PHP tests fails with GCC 14.0.1

[jplesnik]

PHP tests are failing with new GCC 14.0.1 in Fedora Rawhide.

/usr/include/php/Zend/zend_atomic.h: In function ‘zend_atomic_bool_exchange_ex’:
/usr/include/php/Zend/zend_atomic.h:88:16: error: implicit declaration of function ‘__c11_atomic_exchange’; did you mean ‘__atomic_exchange’? [-Wimplicit-function-declaration]
   88 |         return __c11_atomic_exchange(&obj->value, desired, __ATOMIC_SEQ_CST);
      |                ^~~~~~~~~~~~~~~~~~~~~
      |                __atomic_exchange
/usr/include/php/Zend/zend_atomic.h: In function ‘zend_atomic_bool_load_ex’:
/usr/include/php/Zend/zend_atomic.h:92:16: error: implicit declaration of function ‘__c11_atomic_load’; did you mean ‘__atomic_load’? [-Wimplicit-function-declaration]
   92 |         return __c11_atomic_load(&obj->value, __ATOMIC_SEQ_CST);
      |                ^~~~~~~~~~~~~~~~~
      |                __atomic_load
/usr/include/php/Zend/zend_atomic.h: In function ‘zend_atomic_bool_store_ex’:
/usr/include/php/Zend/zend_atomic.h:96:9: error: implicit declaration of function ‘__c11_atomic_store’; did you mean ‘__atomic_store’? [-Wimplicit-function-declaration]
   96 |         __c11_atomic_store(&obj->value, desired, __ATOMIC_SEQ_CST);
      |         ^~~~~~~~~~~~~~~~~~
      |         __atomic_store

The tests fail for SWIG 4.1.0, more detail about dependency changes are on
https://koschei.fedoraproject.org/build/17075088

The tests fail also for the latest commit 521d43d
https://copr.fedorainfracloud.org/coprs/jplesnik/swig-rebuild/build/6917038/

[ojwb]

The error is in code in the PHP API headers, so this doesn't look like SWIG's fault to me.

[ojwb]

The missing functions seem to be clang-specific: https://releases.llvm.org/15.0.0/tools/clang/docs/LanguageExtensions.html#c11-atomic-builtins

PHP's zend_atomic.h tests #if __has_feature(c_atomic) but assumes that's only true for clang, but it's now true for GCC as well but GCC doesn't provide these functions with the non-standard names.

A simple fix would probably be to change that conditional in PHP to:

#if __has_feature(c_atomic) && defined __clang__

Not a SWIG bug so closing.