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
|
// Copyright 2017 The Bazel Authors. All rights reserved.
//
// 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.google.devtools.build.android.desugar;
import static org.objectweb.asm.Opcodes.ASM6;
import static org.objectweb.asm.Opcodes.INVOKESTATIC;
import static org.objectweb.asm.Opcodes.LCMP;
import com.google.devtools.build.android.desugar.io.CoreLibraryRewriter;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
/**
* This class rewrites any call to Long.compare with the JVM instruction lcmp that is semantically
* equivalent to Long.compare.
*/
public class LongCompareMethodRewriter extends ClassVisitor {
private final CoreLibraryRewriter rewriter;
public LongCompareMethodRewriter(ClassVisitor cv, CoreLibraryRewriter rewriter) {
super(ASM6, cv);
this.rewriter = rewriter;
}
@Override
public MethodVisitor visitMethod(
int access, String name, String desc, String signature, String[] exceptions) {
MethodVisitor visitor = super.cv.visitMethod(access, name, desc, signature, exceptions);
return visitor == null ? visitor : new LongCompareMethodVisitor(visitor);
}
private class LongCompareMethodVisitor extends MethodVisitor {
public LongCompareMethodVisitor(MethodVisitor visitor) {
super(ASM6, visitor);
}
@Override
public void visitMethodInsn(int opcode, String owner, String name, String desc, boolean itf) {
if (opcode == INVOKESTATIC
&& rewriter.unprefix(owner).equals("java/lang/Long")
&& name.equals("compare")
&& desc.equals("(JJ)I")) {
super.visitInsn(LCMP);
} else {
super.visitMethodInsn(opcode, owner, name, desc, itf);
}
}
}
}
|
