projects / wxWidgets.git / blame
| Commit | Line | Data |
|---|---|---|
| 38d679fd RN |
1 | /* |
| 2 | * lexical analyzer | |
| 3 | * This file is #included by regcomp.c. | |
| 4 | * | |
| 5 | * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved. | |
| 6 | * | |
| 7 | * Development of this software was funded, in part, by Cray Research Inc., | |
| 8 | * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics | |
| 9 | * Corporation, none of whom are responsible for the results. The author | |
| 10 | * thanks all of them. | |
| 11 | * | |
| 12 | * Redistribution and use in source and binary forms -- with or without | |
| 13 | * modification -- are permitted for any purpose, provided that | |
| 14 | * redistributions in source form retain this entire copyright notice and | |
| 15 | * indicate the origin and nature of any modifications. | |
| 16 | * | |
| 17 | * I'd appreciate being given credit for this package in the documentation | |
| 18 | * of software which uses it, but that is not a requirement. | |
| 19 | * | |
| 20 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, | |
| 21 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY | |
| 22 | * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL | |
| 23 | * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
| 24 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
| 25 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; | |
| 26 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, | |
| 27 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR | |
| 28 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF | |
| 29 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 30 | * | |
| 31 | * $Header$ | |
| 32 | * | |
| 33 | */ | |
| 34 | ||
| 35 | /* scanning macros (know about v) */ | |
| 36 | #define ATEOS() (v->now >= v->stop) | |
| 37 | #define HAVE(n) (v->stop - v->now >= (n)) | |
| 38 | #define NEXT1(c) (!ATEOS() && *v->now == CHR(c)) | |
| 39 | #define NEXT2(a,b) (HAVE(2) && *v->now == CHR(a) && *(v->now+1) == CHR(b)) | |
| 40 | #define NEXT3(a,b,c) (HAVE(3) && *v->now == CHR(a) && \ | |
| 41 | *(v->now+1) == CHR(b) && \ | |
| 42 | *(v->now+2) == CHR(c)) | |
| 43 | #define SET(c) (v->nexttype = (c)) | |
| 44 | #define SETV(c, n) (v->nexttype = (c), v->nextvalue = (n)) | |
| 45 | #define RET(c) return (SET(c), 1) | |
| 46 | #define RETV(c, n) return (SETV(c, n), 1) | |
| 47 | #define FAILW(e) return (ERR(e), 0) /* ERR does SET(EOS) */ | |
| 48 | #define LASTTYPE(t) (v->lasttype == (t)) | |
| 49 | ||
| 50 | /* lexical contexts */ | |
| 51 | #define L_ERE 1 /* mainline ERE/ARE */ | |
| 52 | #define L_BRE 2 /* mainline BRE */ | |
| 53 | #define L_Q 3 /* REG_QUOTE */ | |
| 54 | #define L_EBND 4 /* ERE/ARE bound */ | |
| 55 | #define L_BBND 5 /* BRE bound */ | |
| 56 | #define L_BRACK 6 /* brackets */ | |
| 57 | #define L_CEL 7 /* collating element */ | |
| 58 | #define L_ECL 8 /* equivalence class */ | |
| 59 | #define L_CCL 9 /* character class */ | |
| 60 | #define INTOCON(c) (v->lexcon = (c)) | |
| 61 | #define INCON(con) (v->lexcon == (con)) | |
| 62 | ||
| 63 | /* construct pointer past end of chr array */ | |
| 64 | #define ENDOF(array) ((array) + sizeof(array)/sizeof(chr)) | |
| 65 | ||
| 66 | /* | |
| 67 | * lexstart - set up lexical stuff, scan leading options | |
| 68 | */ | |
| 69 | static void | |
| 70 | lexstart(struct vars * v) | |
| 71 | { | |
| 72 | prefixes(v); /* may turn on new type bits etc. */ | |
| 73 | NOERR(); | |
| 74 | ||
| 75 | if (v->cflags & REG_QUOTE) | |
| 76 | { | |
| 77 | assert(!(v->cflags & (REG_ADVANCED | REG_EXPANDED | REG_NEWLINE))); | |
| 78 | INTOCON(L_Q); | |
| 79 | } | |
| 80 | else if (v->cflags & REG_EXTENDED) | |
| 81 | { | |
| 82 | assert(!(v->cflags & REG_QUOTE)); | |
| 83 | INTOCON(L_ERE); | |
| 84 | } | |
| 85 | else | |
| 86 | { | |
| 87 | assert(!(v->cflags & (REG_QUOTE | REG_ADVF))); | |
| 88 | INTOCON(L_BRE); | |
| 89 | } | |
| 90 | ||
| 91 | v->nexttype = EMPTY; /* remember we were at the start */ | |
| 92 | next(v); /* set up the first token */ | |
| 93 | } | |
| 94 | ||
| 95 | /* | |
| 96 | * prefixes - implement various special prefixes | |
| 97 | */ | |
| 98 | static void | |
| 99 | prefixes(struct vars * v) | |
| 100 | { | |
| 101 | /* literal string doesn't get any of this stuff */ | |
| 102 | if (v->cflags & REG_QUOTE) | |
| 103 | return; | |
| 104 | ||
| 105 | /* initial "***" gets special things */ | |
