bundles/org.apache.tomcat/src/org/apache/tomcat/util/bcel/classfile/Code.java - rap/org.apache.tomcat - Git at Google

 /*
  *  Licensed to the Apache Software Foundation (ASF) under one or more
  *  contributor license agreements.  See the NOTICE file distributed with
  *  this work for additional information regarding copyright ownership.
  *  The ASF licenses this file to You under the Apache License, Version 2.0
  *  (the "License"); you may not use this file except in compliance with
  *  the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing, software
  *  distributed under the License is distributed on an "AS IS" BASIS,
  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  *
  */
 package org.apache.tomcat.util.bcel.classfile;

 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;

 import org.apache.tomcat.util.bcel.Constants;

 /**
  * This class represents a chunk of Java byte code contained in a
  * method. It is instantiated by the
  * <em>Attribute.readAttribute()</em> method. A <em>Code</em>
  * attribute contains informations about operand stack, local
  * variables, byte code and the exceptions handled within this
  * method.
  *
  * This attribute has attributes itself, namely <em>LineNumberTable</em> which
  * is used for debugging purposes and <em>LocalVariableTable</em> which
  * contains information about the local variables.
  *
  * @version $Id: Code.java,v 1.1 2011/06/28 21:08:23 rherrmann Exp $
  * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
  * @see     Attribute
  * @see     CodeException
  * @see     LineNumberTable
  * @see LocalVariableTable
  */
 public final class Code extends Attribute {

     private static final long serialVersionUID = 8936843273318969602L;
     private int max_stack; // Maximum size of stack used by this method
     private int max_locals; // Number of local variables
     private int code_length; // Length of code in bytes
     private byte[] code; // Actual byte code
     private int exception_table_length;
     private CodeException[] exception_table; // Table of handled exceptions
     private int attributes_count; // Attributes of code: LineNumber
     private Attribute[] attributes; // or LocalVariable


     /**
      * @param name_index Index pointing to the name <em>Code</em>
      * @param length Content length in bytes
      * @param file Input stream
      * @param constant_pool Array of constants
      */
     Code(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
             throws IOException {
         // Initialize with some default values which will be overwritten later
         this(name_index, length, file.readUnsignedShort(), file.readUnsignedShort(), (byte[]) null,
                 (CodeException[]) null, (Attribute[]) null, constant_pool);
         code_length = file.readInt();
         code = new byte[code_length]; // Read byte code
         file.readFully(code);
         /* Read exception table that contains all regions where an exception
          * handler is active, i.e., a try { ... } catch() block.
          */
         exception_table_length = file.readUnsignedShort();
         exception_table = new CodeException[exception_table_length];
         for (int i = 0; i < exception_table_length; i++) {
             exception_table[i] = new CodeException(file);
         }
         /* Read all attributes, currently `LineNumberTable' and
          * `LocalVariableTable'
          */
         attributes_count = file.readUnsignedShort();
         attributes = new Attribute[attributes_count];
         for (int i = 0; i < attributes_count; i++) {
             attributes[i] = Attribute.readAttribute(file, constant_pool);
         }
         /* Adjust length, because of setAttributes in this(), s.b.  length
          * is incorrect, because it didn't take the internal attributes
          * into account yet! Very subtle bug, fixed in 3.1.1.
          */
         this.length = length;
     }


     /**
      * @param name_index Index pointing to the name <em>Code</em>
      * @param length Content length in bytes
      * @param max_stack Maximum size of stack
      * @param max_locals Number of local variables
      * @param code Actual byte code
      * @param exception_table Table of handled exceptions
      * @param attributes Attributes of code: LineNumber or LocalVariable
      * @param constant_pool Array of constants
      */
     public Code(int name_index, int length, int max_stack, int max_locals, byte[] code,
             CodeException[] exception_table, Attribute[] attributes, ConstantPool constant_pool) {
         super(Constants.ATTR_CODE, name_index, length, constant_pool);
         this.max_stack = max_stack;
         this.max_locals = max_locals;
         setCode(code);
         setExceptionTable(exception_table);
         setAttributes(attributes); // Overwrites length!
     }


