001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 */
017
018package org.apache.bcel.classfile;
019
020import java.io.ByteArrayInputStream;
021import java.io.ByteArrayOutputStream;
022import java.io.CharArrayReader;
023import java.io.CharArrayWriter;
024import java.io.FilterReader;
025import java.io.FilterWriter;
026import java.io.IOException;
027import java.io.PrintStream;
028import java.io.PrintWriter;
029import java.io.Reader;
030import java.io.Writer;
031import java.util.ArrayList;
032import java.util.Arrays;
033import java.util.List;
034import java.util.Locale;
035import java.util.zip.GZIPInputStream;
036import java.util.zip.GZIPOutputStream;
037
038import org.apache.bcel.Const;
039import org.apache.bcel.util.ByteSequence;
040import org.apache.commons.lang3.ArrayUtils;
041
042/**
043 * Utility functions that do not really belong to any class in particular.
044 */
045// @since 6.0 methods are no longer final
046public abstract class Utility {
047
048    /**
049     * Decode characters into bytes. Used by <a href="Utility.html#decode(java.lang.String, boolean)">decode()</a>
050     */
051    private static class JavaReader extends FilterReader {
052
053        public JavaReader(final Reader in) {
054            super(in);
055        }
056
057        @Override
058        public int read() throws IOException {
059            final int b = in.read();
060            if (b != ESCAPE_CHAR) {
061                return b;
062            }
063            final int i = in.read();
064            if (i < 0) {
065                return -1;
066            }
067            if (i >= '0' && i <= '9' || i >= 'a' && i <= 'f') { // Normal escape
068                final int j = in.read();
069                if (j < 0) {
070                    return -1;
071                }
072                final char[] tmp = {(char) i, (char) j};
073                return Integer.parseInt(new String(tmp), 16);
074            }
075            return MAP_CHAR[i];
076        }
077
078        @Override
079        public int read(final char[] cbuf, final int off, final int len) throws IOException {
080            for (int i = 0; i < len; i++) {
081                cbuf[off + i] = (char) read();
082            }
083            return len;
084        }
085    }
086
087    /**
088     * Encode bytes into valid java identifier characters. Used by
089     * <a href="Utility.html#encode(byte[], boolean)">encode()</a>
090     */
091    private static class JavaWriter extends FilterWriter {
092
093        public JavaWriter(final Writer out) {
094            super(out);
095        }
096
097        @Override
098        public void write(final char[] cbuf, final int off, final int len) throws IOException {
099            for (int i = 0; i < len; i++) {
100                write(cbuf[off + i]);
101            }
102        }
103
104        @Override
105        public void write(final int b) throws IOException {
106            if (isJavaIdentifierPart((char) b) && b != ESCAPE_CHAR) {
107                out.write(b);
108            } else {
109                out.write(ESCAPE_CHAR); // Escape character
110                // Special escape
111                if (b >= 0 && b < FREE_CHARS) {
112                    out.write(CHAR_MAP[b]);
113                } else { // Normal escape
114                    final char[] tmp = Integer.toHexString(b).toCharArray();
115                    if (tmp.length == 1) {
116                        out.write('0');
117                        out.write(tmp[0]);
118                    } else {
119                        out.write(tmp[0]);
120                        out.write(tmp[1]);
121                    }
122                }
123            }
124        }
125
126        @Override
127        public void write(final String str, final int off, final int len) throws IOException {
128            write(str.toCharArray(), off, len);
129        }
130    }
131
132    /*
133     * How many chars have been consumed during parsing in typeSignatureToString(). Read by methodSignatureToString(). Set
134     * by side effect, but only internally.
135     */
136    private static final ThreadLocal<Integer> CONSUMER_CHARS = ThreadLocal.withInitial(() -> Integer.valueOf(0));
137
138    /*
139     * The `WIDE' instruction is used in the byte code to allow 16-bit wide indices for local variables. This opcode
140     * precedes an `ILOAD', e.g.. The opcode immediately following takes an extra byte which is combined with the following
141     * byte to form a 16-bit value.
142     */
143    private static boolean wide;
144
145    // A-Z, g-z, _, $
146    private static final int FREE_CHARS = 48;
147
148    private static final int[] CHAR_MAP = new int[FREE_CHARS];
149
150    private static final int[] MAP_CHAR = new int[256]; // Reverse map
151
152    private static final char ESCAPE_CHAR = '$';
153
154    static {
155        int j = 0;
156        for (int i = 'A'; i <= 'Z'; i++) {
157            CHAR_MAP[j] = i;
158            MAP_CHAR[i] = j;
159            j++;
160        }
161        for (int i = 'g'; i <= 'z'; i++) {
162            CHAR_MAP[j] = i;
163            MAP_CHAR[i] = j;
164            j++;
165        }
166        CHAR_MAP[j] = '$';
167        MAP_CHAR['$'] = j;
168        j++;
169        CHAR_MAP[j] = '_';
170        MAP_CHAR['_'] = j;
171    }
172
173    /**
174     * Convert bit field of flags into string such as `static final'.
175     *
176     * @param accessFlags Access flags
177     * @return String representation of flags
178     */
179    public static String accessToString(final int accessFlags) {
180        return accessToString(accessFlags, false);
181    }
182
183    /**
184     * Convert bit field of flags into string such as `static final'.
185     *
186     * Special case: Classes compiled with new compilers and with the `ACC_SUPER' flag would be said to be "synchronized".
187     * This is because SUN used the same value for the flags `ACC_SUPER' and `ACC_SYNCHRONIZED'.
188     *
189     * @param accessFlags Access flags
190     * @param forClass access flags are for class qualifiers ?
191     * @return String representation of flags
192     */
193    public static String accessToString(final int accessFlags, final boolean forClass) {
194        final StringBuilder buf = new StringBuilder();
195        int p = 0;
196        for (int i = 0; p < Const.MAX_ACC_FLAG_I; i++) { // Loop through known flags
197            p = pow2(i);
198            if ((accessFlags & p) != 0) {
199                /*
200                 * Special case: Classes compiled with new compilers and with the `ACC_SUPER' flag would be said to be "synchronized".
201                 * This is because SUN used the same value for the flags `ACC_SUPER' and `ACC_SYNCHRONIZED'.
202                 */
203                if (forClass && (p == Const.ACC_SUPER || p == Const.ACC_INTERFACE)) {
204                    continue;
205                }
206                buf.append(Const.getAccessName(i)).append(" ");
207            }
208        }
209        return buf.toString().trim();
210    }
211
212    /**
213     * Convert (signed) byte to (unsigned) short value, i.e., all negative values become positive.
