/*
* Bytecode Analysis Framework
* Copyright (C) 2003,2004 University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs.ba.type;
/**
* Extended type codes used by StackAndLocalTypes and StackAndLocalTypeAnalysis
* for typing locals and stack values used in Java bytecode.
*
* @author David Hovemeyer
* @see TypeFrame
* @see TypeAnalysis
*/
public interface ExtendedTypes {
// FIXME: these values depend on those in org.apache.bcel.Constants.
// They need to be distinct from all type codes defined there.
// It would be nice if BCEL provided built-in functionality for
// some or all of these.
/**
* Special type code for the "Top" type in the lattice.
*/
public static final byte T_TOP = 17;
/**
* Special type that represents the value store in
* local <i>n+1</i> when a long value is stored in
* local <i>n</i>.
*/
public static final byte T_LONG_EXTRA = 18;
/**
* Special type that represents the value store in
* local <i>n+1</i> when a double value is stored in
* local <i>n</i>.
*/
public static final byte T_DOUBLE_EXTRA = 19;
/**
* Special type code for the "Bottom" type in the lattice.
*/
public static final byte T_BOTTOM = 20;
/**
* Special type code for the "Null" type.
* This is a type which is higher in the lattice than any object type,
* but lower than the overall Top type. It represents the type
* of the null value, which may logically be merged with any
* object type without loss of information.
*/
public static final byte T_NULL = 21;
/**
* Special type code for "Exception" object type,
* which is an instance of the ExceptionObjectType class.
* These instances maintain an ExceptionSet to keep track
* of possible exceptions that are feasible, and whether those
* exceptions are explicit or implicit.
*/
public static final byte T_EXCEPTION = 22;
/**
* A Type code that is available for "user-defined" types.
* Any type code equal or greated than this one is guaranteed
* to be distinct from both standard and extended types.
*/
public static final byte T_AVAIL_TYPE = 100;
}
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