1 # Check for stdnoreturn.h that conforms to C11.
3 dnl Copyright 2012-2020 Free Software Foundation, Inc.
4 dnl This file is free software; the Free Software Foundation
5 dnl gives unlimited permission to copy and/or distribute it,
6 dnl with or without modifications, as long as this notice is preserved.
8 # Prepare for substituting <stdnoreturn.h> if it is not supported.
10 AC_DEFUN([gl_STDNORETURN_H],
12 AC_REQUIRE([AC_CANONICAL_HOST])
15 dnl Regardless whether a working <stdnoreturn.h> exists or not,
16 dnl we need our own <stdnoreturn.h>, because of the definition
17 dnl of _Noreturn done by gnulib-common.m4.
18 STDNORETURN_H='stdnoreturn.h'
21 AC_CACHE_CHECK([for working stdnoreturn.h],
22 [gl_cv_header_working_stdnoreturn_h],
26 #include <stdnoreturn.h>
27 #if defined _WIN32 && !defined __CYGWIN__
30 /* Do not check for 'noreturn' after the return type.
31 C11 allows it, but it's rarely done that way
32 and circa-2012 bleeding-edge GCC rejects it when given
33 -Werror=old-style-declaration. */
34 noreturn void foo1 (void) { exit (0); }
35 _Noreturn void foo2 (void) { exit (0); }
36 int testit (int argc, char **argv)
40 (argv[0][0] ? foo1 : foo2) ();
43 [gl_cv_header_working_stdnoreturn_h=yes],
44 [gl_cv_header_working_stdnoreturn_h=no])])
45 if test $gl_cv_header_working_stdnoreturn_h = yes; then
48 STDNORETURN_H='stdnoreturn.h'
52 AC_SUBST([STDNORETURN_H])
53 AM_CONDITIONAL([GL_GENERATE_STDNORETURN_H], [test -n "$STDNORETURN_H"])