Merge pull request #8546 from haberman/sync-stage

Integrate from Piper for C++, Java, and Python

CHANGES.txt

@@ -1,15 +1,27 @@
 
 Unreleased Changes (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
 
+  Protocol Compiler
+  * Fix the generated source information for reserved values in Enums.
+
   C++
   * Fix bug where `Descriptor::DebugString()` printed proto3 synthetic oneofs.
   * Provide stable versions of `SortAndUnique()`.
   * Make sure to cache proto3 optional message fields when they are cleared.
   * Expose UnsafeArena methods to Reflection.
+  * Use std::string::empty() rather than std::string::size() > 0.
 
   Kotlin
   * Restrict extension setter and getter operators to non-nullable T.
 
+  Java
+  * Reduce the time spent evaluating isExtensionNumber by storing the extension
+    ranges in a TreeMap for faster queries. This is particularly relevant for
+    protos which define a large number of extension ranges, for example when
+    each tag is defined as an extension.
+  * Fix java bytecode estimation logic for optional fields.
+  * Optimize Descriptor.isExtensionNumber.
+
   Python
   * Make JSON parsing match C++ and Java when multiple fields from the same
     oneof are present and all but one is null.

csharp/src/AddressBook/Addressbook.cs

@@ -32,9 +32,9 @@ namespace Google.Protobuf.Examples.AddressBook {
             "Eg4KBm51bWJlchgBIAEoCRIoCgR0eXBlGAIgASgOMhoudHV0b3JpYWwuUGVy",
             "c29uLlBob25lVHlwZSIrCglQaG9uZVR5cGUSCgoGTU9CSUxFEAASCAoESE9N",
             "RRABEggKBFdPUksQAiIvCgtBZGRyZXNzQm9vaxIgCgZwZW9wbGUYASADKAsy",
-            "EC50dXRvcmlhbC5QZXJzb25CWQobY29tLmV4YW1wbGUudHV0b3JpYWwucHJv",
-            "dG9zQhFBZGRyZXNzQm9va1Byb3Rvc1ABqgIkR29vZ2xlLlByb3RvYnVmLkV4",
-            "YW1wbGVzLkFkZHJlc3NCb29rYgZwcm90bzM="));
+            "EC50dXRvcmlhbC5QZXJzb25CZgobY29tLmV4YW1wbGUudHV0b3JpYWwucHJv",
+            "dG9zQhFBZGRyZXNzQm9va1Byb3Rvc1ABWgsuLi90dXRvcmlhbKoCJEdvb2ds",
+            "ZS5Qcm90b2J1Zi5FeGFtcGxlcy5BZGRyZXNzQm9va2IGcHJvdG8z"));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { global::Google.Protobuf.WellKnownTypes.TimestampReflection.Descriptor, },
           new pbr::GeneratedClrTypeInfo(null, null, new pbr::GeneratedClrTypeInfo[] {

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

@@ -724,12 +724,12 @@ public final class Descriptors {
 
     /** Determines if the given field number is an extension. */
     public boolean isExtensionNumber(final int number) {
-      for (final DescriptorProto.ExtensionRange range : proto.getExtensionRangeList()) {
-        if (range.getStart() <= number && number < range.getEnd()) {
-          return true;
-        }
+      int index = Arrays.binarySearch(extensionRangeLowerBounds, number);
+      if (index < 0) {
+        index = ~index - 1;
       }
-      return false;
+      // extensionRangeLowerBounds[index] is the biggest value <= number
+      return index >= 0 && number < extensionRangeUpperBounds[index];
     }
 
     /** Determines if the given field number is reserved. */
@@ -831,6 +831,9 @@ public final class Descriptors {
     private final OneofDescriptor[] oneofs;
     private final int realOneofCount;
 
+    private final int[] extensionRangeLowerBounds;
+    private final int[] extensionRangeUpperBounds;
+
     // Used to create a placeholder when the type cannot be found.
     Descriptor(final String fullname) throws DescriptorValidationException {
       String name = fullname;
@@ -859,6 +862,9 @@ public final class Descriptors {
 
       // Create a placeholder FileDescriptor to hold this message.
       this.file = new FileDescriptor(packageName, this);
+
+      extensionRangeLowerBounds = new int[] {1};
+      extensionRangeUpperBounds = new int[] {536870912};
     }
 
     private Descriptor(
@@ -922,6 +928,20 @@ public final class Descriptors {
       this.realOneofCount = this.oneofs.length - syntheticOneofCount;
 
       file.pool.addSymbol(this);
+
+      // NOTE: The defined extension ranges are guaranteed to be disjoint.
+      extensionRangeLowerBounds = new int[proto.getExtensionRangeCount()];
+      extensionRangeUpperBounds = new int[proto.getExtensionRangeCount()];
+      int i = 0;
+      for (final DescriptorProto.ExtensionRange range : proto.getExtensionRangeList()) {
+        extensionRangeLowerBounds[i] = range.getStart();
+        extensionRangeUpperBounds[i] = range.getEnd();
+        i++;
+      }
+      // Since the ranges are disjoint, sorting these independently must still produce the correct
+      // order.
+      Arrays.sort(extensionRangeLowerBounds);
+      Arrays.sort(extensionRangeUpperBounds);
     }
 
     /** Look up and cross-link all field types, etc. */

java/core/src/test/java/com/google/protobuf/DescriptorsTest.java

@@ -804,4 +804,8 @@ public class DescriptorsTest extends TestCase {
             .build();
     assertEquals(8, msg.getExtension(NestedExtension.MyNestedExtension.default_).intValue());
   }
+
+  public void testDefaultDescriptorExtensionRange() throws Exception {
+    assertTrue(new Descriptor("default").isExtensionNumber(1));
+  }
 }

js/compatibility_tests/v3.1.0/binary/decoder_test.js

@@ -224,7 +224,6 @@ describe('binaryDecoderTest', function() {
 
   /**
    * Verifies that misuse of the decoder class triggers assertions.
-   * @suppress {checkTypes|visibility}
    */
   it('testDecodeErrors', function() {
     // Reading a value past the end of the stream should trigger an assertion.

python/google/protobuf/descriptor.py

@@ -912,7 +912,7 @@ class MethodDescriptor(DescriptorBase):
     self.containing_service = containing_service
     self.input_type = input_type
     self.output_type = output_type
-  
+
   def CopyToProto(self, proto):
     """Copies this to a descriptor_pb2.MethodDescriptorProto.
 

python/google/protobuf/internal/proto_builder_test.py

@@ -42,6 +42,7 @@ except ImportError:
   import unittest
 
 from google.protobuf import descriptor_pb2
+from google.protobuf import descriptor
 from google.protobuf import descriptor_pool
 from google.protobuf import proto_builder
 from google.protobuf import text_format
@@ -91,6 +92,23 @@ class ProtoBuilderTest(unittest.TestCase):
         pool=pool)
     self.assertIs(proto_cls1.DESCRIPTOR, proto_cls2.DESCRIPTOR)
 
+  def testMakeLargeProtoClass(self):
+    """Test that large created protos don't use reserved field numbers."""
+    num_fields = 123456
+    fields = {
+        'foo%d' % i: descriptor_pb2.FieldDescriptorProto.TYPE_INT64
+        for i in range(num_fields)
+    }
+    proto_cls = proto_builder.MakeSimpleProtoClass(
+        fields,
+        full_name='net.proto2.python.public.proto_builder_test.LargeProtoTest')
+
+    reserved_field_numbers = set(
+        range(descriptor.FieldDescriptor.FIRST_RESERVED_FIELD_NUMBER,
+              descriptor.FieldDescriptor.LAST_RESERVED_FIELD_NUMBER + 1))
+    proto_field_numbers = set(proto_cls.DESCRIPTOR.fields_by_number)
+    self.assertFalse(reserved_field_numbers.intersection(proto_field_numbers))
+
 
 if __name__ == '__main__':
   unittest.main()

python/google/protobuf/proto_builder.py

@@ -31,13 +31,14 @@
 """Dynamic Protobuf class creator."""
 
 try:
-    from collections import OrderedDict
+  from collections import OrderedDict
 except ImportError:
-    from ordereddict import OrderedDict  #PY26
+  from ordereddict import OrderedDict  #PY26
 import hashlib
 import os
 
 from google.protobuf import descriptor_pb2
+from google.protobuf import descriptor
 from google.protobuf import message_factory
 
 
@@ -124,6 +125,12 @@ def _MakeFileDescriptorProto(proto_file_name, full_name, field_items):
   for f_number, (f_name, f_type) in enumerate(field_items, 1):
     field_proto = desc_proto.field.add()
     field_proto.name = f_name
+    # # If the number falls in the reserved range, reassign it to the correct
+    # # number after the range.
+    if f_number >= descriptor.FieldDescriptor.FIRST_RESERVED_FIELD_NUMBER:
+      f_number += (
+          descriptor.FieldDescriptor.LAST_RESERVED_FIELD_NUMBER -
+          descriptor.FieldDescriptor.FIRST_RESERVED_FIELD_NUMBER + 1)
     field_proto.number = f_number
     field_proto.label = descriptor_pb2.FieldDescriptorProto.LABEL_OPTIONAL
     field_proto.type = f_type

python/google/protobuf/pyext/repeated_composite_container.cc

@@ -379,16 +379,19 @@ static void ReorderAttached(RepeatedCompositeContainer* self,
   const FieldDescriptor* descriptor = self->parent_field_descriptor;
   const Py_ssize_t length = Length(reinterpret_cast<PyObject*>(self));
 
-  // Since Python protobuf objects are never arena-allocated, adding and
-  // removing message pointers to the underlying array is just updating
-  // pointers.
-  for (Py_ssize_t i = 0; i < length; ++i)
-    reflection->ReleaseLast(message, descriptor);
-
+  // We need to rearrange things to match python's sort order.  Because there
+  // was already an O(n*log(n)) step in python and a bunch of reflection, we
+  // expect an O(n**2) step in C++ won't hurt too much.
   for (Py_ssize_t i = 0; i < length; ++i) {
-    CMessage* py_cmsg = reinterpret_cast<CMessage*>(
-        PyList_GET_ITEM(child_list, i));
-    reflection->AddAllocatedMessage(message, descriptor, py_cmsg->message);
+    Message* child_message =
+        reinterpret_cast<CMessage*>(PyList_GET_ITEM(child_list, i))->message;
+    for (Py_ssize_t j = i; j < length; ++j) {
+      if (child_message ==
+          &reflection->GetRepeatedMessage(*message, descriptor, j)) {
+        reflection->SwapElements(message, descriptor, i, j);
+        break;
+      }
+    }
   }
 }
 

src/google/protobuf/any.pb.cc

@@ -110,12 +110,12 @@ Any::Any(const Any& from)
   type_url_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_type_url().empty()) {
     type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_type_url(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_value().empty()) {
     value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   // @@protoc_insertion_point(copy_constructor:google.protobuf.Any)
 }
@@ -132,7 +132,7 @@ Any::~Any() {
 }
 
 void Any::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   type_url_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   value_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
@@ -211,7 +211,7 @@ failure:
   (void) cached_has_bits;
 
   // string type_url = 1;
-  if (this->type_url().size() > 0) {
+  if (!this->type_url().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_type_url().data(), static_cast<int>(this->_internal_type_url().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -221,7 +221,7 @@ failure:
   }
 
   // bytes value = 2;
-  if (this->value().size() > 0) {
+  if (!this->value().empty()) {
     target = stream->WriteBytesMaybeAliased(
         2, this->_internal_value(), target);
   }
@@ -243,14 +243,14 @@ size_t Any::ByteSizeLong() const {
   (void) cached_has_bits;
 
   // string type_url = 1;
-  if (this->type_url().size() > 0) {
+  if (!this->type_url().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_type_url());
   }
 
   // bytes value = 2;
-  if (this->value().size() > 0) {
+  if (!this->value().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::BytesSize(
         this->_internal_value());
@@ -287,10 +287,10 @@ void Any::MergeFrom(const Any& from) {
   ::PROTOBUF_NAMESPACE_ID::uint32 cached_has_bits = 0;
   (void) cached_has_bits;
 
-  if (from.type_url().size() > 0) {
+  if (!from.type_url().empty()) {
     _internal_set_type_url(from._internal_type_url());
   }
-  if (from.value().size() > 0) {
+  if (!from.value().empty()) {
     _internal_set_value(from._internal_value());
   }
 }
@@ -316,8 +316,16 @@ bool Any::IsInitialized() const {
 void Any::InternalSwap(Any* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
-  type_url_.Swap(&other->type_url_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  value_.Swap(&other->value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &type_url_, GetArenaForAllocation(),
+      &other->type_url_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &value_, GetArenaForAllocation(),
+      &other->value_, other->GetArenaForAllocation()
+  );
 }
 
 ::PROTOBUF_NAMESPACE_ID::Metadata Any::GetMetadata() const {

src/google/protobuf/any.pb.h

@@ -65,7 +65,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Any final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Any) */ {
  public:
   inline Any() : Any(nullptr) {}
@@ -83,8 +83,9 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
     return *this;
   }
   inline Any& operator=(Any&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -148,7 +149,7 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
   }
   inline void Swap(Any* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -156,14 +157,14 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Any* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Any* New() const final {
-    return CreateMaybeMessage<Any>(nullptr);
+    return new Any();
   }
 
   Any* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -214,11 +215,11 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_type_url(ArgT0&& arg0, ArgT... args);
   std::string* mutable_type_url();
-  std::string* release_type_url();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_type_url();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_type_url(const std::string& value);
   std::string* _internal_mutable_type_url();
   public:
 
@@ -228,11 +229,11 @@ class PROTOBUF_EXPORT Any PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_value(ArgT0&& arg0, ArgT... args);
   std::string* mutable_value();
-  std::string* release_value();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_value();
   void set_allocated_value(std::string* value);
   private:
   const std::string& _internal_value() const;
-  void _internal_set_value(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_value(const std::string& value);
   std::string* _internal_mutable_value();
   public:
 
@@ -269,10 +270,10 @@ inline const std::string& Any::type_url() const {
   return _internal_type_url();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Any::set_type_url(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Any::set_type_url(ArgT0&& arg0, ArgT... args) {
  
- type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Any.type_url)
 }
 inline std::string* Any::mutable_type_url() {
@@ -284,15 +285,15 @@ inline const std::string& Any::_internal_type_url() const {
 }
 inline void Any::_internal_set_type_url(const std::string& value) {
   
-  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Any::_internal_mutable_type_url() {
   
-  return type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Any::release_type_url() {
   // @@protoc_insertion_point(field_release:google.protobuf.Any.type_url)
-  return type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Any::set_allocated_type_url(std::string* type_url) {
   if (type_url != nullptr) {
@@ -301,7 +302,7 @@ inline void Any::set_allocated_type_url(std::string* type_url) {
     
   }
   type_url_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), type_url,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Any.type_url)
 }
 
@@ -314,10 +315,10 @@ inline const std::string& Any::value() const {
   return _internal_value();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Any::set_value(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Any::set_value(ArgT0&& arg0, ArgT... args) {
  
- value_.SetBytes(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ value_.SetBytes(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Any.value)
 }
 inline std::string* Any::mutable_value() {
@@ -329,15 +330,15 @@ inline const std::string& Any::_internal_value() const {
 }
 inline void Any::_internal_set_value(const std::string& value) {
   
-  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Any::_internal_mutable_value() {
   
-  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Any::release_value() {
   // @@protoc_insertion_point(field_release:google.protobuf.Any.value)
-  return value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Any::set_allocated_value(std::string* value) {
   if (value != nullptr) {
@@ -346,7 +347,7 @@ inline void Any::set_allocated_value(std::string* value) {
     
   }
   value_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), value,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Any.value)
 }
 

src/google/protobuf/api.pb.cc

@@ -173,7 +173,7 @@ void Api::clear_options() {
   options_.Clear();
 }
 void Api::clear_source_context() {
-  if (GetArena() == nullptr && source_context_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && source_context_ != nullptr) {
     delete source_context_;
   }
   source_context_ = nullptr;
@@ -196,12 +196,12 @@ Api::Api(const Api& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   version_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_version().empty()) {
     version_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_version(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_source_context()) {
     source_context_ = new PROTOBUF_NAMESPACE_ID::SourceContext(*from.source_context_);
@@ -228,7 +228,7 @@ Api::~Api() {
 }
 
 void Api::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   version_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete source_context_;
@@ -255,7 +255,7 @@ void Api::Clear() {
   mixins_.Clear();
   name_.ClearToEmpty();
   version_.ClearToEmpty();
-  if (GetArena() == nullptr && source_context_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && source_context_ != nullptr) {
     delete source_context_;
   }
   source_context_ = nullptr;
@@ -368,7 +368,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -394,7 +394,7 @@ failure:
   }
 
   // string version = 4;
-  if (this->version().size() > 0) {
+  if (!this->version().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_version().data(), static_cast<int>(this->_internal_version().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -464,14 +464,14 @@ size_t Api::ByteSizeLong() const {
   }
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
   }
 
   // string version = 4;
-  if (this->version().size() > 0) {
+  if (!this->version().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_version());
@@ -524,10 +524,10 @@ void Api::MergeFrom(const Api& from) {
   methods_.MergeFrom(from.methods_);
   options_.MergeFrom(from.options_);
   mixins_.MergeFrom(from.mixins_);
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
-  if (from.version().size() > 0) {
+  if (!from.version().empty()) {
     _internal_set_version(from._internal_version());
   }
   if (from.has_source_context()) {
@@ -562,8 +562,16 @@ void Api::InternalSwap(Api* other) {
   methods_.InternalSwap(&other->methods_);
   options_.InternalSwap(&other->options_);
   mixins_.InternalSwap(&other->mixins_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  version_.Swap(&other->version_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &version_, GetArenaForAllocation(),
+      &other->version_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(Api, syntax_)
       + sizeof(Api::syntax_)
@@ -601,17 +609,17 @@ Method::Method(const Method& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   request_type_url_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_request_type_url().empty()) {
     request_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_request_type_url(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   response_type_url_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_response_type_url().empty()) {
     response_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_response_type_url(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ::memcpy(&request_streaming_, &from.request_streaming_,
     static_cast<size_t>(reinterpret_cast<char*>(&syntax_) -
@@ -636,7 +644,7 @@ Method::~Method() {
 }
 
 void Method::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   request_type_url_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   response_type_url_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -765,7 +773,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -775,7 +783,7 @@ failure:
   }
 
   // string request_type_url = 2;
-  if (this->request_type_url().size() > 0) {
+  if (!this->request_type_url().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_request_type_url().data(), static_cast<int>(this->_internal_request_type_url().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -791,7 +799,7 @@ failure:
   }
 
   // string response_type_url = 4;
-  if (this->response_type_url().size() > 0) {
+  if (!this->response_type_url().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_response_type_url().data(), static_cast<int>(this->_internal_response_type_url().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -845,21 +853,21 @@ size_t Method::ByteSizeLong() const {
   }
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
   }
 
   // string request_type_url = 2;
-  if (this->request_type_url().size() > 0) {
+  if (!this->request_type_url().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_request_type_url());
   }
 
   // string response_type_url = 4;
-  if (this->response_type_url().size() > 0) {
+  if (!this->response_type_url().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_response_type_url());
@@ -913,13 +921,13 @@ void Method::MergeFrom(const Method& from) {
   (void) cached_has_bits;
 
   options_.MergeFrom(from.options_);
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
-  if (from.request_type_url().size() > 0) {
+  if (!from.request_type_url().empty()) {
     _internal_set_request_type_url(from._internal_request_type_url());
   }
-  if (from.response_type_url().size() > 0) {
+  if (!from.response_type_url().empty()) {
     _internal_set_response_type_url(from._internal_response_type_url());
   }
   if (from.request_streaming() != 0) {
@@ -955,9 +963,21 @@ void Method::InternalSwap(Method* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   options_.InternalSwap(&other->options_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  request_type_url_.Swap(&other->request_type_url_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  response_type_url_.Swap(&other->response_type_url_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &request_type_url_, GetArenaForAllocation(),
+      &other->request_type_url_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &response_type_url_, GetArenaForAllocation(),
+      &other->response_type_url_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(Method, syntax_)
       + sizeof(Method::syntax_)
@@ -990,12 +1010,12 @@ Mixin::Mixin(const Mixin& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   root_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_root().empty()) {
     root_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_root(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   // @@protoc_insertion_point(copy_constructor:google.protobuf.Mixin)
 }
@@ -1012,7 +1032,7 @@ Mixin::~Mixin() {
 }
 
 void Mixin::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   root_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
@@ -1092,7 +1112,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1102,7 +1122,7 @@ failure:
   }
 
   // string root = 2;
-  if (this->root().size() > 0) {
+  if (!this->root().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_root().data(), static_cast<int>(this->_internal_root().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1128,14 +1148,14 @@ size_t Mixin::ByteSizeLong() const {
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
   }
 
   // string root = 2;
-  if (this->root().size() > 0) {
+  if (!this->root().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_root());
@@ -1172,10 +1192,10 @@ void Mixin::MergeFrom(const Mixin& from) {
   ::PROTOBUF_NAMESPACE_ID::uint32 cached_has_bits = 0;
   (void) cached_has_bits;
 
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
-  if (from.root().size() > 0) {
+  if (!from.root().empty()) {
     _internal_set_root(from._internal_root());
   }
 }
@@ -1201,8 +1221,16 @@ bool Mixin::IsInitialized() const {
 void Mixin::InternalSwap(Mixin* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  root_.Swap(&other->root_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &root_, GetArenaForAllocation(),
+      &other->root_, other->GetArenaForAllocation()
+  );
 }
 
 ::PROTOBUF_NAMESPACE_ID::Metadata Mixin::GetMetadata() const {

src/google/protobuf/api.pb.h

@@ -75,7 +75,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Api final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Api) */ {
  public:
   inline Api() : Api(nullptr) {}
@@ -93,8 +93,9 @@ class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
     return *this;
   }
   inline Api& operator=(Api&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -125,7 +126,7 @@ class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
   }
   inline void Swap(Api* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -133,14 +134,14 @@ class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Api* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Api* New() const final {
-    return CreateMaybeMessage<Api>(nullptr);
+    return new Api();
   }
 
   Api* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -250,11 +251,11 @@ class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -264,11 +265,11 @@ class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_version(ArgT0&& arg0, ArgT... args);
   std::string* mutable_version();
-  std::string* release_version();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_version();
   void set_allocated_version(std::string* version);
   private:
   const std::string& _internal_version() const;
-  void _internal_set_version(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_version(const std::string& value);
   std::string* _internal_mutable_version();
   public:
 
@@ -318,7 +319,7 @@ class PROTOBUF_EXPORT Api PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Method final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Method) */ {
  public:
   inline Method() : Method(nullptr) {}
@@ -336,8 +337,9 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
     return *this;
   }
   inline Method& operator=(Method&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -368,7 +370,7 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
   }
   inline void Swap(Method* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -376,14 +378,14 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Method* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Method* New() const final {
-    return CreateMaybeMessage<Method>(nullptr);
+    return new Method();
   }
 
   Method* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -457,11 +459,11 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -471,11 +473,11 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_request_type_url(ArgT0&& arg0, ArgT... args);
   std::string* mutable_request_type_url();
-  std::string* release_request_type_url();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_request_type_url();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_request_type_url(const std::string& value);
   std::string* _internal_mutable_request_type_url();
   public:
 
@@ -485,11 +487,11 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_response_type_url(ArgT0&& arg0, ArgT... args);
   std::string* mutable_response_type_url();
-  std::string* release_response_type_url();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_response_type_url();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_response_type_url(const std::string& value);
   std::string* _internal_mutable_response_type_url();
   public:
 
@@ -539,7 +541,7 @@ class PROTOBUF_EXPORT Method PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Mixin PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Mixin final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Mixin) */ {
  public:
   inline Mixin() : Mixin(nullptr) {}
@@ -557,8 +559,9 @@ class PROTOBUF_EXPORT Mixin PROTOBUF_FINAL :
     return *this;
   }
   inline Mixin& operator=(Mixin&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -589,7 +592,7 @@ class PROTOBUF_EXPORT Mixin PROTOBUF_FINAL :
   }
   inline void Swap(Mixin* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -597,14 +600,14 @@ class PROTOBUF_EXPORT Mixin PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Mixin* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Mixin* New() const final {
-    return CreateMaybeMessage<Mixin>(nullptr);
+    return new Mixin();
   }
 
   Mixin* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -655,11 +658,11 @@ class PROTOBUF_EXPORT Mixin PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -669,11 +672,11 @@ class PROTOBUF_EXPORT Mixin PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_root(ArgT0&& arg0, ArgT... args);
   std::string* mutable_root();
-  std::string* release_root();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_root();
   void set_allocated_root(std::string* root);
   private:
   const std::string& _internal_root() const;
-  void _internal_set_root(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_root(const std::string& value);
   std::string* _internal_mutable_root();
   public:
 
@@ -709,10 +712,10 @@ inline const std::string& Api::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Api::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Api::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Api.name)
 }
 inline std::string* Api::mutable_name() {
@@ -724,15 +727,15 @@ inline const std::string& Api::_internal_name() const {
 }
 inline void Api::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Api::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Api::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Api.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Api::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -741,7 +744,7 @@ inline void Api::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Api.name)
 }
 
@@ -829,10 +832,10 @@ inline const std::string& Api::version() const {
   return _internal_version();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Api::set_version(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Api::set_version(ArgT0&& arg0, ArgT... args) {
  
- version_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ version_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Api.version)
 }
 inline std::string* Api::mutable_version() {
@@ -844,15 +847,15 @@ inline const std::string& Api::_internal_version() const {
 }
 inline void Api::_internal_set_version(const std::string& value) {
   
-  version_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  version_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Api::_internal_mutable_version() {
   
-  return version_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return version_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Api::release_version() {
   // @@protoc_insertion_point(field_release:google.protobuf.Api.version)
-  return version_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return version_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Api::set_allocated_version(std::string* version) {
   if (version != nullptr) {
@@ -861,7 +864,7 @@ inline void Api::set_allocated_version(std::string* version) {
     
   }
   version_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), version,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Api.version)
 }
 
@@ -883,7 +886,7 @@ inline const PROTOBUF_NAMESPACE_ID::SourceContext& Api::source_context() const {
 }
 inline void Api::unsafe_arena_set_allocated_source_context(
     PROTOBUF_NAMESPACE_ID::SourceContext* source_context) {
-  if (GetArena() == nullptr) {
+  if (GetArenaForAllocation() == nullptr) {
     delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context_);
   }
   source_context_ = source_context;
@@ -898,7 +901,7 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Api::release_source_context() {
   
   PROTOBUF_NAMESPACE_ID::SourceContext* temp = source_context_;
   source_context_ = nullptr;
-  if (GetArena() != nullptr) {
+  if (GetArenaForAllocation() != nullptr) {
     temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
   }
   return temp;
@@ -913,7 +916,7 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Api::unsafe_arena_release_source_co
 inline PROTOBUF_NAMESPACE_ID::SourceContext* Api::_internal_mutable_source_context() {
   
   if (source_context_ == nullptr) {
-    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::SourceContext>(GetArena());
+    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::SourceContext>(GetArenaForAllocation());
     source_context_ = p;
   }
   return source_context_;
@@ -923,13 +926,15 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Api::mutable_source_context() {
   return _internal_mutable_source_context();
 }
 inline void Api::set_allocated_source_context(PROTOBUF_NAMESPACE_ID::SourceContext* source_context) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   if (message_arena == nullptr) {
     delete reinterpret_cast< ::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context_);
   }
   if (source_context) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context)->GetArena();
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<
+            ::PROTOBUF_NAMESPACE_ID::MessageLite>::GetOwningArena(
+                reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context));
     if (message_arena != submessage_arena) {
       source_context = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, source_context, submessage_arena);
@@ -1014,10 +1019,10 @@ inline const std::string& Method::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Method::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Method::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Method.name)
 }
 inline std::string* Method::mutable_name() {
@@ -1029,15 +1034,15 @@ inline const std::string& Method::_internal_name() const {
 }
 inline void Method::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Method::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Method::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Method.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Method::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -1046,7 +1051,7 @@ inline void Method::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Method.name)
 }
 
@@ -1059,10 +1064,10 @@ inline const std::string& Method::request_type_url() const {
   return _internal_request_type_url();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Method::set_request_type_url(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Method::set_request_type_url(ArgT0&& arg0, ArgT... args) {
  
- request_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ request_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Method.request_type_url)
 }
 inline std::string* Method::mutable_request_type_url() {
@@ -1074,15 +1079,15 @@ inline const std::string& Method::_internal_request_type_url() const {
 }
 inline void Method::_internal_set_request_type_url(const std::string& value) {
   
-  request_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  request_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Method::_internal_mutable_request_type_url() {
   
-  return request_type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return request_type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Method::release_request_type_url() {
   // @@protoc_insertion_point(field_release:google.protobuf.Method.request_type_url)
-  return request_type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return request_type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Method::set_allocated_request_type_url(std::string* request_type_url) {
   if (request_type_url != nullptr) {
@@ -1091,7 +1096,7 @@ inline void Method::set_allocated_request_type_url(std::string* request_type_url
     
   }
   request_type_url_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), request_type_url,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Method.request_type_url)
 }
 
@@ -1124,10 +1129,10 @@ inline const std::string& Method::response_type_url() const {
   return _internal_response_type_url();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Method::set_response_type_url(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Method::set_response_type_url(ArgT0&& arg0, ArgT... args) {
  
- response_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ response_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Method.response_type_url)
 }
 inline std::string* Method::mutable_response_type_url() {
@@ -1139,15 +1144,15 @@ inline const std::string& Method::_internal_response_type_url() const {
 }
 inline void Method::_internal_set_response_type_url(const std::string& value) {
   
-  response_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  response_type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Method::_internal_mutable_response_type_url() {
   
-  return response_type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return response_type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Method::release_response_type_url() {
   // @@protoc_insertion_point(field_release:google.protobuf.Method.response_type_url)
-  return response_type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return response_type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Method::set_allocated_response_type_url(std::string* response_type_url) {
   if (response_type_url != nullptr) {
@@ -1156,7 +1161,7 @@ inline void Method::set_allocated_response_type_url(std::string* response_type_u
     
   }
   response_type_url_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), response_type_url,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Method.response_type_url)
 }
 
@@ -1249,10 +1254,10 @@ inline const std::string& Mixin::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Mixin::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Mixin::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Mixin.name)
 }
 inline std::string* Mixin::mutable_name() {
@@ -1264,15 +1269,15 @@ inline const std::string& Mixin::_internal_name() const {
 }
 inline void Mixin::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Mixin::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Mixin::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Mixin.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Mixin::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -1281,7 +1286,7 @@ inline void Mixin::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Mixin.name)
 }
 
@@ -1294,10 +1299,10 @@ inline const std::string& Mixin::root() const {
   return _internal_root();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Mixin::set_root(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Mixin::set_root(ArgT0&& arg0, ArgT... args) {
  
- root_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ root_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Mixin.root)
 }
 inline std::string* Mixin::mutable_root() {
@@ -1309,15 +1314,15 @@ inline const std::string& Mixin::_internal_root() const {
 }
 inline void Mixin::_internal_set_root(const std::string& value) {
   
-  root_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  root_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Mixin::_internal_mutable_root() {
   
-  return root_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return root_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Mixin::release_root() {
   // @@protoc_insertion_point(field_release:google.protobuf.Mixin.root)
-  return root_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return root_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Mixin::set_allocated_root(std::string* root) {
   if (root != nullptr) {
@@ -1326,7 +1331,7 @@ inline void Mixin::set_allocated_root(std::string* root) {
     
   }
   root_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), root,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Mixin.root)
 }
 

src/google/protobuf/arena.h

@@ -93,8 +93,8 @@ class EpsCopyInputStream;  // defined in parse_context.h
 template <typename Type>
 class GenericTypeHandler;  // defined in repeated_field.h
 
-PROTOBUF_ALWAYS_INLINE
-inline void* AlignTo(void* ptr, size_t align) {
+inline PROTOBUF_ALWAYS_INLINE
+void* AlignTo(void* ptr, size_t align) {
   return reinterpret_cast<void*>(
       (reinterpret_cast<uintptr_t>(ptr) + align - 1) & (~align + 1));
 }
@@ -399,6 +399,16 @@ class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
 
   template <typename T>
   class InternalHelper {
+   public:
+    // Provides access to protected GetOwningArena to generated messages.
+    static Arena* GetOwningArena(const T* p) { return p->GetOwningArena(); }
+
+    // Provides access to protected GetArenaForAllocation to generated messages.
+    static Arena* GetArenaForAllocation(const T* p) {
+      return p->GetArenaForAllocation();
+    }
+
+   private:
     template <typename U>
     static char DestructorSkippable(const typename U::DestructorSkippable_*);
     template <typename U>
@@ -439,6 +449,10 @@ class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
       return new (ptr) T(std::forward<Args>(args)...);
     }
 
+    static T* New() {
+      return new T(nullptr);
+    }
+
     static Arena* GetArena(const T* p) { return p->GetArena(); }
 
     friend class Arena;
@@ -490,7 +504,9 @@ class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
         InternalHelper<T>::is_arena_constructable::value,
         "CreateMessage can only construct types that are ArenaConstructable");
     if (arena == NULL) {
-      return new T();
+      // Generated arena constructor T(Arena*) is protected. Call via
+      // InternalHelper.
+      return InternalHelper<T>::New();
     } else {
       return arena->DoCreateMessage<T>();
     }
@@ -678,6 +694,25 @@ class PROTOBUF_EXPORT PROTOBUF_ALIGNAS(8) Arena final {
     return nullptr;
   }
 
+  template <typename T>
+  PROTOBUF_ALWAYS_INLINE static Arena* GetOwningArena(const T* value) {
+    return GetOwningArenaInternal(
+        value, std::is_convertible<T*, MessageLite*>());
+  }
+
+  // Implementation for GetOwningArena(). All and only message objects have
+  // GetOwningArena() method.
+  template <typename T>
+  PROTOBUF_ALWAYS_INLINE static Arena* GetOwningArenaInternal(
+      const T* value, std::true_type) {
+    return InternalHelper<T>::GetOwningArena(value);
+  }
+  template <typename T>
+  PROTOBUF_ALWAYS_INLINE static Arena* GetOwningArenaInternal(
+      const T* value, std::false_type) {
+    return nullptr;
+  }
+
   // For friends of arena.
   void* AllocateAligned(size_t n, size_t align = 8) {
     if (align <= 8) {

src/google/protobuf/arenastring.h

@@ -223,11 +223,11 @@ struct PROTOBUF_EXPORT ArenaStringPtr {
   }
 
   // Basic accessors.
-  const std::string& Get() const PROTOBUF_NDEBUG_INLINE {
+  PROTOBUF_NDEBUG_INLINE const std::string& Get() const {
     // Unconditionally mask away the tag.
     return *tagged_ptr_.Get();
   }
-  const std::string* GetPointer() const PROTOBUF_NDEBUG_INLINE {
+  PROTOBUF_NDEBUG_INLINE const std::string* GetPointer() const {
     // Unconditionally mask away the tag.
     return tagged_ptr_.Get();
   }
@@ -241,10 +241,10 @@ struct PROTOBUF_EXPORT ArenaStringPtr {
   // Own()'d by any arena. If the field is not set, this returns NULL. The
   // caller retains ownership. Clears this field back to NULL state. Used to
   // implement release_<field>() methods on generated classes.
-  std::string* Release(const std::string* default_value,
-                       ::google::protobuf::Arena* arena);
-  std::string* ReleaseNonDefault(const std::string* default_value,
-                                 ::google::protobuf::Arena* arena);
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* Release(
+      const std::string* default_value, ::google::protobuf::Arena* arena);
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* ReleaseNonDefault(
+      const std::string* default_value, ::google::protobuf::Arena* arena);
 
   // Takes a std::string that is heap-allocated, and takes ownership. The
   // std::string's destructor is registered with the arena. Used to implement
@@ -255,8 +255,9 @@ struct PROTOBUF_EXPORT ArenaStringPtr {
   // Swaps internal pointers. Arena-safety semantics: this is guarded by the
   // logic in Swap()/UnsafeArenaSwap() at the message level, so this method is
   // 'unsafe' if called directly.
-  inline void Swap(ArenaStringPtr* other, const std::string* default_value,
-                   Arena* arena) PROTOBUF_NDEBUG_INLINE;
+  inline PROTOBUF_NDEBUG_INLINE static void InternalSwap(
+      const std::string* default_value, ArenaStringPtr* rhs, Arena* rhs_arena,
+      ArenaStringPtr* lhs, Arena* lhs_arena);
 
   // Frees storage (if not on an arena).
   void Destroy(const std::string* default_value, ::google::protobuf::Arena* arena);
@@ -340,36 +341,28 @@ inline void ArenaStringPtr::UnsafeSetDefault(const std::string* value) {
   tagged_ptr_.Set(const_cast<std::string*>(value));
 }
 
-inline void ArenaStringPtr::Swap(ArenaStringPtr* other,
-                                 const std::string* default_value,
-                                 Arena* arena) {
-#ifndef NDEBUG
-  // For debug builds, we swap the contents of the string, rather than the
-  // std::string instances themselves.  This invalidates previously taken const
-  // references that are (per our documentation) invalidated by calling Swap()
-  // on the message.
-  //
-  // If both strings are the default_value, swapping is uninteresting.
-  // Otherwise, we use ArenaStringPtr::Mutable() to access the std::string, to
-  // ensure that we do not try to mutate default_value itself.
-  if (IsDefault(default_value) && other->IsDefault(default_value)) {
-    return;
-  }
-
-  if (default_value == nullptr) {
-    // If we have non-empty default, then `default_value` is null and we can't
-    // call Mutable the same way. Just do the regular swap.
-    std::swap(tagged_ptr_, other->tagged_ptr_);
-  } else {
-    std::string* this_ptr = Mutable(EmptyDefault{}, arena);
-    std::string* other_ptr = other->Mutable(EmptyDefault{}, arena);
-
-    this_ptr->swap(*other_ptr);
-  }
-#else
+inline PROTOBUF_NDEBUG_INLINE void ArenaStringPtr::InternalSwap(  //
+    const std::string* default_value,                             //
+    ArenaStringPtr* rhs, Arena* rhs_arena,                        //
+    ArenaStringPtr* lhs, Arena* lhs_arena) {
   (void)default_value;
-  (void)arena;
-  std::swap(tagged_ptr_, other->tagged_ptr_);
+  std::swap(lhs_arena, rhs_arena);
+  std::swap(lhs->tagged_ptr_, rhs->tagged_ptr_);
+#if 0  // TODO(b/186650244): renable this
+#ifndef NDEBUG
+  auto force_realloc = [default_value](ArenaStringPtr* p, Arena* arena) {
+    if (p->IsDefault(default_value)) return;
+    std::string* old_value = p->tagged_ptr_.Get();
+    std::string* new_value =
+        p->IsDonatedString()
+            ? Arena::Create<std::string>(arena, *old_value)
+            : Arena::Create<std::string>(arena, std::move(*old_value));
+    if (arena == nullptr) delete old_value;
+    p->tagged_ptr_.Set(new_value);
+  };
+  force_realloc(lhs, lhs_arena);
+  force_realloc(rhs, rhs_arena);
+#endif
 #endif
 }
 

src/google/protobuf/arenastring_unittest.cc

@@ -54,121 +54,100 @@ namespace protobuf {
 
 using internal::ArenaStringPtr;
 
-static std::string WrapString(const char* value) { return value; }
-
 using EmptyDefault = ArenaStringPtr::EmptyDefault;
 
 const internal::LazyString nonempty_default{{{"default", 7}}, {nullptr}};
+const std::string* empty_default = &internal::GetEmptyString();
+
+class SingleArena : public testing::TestWithParam<bool> {
+ public:
+  std::unique_ptr<Arena> GetArena() {
+    if (this->GetParam()) return nullptr;
+    return std::unique_ptr<Arena>(new Arena());
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(ArenaString, SingleArena, testing::Bool());
 
