/*

 * Copyright (c) 2016, 2019, 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.hotspot;

/**

 * Describes a C++ field exposed via {@link HotSpotVMConfigAccess}.

 */

public final class VMField {

    /**

     * Fully qualified name of the represented field (e.g., "Klass::_name").

     */

    public final String name;

    /**

     * The represented field's type (e.g., "Symbol*"). This may be {@code null}.

     */

    public final String type;

    /**

     * If the represented field is non-static, this is its offset within the containing structure.

     */

    public final long offset;

    /**

     * If the represented field is static, this is its address. Otherwise, this is 0.

     */

    public final long address;

    /**

     * Value of the field represented as a boxed boolean if its C++ type is bool otherwise as a

     * boxed long; only valid for non-oop static fields. This value is only captured once, during

     * JVMCI initialization. If {@link #type} cannot be meaningfully (e.g., a struct) or safely

     * (e.g., an oop) expressed as a boxed object, this is {@code null}.

     */

    public final Object value;

    /**

     * Determines if the represented field is static.

     */

    public boolean isStatic() {

        return address != 0;

    }

    /**

     * Creates a description of a non-static field.

     */

    @VMEntryPoint

    VMField(String name, String type, long offset, long address, Object value) {

        this.name = name;

        this.type = type;

        this.offset = offset;

        this.address = address;

        this.value = value;

    }

    @Override

    public String toString() {

        String val = value == null ? "null" : (type.contains("*") ? String.format("0x%x", value) : String.format("%s", value));

        return String.format("Field[name=%s, type=%s, offset=%d, address=0x%x, value=%s]", name, type, offset, address, val);

    }

}