214     */
215    private static short byteToShort(final byte b) {
216        return b < 0 ? (short) (256 + b) : (short) b;
217    }
218
219    /**
220     * @param accessFlags the class flags
221     *
222     * @return "class" or "interface", depending on the ACC_INTERFACE flag
223     */
224    public static String classOrInterface(final int accessFlags) {
225        return (accessFlags & Const.ACC_INTERFACE) != 0 ? "interface" : "class";
226    }
227
228    /**
229     * @return `flag' with bit `i' set to 0
230     */
231    public static int clearBit(final int flag, final int i) {
232        final int bit = pow2(i);
233        return (flag & bit) == 0 ? flag : flag ^ bit;
234    }
235
236    public static String codeToString(final byte[] code, final ConstantPool constantPool, final int index, final int length) {
237        return codeToString(code, constantPool, index, length, true);
238    }
239
240    /**
241     * Disassemble a byte array of JVM byte codes starting from code line `index' and return the disassembled string
242     * representation. Decode only `num' opcodes (including their operands), use -1 if you want to decompile everything.
243     *
244     * @param code byte code array
245     * @param constantPool Array of constants
246     * @param index offset in `code' array <EM>(number of opcodes, not bytes!)</EM>
247     * @param length number of opcodes to decompile, -1 for all
248     * @param verbose be verbose, e.g. print constant pool index
249     * @return String representation of byte codes
250     */
251    public static String codeToString(final byte[] code, final ConstantPool constantPool, final int index, final int length, final boolean verbose) {
252        final StringBuilder buf = new StringBuilder(code.length * 20); // Should be sufficient // CHECKSTYLE IGNORE MagicNumber
253        try (ByteSequence stream = new ByteSequence(code)) {
254            for (int i = 0; i < index; i++) {
255                codeToString(stream, constantPool, verbose);
256            }
257            for (int i = 0; stream.available() > 0; i++) {
258                if (length < 0 || i < length) {
259                    final String indices = fillup(stream.getIndex() + ":", 6, true, ' ');
260                    buf.append(indices).append(codeToString(stream, constantPool, verbose)).append('\n');
261                }
262            }
263        } catch (final IOException e) {
264            throw new ClassFormatException("Byte code error: " + buf.toString(), e);
265        }
266        return buf.toString();
267    }
268
269    public static String codeToString(final ByteSequence bytes, final ConstantPool constantPool) throws IOException {
270        return codeToString(bytes, constantPool, true);
271    }
272
273    /**
274     * Disassemble a stream of byte codes and return the string representation.
275     *
276     * @param bytes stream of bytes
277     * @param constantPool Array of constants
278     * @param verbose be verbose, e.g. print constant pool index
279     * @return String representation of byte code
280     *
281     * @throws IOException if a failure from reading from the bytes argument occurs
282     */
283    public static String codeToString(final ByteSequence bytes, final ConstantPool constantPool, final boolean verbose) throws IOException {
284        final short opcode = (short) bytes.readUnsignedByte();
285        int defaultOffset = 0;
286        int low;
287        int high;
288        int npairs;
289        int index;
290        int vindex;
291        int constant;
292        int[] match;
293        int[] jumpTable;
294        int noPadBytes = 0;
295        int offset;
296        final StringBuilder buf = new StringBuilder(Const.getOpcodeName(opcode));
297        /*
298         * Special case: Skip (0-3) padding bytes, i.e., the following bytes are 4-byte-aligned
299         */
300        if (opcode == Const.TABLESWITCH || opcode == Const.LOOKUPSWITCH) {
301            final int remainder = bytes.getIndex() % 4;
302            noPadBytes = remainder == 0 ? 0 : 4 - remainder;
303            for (int i = 0; i < noPadBytes; i++) {
304                byte b;
305                if ((b = bytes.readByte()) != 0) {
306                    System.err.println("Warning: Padding byte != 0 in " + Const.getOpcodeName(opcode) + ":" + b);
307                }
308            }
309            // Both cases have a field default_offset in common
310            defaultOffset = bytes.readInt();
311        }
312        switch (opcode) {
313        /*
314         * Table switch has variable length arguments.
315         */
316        case Const.TABLESWITCH:
317            low = bytes.readInt();
318            high = bytes.readInt();
319            offset = bytes.getIndex() - 12 - noPadBytes - 1;
320            defaultOffset += offset;
321            buf.append("\tdefault = ").append(defaultOffset).append(", low = ").append(low).append(", high = ").append(high).append("(");
322            jumpTable = new int[high - low + 1];
323            for (int i = 0; i < jumpTable.length; i++) {
324                jumpTable[i] = offset + bytes.readInt();
325                buf.append(jumpTable[i]);
326                if (i < jumpTable.length - 1) {
327                    buf.append(", ");
328                }
329            }
330            buf.append(")");
331            break;
332        /*
333         * Lookup switch has variable length arguments.
334         */
335        case Const.LOOKUPSWITCH: {
336            npairs = bytes.readInt();
337            offset = bytes.getIndex() - 8 - noPadBytes - 1;
338            match = new int[npairs];
339            jumpTable = new int[npairs];
340            defaultOffset += offset;
341            buf.append("\tdefault = ").append(defaultOffset).append(", npairs = ").append(npairs).append(" (");
342            for (int i = 0; i < npairs; i++) {
343                match[i] = bytes.readInt();
344                jumpTable[i] = offset + bytes.readInt();
345                buf.append("(").append(match[i]).append(", ").append(jumpTable[i]).append(")");
346                if (i < npairs - 1) {
347                    buf.append(", ");
348                }
349            }
350            buf.append(")");
351        }
352            break;
353        /*
354         * Two address bytes + offset from start of byte stream form the jump target
355         */
356        case Const.GOTO:
357        case Const.IFEQ:
358        case Const.IFGE:
359        case Const.IFGT:
360        case Const.IFLE:
361        case Const.IFLT:
362        case Const.JSR:
363        case Const.IFNE:
364        case Const.IFNONNULL:
365        case Const.IFNULL:
366        case Const.IF_ACMPEQ:
367        case Const.IF_ACMPNE:
368        case Const.IF_ICMPEQ:
369        case Const.IF_ICMPGE:
370        case Const.IF_ICMPGT:
371        case Const.IF_ICMPLE:
372        case Const.IF_ICMPLT:
373        case Const.IF_ICMPNE:
374            buf.append("\t\t#").append(bytes.getIndex() - 1 + bytes.readShort());
375            break;
376        /*
377         * 32-bit wide jumps
378         */
379        case Const.GOTO_W:
380        case Const.JSR_W:
381            buf.append("\t\t#").append(bytes.getIndex() - 1 + bytes.readInt());
382            break;
383        /*
384         * Index byte references local variable (register)
385         */
386        case Const.ALOAD:
387        case Const.ASTORE:
388        case Const.DLOAD:
389        case Const.DSTORE:
390        case Const.FLOAD:
391        case Const.FSTORE:
392        case Const.ILOAD:
393        case Const.ISTORE:
394        case Const.LLOAD:
395        case Const.LSTORE:
396        case Const.RET:
397            if (wide) {
398                vindex = bytes.readUnsignedShort();
399                wide = false; // Clear flag
400            } else {
401                vindex = bytes.readUnsignedByte();
402            }
403            buf.append("\t\t%").append(vindex);
404            break;
405        /*
406         * Remember wide byte which is used to form a 16-bit address in the following instruction. Relies on that the method is
407         * called again with the following opcode.
