[all-commits] [llvm/llvm-project] 59c9a4: [llvm-gsymutil] Fix assert failure on FileEntry.Di...

[kusmour via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 59c9a48d5e19716e5df8d0f794e489891fd2c835
      https://github.com/llvm/llvm-project/commit/59c9a48d5e19716e5df8d0f794e489891fd2c835
  Author: kusmour <kusmour at gmail.com>
  Date:   2024-01-29 (Mon, 29 Jan 2024)

  Changed paths:
    M llvm/lib/DebugInfo/GSYM/GsymCreator.cpp
    A llvm/test/tools/llvm-gsymutil/X86/elf-empty-dir.yaml

  Log Message:
  -----------
  [llvm-gsymutil] Fix assert failure on FileEntry.Dir empty (#79926)

Summary:
FileEntry.Dir can be empty if debug info only contains relative path.
This caused an assertion failure when gsym segmentation is trying to
copy a file entry with empty dir. As the fitst entry of StringTable is
always empty (and is preserved), `StringOffsetMap` doesn't have key 0.
Hence, `find(0)` returns `End` and `operator->()` fails the assertion

Test Plan:
./bin/llvm-lit -sv llvm/test/tools/llvm-gsymutil/X86/elf-empty-dir.yaml