Enable JSC (#38007)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/38007

Enable JSC for Bridgeless and wire it up with RNTester Android

Changelog: [Internal]

Reviewed By: fkgozali

Differential Revision: D46527692

fbshipit-source-id: 68f36a6db5573a70156864904bb428a4f789d4f5

packages/react-native/ReactAndroid/build.gradle

@@ -512,6 +512,7 @@ android {
                     "rninstance",
                     "hermesinstancejni",
                     "uimanagerjni",
+                    "jscinstance",
                     // prefab targets
                     "reactnativejni",
                     "react_render_debug",

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridgeless/JSCInstance.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.bridgeless;
+
+import com.facebook.infer.annotation.Nullsafe;
+import com.facebook.jni.HybridData;
+import com.facebook.jni.annotations.DoNotStrip;
+import com.facebook.soloader.SoLoader;
+
+@Nullsafe(Nullsafe.Mode.LOCAL)
+public class JSCInstance extends JSEngineInstance {
+  static {
+    SoLoader.loadLibrary("jscinstance");
+  }
+
+  @DoNotStrip
+  protected static native HybridData initHybrid();
+
+  public JSCInstance() {
+    super(initHybrid());
+  }
+}

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridgeless/ReactHost.java

@@ -22,6 +22,7 @@ import com.facebook.infer.annotation.Assertions;
 import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.infer.annotation.ThreadConfined;
 import com.facebook.infer.annotation.ThreadSafe;
+import com.facebook.react.JSEngineResolutionAlgorithm;
 import com.facebook.react.MemoryPressureRouter;
 import com.facebook.react.ReactInstanceEventListener;
 import com.facebook.react.bridge.Callback;
@@ -122,6 +123,7 @@ public class ReactHost implements ReactHostInterface {
 
   private static final AtomicInteger mCounter = new AtomicInteger(0);
   private final int mId = mCounter.getAndIncrement();
+  private @Nullable JSEngineResolutionAlgorithm mJSEngineResolutionAlgorithm = null;
 
   public ReactHost(
       Context context,
@@ -1504,4 +1506,13 @@ public class ReactHost implements ReactHostInterface {
       }
     }
   }
+
+  public void setJSEngineResolutionAlgorithm(
+      @Nullable JSEngineResolutionAlgorithm jsEngineResolutionAlgorithm) {
+    mJSEngineResolutionAlgorithm = jsEngineResolutionAlgorithm;
+  }
+
+  public @Nullable JSEngineResolutionAlgorithm getJSEngineResolutionAlgorithm() {
+    return mJSEngineResolutionAlgorithm;
+  }
 }

packages/react-native/ReactAndroid/src/main/jni/CMakeLists.txt

@@ -120,6 +120,7 @@ add_react_android_subdir(src/main/jni/react/hermes/reactexecutor)
 add_react_android_subdir(src/main/jni/react/hermes/instrumentation/)
 add_react_android_subdir(src/main/jni/react/bridgeless/jni)
 add_react_android_subdir(src/main/jni/react/bridgeless/hermes/jni)
+add_react_android_subdir(src/main/jni/react/bridgeless/jsc/jni)
 
 # GTest dependencies
 add_executable(reactnative_unittest

packages/react-native/ReactAndroid/src/main/jni/react/bridgeless/jsc/jni/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+cmake_minimum_required(VERSION 3.13)
+set(CMAKE_VERBOSE_MAKEFILE on)
+
+add_compile_options(-fvisibility=hidden -fexceptions -frtti)
+
+file(GLOB jscinstance_SRC CONFIGURE_DEPENDS "*.cpp")
+add_library(jscinstance SHARED ${jscinstance_SRC})
+
+target_include_directories(jscinstance PUBLIC .)
+
+target_link_libraries(
+        jscinstance
+        bridgeless
+        jscruntime
+        fbjni
+        reactnativejni
+)

packages/react-native/ReactAndroid/src/main/jni/react/bridgeless/jsc/jni/OnLoad.cpp

