Need for libatomic is correctly determined, but CMake cannot “find” it then, which breaks configure

[barracuda156]

libatomic test works now, but configuring breaks down:

:info:configure CMake Error at CMakeLists.txt:310 (message):
:info:configure   32-bit target detected (sizeof(void*) == 4).  aMule's download bandwidth
:info:configure   throttler holds the byte budget as std::atomic<int64_t>; 32-bit CPUs lack a
:info:configure   native 8-byte atomic and the operations expand to library calls
:info:configure   (__atomic_*_8) that live in libatomic.  libatomic was not found on this
:info:configure   system.  Install it and re-run cmake:
:info:configure     Debian/Ubuntu/Mint: libatomic1-dev
:info:configure     Fedora/RHEL/Rocky/Arch: libatomic
:info:configure     macOS/MacPorts: bundled with gcc; install gcc14+
:info:configure -- Configuring incomplete, errors occurred!

libatomic is an internal library of GCC, CMake should not “look for it”.

Earlier issue: amule-project#643

[barracuda156]

Ah, it does not actually test now but just requires it for 32 bit, and CMake does not see it then via find_library call.

[barracuda156]

Perhaps CMake cannot find libatomic simple because there is neither cmake config file for it nor .pc?

[got3nks]

Confirmed — the check used find_library(atomic), which only searches standard filesystem paths, so it misses GCC's internal libatomic (it lives under the compiler's own runtime dir). #454 swaps it for check_library_exists, which links a -latomic probe through the compiler driver, so it resolves GCC's copy — or a system libatomic — wherever -latomic actually links.

Could you test the branch on your toolchain? It should now configure past the libatomic check:

git clone -b fix/libatomic-gcc-detection https://github.com/got3nks/amule.git
cd amule
cmake -B build   # + your usual MacPorts flags / toolchain

Or fetch it into an existing checkout:

git fetch https://github.com/got3nks/amule.git fix/libatomic-gcc-detection
git checkout FETCH_HEAD

If configure gets past the libatomic step (and the build links), I'll tick the last box on #454. Thanks for the report.

[got3nks]

Hello @barracuda156, have you had a chance to test the fix?