-// Test ArenaStringPtr with arena == NULL.
-TEST(ArenaStringPtrTest, ArenaStringPtrOnHeap) {
+TEST_P(SingleArena, GetSet) {
+  auto arena = GetArena();
   ArenaStringPtr field;
-  const std::string* empty_default = &internal::GetEmptyString();
   field.UnsafeSetDefault(empty_default);
-  EXPECT_EQ(std::string(""), field.Get());
-  field.Set(empty_default, WrapString("Test short"), NULL);
-  EXPECT_EQ(std::string("Test short"), field.Get());
-  field.Set(empty_default, WrapString("Test long long long long value"), NULL);
-  EXPECT_EQ(std::string("Test long long long long value"), field.Get());
-  field.Set(empty_default, std::string(""), NULL);
-  field.Destroy(empty_default, NULL);
-
-  ArenaStringPtr field2;
-  field2.UnsafeSetDefault(empty_default);
-  std::string* mut = field2.Mutable(EmptyDefault{}, NULL);
-  EXPECT_EQ(mut, field2.Mutable(EmptyDefault{}, NULL));
-  EXPECT_EQ(mut, &field2.Get());
-  EXPECT_NE(empty_default, mut);
-  EXPECT_EQ(std::string(""), *mut);
-  *mut = "Test long long long long value";  // ensure string allocates storage
-  EXPECT_EQ(std::string("Test long long long long value"), field2.Get());
-  field2.Destroy(empty_default, NULL);
-
-  ArenaStringPtr field3;
-  field3.UnsafeSetDefault(nullptr);
-  mut = field3.Mutable(nonempty_default, NULL);
-  EXPECT_EQ(mut, field3.Mutable(nonempty_default, NULL));
-  EXPECT_EQ(mut, &field3.Get());
-  EXPECT_NE(nullptr, mut);
-  EXPECT_EQ(std::string("default"), *mut);
-  *mut = "Test long long long long value";  // ensure string allocates storage
-  EXPECT_EQ(std::string("Test long long long long value"), field3.Get());
-  field3.Destroy(nullptr, NULL);
+  EXPECT_EQ("", field.Get());
+  field.Set(empty_default, "Test short", arena.get());
+  EXPECT_EQ("Test short", field.Get());
+  field.Set(empty_default, "Test long long long long value", arena.get());
+  EXPECT_EQ("Test long long long long value", field.Get());
+  field.Set(empty_default, "", arena.get());
+  field.Destroy(empty_default, arena.get());
 }
 
-TEST(ArenaStringPtrTest, ArenaStringPtrOnArena) {
-  Arena arena;
+TEST_P(SingleArena, MutableAccessor) {
+  auto arena = GetArena();
   ArenaStringPtr field;
   const std::string* empty_default = &internal::GetEmptyString();
   field.UnsafeSetDefault(empty_default);
-  EXPECT_EQ(std::string(""), field.Get());
-  field.Set(empty_default, WrapString("Test short"), &arena);
-  EXPECT_EQ(std::string("Test short"), field.Get());
-  field.Set(empty_default, WrapString("Test long long long long value"),
-            &arena);
-  EXPECT_EQ(std::string("Test long long long long value"), field.Get());
-  field.Set(empty_default, std::string(""), &arena);
-  field.Destroy(empty_default, &arena);
-
-  ArenaStringPtr field2;
-  field2.UnsafeSetDefault(empty_default);
-  std::string* mut = field2.Mutable(EmptyDefault{}, &arena);
-  EXPECT_EQ(mut, field2.Mutable(EmptyDefault{}, &arena));
-  EXPECT_EQ(mut, &field2.Get());
+
+  std::string* mut = field.Mutable(EmptyDefault{}, arena.get());
+  EXPECT_EQ(mut, field.Mutable(EmptyDefault{}, arena.get()));
+  EXPECT_EQ(mut, &field.Get());
   EXPECT_NE(empty_default, mut);
-  EXPECT_EQ(std::string(""), *mut);
+  EXPECT_EQ("", *mut);
   *mut = "Test long long long long value";  // ensure string allocates storage
-  EXPECT_EQ(std::string("Test long long long long value"), field2.Get());
-  field2.Destroy(empty_default, &arena);
-
-  ArenaStringPtr field3;
-  field3.UnsafeSetDefault(nullptr);
-  mut = field3.Mutable(nonempty_default, &arena);
-  EXPECT_EQ(mut, field3.Mutable(nonempty_default, &arena));
-  EXPECT_EQ(mut, &field3.Get());
-  EXPECT_NE(nullptr, mut);
-  EXPECT_EQ(std::string("default"), *mut);
-  *mut = "Test long long long long value";  // ensure string allocates storage
-  EXPECT_EQ(std::string("Test long long long long value"), field3.Get());
-  field3.Destroy(nullptr, &arena);
+  EXPECT_EQ("Test long long long long value", field.Get());
+  field.Destroy(empty_default, arena.get());
 }
 
-TEST(ArenaStringPtrTest, ArenaStringPtrOnArenaNoSSO) {
-  Arena arena;
+TEST_P(SingleArena, NullDefault) {
+  auto arena = GetArena();
+
   ArenaStringPtr field;
-  const std::string* empty_default = &internal::GetEmptyString();
-  field.UnsafeSetDefault(empty_default);
-  EXPECT_EQ(std::string(""), field.Get());
-
-  // Avoid triggering the SSO optimization by setting the string to something
-  // larger than the internal buffer.
-  field.Set(empty_default, WrapString("Test long long long long value"),
-            &arena);
-  EXPECT_EQ(std::string("Test long long long long value"), field.Get());
-  field.Set(empty_default, std::string(""), &arena);
-  field.Destroy(empty_default, &arena);
-
-  ArenaStringPtr field2;
-  field2.UnsafeSetDefault(empty_default);
-  std::string* mut = field2.Mutable(EmptyDefault{}, &arena);
-  EXPECT_EQ(mut, field2.Mutable(EmptyDefault{}, &arena));
-  EXPECT_EQ(mut, &field2.Get());
-  EXPECT_NE(empty_default, mut);
-  EXPECT_EQ(std::string(""), *mut);
-  *mut = "Test long long long long value";  // ensure string allocates storage
-  EXPECT_EQ(std::string("Test long long long long value"), field2.Get());
-  field2.Destroy(empty_default, &arena);
-
-  ArenaStringPtr field3;
-  field3.UnsafeSetDefault(nullptr);
-  mut = field3.Mutable(nonempty_default, &arena);
-  EXPECT_EQ(mut, field3.Mutable(nonempty_default, &arena));
-  EXPECT_EQ(mut, &field3.Get());
+  field.UnsafeSetDefault(nullptr);
+  std::string* mut = field.Mutable(nonempty_default, arena.get());
+  EXPECT_EQ(mut, field.Mutable(nonempty_default, arena.get()));
+  EXPECT_EQ(mut, &field.Get());
   EXPECT_NE(nullptr, mut);
-  EXPECT_EQ(std::string("default"), *mut);
+  EXPECT_EQ("default", *mut);
   *mut = "Test long long long long value";  // ensure string allocates storage
-  EXPECT_EQ(std::string("Test long long long long value"), field3.Get());
-  field3.Destroy(nullptr, &arena);
+  EXPECT_EQ("Test long long long long value", field.Get());
+  field.Destroy(nullptr, arena.get());
+}
+
+class DualArena : public testing::TestWithParam<std::tuple<bool, bool>> {
+ public:
+  std::unique_ptr<Arena> GetLhsArena() {
+    if (std::get<0>(this->GetParam())) return nullptr;
+    return std::unique_ptr<Arena>(new Arena());
+  }
+  std::unique_ptr<Arena> GetRhsArena() {
+    if (std::get<1>(this->GetParam())) return nullptr;
+    return std::unique_ptr<Arena>(new Arena());
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(ArenaString, DualArena,
+                         testing::Combine(testing::Bool(), testing::Bool()));
+
+TEST_P(DualArena, Swap) {
+  auto lhs_arena = GetLhsArena();
+  ArenaStringPtr lhs;
+  lhs.UnsafeSetDefault(empty_default);
+  ArenaStringPtr rhs;
+  rhs.UnsafeSetDefault(empty_default);
+
+  {
+    auto rhs_arena = GetRhsArena();
+    lhs.Set(empty_default, "lhs value that has some heft", lhs_arena.get());
+    rhs.Set(empty_default, "rhs value that has some heft", rhs_arena.get());
+    ArenaStringPtr::InternalSwap(empty_default,          //
+                                 &lhs, lhs_arena.get(),  //
+                                 &rhs, rhs_arena.get());
+    EXPECT_EQ("rhs value that has some heft", lhs.Get());
+    EXPECT_EQ("lhs value that has some heft", rhs.Get());
+    lhs.Destroy(empty_default, rhs_arena.get());
+  }
+  EXPECT_EQ("lhs value that has some heft", rhs.Get());
+  rhs.Destroy(empty_default, lhs_arena.get());
 }
 
 

src/google/protobuf/compiler/cpp/cpp_generator.cc

@@ -108,6 +108,18 @@ bool CppGenerator::Generate(const FileDescriptor* file,
       file_options.table_driven_parsing = true;
     } else if (options[i].first == "table_driven_serialization") {
       file_options.table_driven_serialization = true;
+    } else if (options[i].first == "experimental_tail_call_table_mode") {
+      if (options[i].second == "never") {
+        file_options.tctable_mode = Options::kTCTableNever;
+      } else if (options[i].second == "guarded") {
+        file_options.tctable_mode = Options::kTCTableGuarded;
+      } else if (options[i].second == "always") {
+        file_options.tctable_mode = Options::kTCTableAlways;
+      } else {
+        *error = "Unknown value for experimental_tail_call_table_mode: " +
+                 options[i].second;
+        return false;
+      }
     } else {
       *error = "Unknown generator option: " + options[i].first;
       return false;

src/google/protobuf/compiler/cpp/cpp_helpers.cc

@@ -648,17 +648,17 @@ std::string Int32ToString(int number) {
   }
 }
 
-std::string Int64ToString(const std::string& macro_prefix, int64_t number) {
+static std::string Int64ToString(int64_t number) {
   if (number == std::numeric_limits<int64_t>::min()) {
     // This needs to be special-cased, see explanation here:
     // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52661
-    return StrCat(macro_prefix, "_LONGLONG(", number + 1, ") - 1");
+    return StrCat("int64_t{", number + 1, "} - 1");
   }
-  return StrCat(macro_prefix, "_LONGLONG(", number, ")");
+  return StrCat("int64_t{", number, "}");
 }
 
-std::string UInt64ToString(const std::string& macro_prefix, uint64_t number) {
-  return StrCat(macro_prefix, "_ULONGLONG(", number, ")");
+static std::string UInt64ToString(uint64_t number) {
+  return StrCat("uint64_t{", number, "u}");
 }
 
 std::string DefaultValue(const FieldDescriptor* field) {
@@ -672,9 +672,9 @@ std::string DefaultValue(const Options& options, const FieldDescriptor* field) {
     case FieldDescriptor::CPPTYPE_UINT32:
       return StrCat(field->default_value_uint32()) + "u";
     case FieldDescriptor::CPPTYPE_INT64:
-      return Int64ToString("PROTOBUF", field->default_value_int64());
+      return Int64ToString(field->default_value_int64());
     case FieldDescriptor::CPPTYPE_UINT64:
-      return UInt64ToString("PROTOBUF", field->default_value_uint64());
+      return UInt64ToString(field->default_value_uint64());
     case FieldDescriptor::CPPTYPE_DOUBLE: {
       double value = field->default_value_double();
       if (value == std::numeric_limits<double>::infinity()) {

src/google/protobuf/compiler/cpp/cpp_helpers.h

@@ -220,9 +220,6 @@ const char* DeclaredTypeMethodName(FieldDescriptor::Type type);
 // Return the code that evaluates to the number when compiled.
 std::string Int32ToString(int number);
 
-// Return the code that evaluates to the number when compiled.
-std::string Int64ToString(const Options& options, int64_t number);
-
 // Get code that evaluates to the field's default value.
 std::string DefaultValue(const Options& options, const FieldDescriptor* field);
 

src/google/protobuf/compiler/cpp/cpp_map_field.cc

@@ -303,6 +303,19 @@ void MapFieldGenerator::GenerateConstinitInitializer(
   }
 }
 
+bool MapFieldGenerator::GenerateArenaDestructorCode(
+    io::Printer* printer) const {
+  Formatter format(printer, variables_);
+  if (HasDescriptorMethods(descriptor_->file(), options_)) {
+    // _this is the object being destructed (we are inside a static method
+    // here).
+    format("_this->$name$_. ~MapField();\n");
+    return true;
+  } else {
+    return false;
+  }
+}
+
 }  // namespace cpp
 }  // namespace compiler
 }  // namespace protobuf

src/google/protobuf/compiler/cpp/cpp_map_field.h

@@ -58,6 +58,7 @@ class MapFieldGenerator : public FieldGenerator {
   void GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const;
   void GenerateByteSize(io::Printer* printer) const;
   void GenerateConstinitInitializer(io::Printer* printer) const;
+  bool GenerateArenaDestructorCode(io::Printer* printer) const override;
 
  private:
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MapFieldGenerator);

src/google/protobuf/compiler/cpp/cpp_message.cc

@@ -215,7 +215,7 @@ bool EmitFieldNonDefaultCondition(io::Printer* printer,
   // if non-zero (numeric) or non-empty (string).
   if (!field->is_repeated() && !field->containing_oneof()) {
     if (field->cpp_type() == FieldDescriptor::CPPTYPE_STRING) {
-      format("if ($prefix$$name$().size() > 0) {\n");
+      format("if (!$prefix$$name$().empty()) {\n");
     } else if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) {
       // Message fields still have has_$name$() methods.
       format("if ($prefix$has_$name$()) {\n");
@@ -571,6 +571,7 @@ MessageGenerator::MessageGenerator(
   variables_["classtype"] = QualifiedClassName(descriptor_, options);
   variables_["full_name"] = descriptor_->full_name();
   variables_["superclass"] = SuperClassName(descriptor_, options_);
+  SetUnknkownFieldsVariable(descriptor_, options_, &variables_);
 
   // Compute optimized field order to be used for layout and initialization
   // purposes.
@@ -610,6 +611,8 @@ MessageGenerator::MessageGenerator(
   }
 
   table_driven_ = TableDrivenParsingEnabled(descriptor_, options_);
+  parse_function_generator_.reset(new ParseFunctionGenerator(
+      descriptor_, max_has_bit_index_, options_, scc_analyzer_));
 }
 
 MessageGenerator::~MessageGenerator() = default;
@@ -986,9 +989,8 @@ void MessageGenerator::GenerateFieldAccessorDefinitions(io::Printer* printer) {
 
 void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
   Formatter format(printer, variables_);
-  format.Set("class_final", ShouldMarkClassAsFinal(descriptor_, options_)
-                                ? "PROTOBUF_FINAL"
-                                : "");
+  format.Set("class_final",
+             ShouldMarkClassAsFinal(descriptor_, options_) ? "final" : "");
 
   if (IsMapEntryMessage(descriptor_)) {
     std::map<std::string, std::string> vars;
@@ -1028,7 +1030,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
             " }\n",
             descriptor_->field(0)->full_name());
       } else {
-        GOOGLE_CHECK_EQ(utf8_check, Utf8CheckMode::kVerify);
+        GOOGLE_CHECK(utf8_check == Utf8CheckMode::kVerify);
         format(
             "  static bool ValidateKey(std::string* s) {\n"
             "#ifndef NDEBUG\n"
@@ -1057,7 +1059,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
             " }\n",
             descriptor_->field(1)->full_name());
       } else {
-        GOOGLE_CHECK_EQ(utf8_check, Utf8CheckMode::kVerify);
+        GOOGLE_CHECK(utf8_check == Utf8CheckMode::kVerify);
         format(
             "  static bool ValidateValue(std::string* s) {\n"
             "#ifndef NDEBUG\n"
@@ -1109,8 +1111,9 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
       "  return *this;\n"
       "}\n"
       "inline $classname$& operator=($classname$&& from) noexcept {\n"
-      "  if (GetArena() == from.GetArena()) {\n"
-      "    if (this != &from) InternalSwap(&from);\n"
+      "  if (this == &from) return *this;\n"
+      "  if (GetOwningArena() == from.GetOwningArena()) {\n"
+      "    InternalSwap(&from);\n"
       "  } else {\n"
       "    CopyFrom(from);\n"
       "  }\n"
@@ -1126,9 +1129,6 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
         "\n");
   }
 
-  std::map<std::string, std::string> vars;
-  SetUnknkownFieldsVariable(descriptor_, options_, &vars);
-  format.AddMap(vars);
   if (PublicUnknownFieldsAccessors(descriptor_)) {
     format(
         "inline const $unknown_fields_type$& unknown_fields() const {\n"
@@ -1274,7 +1274,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
       "}\n"
       "inline void Swap($classname$* other) {\n"
       "  if (other == this) return;\n"
-      "  if (GetArena() == other->GetArena()) {\n"
+      "  if (GetOwningArena() == other->GetOwningArena()) {\n"
       "    InternalSwap(other);\n"
       "  } else {\n"
       "    ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);\n"
@@ -1282,7 +1282,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
       "}\n"
       "void UnsafeArenaSwap($classname$* other) {\n"
       "  if (other == this) return;\n"
-      "  $DCHK$(GetArena() == other->GetArena());\n"
+      "  $DCHK$(GetOwningArena() == other->GetOwningArena());\n"
       "  InternalSwap(other);\n"
       "}\n");
 
@@ -1291,7 +1291,7 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
       "// implements Message ----------------------------------------------\n"
       "\n"
       "inline $classname$* New() const final {\n"
-      "  return CreateMaybeMessage<$classname$>(nullptr);\n"
+      "  return new $classname$();\n"
       "}\n"
       "\n"
       "$classname$* New(::$proto_ns$::Arena* arena) const final {\n"
@@ -1324,9 +1324,11 @@ void MessageGenerator::GenerateClassDefinition(io::Printer* printer) {
         "PROTOBUF_ATTRIBUTE_REINITIALIZES void Clear()$ clear_final$;\n"
         "bool IsInitialized() const final;\n"
         "\n"
-        "size_t ByteSizeLong() const final;\n"
-        "const char* _InternalParse(const char* ptr, "
-        "::$proto_ns$::internal::ParseContext* ctx) final;\n"
+        "size_t ByteSizeLong() const final;\n");
+
+    parse_function_generator_->GenerateMethodDecls(printer);
+
+    format(
         "$uint8$* _InternalSerialize(\n"
         "    $uint8$* target, ::$proto_ns$::io::EpsCopyOutputStream* stream) "
         "const final;\n");
@@ -1982,7 +1984,7 @@ void MessageGenerator::GenerateClassMethods(io::Printer* printer) {
     GenerateClear(printer);
     format("\n");
 
-    GenerateMergeFromCodedStream(printer);
+    parse_function_generator_->GenerateMethodImpls(printer);
     format("\n");
 
     GenerateSerializeWithCachedSizesToArray(printer);
@@ -2317,7 +2319,7 @@ void MessageGenerator::GenerateSharedDestructorCode(io::Printer* printer) {
 
   format("void $classname$::SharedDtor() {\n");
   format.Indent();
-  format("$DCHK$(GetArena() == nullptr);\n");
+  format("$DCHK$(GetArenaForAllocation() == nullptr);\n");
   // Write the destructors for each field except oneof members.
   // optimized_order_ does not contain oneof fields.
   for (auto field : optimized_order_) {
@@ -3240,24 +3242,6 @@ void MessageGenerator::GenerateCopyFrom(io::Printer* printer) {
   format("}\n");
 }
 
-void MessageGenerator::GenerateMergeFromCodedStream(io::Printer* printer) {
-  std::map<std::string, std::string> vars = variables_;
-  SetUnknkownFieldsVariable(descriptor_, options_, &vars);
-  Formatter format(printer, vars);
-  if (descriptor_->options().message_set_wire_format()) {
-    // Special-case MessageSet.
-    format(
-        "const char* $classname$::_InternalParse(const char* ptr,\n"
-        "                  ::$proto_ns$::internal::ParseContext* ctx) {\n"
-        "  return _extensions_.ParseMessageSet(ptr, \n"
-        "      internal_default_instance(), &_internal_metadata_, ctx);\n"
-        "}\n");
-    return;
-  }
-  GenerateParseFunction(descriptor_, max_has_bit_index_, options_,
-                        scc_analyzer_, printer);
-}
-
 void MessageGenerator::GenerateSerializeOneofFields(
     io::Printer* printer, const std::vector<const FieldDescriptor*>& fields) {
   Formatter format(printer, variables_);

src/google/protobuf/compiler/cpp/cpp_message.h

@@ -44,6 +44,7 @@
 #include <google/protobuf/compiler/cpp/cpp_helpers.h>
 #include <google/protobuf/compiler/cpp/cpp_message_layout_helper.h>
 #include <google/protobuf/compiler/cpp/cpp_options.h>
+#include <google/protobuf/compiler/cpp/cpp_parse_function_generator.h>
 
 namespace google {
 namespace protobuf {
@@ -133,7 +134,6 @@ class MessageGenerator {
   // Generate standard Message methods.
   void GenerateClear(io::Printer* printer);
   void GenerateOneofClear(io::Printer* printer);
-  void GenerateMergeFromCodedStream(io::Printer* printer);
   void GenerateSerializeWithCachedSizes(io::Printer* printer);
   void GenerateSerializeWithCachedSizesToArray(io::Printer* printer);
   void GenerateSerializeWithCachedSizesBody(io::Printer* printer);
@@ -204,6 +204,7 @@ class MessageGenerator {
   bool table_driven_;
 
   std::unique_ptr<MessageLayoutHelper> message_layout_helper_;
+  std::unique_ptr<ParseFunctionGenerator> parse_function_generator_;
 
   MessageSCCAnalyzer* scc_analyzer_;
 

src/google/protobuf/compiler/cpp/cpp_message_field.cc

@@ -109,7 +109,8 @@ void MessageFieldGenerator::GenerateAccessorDeclarations(
     format(
         "$deprecated_attr$const $type$& ${1$$name$$}$() const { "
         "__builtin_trap(); }\n"
-        "$deprecated_attr$$type$* ${1$$release_name$$}$() { "
+        "PROTOBUF_FUTURE_MUST_USE_RESULT $deprecated_attr$$type$* "
+        "${1$$release_name$$}$() { "
         "__builtin_trap(); }\n"
         "$deprecated_attr$$type$* ${1$mutable_$name$$}$() { "
         "__builtin_trap(); }\n"
@@ -173,7 +174,7 @@ void MessageFieldGenerator::GenerateInlineAccessorDefinitions(
       "$annotate_accessor$"
       // If we're not on an arena, free whatever we were holding before.
       // (If we are on arena, we can just forget the earlier pointer.)
-      "  if (GetArena() == nullptr) {\n"
+      "  if (GetArenaForAllocation() == nullptr) {\n"
       "    delete reinterpret_cast<::$proto_ns$::MessageLite*>($name$_);\n"
       "  }\n");
   if (implicit_weak_field_) {
@@ -198,7 +199,7 @@ void MessageFieldGenerator::GenerateInlineAccessorDefinitions(
       "  $clear_hasbit$\n"
       "  $type$* temp = $casted_member$;\n"
       "  $name$_ = nullptr;\n"
-      "  if (GetArena() != nullptr) {\n"
+      "  if (GetArenaForAllocation() != nullptr) {\n"
       "    temp = ::$proto_ns$::internal::DuplicateIfNonNull(temp);\n"
       "  }\n"
       "  return temp;\n"
@@ -218,7 +219,7 @@ void MessageFieldGenerator::GenerateInlineAccessorDefinitions(
       "$type_reference_function$"
       "  $set_hasbit$\n"
       "  if ($name$_ == nullptr) {\n"
-      "    auto* p = CreateMaybeMessage<$type$>(GetArena());\n");
+      "    auto* p = CreateMaybeMessage<$type$>(GetArenaForAllocation());\n");
   if (implicit_weak_field_) {
     format("    $name$_ = reinterpret_cast<::$proto_ns$::MessageLite*>(p);\n");
   } else {
@@ -239,7 +240,7 @@ void MessageFieldGenerator::GenerateInlineAccessorDefinitions(
   format(
       "inline void $classname$::set_allocated_$name$($type$* $name$) {\n"
       "$annotate_accessor$"
-      "  ::$proto_ns$::Arena* message_arena = GetArena();\n");
+      "  ::$proto_ns$::Arena* message_arena = GetArenaForAllocation();\n");
   format("  if (message_arena == nullptr) {\n");
   if (IsCrossFileMessage(descriptor_)) {
     format(
@@ -255,12 +256,15 @@ void MessageFieldGenerator::GenerateInlineAccessorDefinitions(
     // isn't defined in this file.
     format(
         "    ::$proto_ns$::Arena* submessage_arena =\n"
-        "      "
-        "reinterpret_cast<::$proto_ns$::MessageLite*>($name$)->GetArena();\n");
+        "        ::$proto_ns$::Arena::InternalHelper<\n"
+        "            ::$proto_ns$::MessageLite>::GetOwningArena(\n"
+        "                reinterpret_cast<::$proto_ns$::MessageLite*>("
+        "$name$));\n");
   } else {
     format(
         "    ::$proto_ns$::Arena* submessage_arena =\n"
-        "      ::$proto_ns$::Arena::GetArena($name$);\n");
+        "        ::$proto_ns$::Arena::InternalHelper<$type$>::GetOwningArena("
+        "$name$);\n");
   }
   format(
       "    if (message_arena != submessage_arena) {\n"
@@ -329,11 +333,12 @@ void MessageFieldGenerator::GenerateInternalAccessorDefinitions(
         "    if ($type_default_instance_ptr$ == nullptr) {\n"
         "      msg->$name$_ = ::$proto_ns$::Arena::CreateMessage<\n"
         "          ::$proto_ns$::internal::ImplicitWeakMessage>(\n"
-        "              msg->GetArena());\n"
+        "              msg->GetArenaForAllocation());\n"
         "    } else {\n"
-        "      msg->$name$_ = reinterpret_cast<const "
-        "::$proto_ns$::MessageLite*>(\n"
-        "          $type_default_instance_ptr$)->New(msg->GetArena());\n"
+        "      msg->$name$_ = \n"
+        "          reinterpret_cast<const ::$proto_ns$::MessageLite*>(\n"
+        "              $type_default_instance_ptr$)->New(\n"
+        "                  msg->GetArenaForAllocation());\n"
         "    }\n"
         "  }\n"
         "  return msg->$name$_;\n"
@@ -358,7 +363,7 @@ void MessageFieldGenerator::GenerateClearingCode(io::Printer* printer) const {
     // If we don't have has-bits, message presence is indicated only by ptr !=
     // NULL. Thus on clear, we need to delete the object.
     format(
-        "if (GetArena() == nullptr && $name$_ != nullptr) {\n"
+        "if (GetArenaForAllocation() == nullptr && $name$_ != nullptr) {\n"
         "  delete $name$_;\n"
         "}\n"
         "$name$_ = nullptr;\n");
@@ -376,7 +381,7 @@ void MessageFieldGenerator::GenerateMessageClearingCode(
     // If we don't have has-bits, message presence is indicated only by ptr !=
     // NULL. Thus on clear, we need to delete the object.
     format(
-        "if (GetArena() == nullptr && $name$_ != nullptr) {\n"
+        "if (GetArenaForAllocation() == nullptr && $name$_ != nullptr) {\n"
         "  delete $name$_;\n"
         "}\n"
         "$name$_ = nullptr;\n");
@@ -490,7 +495,7 @@ void MessageOneofFieldGenerator::GenerateNonInlineAccessorDefinitions(
   format(
       "void $classname$::set_allocated_$name$($type$* $name$) {\n"
       "$annotate_accessor$"
-      "  ::$proto_ns$::Arena* message_arena = GetArena();\n"
+      "  ::$proto_ns$::Arena* message_arena = GetArenaForAllocation();\n"
       "  clear_$oneof_name$();\n"
       "  if ($name$) {\n");
   if (descriptor_->file() != descriptor_->message_type()->file()) {
@@ -498,12 +503,15 @@ void MessageOneofFieldGenerator::GenerateNonInlineAccessorDefinitions(
     // isn't defined in this file.
     format(
         "    ::$proto_ns$::Arena* submessage_arena =\n"
-        "      "
-        "reinterpret_cast<::$proto_ns$::MessageLite*>($name$)->GetArena();\n");
+        "        ::$proto_ns$::Arena::InternalHelper<\n"
+        "            ::$proto_ns$::MessageLite>::GetOwningArena(\n"
+        "                reinterpret_cast<::$proto_ns$::MessageLite*>("
+        "$name$));\n");
   } else {
     format(
         "    ::$proto_ns$::Arena* submessage_arena =\n"
-        "      ::$proto_ns$::Arena::GetArena($name$);\n");
+        "      ::$proto_ns$::Arena::InternalHelper<"
+        "$type$>::GetOwningArena($name$);\n");
   }
   format(
       "    if (message_arena != submessage_arena) {\n"
@@ -527,7 +535,7 @@ void MessageOneofFieldGenerator::GenerateInlineAccessorDefinitions(
       "  if (_internal_has_$name$()) {\n"
       "    clear_has_$oneof_name$();\n"
       "      $type$* temp = $field_member$;\n"
-      "    if (GetArena() != nullptr) {\n"
+      "    if (GetArenaForAllocation() != nullptr) {\n"
       "      temp = ::$proto_ns$::internal::DuplicateIfNonNull(temp);\n"
       "    }\n"
       "    $field_member$ = nullptr;\n"
@@ -579,7 +587,8 @@ void MessageOneofFieldGenerator::GenerateInlineAccessorDefinitions(
       "  if (!_internal_has_$name$()) {\n"
       "    clear_$oneof_name$();\n"
       "    set_has_$name$();\n"
-      "    $field_member$ = CreateMaybeMessage< $type$ >(GetArena());\n"
+      "    $field_member$ = CreateMaybeMessage< $type$ "
+      ">(GetArenaForAllocation());\n"
       "  }\n"
       "  return $field_member$;\n"
       "}\n"
@@ -596,7 +605,7 @@ void MessageOneofFieldGenerator::GenerateClearingCode(
 
   Formatter format(printer, variables_);
   format(
-      "if (GetArena() == nullptr) {\n"
+      "if (GetArenaForAllocation() == nullptr) {\n"
       "  delete $field_member$;\n"
       "}\n");
 }

src/google/protobuf/compiler/cpp/cpp_options.h

@@ -69,6 +69,11 @@ struct Options {
   std::string annotation_pragma_name;
   std::string annotation_guard_name;
   const AccessInfoMap* access_info_map = nullptr;
+  enum {
+    kTCTableNever,
+    kTCTableGuarded,
+    kTCTableAlways
+  } tctable_mode = kTCTableNever;
 };
 
 }  // namespace cpp

src/google/protobuf/compiler/cpp/cpp_parse_function_generator.h

@@ -31,20 +31,69 @@
 #ifndef GOOGLE_PROTOBUF_COMPILER_CPP_PARSE_FUNCTION_GENERATOR_H__
 #define GOOGLE_PROTOBUF_COMPILER_CPP_PARSE_FUNCTION_GENERATOR_H__
 
+#include <map>
+#include <string>
+#include <vector>
+
 #include <google/protobuf/compiler/cpp/cpp_helpers.h>
 #include <google/protobuf/compiler/cpp/cpp_options.h>
 #include <google/protobuf/io/printer.h>
 #include <google/protobuf/descriptor.h>
+#include <google/protobuf/wire_format_lite.h>
 
 namespace google {
 namespace protobuf {
 namespace compiler {
 namespace cpp {
 
-void GenerateParseFunction(const Descriptor* descriptor, int num_hasbits,
-                           const Options& options,
-                           MessageSCCAnalyzer* scc_analyzer,
-                           io::Printer* printer);
+// ParseFunctionGenerator generates the _InternalParse function for a message
+// (and any associated supporting members).
+class ParseFunctionGenerator {
+ public:
+  ParseFunctionGenerator(const Descriptor* descriptor, int num_hasbits,
+                         const Options& options,
+                         MessageSCCAnalyzer* scc_analyzer);
+
+  // Emits class-level method declarations to `printer`:
+  void GenerateMethodDecls(io::Printer* printer);
+
+  // Emits out-of-class method implementation definitions to `printer`:
+  void GenerateMethodImpls(io::Printer* printer);
+
+ private:
+  // Returns the proto runtime internal namespace.
+  std::string pi_ns();
+
+  // Generates a looping `_InternalParse` function.
+  void GenerateLoopingParseFunction(Formatter& format);
+
+  // Generates parsing code for an `ArenaString` field.
+  void GenerateArenaString(Formatter& format, const FieldDescriptor* field);
+
+  // Generates parsing code for a string-typed field.
+  void GenerateStrings(Formatter& format, const FieldDescriptor* field,
+                       bool check_utf8);
+
+  // Generates parsing code for a length-delimited field (strings, messages,
+  // etc.).
+  void GenerateLengthDelim(Formatter& format, const FieldDescriptor* field);
+
+  // Generates the parsing code for a known field.
+  void GenerateFieldBody(Formatter& format,
+                         google::protobuf::internal::WireFormatLite::WireType wiretype,
+                         const FieldDescriptor* field);
+
+  // Generates code to parse the next field from the input stream.
+  void GenerateParseIterationBody(
+      Formatter& format, const Descriptor* descriptor,
+      const std::vector<const FieldDescriptor*>& ordered_fields);
+
+  const Descriptor* descriptor_;
+  MessageSCCAnalyzer* scc_analyzer_;
+  const Options& options_;
+  std::map<std::string, std::string> variables_;
+  int num_hasbits_;
+};
 
 }  // namespace cpp
 }  // namespace compiler

src/google/protobuf/compiler/cpp/cpp_string_field.cc

@@ -162,14 +162,16 @@ void StringFieldGenerator::GenerateAccessorDeclarations(
       descriptor_);
   format(
       "$deprecated_attr$std::string* ${1$mutable_$name$$}$();\n"
-      "$deprecated_attr$std::string* ${1$$release_name$$}$();\n"
+      "PROTOBUF_FUTURE_MUST_USE_RESULT $deprecated_attr$std::string* "
+      "${1$$release_name$$}$();\n"
       "$deprecated_attr$void ${1$set_allocated_$name$$}$(std::string* "
       "$name$);\n",
       descriptor_);
   format(
       "private:\n"
       "const std::string& _internal_$name$() const;\n"
-      "void _internal_set_$name$(const std::string& value);\n"
+      "inline PROTOBUF_ALWAYS_INLINE void "
+      "_internal_set_$name$(const std::string& value);\n"
       "std::string* _internal_mutable_$name$();\n"
       "public:\n");
 
@@ -196,12 +198,12 @@ void StringFieldGenerator::GenerateInlineAccessorDefinitions(
       "  return _internal_$name$();\n"
       "}\n"
       "template <typename ArgT0, typename... ArgT>\n"
-      "PROTOBUF_ALWAYS_INLINE\n"
-      "inline void $classname$::set_$name$(ArgT0&& arg0, ArgT... args) {\n"
+      "inline PROTOBUF_ALWAYS_INLINE\n"
+      "void $classname$::set_$name$(ArgT0&& arg0, ArgT... args) {\n"
       "$annotate_accessor$"
       " $set_hasbit$\n"
       " $name$_.$setter$($default_value_tag$, static_cast<ArgT0 &&>(arg0),"
-      " args..., GetArena());\n"
+      " args..., GetArenaForAllocation());\n"
       "  // @@protoc_insertion_point(field_set:$full_name$)\n"
       "}\n"
       "inline std::string* $classname$::mutable_$name$() {\n"
@@ -215,12 +217,13 @@ void StringFieldGenerator::GenerateInlineAccessorDefinitions(
       "inline void $classname$::_internal_set_$name$(const std::string& "
       "value) {\n"
       "  $set_hasbit$\n"
-      "  $name$_.Set($default_value_tag$, value, GetArena());\n"
+      "  $name$_.Set($default_value_tag$, value, GetArenaForAllocation());\n"
       "}\n");
   format(
       "inline std::string* $classname$::_internal_mutable_$name$() {\n"
       "  $set_hasbit$\n"
-      "  return $name$_.Mutable($default_variable_or_tag$, GetArena());\n"
+      "  return $name$_.Mutable($default_variable_or_tag$, "
+      "GetArenaForAllocation());\n"
       "}\n"
       "inline std::string* $classname$::$release_name$() {\n"
       "$annotate_accessor$"
@@ -232,9 +235,11 @@ void StringFieldGenerator::GenerateInlineAccessorDefinitions(
         "    return nullptr;\n"
         "  }\n"
         "  $clear_hasbit$\n"
-        "  return $name$_.ReleaseNonDefault($init_value$, GetArena());\n");
+        "  return $name$_.ReleaseNonDefault($init_value$, "
+        "GetArenaForAllocation());\n");
   } else {
-    format("  return $name$_.Release($init_value$, GetArena());\n");
+    format(
+        "  return $name$_.Release($init_value$, GetArenaForAllocation());\n");
   }
 
   format(
@@ -247,7 +252,7 @@ void StringFieldGenerator::GenerateInlineAccessorDefinitions(
       "    $clear_hasbit$\n"
       "  }\n"
       "  $name$_.SetAllocated($init_value$, $name$,\n"
-      "      GetArena());\n"
+      "      GetArenaForAllocation());\n"
       "  // @@protoc_insertion_point(field_set_allocated:$full_name$)\n"
       "}\n");
 }
@@ -268,7 +273,8 @@ void StringFieldGenerator::GenerateClearingCode(io::Printer* printer) const {
   if (descriptor_->default_value_string().empty()) {
     format("$name$_.ClearToEmpty();\n");
   } else {
-    format("$name$_.ClearToDefault($lazy_variable$, GetArena());\n");
+    format(
+        "$name$_.ClearToDefault($lazy_variable$, GetArenaForAllocation());\n");
   }
 }
 
@@ -294,7 +300,8 @@ void StringFieldGenerator::GenerateMessageClearingCode(
   } else {
     // Clear to a non-empty default is more involved, as we try to use the
     // Arena if one is present and may need to reallocate the string.
-    format("$name$_.ClearToDefault($lazy_variable$, GetArena());\n ");
+    format(
+        "$name$_.ClearToDefault($lazy_variable$, GetArenaForAllocation());\n ");
   }
 }
 
@@ -306,7 +313,12 @@ void StringFieldGenerator::GenerateMergingCode(io::Printer* printer) const {
 
 void StringFieldGenerator::GenerateSwappingCode(io::Printer* printer) const {
   Formatter format(printer, variables_);
-  format("$name$_.Swap(&other->$name$_, $init_value$, GetArena());\n");
+  format(
+      "::$proto_ns$::internal::ArenaStringPtr::InternalSwap(\n"
+      "    $init_value$,\n"
+      "    &$name$_, GetArenaForAllocation(),\n"
+      "    &other->$name$_, other->GetArenaForAllocation()\n"
+      ");\n");
 }
 
 void StringFieldGenerator::GenerateConstructorCode(io::Printer* printer) const {
@@ -330,7 +342,7 @@ void StringFieldGenerator::GenerateCopyConstructorCode(
   // TODO(gpike): improve this
   format(
       "$name$_.Set($default_value_tag$, from._internal_$name$(), \n"
-      "  GetArena());\n");
+      "  GetArenaForAllocation());\n");
 
   format.Outdent();
   format("}\n");
@@ -405,7 +417,7 @@ void StringOneofFieldGenerator::GenerateInlineAccessorDefinitions(
       "    $field_member$.UnsafeSetDefault($init_value$);\n"
       "  }\n"
       "  $field_member$.$setter$($default_value_tag$,"
-      " static_cast<ArgT0 &&>(arg0), args..., GetArena());\n"
+      " static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());\n"
       "  // @@protoc_insertion_point(field_set:$full_name$)\n"
       "}\n"
       "inline std::string* $classname$::mutable_$name$() {\n"
@@ -426,7 +438,8 @@ void StringOneofFieldGenerator::GenerateInlineAccessorDefinitions(
       "    set_has_$name$();\n"
       "    $field_member$.UnsafeSetDefault($init_value$);\n"
       "  }\n"
-      "  $field_member$.Set($default_value_tag$, value, GetArena());\n"
+      "  $field_member$.Set($default_value_tag$, value, "
+      "GetArenaForAllocation());\n"
       "}\n");
   format(
       "inline std::string* $classname$::_internal_mutable_$name$() {\n"
@@ -436,14 +449,15 @@ void StringOneofFieldGenerator::GenerateInlineAccessorDefinitions(
       "    $field_member$.UnsafeSetDefault($init_value$);\n"
       "  }\n"
       "  return $field_member$.Mutable(\n"
-      "      $default_variable_or_tag$, GetArena());\n"
+      "      $default_variable_or_tag$, GetArenaForAllocation());\n"
       "}\n"
       "inline std::string* $classname$::$release_name$() {\n"
       "$annotate_accessor$"
       "  // @@protoc_insertion_point(field_release:$full_name$)\n"
       "  if (_internal_has_$name$()) {\n"
       "    clear_has_$oneof_name$();\n"
-      "    return $field_member$.ReleaseNonDefault($init_value$, GetArena());\n"
+      "    return $field_member$.ReleaseNonDefault($init_value$, "
+      "GetArenaForAllocation());\n"
       "  } else {\n"
       "    return nullptr;\n"
       "  }\n"
@@ -456,7 +470,7 @@ void StringOneofFieldGenerator::GenerateInlineAccessorDefinitions(
       "  if ($name$ != nullptr) {\n"
       "    set_has_$name$();\n"
       "    $field_member$.UnsafeSetDefault($name$);\n"
-      "    ::$proto_ns$::Arena* arena = GetArena();\n"
+      "    ::$proto_ns$::Arena* arena = GetArenaForAllocation();\n"
       "    if (arena != nullptr) {\n"
       "      arena->Own($name$);\n"
       "    }\n"
@@ -468,7 +482,9 @@ void StringOneofFieldGenerator::GenerateInlineAccessorDefinitions(
 void StringOneofFieldGenerator::GenerateClearingCode(
     io::Printer* printer) const {
   Formatter format(printer, variables_);
-  format("$field_member$.Destroy($default_value_tag$, GetArena());\n");
+  format(
+      "$field_member$.Destroy($default_value_tag$, "
+      "GetArenaForAllocation());\n");
 }
 
 void StringOneofFieldGenerator::GenerateMessageClearingCode(

src/google/protobuf/compiler/cpp/cpp_unittest.inc

@@ -205,9 +205,6 @@ TEST(GENERATED_MESSAGE_TEST_NAME, Trigraph) {
 TEST(GENERATED_MESSAGE_TEST_NAME, ExtremeSmallIntegerDefault) {
   const UNITTEST::TestExtremeDefaultValues& extreme_default =
       UNITTEST::TestExtremeDefaultValues::default_instance();
-  EXPECT_EQ(~0x7fffffff, std::numeric_limits<int32_t>::min());
-  EXPECT_EQ(PROTOBUF_LONGLONG(~0x7fffffffffffffff),
-            std::numeric_limits<int64_t>::min());
   EXPECT_EQ(std::numeric_limits<int32_t>::min(),
             extreme_default.really_small_int32());
   EXPECT_EQ(std::numeric_limits<int64_t>::min(),

src/google/protobuf/compiler/java/java_message.cc

@@ -211,9 +211,14 @@ void ImmutableMessageGenerator::GenerateFieldAccessorTable(
       "  com.google.protobuf.GeneratedMessage$ver$.FieldAccessorTable\n"
       "    internal_$identifier$_fieldAccessorTable;\n");
 
