re PR c++/48319 ([C++0x] Segmentation fault in instantiation of std::is_constructible<int>)

	PR c++/48319
	* pt.c (value_dependent_expression_p): Handle TEMPLATE_ID_EXPR.

From-SVN: r171689

gcc/cp/ChangeLog

 2011-03-29  Jason Merrill  <jason@redhat.com>
 
+	PR c++/48319
+	* pt.c (value_dependent_expression_p): Handle TEMPLATE_ID_EXPR.
+
 	PR c++/48089
 	* semantics.c (potential_constant_expression_1): Change error about
 	use of *this in constructor into sorry.

gcc/cp/pt.c

@@ -18218,6 +18218,11 @@ value_dependent_expression_p (tree expression)
 	return false;
       }
 
+    case TEMPLATE_ID_EXPR:
+      /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
+	 type-dependent.  */
+      return type_dependent_expression_p (expression);
+
     default:
       /* A constant expression is value-dependent if any subexpression is
 	 value-dependent.  */

gcc/testsuite/ChangeLog

 2011-03-29  Jason Merrill  <jason@redhat.com>
 
+	* g++.dg/cpp0x/dependent1.C: New.
+
 	* g++.dg/cpp0x/constexpr-48089.C: Adjust.
 
 	* g++.dg/cpp0x/constexpr-memfn1.C: New.

gcc/testsuite/g++.dg/cpp0x/dependent1.C

+// PR c++/48319
+// { dg-options -std=c++0x }
+// We were failing to recognize declval<_Args1> as dependent.
+
+template<typename Tp> Tp declval() noexcept;
+
+template<typename _Tp>
+class __is_constructible_helper
+{
+  typedef char __one;
+  typedef struct { char __arr[2]; } __two;
+
+  template<typename _Tp1, typename... _Args1>
+  static decltype(_Tp1(declval<_Args1>()...), __one()) __test(int);
+
+  template<typename, typename...>
+  static __two __test(...);
+
+public:
+  static const bool __value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+int main() {
+  return __is_constructible_helper<int>::__value;
+}