Assert failure: pMD->IsCtor()

[BruceForstall]

Running 'PMI' on Dia2Lib.dll hits an assert. This causes the runtime superpmi-collect to fail the SuperPMI collect libraries pmi linux x64 checked collection job:

https://dev.azure.com/dnceng/internal/_build/results?buildId=2692581&view=logs&j=5562265b-363f-5c64-5cff-7b508c285721

To repro, build the https://github.com/dotnet/jitutils repo (clone, then run ./bootstrap.sh). Then, from a dotnet/runtime artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root directory:

~/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root$ ./corerun ~/gh/jitutils/bin/pmi.dll DRIVEALL Dia2Lib.dll
DRIVEALL: Invoking /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun /home/brucefo/gh/jitutils/bin/pmi.dll PREPALL Dia2Lib.dll 0
PrepAll for Dia2Lib
Start type Dia2Lib.DiaSourceClass
PREPALL type# 0 method# 0 Dia2Lib.DiaSourceClass::get_lastError
Assert failure(PID 71552 [0x00011780], Thread: 71552 [0x11780]): pMD->IsCtor()    File: /home/brucefo/gh/runtime/src/coreclr/vm/ecall.cpp:350    Image: /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun
Current Method: 0 nextMethodToPrep: 1
DRIVEALL: Invoking /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun /home/brucefo/gh/jitutils/bin/pmi.dll PREPALL Dia2Lib.dll 2
PrepAll for Dia2Lib
Start type Dia2Lib.DiaSourceClass
PREPALL type# 0 method# 2 Dia2Lib.DiaSourceClass::loadAndValidateDataFromPdb
Assert failure(PID 71568 [0x00011790], Thread: 71568 [0x11790]): pMD->IsCtor()    File: /home/brucefo/gh/runtime/src/coreclr/vm/ecall.cpp:350    Image: /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun
Current Method: 2 nextMethodToPrep: 3
DRIVEALL: Invoking /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun /home/brucefo/gh/jitutils/bin/pmi.dll PREPALL Dia2Lib.dll 4
PrepAll for Dia2Lib
Start type Dia2Lib.DiaSourceClass
PREPALL type# 0 method# 4 Dia2Lib.DiaSourceClass::loadDataFromIStream
Assert failure(PID 71579 [0x0001179b], Thread: 71579 [0x1179b]): pMD->IsCtor()    File: /home/brucefo/gh/runtime/src/coreclr/vm/ecall.cpp:350    Image: /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun
Current Method: 4 nextMethodToPrep: 5
DRIVEALL: Invoking /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun /home/brucefo/gh/jitutils/bin/pmi.dll PREPALL Dia2Lib.dll 6
PrepAll for Dia2Lib
Start type Dia2Lib.DiaSourceClass
PREPALL type# 0 method# 6 Dia2Lib.DiaSourceClass::loadDataFromCodeViewInfo
Assert failure(PID 71590 [0x000117a6], Thread: 71590 [0x117a6]): pMD->IsCtor()    File: /home/brucefo/gh/runtime/src/coreclr/vm/ecall.cpp:350    Image: /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun
Current Method: 6 nextMethodToPrep: 7
DRIVEALL: Invoking /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun /home/brucefo/gh/jitutils/bin/pmi.dll PREPALL Dia2Lib.dll 8
PrepAll for Dia2Lib
Start type Dia2Lib.DiaSourceClass
PREPALL type# 0 method# 8 Dia2Lib.DiaSourceClass::IDiaDataSource3_get_lastError
Assert failure(PID 71602 [0x000117b2], Thread: 71602 [0x117b2]): pMD->IsCtor()    File: /home/brucefo/gh/runtime/src/coreclr/vm/ecall.cpp:350    Image: /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun
Current Method: 8 nextMethodToPrep: 9
DRIVEALL: Invoking /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun /home/brucefo/gh/jitutils/bin/pmi.dll PREPALL Dia2Lib.dll 10
PrepAll for Dia2Lib
Start type Dia2Lib.DiaSourceClass
PREPALL type# 0 method# 10 Dia2Lib.DiaSourceClass::IDiaDataSource3_loadAndValidateDataFromPdb
Assert failure(PID 71614 [0x000117be], Thread: 71614 [0x117be]): pMD->IsCtor()    File: /home/brucefo/gh/runtime/src/coreclr/vm/ecall.cpp:350    Image: /home/brucefo/gh/runtime/artifacts/tests/coreclr/linux.x64.Checked/Tests/Core_Root/corerun
Current Method: 10 nextMethodToPrep: 11

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[AaronRobinsonMSFT]

I see what is going on here, but it involves the application of MethodImpl(MethodImplOptions.InternalCall) to interface methods - which hasn't been needed since at least .NET Framework 3.5. I don't see why this hasn't been triggering for a long time.

@jkotas Can you shed some light on the code path below? The path is being taken for a non-ctor MethodDesc, a COM interface getter in this case. TlbImp always marks interface methods with the MethodImplOptions.InternalCall so I'm unclear why this assert isn't always triggered.

runtime/src/coreclr/vm/ecall.cpp

Lines 339 to 354 in 5d3fe14

	// COM imported classes have special constructors
	if (pMT->IsComObjectType()
	#ifdef FEATURE_COMINTEROP
	&& (g_pBaseCOMObject == NULL || pMT != g_pBaseCOMObject)
	#endif // FEATURE_COMINTEROP
	)
	{
	if (pfSharedOrDynamicFCallImpl)
	*pfSharedOrDynamicFCallImpl = TRUE;
	// This has to be tlbimp constructor
	_ASSERTE(pMD->IsCtor());
	// FCComCtor does not need to be in the fcall hashtable since it does not erect frame.
	return GetEEFuncEntryPoint(FCComCtor);
	}

[AaronRobinsonMSFT]

Just to be clear, this seems to work if I remove the assert. I'm unclear why this work at all since this is always returning FCComCtor.

[jkotas]

What's the stacktrace of the failure?

Regular interface methods are abstract. They do not have an implementation, and no code should be asking for the implementation. I think that the problem is somewhere in the code that ends up calling this method.

[jkotas]

If this is hit on Linux only, it is likely inconsistent FEATURE_COMINTEROP ifdefs.

We have the whole special handling ifdefed out here:

runtime/src/coreclr/vm/methodtablebuilder.cpp

Lines 3163 to 3178 in 5d3fe14

	#ifdef FEATURE_COMINTEROP
	if (fIsClassComImport || bmtProp->fComEventItfType)
	{
	// ComImport classes have methods which are just used
	// for implementing all interfaces the class supports
	type = mcComInterop;
	// constructor is special
	if (IsMdRTSpecialName(dwMemberAttrs))
	{
	// Note: Method name (.ctor) will be checked in code:ValidateMethods
	type = mcFCall;
	}
	}
	else
	#endif //FEATURE_COMINTEROP

, but it is partially enabled in the ecall.cpp code that you have linked.

[AaronRobinsonMSFT]

If this is hit on Linux only, it is likely inconsistent FEATURE_COMINTEROP ifdefs.

Right, I see the issue now. Thanks.