re PR c++/9165 (false "defined but not used" warnings)

	PR c++/9165
	* decl2.c (build_cleanup): Mark the object as used.

	PR c++/9165
	* g++.dg/warn/Wunused-3.C: New test.

From-SVN: r60972

gcc/cp/ChangeLog

 2003-01-06  Mark Mitchell  <mark@codesourcery.com>
 
+	PR c++/9165
+	* decl2.c (build_cleanup): Mark the object as used.
+
 	* pt.c (retrieve_local_specialization): Revert 2003-01-05 change.
 	(hash_local_specialization): New function.
 	(register_local_specialization): Revert 2003-01-05 change.

gcc/cp/decl2.c

@@ -1865,12 +1865,24 @@ import_export_tinfo (tree decl, tree type, bool is_in_library)
   DECL_INTERFACE_KNOWN (decl) = 1;
 }
 
+/* Return an expression that performs the destruction of DECL, which
+   must be a VAR_DECL whose type has a non-trivial destructor, or is
+   an array whose (innermost) elements have a non-trivial destructor.  */
+
 tree
 build_cleanup (tree decl)
 {
   tree temp;
   tree type = TREE_TYPE (decl);
 
+  /* This function should only be called for declarations that really
+     require cleanups.  */
+  my_friendly_assert (!TYPE_HAS_TRIVIAL_DESTRUCTOR (type), 20030106);
+
+  /* Treat all objects with destructors as used; the destructor may do
+     something substantive.  */
+  mark_used (decl);
+
   if (TREE_CODE (type) == ARRAY_TYPE)
     temp = decl;
   else

gcc/testsuite/ChangeLog

 2003-01-06  Mark Mitchell  <mark@codesourcery.com>
 
-	* testsuite/g++.dg/abi/bitfield9.C: New test.
+	PR c++/9165
+	* g++.dg/warn/Wunused-3.C: New test.
+
+	* g++.dg/abi/bitfield9.C: New test.
 
 	PR c++/9189
 	* g++.dg/parse/defarg3.C: New test.

gcc/testsuite/g++.dg/warn/Wunused-3.C

+// { dg-do compile }
+// { dg-options "-Wunused -O" }
+
+void do_cleanups();
+
+class Cleanup {
+public:
+    ~Cleanup() { do_cleanups();}
+};
+
+static Cleanup dummy;