Add 'Code generated by' comment

args/args.go

@@ -40,10 +40,11 @@ import (
 // before calling AddFlags.
 func Default() *GeneratorArgs {
 	return &GeneratorArgs{
-		OutputBase:              DefaultSourceTree(),
-		GoHeaderFilePath:        filepath.Join(DefaultSourceTree(), "k8s.io/gengo/boilerplate/boilerplate.go.txt"),
-		GeneratedBuildTag:       "ignore_autogenerated",
-		defaultCommandLineFlags: true,
+		OutputBase:                 DefaultSourceTree(),
+		GoHeaderFilePath:           filepath.Join(DefaultSourceTree(), "k8s.io/gengo/boilerplate/boilerplate.go.txt"),
+		GeneratedBuildTag:          "ignore_autogenerated",
+		GeneratedByCommentTemplate: "// Code generated by GENERATOR_NAME. DO NOT EDIT.",
+		defaultCommandLineFlags:    true,
 	}
 }
 
@@ -64,6 +65,11 @@ type GeneratorArgs struct {
 	// Where to get copyright header text.
 	GoHeaderFilePath string
 
+	// If GeneratedByCommentTemplate is set, generate a "Code generated by" comment
+	// above the package declaration of the format defined by this string.
+	// Any instances of "GENERATOR_NAME" will be replaced with the name of the code generator.
+	GeneratedByCommentTemplate string
+
 	// If true, only verify, don't write anything.
 	VerifyOnly bool
 
@@ -103,6 +109,14 @@ func (g *GeneratorArgs) LoadGoBoilerplate() ([]byte, error) {
 		return nil, err
 	}
 	b = bytes.Replace(b, []byte("YEAR"), []byte(strconv.Itoa(time.Now().Year())), -1)
+
+	if g.GeneratedByCommentTemplate != "" {
+		generatorPath := strings.Split(os.Args[0], "/")
+		generatorName := generatorPath[len(generatorPath)-1]
+		generatedByComment := strings.Replace(g.GeneratedByCommentTemplate, "GENERATOR_NAME", generatorName, -1)
+		s := fmt.Sprintf("%s\n\n", generatedByComment)
+		b = append(b, []byte(s)...)
+	}
 	return b, nil
 }