Enhanced Stack Frames with Native AOT

[jamescrosswell]

Continuing on from #3322 we need to implement Michal's other suggetions:

In the end, someone will need to do the work to enable the AOT/trim/single file safety analyzers and address all the warnings, but this is enough to have a golden path that makes sample/StackTrace project produce the same results under native AOT as under JIT.

Necessary fixes:

• GetMethodBody under AOT throws. This will not return anything useful under Mono with ILStrip either. The code simply needs to deal with it.
• Runtime reflection stack doesn't guarantee referential equality of MemberInfos (except for TypeInfo). This is also true on JIT-based runtimes, but there's even less caching on native AOT. Use operator ==.
• The reflection to read TupleElementNamesAttribute is trim-unfriendly and cannot be analyzed. Replace with no-reflection.
• Some fallout from the previous point because the nullable annotations on the thing returned by reflection were wrong.

Finally we should be able to simplify this:

sentry-dotnet/src/Sentry/Internal/DebugStackTrace.cs

Lines 179 to 181 in 233e95b

	var frames = (!AotHelper.IsNativeAot && _options.StackTraceMode == StackTraceMode.Enhanced)
	? EnhancedStackTrace.GetFrames(stackTrace).Select(p => new RealStackFrame(p))
	: stackTrace.GetFrames().Select(p => new RealStackFrame(p));

Also note Vitek Karas' guidance from Discord:

As noted in the PR, the code in that package will have problems in other cases which are not NativeAOT related - for example the GetMethodBody() will not work in some cases even on mono (since it may strip the IL if it precompiled the method).

Specifically for the "stack trace" scenario, we introduced https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.diagnosticmethodinfo?view=net-9.0 which should work even on NativeAOT - it provides the simple info for a frame (assembly name, type name and member name as strings, not as reflection objects), but it is declared as possibly returning nulls if the runtime simply doesn't have that information.

[bitsandfoxes]

Just for my understanding - and to help prioritizing this, is this just about cleaning up the check? Or would we actually get better stack frames?

[jamescrosswell]

Just for my understanding - and to help prioritizing this, is this just about cleaning up the check? Or would we actually get better stack frames?

If we can get Ben.Demystifier working with AOT, we should get better stack frames yes... that code above could be changed to:

 var frames = (_options.StackTraceMode == StackTraceMode.Enhanced) 
     ? EnhancedStackTrace.GetFrames(stackTrace).Select(p => new RealStackFrame(p)) 
     : stackTrace.GetFrames().Select(p => new RealStackFrame(p)); 

[bitsandfoxes]

If we can get Ben.Demystifier working with AOT

I'm failing to keep track of how to get there. Is #3230 the only missing part?

[jamescrosswell]

I'm failing to keep track of how to get there. Is #3230 the only missing part?

Yes I think so. I added some detail to that issue as well.