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.ArrayFill;
041import org.apache.commons.lang3.ArrayUtils;
042
043/**
044 * Utility functions that do not really belong to any class in particular.
045 */
046// @since 6.0 methods are no longer final
047public abstract class Utility {
048
049    /**
050     * Decode characters into bytes. Used by <a href="Utility.html#decode(java.lang.String, boolean)">decode()</a>
051     */
052    private static final class JavaReader extends FilterReader {
053
054        public JavaReader(final Reader in) {
055            super(in);
056        }
057
058        @Override
059        public int read() throws IOException {
060            final int b = in.read();
061            if (b != ESCAPE_CHAR) {
062                return b;
063            }
064            final int i = in.read();
065            if (i < 0) {
066                return -1;
067            }
068            if (i >= '0' && i <= '9' || i >= 'a' && i <= 'f') { // Normal escape
069                final int j = in.read();
070                if (j < 0) {
071                    return -1;
072                }
073                final char[] tmp = {(char) i, (char) j};
074                return Integer.parseInt(new String(tmp), 16);
075            }
076            return MAP_CHAR[i];
077        }
078
079        @Override
080        public int read(final char[] cbuf, final int off, final int len) throws IOException {
081            for (int i = 0; i < len; i++) {
082                cbuf[off + i] = (char) read();
083            }
084            return len;
085        }
086    }
087
088    /**
089     * Encode bytes into valid Java identifier characters. Used by
090     * <a href="Utility.html#encode(byte[], boolean)">encode()</a>
091     */
092    private static final class JavaWriter extends FilterWriter {
093
094        public JavaWriter(final Writer out) {
095            super(out);
096        }
097
098        @Override
099        public void write(final char[] cbuf, final int off, final int len) throws IOException {
100            for (int i = 0; i < len; i++) {
101                write(cbuf[off + i]);
102            }
103        }
104
105        @Override
106        public void write(final int b) throws IOException {
107            if (isJavaIdentifierPart((char) b) && b != ESCAPE_CHAR) {
108                out.write(b);
109            } else {
110                out.write(ESCAPE_CHAR); // Escape character
111                // Special escape
112                if (b >= 0 && b < FREE_CHARS) {
113                    out.write(CHAR_MAP[b]);
114                } else { // Normal escape
115                    final char[] tmp = Integer.toHexString(b).toCharArray();
116                    if (tmp.length == 1) {
117                        out.write('0');
118                        out.write(tmp[0]);
119                    } else {
120                        out.write(tmp[0]);
121                        out.write(tmp[1]);
122                    }
123                }
124            }
125        }
126
127        @Override
128        public void write(final String str, final int off, final int len) throws IOException {
129            write(str.toCharArray(), off, len);
130        }
131    }
132
133    /*
134     * How many chars have been consumed during parsing in typeSignatureToString(). Read by methodSignatureToString(). Set
135     * by side effect, but only internally.
136     */
137    private static final ThreadLocal<Integer> CONSUMER_CHARS = ThreadLocal.withInitial(() -> Integer.valueOf(0));
138
139    /*
140     * The 'WIDE' instruction is used in the byte code to allow 16-bit wide indices for local variables. This opcode
141     * precedes an 'ILOAD', e.g.. The opcode immediately following takes an extra byte which is combined with the following
142     * byte to form a 16-bit value.
143     */
144    private static boolean wide;
145
146    // A-Z, g-z, _, $
147    private static final int FREE_CHARS = 48;
148
149    private static final int[] CHAR_MAP = new int[FREE_CHARS];
150
151    private static final int[] MAP_CHAR = new int[256]; // Reverse map
152
153    private static final char ESCAPE_CHAR = '$';
154
155    static {
156        int j = 0;
157        for (int i = 'A'; i <= 'Z'; i++) {
158            CHAR_MAP[j] = i;
159            MAP_CHAR[i] = j;
160            j++;
161        }
162        for (int i = 'g'; i <= 'z'; i++) {
163            CHAR_MAP[j] = i;
164            MAP_CHAR[i] = j;
165            j++;
166        }
167        CHAR_MAP[j] = '$';
168        MAP_CHAR['$'] = j;
169        j++;
170        CHAR_MAP[j] = '_';
171        MAP_CHAR['_'] = j;
172    }
173
174    /**
175     * Convert bit field of flags into string such as 'static final'.
176     *
177     * @param accessFlags Access flags
178     * @return String representation of flags
179     */
180    public static String accessToString(final int accessFlags) {
181        return accessToString(accessFlags, false);
182    }
183
184    /**
185     * Convert bit field of flags into string such as 'static final'.
