feat: Enable Hermes to work on iOS (facebook#29914)

Summary:
This PR makes it possible to build iOS applications with Hermes. Note that it doesn't work with `use_frameworks!` just yet.

Fixes facebook#27845 (by downgrading iOS deployment target for RCT-Folly to 9.0)
Fixes facebook#28810 (as above)

Checklist:
- [x] Adjust release scripts to create Hermes bytecode bundle
- [x] Release new Hermes npm package that includes iOS files (unreleased right now, if you want to try locally, you have to clone Hermes and `yarn link` its master to this project)
- [x] Test on a new React Native application in both Debug and Release (Device)
- [x] Test on an RNTester application in both Debug and Release (Device)
- [x] Add missing `i386` to Hermes framework and enable Bitcode
- [x] Inspect CI failures for possible regressions
- [x] Resolve Folly issue as reported facebook#27845 and facebook#28810
- [x] Release new Hermes and test against it that everything works

## Changelog

[IOS] [FEATURE] - Enable Hermes on iOS
[INTERNAL] - Upgrade to CocoaPods 1.10.0 to resolve Xcode 12.0 issues
[INTERNAL] - Upgrade to Xcode 12.0 on the CircleCI
[INTERNAL] - Fix building RNTester in Release mode
[INTERNAL] - Fix build-time errors of `libevent` with `use_frameworks!`
[INTERNAL] - Introduce `USE_HERMES` variable and test all RNTester configurations on the CI
[INTERNAL] - Do not fetch CocoaPods repository since we're using CDN anyway

Pull Request resolved: facebook#29914

Test Plan:
Turn on `hermes_enabled` to true in your `Podfile`, install pods, and run the iOS application. Your app should be running Hermes now.

Preview: (note "Engine: Hermes")

<img width="395" alt="Screenshot 2020-09-09 at 19 22 32" src="https://user-images.githubusercontent.com/2464966/92631584-d7c01d80-f2d1-11ea-9b40-33d73db96a53.png">

Reviewed By: hramos

Differential Revision: D24684845

Pulled By: cpojer

fbshipit-source-id: 900cbe3bf9398a6fd4a773d552899a001bf5146b

Author: grabbou

.circleci/config.yml

@@ -20,7 +20,6 @@ defaults: &defaults
     - PUBLIC_ANALYSISBOT_GITHUB_TOKEN_A: &github_token_a "78a72af35445ca3f8180"
     - PUBLIC_ANALYSISBOT_GITHUB_TOKEN_B: &github_token_b "b1a98e0bbd56ff1ccba1"
 
-
 # -------------------------
 #        EXECUTORS
 # -------------------------
@@ -152,13 +151,13 @@ commands:
           command: cp packages/rn-tester/Podfile.lock packages/rn-tester/Podfile.lock.bak
       - restore_cache:
           keys:
-            - v1-pods-{{ .Environment.CIRCLE_JOB }}-{{ checksum "packages/rn-tester/Podfile.lock.bak" }}
-            - v1-pods-{{ .Environment.CIRCLE_JOB }}-
+            - v3-pods-{{ .Environment.CIRCLE_JOB }}-{{ checksum "packages/rn-tester/Podfile.lock.bak" }}
+            - v3-pods-{{ .Environment.CIRCLE_JOB }}-
       - steps: << parameters.steps >>
       - save_cache:
           paths:
             - packages/rn-tester/Pods
-          key: v1-pods-{{ .Environment.CIRCLE_JOB }}-{{ checksum "packages/rn-tester/Podfile.lock.bak" }}
+          key: v3-pods-{{ .Environment.CIRCLE_JOB }}-{{ checksum "packages/rn-tester/Podfile.lock.bak" }}
 
   download_gradle_dependencies:
     steps:
@@ -216,12 +215,12 @@ commands:
 jobs:
   setup:
     parameters:
-        executor:
-          type: executor
-          default: nodelts
-        checkout_type:
-          type: string
-          default: node
+      executor:
+        type: executor
+        default: nodelts
+      checkout_type:
+        type: string
+        default: node
     executor: << parameters.executor >>
     steps:
       - checkout
@@ -261,7 +260,6 @@ jobs:
             DANGER_GITHUB_API_TOKEN="$PUBLIC_PULLBOT_GITHUB_TOKEN_A""$PUBLIC_PULLBOT_GITHUB_TOKEN_B" yarn danger ci --use-github-checks
           when: always
 
