[all-commits] [llvm/llvm-project] 0cfb00: [lld] Add lto-pgo-warn-mismatch option

[Yolanda-Chen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0cfb00a1c98f8ca3749b8d829b7301f397efa302
      https://github.com/llvm/llvm-project/commit/0cfb00a1c98f8ca3749b8d829b7301f397efa302
  Author: Yolanda Chen <yolanda.chen at intel.com>
  Date:   2021-08-11 (Wed, 11 Aug 2021)

  Changed paths:
    M lld/COFF/Config.h
    M lld/COFF/Driver.cpp
    M lld/COFF/LTO.cpp
    M lld/COFF/Options.td
    M lld/ELF/Config.h
    M lld/ELF/Driver.cpp
    M lld/ELF/LTO.cpp
    M lld/ELF/Options.td
    A lld/test/COFF/Inputs/thinlto_cs.proftext
    A lld/test/COFF/thinlto-pgo-warn.ll
    A lld/test/ELF/lto/Inputs/thinlto_cs.proftext
    A lld/test/ELF/lto/thinlto-pgo-warn.ll
    M llvm/include/llvm/LTO/Config.h
    M llvm/lib/LTO/LTOBackend.cpp
    M llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp

  Log Message:
  -----------
  [lld] Add lto-pgo-warn-mismatch option

When enable CSPGO for ThinLTO, there are profile cfg mismatch warnings that will cause lld-link errors (with /WX).
To disable it we have to use an internal "/mllvm:-no-pgo-warn-mismatch" option.
In contrast clang uses option ”-Wno-backend-plugin“ to avoid such warnings and gcc has an explicit "-Wno-coverage-mismatch" option.

Add this "lto-pgo-warn-mismatch" option to lld to help turn on/off the profile mismatch warnings explicitly when build with ThinLTO and CSPGO.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D104431