diff --git a/cmake/README.md b/cmake/README.md
index ed30d24..89d00c1 100644
--- a/cmake/README.md
+++ b/cmake/README.md
@@ -343,23 +343,3 @@
 nevertheless.  So, we disable it.  Unfortunately, this warning will also be
 produced when compiling code which merely uses protocol buffers, meaning you
 may have to disable it in your code too.
-
-Cross-compiling
-===============
-
-When cross-compiling you will need to disable building the tests which are ON
-by default. You can do so by specifying the following flags when configuring
-your build: 
-
-	-Dprotobuf_BUILD_TESTS=OFF
-
-Alternatively you can compile (or download) 'protoc' for your host machine
-prior to configuring your target build. To specify an existing 'protoc' binary
-for your build, specify the following flag:
-
-	-DWITH_PROTOC=<path to your protoc binary>
-
-You can also save compilation time by disabling building 'protoc' for your
-target build:
-
-	-Dprotobuf_BUILD_PROTOC_BINARIES=OFF
diff --git a/conformance/failure_list_python.txt b/conformance/failure_list_python.txt
index f551227..3f7a811 100644
--- a/conformance/failure_list_python.txt
+++ b/conformance/failure_list_python.txt
@@ -28,4 +28,3 @@
 Required.Proto3.JsonInput.FloatFieldTooLarge
 Required.Proto3.JsonInput.FloatFieldTooSmall
 Required.Proto3.JsonInput.RepeatedFieldWrongElementTypeExpectingIntegersGotBool
-Required.Proto3.JsonInput.TimestampJsonInputLowercaseT
diff --git a/conformance/failure_list_python_cpp.txt b/conformance/failure_list_python_cpp.txt
index 59a969d..df16455 100644
--- a/conformance/failure_list_python_cpp.txt
+++ b/conformance/failure_list_python_cpp.txt
@@ -19,4 +19,3 @@
 Required.Proto3.JsonInput.FloatFieldTooLarge
 Required.Proto3.JsonInput.FloatFieldTooSmall
 Required.Proto3.JsonInput.RepeatedFieldWrongElementTypeExpectingIntegersGotBool
-Required.Proto3.JsonInput.TimestampJsonInputLowercaseT
diff --git a/js/message.js b/js/message.js
index c1736b3..f190894 100644
--- a/js/message.js
+++ b/js/message.js
@@ -417,7 +417,7 @@
  */
 jspb.Message.isArray_ = function(o) {
   return jspb.Message.ASSUME_LOCAL_ARRAYS ? o instanceof Array :
-                                            goog.isArray(o);
+                                            Array.isArray(o);
 };
 
 /**
@@ -1433,7 +1433,7 @@
   if (this.wrappers_) {
     for (var fieldNumber in this.wrappers_) {
       var val = this.wrappers_[fieldNumber];
-      if (goog.isArray(val)) {
+      if (Array.isArray(val)) {
         for (var i = 0; i < val.length; i++) {
           if (val[i]) {
             val[i].toArray();
@@ -1823,7 +1823,7 @@
  */
 jspb.Message.clone_ = function(obj) {
   var o;
-  if (goog.isArray(obj)) {
+  if (Array.isArray(obj)) {
     // Allocate array of correct size.
     var clonedArray = new Array(obj.length);
     // Use array iteration where possible because it is faster than for-in.
diff --git a/python/google/protobuf/internal/json_format_test.py b/python/google/protobuf/internal/json_format_test.py
index d828272..104b947 100755
--- a/python/google/protobuf/internal/json_format_test.py
+++ b/python/google/protobuf/internal/json_format_test.py
@@ -269,7 +269,6 @@
     }
     self.assertEqual(expected_dict, message_dict)
 
-
   def testExtensionSerializationJsonMatchesProto3Spec(self):
     """See go/proto3-json-spec for spec.
     """
@@ -295,7 +294,6 @@
                    '}}') % (ext1_text, ext2_text)
     self.assertEqual(json.loads(golden_text), json.loads(message_text))
 
-
   def testJsonEscapeString(self):
     message = json_format_proto3_pb2.TestMessage()
     if sys.version_info[0] < 3:
@@ -1036,6 +1034,15 @@
         OverflowError,
         'date value out of range',
         json_format.MessageToJson, message)
+    # Lower case t does not accept.
+    text = '{"value": "0001-01-01t00:00:00Z"}'
+    with self.assertRaises(json_format.ParseError) as e:
+      json_format.Parse(text, message)
+    self.assertEqual(
+        'Failed to parse value field: '
+        'time data \'0001-01-01t00:00:00\' does not match format '
+        '\'%Y-%m-%dT%H:%M:%S\', lowercase \'t\' is not accepted.',
+        str(e.exception))
 
   def testInvalidOneof(self):
     message = json_format_proto3_pb2.TestOneof()
diff --git a/python/google/protobuf/internal/well_known_types.py b/python/google/protobuf/internal/well_known_types.py
index 308fbfe..cb646a7 100644
--- a/python/google/protobuf/internal/well_known_types.py
+++ b/python/google/protobuf/internal/well_known_types.py
@@ -160,6 +160,10 @@
     else:
       second_value = time_value[:point_position]
       nano_value = time_value[point_position + 1:]
+    if 't' in second_value:
+      raise ValueError(
+          'time data \'{0}\' does not match format \'%Y-%m-%dT%H:%M:%S\', '
+          'lowercase \'t\' is not accepted'.format(second_value))
     date_object = datetime.strptime(second_value, _TIMESTAMPFOMAT)
     td = date_object - datetime(1970, 1, 1)
     seconds = td.seconds + td.days * _SECONDS_PER_DAY
diff --git a/src/google/protobuf/any.pb.h b/src/google/protobuf/any.pb.h
index cd1ae9f..08913bf 100644
--- a/src/google/protobuf/any.pb.h
+++ b/src/google/protobuf/any.pb.h
@@ -225,15 +225,6 @@
   std::string* mutable_type_url();
   std::string* release_type_url();
   void set_allocated_type_url(std::string* type_url);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_type_url();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_type_url(
-      std::string* type_url);
   private:
   const std::string& _internal_type_url() const;
   void _internal_set_type_url(const std::string& value);
@@ -250,15 +241,6 @@
   std::string* mutable_value();
   std::string* release_value();
   void set_allocated_value(std::string* value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_value(
-      std::string* value);
   private:
   const std::string& _internal_value() const;
   void _internal_set_value(const std::string& value);
@@ -350,25 +332,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Any.type_url)
 }
-inline std::string* Any::unsafe_arena_release_type_url() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Any.type_url)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return type_url_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Any::unsafe_arena_set_allocated_type_url(
-    std::string* type_url) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (type_url != nullptr) {
-    
-  } else {
-    
-  }
-  type_url_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      type_url, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Any.type_url)
-}
 
 // bytes value = 2;
 inline void Any::clear_value() {
@@ -431,25 +394,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Any.value)
 }
-inline std::string* Any::unsafe_arena_release_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Any.value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Any::unsafe_arena_set_allocated_value(
-    std::string* value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (value != nullptr) {
-    
-  } else {
-    
-  }
-  value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Any.value)
-}
 
 #ifdef __GNUC__
   #pragma GCC diagnostic pop
diff --git a/src/google/protobuf/api.pb.h b/src/google/protobuf/api.pb.h
index 2e307b4..3e199b6 100644
--- a/src/google/protobuf/api.pb.h
+++ b/src/google/protobuf/api.pb.h
@@ -261,15 +261,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -286,15 +277,6 @@
   std::string* mutable_version();
   std::string* release_version();
   void set_allocated_version(std::string* version);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_version();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_version(
-      std::string* version);
   private:
   const std::string& _internal_version() const;
   void _internal_set_version(const std::string& value);
@@ -496,15 +478,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -521,15 +494,6 @@
   std::string* mutable_request_type_url();
   std::string* release_request_type_url();
   void set_allocated_request_type_url(std::string* request_type_url);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_request_type_url();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_request_type_url(
-      std::string* request_type_url);
   private:
   const std::string& _internal_request_type_url() const;
   void _internal_set_request_type_url(const std::string& value);
@@ -546,15 +510,6 @@
   std::string* mutable_response_type_url();
   std::string* release_response_type_url();
   void set_allocated_response_type_url(std::string* response_type_url);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_response_type_url();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_response_type_url(
-      std::string* response_type_url);
   private:
   const std::string& _internal_response_type_url() const;
   void _internal_set_response_type_url(const std::string& value);
@@ -733,15 +688,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -758,15 +704,6 @@
   std::string* mutable_root();
   std::string* release_root();
   void set_allocated_root(std::string* root);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_root();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_root(
-      std::string* root);
   private:
   const std::string& _internal_root() const;
   void _internal_set_root(const std::string& value);
@@ -857,25 +794,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Api.name)
 }
-inline std::string* Api::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Api.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Api::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Api.name)
-}
 
 // repeated .google.protobuf.Method methods = 2;
 inline int Api::_internal_methods_size() const {
@@ -1013,25 +931,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Api.version)
 }
-inline std::string* Api::unsafe_arena_release_version() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Api.version)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return version_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Api::unsafe_arena_set_allocated_version(
-    std::string* version) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (version != nullptr) {
-    
-  } else {
-    
-  }
-  version_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      version, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Api.version)
-}
 
 // .google.protobuf.SourceContext source_context = 5;
 inline bool Api::_internal_has_source_context() const {
@@ -1234,25 +1133,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Method.name)
 }
-inline std::string* Method::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Method.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Method::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Method.name)
-}
 
 // string request_type_url = 2;
 inline void Method::clear_request_type_url() {
@@ -1315,25 +1195,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Method.request_type_url)
 }
-inline std::string* Method::unsafe_arena_release_request_type_url() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Method.request_type_url)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return request_type_url_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Method::unsafe_arena_set_allocated_request_type_url(
-    std::string* request_type_url) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (request_type_url != nullptr) {
-    
-  } else {
-    
-  }
-  request_type_url_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      request_type_url, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Method.request_type_url)
-}
 
 // bool request_streaming = 3;
 inline void Method::clear_request_streaming() {
@@ -1416,25 +1277,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Method.response_type_url)
 }
-inline std::string* Method::unsafe_arena_release_response_type_url() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Method.response_type_url)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return response_type_url_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Method::unsafe_arena_set_allocated_response_type_url(
-    std::string* response_type_url) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (response_type_url != nullptr) {
-    
-  } else {
-    
-  }
-  response_type_url_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      response_type_url, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Method.response_type_url)
-}
 
 // bool response_streaming = 5;
 inline void Method::clear_response_streaming() {
@@ -1577,25 +1419,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Mixin.name)
 }
-inline std::string* Mixin::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Mixin.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Mixin::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Mixin.name)
-}
 
 // string root = 2;
 inline void Mixin::clear_root() {
@@ -1658,25 +1481,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Mixin.root)
 }
-inline std::string* Mixin::unsafe_arena_release_root() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Mixin.root)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return root_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Mixin::unsafe_arena_set_allocated_root(
-    std::string* root) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (root != nullptr) {
-    
-  } else {
-    
-  }
-  root_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      root, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Mixin.root)
-}
 
 #ifdef __GNUC__
   #pragma GCC diagnostic pop
diff --git a/src/google/protobuf/arena_unittest.cc b/src/google/protobuf/arena_unittest.cc
index 5fa4b0c..8578420 100644
--- a/src/google/protobuf/arena_unittest.cc
+++ b/src/google/protobuf/arena_unittest.cc
@@ -858,23 +858,6 @@
   }
 }
 
-TEST(ArenaTest, UnsafeArenaReleaseAdd) {
-  // Use unsafe_arena_release() and unsafe_arena_set_allocated() to transfer an
-  // arena-allocated string from one message to another.
-  const char kContent[] = "Test content";
-
-  Arena arena;
-  TestAllTypes* message1 = Arena::CreateMessage<TestAllTypes>(&arena);
-  TestAllTypes* message2 = Arena::CreateMessage<TestAllTypes>(&arena);
-  std::string* arena_string = Arena::Create<std::string>(&arena);
-  *arena_string = kContent;
-
-  message1->unsafe_arena_set_allocated_optional_string(arena_string);
-  message2->unsafe_arena_set_allocated_optional_string(
-      message1->unsafe_arena_release_optional_string());
-  EXPECT_EQ(kContent, message2->optional_string());
-}
-
 TEST(ArenaTest, UnsafeArenaAddAllocated) {
   Arena arena;
   TestAllTypes* message = Arena::CreateMessage<TestAllTypes>(&arena);
@@ -885,43 +868,20 @@
   }
 }
 
-TEST(ArenaTest, UnsafeArenaRelease) {
-  Arena arena;
-  TestAllTypes* message = Arena::CreateMessage<TestAllTypes>(&arena);
-
-  std::string* s = new std::string("test string");
-  message->unsafe_arena_set_allocated_optional_string(s);
-  EXPECT_TRUE(message->has_optional_string());
-  EXPECT_EQ("test string", message->optional_string());
-  s = message->unsafe_arena_release_optional_string();
-  EXPECT_FALSE(message->has_optional_string());
-  delete s;
-
-  s = new std::string("test string");
-  message->unsafe_arena_set_allocated_oneof_string(s);
-  EXPECT_TRUE(message->has_oneof_string());
-  EXPECT_EQ("test string", message->oneof_string());
-  s = message->unsafe_arena_release_oneof_string();
-  EXPECT_FALSE(message->has_oneof_string());
-  delete s;
-}
-
 TEST(ArenaTest, OneofMerge) {
   Arena arena;
   TestAllTypes* message0 = Arena::CreateMessage<TestAllTypes>(&arena);
   TestAllTypes* message1 = Arena::CreateMessage<TestAllTypes>(&arena);
 
-  message0->unsafe_arena_set_allocated_oneof_string(new std::string("x"));
+  message0->set_oneof_string("x");
   ASSERT_TRUE(message0->has_oneof_string());
-  message1->unsafe_arena_set_allocated_oneof_string(new std::string("y"));
+  message1->set_oneof_string("y");
   ASSERT_TRUE(message1->has_oneof_string());
   EXPECT_EQ("x", message0->oneof_string());
   EXPECT_EQ("y", message1->oneof_string());
   message0->MergeFrom(*message1);
   EXPECT_EQ("y", message0->oneof_string());
   EXPECT_EQ("y", message1->oneof_string());
-  delete message0->unsafe_arena_release_oneof_string();
-  delete message1->unsafe_arena_release_oneof_string();
 }
 
 TEST(ArenaTest, ArenaOneofReflection) {
@@ -1345,19 +1305,6 @@
   }
 }
 
-TEST(ArenaTest, UnsafeSetAllocatedOnArena) {
-  Arena arena;
-  TestAllTypes* message = Arena::CreateMessage<TestAllTypes>(&arena);
-  EXPECT_FALSE(message->has_optional_string());
-
-  std::string owned_string = "test with long enough content to heap-allocate";
-  message->unsafe_arena_set_allocated_optional_string(&owned_string);
-  EXPECT_TRUE(message->has_optional_string());
-
-  message->unsafe_arena_set_allocated_optional_string(NULL);
-  EXPECT_FALSE(message->has_optional_string());
-}
-
 // A helper utility class to only contain static hook functions, some
 // counters to be used to verify the counters have been called and a cookie
 // value to be verified.
diff --git a/src/google/protobuf/compiler/code_generator.h b/src/google/protobuf/compiler/code_generator.h
index 1bc8dfc..21131d5 100644
--- a/src/google/protobuf/compiler/code_generator.h
+++ b/src/google/protobuf/compiler/code_generator.h
@@ -110,7 +110,7 @@
   // Implement this to indicate what features this code generator supports.
   // This should be a bitwise OR of features from the Features enum in
   // plugin.proto.
-  virtual uint64 GetSupportedFeatures() const { return 0; }
+  virtual uint64_t GetSupportedFeatures() const { return 0; }
 
   // This is no longer used, but this class is part of the opensource protobuf
   // library, so it has to remain to keep vtables the same for the current
diff --git a/src/google/protobuf/compiler/cpp/cpp_generator.h b/src/google/protobuf/compiler/cpp/cpp_generator.h
index 85a5aab..97e848d 100644
--- a/src/google/protobuf/compiler/cpp/cpp_generator.h
+++ b/src/google/protobuf/compiler/cpp/cpp_generator.h
@@ -84,7 +84,7 @@
                 GeneratorContext* generator_context,
                 std::string* error) const override;
 
