Detection of libatomic is broken since version 2.47.0 and
b7f0d87daf
because C language is not enabled anymore:
-- Looking for __atomic_fetch_add_4 in atomic
-- Looking for __atomic_fetch_add_4 in atomic - not found
CMake Error at cmake_modules/CheckAtomic.cmake:59 (message):
Host compiler appears to require libatomic, but cannot find it.
Call Stack (most recent call first):
CMakeLists.txt:54 (include)
Indeed if C language is not enabled, the test will be run with the C++
compiler resulting in the following error:
Building CXX object CMakeFiles/cmTC_03d01.dir/CheckFunctionExists.cxx.o
/home/fabrice/buildroot/output/host/bin/x86_64-linux-g++ --sysroot=/home/fabrice/buildroot/output/host/x86_64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -O1 -g0 -D_FORTIFY_SOURCE=2 -DCHECK_FUNCTION_EXISTS=__atomic_fetch_add_4 -DNDEBUG -o CMakeFiles/cmTC_03d01.dir/CheckFunctionExists.cxx.o -c /home/fabrice/buildroot/output/build/i2pd-2.49.0/build/CMakeFiles/CMakeScratch/TryCompile-NApnv9/CheckFunctionExists.cxx
<command-line>: error: new declaration ‘char __atomic_fetch_add_4()’ ambiguates built-in declaration ‘unsigned int __atomic_fetch_add_4(volatile void*, unsigned int, int)’ [-fpermissive]
whereas with a C compiler, we'll get:
Building C object CMakeFiles/cmTC_7e47b.dir/CheckFunctionExists.c.o
/home/fabrice/buildroot/output/host/bin/x86_64-linux-gcc --sysroot=/home/fabrice/buildroot/output/host/x86_64-buildroot-linux-gnu/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -O1 -g0 -D_FORTIFY_SOURCE=2 -DCHECK_FUNCTION_EXISTS=__atomic_fetch_add_4 -DNDEBUG -o CMakeFiles/cmTC_7e47b.dir/CheckFunctionExists.c.o -c /home/fabrice/buildroot/output/build/i2pd-2.49.0/build/CMakeFiles/CMakeScratch/TryCompile-e0zFMG/CheckFunctionExists.c
<command-line>: warning: conflicting types for built-in function ‘__atomic_fetch_add_4’; expected ‘unsigned int(volatile void *, unsigned int, int)’ [-Wbuiltin-declaration-mismatch]
Fix#1908
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
