Mercurial > ~dholland > hg > tradcpp > index.cgi
annotate eval.c @ 107:33954a07d013
__unused -> UNUSED
author | David A. Holland |
---|---|
date | Tue, 11 Jun 2013 12:15:47 -0400 |
parents | 408331be8792 |
children | 1d2bad7151f9 |
rev | line source |
---|---|
30 | 1 /*- |
2 * Copyright (c) 2010 The NetBSD Foundation, Inc. | |
3 * All rights reserved. | |
4 * | |
5 * This code is derived from software contributed to The NetBSD Foundation | |
6 * by David A. Holland. | |
7 * | |
8 * Redistribution and use in source and binary forms, with or without | |
9 * modification, are permitted provided that the following conditions | |
10 * are met: | |
11 * 1. Redistributions of source code must retain the above copyright | |
12 * notice, this list of conditions and the following disclaimer. | |
13 * 2. Redistributions in binary form must reproduce the above copyright | |
14 * notice, this list of conditions and the following disclaimer in the | |
15 * documentation and/or other materials provided with the distribution. | |
16 * | |
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS | |
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED | |
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS | |
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
27 * POSSIBILITY OF SUCH DAMAGE. | |
28 */ | |
29 | |
16 | 30 #include <stdlib.h> |
31 #include <string.h> | |
32 #include <limits.h> | |
33 #include <errno.h> | |
34 | |
92 | 35 //#define DEBUG |
36 #ifdef DEBUG | |
37 #include <stdio.h> | |
38 #endif | |
39 | |
16 | 40 #include "utils.h" |
41 #include "array.h" | |
42 #include "mode.h" | |
43 #include "place.h" | |
44 #include "eval.h" | |
45 | |
46 /* | |
47 * e ::= | |
48 * e1 ? e2 : e3 | |
49 * e1 || e2 | |
50 * e1 && e2 | |
51 * e1 | e2 | |
52 * e1 ^ e2 | |
53 * e1 & e2 | |
54 * e1 == e2 | e1 != e2 | |
55 * e1 < e2 | e1 <= e2 | e1 > e2 | e1 >= e2 | |
56 * e1 << e2 | e1 >> e2 | |
57 * e1 + e2 | e1 - e2 | |
58 * e1 * e2 | e1 / e2 | e1 % e2 | |
59 * !e | ~e | -e | +e | |
60 * ( e ) | ident | |
61 */ | |
62 | |
63 enum tokens { | |
64 T_EOF, /* end of input */ | |
65 T_VAL, /* value */ | |
66 T_LPAREN, /* parens */ | |
67 T_RPAREN, | |
68 T_PIPEPIPE, /* operators */ | |
69 T_AMPAMP, | |
70 T_EQEQ, | |
71 T_BANGEQ, | |
72 T_LTEQ, | |
73 T_GTEQ, | |
74 T_LTLT, | |
75 T_GTGT, | |
76 T_QUES, | |
77 T_COLON, | |
78 T_PIPE, | |
79 T_CARET, | |
80 T_AMP, | |
81 T_LT, | |
82 T_GT, | |
83 T_PLUS, | |
84 T_MINUS, | |
85 T_STAR, | |
86 T_SLASH, | |
87 T_PCT, | |
88 T_BANG, | |
89 T_TILDE, | |
90 }; | |
91 | |
92 static const struct { | |
93 char c1, c2; | |
94 enum tokens tok; | |
95 } tokens_2[] = { | |
96 { '|', '|', T_PIPEPIPE }, | |
97 { '&', '&', T_AMPAMP }, | |
98 { '=', '=', T_EQEQ }, | |
99 { '!', '=', T_BANGEQ }, | |
100 { '<', '=', T_LTEQ }, | |
101 { '>', '=', T_GTEQ }, | |
102 { '<', '<', T_LTLT }, | |
103 { '>', '>', T_GTGT }, | |
104 }; | |
105 static const unsigned num_tokens_2 = HOWMANY(tokens_2); | |
106 | |
107 static const struct { | |
108 char c1; | |
109 enum tokens tok; | |
110 } tokens_1[] = { | |
111 { '?', T_QUES }, | |
112 { ':', T_COLON }, | |
113 { '|', T_PIPE }, | |
114 { '^', T_CARET }, | |
115 { '&', T_AMP }, | |
116 { '<', T_LT }, | |
117 { '>', T_GT }, | |
118 { '+', T_PLUS }, | |
119 { '-', T_MINUS }, | |
120 { '*', T_STAR }, | |
121 { '/', T_SLASH }, | |
122 { '%', T_PCT }, | |
123 { '!', T_BANG }, | |
124 { '~', T_TILDE }, | |
125 { '(', T_LPAREN }, | |
126 { ')', T_RPAREN }, | |
127 }; | |
128 static const unsigned num_tokens_1 = HOWMANY(tokens_1); | |
129 | |
130 struct token { | |
131 struct place place; | |
132 enum tokens tok; | |
133 int val; | |
134 }; | |
107 | 135 DECLARRAY(token, static UNUSED); |
47
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Fix inline usage as per the version in dholland-make2.
