..44abc5b --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/builder.go @@ -0,0 +1,2379 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the BUILD phase of SSA construction. +// +// SSA construction has two phases, CREATE and BUILD. In the CREATE phase +// (create.go), all packages are constructed and type-checked and +// definitions of all package members are created, method-sets are +// computed, and wrapper methods are synthesized. +// ssa.Packages are created in arbitrary order. +// +// In the BUILD phase (builder.go), the builder traverses the AST of +// each Go source function and generates SSA instructions for the +// function body. Initializer expressions for package-level variables +// are emitted to the package's init() function in the order specified +// by go/types.Info.InitOrder, then code for each function in the +// package is generated in lexical order. +// The BUILD phases for distinct packages are independent and are +// executed in parallel. +// +// TODO(adonovan): indeed, building functions is now embarrassingly parallel. +// Audit for concurrency then benchmark using more goroutines. +// +// The builder's and Program's indices (maps) are populated and +// mutated during the CREATE phase, but during the BUILD phase they +// remain constant. The sole exception is Prog.methodSets and its +// related maps, which are protected by a dedicated mutex. + +import ( + "fmt" + "go/ast" + exact "go/constant" + "go/token" + "go/types" + "os" + "sync" +) + +type opaqueType struct { + types.Type + name string +} + +func (t *opaqueType) String() string { return t.name } + +var ( + varOk = newVar("ok", tBool) + varIndex = newVar("index", tInt) + + // Type constants. + tBool = types.Typ[types.Bool] + tByte = types.Typ[types.Byte] + tInt = types.Typ[types.Int] + tInvalid = types.Typ[types.Invalid] + tString = types.Typ[types.String] + tUntypedNil = types.Typ[types.UntypedNil] + tRangeIter = &opaqueType{nil, "iter"} // the type of all "range" iterators + tEface = types.NewInterface(nil, nil).Complete() + + // SSA Value constants. + vZero = intConst(0) + vOne = intConst(1) + vTrue = NewConst(exact.MakeBool(true), tBool) +) + +// builder holds state associated with the package currently being built. +// Its methods contain all the logic for AST-to-SSA conversion. +type builder struct{} + +// cond emits to fn code to evaluate boolean condition e and jump +// to t or f depending on its value, performing various simplifications. +// +// Postcondition: fn.currentBlock is nil. +// +func (b *builder) cond(fn *Function, e ast.Expr, t, f *BasicBlock) { + switch e := e.(type) { + case *ast.ParenExpr: + b.cond(fn, e.X, t, f) + return + + case *ast.BinaryExpr: + switch e.Op { + case token.LAND: + ltrue := fn.newBasicBlock("cond.true") + b.cond(fn, e.X, ltrue, f) + fn.currentBlock = ltrue + b.cond(fn, e.Y, t, f) + return + + case token.LOR: + lfalse := fn.newBasicBlock("cond.false") + b.cond(fn, e.X, t, lfalse) + fn.currentBlock = lfalse + b.cond(fn, e.Y, t, f) + return + } + + case *ast.UnaryExpr: + if e.Op == token.NOT { + b.cond(fn, e.X, f, t) + return + } + } + + // A traditional compiler would simplify "if false" (etc) here + // but we do not, for better fidelity to the source code. + // + // The value of a constant condition may be platform-specific, + // and may cause blocks that are reachable in some configuration + // to be hidden from subsequent analyses such as bug-finding tools. + emitIf(fn, b.expr(fn, e), t, f) +} + +// logicalBinop emits code to fn to evaluate e, a &&- or +// ||-expression whose reified boolean value is wanted. +// The value is returned. +// +func (b *builder) logicalBinop(fn *Function, e *ast.BinaryExpr) Value { + rhs := fn.newBasicBlock("binop.rhs") + done := fn.newBasicBlock("binop.done") + + // T(e) = T(e.X) = T(e.Y) after untyped constants have been + // eliminated. + // TODO(adonovan): not true; MyBool==MyBool yields UntypedBool. + t := fn.Pkg.typeOf(e) + + var short Value // value of the short-circuit path + switch e.Op { + case token.LAND: + b.cond(fn, e.X, rhs, done) + short = NewConst(exact.MakeBool(false), t) + + case token.LOR: + b.cond(fn, e.X, done, rhs) + short = NewConst(exact.MakeBool(true), t) + } + + // Is rhs unreachable? + if rhs.Preds == nil { + // Simplify false&&y to false, true||y to true. + fn.currentBlock = done + return short + } + + // Is done unreachable? + if done.Preds == nil { + // Simplify true&&y (or false||y) to y. + fn.currentBlock = rhs + return b.expr(fn, e.Y) + } + + // All edges from e.X to done carry the short-circuit value. + var edges []Value + for range done.Preds { + edges = append(edges, short) + } + + // The edge from e.Y to done carries the value of e.Y. + fn.currentBlock = rhs + edges = append(edges, b.expr(fn, e.Y)) + emitJump(fn, done) + fn.currentBlock = done + + phi := &Phi{Edges: edges, Comment: e.Op.String()} + phi.pos = e.OpPos + phi.typ = t + return done.emit(phi) +} + +// exprN lowers a multi-result expression e to SSA form, emitting code +// to fn and returning a single Value whose type is a *types.Tuple. +// The caller must access the components via Extract. +// +// Multi-result expressions include CallExprs in a multi-value +// assignment or return statement, and "value,ok" uses of +// TypeAssertExpr, IndexExpr (when X is a map), and UnaryExpr (when Op +// is token.ARROW). +// +func (b *builder) exprN(fn *Function, e ast.Expr) Value { + typ := fn.Pkg.typeOf(e).(*types.Tuple) + switch e := e.(type) { + case *ast.ParenExpr: + return b.exprN(fn, e.X) + + case *ast.CallExpr: + // Currently, no built-in function nor type conversion + // has multiple results, so we can avoid some of the + // cases for single-valued CallExpr. + var c Call + b.setCall(fn, e, &c.Call) + c.typ = typ + return fn.emit(&c) + + case *ast.IndexExpr: + mapt := fn.Pkg.typeOf(e.X).Underlying().(*types.Map) + lookup := &Lookup{ + X: b.expr(fn, e.X), + Index: emitConv(fn, b.expr(fn, e.Index), mapt.Key()), + CommaOk: true, + } + lookup.setType(typ) + lookup.setPos(e.Lbrack) + return fn.emit(lookup) + + case *ast.TypeAssertExpr: + return emitTypeTest(fn, b.expr(fn, e.X), typ.At(0).Type(), e.Lparen) + + case *ast.UnaryExpr: // must be receive <- + unop := &UnOp{ + Op: token.ARROW, + X: b.expr(fn, e.X), + CommaOk: true, + } + unop.setType(typ) + unop.setPos(e.OpPos) + return fn.emit(unop) + } + panic(fmt.Sprintf("exprN(%T) in %s", e, fn)) +} + +// builtin emits to fn SSA instructions to implement a call to the +// built-in function obj with the specified arguments +// and return type. It returns the value defined by the result. +// +// The result is nil if no special handling was required; in this case +// the caller should treat this like an ordinary library function +// call. +// +func (b *builder) builtin(fn *Function, obj *types.Builtin, args []ast.Expr, typ types.Type, pos token.Pos) Value { + switch obj.Name() { + case "make": + switch typ.Underlying().(type) { + case *types.Slice: + n := b.expr(fn, args[1]) + m := n + if len(args) == 3 { + m = b.expr(fn, args[2]) + } + if m, ok := m.(*Const); ok { + // treat make([]T, n, m) as new([m]T)[:n] + cap := m.Int64() + at := types.NewArray(typ.Underlying().(*types.Slice).Elem(), cap) + alloc := emitNew(fn, at, pos) + alloc.Comment = "makeslice" + v := &Slice{ + X: alloc, + High: n, + } + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + } + v := &MakeSlice{ + Len: n, + Cap: m, + } + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + + case *types.Map: + var res Value + if len(args) == 2 { + res = b.expr(fn, args[1]) + } + v := &MakeMap{Reserve: res} + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + + case *types.Chan: + var sz Value = vZero + if len(args) == 2 { + sz = b.expr(fn, args[1]) + } + v := &MakeChan{Size: sz} + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + } + + case "new": + alloc := emitNew(fn, deref(typ), pos) + alloc.Comment = "new" + return alloc + + case "len", "cap": + // Special case: len or cap of an array or *array is + // based on the type, not the value which may be nil. + // We must still evaluate the value, though. (If it + // was side-effect free, the whole call would have + // been constant-folded.) + t := deref(fn.Pkg.typeOf(args[0])).Underlying() + if at, ok := t.(*types.Array); ok { + b.expr(fn, args[0]) // for effects only + return intConst(at.Len()) + } + // Otherwise treat as normal. + + case "panic": + fn.emit(&Panic{ + X: emitConv(fn, b.expr(fn, args[0]), tEface), + pos: pos, + }) + fn.currentBlock = fn.newBasicBlock("unreachable") + return vTrue // any non-nil Value will do + } + return nil // treat all others as a regular function call +} + +// addr lowers a single-result addressable expression e to SSA form, +// emitting code to fn and returning the location (an lvalue) defined +// by the expression. +// +// If escaping is true, addr marks the base variable of the +// addressable expression e as being a potentially escaping pointer +// value. For example, in this code: +// +// a := A{ +// b: [1]B{B{c: 1}} +// } +// return &a.b[0].c +// +// the application of & causes a.b[0].c to have its address taken, +// which means that ultimately the local variable a must be +// heap-allocated. This is a simple but very conservative escape +// analysis. +// +// Operations forming potentially escaping pointers include: +// - &x, including when implicit in method call or composite literals. +// - a[:] iff a is an array (not *array) +// - references to variables in lexically enclosing functions. +// +func (b *builder) addr(fn *Function, e ast.Expr, escaping bool) lvalue { + switch e := e.(type) { + case *ast.Ident: + if isBlankIdent(e) { + return blank{} + } + obj := fn.Pkg.objectOf(e) + v := fn.Prog.packageLevelValue(obj) // var (address) + if v == nil { + v = fn.lookup(obj, escaping) + } + return &address{addr: v, pos: e.Pos(), expr: e} + + case *ast.CompositeLit: + t := deref(fn.Pkg.typeOf(e)) + var v *Alloc + if escaping { + v = emitNew(fn, t, e.Lbrace) + } else { + v = fn.addLocal(t, e.Lbrace) + } + v.Comment = "complit" + var sb storebuf + b.compLit(fn, v, e, true, &sb) + sb.emit(fn) + return &address{addr: v, pos: e.Lbrace, expr: e} + + case *ast.ParenExpr: + return b.addr(fn, e.X, escaping) + + case *ast.SelectorExpr: + sel, ok := fn.Pkg.info.Selections[e] + if !ok { + // qualified identifier + return b.addr(fn, e.Sel, escaping) + } + if sel.Kind() != types.FieldVal { + panic(sel) + } + wantAddr := true + v := b.receiver(fn, e.X, wantAddr, escaping, sel) + last := len(sel.Index()) - 1 + return &address{ + addr: emitFieldSelection(fn, v, sel.Index()[last], true, e.Sel), + pos: e.Sel.Pos(), + expr: e.Sel, + } + + case *ast.IndexExpr: + var x Value + var et types.Type + switch t := fn.Pkg.typeOf(e.X).Underlying().(type) { + case *types.Array: + x = b.addr(fn, e.X, escaping).address(fn) + et = types.NewPointer(t.Elem()) + case *types.Pointer: // *array + x = b.expr(fn, e.X) + et = types.NewPointer(t.Elem().Underlying().(*types.Array).Elem()) + case *types.Slice: + x = b.expr(fn, e.X) + et = types.NewPointer(t.Elem()) + case *types.Map: + return &element{ + m: b.expr(fn, e.X), + k: emitConv(fn, b.expr(fn, e.Index), t.Key()), + t: t.Elem(), + pos: e.Lbrack, + } + default: + panic("unexpected container type in IndexExpr: " + t.String()) + } + v := &IndexAddr{ + X: x, + Index: emitConv(fn, b.expr(fn, e.Index), tInt), + } + v.setPos(e.Lbrack) + v.setType(et) + return &address{addr: fn.emit(v), pos: e.Lbrack, expr: e} + + case *ast.StarExpr: + return &address{addr: b.expr(fn, e.X), pos: e.Star, expr: e} + } + + panic(fmt.Sprintf("unexpected address expression: %T", e)) +} + +type store struct { + lhs lvalue + rhs Value +} + +type storebuf struct{ stores []store } + +func (sb *storebuf) store(lhs lvalue, rhs Value) { + sb.stores = append(sb.stores, store{lhs, rhs}) +} + +func (sb *storebuf) emit(fn *Function) { + for _, s := range sb.stores { + s.lhs.store(fn, s.rhs) + } +} + +// assign emits to fn code to initialize the lvalue loc with the value +// of expression e. If isZero is true, assign assumes that loc holds +// the zero value for its type. +// +// This is equivalent to loc.store(fn, b.expr(fn, e)), but may generate +// better code in some cases, e.g., for composite literals in an +// addressable location. +// +// If sb is not nil, assign generates code to evaluate expression e, but +// not to update loc. Instead, the necessary stores are appended to the +// storebuf sb so that they can be executed later. This allows correct +// in-place update of existing variables when the RHS is a composite +// literal that may reference parts of the LHS. +// +func (b *builder) assign(fn *Function, loc lvalue, e ast.Expr, isZero bool, sb *storebuf) { + // Can we initialize it in place? + if e, ok := unparen(e).(*ast.CompositeLit); ok { + // A CompositeLit never evaluates to a pointer, + // so if the type of the location is a pointer, + // an &-operation is implied. + if _, ok := loc.(blank); !ok { // avoid calling blank.typ() + if isPointer(loc.typ()) { + ptr := b.addr(fn, e, true).address(fn) + // copy address + if sb != nil { + sb.store(loc, ptr) + } else { + loc.store(fn, ptr) + } + return + } + } + + if _, ok := loc.(*address); ok { + if isInterface(loc.typ()) { + // e.g. var x interface{} = T{...} + // Can't in-place initialize an interface value. + // Fall back to copying. + } else { + // x = T{...} or x := T{...} + addr := loc.address(fn) + if sb != nil { + b.compLit(fn, addr, e, isZero, sb) + } else { + var sb storebuf + b.compLit(fn, addr, e, isZero, &sb) + sb.emit(fn) + } + + // Subtle: emit debug ref for aggregate types only; + // slice and map are handled by store ops in compLit. + switch loc.typ().Underlying().(type) { + case *types.Struct, *types.Array: + emitDebugRef(fn, e, addr, true) + } + + return + } + } + } + + // simple case: just copy + rhs := b.expr(fn, e) + if sb != nil { + sb.store(loc, rhs) + } else { + loc.store(fn, rhs) + } +} + +// expr lowers a single-result expression e to SSA form, emitting code +// to fn and returning the Value defined by the expression. +// +func (b *builder) expr(fn *Function, e ast.Expr) Value { + e = unparen(e) + + tv := fn.Pkg.info.Types[e] + + // Is expression a constant? + if tv.Value != nil { + return NewConst(tv.Value, tv.Type) + } + + var v Value + if tv.Addressable() { + // Prefer pointer arithmetic ({Index,Field}Addr) followed + // by Load over subelement extraction (e.g. Index, Field), + // to avoid large copies. + v = b.addr(fn, e, false).load(fn) + } else { + v = b.expr0(fn, e, tv) + } + if fn.debugInfo() { + emitDebugRef(fn, e, v, false) + } + return v +} + +func (b *builder) expr0(fn *Function, e ast.Expr, tv types.TypeAndValue) Value { + switch e := e.(type) { + case *ast.BasicLit: + panic("non-constant BasicLit") // unreachable + + case *ast.FuncLit: + fn2 := &Function{ + name: fmt.Sprintf("%s$%d", fn.Name(), 1+len(fn.AnonFuncs)), + Signature: fn.Pkg.typeOf(e.Type).Underlying().(*types.Signature), + pos: e.Type.Func, + parent: fn, + Pkg: fn.Pkg, + Prog: fn.Prog, + syntax: e, + } + fn.AnonFuncs = append(fn.AnonFuncs, fn2) + b.buildFunction(fn2) + if fn2.FreeVars == nil { + return fn2 + } + v := &MakeClosure{Fn: fn2} + v.setType(tv.Type) + for _, fv := range fn2.FreeVars { + v.Bindings = append(v.Bindings, fv.outer) + fv.outer = nil + } + return fn.emit(v) + + case *ast.TypeAssertExpr: // single-result form only + return emitTypeAssert(fn, b.expr(fn, e.X), tv.Type, e.Lparen) + + case *ast.CallExpr: + if fn.Pkg.info.Types[e.Fun].IsType() { + // Explicit type conversion, e.g. string(x) or big.Int(x) + x := b.expr(fn, e.Args[0]) + y := emitConv(fn, x, tv.Type) + if y != x { + switch y := y.(type) { + case *Convert: + y.pos = e.Lparen + case *ChangeType: + y.pos = e.Lparen + case *MakeInterface: + y.pos = e.Lparen + } + } + return y + } + // Call to "intrinsic" built-ins, e.g. new, make, panic. + if id, ok := unparen(e.Fun).(*ast.Ident); ok { + if obj, ok := fn.Pkg.info.Uses[id].(*types.Builtin); ok { + if v := b.builtin(fn, obj, e.Args, tv.Type, e.Lparen); v != nil { + return v + } + } + } + // Regular function call. + var v Call + b.setCall(fn, e, &v.Call) + v.setType(tv.Type) + return fn.emit(&v) + + case *ast.UnaryExpr: + switch e.Op { + case token.AND: // &X --- potentially escaping. + addr := b.addr(fn, e.X, true) + if _, ok := unparen(e.X).(*ast.StarExpr); ok { + // &*p must panic if p is nil (http://golang.org/s/go12nil). + // For simplicity, we'll just (suboptimally) rely + // on the side effects of a load. + // TODO(adonovan): emit dedicated nilcheck. + addr.load(fn) + } + return addr.address(fn) + case token.ADD: + return b.expr(fn, e.X) + case token.NOT, token.ARROW, token.SUB, token.XOR: // ! <- - ^ + v := &UnOp{ + Op: e.Op, + X: b.expr(fn, e.X), + } + v.setPos(e.OpPos) + v.setType(tv.Type) + return fn.emit(v) + default: + panic(e.Op) + } + + case *ast.BinaryExpr: + switch e.Op { + case token.LAND, token.LOR: + return b.logicalBinop(fn, e) + case token.SHL, token.SHR: + fallthrough + case token.ADD, token.SUB, token.MUL, token.QUO, token.REM, token.AND, token.OR, token.XOR, token.AND_NOT: + return emitArith(fn, e.Op, b.expr(fn, e.X), b.expr(fn, e.Y), tv.Type, e.OpPos) + + case token.EQL, token.NEQ, token.GTR, token.LSS, token.LEQ, token.GEQ: + cmp := emitCompare(fn, e.Op, b.expr(fn, e.X), b.expr(fn, e.Y), e.OpPos) + // The type of x==y may be UntypedBool. + return emitConv(fn, cmp, DefaultType(tv.Type)) + default: + panic("illegal op in BinaryExpr: " + e.Op.String()) + } + + case *ast.SliceExpr: + var low, high, max Value + var x Value + switch fn.Pkg.typeOf(e.X).Underlying().(type) { + case *types.Array: + // Potentially escaping. + x = b.addr(fn, e.X, true).address(fn) + case *types.Basic, *types.Slice, *types.Pointer: // *array + x = b.expr(fn, e.X) + default: + panic("unreachable") + } + if e.High != nil { + high = b.expr(fn, e.High) + } + if e.Low != nil { + low = b.expr(fn, e.Low) + } + if e.Slice3 { + max = b.expr(fn, e.Max) + } + v := &Slice{ + X: x, + Low: low, + High: high, + Max: max, + } + v.setPos(e.Lbrack) + v.setType(tv.Type) + return fn.emit(v) + + case *ast.Ident: + obj := fn.Pkg.info.Uses[e] + // Universal built-in or nil? + switch obj := obj.(type) { + case *types.Builtin: + return &Builtin{name: obj.Name(), sig: tv.Type.(*types.Signature)} + case *types.Nil: + return nilConst(tv.Type) + } + // Package-level func or var? + if v := fn.Prog.packageLevelValue(obj); v != nil { + if _, ok := obj.(*types.Var); ok { + return emitLoad(fn, v) // var (address) + } + return v // (func) + } + // Local var. + return emitLoad(fn, fn.lookup(obj, false)) // var (address) + + case *ast.SelectorExpr: + sel, ok := fn.Pkg.info.Selections[e] + if !ok { + // qualified identifier + return b.expr(fn, e.Sel) + } + switch sel.Kind() { + case types.MethodExpr: + // (*T).f or T.f, the method f from the method-set of type T. + // The result is a "thunk". + return emitConv(fn, makeThunk(fn.Prog, sel), tv.Type) + + case types.MethodVal: + // e.f where e is an expression and f is a method. + // The result is a "bound". + obj := sel.Obj().(*types.Func) + rt := recvType(obj) + wantAddr := isPointer(rt) + escaping := true + v := b.receiver(fn, e.X, wantAddr, escaping, sel) + if isInterface(rt) { + // If v has interface type I, + // we must emit a check that v is non-nil. + // We use: typeassert v.(I). + emitTypeAssert(fn, v, rt, token.NoPos) + } + c := &MakeClosure{ + Fn: makeBound(fn.Prog, obj), + Bindings: []Value{v}, + } + c.setPos(e.Sel.Pos()) + c.setType(tv.Type) + return fn.emit(c) + + case types.FieldVal: + indices := sel.Index() + last := len(indices) - 1 + v := b.expr(fn, e.X) + v = emitImplicitSelections(fn, v, indices[:last]) + v = emitFieldSelection(fn, v, indices[last], false, e.Sel) + return v + } + + panic("unexpected expression-relative selector") + + case *ast.IndexExpr: + switch t := fn.Pkg.typeOf(e.X).Underlying().(type) { + case *types.Array: + // Non-addressable array (in a register). + v := &Index{ + X: b.expr(fn, e.X), + Index: emitConv(fn, b.expr(fn, e.Index), tInt), + } + v.setPos(e.Lbrack) + v.setType(t.Elem()) + return fn.emit(v) + + case *types.Map: + // Maps are not addressable. + mapt := fn.Pkg.typeOf(e.X).Underlying().(*types.Map) + v := &Lookup{ + X: b.expr(fn, e.X), + Index: emitConv(fn, b.expr(fn, e.Index), mapt.Key()), + } + v.setPos(e.Lbrack) + v.setType(mapt.Elem()) + return fn.emit(v) + + case *types.Basic: // => string + // Strings are not addressable. + v := &Lookup{ + X: b.expr(fn, e.X), + Index: b.expr(fn, e.Index), + } + v.setPos(e.Lbrack) + v.setType(tByte) + return fn.emit(v) + + case *types.Slice, *types.Pointer: // *array + // Addressable slice/array; use IndexAddr and Load. + return b.addr(fn, e, false).load(fn) + + default: + panic("unexpected container type in IndexExpr: " + t.String()) + } + + case *ast.CompositeLit, *ast.StarExpr: + // Addressable types (lvalues) + return b.addr(fn, e, false).load(fn) + } + + panic(fmt.Sprintf("unexpected expr: %T", e)) +} + +// stmtList emits to fn code for all statements in list. +func (b *builder) stmtList(fn *Function, list []ast.Stmt) { + for _, s := range list { + b.stmt(fn, s) + } +} + +// receiver emits to fn code for expression e in the "receiver" +// position of selection e.f (where f may be a field or a method) and +// returns the effective receiver after applying the implicit field +// selections of sel. +// +// wantAddr requests that the result is an an address. If +// !sel.Indirect(), this may require that e be built in addr() mode; it +// must thus be addressable. +// +// escaping is defined as per builder.addr(). +// +func (b *builder) receiver(fn *Function, e ast.Expr, wantAddr, escaping bool, sel *types.Selection) Value { + var v Value + if wantAddr && !sel.Indirect() && !isPointer(fn.Pkg.typeOf(e)) { + v = b.addr(fn, e, escaping).address(fn) + } else { + v = b.expr(fn, e) + } + + last := len(sel.Index()) - 1 + v = emitImplicitSelections(fn, v, sel.Index()[:last]) + if !wantAddr && isPointer(v.Type()) { + v = emitLoad(fn, v) + } + return v +} + +// setCallFunc populates the function parts of a CallCommon structure +// (Func, Method, Recv, Args[0]) based on the kind of invocation +// occurring in e. +// +func (b *builder) setCallFunc(fn *Function, e *ast.CallExpr, c *CallCommon) { + c.pos = e.Lparen + + // Is this a method call? + if selector, ok := unparen(e.Fun).(*ast.SelectorExpr); ok { + sel, ok := fn.Pkg.info.Selections[selector] + if ok && sel.Kind() == types.MethodVal { + obj := sel.Obj().(*types.Func) + recv := recvType(obj) + wantAddr := isPointer(recv) + escaping := true + v := b.receiver(fn, selector.X, wantAddr, escaping, sel) + if isInterface(recv) { + // Invoke-mode call. + c.Value = v + c.Method = obj + } else { + // "Call"-mode call. + c.Value = fn.Prog.declaredFunc(obj) + c.Args = append(c.Args, v) + } + return + } + + // sel.Kind()==MethodExpr indicates T.f() or (*T).f(): + // a statically dispatched call to the method f in the + // method-set of T or *T. T may be an interface. + // + // e.Fun would evaluate to a concrete method, interface + // wrapper function, or promotion wrapper. + // + // For now, we evaluate it in the usual way. + // + // TODO(adonovan): opt: inline expr() here, to make the + // call static and to avoid generation of wrappers. + // It's somewhat tricky as it may consume the first + // actual parameter if the call is "invoke" mode. + // + // Examples: + // type T struct{}; func (T) f() {} // "call" mode + // type T interface { f() } // "invoke" mode + // + // type S struct{ T } + // + // var s S + // S.f(s) + // (*S).f(&s) + // + // Suggested approach: + // - consume the first actual parameter expression + // and build it with b.expr(). + // - apply implicit field selections. + // - use MethodVal logic to populate fields of c. + } + + // Evaluate the function operand in the usual way. + c.Value = b.expr(fn, e.Fun) +} + +// emitCallArgs emits to f code for the actual parameters of call e to +// a (possibly built-in) function of effective type sig. +// The argument values are appended to args, which is then returned. +// +func (b *builder) emitCallArgs(fn *Function, sig *types.Signature, e *ast.CallExpr, args []Value) []Value { + // f(x, y, z...): pass slice z straight through. + if e.Ellipsis != 0 { + for i, arg := range e.Args { + v := emitConv(fn, b.expr(fn, arg), sig.Params().At(i).Type()) + args = append(args, v) + } + return args + } + + offset := len(args) // 1 if call has receiver, 0 otherwise + + // Evaluate actual parameter expressions. + // + // If this is a chained call of the form f(g()) where g has + // multiple return values (MRV), they are flattened out into + // args; a suffix of them may end up in a varargs slice. + for _, arg := range e.Args { + v := b.expr(fn, arg) + if ttuple, ok := v.Type().(*types.Tuple); ok { // MRV chain + for i, n := 0, ttuple.Len(); i < n; i++ { + args = append(args, emitExtract(fn, v, i)) + } + } else { + args = append(args, v) + } + } + + // Actual->formal assignability conversions for normal parameters. + np := sig.Params().Len() // number of normal parameters + if sig.Variadic() { + np-- + } + for i := 0; i < np; i++ { + args[offset+i] = emitConv(fn, args[offset+i], sig.Params().At(i).Type()) + } + + // Actual->formal assignability conversions for variadic parameter, + // and construction of slice. + if sig.Variadic() { + varargs := args[offset+np:] + st := sig.Params().At(np).Type().(*types.Slice) + vt := st.Elem() + if len(varargs) == 0 { + args = append(args, nilConst(st)) + } else { + // Replace a suffix of args with a slice containing it. + at := types.NewArray(vt, int64(len(varargs))) + a := emitNew(fn, at, token.NoPos) + a.setPos(e.Rparen) + a.Comment = "varargs" + for i, arg := range varargs { + iaddr := &IndexAddr{ + X: a, + Index: intConst(int64(i)), + } + iaddr.setType(types.NewPointer(vt)) + fn.emit(iaddr) + emitStore(fn, iaddr, arg, arg.Pos()) + } + s := &Slice{X: a} + s.setType(st) + args[offset+np] = fn.emit(s) + args = args[:offset+np+1] + } + } + return args +} + +// setCall emits to fn code to evaluate all the parameters of a function +// call e, and populates *c with those values. +// +func (b *builder) setCall(fn *Function, e *ast.CallExpr, c *CallCommon) { + // First deal with the f(...) part and optional receiver. + b.setCallFunc(fn, e, c) + + // Then append the other actual parameters. + sig, _ := fn.Pkg.typeOf(e.Fun).Underlying().(*types.Signature) + if sig == nil { + panic(fmt.Sprintf("no signature for call of %s", e.Fun)) + } + c.Args = b.emitCallArgs(fn, sig, e, c.Args) +} + +// assignOp emits to fn code to perform loc += incr or loc -= incr. +func (b *builder) assignOp(fn *Function, loc lvalue, incr Value, op token.Token) { + oldv := loc.load(fn) + loc.store(fn, emitArith(fn, op, oldv, emitConv(fn, incr, oldv.Type()), loc.typ(), token.NoPos)) +} + +// localValueSpec emits to fn code to define all of the vars in the +// function-local ValueSpec, spec. +// +func (b *builder) localValueSpec(fn *Function, spec *ast.ValueSpec) { + switch { + case len(spec.Values) == len(spec.Names): + // e.g. var x, y = 0, 1 + // 1:1 assignment + for i, id := range spec.Names { + if !isBlankIdent(id) { + fn.addLocalForIdent(id) + } + lval := b.addr(fn, id, false) // non-escaping + b.assign(fn, lval, spec.Values[i], true, nil) + } + + case len(spec.Values) == 0: + // e.g. var x, y int + // Locals are implicitly zero-initialized. + for _, id := range spec.Names { + if !isBlankIdent(id) { + lhs := fn.addLocalForIdent(id) + if fn.debugInfo() { + emitDebugRef(fn, id, lhs, true) + } + } + } + + default: + // e.g. var x, y = pos() + tuple := b.exprN(fn, spec.Values[0]) + for i, id := range spec.Names { + if !isBlankIdent(id) { + fn.addLocalForIdent(id) + lhs := b.addr(fn, id, false) // non-escaping + lhs.store(fn, emitExtract(fn, tuple, i)) + } + } + } +} + +// assignStmt emits code to fn for a parallel assignment of rhss to lhss. +// isDef is true if this is a short variable declaration (:=). +// +// Note the similarity with localValueSpec. +// +func (b *builder) assignStmt(fn *Function, lhss, rhss []ast.Expr, isDef bool) { + // Side effects of all LHSs and RHSs must occur in left-to-right order. + lvals := make([]lvalue, len(lhss)) + isZero := make([]bool, len(lhss)) + for i, lhs := range lhss { + var lval lvalue = blank{} + if !isBlankIdent(lhs) { + if isDef { + if obj := fn.Pkg.info.Defs[lhs.(*ast.Ident)]; obj != nil { + fn.addNamedLocal(obj) + isZero[i] = true + } + } + lval = b.addr(fn, lhs, false) // non-escaping + } + lvals[i] = lval + } + if len(lhss) == len(rhss) { + // Simple assignment: x = f() (!isDef) + // Parallel assignment: x, y = f(), g() (!isDef) + // or short var decl: x, y := f(), g() (isDef) + // + // In all cases, the RHSs may refer to the LHSs, + // so we need a storebuf. + var sb storebuf + for i := range rhss { + b.assign(fn, lvals[i], rhss[i], isZero[i], &sb) + } + sb.emit(fn) + } else { + // e.g. x, y = pos() + tuple := b.exprN(fn, rhss[0]) + emitDebugRef(fn, rhss[0], tuple, false) + for i, lval := range lvals { + lval.store(fn, emitExtract(fn, tuple, i)) + } + } +} + +// arrayLen returns the length of the array whose composite literal elements are elts. +func (b *builder) arrayLen(fn *Function, elts []ast.Expr) int64 { + var max int64 = -1 + var i int64 = -1 + for _, e := range elts { + if kv, ok := e.(*ast.KeyValueExpr); ok { + i = b.expr(fn, kv.Key).(*Const).Int64() + } else { + i++ + } + if i > max { + max = i + } + } + return max + 1 +} + +// compLit emits to fn code to initialize a composite literal e at +// address addr with type typ. +// +// Nested composite literals are recursively initialized in place +// where possible. If isZero is true, compLit assumes that addr +// holds the zero value for typ. +// +// Because the elements of a composite literal may refer to the +// variables being updated, as in the second line below, +// x := T{a: 1} +// x = T{a: x.a} +// all the reads must occur before all the writes. Thus all stores to +// loc are emitted to the storebuf sb for later execution. +// +// A CompositeLit may have pointer type only in the recursive (nested) +// case when the type name is implicit. e.g. in []*T{{}}, the inner +// literal has type *T behaves like &T{}. +// In that case, addr must hold a T, not a *T. +// +func (b *builder) compLit(fn *Function, addr Value, e *ast.CompositeLit, isZero bool, sb *storebuf) { + typ := deref(fn.Pkg.typeOf(e)) + switch t := typ.Underlying().(type) { + case *types.Struct: + if !isZero && len(e.Elts) != t.NumFields() { + // memclear + sb.store(&address{addr, e.Lbrace, nil}, + zeroValue(fn, deref(addr.Type()))) + isZero = true + } + for i, e := range e.Elts { + fieldIndex := i + pos := e.Pos() + if kv, ok := e.(*ast.KeyValueExpr); ok { + fname := kv.Key.(*ast.Ident).Name + for i, n := 0, t.NumFields(); i < n; i++ { + sf := t.Field(i) + if sf.Name() == fname { + fieldIndex = i + pos = kv.Colon + e = kv.Value + break + } + } + } + sf := t.Field(fieldIndex) + faddr := &FieldAddr{ + X: addr, + Field: fieldIndex, + } + faddr.setType(types.NewPointer(sf.Type())) + fn.emit(faddr) + b.assign(fn, &address{addr: faddr, pos: pos, expr: e}, e, isZero, sb) + } + + case *types.Array, *types.Slice: + var at *types.Array + var array Value + switch t := t.(type) { + case *types.Slice: + at = types.NewArray(t.Elem(), b.arrayLen(fn, e.Elts)) + alloc := emitNew(fn, at, e.Lbrace) + alloc.Comment = "slicelit" + array = alloc + case *types.Array: + at = t + array = addr + + if !isZero && int64(len(e.Elts)) != at.Len() { + // memclear + sb.store(&address{array, e.Lbrace, nil}, + zeroValue(fn, deref(array.Type()))) + } + } + + var idx *Const + for _, e := range e.Elts { + pos := e.Pos() + if kv, ok := e.(*ast.KeyValueExpr); ok { + idx = b.expr(fn, kv.Key).(*Const) + pos = kv.Colon + e = kv.Value + } else { + var idxval int64 + if idx != nil { + idxval = idx.Int64() + 1 + } + idx = intConst(idxval) + } + iaddr := &IndexAddr{ + X: array, + Index: idx, + } + iaddr.setType(types.NewPointer(at.Elem())) + fn.emit(iaddr) + if t != at { // slice + // backing array is unaliased => storebuf not needed. + b.assign(fn, &address{addr: iaddr, pos: pos, expr: e}, e, true, nil) + } else { + b.assign(fn, &address{addr: iaddr, pos: pos, expr: e}, e, true, sb) + } + } + + if t != at { // slice + s := &Slice{X: array} + s.setPos(e.Lbrace) + s.setType(typ) + sb.store(&address{addr: addr, pos: e.Lbrace, expr: e}, fn.emit(s)) + } + + case *types.Map: + m := &MakeMap{Reserve: intConst(int64(len(e.Elts)))} + m.setPos(e.Lbrace) + m.setType(typ) + fn.emit(m) + for _, e := range e.Elts { + e := e.(*ast.KeyValueExpr) + + // If a key expression in a map literal is itself a + // composite literal, the type may be omitted. + // For example: + // map[*struct{}]bool{{}: true} + // An &-operation may be implied: + // map[*struct{}]bool{&struct{}{}: true} + var key Value + if _, ok := unparen(e.Key).(*ast.CompositeLit); ok && isPointer(t.Key()) { + // A CompositeLit never evaluates to a pointer, + // so if the type of the location is a pointer, + // an &-operation is implied. + key = b.addr(fn, e.Key, true).address(fn) + } else { + key = b.expr(fn, e.Key) + } + + loc := element{ + m: m, + k: emitConv(fn, key, t.Key()), + t: t.Elem(), + pos: e.Colon, + } + + // We call assign() only because it takes care + // of any &-operation required in the recursive + // case, e.g., + // map[int]*struct{}{0: {}} implies &struct{}{}. + // In-place update is of course impossible, + // and no storebuf is needed. + b.assign(fn, &loc, e.Value, true, nil) + } + sb.store(&address{addr: addr, pos: e.Lbrace, expr: e}, m) + + default: + panic("unexpected CompositeLit type: " + t.String()) + } +} + +// switchStmt emits to fn code for the switch statement s, optionally +// labelled by label. +// +func (b *builder) switchStmt(fn *Function, s *ast.SwitchStmt, label *lblock) { + // We treat SwitchStmt like a sequential if-else chain. + // Multiway dispatch can be recovered later by ssautil.Switches() + // to those cases that are free of side effects. + if s.Init != nil { + b.stmt(fn, s.Init) + } + var tag Value = vTrue + if s.Tag != nil { + tag = b.expr(fn, s.Tag) + } + done := fn.newBasicBlock("switch.done") + if label != nil { + label._break = done + } + // We pull the default case (if present) down to the end. + // But each fallthrough label must point to the next + // body block in source order, so we preallocate a + // body block (fallthru) for the next case. + // Unfortunately this makes for a confusing block order. + var dfltBody *[]ast.Stmt + var dfltFallthrough *BasicBlock + var fallthru, dfltBlock *BasicBlock + ncases := len(s.Body.List) + for i, clause := range s.Body.List { + body := fallthru + if body == nil { + body = fn.newBasicBlock("switch.body") // first case only + } + + // Preallocate body block for the next case. + fallthru = done + if i+1 < ncases { + fallthru = fn.newBasicBlock("switch.body") + } + + cc := clause.(*ast.CaseClause) + if cc.List == nil { + // Default case. + dfltBody = &cc.Body + dfltFallthrough = fallthru + dfltBlock = body + continue + } + + var nextCond *BasicBlock + for _, cond := range cc.List { + nextCond = fn.newBasicBlock("switch.next") + // TODO(adonovan): opt: when tag==vTrue, we'd + // get better code if we use b.cond(cond) + // instead of BinOp(EQL, tag, b.expr(cond)) + // followed by If. Don't forget conversions + // though. + cond := emitCompare(fn, token.EQL, tag, b.expr(fn, cond), token.NoPos) + emitIf(fn, cond, body, nextCond) + fn.currentBlock = nextCond + } + fn.currentBlock = body + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _fallthrough: fallthru, + } + b.stmtList(fn, cc.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) + fn.currentBlock = nextCond + } + if dfltBlock != nil { + emitJump(fn, dfltBlock) + fn.currentBlock = dfltBlock + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _fallthrough: dfltFallthrough, + } + b.stmtList(fn, *dfltBody) + fn.targets = fn.targets.tail + } + emitJump(fn, done) + fn.currentBlock = done +} + +// typeSwitchStmt emits to fn code for the type switch statement s, optionally +// labelled by label. +// +func (b *builder) typeSwitchStmt(fn *Function, s *ast.TypeSwitchStmt, label *lblock) { + // We treat TypeSwitchStmt like a sequential if-else chain. + // Multiway dispatch can be recovered later by ssautil.Switches(). + + // Typeswitch lowering: + // + // var x X + // switch y := x.(type) { + // case T1, T2: S1 // >1 (y := x) + // case nil: SN // nil (y := x) + // default: SD // 0 types (y := x) + // case T3: S3 // 1 type (y := x.(T3)) + // } + // + // ...s.Init... + // x := eval x + // .caseT1: + // t1, ok1 := typeswitch,ok x <T1> + // if ok1 then goto S1 else goto .caseT2 + // .caseT2: + // t2, ok2 := typeswitch,ok x <T2> + // if ok2 then goto S1 else goto .caseNil + // .S1: + // y := x + // ...S1... + // goto done + // .caseNil: + // if t2, ok2 := typeswitch,ok x <T2> + // if x == nil then goto SN else goto .caseT3 + // .SN: + // y := x + // ...SN... + // goto done + // .caseT3: + // t3, ok3 := typeswitch,ok x <T3> + // if ok3 then goto S3 else goto default + // .S3: + // y := t3 + // ...S3... + // goto done + // .default: + // y := x + // ...SD... + // goto done + // .done: + + if s.Init != nil { + b.stmt(fn, s.Init) + } + + var x Value + switch ass := s.Assign.(type) { + case *ast.ExprStmt: // x.(type) + x = b.expr(fn, unparen(ass.X).(*ast.TypeAssertExpr).X) + case *ast.AssignStmt: // y := x.(type) + x = b.expr(fn, unparen(ass.Rhs[0]).(*ast.TypeAssertExpr).X) + } + + done := fn.newBasicBlock("typeswitch.done") + if label != nil { + label._break = done + } + var default_ *ast.CaseClause + for _, clause := range s.Body.List { + cc := clause.(*ast.CaseClause) + if cc.List == nil { + default_ = cc + continue + } + body := fn.newBasicBlock("typeswitch.body") + var next *BasicBlock + var casetype types.Type + var ti Value // ti, ok := typeassert,ok x <Ti> + for _, cond := range cc.List { + next = fn.newBasicBlock("typeswitch.next") + casetype = fn.Pkg.typeOf(cond) + var condv Value + if casetype == tUntypedNil { + condv = emitCompare(fn, token.EQL, x, nilConst(x.Type()), token.NoPos) + ti = x + } else { + yok := emitTypeTest(fn, x, casetype, cc.Case) + ti = emitExtract(fn, yok, 0) + condv = emitExtract(fn, yok, 1) + } + emitIf(fn, condv, body, next) + fn.currentBlock = next + } + if len(cc.List) != 1 { + ti = x + } + fn.currentBlock = body + b.typeCaseBody(fn, cc, ti, done) + fn.currentBlock = next + } + if default_ != nil { + b.typeCaseBody(fn, default_, x, done) + } else { + emitJump(fn, done) + } + fn.currentBlock = done +} + +func (b *builder) typeCaseBody(fn *Function, cc *ast.CaseClause, x Value, done *BasicBlock) { + if obj := fn.Pkg.info.Implicits[cc]; obj != nil { + // In a switch y := x.(type), each case clause + // implicitly declares a distinct object y. + // In a single-type case, y has that type. + // In multi-type cases, 'case nil' and default, + // y has the same type as the interface operand. + emitStore(fn, fn.addNamedLocal(obj), x, obj.Pos()) + } + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + b.stmtList(fn, cc.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) +} + +// selectStmt emits to fn code for the select statement s, optionally +// labelled by label. +// +func (b *builder) selectStmt(fn *Function, s *ast.SelectStmt, label *lblock) { + // A blocking select of a single case degenerates to a + // simple send or receive. + // TODO(adonovan): opt: is this optimization worth its weight? + if len(s.Body.List) == 1 { + clause := s.Body.List[0].(*ast.CommClause) + if clause.Comm != nil { + b.stmt(fn, clause.Comm) + done := fn.newBasicBlock("select.done") + if label != nil { + label._break = done + } + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + b.stmtList(fn, clause.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) + fn.currentBlock = done + return + } + } + + // First evaluate all channels in all cases, and find + // the directions of each state. + var states []*SelectState + blocking := true + debugInfo := fn.debugInfo() + for _, clause := range s.Body.List { + var st *SelectState + switch comm := clause.(*ast.CommClause).Comm.(type) { + case nil: // default case + blocking = false + continue + + case *ast.SendStmt: // ch<- i + ch := b.expr(fn, comm.Chan) + st = &SelectState{ + Dir: types.SendOnly, + Chan: ch, + Send: emitConv(fn, b.expr(fn, comm.Value), + ch.Type().Underlying().(*types.Chan).Elem()), + Pos: comm.Arrow, + } + if debugInfo { + st.DebugNode = comm + } + + case *ast.AssignStmt: // x := <-ch + recv := unparen(comm.Rhs[0]).(*ast.UnaryExpr) + st = &SelectState{ + Dir: types.RecvOnly, + Chan: b.expr(fn, recv.X), + Pos: recv.OpPos, + } + if debugInfo { + st.DebugNode = recv + } + + case *ast.ExprStmt: // <-ch + recv := unparen(comm.X).(*ast.UnaryExpr) + st = &SelectState{ + Dir: types.RecvOnly, + Chan: b.expr(fn, recv.X), + Pos: recv.OpPos, + } + if debugInfo { + st.DebugNode = recv + } + } + states = append(states, st) + } + + // We dispatch on the (fair) result of Select using a + // sequential if-else chain, in effect: + // + // idx, recvOk, r0...r_n-1 := select(...) + // if idx == 0 { // receive on channel 0 (first receive => r0) + // x, ok := r0, recvOk + // ...state0... + // } else if v == 1 { // send on channel 1 + // ...state1... + // } else { + // ...default... + // } + sel := &Select{ + States: states, + Blocking: blocking, + } + sel.setPos(s.Select) + var vars []*types.Var + vars = append(vars, varIndex, varOk) + for _, st := range states { + if st.Dir == types.RecvOnly { + tElem := st.Chan.Type().Underlying().(*types.Chan).Elem() + vars = append(vars, anonVar(tElem)) + } + } + sel.setType(types.NewTuple(vars...)) + + fn.emit(sel) + idx := emitExtract(fn, sel, 0) + + done := fn.newBasicBlock("select.done") + if label != nil { + label._break = done + } + + var defaultBody *[]ast.Stmt + state := 0 + r := 2 // index in 'sel' tuple of value; increments if st.Dir==RECV + for _, cc := range s.Body.List { + clause := cc.(*ast.CommClause) + if clause.Comm == nil { + defaultBody = &clause.Body + continue + } + body := fn.newBasicBlock("select.body") + next := fn.newBasicBlock("select.next") + emitIf(fn, emitCompare(fn, token.EQL, idx, intConst(int64(state)), token.NoPos), body, next) + fn.currentBlock = body + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + switch comm := clause.Comm.(type) { + case *ast.ExprStmt: // <-ch + if debugInfo { + v := emitExtract(fn, sel, r) + emitDebugRef(fn, states[state].DebugNode.(ast.Expr), v, false) + } + r++ + + case *ast.AssignStmt: // x := <-states[state].Chan + if comm.Tok == token.DEFINE { + fn.addLocalForIdent(comm.Lhs[0].(*ast.Ident)) + } + x := b.addr(fn, comm.Lhs[0], false) // non-escaping + v := emitExtract(fn, sel, r) + if debugInfo { + emitDebugRef(fn, states[state].DebugNode.(ast.Expr), v, false) + } + x.store(fn, v) + + if len(comm.Lhs) == 2 { // x, ok := ... + if comm.Tok == token.DEFINE { + fn.addLocalForIdent(comm.Lhs[1].(*ast.Ident)) + } + ok := b.addr(fn, comm.Lhs[1], false) // non-escaping + ok.store(fn, emitExtract(fn, sel, 1)) + } + r++ + } + b.stmtList(fn, clause.