libgo: update to go1.7rc3

    
    Reviewed-on: https://go-review.googlesource.com/25150

From-SVN: r238662

7 files changed, 20 insertions, 153 deletions

diff --git a/libgo/go/cmd/gofmt/gofmt.go b/libgo/go/cmd/gofmt/gofmt.go
index cfebeffe4a6..f29b6cb83d9 100644
--- a/libgo/go/cmd/gofmt/gofmt.go
+++ b/libgo/go/cmd/gofmt/gofmt.go
@@ -55,7 +55,6 @@ func report(err error) {
 func usage() {
 	fmt.Fprintf(os.Stderr, "usage: gofmt [flags] [path ...]\n")
 	flag.PrintDefaults()
-	os.Exit(2)
 }
 
 func initParserMode() {
@@ -143,7 +142,9 @@ func visitFile(path string, f os.FileInfo, err error) error {
 	if err == nil && isGoFile(f) {
 		err = processFile(path, nil, os.Stdout, false)
 	}
-	if err != nil {
+	// 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
diff --git a/libgo/go/cmd/gofmt/gofmt_test.go b/libgo/go/cmd/gofmt/gofmt_test.go
index d1edb7bcc16..dea012764b3 100644
--- a/libgo/go/cmd/gofmt/gofmt_test.go
+++ b/libgo/go/cmd/gofmt/gofmt_test.go
@@ -159,7 +159,7 @@ func TestCRLF(t *testing.T) {
 	if err != nil {
 		t.Error(err)
 	}
-	if bytes.Index(data, []byte("\r\n")) < 0 {
+	if !bytes.Contains(data, []byte("\r\n")) {
 		t.Errorf("%s contains no CR/LF's", input)
 	}
 
@@ -167,7 +167,7 @@ func TestCRLF(t *testing.T) {
 	if err != nil {
 		t.Error(err)
 	}
-	if bytes.Index(data, []byte("\r")) >= 0 {
+	if bytes.Contains(data, []byte("\r")) {
 		t.Errorf("%s contains CR's", golden)
 	}
 }
diff --git a/libgo/go/cmd/gofmt/internal.go b/libgo/go/cmd/gofmt/internal.go
index f764b10ebb0..cbc6983b612 100644
--- a/libgo/go/cmd/gofmt/internal.go
+++ b/libgo/go/cmd/gofmt/internal.go
@@ -28,9 +28,9 @@ func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) (
 ) {
 	// Try as whole source file.
 	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
+	// 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.
+	// try as a source fragment. Stop and return on any other error.
 	if err == nil || !fragmentOk || !strings.Contains(err.Error(), "expected 'package'") {
 		return
 	}
@@ -59,7 +59,7 @@ func parse(fset *token.FileSet, filename string, src []byte, fragmentOk bool) (
 
 	// If this is a statement list, make it a source file
 	// by inserting a package clause and turning the list
-	// into a function body.  This handles expressions too.
+	// into a function body. This handles expressions too.
 	// Insert using a ;, not a newline, so that the line numbers
 	// in fsrc match the ones in src. Add an extra '\n' before the '}'
 	// to make sure comments are flushed before the '}'.
diff --git a/libgo/go/cmd/gofmt/rewrite.go b/libgo/go/cmd/gofmt/rewrite.go
index 069f96622ca..550492bf29a 100644
--- a/libgo/go/cmd/gofmt/rewrite.go
+++ b/libgo/go/cmd/gofmt/rewrite.go
@@ -1,4 +1,4 @@
-// Copyright 2009 The Go Authors.  All rights reserved.
+// 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.
 
@@ -158,7 +158,7 @@ func isWildcard(s string) bool {
 // recording wildcard submatches in m.
 // If m == nil, match checks whether pattern == val.
 func match(m map[string]reflect.Value, pattern, val reflect.Value) bool {
-	// Wildcard matches any expression.  If it appears multiple
+	// Wildcard matches any expression. If it appears multiple
 	// times in the pattern, it must match the same expression
 	// each time.
 	if m != nil && pattern.IsValid() && pattern.Type() == identType {
diff --git a/libgo/go/cmd/gofmt/simplify.go b/libgo/go/cmd/gofmt/simplify.go
index 69f7bf23c0b..2ebf4cde0be 100644
--- a/libgo/go/cmd/gofmt/simplify.go
+++ b/libgo/go/cmd/gofmt/simplify.go
@@ -10,11 +10,9 @@ import (
 	"reflect"
 )
 
-type simplifier struct {
-	hasDotImport bool // package file contains: import . "some/import/path"
-}
+type simplifier struct{}
 