David A. Holland
parents:
39
diff
changeset
|
136 DEFARRAY(token, static); |
16 | 137 |
138 static struct tokenarray tokens; | |
139 | |
140 static | |
141 struct token * | |
142 token_create(const struct place *p, enum tokens tok, int val) | |
143 { | |
144 struct token *t; | |
145 | |
146 t = domalloc(sizeof(*t)); | |
147 t->place = *p; | |
148 t->tok = tok; | |
149 t->val = val; | |
150 return t; | |
151 } | |
152 | |
153 static | |
154 void | |
155 token_destroy(struct token *t) | |
156 { | |
39
337110e7240a
Pass the size to free; it makes debug checking easier.
David A. Holland
parents:
38
diff
changeset
|
157 dofree(t, sizeof(*t)); |
16 | 158 } |
159 | |
160 DESTROYALL_ARRAY(token, ); | |
161 | |
92 | 162 #ifdef DEBUG |
163 static | |
164 void | |
165 printtokens(void) | |
166 { | |
167 unsigned i, num; | |
168 struct token *t; | |
169 | |
170 fprintf(stderr, "tokens:"); | |
171 num = tokenarray_num(&tokens); | |
172 for (i=0; i<num; i++) { | |
173 t = tokenarray_get(&tokens, i); | |
174 switch (t->tok) { | |
175 case T_EOF: fprintf(stderr, " <eof>"); break; | |
176 case T_VAL: fprintf(stderr, " %d", t->val); break; | |
177 case T_LPAREN: fprintf(stderr, " ("); break; | |
178 case T_RPAREN: fprintf(stderr, " )"); break; | |
179 case T_PIPEPIPE: fprintf(stderr, " ||"); break; | |
180 case T_AMPAMP: fprintf(stderr, " &&"); break; | |
181 case T_EQEQ: fprintf(stderr, " =="); break; | |
182 case T_BANGEQ: fprintf(stderr, " !="); break; | |
183 case T_LTEQ: fprintf(stderr, " <="); break; | |
184 case T_GTEQ: fprintf(stderr, " >="); break; | |
185 case T_LTLT: fprintf(stderr, " <<"); break; | |
186 case T_GTGT: fprintf(stderr, " >>"); break; | |
187 case T_QUES: fprintf(stderr, " ?"); break; | |
188 case T_COLON: fprintf(stderr, " :"); break; | |
189 case T_PIPE: fprintf(stderr, " |"); break; | |
190 case T_CARET: fprintf(stderr, " ^"); break; | |
191 case T_AMP: fprintf(stderr, " &"); break; | |
192 case T_LT: fprintf(stderr, " <"); break; | |
193 case T_GT: fprintf(stderr, " >"); break; | |
194 case T_PLUS: fprintf(stderr, " +"); break; | |
195 case T_MINUS: fprintf(stderr, " -"); break; | |
196 case T_STAR: fprintf(stderr, " *"); break; | |
197 case T_SLASH: fprintf(stderr, " /"); break; | |
198 case T_PCT: fprintf(stderr, " %%"); break; | |
199 case T_BANG: fprintf(stderr, " !"); break; | |
200 case T_TILDE: fprintf(stderr, " ~"); break; | |
201 } | |
202 } | |
203 fprintf(stderr, "\n"); | |
204 } | |
205 #endif | |
206 | |
16 | 207 static |
208 bool | |
209 isuop(enum tokens tok) | |
210 { | |
211 switch (tok) { | |
212 case T_BANG: | |
213 case T_TILDE: | |
214 case T_MINUS: | |
215 case T_PLUS: | |
216 return true; | |
217 default: | |
218 break; | |
219 } | |
220 return false; | |
221 } | |
222 | |
223 static | |
224 bool | |
225 isbop(enum tokens tok) | |
226 { | |
