1 files changed, 173 insertions, 0 deletions
diff --git a/src/pkg/go/build/dir.go b/src/pkg/go/build/dir.go
new file mode 100644
index 000000000..77e80bff0
--- /dev/null
+++ b/src/pkg/go/build/dir.go
@@ -0,0 +1,173 @@
+// Copyright 2011 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 build
+
+import (
+	"go/parser"
+	"go/token"
+	"log"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"runtime"
+)
+
+type DirInfo struct {
+	GoFiles  []string // .go files in dir (excluding CgoFiles)
+	CgoFiles []string // .go files that import "C"
+	CFiles   []string // .c files in dir
+	SFiles   []string // .s files in dir
+	Imports  []string // All packages imported by goFiles
+	PkgName  string   // Name of package in dir
+}
+
+func (d *DirInfo) IsCommand() bool {
+	return d.PkgName == "main"
+}
+
+// ScanDir returns a structure with details about the Go content found
+// in the given directory. The file lists exclude:
+//
+//	- files in package main (unless allowMain is true)
+//	- files in package documentation
+//	- files ending in _test.go
+// 	- files starting with _ or .
+//
+// Only files that satisfy the goodOSArch function are included.
+func ScanDir(dir string, allowMain bool) (info *DirInfo, err os.Error) {
+	f, err := os.Open(dir)
+	if err != nil {
+		return nil, err
+	}
+	dirs, err := f.Readdir(-1)
+	f.Close()
+	if err != nil {
+		return nil, err
+	}
+
+	var di DirInfo
+	imported := make(map[string]bool)
+	pkgName := ""
+	fset := token.NewFileSet()
+	for i := range dirs {
+		d := &dirs[i]
+		if strings.HasPrefix(d.Name, "_") ||
+			strings.HasPrefix(d.Name, ".") {
+			continue
+		}
+		if !goodOSArch(d.Name) {
+			continue
+		}
+
+		switch filepath.Ext(d.Name) {
+		case ".go":
+			if strings.HasSuffix(d.Name, "_test.go") {
+				continue
+			}
+		case ".c":
+			di.CFiles = append(di.CFiles, d.Name)
+			continue
+		case ".s":
+			di.SFiles = append(di.SFiles, d.Name)
+			continue
+		default:
+			continue
+		}
+
+		filename := filepath.Join(dir, d.Name)
+		pf, err := parser.ParseFile(fset, filename, nil, parser.ImportsOnly)
+		if err != nil {
+			return nil, err
+		}
+		s := string(pf.Name.Name)
+		if s == "main" && !allowMain {
+			continue
+		}
+		if s == "documentation" {
+			continue
+		}
+		if pkgName == "" {
+			pkgName = s
+		} else if pkgName != s {
+			// Only if all files in the directory are in package main
+			// do we return pkgName=="main".
+			// A mix of main and another package reverts
+			// to the original (allowMain=false) behaviour.
+			if s == "main" || pkgName == "main" {
+				return ScanDir(dir, false)
+			}
+			return nil, os.ErrorString("multiple package names in " + dir)
+		}
+		isCgo := false
+		for _, spec := range pf.Imports {
+			quoted := string(spec.Path.Value)
+			path, err := strconv.Unquote(quoted)
+			if err != nil {
+				log.Panicf("%s: parser returned invalid quoted string: <%s>", filename, quoted)
+			}
+			imported[path] = true
+			if path == "C" {
+				isCgo = true
+			}
+		}
+		if isCgo {
+			di.CgoFiles = append(di.CgoFiles, d.Name)
+		} else {
+			di.GoFiles = append(di.GoFiles, d.Name)
+		}
+	}
+	di.Imports = make([]string, len(imported))
+	i := 0
+	for p := range imported {
+		di.Imports[i] = p
+		i++
+	}
+	return &di, nil
+}
+
+// goodOSArch returns false if the filename contains a $GOOS or $GOARCH
+// suffix which does not match the current system.
+// The recognized filename formats are:
+//
+//     name_$(GOOS).*
+//     name_$(GOARCH).*
+//     name_$(GOOS)_$(GOARCH).*
+//
+func goodOSArch(filename string) bool {
+	if dot := strings.Index(filename, "."); dot != -1 {
+		filename = filename[:dot]
+	}
+	l := strings.Split(filename, "_", -1)
+	n := len(l)
+	if n == 0 {
+		return true
+	}
+	if good, known := goodOS[l[n-1]]; known {
+		return good
+	}
+	if good, known := goodArch[l[n-1]]; known {
+		if !good || n < 2 {
+			return false
+		}
+		good, known = goodOS[l[n-2]]
+		return good || !known
+	}
+	return true
+}
+
+var goodOS = make(map[string]bool)
+var goodArch = make(map[string]bool)
+
+func init() {
+	goodOS = make(map[string]bool)
+	goodArch = make(map[string]bool)
+	for _, v := range strings.Fields(goosList) {
+		goodOS[v] = v == runtime.GOOS
+	}
+	for _, v := range strings.Fields(goarchList) {
+		goodArch[v] = v == runtime.GOARCH
+	}
+}