-func (s *simplifier) Visit(node ast.Node) ast.Visitor {
+func (s simplifier) Visit(node ast.Node) ast.Visitor {
 	switch n := node.(type) {
 	case *ast.CompositeLit:
 		// array, slice, and map composite literals may be simplified
@@ -68,10 +66,13 @@ func (s *simplifier) Visit(node ast.Node) ast.Visitor {
 		// a slice expression of the form: s[a:len(s)]
 		// can be simplified to: s[a:]
 		// if s is "simple enough" (for now we only accept identifiers)
-		if n.Max != nil || s.hasDotImport {
+		//
+		// Note: This may not be correct because len may have been redeclared in another
+		//       file belonging to the same package. However, this is extremely unlikely
+		//       and so far (April 2016, after years of supporting this rewrite feature)
+		//       has never come up, so let's keep it working as is (see also #15153).
+		if n.Max != nil {
 			// - 3-index slices always require the 2nd and 3rd index
-			// - if dot imports are present, we cannot be certain that an
-			//   unresolved "len" identifier refers to the predefined len()
 			break
 		}
 		if s, _ := n.X.(*ast.Ident); s != nil && s.Obj != nil {
@@ -118,20 +119,11 @@ func isBlank(x ast.Expr) bool {
 }
 
 func simplify(f *ast.File) {
-	var s simplifier
-
-	// determine if f contains dot imports
-	for _, imp := range f.Imports {
-		if imp.Name != nil && imp.Name.Name == "." {
-			s.hasDotImport = true
-			break
-		}
-	}
-
 	// remove empty declarations such as "const ()", etc
 	removeEmptyDeclGroups(f)
 
-	ast.Walk(&s, f)
+	var s simplifier
+	ast.Walk(s, f)
 }
 
 func removeEmptyDeclGroups(f *ast.File) {
diff --git a/libgo/go/cmd/gofmt/testdata/slices2.golden b/libgo/go/cmd/gofmt/testdata/slices2.golden
deleted file mode 100644
index ab657004e64..00000000000
--- a/libgo/go/cmd/gofmt/testdata/slices2.golden
+++ /dev/null
@@ -1,63 +0,0 @@
-//gofmt -s
-
-// Test cases for slice expression simplification.
-// Because of a dot import, these slices must remain untouched.
-package p
-
-import . "math"
-
-var (
-	a [10]byte
-	b [20]float32
-	s []int
-	t struct {
-		s []byte
-	}
-
-	_ = a[0:]
-	_ = a[1:10]
-	_ = a[2:len(a)]
-	_ = a[3:(len(a))]
-	_ = a[len(a) : len(a)-1]
-	_ = a[0:len(b)]
-
-	_ = a[:]
-	_ = a[:10]
-	_ = a[:len(a)]
-	_ = a[:(len(a))]
-	_ = a[:len(a)-1]
-	_ = a[:len(b)]
-
-	_ = s[0:]
-	_ = s[1:10]
-	_ = s[2:len(s)]
-	_ = s[3:(len(s))]
-	_ = s[len(a) : len(s)-1]
-	_ = s[0:len(b)]
-
-	_ = s[:]
-	_ = s[:10]
-	_ = s[:len(s)]
-	_ = s[:(len(s))]
-	_ = s[:len(s)-1]
-	_ = s[:len(b)]
-
-	_ = t.s[0:]
-	_ = t.s[1:10]
-	_ = t.s[2:len(t.s)]
-	_ = t.s[3:(len(t.s))]
-	_ = t.s[len(a) : len(t.s)-1]
-	_ = t.s[0:len(b)]
-
-	_ = t.s[:]
-	_ = t.s[:10]
-	_ = t.s[:len(t.s)]
-	_ = t.s[:(len(t.s))]
-	_ = t.s[:len(t.s)-1]
-	_ = t.s[:len(b)]
-)
-
-func _() {
-	s := s[0:len(s)]
-	_ = s
-}
diff --git a/libgo/go/cmd/gofmt/testdata/slices2.input b/libgo/go/cmd/gofmt/testdata/slices2.input
deleted file mode 100644
index ab657004e64..00000000000
--- a/libgo/go/cmd/gofmt/testdata/slices2.input
+++ /dev/null
@@ -1,63 +0,0 @@
-//gofmt -s
-
-// Test cases for slice expression simplification.
-// Because of a dot import, these slices must remain untouched.
-package p
-
-import . "math"
-
-var (
-	a [10]byte
-	b [20]float32
-	s []int
-	t struct {
-		s []byte
-	}
-
-	_ = a[0:]
-	_ = a[1:10]
-	_ = a[2:len(a)]
-	_ = a[3:(len(a))]
-	_ = a[len(a) : len(a)-1]
-	_ = a[0:len(b)]
-
-	_ = a[:]
-	_ = a[:10]
-	_ = a[:len(a)]
-	_ = a[:(len(a))]
-	_ = a[:len(a)-1]
-	_ = a[:len(b)]
-
-	_ = s[0:]
-	_ = s[1:10]
-	_ = s[2:len(s)]
-	_ = s[3:(len(s))]
-	_ = s[len(a) : len(s)-1]
-	_ = s[0:len(b)]
-
-	_ = s[:]
-	_ = s[:10]
-	_ = s[:len(s)]
-	_ = s[:(len(s))]
-	_ = s[:len(s)-1]
-	_ = s[:len(b)]
-
-	_ = t.s[0:]
-	_ = t.s[1:10]
-	_ = t.s[2:len(t.s)]
-	_ = t.s[3:(len(t.s))]
-	_ = t.s[len(a) : len(t.s)-1]
-	_ = t.s[0:len(b)]
-
-	_ = t.s[:]
-	_ = t.s[:10]
-	_ = t.s[:len(t.s)]
-	_ = t.s[:(len(t.s))]
-	_ = t.s[:len(t.s)-1]
-	_ = t.s[:len(b)]
-)
-
-func _() {
-	s := s[0:len(s)]
-	_ = s
-}