From 356955cfb5f78224bc8c6d085d02d904ba84b4aa Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan@acm.org>
Date: Wed, 13 Oct 1999 08:49:54 +0000
Subject: [PATCH] cp-tree.h (build_x_va_arg): Prototype new function.

	* cp-tree.h (build_x_va_arg): Prototype new function.
	* call.c (build_x_va_arg): Define it.
	* parse.y (unary_expr): Call build_x_va_arg.

	* cp-tree.h (convert_type_from_ellipsis): Prototype new function.
	* call.c (convert_type_from_ellipsis): Define it.
	* decl.c (init_decl_processing): Set lang_type_promotes_to.

	* tree.c (lvalue_p_1): Accept VA_ARG_EXPR with aggregates.

From-SVN: r29942
---
 gcc/cp/ChangeLog | 12 ++++++++++++
 gcc/cp/call.c    | 42 ++++++++++++++++++++++++++++++++++++++++++
 gcc/cp/cp-tree.h |  2 ++
 gcc/cp/decl.c    |  1 +
 gcc/cp/parse.y   |  2 +-
 gcc/cp/tree.c    |  1 +
 6 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 59e0932ec1f..9bb81d02fb7 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,15 @@
+1999-10-13  Nathan Sidwell  <nathan@acm.org>
+
+	* cp-tree.h (build_x_va_arg): Prototype new function.
+	* call.c (build_x_va_arg): Define it.
+	* parse.y (unary_expr): Call build_x_va_arg.
+	
+	* cp-tree.h (convert_type_from_ellipsis): Prototype new function.
+	* call.c (convert_type_from_ellipsis): Define it.
+	* decl.c (init_decl_processing): Set lang_type_promotes_to.
+
+	* tree.c (lvalue_p_1): Accept VA_ARG_EXPR with aggregates.
+
 1999-10-11  Jason Merrill  <jason@yorick.cygnus.com>
 
 	* class.c (fixed_type_or_null): Always set *nonnull.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 6eaf61e77fe..dd4e44246f8 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -3813,6 +3813,48 @@ convert_arg_to_ellipsis (arg)
   return arg;
 }
 
+/* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused.  */
+
+tree
+build_x_va_arg (expr, type)
+     tree expr;
+     tree type;
+{
+  type = complete_type_or_else (type, NULL_TREE);
+
+  if (expr == error_mark_node || !type)
+    return error_mark_node;
+  
+  if (! pod_type_p (type))
+    {
+      /* Undefined behaviour [expr.call] 5.2.2/7.  */
+      cp_warning ("cannot receive objects of non-POD type `%#T' through `...'",
+		  type);
+    }
+  
+  return build_va_arg (expr, type);
+}
+
+/* TYPE has been given to va_arg. Apply the default conversions which would
+   have happened when passed via ellipsis. Return the promoted type, or
+   NULL_TREE, if there is no change.  */
+
+tree
+convert_type_from_ellipsis (type)
+     tree type;
+{
+  tree promote;
+  
+  if (TREE_CODE (type) == ARRAY_TYPE)
+    promote = build_pointer_type (TREE_TYPE (type));
+  else if (TREE_CODE (type) == FUNCTION_TYPE)
+    promote = build_pointer_type (type);
+  else
+    promote = type_promotes_to (type);
+  
+  return same_type_p (type, promote) ? NULL_TREE : promote;
+}
+
 /* ARG is a default argument expression being passed to a parameter of
    the indicated TYPE, which is a parameter to FN.  Do any required
    conversions.  Return the converted value.  */
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 82ed8824a8b..3246e5af875 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -3270,6 +3270,8 @@ extern int can_convert_arg			PROTO((tree, tree, tree));
 extern int enforce_access                       PROTO((tree, tree));
 extern tree convert_default_arg                 PROTO((tree, tree, tree));
 extern tree convert_arg_to_ellipsis             PROTO((tree));
+extern tree build_x_va_arg                      PROTO((tree, tree));
+extern tree convert_type_from_ellipsis          PROTO((tree));
 extern int is_properly_derived_from             PROTO((tree, tree));
 extern tree initialize_reference                PROTO((tree, tree));
 extern tree strip_top_quals                     PROTO((tree));
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1554abc6df4..60dac525eb5 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -6221,6 +6221,7 @@ init_decl_processing ()
     = build_pointer_type (build_qualified_type (void_type_node,
 						TYPE_QUAL_CONST));
   c_common_nodes_and_builtins (1, flag_no_builtin, flag_no_nonansi_builtin);
+  lang_type_promotes_to = convert_type_from_ellipsis;
 
   void_ftype_ptr
     = build_exception_variant (void_ftype_ptr, empty_except_spec);
diff --git a/gcc/cp/parse.y b/gcc/cp/parse.y
index e9d8068e388..335c022627a 100644
--- a/gcc/cp/parse.y
+++ b/gcc/cp/parse.y
@@ -1173,7 +1173,7 @@ unary_expr:
 	| IMAGPART cast_expr %prec UNARY
 		{ $$ = build_x_unary_op (IMAGPART_EXPR, $2); }
 	| VA_ARG '(' expr_no_commas ',' type_id ')'
-		{ $$ = build_va_arg ($3, groktypename ($5.t));
+		{ $$ = build_x_va_arg ($3, groktypename ($5.t));
 		  check_for_new_type ("__builtin_va_arg", $5); }
 	;
 
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index b27f9c8fc90..0b5f84365d5 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -145,6 +145,7 @@ lvalue_p_1 (ref, treat_class_rvalues_as_lvalues)
       return treat_class_rvalues_as_lvalues ? clk_class : clk_none;
 
     case CALL_EXPR:
+    case VA_ARG_EXPR:
       return ((treat_class_rvalues_as_lvalues
 	       && IS_AGGR_TYPE (TREE_TYPE (ref)))
 	      ? clk_class : clk_none);