diff options
Diffstat (limited to 'vendor/golang.org/x/tools/go/loader/cgo.go')
| -rw-r--r-- | vendor/golang.org/x/tools/go/loader/cgo.go | 207 |
1 files changed, 0 insertions, 207 deletions
diff --git a/vendor/golang.org/x/tools/go/loader/cgo.go b/vendor/golang.org/x/tools/go/loader/cgo.go deleted file mode 100644 index 72c6f50..0000000 --- a/vendor/golang.org/x/tools/go/loader/cgo.go +++ /dev/null @@ -1,207 +0,0 @@ -// 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 -} |