From: Nick Mathewson <nickm@torproject.org>
Date: Tue, 26 Jan 2010 17:08:34 +0000 (-0500)
Subject: Try to fix a warning in hash_debug_entry
X-Git-Tag: release-2.0.4-alpha~55
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=137f2c602f440327b10e68f5af4e575e23d82362;p=libevent

Try to fix a warning in hash_debug_entry

Apparently some 64-bit platforms don't like it when you say

   unsigned hash(void *p)
   {
      return (unsigned)p;
   }

even if you really honestly don't want the high bits of p.  Perhaps
they will tolerate it if I say the equivalent of

   unsigned hash(void *p)
   {
      return (unsigned) (uintptr_t) p;
   }
---

diff --git a/event.c b/event.c
index ce2d7536..19674c7b 100644
--- a/event.c
+++ b/event.c
@@ -157,10 +157,15 @@ struct event_debug_entry {
 static inline unsigned
 hash_debug_entry(const struct event_debug_entry *e)
 {
+	/* We need to do this silliness to convince compilers that we
+	 * honestly mean to cast e->ptr to an integer, and discard any
+	 * part of it that doesn't fit in an unsigned.
+	 */
+	unsigned u = (unsigned) ((ev_uintptr_t) e->ptr);
 	/* Our hashtable implementation is pretty sensitive to low bits,
 	 * and every struct event is over 64 bytes in size, so we can
-	 * just say... */
-	return ((unsigned)e->ptr) >> 6;
+	 * just say >>6. */
+	return (u >> 6);
 }
 
 static inline int