Merge remote-tracking branch 'refs/remotes/google/master'

.gitignore

@@ -111,5 +111,7 @@ conformance/conformance.pb.h
 conformance/Conformance.pbobjc.h
 conformance/Conformance.pbobjc.m
 conformance/conformance.rb
+conformance/google/
 conformance/javac_middleman
+conformance/lite/
 conformance/protoc_middleman

.travis.yml

@@ -10,7 +10,7 @@ os:
 # The Objective C build needs Xcode 7.0 or later.
 osx_image: xcode7.2
 script:
-  - ./travis.sh $CONFIG
+  - ./tests.sh $CONFIG
 env:
   - CONFIG=cpp
   - CONFIG=cpp_distcheck
@@ -71,5 +71,14 @@ matrix:
     # we moved to an OS X image that is 10.11.
     - os: osx
       env: CONFIG=python_cpp
+    # xctool 0.2.8 seems to have a bug where it randomly kills tests saying
+    # they failed.
+    #   https://github.com/facebook/xctool/issues/619
+    #   https://github.com/google/protobuf/issues/1232
+    # travis updated their images to include 0.2.8:
+    #   https://blog.travis-ci.com/2016-03-23-xcode-image-updates
+    # Mark the iOS test as flakey so these failures don't turn things red.
+    - os: osx
+      env: CONFIG=objectivec_ios
 notifications:
   email: false

BUILD

@@ -15,16 +15,58 @@ COPTS = [
     "-Wno-error=unused-function",
 ]
 
-# Bazel should provide portable link_opts for pthread.
-LINK_OPTS = ["-lpthread"]
+config_setting(
+    name = "android",
+    values = {
+        "crosstool_top": "//external:android/crosstool",
+    },
+)
+
+# Android builds do not need to link in a separate pthread library.
+LINK_OPTS = select({
+    ":android": [],
+    "//conditions:default": ["-lpthread"],
+})
 
 load(
     "protobuf",
     "cc_proto_library",
     "py_proto_library",
+    "internal_gen_well_known_protos_java",
     "internal_protobuf_py_tests",
 )
 
+config_setting(
+    name = "ios_armv7",
+    values = {
+        "ios_cpu": "armv7",
+    },
+)
+
+config_setting(
+    name = "ios_armv7s",
+    values = {
+        "ios_cpu": "armv7s",
+    },
+)
+
+config_setting(
+    name = "ios_arm64",
+    values = {
+        "ios_cpu": "arm64",
+    },
+)
+
+IOS_ARM_COPTS = COPTS + [
+    "-DOS_IOS",
+    "-miphoneos-version-min=7.0",
+    "-arch armv7",
+    "-arch armv7s",
+    "-arch arm64",
+    "-D__thread=",
+    "-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS9.2.sdk/",
+]
+
 cc_library(
     name = "protobuf_lite",
     srcs = [
@@ -54,7 +96,12 @@ cc_library(
         "src/google/protobuf/wire_format_lite.cc",
     ],
     hdrs = glob(["src/google/protobuf/**/*.h"]),
-    copts = COPTS,
+    copts = select({
+        ":ios_armv7": IOS_ARM_COPTS,
+        ":ios_armv7s": IOS_ARM_COPTS,
+        ":ios_arm64": IOS_ARM_COPTS,
+        "//conditions:default": COPTS,
+    }),
     includes = ["src/"],
     linkopts = LINK_OPTS,
     visibility = ["//visibility:public"],
@@ -119,7 +166,12 @@ cc_library(
         "src/google/protobuf/wrappers.pb.cc",
     ],
     hdrs = glob(["src/**/*.h"]),
-    copts = COPTS,
+    copts = select({
+        ":ios_armv7": IOS_ARM_COPTS,
+        ":ios_armv7s": IOS_ARM_COPTS,
+        ":ios_arm64": IOS_ARM_COPTS,
+        "//conditions:default": COPTS,
+    }),
     includes = ["src/"],
     linkopts = LINK_OPTS,
     visibility = ["//visibility:public"],
@@ -152,6 +204,12 @@ RELATIVE_WELL_KNOWN_PROTOS = [
 
 WELL_KNOWN_PROTOS = ["src/" + s for s in RELATIVE_WELL_KNOWN_PROTOS]
 
+filegroup(
+    name = "well_known_protos",
+    srcs = WELL_KNOWN_PROTOS,
+    visibility = ["//visibility:public"],
+)
+
 cc_proto_library(
     name = "cc_wkt_protos",
     srcs = WELL_KNOWN_PROTOS,
@@ -208,6 +266,7 @@ cc_library(
         "src/google/protobuf/compiler/java/java_enum_field_lite.cc",
         "src/google/protobuf/compiler/java/java_enum_lite.cc",
         "src/google/protobuf/compiler/java/java_extension.cc",
+        "src/google/protobuf/compiler/java/java_extension_lite.cc",
         "src/google/protobuf/compiler/java/java_field.cc",
         "src/google/protobuf/compiler/java/java_file.cc",
         "src/google/protobuf/compiler/java/java_generator.cc",
@@ -318,6 +377,8 @@ RELATIVE_TEST_PROTOS = [
     "google/protobuf/unittest_preserve_unknown_enum.proto",
     "google/protobuf/unittest_preserve_unknown_enum2.proto",
     "google/protobuf/unittest_proto3_arena.proto",
+    "google/protobuf/unittest_proto3_arena_lite.proto",
+    "google/protobuf/unittest_proto3_lite.proto",
     "google/protobuf/unittest_well_known_types.proto",
     "google/protobuf/util/internal/testdata/anys.proto",
     "google/protobuf/util/internal/testdata/books.proto",
@@ -378,6 +439,7 @@ cc_test(
         "src/google/protobuf/compiler/cpp/cpp_bootstrap_unittest.cc",
         "src/google/protobuf/compiler/cpp/cpp_plugin_unittest.cc",
         "src/google/protobuf/compiler/cpp/cpp_unittest.cc",
+        "src/google/protobuf/compiler/cpp/metadata_test.cc",
         "src/google/protobuf/compiler/csharp/csharp_generator_unittest.cc",
         "src/google/protobuf/compiler/importer_unittest.cc",
         "src/google/protobuf/compiler/java/java_doc_comment_unittest.cc",
@@ -402,7 +464,9 @@ cc_test(
         "src/google/protobuf/message_unittest.cc",
         "src/google/protobuf/no_field_presence_test.cc",
         "src/google/protobuf/preserve_unknown_enum_test.cc",
+        "src/google/protobuf/proto3_arena_lite_unittest.cc",
         "src/google/protobuf/proto3_arena_unittest.cc",
+        "src/google/protobuf/proto3_lite_unittest.cc",
         "src/google/protobuf/reflection_ops_unittest.cc",
         "src/google/protobuf/repeated_field_reflection_unittest.cc",
         "src/google/protobuf/repeated_field_unittest.cc",
@@ -457,16 +521,8 @@ cc_test(
 ################################################################################
 # Java support
 ################################################################################
-genrule(
-    name = "gen_well_known_protos_java",
+internal_gen_well_known_protos_java(
     srcs = WELL_KNOWN_PROTOS,
-    outs = [
-        "wellknown.srcjar",
-    ],
-    cmd = "$(location :protoc) --java_out=$(@D)/wellknown.jar" +
-          " -Isrc $(SRCS) " +
-          " && mv $(@D)/wellknown.jar $(@D)/wellknown.srcjar",
-    tools = [":protoc"],
 )
 
 java_library(
@@ -479,6 +535,19 @@ java_library(
     visibility = ["//visibility:public"],
 )
 
+java_library(
+    name = "protobuf_java_util",
+    srcs = glob([
+        "java/util/src/main/java/com/google/protobuf/util/*.java",
+    ]),
+    deps = [
+        "protobuf_java",
+        "//external:gson",
+        "//external:guava",
+    ],
+    visibility = ["//visibility:public"],
+)
+
 ################################################################################
 # Python support
 ################################################################################
@@ -495,6 +564,7 @@ py_library(
             "python/google/protobuf/internal/test_util.py",
         ],
     ),
+    srcs_version = "PY2AND3",
     imports = ["python"],
 )
 
@@ -579,6 +649,7 @@ py_proto_library(
     include = "src",
     default_runtime = "",
     protoc = ":protoc",
+    srcs_version = "PY2AND3",
     deps = [":protobuf_python"],
 )
 
@@ -591,6 +662,7 @@ py_proto_library(
     include = "python",
     default_runtime = ":protobuf_python",
     protoc = ":protoc",
+    srcs_version = "PY2AND3",
     deps = [":python_common_test_protos"],
 )
 

Makefile.am

@@ -9,7 +9,7 @@ AUTOMAKE_OPTIONS = foreign
 SUBDIRS = . src
 
 # Always include gmock in distributions.
-DIST_SUBDIRS = $(subdirs) src conformance
+DIST_SUBDIRS = $(subdirs) src conformance benchmarks
 
 # Build gmock before we build protobuf tests.  We don't add gmock to SUBDIRS
 # because then "make check" would also build and run all of gmock's own tests,
@@ -36,6 +36,10 @@ clean-local:
 	  echo "Making clean in conformance"; \
 	  cd conformance && $(MAKE) $(AM_MAKEFLAGS) clean; \
 	fi; \
+	if test -e benchmarks/Makefile; then \
+	  echo "Making clean in benchmarks"; \
+	  cd benchmarks && $(MAKE) $(AM_MAKEFLAGS) clean; \
+	fi; \
 	if test -e objectivec/DevTools; then \
 	  echo "Cleaning any ObjC pyc files"; \
 	  rm -f objectivec/DevTools/*.pyc; \
@@ -154,6 +158,7 @@ csharp_EXTRA_DIST=                                                           \
   csharp/src/Google.Protobuf/Reflection/MethodDescriptor.cs                  \
   csharp/src/Google.Protobuf/Reflection/OneofAccessor.cs                     \
   csharp/src/Google.Protobuf/Reflection/OneofDescriptor.cs                   \
+  csharp/src/Google.Protobuf/Reflection/OriginalNameAttribute.cs             \
   csharp/src/Google.Protobuf/Reflection/PackageDescriptor.cs                 \
   csharp/src/Google.Protobuf/Reflection/PartialClasses.cs                    \
   csharp/src/Google.Protobuf/Reflection/ReflectionUtil.cs                    \
@@ -193,6 +198,8 @@ java_EXTRA_DIST=
   java/core/src/main/java/com/google/protobuf/BlockingRpcChannel.java              \
   java/core/src/main/java/com/google/protobuf/BlockingService.java                 \
   java/core/src/main/java/com/google/protobuf/BooleanArrayList.java                \
+  java/core/src/main/java/com/google/protobuf/ByteBufferWriter.java                \
+  java/core/src/main/java/com/google/protobuf/ByteOutput.java                      \
   java/core/src/main/java/com/google/protobuf/ByteString.java                      \
   java/core/src/main/java/com/google/protobuf/CodedInputStream.java                \
   java/core/src/main/java/com/google/protobuf/CodedOutputStream.java               \
@@ -243,6 +250,8 @@ java_EXTRA_DIST=
   java/core/src/main/java/com/google/protobuf/SmallSortedMap.java                  \
   java/core/src/main/java/com/google/protobuf/TextFormat.java                      \
   java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java               \
+  java/core/src/main/java/com/google/protobuf/TextFormatParseInfoTree.java         \
+  java/core/src/main/java/com/google/protobuf/TextFormatParseLocation.java         \
   java/core/src/main/java/com/google/protobuf/UninitializedMessageException.java   \
   java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java                 \
   java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java             \
@@ -254,6 +263,7 @@ java_EXTRA_DIST=
   java/core/src/test/java/com/google/protobuf/AnyTest.java                         \
   java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java            \
   java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java           \
+  java/core/src/test/java/com/google/protobuf/ByteBufferWriterTest.java            \
   java/core/src/test/java/com/google/protobuf/ByteStringTest.java                  \
   java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java                   \
   java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java            \
@@ -262,6 +272,7 @@ java_EXTRA_DIST=
   java/core/src/test/java/com/google/protobuf/DescriptorsTest.java                 \
   java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java             \
   java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java              \
+  java/core/src/test/java/com/google/protobuf/EnumTest.java                        \
   java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java               \
   java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java              \
   java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java        \
@@ -294,6 +305,8 @@ java_EXTRA_DIST=
   java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java              \
   java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java              \
   java/core/src/test/java/com/google/protobuf/TestUtil.java                        \
+  java/core/src/test/java/com/google/protobuf/TextFormatParseInfoTreeTest.java     \
+  java/core/src/test/java/com/google/protobuf/TextFormatParseLocationTest.java     \
   java/core/src/test/java/com/google/protobuf/TextFormatTest.java                  \
   java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java            \
   java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java         \
@@ -381,13 +394,11 @@ objectivec_EXTRA_DIST=                                                       \
   objectivec/DevTools/full_mac_build.sh                                      \
   objectivec/DevTools/pddm.py                                                \
   objectivec/DevTools/pddm_tests.py                                          \
-  objectivec/generate_descriptors_proto.sh                                   \
+  objectivec/generate_well_known_types.sh                                    \
   objectivec/google/protobuf/Any.pbobjc.h                                    \
   objectivec/google/protobuf/Any.pbobjc.m                                    \
   objectivec/google/protobuf/Api.pbobjc.h                                    \
   objectivec/google/protobuf/Api.pbobjc.m                                    \
-  objectivec/google/protobuf/Descriptor.pbobjc.h                             \
-  objectivec/google/protobuf/Descriptor.pbobjc.m                             \
   objectivec/google/protobuf/Duration.pbobjc.h                               \
   objectivec/google/protobuf/Duration.pbobjc.m                               \
   objectivec/google/protobuf/Empty.pbobjc.h                                  \

Protobuf.podspec

@@ -17,7 +17,6 @@ Pod::Spec.new do |s|
   s.source_files = 'objectivec/*.{h,m}',
                    'objectivec/google/protobuf/Any.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Api.pbobjc.{h,m}',
-                   'objectivec/google/protobuf/Descriptor.pbobjc.{h,m}',
                    'objectivec/google/protobuf/Duration.pbobjc.h',
                    'objectivec/google/protobuf/Empty.pbobjc.{h,m}',
                    'objectivec/google/protobuf/FieldMask.pbobjc.{h,m}',

WORKSPACE

@@ -31,3 +31,23 @@ bind(
     name = "six",
     actual = "@six_archive//:six",
 )
+
+maven_jar(
+  name = "guava_maven",
+  artifact = "com.google.guava:guava:18.0",
+)
+
+bind(
+    name = "guava",
+    actual = "@guava_maven//jar",
+)
+
+maven_jar(
+  name = "gson_maven",
+  artifact = "com.google.code.gson:gson:2.3",
+)
+
+bind(
+    name = "gson",
+    actual = "@gson_maven//jar",
+)

benchmarks/Makefile.am

@@ -0,0 +1,69 @@
+
+benchmarks_protoc_inputs =                                     \
+  benchmarks.proto                                             \
+  benchmark_messages_proto3.proto
+
+benchmarks_protoc_inputs_proto2 =                              \
+  benchmark_messages_proto2.proto
+
+benchmarks_protoc_outputs =                                    \
+  benchmarks.pb.cc                                             \
+  benchmarks.pb.h                                              \
+  benchmark_messages_proto3.pb.cc                              \
+  benchmark_messages_proto3.pb.h
+
+benchmarks_protoc_outputs_proto2 =                             \
+  benchmark_messages_proto2.pb.cc                              \
+  benchmark_messages_proto2.pb.h
+
+bin_PROGRAMS = generate-datasets
+
+generate_datasets_LDADD = $(top_srcdir)/src/libprotobuf.la
+generate_datasets_SOURCES = generate_datasets.cc
+generate_datasets_CPPFLAGS = -I$(top_srcdir)/src -I$(srcdir)
+nodist_generate_datasets_SOURCES =                             \
+  $(benchmarks_protoc_outputs)                                 \
+  $(benchmarks_protoc_outputs_proto2)
+
+# Explicit deps because BUILT_SOURCES are only done before a "make all/check"
+# so a direct "make test_cpp" could fail if parallel enough.
+# See: https://www.gnu.org/software/automake/manual/html_node/Built-Sources-Example.html#Recording-Dependencies-manually
+generate_datasets-generate_datasets.$(OBJEXT): benchmarks.pb.h
+
+$(benchmarks_protoc_outputs): protoc_middleman
+$(benchmarks_protoc_outputs_proto2): protoc_middleman2
+
+CLEANFILES =                                                   \
+  $(benchmarks_protoc_outputs)                                 \
+  $(benchmarks_protoc_outputs_proto2)                          \
+  protoc_middleman                                             \
+  protoc_middleman2                                            \
+  dataset.*
+
+MAINTAINERCLEANFILES =   \
+  Makefile.in
+
+if USE_EXTERNAL_PROTOC
+
+protoc_middleman: $(benchmarks_protoc_inputs)
+	$(PROTOC) -I$(srcdir) -I$(top_srcdir) --cpp_out=. $(benchmarks_protoc_inputs)
+	touch protoc_middleman
+
+protoc_middleman2: $(benchmarks_protoc_inputs_proto2)
+	$(PROTOC) -I$(srcdir) -I$(top_srcdir) --cpp_out=. $(benchmarks_protoc_inputs_proto2)
+	touch protoc_middleman2
+
+else
+
+# We have to cd to $(srcdir) before executing protoc because $(protoc_inputs) is
+# relative to srcdir, which may not be the same as the current directory when
+# building out-of-tree.
+protoc_middleman: $(top_srcdir)/src/protoc$(EXEEXT) $(benchmarks_protoc_inputs) $(well_known_type_protoc_inputs)
+	oldpwd=`pwd` && ( cd $(srcdir) && $$oldpwd/../src/protoc$(EXEEXT) -I. -I$(top_srcdir)/src --cpp_out=$$oldpwd $(benchmarks_protoc_inputs) )
+	touch protoc_middleman
+
+protoc_middleman2: $(top_srcdir)/src/protoc$(EXEEXT) $(benchmarks_protoc_inputs_proto2) $(well_known_type_protoc_inputs)
+	oldpwd=`pwd` && ( cd $(srcdir) && $$oldpwd/../src/protoc$(EXEEXT) -I. -I$(top_srcdir)/src --cpp_out=$$oldpwd $(benchmarks_protoc_inputs_proto2) )
+	touch protoc_middleman
+
+endif

benchmarks/README.md

@@ -0,0 +1,28 @@
+
+# Protocol Buffers Benchmarks
+
+This directory contains benchmarking schemas and data sets that you
+can use to test a variety of performance scenarios against your
+protobuf language runtime.
+
+The schema for the datasets is described in `benchmarks.proto`.
+
+Generate the data sets like so:
+
+```
+$ make
+$ ./generate-datasets
+Wrote dataset: dataset.google_message1_proto3.pb
+Wrote dataset: dataset.google_message1_proto2.pb
+Wrote dataset: dataset.google_message2.pb
+$
+```
+
+Each data set will be written to its own file.  Benchmarks will
+likely want to run several benchmarks against each data set (parse,
+serialize, possibly JSON, possibly using different APIs, etc).
+
+We would like to add more data sets.  In general we will favor data sets
+that make the overall suite diverse without being too large or having
+too many similar tests.  Ideally everyone can run through the entire
+suite without the test run getting too long.

benchmarks/google_speed.proto → benchmarks/benchmark_messages_proto2.proto

@@ -1,11 +1,14 @@
+// Benchmark messages for proto2.
+
 syntax = "proto2";
 
-package benchmarks;
+package benchmarks.proto2;
+option java_package = "com.google.protobuf.benchmarks";
 
-option java_outer_classname = "GoogleSpeed";
+// This is the default, but we specify it here explicitly.
 option optimize_for = SPEED;
 
-message SpeedMessage1 {
+message GoogleMessage1 {
   required string field1 = 1;
   optional string field9 = 9;
   optional string field18 = 18;
@@ -40,7 +43,7 @@ message SpeedMessage1 {
   optional int32 field23 = 23 [default=0];
   optional bool field24 = 24 [default=false];
   optional int32 field25 = 25 [default=0];
-  optional SpeedMessage1SubMessage field15 = 15;
+  optional GoogleMessage1SubMessage field15 = 15;
   optional bool field78 = 78;
   optional int32 field67 = 67 [default=0];
   optional int32 field68 = 68;
@@ -49,7 +52,7 @@ message SpeedMessage1 {
   optional int32 field131 = 131 [default=0];
 }
 
-message SpeedMessage1SubMessage {
+message GoogleMessage1SubMessage {
   optional int32 field1 = 1 [default=0];
   optional int32 field2 = 2 [default=0];
   optional int32 field3 = 3 [default=0];
@@ -72,7 +75,7 @@ message SpeedMessage1SubMessage {
   optional uint64 field300 = 300;
 }
 
-message SpeedMessage2 {
+message GoogleMessage2 {
   optional string field1 = 1;
   optional int64 field3 = 3;
   optional int64 field4 = 4;
@@ -112,7 +115,7 @@ message SpeedMessage2 {
     repeated int32 field73 = 73;
     optional int32 field20 = 20 [default=0];
     optional string field24 = 24;
-    optional SpeedMessage2GroupedMessage field31 = 31;
+    optional GoogleMessage2GroupedMessage field31 = 31;
   }
   repeated string field128 = 128;
   optional int64 field131 = 131;
@@ -123,7 +126,7 @@ message SpeedMessage2 {
   optional bool field206 = 206 [default=false];
 }
 
-message SpeedMessage2GroupedMessage {
+message GoogleMessage2GroupedMessage {
   optional float field1 = 1;
   optional float field2 = 2;
   optional float field3 = 3 [default=0.0];

benchmarks/benchmark_messages_proto3.proto

@@ -0,0 +1,76 @@
+// Benchmark messages for proto3.
+
+syntax = "proto3";
+
+package benchmarks.proto3;
+option java_package = "com.google.protobuf.benchmarks";
+
+// This is the default, but we specify it here explicitly.
+option optimize_for = SPEED;
+
+message GoogleMessage1 {
+  string field1 = 1;
+  string field9 = 9;
+  string field18 = 18;
+  bool field80 = 80;
+  bool field81 = 81;
+  int32 field2 = 2;
+  int32 field3 = 3;
+  int32 field280 = 280;
+  int32 field6 = 6;
+  int64 field22 = 22;
+  string field4 = 4;
+  repeated fixed64 field5 = 5;
+  bool field59 = 59;
+  string field7 = 7;
+  int32 field16 = 16;
+  int32 field130 = 130;
+  bool field12 = 12;
+  bool field17 = 17;
+  bool field13 = 13;
+  bool field14 = 14;
+  int32 field104 = 104;
+  int32 field100 = 100;
+  int32 field101 = 101;
+  string field102 = 102;
+  string field103 = 103;
+  int32 field29 = 29;
+  bool field30 = 30;
+  int32 field60 = 60;
+  int32 field271 = 271;
+  int32 field272 = 272;
+  int32 field150 = 150;
+  int32 field23 = 23;
+  bool field24 = 24;
+  int32 field25 = 25;
+  GoogleMessage1SubMessage field15 = 15;
+  bool field78 = 78;
+  int32 field67 = 67;
+  int32 field68 = 68;
+  int32 field128 = 128;
+  string field129 = 129;
+  int32 field131 = 131;
+}
+
+message GoogleMessage1SubMessage {
+  int32 field1 = 1;
+  int32 field2 = 2;
+  int32 field3 = 3;
+  string field15 = 15;
+  bool field12 = 12;
+  int64 field13 = 13;
+  int64 field14 = 14;
+  int32 field16 = 16;
+  int32 field19 = 19;
+  bool field20  = 20;
+  bool field28 = 28;
+  fixed64 field21 = 21;
+  int32 field22 = 22;
+  bool field23 = 23;
+  bool field206 = 206;
+  fixed32 field203 = 203;
+  int32 field204 = 204;
+  string field205 = 205;
+  uint64 field207 = 207;
+  uint64 field300 = 300;
+}

benchmarks/benchmarks.proto

@@ -0,0 +1,63 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+syntax = "proto3";
+package benchmarks;
+option java_package = "com.google.protobuf.benchmarks";
+
+message BenchmarkDataset {
+  // Name of the benchmark dataset.  This should be unique across all datasets.
+  // Should only contain word characters: [a-zA-Z0-9_]
+  string name = 1;
+
+  // Fully-qualified name of the protobuf message for this dataset.
+  // It will be one of the messages defined benchmark_messages_proto2.proto
+  // or benchmark_messages_proto3.proto.
+  //
+  // Implementations that do not support reflection can implement this with
+  // an explicit "if/else" chain that lists every known message defined
+  // in those files.
+  string message_name = 2;
+
+  // The payload(s) for this dataset.  They should be parsed or serialized
+  // in sequence, in a loop, ie.
+  //
+  //  while (!benchmarkDone) {  // Benchmark runner decides when to exit.
+  //    for (i = 0; i < benchmark.payload.length; i++) {
+  //      parse(benchmark.payload[i])
+  //    }
+  //  }
+  //
+  // This is intended to let datasets include a variety of data to provide
+  // potentially more realistic results than just parsing the same message
+  // over and over.  A single message parsed repeatedly could yield unusually
+  // good branch prediction performance.
+  repeated bytes payload = 3;
+}

benchmarks/generate_datasets.cc

@@ -0,0 +1,117 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <fstream>
+#include <iostream>
+#include "benchmarks.pb.h"
+
+using benchmarks::BenchmarkDataset;
+using google::protobuf::Descriptor;
+using google::protobuf::DescriptorPool;
+using google::protobuf::Message;
+using google::protobuf::MessageFactory;
+
+std::set<std::string> names;
+
+const char *file_prefix = "dataset.";
+const char *file_suffix = ".pb";
+
+void WriteFileWithPayloads(const std::string& name,
+                           const std::string& message_name,
+                           const std::vector<std::string>& payload) {
+  if (!names.insert(name).second) {
+    std::cerr << "Duplicate test name: " << name << "\n";
+    abort();
+  }
+
+  // First verify that this message name exists in our set of benchmark messages
+  // and that these payloads are valid for the given message.
+  const Descriptor* d =
+      DescriptorPool::generated_pool()->FindMessageTypeByName(message_name);
+
+  if (!d) {
+    std::cerr << "For dataset " << name << ", no such message: "
+              << message_name << "\n";
+    abort();
+  }
+
+  Message* m = MessageFactory::generated_factory()->GetPrototype(d)->New();
+
+  for (size_t i = 0; i < payload.size(); i++) {
+    if (!m->ParseFromString(payload[i])) {
+      std::cerr << "For dataset " << name << ", payload[" << i << "] fails "
+                << "to parse\n";
+      abort();
+    }
+  }
+
+  BenchmarkDataset dataset;
+  dataset.set_name(name);
+  dataset.set_message_name(message_name);
+  for (size_t i = 0; i < payload.size(); i++) {
+    dataset.add_payload()->assign(payload[i]);
+  }
+
+  std::ofstream writer;
+  std::string fname = file_prefix + name + file_suffix;
+  writer.open(fname.c_str());
+  dataset.SerializeToOstream(&writer);
+  writer.close();
+
+  std::cerr << "Wrote dataset: " << fname << "\n";
+}
+
+void WriteFile(const std::string& name, const std::string& message_name,
+               const std::string& payload) {
+  std::vector<std::string> payloads;
+  payloads.push_back(payload);
+  WriteFileWithPayloads(name, message_name, payloads);
+}
+
+std::string ReadFile(const std::string& name) {
+  std::ifstream file(name.c_str());
+  GOOGLE_CHECK(file.is_open()) << "Couldn't find file '" << name <<
+                                  "', please make sure you are running "
+                                  "this command from the benchmarks/ "
+                                  "directory.\n";
+  return std::string((std::istreambuf_iterator<char>(file)),
+                     std::istreambuf_iterator<char>());
+}
+
+int main() {
+  WriteFile("google_message1_proto3", "benchmarks.proto3.GoogleMessage1",
+            ReadFile("google_message1.dat"));
+  WriteFile("google_message1_proto2", "benchmarks.proto2.GoogleMessage1",
+            ReadFile("google_message1.dat"));
+
+  // Not in proto3 because it has a group, which is not supported.
+  WriteFile("google_message2", "benchmarks.proto2.GoogleMessage2",
+            ReadFile("google_message2.dat"));
+}

cmake/CMakeLists.txt

@@ -118,6 +118,8 @@ if (MSVC)
   # Build with multiple processes
   add_definitions(/MP)
   add_definitions(/wd4244 /wd4267 /wd4018 /wd4355 /wd4800 /wd4251 /wd4996 /wd4146 /wd4305)
+  # Allow big object
+  add_definitions(/bigobj)
   string(REPLACE "/" "\\" PROTOBUF_SOURCE_WIN32_PATH ${protobuf_SOURCE_DIR})
   string(REPLACE "/" "\\" PROTOBUF_BINARY_WIN32_PATH ${protobuf_BINARY_DIR})
   configure_file(extract_includes.bat.in extract_includes.bat)

cmake/tests.cmake

@@ -52,6 +52,8 @@ set(tests_protos
   google/protobuf/unittest_preserve_unknown_enum.proto
   google/protobuf/unittest_preserve_unknown_enum2.proto
   google/protobuf/unittest_proto3_arena.proto
+  google/protobuf/unittest_proto3_arena_lite.proto
+  google/protobuf/unittest_proto3_lite.proto
   google/protobuf/unittest_well_known_types.proto
   google/protobuf/util/internal/testdata/anys.proto
   google/protobuf/util/internal/testdata/books.proto
@@ -116,6 +118,7 @@ set(tests_files
   ${protobuf_source_dir}/src/google/protobuf/compiler/cpp/cpp_bootstrap_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/compiler/cpp/cpp_plugin_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/compiler/cpp/cpp_unittest.cc
+  ${protobuf_source_dir}/src/google/protobuf/compiler/cpp/metadata_test.cc
   ${protobuf_source_dir}/src/google/protobuf/compiler/csharp/csharp_generator_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/compiler/importer_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/compiler/java/java_doc_comment_unittest.cc
@@ -140,7 +143,9 @@ set(tests_files
   ${protobuf_source_dir}/src/google/protobuf/message_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/no_field_presence_test.cc
   ${protobuf_source_dir}/src/google/protobuf/preserve_unknown_enum_test.cc
+  ${protobuf_source_dir}/src/google/protobuf/proto3_arena_lite_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/proto3_arena_unittest.cc
+  ${protobuf_source_dir}/src/google/protobuf/proto3_lite_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/reflection_ops_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/repeated_field_reflection_unittest.cc
   ${protobuf_source_dir}/src/google/protobuf/repeated_field_unittest.cc

configure.ac

@@ -180,5 +180,5 @@ export CFLAGS
 export CXXFLAGS
 AC_CONFIG_SUBDIRS([gmock])
 
-AC_CONFIG_FILES([Makefile src/Makefile conformance/Makefile protobuf.pc protobuf-lite.pc])
+AC_CONFIG_FILES([Makefile src/Makefile benchmarks/Makefile conformance/Makefile protobuf.pc protobuf-lite.pc])
 AC_OUTPUT

conformance/ConformanceJava.java

@@ -129,7 +129,7 @@ class ConformanceJava {
     typeRegistry = TypeRegistry.newBuilder().add(
         Conformance.TestAllTypes.getDescriptor()).build();
     while (doTestIo()) {
-      // Empty.
+      this.testCount++;
     }
 
     System.err.println("ConformanceJava: received EOF from test runner after " +

conformance/ConformanceJavaLite.java

@@ -0,0 +1,125 @@
+
+import com.google.protobuf.conformance.Conformance;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+class ConformanceJavaLite {
+  private int testCount = 0;
+
+  private boolean readFromStdin(byte[] buf, int len) throws Exception {
+    int ofs = 0;
+    while (len > 0) {
+      int read = System.in.read(buf, ofs, len);
+      if (read == -1) {
+        return false;  // EOF
+      }
+      ofs += read;
+      len -= read;
+    }
+
+    return true;
+  }
+
+  private void writeToStdout(byte[] buf) throws Exception {
+    System.out.write(buf);
+  }
+
+  // Returns -1 on EOF (the actual values will always be positive).
+  private int readLittleEndianIntFromStdin() throws Exception {
+    byte[] buf = new byte[4];
+    if (!readFromStdin(buf, 4)) {
+      return -1;
+    }
+    return (buf[0] & 0xff)
+        | ((buf[1] & 0xff) << 8)
+        | ((buf[2] & 0xff) << 16)
+        | ((buf[3] & 0xff) << 24);
+  }
+
+  private void writeLittleEndianIntToStdout(int val) throws Exception {
+    byte[] buf = new byte[4];
+    buf[0] = (byte)val;
+    buf[1] = (byte)(val >> 8);
+    buf[2] = (byte)(val >> 16);
+    buf[3] = (byte)(val >> 24);
+    writeToStdout(buf);
+  }
+
+  private Conformance.ConformanceResponse doTest(Conformance.ConformanceRequest request) {
+    Conformance.TestAllTypes testMessage;
+
+    switch (request.getPayloadCase()) {
+      case PROTOBUF_PAYLOAD: {
+        try {
+          testMessage = Conformance.TestAllTypes.parseFrom(request.getProtobufPayload());
+        } catch (InvalidProtocolBufferException e) {
+          return Conformance.ConformanceResponse.newBuilder().setParseError(e.getMessage()).build();
+        }
+        break;
+      }
+      case JSON_PAYLOAD: {
+        return Conformance.ConformanceResponse.newBuilder().setSkipped(
+            "Lite runtime does not suport Json Formant.").build();
+      }
+      case PAYLOAD_NOT_SET: {
+        throw new RuntimeException("Request didn't have payload.");
+      }
+
+      default: {
+        throw new RuntimeException("Unexpected payload case.");
+      }
+    }
+
+    switch (request.getRequestedOutputFormat()) {
+      case UNSPECIFIED:
+        throw new RuntimeException("Unspecified output format.");
+
+      case PROTOBUF:
+        return Conformance.ConformanceResponse.newBuilder().setProtobufPayload(testMessage.toByteString()).build();
+
+      case JSON:
+        return Conformance.ConformanceResponse.newBuilder().setSkipped(
+            "Lite runtime does not suport Json Formant.").build();
+
+      default: {
+        throw new RuntimeException("Unexpected request output.");
+      }
+    }
+  }
+
+  private boolean doTestIo() throws Exception {
+    int bytes = readLittleEndianIntFromStdin();
+
+    if (bytes == -1) {
+      return false;  // EOF
+    }
+
+    byte[] serializedInput = new byte[bytes];
+
+    if (!readFromStdin(serializedInput, bytes)) {
+      throw new RuntimeException("Unexpected EOF from test program.");
+    }
+
+    Conformance.ConformanceRequest request =
+        Conformance.ConformanceRequest.parseFrom(serializedInput);
+    Conformance.ConformanceResponse response = doTest(request);
+    byte[] serializedOutput = response.toByteArray();
+
+    writeLittleEndianIntToStdout(serializedOutput.length);
+    writeToStdout(serializedOutput);
+
+    return true;
+  }
+
+  public void run() throws Exception {
+    while (doTestIo()) {
+      this.testCount++;
+    }
+
+    System.err.println("ConformanceJavaLite: received EOF from test runner after " +
+        this.testCount + " tests");
+  }
+
+  public static void main(String[] args) throws Exception {
+    new ConformanceJavaLite().run();
+  }
+}

conformance/Makefile.am

@@ -17,11 +17,114 @@ protoc_outputs =                                               \
   conformance.pb.h
 
 other_language_protoc_outputs =                                \
-  conformance.rb                                               \
-  com/google/protobuf/conformance/Conformance.java             \
   conformance_pb2.py                                           \
   Conformance.pbobjc.h                                         \
-  Conformance.pbobjc.m
+  Conformance.pbobjc.m                                         \
+  conformance.rb                                               \
+  com/google/protobuf/Any.java                                 \
+  com/google/protobuf/AnyOrBuilder.java                        \
+  com/google/protobuf/AnyProto.java                            \
+  com/google/protobuf/BoolValue.java                           \
+  com/google/protobuf/BoolValueOrBuilder.java                  \
+  com/google/protobuf/BytesValue.java                          \
+  com/google/protobuf/BytesValueOrBuilder.java                 \
+  com/google/protobuf/conformance/Conformance.java             \
+  com/google/protobuf/DoubleValue.java                         \
+  com/google/protobuf/DoubleValueOrBuilder.java                \
+  com/google/protobuf/Duration.java                            \
+  com/google/protobuf/DurationOrBuilder.java                   \
+  com/google/protobuf/DurationProto.java                       \
+  com/google/protobuf/FieldMask.java                           \
+  com/google/protobuf/FieldMaskOrBuilder.java                  \
+  com/google/protobuf/FieldMaskProto.java                      \
+  com/google/protobuf/FloatValue.java                          \
+  com/google/protobuf/FloatValueOrBuilder.java                 \
+  com/google/protobuf/Int32Value.java                          \
+  com/google/protobuf/Int32ValueOrBuilder.java                 \
+  com/google/protobuf/Int64Value.java                          \
+  com/google/protobuf/Int64ValueOrBuilder.java                 \
+  com/google/protobuf/ListValue.java                           \
+  com/google/protobuf/ListValueOrBuilder.java                  \
+  com/google/protobuf/NullValue.java                           \
+  com/google/protobuf/StringValue.java                         \
+  com/google/protobuf/StringValueOrBuilder.java                \
+  com/google/protobuf/Struct.java                              \
+  com/google/protobuf/StructOrBuilder.java                     \
+  com/google/protobuf/StructProto.java                         \
+  com/google/protobuf/Timestamp.java                           \
+  com/google/protobuf/TimestampOrBuilder.java                  \
+  com/google/protobuf/TimestampProto.java                      \
+  com/google/protobuf/UInt32Value.java                         \
+  com/google/protobuf/UInt32ValueOrBuilder.java                \
+  com/google/protobuf/UInt64Value.java                         \
+  com/google/protobuf/UInt64ValueOrBuilder.java                \
+  com/google/protobuf/Value.java                               \
+  com/google/protobuf/ValueOrBuilder.java                      \
+  com/google/protobuf/WrappersProto.java                       \
+  google/protobuf/any.pb.cc                                    \
+  google/protobuf/any.pb.h                                     \
+  google/protobuf/any.rb                                       \
+  google/protobuf/any_pb2.py                                   \
+  google/protobuf/duration.pb.cc                               \
+  google/protobuf/duration.pb.h                                \
+  google/protobuf/duration.rb                                  \
+  google/protobuf/duration_pb2.py                              \
+  google/protobuf/field_mask.pb.cc                             \
+  google/protobuf/field_mask.pb.h                              \
+  google/protobuf/field_mask.rb                                \
+  google/protobuf/field_mask_pb2.py                            \
+  google/protobuf/struct.pb.cc                                 \
+  google/protobuf/struct.pb.h                                  \
+  google/protobuf/struct.rb                                    \
+  google/protobuf/struct_pb2.py                                \
+  google/protobuf/timestamp.pb.cc                              \
+  google/protobuf/timestamp.pb.h                               \
+  google/protobuf/timestamp.rb                                 \
+  google/protobuf/timestamp_pb2.py                             \
+  google/protobuf/wrappers.pb.cc                               \
+  google/protobuf/wrappers.pb.h                                \
+  google/protobuf/wrappers.rb                                  \
+  google/protobuf/wrappers_pb2.py                              \
+  lite/com/google/protobuf/Any.java                            \
+  lite/com/google/protobuf/AnyOrBuilder.java                   \
+  lite/com/google/protobuf/AnyProto.java                       \
+  lite/com/google/protobuf/BoolValue.java                      \
+  lite/com/google/protobuf/BoolValueOrBuilder.java             \
+  lite/com/google/protobuf/BytesValue.java                     \
+  lite/com/google/protobuf/BytesValueOrBuilder.java            \
+  lite/com/google/protobuf/conformance/Conformance.java        \
+  lite/com/google/protobuf/DoubleValue.java                    \
+  lite/com/google/protobuf/DoubleValueOrBuilder.java           \
+  lite/com/google/protobuf/Duration.java                       \
+  lite/com/google/protobuf/DurationOrBuilder.java              \
+  lite/com/google/protobuf/DurationProto.java                  \
+  lite/com/google/protobuf/FieldMask.java                      \
+  lite/com/google/protobuf/FieldMaskOrBuilder.java             \
+  lite/com/google/protobuf/FieldMaskProto.java                 \
+  lite/com/google/protobuf/FloatValue.java                     \
+  lite/com/google/protobuf/FloatValueOrBuilder.java            \
+  lite/com/google/protobuf/Int32Value.java                     \
+  lite/com/google/protobuf/Int32ValueOrBuilder.java            \
+  lite/com/google/protobuf/Int64Value.java                     \
+  lite/com/google/protobuf/Int64ValueOrBuilder.java            \
+  lite/com/google/protobuf/ListValue.java                      \
+  lite/com/google/protobuf/ListValueOrBuilder.java             \
+  lite/com/google/protobuf/NullValue.java                      \
+  lite/com/google/protobuf/StringValue.java                    \
+  lite/com/google/protobuf/StringValueOrBuilder.java           \
+  lite/com/google/protobuf/Struct.java                         \
+  lite/com/google/protobuf/StructOrBuilder.java                \
+  lite/com/google/protobuf/StructProto.java                    \
+  lite/com/google/protobuf/Timestamp.java                      \
+  lite/com/google/protobuf/TimestampOrBuilder.java             \
+  lite/com/google/protobuf/TimestampProto.java                 \
+  lite/com/google/protobuf/UInt32Value.java                    \
+  lite/com/google/protobuf/UInt32ValueOrBuilder.java           \
+  lite/com/google/protobuf/UInt64Value.java                    \
+  lite/com/google/protobuf/UInt64ValueOrBuilder.java           \
+  lite/com/google/protobuf/Value.java                          \
+  lite/com/google/protobuf/ValueOrBuilder.java                 \
+  lite/com/google/protobuf/WrappersProto.java
 
 bin_PROGRAMS = conformance-test-runner conformance-cpp
 
@@ -30,6 +133,7 @@ bin_PROGRAMS = conformance-test-runner conformance-cpp
 # automatically.
 EXTRA_DIST =                  \
   ConformanceJava.java        \
+  ConformanceJavaLite.java    \
   README.md                   \
   conformance.proto           \
   conformance_python.py       \
@@ -88,6 +192,7 @@ if USE_EXTERNAL_PROTOC
 protoc_middleman: $(conformance_protoc_inputs) $(well_known_type_protoc_inputs)
 	$(PROTOC) -I$(srcdir) -I$(top_srcdir) --cpp_out=. --java_out=. --ruby_out=. --objc_out=. --python_out=. $(conformance_protoc_inputs)
 	$(PROTOC) -I$(srcdir) -I$(top_srcdir) --cpp_out=. --java_out=. --ruby_out=. --python_out=. $(well_known_type_protoc_inputs)
+	$(PROTOC) -I$(srcdir) -I$(top_srcdir) --java_out=lite:lite $(conformance_protoc_inputs) $(well_known_type_protoc_inputs)
 	touch protoc_middleman
 
 else
@@ -98,6 +203,8 @@ else
 protoc_middleman: $(top_srcdir)/src/protoc$(EXEEXT) $(conformance_protoc_inputs) $(well_known_type_protoc_inputs)
 	oldpwd=`pwd` && ( cd $(srcdir) && $$oldpwd/../src/protoc$(EXEEXT) -I. -I$(top_srcdir)/src --cpp_out=$$oldpwd --java_out=$$oldpwd --ruby_out=$$oldpwd --objc_out=$$oldpwd --python_out=$$oldpwd $(conformance_protoc_inputs) )
 	oldpwd=`pwd` && ( cd $(srcdir) && $$oldpwd/../src/protoc$(EXEEXT) -I. -I$(top_srcdir)/src --cpp_out=$$oldpwd --java_out=$$oldpwd --ruby_out=$$oldpwd --python_out=$$oldpwd $(well_known_type_protoc_inputs) )
+	@mkdir -p lite
+	oldpwd=`pwd` && ( cd $(srcdir) && $$oldpwd/../src/protoc$(EXEEXT) -I. -I$(top_srcdir)/src --java_out=lite:$$oldpwd/lite $(conformance_protoc_inputs) $(well_known_type_protoc_inputs) )
 	touch protoc_middleman
 
 endif
@@ -108,7 +215,7 @@ $(other_language_protoc_outputs): protoc_middleman
 
 BUILT_SOURCES = $(protoc_outputs) $(other_language_protoc_outputs)
 
-CLEANFILES = $(protoc_outputs) protoc_middleman javac_middleman conformance-java conformance-csharp $(other_language_protoc_outputs)
+CLEANFILES = $(protoc_outputs) protoc_middleman javac_middleman conformance-java javac_middleman_lite conformance-java-lite conformance-csharp $(other_language_protoc_outputs)
 
 MAINTAINERCLEANFILES =   \
   Makefile.in
@@ -123,6 +230,16 @@ conformance-java: javac_middleman
 	@jar=`ls ../java/util/target/*jar-with-dependencies.jar` && echo java -classpath .:../java/target/classes:$$jar ConformanceJava '$$@' >> conformance-java
 	@chmod +x conformance-java
 
+javac_middleman_lite: ConformanceJavaLite.java protoc_middleman $(other_language_protoc_outputs)
+	javac -classpath ../java/lite/target/classes:lite ConformanceJavaLite.java lite/com/google/protobuf/conformance/Conformance.java
+	@touch javac_middleman_lite
+
+conformance-java-lite: javac_middleman_lite
+	@echo "Writing shortcut script conformance-java-lite..."
+	@echo '#! /bin/sh' > conformance-java-lite
+	@echo java -classpath .:../java/lite/target/classes:lite ConformanceJavaLite '$$@' >> conformance-java-lite
+	@chmod +x conformance-java-lite
+
 # Currently the conformance code is alongside the rest of the C#
 # source, as it's easier to maintain there. We assume we've already
 # built that, so we just need a script to run it.
@@ -139,6 +256,9 @@ test_cpp: protoc_middleman conformance-test-runner conformance-cpp
 test_java: protoc_middleman conformance-test-runner conformance-java
 	./conformance-test-runner --failure_list failure_list_java.txt ./conformance-java
 
+test_java_lite: protoc_middleman conformance-test-runner conformance-java-lite
+	./conformance-test-runner ./conformance-java-lite
+
 test_csharp: protoc_middleman conformance-test-runner conformance-csharp
 	./conformance-test-runner --failure_list failure_list_csharp.txt ./conformance-csharp
 

conformance/failure_list_ruby.txt

@@ -80,7 +80,6 @@ JsonInput.Int32FieldMaxFloatValue.JsonOutput
 JsonInput.Int32FieldMaxFloatValue.ProtobufOutput
 JsonInput.Int32FieldMinFloatValue.JsonOutput
 JsonInput.Int32FieldMinFloatValue.ProtobufOutput
-JsonInput.Int32FieldMinValue.JsonOutput
 JsonInput.Int32FieldStringValue.JsonOutput
 JsonInput.Int32FieldStringValue.ProtobufOutput
 JsonInput.Int32FieldStringValueEscaped.JsonOutput
@@ -125,7 +124,6 @@ JsonInput.OptionalUint64Wrapper.ProtobufOutput
 JsonInput.OptionalWrapperTypesWithNonDefaultValue.JsonOutput
 JsonInput.OptionalWrapperTypesWithNonDefaultValue.ProtobufOutput
 JsonInput.OriginalProtoFieldName.JsonOutput
-JsonInput.OriginalProtoFieldName.ProtobufOutput
 JsonInput.PrimitiveRepeatedField.JsonOutput
 JsonInput.PrimitiveRepeatedField.ProtobufOutput
 JsonInput.RepeatedBoolWrapper.JsonOutput

csharp/Google.Protobuf.Tools.nuspec

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="utf-8"?>
+<package>
+  <metadata>
+    <id>Google.Protobuf.Tools</id>
+    <title>Google Protocol Buffers tools</title>
+    <summary>Tools for Protocol Buffers - Google's data interchange format.</summary>
+    <description>See project site for more info.</description>
+    <version>3.0.0-beta2</version>
+    <authors>Google Inc.</authors>
+    <owners>protobuf-packages</owners>
+    <licenseUrl>https://github.com/google/protobuf/blob/master/LICENSE</licenseUrl>
+    <projectUrl>https://github.com/google/protobuf</projectUrl>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <releaseNotes>Tools for Protocol Buffers</releaseNotes>
+    <copyright>Copyright 2015, Google Inc.</copyright>
+    <tags>Protocol Buffers Binary Serialization Format Google proto proto3</tags>
+  </metadata>
+  <files>
+    <file src="protoc\windows_x86\protoc.exe" target="tools\windows_x86\protoc.exe" />
+    <file src="protoc\windows_x64\protoc.exe" target="tools\windows_x64\protoc.exe" />
+    <file src="protoc\linux_x86\protoc" target="tools\linux_x86\protoc" />
+    <file src="protoc\linux_x64\protoc" target="tools\linux_x64\protoc" />
+    <file src="protoc\macosx_x86\protoc" target="tools\macosx_x86\protoc" />
+    <file src="protoc\macosx_x64\protoc" target="tools\macosx_x64\protoc" />
+    <file src="..\src\google\protobuf\any.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\api.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\descriptor.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\duration.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\empty.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\field_mask.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\source_context.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\struct.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\timestamp.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\type.proto" target="tools\google\protobuf" />
+    <file src="..\src\google\protobuf\wrappers.proto" target="tools\google\protobuf" />
+  </files>
+</package>

csharp/protos/unittest_issues.proto

@@ -116,4 +116,11 @@ message TestJsonFieldOrdering {
     string o2_string = 3;
   }
   
-}
+}
+
+message TestJsonName {
+  // Message for testing the effects for of the json_name option
+  string name = 1;
+  string description = 2 [json_name = "desc"];
+  string guid = 3 [json_name = "exid"];
+}

csharp/src/AddressBook/AddPerson.cs

@@ -73,13 +73,13 @@ namespace Google.Protobuf.Examples.AddressBook
                 switch (type)
                 {
                     case "mobile":
-                        phoneNumber.Type = Person.Types.PhoneType.MOBILE;
+                        phoneNumber.Type = Person.Types.PhoneType.Mobile;
                         break;
                     case "home":
-                        phoneNumber.Type = Person.Types.PhoneType.HOME;
+                        phoneNumber.Type = Person.Types.PhoneType.Home;
                         break;
                     case "work":
-                        phoneNumber.Type = Person.Types.PhoneType.WORK;
+                        phoneNumber.Type = Person.Types.PhoneType.Work;
                         break;
                     default:
                         output.Write("Unknown phone type. Using default.");

csharp/src/AddressBook/Addressbook.cs

@@ -228,9 +228,9 @@ namespace Google.Protobuf.Examples.AddressBook {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     public static partial class Types {
       public enum PhoneType {
-        MOBILE = 0,
-        HOME = 1,
-        WORK = 2,
+        [pbr::OriginalName("MOBILE")] Mobile = 0,
+        [pbr::OriginalName("HOME")] Home = 1,
+        [pbr::OriginalName("WORK")] Work = 2,
       }
 
