cp-tree.h (CPTI_BAD_CAST, [...]): New cp_tree_index values.

	* cp-tree.h (CPTI_BAD_CAST, CPTI_BAD_TYPEID, CPTI_DCAST): New
	cp_tree_index values.
	(throw_bad_cast_node, throw_bad_typeid_node, dynamic_cast_node):
	New global node #defines for them.
	* rtti.c (call_void_fn): Replace with ...
	(build_runtime_decl): ... new static function.
	(throw_bad_cast): Use throw_bad_cast_node and build_runtime_decl.
	(throw_bad_typeid): Use throw_bad_typeid_node and build_runtime_decl.
	(build_dynamic_cast_1): Always produce correctly typed result.
	Explicitly produce type_info addresses. Use dynamic_cast_node.
	* exception.cc (__throw_bad_cast): Return `void *'.
	(__throw_bad_typeid): Return `const type_info &'.

From-SVN: r31585

4 files changed, 83 insertions, 29 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c50831b..0b2cda1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,20 @@
 2000-01-24  Nathan Sidwell  <sidwell@codesourcery.com>
 
+	* cp-tree.h (CPTI_BAD_CAST, CPTI_BAD_TYPEID, CPTI_DCAST): New
+	cp_tree_index values.
+	(throw_bad_cast_node, throw_bad_typeid_node, dynamic_cast_node):
+	New global node #defines for them.
+	* rtti.c (call_void_fn): Replace with ...
+	(build_runtime_decl): ... new static function.
+	(throw_bad_cast): Use throw_bad_cast_node and build_runtime_decl.
+	(throw_bad_typeid): Use throw_bad_typeid_node and build_runtime_decl.
+	(build_dynamic_cast_1): Always produce correctly typed result.
+	Explicitly produce type_info addresses. Use dynamic_cast_node.
+	* exception.cc (__throw_bad_cast): Return `void *'.
+	(__throw_bad_typeid): Return `const type_info &'.
+
+2000-01-24  Nathan Sidwell  <sidwell@codesourcery.com>
+
 	* cp-tree.h (get_vtable_decl): Prototype new function.
 	* class.c (get_vtable_decl): New function. Broken out from ...
 	(build_vtable): ... here. Use it.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 8b2a3df..564cbe3 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -557,6 +557,9 @@ enum cp_tree_index
     CPTI_TERMINATE,
     CPTI_ATEXIT,
     CPTI_DSO_HANDLE,
+    CPTI_BAD_CAST,
+    CPTI_BAD_TYPEID,
+    CPTI_DCAST,
 
     CPTI_MAX
 };
@@ -659,6 +662,15 @@ extern tree cp_global_trees[CPTI_MAX];
 /* A pointer to `__dso_handle'.  */
 #define dso_handle_node                 cp_global_trees[CPTI_DSO_HANDLE]
 
+/* The declaration of __throw_bad_cast.  */
+#define throw_bad_cast_node             cp_global_trees[CPTI_BAD_CAST]
+
+/* The declaration of __throw_bad_typeid.  */
+#define throw_bad_typeid_node           cp_global_trees[CPTI_BAD_TYPEID]
+
+/* The declaration of the dynamic_cast runtime.  */
+#define dynamic_cast_node               cp_global_trees[CPTI_DCAST]
+
 /* The type of a destructor.  */
 #define cleanup_type                    cp_global_trees[CPTI_CLEANUP_TYPE]
 
diff --git a/gcc/cp/exception.cc b/gcc/cp/exception.cc
index efc0b1f..d00e0f2 100644
--- a/gcc/cp/exception.cc
+++ b/gcc/cp/exception.cc
@@ -317,16 +317,21 @@ __check_eh_spec (int n, const void **spec)
     }
 }
 
-extern "C" void
-__throw_bad_cast (void)
+// Helpers for rtti. Although these don't return, we give them return types so
+// that the type system is not broken.
+
+extern "C" void *
+__throw_bad_cast ()
 {
   throw std::bad_cast ();
+  return 0;
 }
 
-extern "C" void
-__throw_bad_typeid (void)
+extern "C" type_info const &
+__throw_bad_typeid ()
 {
   throw std::bad_typeid ();
+  return typeid (void);
 }
 
 /* Has the current exception been caught?  */
diff --git a/gcc/cp/rtti.c b/gcc/cp/rtti.c
index 71a54c5..2341a22 100644
--- a/gcc/cp/rtti.c
+++ b/gcc/cp/rtti.c
@@ -35,7 +35,7 @@ Boston, MA 02111-1307, USA.  */
 
 extern struct obstack permanent_obstack;
 
-static tree call_void_fn PROTO((const char *));
+static tree build_runtime_decl PROTO((const char *, tree));
 static tree build_headof_sub PROTO((tree));
 static tree build_headof PROTO((tree));
 static tree get_tinfo_var PROTO((tree));
@@ -133,20 +133,22 @@ build_headof (exp)
 		cp_convert (ptrdiff_type_node, offset));
 }
 
-/* Build a call to a generic entry point taking and returning void.  */
+/* Build a decl to a runtime entry point taking void and returning TYPE. 
+   Although the entry point may never return, making its return type
+   consistent is necessary.  */
 
 static tree
-call_void_fn (name)
+build_runtime_decl (name, type)
      const char *name;
+     tree type;
 {
   tree d = get_identifier (name);
-  tree type;
   
   if (IDENTIFIER_GLOBAL_VALUE (d))
     d = IDENTIFIER_GLOBAL_VALUE (d);
   else
     {
-      type = build_function_type (void_type_node, void_list_node);
+      type = build_function_type (type, void_list_node);
       d = build_lang_decl (FUNCTION_DECL, d, type);
       DECL_EXTERNAL (d) = 1;
       TREE_PUBLIC (d) = 1;
@@ -156,7 +158,7 @@ call_void_fn (name)
     }
 
   mark_used (d);
-  return build_call (d, void_type_node, NULL_TREE);
+  return d;
 }
 
