1012 lines
34 KiB
Java
1012 lines
34 KiB
Java
/***
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* ASM: a very small and fast Java bytecode manipulation framework
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* Copyright (c) 2000,2002,2003 INRIA, France Telecom
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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* THE POSSIBILITY OF SUCH DAMAGE.
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*
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* Contact: Eric.Bruneton@rd.francetelecom.com
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*
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* Author: Eric Bruneton
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*/
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package org.objectweb.asm;
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import java.io.InputStream;
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import java.io.IOException;
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/**
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* A Java class parser to make a {@link ClassVisitor ClassVisitor} visit an
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* existing class. This class parses a byte array conforming to the Java class
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* file format and calls the appropriate visit methods of a given class visitor
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* for each field, method and bytecode instruction encountered.
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*/
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public class ClassReader {
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/**
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* The class to be parsed. <i>The content of this array must not be
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* modified. This field is intended for {@link Attribute} sub classes, and is
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* normally not needed by class generators or adapters.</i>
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*/
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public final byte[] b;
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/**
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* The start index of each constant pool item in {@link #b b}, plus one. The
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* one byte offset skips the constant pool item tag that indicates its type.
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*/
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private int[] items;
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/**
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* The String objects corresponding to the CONSTANT_Utf8 items. This cache
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* avoids multiple parsing of a given CONSTANT_Utf8 constant pool item, which
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* GREATLY improves performances (by a factor 2 to 3). This caching strategy
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* could be extended to all constant pool items, but its benefit would not be
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* so great for these items (because they are much less expensive to parse
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* than CONSTANT_Utf8 items).
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*/
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private String[] strings;
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/**
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* Maximum length of the strings contained in the constant pool of the class.
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*/
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private int maxStringLength;
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/**
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* Start index of the class header information (access, name...) in {@link #b
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* b}.
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*/
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private int header;
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// --------------------------------------------------------------------------
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// Constructors
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// --------------------------------------------------------------------------
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/**
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* Constructs a new {@link ClassReader ClassReader} object.
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*
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* @param b the bytecode of the class to be read.
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*/
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public ClassReader (final byte[] b) {
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this(b, 0, b.length);
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}
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/**
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* Constructs a new {@link ClassReader ClassReader} object.
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*
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* @param b the bytecode of the class to be read.
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* @param off the start offset of the class data.
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* @param len the length of the class data.
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*/
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public ClassReader (final byte[] b, final int off, final int len) {
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this.b = b;
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// parses the constant pool
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items = new int[readUnsignedShort(off + 8)];
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strings = new String[items.length];
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int max = 0;
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int index = off + 10;
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for (int i = 1; i < items.length; ++i) {
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items[i] = index + 1;
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int tag = b[index];
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int size;
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switch (tag) {
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case ClassWriter.FIELD:
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case ClassWriter.METH:
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case ClassWriter.IMETH:
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case ClassWriter.INT:
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case ClassWriter.FLOAT:
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case ClassWriter.NAME_TYPE:
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size = 5;
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break;
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case ClassWriter.LONG:
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case ClassWriter.DOUBLE:
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size = 9;
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++i;
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break;
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case ClassWriter.UTF8:
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size = 3 + readUnsignedShort(index + 1);
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max = (size > max ? size : max);
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break;
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//case ClassWriter.CLASS:
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//case ClassWriter.STR:
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default:
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size = 3;
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break;
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}
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index += size;
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}
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maxStringLength = max;
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// the class header information starts just after the constant pool
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header = index;
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}
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/**
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* Constructs a new {@link ClassReader ClassReader} object.
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*
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* @param is an input stream from which to read the class.
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* @throws IOException if a problem occurs during reading.
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*/
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public ClassReader (final InputStream is) throws IOException {
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this(readClass(is));
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}
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/**
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* Constructs a new {@link ClassReader ClassReader} object.
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*
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* @param name the fully qualified name of the class to be read.
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* @throws IOException if an exception occurs during reading.
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*/
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public ClassReader (final String name) throws IOException {
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this((ClassReader.class.getClassLoader() == null
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? ClassLoader.getSystemClassLoader()
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: ClassReader.class.getClassLoader())
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.getSystemResourceAsStream(name.replace('.','/') + ".class"));
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}
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/**
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* Reads the bytecode of a class.
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*
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* @param is an input stream from which to read the class.
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* @return the bytecode read from the given input stream.
