list: Return the removed item from SLIST_POP()

3 files changed, 19 insertions, 12 deletions

diff --git a/src/bftw.c b/src/bftw.c
index 6ec5cfa..966f03d 100644
--- a/src/bftw.c
+++ b/src/bftw.c
@@ -780,8 +780,7 @@ static bool bftw_pop_dir(struct bftw_state *state) {
 		return false;
 	}
 
-	state->file = state->dirs.head;
-	SLIST_POP(&state->dirs);
+	state->file = SLIST_POP(&state->dirs);
 	return true;
 }
 
@@ -952,8 +951,7 @@ static void bftw_list_sort(struct bftw_list *list) {
 
 	// Split
 	for (struct bftw_file *hare = list->head; hare && (hare = hare->next); hare = hare->next) {
-		struct bftw_file *tortoise = list->head;
-		SLIST_POP(list);
+		struct bftw_file *tortoise = SLIST_POP(list);
 		SLIST_APPEND(&left, tortoise);
 	}
 	SLIST_EXTEND(&right, list);
diff --git a/src/list.h b/src/list.h
index 87e2bf2..89f00ed 100644
--- a/src/list.h
+++ b/src/list.h
@@ -79,6 +79,7 @@
 #define BFS_LIST_H
 
 #include <stddef.h>
+#include <string.h>
 
 /**
  * Initialize a singly-linked list.
@@ -250,17 +251,27 @@
  *         A pointer to the item to remove, either &list->head or &prev->next.
  * @param node (optional)
  *         If specified, use item->node.next rather than item->next.
+ * @return
+ *         The removed item.
  */
 #define SLIST_REMOVE(list, ...) SLIST_REMOVE_(list, __VA_ARGS__, )
 
 #define SLIST_REMOVE_(list, cursor, ...) \
-	LIST_BLOCK_(SLIST_REMOVE__((list), (cursor), LIST_NEXT_(__VA_ARGS__)))
+	SLIST_REMOVE__((list), (cursor), LIST_NEXT_(__VA_ARGS__))
 
 #define SLIST_REMOVE__(list, cursor, next) \
-	void *_next = (void *)(*cursor)->next; \
-	(*cursor)->next = NULL; \
-	*cursor = _next; \
-	list->tail = _next ? list->tail : cursor;
+	(list->tail = (*cursor)->next ? list->tail : cursor, \
+	 slist_remove_impl(*cursor, cursor, &(*cursor)->next, list->tail, sizeof(*cursor)))
+
+// Helper for SLIST_REMOVE()
+static inline void *slist_remove_impl(void *ret, void *cursor, void *next, void *tail, size_t size) {
+	// ret = *cursor;
+	// *cursor = ret->next;
+	memcpy(cursor, next, size);
+	// ret->next = *list->tail; (NULL)
+	memcpy(next, tail, size);
+	return ret;
+}
 
 /**
  * Pop the head off a singly-linked list.
diff --git a/src/xspawn.c b/src/xspawn.c
index 00fb76e..740e38e 100644
--- a/src/xspawn.c
+++ b/src/xspawn.c
@@ -49,9 +49,7 @@ int bfs_spawn_init(struct bfs_spawn *ctx) {
 
 int bfs_spawn_destroy(struct bfs_spawn *ctx) {
 	while (ctx->head) {
-		struct bfs_spawn_action *action = ctx->head;
-		SLIST_POP(ctx);
-		free(action);
+		free(SLIST_POP(ctx));
 	}
 
 	return 0;