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1/*
2 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
3 * Released under the terms of the GNU GPL v2.0.
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <string.h>
9
10#include "lkc.h"
11
12#define DEBUG_EXPR 0
13
14struct expr *expr_alloc_symbol(struct symbol *sym)
15{
16 struct expr *e = calloc(1, sizeof(*e));
17 e->type = E_SYMBOL;
18 e->left.sym = sym;
19 return e;
20}
21
22struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
23{
24 struct expr *e = calloc(1, sizeof(*e));
25 e->type = type;
26 e->left.expr = ce;
27 return e;
28}
29
30struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
31{
32 struct expr *e = calloc(1, sizeof(*e));
33 e->type = type;
34 e->left.expr = e1;
35 e->right.expr = e2;
36 return e;
37}
38
39struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
40{
41 struct expr *e = calloc(1, sizeof(*e));
42 e->type = type;
43 e->left.sym = s1;
44 e->right.sym = s2;
45 return e;
46}
47
48struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
49{
50 if (!e1)
51 return e2;
52 return e2 ? expr_alloc_two(E_AND, e1, e2) : e1;
53}
54
55struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
56{
57 if (!e1)
58 return e2;
59 return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
60}
61
62struct expr *expr_copy(const struct expr *org)
63{
64 struct expr *e;
65
66 if (!org)
67 return NULL;
68
69 e = malloc(sizeof(*org));
70 memcpy(e, org, sizeof(*org));
71 switch (org->type) {
72 case E_SYMBOL:
73 e->left = org->left;
74 break;
75 case E_NOT:
76 e->left.expr = expr_copy(org->left.expr);
77 break;
78 case E_EQUAL:
79 case E_UNEQUAL:
80 e->left.sym = org->left.sym;
81 e->right.sym = org->right.sym;
82 break;
83 case E_AND:
84 case E_OR:
85 case E_LIST:
86 e->left.expr = expr_copy(org->left.expr);
87 e->right.expr = expr_copy(org->right.expr);
88 break;
89 default:
90 printf("can't copy type %d\n", e->type);
91 free(e);
92 e = NULL;
93 break;
94 }
95
96 return e;
97}
98
99void expr_free(struct expr *e)
100{
101 if (!e)
102 return;
103
104 switch (e->type) {
105 case E_SYMBOL:
106 break;
107 case E_NOT:
108 expr_free(e->left.expr);
109 return;
110 case E_EQUAL:
111 case E_UNEQUAL:
112 break;
113 case E_OR:
114 case E_AND:
115 expr_free(e->left.expr);
116 expr_free(e->right.expr);
117 break;
118 default:
119 printf("how to free type %d?\n", e->type);
120 break;
121 }
122 free(e);
123}
124
125static int trans_count;
126
127#define e1 (*ep1)
128#define e2 (*ep2)
129
130static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
131{
132 if (e1->type == type) {
133 __expr_eliminate_eq(type, &e1->left.expr, &e2);
134 __expr_eliminate_eq(type, &e1->right.expr, &e2);
135 return;
136 }
137 if (e2->type == type) {
138 __expr_eliminate_eq(type, &e1, &e2->left.expr);
139 __expr_eliminate_eq(type, &e1, &e2->right.expr);
140 return;
141 }
142 if (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
143 e1->left.sym == e2->left.sym &&
144 (e1->left.sym == &symbol_yes || e1->left.sym == &symbol_no))
145 return;
146 if (!expr_eq(e1, e2))
147 return;
148 trans_count++;
149 expr_free(e1); expr_free(e2);
150 switch (type) {
151 case E_OR:
152 e1 = expr_alloc_symbol(&symbol_no);
153 e2 = expr_alloc_symbol(&symbol_no);
154 break;
155 case E_AND:
156 e1 = expr_alloc_symbol(&symbol_yes);
157 e2 = expr_alloc_symbol(&symbol_yes);
158 break;
159 default:
160 ;
161 }
162}
163
164void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
165{
166 if (!e1 || !e2)
167 return;
168 switch (e1->type) {
169 case E_OR:
170 case E_AND:
171 __expr_eliminate_eq(e1->type, ep1, ep2);
172 default:
173 ;
174 }
175 if (e1->type != e2->type) switch (e2->type) {
176 case E_OR:
177 case E_AND:
178 __expr_eliminate_eq(e2->type, ep1, ep2);
179 default:
180 ;
181 }
182 e1 = expr_eliminate_yn(e1);
183 e2 = expr_eliminate_yn(e2);
184}
185
186#undef e1
187#undef e2
188
189int expr_eq(struct expr *e1, struct expr *e2)
190{
191 int res, old_count;
192
193 if (e1->type != e2->type)
194 return 0;
195 switch (e1->type) {
196 case E_EQUAL:
197 case E_UNEQUAL:
198 return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
199 case E_SYMBOL:
200 return e1->left.sym == e2->left.sym;
201 case E_NOT:
202 return expr_eq(e1->left.expr, e2->left.expr);
203 case E_AND:
204 case E_OR:
205 e1 = expr_copy(e1);
206 e2 = expr_copy(e2);
207 old_count = trans_count;
208 expr_eliminate_eq(&e1, &e2);
209 res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
210 e1->left.sym == e2->left.sym);
211 expr_free(e1);
212 expr_free(e2);
213 trans_count = old_count;
214 return res;
215 case E_LIST:
216 case E_RANGE:
217 case E_NONE:
218 /* panic */;
219 }
220
221 if (DEBUG_EXPR) {
222 expr_fprint(e1, stdout);
223 printf(" = ");
224 expr_fprint(e2, stdout);
225 printf(" ?\n");
226 }
227
228 return 0;
229}
230
231struct expr *expr_eliminate_yn(struct expr *e)
232{
233 struct expr *tmp;
234
235 if (e) switch (e->type) {
236 case E_AND:
237 e->left.expr = expr_eliminate_yn(e->left.expr);