186     *
187     * Special case: Classes compiled with new compilers and with the 'ACC_SUPER' flag would be said to be "synchronized".
188     * This is because SUN used the same value for the flags 'ACC_SUPER' and 'ACC_SYNCHRONIZED'.
189     *
190     * @param accessFlags Access flags
191     * @param forClass access flags are for class qualifiers ?
192     * @return String representation of flags
193     */
194    public static String accessToString(final int accessFlags, final boolean forClass) {
195        final StringBuilder buf = new StringBuilder();
196        int p = 0;
197        for (int i = 0; p < Const.MAX_ACC_FLAG_I; i++) { // Loop through known flags
198            p = pow2(i);
199            if ((accessFlags & p) != 0) {
200                /*
201                 * Special case: Classes compiled with new compilers and with the 'ACC_SUPER' flag would be said to be "synchronized".
202                 * This is because SUN used the same value for the flags 'ACC_SUPER' and 'ACC_SYNCHRONIZED'.
203                 */
204                if (forClass && (p == Const.ACC_SUPER || p == Const.ACC_INTERFACE)) {
205                    continue;
206                }
207                buf.append(Const.getAccessName(i)).append(" ");
208            }
209        }
210        return buf.toString().trim();
211    }
212
213    /**
214     * Convert (signed) byte to (unsigned) short value, i.e., all negative values become positive.
215     */
216    private static short byteToShort(final byte b) {
217        return b < 0 ? (short) (256 + b) : (short) b;
218    }
219
220    /**
221     * @param accessFlags the class flags
222     *
223     * @return "class" or "interface", depending on the ACC_INTERFACE flag
224     */
225    public static String classOrInterface(final int accessFlags) {
226        return (accessFlags & Const.ACC_INTERFACE) != 0 ? "interface" : "class";
227    }
228
229    /**
230     * @return 'flag' with bit 'i' set to 0
231     */
232    public static int clearBit(final int flag, final int i) {
233        final int bit = pow2(i);
234        return (flag & bit) == 0 ? flag : flag ^ bit;
235    }
236
237    public static String codeToString(final byte[] code, final ConstantPool constantPool, final int index, final int length) {
238        return codeToString(code, constantPool, index, length, true);
239    }
240
241    /**
242     * Disassemble a byte array of JVM byte codes starting from code line 'index' and return the disassembled string
243     * representation. Decode only 'num' opcodes (including their operands), use -1 if you want to decompile everything.
244     *
245     * @param code byte code array
246     * @param constantPool Array of constants
247     * @param index offset in 'code' array <EM>(number of opcodes, not bytes!)</EM>
248     * @param length number of opcodes to decompile, -1 for all
249     * @param verbose be verbose, e.g. print constant pool index
250     * @return String representation of byte codes
251     */
252    public static String codeToString(final byte[] code, final ConstantPool constantPool, final int index, final int length, final boolean verbose) {
253        final StringBuilder buf = new StringBuilder(code.length * 20); // Should be sufficient // CHECKSTYLE IGNORE MagicNumber
254        try (ByteSequence stream = new ByteSequence(code)) {
255            for (int i = 0; i < index; i++) {
256                codeToString(stream, constantPool, verbose);
257            }
258            for (int i = 0; stream.available() > 0; i++) {
259                if (length < 0 || i < length) {
260                    final String indices = fillup(stream.getIndex() + ":", 6, true, ' ');
261                    buf.append(indices).append(codeToString(stream, constantPool, verbose)).append('\n');
262                }
263            }
264        } catch (final IOException e) {
265            throw new ClassFormatException("Byte code error: " + buf.toString(), e);
266        }
267        return buf.toString();
268    }
269
270    public static String codeToString(final ByteSequence bytes, final ConstantPool constantPool) throws IOException {
271        return codeToString(bytes, constantPool, true);
272    }
273
274    /**
275     * Disassemble a stream of byte codes and return the string representation.
