[Objective-C interop] Invalid argument(s): Failed to lookup symbol 'objc_msgSend_fpret'

[LastMonopoly]

Hi all,

https://github.com/dart-lang/native/tree/main/pkgs/ffigen/example/objective_c
the above example no longer works when I generate bindings myself using dart run ffigen --config config.yaml

when I dart play_audio.dart test.mp3, the exception throws

Invalid argument(s): Failed to lookup symbol 'objc_msgSend_fpret': dlsym(0x3c28dd4a8, objc_msgSend_fpret): symbol not found

This is my flutter version

[✓] Flutter (Channel stable, 3.16.0, on macOS 14.1.1 23B81 darwin-arm64, locale en-CN)
    • Flutter version 3.16.0 on channel stable at /Users/xhan/fvm/versions/stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision db7ef5bf9f (11 days ago), 2023-11-15 11:25:44 -0800
    • Engine revision 74d16627b9
    • Dart version 3.2.0
    • DevTools version 2.28.2

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
    • Android SDK at /Users/xhan/Library/Android/sdk
    • Platform android-34, build-tools 34.0.0
    • ANDROID_HOME = /Users/xhan/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 15.0.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 15A507
    • CocoaPods version 1.14.3

This is the newly generated binding
avf_audio_bindings.dart.zip

Thanks.

[liamappelbe]

Hmmm. I did change the codegen to start using objc_msgSend_fpret and objc_msgSend_stret where appropriate a while ago, but they're supposed to be basic functions provided by the ObjC runtime.

I can't repro this on my end. I'm on the same version of macOS and Xcode as you, so I'm guessing the important difference is that you're on arm64 and I'm on x64. We have tests for these functions but I think the github mac bots also run x64. I remember reading that there were some architecture differences to do with these functions (though I'm surprised they're simply missing on arm64).

Anyway if these functions are missing we can just fall back to vanilla objc_msgSend, so it's an easy fix.

This example does need to be updated due to changes to the code generation in v10, so I'll send out a PR for that.

@dcharkes Do you have an arm64 mac? Are you able to repro this? Just wait until ^that PR lands and then run the pkgs/ffigen/example/objective_c example like dart play_audio.dart test.mp3.

[dcharkes]

I can repro this on 0051e78.

00:04 +68 -6: test/native_objc_test/block_test.dart: Blocks Struct block [E]                                                                                                                                                                                      
  Invalid argument(s): Failed to lookup symbol 'objc_msgSend_stret': dlsym(0x8bfb4b30, objc_msgSend_stret): symbol not found
  dart:ffi                                           DynamicLibrary.lookup

Maybe this comment was not correct: #449 (comment)

I don't find much googling around on fpret and stret and Apple silicon, but we don't seem to be the only ones having the issue: https://www.google.com/search?q=objc_msgSend_stret+not+found+arm64

[dcharkes]

@liamappelbe can you make a PR that branches based on Abi.current?

I believe we should also be able to test this on CI now: https://github.blog/2023-10-02-introducing-the-new-apple-silicon-powered-m1-macos-larger-runner-for-github-actions/