[libc] minor fixes and improvements

share/libc/netdb.h

@@ -99,6 +99,14 @@ struct addrinfo
 # define NI_DGRAM	16	/* Look up UDP service rather than TCP.  */
 # define NI_NUMERICSCOPE 32
 
+// Non-POSIX
+#ifndef NI_MAXHOST
+# define NI_MAXHOST 1025
+#endif
+#ifndef NI_MAXSERV
+# define NI_MAXSERV 32
+#endif
+
 # define EAI_BADFLAGS	  -1	/* Invalid value for `ai_flags' field.  */
 # define EAI_NONAME	  -2	/* NAME or SERVICE is unknown.  */
 # define EAI_AGAIN	  -3	/* Temporary failure in name resolution.  */

share/libc/unistd.h

@@ -1079,7 +1079,12 @@ extern pid_t        setsid(void);
 */
 extern int          setuid(uid_t uid);
 
-extern unsigned int sleep(unsigned int);
+/*@
+  assigns \result \from seconds;
+  ensures unslept: 0 <= \result <= seconds;
+ */
+extern unsigned int sleep(unsigned int seconds);
+
 extern void         swab(const void *, void *, ssize_t);
 extern int          symlink(const char *, const char *);
 

tests/libc/netdb_c.c

@@ -12,14 +12,6 @@
 
 #define BUF_SIZE 500
 
-// Non-POSIX
-#ifndef NI_MAXHOST
-# define NI_MAXHOST 1025
-#endif
-#ifndef NI_MAXSERV
-# define NI_MAXSERV 32
-#endif
-
 int main() {
   struct addrinfo hints;
   struct addrinfo *result, *rp;

tests/libc/unistd_h.c

@@ -104,5 +104,8 @@ int main() {
   r = pipe(pipefd);
   //@ check ok: r == 0 || r == -1;
 
+  int unslept = sleep(42);
+  //@ assert 0 <= unslept <= 42;
+
   return 0;
 }