276     *
277     * @param bytes stream of bytes
278     * @param constantPool Array of constants
279     * @param verbose be verbose, e.g. print constant pool index
280     * @return String representation of byte code
281     *
282     * @throws IOException if a failure from reading from the bytes argument occurs
283     */
284    public static String codeToString(final ByteSequence bytes, final ConstantPool constantPool, final boolean verbose) throws IOException {
285        final short opcode = (short) bytes.readUnsignedByte();
286        int defaultOffset = 0;
287        int low;
288        int high;
289        int npairs;
290        int index;
291        int vindex;
292        int constant;
293        int[] match;
294        int[] jumpTable;
295        int noPadBytes = 0;
296        int offset;
297        final StringBuilder buf = new StringBuilder(Const.getOpcodeName(opcode));
298        /*
299         * Special case: Skip (0-3) padding bytes, i.e., the following bytes are 4-byte-aligned
300         */
301        if (opcode == Const.TABLESWITCH || opcode == Const.LOOKUPSWITCH) {
302            final int remainder = bytes.getIndex() % 4;
303            noPadBytes = remainder == 0 ? 0 : 4 - remainder;
304            for (int i = 0; i < noPadBytes; i++) {
305                byte b;
306                if ((b = bytes.readByte()) != 0) {
307                    System.err.println("Warning: Padding byte != 0 in " + Const.getOpcodeName(opcode) + ":" + b);
308                }
309            }
310            // Both cases have a field default_offset in common
311            defaultOffset = bytes.readInt();
312        }
313        switch (opcode) {
314        /*
315         * Table switch has variable length arguments.
316         */
317        case Const.TABLESWITCH:
318            low = bytes.readInt();
319            high = bytes.readInt();
320            offset = bytes.getIndex() - 12 - noPadBytes - 1;
321            defaultOffset += offset;
322            buf.append("\tdefault = ").append(defaultOffset).append(", low = ").append(low).append(", high = ").append(high).append("(");
323            jumpTable = new int[high - low + 1];
324            for (int i = 0; i < jumpTable.length; i++) {
325                jumpTable[i] = offset + bytes.readInt();
326                buf.append(jumpTable[i]);
327                if (i < jumpTable.length - 1) {
328                    buf.append(", ");
329                }
330            }
331            buf.append(")");
332            break;
333        /*
334         * Lookup switch has variable length arguments.
335         */
336        case Const.LOOKUPSWITCH: {
337            npairs = bytes.readInt();
338            offset = bytes.getIndex() - 8 - noPadBytes - 1;
339            match = new int[npairs];
340            jumpTable = new int[npairs];
341            defaultOffset += offset;
342            buf.append("\tdefault = ").append(defaultOffset).append(", npairs = ").append(npairs).append(" (");
343            for (int i = 0; i < npairs; i++) {
344                match[i] = bytes.readInt();
345                jumpTable[i] = offset + bytes.readInt();
346                buf.append("(").append(match[i]).append(", ").append(jumpTable[i]).append(")");
347                if (i < npairs - 1) {
348                    buf.append(", ");
349                }
350            }
351            buf.append(")");
352        }
353            break;
354        /*
355         * Two address bytes + offset from start of byte stream form the jump target
356         */
357        case Const.GOTO:
358        case Const.IFEQ:
359        case Const.IFGE:
360        case Const.IFGT:
361        case Const.IFLE:
362        case Const.IFLT:
363        case Const.JSR:
364        case Const.IFNE:
365        case Const.IFNONNULL:
366        case Const.IFNULL:
367        case Const.IF_ACMPEQ:
368        case Const.IF_ACMPNE:
369        case Const.IF_ICMPEQ:
370        case Const.IF_ICMPGE:
371        case Const.IF_ICMPGT:
372        case Const.IF_ICMPLE:
373        case Const.IF_ICMPLT:
374        case Const.IF_ICMPNE:
375            buf.append("\t\t#").append(bytes.getIndex() - 1 + bytes.readShort());
376            break;
377        /*
378         * 32-bit wide jumps
379         */
380        case Const.GOTO_W:
381        case Const.JSR_W:
382            buf.append("\t\t#").append(bytes.getIndex() - 1 + bytes.readInt());
383            break;
384        /*
385         * Index byte references local variable (register)
386         */
387        case Const.ALOAD:
388        case Const.ASTORE:
389        case Const.DLOAD:
390        case Const.DSTORE:
391        case Const.FLOAD:
392        case Const.FSTORE:
393        case Const.ILOAD:
394        case Const.ISTORE:
395        case Const.LLOAD:
396        case Const.LSTORE:
397        case Const.RET:
398            if (wide) {
399                vindex = bytes.readUnsignedShort();
400                wide = false; // Clear flag
401            } else {
402                vindex = bytes.readUnsignedByte();
403            }
404            buf.append("\t\t%").append(vindex);
405            break;
406        /*
407         * Remember wide byte which is used to form a 16-bit address in the following instruction. Relies on that the method is
408         * called again with the following opcode.
409         */
410        case Const.WIDE:
411            wide = true;
412            buf.append("\t(wide)");
413            break;
414        /*
415         * Array of basic type.
416         */
417        case Const.NEWARRAY:
418            buf.append("\t\t<").append(Const.getTypeName(bytes.readByte())).append(">");
419            break;
420        /*
421         * Access object/class fields.