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) + fn.currentBlock = next + state++ + } + if defaultBody != nil { + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + b.stmtList(fn, *defaultBody) + fn.targets = fn.targets.tail + } else { + // A blocking select must match some case. + // (This should really be a runtime.errorString, not a string.) + fn.emit(&Panic{ + X: emitConv(fn, stringConst("blocking select matched no case"), tEface), + }) + fn.currentBlock = fn.newBasicBlock("unreachable") + } + emitJump(fn, done) + fn.currentBlock = done +} + +// forStmt emits to fn code for the for statement s, optionally +// labelled by label. +// +func (b *builder) forStmt(fn *Function, s *ast.ForStmt, label *lblock) { + // ...init... + // jump loop + // loop: + // if cond goto body else done + // body: + // ...body... + // jump post + // post: (target of continue) + // ...post... + // jump loop + // done: (target of break) + if s.Init != nil { + b.stmt(fn, s.Init) + } + body := fn.newBasicBlock("for.body") + done := fn.newBasicBlock("for.done") // target of 'break' + loop := body // target of back-edge + if s.Cond != nil { + loop = fn.newBasicBlock("for.loop") + } + cont := loop // target of 'continue' + if s.Post != nil { + cont = fn.newBasicBlock("for.post") + } + if label != nil { + label._break = done + label._continue = cont + } + emitJump(fn, loop) + fn.currentBlock = loop + if loop != body { + b.cond(fn, s.Cond, body, done) + fn.currentBlock = body + } + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _continue: cont, + } + b.stmt(fn, s.Body) + fn.targets = fn.targets.tail + emitJump(fn, cont) + + if s.Post != nil { + fn.currentBlock = cont + b.stmt(fn, s.Post) + emitJump(fn, loop) // back-edge + } + fn.currentBlock = done +} + +// rangeIndexed emits to fn the header for an integer-indexed loop +// over array, *array or slice value x. +// The v result is defined only if tv is non-nil. +// forPos is the position of the "for" token. +// +func (b *builder) rangeIndexed(fn *Function, x Value, tv types.Type, pos token.Pos) (k, v Value, loop, done *BasicBlock) { + // + // length = len(x) + // index = -1 + // loop: (target of continue) + // index++ + // if index < length goto body else done + // body: + // k = index + // v = x[index] + // ...body... + // jump loop + // done: (target of break) + + // Determine number of iterations. + var length Value + if arr, ok := deref(x.Type()).Underlying().(*types.Array); ok { + // For array or *array, the number of iterations is + // known statically thanks to the type. We avoid a + // data dependence upon x, permitting later dead-code + // elimination if x is pure, static unrolling, etc. + // Ranging over a nil *array may have >0 iterations. + // We still generate code for x, in case it has effects. + length = intConst(arr.Len()) + } else { + // length = len(x). + var c Call + c.Call.Value = makeLen(x.Type()) + c.Call.Args = []Value{x} + c.setType(tInt) + length = fn.emit(&c) + } + + index := fn.addLocal(tInt, token.NoPos) + emitStore(fn, index, intConst(-1), pos) + + loop = fn.newBasicBlock("rangeindex.loop") + emitJump(fn, loop) + fn.currentBlock = loop + + incr := &BinOp{ + Op: token.ADD, + X: emitLoad(fn, index), + Y: vOne, + } + incr.setType(tInt) + emitStore(fn, index, fn.emit(incr), pos) + + body := fn.newBasicBlock("rangeindex.body") + done = fn.newBasicBlock("rangeindex.done") + emitIf(fn, emitCompare(fn, token.LSS, incr, length, token.NoPos), body, done) + fn.currentBlock = body + + k = emitLoad(fn, index) + if tv != nil { + switch t := x.Type().Underlying().(type) { + case *types.Array: + instr := &Index{ + X: x, + Index: k, + } + instr.setType(t.Elem()) + v = fn.emit(instr) + + case *types.Pointer: // *array + instr := &IndexAddr{ + X: x, + Index: k, + } + instr.setType(types.NewPointer(t.Elem().Underlying().(*types.Array).Elem())) + v = emitLoad(fn, fn.emit(instr)) + + case *types.Slice: + instr := &IndexAddr{ + X: x, + Index: k, + } + instr.setType(types.NewPointer(t.Elem())) + v = emitLoad(fn, fn.emit(instr)) + + default: + panic("rangeIndexed x:" + t.String()) + } + } + return +} + +// rangeIter emits to fn the header for a loop using +// Range/Next/Extract to iterate over map or string value x. +// tk and tv are the types of the key/value results k and v, or nil +// if the respective component is not wanted. +// +func (b *builder) rangeIter(fn *Function, x Value, tk, tv types.Type, pos token.Pos) (k, v Value, loop, done *BasicBlock) { + // + // it = range x + // loop: (target of continue) + // okv = next it (ok, key, value) + // ok = extract okv #0 + // if ok goto body else done + // body: + // k = extract okv #1 + // v = extract okv #2 + // ...body... + // jump loop + // done: (target of break) + // + + if tk == nil { + tk = tInvalid + } + if tv == nil { + tv = tInvalid + } + + rng := &Range{X: x} + rng.setPos(pos) + rng.setType(tRangeIter) + it := fn.emit(rng) + + loop = fn.newBasicBlock("rangeiter.loop") + emitJump(fn, loop) + fn.currentBlock = loop + + _, isString := x.Type().Underlying().(*types.Basic) + + okv := &Next{ + Iter: it, + IsString: isString, + } + okv.setType(types.NewTuple( + varOk, + newVar("k", tk), + newVar("v", tv), + )) + fn.emit(okv) + + body := fn.newBasicBlock("rangeiter.body") + done = fn.newBasicBlock("rangeiter.done") + emitIf(fn, emitExtract(fn, okv, 0), body, done) + fn.currentBlock = body + + if tk != tInvalid { + k = emitExtract(fn, okv, 1) + } + if tv != tInvalid { + v = emitExtract(fn, okv, 2) + } + return +} + +// rangeChan emits to fn the header for a loop that receives from +// channel x until it fails. +// tk is the channel's element type, or nil if the k result is +// not wanted +// pos is the position of the '=' or ':=' token. +// +func (b *builder) rangeChan(fn *Function, x Value, tk types.Type, pos token.Pos) (k Value, loop, done *BasicBlock) { + // + // loop: (target of continue) + // ko = <-x (key, ok) + // ok = extract ko #1 + // if ok goto body else done + // body: + // k = extract ko #0 + // ... + // goto loop + // done: (target of break) + + loop = fn.newBasicBlock("rangechan.loop") + emitJump(fn, loop) + fn.currentBlock = loop + recv := &UnOp{ + Op: token.ARROW, + X: x, + CommaOk: true, + } + recv.setPos(pos) + recv.setType(types.NewTuple( + newVar("k", x.Type().Underlying().(*types.Chan).Elem()), + varOk, + )) + ko := fn.emit(recv) + body := fn.newBasicBlock("rangechan.body") + done = fn.newBasicBlock("rangechan.done") + emitIf(fn, emitExtract(fn, ko, 1), body, done) + fn.currentBlock = body + if tk != nil { + k = emitExtract(fn, ko, 0) + } + return +} + +// rangeStmt emits to fn code for the range statement s, optionally +// labelled by label. +// +func (b *builder) rangeStmt(fn *Function, s *ast.RangeStmt, label *lblock) { + var tk, tv types.Type + if s.Key != nil && !isBlankIdent(s.Key) { + tk = fn.Pkg.typeOf(s.Key) + } + if s.Value != nil && !isBlankIdent(s.Value) { + tv = fn.Pkg.typeOf(s.Value) + } + + // If iteration variables are defined (:=), this + // occurs once outside the loop. + // + // Unlike a short variable declaration, a RangeStmt + // using := never redeclares an existing variable; it + // always creates a new one. + if s.Tok == token.DEFINE { + if tk != nil { + fn.addLocalForIdent(s.Key.(*ast.Ident)) + } + if tv != nil { + fn.addLocalForIdent(s.Value.(*ast.Ident)) + } + } + + x := b.expr(fn, s.X) + + var k, v Value + var loop, done *BasicBlock + switch rt := x.Type().Underlying().(type) { + case *types.Slice, *types.Array, *types.Pointer: // *array + k, v, loop, done = b.rangeIndexed(fn, x, tv, s.For) + + case *types.Chan: + k, loop, done = b.rangeChan(fn, x, tk, s.For) + + case *types.Map, *types.Basic: // string + k, v, loop, done = b.rangeIter(fn, x, tk, tv, s.For) + + default: + panic("Cannot range over: " + rt.String()) + } + + // Evaluate both LHS expressions before we update either. + var kl, vl lvalue + if tk != nil { + kl = b.addr(fn, s.Key, false) // non-escaping + } + if tv != nil { + vl = b.addr(fn, s.Value, false) // non-escaping + } + if tk != nil { + kl.store(fn, k) + } + if tv != nil { + vl.store(fn, v) + } + + if label != nil { + label._break = done + label._continue = loop + } + + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _continue: loop, + } + b.stmt(fn, s.Body) + fn.targets = fn.targets.tail + emitJump(fn, loop) // back-edge + fn.currentBlock = done +} + +// stmt lowers statement s to SSA form, emitting code to fn. +func (b *builder) stmt(fn *Function, _s ast.Stmt) { + // The label of the current statement. If non-nil, its _goto + // target is always set; its _break and _continue are set only + // within the body of switch/typeswitch/select/for/range. + // It is effectively an additional default-nil parameter of stmt(). + var label *lblock +start: + switch s := _s.(type) { + case *ast.EmptyStmt: + // ignore. (Usually removed by gofmt.) + + case *ast.DeclStmt: // Con, Var or Typ + d := s.Decl.(*ast.GenDecl) + if d.Tok == token.VAR { + for _, spec := range d.Specs { + if vs, ok := spec.(*ast.ValueSpec); ok { + b.localValueSpec(fn, vs) + } + } + } + + case *ast.LabeledStmt: + label = fn.labelledBlock(s.Label) + emitJump(fn, label._goto) + fn.currentBlock = label._goto + _s = s.Stmt + goto start // effectively: tailcall stmt(fn, s.Stmt, label) + + case *ast.ExprStmt: + b.expr(fn, s.X) + + case *ast.SendStmt: + fn.emit(&Send{ + Chan: b.expr(fn, s.Chan), + X: emitConv(fn, b.expr(fn, s.Value), + fn.Pkg.typeOf(s.Chan).Underlying().(*types.Chan).Elem()), + pos: s.Arrow, + }) + + case *ast.IncDecStmt: + op := token.ADD + if s.Tok == token.DEC { + op = token.SUB + } + loc := b.addr(fn, s.X, false) + b.assignOp(fn, loc, NewConst(exact.MakeInt64(1), loc.typ()), op) + + case *ast.AssignStmt: + switch s.Tok { + case token.ASSIGN, token.DEFINE: + b.assignStmt(fn, s.Lhs, s.Rhs, s.Tok == token.DEFINE) + + default: // +=, etc. + op := s.Tok + token.ADD - token.ADD_ASSIGN + b.assignOp(fn, b.addr(fn, s.Lhs[0], false), b.expr(fn, s.Rhs[0]), op) + } + + case *ast.GoStmt: + // The "intrinsics" new/make/len/cap are forbidden here. + // panic is treated like an ordinary function call. + v := Go{pos: s.Go} + b.setCall(fn, s.Call, &v.Call) + fn.emit(&v) + + case *ast.DeferStmt: + // The "intrinsics" new/make/len/cap are forbidden here. + // panic is treated like an ordinary function call. + v := Defer{pos: s.Defer} + b.setCall(fn, s.Call, &v.Call) + fn.emit(&v) + + // A deferred call can cause recovery from panic, + // and control resumes at the Recover block. + createRecoverBlock(fn) + + case *ast.ReturnStmt: + var results []Value + if len(s.Results) == 1 && fn.Signature.Results().Len() > 1 { + // Return of one expression in a multi-valued function. + tuple := b.exprN(fn, s.Results[0]) + ttuple := tuple.Type().(*types.Tuple) + for i, n := 0, ttuple.Len(); i < n; i++ { + results = append(results, + emitConv(fn, emitExtract(fn, tuple, i), + fn.Signature.Results().At(i).Type())) + } + } else { + // 1:1 return, or no-arg return in non-void function. + for i, r := range s.Results { + v := emitConv(fn, b.expr(fn, r), fn.Signature.Results().At(i).Type()) + results = append(results, v) + } + } + if fn.namedResults != nil { + // Function has named result parameters (NRPs). + // Perform parallel assignment of return operands to NRPs. + for i, r := range results { + emitStore(fn, fn.namedResults[i], r, s.Return) + } + } + // Run function calls deferred in this + // function when explicitly returning from it. + fn.emit(new(RunDefers)) + if fn.namedResults != nil { + // Reload NRPs to form the result tuple. + results = results[:0] + for _, r := range fn.namedResults { + results = append(results, emitLoad(fn, r)) + } + } + fn.emit(&Return{Results: results, pos: s.Return}) + fn.currentBlock = fn.newBasicBlock("unreachable") + + case *ast.BranchStmt: + var block *BasicBlock + switch s.Tok { + case token.BREAK: + if s.Label != nil { + block = fn.labelledBlock(s.Label)._break + } else { + for t := fn.targets; t != nil && block == nil; t = t.tail { + block = t._break + } + } + + case token.CONTINUE: + if s.Label != nil { + block = fn.labelledBlock(s.Label)._continue + } else { + for t := fn.targets; t != nil && block == nil; t = t.tail { + block = t._continue + } + } + + case token.FALLTHROUGH: + for t := fn.targets; t != nil && block == nil; t = t.tail { + block = t._fallthrough + } + + case token.GOTO: + block = fn.labelledBlock(s.Label)._goto + } + emitJump(fn, block) + fn.currentBlock = fn.newBasicBlock("unreachable") + + case *ast.BlockStmt: + b.stmtList(fn, s.List) + + case *ast.IfStmt: + if s.Init != nil { + b.stmt(fn, s.Init) + } + then := fn.newBasicBlock("if.then") + done := fn.newBasicBlock("if.done") + els := done + if s.Else != nil { + els = fn.newBasicBlock("if.else") + } + b.cond(fn, s.Cond, then, els) + fn.currentBlock = then + b.stmt(fn, s.Body) + emitJump(fn, done) + + if s.Else != nil { + fn.currentBlock = els + b.stmt(fn, s.Else) + emitJump(fn, done) + } + + fn.currentBlock = done + + case *ast.SwitchStmt: + b.switchStmt(fn, s, label) + + case *ast.TypeSwitchStmt: + b.typeSwitchStmt(fn, s, label) + + case *ast.SelectStmt: + b.selectStmt(fn, s, label) + + case *ast.ForStmt: + b.forStmt(fn, s, label) + + case *ast.RangeStmt: + b.rangeStmt(fn, s, label) + + default: + panic(fmt.Sprintf("unexpected statement kind: %T", s)) + } +} + +// buildFunction builds SSA code for the body of function fn. Idempotent. +func (b *builder) buildFunction(fn *Function) { + if fn.Blocks != nil { + return // building already started + } + + var recvField *ast.FieldList + var body *ast.BlockStmt + var functype *ast.FuncType + switch n := fn.syntax.(type) { + case nil: + return // not a Go source function. (Synthetic, or from object file.) + case *ast.FuncDecl: + functype = n.Type + recvField = n.Recv + body = n.Body + case *ast.FuncLit: + functype = n.Type + body = n.Body + default: + panic(n) + } + + if body == nil { + // External function. + if fn.Params == nil { + // This condition ensures we add a non-empty + // params list once only, but we may attempt + // the degenerate empty case repeatedly. + // TODO(adonovan): opt: don't do that. + + // We set Function.Params even though there is no body + // code to reference them. This simplifies clients. + if recv := fn.Signature.Recv(); recv != nil { + fn.addParamObj(recv) + } + params := fn.Signature.Params() + for i, n := 0, params.Len(); i < n; i++ { + fn.addParamObj(params.At(i)) + } + } + return + } + if fn.Prog.mode&LogSource != 0 { + defer logStack("build function %s @ %s", fn, fn.Prog.Fset.Position(fn.pos))() + } + fn.startBody() + fn.createSyntacticParams(recvField, functype) + b.stmt(fn, body) + if cb := fn.currentBlock; cb != nil && (cb == fn.Blocks[0] || cb == fn.Recover || cb.Preds != nil) { + // Control fell off the end of the function's body block. + // + // Block optimizations eliminate the current block, if + // unreachable. It is a builder invariant that + // if this no-arg return is ill-typed for + // fn.Signature.Results, this block must be + // unreachable. The sanity checker checks this. + fn.emit(new(RunDefers)) + fn.emit(new(Return)) + } + fn.finishBody() +} + +// buildFuncDecl builds SSA code for the function or method declared +// by decl in package pkg. +// +func (b *builder) buildFuncDecl(pkg *Package, decl *ast.FuncDecl) { + id := decl.Name + if isBlankIdent(id) { + return // discard + } + fn := pkg.values[pkg.info.Defs[id]].(*Function) + if decl.Recv == nil && id.Name == "init" { + var v Call + v.Call.Value = fn + v.setType(types.NewTuple()) + pkg.init.emit(&v) + } + b.buildFunction(fn) +} + +// Build calls Package.Build for each package in prog. +// Building occurs in parallel unless the BuildSerially mode flag was set. +// +// Build is intended for whole-program analysis; a typical compiler +// need only build a single package. +// +// Build is idempotent and thread-safe. +// +func (prog *Program) Build() { + var wg sync.WaitGroup + for _, p := range prog.packages { + if prog.mode&BuildSerially != 0 { + p.Build() + } else { + wg.Add(1) + go func(p *Package) { + p.Build() + wg.Done() + }(p) + } + } + wg.Wait() +} + +// Build builds SSA code for all functions and vars in package p. +// +// Precondition: CreatePackage must have been called for all of p's +// direct imports (and hence its direct imports must have been +// error-free). +// +// Build is idempotent and thread-safe. +// +func (p *Package) Build() { p.buildOnce.Do(p.build) } + +func (p *Package) build() { + if p.info == nil { + return // synthetic package, e.g. "testmain" + } + + // Ensure we have runtime type info for all exported members. + // TODO(adonovan): ideally belongs in memberFromObject, but + // that would require package creation in topological order. + for name, mem := range p.Members { + if ast.IsExported(name) { + p.Prog.needMethodsOf(mem.Type()) + } + } + if p.Prog.mode&LogSource != 0 { + defer logStack("build %s", p)() + } + init := p.init + init.startBody() + + var done *BasicBlock + + if p.Prog.mode&BareInits == 0 { + // Make init() skip if package is already initialized. + initguard := p.Var("init$guard") + doinit := init.newBasicBlock("init.start") + done = init.newBasicBlock("init.done") + emitIf(init, emitLoad(init, initguard), done, doinit) + init.currentBlock = doinit + emitStore(init, initguard, vTrue, token.NoPos) + + // Call the init() function of each package we import. + for _, pkg := range p.Pkg.Imports() { + prereq := p.Prog.packages[pkg] + if prereq == nil { + panic(fmt.Sprintf("Package(%q).Build(): unsatisfied import: Program.CreatePackage(%q) was not called", p.Pkg.Path(), pkg.Path())) + } + var v Call + v.Call.Value = prereq.init + v.Call.pos = init.pos + v.setType(types.NewTuple()) + init.emit(&v) + } + } + + var b builder + + // Initialize package-level vars in correct order. + for _, varinit := range p.info.InitOrder { + if init.Prog.mode&LogSource != 0 { + fmt.Fprintf(os.Stderr, "build global initializer %v @ %s\n", + varinit.Lhs, p.Prog.Fset.Position(varinit.Rhs.Pos())) + } + if len(varinit.Lhs) == 1 { + // 1:1 initialization: var x, y = a(), b() + var lval lvalue + if v := varinit.Lhs[0]; v.Name() != "_" { + lval = &address{addr: p.values[v].(*Global), pos: v.Pos()} + } else { + lval = blank{} + } + b.assign(init, lval, varinit.Rhs, true, nil) + } else { + // n:1 initialization: var x, y := f() + tuple := b.exprN(init, varinit.Rhs) + for i, v := range varinit.Lhs { + if v.Name() == "_" { + continue + } + emitStore(init, p.values[v].(*Global), emitExtract(init, tuple, i), v.Pos()) + } + } + } + + // Build all package-level functions, init functions + // and methods, including unreachable/blank ones. + // We build them in source order, but it's not significant. + for _, file := range p.files { + for _, decl := range file.Decls { + if decl, ok := decl.(*ast.FuncDecl); ok { + b.buildFuncDecl(p, decl) + } + } + } + + // Finish up init(). + if p.Prog.mode&BareInits == 0 { + emitJump(init, done) + init.currentBlock = done + } + init.emit(new(Return)) + init.finishBody() + + p.info = nil // We no longer need ASTs or go/types deductions. + + if p.Prog.mode&SanityCheckFunctions != 0 { + sanityCheckPackage(p) + } +} + +// Like ObjectOf, but panics instead of returning nil. +// Only valid during p's create and build phases. +func (p *Package) objectOf(id *ast.Ident) types.Object { + if o := p.info.ObjectOf(id); o != nil { + return o + } + panic(fmt.Sprintf("no types.Object for ast.Ident %s @ %s", + id.Name, p.Prog.Fset.Position(id.Pos()))) +} + +// Like TypeOf, but panics instead of returning nil. +// Only valid during p's create and build phases. +func (p *Package) typeOf(e ast.Expr) types.Type { + if T := p.info.TypeOf(e); T != nil { + return T + } + panic(fmt.Sprintf("no type for %T @ %s", + e, p.Prog.Fset.Position(e.Pos()))) +} diff --git a/vendor/golang.org/x/tools/go/ssa/builder_test.go b/vendor/golang.org/x/tools/go/ssa/builder_test.go new file mode 100644 index 0000000..c45f930 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/builder_test.go @@ -0,0 +1,500 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa_test + +import ( + "bytes" + "go/ast" + "go/importer" + "go/parser" + "go/token" + "go/types" + "os" + "reflect" + "sort" + "strings" + "testing" + + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +func isEmpty(f *ssa.Function) bool { return f.Blocks == nil } + +// Tests that programs partially loaded from gc object files contain +// functions with no code for the external portions, but are otherwise ok. +func TestBuildPackage(t *testing.T) { + input := ` +package main + +import ( + "bytes" + "io" + "testing" +) + +func main() { + var t testing.T + t.Parallel() // static call to external declared method + t.Fail() // static call to promoted external declared method + testing.Short() // static call to external package-level function + + var w io.Writer = new(bytes.Buffer) + w.Write(nil) // interface invoke of external declared method +} +` + + // Parse the file. + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "input.go", input, 0) + if err != nil { + t.Error(err) + return + } + + // Build an SSA program from the parsed file. + // Load its dependencies from gc binary export data. + mainPkg, _, err := ssautil.BuildPackage(&types.Config{Importer: importer.Default()}, fset, + types.NewPackage("main", ""), []*ast.File{f}, ssa.SanityCheckFunctions) + if err != nil { + t.Error(err) + return + } + + // The main package, its direct and indirect dependencies are loaded. + deps := []string{ + // directly imported dependencies: + "bytes", "io", "testing", + // indirect dependencies mentioned by + // the direct imports' export data + "sync", "unicode", "time", + } + + prog := mainPkg.Prog + all := prog.AllPackages() + if len(all) <= len(deps) { + t.Errorf("unexpected set of loaded packages: %q", all) + } + for _, path := range deps { + pkg := prog.ImportedPackage(path) + if pkg == nil { + t.Errorf("package not loaded: %q", path) + continue + } + + // External packages should have no function bodies (except for wrappers). + isExt := pkg != mainPkg + + // init() + if isExt && !isEmpty(pkg.Func("init")) { + t.Errorf("external package %s has non-empty init", pkg) + } else if !isExt && isEmpty(pkg.Func("init")) { + t.Errorf("main package %s has empty init", pkg) + } + + for _, mem := range pkg.Members { + switch mem := mem.(type) { + case *ssa.Function: + // Functions at package level. + if isExt && !isEmpty(mem) { + t.Errorf("external function %s is non-empty", mem) + } else if !isExt && isEmpty(mem) { + t.Errorf("function %s is empty", mem) + } + + case *ssa.Type: + // Methods of named types T. + // (In this test, all exported methods belong to *T not T.) + if !isExt { + t.Fatalf("unexpected name type in main package: %s", mem) + } + mset := prog.MethodSets.MethodSet(types.NewPointer(mem.Type())) + for i, n := 0, mset.Len(); i < n; i++ { + m := prog.MethodValue(mset.At(i)) + // For external types, only synthetic wrappers have code. + expExt := !strings.Contains(m.Synthetic, "wrapper") + if expExt && !isEmpty(m) { + t.Errorf("external method %s is non-empty: %s", + m, m.Synthetic) + } else if !expExt && isEmpty(m) { + t.Errorf("method function %s is empty: %s", + m, m.Synthetic) + } + } + } + } + } + + expectedCallee := []string{ + "(*testing.T).Parallel", + "(*testing.common).Fail", + "testing.Short", + "N/A", + } + callNum := 0 + for _, b := range mainPkg.Func("main").Blocks { + for _, instr := range b.Instrs { + switch instr := instr.(type) { + case ssa.CallInstruction: + call := instr.Common() + if want := expectedCallee[callNum]; want != "N/A" { + got := call.StaticCallee().String() + if want != got { + t.Errorf("call #%d from main.main: got callee %s, want %s", + callNum, got, want) + } + } + callNum++ + } + } + } + if callNum != 4 { + t.Errorf("in main.main: got %d calls, want %d", callNum, 4) + } +} + +// TestRuntimeTypes tests that (*Program).RuntimeTypes() includes all necessary types. +func TestRuntimeTypes(t *testing.T) { + tests := []struct { + input string + want []string + }{ + // An exported package-level type is needed. + {`package A; type T struct{}; func (T) f() {}`, + []string{"*p.T", "p.T"}, + }, + // An unexported package-level type is not needed. + {`package B; type t struct{}; func (t) f() {}`, + nil, + }, + // Subcomponents of type of exported package-level var are needed. + {`package C; import "bytes"; var V struct {*bytes.Buffer}`, + []string{"*bytes.Buffer", "*struct{*bytes.Buffer}", "struct{*bytes.Buffer}"}, + }, + // Subcomponents of type of unexported package-level var are not needed. + {`package D; import "bytes"; var v struct {*bytes.Buffer}`, + nil, + }, + // Subcomponents of type of exported package-level function are needed. + {`package E; import "bytes"; func F(struct {*bytes.Buffer}) {}`, + []string{"*bytes.Buffer", "struct{*bytes.Buffer}"}, + }, + // Subcomponents of type of unexported package-level function are not needed. + {`package F; import "bytes"; func f(struct {*bytes.Buffer}) {}`, + nil, + }, + // Subcomponents of type of exported method of uninstantiated unexported type are not needed. + {`package G; import "bytes"; type x struct{}; func (x) G(struct {*bytes.Buffer}) {}; var v x`, + nil, + }, + // ...unless used by MakeInterface. + {`package G2; import "bytes"; type x struct{}; func (x) G(struct {*bytes.Buffer}) {}; var v interface{} = x{}`, + []string{"*bytes.Buffer", "*p.x", "p.x", "struct{*bytes.Buffer}"}, + }, + // Subcomponents of type of unexported method are not needed. + {`package I; import "bytes"; type X struct{}; func (X) G(struct {*bytes.Buffer}) {}`, + []string{"*bytes.Buffer", "*p.X", "p.X", "struct{*bytes.Buffer}"}, + }, + // Local types aren't needed. + {`package J; import "bytes"; func f() { type T struct {*bytes.Buffer}; var t T; _ = t }`, + nil, + }, + // ...unless used by MakeInterface. + {`package K; import "bytes"; func f() { type T struct {*bytes.Buffer}; _ = interface{}(T{}) }`, + []string{"*bytes.Buffer", "*p.T", "p.T"}, + }, + // Types used as operand of MakeInterface are needed. + {`package L; import "bytes"; func f() { _ = interface{}(struct{*bytes.Buffer}{}) }`, + []string{"*bytes.Buffer", "struct{*bytes.Buffer}"}, + }, + // MakeInterface is optimized away when storing to a blank. + {`package M; import "bytes"; var _ interface{} = struct{*bytes.Buffer}{}`, + nil, + }, + } + for _, test := range tests { + // Parse the file. + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "input.go", test.input, 0) + if err != nil { + t.Errorf("test %q: %s", test.input[:15], err) + continue + } + + // Create a single-file main package. + // Load dependencies from gc binary export data. + ssapkg, _, err := ssautil.BuildPackage(&types.Config{Importer: importer.Default()}, fset, + types.NewPackage("p", ""), []*ast.File{f}, ssa.SanityCheckFunctions) + if err != nil { + t.Errorf("test %q: %s", test.input[:15], err) + continue + } + + var typstrs []string + for _, T := range ssapkg.Prog.RuntimeTypes() { + typstrs = append(typstrs, T.String()) + } + sort.Strings(typstrs) + + if !reflect.DeepEqual(typstrs, test.want) { + t.Errorf("test 'package %s': got %q, want %q", + f.Name.Name, typstrs, test.want) + } + } +} + +// TestInit tests that synthesized init functions are correctly formed. +// Bare init functions omit calls to dependent init functions and the use of +// an init guard. They are useful in cases where the client uses a different +// calling convention for init functions, or cases where it is easier for a +// client to analyze bare init functions. Both of these aspects are used by +// the llgo compiler for simpler integration with gccgo's runtime library, +// and to simplify the analysis whereby it deduces which stores to globals +// can be lowered to global initializers. +func TestInit(t *testing.T) { + tests := []struct { + mode ssa.BuilderMode + input, want string + }{ + {0, `package A; import _ "errors"; var i int = 42`, + `# Name: A.init +# Package: A +# Synthetic: package initializer +func init(): +0: entry P:0 S:2 + t0 = *init$guard bool + if t0 goto 2 else 1 +1: init.start P:1 S:1 + *init$guard = true:bool + t1 = errors.init() () + *i = 42:int + jump 2 +2: init.done P:2 S:0 + return + +`}, + {ssa.BareInits, `package B; import _ "errors"; var i int = 42`, + `# Name: B.init +# Package: B +# Synthetic: package initializer +func init(): +0: entry P:0 S:0 + *i = 42:int + return + +`}, + } + for _, test := range tests { + // Create a single-file main package. + var conf loader.Config + f, err := conf.ParseFile("<input>", test.input) + if err != nil { + t.Errorf("test %q: %s", test.input[:15], err) + continue + } + conf.CreateFromFiles(f.Name.Name, f) + + lprog, err := conf.Load() + if err != nil { + t.Errorf("test 'package %s': Load: %s", f.Name.Name, err) + continue + } + prog := ssautil.CreateProgram(lprog, test.mode) + mainPkg := prog.Package(lprog.Created[0].Pkg) + prog.Build() + initFunc := mainPkg.Func("init") + if initFunc == nil { + t.Errorf("test 'package %s': no init function", f.Name.Name) + continue + } + + var initbuf bytes.Buffer + _, err = initFunc.WriteTo(&initbuf) + if err != nil { + t.Errorf("test 'package %s': WriteTo: %s", f.Name.Name, err) + continue + } + + if initbuf.String() != test.want { + t.Errorf("test 'package %s': got %s, want %s", f.Name.Name, initbuf.String(), test.want) + } + } +} + +// TestSyntheticFuncs checks that the expected synthetic functions are +// created, reachable, and not duplicated. +func TestSyntheticFuncs(t *testing.T) { + const input = `package P +type T int +func (T) f() int +func (*T) g() int +var ( + // thunks + a = T.f + b = T.f + c = (struct{T}).f + d = (struct{T}).f + e = (*T).g + f = (*T).g + g = (struct{*T}).g + h = (struct{*T}).g + + // bounds + i = T(0).f + j = T(0).f + k = new(T).g + l = new(T).g + + // wrappers + m interface{} = struct{T}{} + n interface{} = struct{T}{} + o interface{} = struct{*T}{} + p interface{} = struct{*T}{} + q interface{} = new(struct{T}) + r interface{} = new(struct{T}) + s interface{} = new(struct{*T}) + t interface{} = new(struct{*T}) +) +` + // Parse + var conf loader.Config + f, err := conf.ParseFile("<input>", input) + if err != nil { + t.Fatalf("parse: %v", err) + } + conf.CreateFromFiles(f.Name.Name, f) + + // Load + lprog, err := conf.Load() + if err != nil { + t.Fatalf("Load: %v", err) + } + + // Create and build SSA + prog := ssautil.CreateProgram(lprog, 0) + prog.Build() + + // Enumerate reachable synthetic functions + want := map[string]string{ + "(*P.T).g$bound": "bound method wrapper for func (*P.T).g() int", + "(P.T).f$bound": "bound method wrapper for func (P.T).f() int", + + "(*P.T).g$thunk": "thunk for func (*P.T).g() int", + "(P.T).f$thunk": "thunk for func (P.T).f() int", + "(struct{*P.T}).g$thunk": "thunk for func (*P.T).g() int", + "(struct{P.T}).f$thunk": "thunk for func (P.T).f() int", + + "(*P.T).f": "wrapper for func (P.T).f() int", + "(*struct{*P.T}).f": "wrapper for func (P.T).f() int", + "(*struct{*P.T}).g": "wrapper for func (*P.T).g() int", + "(*struct{P.T}).f": "wrapper for func (P.T).f() int", + "(*struct{P.T}).g": "wrapper for func (*P.T).g() int", + "(struct{*P.T}).f": "wrapper for func (P.T).f() int", + "(struct{*P.T}).g": "wrapper for func (*P.T).g() int", + "(struct{P.T}).f": "wrapper for func (P.T).f() int", + + "P.init": "package initializer", + } + for fn := range ssautil.AllFunctions(prog) { + if fn.Synthetic == "" { + continue + } + name := fn.String() + wantDescr, ok := want[name] + if !ok { + t.Errorf("got unexpected/duplicate func: %q: %q", name, fn.Synthetic) + continue + } + delete(want, name) + + if wantDescr != fn.Synthetic { + t.Errorf("(%s).Synthetic = %q, want %q", name, fn.Synthetic, wantDescr) + } + } + for fn, descr := range want { + t.Errorf("want func: %q: %q", fn, descr) + } +} + +// TestPhiElimination ensures that dead phis, including those that +// participate in a cycle, are properly eliminated. +func TestPhiElimination(t *testing.T) { + const input = ` +package p + +func f() error + +func g(slice []int) { + for { + for range slice { + // e should not be lifted to a dead φ-node. + e := f() + h(e) + } + } +} + +func h(error) +` + // The SSA code for this function should look something like this: + // 0: + // jump 1 + // 1: + // t0 = len(slice) + // jump 2 + // 2: + // t1 = phi [1: -1:int, 3: t2] + // t2 = t1 + 1:int + // t3 = t2 < t0 + // if t3 goto 3 else 1 + // 3: + // t4 = f() + // t5 = h(t4) + // jump 2 + // + // But earlier versions of the SSA construction algorithm would + // additionally generate this cycle of dead phis: + // + // 1: + // t7 = phi [0: nil:error, 2: t8] #e + // ... + // 2: + // t8 = phi [1: t7, 3: t4] #e + // ... + + // Parse + var conf loader.Config + f, err := conf.ParseFile("<input>", input) + if err != nil { + t.Fatalf("parse: %v", err) + } + conf.CreateFromFiles("p", f) + + // Load + lprog, err := conf.Load() + if err != nil { + t.Fatalf("Load: %v", err) + } + + // Create and build SSA + prog := ssautil.CreateProgram(lprog, 0) + p := prog.Package(lprog.Package("p").Pkg) + p.Build() + g := p.Func("g") + + phis := 0 + for _, b := range g.Blocks { + for _, instr := range b.Instrs { + if _, ok := instr.(*ssa.Phi); ok { + phis++ + } + } + } + if phis != 1 { + g.WriteTo(os.Stderr) + t.Errorf("expected a single Phi (for the range index), got %d", phis) + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/const.go b/vendor/golang.org/x/tools/go/ssa/const.go new file mode 100644 index 0000000..2870eea --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/const.go @@ -0,0 +1,169 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines the Const SSA value type. + +import ( + "fmt" + exact "go/constant" + "go/token" + "go/types" + "strconv" +) + +// NewConst returns a new constant of the specified value and type. +// val must be valid according to the specification of Const.Value. +// +func NewConst(val exact.Value, typ types.Type) *Const { + return &Const{typ, val} +} + +// intConst returns an 'int' constant that evaluates to i. +// (i is an int64 in case the host is narrower than the target.) +func intConst(i int64) *Const { + return NewConst(exact.MakeInt64(i), tInt) +} + +// nilConst returns a nil constant of the specified type, which may +// be any reference type, including interfaces. +// +func nilConst(typ types.Type) *Const { + return NewConst(nil, typ) +} + +// stringConst returns a 'string' constant that evaluates to s. +func stringConst(s string) *Const { + return NewConst(exact.MakeString(s), tString) +} + +// zeroConst returns a new "zero" constant of the specified type, +// which must not be an array or struct type: the zero values of +// aggregates are well-defined but cannot be represented by Const. +// +func zeroConst(t types.Type) *Const { + switch t := t.(type) { + case *types.Basic: + switch { + case t.Info()&types.IsBoolean != 0: + return NewConst(exact.MakeBool(false), t) + case t.Info()&types.IsNumeric != 0: + return NewConst(exact.MakeInt64(0), t) + case t.Info()&types.IsString != 0: + return NewConst(exact.MakeString(""), t) + case t.Kind() == types.UnsafePointer: + fallthrough + case t.Kind() == types.UntypedNil: + return nilConst(t) + default: + panic(fmt.Sprint("zeroConst for unexpected type:", t)) + } + case *types.Pointer, *types.Slice, *types.Interface, *types.Chan, *types.Map, *types.Signature: + return nilConst(t) + case *types.Named: + return NewConst(zeroConst(t.Underlying()).Value, t) + case *types.Array, *types.Struct, *types.Tuple: + panic(fmt.Sprint("zeroConst applied to aggregate:", t)) + } + panic(fmt.Sprint("zeroConst: unexpected ", t)) +} + +func (c *Const) RelString(from *types.Package) string { + var s string + if c.Value == nil { + s = "nil" + } else if c.Value.Kind() == exact.String { + s = exact.StringVal(c.Value) + const max = 20 + // TODO(adonovan): don't cut a rune in half. + if len(s) > max { + s = s[:max-3] + "..." // abbreviate + } + s = strconv.Quote(s) + } else { + s = c.Value.String() + } + return s + ":" + relType(c.Type(), from) +} + +func (c *Const) Name() string { + return c.RelString(nil) +} + +func (c *Const) String() string { + return c.Name() +} + +func (c *Const) Type() types.Type { + return c.typ +} + +func (c *Const) Referrers() *[]Instruction { + return nil +} + +func (c *Const) Parent() *Function { return nil } + +func (c *Const) Pos() token.Pos { + return token.NoPos +} + +// IsNil returns true if this constant represents a typed or untyped nil value. +func (c *Const) IsNil() bool { + return c.Value == nil +} + +// TODO(adonovan): move everything below into golang.org/x/tools/go/ssa/interp. + +// Int64 returns the numeric value of this constant truncated to fit +// a signed 64-bit integer. +// +func (c *Const) Int64() int64 { + switch x := exact.ToInt(c.Value); x.Kind() { + case exact.Int: + if i, ok := exact.Int64Val(x); ok { + return i + } + return 0 + case exact.Float: + f, _ := exact.Float64Val(x) + return int64(f) + } + panic(fmt.Sprintf("unexpected constant value: %T", c.Value)) +} + +// Uint64 returns the numeric value of this constant truncated to fit +// an unsigned 64-bit integer. +// +func (c *Const) Uint64() uint64 { + switch x := exact.ToInt(c.Value); x.Kind() { + case exact.Int: + if u, ok := exact.Uint64Val(x); ok { + return u + } + return 0 + case exact.Float: + f, _ := exact.Float64Val(x) + return uint64(f) + } + panic(fmt.Sprintf("unexpected constant value: %T", c.Value)) +} + +// Float64 returns the numeric value of this constant truncated to fit +// a float64. +// +func (c *Const) Float64() float64 { + f, _ := exact.Float64Val(c.Value) + return f +} + +// Complex128 returns the complex value of this constant truncated to +// fit a complex128. +// +func (c *Const) Complex128() complex128 { + re, _ := exact.Float64Val(exact.Real(c.Value)) + im, _ := exact.Float64Val(exact.Imag(c.Value)) + return complex(re, im) +} diff --git a/vendor/golang.org/x/tools/go/ssa/create.go b/vendor/golang.org/x/tools/go/ssa/create.go new file mode 100644 index 0000000..69ac12b --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/create.go @@ -0,0 +1,263 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the CREATE phase of SSA construction. +// See builder.go for explanation. + +import ( + "fmt" + "go/ast" + "go/token" + "go/types" + "os" + "sync" + + "golang.org/x/tools/go/types/typeutil" +) + +// NewProgram returns a new SSA Program. +// +// mode controls diagnostics and checking during SSA construction. +// +func NewProgram(fset *token.FileSet, mode BuilderMode) *Program { + prog := &Program{ + Fset: fset, + imported: make(map[string]*Package), + packages: make(map[*types.Package]*Package), + thunks: make(map[selectionKey]*Function), + bounds: make(map[*types.Func]*Function), + mode: mode, + } + + h := typeutil.MakeHasher() // protected by methodsMu, in effect + prog.methodSets.SetHasher(h) + prog.canon.SetHasher(h) + + return prog +} + +// memberFromObject populates package pkg with a member for the +// typechecker object obj. +// +// For objects from Go source code, syntax is the associated syntax +// tree (for funcs and vars only); it will be used during the build +// phase. +// +func memberFromObject(pkg *Package, obj types.Object, syntax ast.Node) { + name := obj.Name() + switch obj := obj.(type) { + case *types.Builtin: + if pkg.Pkg != types.Unsafe { + panic("unexpected builtin object: " + obj.String()) + } + + case *types.TypeName: + pkg.Members[name] = &Type{ + object: obj, + pkg: pkg, + } + + case *types.Const: + c := &NamedConst{ + object: obj, + Value: NewConst(obj.Val(), obj.Type()), + pkg: pkg, + } + pkg.values[obj] = c.Value + pkg.Members[name] = c + + case *types.Var: + g := &Global{ + Pkg: pkg, + name: name, + object: obj, + typ: types.NewPointer(obj.Type()), // address + pos: obj.Pos(), + } + pkg.values[obj] = g + pkg.Members[name] = g + + case *types.Func: + sig := obj.Type().(*types.Signature) + if sig.Recv() == nil && name == "init" { + pkg.ninit++ + name = fmt.Sprintf("init#%d", pkg.ninit) + } + fn := &Function{ + name: name, + object: obj, + Signature: sig, + syntax: syntax, + pos: obj.Pos(), + Pkg: pkg, + Prog: pkg.Prog, + } + if syntax == nil { + fn.Synthetic = "loaded from gc object file" + } + + pkg.values[obj] = fn + if sig.Recv() == nil { + pkg.Members[name] = fn // package-level function + } + + default: // (incl. *types.Package) + panic("unexpected Object type: " + obj.String()) + } +} + +// membersFromDecl populates package pkg with members for each +// typechecker object (var, func, const or type) associated with the +// specified decl. +// +func membersFromDecl(pkg *Package, decl ast.Decl) { + switch decl := decl.(type) { + case *ast.GenDecl: // import, const, type or var + switch decl.Tok { + case token.CONST: + for _, spec := range decl.Specs { + for _, id := range spec.(*ast.ValueSpec).Names { + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], nil) + } + } + } + + case token.VAR: + for _, spec := range decl.Specs { + for _, id := range spec.(*ast.ValueSpec).Names { + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], spec) + } + } + } + + case token.TYPE: + for _, spec := range decl.Specs { + id := spec.(*ast.TypeSpec).Name + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], nil) + } + } + } + + case *ast.FuncDecl: + id := decl.Name + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], decl) + } + } +} + +// CreatePackage constructs and returns an SSA Package from the +// specified type-checked, error-free file ASTs, and populates its +// Members mapping. +// +// importable determines whether this package should be returned by a +// subsequent call to ImportedPackage(pkg.Path()). +// +// The real work of building SSA form for each function is not done +// until a subsequent call to Package.Build(). +// +func (prog *Program) CreatePackage(pkg *types.Package, files []*ast.File, info *types.Info, importable bool) *Package { + p := &Package{ + Prog: prog, + Members: make(map[string]Member), + values: make(map[types.Object]Value), + Pkg: pkg, + info: info, // transient (CREATE and BUILD phases) + files: files, // transient (CREATE and BUILD phases) + } + + // Add init() function. + p.init = &Function{ + name: "init", + Signature: new(types.Signature), + Synthetic: "package initializer", + Pkg: p, + Prog: prog, + } + p.Members[p.init.name] = p.init + + // CREATE phase. + // Allocate all package members: vars, funcs, consts and types. + if len(files) > 0 { + // Go source package. + for _, file := range files { + for _, decl := range file.Decls { + membersFromDecl(p, decl) + } + } + } else { + // GC-compiled binary package (or "unsafe") + // No code. + // No position information. + scope := p.Pkg.Scope() + for _, name := range scope.Names() { + obj := scope.Lookup(name) + memberFromObject(p, obj, nil) + if obj, ok := obj.(*types.TypeName); ok { + if named, ok := obj.Type().