Change protobuf CPP proto generator to support the 'lite' option in

proto3.

Added a couple unit test proto3 files, for arena_lite and lite. Cloned
the proto3_arena_unittest to test some of the basics of generated code
(and to ensure that the generated proto3 test files are used by some
test).

9 files changed, 743 insertions, 29 deletions

diff --git a/BUILD b/BUILD
index 1615486f..09d917b7 100644
--- a/BUILD
+++ b/BUILD
@@ -376,6 +376,8 @@ 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",
@@ -461,6 +463,8 @@ cc_test(
         "src/google/protobuf/no_field_presence_test.cc",
         "src/google/protobuf/preserve_unknown_enum_test.cc",
         "src/google/protobuf/proto3_arena_unittest.cc",
+        "src/google/protobuf/proto3_arena_lite_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",
diff --git a/src/Makefile.am b/src/Makefile.am
index 2ba0ef9b..80065506 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -507,6 +507,8 @@ protoc_inputs =                                                   \
   google/protobuf/unittest_preserve_unknown_enum.proto            \
   google/protobuf/unittest.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              \
@@ -609,6 +611,10 @@ protoc_outputs =                                                  \
   google/protobuf/unittest_preserve_unknown_enum.pb.h             \
   google/protobuf/unittest_proto3_arena.pb.cc                     \
   google/protobuf/unittest_proto3_arena.pb.h                      \
+  google/protobuf/unittest_proto3_arena_lite.pb.cc                     \
+  google/protobuf/unittest_proto3_arena_lite.pb.h                      \
+  google/protobuf/unittest_proto3_lite.pb.cc                     \
+  google/protobuf/unittest_proto3_lite.pb.h                      \
   google/protobuf/unittest_well_known_types.pb.cc                 \
   google/protobuf/unittest_well_known_types.pb.h                  \
   google/protobuf/util/internal/testdata/anys.pb.cc               \
@@ -710,6 +716,8 @@ protobuf_test_SOURCES =                                        \
   google/protobuf/no_field_presence_test.cc                    \
   google/protobuf/preserve_unknown_enum_test.cc                \
   google/protobuf/proto3_arena_unittest.cc                     \
+  google/protobuf/proto3_arena_lite_unittest.cc                     \
+  google/protobuf/proto3_lite_unittest.cc                     \
   google/protobuf/reflection_ops_unittest.cc                   \
   google/protobuf/repeated_field_reflection_unittest.cc        \
   google/protobuf/repeated_field_unittest.cc                   \
diff --git a/src/google/protobuf/compiler/cpp/cpp_message.cc b/src/google/protobuf/compiler/cpp/cpp_message.cc
index c3166611..9bd5cf51 100644
--- a/src/google/protobuf/compiler/cpp/cpp_message.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_message.cc
@@ -1777,7 +1777,8 @@ void MessageGenerator::
 GenerateClassMethods(io::Printer* printer) {
   // mutable_unknown_fields wrapper function for LazyStringOutputStream
   // callback.
-  if (!UseUnknownFieldSet(descriptor_->file())) {
+  if (PreserveUnknownFields(descriptor_) &&
+      !UseUnknownFieldSet(descriptor_->file())) {
     printer->Print(
         "static ::std::string* MutableUnknownFieldsFor$classname$(\n"
         "    $classname$* ptr) {\n"
@@ -2656,18 +2657,13 @@ GenerateSwap(io::Printer* printer) {
       }
     }
 
-    if (PreserveUnknownFields(descriptor_)) {
-      if (UseUnknownFieldSet(descriptor_->file())) {
-        printer->Print(
+    // Ignore PreserveUnknownFields here - always swap internal_metadata as it
+    // may contain more than just unknown fields.
+    if (UseUnknownFieldSet(descriptor_->file())) {
+      printer->Print(
           "_internal_metadata_.Swap(&other->_internal_metadata_);\n");
-      } else {
-        printer->Print("_unknown_fields_.Swap(&other->_unknown_fields_);\n");
-      }
     } else {
-      // Still swap internal_metadata as it may contain more than just
-      // unknown fields.