-  uint64 GetSupportedFeatures() const override {
+  uint64_t GetSupportedFeatures() const override {
     // We don't fully support this yet, but this is needed to unblock the tests,
     // and we will have full support before the experimental flag is removed.
     return FEATURE_PROTO3_OPTIONAL;
diff --git a/src/google/protobuf/compiler/cpp/cpp_string_field.cc b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
index ca365e7..5cf82f6 100644
--- a/src/google/protobuf/compiler/cpp/cpp_string_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
@@ -179,23 +179,6 @@
       "$deprecated_attr$void ${1$set_allocated_$name$$}$(std::string* "
       "$name$);\n",
       descriptor_);
-  if (options_.opensource_runtime) {
-    if (SupportsArenas(descriptor_)) {
-      format(
-          "$GOOGLE_PROTOBUF$_RUNTIME_DEPRECATED(\"The unsafe_arena_ accessors "
-          "for\"\n"
-          "\"    string fields are deprecated and will be removed in a\"\n"
-          "\"    future release.\")\n"
-          "std::string* ${1$unsafe_arena_release_$name$$}$();\n"
-          "$GOOGLE_PROTOBUF$_RUNTIME_DEPRECATED(\"The unsafe_arena_ accessors "
-          "for\"\n"
-          "\"    string fields are deprecated and will be removed in a\"\n"
-          "\"    future release.\")\n"
-          "void ${1$unsafe_arena_set_allocated_$name$$}$(\n"
-          "    std::string* $name$);\n",
-          descriptor_);
-    }
-  }
   format(
       "private:\n"
       "const std::string& _internal_$name$() const;\n"
@@ -307,32 +290,6 @@
         "      GetArena());\n"
         "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
         "}\n");
-    if (options_.opensource_runtime) {
-      format(
-          "inline std::string* $classname$::unsafe_arena_release_$name$() {\n"
-          "$annotate_accessor$"
-          "  // "
-          "@@protoc_insertion_point(field_unsafe_arena_release:$full_name$)\n"
-          "  $DCHK$(GetArena() != nullptr);\n"
-          "  $clear_hasbit$\n"
-          "  return $name$_.UnsafeArenaRelease($default_variable$,\n"
-          "      GetArena());\n"
-          "}\n"
-          "inline void $classname$::unsafe_arena_set_allocated_$name$(\n"
-          "$annotate_accessor$"
-          "    std::string* $name$) {\n"
-          "  $DCHK$(GetArena() != nullptr);\n"
-          "  if ($name$ != nullptr) {\n"
-          "    $set_hasbit$\n"
-          "  } else {\n"
-          "    $clear_hasbit$\n"
-          "  }\n"
-          "  $name$_.UnsafeArenaSetAllocated($default_variable$,\n"
-          "      $name$, GetArena());\n"
-          "  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:"
-          "$full_name$)\n"
-          "}\n");
-    }
   } else {
     // No-arena case.
     format(
@@ -761,38 +718,6 @@
         "  }\n"
         "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
         "}\n");
-    if (options_.opensource_runtime) {
-      format(
-          "inline std::string* $classname$::unsafe_arena_release_$name$() {\n"
-          "$annotate_accessor$"
-          "  // "
-          "@@protoc_insertion_point(field_unsafe_arena_release:$full_name$)\n"
-          "  $DCHK$(GetArena() != nullptr);\n"
-          "  if (_internal_has_$name$()) {\n"
-          "    clear_has_$oneof_name$();\n"
-          "    return $field_member$.UnsafeArenaRelease(\n"
-          "        $default_variable$, GetArena());\n"
-          "  } else {\n"
-          "    return nullptr;\n"
-          "  }\n"
-          "}\n"
-          "inline void $classname$::unsafe_arena_set_allocated_$name$("
-          "std::string* $name$) {\n"
-          "$annotate_accessor$"
-          "  $DCHK$(GetArena() != nullptr);\n"
-          "  if (!_internal_has_$name$()) {\n"
-          "    $field_member$.UnsafeSetDefault($default_variable$);\n"
-          "  }\n"
-          "  clear_$oneof_name$();\n"
-          "  if ($name$) {\n"
-          "    set_has_$name$();\n"
-          "    $field_member$.UnsafeArenaSetAllocated($default_variable$, "
-          "$name$, GetArena());\n"
-          "  }\n"
-          "  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:"
-          "$full_name$)\n"
-          "}\n");
-    }
   } else {
     // No-arena case.
     format(
diff --git a/src/google/protobuf/compiler/java/java_generator.cc b/src/google/protobuf/compiler/java/java_generator.cc
index 11b04b8..29ae2cf 100644
--- a/src/google/protobuf/compiler/java/java_generator.cc
+++ b/src/google/protobuf/compiler/java/java_generator.cc
@@ -58,7 +58,7 @@
 JavaGenerator::JavaGenerator() {}
 JavaGenerator::~JavaGenerator() {}
 
-uint64 JavaGenerator::GetSupportedFeatures() const {
+uint64_t JavaGenerator::GetSupportedFeatures() const {
   return CodeGenerator::Feature::FEATURE_PROTO3_OPTIONAL;
 }
 
diff --git a/src/google/protobuf/compiler/java/java_generator.h b/src/google/protobuf/compiler/java/java_generator.h
index a4e1708..6315e7c 100644
--- a/src/google/protobuf/compiler/java/java_generator.h
+++ b/src/google/protobuf/compiler/java/java_generator.h
@@ -60,7 +60,7 @@
   bool Generate(const FileDescriptor* file, const std::string& parameter,
                 GeneratorContext* context, std::string* error) const override;
 
-  uint64 GetSupportedFeatures() const override;
+  uint64_t GetSupportedFeatures() const override;
 
  private:
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(JavaGenerator);
diff --git a/src/google/protobuf/compiler/mock_code_generator.cc b/src/google/protobuf/compiler/mock_code_generator.cc
index 8b82901..0b85056 100644
--- a/src/google/protobuf/compiler/mock_code_generator.cc
+++ b/src/google/protobuf/compiler/mock_code_generator.cc
@@ -87,7 +87,7 @@
 
 MockCodeGenerator::~MockCodeGenerator() {}
 
-uint64 MockCodeGenerator::GetSupportedFeatures() const {
+uint64_t MockCodeGenerator::GetSupportedFeatures() const {
   uint64 all_features = CodeGenerator::FEATURE_PROTO3_OPTIONAL;
   return all_features & ~suppressed_features_;
 }
diff --git a/src/google/protobuf/compiler/mock_code_generator.h b/src/google/protobuf/compiler/mock_code_generator.h
index 70a840e..9a72258 100644
--- a/src/google/protobuf/compiler/mock_code_generator.h
+++ b/src/google/protobuf/compiler/mock_code_generator.h
@@ -109,7 +109,7 @@
   bool Generate(const FileDescriptor* file, const std::string& parameter,
                 GeneratorContext* context, std::string* error) const override;
 
-  uint64 GetSupportedFeatures() const override;
+  uint64_t GetSupportedFeatures() const override;
   void SuppressFeatures(uint64 features);
 
  private:
diff --git a/src/google/protobuf/compiler/plugin.pb.h b/src/google/protobuf/compiler/plugin.pb.h
index 2ada7cb..f4a0449 100644
--- a/src/google/protobuf/compiler/plugin.pb.h
+++ b/src/google/protobuf/compiler/plugin.pb.h
@@ -251,15 +251,6 @@
   std::string* mutable_suffix();
   std::string* release_suffix();
   void set_allocated_suffix(std::string* suffix);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_suffix();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_suffix(
-      std::string* suffix);
   private:
   const std::string& _internal_suffix() const;
   void _internal_set_suffix(const std::string& value);
@@ -503,15 +494,6 @@
   std::string* mutable_parameter();
   std::string* release_parameter();
   void set_allocated_parameter(std::string* parameter);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_parameter();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_parameter(
-      std::string* parameter);
   private:
   const std::string& _internal_parameter() const;
   void _internal_set_parameter(const std::string& value);
@@ -691,15 +673,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -720,15 +693,6 @@
   std::string* mutable_insertion_point();
   std::string* release_insertion_point();
   void set_allocated_insertion_point(std::string* insertion_point);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_insertion_point();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_insertion_point(
-      std::string* insertion_point);
   private:
   const std::string& _internal_insertion_point() const;
   void _internal_set_insertion_point(const std::string& value);
@@ -749,15 +713,6 @@
   std::string* mutable_content();
   std::string* release_content();
   void set_allocated_content(std::string* content);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_content();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_content(
-      std::string* content);
   private:
   const std::string& _internal_content() const;
   void _internal_set_content(const std::string& value);
@@ -968,15 +923,6 @@
   std::string* mutable_error();
   std::string* release_error();
   void set_allocated_error(std::string* error);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_error();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_error(
-      std::string* error);
   private:
   const std::string& _internal_error() const;
   void _internal_set_error(const std::string& value);
@@ -1178,25 +1124,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.Version.suffix)
 }
-inline std::string* Version::unsafe_arena_release_suffix() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.compiler.Version.suffix)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return suffix_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Version::unsafe_arena_set_allocated_suffix(
-    std::string* suffix) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (suffix != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  suffix_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      suffix, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.compiler.Version.suffix)
-}
 
 // -------------------------------------------------------------------
 
@@ -1349,25 +1276,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorRequest.parameter)
 }
-inline std::string* CodeGeneratorRequest::unsafe_arena_release_parameter() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.compiler.CodeGeneratorRequest.parameter)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return parameter_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void CodeGeneratorRequest::unsafe_arena_set_allocated_parameter(
-    std::string* parameter) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (parameter != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  parameter_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      parameter, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.compiler.CodeGeneratorRequest.parameter)
-}
 
 // repeated .google.protobuf.FileDescriptorProto proto_file = 15;
 inline int CodeGeneratorRequest::_internal_proto_file_size() const {
@@ -1565,25 +1473,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.name)
 }
-inline std::string* CodeGeneratorResponse_File::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.compiler.CodeGeneratorResponse.File.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void CodeGeneratorResponse_File::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.name)
-}
 
 // optional string insertion_point = 2;
 inline bool CodeGeneratorResponse_File::_internal_has_insertion_point() const {
@@ -1658,25 +1547,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.insertion_point)
 }
-inline std::string* CodeGeneratorResponse_File::unsafe_arena_release_insertion_point() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.compiler.CodeGeneratorResponse.File.insertion_point)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return insertion_point_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void CodeGeneratorResponse_File::unsafe_arena_set_allocated_insertion_point(
-    std::string* insertion_point) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (insertion_point != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  insertion_point_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      insertion_point, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.insertion_point)
-}
 
 // optional string content = 15;
 inline bool CodeGeneratorResponse_File::_internal_has_content() const {
@@ -1751,25 +1621,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.content)
 }
-inline std::string* CodeGeneratorResponse_File::unsafe_arena_release_content() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.compiler.CodeGeneratorResponse.File.content)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000004u;
-  return content_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void CodeGeneratorResponse_File::unsafe_arena_set_allocated_content(
-    std::string* content) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (content != nullptr) {
-    _has_bits_[0] |= 0x00000004u;
-  } else {
-    _has_bits_[0] &= ~0x00000004u;
-  }
-  content_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      content, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.content)
-}
 
 // -------------------------------------------------------------------
 
@@ -1848,25 +1699,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.error)
 }
-inline std::string* CodeGeneratorResponse::unsafe_arena_release_error() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.compiler.CodeGeneratorResponse.error)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return error_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void CodeGeneratorResponse::unsafe_arena_set_allocated_error(
-    std::string* error) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (error != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  error_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      error, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.error)
-}
 
 // optional uint64 supported_features = 2;
 inline bool CodeGeneratorResponse::_internal_has_supported_features() const {
diff --git a/src/google/protobuf/compiler/python/python_generator.cc b/src/google/protobuf/compiler/python/python_generator.cc
index 88804bd..a95b37f 100644
--- a/src/google/protobuf/compiler/python/python_generator.cc
+++ b/src/google/protobuf/compiler/python/python_generator.cc
@@ -301,7 +301,7 @@
 
 Generator::~Generator() {}
 
-uint64 Generator::GetSupportedFeatures() const {
+uint64_t Generator::GetSupportedFeatures() const {
   return CodeGenerator::Feature::FEATURE_PROTO3_OPTIONAL;
 }
 
diff --git a/src/google/protobuf/compiler/python/python_generator.h b/src/google/protobuf/compiler/python/python_generator.h
index fb1aee1..ed1c995 100644
--- a/src/google/protobuf/compiler/python/python_generator.h
+++ b/src/google/protobuf/compiler/python/python_generator.h
@@ -73,7 +73,7 @@
                 GeneratorContext* generator_context,
                 std::string* error) const override;
 
-  uint64 GetSupportedFeatures() const override;
+  uint64_t GetSupportedFeatures() const override;
 
  private:
   void PrintImports() const;
diff --git a/src/google/protobuf/descriptor.cc b/src/google/protobuf/descriptor.cc
index 5001222..9a448ff 100644
--- a/src/google/protobuf/descriptor.cc
+++ b/src/google/protobuf/descriptor.cc
@@ -434,14 +434,14 @@
 
 const Symbol kNullSymbol;
 
-typedef HASH_MAP<const char*, Symbol, HASH_FXN<const char*>, streq>
+typedef HASH_MAP<StringPiece, Symbol, HASH_FXN<StringPiece>>
     SymbolsByNameMap;
 
 typedef HASH_MAP<PointerStringPair, Symbol, PointerStringPairHash>
     SymbolsByParentMap;
 
-typedef HASH_MAP<const char*, const FileDescriptor*, HASH_FXN<const char*>,
-                 streq>
+typedef HASH_MAP<StringPiece, const FileDescriptor*,
+                 HASH_FXN<StringPiece>>
     FilesByNameMap;
 
 typedef HASH_MAP<PointerStringPair, const FieldDescriptor*,
@@ -576,16 +576,16 @@
 
   // Find symbols.  This returns a null Symbol (symbol.IsNull() is true)
   // if not found.
-  inline Symbol FindSymbol(const std::string& key) const;
+  inline Symbol FindSymbol(StringPiece key) const;
 
   // This implements the body of DescriptorPool::Find*ByName().  It should
   // really be a private method of DescriptorPool, but that would require
   // declaring Symbol in descriptor.h, which would drag all kinds of other
   // stuff into the header.  Yay C++.
-  Symbol FindByNameHelper(const DescriptorPool* pool, const std::string& name);
+  Symbol FindByNameHelper(const DescriptorPool* pool, StringPiece name);
 
   // These return nullptr if not found.
-  inline const FileDescriptor* FindFile(const std::string& key) const;
+  inline const FileDescriptor* FindFile(StringPiece key) const;
   inline const FieldDescriptor* FindExtension(const Descriptor* extendee,
                                               int number) const;
   inline void FindAllExtensions(const Descriptor* extendee,
@@ -619,7 +619,7 @@
 
   // Allocate a string which will be destroyed when the pool is destroyed.
   // The string is initialized to the given value for convenience.
-  std::string* AllocateString(const std::string& value);
+  std::string* AllocateString(StringPiece value);
 
   // Allocate empty string which will be destroyed when the pool is destroyed.
   std::string* AllocateEmptyString();
@@ -715,9 +715,9 @@
   inline const FieldDescriptor* FindFieldByNumber(const Descriptor* parent,
                                                   int number) const;
   inline const FieldDescriptor* FindFieldByLowercaseName(
-      const void* parent, const std::string& lowercase_name) const;
+      const void* parent, StringPiece lowercase_name) const;
   inline const FieldDescriptor* FindFieldByCamelcaseName(
-      const void* parent, const std::string& camelcase_name) const;
+      const void* parent, StringPiece camelcase_name) const;
   inline const EnumValueDescriptor* FindEnumValueByNumber(
       const EnumDescriptor* parent, int number) const;
   // This creates a new EnumValueDescriptor if not found, in a thread-safe way.
@@ -884,8 +884,8 @@
 
 // -------------------------------------------------------------------
 
-inline Symbol DescriptorPool::Tables::FindSymbol(const std::string& key) const {
-  const Symbol* result = FindOrNull(symbols_by_name_, key.c_str());
+inline Symbol DescriptorPool::Tables::FindSymbol(StringPiece key) const {
+  const Symbol* result = FindOrNull(symbols_by_name_, key);
   if (result == nullptr) {
     return kNullSymbol;
   } else {
@@ -912,7 +912,7 @@
 }
 
 Symbol DescriptorPool::Tables::FindByNameHelper(const DescriptorPool* pool,
-                                                const std::string& name) {
+                                                StringPiece name) {
   if (pool->mutex_ != nullptr) {
     // Fast path: the Symbol is already cached.  This is just a hash lookup.
     ReaderMutexLock lock(pool->mutex_);
@@ -944,8 +944,8 @@
 }
 
 inline const FileDescriptor* DescriptorPool::Tables::FindFile(
-    const std::string& key) const {
-  return FindPtrOrNull(files_by_name_, key.c_str());
+    StringPiece key) const {
+  return FindPtrOrNull(files_by_name_, key);
 }
 
 inline const FieldDescriptor* FileDescriptorTables::FindFieldByNumber(
@@ -982,12 +982,12 @@
 }
 
 inline const FieldDescriptor* FileDescriptorTables::FindFieldByLowercaseName(
-    const void* parent, const std::string& lowercase_name) const {
+    const void* parent, StringPiece lowercase_name) const {
   internal::call_once(
       fields_by_lowercase_name_once_,
       &FileDescriptorTables::FieldsByLowercaseNamesLazyInitStatic, this);
   return FindPtrOrNull(fields_by_lowercase_name_,
-                            PointerStringPair(parent, lowercase_name.c_str()));
+                            PointerStringPair(parent, lowercase_name));
 }
 
 void FileDescriptorTables::FieldsByCamelcaseNamesLazyInitStatic(
@@ -1006,12 +1006,12 @@
 }
 
 inline const FieldDescriptor* FileDescriptorTables::FindFieldByCamelcaseName(
-    const void* parent, const std::string& camelcase_name) const {
+    const void* parent, StringPiece camelcase_name) const {
   internal::call_once(
       fields_by_camelcase_name_once_,
       FileDescriptorTables::FieldsByCamelcaseNamesLazyInitStatic, this);
   return FindPtrOrNull(fields_by_camelcase_name_,
-                            PointerStringPair(parent, camelcase_name.c_str()));
+                            PointerStringPair(parent, camelcase_name));
 }
 
 inline const EnumValueDescriptor* FileDescriptorTables::FindEnumValueByNumber(
@@ -1181,7 +1181,7 @@
   return reinterpret_cast<Type*>(AllocateBytes(sizeof(Type) * count));
 }
 
-std::string* DescriptorPool::Tables::AllocateString(const std::string& value) {
+std::string* DescriptorPool::Tables::AllocateString(StringPiece value) {
   std::string* result = new std::string(value);
   strings_.emplace_back(result);
   return result;
@@ -1293,16 +1293,16 @@
   enforce_dependencies_ = false;
 }
 
