pigeon

• [dart] Fixes JNI typed data arrays being backed by native memory that is freed when the isolate that read them exits.
• [dart] Fixes a potential use-after-free when reading FFI typed data arrays.
• Updates native interop guides and migration skill for jnigen 1.0.0 and current tooling requirements.

[pigeon] Fix NSnumber edge cases and null value bug (#12997)

Fixes flutter/flutter#193266
Fixes two Swift FFI value serialization bugs in `SwiftGenerator`:

1. **`CFBoolean` and floating-point `NSNumber` bridging in `wrapNumber`**: When an Objective-C boolean (`__NSCFBoolean` / `CFBoolean`) or a whole-number floating-point `NSNumber` (such as `3.0` returned from `UserDefaults.object(forKey:)` or `NSDictionary`) is boxed inside `Any`, Swift's dynamic `as? Int` cast succeeds before reaching `case let value as Double:` or `case let value as Bool:`. `wrapNumber` now checks `CFGetTypeID(number as CFTypeRef) == CFBooleanGetTypeID()` (`type: 3`) and `CFNumberIsFloatType(nsNumber)` (`type: 2`) prior to switching on numeric types, matching `FlutterStandardCodec` behavior.
2. **Dictionary value `isNullish` check in `writeValue`**: Fixes a typo in `writeValue` where dictionary serialization checked `isNullish(key)` instead of `isNullish(value)` when serializing dictionary values.

Fixes https://github.com/flutter/flutter/issues/<ISSUE_NUMBER>

## Pre-Review Checklist

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• [swift] Uses isNullish to check for null and NSNull in non-null Flutter API returns.
• Updates minimum supported SDK version to Flutter 3.41/Dart 3.11.

• [swift] Fixes a crash when a Flutter API returns null for a non-null return value and the null arrives as NSNull.

adds main actor annotation to async flutter api methods in swift.

fixes flutter/flutter#192199

This PR introduces optional Native Interop to Pigeon, enabling direct communication between Dart and native code without the overhead of traditional MethodChannel serialization. It leverages FFI (Foreign Function Interface) for Swift (iOS/macOS) and JNI (Java Native Interface) for Kotlin (Android).

This represents a significant architectural shift, moving from message-based passing to direct memory sharing and function calls. It also updates the concurrency model for asynchronous methods, moving from completion handlers/callbacks to modern language features: async/await in Swift and Coroutines in Kotlin.

Generators Covered

Swift Generator: Updated to support FFI bindings and async/await for asynchronous methods.
Kotlin Generator: Updated to support JNI bindings and Kotlin Coroutines for asynchronous methods.
Dart Generator: Updated to handle the generated interop bindings on the Dart side.

What's In Scope

1. Infrastructure: Added core support for useFfi and useJni options.
2. Automation: Implemented multi-step generation flows that automatically invoke jnigen and ffigen to produce final bindings.
3. Config Generation: Added jnigen_config_generator.dart and ffigen_config_generator.dart to generate the necessary configuration files for the external tools.
4. Documentation: Added a detailed native_interop_guide.md explaining prerequisites, setup, and usage.
   Tests: Added ni_tests.dart and associated generated files and integration tests to verify the feature.

What's Out of Scope

1. Other Languages: This PR specifically targets Swift and Kotlin for the Native Interop feature. Support for Objective-C, C++, and GObject is not included in this interop implementation, and may not be in the future.
2. Performance Optimization for Complex Classes: As noted in the guide, there is a known performance regression when transferring complex classes with many fields compared to MethodChannel Pigeon. This PR delivers the functional infrastructure, but optimizing this specific case is left for follow-up work.
3. Non-instant released data. Currently all data that is sent over host or flutter api surfaces is converted to the correct shape and type for the language it is moving toward and the data created in the other language is then discarded. This presents some inefficiencies and potential workflows that are not yet available.

work toward flutter/flutter#182230
design doc flutter/flutter#181430

fixes flutter/flutter#164297

Adds support for modern async method styles in swift and kotlin. This is now the default. Also adds a new annotation AsyncCallback that reverts to the old style.

precursor to #11352

Part of fixing flutter/flutter#183945.

Regenerating pigeon files will fix issue.

Pre-Review Checklist

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

• Updates analyzer dependency to support versions 13 and 14.
• Updates minimum Dart SDK constraint to 3.11.0.

• Adds support for sharing constants across platforms.

• Adds support for empty data classes.

• Reports a clear error when an input file uses an enhanced enum (one with a constructor, fields, methods, or arguments on its values), instead of silently generating incorrect output.

• [dart] Adds usage documentation to generated event channel methods, and emits the user's documentation comments on them.

• [swift] Adds CaseIterable conformance to generated enums.

