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

 /*

  * Copyright (c) 2007, 2009, 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

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package com.sun.tools.classfile;

 import java.io.IOException;

 import java.util.Iterator;

 import java.util.NoSuchElementException;

 /**

  * See JVMS, section 4.8.3.

  *

  *  <p><b>This is NOT part of any supported API.

  *  If you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public class Code_attribute extends Attribute {

     public class InvalidIndex extends AttributeException {

         private static final long serialVersionUID = -8904527774589382802L;

         InvalidIndex(int index) {

             this.index = index;

         }

         @Override

         public String getMessage() {

             // i18n

             return "invalid index " + index + " in Code attribute";

         }

         public final int index;

     }

     Code_attribute(ClassReader cr, int name_index, int length)

             throws IOException, ConstantPoolException {

         super(name_index, length);

         max_stack = cr.readUnsignedShort();

         max_locals = cr.readUnsignedShort();

         code_length = cr.readInt();

         code = new byte[code_length];

         cr.readFully(code);

         exception_table_langth = cr.readUnsignedShort();

         exception_table = new Exception_data[exception_table_langth];

         for (int i = 0; i < exception_table_langth; i++)

             exception_table[i] = new Exception_data(cr);

         attributes = new Attributes(cr);

     }

     public int getByte(int offset) throws InvalidIndex {

         if (offset < 0 || offset >= code.length)

             throw new InvalidIndex(offset);

         return code[offset];

     }

     public int getUnsignedByte(int offset) throws InvalidIndex {

         if (offset < 0 || offset >= code.length)

             throw new InvalidIndex(offset);

         return code[offset] & 0xff;

     }

     public int getShort(int offset) throws InvalidIndex {

         if (offset < 0 || offset + 1 >= code.length)

             throw new InvalidIndex(offset);

         return (code[offset] << 8) | (code[offset + 1] & 0xFF);

     }

     public int getUnsignedShort(int offset) throws InvalidIndex {

         if (offset < 0 || offset + 1 >= code.length)

             throw new InvalidIndex(offset);

         return ((code[offset] << 8) | (code[offset + 1] & 0xFF)) & 0xFFFF;

     }

     public int getInt(int offset) throws InvalidIndex {

         if (offset < 0 || offset + 3 >= code.length)

             throw new InvalidIndex(offset);

         return (getShort(offset) << 16) | (getShort(offset + 2) & 0xFFFF);

     }

     public <R, D> R accept(Visitor<R, D> visitor, D data) {

         return visitor.visitCode(this, data);

     }

     public Iterable<Instruction> getInstructions() {

         return new Iterable<Instruction>() {

             public Iterator<Instruction> iterator() {

                 return new Iterator<Instruction>() {

                     public boolean hasNext() {

                         return (next != null);

                     }

                     public Instruction next() {

                         if (next == null)

                             throw new NoSuchElementException();

                         current = next;

                         pc += current.length();

                         next = (pc < code.length ? new Instruction(code, pc) : null);

                         return current;

                     }

                     public void remove() {

                         throw new UnsupportedOperationException("Not supported.");

                     }

                     Instruction current = null;

                     int pc = 0;

                     Instruction next = new Instruction(code, pc);

                 };

             }

         };

     }

     public final int max_stack;

     public final int max_locals;

     public final int code_length;

     public final byte[] code;

     public final int exception_table_langth;

     public final Exception_data[] exception_table;

     public final Attributes attributes;

     public class Exception_data {

         Exception_data(ClassReader cr) throws IOException {

             start_pc = cr.readUnsignedShort();

             end_pc = cr.readUnsignedShort();

             handler_pc = cr.readUnsignedShort();

             catch_type = cr.readUnsignedShort();

         }

         public final int start_pc;

         public final int end_pc;

         public final int handler_pc;

         public final int catch_type;

     }

 }