Installed-header hygiene (BZ#20366): time.h types.

[thirdparty/glibc.git] / time / asctime.c

diff --git a/time/asctime.c b/time/asctime.c
index 82e9f72f3f14eed6ec4366317810a3e2d510968e..763f12e88e4394abbe21ca37ba3829442459782c 100644 (file)
--- a/time/asctime.c
+++ b/time/asctime.c
@@ -1,41 +1,37 @@
-/* Copyright (C) 1991, 1993, 1995, 1996, 1997 Free Software Foundation, Inc.
+/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Library General Public License as
-   published by the Free Software Foundation; either version 2 of the
-   License, or (at your option) any later version.
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
 
    The GNU C Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Library General Public License for more details.
+   Lesser General Public License for more details.
 
-   You should have received a copy of the GNU Library General Public
-   License along with the GNU C Library; see the file COPYING.LIB.  If not,
-   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
 #include "../locale/localeinfo.h"
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <time.h>
 
+/* This is defined in locale/C-time.c in the GNU libc.  */
+extern const struct __locale_data _nl_C_LC_TIME attribute_hidden;
+#define ab_day_name(DAY) (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABDAY_1)+(DAY)].string)
+#define ab_month_name(MON) (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABMON_1)+(MON)].string)
 
 static const char format[] = "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n";
-static char result[             3+1+ 3+1+20+1+20+1+20+1+20+1+20+1 + 1];
-
-/* Returns a string of the form "Day Mon dd hh:mm:ss yyyy\n"
-   which is the representation of TP in that form.  */
-char *
-asctime (const struct tm *tp)
-{
-  return __asctime_r (tp, result);
-}
+static char result[             3+1+ 3+1+20+1+20+1+20+1+20+1+20+1 + 1];
 
 
-char *
-__asctime_r (const struct tm *tp, char *buf)
+static char *
+asctime_internal (const struct tm *tp, char *buf, size_t buflen)
 {
   if (tp == NULL)
     {
@@ -43,15 +39,51 @@ __asctime_r (const struct tm *tp, char *buf)
       return NULL;
     }
 
-  if (sprintf (buf, format,
-              (tp->tm_wday < 0 || tp->tm_wday >= 7 ?
-               "???" : _NL_CURRENT (LC_TIME, ABDAY_1 + tp->tm_wday)),
-              (tp->tm_mon < 0 || tp->tm_mon >= 12 ?
-               "???" : _NL_CURRENT (LC_TIME, ABMON_1 + tp->tm_mon)),
-              tp->tm_mday, tp->tm_hour, tp->tm_min,
-              tp->tm_sec, 1900 + tp->tm_year) < 0)
+  /* We limit the size of the year which can be printed.  Using the %d
+     format specifier used the addition of 1900 would overflow the
+     number and a negative vaue is printed.  For some architectures we
+     could in theory use %ld or an evern larger integer format but
+     this would mean the output needs more space.  This would not be a
+     problem if the 'asctime_r' interface would be defined sanely and
+     a buffer size would be passed.  */
+  if (__glibc_unlikely (tp->tm_year > INT_MAX - 1900))
+    {
+    eoverflow:
+      __set_errno (EOVERFLOW);
+      return NULL;
+    }
+
+  int n = __snprintf (buf, buflen, format,
+                     (tp->tm_wday < 0 || tp->tm_wday >= 7 ?
+                      "???" : ab_day_name (tp->tm_wday)),
+                     (tp->tm_mon < 0 || tp->tm_mon >= 12 ?
+                      "???" : ab_month_name (tp->tm_mon)),
+                     tp->tm_mday, tp->tm_hour, tp->tm_min,
+                     tp->tm_sec, 1900 + tp->tm_year);
+  if (n < 0)
     return NULL;
+  if (n >= buflen)
+    goto eoverflow;
 
   return buf;
 }
+
+
+/* Like asctime, but write result to the user supplied buffer.  The
+   buffer is only guaranteed to be 26 bytes in length.  */
+char *
+__asctime_r (const struct tm *tp, char *buf)
+{
+  return asctime_internal (tp, buf, 26);
+}
 weak_alias (__asctime_r, asctime_r)
+
+
+/* Returns a string of the form "Day Mon dd hh:mm:ss yyyy\n"
+   which is the representation of TP in that form.  */
+char *
+asctime (const struct tm *tp)
+{
+  return asctime_internal (tp, result, sizeof (result));
+}
+libc_hidden_def (asctime)