blob: abd30edc89b6c9f6635813e43e2beebcb599395f [file] [log] [blame]
// 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"
"flag"
"fmt"
"go/ast"
"go/parser"
"go/printer"
"go/scanner"
"io/ioutil"
"os"
pathutil "path"
"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:]')")
// debugging support
comments = flag.Bool("comments", true, "print comments")
debug = flag.Bool("debug", false, "print debugging information")
trace = flag.Bool("trace", false, "print parse trace")
// layout control
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")
)
var (
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 *trace {
parserMode |= parser.Trace
}
}
func initPrinterMode() {
printerMode = uint(0)
if *tabIndent {
printerMode |= printer.TabIndent
}
if *useSpaces {
printerMode |= printer.UseSpaces
}
}
func isGoFile(d *os.Dir) bool {
// ignore non-Go files
return d.IsRegular() && !strings.HasPrefix(d.Name, ".") && strings.HasSuffix(d.Name, ".go")
}
func processFile(f *os.File) os.Error {
src, err := ioutil.ReadAll(f)
if err != nil {
return err
}
var scope *ast.Scope
if *debug {
scope = ast.NewScope(nil)
}
file, err := parser.ParseFile(f.Name(), src, scope, parserMode)
if err != nil {
return err
}
if rewrite != nil {
file = rewrite(file)
}
var res bytes.Buffer
_, err = (&printer.Config{printerMode, *tabWidth, nil}).Fprint(&res, file)
if err != nil {
return err
}
if bytes.Compare(src, res.Bytes()) != 0 {
// formatting has changed
if *list {
fmt.Fprintln(os.Stdout, f.Name())
}
if *write {
err = ioutil.WriteFile(f.Name(), res.Bytes(), 0)
if err != nil {
return err
}
}
}
if !*list && !*write {
_, err = os.Stdout.Write(res.Bytes())
}
return err
}
func processFileByName(filename string) (err os.Error) {
file, err := os.Open(filename, os.O_RDONLY, 0)
if err != nil {
return
}
defer file.Close()
return processFile(file)
}
type fileVisitor chan os.Error
func (v fileVisitor) VisitDir(path string, d *os.Dir) bool {
return true
}
func (v fileVisitor) VisitFile(path string, d *os.Dir) {
if isGoFile(d) {
v <- nil // synchronize error handler
if err := processFileByName(path); err != nil {
v <- err
}
}
}
func walkDir(path string) {
// start an error handler
done := make(chan bool)
v := make(fileVisitor)
go func() {
for err := range v {
if err != nil {
report(err)
}
}
done <- true
}()
// walk the tree
pathutil.Walk(path, v, v)
close(v) // terminate error handler loop
<-done // wait for all errors to be reported
}
func main() {
flag.Usage = usage
flag.Parse()
if *tabWidth < 0 {
fmt.Fprintf(os.Stderr, "negative tabwidth %d\n", *tabWidth)
os.Exit(2)
}
initParserMode()
initPrinterMode()
initRewrite()
if flag.NArg() == 0 {
if err := processFile(os.Stdin); err != nil {
report(err)
}
}
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 := processFileByName(path); err != nil {
report(err)
}
case dir.IsDirectory():
walkDir(path)
}
}
os.Exit(exitCode)
}