227 switch (tok) { | |
228 case T_EOF: | |
229 case T_VAL: | |
230 case T_LPAREN: | |
231 case T_RPAREN: | |
232 case T_COLON: | |
233 case T_QUES: | |
234 case T_BANG: | |
235 case T_TILDE: | |
236 return false; | |
237 default: | |
238 break; | |
239 } | |
240 return true; | |
241 } | |
242 | |
243 static | |
244 bool | |
245 isop(enum tokens tok) | |
246 { | |
247 switch (tok) { | |
248 case T_EOF: | |
249 case T_VAL: | |
250 case T_LPAREN: | |
251 case T_RPAREN: | |
252 return false; | |
253 default: | |
254 break; | |
255 } | |
256 return true; | |
257 } | |
258 | |
259 static | |
260 int | |
261 getprec(enum tokens tok) | |
262 { | |
263 switch (tok) { | |
92 | 264 case T_BANG: case T_TILDE: return -1; |
16 | 265 case T_STAR: case T_SLASH: case T_PCT: return 0; |
266 case T_PLUS: case T_MINUS: return 1; | |
267 case T_LTLT: case T_GTGT: return 2; | |
268 case T_LT: case T_LTEQ: case T_GT: case T_GTEQ: return 3; | |
269 case T_EQEQ: case T_BANGEQ: return 4; | |
270 case T_AMP: return 5; | |
271 case T_CARET: return 6; | |
272 case T_PIPE: return 7; | |
273 case T_AMPAMP: return 8; | |
274 case T_PIPEPIPE: return 9; | |
275 default: break; | |
276 } | |
277 return 10; | |
278 } | |
279 | |
280 static | |
281 bool | |
282 looser(enum tokens t1, enum tokens t2) | |
283 { | |
92 | 284 return getprec(t1) >= getprec(t2); |
16 | 285 } |
286 | |
287 static | |
288 int | |
289 eval_uop(enum tokens op, int val) | |
290 { | |
291 switch (op) { | |
292 case T_BANG: val = !val; break; | |
293 case T_TILDE: val = (int)~(unsigned)val; break; | |
294 case T_MINUS: val = -val; break; | |
295 case T_PLUS: break; | |
296 default: assert(0); break; | |
297 } | |
298 return val; | |
299 } | |
300 | |
301 static | |
302 int | |
28 | 303 eval_bop(struct place *p, int lv, enum tokens op, int rv) |
16 | 304 { |
305 unsigned mask; | |
306 | |
307 switch (op) { | |
308 case T_PIPEPIPE: return lv || rv; | |
309 case T_AMPAMP: return lv && rv; | |
310 case T_PIPE: return (int)((unsigned)lv | (unsigned)rv); | |
311 case T_CARET: return (int)((unsigned)lv ^ (unsigned)rv); | |
312 case T_AMP: return (int)((unsigned)lv & (unsigned)rv); | |
313 case T_EQEQ: return lv == rv; | |
314 case T_BANGEQ: return lv != rv; | |
315 case T_LT: return lv < rv; | |
316 case T_GT: return lv > rv; | |
317 case T_LTEQ: return lv <= rv; | |
318 case T_GTEQ: return lv >= rv; | |
319 | |
320 case T_LTLT: | |
321 case T_GTGT: | |
322 if (rv < 0) { | |
323 complain(p, "Negative bit-shift"); | |
324 complain_fail(); | |
325 rv = 0; | |
326 } | |
327 if ((unsigned)rv >= CHAR_BIT * sizeof(unsigned)) { | |
328 complain(p, "Bit-shift farther than type width"); | |
329 complain_fail(); | |
330 rv = 0; | |
331 } | |
332 if (op == T_LTLT) { | |
333 return (int)((unsigned)lv << (unsigned)rv); | |
334 } | |
335 mask = ((unsigned)-1) << (CHAR_BIT * sizeof(unsigned) - rv); | |
