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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
commit73df946d56c74384511a194dd01dbe099584fd1a (patch)
treefd0bcea490dd81327ddfbb31e215439672c9a068 /src/cmd/gofmt/gofmt.go
parentInitial commit. (diff)
downloadgolang-1.16-upstream.tar.xz
golang-1.16-upstream.zip
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/cmd/gofmt/gofmt.go')
-rw-r--r--src/cmd/gofmt/gofmt.go301
1 files changed, 301 insertions, 0 deletions
diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
new file mode 100644
index 0000000..2793c2c
--- /dev/null
+++ b/src/cmd/gofmt/gofmt.go
@@ -0,0 +1,301 @@
+// 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"
+ "go/token"
+ "io"
+ "io/fs"
+ "os"
+ "path/filepath"
+ "runtime"
+ "runtime/pprof"
+ "strings"
+
+ "cmd/internal/diff"
+)
+
+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., 'a[b:len(a)] -> a[b:]')")
+ simplifyAST = flag.Bool("s", false, "simplify code")
+ doDiff = flag.Bool("d", false, "display diffs instead of rewriting files")
+ allErrors = flag.Bool("e", false, "report all errors (not just the first 10 on different lines)")
+
+ // debugging
+ cpuprofile = flag.String("cpuprofile", "", "write cpu profile to this file")
+)
+
+// Keep these in sync with go/format/format.go.
+const (
+ tabWidth = 8
+ printerMode = printer.UseSpaces | printer.TabIndent | printerNormalizeNumbers
+
+ // printerNormalizeNumbers means to canonicalize number literal prefixes
+ // and exponents while printing. See https://golang.org/doc/go1.13#gofmt.
+ //
+ // This value is defined in go/printer specifically for go/format and cmd/gofmt.
+ printerNormalizeNumbers = 1 << 30
+)
+
+var (
+ fileSet = token.NewFileSet() // per process FileSet
+ exitCode = 0
+ rewrite func(*ast.File) *ast.File
+ parserMode parser.Mode
+)
+
+func report(err error) {
+ scanner.PrintError(os.Stderr, err)
+ exitCode = 2
+}
+
+func usage() {
+ fmt.Fprintf(os.Stderr, "usage: gofmt [flags] [path ...]\n")
+ flag.PrintDefaults()
+}
+
+func initParserMode() {
+ parserMode = parser.ParseComments
+ if *allErrors {
+ parserMode |= parser.AllErrors
+ }
+}
+
+func isGoFile(f fs.DirEntry) bool {
+ // ignore non-Go files
+ name := f.Name()
+ return !f.IsDir() && !strings.HasPrefix(name, ".") && strings.HasSuffix(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, stdin bool) error {
+ var perm fs.FileMode = 0644
+ if in == nil {
+ f, err := os.Open(filename)
+ if err != nil {
+ return err
+ }
+ defer f.Close()
+ fi, err := f.Stat()
+ if err != nil {
+ return err
+ }
+ in = f
+ perm = fi.Mode().Perm()
+ }
+
+ src, err := io.ReadAll(in)
+ if err != nil {
+ return err
+ }
+
+ file, sourceAdj, indentAdj, err := parse(fileSet, filename, src, stdin)
+ if err != nil {
+ return err
+ }
+
+ if rewrite != nil {
+ if sourceAdj == nil {
+ file = rewrite(file)
+ } else {
+ fmt.Fprintf(os.Stderr, "warning: rewrite ignored for incomplete programs\n")
+ }
+ }
+
+ ast.SortImports(fileSet, file)
+
+ if *simplifyAST {
+ simplify(file)
+ }
+
+ res, err := format(fileSet, file, sourceAdj, indentAdj, src, printer.Config{Mode: printerMode, Tabwidth: tabWidth})
+ if err != nil {
+ return err
+ }
+
+ if !bytes.Equal(src, res) {
+ // formatting has changed
+ if *list {
+ fmt.Fprintln(out, filename)
+ }
+ if *write {
+ // make a temporary backup before overwriting original
+ bakname, err := backupFile(filename+".", src, perm)
+ if err != nil {
+ return err
+ }
+ err = os.WriteFile(filename, res, perm)
+ if err != nil {
+ os.Rename(bakname, filename)
+ return err
+ }
+ err = os.Remove(bakname)
+ if err != nil {
+ return err
+ }
+ }
+ if *doDiff {
+ data, err := diffWithReplaceTempFile(src, res, filename)
+ if err != nil {
+ return fmt.Errorf("computing diff: %s", err)
+ }
+ fmt.Printf("diff -u %s %s\n", filepath.ToSlash(filename+".orig"), filepath.ToSlash(filename))
+ out.Write(data)
+ }
+ }
+
+ if !*list && !*write && !*doDiff {
+ _, err = out.Write(res)
+ }
+
+ return err
+}
+
+func visitFile(path string, f fs.DirEntry, err error) error {
+ if err == nil && isGoFile(f) {
+ err = processFile(path, nil, os.Stdout, false)
+ }
+ // Don't complain if a file was deleted in the meantime (i.e.
