Internal change

PiperOrigin-RevId: 576883351

src/google/protobuf/extension_set.cc

@@ -11,6 +11,7 @@
 
 #include "google/protobuf/extension_set.h"
 
+#include <atomic>
 #include <string>
 #include <tuple>
 #include <type_traits>
@@ -1933,6 +1934,8 @@ LazyEagerVerifyFnType FindExtensionLazyEagerVerifyFn(
   return nullptr;
 }
 
+std::atomic<ExtensionSet::LazyMessageExtension* (*)(Arena* arena)>
+    ExtensionSet::maybe_create_lazy_extension_;
 
 }  // namespace internal
 }  // namespace protobuf

src/google/protobuf/extension_set.h

@@ -16,6 +16,7 @@
 #define GOOGLE_PROTOBUF_EXTENSION_SET_H__
 
 #include <algorithm>
+#include <atomic>
 #include <cassert>
 #include <string>
 #include <type_traits>
@@ -57,6 +58,7 @@ class FeatureSet;
 namespace internal {
 class FieldSkipper;  // wire_format_lite.h
 class WireFormat;
+void InitializeLazyExtensionSet();
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google
@@ -508,6 +510,8 @@ class PROTOBUF_EXPORT ExtensionSet {
   friend class google::protobuf::Reflection;
   friend class google::protobuf::internal::WireFormat;
 
+  friend void internal::InitializeLazyExtensionSet();
+
   const int32_t& GetRefInt32(int number, const int32_t& default_value) const;
   const int64_t& GetRefInt64(int number, const int64_t& default_value) const;
   const uint32_t& GetRefUInt32(int number, const uint32_t& default_value) const;
@@ -579,7 +583,13 @@ class PROTOBUF_EXPORT ExtensionSet {
     virtual void UnusedKeyMethod();  // Dummy key method to avoid weak vtable.
   };
   // Give access to function defined below to see LazyMessageExtension.
-  friend LazyMessageExtension* MaybeCreateLazyExtension(Arena* arena);
+  static LazyMessageExtension* MaybeCreateLazyExtensionImpl(Arena* arena);
+  static LazyMessageExtension* MaybeCreateLazyExtension(Arena* arena) {
+    auto* f = maybe_create_lazy_extension_.load(std::memory_order_relaxed);
+    return f != nullptr ? f(arena) : nullptr;
+  }
+  static std::atomic<LazyMessageExtension* (*)(Arena* arena)>
+      maybe_create_lazy_extension_;
   struct Extension {
     // The order of these fields packs Extension into 24 bytes when using 8
     // byte alignment. Consider this when adding or removing fields here.
@@ -1529,10 +1539,6 @@ class ExtensionIdentifier {
 // Generated accessors
 
 
-// Used to retrieve a lazy extension, may return nullptr in some environments.
-extern PROTOBUF_ATTRIBUTE_WEAK ExtensionSet::LazyMessageExtension*
-MaybeCreateLazyExtension(Arena* arena);
-
 // Define a specialization of ExtensionIdentifier for bootstrapped extensions
 // that we need to register lazily.
 template <>

src/google/protobuf/generated_message_reflection.cc

@@ -16,6 +16,7 @@
 #include <cstdint>
 #include <cstring>
 #include <string>
+#include <type_traits>
 
 #include "absl/base/call_once.h"
 #include "absl/base/casts.h"
@@ -93,6 +94,9 @@ void InitializeFileDescriptorDefaultInstances() {
 #endif  // !defined(PROTOBUF_CONSTINIT_DEFAULT_INSTANCES)
 }
 
+void InitializeLazyExtensionSet() {
+}
+
 bool ParseNamedEnum(const EnumDescriptor* descriptor, absl::string_view name,
                     int* value) {
   const EnumValueDescriptor* d = descriptor->FindValueByName(name);
@@ -3660,6 +3664,7 @@ void AddDescriptorsImpl(const DescriptorTable* table) {
   // Reflection refers to the default fields so make sure they are initialized.
   internal::InitProtobufDefaults();
   internal::InitializeFileDescriptorDefaultInstances();
+  internal::InitializeLazyExtensionSet();
 
   // Ensure all dependent descriptors are registered to the generated descriptor
   // pool and message factory.