• Breaking Change Overrides toString (or equivalent) methods on generated data classes
  • This can conflict with custom description implementations in Swift.
• [swift] Updates isNullish to handle double nested Any? values.
• Updates minimum supported SDK version to Flutter 3.38/Dart 3.10.

• [kotlin] Updates generated error class to inherit from RuntimeException instead of Throwable, for better Java interoperability.

• Updates analyzer dependency to support versions 10 through 12.

• Updates analyzer dependency to support version 10.

• Fixes dartdoc comments that accidentally used HTML.

• Optimizes and improves data class equality and hashing.
• Changes hashing and equality methods to behave consistently across platforms.
• Adds equality methods to previously unsupported languages.

• Produces a helpful error message when a method return type is missing or an unsupported type, such as a function type or record type.

• [dart] Improves nullability-handling in generated code.

• [kotlin] Adds option to add javax.annotation.Generated annotation.

• Dramatically reduces the number of File write operations sent to the operating system during code-generation. This improves performance of IDEs and the Dart analysis server.

• [dart] Reduces much duplication in reply-handling code.

• Makes some internal class constructors constant.

• [objc] Updates to use module imports.

• [kotlin] Fixes a "bridge method" warning when implementing an event stream handler.

• [swift][kotlin] Fixes crash that occurs when an object that is removed from the instance manager calls to Dart.

• [dart] Fixes error from constructor parameter sharing name with attached field for a ProxyApi.
• Updates minimum supported SDK version to Flutter 3.35/Dart 3.9.

• [kotlin] Fixes compilation error with unbounded type parameter for InstanceManager.

• Updates supported analyzer versions to 8.x or 9.x.
• Updates minimum supported SDK version to Flutter 3.32/Dart 3.8.

• Deprecates dartHostTestHandler and dartTestOut.
  • If you have a use case where this cannot easily be replaced with a mock or fake of the generated Dart API, please provide details in https://github.com/flutter/flutter/issues/178322.

• [kotlin] Serialize custom enums as Long instead of Int to avoid ClassCastException on decoding.

• Adds compatibility with analyzer 8.x.

• [kotlin] Removes all containsKey and replaces with contains.

• [kotlin] Fixes support for classes that override equals and hashCode for ProxyApis.
• [kotlin] Adds error message log when a new Dart proxy instance fails to be created.
• Updates minimum supported SDK version to Flutter 3.29/Dart 3.7.

• Improves documentation of ProxyApi annotation and internal Dart ProxyAPI helper functions.
• Moves helper functions for generating Dart portion of ProxyAPIs.

• Breaking Change [dart] Changes name of constructors used to create subclasses of ProxyApis to pigeon_**original_name**.
• [dart] Adds ProxyApi overrides classes to be used in Flutter unit tests.

• [dart] Changes the default InstanceManager and its initialization to no longer make a message call when used in a Flutter unit test.

• [gobject] Adds type id constants in header files so that they can be used by the user.
• Updates minimum supported SDK version to Flutter 3.27/Dart 3.6.

• [dart] Fixes null pointer crashes/exceptions caused by premature finalization of Dart instances for ProxyApis.

• [kotlin] Fixes Kotlin InstanceManager not properly removing callbacks from handler.
• [kotlin] Fixes SyntheticAccessor lint caused by private utility methods.

• [swift] Adds equality methods to generated data classes.
• [dart, kotlin] Shortens equality methods.

• [kotlin] Adds equality methods to generated data classes.

• [dart] Adds equality methods to generated data classes.

• Breaking Change Removes oneLanguage field from PigeonOptions.
• Separates internal options classes from user facing options.
• Adds mergeDefinitionFileOptions parameter to runWithOptions method.
• Relocates injectOverflowTypes to non-public facing method.

• Updates compileSdk 34 to flutter.compileSdkVersion.

• [dart] Fixes potential race condition caused by a ProxyApi constructor message call being made in an async method.

• Adjusts task queues to use a shared task queue for all methods in a single API instance, to give the same ordering guarantees as non-task-queue usage.
• [swift] Adds task queue support to the Swift generator.

• [swift, kotlin] Adds an error message when a ProxyAPI callback method that returns a non-null value is nullable.
• [swift, kotlin] Adds an error message in the ProxyApiBaseCodec when an instance could not be retrieved when reading a value.
• [swift, kotlin] Fixes ProxyAPI platform APIs not calling completion when creating a new instance.

• [kotlin, swift] Adds annotation options to omit shared classes used in Event Channels.

• Breaking Change Relocates some files in lib that were not intended for direct client use to lib/src.

• Breaking Change [swift] Fixes a compile error about PigeonError's sendability conformance in Swift 6.
  • PigeonError's init now requires the "details" argument to be Sendable.

• [dart] Fixes bug with multi-instance event channel support.

• Adds compatibility with analyzer 7.x.*.

• Updates README to discuss best practices for using Pigeon-generated code.