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