       [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
@@ -273,7 +273,7 @@ namespace Google.Protobuf.Examples.AddressBook {
 
         /// <summary>Field number for the "type" field.</summary>
         public const int TypeFieldNumber = 2;
-        private global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType type_ = global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE;
+        private global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType type_ = 0;
         public global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType Type {
           get { return type_; }
           set {
@@ -300,7 +300,7 @@ namespace Google.Protobuf.Examples.AddressBook {
         public override int GetHashCode() {
           int hash = 1;
           if (Number.Length != 0) hash ^= Number.GetHashCode();
-          if (Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) hash ^= Type.GetHashCode();
+          if (Type != 0) hash ^= Type.GetHashCode();
           return hash;
         }
 
@@ -313,7 +313,7 @@ namespace Google.Protobuf.Examples.AddressBook {
             output.WriteRawTag(10);
             output.WriteString(Number);
           }
-          if (Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) {
+          if (Type != 0) {
             output.WriteRawTag(16);
             output.WriteEnum((int) Type);
           }
@@ -324,7 +324,7 @@ namespace Google.Protobuf.Examples.AddressBook {
           if (Number.Length != 0) {
             size += 1 + pb::CodedOutputStream.ComputeStringSize(Number);
           }
-          if (Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) {
+          if (Type != 0) {
             size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Type);
           }
           return size;
@@ -337,7 +337,7 @@ namespace Google.Protobuf.Examples.AddressBook {
           if (other.Number.Length != 0) {
             Number = other.Number;
           }
-          if (other.Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) {
+          if (other.Type != 0) {
             Type = other.Type;
           }
         }

csharp/src/AddressBook/ListPeople.cs

@@ -55,13 +55,13 @@ namespace Google.Protobuf.Examples.AddressBook
                 {
                     switch (phoneNumber.Type)
                     {
-                        case Person.Types.PhoneType.MOBILE:
+                        case Person.Types.PhoneType.Mobile:
                             Console.Write("  Mobile phone #: ");
                             break;
-                        case Person.Types.PhoneType.HOME:
+                        case Person.Types.PhoneType.Home:
                             Console.Write("  Home phone #: ");
                             break;
-                        case Person.Types.PhoneType.WORK:
+                        case Person.Types.PhoneType.Work:
                             Console.Write("  Work phone #: ");
                             break;
                     }

csharp/src/Google.Protobuf.Conformance/Conformance.cs

@@ -199,15 +199,15 @@ namespace Conformance {
   }
   #region Enums
   public enum WireFormat {
-    UNSPECIFIED = 0,
-    PROTOBUF = 1,
-    JSON = 2,
+    [pbr::OriginalName("UNSPECIFIED")] Unspecified = 0,
+    [pbr::OriginalName("PROTOBUF")] Protobuf = 1,
+    [pbr::OriginalName("JSON")] Json = 2,
   }
 
   public enum ForeignEnum {
-    FOREIGN_FOO = 0,
-    FOREIGN_BAR = 1,
-    FOREIGN_BAZ = 2,
+    [pbr::OriginalName("FOREIGN_FOO")] ForeignFoo = 0,
+    [pbr::OriginalName("FOREIGN_BAR")] ForeignBar = 1,
+    [pbr::OriginalName("FOREIGN_BAZ")] ForeignBaz = 2,
   }
 
   #endregion
@@ -278,7 +278,7 @@ namespace Conformance {
 
     /// <summary>Field number for the "requested_output_format" field.</summary>
     public const int RequestedOutputFormatFieldNumber = 3;
-    private global::Conformance.WireFormat requestedOutputFormat_ = global::Conformance.WireFormat.UNSPECIFIED;
+    private global::Conformance.WireFormat requestedOutputFormat_ = 0;
     /// <summary>
     ///  Which format should the testee serialize its message to?
     /// </summary>
@@ -328,7 +328,7 @@ namespace Conformance {
       int hash = 1;
       if (payloadCase_ == PayloadOneofCase.ProtobufPayload) hash ^= ProtobufPayload.GetHashCode();
       if (payloadCase_ == PayloadOneofCase.JsonPayload) hash ^= JsonPayload.GetHashCode();
-      if (RequestedOutputFormat != global::Conformance.WireFormat.UNSPECIFIED) hash ^= RequestedOutputFormat.GetHashCode();
+      if (RequestedOutputFormat != 0) hash ^= RequestedOutputFormat.GetHashCode();
       hash ^= (int) payloadCase_;
       return hash;
     }
@@ -346,7 +346,7 @@ namespace Conformance {
         output.WriteRawTag(18);
         output.WriteString(JsonPayload);
       }
-      if (RequestedOutputFormat != global::Conformance.WireFormat.UNSPECIFIED) {
+      if (RequestedOutputFormat != 0) {
         output.WriteRawTag(24);
         output.WriteEnum((int) RequestedOutputFormat);
       }
@@ -360,7 +360,7 @@ namespace Conformance {
       if (payloadCase_ == PayloadOneofCase.JsonPayload) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(JsonPayload);
       }
-      if (RequestedOutputFormat != global::Conformance.WireFormat.UNSPECIFIED) {
+      if (RequestedOutputFormat != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) RequestedOutputFormat);
       }
       return size;
@@ -370,7 +370,7 @@ namespace Conformance {
       if (other == null) {
         return;
       }
-      if (other.RequestedOutputFormat != global::Conformance.WireFormat.UNSPECIFIED) {
+      if (other.RequestedOutputFormat != 0) {
         RequestedOutputFormat = other.RequestedOutputFormat;
       }
       switch (other.PayloadCase) {
@@ -1044,7 +1044,7 @@ namespace Conformance {
 
     /// <summary>Field number for the "optional_nested_enum" field.</summary>
     public const int OptionalNestedEnumFieldNumber = 21;
-    private global::Conformance.TestAllTypes.Types.NestedEnum optionalNestedEnum_ = global::Conformance.TestAllTypes.Types.NestedEnum.FOO;
+    private global::Conformance.TestAllTypes.Types.NestedEnum optionalNestedEnum_ = 0;
     public global::Conformance.TestAllTypes.Types.NestedEnum OptionalNestedEnum {
       get { return optionalNestedEnum_; }
       set {
@@ -1054,7 +1054,7 @@ namespace Conformance {
 
     /// <summary>Field number for the "optional_foreign_enum" field.</summary>
     public const int OptionalForeignEnumFieldNumber = 22;
-    private global::Conformance.ForeignEnum optionalForeignEnum_ = global::Conformance.ForeignEnum.FOREIGN_FOO;
+    private global::Conformance.ForeignEnum optionalForeignEnum_ = 0;
     public global::Conformance.ForeignEnum OptionalForeignEnum {
       get { return optionalForeignEnum_; }
       set {
@@ -2079,8 +2079,8 @@ namespace Conformance {
       if (OptionalBytes.Length != 0) hash ^= OptionalBytes.GetHashCode();
       if (optionalNestedMessage_ != null) hash ^= OptionalNestedMessage.GetHashCode();
       if (optionalForeignMessage_ != null) hash ^= OptionalForeignMessage.GetHashCode();
-      if (OptionalNestedEnum != global::Conformance.TestAllTypes.Types.NestedEnum.FOO) hash ^= OptionalNestedEnum.GetHashCode();
-      if (OptionalForeignEnum != global::Conformance.ForeignEnum.FOREIGN_FOO) hash ^= OptionalForeignEnum.GetHashCode();
+      if (OptionalNestedEnum != 0) hash ^= OptionalNestedEnum.GetHashCode();
+      if (OptionalForeignEnum != 0) hash ^= OptionalForeignEnum.GetHashCode();
       if (OptionalStringPiece.Length != 0) hash ^= OptionalStringPiece.GetHashCode();
       if (OptionalCord.Length != 0) hash ^= OptionalCord.GetHashCode();
       if (recursiveMessage_ != null) hash ^= RecursiveMessage.GetHashCode();
@@ -2247,11 +2247,11 @@ namespace Conformance {
         output.WriteRawTag(154, 1);
         output.WriteMessage(OptionalForeignMessage);
       }
-      if (OptionalNestedEnum != global::Conformance.TestAllTypes.Types.NestedEnum.FOO) {
+      if (OptionalNestedEnum != 0) {
         output.WriteRawTag(168, 1);
         output.WriteEnum((int) OptionalNestedEnum);
       }
-      if (OptionalForeignEnum != global::Conformance.ForeignEnum.FOREIGN_FOO) {
+      if (OptionalForeignEnum != 0) {
         output.WriteRawTag(176, 1);
         output.WriteEnum((int) OptionalForeignEnum);
       }
@@ -2492,10 +2492,10 @@ namespace Conformance {
       if (optionalForeignMessage_ != null) {
         size += 2 + pb::CodedOutputStream.ComputeMessageSize(OptionalForeignMessage);
       }
-      if (OptionalNestedEnum != global::Conformance.TestAllTypes.Types.NestedEnum.FOO) {
+      if (OptionalNestedEnum != 0) {
         size += 2 + pb::CodedOutputStream.ComputeEnumSize((int) OptionalNestedEnum);
       }
-      if (OptionalForeignEnum != global::Conformance.ForeignEnum.FOREIGN_FOO) {
+      if (OptionalForeignEnum != 0) {
         size += 2 + pb::CodedOutputStream.ComputeEnumSize((int) OptionalForeignEnum);
       }
       if (OptionalStringPiece.Length != 0) {
@@ -2719,10 +2719,10 @@ namespace Conformance {
         }
         OptionalForeignMessage.MergeFrom(other.OptionalForeignMessage);
       }
-      if (other.OptionalNestedEnum != global::Conformance.TestAllTypes.Types.NestedEnum.FOO) {
+      if (other.OptionalNestedEnum != 0) {
         OptionalNestedEnum = other.OptionalNestedEnum;
       }
-      if (other.OptionalForeignEnum != global::Conformance.ForeignEnum.FOREIGN_FOO) {
+      if (other.OptionalForeignEnum != 0) {
         OptionalForeignEnum = other.OptionalForeignEnum;
       }
       if (other.OptionalStringPiece.Length != 0) {
@@ -3448,13 +3448,13 @@ namespace Conformance {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     public static partial class Types {
       public enum NestedEnum {
-        FOO = 0,
-        BAR = 1,
-        BAZ = 2,
+        [pbr::OriginalName("FOO")] Foo = 0,
+        [pbr::OriginalName("BAR")] Bar = 1,
+        [pbr::OriginalName("BAZ")] Baz = 2,
         /// <summary>
         ///  Intentionally negative.
         /// </summary>
-        NEG = -1,
+        [pbr::OriginalName("NEG")] Neg = -1,
       }
 
       [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

csharp/src/Google.Protobuf.Conformance/Program.cs

@@ -109,10 +109,10 @@ namespace Google.Protobuf.Conformance
             {
                 switch (request.RequestedOutputFormat)
                 {
-                    case global::Conformance.WireFormat.JSON:
+                    case global::Conformance.WireFormat.Json:
                         var formatter = new JsonFormatter(new JsonFormatter.Settings(false, typeRegistry));
                         return new ConformanceResponse { JsonPayload = formatter.Format(message) };
-                    case global::Conformance.WireFormat.PROTOBUF:
+                    case global::Conformance.WireFormat.Protobuf:
                         return new ConformanceResponse { ProtobufPayload = message.ToByteString() };
                     default:
                         throw new Exception("Unsupported request output format: " + request.PayloadCase);

csharp/src/Google.Protobuf.Test/FieldCodecTest.cs

@@ -58,7 +58,7 @@ namespace Google.Protobuf
             new FieldCodecTestData<float>(FieldCodec.ForFloat(100), 1234.5f, "Float"),
             new FieldCodecTestData<double>(FieldCodec.ForDouble(100), 1234567890.5d, "Double"),
             new FieldCodecTestData<ForeignEnum>(
-                FieldCodec.ForEnum(100, t => (int) t, t => (ForeignEnum) t), ForeignEnum.FOREIGN_BAZ, "Enum"),
+                FieldCodec.ForEnum(100, t => (int) t, t => (ForeignEnum) t), ForeignEnum.ForeignBaz, "Enum"),
             new FieldCodecTestData<ForeignMessage>(
                 FieldCodec.ForMessage(100, ForeignMessage.Parser), new ForeignMessage { C = 10 }, "Message"),
         };

csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs

@@ -66,13 +66,13 @@ namespace Google.Protobuf
             Assert.AreEqual(0, message.SingleFixed32);
             Assert.AreEqual(0L, message.SingleFixed64);
             Assert.AreEqual(0.0f, message.SingleFloat);
-            Assert.AreEqual(ForeignEnum.FOREIGN_UNSPECIFIED, message.SingleForeignEnum);
+            Assert.AreEqual(ForeignEnum.ForeignUnspecified, message.SingleForeignEnum);
             Assert.IsNull(message.SingleForeignMessage);
-            Assert.AreEqual(ImportEnum.IMPORT_ENUM_UNSPECIFIED, message.SingleImportEnum);
+            Assert.AreEqual(ImportEnum.Unspecified, message.SingleImportEnum);
             Assert.IsNull(message.SingleImportMessage);
             Assert.AreEqual(0, message.SingleInt32);
             Assert.AreEqual(0L, message.SingleInt64);
-            Assert.AreEqual(TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED, message.SingleNestedEnum);
+            Assert.AreEqual(TestAllTypes.Types.NestedEnum.Unspecified, message.SingleNestedEnum);
             Assert.IsNull(message.SingleNestedMessage);
             Assert.IsNull(message.SinglePublicImportMessage);
             Assert.AreEqual(0, message.SingleSfixed32);
@@ -145,13 +145,13 @@ namespace Google.Protobuf
                 SingleFixed32 = 23,
                 SingleFixed64 = 1234567890123,
                 SingleFloat = 12.25f,
-                SingleForeignEnum = ForeignEnum.FOREIGN_BAR,
+                SingleForeignEnum = ForeignEnum.ForeignBar,
                 SingleForeignMessage = new ForeignMessage { C = 10 },
-                SingleImportEnum = ImportEnum.IMPORT_BAZ,
+                SingleImportEnum = ImportEnum.ImportBaz,
                 SingleImportMessage = new ImportMessage { D = 20 },
                 SingleInt32 = 100,
                 SingleInt64 = 3210987654321,
-                SingleNestedEnum = TestAllTypes.Types.NestedEnum.FOO,
+                SingleNestedEnum = TestAllTypes.Types.NestedEnum.Foo,
                 SingleNestedMessage = new TestAllTypes.Types.NestedMessage { Bb = 35 },
                 SinglePublicImportMessage = new PublicImportMessage { E = 54 },
                 SingleSfixed32 = -123,
@@ -179,13 +179,13 @@ namespace Google.Protobuf
                 RepeatedFixed32 = { uint.MaxValue, 23 },
                 RepeatedFixed64 = { ulong.MaxValue, 1234567890123 },
                 RepeatedFloat = { 100f, 12.25f },
-                RepeatedForeignEnum = { ForeignEnum.FOREIGN_FOO, ForeignEnum.FOREIGN_BAR },
+                RepeatedForeignEnum = { ForeignEnum.ForeignFoo, ForeignEnum.ForeignBar },
                 RepeatedForeignMessage = { new ForeignMessage(), new ForeignMessage { C = 10 } },
-                RepeatedImportEnum = { ImportEnum.IMPORT_BAZ, ImportEnum.IMPORT_ENUM_UNSPECIFIED },
+                RepeatedImportEnum = { ImportEnum.ImportBaz, ImportEnum.Unspecified },
                 RepeatedImportMessage = { new ImportMessage { D = 20 }, new ImportMessage { D = 25 } },
                 RepeatedInt32 = { 100, 200 },
                 RepeatedInt64 = { 3210987654321, long.MaxValue },
-                RepeatedNestedEnum = { TestAllTypes.Types.NestedEnum.FOO, TestAllTypes.Types.NestedEnum.NEG },
+                RepeatedNestedEnum = { TestAllTypes.Types.NestedEnum.Foo, TestAllTypes.Types.NestedEnum.Neg },
                 RepeatedNestedMessage = { new TestAllTypes.Types.NestedMessage { Bb = 35 }, new TestAllTypes.Types.NestedMessage { Bb = 10 } },
                 RepeatedPublicImportMessage = { new PublicImportMessage { E = 54 }, new PublicImportMessage { E = -1 } },
                 RepeatedSfixed32 = { -123, 123 },
@@ -224,8 +224,8 @@ namespace Google.Protobuf
                     { 5, new ForeignMessage() },
                 },
                 MapInt32Enum = {
-                    { 1, MapEnum.MAP_ENUM_BAR },
-                    { 2000, MapEnum.MAP_ENUM_FOO }
+                    { 1, MapEnum.Bar },
+                    { 2000, MapEnum.Foo }
                 }
             };
 
@@ -249,7 +249,7 @@ namespace Google.Protobuf
             Assert.AreEqual(1, parsed.MapInt32Bytes.Count);
             Assert.AreEqual(ByteString.Empty, parsed.MapInt32Bytes[0]);
         }
-        
+
         [Test]
         public void MapWithOnlyValue()
         {
@@ -449,7 +449,7 @@ namespace Google.Protobuf
                 SingleFloat = 12.25f,
                 SingleInt32 = 100,
                 SingleInt64 = 3210987654321,
-                SingleNestedEnum = TestAllTypes.Types.NestedEnum.FOO,
+                SingleNestedEnum = TestAllTypes.Types.NestedEnum.Foo,
                 SingleSfixed32 = -123,
                 SingleSfixed64 = -12345678901234,
                 SingleSint32 = -456,
@@ -479,7 +479,7 @@ namespace Google.Protobuf
                 RepeatedFloat = { 100f, 12.25f },
                 RepeatedInt32 = { 100, 200 },
                 RepeatedInt64 = { 3210987654321, long.MaxValue },
-                RepeatedNestedEnum = { TestAllTypes.Types.NestedEnum.FOO, TestAllTypes.Types.NestedEnum.NEG },
+                RepeatedNestedEnum = { TestAllTypes.Types.NestedEnum.Foo, TestAllTypes.Types.NestedEnum.Neg },
                 RepeatedSfixed32 = { -123, 123 },
                 RepeatedSfixed64 = { -12345678901234, 12345678901234 },
                 RepeatedSint32 = { -456, 100 },
@@ -670,7 +670,7 @@ namespace Google.Protobuf
         {
             // 130, 3 is the message tag
             // 1 is the data length - but there's no data.
-            var data = new byte[] { 130, 3, 1 };            
+            var data = new byte[] { 130, 3, 1 };
             Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseFrom(data));
         }
 
@@ -720,4 +720,4 @@ namespace Google.Protobuf
             Assert.AreEqual("{ \"c\": 31 }", writer.ToString());
         }
     }
-}
+}

csharp/src/Google.Protobuf.Test/IssuesTest.cs

@@ -59,5 +59,24 @@ namespace Google.Protobuf
             // Underscores aren't reflected in the JSON.
             Assert.AreEqual("{ \"types\": 10, \"descriptor\": 20 }", message.ToString());
         }
+
+        [Test]
+        public void JsonNameParseTest()
+        {
+            var settings = new JsonParser.Settings(10, TypeRegistry.FromFiles(UnittestIssuesReflection.Descriptor));
+            var parser = new JsonParser(settings);
+
+            // It is safe to use either original field name or explicitly specified json_name
+            Assert.AreEqual(new TestJsonName { Name = "test", Description = "test2", Guid = "test3" },
+                parser.Parse<TestJsonName>("{ \"name\": \"test\", \"desc\": \"test2\", \"guid\": \"test3\" }"));
+        }
+
+        [Test]
+        public void JsonNameFormatTest()
+        {
+            var message = new TestJsonName { Name = "test", Description = "test2", Guid = "test3" };
+            Assert.AreEqual("{ \"name\": \"test\", \"desc\": \"test2\", \"exid\": \"test3\" }",
+                JsonFormatter.Default.Format(message));
+        }
     }
 }

csharp/src/Google.Protobuf.Test/JsonFormatterTest.cs

@@ -75,13 +75,13 @@ namespace Google.Protobuf
                 SingleFixed32 = 23,
                 SingleFixed64 = 1234567890123,
                 SingleFloat = 12.25f,
-                SingleForeignEnum = ForeignEnum.FOREIGN_BAR,
+                SingleForeignEnum = ForeignEnum.ForeignBar,
                 SingleForeignMessage = new ForeignMessage { C = 10 },
-                SingleImportEnum = ImportEnum.IMPORT_BAZ,
+                SingleImportEnum = ImportEnum.ImportBaz,
                 SingleImportMessage = new ImportMessage { D = 20 },
                 SingleInt32 = 100,
                 SingleInt64 = 3210987654321,
-                SingleNestedEnum = TestAllTypes.Types.NestedEnum.FOO,
+                SingleNestedEnum = TestAllTypes.Types.NestedEnum.Foo,
                 SingleNestedMessage = new TestAllTypes.Types.NestedMessage { Bb = 35 },
                 SinglePublicImportMessage = new PublicImportMessage { E = 54 },
                 SingleSfixed32 = -123,
@@ -174,14 +174,14 @@ namespace Google.Protobuf
         [Test]
         public void UnknownEnumValueNumeric_RepeatedField()
         {
-            var message = new TestAllTypes { RepeatedForeignEnum = { ForeignEnum.FOREIGN_BAZ, (ForeignEnum) 100, ForeignEnum.FOREIGN_FOO } };
+            var message = new TestAllTypes { RepeatedForeignEnum = { ForeignEnum.ForeignBaz, (ForeignEnum) 100, ForeignEnum.ForeignFoo } };
             AssertJson("{ 'repeatedForeignEnum': [ 'FOREIGN_BAZ', 100, 'FOREIGN_FOO' ] }", JsonFormatter.Default.Format(message));
         }
 
         [Test]
         public void UnknownEnumValueNumeric_MapField()
         {
-            var message = new TestMap { MapInt32Enum = { { 1, MapEnum.MAP_ENUM_FOO }, { 2, (MapEnum) 100 }, { 3, MapEnum.MAP_ENUM_BAR } } };
+            var message = new TestMap { MapInt32Enum = { { 1, MapEnum.Foo }, { 2, (MapEnum) 100 }, { 3, MapEnum.Bar } } };
             AssertJson("{ 'mapInt32Enum': { '1': 'MAP_ENUM_FOO', '2': 100, '3': 'MAP_ENUM_BAR' } }", JsonFormatter.Default.Format(message));
         }
 
@@ -321,7 +321,6 @@ namespace Google.Protobuf
         [TestCase("1970-01-01T00:00:00.001Z", 1000000)]
         [TestCase("1970-01-01T00:00:00.010Z", 10000000)]
         [TestCase("1970-01-01T00:00:00.100Z", 100000000)]
-        [TestCase("1970-01-01T00:00:00.100Z", 100000000)]
         [TestCase("1970-01-01T00:00:00.120Z", 120000000)]
         [TestCase("1970-01-01T00:00:00.123Z", 123000000)]
         [TestCase("1970-01-01T00:00:00.123400Z", 123400000)]
@@ -481,6 +480,15 @@ namespace Google.Protobuf
             AssertJson("{ '@type': 'type.googleapis.com/protobuf_unittest.TestAllTypes', 'singleInt32': 10, 'singleNestedMessage': { 'bb': 20 } }", formatter.Format(any));
         }
 
+        [Test]
+        public void AnyMessageType_CustomPrefix()
+        {
+            var formatter = new JsonFormatter(new JsonFormatter.Settings(false, TypeRegistry.FromMessages(TestAllTypes.Descriptor)));
+            var message = new TestAllTypes { SingleInt32 = 10 };
+            var any = Any.Pack(message, "foo.bar/baz");
+            AssertJson("{ '@type': 'foo.bar/baz/protobuf_unittest.TestAllTypes', 'singleInt32': 10 }", formatter.Format(any));
+        }
+
         [Test]
         public void AnyNested()
         {

csharp/src/Google.Protobuf.Test/JsonParserTest.cs

@@ -142,8 +142,8 @@ namespace Google.Protobuf
         [TestCase(typeof(DoubleValue), "1.5", 1.5d)]
         public void Wrappers_Standalone(System.Type wrapperType, string json, object expectedValue)
         {
-            IMessage parsed = (IMessage) Activator.CreateInstance(wrapperType);
-            IMessage expected = (IMessage) Activator.CreateInstance(wrapperType);
+            IMessage parsed = (IMessage)Activator.CreateInstance(wrapperType);
+            IMessage expected = (IMessage)Activator.CreateInstance(wrapperType);
             JsonParser.Default.Merge(parsed, "null");
             Assert.AreEqual(expected, parsed);
 
@@ -640,7 +640,7 @@ namespace Google.Protobuf
             var parsed = Timestamp.Parser.ParseJson(json);
             Assert.AreEqual(WrapInQuotes(expectedFormatted), parsed.ToString());
         }
-        
+
         [Test]
         [TestCase("2015-10-09 14:46:23.123456789Z", Description = "No T between date and time")]
         [TestCase("2015/10/09T14:46:23.123456789Z", Description = "Wrong date separators")]
@@ -810,6 +810,17 @@ namespace Google.Protobuf
             Assert.AreEqual(original, parser.Parse<Any>(valueFirstJson));
         }
 
+        [Test]
+        public void Any_CustomPrefix()
+        {
+            var registry = TypeRegistry.FromMessages(TestAllTypes.Descriptor);
+            var message = new TestAllTypes { SingleInt32 = 10 };
+            var original = Any.Pack(message, "custom.prefix/middle-part");
+            var parser = new JsonParser(new JsonParser.Settings(10, registry));
+            string json = "{ \"@type\": \"custom.prefix/middle-part/protobuf_unittest.TestAllTypes\", \"singleInt32\": 10 }";
+            Assert.AreEqual(original, parser.Parse<Any>(json));
+        }
+
         [Test]
         public void Any_UnknownType()
         {
@@ -886,9 +897,9 @@ namespace Google.Protobuf
         }
 
         [Test]
-        [TestCase("\"FOREIGN_BAR\"", ForeignEnum.FOREIGN_BAR)]
-        [TestCase("5", ForeignEnum.FOREIGN_BAR)]
-        [TestCase("100", (ForeignEnum) 100)]
+        [TestCase("\"FOREIGN_BAR\"", ForeignEnum.ForeignBar)]
+        [TestCase("5", ForeignEnum.ForeignBar)]
+        [TestCase("100", (ForeignEnum)100)]
         public void EnumValid(string value, ForeignEnum expectedValue)
         {
             string json = "{ \"singleForeignEnum\": " + value + " }";
@@ -922,4 +933,4 @@ namespace Google.Protobuf
             return '"' + text + '"';
         }
     }
-}
+}

csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs

@@ -249,7 +249,6 @@ namespace Google.Protobuf
         [TestCase("[,", 1)]
         [TestCase("{", 1)]
         [TestCase("{,", 1)]
-        [TestCase("{", 1)]
         [TestCase("{[", 1)]
         [TestCase("{{", 1)]
         [TestCase("{0", 1)]

csharp/src/Google.Protobuf.Test/Reflection/DescriptorsTest.cs

@@ -195,7 +195,7 @@ namespace Google.Protobuf.Reflection
             Assert.AreEqual(value, enumType.Values[1]);
             Assert.AreEqual("FOREIGN_FOO", value.Name);
             Assert.AreEqual(4, value.Number);
-            Assert.AreEqual((int) ForeignEnum.FOREIGN_FOO, value.Number);
+            Assert.AreEqual((int) ForeignEnum.ForeignFoo, value.Number);
             Assert.AreEqual(value, enumType.FindValueByNumber(4));
             Assert.Null(enumType.FindValueByName("NO_SUCH_VALUE"));
             for (int i = 0; i < enumType.Values.Count; i++)

csharp/src/Google.Protobuf.Test/Reflection/FieldAccessTest.cs

@@ -128,7 +128,7 @@ namespace Google.Protobuf.Reflection
             fields[TestAllTypes.SingleInt32FieldNumber].Accessor.SetValue(message, 500);
             fields[TestAllTypes.SingleStringFieldNumber].Accessor.SetValue(message, "It's a string");
             fields[TestAllTypes.SingleBytesFieldNumber].Accessor.SetValue(message, ByteString.CopyFrom(99, 98, 97));
-            fields[TestAllTypes.SingleForeignEnumFieldNumber].Accessor.SetValue(message, ForeignEnum.FOREIGN_FOO);
+            fields[TestAllTypes.SingleForeignEnumFieldNumber].Accessor.SetValue(message, ForeignEnum.ForeignFoo);
             fields[TestAllTypes.SingleForeignMessageFieldNumber].Accessor.SetValue(message, new ForeignMessage { C = 12345 });
             fields[TestAllTypes.SingleDoubleFieldNumber].Accessor.SetValue(message, 20150701.5);
 
@@ -138,7 +138,7 @@ namespace Google.Protobuf.Reflection
                 SingleInt32 = 500,
                 SingleString = "It's a string",
                 SingleBytes = ByteString.CopyFrom(99, 98, 97),
-                SingleForeignEnum = ForeignEnum.FOREIGN_FOO,
+                SingleForeignEnum = ForeignEnum.ForeignFoo,
                 SingleForeignMessage = new ForeignMessage { C = 12345 },
                 SingleDouble = 20150701.5
             };

csharp/src/Google.Protobuf.Test/SampleMessages.cs

@@ -54,13 +54,13 @@ namespace Google.Protobuf
                 SingleFixed32 = 23,
                 SingleFixed64 = 1234567890123,
                 SingleFloat = 12.25f,
-                SingleForeignEnum = ForeignEnum.FOREIGN_BAR,
+                SingleForeignEnum = ForeignEnum.ForeignBar,
                 SingleForeignMessage = new ForeignMessage { C = 10 },
-                SingleImportEnum = ImportEnum.IMPORT_BAZ,
+                SingleImportEnum = ImportEnum.ImportBaz,
                 SingleImportMessage = new ImportMessage { D = 20 },
                 SingleInt32 = 100,
                 SingleInt64 = 3210987654321,
-                SingleNestedEnum = TestAllTypes.Types.NestedEnum.FOO,
+                SingleNestedEnum = TestAllTypes.Types.NestedEnum.Foo,
                 SingleNestedMessage = new TestAllTypes.Types.NestedMessage { Bb = 35 },
                 SinglePublicImportMessage = new PublicImportMessage { E = 54 },
                 SingleSfixed32 = -123,
@@ -76,13 +76,13 @@ namespace Google.Protobuf
                 RepeatedFixed32 = { UInt32.MaxValue, 23 },
                 RepeatedFixed64 = { UInt64.MaxValue, 1234567890123 },
                 RepeatedFloat = { 100f, 12.25f },
-                RepeatedForeignEnum = { ForeignEnum.FOREIGN_FOO, ForeignEnum.FOREIGN_BAR },
+                RepeatedForeignEnum = { ForeignEnum.ForeignFoo, ForeignEnum.ForeignBar },
                 RepeatedForeignMessage = { new ForeignMessage(), new ForeignMessage { C = 10 } },
-                RepeatedImportEnum = { ImportEnum.IMPORT_BAZ, ImportEnum.IMPORT_ENUM_UNSPECIFIED },
+                RepeatedImportEnum = { ImportEnum.ImportBaz, ImportEnum.Unspecified },
                 RepeatedImportMessage = { new ImportMessage { D = 20 }, new ImportMessage { D = 25 } },
                 RepeatedInt32 = { 100, 200 },
                 RepeatedInt64 = { 3210987654321, Int64.MaxValue },
-                RepeatedNestedEnum = { TestAllTypes.Types.NestedEnum.FOO, TestAllTypes.Types.NestedEnum.NEG },
+                RepeatedNestedEnum = { TestAllTypes.Types.NestedEnum.Foo, TestAllTypes.Types.NestedEnum.Neg },
                 RepeatedNestedMessage = { new TestAllTypes.Types.NestedMessage { Bb = 35 }, new TestAllTypes.Types.NestedMessage { Bb = 10 } },
                 RepeatedPublicImportMessage = { new PublicImportMessage { E = 54 }, new PublicImportMessage { E = -1 } },
                 RepeatedSfixed32 = { -123, 123 },
@@ -92,8 +92,8 @@ namespace Google.Protobuf
                 RepeatedString = { "foo", "bar" },
                 RepeatedUint32 = { UInt32.MaxValue, UInt32.MinValue },
                 RepeatedUint64 = { UInt64.MaxValue, UInt32.MinValue },
-                OneofString = "Oneof string"                
+                OneofString = "Oneof string"
             };
         }
     }
-}
+}

csharp/src/Google.Protobuf.Test/TestCornerCases.cs

@@ -43,8 +43,8 @@ namespace Google.Protobuf
             NegativeEnumMessage msg = new NegativeEnumMessage
             {
                 Value = NegativeEnum.MinusOne,
-                Values = { NegativeEnum.NEGATIVE_ENUM_ZERO, NegativeEnum.MinusOne, NegativeEnum.FiveBelow },
-                PackedValues = { NegativeEnum.NEGATIVE_ENUM_ZERO, NegativeEnum.MinusOne, NegativeEnum.FiveBelow }
+                Values = { NegativeEnum.Zero, NegativeEnum.MinusOne, NegativeEnum.FiveBelow },
+                PackedValues = { NegativeEnum.Zero, NegativeEnum.MinusOne, NegativeEnum.FiveBelow }
             };
 
             Assert.AreEqual(58, msg.CalculateSize());

csharp/src/Google.Protobuf.Test/TestProtos/MapUnittestProto3.cs

@@ -164,9 +164,9 @@ namespace Google.Protobuf.TestProtos {
   }
   #region Enums
   public enum MapEnum {
-    MAP_ENUM_FOO = 0,
-    MAP_ENUM_BAR = 1,
-    MAP_ENUM_BAZ = 2,
+    [pbr::OriginalName("MAP_ENUM_FOO")] Foo = 0,
+    [pbr::OriginalName("MAP_ENUM_BAR")] Bar = 1,
+    [pbr::OriginalName("MAP_ENUM_BAZ")] Baz = 2,
   }
 
   #endregion
@@ -1358,7 +1358,7 @@ namespace Google.Protobuf.TestProtos {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     public static partial class Types {
       public enum Type {
-        TYPE_FOO = 0,
+        [pbr::OriginalName("TYPE_FOO")] Foo = 0,
       }
 
     }

csharp/src/Google.Protobuf.Test/TestProtos/UnittestImportProto3.cs

@@ -42,10 +42,10 @@ namespace Google.Protobuf.TestProtos {
   }
   #region Enums
   public enum ImportEnum {
-    IMPORT_ENUM_UNSPECIFIED = 0,
-    IMPORT_FOO = 7,
-    IMPORT_BAR = 8,
-    IMPORT_BAZ = 9,
+    [pbr::OriginalName("IMPORT_ENUM_UNSPECIFIED")] Unspecified = 0,
+    [pbr::OriginalName("IMPORT_FOO")] ImportFoo = 7,
+    [pbr::OriginalName("IMPORT_BAR")] ImportBar = 8,
+    [pbr::OriginalName("IMPORT_BAZ")] ImportBaz = 9,
   }
 
   #endregion

csharp/src/Google.Protobuf.Test/TestProtos/UnittestIssues.cs

@@ -42,10 +42,12 @@ namespace UnitTest.Issues.TestProtos {
             "CgtwbGFpbl9pbnQzMhgEIAEoBRITCglvMV9zdHJpbmcYAiABKAlIABISCghv",
             "MV9pbnQzMhgFIAEoBUgAEhQKDHBsYWluX3N0cmluZxgBIAEoCRISCghvMl9p",
             "bnQzMhgGIAEoBUgBEhMKCW8yX3N0cmluZxgDIAEoCUgBQgQKAm8xQgQKAm8y",
-            "KlUKDE5lZ2F0aXZlRW51bRIWChJORUdBVElWRV9FTlVNX1pFUk8QABIWCglG",
-            "aXZlQmVsb3cQ+///////////ARIVCghNaW51c09uZRD///////////8BKi4K",
-            "DkRlcHJlY2F0ZWRFbnVtEhMKD0RFUFJFQ0FURURfWkVSTxAAEgcKA29uZRAB",
-            "Qh9IAaoCGlVuaXRUZXN0Lklzc3Vlcy5UZXN0UHJvdG9zYgZwcm90bzM="));
+            "IksKDFRlc3RKc29uTmFtZRIMCgRuYW1lGAEgASgJEhkKC2Rlc2NyaXB0aW9u",
+            "GAIgASgJUgRkZXNjEhIKBGd1aWQYAyABKAlSBGV4aWQqVQoMTmVnYXRpdmVF",
+            "bnVtEhYKEk5FR0FUSVZFX0VOVU1fWkVSTxAAEhYKCUZpdmVCZWxvdxD7////",
+            "//////8BEhUKCE1pbnVzT25lEP///////////wEqLgoORGVwcmVjYXRlZEVu",
+            "dW0SEwoPREVQUkVDQVRFRF9aRVJPEAASBwoDb25lEAFCH0gBqgIaVW5pdFRl",
+            "c3QuSXNzdWVzLlRlc3RQcm90b3NiBnByb3RvMw=="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(new[] {typeof(global::UnitTest.Issues.TestProtos.NegativeEnum), typeof(global::UnitTest.Issues.TestProtos.DeprecatedEnum), }, new pbr::GeneratedClrTypeInfo[] {
@@ -55,7 +57,8 @@ namespace UnitTest.Issues.TestProtos {
             new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.DeprecatedFieldsMessage), global::UnitTest.Issues.TestProtos.DeprecatedFieldsMessage.Parser, new[]{ "PrimitiveValue", "PrimitiveArray", "MessageValue", "MessageArray", "EnumValue", "EnumArray" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.ItemField), global::UnitTest.Issues.TestProtos.ItemField.Parser, new[]{ "Item" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.ReservedNames), global::UnitTest.Issues.TestProtos.ReservedNames.Parser, new[]{ "Types_", "Descriptor_" }, null, null, new pbr::GeneratedClrTypeInfo[] { new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.ReservedNames.Types.SomeNestedType), global::UnitTest.Issues.TestProtos.ReservedNames.Types.SomeNestedType.Parser, null, null, null, null)}),
-            new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.TestJsonFieldOrdering), global::UnitTest.Issues.TestProtos.TestJsonFieldOrdering.Parser, new[]{ "PlainInt32", "O1String", "O1Int32", "PlainString", "O2Int32", "O2String" }, new[]{ "O1", "O2" }, null, null)
+            new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.TestJsonFieldOrdering), global::UnitTest.Issues.TestProtos.TestJsonFieldOrdering.Parser, new[]{ "PlainInt32", "O1String", "O1Int32", "PlainString", "O2Int32", "O2String" }, new[]{ "O1", "O2" }, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.TestJsonName), global::UnitTest.Issues.TestProtos.TestJsonName.Parser, new[]{ "Name", "Description", "Guid" }, null, null, null)
           }));
     }
     #endregion
@@ -63,14 +66,14 @@ namespace UnitTest.Issues.TestProtos {
   }
   #region Enums
   public enum NegativeEnum {
-    NEGATIVE_ENUM_ZERO = 0,
-    FiveBelow = -5,
-    MinusOne = -1,
+    [pbr::OriginalName("NEGATIVE_ENUM_ZERO")] Zero = 0,
+    [pbr::OriginalName("FiveBelow")] FiveBelow = -5,
+    [pbr::OriginalName("MinusOne")] MinusOne = -1,
   }
 
   public enum DeprecatedEnum {
-    DEPRECATED_ZERO = 0,
-    one = 1,
+    [pbr::OriginalName("DEPRECATED_ZERO")] DeprecatedZero = 0,
+    [pbr::OriginalName("one")] One = 1,
   }
 
   #endregion
@@ -353,7 +356,7 @@ namespace UnitTest.Issues.TestProtos {
 
     /// <summary>Field number for the "value" field.</summary>
     public const int ValueFieldNumber = 1;
-    private global::UnitTest.Issues.TestProtos.NegativeEnum value_ = global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO;
+    private global::UnitTest.Issues.TestProtos.NegativeEnum value_ = 0;
     public global::UnitTest.Issues.TestProtos.NegativeEnum Value {
       get { return value_; }
       set {
@@ -398,7 +401,7 @@ namespace UnitTest.Issues.TestProtos {
 
     public override int GetHashCode() {
       int hash = 1;
-      if (Value != global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO) hash ^= Value.GetHashCode();
+      if (Value != 0) hash ^= Value.GetHashCode();
       hash ^= values_.GetHashCode();
       hash ^= packedValues_.GetHashCode();
       return hash;
@@ -409,7 +412,7 @@ namespace UnitTest.Issues.TestProtos {
     }
 
     public void WriteTo(pb::CodedOutputStream output) {
-      if (Value != global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO) {
+      if (Value != 0) {
         output.WriteRawTag(8);
         output.WriteEnum((int) Value);
       }
@@ -419,7 +422,7 @@ namespace UnitTest.Issues.TestProtos {
 
     public int CalculateSize() {
       int size = 0;
-      if (Value != global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO) {
+      if (Value != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Value);
       }
       size += values_.CalculateSize(_repeated_values_codec);
@@ -431,7 +434,7 @@ namespace UnitTest.Issues.TestProtos {
       if (other == null) {
         return;
       }
-      if (other.Value != global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO) {
+      if (other.Value != 0) {
         Value = other.Value;
       }
       values_.Add(other.values_);
@@ -617,7 +620,7 @@ namespace UnitTest.Issues.TestProtos {
 
     /// <summary>Field number for the "EnumValue" field.</summary>
     public const int EnumValueFieldNumber = 5;
-    private global::UnitTest.Issues.TestProtos.DeprecatedEnum enumValue_ = global::UnitTest.Issues.TestProtos.DeprecatedEnum.DEPRECATED_ZERO;
+    private global::UnitTest.Issues.TestProtos.DeprecatedEnum enumValue_ = 0;
     [global::System.ObsoleteAttribute()]
     public global::UnitTest.Issues.TestProtos.DeprecatedEnum EnumValue {
       get { return enumValue_; }
@@ -662,7 +665,7 @@ namespace UnitTest.Issues.TestProtos {
       hash ^= primitiveArray_.GetHashCode();
       if (messageValue_ != null) hash ^= MessageValue.GetHashCode();
       hash ^= messageArray_.GetHashCode();
-      if (EnumValue != global::UnitTest.Issues.TestProtos.DeprecatedEnum.DEPRECATED_ZERO) hash ^= EnumValue.GetHashCode();
+      if (EnumValue != 0) hash ^= EnumValue.GetHashCode();
       hash ^= enumArray_.GetHashCode();
       return hash;
     }
@@ -682,7 +685,7 @@ namespace UnitTest.Issues.TestProtos {
         output.WriteMessage(MessageValue);
       }
       messageArray_.WriteTo(output, _repeated_messageArray_codec);
-      if (EnumValue != global::UnitTest.Issues.TestProtos.DeprecatedEnum.DEPRECATED_ZERO) {
+      if (EnumValue != 0) {
         output.WriteRawTag(40);
         output.WriteEnum((int) EnumValue);
       }
@@ -699,7 +702,7 @@ namespace UnitTest.Issues.TestProtos {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(MessageValue);
       }
       size += messageArray_.CalculateSize(_repeated_messageArray_codec);
-      if (EnumValue != global::UnitTest.Issues.TestProtos.DeprecatedEnum.DEPRECATED_ZERO) {
+      if (EnumValue != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) EnumValue);
       }
       size += enumArray_.CalculateSize(_repeated_enumArray_codec);
@@ -721,7 +724,7 @@ namespace UnitTest.Issues.TestProtos {
         MessageValue.MergeFrom(other.MessageValue);
       }
       messageArray_.Add(other.messageArray_);
-      if (other.EnumValue != global::UnitTest.Issues.TestProtos.DeprecatedEnum.DEPRECATED_ZERO) {
+      if (other.EnumValue != 0) {
         EnumValue = other.EnumValue;
       }
       enumArray_.Add(other.enumArray_);
@@ -1399,6 +1402,166 @@ namespace UnitTest.Issues.TestProtos {
 
   }
 
+  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+  public sealed partial class TestJsonName : pb::IMessage<TestJsonName> {
+    private static readonly pb::MessageParser<TestJsonName> _parser = new pb::MessageParser<TestJsonName>(() => new TestJsonName());
+    public static pb::MessageParser<TestJsonName> Parser { get { return _parser; } }
+
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::UnitTest.Issues.TestProtos.UnittestIssuesReflection.Descriptor.MessageTypes[7]; }
+    }
+
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    public TestJsonName() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    public TestJsonName(TestJsonName other) : this() {
+      name_ = other.name_;
+      description_ = other.description_;
+      guid_ = other.guid_;
+    }
+
+    public TestJsonName Clone() {
+      return new TestJsonName(this);
+    }
+
+    /// <summary>Field number for the "name" field.</summary>
+    public const int NameFieldNumber = 1;
+    private string name_ = "";
+    /// <summary>
+    ///  Message for testing the effects for of the json_name option
+    /// </summary>
+    public string Name {
+      get { return name_; }
+      set {
+        name_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+      }
+    }
+
+    /// <summary>Field number for the "description" field.</summary>
+    public const int DescriptionFieldNumber = 2;
+    private string description_ = "";
+    public string Description {
+      get { return description_; }
+      set {
+        description_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+      }
+    }
+
+    /// <summary>Field number for the "guid" field.</summary>
+    public const int GuidFieldNumber = 3;
+    private string guid_ = "";
+    public string Guid {
+      get { return guid_; }
+      set {
+        guid_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+      }
+    }
+
+    public override bool Equals(object other) {
+      return Equals(other as TestJsonName);
+    }
+
+    public bool Equals(TestJsonName other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if (Name != other.Name) return false;
+      if (Description != other.Description) return false;
+      if (Guid != other.Guid) return false;
+      return true;
+    }
+
+    public override int GetHashCode() {
+      int hash = 1;
+      if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (Description.Length != 0) hash ^= Description.GetHashCode();
+      if (Guid.Length != 0) hash ^= Guid.GetHashCode();
+      return hash;
+    }
+
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    public void WriteTo(pb::CodedOutputStream output) {
+      if (Name.Length != 0) {
+        output.WriteRawTag(10);
+        output.WriteString(Name);
+      }
+      if (Description.Length != 0) {
+        output.WriteRawTag(18);
+        output.WriteString(Description);
+      }
+      if (Guid.Length != 0) {
+        output.WriteRawTag(26);
+        output.WriteString(Guid);
+      }
+    }
+
+    public int CalculateSize() {
+      int size = 0;
+      if (Name.Length != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
+      }
+      if (Description.Length != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeStringSize(Description);
+      }
+      if (Guid.Length != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeStringSize(Guid);
+      }
+      return size;
+    }
+
+    public void MergeFrom(TestJsonName other) {
+      if (other == null) {
+        return;
+      }
+      if (other.Name.Length != 0) {
+        Name = other.Name;
+      }
+      if (other.Description.Length != 0) {
+        Description = other.Description;
+      }
+      if (other.Guid.Length != 0) {
+        Guid = other.Guid;
+      }
+    }
+
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 10: {
+            Name = input.ReadString();
+            break;
+          }
+          case 18: {
+            Description = input.ReadString();
+            break;
+          }
+          case 26: {
+            Guid = input.ReadString();
+            break;
+          }
+        }
+      }
+    }
+
+  }
+
   #endregion
 
 }

csharp/src/Google.Protobuf.Test/TestProtos/UnittestProto3.cs

@@ -193,39 +193,39 @@ namespace Google.Protobuf.TestProtos {
   }
   #region Enums
   public enum ForeignEnum {
-    FOREIGN_UNSPECIFIED = 0,
-    FOREIGN_FOO = 4,
-    FOREIGN_BAR = 5,
-    FOREIGN_BAZ = 6,
+    [pbr::OriginalName("FOREIGN_UNSPECIFIED")] ForeignUnspecified = 0,
+    [pbr::OriginalName("FOREIGN_FOO")] ForeignFoo = 4,
+    [pbr::OriginalName("FOREIGN_BAR")] ForeignBar = 5,
+    [pbr::OriginalName("FOREIGN_BAZ")] ForeignBaz = 6,
   }
 
   /// <summary>
   ///  Test an enum that has multiple values with the same number.
   /// </summary>
   public enum TestEnumWithDupValue {
-    TEST_ENUM_WITH_DUP_VALUE_UNSPECIFIED = 0,
-    FOO1 = 1,
-    BAR1 = 2,
-    BAZ = 3,
-    FOO2 = 1,
-    BAR2 = 2,
+    [pbr::OriginalName("TEST_ENUM_WITH_DUP_VALUE_UNSPECIFIED")] Unspecified = 0,
+    [pbr::OriginalName("FOO1")] Foo1 = 1,
+    [pbr::OriginalName("BAR1")] Bar1 = 2,
+    [pbr::OriginalName("BAZ")] Baz = 3,
+    [pbr::OriginalName("FOO2")] Foo2 = 1,
+    [pbr::OriginalName("BAR2")] Bar2 = 2,
   }
 
   /// <summary>
   ///  Test an enum with large, unordered values.
   /// </summary>
   public enum TestSparseEnum {
-    TEST_SPARSE_ENUM_UNSPECIFIED = 0,
-    SPARSE_A = 123,
-    SPARSE_B = 62374,
-    SPARSE_C = 12589234,
-    SPARSE_D = -15,
-    SPARSE_E = -53452,
+    [pbr::OriginalName("TEST_SPARSE_ENUM_UNSPECIFIED")] Unspecified = 0,
+    [pbr::OriginalName("SPARSE_A")] SparseA = 123,
+    [pbr::OriginalName("SPARSE_B")] SparseB = 62374,
+    [pbr::OriginalName("SPARSE_C")] SparseC = 12589234,
+    [pbr::OriginalName("SPARSE_D")] SparseD = -15,
+    [pbr::OriginalName("SPARSE_E")] SparseE = -53452,
     /// <summary>
     ///  In proto3, value 0 must be the first one specified
     ///  SPARSE_F = 0;
     /// </summary>
-    SPARSE_G = 2,
+    [pbr::OriginalName("SPARSE_G")] SparseG = 2,
   }
 
   #endregion
@@ -505,7 +505,7 @@ namespace Google.Protobuf.TestProtos {
 
     /// <summary>Field number for the "single_nested_enum" field.</summary>
     public const int SingleNestedEnumFieldNumber = 21;
-    private global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum singleNestedEnum_ = global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED;
+    private global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum singleNestedEnum_ = 0;
     public global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum SingleNestedEnum {
       get { return singleNestedEnum_; }
       set {
@@ -515,7 +515,7 @@ namespace Google.Protobuf.TestProtos {
 