-void DescriptorPool::AddUnusedImportTrackFile(const std::string& file_name,
+void DescriptorPool::AddUnusedImportTrackFile(ConstStringParam file_name,
                                               bool is_error) {
-  unused_import_track_files_[file_name] = is_error;
+  unused_import_track_files_[std::string(file_name)] = is_error;
 }
 
 void DescriptorPool::ClearUnusedImportTrackFiles() {
   unused_import_track_files_.clear();
 }
 
-bool DescriptorPool::InternalIsFileLoaded(const std::string& filename) const {
+bool DescriptorPool::InternalIsFileLoaded(ConstStringParam filename) const {
   MutexLockMaybe lock(mutex_);
   return tables_->FindFile(filename) != nullptr;
 }
@@ -1379,7 +1379,7 @@
 //   there's nothing more important to do (read: never).
 
 const FileDescriptor* DescriptorPool::FindFileByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   MutexLockMaybe lock(mutex_);
   if (fallback_database_ != nullptr) {
     tables_->known_bad_symbols_.clear();
@@ -1399,7 +1399,7 @@
 }
 
 const FileDescriptor* DescriptorPool::FindFileContainingSymbol(
-    const std::string& symbol_name) const {
+    ConstStringParam symbol_name) const {
   MutexLockMaybe lock(mutex_);
   if (fallback_database_ != nullptr) {
     tables_->known_bad_symbols_.clear();
@@ -1420,13 +1420,13 @@
 }
 
 const Descriptor* DescriptorPool::FindMessageTypeByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   return (result.type == Symbol::MESSAGE) ? result.descriptor : nullptr;
 }
 
 const FieldDescriptor* DescriptorPool::FindFieldByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   if (result.type == Symbol::FIELD &&
       !result.field_descriptor->is_extension()) {
@@ -1437,7 +1437,7 @@
 }
 
 const FieldDescriptor* DescriptorPool::FindExtensionByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   if (result.type == Symbol::FIELD && result.field_descriptor->is_extension()) {
     return result.field_descriptor;
@@ -1447,32 +1447,32 @@
 }
 
 const OneofDescriptor* DescriptorPool::FindOneofByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   return (result.type == Symbol::ONEOF) ? result.oneof_descriptor : nullptr;
 }
 
 const EnumDescriptor* DescriptorPool::FindEnumTypeByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   return (result.type == Symbol::ENUM) ? result.enum_descriptor : nullptr;
 }
 
 const EnumValueDescriptor* DescriptorPool::FindEnumValueByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   return (result.type == Symbol::ENUM_VALUE) ? result.enum_value_descriptor
                                              : nullptr;
 }
 
 const ServiceDescriptor* DescriptorPool::FindServiceByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   return (result.type == Symbol::SERVICE) ? result.service_descriptor : nullptr;
 }
 
 const MethodDescriptor* DescriptorPool::FindMethodByName(
-    const std::string& name) const {
+    ConstStringParam name) const {
   Symbol result = tables_->FindByNameHelper(this, name);
   return (result.type == Symbol::METHOD) ? result.method_descriptor : nullptr;
 }
@@ -1529,7 +1529,7 @@
 }
 
 const FieldDescriptor* DescriptorPool::FindExtensionByPrintableName(
-    const Descriptor* extendee, const std::string& printable_name) const {
+    const Descriptor* extendee, ConstStringParam printable_name) const {
   if (extendee->extension_range_count() == 0) return nullptr;
   const FieldDescriptor* result = FindExtensionByName(printable_name);
   if (result != nullptr && result->containing_type() == extendee) {
@@ -1600,7 +1600,7 @@
 }
 
 const FieldDescriptor* Descriptor::FindFieldByLowercaseName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   const FieldDescriptor* result =
       file()->tables_->FindFieldByLowercaseName(this, key);
   if (result == nullptr || result->is_extension()) {
@@ -1611,7 +1611,7 @@
 }
 
 const FieldDescriptor* Descriptor::FindFieldByCamelcaseName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   const FieldDescriptor* result =
       file()->tables_->FindFieldByCamelcaseName(this, key);
   if (result == nullptr || result->is_extension()) {
@@ -1621,8 +1621,7 @@
   }
 }
 
-const FieldDescriptor* Descriptor::FindFieldByName(
-    const std::string& key) const {
+const FieldDescriptor* Descriptor::FindFieldByName(ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::FIELD);
   if (!result.IsNull() && !result.field_descriptor->is_extension()) {
@@ -1632,8 +1631,7 @@
   }
 }
 
-const OneofDescriptor* Descriptor::FindOneofByName(
-    const std::string& key) const {
+const OneofDescriptor* Descriptor::FindOneofByName(ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::ONEOF);
   if (!result.IsNull()) {
@@ -1644,7 +1642,7 @@
 }
 
 const FieldDescriptor* Descriptor::FindExtensionByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::FIELD);
   if (!result.IsNull() && result.field_descriptor->is_extension()) {
@@ -1655,7 +1653,7 @@
 }
 
 const FieldDescriptor* Descriptor::FindExtensionByLowercaseName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   const FieldDescriptor* result =
       file()->tables_->FindFieldByLowercaseName(this, key);
   if (result == nullptr || !result->is_extension()) {
@@ -1666,7 +1664,7 @@
 }
 
 const FieldDescriptor* Descriptor::FindExtensionByCamelcaseName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   const FieldDescriptor* result =
       file()->tables_->FindFieldByCamelcaseName(this, key);
   if (result == nullptr || !result->is_extension()) {
@@ -1676,8 +1674,7 @@
   }
 }
 
-const Descriptor* Descriptor::FindNestedTypeByName(
-    const std::string& key) const {
+const Descriptor* Descriptor::FindNestedTypeByName(ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::MESSAGE);
   if (!result.IsNull()) {
@@ -1688,7 +1685,7 @@
 }
 
 const EnumDescriptor* Descriptor::FindEnumTypeByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::ENUM);
   if (!result.IsNull()) {
@@ -1699,7 +1696,7 @@
 }
 
 const EnumValueDescriptor* Descriptor::FindEnumValueByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::ENUM_VALUE);
   if (!result.IsNull()) {
@@ -1742,7 +1739,7 @@
 }
 
 const MethodDescriptor* ServiceDescriptor::FindMethodByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result =
       file()->tables_->FindNestedSymbolOfType(this, key, Symbol::METHOD);
   if (!result.IsNull()) {
@@ -1753,7 +1750,7 @@
 }
 
 const Descriptor* FileDescriptor::FindMessageTypeByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result = tables_->FindNestedSymbolOfType(this, key, Symbol::MESSAGE);
   if (!result.IsNull()) {
     return result.descriptor;
@@ -1763,7 +1760,7 @@
 }
 
 const EnumDescriptor* FileDescriptor::FindEnumTypeByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result = tables_->FindNestedSymbolOfType(this, key, Symbol::ENUM);
   if (!result.IsNull()) {
     return result.enum_descriptor;
@@ -1773,7 +1770,7 @@
 }
 
 const EnumValueDescriptor* FileDescriptor::FindEnumValueByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result =
       tables_->FindNestedSymbolOfType(this, key, Symbol::ENUM_VALUE);
   if (!result.IsNull()) {
@@ -1784,7 +1781,7 @@
 }
 
 const ServiceDescriptor* FileDescriptor::FindServiceByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result = tables_->FindNestedSymbolOfType(this, key, Symbol::SERVICE);
   if (!result.IsNull()) {
     return result.service_descriptor;
@@ -1794,7 +1791,7 @@
 }
 
 const FieldDescriptor* FileDescriptor::FindExtensionByName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   Symbol result = tables_->FindNestedSymbolOfType(this, key, Symbol::FIELD);
   if (!result.IsNull() && result.field_descriptor->is_extension()) {
     return result.field_descriptor;
@@ -1804,7 +1801,7 @@
 }
 
 const FieldDescriptor* FileDescriptor::FindExtensionByLowercaseName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   const FieldDescriptor* result = tables_->FindFieldByLowercaseName(this, key);
   if (result == nullptr || !result->is_extension()) {
     return nullptr;
@@ -1814,7 +1811,7 @@
 }
 
 const FieldDescriptor* FileDescriptor::FindExtensionByCamelcaseName(
-    const std::string& key) const {
+    ConstStringParam key) const {
   const FieldDescriptor* result = tables_->FindFieldByCamelcaseName(this, key);
   if (result == nullptr || !result->is_extension()) {
     return nullptr;
@@ -1871,22 +1868,23 @@
 // -------------------------------------------------------------------
 
 bool DescriptorPool::TryFindFileInFallbackDatabase(
-    const std::string& name) const {
+    StringPiece name) const {
   if (fallback_database_ == nullptr) return false;
 
-  if (tables_->known_bad_files_.count(name) > 0) return false;
+  auto name_string = std::string(name);
+  if (tables_->known_bad_files_.count(name_string) > 0) return false;
 
   FileDescriptorProto file_proto;
-  if (!fallback_database_->FindFileByName(name, &file_proto) ||
+  if (!fallback_database_->FindFileByName(name_string, &file_proto) ||
       BuildFileFromDatabase(file_proto) == nullptr) {
-    tables_->known_bad_files_.insert(name);
+    tables_->known_bad_files_.insert(std::move(name_string));
     return false;
   }
   return true;
 }
 
-bool DescriptorPool::IsSubSymbolOfBuiltType(const std::string& name) const {
-  std::string prefix = name;
+bool DescriptorPool::IsSubSymbolOfBuiltType(StringPiece name) const {
+  auto prefix = std::string(name);
   for (;;) {
     std::string::size_type dot_pos = prefix.find_last_of('.');
     if (dot_pos == std::string::npos) {
@@ -1908,10 +1906,11 @@
 }
 
 bool DescriptorPool::TryFindSymbolInFallbackDatabase(
-    const std::string& name) const {
+    StringPiece name) const {
   if (fallback_database_ == nullptr) return false;
 
-  if (tables_->known_bad_symbols_.count(name) > 0) return false;
+  auto name_string = std::string(name);
+  if (tables_->known_bad_symbols_.count(name_string) > 0) return false;
 
   FileDescriptorProto file_proto;
   if (  // We skip looking in the fallback database if the name is a sub-symbol
@@ -1933,7 +1932,7 @@
       IsSubSymbolOfBuiltType(name)
 
       // Look up file containing this symbol in fallback database.
-      || !fallback_database_->FindFileContainingSymbol(name, &file_proto)
+      || !fallback_database_->FindFileContainingSymbol(name_string, &file_proto)
 
       // Check if we've already built this file. If so, it apparently doesn't
       // contain the symbol we're looking for.  Some DescriptorDatabases
@@ -1942,7 +1941,7 @@
 
       // Build the file.
       || BuildFileFromDatabase(file_proto) == nullptr) {
-    tables_->known_bad_symbols_.insert(name);
+    tables_->known_bad_symbols_.insert(std::move(name_string));
     return false;
   }
 
@@ -3864,7 +3863,7 @@
   return result;
 }
 
-static bool ValidateQualifiedName(const std::string& name) {
+static bool ValidateQualifiedName(StringPiece name) {
   bool last_was_period = false;
 
   for (int i = 0; i < name.size(); i++) {
@@ -3884,14 +3883,14 @@
   return !name.empty() && !last_was_period;
 }
 
-Symbol DescriptorPool::NewPlaceholder(const std::string& name,
+Symbol DescriptorPool::NewPlaceholder(StringPiece name,
                                       PlaceholderType placeholder_type) const {
   MutexLockMaybe lock(mutex_);
   return NewPlaceholderWithMutexHeld(name, placeholder_type);
 }
 
 Symbol DescriptorPool::NewPlaceholderWithMutexHeld(
-    const std::string& name, PlaceholderType placeholder_type) const {
+    StringPiece name, PlaceholderType placeholder_type) const {
   if (mutex_) {
     mutex_->AssertHeld();
   }
@@ -3989,13 +3988,13 @@
 }
 
 FileDescriptor* DescriptorPool::NewPlaceholderFile(
-    const std::string& name) const {
+    StringPiece name) const {
   MutexLockMaybe lock(mutex_);
   return NewPlaceholderFileWithMutexHeld(name);
 }
 
 FileDescriptor* DescriptorPool::NewPlaceholderFileWithMutexHeld(
-    const std::string& name) const {
+    StringPiece name) const {
   if (mutex_) {
     mutex_->AssertHeld();
   }
@@ -7269,9 +7268,9 @@
   }
 }
 
-Symbol DescriptorPool::CrossLinkOnDemandHelper(const std::string& name,
+Symbol DescriptorPool::CrossLinkOnDemandHelper(StringPiece name,
                                                bool expecting_enum) const {
-  std::string lookup_name = name;
+  auto lookup_name = std::string(name);
   if (!lookup_name.empty() && lookup_name[0] == '.') {
     lookup_name = lookup_name.substr(1);
   }
@@ -7399,7 +7398,7 @@
   descriptor_ = descriptor;
 }
 
-void LazyDescriptor::SetLazy(const std::string& name,
+void LazyDescriptor::SetLazy(StringPiece name,
                              const FileDescriptor* file) {
   // verify Init() has been called and Set hasn't been called yet.
   GOOGLE_CHECK(!descriptor_);
diff --git a/src/google/protobuf/descriptor.h b/src/google/protobuf/descriptor.h
index f0d2064..078f24a 100644
--- a/src/google/protobuf/descriptor.h
+++ b/src/google/protobuf/descriptor.h
@@ -203,7 +203,7 @@
   // build time if the symbol wasn't found and building of the file containing
   // that type is delayed because lazily_build_dependencies_ is set on the pool.
   // Should not be called after Set() has been called.
-  void SetLazy(const std::string& name, const FileDescriptor* file);
+  void SetLazy(StringPiece name, const FileDescriptor* file);
 
   // Returns the current value of the descriptor, thread-safe. If SetLazy(...)
   // has been called, will do a one-time cross link of the type specified,
@@ -321,20 +321,20 @@
   // exists.
   const FieldDescriptor* FindFieldByNumber(int number) const;
   // Looks up a field by name.  Returns nullptr if no such field exists.
-  const FieldDescriptor* FindFieldByName(const std::string& name) const;
+  const FieldDescriptor* FindFieldByName(ConstStringParam name) const;
 
   // Looks up a field by lowercased name (as returned by lowercase_name()).
   // This lookup may be ambiguous if multiple field names differ only by case,
   // in which case the field returned is chosen arbitrarily from the matches.
   const FieldDescriptor* FindFieldByLowercaseName(
-      const std::string& lowercase_name) const;
+      ConstStringParam lowercase_name) const;
 
   // Looks up a field by camel-case name (as returned by camelcase_name()).
   // This lookup may be ambiguous if multiple field names differ in a way that
   // leads them to have identical camel-case names, in which case the field
   // returned is chosen arbitrarily from the matches.
   const FieldDescriptor* FindFieldByCamelcaseName(
-      const std::string& camelcase_name) const;
+      ConstStringParam camelcase_name) const;
 
   // The number of oneofs in this message type.
   int oneof_decl_count() const;
@@ -347,7 +347,7 @@
   const OneofDescriptor* oneof_decl(int index) const;
 
   // Looks up a oneof by name.  Returns nullptr if no such oneof exists.
-  const OneofDescriptor* FindOneofByName(const std::string& name) const;
+  const OneofDescriptor* FindOneofByName(ConstStringParam name) const;
 
   // Nested type stuff -----------------------------------------------
 
@@ -359,7 +359,7 @@
 
   // Looks up a nested type by name.  Returns nullptr if no such nested type
   // exists.
-  const Descriptor* FindNestedTypeByName(const std::string& name) const;
+  const Descriptor* FindNestedTypeByName(ConstStringParam name) const;
 
   // Enum stuff ------------------------------------------------------
 
@@ -371,11 +371,11 @@
 
   // Looks up an enum type by name.  Returns nullptr if no such enum type
   // exists.
-  const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
+  const EnumDescriptor* FindEnumTypeByName(ConstStringParam name) const;
 
   // Looks up an enum value by name, among all enum types in this message.
   // Returns nullptr if no such value exists.
-  const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
+  const EnumValueDescriptor* FindEnumValueByName(ConstStringParam name) const;
 
   // Extensions ------------------------------------------------------
 
@@ -439,17 +439,17 @@
 
   // Looks up a named extension (which extends some *other* message type)
   // defined within this message type's scope.
-  const FieldDescriptor* FindExtensionByName(const std::string& name) const;
+  const FieldDescriptor* FindExtensionByName(ConstStringParam name) const;
 
   // Similar to FindFieldByLowercaseName(), but finds extensions defined within
   // this message type's scope.
   const FieldDescriptor* FindExtensionByLowercaseName(
-      const std::string& name) const;
+      ConstStringParam name) const;
 
   // Similar to FindFieldByCamelcaseName(), but finds extensions defined within
   // this message type's scope.
   const FieldDescriptor* FindExtensionByCamelcaseName(
-      const std::string& name) const;
+      ConstStringParam name) const;
 
   // Reserved fields -------------------------------------------------
 
@@ -479,7 +479,7 @@
   const std::string& reserved_name(int index) const;
 
   // Returns true if the field name is reserved.
-  bool IsReservedName(const std::string& name) const;
+  bool IsReservedName(ConstStringParam name) const;
 
   // Source Location ---------------------------------------------------
 
@@ -1088,7 +1088,7 @@
   const std::string& reserved_name(int index) const;
 
   // Returns true if the field name is reserved.
-  bool IsReservedName(const std::string& name) const;
+  bool IsReservedName(ConstStringParam name) const;
 
   // Source Location ---------------------------------------------------
 
@@ -1267,7 +1267,7 @@
   const MethodDescriptor* method(int index) const;
 
