hotspot/agent/src/share/classes/sun/jvm/hotspot/oops/ConstMethod.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2003, 2012, 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.
  *
  * 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 sun.jvm.hotspot.oops;

 import java.io.*;
 import java.util.*;
 import sun.jvm.hotspot.code.*;
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.interpreter.*;
 import sun.jvm.hotspot.memory.*;
 import sun.jvm.hotspot.runtime.*;
 import sun.jvm.hotspot.types.*;
 import sun.jvm.hotspot.utilities.*;

 public class ConstMethod extends Oop {
   static {
     VM.registerVMInitializedObserver(new Observer() {
         public void update(Observable o, Object data) {
           initialize(VM.getVM().getTypeDataBase());
         }
       });
   }

   // anon-enum constants for _flags.
   private static int HAS_LINENUMBER_TABLE;
   private static int HAS_CHECKED_EXCEPTIONS;
   private static int HAS_LOCALVARIABLE_TABLE;
   private static int HAS_EXCEPTION_TABLE;

   private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
     Type type                  = db.lookupType("constMethodOopDesc");
     constants                  = new OopField(type.getOopField("_constants"), 0);
     constMethodSize            = new CIntField(type.getCIntegerField("_constMethod_size"), 0);
     flags                      = new ByteField(type.getJByteField("_flags"), 0);

     // enum constants for flags
     HAS_LINENUMBER_TABLE      = db.lookupIntConstant("constMethodOopDesc::_has_linenumber_table").intValue();
     HAS_CHECKED_EXCEPTIONS     = db.lookupIntConstant("constMethodOopDesc::_has_checked_exceptions").intValue();
     HAS_LOCALVARIABLE_TABLE   = db.lookupIntConstant("constMethodOopDesc::_has_localvariable_table").intValue();
     HAS_EXCEPTION_TABLE       = db.lookupIntConstant("constMethodOopDesc::_has_exception_table").intValue();

     // Size of Java bytecodes allocated immediately after constMethodOop.
     codeSize                   = new CIntField(type.getCIntegerField("_code_size"), 0);
     nameIndex                  = new CIntField(type.getCIntegerField("_name_index"), 0);
     signatureIndex             = new CIntField(type.getCIntegerField("_signature_index"), 0);
     genericSignatureIndex      = new CIntField(type.getCIntegerField("_generic_signature_index"),0);
     idnum                      = new CIntField(type.getCIntegerField("_method_idnum"), 0);

     // start of byte code
     bytecodeOffset = type.getSize();

     type                       = db.lookupType("CheckedExceptionElement");
     checkedExceptionElementSize = type.getSize();

     type                       = db.lookupType("LocalVariableTableElement");
     localVariableTableElementSize = type.getSize();

     type                       = db.lookupType("ExceptionTableElement");
     exceptionTableElementSize = type.getSize();
   }

   ConstMethod(OopHandle handle, ObjectHeap heap) {
     super(handle, heap);
   }

   // Fields
   private static OopField  constants;
   private static CIntField constMethodSize;
   private static ByteField flags;
   private static CIntField codeSize;
   private static CIntField nameIndex;
   private static CIntField signatureIndex;
   private static CIntField genericSignatureIndex;
   private static CIntField idnum;

   // start of bytecode
   private static long bytecodeOffset;

   private static long checkedExceptionElementSize;
   private static long localVariableTableElementSize;
   private static long exceptionTableElementSize;

   public Method getMethod() {
     InstanceKlass ik = (InstanceKlass)getConstants().getPoolHolder();
     ObjArray methods = ik.getMethods();
     return (Method)methods.getObjAt(getIdNum());
   }

   // Accessors for declared fields
   public ConstantPool getConstants() {
     return (ConstantPool) constants.getValue(this);
   }

   public long getConstMethodSize() {
     return constMethodSize.getValue(this);
   }

   public byte getFlags() {
     return flags.getValue(this);
   }

   public long getCodeSize() {
     return codeSize.getValue(this);
   }

   public long getNameIndex() {
     return nameIndex.getValue(this);
   }

   public long getSignatureIndex() {
     return signatureIndex.getValue(this);
   }

   public long getGenericSignatureIndex() {
     return genericSignatureIndex.getValue(this);
   }

   public long getIdNum() {
     return idnum.getValue(this);
   }

   public Symbol getName() {
     return getMethod().getName();
   }

   public Symbol getSignature() {
     return getMethod().getSignature();
   }

   public Symbol getGenericSignature() {
     return getMethod().getGenericSignature();
   }

