1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.mkstubs.stubber;
18
19import org.objectweb.asm.AnnotationVisitor;
20import org.objectweb.asm.Attribute;
21import org.objectweb.asm.Label;
22import org.objectweb.asm.MethodVisitor;
23import org.objectweb.asm.Opcodes;
24
25/**
26 * A method visitor that generates a code stub for the visited method.
27 * <p/>
28 * Annotations and parameters are passed as-is.
29 * All other code is replaced by the following:
30 * <pre>throw new RuntimeException("stub");</pre>
31 * Note that constructors rewritten this way will probably fail with the runtime bytecode
32 * verifier since no call to <code>super</code> is generated.
33 */
34public class MethodStubber extends MethodVisitor {
35
36    public MethodStubber(MethodVisitor mw,
37            int access, String name, String desc, String signature, String[] exceptions) {
38        super(Opcodes.ASM4, mw);
39    }
40
41    @Override
42    public void visitCode() {
43        Label l0 = new Label();
44        mv.visitLabel(l0);
45        mv.visitLineNumber(36, l0);
46        mv.visitTypeInsn(Opcodes.NEW, "java/lang/RuntimeException");
47        mv.visitInsn(Opcodes.DUP);
48        mv.visitLdcInsn("stub");
49        mv.visitMethodInsn(
50                Opcodes.INVOKESPECIAL,          // opcode
51                "java/lang/RuntimeException",   // owner
52                "<init>",                       // name
53                "(Ljava/lang/String;)V");       // desc
54        mv.visitInsn(Opcodes.ATHROW);
55        Label l1 = new Label();
56        mv.visitLabel(l1);
57        mv.visitLocalVariable(
58                "this",                                         // name
59                "Lcom/android/mkstubs/stubber/MethodStubber;",  // desc
60                null,                                           // signature
61                l0,                                             // label start
62                l1,                                             // label end
63                0);                                             // index
64        mv.visitMaxs(3, 1); // maxStack, maxLocals
65    }
66
67    @Override
68    public void visitEnd() {
69        super.visitEnd();
70    }
71
72    @Override
73    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
74        return super.visitAnnotation(desc, visible);
75    }
76
77    @Override
78    public AnnotationVisitor visitAnnotationDefault() {
79        return super.visitAnnotationDefault();
80    }
81
82    @Override
83    public void visitAttribute(Attribute attr) {
84        super.visitAttribute(attr);
85    }
86
87    @Override
88    public AnnotationVisitor visitParameterAnnotation(int parameter, String desc, boolean visible) {
89        return super.visitParameterAnnotation(parameter, desc, visible);
90    }
91
92    // -- stuff that gets skipped
93
94    @Override
95    public void visitFieldInsn(int opcode, String owner, String name, String desc) {
96        // skip
97    }
98
99    @Override
100    public void visitFrame(int type, int local, Object[] local2, int stack, Object[] stack2) {
101        // skip
102    }
103
104    @Override
105    public void visitIincInsn(int var, int increment) {
106        // skip
107    }
108
109    @Override
110    public void visitInsn(int opcode) {
111        // skip
112    }
113
114    @Override
115    public void visitIntInsn(int opcode, int operand) {
116        // skip
117    }
118
119    @Override
120    public void visitJumpInsn(int opcode, Label label) {
121        // skip
122    }
123
124    @Override
125    public void visitLabel(Label label) {
126        // skip
127    }
128
129    @Override
130    public void visitLdcInsn(Object cst) {
131        // skip
132    }
133
134    @Override
135    public void visitLineNumber(int line, Label start) {
136        // skip
137    }
138
139    @Override
140    public void visitLocalVariable(String name, String desc, String signature,
141            Label start, Label end, int index) {
142        // skip
143    }
144
145    @Override
146    public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
147        // skip
148    }
149
150    @Override
151    public void visitMaxs(int maxStack, int maxLocals) {
152        // skip
153    }
154
155    @Override
156    public void visitMethodInsn(int opcode, String owner, String name, String desc) {
157        // skip
158    }
159
160    @Override
161    public void visitMultiANewArrayInsn(String desc, int dims) {
162        // skip
163    }
164
165    @Override
166    public void visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels) {
167        // skip
168    }
169
170    @Override
171    public void visitTryCatchBlock(Label start, Label end, Label handler, String type) {
172        // skip
173    }
174
175    @Override
176    public void visitTypeInsn(int opcode, String type) {
177        // skip
178    }
179
180    @Override
181    public void visitVarInsn(int opcode, int var) {
182        // skip
183    }
184}
185