[3.10] GH-99086: Fix -Wstrict-prototypes, -Wimplicit-function-declara… (#99920)

[3.10] gh-99086: Fix -Wstrict-prototypes, -Wimplicit-function-declaration warnings in configure.ac (GH-99406)

Follow up to 12078e7.
(cherry picked from commit e35ca41)

Co-authored-by: Sam James <sam@gentoo.org>

Author: thesamesam

Misc/NEWS.d/next/Build/2022-11-24-02-58-10.gh-issue-99086.DV_4Br.rst

@@ -0,0 +1 @@
+Fix ``-Wimplicit-int``, ``-Wstrict-prototypes``, and ``-Wimplicit-function-declaration`` compiler warnings in :program:`configure` checks.

configure

@@ -5929,7 +5929,7 @@ if test "x$enable_profiling" = xyes; then
   CC="$CC -pg"
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-int main() { return 0; }
+int main(void) { return 0; }
 _ACEOF
 if ac_fn_c_try_link "$LINENO"; then :
 
@@ -7752,7 +7752,7 @@ else
 
 void* routine(void* p){return NULL;}
 
-int main(){
+int main(void){
   pthread_t p;
   if(pthread_create(&p,NULL,routine,NULL)!=0)
     return 1;
@@ -7808,7 +7808,7 @@ else
 
 void* routine(void* p){return NULL;}
 
-int main(){
+int main(void){
   pthread_t p;
   if(pthread_create(&p,NULL,routine,NULL)!=0)
     return 1;
@@ -7858,7 +7858,7 @@ else
 
 void* routine(void* p){return NULL;}
 
-int main(){
+int main(void){
   pthread_t p;
   if(pthread_create(&p,NULL,routine,NULL)!=0)
     return 1;
@@ -7908,7 +7908,7 @@ else
 
 void* routine(void* p){return NULL;}
 
-int main(){
+int main(void){
   pthread_t p;
   if(pthread_create(&p,NULL,routine,NULL)!=0)
     return 1;
@@ -10447,7 +10447,7 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-int main()
+int main(void)
 {
     char s[16];
     int i, *p1, *p2;
@@ -11024,6 +11024,7 @@ $as_echo_n "checking for pthread_create in -lpthread... " >&6; }
 /* end confdefs.h.  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <pthread.h>
 
 void * start_routine (void *arg) { exit (0); }
@@ -11325,7 +11326,7 @@ else
       void *foo(void *parm) {
         return NULL;
       }
-      int main() {
+      int main(void) {
         pthread_attr_t attr;
         pthread_t id;
         if (pthread_attr_init(&attr)) return (-1);
@@ -12687,7 +12688,7 @@ else
 
 #include <sys/stat.h>
 #include <unistd.h>
-int main(int argc, char*argv[])
+int main(int argc, char *argv[])
 {
   if(chflags(argv[0], 0) != 0)
     return 1;
@@ -12736,7 +12737,7 @@ else
 
 #include <sys/stat.h>
 #include <unistd.h>
-int main(int argc, char*argv[])
+int main(int argc, char *argv[])
 {
   if(lchflags(argv[0], 0) != 0)
     return 1;
@@ -13653,7 +13654,7 @@ else
 #include <sys/socket.h>
 #include <netinet/in.h>
 
-int main()
+int main(void)
 {
   int passive, gaierr, inet4 = 0, inet6 = 0;
   struct addrinfo hints, *ai, *aitop;
@@ -14880,7 +14881,7 @@ else
 
 #include <stdlib.h>
 #include <math.h>
-int main() {
+int main(void) {
     volatile double x, y, z;
     /* 1./(1-2**-53) -> 1+2**-52 (correct), 1.0 (double rounding) */
     x = 0.99999999999999989; /* 1-2**-53 */
@@ -15730,7 +15731,7 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-int main()
+int main(void)
 {
 	return (((-1)>>3 == -1) ? 0 : 1);
 }
@@ -16178,7 +16179,7 @@ else
 
 #include <stdlib.h>
 #include <unistd.h>
-int main()
+int main(void)
 {
 	int val1 = nice(1);
 	if (val1 != -1 && val1 == nice(2))
@@ -16221,7 +16222,7 @@ else
 #include <poll.h>
 #include <unistd.h>
 
-int main()
+int main(void)
 {
     struct pollfd poll_struct = { 42, POLLIN|POLLPRI|POLLOUT, 0 };
     int poll_test;
@@ -16279,7 +16280,7 @@ else
 extern char *tzname[];
 #endif
 
-int main()
+int main(void)
 {
 	/* Note that we need to ensure that not only does tzset(3)
 	   do 'something' with localtime, but it works as documented
@@ -17040,9 +17041,10 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
+#include <stddef.h>
 #include <stdio.h>
-#include<stdlib.h>
-int main() {
+#include <stdlib.h>
+int main(void) {
     size_t len = -1;
     const char *str = "text";
     len = mbstowcs(NULL, str, 0);
@@ -17219,7 +17221,7 @@ else
 #include <stdlib.h>
 #include <string.h>
 void foo(void *p, void *q) { memmove(p, q, 19); }
-int main() {
+int main(void) {
   char a[32] = "123456789000000000";
   foo(&a[9], a);
   if (strcmp(a, "123456789123456789000000000") != 0)
@@ -17274,7 +17276,7 @@ else
               );
               return r;
             }
-            int main() {
+            int main(void) {
               int p = 8;
               if ((foo(&p) ? : p) != 6)
                 return 1;
@@ -17313,7 +17315,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
     #include <stdatomic.h>
     atomic_int int_var;
     atomic_uintptr_t uintptr_var;
-    int main() {
+    int main(void) {
       atomic_store_explicit(&int_var, 5, memory_order_relaxed);
       atomic_store_explicit(&uintptr_var, 0, memory_order_relaxed);
       int loaded_value = atomic_load_explicit(&int_var, memory_order_seq_cst);
@@ -17347,7 +17349,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 
 
     int val;
-    int main() {
+    int main(void) {
       __atomic_store_n(&val, 1, __ATOMIC_SEQ_CST);
       (void)__atomic_load_n(&val, __ATOMIC_SEQ_CST);
       return 0;
@@ -17406,7 +17408,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 
     #include <dirent.h>
 
-    int main() {
+    int main(void) {
       struct dirent entry;
       return entry.d_type == DT_UNKNOWN;
     }
@@ -17436,11 +17438,12 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 
+    #include <stddef.h>
     #include <unistd.h>
     #include <sys/syscall.h>
     #include <linux/random.h>
 
-    int main() {
+    int main(void) {
         char buffer[1];
         const size_t buflen = sizeof(buffer);
         const int flags = GRND_NONBLOCK;
@@ -17475,9 +17478,10 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 
+    #include <stddef.h>
     #include <sys/random.h>
 
-    int main() {
+    int main(void) {
         char buffer[1];
         const size_t buflen = sizeof(buffer);
         const int flags = 0;