javache · Oct 26, 2026 · Oct 26, 2026
diff --git a/packages/react-native/Libraries/Image/RCTImageLoader.mm b/packages/react-native/Libraries/Image/RCTImageLoader.mm
@@ -32,7 +32,7 @@ static NSInteger RCTImageBytesForImage(UIImage *image)
   return image.images ? image.images.count * singleImageBytes : singleImageBytes;
 }
 
-static auto currentRequestCount = std::atomic<uint64_t>(0);
+static constinit auto currentRequestCount = std::atomic<uint64_t>(0);
 
 static NSError *addResponseHeadersToError(NSError *originalError, NSHTTPURLResponse *response)
 {

diff --git a/packages/react-native/Libraries/Network/RCTNetworkTask.mm b/packages/react-native/Libraries/Network/RCTNetworkTask.mm
@@ -21,7 +21,7 @@ @implementation RCTNetworkTask {
   RCTNetworkTask *_selfReference;
 }
 
-static auto currentRequestId = std::atomic<NSUInteger>(0);
+static constinit auto currentRequestId = std::atomic<NSUInteger>(0);
 
 - (instancetype)initWithRequest:(NSURLRequest *)request
                         handler:(id<RCTURLRequestHandler>)handler

diff --git a/packages/react-native/React/Base/RCTUtils.mm b/packages/react-native/React/Base/RCTUtils.mm
@@ -386,7 +386,7 @@ UIDeviceOrientation RCTDeviceOrientation(void)
 
 CGSize RCTScreenSize(void)
 {
-  static std::atomic<CGSize> cachedSize;
+  static constinit std::atomic<CGSize> cachedSize;
   __block CGSize size = cachedSize.load(std::memory_order_relaxed);
 
   if (CGSizeEqualToSize(size, CGSizeZero)) {

diff --git a/packages/react-native/React/CoreModules/RCTDevSettings.mm b/packages/react-native/React/CoreModules/RCTDevSettings.mm
@@ -127,7 +127,7 @@ - (void)_reloadWithDefaults:(NSDictionary *)defaultValues
 #if RCT_DEV_SETTINGS_ENABLE_PACKAGER_CONNECTION
 static RCTHandlerToken reloadToken;
 static RCTHandlerToken devMenuToken;
-static std::atomic<int> numInitializedModules{0};
+static constinit std::atomic<int> numInitializedModules{0};
 #endif
 
 @interface RCTDevSettings () <RCTBridgeModule, RCTInvalidating, NativeDevSettingsSpec, RCTDevSettingsInspectable> {

diff --git a/packages/react-native/ReactAndroid/src/main/jni/first-party/fbgloginit/glog_init.cpp b/packages/react-native/ReactAndroid/src/main/jni/first-party/fbgloginit/glog_init.cpp
@@ -112,7 +112,7 @@ lastResort(const char* tag, const char* msg, const char* arg = nullptr) {
 namespace facebook::gloginit {
 
 void initialize(const char* tag) {
-  static std::once_flag flag{};
+  static constinit std::once_flag flag{};
   static auto failed = false;
 
   std::call_once(flag, [tag] {

diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/hermes/reactexecutor/OnLoad.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/hermes/reactexecutor/OnLoad.cpp
@@ -25,7 +25,7 @@ static void hermesFatalHandler(const std::string& reason) {
   __android_log_assert(nullptr, "Hermes", "%s", reason.c_str());
 }
 