(*types.Named); ok { + for i, n := 0, named.NumMethods(); i < n; i++ { + memberFromObject(p, named.Method(i), nil) + } + } + } + } + } + + if prog.mode&BareInits == 0 { + // Add initializer guard variable. + initguard := &Global{ + Pkg: p, + name: "init$guard", + typ: types.NewPointer(tBool), + } + p.Members[initguard.Name()] = initguard + } + + if prog.mode&GlobalDebug != 0 { + p.SetDebugMode(true) + } + + if prog.mode&PrintPackages != 0 { + printMu.Lock() + p.WriteTo(os.Stdout) + printMu.Unlock() + } + + if importable { + prog.imported[p.Pkg.Path()] = p + } + prog.packages[p.Pkg] = p + + return p +} + +// printMu serializes printing of Packages/Functions to stdout. +var printMu sync.Mutex + +// AllPackages returns a new slice containing all packages in the +// program prog in unspecified order. +// +func (prog *Program) AllPackages() []*Package { + pkgs := make([]*Package, 0, len(prog.packages)) + for _, pkg := range prog.packages { + pkgs = append(pkgs, pkg) + } + return pkgs +} + +// ImportedPackage returns the importable SSA Package whose import +// path is path, or nil if no such SSA package has been created. +// +// Not all packages are importable. For example, no import +// declaration can resolve to the x_test package created by 'go test' +// or the ad-hoc main package created 'go build foo.go'. +// +func (prog *Program) ImportedPackage(path string) *Package { + return prog.imported[path] +} diff --git a/vendor/golang.org/x/tools/go/ssa/doc.go b/vendor/golang.org/x/tools/go/ssa/doc.go new file mode 100644 index 0000000..2aa04f4 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/doc.go @@ -0,0 +1,123 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package ssa defines a representation of the elements of Go programs +// (packages, types, functions, variables and constants) using a +// static single-assignment (SSA) form intermediate representation +// (IR) for the bodies of functions. +// +// THIS INTERFACE IS EXPERIMENTAL AND IS LIKELY TO CHANGE. +// +// For an introduction to SSA form, see +// http://en.wikipedia.org/wiki/Static_single_assignment_form. +// This page provides a broader reading list: +// http://www.dcs.gla.ac.uk/~jsinger/ssa.html. +// +// The level of abstraction of the SSA form is intentionally close to +// the source language to facilitate construction of source analysis +// tools. It is not intended for machine code generation. +// +// All looping, branching and switching constructs are replaced with +// unstructured control flow. Higher-level control flow constructs +// such as multi-way branch can be reconstructed as needed; see +// ssautil.Switches() for an example. +// +// To construct an SSA-form program, call ssautil.CreateProgram on a +// loader.Program, a set of type-checked packages created from +// parsed Go source files. The resulting ssa.Program contains all the +// packages and their members, but SSA code is not created for +// function bodies until a subsequent call to (*Package).Build. +// +// The builder initially builds a naive SSA form in which all local +// variables are addresses of stack locations with explicit loads and +// stores. Registerisation of eligible locals and φ-node insertion +// using dominance and dataflow are then performed as a second pass +// called "lifting" to improve the accuracy and performance of +// subsequent analyses; this pass can be skipped by setting the +// NaiveForm builder flag. +// +// The primary interfaces of this package are: +// +// - Member: a named member of a Go package. +// - Value: an expression that yields a value. +// - Instruction: a statement that consumes values and performs computation. +// - Node: a Value or Instruction (emphasizing its membership in the SSA value graph) +// +// A computation that yields a result implements both the Value and +// Instruction interfaces. The following table shows for each +// concrete type which of these interfaces it implements. +// +// Value? Instruction? Member? +// *Alloc ✔ ✔ +// *BinOp ✔ ✔ +// *Builtin ✔ +// *Call ✔ ✔ +// *ChangeInterface ✔ ✔ +// *ChangeType ✔ ✔ +// *Const ✔ +// *Convert ✔ ✔ +// *DebugRef ✔ +// *Defer ✔ +// *Extract ✔ ✔ +// *Field ✔ ✔ +// *FieldAddr ✔ ✔ +// *FreeVar ✔ +// *Function ✔ ✔ (func) +// *Global ✔ ✔ (var) +// *Go ✔ +// *If ✔ +// *Index ✔ ✔ +// *IndexAddr ✔ ✔ +// *Jump ✔ +// *Lookup ✔ ✔ +// *MakeChan ✔ ✔ +// *MakeClosure ✔ ✔ +// *MakeInterface ✔ ✔ +// *MakeMap ✔ ✔ +// *MakeSlice ✔ ✔ +// *MapUpdate ✔ +// *NamedConst ✔ (const) +// *Next ✔ ✔ +// *Panic ✔ +// *Parameter ✔ +// *Phi ✔ ✔ +// *Range ✔ ✔ +// *Return ✔ +// *RunDefers ✔ +// *Select ✔ ✔ +// *Send ✔ +// *Slice ✔ ✔ +// *Store ✔ +// *Type ✔ (type) +// *TypeAssert ✔ ✔ +// *UnOp ✔ ✔ +// +// Other key types in this package include: Program, Package, Function +// and BasicBlock. +// +// The program representation constructed by this package is fully +// resolved internally, i.e. it does not rely on the names of Values, +// Packages, Functions, Types or BasicBlocks for the correct +// interpretation of the program. Only the identities of objects and +// the topology of the SSA and type graphs are semantically +// significant. (There is one exception: Ids, used to identify field +// and method names, contain strings.) Avoidance of name-based +// operations simplifies the implementation of subsequent passes and +// can make them very efficient. Many objects are nonetheless named +// to aid in debugging, but it is not essential that the names be +// either accurate or unambiguous. The public API exposes a number of +// name-based maps for client convenience. +// +// The ssa/ssautil package provides various utilities that depend only +// on the public API of this package. +// +// TODO(adonovan): Consider the exceptional control-flow implications +// of defer and recover(). +// +// TODO(adonovan): write a how-to document for all the various cases +// of trying to determine corresponding elements across the four +// domains of source locations, ast.Nodes, types.Objects, +// ssa.Values/Instructions. +// +package ssa // import "golang.org/x/tools/go/ssa" diff --git a/vendor/golang.org/x/tools/go/ssa/dom.go b/vendor/golang.org/x/tools/go/ssa/dom.go new file mode 100644 index 0000000..12ef430 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/dom.go @@ -0,0 +1,341 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines algorithms related to dominance. + +// Dominator tree construction ---------------------------------------- +// +// We use the algorithm described in Lengauer & Tarjan. 1979. A fast +// algorithm for finding dominators in a flowgraph. +// http://doi.acm.org/10.1145/357062.357071 +// +// We also apply the optimizations to SLT described in Georgiadis et +// al, Finding Dominators in Practice, JGAA 2006, +// http://jgaa.info/accepted/2006/GeorgiadisTarjanWerneck2006.10.1.pdf +// to avoid the need for buckets of size > 1. + +import ( + "bytes" + "fmt" + "math/big" + "os" + "sort" +) + +// Idom returns the block that immediately dominates b: +// its parent in the dominator tree, if any. +// Neither the entry node (b.Index==0) nor recover node +// (b==b.Parent().Recover()) have a parent. +// +func (b *BasicBlock) Idom() *BasicBlock { return b.dom.idom } + +// Dominees returns the list of blocks that b immediately dominates: +// its children in the dominator tree. +// +func (b *BasicBlock) Dominees() []*BasicBlock { return b.dom.children } + +// Dominates reports whether b dominates c. +func (b *BasicBlock) Dominates(c *BasicBlock) bool { + return b.dom.pre <= c.dom.pre && c.dom.post <= b.dom.post +} + +type byDomPreorder []*BasicBlock + +func (a byDomPreorder) Len() int { return len(a) } +func (a byDomPreorder) Swap(i, j int) { a[i], a[j] = a[j], a[i] } +func (a byDomPreorder) Less(i, j int) bool { return a[i].dom.pre < a[j].dom.pre } + +// DomPreorder returns a new slice containing the blocks of f in +// dominator tree preorder. +// +func (f *Function) DomPreorder() []*BasicBlock { + n := len(f.Blocks) + order := make(byDomPreorder, n, n) + copy(order, f.Blocks) + sort.Sort(order) + return order +} + +// domInfo contains a BasicBlock's dominance information. +type domInfo struct { + idom *BasicBlock // immediate dominator (parent in domtree) + children []*BasicBlock // nodes immediately dominated by this one + pre, post int32 // pre- and post-order numbering within domtree +} + +// ltState holds the working state for Lengauer-Tarjan algorithm +// (during which domInfo.pre is repurposed for CFG DFS preorder number). +type ltState struct { + // Each slice is indexed by b.Index. + sdom []*BasicBlock // b's semidominator + parent []*BasicBlock // b's parent in DFS traversal of CFG + ancestor []*BasicBlock // b's ancestor with least sdom +} + +// dfs implements the depth-first search part of the LT algorithm. +func (lt *ltState) dfs(v *BasicBlock, i int32, preorder []*BasicBlock) int32 { + preorder[i] = v + v.dom.pre = i // For now: DFS preorder of spanning tree of CFG + i++ + lt.sdom[v.Index] = v + lt.link(nil, v) + for _, w := range v.Succs { + if lt.sdom[w.Index] == nil { + lt.parent[w.Index] = v + i = lt.dfs(w, i, preorder) + } + } + return i +} + +// eval implements the EVAL part of the LT algorithm. +func (lt *ltState) eval(v *BasicBlock) *BasicBlock { + // TODO(adonovan): opt: do path compression per simple LT. + u := v + for ; lt.ancestor[v.Index] != nil; v = lt.ancestor[v.Index] { + if lt.sdom[v.Index].dom.pre < lt.sdom[u.Index].dom.pre { + u = v + } + } + return u +} + +// link implements the LINK part of the LT algorithm. +func (lt *ltState) link(v, w *BasicBlock) { + lt.ancestor[w.Index] = v +} + +// buildDomTree computes the dominator tree of f using the LT algorithm. +// Precondition: all blocks are reachable (e.g. optimizeBlocks has been run). +// +func buildDomTree(f *Function) { + // The step numbers refer to the original LT paper; the + // reordering is due to Georgiadis. + + // Clear any previous domInfo. + for _, b := range f.Blocks { + b.dom = domInfo{} + } + + n := len(f.Blocks) + // Allocate space for 5 contiguous [n]*BasicBlock arrays: + // sdom, parent, ancestor, preorder, buckets. + space := make([]*BasicBlock, 5*n, 5*n) + lt := ltState{ + sdom: space[0:n], + parent: space[n : 2*n], + ancestor: space[2*n : 3*n], + } + + // Step 1. Number vertices by depth-first preorder. + preorder := space[3*n : 4*n] + root := f.Blocks[0] + prenum := lt.dfs(root, 0, preorder) + recover := f.Recover + if recover != nil { + lt.dfs(recover, prenum, preorder) + } + + buckets := space[4*n : 5*n] + copy(buckets, preorder) + + // In reverse preorder... + for i := int32(n) - 1; i > 0; i-- { + w := preorder[i] + + // Step 3. Implicitly define the immediate dominator of each node. + for v := buckets[i]; v != w; v = buckets[v.dom.pre] { + u := lt.eval(v) + if lt.sdom[u.Index].dom.pre < i { + v.dom.idom = u + } else { + v.dom.idom = w + } + } + + // Step 2. Compute the semidominators of all nodes. + lt.sdom[w.Index] = lt.parent[w.Index] + for _, v := range w.Preds { + u := lt.eval(v) + if lt.sdom[u.Index].dom.pre < lt.sdom[w.Index].dom.pre { + lt.sdom[w.Index] = lt.sdom[u.Index] + } + } + + lt.link(lt.parent[w.Index], w) + + if lt.parent[w.Index] == lt.sdom[w.Index] { + w.dom.idom = lt.parent[w.Index] + } else { + buckets[i] = buckets[lt.sdom[w.Index].dom.pre] + buckets[lt.sdom[w.Index].dom.pre] = w + } + } + + // The final 'Step 3' is now outside the loop. + for v := buckets[0]; v != root; v = buckets[v.dom.pre] { + v.dom.idom = root + } + + // Step 4. Explicitly define the immediate dominator of each + // node, in preorder. + for _, w := range preorder[1:] { + if w == root || w == recover { + w.dom.idom = nil + } else { + if w.dom.idom != lt.sdom[w.Index] { + w.dom.idom = w.dom.idom.dom.idom + } + // Calculate Children relation as inverse of Idom. + w.dom.idom.dom.children = append(w.dom.idom.dom.children, w) + } + } + + pre, post := numberDomTree(root, 0, 0) + if recover != nil { + numberDomTree(recover, pre, post) + } + + // printDomTreeDot(os.Stderr, f) // debugging + // printDomTreeText(os.Stderr, root, 0) // debugging + + if f.Prog.mode&SanityCheckFunctions != 0 { + sanityCheckDomTree(f) + } +} + +// numberDomTree sets the pre- and post-order numbers of a depth-first +// traversal of the dominator tree rooted at v. These are used to +// answer dominance queries in constant time. +// +func numberDomTree(v *BasicBlock, pre, post int32) (int32, int32) { + v.dom.pre = pre + pre++ + for _, child := range v.dom.children { + pre, post = numberDomTree(child, pre, post) + } + v.dom.post = post + post++ + return pre, post +} + +// Testing utilities ---------------------------------------- + +// sanityCheckDomTree checks the correctness of the dominator tree +// computed by the LT algorithm by comparing against the dominance +// relation computed by a naive Kildall-style forward dataflow +// analysis (Algorithm 10.16 from the "Dragon" book). +// +func sanityCheckDomTree(f *Function) { + n := len(f.Blocks) + + // D[i] is the set of blocks that dominate f.Blocks[i], + // represented as a bit-set of block indices. + D := make([]big.Int, n) + + one := big.NewInt(1) + + // all is the set of all blocks; constant. + var all big.Int + all.Set(one).Lsh(&all, uint(n)).Sub(&all, one) + + // Initialization. + for i, b := range f.Blocks { + if i == 0 || b == f.Recover { + // A root is dominated only by itself. + D[i].SetBit(&D[0], 0, 1) + } else { + // All other blocks are (initially) dominated + // by every block. + D[i].Set(&all) + } + } + + // Iteration until fixed point. + for changed := true; changed; { + changed = false + for i, b := range f.Blocks { + if i == 0 || b == f.Recover { + continue + } + // Compute intersection across predecessors. + var x big.Int + x.Set(&all) + for _, pred := range b.Preds { + x.And(&x, &D[pred.Index]) + } + x.SetBit(&x, i, 1) // a block always dominates itself. + if D[i].Cmp(&x) != 0 { + D[i].Set(&x) + changed = true + } + } + } + + // Check the entire relation. O(n^2). + // The Recover block (if any) must be treated specially so we skip it. + ok := true + for i := 0; i < n; i++ { + for j := 0; j < n; j++ { + b, c := f.Blocks[i], f.Blocks[j] + if c == f.Recover { + continue + } + actual := b.Dominates(c) + expected := D[j].Bit(i) == 1 + if actual != expected { + fmt.Fprintf(os.Stderr, "dominates(%s, %s)==%t, want %t\n", b, c, actual, expected) + ok = false + } + } + } + + preorder := f.DomPreorder() + for _, b := range f.Blocks { + if got := preorder[b.dom.pre]; got != b { + fmt.Fprintf(os.Stderr, "preorder[%d]==%s, want %s\n", b.dom.pre, got, b) + ok = false + } + } + + if !ok { + panic("sanityCheckDomTree failed for " + f.String()) + } + +} + +// Printing functions ---------------------------------------- + +// printDomTree prints the dominator tree as text, using indentation. +func printDomTreeText(buf *bytes.Buffer, v *BasicBlock, indent int) { + fmt.Fprintf(buf, "%*s%s\n", 4*indent, "", v) + for _, child := range v.dom.children { + printDomTreeText(buf, child, indent+1) + } +} + +// printDomTreeDot prints the dominator tree of f in AT&T GraphViz +// (.dot) format. +func printDomTreeDot(buf *bytes.Buffer, f *Function) { + fmt.Fprintln(buf, "//", f) + fmt.Fprintln(buf, "digraph domtree {") + for i, b := range f.Blocks { + v := b.dom + fmt.Fprintf(buf, "\tn%d [label=\"%s (%d, %d)\",shape=\"rectangle\"];\n", v.pre, b, v.pre, v.post) + // TODO(adonovan): improve appearance of edges + // belonging to both dominator tree and CFG. + + // Dominator tree edge. + if i != 0 { + fmt.Fprintf(buf, "\tn%d -> n%d [style=\"solid\",weight=100];\n", v.idom.dom.pre, v.pre) + } + // CFG edges. + for _, pred := range b.Preds { + fmt.Fprintf(buf, "\tn%d -> n%d [style=\"dotted\",weight=0];\n", pred.dom.pre, v.pre) + } + } + fmt.Fprintln(buf, "}") +} diff --git a/vendor/golang.org/x/tools/go/ssa/emit.go b/vendor/golang.org/x/tools/go/ssa/emit.go new file mode 100644 index 0000000..1036988 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/emit.go @@ -0,0 +1,468 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// Helpers for emitting SSA instructions. + +import ( + "fmt" + "go/ast" + "go/token" + "go/types" +) + +// emitNew emits to f a new (heap Alloc) instruction allocating an +// object of type typ. pos is the optional source location. +// +func emitNew(f *Function, typ types.Type, pos token.Pos) *Alloc { + v := &Alloc{Heap: true} + v.setType(types.NewPointer(typ)) + v.setPos(pos) + f.emit(v) + return v +} + +// emitLoad emits to f an instruction to load the address addr into a +// new temporary, and returns the value so defined. +// +func emitLoad(f *Function, addr Value) *UnOp { + v := &UnOp{Op: token.MUL, X: addr} + v.setType(deref(addr.Type())) + f.emit(v) + return v +} + +// emitDebugRef emits to f a DebugRef pseudo-instruction associating +// expression e with value v. +// +func emitDebugRef(f *Function, e ast.Expr, v Value, isAddr bool) { + if !f.debugInfo() { + return // debugging not enabled + } + if v == nil || e == nil { + panic("nil") + } + var obj types.Object + e = unparen(e) + if id, ok := e.(*ast.Ident); ok { + if isBlankIdent(id) { + return + } + obj = f.Pkg.objectOf(id) + switch obj.(type) { + case *types.Nil, *types.Const, *types.Builtin: + return + } + } + f.emit(&DebugRef{ + X: v, + Expr: e, + IsAddr: isAddr, + object: obj, + }) +} + +// emitArith emits to f code to compute the binary operation op(x, y) +// where op is an eager shift, logical or arithmetic operation. +// (Use emitCompare() for comparisons and Builder.logicalBinop() for +// non-eager operations.) +// +func emitArith(f *Function, op token.Token, x, y Value, t types.Type, pos token.Pos) Value { + switch op { + case token.SHL, token.SHR: + x = emitConv(f, x, t) + // y may be signed or an 'untyped' constant. + // TODO(adonovan): whence signed values? + if b, ok := y.Type().Underlying().(*types.Basic); ok && b.Info()&types.IsUnsigned == 0 { + y = emitConv(f, y, types.Typ[types.Uint64]) + } + + case token.ADD, token.SUB, token.MUL, token.QUO, token.REM, token.AND, token.OR, token.XOR, token.AND_NOT: + x = emitConv(f, x, t) + y = emitConv(f, y, t) + + default: + panic("illegal op in emitArith: " + op.String()) + + } + v := &BinOp{ + Op: op, + X: x, + Y: y, + } + v.setPos(pos) + v.setType(t) + return f.emit(v) +} + +// emitCompare emits to f code compute the boolean result of +// comparison comparison 'x op y'. +// +func emitCompare(f *Function, op token.Token, x, y Value, pos token.Pos) Value { + xt := x.Type().Underlying() + yt := y.Type().Underlying() + + // Special case to optimise a tagless SwitchStmt so that + // these are equivalent + // switch { case e: ...} + // switch true { case e: ... } + // if e==true { ... } + // even in the case when e's type is an interface. + // TODO(adonovan): opt: generalise to x==true, false!=y, etc. + if x == vTrue && op == token.EQL { + if yt, ok := yt.(*types.Basic); ok && yt.Info()&types.IsBoolean != 0 { + return y + } + } + + if types.Identical(xt, yt) { + // no conversion necessary + } else if _, ok := xt.(*types.Interface); ok { + y = emitConv(f, y, x.Type()) + } else if _, ok := yt.(*types.Interface); ok { + x = emitConv(f, x, y.Type()) + } else if _, ok := x.(*Const); ok { + x = emitConv(f, x, y.Type()) + } else if _, ok := y.(*Const); ok { + y = emitConv(f, y, x.Type()) + } else { + // other cases, e.g. channels. No-op. + } + + v := &BinOp{ + Op: op, + X: x, + Y: y, + } + v.setPos(pos) + v.setType(tBool) + return f.emit(v) +} + +// isValuePreserving returns true if a conversion from ut_src to +// ut_dst is value-preserving, i.e. just a change of type. +// Precondition: neither argument is a named type. +// +func isValuePreserving(ut_src, ut_dst types.Type) bool { + // Identical underlying types? + if structTypesIdentical(ut_dst, ut_src) { + return true + } + + switch ut_dst.(type) { + case *types.Chan: + // Conversion between channel types? + _, ok := ut_src.(*types.Chan) + return ok + + case *types.Pointer: + // Conversion between pointers with identical base types? + _, ok := ut_src.(*types.Pointer) + return ok + } + return false +} + +// emitConv emits to f code to convert Value val to exactly type typ, +// and returns the converted value. Implicit conversions are required +// by language assignability rules in assignments, parameter passing, +// etc. Conversions cannot fail dynamically. +// +func emitConv(f *Function, val Value, typ types.Type) Value { + t_src := val.Type() + + // Identical types? Conversion is a no-op. + if types.Identical(t_src, typ) { + return val + } + + ut_dst := typ.Underlying() + ut_src := t_src.Underlying() + + // Just a change of type, but not value or representation? + if isValuePreserving(ut_src, ut_dst) { + c := &ChangeType{X: val} + c.setType(typ) + return f.emit(c) + } + + // Conversion to, or construction of a value of, an interface type? + if _, ok := ut_dst.(*types.Interface); ok { + // Assignment from one interface type to another? + if _, ok := ut_src.(*types.Interface); ok { + c := &ChangeInterface{X: val} + c.setType(typ) + return f.emit(c) + } + + // Untyped nil constant? Return interface-typed nil constant. + if ut_src == tUntypedNil { + return nilConst(typ) + } + + // Convert (non-nil) "untyped" literals to their default type. + if t, ok := ut_src.(*types.Basic); ok && t.Info()&types.IsUntyped != 0 { + val = emitConv(f, val, DefaultType(ut_src)) + } + + f.Pkg.Prog.needMethodsOf(val.Type()) + mi := &MakeInterface{X: val} + mi.setType(typ) + return f.emit(mi) + } + + // Conversion of a compile-time constant value? + if c, ok := val.(*Const); ok { + if _, ok := ut_dst.(*types.Basic); ok || c.IsNil() { + // Conversion of a compile-time constant to + // another constant type results in a new + // constant of the destination type and + // (initially) the same abstract value. + // We don't truncate the value yet. + return NewConst(c.Value, typ) + } + + // We're converting from constant to non-constant type, + // e.g. string -> []byte/[]rune. + } + + // A representation-changing conversion? + // At least one of {ut_src,ut_dst} must be *Basic. + // (The other may be []byte or []rune.) + _, ok1 := ut_src.(*types.Basic) + _, ok2 := ut_dst.(*types.Basic) + if ok1 || ok2 { + c := &Convert{X: val} + c.setType(typ) + return f.emit(c) + } + + panic(fmt.Sprintf("in %s: cannot convert %s (%s) to %s", f, val, val.Type(), typ)) +} + +// emitStore emits to f an instruction to store value val at location +// addr, applying implicit conversions as required by assignability rules. +// +func emitStore(f *Function, addr, val Value, pos token.Pos) *Store { + s := &Store{ + Addr: addr, + Val: emitConv(f, val, deref(addr.Type())), + pos: pos, + } + f.emit(s) + return s +} + +// emitJump emits to f a jump to target, and updates the control-flow graph. +// Postcondition: f.currentBlock is nil. +// +func emitJump(f *Function, target *BasicBlock) { + b := f.currentBlock + b.emit(new(Jump)) + addEdge(b, target) + f.currentBlock = nil +} + +// emitIf emits to f a conditional jump to tblock or fblock based on +// cond, and updates the control-flow graph. +// Postcondition: f.currentBlock is nil. +// +func emitIf(f *Function, cond Value, tblock, fblock *BasicBlock) { + b := f.currentBlock + b.emit(&If{Cond: cond}) + addEdge(b, tblock) + addEdge(b, fblock) + f.currentBlock = nil +} + +// emitExtract emits to f an instruction to extract the index'th +// component of tuple. It returns the extracted value. +// +func emitExtract(f *Function, tuple Value, index int) Value { + e := &Extract{Tuple: tuple, Index: index} + e.setType(tuple.Type().(*types.Tuple).At(index).Type()) + return f.emit(e) +} + +// emitTypeAssert emits to f a type assertion value := x.(t) and +// returns the value. x.Type() must be an interface. +// +func emitTypeAssert(f *Function, x Value, t types.Type, pos token.Pos) Value { + a := &TypeAssert{X: x, AssertedType: t} + a.setPos(pos) + a.setType(t) + return f.emit(a) +} + +// emitTypeTest emits to f a type test value,ok := x.(t) and returns +// a (value, ok) tuple. x.Type() must be an interface. +// +func emitTypeTest(f *Function, x Value, t types.Type, pos token.Pos) Value { + a := &TypeAssert{ + X: x, + AssertedType: t, + CommaOk: true, + } + a.setPos(pos) + a.setType(types.NewTuple( + newVar("value", t), + varOk, + )) + return f.emit(a) +} + +// emitTailCall emits to f a function call in tail position. The +// caller is responsible for all fields of 'call' except its type. +// Intended for wrapper methods. +// Precondition: f does/will not use deferred procedure calls. +// Postcondition: f.currentBlock is nil. +// +func emitTailCall(f *Function, call *Call) { + tresults := f.Signature.Results() + nr := tresults.Len() + if nr == 1 { + call.typ = tresults.At(0).Type() + } else { + call.typ = tresults + } + tuple := f.emit(call) + var ret Return + switch nr { + case 0: + // no-op + case 1: + ret.Results = []Value{tuple} + default: + for i := 0; i < nr; i++ { + v := emitExtract(f, tuple, i) + // TODO(adonovan): in principle, this is required: + // v = emitConv(f, o.Type, f.Signature.Results[i].Type) + // but in practice emitTailCall is only used when + // the types exactly match. + ret.Results = append(ret.Results, v) + } + } + f.emit(&ret) + f.currentBlock = nil +} + +// emitImplicitSelections emits to f code to apply the sequence of +// implicit field selections specified by indices to base value v, and +// returns the selected value. +// +// If v is the address of a struct, the result will be the address of +// a field; if it is the value of a struct, the result will be the +// value of a field. +// +func emitImplicitSelections(f *Function, v Value, indices []int) Value { + for _, index := range indices { + fld := deref(v.Type()).Underlying().(*types.Struct).Field(index) + + if isPointer(v.Type()) { + instr := &FieldAddr{ + X: v, + Field: index, + } + instr.setType(types.NewPointer(fld.Type())) + v = f.emit(instr) + // Load the field's value iff indirectly embedded. + if isPointer(fld.Type()) { + v = emitLoad(f, v) + } + } else { + instr := &Field{ + X: v, + Field: index, + } + instr.setType(fld.Type()) + v = f.emit(instr) + } + } + return v +} + +// emitFieldSelection emits to f code to select the index'th field of v. +// +// If wantAddr, the input must be a pointer-to-struct and the result +// will be the field's address; otherwise the result will be the +// field's value. +// Ident id is used for position and debug info. +// +func emitFieldSelection(f *Function, v Value, index int, wantAddr bool, id *ast.Ident) Value { + fld := deref(v.Type()).Underlying().(*types.Struct).Field(index) + if isPointer(v.Type()) { + instr := &FieldAddr{ + X: v, + Field: index, + } + instr.setPos(id.Pos()) + instr.setType(types.NewPointer(fld.Type())) + v = f.emit(instr) + // Load the field's value iff we don't want its address. + if !wantAddr { + v = emitLoad(f, v) + } + } else { + instr := &Field{ + X: v, + Field: index, + } + instr.setPos(id.Pos()) + instr.setType(fld.Type()) + v = f.emit(instr) + } + emitDebugRef(f, id, v, wantAddr) + return v +} + +// zeroValue emits to f code to produce a zero value of type t, +// and returns it. +// +func zeroValue(f *Function, t types.Type) Value { + switch t.Underlying().(type) { + case *types.Struct, *types.Array: + return emitLoad(f, f.addLocal(t, token.NoPos)) + default: + return zeroConst(t) + } +} + +// createRecoverBlock emits to f a block of code to return after a +// recovered panic, and sets f.Recover to it. +// +// If f's result parameters are named, the code loads and returns +// their current values, otherwise it returns the zero values of their +// type. +// +// Idempotent. +// +func createRecoverBlock(f *Function) { + if f.Recover != nil { + return // already created + } + saved := f.currentBlock + + f.Recover = f.newBasicBlock("recover") + f.currentBlock = f.Recover + + var results []Value + if f.namedResults != nil { + // Reload NRPs to form value tuple. + for _, r := range f.namedResults { + results = append(results, emitLoad(f, r)) + } + } else { + R := f.Signature.Results() + for i, n := 0, R.Len(); i < n; i++ { + T := R.At(i).Type() + + // Return zero value of each result type. + results = append(results, zeroValue(f, T)) + } + } + f.emit(&Return{Results: results}) + + f.currentBlock = saved +} diff --git a/vendor/golang.org/x/tools/go/ssa/example_test.go b/vendor/golang.org/x/tools/go/ssa/example_test.go new file mode 100644 index 0000000..31fa561 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/example_test.go @@ -0,0 +1,138 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa_test + +import ( + "fmt" + "go/ast" + "go/importer" + "go/parser" + "go/token" + "go/types" + "os" + + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +const hello = ` +package main + +import "fmt" + +const message = "Hello, World!" + +func main() { + fmt.Println(message) +} +` + +// This program demonstrates how to run the SSA builder on a single +// package of one or more already-parsed files. Its dependencies are +// loaded from compiler export data. This is what you'd typically use +// for a compiler; it does not depend on golang.org/x/tools/go/loader. +// +// It shows the printed representation of packages, functions, and +// instructions. Within the function listing, the name of each +// BasicBlock such as ".0.entry" is printed left-aligned, followed by +// the block's Instructions. +// +// For each instruction that defines an SSA virtual register +// (i.e. implements Value), the type of that value is shown in the +// right column. +// +// Build and run the ssadump.go program if you want a standalone tool +// with similar functionality. It is located at +// golang.org/x/tools/cmd/ssadump. +// +func ExampleBuildPackage() { + // Parse the source files. + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "hello.go", hello, parser.ParseComments) + if err != nil { + fmt.Print(err) // parse error + return + } + files := []*ast.File{f} + + // Create the type-checker's package. + pkg := types.NewPackage("hello", "") + + // Type-check the package, load dependencies. + // Create and build the SSA program. + hello, _, err := ssautil.BuildPackage( + &types.Config{Importer: importer.Default()}, fset, pkg, files, ssa.SanityCheckFunctions) + if err != nil { + fmt.Print(err) // type error in some package + return + } + + // Print out the package. + hello.WriteTo(os.Stdout) + + // Print out the package-level functions. + hello.Func("init").WriteTo(os.Stdout) + hello.Func("main").WriteTo(os.Stdout) + + // Output: + // + // package hello: + // func init func() + // var init$guard bool + // func main func() + // const message message = "Hello, World!":untyped string + // + // # Name: hello.init + // # Package: hello + // # Synthetic: package initializer + // func init(): + // 0: entry P:0 S:2 + // t0 = *init$guard bool + // if t0 goto 2 else 1 + // 1: init.start P:1 S:1 + // *init$guard = true:bool + // t1 = fmt.init() () + // jump 2 + // 2: init.done P:2 S:0 + // return + // + // # Name: hello.main + // # Package: hello + // # Location: hello.go:8:6 + // func main(): + // 0: entry P:0 S:0 + // t0 = new [1]interface{} (varargs) *[1]interface{} + // t1 = &t0[0:int] *interface{} + // t2 = make interface{} <- string ("Hello, World!":string) interface{} + // *t1 = t2 + // t3 = slice t0[:] []interface{} + // t4 = fmt.Println(t3...) (n int, err error) + // return +} + +// This program shows how to load a main package (cmd/cover) and all its +// dependencies from source, using the loader, and then build SSA code +// for the entire program. This is what you'd typically use for a +// whole-program analysis. +// +func ExampleLoadProgram() { + // Load cmd/cover and its dependencies. + var conf loader.Config + conf.Import("cmd/cover") + lprog, err := conf.Load() + if err != nil { + fmt.Print(err) // type error in some package + return + } + + // Create SSA-form program representation. + prog := ssautil.CreateProgram(lprog, ssa.SanityCheckFunctions) + + // Build SSA code for the entire cmd/cover program. + prog.Build() + + // Output: +} diff --git a/vendor/golang.org/x/tools/go/ssa/func.go b/vendor/golang.org/x/tools/go/ssa/func.go new file mode 100644 index 0000000..b21ff4e --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/func.go @@ -0,0 +1,689 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the Function and BasicBlock types. + +import ( + "bytes" + "fmt" + "go/ast" + "go/token" + "go/types" + "io" + "os" + "strings" +) + +// addEdge adds a control-flow graph edge from from to to. +func addEdge(from, to *BasicBlock) { + from.Succs = append(from.Succs, to) + to.Preds = append(to.Preds, from) +} + +// Parent returns the function that contains block b. +func (b *BasicBlock) Parent() *Function { return b.parent } + +// String returns a human-readable label of this block. +// It is not guaranteed unique within the function. +// +func (b *BasicBlock) String() string { + return fmt.Sprintf("%d", b.Index) +} + +// emit appends an instruction to the current basic block. +// If the instruction defines a Value, it is returned. +// +func (b *BasicBlock) emit(i Instruction) Value { + i.setBlock(b) + b.Instrs = append(b.Instrs, i) + v, _ := i.(Value) + return v +} + +// predIndex returns the i such that b.Preds[i] == c or panics if +// there is none. +func (b *BasicBlock) predIndex(c *BasicBlock) int { + for i, pred := range b.Preds { + if pred == c { + return i + } + } + panic(fmt.Sprintf("no edge %s -> %s", c, b)) +} + +// hasPhi returns true if b.Instrs contains φ-nodes. +func (b *BasicBlock) hasPhi() bool { + _, ok := b.Instrs[0].(*Phi) + return ok +} + +// phis returns the prefix of b.Instrs containing all the block's φ-nodes. +func (b *BasicBlock) phis() []Instruction { + for i, instr := range b.Instrs { + if _, ok := instr.(*Phi); !ok { + return b.Instrs[:i] + } + } + return nil // unreachable in well-formed blocks +} + +// replacePred replaces all occurrences of p in b's predecessor list with q. +// Ordinarily there should be at most one. +// +func (b *BasicBlock) replacePred(p, q *BasicBlock) { + for i, pred := range b.Preds { + if pred == p { + b.Preds[i] = q + } + } +} + +// replaceSucc replaces all occurrences of p in b's successor list with q. +// Ordinarily there should be at most one. +// +func (b *BasicBlock) replaceSucc(p, q *BasicBlock) { + for i, succ := range b.Succs { + if succ == p { + b.Succs[i] = q + } + } +} + +// removePred removes all occurrences of p in b's +// predecessor list and φ-nodes. +// Ordinarily there should be at most one. +// +func (b *BasicBlock) removePred(p *BasicBlock) { + phis := b.phis() + + // We must preserve edge order for φ-nodes. + j := 0 + for i, pred := range b.Preds { + if pred != p { + b.Preds[j] = b.Preds[i] + // Strike out φ-edge too. + for _, instr := range phis { + phi := instr.(*Phi) + phi.Edges[j] = phi.Edges[i] + } + j++ + } + } + // Nil out b.Preds[j:] and φ-edges[j:] to aid GC. + for i := j; i < len(b.Preds); i++ { + b.Preds[i] = nil + for _, instr := range phis { + instr.(*Phi).Edges[i] = nil + } + } + b.Preds = b.Preds[:j] + for _, instr := range phis { + phi := instr.(*Phi) + phi.Edges = phi.Edges[:j] + } +} + +// Destinations associated with unlabelled for/switch/select stmts. +// We push/pop one of these as we enter/leave each construct and for +// each BranchStmt we scan for the innermost target of the right type. +// +type targets struct { + tail *targets // rest of stack + _break *BasicBlock + _continue *BasicBlock + _fallthrough *BasicBlock +} + +// Destinations associated with a labelled block. +// We populate these as labels are encountered in forward gotos or +// labelled statements. +// +type lblock struct { + _goto *BasicBlock + _break *BasicBlock + _continue *BasicBlock +} + +// labelledBlock returns the branch target associated with the +// specified label, creating it if needed. +// +func (f *Function) labelledBlock(label *ast.Ident) *lblock { + lb := f.lblocks[label.Obj] + if lb == nil { + lb = &lblock{_goto: f.newBasicBlock(label.Name)} + if f.lblocks == nil { + f.lblocks = make(map[*ast.Object]*lblock) + } + f.lblocks[label.Obj] = lb + } + return lb +} + +// addParam adds a (non-escaping) parameter to f.Params of the +// specified name, type and source position. +// +func (f *Function) addParam(name string, typ types.Type, pos token.Pos) *Parameter { + v := &Parameter{ + name: name, + typ: typ, + pos: pos, + parent: f, + } + f.Params = append(f.Params, v) + return v +} + +func (f *Function) addParamObj(obj types.Object) *Parameter { + name := obj.Name() + if name == "" { + name = fmt.Sprintf("arg%d", len(f.Params)) + } + param := f.addParam(name, obj.Type(), obj.Pos()) + param.object = obj + return param +} + +// addSpilledParam declares a parameter that is pre-spilled to the +// stack; the function body will load/store the spilled location. +// Subsequent lifting will eliminate spills where possible. +// +func (f *Function) addSpilledParam(obj types.Object) { + param := f.addParamObj(obj) + spill := &Alloc{Comment: obj.Name()} + spill.setType(types.NewPointer(obj.Type())) + spill.setPos(obj.Pos()) + f.objects[obj] = spill + f.Locals = append(f.Locals, spill) + f.emit(spill) + f.emit(&Store{Addr: spill, Val: param}) +} + +// startBody initializes the function prior to generating SSA code for its body. +// Precondition: f.Type() already set. +// +func (f *Function) startBody() { + f.currentBlock = f.newBasicBlock("entry") + f.objects = make(map[types.Object]Value) // needed for some synthetics, e.g. init +} + +// createSyntacticParams populates f.Params and generates code (spills +// and named result locals) for all the parameters declared in the +// syntax. In addition it populates the f.objects mapping. +// +// Preconditions: +// f.startBody() was called. +// Postcondition: +// len(f.Params) == len(f.Signature.Params) + (f.Signature.Recv() ? 1 : 0) +// +func (f *Function) createSyntacticParams(recv *ast.FieldList, functype *ast.FuncType) { + // Receiver (at most one inner iteration). + if recv != nil { + for _, field := range recv.List { + for _, n := range field.Names { + f.addSpilledParam(f.Pkg.info.Defs[n]) + } + // Anonymous receiver? No need to spill. + if field.Names == nil { + f.addParamObj(f.Signature.Recv()) + } + } + } + + // Parameters. + if functype.Params != nil { + n := len(f.Params) // 1 if has recv, 0 otherwise + for _, field := range functype.Params.List { + for _, n := range field.Names { + f.addSpilledParam(f.Pkg.info.Defs[n]) + } + // Anonymous parameter? No need to spill. + if field.Names == nil { + f.addParamObj(f.Signature.Params().At(len(f.Params) - n)) + } + } + } + + // Named results. + if functype.Results != nil { + for _, field := range functype.Results.List { + // Implicit "var" decl of locals for named results. + for _, n := range field.Names { + f.namedResults = append(f.namedResults, f.addLocalForIdent(n)) + } + } + } +} + +// numberRegisters assigns numbers to all SSA registers +// (value-defining Instructions) in f, to aid debugging. +// (Non-Instruction Values are named at construction.) +// +func numberRegisters(f *Function) { + v := 0 + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + switch instr.(type) { + case Value: + instr.(interface { + setNum(int) + }).setNum(v) + v++ + } + } + } +} + +// buildReferrers populates the def/use information in all non-nil +// Value.Referrers slice. +// Precondition: all such slices are initially empty. +func buildReferrers(f *Function) { + var rands []*Value + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + rands = instr.Operands(rands[:0]) // recycle storage + for _, rand := range rands { + if r := *rand; r != nil { + if ref := r.Referrers(); ref != nil { + *ref = append(*ref, instr) + } + } + } + } + } +} + +// finishBody() finalizes the function after SSA code generation of its body. +func (f *Function) finishBody() { + f.objects = nil + f.currentBlock = nil + f.lblocks = nil + + // Don't pin the AST in memory (except in debug mode). + if n := f.syntax; n != nil && !f.debugInfo() { + f.syntax = extentNode{n.Pos(), n.End()} + } + + // Remove from f.Locals any Allocs that escape to the heap. + j := 0 + for _, l := range f.Locals { + if !l.Heap { + f.Locals[j] = l + j++ + } + } + // Nil out f.Locals[j:] to aid GC. + for i := j; i < len(f.Locals); i++ { + f.Locals[i] = nil + } + f.Locals = f.Locals[:j] + + optimizeBlocks(f) + + buildReferrers(f) + + buildDomTree(f) + + if f.Prog.mode&NaiveForm == 0 { + // For debugging pre-state of lifting pass: + // numberRegisters(f) + // f.WriteTo(os.Stderr) + lift(f) + } + + f.namedResults = nil // (used by lifting) + + numberRegisters(f) + + if f.Prog.mode&PrintFunctions != 0 { + printMu.Lock() + f.WriteTo(os.Stdout) + printMu.Unlock() + } + + if f.Prog.mode&SanityCheckFunctions != 0 { + mustSanityCheck(f, nil) + } +} + +// removeNilBlocks eliminates nils from f.Blocks and updates each +// BasicBlock.Index. Use this after any pass that may delete blocks. +// +func (f *Function) removeNilBlocks() { + j := 0 + for _, b := range f.Blocks { + if b != nil { + b.Index = j + f.Blocks[j] = b + j++ + } + } + // Nil out f.Blocks[j:] to aid GC. + for i := j; i < len(f.Blocks); i++ { + f.Blocks[i] = nil + } + f.Blocks = f.Blocks[:j] +} + +// SetDebugMode sets the debug mode for package pkg. If true, all its +// functions will include full debug info. This greatly increases the +// size of the instruction stream, and causes Functions to depend upon +// the ASTs, potentially keeping them live in memory for longer. +// +func (pkg *Package) SetDebugMode(debug bool) { + // TODO(adonovan): do we want ast.File granularity? + pkg.debug = debug +} + +// debugInfo reports whether debug info is wanted for this function. +func (f *Function) debugInfo() bool { + return f.Pkg != nil && f.Pkg.debug +} + +// addNamedLocal creates a local variable, adds it to function f and +// returns it. Its name and type are taken from obj. Subsequent +// calls to f.lookup(obj) will return the same local. +// +func (f *Function) addNamedLocal(obj types.Object) *Alloc { + l := f.addLocal(obj.Type(), obj.Pos()) + l.Comment = obj.Name() + f.objects[obj] = l + return l +} + +func (f *Function) addLocalForIdent(id *ast.Ident) *Alloc { + return f.addNamedLocal(f.Pkg.info.Defs[id]) +} + +// addLocal creates an anonymous local variable of type typ, adds it +// to function f and returns it. pos is the optional source location. +// +func (f *Function) addLocal(typ types.Type, pos token.Pos) *Alloc { + v := &Alloc{} + v.setType(types.NewPointer(typ)) + v.setPos(pos) + f.Locals = append(f.Locals, v) + f.emit(v) + return v +} + +// lookup returns the address of the named variable identified by obj +// that is local to function f or one of its enclosing functions. +// If escaping, the reference comes from a potentially escaping pointer +// expression and the referent must be heap-allocated. +// +func (f *Function) lookup(obj types.Object, escaping bool) Value { + if v, ok := f.objects[obj]; ok { + if alloc, ok := v.(*Alloc); ok && escaping { + alloc.Heap = true + } + return v // function-local var (address) + } + + // Definition must be in an enclosing function; + // plumb it through intervening closures. + if f.parent == nil { + panic("no ssa.Value for " + obj.String()) + } + outer := f.parent.lookup(obj, true) // escaping + v := &FreeVar{ + name: obj.Name(), + typ: outer.Type(), + pos: outer.Pos(), + outer: outer, + parent: f, + } + f.objects[obj] = v + f.FreeVars = append(f.FreeVars, v) + return v +} + +// emit emits the specified instruction to function f. +func (f *Function) emit(instr Instruction) Value { + return f.currentBlock.emit(instr) +} + +// RelString returns the full name of this function, qualified by +// package name, receiver type, etc. +// +// The specific formatting rules are not guaranteed and may change. +// +// Examples: +// "math.IsNaN" // a package-level function +// "(*bytes.Buffer).Bytes" // a declared method or a wrapper +// "(*bytes.Buffer).Bytes$thunk" // thunk (func wrapping method; receiver is param 0) +// "(*bytes.Buffer).Bytes$bound" // bound (func wrapping method; receiver supplied by closure) +// "main.main$1" // an anonymous function in main +// "main.init#1" // a declared init function +// "main.init" // the synthesized package initializer +// +// When these functions are referred to from within the same package +// (i.e. from == f.Pkg.Object), they are rendered without the package path. +// For example: "IsNaN", "(*Buffer).Bytes", etc. +// +// All non-synthetic functions have distinct package-qualified names. +// (But two methods may have the same name "(T).f" if one is a synthetic +// wrapper promoting a non-exported method "f" from another package; in +// that case, the strings are equal but the identifiers "f" are distinct.) +// +func (f *Function) RelString(from *types.Package) string { + // Anonymous? + if f.parent != nil { + // An anonymous function's Name() looks like "parentName$1", + // but its String() should include the type/package/etc. + parent := f.parent.RelString(from) + for i, anon := range f.parent.AnonFuncs { + if anon == f { + return fmt.Sprintf("%s$%d", parent, 1+i) + } + } + + return f.name // should never happen + } + + // Method (declared or wrapper)? + if recv := f.Signature.Recv(); recv != nil { + return f.relMethod(from, recv.Type()) + } + + // Thunk? + if f.method != nil { + return f.relMethod(from, f.method.Recv()) + } + + // Bound? + if len(f.FreeVars) == 1 && strings.HasSuffix(f.name, "$bound") { + return f.relMethod(from, f.FreeVars[0].Type()) + } + + // Package-level function? + // Prefix with package name for cross-package references only. + if p := f.pkg(); p != nil && p != from { + return fmt.Sprintf("%s.%s", p.Path(), f.name) + } + + // Unknown. + return f.name +} + +func (f *Function) relMethod(from *types.Package, recv types.Type) string { + return fmt.Sprintf("(%s).