1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
* Copyright 2000-2013 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.intellij.debugger.jdi;
import org.jetbrains.annotations.Nullable;
/**
* "Code" attribute parsing extracted from ASM4 library and adopted to finding operations with local variables
*/
public class InstructionParser {
private final byte[] myCode;
private final long myCurrentInstructionIndex;
public InstructionParser(byte[] code, long instructionIndex) {
myCode = code;
myCurrentInstructionIndex = instructionIndex;
}
public void parse() {
final int codeEnd = myCode.length;
int v = 0;
int instructionIndex = 0;
while (v < codeEnd) {
if (instructionIndex++ >= myCurrentInstructionIndex) {
break;
}
int opcode = myCode[v] & 0xFF;
switch (Bytecodes.TYPE[opcode]) {
case Bytecodes.NOARG_INSN:
v += 1;
break;
case Bytecodes.IMPLVAR_INSN: {
final int varOpcode;
if (opcode > Bytecodes.ISTORE) {
opcode -= Bytecodes.ISTORE_0;
varOpcode = Bytecodes.ISTORE + (opcode >> 2);
}
else {
opcode -= Bytecodes.ILOAD_0;
varOpcode = Bytecodes.ILOAD + (opcode >> 2);
}
final String signature = getVarInstructionTypeSignature(varOpcode);
if (signature != null) {
localVariableInstructionFound(varOpcode, opcode & 0x3, signature);
}
v += 1;
break;
}
case Bytecodes.LABEL_INSN:
v += 3;
break;
case Bytecodes.LABELW_INSN:
v += 5;
break;
case Bytecodes.WIDE_INSN: {
opcode = myCode[v + 1] & 0xFF;
final String signature = getVarInstructionTypeSignature(opcode);
if (signature != null) {
localVariableInstructionFound(opcode, readUnsignedShort(v + 2), signature);
}
if (opcode == Bytecodes.IINC) {
v += 6;
}
else {
v += 4;
}
break;
}
case Bytecodes.TABL_INSN:
// skips 0 to 3 padding bytes
v = v + 4 - (v & 3);
// reads instruction
int min = readInt(v + 4);
int max = readInt(v + 8);
v += 12;
final int length = max - min + 1;
v += 4 * length;
break;
case Bytecodes.LOOK_INSN:
// skips 0 to 3 padding bytes
v = v + 4 - (v & 3);
// reads instruction
final int len = readInt(v + 4);
v += 8 * (len + 1);
break;
case Bytecodes.VAR_INSN: {
final String signature = getVarInstructionTypeSignature(opcode);
if (signature != null) {
localVariableInstructionFound(opcode, myCode[v + 1] & 0xFF, signature);
}
v += 2;
break;
}
case Bytecodes.SBYTE_INSN:
v += 2;
break;
case Bytecodes.SHORT_INSN:
v += 3;
break;
case Bytecodes.LDC_INSN:
v += 2;
break;
case Bytecodes.LDCW_INSN:
v += 3;
break;
case Bytecodes.FIELDORMETH_INSN:
case Bytecodes.ITFMETH_INSN: {
if (opcode == Bytecodes.INVOKEINTERFACE) {
v += 5;
}
else {
v += 3;
}
break;
}
case Bytecodes.INDYMETH_INSN: {
v += 5;
break;
}
case Bytecodes.TYPE_INSN:
v += 3;
break;
case Bytecodes.IINC_INSN: {
final String signature = getVarInstructionTypeSignature(opcode);
if (signature != null) {
localVariableInstructionFound(opcode, myCode[v + 1] & 0xFF, signature);
}
v += 3;
break;
}
// case MANA_INSN:
default:
v += 4;
break;
}
}
}
private int readUnsignedShort(final int index) {
final byte[] b = myCode;
return ((b[index] & 0xFF) << 8) | (b[index + 1] & 0xFF);
}
public int readInt(final int index) {
final byte[] b = myCode;
return ((b[index] & 0xFF) << 24) | ((b[index + 1] & 0xFF) << 16)
| ((b[index + 2] & 0xFF) << 8) | (b[index + 3] & 0xFF);
}
protected void localVariableInstructionFound(int opcode, int slot, String typeSignature) {
// override to perform actions
}
@Nullable
private static String getVarInstructionTypeSignature(int opcode) {
switch (opcode) {
case Bytecodes.ILOAD:
case Bytecodes.ILOAD_0:
case Bytecodes.ILOAD_1:
case Bytecodes.ILOAD_2:
case Bytecodes.ILOAD_3:
case Bytecodes.ISTORE:
case Bytecodes.ISTORE_0:
case Bytecodes.ISTORE_1:
case Bytecodes.ISTORE_2:
case Bytecodes.ISTORE_3:
case Bytecodes.IINC:
return "I";
case Bytecodes.LLOAD:
case Bytecodes.LLOAD_0:
case Bytecodes.LLOAD_1:
case Bytecodes.LLOAD_2:
case Bytecodes.LLOAD_3:
case Bytecodes.LSTORE:
case Bytecodes.LSTORE_0:
case Bytecodes.LSTORE_1:
case Bytecodes.LSTORE_2:
case Bytecodes.LSTORE_3:
return "J"; // long
case Bytecodes.FLOAD:
case Bytecodes.FLOAD_0:
case Bytecodes.FLOAD_1:
case Bytecodes.FLOAD_2:
case Bytecodes.FLOAD_3:
case Bytecodes.FSTORE:
case Bytecodes.FSTORE_0:
case Bytecodes.FSTORE_1:
case Bytecodes.FSTORE_2:
case Bytecodes.FSTORE_3:
return "F"; // float
case Bytecodes.DLOAD:
case Bytecodes.DLOAD_0:
case Bytecodes.DLOAD_1:
case Bytecodes.DLOAD_2:
case Bytecodes.DLOAD_3:
case Bytecodes.DSTORE:
case Bytecodes.DSTORE_0:
case Bytecodes.DSTORE_1:
case Bytecodes.DSTORE_2:
case Bytecodes.DSTORE_3:
return "D"; // double
case Bytecodes.ALOAD:
case Bytecodes.ALOAD_0:
case Bytecodes.ALOAD_1:
case Bytecodes.ALOAD_2:
case Bytecodes.ALOAD_3:
case Bytecodes.ASTORE:
case Bytecodes.ASTORE_0:
case Bytecodes.ASTORE_1:
case Bytecodes.ASTORE_2:
case Bytecodes.ASTORE_3:
return "L"; // object ref
}
return null;
}
}
|