336 lv = (int)(((unsigned)lv >> (unsigned)rv) | mask); | |
337 return lv; | |
338 | |
339 case T_MINUS: | |
340 if (rv == INT_MIN) { | |
341 if (lv == INT_MIN) { | |
342 return 0; | |
343 } | |
344 lv--; | |
345 rv++; | |
346 } | |
347 rv = -rv; | |
348 /* FALLTHROUGH */ | |
349 case T_PLUS: | |
350 if (rv > 0 && lv > (INT_MAX - rv)) { | |
351 complain(p, "Integer overflow"); | |
352 complain_fail(); | |
353 return INT_MAX; | |
354 } | |
355 if (rv < 0 && lv < (INT_MIN - rv)) { | |
356 complain(p, "Integer underflow"); | |
357 complain_fail(); | |
358 return INT_MIN; | |
359 } | |
360 return lv + rv; | |
361 | |
362 case T_STAR: | |
363 if (rv == 0) { | |
364 return 0; | |
365 } | |
366 if (rv == 1) { | |
367 return lv; | |
368 } | |
369 if (rv == -1 && lv == INT_MIN) { | |
370 lv++; | |
371 lv = -lv; | |
372 if (lv == INT_MAX) { | |
373 complain(p, "Integer overflow"); | |
374 complain_fail(); | |
375 return INT_MAX; | |
376 } | |
377 lv++; | |
378 return lv; | |
379 } | |
380 if (lv == INT_MIN && rv < 0) { | |
381 complain(p, "Integer overflow"); | |
382 complain_fail(); | |
383 return INT_MAX; | |
384 } | |
385 if (lv == INT_MIN && rv > 0) { | |
386 complain(p, "Integer underflow"); | |
387 complain_fail(); | |
388 return INT_MIN; | |
389 } | |
390 if (rv < 0) { | |
391 rv = -rv; | |
392 lv = -lv; | |
393 } | |
394 if (lv > 0 && lv > INT_MAX / rv) { | |
395 complain(p, "Integer overflow"); | |
396 complain_fail(); | |
397 return INT_MAX; | |
398 } | |
399 if (lv < 0 && lv < INT_MIN / rv) { | |
400 complain(p, "Integer underflow"); | |
401 complain_fail(); | |
402 return INT_MIN; | |
403 } | |
404 return lv * rv; | |
405 | |
406 case T_SLASH: | |
407 if (rv == 0) { | |
408 complain(p, "Division by zero"); | |
409 complain_fail(); | |
410 return 0; | |
411 } | |
412 return lv / rv; | |
413 | |
414 case T_PCT: | |
415 if (rv == 0) { | |
416 complain(p, "Modulus by zero"); | |
417 complain_fail(); | |
418 return 0; | |
419 } | |
420 return lv % rv; | |
421 | |
422 default: assert(0); break; | |
423 } | |
424 return 0; | |
425 } | |
426 | |
427 static | |
428 void | |
429 tryreduce(void) | |
430 { | |
431 unsigned num; | |
432 struct token *t1, *t2, *t3, *t4, *t5, *t6; | |
433 | |
434 while (1) { | |
92 | 435 #ifdef DEBUG |
436 printtokens(); | |
437 #endif | |
16 | 438 num = tokenarray_num(&tokens); |
439 t1 = (num >= 1) ? tokenarray_get(&tokens, num-1) : NULL; | |
440 t2 = (num >= 2) ? tokenarray_get(&tokens, num-2) : NULL; | |
441 t3 = (num >= 3) ? tokenarray_get(&tokens, num-3) : NULL; | |
442 | |
443 if (num >= 3 && | |
444 t3->tok == T_LPAREN && | |
445 t2->tok == T_VAL && | |
446 t1->tok == T_RPAREN) { | |
447 /* (x) -> x */ | |
448 t2->place = t3->place; | |
449 token_destroy(t1); | |
450 token_destroy(t3); | |
451 tokenarray_remove(&tokens, num-1); | |
