Make use of gcc attributes in some standard include headers.

The `nonnull' attribute specifies that some function parameters should be
non-null pointers.  This is very useful as it helps the compiler generate
warnings on suspicious code and can also enable some small optimizations.

Also start using 'alloc_size' attribute in the allocator functions.

This is an initial step to better integrate our libc with the compiler:
these attributes are fully supported by clang and they are also useful
for the static analyzer.

Note that due to some bogus internal procedure in the way gcc ports
are built they may require updating if they were built before r280801.

Relnotes:		yes
Hinted by:		Android's bionic libc
Differential Revision:	https://reviews.freebsd.org/D2107

3 files changed, 94 insertions, 73 deletions

diff --git a/include/pthread.h b/include/pthread.h
index ee66c65..8b59223 100644
--- a/include/pthread.h
+++ b/include/pthread.h
@@ -144,19 +144,25 @@ struct _pthread_cleanup_info {
  */
 __BEGIN_DECLS
 int		pthread_atfork(void (*)(void), void (*)(void), void (*)(void));
-int		pthread_attr_destroy(pthread_attr_t *);
+int		pthread_attr_destroy(pthread_attr_t *) __nonnull(1);
 int		pthread_attr_getstack(const pthread_attr_t * __restrict, 
-			void ** __restrict, size_t * __restrict);
-int		pthread_attr_getstacksize(const pthread_attr_t *, size_t *);
+			void ** __restrict, size_t * __restrict)
+			__nonnull_all;
+int		pthread_attr_getstacksize(const pthread_attr_t *, size_t *)
+			__nonnull_all;
 int		pthread_attr_getguardsize(const pthread_attr_t *, size_t *);
 int		pthread_attr_getstackaddr(const pthread_attr_t *, void **);
-int		pthread_attr_getdetachstate(const pthread_attr_t *, int *);
-int		pthread_attr_init(pthread_attr_t *);
-int		pthread_attr_setstacksize(pthread_attr_t *, size_t);
-int		pthread_attr_setguardsize(pthread_attr_t *, size_t);
-int		pthread_attr_setstack(pthread_attr_t *, void *, size_t);
+int		pthread_attr_getdetachstate(const pthread_attr_t *, int *)
+			__nonnull_all;
+int		pthread_attr_init(pthread_attr_t *) __nonnull(1);
+int		pthread_attr_setstacksize(pthread_attr_t *, size_t)
+			__nonnull(1);
+int		pthread_attr_setguardsize(pthread_attr_t *, size_t)
+			__nonnull(1);
+int		pthread_attr_setstack(pthread_attr_t *, void *, size_t)
+			__nonnull(1);
 int		pthread_attr_setstackaddr(pthread_attr_t *, void *);
-int		pthread_attr_setdetachstate(pthread_attr_t *, int);
+int		pthread_attr_setdetachstate(pthread_attr_t *, int) __nonnull(1);
 int		pthread_barrier_destroy(pthread_barrier_t *);
 int		pthread_barrier_init(pthread_barrier_t *,
 			const pthread_barrierattr_t *, unsigned);
@@ -164,7 +170,7 @@ int		pthread_barrier_wait(pthread_barrier_t *);
 int		pthread_barrierattr_destroy(pthread_barrierattr_t *);
 int		pthread_barrierattr_getpshared(const pthread_barrierattr_t *,
 			int *);
-int		pthread_barrierattr_init(pthread_barrierattr_t *);
+int		pthread_barrierattr_init(pthread_barrierattr_t *) __nonnull(1);
 int		pthread_barrierattr_setpshared(pthread_barrierattr_t *, int);
 
 #define		pthread_cleanup_push(cleanup_routine, cleanup_arg)		\
@@ -180,98 +186,109 @@ int		pthread_barrierattr_setpshared(pthread_barrierattr_t *, int);
 			__pthread_cleanup_pop_imp(execute);			\
 		}
 