238 e->right.expr = expr_eliminate_yn(e->right.expr);
239 if (e->left.expr->type == E_SYMBOL) {
240 if (e->left.expr->left.sym == &symbol_no) {
241 expr_free(e->left.expr);
242 expr_free(e->right.expr);
243 e->type = E_SYMBOL;
244 e->left.sym = &symbol_no;
245 e->right.expr = NULL;
246 return e;
247 } else if (e->left.expr->left.sym == &symbol_yes) {
248 free(e->left.expr);
249 tmp = e->right.expr;
250 *e = *(e->right.expr);
251 free(tmp);
252 return e;
253 }
254 }
255 if (e->right.expr->type == E_SYMBOL) {
256 if (e->right.expr->left.sym == &symbol_no) {
257 expr_free(e->left.expr);
258 expr_free(e->right.expr);
259 e->type = E_SYMBOL;
260 e->left.sym = &symbol_no;
261 e->right.expr = NULL;
262 return e;
263 } else if (e->right.expr->left.sym == &symbol_yes) {
264 free(e->right.expr);
265 tmp = e->left.expr;
266 *e = *(e->left.expr);
267 free(tmp);
268 return e;
269 }
270 }
271 break;
272 case E_OR:
273 e->left.expr = expr_eliminate_yn(e->left.expr);
274 e->right.expr = expr_eliminate_yn(e->right.expr);
275 if (e->left.expr->type == E_SYMBOL) {
276 if (e->left.expr->left.sym == &symbol_no) {
277 free(e->left.expr);
278 tmp = e->right.expr;
279 *e = *(e->right.expr);
280 free(tmp);
281 return e;
282 } else if (e->left.expr->left.sym == &symbol_yes) {
283 expr_free(e->left.expr);
284 expr_free(e->right.expr);
285 e->type = E_SYMBOL;
286 e->left.sym = &symbol_yes;
287 e->right.expr = NULL;
288 return e;
289 }
290 }
291 if (e->right.expr->type == E_SYMBOL) {
292 if (e->right.expr->left.sym == &symbol_no) {
293 free(e->right.expr);
294 tmp = e->left.expr;
295 *e = *(e->left.expr);
296 free(tmp);
297 return e;
298 } else if (e->right.expr->left.sym == &symbol_yes) {
299 expr_free(e->left.expr);
300 expr_free(e->right.expr);
301 e->type = E_SYMBOL;
302 e->left.sym = &symbol_yes;
303 e->right.expr = NULL;
304 return e;
305 }
306 }
307 break;
308 default:
309 ;
310 }
311 return e;
312}
313
314/*
315 * bool FOO!=n => FOO
316 */
317struct expr *expr_trans_bool(struct expr *e)
318{
319 if (!e)
320 return NULL;
321 switch (e->type) {
322 case E_AND:
323 case E_OR:
324 case E_NOT:
325 e->left.expr = expr_trans_bool(e->left.expr);
326 e->right.expr = expr_trans_bool(e->right.expr);
327 break;
328 case E_UNEQUAL:
329 // FOO!=n -> FOO
330 if (e->left.sym->type == S_TRISTATE) {
331 if (e->right.sym == &symbol_no) {
332 e->type = E_SYMBOL;
333 e->right.sym = NULL;
334 }
335 }
336 break;
337 default:
338 ;
339 }
340 return e;
341}
342
343/*
344 * e1 || e2 -> ?
345 */
346static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
347{
348 struct expr *tmp;
349 struct symbol *sym1, *sym2;
350
351 if (expr_eq(e1, e2))
352 return expr_copy(e1);
353 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
354 return NULL;
355 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
356 return NULL;
357 if (e1->type == E_NOT) {
358 tmp = e1->left.expr;
359 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
360 return NULL;
361 sym1 = tmp->left.sym;
362 } else
363 sym1 = e1->left.sym;
364 if (e2->type == E_NOT) {
365 if (e2->left.expr->type != E_SYMBOL)
366 return NULL;
367 sym2 = e2->left.expr->left.sym;
368 } else
369 sym2 = e2->left.sym;
370 if (sym1 != sym2)
371 return NULL;
372 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
373 return NULL;
374 if (sym1->type == S_TRISTATE) {
375 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
376 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
377 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
378 // (a='y') || (a='m') -> (a!='n')
379 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
380 }
381 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
382 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
383 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
384 // (a='y') || (a='n') -> (a!='m')
385 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
386 }
387 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
388 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
389 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
390 // (a='m') || (a='n') -> (a!='y')
391 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
392 }
393 }
394 if (sym1->type == S_BOOLEAN && sym1 == sym2) {
395 if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
396 (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
397 return expr_alloc_symbol(&symbol_yes);
398 }
399
400 if (DEBUG_EXPR) {
401 printf("optimize (");
402 expr_fprint(e1, stdout);
403 printf(") || (");
404 expr_fprint(e2, stdout);
405 printf(")?\n");
406 }
407 return NULL;
408}
409
410static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
411{
412 struct expr *tmp;
413 struct symbol *sym1, *sym2;
414
415 if (expr_eq(e1, e2))
416 return expr_copy(e1);
417 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
418 return NULL;
419 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
420 return NULL;
421 if (e1->type == E_NOT) {
422 tmp = e1->left.expr;
423 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
424 return NULL;