408         */
409        case Const.WIDE:
410            wide = true;
411            buf.append("\t(wide)");
412            break;
413        /*
414         * Array of basic type.
415         */
416        case Const.NEWARRAY:
417            buf.append("\t\t<").append(Const.getTypeName(bytes.readByte())).append(">");
418            break;
419        /*
420         * Access object/class fields.
421         */
422        case Const.GETFIELD:
423        case Const.GETSTATIC:
424        case Const.PUTFIELD:
425        case Const.PUTSTATIC:
426            index = bytes.readUnsignedShort();
427            buf.append("\t\t").append(constantPool.constantToString(index, Const.CONSTANT_Fieldref)).append(verbose ? " (" + index + ")" : "");
428            break;
429        /*
430         * Operands are references to classes in constant pool
431         */
432        case Const.NEW:
433        case Const.CHECKCAST:
434            buf.append("\t");
435            //$FALL-THROUGH$
436        case Const.INSTANCEOF:
437            index = bytes.readUnsignedShort();
438            buf.append("\t<").append(constantPool.constantToString(index, Const.CONSTANT_Class)).append(">").append(verbose ? " (" + index + ")" : "");
439            break;
440        /*
441         * Operands are references to methods in constant pool
442         */
443        case Const.INVOKESPECIAL:
444        case Const.INVOKESTATIC:
445            index = bytes.readUnsignedShort();
446            final Constant c = constantPool.getConstant(index);
447            // With Java8 operand may be either a CONSTANT_Methodref
448            // or a CONSTANT_InterfaceMethodref. (markro)
449            buf.append("\t").append(constantPool.constantToString(index, c.getTag())).append(verbose ? " (" + index + ")" : "");
450            break;
451        case Const.INVOKEVIRTUAL:
452            index = bytes.readUnsignedShort();
453            buf.append("\t").append(constantPool.constantToString(index, Const.CONSTANT_Methodref)).append(verbose ? " (" + index + ")" : "");
454            break;
455        case Const.INVOKEINTERFACE:
456            index = bytes.readUnsignedShort();
457            final int nargs = bytes.readUnsignedByte(); // historical, redundant
458            buf.append("\t").append(constantPool.constantToString(index, Const.CONSTANT_InterfaceMethodref)).append(verbose ? " (" + index + ")\t" : "")
459                .append(nargs).append("\t").append(bytes.readUnsignedByte()); // Last byte is a reserved space
460            break;
461        case Const.INVOKEDYNAMIC:
462            index = bytes.readUnsignedShort();
463            buf.append("\t").append(constantPool.constantToString(index, Const.CONSTANT_InvokeDynamic)).append(verbose ? " (" + index + ")\t" : "")
464                .append(bytes.readUnsignedByte()) // Thrid byte is a reserved space
465                .append(bytes.readUnsignedByte()); // Last byte is a reserved space
466            break;
467        /*
468         * Operands are references to items in constant pool
469         */
470        case Const.LDC_W:
471        case Const.LDC2_W:
472            index = bytes.readUnsignedShort();
473            buf.append("\t\t").append(constantPool.constantToString(index, constantPool.getConstant(index).getTag()))
474                .append(verbose ? " (" + index + ")" : "");
475            break;
476        case Const.LDC:
477            index = bytes.readUnsignedByte();
478            buf.append("\t\t").append(constantPool.constantToString(index, constantPool.getConstant(index).getTag()))
479                .append(verbose ? " (" + index + ")" : "");
480            break;
481        /*
482         * Array of references.
483         */
484        case Const.ANEWARRAY:
485            index = bytes.readUnsignedShort();
486            buf.append("\t\t<").append(compactClassName(constantPool.getConstantString(index, Const.CONSTANT_Class), false)).append(">")
487                .append(verbose ? " (" + index + ")" : "");
488            break;
489        /*
490         * Multidimensional array of references.
491         */
492        case Const.MULTIANEWARRAY: {
493            index = bytes.readUnsignedShort();
494            final int dimensions = bytes.readUnsignedByte();
495            buf.append("\t<").append(compactClassName(constantPool.getConstantString(index, Const.CONSTANT_Class), false)).append(">\t").append(dimensions)
496                .append(verbose ? " (" + index + ")" : "");
497        }
498            break;
499        /*
500         * Increment local variable.
501         */
502        case Const.IINC:
503            if (wide) {
504                vindex = bytes.readUnsignedShort();
505                constant = bytes.readShort();
506                wide = false;
507            } else {
508                vindex = bytes.readUnsignedByte();
509                constant = bytes.readByte();
510            }
511            buf.append("\t\t%").append(vindex).append("\t").append(constant);
512            break;
513        default:
514            if (Const.getNoOfOperands(opcode) > 0) {
515                for (int i = 0; i < Const.getOperandTypeCount(opcode); i++) {
516                    buf.append("\t\t");
517                    switch (Const.getOperandType(opcode, i)) {
518                    case Const.T_BYTE:
519                        buf.append(bytes.readByte());
520                        break;
521                    case Const.T_SHORT:
522                        buf.append(bytes.readShort());
523                        break;
524                    case Const.T_INT:
525                        buf.append(bytes.readInt());
526                        break;
527                    default: // Never reached
528                        throw new IllegalStateException("Unreachable default case reached!");
529                    }
530                }
531            }
532        }
533        return buf.toString();
534    }
535
536    /**
537     * Shorten long class names, <em>java/lang/String</em> becomes <em>String</em>.
538     *
539     * @param str The long class name
540     * @return Compacted class name
541     */
542    public static String compactClassName(final String str) {
543        return compactClassName(str, true);
544    }
545
546    /**
547     * Shorten long class names, <em>java/lang/String</em> becomes <em>java.lang.String</em>, e.g.. If <em>chopit</em> is
548     * <em>true</em> the prefix <em>java.lang</em> is also removed.
549     *
550     * @param str The long class name
551     * @param chopit flag that determines whether chopping is executed or not
552     * @return Compacted class name
553     */
554    public static String compactClassName(final String str, final boolean chopit) {
555        return compactClassName(str, "java.lang.", chopit);
556    }
557
558    /**
559     * Shorten long class name <em>str</em>, i.e., chop off the <em>prefix</em>, if the class name starts with this string
560     * and the flag <em>chopit</em> is true. Slashes <em>/</em> are converted to dots <em>.</em>.
561     *
562     * @param str The long class name
563     * @param prefix The prefix the get rid off
564     * @param chopit flag that determines whether chopping is executed or not
565     * @return Compacted class name
566     */
567    public static String compactClassName(String str, final String prefix, final boolean chopit) {
568        final int len = prefix.length();
569        str = pathToPackage(str); // Is `/' on all systems, even DOS
570        // If string starts with `prefix' and contains no further dots
571        if (chopit && str.startsWith(prefix) && str.substring(len).indexOf('.') == -1) {
572            str = str.substring(len);
573        }
574        return str;
575    }
576
577    /**
578     * Converts a path to a package name.
