1 # parse-datetime.m4 serial 26
2 dnl Copyright (C) 2002-2006, 2008-2020 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],
18 [[struct s { int i, j; };]],
19 [[struct s t = (struct s) { 3, 4 };
20 if (t.i != 0) return 0;]])
22 [gl_cv_compound_literals=yes],
23 [gl_cv_compound_literals=no])
25 if test $gl_cv_compound_literals = yes; then
26 AC_DEFINE([HAVE_COMPOUND_LITERALS], [1],
27 [Define if you have compound literals.])
31 AC_DEFUN([gl_PARSE_DATETIME],
33 dnl parse-datetime.c is generated from parse-datetime.y. It requires bison,
34 dnl because parse-datetime.y uses bison specific features. It requires at
35 dnl least bison-2.4 for %define api.pure.
36 dnl bison is only needed for the maintainer (who touches parse-datetime.y).
37 dnl But in order to avoid separate Makefiles or --enable-maintainer-mode,
38 dnl we put the rule in general Makefile. Now, some people carelessly touch
39 dnl the files or have a broken "make" program, hence the parse-datetime.c
40 dnl rule will sometimes fire. To avoid an error, defines PARSE_DATETIME_BISON
41 dnl to ":" if it is not present or too old.
42 gl_PROG_BISON([PARSE_DATETIME_BISON], [2.4])
44 dnl Prerequisites of lib/parse-datetime.h.
45 AC_REQUIRE([AM_STDBOOL_H])
46 AC_REQUIRE([gl_TIMESPEC])
47 AC_REQUIRE([AC_C_RESTRICT])
49 dnl Prerequisites of lib/parse-datetime.y.
50 AC_REQUIRE([gl_BISON])
51 AC_REQUIRE([gl_C_COMPOUND_LITERALS])
53 AC_REQUIRE([gl_CLOCK_TIME])
54 AC_REQUIRE([gl_TM_GMTOFF])