svn commit: r586811 - /incubator/stdcxx/branches/4.2.x/include/rw/_rawiter.h

[sebor]

Author: sebor
Date: Sat Oct 20 15:02:54 2007
New Revision: 586811

URL: http://svn.apache.org/viewvc?rev=586811&view=rev
Log:
2007-10-20  Martin Sebor  <[EMAIL PROTECTED]>

        STDCXX-350
        * _rawiter.h [__GNUG__ >= 4] (get_temporary_buffer,
        return_temporary_buffer): Used __attribute__ (__may_alias__) to
        tell the gcc optimizier about type-punning in a reinterpret_cast()
        and to silence gcc 4 warning: dereferencing type-punned pointer will
        break strict-aliasing rules.

Modified:
    incubator/stdcxx/branches/4.2.x/include/rw/_rawiter.h

Modified: incubator/stdcxx/branches/4.2.x/include/rw/_rawiter.h
URL: 
http://svn.apache.org/viewvc/incubator/stdcxx/branches/4.2.x/include/rw/_rawiter.h?rev=586811&r1=586810&r2=586811&view=diff
==============================================================================
--- incubator/stdcxx/branches/4.2.x/include/rw/_rawiter.h (original)
+++ incubator/stdcxx/branches/4.2.x/include/rw/_rawiter.h Sat Oct 20 15:02:54 
2007
@@ -36,7 +36,7 @@
  * implied.   See  the License  for  the  specific language  governing
  * permissions and limitations under the License.
  *
- * Copyright 1994-2006 Rogue Wave Software.
+ * Copyright 1994-2007 Rogue Wave Software, Inc.
  * 
  **************************************************************************/
 
@@ -135,8 +135,19 @@
 {
     pair<_TypeT*, _Distance> __res (0, 0);
 
+#if __GNUG__ >= 4
+
+    // tell gcc 4 about type-punning in the cast below
+    typedef void* __attribute__ ((__may_alias__)) _VoidPtrT;
+
+#else   // !gcc || gcc < 4
+
+    typedef void* _VoidPtrT;
+
+#endif   // gcc
+
     __res.second =
-        _RW::__rw_tmpbuf (_RWSTD_REINTERPRET_CAST (void**, &__res.first),
+        _RW::__rw_tmpbuf (_RWSTD_REINTERPRET_CAST (_VoidPtrT*, &__res.first),
                           __nelems < 0 ? 0 : __nelems, sizeof (_TypeT));
 
     return __res;
@@ -161,7 +172,18 @@
 inline void
 return_temporary_buffer (_TypeT *__p)
 {
-    _RW::__rw_tmpbuf (_RWSTD_REINTERPRET_CAST (void**, &__p),
+#if __GNUG__ >= 4
+
+    // tell gcc 4 about type-punning in the cast below
+    typedef void* __attribute__ ((__may_alias__)) _VoidPtrT;
+
+#else   // !gcc || gcc < 4
+
+    typedef void* _VoidPtrT;
+
+#endif   // gcc
+
+    _RW::__rw_tmpbuf (_RWSTD_REINTERPRET_CAST (_VoidPtrT*, &__p),
                       0, sizeof (_TypeT));
 }