Fixed main() prototypes in auto tests.

Future releases of GCC are planning to remove[0] default support for
some old features that were removed from C99 but GCC still accepts.

We can test for these changes by using the following -Werror=
directives

  -Werror=implicit-int
  -Werror=implicit-function-declaration
  -Werror=int-conversion
  -Werror=strict-prototypes
  -Werror=old-style-definition

Doing so revealed an issue with the auto/ tests in that the test
programs always define main as

  int main()

rather than

  int main(void)

which results in a bunch of errors like

build/autotest.c:3:23: error: function declaration isn't a prototype [-Werror=strict-prototypes]
    3 |                   int main() {
      |                       ^~~~
build/autotest.c: In function 'main':
build/autotest.c:3:23: error: old-style function definition [-Werror=old-style-definition]

The fix was easy, it only required fixing the main prototype with

  find -type f -exec sed -i 's/int main() {/int main(void) {/g' {} \;

Regardless of these upcoming GCC changes, this is probably a good thing
to do anyway for correctness.

[0]: https://fedoraproject.org/wiki/Changes/PortingToModernC

Link: <https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/CJXKTLXJUPZ4F2C2VQOTNMEA5JAUPMBD/>
Link: <https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/6SGHPHPAXKCVJ6PUZ57WVDQ5TDBVIRMF/>
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 16 insertions, 16 deletions

diff --git a/auto/sockets b/auto/sockets
index e344a3db..241b88eb 100644
--- a/auto/sockets
+++ b/auto/sockets
@@ -15,7 +15,7 @@ if [ $NXT_INET6 = YES ]; then
                       #include <sys/types.h>
                       #include <netinet/in.h>
 
-                      int main() {
+                      int main(void) {
                           struct sockaddr_in6  sin6;
 
                           sin6.sin6_family = AF_INET6;
@@ -36,7 +36,7 @@ nxt_feature_libs=
 nxt_feature_test="#include <stdio.h>
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       struct sockaddr  sa;
 
                       sa.sa_len = 0;
@@ -54,7 +54,7 @@ nxt_feature_libs=
 nxt_feature_test="#include <stdio.h>
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       printf(\"%d\", (int) sizeof(struct sockaddr));
                       return 0;
                   }"
@@ -70,7 +70,7 @@ nxt_feature_test="#include <stdio.h>
                   #include <sys/types.h>
                   #include <netinet/in.h>
 
-                  int main() {
+                  int main(void) {
                       printf(\"%d\", (int) sizeof(struct sockaddr_in));
                       return 0;
                   }"
@@ -86,7 +86,7 @@ nxt_feature_test="#include <stdio.h>
                   #include <sys/types.h>
                   #include <netinet/in.h>
 
-                  int main() {
+                  int main(void) {
                       printf(\"%d\", (int) sizeof(struct sockaddr_in6));
                       return 0;
                   }"
@@ -102,7 +102,7 @@ nxt_feature_test="#include <stdio.h>
                   #include <sys/types.h>
                   #include <sys/un.h>
 
-                  int main() {
+                  int main(void) {
                       printf(\"%d\", (int) sizeof(struct sockaddr_un));
                       return 0;
                   }"
@@ -117,7 +117,7 @@ nxt_feature_libs=
 nxt_feature_test="#include <stdio.h>
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       printf(\"%d\", (int) sizeof(struct sockaddr_storage));
                       return 0;
                   }"
@@ -132,7 +132,7 @@ nxt_feature_libs=
 nxt_feature_test="#include <stdio.h>
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       int  pair[2];
 
                       if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) != 0)
@@ -150,7 +150,7 @@ nxt_feature_libs=
 nxt_feature_test="#include <stdio.h>
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       struct  msghdr  msg;
 
                       printf(\"%d\", (int) sizeof(msg.msg_control));
@@ -175,7 +175,7 @@ if [ $NXT_SYSTEM != DragonFly ]; then
     nxt_feature_test="#define _GNU_SOURCE
                       #include <sys/socket.h>
 
-                      int main() {
+                      int main(void) {
                           return SO_PASSCRED == 0;
                       }"
     . auto/feature
@@ -191,7 +191,7 @@ if [ $NXT_SYSTEM != DragonFly ]; then
                           #include <sys/socket.h>
                           #include <sys/un.h>
 
-                          int main() {
+                          int main(void) {
                               return sizeof(struct ucred);
                           }"
         . auto/feature
@@ -206,7 +206,7 @@ if [ $NXT_SYSTEM != DragonFly ]; then
     nxt_feature_test="#define _GNU_SOURCE
                       #include <sys/socket.h>
 
-                      int main() {
+                      int main(void) {
                           return sizeof(struct cmsgcred);
                       }"
     . auto/feature
@@ -220,7 +220,7 @@ nxt_feature_incs=
 nxt_feature_libs=
 nxt_feature_test="#include <sys/filio.h>
 
-                  int main() {
+                  int main(void) {
                       return 0;
                   }"
 . auto/feature
@@ -235,7 +235,7 @@ nxt_feature_test="#include <unistd.h>
                   #include <sys/socket.h>
                   #include <sys/ioctl.h>
 
-                  int main() {
+                  int main(void) {
                       int  nb;
 
                       nb = 0;
@@ -255,7 +255,7 @@ nxt_feature_libs=
 nxt_feature_test="#define _GNU_SOURCE
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
                       return 0;
                   }"
@@ -273,7 +273,7 @@ nxt_feature_test="#define _GNU_SOURCE
                   #include <stdlib.h>
                   #include <sys/socket.h>
 
-                  int main() {
+                  int main(void) {
                       accept4(0, NULL, NULL, SOCK_NONBLOCK);
                       return 0;
                   }"