1 /*
2 * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * @test
28 * @bug 8022186
29 * @summary javac generates dead code if a try with an empty body has a finalizer
30 * @modules jdk.compiler/com.sun.tools.classfile
31 * jdk.compiler/com.sun.tools.javac.util
32 */
33
34 import com.sun.tools.classfile.Attribute;
35 import com.sun.tools.classfile.ClassFile;
36 import com.sun.tools.classfile.Code_attribute;
37 import com.sun.tools.classfile.ConstantPool;
38 import com.sun.tools.classfile.ConstantPool.CONSTANT_String_info;
39 import com.sun.tools.classfile.ConstantPool.CPInfo;
40 import com.sun.tools.classfile.ConstantPool.InvalidIndex;
41 import com.sun.tools.classfile.Instruction;
42 import com.sun.tools.classfile.Instruction.KindVisitor;
43 import com.sun.tools.classfile.Instruction.TypeKind;
44 import com.sun.tools.classfile.Method;
45 import com.sun.tools.javac.util.Assert;
46 import java.io.BufferedInputStream;
47 import java.nio.file.Files;
48 import java.nio.file.Path;
49 import java.nio.file.Paths;
50
51 public class DeadCodeGeneratedForEmptyTryTest {
52
53 public static void main(String[] args) throws Exception {
54 new DeadCodeGeneratedForEmptyTryTest().run();
55 }
56
57 void run() throws Exception {
58 checkClassFile(Paths.get(System.getProperty("test.classes"),
59 this.getClass().getName() + "$Test.class"));
60 }
61
62 int utf8Index;
63 int numberOfRefToStr = 0;
64 ConstantPool constantPool;
65
66 void checkClassFile(final Path path) throws Exception {
67 ClassFile classFile = ClassFile.read(
68 new BufferedInputStream(Files.newInputStream(path)));
69 constantPool = classFile.constant_pool;
70 utf8Index = constantPool.getUTF8Index("STR_TO_LOOK_FOR");
71 for (Method method: classFile.methods) {
72 if (method.getName(constantPool).equals("methodToLookFor")) {
73 Code_attribute codeAtt = (Code_attribute)method.attributes.get(Attribute.Code);
74 for (Instruction inst: codeAtt.getInstructions()) {
75 inst.accept(codeVisitor, null);
76 }
77 }
78 }
79 Assert.check(numberOfRefToStr == 1,
80 "There should only be one reference to a CONSTANT_String_info structure in the generated code");
81 }
82
83 CodeVisitor codeVisitor = new CodeVisitor();
84
85 class CodeVisitor implements KindVisitor<Void, Void> {
86
87 void checkIndirectRefToString(int cp_index) {
88 try {
89 CPInfo cInfo = constantPool.get(cp_index);
90 if (cInfo instanceof CONSTANT_String_info) {
91 CONSTANT_String_info strInfo = (CONSTANT_String_info)cInfo;
92 if (strInfo.string_index == utf8Index) {
93 numberOfRefToStr++;
94 }
95 }
96 } catch (InvalidIndex ex) {
97 throw new AssertionError("invalid constant pool index at " + cp_index);
98 }
99 }
100
101 @Override
102 public Void visitNoOperands(Instruction instr, Void p) {
103 return null;
104 }
105
106 @Override
107 public Void visitArrayType(Instruction instr, TypeKind kind, Void p) {
108 return null;
109 }
110
111 @Override
112 public Void visitBranch(Instruction instr, int offset, Void p) {
113 return null;
114 }
115
116 @Override
117 public Void visitConstantPoolRef(Instruction instr, int index, Void p) {
118 checkIndirectRefToString(index);
119 return null;
120 }
121
122 @Override
123 public Void visitConstantPoolRefAndValue(Instruction instr, int index, int value, Void p) {
124 checkIndirectRefToString(index);
125 return null;
126 }
127
128 @Override
129 public Void visitLocal(Instruction instr, int index, Void p) {
130 return null;
131 }
132
133 @Override
134 public Void visitLocalAndValue(Instruction instr, int index, int value, Void p) {
135 return null;
136 }
137
138 @Override
139 public Void visitLookupSwitch(Instruction instr, int default_, int npairs, int[] matches, int[] offsets, Void p) {
140 return null;
141 }
142
143 @Override
144 public Void visitTableSwitch(Instruction instr, int default_, int low, int high, int[] offsets, Void p) {
145 return null;
146 }
147
148 @Override
149 public Void visitValue(Instruction instr, int value, Void p) {
150 return null;
151 }
152
153 @Override
154 public Void visitUnknown(Instruction instr, Void p) {
155 return null;
156 }
157
158 }
159
160 public class Test {
161 void methodToLookFor() {
162 try {
163 } finally {
164 System.out.println("STR_TO_LOOK_FOR");
165 }
166 }
167 }
168 }