579     *
580     * @param str the source path.
581     * @return a package name.
582     * @since 6.6.0
583     */
584    public static String pathToPackage(final String str) {
585        return str.replace('/', '.');
586    }
587
588    /**
589     * Escape all occurrences of newline chars '\n', quotes \", etc.
590     */
591    public static String convertString(final String label) {
592        final char[] ch = label.toCharArray();
593        final StringBuilder buf = new StringBuilder();
594        for (final char element : ch) {
595            switch (element) {
596            case '\n':
597                buf.append("\\n");
598                break;
599            case '\r':
600                buf.append("\\r");
601                break;
602            case '\"':
603                buf.append("\\\"");
604                break;
605            case '\'':
606                buf.append("\\'");
607                break;
608            case '\\':
609                buf.append("\\\\");
610                break;
611            default:
612                buf.append(element);
613                break;
614            }
615        }
616        return buf.toString();
617    }
618
619    private static int countBrackets(final String brackets) {
620        final char[] chars = brackets.toCharArray();
621        int count = 0;
622        boolean open = false;
623        for (final char c : chars) {
624            switch (c) {
625            case '[':
626                if (open) {
627                    throw new IllegalArgumentException("Illegally nested brackets:" + brackets);
628                }
629                open = true;
630                break;
631            case ']':
632                if (!open) {
633                    throw new IllegalArgumentException("Illegally nested brackets:" + brackets);
634                }
635                open = false;
636                count++;
637                break;
638            default:
639                // Don't care
640                break;
641            }
642        }
643        if (open) {
644            throw new IllegalArgumentException("Illegally nested brackets:" + brackets);
645        }
646        return count;
647    }
648
649    /**
650     * Decode a string back to a byte array.
651     *
652     * @param s the string to convert
653     * @param uncompress use gzip to uncompress the stream of bytes
654     *
655     * @throws IOException if there's a gzip exception
656     */
657    public static byte[] decode(final String s, final boolean uncompress) throws IOException {
658        byte[] bytes;
659        try (JavaReader jr = new JavaReader(new CharArrayReader(s.toCharArray())); ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
660            int ch;
661            while ((ch = jr.read()) >= 0) {
662                bos.write(ch);
663            }
664            bytes = bos.toByteArray();
665        }
666        if (uncompress) {
667            final GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(bytes));
668            final byte[] tmp = new byte[bytes.length * 3]; // Rough estimate
669            int count = 0;
670            int b;
671            while ((b = gis.read()) >= 0) {
672                tmp[count++] = (byte) b;
673            }
674            bytes = Arrays.copyOf(tmp, count);
675        }
676        return bytes;
677    }
678
679    /**
680     * Encode byte array it into Java identifier string, i.e., a string that only contains the following characters: (a, ...
681     * z, A, ... Z, 0, ... 9, _, $). The encoding algorithm itself is not too clever: if the current byte's ASCII value
682     * already is a valid Java identifier part, leave it as it is. Otherwise it writes the escape character($) followed by:
683     *
684     * <ul>
685     * <li>the ASCII value as a hexadecimal string, if the value is not in the range 200..247</li>
686     * <li>a Java identifier char not used in a lowercase hexadecimal string, if the value is in the range 200..247</li>
687     * </ul>
688     *
689     * <p>
690     * This operation inflates the original byte array by roughly 40-50%
691     * </p>
692     *
693     * @param bytes the byte array to convert
694     * @param compress use gzip to minimize string
695     *
696     * @throws IOException if there's a gzip exception
697     */
698    public static String encode(byte[] bytes, final boolean compress) throws IOException {
699        if (compress) {
700            try (ByteArrayOutputStream baos = new ByteArrayOutputStream(); GZIPOutputStream gos = new GZIPOutputStream(baos)) {
701                gos.write(bytes, 0, bytes.length);
702                gos.close();
703                bytes = baos.toByteArray();
704            }
705        }
706        final CharArrayWriter caw = new CharArrayWriter();
707        try (JavaWriter jw = new JavaWriter(caw)) {
708            for (final byte b : bytes) {
709                final int in = b & 0x000000ff; // Normalize to unsigned
710                jw.write(in);
711            }
712        }
713        return caw.toString();
714    }
715
716    static boolean equals(final byte[] a, final byte[] b) {
717        int size;
718        if ((size = a.length) != b.length) {
719            return false;
720        }
721        for (int i = 0; i < size; i++) {
722            if (a[i] != b[i]) {
723                return false;
724            }
725        }
726        return true;
727    }
728
729    /**
730     * Fillup char with up to length characters with char `fill' and justify it left or right.
731     *
732     * @param str string to format
733     * @param length length of desired string
734     * @param leftJustify format left or right
735     * @param fill fill character
736     * @return formatted string
737     */
738    public static String fillup(final String str, final int length, final boolean leftJustify, final char fill) {
739        final int len = length - str.length();
740        final char[] buf = new char[Math.max(len, 0)];
741        Arrays.fill(buf, fill);
742        if (leftJustify) {
743            return str + new String(buf);
744        }
745        return new String(buf) + str;
746    }
747
748    /**
749     * WARNING:
750     *
751     * There is some nomenclature confusion through much of the BCEL code base with respect to the terms Descriptor and
752     * Signature. For the offical definitions see:
753     *
754     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.3"> Descriptors in The Java
755     *      Virtual Machine Specification</a>
756     *
757     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.9.1"> Signatures in The Java
758     *      Virtual Machine Specification</a>
759     *
760     *      In brief, a descriptor is a string representing the type of a field or method. Signatures are similar, but more
761     *      complex. Signatures are used to encode declarations written in the Java programming language that use types
762     *      outside the type system of the Java Virtual Machine. They are used to describe the type of any class, interface,
763     *      constructor, method or field whose declaration uses type variables or parameterized types.
764     *
765     *      To parse a descriptor, call typeSignatureToString. To parse a signature, call signatureToString.
766     *
767     *      Note that if the signature string is a single, non-generic item, the call to signatureToString reduces to a call
768     *      to typeSignatureToString. Also note, that if you only wish to parse the first item in a longer signature string,
769     *      you should call typeSignatureToString directly.
770     */
771
772    /**
773     * Return a string for an integer justified left or right and filled up with `fill' characters if necessary.
774     *
775     * @param i integer to format
776     * @param length length of desired string
777     * @param leftJustify format left or right
778     * @param fill fill character
779     * @return formatted int
780     */
781    public static String format(final int i, final int length, final boolean leftJustify, final char fill) {
782        return fillup(Integer.toString(i), length, leftJustify, fill);
783    }
784
785    /**
786     * Parse Java type such as "char", or "java.lang.String[]" and return the signature in byte code format, e.g. "C" or
787     * "[Ljava/lang/String;" respectively.