+  // The following bytecode_estimate calculation logic must stay in sync with
+  // the similar logic in the GenerateFieldAccessorTableInitializer method below
+  // to make sure that the generated static final fields are initialized  in the
+  // static initialization block directly.
+  //
   // 6 bytes per field and oneof
   *bytecode_estimate +=
-      10 + 6 * descriptor_->field_count() + 6 * oneofs_.size();
+      10 + 6 * descriptor_->field_count() + 6 * descriptor_->oneof_decl_count();
 }
 
 int ImmutableMessageGenerator::GenerateFieldAccessorTableInitializer(
@@ -226,6 +231,10 @@ int ImmutableMessageGenerator::GenerateFieldAccessorTableInitializer(
       "    new java.lang.String[] { ",
       "identifier", UniqueFileScopeIdentifier(descriptor_), "ver",
       GeneratedCodeVersionSuffix());
+  // All the bytecode_estimate calculation logic in this method must stay in
+  // sync with the similar logic in the GenerateFieldAccessorTable method
+  // above. See the corresponding comment in GenerateFieldAccessorTable for
+  // details.
   for (int i = 0; i < descriptor_->field_count(); i++) {
     const FieldDescriptor* field = descriptor_->field(i);
     const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);

src/google/protobuf/compiler/parser.cc

@@ -1782,12 +1782,12 @@ bool Parser::ParseReserved(EnumDescriptorProto* message,
   DO(Consume("reserved"));
   if (LookingAtType(io::Tokenizer::TYPE_STRING)) {
     LocationRecorder location(message_location,
-                              DescriptorProto::kReservedNameFieldNumber);
+                              EnumDescriptorProto::kReservedNameFieldNumber);
     location.StartAt(start_token);
     return ParseReservedNames(message, location);
   } else {
     LocationRecorder location(message_location,
-                              DescriptorProto::kReservedRangeFieldNumber);
+                              EnumDescriptorProto::kReservedRangeFieldNumber);
     location.StartAt(start_token);
     return ParseReservedNumbers(message, location);
   }

src/google/protobuf/compiler/parser_unittest.cc

@@ -3139,6 +3139,43 @@ TEST_F(SourceInfoTest, EnumValues) {
   EXPECT_TRUE(HasSpan(file_.enum_type(0), "name"));
 }
 
+TEST_F(SourceInfoTest, EnumReservedRange) {
+  EXPECT_TRUE(
+      Parse("enum TestEnum {\n"
+            "  $a$reserved $b$1$c$ to $d$10$e$;$f$\n"
+            "}"));
+
+  const EnumDescriptorProto::EnumReservedRange& bar =
+      file_.enum_type(0).reserved_range(0);
+
+  EXPECT_TRUE(HasSpan('a', 'f', file_.enum_type(0), "reserved_range"));
+  EXPECT_TRUE(HasSpan('b', 'e', bar));
+  EXPECT_TRUE(HasSpan('b', 'c', bar, "start"));
+  EXPECT_TRUE(HasSpan('d', 'e', bar, "end"));
+
+  // Ignore these.
+  EXPECT_TRUE(HasSpan(file_));
+  EXPECT_TRUE(HasSpan(file_.enum_type(0)));
+  EXPECT_TRUE(HasSpan(file_.enum_type(0), "name"));
+}
+
+TEST_F(SourceInfoTest, EnumReservedName) {
+  EXPECT_TRUE(
+      Parse("enum TestEnum {\n"
+            "  $a$reserved $b$'foo'$c$;$d$\n"
+            "}"));
+
+  const EnumDescriptorProto& bar = file_.enum_type(0);
+
+  EXPECT_TRUE(HasSpan('a', 'd', bar, "reserved_name"));
+  EXPECT_TRUE(HasSpan('b', 'c', bar, "reserved_name", 0));
+
+  // Ignore these.
+  EXPECT_TRUE(HasSpan(file_));
+  EXPECT_TRUE(HasSpan(file_.enum_type(0)));
+  EXPECT_TRUE(HasSpan(file_.enum_type(0), "name"));
+}
+
 TEST_F(SourceInfoTest, NestedEnums) {
   EXPECT_TRUE(
       Parse("message Foo {\n"

src/google/protobuf/compiler/plugin.pb.cc

@@ -67,7 +67,7 @@ constexpr CodeGeneratorResponse::CodeGeneratorResponse(
   ::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized)
   : file_()
   , error_(&::PROTOBUF_NAMESPACE_ID::internal::fixed_address_empty_string)
-  , supported_features_(PROTOBUF_ULONGLONG(0)){}
+  , supported_features_(uint64_t{0u}){}
 struct CodeGeneratorResponseDefaultTypeInternal {
   constexpr CodeGeneratorResponseDefaultTypeInternal()
     : _instance(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized{}) {}
@@ -243,7 +243,7 @@ Version::Version(const Version& from)
   suffix_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_suffix()) {
     suffix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_suffix(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ::memcpy(&major_, &from.major_,
     static_cast<size_t>(reinterpret_cast<char*>(&patch_) -
@@ -266,7 +266,7 @@ Version::~Version() {
 }
 
 void Version::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   suffix_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -518,7 +518,11 @@ void Version::InternalSwap(Version* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  suffix_.Swap(&other->suffix_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &suffix_, GetArenaForAllocation(),
+      &other->suffix_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(Version, patch_)
       + sizeof(Version::patch_)
@@ -571,7 +575,7 @@ CodeGeneratorRequest::CodeGeneratorRequest(const CodeGeneratorRequest& from)
   parameter_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_parameter()) {
     parameter_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_parameter(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_compiler_version()) {
     compiler_version_ = new PROTOBUF_NAMESPACE_ID::compiler::Version(*from.compiler_version_);
@@ -593,7 +597,7 @@ CodeGeneratorRequest::~CodeGeneratorRequest() {
 }
 
 void CodeGeneratorRequest::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   parameter_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete compiler_version_;
 }
@@ -867,7 +871,11 @@ void CodeGeneratorRequest::InternalSwap(CodeGeneratorRequest* other) {
   swap(_has_bits_[0], other->_has_bits_[0]);
   file_to_generate_.InternalSwap(&other->file_to_generate_);
   proto_file_.InternalSwap(&other->proto_file_);
-  parameter_.Swap(&other->parameter_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &parameter_, GetArenaForAllocation(),
+      &other->parameter_, other->GetArenaForAllocation()
+  );
   swap(compiler_version_, other->compiler_version_);
 }
 
@@ -918,17 +926,17 @@ CodeGeneratorResponse_File::CodeGeneratorResponse_File(const CodeGeneratorRespon
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   insertion_point_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_insertion_point()) {
     insertion_point_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_insertion_point(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   content_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_content()) {
     content_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_content(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_generated_code_info()) {
     generated_code_info_ = new PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo(*from.generated_code_info_);
@@ -952,7 +960,7 @@ CodeGeneratorResponse_File::~CodeGeneratorResponse_File() {
 }
 
 void CodeGeneratorResponse_File::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   insertion_point_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   content_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -1228,9 +1236,21 @@ void CodeGeneratorResponse_File::InternalSwap(CodeGeneratorResponse_File* other)
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  insertion_point_.Swap(&other->insertion_point_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  content_.Swap(&other->content_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &insertion_point_, GetArenaForAllocation(),
+      &other->insertion_point_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &content_, GetArenaForAllocation(),
+      &other->content_, other->GetArenaForAllocation()
+  );
   swap(generated_code_info_, other->generated_code_info_);
 }
 
@@ -1268,7 +1288,7 @@ CodeGeneratorResponse::CodeGeneratorResponse(const CodeGeneratorResponse& from)
   error_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_error()) {
     error_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_error(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   supported_features_ = from.supported_features_;
   // @@protoc_insertion_point(copy_constructor:google.protobuf.compiler.CodeGeneratorResponse)
@@ -1276,7 +1296,7 @@ CodeGeneratorResponse::CodeGeneratorResponse(const CodeGeneratorResponse& from)
 
 void CodeGeneratorResponse::SharedCtor() {
 error_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
-supported_features_ = PROTOBUF_ULONGLONG(0);
+supported_features_ = uint64_t{0u};
 }
 
 CodeGeneratorResponse::~CodeGeneratorResponse() {
@@ -1286,7 +1306,7 @@ CodeGeneratorResponse::~CodeGeneratorResponse() {
 }
 
 void CodeGeneratorResponse::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   error_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -1311,7 +1331,7 @@ void CodeGeneratorResponse::Clear() {
   if (cached_has_bits & 0x00000001u) {
     error_.ClearNonDefaultToEmpty();
   }
-  supported_features_ = PROTOBUF_ULONGLONG(0);
+  supported_features_ = uint64_t{0u};
   _has_bits_.Clear();
   _internal_metadata_.Clear<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>();
 }
@@ -1516,7 +1536,11 @@ void CodeGeneratorResponse::InternalSwap(CodeGeneratorResponse* other) {
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
   file_.InternalSwap(&other->file_);
-  error_.Swap(&other->error_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &error_, GetArenaForAllocation(),
+      &other->error_, other->GetArenaForAllocation()
+  );
   swap(supported_features_, other->supported_features_);
 }
 

src/google/protobuf/compiler/plugin.pb.h

@@ -111,7 +111,7 @@ inline bool CodeGeneratorResponse_Feature_Parse(
 }
 // ===================================================================
 
-class PROTOC_EXPORT Version PROTOBUF_FINAL :
+class PROTOC_EXPORT Version final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.compiler.Version) */ {
  public:
   inline Version() : Version(nullptr) {}
@@ -129,8 +129,9 @@ class PROTOC_EXPORT Version PROTOBUF_FINAL :
     return *this;
   }
   inline Version& operator=(Version&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -168,7 +169,7 @@ class PROTOC_EXPORT Version PROTOBUF_FINAL :
   }
   inline void Swap(Version* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -176,14 +177,14 @@ class PROTOC_EXPORT Version PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Version* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Version* New() const final {
-    return CreateMaybeMessage<Version>(nullptr);
+    return new Version();
   }
 
   Version* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -240,11 +241,11 @@ class PROTOC_EXPORT Version PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_suffix(ArgT0&& arg0, ArgT... args);
   std::string* mutable_suffix();
-  std::string* release_suffix();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_suffix();
   void set_allocated_suffix(std::string* suffix);
   private:
   const std::string& _internal_suffix() const;
-  void _internal_set_suffix(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_suffix(const std::string& value);
   std::string* _internal_mutable_suffix();
   public:
 
@@ -304,7 +305,7 @@ class PROTOC_EXPORT Version PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOC_EXPORT CodeGeneratorRequest PROTOBUF_FINAL :
+class PROTOC_EXPORT CodeGeneratorRequest final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.compiler.CodeGeneratorRequest) */ {
  public:
   inline CodeGeneratorRequest() : CodeGeneratorRequest(nullptr) {}
@@ -322,8 +323,9 @@ class PROTOC_EXPORT CodeGeneratorRequest PROTOBUF_FINAL :
     return *this;
   }
   inline CodeGeneratorRequest& operator=(CodeGeneratorRequest&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -361,7 +363,7 @@ class PROTOC_EXPORT CodeGeneratorRequest PROTOBUF_FINAL :
   }
   inline void Swap(CodeGeneratorRequest* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -369,14 +371,14 @@ class PROTOC_EXPORT CodeGeneratorRequest PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(CodeGeneratorRequest* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline CodeGeneratorRequest* New() const final {
-    return CreateMaybeMessage<CodeGeneratorRequest>(nullptr);
+    return new CodeGeneratorRequest();
   }
 
   CodeGeneratorRequest* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -475,11 +477,11 @@ class PROTOC_EXPORT CodeGeneratorRequest PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_parameter(ArgT0&& arg0, ArgT... args);
   std::string* mutable_parameter();
-  std::string* release_parameter();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_parameter();
   void set_allocated_parameter(std::string* parameter);
   private:
   const std::string& _internal_parameter() const;
-  void _internal_set_parameter(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_parameter(const std::string& value);
   std::string* _internal_mutable_parameter();
   public:
 
@@ -518,7 +520,7 @@ class PROTOC_EXPORT CodeGeneratorRequest PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
+class PROTOC_EXPORT CodeGeneratorResponse_File final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.compiler.CodeGeneratorResponse.File) */ {
  public:
   inline CodeGeneratorResponse_File() : CodeGeneratorResponse_File(nullptr) {}
@@ -536,8 +538,9 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
     return *this;
   }
   inline CodeGeneratorResponse_File& operator=(CodeGeneratorResponse_File&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -575,7 +578,7 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
   }
   inline void Swap(CodeGeneratorResponse_File* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -583,14 +586,14 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(CodeGeneratorResponse_File* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline CodeGeneratorResponse_File* New() const final {
-    return CreateMaybeMessage<CodeGeneratorResponse_File>(nullptr);
+    return new CodeGeneratorResponse_File();
   }
 
   CodeGeneratorResponse_File* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -647,11 +650,11 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -665,11 +668,11 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_insertion_point(ArgT0&& arg0, ArgT... args);
   std::string* mutable_insertion_point();
-  std::string* release_insertion_point();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_insertion_point();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_insertion_point(const std::string& value);
   std::string* _internal_mutable_insertion_point();
   public:
 
@@ -683,11 +686,11 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_content(ArgT0&& arg0, ArgT... args);
   std::string* mutable_content();
-  std::string* release_content();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_content();
   void set_allocated_content(std::string* content);
   private:
   const std::string& _internal_content() const;
-  void _internal_set_content(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_content(const std::string& value);
   std::string* _internal_mutable_content();
   public:
 
@@ -726,7 +729,7 @@ class PROTOC_EXPORT CodeGeneratorResponse_File PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOC_EXPORT CodeGeneratorResponse PROTOBUF_FINAL :
+class PROTOC_EXPORT CodeGeneratorResponse final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.compiler.CodeGeneratorResponse) */ {
  public:
   inline CodeGeneratorResponse() : CodeGeneratorResponse(nullptr) {}
@@ -744,8 +747,9 @@ class PROTOC_EXPORT CodeGeneratorResponse PROTOBUF_FINAL :
     return *this;
   }
   inline CodeGeneratorResponse& operator=(CodeGeneratorResponse&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -783,7 +787,7 @@ class PROTOC_EXPORT CodeGeneratorResponse PROTOBUF_FINAL :
   }
   inline void Swap(CodeGeneratorResponse* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -791,14 +795,14 @@ class PROTOC_EXPORT CodeGeneratorResponse PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(CodeGeneratorResponse* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline CodeGeneratorResponse* New() const final {
-    return CreateMaybeMessage<CodeGeneratorResponse>(nullptr);
+    return new CodeGeneratorResponse();
   }
 
   CodeGeneratorResponse* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -904,11 +908,11 @@ class PROTOC_EXPORT CodeGeneratorResponse PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_error(ArgT0&& arg0, ArgT... args);
   std::string* mutable_error();
-  std::string* release_error();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_error();
   void set_allocated_error(std::string* error);
   private:
   const std::string& _internal_error() const;
-  void _internal_set_error(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_error(const std::string& value);
   std::string* _internal_mutable_error();
   public:
 
@@ -1051,10 +1055,10 @@ inline const std::string& Version::suffix() const {
   return _internal_suffix();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Version::set_suffix(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Version::set_suffix(ArgT0&& arg0, ArgT... args) {
  _has_bits_[0] |= 0x00000001u;
- suffix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ suffix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.compiler.Version.suffix)
 }
 inline std::string* Version::mutable_suffix() {
@@ -1066,11 +1070,11 @@ inline const std::string& Version::_internal_suffix() const {
 }
 inline void Version::_internal_set_suffix(const std::string& value) {
   _has_bits_[0] |= 0x00000001u;
-  suffix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  suffix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Version::_internal_mutable_suffix() {
   _has_bits_[0] |= 0x00000001u;
-  return suffix_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return suffix_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Version::release_suffix() {
   // @@protoc_insertion_point(field_release:google.protobuf.compiler.Version.suffix)
@@ -1078,7 +1082,7 @@ inline std::string* Version::release_suffix() {
     return nullptr;
   }
   _has_bits_[0] &= ~0x00000001u;
-  return suffix_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return suffix_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Version::set_allocated_suffix(std::string* suffix) {
   if (suffix != nullptr) {
@@ -1087,7 +1091,7 @@ inline void Version::set_allocated_suffix(std::string* suffix) {
     _has_bits_[0] &= ~0x00000001u;
   }
   suffix_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), suffix,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.Version.suffix)
 }
 
@@ -1186,10 +1190,10 @@ inline const std::string& CodeGeneratorRequest::parameter() const {
   return _internal_parameter();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void CodeGeneratorRequest::set_parameter(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void CodeGeneratorRequest::set_parameter(ArgT0&& arg0, ArgT... args) {
  _has_bits_[0] |= 0x00000001u;
- parameter_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ parameter_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.compiler.CodeGeneratorRequest.parameter)
 }
 inline std::string* CodeGeneratorRequest::mutable_parameter() {
@@ -1201,11 +1205,11 @@ inline const std::string& CodeGeneratorRequest::_internal_parameter() const {
 }
 inline void CodeGeneratorRequest::_internal_set_parameter(const std::string& value) {
   _has_bits_[0] |= 0x00000001u;
-  parameter_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  parameter_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorRequest::_internal_mutable_parameter() {
   _has_bits_[0] |= 0x00000001u;
-  return parameter_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return parameter_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorRequest::release_parameter() {
   // @@protoc_insertion_point(field_release:google.protobuf.compiler.CodeGeneratorRequest.parameter)
@@ -1213,7 +1217,7 @@ inline std::string* CodeGeneratorRequest::release_parameter() {
     return nullptr;
   }
   _has_bits_[0] &= ~0x00000001u;
-  return parameter_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return parameter_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void CodeGeneratorRequest::set_allocated_parameter(std::string* parameter) {
   if (parameter != nullptr) {
@@ -1222,7 +1226,7 @@ inline void CodeGeneratorRequest::set_allocated_parameter(std::string* parameter
     _has_bits_[0] &= ~0x00000001u;
   }
   parameter_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), parameter,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorRequest.parameter)
 }
 
@@ -1286,7 +1290,7 @@ inline const PROTOBUF_NAMESPACE_ID::compiler::Version& CodeGeneratorRequest::com
 }
 inline void CodeGeneratorRequest::unsafe_arena_set_allocated_compiler_version(
     PROTOBUF_NAMESPACE_ID::compiler::Version* compiler_version) {
-  if (GetArena() == nullptr) {
+  if (GetArenaForAllocation() == nullptr) {
     delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(compiler_version_);
   }
   compiler_version_ = compiler_version;
@@ -1301,7 +1305,7 @@ inline PROTOBUF_NAMESPACE_ID::compiler::Version* CodeGeneratorRequest::release_c
   _has_bits_[0] &= ~0x00000002u;
   PROTOBUF_NAMESPACE_ID::compiler::Version* temp = compiler_version_;
   compiler_version_ = nullptr;
-  if (GetArena() != nullptr) {
+  if (GetArenaForAllocation() != nullptr) {
     temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
   }
   return temp;
@@ -1316,7 +1320,7 @@ inline PROTOBUF_NAMESPACE_ID::compiler::Version* CodeGeneratorRequest::unsafe_ar
 inline PROTOBUF_NAMESPACE_ID::compiler::Version* CodeGeneratorRequest::_internal_mutable_compiler_version() {
   _has_bits_[0] |= 0x00000002u;
   if (compiler_version_ == nullptr) {
-    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::compiler::Version>(GetArena());
+    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::compiler::Version>(GetArenaForAllocation());
     compiler_version_ = p;
   }
   return compiler_version_;
@@ -1326,13 +1330,13 @@ inline PROTOBUF_NAMESPACE_ID::compiler::Version* CodeGeneratorRequest::mutable_c
   return _internal_mutable_compiler_version();
 }
 inline void CodeGeneratorRequest::set_allocated_compiler_version(PROTOBUF_NAMESPACE_ID::compiler::Version* compiler_version) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   if (message_arena == nullptr) {
     delete compiler_version_;
   }
   if (compiler_version) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      ::PROTOBUF_NAMESPACE_ID::Arena::GetArena(compiler_version);
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<PROTOBUF_NAMESPACE_ID::compiler::Version>::GetOwningArena(compiler_version);
     if (message_arena != submessage_arena) {
       compiler_version = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, compiler_version, submessage_arena);
@@ -1366,10 +1370,10 @@ inline const std::string& CodeGeneratorResponse_File::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void CodeGeneratorResponse_File::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void CodeGeneratorResponse_File::set_name(ArgT0&& arg0, ArgT... args) {
  _has_bits_[0] |= 0x00000001u;
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.compiler.CodeGeneratorResponse.File.name)
 }
 inline std::string* CodeGeneratorResponse_File::mutable_name() {
@@ -1381,11 +1385,11 @@ inline const std::string& CodeGeneratorResponse_File::_internal_name() const {
 }
 inline void CodeGeneratorResponse_File::_internal_set_name(const std::string& value) {
   _has_bits_[0] |= 0x00000001u;
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse_File::_internal_mutable_name() {
   _has_bits_[0] |= 0x00000001u;
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse_File::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.compiler.CodeGeneratorResponse.File.name)
@@ -1393,7 +1397,7 @@ inline std::string* CodeGeneratorResponse_File::release_name() {
     return nullptr;
   }
   _has_bits_[0] &= ~0x00000001u;
-  return name_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void CodeGeneratorResponse_File::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -1402,7 +1406,7 @@ inline void CodeGeneratorResponse_File::set_allocated_name(std::string* name) {
     _has_bits_[0] &= ~0x00000001u;
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.name)
 }
 
@@ -1423,10 +1427,10 @@ inline const std::string& CodeGeneratorResponse_File::insertion_point() const {
   return _internal_insertion_point();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void CodeGeneratorResponse_File::set_insertion_point(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void CodeGeneratorResponse_File::set_insertion_point(ArgT0&& arg0, ArgT... args) {
  _has_bits_[0] |= 0x00000002u;
- insertion_point_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ insertion_point_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.compiler.CodeGeneratorResponse.File.insertion_point)
 }
 inline std::string* CodeGeneratorResponse_File::mutable_insertion_point() {
@@ -1438,11 +1442,11 @@ inline const std::string& CodeGeneratorResponse_File::_internal_insertion_point(
 }
 inline void CodeGeneratorResponse_File::_internal_set_insertion_point(const std::string& value) {
   _has_bits_[0] |= 0x00000002u;
-  insertion_point_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  insertion_point_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse_File::_internal_mutable_insertion_point() {
   _has_bits_[0] |= 0x00000002u;
-  return insertion_point_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return insertion_point_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse_File::release_insertion_point() {
   // @@protoc_insertion_point(field_release:google.protobuf.compiler.CodeGeneratorResponse.File.insertion_point)
@@ -1450,7 +1454,7 @@ inline std::string* CodeGeneratorResponse_File::release_insertion_point() {
     return nullptr;
   }
   _has_bits_[0] &= ~0x00000002u;
-  return insertion_point_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return insertion_point_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void CodeGeneratorResponse_File::set_allocated_insertion_point(std::string* insertion_point) {
   if (insertion_point != nullptr) {
@@ -1459,7 +1463,7 @@ inline void CodeGeneratorResponse_File::set_allocated_insertion_point(std::strin
     _has_bits_[0] &= ~0x00000002u;
   }
   insertion_point_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), insertion_point,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.insertion_point)
 }
 
@@ -1480,10 +1484,10 @@ inline const std::string& CodeGeneratorResponse_File::content() const {
   return _internal_content();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void CodeGeneratorResponse_File::set_content(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void CodeGeneratorResponse_File::set_content(ArgT0&& arg0, ArgT... args) {
  _has_bits_[0] |= 0x00000004u;
- content_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ content_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.compiler.CodeGeneratorResponse.File.content)
 }
 inline std::string* CodeGeneratorResponse_File::mutable_content() {
@@ -1495,11 +1499,11 @@ inline const std::string& CodeGeneratorResponse_File::_internal_content() const
 }
 inline void CodeGeneratorResponse_File::_internal_set_content(const std::string& value) {
   _has_bits_[0] |= 0x00000004u;
-  content_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  content_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse_File::_internal_mutable_content() {
   _has_bits_[0] |= 0x00000004u;
-  return content_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return content_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse_File::release_content() {
   // @@protoc_insertion_point(field_release:google.protobuf.compiler.CodeGeneratorResponse.File.content)
@@ -1507,7 +1511,7 @@ inline std::string* CodeGeneratorResponse_File::release_content() {
     return nullptr;
   }
   _has_bits_[0] &= ~0x00000004u;
-  return content_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return content_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void CodeGeneratorResponse_File::set_allocated_content(std::string* content) {
   if (content != nullptr) {
@@ -1516,7 +1520,7 @@ inline void CodeGeneratorResponse_File::set_allocated_content(std::string* conte
     _has_bits_[0] &= ~0x00000004u;
   }
   content_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), content,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.File.content)
 }
 
@@ -1540,7 +1544,7 @@ inline const PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo& CodeGeneratorResponse_Fil
 }
 inline void CodeGeneratorResponse_File::unsafe_arena_set_allocated_generated_code_info(
     PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* generated_code_info) {
-  if (GetArena() == nullptr) {
+  if (GetArenaForAllocation() == nullptr) {
     delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(generated_code_info_);
   }
   generated_code_info_ = generated_code_info;
@@ -1555,7 +1559,7 @@ inline PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* CodeGeneratorResponse_File::rel
   _has_bits_[0] &= ~0x00000008u;
   PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* temp = generated_code_info_;
   generated_code_info_ = nullptr;
-  if (GetArena() != nullptr) {
+  if (GetArenaForAllocation() != nullptr) {
     temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
   }
   return temp;
@@ -1570,7 +1574,7 @@ inline PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* CodeGeneratorResponse_File::uns
 inline PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* CodeGeneratorResponse_File::_internal_mutable_generated_code_info() {
   _has_bits_[0] |= 0x00000008u;
   if (generated_code_info_ == nullptr) {
-    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo>(GetArena());
+    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo>(GetArenaForAllocation());
     generated_code_info_ = p;
   }
   return generated_code_info_;
@@ -1580,13 +1584,15 @@ inline PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* CodeGeneratorResponse_File::mut
   return _internal_mutable_generated_code_info();
 }
 inline void CodeGeneratorResponse_File::set_allocated_generated_code_info(PROTOBUF_NAMESPACE_ID::GeneratedCodeInfo* generated_code_info) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   if (message_arena == nullptr) {
     delete reinterpret_cast< ::PROTOBUF_NAMESPACE_ID::MessageLite*>(generated_code_info_);
   }
   if (generated_code_info) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(generated_code_info)->GetArena();
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<
+            ::PROTOBUF_NAMESPACE_ID::MessageLite>::GetOwningArena(
+                reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(generated_code_info));
     if (message_arena != submessage_arena) {
       generated_code_info = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, generated_code_info, submessage_arena);
@@ -1620,10 +1626,10 @@ inline const std::string& CodeGeneratorResponse::error() const {
   return _internal_error();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void CodeGeneratorResponse::set_error(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void CodeGeneratorResponse::set_error(ArgT0&& arg0, ArgT... args) {
  _has_bits_[0] |= 0x00000001u;
- error_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ error_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.compiler.CodeGeneratorResponse.error)
 }
 inline std::string* CodeGeneratorResponse::mutable_error() {
@@ -1635,11 +1641,11 @@ inline const std::string& CodeGeneratorResponse::_internal_error() const {
 }
 inline void CodeGeneratorResponse::_internal_set_error(const std::string& value) {
   _has_bits_[0] |= 0x00000001u;
-  error_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  error_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse::_internal_mutable_error() {
   _has_bits_[0] |= 0x00000001u;
-  return error_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return error_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* CodeGeneratorResponse::release_error() {
   // @@protoc_insertion_point(field_release:google.protobuf.compiler.CodeGeneratorResponse.error)
@@ -1647,7 +1653,7 @@ inline std::string* CodeGeneratorResponse::release_error() {
     return nullptr;
   }
   _has_bits_[0] &= ~0x00000001u;
-  return error_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return error_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void CodeGeneratorResponse::set_allocated_error(std::string* error) {
   if (error != nullptr) {
@@ -1656,7 +1662,7 @@ inline void CodeGeneratorResponse::set_allocated_error(std::string* error) {
     _has_bits_[0] &= ~0x00000001u;
   }
   error_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), error,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.compiler.CodeGeneratorResponse.error)
 }
 
@@ -1669,7 +1675,7 @@ inline bool CodeGeneratorResponse::has_supported_features() const {
   return _internal_has_supported_features();
 }
 inline void CodeGeneratorResponse::clear_supported_features() {
-  supported_features_ = PROTOBUF_ULONGLONG(0);
+  supported_features_ = uint64_t{0u};
   _has_bits_[0] &= ~0x00000002u;
 }
 inline ::PROTOBUF_NAMESPACE_ID::uint64 CodeGeneratorResponse::_internal_supported_features() const {

src/google/protobuf/descriptor.pb.cc

@@ -378,8 +378,8 @@ constexpr UninterpretedOption::UninterpretedOption(
   , identifier_value_(&::PROTOBUF_NAMESPACE_ID::internal::fixed_address_empty_string)
   , string_value_(&::PROTOBUF_NAMESPACE_ID::internal::fixed_address_empty_string)
   , aggregate_value_(&::PROTOBUF_NAMESPACE_ID::internal::fixed_address_empty_string)
-  , positive_int_value_(PROTOBUF_ULONGLONG(0))
-  , negative_int_value_(PROTOBUF_LONGLONG(0))
+  , positive_int_value_(uint64_t{0u})
+  , negative_int_value_(int64_t{0})
   , double_value_(0){}
 struct UninterpretedOptionDefaultTypeInternal {
   constexpr UninterpretedOptionDefaultTypeInternal()
@@ -1262,7 +1262,7 @@ FileDescriptorSet::~FileDescriptorSet() {
 }
 
 void FileDescriptorSet::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void FileDescriptorSet::ArenaDtor(void* object) {
@@ -1487,17 +1487,17 @@ FileDescriptorProto::FileDescriptorProto(const FileDescriptorProto& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   package_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_package()) {
     package_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_package(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   syntax_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_syntax()) {
     syntax_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_syntax(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::FileOptions(*from.options_);
@@ -1529,7 +1529,7 @@ FileDescriptorProto::~FileDescriptorProto() {
 }
 
 void FileDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   package_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   syntax_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -2065,9 +2065,21 @@ void FileDescriptorProto::InternalSwap(FileDescriptorProto* other) {
   extension_.InternalSwap(&other->extension_);
   public_dependency_.InternalSwap(&other->public_dependency_);
   weak_dependency_.InternalSwap(&other->weak_dependency_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  package_.Swap(&other->package_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  syntax_.Swap(&other->syntax_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &package_, GetArenaForAllocation(),
+      &other->package_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &syntax_, GetArenaForAllocation(),
+      &other->syntax_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(FileDescriptorProto, source_code_info_)
       + sizeof(FileDescriptorProto::source_code_info_)
@@ -2138,7 +2150,7 @@ DescriptorProto_ExtensionRange::~DescriptorProto_ExtensionRange() {
 }
 
 void DescriptorProto_ExtensionRange::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   if (this != internal_default_instance()) delete options_;
 }
 
@@ -2421,7 +2433,7 @@ DescriptorProto_ReservedRange::~DescriptorProto_ReservedRange() {
 }
 
 void DescriptorProto_ReservedRange::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void DescriptorProto_ReservedRange::ArenaDtor(void* object) {
@@ -2675,7 +2687,7 @@ DescriptorProto::DescriptorProto(const DescriptorProto& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::MessageOptions(*from.options_);
@@ -2697,7 +2709,7 @@ DescriptorProto::~DescriptorProto() {
 }
 
 void DescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete options_;
 }
@@ -3159,7 +3171,11 @@ void DescriptorProto::InternalSwap(DescriptorProto* other) {
   oneof_decl_.InternalSwap(&other->oneof_decl_);
   reserved_range_.InternalSwap(&other->reserved_range_);
   reserved_name_.InternalSwap(&other->reserved_name_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   swap(options_, other->options_);
 }
 
@@ -3201,7 +3217,7 @@ ExtensionRangeOptions::~ExtensionRangeOptions() {
 }
 
 void ExtensionRangeOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void ExtensionRangeOptions::ArenaDtor(void* object) {
@@ -3444,27 +3460,27 @@ FieldDescriptorProto::FieldDescriptorProto(const FieldDescriptorProto& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   extendee_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_extendee()) {
     extendee_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_extendee(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   type_name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_type_name()) {
     type_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_type_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   default_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_default_value()) {
     default_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_default_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   json_name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_json_name()) {
     json_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_json_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::FieldOptions(*from.options_);
@@ -3498,7 +3514,7 @@ FieldDescriptorProto::~FieldDescriptorProto() {
 }
 
 void FieldDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   extendee_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   type_name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -3989,11 +4005,31 @@ void FieldDescriptorProto::InternalSwap(FieldDescriptorProto* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  extendee_.Swap(&other->extendee_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  type_name_.Swap(&other->type_name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  default_value_.Swap(&other->default_value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  json_name_.Swap(&other->json_name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &extendee_, GetArenaForAllocation(),
+      &other->extendee_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &type_name_, GetArenaForAllocation(),
+      &other->type_name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &default_value_, GetArenaForAllocation(),
+      &other->default_value_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &json_name_, GetArenaForAllocation(),
+      &other->json_name_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(FieldDescriptorProto, proto3_optional_)
       + sizeof(FieldDescriptorProto::proto3_optional_)
@@ -4041,7 +4077,7 @@ OneofDescriptorProto::OneofDescriptorProto(const OneofDescriptorProto& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::OneofOptions(*from.options_);
@@ -4063,7 +4099,7 @@ OneofDescriptorProto::~OneofDescriptorProto() {
 }
 
 void OneofDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete options_;
 }
@@ -4272,7 +4308,11 @@ void OneofDescriptorProto::InternalSwap(OneofDescriptorProto* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   swap(options_, other->options_);
 }
 
@@ -4325,7 +4365,7 @@ EnumDescriptorProto_EnumReservedRange::~EnumDescriptorProto_EnumReservedRange()
 }
 
 void EnumDescriptorProto_EnumReservedRange::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void EnumDescriptorProto_EnumReservedRange::ArenaDtor(void* object) {
@@ -4569,7 +4609,7 @@ EnumDescriptorProto::EnumDescriptorProto(const EnumDescriptorProto& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::EnumOptions(*from.options_);
@@ -4591,7 +4631,7 @@ EnumDescriptorProto::~EnumDescriptorProto() {
 }
 
 void EnumDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete options_;
 }
@@ -4898,7 +4938,11 @@ void EnumDescriptorProto::InternalSwap(EnumDescriptorProto* other) {
   value_.InternalSwap(&other->value_);
   reserved_range_.InternalSwap(&other->reserved_range_);
   reserved_name_.InternalSwap(&other->reserved_name_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   swap(options_, other->options_);
 }
 
@@ -4942,7 +4986,7 @@ EnumValueDescriptorProto::EnumValueDescriptorProto(const EnumValueDescriptorProt
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::EnumValueOptions(*from.options_);
@@ -4968,7 +5012,7 @@ EnumValueDescriptorProto::~EnumValueDescriptorProto() {
 }
 
 void EnumValueDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete options_;
 }
@@ -5203,7 +5247,11 @@ void EnumValueDescriptorProto::InternalSwap(EnumValueDescriptorProto* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(EnumValueDescriptorProto, number_)
       + sizeof(EnumValueDescriptorProto::number_)
@@ -5251,7 +5299,7 @@ ServiceDescriptorProto::ServiceDescriptorProto(const ServiceDescriptorProto& fro
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::ServiceOptions(*from.options_);
@@ -5273,7 +5321,7 @@ ServiceDescriptorProto::~ServiceDescriptorProto() {
 }
 
 void ServiceDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete options_;
 }
@@ -5513,7 +5561,11 @@ void ServiceDescriptorProto::InternalSwap(ServiceDescriptorProto* other) {
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
   method_.InternalSwap(&other->method_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   swap(options_, other->options_);
 }
 