   // Look up a MethodDescriptor by name.
-  const MethodDescriptor* FindMethodByName(const std::string& name) const;
+  const MethodDescriptor* FindMethodByName(ConstStringParam name) const;
   // See Descriptor::CopyTo().
   void CopyTo(ServiceDescriptorProto* proto) const;
 
@@ -1488,25 +1488,25 @@
   static const char* SyntaxName(Syntax syntax);
 
   // Find a top-level message type by name.  Returns nullptr if not found.
-  const Descriptor* FindMessageTypeByName(const std::string& name) const;
+  const Descriptor* FindMessageTypeByName(ConstStringParam name) const;
   // Find a top-level enum type by name.  Returns nullptr if not found.
-  const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
+  const EnumDescriptor* FindEnumTypeByName(ConstStringParam name) const;
   // Find an enum value defined in any top-level enum by name.  Returns nullptr
   // if not found.
-  const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
+  const EnumValueDescriptor* FindEnumValueByName(ConstStringParam name) const;
   // Find a service definition by name.  Returns nullptr if not found.
-  const ServiceDescriptor* FindServiceByName(const std::string& name) const;
+  const ServiceDescriptor* FindServiceByName(ConstStringParam name) const;
   // Find a top-level extension definition by name.  Returns nullptr if not
   // found.
-  const FieldDescriptor* FindExtensionByName(const std::string& name) const;
+  const FieldDescriptor* FindExtensionByName(ConstStringParam name) const;
   // Similar to FindExtensionByName(), but searches by lowercased-name.  See
   // Descriptor::FindFieldByLowercaseName().
   const FieldDescriptor* FindExtensionByLowercaseName(
-      const std::string& name) const;
+      ConstStringParam name) const;
   // Similar to FindExtensionByName(), but searches by camelcased-name.  See
   // Descriptor::FindFieldByCamelcaseName().
   const FieldDescriptor* FindExtensionByCamelcaseName(
-      const std::string& name) const;
+      ConstStringParam name) const;
 
   // See Descriptor::CopyTo().
   // Notes:
@@ -1669,28 +1669,28 @@
 
   // Find a FileDescriptor in the pool by file name.  Returns nullptr if not
   // found.
-  const FileDescriptor* FindFileByName(const std::string& name) const;
+  const FileDescriptor* FindFileByName(ConstStringParam name) const;
 
   // Find the FileDescriptor in the pool which defines the given symbol.
   // If any of the Find*ByName() methods below would succeed, then this is
   // equivalent to calling that method and calling the result's file() method.
   // Otherwise this returns nullptr.
   const FileDescriptor* FindFileContainingSymbol(
-      const std::string& symbol_name) const;
+      ConstStringParam symbol_name) const;
 
   // Looking up descriptors ------------------------------------------
   // These find descriptors by fully-qualified name.  These will find both
   // top-level descriptors and nested descriptors.  They return nullptr if not
   // found.
 
-  const Descriptor* FindMessageTypeByName(const std::string& name) const;
-  const FieldDescriptor* FindFieldByName(const std::string& name) const;
-  const FieldDescriptor* FindExtensionByName(const std::string& name) const;
-  const OneofDescriptor* FindOneofByName(const std::string& name) const;
-  const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
-  const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
-  const ServiceDescriptor* FindServiceByName(const std::string& name) const;
-  const MethodDescriptor* FindMethodByName(const std::string& name) const;
+  const Descriptor* FindMessageTypeByName(ConstStringParam name) const;
+  const FieldDescriptor* FindFieldByName(ConstStringParam name) const;
+  const FieldDescriptor* FindExtensionByName(ConstStringParam name) const;
+  const OneofDescriptor* FindOneofByName(ConstStringParam name) const;
+  const EnumDescriptor* FindEnumTypeByName(ConstStringParam name) const;
+  const EnumValueDescriptor* FindEnumValueByName(ConstStringParam name) const;
+  const ServiceDescriptor* FindServiceByName(ConstStringParam name) const;
+  const MethodDescriptor* FindMethodByName(ConstStringParam name) const;
 
   // Finds an extension of the given type by number.  The extendee must be
   // a member of this DescriptorPool or one of its underlays.
@@ -1703,7 +1703,7 @@
   // or one of its underlays.  Returns nullptr if there is no known message
   // extension with the given printable name.
   const FieldDescriptor* FindExtensionByPrintableName(
-      const Descriptor* extendee, const std::string& printable_name) const;
+      const Descriptor* extendee, ConstStringParam printable_name) const;
 
   // Finds extensions of extendee. The extensions will be appended to
   // out in an undefined order. Only extensions defined directly in
@@ -1876,11 +1876,11 @@
   // For internal (unit test) use only:  Returns true if a FileDescriptor has
   // been constructed for the given file, false otherwise.  Useful for testing
   // lazy descriptor initialization behavior.
-  bool InternalIsFileLoaded(const std::string& filename) const;
+  bool InternalIsFileLoaded(ConstStringParam filename) const;
 
   // Add a file to unused_import_track_files_. DescriptorBuilder will log
   // warnings or errors for those files if there is any unused import.
-  void AddUnusedImportTrackFile(const std::string& file_name,
+  void AddUnusedImportTrackFile(ConstStringParam file_name,
                                 bool is_error = false);
   void ClearUnusedImportTrackFiles();
 
@@ -1899,14 +1899,14 @@
   // Return true if the given name is a sub-symbol of any non-package
   // descriptor that already exists in the descriptor pool.  (The full
   // definition of such types is already known.)
-  bool IsSubSymbolOfBuiltType(const std::string& name) const;
+  bool IsSubSymbolOfBuiltType(StringPiece name) const;
 
   // Tries to find something in the fallback database and link in the
   // corresponding proto file.  Returns true if successful, in which case
   // the caller should search for the thing again.  These are declared
   // const because they are called by (semantically) const methods.
-  bool TryFindFileInFallbackDatabase(const std::string& name) const;
-  bool TryFindSymbolInFallbackDatabase(const std::string& name) const;
+  bool TryFindFileInFallbackDatabase(StringPiece name) const;
+  bool TryFindSymbolInFallbackDatabase(StringPiece name) const;
   bool TryFindExtensionInFallbackDatabase(const Descriptor* containing_type,
                                           int field_number) const;
 
@@ -1927,13 +1927,12 @@
   // symbol is defined if necessary. Will create a placeholder if the type
   // doesn't exist in the fallback database, or the file doesn't build
   // successfully.
-  Symbol CrossLinkOnDemandHelper(const std::string& name,
+  Symbol CrossLinkOnDemandHelper(StringPiece name,
                                  bool expecting_enum) const;
 
   // Create a placeholder FileDescriptor of the specified name
-  FileDescriptor* NewPlaceholderFile(const std::string& name) const;
-  FileDescriptor* NewPlaceholderFileWithMutexHeld(
-      const std::string& name) const;
+  FileDescriptor* NewPlaceholderFile(StringPiece name) const;
+  FileDescriptor* NewPlaceholderFileWithMutexHeld(StringPiece name) const;
 
   enum PlaceholderType {
     PLACEHOLDER_MESSAGE,
@@ -1941,9 +1940,9 @@
     PLACEHOLDER_EXTENDABLE_MESSAGE
   };
   // Create a placeholder Descriptor of the specified name
-  Symbol NewPlaceholder(const std::string& name,
+  Symbol NewPlaceholder(StringPiece name,
                         PlaceholderType placeholder_type) const;
-  Symbol NewPlaceholderWithMutexHeld(const std::string& name,
+  Symbol NewPlaceholderWithMutexHeld(StringPiece name,
                                      PlaceholderType placeholder_type) const;
 
   // If fallback_database_ is nullptr, this is nullptr.  Otherwise, this is a
@@ -2126,9 +2125,9 @@
   return FindReservedRangeContainingNumber(number) != nullptr;
 }
 
-inline bool Descriptor::IsReservedName(const std::string& name) const {
+inline bool Descriptor::IsReservedName(ConstStringParam name) const {
   for (int i = 0; i < reserved_name_count(); i++) {
-    if (name == reserved_name(i)) {
+    if (name == static_cast<ConstStringParam>(reserved_name(i))) {
       return true;
     }
   }
@@ -2145,9 +2144,9 @@
   return FindReservedRangeContainingNumber(number) != nullptr;
 }
 
-inline bool EnumDescriptor::IsReservedName(const std::string& name) const {
+inline bool EnumDescriptor::IsReservedName(ConstStringParam name) const {
   for (int i = 0; i < reserved_name_count(); i++) {
-    if (name == reserved_name(i)) {
+    if (name == static_cast<ConstStringParam>(reserved_name(i))) {
       return true;
     }
   }
diff --git a/src/google/protobuf/descriptor.pb.h b/src/google/protobuf/descriptor.pb.h
index da02ab4..fd0ed66 100644
--- a/src/google/protobuf/descriptor.pb.h
+++ b/src/google/protobuf/descriptor.pb.h
@@ -770,15 +770,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -799,15 +790,6 @@
   std::string* mutable_package();
   std::string* release_package();
   void set_allocated_package(std::string* package);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_package();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_package(
-      std::string* package);
   private:
   const std::string& _internal_package() const;
   void _internal_set_package(const std::string& value);
@@ -828,15 +810,6 @@
   std::string* mutable_syntax();
   std::string* release_syntax();
   void set_allocated_syntax(std::string* syntax);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_syntax();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_syntax(
-      std::string* syntax);
   private:
   const std::string& _internal_syntax() const;
   void _internal_set_syntax(const std::string& value);
@@ -1550,15 +1523,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -2002,15 +1966,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -2031,15 +1986,6 @@
   std::string* mutable_extendee();
   std::string* release_extendee();
   void set_allocated_extendee(std::string* extendee);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_extendee();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_extendee(
-      std::string* extendee);
   private:
   const std::string& _internal_extendee() const;
   void _internal_set_extendee(const std::string& value);
@@ -2060,15 +2006,6 @@
   std::string* mutable_type_name();
   std::string* release_type_name();
   void set_allocated_type_name(std::string* type_name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_type_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_type_name(
-      std::string* type_name);
   private:
   const std::string& _internal_type_name() const;
   void _internal_set_type_name(const std::string& value);
@@ -2089,15 +2026,6 @@
   std::string* mutable_default_value();
   std::string* release_default_value();
   void set_allocated_default_value(std::string* default_value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_default_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_default_value(
-      std::string* default_value);
   private:
   const std::string& _internal_default_value() const;
   void _internal_set_default_value(const std::string& value);
@@ -2118,15 +2046,6 @@
   std::string* mutable_json_name();
   std::string* release_json_name();
   void set_allocated_json_name(std::string* json_name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_json_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_json_name(
-      std::string* json_name);
   private:
   const std::string& _internal_json_name() const;
   void _internal_set_json_name(const std::string& value);
@@ -2377,15 +2296,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -2791,15 +2701,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -2980,15 +2881,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -3198,15 +3090,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -3388,15 +3271,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -3417,15 +3291,6 @@
   std::string* mutable_input_type();
   std::string* release_input_type();
   void set_allocated_input_type(std::string* input_type);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_input_type();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_input_type(
-      std::string* input_type);
   private:
   const std::string& _internal_input_type() const;
   void _internal_set_input_type(const std::string& value);
@@ -3446,15 +3311,6 @@
   std::string* mutable_output_type();
   std::string* release_output_type();
   void set_allocated_output_type(std::string* output_type);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_output_type();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_output_type(
-      std::string* output_type);
   private:
   const std::string& _internal_output_type() const;
   void _internal_set_output_type(const std::string& value);
@@ -3730,15 +3586,6 @@
   std::string* mutable_java_package();
   std::string* release_java_package();
   void set_allocated_java_package(std::string* java_package);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_java_package();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_java_package(
-      std::string* java_package);
   private:
   const std::string& _internal_java_package() const;
   void _internal_set_java_package(const std::string& value);
@@ -3759,15 +3606,6 @@
   std::string* mutable_java_outer_classname();
   std::string* release_java_outer_classname();
   void set_allocated_java_outer_classname(std::string* java_outer_classname);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_java_outer_classname();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_java_outer_classname(
-      std::string* java_outer_classname);
   private:
   const std::string& _internal_java_outer_classname() const;
   void _internal_set_java_outer_classname(const std::string& value);
@@ -3788,15 +3626,6 @@
   std::string* mutable_go_package();
   std::string* release_go_package();
   void set_allocated_go_package(std::string* go_package);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_go_package();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_go_package(
-      std::string* go_package);
   private:
   const std::string& _internal_go_package() const;
   void _internal_set_go_package(const std::string& value);
@@ -3817,15 +3646,6 @@
   std::string* mutable_objc_class_prefix();
   std::string* release_objc_class_prefix();
   void set_allocated_objc_class_prefix(std::string* objc_class_prefix);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_objc_class_prefix();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_objc_class_prefix(
-      std::string* objc_class_prefix);
   private:
   const std::string& _internal_objc_class_prefix() const;
   void _internal_set_objc_class_prefix(const std::string& value);
@@ -3846,15 +3666,6 @@
   std::string* mutable_csharp_namespace();
   std::string* release_csharp_namespace();
   void set_allocated_csharp_namespace(std::string* csharp_namespace);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_csharp_namespace();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_csharp_namespace(
-      std::string* csharp_namespace);
   private:
   const std::string& _internal_csharp_namespace() const;
   void _internal_set_csharp_namespace(const std::string& value);
@@ -3875,15 +3686,6 @@
   std::string* mutable_swift_prefix();
   std::string* release_swift_prefix();
   void set_allocated_swift_prefix(std::string* swift_prefix);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_swift_prefix();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_swift_prefix(
-      std::string* swift_prefix);
   private:
   const std::string& _internal_swift_prefix() const;
   void _internal_set_swift_prefix(const std::string& value);
@@ -3904,15 +3706,6 @@
   std::string* mutable_php_class_prefix();
   std::string* release_php_class_prefix();
   void set_allocated_php_class_prefix(std::string* php_class_prefix);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_php_class_prefix();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_php_class_prefix(
-      std::string* php_class_prefix);
   private:
   const std::string& _internal_php_class_prefix() const;
   void _internal_set_php_class_prefix(const std::string& value);
@@ -3933,15 +3726,6 @@
   std::string* mutable_php_namespace();
   std::string* release_php_namespace();
   void set_allocated_php_namespace(std::string* php_namespace);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_php_namespace();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_php_namespace(
-      std::string* php_namespace);
   private:
   const std::string& _internal_php_namespace() const;
   void _internal_set_php_namespace(const std::string& value);
@@ -3962,15 +3746,6 @@
   std::string* mutable_php_metadata_namespace();
   std::string* release_php_metadata_namespace();
   void set_allocated_php_metadata_namespace(std::string* php_metadata_namespace);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_php_metadata_namespace();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_php_metadata_namespace(
-      std::string* php_metadata_namespace);
   private:
   const std::string& _internal_php_metadata_namespace() const;
   void _internal_set_php_metadata_namespace(const std::string& value);
@@ -3991,15 +3766,6 @@
   std::string* mutable_ruby_package();
   std::string* release_ruby_package();
   void set_allocated_ruby_package(std::string* ruby_package);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_ruby_package();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_ruby_package(
-      std::string* ruby_package);
   private:
   const std::string& _internal_ruby_package() const;
   void _internal_set_ruby_package(const std::string& value);
@@ -5744,15 +5510,6 @@
   std::string* mutable_name_part();
   std::string* release_name_part();
   void set_allocated_name_part(std::string* name_part);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name_part();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name_part(
-      std::string* name_part);
   private:
   const std::string& _internal_name_part() const;
   void _internal_set_name_part(const std::string& value);
@@ -5952,15 +5709,6 @@
   std::string* mutable_identifier_value();
   std::string* release_identifier_value();
   void set_allocated_identifier_value(std::string* identifier_value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_identifier_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_identifier_value(
-      std::string* identifier_value);
   private:
   const std::string& _internal_identifier_value() const;
   void _internal_set_identifier_value(const std::string& value);
@@ -5981,15 +5729,6 @@
   std::string* mutable_string_value();
   std::string* release_string_value();
   void set_allocated_string_value(std::string* string_value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_string_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_string_value(
-      std::string* string_value);
   private:
   const std::string& _internal_string_value() const;
   void _internal_set_string_value(const std::string& value);
@@ -6010,15 +5749,6 @@
   std::string* mutable_aggregate_value();
   std::string* release_aggregate_value();
   void set_allocated_aggregate_value(std::string* aggregate_value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_aggregate_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_aggregate_value(
-      std::string* aggregate_value);
   private:
   const std::string& _internal_aggregate_value() const;
   void _internal_set_aggregate_value(const std::string& value);
@@ -6292,15 +6022,6 @@
   std::string* mutable_leading_comments();
   std::string* release_leading_comments();
   void set_allocated_leading_comments(std::string* leading_comments);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_leading_comments();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_leading_comments(
-      std::string* leading_comments);
   private:
   const std::string& _internal_leading_comments() const;
   void _internal_set_leading_comments(const std::string& value);
@@ -6321,15 +6042,6 @@
   std::string* mutable_trailing_comments();
   std::string* release_trailing_comments();
   void set_allocated_trailing_comments(std::string* trailing_comments);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_trailing_comments();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_trailing_comments(
-      std::string* trailing_comments);
   private:
   const std::string& _internal_trailing_comments() const;
   void _internal_set_trailing_comments(const std::string& value);
@@ -6672,15 +6384,6 @@
   std::string* mutable_source_file();
   std::string* release_source_file();
   void set_allocated_source_file(std::string* source_file);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_source_file();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_source_file(
-      std::string* source_file);
   private:
   const std::string& _internal_source_file() const;
   void _internal_set_source_file(const std::string& value);
@@ -7011,25 +6714,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileDescriptorProto.name)
 }
-inline std::string* FileDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileDescriptorProto.name)
-}
 
