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Diffstat (limited to 'm4/parse-datetime.m4')
-rw-r--r-- | m4/parse-datetime.m4 | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/m4/parse-datetime.m4 b/m4/parse-datetime.m4 new file mode 100644 index 0000000..3c5320e --- /dev/null +++ b/m4/parse-datetime.m4 @@ -0,0 +1,54 @@ +# parse-datetime.m4 serial 27 +dnl Copyright (C) 2002-2006, 2008-2022 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +dnl Define HAVE_COMPOUND_LITERALS if the C compiler supports compound literals +dnl as in ISO C99. +dnl Note that compound literals such as (struct s) { 3, 4 } can be used for +dnl initialization of stack-allocated variables, but are not constant +dnl expressions and therefore cannot be used as initializer for global or +dnl static variables (even though gcc supports this in pre-C99 mode). +AC_DEFUN([gl_C_COMPOUND_LITERALS], +[ + AC_CACHE_CHECK([for compound literals], [gl_cv_compound_literals], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[struct s { int i, j; };]], + [[struct s t = (struct s) { 3, 4 }; + if (t.i != 0) return 0;]]) + ], + [gl_cv_compound_literals=yes], + [gl_cv_compound_literals=no]) + ]) + if test $gl_cv_compound_literals = yes; then + AC_DEFINE([HAVE_COMPOUND_LITERALS], [1], + [Define if you have compound literals.]) + fi +]) + +AC_DEFUN([gl_PARSE_DATETIME], +[ + dnl parse-datetime.c is generated from parse-datetime.y. It requires bison, + dnl because parse-datetime.y uses bison specific features. It requires at + dnl least bison-2.4 for %define api.pure. + dnl bison is only needed for the maintainer (who touches parse-datetime.y). + dnl But in order to avoid separate Makefiles or --enable-maintainer-mode, + dnl we put the rule in general Makefile. Now, some people carelessly touch + dnl the files or have a broken "make" program, hence the parse-datetime.c + dnl rule will sometimes fire. To avoid an error, defines PARSE_DATETIME_BISON + dnl to ":" if it is not present or too old. + gl_PROG_BISON([PARSE_DATETIME_BISON], [2.4]) + + dnl Prerequisites of lib/parse-datetime.h. + AC_REQUIRE([gl_TIMESPEC]) + AC_REQUIRE([AC_C_RESTRICT]) + + dnl Prerequisites of lib/parse-datetime.y. + AC_REQUIRE([gl_BISON]) + AC_REQUIRE([gl_C_COMPOUND_LITERALS]) + AC_STRUCT_TIMEZONE + AC_REQUIRE([gl_CLOCK_TIME]) + AC_REQUIRE([gl_TM_GMTOFF]) +]) |