FYI: LLDB DWARF tests on Windows are broken

It looks like tests of DWARF-specific functionality on Windows are failing because we’re actually generating CodeView in a PDB rather than DWARF.

For example, TestSignedTypes.py fails for reasons completely unrelated to whether the types are signed or not. Apparently DWARF and CodeView consider the bounds of the live range for the variables to be slightly different. When using CodeView info, there’s a thread step-over command that takes you just outside the scope block, so the subsequent frame variable command fails to produce the expected output.

The makefile creates compile steps with -g and link steps with -fuse-lld, so you’d expect DWARF, but, due to recent changes in clang and lld, this will actually produce CodeView/PDB when building for Windows.

I’ll look into a fix tomorrow. I’m told it might involve not only tweaking the makefile flags for these tests, but also ensuring that the clang driver passes the right flags to lld.