425 sym1 = tmp->left.sym;
426 } else
427 sym1 = e1->left.sym;
428 if (e2->type == E_NOT) {
429 if (e2->left.expr->type != E_SYMBOL)
430 return NULL;
431 sym2 = e2->left.expr->left.sym;
432 } else
433 sym2 = e2->left.sym;
434 if (sym1 != sym2)
435 return NULL;
436 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
437 return NULL;
438
439 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
440 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
441 // (a) && (a='y') -> (a='y')
442 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
443
444 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
445 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
446 // (a) && (a!='n') -> (a)
447 return expr_alloc_symbol(sym1);
448
449 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
450 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
451 // (a) && (a!='m') -> (a='y')
452 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
453
454 if (sym1->type == S_TRISTATE) {
455 if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
456 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
457 sym2 = e1->right.sym;
458 if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
459 return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
460 : expr_alloc_symbol(&symbol_no);
461 }
462 if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
463 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
464 sym2 = e2->right.sym;
465 if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
466 return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
467 : expr_alloc_symbol(&symbol_no);
468 }
469 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
470 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
471 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
472 // (a!='y') && (a!='n') -> (a='m')
473 return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
474
475 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
476 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
477 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
478 // (a!='y') && (a!='m') -> (a='n')
479 return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
480
481 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
482 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
483 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
484 // (a!='m') && (a!='n') -> (a='m')
485 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
486
487 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
488 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
489 (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
490 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
491 return NULL;
492 }
493
494 if (DEBUG_EXPR) {
495 printf("optimize (");
496 expr_fprint(e1, stdout);
497 printf(") && (");
498 expr_fprint(e2, stdout);
499 printf(")?\n");
500 }
501 return NULL;
502}
503
504static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
505{
506#define e1 (*ep1)
507#define e2 (*ep2)
508 struct expr *tmp;
509
510 if (e1->type == type) {
511 expr_eliminate_dups1(type, &e1->left.expr, &e2);
512 expr_eliminate_dups1(type, &e1->right.expr, &e2);
513 return;
514 }
515 if (e2->type == type) {
516 expr_eliminate_dups1(type, &e1, &e2->left.expr);
517 expr_eliminate_dups1(type, &e1, &e2->right.expr);
518 return;
519 }
520 if (e1 == e2)
521 return;
522
523 switch (e1->type) {
524 case E_OR: case E_AND:
525 expr_eliminate_dups1(e1->type, &e1, &e1);
526 default:
527 ;
528 }
529
530 switch (type) {
531 case E_OR:
532 tmp = expr_join_or(e1, e2);
533 if (tmp) {
534 expr_free(e1); expr_free(e2);
535 e1 = expr_alloc_symbol(&symbol_no);
536 e2 = tmp;
537 trans_count++;
538 }
539 break;
540 case E_AND:
541 tmp = expr_join_and(e1, e2);
542 if (tmp) {
543 expr_free(e1); expr_free(e2);
544 e1 = expr_alloc_symbol(&symbol_yes);
545 e2 = tmp;
546 trans_count++;
547 }
548 break;
549 default:
550 ;
551 }
552#undef e1
553#undef e2
554}
555
556static void expr_eliminate_dups2(enum expr_type type, struct expr **ep1, struct expr **ep2)
557{
558#define e1 (*ep1)
559#define e2 (*ep2)
560 struct expr *tmp, *tmp1, *tmp2;
561
562 if (e1->type == type) {
563 expr_eliminate_dups2(type, &e1->left.expr, &e2);
564 expr_eliminate_dups2(type, &e1->right.expr, &e2);
565 return;
566 }
567 if (e2->type == type) {
568 expr_eliminate_dups2(type, &e1, &e2->left.expr);
569 expr_eliminate_dups2(type, &e1, &e2->right.expr);
570 }
571 if (e1 == e2)
572 return;
573
574 switch (e1->type) {
575 case E_OR:
576 expr_eliminate_dups2(e1->type, &e1, &e1);
577 // (FOO || BAR) && (!FOO && !BAR) -> n
578 tmp1 = expr_transform(expr_alloc_one(E_NOT, expr_copy(e1)));
579 tmp2 = expr_copy(e2);
580 tmp = expr_extract_eq_and(&tmp1, &tmp2);
581 if (expr_is_yes(tmp1)) {
582 expr_free(e1);
583 e1 = expr_alloc_symbol(&symbol_no);
584 trans_count++;
585 }
586 expr_free(tmp2);
587 expr_free(tmp1);
588 expr_free(tmp);
589 break;
590 case E_AND:
591 expr_eliminate_dups2(e1->type, &e1, &e1);
592 // (FOO && BAR) || (!FOO || !BAR) -> y
