[all-commits] [llvm/llvm-project] 162848: ignore -flto= options recognized by GCC

[Sylvestre Ledru via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1628486548420f85b3467026d54663d1516404f5
      https://github.com/llvm/llvm-project/commit/1628486548420f85b3467026d54663d1516404f5
  Author: Sylvestre Ledru <sylvestre at debian.org>
  Date:   2021-04-05 (Mon, 05 Apr 2021)

  Changed paths:
    M clang/include/clang/Driver/Options.td

  Log Message:
  -----------
  ignore -flto= options recognized by GCC

as requested in https://bugs.llvm.org/show_bug.cgi?id=49553, submitting the proposed changes to just ignore the -flto= options which are recognized by GCC ("auto" and "jobserver").

GCC supports -flto=<auto|jobserver|<N> to select the parallelity for LTO builds. LLVM also has -flto-jobs=<N>, which only seems to have a meaning when used with -flto=thin?

The attached patch just ignores the values "auto" and "jobserver". that doesn't change anything in functionality.  Another option would be to map these values to either "thin" or "full", maybe in presence of the -ffat-lto-objects option?

-flto=<n> could also be translated to -flto-jobs=<N>.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D99501