Golang Context.ReadDir方法代码示例

// Setup configures a *build.Context to use the given VFS
// as its filesystem.
func Setup(ctx *build.Context, fs vfs.VFS) {
	ctx.JoinPath = path.Join
	ctx.SplitPathList = filepath.SplitList
	ctx.IsAbsPath = func(p string) bool {
		return p != "" && p[0] == '/'
	}
	ctx.IsDir = func(p string) bool {
		stat, err := fs.Stat(p)
		return err == nil && stat.IsDir()
	}
	ctx.HasSubdir = func(root, dir string) (string, bool) {
		root = path.Clean(root)
		if !strings.HasSuffix(root, separator) {
			root += separator
		}
		dir = path.Clean(dir)
		if !strings.HasPrefix(dir, root) {
			return "", false
		}
		return dir[len(root):], true
	}
	ctx.ReadDir = fs.ReadDir
	ctx.OpenFile = func(p string) (io.ReadCloser, error) {
		return fs.Open(p)
	}
}

func (w *Walker) setMemoryContext(ctxt *build.Context) {
	ctxt.JoinPath = path.Join
	ctxt.IsAbsPath = path.IsAbs
	ctxt.IsDir = func(path string) bool { panic("unexpected") }
	ctxt.HasSubdir = func(root, dir string) (rel string, ok bool) { panic("unexpected") }
	ctxt.ReadDir = func(dir string) (fi []os.FileInfo, err error) { return w.readDir(dir) }
	ctxt.OpenFile = func(path string) (r io.ReadCloser, err error) { return w.openFile(path) }
}

// Import returns details about the package in the directory.
func (dir *Directory) Import(ctx *build.Context, mode build.ImportMode) (*build.Package, error) {
	safeCopy := *ctx
	ctx = &safeCopy
	ctx.JoinPath = path.Join
	ctx.IsAbsPath = path.IsAbs
	ctx.SplitPathList = func(list string) []string { return strings.Split(list, ":") }
	ctx.IsDir = func(path string) bool { return false }
	ctx.HasSubdir = func(root, dir string) (rel string, ok bool) { return "", false }
	ctx.ReadDir = dir.readDir
	ctx.OpenFile = dir.openFile
	return ctx.ImportDir(".", mode)
}

// 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)
}

func getPackage(pkgpath string) (*gobuild.Package, error) {
	var ctx gobuild.Context = gobuild.Default
	ctx.GOARCH = GOARCH
	ctx.GOOS = GOOS
	ctx.BuildTags = append(ctx.BuildTags[:], "llgo")
	//ctx.Compiler = "llgo"

	// Attempt to find an overlay package path,
	// which we'll use in ReadDir below.
	overlayentries := make(map[string]bool)
	overlaypkgpath := llgoPkgPrefix + pkgpath
	overlaypkg, err := ctx.Import(overlaypkgpath, "", gobuild.FindOnly)
	if err != nil {
		overlaypkg = nil
	}

	// ReadDir is overridden to return a fake ".s"
	// file for each ".ll" file in the directory.
	ctx.ReadDir = func(dir string) (fi []os.FileInfo, err error) {
		fi, err = ioutil.ReadDir(dir)
		if err != nil {
			return nil, err
		}
		entries := make(map[string]os.FileInfo)
		for _, info := range fi {
			entries[info.Name()] = info
		}
		// Overlay all files in the overlay package dir.
		// If we find any .ll files, replace the suffix
		// with .s.
		if overlaypkg != nil {
			fi, err = ioutil.ReadDir(overlaypkg.Dir)
		}
		if err == nil {
			// Check for .ll files in the overlay dir if
			// we have one, else in the standard package dir.
			for _, info := range fi {
				name := info.Name()
				if strings.HasSuffix(name, ".ll") {
					name = name[:len(name)-3] + ".s"
					info = &renamedFileInfo{info, name}
				}
				overlayentries[name] = true
				entries[name] = info
			}
		}
		fi = make([]os.FileInfo, 0, len(entries))
		for _, info := range entries {
			fi = append(fi, info)
		}
		return fi, nil
	}

	// OpenFile is overridden to return the contents
	// of the ".ll" file found in ReadDir above. The
	// returned ReadCloser is wrapped to transform
	// LLVM IR comments to use "//", as expected by
	// go/build when looking for build tags.
	ctx.OpenFile = func(path string) (io.ReadCloser, error) {
		base := filepath.Base(path)
		overlay := overlayentries[base]
		if overlay {
			if overlaypkg != nil {
				path = filepath.Join(overlaypkg.Dir, base)
			}
			if strings.HasSuffix(path, ".s") {
				path := path[:len(path)-2] + ".ll"
				var r io.ReadCloser
				var err error
				r, err = os.Open(path)
				if err == nil {
					r = build.NewLLVMIRReader(r)
				}
				return r, err
			}
		}
		return os.Open(path)
	}

	pkg, err := ctx.Import(pkgpath, "", 0)
	if err != nil {
		return nil, err
	} else {
		if overlaypkg == nil {
			overlaypkg = pkg
		}
		for i, filename := range pkg.GoFiles {
			pkgdir := pkg.Dir
			if overlayentries[filename] {
				pkgdir = overlaypkg.Dir
			}
			pkg.GoFiles[i] = path.Join(pkgdir, filename)
		}
		for i, filename := range pkg.CFiles {
			pkgdir := pkg.Dir
			if overlayentries[filename] {
				pkgdir = overlaypkg.Dir
			}
			pkg.CFiles[i] = path.Join(pkgdir, filename)
		}
//.........这里部分代码省略.........