@@ -5566,17 +5618,17 @@ MethodDescriptorProto::MethodDescriptorProto(const MethodDescriptorProto& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   input_type_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_input_type()) {
     input_type_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_input_type(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   output_type_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_output_type()) {
     output_type_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_output_type(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_options()) {
     options_ = new PROTOBUF_NAMESPACE_ID::MethodOptions(*from.options_);
@@ -5606,7 +5658,7 @@ MethodDescriptorProto::~MethodDescriptorProto() {
 }
 
 void MethodDescriptorProto::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   input_type_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   output_type_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -5933,9 +5985,21 @@ void MethodDescriptorProto::InternalSwap(MethodDescriptorProto* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  input_type_.Swap(&other->input_type_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  output_type_.Swap(&other->output_type_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &input_type_, GetArenaForAllocation(),
+      &other->input_type_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &output_type_, GetArenaForAllocation(),
+      &other->output_type_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(MethodDescriptorProto, server_streaming_)
       + sizeof(MethodDescriptorProto::server_streaming_)
@@ -6034,52 +6098,52 @@ FileOptions::FileOptions(const FileOptions& from)
   java_package_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_java_package()) {
     java_package_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_java_package(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   java_outer_classname_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_java_outer_classname()) {
     java_outer_classname_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_java_outer_classname(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   go_package_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_go_package()) {
     go_package_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_go_package(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   objc_class_prefix_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_objc_class_prefix()) {
     objc_class_prefix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_objc_class_prefix(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   csharp_namespace_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_csharp_namespace()) {
     csharp_namespace_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_csharp_namespace(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   swift_prefix_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_swift_prefix()) {
     swift_prefix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_swift_prefix(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   php_class_prefix_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_php_class_prefix()) {
     php_class_prefix_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_php_class_prefix(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   php_namespace_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_php_namespace()) {
     php_namespace_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_php_namespace(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   php_metadata_namespace_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_php_metadata_namespace()) {
     php_metadata_namespace_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_php_metadata_namespace(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ruby_package_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_ruby_package()) {
     ruby_package_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_ruby_package(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ::memcpy(&java_multiple_files_, &from.java_multiple_files_,
     static_cast<size_t>(reinterpret_cast<char*>(&cc_enable_arenas_) -
@@ -6113,7 +6177,7 @@ FileOptions::~FileOptions() {
 }
 
 void FileOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   java_package_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   java_outer_classname_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   go_package_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -6904,16 +6968,56 @@ void FileOptions::InternalSwap(FileOptions* other) {
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
   uninterpreted_option_.InternalSwap(&other->uninterpreted_option_);
-  java_package_.Swap(&other->java_package_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  java_outer_classname_.Swap(&other->java_outer_classname_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  go_package_.Swap(&other->go_package_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  objc_class_prefix_.Swap(&other->objc_class_prefix_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  csharp_namespace_.Swap(&other->csharp_namespace_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  swift_prefix_.Swap(&other->swift_prefix_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  php_class_prefix_.Swap(&other->php_class_prefix_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  php_namespace_.Swap(&other->php_namespace_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  php_metadata_namespace_.Swap(&other->php_metadata_namespace_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  ruby_package_.Swap(&other->ruby_package_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &java_package_, GetArenaForAllocation(),
+      &other->java_package_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &java_outer_classname_, GetArenaForAllocation(),
+      &other->java_outer_classname_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &go_package_, GetArenaForAllocation(),
+      &other->go_package_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &objc_class_prefix_, GetArenaForAllocation(),
+      &other->objc_class_prefix_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &csharp_namespace_, GetArenaForAllocation(),
+      &other->csharp_namespace_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &swift_prefix_, GetArenaForAllocation(),
+      &other->swift_prefix_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &php_class_prefix_, GetArenaForAllocation(),
+      &other->php_class_prefix_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &php_namespace_, GetArenaForAllocation(),
+      &other->php_namespace_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &php_metadata_namespace_, GetArenaForAllocation(),
+      &other->php_metadata_namespace_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &ruby_package_, GetArenaForAllocation(),
+      &other->ruby_package_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(FileOptions, deprecated_)
       + sizeof(FileOptions::deprecated_)
@@ -6983,7 +7087,7 @@ MessageOptions::~MessageOptions() {
 }
 
 void MessageOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void MessageOptions::ArenaDtor(void* object) {
@@ -7336,7 +7440,7 @@ FieldOptions::~FieldOptions() {
 }
 
 void FieldOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void FieldOptions::ArenaDtor(void* object) {
@@ -7721,7 +7825,7 @@ OneofOptions::~OneofOptions() {
 }
 
 void OneofOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void OneofOptions::ArenaDtor(void* object) {
@@ -7953,7 +8057,7 @@ EnumOptions::~EnumOptions() {
 }
 
 void EnumOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void EnumOptions::ArenaDtor(void* object) {
@@ -8242,7 +8346,7 @@ EnumValueOptions::~EnumValueOptions() {
 }
 
 void EnumValueOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void EnumValueOptions::ArenaDtor(void* object) {
@@ -8496,7 +8600,7 @@ ServiceOptions::~ServiceOptions() {
 }
 
 void ServiceOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void ServiceOptions::ArenaDtor(void* object) {
@@ -8758,7 +8862,7 @@ MethodOptions::~MethodOptions() {
 }
 
 void MethodOptions::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void MethodOptions::ArenaDtor(void* object) {
@@ -9046,7 +9150,7 @@ UninterpretedOption_NamePart::UninterpretedOption_NamePart(const UninterpretedOp
   name_part_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_name_part()) {
     name_part_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name_part(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   is_extension_ = from.is_extension_;
   // @@protoc_insertion_point(copy_constructor:google.protobuf.UninterpretedOption.NamePart)
@@ -9064,7 +9168,7 @@ UninterpretedOption_NamePart::~UninterpretedOption_NamePart() {
 }
 
 void UninterpretedOption_NamePart::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_part_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -9278,7 +9382,11 @@ void UninterpretedOption_NamePart::InternalSwap(UninterpretedOption_NamePart* ot
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
-  name_part_.Swap(&other->name_part_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_part_, GetArenaForAllocation(),
+      &other->name_part_, other->GetArenaForAllocation()
+  );
   swap(is_extension_, other->is_extension_);
 }
 
@@ -9328,17 +9436,17 @@ UninterpretedOption::UninterpretedOption(const UninterpretedOption& from)
   identifier_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_identifier_value()) {
     identifier_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_identifier_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   string_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_string_value()) {
     string_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_string_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   aggregate_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_aggregate_value()) {
     aggregate_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_aggregate_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ::memcpy(&positive_int_value_, &from.positive_int_value_,
     static_cast<size_t>(reinterpret_cast<char*>(&double_value_) -
@@ -9363,7 +9471,7 @@ UninterpretedOption::~UninterpretedOption() {
 }
 
 void UninterpretedOption::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   identifier_value_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   string_value_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   aggregate_value_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -9709,9 +9817,21 @@ void UninterpretedOption::InternalSwap(UninterpretedOption* other) {
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
   name_.InternalSwap(&other->name_);
-  identifier_value_.Swap(&other->identifier_value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  string_value_.Swap(&other->string_value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  aggregate_value_.Swap(&other->aggregate_value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &identifier_value_, GetArenaForAllocation(),
+      &other->identifier_value_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &string_value_, GetArenaForAllocation(),
+      &other->string_value_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &aggregate_value_, GetArenaForAllocation(),
+      &other->aggregate_value_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(UninterpretedOption, double_value_)
       + sizeof(UninterpretedOption::double_value_)
@@ -9758,12 +9878,12 @@ SourceCodeInfo_Location::SourceCodeInfo_Location(const SourceCodeInfo_Location&
   leading_comments_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_leading_comments()) {
     leading_comments_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_leading_comments(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   trailing_comments_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_trailing_comments()) {
     trailing_comments_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_trailing_comments(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   // @@protoc_insertion_point(copy_constructor:google.protobuf.SourceCodeInfo.Location)
 }
@@ -9780,7 +9900,7 @@ SourceCodeInfo_Location::~SourceCodeInfo_Location() {
 }
 
 void SourceCodeInfo_Location::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   leading_comments_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   trailing_comments_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
@@ -10102,8 +10222,16 @@ void SourceCodeInfo_Location::InternalSwap(SourceCodeInfo_Location* other) {
   path_.InternalSwap(&other->path_);
   span_.InternalSwap(&other->span_);
   leading_detached_comments_.InternalSwap(&other->leading_detached_comments_);
-  leading_comments_.Swap(&other->leading_comments_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  trailing_comments_.Swap(&other->trailing_comments_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &leading_comments_, GetArenaForAllocation(),
+      &other->leading_comments_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &trailing_comments_, GetArenaForAllocation(),
+      &other->trailing_comments_, other->GetArenaForAllocation()
+  );
 }
 
 ::PROTOBUF_NAMESPACE_ID::Metadata SourceCodeInfo_Location::GetMetadata() const {
@@ -10142,7 +10270,7 @@ SourceCodeInfo::~SourceCodeInfo() {
 }
 
 void SourceCodeInfo::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void SourceCodeInfo::ArenaDtor(void* object) {
@@ -10338,7 +10466,7 @@ GeneratedCodeInfo_Annotation::GeneratedCodeInfo_Annotation(const GeneratedCodeIn
   source_file_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (from._internal_has_source_file()) {
     source_file_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_source_file(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ::memcpy(&begin_, &from.begin_,
     static_cast<size_t>(reinterpret_cast<char*>(&end_) -
@@ -10361,7 +10489,7 @@ GeneratedCodeInfo_Annotation::~GeneratedCodeInfo_Annotation() {
 }
 
 void GeneratedCodeInfo_Annotation::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   source_file_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -10626,7 +10754,11 @@ void GeneratedCodeInfo_Annotation::InternalSwap(GeneratedCodeInfo_Annotation* ot
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   swap(_has_bits_[0], other->_has_bits_[0]);
   path_.InternalSwap(&other->path_);
-  source_file_.Swap(&other->source_file_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &source_file_, GetArenaForAllocation(),
+      &other->source_file_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(GeneratedCodeInfo_Annotation, end_)
       + sizeof(GeneratedCodeInfo_Annotation::end_)
@@ -10671,7 +10803,7 @@ GeneratedCodeInfo::~GeneratedCodeInfo() {
 }
 
 void GeneratedCodeInfo::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void GeneratedCodeInfo::ArenaDtor(void* object) {

src/google/protobuf/descriptor_unittest.cc

@@ -2071,6 +2071,84 @@ TEST_F(ExtensionDescriptorTest, DuplicateFieldNumber) {
 
 // ===================================================================
 
+// Ensure that overlapping extension ranges are not allowed.
+TEST(OverlappingExtensionRangeTest, ExtensionRangeInternal) {
+  // Build descriptors for the following definitions:
+  //
+  //   message Foo {
+  //     extensions 10 to 19;
+  //     extensions 15;
+  //   }
+  FileDescriptorProto foo_file;
+  foo_file.set_name("foo.proto");
+
+  DescriptorProto* foo = AddMessage(&foo_file, "Foo");
+  AddExtensionRange(foo, 10, 20);
+  AddExtensionRange(foo, 15, 16);
+
+  DescriptorPool pool;
+  MockErrorCollector error_collector;
+  // The extensions ranges are invalid, so the proto shouldn't build.
+  ASSERT_TRUE(pool.BuildFileCollectingErrors(foo_file, &error_collector) ==
+              nullptr);
+  ASSERT_EQ(
+      "foo.proto: Foo: NUMBER: Extension range 15 to 15 overlaps with "
+      "already-defined range 10 to 19.\n",
+      error_collector.text_);
+}
+
+TEST(OverlappingExtensionRangeTest, ExtensionRangeAfter) {
+  // Build descriptors for the following definitions:
+  //
+  //   message Foo {
+  //     extensions 10 to 19;
+  //     extensions 15 to 24;
+  //   }
+  FileDescriptorProto foo_file;
+  foo_file.set_name("foo.proto");
+
+  DescriptorProto* foo = AddMessage(&foo_file, "Foo");
+  AddExtensionRange(foo, 10, 20);
+  AddExtensionRange(foo, 15, 25);
+
+  DescriptorPool pool;
+  MockErrorCollector error_collector;
+  // The extensions ranges are invalid, so the proto shouldn't build.
+  ASSERT_TRUE(pool.BuildFileCollectingErrors(foo_file, &error_collector) ==
+              nullptr);
+  ASSERT_EQ(
+      "foo.proto: Foo: NUMBER: Extension range 15 to 24 overlaps with "
+      "already-defined range 10 to 19.\n",
+      error_collector.text_);
+}
+
+TEST(OverlappingExtensionRangeTest, ExtensionRangeBefore) {
+  // Build descriptors for the following definitions:
+  //
+  //   message Foo {
+  //     extensions 10 to 19;
+  //     extensions 5 to 14;
+  //   }
+  FileDescriptorProto foo_file;
+  foo_file.set_name("foo.proto");
+
+  DescriptorProto* foo = AddMessage(&foo_file, "Foo");
+  AddExtensionRange(foo, 10, 20);
+  AddExtensionRange(foo, 5, 15);
+
+  DescriptorPool pool;
+  MockErrorCollector error_collector;
+  // The extensions ranges are invalid, so the proto shouldn't build.
+  ASSERT_TRUE(pool.BuildFileCollectingErrors(foo_file, &error_collector) ==
+              nullptr);
+  ASSERT_EQ(
+      "foo.proto: Foo: NUMBER: Extension range 5 to 14 overlaps with "
+      "already-defined range 10 to 19.\n",
+      error_collector.text_);
+}
+
+// ===================================================================
+
 // Test reserved fields.
 class ReservedDescriptorTest : public testing::Test {
  protected:

src/google/protobuf/duration.pb.cc

@@ -19,7 +19,7 @@ PROTOBUF_PRAGMA_INIT_SEG
 PROTOBUF_NAMESPACE_OPEN
 constexpr Duration::Duration(
   ::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized)
-  : seconds_(PROTOBUF_LONGLONG(0))
+  : seconds_(int64_t{0})
   , nanos_(0){}
 struct DurationDefaultTypeInternal {
   constexpr DurationDefaultTypeInternal()
@@ -110,7 +110,7 @@ Duration::~Duration() {
 }
 
 void Duration::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void Duration::ArenaDtor(void* object) {

src/google/protobuf/duration.pb.h

@@ -65,7 +65,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT Duration PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Duration final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Duration) */ {
  public:
   inline Duration() : Duration(nullptr) {}
@@ -83,8 +83,9 @@ class PROTOBUF_EXPORT Duration PROTOBUF_FINAL :
     return *this;
   }
   inline Duration& operator=(Duration&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -115,7 +116,7 @@ class PROTOBUF_EXPORT Duration PROTOBUF_FINAL :
   }
   inline void Swap(Duration* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -123,14 +124,14 @@ class PROTOBUF_EXPORT Duration PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Duration* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Duration* New() const final {
-    return CreateMaybeMessage<Duration>(nullptr);
+    return new Duration();
   }
 
   Duration* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -218,7 +219,7 @@ class PROTOBUF_EXPORT Duration PROTOBUF_FINAL :
 
 // int64 seconds = 1;
 inline void Duration::clear_seconds() {
-  seconds_ = PROTOBUF_LONGLONG(0);
+  seconds_ = int64_t{0};
 }
 inline ::PROTOBUF_NAMESPACE_ID::int64 Duration::_internal_seconds() const {
   return seconds_;

src/google/protobuf/dynamic_message.cc

@@ -355,7 +355,7 @@ void DynamicMessage::SharedCtor(bool lock_factory) {
 
   if (type_info_->extensions_offset != -1) {
     new (OffsetToPointer(type_info_->extensions_offset))
-        ExtensionSet(GetArena());
+        ExtensionSet(GetArenaForAllocation());
   }
   for (int i = 0; i < descriptor->field_count(); i++) {
     const FieldDescriptor* field = descriptor->field(i);
@@ -364,13 +364,13 @@ void DynamicMessage::SharedCtor(bool lock_factory) {
       continue;
     }
     switch (field->cpp_type()) {
-#define HANDLE_TYPE(CPPTYPE, TYPE)                         \
-  case FieldDescriptor::CPPTYPE_##CPPTYPE:                 \
-    if (!field->is_repeated()) {                           \
-      new (field_ptr) TYPE(field->default_value_##TYPE()); \
-    } else {                                               \
-      new (field_ptr) RepeatedField<TYPE>(GetArena());     \
-    }                                                      \
+#define HANDLE_TYPE(CPPTYPE, TYPE)                                  \
+  case FieldDescriptor::CPPTYPE_##CPPTYPE:                          \
+    if (!field->is_repeated()) {                                    \
+      new (field_ptr) TYPE(field->default_value_##TYPE());          \
+    } else {                                                        \
+      new (field_ptr) RepeatedField<TYPE>(GetArenaForAllocation()); \
+    }                                                               \
     break;
 
       HANDLE_TYPE(INT32, int32);
@@ -386,7 +386,7 @@ void DynamicMessage::SharedCtor(bool lock_factory) {
         if (!field->is_repeated()) {
           new (field_ptr) int(field->default_value_enum()->number());
         } else {
-          new (field_ptr) RepeatedField<int>(GetArena());
+          new (field_ptr) RepeatedField<int>(GetArenaForAllocation());
         }
         break;
 
@@ -402,7 +402,8 @@ void DynamicMessage::SharedCtor(bool lock_factory) {
               ArenaStringPtr* asp = new (field_ptr) ArenaStringPtr();
               asp->UnsafeSetDefault(default_value);
             } else {
-              new (field_ptr) RepeatedPtrField<std::string>(GetArena());
+              new (field_ptr)
+                  RepeatedPtrField<std::string>(GetArenaForAllocation());
             }
             break;
         }
@@ -417,20 +418,30 @@ void DynamicMessage::SharedCtor(bool lock_factory) {
             // when the constructor is called inside GetPrototype(), in which
             // case we have already locked the factory.
             if (lock_factory) {
-              if (GetArena() != nullptr) {
+              if (GetArenaForAllocation() != nullptr) {
                 new (field_ptr) DynamicMapField(
                     type_info_->factory->GetPrototype(field->message_type()),
-                    GetArena());
+                    GetArenaForAllocation());
+                if (GetOwningArena() != nullptr) {
+                  // Needs to destroy the mutex member.
+                  GetOwningArena()->OwnDestructor(
+                      static_cast<DynamicMapField*>(field_ptr));
+                }
               } else {
                 new (field_ptr) DynamicMapField(
                     type_info_->factory->GetPrototype(field->message_type()));
               }
             } else {
-              if (GetArena() != nullptr) {
+              if (GetArenaForAllocation() != nullptr) {
                 new (field_ptr)
                     DynamicMapField(type_info_->factory->GetPrototypeNoLock(
                                         field->message_type()),
-                                    GetArena());
+                                    GetArenaForAllocation());
+                if (GetOwningArena() != nullptr) {
+                  // Needs to destroy the mutex member.
+                  GetOwningArena()->OwnDestructor(
+                      static_cast<DynamicMapField*>(field_ptr));
+                }
               } else {
                 new (field_ptr)
                     DynamicMapField(type_info_->factory->GetPrototypeNoLock(
@@ -438,7 +449,7 @@ void DynamicMessage::SharedCtor(bool lock_factory) {
               }
             }
           } else {
-            new (field_ptr) RepeatedPtrField<Message>(GetArena());
+            new (field_ptr) RepeatedPtrField<Message>(GetArenaForAllocation());
           }
         }
         break;

src/google/protobuf/dynamic_message_unittest.cc

@@ -286,6 +286,7 @@ TEST_F(DynamicMessageTest, Arena) {
   // Return without freeing: should not leak.
 }
 
+
 TEST_F(DynamicMessageTest, Proto3) {
   Message* message = proto3_prototype_->New();
   const Reflection* refl = message->GetReflection();

src/google/protobuf/empty.pb.cc

@@ -98,7 +98,7 @@ Empty::~Empty() {
 }
 
 void Empty::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void Empty::ArenaDtor(void* object) {

src/google/protobuf/empty.pb.h

@@ -65,7 +65,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT Empty PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Empty final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Empty) */ {
  public:
   inline Empty() : Empty(nullptr) {}
@@ -83,8 +83,9 @@ class PROTOBUF_EXPORT Empty PROTOBUF_FINAL :
     return *this;
   }
   inline Empty& operator=(Empty&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -115,7 +116,7 @@ class PROTOBUF_EXPORT Empty PROTOBUF_FINAL :
   }
   inline void Swap(Empty* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -123,14 +124,14 @@ class PROTOBUF_EXPORT Empty PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Empty* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Empty* New() const final {
-    return CreateMaybeMessage<Empty>(nullptr);
+    return new Empty();
   }
 
   Empty* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {

src/google/protobuf/extension_set.cc

@@ -616,7 +616,7 @@ void ExtensionSet::SetAllocatedMessage(int number, FieldType type,
     ClearExtension(number);
     return;
   }
-  Arena* message_arena = message->GetArena();
+  Arena* message_arena = message->GetOwningArena();
   Extension* extension;
   if (MaybeNewExtension(number, descriptor, &extension)) {
     extension->type = type;
@@ -1071,6 +1071,7 @@ void ExtensionSet::Swap(ExtensionSet* x) {
 
 void ExtensionSet::InternalSwap(ExtensionSet* other) {
   using std::swap;
+  swap(arena_, other->arena_);
   swap(flat_capacity_, other->flat_capacity_);
   swap(flat_size_, other->flat_size_);
   swap(map_, other->map_);

src/google/protobuf/extension_set.h

@@ -282,12 +282,13 @@ class PROTOBUF_EXPORT ExtensionSet {
   void UnsafeArenaSetAllocatedMessage(int number, FieldType type,
                                       const FieldDescriptor* descriptor,
                                       MessageLite* message);
-  MessageLite* ReleaseMessage(int number, const MessageLite& prototype);
+  PROTOBUF_FUTURE_MUST_USE_RESULT MessageLite* ReleaseMessage(
+      int number, const MessageLite& prototype);
   MessageLite* UnsafeArenaReleaseMessage(int number,
                                          const MessageLite& prototype);
 
-  MessageLite* ReleaseMessage(const FieldDescriptor* descriptor,
-                              MessageFactory* factory);
+  PROTOBUF_FUTURE_MUST_USE_RESULT MessageLite* ReleaseMessage(
+      const FieldDescriptor* descriptor, MessageFactory* factory);
   MessageLite* UnsafeArenaReleaseMessage(const FieldDescriptor* descriptor,
                                          MessageFactory* factory);
 #undef desc
@@ -354,7 +355,7 @@ class PROTOBUF_EXPORT ExtensionSet {
 #undef desc
 
   void RemoveLast(int number);
-  MessageLite* ReleaseLast(int number);
+  PROTOBUF_FUTURE_MUST_USE_RESULT MessageLite* ReleaseLast(int number);
   void SwapElements(int number, int index1, int index2);
 
   // -----------------------------------------------------------------
@@ -534,7 +535,8 @@ class PROTOBUF_EXPORT ExtensionSet {
     virtual MessageLite* MutableMessage(const MessageLite& prototype) = 0;
     virtual void SetAllocatedMessage(MessageLite* message) = 0;
     virtual void UnsafeArenaSetAllocatedMessage(MessageLite* message) = 0;
-    virtual MessageLite* ReleaseMessage(const MessageLite& prototype) = 0;
+    virtual PROTOBUF_FUTURE_MUST_USE_RESULT MessageLite* ReleaseMessage(
+        const MessageLite& prototype) = 0;
     virtual MessageLite* UnsafeArenaReleaseMessage(
         const MessageLite& prototype) = 0;
 
@@ -1260,8 +1262,8 @@ class MessageTypeTraits {
                                              ExtensionSet* set) {
     set->UnsafeArenaSetAllocatedMessage(number, field_type, NULL, message);
   }
-  static inline MutableType Release(int number, FieldType /* field_type */,
-                                    ExtensionSet* set) {
+  static inline PROTOBUF_FUTURE_MUST_USE_RESULT MutableType
+  Release(int number, FieldType /* field_type */, ExtensionSet* set) {
     return static_cast<Type*>(
         set->ReleaseMessage(number, Type::default_instance()));
   }
@@ -1476,9 +1478,11 @@ class ExtensionIdentifier {
   template <typename _proto_TypeTraits,                                       \
             ::PROTOBUF_NAMESPACE_ID::internal::FieldType _field_type,         \
             bool _is_packed>                                                  \
-  inline typename _proto_TypeTraits::Singular::MutableType ReleaseExtension(  \
-      const ::PROTOBUF_NAMESPACE_ID::internal::ExtensionIdentifier<           \
-          CLASSNAME, _proto_TypeTraits, _field_type, _is_packed>& id) {       \
+  inline PROTOBUF_FUTURE_MUST_USE_RESULT                                      \
+      typename _proto_TypeTraits::Singular::MutableType                       \
+      ReleaseExtension(                                                       \
+          const ::PROTOBUF_NAMESPACE_ID::internal::ExtensionIdentifier<       \
+              CLASSNAME, _proto_TypeTraits, _field_type, _is_packed>& id) {   \
     return _proto_TypeTraits::Release(id.number(), _field_type,               \
                                       &_extensions_);                         \
   }                                                                           \

src/google/protobuf/field_mask.pb.cc

@@ -103,7 +103,7 @@ FieldMask::~FieldMask() {
 }
 
 void FieldMask::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void FieldMask::ArenaDtor(void* object) {

src/google/protobuf/field_mask.pb.h

@@ -65,7 +65,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT FieldMask PROTOBUF_FINAL :
+class PROTOBUF_EXPORT FieldMask final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.FieldMask) */ {
  public:
   inline FieldMask() : FieldMask(nullptr) {}
@@ -83,8 +83,9 @@ class PROTOBUF_EXPORT FieldMask PROTOBUF_FINAL :
     return *this;
   }
   inline FieldMask& operator=(FieldMask&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -115,7 +116,7 @@ class PROTOBUF_EXPORT FieldMask PROTOBUF_FINAL :
   }
   inline void Swap(FieldMask* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -123,14 +124,14 @@ class PROTOBUF_EXPORT FieldMask PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(FieldMask* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline FieldMask* New() const final {
-    return CreateMaybeMessage<FieldMask>(nullptr);
+    return new FieldMask();
   }
 
   FieldMask* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {

src/google/protobuf/generated_message_reflection.cc

@@ -235,6 +235,16 @@ UnknownFieldSet* Reflection::MutableUnknownFields(Message* message) const {
       ->mutable_unknown_fields<UnknownFieldSet>();
 }
 
+bool Reflection::IsLazilyVerifiedLazyField(const FieldDescriptor* field) const {
+  return field->options().lazy();
+}
+
+bool Reflection::IsEagerlyVerifiedLazyField(
+    const FieldDescriptor* field) const {
+  return (field->type() == FieldDescriptor::TYPE_MESSAGE &&
+          schema_.IsEagerlyVerifiedLazyField(field));
+}
+
 size_t Reflection::SpaceUsedLong(const Message& message) const {
   // object_size_ already includes the in-memory representation of each field
   // in the message, so we only need to account for additional memory used by
@@ -411,7 +421,8 @@ void Reflection::SwapField(Message* message1, Message* message2,
       SWAP_VALUES(ENUM, int);
 #undef SWAP_VALUES
       case FieldDescriptor::CPPTYPE_MESSAGE:
-        if (GetArena(message1) == GetArena(message2)) {
+        if (message1->GetArenaForAllocation() ==
+            message2->GetArenaForAllocation()) {
           std::swap(*MutableRaw<Message*>(message1, field),
                     *MutableRaw<Message*>(message2, field));
         } else {
@@ -423,13 +434,17 @@ void Reflection::SwapField(Message* message1, Message* message2,
             break;
           }
           if (*sub_msg1 == nullptr) {
-            *sub_msg1 = (*sub_msg2)->New(message1->GetArena());
+            *sub_msg1 = (*sub_msg2)->New(message1->GetArenaForAllocation());
             (*sub_msg1)->CopyFrom(**sub_msg2);
             ClearField(message2, field);
+            // Ensures has bit is unchanged after ClearField.
+            SetBit(message2, field);
           } else {
-            *sub_msg2 = (*sub_msg1)->New(message2->GetArena());
+            *sub_msg2 = (*sub_msg1)->New(message2->GetArenaForAllocation());
             (*sub_msg2)->CopyFrom(**sub_msg1);
             ClearField(message1, field);
+            // Ensures has bit is unchanged after ClearField.
+            SetBit(message1, field);
           }
         }
         break;
@@ -438,25 +453,30 @@ void Reflection::SwapField(Message* message1, Message* message2,
         switch (field->options().ctype()) {
           default:  // TODO(kenton):  Support other string reps.
           case FieldOptions::STRING: {
-            Arena* arena1 = GetArena(message1);
-            Arena* arena2 = GetArena(message2);
+            const std::string* default_ptr =
+                DefaultRaw<ArenaStringPtr>(field).GetPointer();
+            Arena* arena1 = message1->GetArenaForAllocation();
+            Arena* arena2 = message2->GetArenaForAllocation();
 
             ArenaStringPtr* string1 =
                 MutableRaw<ArenaStringPtr>(message1, field);
             ArenaStringPtr* string2 =
                 MutableRaw<ArenaStringPtr>(message2, field);
-            const std::string* default_ptr =
-                DefaultRaw<ArenaStringPtr>(field).GetPointer();
-            if (arena1 == arena2) {
-              string1->Swap(string2, default_ptr, arena1);
+            if (message1->GetOwningArena() == message2->GetOwningArena()) {
+              ArenaStringPtr::InternalSwap(default_ptr, string1, arena1,
+                                           string2, arena2);
             } else if (string1->IsDefault(default_ptr) &&
                        string2->IsDefault(default_ptr)) {
               // Nothing to do.
             } else if (string1->IsDefault(default_ptr)) {
               string1->Set(default_ptr, string2->Get(), arena1);
+              // string2 needs to be destroyed before overwritten.
+              string2->Destroy(default_ptr, arena2);
               string2->UnsafeSetDefault(default_ptr);
             } else if (string2->IsDefault(default_ptr)) {
               string2->Set(default_ptr, string1->Get(), arena2);
+              // string1 needs to be destroyed before overwritten.
+              string1->Destroy(default_ptr, arena1);
               string1->UnsafeSetDefault(default_ptr);
             } else {
               std::string temp = string1->Get();
@@ -612,19 +632,38 @@ void Reflection::Swap(Message* message1, Message* message2) const {
 
   // Check that both messages are in the same arena (or both on the heap). We
   // need to copy all data if not, due to ownership semantics.
-  if (GetArena(message1) != GetArena(message2)) {
-    // Slow copy path.
-    // Use our arena as temp space, if available.
-    Message* temp = message1->New(GetArena(message1));
+  if (message1->GetOwningArena() != message2->GetOwningArena()) {
+    // One of the two is guaranteed to have an arena.  Switch things around
+    // to guarantee that message1 has an arena.
+    Arena* arena = message1->GetOwningArena();
+    if (arena == nullptr) {
+      arena = message2->GetOwningArena();
+      std::swap(message1, message2);  // Swapping names for pointers!
+    }
+
+    Message* temp = message1->New(arena);
     temp->MergeFrom(*message2);
     message2->CopyFrom(*message1);
     Swap(message1, temp);
-    if (GetArena(message1) == nullptr) {
-      delete temp;
-    }
     return;
   }
 
+  for (int i = 0; i <= last_non_weak_field_index_; i++) {
+    const FieldDescriptor* field = descriptor_->field(i);
+    if (schema_.InRealOneof(field)) continue;
+    if (schema_.IsFieldStripped(field)) continue;
+    SwapField(message1, message2, field);
+  }
+  const int oneof_decl_count = descriptor_->oneof_decl_count();
+  for (int i = 0; i < oneof_decl_count; i++) {
+    const OneofDescriptor* oneof = descriptor_->oneof_decl(i);
+    if (!oneof->is_synthetic()) {
+      SwapOneofField(message1, message2, oneof);
+    }
+  }
+
+  // Swapping bits need to happen after swapping fields, because the latter may
+  // depend on the has bit information.
   if (schema_.HasHasbits()) {
     uint32* has_bits1 = MutableHasBits(message1);
     uint32* has_bits2 = MutableHasBits(message2);
@@ -645,20 +684,6 @@ void Reflection::Swap(Message* message1, Message* message2) const {
     }
   }
 
-  for (int i = 0; i <= last_non_weak_field_index_; i++) {
-    const FieldDescriptor* field = descriptor_->field(i);
-    if (schema_.InRealOneof(field)) continue;
-    if (schema_.IsFieldStripped(field)) continue;
-    SwapField(message1, message2, field);
-  }
-  const int oneof_decl_count = descriptor_->oneof_decl_count();
-  for (int i = 0; i < oneof_decl_count; i++) {
-    const OneofDescriptor* oneof = descriptor_->oneof_decl(i);
-    if (!oneof->is_synthetic()) {
-      SwapOneofField(message1, message2, oneof);
-    }
-  }
-
   if (schema_.HasExtensionSet()) {
     MutableExtensionSet(message1)->Swap(MutableExtensionSet(message2));
   }
@@ -708,13 +733,14 @@ void Reflection::SwapFields(
         swapped_oneof.insert(oneof_index);
         SwapOneofField(message1, message2, field->containing_oneof());
       } else {
+        // Swap field.
+        SwapField(message1, message2, field);
         // Swap has bit for non-repeated fields.  We have already checked for
-        // oneof already.
+        // oneof already. This has to be done after SwapField, because SwapField
+        // may depend on the information in has bits.
         if (!field->is_repeated()) {
           SwapBit(message1, message2, field);
         }
-        // Swap field.
-        SwapField(message1, message2, field);
       }
     }
   }
@@ -828,7 +854,8 @@ void Reflection::ClearField(Message* message,
               const std::string* default_ptr =
                   DefaultRaw<ArenaStringPtr>(field).GetPointer();
               MutableRaw<ArenaStringPtr>(message, field)
-                  ->SetAllocated(default_ptr, nullptr, GetArena(message));
+                  ->SetAllocated(default_ptr, nullptr,
+                                 message->GetArenaForAllocation());
               break;
             }
           }
@@ -839,7 +866,7 @@ void Reflection::ClearField(Message* message,
           if (schema_.HasBitIndex(field) == static_cast<uint32>(-1)) {
             // Proto3 does not have has-bits and we need to set a message field
             // to nullptr in order to indicate its un-presence.
-            if (GetArena(message) == nullptr) {
+            if (message->GetArenaForAllocation() == nullptr) {
               delete *MutableRaw<Message*>(message, field);
             }
             *MutableRaw<Message*>(message, field) = nullptr;
@@ -1242,7 +1269,8 @@ void Reflection::SetString(Message* message, const FieldDescriptor* field,
               ->UnsafeSetDefault(default_ptr);
         }
         MutableField<ArenaStringPtr>(message, field)
-            ->Set(default_ptr, std::move(value), GetArena(message));
+            ->Set(default_ptr, std::move(value),
+                  message->GetArenaForAllocation());
         break;
       }
     }
@@ -1494,7 +1522,7 @@ const Message* Reflection::GetDefaultMessageInstance(
   // This is an optimization to avoid going to GetPrototype() below, as that
   // requires a lock and a map lookup.
   if (!field->is_extension() && !field->options().weak() &&
-      !field->options().lazy() && !schema_.InRealOneof(field)) {
+      !IsLazyField(field) && !schema_.InRealOneof(field)) {
     auto* res = DefaultRaw<const Message*>(field);
     if (res != nullptr) {
       return res;
@@ -1548,7 +1576,7 @@ Message* Reflection::MutableMessage(Message* message,
         ClearOneof(message, field->containing_oneof());
         result_holder = MutableField<Message*>(message, field);
         const Message* default_message = GetDefaultMessageInstance(field);
-        *result_holder = default_message->New(message->GetArena());
+        *result_holder = default_message->New(message->GetArenaForAllocation());
       }
     } else {
       SetBit(message, field);
@@ -1556,7 +1584,7 @@ Message* Reflection::MutableMessage(Message* message,
 
     if (*result_holder == nullptr) {
       const Message* default_message = GetDefaultMessageInstance(field);
-      *result_holder = default_message->New(message->GetArena());
+      *result_holder = default_message->New(message->GetArenaForAllocation());
     }
     result = *result_holder;
     return result;
@@ -1590,7 +1618,7 @@ void Reflection::UnsafeArenaSetAllocatedMessage(
       SetBit(message, field);
     }
     Message** sub_message_holder = MutableRaw<Message*>(message, field);
-    if (GetArena(message) == nullptr) {
+    if (message->GetArenaForAllocation() == nullptr) {
       delete *sub_message_holder;
     }
     *sub_message_holder = sub_message;
@@ -1605,12 +1633,13 @@ void Reflection::SetAllocatedMessage(Message* message, Message* sub_message,
   // (different arenas, or one is on heap and one is not), then we may need to
   // do a copy.
   if (sub_message != nullptr &&
-      sub_message->GetArena() != message->GetArena()) {
-    if (sub_message->GetArena() == nullptr && message->GetArena() != nullptr) {
+      sub_message->GetOwningArena() != message->GetArenaForAllocation()) {
+    if (sub_message->GetOwningArena() == nullptr &&
+        message->GetArenaForAllocation() != nullptr) {
       // Case 1: parent is on an arena and child is heap-allocated. We can add
       // the child to the arena's Own() list to free on arena destruction, then
       // set our pointer.
-      message->GetArena()->Own(sub_message);
+      message->GetArenaForAllocation()->Own(sub_message);
       UnsafeArenaSetAllocatedMessage(message, sub_message, field);
     } else {
       // Case 2: all other cases. We need to make a copy. MutableMessage() will
@@ -1661,7 +1690,7 @@ Message* Reflection::ReleaseMessage(Message* message,
   CheckInvalidAccess(schema_, field);
 
   Message* released = UnsafeArenaReleaseMessage(message, field, factory);
-  if (GetArena(message) != nullptr && released != nullptr) {
+  if (message->GetArenaForAllocation() != nullptr && released != nullptr) {
     Message* copy_from_arena = released->New();
     copy_from_arena->CopyFrom(*released);
     released = copy_from_arena;
@@ -1743,7 +1772,7 @@ Message* Reflection::AddMessage(Message* message, const FieldDescriptor* field,
       } else {
         prototype = &repeated->Get<GenericTypeHandler<Message> >(0);
       }
-      result = prototype->New(message->GetArena());
+      result = prototype->New(message->GetArenaForAllocation());
       // We can guarantee here that repeated and result are either both heap
       // allocated or arena owned. So it is safe to call the unsafe version
       // of AddAllocated.
@@ -1988,10 +2017,6 @@ ExtensionSet* Reflection::MutableExtensionSet(Message* message) const {
                                           schema_.GetExtensionSetOffset());
 }
 
-Arena* Reflection::GetArena(Message* message) const {
-  return GetInternalMetadata(*message).arena();
-}
-
 const InternalMetadata& Reflection::GetInternalMetadata(
     const Message& message) const {
   return GetConstRefAtOffset<InternalMetadata>(message,
@@ -2137,7 +2162,7 @@ void Reflection::ClearOneof(Message* message,
   uint32 oneof_case = GetOneofCase(*message, oneof_descriptor);
   if (oneof_case > 0) {
     const FieldDescriptor* field = descriptor_->FindFieldByNumber(oneof_case);
-    if (GetArena(message) == nullptr) {
+    if (message->GetArenaForAllocation() == nullptr) {
       switch (field->cpp_type()) {
         case FieldDescriptor::CPPTYPE_STRING: {
           switch (field->options().ctype()) {
@@ -2148,7 +2173,7 @@ void Reflection::ClearOneof(Message* message,
               // work. This allows us to not have the real default accessible
               // from reflection.
               MutableField<ArenaStringPtr>(message, field)
-                  ->Destroy(nullptr, GetArena(message));
+                  ->Destroy(nullptr, message->GetArenaForAllocation());
               break;
             }
           }

src/google/protobuf/generated_message_reflection.h

@@ -198,6 +198,13 @@ struct ReflectionSchema {
            OffsetValue(offsets_[field->index()], field->type());
   }
 
+  // Returns true if the field is implicitly backed by LazyField.
+  bool IsEagerlyVerifiedLazyField(const FieldDescriptor* field) const {
+    GOOGLE_DCHECK_EQ(field->type(), FieldDescriptor::TYPE_MESSAGE);
+    (void)field;
+    return false;
+  }
+
   // Returns true if the field's accessor is called by any external code (aka,
   // non proto library code).
   bool IsFieldUsed(const FieldDescriptor* field) const {
@@ -235,8 +242,11 @@ struct ReflectionSchema {
   int weak_field_map_offset_;
 
   // We tag offset values to provide additional data about fields (such as
-  // "unused").
-  static uint32 OffsetValue(uint32 v, FieldDescriptor::Type /* type */) {
+  // "unused" or "lazy").
+  static uint32 OffsetValue(uint32 v, FieldDescriptor::Type type) {
+    if (type == FieldDescriptor::TYPE_MESSAGE) {
+      return v & 0x7FFFFFFEu;
+    }
     return v & 0x7FFFFFFFu;
   }
 };

src/google/protobuf/generated_message_reflection_unittest.cc

@@ -266,6 +266,39 @@ TEST(GeneratedMessageReflectionTest, SwapFieldsAll) {
   TestUtil::ExpectClear(message2);
 }
 
+TEST(GeneratedMessageReflectionTest, SwapFieldsAllOnDifferentArena) {
+  Arena arena1, arena2;
+  auto* message1 = Arena::CreateMessage<unittest::TestAllTypes>(&arena1);
+  auto* message2 = Arena::CreateMessage<unittest::TestAllTypes>(&arena2);
+
+  TestUtil::SetAllFields(message2);
+
+  std::vector<const FieldDescriptor*> fields;
+  const Reflection* reflection = message1->GetReflection();
+  reflection->ListFields(*message2, &fields);
+  reflection->SwapFields(message1, message2, fields);
+
+  TestUtil::ExpectAllFieldsSet(*message1);
+  TestUtil::ExpectClear(*message2);
+}
+
+TEST(GeneratedMessageReflectionTest, SwapFieldsAllOnArenaHeap) {
+  Arena arena;
+  auto* message1 = Arena::CreateMessage<unittest::TestAllTypes>(&arena);
+  std::unique_ptr<unittest::TestAllTypes> message2(
+      Arena::CreateMessage<unittest::TestAllTypes>(nullptr));
+
+  TestUtil::SetAllFields(message2.get());
+
+  std::vector<const FieldDescriptor*> fields;
+  const Reflection* reflection = message1->GetReflection();
+  reflection->ListFields(*message2, &fields);
+  reflection->SwapFields(message1, message2.get(), fields);
+
+  TestUtil::ExpectAllFieldsSet(*message1);
+  TestUtil::ExpectClear(*message2);
+}
+
 TEST(GeneratedMessageReflectionTest, SwapFieldsAllExtension) {
   unittest::TestAllExtensions message1;
   unittest::TestAllExtensions message2;

src/google/protobuf/generated_message_util.cc

@@ -718,7 +718,8 @@ void GenericSwap(MessageLite* m1, MessageLite* m2) {
 MessageLite* GetOwnedMessageInternal(Arena* message_arena,
                                      MessageLite* submessage,
                                      Arena* submessage_arena) {
-  GOOGLE_DCHECK(submessage->GetArena() == submessage_arena);
+  GOOGLE_DCHECK(Arena::InternalHelper<MessageLite>::GetOwningArena(submessage) ==
+         submessage_arena);
   GOOGLE_DCHECK(message_arena != submessage_arena);
   if (message_arena != NULL && submessage_arena == NULL) {
     message_arena->Own(submessage);

src/google/protobuf/has_bits.h

@@ -47,17 +47,17 @@ namespace internal {
 template <size_t doublewords>
 class HasBits {
  public:
-  constexpr HasBits() PROTOBUF_NDEBUG_INLINE : has_bits_{} {}
+  PROTOBUF_NDEBUG_INLINE constexpr HasBits() : has_bits_{} {}
 