-      printer->Print(
-        "_internal_metadata_.Swap(&other->_internal_metadata_);\n");
+      printer->Print("_unknown_fields_.Swap(&other->_unknown_fields_);\n");
     }
     printer->Print("std::swap(_cached_size_, other->_cached_size_);\n");
     if (descriptor_->extension_range_count() > 0) {
@@ -2908,7 +2904,8 @@ GenerateMergeFromCodedStream(io::Printer* printer) {
     "  ::google::protobuf::uint32 tag;\n",
     "classname", classname_);
 
-  if (!UseUnknownFieldSet(descriptor_->file())) {
+  if (PreserveUnknownFields(descriptor_) &&
+      !UseUnknownFieldSet(descriptor_->file())) {
     // Use LazyStringOutputString to avoid initializing unknown fields string
     // unless it is actually needed. For the same reason, disable eager refresh
     // on the CodedOutputStream.
diff --git a/src/google/protobuf/descriptor.cc b/src/google/protobuf/descriptor.cc
index 78a34617..f46c7f23 100644
--- a/src/google/protobuf/descriptor.cc
+++ b/src/google/protobuf/descriptor.cc
@@ -5113,11 +5113,6 @@ void DescriptorBuilder::ValidateProto3(
   for (int i = 0; i < file->enum_type_count(); ++i) {
     ValidateProto3Enum(file->enum_types_ + i, proto.enum_type(i));
   }
-  if (IsLite(file)) {
-    AddError(file->name(), proto,
-             DescriptorPool::ErrorCollector::OTHER,
-             "Lite runtime is not supported in proto3.");
-  }
 }
 
 static string ToLowercaseWithoutUnderscores(const string& name) {
diff --git a/src/google/protobuf/descriptor_unittest.cc b/src/google/protobuf/descriptor_unittest.cc
index e4720a7e..f937b9ea 100644
--- a/src/google/protobuf/descriptor_unittest.cc
+++ b/src/google/protobuf/descriptor_unittest.cc
@@ -5740,18 +5740,6 @@ TEST_F(ValidationErrorTest, ValidateProto3Enum) {
       "}");
 }
 
-TEST_F(ValidationErrorTest, ValidateProto3LiteRuntime) {
-  // Lite runtime is not supported in proto3.
-  BuildFileWithErrors(
-      "name: 'foo.proto' "
-      "syntax: 'proto3' "
-      "options { "
-      "  optimize_for: LITE_RUNTIME "
-      "} ",
-      "foo.proto: foo.proto: OTHER: Lite runtime is not supported "
-      "in proto3.\n");
-}
-
 TEST_F(ValidationErrorTest, ValidateProto3Group) {
   BuildFileWithErrors(
       "name: 'foo.proto' "
diff --git a/src/google/protobuf/proto3_arena_lite_unittest.cc b/src/google/protobuf/proto3_arena_lite_unittest.cc
new file mode 100644
index 00000000..0f18c027
--- /dev/null
+++ b/src/google/protobuf/proto3_arena_lite_unittest.cc
@@ -0,0 +1,164 @@
+// 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 <string>
+#include <memory>
+#ifndef _SHARED_PTR_H
+#include <google/protobuf/stubs/shared_ptr.h>
+#endif
+#include <vector>
+
+#include <google/protobuf/test_util.h>
+#include <google/protobuf/unittest.pb.h>
+#include <google/protobuf/unittest_proto3_arena_lite.pb.h>
+#include <google/protobuf/arena.h>
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+
+namespace google {
+using proto3_arena_lite_unittest::TestAllTypes;
+
+namespace protobuf {
+namespace {
+// We selectively set/check a few representative fields rather than all fields
+// as this test is only expected to cover the basics of arena support.
