| /*** |
| * 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 com.google.gwt.dev.asm; |
| |
| /** |
| * A non standard class, field, method or code attribute. |
| * |
| * @author Eric Bruneton |
| * @author Eugene Kuleshov |
| */ |
| public class Attribute { |
| |
| /** |
| * The type of this attribute. |
| */ |
| public final String type; |
| |
| /** |
| * The raw value of this attribute, used only for unknown attributes. |
| */ |
| byte[] value; |
| |
| /** |
| * The next attribute in this attribute list. May be <tt>null</tt>. |
| */ |
| Attribute next; |
| |
| /** |
| * Constructs a new empty attribute. |
| * |
| * @param type the type of the attribute. |
| */ |
| protected Attribute(final String type) { |
| this.type = type; |
| } |
| |
| /** |
| * Returns <tt>true</tt> if this type of attribute is unknown. The default |
| * implementation of this method always returns <tt>true</tt>. |
| * |
| * @return <tt>true</tt> if this type of attribute is unknown. |
| */ |
| public boolean isUnknown() { |
| return true; |
| } |
| |
| /** |
| * Returns <tt>true</tt> if this type of attribute is a code attribute. |
| * |
| * @return <tt>true</tt> if this type of attribute is a code attribute. |
| */ |
| public boolean isCodeAttribute() { |
| return false; |
| } |
| |
| /** |
| * Returns the labels corresponding to this attribute. |
| * |
| * @return the labels corresponding to this attribute, or <tt>null</tt> if |
| * this attribute is not a code attribute that contains labels. |
| */ |
| protected Label[] getLabels() { |
| return null; |
| } |
| |
| /** |
| * Reads a {@link #type type} attribute. This method must return a <i>new</i> |
| * {@link Attribute} object, of type {@link #type type}, corresponding to |
| * the <tt>len</tt> bytes starting at the given offset, in the given class |
| * reader. |
| * |
| * @param cr the class that contains the attribute to be read. |
| * @param off index of the first byte of the attribute's content in {@link |
| * ClassReader#b cr.b}. The 6 attribute header bytes, containing the |
| * type and the length of the attribute, are not taken into account |
| * here. |
| * @param len the length of the attribute's content. |
| * @param buf buffer to be used to call |
| * {@link ClassReader#readUTF8 readUTF8}, |
| * {@link ClassReader#readClass(int,char[]) readClass} or |
| * {@link ClassReader#readConst readConst}. |
| * @param codeOff index of the first byte of code's attribute content in |
| * {@link ClassReader#b cr.b}, or -1 if the attribute to be read is |
| * not a code attribute. The 6 attribute header bytes, containing the |
| * type and the length of the attribute, are not taken into account |
| * here. |
| * @param labels the labels of the method's code, or <tt>null</tt> if the |
| * attribute to be read is not a code attribute. |
| * @return a <i>new</i> {@link Attribute} object corresponding to the given |
| * bytes. |
| */ |
| protected Attribute read( |
| final ClassReader cr, |
| final int off, |
| final int len, |
| final char[] buf, |
| final int codeOff, |
| final Label[] labels) |
| { |
| Attribute attr = new Attribute(type); |
| attr.value = new byte[len]; |
| System.arraycopy(cr.b, off, attr.value, 0, len); |
| return attr; |
| } |
| |
| /** |
| * Returns the byte array form of this attribute. |
| * |
| * @param cw the class to which this attribute must be added. This parameter |
| * can be used to add to the constant pool of this class the items |
| * that corresponds to this attribute. |
| * @param code the bytecode of the method corresponding to this code |
| * attribute, or <tt>null</tt> if this attribute is not a code |
| * attributes. |
| * @param len the length of the bytecode of the method corresponding to this |
| * code attribute, or <tt>null</tt> if this attribute is not a code |
| * attribute. |
| * @param maxStack the maximum stack size of the method corresponding to |
| * this code attribute, or -1 if this attribute is not a code |
| * attribute. |
| * @param maxLocals the maximum number of local variables of the method |
| * corresponding to this code attribute, or -1 if this attribute is |
| * not a code attribute. |
| * @return the byte array form of this attribute. |
| */ |
| protected ByteVector write( |
| final ClassWriter cw, |
| final byte[] code, |
| final int len, |
| final int maxStack, |
| final int maxLocals) |
| { |
| ByteVector v = new ByteVector(); |
| v.data = value; |
| v.length = value.length; |
| return v; |
| } |
| |
| /** |
| * Returns the length of the attribute list that begins with this attribute. |
| * |
| * @return the length of the attribute list that begins with this attribute. |
| */ |
| final int getCount() { |
| int count = 0; |
| Attribute attr = this; |
| while (attr != null) { |
| count += 1; |
| attr = attr.next; |
| } |
| return count; |
| } |
| |
| /** |
| * Returns the size of all the attributes in this attribute list. |
| * |
| * @param cw the class writer to be used to convert the attributes into byte |
| * arrays, with the {@link #write write} method. |
| * @param code the bytecode of the method corresponding to these code |
| * attributes, or <tt>null</tt> if these attributes are not code |
| * attributes. |
| * @param len the length of the bytecode of the method corresponding to |
| * these code attributes, or <tt>null</tt> if these attributes are |
| * not code attributes. |
| * @param maxStack the maximum stack size of the method corresponding to |
| * these code attributes, or -1 if these attributes are not code |
| * attributes. |
| * @param maxLocals the maximum number of local variables of the method |
| * corresponding to these code attributes, or -1 if these attributes |
| * are not code attributes. |
| * @return the size of all the attributes in this attribute list. This size |
| * includes the size of the attribute headers. |
| */ |
| final int getSize( |
| final ClassWriter cw, |
| final byte[] code, |
| final int len, |
| final int maxStack, |
| final int maxLocals) |
| { |
| Attribute attr = this; |
| int size = 0; |
| while (attr != null) { |
| cw.newUTF8(attr.type); |
| size += attr.write(cw, code, len, maxStack, maxLocals).length + 6; |
| attr = attr.next; |
| } |
| return size; |
| } |
| |
| /** |
| * Writes all the attributes of this attribute list in the given byte |
| * vector. |
| * |
| * @param cw the class writer to be used to convert the attributes into byte |
| * arrays, with the {@link #write write} method. |
| * @param code the bytecode of the method corresponding to these code |
| * attributes, or <tt>null</tt> if these attributes are not code |
| * attributes. |
| * @param len the length of the bytecode of the method corresponding to |
| * these code attributes, or <tt>null</tt> if these attributes are |
| * not code attributes. |
| * @param maxStack the maximum stack size of the method corresponding to |
| * these code attributes, or -1 if these attributes are not code |
| * attributes. |
| * @param maxLocals the maximum number of local variables of the method |
| * corresponding to these code attributes, or -1 if these attributes |
| * are not code attributes. |
| * @param out where the attributes must be written. |
| */ |
| final void put( |
| final ClassWriter cw, |
| final byte[] code, |
| final int len, |
| final int maxStack, |
| final int maxLocals, |
| final ByteVector out) |
| { |
| Attribute attr = this; |
| while (attr != null) { |
| ByteVector b = attr.write(cw, code, len, maxStack, maxLocals); |
| out.putShort(cw.newUTF8(attr.type)).putInt(b.length); |
| out.putByteArray(b.data, 0, b.length); |
| attr = attr.next; |
| } |
| } |
| } |