Enforce strict prototypes

i3 will now compile with no warnings when -Wstrict-prototypes is used.

.travis.yml

@@ -35,7 +35,7 @@ install:
 script:
   - docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 ${BASENAME} ./travis/check-safe-wrappers.sh
   - docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 ${BASENAME} ./travis/check-formatting.sh
-  - docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 -e CC ${BASENAME} /bin/sh -c 'autoreconf -fi && mkdir -p build && cd build && (../configure || (cat config.log; false)) && make -j CFLAGS="-Wformat -Wformat-security -Wextra -Wno-unused-parameter -Werror"'
+  - docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 -e CC ${BASENAME} /bin/sh -c 'autoreconf -fi && mkdir -p build && cd build && (../configure || (cat config.log; false)) && make -j CFLAGS="-Wformat -Wformat-security -Wextra -Wno-unused-parameter -Wstrict-prototypes -Werror"'
   - docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 ${BASENAME} ./travis/check-spelling.pl
   - docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 -e CC ${BASENAME} ./travis/run-tests.sh
   - ./travis/skip-pkg.sh || docker run -v $PWD:/usr/src/i3/ -w /usr/src/i3 ${BASENAME} ./travis/debian-build.sh deb/debian-amd64/DIST

i3-config-wizard/main.c

@@ -104,7 +104,7 @@ static struct xkb_keymap *xkb_keymap;
 static uint8_t xkb_base_event;
 static uint8_t xkb_base_error;
 
-static void finish();
+static void finish(void);
 
 #include "GENERATED_config_enums.h"
 
@@ -482,7 +482,7 @@ static void txt(int col, int row, char *text, color_t fg, color_t bg) {
  * Handles expose events, that is, draws the window contents.
  *
  */
-static int handle_expose() {
+static int handle_expose(void) {
     const color_t black = draw_util_hex_to_color("#000000");
     const color_t white = draw_util_hex_to_color("#FFFFFF");
     const color_t green = draw_util_hex_to_color("#00FF00");
@@ -641,7 +641,7 @@ static void handle_button_press(xcb_button_press_event_t *event) {
  * Creates the config file and tells i3 to reload.
  *
  */
-static void finish() {
+static void finish(void) {
     printf("creating \"%s\"...\n", config_path);
 
     struct xkb_context *xkb_context;

i3-input/main.c

@@ -156,7 +156,7 @@ static int handle_key_release(void *ignored, xcb_connection_t *conn, xcb_key_rel
     return 1;
 }
 
-static void finish_input() {
+static void finish_input(void) {
     char *command = (char *)concat_strings(glyphs_utf8, input_position);
 
     /* count the occurrences of %s in the string */

i3bar/include/xcb.h

@@ -60,7 +60,7 @@ int separator_symbol_width;
  * depend on 'config'.
  *
  */
-char *init_xcb_early();
+char *init_xcb_early(void);
 
 /**
  * Initialization which depends on 'config' being usable. Called after the

i3bar/src/xcb.c

@@ -1185,7 +1185,7 @@ void xcb_io_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
  * depend on 'config'.
  *
  */
-char *init_xcb_early() {
+char *init_xcb_early(void) {
     /* FIXME: xcb_connect leaks memory */
     xcb_connection = xcb_connect(NULL, &screen);
     if (xcb_connection_has_error(xcb_connection)) {
@@ -1248,7 +1248,7 @@ char *init_xcb_early() {
  * in xcb.
  *
  */
-void register_xkb_keyevents() {
+void register_xkb_keyevents(void) {
     const xcb_query_extension_reply_t *extreply;
     extreply = xcb_get_extension_data(conn, &xcb_xkb_id);
     if (!extreply->present) {
@@ -1272,7 +1272,7 @@ void register_xkb_keyevents() {
  * Deregister from xkb keyevents.
  *
  */
-void deregister_xkb_keyevents() {
+void deregister_xkb_keyevents(void) {
     xcb_xkb_select_events(conn,
                           XCB_XKB_ID_USE_CORE_KBD,
                           0,

include/configuration.h

@@ -427,7 +427,7 @@ void ungrab_all_keys(xcb_connection_t *conn);
  * Sends the current bar configuration as an event to all barconfig_update listeners.
  *
  */
-void update_barconfig();
+void update_barconfig(void);
 
 /**
  * Kills the configerror i3-nagbar process, if any.

include/libi3.h

@@ -472,7 +472,7 @@ xcb_visualtype_t *get_visualtype(xcb_screen_t *screen);
  * release version), based on the git version number.
  *
  */
-bool is_debug_build() __attribute__((const));
+bool is_debug_build(void) __attribute__((const));
 
 /**
  * Returns the name of a temporary file with the specified prefix.

libi3/is_debug_build.c

@@ -15,7 +15,7 @@
  * release version), based on the git version number.
  *
  */
-bool is_debug_build() {
+bool is_debug_build(void) {
     /* i3_version contains either something like this:
      *     "4.0.2 (2011-11-11, branch "release")".
      * or: "4.0.2-123-gCOFFEEBABE (2011-11-11, branch "next")".

src/config.c

@@ -32,7 +32,7 @@ void ungrab_all_keys(xcb_connection_t *conn) {
  * Sends the current bar configuration as an event to all barconfig_update listeners.
  *
  */
-void update_barconfig() {
+void update_barconfig(void) {
     Barconfig *current;
     TAILQ_FOREACH(current, &barconfigs, configs) {
         ipc_send_barconfig_update_event(current);

src/x.c

@@ -1254,7 +1254,7 @@ void x_set_name(Con *con, const char *name) {
  * Set up the I3_SHMLOG_PATH atom.
  *
  */
-void update_shmlog_atom() {
+void update_shmlog_atom(void) {
     if (*shmlogname == '\0') {
         xcb_delete_property(conn, root, A_I3_SHMLOG_PATH);
     } else {