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* @throws IOException if a problem occurs during reading.
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*/
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private static byte[] readClass (final InputStream is) throws IOException {
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if (is == null) {
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throw new IOException("Class not found");
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}
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byte[] b = new byte[is.available()];
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int len = 0;
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while (true) {
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int n = is.read(b, len, b.length - len);
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if (n == -1) {
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if (len < b.length) {
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byte[] c = new byte[len];
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System.arraycopy(b, 0, c, 0, len);
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b = c;
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}
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return b;
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} else {
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len += n;
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if (len == b.length) {
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byte[] c = new byte[b.length + 1000];
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System.arraycopy(b, 0, c, 0, len);
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b = c;
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}
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}
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}
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}
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// --------------------------------------------------------------------------
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// Public methods
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// --------------------------------------------------------------------------
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/**
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* Returns the major and minor version numbers of this class.
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*
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* @return the <tt>int</tt> array { major version, minor version }
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*/
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public int[] getVersion () {
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return new int[] { readShort(6), readShort(4) };
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}
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/**
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* Makes the given visitor visit the Java class of this {@link ClassReader
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* ClassReader}. This class is the one specified in the constructor (see
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* {@link #ClassReader ClassReader}).
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*
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* @param classVisitor the visitor that must visit this class.
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* @param skipDebug <tt>true</tt> if the debug information of the class must
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* not be visited. In this case the {@link CodeVisitor#visitLocalVariable
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* visitLocalVariable} and {@link CodeVisitor#visitLineNumber
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* visitLineNumber} methods will not be called.
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*/
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public void accept (
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final ClassVisitor classVisitor,
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final boolean skipDebug)
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{
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accept(classVisitor, new Attribute[0], skipDebug);
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}
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/**
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* Makes the given visitor visit the Java class of this {@link ClassReader
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* ClassReader}. This class is the one specified in the constructor (see
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* {@link #ClassReader ClassReader}).
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*
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* @param classVisitor the visitor that must visit this class.
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* @param attrs prototypes of the attributes that must be parsed during the
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* visit of the class. Any attribute whose type is not equal to the type
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* of one the prototypes will be ignored.
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* @param skipDebug <tt>true</tt> if the debug information of the class must
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* not be visited. In this case the {@link CodeVisitor#visitLocalVariable
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* visitLocalVariable} and {@link CodeVisitor#visitLineNumber
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* visitLineNumber} methods will not be called.
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*/
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public void accept (
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final ClassVisitor classVisitor,
