From 37ae27ae4e35f7d2e6aa74a8495175d3dd96e6ab Mon Sep 17 00:00:00 2001
From: Richard Brooksby <rb@ravenbrook.com>
Date: Wed, 19 Sep 2012 21:12:30 +0100
Subject: [PATCH] Suppress warning about pageretstruct_zero being unused.

Copied from Perforce
 Change: 179568
 ServerID: perforce.ravenbrook.com
---
 mps/code/poolamc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/mps/code/poolamc.c b/mps/code/poolamc.c
index fc71144ab84..dfac6e54db0 100644
--- a/mps/code/poolamc.c
+++ b/mps/code/poolamc.c
@@ -943,6 +943,16 @@ static Res amcInitComm(Pool pool, RankSet rankSet, va_list arg)
   Index i;
   size_t genArraySize;
   size_t genCount;
+  
+  /* Suppress a warning about this structure not being used when there
+     are no statistics.  Note that simply making the declaration conditional
+     does not work, because we carefully reference expressions inside
+     STATISTICS to prevent such warnings on parameters and local variables.
+     It's just that clang 4.0 on Mac OS X does some sort of extra check
+     that produces a special warnings about static variables. */
+#if !defined(STATISTICS)
+  UNUSED(pageretstruct_Zero);
+#endif
 
   AVER(pool != NULL);