593 tmp1 = expr_transform(expr_alloc_one(E_NOT, expr_copy(e1)));
594 tmp2 = expr_copy(e2);
595 tmp = expr_extract_eq_or(&tmp1, &tmp2);
596 if (expr_is_no(tmp1)) {
597 expr_free(e1);
598 e1 = expr_alloc_symbol(&symbol_yes);
599 trans_count++;
600 }
601 expr_free(tmp2);
602 expr_free(tmp1);
603 expr_free(tmp);
604 break;
605 default:
606 ;
607 }
608#undef e1
609#undef e2
610}
611
612struct expr *expr_eliminate_dups(struct expr *e)
613{
614 int oldcount;
615 if (!e)
616 return e;
617
618 oldcount = trans_count;
619 while (1) {
620 trans_count = 0;
621 switch (e->type) {
622 case E_OR: case E_AND:
623 expr_eliminate_dups1(e->type, &e, &e);
624 expr_eliminate_dups2(e->type, &e, &e);
625 default:
626 ;
627 }
628 if (!trans_count)
629 break;
630 e = expr_eliminate_yn(e);
631 }
632 trans_count = oldcount;
633 return e;
634}
635
636struct expr *expr_transform(struct expr *e)
637{
638 struct expr *tmp;
639
640 if (!e)
641 return NULL;
642 switch (e->type) {
643 case E_EQUAL:
644 case E_UNEQUAL:
645 case E_SYMBOL:
646 case E_LIST:
647 break;
648 default:
649 e->left.expr = expr_transform(e->left.expr);
650 e->right.expr = expr_transform(e->right.expr);
651 }
652
653 switch (e->type) {
654 case E_EQUAL:
655 if (e->left.sym->type != S_BOOLEAN)
656 break;
657 if (e->right.sym == &symbol_no) {
658 e->type = E_NOT;
659 e->left.expr = expr_alloc_symbol(e->left.sym);
660 e->right.sym = NULL;
661 break;
662 }
663 if (e->right.sym == &symbol_mod) {
664 printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
665 e->type = E_SYMBOL;
666 e->left.sym = &symbol_no;
667 e->right.sym = NULL;
668 break;
669 }
670 if (e->right.sym == &symbol_yes) {
671 e->type = E_SYMBOL;
672 e->right.sym = NULL;
673 break;
674 }
675 break;
676 case E_UNEQUAL:
677 if (e->left.sym->type != S_BOOLEAN)
678 break;
679 if (e->right.sym == &symbol_no) {
680 e->type = E_SYMBOL;
681 e->right.sym = NULL;
682 break;
683 }
684 if (e->right.sym == &symbol_mod) {
685 printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
686 e->type = E_SYMBOL;
687 e->left.sym = &symbol_yes;
688 e->right.sym = NULL;
689 break;
690 }
691 if (e->right.sym == &symbol_yes) {
692 e->type = E_NOT;
693 e->left.expr = expr_alloc_symbol(e->left.sym);
694 e->right.sym = NULL;
695 break;
696 }
697 break;
698 case E_NOT:
699 switch (e->left.expr->type) {
700 case E_NOT:
701 // !!a -> a
702 tmp = e->left.expr->left.expr;
703 free(e->left.expr);
704 free(e);
705 e = tmp;
706 e = expr_transform(e);
707 break;
708 case E_EQUAL:
709 case E_UNEQUAL:
710 // !a='x' -> a!='x'
711 tmp = e->left.expr;
712 free(e);
713 e = tmp;
714 e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
715 break;
716 case E_OR:
717 // !(a || b) -> !a && !b
718 tmp = e->left.expr;
719 e->type = E_AND;
720 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
721 tmp->type = E_NOT;
722 tmp->right.expr = NULL;
723 e = expr_transform(e);
724 break;
725 case E_AND:
726 // !(a && b) -> !a || !b
727 tmp = e->left.expr;
728 e->type = E_OR;
729 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
730 tmp->type = E_NOT;
731 tmp->right.expr = NULL;
732 e = expr_transform(e);
733 break;
734 case E_SYMBOL:
735 if (e->left.expr->left.sym == &symbol_yes) {
736 // !'y' -> 'n'
737 tmp = e->left.expr;
738 free(e);
739 e = tmp;
740 e->type = E_SYMBOL;
741 e->left.sym = &symbol_no;
742 break;
743 }
744 if (e->left.expr->left.sym == &symbol_mod) {
745 // !'m' -> 'm'
746 tmp = e->left.expr;
747 free(e);
748 e = tmp;
749 e->type = E_SYMBOL;
750 e->left.sym = &symbol_mod;
751 break;
752 }
753 if (e->left.expr->left.sym == &symbol_no) {
754 // !'n' -> 'y'
755 tmp = e->left.expr;
756 free(e);
757 e = tmp;
758 e->type = E_SYMBOL;
759 e->left.sym = &symbol_yes;
760 break;
761 }
762 break;
763 default:
764 ;
765 }
766 break;
767 default:
768 ;
769 }
770 return e;
771}
772
773int expr_contains_symbol(struct expr *dep, struct symbol *sym)
774{
775 if (!dep)
776 return 0;
777
778 switch (dep->type) {
779 case E_AND:
780 case E_OR:
781 return expr_contains_symbol(dep->left.expr, sym) ||
782 expr_contains_symbol(dep->right.expr, sym);
783 case E_SYMBOL:
784 return dep->left.sym == sym;
785 case E_EQUAL:
786 case E_UNEQUAL:
787 return dep->left.sym == sym ||
788 dep->right.sym == sym;
789 case E_NOT:
790 return expr_contains_symbol(dep->left.expr, sym);
791 default:
792 ;
793 }
794 return 0;
795}
796
797bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
798{
799 if (!dep)
800 return false;
801
802 switch (dep->type) {
803 case E_AND:
804 return expr_depends_symbol(dep->left.expr, sym) ||
805 expr_depends_symbol(dep->right.expr, sym);
806 case E_SYMBOL:
807 return dep->left.sym == sym;
808 case E_EQUAL:
809 if (dep->left.sym == sym) {
810 if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
811 return true;
812 }
813 break;
814 case E_UNEQUAL:
815 if (dep->left.sym == sym) {
816 if (dep->right.sym == &symbol_no)
817 return true;
818 }
819 break;
820 default:
821 ;
822 }
823 return false;
824}
825
826struct expr *expr_extract_eq_and(struct expr **ep1, struct expr **ep2)
