ARM32 Debug Info

[Const-me]

Unless ILC debug output is disabled in .csproj, CoreRT’s ilc program fails to compile stuff.

This assert fails.

I’ve added a bit more info and found out it’s VLT_FPSTK.

Using Debian 9.5, tried dotnet-sdk-2.1.802 and dotnet-sdk-2.2.402, same result.

Steps to reproduce:

dotnet new console

Patch project file as described there and also add <DisableUnsupportedError>true</DisableUnsupportedError>

Run dotnet publish --configuration Release --runtime linux-arm

Native stack at the time of failed assert. Stops at first managed frame ‘coz gdb can’t debug .NET, at least not by default.

#6  0xa352510c in EmitVarLocation(llvm::MCObjectStreamer*, ICorDebugInfo::NativeVarInfo const&, bool)
#7  0xa3525ab2 in VarInfo::DumpLocsIfNeeded(llvm::MCObjectStreamer*, llvm::MCSection*, llvm::MCExpr const*)
#8  0xa35260be in SubprogramInfo::DumpDebugLoc(llvm::MCObjectStreamer*, llvm::MCSection*)
#9  0xa3525e3c in SubprogramInfo::Dump(UserDefinedDwarfTypesBuilder*, llvm::MCObjectStreamer*, llvm::MCSection*, llvm::MCSection*, llvm::MCSection*)
#10 0xa3526b36 in DwarfGen::Finish()
#11 0xa3501804 in ObjectWriter::EmitDebugModuleInfo()
#12 0xa34fd5f0 in EmitDebugModuleInfo
gdb can’t debug .net so the stack trace stops there.
#13 0xa7bbe1ac in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Strangely enough, comments in ObjectWriter.EmitObject method, there https://github.com/dotnet/corert/blob/8153381fb8f3cf0ef627011fe2fe87fb4a857540/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ObjectWriter.cs#L1044 and a few other things https://github.com/dotnet/corert/blob/8153381fb8f3cf0ef627011fe2fe87fb4a857540/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ObjectWriter.cs#L1094-L1095 suggest that code was running on ARM32 at some point.

Is something wrong on my side? If it’s just not supported, how easy it is to support?