[native aot] Unhandled exceptions are not printed to console

[jkotas]

Compile and run with nativeaot on current main:

throw new Exception("My unhandled exception");

Expected result

Unhandled exception message is printed to console.

Actual result

No message printed to console

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Issue Details

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Compile and run with nativeaot on current main:

throw new Exception("My unhandled exception");

Expected result

Unhandled exception message is printed to console.

Actual result

No message printed to console

Author:	jkotas
Assignees:	-
Labels:	area-NativeAOT-coreclr
Milestone:	-

[jkotas]

Looks like a regression from #88034. @janvorli Could you please take a look?

[janvorli]

The problem is really caused by the #88034, specifically by moving the

runtime/src/coreclr/nativeaot/Runtime.Base/src/System/Runtime/ExceptionHandling.cs

Lines 711 to 712 in fecf3ee

	prevControlPC = frameIter.ControlPC;
	prevOriginalPC = frameIter.OriginalControlPC;

from after to before the

runtime/src/coreclr/nativeaot/Runtime.Base/src/System/Runtime/ExceptionHandling.cs

Lines 716 to 717 in fecf3ee

	if (unwoundReversePInvoke)
	break;

It results in call to the UnhandledExceptionFailFastViaClasslib with prevOriginalPC that's one level up the call stack, in the native wmain. That further causes the InternalCalls.RhpGetClasslibFunctionFromCodeAddress to return null, as the address is not in managed code.

I can make this part of the change specific to coreclr, that fixes the problem. However, I would like to check what was the reason for moving it, it seems that for coreclr the only place where it matters is the arm64 code path here:

runtime/src/coreclr/nativeaot/Runtime.Base/src/System/Runtime/ExceptionHandling.cs

Lines 818 to 820 in fecf3ee

	#if TARGET_ARM64
	&& (frameIter.ControlPC == prevControlPC)
	#endif