452 tokenarray_remove(&tokens, num-3); | |
453 continue; | |
454 } | |
455 | |
456 if (num >= 2 && | |
457 (num == 2 || isop(t3->tok) || t3->tok == T_LPAREN) && | |
458 isuop(t2->tok) && | |
459 t1->tok == T_VAL) { | |
460 /* unary operator */ | |
461 t1->val = eval_uop(t2->tok, t1->val); | |
462 t1->place = t2->place; | |
463 token_destroy(t2); | |
464 tokenarray_remove(&tokens, num-2); | |
465 continue; | |
466 } | |
467 if (num >= 2 && | |
92 | 468 (num == 2 || isop(t3->tok) || t3->tok == T_LPAREN) && |
16 | 469 t2->tok != T_LPAREN && t2->tok != T_VAL && |
470 t1->tok == T_VAL) { | |
471 complain(&t2->place, "Invalid unary operator"); | |
472 complain_fail(); | |
473 token_destroy(t2); | |
474 tokenarray_remove(&tokens, num-2); | |
475 continue; | |
476 } | |
477 | |
478 | |
479 t4 = (num >= 4) ? tokenarray_get(&tokens, num-4) : NULL; | |
480 | |
481 if (num >= 4 && | |
482 t4->tok == T_VAL && | |
483 isbop(t3->tok) && | |
92 | 484 t2->tok == T_VAL) { |
16 | 485 /* binary operator */ |
486 if (looser(t1->tok, t3->tok)) { | |
487 t4->val = eval_bop(&t3->place, | |
488 t4->val, t3->tok, t2->val); | |
489 token_destroy(t2); | |
490 token_destroy(t3); | |
491 tokenarray_remove(&tokens, num-2); | |
492 tokenarray_remove(&tokens, num-3); | |
493 continue; | |
494 } | |
495 break; | |
496 } | |
497 | |
498 t5 = (num >= 5) ? tokenarray_get(&tokens, num-5) : NULL; | |
499 t6 = (num >= 6) ? tokenarray_get(&tokens, num-6) : NULL; | |
500 | |
91
bd1b7a09da89
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parents:
63
diff
changeset
|
501 if (num >= 6 && |
16 | 502 t6->tok == T_VAL && |
503 t5->tok == T_QUES && | |
504 t4->tok == T_VAL && | |
505 t3->tok == T_COLON && | |
506 t2->tok == T_VAL && | |
507 !isop(t1->tok)) { | |
508 /* conditional expression */ | |
509 t6->val = t6->val ? t4->val : t2->val; | |
510 token_destroy(t2); | |
511 token_destroy(t3); | |
512 token_destroy(t4); | |
513 token_destroy(t5); | |
514 tokenarray_remove(&tokens, num-2); | |
515 tokenarray_remove(&tokens, num-3); | |
516 tokenarray_remove(&tokens, num-4); | |
517 tokenarray_remove(&tokens, num-5); | |
518 continue; | |
519 } | |
520 | |
521 if (num >= 2 && | |
522 t2->tok == T_LPAREN && | |
523 t1->tok == T_RPAREN) { | |
524 complain(&t1->place, "Value expected within ()"); | |
525 complain_fail(); | |
526 t1->tok = T_VAL; | |
527 t1->val = 0; | |
528 token_destroy(t1); | |
529 tokenarray_remove(&tokens, num-1); | |
530 continue; | |
531 } | |
532 | |
533 if (num >= 2 && | |
534 t2->tok == T_VAL && | |
535 t1->tok == T_VAL) { | |
536 complain(&t1->place, "Operator expected"); | |
537 complain_fail(); | |
538 token_destroy(t1); | |
539 tokenarray_remove(&tokens, num-1); | |
540 continue; | |
541 } | |
542 | |
543 if (num >= 2 && | |
544 isop(t2->tok) && | |
545 t1->tok == T_EOF) { | |