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final Attribute[] attrs,
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final boolean skipDebug)
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{
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byte[] b = this.b; // the bytecode array
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char[] c = new char[maxStringLength]; // buffer used to read strings
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int i, j, k; // loop variables
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int u, v, w; // indexes in b
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Attribute attr;
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// visits the header
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u = header;
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int access = readUnsignedShort(u);
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String className = readClass(u + 2, c);
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v = items[readUnsignedShort(u + 4)];
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String superClassName = v == 0 ? null : readUTF8(v, c);
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String[] implementedItfs = new String[readUnsignedShort(u + 6)];
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String sourceFile = null;
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Attribute clattrs = null;
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w = 0;
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u += 8;
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for (i = 0; i < implementedItfs.length; ++i) {
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implementedItfs[i] = readClass(u, c); u += 2;
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}
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// skips fields and methods
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v = u;
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i = readUnsignedShort(v); v += 2;
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for ( ; i > 0; --i) {
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j = readUnsignedShort(v + 6);
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v += 8;
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for ( ; j > 0; --j) {
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v += 6 + readInt(v + 2);
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}
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}
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i = readUnsignedShort(v); v += 2;
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for ( ; i > 0; --i) {
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j = readUnsignedShort(v + 6);
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v += 8;
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for ( ; j > 0; --j) {
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v += 6 + readInt(v + 2);
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}
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}
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// reads the class's attributes
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i = readUnsignedShort(v); v += 2;
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for ( ; i > 0; --i) {
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String attrName = readUTF8(v, c);
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if (attrName.equals("SourceFile")) {
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sourceFile = readUTF8(v + 6, c);
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} else if (attrName.equals("Deprecated")) {
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access |= Constants.ACC_DEPRECATED;
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} else if (attrName.equals("InnerClasses")) {
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w = v + 6;
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} else {
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attr = readAttribute(
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attrs, attrName, v + 6, readInt(v + 2), c, -1, null);
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if (attr != null) {
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attr.next = clattrs;
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clattrs = attr;
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}
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}
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v += 6 + readInt(v + 2);
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}
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// calls the visit method
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classVisitor.visit(
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access, className, superClassName, implementedItfs, sourceFile);
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// visits the inner classes info
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if (w != 0) {
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i = readUnsignedShort(w); w += 2;
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for ( ; i > 0; --i) {
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classVisitor.visitInnerClass(
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readUnsignedShort(w) == 0 ? null : readClass(w, c),
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readUnsignedShort(w + 2) == 0 ? null : readClass(w + 2, c),
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readUnsignedShort(w + 4) == 0 ? null : readUTF8(w + 4, c),
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readUnsignedShort(w + 6));
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w += 8;
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}
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}
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// visits the fields
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i = readUnsignedShort(u); u += 2;
