mockit.external.asm.TypePath Maven / Gradle / Ivy

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2013 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 mockit.external.asm;

/**
 * The path to a type argument, wildcard bound, array element type, or static
 * inner type within an enclosing type.
 *
 * @author Eric Bruneton
 */
final class TypePath {

    /**
     * A type path step that steps into the element type of an array type. See
     * {@link #getStep getStep}.
     */
    static final int ARRAY_ELEMENT = 0;

    /**
     * A type path step that steps into the nested type of a class type. See
     * {@link #getStep getStep}.
     */
    static final int INNER_TYPE = 1;

    /**
     * A type path step that steps into the bound of a wildcard type. See
     * {@link #getStep getStep}.
     */
    static final int WILDCARD_BOUND = 2;

    /**
     * A type path step that steps into a type argument of a generic type. See
     * {@link #getStep getStep}.
     */
    static final int TYPE_ARGUMENT = 3;

    /**
     * The byte array where the path is stored, in Java class file format.
     */
    byte[] b;

    /**
     * The offset of the first byte of the type path in 'b'.
     */
    int offset;

    /**
     * Creates a new type path.
     *
     * @param b
     *            the byte array containing the type path in Java class file
     *            format.
     * @param offset
     *            the offset of the first byte of the type path in 'b'.
     */
    TypePath(byte[] b, int offset) {
        this.b = b;
        this.offset = offset;
    }

    /**
     * Returns the length of this path.
     *
     * @return the length of this path.
     */
    int getLength() {
        return b[offset];
    }

    /**
     * Returns the value of the given step of this path.
     *
     * @param index
     *            an index between 0 and {@link #getLength()}, exclusive.
     * @return {@link #ARRAY_ELEMENT ARRAY_ELEMENT}, {@link #INNER_TYPE
     *         INNER_TYPE}, {@link #WILDCARD_BOUND WILDCARD_BOUND}, or
     *         {@link #TYPE_ARGUMENT TYPE_ARGUMENT}.
     */
    int getStep(int index) {
        return b[offset + 2 * index + 1];
    }

    /**
     * Returns the index of the type argument that the given step is stepping
     * into. This method should only be used for steps whose value is
     * {@link #TYPE_ARGUMENT TYPE_ARGUMENT}.
     *
     * @param index
     *            an index between 0 and {@link #getLength()}, exclusive.
     * @return the index of the type argument that the given step is stepping
     *         into.
     */
    int getStepArgument(int index) {
        return b[offset + 2 * index + 2];
    }

    /**
     * Returns a string representation of this type path. {@link #ARRAY_ELEMENT
     * ARRAY_ELEMENT} steps are represented with '[', {@link #INNER_TYPE
     * INNER_TYPE} steps with '.', {@link #WILDCARD_BOUND WILDCARD_BOUND} steps
     * with '*' and {@link #TYPE_ARGUMENT TYPE_ARGUMENT} steps with their type
     * argument index in decimal form.
     */
    @Override
    public String toString() {
        int length = getLength();
        StringBuilder result = new StringBuilder(length * 2);
        for (int i = 0; i < length; ++i) {
            switch (getStep(i)) {
            case ARRAY_ELEMENT:
                result.append('[');
                break;
            case INNER_TYPE:
                result.append('.');
                break;
            case WILDCARD_BOUND:
                result.append('*');
                break;
            case TYPE_ARGUMENT:
                result.append(getStepArgument(i));
                break;
            default:
                result.append('_');
            }
        }
        return result.toString();
    }
}