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 */
59 package jdk.internal.org.objectweb.asm.tree;
60
61 import java.util.ArrayList;
62 import java.util.Arrays;
63 import java.util.List;
64 import java.util.Map;
65
66 import jdk.internal.org.objectweb.asm.MethodVisitor;
67 import 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> (*) this is mandatory only for classes whose version is greater than or
78 * equal to {@link Opcodes#V1_6 V1_6}.
79 *
80 * @author Eric Bruneton
81 */
82 public class FrameNode extends AbstractInsnNode {
83
84 /**
85 * The type of this frame. Must be {@link Opcodes#F_NEW} for expanded
86 * frames, or {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND},
87 * {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or
88 * {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for compressed frames.
89 */
90 public int type;
91
92 /**
93 * The types of the local variables of this stack map frame. Elements of
94 * this list can be Integer, String or LabelNode objects (for primitive,
95 * reference and uninitialized types respectively - see
96 * {@link MethodVisitor}).
97 */
98 public List<Object> local;
99
100 /**
101 * The types of the operand stack elements of this stack map frame. Elements
102 * of this list can be Integer, String or LabelNode objects (for primitive,
103 * reference and uninitialized types respectively - see
104 * {@link MethodVisitor}).
105 */
106 public List<Object> stack;
107
108 private FrameNode() {
109 super(-1);
110 }
111
112 /**
113 * Constructs a new {@link FrameNode}.
114 *
115 * @param type the type of this frame. Must be {@link Opcodes#F_NEW} for
116 * expanded frames, or {@link Opcodes#F_FULL},
117 * {@link Opcodes#F_APPEND}, {@link Opcodes#F_CHOP},
118 * {@link Opcodes#F_SAME} or {@link Opcodes#F_APPEND},
119 * {@link Opcodes#F_SAME1} for compressed frames.
120 * @param nLocal number of local variables of this stack map frame.
121 * @param local the types of the local variables of this stack map frame.
122 * Elements of this list can be Integer, String or LabelNode objects
123 * (for primitive, reference and uninitialized types respectively -
124 * see {@link MethodVisitor}).
125 * @param nStack number of operand stack elements of this stack map frame.
126 * @param stack the types of the operand stack elements of this stack map
127 * frame. Elements of this list can be Integer, String or LabelNode
128 * objects (for primitive, reference and uninitialized types
129 * respectively - see {@link MethodVisitor}).
130 */
131 public FrameNode(
132 final int type,
133 final int nLocal,
134 final Object[] local,
135 final int nStack,
136 final Object[] stack)
137 {
138 super(-1);
139 this.type = type;
140 switch (type) {
141 case Opcodes.F_NEW:
142 case Opcodes.F_FULL:
143 this.local = asList(nLocal, local);
144 this.stack = asList(nStack, stack);
145 break;
146 case Opcodes.F_APPEND:
147 this.local = asList(nLocal, local);
148 break;
149 case Opcodes.F_CHOP:
150 this.local = Arrays.asList(new Object[nLocal]);
151 break;
152 case Opcodes.F_SAME:
153 break;
154 case Opcodes.F_SAME1:
155 this.stack = asList(1, stack);
156 break;
157 }
158 }
159
160 @Override
161 public int getType() {
162 return FRAME;
163 }
164
165 /**
166 * Makes the given visitor visit this stack map frame.
167 *
168 * @param mv a method visitor.
169 */
170 @Override
171 public void accept(final MethodVisitor mv) {
172 switch (type) {
173 case Opcodes.F_NEW:
174 case Opcodes.F_FULL:
175 mv.visitFrame(type,
176 local.size(),
177 asArray(local),
178 stack.size(),
179 asArray(stack));
180 break;
181 case Opcodes.F_APPEND:
182 mv.visitFrame(type, local.size(), asArray(local), 0, null);
183 break;
184 case Opcodes.F_CHOP:
185 mv.visitFrame(type, local.size(), null, 0, null);
186 break;
187 case Opcodes.F_SAME:
188 mv.visitFrame(type, 0, null, 0, null);
189 break;
190 case Opcodes.F_SAME1:
191 mv.visitFrame(type, 0, null, 1, asArray(stack));
192 break;
193 }
194 }
195
196 @Override
197 public AbstractInsnNode clone(final Map<LabelNode, LabelNode> labels) {
198 FrameNode clone = new FrameNode();
199 clone.type = type;
200 if (local != null) {
201 clone.local = new ArrayList<Object>();
202 for (int i = 0; i < local.size(); ++i) {
203 Object l = local.get(i);
204 if (l instanceof LabelNode) {
205 l = labels.get(l);
206 }
207 clone.local.add(l);
208 }
209 }
210 if (stack != null) {
211 clone.stack = new ArrayList<Object>();
212 for (int i = 0; i < stack.size(); ++i) {
213 Object s = stack.get(i);
214 if (s instanceof LabelNode) {
215 s = labels.get(s);
216 }
217 clone.stack.add(s);
218 }
219 }
220 return clone;
221 }
222
223 // ------------------------------------------------------------------------
224
225 private static List<Object> asList(final int n, final Object[] o) {
226 return Arrays.asList(o).subList(0, n);
227 }
228
229 private static Object[] asArray(final List<Object> l) {
230 Object[] objs = new Object[l.size()];
231 for (int i = 0; i < objs.length; ++i) {
232 Object o = l.get(i);
233 if (o instanceof LabelNode) {
234 o = ((LabelNode) o).getLabel();
235 }
236 objs[i] = o;
237 }
238 return objs;
239 }
240 }