788     *
789     * @param type Java type
790     * @return byte code signature
791     */
792    public static String getSignature(String type) {
793        final StringBuilder buf = new StringBuilder();
794        final char[] chars = type.toCharArray();
795        boolean charFound = false;
796        boolean delim = false;
797        int index = -1;
798        loop: for (int i = 0; i < chars.length; i++) {
799            switch (chars[i]) {
800            case ' ':
801            case '\t':
802            case '\n':
803            case '\r':
804            case '\f':
805                if (charFound) {
806                    delim = true;
807                }
808                break;
809            case '[':
810                if (!charFound) {
811                    throw new IllegalArgumentException("Illegal type: " + type);
812                }
813                index = i;
814                break loop;
815            default:
816                charFound = true;
817                if (!delim) {
818                    buf.append(chars[i]);
819                }
820            }
821        }
822        int brackets = 0;
823        if (index > 0) {
824            brackets = countBrackets(type.substring(index));
825        }
826        type = buf.toString();
827        buf.setLength(0);
828        for (int i = 0; i < brackets; i++) {
829            buf.append('[');
830        }
831        boolean found = false;
832        for (int i = Const.T_BOOLEAN; i <= Const.T_VOID && !found; i++) {
833            if (Const.getTypeName(i).equals(type)) {
834                found = true;
835                buf.append(Const.getShortTypeName(i));
836            }
837        }
838        if (!found) {
839            buf.append('L').append(type.replace('.', '/')).append(';');
840        }
841        return buf.toString();
842    }
843
844    /**
845     * @param ch the character to test if it's part of an identifier
846     *
847     * @return true, if character is one of (a, ... z, A, ... Z, 0, ... 9, _)
848     */
849    public static boolean isJavaIdentifierPart(final char ch) {
850        return ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9' || ch == '_';
851    }
852
853    /**
854     * @return true, if bit `i' in `flag' is set
855     */
856    public static boolean isSet(final int flag, final int i) {
857        return (flag & pow2(i)) != 0;
858    }
859
860    /**
861     * Converts argument list portion of method signature to string with all class names compacted.
862     *
863     * @param signature Method signature
864     * @return String Array of argument types
865     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
866     */
867    public static String[] methodSignatureArgumentTypes(final String signature) throws ClassFormatException {
868        return methodSignatureArgumentTypes(signature, true);
869    }
870
871    /**
872     * Converts argument list portion of method signature to string.
873     *
874     * @param signature Method signature
875     * @param chopit flag that determines whether chopping is executed or not
876     * @return String Array of argument types
877     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
878     */
879    public static String[] methodSignatureArgumentTypes(final String signature, final boolean chopit) throws ClassFormatException {
880        final List<String> vec = new ArrayList<>();
881        int index;
882        try {
883            // Skip any type arguments to read argument declarations between `(' and `)'
884            index = signature.indexOf('(') + 1;
885            if (index <= 0) {
886                throw new ClassFormatException("Invalid method signature: " + signature);
887            }
888            while (signature.charAt(index) != ')') {
889                vec.add(typeSignatureToString(signature.substring(index), chopit));
890                // corrected concurrent private static field acess
891                index += unwrap(CONSUMER_CHARS); // update position
892            }
893        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
894            throw new ClassFormatException("Invalid method signature: " + signature, e);
895        }
896        return vec.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
897    }
898
899    /**
900     * Converts return type portion of method signature to string with all class names compacted.
901     *
902     * @param signature Method signature
903     * @return String representation of method return type
904     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
905     */
906    public static String methodSignatureReturnType(final String signature) throws ClassFormatException {
907        return methodSignatureReturnType(signature, true);
908    }
909
910    /**
911     * Converts return type portion of method signature to string.
912     *
913     * @param signature Method signature
914     * @param chopit flag that determines whether chopping is executed or not
915     * @return String representation of method return type
916     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
917     */
918    public static String methodSignatureReturnType(final String signature, final boolean chopit) throws ClassFormatException {
919        int index;
920        String type;
921        try {
922            // Read return type after `)'
923            index = signature.lastIndexOf(')') + 1;
924            if (index <= 0) {
925                throw new ClassFormatException("Invalid method signature: " + signature);
926            }
927            type = typeSignatureToString(signature.substring(index), chopit);
928        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
929            throw new ClassFormatException("Invalid method signature: " + signature, e);
930        }
931        return type;
932    }
933
934    /**
935     * Converts method signature to string with all class names compacted.
936     *
937     * @param signature to convert
938     * @param name of method
939     * @param access flags of method
940     * @return Human readable signature
941     */
942    public static String methodSignatureToString(final String signature, final String name, final String access) {
943        return methodSignatureToString(signature, name, access, true);
944    }
945
946    /**
947     * Converts method signature to string.
948     *
949     * @param signature to convert
950     * @param name of method
951     * @param access flags of method
952     * @param chopit flag that determines whether chopping is executed or not
953     * @return Human readable signature
954     */
955    public static String methodSignatureToString(final String signature, final String name, final String access, final boolean chopit) {
956        return methodSignatureToString(signature, name, access, chopit, null);
957    }
958
959    /**
960     * This method converts a method signature string into a Java type declaration like `void main(String[])' and throws a
961     * `ClassFormatException' when the parsed type is invalid.
962     *
963     * @param signature Method signature
964     * @param name Method name
965     * @param access Method access rights
966     * @param chopit flag that determines whether chopping is executed or not
967     * @param vars the LocalVariableTable for the method
968     * @return Java type declaration
969     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
970     */
971    public static String methodSignatureToString(final String signature, final String name, final String access, final boolean chopit,
972        final LocalVariableTable vars) throws ClassFormatException {
973        final StringBuilder buf = new StringBuilder("(");
974        String type;
975        int index;
976        int varIndex = access.contains("static") ? 0 : 1;
977        try {
978            // Skip any type arguments to read argument declarations between `(' and `)'
979            index = signature.indexOf('(') + 1;
980            if (index <= 0) {
981                throw new ClassFormatException("Invalid method signature: " + signature);
982            }
983            while (signature.charAt(index) != ')') {
984                final String paramType = typeSignatureToString(signature.substring(index), chopit);
985                buf.append(paramType);
986                if (vars != null) {
987                    final LocalVariable l = vars.getLocalVariable(varIndex, 0);
988                    if (l != null) {
989                        buf.append(" ").append(l.getName());
990                    }
991                } else {
992                    buf.append(" arg").append(varIndex);
993                }
994                if ("double".equals(paramType) || "long".equals(paramType)) {
995                    varIndex += 2;
996                } else {
997                    varIndex++;
998                }
999                buf.append(", ");
1000                // corrected concurrent private static field acess
1001                index += unwrap(CONSUMER_CHARS); // update position
1002            }
1003            index++; // update position
1004            // Read return type after `)'
1005            type = typeSignatureToString(signature.substring(index), chopit);
1006        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
1007            throw new ClassFormatException("Invalid method signature: " + signature, e);
1008        }
1009        // ignore any throws information in the signature
1010        if (buf.length() > 1) {
1011            buf.setLength(buf.length() - 2);
1012        }
1013        buf.append(")");
1014        return access + (!access.isEmpty() ? " " : "") + // May be an empty string
1015            type + " " + name + buf.toString();
1016    }
1017
1018    /**
1019     * Converts string containing the method return and argument types to a byte code method signature.
