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
|
/*******************************************************************************
* Copyright (c) 2009, 2019 Mountainminds GmbH & Co. KG and Contributors
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Evgeny Mandrikov - initial API and implementation
*
*******************************************************************************/
package org.jacoco.core.internal.analysis.filter;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.LookupSwitchInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.TableSwitchInsnNode;
/**
* Filters code that is generated by javac for a switch statement with a String.
*/
public final class StringSwitchJavacFilter implements IFilter {
public void filter(final MethodNode methodNode,
final IFilterContext context, final IFilterOutput output) {
AbstractInsnNode i = methodNode.instructions.getFirst();
while (i != null) {
filter(i, output);
i = i.getNext();
}
}
/**
* javac generates two switches. First one by {@link String#hashCode()}.
* Number of handlers in the second switch is equal to number of handlers in
* source code, so it is enough to completely filter-out first switch.
* Handler for default case of the first switch - is the second switch.
*/
private void filter(final AbstractInsnNode start,
final IFilterOutput output) {
final LabelNode dflt;
if (start.getOpcode() == Opcodes.LOOKUPSWITCH) {
dflt = ((LookupSwitchInsnNode) start).dflt;
} else if (start.getOpcode() == Opcodes.TABLESWITCH) {
dflt = ((TableSwitchInsnNode) start).dflt;
} else {
return;
}
if (new Matcher().match(start, dflt)) {
output.ignore(start, dflt);
}
}
private static class Matcher extends AbstractMatcher {
boolean match(final AbstractInsnNode start,
final AbstractInsnNode secondSwitchLabel) {
cursor = start;
for (int i = 0; cursor != null && i < 4; i++) {
cursor = cursor.getPrevious();
}
if (cursor == null || cursor.getOpcode() != Opcodes.ICONST_M1) {
return false;
}
nextIsVar(Opcodes.ISTORE, "c");
// Even if expression is not a variable, its result will be
// precomputed before the previous two instructions:
nextIsVar(Opcodes.ALOAD, "s");
nextIsInvoke(Opcodes.INVOKEVIRTUAL, "java/lang/String", "hashCode",
"()I");
next();
while (true) {
nextIsVar(Opcodes.ALOAD, "s");
nextIs(Opcodes.LDC);
nextIsInvoke(Opcodes.INVOKEVIRTUAL, "java/lang/String",
"equals", "(Ljava/lang/Object;)Z");
// jump to next comparison or second switch
nextIs(Opcodes.IFEQ);
// ICONST, BIPUSH or SIPUSH
next();
nextIsVar(Opcodes.ISTORE, "c");
if (cursor == null) {
return false;
}
if (cursor.getNext() == secondSwitchLabel) {
break;
}
nextIs(Opcodes.GOTO);
if (((JumpInsnNode) cursor).label != secondSwitchLabel) {
return false;
}
}
nextIsVar(Opcodes.ILOAD, "c");
// Can be TABLESWITCH or LOOKUPSWITCH depending on number of cases
nextIsSwitch();
return cursor != null;
}
}
}
|
