[Proto] Keep track of the names of Services, Messages, and Enums

In order to construct a fully qualified Java import from the proto file,
we need to know the values of the "java_package" option as well as the
services, messages, and enums in the proto file. The "java_pacakge"
option is already recorded. In this commit, we add support for parsing
the names of the services, message, and enums of a proto file and
tracking them in the FileInfo struct.

language/proto/fileinfo.go

@@ -36,6 +36,10 @@ type FileInfo struct {
 	Imports []string
 
 	HasServices bool
+
+	Services []string
+	Messages []string
+	Enums []string
 }
 
 // Option represents a top-level option statement in a .proto file. Only
@@ -77,6 +81,36 @@ func protoFileInfo(dir, name string) FileInfo {
 		case match[serviceSubexpIndex] != nil:
 			info.HasServices = true
 
+			// match is of the format "service ServiceName {".
+			// extract just the service name
+			fullMatch := string(match[serviceSubexpIndex])
+			serviceName, ok := extractObjectName(fullMatch)
+
+			if ok {
+				info.Services = append(info.Services, serviceName)
+			}
+
+		case match[messageSubexpIndex] != nil:
+			// match is of the format "message MessageName {".
+			// extract just the message name
+			fullMatch := string(match[messageSubexpIndex])
+			messageName, ok := extractObjectName(fullMatch)
+
+			if ok {
+				info.Messages = append(info.Messages, messageName)
+			}
+
+		case match[enumSubexpIndex] != nil:
+			// match is of the format "enum EnumName {".
+			// extract just the enum name
+			fullMatch := string(match[enumSubexpIndex])
+			enumName, ok := extractObjectName(fullMatch)
+
+			if ok {
+				info.Enums = append(info.Enums, enumName)
+			}
+
+
 		default:
 			// Comment matched. Nothing to extract.
 		}
@@ -92,6 +126,8 @@ const (
 	optkeySubexpIndex  = 3
 	optvalSubexpIndex  = 4
 	serviceSubexpIndex = 5
+	messageSubexpIndex = 6
+	enumSubexpIndex = 7
 )
 
 // Based on https://developers.google.com/protocol-buffers/docs/reference/proto3-spec
@@ -107,8 +143,10 @@ func buildProtoRegexp() *regexp.Regexp {
 	packageStmt := `\bpackage\s*(?P<package>` + fullIdent + `)\s*;`
 	optionStmt := `\boption\s*(?P<optkey>` + fullIdent + `)\s*=\s*(?P<optval>` + strLit + `)\s*;`
 	serviceStmt := `(?P<service>service\s+` + ident + `\s*{)`
+	messageStmt := `(?P<message>message\s+` + ident + `\s*{)`
+	enumStmt := `(?P<enum>enum\s+` + ident + `\s*{)`
 	comment := `//[^\n]*`
-	protoReSrc := strings.Join([]string{importStmt, packageStmt, optionStmt, serviceStmt, comment}, "|")
+	protoReSrc := strings.Join([]string{importStmt, packageStmt, optionStmt, serviceStmt, messageStmt, enumStmt, comment}, "|")
 	return regexp.MustCompile(protoReSrc)
 }
 
@@ -136,3 +174,13 @@ func unquoteProtoString(q []byte) string {
 	}
 	return s
 }
+
+func extractObjectName(fullMatch string) (response string, ok bool) {
+	fields := strings.Fields(fullMatch)
+	if len(fields) < 2 {
+	  // expect as least two fields. Input is malformed
+	  return "", false
+	}
+
+	return strings.TrimSuffix(fields[1], "{"), true
+  }

