+# Check for stdnoreturn.h that conforms to C11.
+
+dnl Copyright 2012 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.
+
+# Prepare for substituting <stdnoreturn.h> if it is not supported.
+
+AC_DEFUN([gl_STDNORETURN_H],
+[
+ 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>
+ void noreturn foo1 (void) { exit (0); }
+ void _Noreturn foo2 (void) { exit (0); }
+ noreturn void foo3 (void) { exit (0); }
+ _Noreturn void foo4 (void) { exit (0); }
+ int main (int argc, char **argv) {
+ if (argc & 1)
+ return 0;
+ ((argv[0][0]
+ ? (argv[0][1] ? foo1 : foo2)
+ : (argv[0][1] ? foo3 : foo4))
+ ());
+ }
+ ]])],
+ [gl_cv_header_working_stdnoreturn_h=yes],
+ [gl_cv_header_working_stdnoreturn_h=no])])
+
+ if test $gl_cv_header_working_stdnoreturn_h = yes; then
+ STDNORETURN_H=''
+ else
+ STDNORETURN_H='stdnoreturn.h'
+ fi
+
+ AC_SUBST([STDNORETURN_H])
+ AM_CONDITIONAL([GL_GENERATE_STDNORETURN_H], [test -n "$STDNORETURN_H"])
+])