core/java12/com/vladium/jcd/cls/attribute/CodeAttribute_info.java - platform/external/emma - Git at Google

 /* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved.
  *
  * This program and the accompanying materials are made available under
  * the terms of the Common Public License v1.0 which accompanies this distribution,
  * and is available at http://www.eclipse.org/legal/cpl-v10.html
  *
  * $Id: CodeAttribute_info.java,v 1.1.1.1 2004/05/09 16:57:47 vlad_r Exp $
  */
 package com.vladium.jcd.cls.attribute;

 import java.io.IOException;

 import com.vladium.jcd.cls.ElementFactory;
 import com.vladium.jcd.cls.IAttributeCollection;
 import com.vladium.jcd.cls.IConstantCollection;
 import com.vladium.jcd.lib.UDataInputStream;
 import com.vladium.jcd.lib.UDataOutputStream;

 // ----------------------------------------------------------------------------
 /**
  * The Code attribute is a variable-length attribute used in the attributes
  * table of {@link com.vladium.jcd.cls.Method_info} structures. A Code attribute
  * contains the JVM instructions and auxiliary information for a single Java method,
  * instance initialization method, or class or interface initialization method.
  * Every Java Virtual Machine implementation must recognize Code attributes. There
  * must be exactly one Code attribute in each method_info structure.<P>
  *
  * The Code attribute has the format
  * <PRE>
  *  Code_attribute {
  *          u2 attribute_name_index;
  *          u4 attribute_length;
  *          u2 max_stack;
  *          u2 max_locals;
  *          u4 code_length;
  *          u1 code[code_length];
  *          u2 exception_table_length;
  *          {            u2 start_pc;
  *                        u2 end_pc;
  *                        u2  handler_pc;
  *                        u2  catch_type;
  *          }        exception_table[exception_table_length];
  *
  *          u2 attributes_count;
  *          attribute_info attributes[attributes_count];
  *  }
  * </PRE>
  *
  * The value of the max_stack item gives the maximum number of words on the operand
  * stack at any point during execution of this method.<P>
  *
  * The value of the max_locals item gives the number of local variables used by this
  * method, including the parameters passed to the method on invocation. The index of
  * the first local variable is 0 . The greatest local variable index for a one-word
  * value is max_locals-1 . The greatest local variable index for a two-word value is
  * max_locals-2.<P>
  *
  * The value of the code_length item gives the number of bytes in the code array for
  * this method. The value of code_length must be greater than zero; the code array must
  * not be empty.The code array gives the actual bytes of Java Virtual Machine code that
  * implement the method.<P>
  *
  * The value of the exception_table_length item gives the number of entries in the
  * exception_table table. Each entry in the exception_table array describes one
  * exception handler in the code array: see {@link Exception_info}.<P>
  *
  * The value of the attributes_count item indicates the number of attributes of the Code
  * attribute. Each value of the attributes table must be a variable-length attribute
  * structure. A Code attribute can have any number of optional attributes associated
  * with it.
  *
  * @author (C) 2001, Vlad Roubtsov
  */
 public
 final class CodeAttribute_info extends Attribute_info
 {
     // public: ................................................................


     public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];

     public int m_max_stack, m_max_locals;


     public CodeAttribute_info (final int attribute_name_index,
                                final int max_stack, int max_locals,
                                final byte [] code,
                                final IExceptionHandlerTable exceptionHandlerTable,
                                final IAttributeCollection attributes)
     {
         super (attribute_name_index, 8 + (code != null ? code.length : 0) + exceptionHandlerTable.length () + attributes.length ());

         m_max_stack = max_stack;
         m_max_locals = max_locals;

         m_code = (code != null ? code : EMPTY_BYTE_ARRAY);
         m_codeSize = m_code.length;

         m_exceptionHandlerTable = exceptionHandlerTable;
         m_attributes = attributes;
     }

