Fix: Xcode 12.5+ build of iPhone Simulator on Apple M1 (#32284)

Summary:
Since Apple released its own silicon M1, an ARM64, the react-native build is broken or at least not as effective as it should.

This PR stops excluding `arm64` simulator (this is not needed on the M1 neither on Intel devices) and removes the problematic `$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)` from `LIBRARY_SEARCH_PATHS`, since on Xcode 12.5 and 13.0 this folder contains only `i386/x86_64` binaries and will fail compilation.

Instead this PR forces `$(SDKROOT)/usr/lib/swift` while it removes the incorrect directory. Ideally we could just remove `LIBRARY_SEARCH_PATHS` altogether if `$(inherited)` and `$(SDKROOT)/usr/lib/swift` were the only entries, but it would require us a **newer CocoaPods**, since that was fixed with `1.11` (see  https://github.com/CocoaPods/CocoaPods/commit/6985cbf7de73f645029e8a716cad0c89ff81e3c8). Since we don't enforce that, lets keep the `$(SDKROOT)/usr/lib/swift` and call it done.

Last but not least, deprecate the `__apply_Xcode_12_5_M1_post_install_workaround()` as it's not needed anymore, at least with recent versions of the dependencies, no patching is required with RCT-Folly, neither we need to force `IPHONEOS_DEPLOYMENT_TARGET=11.0`

## Changelog

[iOS] [Fixed] - Xcode 12.5+ build of iPhone Simulator on Apple M1
[iOS] [Changed] - Do not exclude the arm64 iphonesimulator
[iOS] [Deprecated] - __apply_Xcode_12_5_M1_post_install_workaround()

Pull Request resolved: https://github.com/facebook/react-native/pull/32284

Test Plan:
* Build `packages/rn-tester` on M1 and see it still works properly
* Run `pod install` on x86_64 and arm64 (m1) and see the `project.pbxproj` is not changed

## References:
* Closes https://github.com/facebook/react-native/issues/31480
* The initial fix https://github.com/facebook/react-native/commit/ac4ddec542febda744de218dae3a3d34edc7da84
* Upgrading CocoaPods to 1.11 would bring us https://github.com/CocoaPods/CocoaPods/commit/6985cbf7de73f645029e8a716cad0c89ff81e3c8 and we could avoid adding `$(SDKROOT)/usr/lib/swift` ourselves

Reviewed By: lunaleaps

Differential Revision: D31248460

Pulled By: fkgozali

fbshipit-source-id: 5a0d69593e889e296a2ba2e7b4387ecbd56fc08d

packages/rn-tester/Podfile

@@ -52,5 +52,4 @@ end
 
 post_install do |installer|
   react_native_post_install(installer)
-  __apply_Xcode_12_5_M1_post_install_workaround(installer)
 end

packages/rn-tester/Podfile.lock

@@ -919,6 +919,6 @@ SPEC CHECKSUMS:
   Yoga: c0d06f5380d34e939f55420669a60fe08b79bd75
   YogaKit: f782866e155069a2cca2517aafea43200b01fd5a
 
-PODFILE CHECKSUM: 21be0a8894b752aaab399f9d4075cf41baf345f3
+PODFILE CHECKSUM: f2609ec079811d7784b6e802b8351314bd41de51
 
 COCOAPODS: 1.10.1

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

@@ -785,7 +785,6 @@
 				LIBRARY_SEARCH_PATHS = (
 					"\"$(SDKROOT)/usr/lib/swift\"",
 					"$(inherited)",
-					"$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)",
 					"$(TOOLCHAIN_DIR)/usr/lib/swift/$(PLATFORM_NAME)",
 				);
 				"LIBRARY_SEARCH_PATHS[arch=*]" = "$(inherited)";
@@ -820,7 +819,6 @@
 				LIBRARY_SEARCH_PATHS = (
 					"\"$(SDKROOT)/usr/lib/swift\"",
 					"$(inherited)",
-					"$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)",
 					"$(TOOLCHAIN_DIR)/usr/lib/swift/$(PLATFORM_NAME)",
 				);
 				OTHER_LDFLAGS = (
@@ -873,7 +871,7 @@
 				ENABLE_BITCODE = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
-				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = "arm64 ";
+				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = "";
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_NO_COMMON_BLOCKS = YES;
@@ -957,7 +955,7 @@
 				ENABLE_BITCODE = NO;
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
-				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = "arm64 ";
+				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = "";
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_TREAT_INCOMPATIBLE_POINTER_TYPE_WARNINGS_AS_ERRORS = YES;

scripts/react_native_pods.rb

@@ -127,30 +127,60 @@ def exclude_architectures(installer)
     .uniq{ |p| p.path }
     .push(installer.pods_project)
 
