libgfortran/intrinsics/ctime.c

   1 /* Implementation of the CTIME and FDATE g77 intrinsics.
   2    Copyright (C) 2005-2013 Free Software Foundation, Inc.
   3    Contributed by François-Xavier Coudert <coudert@clipper.ens.fr>
   4
   5 This file is part of the GNU Fortran runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU General Public
   9 License as published by the Free Software Foundation; either
  10 version 3 of the License, or (at your option) any later version.
  11
  12 Libgfortran is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27
  28 #include "time_1.h"
  29
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33
  34 /* strftime-like function that fills a C string with %c format which
  35    is identical to ctime in the default locale. As ctime and ctime_r
  36    are poorly specified and their usage not recommended, the
  37    implementation instead uses strftime.  */
  38
  39 static size_t
  40 strctime (char *s, size_t max, const time_t *timep)
  41 {
  42   struct tm ltm;
  43   int failed;
  44   /* Some targets provide a localtime_r based on a draft of the POSIX
  45      standard where the return type is int rather than the
  46      standardized struct tm*.  */
  47   __builtin_choose_expr (__builtin_classify_type (localtime_r (timep, &ltm))
  48                          == 5,
  49                          failed = localtime_r (timep, &ltm) == NULL,
  50                          failed = localtime_r (timep, &ltm) != 0);
  51   if (failed)
  52     return 0;
  53   return strftime (s, max, "%c", &ltm);
  54 }
  55
  56 /* In the default locale, the date and time representation fits in 26
  57    bytes. However, other locales might need more space.  */
  58 #define CSZ 100
  59
  60 extern void fdate (char **, gfc_charlen_type *);
  61 export_proto(fdate);
  62
  63 void
  64 fdate (char ** date, gfc_charlen_type * date_len)
  65 {
  66   time_t now = time(NULL);
  67   *date = xmalloc (CSZ);
  68   *date_len = strctime (*date, CSZ, &now);
  69 }
  70
  71
  72 extern void fdate_sub (char *, gfc_charlen_type);
  73 export_proto(fdate_sub);
  74
  75 void
  76 fdate_sub (char * date, gfc_charlen_type date_len)
  77 {
  78   time_t now = time(NULL);
  79   char *s = xmalloc (date_len + 1);
  80   size_t n = strctime (s, date_len + 1, &now);
  81   fstrcpy (date, date_len, s, n);
  82   free (s);
  83 }
  84
  85
  86
  87 extern void PREFIX(ctime) (char **, gfc_charlen_type *, GFC_INTEGER_8);
  88 export_proto_np(PREFIX(ctime));
  89
  90 void
  91 PREFIX(ctime) (char ** date, gfc_charlen_type * date_len, GFC_INTEGER_8 t)
  92 {
  93   time_t now = t;
  94   *date = xmalloc (CSZ);
  95   *date_len = strctime (*date, CSZ, &now);
  96 }
  97
  98
  99 extern void ctime_sub (GFC_INTEGER_8 *, char *, gfc_charlen_type);
 100 export_proto(ctime_sub);
 101
 102 void
 103 ctime_sub (GFC_INTEGER_8 * t, char * date, gfc_charlen_type date_len)
 104 {
 105   time_t now = *t;
 106   char *s = xmalloc (date_len + 1);
 107   size_t n = strctime (s, date_len + 1, &now);
 108   fstrcpy (date, date_len, s, n);
 109   free (s);
 110 }