   // bytecode accessors

   /** Get a bytecode or breakpoint at the given bci */
   public int getBytecodeOrBPAt(int bci) {
     return getHandle().getJByteAt(bytecodeOffset + bci) & 0xFF;
   }

   public byte getBytecodeByteArg(int bci) {
     return (byte) getBytecodeOrBPAt(bci);
   }

   /** Fetches a 16-bit big-endian ("Java ordered") value from the
       bytecode stream */
   public short getBytecodeShortArg(int bci) {
     int hi = getBytecodeOrBPAt(bci);
     int lo = getBytecodeOrBPAt(bci + 1);
     return (short) ((hi << 8) | lo);
   }

   /** Fetches a 16-bit native ordered value from the
       bytecode stream */
   public short getNativeShortArg(int bci) {
     int hi = getBytecodeOrBPAt(bci);
     int lo = getBytecodeOrBPAt(bci + 1);
     if (VM.getVM().isBigEndian()) {
         return (short) ((hi << 8) | lo);
     } else {
         return (short) ((lo << 8) | hi);
     }
   }

   /** Fetches a 32-bit big-endian ("Java ordered") value from the
       bytecode stream */
   public int getBytecodeIntArg(int bci) {
     int b4 = getBytecodeOrBPAt(bci);
     int b3 = getBytecodeOrBPAt(bci + 1);
     int b2 = getBytecodeOrBPAt(bci + 2);
     int b1 = getBytecodeOrBPAt(bci + 3);

     return (b4 << 24) | (b3 << 16) | (b2 << 8) | b1;
   }

   /** Fetches a 32-bit native ordered value from the
       bytecode stream */
   public int getNativeIntArg(int bci) {
     int b4 = getBytecodeOrBPAt(bci);
     int b3 = getBytecodeOrBPAt(bci + 1);
     int b2 = getBytecodeOrBPAt(bci + 2);
     int b1 = getBytecodeOrBPAt(bci + 3);

     if (VM.getVM().isBigEndian()) {
         return (b4 << 24) | (b3 << 16) | (b2 << 8) | b1;
     } else {
         return (b1 << 24) | (b2 << 16) | (b3 << 8) | b4;
     }
   }

   public byte[] getByteCode() {
      byte[] bc = new byte[ (int) getCodeSize() ];
      for( int i=0; i < bc.length; i++ )
      {
         long offs = bytecodeOffset + i;
         bc[i] = getHandle().getJByteAt( offs );
      }
      return bc;
   }

   public long getObjectSize() {
     return getConstMethodSize() * getHeap().getOopSize();
   }

   public void printValueOn(PrintStream tty) {
     tty.print("ConstMethod " + getName().asString() + getSignature().asString() + "@" + getHandle());
   }

   public void iterateFields(OopVisitor visitor, boolean doVMFields) {
     super.iterateFields(visitor, doVMFields);
     if (doVMFields) {
       visitor.doOop(constants, true);
       visitor.doCInt(constMethodSize, true);
       visitor.doByte(flags, true);
       visitor.doCInt(codeSize, true);
       visitor.doCInt(nameIndex, true);
       visitor.doCInt(signatureIndex, true);
       visitor.doCInt(genericSignatureIndex, true);
       visitor.doCInt(codeSize, true);
     }
   }

   // Accessors

   public boolean hasLineNumberTable() {
     return (getFlags() & HAS_LINENUMBER_TABLE) != 0;
   }

   public int getLineNumberFromBCI(int bci) {
     if (!VM.getVM().isCore()) {
       if (bci == DebugInformationRecorder.SYNCHRONIZATION_ENTRY_BCI) bci = 0;
     }