422         */
423        case Const.GETFIELD:
424        case Const.GETSTATIC:
425        case Const.PUTFIELD:
426        case Const.PUTSTATIC:
427            index = bytes.readUnsignedShort();
428            buf.append("\t\t").append(constantPool.constantToString(index, Const.CONSTANT_Fieldref)).append(verbose ? " (" + index + ")" : "");
429            break;
430        /*
431         * Operands are references to classes in constant pool
432         */
433        case Const.NEW:
434        case Const.CHECKCAST:
435            buf.append("\t");
436            index = bytes.readUnsignedShort();
437            buf.append("\t<").append(constantPool.constantToString(index, Const.CONSTANT_Class)).append(">").append(verbose ? " (" + index + ")" : "");
438            break;
439        case Const.INSTANCEOF:
440            index = bytes.readUnsignedShort();
441            buf.append("\t<").append(constantPool.constantToString(index, Const.CONSTANT_Class)).append(">").append(verbose ? " (" + index + ")" : "");
442            break;
443        /*
444         * Operands are references to methods in constant pool
445         */
446        case Const.INVOKESPECIAL:
447        case Const.INVOKESTATIC:
448            index = bytes.readUnsignedShort();
449            final Constant c = constantPool.getConstant(index);
450            // With Java8 operand may be either a CONSTANT_Methodref
451            // or a CONSTANT_InterfaceMethodref. (markro)
452            buf.append("\t").append(constantPool.constantToString(index, c.getTag())).append(verbose ? " (" + index + ")" : "");
453            break;
454        case Const.INVOKEVIRTUAL:
455            index = bytes.readUnsignedShort();
456            buf.append("\t").append(constantPool.constantToString(index, Const.CONSTANT_Methodref)).append(verbose ? " (" + index + ")" : "");
457            break;
458        case Const.INVOKEINTERFACE:
459            index = bytes.readUnsignedShort();
460            final int nargs = bytes.readUnsignedByte(); // historical, redundant
461            buf.append("\t").append(constantPool.constantToString(index, Const.CONSTANT_InterfaceMethodref)).append(verbose ? " (" + index + ")\t" : "")
462                .append(nargs).append("\t").append(bytes.readUnsignedByte()); // Last byte is a reserved space
463            break;
464        case Const.INVOKEDYNAMIC:
465            index = bytes.readUnsignedShort();
466            buf.append("\t").append(constantPool.constantToString(index, Const.CONSTANT_InvokeDynamic)).append(verbose ? " (" + index + ")\t" : "")
467                .append(bytes.readUnsignedByte()) // Thrid byte is a reserved space
468                .append(bytes.readUnsignedByte()); // Last byte is a reserved space
469            break;
470        /*
471         * Operands are references to items in constant pool
472         */
473        case Const.LDC_W:
474        case Const.LDC2_W:
475            index = bytes.readUnsignedShort();
476            buf.append("\t\t").append(constantPool.constantToString(index, constantPool.getConstant(index).getTag()))
477                .append(verbose ? " (" + index + ")" : "");
478            break;
479        case Const.LDC:
480            index = bytes.readUnsignedByte();
481            buf.append("\t\t").append(constantPool.constantToString(index, constantPool.getConstant(index).getTag()))
482                .append(verbose ? " (" + index + ")" : "");
483            break;
484        /*
485         * Array of references.
486         */
487        case Const.ANEWARRAY:
488            index = bytes.readUnsignedShort();
489            buf.append("\t\t<").append(compactClassName(constantPool.getConstantString(index, Const.CONSTANT_Class), false)).append(">")
490                .append(verbose ? " (" + index + ")" : "");
491            break;
492        /*
493         * Multidimensional array of references.
494         */
495        case Const.MULTIANEWARRAY: {
496            index = bytes.readUnsignedShort();
497            final int dimensions = bytes.readUnsignedByte();
498            buf.append("\t<").append(compactClassName(constantPool.getConstantString(index, Const.CONSTANT_Class), false)).append(">\t").append(dimensions)
499                .append(verbose ? " (" + index + ")" : "");
500        }
501            break;
502        /*
503         * Increment local variable.
