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.analysis;
60
61 import java.util.List;
62
63 import jdk.internal.org.objectweb.asm.Type;
64 import jdk.internal.org.objectweb.asm.tree.AbstractInsnNode;
65
66 /**
67 * A semantic bytecode interpreter. More precisely, this interpreter only
68 * manages the computation of values from other values: it does not manage the
69 * transfer of values to or from the stack, and to or from the local variables.
70 * This separation allows a generic bytecode {@link Analyzer} to work with
71 * various semantic interpreters, without needing to duplicate the code to
72 * simulate the transfer of values.
73 *
74 * @param <V>
75 * type of the Value used for the analysis.
76 *
77 * @author Eric Bruneton
78 */
79 public abstract class Interpreter<V extends Value> {
80
81 protected final int api;
82
83 protected Interpreter(final int api) {
84 this.api = api;
85 }
86
87 /**
88 * Creates a new value that represents the given type.
89 *
90 * Called for method parameters (including <code>this</code>), exception
91 * handler variable and with <code>null</code> type for variables reserved
92 * by long and double types.
93 *
94 * @param type
95 * a primitive or reference type, or <tt>null</tt> to represent
96 * an uninitialized value.
97 * @return a value that represents the given type. The size of the returned
98 * value must be equal to the size of the given type.
99 */
100 public abstract V newValue(Type type);
101
102 /**
103 * Interprets a bytecode instruction without arguments. This method is
104 * called for the following opcodes:
105 *
106 * ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4,
107 * ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0,
108 * DCONST_1, BIPUSH, SIPUSH, LDC, JSR, GETSTATIC, NEW
109 *
110 * @param insn
111 * the bytecode instruction to be interpreted.
112 * @return the result of the interpretation of the given instruction.
113 * @throws AnalyzerException
114 * if an error occured during the interpretation.
115 */
116 public abstract V newOperation(AbstractInsnNode insn)
117 throws AnalyzerException;
118
119 /**
120 * Interprets a bytecode instruction that moves a value on the stack or to
121 * or from local variables. This method is called for the following opcodes:
122 *
123 * ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE,
124 * ASTORE, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP
125 *
126 * @param insn
127 * the bytecode instruction to be interpreted.
128 * @param value
129 * the value that must be moved by the instruction.
130 * @return the result of the interpretation of the given instruction. The
131 * returned value must be <tt>equal</tt> to the given value.
132 * @throws AnalyzerException
133 * if an error occured during the interpretation.
134 */
135 public abstract V copyOperation(AbstractInsnNode insn, V value)
136 throws AnalyzerException;
137
138 /**
139 * Interprets a bytecode instruction with a single argument. This method is
140 * called for the following opcodes:
141 *
142 * INEG, LNEG, FNEG, DNEG, IINC, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L,
143 * F2D, D2I, D2L, D2F, I2B, I2C, I2S, IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE,
144 * TABLESWITCH, LOOKUPSWITCH, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN,
145 * PUTSTATIC, GETFIELD, NEWARRAY, ANEWARRAY, ARRAYLENGTH, ATHROW, CHECKCAST,
146 * INSTANCEOF, MONITORENTER, MONITOREXIT, IFNULL, IFNONNULL
147 *
148 * @param insn
149 * the bytecode instruction to be interpreted.
150 * @param value
151 * the argument of the instruction to be interpreted.
152 * @return the result of the interpretation of the given instruction.
153 * @throws AnalyzerException
154 * if an error occured during the interpretation.
155 */
156 public abstract V unaryOperation(AbstractInsnNode insn, V value)
157 throws AnalyzerException;
158
159 /**
160 * Interprets a bytecode instruction with two arguments. This method is
161 * called for the following opcodes:
162 *
163 * IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IADD,
164 * LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV,
165 * LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, ISHL, LSHL, ISHR, LSHR, IUSHR,
166 * LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, LCMP, FCMPL, FCMPG, DCMPL,
167 * DCMPG, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
168 * IF_ACMPEQ, IF_ACMPNE, PUTFIELD
169 *
170 * @param insn
171 * the bytecode instruction to be interpreted.
172 * @param value1
173 * the first argument of the instruction to be interpreted.
174 * @param value2
175 * the second argument of the instruction to be interpreted.
176 * @return the result of the interpretation of the given instruction.
177 * @throws AnalyzerException
178 * if an error occured during the interpretation.
179 */
180 public abstract V binaryOperation(AbstractInsnNode insn, V value1, V value2)
181 throws AnalyzerException;
182
183 /**
184 * Interprets a bytecode instruction with three arguments. This method is
185 * called for the following opcodes:
186 *
187 * IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE
188 *
189 * @param insn
190 * the bytecode instruction to be interpreted.
191 * @param value1
192 * the first argument of the instruction to be interpreted.
193 * @param value2
194 * the second argument of the instruction to be interpreted.
195 * @param value3
196 * the third argument of the instruction to be interpreted.
197 * @return the result of the interpretation of the given instruction.
198 * @throws AnalyzerException
199 * if an error occured during the interpretation.
200 */
201 public abstract V ternaryOperation(AbstractInsnNode insn, V value1,
202 V value2, V value3) throws AnalyzerException;
203
204 /**
205 * Interprets a bytecode instruction with a variable number of arguments.
206 * This method is called for the following opcodes:
207 *
208 * INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE,
209 * MULTIANEWARRAY and INVOKEDYNAMIC
210 *
211 * @param insn
212 * the bytecode instruction to be interpreted.
213 * @param values
214 * the arguments of the instruction to be interpreted.
215 * @return the result of the interpretation of the given instruction.
216 * @throws AnalyzerException
217 * if an error occured during the interpretation.
218 */
219 public abstract V naryOperation(AbstractInsnNode insn,
220 List<? extends V> values) throws AnalyzerException;
221
222 /**
223 * Interprets a bytecode return instruction. This method is called for the
224 * following opcodes:
225 *
226 * IRETURN, LRETURN, FRETURN, DRETURN, ARETURN
227 *
228 * @param insn
229 * the bytecode instruction to be interpreted.
230 * @param value
231 * the argument of the instruction to be interpreted.
232 * @param expected
233 * the expected return type of the analyzed method.
234 * @throws AnalyzerException
235 * if an error occured during the interpretation.
236 */
237 public abstract void returnOperation(AbstractInsnNode insn, V value,
238 V expected) throws AnalyzerException;
239
240 /**
241 * Merges two values. The merge operation must return a value that
242 * represents both values (for instance, if the two values are two types,
243 * the merged value must be a common super type of the two types. If the two
244 * values are integer intervals, the merged value must be an interval that
245 * contains the previous ones. Likewise for other types of values).
246 *
247 * @param v
248 * a value.
249 * @param w
250 * another value.
251 * @return the merged value. If the merged value is equal to <tt>v</tt>,
252 * this method <i>must</i> return <tt>v</tt>.
253 */
254 public abstract V merge(V v, V w);
255 }