+void SetAllFields(TestAllTypes* m) {
+  m->set_optional_int32(100);
+  m->set_optional_string("asdf");
+  m->set_optional_bytes("jkl;");
+  m->mutable_optional_nested_message()->set_bb(42);
+  m->mutable_optional_foreign_message()->set_c(43);
+  m->set_optional_nested_enum(
+      proto3_arena_lite_unittest::TestAllTypes_NestedEnum_BAZ);
+  m->set_optional_foreign_enum(
+      proto3_arena_lite_unittest::FOREIGN_BAZ);
+  m->mutable_optional_lazy_message()->set_bb(45);
+  m->add_repeated_int32(100);
+  m->add_repeated_string("asdf");
+  m->add_repeated_bytes("jkl;");
+  m->add_repeated_nested_message()->set_bb(46);
+  m->add_repeated_foreign_message()->set_c(47);
+  m->add_repeated_nested_enum(
+      proto3_arena_lite_unittest::TestAllTypes_NestedEnum_BAZ);
+  m->add_repeated_foreign_enum(
+      proto3_arena_lite_unittest::FOREIGN_BAZ);
+  m->add_repeated_lazy_message()->set_bb(49);
+
+  m->set_oneof_uint32(1);
+  m->mutable_oneof_nested_message()->set_bb(50);
+  m->set_oneof_string("test");  // only this one remains set
+}
+
+void ExpectAllFieldsSet(const TestAllTypes& m) {
+  EXPECT_EQ(100, m.optional_int32());
+  EXPECT_EQ("asdf", m.optional_string());
+  EXPECT_EQ("jkl;", m.optional_bytes());
+  EXPECT_EQ(true, m.has_optional_nested_message());
+  EXPECT_EQ(42, m.optional_nested_message().bb());
+  EXPECT_EQ(true, m.has_optional_foreign_message());
+  EXPECT_EQ(43, m.optional_foreign_message().c());
+  EXPECT_EQ(proto3_arena_lite_unittest::TestAllTypes_NestedEnum_BAZ,
+            m.optional_nested_enum());
+  EXPECT_EQ(proto3_arena_lite_unittest::FOREIGN_BAZ,
+            m.optional_foreign_enum());
+  EXPECT_EQ(true, m.has_optional_lazy_message());
+  EXPECT_EQ(45, m.optional_lazy_message().bb());
+
+  EXPECT_EQ(1, m.repeated_int32_size());
+  EXPECT_EQ(100, m.repeated_int32(0));
+  EXPECT_EQ(1, m.repeated_string_size());
+  EXPECT_EQ("asdf", m.repeated_string(0));
+  EXPECT_EQ(1, m.repeated_bytes_size());
+  EXPECT_EQ("jkl;", m.repeated_bytes(0));
+  EXPECT_EQ(1, m.repeated_nested_message_size());
+  EXPECT_EQ(46, m.repeated_nested_message(0).bb());
+  EXPECT_EQ(1, m.repeated_foreign_message_size());
+  EXPECT_EQ(47, m.repeated_foreign_message(0).c());
+  EXPECT_EQ(1, m.repeated_nested_enum_size());
+  EXPECT_EQ(proto3_arena_lite_unittest::TestAllTypes_NestedEnum_BAZ,
+            m.repeated_nested_enum(0));
+  EXPECT_EQ(1, m.repeated_foreign_enum_size());
+  EXPECT_EQ(proto3_arena_lite_unittest::FOREIGN_BAZ,
+            m.repeated_foreign_enum(0));
+  EXPECT_EQ(1, m.repeated_lazy_message_size());
+  EXPECT_EQ(49, m.repeated_lazy_message(0).bb());
+
+  EXPECT_EQ(proto3_arena_lite_unittest::TestAllTypes::kOneofString,
+            m.oneof_field_case());
+  EXPECT_EQ("test", m.oneof_string());
+}
+
+// In this file we only test some basic functionalities of arena support in
+// proto3 and expect the arena support to be fully tested in proto2 unittests
+// because proto3 shares most code with proto2.
+
+TEST(Proto3ArenaLiteTest, Parsing) {
+  TestAllTypes original;
+  SetAllFields(&original);
+
+  Arena arena;
+  TestAllTypes* arena_message = Arena::CreateMessage<TestAllTypes>(&arena);
+  arena_message->ParseFromString(original.SerializeAsString());
+  ExpectAllFieldsSet(*arena_message);
+}
+
+TEST(Proto3ArenaLiteTest, Swap) {
+  Arena arena1;
+  Arena arena2;
+
+  // Test Swap().
