jjg@46: /*
jjg@1648:  * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
jjg@46:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jjg@46:  *
jjg@46:  * This code is free software; you can redistribute it and/or modify it
jjg@46:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
jjg@46:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
jjg@46:  *
jjg@46:  * This code is distributed in the hope that it will be useful, but WITHOUT
jjg@46:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jjg@46:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jjg@46:  * version 2 for more details (a copy is included in the LICENSE file that
jjg@46:  * accompanied this code).
jjg@46:  *
jjg@46:  * You should have received a copy of the GNU General Public License version
jjg@46:  * 2 along with this work; if not, write to the Free Software Foundation,
jjg@46:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jjg@46:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
jjg@46:  */
jjg@46: 
jjg@46: package com.sun.tools.classfile;
jjg@46: 
jjg@46: import java.io.IOException;
jjg@255: import java.util.Iterator;
jjg@255: import java.util.NoSuchElementException;
jjg@46: 
jjg@46: /**
jjh@972:  * See JVMS, section 4.8.3.
jjg@46:  *
jjg@581:  *  <p><b>This is NOT part of any supported API.
jjg@581:  *  If you write code that depends on this, you do so at your own risk.
jjg@46:  *  This code and its internal interfaces are subject to change or
jjg@46:  *  deletion without notice.</b>
jjg@46:  */
jjg@46: public class Code_attribute extends Attribute {
jjg@1648:     public static class InvalidIndex extends AttributeException {
jjg@198:         private static final long serialVersionUID = -8904527774589382802L;
jjg@46:         InvalidIndex(int index) {
jjg@46:             this.index = index;
jjg@46:         }
jjg@46: 
jjg@46:         @Override
jjg@46:         public String getMessage() {
jjg@46:             // i18n
jjg@46:             return "invalid index " + index + " in Code attribute";
jjg@46:         }
jjg@46: 
jjg@46:         public final int index;
jjg@46:     }
jjg@46: 
jjg@46:     Code_attribute(ClassReader cr, int name_index, int length)
jjg@46:             throws IOException, ConstantPoolException {
jjg@46:         super(name_index, length);
jjg@46:         max_stack = cr.readUnsignedShort();
jjg@46:         max_locals = cr.readUnsignedShort();
jjg@46:         code_length = cr.readInt();
jjg@46:         code = new byte[code_length];
jjg@46:         cr.readFully(code);
alundblad@2034:         exception_table_length = cr.readUnsignedShort();
alundblad@2034:         exception_table = new Exception_data[exception_table_length];
alundblad@2034:         for (int i = 0; i < exception_table_length; i++)
jjg@46:             exception_table[i] = new Exception_data(cr);
jjg@46:         attributes = new Attributes(cr);
jjg@46:     }
jjg@46: 
jjg@46:     public int getByte(int offset) throws InvalidIndex {
jjg@46:         if (offset < 0 || offset >= code.length)
jjg@46:             throw new InvalidIndex(offset);
jjg@46:         return code[offset];
jjg@46:     }
jjg@46: 
jjg@46:     public int getUnsignedByte(int offset) throws InvalidIndex {
jjg@46:         if (offset < 0 || offset >= code.length)
jjg@46:             throw new InvalidIndex(offset);
jjg@46:         return code[offset] & 0xff;
jjg@46:     }
jjg@46: 
jjg@46:     public int getShort(int offset) throws InvalidIndex {
jjg@46:         if (offset < 0 || offset + 1 >= code.length)
jjg@46:             throw new InvalidIndex(offset);
jjg@46:         return (code[offset] << 8) | (code[offset + 1] & 0xFF);
jjg@46:     }
jjg@46: 
jjg@46:     public int getUnsignedShort(int offset) throws InvalidIndex {
jjg@46:         if (offset < 0 || offset + 1 >= code.length)
jjg@46:             throw new InvalidIndex(offset);
jjg@46:         return ((code[offset] << 8) | (code[offset + 1] & 0xFF)) & 0xFFFF;
jjg@46:     }
jjg@46: 
jjg@46:     public int getInt(int offset) throws InvalidIndex {
jjg@46:         if (offset < 0 || offset + 3 >= code.length)
jjg@46:             throw new InvalidIndex(offset);
jjg@46:         return (getShort(offset) << 16) | (getShort(offset + 2) & 0xFFFF);
jjg@46:     }
jjg@46: 
jjg@46:     public <R, D> R accept(Visitor<R, D> visitor, D data) {
jjg@46:         return visitor.visitCode(this, data);
jjg@46:     }
jjg@46: 
jjg@255:     public Iterable<Instruction> getInstructions() {
jjg@255:         return new Iterable<Instruction>() {
jjg@255:             public Iterator<Instruction> iterator() {
jjg@255:                 return new Iterator<Instruction>() {
jjg@255: 
jjg@255:                     public boolean hasNext() {
jjg@255:                         return (next != null);
jjg@255:                     }
jjg@255: 
jjg@255:                     public Instruction next() {
jjg@255:                         if (next == null)
jjg@255:                             throw new NoSuchElementException();
jjg@255: 
jjg@255:                         current = next;
jjg@255:                         pc += current.length();
jjg@255:                         next = (pc < code.length ? new Instruction(code, pc) : null);
jjg@255:                         return current;
jjg@255:                     }
jjg@255: 
jjg@255:                     public void remove() {
jjg@255:                         throw new UnsupportedOperationException("Not supported.");
jjg@255:                     }
jjg@255: 
jjg@255:                     Instruction current = null;
jjg@255:                     int pc = 0;
jjg@255:                     Instruction next = new Instruction(code, pc);
jjg@255: 
jjg@255:                 };
jjg@255:             }
jjg@255: 
jjg@255:         };
jjg@255:     }
jjg@255: 
jjg@46:     public final int max_stack;
jjg@46:     public final int max_locals;
jjg@46:     public final int code_length;
jjg@46:     public final byte[] code;
alundblad@2034:     public final int exception_table_length;
jjg@46:     public final Exception_data[] exception_table;
jjg@46:     public final Attributes attributes;
jjg@46: 
jjg@1648:     public static class Exception_data {
jjg@46:         Exception_data(ClassReader cr) throws IOException {
jjg@46:             start_pc = cr.readUnsignedShort();
jjg@46:             end_pc = cr.readUnsignedShort();
jjg@46:             handler_pc = cr.readUnsignedShort();
jjg@46:             catch_type = cr.readUnsignedShort();
jjg@46:         }
jjg@46: 
jjg@46:         public final int start_pc;
jjg@46:         public final int end_pc;
jjg@46:         public final int handler_pc;
jjg@46:         public final int catch_type;
jjg@46:     }
jjg@46: }