-  void Clear() PROTOBUF_NDEBUG_INLINE {
+  PROTOBUF_NDEBUG_INLINE void Clear() {
     memset(has_bits_, 0, sizeof(has_bits_));
   }
 
-  uint32& operator[](int index) PROTOBUF_NDEBUG_INLINE {
+  PROTOBUF_NDEBUG_INLINE uint32& operator[](int index) {
     return has_bits_[index];
   }
 
-  const uint32& operator[](int index) const PROTOBUF_NDEBUG_INLINE {
+  PROTOBUF_NDEBUG_INLINE const uint32& operator[](int index) const {
     return has_bits_[index];
   }
 

src/google/protobuf/io/coded_stream_unittest.cc

@@ -51,11 +51,6 @@
 
 #include <google/protobuf/port_def.inc>
 
-// This declares an unsigned long long integer literal in a portable way.
-// (The original macro is way too big and ruins my formatting.)
-#undef ULL
-#define ULL(x) PROTOBUF_ULONGLONG(x)
-
 
 namespace google {
 namespace protobuf {
@@ -168,24 +163,25 @@ VarintCase kVarintCases[] = {
     {{0xbe, 0xf7, 0x92, 0x84, 0x0b},
      5,  // 2961488830
      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
-         (ULL(0x0b) << 28)},
+         (uint64_t{0x0bu} << 28)},
 
     // 64-bit
     {{0xbe, 0xf7, 0x92, 0x84, 0x1b},
      5,  // 7256456126
      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
-         (ULL(0x1b) << 28)},
+         (uint64_t{0x1bu} << 28)},
     {{0x80, 0xe6, 0xeb, 0x9c, 0xc3, 0xc9, 0xa4, 0x49},
      8,  // 41256202580718336
      (0x00 << 0) | (0x66 << 7) | (0x6b << 14) | (0x1c << 21) |
-         (ULL(0x43) << 28) | (ULL(0x49) << 35) | (ULL(0x24) << 42) |
-         (ULL(0x49) << 49)},
+         (uint64_t{0x43u} << 28) | (uint64_t{0x49u} << 35) |
+         (uint64_t{0x24u} << 42) | (uint64_t{0x49u} << 49)},
     // 11964378330978735131
     {{0x9b, 0xa8, 0xf9, 0xc2, 0xbb, 0xd6, 0x80, 0x85, 0xa6, 0x01},
      10,
      (0x1b << 0) | (0x28 << 7) | (0x79 << 14) | (0x42 << 21) |
-         (ULL(0x3b) << 28) | (ULL(0x56) << 35) | (ULL(0x00) << 42) |
-         (ULL(0x05) << 49) | (ULL(0x26) << 56) | (ULL(0x01) << 63)},
+         (uint64_t{0x3bu} << 28) | (uint64_t{0x56u} << 35) |
+         (uint64_t{0x00u} << 42) | (uint64_t{0x05u} << 49) |
+         (uint64_t{0x26u} << 56) | (uint64_t{0x01u} << 63)},
 };
 
 TEST_2D(CodedStreamTest, ReadVarint32, kVarintCases, kBlockSizes) {
@@ -313,7 +309,7 @@ TEST_2D(CodedStreamTest, ReadVarint64, kVarintCases, kBlockSizes) {
 }
 
 TEST_2D(CodedStreamTest, WriteVarint32, kVarintCases, kBlockSizes) {
-  if (kVarintCases_case.value > ULL(0x00000000FFFFFFFF)) {
+  if (kVarintCases_case.value > uint64_t{0x00000000FFFFFFFFu}) {
     // Skip this test for the 64-bit values.
     return;
   }
@@ -500,8 +496,8 @@ VarintSizeCase kVarintSizeCases[] = {
     {128u, 2},
     {758923u, 3},
     {4000000000u, 5},
-    {ULL(41256202580718336), 8},
-    {ULL(11964378330978735131), 10},
+    {uint64_t{41256202580718336u}, 8},
+    {uint64_t{11964378330978735131u}, 10},
 };
 
 TEST_1D(CodedStreamTest, VarintSize32, kVarintSizeCases) {
@@ -569,8 +565,10 @@ Fixed32Case kFixed32Cases[] = {
 };
 
 Fixed64Case kFixed64Cases[] = {
-    {{0xef, 0xcd, 0xab, 0x90, 0x12, 0x34, 0x56, 0x78}, ULL(0x7856341290abcdef)},
-    {{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88}, ULL(0x8877665544332211)},
+    {{0xef, 0xcd, 0xab, 0x90, 0x12, 0x34, 0x56, 0x78},
+     uint64_t{0x7856341290abcdefu}},
+    {{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88},
+     uint64_t{0x8877665544332211u}},
 };
 
 TEST_2D(CodedStreamTest, ReadLittleEndian32, kFixed32Cases, kBlockSizes) {

src/google/protobuf/map_entry_lite.h

@@ -194,7 +194,7 @@ class MapEntryImpl : public Base {
         _has_bits_{} {}
 
   ~MapEntryImpl() {
-    if (Base::GetArena() != NULL) return;
+    if (Base::GetArenaForAllocation() != NULL) return;
     KeyTypeHandler::DeleteNoArena(key_);
     ValueTypeHandler::DeleteNoArena(value_);
   }
@@ -209,11 +209,12 @@ class MapEntryImpl : public Base {
   }
   inline KeyMapEntryAccessorType* mutable_key() {
     set_has_key();
-    return KeyTypeHandler::EnsureMutable(&key_, Base::GetArena());
+    return KeyTypeHandler::EnsureMutable(&key_, Base::GetArenaForAllocation());
   }
   inline ValueMapEntryAccessorType* mutable_value() {
     set_has_value();
-    return ValueTypeHandler::EnsureMutable(&value_, Base::GetArena());
+    return ValueTypeHandler::EnsureMutable(&value_,
+                                           Base::GetArenaForAllocation());
   }
 
   // implements MessageLite =========================================
@@ -301,13 +302,14 @@ class MapEntryImpl : public Base {
   void MergeFromInternal(const MapEntryImpl& from) {
     if (from._has_bits_[0]) {
       if (from.has_key()) {
-        KeyTypeHandler::EnsureMutable(&key_, Base::GetArena());
-        KeyTypeHandler::Merge(from.key(), &key_, Base::GetArena());
+        KeyTypeHandler::EnsureMutable(&key_, Base::GetArenaForAllocation());
+        KeyTypeHandler::Merge(from.key(), &key_, Base::GetArenaForAllocation());
         set_has_key();
       }
       if (from.has_value()) {
-        ValueTypeHandler::EnsureMutable(&value_, Base::GetArena());
-        ValueTypeHandler::Merge(from.value(), &value_, Base::GetArena());
+        ValueTypeHandler::EnsureMutable(&value_, Base::GetArenaForAllocation());
+        ValueTypeHandler::Merge(from.value(), &value_,
+                                Base::GetArenaForAllocation());
         set_has_value();
       }
     }
@@ -315,8 +317,8 @@ class MapEntryImpl : public Base {
 
  public:
   void Clear() override {
-    KeyTypeHandler::Clear(&key_, Base::GetArena());
-    ValueTypeHandler::Clear(&value_, Base::GetArena());
+    KeyTypeHandler::Clear(&key_, Base::GetArenaForAllocation());
+    ValueTypeHandler::Clear(&value_, Base::GetArenaForAllocation());
     clear_has_key();
     clear_has_value();
   }
@@ -328,7 +330,8 @@ class MapEntryImpl : public Base {
    public:
     explicit Parser(MapField* mf) : mf_(mf), map_(mf->MutableMap()) {}
     ~Parser() {
-      if (entry_ != nullptr && entry_->GetArena() == nullptr) delete entry_;
+      if (entry_ != nullptr && entry_->GetArenaForAllocation() == nullptr)
+        delete entry_;
     }
 
     // This does what the typical MergePartialFromCodedStream() is expected to

src/google/protobuf/map_field.cc

@@ -62,6 +62,7 @@ void MapFieldBase::Swap(MapFieldBase* other) {
 }
 
 void MapFieldBase::InternalSwap(MapFieldBase* other) {
+  std::swap(arena_, other->arena_);
   std::swap(repeated_field_, other->repeated_field_);
   // a relaxed swap of the atomic
   auto other_state = other->state_.load(std::memory_order_relaxed);
@@ -136,12 +137,8 @@ void MapFieldBase::SyncRepeatedFieldWithMap() const {
       // Double check state
       if (state_.load(std::memory_order_relaxed) == CLEAN) {
         if (repeated_field_ == nullptr) {
-          if (arena_ == nullptr) {
-            repeated_field_ = new RepeatedPtrField<Message>();
-          } else {
-            repeated_field_ =
-                Arena::CreateMessage<RepeatedPtrField<Message> >(arena_);
-          }
+          repeated_field_ =
+              Arena::CreateMessage<RepeatedPtrField<Message> >(arena_);
         }
         state_.store(CLEAN, std::memory_order_release);
       }
@@ -186,11 +183,11 @@ DynamicMapField::DynamicMapField(const Message* default_entry, Arena* arena)
       default_entry_(default_entry) {}
 
 DynamicMapField::~DynamicMapField() {
-  // DynamicMapField owns map values. Need to delete them before clearing
-  // the map.
-  for (Map<MapKey, MapValueRef>::iterator iter = map_.begin();
-       iter != map_.end(); ++iter) {
-    iter->second.DeleteData();
+  if (arena_ != nullptr) return;
+  // DynamicMapField owns map values. Need to delete them before clearing the
+  // map.
+  for (auto& kv : map_) {
+    kv.second.DeleteData();
   }
   map_.clear();
 }
@@ -402,13 +399,8 @@ void DynamicMapField::SyncRepeatedFieldWithMapNoLock() const {
   const FieldDescriptor* key_des = default_entry_->GetDescriptor()->map_key();
   const FieldDescriptor* val_des = default_entry_->GetDescriptor()->map_value();
   if (MapFieldBase::repeated_field_ == NULL) {
-    if (MapFieldBase::arena_ == NULL) {
-      MapFieldBase::repeated_field_ = new RepeatedPtrField<Message>();
-    } else {
-      MapFieldBase::repeated_field_ =
-          Arena::CreateMessage<RepeatedPtrField<Message> >(
-              MapFieldBase::arena_);
-    }
+    MapFieldBase::repeated_field_ =
+        Arena::CreateMessage<RepeatedPtrField<Message> >(MapFieldBase::arena_);
   }
 
   MapFieldBase::repeated_field_->Clear();

src/google/protobuf/map_field.h

@@ -336,13 +336,7 @@ class PROTOBUF_EXPORT MapFieldBase {
         mutex_(GOOGLE_PROTOBUF_LINKER_INITIALIZED),
         state_(STATE_MODIFIED_MAP) {}
   explicit MapFieldBase(Arena* arena)
-      : arena_(arena), repeated_field_(NULL), state_(STATE_MODIFIED_MAP) {
-    // Mutex's destructor needs to be called explicitly to release resources
-    // acquired in its constructor.
-    if (arena) {
-      arena->OwnDestructor(&mutex_);
-    }
-  }
+      : arena_(arena), repeated_field_(nullptr), state_(STATE_MODIFIED_MAP) {}
   virtual ~MapFieldBase();
 
   // Returns reference to internal repeated field. Data written using

src/google/protobuf/map_field_inl.h

@@ -297,13 +297,9 @@ template <typename Derived, typename Key, typename T,
 void MapField<Derived, Key, T, kKeyFieldType,
               kValueFieldType>::SyncRepeatedFieldWithMapNoLock() const {
   if (this->MapFieldBase::repeated_field_ == NULL) {
-    if (this->MapFieldBase::arena_ == NULL) {
-      this->MapFieldBase::repeated_field_ = new RepeatedPtrField<Message>();
-    } else {
-      this->MapFieldBase::repeated_field_ =
-          Arena::CreateMessage<RepeatedPtrField<Message> >(
-              this->MapFieldBase::arena_);
-    }
+    this->MapFieldBase::repeated_field_ =
+        Arena::CreateMessage<RepeatedPtrField<Message> >(
+            this->MapFieldBase::arena_);
   }
   const Map<Key, T>& map = impl_.GetMap();
   RepeatedPtrField<EntryType>* repeated_field =

src/google/protobuf/map_field_test.cc

@@ -100,6 +100,11 @@ class MapFieldBaseStub : public MapFieldBase {
   void CopyIterator(MapIterator* this_iterator,
                     const MapIterator& other_iterator) const override {}
   void IncreaseIterator(MapIterator* map_iter) const override {}
+
+  Arena* GetArenaForInternalRepeatedField() {
+    auto* repeated_field = MutableRepeatedField();
+    return repeated_field->GetArena();
+  }
 };
 
 class MapFieldBasePrimitiveTest : public testing::TestWithParam<bool> {
@@ -205,9 +210,17 @@ TEST_P(MapFieldBasePrimitiveTest, Arena) {
 
     // Trigger conversion to repeated field.
     EXPECT_TRUE(map_field->MutableRepeatedField() != NULL);
+
+    EXPECT_EQ(map_field->GetArenaForInternalRepeatedField(), &arena);
   }
 }
 
+TEST_P(MapFieldBasePrimitiveTest, EnforceNoArena) {
+  std::unique_ptr<MapFieldBaseStub> map_field(
+      Arena::CreateMessage<MapFieldBaseStub>(nullptr));
+  EXPECT_EQ(map_field->GetArenaForInternalRepeatedField(), nullptr);
+}
+
 namespace {
 enum State { CLEAN, MAP_DIRTY, REPEATED_DIRTY };
 }  // anonymous namespace

src/google/protobuf/map_test.cc

@@ -3754,6 +3754,22 @@ TEST(ArenaTest, DynamicMapFieldOnArena) {
   MapTestUtil::ExpectMapFieldsSet(message2);
 }
 
+TEST(ArenaTest, DynamicMapFieldOnArenaMemoryLeak) {
+  auto* desc = unittest::TestMap::descriptor();
+  auto* field = desc->FindFieldByName("map_int32_int32");
+
+  Arena arena;
+  DynamicMessageFactory factory;
+  auto* message = factory.GetPrototype(desc)->New(&arena);
+  auto* reflection = message->GetReflection();
+  reflection->AddMessage(message, field);
+
+  // Force internal syncing, which initializes the mutex.
+  MapReflectionTester reflection_tester(unittest::TestMap::descriptor());
+  int size = reflection_tester.MapSize(*message, "map_int32_int32");
+  EXPECT_EQ(size, 1);
+}
+
 TEST(MoveTest, MoveConstructorWorks) {
   Map<int32, TestAllTypes> original_map;
   original_map[42].mutable_optional_nested_message()->set_bb(42);

src/google/protobuf/message.cc

@@ -346,18 +346,8 @@ template <>
 PROTOBUF_NOINLINE
 #endif
     Arena*
-    GenericTypeHandler<Message>::GetArena(Message* value) {
-  return value->GetArena();
-}
-template <>
-#if defined(_MSC_VER) && (_MSC_VER >= 1800)
-// Note: force noinline to workaround MSVC compiler bug with /Zc:inline, issue
-// #240
-PROTOBUF_NOINLINE
-#endif
-    void*
-    GenericTypeHandler<Message>::GetMaybeArenaPointer(Message* value) {
-  return value->GetMaybeArenaPointer();
+    GenericTypeHandler<Message>::GetOwningArena(Message* value) {
+  return value->GetOwningArena();
 }
 }  // namespace internal
 

src/google/protobuf/message.h

@@ -951,6 +951,24 @@ class PROTOBUF_EXPORT Reflection final {
       const Message& message, bool should_fail,
       std::vector<const FieldDescriptor*>* output) const;
 
+  // Returns true if the message field is backed by a LazyField.
+  //
+  // A message field may be backed by a LazyField without the user annotation
+  // ([lazy = true]). While the user-annotated LazyField is lazily verified on
+  // first touch (i.e. failure on access rather than parsing if the LazyField is
+  // not initialized), the inferred LazyField is eagerly verified to avoid lazy
+  // parsing error at the cost of lower efficiency. When reflecting a message
+  // field, use this API instead of checking field->options().lazy().
+  bool IsLazyField(const FieldDescriptor* field) const {
+    return IsLazilyVerifiedLazyField(field) ||
+           IsEagerlyVerifiedLazyField(field);
+  }
+
+  bool IsLazilyVerifiedLazyField(const FieldDescriptor* field) const;
+  bool IsEagerlyVerifiedLazyField(const FieldDescriptor* field) const;
+
+  friend class FastReflectionMessageMutator;
+
   const Descriptor* const descriptor_;
   const internal::ReflectionSchema schema_;
   const DescriptorPool* const descriptor_pool_;
@@ -1067,7 +1085,6 @@ class PROTOBUF_EXPORT Reflection final {
   }
   const internal::ExtensionSet& GetExtensionSet(const Message& message) const;
   internal::ExtensionSet* MutableExtensionSet(Message* message) const;
-  inline Arena* GetArena(Message* message) const;
 
   inline const internal::InternalMetadata& GetInternalMetadata(
       const Message& message) const;

src/google/protobuf/message_lite.h

@@ -64,6 +64,10 @@ namespace protobuf {
 template <typename T>
 class RepeatedPtrField;
 
+class FastReflectionMessageMutator;
+class FastReflectionStringSetter;
+class Reflection;
+
 namespace io {
 
 class CodedInputStream;
@@ -83,10 +87,15 @@ struct ConstantInitialized {
 // See parse_context.h for explanation
 class ParseContext;
 
+class ExtensionSet;
+class LazyField;
 class RepeatedPtrFieldBase;
 class WireFormatLite;
 class WeakFieldMap;
 
+template <typename Type>
+class GenericTypeHandler;  // defined in repeated_field.h
+
 // We compute sizes as size_t but cache them as int.  This function converts a
 // computed size to a cached size.  Since we don't proceed with serialization
 // if the total size was > INT_MAX, it is not important what this function
@@ -209,12 +218,8 @@ class PROTOBUF_EXPORT MessageLite {
   // if arena is a NULL. Default implementation for backwards compatibility.
   virtual MessageLite* New(Arena* arena) const;
 
-  // Get the arena, if any, associated with this message. Virtual method
-  // required for generic operations but most arena-related operations should
-  // use the GetArena() generated-code method. Default implementation
-  // to reduce code size by avoiding the need for per-type implementations
-  // when types do not implement arena support.
-  Arena* GetArena() const { return _internal_metadata_.arena(); }
+  // Same as GetOwningArena.
+  Arena* GetArena() const { return GetOwningArena(); }
 
   // Get a pointer that may be equal to this message's arena, or may not be.
   // If the value returned by this method is equal to some arena pointer, then
@@ -469,6 +474,17 @@ class PROTOBUF_EXPORT MessageLite {
 
   inline explicit MessageLite(Arena* arena) : _internal_metadata_(arena) {}
 
+  // Returns the arena, if any, that directly owns this message and its internal
+  // memory (Arena::Own is different in that the arena doesn't directly own the
+  // internal memory). This method is used in proto's implementation for
+  // swapping, moving and setting allocated, for deciding whether the ownership
+  // of this message or its internal memory could be changed.
+  Arena* GetOwningArena() const { return _internal_metadata_.arena(); }
+
+  // Returns the arena, used for allocating internal objects(e.g., child
+  // messages, etc), or owning incoming objects (e.g., set allocated).
+  Arena* GetArenaForAllocation() const { return _internal_metadata_.arena(); }
+
   internal::InternalMetadata _internal_metadata_;
 
  public:
@@ -502,9 +518,19 @@ class PROTOBUF_EXPORT MessageLite {
   // TODO(gerbens) make this a pure abstract function
   virtual const void* InternalGetTable() const { return NULL; }
 
-  friend class internal::WireFormatLite;
+  friend class FastReflectionMessageMutator;
+  friend class FastReflectionStringSetter;
   friend class Message;
+  friend class Reflection;
+  friend class internal::ExtensionSet;
+  friend class internal::LazyField;
   friend class internal::WeakFieldMap;
+  friend class internal::WireFormatLite;
+
+  template <typename Type>
+  friend class Arena::InternalHelper;
+  template <typename Type>
+  friend class internal::GenericTypeHandler;
 
   void LogInitializationErrorMessage() const;
 

src/google/protobuf/message_unittest.inc

@@ -548,8 +548,9 @@ TEST(MESSAGE_TEST_NAME, ReleaseMustUseResult) {
   message.set_allocated_optional_foreign_message(f);
   auto* mf = message.mutable_optional_foreign_message();
   EXPECT_EQ(mf, f);
-  EXPECT_NE(message.release_optional_foreign_message(), nullptr);
-  delete f;
+  std::unique_ptr<UNITTEST::ForeignMessage> rf(
+      message.release_optional_foreign_message());
+  EXPECT_NE(rf.get(), nullptr);
 }
 
 TEST(MESSAGE_TEST_NAME, ParseFailsOnInvalidMessageEnd) {

src/google/protobuf/port_def.inc

@@ -48,129 +48,85 @@
 // detect/prohibit anytime it is #included twice without a corresponding
 // #undef.
 
-// These macros are private and should always be #undef'd from headers.
-// If any of these errors fire, you should either properly #include
-// port_undef.h at the end of your header that #includes port.h, or
-// don't #include port.h twice in a .cc file.
-#ifdef PROTOBUF_NAMESPACE
-#error PROTOBUF_NAMESPACE was previously defined
-#endif
-#ifdef PROTOBUF_NAMESPACE_ID
-#error PROTOBUF_NAMESPACE_ID was previously defined
-#endif
-#ifdef PROTOBUF_ALWAYS_INLINE
-#error PROTOBUF_ALWAYS_INLINE was previously defined
-#endif
-#ifdef PROTOBUF_NDEBUG_INLINE
-#error PROTOBUF_NDEBUG_INLINE was previously defined
-#endif
-#ifdef PROTOBUF_COLD
-#error PROTOBUF_COLD was previously defined
-#endif
-#ifdef PROTOBUF_NOINLINE
-#error PROTOBUF_NOINLINE was previously defined
-#endif
-#ifdef PROTOBUF_SECTION_VARIABLE
-#error PROTOBUF_SECTION_VARIABLE was previously defined
-#endif
-#ifdef PROTOBUF_DEPRECATED
-#error PROTOBUF_DEPRECATED was previously defined
+// The definitions in this file are intended to be portable across Clang,
+// GCC, and MSVC. Function-like macros are usable without an #ifdef guard.
+// Syntax macros (for example, attributes) are always defined, although
+// they may be empty.
+
+// Portable fallbacks for C++20 feature test macros:
+// https://en.cppreference.com/w/cpp/feature_test
+#ifndef __has_cpp_attribute
+#define __has_cpp_attribute(x) 0
+#define PROTOBUF_has_cpp_attribute_DEFINED_
 #endif
-#ifdef PROTOBUF_DEPRECATED_MSG
-#error PROTOBUF_DEPRECATED_MSG was previously defined
+
+// Portable fallback for Clang's __has_feature macro:
+// https://clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension
+#ifndef __has_feature
+#define __has_feature(x) 0
+#define PROTOBUF_has_feature_DEFINED_
 #endif
-#ifdef PROTOBUF_FUNC_ALIGN
-#error PROTOBUF_FUNC_ALIGN was previously defined
+
+// Portable fallback for Clang's __has_warning macro:
+#ifndef __has_warning
+#define __has_warning(x) 0
+#define PROTOBUF_has_warning_DEFINED_
 #endif
-#ifdef PROTOBUF_RETURNS_NONNULL
-#error PROTOBUF_RETURNS_NONNULL was previously defined
+
+// Portable fallbacks for the __has_attribute macro (GCC and Clang):
+// https://clang.llvm.org/docs/LanguageExtensions.html#has-attribute
+// https://gcc.gnu.org/onlinedocs/cpp/_005f_005fhas_005fattribute.html
+#ifndef __has_attribute
+#define __has_attribute(x) 0
+#define PROTOBUF_has_attribute_DEFINED_
 #endif
-#ifdef PROTOBUF_ATTRIBUTE_REINITIALIZES
-#error PROTOBUF_ATTRIBUTE_REINITIALIZES was previously defined
+
+// Portable fallback for __has_builtin (GCC and Clang):
+// https://clang.llvm.org/docs/LanguageExtensions.html#has-builtin
+// https://gcc.gnu.org/onlinedocs/cpp/_005f_005fhas_005fbuiltin.html
+#ifndef __has_builtin
+#define __has_builtin(x) 0
+#define PROTOBUF_has_builtin_DEFINED_
 #endif
-#ifdef PROTOBUF_RTTI
-#error PROTOBUF_RTTI was previously defined
+
+// Portable check for GCC minimum version:
+// https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) \
+    && defined(__GNUC_PATCHLEVEL__)
+#  define PROTOBUF_GNUC_MIN(x, y) \
+  (__GNUC__ > (x) || __GNUC__ == (x) && __GNUC_MINOR__ >= (y))
+#else
+#  define PROTOBUF_GNUC_MIN(x, y) 0
 #endif
+
+// Future versions of protobuf will include breaking changes to some APIs.
+// This macro can be set to enable these API changes ahead of time, so that
+// user code can be updated before upgrading versions of protobuf.
+// #define PROTOBUF_FUTURE_BREAKING_CHANGES 1
+
 #ifdef PROTOBUF_VERSION
 #error PROTOBUF_VERSION was previously defined
 #endif
-#ifdef PROTOBUF_VERSION_SUFFIX
-#error PROTOBUF_VERSION_SUFFIX was previously defined
-#endif
+#define PROTOBUF_VERSION 3015008
+
 #ifdef PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC
 #error PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC was previously defined
 #endif
+#define PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC 3015000
+
 #ifdef PROTOBUF_MIN_PROTOC_VERSION
 #error PROTOBUF_MIN_PROTOC_VERSION was previously defined
 #endif
-#ifdef PROTOBUF_PREDICT_TRUE
-#error PROTOBUF_PREDICT_TRUE was previously defined
-#endif
-#ifdef PROTOBUF_PREDICT_FALSE
-#error PROTOBUF_PREDICT_FALSE was previously defined
-#endif
-#ifdef PROTOBUF_FIELD_OFFSET
-#error PROTOBUF_FIELD_OFFSET was previously defined
-#endif
-#ifdef PROTOBUF_LL_FORMAT
-#error PROTOBUF_LL_FORMAT was previously defined
-#endif
-#ifdef PROTOBUF_GUARDED_BY
-#error PROTOBUF_GUARDED_BY was previously defined
-#endif
-#ifdef PROTOBUF_LONGLONG
-#error PROTOBUF_LONGLONG was previously defined
-#endif
-#ifdef PROTOBUF_ULONGLONG
-#error PROTOBUF_ULONGLONG was previously defined
-#endif
-#ifdef PROTOBUF_FALLTHROUGH_INTENDED
-#error PROTOBUF_FALLTHROUGH_INTENDED was previously defined
-#endif
-#ifdef PROTOBUF_EXPORT
-#error PROTOBUF_EXPORT was previously defined
-#endif
-#ifdef PROTOC_EXPORT
-#error PROTOC_EXPORT was previously defined
-#endif
-#ifdef PROTOBUF_MUST_USE_RESULT
-#error PROTOBUF_MUST_USE_RESULT was previously defined
-#endif
-#ifdef PROTOBUF_UNUSED
-#error PROTOBUF_UNUSED was previously defined
-#endif
-#ifdef PROTOBUF_FINAL
-#error PROTOBUF_FINAL was previously defined
-#endif
-#ifdef PROTOBUF_ENABLE_MSVC_UNION_WARNING
-#error PROTOBUF_ENABLE_MSVC_UNION_WARNING was previously defined
-#endif
-#ifdef PROTOBUF_CONSTINIT
-#error PROTOBUF_CONSTINIT was previously defined
-#endif
-#ifdef PROTOBUF_ATTRIBUTE_NO_DESTROY
-#error PROTOBUF_ATTRIBUTE_NO_DESTROY was previously defined
-#endif
-#ifdef PROTOBUF_ATTRIBUTE_INIT_PRIORITY
-#error PROTOBUF_ATTRIBUTE_INIT_PRIORITY was previously defined
-#endif
-#ifdef PROTOBUF_PRAGMA_INIT_SEG
-#error PROTOBUF_PRAGMA_INIT_SEG was previously defined
-#endif
-#ifdef PROTOBUF_ATTRIBUTE_WEAK
-#error PROTOBUF_ATTRIBUTE_WEAK was previously defined
-#endif
-#ifdef PROTOBUF_ASAN
-#error PROTOBUF_ASAN was previously defined
-#endif
-#ifdef PROTOBUF_MSAN
-#error PROTOBUF_MSAN was previously defined
-#endif
-#ifdef PROTOBUF_TSAN
-#error PROTOBUF_TSAN was previously defined
-#endif
+#define PROTOBUF_MIN_PROTOC_VERSION 3015000
 
+#ifdef PROTOBUF_VERSION_SUFFIX
+#error PROTOBUF_VERSION_SUFFIX was previously defined
+#endif
+#define PROTOBUF_VERSION_SUFFIX ""
 
+#if defined(PROTOBUF_NAMESPACE) || defined(PROTOBUF_NAMESPACE_ID)
+#error PROTOBUF_NAMESPACE or PROTOBUF_NAMESPACE_ID was previously defined
+#endif
 #define PROTOBUF_NAMESPACE "google::protobuf"
 #define PROTOBUF_NAMESPACE_ID google::protobuf
 #define PROTOBUF_NAMESPACE_OPEN \
@@ -180,193 +136,170 @@
   } /* namespace protobuf */     \
   } /* namespace google */
 
-#if defined(__clang__)
-#define PROTOBUF_DEPRECATED __attribute__((deprecated))
-#define PROTOBUF_DEPRECATED_ENUM __attribute__((deprecated))
-#define PROTOBUF_DEPRECATED_MSG(msg) __attribute__((deprecated(msg)))
-#elif defined(__GNUC__)
-#define PROTOBUF_DEPRECATED __attribute__((deprecated))
-#define PROTOBUF_DEPRECATED_MSG(msg) __attribute__((deprecated(msg)))
-#if __GNUC__ >= 6
-#define PROTOBUF_DEPRECATED_ENUM __attribute__((deprecated))
-#else
-#define PROTOBUF_DEPRECATED_ENUM
+#ifdef PROTOBUF_ALWAYS_INLINE
+#error PROTOBUF_ALWAYS_INLINE was previously defined
 #endif
+// For functions we want to force inline.
+#if defined(PROTOBUF_NO_INLINE)
+# define PROTOBUF_ALWAYS_INLINE
+#elif PROTOBUF_GNUC_MIN(3, 1)
+# define PROTOBUF_ALWAYS_INLINE __attribute__((always_inline))
 #elif defined(_MSC_VER)
-#define PROTOBUF_DEPRECATED __declspec(deprecated)
-#define PROTOBUF_DEPRECATED_ENUM
-#define PROTOBUF_DEPRECATED_MSG(msg) __declspec(deprecated(msg))
+# define PROTOBUF_ALWAYS_INLINE __forceinline
+#else
+# define PROTOBUF_ALWAYS_INLINE
 #endif
 
-#define PROTOBUF_SECTION_VARIABLE(x)
-#define PROTOBUF_MUST_USE_RESULT
-#define PROTOBUF_FUTURE_MUST_USE_RESULT
-
-// ----------------------------------------------------------------------------
-// Annotations:  Some parts of the code have been annotated in ways that might
-//   be useful to some compilers or tools, but are not supported universally.
-//   You can #define these annotations yourself if the default implementation
-//   is not right for you.
-
-#ifndef PROTOBUF_NO_INLINE
-#ifdef GOOGLE_ATTRIBUTE_ALWAYS_INLINE
-#define PROTOBUF_ALWAYS_INLINE GOOGLE_ATTRIBUTE_ALWAYS_INLINE
-#define PROTOBUF_NDEBUG_INLINE GOOGLE_ATTRIBUTE_ALWAYS_INLINE
-#elif defined(__GNUC__) && \
-    (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
-// For functions we want to force inline.
-// Introduced in gcc 3.1.
-#define PROTOBUF_ALWAYS_INLINE __attribute__((always_inline))
-#define PROTOBUF_NDEBUG_INLINE __attribute__((always_inline))
+#ifdef PROTOBUF_NDEBUG_INLINE
+#error PROTOBUF_NDEBUG_INLINE was previously defined
 #endif
+// Avoid excessive inlining in non-optimized builds. Without other optimizations
+// the inlining is not going to provide benefits anyway and the huge resulting
+// functions, especially in the proto-generated serialization functions, produce
+// stack frames so large that many tests run into stack overflows (b/32192897).
+#if defined(NDEBUG) || (defined(_MSC_VER) && !defined(_DEBUG))
+# define PROTOBUF_NDEBUG_INLINE PROTOBUF_ALWAYS_INLINE
+#else
+# define PROTOBUF_NDEBUG_INLINE
 #endif
 
-#ifndef PROTOBUF_ALWAYS_INLINE
-// Other compilers will have to figure it out for themselves.
-#define PROTOBUF_ALWAYS_INLINE
-#define PROTOBUF_NDEBUG_INLINE
+// Note that PROTOBUF_NOINLINE is an attribute applied to functions, to prevent
+// them from being inlined by the compiler. This is different from
+// PROTOBUF_NO_INLINE, which is a user-supplied macro that disables forced
+// inlining by PROTOBUF_(ALWAYS|NDEBUG)_INLINE.
+#ifdef PROTOBUF_NOINLINE
+#error PROTOBUF_NOINLINE was previously defined
 #endif
-
-#ifdef GOOGLE_ATTRIBUTE_NOINLINE
-#define PROTOBUF_NOINLINE GOOGLE_ATTRIBUTE_NOINLINE
-#else
-#if defined(__GNUC__) && \
-    (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
-// For functions we want to force not inline.
-// Introduced in gcc 3.1.
-#define PROTOBUF_NOINLINE __attribute__((noinline))
-#elif defined(_MSC_VER) && (_MSC_VER >= 1400)
+#if PROTOBUF_GNUC_MIN(3, 1)
+# define PROTOBUF_NOINLINE __attribute__((noinline))
+#elif defined(_MSC_VER)
 // Seems to have been around since at least Visual Studio 2005
-#define PROTOBUF_NOINLINE __declspec(noinline)
-#else
-// Other compilers will have to figure it out for themselves.
-#define PROTOBUF_NOINLINE
-#endif
+# define PROTOBUF_NOINLINE __declspec(noinline)
 #endif
 
-#ifdef GOOGLE_ATTRIBUTE_FUNC_ALIGN
-#define PROTOBUF_FUNC_ALIGN GOOGLE_ATTRIBUTE_FUNC_ALIGN
-#else
-#if defined(__clang__) || \
-    defined(__GNUC__) &&  \
-        (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
-// Function alignment attribute introduced in gcc 4.3
-#define PROTOBUF_FUNC_ALIGN(bytes) __attribute__((aligned(bytes)))
-#else
-#define PROTOBUF_FUNC_ALIGN(bytes)
+#ifdef PROTOBUF_EXCLUSIVE_LOCKS_REQUIRED
+#error PROTOBUF_EXCLUSIVE_LOCKS_REQUIRED was previously defined
 #endif
+#if __has_attribute(exclusive_locks_required)
+#define PROTOBUF_EXCLUSIVE_LOCKS_REQUIRED(...) \
+  __attribute__((exclusive_locks_required(__VA_ARGS__)))
+#else
+#define PROTOBUF_EXCLUSIVE_LOCKS_REQUIRED(...)
 #endif
 
-#ifdef GOOGLE_PREDICT_TRUE
-#define PROTOBUF_PREDICT_TRUE GOOGLE_PREDICT_TRUE
-#else
-#ifdef __GNUC__
-// Provided at least since GCC 3.0.
-#define PROTOBUF_PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
-#else
-#define PROTOBUF_PREDICT_TRUE(x) (x)
+#ifdef PROTOBUF_NO_THREAD_SAFETY_ANALYSIS
+#error PROTOBUF_NO_THREAD_SAFETY_ANALYSIS was previously defined
 #endif
+#if __has_attribute(no_thread_safety_analysis)
+#define PROTOBUF_NO_THREAD_SAFETY_ANALYSIS \
+  __attribute__((no_thread_safety_analysis))
+#else
+#define PROTOBUF_NO_THREAD_SAFETY_ANALYSIS
 #endif
 
-#ifdef GOOGLE_PREDICT_FALSE
-#define PROTOBUF_PREDICT_FALSE GOOGLE_PREDICT_FALSE
-#else
-#ifdef __GNUC__
-// Provided at least since GCC 3.0.
-#define PROTOBUF_PREDICT_FALSE(x) (__builtin_expect(x, 0))
-#else
-#define PROTOBUF_PREDICT_FALSE(x) (x)
+#ifdef PROTOBUF_GUARDED_BY
+#error PROTOBUF_GUARDED_BY was previously defined
 #endif
+#if __has_attribute(guarded_by)
+#define PROTOBUF_GUARDED_BY(x) __attribute__((guarded_by(x)))
+#else
+#define PROTOBUF_GUARDED_BY(x)
 #endif
 
-#ifdef GOOGLE_PROTOBUF_ATTRIBUTE_RETURNS_NONNULL
-#define PROTOBUF_RETURNS_NONNULL GOOGLE_PROTOBUF_ATTRIBUTE_RETURNS_NONNULL
+#ifdef PROTOBUF_LOCKS_EXCLUDED
+#error PROTOBUF_LOCKS_EXCLUDED was previously defined
+#endif
+#if __has_attribute(locks_excluded)
+#define PROTOBUF_LOCKS_EXCLUDED(...) \
+  __attribute__((locks_excluded(__VA_ARGS__)))
 #else
-#if defined(__has_attribute)
-#if __has_attribute(returns_nonnull)
-#define PROTOBUF_RETURNS_NONNULL __attribute__((returns_nonnull))
+#define PROTOBUF_LOCKS_EXCLUDED(...)
 #endif
+
+#ifdef PROTOBUF_COLD
+#error PROTOBUF_COLD was previously defined
 #endif
+#if __has_attribute(cold) || PROTOBUF_GNUC_MIN(4, 3)
+# define PROTOBUF_COLD __attribute__((cold))
+#else
+# define PROTOBUF_COLD
 #endif
-#ifndef PROTOBUF_RETURNS_NONNULL
-#define PROTOBUF_RETURNS_NONNULL
+
+#ifdef PROTOBUF_SECTION_VARIABLE
+#error PROTOBUF_SECTION_VARIABLE was previously defined
 #endif
+#define PROTOBUF_SECTION_VARIABLE(x)
 
-#if defined(__has_cpp_attribute)
-#if __has_cpp_attribute(clang::reinitializes)
-#define PROTOBUF_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
+#if defined(PROTOBUF_DEPRECATED)
+#error PROTOBUF_DEPRECATED was previously defined
 #endif
+#if defined(PROTOBUF_DEPRECATED_MSG)
+#error PROTOBUF_DEPRECATED_MSG was previously defined
 #endif
-#ifndef PROTOBUF_ATTRIBUTE_REINITIALIZES
-#define PROTOBUF_ATTRIBUTE_REINITIALIZES
+#if __has_attribute(deprecated) || PROTOBUF_GNUC_MIN(3, 0)
+# define PROTOBUF_DEPRECATED __attribute__((deprecated))
+# define PROTOBUF_DEPRECATED_MSG(msg) __attribute__((deprecated(msg)))
+#elif defined(_MSC_VER)
+# define PROTOBUF_DEPRECATED __declspec(deprecated)
+# define PROTOBUF_DEPRECATED_MSG(msg) __declspec(deprecated(msg))
+#else
+# define PROTOBUF_DEPRECATED
+# define PROTOBUF_DEPRECATED_MSG(msg)
 #endif
 
-#define PROTOBUF_GUARDED_BY(x)
-#define PROTOBUF_COLD
-
-// Copied from ABSL.
-#if defined(__clang__) && defined(__has_warning)
-#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
-#define PROTOBUF_FALLTHROUGH_INTENDED [[clang::fallthrough]]
+#if defined(PROTOBUF_DEPRECATED_ENUM)
+#error PROTOBUF_DEPRECATED_ENUM was previously defined
 #endif
-#elif defined(__GNUC__) && __GNUC__ >= 7
-#define PROTOBUF_FALLTHROUGH_INTENDED [[gnu::fallthrough]]
+#if defined(__clang__) || PROTOBUF_GNUC_MIN(6, 0)
+// https://gcc.gnu.org/gcc-6/changes.html
+# define PROTOBUF_DEPRECATED_ENUM __attribute__((deprecated))
+#else
+# define PROTOBUF_DEPRECATED_ENUM
 #endif
 
