hashmap: return NULL from destructor

We _always_ return NULL from destructors to allow direct assignments to
the variable holding the object. Especially on hashmaps, which treat NULL
as empty hashmap, this is pretty neat.

2 files changed, 31 insertions, 28 deletions

diff --git a/src/shared/hashmap.c b/src/shared/hashmap.c
index d8ea9d5aa8..c7512b222d 100644
--- a/src/shared/hashmap.c
+++ b/src/shared/hashmap.c
@@ -866,38 +866,41 @@ static void hashmap_free_no_clear(HashmapBase *h) {
                 free(h);
 }
 
-void internal_hashmap_free(HashmapBase *h) {
+HashmapBase *internal_hashmap_free(HashmapBase *h) {
 
         /* Free the hashmap, but nothing in it */
 
-        if (!h)
-                return;
+        if (h) {
+                internal_hashmap_clear(h);
+                hashmap_free_no_clear(h);
+        }
 
-        internal_hashmap_clear(h);
-        hashmap_free_no_clear(h);
+        return NULL;
 }
 
-void internal_hashmap_free_free(HashmapBase *h) {
+HashmapBase *internal_hashmap_free_free(HashmapBase *h) {
 
         /* Free the hashmap and all data objects in it, but not the
          * keys */
 
-        if (!h)
-                return;
+        if (h) {
+                internal_hashmap_clear_free(h);
+                hashmap_free_no_clear(h);
+        }
 
-        internal_hashmap_clear_free(h);
-        hashmap_free_no_clear(h);
+        return NULL;
 }
 
-void hashmap_free_free_free(Hashmap *h) {
+Hashmap *hashmap_free_free_free(Hashmap *h) {
 
         /* Free the hashmap and all data and key objects in it */
 
-        if (!h)
-                return;
+        if (h) {
+                hashmap_clear_free_free(h);
+                hashmap_free_no_clear(HASHMAP_BASE(h));
+        }
 
-        hashmap_clear_free_free(h);
-        hashmap_free_no_clear(HASHMAP_BASE(h));
+        return NULL;
 }
 
 void internal_hashmap_clear(HashmapBase *h) {
diff --git a/src/shared/hashmap.h b/src/shared/hashmap.h
index 894f67939e..a03ee5812a 100644
--- a/src/shared/hashmap.h
+++ b/src/shared/hashmap.h
@@ -144,25 +144,25 @@ OrderedHashmap *internal_ordered_hashmap_new(const struct hash_ops *hash_ops  HA
 #define hashmap_new(ops) internal_hashmap_new(ops  HASHMAP_DEBUG_SRC_ARGS)
 #define ordered_hashmap_new(ops) internal_ordered_hashmap_new(ops  HASHMAP_DEBUG_SRC_ARGS)
 
-void internal_hashmap_free(HashmapBase *h);
-static inline void hashmap_free(Hashmap *h) {
-        internal_hashmap_free(HASHMAP_BASE(h));
+HashmapBase *internal_hashmap_free(HashmapBase *h);
+static inline Hashmap *hashmap_free(Hashmap *h) {
+        return (void*)internal_hashmap_free(HASHMAP_BASE(h));
 }
-static inline void ordered_hashmap_free(OrderedHashmap *h) {
-        internal_hashmap_free(HASHMAP_BASE(h));
+static inline OrderedHashmap *ordered_hashmap_free(OrderedHashmap *h) {
+        return (void*)internal_hashmap_free(HASHMAP_BASE(h));
 }
 
-void internal_hashmap_free_free(HashmapBase *h);
-static inline void hashmap_free_free(Hashmap *h) {
-        internal_hashmap_free_free(HASHMAP_BASE(h));
+HashmapBase *internal_hashmap_free_free(HashmapBase *h);
+static inline Hashmap *hashmap_free_free(Hashmap *h) {
+        return (void*)internal_hashmap_free_free(HASHMAP_BASE(h));
 }
-static inline void ordered_hashmap_free_free(OrderedHashmap *h) {
-        internal_hashmap_free_free(HASHMAP_BASE(h));
+static inline OrderedHashmap *ordered_hashmap_free_free(OrderedHashmap *h) {
+        return (void*)internal_hashmap_free_free(HASHMAP_BASE(h));
 }
 
-void hashmap_free_free_free(Hashmap *h);
-static inline void ordered_hashmap_free_free_free(OrderedHashmap *h) {
-        hashmap_free_free_free(PLAIN_HASHMAP(h));
+Hashmap *hashmap_free_free_free(Hashmap *h);
+static inline OrderedHashmap *ordered_hashmap_free_free_free(OrderedHashmap *h) {
+        return (void*)hashmap_free_free_free(PLAIN_HASHMAP(h));
 }
 
 HashmapBase *internal_hashmap_copy(HashmapBase *h);