1 files changed, 261 insertions, 0 deletions
diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
new file mode 100644
index 000000000..975ae6ac6
--- /dev/null
+++ b/src/cmd/gofmt/gofmt.go
@@ -0,0 +1,261 @@
+// Copyright 2009 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 (
+	"bytes"
+	"exec"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/printer"
+	"go/scanner"
+	"go/token"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime/pprof"
+	"strings"
+)
+
+var (
+	// main operation modes
+	list        = flag.Bool("l", false, "list files whose formatting differs from gofmt's")
+	write       = flag.Bool("w", false, "write result to (source) file instead of stdout")
+	rewriteRule = flag.String("r", "", "rewrite rule (e.g., 'α[β:len(α)] -> α[β:]')")
+	simplifyAST = flag.Bool("s", false, "simplify code")
+	doDiff      = flag.Bool("d", false, "display diffs instead of rewriting files")
+	allErrors   = flag.Bool("e", false, "print all (including spurious) errors")
+
+	// layout control
+	comments  = flag.Bool("comments", true, "print comments")
+	tabWidth  = flag.Int("tabwidth", 8, "tab width")
+	tabIndent = flag.Bool("tabindent", true, "indent with tabs independent of -spaces")
+	useSpaces = flag.Bool("spaces", true, "align with spaces instead of tabs")
+
+	// debugging
+	cpuprofile = flag.String("cpuprofile", "", "write cpu profile to this file")
+)
+
+var (
+	fset        = token.NewFileSet()
+	exitCode    = 0
+	rewrite     func(*ast.File) *ast.File
+	parserMode  uint
+	printerMode uint
+)
+
+func report(err os.Error) {
+	scanner.PrintError(os.Stderr, err)
+	exitCode = 2
+}
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: gofmt [flags] [path ...]\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+func initParserMode() {
+	parserMode = uint(0)
+	if *comments {
+		parserMode |= parser.ParseComments
+	}
+	if *allErrors {
+		parserMode |= parser.SpuriousErrors
+	}
+}
+
+func initPrinterMode() {
+	printerMode = uint(0)
+	if *tabIndent {
+		printerMode |= printer.TabIndent
+	}
+	if *useSpaces {
+		printerMode |= printer.UseSpaces
+	}
+}
+
+func isGoFile(f *os.FileInfo) bool {
+	// ignore non-Go files
+	return f.IsRegular() && !strings.HasPrefix(f.Name, ".") && strings.HasSuffix(f.Name, ".go")
+}
+
+// If in == nil, the source is the contents of the file with the given filename.
+func processFile(filename string, in io.Reader, out io.Writer) os.Error {
+	if in == nil {
+		f, err := os.Open(filename)
+		if err != nil {
+			return err
+		}
+		defer f.Close()
+		in = f
+	}
+
+	src, err := ioutil.ReadAll(in)
+	if err != nil {
+		return err
+	}
+
+	file, err := parser.ParseFile(fset, filename, src, parserMode)
+	if err != nil {
+		return err
+	}
+
+	if rewrite != nil {
+		file = rewrite(file)
+	}
+
+	if *simplifyAST {
+		simplify(file)
+	}
+
+	var buf bytes.Buffer
+	_, err = (&printer.Config{printerMode, *tabWidth}).Fprint(&buf, fset, file)
+	if err != nil {
+		return err
+	}
+	res := buf.Bytes()
+
+	if !bytes.Equal(src, res) {
+		// formatting has changed
+		if *list {
+			fmt.Fprintln(out, filename)
+		}
+		if *write {
+			err = ioutil.WriteFile(filename, res, 0)
+			if err != nil {
+				return err
+			}
+		}
+		if *doDiff {
+			data, err := diff(src, res)
+			if err != nil {
+				return fmt.Errorf("computing diff: %s", err)
+			}
+			fmt.Printf("diff %s gofmt/%s\n", filename, filename)
+			out.Write(data)
+		}
+	}
+
+	if !*list && !*write && !*doDiff {
+		_, err = out.Write(res)
+	}
+
+	return err
+}
+
+type fileVisitor chan os.Error
+
+func (v fileVisitor) VisitDir(path string, f *os.FileInfo) bool {
+	return true
+}
+
+func (v fileVisitor) VisitFile(path string, f *os.FileInfo) {
+	if isGoFile(f) {
+		v <- nil // synchronize error handler
+		if err := processFile(path, nil, os.Stdout); err != nil {
+			v <- err
+		}
+	}
+}
+
+func walkDir(path string) {
+	v := make(fileVisitor)
+	go func() {
+		filepath.Walk(path, v, v)
+		close(v)
+	}()
+	for err := range v {
+		if err != nil {
+			report(err)
+		}
+	}
+}
+
+func main() {
+	// call gofmtMain in a separate function
+	// so that it can use defer and have them
+	// run before the exit.
+	gofmtMain()
+	os.Exit(exitCode)
+}
+
+func gofmtMain() {
+	flag.Usage = usage
+	flag.Parse()
+	if *tabWidth < 0 {
+		fmt.Fprintf(os.Stderr, "negative tabwidth %d\n", *tabWidth)
+		exitCode = 2
+		return
+	}
+
+	if *cpuprofile != "" {
+		f, err := os.Create(*cpuprofile)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "creating cpu profile: %s\n", err)
+			exitCode = 2
+			return
+		}
+		defer f.Close()
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+
+	initParserMode()
+	initPrinterMode()
+	initRewrite()
+
+	if flag.NArg() == 0 {
+		if err := processFile("<standard input>", os.Stdin, os.Stdout); err != nil {
+			report(err)
+		}
+		return
+	}
+
+	for i := 0; i < flag.NArg(); i++ {
+		path := flag.Arg(i)
+		switch dir, err := os.Stat(path); {
+		case err != nil:
+			report(err)
+		case dir.IsRegular():
+			if err := processFile(path, nil, os.Stdout); err != nil {
+				report(err)
+			}
+		case dir.IsDirectory():
+			walkDir(path)
+		}
+	}
+}
+
+func diff(b1, b2 []byte) (data []byte, err os.Error) {
+	f1, err := ioutil.TempFile("", "gofmt")
+	if err != nil {
+		return
+	}
+	defer os.Remove(f1.Name())
+	defer f1.Close()
+
+	f2, err := ioutil.TempFile("", "gofmt")
+	if err != nil {
+		return
+	}
+	defer os.Remove(f2.Name())
+	defer f2.Close()
+
+	f1.Write(b1)
+	f2.Write(b2)
+
+	data, err = exec.Command("diff", "-u", f1.Name(), f2.Name()).CombinedOutput()
+	if len(data) > 0 {
+		// diff exits with a non-zero status when the files don't match.
+		// Ignore that failure as long as we get output.
+		err = nil
+	}
+	return
+
+}