Reduce number of generated files for the feature flags system (facebo…

…ok#42820)

Summary:
Pull Request resolved: facebook#42820

The feature flag system generates a significant amount of files. This reduces that number to remove noise from diffs/PRs by eliminating a file that could be defined privately within another one.

Changelog: [internal]

Reviewed By: huntie

Differential Revision: D53352391

fbshipit-source-id: 51fccb3c1bb09ef3503cd34334d28c1021bd1b25

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<<e570b62b4a208b2526169361c3a6be6a>>
+ * @generated SignedSource<<18e31d0833fda8cfb3f31b449479297a>>
  */
 
 /**
@@ -19,10 +19,72 @@
 
 #include "JReactNativeFeatureFlagsCxxInterop.h"
 #include <react/featureflags/ReactNativeFeatureFlags.h>
-#include <react/featureflags/ReactNativeFeatureFlagsProviderHolder.h>
 
 namespace facebook::react {
 
+static jni::alias_ref<jni::JClass> getReactNativeFeatureFlagsProviderJavaClass() {
+  static const auto jClass = facebook::jni::findClassStatic(
+      "com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider");
+  return jClass;
+}
+
+/**
+ * Implementation of ReactNativeFeatureFlagsProvider that wraps a
+ * ReactNativeFeatureFlagsProvider Java object.
+ */
+class ReactNativeFeatureFlagsProviderHolder
+    : public ReactNativeFeatureFlagsProvider {
+ public:
+  explicit ReactNativeFeatureFlagsProviderHolder(
+      jni::alias_ref<jobject> javaProvider)
+      : javaProvider_(make_global(javaProvider)){};
+
+  bool commonTestFlag() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("commonTestFlag");
+    return method(javaProvider_);
+  }
+
+  bool useModernRuntimeScheduler() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("useModernRuntimeScheduler");
+    return method(javaProvider_);
+  }
+
+  bool enableMicrotasks() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableMicrotasks");
+    return method(javaProvider_);
+  }
+
+  bool batchRenderingUpdatesInEventLoop() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("batchRenderingUpdatesInEventLoop");
+    return method(javaProvider_);
+  }
+
+  bool enableSpannableBuildingUnification() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableSpannableBuildingUnification");
+    return method(javaProvider_);
+  }
+
+  bool enableCustomDrawOrderFabric() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableCustomDrawOrderFabric");
+    return method(javaProvider_);
+  }
+
+  bool enableFixForClippedSubviewsCrash() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableFixForClippedSubviewsCrash");
+    return method(javaProvider_);
+  }
+
+ private:
+  jni::global_ref<jobject> javaProvider_;
+};
+
 bool JReactNativeFeatureFlagsCxxInterop::commonTestFlag(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::commonTestFlag();

packages/react-native/scripts/featureflags/generateAndroidModules.js

@@ -18,8 +18,6 @@ import ReactNativeFeatureFlagsCxxInteropKt from './templates/android/ReactNative
 import ReactNativeFeatureFlagsDefaultsKt from './templates/android/ReactNativeFeatureFlagsDefaults.kt-template';
 import ReactNativeFeatureFlagsLocalAccessorKt from './templates/android/ReactNativeFeatureFlagsLocalAccessor.kt-template';
 import ReactNativeFeatureFlagsProviderKt from './templates/android/ReactNativeFeatureFlagsProvider.kt-template';
-import ReactNativeFeatureFlagsProviderHolderCPP from './templates/android/ReactNativeFeatureFlagsProviderHolder.cpp-template';
-import ReactNativeFeatureFlagsProviderHolderH from './templates/android/ReactNativeFeatureFlagsProviderHolder.h-template';
 import path from 'path';
 
 export default function generateAndroidModules(
@@ -40,10 +38,6 @@ export default function generateAndroidModules(
       ReactNativeFeatureFlagsDefaultsKt(featureFlagDefinitions),
     [path.join(androidPath, 'ReactNativeFeatureFlagsProvider.kt')]:
       ReactNativeFeatureFlagsProviderKt(featureFlagDefinitions),
-    [path.join(androidJniPath, 'ReactNativeFeatureFlagsProviderHolder.h')]:
-      ReactNativeFeatureFlagsProviderHolderH(featureFlagDefinitions),
-    [path.join(androidJniPath, 'ReactNativeFeatureFlagsProviderHolder.cpp')]:
-      ReactNativeFeatureFlagsProviderHolderCPP(featureFlagDefinitions),
     [path.join(androidJniPath, 'JReactNativeFeatureFlagsCxxInterop.h')]:
       JReactNativeFeatureFlagsCxxInteropH(featureFlagDefinitions),
     [path.join(androidJniPath, 'JReactNativeFeatureFlagsCxxInterop.cpp')]:

packages/react-native/scripts/featureflags/templates/android/JReactNativeFeatureFlagsCxxInterop.cpp-template.js

@@ -27,10 +27,43 @@ ${DO_NOT_MODIFY_COMMENT}
 
 #include "JReactNativeFeatureFlagsCxxInterop.h"
 #include <react/featureflags/ReactNativeFeatureFlags.h>
-#include <react/featureflags/ReactNativeFeatureFlagsProviderHolder.h>
 
 namespace facebook::react {
 
+static jni::alias_ref<jni::JClass> getReactNativeFeatureFlagsProviderJavaClass() {
+  static const auto jClass = facebook::jni::findClassStatic(
+      "com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider");
+  return jClass;
+}
+
+/**
+ * Implementation of ReactNativeFeatureFlagsProvider that wraps a
+ * ReactNativeFeatureFlagsProvider Java object.
+ */
+class ReactNativeFeatureFlagsProviderHolder
+    : public ReactNativeFeatureFlagsProvider {
+ public:
+  explicit ReactNativeFeatureFlagsProviderHolder(
+      jni::alias_ref<jobject> javaProvider)
+      : javaProvider_(make_global(javaProvider)){};
+
+${Object.entries(definitions.common)
+  .map(
+    ([flagName, flagConfig]) =>
+      `  ${getCxxTypeFromDefaultValue(
+        flagConfig.defaultValue,
+      )} ${flagName}() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("${flagName}");
+    return method(javaProvider_);
+  }`,
+  )
+  .join('\n\n')}
+
+ private:
+  jni::global_ref<jobject> javaProvider_;
+};
+
 ${Object.entries(definitions.common)
   .map(
     ([flagName, flagConfig]) =>