| 106 | if (HAVE(4) && NEXT3('*', '*', '*')) | |
| 107 | switch (*(v->now + 3)) | |
| 108 | { | |
| 109 | case CHR('?'): /* "***?" error, msg shows version */ | |
| 110 | ERR(REG_BADPAT); | |
| 111 | return; /* proceed no further */ | |
| 112 | break; | |
| 113 | case CHR('='): /* "***=" shifts to literal string */ | |
| 114 | NOTE(REG_UNONPOSIX); | |
| 115 | v->cflags |= REG_QUOTE; | |
| 116 | v->cflags &= ~(REG_ADVANCED | REG_EXPANDED | REG_NEWLINE); | |
| 117 | v->now += 4; | |
| 118 | return; /* and there can be no more prefixes */ | |
| 119 | break; | |
| 120 | case CHR(':'): /* "***:" shifts to AREs */ | |
| 121 | NOTE(REG_UNONPOSIX); | |
| 122 | v->cflags |= REG_ADVANCED; | |
| 123 | v->now += 4; | |
| 124 | break; | |
| 125 | default: /* otherwise *** is just an error */ | |
| 126 | ERR(REG_BADRPT); | |
| 127 | return; | |
| 128 | break; | |
| 129 | } | |
| 130 | ||
| 131 | /* BREs and EREs don't get embedded options */ | |
| 132 | if ((v->cflags & REG_ADVANCED) != REG_ADVANCED) | |
| 133 | return; | |
| 134 | ||
| 135 | /* embedded options (AREs only) */ | |
| 136 | if (HAVE(3) && NEXT2('(', '?') && iscalpha(*(v->now + 2))) | |
| 137 | { | |
| 138 | NOTE(REG_UNONPOSIX); | |
| 139 | v->now += 2; | |
| 140 | for (; !ATEOS() && iscalpha(*v->now); v->now++) | |
| 141 | switch (*v->now) | |
| 142 | { | |
| 143 | case CHR('b'): /* BREs (but why???) */ | |
| 144 | v->cflags &= ~(REG_ADVANCED | REG_QUOTE); | |
| 145 | break; | |
| 146 | case CHR('c'): /* case sensitive */ | |
| 147 | v->cflags &= ~REG_ICASE; | |
| 148 | break; | |
| 149 | case CHR('e'): /* plain EREs */ | |
| 150 | v->cflags |= REG_EXTENDED; | |
| 151 | v->cflags &= ~(REG_ADVF | REG_QUOTE); | |
| 152 | break; | |
| 153 | case CHR('i'): /* case insensitive */ | |
| 154 | v->cflags |= REG_ICASE; | |
| 155 | break; | |
| 156 | case CHR('m'): /* Perloid synonym for n */ | |
| 157 | case CHR('n'): /* \n affects ^ $ . [^ */ | |
| 158 | v->cflags |= REG_NEWLINE; | |
| 159 | break; | |
| 160 | case CHR('p'): /* ~Perl, \n affects . [^ */ | |
| 161 | v->cflags |= REG_NLSTOP; | |
| 162 | v->cflags &= ~REG_NLANCH; | |
| 163 | break; | |
| 164 | case CHR('q'): /* literal string */ | |
| 165 | v->cflags |= REG_QUOTE; | |
| 166 | v->cflags &= ~REG_ADVANCED; | |
| 167 | break; | |
| 168 | case CHR('s'): /* single line, \n ordinary */ | |
| 169 | v->cflags &= ~REG_NEWLINE; | |
| 170 | break; | |
| 171 | case CHR('t'): /* tight syntax */ | |
| 172 | v->cflags &= ~REG_EXPANDED; | |
| 173 | break; | |
| 174 | case CHR('w'): /* weird, \n affects ^ $ only */ | |
| 175 | v->cflags &= ~REG_NLSTOP; | |
| 176 | v->cflags |= REG_NLANCH; | |
| 177 | break; | |
| 178 | case CHR('x'): /* expanded syntax */ | |
| 179 | v->cflags |= REG_EXPANDED; | |
| 180 | break; | |
| 181 | default: | |
| 182 | ERR(REG_BADOPT); | |
| 183 | return; | |
| 184 | } | |
| 185 | if (!NEXT1(')')) | |
| 186 | { | |
| 187 | ERR(REG_BADOPT); | |
| 188 | return; | |
| 189 | } | |
| 190 | v->now++; | |
| 191 | if (v->cflags & REG_QUOTE) | |
| 192 | v->cflags &= ~(REG_EXPANDED | REG_NEWLINE); | |
| 193 | } | |
| 194 | } | |
| 195 | ||
| 196 | /* | |
| 197 | * lexnest - "call a subroutine", interpolating string at the lexical level | |
| 198 | * | |
| 199 | * Note, this is not a very general facility. There are a number of | |
| 200 | * implicit assumptions about what sorts of strings can be subroutines. | |
| 201 | */ | |
| 202 | static void | |
| 203 | lexnest(struct vars * v, | |
| 204 | chr *beginp, /* start of interpolation */ | |
| 205 | chr *endp) /* one past end of interpolation */ | |
| 206 | { | |
| 207 | assert(v->savenow == NULL); /* only one level of nesting */ | |
| 208 | v->savenow = v->now; | |
| 209 | v->savestop = v->stop; | |
| 210 | v->now = beginp; | |
| 211 | v->stop = endp; | |
| 212 | } | |
| 213 | ||
| 214 | /* | |
| 215 | * string constants to interpolate as expansions of things like \d | |
| 216 | */ | |
| 217 | static chr backd[] = { /* \d */ | |
| 218 | CHR('['), CHR('['), CHR(':'), | |
| 219 | CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'), | |
| 220 | CHR(':'), CHR(']'), CHR(']') | |
| 221 | }; | |
| 222 | static chr backD[] = { /* \D */ | |
| 223 | CHR('['), CHR('^'), CHR('['), CHR(':'), | |
| 224 | CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'), | |
| 225 | CHR(':'), CHR(']'), CHR(']') | |
| 226 | }; | |
| 227 | static chr brbackd[] = { /* \d within brackets */ | |