827{
828 struct expr *tmp = NULL;
829 expr_extract_eq(E_AND, &tmp, ep1, ep2);
830 if (tmp) {
831 *ep1 = expr_eliminate_yn(*ep1);
832 *ep2 = expr_eliminate_yn(*ep2);
833 }
834 return tmp;
835}
836
837struct expr *expr_extract_eq_or(struct expr **ep1, struct expr **ep2)
838{
839 struct expr *tmp = NULL;
840 expr_extract_eq(E_OR, &tmp, ep1, ep2);
841 if (tmp) {
842 *ep1 = expr_eliminate_yn(*ep1);
843 *ep2 = expr_eliminate_yn(*ep2);
844 }
845 return tmp;
846}
847
848void expr_extract_eq(enum expr_type type, struct expr **ep, struct expr **ep1, struct expr **ep2)
849{
850#define e1 (*ep1)
851#define e2 (*ep2)
852 if (e1->type == type) {
853 expr_extract_eq(type, ep, &e1->left.expr, &e2);
854 expr_extract_eq(type, ep, &e1->right.expr, &e2);
855 return;
856 }
857 if (e2->type == type) {
858 expr_extract_eq(type, ep, ep1, &e2->left.expr);
859 expr_extract_eq(type, ep, ep1, &e2->right.expr);
860 return;
861 }
862 if (expr_eq(e1, e2)) {
863 *ep = *ep ? expr_alloc_two(type, *ep, e1) : e1;
864 expr_free(e2);
865 if (type == E_AND) {
866 e1 = expr_alloc_symbol(&symbol_yes);
867 e2 = expr_alloc_symbol(&symbol_yes);
868 } else if (type == E_OR) {
869 e1 = expr_alloc_symbol(&symbol_no);
870 e2 = expr_alloc_symbol(&symbol_no);
871 }
872 }
873#undef e1
874#undef e2
875}
876
877struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
878{
879 struct expr *e1, *e2;
880
881 if (!e) {
882 e = expr_alloc_symbol(sym);
883 if (type == E_UNEQUAL)
884 e = expr_alloc_one(E_NOT, e);
885 return e;
886 }
887 switch (e->type) {
888 case E_AND:
889 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
890 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
891 if (sym == &symbol_yes)
892 e = expr_alloc_two(E_AND, e1, e2);
893 if (sym == &symbol_no)
894 e = expr_alloc_two(E_OR, e1, e2);
895 if (type == E_UNEQUAL)
896 e = expr_alloc_one(E_NOT, e);
897 return e;
898 case E_OR:
899 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
900 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
901 if (sym == &symbol_yes)
902 e = expr_alloc_two(E_OR, e1, e2);
903 if (sym == &symbol_no)
904 e = expr_alloc_two(E_AND, e1, e2);
905 if (type == E_UNEQUAL)
906 e = expr_alloc_one(E_NOT, e);
907 return e;
908 case E_NOT:
909 return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
910 case E_UNEQUAL:
911 case E_EQUAL:
912 if (type == E_EQUAL) {
913 if (sym == &symbol_yes)
914 return expr_copy(e);
915 if (sym == &symbol_mod)
916 return expr_alloc_symbol(&symbol_no);
917 if (sym == &symbol_no)
918 return expr_alloc_one(E_NOT, expr_copy(e));
919 } else {
920 if (sym == &symbol_yes)
921 return expr_alloc_one(E_NOT, expr_copy(e));
922 if (sym == &symbol_mod)
923 return expr_alloc_symbol(&symbol_yes);
924 if (sym == &symbol_no)
925 return expr_copy(e);
926 }
927 break;
928 case E_SYMBOL:
929 return expr_alloc_comp(type, e->left.sym, sym);
930 case E_LIST:
931 case E_RANGE:
932 case E_NONE:
933 /* panic */;
934 }
935 return NULL;
936}
937
938tristate expr_calc_value(struct expr *e)
939{
940 tristate val1, val2;
941 const char *str1, *str2;
942
943 if (!e)
944 return yes;
945
946 switch (e->type) {
947 case E_SYMBOL:
948 sym_calc_value(e->left.sym);
949 return e->left.sym->curr.tri;
950 case E_AND:
951 val1 = expr_calc_value(e->left.expr);
952 val2 = expr_calc_value(e->right.expr);
953 return EXPR_AND(val1, val2);
954 case E_OR:
955 val1 = expr_calc_value(e->left.expr);
956 val2 = expr_calc_value(e->right.expr);
957 return EXPR_OR(val1, val2);
958 case E_NOT:
959 val1 = expr_calc_value(e->left.expr);
960 return EXPR_NOT(val1);
961 case E_EQUAL:
962 sym_calc_value(e->left.sym);
963 sym_calc_value(e->right.sym);
964 str1 = sym_get_string_value(e->left.sym);
965 str2 = sym_get_string_value(e->right.sym);
966 return !strcmp(str1, str2) ? yes : no;
967 case E_UNEQUAL:
968 sym_calc_value(e->left.sym);
969 sym_calc_value(e->right.sym);
970 str1 = sym_get_string_value(e->left.sym);
971 str2 = sym_get_string_value(e->right.sym);
972 return !strcmp(str1, str2) ? no : yes;
973 default:
974 printf("expr_calc_value: %d?\n", e->type);
975 return no;
976 }
977}
978
979int expr_compare_type(enum expr_type t1, enum expr_type t2)
980{
981#if 0
982 return 1;
983#else
984 if (t1 == t2)
985 return 0;
986 switch (t1) {
987 case E_EQUAL:
988 case E_UNEQUAL:
989 if (t2 == E_NOT)
990 return 1;
991 case E_NOT:
992 if (t2 == E_AND)
993 return 1;
994 case E_AND:
995 if (t2 == E_OR)
996 return 1;
997 case E_OR:
998 if (t2 == E_LIST)
999 return 1;
1000 case E_LIST:
1001 if (t2 == 0)
1002 return 1;
1003 default:
1004 return -1;
1005 }
1006 printf("[%dgt%d?]", t1, t2);
1007 return 0;
1008#endif
1009}
1010
1011static inline struct expr *
1012expr_get_leftmost_symbol(const struct expr *e)
1013{
1014
1015 if (e == NULL)
1016 return NULL;
1017
1018 while (e->type != E_SYMBOL)
1019 e = e->left.expr;
1020
1021 return expr_copy(e);
1022}
1023
1024/*
1025 * Given expression `e1' and `e2', returns the leaf of the longest
1026 * sub-expression of `e1' not containing 'e2.