-static std::once_flag flag;
+static constinit std::once_flag flag;
 
 static ::hermes::vm::RuntimeConfig makeRuntimeConfig(jlong heapSizeMB) {
   namespace vm = ::hermes::vm;

diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/jni/JReactMarker.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/jni/JReactMarker.cpp
@@ -18,7 +18,7 @@ const int kInstanceKey = 1;
 }
 
 void JReactMarker::setLogPerfMarkerIfNeeded() {
-  static std::once_flag flag{};
+  static constinit std::once_flag flag{};
   std::call_once(flag, []() {
     ReactMarker::logTaggedMarkerImpl = JReactMarker::logPerfMarker;
   });

diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/jni/SafeReleaseJniRef.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/jni/SafeReleaseJniRef.cpp
@@ -20,7 +20,7 @@ void ensureThreadDurationJNIEnvAttached() {
   // > exits, and call DetachCurrentThread() from there.
   // https://github.com/facebookincubator/fbjni/blob/7b7efda0d49b956acf1d3307510e3c73fc55b404/cxx/fbjni/detail/Environment.h#L101
   // https://developer.android.com/training/articles/perf-jni#threads
-  static thread_local std::optional<jni::ThreadScope> threadScope;
+  static constinit thread_local std::optional<jni::ThreadScope> threadScope;
 
   if (jni::detail::currentOrNull() == nullptr) {
     threadScope.emplace();

diff --git a/packages/react-native/ReactCommon/cxxreact/TraceSection.h b/packages/react-native/ReactCommon/cxxreact/TraceSection.h
@@ -168,7 +168,7 @@ inline os_log_t instrumentsLogHandle = nullptr;
 
 static inline os_log_t getOrCreateInstrumentsLogHandle()
 {
-  static std::once_flag flag{};
+  static constinit std::once_flag flag{};
   std::call_once(flag, []() {
     if (!instrumentsLogHandle) {
       instrumentsLogHandle = os_log_create("dev.reactnative.instruments", OS_LOG_CATEGORY_DYNAMIC_TRACING);

diff --git a/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp b/packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<3acecfdec6d182a74c4616d6c8690e72>>
+ * @generated SignedSource<<c8699b32c5c6bade5ace861696a7526f>>
  */
 
 /**
@@ -23,7 +23,7 @@ namespace facebook::react {
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wglobal-constructors"
-std::unique_ptr<ReactNativeFeatureFlagsAccessor> accessor_;
+constinit std::unique_ptr<ReactNativeFeatureFlagsAccessor> accessor_;
 #pragma GCC diagnostic pop
 
 bool ReactNativeFeatureFlags::commonTestFlag() {

diff --git a/...ive/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModuleManager.mm b/...ive/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModuleManager.mm
@@ -42,7 +42,7 @@
 namespace {
 int32_t getUniqueId()
 {
-  static std::atomic<int32_t> counter{0};
+  static constinit std::atomic<int32_t> counter{0};
   return counter++;
 }
 

diff --git a/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.cpp b/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.cpp
@@ -39,7 +39,7 @@ namespace facebook::react {
 
 // Global function pointer for getting current time. Current time
 // can be injected for testing purposes.
-static TimePointFunction g_now = &std::chrono::steady_clock::now;
+static constinit TimePointFunction g_now = &std::chrono::steady_clock::now;
 void g_setNativeAnimatedNowTimestampFunction(TimePointFunction nowFunction) {
   g_now = nowFunction;
 }
@@ -91,7 +91,8 @@ void mergeObjects(folly::dynamic& out, const folly::dynamic& objectToMerge) {
 
 } // namespace
 
-thread_local bool NativeAnimatedNodesManager::isOnRenderThread_{false};
+constinit thread_local bool NativeAnimatedNodesManager::isOnRenderThread_{
+    false};
 
 NativeAnimatedNodesManager::NativeAnimatedNodesManager(
     DirectManipulationCallback&& directManipulationCallback,

diff --git a/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.h b/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.h
@@ -236,7 +236,7 @@ class NativeAnimatedNodesManager : public std::enable_shared_from_this<NativeAni
 
   std::unique_ptr<AnimatedNode> animatedNode(Tag tag, const folly::dynamic &config) noexcept;
 
