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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@166372 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e884898..939b05a 100644 (file)
--- 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 dd879c6..705979d 100644 (file)
--- 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 debdd54..203f3e0 100644 (file)
--- 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 (file)
index 0000000..86caa5c
--- /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);
+}