     /**
      * NOTE: must also use getCodeSize()
      * @return
      */
     public final byte [] getCode ()
     {
         return m_code;
     }

     public final int getCodeSize ()
     {
         return m_codeSize;
     }

     public IAttributeCollection getAttributes ()
     {
         return m_attributes;
     }

     public IExceptionHandlerTable getExceptionTable ()
     {
         return m_exceptionHandlerTable;
     }

     public long length ()
     {
         return 14 + m_codeSize + m_exceptionHandlerTable.length () + m_attributes.length ();
     }

     // Visitor:

     public void accept (final IAttributeVisitor visitor, final Object ctx)
     {
         visitor.visit (this, ctx);
     }


     public String toString ()
     {
         String eol = System.getProperty ("line.separator");

         StringBuffer s = new StringBuffer ();

         s.append ("CodeAttribute_info: [attribute_name_index = " + m_name_index + ", attribute_length = " + m_attribute_length + "]" + eol);
         s.append ("    max_stack/max_locals = " + m_max_stack + '/' + m_max_locals + eol);
         s.append ("    code [length " + m_codeSize + "]" + eol);

         for (int a = 0; a < m_attributes.size (); ++ a)
         {
             s.append ("         " + m_attributes.get (a) + eol);
         }


         return s.toString ();
     }

     // Cloneable:

     /**
      * Performs a deep copy.
      */
     public Object clone ()
     {
         final CodeAttribute_info _clone = (CodeAttribute_info) super.clone ();

         // do deep copy:

         _clone.m_code = (m_codeSize == 0 ? EMPTY_BYTE_ARRAY : (byte []) m_code.clone ()); // does not trim
         _clone.m_exceptionHandlerTable = (IExceptionHandlerTable) m_exceptionHandlerTable.clone ();
         _clone.m_attributes = (IAttributeCollection) m_attributes.clone ();

         return _clone;
     }


     // IClassFormatOutput:

     public void writeInClassFormat (final UDataOutputStream out) throws IOException
     {
         super.writeInClassFormat (out);

         out.writeU2 (m_max_stack);
         out.writeU2 (m_max_locals);

         out.writeU4 (m_codeSize);
         out.write (m_code, 0, m_codeSize); // TODO: THIS IS WRONG

         m_exceptionHandlerTable.writeInClassFormat (out);
         m_attributes.writeInClassFormat (out);
     }


     public void setCode (final byte [] code, final int codeSize)
     {
         m_code = code;
         m_codeSize = codeSize;
     }

     // protected: .............................................................

     // package: ...............................................................


     CodeAttribute_info (final IConstantCollection constants,
                         final int attribute_name_index, final long attribute_length,
                         final UDataInputStream bytes)
         throws IOException
     {
         super (attribute_name_index, attribute_length);

         m_max_stack = bytes.readU2 ();
         m_max_locals = bytes.readU2 ();

         final long code_length = bytes.readU4 ();

         m_code = new byte [(int) code_length];
         bytes.readFully (m_code);
         m_codeSize = (int) code_length;


         final int exception_table_length = bytes.readU2 ();
         m_exceptionHandlerTable = AttributeElementFactory.newExceptionHandlerTable (exception_table_length);

         for (int i = 0; i < exception_table_length; ++ i)
         {
             Exception_info exception_info = new Exception_info (bytes);
             if (DEBUG) System.out.println ("\t[" + i + "] exception: " + exception_info);

             m_exceptionHandlerTable.add (exception_info);
         }


         // TODO: put this logic into AttributeCollection
         final int attributes_count = bytes.readU2 ();
         m_attributes = ElementFactory.newAttributeCollection (attributes_count);

         for (int i = 0; i < attributes_count; ++ i)
         {
             Attribute_info attribute_info = Attribute_info.new_Attribute_info (constants, bytes);
             if (DEBUG) System.out.println ("\t[" + i + "] attribute: " + attribute_info);

             m_attributes.add (attribute_info);
         }
     }

     // private: ...............................................................


     private byte [] m_code; // never null [valid content extent is m_codeSize]
     private int m_codeSize;

     private IExceptionHandlerTable m_exceptionHandlerTable; // never null
     private IAttributeCollection m_attributes; // never null


     private static final boolean DEBUG = false;

