Fix build errors with -Werror and NDEBUG

To reproduce:

    meson setup build -Db_ndebug=true --werror
    meson compile -C build

backend/wayland/backend.c

@@ -213,11 +213,10 @@ static void linux_dmabuf_feedback_v1_handle_tranche_formats(void *data,
 		return;
 	}
 
-	size_t table_cap = feedback_data->format_table_size /
-		sizeof(struct wlr_wl_linux_dmabuf_v1_table_entry);
 	uint16_t *index_ptr;
 	wl_array_for_each(index_ptr, indices_arr) {
-		assert(*index_ptr < table_cap);
+		assert(*index_ptr < feedback_data->format_table_size /
+			sizeof(struct wlr_wl_linux_dmabuf_v1_table_entry));
 		const struct wlr_wl_linux_dmabuf_v1_table_entry *entry =
 			&feedback_data->format_table[*index_ptr];
 		wlr_drm_format_set_add(&feedback_data->backend->linux_dmabuf_v1_formats,

examples/pointer.c

@@ -96,8 +96,7 @@ static void output_frame_notify(struct wl_listener *listener, void *data) {
 	struct sample_output *sample_output = wl_container_of(listener, sample_output, frame);
 	struct sample_state *state = sample_output->state;
 	struct wlr_output *wlr_output = sample_output->output;
-	struct wlr_renderer *renderer = state->renderer;
-	assert(renderer);
+	assert(state->renderer);
 
 	struct wlr_output_state output_state;
 	wlr_output_state_init(&output_state);

render/pass.c

@@ -18,8 +18,8 @@ void wlr_render_pass_add_texture(struct wlr_render_pass *render_pass,
 		const struct wlr_render_texture_options *options) {
 	// make sure the texture source box does not try and sample outside of the
 	// texture
-	if (!wlr_fbox_empty(&options->src_box)) {
-		const struct wlr_fbox *box = &options->src_box;
+	const struct wlr_fbox *box = &options->src_box;
+	if (!wlr_fbox_empty(box)) {
 		assert(box->x >= 0 && box->y >= 0 &&
 			box->x + box->width <= options->texture->width &&
 			box->y + box->height <= options->texture->height);

types/output/render.c

@@ -152,8 +152,7 @@ bool output_pick_format(struct wlr_output *output,
 		const struct wlr_drm_format_set *display_formats,
 		struct wlr_drm_format *format, uint32_t fmt) {
 	struct wlr_renderer *renderer = output->renderer;
-	struct wlr_allocator *allocator = output->allocator;
-	assert(renderer != NULL && allocator != NULL);
+	assert(renderer != NULL && output->allocator != NULL);
 
 	const struct wlr_drm_format_set *render_formats =
 		wlr_renderer_get_render_formats(renderer);

types/wlr_compositor.c

@@ -935,15 +935,14 @@ void wlr_surface_unlock_cached(struct wlr_surface *surface, uint32_t seq) {
 		return;
 	}
 
-	bool found = false;
-	struct wlr_surface_state *cached;
-	wl_list_for_each(cached, &surface->cached, cached_state_link) {
-		if (cached->seq == seq) {
-			found = true;
+	struct wlr_surface_state *cached = NULL, *iter;
+	wl_list_for_each(iter, &surface->cached, cached_state_link) {
+		if (iter->seq == seq) {
+			cached = iter;
 			break;
 		}
 	}
-	assert(found);
+	assert(cached);
 
 	assert(cached->cached_state_locks > 0);
 	cached->cached_state_locks--;
@@ -1485,6 +1484,7 @@ void wlr_surface_synced_finish(struct wlr_surface_synced *synced) {
 		}
 	}
 	assert(found);
+	(void)found;
 
 	struct wlr_surface_state *cached;
 	wl_list_for_each(cached, &surface->cached, cached_state_link) {

types/wlr_output_management_v1.c

@@ -760,16 +760,15 @@ static void head_send_state(struct wlr_output_head_v1 *head,
 	}
 
