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/* * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.invoke.anon; import java.io.IOException;import java.io.OutputStream;import java.nio.BufferUnderflowException;import java.nio.ByteBuffer; import static sun.invoke.anon.ConstantPoolVisitor.*; /** A constant pool parser. */public class ConstantPoolParser {    final byte[] classFile;    final byte[] tags;    final char[] firstHeader;  // maghi, maglo, minor, major, cplen     // these are filled in on first parse:    int endOffset;    char[] secondHeader;       // flags, this_class, super_class, intlen     // used to decode UTF8 array    private char[] charArray = new char[80];     /** Creates a constant pool parser.     * @param classFile an array of bytes containing a class.     * @throws InvalidConstantPoolFormatException if the header of the class has errors.     */    public ConstantPoolParser(byte[] classFile) throws InvalidConstantPoolFormatException {        this.classFile = classFile;        this.firstHeader = parseHeader(classFile);        this.tags = new byte[firstHeader[4]];    }     /** Create a constant pool parser by loading the bytecodes of the     *  class taken as argument.     *     * @param templateClass the class to parse.     *     * @throws IOException raised if an I/O occurs when loading     *  the bytecode of the template class.     * @throws InvalidConstantPoolFormatException if the header of the class has errors.     *     * @see #ConstantPoolParser(byte[])     * @see AnonymousClassLoader#readClassFile(Class)     */    public ConstantPoolParser(Class<?> templateClass) throws IOException, InvalidConstantPoolFormatException {        this(AnonymousClassLoader.readClassFile(templateClass));    }     /** Creates an empty patch to patch the class file     *  used by the current parser.     * @return a new class patch.     */    public ConstantPoolPatch createPatch() {        return new ConstantPoolPatch(this);    }     /** Report the tag of the indicated CP entry.     * @param index     * @return one of {@link ConstantPoolVisitor#CONSTANT_Utf8}, etc.     */    public byte getTag(int index) {        getEndOffset();  // trigger an exception if we haven't parsed yet        return tags[index];    }     /** Report the length of the constant pool. */    public int getLength() {        return firstHeader[4];    }     /** Report the offset, within the class file, of the start of the constant pool. */    public int getStartOffset() {        return firstHeader.length * 2;    }     /** Report the offset, within the class file, of the end of the constant pool. */    public int getEndOffset() {        if (endOffset == 0)            throw new IllegalStateException("class file has not yet been parsed");        return endOffset;    }     /** Report the CP index of this class's own name. */    public int getThisClassIndex() {        getEndOffset();   // provoke exception if not yet parsed        return secondHeader[1];    }     /** Report the total size of the class file. */    public int getTailLength() {        return classFile.length - getEndOffset();    }     /** Write the head (header plus constant pool)     *  of the class file to the indicated stream.     */    public void writeHead(OutputStream out) throws IOException {        out.write(classFile, 0, getEndOffset());    }     /** Write the head (header plus constant pool)     *  of the class file to the indicated stream,     *  incorporating the non-null entries of the given array     *  as patches.     */    void writePatchedHead(OutputStream out, Object[] patchArray) {        // this will be useful to partially emulate the class loader on old JVMs        throw new UnsupportedOperationException("Not yet implemented");    }     /** Write the tail (everything after the constant pool)     *  of the class file to the indicated stream.     */    public void writeTail(OutputStream out) throws IOException {        out.write(classFile, getEndOffset(), getTailLength());    }     private static char[] parseHeader(byte[] classFile) throws InvalidConstantPoolFormatException {        char[] result = new char[5];        ByteBuffer buffer = ByteBuffer.wrap(classFile);        for (int i = 0; i < result.length; i++)            result[i] = (char) getUnsignedShort(buffer);        int magic = result[0] << 16 | result[1] << 0;        if (magic != 0xCAFEBABE)            throw new InvalidConstantPoolFormatException("invalid magic number "+magic);        // skip major, minor version        int len = result[4];        if (len < 1)            throw new InvalidConstantPoolFormatException("constant pool length < 1");        return result;    }     /** Parse the constant pool of the class     *  calling a method visit* each time a constant pool entry is parsed.     *     *  The order of the calls to visit* is not guaranteed to be the same     *  than the order of the constant pool entry in the bytecode array.     *     * @param visitor     * @throws InvalidConstantPoolFormatException     */    public void parse(ConstantPoolVisitor visitor) throws InvalidConstantPoolFormatException {        ByteBuffer buffer = ByteBuffer.wrap(classFile);        buffer.position(getStartOffset()); //skip header         Object[] values = new Object[getLength()];        try {            parseConstantPool(buffer, values, visitor);        } catch(BufferUnderflowException e) {            throw new InvalidConstantPoolFormatException(e);        }        if (endOffset == 0) {            endOffset = buffer.position();            secondHeader = new char[4];            for (int i = 0; i < secondHeader.length; i++) {                secondHeader[i] = (char) getUnsignedShort(buffer);            }        }        resolveConstantPool(values, visitor);    }     private char[] getCharArray(int utfLength) {        if (utfLength <= charArray.length)            return charArray;        return charArray = new char[utfLength];    }     private void parseConstantPool(ByteBuffer buffer, Object[] values, ConstantPoolVisitor visitor) throws InvalidConstantPoolFormatException {        for (int i = 1; i < tags.length; ) {            byte tag = (byte) getUnsignedByte(buffer);            assert(tags[i] == 0 || tags[i] == tag);            tags[i] = tag;            switch (tag) {                case CONSTANT_Utf8:                    int utfLen = getUnsignedShort(buffer);                    String value = getUTF8(buffer, utfLen, getCharArray(utfLen));                    visitor.visitUTF8(i, CONSTANT_Utf8, value);                    tags[i] = tag;                    values[i++] = value;                    break;                case CONSTANT_Integer:                    visitor.visitConstantValue(i, tag, buffer.getInt());                    i++;                    break;                case CONSTANT_Float:                    visitor.visitConstantValue(i, tag, buffer.getFloat());                    i++;                    