504         */
505        case Const.IINC:
506            if (wide) {
507                vindex = bytes.readUnsignedShort();
508                constant = bytes.readShort();
509                wide = false;
510            } else {
511                vindex = bytes.readUnsignedByte();
512                constant = bytes.readByte();
513            }
514            buf.append("\t\t%").append(vindex).append("\t").append(constant);
515            break;
516        default:
517            if (Const.getNoOfOperands(opcode) > 0) {
518                for (int i = 0; i < Const.getOperandTypeCount(opcode); i++) {
519                    buf.append("\t\t");
520                    switch (Const.getOperandType(opcode, i)) {
521                    case Const.T_BYTE:
522                        buf.append(bytes.readByte());
523                        break;
524                    case Const.T_SHORT:
525                        buf.append(bytes.readShort());
526                        break;
527                    case Const.T_INT:
528                        buf.append(bytes.readInt());
529                        break;
530                    default: // Never reached
531                        throw new IllegalStateException("Unreachable default case reached!");
532                    }
533                }
534            }
535        }
536        return buf.toString();
537    }
538
539    /**
540     * Shorten long class names, <em>java/lang/String</em> becomes <em>String</em>.
541     *
542     * @param str The long class name
543     * @return Compacted class name
544     */
545    public static String compactClassName(final String str) {
546        return compactClassName(str, true);
547    }
548
549    /**
550     * Shorten long class names, <em>java/lang/String</em> becomes <em>java.lang.String</em>, e.g.. If <em>chopit</em> is
551     * <em>true</em> the prefix <em>java.lang</em> is also removed.
552     *
553     * @param str The long class name
554     * @param chopit flag that determines whether chopping is executed or not
555     * @return Compacted class name
556     */
557    public static String compactClassName(final String str, final boolean chopit) {
558        return compactClassName(str, "java.lang.", chopit);
559    }
560
561    /**
562     * Shorten long class name <em>str</em>, i.e., chop off the <em>prefix</em>, if the class name starts with this string
563     * and the flag <em>chopit</em> is true. Slashes <em>/</em> are converted to dots <em>.</em>.
564     *
565     * @param str The long class name
566     * @param prefix The prefix the get rid off
567     * @param chopit flag that determines whether chopping is executed or not
568     * @return Compacted class name
569     */
570    public static String compactClassName(String str, final String prefix, final boolean chopit) {
571        final int len = prefix.length();
572        str = pathToPackage(str); // Is '/' on all systems, even DOS
573        // If string starts with 'prefix' and contains no further dots
574        if (chopit && str.startsWith(prefix) && str.substring(len).indexOf('.') == -1) {
575            str = str.substring(len);
576        }
577        return str;
578    }
579
580    /**
581     * Escape all occurrences of newline chars '\n', quotes \", etc.
582     */
583    public static String convertString(final String label) {
584        final char[] ch = label.toCharArray();
585        final StringBuilder buf = new StringBuilder();
586        for (final char element : ch) {
587            switch (element) {
588            case '\n':
589                buf.append("\\n");
590                break;
591            case '\r':
592                buf.append("\\r");
593                break;
594            case '\"':
595                buf.append("\\\"");
596                break;
597            case '\'':
598                buf.append("\\'");
599                break;
600            case '\\':
601                buf.append("\\\\");
602                break;
603            default:
604                buf.append(element);
605                break;
606            }
607        }
608        return buf.toString();
609    }
610
611    private static int countBrackets(final String brackets) {
612        final char[] chars = brackets.toCharArray();
613        int count = 0;
614        boolean open = false;
615        for (final char c : chars) {
616            switch (c) {
617            case '[':
618                if (open) {
619                    throw new IllegalArgumentException("Illegally nested brackets:" + brackets);
620                }
621                open = true;
622                break;
623            case ']':
624                if (!open) {
625                    throw new IllegalArgumentException("Illegally nested brackets:" + brackets);
626                }
627                open = false;
628                count++;
629                break;
630            default:
631                // Don't care
632                break;
633            }
634        }
635        if (open) {
636            throw new IllegalArgumentException("Illegally nested brackets:" + brackets);
637        }
638        return count;
639    }
640
641    /**
642     * Decode a string back to a byte array.
643     *
644     * @param s the string to convert
645     * @param uncompress use gzip to uncompress the stream of bytes
646     *
647     * @throws IOException if there's a gzip exception
648     */
649    public static byte[] decode(final String s, final boolean uncompress) throws IOException {
650        byte[] bytes;
651        try (JavaReader jr = new JavaReader(new CharArrayReader(s.toCharArray())); ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
652            int ch;
653            while ((ch = jr.read()) >= 0) {
654                bos.write(ch);
655            }
656            bytes = bos.toByteArray();
657        }
658        if (uncompress) {
659            final GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(bytes));
660            final byte[] tmp = new byte[bytes.length * 3]; // Rough estimate
661            int count = 0;
662            int b;
663            while ((b = gis.read()) >= 0) {
664                tmp[count++] = (byte) b;
665            }
666            bytes = Arrays.copyOf(tmp, count);
667        }
668        return bytes;
669    }
670
671    /**
672     * Encode byte array it into Java identifier string, i.e., a string that only contains the following characters: (a, ...
