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Hash :
7b089321
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Date :
2025-01-01T09:24:36
maint: run 'make update-copyright'
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# stdnoreturn.m4
# serial 1
dnl Copyright 2012-2025 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 This file is offered as-is, without any warranty.
# Check for stdnoreturn.h that conforms to C11.
# Prepare for substituting <stdnoreturn.h> if it is not supported.
AC_DEFUN([gl_STDNORETURN_H],
[
AC_REQUIRE([AC_CANONICAL_HOST])
case "$host_os" in
cygwin*)
dnl Regardless whether a working <stdnoreturn.h> exists or not,
dnl we need our own <stdnoreturn.h>, because of the definition
dnl of _Noreturn done by gnulib-common.m4.
GL_GENERATE_STDNORETURN_H=true
;;
*)
AC_CACHE_CHECK([for working stdnoreturn.h],
[gl_cv_header_working_stdnoreturn_h],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <stdlib.h>
#include <stdnoreturn.h>
#if defined _WIN32 && !defined __CYGWIN__
# include <process.h>
#endif
/* Do not check for 'noreturn' after the return type.
C11 allows it, but it's rarely done that way
and circa-2012 bleeding-edge GCC rejects it when given
-Werror=old-style-declaration. */
noreturn void foo1 (void) { exit (0); }
_Noreturn void foo2 (void) { exit (0); }
int testit (int argc, char **argv)
{
if (argc & 1)
return 0;
(argv[0][0] ? foo1 : foo2) ();
}
]])],
[gl_cv_header_working_stdnoreturn_h=yes],
[gl_cv_header_working_stdnoreturn_h=no])])
if test $gl_cv_header_working_stdnoreturn_h = yes; then
GL_GENERATE_STDNORETURN_H=false
else
GL_GENERATE_STDNORETURN_H=true
fi
;;
esac
])