-int		pthread_condattr_destroy(pthread_condattr_t *);
+int		pthread_condattr_destroy(pthread_condattr_t *) __nonnull(1);
 int		pthread_condattr_getclock(const pthread_condattr_t *,
-			clockid_t *);
-int		pthread_condattr_getpshared(const pthread_condattr_t *, int *);
-int		pthread_condattr_init(pthread_condattr_t *);
-int		pthread_condattr_setclock(pthread_condattr_t *, clockid_t);
-int		pthread_condattr_setpshared(pthread_condattr_t *, int);
-int		pthread_cond_broadcast(pthread_cond_t *);
-int		pthread_cond_destroy(pthread_cond_t *);
+			clockid_t *) __nonnull_all;
+int		pthread_condattr_getpshared(const pthread_condattr_t *, int *)
+			__nonnull_all;
+int		pthread_condattr_init(pthread_condattr_t *) __nonnull(1);
+int		pthread_condattr_setclock(pthread_condattr_t *, clockid_t)
+			__nonnull(1);
+int		pthread_condattr_setpshared(pthread_condattr_t *, int)
+			__nonnull(1);
+int		pthread_cond_broadcast(pthread_cond_t *)
+			__nonnull(1);
+int		pthread_cond_destroy(pthread_cond_t *)
+			__nonnull(1);
 int		pthread_cond_init(pthread_cond_t *,
-			const pthread_condattr_t *);
-int		pthread_cond_signal(pthread_cond_t *);
+			const pthread_condattr_t *) __nonnull(1);
+int		pthread_cond_signal(pthread_cond_t *) __nonnull(1);
 int		pthread_cond_timedwait(pthread_cond_t *,
 			pthread_mutex_t *__mutex, const struct timespec *)
-		    __requires_exclusive(*__mutex);
+			__nonnull_all __requires_exclusive(*__mutex);
 int		pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *__mutex)
-		    __requires_exclusive(*__mutex);
+			__nonnull_all __requires_exclusive(*__mutex);
 int		pthread_create(pthread_t *, const pthread_attr_t *,
-			void *(*) (void *), void *);
+			void *(*) (void *), void *) __nonnull(1) __nonnull(3);
 int		pthread_detach(pthread_t);
 int		pthread_equal(pthread_t, pthread_t);
 void		pthread_exit(void *) __dead2;
 void		*pthread_getspecific(pthread_key_t);
-int		pthread_getcpuclockid(pthread_t, clockid_t *);
+int		pthread_getcpuclockid(pthread_t, clockid_t *) __nonnull(2);
 int		pthread_join(pthread_t, void **);
 int		pthread_key_create(pthread_key_t *,
-			void (*) (void *));
+			void (*) (void *)) __nonnull(1);
 int		pthread_key_delete(pthread_key_t);
-int		pthread_mutexattr_init(pthread_mutexattr_t *);
-int		pthread_mutexattr_destroy(pthread_mutexattr_t *);
+int		pthread_mutexattr_init(pthread_mutexattr_t *) __nonnull(1);
+int		pthread_mutexattr_destroy(pthread_mutexattr_t *) __nonnull(1);
 int		pthread_mutexattr_getpshared(const pthread_mutexattr_t *,
-			int *);
-int		pthread_mutexattr_gettype(pthread_mutexattr_t *, int *);
-int		pthread_mutexattr_settype(pthread_mutexattr_t *, int);
-int		pthread_mutexattr_setpshared(pthread_mutexattr_t *, int);
+			int *) __nonnull_all;
+int		pthread_mutexattr_gettype(pthread_mutexattr_t *, int *)
+			__nonnull_all;
+int		pthread_mutexattr_settype(pthread_mutexattr_t *, int)
+			__nonnull(1);
+int		pthread_mutexattr_setpshared(pthread_mutexattr_t *, int)
+			__nonnull(1);
 int		pthread_mutex_destroy(pthread_mutex_t *__mutex)
-		    __requires_unlocked(*__mutex);
+			__nonnull(1) __requires_unlocked(*__mutex);
