FieldWriter.java

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 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 org.botnode.asm;

/**
 * An FieldVisitor that generates Java fields in bytecode form.
 *
 * @author Eric Bruneton
 */
final class FieldWriter {

    FieldWriter next;

    private final ClassWriter cw;

    private final int access;

    private final int name;

    /**
     * The index of the constant pool item that contains the descriptor of this
     * field.
     */
    private final int desc;

    /**
     * The index of the constant pool item that contains the signature of this
     * field.
     */
    private int signature;

    /**
     * The index of the constant pool item that contains the constant value of
     * this field.
     */
    private int value;

    /**
     * The non standard attributes of this field. May be <tt>null</tt>.
     */
    private Attribute attrs;


    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------

    /**
     * Constructs a new FieldWriter.
     */
    FieldWriter(final ClassWriter cw, final int access, final String name, final String desc, final String signature,
            final Object value) {
        if (cw.firstField == null) {
            cw.firstField = this;
        } else {
            cw.lastField.next = this;
        }

        cw.lastField = this;
        this.cw = cw;
        this.access = access;
        this.name = cw.newUTF8(name);
        this.desc = cw.newUTF8(desc);

        if (value != null) {
            this.value = cw.newConstItem(value).index;
        }
    }

    // ------------------------------------------------------------------------
    // Utility methods
    // ------------------------------------------------------------------------

    /**
     * Returns the size of this field.
     *
     * @return the size of this field.
     */
    int getSize() {
        int size = 8;
        if (value != 0) {
            cw.newUTF8("ConstantValue");
            size += 8;
        }
        if ((access & Opcodes.ACC_SYNTHETIC) != 0 && (cw.version & 0xffff) < Opcodes.V1_5) {
            cw.newUTF8("Synthetic");
            size += 6;
        }
        if ((access & Opcodes.ACC_DEPRECATED) != 0) {
            cw.newUTF8("Deprecated");
            size += 6;
        }               
        if (attrs != null) {
            size += attrs.getSize(cw, null, 0, -1, -1);
        }
        return size;
    }

    /**
     * Puts the content of this field into the given byte vector.
     *
     * @param out where the content of this field must be put.
     */
    void put(final ByteVector out) {

        // Write that we are writing a field:
        out.putShort(access).putShort(name).putShort(desc);

        //***************************************
        // Prepare the field.
        //***************************************
        int attributeCount = 0;

        if (value != 0) {
            ++attributeCount;
        }
        if ((access & Opcodes.ACC_SYNTHETIC) != 0 && (cw.version & 0xffff) < Opcodes.V1_5) {
            ++attributeCount;
        }
        if ((access & Opcodes.ACC_DEPRECATED) != 0) {
            ++attributeCount;
        }

        if (attrs != null) {
            attributeCount += attrs.getCount();
        }
        // Write the constant value.
        out.putShort(attributeCount);
        if (value != 0) {
            out.putShort(cw.newUTF8("ConstantValue"));
            out.putInt(2).putShort(value);
        }
        if ((access & Opcodes.ACC_SYNTHETIC) != 0 && (cw.version & 0xffff) < Opcodes.V1_5) {
            out.putShort(cw.newUTF8("Synthetic")).putInt(0);
        }
        if (attrs != null) {
            attrs.put(cw, null, 0, -1, -1, out);
        }
    }
} // End of Class