break;                case CONSTANT_Long:                    visitor.visitConstantValue(i, tag, buffer.getLong());                    i+=2;                    break;                case CONSTANT_Double:                    visitor.visitConstantValue(i, tag, buffer.getDouble());                    i+=2;                    break;                 case CONSTANT_Class:    // fall through:                case CONSTANT_String:                    tags[i] = tag;                    values[i++] = new int[] { getUnsignedShort(buffer) };                    break;                 case CONSTANT_Fieldref:           // fall through:                case CONSTANT_Methodref:          // fall through:                case CONSTANT_InterfaceMethodref: // fall through:                case CONSTANT_NameAndType:                    tags[i] = tag;                    values[i++] = new int[] { getUnsignedShort(buffer), getUnsignedShort(buffer) };                    break;                default:                    throw new AssertionError("invalid constant "+tag);            }        }    }     private void resolveConstantPool(Object[] values, ConstantPoolVisitor visitor) {        // clean out the int[] values, which are temporary        for (int beg = 1, end = values.length-1, beg2, end2;             beg <= end;             beg = beg2, end = end2) {             beg2 = end; end2 = beg-1;             //System.out.println("CP resolve pass: "+beg+".."+end);             for (int i = beg; i <= end; i++) {                  Object value = values[i];                  if (!(value instanceof int[]))                      continue;                  int[] array = (int[]) value;                  byte tag = tags[i];                  switch (tag) {                      case CONSTANT_String:                          String stringBody = (String) values[array[0]];                          visitor.visitConstantString(i, tag, stringBody, array[0]);                          values[i] = null;                          break;                      case CONSTANT_Class: {                          String className = (String) values[array[0]];                          // use the external form favored by Class.forName:                          className = className.replace('/', '.');                          visitor.visitConstantString(i, tag, className, array[0]);                          values[i] = className;                          break;                      }                      case CONSTANT_NameAndType: {                          String memberName = (String) values[array[0]];                          String signature  = (String) values[array[1]];                          visitor.visitDescriptor(i, tag, memberName, signature,                                                  array[0], array[1]);                          values[i] = new String[] {memberName, signature};                          break;                      }                      case CONSTANT_Fieldref:           // fall through:                      case CONSTANT_Methodref:          // fall through:                      case CONSTANT_InterfaceMethodref: {                              Object className   = values[array[0]];                              Object nameAndType = values[array[1]];                              if (!(className instanceof String) ||                                  !(nameAndType instanceof String[])) {                                   // one more pass is needed                                   if (beg2 > i)  beg2 = i;                                   if (end2 < i)  end2 = i;                                   continue;                              }                              String[] nameAndTypeArray = (String[]) nameAndType;                              visitor.visitMemberRef(i, tag,                                  (String)className,                                  nameAndTypeArray[0],                                  nameAndTypeArray[1],                                  array[0], array[1]);                              values[i] = null;                          }                          break;                      default:                          continue;                }            }        }    }     private static int getUnsignedByte(ByteBuffer buffer) {        return buffer.get() & 0xFF;    }     private static int getUnsignedShort(ByteBuffer buffer) {        int b1 = getUnsignedByte(buffer);        int b2 = getUnsignedByte(buffer);        return (b1 << 8) + (b2 << 0);    }     private static String getUTF8(ByteBuffer buffer, int utfLen, char[] charArray) throws InvalidConstantPoolFormatException {      int utfLimit = buffer.position() + utfLen;      int index = 0;      while (buffer.position() < utfLimit) {          int c = buffer.get() & 0xff;          if (c > 127) {              buffer.position(buffer.position() - 1);              return getUTF8Extended(buffer, utfLimit, charArray, index);          }          charArray[index++] = (char)c;      }      return new String(charArray, 0, index);    }     private static String getUTF8Extended(ByteBuffer buffer, int utfLimit, char[] charArray, int index) throws InvalidConstantPoolFormatException {        int c, c2, c3;        while (buffer.position() < utfLimit) {            c = buffer.get() & 0xff;            switch (c >> 4) {                case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:                    /* 0xxxxxxx*/                    charArray[index++] = (char)c;                    break;                case 12: case 13:                    /* 110x xxxx   10xx xxxx*/                    c2 = buffer.get();                    if ((c2 & 0xC0) != 0x80)                        throw new InvalidConstantPoolFormatException(                            "malformed input around byte " + buffer.position());                     charArray[index++] = (char)(((c  & 0x1F) << 6) |                                                  (c2 & 0x3F));                    break;                case 14:                    /* 1110 xxxx  10xx xxxx  10xx xxxx */                    c2 = buffer.get();                    c3 = buffer.get();                    if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80))                       throw new InvalidConstantPoolFormatException(                          "malformed input around byte " + (buffer.position()));                    charArray[index++] = (char)(((c  & 0x0F) << 12) |                                                ((c2 & 0x3F) << 6)  |                                                ((c3 & 0x3F) << 0));                    break;                default:                    /* 10xx xxxx,  1111 xxxx */                    throw new InvalidConstantPoolFormatException(                        "malformed input around byte " + buffer.position());            }        }        // The number of chars produced may be less than utflen        return new String(charArray, 0, index);    }}