From 1f0da1ba118addb60c471c6a1ee26671846e4d3f Mon Sep 17 00:00:00 2001
From: Chris Kennelly <ckennelly@google.com>
Date: Fri, 12 May 2023 12:03:16 -0700
Subject: [PATCH] Remove vestigal check for non-nullptr Arenas.

When we are running the destructor, we do not have an Arena.  Since the Arena
is a runtime property, the compiler may not be able to optimize it out.

PiperOrigin-RevId: 531568752
---
 src/google/protobuf/compiler/cpp/message.cc |  12 +-
 src/google/protobuf/compiler/plugin.pb.cc   |  24 +--
 src/google/protobuf/descriptor.pb.cc        | 168 ++++----------------
 3 files changed, 33 insertions(+), 171 deletions(-)

diff --git a/src/google/protobuf/compiler/cpp/message.cc b/src/google/protobuf/compiler/cpp/message.cc
index c8f5dfe487..949c31ce06 100644
--- a/src/google/protobuf/compiler/cpp/message.cc
+++ b/src/google/protobuf/compiler/cpp/message.cc
@@ -2896,20 +2896,10 @@ void MessageGenerator::GenerateStructors(io::Printer* p) {
     // or extensions)
   } else {
     p->Emit(
-        {{"arena_dtor",
-          [&] {
-            if (NeedsArenaDestructor() == ArenaDtorNeeds::kNone) return;
-            p->Emit("ArenaDtor(this);");
-          }}},
         R"cc(
           $classname$::~$classname$() {
             // @@protoc_insertion_point(destructor:$full_name$)
-            if (auto *arena = _internal_metadata_
-                                  .DeleteReturnArena<$unknown_fields_type$>()) {
-              (void)arena;
-              $arena_dtor$;
-              return;
-            }
+            _internal_metadata_.DeleteReturnArena<$unknown_fields_type$>();
             SharedDtor();
           }
         )cc");
diff --git a/src/google/protobuf/compiler/plugin.pb.cc b/src/google/protobuf/compiler/plugin.pb.cc
index b7f17a8e6a..b08dd41995 100644
--- a/src/google/protobuf/compiler/plugin.pb.cc
+++ b/src/google/protobuf/compiler/plugin.pb.cc
@@ -361,11 +361,7 @@ inline void Version::SharedCtor(::_pb::Arena* arena) {
 }
 Version::~Version() {
   // @@protoc_insertion_point(destructor:google.protobuf.compiler.Version)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void Version::SharedDtor() {
@@ -672,11 +668,7 @@ inline void CodeGeneratorRequest::SharedCtor(::_pb::Arena* arena) {
 }
 CodeGeneratorRequest::~CodeGeneratorRequest() {
   // @@protoc_insertion_point(destructor:google.protobuf.compiler.CodeGeneratorRequest)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void CodeGeneratorRequest::SharedDtor() {
@@ -1025,11 +1017,7 @@ inline void CodeGeneratorResponse_File::SharedCtor(::_pb::Arena* arena) {
 }
 CodeGeneratorResponse_File::~CodeGeneratorResponse_File() {
   // @@protoc_insertion_point(destructor:google.protobuf.compiler.CodeGeneratorResponse.File)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void CodeGeneratorResponse_File::SharedDtor() {
@@ -1339,11 +1327,7 @@ inline void CodeGeneratorResponse::SharedCtor(::_pb::Arena* arena) {
 }
 CodeGeneratorResponse::~CodeGeneratorResponse() {
   // @@protoc_insertion_point(destructor:google.protobuf.compiler.CodeGeneratorResponse)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void CodeGeneratorResponse::SharedDtor() {
diff --git a/src/google/protobuf/descriptor.pb.cc b/src/google/protobuf/descriptor.pb.cc
index 79dc662ba7..4454c4741f 100644
--- a/src/google/protobuf/descriptor.pb.cc
+++ b/src/google/protobuf/descriptor.pb.cc
@@ -2013,11 +2013,7 @@ inline void FileDescriptorSet::SharedCtor(::_pb::Arena* arena) {
 }
 FileDescriptorSet::~FileDescriptorSet() {
   // @@protoc_insertion_point(destructor:google.protobuf.FileDescriptorSet)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void FileDescriptorSet::SharedDtor() {
@@ -2295,11 +2291,7 @@ inline void FileDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 FileDescriptorProto::~FileDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.FileDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void FileDescriptorProto::SharedDtor() {
@@ -2875,11 +2867,7 @@ inline void DescriptorProto_ExtensionRange::SharedCtor(::_pb::Arena* arena) {