546 complain(&t1->place, "Value expected after operator"); | |
547 complain_fail(); | |
548 token_destroy(t2); | |
549 tokenarray_remove(&tokens, num-2); | |
550 continue; | |
551 } | |
552 | |
553 if (num == 2 && | |
554 t2->tok == T_VAL && | |
555 t1->tok == T_RPAREN) { | |
556 complain(&t1->place, "Excess right parenthesis"); | |
557 complain_fail(); | |
558 token_destroy(t1); | |
559 tokenarray_remove(&tokens, num-1); | |
560 continue; | |
561 } | |
562 | |
563 if (num == 3 && | |
564 t3->tok == T_LPAREN && | |
565 t2->tok == T_VAL && | |
566 t1->tok == T_EOF) { | |
567 complain(&t1->place, "Unclosed left parenthesis"); | |
568 complain_fail(); | |
569 token_destroy(t3); | |
570 tokenarray_remove(&tokens, num-3); | |
571 continue; | |
572 } | |
573 | |
574 if (num == 2 && | |
575 t2->tok == T_VAL && | |
576 t1->tok == T_EOF) { | |
577 /* accepting state */ | |
578 break; | |
579 } | |
580 | |
581 if (num >= 1 && | |
582 t1->tok == T_EOF) { | |
583 /* any other configuration at eof is an error */ | |
584 complain(&t1->place, "Parse error"); | |
585 complain_fail(); | |
586 break; | |
587 } | |
588 | |
589 /* otherwise, wait for more input */ | |
590 break; | |
591 } | |
592 } | |
593 | |
594 static | |
595 void | |
596 token(struct place *p, enum tokens tok, int val) | |
597 { | |
598 struct token *t; | |
599 | |
600 t = token_create(p, tok, val); | |
601 | |
602 tokenarray_add(&tokens, t, NULL); | |
603 tryreduce(); | |
604 } | |
605 | |
606 static | |
607 int | |
608 wordval(struct place *p, char *word) | |
609 { | |
610 unsigned long val; | |
611 char *t; | |
612 | |
613 if (word[0] >= '0' && word[0] <= '9') { | |
614 errno = 0; | |
615 val = strtoul(word, &t, 0); | |
96 | 616 if (errno) { |
16 | 617 complain(p, "Invalid integer constant"); |
618 complain_fail(); | |
619 return 0; | |
620 } | |
96 | 621 while (*t == 'U' || *t == 'L') { |
622 t++; | |
623 } | |
624 if (*t != '\0') { | |
625 complain(p, "Trailing garbage after integer constant"); | |
626 complain_fail(); | |
627 return 0; | |
628 } | |
16 | 629 if (val > INT_MAX) { |
630 complain(p, "Integer constant too large"); | |
631 complain_fail(); | |
632 return INT_MAX; | |
633 } | |
634 return val; | |
635 } | |
636 | |
637 /* if it's a symbol, warn and substitute 0. */ | |
638 if (warns.undef) { | |
639 complain(p, "Warning: value of undefined symbol %s is 0", | |
640 word); | |
641 if (mode.werror) { | |
642 complain_fail(); | |
643 } | |
644 } | |
645 return 0; | |
646 } | |
647 | |
648 static | |
649 bool | |
650 check_word(struct place *p, char *expr, size_t pos, size_t *len_ret) | |
651 { | |
652 size_t len; | |
653 int val; | |
654 char tmp; | |
655 | |
656 if (!strchr(alnum, expr[pos])) { | |
657 return false; | |
658 } | |
659 len = strspn(expr + pos, alnum); | |
660 tmp = expr[pos + len]; | |
661 expr[pos + len] = '\0'; | |
662 val = wordval(p, expr + pos); | |
