re PR c++/32260 (too many warning: dereferencing type-punned pointer will break…

re PR c++/32260 (too many warning: dereferencing type-punned pointer will break strict-aliasing rules)

	PR c++/32260
	* rtti.c (enum_tinfo_kind): Fix TK_TYPE_INFO_TYPE comment.
	(typeid_ok_p): Use the same alias set for abi::__type_info_pseudo
	as for std::type_info.

	* g++.dg/rtti/typeid7.C: New test.

From-SVN: r129835

gcc/cp/ChangeLog

+2007-11-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/32260
+	* rtti.c (enum_tinfo_kind): Fix TK_TYPE_INFO_TYPE comment.
+	(typeid_ok_p): Use the same alias set for abi::__type_info_pseudo
+	as for std::type_info.
+
 2007-10-31  Paolo Carlini  <pcarlini@suse.de>
 
 	PR c++/33494

gcc/cp/rtti.c

@@ -79,7 +79,7 @@ DEF_VEC_ALLOC_O(tinfo_s,gc);
 
 typedef enum tinfo_kind
 {
-  TK_TYPE_INFO_TYPE,    /* std::type_info */
+  TK_TYPE_INFO_TYPE,    /* abi::__type_info_pseudo */
   TK_BASE_TYPE,		/* abi::__base_class_type_info */
   TK_BUILTIN_TYPE,	/* abi::__fundamental_type_info */
   TK_ARRAY_TYPE,	/* abi::__array_type_info */
@@ -264,6 +264,8 @@ get_tinfo_decl_dynamic (tree exp)
 static bool
 typeid_ok_p (void)
 {
+  tree pseudo_type_info, type_info_type;
+
   if (! flag_rtti)
     {
       error ("cannot use typeid with -fno-rtti");
@@ -276,6 +278,18 @@ typeid_ok_p (void)
       return false;
     }
 
+  pseudo_type_info
+    = VEC_index (tinfo_s, tinfo_descs, TK_TYPE_INFO_TYPE)->type;
+  type_info_type = TYPE_MAIN_VARIANT (const_type_info_type_node);
+
+  /* Make sure abi::__type_info_pseudo has the same alias set
+     as std::type_info.  */
+  if (! TYPE_ALIAS_SET_KNOWN_P (pseudo_type_info))
+    TYPE_ALIAS_SET (pseudo_type_info) = get_alias_set (type_info_type);
+  else
+    gcc_assert (TYPE_ALIAS_SET (pseudo_type_info)
+		== get_alias_set (type_info_type));
+
   return true;
 }
 

gcc/testsuite/ChangeLog

+2007-11-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/32260
+	* g++.dg/rtti/typeid7.C: New test.
+
 2007-11-01  Tom Tromey  <tromey@redhat.com>
 
 	PR preprocessor/30805:

gcc/testsuite/g++.dg/rtti/typeid7.C

+// PR c++/32260
+// { dg-do compile }
+// { dg-options "-O2 -W -Wall" }
+
+#include <typeinfo>
+
+const std::type_info &
+f1 (int i)
+{
+  return typeid (i + 1);
+}
+
+const std::type_info &
+f2 ()
+{
+  return typeid (int);
+}
+
+struct A
+{
+  A ();
+  virtual ~A ();
+  void foo ();
+};
+
+const std::type_info &
+f3 ()
+{
+  return typeid (A);
+}
+
+const std::type_info &
+f4 (A *p)
+{
+  return typeid (*p);
+}
+
+const std::type_info &
+f5 ()
+{
+  return typeid (int *);
+}
+
+const std::type_info &
+f6 ()
+{
+  return typeid (int [26][12]);
+}
+
+const std::type_info &
+f7 ()
+{
+  return typeid (int [26][12]);
+}
+
+void (A::*pmr) ();
+const std::type_info &
+f8 ()
+{
+  return typeid (pmr);
+}