Add Hermes support to React Native

RNTester/android/app/build.gradle

@@ -68,7 +68,10 @@ project.ext.react = [
     bundleAssetName: "RNTesterApp.android.bundle",
     entryFile: file("../../js/RNTesterApp.android.js"),
     root: "$rootDir",
-    inputExcludes: ["android/**", "./**", ".gradle/**"]
+    inputExcludes: ["android/**", "./**", ".gradle/**"],
+    composeSourceMapsPath: "$rootDir/scripts/compose-source-maps.js",
+    hermesCommand: "../../../node_modules/hermesvm/%OS-BIN%/hermes",
+    enableHermesForVariant: { def v -> v.name.contains("hermes") }
 ]
 
 apply from: "../../../react.gradle"
@@ -105,6 +108,16 @@ android {
         targetCompatibility JavaVersion.VERSION_1_8
     }
 
+    flavorDimensions "vm"
+    productFlavors {
+      hermes {
+        dimension "vm"
+      }
+      jsc {
+        dimension "vm"
+      }
+    }
+
     defaultConfig {
         applicationId "com.facebook.react.uiapp"
         minSdkVersion 16
@@ -138,6 +151,12 @@ android {
             signingConfig signingConfigs.release
         }
     }
+    packagingOptions {
+        pickFirst '**/armeabi-v7a/libc++_shared.so'
+        pickFirst '**/x86/libc++_shared.so'
+        pickFirst '**/arm64-v8a/libc++_shared.so'
+        pickFirst '**/x86_64/libc++_shared.so'
+    }
 }
 
 dependencies {
@@ -146,6 +165,10 @@ dependencies {
     // Build React Native from source
     implementation project(':ReactAndroid')
 
+    def hermesPath = '$projectDir/../../../../node_modules/hermesvm/android/'
+    debugImplementation files(hermesPath + "hermes-debug.aar")
+    releaseImplementation files(hermesPath + "hermes-release.aar")
+
     if (useIntlJsc) {
         implementation 'org.webkit:android-jsc-intl:+'
     } else {

RNTester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -11,8 +11,12 @@
 import com.facebook.react.ReactApplication;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
+import com.facebook.react.bridge.JavaScriptExecutorFactory;
+import com.facebook.hermes.reactexecutor.HermesExecutorFactory;
 import com.facebook.react.shell.MainReactPackage;
 import com.facebook.react.views.text.ReactFontManager;
+import com.facebook.soloader.SoLoader;
+
 import java.util.Arrays;
 import java.util.List;
 
@@ -44,6 +48,7 @@ public List<ReactPackage> getPackages() {
   public void onCreate() {
     ReactFontManager.getInstance().addCustomFont(this, "Rubik", R.font.rubik);
     super.onCreate();
+    SoLoader.init(this, /* native exopackage */ false);
   }
 
   @Override

ReactAndroid/build.gradle

@@ -91,6 +91,17 @@ task prepareFolly(dependsOn: dependenciesPath ? [] : [downloadFolly], type: Copy
     into("$thirdPartyNdkDir/folly")
 }
 
+task prepareHermes() {
+    def hermesAAR = new File("$projectDir/../node_modules/hermesvm/android/hermes-debug.aar")
+    def soFiles = zipTree(hermesAAR).matching({ it.include "**/*.so" })
+
+    copy {
+        from soFiles
+        from "src/main/jni/first-party/hermes/Android.mk"
+        into "$thirdPartyNdkDir/hermes"
+    }
+}
+
 task downloadGlog(dependsOn: createNativeDepsDirectories, type: Download) {
     src("https://github.com/google/glog/archive/v${GLOG_VERSION}.tar.gz")
     onlyIfNewer(true)
@@ -232,7 +243,7 @@ def getNdkBuildFullPath() {
     return ndkBuildFullPath
 }
 
-task buildReactNdkLib(dependsOn: [prepareJSC, prepareBoost, prepareDoubleConversion, prepareFolly, prepareGlog], type: Exec) {
+task buildReactNdkLib(dependsOn: [prepareJSC, prepareHermes, prepareBoost, prepareDoubleConversion, prepareFolly, prepareGlog], type: Exec) {
     inputs.dir("$projectDir/../ReactCommon")
     inputs.dir("src/main/jni")
     inputs.dir("src/main/java/com/facebook/react/modules/blob")
@@ -270,6 +281,7 @@ task packageReactNdkLibs(dependsOn: buildReactNdkLib, type: Copy) {
     from("$buildDir/react-ndk/all")
     into("$buildDir/react-ndk/exported")
     exclude("**/libjsc.so")
+    exclude("**/libhermes.so")
 }
 
 task packageReactNdkLibsForBuck(dependsOn: packageReactNdkLibs, type: Copy) {

ReactAndroid/src/main/java/com/facebook/hermes/instrumentation/HermesMemoryDumper.h

