Uses typeof to clarify intentions of list_create

Also moves function type cast into centralized location to prevent
repetitive type cast aliasing for each and every type.

Author: koutoftimer

src/client.h

@@ -89,11 +89,6 @@ int client_check_and_send_keepalive(client_t *client, struct timeval curr_tv);
 void client_reset_keepalive(client_t *client);
 int client_timed_out(client_t *client, struct timeval curr_tv);
 
-/* Function pointers to use when making a list_t of clients */
-#define p_client_copy ((void* (*)(void *, const void *, size_t))&client_copy)
-#define p_client_cmp ((int (*)(const void *, const void *, size_t))&client_cmp)
-#define p_client_free ((void (*)(void *))&client_free)
-
 /* Inline functions as wrappers for handling the file descriptors in the
  * client's sockets */
 

src/destination.h

@@ -30,10 +30,6 @@ typedef struct destination {
         char *data;
 } destination_t;
 
-#define p_destination_copy ((void* (*)(void *, const void *, size_t))&destination_copy)
-#define p_destination_cmp ((int (*)(const void *, const void *, size_t))&destination_cmp)
-#define p_destination_free ((void (*)(void *))&destination_free)
-
 destination_t *destination_create(const char *address);
 destination_t *destination_copy(destination_t *dst, destination_t *src, size_t len);
 int destination_cmp(destination_t *c1, destination_t *c2, size_t len);

src/list.c

@@ -28,11 +28,12 @@
  * and uses the cmp, copy, and free functions. If any of the function pointers
  * are NULL, they will be set to memcmp, memcpy, or free.
  */
-list_t *list_create(int obj_sz,
-                    int (*obj_cmp)(const void *, const void *, size_t),
-                    void* (*obj_copy)(void *, const void *, size_t),
-                    void (*obj_free)(void *))
-{
+list_t *list_create_impl(
+    int obj_sz,
+    typeof(memcmp)* obj_cmp,
+    typeof(memcpy)* obj_copy,
+    typeof(free)*   obj_free
+) {
     list_t *new;
 
     new = malloc(sizeof(*new));

src/list.h

@@ -22,6 +22,9 @@
 #ifndef LIST_H
 #define LIST_H
 
+#include <stdlib.h>
+#include <string.h>
+
 #include "common.h"
 
 #define LIST_INIT_SIZE 10 /* Start off an array with 10 elements */
@@ -33,17 +36,27 @@ typedef struct list {
     int length;     /* Actual length of the pointer array */
 
     /* Function pointers to use for specific type of data types */
-    int (*obj_cmp)(const void *, const void *, size_t);
-    void* (*obj_copy)(void *, const void *, size_t);
-    void (*obj_free)(void *);
+    typeof(memcmp)* obj_cmp;
+    typeof(memcpy)* obj_copy;
+    typeof(free)*   obj_free;
 } list_t;
 
 #define LIST_LEN(l) ((l)->num_objs)
 
-list_t *list_create(int obj_sz,
-                    int (*obj_cmp)(const void *, const void *, size_t),
-                    void* (*obj_copy)(void *, const void *, size_t),
-                    void (*obj_free)(void *));
+list_t *list_create_impl(
+        int obj_sz,
+        typeof(memcmp)* obj_cmp,
+        typeof(memcpy)* obj_copy,
+        typeof(free)*   obj_free);
+
+#define list_create(obj_sz, obj_cmp, obj_copy, obj_free) \
+    list_create_impl(                                    \
+        obj_sz,                                          \
+        (typeof(memcmp)*)&obj_cmp,                       \
+        (typeof(memcpy)*)&obj_copy,                      \
+        (typeof(free)  *)&obj_free                       \
+    )
+
 void *list_add(list_t *list, void *obj);
 void *list_get(list_t *list, void *obj);
 void *list_get_at(list_t *list, int i);

src/udpclient.c

@@ -162,13 +162,13 @@ int udpclient(int argc, char* argv[])
     next_req_id = rand() % 0xffff;
 
     /* Create an empty list for the clients */
-    clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
-                          p_client_free);
+    clients = list_create(sizeof(client_t), client_cmp, client_copy,
+                          client_free);
     ERROR_GOTO(clients == NULL, "Error creating clients list.", done);
 
     /* Create and empty list for the connecting clients */
-    conn_clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
-                               p_client_free);
+    conn_clients = list_create(sizeof(client_t), client_cmp, client_copy,
+                               client_free);
     ERROR_GOTO(conn_clients == NULL, "Error creating clients list.", done);
 
     /* Create a TCP server socket to listen for incoming connections */

src/udpserver.c

@@ -149,9 +149,9 @@ int udpserver(int argc, char *argv[])
     if (argc > allowed_start)
     {
         allowed_destinations = list_create(sizeof(destination_t),
-                                           p_destination_cmp,
-                                           p_destination_copy,
-                                           p_destination_free);
+                                           destination_cmp,
+                                           destination_copy,
+                                           destination_free);
         if (!allowed_destinations)
             goto done;
         for (i = allowed_start; i < argc; i++)
@@ -166,8 +166,8 @@ int udpserver(int argc, char *argv[])
     }
 
     /* Create an empty list for the clients */
-    clients = list_create(sizeof(client_t), p_client_cmp, p_client_copy,
-                          p_client_free);
+    clients = list_create(sizeof(client_t), client_cmp, client_copy,
+                          client_free);
     if(!clients)
         goto done;