 }
 DescriptorProto_ExtensionRange::~DescriptorProto_ExtensionRange() {
   // @@protoc_insertion_point(destructor:google.protobuf.DescriptorProto.ExtensionRange)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void DescriptorProto_ExtensionRange::SharedDtor() {
@@ -3129,11 +3117,7 @@ inline void DescriptorProto_ReservedRange::SharedCtor(::_pb::Arena* arena) {
 }
 DescriptorProto_ReservedRange::~DescriptorProto_ReservedRange() {
   // @@protoc_insertion_point(destructor:google.protobuf.DescriptorProto.ReservedRange)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void DescriptorProto_ReservedRange::SharedDtor() {
@@ -3392,11 +3376,7 @@ inline void DescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 DescriptorProto::~DescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.DescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void DescriptorProto::SharedDtor() {
@@ -3906,11 +3886,7 @@ inline void ExtensionRangeOptions_Declaration::SharedCtor(::_pb::Arena* arena) {
 }
 ExtensionRangeOptions_Declaration::~ExtensionRangeOptions_Declaration() {
   // @@protoc_insertion_point(destructor:google.protobuf.ExtensionRangeOptions.Declaration)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void ExtensionRangeOptions_Declaration::SharedDtor() {
@@ -4248,11 +4224,7 @@ inline void ExtensionRangeOptions::SharedCtor(::_pb::Arena* arena) {
 }
 ExtensionRangeOptions::~ExtensionRangeOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.ExtensionRangeOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void ExtensionRangeOptions::SharedDtor() {
@@ -4616,11 +4588,7 @@ inline void FieldDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 FieldDescriptorProto::~FieldDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.FieldDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void FieldDescriptorProto::SharedDtor() {
@@ -5131,11 +5099,7 @@ inline void OneofDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 OneofDescriptorProto::~OneofDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.OneofDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void OneofDescriptorProto::SharedDtor() {
@@ -5365,11 +5329,7 @@ inline void EnumDescriptorProto_EnumReservedRange::SharedCtor(::_pb::Arena* aren
 }
 EnumDescriptorProto_EnumReservedRange::~EnumDescriptorProto_EnumReservedRange() {
   // @@protoc_insertion_point(destructor:google.protobuf.EnumDescriptorProto.EnumReservedRange)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void EnumDescriptorProto_EnumReservedRange::SharedDtor() {
@@ -5618,11 +5578,7 @@ inline void EnumDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 EnumDescriptorProto::~EnumDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.EnumDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void EnumDescriptorProto::SharedDtor() {
@@ -5968,11 +5924,7 @@ inline void EnumValueDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 EnumValueDescriptorProto::~EnumValueDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.EnumValueDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void EnumValueDescriptorProto::SharedDtor() {
@@ -6260,11 +6212,7 @@ inline void ServiceDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 ServiceDescriptorProto::~ServiceDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.ServiceDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void ServiceDescriptorProto::SharedDtor() {
@@ -6594,11 +6542,7 @@ inline void MethodDescriptorProto::SharedCtor(::_pb::Arena* arena) {
 }
 MethodDescriptorProto::~MethodDescriptorProto() {
   // @@protoc_insertion_point(destructor:google.protobuf.MethodDescriptorProto)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void MethodDescriptorProto::SharedDtor() {
@@ -7158,11 +7102,7 @@ inline void FileOptions::SharedCtor(::_pb::Arena* arena) {
 }
 FileOptions::~FileOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.FileOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void FileOptions::SharedDtor() {
