processor.java

ProGuard 是一个免费的 Java类文件的压缩

/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2007 Eric Lafortune ([e-mail])
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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 for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.evaluation;

import proguard.classfile.*;
import proguard.classfile.attribute.CodeAttribute;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.*;
import proguard.evaluation.value.*;

/**
 * This InstructionVisitor executes the instructions that it visits on a given
 * local variable frame and stack.
 *
 * @author Eric Lafortune
 */
public class Processor
extends      SimplifiedVisitor
implements   InstructionVisitor,
             ConstantVisitor
{
    private Variables      variables;
    private Stack          stack;
    private ValueFactory   valueFactory;
    private BranchUnit     branchUnit;
    private InvocationUnit invocationUnit;

    // Fields acting as parameters for the ConstantVisitor methods.
    private boolean handleClassConstantAsClassValue;
    private Value   cpValue;


    /**
     * Creates a new processor that operates on the given environment.
     * @param variables      the local variable frame.
     * @param stack          the local stack.
     * @param branchUnit     the class that can affect the program counter.
     * @param invocationUnit the class that can access other program members.
     */
    public Processor(Variables      variables,
                     Stack          stack,
                     ValueFactory   valueFactory,
                     BranchUnit     branchUnit,
                     InvocationUnit invocationUnit)
    {
        this.variables      = variables;
        this.stack          = stack;
        this.valueFactory   = valueFactory;
        this.branchUnit     = branchUnit;
        this.invocationUnit = invocationUnit;
    }


    // Implementations for InstructionVisitor.

    public void visitSimpleInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, SimpleInstruction simpleInstruction)
    {
        switch (simpleInstruction.opcode)
        {
            case InstructionConstants.OP_NOP:
                break;

            case InstructionConstants.OP_ACONST_NULL:
                stack.push(valueFactory.createReferenceValueNull());
                break;

            case InstructionConstants.OP_ICONST_M1:
            case InstructionConstants.OP_ICONST_0:
            case InstructionConstants.OP_ICONST_1:
            case InstructionConstants.OP_ICONST_2:
            case InstructionConstants.OP_ICONST_3:
            case InstructionConstants.OP_ICONST_4:
            case InstructionConstants.OP_ICONST_5:
            case InstructionConstants.OP_BIPUSH:
            case InstructionConstants.OP_SIPUSH:
                stack.push(valueFactory.createIntegerValue(simpleInstruction.constant));
                break;

            case InstructionConstants.OP_LCONST_0:
            case InstructionConstants.OP_LCONST_1:
                stack.push(valueFactory.createLongValue(simpleInstruction.constant));
                break;

            case InstructionConstants.OP_FCONST_0:
            case InstructionConstants.OP_FCONST_1:
            case InstructionConstants.OP_FCONST_2:
                stack.push(valueFactory.createFloatValue((float)simpleInstruction.constant));
                break;

            case InstructionConstants.OP_DCONST_0:
            case InstructionConstants.OP_DCONST_1:
                stack.push(valueFactory.createDoubleValue((double)simpleInstruction.constant));
                break;

            case InstructionConstants.OP_IALOAD:
            case InstructionConstants.OP_BALOAD:
            case InstructionConstants.OP_CALOAD:
            case InstructionConstants.OP_SALOAD:
                stack.ipop();
                stack.apop();
                stack.push(valueFactory.createIntegerValue());
                break;

            case InstructionConstants.OP_LALOAD:
                stack.ipop();
                stack.apop();
                stack.push(valueFactory.createLongValue());
                break;

            case InstructionConstants.OP_FALOAD:
                stack.ipop();
                stack.apop();
                stack.push(valueFactory.createFloatValue());
                break;

            case InstructionConstants.OP_DALOAD:
                stack.ipop();
                stack.apop();
                stack.push(valueFactory.createDoubleValue());
                break;

            case InstructionConstants.OP_AALOAD:
            {
                IntegerValue   arrayIndex     = stack.ipop();
                ReferenceValue arrayReference = stack.apop();
                stack.push(arrayReference.arrayLoad(arrayIndex, valueFactory));
                break;
            }

            case InstructionConstants.OP_IASTORE:
            case InstructionConstants.OP_BASTORE:
            case InstructionConstants.OP_CASTORE:
            case InstructionConstants.OP_SASTORE:
                stack.ipop();
                stack.ipop();
                stack.apop();
                break;

