goprotobuf: Miscellaneous cleanups.

No significant changes except for debuggers.

LGTM=nigeltao
R=nigeltao
CC=golang-codereviews
https://codereview.appspot.com/166720043

4 files changed, 9 insertions, 7 deletions

diff --git a/proto/decode.go b/proto/decode.go
index 49a487a..cadee03 100644
--- a/proto/decode.go
+++ b/proto/decode.go
@@ -362,7 +362,7 @@ func (o *Buffer) unmarshalType(st reflect.Type, prop *StructProperties, is_group
 		}
 		tag := int(u >> 3)
 		if tag <= 0 {
-			return fmt.Errorf("proto: %s: illegal tag %d", st, tag)
+			return fmt.Errorf("proto: %s: illegal tag %d (wire type %d)", st, tag, wire)
 		}
 		fieldnum, ok := prop.decoderTags.get(tag)
 		if !ok {
diff --git a/proto/equal.go b/proto/equal.go
index 42542e6..60dda9f 100644
--- a/proto/equal.go
+++ b/proto/equal.go
@@ -57,7 +57,7 @@ Equality is defined in this way:
     although represented by []byte, is not a repeated field)
   - Two unset fields are equal.
   - Two unknown field sets are equal if their current
-    encoded state is equal. (TODO)
+    encoded state is equal.
   - Two extension sets are equal iff they have corresponding
     elements that are pairwise equal.
   - Every other combination of things are not equal.
diff --git a/proto/properties.go b/proto/properties.go
index ee65ff5..0ed1497 100644
--- a/proto/properties.go
+++ b/proto/properties.go
@@ -300,7 +300,7 @@ func (p *Properties) setEncAndDec(typ reflect.Type, lockGetProp bool) {
 
 	switch t1 := typ; t1.Kind() {
 	default:
-		fmt.Fprintf(os.Stderr, "proto: no coders for %T\n", t1)
+		fmt.Fprintf(os.Stderr, "proto: no coders for %v\n", t1)
 
 	case reflect.Ptr:
 		switch t2 := t1.Elem(); t2.Kind() {
diff --git a/protoc-gen-go/generator/generator.go b/protoc-gen-go/generator/generator.go
index f4902c6..6d281b4 100644
--- a/protoc-gen-go/generator/generator.go
+++ b/protoc-gen-go/generator/generator.go
@@ -242,6 +242,7 @@ type FileDescriptor struct {
 	exported map[Object][]symbol
 
 	index int // The index of this file in the list of files to generate code for
+
 }
 
 // PackageName is the package name we'll use in the generated code to refer to this file.
@@ -1268,7 +1269,7 @@ func (g *Generator) generateEnum(enum *EnumDescriptor) {
 //	def= string representation of the default value, if any.
 // The default value must be in a representation that can be used at run-time
 // to generate the default value. Thus bools become 0 and 1, for instance.
-func (g *Generator) goTag(field *descriptor.FieldDescriptorProto, wiretype string) string {
+func (g *Generator) goTag(message *Descriptor, field *descriptor.FieldDescriptorProto, wiretype string) string {
 	optrepreq := ""
 	switch {
 	case isOptional(field):
@@ -1488,7 +1489,7 @@ func (g *Generator) generateMessage(message *Descriptor) {
 		usedNames[fieldName] = true
 		typename, wiretype := g.GoType(message, field)
 		jsonName := *field.Name
-		tag := fmt.Sprintf("protobuf:%s json:%q", g.goTag(field, wiretype), jsonName+",omitempty")
+		tag := fmt.Sprintf("protobuf:%s json:%q", g.goTag(message, field, wiretype), jsonName+",omitempty")
 		fieldNames[field] = fieldName
 		fieldGetterNames[field] = fieldGetterName
 		g.P(fieldName, "\t", typename, "\t`", tag, "`")
@@ -1753,10 +1754,11 @@ func (g *Generator) generateMessage(message *Descriptor) {
 func (g *Generator) generateExtension(ext *ExtensionDescriptor) {
 	ccTypeName := ext.DescName()
 
-	extendedType := "*" + g.TypeName(g.ObjectNamed(*ext.Extendee))
+	extDesc := g.ObjectNamed(*ext.Extendee).(*Descriptor)
+	extendedType := "*" + g.TypeName(extDesc)
 	field := ext.FieldDescriptorProto
 	fieldType, wireType := g.GoType(ext.parent, field)
-	tag := g.goTag(field, wireType)
+	tag := g.goTag(extDesc, field, wireType)
 	g.RecordTypeUse(*ext.Extendee)
 	if n := ext.FieldDescriptorProto.TypeName; n != nil {
 		// foreign extension type