1020     *
1021     * @param ret Return type of method
1022     * @param argv Types of method arguments
1023     * @return Byte code representation of method signature
1024     *
1025     * @throws ClassFormatException if the signature is for Void
1026     */
1027    public static String methodTypeToSignature(final String ret, final String[] argv) throws ClassFormatException {
1028        final StringBuilder buf = new StringBuilder("(");
1029        String str;
1030        if (argv != null) {
1031            for (final String element : argv) {
1032                str = getSignature(element);
1033                if (str.endsWith("V")) {
1034                    throw new ClassFormatException("Invalid type: " + element);
1035                }
1036                buf.append(str);
1037            }
1038        }
1039        str = getSignature(ret);
1040        buf.append(")").append(str);
1041        return buf.toString();
1042    }
1043
1044    private static int pow2(final int n) {
1045        return 1 << n;
1046    }
1047
1048    public static String printArray(final Object[] obj) {
1049        return printArray(obj, true);
1050    }
1051
1052    public static String printArray(final Object[] obj, final boolean braces) {
1053        return printArray(obj, braces, false);
1054    }
1055
1056    public static String printArray(final Object[] obj, final boolean braces, final boolean quote) {
1057        if (obj == null) {
1058            return null;
1059        }
1060        final StringBuilder buf = new StringBuilder();
1061        if (braces) {
1062            buf.append('{');
1063        }
1064        for (int i = 0; i < obj.length; i++) {
1065            if (obj[i] != null) {
1066                buf.append(quote ? "\"" : "").append(obj[i]).append(quote ? "\"" : "");
1067            } else {
1068                buf.append("null");
1069            }
1070            if (i < obj.length - 1) {
1071                buf.append(", ");
1072            }
1073        }
1074        if (braces) {
1075            buf.append('}');
1076        }
1077        return buf.toString();
1078    }
1079
1080    public static void printArray(final PrintStream out, final Object[] obj) {
1081        out.println(printArray(obj, true));
1082    }
1083
1084    public static void printArray(final PrintWriter out, final Object[] obj) {
1085        out.println(printArray(obj, true));
1086    }
1087
1088    /**
1089     * Replace all occurrences of <em>old</em> in <em>str</em> with <em>new</em>.
1090     *
1091     * @param str String to permute
1092     * @param old String to be replaced
1093     * @param new_ Replacement string
1094     * @return new String object
1095     */
1096    public static String replace(String str, final String old, final String new_) {
1097        int index;
1098        int oldIndex;
1099        try {
1100            if (str.contains(old)) { // `old' found in str
1101                final StringBuilder buf = new StringBuilder();
1102                oldIndex = 0; // String start offset
1103                // While we have something to replace
1104                while ((index = str.indexOf(old, oldIndex)) != -1) {
1105                    buf.append(str, oldIndex, index); // append prefix
1106                    buf.append(new_); // append replacement
1107                    oldIndex = index + old.length(); // Skip `old'.length chars
1108                }
1109                buf.append(str.substring(oldIndex)); // append rest of string
1110                str = buf.toString();
1111            }
1112        } catch (final StringIndexOutOfBoundsException e) { // Should not occur
1113            System.err.println(e);
1114        }
1115        return str;
1116    }
1117
1118    /**
1119     * Map opcode names to opcode numbers. E.g., return Constants.ALOAD for "aload"
1120     */
1121    public static short searchOpcode(String name) {
1122        name = name.toLowerCase(Locale.ENGLISH);
1123        for (short i = 0; i < Const.OPCODE_NAMES_LENGTH; i++) {
1124            if (Const.getOpcodeName(i).equals(name)) {
1125                return i;
1126            }
1127        }
1128        return -1;
1129    }
1130
1131    /**
1132     * @return `flag' with bit `i' set to 1
1133     */
1134    public static int setBit(final int flag, final int i) {
1135        return flag | pow2(i);
1136    }
1137
1138    /**
1139     * Converts a signature to a string with all class names compacted. Class, Method and Type signatures are supported.
1140     * Enum and Interface signatures are not supported.
1141     *
1142     * @param signature signature to convert
1143     * @return String containg human readable signature
1144     */
1145    public static String signatureToString(final String signature) {
1146        return signatureToString(signature, true);
1147    }
1148
1149    /**
1150     * Converts a signature to a string. Class, Method and Type signatures are supported. Enum and Interface signatures are
1151     * not supported.
1152     *
1153     * @param signature signature to convert
1154     * @param chopit flag that determines whether chopping is executed or not
1155     * @return String containg human readable signature
1156     */
1157    public static String signatureToString(final String signature, final boolean chopit) {
1158        String type = "";
1159        String typeParams = "";
1160        int index = 0;
1161        if (signature.charAt(0) == '<') {
1162            // we have type paramters
1163            typeParams = typeParamTypesToString(signature, chopit);
1164            index += unwrap(CONSUMER_CHARS); // update position
1165        }
1166        if (signature.charAt(index) == '(') {
1167            // We have a Method signature.
1168            // add types of arguments
1169            type = typeParams + typeSignaturesToString(signature.substring(index), chopit, ')');
1170            index += unwrap(CONSUMER_CHARS); // update position
1171            // add return type
1172            type = type + typeSignatureToString(signature.substring(index), chopit);
1173            index += unwrap(CONSUMER_CHARS); // update position
1174            // ignore any throws information in the signature
1175            return type;
1176        }
1177        // Could be Class or Type...
1178        type = typeSignatureToString(signature.substring(index), chopit);
1179        index += unwrap(CONSUMER_CHARS); // update position
1180        if (typeParams.isEmpty() && index == signature.length()) {
1181            // We have a Type signature.
1182            return type;
1183        }
1184        // We have a Class signature.
1185        final StringBuilder typeClass = new StringBuilder(typeParams);
1186        typeClass.append(" extends ");
1187        typeClass.append(type);
1188        if (index < signature.length()) {
1189            typeClass.append(" implements ");
1190            typeClass.append(typeSignatureToString(signature.substring(index), chopit));
1191            index += unwrap(CONSUMER_CHARS); // update position
1192        }
1193        while (index < signature.length()) {
1194            typeClass.append(", ");
1195            typeClass.append(typeSignatureToString(signature.substring(index), chopit));
1196            index += unwrap(CONSUMER_CHARS); // update position
1197        }
1198        return typeClass.toString();
1199    }
1200
1201    /**
1202     * Convert bytes into hexadecimal string
1203     *
1204     * @param bytes an array of bytes to convert to hexadecimal
1205     *
1206     * @return bytes as hexadecimal string, e.g. 00 fa 12 ...