 } // end of class
 // ----------------------------------------------------------------------------
	/* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved.
	*
	* This program and the accompanying materials are made available under
	* the terms of the Common Public License v1.0 which accompanies this distribution,
	* and is available at http://www.eclipse.org/legal/cpl-v10.html
	*
	* $Id: CodeAttribute_info.java,v 1.1.1.1 2004/05/09 16:57:47 vlad_r Exp $
	*/
	package com.vladium.jcd.cls.attribute;

	import java.io.IOException;

	import com.vladium.jcd.cls.ElementFactory;
	import com.vladium.jcd.cls.IAttributeCollection;
	import com.vladium.jcd.cls.IConstantCollection;
	import com.vladium.jcd.lib.UDataInputStream;
	import com.vladium.jcd.lib.UDataOutputStream;

	// ----------------------------------------------------------------------------
	/**
	* The Code attribute is a variable-length attribute used in the attributes
	* table of {@link com.vladium.jcd.cls.Method_info} structures. A Code attribute
	* contains the JVM instructions and auxiliary information for a single Java method,
	* instance initialization method, or class or interface initialization method.
	* Every Java Virtual Machine implementation must recognize Code attributes. There
	* must be exactly one Code attribute in each method_info structure.<P>
	*
	* The Code attribute has the format
	* <PRE>
	* Code_attribute {
	* u2 attribute_name_index;
	* u4 attribute_length;
	* u2 max_stack;
	* u2 max_locals;
	* u4 code_length;
	* u1 code[code_length];
	* u2 exception_table_length;
	* { u2 start_pc;
	* u2 end_pc;
	* u2 handler_pc;
	* u2 catch_type;
	* } exception_table[exception_table_length];
	*
	* u2 attributes_count;
	* attribute_info attributes[attributes_count];
	* }
	* </PRE>
	*
	* The value of the max_stack item gives the maximum number of words on the operand
	* stack at any point during execution of this method.<P>
	*
	* The value of the max_locals item gives the number of local variables used by this
	* method, including the parameters passed to the method on invocation. The index of
	* the first local variable is 0 . The greatest local variable index for a one-word
	* value is max_locals-1 . The greatest local variable index for a two-word value is
	* max_locals-2.<P>
	*
	* The value of the code_length item gives the number of bytes in the code array for
	* this method. The value of code_length must be greater than zero; the code array must
	* not be empty.The code array gives the actual bytes of Java Virtual Machine code that
	* implement the method.<P>
	*
	* The value of the exception_table_length item gives the number of entries in the
	* exception_table table. Each entry in the exception_table array describes one
	* exception handler in the code array: see {@link Exception_info}.<P>
	*
	* The value of the attributes_count item indicates the number of attributes of the Code
	* attribute. Each value of the attributes table must be a variable-length attribute
	* structure. A Code attribute can have any number of optional attributes associated
	* with it.
	*
	* @author (C) 2001, Vlad Roubtsov
	*/
	public
	final class CodeAttribute_info extends Attribute_info
	{
	// public: ................................................................


	public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];

	public int m_max_stack, m_max_locals;



	public CodeAttribute_info (final int attribute_name_index,
	final int max_stack, int max_locals,
	final byte [] code,
	final IExceptionHandlerTable exceptionHandlerTable,
	final IAttributeCollection attributes)
	{
	super (attribute_name_index, 8 + (code != null ? code.length : 0) + exceptionHandlerTable.length () + attributes.length ());

	m_max_stack = max_stack;
	m_max_locals = max_locals;

	m_code = (code != null ? code : EMPTY_BYTE_ARRAY);
	m_codeSize = m_code.length;

	m_exceptionHandlerTable = exceptionHandlerTable;
	m_attributes = attributes;
	}

	/**
	* NOTE: must also use getCodeSize()
	* @return
	*/
	public final byte [] getCode ()
	{
	return m_code;
	}

	public final int getCodeSize ()
	{
	return m_codeSize;
	}

	public IAttributeCollection getAttributes ()
	{
	return m_attributes;
	}

	public IExceptionHandlerTable getExceptionTable ()
	{
	return m_exceptionHandlerTable;
	}

	public long length ()
	{
	return 14 + m_codeSize + m_exceptionHandlerTable.length () + m_attributes.length ();
	}