| 228 | CHR('['), CHR(':'), | |
| 229 | CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'), | |
| 230 | CHR(':'), CHR(']') | |
| 231 | }; | |
| 232 | static chr backs[] = { /* \s */ | |
| 233 | CHR('['), CHR('['), CHR(':'), | |
| 234 | CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'), | |
| 235 | CHR(':'), CHR(']'), CHR(']') | |
| 236 | }; | |
| 237 | static chr backS[] = { /* \S */ | |
| 238 | CHR('['), CHR('^'), CHR('['), CHR(':'), | |
| 239 | CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'), | |
| 240 | CHR(':'), CHR(']'), CHR(']') | |
| 241 | }; | |
| 242 | static chr brbacks[] = { /* \s within brackets */ | |
| 243 | CHR('['), CHR(':'), | |
| 244 | CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'), | |
| 245 | CHR(':'), CHR(']') | |
| 246 | }; | |
| 247 | static chr backw[] = { /* \w */ | |
| 248 | CHR('['), CHR('['), CHR(':'), | |
| 249 | CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'), | |
| 250 | CHR(':'), CHR(']'), CHR('_'), CHR(']') | |
| 251 | }; | |
| 252 | static chr backW[] = { /* \W */ | |
| 253 | CHR('['), CHR('^'), CHR('['), CHR(':'), | |
| 254 | CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'), | |
| 255 | CHR(':'), CHR(']'), CHR('_'), CHR(']') | |
| 256 | }; | |
| 257 | static chr brbackw[] = { /* \w within brackets */ | |
| 258 | CHR('['), CHR(':'), | |
| 259 | CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'), | |
| 260 | CHR(':'), CHR(']'), CHR('_') | |
| 261 | }; | |
| 262 | ||
| 263 | /* | |
| 264 | * lexword - interpolate a bracket expression for word characters | |
| 265 | * Possibly ought to inquire whether there is a "word" character class. | |
| 266 | */ | |
| 267 | static void | |
| 268 | lexword(struct vars * v) | |
| 269 | { | |
| 270 | lexnest(v, backw, ENDOF(backw)); | |
| 271 | } | |
| 272 | ||
| 273 | /* | |
| 274 | * next - get next token | |
| 275 | */ | |
| 276 | static int /* 1 normal, 0 failure */ | |
| 277 | next(struct vars * v) | |
| 278 | { | |
| 279 | chr c; | |
| 280 | ||
| 281 | /* errors yield an infinite sequence of failures */ | |
| 282 | if (ISERR()) | |
| 283 | return 0; /* the error has set nexttype to EOS */ | |
| 284 | ||
| 285 | /* remember flavor of last token */ | |
| 286 | v->lasttype = v->nexttype; | |
| 287 | ||
| 288 | /* REG_BOSONLY */ | |
| 289 | if (v->nexttype == EMPTY && (v->cflags & REG_BOSONLY)) | |
| 290 | { | |
| 291 | /* at start of a REG_BOSONLY RE */ | |
| 292 | RETV(SBEGIN, 0); /* same as \A */ | |
| 293 | } | |
| 294 | ||
| 295 | /* if we're nested and we've hit end, return to outer level */ | |
| 296 | if (v->savenow != NULL && ATEOS()) | |
| 297 | { | |
| 298 | v->now = v->savenow; | |
| 299 | v->stop = v->savestop; | |
| 300 | v->savenow = v->savestop = NULL; | |
| 301 | } | |
| 302 | ||
| 303 | /* skip white space etc. if appropriate (not in literal or []) */ | |
| 304 | if (v->cflags & REG_EXPANDED) | |
| 305 | switch (v->lexcon) | |
| 306 | { | |
| 307 | case L_ERE: | |
| 308 | case L_BRE: | |
| 309 | case L_EBND: | |
| 310 | case L_BBND: | |
| 311 | skip(v); | |
| 312 | break; | |
| 313 | } | |
| 314 | ||
| 315 | /* handle EOS, depending on context */ | |
| 316 | if (ATEOS()) | |
| 317 | { | |
| 318 | switch (v->lexcon) | |
| 319 | { | |
| 320 | case L_ERE: | |
| 321 | case L_BRE: | |
| 322 | case L_Q: | |
| 323 | RET(EOS); | |
| 324 | break; | |
| 325 | case L_EBND: | |
| 326 | case L_BBND: | |
| 327 | FAILW(REG_EBRACE); | |
| 328 | break; | |
| 329 | case L_BRACK: | |
| 330 | case L_CEL: | |
| 331 | case L_ECL: | |
| 332 | case L_CCL: | |
| 333 | FAILW(REG_EBRACK); | |
| 334 | break; | |
| 335 | } | |
| 336 | assert(NOTREACHED); | |
| 337 | } | |
| 338 | ||
| 339 | /* okay, time to actually get a character */ | |
| 340 | c = *v->now++; | |
| 341 | ||
| 342 | /* deal with the easy contexts, punt EREs to code below */ | |
| 343 | switch (v->lexcon) | |
| 344 | { | |
| 345 | case L_BRE: /* punt BREs to separate function */ | |
| 346 | return brenext(v, c); | |
| 347 | break; | |
| 348 | case L_ERE: /* see below */ | |
| 349 | break; | |
| 350 | case L_Q: /* literal strings are easy */ | |
| 351 | RETV(PLAIN, c); | |
| 352 | break; | |
| 353 | case L_BBND: /* bounds are fairly simple */ | |
| 354 | case L_EBND: | |
| 355 | switch (c) | |
| 356 | { | |
| 357 | case CHR('0'): | |
| 358 | case CHR('1'): | |
| 359 | case CHR('2'): | |
| 360 | case CHR('3'): | |
| 361 | case CHR('4'): | |
| 362 | case CHR('5'): | |
