checkmethodadapter.java

asm的源码包 并且包含英文的文档

                desc,
                visible));
    }

    public void visitAttribute(final Attribute attr) {
        checkEndMethod();
        if (attr == null) {
            throw new IllegalArgumentException("Invalid attribute (must not be null)");
        }
        mv.visitAttribute(attr);
    }

    public void visitCode() {
        startCode = true;
        mv.visitCode();
    }

    public void visitFrame(
        final int type,
        final int nLocal,
        final Object[] local,
        final int nStack,
        final Object[] stack)
    {
        int mLocal;
        int mStack;
        switch (type) {
            case Opcodes.F_NEW:
            case Opcodes.F_FULL:
                mLocal = Integer.MAX_VALUE;
                mStack = Integer.MAX_VALUE;
                break;

            case Opcodes.F_SAME:
                mLocal = 0;
                mStack = 0;
                break;

            case Opcodes.F_SAME1:
                mLocal = 0;
                mStack = 1;
                break;

            case Opcodes.F_APPEND:
            case Opcodes.F_CHOP:
                mLocal = 3;
                mStack = 0;
                break;

            default:
                throw new IllegalArgumentException("Invalid frame type " + type);
        }

        if (nLocal > mLocal) {
            throw new IllegalArgumentException("Invalid nLocal=" + nLocal
                    + " for frame type " + type);
        }
        if (nStack > mStack) {
            throw new IllegalArgumentException("Invalid nStack=" + nStack
                    + " for frame type " + type);
        }

        if (nLocal > 0 && (local == null || local.length < nLocal)) {
            throw new IllegalArgumentException("Array local[] is shorter than nLocal");
        }
        if (nStack > 0 && (stack == null || stack.length < nStack)) {
            throw new IllegalArgumentException("Array stack[] is shorter than nStack");
        }

        /*
         * TODO check values of the individual frames. Primitive types are
         * represented by Opcodes.TOP, Opcodes.INTEGER, Opcodes.FLOAT,
         * Opcodes.LONG, Opcodes.DOUBLE,Opcodes.NULL or
         * Opcodes.UNINITIALIZED_THIS (long and double are represented by a
         * single element). Reference types are represented by String objects,
         * and uninitialized types by Label objects (this label designates the
         * NEW instruction that created this uninitialized value).
         */

        mv.visitFrame(type, nLocal, local, nStack, stack);
    }

    public void visitInsn(final int opcode) {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 0);
        mv.visitInsn(opcode);
    }

    public void visitIntInsn(final int opcode, final int operand) {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 1);
        switch (opcode) {
            case Opcodes.BIPUSH:
                checkSignedByte(operand, "Invalid operand");
                break;
            case Opcodes.SIPUSH:
                checkSignedShort(operand, "Invalid operand");
                break;
            // case Constants.NEWARRAY:
            default:
                if (operand < Opcodes.T_BOOLEAN || operand > Opcodes.T_LONG) {
                    throw new IllegalArgumentException("Invalid operand (must be an array type code T_...): "
                            + operand);
                }
        }
        mv.visitIntInsn(opcode, operand);
    }

    public void visitVarInsn(final int opcode, final int var) {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 2);
        checkUnsignedShort(var, "Invalid variable index");
        mv.visitVarInsn(opcode, var);
    }

    public void visitTypeInsn(final int opcode, final String desc) {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 3);
        if (desc != null && desc.length() > 0 && desc.charAt(0) == '[') {
            checkDesc(desc, false);
        } else {
            checkInternalName(desc, "type");
        }
        if (opcode == Opcodes.NEW && desc.charAt(0) == '[') {
            throw new IllegalArgumentException("NEW cannot be used to create arrays: "
                    + desc);
        }
        mv.visitTypeInsn(opcode, desc);
    }

    public void visitFieldInsn(
        final int opcode,
        final String owner,
        final String name,
        final String desc)
    {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 4);
        checkInternalName(owner, "owner");
        checkIdentifier(name, "name");
        checkDesc(desc, false);
        mv.visitFieldInsn(opcode, owner, name, desc);
    }

    public void visitMethodInsn(
        final int opcode,
        final String owner,
        final String name,
        final String desc)
    {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 5);
        checkMethodIdentifier(name, "name");
        if (!name.equals("clone")) {
            // In JDK1.5, clone method can be called on array class descriptors
            checkInternalName(owner, "owner");
        }
        checkMethodDesc(desc);
        mv.visitMethodInsn(opcode, owner, name, desc);
    }

    public void visitJumpInsn(final int opcode, final Label label) {
        checkStartCode();
        checkEndCode();
        checkOpcode(opcode, 6);
        checkLabel(label, false, "label");
        mv.visitJumpInsn(opcode, label);
    }