673     * z, A, ... Z, 0, ... 9, _, $). The encoding algorithm itself is not too clever: if the current byte's ASCII value
674     * already is a valid Java identifier part, leave it as it is. Otherwise it writes the escape character($) followed by:
675     *
676     * <ul>
677     * <li>the ASCII value as a hexadecimal string, if the value is not in the range 200..247</li>
678     * <li>a Java identifier char not used in a lowercase hexadecimal string, if the value is in the range 200..247</li>
679     * </ul>
680     *
681     * <p>
682     * This operation inflates the original byte array by roughly 40-50%
683     * </p>
684     *
685     * @param bytes the byte array to convert
686     * @param compress use gzip to minimize string
687     *
688     * @throws IOException if there's a gzip exception
689     */
690    public static String encode(byte[] bytes, final boolean compress) throws IOException {
691        if (compress) {
692            try (ByteArrayOutputStream baos = new ByteArrayOutputStream(); GZIPOutputStream gos = new GZIPOutputStream(baos)) {
693                gos.write(bytes, 0, bytes.length);
694                gos.close();
695                bytes = baos.toByteArray();
696            }
697        }
698        final CharArrayWriter caw = new CharArrayWriter();
699        try (JavaWriter jw = new JavaWriter(caw)) {
700            for (final byte b : bytes) {
701                final int in = b & 0x000000ff; // Normalize to unsigned
702                jw.write(in);
703            }
704        }
705        return caw.toString();
706    }
707
708    /**
709     * Fillup char with up to length characters with char 'fill' and justify it left or right.
710     *
711     * @param str string to format
712     * @param length length of desired string
713     * @param leftJustify format left or right
714     * @param fill fill character
715     * @return formatted string
716     */
717    public static String fillup(final String str, final int length, final boolean leftJustify, final char fill) {
718        final int len = length - str.length();
719        final char[] buf = ArrayFill.fill(new char[Math.max(len, 0)], fill);
720        if (leftJustify) {
721            return str + new String(buf);
722        }
723        return new String(buf) + str;
724    }
725
726    /**
727     * Return a string for an integer justified left or right and filled up with 'fill' characters if necessary.
728     *
729     * @param i integer to format
730     * @param length length of desired string
731     * @param leftJustify format left or right
732     * @param fill fill character
733     * @return formatted int
734     */
735    public static String format(final int i, final int length, final boolean leftJustify, final char fill) {
736        return fillup(Integer.toString(i), length, leftJustify, fill);
737    }
738
739    /**
740     * WARNING:
741     *
742     * There is some nomenclature confusion through much of the BCEL code base with respect to the terms Descriptor and
743     * Signature. For the offical definitions see:
744     *
745     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.3"> Descriptors in The Java
746     *      Virtual Machine Specification</a>
747     *
748     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.9.1"> Signatures in The Java
749     *      Virtual Machine Specification</a>
750     *
751     *      In brief, a descriptor is a string representing the type of a field or method. Signatures are similar, but more
752     *      complex. Signatures are used to encode declarations written in the Java programming language that use types
753     *      outside the type system of the Java Virtual Machine. They are used to describe the type of any class, interface,
754     *      constructor, method or field whose declaration uses type variables or parameterized types.
755     *
756     *      To parse a descriptor, call typeSignatureToString. To parse a signature, call signatureToString.
757     *
758     *      Note that if the signature string is a single, non-generic item, the call to signatureToString reduces to a call
759     *      to typeSignatureToString. Also note, that if you only wish to parse the first item in a longer signature string,
760     *      you should call typeSignatureToString directly.
761     */
762
763    /**
764     * Parse Java type such as "char", or "java.lang.String[]" and return the signature in byte code format, e.g. "C" or
765     * "[Ljava/lang/String;" respectively.
