| 1 | /* |
| 2 | * Copyright 2004-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.tools.javac.parser; |
| 27 | |
| 28 | import java.io.*; |
| 29 | import java.nio.*; |
| 30 | |
| 31 | import com.sun.tools.javac.util.*; |
| 32 | import static com.sun.tools.javac.util.LayoutCharacters.*; |
| 33 | |
| 34 | /** An extension to the base lexical analyzer that captures |
| 35 | * and processes the contents of doc comments. It does so by |
| 36 | * translating Unicode escape sequences and by stripping the |
| 37 | * leading whitespace and starts from each line of the comment. |
| 38 | * |
| 39 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
| 40 | * you write code that depends on this, you do so at your own risk. |
| 41 | * This code and its internal interfaces are subject to change or |
| 42 | * deletion without notice.</b> |
| 43 | */ |
| 44 | public class DocCommentScanner extends Scanner { |
| 45 | |
| 46 | /** A factory for creating scanners. */ |
| 47 | public static class Factory extends Scanner.Factory { |
| 48 | |
| 49 | public static void preRegister(final Context context) { |
| 50 | context.put(scannerFactoryKey, new Context.Factory<Scanner.Factory>() { |
| 51 | public Factory make() { |
| 52 | return new Factory(context); |
| 53 | } |
| 54 | }); |
| 55 | } |
| 56 | |
| 57 | /** Create a new scanner factory. */ |
| 58 | protected Factory(Context context) { |
| 59 | super(context); |
| 60 | } |
| 61 | |
| 62 | @Override |
| 63 | public Scanner newScanner(CharSequence input) { |
| 64 | if (input instanceof CharBuffer) { |
| 65 | return new DocCommentScanner(this, (CharBuffer)input); |
| 66 | } else { |
| 67 | char[] array = input.toString().toCharArray(); |
| 68 | return newScanner(array, array.length); |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | @Override |
| 73 | public Scanner newScanner(char[] input, int inputLength) { |
| 74 | return new DocCommentScanner(this, input, inputLength); |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | |
| 79 | /** Create a scanner from the input buffer. buffer must implement |
| 80 | * array() and compact(), and remaining() must be less than limit(). |
| 81 | */ |
| 82 | protected DocCommentScanner(Factory fac, CharBuffer buffer) { |
| 83 | super(fac, buffer); |
| 84 | } |
| 85 | |
| 86 | /** Create a scanner from the input array. The array must have at |
| 87 | * least a single character of extra space. |
| 88 | */ |
| 89 | protected DocCommentScanner(Factory fac, char[] input, int inputLength) { |
| 90 | super(fac, input, inputLength); |
| 91 | } |
| 92 | |
| 93 | /** Starting position of the comment in original source |
| 94 | */ |
| 95 | private int pos; |
| 96 | |
| 97 | /** The comment input buffer, index of next chacter to be read, |
| 98 | * index of one past last character in buffer. |
| 99 | */ |
| 100 | private char[] buf; |
| 101 | private int bp; |
| 102 | private int buflen; |
| 103 | |
| 104 | /** The current character. |
| 105 | */ |
| 106 | private char ch; |
| 107 | |
| 108 | /** The column number position of the current character. |
| 109 | */ |
| 110 | private int col; |
| 111 | |
| 112 | /** The buffer index of the last converted Unicode character |
| 113 | */ |
| 114 | private int unicodeConversionBp = 0; |
| 115 | |
| 116 | /** |
| 117 | * Buffer for doc comment. |
| 118 | */ |
| 119 | private char[] docCommentBuffer = new char[1024]; |
| 120 | |