1027 */
1028struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2)
1029{
1030 struct expr *ret;
1031
1032 switch (e1->type) {
1033 case E_OR:
1034 return expr_alloc_and(
1035 expr_simplify_unmet_dep(e1->left.expr, e2),
1036 expr_simplify_unmet_dep(e1->right.expr, e2));
1037 case E_AND: {
1038 struct expr *e;
1039 e = expr_alloc_and(expr_copy(e1), expr_copy(e2));
1040 e = expr_eliminate_dups(e);
1041 ret = (!expr_eq(e, e1)) ? e1 : NULL;
1042 expr_free(e);
1043 break;
1044 }
1045 default:
1046 ret = e1;
1047 break;
1048 }
1049
1050 return expr_get_leftmost_symbol(ret);
1051}
1052
1053void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken)
1054{
1055 if (!e) {
1056 fn(data, NULL, "y");
1057 return;
1058 }
1059
1060 if (expr_compare_type(prevtoken, e->type) > 0)
1061 fn(data, NULL, "(");
1062 switch (e->type) {
1063 case E_SYMBOL:
1064 if (e->left.sym->name)
1065 fn(data, e->left.sym, e->left.sym->name);
1066 else
1067 fn(data, NULL, "<choice>");
1068 break;
1069 case E_NOT:
1070 fn(data, NULL, "!");
1071 expr_print(e->left.expr, fn, data, E_NOT);
1072 break;
1073 case E_EQUAL:
1074 if (e->left.sym->name)
1075 fn(data, e->left.sym, e->left.sym->name);
1076 else
1077 fn(data, NULL, "<choice>");
1078 fn(data, NULL, "=");
1079 fn(data, e->right.sym, e->right.sym->name);
1080 break;
1081 case E_UNEQUAL:
1082 if (e->left.sym->name)
1083 fn(data, e->left.sym, e->left.sym->name);
1084 else
1085 fn(data, NULL, "<choice>");
1086 fn(data, NULL, "!=");
1087 fn(data, e->right.sym, e->right.sym->name);
1088 break;
1089 case E_OR:
1090 expr_print(e->left.expr, fn, data, E_OR);
1091 fn(data, NULL, " || ");
1092 expr_print(e->right.expr, fn, data, E_OR);
1093 break;
1094 case E_AND:
1095 expr_print(e->left.expr, fn, data, E_AND);
1096 fn(data, NULL, " && ");
1097 expr_print(e->right.expr, fn, data, E_AND);
1098 break;
1099 case E_LIST:
1100 fn(data, e->right.sym, e->right.sym->name);
1101 if (e->left.expr) {
1102 fn(data, NULL, " ^ ");
1103 expr_print(e->left.expr, fn, data, E_LIST);
1104 }
1105 break;
1106 case E_RANGE:
1107 fn(data, NULL, "[");
1108 fn(data, e->left.sym, e->left.sym->name);
1109 fn(data, NULL, " ");
1110 fn(data, e->right.sym, e->right.sym->name);
1111 fn(data, NULL, "]");
1112 break;
1113 default:
1114 {
1115 char buf[32];
1116 sprintf(buf, "<unknown type %d>", e->type);
1117 fn(data, NULL, buf);
1118 break;
1119 }
1120 }
1121 if (expr_compare_type(prevtoken, e->type) > 0)
1122 fn(data, NULL, ")");
1123}
1124
1125static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
1126{
1127 xfwrite(str, strlen(str), 1, data);
1128}
1129
1130void expr_fprint(struct expr *e, FILE *out)
1131{
1132 expr_print(e, expr_print_file_helper, out, E_NONE);
1133}
1134
1135static void expr_print_gstr_helper(void *data, struct symbol *sym, const char *str)
1136{
1137 struct gstr *gs = (struct gstr*)data;
1138 const char *sym_str = NULL;
1139
1140 if (sym)
1141 sym_str = sym_get_string_value(sym);
1142
1143 if (gs->max_width) {
1144 unsigned extra_length = strlen(str);
1145 const char *last_cr = strrchr(gs->s, '\n');
1146 unsigned last_line_length;
1147
1148 if (sym_str)
1149 extra_length += 4 + strlen(sym_str);
1150
1151 if (!last_cr)
1152 last_cr = gs->s;
1153
1154 last_line_length = strlen(gs->s) - (last_cr - gs->s);
1155
1156 if ((last_line_length + extra_length) > gs->max_width)
1157 str_append(gs, "\\\n");
1158 }
1159
1160 str_append(gs, str);
1161 if (sym && sym->type != S_UNKNOWN)
1162 str_printf(gs, " [=%s]", sym_str);
1163}
1164
1165void expr_gstr_print(struct expr *e, struct gstr *gs)
1166{
1167 expr_print(e, expr_print_gstr_helper, gs, E_NONE);
1168}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
4 */
5
6#include <ctype.h>
7#include <errno.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11
12#include <hash.h>
13#include <xalloc.h>
14#include "internal.h"
15#include "lkc.h"
16
17#define DEBUG_EXPR 0
18
19HASHTABLE_DEFINE(expr_hashtable, EXPR_HASHSIZE);
20
21static struct expr *expr_eliminate_yn(struct expr *e);
22
23/**
24 * expr_lookup - return the expression with the given type and sub-nodes
25 * This looks up an expression with the specified type and sub-nodes. If such
26 * an expression is found in the hash table, it is returned. Otherwise, a new
27 * expression node is allocated and added to the hash table.
