From a54762586fd7b91cb1a8b8bb404db87e6b976d59 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Daniel=20Mart=C3=AD?= Date: Fri, 15 Jan 2021 23:10:48 +0000 Subject: [PATCH] cmd/gofmt: simplify arg handling MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit First, we can use flag.Args instead of flag.NArg and flag.Arg. Second, just call filepath.WalkDir directly on each argument. We don't need to check if each argument is a directory or not, since the function will still work on regular files as expected. To continue giving an error in the "gofmt does-not-exist.go" case, we now need to return and handle errors from filepath.WalkDir, too. Arguably, that should have always been the case. While at it, I noticed that the printinf of the "diff" command did not obey the "out" parameter. Fix that. Finally, remove the code to ignore IsNotExist errors. It was added in CL 19301, though it didn't include tests and its reasoning is dubious. Using gofmt on a directory treewhile another program is concurrently editing or removing files is inherently racy. Hiding errors can hide valid problems from the user, and such racy usages aren't supported. Change-Id: I2e74cc04c53eeefb25231d804752b53562b97371 Reviewed-on: https://go-review.googlesource.com/c/go/+/284138 Run-TryBot: Daniel Martí Trust: Daniel Martí Reviewed-by: Bryan C. Mills Reviewed-by: Robert Griesemer TryBot-Result: Go Bot --- src/cmd/gofmt/gofmt.go | 29 ++++++++--------------------- 1 file changed, 8 insertions(+), 21 deletions(-) diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go index 2793c2c2a4..fef86c941f 100644 --- a/src/cmd/gofmt/gofmt.go +++ b/src/cmd/gofmt/gofmt.go @@ -151,7 +151,7 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error if err != nil { return fmt.Errorf("computing diff: %s", err) } - fmt.Printf("diff -u %s %s\n", filepath.ToSlash(filename+".orig"), filepath.ToSlash(filename)) + fmt.Fprintf(out, "diff -u %s %s\n", filepath.ToSlash(filename+".orig"), filepath.ToSlash(filename)) out.Write(data) } } @@ -164,21 +164,15 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error } func visitFile(path string, f fs.DirEntry, err error) error { - if err == nil && isGoFile(f) { - err = processFile(path, nil, os.Stdout, false) + if err != nil || !isGoFile(f) { + return err } - // 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) { + if err := processFile(path, nil, os.Stdout, false); err != nil { 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 @@ -206,7 +200,8 @@ func gofmtMain() { initParserMode() initRewrite() - if flag.NArg() == 0 { + args := flag.Args() + if len(args) == 0 { if *write { fmt.Fprintln(os.Stderr, "error: cannot use -w with standard input") exitCode = 2 @@ -218,17 +213,9 @@ func gofmtMain() { return } - for i := 0; i < flag.NArg(); i++ { - path := flag.Arg(i) - switch dir, err := os.Stat(path); { - case err != nil: + for _, arg := range args { + if err := filepath.WalkDir(arg, visitFile); err != nil { report(err) - case dir.IsDir(): - walkDir(path) - default: - if err := processFile(path, nil, os.Stdout, false); err != nil { - report(err) - } } } } -- 2.50.0