     /// <summary>Field number for the "single_foreign_enum" field.</summary>
     public const int SingleForeignEnumFieldNumber = 22;
-    private global::Google.Protobuf.TestProtos.ForeignEnum singleForeignEnum_ = global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED;
+    private global::Google.Protobuf.TestProtos.ForeignEnum singleForeignEnum_ = 0;
     public global::Google.Protobuf.TestProtos.ForeignEnum SingleForeignEnum {
       get { return singleForeignEnum_; }
       set {
@@ -525,7 +525,7 @@ namespace Google.Protobuf.TestProtos {
 
     /// <summary>Field number for the "single_import_enum" field.</summary>
     public const int SingleImportEnumFieldNumber = 23;
-    private global::Google.Protobuf.TestProtos.ImportEnum singleImportEnum_ = global::Google.Protobuf.TestProtos.ImportEnum.IMPORT_ENUM_UNSPECIFIED;
+    private global::Google.Protobuf.TestProtos.ImportEnum singleImportEnum_ = 0;
     public global::Google.Protobuf.TestProtos.ImportEnum SingleImportEnum {
       get { return singleImportEnum_; }
       set {
@@ -892,9 +892,9 @@ namespace Google.Protobuf.TestProtos {
       if (singleNestedMessage_ != null) hash ^= SingleNestedMessage.GetHashCode();
       if (singleForeignMessage_ != null) hash ^= SingleForeignMessage.GetHashCode();
       if (singleImportMessage_ != null) hash ^= SingleImportMessage.GetHashCode();
-      if (SingleNestedEnum != global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED) hash ^= SingleNestedEnum.GetHashCode();
-      if (SingleForeignEnum != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) hash ^= SingleForeignEnum.GetHashCode();
-      if (SingleImportEnum != global::Google.Protobuf.TestProtos.ImportEnum.IMPORT_ENUM_UNSPECIFIED) hash ^= SingleImportEnum.GetHashCode();
+      if (SingleNestedEnum != 0) hash ^= SingleNestedEnum.GetHashCode();
+      if (SingleForeignEnum != 0) hash ^= SingleForeignEnum.GetHashCode();
+      if (SingleImportEnum != 0) hash ^= SingleImportEnum.GetHashCode();
       if (singlePublicImportMessage_ != null) hash ^= SinglePublicImportMessage.GetHashCode();
       hash ^= repeatedInt32_.GetHashCode();
       hash ^= repeatedInt64_.GetHashCode();
@@ -1003,15 +1003,15 @@ namespace Google.Protobuf.TestProtos {
         output.WriteRawTag(162, 1);
         output.WriteMessage(SingleImportMessage);
       }
-      if (SingleNestedEnum != global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED) {
+      if (SingleNestedEnum != 0) {
         output.WriteRawTag(168, 1);
         output.WriteEnum((int) SingleNestedEnum);
       }
-      if (SingleForeignEnum != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) {
+      if (SingleForeignEnum != 0) {
         output.WriteRawTag(176, 1);
         output.WriteEnum((int) SingleForeignEnum);
       }
-      if (SingleImportEnum != global::Google.Protobuf.TestProtos.ImportEnum.IMPORT_ENUM_UNSPECIFIED) {
+      if (SingleImportEnum != 0) {
         output.WriteRawTag(184, 1);
         output.WriteEnum((int) SingleImportEnum);
       }
@@ -1115,13 +1115,13 @@ namespace Google.Protobuf.TestProtos {
       if (singleImportMessage_ != null) {
         size += 2 + pb::CodedOutputStream.ComputeMessageSize(SingleImportMessage);
       }
-      if (SingleNestedEnum != global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED) {
+      if (SingleNestedEnum != 0) {
         size += 2 + pb::CodedOutputStream.ComputeEnumSize((int) SingleNestedEnum);
       }
-      if (SingleForeignEnum != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) {
+      if (SingleForeignEnum != 0) {
         size += 2 + pb::CodedOutputStream.ComputeEnumSize((int) SingleForeignEnum);
       }
-      if (SingleImportEnum != global::Google.Protobuf.TestProtos.ImportEnum.IMPORT_ENUM_UNSPECIFIED) {
+      if (SingleImportEnum != 0) {
         size += 2 + pb::CodedOutputStream.ComputeEnumSize((int) SingleImportEnum);
       }
       if (singlePublicImportMessage_ != null) {
@@ -1231,13 +1231,13 @@ namespace Google.Protobuf.TestProtos {
         }
         SingleImportMessage.MergeFrom(other.SingleImportMessage);
       }
-      if (other.SingleNestedEnum != global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED) {
+      if (other.SingleNestedEnum != 0) {
         SingleNestedEnum = other.SingleNestedEnum;
       }
-      if (other.SingleForeignEnum != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) {
+      if (other.SingleForeignEnum != 0) {
         SingleForeignEnum = other.SingleForeignEnum;
       }
-      if (other.SingleImportEnum != global::Google.Protobuf.TestProtos.ImportEnum.IMPORT_ENUM_UNSPECIFIED) {
+      if (other.SingleImportEnum != 0) {
         SingleImportEnum = other.SingleImportEnum;
       }
       if (other.singlePublicImportMessage_ != null) {
@@ -1526,14 +1526,14 @@ namespace Google.Protobuf.TestProtos {
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     public static partial class Types {
       public enum NestedEnum {
-        NESTED_ENUM_UNSPECIFIED = 0,
-        FOO = 1,
-        BAR = 2,
-        BAZ = 3,
+        [pbr::OriginalName("NESTED_ENUM_UNSPECIFIED")] Unspecified = 0,
+        [pbr::OriginalName("FOO")] Foo = 1,
+        [pbr::OriginalName("BAR")] Bar = 2,
+        [pbr::OriginalName("BAZ")] Baz = 3,
         /// <summary>
         ///  Intentionally negative.
         /// </summary>
-        NEG = -1,
+        [pbr::OriginalName("NEG")] Neg = -1,
       }
 
       [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
@@ -2793,7 +2793,7 @@ namespace Google.Protobuf.TestProtos {
 
     /// <summary>Field number for the "EnumField" field.</summary>
     public const int EnumFieldFieldNumber = 3;
-    private global::Google.Protobuf.TestProtos.ForeignEnum enumField_ = global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED;
+    private global::Google.Protobuf.TestProtos.ForeignEnum enumField_ = 0;
     public global::Google.Protobuf.TestProtos.ForeignEnum EnumField {
       get { return enumField_; }
       set {
@@ -2873,7 +2873,7 @@ namespace Google.Protobuf.TestProtos {
       int hash = 1;
       if (PrimitiveField != 0) hash ^= PrimitiveField.GetHashCode();
       if (StringField.Length != 0) hash ^= StringField.GetHashCode();
-      if (EnumField != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) hash ^= EnumField.GetHashCode();
+      if (EnumField != 0) hash ^= EnumField.GetHashCode();
       if (messageField_ != null) hash ^= MessageField.GetHashCode();
       hash ^= repeatedPrimitiveField_.GetHashCode();
       hash ^= repeatedStringField_.GetHashCode();
@@ -2895,7 +2895,7 @@ namespace Google.Protobuf.TestProtos {
         output.WriteRawTag(18);
         output.WriteString(StringField);
       }
-      if (EnumField != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) {
+      if (EnumField != 0) {
         output.WriteRawTag(24);
         output.WriteEnum((int) EnumField);
       }
@@ -2917,7 +2917,7 @@ namespace Google.Protobuf.TestProtos {
       if (StringField.Length != 0) {
         size += 1 + pb::CodedOutputStream.ComputeStringSize(StringField);
       }
-      if (EnumField != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) {
+      if (EnumField != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) EnumField);
       }
       if (messageField_ != null) {
@@ -2940,7 +2940,7 @@ namespace Google.Protobuf.TestProtos {
       if (other.StringField.Length != 0) {
         StringField = other.StringField;
       }
-      if (other.EnumField != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) {
+      if (other.EnumField != 0) {
         EnumField = other.EnumField;
       }
       if (other.messageField_ != null) {
@@ -3370,7 +3370,7 @@ namespace Google.Protobuf.TestProtos {
 
     /// <summary>Field number for the "sparse_enum" field.</summary>
     public const int SparseEnumFieldNumber = 1;
-    private global::Google.Protobuf.TestProtos.TestSparseEnum sparseEnum_ = global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED;
+    private global::Google.Protobuf.TestProtos.TestSparseEnum sparseEnum_ = 0;
     public global::Google.Protobuf.TestProtos.TestSparseEnum SparseEnum {
       get { return sparseEnum_; }
       set {
@@ -3395,7 +3395,7 @@ namespace Google.Protobuf.TestProtos {
 
     public override int GetHashCode() {
       int hash = 1;
-      if (SparseEnum != global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED) hash ^= SparseEnum.GetHashCode();
+      if (SparseEnum != 0) hash ^= SparseEnum.GetHashCode();
       return hash;
     }
 
@@ -3404,7 +3404,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public void WriteTo(pb::CodedOutputStream output) {
-      if (SparseEnum != global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED) {
+      if (SparseEnum != 0) {
         output.WriteRawTag(8);
         output.WriteEnum((int) SparseEnum);
       }
@@ -3412,7 +3412,7 @@ namespace Google.Protobuf.TestProtos {
 
     public int CalculateSize() {
       int size = 0;
-      if (SparseEnum != global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED) {
+      if (SparseEnum != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) SparseEnum);
       }
       return size;
@@ -3422,7 +3422,7 @@ namespace Google.Protobuf.TestProtos {
       if (other == null) {
         return;
       }
-      if (other.SparseEnum != global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED) {
+      if (other.SparseEnum != 0) {
         SparseEnum = other.SparseEnum;
       }
     }

csharp/src/Google.Protobuf.Test/WellKnownTypes/AnyTest.cs

@@ -46,6 +46,24 @@ namespace Google.Protobuf.WellKnownTypes
             Assert.AreEqual(message.CalculateSize(), any.Value.Length);
         }
 
+        [Test]
+        public void Pack_WithCustomPrefix()
+        {
+            var message = SampleMessages.CreateFullTestAllTypes();
+            var any = Any.Pack(message, "foo.bar/baz");
+            Assert.AreEqual("foo.bar/baz/protobuf_unittest.TestAllTypes", any.TypeUrl);
+            Assert.AreEqual(message.CalculateSize(), any.Value.Length);
+        }
+
+        [Test]
+        public void Pack_WithCustomPrefixTrailingSlash()
+        {
+            var message = SampleMessages.CreateFullTestAllTypes();
+            var any = Any.Pack(message, "foo.bar/baz/");
+            Assert.AreEqual("foo.bar/baz/protobuf_unittest.TestAllTypes", any.TypeUrl);
+            Assert.AreEqual(message.CalculateSize(), any.Value.Length);
+        }
+
         [Test]
         public void Unpack_WrongType()
         {
@@ -63,6 +81,15 @@ namespace Google.Protobuf.WellKnownTypes
             Assert.AreEqual(message, unpacked);
         }
 
+        [Test]
+        public void Unpack_CustomPrefix_Success()
+        {
+            var message = SampleMessages.CreateFullTestAllTypes();
+            var any = Any.Pack(message, "foo.bar/baz");
+            var unpacked = any.Unpack<TestAllTypes>();
+            Assert.AreEqual(message, unpacked);
+        }
+
         [Test]
         public void ToString_WithValues()
         {

csharp/src/Google.Protobuf/Google.Protobuf.csproj

@@ -117,6 +117,7 @@
     <Compile Include="Reflection\MethodDescriptor.cs" />
     <Compile Include="Reflection\OneofAccessor.cs" />
     <Compile Include="Reflection\OneofDescriptor.cs" />
+    <Compile Include="Reflection\OriginalNameAttribute.cs" />
     <Compile Include="Reflection\PackageDescriptor.cs" />
     <Compile Include="Reflection\PartialClasses.cs" />
     <Compile Include="Reflection\ReflectionUtil.cs" />

csharp/src/Google.Protobuf/Google.Protobuf.nuspec

@@ -23,7 +23,6 @@
       <group targetFramework="xamarin.ios" />
       <group targetFramework="monotouch" />
       <group targetFramework="monoandroid" />
-
       <!-- Dependencies for newer, more granular platforms (.NET Core etc) -->
       <group targetFramework="dotnet">
         <dependency id="System.Collections" version="4.0.0" />
@@ -34,10 +33,12 @@
         <dependency id="System.Linq.Expressions" version="4.0.0" />
         <dependency id="System.ObjectModel" version="4.0.0" />
         <dependency id="System.Reflection" version="4.0.0" />
+        <dependency id="System.Reflection.Extensions" version="4.0.0" />
         <dependency id="System.Runtime" version="4.0.0" />
         <dependency id="System.Runtime.Extensions" version="4.0.0" />
         <dependency id="System.Text.Encoding" version="4.0.0" />
         <dependency id="System.Text.RegularExpressions" version="4.0.0" />
+        <dependency id="System.Threading" version="4.0.0" />
       </group>
     </dependencies>
   </metadata>
@@ -49,18 +50,5 @@
     <file src="bin/ReleaseSigned/Google.Protobuf.pdb" target="lib/dotnet" />
     <file src="bin/ReleaseSigned/Google.Protobuf.xml" target="lib/dotnet" />
     <file src="**\*.cs" target="src" />
-    <file src="..\..\..\cmake\Release\protoc.exe" target="tools" />
-    <file src="..\..\..\src\google\protobuf\any.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\api.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\descriptor.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\duration.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\empty.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\field_mask.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\source_context.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\struct.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\timestamp.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\any.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\type.proto" target="tools\google\protobuf" />
-    <file src="..\..\..\src\google\protobuf\wrappers.proto" target="tools\google\protobuf" />
   </files>
 </package>

csharp/src/Google.Protobuf/JsonFormatter.cs

@@ -39,6 +39,7 @@ using Google.Protobuf.WellKnownTypes;
 using System.IO;
 using System.Linq;
 using System.Collections.Generic;
+using System.Reflection;
 
 namespace Google.Protobuf
 {
@@ -237,11 +238,13 @@ namespace Google.Protobuf
                 {
                     writer.Write(PropertySeparator);
                 }
-                WriteString(writer, ToCamelCase(accessor.Descriptor.Name));
+
+                WriteString(writer, accessor.Descriptor.JsonName);
                 writer.Write(NameValueSeparator);
                 WriteValue(writer, value);
+
                 first = false;
-            }            
+            }
             return !first;
         }
 
@@ -418,9 +421,10 @@ namespace Google.Protobuf
             }
             else if (value is System.Enum)
             {
-                if (System.Enum.IsDefined(value.GetType(), value))
+                string name = OriginalEnumValueHelper.GetOriginalName(value);
+                if (name != null)
                 {
-                    WriteString(writer, value.ToString());
+                    WriteString(writer, name);
                 }
                 else
                 {
@@ -563,7 +567,7 @@ namespace Google.Protobuf
 
             string typeUrl = (string) value.Descriptor.Fields[Any.TypeUrlFieldNumber].Accessor.GetValue(value);
             ByteString data = (ByteString) value.Descriptor.Fields[Any.ValueFieldNumber].Accessor.GetValue(value);
-            string typeName = GetTypeName(typeUrl);
+            string typeName = Any.GetTypeName(typeUrl);
             MessageDescriptor descriptor = settings.TypeRegistry.Find(typeName);
             if (descriptor == null)
             {
@@ -604,17 +608,7 @@ namespace Google.Protobuf
             writer.Write(data.ToBase64());
             writer.Write('"');
             writer.Write(" }");
-        }
-
-        internal static string GetTypeName(String typeUrl)
-        {
-            string[] parts = typeUrl.Split('/');
-            if (parts.Length != 2 || parts[0] != TypeUrlPrefix)
-            {
-                throw new InvalidProtocolBufferException($"Invalid type url: {typeUrl}");
-            }
-            return parts[1];
-        }
+        }        
 
         private void WriteStruct(TextWriter writer, IMessage message)
         {
@@ -875,5 +869,44 @@ namespace Google.Protobuf
                 TypeRegistry = ProtoPreconditions.CheckNotNull(typeRegistry, nameof(typeRegistry));
             }
         }
+
+        // Effectively a cache of mapping from enum values to the original name as specified in the proto file,
+        // fetched by reflection.
+        // The need for this is unfortunate, as is its unbounded size, but realistically it shouldn't cause issues.
+        private static class OriginalEnumValueHelper
+        {
+            // TODO: In the future we might want to use ConcurrentDictionary, at the point where all
+            // the platforms we target have it.
+            private static readonly Dictionary<System.Type, Dictionary<object, string>> dictionaries
+                = new Dictionary<System.Type, Dictionary<object, string>>();
+            
+            internal static string GetOriginalName(object value)
+            {
+                var enumType = value.GetType();
+                Dictionary<object, string> nameMapping;
+                lock (dictionaries)
+                {
+                    if (!dictionaries.TryGetValue(enumType, out nameMapping))
+                    {
+                        nameMapping = GetNameMapping(enumType);
+                        dictionaries[enumType] = nameMapping;
+                    }
+                }
+
+                string originalName;
+                // If this returns false, originalName will be null, which is what we want.
+                nameMapping.TryGetValue(value, out originalName);
+                return originalName;
+            }
+
+            private static Dictionary<object, string> GetNameMapping(System.Type enumType) =>
+                enumType.GetTypeInfo().DeclaredFields
+                    .Where(f => f.IsStatic)
+                    .ToDictionary(f => f.GetValue(null),
+                                  f => f.GetCustomAttributes<OriginalNameAttribute>()
+                                        .FirstOrDefault()
+                                        // If the attribute hasn't been applied, fall back to the name of the field.
+                                        ?.Name ?? f.Name);
+        }
     }
 }

csharp/src/Google.Protobuf/JsonParser.cs

@@ -513,7 +513,7 @@ namespace Google.Protobuf
                 throw new InvalidProtocolBufferException("Expected string value for Any.@type");
             }
             string typeUrl = token.StringValue;
-            string typeName = JsonFormatter.GetTypeName(typeUrl);
+            string typeName = Any.GetTypeName(typeUrl);
 
             MessageDescriptor descriptor = settings.TypeRegistry.Find(typeName);
             if (descriptor == null)

csharp/src/Google.Protobuf/Reflection/Descriptor.cs

@@ -80,7 +80,7 @@ namespace Google.Protobuf.Reflection {
             "EhMKC291dHB1dF90eXBlGAMgASgJEi8KB29wdGlvbnMYBCABKAsyHi5nb29n",
             "bGUucHJvdG9idWYuTWV0aG9kT3B0aW9ucxIfChBjbGllbnRfc3RyZWFtaW5n",
             "GAUgASgIOgVmYWxzZRIfChBzZXJ2ZXJfc3RyZWFtaW5nGAYgASgIOgVmYWxz",
-            "ZSKuBQoLRmlsZU9wdGlvbnMSFAoMamF2YV9wYWNrYWdlGAEgASgJEhwKFGph",
+            "ZSKHBQoLRmlsZU9wdGlvbnMSFAoMamF2YV9wYWNrYWdlGAEgASgJEhwKFGph",
             "dmFfb3V0ZXJfY2xhc3NuYW1lGAggASgJEiIKE2phdmFfbXVsdGlwbGVfZmls",
             "ZXMYCiABKAg6BWZhbHNlEiwKHWphdmFfZ2VuZXJhdGVfZXF1YWxzX2FuZF9o",
             "YXNoGBQgASgIOgVmYWxzZRIlChZqYXZhX3N0cmluZ19jaGVja191dGY4GBsg",
@@ -91,54 +91,53 @@ namespace Google.Protobuf.Reflection {
             "cHlfZ2VuZXJpY19zZXJ2aWNlcxgSIAEoCDoFZmFsc2USGQoKZGVwcmVjYXRl",
             "ZBgXIAEoCDoFZmFsc2USHwoQY2NfZW5hYmxlX2FyZW5hcxgfIAEoCDoFZmFs",
             "c2USGQoRb2JqY19jbGFzc19wcmVmaXgYJCABKAkSGAoQY3NoYXJwX25hbWVz",
-            "cGFjZRglIAEoCRIrCh9qYXZhbmFub191c2VfZGVwcmVjYXRlZF9wYWNrYWdl",
-            "GCYgASgIQgIYARJDChR1bmludGVycHJldGVkX29wdGlvbhjnByADKAsyJC5n",
+            "cGFjZRglIAEoCRJDChR1bmludGVycHJldGVkX29wdGlvbhjnByADKAsyJC5n",
             "b29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlvbiI6CgxPcHRpbWl6",
             "ZU1vZGUSCQoFU1BFRUQQARINCglDT0RFX1NJWkUQAhIQCgxMSVRFX1JVTlRJ",
-            "TUUQAyoJCOgHEICAgIACIuYBCg5NZXNzYWdlT3B0aW9ucxImChdtZXNzYWdl",
-            "X3NldF93aXJlX2Zvcm1hdBgBIAEoCDoFZmFsc2USLgofbm9fc3RhbmRhcmRf",
-            "ZGVzY3JpcHRvcl9hY2Nlc3NvchgCIAEoCDoFZmFsc2USGQoKZGVwcmVjYXRl",
-            "ZBgDIAEoCDoFZmFsc2USEQoJbWFwX2VudHJ5GAcgASgIEkMKFHVuaW50ZXJw",
-            "cmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5VbmludGVy",
-            "cHJldGVkT3B0aW9uKgkI6AcQgICAgAIimAMKDEZpZWxkT3B0aW9ucxI6CgVj",
-            "dHlwZRgBIAEoDjIjLmdvb2dsZS5wcm90b2J1Zi5GaWVsZE9wdGlvbnMuQ1R5",
-            "cGU6BlNUUklORxIOCgZwYWNrZWQYAiABKAgSPwoGanN0eXBlGAYgASgOMiQu",
-            "Z29vZ2xlLnByb3RvYnVmLkZpZWxkT3B0aW9ucy5KU1R5cGU6CUpTX05PUk1B",
-            "TBITCgRsYXp5GAUgASgIOgVmYWxzZRIZCgpkZXByZWNhdGVkGAMgASgIOgVm",
-            "YWxzZRITCgR3ZWFrGAogASgIOgVmYWxzZRJDChR1bmludGVycHJldGVkX29w",
+            "TUUQAyoJCOgHEICAgIACSgQIJhAnIuYBCg5NZXNzYWdlT3B0aW9ucxImChdt",
+            "ZXNzYWdlX3NldF93aXJlX2Zvcm1hdBgBIAEoCDoFZmFsc2USLgofbm9fc3Rh",
+            "bmRhcmRfZGVzY3JpcHRvcl9hY2Nlc3NvchgCIAEoCDoFZmFsc2USGQoKZGVw",
+            "cmVjYXRlZBgDIAEoCDoFZmFsc2USEQoJbWFwX2VudHJ5GAcgASgIEkMKFHVu",
+            "aW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5V",
+            "bmludGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIimAMKDEZpZWxkT3B0aW9u",
+            "cxI6CgVjdHlwZRgBIAEoDjIjLmdvb2dsZS5wcm90b2J1Zi5GaWVsZE9wdGlv",
+            "bnMuQ1R5cGU6BlNUUklORxIOCgZwYWNrZWQYAiABKAgSPwoGanN0eXBlGAYg",
+            "ASgOMiQuZ29vZ2xlLnByb3RvYnVmLkZpZWxkT3B0aW9ucy5KU1R5cGU6CUpT",
+            "X05PUk1BTBITCgRsYXp5GAUgASgIOgVmYWxzZRIZCgpkZXByZWNhdGVkGAMg",
+            "ASgIOgVmYWxzZRITCgR3ZWFrGAogASgIOgVmYWxzZRJDChR1bmludGVycHJl",
+            "dGVkX29wdGlvbhjnByADKAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRlcnBy",
+            "ZXRlZE9wdGlvbiIvCgVDVHlwZRIKCgZTVFJJTkcQABIICgRDT1JEEAESEAoM",
+            "U1RSSU5HX1BJRUNFEAIiNQoGSlNUeXBlEg0KCUpTX05PUk1BTBAAEg0KCUpT",
+            "X1NUUklORxABEg0KCUpTX05VTUJFUhACKgkI6AcQgICAgAIijQEKC0VudW1P",
+            "cHRpb25zEhMKC2FsbG93X2FsaWFzGAIgASgIEhkKCmRlcHJlY2F0ZWQYAyAB",
+            "KAg6BWZhbHNlEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdv",
+            "b2dsZS5wcm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIi",
+            "fQoQRW51bVZhbHVlT3B0aW9ucxIZCgpkZXByZWNhdGVkGAEgASgIOgVmYWxz",
+            "ZRJDChR1bmludGVycHJldGVkX29wdGlvbhjnByADKAsyJC5nb29nbGUucHJv",
+            "dG9idWYuVW5pbnRlcnByZXRlZE9wdGlvbioJCOgHEICAgIACInsKDlNlcnZp",
+            "Y2VPcHRpb25zEhkKCmRlcHJlY2F0ZWQYISABKAg6BWZhbHNlEkMKFHVuaW50",
+            "ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5Vbmlu",
+            "dGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIiegoNTWV0aG9kT3B0aW9ucxIZ",
+            "CgpkZXByZWNhdGVkGCEgASgIOgVmYWxzZRJDChR1bmludGVycHJldGVkX29w",
             "dGlvbhjnByADKAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9w",
-            "dGlvbiIvCgVDVHlwZRIKCgZTVFJJTkcQABIICgRDT1JEEAESEAoMU1RSSU5H",
-            "X1BJRUNFEAIiNQoGSlNUeXBlEg0KCUpTX05PUk1BTBAAEg0KCUpTX1NUUklO",
-            "RxABEg0KCUpTX05VTUJFUhACKgkI6AcQgICAgAIijQEKC0VudW1PcHRpb25z",
-            "EhMKC2FsbG93X2FsaWFzGAIgASgIEhkKCmRlcHJlY2F0ZWQYAyABKAg6BWZh",
-            "bHNlEkMKFHVuaW50ZXJwcmV0ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5w",
-            "cm90b2J1Zi5VbmludGVycHJldGVkT3B0aW9uKgkI6AcQgICAgAIifQoQRW51",
-            "bVZhbHVlT3B0aW9ucxIZCgpkZXByZWNhdGVkGAEgASgIOgVmYWxzZRJDChR1",
-            "bmludGVycHJldGVkX29wdGlvbhjnByADKAsyJC5nb29nbGUucHJvdG9idWYu",
-            "VW5pbnRlcnByZXRlZE9wdGlvbioJCOgHEICAgIACInsKDlNlcnZpY2VPcHRp",
-            "b25zEhkKCmRlcHJlY2F0ZWQYISABKAg6BWZhbHNlEkMKFHVuaW50ZXJwcmV0",
-            "ZWRfb3B0aW9uGOcHIAMoCzIkLmdvb2dsZS5wcm90b2J1Zi5VbmludGVycHJl",
-            "dGVkT3B0aW9uKgkI6AcQgICAgAIiegoNTWV0aG9kT3B0aW9ucxIZCgpkZXBy",
-            "ZWNhdGVkGCEgASgIOgVmYWxzZRJDChR1bmludGVycHJldGVkX29wdGlvbhjn",
-            "ByADKAsyJC5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlvbioJ",
-            "COgHEICAgIACIp4CChNVbmludGVycHJldGVkT3B0aW9uEjsKBG5hbWUYAiAD",
-            "KAsyLS5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlvbi5OYW1l",
-            "UGFydBIYChBpZGVudGlmaWVyX3ZhbHVlGAMgASgJEhoKEnBvc2l0aXZlX2lu",
-            "dF92YWx1ZRgEIAEoBBIaChJuZWdhdGl2ZV9pbnRfdmFsdWUYBSABKAMSFAoM",
-            "ZG91YmxlX3ZhbHVlGAYgASgBEhQKDHN0cmluZ192YWx1ZRgHIAEoDBIXCg9h",
-            "Z2dyZWdhdGVfdmFsdWUYCCABKAkaMwoITmFtZVBhcnQSEQoJbmFtZV9wYXJ0",
-            "GAEgAigJEhQKDGlzX2V4dGVuc2lvbhgCIAIoCCLVAQoOU291cmNlQ29kZUlu",
-            "Zm8SOgoIbG9jYXRpb24YASADKAsyKC5nb29nbGUucHJvdG9idWYuU291cmNl",
-            "Q29kZUluZm8uTG9jYXRpb24ahgEKCExvY2F0aW9uEhAKBHBhdGgYASADKAVC",
-            "AhABEhAKBHNwYW4YAiADKAVCAhABEhgKEGxlYWRpbmdfY29tbWVudHMYAyAB",
-            "KAkSGQoRdHJhaWxpbmdfY29tbWVudHMYBCABKAkSIQoZbGVhZGluZ19kZXRh",
-            "Y2hlZF9jb21tZW50cxgGIAMoCSKnAQoRR2VuZXJhdGVkQ29kZUluZm8SQQoK",
-            "YW5ub3RhdGlvbhgBIAMoCzItLmdvb2dsZS5wcm90b2J1Zi5HZW5lcmF0ZWRD",
-            "b2RlSW5mby5Bbm5vdGF0aW9uGk8KCkFubm90YXRpb24SEAoEcGF0aBgBIAMo",
-            "BUICEAESEwoLc291cmNlX2ZpbGUYAiABKAkSDQoFYmVnaW4YAyABKAUSCwoD",
-            "ZW5kGAQgASgFQlgKE2NvbS5nb29nbGUucHJvdG9idWZCEERlc2NyaXB0b3JQ",
-            "cm90b3NIAVoKZGVzY3JpcHRvcqICA0dQQqoCGkdvb2dsZS5Qcm90b2J1Zi5S",
-            "ZWZsZWN0aW9u"));
+            "dGlvbioJCOgHEICAgIACIp4CChNVbmludGVycHJldGVkT3B0aW9uEjsKBG5h",
+            "bWUYAiADKAsyLS5nb29nbGUucHJvdG9idWYuVW5pbnRlcnByZXRlZE9wdGlv",
+            "bi5OYW1lUGFydBIYChBpZGVudGlmaWVyX3ZhbHVlGAMgASgJEhoKEnBvc2l0",
+            "aXZlX2ludF92YWx1ZRgEIAEoBBIaChJuZWdhdGl2ZV9pbnRfdmFsdWUYBSAB",
+            "KAMSFAoMZG91YmxlX3ZhbHVlGAYgASgBEhQKDHN0cmluZ192YWx1ZRgHIAEo",
+            "DBIXCg9hZ2dyZWdhdGVfdmFsdWUYCCABKAkaMwoITmFtZVBhcnQSEQoJbmFt",
+            "ZV9wYXJ0GAEgAigJEhQKDGlzX2V4dGVuc2lvbhgCIAIoCCLVAQoOU291cmNl",
+            "Q29kZUluZm8SOgoIbG9jYXRpb24YASADKAsyKC5nb29nbGUucHJvdG9idWYu",
+            "U291cmNlQ29kZUluZm8uTG9jYXRpb24ahgEKCExvY2F0aW9uEhAKBHBhdGgY",
+            "ASADKAVCAhABEhAKBHNwYW4YAiADKAVCAhABEhgKEGxlYWRpbmdfY29tbWVu",
+            "dHMYAyABKAkSGQoRdHJhaWxpbmdfY29tbWVudHMYBCABKAkSIQoZbGVhZGlu",
+            "Z19kZXRhY2hlZF9jb21tZW50cxgGIAMoCSKnAQoRR2VuZXJhdGVkQ29kZUlu",
+            "Zm8SQQoKYW5ub3RhdGlvbhgBIAMoCzItLmdvb2dsZS5wcm90b2J1Zi5HZW5l",
+            "cmF0ZWRDb2RlSW5mby5Bbm5vdGF0aW9uGk8KCkFubm90YXRpb24SEAoEcGF0",
+            "aBgBIAMoBUICEAESEwoLc291cmNlX2ZpbGUYAiABKAkSDQoFYmVnaW4YAyAB",
+            "KAUSCwoDZW5kGAQgASgFQlgKE2NvbS5nb29nbGUucHJvdG9idWZCEERlc2Ny",
+            "aXB0b3JQcm90b3NIAVoKZGVzY3JpcHRvcqICA0dQQqoCGkdvb2dsZS5Qcm90",
+            "b2J1Zi5SZWZsZWN0aW9u"));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
@@ -152,7 +151,7 @@ namespace Google.Protobuf.Reflection {
             new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.EnumValueDescriptorProto), global::Google.Protobuf.Reflection.EnumValueDescriptorProto.Parser, new[]{ "Name", "Number", "Options" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.ServiceDescriptorProto), global::Google.Protobuf.Reflection.ServiceDescriptorProto.Parser, new[]{ "Name", "Method", "Options" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.MethodDescriptorProto), global::Google.Protobuf.Reflection.MethodDescriptorProto.Parser, new[]{ "Name", "InputType", "OutputType", "Options", "ClientStreaming", "ServerStreaming" }, null, null, null),
-            new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.FileOptions), global::Google.Protobuf.Reflection.FileOptions.Parser, new[]{ "JavaPackage", "JavaOuterClassname", "JavaMultipleFiles", "JavaGenerateEqualsAndHash", "JavaStringCheckUtf8", "OptimizeFor", "GoPackage", "CcGenericServices", "JavaGenericServices", "PyGenericServices", "Deprecated", "CcEnableArenas", "ObjcClassPrefix", "CsharpNamespace", "JavananoUseDeprecatedPackage", "UninterpretedOption" }, null, new[]{ typeof(global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode) }, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.FileOptions), global::Google.Protobuf.Reflection.FileOptions.Parser, new[]{ "JavaPackage", "JavaOuterClassname", "JavaMultipleFiles", "JavaGenerateEqualsAndHash", "JavaStringCheckUtf8", "OptimizeFor", "GoPackage", "CcGenericServices", "JavaGenericServices", "PyGenericServices", "Deprecated", "CcEnableArenas", "ObjcClassPrefix", "CsharpNamespace", "UninterpretedOption" }, null, new[]{ typeof(global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode) }, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.MessageOptions), global::Google.Protobuf.Reflection.MessageOptions.Parser, new[]{ "MessageSetWireFormat", "NoStandardDescriptorAccessor", "Deprecated", "MapEntry", "UninterpretedOption" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.FieldOptions), global::Google.Protobuf.Reflection.FieldOptions.Parser, new[]{ "Ctype", "Packed", "Jstype", "Lazy", "Deprecated", "Weak", "UninterpretedOption" }, null, new[]{ typeof(global::Google.Protobuf.Reflection.FieldOptions.Types.CType), typeof(global::Google.Protobuf.Reflection.FieldOptions.Types.JSType) }, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Reflection.EnumOptions), global::Google.Protobuf.Reflection.EnumOptions.Parser, new[]{ "AllowAlias", "Deprecated", "UninterpretedOption" }, null, null, null),
@@ -1291,7 +1290,7 @@ namespace Google.Protobuf.Reflection {
 
     /// <summary>Field number for the "label" field.</summary>
     public const int LabelFieldNumber = 4;
-    private global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label label_ = global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label.LABEL_OPTIONAL;
+    private global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label label_ = 0;
     public global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label Label {
       get { return label_; }
       set {
@@ -1301,7 +1300,7 @@ namespace Google.Protobuf.Reflection {
 
     /// <summary>Field number for the "type" field.</summary>
     public const int TypeFieldNumber = 5;
-    private global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type type_ = global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type.TYPE_DOUBLE;
+    private global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type type_ = 0;
     /// <summary>
     ///  If type_name is set, this need not be set.  If both this and type_name
     ///  are set, this must be one of TYPE_ENUM, TYPE_MESSAGE or TYPE_GROUP.
@@ -1429,8 +1428,8 @@ namespace Google.Protobuf.Reflection {
       int hash = 1;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (Number != 0) hash ^= Number.GetHashCode();
-      if (Label != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label.LABEL_OPTIONAL) hash ^= Label.GetHashCode();
-      if (Type != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type.TYPE_DOUBLE) hash ^= Type.GetHashCode();
+      if (Label != 0) hash ^= Label.GetHashCode();
+      if (Type != 0) hash ^= Type.GetHashCode();
       if (TypeName.Length != 0) hash ^= TypeName.GetHashCode();
       if (Extendee.Length != 0) hash ^= Extendee.GetHashCode();
       if (DefaultValue.Length != 0) hash ^= DefaultValue.GetHashCode();
@@ -1457,11 +1456,11 @@ namespace Google.Protobuf.Reflection {
         output.WriteRawTag(24);
         output.WriteInt32(Number);
       }
-      if (Label != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label.LABEL_OPTIONAL) {
+      if (Label != 0) {
         output.WriteRawTag(32);
         output.WriteEnum((int) Label);
       }
-      if (Type != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type.TYPE_DOUBLE) {
+      if (Type != 0) {
         output.WriteRawTag(40);
         output.WriteEnum((int) Type);
       }
@@ -1495,10 +1494,10 @@ namespace Google.Protobuf.Reflection {
       if (Number != 0) {
         size += 1 + pb::CodedOutputStream.ComputeInt32Size(Number);
       }
-      if (Label != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label.LABEL_OPTIONAL) {
+      if (Label != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Label);
       }
-      if (Type != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type.TYPE_DOUBLE) {
+      if (Type != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Type);
       }
       if (TypeName.Length != 0) {
@@ -1532,10 +1531,10 @@ namespace Google.Protobuf.Reflection {
       if (other.Number != 0) {
         Number = other.Number;
       }
-      if (other.Label != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Label.LABEL_OPTIONAL) {
+      if (other.Label != 0) {
         Label = other.Label;
       }
-      if (other.Type != global::Google.Protobuf.Reflection.FieldDescriptorProto.Types.Type.TYPE_DOUBLE) {
+      if (other.Type != 0) {
         Type = other.Type;
       }
       if (other.TypeName.Length != 0) {
@@ -1624,59 +1623,59 @@ namespace Google.Protobuf.Reflection {
         ///  0 is reserved for errors.
         ///  Order is weird for historical reasons.
         /// </summary>
-        TYPE_DOUBLE = 1,
-        TYPE_FLOAT = 2,
+        [pbr::OriginalName("TYPE_DOUBLE")] Double = 1,
+        [pbr::OriginalName("TYPE_FLOAT")] Float = 2,
         /// <summary>
         ///  Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT64 if
         ///  negative values are likely.
         /// </summary>
-        TYPE_INT64 = 3,
-        TYPE_UINT64 = 4,
+        [pbr::OriginalName("TYPE_INT64")] Int64 = 3,
+        [pbr::OriginalName("TYPE_UINT64")] Uint64 = 4,
         /// <summary>
         ///  Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT32 if
         ///  negative values are likely.
         /// </summary>
-        TYPE_INT32 = 5,
-        TYPE_FIXED64 = 6,
-        TYPE_FIXED32 = 7,
-        TYPE_BOOL = 8,
-        TYPE_STRING = 9,
+        [pbr::OriginalName("TYPE_INT32")] Int32 = 5,
+        [pbr::OriginalName("TYPE_FIXED64")] Fixed64 = 6,
+        [pbr::OriginalName("TYPE_FIXED32")] Fixed32 = 7,
+        [pbr::OriginalName("TYPE_BOOL")] Bool = 8,
+        [pbr::OriginalName("TYPE_STRING")] String = 9,
         /// <summary>
         ///  Tag-delimited aggregate.
         /// </summary>
-        TYPE_GROUP = 10,
+        [pbr::OriginalName("TYPE_GROUP")] Group = 10,
         /// <summary>
         ///  Length-delimited aggregate.
         /// </summary>
-        TYPE_MESSAGE = 11,
+        [pbr::OriginalName("TYPE_MESSAGE")] Message = 11,
         /// <summary>
         ///  New in version 2.
         /// </summary>
-        TYPE_BYTES = 12,
-        TYPE_UINT32 = 13,
-        TYPE_ENUM = 14,
-        TYPE_SFIXED32 = 15,
-        TYPE_SFIXED64 = 16,
+        [pbr::OriginalName("TYPE_BYTES")] Bytes = 12,
+        [pbr::OriginalName("TYPE_UINT32")] Uint32 = 13,
+        [pbr::OriginalName("TYPE_ENUM")] Enum = 14,
+        [pbr::OriginalName("TYPE_SFIXED32")] Sfixed32 = 15,
+        [pbr::OriginalName("TYPE_SFIXED64")] Sfixed64 = 16,
         /// <summary>
         ///  Uses ZigZag encoding.
         /// </summary>
-        TYPE_SINT32 = 17,
+        [pbr::OriginalName("TYPE_SINT32")] Sint32 = 17,
         /// <summary>
         ///  Uses ZigZag encoding.
         /// </summary>
-        TYPE_SINT64 = 18,
+        [pbr::OriginalName("TYPE_SINT64")] Sint64 = 18,
       }
 
       internal enum Label {
         /// <summary>
         ///  0 is reserved for errors
         /// </summary>
-        LABEL_OPTIONAL = 1,
-        LABEL_REQUIRED = 2,
+        [pbr::OriginalName("LABEL_OPTIONAL")] Optional = 1,
+        [pbr::OriginalName("LABEL_REQUIRED")] Required = 2,
         /// <summary>
         ///  TODO(sanjay): Should we add LABEL_MAP?
         /// </summary>
-        LABEL_REPEATED = 3,
+        [pbr::OriginalName("LABEL_REPEATED")] Repeated = 3,
       }
 
     }
@@ -2563,7 +2562,6 @@ namespace Google.Protobuf.Reflection {
       ccEnableArenas_ = other.ccEnableArenas_;
       objcClassPrefix_ = other.objcClassPrefix_;
       csharpNamespace_ = other.csharpNamespace_;
-      javananoUseDeprecatedPackage_ = other.javananoUseDeprecatedPackage_;
       uninterpretedOption_ = other.uninterpretedOption_.Clone();
     }
 
@@ -2666,7 +2664,7 @@ namespace Google.Protobuf.Reflection {
 
     /// <summary>Field number for the "optimize_for" field.</summary>
     public const int OptimizeForFieldNumber = 9;
-    private global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode optimizeFor_ = global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode.SPEED;
+    private global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode optimizeFor_ = 0;
     public global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode OptimizeFor {
       get { return optimizeFor_; }
       set {
@@ -2790,21 +2788,6 @@ namespace Google.Protobuf.Reflection {
       }
     }
 
-    /// <summary>Field number for the "javanano_use_deprecated_package" field.</summary>
-    public const int JavananoUseDeprecatedPackageFieldNumber = 38;
-    private bool javananoUseDeprecatedPackage_;
-    /// <summary>
-    ///  Whether the nano proto compiler should generate in the deprecated non-nano
-    ///  suffixed package.
-    /// </summary>
-    [global::System.ObsoleteAttribute()]
-    public bool JavananoUseDeprecatedPackage {
-      get { return javananoUseDeprecatedPackage_; }
-      set {
-        javananoUseDeprecatedPackage_ = value;
-      }
-    }
-
     /// <summary>Field number for the "uninterpreted_option" field.</summary>
     public const int UninterpretedOptionFieldNumber = 999;
     private static readonly pb::FieldCodec<global::Google.Protobuf.Reflection.UninterpretedOption> _repeated_uninterpretedOption_codec
@@ -2842,7 +2825,6 @@ namespace Google.Protobuf.Reflection {
       if (CcEnableArenas != other.CcEnableArenas) return false;
       if (ObjcClassPrefix != other.ObjcClassPrefix) return false;
       if (CsharpNamespace != other.CsharpNamespace) return false;
-      if (JavananoUseDeprecatedPackage != other.JavananoUseDeprecatedPackage) return false;
       if(!uninterpretedOption_.Equals(other.uninterpretedOption_)) return false;
       return true;
     }
@@ -2854,7 +2836,7 @@ namespace Google.Protobuf.Reflection {
       if (JavaMultipleFiles != false) hash ^= JavaMultipleFiles.GetHashCode();
       if (JavaGenerateEqualsAndHash != false) hash ^= JavaGenerateEqualsAndHash.GetHashCode();
       if (JavaStringCheckUtf8 != false) hash ^= JavaStringCheckUtf8.GetHashCode();
-      if (OptimizeFor != global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode.SPEED) hash ^= OptimizeFor.GetHashCode();
+      if (OptimizeFor != 0) hash ^= OptimizeFor.GetHashCode();
       if (GoPackage.Length != 0) hash ^= GoPackage.GetHashCode();
       if (CcGenericServices != false) hash ^= CcGenericServices.GetHashCode();
       if (JavaGenericServices != false) hash ^= JavaGenericServices.GetHashCode();
@@ -2863,7 +2845,6 @@ namespace Google.Protobuf.Reflection {
       if (CcEnableArenas != false) hash ^= CcEnableArenas.GetHashCode();
       if (ObjcClassPrefix.Length != 0) hash ^= ObjcClassPrefix.GetHashCode();
       if (CsharpNamespace.Length != 0) hash ^= CsharpNamespace.GetHashCode();
-      if (JavananoUseDeprecatedPackage != false) hash ^= JavananoUseDeprecatedPackage.GetHashCode();
       hash ^= uninterpretedOption_.GetHashCode();
       return hash;
     }
@@ -2881,7 +2862,7 @@ namespace Google.Protobuf.Reflection {
         output.WriteRawTag(66);
         output.WriteString(JavaOuterClassname);
       }
-      if (OptimizeFor != global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode.SPEED) {
+      if (OptimizeFor != 0) {
         output.WriteRawTag(72);
         output.WriteEnum((int) OptimizeFor);
       }
@@ -2929,10 +2910,6 @@ namespace Google.Protobuf.Reflection {
         output.WriteRawTag(170, 2);
         output.WriteString(CsharpNamespace);
       }
-      if (JavananoUseDeprecatedPackage != false) {
-        output.WriteRawTag(176, 2);
-        output.WriteBool(JavananoUseDeprecatedPackage);
-      }
       uninterpretedOption_.WriteTo(output, _repeated_uninterpretedOption_codec);
     }
 
@@ -2953,7 +2930,7 @@ namespace Google.Protobuf.Reflection {
       if (JavaStringCheckUtf8 != false) {
         size += 2 + 1;
       }
-      if (OptimizeFor != global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode.SPEED) {
+      if (OptimizeFor != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) OptimizeFor);
       }
       if (GoPackage.Length != 0) {
@@ -2980,9 +2957,6 @@ namespace Google.Protobuf.Reflection {
       if (CsharpNamespace.Length != 0) {
         size += 2 + pb::CodedOutputStream.ComputeStringSize(CsharpNamespace);
       }
-      if (JavananoUseDeprecatedPackage != false) {
-        size += 2 + 1;
-      }
       size += uninterpretedOption_.CalculateSize(_repeated_uninterpretedOption_codec);
       return size;
     }
@@ -3006,7 +2980,7 @@ namespace Google.Protobuf.Reflection {
       if (other.JavaStringCheckUtf8 != false) {
         JavaStringCheckUtf8 = other.JavaStringCheckUtf8;
       }
-      if (other.OptimizeFor != global::Google.Protobuf.Reflection.FileOptions.Types.OptimizeMode.SPEED) {
+      if (other.OptimizeFor != 0) {
         OptimizeFor = other.OptimizeFor;
       }
       if (other.GoPackage.Length != 0) {
@@ -3033,9 +3007,6 @@ namespace Google.Protobuf.Reflection {
       if (other.CsharpNamespace.Length != 0) {
         CsharpNamespace = other.CsharpNamespace;
       }
-      if (other.JavananoUseDeprecatedPackage != false) {
-        JavananoUseDeprecatedPackage = other.JavananoUseDeprecatedPackage;
-      }
       uninterpretedOption_.Add(other.uninterpretedOption_);
     }
 
@@ -3102,10 +3073,6 @@ namespace Google.Protobuf.Reflection {
             CsharpNamespace = input.ReadString();
             break;
           }
-          case 304: {
-            JavananoUseDeprecatedPackage = input.ReadBool();
-            break;
-          }
           case 7994: {
             uninterpretedOption_.AddEntriesFrom(input, _repeated_uninterpretedOption_codec);
             break;
@@ -3125,15 +3092,15 @@ namespace Google.Protobuf.Reflection {
         /// <summary>
         ///  Generate complete code for parsing, serialization,
         /// </summary>
-        SPEED = 1,
+        [pbr::OriginalName("SPEED")] Speed = 1,
         /// <summary>
         ///  etc.
         /// </summary>
-        CODE_SIZE = 2,
+        [pbr::OriginalName("CODE_SIZE")] CodeSize = 2,
         /// <summary>
         ///  Generate code using MessageLite and the lite runtime.
         /// </summary>
-        LITE_RUNTIME = 3,
+        [pbr::OriginalName("LITE_RUNTIME")] LiteRuntime = 3,
       }
 
     }
@@ -3436,7 +3403,7 @@ namespace Google.Protobuf.Reflection {
 
     /// <summary>Field number for the "ctype" field.</summary>
     public const int CtypeFieldNumber = 1;
-    private global::Google.Protobuf.Reflection.FieldOptions.Types.CType ctype_ = global::Google.Protobuf.Reflection.FieldOptions.Types.CType.STRING;
+    private global::Google.Protobuf.Reflection.FieldOptions.Types.CType ctype_ = 0;
     /// <summary>
     ///  The ctype option instructs the C++ code generator to use a different
     ///  representation of the field than it normally would.  See the specific
@@ -3469,7 +3436,7 @@ namespace Google.Protobuf.Reflection {
 
