rt/emul/compact/src/main/java/sun/invoke/anon/ConstantPoolParser.java
branchjdk8-b132
changeset 1646 c880a8a8803b
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/rt/emul/compact/src/main/java/sun/invoke/anon/ConstantPoolParser.java	Sat Aug 09 11:11:13 2014 +0200
     1.3 @@ -0,0 +1,368 @@
     1.4 +/*
     1.5 + * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
     1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     1.7 + *
     1.8 + * This code is free software; you can redistribute it and/or modify it
     1.9 + * under the terms of the GNU General Public License version 2 only, as
    1.10 + * published by the Free Software Foundation.  Oracle designates this
    1.11 + * particular file as subject to the "Classpath" exception as provided
    1.12 + * by Oracle in the LICENSE file that accompanied this code.
    1.13 + *
    1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
    1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    1.16 + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    1.17 + * version 2 for more details (a copy is included in the LICENSE file that
    1.18 + * accompanied this code).
    1.19 + *
    1.20 + * You should have received a copy of the GNU General Public License version
    1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
    1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    1.23 + *
    1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    1.25 + * or visit www.oracle.com if you need additional information or have any
    1.26 + * questions.
    1.27 + */
    1.28 +
    1.29 +package sun.invoke.anon;
    1.30 +
    1.31 +import java.io.IOException;
    1.32 +import java.io.OutputStream;
    1.33 +import java.nio.BufferUnderflowException;
    1.34 +import java.nio.ByteBuffer;
    1.35 +
    1.36 +import static sun.invoke.anon.ConstantPoolVisitor.*;
    1.37 +
    1.38 +/** A constant pool parser.
    1.39 + */
    1.40 +public class ConstantPoolParser {
    1.41 +    final byte[] classFile;
    1.42 +    final byte[] tags;
    1.43 +    final char[] firstHeader;  // maghi, maglo, minor, major, cplen
    1.44 +
    1.45 +    // these are filled in on first parse:
    1.46 +    int endOffset;
    1.47 +    char[] secondHeader;       // flags, this_class, super_class, intlen
    1.48 +
    1.49 +    // used to decode UTF8 array
    1.50 +    private char[] charArray = new char[80];
    1.51 +
    1.52 +    /** Creates a constant pool parser.
    1.53 +     * @param classFile an array of bytes containing a class.
    1.54 +     * @throws InvalidConstantPoolFormatException if the header of the class has errors.
    1.55 +     */
    1.56 +    public ConstantPoolParser(byte[] classFile) throws InvalidConstantPoolFormatException {
    1.57 +        this.classFile = classFile;
    1.58 +        this.firstHeader = parseHeader(classFile);
    1.59 +        this.tags = new byte[firstHeader[4]];
    1.60 +    }
    1.61 +
    1.62 +    /** Create a constant pool parser by loading the bytecodes of the
    1.63 +     *  class taken as argument.
    1.64 +     *
    1.65 +     * @param templateClass the class to parse.
    1.66 +     *
    1.67 +     * @throws IOException raised if an I/O occurs when loading
    1.68 +     *  the bytecode of the template class.
    1.69 +     * @throws InvalidConstantPoolFormatException if the header of the class has errors.
    1.70 +     *
    1.71 +     * @see #ConstantPoolParser(byte[])
    1.72 +     * @see AnonymousClassLoader#readClassFile(Class)
    1.73 +     */
    1.74 +    public ConstantPoolParser(Class<?> templateClass) throws IOException, InvalidConstantPoolFormatException {
    1.75 +        this(AnonymousClassLoader.readClassFile(templateClass));
    1.76 +    }
    1.77 +
    1.78 +    /** Creates an empty patch to patch the class file
    1.79 +     *  used by the current parser.
    1.80 +     * @return a new class patch.
    1.81 +     */
    1.82 +    public ConstantPoolPatch createPatch() {
    1.83 +        return new ConstantPoolPatch(this);
    1.84 +    }
    1.85 +
    1.86 +    /** Report the tag of the indicated CP entry.
    1.87 +     * @param index
    1.88 +     * @return one of {@link ConstantPoolVisitor#CONSTANT_Utf8}, etc.