1207     */
1208    public static String toHexString(final byte[] bytes) {
1209        final StringBuilder buf = new StringBuilder();
1210        for (int i = 0; i < bytes.length; i++) {
1211            final short b = byteToShort(bytes[i]);
1212            final String hex = Integer.toHexString(b);
1213            if (b < 0x10) {
1214                buf.append('0');
1215            }
1216            buf.append(hex);
1217            if (i < bytes.length - 1) {
1218                buf.append(' ');
1219            }
1220        }
1221        return buf.toString();
1222    }
1223
1224    /**
1225     * Return type of method signature as a byte value as defined in <em>Constants</em>
1226     *
1227     * @param signature in format described above
1228     * @return type of method signature
1229     * @see Const
1230     *
1231     * @throws ClassFormatException if signature is not a method signature
1232     */
1233    public static byte typeOfMethodSignature(final String signature) throws ClassFormatException {
1234        int index;
1235        try {
1236            if (signature.charAt(0) != '(') {
1237                throw new ClassFormatException("Invalid method signature: " + signature);
1238            }
1239            index = signature.lastIndexOf(')') + 1;
1240            return typeOfSignature(signature.substring(index));
1241        } catch (final StringIndexOutOfBoundsException e) {
1242            throw new ClassFormatException("Invalid method signature: " + signature, e);
1243        }
1244    }
1245
1246    /**
1247     * Return type of signature as a byte value as defined in <em>Constants</em>
1248     *
1249     * @param signature in format described above
1250     * @return type of signature
1251     * @see Const
1252     *
1253     * @throws ClassFormatException if signature isn't a known type
1254     */
1255    public static byte typeOfSignature(final String signature) throws ClassFormatException {
1256        try {
1257            switch (signature.charAt(0)) {
1258            case 'B':
1259                return Const.T_BYTE;
1260            case 'C':
1261                return Const.T_CHAR;
1262            case 'D':
1263                return Const.T_DOUBLE;
1264            case 'F':
1265                return Const.T_FLOAT;
1266            case 'I':
1267                return Const.T_INT;
1268            case 'J':
1269                return Const.T_LONG;
1270            case 'L':
1271            case 'T':
1272                return Const.T_REFERENCE;
1273            case '[':
1274                return Const.T_ARRAY;
1275            case 'V':
1276                return Const.T_VOID;
1277            case 'Z':
1278                return Const.T_BOOLEAN;
1279            case 'S':
1280                return Const.T_SHORT;
1281            case '!':
1282            case '+':
1283            case '*':
1284                return typeOfSignature(signature.substring(1));
1285            default:
1286                throw new ClassFormatException("Invalid method signature: " + signature);
1287            }
1288        } catch (final StringIndexOutOfBoundsException e) {
1289            throw new ClassFormatException("Invalid method signature: " + signature, e);
1290        }
1291    }
1292
1293    /**
1294     * Converts a type parameter list signature to a string.
1295     *
1296     * @param signature signature to convert
1297     * @param chopit flag that determines whether chopping is executed or not
1298     * @return String containg human readable signature
1299     */
1300    private static String typeParamTypesToString(final String signature, final boolean chopit) {
1301        // The first character is guranteed to be '<'
1302        final StringBuilder typeParams = new StringBuilder("<");
1303        int index = 1; // skip the '<'
1304        // get the first TypeParameter
1305        typeParams.append(typeParamTypeToString(signature.substring(index), chopit));
1306        index += unwrap(CONSUMER_CHARS); // update position
1307        // are there more TypeParameters?
1308        while (signature.charAt(index) != '>') {
1309            typeParams.append(", ");
1310            typeParams.append(typeParamTypeToString(signature.substring(index), chopit));
1311            index += unwrap(CONSUMER_CHARS); // update position
1312        }
1313        wrap(CONSUMER_CHARS, index + 1); // account for the '>' char
1314        return typeParams.append(">").toString();
1315    }
1316
1317    /**
1318     * Converts a type parameter signature to a string.
1319     *
1320     * @param signature signature to convert
1321     * @param chopit flag that determines whether chopping is executed or not
1322     * @return String containg human readable signature
1323     */
1324    private static String typeParamTypeToString(final String signature, final boolean chopit) {
1325        int index = signature.indexOf(':');
1326        if (index <= 0) {
1327            throw new ClassFormatException("Invalid type parameter signature: " + signature);
1328        }
1329        // get the TypeParameter identifier
1330        final StringBuilder typeParam = new StringBuilder(signature.substring(0, index));
1331        index++; // account for the ':'
1332        if (signature.charAt(index) != ':') {
1333            // we have a class bound
1334            typeParam.append(" extends ");
1335            typeParam.append(typeSignatureToString(signature.substring(index), chopit));
1336            index += unwrap(CONSUMER_CHARS); // update position
1337        }
1338        // look for interface bounds
1339        while (signature.charAt(index) == ':') {
1340            index++; // skip over the ':'
1341            typeParam.append(" & ");
1342            typeParam.append(typeSignatureToString(signature.substring(index), chopit));
1343            index += unwrap(CONSUMER_CHARS); // update position
1344        }
1345        wrap(CONSUMER_CHARS, index);
1346        return typeParam.toString();
1347    }
1348
1349    /**
1350     * Converts a list of type signatures to a string.
1351     *
1352     * @param signature signature to convert
1353     * @param chopit flag that determines whether chopping is executed or not
1354     * @param term character indicating the end of the list
1355     * @return String containg human readable signature
1356     */
1357    private static String typeSignaturesToString(final String signature, final boolean chopit, final char term) {
1358        // The first character will be an 'open' that matches the 'close' contained in term.
1359        final StringBuilder typeList = new StringBuilder(signature.substring(0, 1));
1360        int index = 1; // skip the 'open' character
1361        // get the first Type in the list
1362        if (signature.charAt(index) != term) {
1363            typeList.append(typeSignatureToString(signature.substring(index), chopit));
1364            index += unwrap(CONSUMER_CHARS); // update position
1365        }
1366        // are there more types in the list?
1367        while (signature.charAt(index) != term) {
1368            typeList.append(", ");
1369            typeList.append(typeSignatureToString(signature.substring(index), chopit));
1370            index += unwrap(CONSUMER_CHARS); // update position
1371        }
1372        wrap(CONSUMER_CHARS, index + 1); // account for the term char
1373        return typeList.append(term).toString();
1374    }
1375
1376    /**
1377     *
1378     * This method converts a type signature string into a Java type declaration such as `String[]' and throws a
1379     * `ClassFormatException' when the parsed type is invalid.