     /// <summary>Field number for the "jstype" field.</summary>
     public const int JstypeFieldNumber = 6;
-    private global::Google.Protobuf.Reflection.FieldOptions.Types.JSType jstype_ = global::Google.Protobuf.Reflection.FieldOptions.Types.JSType.JS_NORMAL;
+    private global::Google.Protobuf.Reflection.FieldOptions.Types.JSType jstype_ = 0;
     /// <summary>
     ///  The jstype option determines the JavaScript type used for values of the
     ///  field.  The option is permitted only for 64 bit integral and fixed types
@@ -3591,9 +3558,9 @@ namespace Google.Protobuf.Reflection {
 
     public override int GetHashCode() {
       int hash = 1;
-      if (Ctype != global::Google.Protobuf.Reflection.FieldOptions.Types.CType.STRING) hash ^= Ctype.GetHashCode();
+      if (Ctype != 0) hash ^= Ctype.GetHashCode();
       if (Packed != false) hash ^= Packed.GetHashCode();
-      if (Jstype != global::Google.Protobuf.Reflection.FieldOptions.Types.JSType.JS_NORMAL) hash ^= Jstype.GetHashCode();
+      if (Jstype != 0) hash ^= Jstype.GetHashCode();
       if (Lazy != false) hash ^= Lazy.GetHashCode();
       if (Deprecated != false) hash ^= Deprecated.GetHashCode();
       if (Weak != false) hash ^= Weak.GetHashCode();
@@ -3606,7 +3573,7 @@ namespace Google.Protobuf.Reflection {
     }
 
     public void WriteTo(pb::CodedOutputStream output) {
-      if (Ctype != global::Google.Protobuf.Reflection.FieldOptions.Types.CType.STRING) {
+      if (Ctype != 0) {
         output.WriteRawTag(8);
         output.WriteEnum((int) Ctype);
       }
@@ -3622,7 +3589,7 @@ namespace Google.Protobuf.Reflection {
         output.WriteRawTag(40);
         output.WriteBool(Lazy);
       }
-      if (Jstype != global::Google.Protobuf.Reflection.FieldOptions.Types.JSType.JS_NORMAL) {
+      if (Jstype != 0) {
         output.WriteRawTag(48);
         output.WriteEnum((int) Jstype);
       }
@@ -3635,13 +3602,13 @@ namespace Google.Protobuf.Reflection {
 
     public int CalculateSize() {
       int size = 0;
-      if (Ctype != global::Google.Protobuf.Reflection.FieldOptions.Types.CType.STRING) {
+      if (Ctype != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Ctype);
       }
       if (Packed != false) {
         size += 1 + 1;
       }
-      if (Jstype != global::Google.Protobuf.Reflection.FieldOptions.Types.JSType.JS_NORMAL) {
+      if (Jstype != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Jstype);
       }
       if (Lazy != false) {
@@ -3661,13 +3628,13 @@ namespace Google.Protobuf.Reflection {
       if (other == null) {
         return;
       }
-      if (other.Ctype != global::Google.Protobuf.Reflection.FieldOptions.Types.CType.STRING) {
+      if (other.Ctype != 0) {
         Ctype = other.Ctype;
       }
       if (other.Packed != false) {
         Packed = other.Packed;
       }
-      if (other.Jstype != global::Google.Protobuf.Reflection.FieldOptions.Types.JSType.JS_NORMAL) {
+      if (other.Jstype != 0) {
         Jstype = other.Jstype;
       }
       if (other.Lazy != false) {
@@ -3729,24 +3696,24 @@ namespace Google.Protobuf.Reflection {
         /// <summary>
         ///  Default mode.
         /// </summary>
-        STRING = 0,
-        CORD = 1,
-        STRING_PIECE = 2,
+        [pbr::OriginalName("STRING")] String = 0,
+        [pbr::OriginalName("CORD")] Cord = 1,
+        [pbr::OriginalName("STRING_PIECE")] StringPiece = 2,
       }
 
       internal enum JSType {
         /// <summary>
         ///  Use the default type.
         /// </summary>
-        JS_NORMAL = 0,
+        [pbr::OriginalName("JS_NORMAL")] JsNormal = 0,
         /// <summary>
         ///  Use JavaScript strings.
         /// </summary>
-        JS_STRING = 1,
+        [pbr::OriginalName("JS_STRING")] JsString = 1,
         /// <summary>
         ///  Use JavaScript numbers.
         /// </summary>
-        JS_NUMBER = 2,
+        [pbr::OriginalName("JS_NUMBER")] JsNumber = 2,
       }
 
     }

csharp/src/Google.Protobuf/Reflection/FieldDescriptor.cs

@@ -30,9 +30,8 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
-using System;
-using System.Linq;
 using Google.Protobuf.Compatibility;
+using System;
 
 namespace Google.Protobuf.Reflection
 {
@@ -41,20 +40,35 @@ namespace Google.Protobuf.Reflection
     /// </summary>
     public sealed class FieldDescriptor : DescriptorBase, IComparable<FieldDescriptor>
     {
-        private readonly FieldDescriptorProto proto;
         private EnumDescriptor enumType;
         private MessageDescriptor messageType;
-        private readonly MessageDescriptor containingType;
-        private readonly OneofDescriptor containingOneof;
         private FieldType fieldType;
         private readonly string propertyName; // Annoyingly, needed in Crosslink.
         private IFieldAccessor accessor;
 
+        /// <summary>
+        /// Get the field's containing message type.
+        /// </summary>
+        public MessageDescriptor ContainingType { get; }
+
+        /// <summary>
+        /// Returns the oneof containing this field, or <c>null</c> if it is not part of a oneof.
+        /// </summary>
+        public OneofDescriptor ContainingOneof { get; }
+
+        /// <summary>
+        /// The effective JSON name for this field. This is usually the lower-camel-cased form of the field name,
+        /// but can be overridden using the <c>json_name</c> option in the .proto file.
+        /// </summary>
+        public string JsonName { get; }
+
+        internal FieldDescriptorProto Proto { get; }
+
         internal FieldDescriptor(FieldDescriptorProto proto, FileDescriptor file,
                                  MessageDescriptor parent, int index, string propertyName)
             : base(file, file.ComputeFullName(parent, proto.Name), index)
         {
-            this.proto = proto;
+            Proto = proto;
             if (proto.Type != 0)
             {
                 fieldType = GetFieldTypeFromProtoType(proto.Type);
@@ -64,7 +78,7 @@ namespace Google.Protobuf.Reflection
             {
                 throw new DescriptorValidationException(this, "Field numbers must be positive integers.");
             }
-            containingType = parent;
+            ContainingType = parent;
             // OneofIndex "defaults" to -1 due to a hack in FieldDescriptor.OnConstruction.
             if (proto.OneofIndex != -1)
             {
@@ -73,7 +87,7 @@ namespace Google.Protobuf.Reflection
                     throw new DescriptorValidationException(this,
                         $"FieldDescriptorProto.oneof_index is out of range for type {parent.Name}");
                 }
-                containingOneof = parent.Oneofs[proto.OneofIndex];
+                ContainingOneof = parent.Oneofs[proto.OneofIndex];
             }
 
             file.DescriptorPool.AddSymbol(this);
@@ -83,14 +97,14 @@ namespace Google.Protobuf.Reflection
             // We could trust the generated code and check whether the type of the property is
             // a MapField, but that feels a tad nasty.
             this.propertyName = propertyName;
+            JsonName =  Proto.JsonName == "" ? JsonFormatter.ToCamelCase(Proto.Name) : Proto.JsonName;
         }
+    
 
         /// <summary>
         /// The brief name of the descriptor's target.
         /// </summary>
-        public override string Name { get { return proto.Name; } }
-
-        internal FieldDescriptorProto Proto { get { return proto; } }
+        public override string Name => Proto.Name;
 
         /// <summary>
         /// Returns the accessor for this field.
@@ -110,7 +124,7 @@ namespace Google.Protobuf.Reflection
         /// and this property will return null.
         /// </para>
         /// </remarks>
-        public IFieldAccessor Accessor { get { return accessor; } }
+        public IFieldAccessor Accessor => accessor;
         
         /// <summary>
         /// Maps a field type as included in the .proto file to a FieldType.
@@ -119,41 +133,41 @@ namespace Google.Protobuf.Reflection
         {
             switch (type)
             {
-                case FieldDescriptorProto.Types.Type.TYPE_DOUBLE:
+                case FieldDescriptorProto.Types.Type.Double:
                     return FieldType.Double;
-                case FieldDescriptorProto.Types.Type.TYPE_FLOAT:
+                case FieldDescriptorProto.Types.Type.Float:
                     return FieldType.Float;
-                case FieldDescriptorProto.Types.Type.TYPE_INT64:
+                case FieldDescriptorProto.Types.Type.Int64:
                     return FieldType.Int64;
-                case FieldDescriptorProto.Types.Type.TYPE_UINT64:
+                case FieldDescriptorProto.Types.Type.Uint64:
                     return FieldType.UInt64;
-                case FieldDescriptorProto.Types.Type.TYPE_INT32:
+                case FieldDescriptorProto.Types.Type.Int32:
                     return FieldType.Int32;
-                case FieldDescriptorProto.Types.Type.TYPE_FIXED64:
+                case FieldDescriptorProto.Types.Type.Fixed64:
                     return FieldType.Fixed64;
-                case FieldDescriptorProto.Types.Type.TYPE_FIXED32:
+                case FieldDescriptorProto.Types.Type.Fixed32:
                     return FieldType.Fixed32;
-                case FieldDescriptorProto.Types.Type.TYPE_BOOL:
+                case FieldDescriptorProto.Types.Type.Bool:
                     return FieldType.Bool;
-                case FieldDescriptorProto.Types.Type.TYPE_STRING:
+                case FieldDescriptorProto.Types.Type.String:
                     return FieldType.String;
-                case FieldDescriptorProto.Types.Type.TYPE_GROUP:
+                case FieldDescriptorProto.Types.Type.Group:
                     return FieldType.Group;
-                case FieldDescriptorProto.Types.Type.TYPE_MESSAGE:
+                case FieldDescriptorProto.Types.Type.Message:
                     return FieldType.Message;
-                case FieldDescriptorProto.Types.Type.TYPE_BYTES:
+                case FieldDescriptorProto.Types.Type.Bytes:
                     return FieldType.Bytes;
-                case FieldDescriptorProto.Types.Type.TYPE_UINT32:
+                case FieldDescriptorProto.Types.Type.Uint32:
                     return FieldType.UInt32;
-                case FieldDescriptorProto.Types.Type.TYPE_ENUM:
+                case FieldDescriptorProto.Types.Type.Enum:
                     return FieldType.Enum;
-                case FieldDescriptorProto.Types.Type.TYPE_SFIXED32:
+                case FieldDescriptorProto.Types.Type.Sfixed32:
                     return FieldType.SFixed32;
-                case FieldDescriptorProto.Types.Type.TYPE_SFIXED64:
+                case FieldDescriptorProto.Types.Type.Sfixed64:
                     return FieldType.SFixed64;
-                case FieldDescriptorProto.Types.Type.TYPE_SINT32:
+                case FieldDescriptorProto.Types.Type.Sint32:
                     return FieldType.SInt32;
-                case FieldDescriptorProto.Types.Type.TYPE_SINT64:
+                case FieldDescriptorProto.Types.Type.Sint64:
                     return FieldType.SInt64;
                 default:
                     throw new ArgumentException("Invalid type specified");
@@ -163,62 +177,32 @@ namespace Google.Protobuf.Reflection
         /// <summary>
         /// Returns <c>true</c> if this field is a repeated field; <c>false</c> otherwise.
         /// </summary>
-        public bool IsRepeated
-        {
-            get { return Proto.Label == FieldDescriptorProto.Types.Label.LABEL_REPEATED; }
-        }
+        public bool IsRepeated => Proto.Label == FieldDescriptorProto.Types.Label.Repeated;
 
         /// <summary>
         /// Returns <c>true</c> if this field is a map field; <c>false</c> otherwise.
         /// </summary>
-        public bool IsMap
-        {
-            get { return fieldType == FieldType.Message && messageType.Proto.Options != null && messageType.Proto.Options.MapEntry; }
-        }
+        public bool IsMap => fieldType == FieldType.Message && messageType.Proto.Options != null && messageType.Proto.Options.MapEntry;
 
         /// <summary>
         /// Returns <c>true</c> if this field is a packed, repeated field; <c>false</c> otherwise.
         /// </summary>
-        public bool IsPacked
-        {
+        public bool IsPacked => 
             // Note the || rather than && here - we're effectively defaulting to packed, because that *is*
             // the default in proto3, which is all we support. We may give the wrong result for the protos
             // within descriptor.proto, but that's okay, as they're never exposed and we don't use IsPacked
             // within the runtime.
-            get { return Proto.Options == null || Proto.Options.Packed; }
-        }        
-
-        /// <summary>
-        /// Get the field's containing message type.
-        /// </summary>
-        public MessageDescriptor ContainingType
-        {
-            get { return containingType; }
-        }
-
-        /// <summary>
-        /// Returns the oneof containing this field, or <c>null</c> if it is not part of a oneof.
-        /// </summary>
-        public OneofDescriptor ContainingOneof
-        {
-            get { return containingOneof; }
-        }
-
+            Proto.Options == null || Proto.Options.Packed;
+        
         /// <summary>
         /// Returns the type of the field.
         /// </summary>
-        public FieldType FieldType
-        {
-            get { return fieldType; }
-        }
+        public FieldType FieldType => fieldType;
 
         /// <summary>
         /// Returns the field number declared in the proto file.
         /// </summary>
-        public int FieldNumber
-        {
-            get { return Proto.Number; }
-        }
+        public int FieldNumber => Proto.Number;
 
         /// <summary>
         /// Compares this descriptor with another one, ordering in "canonical" order
@@ -228,7 +212,7 @@ namespace Google.Protobuf.Reflection
         /// </summary>
         public int CompareTo(FieldDescriptor other)
         {
-            if (other.containingType != containingType)
+            if (other.ContainingType != ContainingType)
             {
                 throw new ArgumentException("FieldDescriptors can only be compared to other FieldDescriptors " +
                                             "for fields of the same message type.");
@@ -331,14 +315,14 @@ namespace Google.Protobuf.Reflection
 
             File.DescriptorPool.AddFieldByNumber(this);
 
-            if (containingType != null && containingType.Proto.Options != null && containingType.Proto.Options.MessageSetWireFormat)
+            if (ContainingType != null && ContainingType.Proto.Options != null && ContainingType.Proto.Options.MessageSetWireFormat)
             {
                 throw new DescriptorValidationException(this, "MessageSet format is not supported.");
             }
-            accessor = CreateAccessor(propertyName);
+            accessor = CreateAccessor();
         }
 
-        private IFieldAccessor CreateAccessor(string propertyName)
+        private IFieldAccessor CreateAccessor()
         {
             // If we're given no property name, that's because we really don't want an accessor.
             // (At the moment, that means it's a map entry message...)
@@ -346,10 +330,10 @@ namespace Google.Protobuf.Reflection
             {
                 return null;
             }
-            var property = containingType.ClrType.GetProperty(propertyName);
+            var property = ContainingType.ClrType.GetProperty(propertyName);
             if (property == null)
             {
-                throw new DescriptorValidationException(this, $"Property {propertyName} not found in {containingType.ClrType}");
+                throw new DescriptorValidationException(this, $"Property {propertyName} not found in {ContainingType.ClrType}");
             }
             return IsMap ? new MapFieldAccessor(property, this)
                 : IsRepeated ? new RepeatedFieldAccessor(property, this)

csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs

@@ -102,8 +102,8 @@ namespace Google.Protobuf.Reflection
             var map = new Dictionary<string, FieldDescriptor>();
             foreach (var field in fields)
             {
-                map[JsonFormatter.ToCamelCase(field.Name)] = field;
                 map[field.Name] = field;
+                map[field.JsonName] = field;
             }
             return new ReadOnlyDictionary<string, FieldDescriptor>(map);
         }

csharp/src/Google.Protobuf/Reflection/OriginalNameAttribute.cs

@@ -0,0 +1,58 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Specifies the original name (in the .proto file) of a named element,
+    /// such as an enum value.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Field)]
+    public class OriginalNameAttribute : Attribute
+    {
+        /// <summary>
+        /// The name of the element in the .proto file.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Constructs a new attribute instance for the given name.
+        /// </summary>
+        /// <param name="name">The name of the element in the .proto file.</param>
+        public OriginalNameAttribute(string name)
+        {
+            Name = ProtoPreconditions.CheckNotNull(name, nameof(name));
+        }
+    }
+}

csharp/src/Google.Protobuf/WellKnownTypes/Any.cs

@@ -24,9 +24,10 @@ namespace Google.Protobuf.WellKnownTypes {
       byte[] descriptorData = global::System.Convert.FromBase64String(
           string.Concat(
             "Chlnb29nbGUvcHJvdG9idWYvYW55LnByb3RvEg9nb29nbGUucHJvdG9idWYi",
-            "JgoDQW55EhAKCHR5cGVfdXJsGAEgASgJEg0KBXZhbHVlGAIgASgMQksKE2Nv",
-            "bS5nb29nbGUucHJvdG9idWZCCEFueVByb3RvUAGgAQGiAgNHUEKqAh5Hb29n",
-            "bGUuUHJvdG9idWYuV2VsbEtub3duVHlwZXNiBnByb3RvMw=="));
+            "JgoDQW55EhAKCHR5cGVfdXJsGAEgASgJEg0KBXZhbHVlGAIgASgMQnIKE2Nv",
+            "bS5nb29nbGUucHJvdG9idWZCCEFueVByb3RvUAFaJWdpdGh1Yi5jb20vZ29s",
+            "YW5nL3Byb3RvYnVmL3B0eXBlcy9hbnmgAQGiAgNHUEKqAh5Hb29nbGUuUHJv",
+            "dG9idWYuV2VsbEtub3duVHlwZXNiBnByb3RvMw=="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
@@ -38,8 +39,36 @@ namespace Google.Protobuf.WellKnownTypes {
   }
   #region Messages
   /// <summary>
-  ///  `Any` contains an arbitrary serialized message along with a URL
-  ///  that describes the type of the serialized message.
+  ///  `Any` contains an arbitrary serialized protocol buffer message along with a
+  ///  URL that describes the type of the serialized message.
+  ///
+  ///  Protobuf library provides support to pack/unpack Any values in the form
+  ///  of utility functions or additional generated methods of the Any type.
+  ///
+  ///  Example 1: Pack and unpack a message in C++.
+  ///
+  ///      Foo foo = ...;
+  ///      Any any;
+  ///      any.PackFrom(foo);
+  ///      ...
+  ///      if (any.UnpackTo(&amp;foo)) {
+  ///        ...
+  ///      }
+  ///
+  ///  Example 2: Pack and unpack a message in Java.
+  ///
+  ///      Foo foo = ...;
+  ///      Any any = Any.pack(foo);
+  ///      ...
+  ///      if (any.is(Foo.class)) {
+  ///        foo = any.unpack(Foo.class);
+  ///      }
+  ///
+  ///  The pack methods provided by protobuf library will by default use
+  ///  'type.googleapis.com/full.type.name' as the type URL and the unpack
+  ///  methods only use the fully qualified type name after the last '/'
+  ///  in the type URL, for example "foo.bar.com/x/y.z" will yield type
+  ///  name "y.z".
   ///
   ///  JSON
   ///  ====
@@ -102,7 +131,7 @@ namespace Google.Protobuf.WellKnownTypes {
     private string typeUrl_ = "";
     /// <summary>
     ///  A URL/resource name whose content describes the type of the
-    ///  serialized message.
+    ///  serialized protocol buffer message.
     ///
     ///  For URLs which use the schema `http`, `https`, or no schema, the
     ///  following restrictions and interpretations apply:
@@ -110,6 +139,8 @@ namespace Google.Protobuf.WellKnownTypes {
     ///  * If no schema is provided, `https` is assumed.
     ///  * The last segment of the URL's path must represent the fully
     ///    qualified name of the type (as in `path/google.protobuf.Duration`).
+    ///    The name should be in a canonical form (e.g., leading "." is
+    ///    not accepted).
     ///  * An HTTP GET on the URL must yield a [google.protobuf.Type][]
     ///    value in binary format, or produce an error.
     ///  * Applications are allowed to cache lookup results based on the
@@ -132,7 +163,7 @@ namespace Google.Protobuf.WellKnownTypes {
     public const int ValueFieldNumber = 2;
     private pb::ByteString value_ = pb::ByteString.Empty;
     /// <summary>
-    ///  Must be valid serialized data of the above specified type.
+    ///  Must be a valid serialized protocol buffer of the above specified type.
     /// </summary>
     public pb::ByteString Value {
       get { return value_; }

csharp/src/Google.Protobuf/WellKnownTypes/AnyPartial.cs

@@ -36,11 +36,27 @@ namespace Google.Protobuf.WellKnownTypes
 {
     public partial class Any
     {
+        private const string DefaultPrefix = "type.googleapis.com";
+
         // This could be moved to MessageDescriptor if we wanted to, but keeping it here means
         // all the Any-specific code is in the same place.
-        private static string GetTypeUrl(MessageDescriptor descriptor)
+        private static string GetTypeUrl(MessageDescriptor descriptor, string prefix) =>
+            prefix.EndsWith("/") ? prefix + descriptor.FullName : prefix + "/" + descriptor.FullName;
+
+        /// <summary>
+        /// Retrieves the type name for a type URL. This is always just the last part of the URL,
+        /// after the trailing slash. No validation of anything before the trailing slash is performed.
+        /// If the type URL does not include a slash, an empty string is returned rather than an exception
+        /// being thrown; this won't match any types, and the calling code is probably in a better position
+        /// to give a meaningful error.
+        /// There is no handling of fragments or queries  at the moment.
+        /// </summary>
+        /// <param name="typeUrl">The URL to extract the type name from</param>
+        /// <returns>The type name</returns>
+        internal static string GetTypeName(string typeUrl)
         {
-            return "type.googleapis.com/" + descriptor.FullName;
+            int lastSlash = typeUrl.LastIndexOf('/');
+            return lastSlash == -1 ? "" : typeUrl.Substring(lastSlash + 1);
         }
 
         /// <summary>
@@ -55,25 +71,37 @@ namespace Google.Protobuf.WellKnownTypes
             // Note: this doesn't perform as well is it might. We could take a MessageParser<T> in an alternative overload,
             // which would be expected to perform slightly better... although the difference is likely to be negligible.
             T target = new T();
-            string targetTypeUrl = GetTypeUrl(target.Descriptor);
-            if (TypeUrl != targetTypeUrl)
+            if (GetTypeName(TypeUrl) != target.Descriptor.FullName)
             {
-                throw new InvalidProtocolBufferException(string.Format("Type url for {0} is {1}; Any message's type url is {2}",
-                    target.Descriptor.Name, targetTypeUrl, TypeUrl));
+                throw new InvalidProtocolBufferException(
+                    $"Full type name for {target.Descriptor.Name} is {target.Descriptor.FullName}; Any message's type url is {TypeUrl}");
             }
             target.MergeFrom(Value);
             return target;
         }
 
         /// <summary>
-        /// Packs the specified message into an Any message.
+        /// Packs the specified message into an Any message using a type URL prefix of "type.googleapis.com".
+        /// </summary>
+        /// <param name="message">The message to pack.</param>
+        /// <returns>An Any message with the content and type URL of <paramref name="message"/>.</returns>
+        public static Any Pack(IMessage message) => Pack(message, DefaultPrefix);
+
+        /// <summary>
+        /// Packs the specified message into an Any message using the specified type URL prefix.
         /// </summary>
         /// <param name="message">The message to pack.</param>
+        /// <param name="typeUrlPrefix">The prefix for the type URL.</param>
         /// <returns>An Any message with the content and type URL of <paramref name="message"/>.</returns>
-        public static Any Pack(IMessage message)
+        public static Any Pack(IMessage message, string typeUrlPrefix)
         {
-            ProtoPreconditions.CheckNotNull(message, "message");
-            return new Any { TypeUrl = GetTypeUrl(message.Descriptor), Value = message.ToByteString() };
+            ProtoPreconditions.CheckNotNull(message, nameof(message));
+            ProtoPreconditions.CheckNotNull(typeUrlPrefix, nameof(typeUrlPrefix));
+            return new Any
+            {
+                TypeUrl = GetTypeUrl(message.Descriptor, typeUrlPrefix),
+                Value = message.ToByteString()
+            };
         }
     }
 }

csharp/src/Google.Protobuf/WellKnownTypes/Api.cs

@@ -185,7 +185,7 @@ namespace Google.Protobuf.WellKnownTypes {
 
     /// <summary>Field number for the "syntax" field.</summary>
     public const int SyntaxFieldNumber = 7;
-    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2;
+    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = 0;
     /// <summary>
     ///  The source syntax of the service.
     /// </summary>
@@ -225,7 +225,7 @@ namespace Google.Protobuf.WellKnownTypes {
       if (Version.Length != 0) hash ^= Version.GetHashCode();
       if (sourceContext_ != null) hash ^= SourceContext.GetHashCode();
       hash ^= mixins_.GetHashCode();
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) hash ^= Syntax.GetHashCode();
+      if (Syntax != 0) hash ^= Syntax.GetHashCode();
       return hash;
     }
 
@@ -249,7 +249,7 @@ namespace Google.Protobuf.WellKnownTypes {
         output.WriteMessage(SourceContext);
       }
       mixins_.WriteTo(output, _repeated_mixins_codec);
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         output.WriteRawTag(56);
         output.WriteEnum((int) Syntax);
       }
@@ -269,7 +269,7 @@ namespace Google.Protobuf.WellKnownTypes {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(SourceContext);
       }
       size += mixins_.CalculateSize(_repeated_mixins_codec);
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Syntax);
       }
       return size;
@@ -294,7 +294,7 @@ namespace Google.Protobuf.WellKnownTypes {
         SourceContext.MergeFrom(other.SourceContext);
       }
       mixins_.Add(other.mixins_);
-      if (other.Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (other.Syntax != 0) {
         Syntax = other.Syntax;
       }
     }
@@ -458,7 +458,7 @@ namespace Google.Protobuf.WellKnownTypes {
 
     /// <summary>Field number for the "syntax" field.</summary>
     public const int SyntaxFieldNumber = 7;
-    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2;
+    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = 0;
     /// <summary>
     ///  The source syntax of this method.
     /// </summary>
@@ -498,7 +498,7 @@ namespace Google.Protobuf.WellKnownTypes {
       if (ResponseTypeUrl.Length != 0) hash ^= ResponseTypeUrl.GetHashCode();
       if (ResponseStreaming != false) hash ^= ResponseStreaming.GetHashCode();
       hash ^= options_.GetHashCode();
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) hash ^= Syntax.GetHashCode();
+      if (Syntax != 0) hash ^= Syntax.GetHashCode();
       return hash;
     }
 
@@ -528,7 +528,7 @@ namespace Google.Protobuf.WellKnownTypes {
         output.WriteBool(ResponseStreaming);
       }
       options_.WriteTo(output, _repeated_options_codec);
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         output.WriteRawTag(56);
         output.WriteEnum((int) Syntax);
       }
@@ -552,7 +552,7 @@ namespace Google.Protobuf.WellKnownTypes {
         size += 1 + 1;
       }
       size += options_.CalculateSize(_repeated_options_codec);
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Syntax);
       }
       return size;
@@ -578,7 +578,7 @@ namespace Google.Protobuf.WellKnownTypes {
         ResponseStreaming = other.ResponseStreaming;
       }
       options_.Add(other.options_);
-      if (other.Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (other.Syntax != 0) {
         Syntax = other.Syntax;
       }
     }

csharp/src/Google.Protobuf/WellKnownTypes/Duration.cs

@@ -25,9 +25,10 @@ namespace Google.Protobuf.WellKnownTypes {
           string.Concat(
             "Ch5nb29nbGUvcHJvdG9idWYvZHVyYXRpb24ucHJvdG8SD2dvb2dsZS5wcm90",
             "b2J1ZiIqCghEdXJhdGlvbhIPCgdzZWNvbmRzGAEgASgDEg0KBW5hbm9zGAIg",
-            "ASgFQlAKE2NvbS5nb29nbGUucHJvdG9idWZCDUR1cmF0aW9uUHJvdG9QAaAB",
-            "AaICA0dQQqoCHkdvb2dsZS5Qcm90b2J1Zi5XZWxsS25vd25UeXBlc2IGcHJv",
-            "dG8z"));
+            "ASgFQnwKE2NvbS5nb29nbGUucHJvdG9idWZCDUR1cmF0aW9uUHJvdG9QAVoq",
+            "Z2l0aHViLmNvbS9nb2xhbmcvcHJvdG9idWYvcHR5cGVzL2R1cmF0aW9uoAEB",
+            "ogIDR1BCqgIeR29vZ2xlLlByb3RvYnVmLldlbGxLbm93blR5cGVzYgZwcm90",
+            "bzM="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {

csharp/src/Google.Protobuf/WellKnownTypes/Empty.cs

@@ -24,9 +24,10 @@ namespace Google.Protobuf.WellKnownTypes {
       byte[] descriptorData = global::System.Convert.FromBase64String(
           string.Concat(
             "Chtnb29nbGUvcHJvdG9idWYvZW1wdHkucHJvdG8SD2dvb2dsZS5wcm90b2J1",
-            "ZiIHCgVFbXB0eUJQChNjb20uZ29vZ2xlLnByb3RvYnVmQgpFbXB0eVByb3Rv",
-            "UAGgAQH4AQGiAgNHUEKqAh5Hb29nbGUuUHJvdG9idWYuV2VsbEtub3duVHlw",
-            "ZXNiBnByb3RvMw=="));
+            "ZiIHCgVFbXB0eUJ5ChNjb20uZ29vZ2xlLnByb3RvYnVmQgpFbXB0eVByb3Rv",
+            "UAFaJ2dpdGh1Yi5jb20vZ29sYW5nL3Byb3RvYnVmL3B0eXBlcy9lbXB0eaAB",
+            "AfgBAaICA0dQQqoCHkdvb2dsZS5Qcm90b2J1Zi5XZWxsS25vd25UeXBlc2IG",
+            "cHJvdG8z"));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {

csharp/src/Google.Protobuf/WellKnownTypes/FieldMask.cs

@@ -86,7 +86,7 @@ namespace Google.Protobuf.WellKnownTypes {
   ///  operation applies to all fields (as if a FieldMask of all fields
   ///  had been specified).
   ///
-  ///  Note that a field mask does not necessarily applies to the
+  ///  Note that a field mask does not necessarily apply to the
   ///  top-level response message. In case of a REST get operation, the
   ///  field mask applies directly to the response, but in case of a REST
   ///  list operation, the mask instead applies to each individual message
@@ -159,6 +159,33 @@ namespace Google.Protobuf.WellKnownTypes {
   ///      {
   ///        mask: "user.displayName,photo"
   ///      }
+  ///
+  ///  # Field Masks and Oneof Fields
+  ///
+  ///  Field masks treat fields in oneofs just as regular fields. Consider the
+  ///  following message:
+  ///
+  ///      message SampleMessage {
+  ///        oneof test_oneof {
+  ///          string name = 4;
+  ///          SubMessage sub_message = 9;
+  ///        }
+  ///      }
+  ///
+  ///  The field mask can be:
+  ///
+  ///      mask {
+  ///        paths: "name"
+  ///      }
+  ///
+  ///  Or:
+  ///
+  ///      mask {
+  ///        paths: "sub_message"
+  ///      }
+  ///
+  ///  Note that oneof type names ("test_oneof" in this case) cannot be used in
+  ///  paths.
   /// </summary>
   [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
   public sealed partial class FieldMask : pb::IMessage<FieldMask> {

csharp/src/Google.Protobuf/WellKnownTypes/Struct.cs

@@ -34,9 +34,10 @@ namespace Google.Protobuf.WellKnownTypes {
             "ABIwCgpsaXN0X3ZhbHVlGAYgASgLMhouZ29vZ2xlLnByb3RvYnVmLkxpc3RW",
             "YWx1ZUgAQgYKBGtpbmQiMwoJTGlzdFZhbHVlEiYKBnZhbHVlcxgBIAMoCzIW",
             "Lmdvb2dsZS5wcm90b2J1Zi5WYWx1ZSobCglOdWxsVmFsdWUSDgoKTlVMTF9W",
-            "QUxVRRAAQk4KE2NvbS5nb29nbGUucHJvdG9idWZCC1N0cnVjdFByb3RvUAGg",
-            "AQGiAgNHUEKqAh5Hb29nbGUuUHJvdG9idWYuV2VsbEtub3duVHlwZXNiBnBy",
-            "b3RvMw=="));
+            "QUxVRRAAQoEBChNjb20uZ29vZ2xlLnByb3RvYnVmQgtTdHJ1Y3RQcm90b1AB",
+            "WjFnaXRodWIuY29tL2dvbGFuZy9wcm90b2J1Zi9wdHlwZXMvc3RydWN0O3N0",
+            "cnVjdHBioAEBogIDR1BCqgIeR29vZ2xlLlByb3RvYnVmLldlbGxLbm93blR5",
+            "cGVzYgZwcm90bzM="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(new[] {typeof(global::Google.Protobuf.WellKnownTypes.NullValue), }, new pbr::GeneratedClrTypeInfo[] {
@@ -59,7 +60,7 @@ namespace Google.Protobuf.WellKnownTypes {
     /// <summary>
     ///  Null value.
     /// </summary>
-    NULL_VALUE = 0,
+    [pbr::OriginalName("NULL_VALUE")] NullValue = 0,
   }
 
   #endregion
@@ -108,7 +109,7 @@ namespace Google.Protobuf.WellKnownTypes {
         = new pbc::MapField<string, global::Google.Protobuf.WellKnownTypes.Value>.Codec(pb::FieldCodec.ForString(10), pb::FieldCodec.ForMessage(18, global::Google.Protobuf.WellKnownTypes.Value.Parser), 10);
     private readonly pbc::MapField<string, global::Google.Protobuf.WellKnownTypes.Value> fields_ = new pbc::MapField<string, global::Google.Protobuf.WellKnownTypes.Value>();
     /// <summary>
-    ///  Map of dynamically typed values.
+    ///  Unordered map of dynamically typed values.
     /// </summary>
     public pbc::MapField<string, global::Google.Protobuf.WellKnownTypes.Value> Fields {
       get { return fields_; }
@@ -234,7 +235,7 @@ namespace Google.Protobuf.WellKnownTypes {
     ///  Represents a null value.
     /// </summary>
     public global::Google.Protobuf.WellKnownTypes.NullValue NullValue {
-      get { return kindCase_ == KindOneofCase.NullValue ? (global::Google.Protobuf.WellKnownTypes.NullValue) kind_ : global::Google.Protobuf.WellKnownTypes.NullValue.NULL_VALUE; }
+      get { return kindCase_ == KindOneofCase.NullValue ? (global::Google.Protobuf.WellKnownTypes.NullValue) kind_ : 0; }
       set {
         kind_ = value;
         kindCase_ = KindOneofCase.NullValue;

csharp/src/Google.Protobuf/WellKnownTypes/Timestamp.cs

@@ -25,9 +25,10 @@ namespace Google.Protobuf.WellKnownTypes {
           string.Concat(
             "Ch9nb29nbGUvcHJvdG9idWYvdGltZXN0YW1wLnByb3RvEg9nb29nbGUucHJv",
             "dG9idWYiKwoJVGltZXN0YW1wEg8KB3NlY29uZHMYASABKAMSDQoFbmFub3MY",
-            "AiABKAVCVAoTY29tLmdvb2dsZS5wcm90b2J1ZkIOVGltZXN0YW1wUHJvdG9Q",
-            "AaABAfgBAaICA0dQQqoCHkdvb2dsZS5Qcm90b2J1Zi5XZWxsS25vd25UeXBl",
-            "c2IGcHJvdG8z"));
+            "AiABKAVCgQEKE2NvbS5nb29nbGUucHJvdG9idWZCDlRpbWVzdGFtcFByb3Rv",
+            "UAFaK2dpdGh1Yi5jb20vZ29sYW5nL3Byb3RvYnVmL3B0eXBlcy90aW1lc3Rh",
+            "bXCgAQH4AQGiAgNHUEKqAh5Hb29nbGUuUHJvdG9idWYuV2VsbEtub3duVHlw",
+            "ZXNiBnByb3RvMw=="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {

csharp/src/Google.Protobuf/WellKnownTypes/Type.cs

@@ -79,11 +79,11 @@ namespace Google.Protobuf.WellKnownTypes {
     /// <summary>
     ///  Syntax `proto2`.
     /// </summary>
-    SYNTAX_PROTO2 = 0,
+    [pbr::OriginalName("SYNTAX_PROTO2")] Proto2 = 0,
     /// <summary>
     ///  Syntax `proto3`.
     /// </summary>
-    SYNTAX_PROTO3 = 1,
+    [pbr::OriginalName("SYNTAX_PROTO3")] Proto3 = 1,
   }
 
   #endregion
@@ -188,7 +188,7 @@ namespace Google.Protobuf.WellKnownTypes {
 
     /// <summary>Field number for the "syntax" field.</summary>
     public const int SyntaxFieldNumber = 6;
-    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2;
+    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = 0;
     /// <summary>
     ///  The source syntax.
     /// </summary>
@@ -226,7 +226,7 @@ namespace Google.Protobuf.WellKnownTypes {
       hash ^= oneofs_.GetHashCode();
       hash ^= options_.GetHashCode();
       if (sourceContext_ != null) hash ^= SourceContext.GetHashCode();
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) hash ^= Syntax.GetHashCode();
+      if (Syntax != 0) hash ^= Syntax.GetHashCode();
       return hash;
     }
 
@@ -246,7 +246,7 @@ namespace Google.Protobuf.WellKnownTypes {
         output.WriteRawTag(42);
         output.WriteMessage(SourceContext);
       }
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         output.WriteRawTag(48);
         output.WriteEnum((int) Syntax);
       }
@@ -263,7 +263,7 @@ namespace Google.Protobuf.WellKnownTypes {
       if (sourceContext_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(SourceContext);
       }
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Syntax);
       }
       return size;
@@ -285,7 +285,7 @@ namespace Google.Protobuf.WellKnownTypes {
         }
         SourceContext.MergeFrom(other.SourceContext);
       }
-      if (other.Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (other.Syntax != 0) {
         Syntax = other.Syntax;
       }
     }
@@ -371,7 +371,7 @@ namespace Google.Protobuf.WellKnownTypes {
 
     /// <summary>Field number for the "kind" field.</summary>
     public const int KindFieldNumber = 1;
-    private global::Google.Protobuf.WellKnownTypes.Field.Types.Kind kind_ = global::Google.Protobuf.WellKnownTypes.Field.Types.Kind.TYPE_UNKNOWN;
+    private global::Google.Protobuf.WellKnownTypes.Field.Types.Kind kind_ = 0;
     /// <summary>
     ///  The field type.
     /// </summary>
@@ -384,7 +384,7 @@ namespace Google.Protobuf.WellKnownTypes {
 
     /// <summary>Field number for the "cardinality" field.</summary>
     public const int CardinalityFieldNumber = 2;
-    private global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality cardinality_ = global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality.CARDINALITY_UNKNOWN;
+    private global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality cardinality_ = 0;
     /// <summary>
     ///  The field cardinality.
     /// </summary>
@@ -526,8 +526,8 @@ namespace Google.Protobuf.WellKnownTypes {
 
     public override int GetHashCode() {
       int hash = 1;
-      if (Kind != global::Google.Protobuf.WellKnownTypes.Field.Types.Kind.TYPE_UNKNOWN) hash ^= Kind.GetHashCode();
-      if (Cardinality != global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality.CARDINALITY_UNKNOWN) hash ^= Cardinality.GetHashCode();
+      if (Kind != 0) hash ^= Kind.GetHashCode();
+      if (Cardinality != 0) hash ^= Cardinality.GetHashCode();
       if (Number != 0) hash ^= Number.GetHashCode();
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (TypeUrl.Length != 0) hash ^= TypeUrl.GetHashCode();
@@ -544,11 +544,11 @@ namespace Google.Protobuf.WellKnownTypes {
     }
 
     public void WriteTo(pb::CodedOutputStream output) {
-      if (Kind != global::Google.Protobuf.WellKnownTypes.Field.Types.Kind.TYPE_UNKNOWN) {
+      if (Kind != 0) {
         output.WriteRawTag(8);
         output.WriteEnum((int) Kind);
       }
-      if (Cardinality != global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality.CARDINALITY_UNKNOWN) {
+      if (Cardinality != 0) {
         output.WriteRawTag(16);
         output.WriteEnum((int) Cardinality);
       }
@@ -585,10 +585,10 @@ namespace Google.Protobuf.WellKnownTypes {
 
     public int CalculateSize() {
       int size = 0;
-      if (Kind != global::Google.Protobuf.WellKnownTypes.Field.Types.Kind.TYPE_UNKNOWN) {
+      if (Kind != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Kind);
       }
-      if (Cardinality != global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality.CARDINALITY_UNKNOWN) {
+      if (Cardinality != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Cardinality);
       }
       if (Number != 0) {
@@ -620,10 +620,10 @@ namespace Google.Protobuf.WellKnownTypes {
       if (other == null) {
         return;
       }
-      if (other.Kind != global::Google.Protobuf.WellKnownTypes.Field.Types.Kind.TYPE_UNKNOWN) {
+      if (other.Kind != 0) {
         Kind = other.Kind;
       }
-      if (other.Cardinality != global::Google.Protobuf.WellKnownTypes.Field.Types.Cardinality.CARDINALITY_UNKNOWN) {
+      if (other.Cardinality != 0) {
         Cardinality = other.Cardinality;
       }
       if (other.Number != 0) {
@@ -712,79 +712,79 @@ namespace Google.Protobuf.WellKnownTypes {
         /// <summary>
         ///  Field type unknown.
         /// </summary>
-        TYPE_UNKNOWN = 0,
+        [pbr::OriginalName("TYPE_UNKNOWN")] TypeUnknown = 0,
         /// <summary>
         ///  Field type double.
         /// </summary>
-        TYPE_DOUBLE = 1,
+        [pbr::OriginalName("TYPE_DOUBLE")] TypeDouble = 1,
         /// <summary>
         ///  Field type float.
         /// </summary>
-        TYPE_FLOAT = 2,
+        [pbr::OriginalName("TYPE_FLOAT")] TypeFloat = 2,
         /// <summary>
         ///  Field type int64.
         /// </summary>
-        TYPE_INT64 = 3,
+        [pbr::OriginalName("TYPE_INT64")] TypeInt64 = 3,
         /// <summary>
         ///  Field type uint64.
         /// </summary>
-        TYPE_UINT64 = 4,
+        [pbr::OriginalName("TYPE_UINT64")] TypeUint64 = 4,
         /// <summary>
         ///  Field type int32.
         /// </summary>
-        TYPE_INT32 = 5,
+        [pbr::OriginalName("TYPE_INT32")] TypeInt32 = 5,
         /// <summary>
         ///  Field type fixed64.
         /// </summary>
-        TYPE_FIXED64 = 6,
+        [pbr::OriginalName("TYPE_FIXED64")] TypeFixed64 = 6,
         /// <summary>
         ///  Field type fixed32.
         /// </summary>
-        TYPE_FIXED32 = 7,
+        [pbr::OriginalName("TYPE_FIXED32")] TypeFixed32 = 7,
         /// <summary>
         ///  Field type bool.
         /// </summary>
-        TYPE_BOOL = 8,
+        [pbr::OriginalName("TYPE_BOOL")] TypeBool = 8,
         /// <summary>
         ///  Field type string.
         /// </summary>
-        TYPE_STRING = 9,
+        [pbr::OriginalName("TYPE_STRING")] TypeString = 9,
         /// <summary>
         ///  Field type group. Proto2 syntax only, and deprecated.
         /// </summary>
-        TYPE_GROUP = 10,
+        [pbr::OriginalName("TYPE_GROUP")] TypeGroup = 10,
         /// <summary>
         ///  Field type message.
         /// </summary>
-        TYPE_MESSAGE = 11,
+        [pbr::OriginalName("TYPE_MESSAGE")] TypeMessage = 11,
         /// <summary>
         ///  Field type bytes.
         /// </summary>
-        TYPE_BYTES = 12,
+        [pbr::OriginalName("TYPE_BYTES")] TypeBytes = 12,
         /// <summary>
         ///  Field type uint32.
         /// </summary>
-        TYPE_UINT32 = 13,
+        [pbr::OriginalName("TYPE_UINT32")] TypeUint32 = 13,
         /// <summary>
         ///  Field type enum.
         /// </summary>
-        TYPE_ENUM = 14,
+        [pbr::OriginalName("TYPE_ENUM")] TypeEnum = 14,
         /// <summary>
         ///  Field type sfixed32.
         /// </summary>
-        TYPE_SFIXED32 = 15,
+        [pbr::OriginalName("TYPE_SFIXED32")] TypeSfixed32 = 15,
         /// <summary>
         ///  Field type sfixed64.
         /// </summary>
-        TYPE_SFIXED64 = 16,
+        [pbr::OriginalName("TYPE_SFIXED64")] TypeSfixed64 = 16,
         /// <summary>
         ///  Field type sint32.
         /// </summary>
-        TYPE_SINT32 = 17,
+        [pbr::OriginalName("TYPE_SINT32")] TypeSint32 = 17,
         /// <summary>
         ///  Field type sint64.
         /// </summary>
-        TYPE_SINT64 = 18,
+        [pbr::OriginalName("TYPE_SINT64")] TypeSint64 = 18,
       }
 
       /// <summary>
@@ -794,19 +794,19 @@ namespace Google.Protobuf.WellKnownTypes {
         /// <summary>
         ///  For fields with unknown cardinality.
         /// </summary>
-        CARDINALITY_UNKNOWN = 0,
+        [pbr::OriginalName("CARDINALITY_UNKNOWN")] Unknown = 0,
         /// <summary>
         ///  For optional fields.
         /// </summary>
-        CARDINALITY_OPTIONAL = 1,
+        [pbr::OriginalName("CARDINALITY_OPTIONAL")] Optional = 1,
         /// <summary>
         ///  For required fields. Proto2 syntax only.
         /// </summary>
-        CARDINALITY_REQUIRED = 2,
+        [pbr::OriginalName("CARDINALITY_REQUIRED")] Required = 2,
         /// <summary>
         ///  For repeated fields.
         /// </summary>
-        CARDINALITY_REPEATED = 3,
+        [pbr::OriginalName("CARDINALITY_REPEATED")] Repeated = 3,
       }
 
     }
@@ -900,7 +900,7 @@ namespace Google.Protobuf.WellKnownTypes {
 
     /// <summary>Field number for the "syntax" field.</summary>
     public const int SyntaxFieldNumber = 5;
-    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2;
+    private global::Google.Protobuf.WellKnownTypes.Syntax syntax_ = 0;
     /// <summary>
     ///  The source syntax.
     /// </summary>
@@ -936,7 +936,7 @@ namespace Google.Protobuf.WellKnownTypes {
       hash ^= enumvalue_.GetHashCode();
       hash ^= options_.GetHashCode();
       if (sourceContext_ != null) hash ^= SourceContext.GetHashCode();
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) hash ^= Syntax.GetHashCode();
+      if (Syntax != 0) hash ^= Syntax.GetHashCode();
       return hash;
     }
 
