CVS difference for ai05s/ai05-0157-1.txt

--- ai05s/ai05-0157-1.txt	2010/07/08 01:19:03	1.7
+++ ai05s/ai05-0157-1.txt	2010/10/16 03:58:11	1.8
@@ -487,3 +487,57 @@
 no problem that requires this extra sentence.
 
 ****************************************************************
+
+From: Robert Dewar
+Date: Sunday, July 11, 2010  1:52 PM
+
+unexpectedly, this turned out to be a bit of a pain.
+
+GNAT always gave a warning, but it is now required to give an error.
+
+But there are legitimate low-level mucking places where GNAT does free from
+empty storage pools, quite deliberately. There is a storage clause of zero to
+avoid any allocators, but objects are allocated under the covers, then freed
+using unchecked deallocation. I am sure I can work around this, but it is
+interesting that such an innocuous looking AI should cause quite a bit of
+trouble, and introduce significant incompatibilities. Will be interesting to see
+if any customers are affected.
+
+****************************************************************
+
+From: Robert Dewar
+Date: Sunday, July 11, 2010  2:02 PM
+
+I wonder if this incompatibility is really worth it? I am sure this was agreed
+to without any idea that it could invalidate existing code in a manner hard to
+fix.
+
+In practice giving a warning is perfectly good enough, oh well!
+
+****************************************************************
+
+From: Robert Dewar
+Date: Sunday, July 11, 2010  2:14 PM
+
+I ended up "fixing" this by simply removing the storage size clauses, so now I
+lose the compile time protection of any allocations being errors, though they
+would still generate a warning of Storage_Error in these particular cases, so
+not too bad.
+
+But odd that an AI intended to improve security at compile time ends up reducing
+security at compile time.
+
+Of course this is low level mucking, I realie, but stil interesting.
+If I can do that low level mucking, so can any other Ada user :-)
+
+****************************************************************
+
+From: Bob Duff
+Date: Sunday, July 11, 2010  2:18 PM
+
+> But there are legitimate low-level mucking places where GNAT does free
+> from empty storage pools, quite deliberately.
+
+Can you point me to some of those cases?
+
+****************************************************************