[objective_c] Migrate to native assets

[liamappelbe]

Notes

• I'm using on @Native annotations to load all the ffi symbols. Previously this worked because I loaded the dylib into the executable first, then relied on the @Native fallback behavior to load the symbols from the exe. Now I'm explicitly setting the asset name to the built dylib, which appears to disable that fallback behavior. But all the core ObjC runtime symbols (eg objc_msgSend) are linked into the exe, not the dylib. So I had to split the C bindings into a set that loads from the dylib, and a set that loads from the exe. There are now 3 sets of ffigen created bindings: the objective C bindings (loads from the dylib), the bindings for my C code (loads from the dylib), and the bindings for the built in ObjC runtime's C code (loads from the exe).
• Similarly, I had an issue where the global variables exposed by the ObjC bindings were failing to load. So I moved them to the C runtime bindings so they'd be loaded from the exe. This exposed them as a raw Pointer<ObjCObject>, so I had to manually wrap them in NSStrings in globals.dart. I tried splitting the ObjC bindings like I split the C bindings, but this caused all sorts of other problems.
• ffigen has a dev dep on package:objective_c for testing. All the ObjC tests are disabled on linux and windows, but afaik there's no way of avoiding pulling in the dependency on those platforms. So I had to modify package:objective_c's build script to no-op on those platforms. Seems like a sub-optimal solution.

TODO: Mac CI failures are due to running the tests through package:coverage (dart-lang/tools#2237). Need to investigate why that's not finding the dylib. The mac tests not running through test_with_coverage are working. If this isn't a quick fix I can temporarily disable coverage collection for these tests.

[github-actions]

PR Health

License Headers ⚠️

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
pkgs/objective_c/example/lib/main.dart
pkgs/objective_c/lib/src/ns_input_stream.dart

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API leaks ⚠️

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbol	Leaking sources
objective_c	_FinalizablePointer	internal.dart::_ObjCReference::new::_finalizable

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Breaking changes ⚠️

Package	Change	Current Version	New Version	Needed Version	Looking good?
objective_c	Breaking	9.0.0	9.0.0	10.0.0 Got "9.0.0" expected >= "10.0.0" (breaking changes)	⚠️

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Changelog Entry ❗

Package

Changed Files

package:objective_c

pkgs/objective_c/example/README.md pkgs/objective_c/example/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md pkgs/objective_c/example/pubspec.yaml pkgs/objective_c/lib/objective_c.dart pkgs/objective_c/lib/src/autorelease.dart pkgs/objective_c/lib/src/c_bindings_generated.dart pkgs/objective_c/lib/src/globals.dart pkgs/objective_c/lib/src/internal.dart pkgs/objective_c/lib/src/ns_input_stream.dart pkgs/objective_c/lib/src/ns_string.dart pkgs/objective_c/lib/src/objective_c_bindings_exported.dart pkgs/objective_c/lib/src/objective_c_bindings_generated.dart pkgs/objective_c/lib/src/protocol_builder.dart pkgs/objective_c/lib/src/runtime_bindings_generated.dart pkgs/objective_c/lib/src/selector.dart pkgs/objective_c/pubspec.yaml

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[coveralls]

coverage: 82.093% (+0.1%) from 81.971%
when pulling c69e2f2 on objc_native
into 8215af2 on main.

[liamappelbe]

Still working on fixing CI, but this is ready for review.

[goderbauer]

fly-by comment: Do you need all these specific ignores given that ffigen generates a generic ignore for all lints?

[goderbauer]

Looks like these ignores snug back in? Or are they for some reason actually needed?

[goderbauer]

For my own understanding: Is it expected that stuff in the temp sub directory is checked in? If so, should the directory be named something else?

(There are some other temp directories further down as well)

[liamappelbe]

No, there's supposed to be gitignores preventing these from being added. Not sure how this was missed.

[dcharkes]

• ffigen has a dev dep on package:objective_c for testing. All the ObjC tests are disabled on linux and windows, but afaik there's no way of avoiding pulling in the dependency on those platforms. So I had to modify package:objective_c's build script to no-op on those platforms. Seems like a sub-optimal solution.

That is tracked in:

• [hooks] Exclude a platform from being built by dependency's build hook #2480

Mac CI failures are due to running the tests through package:coverage. Need to investigate why that's not finding the dylib.

That sounds like something we should fix before build hooks get to stable! Let me know if you need any help with this.

[dcharkes]

Very nice to see all the flutter boiler plate removed!

[dcharkes]

Can this be beta?
Or do you intend to wait to merge this PR until the next stable is out, and merge it as stable?

Maybe add a todo to flip it back to stable as soon as the next stable is released.

[liamappelbe]

Yeah, this is a temporary change so I can test on CI. I'll wait for stable and revert these changes before landing.

[goderbauer]

Since you removed the other temp files just double-checking: Is this file and pkgs/swiftgen/test/integration/temp/classes_output.dart supposed to be here?