     if (isNative()) {
       return -1;
     }

     if (Assert.ASSERTS_ENABLED) {
       Assert.that(bci == 0 || 0 <= bci && bci < getCodeSize(), "illegal bci");
     }
     int bestBCI  =  0;
     int bestLine = -1;
     if (hasLineNumberTable()) {
       // The line numbers are a short array of 2-tuples [start_pc, line_number].
       // Not necessarily sorted and not necessarily one-to-one.
       CompressedLineNumberReadStream stream =
         new CompressedLineNumberReadStream(getHandle(), (int) offsetOfCompressedLineNumberTable());
       while (stream.readPair()) {
         if (stream.bci() == bci) {
           // perfect match
           return stream.line();
         } else {
           // update best_bci/line
           if (stream.bci() < bci && stream.bci() >= bestBCI) {
             bestBCI  = stream.bci();
             bestLine = stream.line();
           }
         }
       }
     }
     return bestLine;
   }

   public LineNumberTableElement[] getLineNumberTable() {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(hasLineNumberTable(),
                   "should only be called if table is present");
     }
     int len = getLineNumberTableLength();
     CompressedLineNumberReadStream stream =
       new CompressedLineNumberReadStream(getHandle(), (int) offsetOfCompressedLineNumberTable());
     LineNumberTableElement[] ret = new LineNumberTableElement[len];

     for (int idx = 0; idx < len; idx++) {
       stream.readPair();
       ret[idx] = new LineNumberTableElement(stream.bci(), stream.line());
     }
     return ret;
   }

   public boolean hasLocalVariableTable() {
     return (getFlags() & HAS_LOCALVARIABLE_TABLE) != 0;
   }

   public Symbol getLocalVariableName(int bci, int slot) {
     return getMethod().getLocalVariableName(bci, slot);
   }

   /** Should only be called if table is present */
   public LocalVariableTableElement[] getLocalVariableTable() {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(hasLocalVariableTable(), "should only be called if table is present");
     }
     LocalVariableTableElement[] ret = new LocalVariableTableElement[getLocalVariableTableLength()];
     long offset = offsetOfLocalVariableTable();
     for (int i = 0; i < ret.length; i++) {
       ret[i] = new LocalVariableTableElement(getHandle(), offset);
       offset += localVariableTableElementSize;
     }
     return ret;
   }

   public boolean hasExceptionTable() {
     return (getFlags() & HAS_EXCEPTION_TABLE) != 0;
   }

   public ExceptionTableElement[] getExceptionTable() {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(hasExceptionTable(), "should only be called if table is present");
     }
     ExceptionTableElement[] ret = new ExceptionTableElement[getExceptionTableLength()];
     long offset = offsetOfExceptionTable();
     for (int i = 0; i < ret.length; i++) {
       ret[i] = new ExceptionTableElement(getHandle(), offset);
       offset += exceptionTableElementSize;
     }
     return ret;
   }

   public boolean hasCheckedExceptions() {
     return (getFlags() & HAS_CHECKED_EXCEPTIONS) != 0;
   }

   public CheckedExceptionElement[] getCheckedExceptions() {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(hasCheckedExceptions(), "should only be called if table is present");
     }
     CheckedExceptionElement[] ret = new CheckedExceptionElement[getCheckedExceptionsLength()];
     long offset = offsetOfCheckedExceptions();
     for (int i = 0; i < ret.length; i++) {
       ret[i] = new CheckedExceptionElement(getHandle(), offset);
       offset += checkedExceptionElementSize;
     }
     return ret;
   }


   //---------------------------------------------------------------------------
   // Internals only below this point
   //

   private boolean isNative() {
     return getMethod().isNative();
   }

   // Offset of end of code
   private long offsetOfCodeEnd() {
     return bytecodeOffset + getCodeSize();
   }

   // Offset of start of compressed line number table (see methodOop.hpp)
   private long offsetOfCompressedLineNumberTable() {
     return offsetOfCodeEnd() + (isNative() ? 2 * VM.getVM().getAddressSize() : 0);
   }

   // Offset of last short in methodOop
   private long offsetOfLastU2Element() {
     return getObjectSize() - 2;
   }

   private long offsetOfCheckedExceptionsLength() {
     return offsetOfLastU2Element();
   }

   private int getCheckedExceptionsLength() {
     if (hasCheckedExceptions()) {
       return (int) getHandle().getCIntegerAt(offsetOfCheckedExceptionsLength(), 2, true);
     } else {
       return 0;
     }
   }