| 363 | case CHR('6'): | |
| 364 | case CHR('7'): | |
| 365 | case CHR('8'): | |
| 366 | case CHR('9'): | |
| 367 | RETV(DIGIT, (chr) DIGITVAL(c)); | |
| 368 | break; | |
| 369 | case CHR(','): | |
| 370 | RET(','); | |
| 371 | break; | |
| 372 | case CHR('}'): /* ERE bound ends with } */ | |
| 373 | if (INCON(L_EBND)) | |
| 374 | { | |
| 375 | INTOCON(L_ERE); | |
| 376 | if ((v->cflags & REG_ADVF) && NEXT1('?')) | |
| 377 | { | |
| 378 | v->now++; | |
| 379 | NOTE(REG_UNONPOSIX); | |
| 380 | RETV('}', 0); | |
| 381 | } | |
| 382 | RETV('}', 1); | |
| 383 | } | |
| 384 | else | |
| 385 | FAILW(REG_BADBR); | |
| 386 | break; | |
| 387 | case CHR('\\'): /* BRE bound ends with \} */ | |
| 388 | if (INCON(L_BBND) && NEXT1('}')) | |
| 389 | { | |
| 390 | v->now++; | |
| 391 | INTOCON(L_BRE); | |
| 392 | RET('}'); | |
| 393 | } | |
| 394 | else | |
| 395 | FAILW(REG_BADBR); | |
| 396 | break; | |
| 397 | default: | |
| 398 | FAILW(REG_BADBR); | |
| 399 | break; | |
| 400 | } | |
| 401 | assert(NOTREACHED); | |
| 402 | break; | |
| 403 | case L_BRACK: /* brackets are not too hard */ | |
| 404 | switch (c) | |
| 405 | { | |
| 406 | case CHR(']'): | |
| 407 | if (LASTTYPE('[')) | |
| 408 | RETV(PLAIN, c); | |
| 409 | else | |
| 410 | { | |
| 411 | INTOCON((v->cflags & REG_EXTENDED) ? | |
| 412 | L_ERE : L_BRE); | |
| 413 | RET(']'); | |
| 414 | } | |
| 415 | break; | |
| 416 | case CHR('\\'): | |
| 417 | NOTE(REG_UBBS); | |
| 418 | if (!(v->cflags & REG_ADVF)) | |
| 419 | RETV(PLAIN, c); | |
| 420 | NOTE(REG_UNONPOSIX); | |
| 421 | if (ATEOS()) | |
| 422 | FAILW(REG_EESCAPE); | |
| 423 | (DISCARD) lexescape(v); | |
| 424 | switch (v->nexttype) | |
| 425 | { /* not all escapes okay here */ | |
| 426 | case PLAIN: | |
| 427 | return 1; | |
| 428 | break; | |
| 429 | case CCLASS: | |
| 430 | switch (v->nextvalue) | |
| 431 | { | |
| 432 | case 'd': | |
| 433 | lexnest(v, brbackd, ENDOF(brbackd)); | |
| 434 | break; | |
| 435 | case 's': | |
| 436 | lexnest(v, brbacks, ENDOF(brbacks)); | |
| 437 | break; | |
| 438 | case 'w': | |
| 439 | lexnest(v, brbackw, ENDOF(brbackw)); | |
| 440 | break; | |
| 441 | default: | |
| 442 | FAILW(REG_EESCAPE); | |
| 443 | break; | |
| 444 | } | |
| 445 | /* lexnest done, back up and try again */ | |
| 446 | v->nexttype = v->lasttype; | |
| 447 | return next(v); | |
| 448 | break; | |
| 449 | } | |
| 450 | /* not one of the acceptable escapes */ | |
| 451 | FAILW(REG_EESCAPE); | |
| 452 | break; | |
| 453 | case CHR('-'): | |
| 454 | if (LASTTYPE('[') || NEXT1(']')) | |
| 455 | RETV(PLAIN, c); | |
| 456 | else | |
| 457 | RETV(RANGE, c); | |
| 458 | break; | |
| 459 | case CHR('['): | |
| 460 | if (ATEOS()) | |
| 461 | FAILW(REG_EBRACK); | |
| 462 | switch (*v->now++) | |
| 463 | { | |
| 464 | case CHR('.'): | |
| 465 | INTOCON(L_CEL); | |
| 466 | /* might or might not be locale-specific */ | |
| 467 | RET(COLLEL); | |
| 468 | break; | |
| 469 | case CHR('='): | |
| 470 | INTOCON(L_ECL); | |
| 471 | NOTE(REG_ULOCALE); | |
| 472 | RET(ECLASS); | |
| 473 | break; | |
| 474 | case CHR(':'): | |
| 475 | INTOCON(L_CCL); | |
| 476 | NOTE(REG_ULOCALE); | |
| 477 | RET(CCLASS); | |
| 478 | break; | |
| 479 | default: /* oops */ | |
| 480 | v->now--; | |
| 481 | RETV(PLAIN, c); | |
| 482 | break; | |
| 483 | } | |
| 484 | assert(NOTREACHED); | |
| 485 | break; | |
| 486 | default: | |
| 487 | RETV(PLAIN, c); | |
| 488 | break; | |
| 489 | } | |
| 490 | assert(NOTREACHED); | |
| 491 | break; | |
| 492 | case L_CEL: /* collating elements are easy */ | |
| 493 | if (c == CHR('.') && NEXT1(']')) | |
| 494 | { | |
| 495 | v->now++; | |
| 496 | INTOCON(L_BRACK); | |
| 497 | RETV(END, '.'); | |
| 498 | } | |
| 499 | else | |
| 500 | RETV(PLAIN, c); | |
| 501 | break; | |
| 502 | case L_ECL: /* ditto equivalence classes */ | |
| 503 | if (c == CHR('=') && NEXT1(']')) | |
| 504 | { | |
| 505 | v->now++; | |
| 506 | INTOCON(L_BRACK); | |
| 507 | RETV(END, '='); | |
| 508 | } | |
| 509 | else | |
| 510 | RETV(PLAIN, c); | |
| 511 | break; | |
| 512 | case L_CCL: /* ditto character classes */ | |
| 513 | if (c == CHR(':') && NEXT1(']')) | |
| 514 | { | |
| 515 | v->now++; | |
| 516 | INTOCON(L_BRACK); | |
| 517 | RETV(END, ':'); | |
| 518 | } | |
| 519 | else | |
| 520 | RETV(PLAIN, c); | |
| 521 | break; | |
| 522 | default: | |
| 523 | assert(NOTREACHED); | |
| 524 | break; | |
| 525 | } | |
| 526 | ||
| 527 | /* that got rid of everything except EREs and AREs */ | |
