Fix Hiredis warnings

The original Hiredis source files cause a few warnings when imported
into the Webdis code base. This commit is a combination of changes from
two previous commits that were applied to the Hiredis source files
during the last dependency upgrade.

1. From 05f168f: avoid _POSIX_C_SOURCE warnings in hiredis
2. From fc67109: Add back __UNUSED_FUNCTION__ in dict.c

src/hiredis/dict.c

@@ -40,6 +40,12 @@
 #include <limits.h>
 #include "dict.h"
 
+#ifdef __GNUC__
+#define __UNUSED_FUNCTION__ __attribute__ ((unused))
+#else
+#define __UNUSED_FUNCTION__
+#endif
+
 /* -------------------------- private prototypes ---------------------------- */
 
 static int _dictExpandIfNeeded(dict *ht);
@@ -51,6 +57,7 @@ static int _dictInit(dict *ht, dictType *type, void *privDataPtr);
 
 /* Generic hash function (a popular one from Bernstein).
  * I tested a few and this was the best. */
+__UNUSED_FUNCTION__
 static unsigned int dictGenHashFunction(const unsigned char *buf, int len) {
     unsigned int hash = 5381;
 
@@ -71,6 +78,7 @@ static void _dictReset(dict *ht) {
 }
 
 /* Create a new hash table */
+__UNUSED_FUNCTION__
 static dict *dictCreate(dictType *type, void *privDataPtr) {
     dict *ht = hi_malloc(sizeof(*ht));
     if (ht == NULL)
@@ -166,6 +174,7 @@ static int dictAdd(dict *ht, void *key, void *val) {
  * Return 1 if the key was added from scratch, 0 if there was already an
  * element with such key and dictReplace() just performed a value update
  * operation. */
+__UNUSED_FUNCTION__
 static int dictReplace(dict *ht, void *key, void *val) {
     dictEntry *entry, auxentry;
 
@@ -191,6 +200,7 @@ static int dictReplace(dict *ht, void *key, void *val) {
 }
 
 /* Search and remove an element */
+__UNUSED_FUNCTION__
 static int dictDelete(dict *ht, const void *key) {
     unsigned int h;
     dictEntry *de, *prevde;
@@ -247,6 +257,7 @@ static int _dictClear(dict *ht) {
 }
 
 /* Clear & Release the hash table */
+__UNUSED_FUNCTION__
 static void dictRelease(dict *ht) {
     _dictClear(ht);
     hi_free(ht);
@@ -267,13 +278,15 @@ static dictEntry *dictFind(dict *ht, const void *key) {
     return NULL;
 }
 
+__UNUSED_FUNCTION__
 static void dictInitIterator(dictIterator *iter, dict *ht) {
     iter->ht = ht;
     iter->index = -1;
     iter->entry = NULL;
     iter->nextEntry = NULL;
 }
 
+__UNUSED_FUNCTION__
 static dictEntry *dictNext(dictIterator *iter) {
     while (1) {
         if (iter->entry == NULL) {

src/hiredis/fmacros.h

@@ -3,8 +3,10 @@
 
 #ifndef _AIX
 #define _XOPEN_SOURCE 600
+#ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200112L
 #endif
+#endif
 
 #if defined(__APPLE__) && defined(__MACH__)
 /* Enable TCP_KEEPALIVE */