-  static thread_local bool isOnRenderThread_;
+  static constinit thread_local bool isOnRenderThread_;
 
   std::mutex animatedNodesCreatedAsyncMutex_;
   std::unordered_map<Tag, std::unique_ptr<AnimatedNode>> animatedNodesCreatedAsync_;

diff --git a/packages/react-native/ReactCommon/react/renderer/components/text/BaseParagraphProps.cpp b/packages/react-native/ReactCommon/react/renderer/components/text/BaseParagraphProps.cpp
@@ -64,7 +64,7 @@ void BaseParagraphProps::setProp(
   // of these fields together, and because there are some collisions between
   // propnames parsed here and outside of ParagraphAttributes.
   // This code is also duplicated in AndroidTextInput.
-  static auto paDefaults = ParagraphAttributes{};
+  static constinit auto paDefaults = ParagraphAttributes{};
   switch (hash) {
     REBUILD_FIELD_SWITCH_CASE(
         paDefaults,

diff --git a/packages/react-native/ReactCommon/react/renderer/components/textinput/BaseTextInputProps.cpp b/packages/react-native/ReactCommon/react/renderer/components/textinput/BaseTextInputProps.cpp
@@ -151,7 +151,7 @@ void BaseTextInputProps::setProp(
   // propnames parsed here and outside of ParagraphAttributes. For example,
   // textBreakStrategy is duplicated.
   // This code is also duplicated in ParagraphProps.
-  static auto paDefaults = ParagraphAttributes{};
+  static constinit auto paDefaults = ParagraphAttributes{};
   switch (hash) {
     REBUILD_FIELD_SWITCH_CASE(
         paDefaults,

diff --git a/...ages/react-native/ReactCommon/react/renderer/components/view/YogaLayoutableShadowNode.cpp b/...ages/react-native/ReactCommon/react/renderer/components/view/YogaLayoutableShadowNode.cpp
@@ -62,7 +62,7 @@ static int FabricDefaultYogaLog(
   return size_s;
 }
 
-thread_local LayoutContext threadLocalLayoutContext;
+constinit thread_local LayoutContext threadLocalLayoutContext;
 
 YogaLayoutableShadowNode::YogaLayoutableShadowNode(
     const ShadowNodeFragment& fragment,

diff --git a/packages/react-native/ReactCommon/react/renderer/components/view/YogaStylableProps.cpp b/packages/react-native/ReactCommon/react/renderer/components/view/YogaStylableProps.cpp
@@ -118,7 +118,7 @@ void YogaStylableProps::setProp(
     RawPropsPropNameHash hash,
     const char* propName,
     const RawValue& value) {
-  static const auto ygDefaults = yoga::Style{};
+  static constinit const auto ygDefaults = yoga::Style{};
   static const auto defaults = YogaStylableProps{};
 
   Props::setProp(context, hash, propName, value);

diff --git a/packages/react-native/ReactCommon/react/renderer/core/ReactRootViewTagGenerator.cpp b/packages/react-native/ReactCommon/react/renderer/core/ReactRootViewTagGenerator.cpp
@@ -15,7 +15,7 @@ constexpr SurfaceId ROOT_VIEW_TAG_INCREMENT = 10;
 
 SurfaceId getNextRootViewTag() noexcept {
   // Numbering of these tags goes from 11, 21, 31, ..., 100501, ...
-  static std::atomic<SurfaceId> nextRootViewTag = 1;
+  static constinit std::atomic<SurfaceId> nextRootViewTag = 1;
   return nextRootViewTag += ROOT_VIEW_TAG_INCREMENT;
 }
 

diff --git a/packages/react-native/ReactCommon/react/renderer/core/ShadowNode.cpp b/packages/react-native/ReactCommon/react/renderer/core/ShadowNode.cpp
@@ -25,7 +25,8 @@ namespace facebook::react {
  * tree simultaneously. This thread_local flag allows enabling the updates for
  * chosen threads.
  */
-thread_local bool useRuntimeShadowNodeReferenceUpdateOnThread{false}; // NOLINT
+constinit thread_local bool useRuntimeShadowNodeReferenceUpdateOnThread{
+    false}; // NOLINT
 