| 528 | assert(INCON(L_ERE)); | |
| 529 | ||
| 530 | /* deal with EREs and AREs, except for backslashes */ | |
| 531 | switch (c) | |
| 532 | { | |
| 533 | case CHR('|'): | |
| 534 | RET('|'); | |
| 535 | break; | |
| 536 | case CHR('*'): | |
| 537 | if ((v->cflags & REG_ADVF) && NEXT1('?')) | |
| 538 | { | |
| 539 | v->now++; | |
| 540 | NOTE(REG_UNONPOSIX); | |
| 541 | RETV('*', 0); | |
| 542 | } | |
| 543 | RETV('*', 1); | |
| 544 | break; | |
| 545 | case CHR('+'): | |
| 546 | if ((v->cflags & REG_ADVF) && NEXT1('?')) | |
| 547 | { | |
| 548 | v->now++; | |
| 549 | NOTE(REG_UNONPOSIX); | |
| 550 | RETV('+', 0); | |
| 551 | } | |
| 552 | RETV('+', 1); | |
| 553 | break; | |
| 554 | case CHR('?'): | |
| 555 | if ((v->cflags & REG_ADVF) && NEXT1('?')) | |
| 556 | { | |
| 557 | v->now++; | |
| 558 | NOTE(REG_UNONPOSIX); | |
| 559 | RETV('?', 0); | |
| 560 | } | |
| 561 | RETV('?', 1); | |
| 562 | break; | |
| 563 | case CHR('{'): /* bounds start or plain character */ | |
| 564 | if (v->cflags & REG_EXPANDED) | |
| 565 | skip(v); | |
| 566 | if (ATEOS() || !iscdigit(*v->now)) | |
| 567 | { | |
| 568 | NOTE(REG_UBRACES); | |
| 569 | NOTE(REG_UUNSPEC); | |
| 570 | RETV(PLAIN, c); | |
| 571 | } | |
| 572 | else | |
| 573 | { | |
| 574 | NOTE(REG_UBOUNDS); | |
| 575 | INTOCON(L_EBND); | |
| 576 | RET('{'); | |
| 577 | } | |
| 578 | assert(NOTREACHED); | |
| 579 | break; | |
| 580 | case CHR('('): /* parenthesis, or advanced extension */ | |
| 581 | if ((v->cflags & REG_ADVF) && NEXT1('?')) | |
| 582 | { | |
| 583 | NOTE(REG_UNONPOSIX); | |
| 584 | v->now++; | |
| 585 | switch (*v->now++) | |
| 586 | { | |
| 587 | case CHR(':'): /* non-capturing paren */ | |
| 588 | RETV('(', 0); | |
| 589 | break; | |
| 590 | case CHR('#'): /* comment */ | |
| 591 | while (!ATEOS() && *v->now != CHR(')')) | |
| 592 | v->now++; | |
| 593 | if (!ATEOS()) | |
| 594 | v->now++; | |
| 595 | assert(v->nexttype == v->lasttype); | |
| 596 | return next(v); | |
| 597 | break; | |
| 598 | case CHR('='): /* positive lookahead */ | |
| 599 | NOTE(REG_ULOOKAHEAD); | |
| 600 | RETV(LACON, 1); | |
| 601 | break; | |
| 602 | case CHR('!'): /* negative lookahead */ | |
| 603 | NOTE(REG_ULOOKAHEAD); | |
| 604 | RETV(LACON, 0); | |
| 605 | break; | |
| 606 | default: | |
| 607 | FAILW(REG_BADRPT); | |
| 608 | break; | |
| 609 | } | |
| 610 | assert(NOTREACHED); | |
| 611 | } | |
| 612 | if (v->cflags & REG_NOSUB) | |
| 613 | RETV('(', 0); /* all parens non-capturing */ | |
| 614 | else | |
| 615 | RETV('(', 1); | |
| 616 | break; | |
| 617 | case CHR(')'): | |
| 618 | if (LASTTYPE('(')) | |
| 619 | NOTE(REG_UUNSPEC); | |
| 620 | RETV(')', c); | |
| 621 | break; | |
| 622 | case CHR('['): /* easy except for [[:<:]] and [[:>:]] */ | |
| 623 | if (HAVE(6) && *(v->now + 0) == CHR('[') && | |
| 624 | *(v->now + 1) == CHR(':') && | |
| 625 | (*(v->now + 2) == CHR('<') || | |
| 626 | *(v->now + 2) == CHR('>')) && | |
| 627 | *(v->now + 3) == CHR(':') && | |
| 628 | *(v->now + 4) == CHR(']') && | |
| 629 | *(v->now + 5) == CHR(']')) | |
| 630 | { | |
| 631 | c = *(v->now + 2); | |
| 632 | v->now += 6; | |
| 633 | NOTE(REG_UNONPOSIX); | |
| 634 | RET((c == CHR('<')) ? '<' : '>'); | |
| 635 | } | |
| 636 | INTOCON(L_BRACK); | |
| 637 | if (NEXT1('^')) | |
| 638 | { | |
| 639 | v->now++; | |
| 640 | RETV('[', 0); | |
| 641 | } | |
| 642 | RETV('[', 1); | |
| 643 | break; | |
| 644 | case CHR('.'): | |
| 645 | RET('.'); | |
| 646 | break; | |
| 647 | case CHR('^'): | |
| 648 | RET('^'); | |
| 649 | break; | |
| 650 | case CHR('$'): | |
| 651 | RET('$'); | |
| 652 | break; | |
| 653 | case CHR('\\'): /* mostly punt backslashes to code below */ | |
| 654 | if (ATEOS()) | |
| 655 | FAILW(REG_EESCAPE); | |
| 656 | break; | |
| 657 | default: /* ordinary character */ | |
| 658 | RETV(PLAIN, c); | |
| 659 | break; | |
| 660 | } | |
| 661 | ||
| 662 | /* ERE/ARE backslash handling; backslash already eaten */ | |
| 663 | assert(!ATEOS()); | |
| 664 | if (!(v->cflags & REG_ADVF)) | |
| 665 | { /* only AREs have non-trivial escapes */ | |
| 666 | if (iscalnum(*v->now)) | |
| 667 | { | |
| 668 | NOTE(REG_UBSALNUM); | |
| 669 | NOTE(REG_UUNSPEC); | |
| 670 | } | |
| 671 | RETV(PLAIN, *v->now++); | |
| 672 | } | |
| 673 | (DISCARD) lexescape(v); | |
| 674 | if (ISERR()) | |
| 675 | FAILW(REG_EESCAPE); | |
| 676 | if (v->nexttype == CCLASS) | |
| 677 | { /* fudge at lexical level */ | |