+  TestAllTypes* arena1_message = Arena::CreateMessage<TestAllTypes>(&arena1);
+  TestAllTypes* arena2_message = Arena::CreateMessage<TestAllTypes>(&arena2);
+  arena1_message->Swap(arena2_message);
+  EXPECT_EQ(&arena1, arena1_message->GetArena());
+  EXPECT_EQ(&arena2, arena2_message->GetArena());
+}
+
+TEST(Proto3ArenaLiteTest, SetAllocatedMessage) {
+  Arena arena;
+  TestAllTypes *arena_message = Arena::CreateMessage<TestAllTypes>(&arena);
+  TestAllTypes::NestedMessage* nested = new TestAllTypes::NestedMessage;
+  nested->set_bb(118);
+  arena_message->set_allocated_optional_nested_message(nested);
+  EXPECT_EQ(118, arena_message->optional_nested_message().bb());
+}
+
+TEST(Proto3ArenaLiteTest, ReleaseMessage) {
+  Arena arena;
+  TestAllTypes* arena_message = Arena::CreateMessage<TestAllTypes>(&arena);
+  arena_message->mutable_optional_nested_message()->set_bb(118);
+  google::protobuf::scoped_ptr<TestAllTypes::NestedMessage> nested(
+      arena_message->release_optional_nested_message());
+  EXPECT_EQ(118, nested->bb());
+}
+
+}  // namespace
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/proto3_lite_unittest.cc b/src/google/protobuf/proto3_lite_unittest.cc
new file mode 100644
index 00000000..2e2beea9
--- /dev/null
+++ b/src/google/protobuf/proto3_lite_unittest.cc
@@ -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.
+
+#include <string>
+#include <memory>
+#ifndef _SHARED_PTR_H
+#include <google/protobuf/stubs/shared_ptr.h>
+#endif
+#include <vector>
+
+#include <google/protobuf/test_util.h>
+#include <google/protobuf/unittest.pb.h>
+#include <google/protobuf/unittest_proto3_lite.pb.h>
+#include <google/protobuf/arena.h>
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+
+namespace google {
+using proto3_lite_unittest::TestAllTypes;
+
+namespace protobuf {
+namespace {
+// We selectively set/check a few representative fields rather than all fields
+// as this test is only expected to cover the basics of lite support.
+void SetAllFields(TestAllTypes* m) {
+  m->set_optional_int32(100);
+  m->set_optional_string("asdf");
+  m->set_optional_bytes("jkl;");
+  m->mutable_optional_nested_message()->set_bb(42);
+  m->mutable_optional_foreign_message()->set_c(43);
+  m->set_optional_nested_enum(
+      proto3_lite_unittest::TestAllTypes_NestedEnum_BAZ);
+  m->set_optional_foreign_enum(
+      proto3_lite_unittest::FOREIGN_BAZ);
+  m->mutable_optional_lazy_message()->set_bb(45);
+  m->add_repeated_int32(100);
+  m->add_repeated_string("asdf");
+  m->add_repeated_bytes("jkl;");
+  m->add_repeated_nested_message()->set_bb(46);
+  m->add_repeated_foreign_message()->set_c(47);
+  m->add_repeated_nested_enum(
+      proto3_lite_unittest::TestAllTypes_NestedEnum_BAZ);
+  m->add_repeated_foreign_enum(
+      proto3_lite_unittest::FOREIGN_BAZ);
+  m->add_repeated_lazy_message()->set_bb(49);
+
+  m->set_oneof_uint32(1);
+  m->mutable_oneof_nested_message()->set_bb(50);
+  m->set_oneof_string("test");  // only this one remains set
+}
+
+void ExpectAllFieldsSet(const TestAllTypes& m) {
+  EXPECT_EQ(100, m.optional_int32());
+  EXPECT_EQ("asdf", m.optional_string());
+  EXPECT_EQ("jkl;", m.optional_bytes());
+  EXPECT_EQ(true, m.has_optional_nested_message());
+  EXPECT_EQ(42, m.optional_nested_message().bb());
+  EXPECT_EQ(true, m.has_optional_foreign_message());
+  EXPECT_EQ(43, m.optional_foreign_message().c());
+  EXPECT_EQ(proto3_lite_unittest::TestAllTypes_NestedEnum_BAZ,
+            m.optional_nested_enum());
+  EXPECT_EQ(proto3_lite_unittest::FOREIGN_BAZ,
+            m.optional_foreign_enum());
+  EXPECT_EQ(true, m.has_optional_lazy_message());
+  EXPECT_EQ(45, m.optional_lazy_message().bb());
+
+  EXPECT_EQ(1, m.repeated_int32_size());
+  EXPECT_EQ(100, m.repeated_int32(0));
+  EXPECT_EQ(1, m.repeated_string_size());
