CFE crash: Iterables do not have same length.

[aartbik]

While experimenting with DartFuzz generalizations, I encountered the following crash in the CFE. It is possible the generated Dart program did not make sense at this point (attached as fuzz_fe.dart.txt, just remove the txt), but having the CFE crash seems undesirable in any case.

$ dart fuzz_fe.dart 
Crash when compiling file:///usr/local/google/home/ajcbik/Repo/DART/fuzz_fe.dart,
at character offset 39280:
Invalid argument(s): Iterables do not have same length.
#0      MapBase._fillMapWithIterables (dart:collection/maps.dart:91:7)
#1      new LinkedHashMap.fromIterables (dart:collection/linked_hash_map.dart:141:13)
#2      Substitution.fromPairs (package:kernel/type_algebra.dart:214:13)
#3      BodyBuilder.resolveRedirectingFactoryTargets (package:front_end/src/fasta/kernel/body_builder.dart:957:52)
#4      BodyBuilder.finishFunction (package:front_end/src/fasta/kernel/body_builder.dart:901:5)
#5      DietListener.listenerFinishFunction (package:front_end/src/fasta/source/diet_listener.dart:803:14)
#6      DietListener.buildFunctionBody (package:front_end/src/fasta/source/diet_listener.dart:837:7)
#7      DietListener.endMethod (package:front_end/src/fasta/source/diet_listener.dart:587:5)
#8      Parser.parseMethod (package:front_end/src/fasta/parser/parser.dart:3067:14)
#9      Parser.parseClassOrMixinMemberImpl (package:front_end/src/fasta/parser/parser.dart:2933:15)
#10     Parser.parseClassOrMixinBody (package:front_end/src/fasta/parser/parser.dart:2738:15)
#11     Parser.parseClass (package:front_end/src/fasta/parser/parser.dart:1762:13)
#12     Parser.parseClassOrNamedMixinApplication (package:front_end/src/fasta/parser/parser.dart:1722:14)
#13     Parser.parseTopLevelKeywordDeclaration (package:front_end/src/fasta/parser/parser.dart:574:14)
#14     Parser.parseTopLevelDeclarationImpl (package:front_end/src/fasta/parser/parser.dart:466:14)
#15     Parser.parseUnit (package:front_end/src/fasta/parser/parser.dart:349:15)
#16     SourceLoader.buildBody (package:front_end/src/fasta/source/source_loader.dart:262:14)
<asynchronous suspension>
#17     Loader.buildBodies (package:front_end/src/fasta/loader.dart:182:15)
<asynchronous suspension>
#18     KernelTarget.buildComponent.<anonymous closure> (package:front_end/src/fasta/kernel/kernel_target.dart:298:20)
<asynchronous suspension>
#19     withCrashReporting (package:front_end/src/fasta/crash.dart:122:24)
<asynchronous suspension>
#20     KernelTarget.buildComponent (package:front_end/src/fasta/kernel/kernel_target.dart:296:12)
<asynchronous suspension>
#21     generateKernelInternal.<anonymous closure> (package:front_end/src/kernel_generator_impl.dart:145:38)
<asynchronous suspension>
#22     withCrashReporting (package:front_end/src/fasta/crash.dart:122:24)
<asynchronous suspension>
#23     generateKernelInternal (package:front_end/src/kernel_generator_impl.dart:55:10)
<asynchronous suspension>
#24     generateKernel.<anonymous closure> (package:front_end/src/kernel_generator_impl.dart:40:18)
<asynchronous suspension>
#25     CompilerContext.runWithOptions.<anonymous closure> (package:front_end/src/fasta/compiler_context.dart:134:20)
<asynchronous suspension>
#26     CompilerContext.runInContext.<anonymous closure>.<anonymous closure> (package:front_end/src/fasta/compiler_context.dart:122:46)
#27     new Future.sync (dart:async/future.dart:224:31)
#28     CompilerContext.runInContext.<anonymous closure> (package:front_end/src/fasta/compiler_context.dart:122:19)
#29     _rootRun (dart:async/zone.dart:1124:13)
#30     _CustomZone.run (dart:async/zone.dart:1021:19)
#31     _runZoned (dart:async/zone.dart:1516:10)
#32     runZoned (dart:async/zone.dart:1463:12)
#33     CompilerContext.runInContext (package:front_end/src/fasta/compiler_context.dart:121:12)
#34     CompilerContext.runWithOptions (package:front_end/src/fasta/compiler_context.dart:132:10)
#35     generateKernel (package:front_end/src/kernel_generator_impl.dart:39:32)
<asynchronous suspension>
#36     kernelForComponent (package:front_end/src/api_prototype/kernel_generator.dart:83:17)
<asynchronous suspension>
#37     SingleShotCompilerWrapper.compileInternal (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:267:11)
<asynchronous suspension>
#38     Compiler.compile.<anonymous closure> (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:144:31)
<asynchronous suspension>
#39     new Future.<anonymous closure> (dart:async/future.dart:176:37)
#40     _rootRun (dart:async/zone.dart:1120:38)
#41     _CustomZone.run (dart:async/zone.dart:1021:19)
#42     _CustomZone.runGuarded (dart:async/zone.dart:923:7)
#43     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:963:23)
#44     _rootRun (dart:async/zone.dart:1124:13)
#45     _CustomZone.run (dart:async/zone.dart:1021:19)
#46     _CustomZone.bindCallback.<anonymous closure> (dart:async/zone.dart:947:23)
#47     Timer._createTimer.<anonymous closure> (dart:async/runtime/lib/timer_patch.dart:21:15)
#48     _Timer._runTimers (dart:isolate/runtime/lib/timer_impl.dart:382:19)
#49     _Timer._handleMessage (dart:isolate/runtime/lib/timer_impl.dart:416:5)
#50     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/lib/isolate_patch.dart:171:12)

