NativeAOT symbols are broken on linux when publishing Release

[agocke]

I would expect symbols to be worse, but not broken in this configuration.

It looks like change is caused by passing -O to clang when linking the binaries. Without -O, debugging symbols are present and functional. With -O, all symbols and stacks are broken.

It's something in the DWARF info emitted by ILC.

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[MichalStrehovsky]

With -O, all symbols and stacks are broken.

Do you have repro steps? I just debugged a coredump in #77522 (comment) and stacks looked fine.

I can't find where we would be passing -O to clang in our build targets.

[agocke]

Repro is in an Ubuntu 22.04 WSL instance with RC2, publishing helloworld using dotnet publish -r linux-x64 -c Release -bl.

Afterwards I open up the exe in GDB and I get the following:

GNU gdb (Ubuntu 12.0.90-0ubuntu1) 12.0.90
Reading symbols from ./bin/Release/net7.0/linux-x64/publish/aot1...
Dwarf Error: Could not find abbrev number 94 in CU at offset 0x0 [in module /home/andy/tmp/aot1/bin/Release/net7.0/linux-x64/publish/aot1]
(No debugging symbols found in ./bin/Release/net7.0/linux-x64/publish/aot1)

Function names are still around, but line number and file info is lost, as well as the symbol table.

You're right about -O though, I can't see that in the command line. I must have accidentally added that manually when altering the linking command to build against local bits. My clang invocation is

"clang" "obj/Release/net7.0/linux-x64/native/aot1.o" -o "bin/Release/net7.0/linux-x64/native/aot1" /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/sdk/libbootstrapper.a /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/sdk/libRuntime.WorkstationGC.a /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/framework/libSystem.Native.a /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/framework/libSystem.Globalization.Native.a /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/framework/libSystem.IO.Compression.Native.a /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/framework/libSystem.Net.Security.Native.a /home/andy/.nuget/packages/runtime.linux-x64.microsoft.dotnet.ilcompiler/7.0.0-rc.2.22472.3/framework/libSystem.Security.Cryptography.Native.OpenSsl.a -g -Wl,-rpath,'$ORIGIN' -Wl,--build-id=sha1 -Wl,--as-needed -pthread -lstdc++ -ldl -lm -lz -lrt -pie -Wl,-z,relro -Wl,-z,now -Wl,--discard-all -Wl,--gc-sections

[agocke]

AH, my mistake, it's not the linking command that makes a difference, it's passing -O to ILC. Without it, debugging info is fine.