--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/HotSpotDebugInfoBuilder.java	2016-12-09 00:49:17.168777606 -0800
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2013, 2015, 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.hotspot;
+
+import static jdk.vm.ci.code.BytecodeFrame.isPlaceholderBci;
+
+import org.graalvm.compiler.core.gen.DebugInfoBuilder;
+import org.graalvm.compiler.debug.GraalError;
+import org.graalvm.compiler.lir.VirtualStackSlot;
+import org.graalvm.compiler.nodes.FrameState;
+import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.spi.NodeValueMap;
+
+import jdk.vm.ci.code.BytecodeFrame;
+import jdk.vm.ci.code.StackLockValue;
+import jdk.vm.ci.code.VirtualObject;
+import jdk.vm.ci.hotspot.HotSpotCodeCacheProvider;
+import jdk.vm.ci.meta.JavaValue;
+
+/**
+ * Extends {@link DebugInfoBuilder} to allocate the extra debug information required for locks.
+ */
+public class HotSpotDebugInfoBuilder extends DebugInfoBuilder {
+
+    private final HotSpotLockStack lockStack;
+
+    private int maxInterpreterFrameSize;
+
+    private HotSpotCodeCacheProvider codeCacheProvider;
+
+    public HotSpotDebugInfoBuilder(NodeValueMap nodeValueMap, HotSpotLockStack lockStack, HotSpotLIRGenerator gen) {
+        super(nodeValueMap);
+        this.lockStack = lockStack;
+        this.codeCacheProvider = gen.getProviders().getCodeCache();
+    }
+
+    public HotSpotLockStack lockStack() {
+        return lockStack;
+    }
+
+    public int maxInterpreterFrameSize() {
+        return maxInterpreterFrameSize;
+    }
+
+    @Override
+    protected JavaValue computeLockValue(FrameState state, int lockIndex) {
+        int lockDepth = lockIndex;
+        if (state.outerFrameState() != null) {
+            lockDepth += state.outerFrameState().nestedLockDepth();
+        }
+        VirtualStackSlot slot = lockStack.makeLockSlot(lockDepth);
+        ValueNode lock = state.lockAt(lockIndex);
+        JavaValue object = toJavaValue(lock);
+        boolean eliminated = object instanceof VirtualObject || state.monitorIdAt(lockIndex) == null;
+        assert state.monitorIdAt(lockIndex) == null || state.monitorIdAt(lockIndex).getLockDepth() == lockDepth;
+        return new StackLockValue(object, slot, eliminated);
+    }
+
+    @Override
+    protected BytecodeFrame computeFrameForState(FrameState state) {
+        if (isPlaceholderBci(state.bci) && state.bci != BytecodeFrame.BEFORE_BCI) {
+            // This is really a hard error since an incorrect state could crash hotspot
+            throw GraalError.shouldNotReachHere("Invalid state " + BytecodeFrame.getPlaceholderBciName(state.bci) + " " + state);
+        }
+        BytecodeFrame result = super.computeFrameForState(state);
+        maxInterpreterFrameSize = Math.max(maxInterpreterFrameSize, codeCacheProvider.interpreterFrameSize(result));
+        return result;
+    }
+}