libgfortran/intrinsics/ctime.c

   1 /* Implementation of the CTIME and FDATE g77 intrinsics.
   2    Copyright (C) 2005-2014 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 /* Maximum space a ctime-like string might need. A "normal" ctime
  35    string is 26 bytes, and in our case 24 bytes as we don't include
  36    the trailing newline and null. However, the longest possible year
  37    number is -2,147,481,748 (1900 - 2,147,483,648, since tm_year is a
  38    32-bit signed integer) so an extra 7 bytes are needed. */
  39 #define CTIME_BUFSZ 31
  40
  41
  42 /* Thread-safe ctime-like function that fills a Fortran
  43    string. ctime_r is a portability headache and marked as obsolescent
  44    in POSIX 2008, which recommends strftime in its place. However,
  45    strftime(..., "%c",...)  doesn't produce ctime-like output on
  46    MinGW, so do it manually with snprintf.  */
  47
  48 static int
  49 gf_ctime (char *s, size_t max, const time_t timev)
  50 {
  51   struct tm ltm;
  52   int failed;
  53   char buf[CTIME_BUFSZ + 1];
  54   /* Some targets provide a localtime_r based on a draft of the POSIX
  55      standard where the return type is int rather than the
  56      standardized struct tm*.  */
  57   __builtin_choose_expr (__builtin_classify_type (localtime_r (&timev, &ltm))
  58                          == 5,
  59                          failed = localtime_r (&timev, &ltm) == NULL,
  60                          failed = localtime_r (&timev, &ltm) != 0);
  61   if (failed)
  62     goto blank;
  63   int n = snprintf (buf, sizeof (buf),
  64                     "%3.3s %3.3s%3d %.2d:%.2d:%.2d %d",
  65                     "SunMonTueWedThuFriSat" + ltm.tm_wday * 3,
  66                     "JanFebMarAprMayJunJulAugSepOctNovDec" + ltm.tm_mon * 3,
  67                     ltm.tm_mday, ltm.tm_hour, ltm.tm_min, ltm.tm_sec,
  68                     1900 + ltm.tm_year);
  69   if (n < 0)
  70     goto blank;
  71   if ((size_t) n <= max)
  72     {
  73       cf_strcpy (s, max, buf);
  74       return n;
  75     }
  76  blank:
  77   memset (s, ' ', max);
  78   return 0;
  79 }
  80
  81
  82 extern void fdate (char **, gfc_charlen_type *);
  83 export_proto(fdate);
  84
  85 void
  86 fdate (char ** date, gfc_charlen_type * date_len)
  87 {
  88   time_t now = time(NULL);
  89   *date = xmalloc (CTIME_BUFSZ);
  90   *date_len = gf_ctime (*date, CTIME_BUFSZ, now);
  91 }
  92
  93
  94 extern void fdate_sub (char *, gfc_charlen_type);
  95 export_proto(fdate_sub);
  96
  97 void
  98 fdate_sub (char * date, gfc_charlen_type date_len)
  99 {
 100   time_t now = time(NULL);
 101   gf_ctime (date, date_len, now);
 102 }
 103
 104
 105
 106 extern void PREFIX(ctime) (char **, gfc_charlen_type *, GFC_INTEGER_8);
 107 export_proto_np(PREFIX(ctime));
 108
 109 void
 110 PREFIX(ctime) (char ** date, gfc_charlen_type * date_len, GFC_INTEGER_8 t)
 111 {
 112   time_t now = t;
 113   *date = xmalloc (CTIME_BUFSZ);
 114   *date_len = gf_ctime (*date, CTIME_BUFSZ, now);
 115 }
 116
 117
 118 extern void ctime_sub (GFC_INTEGER_8 *, char *, gfc_charlen_type);
 119 export_proto(ctime_sub);
 120
 121 void
 122 ctime_sub (GFC_INTEGER_8 * t, char * date, gfc_charlen_type date_len)
 123 {
 124   time_t now = *t;
 125   gf_ctime (date, date_len, now);
 126 }