    1.89 +     */
    1.90 +    public byte getTag(int index) {
    1.91 +        getEndOffset();  // trigger an exception if we haven't parsed yet
    1.92 +        return tags[index];
    1.93 +    }
    1.94 +
    1.95 +    /** Report the length of the constant pool. */
    1.96 +    public int getLength() {
    1.97 +        return firstHeader[4];
    1.98 +    }
    1.99 +
   1.100 +    /** Report the offset, within the class file, of the start of the constant pool. */
   1.101 +    public int getStartOffset() {
   1.102 +        return firstHeader.length * 2;
   1.103 +    }
   1.104 +
   1.105 +    /** Report the offset, within the class file, of the end of the constant pool. */
   1.106 +    public int getEndOffset() {
   1.107 +        if (endOffset == 0)
   1.108 +            throw new IllegalStateException("class file has not yet been parsed");
   1.109 +        return endOffset;
   1.110 +    }
   1.111 +
   1.112 +    /** Report the CP index of this class's own name. */
   1.113 +    public int getThisClassIndex() {
   1.114 +        getEndOffset();   // provoke exception if not yet parsed
   1.115 +        return secondHeader[1];
   1.116 +    }
   1.117 +
   1.118 +    /** Report the total size of the class file. */
   1.119 +    public int getTailLength() {
   1.120 +        return classFile.length - getEndOffset();
   1.121 +    }
   1.122 +
   1.123 +    /** Write the head (header plus constant pool)
   1.124 +     *  of the class file to the indicated stream.
   1.125 +     */
   1.126 +    public void writeHead(OutputStream out) throws IOException {
   1.127 +        out.write(classFile, 0, getEndOffset());
   1.128 +    }
   1.129 +
   1.130 +    /** Write the head (header plus constant pool)
   1.131 +     *  of the class file to the indicated stream,
   1.132 +     *  incorporating the non-null entries of the given array
   1.133 +     *  as patches.
   1.134 +     */
   1.135 +    void writePatchedHead(OutputStream out, Object[] patchArray) {
   1.136 +        // this will be useful to partially emulate the class loader on old JVMs
   1.137 +        throw new UnsupportedOperationException("Not yet implemented");
   1.138 +    }
   1.139 +
   1.140 +    /** Write the tail (everything after the constant pool)
   1.141 +     *  of the class file to the indicated stream.
   1.142 +     */
   1.143 +    public void writeTail(OutputStream out) throws IOException {
   1.144 +        out.write(classFile, getEndOffset(), getTailLength());
   1.145 +    }
   1.146 +
   1.147 +    private static char[] parseHeader(byte[] classFile) throws InvalidConstantPoolFormatException {
   1.148 +        char[] result = new char[5];
   1.149 +        ByteBuffer buffer = ByteBuffer.wrap(classFile);
   1.150 +        for (int i = 0; i < result.length; i++)
   1.151 +            result[i] = (char) getUnsignedShort(buffer);
   1.152 +        int magic = result[0] << 16 | result[1] << 0;
   1.153 +        if (magic != 0xCAFEBABE)
   1.154 +            throw new InvalidConstantPoolFormatException("invalid magic number "+magic);
   1.155 +        // skip major, minor version
   1.156 +        int len = result[4];
   1.157 +        if (len < 1)
   1.158 +            throw new InvalidConstantPoolFormatException("constant pool length < 1");
   1.159 +        return result;
   1.160 +    }
   1.161 +
   1.162 +    /** Parse the constant pool of the class
   1.163 +     *  calling a method visit* each time a constant pool entry is parsed.
   1.164 +     *
   1.165 +     *  The order of the calls to visit* is not guaranteed to be the same
   1.166 +     *  than the order of the constant pool entry in the bytecode array.
