qt5base-lts/cmake/FindWrapRt.cmake
Amir Masoud Abdol 75ca710370 Improve FindWrapRt, and SHM detection
Apparently, more and more librt functionality are being moved to glibc
these days, e.g., clock_gettime, clock_getres, clock_settime,
clock_getcpuclockid, clock_nanosleep. As Thiago mentioned, in face,
all librt functions are moving into glibc, but unlike the clock_*
functions that I can see are ported from 2.17+, I cannot find out when
and what functions are already ported. So, here, I added a second test
which tries to explicitly look for shm_* functions, if they are there,
as well as the clock_* function, then we are more confident that we
actually have a useful the libRt in the system.

Also, making the FEATURE_posix_SHM depends on UNIX.

Pick-to: 6.5
Fixes: QTBUG-111049
Change-Id: I08b7f4656ecd9313b552fb05ca7096f5b987b95a
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2023-02-10 22:44:11 +01:00

58 lines
1.3 KiB
CMake

# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: BSD-3-Clause
# We can't create the same interface imported target multiple times, CMake will complain if we do
# that. This can happen if the find_package call is done in multiple different subdirectories.
if(TARGET WrapRt::WrapRt)
set(WrapRt_FOUND ON)
return()
endif()
set(WrapRt_FOUND OFF)
include(CheckCXXSourceCompiles)
include(CMakePushCheckState)
find_library(LIBRT rt)
cmake_push_check_state()
if(LIBRT)
list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBRT}")
endif()
check_cxx_source_compiles("
#include <time.h>
#include <unistd.h>
int main(int, char **) {
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
return 0;
}
" HAVE_GETTIME)
check_cxx_source_compiles("
#include <sys/types.h>
#include <sys/mman.h>
#include <fcntl.h>
int main(int, char **) {
shm_open(\"test\", O_RDWR | O_CREAT | O_EXCL, 0666);
shm_unlink(\"test\");
return 0;
}
" HAVE_SHM_OPEN_SHM_UNLINK)
cmake_pop_check_state()
if(HAVE_GETTIME OR HAVE_SHM_OPEN_SHM_UNLINK)
set(WrapRt_FOUND ON)
add_library(WrapRt::WrapRt INTERFACE IMPORTED)
if (LIBRT)
target_link_libraries(WrapRt::WrapRt INTERFACE "${LIBRT}")
endif()
endif()
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(WrapRt DEFAULT_MSG WrapRt_FOUND)