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for ( ; i > 0; --i) {
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access = readUnsignedShort(u);
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String fieldName = readUTF8(u + 2, c);
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String fieldDesc = readUTF8(u + 4, c);
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Attribute fattrs = null;
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// visits the field's attributes and looks for a ConstantValue attribute
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int fieldValueItem = 0;
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j = readUnsignedShort(u + 6);
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u += 8;
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for ( ; j > 0; --j) {
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String attrName = readUTF8(u, c);
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if (attrName.equals("ConstantValue")) {
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fieldValueItem = readUnsignedShort(u + 6);
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} else if (attrName.equals("Synthetic")) {
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access |= Constants.ACC_SYNTHETIC;
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} else if (attrName.equals("Deprecated")) {
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access |= Constants.ACC_DEPRECATED;
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} else {
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attr = readAttribute(
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attrs, attrName, u + 6, readInt(u + 2), c, -1, null);
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if (attr != null) {
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attr.next = fattrs;
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fattrs = attr;
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}
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}
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u += 6 + readInt(u + 2);
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}
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// reads the field's value, if any
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Object value = (fieldValueItem == 0 ? null : readConst(fieldValueItem, c));
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// visits the field
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classVisitor.visitField(access, fieldName, fieldDesc, value, fattrs);
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}
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// visits the methods
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i = readUnsignedShort(u); u += 2;
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for ( ; i > 0; --i) {
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access = readUnsignedShort(u);
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String methName = readUTF8(u + 2, c);
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String methDesc = readUTF8(u + 4, c);
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Attribute mattrs = null;
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Attribute cattrs = null;
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v = 0;
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w = 0;
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// looks for Code and Exceptions attributes
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j = readUnsignedShort(u + 6);
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u += 8;
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for ( ; j > 0; --j) {
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String attrName = readUTF8(u, c); u += 2;
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int attrSize = readInt(u); u += 4;
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if (attrName.equals("Code")) {
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v = u;
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} else if (attrName.equals("Exceptions")) {
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w = u;
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} else if (attrName.equals("Synthetic")) {
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access |= Constants.ACC_SYNTHETIC;
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} else if (attrName.equals("Deprecated")) {
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access |= Constants.ACC_DEPRECATED;
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} else {
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attr = readAttribute(attrs, attrName, u, attrSize, c, -1, null);
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if (attr != null) {
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attr.next = mattrs;
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mattrs = attr;
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}
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}
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u += attrSize;
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}
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// reads declared exceptions
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String[] exceptions;
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if (w == 0) {
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exceptions = null;
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} else {
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exceptions = new String[readUnsignedShort(w)]; w += 2;
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for (j = 0; j < exceptions.length; ++j) {
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exceptions[j] = readClass(w, c); w += 2;
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}
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}
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// visits the method's code, if any
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CodeVisitor cv;
