1/* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. Oracle designates this 7 * particular file as subject to the "Classpath" exception as provided 8 * by Oracle in the LICENSE file that accompanied this code. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25/* 26 * This file is available under and governed by the GNU General Public 27 * License version 2 only, as published by the Free Software Foundation. 28 * However, the following notice accompanied the original version of this 29 * file: 30 * 31 * ASM: a very small and fast Java bytecode manipulation framework 32 * Copyright (c) 2000-2011 INRIA, France Telecom 33 * All rights reserved. 34 * 35 * Redistribution and use in source and binary forms, with or without 36 * modification, are permitted provided that the following conditions 37 * are met: 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. Neither the name of the copyright holders nor the names of its 44 * contributors may be used to endorse or promote products derived from 45 * this software without specific prior written permission. 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 48 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 50 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 51 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 52 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 53 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 54 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 55 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 56 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 57 * THE POSSIBILITY OF SUCH DAMAGE. 58 */ 59package jdk.internal.org.objectweb.asm.tree; 60 61import java.util.ArrayList; 62import java.util.Arrays; 63import java.util.List; 64import java.util.Map; 65 66import jdk.internal.org.objectweb.asm.MethodVisitor; 67import jdk.internal.org.objectweb.asm.Opcodes; 68 69/** 70 * A node that represents a stack map frame. These nodes are pseudo instruction 71 * nodes in order to be inserted in an instruction list. In fact these nodes 72 * must(*) be inserted <i>just before</i> any instruction node <b>i</b> that 73 * follows an unconditionnal branch instruction such as GOTO or THROW, that is 74 * the target of a jump instruction, or that starts an exception handler block. 75 * The stack map frame types must describe the values of the local variables and 76 * of the operand stack elements <i>just before</i> <b>i</b> is executed. <br> 77 * <br> 78 * (*) this is mandatory only for classes whose version is greater than or equal 79 * to {@link Opcodes#V1_6 V1_6}. 80 * 81 * @author Eric Bruneton 82 */ 83public class FrameNode extends AbstractInsnNode { 84 85 /** 86 * The type of this frame. Must be {@link Opcodes#F_NEW} for expanded 87 * frames, or {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND}, 88 * {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or 89 * {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for compressed frames. 90 */ 91 public int type; 92 93 /** 94 * The types of the local variables of this stack map frame. Elements of 95 * this list can be Integer, String or LabelNode objects (for primitive, 96 * reference and uninitialized types respectively - see 97 * {@link MethodVisitor}). 98 */ 99 public List<Object> local; 100 101 /** 102 * The types of the operand stack elements of this stack map frame. Elements 103 * of this list can be Integer, String or LabelNode objects (for primitive, 104 * reference and uninitialized types respectively - see 105 * {@link MethodVisitor}). 106 */ 107 public List<Object> stack; 108 109 private FrameNode() { 110 super(-1); 111 } 112 113 /** 114 * Constructs a new {@link FrameNode}. 115 * 116 * @param type 117 * the type of this frame. Must be {@link Opcodes#F_NEW} for 118 * expanded frames, or {@link Opcodes#F_FULL}, 119 * {@link Opcodes#F_APPEND}, {@link Opcodes#F_CHOP}, 120 * {@link Opcodes#F_SAME} or {@link Opcodes#F_APPEND}, 121 * {@link Opcodes#F_SAME1} for compressed frames. 122 * @param nLocal 123 * number of local variables of this stack map frame. 124 * @param local 125 * the types of the local variables of this stack map frame. 126 * Elements of this list can be Integer, String or LabelNode 127 * objects (for primitive, reference and uninitialized types 128 * respectively - see {@link MethodVisitor}). 129 * @param nStack 130 * number of operand stack elements of this stack map frame. 131 * @param stack 132 * the types of the operand stack elements of this stack map 133 * frame. Elements of this list can be Integer, String or 134 * LabelNode objects (for primitive, reference and uninitialized 135 * types respectively - see {@link MethodVisitor}). 136 */ 137 public FrameNode(final int type, final int nLocal, final Object[] local, 138 final int nStack, final Object[] stack) { 139 super(-1); 140 this.type = type; 141 switch (type) { 142 case Opcodes.F_NEW: 143 case Opcodes.F_FULL: 144 this.local = asList(nLocal, local); 145 this.stack = asList(nStack, stack); 146 break; 147 case Opcodes.F_APPEND: 148 this.local = asList(nLocal, local); 149 break; 150 case Opcodes.F_CHOP: 151 this.local = Arrays.asList(new Object[nLocal]); 152 break; 153 case Opcodes.F_SAME: 154 break; 155 case Opcodes.F_SAME1: 156 this.stack = asList(1, stack); 157 break; 158 } 159 } 160 161 @Override 162 public int getType() { 163 return FRAME; 164 } 165 166 /** 167 * Makes the given visitor visit this stack map frame. 168 * 169 * @param mv 170 * a method visitor. 171 */ 172 @Override 173 public void accept(final MethodVisitor mv) { 174 switch (type) { 175 case Opcodes.F_NEW: 176 case Opcodes.F_FULL: 177 mv.visitFrame(type, local.size(), asArray(local), stack.size(), 178 asArray(stack)); 179 break; 180 case Opcodes.F_APPEND: 181 mv.visitFrame(type, local.size(), asArray(local), 0, null); 182 break; 183 case Opcodes.F_CHOP: 184 mv.visitFrame(type, local.size(), null, 0, null); 185 break; 186 case Opcodes.F_SAME: 187 mv.visitFrame(type, 0, null, 0, null); 188 break; 189 case Opcodes.F_SAME1: 190 mv.visitFrame(type, 0, null, 1, asArray(stack)); 191 break; 192 } 193 } 194 195 @Override 196 public AbstractInsnNode clone(final Map<LabelNode, LabelNode> labels) { 197 FrameNode clone = new FrameNode(); 198 clone.type = type; 199 if (local != null) { 200 clone.local = new ArrayList<Object>(); 201 for (int i = 0; i < local.size(); ++i) { 202 Object l = local.get(i); 203 if (l instanceof LabelNode) { 204 l = labels.get(l); 205 } 206 clone.local.add(l); 207 } 208 } 209 if (stack != null) { 210 clone.stack = new ArrayList<Object>(); 211 for (int i = 0; i < stack.size(); ++i) { 212 Object s = stack.get(i); 213 if (s instanceof LabelNode) { 214 s = labels.get(s); 215 } 216 clone.stack.add(s); 217 } 218 } 219 return clone; 220 } 221 222 // ------------------------------------------------------------------------ 223 224 private static List<Object> asList(final int n, final Object[] o) { 225 return Arrays.asList(o).subList(0, n); 226 } 227 228 private static Object[] asArray(final List<Object> l) { 229 Object[] objs = new Object[l.size()]; 230 for (int i = 0; i < objs.length; ++i) { 231 Object o = l.get(i); 232 if (o instanceof LabelNode) { 233 o = ((LabelNode) o).getLabel(); 234 } 235 objs[i] = o; 236 } 237 return objs; 238 } 239} 240