 // optional string package = 2;
 inline bool FileDescriptorProto::_internal_has_package() const {
@@ -7104,25 +6788,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileDescriptorProto.package)
 }
-inline std::string* FileDescriptorProto::unsafe_arena_release_package() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileDescriptorProto.package)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return package_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileDescriptorProto::unsafe_arena_set_allocated_package(
-    std::string* package) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (package != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  package_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      package, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileDescriptorProto.package)
-}
 
 // repeated string dependency = 3;
 inline int FileDescriptorProto::_internal_dependency_size() const {
@@ -7687,25 +7352,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileDescriptorProto.syntax)
 }
-inline std::string* FileDescriptorProto::unsafe_arena_release_syntax() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileDescriptorProto.syntax)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000004u;
-  return syntax_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileDescriptorProto::unsafe_arena_set_allocated_syntax(
-    std::string* syntax) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (syntax != nullptr) {
-    _has_bits_[0] |= 0x00000004u;
-  } else {
-    _has_bits_[0] &= ~0x00000004u;
-  }
-  syntax_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      syntax, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileDescriptorProto.syntax)
-}
 
 // -------------------------------------------------------------------
 
@@ -7987,25 +7633,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.DescriptorProto.name)
 }
-inline std::string* DescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.DescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void DescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.DescriptorProto.name)
-}
 
 // repeated .google.protobuf.FieldDescriptorProto field = 2;
 inline int DescriptorProto::_internal_field_size() const {
@@ -8557,25 +8184,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FieldDescriptorProto.name)
 }
-inline std::string* FieldDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FieldDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FieldDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FieldDescriptorProto.name)
-}
 
 // optional int32 number = 3;
 inline bool FieldDescriptorProto::_internal_has_number() const {
@@ -8736,25 +8344,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FieldDescriptorProto.type_name)
 }
-inline std::string* FieldDescriptorProto::unsafe_arena_release_type_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FieldDescriptorProto.type_name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000004u;
-  return type_name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FieldDescriptorProto::unsafe_arena_set_allocated_type_name(
-    std::string* type_name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (type_name != nullptr) {
-    _has_bits_[0] |= 0x00000004u;
-  } else {
-    _has_bits_[0] &= ~0x00000004u;
-  }
-  type_name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      type_name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FieldDescriptorProto.type_name)
-}
 
 // optional string extendee = 2;
 inline bool FieldDescriptorProto::_internal_has_extendee() const {
@@ -8829,25 +8418,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FieldDescriptorProto.extendee)
 }
-inline std::string* FieldDescriptorProto::unsafe_arena_release_extendee() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FieldDescriptorProto.extendee)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return extendee_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FieldDescriptorProto::unsafe_arena_set_allocated_extendee(
-    std::string* extendee) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (extendee != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  extendee_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      extendee, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FieldDescriptorProto.extendee)
-}
 
 // optional string default_value = 7;
 inline bool FieldDescriptorProto::_internal_has_default_value() const {
@@ -8922,25 +8492,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FieldDescriptorProto.default_value)
 }
-inline std::string* FieldDescriptorProto::unsafe_arena_release_default_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FieldDescriptorProto.default_value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000008u;
-  return default_value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FieldDescriptorProto::unsafe_arena_set_allocated_default_value(
-    std::string* default_value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (default_value != nullptr) {
-    _has_bits_[0] |= 0x00000008u;
-  } else {
-    _has_bits_[0] &= ~0x00000008u;
-  }
-  default_value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      default_value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FieldDescriptorProto.default_value)
-}
 
 // optional int32 oneof_index = 9;
 inline bool FieldDescriptorProto::_internal_has_oneof_index() const {
@@ -9043,25 +8594,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FieldDescriptorProto.json_name)
 }
-inline std::string* FieldDescriptorProto::unsafe_arena_release_json_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FieldDescriptorProto.json_name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000010u;
-  return json_name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FieldDescriptorProto::unsafe_arena_set_allocated_json_name(
-    std::string* json_name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (json_name != nullptr) {
-    _has_bits_[0] |= 0x00000010u;
-  } else {
-    _has_bits_[0] &= ~0x00000010u;
-  }
-  json_name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      json_name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FieldDescriptorProto.json_name)
-}
 
 // optional .google.protobuf.FieldOptions options = 8;
 inline bool FieldDescriptorProto::_internal_has_options() const {
@@ -9251,25 +8783,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.OneofDescriptorProto.name)
 }
-inline std::string* OneofDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.OneofDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void OneofDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.OneofDescriptorProto.name)
-}
 
 // optional .google.protobuf.OneofOptions options = 2;
 inline bool OneofDescriptorProto::_internal_has_options() const {
@@ -9491,25 +9004,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.EnumDescriptorProto.name)
 }
-inline std::string* EnumDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.EnumDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void EnumDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.EnumDescriptorProto.name)
-}
 
 // repeated .google.protobuf.EnumValueDescriptorProto value = 2;
 inline int EnumDescriptorProto::_internal_value_size() const {
@@ -9823,25 +9317,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.EnumValueDescriptorProto.name)
 }
-inline std::string* EnumValueDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.EnumValueDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void EnumValueDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.EnumValueDescriptorProto.name)
-}
 
 // optional int32 number = 2;
 inline bool EnumValueDescriptorProto::_internal_has_number() const {
@@ -10031,25 +9506,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.ServiceDescriptorProto.name)
 }
-inline std::string* ServiceDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.ServiceDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void ServiceDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.ServiceDescriptorProto.name)
-}
 
 // repeated .google.protobuf.MethodDescriptorProto method = 2;
 inline int ServiceDescriptorProto::_internal_method_size() const {
@@ -10250,25 +9706,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.MethodDescriptorProto.name)
 }
-inline std::string* MethodDescriptorProto::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.MethodDescriptorProto.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void MethodDescriptorProto::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.MethodDescriptorProto.name)
-}
 
 // optional string input_type = 2;
 inline bool MethodDescriptorProto::_internal_has_input_type() const {
@@ -10343,25 +9780,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.MethodDescriptorProto.input_type)
 }
-inline std::string* MethodDescriptorProto::unsafe_arena_release_input_type() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.MethodDescriptorProto.input_type)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return input_type_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void MethodDescriptorProto::unsafe_arena_set_allocated_input_type(
-    std::string* input_type) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (input_type != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  input_type_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      input_type, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.MethodDescriptorProto.input_type)
-}
 
 // optional string output_type = 3;
 inline bool MethodDescriptorProto::_internal_has_output_type() const {
@@ -10436,25 +9854,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.MethodDescriptorProto.output_type)
 }
-inline std::string* MethodDescriptorProto::unsafe_arena_release_output_type() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.MethodDescriptorProto.output_type)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000004u;
-  return output_type_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void MethodDescriptorProto::unsafe_arena_set_allocated_output_type(
-    std::string* output_type) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (output_type != nullptr) {
-    _has_bits_[0] |= 0x00000004u;
-  } else {
-    _has_bits_[0] &= ~0x00000004u;
-  }
-  output_type_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      output_type, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.MethodDescriptorProto.output_type)
-}
 
 // optional .google.protobuf.MethodOptions options = 4;
 inline bool MethodDescriptorProto::_internal_has_options() const {
@@ -10672,25 +10071,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.java_package)
 }
-inline std::string* FileOptions::unsafe_arena_release_java_package() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.java_package)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return java_package_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_java_package(
-    std::string* java_package) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (java_package != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  java_package_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      java_package, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.java_package)
-}
 
 // optional string java_outer_classname = 8;
 inline bool FileOptions::_internal_has_java_outer_classname() const {
@@ -10765,25 +10145,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.java_outer_classname)
 }
-inline std::string* FileOptions::unsafe_arena_release_java_outer_classname() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.java_outer_classname)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return java_outer_classname_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_java_outer_classname(
-    std::string* java_outer_classname) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (java_outer_classname != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  java_outer_classname_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      java_outer_classname, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.java_outer_classname)
-}
 
 // optional bool java_multiple_files = 10 [default = false];
 inline bool FileOptions::_internal_has_java_multiple_files() const {
@@ -10971,25 +10332,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.go_package)
 }
-inline std::string* FileOptions::unsafe_arena_release_go_package() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.go_package)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000004u;
-  return go_package_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_go_package(
-    std::string* go_package) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (go_package != nullptr) {
-    _has_bits_[0] |= 0x00000004u;
-  } else {
-    _has_bits_[0] &= ~0x00000004u;
-  }
-  go_package_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      go_package, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.go_package)
-}
 
 // optional bool cc_generic_services = 16 [default = false];
 inline bool FileOptions::_internal_has_cc_generic_services() const {
@@ -11232,25 +10574,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.objc_class_prefix)
 }
-inline std::string* FileOptions::unsafe_arena_release_objc_class_prefix() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.objc_class_prefix)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000008u;
-  return objc_class_prefix_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_objc_class_prefix(
-    std::string* objc_class_prefix) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (objc_class_prefix != nullptr) {
-    _has_bits_[0] |= 0x00000008u;
-  } else {
-    _has_bits_[0] &= ~0x00000008u;
-  }
-  objc_class_prefix_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      objc_class_prefix, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.objc_class_prefix)
-}
 
 // optional string csharp_namespace = 37;
 inline bool FileOptions::_internal_has_csharp_namespace() const {
@@ -11325,25 +10648,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.csharp_namespace)
 }
-inline std::string* FileOptions::unsafe_arena_release_csharp_namespace() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.csharp_namespace)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000010u;
-  return csharp_namespace_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_csharp_namespace(
-    std::string* csharp_namespace) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (csharp_namespace != nullptr) {
-    _has_bits_[0] |= 0x00000010u;
-  } else {
-    _has_bits_[0] &= ~0x00000010u;
-  }
-  csharp_namespace_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      csharp_namespace, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.csharp_namespace)
-}
 
 // optional string swift_prefix = 39;
 inline bool FileOptions::_internal_has_swift_prefix() const {
@@ -11418,25 +10722,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.swift_prefix)
 }
-inline std::string* FileOptions::unsafe_arena_release_swift_prefix() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.swift_prefix)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000020u;
-  return swift_prefix_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_swift_prefix(
-    std::string* swift_prefix) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (swift_prefix != nullptr) {
-    _has_bits_[0] |= 0x00000020u;
-  } else {
-    _has_bits_[0] &= ~0x00000020u;
-  }
-  swift_prefix_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      swift_prefix, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.swift_prefix)
-}
 
 // optional string php_class_prefix = 40;
 inline bool FileOptions::_internal_has_php_class_prefix() const {
@@ -11511,25 +10796,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.php_class_prefix)
 }
-inline std::string* FileOptions::unsafe_arena_release_php_class_prefix() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.php_class_prefix)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000040u;
-  return php_class_prefix_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_php_class_prefix(
-    std::string* php_class_prefix) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (php_class_prefix != nullptr) {
-    _has_bits_[0] |= 0x00000040u;
-  } else {
-    _has_bits_[0] &= ~0x00000040u;
-  }
-  php_class_prefix_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      php_class_prefix, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.php_class_prefix)
-}
 
 // optional string php_namespace = 41;
 inline bool FileOptions::_internal_has_php_namespace() const {
@@ -11604,25 +10870,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.php_namespace)
 }
-inline std::string* FileOptions::unsafe_arena_release_php_namespace() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.php_namespace)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000080u;
-  return php_namespace_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_php_namespace(
-    std::string* php_namespace) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (php_namespace != nullptr) {
-    _has_bits_[0] |= 0x00000080u;
-  } else {
-    _has_bits_[0] &= ~0x00000080u;
-  }
-  php_namespace_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      php_namespace, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.php_namespace)
-}
 
 // optional string php_metadata_namespace = 44;
 inline bool FileOptions::_internal_has_php_metadata_namespace() const {
@@ -11697,25 +10944,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.php_metadata_namespace)
 }
-inline std::string* FileOptions::unsafe_arena_release_php_metadata_namespace() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.php_metadata_namespace)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000100u;
-  return php_metadata_namespace_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_php_metadata_namespace(
-    std::string* php_metadata_namespace) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (php_metadata_namespace != nullptr) {
-    _has_bits_[0] |= 0x00000100u;
-  } else {
-    _has_bits_[0] &= ~0x00000100u;
-  }
-  php_metadata_namespace_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      php_metadata_namespace, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.php_metadata_namespace)
-}
 
 // optional string ruby_package = 45;
 inline bool FileOptions::_internal_has_ruby_package() const {
@@ -11790,25 +11018,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.FileOptions.ruby_package)
 }
-inline std::string* FileOptions::unsafe_arena_release_ruby_package() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.FileOptions.ruby_package)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000200u;
-  return ruby_package_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void FileOptions::unsafe_arena_set_allocated_ruby_package(
-    std::string* ruby_package) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (ruby_package != nullptr) {
-    _has_bits_[0] |= 0x00000200u;
-  } else {
-    _has_bits_[0] &= ~0x00000200u;
-  }
-  ruby_package_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      ruby_package, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.FileOptions.ruby_package)
-}
 
 // repeated .google.protobuf.UninterpretedOption uninterpreted_option = 999;
 inline int FileOptions::_internal_uninterpreted_option_size() const {
@@ -12678,25 +11887,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.UninterpretedOption.NamePart.name_part)
 }
-inline std::string* UninterpretedOption_NamePart::unsafe_arena_release_name_part() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.UninterpretedOption.NamePart.name_part)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return name_part_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void UninterpretedOption_NamePart::unsafe_arena_set_allocated_name_part(
-    std::string* name_part) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name_part != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  name_part_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name_part, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.UninterpretedOption.NamePart.name_part)
-}
 
 // required bool is_extension = 2;
 inline bool UninterpretedOption_NamePart::_internal_has_is_extension() const {
@@ -12842,25 +12032,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.UninterpretedOption.identifier_value)
 }
-inline std::string* UninterpretedOption::unsafe_arena_release_identifier_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.UninterpretedOption.identifier_value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return identifier_value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void UninterpretedOption::unsafe_arena_set_allocated_identifier_value(
-    std::string* identifier_value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (identifier_value != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  identifier_value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      identifier_value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.UninterpretedOption.identifier_value)
-}
 
 // optional uint64 positive_int_value = 4;
 inline bool UninterpretedOption::_internal_has_positive_int_value() const {
@@ -13019,25 +12190,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.UninterpretedOption.string_value)
 }
-inline std::string* UninterpretedOption::unsafe_arena_release_string_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.UninterpretedOption.string_value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return string_value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void UninterpretedOption::unsafe_arena_set_allocated_string_value(
-    std::string* string_value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (string_value != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  string_value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      string_value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.UninterpretedOption.string_value)
-}
 
 // optional string aggregate_value = 8;
 inline bool UninterpretedOption::_internal_has_aggregate_value() const {
@@ -13112,25 +12264,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.UninterpretedOption.aggregate_value)
 }
-inline std::string* UninterpretedOption::unsafe_arena_release_aggregate_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.UninterpretedOption.aggregate_value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000004u;
-  return aggregate_value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void UninterpretedOption::unsafe_arena_set_allocated_aggregate_value(
-    std::string* aggregate_value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (aggregate_value != nullptr) {
-    _has_bits_[0] |= 0x00000004u;
-  } else {
-    _has_bits_[0] &= ~0x00000004u;
-  }
-  aggregate_value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      aggregate_value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.UninterpretedOption.aggregate_value)
-}
 
 // -------------------------------------------------------------------
 
@@ -13303,25 +12436,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.SourceCodeInfo.Location.leading_comments)
 }
-inline std::string* SourceCodeInfo_Location::unsafe_arena_release_leading_comments() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.SourceCodeInfo.Location.leading_comments)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return leading_comments_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void SourceCodeInfo_Location::unsafe_arena_set_allocated_leading_comments(
-    std::string* leading_comments) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (leading_comments != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  leading_comments_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      leading_comments, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.SourceCodeInfo.Location.leading_comments)
-}
 
 // optional string trailing_comments = 4;
 inline bool SourceCodeInfo_Location::_internal_has_trailing_comments() const {
@@ -13396,25 +12510,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.SourceCodeInfo.Location.trailing_comments)
 }
-inline std::string* SourceCodeInfo_Location::unsafe_arena_release_trailing_comments() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.SourceCodeInfo.Location.trailing_comments)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000002u;
-  return trailing_comments_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void SourceCodeInfo_Location::unsafe_arena_set_allocated_trailing_comments(
-    std::string* trailing_comments) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (trailing_comments != nullptr) {
-    _has_bits_[0] |= 0x00000002u;
-  } else {
-    _has_bits_[0] &= ~0x00000002u;
-  }
-  trailing_comments_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      trailing_comments, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.SourceCodeInfo.Location.trailing_comments)
-}
 
 // repeated string leading_detached_comments = 6;
 inline int SourceCodeInfo_Location::_internal_leading_detached_comments_size() const {
@@ -13657,25 +12752,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.GeneratedCodeInfo.Annotation.source_file)
 }
-inline std::string* GeneratedCodeInfo_Annotation::unsafe_arena_release_source_file() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.GeneratedCodeInfo.Annotation.source_file)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  _has_bits_[0] &= ~0x00000001u;
-  return source_file_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void GeneratedCodeInfo_Annotation::unsafe_arena_set_allocated_source_file(
-    std::string* source_file) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (source_file != nullptr) {
-    _has_bits_[0] |= 0x00000001u;
-  } else {
-    _has_bits_[0] &= ~0x00000001u;
-  }
-  source_file_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      source_file, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.GeneratedCodeInfo.Annotation.source_file)
-}
 