 int		pthread_mutex_init(pthread_mutex_t *__mutex,
 			const pthread_mutexattr_t *)
-		    __requires_unlocked(*__mutex);
+			__nonnull(1) __requires_unlocked(*__mutex);
 int		pthread_mutex_lock(pthread_mutex_t *__mutex)
-                    __locks_exclusive(*__mutex);
+			__nonnull(1) __locks_exclusive(*__mutex);
 int		pthread_mutex_trylock(pthread_mutex_t *__mutex)
-                    __trylocks_exclusive(0, *__mutex);
+			__nonnull(1) __trylocks_exclusive(0, *__mutex);
 int		pthread_mutex_timedlock(pthread_mutex_t *__mutex,
 			const struct timespec *)
-                    __trylocks_exclusive(0, *__mutex);
+			__nonnull_all __trylocks_exclusive(0, *__mutex);
 int		pthread_mutex_unlock(pthread_mutex_t *__mutex)
-		    __unlocks(*__mutex);
-int		pthread_once(pthread_once_t *, void (*) (void));
+			__nonnull(1) __unlocks(*__mutex);
+int		pthread_once(pthread_once_t *, void (*) (void)) __nonnull_all;
 int		pthread_rwlock_destroy(pthread_rwlock_t *__rwlock)
-		    __requires_unlocked(*__rwlock);
+			__nonnull(1) __requires_unlocked(*__rwlock);
 int		pthread_rwlock_init(pthread_rwlock_t *__rwlock,
 			const pthread_rwlockattr_t *)
-		    __requires_unlocked(*__rwlock);
+			__nonnull(1) __requires_unlocked(*__rwlock);
 int		pthread_rwlock_rdlock(pthread_rwlock_t *__rwlock)
-                    __locks_shared(*__rwlock);
+			__nonnull(1) __locks_shared(*__rwlock);
 int		pthread_rwlock_timedrdlock(pthread_rwlock_t *__rwlock,
 			const struct timespec *)
-                    __trylocks_shared(0, *__rwlock);
+			__nonnull_all __trylocks_shared(0, *__rwlock);
 int		pthread_rwlock_timedwrlock(pthread_rwlock_t *__rwlock,
 			const struct timespec *)
-                    __trylocks_exclusive(0, *__rwlock);
+			__nonnull_all __trylocks_exclusive(0, *__rwlock);
 int		pthread_rwlock_tryrdlock(pthread_rwlock_t *__rwlock)
-                    __trylocks_shared(0, *__rwlock);
+			__nonnull(1) __trylocks_shared(0, *__rwlock);
 int		pthread_rwlock_trywrlock(pthread_rwlock_t *__rwlock)
-                    __trylocks_exclusive(0, *__rwlock);
+			__nonnull(1) __trylocks_exclusive(0, *__rwlock);
 int		pthread_rwlock_unlock(pthread_rwlock_t *__rwlock)
-		    __unlocks(*__rwlock);
+			__nonnull(1) __unlocks(*__rwlock);
 int		pthread_rwlock_wrlock(pthread_rwlock_t *__rwlock)
-                    __locks_exclusive(*__rwlock);
-int		pthread_rwlockattr_destroy(pthread_rwlockattr_t *);
+			__nonnull(1) __locks_exclusive(*__rwlock);
+int		pthread_rwlockattr_destroy(pthread_rwlockattr_t *)
+			__nonnull(1);
 int		pthread_rwlockattr_getkind_np(const pthread_rwlockattr_t *,
 			int *);
 int		pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *,
-			int *);
-int		pthread_rwlockattr_init(pthread_rwlockattr_t *);
+			int *) __nonnull_all;
+int		pthread_rwlockattr_init(pthread_rwlockattr_t *)
+			__nonnull(1);
 int		pthread_rwlockattr_setkind_np(pthread_rwlockattr_t *, int);
-int		pthread_rwlockattr_setpshared(pthread_rwlockattr_t *, int);
+int		pthread_rwlockattr_setpshared(pthread_rwlockattr_t *, int)
+			__nonnull(1);
 pthread_t	pthread_self(void);
 int		pthread_setspecific(pthread_key_t, const void *);
 
