From 5b9e705e63f09c873cd19b7e79a0b7019d13f1ac Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 29 Mar 2011 14:47:56 -0400
Subject: [PATCH] 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                        |  3 +++
 gcc/cp/pt.c                             |  5 +++++
 gcc/testsuite/ChangeLog                 |  2 ++
 gcc/testsuite/g++.dg/cpp0x/dependent1.C | 25 +++++++++++++++++++++++++
 4 files changed, 35 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/dependent1.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 3d0c02a44fa..c4df48dd746 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 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.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index dfc726a005a..aa0901be3be 100644
--- a/gcc/cp/pt.c
+++ b/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.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index fbd21e5d3a4..95157981e25 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,7 @@
 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.
diff --git a/gcc/testsuite/g++.dg/cpp0x/dependent1.C b/gcc/testsuite/g++.dg/cpp0x/dependent1.C
new file mode 100644
index 00000000000..1ceeeafd78d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/dependent1.C
@@ -0,0 +1,25 @@
+// 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;
+}
-- 
2.30.2