From 4b4a42c40af8376511de3b797c3d75a34f09b925 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Mon, 4 Jan 2010 12:53:29 -0500
Subject: [PATCH] re PR c++/42567 ([C++0x] ICE with auto in
 type_unification_real, at cp/pt.c:13310)

	PR c++/42567
	* semantics.c (describable_type): Remove decltype comment and
	semantics.

From-SVN: r155627
---
 gcc/cp/ChangeLog                    |  6 ++++++
 gcc/cp/semantics.c                  |  9 +++------
 gcc/testsuite/ChangeLog             |  5 +++++
 gcc/testsuite/g++.dg/cpp0x/auto17.C | 10 ++++++++++
 4 files changed, 24 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/auto17.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index af2d0c6d653..77dd1df6954 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2010-01-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42567
+	* semantics.c (describable_type): Remove decltype comment and
+	semantics.
+
 
 
 Copyright (C) 2010 Free Software Foundation, Inc.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 547e89934c1..b2f9fd31f56 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -4690,10 +4690,8 @@ finish_static_assert (tree condition, tree message, location_t location,
     }
 }
 
-/* Returns decltype((EXPR)) for cases where we can drop the decltype and
-   just return the type even though EXPR is a type-dependent expression.
-   The ABI specifies which cases this applies to, which is a subset of the
-   possible cases.  */
+/* Returns the type of EXPR for cases where we can determine it even though
+   EXPR is a type-dependent expression.  */
 
 tree
 describable_type (tree expr)
@@ -4717,8 +4715,7 @@ describable_type (tree expr)
     case PARM_DECL:
     case RESULT_DECL:
     case FUNCTION_DECL:
-      /* Named rvalue reference becomes lvalue.  */
-      type = build_reference_type (non_reference (TREE_TYPE (expr)));
+      return TREE_TYPE (expr);
       break;
 
     case NEW_EXPR:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 30b80afd82e..8d559e91c3b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-01-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42567
+	* g++.dg/cpp0x/auto17.C: New.
+
 2010-01-04  Rafael Avila de Espindola  <espindola@google.com>
 
 	* gcc.dg/lto/20100104_0.c: New.
diff --git a/gcc/testsuite/g++.dg/cpp0x/auto17.C b/gcc/testsuite/g++.dg/cpp0x/auto17.C
new file mode 100644
index 00000000000..03608d33ac6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/auto17.C
@@ -0,0 +1,10 @@
+// PR c++/42567
+// { dg-options "-std=c++0x" }
+
+template<typename B>
+struct A {
+  template<typename C>
+  void fn(C c) {
+    auto& key = *c;
+  }
+};