Fix warning for Android NDK compiler: "function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]"

https://stackoverflow.com/questions/42125/warning-error-function-declaration-isnt-a-prototype
In C int foo() and int foo(void) are different functions. int foo() accepts an arbitrary number of arguments, while int foo(void) accepts 0 arguments. In C++ they mean the same thing.

src/core/android/SDL_android.c

@@ -842,18 +842,18 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeDropFile)(
 }
 
 /* Lock / Unlock Mutex */
-void Android_ActivityMutex_Lock()
+void Android_ActivityMutex_Lock(void)
 {
     SDL_LockMutex(Android_ActivityMutex);
 }
 
-void Android_ActivityMutex_Unlock()
+void Android_ActivityMutex_Unlock(void)
 {
     SDL_UnlockMutex(Android_ActivityMutex);
 }
 
 /* Lock the Mutex when the Activity is in its 'Running' state */
-void Android_ActivityMutex_Lock_Running()
+void Android_ActivityMutex_Lock_Running(void)
 {
     int pauseSignaled = 0;
     int resumeSignaled = 0;
@@ -1439,13 +1439,13 @@ void Android_JNI_SetOrientation(int w, int h, int resizable, const char *hint)
     (*env)->DeleteLocalRef(env, jhint);
 }
 
-void Android_JNI_MinizeWindow()
+void Android_JNI_MinizeWindow(void)
 {
     JNIEnv *env = Android_JNI_GetEnv();
     (*env)->CallStaticVoidMethod(env, mActivityClass, midMinimizeWindow);
 }
 
-SDL_bool Android_JNI_ShouldMinimizeOnFocusLoss()
+SDL_bool Android_JNI_ShouldMinimizeOnFocusLoss(void)
 {
     JNIEnv *env = Android_JNI_GetEnv();
     return (*env)->CallStaticBooleanMethod(env, mActivityClass, midShouldMinimizeOnFocusLoss);
@@ -1879,7 +1879,7 @@ static SDL_bool Android_JNI_ExceptionOccurred(SDL_bool silent)
     return SDL_FALSE;
 }
 
-static void Internal_Android_Create_AssetManager()
+static void Internal_Android_Create_AssetManager(void)
 {
 
     struct LocalReferenceHolder refs = LocalReferenceHolder_Setup(__FUNCTION__);
@@ -1918,7 +1918,7 @@ static void Internal_Android_Create_AssetManager()
     LocalReferenceHolder_Cleanup(&refs);
 }
 
-static void Internal_Android_Destroy_AssetManager()
+static void Internal_Android_Destroy_AssetManager(void)
 {
     JNIEnv *env = Android_JNI_GetEnv();
 
@@ -2153,7 +2153,7 @@ int Android_JNI_GetPowerInfo(int *plugged, int *charged, int *battery, int *seco
 }
 
 /* Add all touch devices */
-void Android_JNI_InitTouch()
+void Android_JNI_InitTouch(void)
 {
     JNIEnv *env = Android_JNI_GetEnv();
     (*env)->CallStaticVoidMethod(env, mActivityClass, midInitTouch);

src/core/freebsd/SDL_evdev_kbd_freebsd.c

@@ -134,7 +134,7 @@ static void kbd_cleanup_signal_action(int signum, siginfo_t *info, void *ucontex
     SDL_EVDEV_kbd_reraise_signal(signum);
 }
 
-static void kbd_unregister_emerg_cleanup()
+static void kbd_unregister_emerg_cleanup(void)
 {
     int tabidx, signum;
 

src/core/linux/SDL_evdev_kbd.c

@@ -214,7 +214,7 @@ static void kbd_cleanup_signal_action(int signum, siginfo_t *info, void *ucontex
     SDL_EVDEV_kbd_reraise_signal(signum);
 }
 
-static void kbd_unregister_emerg_cleanup()
+static void kbd_unregister_emerg_cleanup(void)
 {
     int tabidx, signum;
 

src/core/linux/SDL_fcitx.c

@@ -55,7 +55,7 @@ typedef struct _FcitxClient
 
 static FcitxClient fcitx_client;
 
