From ee4983302d6f052e77ab0332d2a128d169c2eacb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arsen=20Arsenovi=C4=87?= <arsen@aarsen.me>
Date: Tue, 15 Nov 2022 21:45:27 +0100
Subject: [PATCH] Remove default-int/k&r declarations from the configure macros

Recently, Clang tried to switch to having K&R prototypes and other
non-strictly-conforming prototypes error out, as a result of C2x changes
to the standard.  These have been located across many packages, and
range in severity from mild compile errors to runtime misconfiguration
as a result of broken configure scripts.

This covers all the instances I could find by grepping around the
codebase, and gets OpenLDAP building on my system.

Bug: https://bugs.gentoo.org/871288
Bug: https://bugs.gentoo.org/871372
--- a/build/openldap.m4
+++ b/build/openldap.m4
@@ -154,6 +154,7 @@ fi
 if test $ol_cv_header_stdc = yes; then
   # /bin/cc in Irix-4.0.5 gets non-ANSI ctype macros unless using -ansi.
 AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <ctype.h>
+#include <stdlib.h>
 #ifndef HAVE_EBCDIC
 #	define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
 #	define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
@@ -394,9 +395,7 @@ AC_DEFUN([OL_PTHREAD_TEST_FUNCTION],[[
 AC_DEFUN([OL_PTHREAD_TEST_PROGRAM],
 [AC_LANG_SOURCE([OL_PTHREAD_TEST_INCLUDES
 
-int main(argc, argv)
-	int argc;
-	char **argv;
+int main(int argc, char **argv)
 {
 OL_PTHREAD_TEST_FUNCTION
 }
@@ -518,7 +517,7 @@ AC_CACHE_CHECK([for compatible POSIX regex],ol_cv_c_posix_regex,[
 #include <sys/types.h>
 #include <regex.h>
 static char *pattern, *string;
-main()
+int main(void)
 {
 	int rc;
 	regex_t re;
@@ -545,7 +544,8 @@ AC_DEFUN([OL_C_UPPER_LOWER],
 [AC_CACHE_CHECK([if toupper() requires islower()],ol_cv_c_upper_lower,[
 	AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <ctype.h>
-main()
+#include <stdlib.h>
+int main(void)
 {
 	if ('C' == toupper('C'))
 		exit(0);
@@ -603,7 +603,7 @@ AC_DEFUN([OL_NONPOSIX_STRERROR_R],
 			]])],[ol_cv_nonposix_strerror_r=yes],[ol_cv_nonposix_strerror_r=no])
 	else
 		AC_RUN_IFELSE([AC_LANG_SOURCE([[
-			main() {
+			int main(void) {
 				char buf[100];
 				buf[0] = 0;
 				strerror_r( 1, buf, sizeof buf );
--- a/configure.ac
+++ b/configure.ac
@@ -1031,7 +1031,11 @@ dnl ----------------------------------------------------------------
 AC_CHECK_HEADERS( sys/epoll.h )
 if test "${ac_cv_header_sys_epoll_h}" = yes; then
 	AC_MSG_CHECKING(for epoll system call)
-	AC_RUN_IFELSE([AC_LANG_SOURCE([[int main(int argc, char **argv)
+	AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdlib.h>
+#ifdef HAVE_SYS_POLL_H
+#include <sys/epoll.h>
+#endif
+int main(int argc, char **argv)
 {
 	int epfd = epoll_create(256);
 	exit (epfd == -1 ? 1 : 0);
@@ -1493,10 +1497,8 @@ pthread_rwlock_t rwlock;
 				dnl save the flags
 				AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 #include <pthread.h>
-#ifndef NULL
-#define NULL (void*)0
-#endif
-]], [[pthread_detach(NULL);]])],[ol_cv_func_pthread_detach=yes],[ol_cv_func_pthread_detach=no])
+pthread_t thread;
+]], [[pthread_detach(thread);]])],[ol_cv_func_pthread_detach=yes],[ol_cv_func_pthread_detach=no])
 			])
 
 			if test $ol_cv_func_pthread_detach = no ; then
@@ -1551,6 +1553,9 @@ dnl			esac
 				AC_CACHE_CHECK([if select yields when using pthreads],
 					ol_cv_pthread_select_yields,[
 				AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#define _XOPEN_SOURCE 500               /* For pthread_setconcurrency() on glibc */
+#include <stdlib.h>
+#include <stdio.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <unistd.h>
@@ -1561,8 +1566,7 @@ dnl			esac
 
 static int fildes[2];
 
-static void *task(p)
-	void *p;
+static void *task(void *p)
 {
 	int i;
 	struct timeval tv;
@@ -1586,9 +1590,7 @@ static void *task(p)
 	exit(0); /* if we exit here, the select blocked the whole process */
 }
 
-int main(argc, argv)
-	int argc;
-	char **argv;
+int main(int argc, char **argv)
 {
 	pthread_t t;
 
--- a/contrib/ldaptcl/tclAppInit.c
+++ b/contrib/ldaptcl/tclAppInit.c
@@ -45,9 +45,7 @@ EXTERN int		Tcltest_Init _ANSI_ARGS_((Tcl_Interp *interp));
  */
 
 int
-main(argc, argv)
-    int argc;			/* Number of command-line arguments. */
-    char **argv;		/* Values of command-line arguments. */
+main(int argc, char **argv)
 {
 #ifdef USE_TCLX
     TclX_Main(argc, argv, Tcl_AppInit);
--- a/contrib/ldaptcl/tkAppInit.c
+++ b/contrib/ldaptcl/tkAppInit.c
@@ -37,16 +37,9 @@ int (*tclDummyMathPtr)() = matherr;
  * This is the main program for the application.
  *-----------------------------------------------------------------------------
  */
-#ifdef __cplusplus
 int
 main (int    argc,
       char **argv)
-#else
-int
-main (argc, argv)
-    int    argc;
-    char **argv;
-#endif
 {
 #ifdef USE_TCLX
     TkX_Main(argc, argv, Tcl_AppInit);
@@ -68,14 +61,8 @@ main (argc, argv)
  * interp->result if an error occurs.
  *-----------------------------------------------------------------------------
  */
-#ifdef __cplusplus
 int
 Tcl_AppInit (Tcl_Interp *interp)
-#else
-int
-Tcl_AppInit (interp)
-    Tcl_Interp *interp;
-#endif
 {
     if (Tcl_Init (interp) == TCL_ERROR) {
         return TCL_ERROR;
--- a/servers/slapd/syslog.c
+++ b/servers/slapd/syslog.c
@@ -209,7 +209,7 @@ openlog(const char *ident, int logstat, int logfac)
 }
 
 void
-closelog()
+closelog(void)
 {
 	(void)close(LogFile);
 	LogFile = -1;
-- 
2.38.1