 	if (state & HEAD_STATE_MODE) {
-		bool found = false;
-		struct wl_resource *mode_resource;
-		wl_resource_for_each(mode_resource, &head->mode_resources) {
-			if (wl_resource_get_client(mode_resource) == client &&
-					mode_from_resource(mode_resource) == head->state.mode) {
-				found = true;
+		struct wl_resource *mode_resource = NULL, *iter;
+		wl_resource_for_each(iter, &head->mode_resources) {
+			if (wl_resource_get_client(iter) == client &&
+					mode_from_resource(iter) == head->state.mode) {
+				mode_resource = iter;
 				break;
 			}
 		}
-		assert(found);
+		assert(mode_resource);
 
 		if (head->state.mode == NULL) {
 			// Fake a single output mode if output doesn't support modes

types/wlr_shm.c

@@ -495,10 +495,8 @@ static void handle_display_destroy(struct wl_listener *listener, void *data) {
 	free(shm);
 }
 
-struct wlr_shm *wlr_shm_create(struct wl_display *display, uint32_t version,
+static bool __attribute__((unused)) has_argb8888_and_xrgb8888(
 		const uint32_t *formats, size_t formats_len) {
-	assert(version <= SHM_VERSION);
-
 	// ARGB8888 and XRGB8888 must be supported per the wl_shm spec
 	bool has_argb8888 = false, has_xrgb8888 = false;
 	for (size_t i = 0; i < formats_len; i++) {
@@ -511,7 +509,13 @@ struct wlr_shm *wlr_shm_create(struct wl_display *display, uint32_t version,
 			break;
 		}
 	}
-	assert(has_argb8888 && has_xrgb8888);
+	return has_argb8888 && has_xrgb8888;
+}
+
+struct wlr_shm *wlr_shm_create(struct wl_display *display, uint32_t version,
+		const uint32_t *formats, size_t formats_len) {
+	assert(version <= SHM_VERSION);
+	assert(has_argb8888_and_xrgb8888(formats, formats_len));
 
 	struct wlr_shm *shm = calloc(1, sizeof(*shm));
 	if (shm == NULL) {

xwayland/selection/dnd.c

@@ -120,10 +120,8 @@ static void xwm_dnd_send_position(struct wlr_xwm *xwm, uint32_t time, int16_t x,
 }
 
 static void xwm_dnd_send_drop(struct wlr_xwm *xwm, uint32_t time) {
-	struct wlr_drag *drag = xwm->drag;
-	assert(drag != NULL);
-	struct wlr_xwayland_surface *dest = xwm->drag_focus;
-	assert(dest != NULL);
+	assert(xwm->drag != NULL);
+	assert(xwm->drag_focus != NULL);
 
 	xcb_client_message_data_t data = { 0 };
 	data.data32[0] = xwm->dnd_selection.window;
@@ -133,10 +131,8 @@ static void xwm_dnd_send_drop(struct wlr_xwm *xwm, uint32_t time) {
 }
 
 static void xwm_dnd_send_leave(struct wlr_xwm *xwm) {
-	struct wlr_drag *drag = xwm->drag;
-	assert(drag != NULL);
-	struct wlr_xwayland_surface *dest = xwm->drag_focus;
-	assert(dest != NULL);
+	assert(xwm->drag != NULL);
+	assert(xwm->drag_focus != NULL);
 
 	xcb_client_message_data_t data = { 0 };
 	data.data32[0] = xwm->dnd_selection.window;

xwayland/xwm.c

@@ -264,15 +264,14 @@ xcb_void_cookie_t xwm_send_event_with_size(xcb_connection_t *c,
 		uint8_t propagate, xcb_window_t destination,
 		uint32_t event_mask, const void *event, uint32_t length)
 {
-	if (length == 32) {
+	assert(length <= 32);
+	if (length >= 32) {
 		return xcb_send_event(c, propagate, destination, event_mask, event);
-	} else if (length < 32) {
+	} else {
 		char buf[32];
 		memcpy(buf, event, length);
 		memset(buf + length, 0, 32 - length);
 		return xcb_send_event(c, propagate, destination, event_mask, buf);
-	} else {
-		assert(false && "Event too long");
 	}
 }