-#ifndef PROTOBUF_FALLTHROUGH_INTENDED
-#define PROTOBUF_FALLTHROUGH_INTENDED
+#ifdef PROTOBUF_FUNC_ALIGN
+#error PROTOBUF_FUNC_ALIGN was previously defined
 #endif
-
-#if defined(__has_cpp_attribute)
-#define HAS_ATTRIBUTE(attr) __has_cpp_attribute(attr)
+#if __has_attribute(aligned) || PROTOBUF_GNUC_MIN(4, 3)
+#define PROTOBUF_FUNC_ALIGN(bytes) __attribute__((aligned(bytes)))
 #else
-#define HAS_ATTRIBUTE(attr) 0
+#define PROTOBUF_FUNC_ALIGN(bytes)
 #endif
 
-#if HAS_ATTRIBUTE(unused) || (defined(__GNUC__) && !defined(__clang__))
-#define PROTOBUF_UNUSED __attribute__((__unused__))
+#ifdef PROTOBUF_RETURNS_NONNULL
+#error PROTOBUF_RETURNS_NONNULL was previously defined
+#endif
+#if __has_attribute(returns_nonnull) || PROTOBUF_GNUC_MIN(4, 9)
+#define PROTOBUF_RETURNS_NONNULL __attribute__((returns_nonnull))
 #else
-#define PROTOBUF_UNUSED
+#define PROTOBUF_RETURNS_NONNULL
 #endif
 
-#undef HAS_ATTRIBUTE
-
-#ifdef _MSC_VER
-#define PROTOBUF_LONGLONG(x) x##I64
-#define PROTOBUF_ULONGLONG(x) x##UI64
-#define PROTOBUF_LL_FORMAT "I64"  // As in printf("%I64d", ...)
+#ifdef PROTOBUF_ATTRIBUTE_REINITIALIZES
+#error PROTOBUF_ATTRIBUTE_REINITIALIZES was previously defined
+#endif
+#if __has_cpp_attribute(clang::reinitializes)
+#define PROTOBUF_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
 #else
-// By long long, we actually mean int64.
-#define PROTOBUF_LONGLONG(x) x##LL
-#define PROTOBUF_ULONGLONG(x) x##ULL
-// Used to format real long long integers.
-#define PROTOBUF_LL_FORMAT \
-  "ll"  // As in "%lld". Note that "q" is poor form also.
+#define PROTOBUF_ATTRIBUTE_REINITIALIZES
 #endif
 
-
-#define PROTOBUF_VERSION 3015008
-#define PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC 3015000
-#define PROTOBUF_MIN_PROTOC_VERSION 3015000
-#define PROTOBUF_VERSION_SUFFIX ""
-
 // The minimum library version which works with the current version of the
 // headers.
 #define GOOGLE_PROTOBUF_MIN_LIBRARY_VERSION 3015000
 
+#ifdef PROTOBUF_RTTI
+#error PROTOBUF_RTTI was previously defined
+#endif
 #if defined(GOOGLE_PROTOBUF_NO_RTTI) && GOOGLE_PROTOBUF_NO_RTTI
 #define PROTOBUF_RTTI 0
-#elif defined(__has_feature)
-// https://clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension
-#define PROTOBUF_RTTI __has_feature(cxx_rtti)
-#elif !defined(__cxx_rtti)
+#elif __has_feature(cxx_rtti)
+#define PROTOBUF_RTTI 1
+#elif defined(__cxx_rtti)
 // https://en.cppreference.com/w/User:D41D8CD98F/feature_testing_macros#C.2B.2B98
-#define PROTOBUF_RTTI 0
-#elif defined(__GNUC__) && !defined(__GXX_RTTI)
-#https:  // gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
-#define PROTOBUF_RTTI 0
-#else
 #define PROTOBUF_RTTI 1
+#else
+#define PROTOBUF_RTTI 0
 #endif
 
 // Returns the offset of the given field within the given aggregate type.
@@ -377,6 +310,9 @@
 // which the offsets of the direct fields of a class are non-constant.
 // Fields inherited from superclasses *can* have non-constant offsets,
 // but that's not what this macro will be used for.
+#ifdef PROTOBUF_FIELD_OFFSET
+#error PROTOBUF_FIELD_OFFSET was previously defined
+#endif
 #if defined(__clang__)
 // For Clang we use __builtin_offsetof() and suppress the warning,
 // to avoid Control Flow Integrity and UBSan vptr sanitizers from
@@ -386,8 +322,7 @@
   _Pragma("clang diagnostic ignored \"-Winvalid-offsetof\"") \
   __builtin_offsetof(TYPE, FIELD)                            \
   _Pragma("clang diagnostic pop")
-#elif defined(__GNUC__) && \
-          (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))
+#elif PROTOBUF_GNUC_MIN(4, 8)
 #define PROTOBUF_FIELD_OFFSET(TYPE, FIELD) __builtin_offsetof(TYPE, FIELD)
 #else  // defined(__clang__)
 // Note that we calculate relative to the pointer value 16 here since if we
@@ -400,121 +335,81 @@
                          reinterpret_cast<const char*>(16))
 #endif
 
-#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)
+#ifdef PROTOBUF_EXPORT
+#error PROTOBUF_EXPORT was previously defined
 #endif
-#ifdef LIBPROTOC_EXPORTS
-#define PROTOC_EXPORT __declspec(dllexport)
+
+#if defined(PROTOBUF_USE_DLLS) && defined(_MSC_VER)
+# if defined(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  // defined(LIBPROTOBUF_EXPORTS)
+#elif defined(PROTOBUF_USE_DLLS) && defined(LIBPROTOBUF_EXPORTS)
+# define PROTOBUF_EXPORT __attribute__((visibility("default")))
+# define PROTOBUF_EXPORT_TEMPLATE_DECLARE __attribute__((visibility("default")))
+# define PROTOBUF_EXPORT_TEMPLATE_DEFINE
 #else
-#define PROTOC_EXPORT __declspec(dllimport)
+# define PROTOBUF_EXPORT
+# define PROTOBUF_EXPORT_TEMPLATE_DECLARE
+# define PROTOBUF_EXPORT_TEMPLATE_DEFINE
 #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
+
+#ifdef PROTOC_EXPORT
+#error PROTOC_EXPORT was previously defined
 #endif
-#ifdef LIBPROTOC_EXPORTS
-#define PROTOC_EXPORT __attribute__((visibility("default")))
+
+#if defined(PROTOBUF_USE_DLLS) && defined(_MSC_VER)
+# if defined(LIBPROTOC_EXPORTS)
+#  define PROTOC_EXPORT __declspec(dllexport)
+# else
+#  define PROTOC_EXPORT __declspec(dllimport)
+# endif  // defined(LIBPROTOC_EXPORTS)
+#elif defined(PROTOBUF_USE_DLLS) && defined(LIBPROTOBUF_EXPORTS)
+# define PROTOC_EXPORT __attribute__((visibility("default")))
 #else
-#define PROTOC_EXPORT
+# define PROTOC_EXPORT
 #endif
+
+#if defined(PROTOBUF_PREDICT_TRUE) || defined(PROTOBUF_PREDICT_FALSE)
+#error PROTOBUF_PREDICT_(TRUE|FALSE) was previously defined
 #endif
-#else  // defined(PROTOBUF_USE_DLLS)
-#define PROTOBUF_EXPORT
-#define PROTOC_EXPORT
-#define PROTOBUF_EXPORT_TEMPLATE_DECLARE
-#define PROTOBUF_EXPORT_TEMPLATE_DEFINE
+#if PROTOBUF_GNUC_MIN(3, 0)
+# define PROTOBUF_PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
+# define PROTOBUF_PREDICT_FALSE(x) (__builtin_expect((x), 0))
+#else
+# define PROTOBUF_PREDICT_TRUE(x) (x)
+# define PROTOBUF_PREDICT_FALSE(x) (x)
 #endif
 
-// Windows declares several inconvenient macro names.  We #undef them and then
-// restore them in port_undef.inc.
-#ifdef _MSC_VER
-#pragma push_macro("CREATE_NEW")
-#undef CREATE_NEW
-#pragma push_macro("DELETE")
-#undef DELETE
-#pragma push_macro("DOUBLE_CLICK")
-#undef DOUBLE_CLICK
-#pragma push_macro("ERROR")
-#undef ERROR
-#pragma push_macro("ERROR_BUSY")
-#undef ERROR_BUSY
-#pragma push_macro("ERROR_INSTALL_FAILED")
-#undef ERROR_INSTALL_FAILED
-#pragma push_macro("ERROR_NOT_FOUND")
-#undef ERROR_NOT_FOUND
-#pragma push_macro("GetMessage")
-#undef GetMessage
-#pragma push_macro("IGNORE")
-#undef IGNORE
-#pragma push_macro("IN")
-#undef IN
-#pragma push_macro("INPUT_KEYBOARD")
-#undef INPUT_KEYBOARD
-#pragma push_macro("NO_ERROR")
-#undef NO_ERROR
-#pragma push_macro("OUT")
-#undef OUT
-#pragma push_macro("OPTIONAL")
-#undef OPTIONAL
-#pragma push_macro("min")
-#undef min
-#pragma push_macro("max")
-#undef max
-#pragma push_macro("NEAR")
-#undef NEAR
-#pragma push_macro("NO_DATA")
-#undef NO_DATA
-#pragma push_macro("REASON_UNKNOWN")
-#undef REASON_UNKNOWN
-#pragma push_macro("SERVICE_DISABLED")
-#undef SERVICE_DISABLED
-#pragma push_macro("SEVERITY_ERROR")
-#undef SEVERITY_ERROR
-#pragma push_macro("STRICT")
-#undef STRICT
-#pragma push_macro("timezone")
-#undef timezone
-#endif  // _MSC_VER
-
-#if defined(__clang__) || defined(__GNUC__) || defined(_MSC_VER)
-// Don't let Objective-C Macros interfere with proto identifiers with the same
-// name.
-#pragma push_macro("DEBUG")
-#undef DEBUG
-#endif // defined(__clang__) || defined(__GNUC__) || defined(_MSC_VER)
+#ifdef PROTOBUF_MUST_USE_RESULT
+#error PROTOBUF_MUST_USE_RESULT was previously defined
+#endif
+# define PROTOBUF_FUTURE_MUST_USE_RESULT
+# define PROTOBUF_MUST_USE_RESULT
 
-#if defined(__clang__)
-#pragma clang diagnostic push
-// TODO(gerbens) ideally we cleanup the code. But a cursory try shows many
-// violations. So let's ignore for now.
-#pragma clang diagnostic ignored "-Wshorten-64-to-32"
-#elif defined(__GNUC__)
-// GCC does not allow disabling diagnostics within an expression:
-// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875, so we disable this one
-// globally even though it's only used for PROTOBUF_FIELD_OFFSET.
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+#ifdef PROTOBUF_FALLTHROUGH_INTENDED
+#error PROTOBUF_FALLTHROUGH_INTENDED was previously defined
+#endif
+#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
+#define PROTOBUF_FALLTHROUGH_INTENDED [[clang::fallthrough]]
+#elif PROTOBUF_GNUC_MIN(7, 0)
+#define PROTOBUF_FALLTHROUGH_INTENDED [[gnu::fallthrough]]
+#else
+#define PROTOBUF_FALLTHROUGH_INTENDED
 #endif
 
 // PROTOBUF_ASSUME(pred) tells the compiler that it can assume pred is true. To
 // be safe, we also validate the assumption with a GOOGLE_DCHECK in unoptimized
 // builds. The macro does not do anything useful if the compiler does not
 // support __builtin_assume.
-#ifdef __has_builtin
+#ifdef PROTOBUF_ASSUME
+#error PROTOBUF_ASSUME was previously defined
+#endif
 #if __has_builtin(__builtin_assume)
 #define PROTOBUF_ASSUME(pred) \
   GOOGLE_DCHECK(pred);               \
@@ -522,9 +417,6 @@
 #else
 #define PROTOBUF_ASSUME(pred) GOOGLE_DCHECK(pred)
 #endif
-#else
-#define PROTOBUF_ASSUME(pred) GOOGLE_DCHECK(pred)
-#endif
 
 // Specify memory alignment for structs, classes, etc.
 // Use like:
@@ -547,17 +439,21 @@
 // definition: visibility (used for exporting functions/classes) is one of
 // these attributes. This means that it is not possible to use alignas() with a
 // class that is marked as exported.
+#ifdef PROTOBUF_ALIGNAS
+#error PROTOBUF_ALIGNAS was previously defined
+#endif
 #if defined(_MSC_VER)
 #define PROTOBUF_ALIGNAS(byte_alignment) __declspec(align(byte_alignment))
-#elif defined(__GNUC__)
+#elif PROTOBUF_GNUC_MIN(3, 0)
 #define PROTOBUF_ALIGNAS(byte_alignment) \
   __attribute__((aligned(byte_alignment)))
 #else
 #define PROTOBUF_ALIGNAS(byte_alignment) alignas(byte_alignment)
 #endif
 
-#define PROTOBUF_FINAL final
-
+#ifdef PROTOBUF_THREAD_LOCAL
+#error PROTOBUF_THREAD_LOCAL was previously defined
+#endif
 #if defined(_MSC_VER)
 #define PROTOBUF_THREAD_LOCAL __declspec(thread)
 #else
@@ -575,33 +471,31 @@
 // 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
-
+#ifdef PROTOBUF_CONSTINIT
+#error PROTOBUF_CONSTINIT was previously defined
+#endif
+#if defined(__cpp_constinit) && !PROTOBUF_GNUC_MIN(3, 0)
 // Our use of constinit does not yet work with GCC:
 // https://github.com/protocolbuffers/protobuf/issues/8310
-#if defined(__cpp_constinit) && !defined(__GNUC__)
 #define PROTOBUF_CONSTINIT constinit
-#elif defined(__has_cpp_attribute)
-#if __has_cpp_attribute(clang::require_constant_initialization)
+#elif __has_cpp_attribute(clang::require_constant_initialization)
 #define PROTOBUF_CONSTINIT [[clang::require_constant_initialization]]
-#endif
-#endif
-#ifndef PROTOBUF_CONSTINIT
+#else
 #define PROTOBUF_CONSTINIT
 #endif
 
 // Some globals with an empty non-trivial destructor are annotated with
 // no_destroy for performance reasons. It reduces the cost of these globals in
 // non-opt mode and under sanitizers.
-#if defined(__has_cpp_attribute)
+#ifdef PROTOBUF_ATTRIBUTE_NO_DESTROY
+#error PROTOBUF_ATTRIBUTE_NO_DESTROY was previously defined
+#endif
 #if __has_cpp_attribute(clang::no_destroy)
 #define PROTOBUF_ATTRIBUTE_NO_DESTROY [[clang::no_destroy]]
-#endif
-#endif
-#if !defined(PROTOBUF_ATTRIBUTE_NO_DESTROY)
+#else
 #define PROTOBUF_ATTRIBUTE_NO_DESTROY
 #endif
 
-#if defined(__GNUC__)
 // Protobuf extensions and reflection require registration of the protos linked
 // in the binary. Not until everything is registered does the runtime have a
 // complete view on all protos. When code is using reflection or extensions
@@ -609,27 +503,43 @@
 // having the registration run first we mitigate this scenario.
 // Highest priority is 101. We use 102 to allow code that really wants to
 // higher priority to still beat us.
+#ifdef PROTOBUF_ATTRIBUTE_INIT_PRIORITY
+#error PROTOBUF_ATTRIBUTE_INIT_PRIORITY was previously defined
+#endif
+#if PROTOBUF_GNUC_MIN(3, 0)
 #define PROTOBUF_ATTRIBUTE_INIT_PRIORITY __attribute__((init_priority((102))))
 #else
 #define PROTOBUF_ATTRIBUTE_INIT_PRIORITY
 #endif
 
+#ifdef PROTOBUF_PRAGMA_INIT_SEG
+#error PROTOBUF_PRAGMA_INIT_SEG was previously defined
+#endif
 #if _MSC_VER
 #define PROTOBUF_PRAGMA_INIT_SEG __pragma(init_seg(lib))
 #else
 #define PROTOBUF_PRAGMA_INIT_SEG
 #endif
 
-#if defined(__has_attribute) && !defined(__MINGW32__)
-#if __has_attribute(weak)
-#define PROTOBUF_ATTRIBUTE_WEAK __attribute__((weak))
-#endif
+#ifdef PROTOBUF_ATTRIBUTE_WEAK
+#error PROTOBUF_ATTRIBUTE_WEAK was previously defined
 #endif
-#if !defined(PROTOBUF_ATTRIBUTE_WEAK)
+#if __has_attribute(weak) && !defined(__MINGW32__)
+#define PROTOBUF_ATTRIBUTE_WEAK __attribute__((weak))
+#else
 #define PROTOBUF_ATTRIBUTE_WEAK
 #endif
 
 // Macros to detect sanitizers.
+#ifdef PROTOBUF_ASAN
+#error PROTOBUF_ASAN was previously defined
+#endif
+#ifdef PROTOBUF_MSAN
+#error PROTOBUF_MSAN was previously defined
+#endif
+#ifdef PROTOBUF_TSAN
+#error PROTOBUF_TSAN was previously defined
+#endif
 #if defined(__clang__)
 #  if __has_feature(address_sanitizer)
 #    define PROTOBUF_ASAN 1
@@ -640,11 +550,92 @@
 #  if __has_feature(memory_sanitizer)
 #    define PROTOBUF_MSAN 1
 #  endif
-#elif defined(__GNUC__)
+#elif PROTOBUF_GNUC_MIN(3, 0)
 #  define PROTOBUF_ASAN __SANITIZE_ADDRESS__
 #  define PROTOBUF_TSAN __SANITIZE_THREAD__
 #endif
 
+#ifdef PROTOBUF_UNUSED
+#error PROTOBUF_UNUSED was previously defined
+#endif
+#if __has_cpp_attribute(unused) || \
+    (PROTOBUF_GNUC_MIN(3, 0) && !defined(__clang__))
+#define PROTOBUF_UNUSED __attribute__((__unused__))
+#else
+#define PROTOBUF_UNUSED
+#endif
+
+// Windows declares several inconvenient macro names.  We #undef them and then
+// restore them in port_undef.inc.
+#ifdef _MSC_VER
+#pragma push_macro("CREATE_NEW")
+#undef CREATE_NEW
+#pragma push_macro("DELETE")
+#undef DELETE
+#pragma push_macro("DOUBLE_CLICK")
+#undef DOUBLE_CLICK
+#pragma push_macro("ERROR")
+#undef ERROR
+#pragma push_macro("ERROR_BUSY")
+#undef ERROR_BUSY
+#pragma push_macro("ERROR_INSTALL_FAILED")
+#undef ERROR_INSTALL_FAILED
+#pragma push_macro("ERROR_NOT_FOUND")
+#undef ERROR_NOT_FOUND
+#pragma push_macro("GetMessage")
+#undef GetMessage
+#pragma push_macro("IGNORE")
+#undef IGNORE
+#pragma push_macro("IN")
+#undef IN
+#pragma push_macro("INPUT_KEYBOARD")
+#undef INPUT_KEYBOARD
+#pragma push_macro("NO_ERROR")
+#undef NO_ERROR
+#pragma push_macro("OUT")
+#undef OUT
+#pragma push_macro("OPTIONAL")
+#undef OPTIONAL
+#pragma push_macro("min")
+#undef min
+#pragma push_macro("max")
+#undef max
+#pragma push_macro("NEAR")
+#undef NEAR
+#pragma push_macro("NO_DATA")
+#undef NO_DATA
+#pragma push_macro("REASON_UNKNOWN")
+#undef REASON_UNKNOWN
+#pragma push_macro("SERVICE_DISABLED")
+#undef SERVICE_DISABLED
+#pragma push_macro("SEVERITY_ERROR")
+#undef SEVERITY_ERROR
+#pragma push_macro("STRICT")
+#undef STRICT
+#pragma push_macro("timezone")
+#undef timezone
+#endif  // _MSC_VER
+
+#if defined(__clang__) || PROTOBUF_GNUC_MIN(3, 0) || defined(_MSC_VER)
+// Don't let Objective-C Macros interfere with proto identifiers with the same
+// name.
+#pragma push_macro("DEBUG")
+#undef DEBUG
+#endif // defined(__clang__) || PROTOBUF_GNUC_MIN(3, 0) || defined(_MSC_VER)
+
+#if defined(__clang__)
+#pragma clang diagnostic push
+// TODO(gerbens) ideally we cleanup the code. But a cursory try shows many
+// violations. So let's ignore for now.
+#pragma clang diagnostic ignored "-Wshorten-64-to-32"
+#elif PROTOBUF_GNUC_MIN(3, 0)
+// GCC does not allow disabling diagnostics within an expression:
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60875, so we disable this one
+// globally even though it's only used for PROTOBUF_FIELD_OFFSET.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+#endif
+
 // Silence some MSVC warnings in all our code.
 #if _MSC_VER
 #pragma warning(push)
@@ -656,3 +647,28 @@
 // To silence the fact that we will pop this push from another file
 #pragma warning(disable : 5031)
 #endif
+
+// We don't want code outside port_def doing complex testing, so
+// remove our portable condition test macros to nudge folks away from
+// using it themselves.
+#ifdef PROTOBUF_has_cpp_attribute_DEFINED_
+#  undef __has_cpp_attribute
+#  undef PROTOBUF_has_cpp_attribute_DEFINED_
+#endif
+#ifdef PROTOBUF_has_feature_DEFINED_
+#  undef __has_feature
+#  undef PROTOBUF_has_feature_DEFINED_
+#endif
+#ifdef PROTOBUF_has_warning_DEFINED_
+#  undef __has_warning
+#  undef PROTOBUF_has_warning_DEFINED_
+#endif
+#ifdef PROTOBUF_has_attribute_DEFINED_
+#  undef __has_attribute
+#  undef PROTOBUF_has_attribute_DEFINED_
+#endif
+#ifdef PROTOBUF_has_builtin_DEFINED_
+#  undef __has_builtin
+#  undef PROTOBUF_has_builtin_DEFINED_
+#endif
+#undef PROTOBUF_GNUC_MIN

src/google/protobuf/port_undef.inc

@@ -55,10 +55,6 @@
 #undef PROTOBUF_MIN_PROTOC_VERSION
 #undef PROTOBUF_PREDICT_TRUE
 #undef PROTOBUF_PREDICT_FALSE
-#undef PROTOBUF_LONGLONG
-#undef PROTOBUF_ULONGLONG
-#undef PROTOBUF_LL_FORMAT
-#undef PROTOBUF_GUARDED_BY
 #undef PROTOBUF_FALLTHROUGH_INTENDED
 #undef PROTOBUF_EXPORT
 #undef PROTOC_EXPORT
@@ -70,7 +66,6 @@
 #undef PROTOBUF_EXPORT_TEMPLATE_DECLARE
 #undef PROTOBUF_EXPORT_TEMPLATE_DEFINE
 #undef PROTOBUF_ALIGNAS
-#undef PROTOBUF_FINAL
 #undef PROTOBUF_THREAD_LOCAL
 #undef PROTOBUF_MESSAGE_OWNED_ARENA_EXPERIMENT
 #undef PROTOBUF_CONSTINIT
@@ -81,6 +76,10 @@
 #undef PROTOBUF_ASAN
 #undef PROTOBUF_MSAN
 #undef PROTOBUF_TSAN
+#undef PROTOBUF_EXCLUSIVE_LOCKS_REQUIRED
+#undef PROTOBUF_LOCKS_EXCLUDED
+#undef PROTOBUF_NO_THREAD_SAFETY_ANALYSIS
+#undef PROTOBUF_GUARDED_BY
 
 #ifdef PROTOBUF_FUTURE_BREAKING_CHANGES
 #undef PROTOBUF_FUTURE_BREAKING_CHANGES

src/google/protobuf/reflection_ops.cc

@@ -418,19 +418,24 @@ void ReflectionOps::FindInitializationErrors(const Message& message,
   }
 }
 
-void GenericSwap(Message* m1, Message* m2) {
-  Arena* m2_arena = m2->GetArena();
-  GOOGLE_DCHECK(m1->GetArena() != m2_arena);
-
-  // Copy semantics in this case. We try to improve efficiency by placing the
-  // temporary on |m2|'s arena so that messages are copied twice rather than
-  // three times.
-  Message* tmp = m2->New(m2_arena);
-  std::unique_ptr<Message> tmp_deleter(m2_arena == nullptr ? tmp : nullptr);
-  tmp->CheckTypeAndMergeFrom(*m1);
-  m1->Clear();
-  m1->CheckTypeAndMergeFrom(*m2);
-  m2->GetReflection()->Swap(tmp, m2);
+void GenericSwap(Message* lhs, Message* rhs) {
+  GOOGLE_DCHECK(Arena::InternalHelper<Message>::GetOwningArena(lhs) !=
+         Arena::InternalHelper<Message>::GetOwningArena(rhs));
+  // At least one of these must have an arena, so make `rhs` point to it.
+  Arena* arena = Arena::InternalHelper<Message>::GetOwningArena(rhs);
+  if (arena == nullptr) {
+    std::swap(lhs, rhs);
+    arena = Arena::InternalHelper<Message>::GetOwningArena(rhs);
+  }
+
+  // Improve efficiency by placing the temporary on an arena so that messages
+  // are copied twice rather than three times.
+  GOOGLE_DCHECK(arena != nullptr);
+  Message* tmp = rhs->New(arena);
+  tmp->CheckTypeAndMergeFrom(*lhs);
+  lhs->Clear();
+  lhs->CheckTypeAndMergeFrom(*rhs);
+  rhs->GetReflection()->Swap(tmp, rhs);
 }
 
 }  // namespace internal

src/google/protobuf/reflection_ops_unittest.cc

@@ -535,8 +535,8 @@ TEST(ReflectionOpsTest, GenericSwap) {
 
     TestUtil::ExpectAllFieldsSet(message);
     TestUtil::ExpectClear(*arena_message);
-    // The temp shouldn't be allocated on the arena in this case.
-    EXPECT_EQ(arena.SpaceUsed(), initial_arena_size);
+    // The temp should be allocated on the arena in this case.
+    EXPECT_GT(arena.SpaceUsed(), initial_arena_size);
   }
 }
 

src/google/protobuf/repeated_field.h

@@ -595,12 +595,10 @@ class PROTOBUF_EXPORT RepeatedPtrFieldBase {
 #endif
   }
 
- public:
   // Must be called from destructor.
   template <typename TypeHandler>
   void Destroy();
 
- protected:
   bool empty() const;
   int size() const;
 
@@ -800,6 +798,7 @@ class PROTOBUF_EXPORT RepeatedPtrFieldBase {
   // reinterpreting pointers as being to Message instead of a specific Message
   // subclass.
   friend class MapFieldBase;
+  friend class MapFieldBaseStub;
 
   // The table-driven MergePartialFromCodedStream implementation needs to
   // operate on RepeatedPtrField<MessageLite>.
@@ -830,11 +829,8 @@ class GenericTypeHandler {
       delete value;
     }
   }
-  static inline Arena* GetArena(GenericType* value) {
-    return Arena::GetArena<Type>(value);
-  }
-  static inline void* GetMaybeArenaPointer(GenericType* value) {
-    return Arena::GetArena<Type>(value);
+  static inline Arena* GetOwningArena(GenericType* value) {
+    return Arena::GetOwningArena<Type>(value);
   }
 
   static inline void Clear(GenericType* value) { value->Clear(); }
@@ -863,13 +859,9 @@ template <>
 MessageLite* GenericTypeHandler<MessageLite>::NewFromPrototype(
     const MessageLite* prototype, Arena* arena);
 template <>
-inline Arena* GenericTypeHandler<MessageLite>::GetArena(MessageLite* value) {
-  return value->GetArena();
-}
-template <>
-inline void* GenericTypeHandler<MessageLite>::GetMaybeArenaPointer(
+inline Arena* GenericTypeHandler<MessageLite>::GetOwningArena(
     MessageLite* value) {
-  return value->GetMaybeArenaPointer();
+  return value->GetOwningArena();
 }
 template <>
 void GenericTypeHandler<MessageLite>::Merge(const MessageLite& from,
@@ -889,9 +881,7 @@ template <>
 PROTOBUF_EXPORT Message* GenericTypeHandler<Message>::NewFromPrototype(
     const Message* prototype, Arena* arena);
 template <>
-PROTOBUF_EXPORT Arena* GenericTypeHandler<Message>::GetArena(Message* value);
-template <>
-PROTOBUF_EXPORT void* GenericTypeHandler<Message>::GetMaybeArenaPointer(
+PROTOBUF_EXPORT Arena* GenericTypeHandler<Message>::GetOwningArena(
     Message* value);
 
 class StringTypeHandler {
@@ -909,10 +899,7 @@ class StringTypeHandler {
                                               Arena* arena) {
     return New(arena);
   }
-  static inline Arena* GetArena(std::string*) { return NULL; }
-  static inline void* GetMaybeArenaPointer(std::string* /* value */) {
-    return NULL;
-  }
+  static inline Arena* GetOwningArena(std::string*) { return nullptr; }
   static inline void Delete(std::string* value, Arena* arena) {
     if (arena == NULL) {
       delete value;
@@ -1496,7 +1483,6 @@ inline const Element* RepeatedField<Element>::data() const {
 template <typename Element>
 inline void RepeatedField<Element>::InternalSwap(RepeatedField* other) {
   GOOGLE_DCHECK(this != other);
-  GOOGLE_DCHECK(GetArena() == other->GetArena());
 
   // Swap all fields at once.
   static_assert(std::is_standard_layout<RepeatedField<Element>>::value,
@@ -1944,7 +1930,7 @@ template <typename TypeHandler>
 void RepeatedPtrFieldBase::AddAllocatedInternal(
     typename TypeHandler::Type* value, std::true_type) {
   Arena* element_arena =
-      reinterpret_cast<Arena*>(TypeHandler::GetMaybeArenaPointer(value));
+      reinterpret_cast<Arena*>(TypeHandler::GetOwningArena(value));
   Arena* arena = GetArena();
   if (arena == element_arena && rep_ && rep_->allocated_size < total_size_) {
     // Fast path: underlying arena representation (tagged pointer) is equal to
@@ -1960,8 +1946,7 @@ void RepeatedPtrFieldBase::AddAllocatedInternal(
     current_size_ = current_size_ + 1;
     rep_->allocated_size = rep_->allocated_size + 1;
   } else {
-    AddAllocatedSlowWithCopy<TypeHandler>(value, TypeHandler::GetArena(value),
-                                          arena);
+    AddAllocatedSlowWithCopy<TypeHandler>(value, element_arena, arena);
   }
 }
 
@@ -2093,7 +2078,7 @@ inline void RepeatedPtrFieldBase::AddCleared(
     typename TypeHandler::Type* value) {
   GOOGLE_DCHECK(GetArena() == NULL)
       << "AddCleared() can only be used on a RepeatedPtrField not on an arena.";
-  GOOGLE_DCHECK(TypeHandler::GetArena(value) == NULL)
+  GOOGLE_DCHECK(TypeHandler::GetOwningArena(value) == nullptr)
       << "AddCleared() can only accept values not on an arena.";
   if (!rep_ || rep_->allocated_size == total_size_) {
     Reserve(total_size_ + 1);
@@ -2635,17 +2620,14 @@ class RepeatedPtrOverPtrsIterator {
 
 void RepeatedPtrFieldBase::InternalSwap(RepeatedPtrFieldBase* other) {
   GOOGLE_DCHECK(this != other);
-  GOOGLE_DCHECK(GetArena() == other->GetArena());
 
   // Swap all fields at once.
   static_assert(std::is_standard_layout<RepeatedPtrFieldBase>::value,
                 "offsetof() requires standard layout before c++17");
   internal::memswap<offsetof(RepeatedPtrFieldBase, rep_) + sizeof(this->rep_) -
-                    offsetof(RepeatedPtrFieldBase, current_size_)>(
-      reinterpret_cast<char*>(this) +
-          offsetof(RepeatedPtrFieldBase, current_size_),
-      reinterpret_cast<char*>(other) +
-          offsetof(RepeatedPtrFieldBase, current_size_));
+                    offsetof(RepeatedPtrFieldBase, arena_)>(
+      reinterpret_cast<char*>(this) + offsetof(RepeatedPtrFieldBase, arena_),
+      reinterpret_cast<char*>(other) + offsetof(RepeatedPtrFieldBase, arena_));
 }
 
 }  // namespace internal

src/google/protobuf/source_context.pb.cc

@@ -91,7 +91,7 @@ SourceContext::SourceContext(const SourceContext& from)
   file_name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_file_name().empty()) {
     file_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_file_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   // @@protoc_insertion_point(copy_constructor:google.protobuf.SourceContext)
 }
@@ -107,7 +107,7 @@ SourceContext::~SourceContext() {
 }
 
 void SourceContext::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   file_name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -176,7 +176,7 @@ failure:
   (void) cached_has_bits;
 
   // string file_name = 1;
-  if (this->file_name().size() > 0) {
+  if (!this->file_name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_file_name().data(), static_cast<int>(this->_internal_file_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -202,7 +202,7 @@ size_t SourceContext::ByteSizeLong() const {
   (void) cached_has_bits;
 
   // string file_name = 1;
-  if (this->file_name().size() > 0) {
+  if (!this->file_name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_file_name());
@@ -239,7 +239,7 @@ void SourceContext::MergeFrom(const SourceContext& from) {
   ::PROTOBUF_NAMESPACE_ID::uint32 cached_has_bits = 0;
   (void) cached_has_bits;
 
-  if (from.file_name().size() > 0) {
+  if (!from.file_name().empty()) {
     _internal_set_file_name(from._internal_file_name());
   }
 }
@@ -265,7 +265,11 @@ bool SourceContext::IsInitialized() const {
 void SourceContext::InternalSwap(SourceContext* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
-  file_name_.Swap(&other->file_name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &file_name_, GetArenaForAllocation(),
+      &other->file_name_, other->GetArenaForAllocation()
+  );
 }
 
 ::PROTOBUF_NAMESPACE_ID::Metadata SourceContext::GetMetadata() const {

src/google/protobuf/source_context.pb.h

@@ -65,7 +65,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT SourceContext PROTOBUF_FINAL :
+class PROTOBUF_EXPORT SourceContext final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.SourceContext) */ {
  public:
   inline SourceContext() : SourceContext(nullptr) {}
@@ -83,8 +83,9 @@ class PROTOBUF_EXPORT SourceContext PROTOBUF_FINAL :
     return *this;
   }
   inline SourceContext& operator=(SourceContext&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -115,7 +116,7 @@ class PROTOBUF_EXPORT SourceContext PROTOBUF_FINAL :
   }
   inline void Swap(SourceContext* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -123,14 +124,14 @@ class PROTOBUF_EXPORT SourceContext PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(SourceContext* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline SourceContext* New() const final {
-    return CreateMaybeMessage<SourceContext>(nullptr);
+    return new SourceContext();
   }
 
   SourceContext* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -180,11 +181,11 @@ class PROTOBUF_EXPORT SourceContext PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_file_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_file_name();
-  std::string* release_file_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_file_name();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_file_name(const std::string& value);
   std::string* _internal_mutable_file_name();
   public:
 
@@ -219,10 +220,10 @@ inline const std::string& SourceContext::file_name() const {
   return _internal_file_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void SourceContext::set_file_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void SourceContext::set_file_name(ArgT0&& arg0, ArgT... args) {
  
- file_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ file_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.SourceContext.file_name)
 }
 inline std::string* SourceContext::mutable_file_name() {
@@ -234,15 +235,15 @@ inline const std::string& SourceContext::_internal_file_name() const {
 }
 inline void SourceContext::_internal_set_file_name(const std::string& value) {
   
-  file_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  file_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* SourceContext::_internal_mutable_file_name() {
   
-  return file_name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return file_name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* SourceContext::release_file_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.SourceContext.file_name)
-  return file_name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return file_name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void SourceContext::set_allocated_file_name(std::string* file_name) {
   if (file_name != nullptr) {
@@ -251,7 +252,7 @@ inline void SourceContext::set_allocated_file_name(std::string* file_name) {
     
   }
   file_name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), file_name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.SourceContext.file_name)
 }
 

src/google/protobuf/struct.pb.cc

@@ -213,14 +213,18 @@ Struct::~Struct() {
 }
 
 void Struct::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void Struct::ArenaDtor(void* object) {
   Struct* _this = reinterpret_cast< Struct* >(object);
   (void)_this;
+  _this->fields_. ~MapField();
 }
-void Struct::RegisterArenaDtor(::PROTOBUF_NAMESPACE_ID::Arena*) {
+inline void Struct::RegisterArenaDtor(::PROTOBUF_NAMESPACE_ID::Arena* arena) {
+  if (arena != nullptr) {
+    arena->OwnCustomDestructor(this, &Struct::ArenaDtor);
+  }
 }
 void Struct::SetCachedSize(int size) const {
   _cached_size_.Set(size);
@@ -291,6 +295,7 @@ failure:
     typedef ::PROTOBUF_NAMESPACE_ID::internal::CompareByDerefFirst<SortItem> Less;
     struct Utf8Check {
       static void Check(ConstPtr p) {
+        (void)p;
         ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
           p->first.data(), static_cast<int>(p->first.length()),
           ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -430,11 +435,11 @@ Value::_Internal::list_value(const Value* msg) {
   return *msg->kind_.list_value_;
 }
 void Value::set_allocated_struct_value(PROTOBUF_NAMESPACE_ID::Struct* struct_value) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   clear_kind();
   if (struct_value) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      ::PROTOBUF_NAMESPACE_ID::Arena::GetArena(struct_value);
+      ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<PROTOBUF_NAMESPACE_ID::Struct>::GetOwningArena(struct_value);
     if (message_arena != submessage_arena) {
       struct_value = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, struct_value, submessage_arena);
@@ -445,11 +450,11 @@ void Value::set_allocated_struct_value(PROTOBUF_NAMESPACE_ID::Struct* struct_val
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Value.struct_value)
 }
 void Value::set_allocated_list_value(PROTOBUF_NAMESPACE_ID::ListValue* list_value) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   clear_kind();
   if (list_value) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      ::PROTOBUF_NAMESPACE_ID::Arena::GetArena(list_value);
+      ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<PROTOBUF_NAMESPACE_ID::ListValue>::GetOwningArena(list_value);
     if (message_arena != submessage_arena) {
       list_value = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, list_value, submessage_arena);
@@ -512,7 +517,7 @@ Value::~Value() {
 }
 
 void Value::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   if (has_kind()) {
     clear_kind();
   }
@@ -540,7 +545,7 @@ void Value::clear_kind() {
       break;
     }
     case kStringValue: {
-      kind_.string_value_.Destroy(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+      kind_.string_value_.Destroy(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
       break;
     }
     case kBoolValue: {
@@ -548,13 +553,13 @@ void Value::clear_kind() {
       break;
     }
     case kStructValue: {
-      if (GetArena() == nullptr) {
+      if (GetArenaForAllocation() == nullptr) {
         delete kind_.struct_value_;
       }
       break;
     }
     case kListValue: {
-      if (GetArena() == nullptr) {
+      if (GetArenaForAllocation() == nullptr) {
         delete kind_.list_value_;
       }
       break;
@@ -883,7 +888,7 @@ ListValue::~ListValue() {
 }
 
 void ListValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void ListValue::ArenaDtor(void* object) {

src/google/protobuf/struct.pb.h

@@ -130,7 +130,7 @@ public:
 
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Struct PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Struct final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Struct) */ {
  public:
   inline Struct() : Struct(nullptr) {}
@@ -148,8 +148,9 @@ class PROTOBUF_EXPORT Struct PROTOBUF_FINAL :
     return *this;
   }
   inline Struct& operator=(Struct&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -180,7 +181,7 @@ class PROTOBUF_EXPORT Struct PROTOBUF_FINAL :
   }
   inline void Swap(Struct* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -188,14 +189,14 @@ class PROTOBUF_EXPORT Struct PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Struct* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Struct* New() const final {
-    return CreateMaybeMessage<Struct>(nullptr);
+    return new Struct();
   }
 
   Struct* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -274,7 +275,7 @@ class PROTOBUF_EXPORT Struct PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Value PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Value final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Value) */ {
  public:
   inline Value() : Value(nullptr) {}
@@ -292,8 +293,9 @@ class PROTOBUF_EXPORT Value PROTOBUF_FINAL :
     return *this;
   }
   inline Value& operator=(Value&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -334,7 +336,7 @@ class PROTOBUF_EXPORT Value PROTOBUF_FINAL :
   }
   inline void Swap(Value* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -342,14 +344,14 @@ class PROTOBUF_EXPORT Value PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Value* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Value* New() const final {
-    return CreateMaybeMessage<Value>(nullptr);
+    return new Value();
   }
 
