blob: f54a5e0d963bf76b14efaf97026ce31d05883733 [file] [log] [blame]
// 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 (
"bytes"
"flag"
"fmt"
"go/ast"
"go/format"
"go/parser"
"go/scanner"
"go/token"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"runtime"
"sort"
"strings"
)
var (
fset = token.NewFileSet()
exitCode = 0
)
var allowedRewrites = flag.String("r", "",
"restrict the rewrites to this comma-separated list")
var forceRewrites = flag.String("force", "",
"force these fixes to run even if the code looks updated")
var allowed, force map[string]bool
var doDiff = flag.Bool("diff", false, "display diffs instead of rewriting files")
// enable for debugging fix failures
const debug = false // display incorrectly reformatted source and exit
func usage() {
fmt.Fprintf(os.Stderr, "usage: go tool fix [-diff] [-r fixname,...] [-force fixname,...] [path ...]\n")
flag.PrintDefaults()
fmt.Fprintf(os.Stderr, "\nAvailable rewrites are:\n")
sort.Sort(byName(fixes))
for _, f := range fixes {
if f.disabled {
fmt.Fprintf(os.Stderr, "\n%s (disabled)\n", f.name)
} else {
fmt.Fprintf(os.Stderr, "\n%s\n", f.name)
}
desc := strings.TrimSpace(f.desc)
desc = strings.ReplaceAll(desc, "\n", "\n\t")
fmt.Fprintf(os.Stderr, "\t%s\n", desc)
}
os.Exit(2)
}
func main() {
flag.Usage = usage
flag.Parse()
sort.Sort(byDate(fixes))
if *allowedRewrites != "" {
allowed = make(map[string]bool)
for _, f := range strings.Split(*allowedRewrites, ",") {
allowed[f] = true
}
}
if *forceRewrites != "" {
force = make(map[string]bool)
for _, f := range strings.Split(*forceRewrites, ",") {
force[f] = true
}
}
if flag.NArg() == 0 {
if err := processFile("standard input", true); err != nil {
report(err)
}
os.Exit(exitCode)
}
for i := 0; i < flag.NArg(); i++ {
path := flag.Arg(i)
switch dir, err := os.Stat(path); {
case err != nil:
report(err)
case dir.IsDir():
walkDir(path)
default:
if err := processFile(path, false); err != nil {
report(err)
}
}
}
os.Exit(exitCode)
}
const parserMode = parser.ParseComments
func gofmtFile(f *ast.File) ([]byte, error) {
var buf bytes.Buffer
if err := format.Node(&buf, fset, f); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
func processFile(filename string, useStdin bool) error {
var f *os.File
var err error
var fixlog bytes.Buffer
if useStdin {
f = os.Stdin
} else {
f, err = os.Open(filename)
if err != nil {
return err
}
defer f.Close()
}
src, err := ioutil.ReadAll(f)
if err != nil {
return err
}
file, err := parser.ParseFile(fset, filename, src, parserMode)
if err != nil {
return err
}
// Apply all fixes to file.
newFile := file
fixed := false
for _, fix := range fixes {
if allowed != nil && !allowed[fix.name] {
continue
}
if fix.disabled && !force[fix.name] {
continue
}
if fix.f(newFile) {
fixed = true
fmt.Fprintf(&fixlog, " %s", fix.name)
// AST changed.
// Print and parse, to update any missing scoping
// or position information for subsequent fixers.
newSrc, err := gofmtFile(newFile)
if err != nil {
return err
}
newFile, err = parser.ParseFile(fset, filename, newSrc, parserMode)
if err != nil {
if debug {
fmt.Printf("%s", newSrc)
report(err)
os.Exit(exitCode)
}
return err
}
}
}
if !fixed {
return nil
}
fmt.Fprintf(os.Stderr, "%s: fixed %s\n", filename, fixlog.String()[1:])
// Print AST. We did that after each fix, so this appears
// redundant, but it is necessary to generate gofmt-compatible
// source code in a few cases. The official gofmt style is the
// output of the printer run on a standard AST generated by the parser,
// but the source we generated inside the loop above is the
// output of the printer run on a mangled AST generated by a fixer.
newSrc, err := gofmtFile(newFile)
if err != nil {
return err
}
if *doDiff {
data, err := diff(src, newSrc)
if err != nil {
return fmt.Errorf("computing diff: %s", err)
}
fmt.Printf("diff %s fixed/%s\n", filename, filename)
os.Stdout.Write(data)
return nil
}
if useStdin {
os.Stdout.Write(newSrc)
return nil
}
return ioutil.WriteFile(f.Name(), newSrc, 0)
}
var gofmtBuf bytes.Buffer
func gofmt(n interface{}) string {
gofmtBuf.Reset()
if err := format.Node(&gofmtBuf, fset, n); err != nil {
return "<" + err.Error() + ">"
}
return gofmtBuf.String()
}
func report(err error) {
scanner.PrintError(os.Stderr, err)
exitCode = 2
}
func walkDir(path string) {
filepath.Walk(path, visitFile)
}
func visitFile(path string, f os.FileInfo, err error) error {
if err == nil && isGoFile(f) {
err = processFile(path, false)
}
if err != nil {
report(err)
}
return nil
}
func isGoFile(f os.FileInfo) bool {
// ignore non-Go files
name := f.Name()
return !f.IsDir() && !strings.HasPrefix(name, ".") && strings.HasSuffix(name, ".go")
}
func writeTempFile(dir, prefix string, data []byte) (string, error) {
file, err := ioutil.TempFile(dir, prefix)
if err != nil {
return "", err
}
_, err = file.Write(data)
if err1 := file.Close(); err == nil {
err = err1
}
if err != nil {
os.Remove(file.Name())
return "", err
}
return file.Name(), nil
}
func diff(b1, b2 []byte) (data []byte, err error) {
f1, err := writeTempFile("", "go-fix", b1)
if err != nil {
return
}
defer os.Remove(f1)
f2, err := writeTempFile("", "go-fix", b2)
if err != nil {
return
}
defer os.Remove(f2)
cmd := "diff"
if runtime.GOOS == "plan9" {
cmd = "/bin/ape/diff"
}
data, err = exec.Command(cmd, "-u", f1, f2).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
}