Turn on -Wdeclaration-after-statement

Enforces code style.

alloc.c

@@ -673,10 +673,10 @@ update_layers_priority(struct liftoff_device *device)
 {
 	struct liftoff_output *output;
 	struct liftoff_layer *layer;
+	bool period_elapsed;
 
 	device->page_flip_counter++;
-	bool period_elapsed =
-		device->page_flip_counter >= LIFTOFF_PRIORITY_PERIOD;
+	period_elapsed = device->page_flip_counter >= LIFTOFF_PRIORITY_PERIOD;
 	if (period_elapsed) {
 		device->page_flip_counter = 0;
 	}

example/common.c

@@ -87,10 +87,14 @@ dumb_fb_init(struct dumb_fb *fb, int drm_fd, uint32_t format, uint32_t width,
 {
 	int ret;
 	uint32_t fb_id;
+	struct drm_mode_create_dumb create;
+	uint32_t handles[4] = {0};
+	uint32_t strides[4] = {0};
+	uint32_t offsets[4] = { 0 };
 
 	assert(format == DRM_FORMAT_ARGB8888 || format == DRM_FORMAT_XRGB8888);
 
-	struct drm_mode_create_dumb create = {
+	create = (struct drm_mode_create_dumb) {
 		.width = width,
 		.height = height,
 		.bpp = 32,
@@ -101,9 +105,8 @@ dumb_fb_init(struct dumb_fb *fb, int drm_fd, uint32_t format, uint32_t width,
 		return false;
 	}
 
-	uint32_t handles[4] = { create.handle };
-	uint32_t strides[4] = { create.pitch };
-	uint32_t offsets[4] = { 0 };
+	handles[0] = create.handle;
+	strides[0] = create.pitch;
 	ret = drmModeAddFB2(drm_fd, width, height, format, handles, strides,
 			    offsets, &fb_id, 0);
 	if (ret < 0) {

log.c

@@ -38,11 +38,12 @@ log_has(enum liftoff_log_priority priority)
 void
 liftoff_log(enum liftoff_log_priority priority, const char *fmt, ...)
 {
+	va_list args;
+
 	if (!log_has(priority)) {
 		return;
 	}
 
-	va_list args;
 	va_start(args, fmt);
 	log_handler(priority, fmt, args);
 	va_end(args);

meson.build

@@ -17,6 +17,7 @@ add_project_arguments(cc.get_supported_arguments([
 	'-Wundef',
 	'-Wmissing-prototypes',
 	'-Walloca',
+	'-Wdeclaration-after-statement',
 
 	'-Wno-missing-braces',
 	'-Wno-unused-parameter',

test/bench.c

@@ -47,6 +47,7 @@ main(int argc, char *argv[])
 	struct liftoff_layer *layers[MAX_LAYERS];
 	drmModeAtomicReq *req;
 	int ret;
+	double dur_ms;
 
 	planes_len = 5;
 	layers_len = 10;
@@ -108,8 +109,8 @@ main(int argc, char *argv[])
 
 	clock_gettime(CLOCK_MONOTONIC, &end);
 
-	double dur_ms = ((double)end.tv_sec - (double)start.tv_sec) * 1000 +
-			((double)end.tv_nsec - (double)start.tv_nsec) / 1000000;
+	dur_ms = ((double)end.tv_sec - (double)start.tv_sec) * 1000 +
+		 ((double)end.tv_nsec - (double)start.tv_nsec) / 1000000;
 	printf("Plane allocation took %fms\n", dur_ms);
 	printf("Plane allocation performed %zu atomic test commits\n",
 	       liftoff_mock_commit_count);

test/test_prop.c

@@ -50,14 +50,15 @@ test_prop_default(const char *prop_name)
 	struct liftoff_device *device;
 	struct liftoff_output *output;
 	struct liftoff_layer *layer;
+	uint64_t require_prop_value, default_value;
+	drmModePropertyRes prop = {0};
 
 	mock_plane_without_prop = liftoff_mock_drm_create_plane(DRM_PLANE_TYPE_OVERLAY);
 	mock_plane_with_prop = liftoff_mock_drm_create_plane(DRM_PLANE_TYPE_OVERLAY);
 
-	/* Value that requires the prop for the plane allocation to succeed */
-	uint64_t require_prop_value;
-	/* Value that doesn't require the prop to be present */
-	uint64_t default_value;
+	/* require_prop_value is a value that requires the prop for the plane
+	 * allocation to succeed. default_value is a value that requires the
+	 * prop for the plane allocation to succeed. */
 	if (strcmp(prop_name, "alpha") == 0) {
 		require_prop_value = (uint16_t)(0.5 * 0xFFFF);
 		default_value = 0xFFFF; /* opaque */
@@ -71,7 +72,6 @@ test_prop_default(const char *prop_name)
 
 	/* We need to setup mock plane properties before creating the liftoff
 	 * device */
-	drmModePropertyRes prop = {0};
 	strncpy(prop.name, prop_name, sizeof(prop.name) - 1);
 	liftoff_mock_plane_add_property(mock_plane_with_prop, &prop, 0);
 
@@ -473,7 +473,7 @@ test_bitmask(void)
 int
 main(int argc, char *argv[])
 {
-	const char *test_name;
+	const char *test_name, *default_test_prefix;
 
 	liftoff_log_set_priority(LIFTOFF_DEBUG);
 
@@ -483,7 +483,7 @@ main(int argc, char *argv[])
 	}
 	test_name = argv[1];
 
-	const char default_test_prefix[] = "default-";
+	default_test_prefix = "default-";
 	if (strncmp(test_name, default_test_prefix,
 	    strlen(default_test_prefix)) == 0) {
 		return test_prop_default(test_name + strlen(default_test_prefix));