[all-commits] [llvm/llvm-project] e09f77: [ELF] Remove support for legacy .zdebug sections

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e09f77d39426dfd1a2cb05ac9de070220a3ef26f
      https://github.com/llvm/llvm-project/commit/e09f77d39426dfd1a2cb05ac9de070220a3ef26f
  Author: Fangrui Song <i at maskray.me>
  Date:   2022-06-02 (Thu, 02 Jun 2022)

  Changed paths:
    M lld/ELF/InputSection.cpp
    M lld/ELF/InputSection.h
    M lld/docs/ReleaseNotes.rst
    M lld/test/ELF/compressed-debug-input.s
    R lld/test/ELF/relocatable-compressed-input.s
    M lld/test/ELF/strip-debug.s

  Log Message:
  -----------
  [ELF] Remove support for legacy .zdebug sections

.zdebug is unlikely used any longer: gcc -gz switched from legacy
.zdebug to SHF_COMPRESSED with binutils 2.26 (2016), which has been
several years. clang 14 dropped -gz=zlib-gnu support. According to
Debian Code Search (`gz=zlib-gnu`), no project uses -gz=zlib-gnu.

Remove .zdebug support to (a) simplify code and (b) allow removal of llvm-mc's
--compress-debug-sections=zlib-gnu.

In case the old object file `a.o` uses .zdebug, run `objcopy --decompress-debug-sections a.o`

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D126793