diff options
Diffstat (limited to 'src/cmd/gofmt/gofmt.go')
| -rw-r--r-- | src/cmd/gofmt/gofmt.go | 184 |
1 files changed, 111 insertions, 73 deletions
diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go index f322a2b0a..81da21ff1 100644 --- a/src/cmd/gofmt/gofmt.go +++ b/src/cmd/gofmt/gofmt.go @@ -87,13 +87,13 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error return err } - file, adjust, err := parse(fileSet, filename, src, stdin) + file, sourceAdj, indentAdj, err := parse(fileSet, filename, src, stdin) if err != nil { return err } if rewrite != nil { - if adjust == nil { + if sourceAdj == nil { file = rewrite(file) } else { fmt.Fprintf(os.Stderr, "warning: rewrite ignored for incomplete programs\n") @@ -106,15 +106,10 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error simplify(file) } - var buf bytes.Buffer - err = (&printer.Config{Mode: printerMode, Tabwidth: tabWidth}).Fprint(&buf, fileSet, file) + res, err := format(fileSet, file, sourceAdj, indentAdj, src, printer.Config{Mode: printerMode, Tabwidth: tabWidth}) if err != nil { return err } - res := buf.Bytes() - if adjust != nil { - res = adjust(src, res) - } if !bytes.Equal(src, res) { // formatting has changed @@ -240,19 +235,29 @@ func diff(b1, b2 []byte) (data []byte, err error) { } -// parse parses src, which was read from filename, -// as a Go source file or statement list. -func parse(fset *token.FileSet, filename string, src []byte, stdin bool) (*ast.File, func(orig, src []byte) []byte, error) { +// ---------------------------------------------------------------------------- +// Support functions +// +// The functions parse, format, and isSpace below are identical to the +// respective functions in src/go/format/format.go - keep them in sync! +// +// TODO(gri) Factor out this functionality, eventually. + +// parse parses src, which was read from the named file, +// as a Go source file, declaration, or statement list. +func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) ( + file *ast.File, + sourceAdj func(src []byte, indent int) []byte, + indentAdj int, + err error, +) { // Try as whole source file. - file, err := parser.ParseFile(fset, filename, src, parserMode) - if err == nil { - return file, nil, nil - } - // If the error is that the source file didn't begin with a - // package line and this is standard input, fall through to + file, err = parser.ParseFile(fset, filename, src, parserMode) + // If there's no error, return. If the error is that the source file didn't begin with a + // package line and source fragments are ok, fall through to // try as a source fragment. Stop and return on any other error. - if !stdin || !strings.Contains(err.Error(), "expected 'package'") { - return nil, nil, err + if err == nil || !fragmentOk || !strings.Contains(err.Error(), "expected 'package'") { + return } // If this is a declaration list, make it a source file @@ -262,19 +267,19 @@ func parse(fset *token.FileSet, filename string, src []byte, stdin bool) (*ast.F psrc := append([]byte("package p;"), src...) file, err = parser.ParseFile(fset, filename, psrc, parserMode) if err == nil { - adjust := func(orig, src []byte) []byte { + sourceAdj = func(src []byte, indent int) []byte { // Remove the package clause. // Gofmt has turned the ; into a \n. - src = src[len("package p\n"):] - return matchSpace(orig, src) + src = src[indent+len("package p\n"):] + return bytes.TrimSpace(src) } - return file, adjust, nil + return } // If the error is that the source file didn't begin with a // declaration, fall through to try as a statement list. // Stop and return on any other error. if !strings.Contains(err.Error(), "expected declaration") { - return nil, nil, err + return } // If this is a statement list, make it a source file @@ -285,65 +290,98 @@ func parse(fset *token.FileSet, filename string, src []byte, stdin bool) (*ast.F fsrc := append(append([]byte("package p; func _() {"), src...), '\n', '}') file, err = parser.ParseFile(fset, filename, fsrc, parserMode) if err == nil { - adjust := func(orig, src []byte) []byte { + sourceAdj = func(src []byte, indent int) []byte { + // Cap adjusted indent to zero. + if indent < 0 { + indent = 0 + } // Remove the wrapping. // Gofmt has turned the ; into a \n\n. - src = src[len("package p\n\nfunc _() {"):] - src = src[:len(src)-len("\n}\n")] - // Gofmt has also indented the function body one level. - // Remove that indent. - src = bytes.Replace(src, []byte("\n\t"), []byte("\n"), -1) - return matchSpace(orig, src) + // There will be two non-blank lines with indent, hence 2*indent. + src = src[2*indent+len("package p\n\nfunc _() {"):] + src = src[:len(src)-(indent+len("\n}\n"))] + return bytes.TrimSpace(src) } - return file, adjust, nil + // Gofmt has also indented the function body one level. + // Adjust that with indentAdj. + indentAdj = -1 } - // Failed, and out of options. - return nil, nil, err + // Succeeded, or out of options. + return } -func cutSpace(b []byte) (before, middle, after []byte) { - i := 0 - for i < len(b) && (b[i] == ' ' || b[i] == '\t' || b[i] == '\n') { - i++ - } - j := len(b) - for j > 0 && (b[j-1] == ' ' || b[j-1] == '\t' || b[j-1] == '\n') { - j-- - } - if i <= j { - return b[:i], b[i:j], b[j:] +// format formats the given package file originally obtained from src +// and adjusts the result based on the original source via sourceAdj +// and indentAdj. +func format( + fset *token.FileSet, + file *ast.File, + sourceAdj func(src []byte, indent int) []byte, + indentAdj int, + src []byte, + cfg printer.Config, +) ([]byte, error) { + if sourceAdj == nil { + // Complete source file. + var buf bytes.Buffer + err := cfg.Fprint(&buf, fset, file) + if err != nil { + return nil, err + } + return buf.Bytes(), nil } - return nil, nil, b[j:] -} -// matchSpace reformats src to use the same space context as orig. -// 1) If orig begins with blank lines, matchSpace inserts them at the beginning of src. -// 2) matchSpace copies the indentation of the first non-blank line in orig -// to every non-blank line in src. -// 3) matchSpace copies the trailing space from orig and uses it in place -// of src's trailing space. -func matchSpace(orig []byte, src []byte) []byte { - before, _, after := cutSpace(orig) - i := bytes.LastIndex(before, []byte{'\n'}) - before, indent := before[:i+1], before[i+1:] - - _, src, _ = cutSpace(src) - - var b bytes.Buffer - b.Write(before) - for len(src) > 0 { - line := src - if i := bytes.IndexByte(line, '\n'); i >= 0 { - line, src = line[:i+1], line[i+1:] - } else { - src = nil + // Partial source file. + // Determine and prepend leading space. + i, j := 0, 0 + for j < len(src) && isSpace(src[j]) { + if src[j] == '\n' { + i = j + 1 // byte offset of last line in leading space } - if len(line) > 0 && line[0] != '\n' { // not blank - b.Write(indent) + j++ + } + var res []byte + res = append(res, src[:i]...) + + // Determine and prepend indentation of first code line. + // Spaces are ignored unless there are no tabs, + // in which case spaces count as one tab. + indent := 0 + hasSpace := false + for _, b := range src[i:j] { + switch b { + case ' ': + hasSpace = true + case '\t': + indent++ } - b.Write(line) } - b.Write(after) - return b.Bytes() + if indent == 0 && hasSpace { + indent = 1 + } + for i := 0; i < indent; i++ { + res = append(res, '\t') + } + + // Format the source. + // Write it without any leading and trailing space. + cfg.Indent = indent + indentAdj + var buf bytes.Buffer + err := cfg.Fprint(&buf, fset, file) + if err != nil { + return nil, err + } + res = append(res, sourceAdj(buf.Bytes(), cfg.Indent)...) + + // Determine and append trailing space. + i = len(src) + for i > 0 && isSpace(src[i-1]) { + i-- + } + return append(res, src[i:]...), nil +} + +func isSpace(b byte) bool { + return b == ' ' || b == '\t' || b == '\n' || b == '\r' } |