Compiler crash with optional `Finalizable` parameter

[blaugold]

The following code causes a compiler crash when compiled with dart compile exe:

class A implements Finalizable {}

void b([A? a]) {}

void main() {
  b();
}

Here is the stacktrace generated when building a Flutter app that contains the above code:

../../third_party/dart/runtime/vm/compiler/frontend/kernel_binary_flowgraph.cc: 5839: error: Unexpected tag 106
version=2.18.0-256.0.dev (dev) (Tue Jul 5 05:08:29 2022 -0700) on "macos_x64"
pid=13001, thread=259, isolate_group=isolate(0x7fb64b01c800), isolate=(nil)(0x0)
isolate_instructions=0, vm_instructions=0
  pc 0x0000000102b90885 fp 0x0000000309dde550 dart::Profiler::DumpStackTrace(void*)+0x85
  pc 0x00000001029d5404 fp 0x0000000309dde630 dart::Assert::Fail(char const*, ...) const+0x84
  pc 0x0000000102e32244 fp 0x0000000309dde680 dart::kernel::StreamingFlowGraphBuilder::BuildReachabilityFence()+0x1e4
  pc 0x0000000102e29687 fp 0x0000000309dde710 dart::kernel::StreamingFlowGraphBuilder::BuildStaticInvocation(dart::TokenPosition*)+0x397
  pc 0x0000000102e23294 fp 0x0000000309dde760 dart::kernel::StreamingFlowGraphBuilder::BuildStatement(dart::TokenPosition*)+0xc4
  pc 0x0000000102e2c28a fp 0x0000000309dde7c0 dart::kernel::StreamingFlowGraphBuilder::BuildBlock(dart::TokenPosition*)+0x9a
  pc 0x0000000102e24667 fp 0x0000000309dde860 dart::kernel::StreamingFlowGraphBuilder::BuildFunctionBody(dart::Function const&, dart::LocalVariable*, bool)+0xf7
  pc 0x0000000102e24da9 fp 0x0000000309ddea10 dart::kernel::StreamingFlowGraphBuilder::BuildGraphOfFunction(bool)+0x329
  pc 0x0000000102e25304 fp 0x0000000309ddeb00 dart::kernel::StreamingFlowGraphBuilder::BuildGraph()+0x164
  pc 0x0000000102e37a93 fp 0x0000000309ddedd0 dart::kernel::FlowGraphBuilder::BuildGraph()+0x73
  pc 0x0000000102db3934 fp 0x0000000309ddf300 dart::CallSiteInliner::TryInliningImpl(dart::Function const&, dart::Array const&, dart::InlinedCallData*, bool)+0xb04
  pc 0x0000000102da8c66 fp 0x0000000309ddf3a0 dart::CallSiteInliner::TryInlining(dart::Function const&, dart::Array const&, dart::InlinedCallData*, bool)+0xf6
  pc 0x0000000102db72fb fp 0x0000000309ddf4a0 dart::CallSiteInliner::InlineStaticCalls()+0x5cb
  pc 0x0000000102dae515 fp 0x0000000309ddf5c0 dart::CallSiteInliner::InlineCalls()+0x255
  pc 0x0000000102dae15b fp 0x0000000309ddf6c0 dart::FlowGraphInliner::Inline()+0x1db
  pc 0x0000000102e06cb2 fp 0x0000000309ddf730 dart::CompilerPass_Inlining::DoBody(dart::CompilerPassState*) const+0x52
  pc 0x0000000102e0593f fp 0x0000000309ddf800 dart::CompilerPass::Run(dart::CompilerPassState*) const+0x1af
  pc 0x0000000102e05e19 fp 0x0000000309ddf830 dart::CompilerPass::RunPipeline(dart::CompilerPass::PipelineMode, dart::CompilerPassState*)+0xa9
  pc 0x0000000102cfeb0f fp 0x0000000309ddfef0 dart::PrecompileParsedFunctionHelper::Compile(dart::CompilationPipeline*)+0x4ef
  pc 0x0000000102cff602 fp 0x0000000309de0580 dart::PrecompileFunctionHelper(dart::Precompiler*, dart::CompilationPipeline*, dart::Function const&, bool)+0x322
  pc 0x0000000102cfa6c4 fp 0x0000000309de0680 dart::Precompiler::CompileFunction(dart::Precompiler*, dart::Thread*, dart::Zone*, dart::Function const&)+0x174
  pc 0x0000000102cf7d30 fp 0x0000000309de0720 dart::Precompiler::ProcessFunction(dart::Function const&)+0xf0
  pc 0x0000000102cf2564 fp 0x0000000309de0780 dart::Precompiler::Iterate()+0xa4
  pc 0x0000000102cecd00 fp 0x0000000309de0ed0 dart::Precompiler::DoCompileAll()+0x12e0
  pc 0x0000000102ceb99b fp 0x0000000309de1330 dart::Precompiler::CompileAll()+0xbb
  pc 0x0000000102ebab8f fp 0x0000000309de14a0 Dart_Precompile+0x17f
  pc 0x00000001029ccf38 fp 0x0000000309de1630 dart::bin::main(int, char**)+0x9a8
  pc 0x000000020336b51e fp 0x0000000309de1740 Unknown symbol
-- End of DumpStackTrace
=== Crash occured when compiling package:finalizable_issue_repro/main.dart_::_main in AOT mode in Inlining pass
package:finalizable_issue_repro/main.dart:1
*** BEGIN CFG
Inlining
==== package:finalizable_issue_repro/main.dart_::_main (RegularFunction)
package:finalizable_issue_repro/main.dart:1
B0[graph]:0 {
      v0 <- Constant(#null) T{Null?}

}
B1[function entry]:2
    CheckStackOverflow:8(stack=0, loop=0)
    DebugStepCheck:10()
    StaticCall:12( b<0> )
    StaticCall:14( runApp<0> )
    DebugStepCheck:16()
    Return:18(v0)
*** END CFG

Flutter 3.1.0-0.0.pre.1505 • channel master • https://github.com/flutter/flutter.git
Framework • revision 39a38b7882 (5 hours ago) • 2022-07-05 12:34:08 -0400
Engine • revision 8197dec7e2
Tools • Dart 2.18.0 (build 2.18.0-256.0.dev) • DevTools 2.15.0

[mraleph]

/cc @dcharkes

[dcharkes]

Thanks for reporting @blaugold!
I can reproduce this on master.
I have a fix ready at https://dart-review.googlesource.com/c/sdk/+/250744.

[dcharkes]

@blaugold are you in need of a cherry pick to stable for this? Or are you always running on master?

[blaugold]

Thanks for the quick fix. It would be great to have the fix in stable, since this issue was found in a package that is published to pub.dev.