    public void visitLabel(final Label label) {
        checkStartCode();
        checkEndCode();
        checkLabel(label, false, "label");
        if (labels.get(label) != null) {
            throw new IllegalArgumentException("Already visited label");
        } else {
            labels.put(label, new Integer(labels.size()));
        }
        mv.visitLabel(label);
    }

    public void visitLdcInsn(final Object cst) {
        checkStartCode();
        checkEndCode();
        if (!(cst instanceof Type)) {
            checkConstant(cst);
        }
        mv.visitLdcInsn(cst);
    }

    public void visitIincInsn(final int var, final int increment) {
        checkStartCode();
        checkEndCode();
        checkUnsignedShort(var, "Invalid variable index");
        checkSignedShort(increment, "Invalid increment");
        mv.visitIincInsn(var, increment);
    }

    public void visitTableSwitchInsn(
        final int min,
        final int max,
        final Label dflt,
        final Label labels[])
    {
        checkStartCode();
        checkEndCode();
        if (max < min) {
            throw new IllegalArgumentException("Max = " + max
                    + " must be greater than or equal to min = " + min);
        }
        checkLabel(dflt, false, "default label");
        if (labels == null || labels.length != max - min + 1) {
            throw new IllegalArgumentException("There must be max - min + 1 labels");
        }
        for (int i = 0; i < labels.length; ++i) {
            checkLabel(labels[i], false, "label at index " + i);
        }
        mv.visitTableSwitchInsn(min, max, dflt, labels);
    }

    public void visitLookupSwitchInsn(
        final Label dflt,
        final int keys[],
        final Label labels[])
    {
        checkEndCode();
        checkStartCode();
        checkLabel(dflt, false, "default label");
        if (keys == null || labels == null || keys.length != labels.length) {
            throw new IllegalArgumentException("There must be the same number of keys and labels");
        }
        for (int i = 0; i < labels.length; ++i) {
            checkLabel(labels[i], false, "label at index " + i);
        }
        mv.visitLookupSwitchInsn(dflt, keys, labels);
    }

    public void visitMultiANewArrayInsn(final String desc, final int dims) {
        checkStartCode();
        checkEndCode();
        checkDesc(desc, false);
        if (desc.charAt(0) != '[') {
            throw new IllegalArgumentException("Invalid descriptor (must be an array type descriptor): "
                    + desc);
        }
        if (dims < 1) {
            throw new IllegalArgumentException("Invalid dimensions (must be greater than 0): "
                    + dims);
        }
        if (dims > desc.lastIndexOf('[') + 1) {
            throw new IllegalArgumentException("Invalid dimensions (must not be greater than dims(desc)): "
                    + dims);
        }
        mv.visitMultiANewArrayInsn(desc, dims);
    }

    public void visitTryCatchBlock(
        final Label start,
        final Label end,
        final Label handler,
        final String type)
    {
        checkStartCode();
        checkEndCode();
        if (type != null) {
            checkInternalName(type, "type");
        }
        mv.visitTryCatchBlock(start, end, handler, type);
    }

    public void visitLocalVariable(
        final String name,
        final String desc,
        final String signature,
        final Label start,
        final Label end,
        final int index)
    {
        checkStartCode();
        checkEndCode();
        checkIdentifier(name, "name");
        checkDesc(desc, false);
        checkLabel(start, true, "start label");
        checkLabel(end, true, "end label");
        checkUnsignedShort(index, "Invalid variable index");
        int s = ((Integer) labels.get(start)).intValue();
        int e = ((Integer) labels.get(end)).intValue();
        if (e < s) {
            throw new IllegalArgumentException("Invalid start and end labels (end must be greater than start)");
        }
        mv.visitLocalVariable(name, desc, signature, start, end, index);
    }

    public void visitLineNumber(final int line, final Label start) {
        checkStartCode();
        checkEndCode();
        checkUnsignedShort(line, "Invalid line number");
        checkLabel(start, true, "start label");
        mv.visitLineNumber(line, start);
    }

    public void visitMaxs(final int maxStack, final int maxLocals) {
        checkStartCode();
        checkEndCode();
        endCode = true;
        checkUnsignedShort(maxStack, "Invalid max stack");
        checkUnsignedShort(maxLocals, "Invalid max locals");
        mv.visitMaxs(maxStack, maxLocals);
    }

    public void visitEnd() {
        checkEndMethod();
        endMethod = true;
        mv.visitEnd();
    }

    // -------------------------------------------------------------------------

    /**
     * Checks that the visitCode method has been called.
     */
    void checkStartCode() {
        if (!startCode) {
            throw new IllegalStateException("Cannot visit instructions before visitCode has been called.");
        }
    }

    /**
     * Checks that the visitMaxs method has not been called.
     */