            case InstructionConstants.OP_LASTORE:
                stack.lpop();
                stack.ipop();
                stack.apop();
                break;

            case InstructionConstants.OP_FASTORE:
                stack.fpop();
                stack.ipop();
                stack.apop();
                break;

            case InstructionConstants.OP_DASTORE:
                stack.dpop();
                stack.ipop();
                stack.apop();
                break;

            case InstructionConstants.OP_AASTORE:
                stack.apop();
                stack.ipop();
                stack.apop();
                break;

            case InstructionConstants.OP_POP:
                stack.pop1();
                break;

            case InstructionConstants.OP_POP2:
                stack.pop2();
                break;

            case InstructionConstants.OP_DUP:
                stack.dup();
                break;

            case InstructionConstants.OP_DUP_X1:
                stack.dup_x1();
                break;

            case InstructionConstants.OP_DUP_X2:
                stack.dup_x2();
                break;

            case InstructionConstants.OP_DUP2:
                stack.dup2();
                break;

            case InstructionConstants.OP_DUP2_X1:
                stack.dup2_x1();
                break;

            case InstructionConstants.OP_DUP2_X2:
                stack.dup2_x2();
                break;

            case InstructionConstants.OP_SWAP:
                stack.swap();
                break;

            case InstructionConstants.OP_IADD:
                stack.push(stack.ipop().add(stack.ipop()));
                break;

            case InstructionConstants.OP_LADD:
                stack.push(stack.lpop().add(stack.lpop()));
                break;

            case InstructionConstants.OP_FADD:
                stack.push(stack.fpop().add(stack.fpop()));
                break;

            case InstructionConstants.OP_DADD:
                stack.push(stack.dpop().add(stack.dpop()));
                break;

            case InstructionConstants.OP_ISUB:
                stack.push(stack.ipop().subtractFrom(stack.ipop()));
                break;

            case InstructionConstants.OP_LSUB:
                stack.push(stack.lpop().subtractFrom(stack.lpop()));
                break;

            case InstructionConstants.OP_FSUB:
                stack.push(stack.fpop().subtractFrom(stack.fpop()));
                break;

            case InstructionConstants.OP_DSUB:
                stack.push(stack.dpop().subtractFrom(stack.dpop()));
                break;

            case InstructionConstants.OP_IMUL:
                stack.push(stack.ipop().multiply(stack.ipop()));
                break;

            case InstructionConstants.OP_LMUL:
                stack.push(stack.lpop().multiply(stack.lpop()));
                break;

            case InstructionConstants.OP_FMUL:
                stack.push(stack.fpop().multiply(stack.fpop()));
                break;

            case InstructionConstants.OP_DMUL:
                stack.push(stack.dpop().multiply(stack.dpop()));
                break;

            case InstructionConstants.OP_IDIV:
                try
                {
                    stack.push(stack.ipop().divideOf(stack.ipop()));
                }
                catch (ArithmeticException ex)
                {
                    stack.push(valueFactory.createIntegerValue());
                    // TODO: Forward ArithmeticExceptions.
                    //stack.clear();
                    //stack.push(valueFactory.createReference(false));
                    //branchUnit.throwException();
                }
                break;

            case InstructionConstants.OP_LDIV:
                try
                {
                    stack.push(stack.lpop().divideOf(stack.lpop()));
                }
                catch (ArithmeticException ex)
                {
                    stack.push(valueFactory.createLongValue());
                    // TODO: Forward ArithmeticExceptions.
                    //stack.clear();
                    //stack.push(valueFactory.createReference(false));
                    //branchUnit.throwException();
                }
                break;

            case InstructionConstants.OP_FDIV:
                stack.push(stack.fpop().divideOf(stack.fpop()));
                break;

            case InstructionConstants.OP_DDIV:
                stack.push(stack.dpop().divideOf(stack.dpop()));
                break;

            case InstructionConstants.OP_IREM:
                try
                {
                    stack.push(stack.ipop().remainderOf(stack.ipop()));
                }
                catch (ArithmeticException ex)
                {
                    stack.push(valueFactory.createIntegerValue());
                    // TODO: Forward ArithmeticExceptions.
                    //stack.clear();
                    //stack.push(valueFactory.createReference(false));
                    //branchUnit.throwException();
                }
                break;

            case InstructionConstants.OP_LREM:
                try
                {
                    stack.push(stack.lpop().remainderOf(stack.lpop()));
                }
                catch (ArithmeticException ex)
                {