001/***
002 * ASM: a very small and fast Java bytecode manipulation framework
003 * Copyright (c) 2000-2011 INRIA, France Telecom
004 * All rights reserved.
005 *
006 * Redistribution and use in source and binary forms, with or without
007 * modification, are permitted provided that the following conditions
008 * are met:
009 * 1. Redistributions of source code must retain the above copyright
010 *    notice, this list of conditions and the following disclaimer.
011 * 2. Redistributions in binary form must reproduce the above copyright
012 *    notice, this list of conditions and the following disclaimer in the
013 *    documentation and/or other materials provided with the distribution.
014 * 3. Neither the name of the copyright holders nor the names of its
015 *    contributors may be used to endorse or promote products derived from
016 *    this software without specific prior written permission.
017 *
018 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
019 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
020 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
021 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
022 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
023 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
024 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
025 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
026 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
027 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
028 * THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package io.ebean.enhance.asm.tree.analysis;
031
032import io.ebean.enhance.asm.Type;
033
034/**
035 * A {@link Value} that is represented by its type in a seven types type system.
036 * This type system distinguishes the UNINITIALZED, INT, FLOAT, LONG, DOUBLE,
037 * REFERENCE and RETURNADDRESS types.
038 * 
039 * @author Eric Bruneton
040 */
041public class BasicValue implements Value {
042
043    public static final BasicValue UNINITIALIZED_VALUE = new BasicValue(null);
044
045    public static final BasicValue INT_VALUE = new BasicValue(Type.INT_TYPE);
046
047    public static final BasicValue FLOAT_VALUE = new BasicValue(Type.FLOAT_TYPE);
048
049    public static final BasicValue LONG_VALUE = new BasicValue(Type.LONG_TYPE);
050
051    public static final BasicValue DOUBLE_VALUE = new BasicValue(
052            Type.DOUBLE_TYPE);
053
054    public static final BasicValue REFERENCE_VALUE = new BasicValue(
055            Type.getObjectType("java/lang/Object"));
056
057    public static final BasicValue RETURNADDRESS_VALUE = new BasicValue(
058            Type.VOID_TYPE);
059
060    private final Type type;
061
062    public BasicValue(final Type type) {
063        this.type = type;
064    }
065
066    public Type getType() {
067        return type;
068    }
069
070    public int getSize() {
071        return type == Type.LONG_TYPE || type == Type.DOUBLE_TYPE ? 2 : 1;
072    }
073
074    public boolean isReference() {
075        return type != null
076                && (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY);
077    }
078
079    @Override
080    public boolean equals(final Object value) {
081        if (value == this) {
082            return true;
083        } else if (value instanceof BasicValue) {
084            if (type == null) {
085                return ((BasicValue) value).type == null;
086            } else {
087                return type.equals(((BasicValue) value).type);
088            }
089        } else {
090            return false;
091        }
092    }
093
094    @Override
095    public int hashCode() {
096        return type == null ? 0 : type.hashCode();
097    }
098
099    @Override
100    public String toString() {
101        if (this == UNINITIALIZED_VALUE) {
102            return ".";
103        } else if (this == RETURNADDRESS_VALUE) {
104            return "A";
105        } else if (this == REFERENCE_VALUE) {
106            return "R";
107        } else {
108            return type.getDescriptor();
109        }
110    }
111}