1 # parse-datetime.m4 serial 19
2 dnl Copyright (C) 2002-2006, 2008-2011 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 dnl Define HAVE_COMPOUND_LITERALS if the C compiler supports compound literals
9 dnl Note that compound literals such as (struct s) { 3, 4 } can be used for
10 dnl initialization of stack-allocated variables, but are not constant
11 dnl expressions and therefore cannot be used as initializer for global or
12 dnl static variables (even though gcc supports this in pre-C99 mode).
13 AC_DEFUN([gl_C_COMPOUND_LITERALS],
15 AC_CACHE_CHECK([for compound literals], [gl_cv_compound_literals],
16 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[struct s { int i, j; };]],
17 [[struct s t = (struct s) { 3, 4 };
18 if (t.i != 0) return 0;]])],
19 gl_cv_compound_literals=yes,
20 gl_cv_compound_literals=no)])
21 if test $gl_cv_compound_literals = yes; then
22 AC_DEFINE([HAVE_COMPOUND_LITERALS], [1],
23 [Define if you have compound literals.])
27 AC_DEFUN([gl_PARSE_DATETIME],
29 dnl Prerequisites of lib/parse-datetime.h.
30 AC_REQUIRE([AM_STDBOOL_H])
31 AC_REQUIRE([gl_TIMESPEC])
33 dnl Prerequisites of lib/parse-datetime.y.
34 AC_REQUIRE([gl_BISON])
35 AC_REQUIRE([gl_C_COMPOUND_LITERALS])
37 AC_REQUIRE([gl_CLOCK_TIME])
38 AC_REQUIRE([gl_TM_GMTOFF])
41 #include <time.h> /* for time_t */
42 #include <limits.h> /* for CHAR_BIT, LONG_MIN, LONG_MAX */
43 #define TYPE_MINIMUM(t) \
44 ((t) ((t) 0 < (t) -1 ? (t) 0 : ~ TYPE_MAXIMUM (t)))
45 #define TYPE_MAXIMUM(t) \
46 ((t) ((t) 0 < (t) -1 \
48 : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
49 typedef int verify_min[2 * (LONG_MIN <= TYPE_MINIMUM (time_t)) - 1];
50 typedef int verify_max[2 * (TYPE_MAXIMUM (time_t) <= LONG_MAX) - 1];
52 [AC_DEFINE([TIME_T_FITS_IN_LONG_INT], [1],
53 [Define to 1 if all 'time_t' values fit in a 'long int'.])