Files
CMake/Modules/Internal/CheckLinkerFlag.cmake
Brad King c2341ece47 CheckLinkerFlag: Catch linker warning when the checked flag is ignored
Prior to commit 219dde4ea8 (CheckPIESupported: now uses any SYSROOT settings,
2022-01-16, v3.23.0-rc1~110^2), the checks for `-pie` and `-no_pie` on macOS
failed due to executing the compiler directly without any `-isysroot`,
producing `ld: library not found for -lc++`.  See issues #23053 and #19180.
The failing check for `-pie` was a bug because it is supported on macOS,
both for `x86_64` and `arm64`, and the commit fixed that check.

However, `-no_pie` is not supported on macOS `arm64`.  The above commit was
only able to detect that due to commit f745e0497e (CheckCompilerFlags: Catch
linker warning about ignored flags, 2022-01-03, v3.23.0-rc1~174^2), which we
need to revert due to issue #23432.  Instead, catch only the linker warning
about the exact flag being checked.
2022-04-21 11:35:30 -04:00

53 lines
1.6 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
include_guard(GLOBAL)
include(Internal/CheckFlagCommonConfig)
include(Internal/CheckSourceCompiles)
include(CMakeCheckCompilerFlagCommonPatterns)
cmake_policy(PUSH)
cmake_policy(SET CMP0054 NEW) # if() quoted variables not dereferenced
function(CMAKE_CHECK_LINKER_FLAG _lang _flag _var)
# link step supports less languages than the compiler
# so do a first check about the requested language
if (_lang STREQUAL "ISPC")
message (SEND_ERROR "check_linker_flag: ${_lang}: unsupported language.")
return()
endif()
# Parse extra arguments
cmake_parse_arguments(PARSE_ARGV 3 CHECK_LINKER_FLAG "" "OUTPUT_VARIABLE" "")
cmake_check_flag_common_init("check_linker_flag" ${_lang} _lang_src _lang_fail_regex)
set(CMAKE_REQUIRED_LINK_OPTIONS "${_flag}")
check_compiler_flag_common_patterns(_common_patterns)
# Match linker warnings if the exact flag is ignored.
foreach(flag IN LISTS _flag)
string(REGEX REPLACE "([][+.*?()^$])" [[\\\1]] _flag_regex "${flag}")
list(APPEND _common_patterns
FAIL_REGEX "warning: .*${_flag_regex}.* ignored"
)
endforeach()
cmake_check_source_compiles(${_lang}
"${_lang_src}"
${_var}
${_lang_fail_regex}
${_common_patterns}
OUTPUT_VARIABLE _output
)
if (CHECK_LINKER_FLAG_OUTPUT_VARIABLE)
set(${CHECK_LINKER_FLAG_OUTPUT_VARIABLE} "${_output}" PARENT_SCOPE)
endif()
cmake_check_flag_common_finish()
endfunction()
cmake_policy(POP)