   Value* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -434,11 +436,11 @@ class PROTOBUF_EXPORT Value PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_string_value(ArgT0&& arg0, ArgT... args);
   std::string* mutable_string_value();
-  std::string* release_string_value();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_string_value();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_string_value(const std::string& value);
   std::string* _internal_mutable_string_value();
   public:
 
@@ -526,7 +528,7 @@ class PROTOBUF_EXPORT Value PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT ListValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT ListValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.ListValue) */ {
  public:
   inline ListValue() : ListValue(nullptr) {}
@@ -544,8 +546,9 @@ class PROTOBUF_EXPORT ListValue PROTOBUF_FINAL :
     return *this;
   }
   inline ListValue& operator=(ListValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -576,7 +579,7 @@ class PROTOBUF_EXPORT ListValue PROTOBUF_FINAL :
   }
   inline void Swap(ListValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -584,14 +587,14 @@ class PROTOBUF_EXPORT ListValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(ListValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline ListValue* New() const final {
-    return CreateMaybeMessage<ListValue>(nullptr);
+    return new ListValue();
   }
 
   ListValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -798,7 +801,7 @@ inline void Value::set_has_string_value() {
 }
 inline void Value::clear_string_value() {
   if (_internal_has_string_value()) {
-    kind_.string_value_.Destroy(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+    kind_.string_value_.Destroy(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
     clear_has_kind();
   }
 }
@@ -813,7 +816,7 @@ inline void Value::set_string_value(ArgT0&& arg0, ArgT... args) {
     set_has_string_value();
     kind_.string_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   }
-  kind_.string_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+  kind_.string_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Value.string_value)
 }
 inline std::string* Value::mutable_string_value() {
@@ -832,7 +835,7 @@ inline void Value::_internal_set_string_value(const std::string& value) {
     set_has_string_value();
     kind_.string_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   }
-  kind_.string_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  kind_.string_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Value::_internal_mutable_string_value() {
   if (!_internal_has_string_value()) {
@@ -841,13 +844,13 @@ inline std::string* Value::_internal_mutable_string_value() {
     kind_.string_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   }
   return kind_.string_value_.Mutable(
-      ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+      ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Value::release_string_value() {
   // @@protoc_insertion_point(field_release:google.protobuf.Value.string_value)
   if (_internal_has_string_value()) {
     clear_has_kind();
-    return kind_.string_value_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+    return kind_.string_value_.ReleaseNonDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
   } else {
     return nullptr;
   }
@@ -859,7 +862,7 @@ inline void Value::set_allocated_string_value(std::string* string_value) {
   if (string_value != nullptr) {
     set_has_string_value();
     kind_.string_value_.UnsafeSetDefault(string_value);
-    ::PROTOBUF_NAMESPACE_ID::Arena* arena = GetArena();
+    ::PROTOBUF_NAMESPACE_ID::Arena* arena = GetArenaForAllocation();
     if (arena != nullptr) {
       arena->Own(string_value);
     }
@@ -917,7 +920,7 @@ inline void Value::set_has_struct_value() {
 }
 inline void Value::clear_struct_value() {
   if (_internal_has_struct_value()) {
-    if (GetArena() == nullptr) {
+    if (GetArenaForAllocation() == nullptr) {
       delete kind_.struct_value_;
     }
     clear_has_kind();
@@ -928,7 +931,7 @@ inline PROTOBUF_NAMESPACE_ID::Struct* Value::release_struct_value() {
   if (_internal_has_struct_value()) {
     clear_has_kind();
       PROTOBUF_NAMESPACE_ID::Struct* temp = kind_.struct_value_;
-    if (GetArena() != nullptr) {
+    if (GetArenaForAllocation() != nullptr) {
       temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
     }
     kind_.struct_value_ = nullptr;
@@ -969,7 +972,7 @@ inline PROTOBUF_NAMESPACE_ID::Struct* Value::_internal_mutable_struct_value() {
   if (!_internal_has_struct_value()) {
     clear_kind();
     set_has_struct_value();
-    kind_.struct_value_ = CreateMaybeMessage< PROTOBUF_NAMESPACE_ID::Struct >(GetArena());
+    kind_.struct_value_ = CreateMaybeMessage< PROTOBUF_NAMESPACE_ID::Struct >(GetArenaForAllocation());
   }
   return kind_.struct_value_;
 }
@@ -990,7 +993,7 @@ inline void Value::set_has_list_value() {
 }
 inline void Value::clear_list_value() {
   if (_internal_has_list_value()) {
-    if (GetArena() == nullptr) {
+    if (GetArenaForAllocation() == nullptr) {
       delete kind_.list_value_;
     }
     clear_has_kind();
@@ -1001,7 +1004,7 @@ inline PROTOBUF_NAMESPACE_ID::ListValue* Value::release_list_value() {
   if (_internal_has_list_value()) {
     clear_has_kind();
       PROTOBUF_NAMESPACE_ID::ListValue* temp = kind_.list_value_;
-    if (GetArena() != nullptr) {
+    if (GetArenaForAllocation() != nullptr) {
       temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
     }
     kind_.list_value_ = nullptr;
@@ -1042,7 +1045,7 @@ inline PROTOBUF_NAMESPACE_ID::ListValue* Value::_internal_mutable_list_value() {
   if (!_internal_has_list_value()) {
     clear_kind();
     set_has_list_value();
-    kind_.list_value_ = CreateMaybeMessage< PROTOBUF_NAMESPACE_ID::ListValue >(GetArena());
+    kind_.list_value_ = CreateMaybeMessage< PROTOBUF_NAMESPACE_ID::ListValue >(GetArenaForAllocation());
   }
   return kind_.list_value_;
 }

src/google/protobuf/stubs/common.cc

@@ -211,32 +211,29 @@ LogMessage& LogMessage::operator<<(const uint128& value) {
   return *this;
 }
 
-// Since this is just for logging, we don't care if the current locale changes
-// the results -- in fact, we probably prefer that.  So we use snprintf()
-// instead of Simple*toa().
+LogMessage& LogMessage::operator<<(char value) {
+  return *this << StringPiece(&value, 1);
+}
+
+LogMessage& LogMessage::operator<<(void* value) {
+  StrAppend(&message_, strings::Hex(reinterpret_cast<uintptr_t>(value)));
+  return *this;
+}
+
 #undef DECLARE_STREAM_OPERATOR
-#define DECLARE_STREAM_OPERATOR(TYPE, FORMAT)                       \
-  LogMessage& LogMessage::operator<<(TYPE value) {                  \
-    /* 128 bytes should be big enough for any of the primitive */   \
-    /* values which we print with this, but well use snprintf() */  \
-    /* anyway to be extra safe. */                                  \
-    char buffer[128];                                               \
-    snprintf(buffer, sizeof(buffer), FORMAT, value);                \
-    /* Guard against broken MSVC snprintf(). */                     \
-    buffer[sizeof(buffer)-1] = '\0';                                \
-    message_ += buffer;                                             \
-    return *this;                                                   \
+#define DECLARE_STREAM_OPERATOR(TYPE)              \
+  LogMessage& LogMessage::operator<<(TYPE value) { \
+    StrAppend(&message_, value);                   \
+    return *this;                                  \
   }
 
-DECLARE_STREAM_OPERATOR(char         , "%c" )
-DECLARE_STREAM_OPERATOR(int          , "%d" )
-DECLARE_STREAM_OPERATOR(unsigned int , "%u" )
-DECLARE_STREAM_OPERATOR(long         , "%ld")
-DECLARE_STREAM_OPERATOR(unsigned long, "%lu")
-DECLARE_STREAM_OPERATOR(double       , "%g" )
-DECLARE_STREAM_OPERATOR(void*        , "%p" )
-DECLARE_STREAM_OPERATOR(long long         , "%" PROTOBUF_LL_FORMAT "d")
-DECLARE_STREAM_OPERATOR(unsigned long long, "%" PROTOBUF_LL_FORMAT "u")
+DECLARE_STREAM_OPERATOR(int)
+DECLARE_STREAM_OPERATOR(unsigned int)
+DECLARE_STREAM_OPERATOR(long)           // NOLINT(runtime/int)
+DECLARE_STREAM_OPERATOR(unsigned long)  // NOLINT(runtime/int)
+DECLARE_STREAM_OPERATOR(double)
+DECLARE_STREAM_OPERATOR(long long)           // NOLINT(runtime/int)
+DECLARE_STREAM_OPERATOR(unsigned long long)  // NOLINT(runtime/int)
 #undef DECLARE_STREAM_OPERATOR
 
 LogMessage::LogMessage(LogLevel level, const char* filename, int line)

src/google/protobuf/stubs/int128.cc

@@ -41,10 +41,8 @@
 namespace google {
 namespace protobuf {
 
-const uint128_pod kuint128max = {
-    static_cast<uint64>(PROTOBUF_LONGLONG(0xFFFFFFFFFFFFFFFF)),
-    static_cast<uint64>(PROTOBUF_LONGLONG(0xFFFFFFFFFFFFFFFF))
-};
+const uint128_pod kuint128max = {uint64_t{0xFFFFFFFFFFFFFFFFu},
+                                 uint64_t{0xFFFFFFFFFFFFFFFFu}};
 
 // Returns the 0-based position of the last set bit (i.e., most significant bit)
 // in the given uint64. The argument may not be 0.
@@ -67,7 +65,7 @@ static inline int Fls64(uint64 n) {
   STEP(uint32, n32, pos, 0x10);
   STEP(uint32, n32, pos, 0x08);
   STEP(uint32, n32, pos, 0x04);
-  return pos + ((PROTOBUF_ULONGLONG(0x3333333322221100) >> (n32 << 2)) & 0x3);
+  return pos + ((uint64_t{0x3333333322221100u} >> (n32 << 2)) & 0x3);
 }
 #undef STEP
 
@@ -134,17 +132,17 @@ std::ostream& operator<<(std::ostream& o, const uint128& b) {
   switch (flags & std::ios::basefield) {
     case std::ios::hex:
       div =
-          static_cast<uint64>(PROTOBUF_ULONGLONG(0x1000000000000000));  // 16^15
+          static_cast<uint64>(uint64_t{0x1000000000000000u});  // 16^15
       div_base_log = 15;
       break;
     case std::ios::oct:
       div = static_cast<uint64>(
-          PROTOBUF_ULONGLONG(01000000000000000000000));  // 8^21
+          uint64_t{01000000000000000000000u});  // 8^21
       div_base_log = 21;
       break;
     default:  // std::ios::dec
       div = static_cast<uint64>(
-          PROTOBUF_ULONGLONG(10000000000000000000));  // 10^19
+          uint64_t{10000000000000000000u});  // 10^19
       div_base_log = 19;
       break;
   }

src/google/protobuf/stubs/int128_unittest.cc

@@ -293,26 +293,20 @@ TEST(Int128, Multiply) {
   }
 
   // Verified with dc.
-  a = uint128(PROTOBUF_ULONGLONG(0xffffeeeeddddcccc),
-              PROTOBUF_ULONGLONG(0xbbbbaaaa99998888));
-  b = uint128(PROTOBUF_ULONGLONG(0x7777666655554444),
-              PROTOBUF_ULONGLONG(0x3333222211110000));
+  a = uint128(uint64_t{0xffffeeeeddddccccu}, uint64_t{0xbbbbaaaa99998888u});
+  b = uint128(uint64_t{0x7777666655554444u}, uint64_t{0x3333222211110000u});
   c = a * b;
-  EXPECT_EQ(uint128(PROTOBUF_ULONGLONG(0x530EDA741C71D4C3),
-                    PROTOBUF_ULONGLONG(0xBF25975319080000)),
-            c);
+  EXPECT_EQ(
+      uint128(uint64_t{0x530EDA741C71D4C3u}, uint64_t{0xBF25975319080000u}), c);
   EXPECT_EQ(0, c - b * a);
   EXPECT_EQ(a * a - b * b, (a + b) * (a - b));
 
   // Verified with dc.
-  a = uint128(PROTOBUF_ULONGLONG(0x0123456789abcdef),
-              PROTOBUF_ULONGLONG(0xfedcba9876543210));
-  b = uint128(PROTOBUF_ULONGLONG(0x02468ace13579bdf),
-              PROTOBUF_ULONGLONG(0xfdb97531eca86420));
+  a = uint128(uint64_t{0x0123456789abcdefu}, uint64_t{0xfedcba9876543210u});
+  b = uint128(uint64_t{0x02468ace13579bdfu}, uint64_t{0xfdb97531eca86420u});
   c = a * b;
-  EXPECT_EQ(uint128(PROTOBUF_ULONGLONG(0x97a87f4f261ba3f2),
-                    PROTOBUF_ULONGLONG(0x342d0bbf48948200)),
-            c);
+  EXPECT_EQ(
+      uint128(uint64_t{0x97a87f4f261ba3f2u}, uint64_t{0x342d0bbf48948200u}), c);
   EXPECT_EQ(0, c - b * a);
   EXPECT_EQ(a*a - b*b, (a+b) * (a-b));
 }
@@ -359,10 +353,8 @@ TEST(Int128, DivideAndMod) {
   EXPECT_EQ(0, q);
   EXPECT_EQ(0, r);
 
-  a = uint128(PROTOBUF_ULONGLONG(0x530eda741c71d4c3),
-              PROTOBUF_ULONGLONG(0xbf25975319080000));
-  q = uint128(PROTOBUF_ULONGLONG(0x4de2cab081),
-              PROTOBUF_ULONGLONG(0x14c34ab4676e4bab));
+  a = uint128(uint64_t{0x530eda741c71d4c3u}, uint64_t{0xbf25975319080000u});
+  q = uint128(uint64_t{0x4de2cab081u}, uint64_t{0x14c34ab4676e4babu});
   b = uint128(0x1110001);
   r = uint128(0x3eb455);
   ASSERT_EQ(a, q * b + r);  // Sanity-check.
@@ -400,8 +392,8 @@ TEST(Int128, DivideAndMod) {
 
   // Try a large remainder.
   b = a / 2 + 1;
-  uint128 expected_r(PROTOBUF_ULONGLONG(0x29876d3a0e38ea61),
-                     PROTOBUF_ULONGLONG(0xdf92cba98c83ffff));
+  uint128 expected_r(uint64_t{0x29876d3a0e38ea61u},
+                     uint64_t{0xdf92cba98c83ffffu});
   // Sanity checks.
   ASSERT_EQ(a / 2 - 1, expected_r);
   ASSERT_EQ(a, b + expected_r);
@@ -471,12 +463,12 @@ TEST(Int128, OStream) {
       {uint128(1, 0), std::ios::oct, 0, '_', "2000000000000000000000"},
       {uint128(1, 0), std::ios::hex, 0, '_', "10000000000000000"},
       // just the top bit
-      {uint128(PROTOBUF_ULONGLONG(0x8000000000000000), 0), std::ios::dec, 0,
-       '_', "170141183460469231731687303715884105728"},
-      {uint128(PROTOBUF_ULONGLONG(0x8000000000000000), 0), std::ios::oct, 0,
-       '_', "2000000000000000000000000000000000000000000"},
-      {uint128(PROTOBUF_ULONGLONG(0x8000000000000000), 0), std::ios::hex, 0,
-       '_', "80000000000000000000000000000000"},
+      {uint128(uint64_t{0x8000000000000000u}, 0), std::ios::dec, 0, '_',
+       "170141183460469231731687303715884105728"},
+      {uint128(uint64_t{0x8000000000000000u}, 0), std::ios::oct, 0, '_',
+       "2000000000000000000000000000000000000000000"},
+      {uint128(uint64_t{0x8000000000000000u}, 0), std::ios::hex, 0, '_',
+       "80000000000000000000000000000000"},
       // maximum uint128 value
       {uint128(-1, -1), std::ios::dec, 0, '_',
        "340282366920938463463374607431768211455"},

src/google/protobuf/stubs/macros.h

@@ -35,8 +35,8 @@ namespace google {
 namespace protobuf {
 
 #undef GOOGLE_DISALLOW_EVIL_CONSTRUCTORS
-#define GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(TypeName)    \
-  TypeName(const TypeName&) = delete;                  \
+#define GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(TypeName) \
+  TypeName(const TypeName&) = delete;               \
   void operator=(const TypeName&) = delete
 
 #undef GOOGLE_DISALLOW_IMPLICIT_CONSTRUCTORS

src/google/protobuf/stubs/port.h

@@ -136,10 +136,10 @@ typedef uint64_t uint64;
 
 static const int32 kint32max = 0x7FFFFFFF;
 static const int32 kint32min = -kint32max - 1;
-static const int64 kint64max = PROTOBUF_LONGLONG(0x7FFFFFFFFFFFFFFF);
+static const int64 kint64max = int64_t{0x7FFFFFFFFFFFFFFF};
 static const int64 kint64min = -kint64max - 1;
 static const uint32 kuint32max = 0xFFFFFFFFu;
-static const uint64 kuint64max = PROTOBUF_ULONGLONG(0xFFFFFFFFFFFFFFFF);
+static const uint64 kuint64max = uint64_t{0xFFFFFFFFFFFFFFFFu};
 
 #if defined(ADDRESS_SANITIZER) || defined(THREAD_SANITIZER) ||\
     defined(MEMORY_SANITIZER)
@@ -263,14 +263,14 @@ static inline uint32 bswap_32(uint32 x) {
 
 #ifndef bswap_64
 static inline uint64 bswap_64(uint64 x) {
-  return (((x & PROTOBUF_ULONGLONG(0xFF)) << 56) |
-          ((x & PROTOBUF_ULONGLONG(0xFF00)) << 40) |
-          ((x & PROTOBUF_ULONGLONG(0xFF0000)) << 24) |
-          ((x & PROTOBUF_ULONGLONG(0xFF000000)) << 8) |
-          ((x & PROTOBUF_ULONGLONG(0xFF00000000)) >> 8) |
-          ((x & PROTOBUF_ULONGLONG(0xFF0000000000)) >> 24) |
-          ((x & PROTOBUF_ULONGLONG(0xFF000000000000)) >> 40) |
-          ((x & PROTOBUF_ULONGLONG(0xFF00000000000000)) >> 56));
+  return (((x & uint64_t{0xFFu)) << 56) |
+          ((x & uint64_t{0xFF00u)) << 40) |
+          ((x & uint64_t{0xFF0000u)) << 24) |
+          ((x & uint64_t{0xFF000000u)) << 8) |
+          ((x & uint64_t{0xFF00000000u)) >> 8) |
+          ((x & uint64_t{0xFF0000000000u)) >> 24) |
+          ((x & uint64_t{0xFF000000000000u)) >> 40) |
+          ((x & uint64_t{0xFF00000000000000u)) >> 56));
 }
 #define bswap_64(x) bswap_64(x)
 #endif

src/google/protobuf/stubs/stringpiece.cc

@@ -46,6 +46,10 @@ std::ostream& operator<<(std::ostream& o, StringPiece piece) {
   return o;
 }
 
+void StringPiece::LogFatalSizeTooBig(size_t size, const char* details) {
+  GOOGLE_LOG(FATAL) << "size too big: " << size << " details: " << details;
+}
+
 void StringPiece::CopyToString(std::string* target) const {
   target->assign(ptr_, length_);
 }
@@ -71,8 +75,8 @@ bool StringPiece::ConsumeFromEnd(StringPiece x) {
   return false;
 }
 
-StringPiece::size_type StringPiece::copy(
-    char* buf, size_type n, size_type pos) const {
+StringPiece::size_type StringPiece::copy(char* buf, size_type n,
+                                         size_type pos) const {
   size_type ret = std::min(length_ - pos, n);
   memcpy(buf, ptr_ + pos, ret);
   return ret;
@@ -82,8 +86,7 @@ bool StringPiece::contains(StringPiece s) const {
   return find(s, 0) != npos;
 }
 
-StringPiece::size_type StringPiece::find(
-    StringPiece s, size_type pos) const {
+StringPiece::size_type StringPiece::find(StringPiece s, size_type pos) const {
   if (length_ <= 0 || pos > static_cast<size_type>(length_)) {
     if (length_ == 0 && pos == 0 && s.length_ == 0) return 0;
     return npos;
@@ -116,12 +119,11 @@ StringPiece::size_type StringPiece::rfind(StringPiece s, size_type pos) const {
 StringPiece::size_type StringPiece::rfind(char c, size_type pos) const {
   // Note: memrchr() is not available on Windows.
   if (empty()) return npos;
-  for (difference_type i =
-      std::min(pos, static_cast<size_type>(length_ - 1));
-       i >= 0; --i) {
+  for (size_type i = std::min(pos, length_ - 1);; --i) {
     if (ptr_[i] == c) {
       return i;
     }
+    if (i == 0) break;
   }
   return npos;
 }
@@ -143,8 +145,8 @@ static inline void BuildLookupTable(StringPiece characters_wanted,
   }
 }
 
-StringPiece::size_type StringPiece::find_first_of(
-    StringPiece s, size_type pos) const {
+StringPiece::size_type StringPiece::find_first_of(StringPiece s,
+                                                  size_type pos) const {
   if (empty() || s.empty()) {
     return npos;
   }
@@ -161,8 +163,8 @@ StringPiece::size_type StringPiece::find_first_of(
   return npos;
 }
 
-StringPiece::size_type StringPiece::find_first_not_of(
-    StringPiece s, size_type pos) const {
+StringPiece::size_type StringPiece::find_first_not_of(StringPiece s,
+                                                      size_type pos) const {
   if (empty()) return npos;
   if (s.empty()) return 0;
   // Avoid the cost of BuildLookupTable() for a single-character search.
@@ -178,8 +180,8 @@ StringPiece::size_type StringPiece::find_first_not_of(
   return npos;
 }
 
-StringPiece::size_type StringPiece::find_first_not_of(
-    char c, size_type pos) const {
+StringPiece::size_type StringPiece::find_first_not_of(char c,
+                                                      size_type pos) const {
   if (empty()) return npos;
 
   for (; pos < static_cast<size_type>(length_); ++pos) {
@@ -190,28 +192,28 @@ StringPiece::size_type StringPiece::find_first_not_of(
   return npos;
 }
 
-StringPiece::size_type StringPiece::find_last_of(
-    StringPiece s, size_type pos) const {
+StringPiece::size_type StringPiece::find_last_of(StringPiece s,
+                                                 size_type pos) const {
   if (empty() || s.empty()) return npos;
   // Avoid the cost of BuildLookupTable() for a single-character search.
   if (s.length_ == 1) return find_last_of(s.ptr_[0], pos);
 
   bool lookup[UCHAR_MAX + 1] = { false };
   BuildLookupTable(s, lookup);
-  for (difference_type i =
-       std::min(pos, static_cast<size_type>(length_ - 1)); i >= 0; --i) {
+  for (size_type i = std::min(pos, length_ - 1);; --i) {
     if (lookup[static_cast<unsigned char>(ptr_[i])]) {
       return i;
     }
+    if (i == 0) break;
   }
   return npos;
 }
 
-StringPiece::size_type StringPiece::find_last_not_of(
-    StringPiece s, size_type pos) const {
+StringPiece::size_type StringPiece::find_last_not_of(StringPiece s,
+                                                     size_type pos) const {
   if (empty()) return npos;
 
-  size_type i = std::min(pos, length()-1);
+  size_type i = std::min(pos, length() - 1);
   if (s.empty()) return i;
 
   // Avoid the cost of BuildLookupTable() for a single-character search.
@@ -219,23 +221,24 @@ StringPiece::size_type StringPiece::find_last_not_of(
 
   bool lookup[UCHAR_MAX + 1] = { false };
   BuildLookupTable(s, lookup);
-  for (; i >= 0; --i) {
+  for (;; --i) {
     if (!lookup[static_cast<unsigned char>(ptr_[i])]) {
       return i;
     }
+    if (i == 0) break;
   }
   return npos;
 }
 
-StringPiece::size_type StringPiece::find_last_not_of(
-    char c, size_type pos) const {
+StringPiece::size_type StringPiece::find_last_not_of(char c,
+                                                     size_type pos) const {
   if (empty()) return npos;
-
-  for (difference_type i =
-       std::min(pos, static_cast<size_type>(length_ - 1)); i >= 0; --i) {
+  size_type i = std::min(pos, length_ - 1);
+  for (;; --i) {
     if (ptr_[i] != c) {
       return i;
     }
+    if (i == 0) break;
   }
   return npos;
 }

src/google/protobuf/stubs/stringpiece.h

@@ -175,6 +175,23 @@ class PROTOBUF_EXPORT StringPiece {
   const char* ptr_;
   size_type length_;
 
+  static constexpr size_type kMaxSize =
+      (std::numeric_limits<difference_type>::max)();
+
+  static size_type CheckSize(size_type size) {
+#if !defined(NDEBUG) || defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0
+    if (PROTOBUF_PREDICT_FALSE(size > kMaxSize)) {
+      // Some people grep for this message in logs
+      // so take care if you ever change it.
+      LogFatalSizeTooBig(size, "string length exceeds max size");
+    }
+#endif
+    return size;
+  }
+
+  // Out-of-line error path.
+  static void LogFatalSizeTooBig(size_type size, const char* details);
+
  public:
   // We provide non-explicit singleton constructors so users can pass
   // in a "const char*" or a "string" wherever a "StringPiece" is
@@ -187,7 +204,7 @@ class PROTOBUF_EXPORT StringPiece {
   StringPiece(const char* str)  // NOLINT(runtime/explicit)
       : ptr_(str), length_(0) {
     if (str != nullptr) {
-      length_ = strlen(str);
+      length_ = CheckSize(strlen(str));
     }
   }
 
@@ -195,11 +212,11 @@ class PROTOBUF_EXPORT StringPiece {
   StringPiece(  // NOLINT(runtime/explicit)
       const std::basic_string<char, std::char_traits<char>, Allocator>& str)
       : ptr_(str.data()), length_(0) {
-    length_ = str.size();
+    length_ = CheckSize(str.size());
   }
 
   StringPiece(const char* offset, size_type len)
-      : ptr_(offset), length_(len) {}
+      : ptr_(offset), length_(CheckSize(len)) {}
 
   // data() may return a pointer to a buffer with embedded NULs, and the
   // returned buffer may or may not be null terminated.  Therefore it is
@@ -304,8 +321,7 @@ class PROTOBUF_EXPORT StringPiece {
   size_type find_last_of(char c, size_type pos = npos) const {
     return rfind(c, pos);
   }
-  size_type find_last_not_of(StringPiece s,
-                                          size_type pos = npos) const;
+  size_type find_last_not_of(StringPiece s, size_type pos = npos) const;
   size_type find_last_not_of(char c, size_type pos = npos) const;
 
   StringPiece substr(size_type pos, size_type n = npos) const;

src/google/protobuf/stubs/stringpiece_unittest.cc

@@ -590,13 +590,13 @@ TEST(StringPiece, Custom) {
   }
 
   {
-  StringPiece str("foobar");
-  EXPECT_TRUE(str.ConsumeFromEnd("bar"));
-  EXPECT_EQ(str, "foo");
-  EXPECT_FALSE(str.ConsumeFromEnd("bar"));
-  EXPECT_FALSE(str.ConsumeFromEnd("foofoo"));
-  EXPECT_FALSE(str.ConsumeFromEnd("fo"));
-  EXPECT_EQ(str, "foo");
+    StringPiece str("foobar");
+    EXPECT_TRUE(str.ConsumeFromEnd("bar"));
+    EXPECT_EQ(str, "foo");
+    EXPECT_FALSE(str.ConsumeFromEnd("bar"));
+    EXPECT_FALSE(str.ConsumeFromEnd("foofoo"));
+    EXPECT_FALSE(str.ConsumeFromEnd("fo"));
+    EXPECT_EQ(str, "foo");
   }
 }
 
@@ -685,7 +685,7 @@ TEST(FindOneCharTest, EdgeCases) {
 #ifdef PROTOBUF_HAS_DEATH_TEST
 #ifndef NDEBUG
 TEST(NonNegativeLenTest, NonNegativeLen) {
-  EXPECT_DEATH(StringPiece("xyz", -1), "len >= 0");
+  EXPECT_DEATH(StringPiece("xyz", -1), "string length exceeds max size");
 }
 #endif  // ndef DEBUG
 #endif  // PROTOBUF_HAS_DEATH_TEST

src/google/protobuf/stubs/strutil.cc

@@ -1622,7 +1622,8 @@ int GlobalReplaceSubstring(const std::string &substring,
   for (StringPiece::size_type match_pos =
            s->find(substring.data(), pos, substring.length());
        match_pos != std::string::npos; pos = match_pos + substring.length(),
-           match_pos = s->find(substring.data(), pos, substring.length())) {
+                              match_pos = s->find(substring.data(), pos,
+                                                  substring.length())) {
     ++num_replacements;
     // Append the original content before the match.
     tmp.append(*s, pos, match_pos - pos);

src/google/protobuf/text_format_unittest.cc

@@ -1069,13 +1069,8 @@ static std::string RemoveRedundantZeros(std::string text) {
 TEST_F(TextFormatTest, PrintExotic) {
   unittest::TestAllTypes message;
 
-  // Note:  In C, a negative integer literal is actually the unary negation
-  //   operator being applied to a positive integer literal, and
-  //   9223372036854775808 is outside the range of int64.  However, it is not
-  //   outside the range of uint64.  Confusingly, this means that everything
-  //   works if we make the literal unsigned, even though we are negating it.
-  message.add_repeated_int64(-PROTOBUF_ULONGLONG(9223372036854775808));
-  message.add_repeated_uint64(PROTOBUF_ULONGLONG(18446744073709551615));
+  message.add_repeated_int64(int64_t{-9223372036854775807} - 1);
+  message.add_repeated_uint64(uint64_t{18446744073709551615u});
   message.add_repeated_double(123.456);
   message.add_repeated_double(1.23e21);
   message.add_repeated_double(1.23e-18);
@@ -1240,32 +1235,19 @@ TEST_F(TextFormatTest, ParseExotic) {
 
   ASSERT_EQ(2, message.repeated_int32_size());
   EXPECT_EQ(-1, message.repeated_int32(0));
-  // Note:  In C, a negative integer literal is actually the unary negation
-  //   operator being applied to a positive integer literal, and 2147483648 is
-  //   outside the range of int32.  However, it is not outside the range of
-  //   uint32.  Confusingly, this means that everything works if we make the
-  //   literal unsigned, even though we are negating it.
-  EXPECT_EQ(-2147483648u, message.repeated_int32(1));
+  EXPECT_EQ(-2147483648, message.repeated_int32(1));
 
   ASSERT_EQ(2, message.repeated_int64_size());
   EXPECT_EQ(-1, message.repeated_int64(0));
-  // Note:  In C, a negative integer literal is actually the unary negation
-  //   operator being applied to a positive integer literal, and
-  //   9223372036854775808 is outside the range of int64.  However, it is not
-  //   outside the range of uint64.  Confusingly, this means that everything
-  //   works if we make the literal unsigned, even though we are negating it.
-  EXPECT_EQ(-PROTOBUF_ULONGLONG(9223372036854775808),
-            message.repeated_int64(1));
+  EXPECT_EQ(int64_t{-9223372036854775807} - 1, message.repeated_int64(1));
 
   ASSERT_EQ(2, message.repeated_uint32_size());
   EXPECT_EQ(4294967295u, message.repeated_uint32(0));
   EXPECT_EQ(2147483648u, message.repeated_uint32(1));
 
   ASSERT_EQ(2, message.repeated_uint64_size());
-  EXPECT_EQ(PROTOBUF_ULONGLONG(18446744073709551615),
-            message.repeated_uint64(0));
-  EXPECT_EQ(PROTOBUF_ULONGLONG(9223372036854775808),
-            message.repeated_uint64(1));
+  EXPECT_EQ(uint64_t{18446744073709551615u}, message.repeated_uint64(0));
+  EXPECT_EQ(uint64_t{9223372036854775808u}, message.repeated_uint64(1));
 
   ASSERT_EQ(13, message.repeated_double_size());
   EXPECT_EQ(123.0, message.repeated_double(0));

src/google/protobuf/timestamp.pb.cc

@@ -19,7 +19,7 @@ PROTOBUF_PRAGMA_INIT_SEG
 PROTOBUF_NAMESPACE_OPEN
 constexpr Timestamp::Timestamp(
   ::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized)
-  : seconds_(PROTOBUF_LONGLONG(0))
+  : seconds_(int64_t{0})
   , nanos_(0){}
 struct TimestampDefaultTypeInternal {
   constexpr TimestampDefaultTypeInternal()
@@ -110,7 +110,7 @@ Timestamp::~Timestamp() {
 }
 
 void Timestamp::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void Timestamp::ArenaDtor(void* object) {

src/google/protobuf/timestamp.pb.h

@@ -65,7 +65,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT Timestamp PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Timestamp final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Timestamp) */ {
  public:
   inline Timestamp() : Timestamp(nullptr) {}
@@ -83,8 +83,9 @@ class PROTOBUF_EXPORT Timestamp PROTOBUF_FINAL :
     return *this;
   }
   inline Timestamp& operator=(Timestamp&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -115,7 +116,7 @@ class PROTOBUF_EXPORT Timestamp PROTOBUF_FINAL :
   }
   inline void Swap(Timestamp* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -123,14 +124,14 @@ class PROTOBUF_EXPORT Timestamp PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Timestamp* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Timestamp* New() const final {
-    return CreateMaybeMessage<Timestamp>(nullptr);
+    return new Timestamp();
   }
 
   Timestamp* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -218,7 +219,7 @@ class PROTOBUF_EXPORT Timestamp PROTOBUF_FINAL :
 
 // int64 seconds = 1;
 inline void Timestamp::clear_seconds() {
-  seconds_ = PROTOBUF_LONGLONG(0);
+  seconds_ = int64_t{0};
 }
 inline ::PROTOBUF_NAMESPACE_ID::int64 Timestamp::_internal_seconds() const {
   return seconds_;

src/google/protobuf/type.pb.cc

@@ -343,7 +343,7 @@ Type::_Internal::source_context(const Type* msg) {
   return *msg->source_context_;
 }
 void Type::clear_source_context() {
-  if (GetArena() == nullptr && source_context_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && source_context_ != nullptr) {
     delete source_context_;
   }
   source_context_ = nullptr;
@@ -366,7 +366,7 @@ Type::Type(const Type& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_source_context()) {
     source_context_ = new PROTOBUF_NAMESPACE_ID::SourceContext(*from.source_context_);
@@ -392,7 +392,7 @@ Type::~Type() {
 }
 
 void Type::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete source_context_;
 }
@@ -417,7 +417,7 @@ void Type::Clear() {
   oneofs_.Clear();
   options_.Clear();
   name_.ClearToEmpty();
-  if (GetArena() == nullptr && source_context_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && source_context_ != nullptr) {
     delete source_context_;
   }
   source_context_ = nullptr;
@@ -523,7 +523,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -612,7 +612,7 @@ size_t Type::ByteSizeLong() const {
   }
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
@@ -665,7 +665,7 @@ void Type::MergeFrom(const Type& from) {
   fields_.MergeFrom(from.fields_);
   oneofs_.MergeFrom(from.oneofs_);
   options_.MergeFrom(from.options_);
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
   if (from.has_source_context()) {
@@ -700,7 +700,11 @@ void Type::InternalSwap(Type* other) {
   fields_.InternalSwap(&other->fields_);
   oneofs_.InternalSwap(&other->oneofs_);
   options_.InternalSwap(&other->options_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(Type, syntax_)
       + sizeof(Type::syntax_)
@@ -735,22 +739,22 @@ Field::Field(const Field& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   type_url_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_type_url().empty()) {
     type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_type_url(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   json_name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_json_name().empty()) {
     json_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_json_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   default_value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_default_value().empty()) {
     default_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_default_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   ::memcpy(&kind_, &from.kind_,
     static_cast<size_t>(reinterpret_cast<char*>(&packed_) -
@@ -776,7 +780,7 @@ Field::~Field() {
 }
 
 void Field::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   type_url_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   json_name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
@@ -951,7 +955,7 @@ failure:
   }
 
   // string name = 4;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -961,7 +965,7 @@ failure:
   }
 
   // string type_url = 6;
-  if (this->type_url().size() > 0) {
+  if (!this->type_url().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_type_url().data(), static_cast<int>(this->_internal_type_url().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -991,7 +995,7 @@ failure:
   }
 
   // string json_name = 10;
-  if (this->json_name().size() > 0) {
+  if (!this->json_name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_json_name().data(), static_cast<int>(this->_internal_json_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1001,7 +1005,7 @@ failure:
   }
 
   // string default_value = 11;
-  if (this->default_value().size() > 0) {
+  if (!this->default_value().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_default_value().data(), static_cast<int>(this->_internal_default_value().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1034,28 +1038,28 @@ size_t Field::ByteSizeLong() const {
   }
 
   // string name = 4;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
   }
 
   // string type_url = 6;
-  if (this->type_url().size() > 0) {
+  if (!this->type_url().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_type_url());
   }
 
   // string json_name = 10;
-  if (this->json_name().size() > 0) {
+  if (!this->json_name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_json_name());
   }
 
   // string default_value = 11;
-  if (this->default_value().size() > 0) {
+  if (!this->default_value().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_default_value());
@@ -1124,16 +1128,16 @@ void Field::MergeFrom(const Field& from) {
   (void) cached_has_bits;
 
   options_.MergeFrom(from.options_);
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
-  if (from.type_url().size() > 0) {
+  if (!from.type_url().empty()) {
     _internal_set_type_url(from._internal_type_url());
   }
-  if (from.json_name().size() > 0) {
+  if (!from.json_name().empty()) {
     _internal_set_json_name(from._internal_json_name());
   }
-  if (from.default_value().size() > 0) {
+  if (!from.default_value().empty()) {
     _internal_set_default_value(from._internal_default_value());
   }
   if (from.kind() != 0) {
@@ -1175,10 +1179,26 @@ void Field::InternalSwap(Field* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   options_.InternalSwap(&other->options_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  type_url_.Swap(&other->type_url_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  json_name_.Swap(&other->json_name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
-  default_value_.Swap(&other->default_value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &type_url_, GetArenaForAllocation(),
+      &other->type_url_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &json_name_, GetArenaForAllocation(),
+      &other->json_name_, other->GetArenaForAllocation()
+  );
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &default_value_, GetArenaForAllocation(),
+      &other->default_value_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(Field, packed_)
       + sizeof(Field::packed_)
@@ -1205,7 +1225,7 @@ Enum::_Internal::source_context(const Enum* msg) {
   return *msg->source_context_;
 }
 void Enum::clear_source_context() {
-  if (GetArena() == nullptr && source_context_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && source_context_ != nullptr) {
     delete source_context_;
   }
   source_context_ = nullptr;
@@ -1226,7 +1246,7 @@ Enum::Enum(const Enum& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_source_context()) {
     source_context_ = new PROTOBUF_NAMESPACE_ID::SourceContext(*from.source_context_);
@@ -1252,7 +1272,7 @@ Enum::~Enum() {
 }
 
 void Enum::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete source_context_;
 }
@@ -1276,7 +1296,7 @@ void Enum::Clear() {
   enumvalue_.Clear();
   options_.Clear();
   name_.ClearToEmpty();
-  if (GetArena() == nullptr && source_context_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && source_context_ != nullptr) {
     delete source_context_;
   }
   source_context_ = nullptr;
@@ -1368,7 +1388,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1439,7 +1459,7 @@ size_t Enum::ByteSizeLong() const {
   }
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
@@ -1491,7 +1511,7 @@ void Enum::MergeFrom(const Enum& from) {
 
   enumvalue_.MergeFrom(from.enumvalue_);
   options_.MergeFrom(from.options_);
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
   if (from.has_source_context()) {
@@ -1525,7 +1545,11 @@ void Enum::InternalSwap(Enum* other) {
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   enumvalue_.InternalSwap(&other->enumvalue_);
   options_.InternalSwap(&other->options_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   ::PROTOBUF_NAMESPACE_ID::internal::memswap<
       PROTOBUF_FIELD_OFFSET(Enum, syntax_)
       + sizeof(Enum::syntax_)
@@ -1560,7 +1584,7 @@ EnumValue::EnumValue(const EnumValue& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   number_ = from.number_;
   // @@protoc_insertion_point(copy_constructor:google.protobuf.EnumValue)
@@ -1578,7 +1602,7 @@ EnumValue::~EnumValue() {
 }
 
 void EnumValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -1668,7 +1692,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1715,7 +1739,7 @@ size_t EnumValue::ByteSizeLong() const {
   }
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
@@ -1760,7 +1784,7 @@ void EnumValue::MergeFrom(const EnumValue& from) {
   (void) cached_has_bits;
 
   options_.MergeFrom(from.options_);
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
   if (from.number() != 0) {
@@ -1790,7 +1814,11 @@ void EnumValue::InternalSwap(EnumValue* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
   options_.InternalSwap(&other->options_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   swap(number_, other->number_);
 }
 