-static char *GetAppName()
+static char *GetAppName(void)
 {
 #if defined(__LINUX__) || defined(__FREEBSD__)
     char *spot;
@@ -368,7 +368,7 @@ static Uint32 Fcitx_ModState(void)
     return fcitx_mods;
 }
 
-SDL_bool SDL_Fcitx_Init()
+SDL_bool SDL_Fcitx_Init(void)
 {
     fcitx_client.dbus = SDL_DBus_GetContext();
 
@@ -380,7 +380,7 @@ SDL_bool SDL_Fcitx_Init()
     return FcitxClientCreateIC(&fcitx_client);
 }
 
-void SDL_Fcitx_Quit()
+void SDL_Fcitx_Quit(void)
 {
     FcitxClientICCallMethod(&fcitx_client, "DestroyIC");
     if (fcitx_client.ic_path) {

src/core/linux/SDL_ime.c

@@ -40,7 +40,7 @@ static _SDL_IME_ProcessKeyEvent SDL_IME_ProcessKeyEvent_Real = NULL;
 static _SDL_IME_UpdateTextRect SDL_IME_UpdateTextRect_Real = NULL;
 static _SDL_IME_PumpEvents SDL_IME_PumpEvents_Real = NULL;
 
-static void InitIME()
+static void InitIME(void)
 {
     static SDL_bool inited = SDL_FALSE;
 #ifdef HAVE_FCITX
@@ -142,7 +142,7 @@ void SDL_IME_UpdateTextRect(const SDL_Rect *rect)
     }
 }
 
-void SDL_IME_PumpEvents()
+void SDL_IME_PumpEvents(void)
 {
     if (SDL_IME_PumpEvents_Real) {
         SDL_IME_PumpEvents_Real();

src/core/linux/SDL_threadprio.c

@@ -79,7 +79,7 @@ static SDL_bool realtime_portal_supported(DBusConnection *conn)
                                               "RTTimeUSecMax", DBUS_TYPE_INT64, &res);
 }
 
-static void set_rtkit_interface()
+static void set_rtkit_interface(void)
 {
     SDL_DBusContext *dbus = SDL_DBus_GetContext();
 
@@ -108,7 +108,7 @@ static DBusConnection *get_rtkit_dbus_connection()
     return NULL;
 }
 
-static void rtkit_initialize()
+static void rtkit_initialize(void)
 {
     DBusConnection *dbus_conn;
 
@@ -134,7 +134,7 @@ static void rtkit_initialize()
     }
 }
 
-static SDL_bool rtkit_initialize_realtime_thread()
+static SDL_bool rtkit_initialize_realtime_thread(void)
 {
     // Following is an excerpt from rtkit README that outlines the requirements
     // a thread must meet before making rtkit requests:

src/core/openbsd/SDL_wscons_kbd.c

@@ -449,7 +449,7 @@ static SDL_WSCONS_input_data *SDL_WSCONS_Init_Keyboard(const char *dev)
     return input;
 }
 
-void SDL_WSCONS_Init()
+void SDL_WSCONS_Init(void)
 {
     inputs[0] = SDL_WSCONS_Init_Keyboard("/dev/wskbd0");
     inputs[1] = SDL_WSCONS_Init_Keyboard("/dev/wskbd1");
@@ -460,7 +460,7 @@ void SDL_WSCONS_Init()
     return;
 }
 
-void SDL_WSCONS_Quit()
+void SDL_WSCONS_Quit(void)
 {
     int i = 0;
     SDL_WSCONS_input_data *input = NULL;
@@ -921,7 +921,7 @@ static void updateKeyboard(SDL_WSCONS_input_data *input)
     }
 }
 
-void SDL_WSCONS_PumpEvents()
+void SDL_WSCONS_PumpEvents(void)
 {
     int i = 0;
     for (i = 0; i < 4; i++) {