1/*
2 * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package jdk.vm.ci.meta;
24
25/**
26 * Provides memory access operations for the target VM.
27 */
28public interface MemoryAccessProvider {
29
30    /**
31     * Reads a primitive value using a base address and a displacement.
32     *
33     * @param kind the {@link JavaKind} of the returned {@link JavaConstant} object
34     * @param base the base address from which the value is read
35     * @param displacement the displacement within the object in bytes
36     * @param bits the number of bits to read from memory
37     * @return the read value encapsulated in a {@link JavaConstant} object of {@link JavaKind} kind
38     * @throws IllegalArgumentException if the read is out of bounds of the object or {@code kind}
39     *             is {@link JavaKind#Void} or not {@linkplain JavaKind#isPrimitive() primitive}
40     *             kind or {@code bits} is not 8, 16, 32 or 64
41     */
42    JavaConstant readPrimitiveConstant(JavaKind kind, Constant base, long displacement, int bits) throws IllegalArgumentException;
43
44    /**
45     * Reads a Java {@link Object} value using a base address and a displacement.
46     *
47     * @param base the base address from which the value is read
48     * @param displacement the displacement within the object in bytes
49     * @return the read value encapsulated in a {@link Constant} object
50     * @throws IllegalArgumentException if the address computed from {@code base} and
51     *             {@code displacement} does not denote a location holding an {@code Object} value
52     */
53    JavaConstant readObjectConstant(Constant base, long displacement);
54}
55