 int		pthread_spin_init(pthread_spinlock_t *__spin, int)
-		    __requires_unlocked(*__spin);
+			__requires_unlocked(*__spin);
 int		pthread_spin_destroy(pthread_spinlock_t *__spin)
-		    __requires_unlocked(*__spin);
+			__requires_unlocked(*__spin);
 int		pthread_spin_lock(pthread_spinlock_t *__spin)
-                    __locks_exclusive(*__spin);
+			__locks_exclusive(*__spin);
 int		pthread_spin_trylock(pthread_spinlock_t *__spin)
-                    __trylocks_exclusive(0, *__spin);
+			__trylocks_exclusive(0, *__spin);
 int		pthread_spin_unlock(pthread_spinlock_t *__spin)
-		    __unlocks(*__spin);
+			__unlocks(*__spin);
 int		pthread_cancel(pthread_t);
 int		pthread_setcancelstate(int, int *);
 int		pthread_setcanceltype(int, int *);
@@ -295,18 +312,20 @@ int		pthread_mutexattr_setprotocol(pthread_mutexattr_t *, int);
 
 int		pthread_attr_getinheritsched(const pthread_attr_t *, int *);
 int		pthread_attr_getschedparam(const pthread_attr_t *,
-			struct sched_param *);
-int		pthread_attr_getschedpolicy(const pthread_attr_t *, int *);
-int		pthread_attr_getscope(const pthread_attr_t *, int *);
+			struct sched_param *) __nonnull_all;
+int		pthread_attr_getschedpolicy(const pthread_attr_t *, int *)
+			__nonnull_all;
+int		pthread_attr_getscope(const pthread_attr_t *, int *)
+			__nonnull_all;
 int		pthread_attr_setinheritsched(pthread_attr_t *, int);
 int		pthread_attr_setschedparam(pthread_attr_t *,
-			const struct sched_param *);
-int		pthread_attr_setschedpolicy(pthread_attr_t *, int);
-int		pthread_attr_setscope(pthread_attr_t *, int);
+			const struct sched_param *) __nonnull(1) __nonnull(2);
+int		pthread_attr_setschedpolicy(pthread_attr_t *, int) __nonnull(1);
+int		pthread_attr_setscope(pthread_attr_t *, int) __nonnull(1);
 int		pthread_getschedparam(pthread_t pthread, int *,
-			struct sched_param *);
+			struct sched_param *) __nonnull(2) __nonnull(3);
 int		pthread_setschedparam(pthread_t, int,
-			const struct sched_param *);
+			const struct sched_param *) __nonnull(3);
 #if __XSI_VISIBLE
 int		pthread_getconcurrency(void);
 int		pthread_setconcurrency(int);
diff --git a/include/signal.h b/include/signal.h
index dca19aa..895ccc3 100644
--- a/include/signal.h
+++ b/include/signal.h
@@ -78,10 +78,10 @@ int	sigdelset(sigset_t *, int);
 int	sigemptyset(sigset_t *);
 int	sigfillset(sigset_t *);
 int	sigismember(const sigset_t *, int);
-int	sigpending(sigset_t *);
+int	sigpending(sigset_t *) __nonnull(1);
 int	sigprocmask(int, const sigset_t * __restrict, sigset_t * __restrict);
-int	sigsuspend(const sigset_t *);
-int	sigwait(const sigset_t * __restrict, int * __restrict);
+int	sigsuspend(const sigset_t *) __nonnull(1);
+int	sigwait(const sigset_t * __restrict, int * __restrict) __nonnull_all;
 #endif
 
 #if __POSIX_VISIBLE >= 199506 || __XSI_VISIBLE >= 600
diff --git a/include/stdlib.h b/include/stdlib.h
index 6669495..95db1b3 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -87,21 +87,22 @@ int	 atoi(const char *);
 long	 atol(const char *);
 void	*bsearch(const void *, const void *, size_t,
 	    size_t, int (*)(const void *, const void *));
-void	*calloc(size_t, size_t) __malloc_like;
+void	*calloc(size_t, size_t) __malloc_like __result_use_check
+	     __alloc_size(1) __alloc_size(2);
 div_t	 div(int, int) __pure2;
 _Noreturn void	 exit(int);
 void	 free(void *);
 char	*getenv(const char *);
 long	 labs(long) __pure2;
 ldiv_t	 ldiv(long, long) __pure2;
-void	*malloc(size_t) __malloc_like;
+void	*malloc(size_t) __malloc_like __result_use_check __alloc_size(1);
 int	 mblen(const char *, size_t);
 size_t	 mbstowcs(wchar_t * __restrict , const char * __restrict, size_t);
 int	 mbtowc(wchar_t * __restrict, const char * __restrict, size_t);
 void	 qsort(void *, size_t, size_t,
 	    int (*)(const void *, const void *));
 int	 rand(void);
-void	*realloc(void *, size_t);
+void	*realloc(void *, size_t) __result_use_check __alloc_size(2);
 void	 srand(unsigned);
 double	 strtod(const char * __restrict, char ** __restrict);
 float	 strtof(const char * __restrict, char ** __restrict);
@@ -155,7 +156,7 @@ _Noreturn void	 _Exit(int);
  * If we're in a mode greater than C99, expose C11 functions.
  */
 #if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
-void *	aligned_alloc(size_t, size_t) __malloc_like;
+void *	aligned_alloc(size_t, size_t) __malloc_like __alloc_size(2);
 int	at_quick_exit(void (*)(void));
 _Noreturn void
 	quick_exit(int);
@@ -170,7 +171,8 @@ char	*realpath(const char * __restrict, char * __restrict);
 int	 rand_r(unsigned *);			/* (TSF) */
 #endif
 #if __POSIX_VISIBLE >= 200112
-int	 posix_memalign(void **, size_t, size_t); /* (ADV) */
+int	 posix_memalign(void **, size_t, size_t) __nonnull(1)
+	    __alloc_size(3);			/* (ADV) */
 int	 setenv(const char *, const char *, int);
 int	 unsetenv(const char *);
 #endif
@@ -301,7 +303,7 @@ void	 qsort_r(void *, size_t, size_t, void *,
 	    int (*)(void *, const void *, const void *));
 int	 radixsort(const unsigned char **, int, const unsigned char *,
 	    unsigned);
-void    *reallocf(void *, size_t);
+void	*reallocf(void *, size_t) __result_use_check __alloc_size(2);
 int	 rpmatch(const char *);
 void	 setprogname(const char *);
 int	 sradixsort(const unsigned char **, int, const unsigned char *,