ell/signal.h: use sigset_t instead of internal libc implementation

Fixes compilation on musl libc which doesn't show up the internal implementation.

Error message:

CC ell/main.lo
In file included from ell/main.c:35:
ell/signal.h:39:40: error: unknown type name '__sigset_t'
struct l_signal *l_signal_create(const __sigset_t *mask,

                                        ^~~~~~~~~~
---
 ell/signal.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 0d4fdc8..98cf0fa 100644
@@ -36,7 +36,7 @@ typedef void (*l_signal_notify_cb_t) (struct l_signal *signal,
 					uint32_t signo, void *user_data);
 typedef void (*l_signal_destroy_cb_t) (void *user_data);
 
-struct l_signal *l_signal_create(const __sigset_t *mask,
+struct l_signal *l_signal_create(const sigset_t *mask,
 			l_signal_notify_cb_t callback,
 			void *user_data, l_signal_destroy_cb_t destroy);
 void l_signal_remove(struct l_signal *signal);

2.19.1

Hi Maxwell,

Please use full name in author information.

I tried to make this work with -std=c99 and I am kinda lost on what the right approach here is. Define _USE_POSIX or what is the recommendation?

Regards

Marcel

Hi Marcel,

Sorry about the duplicate e-mail. I neglected to reply to all earlier.

Ideally ELL's public API should not depend on the definition of a feature test macro, but if one is going to be defined I'd avoid __USE_POSIX since it's a glibc implementation detail. I'd go with _DEFAULT_SOURCE, which I think is specific to glibc, or one of the standard _POSIX_SOURCE, _POSIX_C_SOURCE (>= 1), or _XOPEN_SOURCE. Relevant feature test macro documentation:

http://man7.org/linux/man-pages/man7/feature_test_macros.7.html
http://pubs.opengroup.org/onlinepubs/007904975/functions/xsh_chap02_02.html
https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html

BTW, this problem isn't specific to -std=c99 builds. It occurs with -std=c11 and -ansi, too.

HTH,
-Ossama