%s", relType(recv, from), f.name) +} + +// writeSignature writes to buf the signature sig in declaration syntax. +func writeSignature(buf *bytes.Buffer, from *types.Package, name string, sig *types.Signature, params []*Parameter) { + buf.WriteString("func ") + if recv := sig.Recv(); recv != nil { + buf.WriteString("(") + if n := params[0].Name(); n != "" { + buf.WriteString(n) + buf.WriteString(" ") + } + types.WriteType(buf, params[0].Type(), types.RelativeTo(from)) + buf.WriteString(") ") + } + buf.WriteString(name) + types.WriteSignature(buf, sig, types.RelativeTo(from)) +} + +func (f *Function) pkg() *types.Package { + if f.Pkg != nil { + return f.Pkg.Pkg + } + return nil +} + +var _ io.WriterTo = (*Function)(nil) // *Function implements io.Writer + +func (f *Function) WriteTo(w io.Writer) (int64, error) { + var buf bytes.Buffer + WriteFunction(&buf, f) + n, err := w.Write(buf.Bytes()) + return int64(n), err +} + +// WriteFunction writes to buf a human-readable "disassembly" of f. +func WriteFunction(buf *bytes.Buffer, f *Function) { + fmt.Fprintf(buf, "# Name: %s\n", f.String()) + if f.Pkg != nil { + fmt.Fprintf(buf, "# Package: %s\n", f.Pkg.Pkg.Path()) + } + if syn := f.Synthetic; syn != "" { + fmt.Fprintln(buf, "# Synthetic:", syn) + } + if pos := f.Pos(); pos.IsValid() { + fmt.Fprintf(buf, "# Location: %s\n", f.Prog.Fset.Position(pos)) + } + + if f.parent != nil { + fmt.Fprintf(buf, "# Parent: %s\n", f.parent.Name()) + } + + if f.Recover != nil { + fmt.Fprintf(buf, "# Recover: %s\n", f.Recover) + } + + from := f.pkg() + + if f.FreeVars != nil { + buf.WriteString("# Free variables:\n") + for i, fv := range f.FreeVars { + fmt.Fprintf(buf, "# % 3d:\t%s %s\n", i, fv.Name(), relType(fv.Type(), from)) + } + } + + if len(f.Locals) > 0 { + buf.WriteString("# Locals:\n") + for i, l := range f.Locals { + fmt.Fprintf(buf, "# % 3d:\t%s %s\n", i, l.Name(), relType(deref(l.Type()), from)) + } + } + writeSignature(buf, from, f.Name(), f.Signature, f.Params) + buf.WriteString(":\n") + + if f.Blocks == nil { + buf.WriteString("\t(external)\n") + } + + // NB. column calculations are confused by non-ASCII + // characters and assume 8-space tabs. + const punchcard = 80 // for old time's sake. + const tabwidth = 8 + for _, b := range f.Blocks { + if b == nil { + // Corrupt CFG. + fmt.Fprintf(buf, ".nil:\n") + continue + } + n, _ := fmt.Fprintf(buf, "%d:", b.Index) + bmsg := fmt.Sprintf("%s P:%d S:%d", b.Comment, len(b.Preds), len(b.Succs)) + fmt.Fprintf(buf, "%*s%s\n", punchcard-1-n-len(bmsg), "", bmsg) + + if false { // CFG debugging + fmt.Fprintf(buf, "\t# CFG: %s --> %s --> %s\n", b.Preds, b, b.Succs) + } + for _, instr := range b.Instrs { + buf.WriteString("\t") + switch v := instr.(type) { + case Value: + l := punchcard - tabwidth + // Left-align the instruction. + if name := v.Name(); name != "" { + n, _ := fmt.Fprintf(buf, "%s = ", name) + l -= n + } + n, _ := buf.WriteString(instr.String()) + l -= n + // Right-align the type if there's space. + if t := v.Type(); t != nil { + buf.WriteByte(' ') + ts := relType(t, from) + l -= len(ts) + len(" ") // (spaces before and after type) + if l > 0 { + fmt.Fprintf(buf, "%*s", l, "") + } + buf.WriteString(ts) + } + case nil: + // Be robust against bad transforms. + buf.WriteString("<deleted>") + default: + buf.WriteString(instr.String()) + } + buf.WriteString("\n") + } + } + fmt.Fprintf(buf, "\n") +} + +// newBasicBlock adds to f a new basic block and returns it. It does +// not automatically become the current block for subsequent calls to emit. +// comment is an optional string for more readable debugging output. +// +func (f *Function) newBasicBlock(comment string) *BasicBlock { + b := &BasicBlock{ + Index: len(f.Blocks), + Comment: comment, + parent: f, + } + b.Succs = b.succs2[:0] + f.Blocks = append(f.Blocks, b) + return b +} + +// NewFunction returns a new synthetic Function instance belonging to +// prog, with its name and signature fields set as specified. +// +// The caller is responsible for initializing the remaining fields of +// the function object, e.g. Pkg, Params, Blocks. +// +// It is practically impossible for clients to construct well-formed +// SSA functions/packages/programs directly, so we assume this is the +// job of the Builder alone. NewFunction exists to provide clients a +// little flexibility. For example, analysis tools may wish to +// construct fake Functions for the root of the callgraph, a fake +// "reflect" package, etc. +// +// TODO(adonovan): think harder about the API here. +// +func (prog *Program) NewFunction(name string, sig *types.Signature, provenance string) *Function { + return &Function{Prog: prog, name: name, Signature: sig, Synthetic: provenance} +} + +type extentNode [2]token.Pos + +func (n extentNode) Pos() token.Pos { return n[0] } +func (n extentNode) End() token.Pos { return n[1] } + +// Syntax returns an ast.Node whose Pos/End methods provide the +// lexical extent of the function if it was defined by Go source code +// (f.Synthetic==""), or nil otherwise. +// +// If f was built with debug information (see Package.SetDebugRef), +// the result is the *ast.FuncDecl or *ast.FuncLit that declared the +// function. Otherwise, it is an opaque Node providing only position +// information; this avoids pinning the AST in memory. +// +func (f *Function) Syntax() ast.Node { return f.syntax } diff --git a/vendor/golang.org/x/tools/go/ssa/identical.go b/vendor/golang.org/x/tools/go/ssa/identical.go new file mode 100644 index 0000000..53cbee1 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/identical.go @@ -0,0 +1,7 @@ +// +build go1.8 + +package ssa + +import "go/types" + +var structTypesIdentical = types.IdenticalIgnoreTags diff --git a/vendor/golang.org/x/tools/go/ssa/identical_17.go b/vendor/golang.org/x/tools/go/ssa/identical_17.go new file mode 100644 index 0000000..da89d33 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/identical_17.go @@ -0,0 +1,7 @@ +// +build !go1.8 + +package ssa + +import "go/types" + +var structTypesIdentical = types.Identical diff --git a/vendor/golang.org/x/tools/go/ssa/identical_test.go b/vendor/golang.org/x/tools/go/ssa/identical_test.go new file mode 100644 index 0000000..404693d --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/identical_test.go @@ -0,0 +1,9 @@ +//+build go1.8 + +package ssa_test + +import "testing" + +func TestValueForExprStructConv(t *testing.T) { + testValueForExpr(t, "testdata/structconv.go") +} diff --git a/vendor/golang.org/x/tools/go/ssa/lift.go b/vendor/golang.org/x/tools/go/ssa/lift.go new file mode 100644 index 0000000..048e9b0 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/lift.go @@ -0,0 +1,653 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines the lifting pass which tries to "lift" Alloc +// cells (new/local variables) into SSA registers, replacing loads +// with the dominating stored value, eliminating loads and stores, and +// inserting φ-nodes as needed. + +// Cited papers and resources: +// +// Ron Cytron et al. 1991. Efficiently computing SSA form... +// http://doi.acm.org/10.1145/115372.115320 +// +// Cooper, Harvey, Kennedy. 2001. A Simple, Fast Dominance Algorithm. +// Software Practice and Experience 2001, 4:1-10. +// http://www.hipersoft.rice.edu/grads/publications/dom14.pdf +// +// Daniel Berlin, llvmdev mailing list, 2012. +// http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-January/046638.html +// (Be sure to expand the whole thread.) + +// TODO(adonovan): opt: there are many optimizations worth evaluating, and +// the conventional wisdom for SSA construction is that a simple +// algorithm well engineered often beats those of better asymptotic +// complexity on all but the most egregious inputs. +// +// Danny Berlin suggests that the Cooper et al. algorithm for +// computing the dominance frontier is superior to Cytron et al. +// Furthermore he recommends that rather than computing the DF for the +// whole function then renaming all alloc cells, it may be cheaper to +// compute the DF for each alloc cell separately and throw it away. +// +// Consider exploiting liveness information to avoid creating dead +// φ-nodes which we then immediately remove. +// +// Also see many other "TODO: opt" suggestions in the code. + +import ( + "fmt" + "go/token" + "go/types" + "math/big" + "os" +) + +// If true, show diagnostic information at each step of lifting. +// Very verbose. +const debugLifting = false + +// domFrontier maps each block to the set of blocks in its dominance +// frontier. The outer slice is conceptually a map keyed by +// Block.Index. The inner slice is conceptually a set, possibly +// containing duplicates. +// +// TODO(adonovan): opt: measure impact of dups; consider a packed bit +// representation, e.g. big.Int, and bitwise parallel operations for +// the union step in the Children loop. +// +// domFrontier's methods mutate the slice's elements but not its +// length, so their receivers needn't be pointers. +// +type domFrontier [][]*BasicBlock + +func (df domFrontier) add(u, v *BasicBlock) { + p := &df[u.Index] + *p = append(*p, v) +} + +// build builds the dominance frontier df for the dominator (sub)tree +// rooted at u, using the Cytron et al. algorithm. +// +// TODO(adonovan): opt: consider Berlin approach, computing pruned SSA +// by pruning the entire IDF computation, rather than merely pruning +// the DF -> IDF step. +func (df domFrontier) build(u *BasicBlock) { + // Encounter each node u in postorder of dom tree. + for _, child := range u.dom.children { + df.build(child) + } + for _, vb := range u.Succs { + if v := vb.dom; v.idom != u { + df.add(u, vb) + } + } + for _, w := range u.dom.children { + for _, vb := range df[w.Index] { + // TODO(adonovan): opt: use word-parallel bitwise union. + if v := vb.dom; v.idom != u { + df.add(u, vb) + } + } + } +} + +func buildDomFrontier(fn *Function) domFrontier { + df := make(domFrontier, len(fn.Blocks)) + df.build(fn.Blocks[0]) + if fn.Recover != nil { + df.build(fn.Recover) + } + return df +} + +func removeInstr(refs []Instruction, instr Instruction) []Instruction { + i := 0 + for _, ref := range refs { + if ref == instr { + continue + } + refs[i] = ref + i++ + } + for j := i; j != len(refs); j++ { + refs[j] = nil // aid GC + } + return refs[:i] +} + +// lift replaces local and new Allocs accessed only with +// load/store by SSA registers, inserting φ-nodes where necessary. +// The result is a program in classical pruned SSA form. +// +// Preconditions: +// - fn has no dead blocks (blockopt has run). +// - Def/use info (Operands and Referrers) is up-to-date. +// - The dominator tree is up-to-date. +// +func lift(fn *Function) { + // TODO(adonovan): opt: lots of little optimizations may be + // worthwhile here, especially if they cause us to avoid + // buildDomFrontier. For example: + // + // - Alloc never loaded? Eliminate. + // - Alloc never stored? Replace all loads with a zero constant. + // - Alloc stored once? Replace loads with dominating store; + // don't forget that an Alloc is itself an effective store + // of zero. + // - Alloc used only within a single block? + // Use degenerate algorithm avoiding φ-nodes. + // - Consider synergy with scalar replacement of aggregates (SRA). + // e.g. *(&x.f) where x is an Alloc. + // Perhaps we'd get better results if we generated this as x.f + // i.e. Field(x, .f) instead of Load(FieldIndex(x, .f)). + // Unclear. + // + // But we will start with the simplest correct code. + df := buildDomFrontier(fn) + + if debugLifting { + title := false + for i, blocks := range df { + if blocks != nil { + if !title { + fmt.Fprintf(os.Stderr, "Dominance frontier of %s:\n", fn) + title = true + } + fmt.Fprintf(os.Stderr, "\t%s: %s\n", fn.Blocks[i], blocks) + } + } + } + + newPhis := make(newPhiMap) + + // During this pass we will replace some BasicBlock.Instrs + // (allocs, loads and stores) with nil, keeping a count in + // BasicBlock.gaps. At the end we will reset Instrs to the + // concatenation of all non-dead newPhis and non-nil Instrs + // for the block, reusing the original array if space permits. + + // While we're here, we also eliminate 'rundefers' + // instructions in functions that contain no 'defer' + // instructions. + usesDefer := false + + // A counter used to generate ~unique ids for Phi nodes, as an + // aid to debugging. We use large numbers to make them highly + // visible. All nodes are renumbered later. + fresh := 1000 + + // Determine which allocs we can lift and number them densely. + // The renaming phase uses this numbering for compact maps. + numAllocs := 0 + for _, b := range fn.Blocks { + b.gaps = 0 + b.rundefers = 0 + for _, instr := range b.Instrs { + switch instr := instr.(type) { + case *Alloc: + index := -1 + if liftAlloc(df, instr, newPhis, &fresh) { + index = numAllocs + numAllocs++ + } + instr.index = index + case *Defer: + usesDefer = true + case *RunDefers: + b.rundefers++ + } + } + } + + // renaming maps an alloc (keyed by index) to its replacement + // value. Initially the renaming contains nil, signifying the + // zero constant of the appropriate type; we construct the + // Const lazily at most once on each path through the domtree. + // TODO(adonovan): opt: cache per-function not per subtree. + renaming := make([]Value, numAllocs) + + // Renaming. + rename(fn.Blocks[0], renaming, newPhis) + + // Eliminate dead φ-nodes. + removeDeadPhis(fn.Blocks, newPhis) + + // Prepend remaining live φ-nodes to each block. + for _, b := range fn.Blocks { + nps := newPhis[b] + j := len(nps) + + rundefersToKill := b.rundefers + if usesDefer { + rundefersToKill = 0 + } + + if j+b.gaps+rundefersToKill == 0 { + continue // fast path: no new phis or gaps + } + + // Compact nps + non-nil Instrs into a new slice. + // TODO(adonovan): opt: compact in situ (rightwards) + // if Instrs has sufficient space or slack. + dst := make([]Instruction, len(b.Instrs)+j-b.gaps-rundefersToKill) + for i, np := range nps { + dst[i] = np.phi + } + for _, instr := range b.Instrs { + if instr == nil { + continue + } + if !usesDefer { + if _, ok := instr.(*RunDefers); ok { + continue + } + } + dst[j] = instr + j++ + } + b.Instrs = dst + } + + // Remove any fn.Locals that were lifted. + j := 0 + for _, l := range fn.Locals { + if l.index < 0 { + fn.Locals[j] = l + j++ + } + } + // Nil out fn.Locals[j:] to aid GC. + for i := j; i < len(fn.Locals); i++ { + fn.Locals[i] = nil + } + fn.Locals = fn.Locals[:j] +} + +// removeDeadPhis removes φ-nodes not transitively needed by a +// non-Phi, non-DebugRef instruction. +func removeDeadPhis(blocks []*BasicBlock, newPhis newPhiMap) { + // First pass: find the set of "live" φ-nodes: those reachable + // from some non-Phi instruction. + // + // We compute reachability in reverse, starting from each φ, + // rather than forwards, starting from each live non-Phi + // instruction, because this way visits much less of the + // Value graph. + livePhis := make(map[*Phi]bool) + for _, npList := range newPhis { + for _, np := range npList { + phi := np.phi + if !livePhis[phi] && phiHasDirectReferrer(phi) { + markLivePhi(livePhis, phi) + } + } + } + + // Existing φ-nodes due to && and || operators + // are all considered live (see Go issue 19622). + for _, b := range blocks { + for _, phi := range b.phis() { + markLivePhi(livePhis, phi.(*Phi)) + } + } + + // Second pass: eliminate unused phis from newPhis. + for block, npList := range newPhis { + j := 0 + for _, np := range npList { + if livePhis[np.phi] { + npList[j] = np + j++ + } else { + // discard it, first removing it from referrers + for _, val := range np.phi.Edges { + if refs := val.Referrers(); refs != nil { + *refs = removeInstr(*refs, np.phi) + } + } + np.phi.block = nil + } + } + newPhis[block] = npList[:j] + } +} + +// markLivePhi marks phi, and all φ-nodes transitively reachable via +// its Operands, live. +func markLivePhi(livePhis map[*Phi]bool, phi *Phi) { + livePhis[phi] = true + for _, rand := range phi.Operands(nil) { + if q, ok := (*rand).(*Phi); ok { + if !livePhis[q] { + markLivePhi(livePhis, q) + } + } + } +} + +// phiHasDirectReferrer reports whether phi is directly referred to by +// a non-Phi instruction. Such instructions are the +// roots of the liveness traversal. +func phiHasDirectReferrer(phi *Phi) bool { + for _, instr := range *phi.Referrers() { + if _, ok := instr.(*Phi); !ok { + return true + } + } + return false +} + +type blockSet struct{ big.Int } // (inherit methods from Int) + +// add adds b to the set and returns true if the set changed. +func (s *blockSet) add(b *BasicBlock) bool { + i := b.Index + if s.Bit(i) != 0 { + return false + } + s.SetBit(&s.Int, i, 1) + return true +} + +// take removes an arbitrary element from a set s and +// returns its index, or returns -1 if empty. +func (s *blockSet) take() int { + l := s.BitLen() + for i := 0; i < l; i++ { + if s.Bit(i) == 1 { + s.SetBit(&s.Int, i, 0) + return i + } + } + return -1 +} + +// newPhi is a pair of a newly introduced φ-node and the lifted Alloc +// it replaces. +type newPhi struct { + phi *Phi + alloc *Alloc +} + +// newPhiMap records for each basic block, the set of newPhis that +// must be prepended to the block. +type newPhiMap map[*BasicBlock][]newPhi + +// liftAlloc determines whether alloc can be lifted into registers, +// and if so, it populates newPhis with all the φ-nodes it may require +// and returns true. +// +// fresh is a source of fresh ids for phi nodes. +// +func liftAlloc(df domFrontier, alloc *Alloc, newPhis newPhiMap, fresh *int) bool { + // Don't lift aggregates into registers, because we don't have + // a way to express their zero-constants. + switch deref(alloc.Type()).Underlying().(type) { + case *types.Array, *types.Struct: + return false + } + + // Don't lift named return values in functions that defer + // calls that may recover from panic. + if fn := alloc.Parent(); fn.Recover != nil { + for _, nr := range fn.namedResults { + if nr == alloc { + return false + } + } + } + + // Compute defblocks, the set of blocks containing a + // definition of the alloc cell. + var defblocks blockSet + for _, instr := range *alloc.Referrers() { + // Bail out if we discover the alloc is not liftable; + // the only operations permitted to use the alloc are + // loads/stores into the cell, and DebugRef. + switch instr := instr.(type) { + case *Store: + if instr.Val == alloc { + return false // address used as value + } + if instr.Addr != alloc { + panic("Alloc.Referrers is inconsistent") + } + defblocks.add(instr.Block()) + case *UnOp: + if instr.Op != token.MUL { + return false // not a load + } + if instr.X != alloc { + panic("Alloc.Referrers is inconsistent") + } + case *DebugRef: + // ok + default: + return false // some other instruction + } + } + // The Alloc itself counts as a (zero) definition of the cell. + defblocks.add(alloc.Block()) + + if debugLifting { + fmt.Fprintln(os.Stderr, "\tlifting ", alloc, alloc.Name()) + } + + fn := alloc.Parent() + + // Φ-insertion. + // + // What follows is the body of the main loop of the insert-φ + // function described by Cytron et al, but instead of using + // counter tricks, we just reset the 'hasAlready' and 'work' + // sets each iteration. These are bitmaps so it's pretty cheap. + // + // TODO(adonovan): opt: recycle slice storage for W, + // hasAlready, defBlocks across liftAlloc calls. + var hasAlready blockSet + + // Initialize W and work to defblocks. + var work blockSet = defblocks // blocks seen + var W blockSet // blocks to do + W.Set(&defblocks.Int) + + // Traverse iterated dominance frontier, inserting φ-nodes. + for i := W.take(); i != -1; i = W.take() { + u := fn.Blocks[i] + for _, v := range df[u.Index] { + if hasAlready.add(v) { + // Create φ-node. + // It will be prepended to v.Instrs later, if needed. + phi := &Phi{ + Edges: make([]Value, len(v.Preds)), + Comment: alloc.Comment, + } + // This is merely a debugging aid: + phi.setNum(*fresh) + *fresh++ + + phi.pos = alloc.Pos() + phi.setType(deref(alloc.Type())) + phi.block = v + if debugLifting { + fmt.Fprintf(os.Stderr, "\tplace %s = %s at block %s\n", phi.Name(), phi, v) + } + newPhis[v] = append(newPhis[v], newPhi{phi, alloc}) + + if work.add(v) { + W.add(v) + } + } + } + } + + return true +} + +// replaceAll replaces all intraprocedural uses of x with y, +// updating x.Referrers and y.Referrers. +// Precondition: x.Referrers() != nil, i.e. x must be local to some function. +// +func replaceAll(x, y Value) { + var rands []*Value + pxrefs := x.Referrers() + pyrefs := y.Referrers() + for _, instr := range *pxrefs { + rands = instr.Operands(rands[:0]) // recycle storage + for _, rand := range rands { + if *rand != nil { + if *rand == x { + *rand = y + } + } + } + if pyrefs != nil { + *pyrefs = append(*pyrefs, instr) // dups ok + } + } + *pxrefs = nil // x is now unreferenced +} + +// renamed returns the value to which alloc is being renamed, +// constructing it lazily if it's the implicit zero initialization. +// +func renamed(renaming []Value, alloc *Alloc) Value { + v := renaming[alloc.index] + if v == nil { + v = zeroConst(deref(alloc.Type())) + renaming[alloc.index] = v + } + return v +} + +// rename implements the (Cytron et al) SSA renaming algorithm, a +// preorder traversal of the dominator tree replacing all loads of +// Alloc cells with the value stored to that cell by the dominating +// store instruction. For lifting, we need only consider loads, +// stores and φ-nodes. +// +// renaming is a map from *Alloc (keyed by index number) to its +// dominating stored value; newPhis[x] is the set of new φ-nodes to be +// prepended to block x. +// +func rename(u *BasicBlock, renaming []Value, newPhis newPhiMap) { + // Each φ-node becomes the new name for its associated Alloc. + for _, np := range newPhis[u] { + phi := np.phi + alloc := np.alloc + renaming[alloc.index] = phi + } + + // Rename loads and stores of allocs. + for i, instr := range u.Instrs { + switch instr := instr.(type) { + case *Alloc: + if instr.index >= 0 { // store of zero to Alloc cell + // Replace dominated loads by the zero value. + renaming[instr.index] = nil + if debugLifting { + fmt.Fprintf(os.Stderr, "\tkill alloc %s\n", instr) + } + // Delete the Alloc. + u.Instrs[i] = nil + u.gaps++ + } + + case *Store: + if alloc, ok := instr.Addr.(*Alloc); ok && alloc.index >= 0 { // store to Alloc cell + // Replace dominated loads by the stored value. + renaming[alloc.index] = instr.Val + if debugLifting { + fmt.Fprintf(os.Stderr, "\tkill store %s; new value: %s\n", + instr, instr.Val.Name()) + } + // Remove the store from the referrer list of the stored value. + if refs := instr.Val.Referrers(); refs != nil { + *refs = removeInstr(*refs, instr) + } + // Delete the Store. + u.Instrs[i] = nil + u.gaps++ + } + + case *UnOp: + if instr.Op == token.MUL { + if alloc, ok := instr.X.(*Alloc); ok && alloc.index >= 0 { // load of Alloc cell + newval := renamed(renaming, alloc) + if debugLifting { + fmt.Fprintf(os.Stderr, "\tupdate load %s = %s with %s\n", + instr.Name(), instr, newval.Name()) + } + // Replace all references to + // the loaded value by the + // dominating stored value. + replaceAll(instr, newval) + // Delete the Load. + u.Instrs[i] = nil + u.gaps++ + } + } + + case *DebugRef: + if alloc, ok := instr.X.(*Alloc); ok && alloc.index >= 0 { // ref of Alloc cell + if instr.IsAddr { + instr.X = renamed(renaming, alloc) + instr.IsAddr = false + + // Add DebugRef to instr.X's referrers. + if refs := instr.X.Referrers(); refs != nil { + *refs = append(*refs, instr) + } + } else { + // A source expression denotes the address + // of an Alloc that was optimized away. + instr.X = nil + + // Delete the DebugRef. + u.Instrs[i] = nil + u.gaps++ + } + } + } + } + + // For each φ-node in a CFG successor, rename the edge. + for _, v := range u.Succs { + phis := newPhis[v] + if len(phis) == 0 { + continue + } + i := v.predIndex(u) + for _, np := range phis { + phi := np.phi + alloc := np.alloc + newval := renamed(renaming, alloc) + if debugLifting { + fmt.Fprintf(os.Stderr, "\tsetphi %s edge %s -> %s (#%d) (alloc=%s) := %s\n", + phi.Name(), u, v, i, alloc.Name(), newval.Name()) + } + phi.Edges[i] = newval + if prefs := newval.Referrers(); prefs != nil { + *prefs = append(*prefs, phi) + } + } + } + + // Continue depth-first recursion over domtree, pushing a + // fresh copy of the renaming map for each subtree. + for i, v := range u.dom.children { + r := renaming + if i < len(u.dom.children)-1 { + // On all but the final iteration, we must make + // a copy to avoid destructive update. + r = make([]Value, len(renaming)) + copy(r, renaming) + } + rename(v, r, newPhis) + } + +} diff --git a/vendor/golang.org/x/tools/go/ssa/lvalue.go b/vendor/golang.org/x/tools/go/ssa/lvalue.go new file mode 100644 index 0000000..4d85be3 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/lvalue.go @@ -0,0 +1,120 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// lvalues are the union of addressable expressions and map-index +// expressions. + +import ( + "go/ast" + "go/token" + "go/types" +) + +// An lvalue represents an assignable location that may appear on the +// left-hand side of an assignment. This is a generalization of a +// pointer to permit updates to elements of maps. +// +type lvalue interface { + store(fn *Function, v Value) // stores v into the location + load(fn *Function) Value // loads the contents of the location + address(fn *Function) Value // address of the location + typ() types.Type // returns the type of the location +} + +// An address is an lvalue represented by a true pointer. +type address struct { + addr Value + pos token.Pos // source position + expr ast.Expr // source syntax of the value (not address) [debug mode] +} + +func (a *address) load(fn *Function) Value { + load := emitLoad(fn, a.addr) + load.pos = a.pos + return load +} + +func (a *address) store(fn *Function, v Value) { + store := emitStore(fn, a.addr, v, a.pos) + if a.expr != nil { + // store.Val is v, converted for assignability. + emitDebugRef(fn, a.expr, store.Val, false) + } +} + +func (a *address) address(fn *Function) Value { + if a.expr != nil { + emitDebugRef(fn, a.expr, a.addr, true) + } + return a.addr +} + +func (a *address) typ() types.Type { + return deref(a.addr.Type()) +} + +// An element is an lvalue represented by m[k], the location of an +// element of a map or string. These locations are not addressable +// since pointers cannot be formed from them, but they do support +// load(), and in the case of maps, store(). +// +type element struct { + m, k Value // map or string + t types.Type // map element type or string byte type + pos token.Pos // source position of colon ({k:v}) or lbrack (m[k]=v) +} + +func (e *element) load(fn *Function) Value { + l := &Lookup{ + X: e.m, + Index: e.k, + } + l.setPos(e.pos) + l.setType(e.t) + return fn.emit(l) +} + +func (e *element) store(fn *Function, v Value) { + up := &MapUpdate{ + Map: e.m, + Key: e.k, + Value: emitConv(fn, v, e.t), + } + up.pos = e.pos + fn.emit(up) +} + +func (e *element) address(fn *Function) Value { + panic("map/string elements are not addressable") +} + +func (e *element) typ() types.Type { + return e.t +} + +// A blank is a dummy variable whose name is "_". +// It is not reified: loads are illegal and stores are ignored. +// +type blank struct{} + +func (bl blank) load(fn *Function) Value { + panic("blank.load is illegal") +} + +func (bl blank) store(fn *Function, v Value) { + // no-op +} + +func (bl blank) address(fn *Function) Value { + panic("blank var is not addressable") +} + +func (bl blank) typ() types.Type { + // This should be the type of the blank Ident; the typechecker + // doesn't provide this yet, but fortunately, we don't need it + // yet either. + panic("blank.typ is unimplemented") +} diff --git a/vendor/golang.org/x/tools/go/ssa/methods.go b/vendor/golang.org/x/tools/go/ssa/methods.go new file mode 100644 index 0000000..080dca9 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/methods.go @@ -0,0 +1,239 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines utilities for population of method sets. + +import ( + "fmt" + "go/types" +) + +// MethodValue returns the Function implementing method sel, building +// wrapper methods on demand. It returns nil if sel denotes an +// abstract (interface) method. +// +// Precondition: sel.Kind() == MethodVal. +// +// Thread-safe. +// +// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu) +// +func (prog *Program) MethodValue(sel *types.Selection) *Function { + if sel.Kind() != types.MethodVal { + panic(fmt.Sprintf("Method(%s) kind != MethodVal", sel)) + } + T := sel.Recv() + if isInterface(T) { + return nil // abstract method + } + if prog.mode&LogSource != 0 { + defer logStack("Method %s %v", T, sel)() + } + + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + + return prog.addMethod(prog.createMethodSet(T), sel) +} + +// LookupMethod returns the implementation of the method of type T +// identified by (pkg, name). It returns nil if the method exists but +// is abstract, and panics if T has no such method. +// +func (prog *Program) LookupMethod(T types.Type, pkg *types.Package, name string) *Function { + sel := prog.MethodSets.MethodSet(T).Lookup(pkg, name) + if sel == nil { + panic(fmt.Sprintf("%s has no method %s", T, types.Id(pkg, name))) + } + return prog.MethodValue(sel) +} + +// methodSet contains the (concrete) methods of a non-interface type. +type methodSet struct { + mapping map[string]*Function // populated lazily + complete bool // mapping contains all methods +} + +// Precondition: !isInterface(T). +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +func (prog *Program) createMethodSet(T types.Type) *methodSet { + mset, ok := prog.methodSets.At(T).(*methodSet) + if !ok { + mset = &methodSet{mapping: make(map[string]*Function)} + prog.methodSets.Set(T, mset) + } + return mset +} + +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +func (prog *Program) addMethod(mset *methodSet, sel *types.Selection) *Function { + if sel.Kind() == types.MethodExpr { + panic(sel) + } + id := sel.Obj().Id() + fn := mset.mapping[id] + if fn == nil { + obj := sel.Obj().(*types.Func) + + needsPromotion := len(sel.Index()) > 1 + needsIndirection := !isPointer(recvType(obj)) && isPointer(sel.Recv()) + if needsPromotion || needsIndirection { + fn = makeWrapper(prog, sel) + } else { + fn = prog.declaredFunc(obj) + } + if fn.Signature.Recv() == nil { + panic(fn) // missing receiver + } + mset.mapping[id] = fn + } + return fn +} + +// RuntimeTypes returns a new unordered slice containing all +// concrete types in the program for which a complete (non-empty) +// method set is required at run-time. +// +// Thread-safe. +// +// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu) +// +func (prog *Program) RuntimeTypes() []types.Type { + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + + var res []types.Type + prog.methodSets.Iterate(func(T types.Type, v interface{}) { + if v.(*methodSet).complete { + res = append(res, T) + } + }) + return res +} + +// declaredFunc returns the concrete function/method denoted by obj. +// Panic ensues if there is none. +// +func (prog *Program) declaredFunc(obj *types.Func) *Function { + if v := prog.packageLevelValue(obj); v != nil { + return v.(*Function) + } + panic("no concrete method: " + obj.String()) +} + +// needMethodsOf ensures that runtime type information (including the +// complete method set) is available for the specified type T and all +// its subcomponents. +// +// needMethodsOf must be called for at least every type that is an +// operand of some MakeInterface instruction, and for the type of +// every exported package member. +// +// Precondition: T is not a method signature (*Signature with Recv()!=nil). +// +// Thread-safe. (Called via emitConv from multiple builder goroutines.) +// +// TODO(adonovan): make this faster. It accounts for 20% of SSA build time. +// +// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu) +// +func (prog *Program) needMethodsOf(T types.Type) { + prog.methodsMu.Lock() + prog.needMethods(T, false) + prog.methodsMu.Unlock() +} + +// Precondition: T is not a method signature (*Signature with Recv()!=nil). +// Recursive case: skip => don't create methods for T. +// +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +// +func (prog *Program) needMethods(T types.Type, skip bool) { + // Each package maintains its own set of types it has visited. + if prevSkip, ok := prog.runtimeTypes.At(T).(bool); ok { + // needMethods(T) was previously called + if !prevSkip || skip { + return // already seen, with same or false 'skip' value + } + } + prog.runtimeTypes.Set(T, skip) + + tmset := prog.MethodSets.MethodSet(T) + + if !skip && !isInterface(T) && tmset.Len() > 0 { + // Create methods of T. + mset := prog.createMethodSet(T) + if !mset.complete { + mset.complete = true + n := tmset.Len() + for i := 0; i < n; i++ { + prog.addMethod(mset, tmset.At(i)) + } + } + } + + // Recursion over signatures of each method. + for i := 0; i < tmset.Len(); i++ { + sig := tmset.At(i).Type().(*types.Signature) + prog.needMethods(sig.Params(), false) + prog.needMethods(sig.Results(), false) + } + + switch t := T.(type) { + case *types.Basic: + // nop + + case *types.Interface: + // nop---handled by recursion over method set. + + case *types.Pointer: + prog.needMethods(t.Elem(), false) + + case *types.Slice: + prog.needMethods(t.Elem(), false) + + case *types.Chan: + prog.needMethods(t.Elem(), false) + + case *types.Map: + prog.needMethods(t.Key(), false) + prog.needMethods(t.Elem(), false) + + case *types.Signature: + if t.Recv() != nil { + panic(fmt.Sprintf("Signature %s has Recv %s", t, t.Recv())) + } + prog.needMethods(t.Params(), false) + prog.needMethods(t.Results(), false) + + case *types.Named: + // A pointer-to-named type can be derived from a named + // type via reflection. It may have methods too. + prog.needMethods(types.NewPointer(T), false) + + // Consider 'type T struct{S}' where S has methods. + // Reflection provides no way to get from T to struct{S}, + // only to S, so the method set of struct{S} is unwanted, + // so set 'skip' flag during recursion. + prog.needMethods(t.Underlying(), true) + + case *types.Array: + prog.needMethods(t.Elem(), false) + + case *types.Struct: + for i, n := 0, t.NumFields(); i < n; i++ { + prog.needMethods(t.Field(i).Type(), false) + } + + case *types.Tuple: + for i, n := 0, t.Len(); i < n; i++ { + prog.needMethods(t.At(i).Type(), false) + } + + default: + panic(T) + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/mode.go b/vendor/golang.org/x/tools/go/ssa/mode.go new file mode 100644 index 0000000..d2a2698 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/mode.go @@ -0,0 +1,100 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines the BuilderMode type and its command-line flag. + +import ( + "bytes" + "fmt" +) + +// BuilderMode is a bitmask of options for diagnostics and checking. +// +// *BuilderMode satisfies the flag.Value interface. Example: +// +// var mode = ssa.BuilderMode(0) +// func init() { flag.Var(&mode, "build", ssa.BuilderModeDoc) } +// +type BuilderMode uint + +const ( + PrintPackages BuilderMode = 1 << iota // Print package inventory to stdout + PrintFunctions // Print function SSA code to stdout + LogSource // Log source locations as SSA builder progresses + SanityCheckFunctions // Perform sanity checking of function bodies + NaiveForm // Build naïve SSA form: don't replace local loads/stores with registers + BuildSerially // Build packages serially, not in parallel. + GlobalDebug // Enable debug info for all packages + BareInits // Build init functions without guards or calls to dependent inits +) + +const BuilderModeDoc = `Options controlling the SSA builder. +The value is a sequence of zero or more of these letters: +C perform sanity [C]hecking of the SSA form. +D include [D]ebug info for every function. +P print [P]ackage inventory. +F print [F]unction SSA code. +S log [S]ource locations as SSA builder progresses. +L build distinct packages seria[L]ly instead of in parallel. +N build [N]aive SSA form: don't replace local loads/stores with registers. +I build bare [I]nit functions: no init guards or calls to dependent inits. +` + +func (m BuilderMode) String() string { + var buf bytes.Buffer + if m&GlobalDebug != 0 { + buf.WriteByte('D') + } + if m&PrintPackages != 0 { + buf.WriteByte('P') + } + if m&PrintFunctions != 0 { + buf.WriteByte('F') + } + if m&LogSource != 0 { + buf.WriteByte('S') + } + if m&SanityCheckFunctions != 0 { + buf.WriteByte('C') + } + if m&NaiveForm != 0 { + buf.WriteByte('N') + } + if m&BuildSerially != 0 { + buf.WriteByte('L') + } + return buf.String() +} + +// Set parses the flag characters in s and updates *m. +func (m *BuilderMode) Set(s string) error { + var mode BuilderMode + for _, c := range s { + switch c { + case 'D': + mode |= GlobalDebug + case 'P': + mode |= PrintPackages + case 'F': + mode |= PrintFunctions + case 'S': + mode |= LogSource | BuildSerially + case 'C': + mode |= SanityCheckFunctions + case 'N': + mode |= NaiveForm + case 'L': + mode |= BuildSerially + default: + return fmt.Errorf("unknown BuilderMode option: %q", c) + } + } + *m = mode + return nil +} + +// Get returns m. +func (m BuilderMode) Get() interface{} { return m } diff --git a/vendor/golang.org/x/tools/go/ssa/print.go b/vendor/golang.org/x/tools/go/ssa/print.go new file mode 100644 index 0000000..3333ba4 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/print.go @@ -0,0 +1,431 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the String() methods for all Value and +// Instruction types. + +import ( + "bytes" + "fmt" + "go/types" + "io" + "reflect" + "sort" + + "golang.org/x/tools/go/types/typeutil" +) + +// relName returns the name of v relative to i. +// In most cases, this is identical to v.Name(), but references to +// Functions (including methods) and Globals use RelString and +// all types are displayed with relType, so that only cross-package +// references are package-qualified. +// +func relName(v Value, i Instruction) string { + var from *types.Package + if i != nil { + from = i.Parent().pkg() + } + switch v := v.(type) { + case Member: // *Function or *Global + return v.RelString(from) + case *Const: + return v.RelString(from) + } + return v.Name() +} + +func relType(t types.Type, from *types.Package) string { + return types.TypeString(t, types.RelativeTo(from)) +} + +func relString(m Member, from *types.Package) string { + // NB: not all globals have an Object (e.g. init$guard), + // so use Package().Object not Object.Package(). + if pkg := m.Package().Pkg; pkg != nil && pkg != from { + return fmt.Sprintf("%s.%s", pkg.Path(), m.Name()) + } + return m.Name() +} + +// Value.String() +// +// This method is provided only for debugging. +// It never appears in disassembly, which uses Value.Name(). + +func (v *Parameter) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("parameter %s : %s", v.Name(), relType(v.Type(), from)) +} + +func (v *FreeVar) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("freevar %s : %s", v.Name(), relType(v.Type(), from)) +} + +func (v *Builtin) String() string { + return fmt.Sprintf("builtin %s", v.Name()) +} + +// Instruction.String() + +func (v *Alloc) String() string { + op := "local" + if v.Heap { + op = "new" + } + from := v.Parent().pkg() + return fmt.Sprintf("%s %s (%s)", op, relType(deref(v.Type()), from), v.Comment) +} + +func (v *Phi) String() string { + var b bytes.Buffer + b.WriteString("phi [") + for i, edge := range v.Edges { + if i > 0 { + b.WriteString(", ") + } + // Be robust against malformed CFG. + if v.block == nil { + b.WriteString("??") + continue + } + block := -1 + if i < len(v.block.Preds) { + block = v.block.Preds[i].Index + } + fmt.Fprintf(&b, "%d: ", block) + edgeVal := "<nil>" // be robust + if edge != nil { + edgeVal = relName(edge, v) + } + b.WriteString(edgeVal) + } + b.WriteString("]") + if v.Comment != "" { + b.WriteString(" #") + b.WriteString(v.Comment) + } + return b.String() +} + +func printCall(v *CallCommon, prefix string, instr Instruction) string { + var b bytes.Buffer + b.WriteString(prefix) + if !v.IsInvoke() { + b.WriteString(relName(v.Value, instr)) + } else { + fmt.Fprintf(&b, "invoke %s.%s", relName(v.Value, instr), v.Method.Name()) + } + b.WriteString("(") + for i, arg := range v.Args { + if i > 0 { + b.WriteString(", ") + } + b.WriteString(relName(arg, instr)) + } + if v.Signature().Variadic() { + b.WriteString("...") + } + b.WriteString(")") + return b.String() +} + +func (c *CallCommon) String() string { + return printCall(c, "", nil) +} + +func (v *Call) String() string { + return printCall(&v.Call, "", v) +} + +func (v *BinOp) String() string { + return fmt.Sprintf("%s %s %s", relName(v.X, v), v.Op.String(), relName(v.Y, v)) +} + +func (v *UnOp) String() string { + return fmt.Sprintf("%s%s%s", v.Op, relName(v.X, v), commaOk(v.CommaOk)) +} + +func printConv(prefix string, v, x Value) string { + from := v.Parent().pkg() + return fmt.Sprintf("%s %s <- %s (%s)", + prefix, + relType(v.Type(), from), + relType(x.Type(), from), + relName(x, v.(Instruction))) +} + +func (v *ChangeType) String() string { return printConv("changetype", v, v.X) } +func (v *Convert) String() string { return printConv("convert", v, v.X) } +func (v *ChangeInterface) String() string { return printConv("change interface", v, v.X) } +func (v *MakeInterface) String() string { return printConv("make", v, v.X) } + +func (v *MakeClosure) String() string { + var b bytes.Buffer + fmt.Fprintf(&b, "make closure %s", relName(v.Fn, v)) + if v.Bindings != nil { + b.WriteString(" [") + for i, c := range v.Bindings { + if i > 0 { + b.WriteString(", ") + } + b.WriteString(relName(c, v)) + } + b.WriteString("]") + } + return b.String() +} + +func (v *MakeSlice) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("make %s %s %s", + relType(v.Type(), from), + relName(v.Len, v), + relName(v.Cap, v)) +} + +func (v *Slice) String() string { + var b bytes.Buffer + b.WriteString("slice ") + b.WriteString(relName(v.X, v)) + b.WriteString("[") + if v.Low != nil { + b.WriteString(relName(v.Low, v)) + } + b.WriteString(":") + if v.High != nil { + b.WriteString(relName(v.High, v)) + } + if v.Max != nil { + b.WriteString(":") + b.WriteString(relName(v.Max, v)) + } + b.WriteString("]") + return b.String() +} + +func (v *MakeMap) String() string { + res := "" + if v.Reserve != nil { + res = relName(v.Reserve, v) + } + from := v.Parent().pkg() + return fmt.Sprintf("make %s %s", relType(v.Type(), from), res) +} + +func (v *MakeChan) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("make %s %s", relType(v.Type(), from), relName(v.Size, v)) +} + +func (v *FieldAddr) String() string { + st := deref(v.X.Type()).Underlying().(*types.Struct) + // Be robust against a bad index. + name := "?" + if 0 <= v.Field && v.Field < st.NumFields() { + name = st.Field(v.Field).Name() + } + return fmt.Sprintf("&%s.%s [#%d]", relName(v.X, v), name, v.Field) +} + +func (v *Field) String() string { + st := v.X.Type().Underlying().(*types.Struct) + // Be robust against a bad index. + name := "?" + if 0 <= v.Field && v.Field < st.NumFields() { + name = st.Field(v.Field).Name() + } + return fmt.Sprintf("%s.%s [#%d]", relName(v.X, v), name, v.Field) +} + +func (v *IndexAddr) String() string { + return fmt.Sprintf("&%s[%s]", relName(v.X, v), relName(v.Index, v)) +} + +func (v *Index) String() string { + return fmt.Sprintf("%s[%s]", relName(v.X, v), relName(v.Index, v)) +} + +func (v *Lookup) String() string { + return fmt.Sprintf("%s[%s]%s", relName(v.X, v), relName(v.Index, v), commaOk(v.CommaOk)) +} + +func (v *Range) String() string { + return "range " + relName(v.X, v) +} + +func (v *Next) String() string { + return "next " + relName(v.Iter, v) +} + +func (v *TypeAssert) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("typeassert%s %s.