Skip native prop metadata for delegate-backed managers

Summary:
Add the default-off `skipNativePropsForViewManagerWithDelegateAndroid` feature flag. When enabled, `ViewManager.getNativeProps()` returns an empty map for managers with a non-null, non-generic delegate, avoiding unused manager and shadow-node prop metadata generation. The constants helper already omits `NativeProps` for an empty map; commands, events and custom constants are preserved.

Null and generic delegates keep the existing metadata path, including its legacy-architecture shadow-node handling. The flag must only be enabled when delegate-backed components use static view configs rather than runtime native prop metadata.

NativeProps queries reuse `getOrCreateViewManagerDelegate()`, sharing the same delegate with prop updates and commands. Make its lazy initialisation thread-safe with a volatile cache and double-checked synchronisation, leaving warm reads lock-free. Document that initialisation may occur on the JavaScript thread when this flag is enabled.

Regenerate all feature-flag bindings and cover enabled/disabled paths, generic and null delegates, marker-only managers, preserved constants, existing-cache reuse and concurrent metadata/command initialisation.

Changelog:
[Android][Changed] - Add an opt-in optimisation to skip native prop metadata for delegate-backed view managers using static view configs.

Differential Revision: D126630163

Author: javache

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -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<<cfa7aa53731059247d858fd8fb6e914b>>
+ * @generated SignedSource<<c96fb296a907fe2b264b3a1a79ada34a>>
  */
 
 /**
@@ -498,6 +498,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun skipActivityIdentityAssertionOnHostPause(): Boolean = accessor.skipActivityIdentityAssertionOnHostPause()
 
+  /**
+   * Skip native prop metadata generation on Android for view managers with custom delegates. Requires their components to use static view configs.
+   */
+  @JvmStatic
+  public fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean = accessor.skipNativePropsForViewManagerWithDelegateAndroid()
+
   /**
    * Override getClipBounds on Android views to return the padding box when overflow is hidden
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -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<<71d0554dc45df7d5365f81b7ec8c3d5b>>
+ * @generated SignedSource<<758c59473ba39a89b5db675c217bc690>>
  */
 
 /**
@@ -98,6 +98,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var shouldPressibilityUseW3CPointerEventsForHoverCache: Boolean? = null
   private var shouldTriggerResponderTransferOnScrollAndroidCache: Boolean? = null
   private var skipActivityIdentityAssertionOnHostPauseCache: Boolean? = null
+  private var skipNativePropsForViewManagerWithDelegateAndroidCache: Boolean? = null
   private var syncAndroidClipBoundsWithOverflowCache: Boolean? = null
   private var traceTurboModulePromiseRejectionsOnAndroidCache: Boolean? = null
   private var updateRuntimeShadowNodeReferencesOnCommitCache: Boolean? = null
@@ -817,6 +818,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean {
+    var cached = skipNativePropsForViewManagerWithDelegateAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.skipNativePropsForViewManagerWithDelegateAndroid()
+      skipNativePropsForViewManagerWithDelegateAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun syncAndroidClipBoundsWithOverflow(): Boolean {
     var cached = syncAndroidClipBoundsWithOverflowCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -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<<312cec99bd429d22e25f4e82d7fc4ee7>>
+ * @generated SignedSource<<fd9a11754ecbf1aee959b43cb17d00a2>>
  */
 
 /**
@@ -184,6 +184,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun skipActivityIdentityAssertionOnHostPause(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun syncAndroidClipBoundsWithOverflow(): Boolean
 
   @DoNotStrip @JvmStatic public external fun traceTurboModulePromiseRejectionsOnAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -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<<669f16e131d4a5ddc026ffecc6893575>>
+ * @generated SignedSource<<d4d0349b560fe12cdcb91860e5f0359f>>
  */
 
 /**
@@ -179,6 +179,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun skipActivityIdentityAssertionOnHostPause(): Boolean = false
 
+  override fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean = false
+
   override fun syncAndroidClipBoundsWithOverflow(): Boolean = false
 
   override fun traceTurboModulePromiseRejectionsOnAndroid(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -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<<ee4c0f9c1e7c6af3b0d15948ebc519b3>>
+ * @generated SignedSource<<7f4c0ebf000e27e2bdb29d32a801cc80>>
  */
 
 /**
@@ -102,6 +102,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var shouldPressibilityUseW3CPointerEventsForHoverCache: Boolean? = null
   private var shouldTriggerResponderTransferOnScrollAndroidCache: Boolean? = null
   private var skipActivityIdentityAssertionOnHostPauseCache: Boolean? = null
+  private var skipNativePropsForViewManagerWithDelegateAndroidCache: Boolean? = null
   private var syncAndroidClipBoundsWithOverflowCache: Boolean? = null
   private var traceTurboModulePromiseRejectionsOnAndroidCache: Boolean? = null
   private var updateRuntimeShadowNodeReferencesOnCommitCache: Boolean? = null
@@ -899,6 +900,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean {
+    var cached = skipNativePropsForViewManagerWithDelegateAndroidCache
+    if (cached == null) {
+      cached = currentProvider.skipNativePropsForViewManagerWithDelegateAndroid()
+      accessedFeatureFlags.add("skipNativePropsForViewManagerWithDelegateAndroid")
+      skipNativePropsForViewManagerWithDelegateAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun syncAndroidClipBoundsWithOverflow(): Boolean {
     var cached = syncAndroidClipBoundsWithOverflowCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -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<<18267103ef4f3eb22f23a15b808528c2>>
+ * @generated SignedSource<<10d76cfc6241dbbb530c2cba99611c91>>
  */
 