663 expr[pos + len] = tmp; | |
664 token(p, T_VAL, val); | |
665 *len_ret = len; | |
666 return true; | |
667 } | |
668 | |
669 static | |
670 bool | |
671 check_tokens_2(struct place *p, char *expr, size_t pos) | |
672 { | |
673 unsigned i; | |
674 | |
675 for (i=0; i<num_tokens_2; i++) { | |
676 if (expr[pos] == tokens_2[i].c1 && | |
677 expr[pos+1] == tokens_2[i].c2) { | |
678 token(p, tokens_2[i].tok, 0); | |
679 return true; | |
680 } | |
681 } | |
682 return false; | |
683 } | |
684 | |
685 static | |
686 bool | |
687 check_tokens_1(struct place *p, char *expr, size_t pos) | |
688 { | |
689 unsigned i; | |
690 | |
691 for (i=0; i<num_tokens_1; i++) { | |
692 if (expr[pos] == tokens_1[i].c1) { | |
693 token(p, tokens_1[i].tok, 0); | |
694 return true; | |
695 } | |
696 } | |
697 return false; | |
698 } | |
699 | |
700 static | |
701 void | |
702 tokenize(struct place *p, char *expr) | |
703 { | |
704 size_t pos, len; | |
705 | |
706 pos = 0; | |
707 while (expr[pos] != '\0') { | |
708 len = strspn(expr+pos, ws); | |
709 pos += len; | |
710 p->column += len; | |
63 | 711 /* trailing whitespace is supposed to have been pruned */ |
712 assert(expr[pos] != '\0'); | |
16 | 713 if (check_word(p, expr, pos, &len)) { |
714 pos += len; | |
715 p->column += len; | |
716 continue; | |
717 } | |
718 if (check_tokens_2(p, expr, pos)) { | |
719 pos += 2; | |
720 p->column += 2; | |
721 continue; | |
722 } | |
723 if (check_tokens_1(p, expr, pos)) { | |
724 pos++; | |
725 p->column++; | |
726 continue; | |
727 } | |
728 complain(p, "Invalid character %u in #if-expression", | |
729 (unsigned char)expr[pos]); | |
730 complain_fail(); | |
731 pos++; | |
732 p->column++; | |
733 } | |
734 token(p, T_EOF, 0); | |
735 } | |
736 | |
737 bool | |
738 eval(struct place *p, char *expr) | |
739 { | |
740 struct token *t1, *t2; | |
741 unsigned num; | |
742 bool result; | |
743 | |
92 | 744 #ifdef DEBUG |
745 fprintf(stderr, "eval: %s\n", expr); | |
746 #endif | |
747 | |
16 | 748 tokenarray_init(&tokens); |
749 tokenize(p, expr); | |
750 | |
751 result = false; | |
752 num = tokenarray_num(&tokens); | |
753 if (num == 2) { | |
754 t1 = tokenarray_get(&tokens, num-1); | |
755 t2 = tokenarray_get(&tokens, num-2); | |
91
bd1b7a09da89
Don't expect the eval result to contain EOF *then* a value.
David A. Holland
parents:
63
diff
changeset
|
756 if (t2->tok == T_VAL && |
bd1b7a09da89
Don't expect the eval result to contain EOF *then* a value.
David A. Holland
parents:
63
diff
changeset
|
757 t1->tok == T_EOF) { |
bd1b7a09da89
Don't expect the eval result to contain EOF *then* a value.
David A. Holland
parents:
63
diff
changeset
|
758 result = t2->val != 0; |
16 | 759 } |
760 } | |
761 | |
762 tokenarray_destroyall(&tokens); | |
763 tokenarray_cleanup(&tokens); | |
764 return result; | |
765 } |