+  EXPECT_EQ("asdf", m.repeated_string(0));
+  EXPECT_EQ(1, m.repeated_bytes_size());
+  EXPECT_EQ("jkl;", m.repeated_bytes(0));
+  EXPECT_EQ(1, m.repeated_nested_message_size());
+  EXPECT_EQ(46, m.repeated_nested_message(0).bb());
+  EXPECT_EQ(1, m.repeated_foreign_message_size());
+  EXPECT_EQ(47, m.repeated_foreign_message(0).c());
+  EXPECT_EQ(1, m.repeated_nested_enum_size());
+  EXPECT_EQ(proto3_lite_unittest::TestAllTypes_NestedEnum_BAZ,
+            m.repeated_nested_enum(0));
+  EXPECT_EQ(1, m.repeated_foreign_enum_size());
+  EXPECT_EQ(proto3_lite_unittest::FOREIGN_BAZ,
+            m.repeated_foreign_enum(0));
+  EXPECT_EQ(1, m.repeated_lazy_message_size());
+  EXPECT_EQ(49, m.repeated_lazy_message(0).bb());
+
+  EXPECT_EQ(proto3_lite_unittest::TestAllTypes::kOneofString,
+            m.oneof_field_case());
+  EXPECT_EQ("test", m.oneof_string());
+}
+
+// In this file we only test some basic functionalities of in proto3 and expect
+// the rest is fully tested in proto2 unittests because proto3 shares most code
+// with proto2.
+
+TEST(Proto3LiteTest, Parsing) {
+  TestAllTypes original;
+  SetAllFields(&original);
+
+  TestAllTypes msg;
+  msg.ParseFromString(original.SerializeAsString());
+  ExpectAllFieldsSet(msg);
+}
+
+TEST(Proto3LiteTest, Swap) {
+  // Test Swap().
+  TestAllTypes msg1;
+  TestAllTypes msg2;
+  msg1.set_optional_string("123");
+  msg2.set_optional_string("3456");
+  msg1.Swap(&msg2);
+  EXPECT_EQ("3456", msg1.optional_string());
+  EXPECT_EQ("123", msg2.optional_string());
+  EXPECT_EQ(msg1.ByteSize(), msg2.ByteSize() + 1);
+}
+
+}  // namespace
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/unittest_proto3_arena_lite.proto b/src/google/protobuf/unittest_proto3_arena_lite.proto
new file mode 100644
index 00000000..5a60b90f
--- /dev/null
+++ b/src/google/protobuf/unittest_proto3_arena_lite.proto
@@ -0,0 +1,207 @@
+// 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";
+
+option cc_enable_arenas = true;
+option optimize_for = LITE_RUNTIME;
+
+import "google/protobuf/unittest_import.proto";
+
+package proto3_arena_lite_unittest;
+
+// This proto includes every type of field in both singular and repeated
+// forms.
+message TestAllTypes {
+  message NestedMessage {
+    // The field name "b" fails to compile in proto1 because it conflicts with
+    // a local variable named "b" in one of the generated methods.  Doh.
+    // This file needs to compile in proto1 to test backwards-compatibility.
+    int32 bb = 1;
+  }
+
+  enum NestedEnum {
+    ZERO = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+    NEG = -1;  // Intentionally negative.
+  }
+
+  // Singular
+     int32 optional_int32    =  1;
+     int64 optional_int64    =  2;
+    uint32 optional_uint32   =  3;
+    uint64 optional_uint64   =  4;
+    sint32 optional_sint32   =  5;
+    sint64 optional_sint64   =  6;
+   fixed32 optional_fixed32  =  7;
+   fixed64 optional_fixed64  =  8;
+  sfixed32 optional_sfixed32 =  9;
+  sfixed64 optional_sfixed64 = 10;
+     float optional_float    = 11;
+    double optional_double   = 12;
+      bool optional_bool     = 13;
+    string optional_string   = 14;
+     bytes optional_bytes    = 15;
+
+  // Groups are not allowed in proto3.
+  // optional group OptionalGroup = 16 {
+  //   optional int32 a = 17;
+  // }
+
+  NestedMessage                        optional_nested_message  = 18;
+  ForeignMessage                       optional_foreign_message = 19;
+  protobuf_unittest_import.ImportMessage optional_import_message  = 20;
+
+  NestedEnum                           optional_nested_enum     = 21;
+  ForeignEnum                          optional_foreign_enum    = 22;
+
+  // Omitted (compared to unittest.proto) because proto2 enums are not allowed
+  // inside proto2 messages.
