- * The _SAFE version is needed when NODE may be freed. It is not needed when
- * NODE may be removed from the hash map but its members remain accessible and
- * intact. */
-#define HMAP_FOR_EACH(NODE, STRUCT, MEMBER, HMAP) \
- for ((NODE) = CONTAINER_OF(hmap_first(HMAP), STRUCT, MEMBER); \
- &(NODE)->MEMBER != NULL; \
- (NODE) = CONTAINER_OF(hmap_next(HMAP, &(NODE)->MEMBER), \
- STRUCT, MEMBER))
-
-#define HMAP_FOR_EACH_SAFE(NODE, NEXT, STRUCT, MEMBER, HMAP) \
- for ((NODE) = CONTAINER_OF(hmap_first(HMAP), STRUCT, MEMBER); \
- (&(NODE)->MEMBER != NULL \
- ? (NEXT) = CONTAINER_OF(hmap_next(HMAP, &(NODE)->MEMBER), \
- STRUCT, MEMBER), 1 \
- : 0); \
+ * The *_INIT variants of these macros additionally evaluate the expressions
+ * supplied following the HMAP argument once during the loop initialization.
+ * This makes it possible for data structures that wrap around hmaps to insert
+ * additional initialization into their iteration macros without having to
+ * completely rewrite them. In particular, it can be a good idea to insert
+ * BUILD_ASSERT_TYPE checks for map and node types that wrap hmap, since
+ * otherwise it is possible for clients to accidentally confuse two derived
+ * data structures that happen to use the same member names for struct hmap and
+ * struct hmap_node. */
+
+/* Iterates through every node in HMAP. */
+#define HMAP_FOR_EACH(NODE, MEMBER, HMAP) \
+ HMAP_FOR_EACH_INIT(NODE, MEMBER, HMAP, (void) 0)
+#define HMAP_FOR_EACH_INIT(NODE, MEMBER, HMAP, ...) \
+ for (INIT_CONTAINER(NODE, hmap_first(HMAP), MEMBER), __VA_ARGS__; \
+ (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL); \
+ ASSIGN_CONTAINER(NODE, hmap_next(HMAP, &(NODE)->MEMBER), MEMBER))
+
+/* Safe when NODE may be freed (not needed when NODE may be removed from the
+ * hash map but its members remain accessible and intact). */
+#define HMAP_FOR_EACH_SAFE(NODE, NEXT, MEMBER, HMAP) \
+ HMAP_FOR_EACH_SAFE_INIT(NODE, NEXT, MEMBER, HMAP, (void) 0)
+#define HMAP_FOR_EACH_SAFE_INIT(NODE, NEXT, MEMBER, HMAP, ...) \
+ for (INIT_CONTAINER(NODE, hmap_first(HMAP), MEMBER), __VA_ARGS__; \
+ ((NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL) \
+ ? INIT_CONTAINER(NEXT, hmap_next(HMAP, &(NODE)->MEMBER), MEMBER), 1 \
+ : 0); \