Support for FFI calls with `@Native external` functions through Native assets on MacOS and iOS. This enables bundling native code without any build-system boilerplate code.
For more info see:
* https://github.com/flutter/flutter/issues/129757
### Implementation details for MacOS and iOS.
Dylibs are bundled by (1) making them fat binaries if multiple architectures are targeted, (2) code signing these, and (3) copying them to the frameworks folder. These steps are done manual rather than via CocoaPods. CocoaPods would have done the same steps, but (a) needs the dylibs to be there before the `xcodebuild` invocation (we could trick it, by having a minimal dylib in the place and replace it during the build process, that works), and (b) can't deal with having no dylibs to be bundled (we'd have to bundle a dummy dylib or include some dummy C code in the build file).
The dylibs are build as a new target inside flutter assemble, as that is the moment we know what build-mode and architecture to target.
The mapping from asset id to dylib-path is passed in to every kernel compilation path. The interesting case is hot-restart where the initial kernel file is compiled by the "inner" flutter assemble, while after hot restart the "outer" flutter run compiled kernel file is pushed to the device. Both kernel files need to contain the mapping. The "inner" flutter assemble gets its mapping from the NativeAssets target which builds the native assets. The "outer" flutter run get its mapping from a dry-run invocation. Since this hot restart can be used for multiple target devices (`flutter run -d all`) it contains the mapping for all known targets.
### Example vs template
The PR includes a new template that uses the new native assets in a package and has an app importing that. Separate discussion in: https://github.com/flutter/flutter/issues/131209.
### Tests
This PR adds new tests to cover the various use cases.
* dev/devicelab/bin/tasks/native_assets_ios.dart
* Runs an example app with native assets in all build modes, doing hot reload and hot restart in debug mode.
* dev/devicelab/bin/tasks/native_assets_ios_simulator.dart
* Runs an example app with native assets, doing hot reload and hot restart.
* packages/flutter_tools/test/integration.shard/native_assets_test.dart
* Runs (incl hot reload/hot restart), builds, builds frameworks for iOS, MacOS and flutter-tester.
* packages/flutter_tools/test/general.shard/build_system/targets/native_assets_test.dart
* Unit tests the new Target in the backend.
* packages/flutter_tools/test/general.shard/ios/native_assets_test.dart
* packages/flutter_tools/test/general.shard/macos/native_assets_test.dart
* Unit tests the native assets being packaged on a iOS/MacOS build.
It also extends various existing tests:
* dev/devicelab/bin/tasks/module_test_ios.dart
* Exercises the add2app scenario.
* packages/flutter_tools/test/general.shard/features_test.dart
* Unit test the new feature flag.
* Update packages.
* Add many more global analyses.
* Catch trailing spaces and trailing newlines in all text files.
Before we were only checking newly added files, but that means we
missed some.
* Port the trailing spaces logic to work on Windows too.
* Correct all the files with trailing spaces and newlines.
* Refactor some of the dev/bots logic into a utils.dart library.
Notably, the "exit" and "print" shims for testing are now usable
from test.dart, analyze.dart, and run_command.dart.
* Add an "exitWithError" function that prints the red lines and
then exits. This is the preferred way to exit from test.dart,
analyze.dart, and run_command.dart.
* More consistency in the output of analyze.dart.
* Refactor analyze.dart to use the _allFiles file enumerating logic
more widely.
* Add some double-checking logic to the _allFiles logic to catch
cases where changes to that logic end up catching fewer files
than expected (helps prevent future false positives).
* Add a check to prevent new binary files from being added to
the repository. Grandfather in the binaries that we've already
added.
* Update all the dependencies (needed because we now import crypto in
dev/bots/analyze.dart).
* Update project.pbxproj files to say Flutter rather than Chromium
Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.
* Update the copyright notice checker to require a standard notice on all files
* Update copyrights on Dart files. (This was a mechanical commit.)
* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.
Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).
* Clean up the copyrights in non-Dart files. (Manual edits.)
Also, make sure templates don't have copyrights.
* Fix some more ORGANIZATIONNAMEs
Updates the Podfile template to use the CocoaPod disable_input_output_paths installation option which prevents the [CP] Embed Pods Frameworks build phase from outputting the Flutter.framework files.
Updates the Podfile template to use the CocoaPod disable_input_output_paths installation option which prevents the [CP] Embed Pods Frameworks build phase from outputting the Flutter.framework files.
Updates the Podfile template to use the CocoaPod disable_input_output_paths installation option which prevents the [CP] Embed Pods Frameworks build phase from outputting the Flutter.framework files.
* move flutter_assets to App.framework
* Roll engine to 05fee4eeee0ff6b219b1fcc394371e5f6963cc46
05fee4eee Update default flutter_assets path for iOS embedding (flutter/engine#7518)
02205db01 Roll src/third_party/skia 5d052dac3ac1..02738a86e5fd (4 commits) (flutter/engine#7541)
af907c074 Roll src/third_party/skia 5c7a3ac0e214..5d052dac3ac1 (7 commits) (flutter/engine#7540)
dde286673 IWYU to get SkFontMetrics (flutter/engine#7539)
* Fix xcode_backend.sh script to support add2app
* Fix ios deployment target. Too old for new Xcode.
* Fix ios host app
* Register plugins with Flutter view
* Prototype
* Fix paths to Flutter library resources
* Invoke pod install as necessary for materialized modules
* Add devicelab test for module use on iOS
* Remove debug output
* Rebase, reame materialize editable
* Add devicelab test editable iOS host app
* Removed add2app test section
