1 files changed, 82 insertions, 39 deletions

diff --git a/gcc-4.9/gcc/cp/class.c b/gcc-4.9/gcc/cp/class.c
index b46391be1..334bfd5ee 100644
--- a/gcc-4.9/gcc/cp/class.c
+++ b/gcc-4.9/gcc/cp/class.c
@@ -149,6 +149,7 @@ static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
 static void build_base_fields (record_layout_info, splay_tree, tree *);
 static void check_methods (tree);
 static void remove_zero_width_bit_fields (tree);
+static bool accessible_nvdtor_p (tree);
 static void check_bases (tree, int *, int *);
 static void check_bases_and_members (tree);
 static tree create_vtable_ptr (tree, tree *);
@@ -1384,19 +1385,21 @@ find_abi_tags_r (tree *tp, int *walk_subtrees, void *data)
 	      /* Otherwise we're diagnosing missing tags.  */
 	      else if (TYPE_P (p->subob))
 		{
-		  warning (OPT_Wabi_tag, "%qT does not have the %E abi tag "
-			   "that base %qT has", p->t, tag, p->subob);
-		  inform (location_of (p->subob), "%qT declared here",
-			  p->subob);
+		  if (warning (OPT_Wabi_tag, "%qT does not have the %E abi tag "
+			       "that base %qT has", p->t, tag, p->subob))
+		    inform (location_of (p->subob), "%qT declared here",
+			    p->subob);
 		}
 	      else
 		{
-		  warning (OPT_Wabi_tag, "%qT does not have the %E abi tag "
-			   "that %qT (used in the type of %qD) has",
-			   p->t, tag, *tp, p->subob);
-		  inform (location_of (p->subob), "%qD declared here",
-			  p->subob);
-		  inform (location_of (*tp), "%qT declared here", *tp);
+		  if (warning (OPT_Wabi_tag, "%qT does not have the %E abi tag "
+			       "that %qT (used in the type of %qD) has",
+			       p->t, tag, *tp, p->subob))
+		    {
+		      inform (location_of (p->subob), "%qD declared here",
+			      p->subob);
+		      inform (location_of (*tp), "%qT declared here", *tp);
+		    }
 		}
 	    }
 	}
@@ -1476,6 +1479,33 @@ inherit_targ_abi_tags (tree t)
   mark_type_abi_tags (t, false);
 }
 
+/* Return true, iff class T has a non-virtual destructor that is
+   accessible from outside the class heirarchy (i.e. is public, or
+   there's a suitable friend.  */
+
+static bool
+accessible_nvdtor_p (tree t)
+{
+  tree dtor = CLASSTYPE_DESTRUCTORS (t);
+
+  /* An implicitly declared destructor is always public.  And,
+     if it were virtual, we would have created it by now.  */
+  if (!dtor)
+    return true;
+
+  if (DECL_VINDEX (dtor))
+    return false; /* Virtual */
+  
+  if (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
+    return true;  /* Public */
+
+  if (CLASSTYPE_FRIEND_CLASSES (t)
+      || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
+    return true;   /* Has friends */
+
+  return false;
+}
+
 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
    and NO_CONST_ASN_REF_P.  Also set flag bits in T based on
    properties of the bases.  */
@@ -1512,13 +1542,6 @@ check_bases (tree t,
       if (!CLASSTYPE_LITERAL_P (basetype))
         CLASSTYPE_LITERAL_P (t) = false;
 
