--- acgeneral-20081018.m4	2008-10-18 12:45:43.000000000 -0500
+++ acgeneral.m4	2023-12-31 21:42:41.000000000 -0600
@@ -1634,7 +1634,7 @@
 AC_CACHE_VAL(AC_CV_NAME,
 [ac_save_LIBS="$LIBS"
 LIBS="-l[]AC_LIB_NAME[] $4 $LIBS"
-AC_TRY_LINK( , [main()], AC_CV_NAME=yes, AC_CV_NAME=no)
+AC_TRY_LINK( , [int main(void)], AC_CV_NAME=yes, AC_CV_NAME=no)
 LIBS="$ac_save_LIBS"
 ])dnl
 AC_MSG_RESULT($AC_CV_NAME)
@@ -1733,7 +1733,7 @@
 [#]line __oline__ "configure"
 #include "confdefs.h"
 [$1]
-int main() {
+int main(void) {
 [$2]
 ; return 0; }
 ])EOF
@@ -1777,7 +1777,7 @@
 [#]line __oline__ "configure"
 #include "confdefs.h"
 [$1]
-int main() {
+int main(void) {
 [$2]
 ; return 0; }
 ])EOF
@@ -1988,7 +1988,11 @@
 AC_MSG_CHECKING(size of $1)
 AC_CACHE_VAL(AC_CV_NAME,
 [AC_TRY_RUN([#include <stdio.h>
-main()
+#if STDC_HEADERS
+#	include <stdlib.h>
+#	include <stddef.h>
+#endif
+int main(void)
 {
   FILE *f=fopen("conftestval", "w");
   if (!f) exit(1);