language/proto/fileinfo_test.go

@@ -30,6 +30,8 @@ func TestProtoRegexpGroupNames(t *testing.T) {
 		"optkey":  optkeySubexpIndex,
 		"optval":  optvalSubexpIndex,
 		"service": serviceSubexpIndex,
+		"message": messageSubexpIndex,
+		"enum": enumSubexpIndex,
 	}
 	for name, index := range nameMap {
 		if names[index] != name {
@@ -109,6 +111,7 @@ import "second.proto";`,
 			proto: `service ChatService {}`,
 			want: FileInfo{
 				HasServices: true,
+				Services: []string{"ChatService"},
 			},
 		},
 		{
@@ -117,6 +120,7 @@ import "second.proto";`,
 			proto: `service      ChatService   {}`,
 			want: FileInfo{
 				HasServices: true,
+				Services: []string{"ChatService"},
 			},
 		},
 		{
@@ -125,6 +129,7 @@ import "second.proto";`,
 			proto: `service      ChatService{}`,
 			want: FileInfo{
 				HasServices: true,
+				Services: []string{"ChatService"},
 			},
 		},
 		{
@@ -141,6 +146,80 @@ import "second.proto";`,
 			proto: `message serviceAccount { string service = 1; }`,
 			want: FileInfo{
 				HasServices: false,
+				Messages: []string{"serviceAccount"},
+			},
+		},{
+			desc: "multiple service names",
+			name:  "service.proto",
+			proto: `service ServiceA { string service = 1; }
+
+			service ServiceB { string service = 1; }
+
+			service ServiceC{ string service = 1; }
+
+			serviceServiceD { string service = 1; }
+
+			service message { string service = 1; }
+
+			service enum { string service = 1; }
+			`,
+			want: FileInfo{
+				HasServices: true,
+				Services: []string{"ServiceA", "ServiceB", "ServiceC", "message", "enum"},
+			},
+		},{
+			desc: "multiple message names",
+			name:  "messages.proto",
+			proto: `message MessageA { string message = 1; }
+
+			message    MessageB    { string message = 1; }
+
+			message MessageC{ string message = 1; }
+
+			messageMessageD { string message = 1; }
+
+			message service { string service = 1; }
+
+			message enum { string service = 1; }
+			`,
+			want: FileInfo{
+				Messages: []string{"MessageA", "MessageB", "MessageC", "service", "enum"},
+			},
+		},{
+			desc: "multiple enum names",
+			name:  "enums.proto",
+			proto: `enum EnumA {
+			    ENUM_VALUE_A = 1;
+			    ENUM_VALUE_B = 2;
+			}
+
+			enum    EnumB    {
+			    ENUM_VALUE_C = 1;
+			    ENUM_VALUE_D = 2;
+			}
+
+			enum EnumC{
+			    ENUM_VALUE_E = 1;
+			    ENUM_VALUE_F = 2;
+			}
+
+			enumEnumD {
+			    ENUM_VALUE_G = 1;
+			    ENUM_VALUE_H = 2;
+			}
+
+			enum service {
+			    ENUM_VALUE_I = 1;
+			    ENUM_VALUE_J = 2;
+			}
+
+			enum message {
+			    ENUM_VALUE_K = 1;
+			    ENUM_VALUE_L = 2;
+			}
+			`,
+			want: FileInfo{
+				Enums: []string{"EnumA", "EnumB", "EnumC", "service", "message"},
 			},
 		},
 	} {
@@ -162,6 +241,9 @@ import "second.proto";`,
 				Imports:     got.Imports,
 				Options:     got.Options,
 				HasServices: got.HasServices,
+				Services:    got.Services,
+				Messages:    got.Messages,
+				Enums:       got.Enums,
 			}
 			if !reflect.DeepEqual(got, tc.want) {
 				t.Errorf("got %#v; want %#v", got, tc.want)

language/proto/generate_test.go

@@ -175,6 +175,7 @@ func TestGeneratePackage(t *testing.T) {
 					"protos/sub/sub.proto",
 				},
 				HasServices: true,
+				Services: []string{"Quux"},
 			},
 		},
 		Imports: map[string]bool{
@@ -235,6 +236,7 @@ func TestFileModeImports(t *testing.T) {
 				Path:        filepath.Join(dir, "foo.proto"),
 				Name:        "foo.proto",
 				PackageName: "file_mode",
+				Messages: []string{"Foo"},
 			},
 		},
 		Imports: map[string]bool{},
@@ -252,6 +254,7 @@ func TestFileModeImports(t *testing.T) {
 				Imports: []string{
 					"file_mode/foo.proto",
 				},
+				Messages: []string{"Bar"},
 			},
 		},
 		// Imports should contain foo.proto. This is specific to file mode.