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Differential D118546

[llvm][cmake] Shore up `llvm_check_linker_flags`.
ClosedPublic

Authored by Ericson2314 on Jan 29 2022, 4:08 PM.

Details

Reviewers
phosek
beanz
compnerd
sebastian-ne
Commits
rG3ebb2c0427aa: [llvm][cmake] Shore up `llvm_check_linker_flags`.
Summary

Ensure CMAKE_EXE_LINKER_FLAGS effects the underlying try_compile by setting
this policy to use the new, non-deprecated behavior, without effecting the
caller.

Normally this shouldn't be necessary, as CMake uses
cmake_minimum_required(VERSION 3.13.4) consistently, but I suppose
this could rear its head in a downstream project?

Diff Detail

Event Timeline

Ericson2314 created this revision.Jan 29 2022, 4:08 PM
Herald added a subscriber: mgorny. · View Herald TranscriptJan 29 2022, 4:08 PM
Ericson2314 requested review of this revision.Jan 29 2022, 4:08 PM
Herald added a project: Restricted Project. · View Herald TranscriptJan 29 2022, 4:08 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
Harbormaster completed remote builds in B146487: Diff 404312.Jan 29 2022, 4:50 PM
sebastian-ne accepted this revision.Jul 25 2022, 4:48 AM
sebastian-ne added a subscriber: sebastian-ne.

Looks reasonable to me. The function is pretty useless without this policy.

This revision is now accepted and ready to land.Jul 25 2022, 4:48 AM
Herald added a project: Restricted Project. · View Herald TranscriptJul 25 2022, 4:48 AM
This revision was landed with ongoing or failed builds.Jul 25 2022, 9:02 AM
Closed by commit rG3ebb2c0427aa: [llvm][cmake] Shore up `llvm_check_linker_flags`. (authored by Ericson2314). · Explain Why
This revision was automatically updated to reflect the committed changes.
Ericson2314 added a commit: rG3ebb2c0427aa: [llvm][cmake] Shore up `llvm_check_linker_flags`..
Ericson2314 added a comment.Jul 25 2022, 9:03 AM

Thanks!

I am not sure we ever got to the bottom of why deduping this code between projects wasn't working (in other open revisions), but this would certainly help / rule out a few extreme scenarios.

Ericson2314 mentioned this in D130541: [cmake] Dedup linker flag check polyfill.Jul 25 2022, 8:34 PM

Revision Contents

PathSize
llvm/
cmake/
modules/
3 lines

Diff 447365

llvm/cmake/modules/LLVMCheckLinkerFlag.cmake

include(CheckLinkerFlag OPTIONAL) include(CheckLinkerFlag OPTIONAL)
if (COMMAND check_linker_flag) if (COMMAND check_linker_flag)
macro(llvm_check_linker_flag) macro(llvm_check_linker_flag)
check_linker_flag(${ARGN}) check_linker_flag(${ARGN})
endmacro() endmacro()
else() else()
# Until the minimum CMAKE version is 3.18 # Until the minimum CMAKE version is 3.18
include(CheckCXXCompilerFlag) include(CheckCXXCompilerFlag)
include(CMakePushCheckState) include(CMakePushCheckState)
# cmake builtin compatible, except we assume lang is C or CXX # cmake builtin compatible, except we assume lang is C or CXX
function(llvm_check_linker_flag lang flag out_var) function(llvm_check_linker_flag lang flag out_var)
cmake_policy(PUSH)
cmake_policy(SET CMP0056 NEW)
cmake_push_check_state() cmake_push_check_state()
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${flag}") set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${flag}")
if("${lang}" STREQUAL "C") if("${lang}" STREQUAL "C")
check_c_compiler_flag("" ${out_var}) check_c_compiler_flag("" ${out_var})
elseif("${lang}" STREQUAL "CXX") elseif("${lang}" STREQUAL "CXX")
check_cxx_compiler_flag("" ${out_var}) check_cxx_compiler_flag("" ${out_var})
else() else()
message(FATAL_ERROR "\"${lang}\" is not C or CXX") message(FATAL_ERROR "\"${lang}\" is not C or CXX")
endif() endif()
cmake_pop_check_state() cmake_pop_check_state()
cmake_policy(POP)
endfunction() endfunction()
endif() endif()