766     *
767     * @param type Java type
768     * @return byte code signature
769     */
770    public static String getSignature(String type) {
771        final StringBuilder buf = new StringBuilder();
772        final char[] chars = type.toCharArray();
773        boolean charFound = false;
774        boolean delim = false;
775        int index = -1;
776        loop: for (int i = 0; i < chars.length; i++) {
777            switch (chars[i]) {
778            case ' ':
779            case '\t':
780            case '\n':
781            case '\r':
782            case '\f':
783                if (charFound) {
784                    delim = true;
785                }
786                break;
787            case '[':
788                if (!charFound) {
789                    throw new IllegalArgumentException("Illegal type: " + type);
790                }
791                index = i;
792                break loop;
793            default:
794                charFound = true;
795                if (!delim) {
796                    buf.append(chars[i]);
797                }
798            }
799        }
800        int brackets = 0;
801        if (index > 0) {
802            brackets = countBrackets(type.substring(index));
803        }
804        type = buf.toString();
805        buf.setLength(0);
806        for (int i = 0; i < brackets; i++) {
807            buf.append('[');
808        }
809        boolean found = false;
810        for (int i = Const.T_BOOLEAN; i <= Const.T_VOID && !found; i++) {
811            if (Const.getTypeName(i).equals(type)) {
812                found = true;
813                buf.append(Const.getShortTypeName(i));
814            }
815        }
816        if (!found) {
817            buf.append('L').append(packageToPath(type)).append(';');
818        }
819        return buf.toString();
820    }
821
822    /**
823     * @param ch the character to test if it's part of an identifier
824     *
825     * @return true, if character is one of (a, ... z, A, ... Z, 0, ... 9, _)
826     */
827    public static boolean isJavaIdentifierPart(final char ch) {
828        return ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9' || ch == '_';
829    }
830
831    /**
832     * @return true, if bit 'i' in 'flag' is set
833     */
834    public static boolean isSet(final int flag, final int i) {
835        return (flag & pow2(i)) != 0;
836    }
837
838    /**
839     * Converts argument list portion of method signature to string with all class names compacted.
840     *
841     * @param signature Method signature
842     * @return String Array of argument types
843     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
844     */
845    public static String[] methodSignatureArgumentTypes(final String signature) throws ClassFormatException {
846        return methodSignatureArgumentTypes(signature, true);
847    }
848
849    /**
850     * Converts argument list portion of method signature to string.
851     *
852     * @param signature Method signature
853     * @param chopit flag that determines whether chopping is executed or not
854     * @return String Array of argument types
855     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
856     */
857    public static String[] methodSignatureArgumentTypes(final String signature, final boolean chopit) throws ClassFormatException {
858        final List<String> vec = new ArrayList<>();
859        int index;
860        try {
861            // Skip any type arguments to read argument declarations between '(' and ')'
862            index = signature.indexOf('(') + 1;
863            if (index <= 0) {
864                throw new InvalidMethodSignatureException(signature);
865            }
866            while (signature.charAt(index) != ')') {
867                vec.add(typeSignatureToString(signature.substring(index), chopit));
868                // corrected concurrent private static field acess
869                index += unwrap(CONSUMER_CHARS); // update position
870            }
871        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
872            throw new InvalidMethodSignatureException(signature, e);
873        }
874        return vec.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
875    }
876
877    /**
878     * Converts return type portion of method signature to string with all class names compacted.
879     *
880     * @param signature Method signature
881     * @return String representation of method return type
882     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
883     */
884    public static String methodSignatureReturnType(final String signature) throws ClassFormatException {
885        return methodSignatureReturnType(signature, true);
886    }
887
888    /**
889     * Converts return type portion of method signature to string.
890     *
891     * @param signature Method signature
892     * @param chopit flag that determines whether chopping is executed or not
893     * @return String representation of method return type
894     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
895     */
896    public static String methodSignatureReturnType(final String signature, final boolean chopit) throws ClassFormatException {
897        int index;
898        String type;
899        try {
900            // Read return type after ')'
901            index = signature.lastIndexOf(')') + 1;
902            if (index <= 0) {
903                throw new InvalidMethodSignatureException(signature);
904            }
905            type = typeSignatureToString(signature.substring(index), chopit);
906        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
907            throw new InvalidMethodSignatureException(signature, e);
908        }
909        return type;
910    }
911
912    /**
913     * Converts method signature to string with all class names compacted.
914     *
915     * @param signature to convert
916     * @param name of method
917     * @param access flags of method
918     * @return Human readable signature
919     */
920    public static String methodSignatureToString(final String signature, final String name, final String access) {
921        return methodSignatureToString(signature, name, access, true);
922    }
923
924    /**
925     * Converts method signature to string.
926     *
927     * @param signature to convert
928     * @param name of method
929     * @param access flags of method
930     * @param chopit flag that determines whether chopping is executed or not
931     * @return Human readable signature
932     */
933    public static String methodSignatureToString(final String signature, final String name, final String access, final boolean chopit) {
934        return methodSignatureToString(signature, name, access, chopit, null);
935    }
936
937    /**
938     * This method converts a method signature string into a Java type declaration like 'void main(String[])' and throws a
939     * 'ClassFormatException' when the parsed type is invalid.