-
   # -------------------------
   #    JOBS: Analyze Code
   # -------------------------
@@ -351,6 +349,9 @@ jobs:
       use_frameworks:
         type: boolean
         default: false
+      use_hermes:
+        type: boolean
+        default: false
       run_unit_tests:
         description: Specifies whether unit tests should run.
         type: boolean
@@ -407,6 +408,13 @@ jobs:
                 name: Set USE_FRAMEWORKS=1
                 command: echo "export USE_FRAMEWORKS=1" >> $BASH_ENV
 
+      - when:
+          condition: << parameters.use_hermes >>
+          steps:
+            - run:
+                name: Set USE_HERMES=1
+                command: echo "export USE_HERMES=1" >> $BASH_ENV
+
       - run:
           name: Setup the CocoaPods environment
           command: pod setup
@@ -765,20 +773,31 @@ workflows:
           requires:
             - setup_android
       - test_ios:
-          name: test_ios_unit
-          run_disabled_tests: false
+          name: test_ios_unit_jsc
+          run_unit_tests: true
+          requires:
+            - setup_ios
+      - test_ios:
+          name: test_ios_unit_frameworks_jsc
+          use_frameworks: true
+          run_unit_tests: true
+          requires:
+            - setup_ios
+      - test_ios:
+          name: test_ios_unit_hermes
+          use_hermes: true
           run_unit_tests: true
           requires:
             - setup_ios
       - test_ios:
-          name: test_ios_unit_frameworks
+          name: test_ios_unit_frameworks_hermes
+          use_hermes: true
           use_frameworks: true
           run_unit_tests: true
           requires:
             - setup_ios
       # - test_ios:
       #     name: test_ios_detox
-      #     run_disabled_tests: false
       #     run_detox_tests: true
       #     requires:
       #       - setup_ios

IntegrationTests/GlobalEvalWithSourceUrlTest.js

@@ -10,6 +10,8 @@
 
 'use strict';
 
+import type {ExtendedError} from 'react-native/Libraries/Core/Devtools/parseErrorStack';
+
 const React = require('react');
 const ReactNative = require('react-native');
 const parseErrorStack = require('react-native/Libraries/Core/Devtools/parseErrorStack');
@@ -31,7 +33,7 @@ class GlobalEvalWithSourceUrlTest extends React.Component<{...}> {
         'Expected globalEvalWithSourceUrl(expression) to return a value',
       );
     }
-    let syntaxError;
+    let syntaxError: ?ExtendedError;
     try {
       global.globalEvalWithSourceUrl('{');
     } catch (e) {
@@ -42,7 +44,12 @@ class GlobalEvalWithSourceUrlTest extends React.Component<{...}> {
         'Expected globalEvalWithSourceUrl to throw on a syntax error',
       );
     }
-    if (!(syntaxError instanceof SyntaxError)) {
+    // Hermes throws an Error instead of a SyntaxError
+    // https://github.com/facebook/hermes/issues/400
+    if (
+      syntaxError.jsEngine !== 'hermes' &&
+      !(syntaxError instanceof SyntaxError)
+    ) {
       throw new Error(
         'Expected globalEvalWithSourceUrl to throw SyntaxError on a syntax error',
       );