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cv = classVisitor.visitMethod(
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access, methName, methDesc, exceptions, mattrs);
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if (cv != null && v != 0) {
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int maxStack = readUnsignedShort(v);
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int maxLocals = readUnsignedShort(v + 2);
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int codeLength = readInt(v + 4);
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v += 8;
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int codeStart = v;
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int codeEnd = v + codeLength;
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// 1st phase: finds the labels
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int label;
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Label[] labels = new Label[codeLength + 1];
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while (v < codeEnd) {
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int opcode = b[v] & 0xFF;
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switch (ClassWriter.TYPE[opcode]) {
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case ClassWriter.NOARG_INSN:
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case ClassWriter.IMPLVAR_INSN:
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v += 1;
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break;
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case ClassWriter.LABEL_INSN:
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label = v - codeStart + readShort(v + 1);
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if (labels[label] == null) {
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labels[label] = new Label();
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}
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v += 3;
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break;
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case ClassWriter.LABELW_INSN:
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label = v - codeStart + readInt(v + 1);
|
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if (labels[label] == null) {
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labels[label] = new Label();
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}
|
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v += 5;
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break;
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case ClassWriter.WIDE_INSN:
|
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opcode = b[v + 1] & 0xFF;
|
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if (opcode == Constants.IINC) {
|
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v += 6;
|
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} else {
|
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v += 4;
|
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}
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break;
|
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case ClassWriter.TABL_INSN:
|
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// skips 0 to 3 padding bytes
|
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w = v - codeStart;
|
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v = v + 4 - (w & 3);
|
|
// reads instruction
|
|
label = w + readInt(v); v += 4;
|
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if (labels[label] == null) {
|
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labels[label] = new Label();
|
|
}
|
|
j = readInt(v); v += 4;
|
|
j = readInt(v) - j + 1; v += 4;
|
|
for ( ; j > 0; --j) {
|
|
label = w + readInt(v); v += 4;
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
}
|
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break;
|
|
case ClassWriter.LOOK_INSN:
|
|
// skips 0 to 3 padding bytes
|
|
w = v - codeStart;
|
|
v = v + 4 - (w & 3);
|
|
// reads instruction
|
|
label = w + readInt(v); v += 4;
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
j = readInt(v); v += 4;
|
|
for ( ; j > 0; --j) {
|
|
v += 4; // skips key
|
|
label = w + readInt(v); v += 4;
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
}
|
|
break;
|
|
case ClassWriter.VAR_INSN:
|
|
case ClassWriter.SBYTE_INSN:
|
|
case ClassWriter.LDC_INSN:
|
|
v += 2;
|
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break;
|
|
case ClassWriter.SHORT_INSN:
|
|
case ClassWriter.LDCW_INSN:
|
|
case ClassWriter.FIELDORMETH_INSN:
|
|
case ClassWriter.TYPE_INSN:
|
|
case ClassWriter.IINC_INSN:
|
|
v += 3;
|
|
break;
|
|
case ClassWriter.ITFMETH_INSN:
|
|
v += 5;
|
|
break;
|
|
// case MANA_INSN:
|
|
default:
|
|
v += 4;
|
|
break;
|
|
}
|
|
}
|
|
// parses the try catch entries
|
|
j = readUnsignedShort(v); v += 2;
|
|
for ( ; j > 0; --j) {
|
|
label = readUnsignedShort(v);
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
label = readUnsignedShort(v + 2);
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
label = readUnsignedShort(v + 4);
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
v += 8;
|
|
}
|
|
// parses the local variable, line number tables, and code attributes
|
|
j = readUnsignedShort(v); v += 2;
|
|
for ( ; j > 0; --j) {
|
|
String attrName = readUTF8(v, c);
|
|
if (attrName.equals("LocalVariableTable")) {
|
|
if (!skipDebug) {
|
|
k = readUnsignedShort(v + 6);
|
|
w = v + 8;
|
|
for ( ; k > 0; --k) {
|
|
label = readUnsignedShort(w);
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
label += readUnsignedShort(w + 2);
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
w += 10;
|
|
}
|
|
}
|
|
} else if (attrName.equals("LineNumberTable")) {
|
|
if (!skipDebug) {
|
|
k = readUnsignedShort(v + 6);
|
|
w = v + 8;
|
|
for ( ; k > 0; --k) {
|
|
label = readUnsignedShort(w);
|
|
if (labels[label] == null) {
|
|
labels[label] = new Label();
|
|
}
|
|
w += 4;
|
|
}
|
|
}
|
|
} else {
|
|
for (k = 0; k < attrs.length; ++k) {
|
|
if (attrs[k].type.equals(attrName)) {
|
|
