classfilewriter.java

主要的怎么样结合java 和 javascript!

            index = putInt16(lineNumberTableAttrIndex, codeAttribute, index);
            int tableAttrLength = 2 + (itsLineNumberTableTop * 4);
            index = putInt32(tableAttrLength, codeAttribute, index);
            index = putInt16(itsLineNumberTableTop, codeAttribute, index);
            for (int i = 0; i < itsLineNumberTableTop; i++) {
                index = putInt32(itsLineNumberTable[i], codeAttribute, index);
            }
        }

        if (itsVarDescriptors != null) {
            int variableTableAttrIndex
                    = itsConstantPool.addUtf8("LocalVariableTable");
            index = putInt16(variableTableAttrIndex, codeAttribute, index);
            int varCount = itsVarDescriptors.size();
            int tableAttrLength = 2 + (varCount * 10);
            index = putInt32(tableAttrLength, codeAttribute, index);
            index = putInt16(varCount, codeAttribute, index);
            for (int i = 0; i < varCount; i++) {
                int[] chunk = (int[])itsVarDescriptors.get(i);
                int nameIndex       = chunk[0];
                int descriptorIndex = chunk[1];
                int startPC         = chunk[2];
                int register        = chunk[3];
                int length = itsCodeBufferTop - startPC;

                index = putInt16(startPC, codeAttribute, index);
                index = putInt16(length, codeAttribute, index);
                index = putInt16(nameIndex, codeAttribute, index);
                index = putInt16(descriptorIndex, codeAttribute, index);
                index = putInt16(register, codeAttribute, index);
            }
        }

        itsCurrentMethod.setCodeAttribute(codeAttribute);

        itsExceptionTable = null;
        itsExceptionTableTop = 0;
        itsLineNumberTableTop = 0;
        itsCodeBufferTop = 0;
        itsCurrentMethod = null;
        itsMaxStack = 0;
        itsStackTop = 0;
        itsLabelTableTop = 0;
        itsFixupTableTop = 0;
        itsVarDescriptors = null;
    }

    /**
     * Add the single-byte opcode to the current method.
     *
     * @param theOpCode the opcode of the bytecode
     */
    public void add(int theOpCode) {
        if (opcodeCount(theOpCode) != 0)
            throw new IllegalArgumentException("Unexpected operands");
        int newStack = itsStackTop + stackChange(theOpCode);
        if (newStack < 0 || Short.MAX_VALUE < newStack) badStack(newStack);
        if (DEBUGCODE)
            System.out.println("Add " + bytecodeStr(theOpCode));
        addToCodeBuffer(theOpCode);
        itsStackTop = (short)newStack;
        if (newStack > itsMaxStack) itsMaxStack = (short)newStack;
        if (DEBUGSTACK) {
            System.out.println("After "+bytecodeStr(theOpCode)
                               +" stack = "+itsStackTop);
        }
    }

    /**
     * Add a single-operand opcode to the current method.
     *
     * @param theOpCode the opcode of the bytecode
     * @param theOperand the operand of the bytecode
     */
    public void add(int theOpCode, int theOperand) {
        if (DEBUGCODE) {
            System.out.println("Add "+bytecodeStr(theOpCode)
                               +", "+Integer.toHexString(theOperand));
        }
        int newStack = itsStackTop + stackChange(theOpCode);
        if (newStack < 0 || Short.MAX_VALUE < newStack) badStack(newStack);

        switch (theOpCode) {
            case ByteCode.GOTO :
                // fallthru...
            case ByteCode.IFEQ :
            case ByteCode.IFNE :
            case ByteCode.IFLT :
            case ByteCode.IFGE :
            case ByteCode.IFGT :
            case ByteCode.IFLE :
            case ByteCode.IF_ICMPEQ :
            case ByteCode.IF_ICMPNE :
            case ByteCode.IF_ICMPLT :
            case ByteCode.IF_ICMPGE :
            case ByteCode.IF_ICMPGT :
            case ByteCode.IF_ICMPLE :
            case ByteCode.IF_ACMPEQ :
            case ByteCode.IF_ACMPNE :
            case ByteCode.JSR :
            case ByteCode.IFNULL :
            case ByteCode.IFNONNULL : {
                    if ((theOperand & 0x80000000) != 0x80000000) {
                        if ((theOperand < 0) || (theOperand > 65535))
                            throw new IllegalArgumentException(
                                "Bad label for branch");
                    }
                    int branchPC = itsCodeBufferTop;
                    addToCodeBuffer(theOpCode);
                    if ((theOperand & 0x80000000) != 0x80000000) {
                            // hard displacement
                        addToCodeInt16(theOperand);
                    }
                    else {  // a label
                        int targetPC = getLabelPC(theOperand);
                        if (DEBUGLABELS) {
                            int theLabel = theOperand & 0x7FFFFFFF;
                            System.out.println("Fixing branch to " +
                                               theLabel + " at " + targetPC +
                                               " from " + branchPC);
                        }
                        if (targetPC != -1) {
                            int offset = targetPC - branchPC;
                            addToCodeInt16(offset);
                        }
                        else {
                            addLabelFixup(theOperand, branchPC + 1);
                            addToCodeInt16(0);
                        }
                    }
                }
                break;