React-Core.podspec

@@ -63,14 +63,14 @@ Pod::Spec.new do |s|
   end
 
   s.subspec "Hermes" do |ss|
-    ss.platforms = { :osx => "10.14" }
+    ss.platforms = { :osx => "10.14", :ios => "10.0" }
     ss.source_files = "ReactCommon/hermes/executor/*.{cpp,h}",
                       "ReactCommon/hermes/inspector/*.{cpp,h}",
                       "ReactCommon/hermes/inspector/chrome/*.{cpp,h}",
                       "ReactCommon/hermes/inspector/detail/*.{cpp,h}"
     ss.pod_target_xcconfig = { "GCC_PREPROCESSOR_DEFINITIONS" => "HERMES_ENABLE_DEBUGGER=1" }
     ss.dependency "RCT-Folly/Futures"
-    ss.dependency "hermes", "~> 0.6.0"
+    ss.dependency "hermes-engine"
   end
 
   s.subspec "DevSupport" do |ss|

React/CxxBridge/RCTCxxBridge.mm

@@ -37,7 +37,7 @@
 #import <jsireact/JSIExecutor.h>
 #import <reactperflogger/BridgeNativeModulePerfLogger.h>
 
-#if TARGET_OS_OSX && __has_include(<hermes/hermes.h>)
+#if __has_include(<hermes/hermes.h>)
 #define RCT_USE_HERMES 1
 #endif
 #if RCT_USE_HERMES

packages/rn-tester/Podfile

@@ -8,12 +8,16 @@ if ENV['USE_FRAMEWORKS'] == '1'
   use_frameworks!
 end
 
+if ENV['USE_HERMES'] == '1'
+  puts "Using Hermes engine"
+end
+
 def pods()
   project 'RNTesterPods.xcodeproj'
 
   # Enable TurboModule
   prefix_path = "../.."
-  use_react_native!(path:prefix_path)
+  use_react_native!(path: prefix_path, hermes_enabled: ENV['USE_HERMES'] == '1')
   pod 'ReactCommon/turbomodule/samples', :path => "#{prefix_path}/ReactCommon"
 
   # Additional Pods which aren't included in the default Podfile

packages/rn-tester/Podfile.lock

@@ -505,7 +505,7 @@ SPEC CHECKSUMS:
   RCTTypeSafety: 4da4f9f218727257c50fd3bf2683a06cdb4fede3
   React: 87b3271d925336a94620915db5845c67c5dbbd77
   React-callinvoker: e9524d75cf0b7ae108868f8d34c0b8d7dc08ec03
-  React-Core: f4eeb7ca3d6a7c2879d1d5b093800f23da9be617
+  React-Core: 40874579985cf440232e3f33ce172be1f04d4964
   React-CoreModules: 87f011fa87190ffe979e443ce578ec93ec6ff4d4
   React-cxxreact: de6de17eac6bbaa4f9fad46b66e7f0c4aaaf863d
   React-jsi: 790da16b69a61adc36829eed43c44187c1488d10
@@ -528,6 +528,6 @@ SPEC CHECKSUMS:
   Yoga: 69ef0b2bba5387523f793957a9f80dbd61e89631
   YogaKit: f782866e155069a2cca2517aafea43200b01fd5a
 
-PODFILE CHECKSUM: 1d1cdc29892e8a27b768e0e7ce1ead435a53bf0c
+PODFILE CHECKSUM: 497dba59a3312b3cb22d518b96672409db90460d
 
 COCOAPODS: 1.10.0

packages/rn-tester/README.md

@@ -15,7 +15,7 @@ Before running the app, make sure you ran:
 Both macOS and Xcode are required.
 - `cd packages/rn-tester`
 - Install [Bundler](https://bundler.io/): `gem install bundler`. We use bundler to install the right version of [CocoaPods](https://cocoapods.org/) locally.
-- Install Bundler and CocoaPods dependencies: `bundle install && bundle exec pod install`
+- Install Bundler and CocoaPods dependencies: `bundle install && bundle exec pod install`. In order to use Hermes engine instead of JSC, run: `USE_HERMES=1 bundle exec pod install` instead.
 - Open the generated `RNTesterPods.xcworkspace`. This is not checked in, as it is generated by CocoaPods. Do not open `RNTesterPods.xcodeproj` directly.
 
