defines new allocator for custom c-level objects

wee/message.c

@@ -28,7 +28,7 @@
 
 msg_t* msg_new(const char* name, list_t* arguments, msg_t* next)
 {
-    msg_t* msg = malloc(sizeof(*msg));
+    msg_t* msg = (msg_t*)obj_new_with_size(sizeof(*msg));
     memcpy(msg->name, name, strlen(name) + 1);
     msg->arguments = arguments;
     msg->next = next;

wee/object.c

@@ -30,10 +30,17 @@
 #include "hash.h"
 #include "object.h"
 
+#define DEFAULT_SLOTTABLE_SIZE 8
+
 obj_t* obj_new(void)
 {
-    obj_t* obj = malloc(sizeof(*obj));
-    obj->slots = hash_new(8);
+    return obj_new_with_size(sizeof(obj_t));
+}
+
+obj_t* obj_new_with_size(size_t size)
+{
+    obj_t* obj = malloc(size);
+    obj->slots = hash_new(DEFAULT_SLOTTABLE_SIZE);
     return obj;
 }
 

wee/object.h

@@ -36,6 +36,10 @@ typedef struct
 // Create a new empty object
 extern obj_t* obj_new(void);
 
+// Create a new empty object and allocate a given size. Use this when allocating
+// objects from custom C-level objects, like msg_t.
+extern obj_t* obj_new_with_size(size_t);
+
 // Destroy an object
 extern void obj_destroy(obj_t*);