            case ByteCode.BIPUSH :
                if ((byte)theOperand != theOperand)
                    throw new IllegalArgumentException("out of range byte");
                addToCodeBuffer(theOpCode);
                addToCodeBuffer((byte)theOperand);
                break;

            case ByteCode.SIPUSH :
                if ((short)theOperand != theOperand)
                    throw new IllegalArgumentException("out of range short");
                addToCodeBuffer(theOpCode);
                   addToCodeInt16(theOperand);
                break;

            case ByteCode.NEWARRAY :
                if (!(0 <= theOperand && theOperand < 256))
                    throw new IllegalArgumentException("out of range index");
                addToCodeBuffer(theOpCode);
                addToCodeBuffer(theOperand);
                break;

            case ByteCode.GETFIELD :
            case ByteCode.PUTFIELD :
                if (!(0 <= theOperand && theOperand < 65536))
                    throw new IllegalArgumentException("out of range field");
                addToCodeBuffer(theOpCode);
                addToCodeInt16(theOperand);
                break;

            case ByteCode.LDC :
            case ByteCode.LDC_W :
            case ByteCode.LDC2_W :
                if (!(0 <= theOperand && theOperand < 65536))
                    throw new IllegalArgumentException("out of range index");
                if (theOperand >= 256
                    || theOpCode == ByteCode.LDC_W
                    || theOpCode == ByteCode.LDC2_W)
                {
                    if (theOpCode == ByteCode.LDC) {
                        addToCodeBuffer(ByteCode.LDC_W);
                    } else {
                        addToCodeBuffer(theOpCode);
                    }
                    addToCodeInt16(theOperand);
                } else {
                    addToCodeBuffer(theOpCode);
                    addToCodeBuffer(theOperand);
                }
                break;

            case ByteCode.RET :
            case ByteCode.ILOAD :
            case ByteCode.LLOAD :
            case ByteCode.FLOAD :
            case ByteCode.DLOAD :
            case ByteCode.ALOAD :
            case ByteCode.ISTORE :
            case ByteCode.LSTORE :
            case ByteCode.FSTORE :
            case ByteCode.DSTORE :
            case ByteCode.ASTORE :
                if (!(0 <= theOperand && theOperand < 65536))
                    throw new IllegalArgumentException("out of range variable");
                if (theOperand >= 256) {
                    addToCodeBuffer(ByteCode.WIDE);
                    addToCodeBuffer(theOpCode);
                    addToCodeInt16(theOperand);
                }
                else {
                    addToCodeBuffer(theOpCode);
                    addToCodeBuffer(theOperand);
                }
                break;

            default :
                throw new IllegalArgumentException(
                    "Unexpected opcode for 1 operand");
        }

        itsStackTop = (short)newStack;
        if (newStack > itsMaxStack) itsMaxStack = (short)newStack;
        if (DEBUGSTACK) {
            System.out.println("After "+bytecodeStr(theOpCode)
                               +" stack = "+itsStackTop);
        }
    }

    /**
     * Generate the load constant bytecode for the given integer.
     *
     * @param k the constant
     */
    public void addLoadConstant(int k) {
        add(ByteCode.LDC, itsConstantPool.addConstant(k));
    }

    /**
     * Generate the load constant bytecode for the given long.
     *
     * @param k the constant
     */
    public void addLoadConstant(long k) {
        add(ByteCode.LDC2_W, itsConstantPool.addConstant(k));
    }

    /**
     * Generate the load constant bytecode for the given float.
     *
     * @param k the constant
     */
    public void addLoadConstant(float k) {
        add(ByteCode.LDC, itsConstantPool.addConstant(k));
    }

    /**
     * Generate the load constant bytecode for the given double.
     *
     * @param k the constant
     */
    public void addLoadConstant(double k) {
        add(ByteCode.LDC2_W, itsConstantPool.addConstant(k));
    }