@@ -7952,11 +7892,7 @@ inline void MessageOptions::SharedCtor(::_pb::Arena* arena) {
 }
 MessageOptions::~MessageOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.MessageOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void MessageOptions::SharedDtor() {
@@ -8334,11 +8270,7 @@ inline void FieldOptions::SharedCtor(::_pb::Arena* arena) {
 }
 FieldOptions::~FieldOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.FieldOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void FieldOptions::SharedDtor() {
@@ -8812,11 +8744,7 @@ inline void OneofOptions::SharedCtor(::_pb::Arena* arena) {
 }
 OneofOptions::~OneofOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.OneofOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void OneofOptions::SharedDtor() {
@@ -9032,11 +8960,7 @@ inline void EnumOptions::SharedCtor(::_pb::Arena* arena) {
 }
 EnumOptions::~EnumOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.EnumOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void EnumOptions::SharedDtor() {
@@ -9326,11 +9250,7 @@ inline void EnumValueOptions::SharedCtor(::_pb::Arena* arena) {
 }
 EnumValueOptions::~EnumValueOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.EnumValueOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void EnumValueOptions::SharedDtor() {
@@ -9563,11 +9483,7 @@ inline void ServiceOptions::SharedCtor(::_pb::Arena* arena) {
 }
 ServiceOptions::~ServiceOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.ServiceOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void ServiceOptions::SharedDtor() {
@@ -9808,11 +9724,7 @@ inline void MethodOptions::SharedCtor(::_pb::Arena* arena) {
 }
 MethodOptions::~MethodOptions() {
   // @@protoc_insertion_point(destructor:google.protobuf.MethodOptions)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void MethodOptions::SharedDtor() {
@@ -10097,11 +10009,7 @@ inline void UninterpretedOption_NamePart::SharedCtor(::_pb::Arena* arena) {
 }
 UninterpretedOption_NamePart::~UninterpretedOption_NamePart() {
   // @@protoc_insertion_point(destructor:google.protobuf.UninterpretedOption.NamePart)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void UninterpretedOption_NamePart::SharedDtor() {
@@ -10401,11 +10309,7 @@ inline void UninterpretedOption::SharedCtor(::_pb::Arena* arena) {
 }
 UninterpretedOption::~UninterpretedOption() {
   // @@protoc_insertion_point(destructor:google.protobuf.UninterpretedOption)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void UninterpretedOption::SharedDtor() {
@@ -10804,11 +10708,7 @@ inline void SourceCodeInfo_Location::SharedCtor(::_pb::Arena* arena) {
 }
 SourceCodeInfo_Location::~SourceCodeInfo_Location() {
   // @@protoc_insertion_point(destructor:google.protobuf.SourceCodeInfo.Location)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void SourceCodeInfo_Location::SharedDtor() {
@@ -11126,11 +11026,7 @@ inline void SourceCodeInfo::SharedCtor(::_pb::Arena* arena) {
 }
 SourceCodeInfo::~SourceCodeInfo() {
   // @@protoc_insertion_point(destructor:google.protobuf.SourceCodeInfo)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void SourceCodeInfo::SharedDtor() {
@@ -11342,11 +11238,7 @@ inline void GeneratedCodeInfo_Annotation::SharedCtor(::_pb::Arena* arena) {
 }
 GeneratedCodeInfo_Annotation::~GeneratedCodeInfo_Annotation() {
   // @@protoc_insertion_point(destructor:google.protobuf.GeneratedCodeInfo.Annotation)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void GeneratedCodeInfo_Annotation::SharedDtor() {
@@ -11650,11 +11542,7 @@ inline void GeneratedCodeInfo::SharedCtor(::_pb::Arena* arena) {
 }
 GeneratedCodeInfo::~GeneratedCodeInfo() {
   // @@protoc_insertion_point(destructor:google.protobuf.GeneratedCodeInfo)
-  if (auto *arena = _internal_metadata_
-                        .DeleteReturnArena<::google::protobuf::UnknownFieldSet>()) {
-    (void)arena;
-    return;
-  }
+  _internal_metadata_.DeleteReturnArena<::google::protobuf::UnknownFieldSet>();
   SharedDtor();
 }
 inline void GeneratedCodeInfo::SharedDtor() {