c++: *this folding in constexpr call

The code in cxx_eval_call_expression to fold *this was doing the wrong thing
for array decay; we can use cxx_fold_indirect_ref instead.

gcc/cp/ChangeLog:

	* constexpr.cc (cxx_fold_indirect_ref): Add default arg.
	(cxx_eval_call_expression): Call it.
	(cxx_fold_indirect_ref_1): Handle null empty_base.

diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index a015bc7c8185d3cc6dcf8ef418fe5137e0e4838e..388239ea8a8cf4fde5c225f51baaccc83fe6e0d4 100644 (file)
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -1354,6 +1354,8 @@ enum value_cat {
 
 static tree cxx_eval_constant_expression (const constexpr_ctx *, tree,
                                          value_cat, bool *, bool *, tree * = NULL);
+static tree cxx_fold_indirect_ref (const constexpr_ctx *, location_t, tree, tree,
+                                  bool * = NULL);
 
 /* Attempt to evaluate T which represents a call to a builtin function.
    We assume here that all builtin functions evaluate to scalar types
@@ -2720,9 +2722,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
         At this point it has already been evaluated in the call
         to cxx_bind_parameters_in_call.  */
       new_obj = TREE_VEC_ELT (new_call.bindings, 0);
-      STRIP_NOPS (new_obj);
-      if (TREE_CODE (new_obj) == ADDR_EXPR)
-       new_obj = TREE_OPERAND (new_obj, 0);
+      new_obj = cxx_fold_indirect_ref (ctx, loc, DECL_CONTEXT (fun), new_obj);
 
       if (ctx->call && ctx->call->fundef
          && DECL_CONSTRUCTOR_P (ctx->call->fundef->decl))
@@ -5197,7 +5197,8 @@ cxx_fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type,
          && CLASS_TYPE_P (optype)
          && DERIVED_FROM_P (type, optype))
        {
-         *empty_base = true;
+         if (empty_base)
+           *empty_base = true;
          return op;
        }
     }
@@ -5216,7 +5217,7 @@ cxx_fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type,
 
 static tree
 cxx_fold_indirect_ref (const constexpr_ctx *ctx, location_t loc, tree type,
-                      tree op0, bool *empty_base)
+                      tree op0, bool *empty_base /* = NULL*/)
 {
   tree sub = op0;
   tree subtype;