 /* static */ void ShadowNode::setUseRuntimeShadowNodeReferenceUpdateOnThread(
     bool isEnabled) {

diff --git a/packages/react-native/ReactCommon/react/renderer/core/ShadowNodeFragment.cpp b/packages/react-native/ReactCommon/react/renderer/core/ShadowNodeFragment.cpp
@@ -16,20 +16,20 @@ namespace facebook::react {
 #endif
 
 const Props::Shared& ShadowNodeFragment::propsPlaceholder() {
-  NO_DESTROY static Props::Shared instance;
+  NO_DESTROY static constinit Props::Shared instance;
   return instance;
 }
 
 const std::shared_ptr<const std::vector<std::shared_ptr<const ShadowNode>>>&
 ShadowNodeFragment::childrenPlaceholder() {
-  NO_DESTROY static std::shared_ptr<
+  NO_DESTROY static constinit std::shared_ptr<
       const std::vector<std::shared_ptr<const ShadowNode>>>
       instance;
   return instance;
 }
 
 const State::Shared& ShadowNodeFragment::statePlaceholder() {
-  NO_DESTROY static State::Shared instance;
+  NO_DESTROY static constinit State::Shared instance;
   return instance;
 }
 

diff --git a/.../react/renderer/graphics/platform/android/react/renderer/graphics/PlatformColorParser.cpp b/.../react/renderer/graphics/platform/android/react/renderer/graphics/PlatformColorParser.cpp
@@ -69,12 +69,12 @@ SharedColor parsePlatformColor(
     if (!resourcePaths.empty()) {
       // Cache the (costly) JNI results. A cached nullopt is an explicit miss,
       // distinct from a path that resolves to transparent (ARGB 0).
-      static std::mutex getColorCacheMutex;
+      static constinit std::mutex getColorCacheMutex;
       static folly::EvictingCacheMap<size_t, std::optional<Color>>
           getColorCache(64);
 
       // Listen for appearance changes, which should invalidate the cache
-      static std::once_flag setupCacheInvalidation;
+      static constinit std::once_flag setupCacheInvalidation;
       std::call_once(
           setupCacheInvalidation,
           configurePlatformColorCacheInvalidationHook,

diff --git a/...ages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Legacy.cpp b/...ages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Legacy.cpp
@@ -133,7 +133,7 @@ void RuntimeScheduler_Legacy::executeNowOnTheSameThread(
     RawCallback&& callback) {
   TraceSection s("RuntimeScheduler::executeNowOnTheSameThread");
 
-  static thread_local jsi::Runtime* runtimePtr = nullptr;
+  static constinit thread_local jsi::Runtime* runtimePtr = nullptr;
 
   if (runtimePtr == nullptr) {
     runtimeAccessRequests_ += 1;

diff --git a/...ages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Modern.cpp b/...ages/react-native/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler_Modern.cpp
@@ -153,7 +153,7 @@ void RuntimeScheduler_Modern::executeNowOnTheSameThread(
     RawCallback&& callback) {
   TraceSection s("RuntimeScheduler::executeNowOnTheSameThread");
 
-  static thread_local jsi::Runtime* runtimePtr = nullptr;
+  static constinit thread_local jsi::Runtime* runtimePtr = nullptr;
 
   auto currentTime = now_();
   auto priority = SchedulerPriority::ImmediatePriority;

diff --git a/packages/react-native/ReactCommon/react/renderer/runtimescheduler/Task.cpp b/packages/react-native/ReactCommon/react/renderer/runtimescheduler/Task.cpp
@@ -13,7 +13,7 @@ namespace facebook::react {
 namespace {
 
 inline uint64_t getNextId() noexcept {
-  static std::atomic<uint64_t> nextId = 1;
+  static constinit std::atomic<uint64_t> nextId = 1;
   return nextId++;
 }
 

diff --git a/packages/react-native/ReactCommon/react/renderer/telemetry/TransactionTelemetry.cpp b/packages/react-native/ReactCommon/react/renderer/telemetry/TransactionTelemetry.cpp
@@ -13,7 +13,8 @@
 
 namespace facebook::react {
 
-thread_local TransactionTelemetry* threadLocalTransactionTelemetry = nullptr;
+constinit thread_local TransactionTelemetry* threadLocalTransactionTelemetry =
+    nullptr;
 