 ### Running on Android

packages/rn-tester/RNTester/AppDelegate.mm

@@ -7,7 +7,15 @@
 
 #import "AppDelegate.h"
 
+#if __has_include(<hermes/hermes.h>)
+#define RCT_USE_HERMES 1
+#endif
+#if RCT_USE_HERMES
+#import <React/HermesExecutorFactory.h>
+#else
 #import <React/JSCExecutorFactory.h>
+#endif
+
 #import <React/RCTJSIExecutorRuntimeInstaller.h>
 #import <React/RCTBridge.h>
 #import <React/RCTBundleURLProvider.h>
@@ -165,7 +173,11 @@ - (void)loadSourceForBridge:(RCTBridge *)bridge
 #endif
 
   __weak __typeof(self) weakSelf = self;
+#if RCT_USE_HERMES
+  return std::make_unique<facebook::react::HermesExecutorFactory>(
+#else
   return std::make_unique<facebook::react::JSCExecutorFactory>(
+#endif
     facebook::react::RCTJSIExecutorRuntimeInstaller([weakSelf, bridge](facebook::jsi::Runtime &runtime) {
       if (!bridge) {
         return;

packages/rn-tester/RNTesterIntegrationTests/RCTLoggingTests.m

@@ -90,7 +90,7 @@ - (void)testLogging
 
   XCTAssertEqual(_lastLogLevel, RCTLogLevelError);
   XCTAssertEqual(_lastLogSource, RCTLogSourceJavaScript);
-  XCTAssertEqualObjects(_lastLogMessage, @"Invariant Violation: Invariant failed");
+  XCTAssertTrue([_lastLogMessage containsString:@"Invariant Violation: Invariant failed"]);
 
   [_bridge enqueueJSCall:@"LoggingTestModule.logErrorToConsole" args:@[@"Invoking console.error"]];
   dispatch_semaphore_wait(_logSem, DISPATCH_TIME_FOREVER);
@@ -114,7 +114,7 @@ - (void)testLogging
 
   XCTAssertEqual(_lastLogLevel, RCTLogLevelError);
   XCTAssertEqual(_lastLogSource, RCTLogSourceJavaScript);
-  XCTAssertEqualObjects(_lastLogMessage, @"Error: Throwing an error");
+  XCTAssertTrue([_lastLogMessage containsString:@"Error: Throwing an error"]);
 }
 
 @end

packages/rn-tester/RNTesterPods.xcodeproj/project.pbxproj

@@ -60,6 +60,13 @@
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
+		ADA4EF572546F3F8000B7E75 /* PBXContainerItemProxy */ = {
+			isa = PBXContainerItemProxy;
+			containerPortal = 83CBB9F71A601CBA00E9B192 /* Project object */;
+			proxyType = 1;
+			remoteGlobalIDString = 13B07F861A680F5B00A75B9A;
+			remoteInfo = RNTester;
+		};
 		E7DB215822B2F332005AC45F /* PBXContainerItemProxy */ = {
 			isa = PBXContainerItemProxy;
 			containerPortal = 83CBB9F71A601CBA00E9B192 /* Project object */;
@@ -422,6 +429,7 @@
 			buildRules = (
 			);
 			dependencies = (
+				ADA4EF582546F3F8000B7E75 /* PBXTargetDependency */,
 			);
 			name = RNTesterUnitTests;
 			productName = RNTesterUnitTests;
@@ -723,6 +731,11 @@
 /* End PBXSourcesBuildPhase section */
 
 /* Begin PBXTargetDependency section */
+		ADA4EF582546F3F8000B7E75 /* PBXTargetDependency */ = {
+			isa = PBXTargetDependency;
+			target = 13B07F861A680F5B00A75B9A /* RNTester */;
+			targetProxy = ADA4EF572546F3F8000B7E75 /* PBXContainerItemProxy */;
+		};
 		E7DB215922B2F332005AC45F /* PBXTargetDependency */ = {
 			isa = PBXTargetDependency;
 			target = 13B07F861A680F5B00A75B9A /* RNTester */;

scripts/react-native-xcode.sh

@@ -107,14 +107,26 @@ fi
 # shellcheck source=/dev/null
 source "$REACT_NATIVE_DIR/scripts/node-binary.sh"
 
