[all-commits] [llvm/llvm-project] f62e60: [MCDwarf] Respect -fdebug-prefix-map= for generate...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f62e60fb238146113f84e0efb1a2ebc52f05cc0a
      https://github.com/llvm/llvm-project/commit/f62e60fb238146113f84e0efb1a2ebc52f05cc0a
  Author: Fangrui Song <i at maskray.me>
  Date:   2022-08-12 (Fri, 12 Aug 2022)

  Changed paths:
    M llvm/include/llvm/MC/MCContext.h
    M llvm/include/llvm/MC/MCDwarf.h
    M llvm/lib/MC/MCContext.cpp
    M llvm/lib/MC/MCDwarf.cpp
    M llvm/test/MC/ELF/debug-prefix-map.s

  Log Message:
  -----------
  [MCDwarf] Respect -fdebug-prefix-map= for generated assembly debug info (DWARF v5)

For generated assembly debug info, MCDwarfLineTableHeader::CompilationDir is an
unmapped path set in MCContext::setGenDwarfRootFile. Remap it.

A relative destination path of -fdebug-prefix-map= exposes a llvm-dwarfdump bug
which joins relative DW_AT_comp_dir and directories[0].

Fix https://github.com/llvm/llvm-project/issues/56609

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D131749