timespec: fill in other members

This problem was found when compiling GNU Emacs with
--enable-gcc-warnings on a platform where tv_sec is 64 bits and
tv_nsec is 32 bits, and struct timespec has padding.  GCC
-Wuse-of-uninitialized-value complained when a struct timespec
initialized only via assigning to tv_sec and tv_nsec was copied
via assignment (this was in lib/timespec.h’s make_timespec).
Although behavior is well-defined on this platform, the warning is
annoying and the behavior might not be well-defined on theoretical
platforms where struct timespec has other members.  To work around
this, initialize all the struct’s members.
* lib/getsockopt.c (rpl_getsockopt):
* lib/gettime.c (gettime):
* lib/gettimeofday.c (gettimeofday):
* lib/glthread/thread.c (gl_thread_self):
* lib/nanosleep.c (nanosleep):
* lib/parse-datetime.y (digits_to_date_time, set_hhmmss)
(signed_seconds, unsigned_seconds, yylex, parse_datetime_body):
* lib/poll.c (poll):
* lib/pselect.c (pselect):
* lib/pthread-cond.c (endlessly, pthread_cond_timedwait):
* lib/pthread-rwlock.c (pthread_rwlock_timedrdlock)
(pthread_rwlock_timedwrlock):
* lib/pthread_mutex_timedlock.c (pthread_mutex_timedlock):
* lib/select.c (rpl_select):
* lib/settime.c (settime):
* lib/stat-time.h (get_stat_atime, get_stat_ctime)
(get_stat_mtime, get_stat_birthtime):
* lib/thrd.c (rpl_thrd_current):
* lib/timespec.h (make_timespec):
* lib/timespec_getres.c (timespec_getres):
* lib/utimecmp.c (utimecmpat):
* lib/utimens.c (fdutimens):
When filling in a struct timespec or similar time-related structure
that might be copied elsewhere, also assign to any storage other
than tv_sec and tv_nsec, to avoid undefined behavior on (likely
theoretical) platforms where struct timespec has other members,
and also to avoid warnings from GCC and/or valgrind.

1 files changed, 7 insertions, 10 deletions

diff --git a/lib/parse-datetime.y b/lib/parse-datetime.y
index 45c5e43415..a0487a3713 100644
--- a/lib/parse-datetime.y
+++ b/lib/parse-datetime.y
@@ -281,8 +281,7 @@ digits_to_date_time (parser_control *pc, textint text_int)
               pc->hour = text_int.value / 100;
               pc->minutes = text_int.value % 100;
             }
-          pc->seconds.tv_sec = 0;
-          pc->seconds.tv_nsec = 0;
+          pc->seconds = (struct timespec) {0};
           pc->meridian = MER24;
         }
     }
@@ -320,8 +319,7 @@ set_hhmmss (parser_control *pc, intmax_t hour, intmax_t minutes,
 {
   pc->hour = hour;
   pc->minutes = minutes;
-  pc->seconds.tv_sec = sec;
-  pc->seconds.tv_nsec = nsec;
+  pc->seconds = (struct timespec) { .tv_sec = sec, .tv_nsec = nsec };
 }
 
 /* Return a textual representation of the day ordinal/number values
@@ -966,14 +964,14 @@ signed_seconds:
     tSDECIMAL_NUMBER
   | tSNUMBER
       { if (time_overflow ($1.value)) YYABORT;
-        $$.tv_sec = $1.value; $$.tv_nsec = 0; }
+        $$ = (struct timespec) { .tv_sec = $1.value }; }
   ;
 
 unsigned_seconds:
     tUDECIMAL_NUMBER
   | tUNUMBER
       { if (time_overflow ($1.value)) YYABORT;
-        $$.tv_sec = $1.value; $$.tv_nsec = 0; }
+        $$ = (struct timespec) { .tv_sec = $1.value }; }
   ;
 
 number:
@@ -1480,8 +1478,8 @@ yylex (union YYSTYPE *lvalp, parser_control *pc)
                   ns = BILLION - ns;
                 }
 
-              lvalp->timespec.tv_sec = s;
-              lvalp->timespec.tv_nsec = ns;
+              lvalp->timespec = (struct timespec) { .tv_sec = s,
+                                                    .tv_nsec = ns };
               pc->input = p;
               return sign ? tSDECIMAL_NUMBER : tUDECIMAL_NUMBER;
             }
@@ -1812,8 +1810,7 @@ parse_datetime_body (struct timespec *result, char const *p,
   pc.day = tmp.tm_mday;
   pc.hour = tmp.tm_hour;
   pc.minutes = tmp.tm_min;
-  pc.seconds.tv_sec = tmp.tm_sec;
-  pc.seconds.tv_nsec = Start_ns;
+  pc.seconds = (struct timespec) { .tv_sec = tmp.tm_sec, .tv_nsec = Start_ns };
   tm.tm_isdst = tmp.tm_isdst;
 
   pc.meridian = MER24;