     /**
      * Dump code attribute to file stream in binary format.
      *
      * @param file Output file stream
      * @throws IOException
      */
     @Override
     public final void dump( DataOutputStream file ) throws IOException {
         super.dump(file);
         file.writeShort(max_stack);
         file.writeShort(max_locals);
         file.writeInt(code_length);
         file.write(code, 0, code_length);
         file.writeShort(exception_table_length);
         for (int i = 0; i < exception_table_length; i++) {
             exception_table[i].dump(file);
         }
         file.writeShort(attributes_count);
         for (int i = 0; i < attributes_count; i++) {
             attributes[i].dump(file);
         }
     }


     /**
      * @return LocalVariableTable of Code, if it has one
      */
     public LocalVariableTable getLocalVariableTable() {
         for (int i = 0; i < attributes_count; i++) {
             if (attributes[i] instanceof LocalVariableTable) {
                 return (LocalVariableTable) attributes[i];
             }
         }
         return null;
     }


     /**
      * @return the internal length of this code attribute (minus the first 6 bytes)
      * and excluding all its attributes
      */
     private final int getInternalLength() {
         return 2 /*max_stack*/+ 2 /*max_locals*/+ 4 /*code length*/
                 + code_length /*byte-code*/
                 + 2 /*exception-table length*/
                 + 8 * exception_table_length /* exception table */
                 + 2 /* attributes count */;
     }


     /**
      * @return the full size of this code attribute, minus its first 6 bytes,
      * including the size of all its contained attributes
      */
     private final int calculateLength() {
         int len = 0;
         for (int i = 0; i < attributes_count; i++) {
             len += attributes[i].length + 6 /*attribute header size*/;
         }
         return len + getInternalLength();
     }


     /**
      * @param attributes the attributes to set for this Code
      */
     public final void setAttributes( Attribute[] attributes ) {
         this.attributes = attributes;
         attributes_count = (attributes == null) ? 0 : attributes.length;
         length = calculateLength(); // Adjust length
     }


     /**
      * @param code byte code
      */
     public final void setCode( byte[] code ) {
         this.code = code;
         code_length = (code == null) ? 0 : code.length;
     }


     /**
      * @param exception_table exception table
      */
     public final void setExceptionTable( CodeException[] exception_table ) {
         this.exception_table = exception_table;
         exception_table_length = (exception_table == null) ? 0 : exception_table.length;
     }


     /**
      * @return String representation of code chunk.
      */
     public final String toString( boolean verbose ) {
         StringBuffer buf;
         buf = new StringBuffer(100);
         buf.append("Code(max_stack = ").append(max_stack).append(", max_locals = ").append(
                 max_locals).append(", code_length = ").append(code_length).append(")\n").append(
                 Utility.codeToString(code, constant_pool, 0, -1, verbose));
         if (exception_table_length > 0) {
             buf.append("\nException handler(s) = \n").append("From\tTo\tHandler\tType\n");
             for (int i = 0; i < exception_table_length; i++) {
                 buf.append(exception_table[i].toString(constant_pool, verbose)).append("\n");
             }
         }
         if (attributes_count > 0) {
             buf.append("\nAttribute(s) = \n");
             for (int i = 0; i < attributes_count; i++) {
                 buf.append(attributes[i].toString()).append("\n");
             }
         }
         return buf.toString();
     }


     /**
      * @return String representation of code chunk.
      */
     @Override
     public final String toString() {
         return toString(true);
     }


     /**
      * @return deep copy of this attribute
      *
      * @param _constant_pool the constant pool to duplicate
      */
     @Override
     public Attribute copy( ConstantPool _constant_pool ) {
         Code c = (Code) clone();
         if (code != null) {
             c.code = new byte[code.length];
             System.arraycopy(code, 0, c.code, 0, code.length);
         }
         c.constant_pool = _constant_pool;
         c.exception_table = new CodeException[exception_table_length];
         for (int i = 0; i < exception_table_length; i++) {
             c.exception_table[i] = exception_table[i].copy();
         }
         c.attributes = new Attribute[attributes_count];
         for (int i = 0; i < attributes_count; i++) {
             c.attributes[i] = attributes[i].copy(_constant_pool);
         }
         return c;
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	*/
	package org.apache.tomcat.util.bcel.classfile;

	import java.io.DataInputStream;
	import java.io.DataOutputStream;
	import java.io.IOException;

	import org.apache.tomcat.util.bcel.Constants;