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <fbjni/fbjni.h>
+#include <jsc/JSCRuntime.h>
+#include <jsi/jsi.h>
+#include <react/bridgeless/JSEngineInstance.h>
+#include <react/bridgeless/jni/JJSEngineInstance.h>
+#include <react/jni/ReadableNativeMap.h>
+
+namespace facebook::react {
+
+class JSCInstance : public jni::HybridClass<JSCInstance, JJSEngineInstance> {
+ public:
+  static constexpr auto kJavaDescriptor =
+      "Lcom/facebook/react/bridgeless/JSCInstance;";
+
+  static jni::local_ref<jhybriddata> initHybrid(jni::alias_ref<jhybridobject>) {
+    return makeCxxInstance();
+  }
+
+  static void registerNatives() {
+    registerHybrid({
+        makeNativeMethod("initHybrid", JSCInstance::initHybrid),
+    });
+  }
+
+  std::unique_ptr<jsi::Runtime> createJSRuntime() noexcept {
+    return jsc::makeJSCRuntime();
+  }
+
+ private:
+  friend HybridBase;
+  using HybridBase::HybridBase;
+};
+
+} // namespace facebook::react
+
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved) {
+  return facebook::jni::initialize(
+      vm, [] { facebook::react::JSCInstance::registerNatives(); });
+}

packages/rn-tester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -10,6 +10,7 @@ package com.facebook.react.uiapp;
 import android.app.Application;
 import androidx.annotation.NonNull;
 import com.facebook.fbreact.specs.SampleTurboModule;
+import com.facebook.react.JSEngineResolutionAlgorithm;
 import com.facebook.react.ReactApplication;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
@@ -144,11 +145,18 @@ public class RNTesterApplication extends Application implements ReactApplication
     if (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
       DefaultNewArchitectureEntryPoint.load();
     }
-    ReactNativeFlipper.initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
+    if (ReactFeatureFlags.enableBridgelessArchitecture) {
+      // TODO: initialize Flipper for Bridgeless
+    } else {
+      ReactNativeFlipper.initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
+    }
   }
 
   @Override
   public ReactNativeHost getReactNativeHost() {
+    if (ReactFeatureFlags.enableBridgelessArchitecture) {
+      throw new RuntimeException("Should not use ReactNativeHost when Bridgeless enabled");
+    }
     return mReactNativeHost;
   }
 
@@ -173,6 +181,11 @@ public class RNTesterApplication extends Application implements ReactApplication
               true,
               reactJsExceptionHandler,
               true);
+      if (BuildConfig.IS_HERMES_ENABLED_IN_FLAVOR) {
+        mReactHost.setJSEngineResolutionAlgorithm(JSEngineResolutionAlgorithm.HERMES);
+      } else {
+        mReactHost.setJSEngineResolutionAlgorithm(JSEngineResolutionAlgorithm.JSC);
+      }
       reactHostDelegate.setReactHost(mReactHost);
     }
     return mReactHost;

packages/rn-tester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterReactHostDelegate.java

@@ -11,6 +11,7 @@ import android.content.Context;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.facebook.fbreact.specs.SampleTurboModule;
+import com.facebook.react.JSEngineResolutionAlgorithm;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.ReactPackageTurboModuleManagerDelegate;
 import com.facebook.react.TurboReactPackage;
@@ -18,6 +19,7 @@ import com.facebook.react.bridge.JSBundleLoader;
 import com.facebook.react.bridge.NativeModule;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridgeless.BindingsInstaller;
+import com.facebook.react.bridgeless.JSCInstance;
 import com.facebook.react.bridgeless.JSEngineInstance;
 import com.facebook.react.bridgeless.ReactHost;
 import com.facebook.react.bridgeless.ReactHostDelegate;
@@ -77,7 +79,11 @@ public class RNTesterReactHostDelegate implements ReactHostDelegate {
 
   @Override
   public JSEngineInstance getJSEngineInstance() {
-    return new HermesInstance();
+    if (mReactHost.getJSEngineResolutionAlgorithm() == JSEngineResolutionAlgorithm.JSC) {
+      return new JSCInstance();
+    } else {
+      return new HermesInstance();
+    }
   }
 
   @Override