gcc/libgfortran/intrinsics/ctime.c
2022-01-03 10:42:10 +01:00

126 lines
3.7 KiB
C

/* Implementation of the CTIME and FDATE g77 intrinsics.
Copyright (C) 2005-2022 Free Software Foundation, Inc.
Contributed by François-Xavier Coudert <coudert@clipper.ens.fr>
This file is part of the GNU Fortran runtime library (libgfortran).
Libgfortran is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
Libgfortran 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 General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "libgfortran.h"
#include "time_1.h"
#include <string.h>
/* Maximum space a ctime-like string might need. A "normal" ctime
string is 26 bytes, and in our case 24 bytes as we don't include
the trailing newline and null. However, the longest possible year
number is -2,147,481,748 (1900 - 2,147,483,648, since tm_year is a
32-bit signed integer) so an extra 7 bytes are needed. */
#define CTIME_BUFSZ 31
/* Thread-safe ctime-like function that fills a Fortran
string. ctime_r is a portability headache and marked as obsolescent
in POSIX 2008, which recommends strftime in its place. However,
strftime(..., "%c",...) doesn't produce ctime-like output on
MinGW, so do it manually with snprintf. */
static int
gf_ctime (char *s, size_t max, const time_t timev)
{
struct tm ltm;
int failed;
char buf[CTIME_BUFSZ + 1];
/* Some targets provide a localtime_r based on a draft of the POSIX
standard where the return type is int rather than the
standardized struct tm*. */
__builtin_choose_expr (__builtin_classify_type (localtime_r (&timev, &ltm))
== 5,
failed = localtime_r (&timev, &ltm) == NULL,
failed = localtime_r (&timev, &ltm) != 0);
if (failed)
goto blank;
int n = snprintf (buf, sizeof (buf),
"%3.3s %3.3s%3d %.2d:%.2d:%.2d %d",
"SunMonTueWedThuFriSat" + ltm.tm_wday * 3,
"JanFebMarAprMayJunJulAugSepOctNovDec" + ltm.tm_mon * 3,
ltm.tm_mday, ltm.tm_hour, ltm.tm_min, ltm.tm_sec,
1900 + ltm.tm_year);
if (n < 0)
goto blank;
if ((size_t) n <= max)
{
cf_strcpy (s, max, buf);
return n;
}
blank:
memset (s, ' ', max);
return 0;
}
extern void fdate (char **, gfc_charlen_type *);
export_proto(fdate);
void
fdate (char ** date, gfc_charlen_type * date_len)
{
time_t now = time(NULL);
*date = xmalloc (CTIME_BUFSZ);
*date_len = gf_ctime (*date, CTIME_BUFSZ, now);
}
extern void fdate_sub (char *, gfc_charlen_type);
export_proto(fdate_sub);
void
fdate_sub (char * date, gfc_charlen_type date_len)
{
time_t now = time(NULL);
gf_ctime (date, date_len, now);
}
extern void PREFIX(ctime) (char **, gfc_charlen_type *, GFC_INTEGER_8);
export_proto_np(PREFIX(ctime));
void
PREFIX(ctime) (char ** date, gfc_charlen_type * date_len, GFC_INTEGER_8 t)
{
time_t now = t;
*date = xmalloc (CTIME_BUFSZ);
*date_len = gf_ctime (*date, CTIME_BUFSZ, now);
}
extern void ctime_sub (GFC_INTEGER_8 *, char *, gfc_charlen_type);
export_proto(ctime_sub);
void
ctime_sub (GFC_INTEGER_8 * t, char * date, gfc_charlen_type date_len)
{
time_t now = *t;
gf_ctime (date, date_len, now);
}