+ // the directory changed concurrently while running gofmt).
+ if err != nil && !os.IsNotExist(err) {
+ report(err)
+ }
+ return nil
+}
+
+func walkDir(path string) {
+ filepath.WalkDir(path, visitFile)
+}
+
+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 *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()
+ initRewrite()
+
+ if flag.NArg() == 0 {
+ if *write {
+ fmt.Fprintln(os.Stderr, "error: cannot use -w with standard input")
+ exitCode = 2
+ return
+ }
+ if err := processFile("<standard input>", os.Stdin, os.Stdout, true); 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.IsDir():
+ walkDir(path)
+ default:
+ if err := processFile(path, nil, os.Stdout, false); err != nil {
+ report(err)
+ }
+ }
+ }
+}
+
+func diffWithReplaceTempFile(b1, b2 []byte, filename string) ([]byte, error) {
+ data, err := diff.Diff("gofmt", b1, b2)
+ if len(data) > 0 {
+ return replaceTempFilename(data, filename)
+ }
+ return data, err
+}
+
+// replaceTempFilename replaces temporary filenames in diff with actual one.
+//
+// --- /tmp/gofmt316145376 2017-02-03 19:13:00.280468375 -0500
+// +++ /tmp/gofmt617882815 2017-02-03 19:13:00.280468375 -0500
+// ...
+// ->
+// --- path/to/file.go.orig 2017-02-03 19:13:00.280468375 -0500
+// +++ path/to/file.go 2017-02-03 19:13:00.280468375 -0500
+// ...
+func replaceTempFilename(diff []byte, filename string) ([]byte, error) {
+ bs := bytes.SplitN(diff, []byte{'\n'}, 3)
+ if len(bs) < 3 {
+ return nil, fmt.Errorf("got unexpected diff for %s", filename)
+ }
+ // Preserve timestamps.
+ var t0, t1 []byte
+ if i := bytes.LastIndexByte(bs[0], '\t'); i != -1 {
+ t0 = bs[0][i:]
+ }
+ if i := bytes.LastIndexByte(bs[1], '\t'); i != -1 {
+ t1 = bs[1][i:]
+ }
+ // Always print filepath with slash separator.
+ f := filepath.ToSlash(filename)
+ bs[0] = []byte(fmt.Sprintf("--- %s%s", f+".orig", t0))
+ bs[1] = []byte(fmt.Sprintf("+++ %s%s", f, t1))
+ return bytes.Join(bs, []byte{'\n'}), nil
+}
+
+const chmodSupported = runtime.GOOS != "windows"
+
+// backupFile writes data to a new file named filename<number> with permissions perm,
+// with <number randomly chosen such that the file name is unique. backupFile returns
+// the chosen file name.
+func backupFile(filename string, data []byte, perm fs.FileMode) (string, error) {
+ // create backup file
+ f, err := os.CreateTemp(filepath.Dir(filename), filepath.Base(filename))
+ if err != nil {
+ return "", err
+ }
+ bakname := f.Name()
+ if chmodSupported {
+ err = f.Chmod(perm)
+ if err != nil {
+ f.Close()
+ os.Remove(bakname)
+ return bakname, err
+ }
+ }
+
+ // write data to backup file
+ _, err = f.Write(data)
+ if err1 := f.Close(); err == nil {
+ err = err1
+ }
+
+ return bakname, err
+}