 // optional int32 begin = 3;
 inline bool GeneratedCodeInfo_Annotation::_internal_has_begin() const {
diff --git a/src/google/protobuf/descriptor_database.cc b/src/google/protobuf/descriptor_database.cc
index dbe1dc1..a332dab 100644
--- a/src/google/protobuf/descriptor_database.cc
+++ b/src/google/protobuf/descriptor_database.cc
@@ -390,8 +390,6 @@
 // -------------------------------------------------------------------
 
 class EncodedDescriptorDatabase::DescriptorIndex {
-  using String = std::string;
-
  public:
   using Value = std::pair<const void*, int>;
   // Helpers to recursively add particular descriptors and all their contents
@@ -410,15 +408,13 @@
  private:
   friend class EncodedDescriptorDatabase;
 
-  bool AddSymbol(StringPiece package, StringPiece symbol,
-                 Value value);
+  bool AddSymbol(StringPiece symbol);
 
   template <typename DescProto>
   bool AddNestedExtensions(StringPiece filename,
-                           const DescProto& message_type, Value value);
+                           const DescProto& message_type);
   template <typename FieldProto>
-  bool AddExtension(StringPiece filename, const FieldProto& field,
-                    Value value);
+  bool AddExtension(StringPiece filename, const FieldProto& field);
 
   // All the maps below have two representations:
   //  - a std::set<> where we insert initially.
@@ -429,47 +425,80 @@
 
   void EnsureFlat();
 
+  using String = std::string;
+
+  String EncodeString(StringPiece str) const { return String(str); }
+  StringPiece DecodeString(const String& str, int) const { return str; }
+
+  struct EncodedEntry {
+    // Do not use `Value` here to avoid the padding of that object.
+    const void* data;
+    int size;
+    // Keep the package here instead of each SymbolEntry to save space.
+    String encoded_package;
+
+    Value value() const { return {data, size}; }
+  };
+  std::vector<EncodedEntry> all_values_;
+
   struct FileEntry {
-    String name;
-    Value data;
+    int data_offset;
+    String encoded_name;
+
+    StringPiece name(const DescriptorIndex& index) const {
+      return index.DecodeString(encoded_name, data_offset);
+    }
   };
   struct FileCompare {
+    const DescriptorIndex& index;
+
     bool operator()(const FileEntry& a, const FileEntry& b) const {
-      return a.name < b.name;
+      return a.name(index) < b.name(index);
     }
     bool operator()(const FileEntry& a, StringPiece b) const {
-      return a.name < b;
+      return a.name(index) < b;
     }
     bool operator()(StringPiece a, const FileEntry& b) const {
-      return a < b.name;
+      return a < b.name(index);
     }
   };
-  std::set<FileEntry, FileCompare> by_name_;
+  std::set<FileEntry, FileCompare> by_name_{FileCompare{*this}};
   std::vector<FileEntry> by_name_flat_;
 
   struct SymbolEntry {
-    String package;
-    String symbol;
-    Value data;
+    int data_offset;
+    String encoded_symbol;
 
-    std::string AsString() const {
-      return StrCat(package, package.empty() ? "" : ".", symbol);
+    StringPiece package(const DescriptorIndex& index) const {
+      return index.DecodeString(index.all_values_[data_offset].encoded_package,
+                                data_offset);
+    }
+    StringPiece symbol(const DescriptorIndex& index) const {
+      return index.DecodeString(encoded_symbol, data_offset);
+    }
+
+    std::string AsString(const DescriptorIndex& index) const {
+      auto p = package(index);
+      return StrCat(p, p.empty() ? "" : ".", symbol(index));
     }
   };
 
   struct SymbolCompare {
-    static std::string AsString(const SymbolEntry& entry) {
-      return entry.AsString();
+    const DescriptorIndex& index;
+
+    std::string AsString(const SymbolEntry& entry) const {
+      return entry.AsString(index);
     }
     static StringPiece AsString(StringPiece str) { return str; }
 
-    static std::pair<StringPiece, StringPiece> GetParts(
-        const SymbolEntry& entry) {
-      if (entry.package.empty()) return {entry.symbol, StringPiece{}};
-      return {entry.package, entry.symbol};
+    std::pair<StringPiece, StringPiece> GetParts(
+        const SymbolEntry& entry) const {
+      auto package = entry.package(index);
+      if (package.empty()) return {entry.symbol(index), StringPiece{}};
+      return {package, entry.symbol(index)};
     }
-    static std::pair<StringPiece, StringPiece> GetParts(
-        StringPiece str) {
+    std::pair<StringPiece, StringPiece> GetParts(
+        StringPiece str) const {
       return {str, {}};
     }
 
@@ -490,29 +519,35 @@
       return AsString(lhs) < AsString(rhs);
     }
   };
-  std::set<SymbolEntry, SymbolCompare> by_symbol_;
+  std::set<SymbolEntry, SymbolCompare> by_symbol_{SymbolCompare{*this}};
   std::vector<SymbolEntry> by_symbol_flat_;
 
   struct ExtensionEntry {
-    String extendee;
+    int data_offset;
+    String encoded_extendee;
+    StringPiece extendee(const DescriptorIndex& index) const {
+      return index.DecodeString(encoded_extendee, data_offset).substr(1);
+    }
     int extension_number;
-    Value data;
   };
   struct ExtensionCompare {
+    const DescriptorIndex& index;
+
     bool operator()(const ExtensionEntry& a, const ExtensionEntry& b) const {
-      return std::tie(a.extendee, a.extension_number) <
-             std::tie(b.extendee, b.extension_number);
+      return std::make_tuple(a.extendee(index), a.extension_number) <
+             std::make_tuple(b.extendee(index), b.extension_number);
     }
     bool operator()(const ExtensionEntry& a,
                     std::tuple<StringPiece, int> b) const {
-      return std::tie(a.extendee, a.extension_number) < b;
+      return std::make_tuple(a.extendee(index), a.extension_number) < b;
     }
     bool operator()(std::tuple<StringPiece, int> a,
                     const ExtensionEntry& b) const {
-      return a < std::tie(b.extendee, b.extension_number);
+      return a < std::make_tuple(b.extendee(index), b.extension_number);
     }
   };
-  std::set<ExtensionEntry, ExtensionCompare> by_extension_;
+  std::set<ExtensionEntry, ExtensionCompare> by_extension_{
+      ExtensionCompare{*this}};
   std::vector<ExtensionEntry> by_extension_flat_;
 };
 
@@ -591,40 +626,51 @@
 template <typename FileProto>
 bool EncodedDescriptorDatabase::DescriptorIndex::AddFile(const FileProto& file,
                                                          Value value) {
-  if (!InsertIfNotPresent(&by_name_, FileEntry{file.name(), value}) ||
+  // We push `value` into the array first. This is important because the AddXXX
+  // functions below will expect it to be there.
+  all_values_.push_back({value.first, value.second});
+
+  if (!ValidateSymbolName(file.package())) {
+    GOOGLE_LOG(ERROR) << "Invalid package name: " << file.package();
+    return false;
+  }
+  all_values_.back().encoded_package = EncodeString(file.package());
+
+  if (!InsertIfNotPresent(
+          &by_name_, FileEntry{static_cast<int>(all_values_.size() - 1),
+                               EncodeString(file.name())}) ||
       std::binary_search(by_name_flat_.begin(), by_name_flat_.end(),
                          file.name(), by_name_.key_comp())) {
     GOOGLE_LOG(ERROR) << "File already exists in database: " << file.name();
     return false;
   }
 
-  StringPiece package = file.package();
   for (const auto& message_type : file.message_type()) {
-    if (!AddSymbol(package, message_type.name(), value)) return false;
-    if (!AddNestedExtensions(file.name(), message_type, value)) return false;
+    if (!AddSymbol(message_type.name())) return false;
+    if (!AddNestedExtensions(file.name(), message_type)) return false;
   }
   for (const auto& enum_type : file.enum_type()) {
-    if (!AddSymbol(package, enum_type.name(), value)) return false;
+    if (!AddSymbol(enum_type.name())) return false;
   }
   for (const auto& extension : file.extension()) {
-    if (!AddSymbol(package, extension.name(), value)) return false;
-    if (!AddExtension(file.name(), extension, value)) return false;
+    if (!AddSymbol(extension.name())) return false;
+    if (!AddExtension(file.name(), extension)) return false;
   }
   for (const auto& service : file.service()) {
-    if (!AddSymbol(package, service.name(), value)) return false;
+    if (!AddSymbol(service.name())) return false;
   }
 
   return true;
 }
 
-template <typename Iter, typename Iter2>
+template <typename Iter, typename Iter2, typename Index>
 static bool CheckForMutualSubsymbols(StringPiece symbol_name, Iter* iter,
-                                     Iter2 end) {
+                                     Iter2 end, const Index& index) {
   if (*iter != end) {
-    if (IsSubSymbol((*iter)->AsString(), symbol_name)) {
+    if (IsSubSymbol((*iter)->AsString(index), symbol_name)) {
       GOOGLE_LOG(ERROR) << "Symbol name \"" << symbol_name
                  << "\" conflicts with the existing symbol \""
-                 << (*iter)->AsString() << "\".";
+                 << (*iter)->AsString(index) << "\".";
       return false;
     }
 
@@ -635,10 +681,10 @@
     // to increment it.
     ++*iter;
 
-    if (*iter != end && IsSubSymbol(symbol_name, (*iter)->AsString())) {
+    if (*iter != end && IsSubSymbol(symbol_name, (*iter)->AsString(index))) {
       GOOGLE_LOG(ERROR) << "Symbol name \"" << symbol_name
                  << "\" conflicts with the existing symbol \""
-                 << (*iter)->AsString() << "\".";
+                 << (*iter)->AsString(index) << "\".";
       return false;
     }
   }
@@ -646,22 +692,24 @@
 }
 
 bool EncodedDescriptorDatabase::DescriptorIndex::AddSymbol(
-    StringPiece package, StringPiece symbol, Value value) {
-  SymbolEntry entry = {String(package), String(symbol), value};
-  std::string entry_as_string = entry.AsString();
+    StringPiece symbol) {
+  SymbolEntry entry = {static_cast<int>(all_values_.size() - 1),
+                       EncodeString(symbol)};
+  std::string entry_as_string = entry.AsString(*this);
 
   // We need to make sure not to violate our map invariant.
 
   // If the symbol name is invalid it could break our lookup algorithm (which
   // relies on the fact that '.' sorts before all other characters that are
   // valid in symbol names).
-  if (!ValidateSymbolName(package) || !ValidateSymbolName(symbol)) {
+  if (!ValidateSymbolName(symbol)) {
     GOOGLE_LOG(ERROR) << "Invalid symbol name: " << entry_as_string;
     return false;
   }
 
   auto iter = FindLastLessOrEqual(&by_symbol_, entry);
-  if (!CheckForMutualSubsymbols(entry_as_string, &iter, by_symbol_.end())) {
+  if (!CheckForMutualSubsymbols(entry_as_string, &iter, by_symbol_.end(),
+                                *this)) {
     return false;
   }
 
@@ -669,7 +717,7 @@
   auto flat_iter =
       FindLastLessOrEqual(&by_symbol_flat_, entry, by_symbol_.key_comp());
   if (!CheckForMutualSubsymbols(entry_as_string, &flat_iter,
-                                by_symbol_flat_.end())) {
+                                by_symbol_flat_.end(), *this)) {
     return false;
   }
 
@@ -684,25 +732,26 @@
 
 template <typename DescProto>
 bool EncodedDescriptorDatabase::DescriptorIndex::AddNestedExtensions(
-    StringPiece filename, const DescProto& message_type, Value value) {
+    StringPiece filename, const DescProto& message_type) {
   for (const auto& nested_type : message_type.nested_type()) {
-    if (!AddNestedExtensions(filename, nested_type, value)) return false;
+    if (!AddNestedExtensions(filename, nested_type)) return false;
   }
   for (const auto& extension : message_type.extension()) {
-    if (!AddExtension(filename, extension, value)) return false;
+    if (!AddExtension(filename, extension)) return false;
   }
   return true;
 }
 
 template <typename FieldProto>
 bool EncodedDescriptorDatabase::DescriptorIndex::AddExtension(
-    StringPiece filename, const FieldProto& field, Value value) {
+    StringPiece filename, const FieldProto& field) {
   if (!field.extendee().empty() && field.extendee()[0] == '.') {
     // The extension is fully-qualified.  We can use it as a lookup key in
     // the by_symbol_ table.
-    if (!InsertIfNotPresent(&by_extension_,
-                                 ExtensionEntry{field.extendee().substr(1),
-                                                field.number(), value}) ||
+    if (!InsertIfNotPresent(
+            &by_extension_,
+            ExtensionEntry{static_cast<int>(all_values_.size() - 1),
+                           EncodeString(field.extendee()), field.number()}) ||
         std::binary_search(
             by_extension_flat_.begin(), by_extension_flat_.end(),
             std::make_pair(field.extendee().substr(1), field.number()),
@@ -733,8 +782,9 @@
   auto iter =
       FindLastLessOrEqual(&by_symbol_flat_, name, by_symbol_.key_comp());
 
-  return iter != by_symbol_flat_.end() && IsSubSymbol(iter->AsString(), name)
-             ? iter->data
+  return iter != by_symbol_flat_.end() &&
+                 IsSubSymbol(iter->AsString(*this), name)
+             ? all_values_[iter->data_offset].value()
              : Value();
 }
 
@@ -746,10 +796,11 @@
   auto it = std::lower_bound(
       by_extension_flat_.begin(), by_extension_flat_.end(),
       std::make_tuple(containing_type, field_number), by_extension_.key_comp());
-  return it == by_extension_flat_.end() || it->extendee != containing_type ||
+  return it == by_extension_flat_.end() ||
+                 it->extendee(*this) != containing_type ||
                  it->extension_number != field_number
              ? std::make_pair(nullptr, 0)
-             : it->data;
+             : all_values_[it->data_offset].value();
 }
 
 template <typename T, typename Less>
@@ -763,6 +814,7 @@
 }
 
 void EncodedDescriptorDatabase::DescriptorIndex::EnsureFlat() {
+  all_values_.shrink_to_fit();
   // Merge each of the sets into their flat counterpart.
   MergeIntoFlat(&by_name_, &by_name_flat_);
   MergeIntoFlat(&by_symbol_, &by_symbol_flat_);
@@ -777,7 +829,8 @@
   auto it = std::lower_bound(
       by_extension_flat_.begin(), by_extension_flat_.end(),
       std::make_tuple(containing_type, 0), by_extension_.key_comp());
-  for (; it != by_extension_flat_.end() && it->extendee == containing_type;
+  for (;
+       it != by_extension_flat_.end() && it->extendee(*this) == containing_type;
        ++it) {
     output->push_back(it->extension_number);
     success = true;
@@ -791,11 +844,11 @@
   output->resize(by_name_.size() + by_name_flat_.size());
   int i = 0;
   for (const auto& entry : by_name_) {
-    (*output)[i] = std::string(entry.name);
+    (*output)[i] = std::string(entry.name(*this));
     i++;
   }
   for (const auto& entry : by_name_flat_) {
-    (*output)[i] = std::string(entry.name);
+    (*output)[i] = std::string(entry.name(*this));
     i++;
   }
 }
@@ -807,9 +860,9 @@
 
   auto it = std::lower_bound(by_name_flat_.begin(), by_name_flat_.end(),
                              filename, by_name_.key_comp());
-  return it == by_name_flat_.end() || it->name != filename
+  return it == by_name_flat_.end() || it->name(*this) != filename
              ? std::make_pair(nullptr, 0)
-             : it->data;
+             : all_values_[it->data_offset].value();
 }
 
 
diff --git a/src/google/protobuf/generated_enum_reflection.h b/src/google/protobuf/generated_enum_reflection.h
index 989b5a8..5debc0a 100644
--- a/src/google/protobuf/generated_enum_reflection.h
+++ b/src/google/protobuf/generated_enum_reflection.h
@@ -72,10 +72,10 @@
 // an enum name of the given type, returning true and filling in value on
 // success, or returning false and leaving value unchanged on failure.
 PROTOBUF_EXPORT bool ParseNamedEnum(const EnumDescriptor* descriptor,
-                                    StringPiece name, int* value);
+                                    ConstStringParam name, int* value);
 
 template <typename EnumType>
-bool ParseNamedEnum(const EnumDescriptor* descriptor, StringPiece name,
+bool ParseNamedEnum(const EnumDescriptor* descriptor, ConstStringParam name,
                     EnumType* value) {
   int tmp;
   if (!ParseNamedEnum(descriptor, name, &tmp)) return false;
diff --git a/src/google/protobuf/generated_message_reflection.cc b/src/google/protobuf/generated_message_reflection.cc
index be1e740..5483eda 100644
--- a/src/google/protobuf/generated_message_reflection.cc
+++ b/src/google/protobuf/generated_message_reflection.cc
@@ -82,7 +82,7 @@
 
 namespace internal {
 
-bool ParseNamedEnum(const EnumDescriptor* descriptor, StringPiece name,
+bool ParseNamedEnum(const EnumDescriptor* descriptor, ConstStringParam name,
                     int* value) {
   const EnumValueDescriptor* d = descriptor->FindValueByName(name);
   if (d == nullptr) return false;
diff --git a/src/google/protobuf/map.h b/src/google/protobuf/map.h
index 786fcf9..a1722db 100644
--- a/src/google/protobuf/map.h
+++ b/src/google/protobuf/map.h
@@ -343,8 +343,8 @@
   }
 