-      /* Effective C++ rule 14.  We only need to check TYPE_POLYMORPHIC_P
-	 here because the case of virtual functions but non-virtual
-	 dtor is handled in finish_struct_1.  */
-      if (!TYPE_POLYMORPHIC_P (basetype))
-	warning (OPT_Weffc__,
-		 "base class %q#T has a non-virtual destructor", basetype);
-
       /* If the base class doesn't have copy constructors or
 	 assignment operators that take const references, then the
 	 derived class cannot have such a member automatically
@@ -3062,9 +3085,9 @@ one_inherited_ctor (tree ctor, tree t)
   one_inheriting_sig (t, ctor, new_parms, i);
   if (parms == NULL_TREE)
     {
-      warning (OPT_Winherited_variadic_ctor,
-	       "the ellipsis in %qD is not inherited", ctor);
-      inform (DECL_SOURCE_LOCATION (ctor), "%qD declared here", ctor);
+      if (warning (OPT_Winherited_variadic_ctor,
+		   "the ellipsis in %qD is not inherited", ctor))
+	inform (DECL_SOURCE_LOCATION (ctor), "%qD declared here", ctor);
     }
 }
 
@@ -5547,6 +5570,30 @@ check_bases_and_members (tree t)
   TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t);
   TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
 
+  /* Warn if a public base of a polymorphic type has an accessible
+     non-virtual destructor.  It is only now that we know the class is
+     polymorphic.  Although a polymorphic base will have a already
+     been diagnosed during its definition, we warn on use too.  */
+  if (TYPE_POLYMORPHIC_P (t) && warn_nonvdtor)
+    {
+      tree binfo = TYPE_BINFO (t);
+      vec<tree, va_gc> *accesses = BINFO_BASE_ACCESSES (binfo);
+      tree base_binfo;
+      unsigned i;
+      
+      for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
+	{
+	  tree basetype = TREE_TYPE (base_binfo);
+
+	  if ((*accesses)[i] == access_public_node
+	      && (TYPE_POLYMORPHIC_P (basetype) || warn_ecpp)
+	      && accessible_nvdtor_p (basetype))
+	    warning (OPT_Wnon_virtual_dtor,
+		     "base class %q#T has accessible non-virtual destructor",
+		     basetype);
+	}
+    }
+  
   /* If the class has no user-declared constructor, but does have
      non-static const or reference data members that can never be
      initialized, issue a warning.  */
@@ -6597,25 +6644,11 @@ finish_struct_1 (tree t)
 
   /* This warning does not make sense for Java classes, since they
      cannot have destructors.  */
-  if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
-    {
-      tree dtor;
-
-      dtor = CLASSTYPE_DESTRUCTORS (t);
-      if (/* An implicitly declared destructor is always public.  And,
-	     if it were virtual, we would have created it by now.  */
-	  !dtor
-	  || (!DECL_VINDEX (dtor)
-	      && (/* public non-virtual */
-		  (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
-		   || (/* non-public non-virtual with friends */
-		       (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor))
-			&& (CLASSTYPE_FRIEND_CLASSES (t)
-			|| DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))))
-	warning (OPT_Wnon_virtual_dtor,
-		 "%q#T has virtual functions and accessible"
-		 " non-virtual destructor", t);
-    }
+  if (!TYPE_FOR_JAVA (t) && warn_nonvdtor
+      && TYPE_POLYMORPHIC_P (t) && accessible_nvdtor_p (t))
+    warning (OPT_Wnon_virtual_dtor,
+	     "%q#T has virtual functions and accessible"
+	     " non-virtual destructor", t);
 
   complete_vars (t);
 
@@ -9017,6 +9050,16 @@ build_vtbl_initializer (tree binfo,
 	      if (!TARGET_VTABLE_USES_DESCRIPTORS)
 		init = fold_convert (vfunc_ptr_type_node,
 				     build_fold_addr_expr (fn));
+	      /* Don't refer to a virtual destructor from a constructor
+		 vtable or a vtable for an abstract class, since destroying
+		 an object under construction is undefined behavior and we
+		 don't want it to be considered a candidate for speculative
+		 devirtualization.  But do create the thunk for ABI
+		 compliance.  */
+	      if (DECL_DESTRUCTOR_P (fn_original)
+		  && (CLASSTYPE_PURE_VIRTUALS (DECL_CONTEXT (fn_original))
+		      || orig_binfo != binfo))
+		init = size_zero_node;
 	    }
 	}