go/format, cmd/gofmt: added missing comments, minor internal cleanup

This is a minor cleanup following CL 142360043:

The internal parse and format functions in both packages
were almost identical - made them identical by adding an
extra parameter, and documented them as identical.

Eventually we should find a nice way to factor these functions
out, but we cannot do this now while in prep for 1.4.

No functionality change.

LGTM=adonovan
R=adonovan
CC=golang-codereviews
https://golang.org/cl/146520043

diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
index 854295724815fb4849cf8bccba87d6253e7eeebd..81da21ff109ac862045f92678437d57351546d57 100644 (file)
--- a/src/cmd/gofmt/gofmt.go
+++ b/src/cmd/gofmt/gofmt.go
@@ -106,7 +106,7 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error
                simplify(file)
        }
 
-       res, err := format(fileSet, file, sourceAdj, indentAdj, src)
+       res, err := format(fileSet, file, sourceAdj, indentAdj, src, printer.Config{Mode: printerMode, Tabwidth: tabWidth})
        if err != nil {
                return err
        }
@@ -235,8 +235,16 @@ 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.
+// ----------------------------------------------------------------------------
+// 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,
@@ -303,11 +311,21 @@ func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) (
        return
 }
 
-func format(fset *token.FileSet, file *ast.File, sourceAdj func(src []byte, indent int) []byte, indentAdj int, src []byte) ([]byte, error) {
+// 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 := (&printer.Config{Mode: printerMode, Tabwidth: tabWidth}).Fprint(&buf, fset, file)
+               err := cfg.Fprint(&buf, fset, file)
                if err != nil {
                        return nil, err
                }
@@ -348,7 +366,6 @@ func format(fset *token.FileSet, file *ast.File, sourceAdj func(src []byte, inde
 
        // Format the source.
        // Write it without any leading and trailing space.
-       cfg := &printer.Config{Mode: printerMode, Tabwidth: tabWidth}
        cfg.Indent = indent + indentAdj
        var buf bytes.Buffer
        err := cfg.Fprint(&buf, fset, file)

diff --git a/src/go/format/format.go b/src/go/format/format.go
index 08a9047b99fefb01de458673b7345cd0226490c0..668a42df2df80da0e6c923c2be100e940ea6d2a2 100644 (file)
--- a/src/go/format/format.go
+++ b/src/go/format/format.go
@@ -87,7 +87,13 @@ func Source(src []byte) ([]byte, error) {
                return nil, err
        }
 
-       return format(fset, file, sourceAdj, indentAdj, src)
+       if sourceAdj == nil {
+               // Complete source file.
+               // TODO(gri) consider doing this always.
+               ast.SortImports(fset, file)
+       }
+
+       return format(fset, file, sourceAdj, indentAdj, src, config)
 }
 
 func hasUnsortedImports(file *ast.File) bool {
@@ -108,8 +114,16 @@ func hasUnsortedImports(file *ast.File) bool {
        return false
 }
 
-// parse parses src, which was read from filename,
-// as a Go source file or statement list.
+// ----------------------------------------------------------------------------
+// Support functions
+//
+// The functions parse, format, and isSpace below are identical to the
+// respective functions in cmd/gofmt/gofmt.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,
@@ -176,12 +190,21 @@ func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) (
        return
 }
 
-func format(fset *token.FileSet, file *ast.File, sourceAdj func(src []byte, indent int) []byte, indentAdj int, src []byte) ([]byte, error) {
+// 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.
-               ast.SortImports(fset, file)
                var buf bytes.Buffer
-               err := config.Fprint(&buf, fset, file)
+               err := cfg.Fprint(&buf, fset, file)
                if err != nil {
                        return nil, err
                }
@@ -222,7 +245,6 @@ func format(fset *token.FileSet, file *ast.File, sourceAdj func(src []byte, inde
 
        // Format the source.
        // Write it without any leading and trailing space.
-       cfg := config
        cfg.Indent = indent + indentAdj
        var buf bytes.Buffer
        err := cfg.Fprint(&buf, fset, file)