+ size_t extra;
+ const size_t align = ALIGNOF(struct length);
+
+ /* Round up size, and add tailer. */
+ extra = ((size + align-1) & ~(align-1)) - size;
+ extra += sizeof(struct length);
+ return extra;
+}
+
+void *tal_alloc_(const tal_t *ctx, size_t size,
+ bool clear, bool add_length, const char *label)
+{
+ size_t req_size = size;