1380     *
1381     * @param signature type signature
1382     * @param chopit flag that determines whether chopping is executed or not
1383     * @return string containing human readable type signature
1384     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
1385     * @since 6.4.0
1386     */
1387    public static String typeSignatureToString(final String signature, final boolean chopit) throws ClassFormatException {
1388        // corrected concurrent private static field acess
1389        wrap(CONSUMER_CHARS, 1); // This is the default, read just one char like `B'
1390        try {
1391            switch (signature.charAt(0)) {
1392            case 'B':
1393                return "byte";
1394            case 'C':
1395                return "char";
1396            case 'D':
1397                return "double";
1398            case 'F':
1399                return "float";
1400            case 'I':
1401                return "int";
1402            case 'J':
1403                return "long";
1404            case 'T': { // TypeVariableSignature
1405                final int index = signature.indexOf(';'); // Look for closing `;'
1406                if (index < 0) {
1407                    throw new ClassFormatException("Invalid type variable signature: " + signature);
1408                }
1409                // corrected concurrent private static field acess
1410                wrap(CONSUMER_CHARS, index + 1); // "Tblabla;" `T' and `;' are removed
1411                return compactClassName(signature.substring(1, index), chopit);
1412            }
1413            case 'L': { // Full class name
1414                // should this be a while loop? can there be more than
1415                // one generic clause? (markro)
1416                int fromIndex = signature.indexOf('<'); // generic type?
1417                if (fromIndex < 0) {
1418                    fromIndex = 0;
1419                } else {
1420                    fromIndex = signature.indexOf('>', fromIndex);
1421                    if (fromIndex < 0) {
1422                        throw new ClassFormatException("Invalid signature: " + signature);
1423                    }
1424                }
1425                final int index = signature.indexOf(';', fromIndex); // Look for closing `;'
1426                if (index < 0) {
1427                    throw new ClassFormatException("Invalid signature: " + signature);
1428                }
1429
1430                // check to see if there are any TypeArguments
1431                final int bracketIndex = signature.substring(0, index).indexOf('<');
1432                if (bracketIndex < 0) {
1433                    // just a class identifier
1434                    wrap(CONSUMER_CHARS, index + 1); // "Lblabla;" `L' and `;' are removed
1435                    return compactClassName(signature.substring(1, index), chopit);
1436                }
1437                // but make sure we are not looking past the end of the current item
1438                fromIndex = signature.indexOf(';');
1439                if (fromIndex < 0) {
1440                    throw new ClassFormatException("Invalid signature: " + signature);
1441                }
1442                if (fromIndex < bracketIndex) {
1443                    // just a class identifier
1444                    wrap(CONSUMER_CHARS, fromIndex + 1); // "Lblabla;" `L' and `;' are removed
1445                    return compactClassName(signature.substring(1, fromIndex), chopit);
1446                }
1447
1448                // we have TypeArguments; build up partial result
1449                // as we recurse for each TypeArgument
1450                final StringBuilder type = new StringBuilder(compactClassName(signature.substring(1, bracketIndex), chopit)).append("<");
1451                int consumedChars = bracketIndex + 1; // Shadows global var
1452
1453                // check for wildcards
1454                if (signature.charAt(consumedChars) == '+') {
1455                    type.append("? extends ");
1456                    consumedChars++;
1457                } else if (signature.charAt(consumedChars) == '-') {
1458                    type.append("? super ");
1459                    consumedChars++;
1460                }
1461
1462                // get the first TypeArgument
1463                if (signature.charAt(consumedChars) == '*') {
1464                    type.append("?");
1465                    consumedChars++;
1466                } else {
1467                    type.append(typeSignatureToString(signature.substring(consumedChars), chopit));
1468                    // update our consumed count by the number of characters the for type argument
1469                    consumedChars = unwrap(Utility.CONSUMER_CHARS) + consumedChars;
1470                    wrap(Utility.CONSUMER_CHARS, consumedChars);
1471                }
1472
1473                // are there more TypeArguments?
1474                while (signature.charAt(consumedChars) != '>') {
1475                    type.append(", ");
1476                    // check for wildcards
1477                    if (signature.charAt(consumedChars) == '+') {
1478                        type.append("? extends ");
1479                        consumedChars++;
1480                    } else if (signature.charAt(consumedChars) == '-') {
1481                        type.append("? super ");
1482                        consumedChars++;
1483                    }
1484                    if (signature.charAt(consumedChars) == '*') {
1485                        type.append("?");
1486                        consumedChars++;
1487                    } else {
1488                        type.append(typeSignatureToString(signature.substring(consumedChars), chopit));
1489                        // update our consumed count by the number of characters the for type argument
1490                        consumedChars = unwrap(Utility.CONSUMER_CHARS) + consumedChars;
1491                        wrap(Utility.CONSUMER_CHARS, consumedChars);
1492                    }
1493                }
1494
1495                // process the closing ">"
1496                consumedChars++;
1497                type.append(">");
1498
1499                if (signature.charAt(consumedChars) == '.') {
1500                    // we have a ClassTypeSignatureSuffix
1501                    type.append(".");
1502                    // convert SimpleClassTypeSignature to fake ClassTypeSignature
1503                    // and then recurse to parse it
1504                    type.append(typeSignatureToString("L" + signature.substring(consumedChars + 1), chopit));
1505                    // update our consumed count by the number of characters the for type argument
1506                    // note that this count includes the "L" we added, but that is ok
1507                    // as it accounts for the "." we didn't consume
1508                    consumedChars = unwrap(Utility.CONSUMER_CHARS) + consumedChars;
1509                    wrap(Utility.CONSUMER_CHARS, consumedChars);
1510                    return type.toString();
1511                }
1512                if (signature.charAt(consumedChars) != ';') {
1513                    throw new ClassFormatException("Invalid signature: " + signature);
1514                }
1515                wrap(Utility.CONSUMER_CHARS, consumedChars + 1); // remove final ";"
1516                return type.toString();
1517            }
1518            case 'S':
1519                return "short";
1520            case 'Z':
1521                return "boolean";
1522            case '[': { // Array declaration
1523                int n;
1524                StringBuilder brackets;
1525                String type;
1526                int consumedChars; // Shadows global var
1527                brackets = new StringBuilder(); // Accumulate []'s
1528                // Count opening brackets and look for optional size argument
1529                for (n = 0; signature.charAt(n) == '['; n++) {
1530                    brackets.append("[]");
1531                }
1532                consumedChars = n; // Remember value
1533                // The rest of the string denotes a `<field_type>'
1534                type = typeSignatureToString(signature.substring(n), chopit);
1535                // corrected concurrent private static field acess
1536                // Utility.consumed_chars += consumed_chars; is replaced by:
1537                final int temp = unwrap(Utility.CONSUMER_CHARS) + consumedChars;
1538                wrap(Utility.CONSUMER_CHARS, temp);
1539                return type + brackets.toString();
1540            }
1541            case 'V':
1542                return "void";
1543            default:
1544                throw new ClassFormatException("Invalid signature: `" + signature + "'");
1545            }
1546        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
1547            throw new ClassFormatException("Invalid signature: " + signature, e);
1548        }
1549    }
1550
1551    private static int unwrap(final ThreadLocal<Integer> tl) {
1552        return tl.get().intValue();
1553    }
1554
1555    private static void wrap(final ThreadLocal<Integer> tl, final int value) {
1556        tl.set(Integer.valueOf(value));
1557    }
1558
1559}