From 897145e3e11c868abb2b5ec23ef5f65a87914270 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 5 Nov 2010 20:02:46 +0100
Subject: [PATCH] re PR c++/46160 (ICE with volatile structure and enum)

	PR c++/46160
	* cp-gimplify.c (cp_gimplify_expr): Drop volatile MEM_REFs
	on the RHS to avoid infinite recursion with gimplify_expr.

	* g++.dg/opt/empty2.C: New test.

From-SVN: r166372
---
 gcc/cp/ChangeLog                  |  6 ++++++
 gcc/cp/cp-gimplify.c              | 10 ++++++++++
 gcc/testsuite/ChangeLog           |  3 +++
 gcc/testsuite/g++.dg/opt/empty2.C | 18 ++++++++++++++++++
 4 files changed, 37 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/opt/empty2.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e884898115c..939b05af362 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2010-11-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/46160
+	* cp-gimplify.c (cp_gimplify_expr): Drop volatile MEM_REFs
+	on the RHS to avoid infinite recursion with gimplify_expr.
+
 2010-11-05  Jason Merrill  <jason@redhat.com>
 
 	PR c++/46304
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index dd879c63b15..705979d6c55 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -595,6 +595,16 @@ cp_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 	    if (!TREE_SIDE_EFFECTS (op1)
 		|| (DECL_P (op1) && TREE_THIS_VOLATILE (op1)))
 	      *expr_p = op0;
+	    else if (TREE_CODE (op1) == MEM_REF
+		     && TREE_THIS_VOLATILE (op1))
+	      {
+		/* Similarly for volatile MEM_REFs on the RHS.  */
+		if (!TREE_SIDE_EFFECTS (TREE_OPERAND (op1, 0)))
+		  *expr_p = op0;
+		else
+		  *expr_p = build2 (COMPOUND_EXPR, TREE_TYPE (*expr_p),
+				    TREE_OPERAND (op1, 0), op0);
+	      }
 	    else
 	      *expr_p = build2 (COMPOUND_EXPR, TREE_TYPE (*expr_p),
 				op0, op1);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index debdd5467a3..203f3e0a119 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2010-11-05  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/46160
+	* g++.dg/opt/empty2.C: New test.
+
 	PR target/45670
 	* gcc.target/i386/pr45670.c: New test.
 
diff --git a/gcc/testsuite/g++.dg/opt/empty2.C b/gcc/testsuite/g++.dg/opt/empty2.C
new file mode 100644
index 00000000000..86caa5ccb0f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/empty2.C
@@ -0,0 +1,18 @@
+// PR c++/46160
+// { dg-do compile }
+
+struct S
+{
+  enum E { A };
+} s;
+volatile S t;
+
+void f (S::E);
+
+void
+g ()
+{
+  volatile S *p = &s;
+  f (p->A);
+  f (t.A);
+}