@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fb/fbjni.h>
+#include <string>
+
+namespace facebook {
+namespace jsi {
+namespace jni {
+
+namespace jni = ::facebook::jni;
+
+class HermesMemoryDumper : public jni::JavaClass<HermesMemoryDumper> {
+ public:
+  constexpr static auto kJavaDescriptor =
+      "Lcom/facebook/hermes/instrumentation/HermesMemoryDumper;";
+
+  bool shouldSaveSnapshot() {
+    static auto shouldSaveSnapshotMethod =
+        javaClassStatic()->getMethod<jboolean()>("shouldSaveSnapshot");
+    return shouldSaveSnapshotMethod(self());
+  }
+
+  std::string getInternalStorage() {
+    static auto getInternalStorageMethod =
+        javaClassStatic()->getMethod<jstring()>("getInternalStorage");
+    return getInternalStorageMethod(self())->toStdString();
+  }
+
+  std::string getId() {
+    static auto getInternalStorageMethod =
+        javaClassStatic()->getMethod<jstring()>("getId");
+    return getInternalStorageMethod(self())->toStdString();
+  }
+
+  void setMetaData(std::string crashId) {
+    static auto getIdMethod =
+        javaClassStatic()->getMethod<void(std::string)>("setMetaData");
+    getIdMethod(self(), crashId);
+  }
+};
+
+} // namespace jni
+} // namespace jsi
+} // namespace facebook

ReactAndroid/src/main/java/com/facebook/hermes/instrumentation/HermesMemoryDumper.java

@@ -0,0 +1,14 @@
+/**
+ * Copyright (c) Facebook, Inc. and its 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.hermes.instrumentation;
+
+public interface HermesMemoryDumper {
+  boolean shouldSaveSnapshot();
+  String getInternalStorage();
+  String getId();
+  void setMetaData(String crashId);
+}

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/Android.mk

@@ -0,0 +1,40 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+REACT_NATIVE := $(LOCAL_PATH)/../../../../../../../..
+
+LOCAL_MODULE := hermes-executor-release
+
+LOCAL_SRC_FILES := $(wildcard $(LOCAL_PATH)/*.cpp)
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH) $(REACT_NATIVE)/ReactCommon/jsi $(REACT_NATIVE)/node_modules/hermesvm/android/include
+
+LOCAL_CPP_FEATURES := exceptions
+
+LOCAL_STATIC_LIBRARIES := libjsireact libjsi
+LOCAL_SHARED_LIBRARIES := libfolly_json libfb libreactnativejni libhermes
+
+include $(BUILD_SHARED_LIBRARY)
+
+
+include $(CLEAR_VARS)
+REACT_NATIVE := $(LOCAL_PATH)/../../../../../../../..
+
+LOCAL_MODULE := hermes-executor-debug
+LOCAL_CFLAGS := -DHERMES_ENABLE_DEBUGGER=1
+
+LOCAL_SRC_FILES := $(wildcard $(LOCAL_PATH)/*.cpp)
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH) $(REACT_NATIVE)/ReactCommon/jsi $(REACT_NATIVE)/node_modules/hermesvm/android/include
+
+LOCAL_CPP_FEATURES := exceptions
+
+LOCAL_STATIC_LIBRARIES := libjsireact libjsi libhermes-inspector
+LOCAL_SHARED_LIBRARIES := libfolly_json libfb libreactnativejni libhermes
+
+include $(BUILD_SHARED_LIBRARY)

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/HermesExecutor.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) Facebook, Inc. and its 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.hermes.reactexecutor;
+
+import com.facebook.hermes.instrumentation.HermesMemoryDumper;
+import com.facebook.jni.HybridData;
+import com.facebook.react.bridge.JavaScriptExecutor;
+import com.facebook.soloader.SoLoader;
+import java.util.concurrent.ScheduledExecutorService;
+import javax.annotation.Nullable;
+
+public class HermesExecutor extends JavaScriptExecutor {
+  private static String mode_;
+  static {
+    // libhermes must be loaded explicitly to invoke its JNI_OnLoad.
+    SoLoader.loadLibrary("hermes");
+    try {
+      SoLoader.loadLibrary("hermes-executor-release");
+      mode_ = "Release";
+    } catch(UnsatisfiedLinkError e) {
+      SoLoader.loadLibrary("hermes-executor-debug");
+      mode_ = "Debug";
+    }
+  }
+
+  HermesExecutor(@Nullable RuntimeConfig config) {
+    super(
+        config == null
+            ? initHybridDefaultConfig()
+            : initHybrid(
+                config.heapSizeMB,
+                config.es6Symbol,
+                config.bytecodeWarmupPercent,
+                config.tripWireEnabled,
+                config.heapDumper,
+                config.tripWireCooldownMS,
+                config.tripWireLimitBytes));
+  }
+
+  @Override
+  public String getName() {
+    return "HermesExecutor" + mode_;
+  }
+
+  /**
+   * Return whether this class can load a file at the given path, based on a binary compatibility
+   * check between the contents of the file and the Hermes VM.
+   *
+   * @param path the path containing the file to inspect.
+   * @return whether the given file is compatible with the Hermes VM.
+   */
+  public static native boolean canLoadFile(String path);
+
+  private static native HybridData initHybridDefaultConfig();
+
+  private static native HybridData initHybrid(
+      long heapSizeMB,
+      boolean es6Symbol,
+      int bytecodeWarmupPercent,
+      boolean tripWireEnabled,
+      @Nullable HermesMemoryDumper heapDumper,
+      long tripWireCooldownMS,
+      long tripWireLimitBytes);
+}