@@ -955,7 +955,7 @@ namespace Google.Protobuf.WellKnownTypes {
         output.WriteRawTag(34);
         output.WriteMessage(SourceContext);
       }
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         output.WriteRawTag(40);
         output.WriteEnum((int) Syntax);
       }
@@ -971,7 +971,7 @@ namespace Google.Protobuf.WellKnownTypes {
       if (sourceContext_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(SourceContext);
       }
-      if (Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (Syntax != 0) {
         size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Syntax);
       }
       return size;
@@ -992,7 +992,7 @@ namespace Google.Protobuf.WellKnownTypes {
         }
         SourceContext.MergeFrom(other.SourceContext);
       }
-      if (other.Syntax != global::Google.Protobuf.WellKnownTypes.Syntax.SYNTAX_PROTO2) {
+      if (other.Syntax != 0) {
         Syntax = other.Syntax;
       }
     }

csharp/src/Google.Protobuf/WellKnownTypes/Wrappers.cs

@@ -29,10 +29,10 @@ namespace Google.Protobuf.WellKnownTypes {
             "KAMiHAoLVUludDY0VmFsdWUSDQoFdmFsdWUYASABKAQiGwoKSW50MzJWYWx1",
             "ZRINCgV2YWx1ZRgBIAEoBSIcCgtVSW50MzJWYWx1ZRINCgV2YWx1ZRgBIAEo",
             "DSIaCglCb29sVmFsdWUSDQoFdmFsdWUYASABKAgiHAoLU3RyaW5nVmFsdWUS",
-            "DQoFdmFsdWUYASABKAkiGwoKQnl0ZXNWYWx1ZRINCgV2YWx1ZRgBIAEoDEJT",
-            "ChNjb20uZ29vZ2xlLnByb3RvYnVmQg1XcmFwcGVyc1Byb3RvUAGgAQH4AQGi",
-            "AgNHUEKqAh5Hb29nbGUuUHJvdG9idWYuV2VsbEtub3duVHlwZXNiBnByb3Rv",
-            "Mw=="));
+            "DQoFdmFsdWUYASABKAkiGwoKQnl0ZXNWYWx1ZRINCgV2YWx1ZRgBIAEoDEJ/",
+            "ChNjb20uZ29vZ2xlLnByb3RvYnVmQg1XcmFwcGVyc1Byb3RvUAFaKmdpdGh1",
+            "Yi5jb20vZ29sYW5nL3Byb3RvYnVmL3B0eXBlcy93cmFwcGVyc6ABAfgBAaIC",
+            "A0dQQqoCHkdvb2dsZS5Qcm90b2J1Zi5XZWxsS25vd25UeXBlc2IGcHJvdG8z"));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {

docs/swift/DesignDoc.md

@@ -0,0 +1,674 @@
+# Protocol Buffers in Swift
+
+## Objective
+
+This document describes the user-facing API and internal implementation of
+proto2 and proto3 messages in Apple’s Swift programming language.
+
+One of the key goals of protobufs is to provide idiomatic APIs for each
+language. In that vein, **interoperability with Objective-C is a non-goal of
+this proposal.** Protobuf users who need to pass messages between Objective-C
+and Swift code in the same application should use the existing Objective-C proto
+library. The goal of the effort described here is to provide an API for protobuf
+messages that uses features specific to Swift—optional types, algebraic
+enumerated types, value types, and so forth—in a natural way that will delight,
+rather than surprise, users of the language.
+
+## Naming
+
+*   By convention, both typical protobuf message names and Swift structs/classes
+    are `UpperCamelCase`, so for most messages, the name of a message can be the
+    same as the name of its generated type. (However, see the discussion below
+    about prefixes under [Packages](#packages).)
+
+*   Enum cases in protobufs typically are `UPPERCASE_WITH_UNDERSCORES`, whereas
+    in Swift they are `lowerCamelCase` (as of the Swift 3 API design
+    guidelines). We will transform the names to match Swift convention, using
+    a whitelist similar to the Objective-C compiler plugin to handle commonly
+    used acronyms.
+
+*   Typical fields in proto messages are `lowercase_with_underscores`, while in
+    Swift they are `lowerCamelCase`. We will transform the names to match
+    Swift convention by removing the underscores and uppercasing the subsequent
+    letter.
+
+## Swift reserved words
+
+Swift has a large set of reserved words—some always reserved and some
+contextually reserved (that is, they can be used as identifiers in contexts
+where they would not be confused). As of Swift 2.2, the set of always-reserved
+words is:
+
+```
+_, #available, #column, #else, #elseif, #endif, #file, #function, #if, #line,
+#selector, as, associatedtype, break, case, catch, class, continue, default,
+defer, deinit, do, dynamicType, else, enum, extension, fallthrough, false, for,
+func, guard, if, import, in, init, inout, internal, is, let, nil, operator,
+private, protocol, public, repeat, rethrows, return, self, Self, static,
+struct, subscript, super, switch, throw, throws, true, try, typealias, var,
+where, while
+```
+
+The set of contextually reserved words is:
+
+```
+associativity, convenience, dynamic, didSet, final, get, infix, indirect,
+lazy, left, mutating, none, nonmutating, optional, override, postfix,
+precedence, prefix, Protocol, required, right, set, Type, unowned, weak,
+willSet
+```
+
+It is possible to use any reserved word as an identifier by escaping it with
+backticks (for example, ``let `class` = 5``). Other name-mangling schemes would
+require us to transform the names themselves (for example, by appending an
+underscore), which requires us to then ensure that the new name does not collide
+with something else in the same namespace.
+
+While the backtick feature may not be widely known by all Swift developers, a
+small amount of user education can address this and it seems like the best
+approach. We can unconditionally surround all property names with backticks to
+simplify generation.
+
+Some remapping will still be required, though, to avoid collisions between
+generated properties and the names of methods and properties defined in the base
+protocol/implementation of messages.
+
+# Features of Protocol Buffers
+
+This section describes how the features of the protocol buffer syntaxes (proto2
+and proto3) map to features in Swift—what the code generated from a proto will
+look like, and how it will be implemented in the underlying library.
+
+## Packages
+
+Modules are the main form of namespacing in Swift, but they are not declared
+using syntactic constructs like namespaces in C++ or packages in Java. Instead,
+they are tied to build targets in Xcode (or, in the future with open-source
+Swift, declarations in a Swift Package Manager manifest). They also do not
+easily support nesting submodules (Clang module maps support this, but pure
+Swift does not yet provide a way to define submodules).
+
+We will generate types with fully-qualified underscore-delimited names. For
+example, a message `Baz` in package `foo.bar` would generate a struct named
+`Foo_Bar_Baz`. For each fully-qualified proto message, there will be exactly one
+unique type symbol emitted in the generated binary.
+
+Users are likely to balk at the ugliness of underscore-delimited names for every
+generated type. To improve upon this situation, we will add a new string file
+level option, `swift_package_typealias`, that can be added to `.proto` files.
+When present, this will cause `typealias`es to be added to the generated Swift
+messages that replace the package name prefix with the provided string. For
+example, the following `.proto` file:
+
+```protobuf
+option swift_package_typealias = "FBP";
+package foo.bar;
+
+message Baz {
+  // Message fields
+}
+```
+
+would generate the following Swift source:
+
+```swift
+public struct Foo_Bar_Baz {
+  // Message fields and other methods
+}
+
+typealias FBPBaz = Foo_Bar_Baz
+```
+
+It should be noted that this type alias is recorded in the generated
+`.swiftmodule` so that code importing the module can refer to it, but it does
+not cause a new symbol to be generated in the compiled binary (i.e., we do not
+risk compiled size bloat by adding `typealias`es for every type).
+
+Other strategies to handle packages that were considered and rejected can be
+found in [Appendix A](#appendix-a-rejected-strategies-to-handle-packages).
+
+## Messages
+
+Proto messages are natural value types and we will generate messages as structs
+instead of classes. Users will benefit from Swift’s built-in behavior with
+regard to mutability. We will define a `ProtoMessage` protocol that defines the
+common methods and properties for all messages (such as serialization) and also
+lets users treat messages polymorphically. Any shared method implementations
+that do not differ between individual messages can be implemented in a protocol
+extension.
+
+The backing storage itself for fields of a message will be managed by a
+`ProtoFieldStorage` type that uses an internal dictionary keyed by field number,
+and whose values are the value of the field with that number (up-cast to Swift’s
+`Any` type). This class will provide type-safe getters and setters so that
+generated messages can manipulate this storage, and core serialization logic
+will live here as well. Furthermore, factoring the storage out into a separate
+type, rather than inlining the fields as stored properties in the message
+itself, lets us implement copy-on-write efficiently to support passing around
+large messages. (Furthermore, because the messages themselves are value types,
+inlining fields is not possible if the fields are submessages of the same type,
+or a type that eventually includes a submessage of the same type.)
+
+### Required fields (proto2 only)
+
+Required fields in proto2 messages seem like they could be naturally represented
+by non-optional properties in Swift, but this presents some problems/concerns.
+
+Serialization APIs permit partial serialization, which allows required fields to
+remain unset. Furthermore, other language APIs still provide `has*` and `clear*`
+methods for required fields, and knowing whether a property has a value when the
+message is in memory is still useful.
+
+For example, an e-mail draft message may have the “to” address required on the
+wire, but when the user constructs it in memory, it doesn’t make sense to force
+a value until they provide one. We only want to force a value to be present when
+the message is serialized to the wire. Using non-optional properties prevents
+this use case, and makes client usage awkward because the user would be forced
+to select a sentinel or placeholder value for any required fields at the time
+the message was created.
+
+### Default values
+
+In proto2, fields can have a default value specified that may be a value other
+than the default value for its corresponding language type (for example, a
+default value of 5 instead of 0 for an integer). When reading a field that is
+not explicitly set, the user expects to get that value. This makes Swift
+optionals (i.e., `Foo?`) unsuitable for fields in general. Unfortunately, we
+cannot implement our own “enhanced optional” type without severely complicating
+usage (Swift’s use of type inference and its lack of implicit conversions would
+require manual unwrapping of every property value).
+
+Instead, we can use **implicitly unwrapped optionals.** For example, a property
+generated for a field of type `int32` would have Swift type `Int32!`. These
+properties would behave with the following characteristics, which mirror the
+nil-resettable properties used elsewhere in Apple’s SDKs (for example,
+`UIView.tintColor`):
+
+*   Assigning a non-nil value to a property sets the field to that value.
+*   Assigning nil to a property clears the field (its internal representation is
+    nilled out).
+*   Reading the value of a property returns its value if it is set, or returns
+    its default value if it is not set. Reading a property never returns nil.
+
+The final point in the list above implies that the optional cannot be checked to
+determine if the field is set to a value other than its default: it will never
+be nil. Instead, we must provide `has*` methods for each field to allow the user
+to check this. These methods will be public in proto2. In proto3, these methods
+will be private (if generated at all), since the user can test the returned
+value against the zero value for that type.
+
+### Autocreation of nested messages
+
+For convenience, dotting into an unset field representing a nested message will
+return an instance of that message with default values. As in the Objective-C
+implementation, this does not actually cause the field to be set until the
+returned message is mutated. Fortunately, thanks to the way mutability of value
+types is implemented in Swift, the language automatically handles the
+reassignment-on-mutation for us. A static singleton instance containing default
+values can be associated with each message that can be returned when reading, so
+copies are only made by the Swift runtime when mutation occurs. For example,
+given the following proto:
+
+```protobuf
+message Node {
+  Node child = 1;
+  string value = 2 [default = "foo"];
+}
+```
+
+The following Swift code would act as commented, where setting deeply nested
+properties causes the copies and mutations to occur as the assignment statement
+is unwound:
+
+```swift
+var node = Node()
+
+let s = node.child.child.value
+// 1. node.child returns the "default Node".
+// 2. Reading .child on the result of (1) returns the same default Node.
+// 3. Reading .value on the result of (2) returns the default value "foo".
+
+node.child.child.value = "bar"
+// 4. Setting .value on the default Node causes a copy to be made and sets
+//    the property on that copy. Subsequently, the language updates the
+//    value of "node.child.child" to point to that copy.
+// 5. Updating "node.child.child" in (4) requires another copy, because
+//    "node.child" was also the instance of the default node. The copy is
+//    assigned back to "node.child".
+// 6. Setting "node.child" in (5) is a simple value reassignment, since
+//    "node" is a mutable var.
+```
+
+In other words, the generated messages do not internally have to manage parental
+relationships to backfill the appropriate properties on mutation. Swift provides
+this for free.
+
+## Scalar value fields
+
+Proto scalar value fields will map to Swift types in the following way:
+
+.proto Type | Swift Type
+----------- | -------------------
+`double`    | `Double`
+`float`     | `Float`
+`int32`     | `Int32`
+`int64`     | `Int64`
+`uint32`    | `UInt32`
+`uint64`    | `UInt64`
+`sint32`    | `Int32`
+`sint64`    | `Int64`
+`fixed32`   | `UInt32`
+`fixed64`   | `UInt64`
+`sfixed32`  | `Int32`
+`sfixed64`  | `Int64`
+`bool`      | `Bool`
+`string`    | `String`
+`bytes`     | `Foundation.NSData`
+
+The proto spec defines a number of integral types that map to the same Swift
+type; for example, `intXX`, `sintXX`, and `sfixedXX` are all signed integers,
+and `uintXX` and `fixedXX` are both unsigned integers. No other language
+implementation distinguishes these further, so we do not do so either. The
+rationale is that the various types only serve to distinguish how the value is
+**encoded on the wire**; once loaded in memory, the user is not concerned about
+these variations.
+
+Swift’s lack of implicit conversions among types will make it slightly annoying
+to use these types in a context expecting an `Int`, or vice-versa, but since
+this is a data-interchange format with explicitly-sized fields, we should not
+hide that information from the user. Users will have to explicitly write
+`Int(message.myField)`, for example.
+
+## Embedded message fields
+
+Embedded message fields can be represented using an optional variable of the
+generated message type. Thus, the message
+
+```protobuf
+message Foo {
+  Bar bar = 1;
+}
+```
+
+would be represented in Swift as
+
+```swift
+public struct Foo: ProtoMessage {
+  public var bar: Bar! {
+    get { ... }
+    set { ... }
+  }
+}
+```
+
+If the user explicitly sets `bar` to nil, or if it was never set when read from
+the wire, retrieving the value of `bar` would return a default, statically
+allocated instance of `Bar` containing default values for its fields. This
+achieves the desired behavior for default values in the same way that scalar
+fields are designed, and also allows users to deep-drill into complex object
+graphs to get or set fields without checking for nil at each step.
+
+## Enum fields
+
+The design and implementation of enum fields will differ somewhat drastically
+depending on whether the message being generated is a proto2 or proto3 message.
+
+### proto2 enums
+
+For proto2, we do not need to be concerned about unknown enum values, so we can
+use the simple raw-value enum syntax provided by Swift. So the following enum in
+proto2:
+
+```protobuf
+enum ContentType {
+  TEXT = 0;
+  IMAGE = 1;
+}
+```
+
+would become this Swift enum:
+
+```swift
+public enum ContentType: Int32, NilLiteralConvertible {
+  case text = 0
+  case image = 1
+
+  public init(nilLiteral: ()) {
+    self = .text
+  }
+}
+```
+
+See below for the discussion about `NilLiteralConvertible`.
+
+### proto3 enums
+
+For proto3, we need to be able to preserve unknown enum values that may come
+across the wire so that they can be written back if unmodified. We can
+accomplish this in Swift by using a case with an associated value for unknowns.
+So the following enum in proto3:
+
+```protobuf
+enum ContentType {
+  TEXT = 0;
+  IMAGE = 1;
+}
+```
+
+would become this Swift enum:
+
+```swift
+public enum ContentType: RawRepresentable, NilLiteralConvertible {
+  case text
+  case image
+  case UNKNOWN_VALUE(Int32)
+
+  public typealias RawValue = Int32
+
+  public init(nilLiteral: ()) {
+    self = .text
+  }
+
+  public init(rawValue: RawValue) {
+    switch rawValue {
+      case 0: self = .text
+      case 1: self = .image
+      default: self = .UNKNOWN_VALUE(rawValue)
+  }
+
+  public var rawValue: RawValue {
+    switch self {
+      case .text: return 0
+      case .image: return 1
+      case .UNKNOWN_VALUE(let value): return value
+    }
+  }
+}
+```
+
+Note that the use of a parameterized case prevents us from inheriting from the
+raw `Int32` type; Swift does not allow an enum with a raw type to have cases
+with arguments. Instead, we must implement the raw value initializer and
+computed property manually. The `UNKNOWN_VALUE` case is explicitly chosen to be
+"ugly" so that it stands out and does not conflict with other possible case
+names.
+
+Using this approach, proto3 consumers must always have a default case or handle
+the `.UNKNOWN_VALUE` case to satisfy case exhaustion in a switch statement; the
+Swift compiler considers it an error if switch statements are not exhaustive.
+
+### NilLiteralConvertible conformance
+
+This is required to clean up the usage of enum-typed properties in switch
+statements. Unlike other field types, enum properties cannot be
+implicitly-unwrapped optionals without requiring that uses in switch statements
+be explicitly unwrapped. For example, if we consider a message with the enum
+above, this usage will fail to compile:
+
+```swift
+// Without NilLiteralConvertible conformance on ContentType
+public struct SomeMessage: ProtoMessage {
+  public var contentType: ContentType! { ... }
+}
+
+// ERROR: no case named text or image
+switch someMessage.contentType {
+  case .text: { ... }
+  case .image: { ... }
+}
+```
+
+Even though our implementation guarantees that `contentType` will never be nil,
+if it is an optional type, its cases would be `some` and `none`, not the cases
+of the underlying enum type. In order to use it in this context, the user must
+write `someMessage.contentType!` in their switch statement.
+
+Making the enum itself `NilLiteralConvertible` permits us to make the property
+non-optional, so the user can still set it to nil to clear it (i.e., reset it to
+its default value), while eliminating the need to explicitly unwrap it in a
+switch statement.
+
+```swift
+// With NilLiteralConvertible conformance on ContentType
+public struct SomeMessage: ProtoMessage {
+  // Note that the property type is no longer optional
+  public var contentType: ContentType { ... }
+}
+
+// OK: Compiles and runs as expected
+switch someMessage.contentType {
+  case .text: { ... }
+  case .image: { ... }
+}
+
+// The enum can be reset to its default value this way
+someMessage.contentType = nil
+```
+
+One minor oddity with this approach is that nil will be auto-converted to the
+default value of the enum in any context, not just field assignment. In other
+words, this is valid:
+
+```swift
+func foo(contentType: ContentType) { ... }
+foo(nil) // Inside foo, contentType == .text
+```
+
+That being said, the advantage of being able to simultaneously support
+nil-resettability and switch-without-unwrapping outweighs this side effect,
+especially if appropriately documented. It is our hope that a new form of
+resettable properties will be added to Swift that eliminates this inconsistency.
+Some community members have already drafted or sent proposals for review that
+would benefit our designs:
+
+*   [SE-0030: Property Behaviors]
+    (https://github.com/apple/swift-evolution/blob/master/proposals/0030-property-behavior-decls.md)
+*   [Drafted: Resettable Properties]
+    (https://github.com/patters/swift-evolution/blob/master/proposals/0000-resettable-properties.md)
+
+### Enum aliases
+
+The `allow_alias` option in protobuf slightly complicates the use of Swift enums
+to represent that type, because raw values of cases in an enum must be unique.
+Swift lets us define static variables in an enum that alias actual cases. For
+example, the following protobuf enum:
+
+```protobuf
+enum Foo {
+  option allow_alias = true;
+  BAR = 0;
+  BAZ = 0;
+}
+```
+
+will be represented in Swift as:
+
+```swift
+public enum Foo: Int32, NilLiteralConvertible {
+  case bar = 0
+  static public let baz = bar
+
+  // ... etc.
+}
+
+// Can still use .baz shorthand to reference the alias in contexts
+// where the type is inferred
+```
+
+That is, we use the first name as the actual case and use static variables for
+the other aliases. One drawback to this approach is that the static aliases
+cannot be used as cases in a switch statement (the compiler emits the error
+*“Enum case ‘baz’ not found in type ‘Foo’”*). However, in our own code bases,
+there are only a few places where enum aliases are not mere renamings of an
+older value, but they also don’t appear to be the type of value that one would
+expect to switch on (for example, a group of named constants representing
+metrics rather than a set of options), so this restriction is not significant.
+
+This strategy also implies that changing the name of an enum and adding the old
+name as an alias below the new name will be a breaking change in the generated
+Swift code.
+
+## Oneof types
+
+The `oneof` feature represents a “variant/union” data type that maps nicely to
+Swift enums with associated values (algebraic types). These fields can also be
+accessed independently though, and, specifically in the case of proto2, it’s
+reasonable to expect access to default values when accessing a field that is not
+explicitly set.
+
+Taking all this into account, we can represent a `oneof` in Swift with two sets
+of constructs:
+
+*   Properties in the message that correspond to the `oneof` fields.
+*   A nested enum named after the `oneof` and which provides the corresponding
+    field values as case arguments.
+
+This approach fulfills the needs of proto consumers by providing a
+Swift-idiomatic way of simultaneously checking which field is set and accessing
+its value, providing individual properties to access the default values
+(important for proto2), and safely allows a field to be moved into a `oneof`
+without breaking clients.
+
+Consider the following proto:
+
+```protobuf
+message MyMessage {
+  oneof record {
+    string name = 1 [default = "unnamed"];
+    int32 id_number = 2 [default = 0];
+  }
+}
+```
+
+In Swift, we would generate an enum, a property for that enum, and properties
+for the fields themselves:
+
+```swift
+public struct MyMessage: ProtoMessage {
+  public enum Record: NilLiteralConvertible {
+    case name(String)
+    case idNumber(Int32)
+    case NOT_SET
+
+    public init(nilLiteral: ()) { self = .NOT_SET }
+  }
+
+  // This is the "Swifty" way of accessing the value
+  public var record: Record { ... }
+
+  // Direct access to the underlying fields
+  public var name: String! { ... }
+  public var idNumber: Int32! { ... }
+}
+```
+
+This makes both usage patterns possible:
+
+```swift
+// Usage 1: Case-based dispatch
+switch message.record {
+  case .name(let name):
+    // Do something with name if it was explicitly set
+  case .idNumber(let id):
+    // Do something with id_number if it was explicitly set
+  case .NOT_SET:
+    // Do something if it’s not set
+}
+
+// Usage 2: Direct access for default value fallback
+// Sets the label text to the name if it was explicitly set, or to
+// "unnamed" (the default value for the field) if id_number was set
+// instead
+let myLabel = UILabel()
+myLabel.text = message.name
+```
+
+As with proto enums, the generated `oneof` enum conforms to
+`NilLiteralConvertible` to avoid switch statement issues. Setting the property
+to nil will clear it (i.e., reset it to `NOT_SET`).
+
+## Unknown Fields (proto2 only)
+
+To be written.
+
+## Extensions (proto2 only)
+
+To be written.
+
+## Reflection and Descriptors
+
+We will not include reflection or descriptors in the first version of the Swift
+library. The use cases for reflection on mobile are not as strong and the static
+data to represent the descriptors would add bloat when we wish to keep the code
+size small.
+
+In the future, we will investigate whether they can be included as extensions
+which might be able to be excluded from a build and/or automatically dead
+stripped by the compiler if they are not used.
+
+## Appendix A: Rejected strategies to handle packages
+
+### Each package is its own Swift module
+
+Each proto package could be declared as its own Swift module, replacing dots
+with underscores (e.g., package `foo.bar` becomes module `Foo_Bar`). Then, users
+would simply import modules containing whatever proto modules they want to use
+and refer to the generated types by their short names.
+
+**This solution is simply not possible, however.** Swift modules cannot
+circularly reference each other, but there is no restriction against proto
+packages doing so. Circular imports are forbidden (e.g., `foo.proto` importing
+`bar.proto` importing `foo.proto`), but nothing prevents package `foo` from
+using a type in package `bar` which uses a different type in package `foo`, as
+long as there is no import cycle. If these packages were generated as Swift
+modules, then `Foo` would contain an `import Bar` statement and `Bar` would
+contain an `import Foo` statement, and there is no way to compile this.
+
+### Ad hoc namespacing with structs
+
+We can “fake” namespaces in Swift by declaring empty structs with private
+initializers. Since modules are constructed based on compiler arguments, not by
+syntactic constructs, and because there is no pure Swift way to define
+submodules (even though Clang module maps support this), there is no
+source-drive way to group generated code into namespaces aside from this
+approach.
+
+Types can be added to those intermediate package structs using Swift extensions.
+For example, a message `Baz` in package `foo.bar` could be represented in Swift
+as follows:
+
+```swift
+public struct Foo {
+  private init() {}
+}
+
+public extension Foo {
+  public struct Bar {
+    private init() {}
+  }
+}
+
+public extension Foo.Bar {
+  public struct Baz {
+    // Message fields and other methods
+  }
+}
+
+let baz = Foo.Bar.Baz()
+```
+
+Each of these constructs would actually be defined in a separate file; Swift
+lets us keep them separate and add multiple structs to a single “namespace”
+through extensions.
+
+Unfortunately, these intermediate structs generate symbols of their own
+(metatype information in the data segment). This becomes problematic if multiple
+build targets contain Swift sources generated from different messages in the
+same package. At link time, these symbols would collide, resulting in multiple
+definition errors.
+
+This approach also has the disadvantage that there is no automatic “short” way
+to refer to the generated messages at the deepest nesting levels; since this use
+of structs is a hack around the lack of namespaces, there is no equivalent to
+import (Java) or using (C++) to simplify this. Users would have to declare type
+aliases to make this cleaner, or we would have to generate them for users.

docs/third_party.md

@@ -0,0 +1,147 @@
+# Third-Party Add-ons for Protocol Buffers
+
+This page lists code related to Protocol Buffers which is developed and maintained by third parties.  You may find this code useful, but note that **these projects are not affiliated with or endorsed by Google (unless explicitly marked)**; try them at your own risk.  Also note that many projects here are in the early stages of development and not production-ready.
+
+If you have a project that should be listed here, please [send us a pull request](https://github.com/google/protobuf/pulls) to update this page.
+
+## Programming Languages
+
+These are projects we know about implementing Protocol Buffers for other programming languages:
+* Action Script: http://code.google.com/p/protobuf-actionscript3/
+* Action Script: https://code.google.com/p/protoc-gen-as3/
+* Action Script: https://github.com/matrix3d/JProtoc
+* C: https://github.com/protobuf-c/protobuf-c
+* C: http://koti.kapsi.fi/jpa/nanopb/
+* C: https://github.com/cloudwu/pbc/
+* C: https://github.com/haberman/upb/wiki
+* C: https://github.com/squidfunk/protobluff
+* C++: https://github.com/google/protobuf (Google-official implementation)
+* C/C++: http://spbc.sf.net/
+* C#: http://code.google.com/p/protobuf-csharp-port
+* C#: http://code.google.com/p/protosharp/
+* C#: https://silentorbit.com/protobuf/
+* C#/.NET/WCF/VB: http://code.google.com/p/protobuf-net/
+* Clojure: http://github.com/ninjudd/clojure-protobuf
+* Common Lisp: http://www.prism.gatech.edu/~ndantam3/docs/s-protobuf/
+* Common Lisp: http://github.com/brown/protobuf
+* D: https://github.com/msoucy/dproto
+* D: http://256.makerslocal.org/wiki/index.php/ProtocolBuffer
+* D: https://github.com/opticron/ProtocolBuffer
+* Dart: https://github.com/dart-lang/dart-protobuf (runtime) https://github.com/dart-lang/dart-protoc-plugin (code generator)
+* Delphi: http://sourceforge.net/projects/protobuf-delphi/
+* Delphi: http://fundementals.sourceforge.net/dl.html
+* Elixir: https://github.com/jeremyong/exprotoc
+* Erlang: http://github.com/ngerakines/erlang_protobuffs/tree/master
+* Erlang: http://piqi.org/
+* Erlang: https://code.google.com/p/protoc-gen-erl/
+* Erlang: https://github.com/basho/erlang_protobuffs
+* Go: https://github.com/golang/protobuf (Google-official implementation)
+* Go: http://code.google.com/p/goprotobuf/
+* Go: https://github.com/akunspy/gopbuf
+* Haskell: http://hackage.haskell.org/package/hprotoc
+* Haxe: https://github.com/Atry/protoc-gen-haxe
+* Java: https://github.com/google/protobuf (Google-official implementation)
+* Java/Android: https://github.com/square/wire
+* Java ME: http://code.google.com/p/protobuf-javame/
+* Java ME: http://swingme.sourceforge.net/encode.shtml
+* Java ME: http://github.com/ponderingpanda/protobuf-j2me
+* Java ME: http://code.google.com/p/protobuf-j2me/
+* Javascript: http://code.google.com/p/protobuf-js/
+* Javascript: http://github.com/sirikata/protojs
+* Javascript: https://github.com/dcodeIO/ProtoBuf.js
+* Javascript: http://code.google.com/p/protobuf-for-node/
+* Javascript: http://code.google.com/p/protostuff/
+* Julia: https://github.com/tanmaykm/ProtoBuf.jl
+* Lua: http://code.google.com/p/protoc-gen-lua/
+* Lua: http://github.com/indygreg/lua-protobuf
+* Lua: https://github.com/Neopallium/lua-pb
+* Matlab: http://code.google.com/p/protobuf-matlab/
+* Mercury: http://code.google.com/p/protobuf-mercury/
+* Objective C: http://code.google.com/p/protobuf-objc/
+* Objective C: https://github.com/alexeyxo/protobuf-objc
+* OCaml: http://piqi.org/
+* Perl: http://groups.google.com/group/protobuf-perl
+* Perl: http://search.cpan.org/perldoc?Google::ProtocolBuffers
+* Perl/XS: http://code.google.com/p/protobuf-perlxs/
+* PHP: http://code.google.com/p/pb4php/
+* PHP: https://github.com/allegro/php-protobuf/
+* PHP: https://github.com/chobie/php-protocolbuffers
+* PHP: http://drslump.github.com/Protobuf-PHP
+* Prolog: http://www.swi-prolog.org/pldoc/package/protobufs.html
+* Python: https://github.com/google/protobuf (Google-official implementation)
+* Python: http://eigenein.github.com/protobuf/
+* R: http://cran.r-project.org/package=RProtoBuf
+* Ruby: http://code.google.com/p/ruby-protobuf/
+* Ruby: http://github.com/mozy/ruby-protocol-buffers
+* Ruby: https://github.com/bmizerany/beefcake/tree/master/lib/beefcake
+* Ruby: https://github.com/localshred/protobuf
+* Rust: https://github.com/stepancheg/rust-protobuf/
+* Scala: http://github.com/jeffplaisance/scala-protobuf
+* Scala: http://code.google.com/p/protobuf-scala
+* Scala: https://github.com/SandroGrzicic/ScalaBuff
+* Scala: http://trueaccord.github.io/ScalaPB/
+* Swift: https://github.com/alexeyxo/protobuf-swift
+* Vala: https://launchpad.net/protobuf-vala
+* Visual Basic: http://code.google.com/p/protobuf-net/
+
+## RPC Implementations
+
+GRPC (http://www.grpc.io/) is Google's RPC implementation for Protocol Buffers. There are other third-party RPC implementations as well.  Some of these actually work with Protocol Buffers service definitions (defined using the `service` keyword in `.proto` files) while others just use Protocol Buffers message objects.
+
+* https://github.com/grpc/grpc (C++, Node.js, Python, Ruby, Objective-C, PHP, C#, Google-official implementation)
+* http://zeroc.com/ice.html (Multiple languages)
+* http://code.google.com/p/protobuf-net/ (C#/.NET/WCF/VB)
+* https://launchpad.net/txprotobuf/ (Python)
+* https://github.com/modeswitch/protobuf-rpc (Python)
+* http://code.google.com/p/protobuf-socket-rpc/ (Java, Python)
+* http://code.google.com/p/proto-streamer/ (Java)
+* http://code.google.com/p/server1/ (C++)
+* http://deltavsoft.com/RcfUserGuide/Protobufs (C++)
+* http://code.google.com/p/protobuf-mina-rpc/ (Python client, Java server)
+* http://code.google.com/p/casocklib/ (C++)
+* http://code.google.com/p/cxf-protobuf/ (Java)
+* http://code.google.com/p/protobuf-remote/ (C++/C#)
+* http://code.google.com/p/protobuf-rpc-pro/ (Java)
+* https://code.google.com/p/protorpc/ (Go/C++)
+* https://code.google.com/p/eneter-protobuf-serializer/ (Java/.NET)
+* http://www.deltavsoft.com/RCFProto.html (C++/Java/Python/C#)
+* https://github.com/robbinfan/claire-protorpc (C++)
+* https://github.com/BaiduPS/sofa-pbrpc (C++)
+* https://github.com/ebencheung/arab (C++)
+* http://code.google.com/p/protobuf-csharp-rpc/ (C#)
+* https://github.com/thesamet/rpcz (C++/Python, based on ZeroMQ)
+* https://github.com/w359405949/libmaid (C++, Python)
+* https://github.com/madwyn/libpbrpc (C++)
+
+## Other Utilities
+
+There are miscellaneous other things you may find useful as a Protocol Buffers developer.
+
+* [NetBeans IDE plugin](http://code.google.com/p/protobuf-netbeans-plugin/)
+* [Wireshark/Ethereal packet sniffer plugin](http://code.google.com/p/protobuf-wireshark/)
+* [Alternate encodings (JSON, XML, HTML) for Java protobufs](http://code.google.com/p/protobuf-java-format/)
+* [Another JSON encoder/decoder for Java](https://github.com/sijuv/protobuf-codec)
+* [Editor for serialized protobufs](http://code.google.com/p/protobufeditor/)
+* [Intellij IDEA plugin](http://github.com/nnmatveev/idea-plugin-protobuf)
+* [TextMate syntax highlighting](http://github.com/michaeledgar/protobuf-tmbundle)
+* [Oracle PL SQL plugin](http://code.google.com/p/protocol-buffer-plsql/)
+* [Eclipse editor for protobuf (from Google)](http://code.google.com/p/protobuf-dt/)
+* [C++ Builder compatible protobuf](https://github.com/saadware/protobuf-cppbuilder)
+* Maven Protocol Compiler Plugin
+    * https://github.com/sergei-ivanov/maven-protoc-plugin/
+    * http://igor-petruk.github.com/protobuf-maven-plugin/
+    * http://code.google.com/p/maven-protoc-plugin/
+    * https://github.com/os72/protoc-jar-maven-plugin
+* [Documentation generator plugin (Markdown/HTML/DocBook/...)](https://github.com/estan/protoc-gen-doc)
+* [DocBook generator for .proto files](http://code.google.com/p/protoc-gen-docbook/)
+* [Protobuf for nginx module](https://github.com/dbcode/protobuf-nginx/)
+* [RSpec matchers and Cucumber step defs for testing Protocol Buffers](https://github.com/connamara/protobuf_spec)
+* [Sbt plugin for Protocol Buffers](https://github.com/Atry/sbt-cppp)
+* [Gradle Protobuf Plugin](https://github.com/aantono/gradle-plugin-protobuf)
+* [Multi-platform executable JAR and Java API for protoc](https://github.com/os72/protoc-jar)
+* [Python scripts to convert between Protocol Buffers and JSON](https://github.com/NextTuesday/py-pb-converters)
+* [Visual Studio Language Service support for Protocol Buffers](http://visualstudiogallery.msdn.microsoft.com/4bc0f38c-b058-4e05-ae38-155e053c19c5)
+* [C++ library for serialization/de-serialization between Protocol Buffers and JSON.](https://github.com/yinqiwen/pbjson)
+* [ProtoBuf with Java EE7 Expression Language 3.0; pure Java ProtoBuf Parser and Builder.](https://github.com/protobufel/protobuf-el)
+* [Notepad++ Syntax Highlighting for .proto files](https://github.com/chai2010/notepadplus-protobuf)
+* [Linter for .proto files](https://github.com/ckaznocha/protoc-gen-lint)

generate_descriptor_proto.sh

@@ -10,8 +10,6 @@
 #   to make when building protoc.  This is particularly useful for passing
 #   -j4 to run 4 jobs simultaneously.
 
-set -e
-
 if test ! -e src/google/protobuf/stubs/common.h; then
   cat >&2 << __EOF__
 Could not find source code.  Make sure you are running this script from the
@@ -52,9 +50,14 @@ do
   echo "Round $PROCESS_ROUND"
   CORE_PROTO_IS_CORRECT=1
 
-  make $@ protoc &&
-    ./protoc --cpp_out=dllexport_decl=LIBPROTOBUF_EXPORT:$TMP ${RUNTIME_PROTO_FILES[@]} && \
-    ./protoc --cpp_out=dllexport_decl=LIBPROTOC_EXPORT:$TMP google/protobuf/compiler/plugin.proto
+  make $@ protoc
+  if test $? -ne 0; then
+    echo "Failed to build protoc."
+    exit 1
+  fi
+
+  ./protoc --cpp_out=dllexport_decl=LIBPROTOBUF_EXPORT:$TMP ${RUNTIME_PROTO_FILES[@]} && \
+  ./protoc --cpp_out=dllexport_decl=LIBPROTOC_EXPORT:$TMP google/protobuf/compiler/plugin.proto
 
   for PROTO_FILE in ${RUNTIME_PROTO_FILES[@]}; do
     BASE_NAME=${PROTO_FILE%.*}
@@ -92,9 +95,9 @@ do
 done
 cd ..
 
-if test -x objectivec/generate_descriptors_proto.sh; then
+if test -x objectivec/generate_well_known_types.sh; then
   echo "Generating messages for objc."
-  objectivec/generate_descriptors_proto.sh $@
+  objectivec/generate_well_known_types.sh $@
 fi
 
 if test -x csharp/generate_protos.sh; then

java/core/src/main/java/com/google/protobuf/AbstractMessage.java

@@ -50,17 +50,23 @@ import java.util.Map;
  *
  * @author kenton@google.com Kenton Varda
  */
-public abstract class AbstractMessage extends AbstractMessageLite
-                                      implements Message {
+public abstract class AbstractMessage
+    // TODO(dweis): Update GeneratedMessage to parameterize with MessageType and BuilderType.
+    extends AbstractMessageLite
+    implements Message {
+  
+  @Override
   public boolean isInitialized() {
     return MessageReflection.isInitialized(this);
   }
 
 
+  @Override
   public List<String> findInitializationErrors() {
     return MessageReflection.findMissingFields(this);
   }
 
+  @Override
   public String getInitializationErrorString() {
     return MessageReflection.delimitWithCommas(findInitializationErrors());
   }
@@ -83,12 +89,14 @@ public abstract class AbstractMessage extends AbstractMessageLite
     return TextFormat.printToString(this);
   }
 
+  @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
     MessageReflection.writeMessageTo(this, getAllFields(), output, false);
   }
 
   protected int memoizedSize = -1;
 
+  @Override
   public int getSerializedSize() {
     int size = memoizedSize;
     if (size != -1) {
@@ -288,8 +296,8 @@ public abstract class AbstractMessage extends AbstractMessageLite
    * other methods.
    */
   @SuppressWarnings("unchecked")
-  public static abstract class Builder<BuilderType extends Builder>
-      extends AbstractMessageLite.Builder<BuilderType>
+  public static abstract class Builder<BuilderType extends Builder<BuilderType>>
+      extends AbstractMessageLite.Builder
       implements Message.Builder {
     // The compiler produces an error if this is not declared explicitly.
     @Override
@@ -314,6 +322,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
       throw new UnsupportedOperationException("clearOneof() is not implemented.");
     }
 
+    @Override
     public BuilderType clear() {
       for (final Map.Entry<FieldDescriptor, Object> entry :
            getAllFields().entrySet()) {
@@ -322,14 +331,22 @@ public abstract class AbstractMessage extends AbstractMessageLite
       return (BuilderType) this;
     }
 
+    @Override
     public List<String> findInitializationErrors() {
       return MessageReflection.findMissingFields(this);
     }
 
+    @Override
     public String getInitializationErrorString() {
       return MessageReflection.delimitWithCommas(findInitializationErrors());
     }
+    
+    @Override
+    protected BuilderType internalMergeFrom(AbstractMessageLite other) {
+      return mergeFrom((Message) other);
+    }
 
+    @Override
     public BuilderType mergeFrom(final Message other) {
       if (other.getDescriptorForType() != getDescriptorForType()) {
         throw new IllegalArgumentException(
@@ -407,6 +424,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
       return (BuilderType) this;
     }
 
+    @Override
     public BuilderType mergeUnknownFields(final UnknownFieldSet unknownFields) {
       setUnknownFields(
         UnknownFieldSet.newBuilder(getUnknownFields())
@@ -415,17 +433,19 @@ public abstract class AbstractMessage extends AbstractMessageLite
       return (BuilderType) this;
     }
 
+    @Override
     public Message.Builder getFieldBuilder(final FieldDescriptor field) {
       throw new UnsupportedOperationException(
           "getFieldBuilder() called on an unsupported message type.");
     }
 
-    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field,
-        int index) {
+    @Override
+    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field, int index) {
       throw new UnsupportedOperationException(
           "getRepeatedFieldBuilder() called on an unsupported message type.");
     }
 
+    @Override
     public String toString() {
       return TextFormat.printToString(this);
     }
@@ -462,7 +482,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
     @Override
     public BuilderType mergeFrom(final ByteString data)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data);
+      return (BuilderType) super.mergeFrom(data);
     }
 
     @Override
@@ -470,20 +490,20 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final ByteString data,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, extensionRegistry);
+      return (BuilderType) super.mergeFrom(data, extensionRegistry);
     }
 
     @Override
     public BuilderType mergeFrom(final byte[] data)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data);
+      return (BuilderType) super.mergeFrom(data);
     }
 
     @Override
     public BuilderType mergeFrom(
         final byte[] data, final int off, final int len)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, off, len);
+      return (BuilderType) super.mergeFrom(data, off, len);
     }
 
     @Override
@@ -491,7 +511,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final byte[] data,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, extensionRegistry);
+      return (BuilderType) super.mergeFrom(data, extensionRegistry);
     }
 
     @Override
@@ -499,13 +519,13 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final byte[] data, final int off, final int len,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
-      return super.mergeFrom(data, off, len, extensionRegistry);
+      return (BuilderType) super.mergeFrom(data, off, len, extensionRegistry);
     }
 
     @Override
     public BuilderType mergeFrom(final InputStream input)
         throws IOException {
-      return super.mergeFrom(input);
+      return (BuilderType) super.mergeFrom(input);
     }
 
     @Override
@@ -513,7 +533,7 @@ public abstract class AbstractMessage extends AbstractMessageLite
         final InputStream input,
         final ExtensionRegistryLite extensionRegistry)
         throws IOException {
-      return super.mergeFrom(input, extensionRegistry);
+      return (BuilderType) super.mergeFrom(input, extensionRegistry);
     }
 
     @Override

java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java

@@ -43,9 +43,13 @@ import java.util.Collection;
  *
  * @author kenton@google.com Kenton Varda
  */
-public abstract class AbstractMessageLite implements MessageLite {
+public abstract class AbstractMessageLite<
+    MessageType extends AbstractMessageLite<MessageType, BuilderType>,
+    BuilderType extends AbstractMessageLite.Builder<MessageType, BuilderType>> 
+        implements MessageLite {
   protected int memoizedHashCode = 0;
-
+  
+  @Override
   public ByteString toByteString() {
     try {
       final ByteString.CodedBuilder out =
@@ -59,6 +63,7 @@ public abstract class AbstractMessageLite implements MessageLite {
     }
   }
 
+  @Override
   public byte[] toByteArray() {
     try {
       final byte[] result = new byte[getSerializedSize()];
@@ -73,6 +78,7 @@ public abstract class AbstractMessageLite implements MessageLite {
     }
   }
 
+  @Override
   public void writeTo(final OutputStream output) throws IOException {
     final int bufferSize =
         CodedOutputStream.computePreferredBufferSize(getSerializedSize());
@@ -82,6 +88,7 @@ public abstract class AbstractMessageLite implements MessageLite {
     codedOutput.flush();
   }
 
+  @Override
   public void writeDelimitedTo(final OutputStream output) throws IOException {
     final int serialized = getSerializedSize();
     final int bufferSize = CodedOutputStream.computePreferredBufferSize(
@@ -120,25 +127,27 @@ public abstract class AbstractMessageLite implements MessageLite {
    * other methods.
    */
   @SuppressWarnings("unchecked")
-  public static abstract class Builder<BuilderType extends Builder>
+  public abstract static class Builder<
+      MessageType extends AbstractMessageLite<MessageType, BuilderType>,
+      BuilderType extends Builder<MessageType, BuilderType>>
       implements MessageLite.Builder {
     // The compiler produces an error if this is not declared explicitly.
     @Override
     public abstract BuilderType clone();
 
-    public BuilderType mergeFrom(final CodedInputStream input)
-                                 throws IOException {
+    @Override
+    public BuilderType mergeFrom(final CodedInputStream input) throws IOException {
       return mergeFrom(input, ExtensionRegistryLite.getEmptyRegistry());
     }
 
     // Re-defined here for return type covariance.
+    @Override
     public abstract BuilderType mergeFrom(
-        final CodedInputStream input,
-        final ExtensionRegistryLite extensionRegistry)
+        final CodedInputStream input, final ExtensionRegistryLite extensionRegistry)
         throws IOException;
 
-    public BuilderType mergeFrom(final ByteString data)
-        throws InvalidProtocolBufferException {
+    @Override
+    public BuilderType mergeFrom(final ByteString data) throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input = data.newCodedInput();
         mergeFrom(input);
@@ -153,9 +162,9 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
+    @Override
     public BuilderType mergeFrom(
-        final ByteString data,
-        final ExtensionRegistryLite extensionRegistry)
+        final ByteString data, final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input = data.newCodedInput();
@@ -171,14 +180,14 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
-    public BuilderType mergeFrom(final byte[] data)
-        throws InvalidProtocolBufferException {
+    @Override
+    public BuilderType mergeFrom(final byte[] data) throws InvalidProtocolBufferException {
       return mergeFrom(data, 0, data.length);
     }
 
-    public BuilderType mergeFrom(final byte[] data, final int off,
-                                 final int len)
-                                 throws InvalidProtocolBufferException {
+    @Override
+    public BuilderType mergeFrom(final byte[] data, final int off, final int len)
+        throws InvalidProtocolBufferException {
       try {
         final CodedInputStream input =
             CodedInputStream.newInstance(data, off, len);
@@ -194,15 +203,17 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
-    public BuilderType mergeFrom(
-        final byte[] data,
-        final ExtensionRegistryLite extensionRegistry)
+    @Override
+    public BuilderType mergeFrom(final byte[] data, final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       return mergeFrom(data, 0, data.length, extensionRegistry);
     }
 
+    @Override
     public BuilderType mergeFrom(
-        final byte[] data, final int off, final int len,
+        final byte[] data,
+        final int off,
+        final int len,
         final ExtensionRegistryLite extensionRegistry)
         throws InvalidProtocolBufferException {
       try {
@@ -220,6 +231,7 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
+    @Override
     public BuilderType mergeFrom(final InputStream input) throws IOException {
       final CodedInputStream codedInput = CodedInputStream.newInstance(input);
       mergeFrom(codedInput);
@@ -227,10 +239,9 @@ public abstract class AbstractMessageLite implements MessageLite {
       return (BuilderType) this;
     }
 
+    @Override
     public BuilderType mergeFrom(
-        final InputStream input,
-        final ExtensionRegistryLite extensionRegistry)
-        throws IOException {
+        final InputStream input, final ExtensionRegistryLite extensionRegistry) throws IOException {
       final CodedInputStream codedInput = CodedInputStream.newInstance(input);
       mergeFrom(codedInput, extensionRegistry);
       codedInput.checkLastTagWas(0);
@@ -292,10 +303,9 @@ public abstract class AbstractMessageLite implements MessageLite {
       }
     }
 
+    @Override
     public boolean mergeDelimitedFrom(
-        final InputStream input,
-        final ExtensionRegistryLite extensionRegistry)
-        throws IOException {
+        final InputStream input, final ExtensionRegistryLite extensionRegistry) throws IOException {
       final int firstByte = input.read();
       if (firstByte == -1) {
         return false;
@@ -306,11 +316,24 @@ public abstract class AbstractMessageLite implements MessageLite {
       return true;
     }
 
-    public boolean mergeDelimitedFrom(final InputStream input)
-        throws IOException {
+    @Override
+    public boolean mergeDelimitedFrom(final InputStream input) throws IOException {
       return mergeDelimitedFrom(input,
           ExtensionRegistryLite.getEmptyRegistry());
     }
+    
+    @Override
+    @SuppressWarnings("unchecked") // isInstance takes care of this
+    public BuilderType mergeFrom(final MessageLite other) {
+      if (!getDefaultInstanceForType().getClass().isInstance(other)) {
+        throw new IllegalArgumentException(
+            "mergeFrom(MessageLite) can only merge messages of the same type.");
+      }
+        
+      return internalMergeFrom((MessageType) other);
+    }
+    
+    protected abstract BuilderType internalMergeFrom(MessageType message);
 
     /**
      * Construct an UninitializedMessageException reporting missing fields in

java/core/src/main/java/com/google/protobuf/AbstractParser.java

@@ -78,26 +78,27 @@ public abstract class AbstractParser<MessageType extends MessageLite>
   private static final ExtensionRegistryLite EMPTY_REGISTRY
       = ExtensionRegistryLite.getEmptyRegistry();
 
+  @Override
   public MessageType parsePartialFrom(CodedInputStream input)
       throws InvalidProtocolBufferException {
     return parsePartialFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(CodedInputStream input,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialFrom(input, extensionRegistry));
   }
 
-  public MessageType parseFrom(CodedInputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(CodedInputStream input) throws InvalidProtocolBufferException {
     return parseFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(ByteString data,
-                                      ExtensionRegistryLite extensionRegistry)
-    throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
     MessageType message;
     try {
       CodedInputStream input = data.newCodedInput();
@@ -113,24 +114,25 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     }
   }
 
-  public MessageType parsePartialFrom(ByteString data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(ByteString data) throws InvalidProtocolBufferException {
     return parsePartialFrom(data, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(ByteString data,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(parsePartialFrom(data, extensionRegistry));
   }
 
-  public MessageType parseFrom(ByteString data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(ByteString data) throws InvalidProtocolBufferException {
     return parseFrom(data, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(byte[] data, int off, int len,
-                                      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parsePartialFrom(
+      byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     try {
       CodedInputStream input = CodedInputStream.newInstance(data, off, len);
@@ -146,47 +148,50 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     }
   }
 
+  @Override
   public MessageType parsePartialFrom(byte[] data, int off, int len)
       throws InvalidProtocolBufferException {
     return parsePartialFrom(data, off, len, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(byte[] data,
-                                      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parsePartialFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return parsePartialFrom(data, 0, data.length, extensionRegistry);
   }
 
-  public MessageType parsePartialFrom(byte[] data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(byte[] data) throws InvalidProtocolBufferException {
     return parsePartialFrom(data, 0, data.length, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(byte[] data, int off, int len,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(
+      byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialFrom(data, off, len, extensionRegistry));
   }
 
+  @Override
   public MessageType parseFrom(byte[] data, int off, int len)
       throws InvalidProtocolBufferException {
     return parseFrom(data, off, len, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(byte[] data,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return parseFrom(data, 0, data.length, extensionRegistry);
   }
 
-  public MessageType parseFrom(byte[] data)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(byte[] data) throws InvalidProtocolBufferException {
     return parseFrom(data, EMPTY_REGISTRY);
   }
 
-  public MessageType parsePartialFrom(InputStream input,
-                                      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parsePartialFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     CodedInputStream codedInput = CodedInputStream.newInstance(input);
     MessageType message = parsePartialFrom(codedInput, extensionRegistry);
@@ -198,26 +203,26 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     return message;
   }
 
-  public MessageType parsePartialFrom(InputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parsePartialFrom(InputStream input) throws InvalidProtocolBufferException {
     return parsePartialFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parseFrom(InputStream input,
-                               ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialFrom(input, extensionRegistry));
   }
 
-  public MessageType parseFrom(InputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseFrom(InputStream input) throws InvalidProtocolBufferException {
     return parseFrom(input, EMPTY_REGISTRY);
   }
 
+  @Override
   public MessageType parsePartialDelimitedFrom(
-      InputStream input,
-      ExtensionRegistryLite extensionRegistry)
+      InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     int size;
     try {
@@ -233,21 +238,21 @@ public abstract class AbstractParser<MessageType extends MessageLite>
     return parsePartialFrom(limitedInput, extensionRegistry);
   }
 
+  @Override
   public MessageType parsePartialDelimitedFrom(InputStream input)
       throws InvalidProtocolBufferException {
     return parsePartialDelimitedFrom(input, EMPTY_REGISTRY);
   }
 
-  public MessageType parseDelimitedFrom(
-      InputStream input,
-      ExtensionRegistryLite extensionRegistry)
+  @Override
+  public MessageType parseDelimitedFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
         parsePartialDelimitedFrom(input, extensionRegistry));
   }
 
-  public MessageType parseDelimitedFrom(InputStream input)
-      throws InvalidProtocolBufferException {
+  @Override
+  public MessageType parseDelimitedFrom(InputStream input) throws InvalidProtocolBufferException {
     return parseDelimitedFrom(input, EMPTY_REGISTRY);
   }
 }

java/core/src/main/java/com/google/protobuf/AbstractProtobufList.java

@@ -34,19 +34,25 @@ import com.google.protobuf.Internal.ProtobufList;
 
 import java.util.AbstractList;
 import java.util.Collection;
+import java.util.List;
+import java.util.RandomAccess;
 
 /**
  * An abstract implementation of {@link ProtobufList} which manages mutability semantics. All mutate
- * methods are check if the list is mutable before proceeding. Subclasses must invoke
+ * methods must check if the list is mutable before proceeding. Subclasses must invoke
  * {@link #ensureIsMutable()} manually when overriding those methods.
+ * <p>
+ * This implementation assumes all subclasses are array based, supporting random access.
  */
 abstract class AbstractProtobufList<E> extends AbstractList<E> implements ProtobufList<E> {
 
+  protected static final int DEFAULT_CAPACITY = 10;
+
   /**
    * Whether or not this list is modifiable.
    */
   private boolean isMutable;
-  
+
   /**
    * Constructs a mutable list by default.
    */
@@ -54,6 +60,44 @@ abstract class AbstractProtobufList<E> extends AbstractList<E> implements Protob
     isMutable = true;
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof List)) {
+      return false;
+    }
+    // Handle lists that do not support RandomAccess as efficiently as possible by using an iterator
+    // based approach in our super class. Otherwise our index based approach will avoid those
+    // allocations.
+    if (!(o instanceof RandomAccess)) {
+      return super.equals(o);
+    }
+
+    List<?> other = (List<?>) o;
+    final int size = size();
+    if (size != other.size()) {
+      return false;
+    }
+    for (int i = 0; i < size; i++) {
+      if (!get(i).equals(other.get(i))) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    final int size = size();
+    int hashCode = 1;
+    for (int i = 0; i < size; i++) {
+      hashCode = (31 * hashCode) + get(i).hashCode();
+    }
+    return hashCode;
+  }
+
   @Override
   public boolean add(E e) {
     ensureIsMutable();

java/core/src/main/java/com/google/protobuf/BooleanArrayList.java

@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.BooleanList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -45,8 +44,6 @@ import java.util.RandomAccess;
 final class BooleanArrayList
     extends AbstractProtobufList<Boolean> implements BooleanList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final BooleanArrayList EMPTY_LIST = new BooleanArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -60,7 +57,7 @@ final class BooleanArrayList
    * The backing store for the list.
    */
   private boolean[] array;
-  
+
   /**
    * The size of the list distinct from the length of the array. That is, it is the number of
    * elements set in the list.
@@ -71,35 +68,57 @@ final class BooleanArrayList
    * Constructs a new mutable {@code BooleanArrayList} with default capacity.
    */
   BooleanArrayList() {
-    this(DEFAULT_CAPACITY);
+    this(new boolean[DEFAULT_CAPACITY], 0);
   }
 
