[GCC15] error: passing argument 2 of a_Timeout_add from incompatible pointer type [-Wincompatible-pointer-types]

[Kangie]

x86_64-pc-linux-gnu-gcc -DHAVE_CONFIG_H -I. -I..  -I.. -DDILLO_SYSCONF='"/etc/dillo/"' -DDILLO_DOCDIR='"/usr/share/doc/dillo-3.1.1/"' -DCUR_WORKING_DIR='"/var/tmp/portage/www-client/dillo-3.1.1/work/dillo-3.1.1/src"'   -I/usr/include/libpng16 -O2 -pipe -march=native -fno-diagnostics-color -DENABLE_I
cache.c: In function Cache_delayed_process_queue:
cache.c:1388:26: error: passing argument 2 of a_Timeout_add from incompatible pointer type [-Wincompatible-pointer-types]
 1388 |       a_Timeout_add(0.0, Cache_delayed_process_queue_callback, NULL);
      |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

See: https://bugs.gentoo.org/944457

[rodarima]

Not sure what the problem is here:

/* timeout.hh */
typedef void (*TimeoutCb_t)(void *data);
void a_Timeout_add(float t, TimeoutCb_t cb, void *cbdata);

/* cache.c */
static void Cache_delayed_process_queue_callback(void *ptr)
{
  /* ... */
}

static void Cache_delayed_process_queue(CacheEntry_t *entry)
{
   /* ... */
   a_Timeout_add(0.0, Cache_delayed_process_queue_callback, NULL);
   /* ... */
}

It is compiling ok on gcc trunk: https://godbolt.org/z/adPcq8G5d

(GCC 15 is not released yet)

Edit: Looking at the logs, it looks like a gcc bug:

cache.c: In function ‘Cache_delayed_process_queue’:
cache.c:1388:26: error: passing argument 2 of ‘a_Timeout_add’ from incompatible pointer type [-Wincompatible-pointer-types]
 1388 |       a_Timeout_add(0.0, Cache_delayed_process_queue_callback, NULL);
      |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                          |
      |                          void (*)(void)
In file included from cache.c:37:
timeout.hh:10:41: note: expected ‘TimeoutCb_t’ {aka ‘void (*)(void *)’} but argument is of type ‘void (*)(void)’
   10 | void a_Timeout_add(float t, TimeoutCb_t cb, void *cbdata);
      |                             ~~~~~~~~~~~~^~
make[3]: *** [Makefile:691: cache.o] Error 1

The argument Cache_delayed_process_queue_callback seems to me to have type void (*)(void *).