| 121 | /** |
| 122 | * Number of characters in doc comment buffer. |
| 123 | */ |
| 124 | private int docCommentCount; |
| 125 | |
| 126 | /** |
| 127 | * Translated and stripped contents of doc comment |
| 128 | */ |
| 129 | private String docComment = null; |
| 130 | |
| 131 | |
| 132 | /** Unconditionally expand the comment buffer. |
| 133 | */ |
| 134 | private void expandCommentBuffer() { |
| 135 | char[] newBuffer = new char[docCommentBuffer.length * 2]; |
| 136 | System.arraycopy(docCommentBuffer, 0, newBuffer, |
| 137 | 0, docCommentBuffer.length); |
| 138 | docCommentBuffer = newBuffer; |
| 139 | } |
| 140 | |
| 141 | /** Convert an ASCII digit from its base (8, 10, or 16) |
| 142 | * to its value. |
| 143 | */ |
| 144 | private int digit(int base) { |
| 145 | char c = ch; |
| 146 | int result = Character.digit(c, base); |
| 147 | if (result >= 0 && c > 0x7f) { |
| 148 | ch = "0123456789abcdef".charAt(result); |
| 149 | } |
| 150 | return result; |
| 151 | } |
| 152 | |
| 153 | /** Convert Unicode escape; bp points to initial '\' character |
| 154 | * (Spec 3.3). |
| 155 | */ |
| 156 | private void convertUnicode() { |
| 157 | if (ch == '\\' && unicodeConversionBp != bp) { |
| 158 | bp++; ch = buf[bp]; col++; |
| 159 | if (ch == 'u') { |
| 160 | do { |
| 161 | bp++; ch = buf[bp]; col++; |
| 162 | } while (ch == 'u'); |
| 163 | int limit = bp + 3; |
| 164 | if (limit < buflen) { |
| 165 | int d = digit(16); |
| 166 | int code = d; |
| 167 | while (bp < limit && d >= 0) { |
| 168 | bp++; ch = buf[bp]; col++; |
| 169 | d = digit(16); |
| 170 | code = (code << 4) + d; |
| 171 | } |
| 172 | if (d >= 0) { |
| 173 | ch = (char)code; |
| 174 | unicodeConversionBp = bp; |
| 175 | return; |
| 176 | } |
| 177 | } |
| 178 | // "illegal.Unicode.esc", reported by base scanner |
| 179 | } else { |
| 180 | bp--; |
| 181 | ch = '\\'; |
| 182 | col--; |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | |
| 188 | /** Read next character. |
| 189 | */ |
| 190 | private void scanChar() { |
| 191 | bp++; |
| 192 | ch = buf[bp]; |
| 193 | switch (ch) { |
| 194 | case '\r': // return |
| 195 | col = 0; |
| 196 | break; |
| 197 | case '\n': // newline |
| 198 | if (bp == 0 || buf[bp-1] != '\r') { |
| 199 | col = 0; |
| 200 | } |
| 201 | break; |
| 202 | case '\t': // tab |
| 203 | col = (col / TabInc * TabInc) + TabInc; |
| 204 | break; |
| 205 | case '\\': // possible Unicode |
| 206 | col++; |
| 207 | convertUnicode(); |
| 208 | break; |
| 209 | default: |
| 210 | col++; |
| 211 | break; |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * Read next character in doc comment, skipping over double '\' characters. |
| 217 | * If a double '\' is skipped, put in the buffer and update buffer count. |
| 218 | */ |
| 219 | private void scanDocCommentChar() { |
| 220 | scanChar(); |
| 221 | if (ch == '\\') { |
| 222 | if (buf[bp+1] == '\\' && unicodeConversionBp != bp) { |
| 223 | if (docCommentCount == docCommentBuffer.length) |
| 224 | expandCommentBuffer(); |
| 225 | docCommentBuffer[docCommentCount++] = ch; |
| 226 | bp++; col++; |
| 227 | } else { |
| 228 | convertUnicode(); |
| 229 | } |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | /* Reset doc comment before reading each new token |
| 234 | */ |
| 235 | public void nextToken() { |
| 236 | docComment = null; |
| 237 | super.nextToken(); |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * Returns the documentation string of the current token. |