| 678 | switch (v->nextvalue) | |
| 679 | { | |
| 680 | case 'd': | |
| 681 | lexnest(v, backd, ENDOF(backd)); | |
| 682 | break; | |
| 683 | case 'D': | |
| 684 | lexnest(v, backD, ENDOF(backD)); | |
| 685 | break; | |
| 686 | case 's': | |
| 687 | lexnest(v, backs, ENDOF(backs)); | |
| 688 | break; | |
| 689 | case 'S': | |
| 690 | lexnest(v, backS, ENDOF(backS)); | |
| 691 | break; | |
| 692 | case 'w': | |
| 693 | lexnest(v, backw, ENDOF(backw)); | |
| 694 | break; | |
| 695 | case 'W': | |
| 696 | lexnest(v, backW, ENDOF(backW)); | |
| 697 | break; | |
| 698 | default: | |
| 699 | assert(NOTREACHED); | |
| 700 | FAILW(REG_ASSERT); | |
| 701 | break; | |
| 702 | } | |
| 703 | /* lexnest done, back up and try again */ | |
| 704 | v->nexttype = v->lasttype; | |
| 705 | return next(v); | |
| 706 | } | |
| 707 | /* otherwise, lexescape has already done the work */ | |
| 708 | return !ISERR(); | |
| 709 | } | |
| 710 | ||
| 711 | /* | |
| 712 | * lexescape - parse an ARE backslash escape (backslash already eaten) | |
| 713 | * Note slightly nonstandard use of the CCLASS type code. | |
| 714 | */ | |
| 715 | static int /* not actually used, but convenient for | |
| 716 | * RETV */ | |
| 717 | lexescape(struct vars * v) | |
| 718 | { | |
| 719 | chr c; | |
| 720 | static chr alert[] = { | |
| 721 | CHR('a'), CHR('l'), CHR('e'), CHR('r'), CHR('t') | |
| 722 | }; | |
| 723 | static chr esc[] = { | |
| 724 | CHR('E'), CHR('S'), CHR('C') | |
| 725 | }; | |
| 726 | chr *save; | |
| 727 | ||
| 728 | assert(v->cflags & REG_ADVF); | |
| 729 | ||
| 730 | assert(!ATEOS()); | |
| 731 | c = *v->now++; | |
| 732 | if (!iscalnum(c)) | |
| 733 | RETV(PLAIN, c); | |
| 734 | ||
| 735 | NOTE(REG_UNONPOSIX); | |
| 736 | switch (c) | |
| 737 | { | |
| 738 | case CHR('a'): | |
| 739 | RETV(PLAIN, chrnamed(v, alert, ENDOF(alert), CHR('\007'))); | |
| 740 | break; | |
| 741 | case CHR('A'): | |
| 742 | RETV(SBEGIN, 0); | |
| 743 | break; | |
| 744 | case CHR('b'): | |
| 745 | RETV(PLAIN, CHR('\b')); | |
| 746 | break; | |
| 747 | case CHR('B'): | |
| 748 | RETV(PLAIN, CHR('\\')); | |
| 749 | break; | |
| 750 | case CHR('c'): | |
| 751 | NOTE(REG_UUNPORT); | |
| 752 | if (ATEOS()) | |
| 753 | FAILW(REG_EESCAPE); | |
| 754 | RETV(PLAIN, (chr) (*v->now++ & 037)); | |
| 755 | break; | |
| 756 | case CHR('d'): | |
| 757 | NOTE(REG_ULOCALE); | |
| 758 | RETV(CCLASS, 'd'); | |
| 759 | break; | |
| 760 | case CHR('D'): | |
| 761 | NOTE(REG_ULOCALE); | |
| 762 | RETV(CCLASS, 'D'); | |
| 763 | break; | |
| 764 | case CHR('e'): | |
| 765 | NOTE(REG_UUNPORT); | |
| 766 | RETV(PLAIN, chrnamed(v, esc, ENDOF(esc), CHR('\033'))); | |
| 767 | break; | |
| 768 | case CHR('f'): | |
| 769 | RETV(PLAIN, CHR('\f')); | |
| 770 | break; | |
| 771 | case CHR('m'): | |
| 772 | RET('<'); | |
| 773 | break; | |
| 774 | case CHR('M'): | |
| 775 | RET('>'); | |
| 776 | break; | |
| 777 | case CHR('n'): | |
| 778 | RETV(PLAIN, CHR('\n')); | |
| 779 | break; | |
| 780 | case CHR('r'): | |
| 781 | RETV(PLAIN, CHR('\r')); | |
| 782 | break; | |
| 783 | case CHR('s'): | |
| 784 | NOTE(REG_ULOCALE); | |
| 785 | RETV(CCLASS, 's'); | |
| 786 | break; | |
| 787 | case CHR('S'): | |
| 788 | NOTE(REG_ULOCALE); | |
| 789 | RETV(CCLASS, 'S'); | |
| 790 | break; | |
| 791 | case CHR('t'): | |
| 792 | RETV(PLAIN, CHR('\t')); | |
| 793 | break; | |
| 794 | case CHR('u'): | |
| 795 | c = lexdigits(v, 16, 4, 4); | |
| 796 | if (ISERR()) | |
| 797 | FAILW(REG_EESCAPE); | |
| 798 | RETV(PLAIN, c); | |
| 799 | break; | |
| 800 | case CHR('U'): | |
| 801 | c = lexdigits(v, 16, 8, 8); | |
| 802 | if (ISERR()) | |
| 803 | FAILW(REG_EESCAPE); | |
| 804 | RETV(PLAIN, c); | |
| 805 | break; | |
| 806 | case CHR('v'): | |
| 807 | RETV(PLAIN, CHR('\v')); | |
| 808 | break; | |
| 809 | case CHR('w'): | |
| 810 | NOTE(REG_ULOCALE); | |
| 811 | RETV(CCLASS, 'w'); | |
| 812 | break; | |
| 813 | case CHR('W'): | |
| 814 | NOTE(REG_ULOCALE); | |
| 815 | RETV(CCLASS, 'W'); | |
| 816 | break; | |
| 817 | case CHR('x'): | |
| 818 | NOTE(REG_UUNPORT); | |
| 819 | c = lexdigits(v, 16, 1, 255); /* REs >255 long outside | |
| 820 | * spec */ | |
| 821 | if (ISERR()) | |
| 822 | FAILW(REG_EESCAPE); | |
| 823 | RETV(PLAIN, c); | |
| 824 | break; | |
| 825 | case CHR('y'): | |
| 826 | NOTE(REG_ULOCALE); | |
| 827 | RETV(WBDRY, 0); | |
| 828 | break; | |
| 829 | case CHR('Y'): | |
| 830 | NOTE(REG_ULOCALE); | |