   ~Map() {
-    clear();
     if (arena_ == nullptr) {
+      clear();
       delete elements_;
     }
   }
@@ -1218,7 +1218,7 @@
       first = erase(first);
     }
   }
-  void clear() { erase(begin(), end()); }
+  void clear() { elements_->clear(); }
 
   // Assign
   Map& operator=(const Map& other) {
diff --git a/src/google/protobuf/message.cc b/src/google/protobuf/message.cc
index d35dfff..cfea396 100644
--- a/src/google/protobuf/message.cc
+++ b/src/google/protobuf/message.cc
@@ -171,7 +171,7 @@
 
 
 #define HASH_MAP std::unordered_map
-#define HASH_FXN hash
+#define STR_HASH_FXN hash<const char*>
 
 
 class GeneratedMessageFactory : public MessageFactory {
@@ -186,8 +186,8 @@
 
  private:
   // Only written at static init time, so does not require locking.
-  HASH_MAP<const char*, const google::protobuf::internal::DescriptorTable*,
-           HASH_FXN<const char*>, streq>
+  HASH_MAP<const char*, const google::protobuf::internal::DescriptorTable*, STR_HASH_FXN,
+           streq>
       file_map_;
 
   internal::WrappedMutex mutex_;
diff --git a/src/google/protobuf/parse_context.h b/src/google/protobuf/parse_context.h
index c0427bc..c5e3fda 100644
--- a/src/google/protobuf/parse_context.h
+++ b/src/google/protobuf/parse_context.h
@@ -744,11 +744,9 @@
     void* object, const char* ptr, ParseContext* ctx);
 
 template <typename T>
-PROTOBUF_EXPORT_TEMPLATE_DEFINE
-PROTOBUF_MUST_USE_RESULT const
-    char* PackedEnumParser(void* object, const char* ptr, ParseContext* ctx,
-                           bool (*is_valid)(int), InternalMetadata* metadata,
-                           int field_num) {
+PROTOBUF_MUST_USE_RESULT const char* PackedEnumParser(
+    void* object, const char* ptr, ParseContext* ctx, bool (*is_valid)(int),
+    InternalMetadata* metadata, int field_num) {
   return ctx->ReadPackedVarint(
       ptr, [object, is_valid, metadata, field_num](uint64 val) {
         if (is_valid(val)) {
@@ -760,12 +758,10 @@
 }
 
 template <typename T>
-PROTOBUF_EXPORT_TEMPLATE_DEFINE
-PROTOBUF_MUST_USE_RESULT const
-    char* PackedEnumParserArg(void* object, const char* ptr, ParseContext* ctx,
-                              bool (*is_valid)(const void*, int),
-                              const void* data, InternalMetadata* metadata,
-                              int field_num) {
+PROTOBUF_MUST_USE_RESULT const char* PackedEnumParserArg(
+    void* object, const char* ptr, ParseContext* ctx,
+    bool (*is_valid)(const void*, int), const void* data,
+    InternalMetadata* metadata, int field_num) {
   return ctx->ReadPackedVarint(
       ptr, [object, is_valid, data, metadata, field_num](uint64 val) {
         if (is_valid(data, val)) {
diff --git a/src/google/protobuf/port_def.inc b/src/google/protobuf/port_def.inc
index 786ff4e..c92a3d5 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -358,40 +358,40 @@
 #if defined(PROTOBUF_USE_DLLS)
   #if defined(_MSC_VER)
     #ifdef LIBPROTOBUF_EXPORTS
-      #define PROTOBUF_EXPORT __declspec(dllexport)
-      #define PROTOBUF_EXPORT_TEMPLATE_DECLARE
-      #define PROTOBUF_EXPORT_TEMPLATE_DEFINE __declspec(dllexport)
-    #else
-      #define PROTOBUF_EXPORT __declspec(dllimport)
-      #define PROTOBUF_EXPORT_TEMPLATE_DECLARE
-      #define PROTOBUF_EXPORT_TEMPLATE_DEFINE __declspec(dllimport)
-    #endif
-    #ifdef LIBPROTOC_EXPORTS
-      #define PROTOC_EXPORT __declspec(dllexport)
-    #else
-      #define PROTOC_EXPORT __declspec(dllimport)
-    #endif
-  #else  // defined(_MSC_VER)
-    #ifdef LIBPROTOBUF_EXPORTS
-      #define PROTOBUF_EXPORT __attribute__((visibility("default")))
-      #define PROTOBUF_EXPORT_TEMPLATE_DECLARE __attribute__((visibility("default")))
-      #define PROTOBUF_EXPORT_TEMPLATE_DEFINE
-    #else
-      #define PROTOBUF_EXPORT
-      #define PROTOBUF_EXPORT_TEMPLATE_DECLARE
-      #define PROTOBUF_EXPORT_TEMPLATE_DEFINE
-    #endif
-    #ifdef LIBPROTOC_EXPORTS
-      #define PROTOC_EXPORT   __attribute__((visibility("default")))
-    #else
-      #define PROTOC_EXPORT
-    #endif
-  #endif
+#define PROTOBUF_EXPORT __declspec(dllexport)
+#define PROTOBUF_EXPORT_TEMPLATE_DECLARE
+#define PROTOBUF_EXPORT_TEMPLATE_DEFINE __declspec(dllexport)
+#else
+#define PROTOBUF_EXPORT __declspec(dllimport)
+#define PROTOBUF_EXPORT_TEMPLATE_DECLARE
+#define PROTOBUF_EXPORT_TEMPLATE_DEFINE __declspec(dllimport)
+#endif
+#ifdef LIBPROTOC_EXPORTS
+#define PROTOC_EXPORT __declspec(dllexport)
+#else
+#define PROTOC_EXPORT __declspec(dllimport)
+#endif
+#else  // defined(_MSC_VER)
+#ifdef LIBPROTOBUF_EXPORTS
+#define PROTOBUF_EXPORT __attribute__((visibility("default")))
+#define PROTOBUF_EXPORT_TEMPLATE_DECLARE __attribute__((visibility("default")))
+#define PROTOBUF_EXPORT_TEMPLATE_DEFINE
+#else
+#define PROTOBUF_EXPORT
+#define PROTOBUF_EXPORT_TEMPLATE_DECLARE
+#define PROTOBUF_EXPORT_TEMPLATE_DEFINE
+#endif
+#ifdef LIBPROTOC_EXPORTS
+#define PROTOC_EXPORT __attribute__((visibility("default")))
+#else
+#define PROTOC_EXPORT
+#endif
+#endif
 #else  // defined(PROTOBUF_USE_DLLS)
   #define PROTOBUF_EXPORT
   #define PROTOC_EXPORT
-  #define PROTOBUF_EXPORT_TEMPLATE_DECLARE
-  #define PROTOBUF_EXPORT_TEMPLATE_DEFINE
+#define PROTOBUF_EXPORT_TEMPLATE_DECLARE
+#define PROTOBUF_EXPORT_TEMPLATE_DEFINE
 #endif
 
 // Windows declares several inconvenient macro names.  We #undef them and then
@@ -521,4 +521,6 @@
 // ownership of arena. However, we cannot do that for nested messages. In order
 // to tell how many usages of nested messages affected by message owned arena,
 // we need to simulate the arena ownership.
-#define PROTOBUF_MESSAGE_OWNED_ARENA_EXPERIMENT
+// This experiment is purely for the purpose of gathering data. All code guarded
+// by this flag is supposed to be removed after this experiment.
+// #define PROTOBUF_MESSAGE_OWNED_ARENA_EXPERIMENT
diff --git a/src/google/protobuf/source_context.pb.h b/src/google/protobuf/source_context.pb.h
index 4e9cb3a..c0326de 100644
--- a/src/google/protobuf/source_context.pb.h
+++ b/src/google/protobuf/source_context.pb.h
@@ -191,15 +191,6 @@
   std::string* mutable_file_name();
   std::string* release_file_name();
   void set_allocated_file_name(std::string* file_name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_file_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_file_name(
-      std::string* file_name);
   private:
   const std::string& _internal_file_name() const;
   void _internal_set_file_name(const std::string& value);
@@ -289,25 +280,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.SourceContext.file_name)
 }
-inline std::string* SourceContext::unsafe_arena_release_file_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.SourceContext.file_name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return file_name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void SourceContext::unsafe_arena_set_allocated_file_name(
-    std::string* file_name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (file_name != nullptr) {
-    
-  } else {
-    
-  }
-  file_name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      file_name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.SourceContext.file_name)
-}
 
 #ifdef __GNUC__
   #pragma GCC diagnostic pop
diff --git a/src/google/protobuf/struct.pb.h b/src/google/protobuf/struct.pb.h
index 6fe41f2..c0fdf90 100644
--- a/src/google/protobuf/struct.pb.h
+++ b/src/google/protobuf/struct.pb.h
@@ -456,15 +456,6 @@
   std::string* mutable_string_value();
   std::string* release_string_value();
   void set_allocated_string_value(std::string* string_value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_string_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_string_value(
-      std::string* string_value);
   private:
   const std::string& _internal_string_value() const;
   void _internal_set_string_value(const std::string& value);
@@ -918,29 +909,6 @@
   }
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Value.string_value)
 }
-inline std::string* Value::unsafe_arena_release_string_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Value.string_value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (_internal_has_string_value()) {
-    clear_has_kind();
-    return kind_.string_value_.UnsafeArenaRelease(
-        &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  } else {
-    return nullptr;
-  }
-}
-inline void Value::unsafe_arena_set_allocated_string_value(std::string* string_value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (!_internal_has_string_value()) {
-    kind_.string_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
-  }
-  clear_kind();
-  if (string_value) {
-    set_has_string_value();
-    kind_.string_value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), string_value, GetArena());
-  }
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Value.string_value)
-}
 
 // bool bool_value = 4;
 inline bool Value::_internal_has_bool_value() const {
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index 0fd679a..ca99dfd 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -43,9 +43,10 @@
 #include <string>
 #include <vector>
 
-#include <google/protobuf/stubs/port.h>
 #include <google/protobuf/stubs/macros.h>
 #include <google/protobuf/stubs/platform_macros.h>
+#include <google/protobuf/stubs/port.h>
+#include <google/protobuf/stubs/stringpiece.h>
 
 #ifndef PROTOBUF_USE_EXCEPTIONS
 #if defined(_MSC_VER) && defined(_CPPUNWIND)
@@ -129,12 +130,12 @@
 // structurally_valid.cc.
 PROTOBUF_EXPORT bool IsStructurallyValidUTF8(const char* buf, int len);
 
-inline bool IsStructurallyValidUTF8(const std::string& str) {
+inline bool IsStructurallyValidUTF8(StringPiece str) {
   return IsStructurallyValidUTF8(str.data(), static_cast<int>(str.length()));
 }
 
 // Returns initial number of bytes of structurally valid UTF-8.
-PROTOBUF_EXPORT int UTF8SpnStructurallyValid(const StringPiece& str);
+PROTOBUF_EXPORT int UTF8SpnStructurallyValid(StringPiece str);
 
 // Coerce UTF-8 byte string in src_str to be
 // a structurally-valid equal-length string by selectively
@@ -148,8 +149,7 @@
 //
 // Optimized for: all structurally valid and no byte copying is done.
 //
-PROTOBUF_EXPORT char* UTF8CoerceToStructurallyValid(const StringPiece& str,
-                                                    char* dst,
+PROTOBUF_EXPORT char* UTF8CoerceToStructurallyValid(StringPiece str, char* dst,
                                                     char replace_char);
 
 }  // namespace internal
diff --git a/src/google/protobuf/stubs/hash.h b/src/google/protobuf/stubs/hash.h
index a093b40..e2d2392 100644
--- a/src/google/protobuf/stubs/hash.h
+++ b/src/google/protobuf/stubs/hash.h
@@ -33,9 +33,8 @@
 #ifndef GOOGLE_PROTOBUF_STUBS_HASH_H__
 #define GOOGLE_PROTOBUF_STUBS_HASH_H__
 
-#include <string.h>
-#include <google/protobuf/stubs/common.h>
-
+#include <cstring>
+#include <string>
 #include <unordered_map>
 #include <unordered_set>
 
@@ -78,14 +77,14 @@
 };
 
 template <>
-struct hash<string> {
-  inline size_t operator()(const string& key) const {
+struct hash<std::string> {
+  inline size_t operator()(const std::string& key) const {
     return hash<const char*>()(key.c_str());
   }
 
   static const size_t bucket_size = 4;
   static const size_t min_buckets = 8;
-  inline bool operator()(const string& a, const string& b) const {
+  inline bool operator()(const std::string& a, const std::string& b) const {
     return a < b;
   }
 };
diff --git a/src/google/protobuf/stubs/stringpiece.cc b/src/google/protobuf/stubs/stringpiece.cc
index fc2f521..353c78c 100644
--- a/src/google/protobuf/stubs/stringpiece.cc
+++ b/src/google/protobuf/stubs/stringpiece.cc
@@ -64,11 +64,11 @@
   GOOGLE_DCHECK_GE(len, 0);
 }
 
-void StringPiece::CopyToString(string* target) const {
+void StringPiece::CopyToString(std::string* target) const {
   target->assign(ptr_, length_);
 }
 
-void StringPiece::AppendToString(string* target) const {
+void StringPiece::AppendToString(std::string* target) const {
   target->append(ptr_, length_);
 }
 
diff --git a/src/google/protobuf/stubs/stringpiece.h b/src/google/protobuf/stubs/stringpiece.h
index 2ae3881..fbcb20a 100644
--- a/src/google/protobuf/stubs/stringpiece.h
+++ b/src/google/protobuf/stubs/stringpiece.h
@@ -148,7 +148,6 @@
 #include <limits>
 #include <string>
 
-#include <google/protobuf/stubs/common.h>
 #include <google/protobuf/stubs/hash.h>
 
 #include <google/protobuf/port_def.inc>
@@ -165,7 +164,7 @@
 //   is 32 bits in LP32, 64 bits in LP64, 64 bits in LLP64
 //   future changes intended: http://go/64BitStringPiece
 //
-typedef string::difference_type stringpiece_ssize_type;
+typedef std::string::difference_type stringpiece_ssize_type;
 
 // STRINGPIECE_CHECK_SIZE protects us from 32-bit overflows.
 // TODO(mec): delete this after stringpiece_ssize_type goes 64 bit.
@@ -302,25 +301,21 @@
     return 0;
   }
 
-  string as_string() const {
-    return ToString();
-  }
+  std::string as_string() const { return ToString(); }
   // We also define ToString() here, since many other string-like
   // interfaces name the routine that converts to a C++ string
   // "ToString", and it's confusing to have the method that does that
   // for a StringPiece be called "as_string()".  We also leave the
   // "as_string()" method defined here for existing code.
-  string ToString() const {
-    if (ptr_ == nullptr) return string();
-    return string(data(), static_cast<size_type>(size()));
+  std::string ToString() const {
+    if (ptr_ == nullptr) return "";
+    return std::string(data(), static_cast<size_type>(size()));
   }
 
-  operator string() const {
-    return ToString();
-  }
+  explicit operator std::string() const { return ToString(); }
 
-  void CopyToString(string* target) const;
-  void AppendToString(string* target) const;
+  void CopyToString(std::string* target) const;
+  void AppendToString(std::string* target) const;
 
   bool starts_with(StringPiece x) const {
     return (length_ >= x.length_) &&
@@ -466,7 +461,7 @@
     return std::string(data_, static_cast<size_t>(size_));
   }
 
-  operator string() const { return ToString(); }
+  explicit operator std::string() const { return ToString(); }
 
  private:
   const char* data_;
diff --git a/src/google/protobuf/stubs/structurally_valid.cc b/src/google/protobuf/stubs/structurally_valid.cc
index 4d424a1..9a476c3 100644
--- a/src/google/protobuf/stubs/structurally_valid.cc
+++ b/src/google/protobuf/stubs/structurally_valid.cc
@@ -561,7 +561,7 @@
   return (bytes_consumed == len);
 }
 
-int UTF8SpnStructurallyValid(const StringPiece& str) {
+int UTF8SpnStructurallyValid(StringPiece str) {
   if (!module_initialized_) return str.size();
 
   int bytes_consumed = 0;
@@ -582,8 +582,7 @@
 //
 // Fast case: all is structurally valid and no byte copying is done.
 //
-char* UTF8CoerceToStructurallyValid(const StringPiece& src_str,
-                                    char* idst,
+char* UTF8CoerceToStructurallyValid(StringPiece src_str, char* idst,
                                     const char replace_char) {
   const char* isrc = src_str.data();
   const int len = src_str.length();
diff --git a/src/google/protobuf/stubs/strutil.cc b/src/google/protobuf/stubs/strutil.cc
index 24ae286..2722594 100644
--- a/src/google/protobuf/stubs/strutil.cc
+++ b/src/google/protobuf/stubs/strutil.cc
@@ -176,10 +176,8 @@
 // the characters in the string, not the entire string as a single delimiter.
 // ----------------------------------------------------------------------
 template <typename ITR>
-static inline
-void SplitStringToIteratorUsing(const string& full,
-                                const char* delim,
-                                ITR& result) {
+static inline void SplitStringToIteratorUsing(StringPiece full,
+                                              const char *delim, ITR &result) {
   // Optimize the common case where delim is a single character.
   if (delim[0] != '\0' && delim[1] == '\0') {
     char c = delim[0];
@@ -191,7 +189,7 @@
       } else {
         const char* start = p;
         while (++p != end && *p != c);
-        *result++ = string(start, p - start);
+        *result++ = std::string(start, p - start);
       }
     }
     return;
@@ -202,17 +200,17 @@
   while (begin_index != string::npos) {
     end_index = full.find_first_of(delim, begin_index);
     if (end_index == string::npos) {
-      *result++ = full.substr(begin_index);
+      *result++ = std::string(full.substr(begin_index));
       return;
     }
-    *result++ = full.substr(begin_index, (end_index - begin_index));
+    *result++ =
+        std::string(full.substr(begin_index, (end_index - begin_index)));
     begin_index = full.find_first_not_of(delim, end_index);
   }
 }
 
