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, 8 insertions, 8 deletions

diff --git a/auto/threads b/auto/threads
index ff33eaac..67b46690 100644
--- a/auto/threads
+++ b/auto/threads
@@ -47,7 +47,7 @@ nxt_feature_libs=$NXT_PTHREAD
 nxt_feature_test="#define _GNU_SOURCE
               #include <pthread.h>
 
-              int main() {
+              int main(void) {
                   pthread_yield();
                   return 0;
               }"
@@ -65,7 +65,7 @@ if [ $nxt_found = no ]; then
     nxt_feature_libs=$NXT_PTHREAD
     nxt_feature_test="#include <pthread.h>
 
-                  int main() {
+                  int main(void) {
                       pthread_yield_np();
                       return 0;
                   }"
@@ -82,7 +82,7 @@ nxt_feature_incs=
 nxt_feature_libs=$NXT_PTHREAD
 nxt_feature_test="#include <pthread.h>
 
-              int main() {
+              int main(void) {
                   pthread_spinlock_t  lock;
 
                   if (pthread_spin_init(&lock, PTHREAD_PROCESS_PRIVATE) != 0)
@@ -112,7 +112,7 @@ if [ $nxt_found = yes ]; then
 
                       pthread_spinlock_t  lock = 0;
 
-                      int main() {
+                      int main(void) {
                           if (pthread_spin_trylock(&lock) != 0)
                               return 1;
                           if (pthread_spin_unlock(&lock) != 0)
@@ -130,7 +130,7 @@ nxt_feature_incs=
 nxt_feature_libs=
 nxt_feature_test="#include <semaphore.h>
 
-                  int main() {
+                  int main(void) {
                       sem_t            sem;
                       struct timespec  ts;
 
@@ -199,7 +199,7 @@ nxt_feature_test="#include <pthread.h>
                       return NULL;
                   }
 
-                  int main() {
+                  int main(void) {
                       void       *n;
                       pthread_t  pt;
 
@@ -227,7 +227,7 @@ if [ $nxt_found = no ]; then
     nxt_feature_libs=$NXT_PTHREAD
     nxt_feature_test="#include <pthread.h>
 
-                      int main() {
+                      int main(void) {
                           pthread_key_t  key = -1;
 
                           if (pthread_key_create(&key, NULL))
@@ -250,7 +250,7 @@ if [ $nxt_found = no ]; then
                       #include <pthread.h>
                       #include <stdio.h>
 
-                      int main() {
+                      int main(void) {
                           printf(\"%d\", PTHREAD_KEYS_MAX);
                           return 0;
                       }"