| 242 | */ |
| 243 | public String docComment() { |
| 244 | return docComment; |
| 245 | } |
| 246 | |
| 247 | /** |
| 248 | * Process a doc comment and make the string content available. |
| 249 | * Strips leading whitespace and stars. |
| 250 | */ |
| 251 | @SuppressWarnings("fallthrough") |
| 252 | protected void processComment(CommentStyle style) { |
| 253 | if (style != CommentStyle.JAVADOC) { |
| 254 | return; |
| 255 | } |
| 256 | |
| 257 | pos = pos(); |
| 258 | buf = getRawCharacters(pos, endPos()); |
| 259 | buflen = buf.length; |
| 260 | bp = 0; |
| 261 | col = 0; |
| 262 | |
| 263 | docCommentCount = 0; |
| 264 | |
| 265 | boolean firstLine = true; |
| 266 | |
| 267 | // Skip over first slash |
| 268 | scanDocCommentChar(); |
| 269 | // Skip over first star |
| 270 | scanDocCommentChar(); |
| 271 | |
| 272 | // consume any number of stars |
| 273 | while (bp < buflen && ch == '*') { |
| 274 | scanDocCommentChar(); |
| 275 | } |
| 276 | // is the comment in the form /**/, /***/, /****/, etc. ? |
| 277 | if (bp < buflen && ch == '/') { |
| 278 | docComment = ""; |
| 279 | return; |
| 280 | } |
| 281 | |
| 282 | // skip a newline on the first line of the comment. |
| 283 | if (bp < buflen) { |
| 284 | if (ch == LF) { |
| 285 | scanDocCommentChar(); |
| 286 | firstLine = false; |
| 287 | } else if (ch == CR) { |
| 288 | scanDocCommentChar(); |
| 289 | if (ch == LF) { |
| 290 | scanDocCommentChar(); |
| 291 | firstLine = false; |
| 292 | } |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | outerLoop: |
| 297 | |
| 298 | // The outerLoop processes the doc comment, looping once |
| 299 | // for each line. For each line, it first strips off |
| 300 | // whitespace, then it consumes any stars, then it |
| 301 | // puts the rest of the line into our buffer. |
| 302 | while (bp < buflen) { |
| 303 | |
| 304 | // The wsLoop consumes whitespace from the beginning |
| 305 | // of each line. |
| 306 | wsLoop: |
| 307 | |
| 308 | while (bp < buflen) { |
| 309 | switch(ch) { |
| 310 | case ' ': |
| 311 | scanDocCommentChar(); |
| 312 | break; |
| 313 | case '\t': |
| 314 | col = ((col - 1) / TabInc * TabInc) + TabInc; |
| 315 | scanDocCommentChar(); |
| 316 | break; |
| 317 | case FF: |
| 318 | col = 0; |
| 319 | scanDocCommentChar(); |
| 320 | break; |
| 321 | // Treat newline at beginning of line (blank line, no star) |
| 322 | // as comment text. Old Javadoc compatibility requires this. |
| 323 | /*---------------------------------* |
| 324 | case CR: // (Spec 3.4) |
| 325 | scanDocCommentChar(); |
| 326 | if (ch == LF) { |
| 327 | col = 0; |
| 328 | scanDocCommentChar(); |
| 329 | } |
| 330 | break; |
| 331 | case LF: // (Spec 3.4) |
| 332 | scanDocCommentChar(); |
| 333 | break; |
| 334 | *---------------------------------*/ |
| 335 | default: |
| 336 | // we've seen something that isn't whitespace; |
| 337 | // jump out. |
| 338 | break wsLoop; |
| 339 | } |
| 340 | } |
| 341 | |
| 342 | // Are there stars here? If so, consume them all |
| 343 | // and check for the end of comment. |
| 344 | if (ch == '*') { |
| 345 | // skip all of the stars |
| 346 | do { |
| 347 | scanDocCommentChar(); |
| 348 | } while (ch == '*'); |
| 349 | |
| 350 | // check for the closing slash. |
| 351 | if (ch == '/') { |
| 352 | // We're done with the doc comment |
| 353 | // scanChar() and breakout. |
