--- /dev/null 2015-10-08 07:25:52.000000000 -1000 +++ new/src/jdk.vm.ci/share/classes/jdk.vm.ci.meta/src/jdk/vm/ci/meta/MemoryAccessProvider.java 2015-10-08 07:25:52.000000000 -1000 @@ -0,0 +1,60 @@ +/* + * Copyright (c) 2012, 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 jdk.vm.ci.meta; + +/** + * Provides memory access operations for the target VM. + */ +public interface MemoryAccessProvider { + + /** + * Reads a value of this kind using a base address and a displacement. No bounds checking or + * type checking is performed. Returns {@code null} if the value is not available at this point. + * + * @param base the base address from which the value is read. + * @param displacement the displacement within the object in bytes + * @return the read value encapsulated in a {@link JavaConstant} object, or {@code null} if the + * value cannot be read. + */ + JavaConstant readUnsafeConstant(JavaKind kind, JavaConstant base, long displacement); + + /** + * Reads a primitive value using a base address and a displacement. + * + * @param kind the {@link JavaKind} of the returned {@link JavaConstant} object + * @param base the base address from which the value is read + * @param displacement the displacement within the object in bytes + * @param bits the number of bits to read from memory + * @return the read value encapsulated in a {@link JavaConstant} object of {@link JavaKind} kind + */ + JavaConstant readPrimitiveConstant(JavaKind kind, Constant base, long displacement, int bits); + + /** + * Reads a Java {@link Object} value using a base address and a displacement. + * + * @param base the base address from which the value is read + * @param displacement the displacement within the object in bytes + * @return the read value encapsulated in a {@link Constant} object + */ + JavaConstant readObjectConstant(Constant base, long displacement); +}