All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.snapscript.asm.commons.AnalyzerAdapter Maven / Gradle / Ivy

There is a newer version: 1.4.6
Show newest version
/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.snapscript.asm.commons;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.snapscript.asm.Handle;
import org.snapscript.asm.Label;
import org.snapscript.asm.MethodVisitor;
import org.snapscript.asm.Opcodes;
import org.snapscript.asm.Type;

/**
 * A {@link MethodVisitor} that keeps track of stack map frame changes between
 * {@link #visitFrame(int, int, Object[], int, Object[]) visitFrame} calls. This
 * adapter must be used with the
 * {@link org.snapscript.asm.ClassReader#EXPAND_FRAMES} option. Each
 * visitX instruction delegates to the next visitor in the chain, if any,
 * and then simulates the effect of this instruction on the stack map frame,
 * represented by {@link #locals} and {@link #stack}. The next visitor in the
 * chain can get the state of the stack map frame before each instruction
 * by reading the value of these fields in its visitX methods (this
 * requires a reference to the AnalyzerAdapter that is before it in the chain).
 * If this adapter is used with a class that does not contain stack map table
 * attributes (i.e., pre Java 6 classes) then this adapter may not be able to
 * compute the stack map frame for each instruction. In this case no exception
 * is thrown but the {@link #locals} and {@link #stack} fields will be null for
 * these instructions.
 * 
 * @author Eric Bruneton
 */
public class AnalyzerAdapter extends MethodVisitor {

    /**
     * List of the local variable slots for current execution
     * frame. Primitive types are represented by {@link Opcodes#TOP},
     * {@link Opcodes#INTEGER}, {@link Opcodes#FLOAT}, {@link Opcodes#LONG},
     * {@link Opcodes#DOUBLE},{@link Opcodes#NULL} or
     * {@link Opcodes#UNINITIALIZED_THIS} (long and double are represented by
     * two elements, the second one being TOP). Reference types are represented
     * by String objects (representing internal names), and uninitialized types
     * by Label objects (this label designates the NEW instruction that created
     * this uninitialized value). This field is null for unreachable
     * instructions.
     */
    public List locals;

    /**
     * List of the operand stack slots for current execution frame.
     * Primitive types are represented by {@link Opcodes#TOP},
     * {@link Opcodes#INTEGER}, {@link Opcodes#FLOAT}, {@link Opcodes#LONG},
     * {@link Opcodes#DOUBLE},{@link Opcodes#NULL} or
     * {@link Opcodes#UNINITIALIZED_THIS} (long and double are represented by
     * two elements, the second one being TOP). Reference types are represented
     * by String objects (representing internal names), and uninitialized types
     * by Label objects (this label designates the NEW instruction that created
     * this uninitialized value). This field is null for unreachable
     * instructions.
     */
    public List stack;

    /**
     * The labels that designate the next instruction to be visited. May be
     * null.
     */
    private List