-void SplitStringUsing(const string& full,
-                      const char* delim,
-                      std::vector<string>* result) {
+void SplitStringUsing(StringPiece full, const char *delim,
+                      std::vector<string> *result) {
   std::back_insert_iterator< std::vector<string> > it(*result);
   SplitStringToIteratorUsing(full, delim, it);
 }
@@ -228,29 +226,28 @@
 //
 // If "pieces" is negative for some reason, it returns the whole string
 // ----------------------------------------------------------------------
-template <typename StringType, typename ITR>
-static inline
-void SplitStringToIteratorAllowEmpty(const StringType& full,
-                                     const char* delim,
-                                     int pieces,
-                                     ITR& result) {
+template <typename ITR>
+static inline void SplitStringToIteratorAllowEmpty(StringPiece full,
+                                                   const char *delim,
+                                                   int pieces, ITR &result) {
   string::size_type begin_index, end_index;
   begin_index = 0;
 
   for (int i = 0; (i < pieces-1) || (pieces == 0); i++) {
     end_index = full.find_first_of(delim, begin_index);
     if (end_index == string::npos) {
-      *result++ = full.substr(begin_index);
+      *result++ = std::string(full.substr(begin_index));
       return;
     }
-    *result++ = full.substr(begin_index, (end_index - begin_index));
+    *result++ =
+        std::string(full.substr(begin_index, (end_index - begin_index)));
     begin_index = end_index + 1;
   }
-  *result++ = full.substr(begin_index);
+  *result++ = std::string(full.substr(begin_index));
 }
 
-void SplitStringAllowEmpty(const string& full, const char* delim,
-                           std::vector<string>* result) {
+void SplitStringAllowEmpty(StringPiece full, const char *delim,
+                           std::vector<string> *result) {
   std::back_insert_iterator<std::vector<string> > it(*result);
   SplitStringToIteratorAllowEmpty(full, delim, 0, it);
 }
diff --git a/src/google/protobuf/stubs/strutil.h b/src/google/protobuf/stubs/strutil.h
index 981cb6e..c070a05 100644
--- a/src/google/protobuf/stubs/strutil.h
+++ b/src/google/protobuf/stubs/strutil.h
@@ -113,12 +113,6 @@
 //    prefix string if the prefix matches, otherwise the original
 //    string.
 // ----------------------------------------------------------------------
-inline bool HasPrefixString(const string& str,
-                            const string& prefix) {
-  return str.size() >= prefix.size() &&
-         str.compare(0, prefix.size(), prefix) == 0;
-}
-
 inline bool HasPrefixString(StringPiece str, StringPiece prefix) {
   return str.size() >= prefix.size() &&
          memcmp(str.data(), prefix.data(), prefix.size()) == 0;
@@ -140,10 +134,10 @@
 //    suffix string if the suffix matches, otherwise the original
 //    string.
 // ----------------------------------------------------------------------
-inline bool HasSuffixString(const string& str,
-                            const string& suffix) {
+inline bool HasSuffixString(StringPiece str, StringPiece suffix) {
   return str.size() >= suffix.size() &&
-         str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0;
+         memcmp(str.data() + str.size() - suffix.size(), suffix.data(),
+                suffix.size()) == 0;
 }
 
 inline string StripSuffixString(const string& str, const string& suffix) {
@@ -219,7 +213,7 @@
 //    to 'result'.  If there are consecutive delimiters, this function skips
 //    over all of them.
 // ----------------------------------------------------------------------
-PROTOBUF_EXPORT void SplitStringUsing(const string& full, const char* delim,
+PROTOBUF_EXPORT void SplitStringUsing(StringPiece full, const char* delim,
                                       std::vector<string>* res);
 
 // Split a string using one or more byte delimiters, presented
@@ -230,16 +224,15 @@
 //
 // If "full" is the empty string, yields an empty string as the only value.
 // ----------------------------------------------------------------------
-PROTOBUF_EXPORT void SplitStringAllowEmpty(const string& full,
-                                           const char* delim,
+PROTOBUF_EXPORT void SplitStringAllowEmpty(StringPiece full, const char* delim,
                                            std::vector<string>* result);
 
 // ----------------------------------------------------------------------
 // Split()
 //    Split a string using a character delimiter.
 // ----------------------------------------------------------------------
-inline std::vector<string> Split(
-    const string& full, const char* delim, bool skip_empty = true) {
+inline std::vector<string> Split(StringPiece full, const char* delim,
+                                 bool skip_empty = true) {
   std::vector<string> result;
   if (skip_empty) {
     SplitStringUsing(full, delim, &result);
diff --git a/src/google/protobuf/type.pb.h b/src/google/protobuf/type.pb.h
index 0d149f7..ea57370 100644
--- a/src/google/protobuf/type.pb.h
+++ b/src/google/protobuf/type.pb.h
@@ -369,15 +369,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -679,15 +670,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -704,15 +686,6 @@
   std::string* mutable_type_url();
   std::string* release_type_url();
   void set_allocated_type_url(std::string* type_url);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_type_url();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_type_url(
-      std::string* type_url);
   private:
   const std::string& _internal_type_url() const;
   void _internal_set_type_url(const std::string& value);
@@ -729,15 +702,6 @@
   std::string* mutable_json_name();
   std::string* release_json_name();
   void set_allocated_json_name(std::string* json_name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_json_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_json_name(
-      std::string* json_name);
   private:
   const std::string& _internal_json_name() const;
   void _internal_set_json_name(const std::string& value);
@@ -754,15 +718,6 @@
   std::string* mutable_default_value();
   std::string* release_default_value();
   void set_allocated_default_value(std::string* default_value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_default_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_default_value(
-      std::string* default_value);
   private:
   const std::string& _internal_default_value() const;
   void _internal_set_default_value(const std::string& value);
@@ -1001,15 +956,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -1205,15 +1151,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -1370,15 +1307,6 @@
   std::string* mutable_name();
   std::string* release_name();
   void set_allocated_name(std::string* name);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_name();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_name(
-      std::string* name);
   private:
   const std::string& _internal_name() const;
   void _internal_set_name(const std::string& value);
@@ -1487,25 +1415,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Type.name)
 }
-inline std::string* Type::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Type.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Type::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Type.name)
-}
 
 // repeated .google.protobuf.Field fields = 2;
 inline int Type::_internal_fields_size() const {
@@ -1881,25 +1790,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.name)
 }
-inline std::string* Field::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Field.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Field::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Field.name)
-}
 
 // string type_url = 6;
 inline void Field::clear_type_url() {
@@ -1962,25 +1852,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.type_url)
 }
-inline std::string* Field::unsafe_arena_release_type_url() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Field.type_url)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return type_url_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Field::unsafe_arena_set_allocated_type_url(
-    std::string* type_url) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (type_url != nullptr) {
-    
-  } else {
-    
-  }
-  type_url_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      type_url, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Field.type_url)
-}
 
 // int32 oneof_index = 7;
 inline void Field::clear_oneof_index() {
@@ -2122,25 +1993,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.json_name)
 }
-inline std::string* Field::unsafe_arena_release_json_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Field.json_name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return json_name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Field::unsafe_arena_set_allocated_json_name(
-    std::string* json_name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (json_name != nullptr) {
-    
-  } else {
-    
-  }
-  json_name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      json_name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Field.json_name)
-}
 
 // string default_value = 11;
 inline void Field::clear_default_value() {
@@ -2203,25 +2055,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.default_value)
 }
-inline std::string* Field::unsafe_arena_release_default_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Field.default_value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return default_value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Field::unsafe_arena_set_allocated_default_value(
-    std::string* default_value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (default_value != nullptr) {
-    
-  } else {
-    
-  }
-  default_value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      default_value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Field.default_value)
-}
 
 // -------------------------------------------------------------------
 
@@ -2288,25 +2121,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Enum.name)
 }
-inline std::string* Enum::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Enum.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Enum::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Enum.name)
-}
 
 // repeated .google.protobuf.EnumValue enumvalue = 2;
 inline int Enum::_internal_enumvalue_size() const {
@@ -2548,25 +2362,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.EnumValue.name)
 }
-inline std::string* EnumValue::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.EnumValue.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void EnumValue::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.EnumValue.name)
-}
 
 // int32 number = 2;
 inline void EnumValue::clear_number() {
@@ -2692,25 +2487,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Option.name)
 }
-inline std::string* Option::unsafe_arena_release_name() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.Option.name)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return name_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void Option::unsafe_arena_set_allocated_name(
-    std::string* name) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (name != nullptr) {
-    
-  } else {
-    
-  }
-  name_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      name, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.Option.name)
-}
 
 // .google.protobuf.Any value = 2;
 inline bool Option::_internal_has_value() const {
diff --git a/src/google/protobuf/util/field_mask_util.h b/src/google/protobuf/util/field_mask_util.h
index cc2148d..3ca9359 100644
--- a/src/google/protobuf/util/field_mask_util.h
+++ b/src/google/protobuf/util/field_mask_util.h
@@ -106,7 +106,7 @@
   template <typename T>
   static void AddPathToFieldMask(StringPiece path, FieldMask* mask) {
     GOOGLE_CHECK(IsValidPath<T>(path)) << path;
-    mask->add_paths(path);
+    mask->add_paths(std::string(path));
   }
 
   // Creates a FieldMask with all fields of type T. This FieldMask only
diff --git a/src/google/protobuf/util/internal/expecting_objectwriter.h b/src/google/protobuf/util/internal/expecting_objectwriter.h
index 71ecb1d..2cb7f69 100644
--- a/src/google/protobuf/util/internal/expecting_objectwriter.h
+++ b/src/google/protobuf/util/internal/expecting_objectwriter.h
@@ -60,6 +60,7 @@
 namespace util {
 namespace converter {
 
+using testing::Eq;
 using testing::IsEmpty;
 using testing::NanSensitiveDoubleEq;
 using testing::NanSensitiveFloatEq;
@@ -100,7 +101,7 @@
 
   virtual ObjectWriter* StartObject(StringPiece name) {
     (name.empty() ? EXPECT_CALL(*mock_, StartObject(IsEmpty()))
-                  : EXPECT_CALL(*mock_, StartObject(StrEq(std::string(name)))))
+                  : EXPECT_CALL(*mock_, StartObject(Eq(std::string(name)))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
     return this;
@@ -115,7 +116,7 @@
 
   virtual ObjectWriter* StartList(StringPiece name) {
     (name.empty() ? EXPECT_CALL(*mock_, StartList(IsEmpty()))
-                  : EXPECT_CALL(*mock_, StartList(StrEq(std::string(name)))))
+                  : EXPECT_CALL(*mock_, StartList(Eq(std::string(name)))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
     return this;
@@ -131,8 +132,8 @@
   virtual ObjectWriter* RenderBool(StringPiece name, bool value) {
     (name.empty()
          ? EXPECT_CALL(*mock_, RenderBool(IsEmpty(), TypedEq<bool>(value)))
-         : EXPECT_CALL(*mock_, RenderBool(StrEq(std::string(name)),
-                                          TypedEq<bool>(value))))
+         : EXPECT_CALL(*mock_,
+                       RenderBool(Eq(std::string(name)), TypedEq<bool>(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
     return this;
@@ -141,7 +142,7 @@
   virtual ObjectWriter* RenderInt32(StringPiece name, int32 value) {
     (name.empty()
          ? EXPECT_CALL(*mock_, RenderInt32(IsEmpty(), TypedEq<int32>(value)))
-         : EXPECT_CALL(*mock_, RenderInt32(StrEq(std::string(name)),
+         : EXPECT_CALL(*mock_, RenderInt32(Eq(std::string(name)),
                                            TypedEq<int32>(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -151,7 +152,7 @@
   virtual ObjectWriter* RenderUint32(StringPiece name, uint32 value) {
     (name.empty()
          ? EXPECT_CALL(*mock_, RenderUint32(IsEmpty(), TypedEq<uint32>(value)))
-         : EXPECT_CALL(*mock_, RenderUint32(StrEq(std::string(name)),
+         : EXPECT_CALL(*mock_, RenderUint32(Eq(std::string(name)),
                                             TypedEq<uint32>(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -161,7 +162,7 @@
   virtual ObjectWriter* RenderInt64(StringPiece name, int64 value) {
     (name.empty()
          ? EXPECT_CALL(*mock_, RenderInt64(IsEmpty(), TypedEq<int64>(value)))
-         : EXPECT_CALL(*mock_, RenderInt64(StrEq(std::string(name)),
+         : EXPECT_CALL(*mock_, RenderInt64(Eq(std::string(name)),
                                            TypedEq<int64>(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -171,7 +172,7 @@
   virtual ObjectWriter* RenderUint64(StringPiece name, uint64 value) {
     (name.empty()
          ? EXPECT_CALL(*mock_, RenderUint64(IsEmpty(), TypedEq<uint64>(value)))
-         : EXPECT_CALL(*mock_, RenderUint64(StrEq(std::string(name)),
+         : EXPECT_CALL(*mock_, RenderUint64(Eq(std::string(name)),
                                             TypedEq<uint64>(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -182,7 +183,7 @@
     (name.empty()
          ? EXPECT_CALL(*mock_,
                        RenderDouble(IsEmpty(), NanSensitiveDoubleEq(value)))
-         : EXPECT_CALL(*mock_, RenderDouble(StrEq(std::string(name)),
+         : EXPECT_CALL(*mock_, RenderDouble(Eq(std::string(name)),
                                             NanSensitiveDoubleEq(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -193,7 +194,7 @@
     (name.empty()
          ? EXPECT_CALL(*mock_,
                        RenderFloat(IsEmpty(), NanSensitiveFloatEq(value)))
-         : EXPECT_CALL(*mock_, RenderFloat(StrEq(std::string(name)),
+         : EXPECT_CALL(*mock_, RenderFloat(Eq(std::string(name)),
                                            NanSensitiveFloatEq(value))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -205,7 +206,7 @@
     (name.empty() ? EXPECT_CALL(*mock_, RenderString(IsEmpty(),
                                                      TypedEq<StringPiece>(
                                                          std::string(value))))
-                  : EXPECT_CALL(*mock_, RenderString(StrEq(std::string(name)),
+                  : EXPECT_CALL(*mock_, RenderString(Eq(std::string(name)),
                                                      TypedEq<StringPiece>(
                                                          std::string(value)))))
         .WillOnce(Return(mock_))
@@ -217,7 +218,7 @@
          ? EXPECT_CALL(*mock_, RenderBytes(IsEmpty(), TypedEq<StringPiece>(
                                                           value.ToString())))
          : EXPECT_CALL(*mock_,
-                       RenderBytes(StrEq(name.ToString()),
+                       RenderBytes(Eq(std::string(name)),
                                    TypedEq<StringPiece>(value.ToString()))))
         .WillOnce(Return(mock_))
         .RetiresOnSaturation();
@@ -226,7 +227,7 @@
 
   virtual ObjectWriter* RenderNull(StringPiece name) {
     (name.empty() ? EXPECT_CALL(*mock_, RenderNull(IsEmpty()))
-                  : EXPECT_CALL(*mock_, RenderNull(StrEq(std::string(name))))
+                  : EXPECT_CALL(*mock_, RenderNull(Eq(std::string(name))))
                         .WillOnce(Return(mock_))
                         .RetiresOnSaturation());
     return this;
diff --git a/src/google/protobuf/wrappers.pb.h b/src/google/protobuf/wrappers.pb.h
index 5a195bb..d6ee3fc 100644
--- a/src/google/protobuf/wrappers.pb.h
+++ b/src/google/protobuf/wrappers.pb.h
@@ -1182,15 +1182,6 @@
   std::string* mutable_value();
   std::string* release_value();
   void set_allocated_value(std::string* value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_value(
-      std::string* value);
   private:
   const std::string& _internal_value() const;
   void _internal_set_value(const std::string& value);
@@ -1335,15 +1326,6 @@
   std::string* mutable_value();
   std::string* release_value();
   void set_allocated_value(std::string* value);
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  std::string* unsafe_arena_release_value();
-  GOOGLE_PROTOBUF_RUNTIME_DEPRECATED("The unsafe_arena_ accessors for"
-  "    string fields are deprecated and will be removed in a"
-  "    future release.")
-  void unsafe_arena_set_allocated_value(
-      std::string* value);
   private:
   const std::string& _internal_value() const;
   void _internal_set_value(const std::string& value);
@@ -1601,25 +1583,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.StringValue.value)
 }
-inline std::string* StringValue::unsafe_arena_release_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.StringValue.value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void StringValue::unsafe_arena_set_allocated_value(
-    std::string* value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (value != nullptr) {
-    
-  } else {
-    
-  }
-  value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.StringValue.value)
-}
 
 // -------------------------------------------------------------------
 
@@ -1686,25 +1649,6 @@
       GetArena());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.BytesValue.value)
 }
-inline std::string* BytesValue::unsafe_arena_release_value() {
-  // @@protoc_insertion_point(field_unsafe_arena_release:google.protobuf.BytesValue.value)
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  
-  return value_.UnsafeArenaRelease(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      GetArena());
-}
-inline void BytesValue::unsafe_arena_set_allocated_value(
-    std::string* value) {
-  GOOGLE_DCHECK(GetArena() != nullptr);
-  if (value != nullptr) {
-    
-  } else {
-    
-  }
-  value_.UnsafeArenaSetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
-      value, GetArena());
-  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:google.protobuf.BytesValue.value)
-}
 
 #ifdef __GNUC__
   #pragma GCC diagnostic pop