configure.ac: Fix -Wstrict-prototypes

Clang 16 now warns on this and it'll be removed in C23, so let's
just be future proof. It also reduces noise when doing general
Clang 16 porting work (which is a big job as it is).  github PR#355.

Signed-off-by: Sam James <sam@gentoo.org>

diff --git a/configure.ac b/configure.ac
index 1866aea53dc4a0e243885468e911b8ef9975705a..4bf758ac5a67e94dae6088eb4eb71c8b9d515949 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -713,7 +713,7 @@ case "$host" in
        AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <mach-o/dyld.h>
 #include <stdlib.h>
-int main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
+int main(void) { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
                exit(0);
        else
                exit(1);
@@ -1658,7 +1658,7 @@ AC_ARG_WITH(ldns,
 # include <stdint.h>
 #endif
 #include <ldns/ldns.h>
-int main() { ldns_status status = ldns_verify_trusted(NULL, NULL, NULL, NULL); status=LDNS_STATUS_OK; exit(0); }
+int main(void) { ldns_status status = ldns_verify_trusted(NULL, NULL, NULL, NULL); status=LDNS_STATUS_OK; exit(0); }
                        ]])
                ],
                        [AC_MSG_RESULT(yes)],
@@ -4262,7 +4262,7 @@ dnl test snprintf (broken on SCO w/gcc)
 #include <stdlib.h>
 #include <string.h>
 #ifdef HAVE_SNPRINTF
-int main()
+int main(void)
 {
        char buf[50];
        char expected_out[50];
@@ -4279,7 +4279,7 @@ int main()
        exit(0);
 }
 #else
-int main() { exit(0); }
+int main(void) { exit(0); }
 #endif
                ]])], [ true ], [ AC_DEFINE([BROKEN_SNPRINTF]) ],
                AC_MSG_WARN([cross compiling: Assuming working snprintf()])