+{ echo "$as_me:$LINENO: checking whether __attribute__((unused)) can be used without warnings" >&5
+echo $ECHO_N "checking whether __attribute__((unused)) can be used without warnings... $ECHO_C" >&6; }
+if test "${ac_cv___attribute___unused+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS $ac_lbl_cc_force_warning_errors"
+cat >conftest.$ac_ext <<_ACEOF
+
+ /* confdefs.h. */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h. */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+int
+main(int argc __attribute((unused)), char **argv __attribute((unused)))
+{
+ printf("Hello, world!\n");
+ return 0;
+}
+
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+ *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+ *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+ (eval "$ac_compile") 2>conftest.er1
+ ac_status=$?
+ grep -v '^ *+' conftest.er1 >conftest.err
+ rm -f conftest.er1
+ cat conftest.err >&5
+ echo "$as_me:$LINENO: \$? = $ac_status" >&5
+ (exit $ac_status); } && {
+ test -z "$ac_c_werror_flag" ||
+ test ! -s conftest.err
+ } && test -s conftest.$ac_objext; then
+ ac_cv___attribute___unused=yes
+else
+ echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ ac_cv___attribute___unused=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+CFLAGS="$save_CFLAGS"
+if test "$ac_cv___attribute___unused" = "yes"; then
+ V_DEFS="$V_DEFS -D_U_=\"__attribute__((unused))\""
+else
+ V_DEFS="$V_DEFS -D_U_=\"\""
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv___attribute___unused" >&5
+echo "${ECHO_T}$ac_cv___attribute___unused" >&6; }
+
+
+{ echo "$as_me:$LINENO: checking whether __attribute__((noreturn)) can be applied to function pointers without warnings" >&5
+echo $ECHO_N "checking whether __attribute__((noreturn)) can be applied to function pointers without warnings... $ECHO_C" >&6; }
+if test "${ac_cv___attribute___noreturn_function_pointer+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS $ac_lbl_cc_force_warning_errors"
+cat >conftest.$ac_ext <<_ACEOF
+
+ /* confdefs.h. */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h. */
+
+#include <stdlib.h>
+
+extern int (*foo)(int i)
+ __attribute__ ((noreturn));
+
+int
+main(int argc, char **argv)
+{
+ (*foo)(1);
+}
+
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+ *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+ *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+ (eval "$ac_compile") 2>conftest.er1
+ ac_status=$?
+ grep -v '^ *+' conftest.er1 >conftest.err
+ rm -f conftest.er1
+ cat conftest.err >&5
+ echo "$as_me:$LINENO: \$? = $ac_status" >&5
+ (exit $ac_status); } && {
+ test -z "$ac_c_werror_flag" ||
+ test ! -s conftest.err
+ } && test -s conftest.$ac_objext; then
+ ac_cv___attribute___noreturn_function_pointer=yes
+else
+ echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ ac_cv___attribute___noreturn_function_pointer=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+CFLAGS="$save_CFLAGS"
+if test "$ac_cv___attribute___noreturn_function_pointer" = "yes"; then
+
+cat >>confdefs.h <<\_ACEOF
+#define __ATTRIBUTE___NORETURN_OK_FOR_FUNCTION_POINTERS 1
+_ACEOF
+
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv___attribute___noreturn_function_pointer" >&5
+echo "${ECHO_T}$ac_cv___attribute___noreturn_function_pointer" >&6; }
+
+
+{ echo "$as_me:$LINENO: checking whether __attribute__((format)) can be used without warnings" >&5
+echo $ECHO_N "checking whether __attribute__((format)) can be used without warnings... $ECHO_C" >&6; }
+if test "${ac_cv___attribute___format+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+save_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS $ac_lbl_cc_force_warning_errors"
+cat >conftest.$ac_ext <<_ACEOF
+
+ /* confdefs.h. */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h. */
+
+#include <stdlib.h>
+
+extern int foo(const char *fmt, ...)
+ __attribute__ ((format (printf, 1, 2)));
+
+int
+main(int argc, char **argv)
+{
+ foo("%s", "test");
+}
+
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+ *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+ *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+ (eval "$ac_compile") 2>conftest.er1
+ ac_status=$?
+ grep -v '^ *+' conftest.er1 >conftest.err
+ rm -f conftest.er1
+ cat conftest.err >&5
+ echo "$as_me:$LINENO: \$? = $ac_status" >&5
+ (exit $ac_status); } && {
+ test -z "$ac_c_werror_flag" ||
+ test ! -s conftest.err
+ } && test -s conftest.$ac_objext; then
+ ac_cv___attribute___format=yes
+else
+ echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ ac_cv___attribute___format=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+CFLAGS="$save_CFLAGS"
+if test "$ac_cv___attribute___format" = "yes"; then
+
+cat >>confdefs.h <<\_ACEOF
+#define __ATTRIBUTE___FORMAT_OK 1
+_ACEOF
+
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv___attribute___format" >&5
+echo "${ECHO_T}$ac_cv___attribute___format" >&6; }
+
+ if test "$ac_cv___attribute___format" = "yes"; then
+