[src/trunk]: src/lib/libc/time improve error checking (setting errno)

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/39202fdcb8c8
branches:  trunk
changeset: 803164:39202fdcb8c8
user:      christos <christos%NetBSD.org@localhost>
date:      Tue Oct 14 20:35:40 2014 +0000

description:
improve error checking (setting errno)

diffstat:

 lib/libc/time/localtime.c |  34 +++++++++++++++++++++-------------
 1 files changed, 21 insertions(+), 13 deletions(-)

diffs (123 lines):

diff -r 73de638daf28 -r 39202fdcb8c8 lib/libc/time/localtime.c
--- a/lib/libc/time/localtime.c Tue Oct 14 20:35:03 2014 +0000
+++ b/lib/libc/time/localtime.c Tue Oct 14 20:35:40 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: localtime.c,v 1.87 2014/10/07 21:51:03 christos Exp $  */
+/*     $NetBSD: localtime.c,v 1.88 2014/10/14 20:35:40 christos Exp $  */
 
 /*
 ** This file is in the public domain, so clarified as of
@@ -10,7 +10,7 @@
 #if 0
 static char    elsieid[] = "@(#)localtime.c    8.17";
 #else
-__RCSID("$NetBSD: localtime.c,v 1.87 2014/10/07 21:51:03 christos Exp $");
+__RCSID("$NetBSD: localtime.c,v 1.88 2014/10/14 20:35:40 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -250,6 +250,7 @@
                if (ttisp->tt_isdst == isdst)
                        return &sp->chars[ttisp->tt_abbrind];
        }
+       errno = ESRCH;
        return NULL;
 }
 
@@ -1353,8 +1354,10 @@
                                newt += seconds;
                        else    newt -= seconds;
                        if (newt < sp->ats[0] ||
-                               newt > sp->ats[sp->timecnt - 1])
-                                       return NULL;    /* "cannot happen" */
+                               newt > sp->ats[sp->timecnt - 1]) {
+                               errno = EINVAL;
+                               return NULL;    /* "cannot happen" */
+                       }
                        result = localsub(sp, &newt, offset, tmp);
                        if (result) {
                                int_fast64_t newy;
@@ -1363,8 +1366,10 @@
                                if (t < sp->ats[0])
                                        newy -= years;
                                else    newy += years;
-                               if (! (INT_MIN <= newy && newy <= INT_MAX))
+                               if (! (INT_MIN <= newy && newy <= INT_MAX)) {
+                                       errno = EOVERFLOW;
                                        return NULL;
+                               }
                                result->tm_year = (int)newy;
                        }
                        return result;
@@ -1398,7 +1403,7 @@
                        tzname[result->tm_isdst] =
                            __UNCONST(&sp->chars[ttisp->tt_abbrind]);
 #ifdef TM_ZONE
-               tmp->TM_ZONE = __UNCONST(&sp->chars[ttisp->tt_abbrind]);
+               result->TM_ZONE = __UNCONST(&sp->chars[ttisp->tt_abbrind]);
 #endif /* defined TM_ZONE */
        }
        return result;
@@ -1456,8 +1461,9 @@
        ** "UT+xxxx" or "UT-xxxx" if offset is non-zero,
        ** but this is no time for a treasure hunt.
        */
-       tmp->TM_ZONE = offset ? __UNCONST(wildabbr) : gmtptr ? gmtptr->chars :
-           __UNCONST(gmt);
+       if (result)
+               result->TM_ZONE = offset ? __UNCONST(wildabbr) : gmtptr ?
+                   gmtptr->chars : __UNCONST(gmt);
 #endif /* defined TM_ZONE */
        return result;
 }
@@ -1575,14 +1581,14 @@
                tdelta = tdays / DAYSPERLYEAR;
                if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta)
                       && tdelta <= INT_MAX))
-                       return NULL;
+                      goto overflow;
                _DIAGASSERT(__type_fit(int, tdelta));
                idelta = (int)tdelta;
                if (idelta == 0)
                        idelta = (tdays < 0) ? -1 : 1;
                newy = y;
                if (increment_overflow(&newy, idelta))
-                       return NULL;
+                       goto overflow;
                leapdays = leaps_thru_end_of(newy - 1) -
                        leaps_thru_end_of(y - 1);
                tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
@@ -1611,13 +1617,13 @@
        }
        while (idays < 0) {
                if (increment_overflow(&y, -1))
-                       return NULL;
+                       goto overflow;
                idays += year_lengths[isleap(y)];
        }
        while (idays >= year_lengths[isleap(y)]) {
                idays -= year_lengths[isleap(y)];
                if (increment_overflow(&y, 1))
-                       return NULL;
+                       goto overflow;
        }
        tmp->tm_year = y;
        if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
@@ -1652,6 +1658,9 @@
        tmp->TM_GMTOFF = offset;
 #endif /* defined TM_GMTOFF */
        return tmp;
+overflow:
+       errno = EOVERFLOW;
+       return NULL;
 }
 
 char *
@@ -2131,7 +2140,6 @@
 mktime_tzname(timezone_t sp, struct tm *tmp, bool setname)
 {
        if (sp)
-/*###2133 [lint] warning argument has incompatible pointer type, arg #2 (pointer to function != pointer to function) [153]%%%*/
                return time1(tmp, localsub, sp, setname);
        else {
                gmtcheck();