 TransactionTelemetry::TransactionTelemetry()
     : TransactionTelemetry(telemetryTimePointNow) {}

diff --git a/packages/react-native/ReactCommon/reactperflogger/reactperflogger/ReactPerfetto.cpp b/packages/react-native/ReactCommon/reactperflogger/reactperflogger/ReactPerfetto.cpp
@@ -22,7 +22,7 @@
 
 namespace facebook::react {
 
-std::once_flag perfettoInit;
+constinit std::once_flag perfettoInit;
 void initializePerfetto() {
   std::call_once(perfettoInit, []() {
     perfetto::TracingInitArgs args;

diff --git a/.../ReactCommon/runtimeexecutor/platform/ios/ReactCommon/RuntimeExecutorSyncUIThreadUtils.mm b/.../ReactCommon/runtimeexecutor/platform/ios/ReactCommon/RuntimeExecutorSyncUIThreadUtils.mm
@@ -53,7 +53,7 @@ OnScopeExit onScopeExit(^{
 // Protects access to g_uiTask
 std::mutex &g_mutex()
 {
-  static std::mutex mutex;
+  static constinit std::mutex mutex;
   return mutex;
 }
 
@@ -65,13 +65,13 @@ OnScopeExit onScopeExit(^{
 
 std::mutex &g_ticket()
 {
-  static std::mutex ticket;
+  static constinit std::mutex ticket;
   return ticket;
 }
 
 std::optional<UITask> &g_uiTask()
 {
-  static std::optional<UITask> uiTaskQueue;
+  static constinit std::optional<UITask> uiTaskQueue;
   return uiTaskQueue;
 }
 

diff --git a/packages/react-native/ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp b/packages/react-native/ReactCommon/yoga/yoga/algorithm/CalculateLayout.cpp
@@ -35,7 +35,7 @@
 
 namespace facebook::yoga {
 
-std::atomic<uint32_t> gCurrentGenerationCount(0);
+constinit std::atomic<uint32_t> gCurrentGenerationCount(0);
 
 static bool hasAutoHorizontalMargin(const Style& style) {
   for (const auto direction : {Direction::LTR, Direction::RTL}) {

diff --git a/packages/react-native/ReactCommon/yoga/yoga/event/event.cpp b/packages/react-native/ReactCommon/yoga/yoga/event/event.cpp
@@ -46,7 +46,7 @@ struct Node {
       : subscriber{std::move(subscriber)} {}
 };
 
-std::atomic<Node*> subscribers{nullptr};
+constinit std::atomic<Node*> subscribers{nullptr};
 
 Node* push(Node* newHead) {
   Node* oldHead = nullptr;

diff --git a/packages/react-native/ReactCxxPlatform/react/profiling/perfetto.cpp b/packages/react-native/ReactCxxPlatform/react/profiling/perfetto.cpp
@@ -11,7 +11,7 @@
 #include <mutex>
 
 void initializePerfetto() {
-  static std::once_flag s_PerfettoIsInitialized;
+  static constinit std::once_flag s_PerfettoIsInitialized;
 
   std::call_once(s_PerfettoIsInitialized, []() {
     perfetto::TracingInitArgs args;

diff --git a/...-native/scripts/featureflags/templates/common-cxx/ReactNativeFeatureFlags.cpp-template.js b/...-native/scripts/featureflags/templates/common-cxx/ReactNativeFeatureFlags.cpp-template.js
@@ -31,7 +31,7 @@ namespace facebook::react {
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wglobal-constructors"
-std::unique_ptr<ReactNativeFeatureFlagsAccessor> accessor_;
+constinit std::unique_ptr<ReactNativeFeatureFlagsAccessor> accessor_;
 #pragma GCC diagnostic pop
 
 ${Object.entries(definitions.common)