    /**
     * Generate the load constant bytecode for the given string.
     *
     * @param k the constant
     */
    public void addLoadConstant(String k) {
        add(ByteCode.LDC, itsConstantPool.addConstant(k));
    }

    /**
     * Add the given two-operand bytecode to the current method.
     *
     * @param theOpCode the opcode of the bytecode
     * @param theOperand1 the first operand of the bytecode
     * @param theOperand2 the second operand of the bytecode
     */
    public void add(int theOpCode, int theOperand1, int theOperand2) {
        if (DEBUGCODE) {
            System.out.println("Add "+bytecodeStr(theOpCode)
                               +", "+Integer.toHexString(theOperand1)
                               +", "+Integer.toHexString(theOperand2));
        }
        int newStack = itsStackTop + stackChange(theOpCode);
        if (newStack < 0 || Short.MAX_VALUE < newStack) badStack(newStack);

        if (theOpCode == ByteCode.IINC) {
            if (!(0 <= theOperand1 && theOperand1 < 65536))
                throw new IllegalArgumentException("out of range variable");
            if (!(0 <= theOperand2 && theOperand2 < 65536))
                throw new IllegalArgumentException("out of range increment");

            if (theOperand1 > 255 || theOperand2 < -128 || theOperand2 > 127) {
                addToCodeBuffer(ByteCode.WIDE);
                addToCodeBuffer(ByteCode.IINC);
                addToCodeInt16(theOperand1);
                addToCodeInt16(theOperand2);
            }
            else {
                addToCodeBuffer(ByteCode.WIDE);
                addToCodeBuffer(ByteCode.IINC);
                addToCodeBuffer(theOperand1);
                addToCodeBuffer(theOperand2);
            }
        }
        else if (theOpCode == ByteCode.MULTIANEWARRAY) {
            if (!(0 <= theOperand1 && theOperand1 < 65536))
                throw new IllegalArgumentException("out of range index");
            if (!(0 <= theOperand2 && theOperand2 < 256))
                throw new IllegalArgumentException("out of range dimensions");

            addToCodeBuffer(ByteCode.MULTIANEWARRAY);
            addToCodeInt16(theOperand1);
            addToCodeBuffer(theOperand2);
        }
        else {
            throw new IllegalArgumentException(
                "Unexpected opcode for 2 operands");
        }
        itsStackTop = (short)newStack;
        if (newStack > itsMaxStack) itsMaxStack = (short)newStack;
        if (DEBUGSTACK) {
            System.out.println("After "+bytecodeStr(theOpCode)
                               +" stack = "+itsStackTop);
        }

    }

    public void add(int theOpCode, String className) {
        if (DEBUGCODE) {
            System.out.println("Add "+bytecodeStr(theOpCode)
                               +", "+className);
        }
        int newStack = itsStackTop + stackChange(theOpCode);
        if (newStack < 0 || Short.MAX_VALUE < newStack) badStack(newStack);
        switch (theOpCode) {
            case ByteCode.NEW :
            case ByteCode.ANEWARRAY :
            case ByteCode.CHECKCAST :
            case ByteCode.INSTANCEOF : {
                short classIndex = itsConstantPool.addClass(className);
                addToCodeBuffer(theOpCode);
                addToCodeInt16(classIndex);
            }
            break;

            default :
                throw new IllegalArgumentException(
                    "bad opcode for class reference");
        }
        itsStackTop = (short)newStack;
        if (newStack > itsMaxStack) itsMaxStack = (short)newStack;
        if (DEBUGSTACK) {
            System.out.println("After "+bytecodeStr(theOpCode)
                               +" stack = "+itsStackTop);
        }
    }


    public void add(int theOpCode, String className, String fieldName,
                    String fieldType)
    {
        if (DEBUGCODE) {
            System.out.println("Add "+bytecodeStr(theOpCode)
                               +", "+className+", "+fieldName+", "+fieldType);
        }
        int newStack = itsStackTop + stackChange(theOpCode);
        char fieldTypeChar = fieldType.charAt(0);
        int fieldSize = (fieldTypeChar == 'J' || fieldTypeChar == 'D')
                        ? 2 : 1;
        switch (theOpCode) {
            case ByteCode.GETFIELD :
            case ByteCode.GETSTATIC :
                newStack += fieldSize;
                break;
            case ByteCode.PUTSTATIC :
            case ByteCode.PUTFIELD :
                newStack -= fieldSize;
                break;