Dart2Wasm async/async*/yield/yield* umbrella issue

[mkustermann]

There's a number of semantics issues with Dart2Wasm's implementation for async/async*/yield/yield* implementation (mostly async* related I believe). We use this tracking number in approvals & status files.

• Had to skip a number of tests that cause CI issues (purple bots) due to timeouts
• yield* desugaring doesn't handle errors correctly #52464
• ...

/cc @osa1

[osa1]

Current list of tests that are hanging:

• language/async_star/async_star_await_for_test
• language/async_star/async_star_cancel_test
• language/async_star/async_star_invalid_test/03
• language/async_star/async_star_test
• language/async_star/cancel_and_throw_in_finally_test
• language/async_star/cancel_test
• language/async_star/error_test
• language/async_star/no_cancel2_test
• language/async_star/no_cancel_test
• language/async_star/regression_fisk_test
• language/async_star/throw_in_catch_test
• language/async_star/yield_test
• language/async_star/yieldstar_test

https://dart-review.googlesource.com/c/sdk/+/354621 starts to skip these tests.

[whesse]

Please list all tests skipped by this issue, so it can be found when searching.

[osa1]

I started looking into why these fail. It takes time to find the root cause, but most of them involve error handling or cancellation (which I suspect may be relying on error handling). So I think it makes sense to start fixing with #52464.

[mkustermann]

After fixing test infra structure to recognize async tests, putting in a workaround for Chrome/V8 bug not reporting rethrow errors, we now have the following failures:

co19/Language/Expressions/Function_Invocation/async_generator_invokation_t04 RuntimeError (expected Pass)
co19/Language/Expressions/Function_Invocation/async_generator_invokation_t08 RuntimeError (expected Pass)
co19/Language/Statements/Yield_and_Yield_Each/Yield/execution_async_A03_t04 RuntimeError (expected Pass)
co19/Language/Statements/Yield_and_Yield_Each/Yield/execution_async_A03_t05 RuntimeError (expected Pass)
co19/Language/Statements/Yield_and_Yield_Each/Yield_Each/execution_async_A03_t12 RuntimeError (expected Pass)
co19/Language/Statements/Yield_and_Yield_Each/Yield_Each/execution_async_A03_t14 RuntimeError (expected Pass)
co19/Language/Statements/Yield_and_Yield_Each/Yield_Each/execution_async_A03_t15 RuntimeError (expected Pass)
co19/Language/Statements/Yield_and_Yield_Each/Yield_Each/execution_async_A03_t16 RuntimeError (expected Pass)
language/async/error_timing_test RuntimeError (expected Pass)
language/async/return_throw_test RuntimeError (expected Pass)
language/async_star/async_star_cancel_test RuntimeError (expected Pass)
language/async_star/cancel_and_throw_in_finally_test RuntimeError (expected Pass)
language/async_star/cancel_test RuntimeError (expected Pass)
language/async_star/regression_fisk_test RuntimeError (expected Pass)
language/async_star/throw_in_catch_test RuntimeError (expected Pass)
language/deferred/redirecting_factory_test RuntimeError (expected Pass)
language/regress/regress23244_test RuntimeError (expected Pass)
lib/async/async_await_sync_completer_test RuntimeError (expected Pass)
lib/async/stream_iterator_test RuntimeError (expected Pass)

are failing on configurations

dart2wasm-linux-chrome

[IchordeDionysos]

I'm currently running into this issue:

Yield statement in async function: YieldStatement(yield* combinedFolded;) (file:///Users/dennis/develop/flutter/app/lib/domain/use_cases/topics/get_summary_of_topics.dart:78:7)
#0      AsyncCodeGenerator.visitYieldStatement (package:dart2wasm/async.dart:1240)
#1      YieldStatement.accept (package:kernel/ast.dart:10496)
#2      _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#3      _YieldFinder.visitBlock (package:dart2wasm/async.dart:56)
#4      Block.accept (package:kernel/ast.dart:9252)
#5      _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#6      _YieldFinder.visitIfStatement (package:dart2wasm/async.dart:78)
#7      IfStatement.accept (package:kernel/ast.dart:10153)
#8      _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#9      _YieldFinder.visitBlock (package:dart2wasm/async.dart:56)
#10     Block.accept (package:kernel/ast.dart:9252)
#11     _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#12     _YieldFinder.visitBlock (package:dart2wasm/async.dart:56)
#13     Block.accept (package:kernel/ast.dart:9252)
#14     _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#15     _YieldFinder.visitTryCatch (package:dart2wasm/async.dart:116)
#16     TryCatch.accept (package:kernel/ast.dart:10270)
#17     _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#18     _YieldFinder.visitTryFinally (package:dart2wasm/async.dart:105)
#19     TryFinally.accept (package:kernel/ast.dart:10432)
#20     _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#21     _YieldFinder.visitBlock (package:dart2wasm/async.dart:56)
#22     Block.accept (package:kernel/ast.dart:9252)
#23     _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#24     _YieldFinder.visitBlock (package:dart2wasm/async.dart:56)
#25     Block.accept (package:kernel/ast.dart:9252)
#26     _YieldFinder.recurse (package:dart2wasm/async.dart:43)
#27     _YieldFinder.find (package:dart2wasm/async.dart:32)
#28     AsyncCodeGenerator._generateBodies (package:dart2wasm/async.dart:557)
#29     AsyncCodeGenerator.generateLambda (package:dart2wasm/async.dart:551)
#30     Translator.translate (package:dart2wasm/translator.dart:382)
#31     compileToModule (package:dart2wasm/compile.dart:151)
<asynchronous suspension>
#32     generateWasm (package:dart2wasm/generate_wasm.dart:21)

Example code:

Stream<String> call() async* {
  yield* combinedFolded; // errors here
}

Should this now be fixed, or should I open a new issue?

Version:

Flutter 3.20.0-11.0.pre.16 • channel [user-branch] • https://github.com/simpleclub-extended/flutter.git
Framework • revision 22cc113d16 (7 weeks ago) • 2024-02-17 23:46:10 +0000
Engine • revision e51d4f1e28
Tools • Dart 3.4.0 (build 3.4.0-153.0.dev) • DevTools 2.33.0-dev.6

[kevmoo]

@IchordeDionysos – please open a seperate issue!