From 0ee1c847f75174bb87a54edb32f7f7cf27681300 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Thu, 8 Dec 2011 17:28:38 -0500
Subject: [PATCH] re PR c++/51318 (segfault on Eigen3)

	PR c++/51318
	* typeck.c (build_x_conditional_expr): Restrict glvalue games to C++11.

From-SVN: r182142
---
 gcc/cp/ChangeLog                      |  3 +++
 gcc/cp/typeck.c                       |  6 ++++--
 gcc/testsuite/ChangeLog               |  3 +++
 gcc/testsuite/g++.dg/template/cond8.C | 10 ++++++++++
 4 files changed, 20 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/template/cond8.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 70a93bd8df1..14e65c0f7a6 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2011-12-08  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51318
+	* typeck.c (build_x_conditional_expr): Restrict glvalue games to C++11.
+
 	PR c++/51459
 	* pt.c (tsubst_expr) [DECL_EXPR]: Handle capture proxies properly.
 	* semantics.c (insert_capture_proxy): No longer static.
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 9a5365c612c..4973d7d72ce 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -5517,8 +5517,10 @@ build_x_conditional_expr (tree ifexp, tree op1, tree op2,
     {
       tree min = build_min_non_dep (COND_EXPR, expr,
 				    orig_ifexp, orig_op1, orig_op2);
-      /* Remember that the result is an lvalue or xvalue.  */
-      if (lvalue_or_rvalue_with_address_p (expr)
+      /* In C++11, remember that the result is an lvalue or xvalue.
+         In C++98, lvalue_kind can just assume lvalue in a template.  */
+      if (cxx_dialect >= cxx0x
+	  && lvalue_or_rvalue_with_address_p (expr)
 	  && !lvalue_or_rvalue_with_address_p (min))
 	TREE_TYPE (min) = cp_build_reference_type (TREE_TYPE (min),
 						   !real_lvalue_p (expr));
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5c97305a784..9d4f286418e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2011-12-08  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51318
+	* g++.dg/template/cond8.C: New.
+
 	PR c++/51459
 	* g++.dg/cpp0x/lambda/lambda-template4.C: New.
 
diff --git a/gcc/testsuite/g++.dg/template/cond8.C b/gcc/testsuite/g++.dg/template/cond8.C
new file mode 100644
index 00000000000..a3bad7e7bed
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/cond8.C
@@ -0,0 +1,10 @@
+// PR c++/51318
+
+enum { e0, e1 };
+
+template<bool B, int = B ? e0 : e1> struct A {};
+
+template<typename T> struct B
+{
+  A<T::X> a;
+};
-- 
2.30.2