1 /* 2 * Copyright (c) 2016, 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 */ 23 package jdk.vm.ci.hotspot; 24 25 /** 26 * Describes a C++ field exposed via {@link HotSpotVMConfigAccess}. 27 */ 28 public final class VMField { 29 30 /** 31 * Fully qualified name of the represented field (e.g., "Klass::_name"). 32 */ 33 public final String name; 34 35 /** 36 * The represented field's type (e.g., "Symbol*"). This may be {@code null}. 37 */ 38 public final String type; 39 40 /** 41 * If the represented field is non-static, this is its offset within the containing structure. 42 */ 43 public final long offset; 44 45 /** 46 * If the represented field is static, this is its address. Otherwise, this is 0. 47 */ 48 public final long address; 49 50 /** 51 * Value of the field represented as a boxed boolean if its C++ type is bool otherwise as a 52 * boxed long; only valid for non-oop static fields. This value is only captured once, during 53 * JVMCI initialization. If {@link #type} cannot be meaningfully (e.g., a struct) or safely 54 * (e.g., an oop) expressed as a boxed object, this is {@code null}. 55 */ 56 public final Object value; 57 58 /** 59 * Determines if the represented field is static. 60 */ 61 public boolean isStatic() { 62 return address != 0; 63 } 64 65 /** 66 * Creates a description of a non-static field. 67 */ 68 public VMField(String name, String type, long offset) { 69 this.name = name; 70 this.type = type; 71 this.offset = offset; 72 this.address = 0; 73 this.value = null; 74 } 75 76 /** 77 * Creates a description of a static field. 78 */ 79 public VMField(String name, String type, long address, Long value) { 80 this.name = name; 81 this.type = type; 82 this.offset = 0; 83 this.address = address; 84 this.value = value; 85 } 86 87 @Override 88 public String toString() { 89 String val = value == null ? "null" : String.format("0x%x", value); 90 return String.format("Field[name=%s, type=%s, offset=%d, address=0x%x, value=%s]", name, type, offset, address, val); 91 } 92 }