go/parser: Use explicit parser.Mode type.

R=r, bradfitz
CC=golang-dev
https://golang.org/cl/5574058

src/cmd/cgo/ast.go

@@ -16,7 +16,7 @@ import (
 	"strings"
 )
 
-func parse(name string, flags uint) *ast.File {
+func parse(name string, flags parser.Mode) *ast.File {
 	ast1, err := parser.ParseFile(fset, name, nil, flags)
 	if err != nil {
 		if list, ok := err.(scanner.ErrorList); ok {

src/cmd/godoc/parser.go

@@ -17,7 +17,7 @@ import (
 	"path/filepath"
 )
 
-func parseFile(fset *token.FileSet, filename string, mode uint) (*ast.File, error) {
+func parseFile(fset *token.FileSet, filename string, mode parser.Mode) (*ast.File, error) {
 	src, err := ReadFile(fs, filename)
 	if err != nil {
 		return nil, err

src/cmd/gofmt/gofmt.go

@@ -44,7 +44,7 @@ var (
 	fset        = token.NewFileSet()
 	exitCode    = 0
 	rewrite     func(*ast.File) *ast.File
-	parserMode  uint
+	parserMode  parser.Mode
 	printerMode uint
 )
 
@@ -60,7 +60,7 @@ func usage() {
 }
 
 func initParserMode() {
-	parserMode = uint(0)
+	parserMode = parser.Mode(0)
 	if *comments {
 		parserMode |= parser.ParseComments
 	}

src/pkg/go/parser/interface.go

@@ -45,12 +45,14 @@ func readSource(filename string, src interface{}) ([]byte, error) {
 	return ioutil.ReadFile(filename)
 }
 
-// The mode parameter to the Parse* functions is a set of flags (or 0).
+// A Mode value is a set of flags (or 0).
 // They control the amount of source code parsed and other optional
 // parser functionality.
 //
+type Mode uint
+
 const (
-	PackageClauseOnly uint = 1 << iota // parsing stops after package clause
+	PackageClauseOnly Mode = 1 << iota // parsing stops after package clause
 	ImportsOnly                        // parsing stops after import declarations
 	ParseComments                      // parse comments and add them to AST
 	Trace                              // print a trace of parsed productions
@@ -77,7 +79,7 @@ const (
 // representing the fragments of erroneous source code). Multiple errors
 // are returned via a scanner.ErrorList which is sorted by file position.
 //
-func ParseFile(fset *token.FileSet, filename string, src interface{}, mode uint) (*ast.File, error) {
+func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (*ast.File, error) {
 	text, err := readSource(filename, src)
 	if err != nil {
 		return nil, err
@@ -97,7 +99,7 @@ func ParseFile(fset *token.FileSet, filename string, src interface{}, mode uint)
 // returned. If a parse error occurred, a non-nil but incomplete map and the
 // first error encountered are returned.
 //
-func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, mode uint) (pkgs map[string]*ast.Package, first error) {
+func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, mode Mode) (pkgs map[string]*ast.Package, first error) {
 	fd, err := os.Open(path)
 	if err != nil {
 		return nil, err
@@ -117,7 +119,10 @@ func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, m
 				name := src.Name.Name
 				pkg, found := pkgs[name]
 				if !found {
-					pkg = &ast.Package{name, nil, nil, make(map[string]*ast.File)}
+					pkg = &ast.Package{
+						Name:  name,
+						Files: make(map[string]*ast.File),
+					}
 					pkgs[name] = pkg
 				}
 				pkg.Files[filename] = src

src/pkg/go/parser/parser.go

@@ -23,7 +23,7 @@ type parser struct {
 	scanner scanner.Scanner
 
 	// Tracing/debugging
-	mode   uint // parsing mode
+	mode   Mode // parsing mode
 	trace  bool // == (mode & Trace != 0)
 	indent uint // indentation used for tracing output
 
@@ -52,7 +52,7 @@ type parser struct {
 	targetStack [][]*ast.Ident // stack of unresolved labels
 }
 
-func (p *parser) init(fset *token.FileSet, filename string, src []byte, mode uint) {
+func (p *parser) init(fset *token.FileSet, filename string, src []byte, mode Mode) {
 	p.file = fset.AddFile(filename, fset.Base(), len(src))
 	var m uint
 	if mode&ParseComments != 0 {