[RFC][BZ #16549] Add sanity check for condvar alignment.

[Ondřej Bílka]

On Tue, Feb 11, 2014 at 09:21:11AM -0800, Roland McGrath wrote:
> > +  assert (((uintptr_t) cond) % sizeof (long) == 0);
> 
> Drop superfluous parens.  Use __alignof (pthread_cond_t).

OK now?

	* nptl/pthread_cond_init.c (__pthread_cond_init): Add assert that
	input is aligned.

diff --git a/nptl/pthread_cond_init.c b/nptl/pthread_cond_init.c
index 27efc9c..6fa522a 100644
--- a/nptl/pthread_cond_init.c
+++ b/nptl/pthread_cond_init.c
@@ -16,6 +16,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <assert.h>
 #include <shlib-compat.h>
 #include "pthreadP.h"
 #include <stap-probe.h>
@@ -28,6 +29,7 @@ __pthread_cond_init (cond, cond_attr)
 {
   struct pthread_condattr *icond_attr = (struct pthread_condattr *) cond_attr;

+  assert ((uintptr_t) cond % __alignof (pthread_cond_t) == 0);
   cond->__data.__lock = LLL_LOCK_INITIALIZER;
   cond->__data.__futex = 0;
   cond->__data.__nwaiters = (icond_attr != NULL