   1.167 +     *
   1.168 +     * @param visitor
   1.169 +     * @throws InvalidConstantPoolFormatException
   1.170 +     */
   1.171 +    public void parse(ConstantPoolVisitor visitor) throws InvalidConstantPoolFormatException {
   1.172 +        ByteBuffer buffer = ByteBuffer.wrap(classFile);
   1.173 +        buffer.position(getStartOffset()); //skip header
   1.174 +
   1.175 +        Object[] values = new Object[getLength()];
   1.176 +        try {
   1.177 +            parseConstantPool(buffer, values, visitor);
   1.178 +        } catch(BufferUnderflowException e) {
   1.179 +            throw new InvalidConstantPoolFormatException(e);
   1.180 +        }
   1.181 +        if (endOffset == 0) {
   1.182 +            endOffset = buffer.position();
   1.183 +            secondHeader = new char[4];
   1.184 +            for (int i = 0; i < secondHeader.length; i++) {
   1.185 +                secondHeader[i] = (char) getUnsignedShort(buffer);
   1.186 +            }
   1.187 +        }
   1.188 +        resolveConstantPool(values, visitor);
   1.189 +    }
   1.190 +
   1.191 +    private char[] getCharArray(int utfLength) {
   1.192 +        if (utfLength <= charArray.length)
   1.193 +            return charArray;
   1.194 +        return charArray = new char[utfLength];
   1.195 +    }
   1.196 +
   1.197 +    private void parseConstantPool(ByteBuffer buffer, Object[] values, ConstantPoolVisitor visitor) throws InvalidConstantPoolFormatException {
   1.198 +        for (int i = 1; i < tags.length; ) {
   1.199 +            byte tag = (byte) getUnsignedByte(buffer);
   1.200 +            assert(tags[i] == 0 || tags[i] == tag);
   1.201 +            tags[i] = tag;
   1.202 +            switch (tag) {
   1.203 +                case CONSTANT_Utf8:
   1.204 +                    int utfLen = getUnsignedShort(buffer);
   1.205 +                    String value = getUTF8(buffer, utfLen, getCharArray(utfLen));
   1.206 +                    visitor.visitUTF8(i, CONSTANT_Utf8, value);
   1.207 +                    tags[i] = tag;
   1.208 +                    values[i++] = value;
   1.209 +                    break;
   1.210 +                case CONSTANT_Integer:
   1.211 +                    visitor.visitConstantValue(i, tag, buffer.getInt());
   1.212 +                    i++;
   1.213 +                    break;
   1.214 +                case CONSTANT_Float:
   1.215 +                    visitor.visitConstantValue(i, tag, buffer.getFloat());
   1.216 +                    i++;
   1.217 +                    break;
   1.218 +                case CONSTANT_Long:
   1.219 +                    visitor.visitConstantValue(i, tag, buffer.getLong());
   1.220 +                    i+=2;
   1.221 +                    break;
   1.222 +                case CONSTANT_Double:
   1.223 +                    visitor.visitConstantValue(i, tag, buffer.getDouble());
   1.224 +                    i+=2;
   1.225 +                    break;
   1.226 +
   1.227 +                case CONSTANT_Class:    // fall through:
   1.228 +                case CONSTANT_String:
   1.229 +                    tags[i] = tag;
   1.230 +                    values[i++] = new int[] { getUnsignedShort(buffer) };
   1.231 +                    break;
   1.232 +
   1.233 +                case CONSTANT_Fieldref:           // fall through:
   1.234 +                case CONSTANT_Methodref:          // fall through:
   1.235 +                case CONSTANT_InterfaceMethodref: // fall through:
   1.236 +                case CONSTANT_NameAndType:
   1.237 +                    tags[i] = tag;
   1.238 +                    values[i++] = new int[] { getUnsignedShort(buffer), getUnsignedShort(buffer) };
   1.239 +                    break;
   1.240 +                default:
   1.241 +                    throw new AssertionError("invalid constant "+tag);
   1.242 +            }
   1.243 +        }
   1.244 +    }
   1.245 +
   1.246 +    private void resolveConstantPool(Object[] values, ConstantPoolVisitor visitor) {
   1.247 +        // clean out the int[] values, which are temporary
   1.248 +        for (int beg = 1, end = values.length-1, beg2, end2;
   1.249 +             beg <= end;
   1.250 +             beg = beg2, end = end2) {
   1.251 +             beg2 = end; end2 = beg-1;
   1.252 +             //System.out.println("CP resolve pass: "+beg+".."+end);
   1.253 +             for (int i = beg; i <= end; i++) {
   1.254 +                  Object value = values[i];
   1.255 +                  if (!(value instanceof int[]))
   1.256 +                      continue;
   1.257 +                  int[] array = (int[]) value;
   1.258 +                  byte tag = tags[i];
   1.259 +                  switch (tag) {
   1.260 +                      case CONSTANT_String:
   1.261 +                          String stringBody = (String) values[array[0]];
   1.262 +                          visitor.visitConstantString(i, tag, stringBody, array[0]);
   1.263 +                          values[i] = null;
   1.264 +                          break;
   1.265 +                      case CONSTANT_Class: {
   1.266 +                          String className = (String) values[array[0]];
   1.267 +                          // use the external form favored by Class.forName:
   1.268 +                          className = className.replace('/', '.');
   1.269 +                          visitor.visitConstantString(i, tag, className, array[0]);
   1.270 +                          values[i] = className;
   1.271 +                          break;
   1.272 +                      }