 /* Get a bad_cast node for the program to throw...
@@ -166,13 +168,28 @@ call_void_fn (name)
 static tree
 throw_bad_cast ()
 {
-  return call_void_fn ("__throw_bad_cast");
+  if (!throw_bad_cast_node)
+    throw_bad_cast_node = build_runtime_decl
+        ("__throw_bad_cast", ptr_type_node);
+  
+  return build_call (throw_bad_cast_node,
+                     TREE_TYPE (TREE_TYPE (throw_bad_cast_node)),
+                     NULL_TREE);
 }
 
 static tree
 throw_bad_typeid ()
 {
-  return call_void_fn ("__throw_bad_typeid");
+  if (!throw_bad_typeid_node)
+    throw_bad_typeid_node = build_runtime_decl
+        ("__throw_bad_typeid",
+         build_reference_type
+          (build_qualified_type
+            (type_info_type_node, TYPE_QUAL_CONST)));
+
+  return build_call (throw_bad_typeid_node,
+                     TREE_TYPE (TREE_TYPE (throw_bad_typeid_node)),
+                     NULL_TREE);
 }
 
 /* Return a pointer to type_info function associated with the expression EXP.
@@ -624,9 +641,12 @@ build_dynamic_cast_1 (type, expr)
 	      if (TREE_CODE (old_expr) == VAR_DECL
 		  && TREE_CODE (TREE_TYPE (old_expr)) == RECORD_TYPE)
 		{
+	          tree expr = throw_bad_cast ();
 		  cp_warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
 			      old_expr, type);
-		  return throw_bad_cast ();
+	          /* Bash it to the expected type.  */
+	          TREE_TYPE (expr) = type;
+		  return expr;
 		}
 	    }
 	  /* Ditto for dynamic_cast<D*>(&b).  */
@@ -658,12 +678,11 @@ build_dynamic_cast_1 (type, expr)
 	    td1 = get_tinfo_decl_dynamic (build_indirect_ref (expr, NULL_PTR));
 	  else
 	    td1 = get_tinfo_decl_dynamic (expr);
-	  td1 = decay_conversion (td1);
 	  
 	  target_type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
 	  static_type = TYPE_MAIN_VARIANT (TREE_TYPE (exprtype));
-	  td2 = decay_conversion (get_tinfo_decl (target_type));
-	  td3 = decay_conversion (get_tinfo_decl (static_type));
+	  td2 = build_unary_op (ADDR_EXPR, get_tinfo_decl (target_type), 0);
+	  td3 = build_unary_op (ADDR_EXPR, get_tinfo_decl (static_type), 0);
 
           /* Determine how T and V are related.  */
           boff = get_dynamic_cast_base_type (static_type, target_type);
@@ -676,29 +695,32 @@ build_dynamic_cast_1 (type, expr)
 	        (NULL_TREE, td3, tree_cons
 		 (NULL_TREE, expr1, NULL_TREE))))));
 
-	  dcast_fn = get_identifier ("__dynamic_cast_2");
-	  if (IDENTIFIER_GLOBAL_VALUE (dcast_fn))
-	    dcast_fn = IDENTIFIER_GLOBAL_VALUE (dcast_fn);
-	  else
+	  dcast_fn = dynamic_cast_node;
+	  if (!dcast_fn)
 	    {
 	      tree tmp;
-
+	      tree tinfo_ptr = build_pointer_type (tinfo_decl_type);
+  	      
 	      tmp = tree_cons
-		(NULL_TREE, TREE_TYPE (td1), tree_cons
-		 (NULL_TREE, TREE_TYPE (td1), tree_cons
-	          (NULL_TREE, integer_type_node, tree_cons
-		   (NULL_TREE, ptr_type_node, tree_cons
-		    (NULL_TREE, TREE_TYPE (td1), tree_cons
-		     (NULL_TREE, ptr_type_node, void_list_node))))));
+		    (NULL_TREE, tinfo_ptr, tree_cons
+		      (NULL_TREE, tinfo_ptr, tree_cons
+	                (NULL_TREE, integer_type_node, tree_cons
+		          (NULL_TREE, ptr_type_node, tree_cons
+		            (NULL_TREE, tinfo_ptr, tree_cons
+		              (NULL_TREE, ptr_type_node, void_list_node))))));
+
 	      tmp = build_function_type (ptr_type_node, tmp);
-	      dcast_fn = build_lang_decl (FUNCTION_DECL, dcast_fn, tmp);
+	      dcast_fn = build_lang_decl (FUNCTION_DECL,
+	                                  get_identifier ("__dynamic_cast_2"),
+	                                  tmp);
 	      DECL_EXTERNAL (dcast_fn) = 1;
 	      TREE_PUBLIC (dcast_fn) = 1;
 	      DECL_ARTIFICIAL (dcast_fn) = 1;
 	      pushdecl_top_level (dcast_fn);
 	      make_function_rtl (dcast_fn);
+	      
+	      dynamic_cast_node = dcast_fn;
 	    }
-	  
 	  mark_used (dcast_fn);
           result = build_call
 	    (dcast_fn, TREE_TYPE (TREE_TYPE (dcast_fn)), elems);