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> type of the Value used for the analysis.
75 *
76 * @author Eric Bruneton
77 */
78 public abstract class Interpreter<V extends Value> {
79
80 protected final int api;
81
82 protected Interpreter(final int api) {
83 this.api = api;
84 }
85
86 /**
87 * Creates a new value that represents the given type.
88 *
89 * Called for method parameters (including <code>this</code>),
90 * exception handler variable and with <code>null</code> type
91 * for variables reserved by long and double types.
92 *
93 * @param type a primitive or reference type, or <tt>null</tt> to
94 * represent an uninitialized value.
95 * @return a value that represents the given type. The size of the returned
96 * value must be equal to the size of the given type.
97 */
98 public abstract V newValue(Type type);
99
100 /**
101 * Interprets a bytecode instruction without arguments. This method is
102 * called for the following opcodes:
103 *
104 * ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4,
105 * ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0,
106 * DCONST_1, BIPUSH, SIPUSH, LDC, JSR, GETSTATIC, NEW
107 *
108 * @param insn the bytecode instruction to be interpreted.
109 * @return the result of the interpretation of the given instruction.
110 * @throws AnalyzerException if an error occured during the interpretation.
111 */
112 public abstract V newOperation(AbstractInsnNode insn)
113 throws AnalyzerException;
114
115 /**
116 * Interprets a bytecode instruction that moves a value on the stack or to
117 * or from local variables. This method is called for the following opcodes:
118 *
119 * ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE,
120 * ASTORE, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP
121 *
122 * @param insn the bytecode instruction to be interpreted.
123 * @param value the value that must be moved by the instruction.
124 * @return the result of the interpretation of the given instruction. The
125 * returned value must be <tt>equal</tt> to the given value.
126 * @throws AnalyzerException if an error occured during the interpretation.
127 */
128 public abstract V copyOperation(AbstractInsnNode insn, V value)
129 throws AnalyzerException;
130
131 /**
132 * Interprets a bytecode instruction with a single argument. This method is
133 * called for the following opcodes:
134 *
135 * INEG, LNEG, FNEG, DNEG, IINC, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L,
136 * F2D, D2I, D2L, D2F, I2B, I2C, I2S, IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE,
137 * TABLESWITCH, LOOKUPSWITCH, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN,
138 * PUTSTATIC, GETFIELD, NEWARRAY, ANEWARRAY, ARRAYLENGTH, ATHROW, CHECKCAST,
139 * INSTANCEOF, MONITORENTER, MONITOREXIT, IFNULL, IFNONNULL
140 *
141 * @param insn the bytecode instruction to be interpreted.
142 * @param value the argument of the instruction to be interpreted.
143 * @return the result of the interpretation of the given instruction.
144 * @throws AnalyzerException if an error occured during the interpretation.
145 */
146 public abstract V unaryOperation(AbstractInsnNode insn, V value)
147 throws AnalyzerException;
148
149 /**
150 * Interprets a bytecode instruction with two arguments. This method is
151 * called for the following opcodes:
152 *
153 * IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IADD,
154 * LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV,
155 * LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, ISHL, LSHL, ISHR, LSHR, IUSHR,
156 * LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, LCMP, FCMPL, FCMPG, DCMPL,
157 * DCMPG, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
158 * IF_ACMPEQ, IF_ACMPNE, PUTFIELD
159 *
160 * @param insn the bytecode instruction to be interpreted.
161 * @param value1 the first argument of the instruction to be interpreted.
162 * @param value2 the second argument of the instruction to be interpreted.
163 * @return the result of the interpretation of the given instruction.
164 * @throws AnalyzerException if an error occured during the interpretation.
165 */
166 public abstract V binaryOperation(AbstractInsnNode insn, V value1, V value2)
167 throws AnalyzerException;
168
169 /**
170 * Interprets a bytecode instruction with three arguments. This method is
171 * called for the following opcodes:
172 *
173 * IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE
174 *
175 * @param insn the bytecode instruction to be interpreted.
176 * @param value1 the first argument of the instruction to be interpreted.
177 * @param value2 the second argument of the instruction to be interpreted.
178 * @param value3 the third argument of the instruction to be interpreted.
179 * @return the result of the interpretation of the given instruction.
180 * @throws AnalyzerException if an error occured during the interpretation.
181 */
182 public abstract V ternaryOperation(
183 AbstractInsnNode insn,
184 V value1,
185 V value2,
186 V value3) throws AnalyzerException;
187
188 /**
189 * Interprets a bytecode instruction with a variable number of arguments.
190 * This method is called for the following opcodes:
191 *
192 * INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE,
193 * MULTIANEWARRAY and INVOKEDYNAMIC
194 *
195 * @param insn the bytecode instruction to be interpreted.
196 * @param values the arguments of the instruction to be interpreted.
197 * @return the result of the interpretation of the given instruction.
198 * @throws AnalyzerException if an error occured during the interpretation.
199 */
200 public abstract V naryOperation(
201 AbstractInsnNode insn,
202 List< ? extends V> values) throws AnalyzerException;
203
204 /**
205 * Interprets a bytecode return instruction. This method is called for the
206 * following opcodes:
207 *
208 * IRETURN, LRETURN, FRETURN, DRETURN, ARETURN
209 *
210 * @param insn the bytecode instruction to be interpreted.
211 * @param value the argument of the instruction to be interpreted.
212 * @param expected the expected return type of the analyzed method.
213 * @throws AnalyzerException if an error occured during the interpretation.
214 */
215 public abstract void returnOperation(
216 AbstractInsnNode insn,
217 V value,
218 V expected) throws AnalyzerException;
219
220 /**
221 * Merges two values. The merge operation must return a value that
222 * represents both values (for instance, if the two values are two types,
223 * the merged value must be a common super type of the two types. If the two
224 * values are integer intervals, the merged value must be an interval that
225 * contains the previous ones. Likewise for other types of values).
226 *
227 * @param v a value.
228 * @param w another value.
229 * @return the merged value. If the merged value is equal to <tt>v</tt>,
230 * this method <i>must</i> return <tt>v</tt>.
231 */
232 public abstract V merge(V v, V w);
233 }