   // Offset of start of checked exceptions
   private long offsetOfCheckedExceptions() {
     long offset = offsetOfCheckedExceptionsLength();
     long length = getCheckedExceptionsLength();
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(length > 0, "should only be called if table is present");
     }
     offset -= length * checkedExceptionElementSize;
     return offset;
   }

   private int getLineNumberTableLength() {
     int len = 0;
     if (hasLineNumberTable()) {
       CompressedLineNumberReadStream stream =
         new CompressedLineNumberReadStream(getHandle(), (int) offsetOfCompressedLineNumberTable());
       while (stream.readPair()) {
         len += 1;
       }
     }
     return len;
   }

   private int getLocalVariableTableLength() {
     if (hasLocalVariableTable()) {
       return (int) getHandle().getCIntegerAt(offsetOfLocalVariableTableLength(), 2, true);
     } else {
       return 0;
     }
   }

   // Offset of local variable table length
   private long offsetOfLocalVariableTableLength() {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(hasLocalVariableTable(), "should only be called if table is present");
     }

     if (hasExceptionTable()) {
       return offsetOfExceptionTable() - 2;
     } else if (hasCheckedExceptions()) {
       return offsetOfCheckedExceptions() - 2;
     } else {
       return offsetOfLastU2Element();
     }
   }

   private long offsetOfLocalVariableTable() {
     long offset = offsetOfLocalVariableTableLength();
     long length = getLocalVariableTableLength();
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(length > 0, "should only be called if table is present");
     }
     offset -= length * localVariableTableElementSize;
     return offset;
   }

   private int getExceptionTableLength() {
     if (hasExceptionTable()) {
       return (int) getHandle().getCIntegerAt(offsetOfExceptionTableLength(), 2, true);
     } else {
       return 0;
     }
   }

   private long offsetOfExceptionTableLength() {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(hasExceptionTable(), "should only be called if table is present");
     }
     if (hasCheckedExceptions()) {
       return offsetOfCheckedExceptions() - 2;
     } else {
       return offsetOfLastU2Element();
     }
   }

   private long offsetOfExceptionTable() {
     long offset = offsetOfExceptionTableLength();
     long length = getExceptionTableLength();
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(length > 0, "should only be called if table is present");
     }
     offset -= length * exceptionTableElementSize;
     return offset;
   }

 }
	/*
	* Copyright (c) 2003, 2012, 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.
	*
	* 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 sun.jvm.hotspot.oops;

	import java.io.*;
	import java.util.*;
	import sun.jvm.hotspot.code.*;
	import sun.jvm.hotspot.debugger.*;
	import sun.jvm.hotspot.interpreter.*;
	import sun.jvm.hotspot.memory.*;
	import sun.jvm.hotspot.runtime.*;
	import sun.jvm.hotspot.types.*;
	import sun.jvm.hotspot.utilities.*;

	public class ConstMethod extends Oop {
	static {
	VM.registerVMInitializedObserver(new Observer() {
	public void update(Observable o, Object data) {
	initialize(VM.getVM().getTypeDataBase());
	}
	});
	}

	// anon-enum constants for _flags.
	private static int HAS_LINENUMBER_TABLE;
	private static int HAS_CHECKED_EXCEPTIONS;
	private static int HAS_LOCALVARIABLE_TABLE;
	private static int HAS_EXCEPTION_TABLE;

	private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
	Type type = db.lookupType("constMethodOopDesc");
	constants = new OopField(type.getOopField("_constants"), 0);
	constMethodSize = new CIntField(type.getCIntegerField("_constMethod_size"), 0);
	flags = new ByteField(type.getJByteField("_flags"), 0);

	// enum constants for flags
	HAS_LINENUMBER_TABLE = db.lookupIntConstant("constMethodOopDesc::_has_linenumber_table").intValue();
	HAS_CHECKED_EXCEPTIONS = db.lookupIntConstant("constMethodOopDesc::_has_checked_exceptions").intValue();
	HAS_LOCALVARIABLE_TABLE = db.lookupIntConstant("constMethodOopDesc::_has_localvariable_table").intValue();
	HAS_EXCEPTION_TABLE = db.lookupIntConstant("constMethodOopDesc::_has_exception_table").intValue();

	// Size of Java bytecodes allocated immediately after constMethodOop.
	codeSize = new CIntField(type.getCIntegerField("_code_size"), 0);
	nameIndex = new CIntField(type.getCIntegerField("_name_index"), 0);
	signatureIndex = new CIntField(type.getCIntegerField("_signature_index"), 0);
	genericSignatureIndex = new CIntField(type.getCIntegerField("_generic_signature_index"),0);
	idnum = new CIntField(type.getCIntegerField("_method_idnum"), 0);

