Java 类org.apache.bcel.generic.INSTANCEOF 实例源码

/**
 * Return whether or not the given instruction can throw exceptions.
 *
 * @param handle
 *            the instruction
 * @return true if the instruction can throw an exception, false otherwise
 */
private boolean isPEI(InstructionHandle handle) {
    Instruction ins = handle.getInstruction();

    if (!(ins instanceof ExceptionThrower))
        return false;

    if (ins instanceof NEW)
        return false;
    // if (ins instanceof ATHROW) return false;
    if (ins instanceof GETSTATIC)
        return false;
    if (ins instanceof PUTSTATIC)
        return false;
    if (ins instanceof ReturnInstruction)
        return false;
    if (ins instanceof INSTANCEOF)
        return false;
    if (ins instanceof MONITOREXIT)
        return false;
    if (ins instanceof LDC)
        return false;
    return true;

}

/**
 * Return whether or not the given instruction can throw exceptions.
 *
 * @param handle
 *            the instruction
 * @return true if the instruction can throw an exception, false otherwise
 */
private boolean isPEI(InstructionHandle handle) {
    Instruction ins = handle.getInstruction();

    if (!(ins instanceof ExceptionThrower))
        return false;

    if (ins instanceof NEW)
        return false;
    // if (ins instanceof ATHROW) return false;
    if (ins instanceof GETSTATIC)
        return false;
    if (ins instanceof PUTSTATIC)
        return false;
    if (ins instanceof ReturnInstruction)
        return false;
    if (ins instanceof INSTANCEOF)
        return false;
    if (ins instanceof MONITOREXIT)
        return false;
    if (ins instanceof LDC)
        return false;
    return true;

}

InstructionHandle insertTypecheckCode(MethodGen m, InstructionList il,
    InstructionHandle pos, int spawnId, int exceptionPos) {
    ArrayList<CodeExceptionGen> catches = mtab.getCatchTypes(m, spawnId);

    InstructionHandle[] jumpTargets = new InstructionHandle[catches.size() + 1];

    BranchHandle[] jumps = new BranchHandle[catches.size()];

    for (int i = 0; i < catches.size(); i++) {
        CodeExceptionGen e = catches.get(i);
        ObjectType type = e.getCatchType();
        InstructionHandle catchTarget = e.getHandlerPC();

        jumpTargets[i] = il.insert(pos, new ALOAD(exceptionPos));
        il.insert(pos, new INSTANCEOF(cpg.addClass(type)));
        il.insert(pos, new BIPUSH((byte) 1));
        jumps[i] = il.insert(pos, new IF_ICMPNE(null));
        il.insert(pos, new ALOAD(exceptionPos));
        il.insert(pos, ins_f.createCheckCast(type));
        il.insert(pos, new GOTO(catchTarget));
    }

    InstructionHandle t = il.insert(pos, new ALOAD(exceptionPos));
    il.insert(pos, new ATHROW());

    jumpTargets[catches.size()] = t;

    for (int i = 0; i < catches.size(); i++) {
        jumps[i].setTarget(jumpTargets[i + 1]);
    }

    return pos;
}

public void visitINSTANCEOF(INSTANCEOF i) {
    Type t = i.getType(poolGen);
    log.log("         instr(instanceof)=" + t, Project.MSG_DEBUG);
    String type = t.toString();

    design.checkClass(type);
}

/**
 * Inject common exception catch blocks
 */
public void injectCommonExceptionCatchBlock(InstructionList il, MethodGen method, int variableIndex) {
    il.append(new INSTANCEOF(constantsPool.addClass(new ObjectType("java.lang.RuntimeException"))));
    BranchInstruction b1 = InstructionFactory.createBranchInstruction(Constants.IFEQ, null);
    il.append(b1);
    il.append(InstructionFactory.createLoad(Type.OBJECT, variableIndex));
    il.append(factory.createCheckCast(new ObjectType("java.lang.RuntimeException")));
    il.append(InstructionConstants.ATHROW);
    InstructionHandle ih1 = il.append(InstructionFactory.createLoad(Type.OBJECT, variableIndex));
    il.append(new INSTANCEOF(constantsPool.addClass(new ObjectType("java.lang.Error"))));
    BranchInstruction b2 = InstructionFactory.createBranchInstruction(Constants.IFEQ, null);
    il.append(b2);
    il.append(InstructionFactory.createLoad(Type.OBJECT, variableIndex));
    il.append(factory.createCheckCast(new ObjectType("java.lang.Error")));
    il.append(InstructionConstants.ATHROW);
    InstructionHandle ih2 = il.append(InstructionFactory.createLoad(Type.OBJECT, variableIndex));
    il.append(factory.createInvoke("java.lang.Throwable", "printStackTrace", Type.VOID, Type.NO_ARGS, Constants.INVOKEVIRTUAL));
    il.append(factory.createNew("org.codehaus.jremoting.client.InvocationException"));
    il.append(InstructionConstants.DUP);
    il.append(factory.createNew("java.lang.StringBuffer"));
    il.append(InstructionConstants.DUP);
    il.append(new PUSH(constantsPool, "Should never get here: "));
    il.append(factory.createInvoke("java.lang.StringBuffer", "<init>", Type.VOID, new Type[]{Type.STRING}, Constants.INVOKESPECIAL));
    il.append(InstructionFactory.createLoad(Type.OBJECT, variableIndex));
    il.append(factory.createInvoke("java.lang.Throwable", "getMessage", Type.STRING, Type.NO_ARGS, Constants.INVOKEVIRTUAL));
    il.append(factory.createInvoke("java.lang.StringBuffer", "append", Type.STRINGBUFFER, new Type[]{Type.STRING}, Constants.INVOKEVIRTUAL));
    il.append(factory.createInvoke("java.lang.StringBuffer", "toString", Type.STRING, Type.NO_ARGS, Constants.INVOKEVIRTUAL));
    il.append(factory.createInvoke("org.codehaus.jremoting.client.InvocationException", "<init>", Type.VOID, new Type[]{Type.STRING}, Constants.INVOKESPECIAL));
    il.append(InstructionConstants.ATHROW);

    b1.setTarget(ih1);
    b2.setTarget(ih2);

}

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitINSTANCEOF(INSTANCEOF o){
    indexValid(o, o.getIndex());
    Constant c = cpg.getConstant(o.getIndex());
    if (!   (c instanceof ConstantClass)){
        constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
    }
}

public boolean prescreen(ClassContext classContext, Method method) {
    BitSet bytecodeSet = classContext.getBytecodeSet(method);
    return bytecodeSet != null && (bytecodeSet.get(Constants.CHECKCAST) || bytecodeSet.get(Constants.INSTANCEOF));
}

public boolean prescreen(ClassContext classContext, Method method) {
    BitSet bytecodeSet = classContext.getBytecodeSet(method);
    return bytecodeSet != null && (bytecodeSet.get(Constants.CHECKCAST) || bytecodeSet.get(Constants.INSTANCEOF));
}

public void visitINSTANCEOF( INSTANCEOF i ) {
    Type type = i.getType(_cp);
    _out.println("il.append(new INSTANCEOF(_cp.addClass(" + BCELifier.printType(type) + ")));");
}