	// Visitor:

	public void accept (final IAttributeVisitor visitor, final Object ctx)
	{
	visitor.visit (this, ctx);
	}


	public String toString ()
	{
	String eol = System.getProperty ("line.separator");

	StringBuffer s = new StringBuffer ();

	s.append ("CodeAttribute_info: [attribute_name_index = " + m_name_index + ", attribute_length = " + m_attribute_length + "]" + eol);
	s.append (" max_stack/max_locals = " + m_max_stack + '/' + m_max_locals + eol);
	s.append (" code [length " + m_codeSize + "]" + eol);

	for (int a = 0; a < m_attributes.size (); ++ a)
	{
	s.append (" " + m_attributes.get (a) + eol);
	}


	return s.toString ();
	}

	// Cloneable:

	/**
	* Performs a deep copy.
	*/
	public Object clone ()
	{
	final CodeAttribute_info _clone = (CodeAttribute_info) super.clone ();

	// do deep copy:

	_clone.m_code = (m_codeSize == 0 ? EMPTY_BYTE_ARRAY : (byte []) m_code.clone ()); // does not trim
	_clone.m_exceptionHandlerTable = (IExceptionHandlerTable) m_exceptionHandlerTable.clone ();
	_clone.m_attributes = (IAttributeCollection) m_attributes.clone ();

	return _clone;
	}


	// IClassFormatOutput:

	public void writeInClassFormat (final UDataOutputStream out) throws IOException
	{
	super.writeInClassFormat (out);

	out.writeU2 (m_max_stack);
	out.writeU2 (m_max_locals);

	out.writeU4 (m_codeSize);
	out.write (m_code, 0, m_codeSize); // TODO: THIS IS WRONG

	m_exceptionHandlerTable.writeInClassFormat (out);
	m_attributes.writeInClassFormat (out);
	}


	public void setCode (final byte [] code, final int codeSize)
	{
	m_code = code;
	m_codeSize = codeSize;
	}

	// protected: .............................................................

	// package: ...............................................................


	CodeAttribute_info (final IConstantCollection constants,
	final int attribute_name_index, final long attribute_length,
	final UDataInputStream bytes)
	throws IOException
	{
	super (attribute_name_index, attribute_length);

	m_max_stack = bytes.readU2 ();
	m_max_locals = bytes.readU2 ();

	final long code_length = bytes.readU4 ();

	m_code = new byte [(int) code_length];
	bytes.readFully (m_code);
	m_codeSize = (int) code_length;


	final int exception_table_length = bytes.readU2 ();
	m_exceptionHandlerTable = AttributeElementFactory.newExceptionHandlerTable (exception_table_length);

	for (int i = 0; i < exception_table_length; ++ i)
	{
	Exception_info exception_info = new Exception_info (bytes);
	if (DEBUG) System.out.println ("\t[" + i + "] exception: " + exception_info);

	m_exceptionHandlerTable.add (exception_info);
	}


	// TODO: put this logic into AttributeCollection
	final int attributes_count = bytes.readU2 ();
	m_attributes = ElementFactory.newAttributeCollection (attributes_count);

	for (int i = 0; i < attributes_count; ++ i)
	{
	Attribute_info attribute_info = Attribute_info.new_Attribute_info (constants, bytes);
	if (DEBUG) System.out.println ("\t[" + i + "] attribute: " + attribute_info);

	m_attributes.add (attribute_info);
	}
	}

	// private: ...............................................................


	private byte [] m_code; // never null [valid content extent is m_codeSize]
	private int m_codeSize;

	private IExceptionHandlerTable m_exceptionHandlerTable; // never null
	private IAttributeCollection m_attributes; // never null


	private static final boolean DEBUG = false;

	} // end of class
	// ----------------------------------------------------------------------------