| 831 | RETV(NWBDRY, 0); | |
| 832 | break; | |
| 833 | case CHR('Z'): | |
| 834 | RETV(SEND, 0); | |
| 835 | break; | |
| 836 | case CHR('1'): | |
| 837 | case CHR('2'): | |
| 838 | case CHR('3'): | |
| 839 | case CHR('4'): | |
| 840 | case CHR('5'): | |
| 841 | case CHR('6'): | |
| 842 | case CHR('7'): | |
| 843 | case CHR('8'): | |
| 844 | case CHR('9'): | |
| 845 | save = v->now; | |
| 846 | v->now--; /* put first digit back */ | |
| 847 | c = lexdigits(v, 10, 1, 255); /* REs >255 long outside | |
| 848 | * spec */ | |
| 849 | if (ISERR()) | |
| 850 | FAILW(REG_EESCAPE); | |
| 851 | /* ugly heuristic (first test is "exactly 1 digit?") */ | |
| 852 | if (v->now - save == 0 || (int) c <= v->nsubexp) | |
| 853 | { | |
| 854 | NOTE(REG_UBACKREF); | |
| 855 | RETV(BACKREF, (chr) c); | |
| 856 | } | |
| 857 | /* oops, doesn't look like it's a backref after all... */ | |
| 858 | v->now = save; | |
| 859 | /* and fall through into octal number */ | |
| 860 | case CHR('0'): | |
| 861 | NOTE(REG_UUNPORT); | |
| 862 | v->now--; /* put first digit back */ | |
| 863 | c = lexdigits(v, 8, 1, 3); | |
| 864 | if (ISERR()) | |
| 865 | FAILW(REG_EESCAPE); | |
| 866 | RETV(PLAIN, c); | |
| 867 | break; | |
| 868 | default: | |
| 869 | assert(iscalpha(c)); | |
| 870 | FAILW(REG_EESCAPE); /* unknown alphabetic escape */ | |
| 871 | break; | |
| 872 | } | |
| 873 | assert(NOTREACHED); | |
| 874 | } | |
| 875 | ||
| 876 | /* | |
| 877 | * lexdigits - slurp up digits and return chr value | |
| 878 | */ | |
| 879 | static chr /* chr value; errors signalled via ERR */ | |
| 880 | lexdigits(struct vars * v, | |
| 881 | int base, | |
| 882 | int minlen, | |
| 883 | int maxlen) | |
| 884 | { | |
| 885 | uchr n; /* unsigned to avoid overflow misbehavior */ | |
| 886 | int len; | |
| 887 | chr c; | |
| 888 | int d; | |
| 889 | const uchr ub = (uchr) base; | |
| 890 | ||
| 891 | n = 0; | |
| 892 | for (len = 0; len < maxlen && !ATEOS(); len++) | |
| 893 | { | |
| 894 | c = *v->now++; | |
| 895 | switch (c) | |
| 896 | { | |
| 897 | case CHR('0'): | |
| 898 | case CHR('1'): | |
| 899 | case CHR('2'): | |
| 900 | case CHR('3'): | |
| 901 | case CHR('4'): | |
| 902 | case CHR('5'): | |
| 903 | case CHR('6'): | |
| 904 | case CHR('7'): | |
| 905 | case CHR('8'): | |
| 906 | case CHR('9'): | |
| 907 | d = DIGITVAL(c); | |
| 908 | break; | |
| 909 | case CHR('a'): | |
| 910 | case CHR('A'): | |
| 911 | d = 10; | |
| 912 | break; | |
| 913 | case CHR('b'): | |
| 914 | case CHR('B'): | |
| 915 | d = 11; | |
| 916 | break; | |
| 917 | case CHR('c'): | |
| 918 | case CHR('C'): | |
| 919 | d = 12; | |
| 920 | break; | |
| 921 | case CHR('d'): | |
| 922 | case CHR('D'): | |
| 923 | d = 13; | |
| 924 | break; | |
| 925 | case CHR('e'): | |
| 926 | case CHR('E'): | |
| 927 | d = 14; | |
| 928 | break; | |
| 929 | case CHR('f'): | |
| 930 | case CHR('F'): | |
| 931 | d = 15; | |
| 932 | break; | |
| 933 | default: | |
| 934 | v->now--; /* oops, not a digit at all */ | |
| 935 | d = -1; | |
| 936 | break; | |
| 937 | } | |
| 938 | ||
| 939 | if (d >= base) | |
| 940 | { /* not a plausible digit */ | |
| 941 | v->now--; | |
| 942 | d = -1; | |
| 943 | } | |
| 944 | if (d < 0) | |
| 945 | break; /* NOTE BREAK OUT */ | |
| 946 | n = n * ub + (uchr) d; | |
| 947 | } | |
| 948 | if (len < minlen) | |
| 949 | ERR(REG_EESCAPE); | |
| 950 | ||
| 951 | return (chr) n; | |
| 952 | } | |
| 953 | ||
| 954 | /* | |
| 955 | * brenext - get next BRE token | |
| 956 | * | |
| 957 | * This is much like EREs except for all the stupid backslashes and the | |
| 958 | * context-dependency of some things. | |
| 959 | */ | |
| 960 | static int /* 1 normal, 0 failure */ | |
| 961 | brenext(struct vars * v, | |
| 962 | chr pc) | |
| 963 | { | |
| 964 | chr c = (chr) pc; | |
| 965 | ||
| 966 | switch (c) | |
| 967 | { | |
| 968 | case CHR('*'): | |
| 969 | if (LASTTYPE(EMPTY) || LASTTYPE('(') || LASTTYPE('^')) | |
| 970 | RETV(PLAIN, c); | |
| 971 | RET('*'); | |
| 972 | break; | |
| 973 | case CHR('['): | |
| 974 | if (HAVE(6) && *(v->now + 0) == CHR('[') && | |
| 975 | *(v->now + 1) == CHR(':') && | |
| 976 | (*(v->now + 2) == CHR('<') || | |
| 977 | *(v->now + 2) == CHR('>')) && | |
| 978 | *(v->now + 3) == CHR(':') && | |
| 979 | *(v->now + 4) == CHR(']') && | |
| 980 | *(v->now + 5) == CHR(']')) | |
| 981 | { | |
| 982 | c = *(v->now + 2); | |
| 983 | v->now += 6; | |
| 984 | NOTE(REG_UNONPOSIX); | |
