1 files changed, 198 insertions, 0 deletions
diff --git a/src/cmd/gotype/gotype.go b/src/cmd/gotype/gotype.go
new file mode 100644
index 000000000..568467322
--- /dev/null
+++ b/src/cmd/gotype/gotype.go
@@ -0,0 +1,198 @@
+// 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 main
+
+import (
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/scanner"
+	"go/token"
+	"go/types"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+
+var (
+	// main operation modes
+	pkgName   = flag.String("p", "", "process only those files in package pkgName")
+	recursive = flag.Bool("r", false, "recursively process subdirectories")
+	verbose   = flag.Bool("v", false, "verbose mode")
+
+	// debugging support
+	printTrace = flag.Bool("trace", false, "print parse trace")
+	printAST   = flag.Bool("ast", false, "print AST")
+)
+
+
+var exitCode = 0
+
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: gotype [flags] [path ...]\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+
+func report(err os.Error) {
+	scanner.PrintError(os.Stderr, err)
+	exitCode = 2
+}
+
+
+// parse returns the AST for the Go source src.
+// The filename is for error reporting only.
+// The result is nil if there were errors or if
+// the file does not belong to the -p package.
+func parse(fset *token.FileSet, filename string, src []byte) *ast.File {
+	if *verbose {
+		fmt.Println(filename)
+	}
+
+	// ignore files with different package name
+	if *pkgName != "" {
+		file, err := parser.ParseFile(fset, filename, src, parser.PackageClauseOnly)
+		if err != nil {
+			report(err)
+			return nil
+		}
+		if file.Name.Name != *pkgName {
+			if *verbose {
+				fmt.Printf("\tignored (package %s)\n", file.Name.Name)
+			}
+			return nil
+		}
+	}
+
+	// parse entire file
+	mode := parser.DeclarationErrors
+	if *printTrace {
+		mode |= parser.Trace
+	}
+	file, err := parser.ParseFile(fset, filename, src, mode)
+	if err != nil {
+		report(err)
+		return nil
+	}
+	if *printAST {
+		ast.Print(fset, file)
+	}
+
+	return file
+}
+
+
+func parseStdin(fset *token.FileSet) (files map[string]*ast.File) {
+	files = make(map[string]*ast.File)
+	src, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		report(err)
+		return
+	}
+	const filename = "<standard input>"
+	if file := parse(fset, filename, src); file != nil {
+		files[filename] = file
+	}
+	return
+}
+
+
+func parseFiles(fset *token.FileSet, filenames []string) (files map[string]*ast.File) {
+	files = make(map[string]*ast.File)
+	for _, filename := range filenames {
+		src, err := ioutil.ReadFile(filename)
+		if err != nil {
+			report(err)
+			continue
+		}
+		if file := parse(fset, filename, src); file != nil {
+			if files[filename] != nil {
+				report(os.ErrorString(fmt.Sprintf("%q: duplicate file", filename)))
+				continue
+			}
+			files[filename] = file
+		}
+	}
+	return
+}
+
+
+func isGoFilename(filename string) bool {
+	// ignore non-Go files
+	return !strings.HasPrefix(filename, ".") && strings.HasSuffix(filename, ".go")
+}
+
+
+func processDirectory(dirname string) {
+	f, err := os.Open(dirname)
+	if err != nil {
+		report(err)
+		return
+	}
+	filenames, err := f.Readdirnames(-1)
+	f.Close()
+	if err != nil {
+		report(err)
+		// continue since filenames may not be empty
+	}
+	for i, filename := range filenames {
+		filenames[i] = filepath.Join(dirname, filename)
+	}
+	processFiles(filenames, false)
+}
+
+
+func processFiles(filenames []string, allFiles bool) {
+	i := 0
+	for _, filename := range filenames {
+		switch info, err := os.Stat(filename); {
+		case err != nil:
+			report(err)
+		case info.IsRegular():
+			if allFiles || isGoFilename(info.Name) {
+				filenames[i] = filename
+				i++
+			}
+		case info.IsDirectory():
+			if allFiles || *recursive {
+				processDirectory(filename)
+			}
+		}
+	}
+	fset := token.NewFileSet()
+	processPackage(fset, parseFiles(fset, filenames[0:i]))
+}
+
+
+func processPackage(fset *token.FileSet, files map[string]*ast.File) {
+	// make a package (resolve all identifiers)
+	pkg, err := ast.NewPackage(fset, files, types.GcImporter, types.Universe)
+	if err != nil {
+		report(err)
+		return
+	}
+	// TODO(gri): typecheck package
+	_ = pkg
+}
+
+
+func main() {
+	flag.Usage = usage
+	flag.Parse()
+
+	if flag.NArg() == 0 {
+		fset := token.NewFileSet()
+		processPackage(fset, parseStdin(fset))
+	} else {
+		processFiles(flag.Args(), true)
+	}
+
+	os.Exit(exitCode)
+}