attr = attrs[k].read(
|
|
this, v + 6, readInt(v + 2), c, codeStart - 8, labels);
|
|
if (attr != null) {
|
|
attr.next = cattrs;
|
|
cattrs = attr;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
v += 6 + readInt(v + 2);
|
|
}
|
|
|
|
// 2nd phase: visits each instruction
|
|
v = codeStart;
|
|
Label l;
|
|
while (v < codeEnd) {
|
|
w = v - codeStart;
|
|
l = labels[w];
|
|
if (l != null) {
|
|
cv.visitLabel(l);
|
|
}
|
|
int opcode = b[v] & 0xFF;
|
|
switch (ClassWriter.TYPE[opcode]) {
|
|
case ClassWriter.NOARG_INSN:
|
|
cv.visitInsn(opcode);
|
|
v += 1;
|
|
break;
|
|
case ClassWriter.IMPLVAR_INSN:
|
|
if (opcode > Constants.ISTORE) {
|
|
opcode -= 59; //ISTORE_0
|
|
cv.visitVarInsn(Constants.ISTORE + (opcode >> 2), opcode & 0x3);
|
|
} else {
|
|
opcode -= 26; //ILOAD_0
|
|
cv.visitVarInsn(Constants.ILOAD + (opcode >> 2), opcode & 0x3);
|
|
}
|
|
v += 1;
|
|
break;
|
|
case ClassWriter.LABEL_INSN:
|
|
cv.visitJumpInsn(opcode, labels[w + readShort(v + 1)]);
|
|
v += 3;
|
|
break;
|
|
case ClassWriter.LABELW_INSN:
|
|
cv.visitJumpInsn(opcode, labels[w + readInt(v + 1)]);
|
|
v += 5;
|
|
break;
|
|
case ClassWriter.WIDE_INSN:
|
|
opcode = b[v + 1] & 0xFF;
|
|
if (opcode == Constants.IINC) {
|
|
cv.visitIincInsn(readUnsignedShort(v + 2), readShort(v + 4));
|
|
v += 6;
|
|
} else {
|
|
cv.visitVarInsn(opcode, readUnsignedShort(v + 2));
|
|
v += 4;
|
|
}
|
|
break;
|
|
case ClassWriter.TABL_INSN:
|
|
// skips 0 to 3 padding bytes
|
|
v = v + 4 - (w & 3);
|
|
// reads instruction
|
|
label = w + readInt(v); v += 4;
|
|
int min = readInt(v); v += 4;
|
|
int max = readInt(v); v += 4;
|
|
Label[] table = new Label[max - min + 1];
|
|
for (j = 0; j < table.length; ++j) {
|
|
table[j] = labels[w + readInt(v)];
|
|
v += 4;
|
|
}
|
|
cv.visitTableSwitchInsn(min, max, labels[label], table);
|
|
break;
|
|
case ClassWriter.LOOK_INSN:
|
|
// skips 0 to 3 padding bytes
|
|
v = v + 4 - (w & 3);
|
|
// reads instruction
|
|
label = w + readInt(v); v += 4;
|
|
j = readInt(v); v += 4;
|
|
int[] keys = new int[j];
|
|
Label[] values = new Label[j];
|
|
for (j = 0; j < keys.length; ++j) {
|
|
keys[j] = readInt(v); v += 4;
|
|
values[j] = labels[w + readInt(v)]; v += 4;
|
|
}
|
|
cv.visitLookupSwitchInsn(labels[label], keys, values);
|
|
break;
|
|
case ClassWriter.VAR_INSN:
|
|
cv.visitVarInsn(opcode, b[v + 1] & 0xFF);
|
|
v += 2;
|
|
break;
|
|
case ClassWriter.SBYTE_INSN:
|
|
cv.visitIntInsn(opcode, b[v + 1]);
|
|
v += 2;
|
|
break;
|
|
case ClassWriter.SHORT_INSN:
|
|
cv.visitIntInsn(opcode, readShort(v + 1));
|
|
v += 3;
|
|
break;
|
|
case ClassWriter.LDC_INSN:
|
|
cv.visitLdcInsn(readConst(b[v + 1] & 0xFF, c));
|
|
v += 2;
|
|
break;
|
|
case ClassWriter.LDCW_INSN:
|
|
cv.visitLdcInsn(readConst(readUnsignedShort(v + 1), c));
|
|
v += 3;
|
|
break;
|
|
case ClassWriter.FIELDORMETH_INSN:
|
|
case ClassWriter.ITFMETH_INSN:
|
|
int cpIndex = items[readUnsignedShort(v + 1)];
|
|
String iowner = readClass(cpIndex, c);
|
|
cpIndex = items[readUnsignedShort(cpIndex + 2)];
|
|
String iname = readUTF8(cpIndex, c);
|
|
String idesc = readUTF8(cpIndex + 2, c);
|
|
if (opcode < Constants.INVOKEVIRTUAL) {
|
|
cv.visitFieldInsn(opcode, iowner, iname, idesc);
|
|
} else {
|
|
cv.visitMethodInsn(opcode, iowner, iname, idesc);
|
|
}
|
|
if (opcode == Constants.INVOKEINTERFACE) {
|
|
v += 5;
|
|
} else {
|
|
v += 3;
|
|
}
|
|
break;
|
|
case ClassWriter.TYPE_INSN:
|
|
cv.visitTypeInsn(opcode, readClass(v + 1, c));
|
|
v += 3;
|
|
break;
|
|
case ClassWriter.IINC_INSN:
|
|
cv.visitIincInsn(b[v + 1] & 0xFF, b[v + 2]);
|
|
v += 3;
|
|
break;
|
|
// case MANA_INSN:
|
|
default:
|
|
cv.visitMultiANewArrayInsn(readClass(v + 1, c), b[v + 3] & 0xFF);
|
|
v += 4;
|
|
break;
|
|
}
|
|
}
|
|
l = labels[codeEnd - codeStart];
|
|
if (l != null) {
|
|
cv.visitLabel(l);
|
|
}
|
|
// visits the try catch entries
|
|
j = readUnsignedShort(v); v += 2;
|
|
for ( ; j > 0; --j) {
|
|
Label start = labels[readUnsignedShort(v)];
|
|
Label end = labels[readUnsignedShort(v + 2)];
|
|
Label handler = labels[readUnsignedShort(v + 4)];
|
|
int type = readUnsignedShort(v + 6);
|
|
if (type == 0) {
|
|
cv.visitTryCatchBlock(start, end, handler, null);
|
|
} else {
|
|
cv.visitTryCatchBlock(start, end, handler, readUTF8(items[type], c));
|
|
}
|
|
v += 8;
|
|
}
|
|
// visits the local variable and line number tables
|
|
j = readUnsignedShort(v); v += 2;
|
|
if (!skipDebug) {
|
|
for ( ; j > 0; --j) {
|
|
String attrName = readUTF8(v, c);
|
|
if (attrName.equals("LocalVariableTable")) {
|
|
k = readUnsignedShort(v + 6);
|
|
w = v + 8;
|
|
for ( ; k > 0; --k) {
|
|
label = readUnsignedShort(w);
|
|
Label start = labels[label];
|
|
label += readUnsignedShort(w + 2);
|
|
Label end = labels[label];
|
|
cv.visitLocalVariable(
|
|
readUTF8(w + 4, c),
|
|
readUTF8(w + 6, c),
|
|
start,
|
|
end,
|
|
readUnsignedShort(w + 8));
|
|
w += 10;
|
|
}
|
|
} else if (attrName.equals("LineNumberTable")) {
|
|
k = readUnsignedShort(v + 6);
|
|
w = v + 8;
|
|
for ( ; k > 0; --k) {
|
|
cv.visitLineNumber(
|
|
readUnsignedShort(w + 2),
|
|
labels[readUnsignedShort(w)]);
|
|
w += 4;
|
|
}
|
|
}
|
|
v += 6 + readInt(v + 2);
|
|
}
|
|
}
|
|
// visits the other attributes
|
|
while (cattrs != null) {
|
|
attr = cattrs.next;
|
|
cattrs.next = null;
|
|
cv.visitAttribute(cattrs);
|
|
cattrs = attr;
|
|
}
|
|
// visits the max stack and max locals values
|
|
cv.visitMaxs(maxStack, maxLocals);
|
|
}
|
|
}
|
|
// visits the class attributes
|
|
while (clattrs != null) {
|
|
classVisitor.visitAttribute(clattrs);
|
|
clattrs = clattrs.next;
|
|
}
|
|
// visits the end of the class
|
|
classVisitor.visitEnd();
|
|
}
|
|
|
|
// --------------------------------------------------------------------------
|
|
// Utility methods: low level parsing
|
|
// --------------------------------------------------------------------------
|
|
|
|
/**
|
|
* Reads a byte value in {@link #b b}. <i>This method is intended
|
|
* for {@link Attribute} sub classes, and is normally not needed by class
|
|
* generators or adapters.</i>
|
|
*
|
|
* @param index the start index of the value to be read in {@link #b b}.