(%s)", commaOk(v.CommaOk), relName(v.X, v), relType(v.AssertedType, from)) +} + +func (v *Extract) String() string { + return fmt.Sprintf("extract %s #%d", relName(v.Tuple, v), v.Index) +} + +func (s *Jump) String() string { + // Be robust against malformed CFG. + block := -1 + if s.block != nil && len(s.block.Succs) == 1 { + block = s.block.Succs[0].Index + } + return fmt.Sprintf("jump %d", block) +} + +func (s *If) String() string { + // Be robust against malformed CFG. + tblock, fblock := -1, -1 + if s.block != nil && len(s.block.Succs) == 2 { + tblock = s.block.Succs[0].Index + fblock = s.block.Succs[1].Index + } + return fmt.Sprintf("if %s goto %d else %d", relName(s.Cond, s), tblock, fblock) +} + +func (s *Go) String() string { + return printCall(&s.Call, "go ", s) +} + +func (s *Panic) String() string { + return "panic " + relName(s.X, s) +} + +func (s *Return) String() string { + var b bytes.Buffer + b.WriteString("return") + for i, r := range s.Results { + if i == 0 { + b.WriteString(" ") + } else { + b.WriteString(", ") + } + b.WriteString(relName(r, s)) + } + return b.String() +} + +func (*RunDefers) String() string { + return "rundefers" +} + +func (s *Send) String() string { + return fmt.Sprintf("send %s <- %s", relName(s.Chan, s), relName(s.X, s)) +} + +func (s *Defer) String() string { + return printCall(&s.Call, "defer ", s) +} + +func (s *Select) String() string { + var b bytes.Buffer + for i, st := range s.States { + if i > 0 { + b.WriteString(", ") + } + if st.Dir == types.RecvOnly { + b.WriteString("<-") + b.WriteString(relName(st.Chan, s)) + } else { + b.WriteString(relName(st.Chan, s)) + b.WriteString("<-") + b.WriteString(relName(st.Send, s)) + } + } + non := "" + if !s.Blocking { + non = "non" + } + return fmt.Sprintf("select %sblocking [%s]", non, b.String()) +} + +func (s *Store) String() string { + return fmt.Sprintf("*%s = %s", relName(s.Addr, s), relName(s.Val, s)) +} + +func (s *MapUpdate) String() string { + return fmt.Sprintf("%s[%s] = %s", relName(s.Map, s), relName(s.Key, s), relName(s.Value, s)) +} + +func (s *DebugRef) String() string { + p := s.Parent().Prog.Fset.Position(s.Pos()) + var descr interface{} + if s.object != nil { + descr = s.object // e.g. "var x int" + } else { + descr = reflect.TypeOf(s.Expr) // e.g. "*ast.CallExpr" + } + var addr string + if s.IsAddr { + addr = "address of " + } + return fmt.Sprintf("; %s%s @ %d:%d is %s", addr, descr, p.Line, p.Column, s.X.Name()) +} + +func (p *Package) String() string { + return "package " + p.Pkg.Path() +} + +var _ io.WriterTo = (*Package)(nil) // *Package implements io.Writer + +func (p *Package) WriteTo(w io.Writer) (int64, error) { + var buf bytes.Buffer + WritePackage(&buf, p) + n, err := w.Write(buf.Bytes()) + return int64(n), err +} + +// WritePackage writes to buf a human-readable summary of p. +func WritePackage(buf *bytes.Buffer, p *Package) { + fmt.Fprintf(buf, "%s:\n", p) + + var names []string + maxname := 0 + for name := range p.Members { + if l := len(name); l > maxname { + maxname = l + } + names = append(names, name) + } + + from := p.Pkg + sort.Strings(names) + for _, name := range names { + switch mem := p.Members[name].(type) { + case *NamedConst: + fmt.Fprintf(buf, " const %-*s %s = %s\n", + maxname, name, mem.Name(), mem.Value.RelString(from)) + + case *Function: + fmt.Fprintf(buf, " func %-*s %s\n", + maxname, name, relType(mem.Type(), from)) + + case *Type: + fmt.Fprintf(buf, " type %-*s %s\n", + maxname, name, relType(mem.Type().Underlying(), from)) + for _, meth := range typeutil.IntuitiveMethodSet(mem.Type(), &p.Prog.MethodSets) { + fmt.Fprintf(buf, " %s\n", types.SelectionString(meth, types.RelativeTo(from))) + } + + case *Global: + fmt.Fprintf(buf, " var %-*s %s\n", + maxname, name, relType(mem.Type().(*types.Pointer).Elem(), from)) + } + } + + fmt.Fprintf(buf, "\n") +} + +func commaOk(x bool) string { + if x { + return ",ok" + } + return "" +} diff --git a/vendor/golang.org/x/tools/go/ssa/sanity.go b/vendor/golang.org/x/tools/go/ssa/sanity.go new file mode 100644 index 0000000..0d13beb --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/sanity.go @@ -0,0 +1,521 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// An optional pass for sanity-checking invariants of the SSA representation. +// Currently it checks CFG invariants but little at the instruction level. + +import ( + "fmt" + "go/types" + "io" + "os" + "strings" +) + +type sanity struct { + reporter io.Writer + fn *Function + block *BasicBlock + instrs map[Instruction]struct{} + insane bool +} + +// sanityCheck performs integrity checking of the SSA representation +// of the function fn and returns true if it was valid. Diagnostics +// are written to reporter if non-nil, os.Stderr otherwise. Some +// diagnostics are only warnings and do not imply a negative result. +// +// Sanity-checking is intended to facilitate the debugging of code +// transformation passes. +// +func sanityCheck(fn *Function, reporter io.Writer) bool { + if reporter == nil { + reporter = os.Stderr + } + return (&sanity{reporter: reporter}).checkFunction(fn) +} + +// mustSanityCheck is like sanityCheck but panics instead of returning +// a negative result. +// +func mustSanityCheck(fn *Function, reporter io.Writer) { + if !sanityCheck(fn, reporter) { + fn.WriteTo(os.Stderr) + panic("SanityCheck failed") + } +} + +func (s *sanity) diagnostic(prefix, format string, args ...interface{}) { + fmt.Fprintf(s.reporter, "%s: function %s", prefix, s.fn) + if s.block != nil { + fmt.Fprintf(s.reporter, ", block %s", s.block) + } + io.WriteString(s.reporter, ": ") + fmt.Fprintf(s.reporter, format, args...) + io.WriteString(s.reporter, "\n") +} + +func (s *sanity) errorf(format string, args ...interface{}) { + s.insane = true + s.diagnostic("Error", format, args...) +} + +func (s *sanity) warnf(format string, args ...interface{}) { + s.diagnostic("Warning", format, args...) +} + +// findDuplicate returns an arbitrary basic block that appeared more +// than once in blocks, or nil if all were unique. +func findDuplicate(blocks []*BasicBlock) *BasicBlock { + if len(blocks) < 2 { + return nil + } + if blocks[0] == blocks[1] { + return blocks[0] + } + // Slow path: + m := make(map[*BasicBlock]bool) + for _, b := range blocks { + if m[b] { + return b + } + m[b] = true + } + return nil +} + +func (s *sanity) checkInstr(idx int, instr Instruction) { + switch instr := instr.(type) { + case *If, *Jump, *Return, *Panic: + s.errorf("control flow instruction not at end of block") + case *Phi: + if idx == 0 { + // It suffices to apply this check to just the first phi node. + if dup := findDuplicate(s.block.Preds); dup != nil { + s.errorf("phi node in block with duplicate predecessor %s", dup) + } + } else { + prev := s.block.Instrs[idx-1] + if _, ok := prev.(*Phi); !ok { + s.errorf("Phi instruction follows a non-Phi: %T", prev) + } + } + if ne, np := len(instr.Edges), len(s.block.Preds); ne != np { + s.errorf("phi node has %d edges but %d predecessors", ne, np) + + } else { + for i, e := range instr.Edges { + if e == nil { + s.errorf("phi node '%s' has no value for edge #%d from %s", instr.Comment, i, s.block.Preds[i]) + } + } + } + + case *Alloc: + if !instr.Heap { + found := false + for _, l := range s.fn.Locals { + if l == instr { + found = true + break + } + } + if !found { + s.errorf("local alloc %s = %s does not appear in Function.Locals", instr.Name(), instr) + } + } + + case *BinOp: + case *Call: + case *ChangeInterface: + case *ChangeType: + case *Convert: + if _, ok := instr.X.Type().Underlying().(*types.Basic); !ok { + if _, ok := instr.Type().Underlying().(*types.Basic); !ok { + s.errorf("convert %s -> %s: at least one type must be basic", instr.X.Type(), instr.Type()) + } + } + + case *Defer: + case *Extract: + case *Field: + case *FieldAddr: + case *Go: + case *Index: + case *IndexAddr: + case *Lookup: + case *MakeChan: + case *MakeClosure: + numFree := len(instr.Fn.(*Function).FreeVars) + numBind := len(instr.Bindings) + if numFree != numBind { + s.errorf("MakeClosure has %d Bindings for function %s with %d free vars", + numBind, instr.Fn, numFree) + + } + if recv := instr.Type().(*types.Signature).Recv(); recv != nil { + s.errorf("MakeClosure's type includes receiver %s", recv.Type()) + } + + case *MakeInterface: + case *MakeMap: + case *MakeSlice: + case *MapUpdate: + case *Next: + case *Range: + case *RunDefers: + case *Select: + case *Send: + case *Slice: + case *Store: + case *TypeAssert: + case *UnOp: + case *DebugRef: + // TODO(adonovan): implement checks. + default: + panic(fmt.Sprintf("Unknown instruction type: %T", instr)) + } + + if call, ok := instr.(CallInstruction); ok { + if call.Common().Signature() == nil { + s.errorf("nil signature: %s", call) + } + } + + // Check that value-defining instructions have valid types + // and a valid referrer list. + if v, ok := instr.(Value); ok { + t := v.Type() + if t == nil { + s.errorf("no type: %s = %s", v.Name(), v) + } else if t == tRangeIter { + // not a proper type; ignore. + } else if b, ok := t.Underlying().(*types.Basic); ok && b.Info()&types.IsUntyped != 0 { + s.errorf("instruction has 'untyped' result: %s = %s : %s", v.Name(), v, t) + } + s.checkReferrerList(v) + } + + // Untyped constants are legal as instruction Operands(), + // for example: + // _ = "foo"[0] + // or: + // if wordsize==64 {...} + + // All other non-Instruction Values can be found via their + // enclosing Function or Package. +} + +func (s *sanity) checkFinalInstr(instr Instruction) { + switch instr := instr.(type) { + case *If: + if nsuccs := len(s.block.Succs); nsuccs != 2 { + s.errorf("If-terminated block has %d successors; expected 2", nsuccs) + return + } + if s.block.Succs[0] == s.block.Succs[1] { + s.errorf("If-instruction has same True, False target blocks: %s", s.block.Succs[0]) + return + } + + case *Jump: + if nsuccs := len(s.block.Succs); nsuccs != 1 { + s.errorf("Jump-terminated block has %d successors; expected 1", nsuccs) + return + } + + case *Return: + if nsuccs := len(s.block.Succs); nsuccs != 0 { + s.errorf("Return-terminated block has %d successors; expected none", nsuccs) + return + } + if na, nf := len(instr.Results), s.fn.Signature.Results().Len(); nf != na { + s.errorf("%d-ary return in %d-ary function", na, nf) + } + + case *Panic: + if nsuccs := len(s.block.Succs); nsuccs != 0 { + s.errorf("Panic-terminated block has %d successors; expected none", nsuccs) + return + } + + default: + s.errorf("non-control flow instruction at end of block") + } +} + +func (s *sanity) checkBlock(b *BasicBlock, index int) { + s.block = b + + if b.Index != index { + s.errorf("block has incorrect Index %d", b.Index) + } + if b.parent != s.fn { + s.errorf("block has incorrect parent %s", b.parent) + } + + // Check all blocks are reachable. + // (The entry block is always implicitly reachable, + // as is the Recover block, if any.) + if (index > 0 && b != b.parent.Recover) && len(b.Preds) == 0 { + s.warnf("unreachable block") + if b.Instrs == nil { + // Since this block is about to be pruned, + // tolerating transient problems in it + // simplifies other optimizations. + return + } + } + + // Check predecessor and successor relations are dual, + // and that all blocks in CFG belong to same function. + for _, a := range b.Preds { + found := false + for _, bb := range a.Succs { + if bb == b { + found = true + break + } + } + if !found { + s.errorf("expected successor edge in predecessor %s; found only: %s", a, a.Succs) + } + if a.parent != s.fn { + s.errorf("predecessor %s belongs to different function %s", a, a.parent) + } + } + for _, c := range b.Succs { + found := false + for _, bb := range c.Preds { + if bb == b { + found = true + break + } + } + if !found { + s.errorf("expected predecessor edge in successor %s; found only: %s", c, c.Preds) + } + if c.parent != s.fn { + s.errorf("successor %s belongs to different function %s", c, c.parent) + } + } + + // Check each instruction is sane. + n := len(b.Instrs) + if n == 0 { + s.errorf("basic block contains no instructions") + } + var rands [10]*Value // reuse storage + for j, instr := range b.Instrs { + if instr == nil { + s.errorf("nil instruction at index %d", j) + continue + } + if b2 := instr.Block(); b2 == nil { + s.errorf("nil Block() for instruction at index %d", j) + continue + } else if b2 != b { + s.errorf("wrong Block() (%s) for instruction at index %d ", b2, j) + continue + } + if j < n-1 { + s.checkInstr(j, instr) + } else { + s.checkFinalInstr(instr) + } + + // Check Instruction.Operands. + operands: + for i, op := range instr.Operands(rands[:0]) { + if op == nil { + s.errorf("nil operand pointer %d of %s", i, instr) + continue + } + val := *op + if val == nil { + continue // a nil operand is ok + } + + // Check that "untyped" types only appear on constant operands. + if _, ok := (*op).(*Const); !ok { + if basic, ok := (*op).Type().(*types.Basic); ok { + if basic.Info()&types.IsUntyped != 0 { + s.errorf("operand #%d of %s is untyped: %s", i, instr, basic) + } + } + } + + // Check that Operands that are also Instructions belong to same function. + // TODO(adonovan): also check their block dominates block b. + if val, ok := val.(Instruction); ok { + if val.Block() == nil { + s.errorf("operand %d of %s is an instruction (%s) that belongs to no block", i, instr, val) + } else if val.Parent() != s.fn { + s.errorf("operand %d of %s is an instruction (%s) from function %s", i, instr, val, val.Parent()) + } + } + + // Check that each function-local operand of + // instr refers back to instr. (NB: quadratic) + switch val := val.(type) { + case *Const, *Global, *Builtin: + continue // not local + case *Function: + if val.parent == nil { + continue // only anon functions are local + } + } + + // TODO(adonovan): check val.Parent() != nil <=> val.Referrers() is defined. + + if refs := val.Referrers(); refs != nil { + for _, ref := range *refs { + if ref == instr { + continue operands + } + } + s.errorf("operand %d of %s (%s) does not refer to us", i, instr, val) + } else { + s.errorf("operand %d of %s (%s) has no referrers", i, instr, val) + } + } + } +} + +func (s *sanity) checkReferrerList(v Value) { + refs := v.Referrers() + if refs == nil { + s.errorf("%s has missing referrer list", v.Name()) + return + } + for i, ref := range *refs { + if _, ok := s.instrs[ref]; !ok { + s.errorf("%s.Referrers()[%d] = %s is not an instruction belonging to this function", v.Name(), i, ref) + } + } +} + +func (s *sanity) checkFunction(fn *Function) bool { + // TODO(adonovan): check Function invariants: + // - check params match signature + // - check transient fields are nil + // - warn if any fn.Locals do not appear among block instructions. + s.fn = fn + if fn.Prog == nil { + s.errorf("nil Prog") + } + + fn.String() // must not crash + fn.RelString(fn.pkg()) // must not crash + + // All functions have a package, except delegates (which are + // shared across packages, or duplicated as weak symbols in a + // separate-compilation model), and error.Error. + if fn.Pkg == nil { + if strings.HasPrefix(fn.Synthetic, "wrapper ") || + strings.HasPrefix(fn.Synthetic, "bound ") || + strings.HasPrefix(fn.Synthetic, "thunk ") || + strings.HasSuffix(fn.name, "Error") { + // ok + } else { + s.errorf("nil Pkg") + } + } + if src, syn := fn.Synthetic == "", fn.Syntax() != nil; src != syn { + s.errorf("got fromSource=%t, hasSyntax=%t; want same values", src, syn) + } + for i, l := range fn.Locals { + if l.Parent() != fn { + s.errorf("Local %s at index %d has wrong parent", l.Name(), i) + } + if l.Heap { + s.errorf("Local %s at index %d has Heap flag set", l.Name(), i) + } + } + // Build the set of valid referrers. + s.instrs = make(map[Instruction]struct{}) + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + s.instrs[instr] = struct{}{} + } + } + for i, p := range fn.Params { + if p.Parent() != fn { + s.errorf("Param %s at index %d has wrong parent", p.Name(), i) + } + s.checkReferrerList(p) + } + for i, fv := range fn.FreeVars { + if fv.Parent() != fn { + s.errorf("FreeVar %s at index %d has wrong parent", fv.Name(), i) + } + s.checkReferrerList(fv) + } + + if fn.Blocks != nil && len(fn.Blocks) == 0 { + // Function _had_ blocks (so it's not external) but + // they were "optimized" away, even the entry block. + s.errorf("Blocks slice is non-nil but empty") + } + for i, b := range fn.Blocks { + if b == nil { + s.warnf("nil *BasicBlock at f.Blocks[%d]", i) + continue + } + s.checkBlock(b, i) + } + if fn.Recover != nil && fn.Blocks[fn.Recover.Index] != fn.Recover { + s.errorf("Recover block is not in Blocks slice") + } + + s.block = nil + for i, anon := range fn.AnonFuncs { + if anon.Parent() != fn { + s.errorf("AnonFuncs[%d]=%s but %s.Parent()=%s", i, anon, anon, anon.Parent()) + } + } + s.fn = nil + return !s.insane +} + +// sanityCheckPackage checks invariants of packages upon creation. +// It does not require that the package is built. +// Unlike sanityCheck (for functions), it just panics at the first error. +func sanityCheckPackage(pkg *Package) { + if pkg.Pkg == nil { + panic(fmt.Sprintf("Package %s has no Object", pkg)) + } + pkg.String() // must not crash + + for name, mem := range pkg.Members { + if name != mem.Name() { + panic(fmt.Sprintf("%s: %T.Name() = %s, want %s", + pkg.Pkg.Path(), mem, mem.Name(), name)) + } + obj := mem.Object() + if obj == nil { + // This check is sound because fields + // {Global,Function}.object have type + // types.Object. (If they were declared as + // *types.{Var,Func}, we'd have a non-empty + // interface containing a nil pointer.) + + continue // not all members have typechecker objects + } + if obj.Name() != name { + if obj.Name() == "init" && strings.HasPrefix(mem.Name(), "init#") { + // Ok. The name of a declared init function varies between + // its types.Func ("init") and its ssa.Function ("init#%d"). + } else { + panic(fmt.Sprintf("%s: %T.Object().Name() = %s, want %s", + pkg.Pkg.Path(), mem, obj.Name(), name)) + } + } + if obj.Pos() != mem.Pos() { + panic(fmt.Sprintf("%s Pos=%d obj.Pos=%d", mem, mem.Pos(), obj.Pos())) + } + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/source.go b/vendor/golang.org/x/tools/go/ssa/source.go new file mode 100644 index 0000000..6d2223e --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/source.go @@ -0,0 +1,293 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines utilities for working with source positions +// or source-level named entities ("objects"). + +// TODO(adonovan): test that {Value,Instruction}.Pos() positions match +// the originating syntax, as specified. + +import ( + "go/ast" + "go/token" + "go/types" +) + +// EnclosingFunction returns the function that contains the syntax +// node denoted by path. +// +// Syntax associated with package-level variable specifications is +// enclosed by the package's init() function. +// +// Returns nil if not found; reasons might include: +// - the node is not enclosed by any function. +// - the node is within an anonymous function (FuncLit) and +// its SSA function has not been created yet +// (pkg.Build() has not yet been called). +// +func EnclosingFunction(pkg *Package, path []ast.Node) *Function { + // Start with package-level function... + fn := findEnclosingPackageLevelFunction(pkg, path) + if fn == nil { + return nil // not in any function + } + + // ...then walk down the nested anonymous functions. + n := len(path) +outer: + for i := range path { + if lit, ok := path[n-1-i].(*ast.FuncLit); ok { + for _, anon := range fn.AnonFuncs { + if anon.Pos() == lit.Type.Func { + fn = anon + continue outer + } + } + // SSA function not found: + // - package not yet built, or maybe + // - builder skipped FuncLit in dead block + // (in principle; but currently the Builder + // generates even dead FuncLits). + return nil + } + } + return fn +} + +// HasEnclosingFunction returns true if the AST node denoted by path +// is contained within the declaration of some function or +// package-level variable. +// +// Unlike EnclosingFunction, the behaviour of this function does not +// depend on whether SSA code for pkg has been built, so it can be +// used to quickly reject check inputs that will cause +// EnclosingFunction to fail, prior to SSA building. +// +func HasEnclosingFunction(pkg *Package, path []ast.Node) bool { + return findEnclosingPackageLevelFunction(pkg, path) != nil +} + +// findEnclosingPackageLevelFunction returns the Function +// corresponding to the package-level function enclosing path. +// +func findEnclosingPackageLevelFunction(pkg *Package, path []ast.Node) *Function { + if n := len(path); n >= 2 { // [... {Gen,Func}Decl File] + switch decl := path[n-2].(type) { + case *ast.GenDecl: + if decl.Tok == token.VAR && n >= 3 { + // Package-level 'var' initializer. + return pkg.init + } + + case *ast.FuncDecl: + if decl.Recv == nil && decl.Name.Name == "init" { + // Explicit init() function. + for _, b := range pkg.init.Blocks { + for _, instr := range b.Instrs { + if instr, ok := instr.(*Call); ok { + if callee, ok := instr.Call.Value.(*Function); ok && callee.Pkg == pkg && callee.Pos() == decl.Name.NamePos { + return callee + } + } + } + } + // Hack: return non-nil when SSA is not yet + // built so that HasEnclosingFunction works. + return pkg.init + } + // Declared function/method. + return findNamedFunc(pkg, decl.Name.NamePos) + } + } + return nil // not in any function +} + +// findNamedFunc returns the named function whose FuncDecl.Ident is at +// position pos. +// +func findNamedFunc(pkg *Package, pos token.Pos) *Function { + // Look at all package members and method sets of named types. + // Not very efficient. + for _, mem := range pkg.Members { + switch mem := mem.(type) { + case *Function: + if mem.Pos() == pos { + return mem + } + case *Type: + mset := pkg.Prog.MethodSets.MethodSet(types.NewPointer(mem.Type())) + for i, n := 0, mset.Len(); i < n; i++ { + // Don't call Program.Method: avoid creating wrappers. + obj := mset.At(i).Obj().(*types.Func) + if obj.Pos() == pos { + return pkg.values[obj].(*Function) + } + } + } + } + return nil +} + +// ValueForExpr returns the SSA Value that corresponds to non-constant +// expression e. +// +// It returns nil if no value was found, e.g. +// - the expression is not lexically contained within f; +// - f was not built with debug information; or +// - e is a constant expression. (For efficiency, no debug +// information is stored for constants. Use +// go/types.Info.Types[e].Value instead.) +// - e is a reference to nil or a built-in function. +// - the value was optimised away. +// +// If e is an addressable expression used in an lvalue context, +// value is the address denoted by e, and isAddr is true. +// +// The types of e (or &e, if isAddr) and the result are equal +// (modulo "untyped" bools resulting from comparisons). +// +// (Tip: to find the ssa.Value given a source position, use +// importer.PathEnclosingInterval to locate the ast.Node, then +// EnclosingFunction to locate the Function, then ValueForExpr to find +// the ssa.Value.) +// +func (f *Function) ValueForExpr(e ast.Expr) (value Value, isAddr bool) { + if f.debugInfo() { // (opt) + e = unparen(e) + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + if ref, ok := instr.(*DebugRef); ok { + if ref.Expr == e { + return ref.X, ref.IsAddr + } + } + } + } + } + return +} + +// --- Lookup functions for source-level named entities (types.Objects) --- + +// Package returns the SSA Package corresponding to the specified +// type-checker package object. +// It returns nil if no such SSA package has been created. +// +func (prog *Program) Package(obj *types.Package) *Package { + return prog.packages[obj] +} + +// packageLevelValue returns the package-level value corresponding to +// the specified named object, which may be a package-level const +// (*Const), var (*Global) or func (*Function) of some package in +// prog. It returns nil if the object is not found. +// +func (prog *Program) packageLevelValue(obj types.Object) Value { + if pkg, ok := prog.packages[obj.Pkg()]; ok { + return pkg.values[obj] + } + return nil +} + +// FuncValue returns the concrete Function denoted by the source-level +// named function obj, or nil if obj denotes an interface method. +// +// TODO(adonovan): check the invariant that obj.Type() matches the +// result's Signature, both in the params/results and in the receiver. +// +func (prog *Program) FuncValue(obj *types.Func) *Function { + fn, _ := prog.packageLevelValue(obj).(*Function) + return fn +} + +// ConstValue returns the SSA Value denoted by the source-level named +// constant obj. +// +func (prog *Program) ConstValue(obj *types.Const) *Const { + // TODO(adonovan): opt: share (don't reallocate) + // Consts for const objects and constant ast.Exprs. + + // Universal constant? {true,false,nil} + if obj.Parent() == types.Universe { + return NewConst(obj.Val(), obj.Type()) + } + // Package-level named constant? + if v := prog.packageLevelValue(obj); v != nil { + return v.(*Const) + } + return NewConst(obj.Val(), obj.Type()) +} + +// VarValue returns the SSA Value that corresponds to a specific +// identifier denoting the source-level named variable obj. +// +// VarValue returns nil if a local variable was not found, perhaps +// because its package was not built, the debug information was not +// requested during SSA construction, or the value was optimized away. +// +// ref is the path to an ast.Ident (e.g. from PathEnclosingInterval), +// and that ident must resolve to obj. +// +// pkg is the package enclosing the reference. (A reference to a var +// always occurs within a function, so we need to know where to find it.) +// +// If the identifier is a field selector and its base expression is +// non-addressable, then VarValue returns the value of that field. +// For example: +// func f() struct {x int} +// f().x // VarValue(x) returns a *Field instruction of type int +// +// All other identifiers denote addressable locations (variables). +// For them, VarValue may return either the variable's address or its +// value, even when the expression is evaluated only for its value; the +// situation is reported by isAddr, the second component of the result. +// +// If !isAddr, the returned value is the one associated with the +// specific identifier. For example, +// var x int // VarValue(x) returns Const 0 here +// x = 1 // VarValue(x) returns Const 1 here +// +// It is not specified whether the value or the address is returned in +// any particular case, as it may depend upon optimizations performed +// during SSA code generation, such as registerization, constant +// folding, avoidance of materialization of subexpressions, etc. +// +func (prog *Program) VarValue(obj *types.Var, pkg *Package, ref []ast.Node) (value Value, isAddr bool) { + // All references to a var are local to some function, possibly init. + fn := EnclosingFunction(pkg, ref) + if fn == nil { + return // e.g. def of struct field; SSA not built? + } + + id := ref[0].(*ast.Ident) + + // Defining ident of a parameter? + if id.Pos() == obj.Pos() { + for _, param := range fn.Params { + if param.Object() == obj { + return param, false + } + } + } + + // Other ident? + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + if dr, ok := instr.(*DebugRef); ok { + if dr.Pos() == id.Pos() { + return dr.X, dr.IsAddr + } + } + } + } + + // Defining ident of package-level var? + if v := prog.packageLevelValue(obj); v != nil { + return v.(*Global), true + } + + return // e.g. debug info not requested, or var optimized away +} diff --git a/vendor/golang.org/x/tools/go/ssa/source_test.go b/vendor/golang.org/x/tools/go/ssa/source_test.go new file mode 100644 index 0000000..43051f8 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/source_test.go @@ -0,0 +1,397 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa_test + +// This file defines tests of source-level debugging utilities. + +import ( + "fmt" + "go/ast" + exact "go/constant" + "go/parser" + "go/token" + "go/types" + "os" + "regexp" + "runtime" + "strings" + "testing" + + "golang.org/x/tools/go/ast/astutil" + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +func TestObjValueLookup(t *testing.T) { + if runtime.GOOS == "android" { + t.Skipf("no testdata directory on %s", runtime.GOOS) + } + + conf := loader.Config{ParserMode: parser.ParseComments} + f, err := conf.ParseFile("testdata/objlookup.go", nil) + if err != nil { + t.Error(err) + return + } + conf.CreateFromFiles("main", f) + + // Maps each var Ident (represented "name:linenum") to the + // kind of ssa.Value we expect (represented "Constant", "&Alloc"). + expectations := make(map[string]string) + + // Find all annotations of form x::BinOp, &y::Alloc, etc. + re := regexp.MustCompile(`(\b|&)?(\w*)::(\w*)\b`) + for _, c := range f.Comments { + text := c.Text() + pos := conf.Fset.Position(c.Pos()) + for _, m := range re.FindAllStringSubmatch(text, -1) { + key := fmt.Sprintf("%s:%d", m[2], pos.Line) + value := m[1] + m[3] + expectations[key] = value + } + } + + iprog, err := conf.Load() + if err != nil { + t.Error(err) + return + } + + prog := ssautil.CreateProgram(iprog, 0 /*|ssa.PrintFunctions*/) + mainInfo := iprog.Created[0] + mainPkg := prog.Package(mainInfo.Pkg) + mainPkg.SetDebugMode(true) + mainPkg.Build() + + var varIds []*ast.Ident + var varObjs []*types.Var + for id, obj := range mainInfo.Defs { + // Check invariants for func and const objects. + switch obj := obj.(type) { + case *types.Func: + checkFuncValue(t, prog, obj) + + case *types.Const: + checkConstValue(t, prog, obj) + + case *types.Var: + if id.Name == "_" { + continue + } + varIds = append(varIds, id) + varObjs = append(varObjs, obj) + } + } + for id, obj := range mainInfo.Uses { + if obj, ok := obj.(*types.Var); ok { + varIds = append(varIds, id) + varObjs = append(varObjs, obj) + } + } + + // Check invariants for var objects. + // The result varies based on the specific Ident. + for i, id := range varIds { + obj := varObjs[i] + ref, _ := astutil.PathEnclosingInterval(f, id.Pos(), id.Pos()) + pos := prog.Fset.Position(id.Pos()) + exp := expectations[fmt.Sprintf("%s:%d", id.Name, pos.Line)] + if exp == "" { + t.Errorf("%s: no expectation for var ident %s ", pos, id.Name) + continue + } + wantAddr := false + if exp[0] == '&' { + wantAddr = true + exp = exp[1:] + } + checkVarValue(t, prog, mainPkg, ref, obj, exp, wantAddr) + } +} + +func checkFuncValue(t *testing.T, prog *ssa.Program, obj *types.Func) { + fn := prog.FuncValue(obj) + // fmt.Printf("FuncValue(%s) = %s\n", obj, fn) // debugging + if fn == nil { + if obj.Name() != "interfaceMethod" { + t.Errorf("FuncValue(%s) == nil", obj) + } + return + } + if fnobj := fn.Object(); fnobj != obj { + t.Errorf("FuncValue(%s).Object() == %s; value was %s", + obj, fnobj, fn.Name()) + return + } + if !types.Identical(fn.Type(), obj.Type()) { + t.Errorf("FuncValue(%s).Type() == %s", obj, fn.Type()) + return + } +} + +func checkConstValue(t *testing.T, prog *ssa.Program, obj *types.Const) { + c := prog.ConstValue(obj) + // fmt.Printf("ConstValue(%s) = %s\n", obj, c) // debugging + if c == nil { + t.Errorf("ConstValue(%s) == nil", obj) + return + } + if !types.Identical(c.Type(), obj.Type()) { + t.Errorf("ConstValue(%s).Type() == %s", obj, c.Type()) + return + } + if obj.Name() != "nil" { + if !exact.Compare(c.Value, token.EQL, obj.Val()) { + t.Errorf("ConstValue(%s).Value (%s) != %s", + obj, c.Value, obj.Val()) + return + } + } +} + +func checkVarValue(t *testing.T, prog *ssa.Program, pkg *ssa.Package, ref []ast.Node, obj *types.Var, expKind string, wantAddr bool) { + // The prefix of all assertions messages. + prefix := fmt.Sprintf("VarValue(%s @ L%d)", + obj, prog.Fset.Position(ref[0].Pos()).Line) + + v, gotAddr := prog.VarValue(obj, pkg, ref) + + // Kind is the concrete type of the ssa Value. + gotKind := "nil" + if v != nil { + gotKind = fmt.Sprintf("%T", v)[len("*ssa."):] + } + + // fmt.Printf("%s = %v (kind %q; expect %q) wantAddr=%t gotAddr=%t\n", prefix, v, gotKind, expKind, wantAddr, gotAddr) // debugging + + // Check the kinds match. + // "nil" indicates expected failure (e.g. optimized away). + if expKind != gotKind { + t.Errorf("%s concrete type == %s, want %s", prefix, gotKind, expKind) + } + + // Check the types match. + // If wantAddr, the expected type is the object's address. + if v != nil { + expType := obj.Type() + if wantAddr { + expType = types.NewPointer(expType) + if !gotAddr { + t.Errorf("%s: got value, want address", prefix) + } + } else if gotAddr { + t.Errorf("%s: got address, want value", prefix) + } + if !types.Identical(v.Type(), expType) { + t.Errorf("%s.Type() == %s, want %s", prefix, v.Type(), expType) + } + } +} + +// Ensure that, in debug mode, we can determine the ssa.Value +// corresponding to every ast.Expr. +func TestValueForExpr(t *testing.T) { + testValueForExpr(t, "testdata/valueforexpr.go") +} + +func testValueForExpr(t *testing.T, testfile string) { + if runtime.GOOS == "android" { + t.Skipf("no testdata dir on %s", runtime.GOOS) + } + + conf := loader.Config{ParserMode: parser.ParseComments} + f, err := conf.ParseFile(testfile, nil) + if err != nil { + t.Error(err) + return + } + conf.CreateFromFiles("main", f) + + iprog, err := conf.Load() + if err != nil { + t.Error(err) + return + } + + mainInfo := iprog.Created[0] + + prog := ssautil.CreateProgram(iprog, 0) + mainPkg := prog.Package(mainInfo.Pkg) + mainPkg.SetDebugMode(true) + mainPkg.Build() + + if false { + // debugging + for _, mem := range mainPkg.Members { + if fn, ok := mem.(*ssa.Function); ok { + fn.WriteTo(os.Stderr) + } + } + } + + // Find the actual AST node for each canonical position. + parenExprByPos := make(map[token.Pos]*ast.ParenExpr) + ast.Inspect(f, func(n ast.Node) bool { + if n != nil { + if e, ok := n.(*ast.ParenExpr); ok { + parenExprByPos[e.Pos()] = e + } + } + return true + }) + + // Find all annotations of form /*@kind*/. + for _, c := range f.Comments { + text := strings.TrimSpace(c.Text()) + if text == "" || text[0] != '@' { + continue + } + text = text[1:] + pos := c.End() + 1 + position := prog.Fset.Position(pos) + var e ast.Expr + if target := parenExprByPos[pos]; target == nil { + t.Errorf("%s: annotation doesn't precede ParenExpr: %q", position, text) + continue + } else { + e = target.X + } + + path, _ := astutil.PathEnclosingInterval(f, pos, pos) + if path == nil { + t.Errorf("%s: can't find AST path from root to comment: %s", position, text) + continue + } + + fn := ssa.EnclosingFunction(mainPkg, path) + if fn == nil { + t.Errorf("%s: can't find enclosing function", position) + continue + } + + v, gotAddr := fn.ValueForExpr(e) // (may be nil) + got := strings.TrimPrefix(fmt.Sprintf("%T", v), "*ssa.") + if want := text; got != want { + t.Errorf("%s: got value %q, want %q", position, got, want) + } + if v != nil { + T := v.Type() + if gotAddr { + T = T.Underlying().(*types.Pointer).Elem() // deref + } + if !types.Identical(T, mainInfo.TypeOf(e)) { + t.Errorf("%s: got type %s, want %s", position, mainInfo.TypeOf(e), T) + } + } + } +} + +// findInterval parses input and returns the [start, end) positions of +// the first occurrence of substr in input. f==nil indicates failure; +// an error has already been reported in that case. +// +func findInterval(t *testing.T, fset *token.FileSet, input, substr string) (f *ast.File, start, end token.Pos) { + f, err := parser.ParseFile(fset, "<input>", input, 0) + if err != nil { + t.Errorf("parse error: %s", err) + return + } + + i := strings.Index(input, substr) + if i < 0 { + t.Errorf("%q is not a substring of input", substr) + f = nil + return + } + + filePos := fset.File(f.Package) + return f, filePos.Pos(i), filePos.Pos(i + len(substr)) +} + +func TestEnclosingFunction(t *testing.T) { + tests := []struct { + input string // the input file + substr string // first occurrence of this string denotes interval + fn string // name of expected containing function + }{ + // We use distinctive numbers as syntactic landmarks. + + // Ordinary function: + {`package main + func f() { println(1003) }`, + "100", "main.f"}, + // Methods: + {`package main + type T int + func (t T) f() { println(200) }`, + "200", "(main.T).f"}, + // Function literal: + {`package main + func f() { println(func() { print(300) }) }`, + "300", "main.f$1"}, + // Doubly nested + {`package main + func f() { println(func() { print(func() { print(350) })})}`, + "350", "main.f$1$1"}, + // Implicit init for package-level var initializer. + {"package main; var a = 400", "400", "main.init"}, + // No code for constants: + {"package main; const a = 500", "500", "(none)"}, + // Explicit init() + {"package main; func init() { println(600) }", "600", "main.init#1"}, + // Multiple explicit init functions: + {`package main + func init() { println("foo") } + func init() { println(800) }`, + "800", "main.init#2"}, + // init() containing FuncLit. + {`package main + func init() { println(func(){print(900)}) }`, + "900", "main.init#1$1"}, + } + for _, test := range tests { + conf := loader.Config{Fset: token.NewFileSet()} + f, start, end := findInterval(t, conf.Fset, test.input, test.substr) + if f == nil { + continue + } + path, exact := astutil.PathEnclosingInterval(f, start, end) + if !exact { + t.Errorf("EnclosingFunction(%q) not exact", test.substr) + continue + } + + conf.CreateFromFiles("main", f) + + iprog, err := conf.Load() + if err != nil { + t.Error(err) + continue + } + prog := ssautil.CreateProgram(iprog, 0) + pkg := prog.Package(iprog.Created[0].Pkg) + pkg.Build() + + name := "(none)" + fn := ssa.EnclosingFunction(pkg, path) + if fn != nil { + name = fn.String() + } + + if name != test.fn { + t.Errorf("EnclosingFunction(%q in %q) got %s, want %s", + test.substr, test.input, name, test.fn) + continue + } + + // While we're here: test HasEnclosingFunction. + if has := ssa.HasEnclosingFunction(pkg, path); has != (fn != nil) { + t.Errorf("HasEnclosingFunction(%q in %q) got %v, want %v", + test.substr, test.input, has, fn != nil) + continue + } + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssa.go b/vendor/golang.org/x/tools/go/ssa/ssa.go new file mode 100644 index 0000000..e8350f1 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssa.go @@ -0,0 +1,1696 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This package defines a high-level intermediate representation for +// Go programs using static single-assignment (SSA) form. + +import ( + "fmt" + "go/ast" + exact "go/constant" + "go/token" + "go/types" + "sync" + + "golang.org/x/tools/go/types/typeutil" +) + +// A Program is a partial or complete Go program converted to SSA form. +type Program struct { + Fset *token.FileSet // position information for the files of this Program + imported map[string]*Package // all importable Packages, keyed by import path + packages map[*types.Package]*Package // all loaded Packages, keyed by object + mode BuilderMode // set of mode bits for SSA construction + MethodSets typeutil.MethodSetCache // cache of type-checker's method-sets + + methodsMu sync.Mutex // guards the following maps: + methodSets typeutil.Map // maps type to its concrete methodSet + runtimeTypes typeutil.Map // types for which rtypes are needed + canon typeutil.Map // type canonicalization map + bounds map[*types.Func]*Function // bounds for curried x.Method closures + thunks map[selectionKey]*Function // thunks for T.Method expressions +} + +// A Package is a single analyzed Go package containing Members for +// all package-level functions, variables, constants and types it +// declares. These may be accessed directly via Members, or via the +// type-specific accessor methods Func, Type, Var and Const. +// +// Members also contains entries for "init" (the synthetic package +// initializer) and "init#%d", the nth declared init function, +// and unspecified other things too. +// +type Package struct { + Prog *Program // the owning program + Pkg *types.Package // the corresponding go/types.Package + Members map[string]Member // all package members keyed by name (incl. init and init#%d) + values map[types.Object]Value // package members (incl. types and methods), keyed by object + init *Function // Func("init"); the package's init function + debug bool // include full debug info in this package + + // The following fields are set transiently, then cleared + // after building. + buildOnce sync.Once // ensures package building occurs once + ninit int32 // number of init functions + info *types.Info // package type information + files []*ast.File // package ASTs +} + +// A Member is a member of a Go package, implemented by *NamedConst, +// *Global, *Function, or *Type; they are created by package-level +// const, var, func and type declarations respectively. +// +type Member interface { + Name() string // declared name of the package member + String() string // package-qualified name of the package member + RelString(*types.Package) string // like String, but relative refs are unqualified + Object() types.Object // typechecker's object for this member, if any + Pos() token.Pos // position of member's declaration, if known + Type() types.Type // type of the package member + Token() token.Token // token.{VAR,FUNC,CONST,TYPE} + Package() *Package // the containing package +} + +// A Type is a Member of a Package representing a package-level named type. +type Type struct { + object *types.TypeName + pkg *Package +} + +// A NamedConst is a Member of a Package representing a package-level +// named constant. +// +// Pos() returns the position of the declaring ast.ValueSpec.Names[*] +// identifier. +// +// NB: a NamedConst is not a Value; it contains a constant Value, which +// it augments with the name and position of its 'const' declaration. +// +type NamedConst struct { + object *types.Const + Value *Const + pkg *Package +} + +// A Value is an SSA value that can be referenced by an instruction. +type Value interface { + // Name returns the name of this value, and determines how + // this Value appears when used as an operand of an + // Instruction. + // + // This is the same as the source name for Parameters, + // Builtins, Functions, FreeVars, Globals. + // For constants, it is a representation of the constant's value + // and type. For all other Values this is the name of the + // virtual register defined by the instruction. + // + // The name of an SSA Value is not semantically significant, + // and may not even be unique within a function. + Name() string + + // If this value is an Instruction, String returns its + // disassembled form; otherwise it returns unspecified + // human-readable information about the Value, such as its + // kind, name and type. + String() string + + // Type returns the type of this value. Many instructions + // (e.g. IndexAddr) change their behaviour depending on the + // types of their operands. + Type() types.Type + + // Parent returns the function to which this Value belongs. + // It returns nil for named Functions, Builtin, Const and Global. + Parent() *Function + + // Referrers returns the list of instructions that have this + // value as one of their operands; it may contain duplicates + // if an instruction has a repeated operand. + // + // Referrers actually returns a pointer through which the + // caller may perform mutations to the object's state. + // + // Referrers is currently only defined if Parent()!