	/**
	* This class represents a chunk of Java byte code contained in a
	* method. It is instantiated by the
	* <em>Attribute.readAttribute()</em> method. A <em>Code</em>
	* attribute contains informations about operand stack, local
	* variables, byte code and the exceptions handled within this
	* method.
	*
	* This attribute has attributes itself, namely <em>LineNumberTable</em> which
	* is used for debugging purposes and <em>LocalVariableTable</em> which
	* contains information about the local variables.
	*
	* @version $Id: Code.java,v 1.1 2011/06/28 21:08:23 rherrmann Exp $
	* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
	* @see Attribute
	* @see CodeException
	* @see LineNumberTable
	* @see LocalVariableTable
	*/
	public final class Code extends Attribute {

	private static final long serialVersionUID = 8936843273318969602L;
	private int max_stack; // Maximum size of stack used by this method
	private int max_locals; // Number of local variables
	private int code_length; // Length of code in bytes
	private byte[] code; // Actual byte code
	private int exception_table_length;
	private CodeException[] exception_table; // Table of handled exceptions
	private int attributes_count; // Attributes of code: LineNumber
	private Attribute[] attributes; // or LocalVariable


	/**
	* @param name_index Index pointing to the name <em>Code</em>
	* @param length Content length in bytes
	* @param file Input stream
	* @param constant_pool Array of constants
	*/
	Code(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
	throws IOException {
	// Initialize with some default values which will be overwritten later
	this(name_index, length, file.readUnsignedShort(), file.readUnsignedShort(), (byte[]) null,
	(CodeException[]) null, (Attribute[]) null, constant_pool);
	code_length = file.readInt();
	code = new byte[code_length]; // Read byte code
	file.readFully(code);
	/* Read exception table that contains all regions where an exception
	* handler is active, i.e., a try { ... } catch() block.
	*/
	exception_table_length = file.readUnsignedShort();
	exception_table = new CodeException[exception_table_length];
	for (int i = 0; i < exception_table_length; i++) {
	exception_table[i] = new CodeException(file);
	}
	/* Read all attributes, currently `LineNumberTable' and
	* `LocalVariableTable'
	*/
	attributes_count = file.readUnsignedShort();
	attributes = new Attribute[attributes_count];
	for (int i = 0; i < attributes_count; i++) {
	attributes[i] = Attribute.readAttribute(file, constant_pool);
	}
	/* Adjust length, because of setAttributes in this(), s.b. length
	* is incorrect, because it didn't take the internal attributes
	* into account yet! Very subtle bug, fixed in 3.1.1.
	*/
	this.length = length;
	}


	/**
	* @param name_index Index pointing to the name <em>Code</em>
	* @param length Content length in bytes
	* @param max_stack Maximum size of stack
	* @param max_locals Number of local variables
	* @param code Actual byte code
	* @param exception_table Table of handled exceptions
	* @param attributes Attributes of code: LineNumber or LocalVariable
	* @param constant_pool Array of constants
	*/
	public Code(int name_index, int length, int max_stack, int max_locals, byte[] code,
	CodeException[] exception_table, Attribute[] attributes, ConstantPool constant_pool) {
	super(Constants.ATTR_CODE, name_index, length, constant_pool);
	this.max_stack = max_stack;
	this.max_locals = max_locals;
	setCode(code);
	setExceptionTable(exception_table);
	setAttributes(attributes); // Overwrites length!
	}