|
|
* @return the read value.
|
|
*/
|
|
|
|
public int readByte (final int index) {
|
|
return b[index] & 0xFF;
|
|
}
|
|
|
|
/**
|
|
* Reads an unsigned short value in {@link #b b}. <i>This method is intended
|
|
* for {@link Attribute} sub classes, and is normally not needed by class
|
|
* generators or adapters.</i>
|
|
*
|
|
* @param index the start index of the value to be read in {@link #b b}.
|
|
* @return the read value.
|
|
*/
|
|
|
|
public int readUnsignedShort (final int index) {
|
|
byte[] b = this.b;
|
|
return ((b[index] & 0xFF) << 8) | (b[index + 1] & 0xFF);
|
|
}
|
|
|
|
/**
|
|
* Reads a signed short value in {@link #b b}. <i>This method is intended
|
|
* for {@link Attribute} sub classes, and is normally not needed by class
|
|
* generators or adapters.</i>
|
|
*
|
|
* @param index the start index of the value to be read in {@link #b b}.
|
|
* @return the read value.
|
|
*/
|
|
|
|
public short readShort (final int index) {
|
|
byte[] b = this.b;
|
|
return (short)(((b[index] & 0xFF) << 8) | (b[index + 1] & 0xFF));
|
|
}
|
|
|
|
/**
|
|
* Reads a signed int value in {@link #b b}. <i>This method is intended
|
|
* for {@link Attribute} sub classes, and is normally not needed by class
|
|
* generators or adapters.</i>
|
|
*
|
|
* @param index the start index of the value to be read in {@link #b b}.
|
|
* @return the read value.
|
|
*/
|
|
|
|
public int readInt (final int index) {
|
|
byte[] b = this.b;
|
|
return ((b[index] & 0xFF) << 24) |
|
|
((b[index + 1] & 0xFF) << 16) |
|
|
((b[index + 2] & 0xFF) << 8) |
|
|
(b[index + 3] & 0xFF);
|
|
}
|
|
|
|
/**
|
|
* Reads a signed long value in {@link #b b}. <i>This method is intended
|
|
* for {@link Attribute} sub classes, and is normally not needed by class
|
|
* generators or adapters.</i>
|
|
*
|
|
* @param index the start index of the value to be read in {@link #b b}.
|
|
* @return the read value.
|
|
*/
|
|
|
|
public long readLong (final int index) {
|
|
long l1 = readInt(index);
|
|
long l0 = readInt(index + 4) & 0xFFFFFFFFL;
|
|
return (l1 << 32) | l0;
|
|
}
|
|
|
|
/**
|
|
* Reads an UTF8 string constant pool item in {@link #b b}. <i>This method is
|
|
* intended for {@link Attribute} sub classes, and is normally not needed by
|
|
* class generators or adapters.</i>
|
|
*
|
|
* @param index the start index of an unsigned short value in {@link #b b},
|
|
* whose value is the index of an UTF8 constant pool item.
|
|
* @param buf buffer to be used to read the item. This buffer must be
|
|
* sufficiently large. It is not automatically resized.
|
|
* @return the String corresponding to the specified UTF8 item.
|
|
*/
|
|
|
|
public String readUTF8 (int index, final char[] buf) {
|
|
// consults cache
|
|
int item = readUnsignedShort(index);
|
|
String s = strings[item];
|
|
if (s != null) {
|
|
return s;
|
|
}
|
|
// computes the start index of the CONSTANT_Utf8 item in b
|
|
index = items[item];
|
|
// reads the length of the string (in bytes, not characters)
|
|
int utfLen = readUnsignedShort(index);
|
|
index += 2;
|
|
// parses the string bytes
|
|
int endIndex = index + utfLen;
|
|
byte[] b = this.b;
|
|
int strLen = 0;
|
|
int c, d, e;
|
|
while (index < endIndex) {
|
|
c = b[index++] & 0xFF;
|
|
switch (c >> 4) {
|
|
case 0:
|
|
case 1:
|
|
case 2:
|
|
case 3:
|
|
case 4:
|
|
case 5:
|
|
case 6:
|
|
case 7:
|
|
// 0xxxxxxx
|
|
buf[strLen++] = (char)c;
|
|
break;
|
|
case 12:
|
|
case 13:
|
|
// 110x xxxx 10xx xxxx
|
|
d = b[index++];
|
|
buf[strLen++] = (char)(((c & 0x1F) << 6) | (d & 0x3F));
|
|
break;
|
|
default:
|
|
// 1110 xxxx 10xx xxxx 10xx xxxx
|
|
d = b[index++];
|
|
e = b[index++];
|
|
buf[strLen++] =
|
|
(char)(((c & 0x0F) << 12) | ((d & 0x3F) << 6) | (e & 0x3F));
|
|
break;
|
|
}
|
|
}
|
|
s = new String(buf, 0, strLen);
|
|
strings[item] = s;
|
|
return s;
|
|
}
|
|
|
|
/**
|
|
* Reads a class constant pool item in {@link #b b}. <i>This method is
|
|
* intended for {@link Attribute} sub classes, and is normally not needed by
|
|
* class generators or adapters.</i>
|
|
*
|
|
* @param index the start index of an unsigned short value in {@link #b b},
|
|
* whose value is the index of a class constant pool item.
