re PR c++/48449 ([C++0x][SFINAE] Hard errors during value-initialization expressions)

	PR c++/48449
	* typeck2.c (build_functional_cast): Check complain consistently.
	Use build_value_init and abstract_virtuals_error_sfinae.
	(abstract_virtuals_error_sfinae): Split out.
	* cp-tree.h: Declare it.
	* init.c (build_new_1): Use it.
	(build_value_init_noctor): Handle FUNCTION_TYPE.

From-SVN: r172141

gcc/cp/ChangeLog

 2011-04-07  Jason Merrill  <jason@redhat.com>
 
+	PR c++/48449
+	* typeck2.c (build_functional_cast): Check complain consistently.
+	Use build_value_init and abstract_virtuals_error_sfinae.
+	(abstract_virtuals_error_sfinae): Split out.
+	* cp-tree.h: Declare it.
+	* init.c (build_new_1): Use it.
+	(build_value_init_noctor): Handle FUNCTION_TYPE.
+
 	* semantics.c (finish_decltype_type): Simplify handling of unknown
 	type.
 

gcc/cp/cp-tree.h

@@ -5596,6 +5596,7 @@ extern tree binfo_or_else			(tree, tree);
 extern void cxx_readonly_error			(tree, enum lvalue_use);
 extern void complete_type_check_abstract	(tree);
 extern int abstract_virtuals_error		(tree, tree);
+extern int abstract_virtuals_error_sfinae	(tree, tree, tsubst_flags_t);
 
 extern tree store_init_value			(tree, tree, int);
 extern void check_narrowing			(tree, tree);

gcc/cp/init.c

@@ -458,6 +458,12 @@ build_value_init_noctor (tree type, tsubst_flags_t complain)
       /* Build a constructor to contain the initializations.  */
       return build_constructor (type, v);
     }
+  else if (TREE_CODE (type) == FUNCTION_TYPE)
+    {
+      if (complain & tf_error)
+	error ("value-initialization of function type %qT", type);
+      return error_mark_node;
+    }
 
   return build_zero_init (type, NULL_TREE, /*static_storage_p=*/false);
 }
@@ -2030,7 +2036,7 @@ build_new_1 (VEC(tree,gc) **placement, tree type, tree nelts,
       return error_mark_node;
     }
 
-  if (abstract_virtuals_error (NULL_TREE, elt_type))
+  if (abstract_virtuals_error_sfinae (NULL_TREE, elt_type, complain))
     return error_mark_node;
 
   is_initialized = (TYPE_NEEDS_CONSTRUCTING (elt_type) || *init != NULL);

gcc/cp/typeck2.c

@@ -250,7 +250,7 @@ complete_type_check_abstract (tree type)
    occurred; zero if all was well.  */
 
 int
-abstract_virtuals_error (tree decl, tree type)
+abstract_virtuals_error_sfinae (tree decl, tree type, tsubst_flags_t complain)
 {
   VEC(tree,gc) *pure;
 
@@ -301,11 +301,14 @@ abstract_virtuals_error (tree decl, tree type)
   if (!pure)
     return 0;
 
+  if (decl && TREE_CODE (decl) == RESULT_DECL)
+    return 0;
+
+  if (!(complain & tf_error))
+    return 1;
+
   if (decl)
     {
-      if (TREE_CODE (decl) == RESULT_DECL)
-	return 0;
-
       if (TREE_CODE (decl) == VAR_DECL)
 	error ("cannot declare variable %q+D to be of abstract "
 	       "type %qT", decl, type);
@@ -354,6 +357,14 @@ abstract_virtuals_error (tree decl, tree type)
   return 1;
 }
 
+/* Wrapper for the above function in the common case of wanting errors.  */
+
+int
+abstract_virtuals_error (tree decl, tree type)
+{
+  return abstract_virtuals_error_sfinae (decl, type, tf_warning_or_error);
+}
+
 /* Print an error message for invalid use of an incomplete type.
    VALUE is the expression that was used (or 0 if that isn't known)
    and TYPE is the type that was invalid.  DIAG_KIND indicates the
@@ -1527,7 +1538,8 @@ build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
 
   if (TREE_CODE (type) == REFERENCE_TYPE && !parms)
     {
-      error ("invalid value-initialization of reference type");
+      if (complain & tf_error)
+	error ("invalid value-initialization of reference type");
       return error_mark_node;
     }
 
@@ -1542,7 +1554,7 @@ build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
   if (! MAYBE_CLASS_TYPE_P (type))
     {
       if (parms == NULL_TREE)
-	return cp_convert (type, integer_zero_node);
+	return build_value_init (type, complain);
 
       /* This must build a C cast.  */
       parms = build_x_compound_expr_from_list (parms, ELK_FUNC_CAST, complain);
@@ -1558,7 +1570,7 @@ build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
 
   if (!complete_type_or_maybe_complain (type, NULL_TREE, complain))
     return error_mark_node;
-  if (abstract_virtuals_error (NULL_TREE, type))
+  if (abstract_virtuals_error_sfinae (NULL_TREE, type, complain))
     return error_mark_node;
 
   /* [expr.type.conv]

gcc/testsuite/ChangeLog

 2011-04-07  Jason Merrill  <jason@redhat.com>
 
+	* g++.dg/cpp0x/sfinae8.C: New.
+
 	* g++.dg/cpp0x/sfinae7.C: New.
 
 	* g++.dg/cpp0x/enum9.C: New.

gcc/testsuite/g++.dg/cpp0x/sfinae8.C

+// PR c++/48449
+// { dg-options -std=c++0x }
+
+template<class T, class = decltype(T())>
+char f(int);
+
+template<class>
+char (&f(...))[2];
+
+struct A { virtual ~A() = 0; };
+
+static_assert(sizeof(f<int&>(0)) != 1, "Error");
+static_assert(sizeof(f<void()>(0)) != 1, "Error");
+static_assert(sizeof(f<A>(0)) != 1, "Error");