[all-commits] [llvm/llvm-project] a66311: DWARFv5: Disable DW_OP_convert for configurations ...

[David Blaikie via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a66311277af3c254cb73a749e8c4478d50a37bb0
      https://github.com/llvm/llvm-project/commit/a66311277af3c254cb73a749e8c4478d50a37bb0
  Author: David Blaikie <dblaikie at gmail.com>
  Date:   2020-10-22 (Thu, 22 Oct 2020)

  Changed paths:
    M llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
    M llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
    M llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
    M llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
    M llvm/test/DebugInfo/X86/convert-debugloc.ll
    M llvm/test/DebugInfo/X86/convert-loclist.ll

  Log Message:
  -----------
  DWARFv5: Disable DW_OP_convert for configurations that don't yet support it

Testing reveals that lldb and gdb have some problems with supporting
DW_OP_convert - gdb with Split DWARF tries to resolve the CU-relative
DIE offset relative to the skeleton DIE. lldb tries to treat the offset
as absolute, which judging by the llvm-dsymutil support for
DW_OP_convert, I guess works OK in MachO? (though probably llvm-dsymutil
is producing invalid DWARF by resolving the relative reference to an
absolute one?).

Specifically this disables DW_OP_convert usage in DWARFv5 if:
* Tuning for GDB and using Split DWARF
* Tuning for LLDB and not targeting MachO