   /**
-   * Constructs a new mutable {@code BooleanArrayList} with the provided capacity.
+   * Constructs a new mutable {@code BooleanArrayList}.
    */
-  BooleanArrayList(int capacity) {
-    array = new boolean[capacity];
-    size = 0;
+  private BooleanArrayList(boolean[] array, int size) {
+    this.array = array;
+    this.size = size;
   }
-
-  /**
-   * Constructs a new mutable {@code BooleanArrayList} containing the same elements as
-   * {@code other}.
-   */
-  BooleanArrayList(List<Boolean> other) {
-    if (other instanceof BooleanArrayList) {
-      BooleanArrayList list = (BooleanArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new boolean[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof BooleanArrayList)) {
+      return super.equals(o);
+    }
+    BooleanArrayList other = (BooleanArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final boolean[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
   }
-  
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + Internal.hashBoolean(array[i]);
+    }
+    return result;
+  }
+
+  @Override
+  public BooleanList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new BooleanArrayList(Arrays.copyOf(array, capacity), size);
+  }
+
   @Override
   public Boolean get(int index) {
     return getBoolean(index);

java/core/src/main/java/com/google/protobuf/ByteBufferWriter.java

@@ -0,0 +1,145 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.lang.Math.max;
+import static java.lang.Math.min;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.ref.SoftReference;
+import java.nio.ByteBuffer;
+
+/**
+ * Utility class to provide efficient writing of {@link ByteBuffer}s to {@link OutputStream}s.
+ */
+final class ByteBufferWriter {
+  private ByteBufferWriter() {}
+
+  /**
+   * Minimum size for a cached buffer. This prevents us from allocating buffers that are too
+   * small to be easily reused.
+   */
+  // TODO(nathanmittler): tune this property or allow configuration?
+  private static final int MIN_CACHED_BUFFER_SIZE = 1024;
+
+  /**
+   * Maximum size for a cached buffer. If a larger buffer is required, it will be allocated
+   * but not cached.
+   */
+  // TODO(nathanmittler): tune this property or allow configuration?
+  private static final int MAX_CACHED_BUFFER_SIZE = 16 * 1024;
+
+  /**
+   * The fraction of the requested buffer size under which the buffer will be reallocated.
+   */
+  // TODO(nathanmittler): tune this property or allow configuration?
+  private static final float BUFFER_REALLOCATION_THRESHOLD = 0.5f;
+
+  /**
+   * Keeping a soft reference to a thread-local buffer. This buffer is used for writing a
+   * {@link ByteBuffer} to an {@link OutputStream} when no zero-copy alternative was available.
+   * Using a "soft" reference since VMs may keep this reference around longer than "weak"
+   * (e.g. HotSpot will maintain soft references until memory pressure warrants collection).
+   */
+  private static final ThreadLocal<SoftReference<byte[]>> BUFFER =
+      new ThreadLocal<SoftReference<byte[]>>();
+
+  /**
+   * For testing purposes only. Clears the cached buffer to force a new allocation on the next
+   * invocation.
+   */
+  static void clearCachedBuffer() {
+    BUFFER.set(null);
+  }
+
+  /**
+   * Writes the remaining content of the buffer to the given stream. The buffer {@code position}
+   * will remain unchanged by this method.
+   */
+  static void write(ByteBuffer buffer, OutputStream output) throws IOException {
+    final int initialPos = buffer.position();
+    try {
+      if (buffer.hasArray()) {
+        // Optimized write for array-backed buffers.
+        // Note that we're taking the risk that a malicious OutputStream could modify the array.
+        output.write(buffer.array(), buffer.arrayOffset() + buffer.position(), buffer.remaining());
+      } else if (output instanceof FileOutputStream) {
+        // Use a channel to write out the ByteBuffer. This will automatically empty the buffer.
+        ((FileOutputStream) output).getChannel().write(buffer);
+      } else {
+        // Read all of the data from the buffer to an array.
+        // TODO(nathanmittler): Consider performance improvements for other "known" stream types.
+        final byte[] array = getOrCreateBuffer(buffer.remaining());
+        while (buffer.hasRemaining()) {
+          int length = min(buffer.remaining(), array.length);
+          buffer.get(array, 0, length);
+          output.write(array, 0, length);
+        }
+      }
+    } finally {
+      // Restore the initial position.
+      buffer.position(initialPos);
+    }
+  }
+
+  private static byte[] getOrCreateBuffer(int requestedSize) {
+    requestedSize = max(requestedSize, MIN_CACHED_BUFFER_SIZE);
+
+    byte[] buffer = getBuffer();
+    // Only allocate if we need to.
+    if (buffer == null || needToReallocate(requestedSize, buffer.length)) {
+      buffer = new byte[requestedSize];
+
+      // Only cache the buffer if it's not too big.
+      if (requestedSize <= MAX_CACHED_BUFFER_SIZE) {
+        setBuffer(buffer);
+      }
+    }
+    return buffer;
+  }
+
+  private static boolean needToReallocate(int requestedSize, int bufferLength) {
+    // First check against just the requested length to avoid the multiply.
+    return bufferLength < requestedSize
+        && bufferLength < requestedSize * BUFFER_REALLOCATION_THRESHOLD;
+  }
+
+  private static byte[] getBuffer() {
+    SoftReference<byte[]> sr = BUFFER.get();
+    return sr == null ? null : sr.get();
+  }
+
+  private static void setBuffer(byte[] value) {
+    BUFFER.set(new SoftReference<byte[]>(value));
+  }
+}

java/core/src/main/java/com/google/protobuf/ByteOutput.java

@@ -0,0 +1,116 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * An output target for raw bytes. This interface provides semantics that support two types of
+ * writing:
+ *
+ * <p/><b>Traditional write operations:</b>
+ * (as defined by {@link java.io.OutputStream}) where the target method is responsible for either
+ * copying the data or completing the write before returning from the method call.
+ *
+ * <p/><b>Lazy write operations:</b> where the caller guarantees that it will never modify the
+ * provided buffer and it can therefore be considered immutable. The target method is free to
+ * maintain a reference to the buffer beyond the scope of the method call (e.g. until the write
+ * operation completes).
+ */
+@ExperimentalApi
+public abstract class ByteOutput {
+  /**
+   * Writes a single byte.
+   *
+   * @param value the byte to be written
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void write(byte value) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} must copy {@code value} if it will
+   * not be processed prior to the return of this method call, since {@code value} may be
+   * reused/altered by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written
+   * @param offset the offset of the start of the writable range
+   * @param length the number of bytes to write starting from {@code offset}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void write(byte[] value, int offset, int length) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} is free to retain a reference to the value
+   * beyond the scope of this method call (e.g. write later) since it is considered immutable and is
+   * guaranteed not to change by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written
+   * @param offset the offset of the start of the writable range
+   * @param length the number of bytes to write starting from {@code offset}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void writeLazy(byte[] value, int offset, int length) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} must copy {@code value} if it will
+   * not be processed prior to the return of this method call, since {@code value} may be
+   * reused/altered by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written. Upon returning from this call, the {@code position} of
+   * this buffer will be set to the {@code limit}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void write(ByteBuffer value) throws IOException;
+
+  /**
+   * Writes a sequence of bytes. The {@link ByteOutput} is free to retain a reference to the value
+   * beyond the scope of this method call (e.g. write later) since it is considered immutable and is
+   * guaranteed not to change by the caller.
+   *
+   * <p>NOTE: This method <strong>MUST NOT</strong> modify the {@code value}. Doing so is a
+   * programming error and will lead to data corruption which will be difficult to debug.
+   *
+   * @param value the bytes to be written. Upon returning from this call, the {@code position} of
+   * this buffer will be set to the {@code limit}
+   * @throws IOException thrown if an error occurred while writing
+   */
+  public abstract void writeLazy(ByteBuffer value) throws IOException;
+}

java/core/src/main/java/com/google/protobuf/ByteString.java

@@ -1,4 +1,32 @@
-// Copyright 2007 Google Inc.  All rights reserved.
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 package com.google.protobuf;
 
@@ -15,6 +43,7 @@ import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.nio.charset.UnsupportedCharsetException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
@@ -58,6 +87,54 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * Empty {@code ByteString}.
    */
   public static final ByteString EMPTY = new LiteralByteString(Internal.EMPTY_BYTE_ARRAY);
+  
+  /** 
+   * An interface to efficiently copy {@code byte[]}.
+   * 
+   * <p>One of the noticable costs of copying a byte[] into a new array using 
+   * {@code System.arraycopy} is nullification of a new buffer before the copy. It has been shown 
+   * the Hotspot VM is capable to intrisicfy {@code Arrays.copyOfRange} operation to avoid this
+   * expensive nullification and provide substantial performance gain. Unfortunately this does not
+   * hold on Android runtimes and could make the copy slightly slower due to additional code in
+   * the {@code Arrays.copyOfRange}. Thus we provide two different implementation for array copier
+   * for Hotspot and Android runtimes. 
+   */
+  private interface ByteArrayCopier {
+    /**
+     * Copies the specified range of the specified array into a new array
+     */
+    byte[] copyFrom(byte[] bytes, int offset, int size);
+  }
+  
+  /** Implementation of {@code ByteArrayCopier} which uses {@link System#arraycopy}. */
+  private static final class SystemByteArrayCopier implements ByteArrayCopier {
+    @Override
+    public byte[] copyFrom(byte[] bytes, int offset, int size) {
+      byte[] copy = new byte[size];
+      System.arraycopy(bytes, offset, copy, 0, size);
+      return copy;
+    }
+  }
+  
+  /** Implementation of {@code ByteArrayCopier} which uses {@link Arrays#copyOfRange}. */
+  private static final class ArraysByteArrayCopier implements ByteArrayCopier {
+    @Override
+    public byte[] copyFrom(byte[] bytes, int offset, int size) {
+      return Arrays.copyOfRange(bytes, offset, offset + size);
+    }
+  }
+  
+  private static final ByteArrayCopier byteArrayCopier;
+  static {
+    boolean isAndroid = true;
+    try {
+      Class.forName("android.content.Context");
+    } catch (ClassNotFoundException e) {
+      isAndroid = false;
+    }
+    
+    byteArrayCopier = isAndroid ? new SystemByteArrayCopier() : new ArraysByteArrayCopier();
+  }
 
   /**
    * Cached hash value. Intentionally accessed via a data race, which
@@ -77,7 +154,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @param index index of byte
    * @return the value
-   * @throws ArrayIndexOutOfBoundsException {@code index < 0 or index >= size}
+   * @throws IndexOutOfBoundsException {@code index < 0 or index >= size}
    */
   public abstract byte byteAt(int index);
 
@@ -109,7 +186,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
       public byte nextByte() {
         try {
           return byteAt(position++);
-        } catch (ArrayIndexOutOfBoundsException e) {
+        } catch (IndexOutOfBoundsException e) {
           throw new NoSuchElementException(e.getMessage());
         }
       }
@@ -220,9 +297,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @return new {@code ByteString}
    */
   public static ByteString copyFrom(byte[] bytes, int offset, int size) {
-    byte[] copy = new byte[size];
-    System.arraycopy(bytes, offset, copy, 0, size);
-    return new LiteralByteString(copy);
+    return new LiteralByteString(byteArrayCopier.copyFrom(bytes, offset, size));
   }
 
   /**
@@ -559,12 +634,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
   }
 
   /**
-   * Writes the complete contents of this byte string to
-   * the specified output stream argument.
-   *
-   * <p>It is assumed that the {@link OutputStream} will not modify the contents passed it
-   * it. It may be possible for a malicious {@link OutputStream} to corrupt
-   * the data underlying the {@link ByteString}.
+   * Writes a copy of the contents of this byte string to the specified output stream argument.
    *
    * @param  out  the output stream to which to write the data.
    * @throws IOException  if an I/O error occurs.
@@ -578,8 +648,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @param  sourceOffset offset within these bytes
    * @param  numberToWrite number of bytes to write
    * @throws IOException  if an I/O error occurs.
-   * @throws IndexOutOfBoundsException if an offset or size is negative or too
-   *     large
+   * @throws IndexOutOfBoundsException if an offset or size is negative or too large
    */
   final void writeTo(OutputStream out, int sourceOffset, int numberToWrite)
       throws IOException {
@@ -596,6 +665,20 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
   abstract void writeToInternal(OutputStream out, int sourceOffset, int numberToWrite)
       throws IOException;
 
+  /**
+   * Writes this {@link ByteString} to the provided {@link ByteOutput}. Calling
+   * this method may result in multiple operations on the target {@link ByteOutput}.
+   *
+   * <p>This method may expose internal backing buffers of the {@link ByteString} to the {@link
+   * ByteOutput} in order to avoid additional copying overhead. It would be possible for a malicious
+   * {@link ByteOutput} to corrupt the {@link ByteString}. Use with caution!
+   *
+   * @param  byteOutput  the output target to receive the bytes
+   * @throws IOException  if an I/O error occurs
+   * @see UnsafeByteOperations#unsafeWriteTo(ByteString, ByteOutput)
+   */
+  abstract void writeTo(ByteOutput byteOutput) throws IOException;
+
   /**
    * Constructs a read-only {@code java.nio.ByteBuffer} whose content
    * is equal to the contents of this byte string.
@@ -1102,7 +1185,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    *
    * @param index the index position to be tested
    * @param size the length of the array
-   * @throws ArrayIndexOutOfBoundsException if the index does not fall within the array.
+   * @throws IndexOutOfBoundsException if the index does not fall within the array.
    */
   static void checkIndex(int index, int size) {
     if ((index | (size - (index + 1))) < 0) {
@@ -1120,7 +1203,7 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
    * @param endIndex the end index of the range (exclusive)
    * @param size the size of the array.
    * @return the length of the range.
-   * @throws ArrayIndexOutOfBoundsException some or all of the range falls outside of the array.
+   * @throws IndexOutOfBoundsException some or all of the range falls outside of the array.
    */
   static int checkRange(int startIndex, int endIndex, int size) {
     final int length = endIndex - startIndex;
@@ -1235,6 +1318,11 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
       outputStream.write(bytes, getOffsetIntoBytes() + sourceOffset, numberToWrite);
     }
 
+    @Override
+    final void writeTo(ByteOutput output) throws IOException {
+      output.writeLazy(bytes, getOffsetIntoBytes(), size());
+    }
+
     @Override
     protected final String toStringInternal(Charset charset) {
       return new String(bytes, getOffsetIntoBytes(), size(), charset);

java/core/src/main/java/com/google/protobuf/CodedInputStream.java

@@ -55,7 +55,14 @@ public final class CodedInputStream {
    * Create a new CodedInputStream wrapping the given InputStream.
    */
   public static CodedInputStream newInstance(final InputStream input) {
-    return new CodedInputStream(input);
+    return new CodedInputStream(input, BUFFER_SIZE);
+  }
+  
+  /**
+   * Create a new CodedInputStream wrapping the given InputStream.
+   */
+  static CodedInputStream newInstance(final InputStream input, int bufferSize) {
+    return new CodedInputStream(input, bufferSize);
   }
 
   /**
@@ -70,14 +77,14 @@ public final class CodedInputStream {
    */
   public static CodedInputStream newInstance(final byte[] buf, final int off,
                                              final int len) {
-    return newInstance(buf, off, len, false);
+    return newInstance(buf, off, len, false /* bufferIsImmutable */);
   }
-
+  
   /**
    * Create a new CodedInputStream wrapping the given byte array slice.
    */
-  public static CodedInputStream newInstance(final byte[] buf, final int off,
-                                             final int len, boolean bufferIsImmutable) {
+  static CodedInputStream newInstance(
+      final byte[] buf, final int off, final int len, final boolean bufferIsImmutable) {
     CodedInputStream result = new CodedInputStream(buf, off, len, bufferIsImmutable);
     try {
       // Some uses of CodedInputStream can be more efficient if they know
@@ -361,6 +368,11 @@ public final class CodedInputStream {
       return result;
     } else if (size == 0) {
       return "";
+    } else if (size <= bufferSize) {
+      refillBuffer(size);
+      String result = new String(buffer, bufferPos, size, Internal.UTF_8);
+      bufferPos += size;
+      return result;
     } else {
       // Slow path:  Build a byte array first then copy it.
       return new String(readRawBytesSlowPath(size), Internal.UTF_8);
@@ -375,14 +387,21 @@ public final class CodedInputStream {
   public String readStringRequireUtf8() throws IOException {
     final int size = readRawVarint32();
     final byte[] bytes;
-    int pos = bufferPos;
-    if (size <= (bufferSize - pos) && size > 0) {
+    final int oldPos = bufferPos;
+    final int pos;
+    if (size <= (bufferSize - oldPos) && size > 0) {
       // Fast path:  We already have the bytes in a contiguous buffer, so
       //   just copy directly from it.
       bytes = buffer;
-      bufferPos = pos + size;
+      bufferPos = oldPos + size;
+      pos = oldPos;
     } else if (size == 0) {
       return "";
+    } else if (size <= bufferSize) {
+      refillBuffer(size);
+      bytes = buffer;
+      pos = 0;
+      bufferPos = pos + size;
     } else {
       // Slow path:  Build a byte array first then copy it.
       bytes = readRawBytesSlowPath(size);
@@ -869,7 +888,8 @@ public final class CodedInputStream {
   private static final int DEFAULT_SIZE_LIMIT = 64 << 20;  // 64MB
   private static final int BUFFER_SIZE = 4096;
 
-  private CodedInputStream(final byte[] buffer, final int off, final int len, boolean bufferIsImmutable) {
+  private CodedInputStream(
+      final byte[] buffer, final int off, final int len, boolean bufferIsImmutable) {
     this.buffer = buffer;
     bufferSize = off + len;
     bufferPos = off;
@@ -878,8 +898,8 @@ public final class CodedInputStream {
     this.bufferIsImmutable = bufferIsImmutable;
   }
 
-  private CodedInputStream(final InputStream input) {
-    buffer = new byte[BUFFER_SIZE];
+  private CodedInputStream(final InputStream input, int bufferSize) {
+    buffer = new byte[bufferSize];
     bufferSize = 0;
     bufferPos = 0;
     totalBytesRetired = 0;

java/core/src/main/java/com/google/protobuf/Descriptors.java

@@ -74,16 +74,28 @@ public final class Descriptors {
    */
   public static final class FileDescriptor extends GenericDescriptor {
     /** Convert the descriptor to its protocol message representation. */
-    public FileDescriptorProto toProto() { return proto; }
+    @Override
+    public FileDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the file name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /** Returns this object. */
-    public FileDescriptor getFile() { return this; }
+    @Override
+    public FileDescriptor getFile() {
+      return this;
+    }
 
     /** Returns the same as getName(). */
-    public String getFullName() { return proto.getName(); }
+    @Override
+    public String getFullName() {
+      return proto.getName();
+    }
 
     /**
      * Get the proto package name.  This is the package name given by the
@@ -272,7 +284,7 @@ public final class Descriptors {
      *           because a field has an undefined type or because two messages
      *           were defined with the same name.
      */
-    private static FileDescriptor buildFrom(
+    public static FileDescriptor buildFrom(
         final FileDescriptorProto proto, final FileDescriptor[] dependencies,
         final boolean allowUnknownDependencies)
         throws DescriptorValidationException {
@@ -582,10 +594,16 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public DescriptorProto toProto() { return proto; }
+    @Override
+    public DescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the type's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the type's fully-qualified name, within the proto language's
@@ -598,10 +616,16 @@ public final class Descriptors {
      * </pre>
      * {@code Baz}'s full name is "foo.bar.Baz".
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** If this is a nested type, get the outer descriptor, otherwise null. */
     public Descriptor getContainingType() { return containingType; }
@@ -875,19 +899,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public FieldDescriptorProto toProto() { return proto; }
+    @Override
+    public FieldDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the field's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /** Get the field's number. */
-    public int getNumber() { return proto.getNumber(); }
+    @Override
+    public int getNumber() {
+      return proto.getNumber();
+    }
 
     /**
      * Get the field's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the JSON name of this field. */
     public String getJsonName() {
@@ -901,17 +937,22 @@ public final class Descriptors {
     public JavaType getJavaType() { return type.getJavaType(); }
 
     /** For internal use only. */
+    @Override
     public WireFormat.JavaType getLiteJavaType() {
       return getLiteType().getJavaType();
     }
 
     /** Get the {@code FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the field's declared type. */
     public Type getType() { return type; }
 
     /** For internal use only. */
+    @Override
     public WireFormat.FieldType getLiteType() {
       return table[type.ordinal()];
     }
@@ -953,6 +994,7 @@ public final class Descriptors {
     }
 
     /** Is this field declared repeated? */
+    @Override
     public boolean isRepeated() {
       return proto.getLabel() == FieldDescriptorProto.Label.LABEL_REPEATED;
     }
@@ -960,6 +1002,7 @@ public final class Descriptors {
     /** Does this field have the {@code [packed = true]} option or is this field
      *  packable in proto3 and not explicitly setted to unpacked?
      */
+    @Override
     public boolean isPacked() {
       if (!isPackable()) {
         return false;
@@ -1048,6 +1091,7 @@ public final class Descriptors {
     }
 
     /** For enum fields, gets the field's type. */
+    @Override
     public EnumDescriptor getEnumType() {
       if (getJavaType() != JavaType.ENUM) {
         throw new UnsupportedOperationException(
@@ -1066,6 +1110,7 @@ public final class Descriptors {
      * @return negative, zero, or positive if {@code this} is less than,
      *         equal to, or greater than {@code other}, respectively.
      */
+    @Override
     public int compareTo(final FieldDescriptor other) {
       if (other.containingType != containingType) {
         throw new IllegalArgumentException(
@@ -1123,7 +1168,7 @@ public final class Descriptors {
       private JavaType javaType;
 
       public FieldDescriptorProto.Type toProto() {
-        return FieldDescriptorProto.Type.valueOf(ordinal() + 1);
+        return FieldDescriptorProto.Type.forNumber(ordinal() + 1);
       }
       public JavaType getJavaType() { return javaType; }
 
@@ -1466,8 +1511,8 @@ public final class Descriptors {
      * For internal use only.  This is to satisfy the FieldDescriptorLite
      * interface.
      */
-    public MessageLite.Builder internalMergeFrom(
-        MessageLite.Builder to, MessageLite from) {
+    @Override
+    public MessageLite.Builder internalMergeFrom(MessageLite.Builder to, MessageLite from) {
       // FieldDescriptors are only used with non-lite messages so we can just
       // down-cast and call mergeFrom directly.
       return ((Message.Builder) to).mergeFrom((Message) from);
@@ -1487,19 +1532,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public EnumDescriptorProto toProto() { return proto; }
+    @Override
+    public EnumDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the type's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the type's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** If this is a nested type, get the outer descriptor, otherwise null. */
     public Descriptor getContainingType() { return containingType; }
@@ -1533,6 +1590,7 @@ public final class Descriptors {
      * @param number The value's number.
      * @return the value's descriptor, or {@code null} if not found.
      */
+    @Override
     public EnumValueDescriptor findValueByNumber(final int number) {
       return file.pool.enumValuesByNumber.get(
         new DescriptorPool.DescriptorIntPair(this, number));
@@ -1659,13 +1717,22 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public EnumValueDescriptorProto toProto() { return proto; }
+    @Override
+    public EnumValueDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the value's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /** Get the value's number. */
-    public int getNumber() { return proto.getNumber(); }
+    @Override
+    public int getNumber() {
+      return proto.getNumber();
+    }
 
     @Override
     public String toString() { return proto.getName(); }
@@ -1674,10 +1741,16 @@ public final class Descriptors {
      * Get the value's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the value's enum type. */
     public EnumDescriptor getType() { return type; }
@@ -1745,19 +1818,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public ServiceDescriptorProto toProto() { return proto; }
+    @Override
+    public ServiceDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the type's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the type's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the {@code ServiceOptions}, defined in {@code descriptor.proto}. */
     public ServiceOptions getOptions() { return proto.getOptions(); }
@@ -1835,19 +1920,31 @@ public final class Descriptors {
     public int getIndex() { return index; }
 
     /** Convert the descriptor to its protocol message representation. */
-    public MethodDescriptorProto toProto() { return proto; }
+    @Override
+    public MethodDescriptorProto toProto() {
+      return proto;
+    }
 
     /** Get the method's unqualified name. */
-    public String getName() { return proto.getName(); }
+    @Override
+    public String getName() {
+      return proto.getName();
+    }
 
     /**
      * Get the method's fully-qualified name.
      * @see Descriptors.Descriptor#getFullName()
      */
-    public String getFullName() { return fullName; }
+    @Override
+    public String getFullName() {
+      return fullName;
+    }
 
     /** Get the {@link FileDescriptor} containing this descriptor. */
-    public FileDescriptor getFile() { return file; }
+    @Override
+    public FileDescriptor getFile() {
+      return file;
+    }
 
     /** Get the method's service type. */
     public ServiceDescriptor getService() { return service; }
@@ -2248,10 +2345,22 @@ public final class Descriptors {
      * that has the same name as an existing package.
      */
     private static final class PackageDescriptor extends GenericDescriptor {
-      public Message toProto()        { return file.toProto(); }
-      public String getName()         { return name;           }
-      public String getFullName()     { return fullName;       }
-      public FileDescriptor getFile() { return file;           }
+      @Override
+      public Message toProto() {
+        return file.toProto();
+      }
+      @Override
+      public String getName() {
+        return name;
+      }
+      @Override
+      public String getFullName() {
+        return fullName;
+      }
+      @Override
+      public FileDescriptor getFile() {
+        return file;
+      }
 
       PackageDescriptor(final String name, final String fullName,
                         final FileDescriptor file) {

java/core/src/main/java/com/google/protobuf/DoubleArrayList.java

@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.DoubleList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -45,8 +44,6 @@ import java.util.RandomAccess;
 final class DoubleArrayList
     extends AbstractProtobufList<Double> implements DoubleList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final DoubleArrayList EMPTY_LIST = new DoubleArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -71,32 +68,56 @@ final class DoubleArrayList
    * Constructs a new mutable {@code DoubleArrayList} with default capacity.
    */
   DoubleArrayList() {
-    this(DEFAULT_CAPACITY);
-  }
-
-  /**
-   * Constructs a new mutable {@code DoubleArrayList} with the provided capacity.
-   */
-  DoubleArrayList(int capacity) {
-    array = new double[capacity];
-    size = 0;
+    this(new double[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code DoubleArrayList} containing the same elements as {@code other}.
    */
-  DoubleArrayList(List<Double> other) {
-    if (other instanceof DoubleArrayList) {
-      DoubleArrayList list = (DoubleArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new double[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private DoubleArrayList(double[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof DoubleArrayList)) {
+      return super.equals(o);
+    }
+    DoubleArrayList other = (DoubleArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final double[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      long bits = Double.doubleToLongBits(array[i]);
+      result = (31 * result) + Internal.hashLong(bits);
+    }
+    return result;
+  }
+
+  @Override
+  public DoubleList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new DoubleArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override

java/core/src/main/java/com/google/protobuf/DynamicMessage.java

@@ -156,18 +156,22 @@ public final class DynamicMessage extends AbstractMessage {
   // -----------------------------------------------------------------
   // Implementation of Message interface.
 
+  @Override
   public Descriptor getDescriptorForType() {
     return type;
   }
 
+  @Override
   public DynamicMessage getDefaultInstanceForType() {
     return getDefaultInstance(type);
   }
 
+  @Override
   public Map<FieldDescriptor, Object> getAllFields() {
     return fields.getAllFields();
   }
 
+  @Override
   public boolean hasOneof(OneofDescriptor oneof) {
     verifyOneofContainingType(oneof);
     FieldDescriptor field = oneofCases[oneof.getIndex()];
@@ -177,16 +181,19 @@ public final class DynamicMessage extends AbstractMessage {
     return true;
   }
 
+  @Override
   public FieldDescriptor getOneofFieldDescriptor(OneofDescriptor oneof) {
     verifyOneofContainingType(oneof);
     return oneofCases[oneof.getIndex()];
   }
 
+  @Override
   public boolean hasField(FieldDescriptor field) {
     verifyContainingType(field);
     return fields.hasField(field);
   }
 
+  @Override
   public Object getField(FieldDescriptor field) {
     verifyContainingType(field);
     Object result = fields.getField(field);
@@ -202,16 +209,19 @@ public final class DynamicMessage extends AbstractMessage {
     return result;
   }
 
+  @Override
   public int getRepeatedFieldCount(FieldDescriptor field) {
     verifyContainingType(field);
     return fields.getRepeatedFieldCount(field);
   }
 
+  @Override
   public Object getRepeatedField(FieldDescriptor field, int index) {
     verifyContainingType(field);
     return fields.getRepeatedField(field, index);
   }
 
+  @Override
   public UnknownFieldSet getUnknownFields() {
     return unknownFields;
   }
@@ -264,19 +274,22 @@ public final class DynamicMessage extends AbstractMessage {
     return size;
   }
 
+  @Override
   public Builder newBuilderForType() {
     return new Builder(type);
   }
 
+  @Override
   public Builder toBuilder() {
     return newBuilderForType().mergeFrom(this);
   }
 
+  @Override
   public Parser<DynamicMessage> getParserForType() {
     return new AbstractParser<DynamicMessage>() {
+      @Override
       public DynamicMessage parsePartialFrom(
-          CodedInputStream input,
-          ExtensionRegistryLite extensionRegistry)
+          CodedInputStream input, ExtensionRegistryLite extensionRegistry)
           throws InvalidProtocolBufferException {
         Builder builder = newBuilder(type);
         try {
@@ -370,6 +383,7 @@ public final class DynamicMessage extends AbstractMessage {
       }
     }
 
+    @Override
     public DynamicMessage build() {
       if (!isInitialized()) {
         throw newUninitializedMessageException(
@@ -394,6 +408,7 @@ public final class DynamicMessage extends AbstractMessage {
       return buildPartial();
     }
 
+    @Override
     public DynamicMessage buildPartial() {
       fields.makeImmutable();
       DynamicMessage result =
@@ -411,22 +426,27 @@ public final class DynamicMessage extends AbstractMessage {
       return result;
     }
 
+    @Override
     public boolean isInitialized() {
       return DynamicMessage.isInitialized(type, fields);
     }
 
+    @Override
     public Descriptor getDescriptorForType() {
       return type;
     }
 
+    @Override
     public DynamicMessage getDefaultInstanceForType() {
       return getDefaultInstance(type);
     }
 
+    @Override
     public Map<FieldDescriptor, Object> getAllFields() {
       return fields.getAllFields();
     }
 
+    @Override
     public Builder newBuilderForField(FieldDescriptor field) {
       verifyContainingType(field);
 
@@ -438,6 +458,7 @@ public final class DynamicMessage extends AbstractMessage {
       return new Builder(field.getMessageType());
     }
 
+    @Override
     public boolean hasOneof(OneofDescriptor oneof) {
       verifyOneofContainingType(oneof);
       FieldDescriptor field = oneofCases[oneof.getIndex()];
@@ -447,11 +468,13 @@ public final class DynamicMessage extends AbstractMessage {
       return true;
     }
 
+    @Override
     public FieldDescriptor getOneofFieldDescriptor(OneofDescriptor oneof) {
       verifyOneofContainingType(oneof);
       return oneofCases[oneof.getIndex()];
     }
 
+    @Override
     public Builder clearOneof(OneofDescriptor oneof) {
       verifyOneofContainingType(oneof);
       FieldDescriptor field = oneofCases[oneof.getIndex()];
@@ -461,11 +484,13 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public boolean hasField(FieldDescriptor field) {
       verifyContainingType(field);
       return fields.hasField(field);
     }
 
+    @Override
     public Object getField(FieldDescriptor field) {
       verifyContainingType(field);
       Object result = fields.getField(field);
@@ -481,6 +506,7 @@ public final class DynamicMessage extends AbstractMessage {
       return result;
     }
 
+    @Override
     public Builder setField(FieldDescriptor field, Object value) {
       verifyContainingType(field);
       ensureIsMutable();
@@ -505,6 +531,7 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public Builder clearField(FieldDescriptor field) {
       verifyContainingType(field);
       ensureIsMutable();
@@ -519,24 +546,27 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public int getRepeatedFieldCount(FieldDescriptor field) {
       verifyContainingType(field);
       return fields.getRepeatedFieldCount(field);
     }
 
+    @Override
     public Object getRepeatedField(FieldDescriptor field, int index) {
       verifyContainingType(field);
       return fields.getRepeatedField(field, index);
     }
 
-    public Builder setRepeatedField(FieldDescriptor field,
-                                    int index, Object value) {
+    @Override
+    public Builder setRepeatedField(FieldDescriptor field, int index, Object value) {
       verifyContainingType(field);
       ensureIsMutable();
       fields.setRepeatedField(field, index, value);
       return this;
     }
 
+    @Override
     public Builder addRepeatedField(FieldDescriptor field, Object value) {
       verifyContainingType(field);
       ensureIsMutable();
@@ -544,10 +574,12 @@ public final class DynamicMessage extends AbstractMessage {
       return this;
     }
 
+    @Override
     public UnknownFieldSet getUnknownFields() {
       return unknownFields;
     }
 
+    @Override
     public Builder setUnknownFields(UnknownFieldSet unknownFields) {
       if (getDescriptorForType().getFile().getSyntax()
           == Descriptors.FileDescriptor.Syntax.PROTO3) {

java/core/src/main/java/com/google/protobuf/ExperimentalApi.java

@@ -1,3 +1,33 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 package com.google.protobuf;
 
 import java.lang.annotation.Documented;

java/core/src/main/java/com/google/protobuf/Extension.java

@@ -42,6 +42,7 @@ public abstract class Extension<ContainingType extends MessageLite, Type>
   public abstract Descriptors.FieldDescriptor getDescriptor();
 
   /** Returns whether or not this extension is a Lite Extension. */
+  @Override
   final boolean isLite() {
     return false;
   }

java/core/src/main/java/com/google/protobuf/FieldSet.java

@@ -120,6 +120,25 @@ final class FieldSet<FieldDescriptorType extends
   public boolean isImmutable() {
     return isImmutable;
   }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    
+    if (!(o instanceof FieldSet)) {
+      return false;
+    }
+    
+    FieldSet<?> other = (FieldSet<?>) o;
+    return other.fields.equals(other.fields);
+  }
+  
+  @Override
+  public int hashCode() {
+    return fields.hashCode();
+  }
 
   /**
    * Clones the FieldSet. The returned FieldSet will be mutable even if the

java/core/src/main/java/com/google/protobuf/FloatArrayList.java

@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.FloatList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -44,8 +43,6 @@ import java.util.RandomAccess;
  */
 final class FloatArrayList extends AbstractProtobufList<Float> implements FloatList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final FloatArrayList EMPTY_LIST = new FloatArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -70,32 +67,55 @@ final class FloatArrayList extends AbstractProtobufList<Float> implements FloatL
    * Constructs a new mutable {@code FloatArrayList} with default capacity.
    */
   FloatArrayList() {
-    this(DEFAULT_CAPACITY);
-  }
-
-  /**
-   * Constructs a new mutable {@code FloatArrayList} with the provided capacity.
-   */
-  FloatArrayList(int capacity) {
-    array = new float[capacity];
-    size = 0;
+    this(new float[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code FloatArrayList} containing the same elements as {@code other}.
    */
-  FloatArrayList(List<Float> other) {
-    if (other instanceof FloatArrayList) {
-      FloatArrayList list = (FloatArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new float[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private FloatArrayList(float[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof FloatArrayList)) {
+      return super.equals(o);
+    }
+    FloatArrayList other = (FloatArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final float[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + Float.floatToIntBits(array[i]);
+    }
+    return result;
+  }
+
+  @Override
+  public FloatList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new FloatArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override

java/core/src/main/java/com/google/protobuf/GeneratedMessage.java

@@ -80,6 +80,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     unknownFields = builder.getUnknownFields();
   }
 
+  @Override
   public Parser<? extends GeneratedMessage> getParserForType() {
     throw new UnsupportedOperationException(
         "This is supposed to be overridden by subclasses.");
@@ -102,7 +103,7 @@ public abstract class GeneratedMessage extends AbstractMessage
    */
   protected abstract FieldAccessorTable internalGetFieldAccessorTable();
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Descriptor getDescriptorForType() {
     return internalGetFieldAccessorTable().descriptor;
   }
@@ -191,7 +192,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     return true;
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Map<FieldDescriptor, Object> getAllFields() {
     return Collections.unmodifiableMap(
         getAllFieldsMutable(/* getBytesForString = */ false));
@@ -212,22 +213,22 @@ public abstract class GeneratedMessage extends AbstractMessage
         getAllFieldsMutable(/* getBytesForString = */ true));
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public boolean hasOneof(final OneofDescriptor oneof) {
     return internalGetFieldAccessorTable().getOneof(oneof).has(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public FieldDescriptor getOneofFieldDescriptor(final OneofDescriptor oneof) {
     return internalGetFieldAccessorTable().getOneof(oneof).get(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public boolean hasField(final FieldDescriptor field) {
     return internalGetFieldAccessorTable().getField(field).has(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Object getField(final FieldDescriptor field) {
     return internalGetFieldAccessorTable().getField(field).get(this);
   }
@@ -244,19 +245,19 @@ public abstract class GeneratedMessage extends AbstractMessage
     return internalGetFieldAccessorTable().getField(field).getRaw(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public int getRepeatedFieldCount(final FieldDescriptor field) {
     return internalGetFieldAccessorTable().getField(field)
       .getRepeatedCount(this);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public Object getRepeatedField(final FieldDescriptor field, final int index) {
     return internalGetFieldAccessorTable().getField(field)
       .getRepeated(this, index);
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public UnknownFieldSet getUnknownFields() {
     throw new UnsupportedOperationException(
         "This is supposed to be overridden by subclasses.");
@@ -380,7 +381,7 @@ public abstract class GeneratedMessage extends AbstractMessage
   }
 
   @SuppressWarnings("unchecked")
-  public abstract static class Builder <BuilderType extends Builder>
+  public abstract static class Builder <BuilderType extends Builder<BuilderType>>
       extends AbstractMessage.Builder<BuilderType> {
 
     private BuilderParent builderParent;
@@ -444,6 +445,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * Called by the initialization and clear code paths to allow subclasses to
      * reset any of their builtin fields back to the initial values.
      */
+    @Override
     public BuilderType clear() {
       unknownFields = UnknownFieldSet.getDefaultInstance();
       onChanged();
@@ -457,12 +459,12 @@ public abstract class GeneratedMessage extends AbstractMessage
      */
     protected abstract FieldAccessorTable internalGetFieldAccessorTable();
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Descriptor getDescriptorForType() {
       return internalGetFieldAccessorTable().descriptor;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Map<FieldDescriptor, Object> getAllFields() {
       return Collections.unmodifiableMap(getAllFieldsMutable());
     }
@@ -510,39 +512,38 @@ public abstract class GeneratedMessage extends AbstractMessage
       return result;
     }
 
-    public Message.Builder newBuilderForField(
-        final FieldDescriptor field) {
+    @Override
+    public Message.Builder newBuilderForField(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field).newBuilder();
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Message.Builder getFieldBuilder(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field).getBuilder(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field,
-        int index) {
+    @Override
+    public Message.Builder getRepeatedFieldBuilder(final FieldDescriptor field, int index) {
       return internalGetFieldAccessorTable().getField(field).getRepeatedBuilder(
           this, index);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean hasOneof(final OneofDescriptor oneof) {
       return internalGetFieldAccessorTable().getOneof(oneof).has(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public FieldDescriptor getOneofFieldDescriptor(final OneofDescriptor oneof) {
       return internalGetFieldAccessorTable().getOneof(oneof).get(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean hasField(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field).has(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public Object getField(final FieldDescriptor field) {
       Object object = internalGetFieldAccessorTable().getField(field).get(this);
       if (field.isRepeated()) {
@@ -554,52 +555,52 @@ public abstract class GeneratedMessage extends AbstractMessage
       }
     }
 
-    public BuilderType setField(final FieldDescriptor field,
-                                final Object value) {
+    @Override
+    public BuilderType setField(final FieldDescriptor field, final Object value) {
       internalGetFieldAccessorTable().getField(field).set(this, value);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public BuilderType clearField(final FieldDescriptor field) {
       internalGetFieldAccessorTable().getField(field).clear(this);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public BuilderType clearOneof(final OneofDescriptor oneof) {
       internalGetFieldAccessorTable().getOneof(oneof).clear(this);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public int getRepeatedFieldCount(final FieldDescriptor field) {
       return internalGetFieldAccessorTable().getField(field)
           .getRepeatedCount(this);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public Object getRepeatedField(final FieldDescriptor field,
-                                   final int index) {
+    @Override
+    public Object getRepeatedField(final FieldDescriptor field, final int index) {
       return internalGetFieldAccessorTable().getField(field)
           .getRepeated(this, index);
     }
 
-    public BuilderType setRepeatedField(final FieldDescriptor field,
-                                        final int index, final Object value) {
+    @Override
+    public BuilderType setRepeatedField(
+        final FieldDescriptor field, final int index, final Object value) {
       internalGetFieldAccessorTable().getField(field)
         .setRepeated(this, index, value);
       return (BuilderType) this;
     }
 
-    public BuilderType addRepeatedField(final FieldDescriptor field,
-                                        final Object value) {
+    @Override
+    public BuilderType addRepeatedField(final FieldDescriptor field, final Object value) {
       internalGetFieldAccessorTable().getField(field).addRepeated(this, value);
       return (BuilderType) this;
     }
 
-    public BuilderType setUnknownFields(
-        final UnknownFieldSet unknownFields) {
+    @Override
+    public BuilderType setUnknownFields(final UnknownFieldSet unknownFields) {
       this.unknownFields = unknownFields;
       onChanged();
       return (BuilderType) this;
@@ -616,7 +617,7 @@ public abstract class GeneratedMessage extends AbstractMessage
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public boolean isInitialized() {
       for (final FieldDescriptor field : getDescriptorForType().getFields()) {
         // Check that all required fields are present.
@@ -646,7 +647,7 @@ public abstract class GeneratedMessage extends AbstractMessage
       return true;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final UnknownFieldSet getUnknownFields() {
       return unknownFields;
     }
@@ -670,7 +671,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      */
     private class BuilderParentImpl implements BuilderParent {
 
-      //@Override (Java 1.6 override semantics, but we must support 1.5)
+      @Override
       public void markDirty() {
         onChanged();
       }
@@ -735,6 +736,7 @@ public abstract class GeneratedMessage extends AbstractMessage
   public interface ExtendableMessageOrBuilder<
       MessageType extends ExtendableMessage> extends MessageOrBuilder {
     // Re-define for return type covariance.
+    @Override
     Message getDefaultInstanceForType();
 
     /** Check if a singular extension is present. */
@@ -795,6 +797,8 @@ public abstract class GeneratedMessage extends AbstractMessage
       extends GeneratedMessage
       implements ExtendableMessageOrBuilder<MessageType> {
 
+    private static final long serialVersionUID = 1L;
+
     private final FieldSet<FieldDescriptor> extensions;
 
     protected ExtendableMessage() {
@@ -821,9 +825,8 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -831,7 +834,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extensionLite) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
@@ -842,10 +845,9 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -867,11 +869,10 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get one element of a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extensionLite,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extensionLite, final int index) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1019,7 +1020,9 @@ public abstract class GeneratedMessage extends AbstractMessage
         verifyContainingType(field);
         final Object value = extensions.getField(field);
         if (value == null) {
-          if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
+          if (field.isRepeated()) {
+            return Collections.emptyList();
+          } else if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
             // Lacking an ExtensionRegistry, we have no way to determine the
             // extension's real type, so we return a DynamicMessage.
             return DynamicMessage.getDefaultInstance(field.getMessageType());
@@ -1103,7 +1106,7 @@ public abstract class GeneratedMessage extends AbstractMessage
   @SuppressWarnings("unchecked")
   public abstract static class ExtendableBuilder<
         MessageType extends ExtendableMessage,
-        BuilderType extends ExtendableBuilder>
+        BuilderType extends ExtendableBuilder<MessageType, BuilderType>>
       extends Builder<BuilderType>
       implements ExtendableMessageOrBuilder<MessageType> {
 
@@ -1155,9 +1158,8 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1165,7 +1167,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extensionLite) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
@@ -1176,9 +1178,8 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extensionLite) {
+    @Override
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extensionLite) {
       Extension<MessageType, Type> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1200,10 +1201,9 @@ public abstract class GeneratedMessage extends AbstractMessage
     }
 
     /** Get one element of a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extensionLite,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extensionLite, final int index) {
       Extension<MessageType, List<Type>> extension = checkNotLite(extensionLite);
 
       verifyExtensionContainingType(extension);
@@ -1456,10 +1456,9 @@ public abstract class GeneratedMessage extends AbstractMessage
     // obtained.
     return new GeneratedExtension<ContainingType, Type>(
         new CachedDescriptorRetriever() {
-          //@Override (Java 1.6 override semantics, but we must support 1.5)
+          @Override
           public FieldDescriptor loadDescriptor() {
-            return scope.getDescriptorForType().getExtensions()
-                .get(descriptorIndex);
+            return scope.getDescriptorForType().getExtensions().get(descriptorIndex);
           }
         },
         singularType,
@@ -1487,6 +1486,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     private volatile FieldDescriptor descriptor;
     protected abstract FieldDescriptor loadDescriptor();
 
+    @Override
     public FieldDescriptor getDescriptor() {
       if (descriptor == null) {
         synchronized (this) {
@@ -1516,6 +1516,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     // obtained.
     return new GeneratedExtension<ContainingType, Type>(
         new CachedDescriptorRetriever() {
+          @Override
           protected FieldDescriptor loadDescriptor() {
             return scope.getDescriptorForType().findFieldByName(name);
           }
@@ -1542,17 +1543,18 @@ public abstract class GeneratedMessage extends AbstractMessage
     // used to obtain the extension's FieldDescriptor.
     return new GeneratedExtension<ContainingType, Type>(
         new CachedDescriptorRetriever() {
+          @Override
           protected FieldDescriptor loadDescriptor() {
             try {
-              Class clazz =
-                  singularType.getClassLoader().loadClass(descriptorOuterClass);
-              FileDescriptor file =
-                  (FileDescriptor) clazz.getField("descriptor").get(null);
+              Class clazz = singularType.getClassLoader().loadClass(descriptorOuterClass);
+              FileDescriptor file = (FileDescriptor) clazz.getField("descriptor").get(null);
               return file.findExtensionByName(extensionName);
             } catch (Exception e) {
               throw new RuntimeException(
-                  "Cannot load descriptors: " + descriptorOuterClass +
-                  " is not a valid descriptor class name", e);
+                  "Cannot load descriptors: "
+                      + descriptorOuterClass
+                      + " is not a valid descriptor class name",
+                  e);
             }
           }
         },
@@ -1634,12 +1636,13 @@ public abstract class GeneratedMessage extends AbstractMessage
       if (descriptorRetriever != null) {
         throw new IllegalStateException("Already initialized.");
       }
-      descriptorRetriever = new ExtensionDescriptorRetriever() {
-          //@Override (Java 1.6 override semantics, but we must support 1.5)
-          public FieldDescriptor getDescriptor() {
-            return descriptor;
-          }
-        };
+      descriptorRetriever =
+          new ExtensionDescriptorRetriever() {
+            @Override
+            public FieldDescriptor getDescriptor() {
+              return descriptor;
+            }
+          };
     }
 
     private ExtensionDescriptorRetriever descriptorRetriever;
@@ -1649,6 +1652,7 @@ public abstract class GeneratedMessage extends AbstractMessage
     private final Method enumGetValueDescriptor;
     private final ExtensionType extensionType;
 
+    @Override
     public FieldDescriptor getDescriptor() {
       if (descriptorRetriever == null) {
         throw new IllegalStateException(
@@ -1661,10 +1665,12 @@ public abstract class GeneratedMessage extends AbstractMessage
      * If the extension is an embedded message or group, returns the default
      * instance of the message.
      */
+    @Override
     public Message getMessageDefaultInstance() {
       return messageDefaultInstance;
     }
 
+    @Override
     protected ExtensionType getExtensionType() {
       return extensionType;
     }
@@ -1675,7 +1681,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * EnumValueDescriptors but the native accessors use the generated enum
      * type.
      */
-    // @Override
+    @Override
     @SuppressWarnings("unchecked")
     protected Object fromReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
@@ -1700,7 +1706,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * Like {@link #fromReflectionType(Object)}, but if the type is a repeated
      * type, this converts a single element.
      */
-    // @Override
+    @Override
     protected Object singularFromReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
       switch (descriptor.getJavaType()) {
@@ -1724,7 +1730,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * EnumValueDescriptors but the native accessors use the generated enum
      * type.
      */
-    // @Override
+    @Override
     @SuppressWarnings("unchecked")
     protected Object toReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
@@ -1748,7 +1754,7 @@ public abstract class GeneratedMessage extends AbstractMessage
      * Like {@link #toReflectionType(Object)}, but if the type is a repeated
      * type, this converts a single element.
      */
-    // @Override
+    @Override
     protected Object singularToReflectionType(final Object value) {
       FieldDescriptor descriptor = getDescriptor();
       switch (descriptor.getJavaType()) {
@@ -1759,22 +1765,22 @@ public abstract class GeneratedMessage extends AbstractMessage
       }
     }
 
-    // @Override
+    @Override
     public int getNumber() {
       return getDescriptor().getNumber();
     }
 
-    // @Override
+    @Override
     public WireFormat.FieldType getLiteType() {
       return getDescriptor().getLiteType();
     }
 
-    // @Override
+    @Override
     public boolean isRepeated() {
       return getDescriptor().isRepeated();
     }
 
-    // @Override
+    @Override
     @SuppressWarnings("unchecked")
     public Type getDefaultValue() {
       if (isRepeated()) {
@@ -2124,49 +2130,57 @@ public abstract class GeneratedMessage extends AbstractMessage
         return ((Internal.EnumLite) invokeOrDie(caseMethodBuilder, builder)).getNumber();
       }
 