+  //
+  // optional protobuf_unittest_import.ImportEnum    optional_import_enum  = 23;
+
+  string optional_string_piece = 24 [ctype=STRING_PIECE];
+  string optional_cord = 25 [ctype=CORD];
+
+  // Defined in unittest_import_public.proto
+  protobuf_unittest_import.PublicImportMessage
+      optional_public_import_message = 26;
+
+  NestedMessage optional_lazy_message = 27 [lazy=true];
+
+  // Repeated
+  repeated    int32 repeated_int32    = 31;
+  repeated    int64 repeated_int64    = 32;
+  repeated   uint32 repeated_uint32   = 33;
+  repeated   uint64 repeated_uint64   = 34;
+  repeated   sint32 repeated_sint32   = 35;
+  repeated   sint64 repeated_sint64   = 36;
+  repeated  fixed32 repeated_fixed32  = 37;
+  repeated  fixed64 repeated_fixed64  = 38;
+  repeated sfixed32 repeated_sfixed32 = 39;
+  repeated sfixed64 repeated_sfixed64 = 40;
+  repeated    float repeated_float    = 41;
+  repeated   double repeated_double   = 42;
+  repeated     bool repeated_bool     = 43;
+  repeated   string repeated_string   = 44;
+  repeated    bytes repeated_bytes    = 45;
+
+  // Groups are not allowed in proto3.
+  // repeated group RepeatedGroup = 46 {
+  //   optional int32 a = 47;
+  // }
+
+  repeated NestedMessage                        repeated_nested_message  = 48;
+  repeated ForeignMessage                       repeated_foreign_message = 49;
+  repeated protobuf_unittest_import.ImportMessage repeated_import_message  = 50;
+
+  repeated NestedEnum                           repeated_nested_enum     = 51;
+  repeated ForeignEnum                          repeated_foreign_enum    = 52;
+
+  // Omitted (compared to unittest.proto) because proto2 enums are not allowed
+  // inside proto2 messages.
+  //
+  // repeated protobuf_unittest_import.ImportEnum    repeated_import_enum  = 53;
+
+  repeated string repeated_string_piece = 54 [ctype=STRING_PIECE];
+  repeated string repeated_cord = 55 [ctype=CORD];
+
+  repeated NestedMessage repeated_lazy_message = 57 [lazy=true];
+
+  oneof oneof_field {
+    uint32 oneof_uint32 = 111;
+    NestedMessage oneof_nested_message = 112;
+    string oneof_string = 113;
+    bytes oneof_bytes = 114;
+  }
+}
+
+// Test messages for packed fields
+
+message TestPackedTypes {
+  repeated    int32 packed_int32    =  90 [packed = true];
+  repeated    int64 packed_int64    =  91 [packed = true];
+  repeated   uint32 packed_uint32   =  92 [packed = true];
+  repeated   uint64 packed_uint64   =  93 [packed = true];
+  repeated   sint32 packed_sint32   =  94 [packed = true];
+  repeated   sint64 packed_sint64   =  95 [packed = true];
+  repeated  fixed32 packed_fixed32  =  96 [packed = true];
+  repeated  fixed64 packed_fixed64  =  97 [packed = true];
+  repeated sfixed32 packed_sfixed32 =  98 [packed = true];
+  repeated sfixed64 packed_sfixed64 =  99 [packed = true];
+  repeated    float packed_float    = 100 [packed = true];
+  repeated   double packed_double   = 101 [packed = true];
+  repeated     bool packed_bool     = 102 [packed = true];
+  repeated ForeignEnum packed_enum  = 103 [packed = true];
+}
+
+// Explicitly set packed to false
+message TestUnpackedTypes {
+  repeated    int32 repeated_int32    =  1 [packed = false];
+  repeated    int64 repeated_int64    =  2 [packed = false];
+  repeated   uint32 repeated_uint32   =  3 [packed = false];
+  repeated   uint64 repeated_uint64   =  4 [packed = false];
+  repeated   sint32 repeated_sint32   =  5 [packed = false];
+  repeated   sint64 repeated_sint64   =  6 [packed = false];
+  repeated  fixed32 repeated_fixed32  =  7 [packed = false];
+  repeated  fixed64 repeated_fixed64  =  8 [packed = false];
+  repeated sfixed32 repeated_sfixed32 =  9 [packed = false];
+  repeated sfixed64 repeated_sfixed64 = 10 [packed = false];
+  repeated    float repeated_float    = 11 [packed = false];
+  repeated   double repeated_double   = 12 [packed = false];
+  repeated     bool repeated_bool     = 13 [packed = false];
+  repeated TestAllTypes.NestedEnum repeated_nested_enum = 14 [packed = false];
+}
+
+// This proto includes a recusively nested message.