-  arm_value = `/usr/sbin/sysctl -n hw.optional.arm64 2>&1`.to_i
-
   # Hermes does not support `i386` architecture
   excluded_archs_default = has_pod(installer, 'hermes-engine') ? "i386" : ""
 
   projects.each do |project|
     project.build_configurations.each do |config|
-      if arm_value == 1 then
-        config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = excluded_archs_default
-      else
-        config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = "arm64 " + excluded_archs_default
-      end
+      config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = excluded_archs_default
     end
 
     project.save()
   end
 end
 
+def fix_library_search_paths(installer)
+  def fix_config(config)
+    lib_search_paths = config.build_settings["LIBRARY_SEARCH_PATHS"]
+    if lib_search_paths
+      if lib_search_paths.include?("$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)") || lib_search_paths.include?("\"$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)\"")
+        # $(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME) causes problem with Xcode 12.5 + arm64 (Apple M1)
+        # since the libraries there are only built for x86_64 and i386.
+        lib_search_paths.delete("$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)")
+        lib_search_paths.delete("\"$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)\"")
+        if !(lib_search_paths.include?("$(SDKROOT)/usr/lib/swift") || lib_search_paths.include?("\"$(SDKROOT)/usr/lib/swift\""))
+          # however, $(SDKROOT)/usr/lib/swift is required, at least if user is not running CocoaPods 1.11
+          lib_search_paths.insert(0, "$(SDKROOT)/usr/lib/swift")
+        end
+      end
+    end
+  end
+
+  projects = installer.aggregate_targets
+    .map{ |t| t.user_project }
+    .uniq{ |p| p.path }
+    .push(installer.pods_project)
+
+  projects.each do |project|
+    project.build_configurations.each do |config|
+      fix_config(config)
+    end
+    project.native_targets.each do |target|
+      target.build_configurations.each do |config|
+        fix_config(config)
+      end
+    end
+    project.save()
+  end
+end
+
 def react_native_post_install(installer)
   if has_pod(installer, 'Flipper')
     flipper_post_install(installer)
   end
 
   exclude_architectures(installer)
+  fix_library_search_paths(installer)
 end
 
 def use_react_native_codegen!(spec, options={})
@@ -337,32 +367,8 @@ end
 # See https://github.com/facebook/react-native/issues/31480#issuecomment-902912841 for more context.
 # Actual fix was authored by https://github.com/mikehardy.
 # New app template will call this for now until the underlying issue is resolved.
+#
+# It's not needed anymore and will be removed later
 def __apply_Xcode_12_5_M1_post_install_workaround(installer)
-  # Apple Silicon builds require a library path tweak for Swift library discovery to resolve Swift-related "symbol not found".
-  # Note: this was fixed via https://github.com/facebook/react-native/commit/eb938863063f5535735af2be4e706f70647e5b90
-  # Keeping this logic here but commented out for future reference.
-  #
-  # installer.aggregate_targets.each do |aggregate_target|
-  #   aggregate_target.user_project.native_targets.each do |target|
-  #     target.build_configurations.each do |config|
-  #       config.build_settings['LIBRARY_SEARCH_PATHS'] = ['$(SDKROOT)/usr/lib/swift', '$(inherited)']
-  #     end
-  #   end
-  #   aggregate_target.user_project.save
-  # end
-
-  # Flipper podspecs are still targeting an older iOS deployment target, and may cause an error like:
-  #   "error: thread-local storage is not supported for the current target"
-  # The most reliable known workaround is to bump iOS deployment target to match react-native (iOS 11 now).
-  installer.pods_project.targets.each do |target|
-    target.build_configurations.each do |config|
-      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '11.0'
-      end
-  end
-
-  # But... doing so caused another issue in Flipper:
-  #   "Time.h:52:17: error: typedef redefinition with different types"
-  # We need to make a patch to RCT-Folly - set `__IPHONE_10_0` to our iOS target + 1.
-  # See https://github.com/facebook/flipper/issues/834 for more details.
-  `sed -i -e  $'s/__IPHONE_10_0/__IPHONE_12_0/' #{installer.sandbox.root}/RCT-Folly/folly/portability/Time.h`
+  puts "__apply_Xcode_12_5_M1_post_install_workaround() is not needed anymore"
 end

template/ios/HelloWorld.xcodeproj/project.pbxproj

@@ -437,7 +437,6 @@
 				LIBRARY_SEARCH_PATHS = (
 					"\"$(SDKROOT)/usr/lib/swift\"",
 					"\"$(TOOLCHAIN_DIR)/usr/lib/swift/$(PLATFORM_NAME)\"",
-					"\"$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)\"",
 					"\"$(inherited)\"",
 				);
 				MTL_ENABLE_DEBUG_INFO = YES;
@@ -495,7 +494,6 @@
 				LIBRARY_SEARCH_PATHS = (
 					"\"$(SDKROOT)/usr/lib/swift\"",
 					"\"$(TOOLCHAIN_DIR)/usr/lib/swift/$(PLATFORM_NAME)\"",
-					"\"$(TOOLCHAIN_DIR)/usr/lib/swift-5.0/$(PLATFORM_NAME)\"",
 					"\"$(inherited)\"",
 				);
 				MTL_ENABLE_DEBUG_INFO = NO;