	/**
	* Dump code attribute to file stream in binary format.
	*
	* @param file Output file stream
	* @throws IOException
	*/
	@Override
	public final void dump( DataOutputStream file ) throws IOException {
	super.dump(file);
	file.writeShort(max_stack);
	file.writeShort(max_locals);
	file.writeInt(code_length);
	file.write(code, 0, code_length);
	file.writeShort(exception_table_length);
	for (int i = 0; i < exception_table_length; i++) {
	exception_table[i].dump(file);
	}
	file.writeShort(attributes_count);
	for (int i = 0; i < attributes_count; i++) {
	attributes[i].dump(file);
	}
	}


	/**
	* @return LocalVariableTable of Code, if it has one
	*/
	public LocalVariableTable getLocalVariableTable() {
	for (int i = 0; i < attributes_count; i++) {
	if (attributes[i] instanceof LocalVariableTable) {
	return (LocalVariableTable) attributes[i];
	}
	}
	return null;
	}


	/**
	* @return the internal length of this code attribute (minus the first 6 bytes)
	* and excluding all its attributes
	*/
	private final int getInternalLength() {
	return 2 /max_stack/+ 2 /max_locals/+ 4 /code length/
	+ code_length /byte-code/
	+ 2 /exception-table length/
	+ 8 * exception_table_length /* exception table */
	+ 2 /* attributes count */;
	}


	/**
	* @return the full size of this code attribute, minus its first 6 bytes,
	* including the size of all its contained attributes
	*/
	private final int calculateLength() {
	int len = 0;
	for (int i = 0; i < attributes_count; i++) {
	len += attributes[i].length + 6 /attribute header size/;
	}
	return len + getInternalLength();
	}


	/**
	* @param attributes the attributes to set for this Code
	*/
	public final void setAttributes( Attribute[] attributes ) {
	this.attributes = attributes;
	attributes_count = (attributes == null) ? 0 : attributes.length;
	length = calculateLength(); // Adjust length
	}


	/**
	* @param code byte code
	*/
	public final void setCode( byte[] code ) {
	this.code = code;
	code_length = (code == null) ? 0 : code.length;
	}


	/**
	* @param exception_table exception table
	*/
	public final void setExceptionTable( CodeException[] exception_table ) {
	this.exception_table = exception_table;
	exception_table_length = (exception_table == null) ? 0 : exception_table.length;
	}


	/**
	* @return String representation of code chunk.
	*/
	public final String toString( boolean verbose ) {
	StringBuffer buf;
	buf = new StringBuffer(100);
	buf.append("Code(max_stack = ").append(max_stack).append(", max_locals = ").append(
	max_locals).append(", code_length = ").append(code_length).append(")\n").append(
	Utility.codeToString(code, constant_pool, 0, -1, verbose));
	if (exception_table_length > 0) {
	buf.append("\nException handler(s) = \n").append("From\tTo\tHandler\tType\n");
	for (int i = 0; i < exception_table_length; i++) {
	buf.append(exception_table[i].toString(constant_pool, verbose)).append("\n");
	}
	}
	if (attributes_count > 0) {
	buf.append("\nAttribute(s) = \n");
	for (int i = 0; i < attributes_count; i++) {
	buf.append(attributes[i].toString()).append("\n");
	}
	}
	return buf.toString();
	}


	/**
	* @return String representation of code chunk.
	*/
	@Override
	public final String toString() {
	return toString(true);
	}


	/**
	* @return deep copy of this attribute
	*
	* @param _constant_pool the constant pool to duplicate
	*/
	@Override
	public Attribute copy( ConstantPool _constant_pool ) {
	Code c = (Code) clone();
	if (code != null) {
	c.code = new byte[code.length];
	System.arraycopy(code, 0, c.code, 0, code.length);
	}
	c.constant_pool = _constant_pool;
	c.exception_table = new CodeException[exception_table_length];
	for (int i = 0; i < exception_table_length; i++) {
	c.exception_table[i] = exception_table[i].copy();
	}
	c.attributes = new Attribute[attributes_count];
	for (int i = 0; i < attributes_count; i++) {
	c.attributes[i] = attributes[i].copy(_constant_pool);
	}
	return c;
	}
	}