 /**
@@ -179,6 +179,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun skipActivityIdentityAssertionOnHostPause(): Boolean
 
+  @DoNotStrip public fun skipNativePropsForViewManagerWithDelegateAndroid(): Boolean
+
   @DoNotStrip public fun syncAndroidClipBoundsWithOverflow(): Boolean
 
   @DoNotStrip public fun traceTurboModulePromiseRejectionsOnAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManager.java

@@ -30,6 +30,7 @@
 import com.facebook.react.uimanager.annotations.ReactPropGroup;
 import com.facebook.react.uimanager.annotations.ReactPropertyHolder;
 import com.facebook.yoga.YogaMeasureMode;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
@@ -46,7 +47,7 @@ public abstract class ViewManager<T extends View, C extends ReactShadowNode<?>>
 
   private static final String TAG = "ViewManager";
 
-  private @Nullable ViewManagerDelegate<T> mDelegate = null;
+  private volatile @Nullable ViewManagerDelegate<T> mDelegate = null;
 
   /**
    * For View recycling: we store a Stack of unused, dead Views. This is null by default, and when
@@ -113,6 +114,11 @@ public void updateProperties(@NonNull T viewToUpdate, ReactStylesDiffMap props)
    * <p>By default, this methods returns a generic {@link ViewManagerDelegate} which uses {@link
    * ViewManagerSetter} to apply property updates.
    *
+   * <p>When {@code skipNativePropsForViewManagerWithDelegateAndroid} is enabled, lazy delegate
+   * initialisation may also occur during native prop metadata generation on the JavaScript thread.
+   * The returned delegate is cached and shared with subsequent prop updates and commands. Overrides
+   * must be safe to initialise on either thread.
+   *
    * @return an instance of {@link ViewManagerDelegate} if the props of the view managed by this
    *     view manager should be set via this delegate
    */
@@ -131,8 +137,13 @@ protected ViewManagerDelegate<T> getDelegate() {
   private ViewManagerDelegate<T> getOrCreateViewManagerDelegate() {
     ViewManagerDelegate<T> delegate = mDelegate;
     if (delegate == null) {
-      delegate = getDelegate();
-      mDelegate = delegate;
+      synchronized (this) {
+        delegate = mDelegate;
+        if (delegate == null) {
+          delegate = getDelegate();
+          mDelegate = delegate;
+        }
+      }
     }
     return delegate;
   }
@@ -404,8 +415,19 @@ public void receiveCommand(@NonNull T view, String commandId, ReadableArray args
   /**
    * Returns a {@link Map<String, String>} representing the native props of the view manager. The
    * Map contains the names (key) and types (value) of the ViewManager's props.
+   *
+   * <p>When {@code skipNativePropsForViewManagerWithDelegateAndroid} is enabled, managers with a
+   * non-generic delegate return an empty map. Enable this only when those components use static
+   * view configs rather than deriving their valid attributes from native prop metadata.
    */
   public Map<String, String> getNativeProps() {
+    if (ReactNativeFeatureFlags.skipNativePropsForViewManagerWithDelegateAndroid()) {
+      ViewManagerDelegate<T> delegate = getOrCreateViewManagerDelegate();
+      if (delegate != null
+          && !(delegate instanceof ViewManagerPropertyUpdater.GenericViewManagerDelegate)) {
+        return Collections.emptyMap();
+      }
+    }
     if (ReactBuildConfig.UNSTABLE_ENABLE_MINIFY_LEGACY_ARCHITECTURE
         && ReactNativeNewArchitectureFeatureFlags.enableBridgelessArchitecture()) {
       // TODO: review if we need to check fabricInterop here

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.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<<568d6e4175fb51e09bc3d4441ffa9741>>
+ * @generated SignedSource<<ec75566521a814c01401f86095e1ad73>>
  */
 
 /**
@@ -507,6 +507,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool skipNativePropsForViewManagerWithDelegateAndroid() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("skipNativePropsForViewManagerWithDelegateAndroid");
+    return method(javaProvider_);
+  }
+
   bool syncAndroidClipBoundsWithOverflow() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("syncAndroidClipBoundsWithOverflow");
@@ -997,6 +1003,11 @@ bool JReactNativeFeatureFlagsCxxInterop::skipActivityIdentityAssertionOnHostPaus
   return ReactNativeFeatureFlags::skipActivityIdentityAssertionOnHostPause();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::skipNativePropsForViewManagerWithDelegateAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::skipNativePropsForViewManagerWithDelegateAndroid();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::syncAndroidClipBoundsWithOverflow(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::syncAndroidClipBoundsWithOverflow();
@@ -1342,6 +1353,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "skipActivityIdentityAssertionOnHostPause",
         JReactNativeFeatureFlagsCxxInterop::skipActivityIdentityAssertionOnHostPause),
+      makeNativeMethod(
+        "skipNativePropsForViewManagerWithDelegateAndroid",
+        JReactNativeFeatureFlagsCxxInterop::skipNativePropsForViewManagerWithDelegateAndroid),
       makeNativeMethod(
         "syncAndroidClipBoundsWithOverflow",
         JReactNativeFeatureFlagsCxxInterop::syncAndroidClipBoundsWithOverflow),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -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<<2e0f936c003aafc456ab3f960ca4b2f3>>
+ * @generated SignedSource<<ed562f74bbdb2b852383eef39cef1592>>
  */
 
 /**
@@ -264,6 +264,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool skipActivityIdentityAssertionOnHostPause(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool skipNativePropsForViewManagerWithDelegateAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool syncAndroidClipBoundsWithOverflow(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);