[aartbik]

fuzz_fe.dart.txt

[aartbik]

I see this same crash when fuzzing spread operators. Please have a look.
@a-siva

[aartbik]

Is this a known issue too? I am seeing this more and more while trying to come up with new spead/control-flow collection tests.

[aartbik]

It happens a lot less now than before, but it remains the second showstopper for long running fuzz testing sessions:

Isolate (/tmp/dart_fuzzBVYFET) JIT-O3-DebugX64 - JIT-STACKTRACEEVERY-ReleaseX64: !DIVERGENCE! 1.6:3057496967 (output=false)

fail1:
Crash when compiling file:///tmp/dart_fuzzBVYFET/fuzz.dart,
at character offset 135696:
Invalid argument(s): Iterables do not have same length.
#0      MapBase._fillMapWithIterables (dart:collection/maps.dart:85:7)
#1      new LinkedHashMap.fromIterables (dart:collection/linked_hash_map.dart:127:13)
#2      Substitution.fromPairs (package:kernel/type_algebra.dart:214:13)
#3      BodyBuilder.resolveRedirectingFactoryTargets (package:front_end/src/fasta/kernel/body_builder.dart:966:52)
#4      BodyBuilder.finishFunction (package:front_end/src/fasta/kernel/body_builder.dart:910:5)
#5      DietListener.listenerFinishFunction (package:front_end/src/fasta/source/diet_listener.dart:803:14)
#6      DietListener.buildFunctionBody (package:front_end/src/fasta/source/diet_listener.dart:837:7)
#7      DietListener.endMethod (package:front_end/src/fasta/source/diet_listener.dart:587:5)
#8      Parser.parseMethod (package:front_end/src/fasta/parser/parser.dart:3102:14)
#9      Parser.parseClassOrMixinMemberImpl (package:front_end/src/fasta/parser/parser.dart:2968:15)
#10     Parser.parseClassOrMixinBody (package:front_end/src/fasta/parser/parser.dart:2773:15)
#11     Parser.parseClass (package:front_end/src/fasta/parser/parser.dart:1757:13)
#12     Parser.parseClassOrNamedMixinApplication (package:front_end/src/fasta/parser/parser.dart:1717:14)
#13     Parser.parseTopLevelKeywordDeclaration (package:front_end/src/fasta/parser/parser.dart:569:14)
#14     Parser.parseTopLevelDeclarationImpl (package:front_end/src/fasta/parser/parser.dart:461:14)
#15     Parser.parseUnit (package:front_end/src/fasta/parser/parser.dart:344:15)
#16     SourceLoader.buildBody (package:front_end/src/fasta/source/source_loader.dart:272:14)
<asynchronous suspension>

[chloestefantsova]

Not sure about this one. Will be investigating it on Monday.

Thanks for the repro!

[chloestefantsova]

Proposed fix: https://dart-review.googlesource.com/c/sdk/+/98355. With it I was able to compile the repro fuzz_fe.dart without exceptions.