+[ -z "$HERMES_CLI_PATH" ] && HERMES_CLI_PATH="$PODS_ROOT/hermes-engine/destroot/bin/hermesc"
+
+if [[ -z "$USE_HERMES" && -f "$HERMES_CLI_PATH" ]]; then
+  echo "Enabling Hermes byte-code compilation. Disable with USE_HERMES=false if needed."
+  USE_HERMES=true
+fi
+
+if [[ $USE_HERMES == true && ! -f "$HERMES_CLI_PATH" ]]; then
+  echo "error: USE_HERMES is set to true but the hermesc binary could not be " \
+       "found at ${HERMES_CLI_PATH}. Perhaps you need to run pod install or otherwise " \
+       "point the HERMES_CLI_PATH variable to your custom location." >&2
+  exit 2
+fi
+
 [ -z "$NODE_ARGS" ] && export NODE_ARGS=""
 
 [ -z "$CLI_PATH" ] && export CLI_PATH="$REACT_NATIVE_DIR/cli.js"
 
 [ -z "$BUNDLE_COMMAND" ] && BUNDLE_COMMAND="bundle"
 
-[ -z "$HERMES_PATH" ] && HERMES_PATH="$PROJECT_ROOT/node_modules/hermes-engine-darwin/destroot/bin/hermesc"
-
 [ -z "$COMPOSE_SOURCEMAP_PATH" ] && COMPOSE_SOURCEMAP_PATH="$REACT_NATIVE_DIR/scripts/compose-source-maps.js"
 
 if [[ -z "$BUNDLE_CONFIG" ]]; then
@@ -136,11 +148,6 @@ case "$PLATFORM_NAME" in
     ;;
 esac
 
-USE_HERMES=
-if [[ "$BUNDLE_PLATFORM" == "macos" && -f "$HERMES_PATH" ]]; then
-  USE_HERMES=true
-fi
-
 EMIT_SOURCEMAP=
 if [[ ! -z "$SOURCEMAP_FILE" ]]; then
   EMIT_SOURCEMAP=true
@@ -180,14 +187,12 @@ else
   if [[ $EMIT_SOURCEMAP == true ]]; then
     EXTRA_COMPILER_ARGS="$EXTRA_COMPILER_ARGS -output-source-map"
   fi
-  HBC_FILE="$CONFIGURATION_BUILD_DIR/$(basename $BUNDLE_FILE)"
-  "$HERMES_PATH" -emit-binary $EXTRA_COMPILER_ARGS -out "$HBC_FILE" "$BUNDLE_FILE"
-  mv "$HBC_FILE" "$DEST/"
-  BUNDLE_FILE="$DEST/main.jsbundle"
+  "$HERMES_CLI_PATH" -emit-binary $EXTRA_COMPILER_ARGS -out "$DEST/main.jsbundle" "$BUNDLE_FILE" 
   if [[ $EMIT_SOURCEMAP == true ]]; then
-    HBC_SOURCEMAP_FILE="$HBC_FILE.map"
+    HBC_SOURCEMAP_FILE="$BUNDLE_FILE.map"
     "$NODE_BINARY" "$COMPOSE_SOURCEMAP_PATH" "$PACKAGER_SOURCEMAP_FILE" "$HBC_SOURCEMAP_FILE" -o "$SOURCEMAP_FILE"
   fi
+  BUNDLE_FILE="$DEST/main.jsbundle"
 fi
 
 if [[ $DEV != true && ! -f "$BUNDLE_FILE" ]]; then

scripts/react_native_pods.rb

@@ -6,7 +6,6 @@
 def use_react_native! (options={})
   # The prefix to the react-native
   prefix = options[:path] ||= "../node_modules/react-native"
-  hermes_engine_prefix = options[:hermes_path] ||= "../node_modules/hermes-engine-darwin"
 
   # Include Fabric dependencies
   fabric_enabled = options[:fabric_enabled] ||= false
@@ -64,7 +63,7 @@ def use_react_native! (options={})
 
   if hermes_enabled
     pod 'React-Core/Hermes', :path => "#{prefix}/"
-    pod 'hermes', :path => hermes_engine_prefix
+    pod 'hermes-engine'
     pod 'libevent', :podspec => "#{prefix}/third-party-podspecs/libevent.podspec"
   end
 end