| 354 | break outerLoop; |
| 355 | } |
| 356 | } else if (! firstLine) { |
| 357 | //The current line does not begin with a '*' so we will indent it. |
| 358 | for (int i = 1; i < col; i++) { |
| 359 | if (docCommentCount == docCommentBuffer.length) |
| 360 | expandCommentBuffer(); |
| 361 | docCommentBuffer[docCommentCount++] = ' '; |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | // The textLoop processes the rest of the characters |
| 366 | // on the line, adding them to our buffer. |
| 367 | textLoop: |
| 368 | while (bp < buflen) { |
| 369 | switch (ch) { |
| 370 | case '*': |
| 371 | // Is this just a star? Or is this the |
| 372 | // end of a comment? |
| 373 | scanDocCommentChar(); |
| 374 | if (ch == '/') { |
| 375 | // This is the end of the comment, |
| 376 | // set ch and return our buffer. |
| 377 | break outerLoop; |
| 378 | } |
| 379 | // This is just an ordinary star. Add it to |
| 380 | // the buffer. |
| 381 | if (docCommentCount == docCommentBuffer.length) |
| 382 | expandCommentBuffer(); |
| 383 | docCommentBuffer[docCommentCount++] = '*'; |
| 384 | break; |
| 385 | case ' ': |
| 386 | case '\t': |
| 387 | if (docCommentCount == docCommentBuffer.length) |
| 388 | expandCommentBuffer(); |
| 389 | docCommentBuffer[docCommentCount++] = ch; |
| 390 | scanDocCommentChar(); |
| 391 | break; |
| 392 | case FF: |
| 393 | scanDocCommentChar(); |
| 394 | break textLoop; // treat as end of line |
| 395 | case CR: // (Spec 3.4) |
| 396 | scanDocCommentChar(); |
| 397 | if (ch != LF) { |
| 398 | // Canonicalize CR-only line terminator to LF |
| 399 | if (docCommentCount == docCommentBuffer.length) |
| 400 | expandCommentBuffer(); |
| 401 | docCommentBuffer[docCommentCount++] = (char)LF; |
| 402 | break textLoop; |
| 403 | } |
| 404 | /* fall through to LF case */ |
| 405 | case LF: // (Spec 3.4) |
| 406 | // We've seen a newline. Add it to our |
| 407 | // buffer and break out of this loop, |
| 408 | // starting fresh on a new line. |
| 409 | if (docCommentCount == docCommentBuffer.length) |
| 410 | expandCommentBuffer(); |
| 411 | docCommentBuffer[docCommentCount++] = ch; |
| 412 | scanDocCommentChar(); |
| 413 | break textLoop; |
| 414 | default: |
| 415 | // Add the character to our buffer. |
| 416 | if (docCommentCount == docCommentBuffer.length) |
| 417 | expandCommentBuffer(); |
| 418 | docCommentBuffer[docCommentCount++] = ch; |
| 419 | scanDocCommentChar(); |
| 420 | } |
| 421 | } // end textLoop |
| 422 | firstLine = false; |
| 423 | } // end outerLoop |
| 424 | |
| 425 | if (docCommentCount > 0) { |
| 426 | int i = docCommentCount - 1; |
| 427 | trailLoop: |
| 428 | while (i > -1) { |
| 429 | switch (docCommentBuffer[i]) { |
| 430 | case '*': |
| 431 | i--; |
| 432 | break; |
| 433 | default: |
| 434 | break trailLoop; |
| 435 | } |
| 436 | } |
| 437 | docCommentCount = i + 1; |
| 438 | |
| 439 | // Store the text of the doc comment |
| 440 | docComment = new String(docCommentBuffer, 0 , docCommentCount); |
| 441 | } else { |
| 442 | docComment = ""; |
| 443 | } |
| 444 | } |
| 445 | |
| 446 | /** Build a map for translating between line numbers and |
| 447 | * positions in the input. |
| 448 | * |
| 449 | * @return a LineMap */ |
| 450 | public Position.LineMap getLineMap() { |
| 451 | char[] buf = getRawCharacters(); |
| 452 | return Position.makeLineMap(buf, buf.length, true); |
| 453 | } |
| 454 | } |