+      @Override
       public Object get(final GeneratedMessage message) {
         return invokeOrDie(getMethod, message);
       }
+      @Override
       public Object get(GeneratedMessage.Builder builder) {
         return invokeOrDie(getMethodBuilder, builder);
       }
+      @Override
       public Object getRaw(final GeneratedMessage message) {
         return get(message);
       }
+      @Override
       public Object getRaw(GeneratedMessage.Builder builder) {
         return get(builder);
       }
+      @Override
       public void set(final Builder builder, final Object value) {
         invokeOrDie(setMethod, builder, value);
       }
-      public Object getRepeated(final GeneratedMessage message,
-                                final int index) {
+      @Override
+      public Object getRepeated(final GeneratedMessage message, final int index) {
         throw new UnsupportedOperationException(
           "getRepeatedField() called on a singular field.");
       }
-      public Object getRepeatedRaw(final GeneratedMessage message,
-                                final int index) {
+      @Override
+      public Object getRepeatedRaw(final GeneratedMessage message, final int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldRaw() called on a singular field.");
       }
+      @Override
       public Object getRepeated(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedField() called on a singular field.");
       }
-      public Object getRepeatedRaw(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Object getRepeatedRaw(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldRaw() called on a singular field.");
       }
-      public void setRepeated(final Builder builder, final int index,
-          final Object value) {
+      @Override
+      public void setRepeated(final Builder builder, final int index, final Object value) {
         throw new UnsupportedOperationException(
           "setRepeatedField() called on a singular field.");
       }
+      @Override
       public void addRepeated(final Builder builder, final Object value) {
         throw new UnsupportedOperationException(
           "addRepeatedField() called on a singular field.");
       }
+      @Override
       public boolean has(final GeneratedMessage message) {
         if (!hasHasMethod) {
           if (isOneofField) {
@@ -2176,6 +2190,7 @@ public abstract class GeneratedMessage extends AbstractMessage
         }
         return (Boolean) invokeOrDie(hasMethod, message);
       }
+      @Override
       public boolean has(GeneratedMessage.Builder builder) {
         if (!hasHasMethod) {
           if (isOneofField) {
@@ -2185,27 +2200,32 @@ public abstract class GeneratedMessage extends AbstractMessage
         }
         return (Boolean) invokeOrDie(hasMethodBuilder, builder);
       }
+      @Override
       public int getRepeatedCount(final GeneratedMessage message) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldSize() called on a singular field.");
       }
+      @Override
       public int getRepeatedCount(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldSize() called on a singular field.");
       }
+      @Override
       public void clear(final Builder builder) {
         invokeOrDie(clearMethod, builder);
       }
+      @Override
       public Message.Builder newBuilder() {
         throw new UnsupportedOperationException(
           "newBuilderForField() called on a non-Message type.");
       }
+      @Override
       public Message.Builder getBuilder(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "getFieldBuilder() called on a non-Message type.");
       }
-      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldBuilder() called on a non-Message type.");
       }
@@ -2249,18 +2269,23 @@ public abstract class GeneratedMessage extends AbstractMessage
         clearMethod = getMethodOrDie(builderClass, "clear" + camelCaseName);
       }
 
+      @Override
       public Object get(final GeneratedMessage message) {
         return invokeOrDie(getMethod, message);
       }
+      @Override
       public Object get(GeneratedMessage.Builder builder) {
         return invokeOrDie(getMethodBuilder, builder);
       }
+      @Override
       public Object getRaw(final GeneratedMessage message) {
         return get(message);
       }
+      @Override
       public Object getRaw(GeneratedMessage.Builder builder) {
         return get(builder);
       }
+      @Override
       public void set(final Builder builder, final Object value) {
         // Add all the elements individually.  This serves two purposes:
         // 1) Verifies that each element has the correct type.
@@ -2271,54 +2296,64 @@ public abstract class GeneratedMessage extends AbstractMessage
           addRepeated(builder, element);
         }
       }
-      public Object getRepeated(final GeneratedMessage message,
-                                final int index) {
+      @Override
+      public Object getRepeated(final GeneratedMessage message, final int index) {
         return invokeOrDie(getRepeatedMethod, message, index);
       }
+      @Override
       public Object getRepeated(GeneratedMessage.Builder builder, int index) {
         return invokeOrDie(getRepeatedMethodBuilder, builder, index);
       }
+      @Override
       public Object getRepeatedRaw(GeneratedMessage message, int index) {
         return getRepeated(message, index);
       }
-      public Object getRepeatedRaw(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Object getRepeatedRaw(GeneratedMessage.Builder builder, int index) {
         return getRepeated(builder, index);
       }
-      public void setRepeated(final Builder builder,
-                              final int index, final Object value) {
+      @Override
+      public void setRepeated(final Builder builder, final int index, final Object value) {
         invokeOrDie(setRepeatedMethod, builder, index, value);
       }
+      @Override
       public void addRepeated(final Builder builder, final Object value) {
         invokeOrDie(addRepeatedMethod, builder, value);
       }
+      @Override
       public boolean has(final GeneratedMessage message) {
         throw new UnsupportedOperationException(
           "hasField() called on a repeated field.");
       }
+      @Override
       public boolean has(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "hasField() called on a repeated field.");
       }
+      @Override
       public int getRepeatedCount(final GeneratedMessage message) {
         return (Integer) invokeOrDie(getCountMethod, message);
       }
+      @Override
       public int getRepeatedCount(GeneratedMessage.Builder builder) {
         return (Integer) invokeOrDie(getCountMethodBuilder, builder);
       }
+      @Override
       public void clear(final Builder builder) {
         invokeOrDie(clearMethod, builder);
       }
+      @Override
       public Message.Builder newBuilder() {
         throw new UnsupportedOperationException(
           "newBuilderForField() called on a non-Message type.");
       }
+      @Override
       public Message.Builder getBuilder(GeneratedMessage.Builder builder) {
         throw new UnsupportedOperationException(
           "getFieldBuilder() called on a non-Message type.");
       }
-      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder,
-          int index) {
+      @Override
+      public Message.Builder getRepeatedBuilder(GeneratedMessage.Builder builder, int index) {
         throw new UnsupportedOperationException(
           "getRepeatedFieldBuilder() called on a non-Message type.");
       }
@@ -2355,6 +2390,7 @@ public abstract class GeneratedMessage extends AbstractMessage
             field.getNumber());
       }
 
+      @Override
       public Object get(GeneratedMessage message) {
         List result = new ArrayList();
         for (int i = 0; i < getRepeatedCount(message); i++) {
@@ -2363,6 +2399,7 @@ public abstract class GeneratedMessage extends AbstractMessage
         return Collections.unmodifiableList(result);
       }
 
+      @Override
       public Object get(Builder builder) {
         List result = new ArrayList();
         for (int i = 0; i < getRepeatedCount(builder); i++) {
@@ -2371,14 +2408,17 @@ public abstract class GeneratedMessage extends AbstractMessage
         return Collections.unmodifiableList(result);
       }
 
+      @Override
       public Object getRaw(GeneratedMessage message) {
         return get(message);
       }
 
+      @Override
       public Object getRaw(GeneratedMessage.Builder builder) {
         return get(builder);
       }
 
+      @Override
       public void set(Builder builder, Object value) {
         clear(builder);
         for (Object entry : (List) value) {
@@ -2386,63 +2426,76 @@ public abstract class GeneratedMessage extends AbstractMessage
         }
       }
 
+      @Override
       public Object getRepeated(GeneratedMessage message, int index) {
         return getMapField(message).getList().get(index);
       }
 
+      @Override
       public Object getRepeated(Builder builder, int index) {
         return getMapField(builder).getList().get(index);
       }
 
+      @Override
       public Object getRepeatedRaw(GeneratedMessage message, int index) {
         return getRepeated(message, index);
       }
 
+      @Override
       public Object getRepeatedRaw(Builder builder, int index) {
         return getRepeated(builder, index);
       }
 
+      @Override
       public void setRepeated(Builder builder, int index, Object value) {
         getMutableMapField(builder).getMutableList().set(index, (Message) value);
       }
 
+      @Override
       public void addRepeated(Builder builder, Object value) {
         getMutableMapField(builder).getMutableList().add((Message) value);
       }
 
+      @Override
       public boolean has(GeneratedMessage message) {
         throw new UnsupportedOperationException(
             "hasField() is not supported for repeated fields.");
       }
 
+      @Override
       public boolean has(Builder builder) {
         throw new UnsupportedOperationException(
             "hasField() is not supported for repeated fields.");
       }
 
+      @Override
       public int getRepeatedCount(GeneratedMessage message) {
         return getMapField(message).getList().size();
       }
 
+      @Override
       public int getRepeatedCount(Builder builder) {
         return getMapField(builder).getList().size();
       }
 
+      @Override
       public void clear(Builder builder) {
         getMutableMapField(builder).getMutableList().clear();
       }
 
+      @Override
       public com.google.protobuf.Message.Builder newBuilder() {
         return mapEntryMessageDefaultInstance.newBuilderForType();
       }
 
+      @Override
       public com.google.protobuf.Message.Builder getBuilder(Builder builder) {
         throw new UnsupportedOperationException(
             "Nested builder not supported for map fields.");
       }
 
-      public com.google.protobuf.Message.Builder getRepeatedBuilder(
-          Builder builder, int index) {
+      @Override
+      public com.google.protobuf.Message.Builder getRepeatedBuilder(Builder builder, int index) {
         throw new UnsupportedOperationException(
             "Nested builder not supported for map fields.");
       }

java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java

@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import com.google.protobuf.AbstractMessageLite.Builder.LimitedInputStream;
+import com.google.protobuf.GeneratedMessageLite.EqualsVisitor.NotEqualsException;
 import com.google.protobuf.Internal.BooleanList;
 import com.google.protobuf.Internal.DoubleList;
 import com.google.protobuf.Internal.FloatList;
@@ -39,6 +41,7 @@ import com.google.protobuf.Internal.ProtobufList;
 import com.google.protobuf.WireFormat.FieldType;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
@@ -57,32 +60,108 @@ import java.util.Map;
 public abstract class GeneratedMessageLite<
     MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
     BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>> 
-        extends AbstractMessageLite
-        implements Serializable {
-
-  private static final long serialVersionUID = 1L;
+        extends AbstractMessageLite<MessageType, BuilderType> {
 
   /** For use by generated code only. Lazily initialized to reduce allocations. */
-  protected UnknownFieldSetLite unknownFields = null;
+  protected UnknownFieldSetLite unknownFields = UnknownFieldSetLite.getDefaultInstance();
   
   /** For use by generated code only.  */
   protected int memoizedSerializedSize = -1;
   
+  @Override
   @SuppressWarnings("unchecked") // Guaranteed by runtime.
   public final Parser<MessageType> getParserForType() {
     return (Parser<MessageType>) dynamicMethod(MethodToInvoke.GET_PARSER);
   }
 
+  @Override
   @SuppressWarnings("unchecked") // Guaranteed by runtime.
   public final MessageType getDefaultInstanceForType() {
     return (MessageType) dynamicMethod(MethodToInvoke.GET_DEFAULT_INSTANCE);
   }
 
+  @Override
   @SuppressWarnings("unchecked") // Guaranteed by runtime.
   public final BuilderType newBuilderForType() {
     return (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
   }
 
+  /**
+   * A reflective toString function. This is primarily intended as a developer aid, while keeping
+   * binary size down. The first line of the {@code toString()} representation includes a commented
+   * version of {@code super.toString()} to act as an indicator that this should not be relied on
+   * for comparisons.
+   * <p>
+   * NOTE: This method relies on the field getter methods not being stripped or renamed by proguard.
+   * If they are, the fields will not be included in the returned string representation.
+   * <p>
+   * NOTE: This implementation is liable to change in the future, and should not be relied on in
+   * code.
+   */
+  @Override
+  public String toString() {
+    return MessageLiteToString.toString(this, super.toString());
+  }
+
+  @SuppressWarnings("unchecked") // Guaranteed by runtime
+  @Override
+  public int hashCode() {
+    if (memoizedHashCode == 0) {
+      HashCodeVisitor visitor = new HashCodeVisitor();
+      visit(visitor, (MessageType) this);
+      memoizedHashCode = visitor.hashCode;
+    }
+    return memoizedHashCode;
+  }
+  
+  @SuppressWarnings("unchecked") // Guaranteed by runtime
+  int hashCode(HashCodeVisitor visitor) {
+    if (memoizedHashCode == 0) {
+      int inProgressHashCode = visitor.hashCode;
+      visitor.hashCode = 0;
+      visit(visitor, (MessageType) this);
+      memoizedHashCode = visitor.hashCode;
+      visitor.hashCode = inProgressHashCode;
+    }
+    return memoizedHashCode;
+  }
+  
+  @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
+  @Override
+  public boolean equals(Object other) {
+    if (this == other) {
+      return true;
+    }
+    
+    if (!getDefaultInstanceForType().getClass().isInstance(other)) {
+      return false;
+    }
+    
+    try {
+      visit(EqualsVisitor.INSTANCE, (MessageType) other);
+    } catch (NotEqualsException e) {
+      return false;
+    }
+    return true;
+  }
+  
+  /**
+   * Same as {@link #equals(Object)} but throws {@code NotEqualsException}.
+   */
+  @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
+  boolean equals(EqualsVisitor visitor, MessageLite other) {
+    if (this == other) {
+      return true;
+    }
+    
+    if (!getDefaultInstanceForType().getClass().isInstance(other)) {
+      return false;
+    }
+
+    visit(visitor, (MessageType) other);
+    return true;
+  }
+  
   // The general strategy for unknown fields is to use an UnknownFieldSetLite that is treated as
   // mutable during the parsing constructor and immutable after. This allows us to avoid
   // any unnecessary intermediary allocations while reducing the generated code size.
@@ -91,7 +170,7 @@ public abstract class GeneratedMessageLite<
    * Lazily initializes unknown fields.
    */
   private final void ensureUnknownFieldsInitialized() {
-    if (unknownFields == null) {
+    if (unknownFields == UnknownFieldSetLite.getDefaultInstance()) {
       unknownFields = UnknownFieldSetLite.newInstance();
     }
   }
@@ -130,18 +209,18 @@ public abstract class GeneratedMessageLite<
   /**
    * Called by subclasses to complete parsing. For use by generated code only.
    */
-  protected void doneParsing() {
-    if (unknownFields == null) {
-      unknownFields = UnknownFieldSetLite.getDefaultInstance();
-    } else {
-      unknownFields.makeImmutable();
-    }
+  protected void makeImmutable() {
+    dynamicMethod(MethodToInvoke.MAKE_IMMUTABLE);
+
+    unknownFields.makeImmutable();
   }
 
+  @Override
   public final boolean isInitialized() {
     return dynamicMethod(MethodToInvoke.IS_INITIALIZED, Boolean.TRUE) != null;
   }
 
+  @Override
   public final BuilderType toBuilder() {
     BuilderType builder = (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
     builder.mergeFrom((MessageType) this);
@@ -155,11 +234,14 @@ public abstract class GeneratedMessageLite<
    * For use by generated code only.
    */
   public static enum MethodToInvoke {
+    // Rely on/modify instance state
     IS_INITIALIZED,
-    PARSE_PARTIAL_FROM,
-    MERGE_FROM,
+    VISIT,
+    MERGE_FROM_STREAM,
     MAKE_IMMUTABLE,
-    NEW_INSTANCE,
+
+    // Rely on static state
+    NEW_MUTABLE_INSTANCE,
     NEW_BUILDER,
     GET_DEFAULT_INSTANCE,
     GET_PARSER;
@@ -171,17 +253,18 @@ public abstract class GeneratedMessageLite<
    * builders in the runtime. This method bundles those operations to reduce the generated methods
    * count.
    * <ul>
-   * <li>{@code PARSE_PARTIAL_FROM} is parameterized with an {@link CodedInputStream} and
+   * <li>{@code MERGE_FROM_STREAM} is parameterized with an {@link CodedInputStream} and
    * {@link ExtensionRegistryLite}. It consumes the input stream, parsing the contents into the
    * returned protocol buffer. If parsing throws an {@link InvalidProtocolBufferException}, the
-   * implementation wraps it in a RuntimeException
-   * <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer
+   * implementation wraps it in a RuntimeException.
+   * <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer that has not yet been
+   * made immutable. See {@code MAKE_IMMUTABLE}.
    * <li>{@code IS_INITIALIZED} is parameterized with a {@code Boolean} detailing whether to
    * memoize. It returns {@code null} for false and the default instance for true. We optionally
    * memoize to support the Builder case, where memoization is not desired.
    * <li>{@code NEW_BUILDER} returns a {@code BuilderType} instance.
-   * <li>{@code MERGE_FROM} is parameterized with a {@code MessageType} and merges the fields from
-   * that instance into this instance.
+   * <li>{@code VISIT} is parameterized with a {@code Visitor} and a {@code MessageType} and
+   * recursively iterates through the fields side by side between this and the instance.
    * <li>{@code MAKE_IMMUTABLE} sets all internal fields to an immutable state.
    * </ul>
    * This method, plus the implementation of the Builder, enables the Builder class to be proguarded
@@ -205,6 +288,11 @@ public abstract class GeneratedMessageLite<
     return dynamicMethod(method, null, null);
   }
 
+  void visit(Visitor visitor, MessageType other) {
+    dynamicMethod(MethodToInvoke.VISIT, visitor, other);
+    unknownFields = visitor.visitUnknownFields(unknownFields, other.unknownFields);
+  }
+  
   /**
    * Merge some unknown fields into the {@link UnknownFieldSetLite} for this
    * message.
@@ -219,7 +307,7 @@ public abstract class GeneratedMessageLite<
   public abstract static class Builder<
       MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
       BuilderType extends Builder<MessageType, BuilderType>>
-          extends AbstractMessageLite.Builder<BuilderType> {
+          extends AbstractMessageLite.Builder<MessageType, BuilderType> {
 
     private final MessageType defaultInstance;
     protected MessageType instance;
@@ -227,7 +315,8 @@ public abstract class GeneratedMessageLite<
 
     protected Builder(MessageType defaultInstance) {
       this.defaultInstance = defaultInstance;
-      this.instance = (MessageType) defaultInstance.dynamicMethod(MethodToInvoke.NEW_INSTANCE);
+      this.instance =
+          (MessageType) defaultInstance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
       isBuilt = false;
     }
 
@@ -237,26 +326,27 @@ public abstract class GeneratedMessageLite<
      */
     protected void copyOnWrite() {
       if (isBuilt) {
-        MessageType newInstance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_INSTANCE);
-        newInstance.dynamicMethod(MethodToInvoke.MERGE_FROM, instance);
+        MessageType newInstance =
+            (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
+        newInstance.visit(MergeFromVisitor.INSTANCE, instance);
         instance = newInstance;
         isBuilt = false;
       }
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final boolean isInitialized() {
       return GeneratedMessageLite.isInitialized(instance, false /* shouldMemoize */);
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final BuilderType clear() {
       // No need to copy on write since we're dropping the instance anyways.
-      instance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_INSTANCE);
+      instance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
       return (BuilderType) this;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public BuilderType clone() {
       BuilderType builder =
           (BuilderType) getDefaultInstanceForType().newBuilderForType();
@@ -264,20 +354,19 @@ public abstract class GeneratedMessageLite<
       return builder;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public MessageType buildPartial() {
       if (isBuilt) {
         return instance;
       }
       
-      instance.dynamicMethod(MethodToInvoke.MAKE_IMMUTABLE);
-      instance.unknownFields.makeImmutable();
+      instance.makeImmutable();
       
       isBuilt = true;
       return instance;
     }
 
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final MessageType build() {
       MessageType result = buildPartial();
       if (!result.isInitialized()) {
@@ -286,33 +375,36 @@ public abstract class GeneratedMessageLite<
       return result;
     }
     
+    @Override
+    protected BuilderType internalMergeFrom(MessageType message) {
+      return mergeFrom(message);
+    }
+    
     /** All subclasses implement this. */
     public BuilderType mergeFrom(MessageType message) {
       copyOnWrite();
-      instance.dynamicMethod(MethodToInvoke.MERGE_FROM, message);
+      instance.visit(MergeFromVisitor.INSTANCE, message);
       return (BuilderType) this;
     }
     
+    @Override
     public MessageType getDefaultInstanceForType() {
       return defaultInstance;
     }
     
+    @Override
     public BuilderType mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-        throws java.io.IOException {
-      MessageType parsedMessage = null;
+        throws IOException {
+      copyOnWrite();
       try {
-        parsedMessage =
-            (MessageType) getDefaultInstanceForType().getParserForType().parsePartialFrom(
-                input, extensionRegistry);
-      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage = (MessageType) e.getUnfinishedMessage();
-        throw e;
-      } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
+        instance.dynamicMethod(MethodToInvoke.MERGE_FROM_STREAM, input, extensionRegistry);
+      } catch (RuntimeException e) {
+        if (e.getCause() instanceof IOException) {
+          throw (IOException) e.getCause();
         }
+        throw e;
       }
       return (BuilderType) this;
     }
@@ -368,6 +460,12 @@ public abstract class GeneratedMessageLite<
       }
       extensions.mergeFrom(((ExtendableMessage) other).extensions);
     }
+
+    @Override
+    final void visit(Visitor visitor, MessageType other) {
+      super.visit(visitor, other);
+      extensions = visitor.visitExtensions(extensions, other.extensions);
+    }
     
     /**
      * Parse an unknown field or an extension. For use by generated code only.
@@ -505,9 +603,8 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extension) {
       GeneratedExtension<MessageType, Type> extensionLite =
           checkIsLite(extension);
       
@@ -516,7 +613,7 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extension) {
       GeneratedExtension<MessageType, List<Type>> extensionLite =
@@ -527,10 +624,9 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extension) {
       GeneratedExtension<MessageType, Type> extensionLite =
           checkIsLite(extension);
       
@@ -544,11 +640,10 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get one element of a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extension,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extension, final int index) {
       GeneratedExtension<MessageType, List<Type>> extensionLite =
           checkIsLite(extension);
 
@@ -562,10 +657,9 @@ public abstract class GeneratedMessageLite<
       return extensions.isInitialized();
     }
 
-
     @Override
-    protected final void doneParsing() {
-      super.doneParsing();
+    protected final void makeImmutable() {
+      super.makeImmutable();
       
       extensions.makeImmutable();
     }
@@ -654,7 +748,7 @@ public abstract class GeneratedMessageLite<
       instance.extensions = extensions;
     }
 
-    // @Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     protected void copyOnWrite() {
       if (!isBuilt) {
         return;
@@ -664,7 +758,7 @@ public abstract class GeneratedMessageLite<
       instance.extensions = instance.extensions.clone();
     }
 
-    // @Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final MessageType buildPartial() {
       if (isBuilt) {
         return instance;
@@ -686,33 +780,30 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Check if a singular extension is present. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
-    public final <Type> boolean hasExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    @Override
+    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extension) {
       return instance.hasExtension(extension);
     }
 
     /** Get the number of elements in a repeated extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     public final <Type> int getExtensionCount(
         final ExtensionLite<MessageType, List<Type>> extension) {
       return instance.getExtensionCount(extension);
     }
 
     /** Get the value of an extension. */
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    @Override
     @SuppressWarnings("unchecked")
-    public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, Type> extension) {
+    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extension) {
       return instance.getExtension(extension);
     }
 
     /** Get one element of a repeated extension. */
+    @Override
     @SuppressWarnings("unchecked")
-    //@Override (Java 1.6 override semantics, but we must support 1.5)
     public final <Type> Type getExtension(
-        final ExtensionLite<MessageType, List<Type>> extension,
-        final int index) {
+        final ExtensionLite<MessageType, List<Type>> extension, final int index) {
       return instance.getExtension(extension, index);
     }
 
@@ -844,37 +935,44 @@ public abstract class GeneratedMessageLite<
     final boolean isRepeated;
     final boolean isPacked;
 
+    @Override
     public int getNumber() {
       return number;
     }
 
+    @Override
     public WireFormat.FieldType getLiteType() {
       return type;
     }
 
+    @Override
     public WireFormat.JavaType getLiteJavaType() {
       return type.getJavaType();
     }
 
+    @Override
     public boolean isRepeated() {
       return isRepeated;
     }
 
+    @Override
     public boolean isPacked() {
       return isPacked;
     }
 
+    @Override
     public Internal.EnumLiteMap<?> getEnumType() {
       return enumTypeMap;
     }
 
+    @Override
     @SuppressWarnings("unchecked")
-    public MessageLite.Builder internalMergeFrom(
-        MessageLite.Builder to, MessageLite from) {
+    public MessageLite.Builder internalMergeFrom(MessageLite.Builder to, MessageLite from) {
       return ((Builder) to).mergeFrom((GeneratedMessageLite) from);
     }
 
 
+    @Override
     public int compareTo(ExtensionDescriptor other) {
       return number - other.number;
     }
@@ -969,6 +1067,7 @@ public abstract class GeneratedMessageLite<
     }
 
     /** Get the field number. */
+    @Override
     public int getNumber() {
       return descriptor.getNumber();
     }
@@ -978,6 +1077,7 @@ public abstract class GeneratedMessageLite<
      * If the extension is an embedded message or group, returns the default
      * instance of the message.
      */
+    @Override
     public MessageLite getMessageDefaultInstance() {
       return messageDefaultInstance;
     }
@@ -1032,14 +1132,17 @@ public abstract class GeneratedMessageLite<
       }
     }
 
+    @Override
     public FieldType getLiteType() {
       return descriptor.getLiteType();
     }
 
+    @Override
     public boolean isRepeated() {
       return descriptor.isRepeated;
     }
 
+    @Override
     public Type getDefaultValue() {
       return defaultValue;
     }
@@ -1049,7 +1152,12 @@ public abstract class GeneratedMessageLite<
    * A serialized (serializable) form of the generated message.  Stores the
    * message as a class name and a byte array.
    */
-  static final class SerializedForm implements Serializable {
+  protected static final class SerializedForm implements Serializable {
+
+    public static SerializedForm of(MessageLite message) {
+      return new SerializedForm(message);
+    }
+    
     private static final long serialVersionUID = 0L;
 
     private final String messageClassName;
@@ -1093,16 +1201,6 @@ public abstract class GeneratedMessageLite<
       }
     }
   }
-
-  /**
-   * Replaces this object in the output stream with a serialized form.
-   * Part of Java's serialization magic.  Generated sub-classes must override
-   * this method by calling {@code return super.writeReplace();}
-   * @return a SerializedForm of this message
-   */
-  protected Object writeReplace() throws ObjectStreamException {
-    return new SerializedForm(this);
-  }
   
   /**
    * Checks that the {@link Extension} is Lite and returns it as a
@@ -1129,30 +1227,72 @@ public abstract class GeneratedMessageLite<
   protected static final <T extends GeneratedMessageLite<T, ?>> boolean isInitialized(
       T message, boolean shouldMemoize) {
     return message.dynamicMethod(MethodToInvoke.IS_INITIALIZED, shouldMemoize) != null;
-  }
+  } 
   
   protected static final <T extends GeneratedMessageLite<T, ?>> void makeImmutable(T message) {
     message.dynamicMethod(MethodToInvoke.MAKE_IMMUTABLE);
   }
+
+  protected static IntList emptyIntList() {
+    return IntArrayList.emptyList();
+  }
+
+  protected static IntList mutableCopy(IntList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static LongList emptyLongList() {
+    return LongArrayList.emptyList();
+  }
   
-  /**
-   * A static helper method for parsing a partial from input using the extension registry and the
-   * instance.
-   */
-  static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
-      T instance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
-          throws InvalidProtocolBufferException {
-    try {
-      return (T) instance.dynamicMethod(
-          MethodToInvoke.PARSE_PARTIAL_FROM, input, extensionRegistry);
-    } catch (RuntimeException e) {
-      if (e.getCause() instanceof InvalidProtocolBufferException) {
-        throw (InvalidProtocolBufferException) e.getCause();
-      }
-      throw e;
-    }
+  protected static LongList mutableCopy(LongList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static FloatList emptyFloatList() {
+    return FloatArrayList.emptyList();
+  }
+  
+  protected static FloatList mutableCopy(FloatList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static DoubleList emptyDoubleList() {
+    return DoubleArrayList.emptyList();
+  }
+  
+  protected static DoubleList mutableCopy(DoubleList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static BooleanList emptyBooleanList() {
+    return BooleanArrayList.emptyList();
+  }
+  
+  protected static BooleanList mutableCopy(BooleanList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static <E> ProtobufList<E> emptyProtobufList() {
+    return ProtobufArrayList.emptyList();
   }
   
+  protected static <E> ProtobufList<E> mutableCopy(ProtobufList<E> list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
   /**
    * A {@link Parser} implementation that delegates to the default instance.
    * <p>
@@ -1174,103 +1314,929 @@ public abstract class GeneratedMessageLite<
     }
   }
   
-  protected static IntList newIntList() {
-    return new IntArrayList();
-  }
-  
-  protected static IntList newIntListWithCapacity(int capacity) {
-    return new IntArrayList(capacity);
+  /**
+   * A static helper method for parsing a partial from input using the extension registry and the
+   * instance.
+   */
+  // TODO(dweis): Should this verify that the last tag was 0?
+  static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T instance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+          throws InvalidProtocolBufferException {
+    @SuppressWarnings("unchecked") // Guaranteed by protoc
+    T result = (T) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
+    try {
+      result.dynamicMethod(MethodToInvoke.MERGE_FROM_STREAM, input, extensionRegistry);
+      result.makeImmutable();
+    } catch (RuntimeException e) {
+      if (e.getCause() instanceof InvalidProtocolBufferException) {
+        throw (InvalidProtocolBufferException) e.getCause();
+      }
+      throw e;
+    }
+    return result;
   }
   
-  protected static IntList newIntList(List<Integer> toCopy) {
-    return new IntArrayList(toCopy);
+  protected static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T defaultInstance,
+      CodedInputStream input)
+      throws InvalidProtocolBufferException {
+    return parsePartialFrom(defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry());
   }
   
-  protected static IntList emptyIntList() {
-    return IntArrayList.emptyList();
+  /**
+   * Helper method to check if message is initialized.
+   *
+   * @throws InvalidProtocolBufferException if it is not initialized.
+   * @return The message to check.
+   */
+  private static <T extends GeneratedMessageLite<T, ?>> T checkMessageInitialized(T message)
+      throws InvalidProtocolBufferException {
+    if (message != null && !message.isInitialized()) {
+      throw message.newUninitializedMessageException()
+          .asInvalidProtocolBufferException()
+          .setUnfinishedMessage(message);
+    }
+    return message;
   }
 
-  protected static LongList newLongList() {
-    return new LongArrayList();
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, ByteString data)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parseFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry()));
   }
 
-  protected static LongList newLongListWithCapacity(int capacity) {
-    return new LongArrayList(capacity);
-  }
-  
-  protected static LongList newLongList(List<Long> toCopy) {
-    return new LongArrayList(toCopy);
-  }
-  
-  protected static LongList emptyLongList() {
-    return LongArrayList.emptyList();
-  }
-  
-  protected static FloatList newFloatList() {
-    return new FloatArrayList();
-  }
-  
-  protected static FloatList newFloatListWithCapacity(int capacity) {
-    return new FloatArrayList(capacity);
-  }
-  
-  protected static FloatList newFloatList(List<Float> toCopy) {
-    return new FloatArrayList(toCopy);
-  }
-  
-  protected static FloatList emptyFloatList() {
-    return FloatArrayList.emptyList();
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, ByteString data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(parsePartialFrom(defaultInstance, data, extensionRegistry));
   }
   
-  protected static DoubleList newDoubleList() {
-    return new DoubleArrayList();
+  // This is a special case since we want to verify that the last tag is 0. We assume we exhaust the
+  // ByteString.
+  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T defaultInstance, ByteString data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    T message;
+    try {
+      CodedInputStream input = data.newCodedInput();
+      message = parsePartialFrom(defaultInstance, input, extensionRegistry);
+      try {
+        input.checkLastTagWas(0);
+      } catch (InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(message);
+      }
+      return message;
+    } catch (InvalidProtocolBufferException e) {
+      throw e;
+    }
   }
   
-  protected static DoubleList newDoubleListWithCapacity(int capacity) {
-    return new DoubleArrayList(capacity);
+  // This is a special case since we want to verify that the last tag is 0. We assume we exhaust the
+  // ByteString.
+  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
+      T defaultInstance, byte[] data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    T message;
+    try {
+      CodedInputStream input = CodedInputStream.newInstance(data);
+      message = parsePartialFrom(defaultInstance, input, extensionRegistry);
+      try {
+        input.checkLastTagWas(0);
+      } catch (InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(message);
+      }
+      return message;
+    } catch (InvalidProtocolBufferException e) {
+      throw e;
+    }
   }
-  
-  protected static DoubleList newDoubleList(List<Double> toCopy) {
-    return new DoubleArrayList(toCopy);
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, byte[] data)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static DoubleList emptyDoubleList() {
-    return DoubleArrayList.emptyList();
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, byte[] data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(parsePartialFrom(defaultInstance, data, extensionRegistry));
   }
-  
-  protected static BooleanList newBooleanList() {
-    return new BooleanArrayList();
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, InputStream input)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, CodedInputStream.newInstance(input),
+            ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static BooleanList newBooleanListWithCapacity(int capacity) {
-    return new BooleanArrayList(capacity);
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, CodedInputStream.newInstance(input), extensionRegistry));
   }
-  
-  protected static BooleanList newBooleanList(List<Boolean> toCopy) {
-    return new BooleanArrayList(toCopy);
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, CodedInputStream input)
+      throws InvalidProtocolBufferException {
+    return parseFrom(defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry());
   }
-  
-  protected static BooleanList emptyBooleanList() {
-    return BooleanArrayList.emptyList();
+
+  // Does not validate last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialFrom(defaultInstance, input, extensionRegistry));
   }
-  
-  protected static <E> ProtobufList<E> newProtobufList() {
-    return new ProtobufArrayList<E>();
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseDelimitedFrom(
+      T defaultInstance, InputStream input)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialDelimitedFrom(defaultInstance, input,
+            ExtensionRegistryLite.getEmptyRegistry()));
   }
-  
-  protected static <E> ProtobufList<E> newProtobufList(List<E> toCopy) {
-    return new ProtobufArrayList<E>(toCopy);
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseDelimitedFrom(
+      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parsePartialDelimitedFrom(defaultInstance, input, extensionRegistry));
   }
   
-  protected static <E> ProtobufList<E> newProtobufListWithCapacity(int capacity) {
-    return new ProtobufArrayList<E>(capacity);
+  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialDelimitedFrom(
+      T defaultInstance,
+      InputStream input,
+      ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    int size;
+    try {
+      int firstByte = input.read();
+      if (firstByte == -1) {
+        return null;
+      }
+      size = CodedInputStream.readRawVarint32(firstByte, input);
+    } catch (IOException e) {
+      throw new InvalidProtocolBufferException(e.getMessage());
+    }
+    InputStream limitedInput = new LimitedInputStream(input, size);
+    CodedInputStream codedInput = CodedInputStream.newInstance(limitedInput);
+    T message = parsePartialFrom(defaultInstance, codedInput, extensionRegistry);
+    try {
+      codedInput.checkLastTagWas(0);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(message);
+    }
+    return message;
   }
-  
-  protected static <E> ProtobufList<E> emptyProtobufList() {
-    return ProtobufArrayList.emptyList();
+
+  /**
+   * An abstract visitor that the generated code calls into that we use to implement various
+   * features. Fields that are not members of oneofs are always visited. Members of a oneof are only
+   * visited when they are the set oneof case value on the "other" proto. The visitOneofNotSet
+   * method is invoked if other's oneof case is not set.
+   */
+  protected interface Visitor {
+    boolean visitBoolean(boolean minePresent, boolean mine, boolean otherPresent, boolean other);
+    int visitInt(boolean minePresent, int mine, boolean otherPresent, int other);
+    double visitDouble(boolean minePresent, double mine, boolean otherPresent, double other);
+    float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other);
+    long visitLong(boolean minePresent, long mine, boolean otherPresent, long other);
+    String visitString(boolean minePresent, String mine, boolean otherPresent, String other);
+    ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other);
+
+    Object visitOneofBoolean(boolean minePresent, Object mine, Object other);
+    Object visitOneofInt(boolean minePresent, Object mine, Object other);
+    Object visitOneofDouble(boolean minePresent, Object mine, Object other);
+    Object visitOneofFloat(boolean minePresent, Object mine, Object other);
+    Object visitOneofLong(boolean minePresent, Object mine, Object other);
+    Object visitOneofString(boolean minePresent, Object mine, Object other);
+    Object visitOneofByteString(boolean minePresent, Object mine, Object other);
+    Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other);
+    Object visitOneofMessage(boolean minePresent, Object mine, Object other);
+    void visitOneofNotSet(boolean minePresent);
+    
+    /**
+     * Message fields use null sentinals.
+     */
+    <T extends MessageLite> T visitMessage(T mine, T other);
+    LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other);
+
+    <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other);
+    BooleanList visitBooleanList(BooleanList mine, BooleanList other);
+    IntList visitIntList(IntList mine, IntList other);
+    DoubleList visitDoubleList(DoubleList mine, DoubleList other);
+    FloatList visitFloatList(FloatList mine, FloatList other);
+    LongList visitLongList(LongList mine, LongList other);
+    FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine, FieldSet<ExtensionDescriptor> other);
+    UnknownFieldSetLite visitUnknownFields(UnknownFieldSetLite mine, UnknownFieldSetLite other);
+    <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other);
   }
-  
-  protected static LazyStringArrayList emptyLazyStringArrayList() {
-    return LazyStringArrayList.emptyList();
+
+  /**
+   * Implements equals. Throws a {@link NotEqualsException} when not equal.
+   */
+  static class EqualsVisitor implements Visitor {
+
+    static final class NotEqualsException extends RuntimeException {}
+
+    static final EqualsVisitor INSTANCE = new EqualsVisitor();
+
+    static final NotEqualsException NOT_EQUALS = new NotEqualsException();
+
+    private EqualsVisitor() {}
+
+    @Override
+    public boolean visitBoolean(
+        boolean minePresent, boolean mine, boolean otherPresent, boolean other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public int visitInt(boolean minePresent, int mine, boolean otherPresent, int other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public double visitDouble(
+        boolean minePresent, double mine, boolean otherPresent, double other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public long visitLong(boolean minePresent, long mine, boolean otherPresent, long other) {
+      if (minePresent != otherPresent || mine != other) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public String visitString(
+        boolean minePresent, String mine, boolean otherPresent, String other) {
+      if (minePresent != otherPresent || !mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other) {
+      if (minePresent != otherPresent || !mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofBoolean(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofInt(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofDouble(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofFloat(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofLong(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofString(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofByteString(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+    
+    @Override
+    public Object visitOneofMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent && ((GeneratedMessageLite<?, ?>) mine).equals(this, (MessageLite) other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+    
+    @Override
+    public void visitOneofNotSet(boolean minePresent) {
+      if (minePresent) {
+        throw NOT_EQUALS;
+      }
+    }
+
+    @Override
+    public <T extends MessageLite> T visitMessage(T mine, T other) {
+      if (mine == null && other == null) {
+        return null;
+      }
+
+      if (mine == null || other == null) {
+        throw NOT_EQUALS;
+      }
+
+      ((GeneratedMessageLite<?, ?>) mine).equals(this, other);
+
+      return mine;
+    }
+    
+    @Override
+    public LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other) {
+      if (!minePresent && !otherPresent) {
+        return mine;
+      } else if (minePresent && otherPresent && mine.equals(other)) {
+        return mine;
+      }
+      throw NOT_EQUALS;
+    }
+
+    @Override
+    public <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public BooleanList visitBooleanList(BooleanList mine, BooleanList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public IntList visitIntList(IntList mine, IntList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public DoubleList visitDoubleList(DoubleList mine, DoubleList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public FloatList visitFloatList(FloatList mine, FloatList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public LongList visitLongList(LongList mine, LongList other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine,
+        FieldSet<ExtensionDescriptor> other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public UnknownFieldSetLite visitUnknownFields(
+        UnknownFieldSetLite mine,
+        UnknownFieldSetLite other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+
+    @Override
+    public <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other) {
+      if (!mine.equals(other)) {
+        throw NOT_EQUALS;
+      }
+      return mine;
+    }
+  }
+
+  /**
+   * Implements hashCode by accumulating state.
+   */
+  private static class HashCodeVisitor implements Visitor {
+
+    // The caller must ensure that the visitor is invoked parameterized with this and this such that
+    // other is this. This is required due to how oneof cases are handled. See the class comment
+    // on Visitor for more information.
+    
+    private int hashCode = 0;
+
+    @Override
+    public boolean visitBoolean(
+        boolean minePresent, boolean mine, boolean otherPresent, boolean other) {
+      hashCode = (53 * hashCode) + Internal.hashBoolean(mine);
+      return mine;
+    }
+
+    @Override
+    public int visitInt(boolean minePresent, int mine, boolean otherPresent, int other) {
+      hashCode = (53 * hashCode) + mine;
+      return mine;
+    }
+
+    @Override
+    public double visitDouble(
+        boolean minePresent, double mine, boolean otherPresent, double other) {
+      hashCode = (53 * hashCode) + Internal.hashLong(Double.doubleToLongBits(mine));
+      return mine;
+    }
+
+    @Override
+    public float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other) {
+      hashCode = (53 * hashCode) + Float.floatToIntBits(mine);
+      return mine;
+    }
+
+    @Override
+    public long visitLong(boolean minePresent, long mine, boolean otherPresent, long other) {
+      hashCode = (53 * hashCode) + Internal.hashLong(mine);
+      return mine;
+    }
+
+    @Override
+    public String visitString(
+        boolean minePresent, String mine, boolean otherPresent, String other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofBoolean(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Internal.hashBoolean(((Boolean) mine));
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofInt(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + (Integer) mine;
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofDouble(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Internal.hashLong(Double.doubleToLongBits((Double) mine));
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofFloat(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Float.floatToIntBits((Float) mine);
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofLong(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + Internal.hashLong((Long) mine);
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofString(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofByteString(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+    
+    @Override
+    public Object visitOneofMessage(boolean minePresent, Object mine, Object other) {
+      return visitMessage((MessageLite) mine, (MessageLite) other);
+    }
+
+    @Override
+    public void visitOneofNotSet(boolean minePresent) {
+      if (minePresent) {
+        throw new IllegalStateException(); // Can't happen if other == this. 
+      }
+    }
+
+    @Override
+    public <T extends MessageLite> T visitMessage(T mine, T other) {
+      final int protoHash;
+      if (mine != null) {
+        if (mine instanceof GeneratedMessageLite) {
+          protoHash = ((GeneratedMessageLite) mine).hashCode(this);
+        } else {
+          protoHash = mine.hashCode();
+        }
+      } else {
+        protoHash = 37;
+      }
+      hashCode = (53 * hashCode) + protoHash;
+      return mine;
+    }
+
+    @Override
+    public LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public BooleanList visitBooleanList(BooleanList mine, BooleanList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public IntList visitIntList(IntList mine, IntList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public DoubleList visitDoubleList(DoubleList mine, DoubleList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public FloatList visitFloatList(FloatList mine, FloatList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public LongList visitLongList(LongList mine, LongList other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine,
+        FieldSet<ExtensionDescriptor> other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+
+    @Override
+    public UnknownFieldSetLite visitUnknownFields(
+        UnknownFieldSetLite mine,
+        UnknownFieldSetLite other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+    
+    @Override
+    public <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other) {
+      hashCode = (53 * hashCode) + mine.hashCode();
+      return mine;
+    }
+  }
+
+  /**
+   * Implements field merging semantics over the visitor interface.
+   */
+  protected static class MergeFromVisitor implements Visitor {
+
+    public static final MergeFromVisitor INSTANCE = new MergeFromVisitor();
+
+    private MergeFromVisitor() {}
+
+    @Override
+    public boolean visitBoolean(
+        boolean minePresent, boolean mine, boolean otherPresent, boolean other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public int visitInt(boolean minePresent, int mine, boolean otherPresent, int other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public double visitDouble(
+        boolean minePresent, double mine, boolean otherPresent, double other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public float visitFloat(boolean minePresent, float mine, boolean otherPresent, float other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public long visitLong(boolean minePresent, long mine, boolean otherPresent, long other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public String visitString(
+        boolean minePresent, String mine, boolean otherPresent, String other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public ByteString visitByteString(
+        boolean minePresent, ByteString mine, boolean otherPresent, ByteString other) {
+      return otherPresent ? other : mine;
+    }
+
+    @Override
+    public Object visitOneofBoolean(boolean minePresent, Object mine, Object other) {
+      return other;
+    }
+
+    @Override
+    public Object visitOneofInt(boolean minePresent, Object mine, Object other) {
+      return other;
+    }
+
+    @Override
+    public Object visitOneofDouble(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofFloat(boolean minePresent, Object mine, Object other) {
+      return other;
+    }
+
+    @Override
+    public Object visitOneofLong(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofString(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofByteString(boolean minePresent, Object mine, Object other) {
+      return other;      
+    }
+
+    @Override
+    public Object visitOneofLazyMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent) {
+        LazyFieldLite lazy = (LazyFieldLite) mine;
+        lazy.merge((LazyFieldLite) other);
+        return lazy;
+      }
+      return other;
+    }
+    
+    @Override
+    public Object visitOneofMessage(boolean minePresent, Object mine, Object other) {
+      if (minePresent) {
+        return visitMessage((MessageLite) mine, (MessageLite) other);
+      }
+      return other;
+    }
+    
+    @Override
+    public void visitOneofNotSet(boolean minePresent) {
+      return;
+    }
+
+    @SuppressWarnings("unchecked") // Guaranteed by runtime.
+    @Override
+    public <T extends MessageLite> T visitMessage(T mine, T other) {
+      if (mine != null && other != null) {
+        return (T) mine.toBuilder().mergeFrom(other).build();
+      }
+
+      return mine != null ? mine : other;
+    }
+
+    @Override
+    public LazyFieldLite visitLazyMessage(
+        boolean minePresent, LazyFieldLite mine, boolean otherPresent, LazyFieldLite other) {
+      // LazyFieldLite's are never null so we can just copy across. Necessary to avoid leakage
+      // from builder into immutable message.
+      // TODO(dweis): Change to null sentinels?
+      mine.merge(other);
+      return mine;
+    }
+
+    @Override
+    public <T> ProtobufList<T> visitList(ProtobufList<T> mine, ProtobufList<T> other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public BooleanList visitBooleanList(BooleanList mine, BooleanList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public IntList visitIntList(IntList mine, IntList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public DoubleList visitDoubleList(DoubleList mine, DoubleList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public FloatList visitFloatList(FloatList mine, FloatList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public LongList visitLongList(LongList mine, LongList other) {
+      int size = mine.size();
+      int otherSize = other.size();
+      if (size > 0 && otherSize > 0) {
+        if (!mine.isModifiable()) {
+          mine = mine.mutableCopyWithCapacity(size + otherSize);
+        }
+        mine.addAll(other);
+      }
+      
+      return size > 0 ? mine : other;
+    }
+
+    @Override
+    public FieldSet<ExtensionDescriptor> visitExtensions(
+        FieldSet<ExtensionDescriptor> mine,
+        FieldSet<ExtensionDescriptor> other) {
+      if (mine.isImmutable()) {
+        mine = mine.clone();
+      }
+      mine.mergeFrom(other);
+      return mine;
+    }
+
+    @Override
+    public UnknownFieldSetLite visitUnknownFields(
+        UnknownFieldSetLite mine,
+        UnknownFieldSetLite other) {
+      return other == UnknownFieldSetLite.getDefaultInstance()
+          ? mine : UnknownFieldSetLite.mutableCopyOf(mine, other);
+    }
+    
+    @Override
+    public <K, V> MapFieldLite<K, V> visitMap(MapFieldLite<K, V> mine, MapFieldLite<K, V> other) {
+      mine.mergeFrom(other);
+      return mine;
+    }
   }
 }

java/core/src/main/java/com/google/protobuf/IntArrayList.java

@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.IntList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -44,8 +43,6 @@ import java.util.RandomAccess;
  */
 final class IntArrayList extends AbstractProtobufList<Integer> implements IntList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final IntArrayList EMPTY_LIST = new IntArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -70,32 +67,55 @@ final class IntArrayList extends AbstractProtobufList<Integer> implements IntLis
    * Constructs a new mutable {@code IntArrayList} with default capacity.
    */
   IntArrayList() {
-    this(DEFAULT_CAPACITY);
-  }
-
-  /**
-   * Constructs a new mutable {@code IntArrayList} with the provided capacity.
-   */
-  IntArrayList(int capacity) {
-    array = new int[capacity];
-    size = 0;
+    this(new int[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code IntArrayList} containing the same elements as {@code other}.
    */
-  IntArrayList(List<Integer> other) {
-    if (other instanceof IntArrayList) {
-      IntArrayList list = (IntArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new int[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private IntArrayList(int[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof IntArrayList)) {
+      return super.equals(o);
+    }
+    IntArrayList other = (IntArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final int[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + array[i];
+    }
+    return result;
+  }
+
+  @Override
+  public IntList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new IntArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override

java/core/src/main/java/com/google/protobuf/Internal.java

@@ -41,6 +41,7 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.RandomAccess;
 import java.util.Set;
 
 /**
@@ -51,10 +52,12 @@ import java.util.Set;
  *
  * @author kenton@google.com (Kenton Varda)
  */
-public class Internal {
+public final class Internal {
 
-  protected static final Charset UTF_8 = Charset.forName("UTF-8");
-  protected static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
+  private Internal() {}
+
+  static final Charset UTF_8 = Charset.forName("UTF-8");
+  static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
 
   /**
    * Helper called by generated code to construct default values for string
@@ -406,6 +409,7 @@ public class Internal {
   public static final CodedInputStream EMPTY_CODED_INPUT_STREAM =
       CodedInputStream.newInstance(EMPTY_BYTE_ARRAY);
 
+
   /**
    * Provides an immutable view of {@code List<T>} around a {@code List<F>}.
    *
@@ -454,10 +458,13 @@ public class Internal {
     public static <T extends EnumLite> Converter<Integer, T> newEnumConverter(
         final EnumLiteMap<T> enumMap, final T unrecognizedValue) {
       return new Converter<Integer, T>() {
+        @Override
         public T doForward(Integer value) {
           T result = enumMap.findValueByNumber(value);
           return result == null ? unrecognizedValue : result;
         }
+
+        @Override
         public Integer doBackward(T value) {
           return value.getNumber();
         }
@@ -570,8 +577,10 @@ public class Internal {
   /**
    * Extends {@link List} to add the capability to make the list immutable and inspect if it is
    * modifiable.
+   * <p>
+   * All implementations must support efficient random access.
    */
-  public static interface ProtobufList<E> extends List<E> {
+  public static interface ProtobufList<E> extends List<E>, RandomAccess {
 
     /**
      * Makes this list immutable. All subsequent modifications will throw an
@@ -583,6 +592,11 @@ public class Internal {
      * Returns whether this list can be modified via the publicly accessible {@link List} methods.
      */
     boolean isModifiable();
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    ProtobufList<E> mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -597,14 +611,20 @@ public class Internal {
     int getInt(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Integer)} but more efficient in that it doesn't box the element.
      */
     void addInt(int element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Integer)} but more efficient in that it doesn't box the element.
      */
     int setInt(int index, int element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    IntList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -619,14 +639,20 @@ public class Internal {
     boolean getBoolean(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Boolean)} but more efficient in that it doesn't box the element.
      */
     void addBoolean(boolean element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Boolean)} but more efficient in that it doesn't box the element.
      */
     boolean setBoolean(int index, boolean element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    BooleanList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -641,14 +667,20 @@ public class Internal {
     long getLong(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Long)} but more efficient in that it doesn't box the element.
      */
     void addLong(long element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Long)} but more efficient in that it doesn't box the element.
      */
     long setLong(int index, long element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    LongList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -663,14 +695,20 @@ public class Internal {
     double getDouble(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Double)} but more efficient in that it doesn't box the element.
      */
     void addDouble(double element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Double)} but more efficient in that it doesn't box the element.
      */
     double setDouble(int index, double element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    DoubleList mutableCopyWithCapacity(int capacity);
   }
 