=nil, + // i.e. for the function-local values FreeVar, Parameter, + // Functions (iff anonymous) and all value-defining instructions. + // It returns nil for named Functions, Builtin, Const and Global. + // + // Instruction.Operands contains the inverse of this relation. + Referrers() *[]Instruction + + // Pos returns the location of the AST token most closely + // associated with the operation that gave rise to this value, + // or token.NoPos if it was not explicit in the source. + // + // For each ast.Node type, a particular token is designated as + // the closest location for the expression, e.g. the Lparen + // for an *ast.CallExpr. This permits a compact but + // approximate mapping from Values to source positions for use + // in diagnostic messages, for example. + // + // (Do not use this position to determine which Value + // corresponds to an ast.Expr; use Function.ValueForExpr + // instead. NB: it requires that the function was built with + // debug information.) + Pos() token.Pos +} + +// An Instruction is an SSA instruction that computes a new Value or +// has some effect. +// +// An Instruction that defines a value (e.g. BinOp) also implements +// the Value interface; an Instruction that only has an effect (e.g. Store) +// does not. +// +type Instruction interface { + // String returns the disassembled form of this value. + // + // Examples of Instructions that are Values: + // "x + y" (BinOp) + // "len([])" (Call) + // Note that the name of the Value is not printed. + // + // Examples of Instructions that are not Values: + // "return x" (Return) + // "*y = x" (Store) + // + // (The separation Value.Name() from Value.String() is useful + // for some analyses which distinguish the operation from the + // value it defines, e.g., 'y = local int' is both an allocation + // of memory 'local int' and a definition of a pointer y.) + String() string + + // Parent returns the function to which this instruction + // belongs. + Parent() *Function + + // Block returns the basic block to which this instruction + // belongs. + Block() *BasicBlock + + // setBlock sets the basic block to which this instruction belongs. + setBlock(*BasicBlock) + + // Operands returns the operands of this instruction: the + // set of Values it references. + // + // Specifically, it appends their addresses to rands, a + // user-provided slice, and returns the resulting slice, + // permitting avoidance of memory allocation. + // + // The operands are appended in undefined order, but the order + // is consistent for a given Instruction; the addresses are + // always non-nil but may point to a nil Value. Clients may + // store through the pointers, e.g. to effect a value + // renaming. + // + // Value.Referrers is a subset of the inverse of this + // relation. (Referrers are not tracked for all types of + // Values.) + Operands(rands []*Value) []*Value + + // Pos returns the location of the AST token most closely + // associated with the operation that gave rise to this + // instruction, or token.NoPos if it was not explicit in the + // source. + // + // For each ast.Node type, a particular token is designated as + // the closest location for the expression, e.g. the Go token + // for an *ast.GoStmt. This permits a compact but approximate + // mapping from Instructions to source positions for use in + // diagnostic messages, for example. + // + // (Do not use this position to determine which Instruction + // corresponds to an ast.Expr; see the notes for Value.Pos. + // This position may be used to determine which non-Value + // Instruction corresponds to some ast.Stmts, but not all: If + // and Jump instructions have no Pos(), for example.) + Pos() token.Pos +} + +// A Node is a node in the SSA value graph. Every concrete type that +// implements Node is also either a Value, an Instruction, or both. +// +// Node contains the methods common to Value and Instruction, plus the +// Operands and Referrers methods generalized to return nil for +// non-Instructions and non-Values, respectively. +// +// Node is provided to simplify SSA graph algorithms. Clients should +// use the more specific and informative Value or Instruction +// interfaces where appropriate. +// +type Node interface { + // Common methods: + String() string + Pos() token.Pos + Parent() *Function + + // Partial methods: + Operands(rands []*Value) []*Value // nil for non-Instructions + Referrers() *[]Instruction // nil for non-Values +} + +// Function represents the parameters, results, and code of a function +// or method. +// +// If Blocks is nil, this indicates an external function for which no +// Go source code is available. In this case, FreeVars and Locals +// are nil too. Clients performing whole-program analysis must +// handle external functions specially. +// +// Blocks contains the function's control-flow graph (CFG). +// Blocks[0] is the function entry point; block order is not otherwise +// semantically significant, though it may affect the readability of +// the disassembly. +// To iterate over the blocks in dominance order, use DomPreorder(). +// +// Recover is an optional second entry point to which control resumes +// after a recovered panic. The Recover block may contain only a return +// statement, preceded by a load of the function's named return +// parameters, if any. +// +// A nested function (Parent()!=nil) that refers to one or more +// lexically enclosing local variables ("free variables") has FreeVars. +// Such functions cannot be called directly but require a +// value created by MakeClosure which, via its Bindings, supplies +// values for these parameters. +// +// If the function is a method (Signature.Recv() != nil) then the first +// element of Params is the receiver parameter. +// +// A Go package may declare many functions called "init". +// For each one, Object().Name() returns "init" but Name() returns +// "init#1", etc, in declaration order. +// +// Pos() returns the declaring ast.FuncLit.Type.Func or the position +// of the ast.FuncDecl.Name, if the function was explicit in the +// source. Synthetic wrappers, for which Synthetic != "", may share +// the same position as the function they wrap. +// Syntax.Pos() always returns the position of the declaring "func" token. +// +// Type() returns the function's Signature. +// +type Function struct { + name string + object types.Object // a declared *types.Func or one of its wrappers + method *types.Selection // info about provenance of synthetic methods + Signature *types.Signature + pos token.Pos + + Synthetic string // provenance of synthetic function; "" for true source functions + syntax ast.Node // *ast.Func{Decl,Lit}; replaced with simple ast.Node after build, unless debug mode + parent *Function // enclosing function if anon; nil if global + Pkg *Package // enclosing package; nil for shared funcs (wrappers and error.Error) + Prog *Program // enclosing program + Params []*Parameter // function parameters; for methods, includes receiver + FreeVars []*FreeVar // free variables whose values must be supplied by closure + Locals []*Alloc // local variables of this function + Blocks []*BasicBlock // basic blocks of the function; nil => external + Recover *BasicBlock // optional; control transfers here after recovered panic + AnonFuncs []*Function // anonymous functions directly beneath this one + referrers []Instruction // referring instructions (iff Parent() != nil) + + // The following fields are set transiently during building, + // then cleared. + currentBlock *BasicBlock // where to emit code + objects map[types.Object]Value // addresses of local variables + namedResults []*Alloc // tuple of named results + targets *targets // linked stack of branch targets + lblocks map[*ast.Object]*lblock // labelled blocks +} + +// BasicBlock represents an SSA basic block. +// +// The final element of Instrs is always an explicit transfer of +// control (If, Jump, Return, or Panic). +// +// A block may contain no Instructions only if it is unreachable, +// i.e., Preds is nil. Empty blocks are typically pruned. +// +// BasicBlocks and their Preds/Succs relation form a (possibly cyclic) +// graph independent of the SSA Value graph: the control-flow graph or +// CFG. It is illegal for multiple edges to exist between the same +// pair of blocks. +// +// Each BasicBlock is also a node in the dominator tree of the CFG. +// The tree may be navigated using Idom()/Dominees() and queried using +// Dominates(). +// +// The order of Preds and Succs is significant (to Phi and If +// instructions, respectively). +// +type BasicBlock struct { + Index int // index of this block within Parent().Blocks + Comment string // optional label; no semantic significance + parent *Function // parent function + Instrs []Instruction // instructions in order + Preds, Succs []*BasicBlock // predecessors and successors + succs2 [2]*BasicBlock // initial space for Succs + dom domInfo // dominator tree info + gaps int // number of nil Instrs (transient) + rundefers int // number of rundefers (transient) +} + +// Pure values ---------------------------------------- + +// A FreeVar represents a free variable of the function to which it +// belongs. +// +// FreeVars are used to implement anonymous functions, whose free +// variables are lexically captured in a closure formed by +// MakeClosure. The value of such a free var is an Alloc or another +// FreeVar and is considered a potentially escaping heap address, with +// pointer type. +// +// FreeVars are also used to implement bound method closures. Such a +// free var represents the receiver value and may be of any type that +// has concrete methods. +// +// Pos() returns the position of the value that was captured, which +// belongs to an enclosing function. +// +type FreeVar struct { + name string + typ types.Type + pos token.Pos + parent *Function + referrers []Instruction + + // Transiently needed during building. + outer Value // the Value captured from the enclosing context. +} + +// A Parameter represents an input parameter of a function. +// +type Parameter struct { + name string + object types.Object // a *types.Var; nil for non-source locals + typ types.Type + pos token.Pos + parent *Function + referrers []Instruction +} + +// A Const represents the value of a constant expression. +// +// The underlying type of a constant may be any boolean, numeric, or +// string type. In addition, a Const may represent the nil value of +// any reference type---interface, map, channel, pointer, slice, or +// function---but not "untyped nil". +// +// All source-level constant expressions are represented by a Const +// of the same type and value. +// +// Value holds the exact value of the constant, independent of its +// Type(), using the same representation as package go/exact uses for +// constants, or nil for a typed nil value. +// +// Pos() returns token.NoPos. +// +// Example printed form: +// 42:int +// "hello":untyped string +// 3+4i:MyComplex +// +type Const struct { + typ types.Type + Value exact.Value +} + +// A Global is a named Value holding the address of a package-level +// variable. +// +// Pos() returns the position of the ast.ValueSpec.Names[*] +// identifier. +// +type Global struct { + name string + object types.Object // a *types.Var; may be nil for synthetics e.g. init$guard + typ types.Type + pos token.Pos + + Pkg *Package +} + +// A Builtin represents a specific use of a built-in function, e.g. len. +// +// Builtins are immutable values. Builtins do not have addresses. +// Builtins can only appear in CallCommon.Func. +// +// Name() indicates the function: one of the built-in functions from the +// Go spec (excluding "make" and "new") or one of these ssa-defined +// intrinsics: +// +// // wrapnilchk returns ptr if non-nil, panics otherwise. +// // (For use in indirection wrappers.) +// func ssa:wrapnilchk(ptr *T, recvType, methodName string) *T +// +// Object() returns a *types.Builtin for built-ins defined by the spec, +// nil for others. +// +// Type() returns a *types.Signature representing the effective +// signature of the built-in for this call. +// +type Builtin struct { + name string + sig *types.Signature +} + +// Value-defining instructions ---------------------------------------- + +// The Alloc instruction reserves space for a variable of the given type, +// zero-initializes it, and yields its address. +// +// Alloc values are always addresses, and have pointer types, so the +// type of the allocated variable is actually +// Type().Underlying().(*types.Pointer).Elem(). +// +// If Heap is false, Alloc allocates space in the function's +// activation record (frame); we refer to an Alloc(Heap=false) as a +// "local" alloc. Each local Alloc returns the same address each time +// it is executed within the same activation; the space is +// re-initialized to zero. +// +// If Heap is true, Alloc allocates space in the heap; we +// refer to an Alloc(Heap=true) as a "new" alloc. Each new Alloc +// returns a different address each time it is executed. +// +// When Alloc is applied to a channel, map or slice type, it returns +// the address of an uninitialized (nil) reference of that kind; store +// the result of MakeSlice, MakeMap or MakeChan in that location to +// instantiate these types. +// +// Pos() returns the ast.CompositeLit.Lbrace for a composite literal, +// or the ast.CallExpr.Rparen for a call to new() or for a call that +// allocates a varargs slice. +// +// Example printed form: +// t0 = local int +// t1 = new int +// +type Alloc struct { + register + Comment string + Heap bool + index int // dense numbering; for lifting +} + +// The Phi instruction represents an SSA φ-node, which combines values +// that differ across incoming control-flow edges and yields a new +// value. Within a block, all φ-nodes must appear before all non-φ +// nodes. +// +// Pos() returns the position of the && or || for short-circuit +// control-flow joins, or that of the *Alloc for φ-nodes inserted +// during SSA renaming. +// +// Example printed form: +// t2 = phi [0: t0, 1: t1] +// +type Phi struct { + register + Comment string // a hint as to its purpose + Edges []Value // Edges[i] is value for Block().Preds[i] +} + +// The Call instruction represents a function or method call. +// +// The Call instruction yields the function result if there is exactly +// one. Otherwise it returns a tuple, the components of which are +// accessed via Extract. +// +// See CallCommon for generic function call documentation. +// +// Pos() returns the ast.CallExpr.Lparen, if explicit in the source. +// +// Example printed form: +// t2 = println(t0, t1) +// t4 = t3() +// t7 = invoke t5.Println(...t6) +// +type Call struct { + register + Call CallCommon +} + +// The BinOp instruction yields the result of binary operation X Op Y. +// +// Pos() returns the ast.BinaryExpr.OpPos, if explicit in the source. +// +// Example printed form: +// t1 = t0 + 1:int +// +type BinOp struct { + register + // One of: + // ADD SUB MUL QUO REM + - * / % + // AND OR XOR SHL SHR AND_NOT & | ^ << >> &~ + // EQL LSS GTR NEQ LEQ GEQ == != < <= < >= + Op token.Token + X, Y Value +} + +// The UnOp instruction yields the result of Op X. +// ARROW is channel receive. +// MUL is pointer indirection (load). +// XOR is bitwise complement. +// SUB is negation. +// NOT is logical negation. +// +// If CommaOk and Op=ARROW, the result is a 2-tuple of the value above +// and a boolean indicating the success of the receive. The +// components of the tuple are accessed using Extract. +// +// Pos() returns the ast.UnaryExpr.OpPos, if explicit in the source. +// For receive operations (ARROW) implicit in ranging over a channel, +// Pos() returns the ast.RangeStmt.For. +// For implicit memory loads (STAR), Pos() returns the position of the +// most closely associated source-level construct; the details are not +// specified. +// +// Example printed form: +// t0 = *x +// t2 = <-t1,ok +// +type UnOp struct { + register + Op token.Token // One of: NOT SUB ARROW MUL XOR ! - <- * ^ + X Value + CommaOk bool +} + +// The ChangeType instruction applies to X a value-preserving type +// change to Type(). +// +// Type changes are permitted: +// - between a named type and its underlying type. +// - between two named types of the same underlying type. +// - between (possibly named) pointers to identical base types. +// - from a bidirectional channel to a read- or write-channel, +// optionally adding/removing a name. +// +// This operation cannot fail dynamically. +// +// Pos() returns the ast.CallExpr.Lparen, if the instruction arose +// from an explicit conversion in the source. +// +// Example printed form: +// t1 = changetype *int <- IntPtr (t0) +// +type ChangeType struct { + register + X Value +} + +// The Convert instruction yields the conversion of value X to type +// Type(). One or both of those types is basic (but possibly named). +// +// A conversion may change the value and representation of its operand. +// Conversions are permitted: +// - between real numeric types. +// - between complex numeric types. +// - between string and []byte or []rune. +// - between pointers and unsafe.Pointer. +// - between unsafe.Pointer and uintptr. +// - from (Unicode) integer to (UTF-8) string. +// A conversion may imply a type name change also. +// +// This operation cannot fail dynamically. +// +// Conversions of untyped string/number/bool constants to a specific +// representation are eliminated during SSA construction. +// +// Pos() returns the ast.CallExpr.Lparen, if the instruction arose +// from an explicit conversion in the source. +// +// Example printed form: +// t1 = convert []byte <- string (t0) +// +type Convert struct { + register + X Value +} + +// ChangeInterface constructs a value of one interface type from a +// value of another interface type known to be assignable to it. +// This operation cannot fail. +// +// Pos() returns the ast.CallExpr.Lparen if the instruction arose from +// an explicit T(e) conversion; the ast.TypeAssertExpr.Lparen if the +// instruction arose from an explicit e.(T) operation; or token.NoPos +// otherwise. +// +// Example printed form: +// t1 = change interface interface{} <- I (t0) +// +type ChangeInterface struct { + register + X Value +} + +// MakeInterface constructs an instance of an interface type from a +// value of a concrete type. +// +// Use Program.MethodSets.MethodSet(X.Type()) to find the method-set +// of X, and Program.Method(m) to find the implementation of a method. +// +// To construct the zero value of an interface type T, use: +// NewConst(exact.MakeNil(), T, pos) +// +// Pos() returns the ast.CallExpr.Lparen, if the instruction arose +// from an explicit conversion in the source. +// +// Example printed form: +// t1 = make interface{} <- int (42:int) +// t2 = make Stringer <- t0 +// +type MakeInterface struct { + register + X Value +} + +// The MakeClosure instruction yields a closure value whose code is +// Fn and whose free variables' values are supplied by Bindings. +// +// Type() returns a (possibly named) *types.Signature. +// +// Pos() returns the ast.FuncLit.Type.Func for a function literal +// closure or the ast.SelectorExpr.Sel for a bound method closure. +// +// Example printed form: +// t0 = make closure anon@1.2 [x y z] +// t1 = make closure bound$(main.I).add [i] +// +type MakeClosure struct { + register + Fn Value // always a *Function + Bindings []Value // values for each free variable in Fn.FreeVars +} + +// The MakeMap instruction creates a new hash-table-based map object +// and yields a value of kind map. +// +// Type() returns a (possibly named) *types.Map. +// +// Pos() returns the ast.CallExpr.Lparen, if created by make(map), or +// the ast.CompositeLit.Lbrack if created by a literal. +// +// Example printed form: +// t1 = make map[string]int t0 +// t1 = make StringIntMap t0 +// +type MakeMap struct { + register + Reserve Value // initial space reservation; nil => default +} + +// The MakeChan instruction creates a new channel object and yields a +// value of kind chan. +// +// Type() returns a (possibly named) *types.Chan. +// +// Pos() returns the ast.CallExpr.Lparen for the make(chan) that +// created it. +// +// Example printed form: +// t0 = make chan int 0 +// t0 = make IntChan 0 +// +type MakeChan struct { + register + Size Value // int; size of buffer; zero => synchronous. +} + +// The MakeSlice instruction yields a slice of length Len backed by a +// newly allocated array of length Cap. +// +// Both Len and Cap must be non-nil Values of integer type. +// +// (Alloc(types.Array) followed by Slice will not suffice because +// Alloc can only create arrays of constant length.) +// +// Type() returns a (possibly named) *types.Slice. +// +// Pos() returns the ast.CallExpr.Lparen for the make([]T) that +// created it. +// +// Example printed form: +// t1 = make []string 1:int t0 +// t1 = make StringSlice 1:int t0 +// +type MakeSlice struct { + register + Len Value + Cap Value +} + +// The Slice instruction yields a slice of an existing string, slice +// or *array X between optional integer bounds Low and High. +// +// Dynamically, this instruction panics if X evaluates to a nil *array +// pointer. +// +// Type() returns string if the type of X was string, otherwise a +// *types.Slice with the same element type as X. +// +// Pos() returns the ast.SliceExpr.Lbrack if created by a x[:] slice +// operation, the ast.CompositeLit.Lbrace if created by a literal, or +// NoPos if not explicit in the source (e.g. a variadic argument slice). +// +// Example printed form: +// t1 = slice t0[1:] +// +type Slice struct { + register + X Value // slice, string, or *array + Low, High, Max Value // each may be nil +} + +// The FieldAddr instruction yields the address of Field of *struct X. +// +// The field is identified by its index within the field list of the +// struct type of X. +// +// Dynamically, this instruction panics if X evaluates to a nil +// pointer. +// +// Type() returns a (possibly named) *types.Pointer. +// +// Pos() returns the position of the ast.SelectorExpr.Sel for the +// field, if explicit in the source. +// +// Example printed form: +// t1 = &t0.name [#1] +// +type FieldAddr struct { + register + X Value // *struct + Field int // index into X.Type().Deref().(*types.Struct).Fields +} + +// The Field instruction yields the Field of struct X. +// +// The field is identified by its index within the field list of the +// struct type of X; by using numeric indices we avoid ambiguity of +// package-local identifiers and permit compact representations. +// +// Pos() returns the position of the ast.SelectorExpr.Sel for the +// field, if explicit in the source. +// +// Example printed form: +// t1 = t0.name [#1] +// +type Field struct { + register + X Value // struct + Field int // index into X.Type().(*types.Struct).Fields +} + +// The IndexAddr instruction yields the address of the element at +// index Index of collection X. Index is an integer expression. +// +// The elements of maps and strings are not addressable; use Lookup or +// MapUpdate instead. +// +// Dynamically, this instruction panics if X evaluates to a nil *array +// pointer. +// +// Type() returns a (possibly named) *types.Pointer. +// +// Pos() returns the ast.IndexExpr.Lbrack for the index operation, if +// explicit in the source. +// +// Example printed form: +// t2 = &t0[t1] +// +type IndexAddr struct { + register + X Value // slice or *array, + Index Value // numeric index +} + +// The Index instruction yields element Index of array X. +// +// Pos() returns the ast.IndexExpr.Lbrack for the index operation, if +// explicit in the source. +// +// Example printed form: +// t2 = t0[t1] +// +type Index struct { + register + X Value // array + Index Value // integer index +} + +// The Lookup instruction yields element Index of collection X, a map +// or string. Index is an integer expression if X is a string or the +// appropriate key type if X is a map. +// +// If CommaOk, the result is a 2-tuple of the value above and a +// boolean indicating the result of a map membership test for the key. +// The components of the tuple are accessed using Extract. +// +// Pos() returns the ast.IndexExpr.Lbrack, if explicit in the source. +// +// Example printed form: +// t2 = t0[t1] +// t5 = t3[t4],ok +// +type Lookup struct { + register + X Value // string or map + Index Value // numeric or key-typed index + CommaOk bool // return a value,ok pair +} + +// SelectState is a helper for Select. +// It represents one goal state and its corresponding communication. +// +type SelectState struct { + Dir types.ChanDir // direction of case (SendOnly or RecvOnly) + Chan Value // channel to use (for send or receive) + Send Value // value to send (for send) + Pos token.Pos // position of token.ARROW + DebugNode ast.Node // ast.SendStmt or ast.UnaryExpr(<-) [debug mode] +} + +// The Select instruction tests whether (or blocks until) one +// of the specified sent or received states is entered. +// +// Let n be the number of States for which Dir==RECV and T_i (0<=i<n) +// be the element type of each such state's Chan. +// Select returns an n+2-tuple +// (index int, recvOk bool, r_0 T_0, ... r_n-1 T_n-1) +// The tuple's components, described below, must be accessed via the +// Extract instruction. +// +// If Blocking, select waits until exactly one state holds, i.e. a +// channel becomes ready for the designated operation of sending or +// receiving; select chooses one among the ready states +// pseudorandomly, performs the send or receive operation, and sets +// 'index' to the index of the chosen channel. +// +// If !Blocking, select doesn't block if no states hold; instead it +// returns immediately with index equal to -1. +// +// If the chosen channel was used for a receive, the r_i component is +// set to the received value, where i is the index of that state among +// all n receive states; otherwise r_i has the zero value of type T_i. +// Note that the receive index i is not the same as the state +// index index. +// +// The second component of the triple, recvOk, is a boolean whose value +// is true iff the selected operation was a receive and the receive +// successfully yielded a value. +// +// Pos() returns the ast.SelectStmt.Select. +// +// Example printed form: +// t3 = select nonblocking [<-t0, t1<-t2] +// t4 = select blocking [] +// +type Select struct { + register + States []*SelectState + Blocking bool +} + +// The Range instruction yields an iterator over the domain and range +// of X, which must be a string or map. +// +// Elements are accessed via Next. +// +// Type() returns an opaque and degenerate "rangeIter" type. +// +// Pos() returns the ast.RangeStmt.For. +// +// Example printed form: +// t0 = range "hello":string +// +type Range struct { + register + X Value // string or map +} + +// The Next instruction reads and advances the (map or string) +// iterator Iter and returns a 3-tuple value (ok, k, v). If the +// iterator is not exhausted, ok is true and k and v are the next +// elements of the domain and range, respectively. Otherwise ok is +// false and k and v are undefined. +// +// Components of the tuple are accessed using Extract. +// +// The IsString field distinguishes iterators over strings from those +// over maps, as the Type() alone is insufficient: consider +// map[int]rune. +// +// Type() returns a *types.Tuple for the triple (ok, k, v). +// The types of k and/or v may be types.Invalid. +// +// Example printed form: +// t1 = next t0 +// +type Next struct { + register + Iter Value + IsString bool // true => string iterator; false => map iterator. +} + +// The TypeAssert instruction tests whether interface value X has type +// AssertedType. +// +// If !CommaOk, on success it returns v, the result of the conversion +// (defined below); on failure it panics. +// +// If CommaOk: on success it returns a pair (v, true) where v is the +// result of the conversion; on failure it returns (z, false) where z +// is AssertedType's zero value. The components of the pair must be +// accessed using the Extract instruction. +// +// If AssertedType is a concrete type, TypeAssert checks whether the +// dynamic type in interface X is equal to it, and if so, the result +// of the conversion is a copy of the value in the interface. +// +// If AssertedType is an interface, TypeAssert checks whether the +// dynamic type of the interface is assignable to it, and if so, the +// result of the conversion is a copy of the interface value X. +// If AssertedType is a superinterface of X.Type(), the operation will +// fail iff the operand is nil. (Contrast with ChangeInterface, which +// performs no nil-check.) +// +// Type() reflects the actual type of the result, possibly a +// 2-types.Tuple; AssertedType is the asserted type. +// +// Pos() returns the ast.CallExpr.Lparen if the instruction arose from +// an explicit T(e) conversion; the ast.TypeAssertExpr.Lparen if the +// instruction arose from an explicit e.(T) operation; or the +// ast.CaseClause.Case if the instruction arose from a case of a +// type-switch statement. +// +// Example printed form: +// t1 = typeassert t0.(int) +// t3 = typeassert,ok t2.(T) +// +type TypeAssert struct { + register + X Value + AssertedType types.Type + CommaOk bool +} + +// The Extract instruction yields component Index of Tuple. +// +// This is used to access the results of instructions with multiple +// return values, such as Call, TypeAssert, Next, UnOp(ARROW) and +// IndexExpr(Map). +// +// Example printed form: +// t1 = extract t0 #1 +// +type Extract struct { + register + Tuple Value + Index int +} + +// Instructions executed for effect. They do not yield a value. -------------------- + +// The Jump instruction transfers control to the sole successor of its +// owning block. +// +// A Jump must be the last instruction of its containing BasicBlock. +// +// Pos() returns NoPos. +// +// Example printed form: +// jump done +// +type Jump struct { + anInstruction +} + +// The If instruction transfers control to one of the two successors +// of its owning block, depending on the boolean Cond: the first if +// true, the second if false. +// +// An If instruction must be the last instruction of its containing +// BasicBlock. +// +// Pos() returns NoPos. +// +// Example printed form: +// if t0 goto done else body +// +type If struct { + anInstruction + Cond Value +} + +// The Return instruction returns values and control back to the calling +// function. +// +// len(Results) is always equal to the number of results in the +// function's signature. +// +// If len(Results) > 1, Return returns a tuple value with the specified +// components which the caller must access using Extract instructions. +// +// There is no instruction to return a ready-made tuple like those +// returned by a "value,ok"-mode TypeAssert, Lookup or UnOp(ARROW) or +// a tail-call to a function with multiple result parameters. +// +// Return must be the last instruction of its containing BasicBlock. +// Such a block has no successors. +// +// Pos() returns the ast.ReturnStmt.Return, if explicit in the source. +// +// Example printed form: +// return +// return nil:I, 2:int +// +type Return struct { + anInstruction + Results []Value + pos token.Pos +} + +// The RunDefers instruction pops and invokes the entire stack of +// procedure calls pushed by Defer instructions in this function. +// +// It is legal to encounter multiple 'rundefers' instructions in a +// single control-flow path through a function; this is useful in +// the combined init() function, for example. +// +// Pos() returns NoPos. +// +// Example printed form: +// rundefers +// +type RunDefers struct { + anInstruction +} + +// The Panic instruction initiates a panic with value X. +// +// A Panic instruction must be the last instruction of its containing +// BasicBlock, which must have no successors. +// +// NB: 'go panic(x)' and 'defer panic(x)' do not use this instruction; +// they are treated as calls to a built-in function. +// +// Pos() returns the ast.CallExpr.Lparen if this panic was explicit +// in the source. +// +// Example printed form: +// panic t0 +// +type Panic struct { + anInstruction + X Value // an interface{} + pos token.Pos +} + +// The Go instruction creates a new goroutine and calls the specified +// function within it. +// +// See CallCommon for generic function call documentation. +// +// Pos() returns the ast.GoStmt.Go. +// +// Example printed form: +// go println(t0, t1) +// go t3() +// go invoke t5.Println(...t6) +// +type Go struct { + anInstruction + Call CallCommon + pos token.Pos +} + +// The Defer instruction pushes the specified call onto a stack of +// functions to be called by a RunDefers instruction or by a panic. +// +// See CallCommon for generic function call documentation. +// +// Pos() returns the ast.DeferStmt.Defer. +// +// Example printed form: +// defer println(t0, t1) +// defer t3() +// defer invoke t5.Println(...t6) +// +type Defer struct { + anInstruction + Call CallCommon + pos token.Pos +} + +// The Send instruction sends X on channel Chan. +// +// Pos() returns the ast.SendStmt.Arrow, if explicit in the source. +// +// Example printed form: +// send t0 <- t1 +// +type Send struct { + anInstruction + Chan, X Value + pos token.Pos +} + +// The Store instruction stores Val at address Addr. +// Stores can be of arbitrary types. +// +// Pos() returns the position of the source-level construct most closely +// associated with the memory store operation. +// Since implicit memory stores are numerous and varied and depend upon +// implementation choices, the details are not specified. +// +// Example printed form: +// *x = y +// +type Store struct { + anInstruction + Addr Value + Val Value + pos token.Pos +} + +// The MapUpdate instruction updates the association of Map[Key] to +// Value. +// +// Pos() returns the ast.KeyValueExpr.Colon or ast.IndexExpr.Lbrack, +// if explicit in the source. +// +// Example printed form: +// t0[t1] = t2 +// +type MapUpdate struct { + anInstruction + Map Value + Key Value + Value Value + pos token.Pos +} + +// A DebugRef instruction maps a source-level expression Expr to the +// SSA value X that represents the value (!IsAddr) or address (IsAddr) +// of that expression. +// +// DebugRef is a pseudo-instruction: it has no dynamic effect. +// +// Pos() returns Expr.Pos(), the start position of the source-level +// expression. This is not the same as the "designated" token as +// documented at Value.Pos(). e.g. CallExpr.Pos() does not return the +// position of the ("designated") Lparen token. +// +// If Expr is an *ast.Ident denoting a var or func, Object() returns +// the object; though this information can be obtained from the type +// checker, including it here greatly facilitates debugging. +// For non-Ident expressions, Object() returns nil. +// +// DebugRefs are generated only for functions built with debugging +// enabled; see Package.SetDebugMode() and the GlobalDebug builder +// mode flag. +// +// DebugRefs are not emitted for ast.Idents referring to constants or +// predeclared identifiers, since they are trivial and numerous. +// Nor are they emitted for ast.ParenExprs. +// +// (By representing these as instructions, rather than out-of-band, +// consistency is maintained during transformation passes by the +// ordinary SSA renaming machinery.) +// +// Example printed form: +// ; *ast.CallExpr @ 102:9 is t5 +// ; var x float64 @ 109:72 is x +// ; address of *ast.CompositeLit @ 216:10 is t0 +// +type DebugRef struct { + anInstruction + Expr ast.Expr // the referring expression (never *ast.ParenExpr) + object types.Object // the identity of the source var/func + IsAddr bool // Expr is addressable and X is the address it denotes + X Value // the value or address of Expr +} + +// Embeddable mix-ins and helpers for common parts of other structs. ----------- + +// register is a mix-in embedded by all SSA values that are also +// instructions, i.e. virtual registers, and provides a uniform +// implementation of most of the Value interface: Value.Name() is a +// numbered register (e.g. "t0"); the other methods are field accessors. +// +// Temporary names are automatically assigned to each register on +// completion of building a function in SSA form. +// +// Clients must not assume that the 'id' value (and the Name() derived +// from it) is unique within a function. As always in this API, +// semantics are determined only by identity; names exist only to +// facilitate debugging. +// +type register struct { + anInstruction + num int // "name" of virtual register, e.g. "t0". Not guaranteed unique. + typ types.Type // type of virtual register + pos token.Pos // position of source expression, or NoPos + referrers []Instruction +} + +// anInstruction is a mix-in embedded by all Instructions. +// It provides the implementations of the Block and setBlock methods. +type anInstruction struct { + block *BasicBlock // the basic block of this instruction +} + +// CallCommon is contained by Go, Defer and Call to hold the +// common parts of a function or method call. +// +// Each CallCommon exists in one of two modes, function call and +// interface method invocation, or "call" and "invoke" for short. +// +// 1. "call" mode: when Method is nil (!IsInvoke), a CallCommon +// represents an ordinary function call of the value in Value, +// which may be a *Builtin, a *Function or any other value of kind +// 'func'. +// +// Value may be one of: +// (a) a *Function, indicating a statically dispatched call +// to a package-level function, an anonymous function, or +// a method of a named type. +// (b) a *MakeClosure, indicating an immediately applied +// function literal with free variables. +// (c) a *Builtin, indicating a statically dispatched call +// to a built-in function. +// (d) any other value, indicating a dynamically dispatched +// function call. +// StaticCallee returns the identity of the callee in cases +// (a) and (b), nil otherwise. +// +// Args contains the arguments to the call. If Value is a method, +// Args[0] contains the receiver parameter. +// +// Example printed form: +// t2 = println(t0, t1) +// go t3() +// defer t5(...t6) +// +// 2. "invoke" mode: when Method is non-nil (IsInvoke), a CallCommon +// represents a dynamically dispatched call to an interface method. +// In this mode, Value is the interface value and Method is the +// interface's abstract method. Note: an abstract method may be +// shared by multiple interfaces due to embedding; Value.Type() +// provides the specific interface used for this call. +// +// Value is implicitly supplied to the concrete method implementation +// as the receiver parameter; in other words, Args[0] holds not the +// receiver but the first true argument. +// +// Example printed form: +// t1 = invoke t0.String() +// go invoke t3.Run(t2) +// defer invoke t4.Handle(...t5) +// +// For all calls to variadic functions (Signature().Variadic()), +// the last element of Args is a slice. +// +type CallCommon struct { + Value Value // receiver (invoke mode) or func value (call mode) + Method *types.Func // abstract method (invoke mode) + Args []Value // actual parameters (in static method call, includes receiver) + pos token.Pos // position of CallExpr.Lparen, iff explicit in source +} + +// IsInvoke returns true if this call has "invoke" (not "call") mode. +func (c *CallCommon) IsInvoke() bool { + return c.Method != nil +} + +func (c *CallCommon) Pos() token.Pos { return c.pos } + +// Signature returns the signature of the called function. +// +// For an "invoke"-mode call, the signature of the interface method is +// returned. +// +// In either "call" or "invoke" mode, if the callee is a method, its +// receiver is represented by sig.Recv, not sig.Params().At(0). +// +func (c *CallCommon) Signature() *types.Signature { + if c.Method != nil { + return c.Method.Type().(*types.Signature) + } + return c.Value.Type().Underlying().(*types.Signature) +} + +// StaticCallee returns the callee if this is a trivially static +// "call"-mode call to a function. +func (c *CallCommon) StaticCallee() *Function { + switch fn := c.Value.(type) { + case *Function: + return fn + case *MakeClosure: + return fn.Fn.(*Function) + } + return nil +} + +// Description returns a description of the mode of this call suitable +// for a user interface, e.g., "static method call". +func (c *CallCommon) Description() string { + switch fn := c.Value.(type) { + case *Builtin: + return "built-in function call" + case *MakeClosure: + return "static function closure call" + case *Function: + if fn.Signature.Recv() != nil { + return "static method call" + } + return "static function call" + } + if c.IsInvoke() { + return "dynamic method call" // ("invoke" mode) + } + return "dynamic function call" +} + +// The CallInstruction interface, implemented by *Go, *Defer and *Call, +// exposes the common parts of function-calling instructions, +// yet provides a way back to the Value defined by *Call alone. +// +type CallInstruction interface { + Instruction + Common() *CallCommon // returns the common parts of the call + Value() *Call // returns the result value of the call (*Call) or nil (*Go, *Defer) +} + +func (s *Call) Common() *CallCommon { return &s.Call } +func (s *Defer) Common() *CallCommon { return &s.Call } +func (s *Go) Common() *CallCommon { return &s.Call } + +func (s *Call) Value() *Call { return s } +func (s *Defer) Value() *Call { return nil } +func (s *Go) Value() *Call { return nil } + +func (v *Builtin) Type() types.Type { return v.sig } +func (v *Builtin) Name() string { return v.name } +func (*Builtin) Referrers() *[]Instruction { return nil } +func (v *Builtin) Pos() token.Pos { return token.NoPos } +func (v *Builtin) Object() types.Object { return types.Universe.Lookup(v.name) } +func (v *Builtin) Parent() *Function { return nil } + +func (v *FreeVar) Type() types.Type { return v.typ } +func (v *FreeVar) Name() string { return v.name } +func (v *FreeVar) Referrers() *[]Instruction { return &v.referrers } +func (v *FreeVar) Pos() token.Pos { return v.pos } +func (v *FreeVar) Parent() *Function { return v.parent } + +func (v *Global) Type() types.Type { return v.typ } +func (v *Global) Name() string { return v.name } +func (v *Global) Parent() *Function { return nil } +func (v *Global) Pos() token.Pos { return v.pos } +func (v *Global) Referrers() *[]Instruction { return nil } +func (v *Global) Token() token.Token { return token.VAR } +func (v *Global) Object() types.Object { return v.object } +func (v *Global) String() string { return v.RelString(nil) } +func (v *Global) Package() *Package { return v.Pkg } +func (v *Global) RelString(from *types.Package) string { return relString(v, from) } + +func (v *Function) Name() string { return v.name } +func (v *Function) Type() types.Type { return v.Signature } +func (v *Function) Pos() token.Pos { return v.pos } +func (v *Function) Token() token.Token { return token.FUNC } +func (v *Function) Object() types.Object { return v.object } +func (v *Function) String() string { return v.RelString(nil) } +func (v *Function) Package() *Package { return v.Pkg } +func (v *Function) Parent() *Function { return v.parent } +func (v *Function) Referrers() *[]Instruction { + if v.parent != nil { + return &v.referrers + } + return nil +} + +func (v *Parameter) Type() types.Type { return v.typ } +func (v *Parameter) Name() string { return v.name } +func (v *Parameter) Object() types.Object { return v.object } +func (v *Parameter) Referrers() *[]Instruction { return &v.referrers } +func (v *Parameter) Pos() token.Pos { return v.pos } +func (v *Parameter) Parent() *Function { return v.parent } + +func (v *Alloc) Type() types.Type { return v.typ } +func (v *Alloc) Referrers() *[]Instruction { return &v.referrers } +func (v *Alloc) Pos() token.Pos { return v.pos } + +func (v *register) Type() types.Type { return v.typ } +func (v *register) setType(typ types.Type) { v.typ = typ } +func (v *register) Name() string { return fmt.Sprintf("t%d", v.num) } +func (v *register) setNum(num int) { v.num = num } +func (v *register) Referrers() *[]Instruction { return &v.referrers } +func (v *register) Pos() token.Pos { return v.pos } +func (v *register) setPos(pos token.Pos) { v.pos = pos } + +func (v *anInstruction) Parent() *Function { return v.block.parent } +func (v *anInstruction) Block() *BasicBlock { return v.block } +func (v *anInstruction) setBlock(block *BasicBlock) { v.block = block } +func (v *anInstruction) Referrers() *[]Instruction { return nil } + +func (t *Type) Name() string { return t.object.Name() } +func (t *Type) Pos() token.Pos { return t.object.Pos() } +func (t *Type) Type() types.Type { return t.object.Type() } +func (t *Type) Token() token.Token { return token.TYPE } +func (t *Type) Object() types.Object { return t.object } +func (t *Type) String() string { return t.RelString(nil) } +func (t *Type) Package() *Package { return t.pkg } +func (t *Type) RelString(from *types.Package) string { return relString(t, from) } + +func (c *NamedConst) Name() string { return c.object.Name() } +func (c *NamedConst) Pos() token.Pos { return c.object.Pos() } +func (c *NamedConst) String() string { return c.RelString(nil) } +func (c *NamedConst) Type() types.Type { return c.object.Type() } +func (c *NamedConst) Token() token.Token { return token.CONST } +func (c *NamedConst) Object() types.Object { return c.object } +func (c *NamedConst) Package() *Package { return c.pkg } +func (c *NamedConst) RelString(from *types.Package) string { return relString(c, from) } + +// Func returns the package-level function of the specified name, +// or nil if not found. +// +func (p *Package) Func(name string) (f *Function) { + f, _ = p.Members[name].