diff options
Diffstat (limited to 'vendor/golang.org/x/tools/go/buildutil/util.go')
-rw-r--r-- | vendor/golang.org/x/tools/go/buildutil/util.go | 212 |
1 files changed, 212 insertions, 0 deletions
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 00000000..fc923d7a --- /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 +} |