From b1247d2d0d51108c910a73891ff3116e5f032ab1 Mon Sep 17 00:00:00 2001 From: "Kali Kaneko (leap communications)" Date: Sat, 12 Jan 2019 18:39:45 +0100 Subject: [pkg] all your deps are vendored to us --- .../golang.org/x/tools/go/ast/astutil/rewrite.go | 477 +++++++++++++++++++++ 1 file changed, 477 insertions(+) create mode 100644 vendor/golang.org/x/tools/go/ast/astutil/rewrite.go (limited to 'vendor/golang.org/x/tools/go/ast/astutil/rewrite.go') 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 +} -- cgit v1.2.3