   1.273 +                      case CONSTANT_NameAndType: {
   1.274 +                          String memberName = (String) values[array[0]];
   1.275 +                          String signature  = (String) values[array[1]];
   1.276 +                          visitor.visitDescriptor(i, tag, memberName, signature,
   1.277 +                                                  array[0], array[1]);
   1.278 +                          values[i] = new String[] {memberName, signature};
   1.279 +                          break;
   1.280 +                      }
   1.281 +                      case CONSTANT_Fieldref:           // fall through:
   1.282 +                      case CONSTANT_Methodref:          // fall through:
   1.283 +                      case CONSTANT_InterfaceMethodref: {
   1.284 +                              Object className   = values[array[0]];
   1.285 +                              Object nameAndType = values[array[1]];
   1.286 +                              if (!(className instanceof String) ||
   1.287 +                                  !(nameAndType instanceof String[])) {
   1.288 +                                   // one more pass is needed
   1.289 +                                   if (beg2 > i)  beg2 = i;
   1.290 +                                   if (end2 < i)  end2 = i;
   1.291 +                                   continue;
   1.292 +                              }
   1.293 +                              String[] nameAndTypeArray = (String[]) nameAndType;
   1.294 +                              visitor.visitMemberRef(i, tag,
   1.295 +                                  (String)className,
   1.296 +                                  nameAndTypeArray[0],
   1.297 +                                  nameAndTypeArray[1],
   1.298 +                                  array[0], array[1]);
   1.299 +                              values[i] = null;
   1.300 +                          }
   1.301 +                          break;
   1.302 +                      default:
   1.303 +                          continue;
   1.304 +                }
   1.305 +            }
   1.306 +        }
   1.307 +    }
   1.308 +
   1.309 +    private static int getUnsignedByte(ByteBuffer buffer) {
   1.310 +        return buffer.get() & 0xFF;
   1.311 +    }
   1.312 +
   1.313 +    private static int getUnsignedShort(ByteBuffer buffer) {
   1.314 +        int b1 = getUnsignedByte(buffer);
   1.315 +        int b2 = getUnsignedByte(buffer);
   1.316 +        return (b1 << 8) + (b2 << 0);
   1.317 +    }
   1.318 +
   1.319 +    private static String getUTF8(ByteBuffer buffer, int utfLen, char[] charArray) throws InvalidConstantPoolFormatException {
   1.320 +      int utfLimit = buffer.position() + utfLen;
   1.321 +      int index = 0;
   1.322 +      while (buffer.position() < utfLimit) {
   1.323 +          int c = buffer.get() & 0xff;
   1.324 +          if (c > 127) {
   1.325 +              buffer.position(buffer.position() - 1);
   1.326 +              return getUTF8Extended(buffer, utfLimit, charArray, index);
   1.327 +          }
   1.328 +          charArray[index++] = (char)c;
   1.329 +      }
   1.330 +      return new String(charArray, 0, index);
   1.331 +    }
   1.332 +
   1.333 +    private static String getUTF8Extended(ByteBuffer buffer, int utfLimit, char[] charArray, int index) throws InvalidConstantPoolFormatException {
   1.334 +        int c, c2, c3;
   1.335 +        while (buffer.position() < utfLimit) {
   1.336 +            c = buffer.get() & 0xff;
   1.337 +            switch (c >> 4) {
   1.338 +                case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
   1.339 +                    /* 0xxxxxxx*/
   1.340 +                    charArray[index++] = (char)c;
   1.341 +                    break;
   1.342 +                case 12: case 13:
   1.343 +                    /* 110x xxxx   10xx xxxx*/
   1.344 +                    c2 = buffer.get();
   1.345 +                    if ((c2 & 0xC0) != 0x80)
   1.346 +                        throw new InvalidConstantPoolFormatException(
   1.347 +                            "malformed input around byte " + buffer.position());
   1.348 +                     charArray[index++] = (char)(((c  & 0x1F) << 6) |
   1.349 +                                                  (c2 & 0x3F));
   1.350 +                    break;
   1.351 +                case 14:
   1.352 +                    /* 1110 xxxx  10xx xxxx  10xx xxxx */
   1.353 +                    c2 = buffer.get();
   1.354 +                    c3 = buffer.get();
   1.355 +                    if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80))
   1.356 +                       throw new InvalidConstantPoolFormatException(
   1.357 +                          "malformed input around byte " + (buffer.position()));
   1.358 +                    charArray[index++] = (char)(((c  & 0x0F) << 12) |
   1.359 +                                                ((c2 & 0x3F) << 6)  |
   1.360 +                                                ((c3 & 0x3F) << 0));
   1.361 +                    break;
   1.362 +                default:
   1.363 +                    /* 10xx xxxx,  1111 xxxx */
   1.364 +                    throw new InvalidConstantPoolFormatException(
   1.365 +                        "malformed input around byte " + buffer.position());
   1.366 +            }
   1.367 +        }
   1.368 +        // The number of chars produced may be less than utflen
   1.369 +        return new String(charArray, 0, index);
   1.370 +    }
   1.371 +}