impl->destroy cleanup:

- remove trivial destroy() function
 - make sure we check impl and impl->destroy before calling
 - always call free if not implemented

backend/backend.c

@@ -32,8 +32,10 @@ bool wlr_backend_start(struct wlr_backend *backend) {
 }
 
 void wlr_backend_destroy(struct wlr_backend *backend) {
-	if (backend->impl->destroy) {
+	if (backend->impl && backend->impl->destroy) {
 		backend->impl->destroy(backend);
+	} else {
+		free(backend);
 	}
 }
 

backend/wayland/output.c

@@ -103,7 +103,7 @@ struct wlr_output *wlr_wl_output_create(struct wlr_backend *_backend) {
 
 	struct wlr_wl_backend_output *output;
 	if (!(output = calloc(sizeof(struct wlr_wl_backend_output), 1))) {
-		wlr_log(L_ERROR, "Failed to allocate wlr_output_state");
+		wlr_log(L_ERROR, "Failed to allocate wlr_wl_backend_output");
 		return NULL;
 	}
 	wlr_output_init(&output->wlr_output, &output_impl);

render/gles2/renderer.c

@@ -227,10 +227,6 @@ static bool wlr_gles2_buffer_is_drm(struct wlr_renderer *_renderer,
 			EGL_TEXTURE_FORMAT, &format);
 }
 
-static void wlr_gles2_destroy(struct wlr_renderer *renderer) {
-	free(renderer);
-}
-
 static struct wlr_renderer_impl wlr_renderer_impl = {
 	.begin = wlr_gles2_begin,
 	.end = wlr_gles2_end,
@@ -240,7 +236,6 @@ static struct wlr_renderer_impl wlr_renderer_impl = {
 	.render_ellipse = wlr_gles2_render_ellipse,
 	.formats = wlr_gles2_formats,
 	.buffer_is_drm = wlr_gles2_buffer_is_drm,
-	.destroy = wlr_gles2_destroy
 };
 
 struct wlr_renderer *wlr_gles2_renderer_init(struct wlr_backend *backend) {

render/wlr_renderer.c

@@ -8,8 +8,10 @@ void wlr_renderer_init(struct wlr_renderer *renderer,
 }
 
 void wlr_renderer_destroy(struct wlr_renderer *r) {
-	if (r && r->impl->destroy) {
+	if (r && r->impl && r->impl->destroy) {
 		r->impl->destroy(r);
+	} else {
+		free(r);
 	}
 }
 

render/wlr_texture.c

@@ -9,8 +9,10 @@ void wlr_texture_init(struct wlr_texture *texture,
 }
 
 void wlr_texture_destroy(struct wlr_texture *texture) {
-	if (texture && texture->impl->destroy) {
+	if (texture && texture->impl && texture->impl->destroy) {
 		texture->impl->destroy(texture);
+	} else {
+		free(texture);
 	}
 }
 

types/wlr_output.c

@@ -183,7 +183,7 @@ void wlr_output_destroy(struct wlr_output *output) {
 		free(mode);
 	}
 	list_free(output->modes);
-	if (output->impl->destroy) {
+	if (output->impl && output->impl->destroy) {
 		output->impl->destroy(output);
 	} else {
 		free(output);