https://github.com/xiph/flac/pull/521

From afd9e9006d2c18d184db098bec0a0618cb4f0283 Mon Sep 17 00:00:00 2001
From: Sam James <sam@gentoo.org>
Date: Wed, 23 Nov 2022 03:31:30 +0000
Subject: [PATCH] libFLAC.m4, libFLAC++.m4: fix -Wstrict-prototypes

Signed-off-by: Sam James <sam@gentoo.org>
--- a/src/libFLAC++/libFLAC++.m4
+++ b/src/libFLAC++/libFLAC++.m4
@@ -57,7 +57,7 @@ dnl
 #include <string.h>
 #include <FLAC++/decoder.h>
 
-int main ()
+int main (void)
 {
   system("touch conf.libFLAC++test");
   return 0;
--- a/src/libFLAC/libFLAC.m4
+++ b/src/libFLAC/libFLAC.m4
@@ -58,7 +58,7 @@ dnl
 #include <string.h>
 #include <FLAC/format.h>
 
-int main ()
+int main (void)
 {
   system("touch conf.libFLACtest");
   return 0;