@@ -1812,7 +1840,7 @@ Option::_Internal::value(const Option* msg) {
   return *msg->value_;
 }
 void Option::clear_value() {
-  if (GetArena() == nullptr && value_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && value_ != nullptr) {
     delete value_;
   }
   value_ = nullptr;
@@ -1829,7 +1857,7 @@ Option::Option(const Option& from)
   name_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_name().empty()) {
     name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_name(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   if (from._internal_has_value()) {
     value_ = new PROTOBUF_NAMESPACE_ID::Any(*from.value_);
@@ -1851,7 +1879,7 @@ Option::~Option() {
 }
 
 void Option::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   name_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (this != internal_default_instance()) delete value_;
 }
@@ -1873,7 +1901,7 @@ void Option::Clear() {
   (void) cached_has_bits;
 
   name_.ClearToEmpty();
-  if (GetArena() == nullptr && value_ != nullptr) {
+  if (GetArenaForAllocation() == nullptr && value_ != nullptr) {
     delete value_;
   }
   value_ = nullptr;
@@ -1932,7 +1960,7 @@ failure:
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_name().data(), static_cast<int>(this->_internal_name().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1966,7 +1994,7 @@ size_t Option::ByteSizeLong() const {
   (void) cached_has_bits;
 
   // string name = 1;
-  if (this->name().size() > 0) {
+  if (!this->name().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_name());
@@ -2010,7 +2038,7 @@ void Option::MergeFrom(const Option& from) {
   ::PROTOBUF_NAMESPACE_ID::uint32 cached_has_bits = 0;
   (void) cached_has_bits;
 
-  if (from.name().size() > 0) {
+  if (!from.name().empty()) {
     _internal_set_name(from._internal_name());
   }
   if (from.has_value()) {
@@ -2039,7 +2067,11 @@ bool Option::IsInitialized() const {
 void Option::InternalSwap(Option* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
-  name_.Swap(&other->name_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &name_, GetArenaForAllocation(),
+      &other->name_, other->GetArenaForAllocation()
+  );
   swap(value_, other->value_);
 }
 

src/google/protobuf/type.pb.h

@@ -178,7 +178,7 @@ inline bool Syntax_Parse(
 }
 // ===================================================================
 
-class PROTOBUF_EXPORT Type PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Type final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Type) */ {
  public:
   inline Type() : Type(nullptr) {}
@@ -196,8 +196,9 @@ class PROTOBUF_EXPORT Type PROTOBUF_FINAL :
     return *this;
   }
   inline Type& operator=(Type&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -228,7 +229,7 @@ class PROTOBUF_EXPORT Type PROTOBUF_FINAL :
   }
   inline void Swap(Type* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -236,14 +237,14 @@ class PROTOBUF_EXPORT Type PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Type* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Type* New() const final {
-    return CreateMaybeMessage<Type>(nullptr);
+    return new Type();
   }
 
   Type* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -358,11 +359,11 @@ class PROTOBUF_EXPORT Type PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -411,7 +412,7 @@ class PROTOBUF_EXPORT Type PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Field final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Field) */ {
  public:
   inline Field() : Field(nullptr) {}
@@ -429,8 +430,9 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
     return *this;
   }
   inline Field& operator=(Field&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -461,7 +463,7 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
   }
   inline void Swap(Field* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -469,14 +471,14 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Field* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Field* New() const final {
-    return CreateMaybeMessage<Field>(nullptr);
+    return new Field();
   }
 
   Field* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -651,11 +653,11 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -665,11 +667,11 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_type_url(ArgT0&& arg0, ArgT... args);
   std::string* mutable_type_url();
-  std::string* release_type_url();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_type_url();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_type_url(const std::string& value);
   std::string* _internal_mutable_type_url();
   public:
 
@@ -679,11 +681,11 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_json_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_json_name();
-  std::string* release_json_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_json_name();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_json_name(const std::string& value);
   std::string* _internal_mutable_json_name();
   public:
 
@@ -693,11 +695,11 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_default_value(ArgT0&& arg0, ArgT... args);
   std::string* mutable_default_value();
-  std::string* release_default_value();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_default_value();
   void 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);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_default_value(const std::string& value);
   std::string* _internal_mutable_default_value();
   public:
 
@@ -768,7 +770,7 @@ class PROTOBUF_EXPORT Field PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Enum PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Enum final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Enum) */ {
  public:
   inline Enum() : Enum(nullptr) {}
@@ -786,8 +788,9 @@ class PROTOBUF_EXPORT Enum PROTOBUF_FINAL :
     return *this;
   }
   inline Enum& operator=(Enum&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -818,7 +821,7 @@ class PROTOBUF_EXPORT Enum PROTOBUF_FINAL :
   }
   inline void Swap(Enum* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -826,14 +829,14 @@ class PROTOBUF_EXPORT Enum PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Enum* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Enum* New() const final {
-    return CreateMaybeMessage<Enum>(nullptr);
+    return new Enum();
   }
 
   Enum* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -923,11 +926,11 @@ class PROTOBUF_EXPORT Enum PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -975,7 +978,7 @@ class PROTOBUF_EXPORT Enum PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT EnumValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT EnumValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.EnumValue) */ {
  public:
   inline EnumValue() : EnumValue(nullptr) {}
@@ -993,8 +996,9 @@ class PROTOBUF_EXPORT EnumValue PROTOBUF_FINAL :
     return *this;
   }
   inline EnumValue& operator=(EnumValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -1025,7 +1029,7 @@ class PROTOBUF_EXPORT EnumValue PROTOBUF_FINAL :
   }
   inline void Swap(EnumValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -1033,14 +1037,14 @@ class PROTOBUF_EXPORT EnumValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(EnumValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline EnumValue* New() const final {
-    return CreateMaybeMessage<EnumValue>(nullptr);
+    return new EnumValue();
   }
 
   EnumValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -1110,11 +1114,11 @@ class PROTOBUF_EXPORT EnumValue PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -1142,7 +1146,7 @@ class PROTOBUF_EXPORT EnumValue PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Option PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Option final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Option) */ {
  public:
   inline Option() : Option(nullptr) {}
@@ -1160,8 +1164,9 @@ class PROTOBUF_EXPORT Option PROTOBUF_FINAL :
     return *this;
   }
   inline Option& operator=(Option&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -1192,7 +1197,7 @@ class PROTOBUF_EXPORT Option PROTOBUF_FINAL :
   }
   inline void Swap(Option* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -1200,14 +1205,14 @@ class PROTOBUF_EXPORT Option PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Option* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Option* New() const final {
-    return CreateMaybeMessage<Option>(nullptr);
+    return new Option();
   }
 
   Option* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -1258,11 +1263,11 @@ class PROTOBUF_EXPORT Option PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_name(ArgT0&& arg0, ArgT... args);
   std::string* mutable_name();
-  std::string* release_name();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_name();
   void set_allocated_name(std::string* name);
   private:
   const std::string& _internal_name() const;
-  void _internal_set_name(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_name(const std::string& value);
   std::string* _internal_mutable_name();
   public:
 
@@ -1316,10 +1321,10 @@ inline const std::string& Type::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Type::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Type::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Type.name)
 }
 inline std::string* Type::mutable_name() {
@@ -1331,15 +1336,15 @@ inline const std::string& Type::_internal_name() const {
 }
 inline void Type::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Type::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Type::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Type.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Type::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -1348,7 +1353,7 @@ inline void Type::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Type.name)
 }
 
@@ -1522,7 +1527,7 @@ inline const PROTOBUF_NAMESPACE_ID::SourceContext& Type::source_context() const
 }
 inline void Type::unsafe_arena_set_allocated_source_context(
     PROTOBUF_NAMESPACE_ID::SourceContext* source_context) {
-  if (GetArena() == nullptr) {
+  if (GetArenaForAllocation() == nullptr) {
     delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context_);
   }
   source_context_ = source_context;
@@ -1537,7 +1542,7 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Type::release_source_context() {
   
   PROTOBUF_NAMESPACE_ID::SourceContext* temp = source_context_;
   source_context_ = nullptr;
-  if (GetArena() != nullptr) {
+  if (GetArenaForAllocation() != nullptr) {
     temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
   }
   return temp;
@@ -1552,7 +1557,7 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Type::unsafe_arena_release_source_c
 inline PROTOBUF_NAMESPACE_ID::SourceContext* Type::_internal_mutable_source_context() {
   
   if (source_context_ == nullptr) {
-    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::SourceContext>(GetArena());
+    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::SourceContext>(GetArenaForAllocation());
     source_context_ = p;
   }
   return source_context_;
@@ -1562,13 +1567,15 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Type::mutable_source_context() {
   return _internal_mutable_source_context();
 }
 inline void Type::set_allocated_source_context(PROTOBUF_NAMESPACE_ID::SourceContext* source_context) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   if (message_arena == nullptr) {
     delete reinterpret_cast< ::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context_);
   }
   if (source_context) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context)->GetArena();
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<
+            ::PROTOBUF_NAMESPACE_ID::MessageLite>::GetOwningArena(
+                reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context));
     if (message_arena != submessage_arena) {
       source_context = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, source_context, submessage_arena);
@@ -1674,10 +1681,10 @@ inline const std::string& Field::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Field::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Field::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Field.name)
 }
 inline std::string* Field::mutable_name() {
@@ -1689,15 +1696,15 @@ inline const std::string& Field::_internal_name() const {
 }
 inline void Field::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Field::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Field::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Field.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Field::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -1706,7 +1713,7 @@ inline void Field::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.name)
 }
 
@@ -1719,10 +1726,10 @@ inline const std::string& Field::type_url() const {
   return _internal_type_url();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Field::set_type_url(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Field::set_type_url(ArgT0&& arg0, ArgT... args) {
  
- type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Field.type_url)
 }
 inline std::string* Field::mutable_type_url() {
@@ -1734,15 +1741,15 @@ inline const std::string& Field::_internal_type_url() const {
 }
 inline void Field::_internal_set_type_url(const std::string& value) {
   
-  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  type_url_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Field::_internal_mutable_type_url() {
   
-  return type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return type_url_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Field::release_type_url() {
   // @@protoc_insertion_point(field_release:google.protobuf.Field.type_url)
-  return type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return type_url_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Field::set_allocated_type_url(std::string* type_url) {
   if (type_url != nullptr) {
@@ -1751,7 +1758,7 @@ inline void Field::set_allocated_type_url(std::string* type_url) {
     
   }
   type_url_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), type_url,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.type_url)
 }
 
@@ -1843,10 +1850,10 @@ inline const std::string& Field::json_name() const {
   return _internal_json_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Field::set_json_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Field::set_json_name(ArgT0&& arg0, ArgT... args) {
  
- json_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ json_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Field.json_name)
 }
 inline std::string* Field::mutable_json_name() {
@@ -1858,15 +1865,15 @@ inline const std::string& Field::_internal_json_name() const {
 }
 inline void Field::_internal_set_json_name(const std::string& value) {
   
-  json_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  json_name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Field::_internal_mutable_json_name() {
   
-  return json_name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return json_name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Field::release_json_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Field.json_name)
-  return json_name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return json_name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Field::set_allocated_json_name(std::string* json_name) {
   if (json_name != nullptr) {
@@ -1875,7 +1882,7 @@ inline void Field::set_allocated_json_name(std::string* json_name) {
     
   }
   json_name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), json_name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.json_name)
 }
 
@@ -1888,10 +1895,10 @@ inline const std::string& Field::default_value() const {
   return _internal_default_value();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Field::set_default_value(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Field::set_default_value(ArgT0&& arg0, ArgT... args) {
  
- default_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ default_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Field.default_value)
 }
 inline std::string* Field::mutable_default_value() {
@@ -1903,15 +1910,15 @@ inline const std::string& Field::_internal_default_value() const {
 }
 inline void Field::_internal_set_default_value(const std::string& value) {
   
-  default_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  default_value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Field::_internal_mutable_default_value() {
   
-  return default_value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return default_value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Field::release_default_value() {
   // @@protoc_insertion_point(field_release:google.protobuf.Field.default_value)
-  return default_value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return default_value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Field::set_allocated_default_value(std::string* default_value) {
   if (default_value != nullptr) {
@@ -1920,7 +1927,7 @@ inline void Field::set_allocated_default_value(std::string* default_value) {
     
   }
   default_value_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), default_value,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Field.default_value)
 }
 
@@ -1937,10 +1944,10 @@ inline const std::string& Enum::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Enum::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Enum::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Enum.name)
 }
 inline std::string* Enum::mutable_name() {
@@ -1952,15 +1959,15 @@ inline const std::string& Enum::_internal_name() const {
 }
 inline void Enum::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Enum::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Enum::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Enum.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Enum::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -1969,7 +1976,7 @@ inline void Enum::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Enum.name)
 }
 
@@ -2069,7 +2076,7 @@ inline const PROTOBUF_NAMESPACE_ID::SourceContext& Enum::source_context() const
 }
 inline void Enum::unsafe_arena_set_allocated_source_context(
     PROTOBUF_NAMESPACE_ID::SourceContext* source_context) {
-  if (GetArena() == nullptr) {
+  if (GetArenaForAllocation() == nullptr) {
     delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context_);
   }
   source_context_ = source_context;
@@ -2084,7 +2091,7 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Enum::release_source_context() {
   
   PROTOBUF_NAMESPACE_ID::SourceContext* temp = source_context_;
   source_context_ = nullptr;
-  if (GetArena() != nullptr) {
+  if (GetArenaForAllocation() != nullptr) {
     temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
   }
   return temp;
@@ -2099,7 +2106,7 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Enum::unsafe_arena_release_source_c
 inline PROTOBUF_NAMESPACE_ID::SourceContext* Enum::_internal_mutable_source_context() {
   
   if (source_context_ == nullptr) {
-    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::SourceContext>(GetArena());
+    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::SourceContext>(GetArenaForAllocation());
     source_context_ = p;
   }
   return source_context_;
@@ -2109,13 +2116,15 @@ inline PROTOBUF_NAMESPACE_ID::SourceContext* Enum::mutable_source_context() {
   return _internal_mutable_source_context();
 }
 inline void Enum::set_allocated_source_context(PROTOBUF_NAMESPACE_ID::SourceContext* source_context) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   if (message_arena == nullptr) {
     delete reinterpret_cast< ::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context_);
   }
   if (source_context) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context)->GetArena();
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<
+            ::PROTOBUF_NAMESPACE_ID::MessageLite>::GetOwningArena(
+                reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(source_context));
     if (message_arena != submessage_arena) {
       source_context = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, source_context, submessage_arena);
@@ -2161,10 +2170,10 @@ inline const std::string& EnumValue::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void EnumValue::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void EnumValue::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.EnumValue.name)
 }
 inline std::string* EnumValue::mutable_name() {
@@ -2176,15 +2185,15 @@ inline const std::string& EnumValue::_internal_name() const {
 }
 inline void EnumValue::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* EnumValue::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* EnumValue::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.EnumValue.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void EnumValue::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -2193,7 +2202,7 @@ inline void EnumValue::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.EnumValue.name)
 }
 
@@ -2269,10 +2278,10 @@ inline const std::string& Option::name() const {
   return _internal_name();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void Option::set_name(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void Option::set_name(ArgT0&& arg0, ArgT... args) {
  
- name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.Option.name)
 }
 inline std::string* Option::mutable_name() {
@@ -2284,15 +2293,15 @@ inline const std::string& Option::_internal_name() const {
 }
 inline void Option::_internal_set_name(const std::string& value) {
   
-  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  name_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* Option::_internal_mutable_name() {
   
-  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return name_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* Option::release_name() {
   // @@protoc_insertion_point(field_release:google.protobuf.Option.name)
-  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return name_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void Option::set_allocated_name(std::string* name) {
   if (name != nullptr) {
@@ -2301,7 +2310,7 @@ inline void Option::set_allocated_name(std::string* name) {
     
   }
   name_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), name,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.Option.name)
 }
 
@@ -2323,7 +2332,7 @@ inline const PROTOBUF_NAMESPACE_ID::Any& Option::value() const {
 }
 inline void Option::unsafe_arena_set_allocated_value(
     PROTOBUF_NAMESPACE_ID::Any* value) {
-  if (GetArena() == nullptr) {
+  if (GetArenaForAllocation() == nullptr) {
     delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(value_);
   }
   value_ = value;
@@ -2338,7 +2347,7 @@ inline PROTOBUF_NAMESPACE_ID::Any* Option::release_value() {
   
   PROTOBUF_NAMESPACE_ID::Any* temp = value_;
   value_ = nullptr;
-  if (GetArena() != nullptr) {
+  if (GetArenaForAllocation() != nullptr) {
     temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
   }
   return temp;
@@ -2353,7 +2362,7 @@ inline PROTOBUF_NAMESPACE_ID::Any* Option::unsafe_arena_release_value() {
 inline PROTOBUF_NAMESPACE_ID::Any* Option::_internal_mutable_value() {
   
   if (value_ == nullptr) {
-    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::Any>(GetArena());
+    auto* p = CreateMaybeMessage<PROTOBUF_NAMESPACE_ID::Any>(GetArenaForAllocation());
     value_ = p;
   }
   return value_;
@@ -2363,13 +2372,15 @@ inline PROTOBUF_NAMESPACE_ID::Any* Option::mutable_value() {
   return _internal_mutable_value();
 }
 inline void Option::set_allocated_value(PROTOBUF_NAMESPACE_ID::Any* value) {
-  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArena();
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
   if (message_arena == nullptr) {
     delete reinterpret_cast< ::PROTOBUF_NAMESPACE_ID::MessageLite*>(value_);
   }
   if (value) {
     ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
-      reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(value)->GetArena();
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper<
+            ::PROTOBUF_NAMESPACE_ID::MessageLite>::GetOwningArena(
+                reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(value));
     if (message_arena != submessage_arena) {
       value = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
           message_arena, value, submessage_arena);

src/google/protobuf/util/internal/protostream_objectwriter.cc

@@ -1238,6 +1238,19 @@ ProtoStreamObjectWriter* ProtoStreamObjectWriter::RenderDataPiece(
     return this;
   }
 
+  if (IsRepeated(*field) && !current_->is_list()) {
+    if (options_.disable_implicit_scalar_list) {
+      if (!options_.suppress_implicit_scalar_list_error) {
+        InvalidValue(
+            field->name(),
+            "Starting an primitive in a repeated field but the parent field "
+            "is not a list");
+      }
+
+      return this;
+    }
+  }
+
   ProtoWriter::RenderDataPiece(name, data);
   return this;
 }

src/google/protobuf/util/internal/protostream_objectwriter.h

@@ -108,6 +108,13 @@ class PROTOBUF_EXPORT ProtoStreamObjectWriter : public ProtoWriter {
     // is disabled.
     bool suppress_implicit_message_list_error;
 
+    // If true, disable implicitly creating scalar list.
+    bool disable_implicit_scalar_list;
+
+    // If true, suppress the error of implicitly creating scalar list when it
+    // is disabled.
+    bool suppress_implicit_scalar_list_error;
+
     // If true, suppress the error of rendering scalar field if the source is an
     // object.
     bool suppress_object_to_scalar_error;
@@ -125,6 +132,8 @@ class PROTOBUF_EXPORT ProtoStreamObjectWriter : public ProtoWriter {
           use_legacy_json_map_format(false),
           disable_implicit_message_list(false),
           suppress_implicit_message_list_error(false),
+          disable_implicit_scalar_list(false),
+          suppress_implicit_scalar_list_error(false),
           suppress_object_to_scalar_error(false),
           use_json_name_in_missing_fields(false) {}
 

src/google/protobuf/wire_format_unittest.cc

@@ -811,8 +811,8 @@ TEST(WireFormatTest, UnknownFieldRecursionLimit) {
 
 TEST(WireFormatTest, ZigZag) {
 // avoid line-wrapping
-#define LL(x) PROTOBUF_LONGLONG(x)
-#define ULL(x) PROTOBUF_ULONGLONG(x)
+#define LL(x) static_cast<int64_t>(ULL(x))
+#define ULL(x) uint64_t{x##u}
 #define ZigZagEncode32(x) WireFormatLite::ZigZagEncode32(x)
 #define ZigZagDecode32(x) WireFormatLite::ZigZagDecode32(x)
 #define ZigZagEncode64(x) WireFormatLite::ZigZagEncode64(x)

src/google/protobuf/wrappers.pb.cc

@@ -43,7 +43,7 @@ struct FloatValueDefaultTypeInternal {
 PROTOBUF_ATTRIBUTE_NO_DESTROY PROTOBUF_CONSTINIT FloatValueDefaultTypeInternal _FloatValue_default_instance_;
 constexpr Int64Value::Int64Value(
   ::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized)
-  : value_(PROTOBUF_LONGLONG(0)){}
+  : value_(int64_t{0}){}
 struct Int64ValueDefaultTypeInternal {
   constexpr Int64ValueDefaultTypeInternal()
     : _instance(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized{}) {}
@@ -55,7 +55,7 @@ struct Int64ValueDefaultTypeInternal {
 PROTOBUF_ATTRIBUTE_NO_DESTROY PROTOBUF_CONSTINIT Int64ValueDefaultTypeInternal _Int64Value_default_instance_;
 constexpr UInt64Value::UInt64Value(
   ::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized)
-  : value_(PROTOBUF_ULONGLONG(0)){}
+  : value_(uint64_t{0u}){}
 struct UInt64ValueDefaultTypeInternal {
   constexpr UInt64ValueDefaultTypeInternal()
     : _instance(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized{}) {}
@@ -269,7 +269,7 @@ DoubleValue::~DoubleValue() {
 }
 
 void DoubleValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void DoubleValue::ArenaDtor(void* object) {
@@ -457,7 +457,7 @@ FloatValue::~FloatValue() {
 }
 
 void FloatValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void FloatValue::ArenaDtor(void* object) {
@@ -635,7 +635,7 @@ Int64Value::Int64Value(const Int64Value& from)
 }
 
 void Int64Value::SharedCtor() {
-value_ = PROTOBUF_LONGLONG(0);
+value_ = int64_t{0};
 }
 
 Int64Value::~Int64Value() {
@@ -645,7 +645,7 @@ Int64Value::~Int64Value() {
 }
 
 void Int64Value::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void Int64Value::ArenaDtor(void* object) {
@@ -664,7 +664,7 @@ void Int64Value::Clear() {
   // Prevent compiler warnings about cached_has_bits being unused
   (void) cached_has_bits;
 
-  value_ = PROTOBUF_LONGLONG(0);
+  value_ = int64_t{0};
   _internal_metadata_.Clear<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>();
 }
 
@@ -825,7 +825,7 @@ UInt64Value::UInt64Value(const UInt64Value& from)
 }
 
 void UInt64Value::SharedCtor() {
-value_ = PROTOBUF_ULONGLONG(0);
+value_ = uint64_t{0u};
 }
 
 UInt64Value::~UInt64Value() {
@@ -835,7 +835,7 @@ UInt64Value::~UInt64Value() {
 }
 
 void UInt64Value::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void UInt64Value::ArenaDtor(void* object) {
@@ -854,7 +854,7 @@ void UInt64Value::Clear() {
   // Prevent compiler warnings about cached_has_bits being unused
   (void) cached_has_bits;
 
-  value_ = PROTOBUF_ULONGLONG(0);
+  value_ = uint64_t{0u};
   _internal_metadata_.Clear<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>();
 }
 
@@ -1025,7 +1025,7 @@ Int32Value::~Int32Value() {
 }
 
 void Int32Value::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void Int32Value::ArenaDtor(void* object) {
@@ -1215,7 +1215,7 @@ UInt32Value::~UInt32Value() {
 }
 
 void UInt32Value::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void UInt32Value::ArenaDtor(void* object) {
@@ -1405,7 +1405,7 @@ BoolValue::~BoolValue() {
 }
 
 void BoolValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
 }
 
 void BoolValue::ArenaDtor(void* object) {
@@ -1581,7 +1581,7 @@ StringValue::StringValue(const StringValue& from)
   value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_value().empty()) {
     value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   // @@protoc_insertion_point(copy_constructor:google.protobuf.StringValue)
 }
@@ -1597,7 +1597,7 @@ StringValue::~StringValue() {
 }
 
 void StringValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   value_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -1666,7 +1666,7 @@ failure:
   (void) cached_has_bits;
 
   // string value = 1;
-  if (this->value().size() > 0) {
+  if (!this->value().empty()) {
     ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::VerifyUtf8String(
       this->_internal_value().data(), static_cast<int>(this->_internal_value().length()),
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::SERIALIZE,
@@ -1692,7 +1692,7 @@ size_t StringValue::ByteSizeLong() const {
   (void) cached_has_bits;
 
   // string value = 1;
-  if (this->value().size() > 0) {
+  if (!this->value().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::StringSize(
         this->_internal_value());
@@ -1729,7 +1729,7 @@ void StringValue::MergeFrom(const StringValue& from) {
   ::PROTOBUF_NAMESPACE_ID::uint32 cached_has_bits = 0;
   (void) cached_has_bits;
 
-  if (from.value().size() > 0) {
+  if (!from.value().empty()) {
     _internal_set_value(from._internal_value());
   }
 }
@@ -1755,7 +1755,11 @@ bool StringValue::IsInitialized() const {
 void StringValue::InternalSwap(StringValue* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
-  value_.Swap(&other->value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &value_, GetArenaForAllocation(),
+      &other->value_, other->GetArenaForAllocation()
+  );
 }
 
 ::PROTOBUF_NAMESPACE_ID::Metadata StringValue::GetMetadata() const {
@@ -1782,7 +1786,7 @@ BytesValue::BytesValue(const BytesValue& from)
   value_.UnsafeSetDefault(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
   if (!from._internal_value().empty()) {
     value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, from._internal_value(), 
-      GetArena());
+      GetArenaForAllocation());
   }
   // @@protoc_insertion_point(copy_constructor:google.protobuf.BytesValue)
 }
@@ -1798,7 +1802,7 @@ BytesValue::~BytesValue() {
 }
 
 void BytesValue::SharedDtor() {
-  GOOGLE_DCHECK(GetArena() == nullptr);
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   value_.DestroyNoArena(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited());
 }
 
@@ -1866,7 +1870,7 @@ failure:
   (void) cached_has_bits;
 
   // bytes value = 1;
-  if (this->value().size() > 0) {
+  if (!this->value().empty()) {
     target = stream->WriteBytesMaybeAliased(
         1, this->_internal_value(), target);
   }
@@ -1888,7 +1892,7 @@ size_t BytesValue::ByteSizeLong() const {
   (void) cached_has_bits;
 
   // bytes value = 1;
-  if (this->value().size() > 0) {
+  if (!this->value().empty()) {
     total_size += 1 +
       ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::BytesSize(
         this->_internal_value());
@@ -1925,7 +1929,7 @@ void BytesValue::MergeFrom(const BytesValue& from) {
   ::PROTOBUF_NAMESPACE_ID::uint32 cached_has_bits = 0;
   (void) cached_has_bits;
 
-  if (from.value().size() > 0) {
+  if (!from.value().empty()) {
     _internal_set_value(from._internal_value());
   }
 }
@@ -1951,7 +1955,11 @@ bool BytesValue::IsInitialized() const {
 void BytesValue::InternalSwap(BytesValue* other) {
   using std::swap;
   _internal_metadata_.InternalSwap(&other->_internal_metadata_);
-  value_.Swap(&other->value_, &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  ::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::InternalSwap(
+      &::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(),
+      &value_, GetArenaForAllocation(),
+      &other->value_, other->GetArenaForAllocation()
+  );
 }
 
 ::PROTOBUF_NAMESPACE_ID::Metadata BytesValue::GetMetadata() const {

src/google/protobuf/wrappers.pb.h

@@ -97,7 +97,7 @@ PROTOBUF_NAMESPACE_OPEN
 
 // ===================================================================
 
-class PROTOBUF_EXPORT DoubleValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT DoubleValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.DoubleValue) */ {
  public:
   inline DoubleValue() : DoubleValue(nullptr) {}
@@ -115,8 +115,9 @@ class PROTOBUF_EXPORT DoubleValue PROTOBUF_FINAL :
     return *this;
   }
   inline DoubleValue& operator=(DoubleValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -147,7 +148,7 @@ class PROTOBUF_EXPORT DoubleValue PROTOBUF_FINAL :
   }
   inline void Swap(DoubleValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -155,14 +156,14 @@ class PROTOBUF_EXPORT DoubleValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(DoubleValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline DoubleValue* New() const final {
-    return CreateMaybeMessage<DoubleValue>(nullptr);
+    return new DoubleValue();
   }
 
   DoubleValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -228,7 +229,7 @@ class PROTOBUF_EXPORT DoubleValue PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT FloatValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT FloatValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.FloatValue) */ {
  public:
   inline FloatValue() : FloatValue(nullptr) {}
@@ -246,8 +247,9 @@ class PROTOBUF_EXPORT FloatValue PROTOBUF_FINAL :
     return *this;
   }
   inline FloatValue& operator=(FloatValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -278,7 +280,7 @@ class PROTOBUF_EXPORT FloatValue PROTOBUF_FINAL :
   }
   inline void Swap(FloatValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -286,14 +288,14 @@ class PROTOBUF_EXPORT FloatValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(FloatValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline FloatValue* New() const final {
-    return CreateMaybeMessage<FloatValue>(nullptr);
+    return new FloatValue();
   }
 
   FloatValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -359,7 +361,7 @@ class PROTOBUF_EXPORT FloatValue PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Int64Value PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Int64Value final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Int64Value) */ {
  public:
   inline Int64Value() : Int64Value(nullptr) {}
@@ -377,8 +379,9 @@ class PROTOBUF_EXPORT Int64Value PROTOBUF_FINAL :
     return *this;
   }
   inline Int64Value& operator=(Int64Value&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -409,7 +412,7 @@ class PROTOBUF_EXPORT Int64Value PROTOBUF_FINAL :
   }
   inline void Swap(Int64Value* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -417,14 +420,14 @@ class PROTOBUF_EXPORT Int64Value PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Int64Value* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Int64Value* New() const final {
-    return CreateMaybeMessage<Int64Value>(nullptr);
+    return new Int64Value();
   }
 
   Int64Value* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -490,7 +493,7 @@ class PROTOBUF_EXPORT Int64Value PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT UInt64Value PROTOBUF_FINAL :
+class PROTOBUF_EXPORT UInt64Value final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.UInt64Value) */ {
  public:
   inline UInt64Value() : UInt64Value(nullptr) {}
@@ -508,8 +511,9 @@ class PROTOBUF_EXPORT UInt64Value PROTOBUF_FINAL :
     return *this;
   }
   inline UInt64Value& operator=(UInt64Value&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -540,7 +544,7 @@ class PROTOBUF_EXPORT UInt64Value PROTOBUF_FINAL :
   }
   inline void Swap(UInt64Value* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -548,14 +552,14 @@ class PROTOBUF_EXPORT UInt64Value PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(UInt64Value* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline UInt64Value* New() const final {
-    return CreateMaybeMessage<UInt64Value>(nullptr);
+    return new UInt64Value();
   }
 
   UInt64Value* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -621,7 +625,7 @@ class PROTOBUF_EXPORT UInt64Value PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT Int32Value PROTOBUF_FINAL :
+class PROTOBUF_EXPORT Int32Value final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.Int32Value) */ {
  public:
   inline Int32Value() : Int32Value(nullptr) {}
@@ -639,8 +643,9 @@ class PROTOBUF_EXPORT Int32Value PROTOBUF_FINAL :
     return *this;
   }
   inline Int32Value& operator=(Int32Value&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -671,7 +676,7 @@ class PROTOBUF_EXPORT Int32Value PROTOBUF_FINAL :
   }
   inline void Swap(Int32Value* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -679,14 +684,14 @@ class PROTOBUF_EXPORT Int32Value PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(Int32Value* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline Int32Value* New() const final {
-    return CreateMaybeMessage<Int32Value>(nullptr);
+    return new Int32Value();
   }
 
   Int32Value* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -752,7 +757,7 @@ class PROTOBUF_EXPORT Int32Value PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT UInt32Value PROTOBUF_FINAL :
+class PROTOBUF_EXPORT UInt32Value final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.UInt32Value) */ {
  public:
   inline UInt32Value() : UInt32Value(nullptr) {}
@@ -770,8 +775,9 @@ class PROTOBUF_EXPORT UInt32Value PROTOBUF_FINAL :
     return *this;
   }
   inline UInt32Value& operator=(UInt32Value&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -802,7 +808,7 @@ class PROTOBUF_EXPORT UInt32Value PROTOBUF_FINAL :
   }
   inline void Swap(UInt32Value* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -810,14 +816,14 @@ class PROTOBUF_EXPORT UInt32Value PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(UInt32Value* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline UInt32Value* New() const final {
-    return CreateMaybeMessage<UInt32Value>(nullptr);
+    return new UInt32Value();
   }
 
   UInt32Value* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -883,7 +889,7 @@ class PROTOBUF_EXPORT UInt32Value PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT BoolValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT BoolValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.BoolValue) */ {
  public:
   inline BoolValue() : BoolValue(nullptr) {}
@@ -901,8 +907,9 @@ class PROTOBUF_EXPORT BoolValue PROTOBUF_FINAL :
     return *this;
   }
   inline BoolValue& operator=(BoolValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -933,7 +940,7 @@ class PROTOBUF_EXPORT BoolValue PROTOBUF_FINAL :
   }
   inline void Swap(BoolValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -941,14 +948,14 @@ class PROTOBUF_EXPORT BoolValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(BoolValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline BoolValue* New() const final {
-    return CreateMaybeMessage<BoolValue>(nullptr);
+    return new BoolValue();
   }
 
   BoolValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -1014,7 +1021,7 @@ class PROTOBUF_EXPORT BoolValue PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT StringValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT StringValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.StringValue) */ {
  public:
   inline StringValue() : StringValue(nullptr) {}
@@ -1032,8 +1039,9 @@ class PROTOBUF_EXPORT StringValue PROTOBUF_FINAL :
     return *this;
   }
   inline StringValue& operator=(StringValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -1064,7 +1072,7 @@ class PROTOBUF_EXPORT StringValue PROTOBUF_FINAL :
   }
   inline void Swap(StringValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -1072,14 +1080,14 @@ class PROTOBUF_EXPORT StringValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(StringValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline StringValue* New() const final {
-    return CreateMaybeMessage<StringValue>(nullptr);
+    return new StringValue();
   }
 
   StringValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -1129,11 +1137,11 @@ class PROTOBUF_EXPORT StringValue PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_value(ArgT0&& arg0, ArgT... args);
   std::string* mutable_value();
-  std::string* release_value();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_value();
   void set_allocated_value(std::string* value);
   private:
   const std::string& _internal_value() const;
-  void _internal_set_value(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_value(const std::string& value);
   std::string* _internal_mutable_value();
   public:
 
@@ -1150,7 +1158,7 @@ class PROTOBUF_EXPORT StringValue PROTOBUF_FINAL :
 };
 // -------------------------------------------------------------------
 
-class PROTOBUF_EXPORT BytesValue PROTOBUF_FINAL :
+class PROTOBUF_EXPORT BytesValue final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:google.protobuf.BytesValue) */ {
  public:
   inline BytesValue() : BytesValue(nullptr) {}
@@ -1168,8 +1176,9 @@ class PROTOBUF_EXPORT BytesValue PROTOBUF_FINAL :
     return *this;
   }
   inline BytesValue& operator=(BytesValue&& from) noexcept {
-    if (GetArena() == from.GetArena()) {
-      if (this != &from) InternalSwap(&from);
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()) {
+      InternalSwap(&from);
     } else {
       CopyFrom(from);
     }
@@ -1200,7 +1209,7 @@ class PROTOBUF_EXPORT BytesValue PROTOBUF_FINAL :
   }
   inline void Swap(BytesValue* other) {
     if (other == this) return;
-    if (GetArena() == other->GetArena()) {
+    if (GetOwningArena() == other->GetOwningArena()) {
       InternalSwap(other);
     } else {
       ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
@@ -1208,14 +1217,14 @@ class PROTOBUF_EXPORT BytesValue PROTOBUF_FINAL :
   }
   void UnsafeArenaSwap(BytesValue* other) {
     if (other == this) return;
-    GOOGLE_DCHECK(GetArena() == other->GetArena());
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
     InternalSwap(other);
   }
 
   // implements Message ----------------------------------------------
 
   inline BytesValue* New() const final {
-    return CreateMaybeMessage<BytesValue>(nullptr);
+    return new BytesValue();
   }
 
   BytesValue* New(::PROTOBUF_NAMESPACE_ID::Arena* arena) const final {
@@ -1265,11 +1274,11 @@ class PROTOBUF_EXPORT BytesValue PROTOBUF_FINAL :
   template <typename ArgT0 = const std::string&, typename... ArgT>
   void set_value(ArgT0&& arg0, ArgT... args);
   std::string* mutable_value();
-  std::string* release_value();
+  PROTOBUF_FUTURE_MUST_USE_RESULT std::string* release_value();
   void set_allocated_value(std::string* value);
   private:
   const std::string& _internal_value() const;
-  void _internal_set_value(const std::string& value);
+  inline PROTOBUF_ALWAYS_INLINE void _internal_set_value(const std::string& value);
   std::string* _internal_mutable_value();
   public:
 
@@ -1345,7 +1354,7 @@ inline void FloatValue::set_value(float value) {
 
 // int64 value = 1;
 inline void Int64Value::clear_value() {
-  value_ = PROTOBUF_LONGLONG(0);
+  value_ = int64_t{0};
 }
 inline ::PROTOBUF_NAMESPACE_ID::int64 Int64Value::_internal_value() const {
   return value_;
@@ -1369,7 +1378,7 @@ inline void Int64Value::set_value(::PROTOBUF_NAMESPACE_ID::int64 value) {
 
 // uint64 value = 1;
 inline void UInt64Value::clear_value() {
-  value_ = PROTOBUF_ULONGLONG(0);
+  value_ = uint64_t{0u};
 }
 inline ::PROTOBUF_NAMESPACE_ID::uint64 UInt64Value::_internal_value() const {
   return value_;
@@ -1472,10 +1481,10 @@ inline const std::string& StringValue::value() const {
   return _internal_value();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void StringValue::set_value(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void StringValue::set_value(ArgT0&& arg0, ArgT... args) {
  
- value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.StringValue.value)
 }
 inline std::string* StringValue::mutable_value() {
@@ -1487,15 +1496,15 @@ inline const std::string& StringValue::_internal_value() const {
 }
 inline void StringValue::_internal_set_value(const std::string& value) {
   
-  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* StringValue::_internal_mutable_value() {
   
-  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* StringValue::release_value() {
   // @@protoc_insertion_point(field_release:google.protobuf.StringValue.value)
-  return value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void StringValue::set_allocated_value(std::string* value) {
   if (value != nullptr) {
@@ -1504,7 +1513,7 @@ inline void StringValue::set_allocated_value(std::string* value) {
     
   }
   value_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), value,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.StringValue.value)
 }
 
@@ -1521,10 +1530,10 @@ inline const std::string& BytesValue::value() const {
   return _internal_value();
 }
 template <typename ArgT0, typename... ArgT>
-PROTOBUF_ALWAYS_INLINE
-inline void BytesValue::set_value(ArgT0&& arg0, ArgT... args) {
+inline PROTOBUF_ALWAYS_INLINE
+void BytesValue::set_value(ArgT0&& arg0, ArgT... args) {
  
- value_.SetBytes(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArena());
+ value_.SetBytes(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, static_cast<ArgT0 &&>(arg0), args..., GetArenaForAllocation());
   // @@protoc_insertion_point(field_set:google.protobuf.BytesValue.value)
 }
 inline std::string* BytesValue::mutable_value() {
@@ -1536,15 +1545,15 @@ inline const std::string& BytesValue::_internal_value() const {
 }
 inline void BytesValue::_internal_set_value(const std::string& value) {
   
-  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArena());
+  value_.Set(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, value, GetArenaForAllocation());
 }
 inline std::string* BytesValue::_internal_mutable_value() {
   
-  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArena());
+  return value_.Mutable(::PROTOBUF_NAMESPACE_ID::internal::ArenaStringPtr::EmptyDefault{}, GetArenaForAllocation());
 }
 inline std::string* BytesValue::release_value() {
   // @@protoc_insertion_point(field_release:google.protobuf.BytesValue.value)
-  return value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArena());
+  return value_.Release(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), GetArenaForAllocation());
 }
 inline void BytesValue::set_allocated_value(std::string* value) {
   if (value != nullptr) {
@@ -1553,7 +1562,7 @@ inline void BytesValue::set_allocated_value(std::string* value) {
     
   }
   value_.SetAllocated(&::PROTOBUF_NAMESPACE_ID::internal::GetEmptyStringAlreadyInited(), value,
-      GetArena());
+      GetArenaForAllocation());
   // @@protoc_insertion_point(field_set_allocated:google.protobuf.BytesValue.value)
 }