(*Function) + return +} + +// Var returns the package-level variable of the specified name, +// or nil if not found. +// +func (p *Package) Var(name string) (g *Global) { + g, _ = p.Members[name].(*Global) + return +} + +// Const returns the package-level constant of the specified name, +// or nil if not found. +// +func (p *Package) Const(name string) (c *NamedConst) { + c, _ = p.Members[name].(*NamedConst) + return +} + +// Type returns the package-level type of the specified name, +// or nil if not found. +// +func (p *Package) Type(name string) (t *Type) { + t, _ = p.Members[name].(*Type) + return +} + +func (v *Call) Pos() token.Pos { return v.Call.pos } +func (s *Defer) Pos() token.Pos { return s.pos } +func (s *Go) Pos() token.Pos { return s.pos } +func (s *MapUpdate) Pos() token.Pos { return s.pos } +func (s *Panic) Pos() token.Pos { return s.pos } +func (s *Return) Pos() token.Pos { return s.pos } +func (s *Send) Pos() token.Pos { return s.pos } +func (s *Store) Pos() token.Pos { return s.pos } +func (s *If) Pos() token.Pos { return token.NoPos } +func (s *Jump) Pos() token.Pos { return token.NoPos } +func (s *RunDefers) Pos() token.Pos { return token.NoPos } +func (s *DebugRef) Pos() token.Pos { return s.Expr.Pos() } + +// Operands. + +func (v *Alloc) Operands(rands []*Value) []*Value { + return rands +} + +func (v *BinOp) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Y) +} + +func (c *CallCommon) Operands(rands []*Value) []*Value { + rands = append(rands, &c.Value) + for i := range c.Args { + rands = append(rands, &c.Args[i]) + } + return rands +} + +func (s *Go) Operands(rands []*Value) []*Value { + return s.Call.Operands(rands) +} + +func (s *Call) Operands(rands []*Value) []*Value { + return s.Call.Operands(rands) +} + +func (s *Defer) Operands(rands []*Value) []*Value { + return s.Call.Operands(rands) +} + +func (v *ChangeInterface) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *ChangeType) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *Convert) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (s *DebugRef) Operands(rands []*Value) []*Value { + return append(rands, &s.X) +} + +func (v *Extract) Operands(rands []*Value) []*Value { + return append(rands, &v.Tuple) +} + +func (v *Field) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *FieldAddr) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (s *If) Operands(rands []*Value) []*Value { + return append(rands, &s.Cond) +} + +func (v *Index) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Index) +} + +func (v *IndexAddr) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Index) +} + +func (*Jump) Operands(rands []*Value) []*Value { + return rands +} + +func (v *Lookup) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Index) +} + +func (v *MakeChan) Operands(rands []*Value) []*Value { + return append(rands, &v.Size) +} + +func (v *MakeClosure) Operands(rands []*Value) []*Value { + rands = append(rands, &v.Fn) + for i := range v.Bindings { + rands = append(rands, &v.Bindings[i]) + } + return rands +} + +func (v *MakeInterface) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *MakeMap) Operands(rands []*Value) []*Value { + return append(rands, &v.Reserve) +} + +func (v *MakeSlice) Operands(rands []*Value) []*Value { + return append(rands, &v.Len, &v.Cap) +} + +func (v *MapUpdate) Operands(rands []*Value) []*Value { + return append(rands, &v.Map, &v.Key, &v.Value) +} + +func (v *Next) Operands(rands []*Value) []*Value { + return append(rands, &v.Iter) +} + +func (s *Panic) Operands(rands []*Value) []*Value { + return append(rands, &s.X) +} + +func (v *Phi) Operands(rands []*Value) []*Value { + for i := range v.Edges { + rands = append(rands, &v.Edges[i]) + } + return rands +} + +func (v *Range) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (s *Return) Operands(rands []*Value) []*Value { + for i := range s.Results { + rands = append(rands, &s.Results[i]) + } + return rands +} + +func (*RunDefers) Operands(rands []*Value) []*Value { + return rands +} + +func (v *Select) Operands(rands []*Value) []*Value { + for i := range v.States { + rands = append(rands, &v.States[i].Chan, &v.States[i].Send) + } + return rands +} + +func (s *Send) Operands(rands []*Value) []*Value { + return append(rands, &s.Chan, &s.X) +} + +func (v *Slice) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Low, &v.High, &v.Max) +} + +func (s *Store) Operands(rands []*Value) []*Value { + return append(rands, &s.Addr, &s.Val) +} + +func (v *TypeAssert) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *UnOp) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +// Non-Instruction Values: +func (v *Builtin) Operands(rands []*Value) []*Value { return rands } +func (v *FreeVar) Operands(rands []*Value) []*Value { return rands } +func (v *Const) Operands(rands []*Value) []*Value { return rands } +func (v *Function) Operands(rands []*Value) []*Value { return rands } +func (v *Global) Operands(rands []*Value) []*Value { return rands } +func (v *Parameter) Operands(rands []*Value) []*Value { return rands } diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/load.go b/vendor/golang.org/x/tools/go/ssa/ssautil/load.go new file mode 100644 index 0000000..30b8053 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/load.go @@ -0,0 +1,95 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil + +// This file defines utility functions for constructing programs in SSA form. + +import ( + "go/ast" + "go/token" + "go/types" + + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" +) + +// CreateProgram returns a new program in SSA form, given a program +// loaded from source. An SSA package is created for each transitively +// error-free package of lprog. +// +// Code for bodies of functions is not built until Build is called +// on the result. +// +// mode controls diagnostics and checking during SSA construction. +// +func CreateProgram(lprog *loader.Program, mode ssa.BuilderMode) *ssa.Program { + prog := ssa.NewProgram(lprog.Fset, mode) + + for _, info := range lprog.AllPackages { + if info.TransitivelyErrorFree { + prog.CreatePackage(info.Pkg, info.Files, &info.Info, info.Importable) + } + } + + return prog +} + +// BuildPackage builds an SSA program with IR for a single package. +// +// It populates pkg by type-checking the specified file ASTs. All +// dependencies are loaded using the importer specified by tc, which +// typically loads compiler export data; SSA code cannot be built for +// those packages. BuildPackage then constructs an ssa.Program with all +// dependency packages created, and builds and returns the SSA package +// corresponding to pkg. +// +// The caller must have set pkg.Path() to the import path. +// +// The operation fails if there were any type-checking or import errors. +// +// See ../ssa/example_test.go for an example. +// +func BuildPackage(tc *types.Config, fset *token.FileSet, pkg *types.Package, files []*ast.File, mode ssa.BuilderMode) (*ssa.Package, *types.Info, error) { + if fset == nil { + panic("no token.FileSet") + } + if pkg.Path() == "" { + panic("package has no import path") + } + + info := &types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + } + if err := types.NewChecker(tc, fset, pkg, info).Files(files); err != nil { + return nil, nil, err + } + + prog := ssa.NewProgram(fset, mode) + + // Create SSA packages for all imports. + // Order is not significant. + created := make(map[*types.Package]bool) + var createAll func(pkgs []*types.Package) + createAll = func(pkgs []*types.Package) { + for _, p := range pkgs { + if !created[p] { + created[p] = true + prog.CreatePackage(p, nil, nil, true) + createAll(p.Imports()) + } + } + } + createAll(pkg.Imports()) + + // Create and build the primary package. + ssapkg := prog.CreatePackage(pkg, files, info, false) + ssapkg.Build() + return ssapkg, info, nil +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/load_test.go b/vendor/golang.org/x/tools/go/ssa/ssautil/load_test.go new file mode 100644 index 0000000..8ccd463 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/load_test.go @@ -0,0 +1,64 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil_test + +import ( + "go/ast" + "go/importer" + "go/parser" + "go/token" + "go/types" + "os" + "testing" + + "golang.org/x/tools/go/ssa/ssautil" +) + +const hello = `package main + +import "fmt" + +func main() { + fmt.Println("Hello, world") +} +` + +func TestBuildPackage(t *testing.T) { + // There is a more substantial test of BuildPackage and the + // SSA program it builds in ../ssa/builder_test.go. + + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "hello.go", hello, 0) + if err != nil { + t.Fatal(err) + } + + pkg := types.NewPackage("hello", "") + ssapkg, _, err := ssautil.BuildPackage(&types.Config{Importer: importer.Default()}, fset, pkg, []*ast.File{f}, 0) + if err != nil { + t.Fatal(err) + } + if pkg.Name() != "main" { + t.Errorf("pkg.Name() = %s, want main", pkg.Name()) + } + if ssapkg.Func("main") == nil { + ssapkg.WriteTo(os.Stderr) + t.Errorf("ssapkg has no main function") + } +} + +func TestBuildPackage_MissingImport(t *testing.T) { + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "bad.go", `package bad; import "missing"`, 0) + if err != nil { + t.Fatal(err) + } + + pkg := types.NewPackage("bad", "") + ssapkg, _, err := ssautil.BuildPackage(new(types.Config), fset, pkg, []*ast.File{f}, 0) + if err == nil || ssapkg != nil { + t.Fatal("BuildPackage succeeded unexpectedly") + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/switch.go b/vendor/golang.org/x/tools/go/ssa/ssautil/switch.go new file mode 100644 index 0000000..db03bf5 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/switch.go @@ -0,0 +1,234 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil + +// This file implements discovery of switch and type-switch constructs +// from low-level control flow. +// +// Many techniques exist for compiling a high-level switch with +// constant cases to efficient machine code. The optimal choice will +// depend on the data type, the specific case values, the code in the +// body of each case, and the hardware. +// Some examples: +// - a lookup table (for a switch that maps constants to constants) +// - a computed goto +// - a binary tree +// - a perfect hash +// - a two-level switch (to partition constant strings by their first byte). + +import ( + "bytes" + "fmt" + "go/token" + "go/types" + + "golang.org/x/tools/go/ssa" +) + +// A ConstCase represents a single constant comparison. +// It is part of a Switch. +type ConstCase struct { + Block *ssa.BasicBlock // block performing the comparison + Body *ssa.BasicBlock // body of the case + Value *ssa.Const // case comparand +} + +// A TypeCase represents a single type assertion. +// It is part of a Switch. +type TypeCase struct { + Block *ssa.BasicBlock // block performing the type assert + Body *ssa.BasicBlock // body of the case + Type types.Type // case type + Binding ssa.Value // value bound by this case +} + +// A Switch is a logical high-level control flow operation +// (a multiway branch) discovered by analysis of a CFG containing +// only if/else chains. It is not part of the ssa.Instruction set. +// +// One of ConstCases and TypeCases has length >= 2; +// the other is nil. +// +// In a value switch, the list of cases may contain duplicate constants. +// A type switch may contain duplicate types, or types assignable +// to an interface type also in the list. +// TODO(adonovan): eliminate such duplicates. +// +type Switch struct { + Start *ssa.BasicBlock // block containing start of if/else chain + X ssa.Value // the switch operand + ConstCases []ConstCase // ordered list of constant comparisons + TypeCases []TypeCase // ordered list of type assertions + Default *ssa.BasicBlock // successor if all comparisons fail +} + +func (sw *Switch) String() string { + // We represent each block by the String() of its + // first Instruction, e.g. "print(42:int)". + var buf bytes.Buffer + if sw.ConstCases != nil { + fmt.Fprintf(&buf, "switch %s {\n", sw.X.Name()) + for _, c := range sw.ConstCases { + fmt.Fprintf(&buf, "case %s: %s\n", c.Value, c.Body.Instrs[0]) + } + } else { + fmt.Fprintf(&buf, "switch %s.(type) {\n", sw.X.Name()) + for _, c := range sw.TypeCases { + fmt.Fprintf(&buf, "case %s %s: %s\n", + c.Binding.Name(), c.Type, c.Body.Instrs[0]) + } + } + if sw.Default != nil { + fmt.Fprintf(&buf, "default: %s\n", sw.Default.Instrs[0]) + } + fmt.Fprintf(&buf, "}") + return buf.String() +} + +// Switches examines the control-flow graph of fn and returns the +// set of inferred value and type switches. A value switch tests an +// ssa.Value for equality against two or more compile-time constant +// values. Switches involving link-time constants (addresses) are +// ignored. A type switch type-asserts an ssa.Value against two or +// more types. +// +// The switches are returned in dominance order. +// +// The resulting switches do not necessarily correspond to uses of the +// 'switch' keyword in the source: for example, a single source-level +// switch statement with non-constant cases may result in zero, one or +// many Switches, one per plural sequence of constant cases. +// Switches may even be inferred from if/else- or goto-based control flow. +// (In general, the control flow constructs of the source program +// cannot be faithfully reproduced from the SSA representation.) +// +func Switches(fn *ssa.Function) []Switch { + // Traverse the CFG in dominance order, so we don't + // enter an if/else-chain in the middle. + var switches []Switch + seen := make(map[*ssa.BasicBlock]bool) // TODO(adonovan): opt: use ssa.blockSet + for _, b := range fn.DomPreorder() { + if x, k := isComparisonBlock(b); x != nil { + // Block b starts a switch. + sw := Switch{Start: b, X: x} + valueSwitch(&sw, k, seen) + if len(sw.ConstCases) > 1 { + switches = append(switches, sw) + } + } + + if y, x, T := isTypeAssertBlock(b); y != nil { + // Block b starts a type switch. + sw := Switch{Start: b, X: x} + typeSwitch(&sw, y, T, seen) + if len(sw.TypeCases) > 1 { + switches = append(switches, sw) + } + } + } + return switches +} + +func valueSwitch(sw *Switch, k *ssa.Const, seen map[*ssa.BasicBlock]bool) { + b := sw.Start + x := sw.X + for x == sw.X { + if seen[b] { + break + } + seen[b] = true + + sw.ConstCases = append(sw.ConstCases, ConstCase{ + Block: b, + Body: b.Succs[0], + Value: k, + }) + b = b.Succs[1] + if len(b.Instrs) > 2 { + // Block b contains not just 'if x == k', + // so it may have side effects that + // make it unsafe to elide. + break + } + if len(b.Preds) != 1 { + // Block b has multiple predecessors, + // so it cannot be treated as a case. + break + } + x, k = isComparisonBlock(b) + } + sw.Default = b +} + +func typeSwitch(sw *Switch, y ssa.Value, T types.Type, seen map[*ssa.BasicBlock]bool) { + b := sw.Start + x := sw.X + for x == sw.X { + if seen[b] { + break + } + seen[b] = true + + sw.TypeCases = append(sw.TypeCases, TypeCase{ + Block: b, + Body: b.Succs[0], + Type: T, + Binding: y, + }) + b = b.Succs[1] + if len(b.Instrs) > 4 { + // Block b contains not just + // {TypeAssert; Extract #0; Extract #1; If} + // so it may have side effects that + // make it unsafe to elide. + break + } + if len(b.Preds) != 1 { + // Block b has multiple predecessors, + // so it cannot be treated as a case. + break + } + y, x, T = isTypeAssertBlock(b) + } + sw.Default = b +} + +// isComparisonBlock returns the operands (v, k) if a block ends with +// a comparison v==k, where k is a compile-time constant. +// +func isComparisonBlock(b *ssa.BasicBlock) (v ssa.Value, k *ssa.Const) { + if n := len(b.Instrs); n >= 2 { + if i, ok := b.Instrs[n-1].(*ssa.If); ok { + if binop, ok := i.Cond.(*ssa.BinOp); ok && binop.Block() == b && binop.Op == token.EQL { + if k, ok := binop.Y.(*ssa.Const); ok { + return binop.X, k + } + if k, ok := binop.X.(*ssa.Const); ok { + return binop.Y, k + } + } + } + } + return +} + +// isTypeAssertBlock returns the operands (y, x, T) if a block ends with +// a type assertion "if y, ok := x.(T); ok {". +// +func isTypeAssertBlock(b *ssa.BasicBlock) (y, x ssa.Value, T types.Type) { + if n := len(b.Instrs); n >= 4 { + if i, ok := b.Instrs[n-1].(*ssa.If); ok { + if ext1, ok := i.Cond.(*ssa.Extract); ok && ext1.Block() == b && ext1.Index == 1 { + if ta, ok := ext1.Tuple.(*ssa.TypeAssert); ok && ta.Block() == b { + // hack: relies upon instruction ordering. + if ext0, ok := b.Instrs[n-3].(*ssa.Extract); ok { + return ext0, ta.X, ta.AssertedType + } + } + } + } + } + return +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/switch_test.go b/vendor/golang.org/x/tools/go/ssa/ssautil/switch_test.go new file mode 100644 index 0000000..a47dbef --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/switch_test.go @@ -0,0 +1,74 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// No testdata on Android. + +// +build !android + +package ssautil_test + +import ( + "go/parser" + "strings" + "testing" + + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +func TestSwitches(t *testing.T) { + conf := loader.Config{ParserMode: parser.ParseComments} + f, err := conf.ParseFile("testdata/switches.go", nil) + if err != nil { + t.Error(err) + return + } + + conf.CreateFromFiles("main", f) + iprog, err := conf.Load() + if err != nil { + t.Error(err) + return + } + + prog := ssautil.CreateProgram(iprog, 0) + mainPkg := prog.Package(iprog.Created[0].Pkg) + mainPkg.Build() + + for _, mem := range mainPkg.Members { + if fn, ok := mem.(*ssa.Function); ok { + if fn.Synthetic != "" { + continue // e.g. init() + } + // Each (multi-line) "switch" comment within + // this function must match the printed form + // of a ConstSwitch. + var wantSwitches []string + for _, c := range f.Comments { + if fn.Syntax().Pos() <= c.Pos() && c.Pos() < fn.Syntax().End() { + text := strings.TrimSpace(c.Text()) + if strings.HasPrefix(text, "switch ") { + wantSwitches = append(wantSwitches, text) + } + } + } + + switches := ssautil.Switches(fn) + if len(switches) != len(wantSwitches) { + t.Errorf("in %s, found %d switches, want %d", fn, len(switches), len(wantSwitches)) + } + for i, sw := range switches { + got := sw.String() + if i >= len(wantSwitches) { + continue + } + want := wantSwitches[i] + if got != want { + t.Errorf("in %s, found switch %d: got <<%s>>, want <<%s>>", fn, i, got, want) + } + } + } + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/testdata/switches.go b/vendor/golang.org/x/tools/go/ssa/ssautil/testdata/switches.go new file mode 100644 index 0000000..8ab4c11 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/testdata/switches.go @@ -0,0 +1,357 @@ +// +build ignore + +package main + +// This file is the input to TestSwitches in switch_test.go. +// Each multiway conditional with constant or type cases (Switch) +// discovered by Switches is printed, and compared with the +// comments. +// +// The body of each case is printed as the value of its first +// instruction. + +// -------- Value switches -------- + +func SimpleSwitch(x, y int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: print(23:int) + // case 3:int: print(23:int) + // case 4:int: print(3:int) + // default: x == y + // } + switch x { + case 1: + print(1) + case 2, 3: + print(23) + fallthrough + case 4: + print(3) + default: + print(4) + case y: + print(5) + } + print(6) +} + +func four() int { return 4 } + +// A non-constant case makes a switch "impure", but its pure +// cases form two separate switches. +func SwitchWithNonConstantCase(x int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: print(23:int) + // case 3:int: print(23:int) + // default: four() + // } + + // switch x { + // case 5:int: print(5:int) + // case 6:int: print(6:int) + // default: print("done":string) + // } + switch x { + case 1: + print(1) + case 2, 3: + print(23) + case four(): + print(3) + case 5: + print(5) + case 6: + print(6) + } + print("done") +} + +// Switches may be found even where the source +// program doesn't have a switch statement. + +func ImplicitSwitches(x, y int) { + // switch x { + // case 1:int: print(12:int) + // case 2:int: print(12:int) + // default: x < 5:int + // } + if x == 1 || 2 == x || x < 5 { + print(12) + } + + // switch x { + // case 3:int: print(34:int) + // case 4:int: print(34:int) + // default: x == y + // } + if x == 3 || 4 == x || x == y { + print(34) + } + + // Not a switch: no consistent variable. + if x == 5 || y == 6 { + print(56) + } + + // Not a switch: only one constant comparison. + if x == 7 || x == y { + print(78) + } +} + +func IfElseBasedSwitch(x int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: print(2:int) + // default: print("else":string) + // } + if x == 1 { + print(1) + } else if x == 2 { + print(2) + } else { + print("else") + } +} + +func GotoBasedSwitch(x int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: print(2:int) + // default: print("else":string) + // } + if x == 1 { + goto L1 + } + if x == 2 { + goto L2 + } + print("else") +L1: + print(1) + goto end +L2: + print(2) +end: +} + +func SwitchInAForLoop(x int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: print(2:int) + // default: print("head":string) + // } +loop: + for { + print("head") + switch x { + case 1: + print(1) + break loop + case 2: + print(2) + break loop + } + } +} + +// This case is a switch in a for-loop, both constructed using goto. +// As before, the default case points back to the block containing the +// switch, but that's ok. +func SwitchInAForLoopUsingGoto(x int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: print(2:int) + // default: print("head":string) + // } +loop: + print("head") + if x == 1 { + goto L1 + } + if x == 2 { + goto L2 + } + goto loop +L1: + print(1) + goto end +L2: + print(2) +end: +} + +func UnstructuredSwitchInAForLoop(x int) { + // switch x { + // case 1:int: print(1:int) + // case 2:int: x == 1:int + // default: print("end":string) + // } + for { + if x == 1 { + print(1) + return + } + if x == 2 { + continue + } + break + } + print("end") +} + +func CaseWithMultiplePreds(x int) { + for { + if x == 1 { + print(1) + return + } + loop: + // This block has multiple predecessors, + // so can't be treated as a switch case. + if x == 2 { + goto loop + } + break + } + print("end") +} + +func DuplicateConstantsAreNotEliminated(x int) { + // switch x { + // case 1:int: print(1:int) + // case 1:int: print("1a":string) + // case 2:int: print(2:int) + // default: return + // } + if x == 1 { + print(1) + } else if x == 1 { // duplicate => unreachable + print("1a") + } else if x == 2 { + print(2) + } +} + +// Interface values (created by comparisons) are not constants, +// so ConstSwitch.X is never of interface type. +func MakeInterfaceIsNotAConstant(x interface{}) { + if x == "foo" { + print("foo") + } else if x == 1 { + print(1) + } +} + +func ZeroInitializedVarsAreConstants(x int) { + // switch x { + // case 0:int: print(1:int) + // case 2:int: print(2:int) + // default: print("end":string) + // } + var zero int // SSA construction replaces zero with 0 + if x == zero { + print(1) + } else if x == 2 { + print(2) + } + print("end") +} + +// -------- Select -------- + +// NB, potentially fragile reliance on register number. +func SelectDesugarsToSwitch(ch chan int) { + // switch t1 { + // case 0:int: extract t0 #2 + // case 1:int: println(0:int) + // case 2:int: println(1:int) + // default: println("default":string) + // } + select { + case x := <-ch: + println(x) + case <-ch: + println(0) + case ch <- 1: + println(1) + default: + println("default") + } +} + +// NB, potentially fragile reliance on register number. +func NonblockingSelectDefaultCasePanics(ch chan int) { + // switch t1 { + // case 0:int: extract t0 #2 + // case 1:int: println(0:int) + // case 2:int: println(1:int) + // default: make interface{} <- string ("blocking select m...":string) + // } + select { + case x := <-ch: + println(x) + case <-ch: + println(0) + case ch <- 1: + println(1) + } +} + +// -------- Type switches -------- + +// NB, reliance on fragile register numbering. +func SimpleTypeSwitch(x interface{}) { + // switch x.(type) { + // case t3 int: println(x) + // case t7 bool: println(x) + // case t10 string: println(t10) + // default: println(x) + // } + switch y := x.(type) { + case nil: + println(y) + case int, bool: + println(y) + case string: + println(y) + default: + println(y) + } +} + +// NB, potentially fragile reliance on register number. +func DuplicateTypesAreNotEliminated(x interface{}) { + // switch x.(type) { + // case t1 string: println(1:int) + // case t5 interface{}: println(t5) + // case t9 int: println(3:int) + // default: return + // } + switch y := x.(type) { + case string: + println(1) + case interface{}: + println(y) + case int: + println(3) // unreachable! + } +} + +// NB, potentially fragile reliance on register number. +func AdHocTypeSwitch(x interface{}) { + // switch x.(type) { + // case t1 int: println(t1) + // case t5 string: println(t5) + // default: print("default":string) + // } + if i, ok := x.(int); ok { + println(i) + } else if s, ok := x.(string); ok { + println(s) + } else { + print("default") + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/visit.go b/vendor/golang.org/x/tools/go/ssa/ssautil/visit.go new file mode 100644 index 0000000..3424e8a --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/visit.go @@ -0,0 +1,79 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil // import "golang.org/x/tools/go/ssa/ssautil" + +import "golang.org/x/tools/go/ssa" + +// This file defines utilities for visiting the SSA representation of +// a Program. +// +// TODO(adonovan): test coverage. + +// AllFunctions finds and returns the set of functions potentially +// needed by program prog, as determined by a simple linker-style +// reachability algorithm starting from the members and method-sets of +// each package. The result may include anonymous functions and +// synthetic wrappers. +// +// Precondition: all packages are built. +// +func AllFunctions(prog *ssa.Program) map[*ssa.Function]bool { + visit := visitor{ + prog: prog, + seen: make(map[*ssa.Function]bool), + } + visit.program() + return visit.seen +} + +type visitor struct { + prog *ssa.Program + seen map[*ssa.Function]bool +} + +func (visit *visitor) program() { + for _, pkg := range visit.prog.AllPackages() { + for _, mem := range pkg.Members { + if fn, ok := mem.(*ssa.Function); ok { + visit.function(fn) + } + } + } + for _, T := range visit.prog.RuntimeTypes() { + mset := visit.prog.MethodSets.MethodSet(T) + for i, n := 0, mset.Len(); i < n; i++ { + visit.function(visit.prog.MethodValue(mset.At(i))) + } + } +} + +func (visit *visitor) function(fn *ssa.Function) { + if !visit.seen[fn] { + visit.seen[fn] = true + var buf [10]*ssa.Value // avoid alloc in common case + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + for _, op := range instr.Operands(buf[:0]) { + if fn, ok := (*op).(*ssa.Function); ok { + visit.function(fn) + } + } + } + } + } +} + +// MainPackages returns the subset of the specified packages +// named "main" that define a main function. +// The result may include synthetic "testmain" packages. +func MainPackages(pkgs []*ssa.Package) []*ssa.Package { + var mains []*ssa.Package + for _, pkg := range pkgs { + if pkg.Pkg.Name() == "main" && pkg.Func("main") != nil { + mains = append(mains, pkg) + } + } + return mains +} diff --git a/vendor/golang.org/x/tools/go/ssa/stdlib_test.go b/vendor/golang.org/x/tools/go/ssa/stdlib_test.go new file mode 100644 index 0000000..f7e0f86 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/stdlib_test.go @@ -0,0 +1,151 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Incomplete source tree on Android. + +// +build !android + +package ssa_test + +// This file runs the SSA builder in sanity-checking mode on all +// packages beneath $GOROOT and prints some summary information. +// +// Run with "go test -cpu=8 to" set GOMAXPROCS. + +import ( + "go/ast" + "go/build" + "go/token" + "runtime" + "testing" + "time" + + "golang.org/x/tools/go/buildutil" + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +// Skip the set of packages that transitively depend on +// cmd/internal/objfile, which uses vendoring, +// which go/loader does not yet support. +// TODO(adonovan): add support for vendoring and delete this. +var skip = map[string]bool{ + "cmd/addr2line": true, + "cmd/internal/objfile": true, + "cmd/nm": true, + "cmd/objdump": true, + "cmd/pprof": true, +} + +func bytesAllocated() uint64 { + runtime.GC() + var stats runtime.MemStats + runtime.ReadMemStats(&stats) + return stats.Alloc +} + +func TestStdlib(t *testing.T) { + if testing.Short() { + t.Skip("skipping in short mode; too slow (golang.org/issue/14113)") + } + // Load, parse and type-check the program. + t0 := time.Now() + alloc0 := bytesAllocated() + + // Load, parse and type-check the program. + ctxt := build.Default // copy + ctxt.GOPATH = "" // disable GOPATH + conf := loader.Config{Build: &ctxt} + for _, path := range buildutil.AllPackages(conf.Build) { + if skip[path] { + continue + } + conf.ImportWithTests(path) + } + + iprog, err := conf.Load() + if err != nil { + t.Fatalf("Load failed: %v", err) + } + + t1 := time.Now() + alloc1 := bytesAllocated() + + // Create SSA packages. + var mode ssa.BuilderMode + // Comment out these lines during benchmarking. Approx SSA build costs are noted. + mode |= ssa.SanityCheckFunctions // + 2% space, + 4% time + mode |= ssa.GlobalDebug // +30% space, +18% time + prog := ssautil.CreateProgram(iprog, mode) + + t2 := time.Now() + + // Build SSA. + prog.Build() + + t3 := time.Now() + alloc3 := bytesAllocated() + + numPkgs := len(prog.AllPackages()) + if want := 140; numPkgs < want { + t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want) + } + + // Keep iprog reachable until after we've measured memory usage. + if len(iprog.AllPackages) == 0 { + panic("unreachable") + } + + allFuncs := ssautil.AllFunctions(prog) + + // Check that all non-synthetic functions have distinct names. + // Synthetic wrappers for exported methods should be distinct too, + // except for unexported ones (explained at (*Function).RelString). + byName := make(map[string]*ssa.Function) + for fn := range allFuncs { + if fn.Synthetic == "" || ast.IsExported(fn.Name()) { + str := fn.String() + prev := byName[str] + byName[str] = fn + if prev != nil { + t.Errorf("%s: duplicate function named %s", + prog.Fset.Position(fn.Pos()), str) + t.Errorf("%s: (previously defined here)", + prog.Fset.Position(prev.Pos())) + } + } + } + + // Dump some statistics. + var numInstrs int + for fn := range allFuncs { + for _, b := range fn.Blocks { + numInstrs += len(b.Instrs) + } + } + + // determine line count + var lineCount int + prog.Fset.Iterate(func(f *token.File) bool { + lineCount += f.LineCount() + return true + }) + + // NB: when benchmarking, don't forget to clear the debug + + // sanity builder flags for better performance. + + t.Log("GOMAXPROCS: ", runtime.GOMAXPROCS(0)) + t.Log("#Source lines: ", lineCount) + t.Log("Load/parse/typecheck: ", t1.Sub(t0)) + t.Log("SSA create: ", t2.Sub(t1)) + t.Log("SSA build: ", t3.Sub(t2)) + + // SSA stats: + t.Log("#Packages: ", numPkgs) + t.Log("#Functions: ", len(allFuncs)) + t.Log("#Instructions: ", numInstrs) + t.Log("#MB AST+types: ", int64(alloc1-alloc0)/1e6) + t.Log("#MB SSA: ", int64(alloc3-alloc1)/1e6) +} diff --git a/vendor/golang.org/x/tools/go/ssa/testdata/objlookup.go b/vendor/golang.org/x/tools/go/ssa/testdata/objlookup.go new file mode 100644 index 0000000..1aaa417 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/testdata/objlookup.go @@ -0,0 +1,160 @@ +//+build ignore + +package main + +// This file is the input to TestObjValueLookup in source_test.go, +// which ensures that each occurrence of an ident defining or +// referring to a func, var or const object can be mapped to its +// corresponding SSA Value. +// +// For every reference to a var object, we use annotations in comments +// to denote both the expected SSA Value kind, and whether to expect +// its value (x) or its address (&x). +// +// For const and func objects, the results don't vary by reference and +// are always values not addresses, so no annotations are needed. The +// declaration is enough. + +import "fmt" +import "os" + +type J int + +func (*J) method() {} + +const globalConst = 0 + +var globalVar int // &globalVar::Global + +func globalFunc() {} + +type I interface { + interfaceMethod() +} + +type S struct { + x int // x::nil +} + +func main() { + print(globalVar) // globalVar::UnOp + globalVar = 1 // globalVar::Const + + var v0 int = 1 // v0::Const (simple local value spec) + if v0 > 0 { // v0::Const + v0 = 2 // v0::Const + } + print(v0) // v0::Phi + + // v1 is captured and thus implicitly address-taken. + var v1 int = 1 // v1::Const + v1 = 2 // v1::Const + fmt.Println(v1) // v1::UnOp (load) + f := func(param int) { // f::MakeClosure param::Parameter + if y := 1; y > 0 { // y::Const + print(v1, param) // v1::UnOp (load) param::Parameter + } + param = 2 // param::Const + println(param) // param::Const + } + + f(0) // f::MakeClosure + + var v2 int // v2::Const (implicitly zero-initialized local value spec) + print(v2) // v2::Const + + m := make(map[string]int) // m::MakeMap + + // Local value spec with multi-valued RHS: + var v3, v4 = m[""] // v3::Extract v4::Extract m::MakeMap + print(v3) // v3::Extract + print(v4) // v4::Extract + + v3++ // v3::BinOp (assign with op) + v3 += 2 // v3::BinOp (assign with op) + + v5, v6 := false, "" // v5::Const v6::Const (defining assignment) + print(v5) // v5::Const + print(v6) // v6::Const + + var v7 S // &v7::Alloc + v7.x = 1 // &v7::Alloc &x::FieldAddr + print(v7.x) // &v7::Alloc &x::FieldAddr + + var v8 [1]int // &v8::Alloc + v8[0] = 0 // &v8::Alloc + print(v8[:]) // &v8::Alloc + _ = v8[0] // &v8::Alloc + _ = v8[:][0] // &v8::Alloc + v8ptr := &v8 // v8ptr::Alloc &v8::Alloc + _ = v8ptr[0] // v8ptr::Alloc + _ = *v8ptr // v8ptr::Alloc + + v8a := make([]int, 1) // v8a::Slice + v8a[0] = 0 // v8a::Slice + print(v8a[:]) // v8a::Slice + + v9 := S{} // &v9::Alloc + + v10 := &v9 // v10::Alloc &v9::Alloc + _ = v10 // v10::Alloc + + var v11 *J = nil // v11::Const + v11.method() // v11::Const + + var v12 J // &v12::Alloc + v12.method() // &v12::Alloc (implicitly address-taken) + + // NB, in the following, 'method' resolves to the *types.Func + // of (*J).method, so it doesn't help us locate the specific + // ssa.Values here: a bound-method closure and a promotion + // wrapper. + _ = v11.method // v11::Const + _ = (*struct{ J }).method // J::nil + + // These vars are not optimised away. + if false { + v13 := 0 // v13::Const + println(v13) // v13::Const + } + + switch x := 1; x { // x::Const + case v0: // v0::Phi + } + + for k, v := range m { // k::Extract v::Extract m::MakeMap + _ = k // k::Extract + v++ // v::BinOp + } + + if y := 0; y > 1 { // y::Const y::Const + } + + var i interface{} // i::Const (nil interface) + i = 1 // i::MakeInterface + switch i := i.(type) { // i::MakeInterface i::MakeInterface + case int: + println(i) // i::Extract + } + + ch := make(chan int) // ch::MakeChan + select { + case x := <-ch: // x::UnOp (receive) ch::MakeChan + _ = x // x::UnOp + } + + // .Op is an inter-package FieldVal-selection. + var err os.PathError // &err::Alloc + _ = err.Op // &err::Alloc &Op::FieldAddr + _ = &err.Op // &err::Alloc &Op::FieldAddr + + // Exercise corner-cases of lvalues vs rvalues. + // (Guessing IsAddr from the 'pointerness' won't cut it here.) + type N *N + var n N // n::Const + n1 := n // n1::Const n::Const + n2 := &n1 // n2::Alloc &n1::Alloc + n3 := *n2 // n3::UnOp n2::Alloc + n4 := **n3 // n4::UnOp n3::UnOp + _ = n4 // n4::UnOp +} diff --git a/vendor/golang.org/x/tools/go/ssa/testdata/structconv.go b/vendor/golang.org/x/tools/go/ssa/testdata/structconv.go new file mode 100644 index 0000000..3126469 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/testdata/structconv.go @@ -0,0 +1,24 @@ +//+build ignore + +// This file is the input to TestValueForExprStructConv in identical_test.go, +// which uses the same framework as TestValueForExpr does in source_test.go. +// +// In Go 1.8, struct conversions are permitted even when the struct types have +// different tags. This wasn't permitted in earlier versions of Go, so this file +// exists separately from valueforexpr.go to just test this behavior in Go 1.8 +// and later. + +package main + +type t1 struct { + x int +} +type t2 struct { + x int `tag` +} + +func main() { + var tv1 t1 + var tv2 t2 = /*@ChangeType*/ (t2(tv1)) + _ = tv2 +} diff --git a/vendor/golang.org/x/tools/go/ssa/testdata/valueforexpr.go b/vendor/golang.org/x/tools/go/ssa/testdata/valueforexpr.go new file mode 100644 index 0000000..4a2cb85 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/testdata/valueforexpr.go @@ -0,0 +1,152 @@ +//+build ignore + +package main + +// This file is the input to TestValueForExpr in source_test.go, which +// ensures that each expression e immediately following a /*@kind*/(x) +// annotation, when passed to Function.ValueForExpr(e), returns a +// non-nil Value of the same type as e and of kind 'kind'. + +func f(spilled, unspilled int) { + _ = /*@UnOp*/ (spilled) + _ = /*@Parameter*/ (unspilled) + _ = /*@<nil>*/ (1 + 2) // (constant) + i := 0 + + f := func() (int, int) { return 0, 0 } + + /*@Call*/ (print( /*@BinOp*/ (i + 1))) + _, _ = /*@Call*/ (f()) + ch := /*@MakeChan*/ (make(chan int)) + /*@UnOp*/ (<-ch) + x := /*@UnOp*/ (<-ch) + _ = x + select { + case /*@Extract*/ (<-ch): + case x := /*@Extract*/ (<-ch): + _ = x + } + defer /*@Function*/ (func() { + })() + go /*@Function*/ (func() { + })() + y := 0 + if true && /*@BinOp*/ (bool(y > 0)) { + y = 1 + } + _ = /*@Phi*/ (y) + map1 := /*@MakeMap*/ (make(map[string]string)) + _ = map1 + _ = /*@Slice*/ (make([]int, 0)) + _ = /*@MakeClosure*/ (func() { print(spilled) }) + + sl := []int{} + _ = /*@Slice*/ (sl[:0]) + + _ = /*@<nil>*/ (new(int)) // optimized away + tmp := /*@Alloc*/ (new(int)) + _ = tmp + var iface interface{} + _ = /*@TypeAssert*/ (iface.(int)) + _ = /*@UnOp*/ (sl[0]) + _ = /*@IndexAddr*/ (&sl[0]) + _ = /*@Index*/ ([2]int{}[0]) + var p *int + _ = /*@UnOp*/ (*p) + + _ = /*@UnOp*/ (global) + /*@UnOp*/ (global)[""] = "" + /*@Global*/ (global) = map[string]string{} + + var local t + /*UnOp*/ (local.x) = 1 + + // Exercise corner-cases of lvalues vs rvalues. + type N *N + var n N + /*@UnOp*/ (n) = /*@UnOp*/ (n) + /*@ChangeType*/ (n) = /*@Alloc*/ (&n) + /*@UnOp*/ (n) = /*@UnOp*/ (*n) + /*@UnOp*/ (n) = /*@UnOp*/ (**n) +} + +func complit() { + // Composite literals. + // We get different results for + // - composite literal as value (e.g. operand to print) + // - composite literal initializer for addressable value + // - composite literal value assigned to blank var + + // 1. Slices + print( /*@Slice*/ ([]int{})) + print( /*@Alloc*/ (&[]int{})) + print(& /*@Slice*/ ([]int{})) + + sl1 := /*@Slice*/ ([]int{}) + sl2 := /*@Alloc*/ (&[]int{}) + sl3 := & /*@Slice*/ ([]int{}) + _, _, _ = sl1, sl2, sl3 + + _ = /*@Slice*/ ([]int{}) + _ = /*@<nil>*/ (& /*@Slice*/ ([]int{})) // & optimized away + _ = & /*@Slice*/ ([]int{}) + + // 2. Arrays + print( /*@UnOp*/ ([1]int{})) + print( /*@Alloc*/ (&[1]int{})) + print(& /*@Alloc*/ ([1]int{})) + + arr1 := /*@Alloc*/ ([1]int{}) + arr2 := /*@Alloc*/ (&[1]int{}) + arr3 := & /*@Alloc*/ ([1]int{}) + _, _, _ = arr1, arr2, arr3 + + _ = /*@UnOp*/ ([1]int{}) + _ = /*@Alloc*/ (& /*@Alloc*/ ([1]int{})) + _ = & /*@Alloc*/ ([1]int{}) + + // 3. Maps + type M map[int]int + print( /*@MakeMap*/ (M{})) + print( /*@Alloc*/ (&M{})) + print(& /*@MakeMap*/ (M{})) + + m1 := /*@MakeMap*/ (M{}) + m2 := /*@Alloc*/ (&M{}) + m3 := & /*@MakeMap*/ (M{}) + _, _, _ = m1, m2, m3 + + _ = /*@MakeMap*/ (M{}) + _ = /*@<nil>*/ (& /*@MakeMap*/ (M{})) // & optimized away + _ = & /*@MakeMap*/ (M{}) + + // 4. Structs + print( /*@UnOp*/ (struct{}{})) + print( /*@Alloc*/ (&struct{}{})) + print(& /*@Alloc*/ (struct{}{})) + + s1 := /*@Alloc*/ (struct{}{}) + s2 := /*@Alloc*/ (&struct{}{}) + s3 := & /*@Alloc*/ (struct{}{}) + _, _, _ = s1, s2, s3 + + _ = /*@UnOp*/ (struct{}{}) + _ = /*@Alloc*/ (& /*@Alloc*/ (struct{}{})) + _ = & /*@Alloc*/ (struct{}{}) +} + +type t struct{ x int } + +// Ensure we can locate methods of named types. +func (t) f(param int) { + _ = /*@Parameter*/ (param) +} + +// Ensure we can locate init functions. +func init() { + m := /*@MakeMap*/ (make(map[string]string)) + _ = m +} + +// Ensure we can locate variables in initializer expressions. +var global = /*@MakeMap*/ (make(map[string]string)) diff --git a/vendor/golang.org/x/tools/go/ssa/testmain.go b/vendor/golang.org/x/tools/go/ssa/testmain.go new file mode 100644 index 0000000..ea232ad --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/testmain.go @@ -0,0 +1,267 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// CreateTestMainPackage synthesizes a main package that runs all the +// tests of the supplied packages. +// It is closely coupled to $GOROOT/src/cmd/go/test.go and $GOROOT/src/testing. +// +// TODO(adonovan): this file no longer needs to live in the ssa package. +// Move it to ssautil. + +import ( + "bytes" + "fmt" + "go/ast" + "go/parser" + "go/types" + "log" + "os" + "strings" + "text/template" +) + +// FindTests returns the Test, Benchmark, and Example functions +// (as defined by "go test") defined in the specified package, +// and its TestMain function, if any. +func FindTests(pkg *Package) (tests, benchmarks, examples []*Function, main *Function) { + prog := pkg.Prog + + // The first two of these may be nil: if the program doesn't import "testing", + // it can't contain any tests, but it may yet contain Examples. + var testSig *types.Signature // func(*testing.T) + var benchmarkSig *types.Signature // func(*testing.B) + var exampleSig = types.NewSignature(nil, nil, nil, false) // func() + + // Obtain the types from the parameters of testing.MainStart. + if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil { + mainStart := testingPkg.Func("MainStart") + params := mainStart.Signature.Params() + testSig = funcField(params.At(1).Type()) + benchmarkSig = funcField(params.At(2).Type()) + + // Does the package define this function? + // func TestMain(*testing.M) + if f := pkg.Func("TestMain"); f != nil { + sig := f.Type().(*types.Signature) + starM := mainStart.Signature.Results().At(0).Type() // *testing.M + if sig.Results().Len() == 0 && + sig.Params().Len() == 1 && + types.Identical(sig.Params().At(0).Type(), starM) { + main = f + } + } + } + + // TODO(adonovan): use a stable order, e.g. lexical. + for _, mem := range pkg.Members { + if f, ok := mem.