28 * @type: expression type
29 * @l: left node
30 * @r: right node
31 * return: expression
32 */
33static struct expr *expr_lookup(enum expr_type type, void *l, void *r)
34{
35 struct expr *e;
36 int hash;
37
38 hash = hash_32((unsigned int)type ^ hash_ptr(l) ^ hash_ptr(r));
39
40 hash_for_each_possible(expr_hashtable, e, node, hash) {
41 if (e->type == type && e->left._initdata == l &&
42 e->right._initdata == r)
43 return e;
44 }
45
46 e = xmalloc(sizeof(*e));
47 e->type = type;
48 e->left._initdata = l;
49 e->right._initdata = r;
50 e->val_is_valid = false;
51
52 hash_add(expr_hashtable, &e->node, hash);
53
54 return e;
55}
56
57struct expr *expr_alloc_symbol(struct symbol *sym)
58{
59 return expr_lookup(E_SYMBOL, sym, NULL);
60}
61
62struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
63{
64 return expr_lookup(type, ce, NULL);
65}
66
67struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
68{
69 return expr_lookup(type, e1, e2);
70}
71
72struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
73{
74 return expr_lookup(type, s1, s2);
75}
76
77struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
78{
79 if (!e1)
80 return e2;
81 return e2 ? expr_alloc_two(E_AND, e1, e2) : e1;
82}
83
84struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
85{
86 if (!e1)
87 return e2;
88 return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
89}
90
91static int trans_count;
92
93/*
94 * expr_eliminate_eq() helper.
95 *
96 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
97 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
98 * against all other leaves. Two equal leaves are both replaced with either 'y'
99 * or 'n' as appropriate for 'type', to be eliminated later.
100 */
101static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
102{
103 struct expr *l, *r;
104
105 /* Recurse down to leaves */
106
107 if ((*ep1)->type == type) {
108 l = (*ep1)->left.expr;
109 r = (*ep1)->right.expr;
110 __expr_eliminate_eq(type, &l, ep2);
111 __expr_eliminate_eq(type, &r, ep2);
112 *ep1 = expr_alloc_two(type, l, r);
113 return;
114 }
115 if ((*ep2)->type == type) {
116 l = (*ep2)->left.expr;
117 r = (*ep2)->right.expr;
118 __expr_eliminate_eq(type, ep1, &l);
119 __expr_eliminate_eq(type, ep1, &r);
120 *ep2 = expr_alloc_two(type, l, r);
121 return;
122 }
123
124 /* *ep1 and *ep2 are leaves. Compare them. */
125
126 if ((*ep1)->type == E_SYMBOL && (*ep2)->type == E_SYMBOL &&
127 (*ep1)->left.sym == (*ep2)->left.sym &&
128 ((*ep1)->left.sym == &symbol_yes || (*ep1)->left.sym == &symbol_no))
129 return;
130 if (!expr_eq(*ep1, *ep2))
131 return;
132
133 /* *ep1 and *ep2 are equal leaves. Prepare them for elimination. */
134
135 trans_count++;
136 switch (type) {
137 case E_OR:
138 *ep1 = expr_alloc_symbol(&symbol_no);
139 *ep2 = expr_alloc_symbol(&symbol_no);
140 break;
141 case E_AND:
142 *ep1 = expr_alloc_symbol(&symbol_yes);
143 *ep2 = expr_alloc_symbol(&symbol_yes);
144 break;
145 default:
146 ;
147 }
148}
149
150/*
151 * Rewrites the expressions 'ep1' and 'ep2' to remove operands common to both.
152 * Example reductions:
153 *
154 * ep1: A && B -> ep1: y
155 * ep2: A && B && C -> ep2: C
156 *
157 * ep1: A || B -> ep1: n
158 * ep2: A || B || C -> ep2: C
159 *
160 * ep1: A && (B && FOO) -> ep1: FOO
161 * ep2: (BAR && B) && A -> ep2: BAR
162 *
163 * ep1: A && (B || C) -> ep1: y
164 * ep2: (C || B) && A -> ep2: y
165 *
166 * Comparisons are done between all operands at the same "level" of && or ||.
167 * For example, in the expression 'e1 && (e2 || e3) && (e4 || e5)', the
168 * following operands will be compared:
169 *
170 * - 'e1', 'e2 || e3', and 'e4 || e5', against each other
171 * - e2 against e3
172 * - e4 against e5
173 *
174 * Parentheses are irrelevant within a single level. 'e1 && (e2 && e3)' and
175 * '(e1 && e2) && e3' are both a single level.
176 *
177 * See __expr_eliminate_eq() as well.
178 */
179void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
180{
181 if (!*ep1 || !*ep2)
182 return;
183 switch ((*ep1)->type) {
184 case E_OR:
185 case E_AND:
186 __expr_eliminate_eq((*ep1)->type, ep1, ep2);
187 default:
188 ;
189 }
190 if ((*ep1)->type != (*ep2)->type) switch ((*ep2)->type) {
191 case E_OR:
192 case E_AND:
193 __expr_eliminate_eq((*ep2)->type, ep1, ep2);
194 default:
195 ;
196 }
197 *ep1 = expr_eliminate_yn(*ep1);
198 *ep2 = expr_eliminate_yn(*ep2);
199}
200
201/*
202 * Returns true if 'e1' and 'e2' are equal, after minor simplification. Two
203 * &&/|| expressions are considered equal if every operand in one expression
204 * equals some operand in the other (operands do not need to appear in the same
205 * order), recursively.
206 */
207bool expr_eq(struct expr *e1, struct expr *e2)
208{
209 int old_count;
210 bool res;
211
212 /*
213 * A NULL expr is taken to be yes, but there's also a different way to
214 * represent yes. expr_is_yes() checks for either representation.
215 */
216 if (!e1 || !e2)
217 return expr_is_yes(e1) && expr_is_yes(e2);
218
219 if (e1->type != e2->type)
220 return false;
221 switch (e1->type) {
222 case E_EQUAL:
223 case E_GEQ:
224 case E_GTH:
225 case E_LEQ:
226 case E_LTH:
227 case E_UNEQUAL:
228 return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
229 case E_SYMBOL:
230 return e1->left.sym == e2->left.sym;
231 case E_NOT:
232 return expr_eq(e1->left.expr, e2->left.expr);
233 case E_AND:
234 case E_OR:
235 old_count = trans_count;
236 expr_eliminate_eq(&e1, &e2);
237 res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
238 e1->left.sym == e2->left.sym);
239 trans_count = old_count;
240 return res;
241 case E_RANGE:
242 case E_NONE:
243 /* panic */;
244 }
245
246 if (DEBUG_EXPR) {
247 expr_fprint(e1, stdout);
248 printf(" = ");
249 expr_fprint(e2, stdout);
250 printf(" ?\n");
251 }
252
253 return false;
254}
255
256/*
257 * Recursively performs the following simplifications (as well as the
258 * corresponding simplifications with swapped operands):
259 *
260 * expr && n -> n
261 * expr && y -> expr
262 * expr || n -> expr
263 * expr || y -> y
264 *
265 * Returns the optimized expression.
