--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/VerifyUpdateUsages.java	Sat Dec 08 00:56:10 2018 -0800
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+
+package org.graalvm.compiler.core.test;
+
+import java.util.List;
+
+import org.graalvm.compiler.graph.Node;
+import org.graalvm.compiler.graph.Node.Input;
+import org.graalvm.compiler.graph.Node.OptionalInput;
+import org.graalvm.compiler.graph.NodeInputList;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.java.LoadFieldNode;
+import org.graalvm.compiler.nodes.java.MethodCallTargetNode;
+import org.graalvm.compiler.nodes.java.StoreFieldNode;
+import org.graalvm.compiler.phases.VerifyPhase;
+import org.graalvm.compiler.phases.tiers.PhaseContext;
+
+import jdk.vm.ci.meta.ResolvedJavaField;
+import jdk.vm.ci.meta.ResolvedJavaMethod;
+import jdk.vm.ci.meta.ResolvedJavaType;
+
+/**
+ * Try to ensure that methods which update {@link Input} or {@link OptionalInput} fields also
+ * include a call to {@link Node#updateUsages} or {@link Node#updateUsagesInterface}.
+ */
+public class VerifyUpdateUsages extends VerifyPhase<PhaseContext> {
+
+    @Override
+    public boolean checkContract() {
+        return false;
+    }
+
+    public VerifyUpdateUsages() {
+    }
+
+    @Override
+    protected boolean verify(StructuredGraph graph, PhaseContext context) {
+        if (graph.method().isConstructor()) {
+            return true;
+        }
+        /*
+         * There are only two acceptable patterns for methods which update Node inputs, either a
+         * single StoreField node and invoke of updateUsages or updateUsagesInterface, or 2
+         * StoreFields that come from LoadFields on the same object. Other patterns can be added as
+         * needed but it would be best to keep things simple so that verification can be simple.
+         */
+        List<StoreFieldNode> stores = graph.getNodes().filter(StoreFieldNode.class).snapshot();
+        ResolvedJavaType declaringClass = graph.method().getDeclaringClass();
+        ResolvedJavaType nodeInputList = context.getMetaAccess().lookupJavaType(NodeInputList.class);
+        StoreFieldNode storeField1 = null;
+        StoreFieldNode storeField2 = null;
+        for (StoreFieldNode store : stores) {
+            if (isNodeInput(store.field(), declaringClass, nodeInputList)) {
+                if (storeField1 == null) {
+                    storeField1 = store;
+                } else if (storeField2 == null) {
+                    storeField2 = store;
+                } else {
+                    return false;
+                }
+            }
+        }
+        if (storeField1 == null) {
+            return true;
+        }
+        if (storeField2 == null) {
+            // Single input field update so just check for updateUsages or updateUsagesInterface
+            // call
+            ResolvedJavaType node = context.getMetaAccess().lookupJavaType(Node.class);
+            for (MethodCallTargetNode call : graph.getNodes().filter(MethodCallTargetNode.class)) {
+                ResolvedJavaMethod callee = call.targetMethod();
+                if (callee.getDeclaringClass().equals(node) && (callee.getName().equals("updateUsages") || callee.getName().equals("updateUsagesInterface"))) {
+                    return true;
+                }
+            }
+        } else {
+            if (storeField1.value() instanceof LoadFieldNode && storeField2.value() instanceof LoadFieldNode) {
+                LoadFieldNode load1 = (LoadFieldNode) storeField1.value();
+                LoadFieldNode load2 = (LoadFieldNode) storeField2.value();
+                // Check for swapping values within the same object
+                if (load1.object() == storeField1.object() && load2.object() == storeField2.object() && storeField1.object() == storeField2.object() &&
+                                load1.field().equals(storeField2.field()) && load2.field().equals(storeField1.field())) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    boolean isNodeInput(ResolvedJavaField field, ResolvedJavaType declaringClass, ResolvedJavaType nodeInputList) {
+        return declaringClass.isAssignableFrom(field.getDeclaringClass()) && (field.getAnnotation(Input.class) != null || field.getAnnotation(OptionalInput.class) != null) &&
+                        !field.getType().equals(nodeInputList);
+    }
+}