(*Function); ok && + ast.IsExported(f.Name()) && + strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") { + + switch { + case testSig != nil && isTestSig(f, "Test", testSig): + tests = append(tests, f) + case benchmarkSig != nil && isTestSig(f, "Benchmark", benchmarkSig): + benchmarks = append(benchmarks, f) + case isTestSig(f, "Example", exampleSig): + examples = append(examples, f) + default: + continue + } + } + } + return +} + +// Like isTest, but checks the signature too. +func isTestSig(f *Function, prefix string, sig *types.Signature) bool { + return isTest(f.Name(), prefix) && types.Identical(f.Signature, sig) +} + +// Given the type of one of the three slice parameters of testing.Main, +// returns the function type. +func funcField(slice types.Type) *types.Signature { + return slice.(*types.Slice).Elem().Underlying().(*types.Struct).Field(1).Type().(*types.Signature) +} + +// isTest tells whether name looks like a test (or benchmark, according to prefix). +// It is a Test (say) if there is a character after Test that is not a lower-case letter. +// We don't want TesticularCancer. +// Plundered from $GOROOT/src/cmd/go/test.go +func isTest(name, prefix string) bool { + if !strings.HasPrefix(name, prefix) { + return false + } + if len(name) == len(prefix) { // "Test" is ok + return true + } + return ast.IsExported(name[len(prefix):]) +} + +// CreateTestMainPackage creates and returns a synthetic "testmain" +// package for the specified package if it defines tests, benchmarks or +// executable examples, or nil otherwise. The new package is named +// "main" and provides a function named "main" that runs the tests, +// similar to the one that would be created by the 'go test' tool. +// +// Subsequent calls to prog.AllPackages include the new package. +// The package pkg must belong to the program prog. +func (prog *Program) CreateTestMainPackage(pkg *Package) *Package { + if pkg.Prog != prog { + log.Fatal("Package does not belong to Program") + } + + // Template data + var data struct { + Pkg *Package + Tests, Benchmarks, Examples []*Function + Main *Function + Go18 bool + } + data.Pkg = pkg + + // Enumerate tests. + data.Tests, data.Benchmarks, data.Examples, data.Main = FindTests(pkg) + if data.Main == nil && + data.Tests == nil && data.Benchmarks == nil && data.Examples == nil { + return nil + } + + // Synthesize source for testmain package. + path := pkg.Pkg.Path() + "$testmain" + tmpl := testmainTmpl + if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil { + // In Go 1.8, testing.MainStart's first argument is an interface, not a func. + data.Go18 = types.IsInterface(testingPkg.Func("MainStart").Signature.Params().At(0).Type()) + } else { + // The program does not import "testing", but FindTests + // returned non-nil, which must mean there were Examples + // but no Test, Benchmark, or TestMain functions. + + // We'll simply call them from testmain.main; this will + // ensure they don't panic, but will not check any + // "Output:" comments. + // (We should not execute an Example that has no + // "Output:" comment, but it's impossible to tell here.) + tmpl = examplesOnlyTmpl + } + var buf bytes.Buffer + if err := tmpl.Execute(&buf, data); err != nil { + log.Fatalf("internal error expanding template for %s: %v", path, err) + } + if false { // debugging + fmt.Fprintln(os.Stderr, buf.String()) + } + + // Parse and type-check the testmain package. + f, err := parser.ParseFile(prog.Fset, path+".go", &buf, parser.Mode(0)) + if err != nil { + log.Fatalf("internal error parsing %s: %v", path, err) + } + conf := types.Config{ + DisableUnusedImportCheck: true, + Importer: importer{pkg}, + } + files := []*ast.File{f} + info := &types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + } + testmainPkg, err := conf.Check(path, prog.Fset, files, info) + if err != nil { + log.Fatalf("internal error type-checking %s: %v", path, err) + } + + // Create and build SSA code. + testmain := prog.CreatePackage(testmainPkg, files, info, false) + testmain.SetDebugMode(false) + testmain.Build() + testmain.Func("main").Synthetic = "test main function" + testmain.Func("init").Synthetic = "package initializer" + return testmain +} + +// An implementation of types.Importer for an already loaded SSA program. +type importer struct { + pkg *Package // package under test; may be non-importable +} + +func (imp importer) Import(path string) (*types.Package, error) { + if p := imp.pkg.Prog.ImportedPackage(path); p != nil { + return p.Pkg, nil + } + if path == imp.pkg.Pkg.Path() { + return imp.pkg.Pkg, nil + } + return nil, fmt.Errorf("not found") // can't happen +} + +var testmainTmpl = template.Must(template.New("testmain").Parse(` +package main + +import "io" +import "os" +import "testing" +import p {{printf "%q" .Pkg.Pkg.Path}} + +{{if .Go18}} +type deps struct{} + +func (deps) ImportPath() string { return "" } +func (deps) MatchString(pat, str string) (bool, error) { return true, nil } +func (deps) StartCPUProfile(io.Writer) error { return nil } +func (deps) StartTestLog(io.Writer) {} +func (deps) StopCPUProfile() {} +func (deps) StopTestLog() error { return nil } +func (deps) WriteHeapProfile(io.Writer) error { return nil } +func (deps) WriteProfileTo(string, io.Writer, int) error { return nil } + +var match deps +{{else}} +func match(_, _ string) (bool, error) { return true, nil } +{{end}} + +func main() { + tests := []testing.InternalTest{ +{{range .Tests}} + { {{printf "%q" .Name}}, p.{{.Name}} }, +{{end}} + } + benchmarks := []testing.InternalBenchmark{ +{{range .Benchmarks}} + { {{printf "%q" .Name}}, p.{{.Name}} }, +{{end}} + } + examples := []testing.InternalExample{ +{{range .Examples}} + {Name: {{printf "%q" .Name}}, F: p.{{.Name}}}, +{{end}} + } + m := testing.MainStart(match, tests, benchmarks, examples) +{{with .Main}} + p.{{.Name}}(m) +{{else}} + os.Exit(m.Run()) +{{end}} +} + +`)) + +var examplesOnlyTmpl = template.Must(template.New("examples").Parse(` +package main + +import p {{printf "%q" .Pkg.Pkg.Path}} + +func main() { +{{range .Examples}} + p.{{.Name}}() +{{end}} +} +`)) diff --git a/vendor/golang.org/x/tools/go/ssa/testmain_test.go b/vendor/golang.org/x/tools/go/ssa/testmain_test.go new file mode 100644 index 0000000..e24b23b --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/testmain_test.go @@ -0,0 +1,124 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa_test + +// Tests of FindTests. CreateTestMainPackage is tested via the interpreter. +// TODO(adonovan): test the 'pkgs' result from FindTests. + +import ( + "fmt" + "sort" + "testing" + + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +func create(t *testing.T, content string) *ssa.Package { + var conf loader.Config + f, err := conf.ParseFile("foo_test.go", content) + if err != nil { + t.Fatal(err) + } + conf.CreateFromFiles("foo", f) + + lprog, err := conf.Load() + if err != nil { + t.Fatal(err) + } + + // We needn't call Build. + foo := lprog.Package("foo").Pkg + return ssautil.CreateProgram(lprog, ssa.SanityCheckFunctions).Package(foo) +} + +func TestFindTests(t *testing.T) { + test := ` +package foo + +import "testing" + +type T int + +// Tests: +func Test(t *testing.T) {} +func TestA(t *testing.T) {} +func TestB(t *testing.T) {} + +// Not tests: +func testC(t *testing.T) {} +func TestD() {} +func testE(t *testing.T) int { return 0 } +func (T) Test(t *testing.T) {} + +// Benchmarks: +func Benchmark(*testing.B) {} +func BenchmarkA(b *testing.B) {} +func BenchmarkB(*testing.B) {} + +// Not benchmarks: +func benchmarkC(t *testing.T) {} +func BenchmarkD() {} +func benchmarkE(t *testing.T) int { return 0 } +func (T) Benchmark(t *testing.T) {} + +// Examples: +func Example() {} +func ExampleA() {} + +// Not examples: +func exampleC() {} +func ExampleD(t *testing.T) {} +func exampleE() int { return 0 } +func (T) Example() {} +` + pkg := create(t, test) + tests, benchmarks, examples, _ := ssa.FindTests(pkg) + + sort.Sort(funcsByPos(tests)) + if got, want := fmt.Sprint(tests), "[foo.Test foo.TestA foo.TestB]"; got != want { + t.Errorf("FindTests.tests = %s, want %s", got, want) + } + + sort.Sort(funcsByPos(benchmarks)) + if got, want := fmt.Sprint(benchmarks), "[foo.Benchmark foo.BenchmarkA foo.BenchmarkB]"; got != want { + t.Errorf("FindTests.benchmarks = %s, want %s", got, want) + } + + sort.Sort(funcsByPos(examples)) + if got, want := fmt.Sprint(examples), "[foo.Example foo.ExampleA]"; got != want { + t.Errorf("FindTests examples = %s, want %s", got, want) + } +} + +func TestFindTestsTesting(t *testing.T) { + test := ` +package foo + +// foo does not import "testing", but defines Examples. + +func Example() {} +func ExampleA() {} +` + pkg := create(t, test) + tests, benchmarks, examples, _ := ssa.FindTests(pkg) + if len(tests) > 0 { + t.Errorf("FindTests.tests = %s, want none", tests) + } + if len(benchmarks) > 0 { + t.Errorf("FindTests.benchmarks = %s, want none", benchmarks) + } + sort.Sort(funcsByPos(examples)) + if got, want := fmt.Sprint(examples), "[foo.Example foo.ExampleA]"; got != want { + t.Errorf("FindTests examples = %s, want %s", got, want) + } +} + +type funcsByPos []*ssa.Function + +func (p funcsByPos) Len() int { return len(p) } +func (p funcsByPos) Less(i, j int) bool { return p[i].Pos() < p[j].Pos() } +func (p funcsByPos) Swap(i, j int) { p[i], p[j] = p[j], p[i] } diff --git a/vendor/golang.org/x/tools/go/ssa/util.go b/vendor/golang.org/x/tools/go/ssa/util.go new file mode 100644 index 0000000..ddb1184 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/util.go @@ -0,0 +1,119 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines a number of miscellaneous utility functions. + +import ( + "fmt" + "go/ast" + "go/token" + "go/types" + "io" + "os" + + "golang.org/x/tools/go/ast/astutil" +) + +//// AST utilities + +func unparen(e ast.Expr) ast.Expr { return astutil.Unparen(e) } + +// isBlankIdent returns true iff e is an Ident with name "_". +// They have no associated types.Object, and thus no type. +// +func isBlankIdent(e ast.Expr) bool { + id, ok := e.(*ast.Ident) + return ok && id.Name == "_" +} + +//// Type utilities. Some of these belong in go/types. + +// isPointer returns true for types whose underlying type is a pointer. +func isPointer(typ types.Type) bool { + _, ok := typ.Underlying().(*types.Pointer) + return ok +} + +func isInterface(T types.Type) bool { return types.IsInterface(T) } + +// deref returns a pointer's element type; otherwise it returns typ. +func deref(typ types.Type) types.Type { + if p, ok := typ.Underlying().(*types.Pointer); ok { + return p.Elem() + } + return typ +} + +// recvType returns the receiver type of method obj. +func recvType(obj *types.Func) types.Type { + return obj.Type().(*types.Signature).Recv().Type() +} + +// DefaultType returns the default "typed" type for an "untyped" type; +// it returns the incoming type for all other types. The default type +// for untyped nil is untyped nil. +// +// Exported to ssa/interp. +// +// TODO(adonovan): use go/types.DefaultType after 1.8. +// +func DefaultType(typ types.Type) types.Type { + if t, ok := typ.(*types.Basic); ok { + k := t.Kind() + switch k { + case types.UntypedBool: + k = types.Bool + case types.UntypedInt: + k = types.Int + case types.UntypedRune: + k = types.Rune + case types.UntypedFloat: + k = types.Float64 + case types.UntypedComplex: + k = types.Complex128 + case types.UntypedString: + k = types.String + } + typ = types.Typ[k] + } + return typ +} + +// logStack prints the formatted "start" message to stderr and +// returns a closure that prints the corresponding "end" message. +// Call using 'defer logStack(...)()' to show builder stack on panic. +// Don't forget trailing parens! +// +func logStack(format string, args ...interface{}) func() { + msg := fmt.Sprintf(format, args...) + io.WriteString(os.Stderr, msg) + io.WriteString(os.Stderr, "\n") + return func() { + io.WriteString(os.Stderr, msg) + io.WriteString(os.Stderr, " end\n") + } +} + +// newVar creates a 'var' for use in a types.Tuple. +func newVar(name string, typ types.Type) *types.Var { + return types.NewParam(token.NoPos, nil, name, typ) +} + +// anonVar creates an anonymous 'var' for use in a types.Tuple. +func anonVar(typ types.Type) *types.Var { + return newVar("", typ) +} + +var lenResults = types.NewTuple(anonVar(tInt)) + +// makeLen returns the len builtin specialized to type func(T)int. +func makeLen(T types.Type) *Builtin { + lenParams := types.NewTuple(anonVar(T)) + return &Builtin{ + name: "len", + sig: types.NewSignature(nil, lenParams, lenResults, false), + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/wrappers.go b/vendor/golang.org/x/tools/go/ssa/wrappers.go new file mode 100644 index 0000000..701dd90 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/wrappers.go @@ -0,0 +1,294 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines synthesis of Functions that delegate to declared +// methods; they come in three kinds: +// +// (1) wrappers: methods that wrap declared methods, performing +// implicit pointer indirections and embedded field selections. +// +// (2) thunks: funcs that wrap declared methods. Like wrappers, +// thunks perform indirections and field selections. The thunk's +// first parameter is used as the receiver for the method call. +// +// (3) bounds: funcs that wrap declared methods. The bound's sole +// free variable, supplied by a closure, is used as the receiver +// for the method call. No indirections or field selections are +// performed since they can be done before the call. + +import ( + "fmt" + + "go/types" +) + +// -- wrappers ----------------------------------------------------------- + +// makeWrapper returns a synthetic method that delegates to the +// declared method denoted by meth.Obj(), first performing any +// necessary pointer indirections or field selections implied by meth. +// +// The resulting method's receiver type is meth.Recv(). +// +// This function is versatile but quite subtle! Consider the +// following axes of variation when making changes: +// - optional receiver indirection +// - optional implicit field selections +// - meth.Obj() may denote a concrete or an interface method +// - the result may be a thunk or a wrapper. +// +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +// +func makeWrapper(prog *Program, sel *types.Selection) *Function { + obj := sel.Obj().(*types.Func) // the declared function + sig := sel.Type().(*types.Signature) // type of this wrapper + + var recv *types.Var // wrapper's receiver or thunk's params[0] + name := obj.Name() + var description string + var start int // first regular param + if sel.Kind() == types.MethodExpr { + name += "$thunk" + description = "thunk" + recv = sig.Params().At(0) + start = 1 + } else { + description = "wrapper" + recv = sig.Recv() + } + + description = fmt.Sprintf("%s for %s", description, sel.Obj()) + if prog.mode&LogSource != 0 { + defer logStack("make %s to (%s)", description, recv.Type())() + } + fn := &Function{ + name: name, + method: sel, + object: obj, + Signature: sig, + Synthetic: description, + Prog: prog, + pos: obj.Pos(), + } + fn.startBody() + fn.addSpilledParam(recv) + createParams(fn, start) + + indices := sel.Index() + + var v Value = fn.Locals[0] // spilled receiver + if isPointer(sel.Recv()) { + v = emitLoad(fn, v) + + // For simple indirection wrappers, perform an informative nil-check: + // "value method (T).f called using nil *T pointer" + if len(indices) == 1 && !isPointer(recvType(obj)) { + var c Call + c.Call.Value = &Builtin{ + name: "ssa:wrapnilchk", + sig: types.NewSignature(nil, + types.NewTuple(anonVar(sel.Recv()), anonVar(tString), anonVar(tString)), + types.NewTuple(anonVar(sel.Recv())), false), + } + c.Call.Args = []Value{ + v, + stringConst(deref(sel.Recv()).String()), + stringConst(sel.Obj().Name()), + } + c.setType(v.Type()) + v = fn.emit(&c) + } + } + + // Invariant: v is a pointer, either + // value of *A receiver param, or + // address of A spilled receiver. + + // We use pointer arithmetic (FieldAddr possibly followed by + // Load) in preference to value extraction (Field possibly + // preceded by Load). + + v = emitImplicitSelections(fn, v, indices[:len(indices)-1]) + + // Invariant: v is a pointer, either + // value of implicit *C field, or + // address of implicit C field. + + var c Call + if r := recvType(obj); !isInterface(r) { // concrete method + if !isPointer(r) { + v = emitLoad(fn, v) + } + c.Call.Value = prog.declaredFunc(obj) + c.Call.Args = append(c.Call.Args, v) + } else { + c.Call.Method = obj + c.Call.Value = emitLoad(fn, v) + } + for _, arg := range fn.Params[1:] { + c.Call.Args = append(c.Call.Args, arg) + } + emitTailCall(fn, &c) + fn.finishBody() + return fn +} + +// createParams creates parameters for wrapper method fn based on its +// Signature.Params, which do not include the receiver. +// start is the index of the first regular parameter to use. +// +func createParams(fn *Function, start int) { + var last *Parameter + tparams := fn.Signature.Params() + for i, n := start, tparams.Len(); i < n; i++ { + last = fn.addParamObj(tparams.At(i)) + } + if fn.Signature.Variadic() { + last.typ = types.NewSlice(last.typ) + } +} + +// -- bounds ----------------------------------------------------------- + +// makeBound returns a bound method wrapper (or "bound"), a synthetic +// function that delegates to a concrete or interface method denoted +// by obj. The resulting function has no receiver, but has one free +// variable which will be used as the method's receiver in the +// tail-call. +// +// Use MakeClosure with such a wrapper to construct a bound method +// closure. e.g.: +// +// type T int or: type T interface { meth() } +// func (t T) meth() +// var t T +// f := t.meth +// f() // calls t.meth() +// +// f is a closure of a synthetic wrapper defined as if by: +// +// f := func() { return t.meth() } +// +// Unlike makeWrapper, makeBound need perform no indirection or field +// selections because that can be done before the closure is +// constructed. +// +// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu) +// +func makeBound(prog *Program, obj *types.Func) *Function { + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + fn, ok := prog.bounds[obj] + if !ok { + description := fmt.Sprintf("bound method wrapper for %s", obj) + if prog.mode&LogSource != 0 { + defer logStack("%s", description)() + } + fn = &Function{ + name: obj.Name() + "$bound", + object: obj, + Signature: changeRecv(obj.Type().(*types.Signature), nil), // drop receiver + Synthetic: description, + Prog: prog, + pos: obj.Pos(), + } + + fv := &FreeVar{name: "recv", typ: recvType(obj), parent: fn} + fn.FreeVars = []*FreeVar{fv} + fn.startBody() + createParams(fn, 0) + var c Call + + if !isInterface(recvType(obj)) { // concrete + c.Call.Value = prog.declaredFunc(obj) + c.Call.Args = []Value{fv} + } else { + c.Call.Value = fv + c.Call.Method = obj + } + for _, arg := range fn.Params { + c.Call.Args = append(c.Call.Args, arg) + } + emitTailCall(fn, &c) + fn.finishBody() + + prog.bounds[obj] = fn + } + return fn +} + +// -- thunks ----------------------------------------------------------- + +// makeThunk returns a thunk, a synthetic function that delegates to a +// concrete or interface method denoted by sel.Obj(). The resulting +// function has no receiver, but has an additional (first) regular +// parameter. +// +// Precondition: sel.Kind() == types.MethodExpr. +// +// type T int or: type T interface { meth() } +// func (t T) meth() +// f := T.meth +// var t T +// f(t) // calls t.meth() +// +// f is a synthetic wrapper defined as if by: +// +// f := func(t T) { return t.meth() } +// +// TODO(adonovan): opt: currently the stub is created even when used +// directly in a function call: C.f(i, 0). This is less efficient +// than inlining the stub. +// +// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu) +// +func makeThunk(prog *Program, sel *types.Selection) *Function { + if sel.Kind() != types.MethodExpr { + panic(sel) + } + + key := selectionKey{ + kind: sel.Kind(), + recv: sel.Recv(), + obj: sel.Obj(), + index: fmt.Sprint(sel.Index()), + indirect: sel.Indirect(), + } + + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + + // Canonicalize key.recv to avoid constructing duplicate thunks. + canonRecv, ok := prog.canon.At(key.recv).(types.Type) + if !ok { + canonRecv = key.recv + prog.canon.Set(key.recv, canonRecv) + } + key.recv = canonRecv + + fn, ok := prog.thunks[key] + if !ok { + fn = makeWrapper(prog, sel) + if fn.Signature.Recv() != nil { + panic(fn) // unexpected receiver + } + prog.thunks[key] = fn + } + return fn +} + +func changeRecv(s *types.Signature, recv *types.Var) *types.Signature { + return types.NewSignature(recv, s.Params(), s.Results(), s.Variadic()) +} + +// selectionKey is like types.Selection but a usable map key. +type selectionKey struct { + kind types.SelectionKind + recv types.Type // canonicalized via Program.canon + obj types.Object + index string + indirect bool +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/example_test.go b/vendor/golang.org/x/tools/go/types/typeutil/example_test.go new file mode 100644 index 0000000..86c4d44 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/example_test.go @@ -0,0 +1,67 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil_test + +import ( + "fmt" + "go/ast" + "go/parser" + "go/token" + "go/types" + "sort" + + "golang.org/x/tools/go/types/typeutil" +) + +func ExampleMap() { + const source = `package P + +var X []string +var Y []string + +const p, q = 1.0, 2.0 + +func f(offset int32) (value byte, ok bool) +func g(rune) (uint8, bool) +` + + // Parse and type-check the package. + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "P.go", source, 0) + if err != nil { + panic(err) + } + pkg, err := new(types.Config).Check("P", fset, []*ast.File{f}, nil) + if err != nil { + panic(err) + } + + scope := pkg.Scope() + + // Group names of package-level objects by their type. + var namesByType typeutil.Map // value is []string + for _, name := range scope.Names() { + T := scope.Lookup(name).Type() + + names, _ := namesByType.At(T).([]string) + names = append(names, name) + namesByType.Set(T, names) + } + + // Format, sort, and print the map entries. + var lines []string + namesByType.Iterate(func(T types.Type, names interface{}) { + lines = append(lines, fmt.Sprintf("%s %s", names, T)) + }) + sort.Strings(lines) + for _, line := range lines { + fmt.Println(line) + } + + // Output: + // [X Y] []string + // [f g] func(offset int32) (value byte, ok bool) + // [p q] untyped float +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/imports.go b/vendor/golang.org/x/tools/go/types/typeutil/imports.go new file mode 100644 index 0000000..9c441db --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/imports.go @@ -0,0 +1,31 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil + +import "go/types" + +// Dependencies returns all dependencies of the specified packages. +// +// Dependent packages appear in topological order: if package P imports +// package Q, Q appears earlier than P in the result. +// The algorithm follows import statements in the order they +// appear in the source code, so the result is a total order. +// +func Dependencies(pkgs ...*types.Package) []*types.Package { + var result []*types.Package + seen := make(map[*types.Package]bool) + var visit func(pkgs []*types.Package) + visit = func(pkgs []*types.Package) { + for _, p := range pkgs { + if !seen[p] { + seen[p] = true + visit(p.Imports()) + result = append(result, p) + } + } + } + visit(pkgs) + return result +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/imports_test.go b/vendor/golang.org/x/tools/go/types/typeutil/imports_test.go new file mode 100644 index 0000000..c8ef6d6 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/imports_test.go @@ -0,0 +1,80 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil_test + +import ( + "fmt" + "go/ast" + "go/parser" + "go/token" + "go/types" + "testing" + + "golang.org/x/tools/go/types/typeutil" +) + +type closure map[string]*types.Package + +func (c closure) Import(path string) (*types.Package, error) { return c[path], nil } + +func TestDependencies(t *testing.T) { + packages := make(map[string]*types.Package) + conf := types.Config{ + Importer: closure(packages), + } + fset := token.NewFileSet() + + // All edges go to the right. + // /--D--B--A + // F \_C_/ + // \__E_/ + for i, content := range []string{ + `package a`, + `package c; import (_ "a")`, + `package b; import (_ "a")`, + `package e; import (_ "c")`, + `package d; import (_ "b"; _ "c")`, + `package f; import (_ "d"; _ "e")`, + } { + f, err := parser.ParseFile(fset, fmt.Sprintf("%d.go", i), content, 0) + if err != nil { + t.Fatal(err) + } + pkg, err := conf.Check(f.Name.Name, fset, []*ast.File{f}, nil) + if err != nil { + t.Fatal(err) + } + packages[pkg.Path()] = pkg + } + + for _, test := range []struct { + roots, want string + }{ + {"a", "a"}, + {"b", "ab"}, + {"c", "ac"}, + {"d", "abcd"}, + {"e", "ace"}, + {"f", "abcdef"}, + + {"be", "abce"}, + {"eb", "aceb"}, + {"de", "abcde"}, + {"ed", "acebd"}, + {"ef", "acebdf"}, + } { + var pkgs []*types.Package + for _, r := range test.roots { + pkgs = append(pkgs, packages[string(r)]) + } + var got string + for _, p := range typeutil.Dependencies(pkgs...) { + got += p.Path() + } + if got != test.want { + t.Errorf("Dependencies(%q) = %q, want %q", test.roots, got, test.want) + } + } +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/map.go b/vendor/golang.org/x/tools/go/types/typeutil/map.go new file mode 100644 index 0000000..c7f7545 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/map.go @@ -0,0 +1,313 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package typeutil defines various utilities for types, such as Map, +// a mapping from types.Type to interface{} values. +package typeutil // import "golang.org/x/tools/go/types/typeutil" + +import ( + "bytes" + "fmt" + "go/types" + "reflect" +) + +// Map is a hash-table-based mapping from types (types.Type) to +// arbitrary interface{} values. The concrete types that implement +// the Type interface are pointers. Since they are not canonicalized, +// == cannot be used to check for equivalence, and thus we cannot +// simply use a Go map. +// +// Just as with map[K]V, a nil *Map is a valid empty map. +// +// Not thread-safe. +// +type Map struct { + hasher Hasher // shared by many Maps + table map[uint32][]entry // maps hash to bucket; entry.key==nil means unused + length int // number of map entries +} + +// entry is an entry (key/value association) in a hash bucket. +type entry struct { + key types.Type + value interface{} +} + +// SetHasher sets the hasher used by Map. +// +// All Hashers are functionally equivalent but contain internal state +// used to cache the results of hashing previously seen types. +// +// A single Hasher created by MakeHasher() may be shared among many +// Maps. This is recommended if the instances have many keys in +// common, as it will amortize the cost of hash computation. +// +// A Hasher may grow without bound as new types are seen. Even when a +// type is deleted from the map, the Hasher never shrinks, since other +// types in the map may reference the deleted type indirectly. +// +// Hashers are not thread-safe, and read-only operations such as +// Map.Lookup require updates to the hasher, so a full Mutex lock (not a +// read-lock) is require around all Map operations if a shared +// hasher is accessed from multiple threads. +// +// If SetHasher is not called, the Map will create a private hasher at +// the first call to Insert. +// +func (m *Map) SetHasher(hasher Hasher) { + m.hasher = hasher +} + +// Delete removes the entry with the given key, if any. +// It returns true if the entry was found. +// +func (m *Map) Delete(key types.Type) bool { + if m != nil && m.table != nil { + hash := m.hasher.Hash(key) + bucket := m.table[hash] + for i, e := range bucket { + if e.key != nil && types.Identical(key, e.key) { + // We can't compact the bucket as it + // would disturb iterators. + bucket[i] = entry{} + m.length-- + return true + } + } + } + return false +} + +// At returns the map entry for the given key. +// The result is nil if the entry is not present. +// +func (m *Map) At(key types.Type) interface{} { + if m != nil && m.table != nil { + for _, e := range m.table[m.hasher.Hash(key)] { + if e.key != nil && types.Identical(key, e.key) { + return e.value + } + } + } + return nil +} + +// Set sets the map entry for key to val, +// and returns the previous entry, if any. +func (m *Map) Set(key types.Type, value interface{}) (prev interface{}) { + if m.table != nil { + hash := m.hasher.Hash(key) + bucket := m.table[hash] + var hole *entry + for i, e := range bucket { + if e.key == nil { + hole = &bucket[i] + } else if types.Identical(key, e.key) { + prev = e.value + bucket[i].value = value + return + } + } + + if hole != nil { + *hole = entry{key, value} // overwrite deleted entry + } else { + m.table[hash] = append(bucket, entry{key, value}) + } + } else { + if m.hasher.memo == nil { + m.hasher = MakeHasher() + } + hash := m.hasher.Hash(key) + m.table = map[uint32][]entry{hash: {entry{key, value}}} + } + + m.length++ + return +} + +// Len returns the number of map entries. +func (m *Map) Len() int { + if m != nil { + return m.length + } + return 0 +} + +// Iterate calls function f on each entry in the map in unspecified order. +// +// If f should mutate the map, Iterate provides the same guarantees as +// Go maps: if f deletes a map entry that Iterate has not yet reached, +// f will not be invoked for it, but if f inserts a map entry that +// Iterate has not yet reached, whether or not f will be invoked for +// it is unspecified. +// +func (m *Map) Iterate(f func(key types.Type, value interface{})) { + if m != nil { + for _, bucket := range m.table { + for _, e := range bucket { + if e.key != nil { + f(e.key, e.value) + } + } + } + } +} + +// Keys returns a new slice containing the set of map keys. +// The order is unspecified. +func (m *Map) Keys() []types.Type { + keys := make([]types.Type, 0, m.Len()) + m.Iterate(func(key types.Type, _ interface{}) { + keys = append(keys, key) + }) + return keys +} + +func (m *Map) toString(values bool) string { + if m == nil { + return "{}" + } + var buf bytes.Buffer + fmt.Fprint(&buf, "{") + sep := "" + m.Iterate(func(key types.Type, value interface{}) { + fmt.Fprint(&buf, sep) + sep = ", " + fmt.Fprint(&buf, key) + if values { + fmt.Fprintf(&buf, ": %q", value) + } + }) + fmt.Fprint(&buf, "}") + return buf.String() +} + +// String returns a string representation of the map's entries. +// Values are printed using fmt.Sprintf("%v", v). +// Order is unspecified. +// +func (m *Map) String() string { + return m.toString(true) +} + +// KeysString returns a string representation of the map's key set. +// Order is unspecified. +// +func (m *Map) KeysString() string { + return m.toString(false) +} + +//////////////////////////////////////////////////////////////////////// +// Hasher + +// A Hasher maps each type to its hash value. +// For efficiency, a hasher uses memoization; thus its memory +// footprint grows monotonically over time. +// Hashers are not thread-safe. +// Hashers have reference semantics. +// Call MakeHasher to create a Hasher. +type Hasher struct { + memo map[types.Type]uint32 +} + +// MakeHasher returns a new Hasher instance. +func MakeHasher() Hasher { + return Hasher{make(map[types.Type]uint32)} +} + +// Hash computes a hash value for the given type t such that +// Identical(t, t') => Hash(t) == Hash(t'). +func (h Hasher) Hash(t types.Type) uint32 { + hash, ok := h.memo[t] + if !ok { + hash = h.hashFor(t) + h.memo[t] = hash + } + return hash +} + +// hashString computes the Fowler–Noll–Vo hash of s. +func hashString(s string) uint32 { + var h uint32 + for i := 0; i < len(s); i++ { + h ^= uint32(s[i]) + h *= 16777619 + } + return h +} + +// hashFor computes the hash of t. +func (h Hasher) hashFor(t types.Type) uint32 { + // See Identical for rationale. + switch t := t.(type) { + case *types.Basic: + return uint32(t.Kind()) + + case *types.Array: + return 9043 + 2*uint32(t.Len()) + 3*h.Hash(t.Elem()) + + case *types.Slice: + return 9049 + 2*h.Hash(t.Elem()) + + case *types.Struct: + var hash uint32 = 9059 + for i, n := 0, t.NumFields(); i < n; i++ { + f := t.Field(i) + if f.Anonymous() { + hash += 8861 + } + hash += hashString(t.Tag(i)) + hash += hashString(f.Name()) // (ignore f.Pkg) + hash += h.Hash(f.Type()) + } + return hash + + case *types.Pointer: + return 9067 + 2*h.Hash(t.Elem()) + + case *types.Signature: + var hash uint32 = 9091 + if t.Variadic() { + hash *= 8863 + } + return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results()) + + case *types.Interface: + var hash uint32 = 9103 + for i, n := 0, t.NumMethods(); i < n; i++ { + // See go/types.identicalMethods for rationale. + // Method order is not significant. + // Ignore m.Pkg(). + m := t.Method(i) + hash += 3*hashString(m.Name()) + 5*h.Hash(m.Type()) + } + return hash + + case *types.Map: + return 9109 + 2*h.Hash(t.Key()) + 3*h.Hash(t.Elem()) + + case *types.Chan: + return 9127 + 2*uint32(t.Dir()) + 3*h.Hash(t.Elem()) + + case *types.Named: + // Not safe with a copying GC; objects may move. + return uint32(reflect.ValueOf(t.Obj()).Pointer()) + + case *types.Tuple: + return h.hashTuple(t) + } + panic(t) +} + +func (h Hasher) hashTuple(tuple *types.Tuple) uint32 { + // See go/types.identicalTypes for rationale. + n := tuple.Len() + var hash uint32 = 9137 + 2*uint32(n) + for i := 0; i < n; i++ { + hash += 3 * h.Hash(tuple.At(i).Type()) + } + return hash +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/map_test.go b/vendor/golang.org/x/tools/go/types/typeutil/map_test.go new file mode 100644 index 0000000..34facbe --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/map_test.go @@ -0,0 +1,174 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil_test + +// TODO(adonovan): +// - test use of explicit hasher across two maps. +// - test hashcodes are consistent with equals for a range of types +// (e.g. all types generated by type-checking some body of real code). + +import ( + "go/types" + "testing" + + "golang.org/x/tools/go/types/typeutil" +) + +var ( + tStr = types.Typ[types.String] // string + tPStr1 = types.NewPointer(tStr) // *string + tPStr2 = types.NewPointer(tStr) // *string, again + tInt = types.Typ[types.Int] // int + tChanInt1 = types.NewChan(types.RecvOnly, tInt) // <-chan int + tChanInt2 = types.NewChan(types.RecvOnly, tInt) // <-chan int, again +) + +func checkEqualButNotIdentical(t *testing.T, x, y types.Type, comment string) { + if !types.Identical(x, y) { + t.Errorf("%s: not equal: %s, %s", comment, x, y) + } + if x == y { + t.Errorf("%s: identical: %v, %v", comment, x, y) + } +} + +func TestAxioms(t *testing.T) { + checkEqualButNotIdentical(t, tPStr1, tPStr2, "tPstr{1,2}") + checkEqualButNotIdentical(t, tChanInt1, tChanInt2, "tChanInt{1,2}") +} + +func TestMap(t *testing.T) { + var tmap *typeutil.Map + + // All methods but Set are safe on on (*T)(nil). + tmap.Len() + tmap.At(tPStr1) + tmap.Delete(tPStr1) + tmap.KeysString() + tmap.String() + + tmap = new(typeutil.Map) + + // Length of empty map. + if l := tmap.Len(); l != 0 { + t.Errorf("Len() on empty Map: got %d, want 0", l) + } + // At of missing key. + if v := tmap.At(tPStr1); v != nil { + t.Errorf("At() on empty Map: got %v, want nil", v) + } + // Deletion of missing key. + if tmap.Delete(tPStr1) { + t.Errorf("Delete() on empty Map: got true, want false") + } + // Set of new key. + if prev := tmap.Set(tPStr1, "*string"); prev != nil { + t.Errorf("Set() on empty Map returned non-nil previous value %s", prev) + } + + // Now: {*string: "*string"} + + // Length of non-empty map. + if l := tmap.Len(); l != 1 { + t.Errorf("Len(): got %d, want 1", l) + } + // At via insertion key. + if v := tmap.At(tPStr1); v != "*string" { + t.Errorf("At(): got %q, want \"*string\"", v) + } + // At via equal key. + if v := tmap.At(tPStr2); v != "*string" { + t.Errorf("At(): got %q, want \"*string\"", v) + } + // Iteration over sole entry. + tmap.Iterate(func(key types.Type, value interface{}) { + if key != tPStr1 { + t.Errorf("Iterate: key: got %s, want %s", key, tPStr1) + } + if want := "*string"; value != want { + t.Errorf("Iterate: value: got %s, want %s", value, want) + } + }) + + // Setion with key equal to present one. + if prev := tmap.Set(tPStr2, "*string again"); prev != "*string" { + t.Errorf("Set() previous value: got %s, want \"*string\"", prev) + } + + // Setion of another association. + if prev := tmap.Set(tChanInt1, "<-chan int"); prev != nil { + t.Errorf("Set() previous value: got %s, want nil", prev) + } + + // Now: {*string: "*string again", <-chan int: "<-chan int"} + + want1 := "{*string: \"*string again\", <-chan int: \"<-chan int\"}" + want2 := "{<-chan int: \"<-chan int\", *string: \"*string again\"}" + if s := tmap.String(); s != want1 && s != want2 { + t.Errorf("String(): got %s, want %s", s, want1) + } + + want1 = "{*string, <-chan int}" + want2 = "{<-chan int, *string}" + if s := tmap.KeysString(); s != want1 && s != want2 { + t.Errorf("KeysString(): got %s, want %s", s, want1) + } + + // Keys(). + I := types.Identical + switch k := tmap.Keys(); { + case I(k[0], tChanInt1) && I(k[1], tPStr1): // ok + case I(k[1], tChanInt1) && I(k[0], tPStr1): // ok + default: + t.Errorf("Keys(): got %v, want %s", k, want2) + } + + if l := tmap.Len(); l != 2 { + t.Errorf("Len(): got %d, want 1", l) + } + // At via original key. + if v := tmap.At(tPStr1); v != "*string again" { + t.Errorf("At(): got %q, want \"*string again\"", v) + } + hamming := 1 + tmap.Iterate(func(key types.Type, value interface{}) { + switch { + case I(key, tChanInt1): + hamming *= 2 // ok + case I(key, tPStr1): + hamming *= 3 // ok + } + }) + if hamming != 6 { + t.Errorf("Iterate: hamming: got %d, want %d", hamming, 6) + } + + if v := tmap.At(tChanInt2); v != "<-chan int" { + t.Errorf("At(): got %q, want \"<-chan int\"", v) + } + // Deletion with key equal to present one. + if !tmap.Delete(tChanInt2) { + t.Errorf("Delete() of existing key: got false, want true") + } + + // Now: {*string: "*string again"} + + if l := tmap.Len(); l != 1 { + t.Errorf("Len(): got %d, want 1", l) + } + // Deletion again. + if !tmap.Delete(tPStr2) { + t.Errorf("Delete() of existing key: got false, want true") + } + + // Now: {} + + if l := tmap.Len(); l != 0 { + t.Errorf("Len(): got %d, want %d", l, 0) + } + if s := tmap.String(); s != "{}" { + t.Errorf("Len(): got %q, want %q", s, "") + } +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go b/vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go new file mode 100644 index 0000000..3208461 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go @@ -0,0 +1,72 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements a cache of method sets. + +package typeutil + +import ( + "go/types" + "sync" +) + +// A MethodSetCache records the method set of each type T for which +// MethodSet(T) is called so that repeat queries are fast. +// The zero value is a ready-to-use cache instance. +type MethodSetCache struct { + mu sync.Mutex + named map[*types.Named]struct{ value, pointer *types.MethodSet } // method sets for named N and *N + others map[types.Type]*types.MethodSet // all other types +} + +// MethodSet returns the method set of type T. It is thread-safe. +// +// If cache is nil, this function is equivalent to types.NewMethodSet(T). +// Utility functions can thus expose an optional *MethodSetCache +// parameter to clients that care about performance. +// +func (cache *MethodSetCache) MethodSet(T types.Type) *types.MethodSet { + if cache == nil { + return types.NewMethodSet(T) + } + cache.mu.Lock() + defer cache.mu.Unlock() + + switch T := T.(type) { + case *types.Named: + return cache.lookupNamed(T).value + + case *types.Pointer: + if N, ok := T.Elem().(*types.Named); ok { + return cache.lookupNamed(N).pointer + } + } + + // all other types + // (The map uses pointer equivalence, not type identity.) + mset := cache.others[T] + if mset == nil { + mset = types.NewMethodSet(T) + if cache.others == nil { + cache.others = make(map[types.Type]*types.MethodSet) + } + cache.others[T] = mset + } + return mset +} + +func (cache *MethodSetCache) lookupNamed(named *types.Named) struct{ value, pointer *types.MethodSet } { + if cache.named == nil { + cache.named = make(map[*types.Named]struct{ value, pointer *types.MethodSet }) + } + // Avoid recomputing mset(*T) for each distinct Pointer + // instance whose underlying type is a named type. + msets, ok := cache.named[named] + if !ok { + msets.value = types.NewMethodSet(named) + msets.pointer = types.NewMethodSet(types.NewPointer(named)) + cache.named[named] = msets + } + return msets +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/ui.go b/vendor/golang.org/x/tools/go/types/typeutil/ui.go new file mode 100644 index 0000000..9849c24 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/ui.go @@ -0,0 +1,52 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil + +// This file defines utilities for user interfaces that display types. + +import "go/types" + +// IntuitiveMethodSet returns the intuitive method set of a type T, +// which is the set of methods you can call on an addressable value of +// that type. +// +// The result always contains MethodSet(T), and is exactly MethodSet(T) +// for interface types and for pointer-to-concrete types. +// For all other concrete types T, the result additionally +// contains each method belonging to *T if there is no identically +// named method on T itself. +// +// This corresponds to user intuition about method sets; +// this function is intended only for user interfaces. +// +// The order of the result is as for types.MethodSet(T). +// +func IntuitiveMethodSet(T types.Type, msets *MethodSetCache) []*types.Selection { + isPointerToConcrete := func(T types.Type) bool { + ptr, ok := T.(*types.Pointer) + return ok && !types.IsInterface(ptr.Elem()) + } + + var result []*types.Selection + mset := msets.MethodSet(T) + if types.IsInterface(T) || isPointerToConcrete(T) { + for i, n := 0, mset.Len(); i < n; i++ { + result = append(result, mset.At(i)) + } + } else { + // T is some other concrete type. + // Report methods of T and *T, preferring those of T. + pmset := msets.MethodSet(types.NewPointer(T)) + for i, n := 0, pmset.Len(); i < n; i++ { + meth := pmset.At(i) + if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil { + meth = m + } + result = append(result, meth) + } + + } + return result +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/ui_test.go b/vendor/golang.org/x/tools/go/types/typeutil/ui_test.go new file mode 100644 index 0000000..b5064ac --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/ui_test.go @@ -0,0 +1,61 @@ +package typeutil_test + +import ( + "fmt" + "go/ast" + "go/parser" + "go/token" + "go/types" + "strings" + "testing" + + "golang.org/x/tools/go/types/typeutil" +) + +func TestIntuitiveMethodSet(t *testing.T) { + const source = ` +package P +type A int +func (A) f() +func (*A) g() +` + + fset := token.NewFileSet() + f, err := parser.ParseFile(fset, "hello.go", source, 0) + if err != nil { + t.Fatal(err) + } + + var conf types.Config + pkg, err := conf.Check("P", fset, []*ast.File{f}, nil) + if err != nil { + t.Fatal(err) + } + qual := types.RelativeTo(pkg) + + for _, test := range []struct { + expr string // type expression + want string // intuitive method set + }{ + {"A", "(A).f (*A).g"}, + {"*A", "(*A).f (*A).g"}, + {"error", "(error).Error"}, + {"*error", ""}, + {"struct{A}", "(struct{A}).f (*struct{A}).g"}, + {"*struct{A}", "(*struct{A}).f (*struct{A}).g"}, + } { + tv, err := types.Eval(fset, pkg, 0, test.expr) + if err != nil { + t.Errorf("Eval(%s) failed: %v", test.expr, err) + } + var names []string + for _, m := range typeutil.IntuitiveMethodSet(tv.Type, nil) { + name := fmt.Sprintf("(%s).%s", types.TypeString(m.Recv(), qual), m.Obj().Name()) + names = append(names, name) + } + got := strings.Join(names, " ") + if got != test.want { + t.Errorf("IntuitiveMethodSet(%s) = %q, want %q", test.expr, got, test.want) + } + } +} |