+message NestedTestAllTypes {
+  NestedTestAllTypes child = 1;
+  TestAllTypes payload = 2;
+}
+
+// Define these after TestAllTypes to make sure the compiler can handle
+// that.
+message ForeignMessage {
+  int32 c = 1;
+}
+
+enum ForeignEnum {
+  FOREIGN_ZERO = 0;
+  FOREIGN_FOO = 4;
+  FOREIGN_BAR = 5;
+  FOREIGN_BAZ = 6;
+}
+
+// TestEmptyMessage is used to test behavior of unknown fields.
+message TestEmptyMessage {
+}
+
diff --git a/src/google/protobuf/unittest_proto3_lite.proto b/src/google/protobuf/unittest_proto3_lite.proto
new file mode 100644
index 00000000..874ade6c
--- /dev/null
+++ b/src/google/protobuf/unittest_proto3_lite.proto
@@ -0,0 +1,206 @@
+// 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";
+
+option optimize_for = LITE_RUNTIME;
+
+import "google/protobuf/unittest_import.proto";
+
+package proto3_lite_unittest;
+
+// This proto includes every type of field in both singular and repeated
+// forms.
+message TestAllTypes {
+  message NestedMessage {
+    // The field name "b" fails to compile in proto1 because it conflicts with
+    // a local variable named "b" in one of the generated methods.  Doh.
+    // This file needs to compile in proto1 to test backwards-compatibility.
+    int32 bb = 1;
+  }
+
+  enum NestedEnum {
+    ZERO = 0;
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+    NEG = -1;  // Intentionally negative.
+  }
+
+  // Singular
+     int32 optional_int32    =  1;
+     int64 optional_int64    =  2;
+    uint32 optional_uint32   =  3;
+    uint64 optional_uint64   =  4;
+    sint32 optional_sint32   =  5;
+    sint64 optional_sint64   =  6;
+   fixed32 optional_fixed32  =  7;
+   fixed64 optional_fixed64  =  8;
+  sfixed32 optional_sfixed32 =  9;
+  sfixed64 optional_sfixed64 = 10;
+     float optional_float    = 11;
+    double optional_double   = 12;
+      bool optional_bool     = 13;
+    string optional_string   = 14;
+     bytes optional_bytes    = 15;
+
+  // Groups are not allowed in proto3.
+  // optional group OptionalGroup = 16 {
+  //   optional int32 a = 17;
+  // }
+
+  NestedMessage                        optional_nested_message  = 18;
+  ForeignMessage                       optional_foreign_message = 19;
+  protobuf_unittest_import.ImportMessage optional_import_message  = 20;
+
+  NestedEnum                           optional_nested_enum     = 21;
+  ForeignEnum                          optional_foreign_enum    = 22;
+
+  // Omitted (compared to unittest.proto) because proto2 enums are not allowed
+  // inside proto2 messages.
+  //
+  // optional protobuf_unittest_import.ImportEnum    optional_import_enum  = 23;
+
+  string optional_string_piece = 24 [ctype=STRING_PIECE];
+  string optional_cord = 25 [ctype=CORD];
+
+  // Defined in unittest_import_public.proto
+  protobuf_unittest_import.PublicImportMessage
+      optional_public_import_message = 26;
+
+  NestedMessage optional_lazy_message = 27 [lazy=true];
+
+  // Repeated
+  repeated    int32 repeated_int32    = 31;
+  repeated    int64 repeated_int64    = 32;
+  repeated   uint32 repeated_uint32   = 33;
+  repeated   uint64 repeated_uint64   = 34;
+  repeated   sint32 repeated_sint32   = 35;
+  repeated   sint64 repeated_sint64   = 36;
+  repeated  fixed32 repeated_fixed32  = 37;
+  repeated  fixed64 repeated_fixed64  = 38;
+  repeated sfixed32 repeated_sfixed32 = 39;
+  repeated sfixed64 repeated_sfixed64 = 40;
+  repeated    float repeated_float    = 41;
+  repeated   double repeated_double   = 42;
+  repeated     bool repeated_bool     = 43;
+  repeated   string repeated_string   = 44;
+  repeated    bytes repeated_bytes    = 45;
+
+  // Groups are not allowed in proto3.
