Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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  */

 /*

  * @test

  * @bug 8022186

  * @summary javac generates dead code if a try with an empty body has a finalizer

  */

 import com.sun.tools.classfile.Attribute;

 import com.sun.tools.classfile.ClassFile;

 import com.sun.tools.classfile.Code_attribute;

 import com.sun.tools.classfile.ConstantPool;

 import com.sun.tools.classfile.ConstantPool.CONSTANT_String_info;

 import com.sun.tools.classfile.ConstantPool.CPInfo;

 import com.sun.tools.classfile.ConstantPool.InvalidIndex;

 import com.sun.tools.classfile.Instruction;

 import com.sun.tools.classfile.Instruction.KindVisitor;

 import com.sun.tools.classfile.Instruction.TypeKind;

 import com.sun.tools.classfile.Method;

 import com.sun.tools.javac.util.Assert;

 import java.io.BufferedInputStream;

 import java.nio.file.Files;

 import java.nio.file.Path;

 import java.nio.file.Paths;

 public class DeadCodeGeneratedForEmptyTryTest {

     public static void main(String[] args) throws Exception {

         new DeadCodeGeneratedForEmptyTryTest().run();

     }

     void run() throws Exception {

         checkClassFile(Paths.get(System.getProperty("test.classes"),

                 this.getClass().getName() + "$Test.class"));

     }

     int utf8Index;

     int numberOfRefToStr = 0;

     ConstantPool constantPool;

     void checkClassFile(final Path path) throws Exception {

         ClassFile classFile = ClassFile.read(

                 new BufferedInputStream(Files.newInputStream(path)));

         constantPool = classFile.constant_pool;

         utf8Index = constantPool.getUTF8Index("STR_TO_LOOK_FOR");

         for (Method method: classFile.methods) {

             if (method.getName(constantPool).equals("methodToLookFor")) {

                 Code_attribute codeAtt = (Code_attribute)method.attributes.get(Attribute.Code);

                 for (Instruction inst: codeAtt.getInstructions()) {

                     inst.accept(codeVisitor, null);

                 }

             }

         }

         Assert.check(numberOfRefToStr == 1,

                 "There should only be one reference to a CONSTANT_String_info structure in the generated code");

     }

     CodeVisitor codeVisitor = new CodeVisitor();

     class CodeVisitor implements KindVisitor<Void, Void> {

         void checkIndirectRefToString(int cp_index) {

             try {

                 CPInfo cInfo = constantPool.get(cp_index);

                 if (cInfo instanceof CONSTANT_String_info) {

                     CONSTANT_String_info strInfo = (CONSTANT_String_info)cInfo;

                     if (strInfo.string_index == utf8Index) {

                         numberOfRefToStr++;

                     }

                 }

             } catch (InvalidIndex ex) {

                 throw new AssertionError("invalid constant pool index at " + cp_index);

             }

         }

         @Override

         public Void visitNoOperands(Instruction instr, Void p) {

             return null;

         }

         @Override

         public Void visitArrayType(Instruction instr, TypeKind kind, Void p) {

             return null;

         }

         @Override

         public Void visitBranch(Instruction instr, int offset, Void p) {

             return null;

         }

         @Override

         public Void visitConstantPoolRef(Instruction instr, int index, Void p) {

             checkIndirectRefToString(index);

             return null;

         }

         @Override

         public Void visitConstantPoolRefAndValue(Instruction instr, int index, int value, Void p) {

             checkIndirectRefToString(index);

             return null;

         }

         @Override

         public Void visitLocal(Instruction instr, int index, Void p) {

             return null;

         }

         @Override

         public Void visitLocalAndValue(Instruction instr, int index, int value, Void p) {

             return null;

         }

         @Override

         public Void visitLookupSwitch(Instruction instr, int default_, int npairs, int[] matches, int[] offsets, Void p) {

             return null;

         }

         @Override

         public Void visitTableSwitch(Instruction instr, int default_, int low, int high, int[] offsets, Void p) {

             return null;

         }

         @Override

         public Void visitValue(Instruction instr, int value, Void p) {

             return null;

         }

         @Override

         public Void visitUnknown(Instruction instr, Void p) {

             return null;

         }

     }

     public class Test {

         void methodToLookFor() {

             try {

             } finally {

                 System.out.println("STR_TO_LOOK_FOR");

             }

         }

     }

 }