940     *
941     * @param signature Method signature
942     * @param name Method name
943     * @param access Method access rights
944     * @param chopit flag that determines whether chopping is executed or not
945     * @param vars the LocalVariableTable for the method
946     * @return Java type declaration
947     * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
948     */
949    public static String methodSignatureToString(final String signature, final String name, final String access, final boolean chopit,
950        final LocalVariableTable vars) throws ClassFormatException {
951        final StringBuilder buf = new StringBuilder("(");
952        String type;
953        int index;
954        int varIndex = access.contains("static") ? 0 : 1;
955        try {
956            // Skip any type arguments to read argument declarations between '(' and ')'
957            index = signature.indexOf('(') + 1;
958            if (index <= 0) {
959                throw new InvalidMethodSignatureException(signature);
960            }
961            while (signature.charAt(index) != ')') {
962                final String paramType = typeSignatureToString(signature.substring(index), chopit);
963                buf.append(paramType);
964                if (vars != null) {
965                    final LocalVariable l = vars.getLocalVariable(varIndex, 0);
966                    if (l != null) {
967                        buf.append(" ").append(l.getName());
968                    }
969                } else {
970                    buf.append(" arg").append(varIndex);
971                }
972                if ("double".equals(paramType) || "long".equals(paramType)) {
973                    varIndex += 2;
974                } else {
975                    varIndex++;
976                }
977                buf.append(", ");
978                // corrected concurrent private static field acess
979                index += unwrap(CONSUMER_CHARS); // update position
980            }
981            index++; // update position
982            // Read return type after ')'
983            type = typeSignatureToString(signature.substring(index), chopit);
984        } catch (final StringIndexOutOfBoundsException e) { // Should never occur
985            throw new InvalidMethodSignatureException(signature, e);
986        }
987        // ignore any throws information in the signature
988        if (buf.length() > 1) {
989            buf.setLength(buf.length() - 2);
990        }
991        buf.append(")");
992        return access + (!access.isEmpty() ? " " : "") + // May be an empty string
993            type + " " + name + buf.toString();
994    }
995
996    /**
997     * Converts string containing the method return and argument types to a byte code method signature.
998     *
999     * @param ret Return type of method
1000     * @param argv Types of method arguments
1001     * @return Byte code representation of method signature
1002     *
1003     * @throws ClassFormatException if the signature is for Void
1004     */
1005    public static String methodTypeToSignature(final String ret, final String[] argv) throws ClassFormatException {
1006        final StringBuilder buf = new StringBuilder("(");
1007        String str;
1008        if (argv != null) {
1009            for (final String element : argv) {
1010                str = getSignature(element);
1011                if (str.endsWith("V")) {
1012                    throw new ClassFormatException("Invalid type: " + element);
1013                }
1014                buf.append(str);
1015            }
1016        }
1017        str = getSignature(ret);
1018        buf.append(")").append(str);
1019        return buf.toString();
1020    }
1021
1022    /**
1023     * Converts '.'s to '/'s.
1024     *
1025     * @param name Source
1026     * @return converted value
1027     * @since 6.7.0
1028     */
1029    public static String packageToPath(final String name) {
1030        return name.replace('.', '/');
1031    }
1032
1033    /**
1034     * Converts a path to a package name.
1035     *
1036     * @param str the source path.
1037     * @return a package name.
1038     * @since 6.6.0
1039     */
1040    public static String pathToPackage(final String str) {
1041        return str.replace('/', '.');
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 += 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 InvalidMethodSignatureException(signature);
1238            }
1239            index = signature.lastIndexOf(')') + 1;
1240            return typeOfSignature(signature.substring(index));
1241        } catch (final StringIndexOutOfBoundsException e) {
1242            throw new InvalidMethodSignatureException(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 InvalidMethodSignatureException(signature);
1287            }
1288        } catch (final StringIndexOutOfBoundsException e) {
1289            throw new InvalidMethodSignatureException(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(CONSUMER_CHARS) + consumedChars;
1470                    wrap(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(CONSUMER_CHARS) + consumedChars;
1491                        wrap(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(CONSUMER_CHARS) + consumedChars;
1509                    wrap(CONSUMER_CHARS, consumedChars);
1510                    return type.toString();
1511                }
1512                if (signature.charAt(consumedChars) != ';') {
1513                    throw new ClassFormatException("Invalid signature: " + signature);
1514                }
1515                wrap(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                // consumed_chars += consumed_chars; is replaced by:
1537                final int temp = unwrap(CONSUMER_CHARS) + consumedChars;
1538                wrap(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}