	// start of byte code
	bytecodeOffset = type.getSize();

	type = db.lookupType("CheckedExceptionElement");
	checkedExceptionElementSize = type.getSize();

	type = db.lookupType("LocalVariableTableElement");
	localVariableTableElementSize = type.getSize();

	type = db.lookupType("ExceptionTableElement");
	exceptionTableElementSize = type.getSize();
	}

	ConstMethod(OopHandle handle, ObjectHeap heap) {
	super(handle, heap);
	}

	// Fields
	private static OopField constants;
	private static CIntField constMethodSize;
	private static ByteField flags;
	private static CIntField codeSize;
	private static CIntField nameIndex;
	private static CIntField signatureIndex;
	private static CIntField genericSignatureIndex;
	private static CIntField idnum;

	// start of bytecode
	private static long bytecodeOffset;

	private static long checkedExceptionElementSize;
	private static long localVariableTableElementSize;
	private static long exceptionTableElementSize;

	public Method getMethod() {
	InstanceKlass ik = (InstanceKlass)getConstants().getPoolHolder();
	ObjArray methods = ik.getMethods();
	return (Method)methods.getObjAt(getIdNum());
	}

	// Accessors for declared fields
	public ConstantPool getConstants() {
	return (ConstantPool) constants.getValue(this);
	}

	public long getConstMethodSize() {
	return constMethodSize.getValue(this);
	}

	public byte getFlags() {
	return flags.getValue(this);
	}

	public long getCodeSize() {
	return codeSize.getValue(this);
	}

	public long getNameIndex() {
	return nameIndex.getValue(this);
	}

	public long getSignatureIndex() {
	return signatureIndex.getValue(this);
	}

	public long getGenericSignatureIndex() {
	return genericSignatureIndex.getValue(this);
	}

	public long getIdNum() {
	return idnum.getValue(this);
	}

	public Symbol getName() {
	return getMethod().getName();
	}

	public Symbol getSignature() {
	return getMethod().getSignature();
	}

	public Symbol getGenericSignature() {
	return getMethod().getGenericSignature();
	}

	// bytecode accessors

	/** Get a bytecode or breakpoint at the given bci */
	public int getBytecodeOrBPAt(int bci) {
	return getHandle().getJByteAt(bytecodeOffset + bci) & 0xFF;
	}

	public byte getBytecodeByteArg(int bci) {
	return (byte) getBytecodeOrBPAt(bci);
	}

	/** Fetches a 16-bit big-endian ("Java ordered") value from the
	bytecode stream */
	public short getBytecodeShortArg(int bci) {
	int hi = getBytecodeOrBPAt(bci);
	int lo = getBytecodeOrBPAt(bci + 1);
	return (short) ((hi << 8) \| lo);
	}

	/** Fetches a 16-bit native ordered value from the
	bytecode stream */
	public short getNativeShortArg(int bci) {
	int hi = getBytecodeOrBPAt(bci);
	int lo = getBytecodeOrBPAt(bci + 1);
	if (VM.getVM().isBigEndian()) {
	return (short) ((hi << 8) \| lo);
	} else {
	return (short) ((lo << 8) \| hi);
	}
	}

	/** Fetches a 32-bit big-endian ("Java ordered") value from the
	bytecode stream */
	public int getBytecodeIntArg(int bci) {
	int b4 = getBytecodeOrBPAt(bci);
	int b3 = getBytecodeOrBPAt(bci + 1);
	int b2 = getBytecodeOrBPAt(bci + 2);
	int b1 = getBytecodeOrBPAt(bci + 3);

	return (b4 << 24) \| (b3 << 16) \| (b2 << 8) \| b1;
	}

	/** Fetches a 32-bit native ordered value from the
	bytecode stream */
	public int getNativeIntArg(int bci) {
	int b4 = getBytecodeOrBPAt(bci);
	int b3 = getBytecodeOrBPAt(bci + 1);
	int b2 = getBytecodeOrBPAt(bci + 2);
	int b1 = getBytecodeOrBPAt(bci + 3);

