--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/Location.java	Tue Nov 18 16:18:45 2014 +0100
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2013, 2014, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 com.oracle.truffle.api.object;
+
+import com.oracle.truffle.api.*;
+
+/**
+ * Property location.
+ *
+ * @see Shape
+ * @see Property
+ * @see DynamicObject
+ */
+public abstract class Location implements BaseLocation {
+    protected static IncompatibleLocationException incompatibleLocation() throws IncompatibleLocationException {
+        CompilerDirectives.transferToInterpreterAndInvalidate();
+        throw new IncompatibleLocationException();
+    }
+
+    protected static FinalLocationException finalLocation() throws FinalLocationException {
+        CompilerDirectives.transferToInterpreterAndInvalidate();
+        throw new FinalLocationException();
+    }
+
+    public final Object get(DynamicObject store, Shape shape) {
+        return get(store, checkShape(store, shape));
+    }
+
+    public Object get(DynamicObject store, boolean condition) {
+        return getInternal(store);
+    }
+
+    public void set(DynamicObject store, Object value, Shape shape) throws IncompatibleLocationException, FinalLocationException {
+        setInternal(store, value);
+    }
+
+    public final void set(DynamicObject store, Object value, Shape oldShape, Shape newShape) throws IncompatibleLocationException {
+        if (canStore(value)) {
+            store.setShapeAndGrow(oldShape, newShape);
+            try {
+                setInternal(store, value);
+            } catch (IncompatibleLocationException ex) {
+                throw new IllegalStateException();
+            }
+        } else {
+            throw incompatibleLocation();
+        }
+    }
+
+    public final void set(DynamicObject store, Object value) throws IncompatibleLocationException, FinalLocationException {
+        set(store, value, null);
+    }
+
+    protected abstract Object getInternal(DynamicObject store);
+
+    /**
+     * Like {@link #set(DynamicObject, Object, Shape)}, but does not invalidate final locations. For
+     * internal use only and subject to change, use {@link DynamicObjectFactory} to create objects
+     * with predefined properties.
+     *
+     * @throws IncompatibleLocationException if value is of non-assignable type
+     */
+    protected abstract void setInternal(DynamicObject store, Object value) throws IncompatibleLocationException;
+
+    /**
+     * Returns {@code true} if the location can be set to the value.
+     *
+     * @param store the receiver object
+     * @param value the value in question
+     */
+    public boolean canSet(DynamicObject store, Object value) {
+        return canStore(value);
+    }
+
+    /**
+     * Returns {@code true} if the location is compatible with the value.
+     *
+     * The value may still be rejected if {@link #canSet(DynamicObject, Object)} returns false.
+     *
+     * @param value the value in question
+     */
+    public boolean canStore(Object value) {
+        return true;
+    }
+
+    /**
+     * Returns {@code true} if this is a final location, i.e. readonly once set.
+     */
+    public boolean isFinal() {
+        return false;
+    }
+
+    /**
+     * Returns {@code true} if this is an immutable constant location.
+     */
+    public boolean isConstant() {
+        return false;
+    }
+
+    /*
+     * Abstract to force overriding.
+     */
+    @Override
+    public abstract int hashCode();
+
+    /*
+     * Abstract to force overriding.
+     */
+    @Override
+    public abstract boolean equals(Object obj);
+
+    protected static boolean checkShape(DynamicObject store, Shape shape) {
+        return store.getShape() == shape;
+    }
+}