|
|
* @param buf buffer to be used to read the item. This buffer must be
|
|
* sufficiently large. It is not automatically resized.
|
|
* @return the String corresponding to the specified class item.
|
|
*/
|
|
|
|
public String readClass (final int index, final char[] buf) {
|
|
// computes the start index of the CONSTANT_Class item in b
|
|
// and reads the CONSTANT_Utf8 item designated by
|
|
// the first two bytes of this CONSTANT_Class item
|
|
return readUTF8(items[readUnsignedShort(index)], buf);
|
|
}
|
|
|
|
/**
|
|
* Reads a numeric or string constant pool item in {@link #b b}. <i>This
|
|
* method is intended for {@link Attribute} sub classes, and is normally not
|
|
* needed by class generators or adapters.</i>
|
|
*
|
|
* @param item the index of a constant pool item.
|
|
* @param buf buffer to be used to read the item. This buffer must be
|
|
* sufficiently large. It is not automatically resized.
|
|
* @return the {@link java.lang.Integer Integer}, {@link java.lang.Float
|
|
* Float}, {@link java.lang.Long Long}, {@link java.lang.Double Double}
|
|
* or {@link String String} corresponding to the given constant pool
|
|
* item.
|
|
*/
|
|
|
|
public Object readConst (final int item, final char[] buf) {
|
|
int index = items[item];
|
|
switch (b[index - 1]) {
|
|
case ClassWriter.INT:
|
|
return new Integer(readInt(index));
|
|
case ClassWriter.FLOAT:
|
|
return new Float(Float.intBitsToFloat(readInt(index)));
|
|
case ClassWriter.LONG:
|
|
return new Long(readLong(index));
|
|
case ClassWriter.DOUBLE:
|
|
return new Double(Double.longBitsToDouble(readLong(index)));
|
|
//case ClassWriter.STR:
|
|
default:
|
|
return readUTF8(index, buf);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Reads an attribute in {@link #b b}. The default implementation of this
|
|
* method returns <tt>null</tt> for all attributes.
|
|
*
|
|
* @param attrs prototypes of the attributes that must be parsed during the
|
|
* visit of the class. Any attribute whose type is not equal to the type
|
|
* of one the prototypes will be ignored.
|
|
* @param type the type of the attribute.
|
|
* @param off index of the first byte of the attribute's content in {@link #b
|
|
* b}. The 6 attribute header bytes, containing the type and the length
|
|
* of the attribute, are not taken into account here (they have already
|
|
* been read).
|
|
* @param len the length of the attribute's content.
|
|
* @param buf buffer to be used to call {@link #readUTF8 readUTF8}, {@link
|
|
* #readClass readClass} or {@link #readConst readConst}.
|
|
* @param codeOff index of the first byte of code's attribute content in
|
|
* {@link #b 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 the attribute that has been read, or <tt>null</tt> to skip this
|
|
* attribute.
|
|
*/
|
|
|
|
protected Attribute readAttribute (
|
|
final Attribute[] attrs,
|
|
final String type,
|
|
final int off,
|
|
final int len,
|
|
final char[] buf,
|
|
final int codeOff,
|
|
final Label[] labels)
|
|
{
|
|
for (int i = 0; i < attrs.length; ++i) {
|
|
if (attrs[i].type.equals(type)) {
|
|
return attrs[i].read(this, off, len, buf, codeOff, labels);
|
|
}
|
|
}
|
|
return null;
|
|
}
|
|
}
|