	if (VM.getVM().isBigEndian()) {
	return (b4 << 24) \| (b3 << 16) \| (b2 << 8) \| b1;
	} else {
	return (b1 << 24) \| (b2 << 16) \| (b3 << 8) \| b4;
	}
	}

	public byte[] getByteCode() {
	byte[] bc = new byte[ (int) getCodeSize() ];
	for( int i=0; i < bc.length; i++ )
	{
	long offs = bytecodeOffset + i;
	bc[i] = getHandle().getJByteAt( offs );
	}
	return bc;
	}

	public long getObjectSize() {
	return getConstMethodSize() * getHeap().getOopSize();
	}

	public void printValueOn(PrintStream tty) {
	tty.print("ConstMethod " + getName().asString() + getSignature().asString() + "@" + getHandle());
	}

	public void iterateFields(OopVisitor visitor, boolean doVMFields) {
	super.iterateFields(visitor, doVMFields);
	if (doVMFields) {
	visitor.doOop(constants, true);
	visitor.doCInt(constMethodSize, true);
	visitor.doByte(flags, true);
	visitor.doCInt(codeSize, true);
	visitor.doCInt(nameIndex, true);
	visitor.doCInt(signatureIndex, true);
	visitor.doCInt(genericSignatureIndex, true);
	visitor.doCInt(codeSize, true);
	}
	}

	// Accessors

	public boolean hasLineNumberTable() {
	return (getFlags() & HAS_LINENUMBER_TABLE) != 0;
	}

	public int getLineNumberFromBCI(int bci) {
	if (!VM.getVM().isCore()) {
	if (bci == DebugInformationRecorder.SYNCHRONIZATION_ENTRY_BCI) bci = 0;
	}

	if (isNative()) {
	return -1;
	}

	if (Assert.ASSERTS_ENABLED) {
	Assert.that(bci == 0 \|\| 0 <= bci && bci < getCodeSize(), "illegal bci");
	}
	int bestBCI = 0;
	int bestLine = -1;
	if (hasLineNumberTable()) {
	// The line numbers are a short array of 2-tuples [start_pc, line_number].
	// Not necessarily sorted and not necessarily one-to-one.
	CompressedLineNumberReadStream stream =
	new CompressedLineNumberReadStream(getHandle(), (int) offsetOfCompressedLineNumberTable());
	while (stream.readPair()) {
	if (stream.bci() == bci) {
	// perfect match
	return stream.line();
	} else {
	// update best_bci/line
	if (stream.bci() < bci && stream.bci() >= bestBCI) {
	bestBCI = stream.bci();
	bestLine = stream.line();
	}
	}
	}
	}
	return bestLine;
	}

	public LineNumberTableElement[] getLineNumberTable() {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(hasLineNumberTable(),
	"should only be called if table is present");
	}
	int len = getLineNumberTableLength();
	CompressedLineNumberReadStream stream =
	new CompressedLineNumberReadStream(getHandle(), (int) offsetOfCompressedLineNumberTable());
	LineNumberTableElement[] ret = new LineNumberTableElement[len];

	for (int idx = 0; idx < len; idx++) {
	stream.readPair();
	ret[idx] = new LineNumberTableElement(stream.bci(), stream.line());
	}
	return ret;
	}

	public boolean hasLocalVariableTable() {
	return (getFlags() & HAS_LOCALVARIABLE_TABLE) != 0;
	}

	public Symbol getLocalVariableName(int bci, int slot) {
	return getMethod().getLocalVariableName(bci, slot);
	}

	/** Should only be called if table is present */
	public LocalVariableTableElement[] getLocalVariableTable() {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(hasLocalVariableTable(), "should only be called if table is present");
	}
	LocalVariableTableElement[] ret = new LocalVariableTableElement[getLocalVariableTableLength()];
	long offset = offsetOfLocalVariableTable();
	for (int i = 0; i < ret.length; i++) {
	ret[i] = new LocalVariableTableElement(getHandle(), offset);
	offset += localVariableTableElementSize;
	}
	return ret;
	}

	public boolean hasExceptionTable() {
	return (getFlags() & HAS_EXCEPTION_TABLE) != 0;
	}