| 985 | RET((c == CHR('<')) ? '<' : '>'); | |
| 986 | } | |
| 987 | INTOCON(L_BRACK); | |
| 988 | if (NEXT1('^')) | |
| 989 | { | |
| 990 | v->now++; | |
| 991 | RETV('[', 0); | |
| 992 | } | |
| 993 | RETV('[', 1); | |
| 994 | break; | |
| 995 | case CHR('.'): | |
| 996 | RET('.'); | |
| 997 | break; | |
| 998 | case CHR('^'): | |
| 999 | if (LASTTYPE(EMPTY)) | |
| 1000 | RET('^'); | |
| 1001 | if (LASTTYPE('(')) | |
| 1002 | { | |
| 1003 | NOTE(REG_UUNSPEC); | |
| 1004 | RET('^'); | |
| 1005 | } | |
| 1006 | RETV(PLAIN, c); | |
| 1007 | break; | |
| 1008 | case CHR('$'): | |
| 1009 | if (v->cflags & REG_EXPANDED) | |
| 1010 | skip(v); | |
| 1011 | if (ATEOS()) | |
| 1012 | RET('$'); | |
| 1013 | if (NEXT2('\\', ')')) | |
| 1014 | { | |
| 1015 | NOTE(REG_UUNSPEC); | |
| 1016 | RET('$'); | |
| 1017 | } | |
| 1018 | RETV(PLAIN, c); | |
| 1019 | break; | |
| 1020 | case CHR('\\'): | |
| 1021 | break; /* see below */ | |
| 1022 | default: | |
| 1023 | RETV(PLAIN, c); | |
| 1024 | break; | |
| 1025 | } | |
| 1026 | ||
| 1027 | assert(c == CHR('\\')); | |
| 1028 | ||
| 1029 | if (ATEOS()) | |
| 1030 | FAILW(REG_EESCAPE); | |
| 1031 | ||
| 1032 | c = *v->now++; | |
| 1033 | switch (c) | |
| 1034 | { | |
| 1035 | case CHR('{'): | |
| 1036 | INTOCON(L_BBND); | |
| 1037 | NOTE(REG_UBOUNDS); | |
| 1038 | RET('{'); | |
| 1039 | break; | |
| 1040 | case CHR('('): | |
| 1041 | RETV('(', 1); | |
| 1042 | break; | |
| 1043 | case CHR(')'): | |
| 1044 | RETV(')', c); | |
| 1045 | break; | |
| 1046 | case CHR('<'): | |
| 1047 | NOTE(REG_UNONPOSIX); | |
| 1048 | RET('<'); | |
| 1049 | break; | |
| 1050 | case CHR('>'): | |
| 1051 | NOTE(REG_UNONPOSIX); | |
| 1052 | RET('>'); | |
| 1053 | break; | |
| 1054 | case CHR('1'): | |
| 1055 | case CHR('2'): | |
| 1056 | case CHR('3'): | |
| 1057 | case CHR('4'): | |
| 1058 | case CHR('5'): | |
| 1059 | case CHR('6'): | |
| 1060 | case CHR('7'): | |
| 1061 | case CHR('8'): | |
| 1062 | case CHR('9'): | |
| 1063 | NOTE(REG_UBACKREF); | |
| 1064 | RETV(BACKREF, (chr) DIGITVAL(c)); | |
| 1065 | break; | |
| 1066 | default: | |
| 1067 | if (iscalnum(c)) | |
| 1068 | { | |
| 1069 | NOTE(REG_UBSALNUM); | |
| 1070 | NOTE(REG_UUNSPEC); | |
| 1071 | } | |
| 1072 | RETV(PLAIN, c); | |
| 1073 | break; | |
| 1074 | } | |
| 1075 | ||
| 1076 | assert(NOTREACHED); | |
| 1077 | } | |
| 1078 | ||
| 1079 | /* | |
| 1080 | * skip - skip white space and comments in expanded form | |
| 1081 | */ | |
| 1082 | static void | |
| 1083 | skip(struct vars * v) | |
| 1084 | { | |
| 1085 | chr *start = v->now; | |
| 1086 | ||
| 1087 | assert(v->cflags & REG_EXPANDED); | |
| 1088 | ||
| 1089 | for (;;) | |
| 1090 | { | |
| 1091 | while (!ATEOS() && iscspace(*v->now)) | |
| 1092 | v->now++; | |
| 1093 | if (ATEOS() || *v->now != CHR('#')) | |
| 1094 | break; /* NOTE BREAK OUT */ | |
| 1095 | assert(NEXT1('#')); | |
| 1096 | while (!ATEOS() && *v->now != CHR('\n')) | |
| 1097 | v->now++; | |
| 1098 | /* leave the newline to be picked up by the iscspace loop */ | |
| 1099 | } | |
| 1100 | ||
| 1101 | if (v->now != start) | |
| 1102 | NOTE(REG_UNONPOSIX); | |
| 1103 | } | |
| 1104 | ||
| 1105 | /* | |
| 1106 | * newline - return the chr for a newline | |
| 1107 | * | |
| 1108 | * This helps confine use of CHR to this source file. | |
| 1109 | */ | |
| 1110 | static chr | |
| 1111 | newline(void) | |
| 1112 | { | |
| 1113 | return CHR('\n'); | |
| 1114 | } | |
| 1115 | ||
| 1116 | /* | |
| 1117 | * chrnamed - return the chr known by a given (chr string) name | |
| 1118 | * | |
| 1119 | * The code is a bit clumsy, but this routine gets only such specialized | |
| 1120 | * use that it hardly matters. | |
| 1121 | */ | |
| 1122 | static chr | |
| 1123 | chrnamed(struct vars * v, | |
| 1124 | chr *startp, /* start of name */ | |
| 1125 | chr *endp, /* just past end of name */ | |
| 1126 | chr lastresort) /* what to return if name lookup fails */ | |
| 1127 | { | |
| 1128 | celt c; | |
| 1129 | int errsave; | |
| 1130 | int e; | |
| 1131 | struct cvec *cv; | |
| 1132 | ||
| 1133 | errsave = v->err; | |
| 1134 | v->err = 0; | |
| 1135 | c = element(v, startp, endp); | |
| 1136 | e = v->err; | |
| 1137 | v->err = errsave; | |
| 1138 | ||
| 1139 | if (e != 0) | |
| 1140 | return (chr) lastresort; | |
| 1141 | ||
| 1142 | cv = range(v, c, c, 0); | |
| 1143 | if (cv->nchrs == 0) | |
| 1144 | return (chr) lastresort; | |
| 1145 | return cv->chrs[0]; | |
| 1146 | } |