+  // repeated group RepeatedGroup = 46 {
+  //   optional int32 a = 47;
+  // }
+
+  repeated NestedMessage                        repeated_nested_message  = 48;
+  repeated ForeignMessage                       repeated_foreign_message = 49;
+  repeated protobuf_unittest_import.ImportMessage repeated_import_message  = 50;
+
+  repeated NestedEnum                           repeated_nested_enum     = 51;
+  repeated ForeignEnum                          repeated_foreign_enum    = 52;
+
+  // Omitted (compared to unittest.proto) because proto2 enums are not allowed
+  // inside proto2 messages.
+  //
+  // repeated protobuf_unittest_import.ImportEnum    repeated_import_enum  = 53;
+
+  repeated string repeated_string_piece = 54 [ctype=STRING_PIECE];
+  repeated string repeated_cord = 55 [ctype=CORD];
+
+  repeated NestedMessage repeated_lazy_message = 57 [lazy=true];
+
+  oneof oneof_field {
+    uint32 oneof_uint32 = 111;
+    NestedMessage oneof_nested_message = 112;
+    string oneof_string = 113;
+    bytes oneof_bytes = 114;
+  }
+}
+
+// Test messages for packed fields
+
+message TestPackedTypes {
+  repeated    int32 packed_int32    =  90 [packed = true];
+  repeated    int64 packed_int64    =  91 [packed = true];
+  repeated   uint32 packed_uint32   =  92 [packed = true];
+  repeated   uint64 packed_uint64   =  93 [packed = true];
+  repeated   sint32 packed_sint32   =  94 [packed = true];
+  repeated   sint64 packed_sint64   =  95 [packed = true];
+  repeated  fixed32 packed_fixed32  =  96 [packed = true];
+  repeated  fixed64 packed_fixed64  =  97 [packed = true];
+  repeated sfixed32 packed_sfixed32 =  98 [packed = true];
+  repeated sfixed64 packed_sfixed64 =  99 [packed = true];
+  repeated    float packed_float    = 100 [packed = true];
+  repeated   double packed_double   = 101 [packed = true];
+  repeated     bool packed_bool     = 102 [packed = true];
+  repeated ForeignEnum packed_enum  = 103 [packed = true];
+}
+
+// Explicitly set packed to false
+message TestUnpackedTypes {
+  repeated    int32 repeated_int32    =  1 [packed = false];
+  repeated    int64 repeated_int64    =  2 [packed = false];
+  repeated   uint32 repeated_uint32   =  3 [packed = false];
+  repeated   uint64 repeated_uint64   =  4 [packed = false];
+  repeated   sint32 repeated_sint32   =  5 [packed = false];
+  repeated   sint64 repeated_sint64   =  6 [packed = false];
+  repeated  fixed32 repeated_fixed32  =  7 [packed = false];
+  repeated  fixed64 repeated_fixed64  =  8 [packed = false];
+  repeated sfixed32 repeated_sfixed32 =  9 [packed = false];
+  repeated sfixed64 repeated_sfixed64 = 10 [packed = false];
+  repeated    float repeated_float    = 11 [packed = false];
+  repeated   double repeated_double   = 12 [packed = false];
+  repeated     bool repeated_bool     = 13 [packed = false];
+  repeated TestAllTypes.NestedEnum repeated_nested_enum = 14 [packed = false];
+}
+
+// This proto includes a recusively nested message.
+message NestedTestAllTypes {
+  NestedTestAllTypes child = 1;
+  TestAllTypes payload = 2;
+}
+
+// Define these after TestAllTypes to make sure the compiler can handle
+// that.
+message ForeignMessage {
+  int32 c = 1;
+}
+
+enum ForeignEnum {
+  FOREIGN_ZERO = 0;
+  FOREIGN_FOO = 4;
+  FOREIGN_BAR = 5;
+  FOREIGN_BAZ = 6;
+}
+
+// TestEmptyMessage is used to test behavior of unknown fields.
+message TestEmptyMessage {
+}
+