	public ExceptionTableElement[] getExceptionTable() {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(hasExceptionTable(), "should only be called if table is present");
	}
	ExceptionTableElement[] ret = new ExceptionTableElement[getExceptionTableLength()];
	long offset = offsetOfExceptionTable();
	for (int i = 0; i < ret.length; i++) {
	ret[i] = new ExceptionTableElement(getHandle(), offset);
	offset += exceptionTableElementSize;
	}
	return ret;
	}

	public boolean hasCheckedExceptions() {
	return (getFlags() & HAS_CHECKED_EXCEPTIONS) != 0;
	}

	public CheckedExceptionElement[] getCheckedExceptions() {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(hasCheckedExceptions(), "should only be called if table is present");
	}
	CheckedExceptionElement[] ret = new CheckedExceptionElement[getCheckedExceptionsLength()];
	long offset = offsetOfCheckedExceptions();
	for (int i = 0; i < ret.length; i++) {
	ret[i] = new CheckedExceptionElement(getHandle(), offset);
	offset += checkedExceptionElementSize;
	}
	return ret;
	}


	//---------------------------------------------------------------------------
	// Internals only below this point
	//

	private boolean isNative() {
	return getMethod().isNative();
	}

	// Offset of end of code
	private long offsetOfCodeEnd() {
	return bytecodeOffset + getCodeSize();
	}

	// Offset of start of compressed line number table (see methodOop.hpp)
	private long offsetOfCompressedLineNumberTable() {
	return offsetOfCodeEnd() + (isNative() ? 2 * VM.getVM().getAddressSize() : 0);
	}

	// Offset of last short in methodOop
	private long offsetOfLastU2Element() {
	return getObjectSize() - 2;
	}

	private long offsetOfCheckedExceptionsLength() {
	return offsetOfLastU2Element();
	}

	private int getCheckedExceptionsLength() {
	if (hasCheckedExceptions()) {
	return (int) getHandle().getCIntegerAt(offsetOfCheckedExceptionsLength(), 2, true);
	} else {
	return 0;
	}
	}

	// Offset of start of checked exceptions
	private long offsetOfCheckedExceptions() {
	long offset = offsetOfCheckedExceptionsLength();
	long length = getCheckedExceptionsLength();
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(length > 0, "should only be called if table is present");
	}
	offset -= length * checkedExceptionElementSize;
	return offset;
	}

	private int getLineNumberTableLength() {
	int len = 0;
	if (hasLineNumberTable()) {
	CompressedLineNumberReadStream stream =
	new CompressedLineNumberReadStream(getHandle(), (int) offsetOfCompressedLineNumberTable());
	while (stream.readPair()) {
	len += 1;
	}
	}
	return len;
	}

	private int getLocalVariableTableLength() {
	if (hasLocalVariableTable()) {
	return (int) getHandle().getCIntegerAt(offsetOfLocalVariableTableLength(), 2, true);
	} else {
	return 0;
	}
	}

	// Offset of local variable table length
	private long offsetOfLocalVariableTableLength() {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(hasLocalVariableTable(), "should only be called if table is present");
	}

	if (hasExceptionTable()) {
	return offsetOfExceptionTable() - 2;
	} else if (hasCheckedExceptions()) {
	return offsetOfCheckedExceptions() - 2;
	} else {
	return offsetOfLastU2Element();
	}
	}

	private long offsetOfLocalVariableTable() {
	long offset = offsetOfLocalVariableTableLength();
	long length = getLocalVariableTableLength();
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(length > 0, "should only be called if table is present");
	}
	offset -= length * localVariableTableElementSize;
	return offset;
	}

	private int getExceptionTableLength() {
	if (hasExceptionTable()) {
	return (int) getHandle().getCIntegerAt(offsetOfExceptionTableLength(), 2, true);
	} else {
	return 0;
	}
	}

	private long offsetOfExceptionTableLength() {
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(hasExceptionTable(), "should only be called if table is present");
	}
	if (hasCheckedExceptions()) {
	return offsetOfCheckedExceptions() - 2;
	} else {
	return offsetOfLastU2Element();
	}
	}

	private long offsetOfExceptionTable() {
	long offset = offsetOfExceptionTableLength();
	long length = getExceptionTableLength();
	if (Assert.ASSERTS_ENABLED) {
	Assert.that(length > 0, "should only be called if table is present");
	}
	offset -= length * exceptionTableElementSize;
	return offset;
	}

	}