   /**
@@ -685,13 +723,19 @@ public class Internal {
     float getFloat(int index);
 
     /**
-     * Like {@link #add(Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #add(Float)} but more efficient in that it doesn't box the element.
      */
     void addFloat(float element);
 
     /**
-     * Like {@link #set(int, Object)} but more efficient in that it doesn't box the element.
+     * Like {@link #set(int, Float)} but more efficient in that it doesn't box the element.
      */
     float setFloat(int index, float element);
+
+    /**
+     * Returns a mutable clone of this list with the specified capacity.
+     */
+    @Override
+    FloatList mutableCopyWithCapacity(int capacity);
   }
 }

java/core/src/main/java/com/google/protobuf/LazyField.java

@@ -39,14 +39,14 @@ import java.util.Map.Entry;
  *
  * Most of key methods are implemented in {@link LazyFieldLite} but this class
  * can contain default instance of the message to provide {@code hashCode()},
- * {@code equals()} and {@code toString()}.
+ * {@code euqals()} and {@code toString()}.
  *
  * @author xiangl@google.com (Xiang Li)
  */
 public class LazyField extends LazyFieldLite {
 
   /**
-   * Carry a message's default instance which is used by {@code hashCode()}, {@code equals()} and
+   * Carry a message's default instance which is used by {@code hashCode()}, {@code euqals()} and
    * {@code toString()}.
    */
   private final MessageLite defaultInstance;
@@ -95,12 +95,12 @@ public class LazyField extends LazyFieldLite {
       this.entry = entry;
     }
 
-    // @Override
+    @Override
     public K getKey() {
       return entry.getKey();
     }
 
-    // @Override
+    @Override
     public Object getValue() {
       LazyField field = entry.getValue();
       if (field == null) {
@@ -113,7 +113,7 @@ public class LazyField extends LazyFieldLite {
       return entry.getValue();
     }
 
-    // @Override
+    @Override
     public Object setValue(Object value) {
       if (!(value instanceof MessageLite)) {
         throw new IllegalArgumentException(
@@ -131,13 +131,13 @@ public class LazyField extends LazyFieldLite {
       this.iterator = iterator;
     }
 
-    // @Override
+    @Override
     public boolean hasNext() {
       return iterator.hasNext();
     }
 
+    @Override
     @SuppressWarnings("unchecked")
-    // @Override
     public Entry<K, Object> next() {
       Entry<K, ?> entry = iterator.next();
       if (entry.getValue() instanceof LazyField) {
@@ -146,7 +146,7 @@ public class LazyField extends LazyFieldLite {
       return (Entry<K, Object>) entry;
     }
 
-    // @Override
+    @Override
     public void remove() {
       iterator.remove();
     }

java/core/src/main/java/com/google/protobuf/LazyFieldLite.java

@@ -30,14 +30,26 @@
 
 package com.google.protobuf;
 
+import java.io.IOException;
+
 /**
  * LazyFieldLite encapsulates the logic of lazily parsing message fields. It stores
- * the message in a ByteString initially and then parse it on-demand.
+ * the message in a ByteString initially and then parses it on-demand.
+ *
+ * LazyFieldLite is thread-compatible: concurrent reads are safe once the proto that this
+ * LazyFieldLite is a part of is no longer being mutated by its Builder. However, explicit
+ * synchronization is needed under read/write situations.
  *
- * LazyField is thread-compatible e.g. concurrent read are safe, however,
- * synchronizations are needed under read/write situations.
+ * When a LazyFieldLite is used in the context of a MessageLite object, its behavior is considered
+ * to be immutable and none of the setter methods in its API are expected to be invoked. All of the
+ * getters are expected to be thread-safe. When used in the context of a MessageLite.Builder,
+ * setters can be invoked, but there is no guarantee of thread safety.
+ * 
+ * TODO(yatin,dweis): Consider splitting this class's functionality and put the mutable methods
+ * into a separate builder class to allow us to give stronger compile-time guarantees.
  *
- * This class is internal implementation detail, so you don't need to use it directly.
+ * This class is internal implementation detail of the protobuf library, so you don't need to use it
+ * directly.
  *
  * @author xiangl@google.com (Xiang Li)
  */
@@ -46,8 +58,34 @@ public class LazyFieldLite {
       ExtensionRegistryLite.getEmptyRegistry();
 
   /**
-   * A delayed-parsed version of the bytes. When this is non-null then {@code extensionRegistry } is
-   * also non-null and {@code value} and {@code memoizedBytes} are null.
+   * The value associated with the LazyFieldLite object is stored in one or more of the following
+   * three fields (delayedBytes, value, memoizedBytes). They should together be interpreted as
+   * follows.
+   * 1) delayedBytes can be non-null, while value and memoizedBytes is null. The object will be in
+   *    this state while the value for the object has not yet been parsed.
+   * 2) Both delayedBytes and value are non-null. The object transitions to this state as soon as
+   *    some caller needs to access the value (by invoking getValue()).
+   * 3) memoizedBytes is merely an optimization for calls to LazyFieldLite.toByteString() to avoid
+   *    recomputing the ByteString representation on each call. Instead, when the value is parsed
+   *    from delayedBytes, we will also assign the contents of delayedBytes to memoizedBytes (since
+   *    that is the ByteString representation of value).
+   * 4) Finally, if the LazyFieldLite was created directly with a parsed MessageLite value, then
+   *    delayedBytes will be null, and memoizedBytes will be initialized only upon the first call to
+   *    LazyFieldLite.toByteString().
+   *
+   * Given the above conditions, any caller that needs a serialized representation of this object
+   * must first check if the memoizedBytes or delayedBytes ByteString is non-null and use it
+   * directly; if both of those are null, it can look at the parsed value field. Similarly, any
+   * caller that needs a parsed value must first check if the value field is already non-null, if
+   * not it must parse the value from delayedBytes.
+   */
+
+  /**
+   * A delayed-parsed version of the contents of this field. When this field is non-null, then the
+   * "value" field is allowed to be null until the time that the value needs to be read.
+   *
+   * When delayedBytes is non-null then {@code extensionRegistry} is required to also be non-null.
+   * {@code value} and {@code memoizedBytes} will be initialized lazily.
    */
   private ByteString delayedBytes;
 
@@ -60,12 +98,15 @@ public class LazyFieldLite {
   private ExtensionRegistryLite extensionRegistry;
 
   /**
-   * The parsed value. When this is non-null then {@code delayedBytes} will be null.
+   * The parsed value. When this is null and a caller needs access to the MessageLite value, then
+   * {@code delayedBytes} will be parsed lazily at that time.
    */
   protected volatile MessageLite value;
 
   /**
-   * The memoized bytes for {@code value}. Will be null when {@code value} is null.
+   * The memoized bytes for {@code value}. This is an optimization for the toByteString() method to
+   * not have to recompute its return-value on each invocation.
+   * TODO(yatin): Figure out whether this optimization is actually necessary.
    */
   private volatile ByteString memoizedBytes;
 
@@ -94,6 +135,43 @@ public class LazyFieldLite {
     return lf;
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    
+    if (!(o instanceof LazyFieldLite)) {
+      return false;
+    }
+
+    LazyFieldLite other = (LazyFieldLite) o;
+    
+    // Lazy fields do not work well with equals... If both are delayedBytes, we do not have a
+    // mechanism to deserialize them so we rely on bytes equality. Otherwise we coerce into an
+    // actual message (if necessary) and call equals on the message itself. This implies that two
+    // messages can by unequal but then be turned equal simply be invoking a getter on a lazy field.
+    MessageLite value1 = value;
+    MessageLite value2 = other.value;
+    if (value1 == null && value2 == null) {
+      return toByteString().equals(other.toByteString());
+    } else if (value1 != null && value2 != null) {
+      return value1.equals(value2);
+    } else if (value1 != null) {
+      return value1.equals(other.getValue(value1.getDefaultInstanceForType()));
+    } else {
+      return getValue(value2.getDefaultInstanceForType()).equals(value2);
+    }
+  }
+  
+  @Override
+  public int hashCode() {
+    // We can't provide a memoizable hash code for lazy fields. The byte strings may have different
+    // hash codes but evaluate to equivalent messages. And we have no facility for constructing
+    // a message here if we were not already holding a value.
+    return 1;
+  }
+  
   /**
    * Determines whether this LazyFieldLite instance represents the default instance of this type.
    */
@@ -230,6 +308,46 @@ public class LazyFieldLite {
       return;
     }
   }
+  
+  /**
+   * Merges another instance's contents from a stream.
+   *
+   * <p>LazyField is not thread-safe for write access. Synchronizations are needed
+   * under read/write situations.
+   */
+  public void mergeFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+      throws IOException {
+    if (this.containsDefaultInstance()) {
+      setByteString(input.readBytes(), extensionRegistry);
+      return;
+    }
+
+    // If the other field has an extension registry but this does not, copy over the other extension
+    // registry.
+    if (this.extensionRegistry == null) {
+      this.extensionRegistry = extensionRegistry;
+    }
+
+    // In the case that both of them are not parsed we simply concatenate the bytes to save time. In
+    // the (probably rare) case that they have different extension registries there is a chance that
+    // some of the extensions may be dropped, but the tradeoff of making this operation fast seems
+    // to outway the benefits of combining the extension registries, which is not normally done for
+    // lite protos anyways.
+    if (this.delayedBytes != null) {
+      setByteString(this.delayedBytes.concat(input.readBytes()), this.extensionRegistry);
+      return;
+    }
+
+    // We are parsed and both contain data. We won't drop any extensions here directly, but in the
+    // case that the extension registries are not the same then we might in the future if we
+    // need to serialize and parse a message again.
+    try {
+      setValue(value.toBuilder().mergeFrom(input, extensionRegistry).build());
+    } catch (InvalidProtocolBufferException e) {
+      // Nothing is logged and no exceptions are thrown. Clients will be unaware that a proto
+      // was invalid.
+    }
+  }
 
   private static MessageLite mergeValueAndBytes(
       MessageLite value, ByteString otherBytes, ExtensionRegistryLite extensionRegistry) {
@@ -259,10 +377,12 @@ public class LazyFieldLite {
    * parsed. Be careful when using this method.
    */
   public int getSerializedSize() {
-    if (delayedBytes != null) {
-      return delayedBytes.size();
-    } else if (memoizedBytes != null) {
+    // We *must* return delayed bytes size if it was ever set because the dependent messages may
+    // have memoized serialized size based off of it.
+    if (memoizedBytes != null) {
       return memoizedBytes.size();
+    } else if (delayedBytes != null) {
+      return delayedBytes.size();
     } else if (value != null) {
       return value.getSerializedSize();
     } else {
@@ -274,12 +394,14 @@ public class LazyFieldLite {
    * Returns a BytesString for this field in a thread-safe way.
    */
   public ByteString toByteString() {
-    if (delayedBytes != null) {
-      return delayedBytes;
-    }
     if (memoizedBytes != null) {
       return memoizedBytes;
     }
+    // We *must* return delayed bytes if it was set because the dependent messages may have
+    // memoized serialized size based off of it.
+    if (delayedBytes != null) {
+      return delayedBytes;
+    }
     synchronized (this) {
       if (memoizedBytes != null) {
         return memoizedBytes;
@@ -311,18 +433,15 @@ public class LazyFieldLite {
               .parseFrom(delayedBytes, extensionRegistry);
           this.value = parsedValue;
           this.memoizedBytes = delayedBytes;
-          this.delayedBytes = null;
         } else {
           this.value = defaultInstance;
           this.memoizedBytes = ByteString.EMPTY;
-          this.delayedBytes = null;
         }
       } catch (InvalidProtocolBufferException e) {
         // Nothing is logged and no exceptions are thrown. Clients will be unaware that this proto
         // was invalid.
         this.value = defaultInstance;
         this.memoizedBytes = ByteString.EMPTY;
-        this.delayedBytes = null;
       }
     }
   }

java/core/src/main/java/com/google/protobuf/LazyStringArrayList.java

@@ -30,12 +30,12 @@
 
 package com.google.protobuf;
 
-import java.util.Arrays;
-import java.util.List;
 import java.util.AbstractList;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -64,7 +64,7 @@ import java.util.RandomAccess;
  */
 public class LazyStringArrayList extends AbstractProtobufList<String>
     implements LazyStringList, RandomAccess {
-  
+
   private static final LazyStringArrayList EMPTY_LIST = new LazyStringArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -80,11 +80,11 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
   private final List<Object> list;
 
   public LazyStringArrayList() {
-    list = new ArrayList<Object>();
+    this(DEFAULT_CAPACITY);
   }
 
   public LazyStringArrayList(int intialCapacity) {
-    list = new ArrayList<Object>(intialCapacity);
+    this(new ArrayList<Object>(intialCapacity));
   }
 
   public LazyStringArrayList(LazyStringList from) {
@@ -93,7 +93,21 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
   }
 
   public LazyStringArrayList(List<String> from) {
-    list = new ArrayList<Object>(from);
+    this(new ArrayList<Object>(from));
+  }
+  
+  private LazyStringArrayList(ArrayList<Object> list) {
+    this.list = list;
+  }
+
+  @Override
+  public LazyStringArrayList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size()) {
+      throw new IllegalArgumentException();
+    }
+    ArrayList<Object> newList = new ArrayList<Object>(capacity);
+    newList.addAll(list);
+    return new LazyStringArrayList(newList);
   }
 
   @Override
@@ -170,7 +184,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return ret;
   }
 
-  // @Override
+  @Override
   public boolean addAllByteString(Collection<? extends ByteString> values) {
     ensureIsMutable();
     boolean ret = list.addAll(values);
@@ -178,7 +192,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return ret;
   }
 
-  // @Override
+  @Override
   public boolean addAllByteArray(Collection<byte[]> c) {
     ensureIsMutable();
     boolean ret = list.addAll(c);
@@ -201,14 +215,14 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     modCount++;
   }
 
-  // @Override
+  @Override
   public void add(ByteString element) {
     ensureIsMutable();
     list.add(element);
     modCount++;
   }
   
-  // @Override
+  @Override
   public void add(byte[] element) {
     ensureIsMutable();
     list.add(element);
@@ -220,7 +234,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return list.get(index);
   }
   
-  // @Override
+  @Override
   public ByteString getByteString(int index) {
     Object o = list.get(index);
     ByteString b = asByteString(o);
@@ -230,7 +244,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return b;
   }
   
-  // @Override
+  @Override
   public byte[] getByteArray(int index) {
     Object o = list.get(index);
     byte[] b = asByteArray(o);
@@ -240,7 +254,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return b;
   }
 
-  // @Override
+  @Override
   public void set(int index, ByteString s) {
     setAndReturn(index, s);
   }
@@ -250,7 +264,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     return list.set(index, s);
   }
 
-  // @Override
+  @Override
   public void set(int index, byte[] s) {
     setAndReturn(index, s);
   }
@@ -290,12 +304,12 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     }
   }
 
-  // @Override
+  @Override
   public List<?> getUnderlyingElements() {
     return Collections.unmodifiableList(list);
   }
 
-  // @Override
+  @Override
   public void mergeFrom(LazyStringList other) {
     ensureIsMutable();
     for (Object o : other.getUnderlyingElements()) {
@@ -349,7 +363,7 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     }
   }
   
-  // @Override
+  @Override
   public List<byte[]> asByteArrayList() {
     return new ByteArrayListView(this);
   }
@@ -393,12 +407,12 @@ public class LazyStringArrayList extends AbstractProtobufList<String>
     }
   }
 
-  // @Override
+  @Override
   public List<ByteString> asByteStringList() {
     return new ByteStringListView(this);
   }
 
-  // @Override
+  @Override
   public LazyStringList getUnmodifiableView() {
     if (isModifiable()) {
       return new UnmodifiableLazyStringList(this);

java/core/src/main/java/com/google/protobuf/LongArrayList.java

@@ -34,7 +34,6 @@ import com.google.protobuf.Internal.LongList;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.List;
 import java.util.RandomAccess;
 
 /**
@@ -44,8 +43,6 @@ import java.util.RandomAccess;
  */
 final class LongArrayList extends AbstractProtobufList<Long> implements LongList, RandomAccess {
   
-  private static final int DEFAULT_CAPACITY = 10;
-  
   private static final LongArrayList EMPTY_LIST = new LongArrayList();
   static {
     EMPTY_LIST.makeImmutable();
@@ -70,32 +67,55 @@ final class LongArrayList extends AbstractProtobufList<Long> implements LongList
    * Constructs a new mutable {@code LongArrayList} with default capacity.
    */
   LongArrayList() {
-    this(DEFAULT_CAPACITY);
-  }
-
-  /**
-   * Constructs a new mutable {@code LongArrayList} with the provided capacity.
-   */
-  LongArrayList(int capacity) {
-    array = new long[capacity];
-    size = 0;
+    this(new long[DEFAULT_CAPACITY], 0);
   }
 
   /**
    * Constructs a new mutable {@code LongArrayList} containing the same elements as {@code other}.
    */
-  LongArrayList(List<Long> other) {
-    if (other instanceof LongArrayList) {
-      LongArrayList list = (LongArrayList) other;
-      array = list.array.clone();
-      size = list.size;
-    } else {
-      size = other.size();
-      array = new long[size];
-      for (int i = 0; i < size; i++) {
-        array[i] = other.get(i);
+  private LongArrayList(long[] array, int size) {
+    this.array = array;
+    this.size = size;
+  }
+  
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof IntArrayList)) {
+      return super.equals(o);
+    }
+    LongArrayList other = (LongArrayList) o;
+    if (size != other.size) {
+      return false;
+    }
+    
+    final long[] arr = other.array;
+    for (int i = 0; i < size; i++) {
+      if (array[i] != arr[i]) {
+        return false;
       }
     }
+    
+    return true;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = 1;
+    for (int i = 0; i < size; i++) {
+      result = (31 * result) + Internal.hashLong(array[i]);
+    }
+    return result;
+  }
+
+  @Override
+  public LongList mutableCopyWithCapacity(int capacity) {
+    if (capacity < size) {
+      throw new IllegalArgumentException();
+    }
+    return new LongArrayList(Arrays.copyOf(array, capacity), size);
   }
   
   @Override

java/core/src/main/java/com/google/protobuf/MapEntryLite.java

@@ -41,7 +41,8 @@ import java.io.IOException;
  * 
  * Protobuf internal. Users shouldn't use.
  */
-public class MapEntryLite<K, V> extends AbstractMessageLite {
+public class MapEntryLite<K, V>
+    extends AbstractMessageLite<MapEntryLite<K, V>, MapEntryLite.Builder<K, V>> {
   private static class Metadata<K, V> {
     public final MapEntryLite<K, V> defaultInstance;
     public final WireFormat.FieldType keyType;
@@ -233,7 +234,7 @@ public class MapEntryLite<K, V> extends AbstractMessageLite {
    * Builder used to create {@link MapEntryLite} messages.
    */
   public static class Builder<K, V>
-      extends AbstractMessageLite.Builder<Builder<K, V>> {
+      extends AbstractMessageLite.Builder<MapEntryLite<K, V>, Builder<K, V>> {
     private final Metadata<K, V> metadata;
     private K key;
     private V value;
@@ -327,5 +328,10 @@ public class MapEntryLite<K, V> extends AbstractMessageLite {
       this.value = entry.value;
       return this;
     }
+
+    @Override
+    protected Builder<K, V> internalMergeFrom(MapEntryLite<K, V> message) {
+      throw new UnsupportedOperationException();
+    }
   }
 }

java/core/src/main/java/com/google/protobuf/MapField.java

@@ -93,15 +93,18 @@ public class MapField<K, V> implements MutabilityOracle {
       this.defaultEntry = defaultEntry;
     }
     
+    @Override
     public Message convertKeyAndValueToMessage(K key, V value) {
       return defaultEntry.newBuilderForType().setKey(key).setValue(value).buildPartial();
     }
     
+    @Override
     public void convertMessageToKeyAndValue(Message message, Map<K, V> map) {
       MapEntry<K, V> entry = (MapEntry<K, V>) message;
       map.put(entry.getKey(), entry.getValue());
     }
 
+    @Override
     public Message getMessageDefaultInstance() {
       return defaultEntry;
     }

java/core/src/main/java/com/google/protobuf/Message.java

@@ -51,6 +51,7 @@ import java.util.Map;
 public interface Message extends MessageLite, MessageOrBuilder {
 
   // (From MessageLite, re-declared here only for return type covariance.)
+  @Override
   Parser<? extends Message> getParserForType();
 
 
@@ -97,7 +98,10 @@ public interface Message extends MessageLite, MessageOrBuilder {
   // Builders
 
   // (From MessageLite, re-declared here only for return type covariance.)
+  @Override
   Builder newBuilderForType();
+
+  @Override
   Builder toBuilder();
 
   /**
@@ -106,6 +110,7 @@ public interface Message extends MessageLite, MessageOrBuilder {
   interface Builder extends MessageLite.Builder, MessageOrBuilder {
     // (From MessageLite.Builder, re-declared here only for return type
     // covariance.)
+    @Override
     Builder clear();
 
     /**
@@ -131,18 +136,27 @@ public interface Message extends MessageLite, MessageOrBuilder {
 
     // (From MessageLite.Builder, re-declared here only for return type
     // covariance.)
+    @Override
     Message build();
+
+    @Override
     Message buildPartial();
+
+    @Override
     Builder clone();
+
+    @Override
     Builder mergeFrom(CodedInputStream input) throws IOException;
-    Builder mergeFrom(CodedInputStream input,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws IOException;
+
+    @Override
+    Builder mergeFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException;
 
     /**
      * Get the message's type's descriptor.
      * See {@link Message#getDescriptorForType()}.
      */
+    @Override
     Descriptors.Descriptor getDescriptorForType();
 
     /**
@@ -240,27 +254,39 @@ public interface Message extends MessageLite, MessageOrBuilder {
 
     // (From MessageLite.Builder, re-declared here only for return type
     // covariance.)
+    @Override
     Builder mergeFrom(ByteString data) throws InvalidProtocolBufferException;
-    Builder mergeFrom(ByteString data,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(ByteString data, ExtensionRegistryLite extensionRegistry)
+        throws InvalidProtocolBufferException;
+
+    @Override
     Builder mergeFrom(byte[] data) throws InvalidProtocolBufferException;
-    Builder mergeFrom(byte[] data, int off, int len)
-                      throws InvalidProtocolBufferException;
-    Builder mergeFrom(byte[] data,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws InvalidProtocolBufferException;
-    Builder mergeFrom(byte[] data, int off, int len,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(byte[] data, int off, int len) throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(byte[] data, ExtensionRegistryLite extensionRegistry)
+        throws InvalidProtocolBufferException;
+
+    @Override
+    Builder mergeFrom(byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
+        throws InvalidProtocolBufferException;
+
+    @Override
     Builder mergeFrom(InputStream input) throws IOException;
-    Builder mergeFrom(InputStream input,
-                      ExtensionRegistryLite extensionRegistry)
-                      throws IOException;
-    boolean mergeDelimitedFrom(InputStream input)
-                               throws IOException;
-    boolean mergeDelimitedFrom(InputStream input,
-                               ExtensionRegistryLite extensionRegistry)
-                               throws IOException;
+
+    @Override
+    Builder mergeFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException;
+
+    @Override
+    boolean mergeDelimitedFrom(InputStream input) throws IOException;
+
+    @Override
+    boolean mergeDelimitedFrom(InputStream input, ExtensionRegistryLite extensionRegistry)
+        throws IOException;
   }
 }

java/core/src/main/java/com/google/protobuf/MessageLite.java

@@ -295,6 +295,27 @@ public interface MessageLite extends MessageLiteOrBuilder {
     Builder mergeFrom(InputStream input,
                       ExtensionRegistryLite extensionRegistry)
                       throws IOException;
+    
+    /**
+     * Merge {@code other} into the message being built.  {@code other} must
+     * have the exact same type as {@code this} (i.e.
+     * {@code getClass().equals(getDefaultInstanceForType().getClass())}).
+     *
+     * Merging occurs as follows.  For each field:<br>
+     * * For singular primitive fields, if the field is set in {@code other},
+     *   then {@code other}'s value overwrites the value in this message.<br>
+     * * For singular message fields, if the field is set in {@code other},
+     *   it is merged into the corresponding sub-message of this message
+     *   using the same merging rules.<br>
+     * * For repeated fields, the elements in {@code other} are concatenated
+     *   with the elements in this message.
+     * * For oneof groups, if the other message has one of the fields set,
+     *   the group of this message is cleared and replaced by the field
+     *   of the other message, so that the oneof constraint is preserved.
+     *
+     * This is equivalent to the {@code Message::MergeFrom} method in C++.
+     */
+    Builder mergeFrom(MessageLite other);
 
     /**
      * Like {@link #mergeFrom(InputStream)}, but does not read until EOF.

java/core/src/main/java/com/google/protobuf/MessageLiteToString.java

@@ -0,0 +1,239 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * Helps generate {@link String} representations of {@link MessageLite} protos.
+ */
+// TODO(dweis): Fix map fields.
+final class MessageLiteToString {
+
+  private static final String LIST_SUFFIX = "List";
+  private static final String BUILDER_LIST_SUFFIX = "OrBuilderList";
+  private static final String BYTES_SUFFIX = "Bytes";
+  
+  /**
+   * Returns a {@link String} representation of the {@link MessageLite} object.  The first line of
+   * the {@code String} representation representation includes a comment string to uniquely identify
+   * the objcet instance. This acts as an indicator that this should not be relied on for
+   * comparisons.
+   *
+   * <p>For use by generated code only.
+   */
+  static String toString(MessageLite messageLite, String commentString) {
+    StringBuilder buffer = new StringBuilder();
+    buffer.append("# ").append(commentString);
+    reflectivePrintWithIndent(messageLite, buffer, 0);
+    return buffer.toString();
+  }
+
+  /**
+   * Reflectively prints the {@link MessageLite} to the buffer at given {@code indent} level.
+   *
+   * @param buffer the buffer to write to
+   * @param indent the number of spaces to indent the proto by
+   */
+  private static void reflectivePrintWithIndent(
+      MessageLite messageLite, StringBuilder buffer, int indent) {
+    // Build a map of method name to method. We're looking for methods like getFoo(), hasFoo(), and
+    // getFooList() which might be useful for building an object's string representation.
+    Map<String, Method> nameToNoArgMethod = new HashMap<String, Method>();
+    Map<String, Method> nameToMethod = new HashMap<String, Method>();
+    Set<String> getters = new TreeSet<String>();
+    for (Method method : messageLite.getClass().getDeclaredMethods()) {
+      nameToMethod.put(method.getName(), method);
+      if (method.getParameterTypes().length == 0) {
+        nameToNoArgMethod.put(method.getName(), method);
+
+        if (method.getName().startsWith("get")) {
+          getters.add(method.getName());
+        }
+      }
+    }
+
+    for (String getter : getters) {
+      String suffix = getter.replaceFirst("get", "");
+      if (suffix.endsWith(LIST_SUFFIX) && !suffix.endsWith(BUILDER_LIST_SUFFIX)) {
+        String camelCase = suffix.substring(0, 1).toLowerCase()
+            + suffix.substring(1, suffix.length() - LIST_SUFFIX.length());
+        // Try to reflectively get the value and toString() the field as if it were repeated. This
+        // only works if the method names have not be proguarded out or renamed.
+        Method listMethod = nameToNoArgMethod.get("get" + suffix);
+        if (listMethod != null) {
+          printField(
+              buffer,
+              indent,
+              camelCaseToSnakeCase(camelCase),
+              GeneratedMessageLite.invokeOrDie(listMethod, messageLite));
+          continue;
+        }
+      }
+
+      Method setter = nameToMethod.get("set" + suffix);
+      if (setter == null) {
+        continue;
+      }
+      if (suffix.endsWith(BYTES_SUFFIX)
+          && nameToNoArgMethod.containsKey(
+              "get" + suffix.substring(0, suffix.length() - "Bytes".length()))) {
+        // Heuristic to skip bytes based accessors for string fields.
+        continue;
+      }
+      
+      String camelCase = suffix.substring(0, 1).toLowerCase() + suffix.substring(1);
+
+      // Try to reflectively get the value and toString() the field as if it were optional. This
+      // only works if the method names have not be proguarded out or renamed.
+      Method getMethod = nameToNoArgMethod.get("get" + suffix);
+      Method hasMethod = nameToNoArgMethod.get("has" + suffix);
+      // TODO(dweis): Fix proto3 semantics.
+      if (getMethod != null) {
+        Object value = GeneratedMessageLite.invokeOrDie(getMethod, messageLite);
+        final boolean hasValue = hasMethod == null
+            ? !isDefaultValue(value)
+            : (Boolean) GeneratedMessageLite.invokeOrDie(hasMethod, messageLite);
+         // TODO(dweis): This doesn't stop printing oneof case twice: value and enum style.
+        if (hasValue) {
+          printField(
+              buffer,
+              indent,
+              camelCaseToSnakeCase(camelCase),
+              value);
+        }
+        continue;
+      }
+    }
+
+    if (messageLite instanceof GeneratedMessageLite.ExtendableMessage) {
+      Iterator<Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object>> iter =
+          ((GeneratedMessageLite.ExtendableMessage<?, ?>) messageLite).extensions.iterator();
+      while (iter.hasNext()) {
+        Map.Entry<GeneratedMessageLite.ExtensionDescriptor, Object> entry = iter.next();
+        printField(buffer, indent, "[" + entry.getKey().getNumber() + "]", entry.getValue());
+      }
+    }
+
+    if (((GeneratedMessageLite<?, ?>) messageLite).unknownFields != null) {
+      ((GeneratedMessageLite<?, ?>) messageLite).unknownFields.printWithIndent(buffer, indent);
+    }
+  }
+  
+  private static boolean isDefaultValue(Object o) {
+    if (o instanceof Boolean) {
+      return !((Boolean) o);
+    }
+    if (o instanceof Integer) {
+      return ((Integer) o) == 0;
+    }
+    if (o instanceof Float) {
+      return ((Float) o) == 0f;
+    }
+    if (o instanceof Double) {
+      return ((Double) o) == 0d;
+    }
+    if (o instanceof String) {
+      return o.equals("");
+    }
+    if (o instanceof ByteString) {
+      return o.equals(ByteString.EMPTY);
+    }
+    if (o instanceof MessageLite) { // Can happen in oneofs.
+      return o == ((MessageLite) o).getDefaultInstanceForType();
+    }
+    if (o instanceof java.lang.Enum<?>) { // Catches oneof enums.
+      return ((java.lang.Enum<?>) o).ordinal() == 0;
+    }
+    
+    return false;
+  }
+
+  /**
+   * Formats a text proto field.
+   *
+   * <p>For use by generated code only.
+   *
+   * @param buffer the buffer to write to
+   * @param indent the number of spaces the proto should be indented by
+   * @param name the field name (in lower underscore case)
+   * @param object the object value of the field
+   */
+  static final void printField(StringBuilder buffer, int indent, String name, Object object) {
+    if (object instanceof List<?>) {
+      List<?> list = (List<?>) object;
+      for (Object entry : list) {
+        printField(buffer, indent, name, entry);
+      }
+      return;
+    }
+
+    buffer.append('\n');
+    for (int i = 0; i < indent; i++) {
+      buffer.append(' ');
+    }
+    buffer.append(name);
+
+    if (object instanceof String) {
+      buffer.append(": \"").append(TextFormatEscaper.escapeText((String) object)).append('"');
+    } else if (object instanceof ByteString) {
+      buffer.append(": \"").append(TextFormatEscaper.escapeBytes((ByteString) object)).append('"');
+    } else if (object instanceof GeneratedMessageLite) {
+      buffer.append(" {");
+      reflectivePrintWithIndent((GeneratedMessageLite<?, ?>) object, buffer, indent + 2);
+      buffer.append("\n");
+      for (int i = 0; i < indent; i++) {
+        buffer.append(' ');
+      }
+      buffer.append("}");
+    } else {
+      buffer.append(": ").append(object.toString());
+    }
+  }
+  
+  private static final String camelCaseToSnakeCase(String camelCase) {
+    StringBuilder builder = new StringBuilder();
+    for (int i = 0; i < camelCase.length(); i++) {
+      char ch = camelCase.charAt(i);
+      if (Character.isUpperCase(ch)) {
+        builder.append("_");
+      }
+      builder.append(Character.toLowerCase(ch));
+    }
+    return builder.toString();
+  }
+}

java/core/src/main/java/com/google/protobuf/MessageOrBuilder.java

@@ -42,7 +42,7 @@ import java.util.Map;
 public interface MessageOrBuilder extends MessageLiteOrBuilder {
 
   // (From MessageLite, re-declared here only for return type covariance.)
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   Message getDefaultInstanceForType();
 
   /**

java/core/src/main/java/com/google/protobuf/MessageReflection.java

@@ -364,12 +364,14 @@ class MessageReflection {
      * Finishes the merge and returns the underlying object.
      */
     Object finish();
+    
   }
 
   static class BuilderAdapter implements MergeTarget {
 
     private final Message.Builder builder;
 
+    @Override
     public Descriptors.Descriptor getDescriptorForType() {
       return builder.getDescriptorForType();
     }
@@ -378,6 +380,7 @@ class MessageReflection {
       this.builder = builder;
     }
 
+    @Override
     public Object getField(Descriptors.FieldDescriptor field) {
       return builder.getField(field);
     }
@@ -387,25 +390,27 @@ class MessageReflection {
       return builder.hasField(field);
     }
 
-    public MergeTarget setField(Descriptors.FieldDescriptor field,
-        Object value) {
+    @Override
+    public MergeTarget setField(Descriptors.FieldDescriptor field, Object value) {
       builder.setField(field, value);
       return this;
     }
 
+    @Override
     public MergeTarget clearField(Descriptors.FieldDescriptor field) {
       builder.clearField(field);
       return this;
     }
 
+    @Override
     public MergeTarget setRepeatedField(
         Descriptors.FieldDescriptor field, int index, Object value) {
       builder.setRepeatedField(field, index, value);
       return this;
     }
 
-    public MergeTarget addRepeatedField(
-        Descriptors.FieldDescriptor field, Object value) {
+    @Override
+    public MergeTarget addRepeatedField(Descriptors.FieldDescriptor field, Object value) {
       builder.addRepeatedField(field, value);
       return this;
     }
@@ -426,25 +431,30 @@ class MessageReflection {
       return builder.getOneofFieldDescriptor(oneof);
     }
 
+    @Override
     public ContainerType getContainerType() {
       return ContainerType.MESSAGE;
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByName(
         ExtensionRegistry registry, String name) {
       return registry.findImmutableExtensionByName(name);
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByNumber(
-        ExtensionRegistry registry, Descriptors.Descriptor containingType,
-        int fieldNumber) {
+        ExtensionRegistry registry, Descriptors.Descriptor containingType, int fieldNumber) {
       return registry.findImmutableExtensionByNumber(containingType,
           fieldNumber);
     }
 
-    public Object parseGroup(CodedInputStream input,
+    @Override
+    public Object parseGroup(
+        CodedInputStream input,
         ExtensionRegistryLite extensionRegistry,
-        Descriptors.FieldDescriptor field, Message defaultInstance)
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
         throws IOException {
       Message.Builder subBuilder;
       // When default instance is not null. The field is an extension field.
@@ -463,9 +473,12 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessage(CodedInputStream input,
+    @Override
+    public Object parseMessage(
+        CodedInputStream input,
         ExtensionRegistryLite extensionRegistry,
-        Descriptors.FieldDescriptor field, Message defaultInstance)
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
         throws IOException {
       Message.Builder subBuilder;
       // When default instance is not null. The field is an extension field.
@@ -484,9 +497,12 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessageFromBytes(ByteString bytes,
+    @Override
+    public Object parseMessageFromBytes(
+        ByteString bytes,
         ExtensionRegistryLite extensionRegistry,
-        Descriptors.FieldDescriptor field, Message defaultInstance)
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
         throws IOException {
       Message.Builder subBuilder;
       // When default instance is not null. The field is an extension field.
@@ -505,8 +521,9 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public MergeTarget newMergeTargetForField(Descriptors.FieldDescriptor field,
-        Message defaultInstance) {
+    @Override
+    public MergeTarget newMergeTargetForField(
+        Descriptors.FieldDescriptor field, Message defaultInstance) {
       if (defaultInstance != null) {
         return new BuilderAdapter(
             defaultInstance.newBuilderForType());
@@ -515,8 +532,8 @@ class MessageReflection {
       }
     }
 
-    public WireFormat.Utf8Validation
-        getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
+    @Override
+    public WireFormat.Utf8Validation getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
       if (descriptor.needsUtf8Check()) {
         return WireFormat.Utf8Validation.STRICT;
       }
@@ -528,9 +545,11 @@ class MessageReflection {
       return WireFormat.Utf8Validation.LOOSE;
     }
 
+    @Override
     public Object finish() {
       return builder.buildPartial();
     }
+    
   }
 
 
@@ -542,38 +561,43 @@ class MessageReflection {
       this.extensions = extensions;
     }
 
+    @Override
     public Descriptors.Descriptor getDescriptorForType() {
       throw new UnsupportedOperationException(
           "getDescriptorForType() called on FieldSet object");
     }
 
+    @Override
     public Object getField(Descriptors.FieldDescriptor field) {
       return extensions.getField(field);
     }
 
+    @Override
     public boolean hasField(Descriptors.FieldDescriptor field) {
       return extensions.hasField(field);
     }
 
-    public MergeTarget setField(Descriptors.FieldDescriptor field,
-        Object value) {
+    @Override
+    public MergeTarget setField(Descriptors.FieldDescriptor field, Object value) {
       extensions.setField(field, value);
       return this;
     }
 
+    @Override
     public MergeTarget clearField(Descriptors.FieldDescriptor field) {
       extensions.clearField(field);
       return this;
     }
 
+    @Override
     public MergeTarget setRepeatedField(
         Descriptors.FieldDescriptor field, int index, Object value) {
       extensions.setRepeatedField(field, index, value);
       return this;
     }
 
-    public MergeTarget addRepeatedField(
-        Descriptors.FieldDescriptor field, Object value) {
+    @Override
+    public MergeTarget addRepeatedField(Descriptors.FieldDescriptor field, Object value) {
       extensions.addRepeatedField(field, value);
       return this;
     }
@@ -594,25 +618,31 @@ class MessageReflection {
       return null;
     }
 
+    @Override
     public ContainerType getContainerType() {
       return ContainerType.EXTENSION_SET;
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByName(
         ExtensionRegistry registry, String name) {
       return registry.findImmutableExtensionByName(name);
     }
 
+    @Override
     public ExtensionRegistry.ExtensionInfo findExtensionByNumber(
-        ExtensionRegistry registry, Descriptors.Descriptor containingType,
-        int fieldNumber) {
+        ExtensionRegistry registry, Descriptors.Descriptor containingType, int fieldNumber) {
       return registry.findImmutableExtensionByNumber(containingType,
           fieldNumber);
     }
 
-    public Object parseGroup(CodedInputStream input,
-        ExtensionRegistryLite registry, Descriptors.FieldDescriptor field,
-        Message defaultInstance) throws IOException {
+    @Override
+    public Object parseGroup(
+        CodedInputStream input,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
       Message.Builder subBuilder =
           defaultInstance.newBuilderForType();
       if (!field.isRepeated()) {
@@ -625,9 +655,13 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessage(CodedInputStream input,
-        ExtensionRegistryLite registry, Descriptors.FieldDescriptor field,
-        Message defaultInstance) throws IOException {
+    @Override
+    public Object parseMessage(
+        CodedInputStream input,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
       Message.Builder subBuilder =
           defaultInstance.newBuilderForType();
       if (!field.isRepeated()) {
@@ -640,9 +674,13 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
-    public Object parseMessageFromBytes(ByteString bytes,
-        ExtensionRegistryLite registry, Descriptors.FieldDescriptor field,
-        Message defaultInstance) throws IOException {
+    @Override
+    public Object parseMessageFromBytes(
+        ByteString bytes,
+        ExtensionRegistryLite registry,
+        Descriptors.FieldDescriptor field,
+        Message defaultInstance)
+        throws IOException {
       Message.Builder subBuilder =  defaultInstance.newBuilderForType();
       if (!field.isRepeated()) {
         Message originalMessage = (Message) getField(field);
@@ -654,14 +692,15 @@ class MessageReflection {
       return subBuilder.buildPartial();
     }
 
+    @Override
     public MergeTarget newMergeTargetForField(
         Descriptors.FieldDescriptor descriptor, Message defaultInstance) {
       throw new UnsupportedOperationException(
           "newMergeTargetForField() called on FieldSet object");
     }
 
-    public WireFormat.Utf8Validation
-        getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
+    @Override
+    public WireFormat.Utf8Validation getUtf8Validation(Descriptors.FieldDescriptor descriptor) {
       if (descriptor.needsUtf8Check()) {
         return WireFormat.Utf8Validation.STRICT;
       }
@@ -669,10 +708,12 @@ class MessageReflection {
       return WireFormat.Utf8Validation.LOOSE;
     }
 
+    @Override
     public Object finish() {
       throw new UnsupportedOperationException(
           "finish() called on FieldSet object");
     }
+    
   }
 
   /**

java/core/src/main/java/com/google/protobuf/NioByteString.java

@@ -30,15 +30,14 @@
 
 package com.google.protobuf;
 
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InvalidObjectException;
 import java.io.ObjectInputStream;
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.nio.InvalidMarkException;
-import java.nio.channels.Channels;
 import java.nio.charset.Charset;
 import java.util.Collections;
 import java.util.List;
@@ -54,7 +53,7 @@ final class NioByteString extends ByteString.LeafByteString {
       throw new NullPointerException("buffer");
     }
 
-    this.buffer = buffer.slice();
+    this.buffer = buffer.slice().order(ByteOrder.nativeOrder());
   }
 
   // =================================================================
@@ -119,7 +118,7 @@ final class NioByteString extends ByteString.LeafByteString {
 
   @Override
   public void writeTo(OutputStream out) throws IOException {
-    writeToInternal(out, buffer.position(), buffer.remaining());
+    out.write(toByteArray());
   }
 
   @Override
@@ -137,14 +136,12 @@ final class NioByteString extends ByteString.LeafByteString {
       return;
     }
 
-    // Slow path
-    if (out instanceof FileOutputStream || numberToWrite >= 8192) {
-      // Use a channel to write out the ByteBuffer.
-      Channels.newChannel(out).write(slice(sourceOffset, sourceOffset + numberToWrite));
-    } else {
-      // Just copy the data to an array and write it.
-      out.write(toByteArray());
-    }
+    ByteBufferWriter.write(slice(sourceOffset, sourceOffset + numberToWrite), out);
+  }
+
+  @Override
+  void writeTo(ByteOutput output) throws IOException {
+    output.writeLazy(buffer.slice());
   }
 
   @Override
@@ -159,46 +156,30 @@ final class NioByteString extends ByteString.LeafByteString {
 
   @Override
   protected String toStringInternal(Charset charset) {
-    byte[] bytes;
-    int offset;
+    final byte[] bytes;
+    final int offset;
+    final int length;
     if (buffer.hasArray()) {
       bytes = buffer.array();
       offset = buffer.arrayOffset() + buffer.position();
+      length = buffer.remaining();
     } else {
+      // TODO(nathanmittler): Can we optimize this?
       bytes = toByteArray();
       offset = 0;
+      length = bytes.length;
     }
-    return new String(bytes, offset, size(), charset);
+    return new String(bytes, offset, length, charset);
   }
 
   @Override
   public boolean isValidUtf8() {
-    // TODO(nathanmittler): add a ByteBuffer fork for Utf8.isValidUtf8 to avoid the copy
-    byte[] bytes;
-    int startIndex;
-    if (buffer.hasArray()) {
-      bytes = buffer.array();
-      startIndex = buffer.arrayOffset() + buffer.position();
-    } else {
-      bytes = toByteArray();
-      startIndex = 0;
-    }
-    return Utf8.isValidUtf8(bytes, startIndex, startIndex + size());
+    return Utf8.isValidUtf8(buffer);
   }
 
   @Override
   protected int partialIsValidUtf8(int state, int offset, int length) {
-    // TODO(nathanmittler): TODO add a ByteBuffer fork for Utf8.partialIsValidUtf8 to avoid the copy
-    byte[] bytes;
-    int startIndex;
-    if (buffer.hasArray()) {
-      bytes = buffer.array();
-      startIndex = buffer.arrayOffset() + buffer.position();
-    } else {
-      bytes = toByteArray();
-      startIndex = 0;
-    }
-    return Utf8.partialIsValidUtf8(state, bytes, startIndex, startIndex + size());
+    return Utf8.partialIsValidUtf8(state, buffer, offset, offset + length);
   }
 
   @Override

java/core/src/main/java/com/google/protobuf/Parser.java

@@ -30,7 +30,6 @@
 
 package com.google.protobuf;
 
-import java.io.IOException;
 import java.io.InputStream;
 
 /**

java/core/src/main/java/com/google/protobuf/ProtobufArrayList.java

@@ -38,7 +38,7 @@ import java.util.List;
 /**
  * Implements {@link ProtobufList} for non-primitive and {@link String} types.
  */
-class ProtobufArrayList<E> extends AbstractProtobufList<E> {
+final class ProtobufArrayList<E> extends AbstractProtobufList<E> {
 
   private static final ProtobufArrayList<Object> EMPTY_LIST = new ProtobufArrayList<Object>();
   static {
@@ -51,17 +51,23 @@ class ProtobufArrayList<E> extends AbstractProtobufList<E> {
   }
   
   private final List<E> list;
-  
+
   ProtobufArrayList() {
-    list = new ArrayList<E>();
+    this(new ArrayList<E>(DEFAULT_CAPACITY));
   }
   
-  ProtobufArrayList(List<E> toCopy) {
-    list = new ArrayList<E>(toCopy);
+  private ProtobufArrayList(List<E> list) {
+    this.list = list;
   }
-  
-  ProtobufArrayList(int capacity) {
-    list = new ArrayList<E>(capacity);
+
+  @Override
+  public ProtobufArrayList<E> mutableCopyWithCapacity(int capacity) {
+    if (capacity < size()) {
+      throw new IllegalArgumentException();
+    }
+    List<E> newList = new ArrayList<E>(capacity);
+    newList.addAll(list);
+    return new ProtobufArrayList<E>(newList);
   }
   
   @Override

java/core/src/main/java/com/google/protobuf/ProtocolMessageEnum.java

@@ -42,6 +42,7 @@ public interface ProtocolMessageEnum extends Internal.EnumLite {
   /**
    * Return the value's numeric value as defined in the .proto file.
    */
+  @Override
   int getNumber();
 
   /**

java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java

@@ -579,7 +579,7 @@ public class RepeatedFieldBuilder
     }
   }
 
-  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  @Override
   public void markDirty() {
     onChanged();
   }
@@ -621,10 +621,12 @@ public class RepeatedFieldBuilder
       this.builder = builder;
     }
 
+    @Override
     public int size() {
       return this.builder.getCount();
     }
 
+    @Override
     public MType get(int index) {
       return builder.getMessage(index);
     }
@@ -654,10 +656,12 @@ public class RepeatedFieldBuilder
       this.builder = builder;
     }
 
+    @Override
     public int size() {
       return this.builder.getCount();
     }
 
+    @Override
     public BType get(int index) {
       return builder.getBuilder(index);
     }
@@ -687,10 +691,12 @@ public class RepeatedFieldBuilder
       this.builder = builder;
     }
 
+    @Override
     public int size() {
       return this.builder.getCount();
     }
 
+    @Override
     public IType get(int index) {
       return builder.getMessageOrBuilder(index);
     }

java/core/src/main/java/com/google/protobuf/RopeByteString.java

@@ -48,10 +48,11 @@ import java.util.Stack;
 /**
  * Class to represent {@code ByteStrings} formed by concatenation of other
  * ByteStrings, without copying the data in the pieces. The concatenation is
- * represented as a tree whose leaf nodes are each a {@link LiteralByteString}.
+ * represented as a tree whose leaf nodes are each a
+ * {@link com.google.protobuf.ByteString.LeafByteString}.
  *
  * <p>Most of the operation here is inspired by the now-famous paper <a
- * href="http://www.cs.ubc.ca/local/reading/proceedings/spe91-95/spe/vol25/issue12/spe986.pdf">
+ * href="https://web.archive.org/web/20060202015456/http://www.cs.ubc.ca/local/reading/proceedings/spe91-95/spe/vol25/issue12/spe986.pdf">
  * BAP95 </a> Ropes: an Alternative to Strings hans-j. boehm, russ atkinson and
  * michael plass
  *
@@ -139,8 +140,9 @@ final class RopeByteString extends ByteString {
   /**
    * Concatenate the given strings while performing various optimizations to
    * slow the growth rate of tree depth and tree node count. The result is
-   * either a {@link LiteralByteString} or a {@link RopeByteString}
-   * depending on which optimizations, if any, were applied.
+   * either a {@link com.google.protobuf.ByteString.LeafByteString} or a
+   * {@link RopeByteString} depending on which optimizations, if any, were
+   * applied.
    *
    * <p>Small pieces of length less than {@link
    * ByteString#CONCATENATE_BY_COPY_SIZE} may be copied by value here, as in
@@ -294,8 +296,7 @@ final class RopeByteString extends ByteString {
    *
    * <p>Substrings of {@code length < 2} should result in at most a single
    * recursive call chain, terminating at a leaf node. Thus the result will be a
-   * {@link LiteralByteString}. {@link #RopeByteString(ByteString,
-   * ByteString)}.
+   * {@link com.google.protobuf.ByteString.LeafByteString}.
    *
    * @param beginIndex start at this index
    * @param endIndex   the last character is the one before this index
@@ -368,7 +369,7 @@ final class RopeByteString extends ByteString {
 
   @Override
   public List<ByteBuffer> asReadOnlyByteBufferList() {
-    // Walk through the list of LiteralByteString's that make up this
+    // Walk through the list of LeafByteString's that make up this
     // rope, and add each one as a read-only ByteBuffer.
     List<ByteBuffer> result = new ArrayList<ByteBuffer>();
     PieceIterator pieces = new PieceIterator(this);
@@ -399,6 +400,12 @@ final class RopeByteString extends ByteString {
     }
   }
 
+  @Override
+  void writeTo(ByteOutput output) throws IOException {
+    left.writeTo(output);
+    right.writeTo(output);
+  }
+
   @Override
   protected String toStringInternal(Charset charset) {
     return new String(toByteArray(), charset);
@@ -709,9 +716,10 @@ final class RopeByteString extends ByteString {
     }
 
     /**
-     * Returns the next item and advances one {@code LiteralByteString}.
+     * Returns the next item and advances one
+     * {@link com.google.protobuf.ByteString.LeafByteString}.
      *
-     * @return next non-empty LiteralByteString or {@code null}
+     * @return next non-empty LeafByteString or {@code null}
      */
     @Override
     public LeafByteString next() {