266 */
267static struct expr *expr_eliminate_yn(struct expr *e)
268{
269 struct expr *l, *r;
270
271 if (e) switch (e->type) {
272 case E_AND:
273 l = expr_eliminate_yn(e->left.expr);
274 r = expr_eliminate_yn(e->right.expr);
275 if (l->type == E_SYMBOL) {
276 if (l->left.sym == &symbol_no)
277 return l;
278 else if (l->left.sym == &symbol_yes)
279 return r;
280 }
281 if (r->type == E_SYMBOL) {
282 if (r->left.sym == &symbol_no)
283 return r;
284 else if (r->left.sym == &symbol_yes)
285 return l;
286 }
287 break;
288 case E_OR:
289 l = expr_eliminate_yn(e->left.expr);
290 r = expr_eliminate_yn(e->right.expr);
291 if (l->type == E_SYMBOL) {
292 if (l->left.sym == &symbol_no)
293 return r;
294 else if (l->left.sym == &symbol_yes)
295 return l;
296 }
297 if (r->type == E_SYMBOL) {
298 if (r->left.sym == &symbol_no)
299 return l;
300 else if (r->left.sym == &symbol_yes)
301 return r;
302 }
303 break;
304 default:
305 ;
306 }
307 return e;
308}
309
310/*
311 * e1 || e2 -> ?
312 */
313static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
314{
315 struct expr *tmp;
316 struct symbol *sym1, *sym2;
317
318 if (expr_eq(e1, e2))
319 return e1;
320 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
321 return NULL;
322 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
323 return NULL;
324 if (e1->type == E_NOT) {
325 tmp = e1->left.expr;
326 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
327 return NULL;
328 sym1 = tmp->left.sym;
329 } else
330 sym1 = e1->left.sym;
331 if (e2->type == E_NOT) {
332 if (e2->left.expr->type != E_SYMBOL)
333 return NULL;
334 sym2 = e2->left.expr->left.sym;
335 } else
336 sym2 = e2->left.sym;
337 if (sym1 != sym2)
338 return NULL;
339 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
340 return NULL;
341 if (sym1->type == S_TRISTATE) {
342 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
343 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
344 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
345 // (a='y') || (a='m') -> (a!='n')
346 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
347 }
348 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
349 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
350 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
351 // (a='y') || (a='n') -> (a!='m')
352 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
353 }
354 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
355 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
356 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
357 // (a='m') || (a='n') -> (a!='y')
358 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
359 }
360 }
361 if (sym1->type == S_BOOLEAN) {
362 // a || !a -> y
363 if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
364 (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
365 return expr_alloc_symbol(&symbol_yes);
366 }
367
368 if (DEBUG_EXPR) {
369 printf("optimize (");
370 expr_fprint(e1, stdout);
371 printf(") || (");
372 expr_fprint(e2, stdout);
373 printf(")?\n");
374 }
375 return NULL;
376}
377
378static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
379{
380 struct expr *tmp;
381 struct symbol *sym1, *sym2;
382
383 if (expr_eq(e1, e2))
384 return e1;
385 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
386 return NULL;
387 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
388 return NULL;
389 if (e1->type == E_NOT) {
390 tmp = e1->left.expr;
391 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
392 return NULL;
393 sym1 = tmp->left.sym;
394 } else
395 sym1 = e1->left.sym;
396 if (e2->type == E_NOT) {
397 if (e2->left.expr->type != E_SYMBOL)
398 return NULL;
399 sym2 = e2->left.expr->left.sym;
400 } else
401 sym2 = e2->left.sym;
402 if (sym1 != sym2)
403 return NULL;
404 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
405 return NULL;
406
407 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
408 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
409 // (a) && (a='y') -> (a='y')
410 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
411
412 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
413 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
414 // (a) && (a!='n') -> (a)
415 return expr_alloc_symbol(sym1);
416
417 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
418 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
419 // (a) && (a!='m') -> (a='y')
420 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
421
422 if (sym1->type == S_TRISTATE) {
423 if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
424 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
425 sym2 = e1->right.sym;
426 if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
427 return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
428 : expr_alloc_symbol(&symbol_no);
429 }
430 if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
431 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
432 sym2 = e2->right.sym;
433 if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
434 return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
435 : expr_alloc_symbol(&symbol_no);
436 }
437 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
438 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
439 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
440 // (a!='y') && (a!='n') -> (a='m')
441 return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
442
443 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
444 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
445 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
446 // (a!='y') && (a!='m') -> (a='n')
447 return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
448
449 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
450 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
451 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
452 // (a!='m') && (a!='n') -> (a='m')
453 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
454
455 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
456 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
457 (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
458 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
459 return NULL;
460 }
461
462 if (DEBUG_EXPR) {
463 printf("optimize (");
464 expr_fprint(e1, stdout);
465 printf(") && (");
466 expr_fprint(e2, stdout);
467 printf(")?\n");
468 }
469 return NULL;
470}
471
472/*
473 * expr_eliminate_dups() helper.
474 *
475 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
476 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
477 * against all other leaves to look for simplifications.
478 */
479static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
480{
481 struct expr *tmp, *l, *r;
482
483 /* Recurse down to leaves */
484
485 if ((*ep1)->type == type) {
486 l = (*ep1)->left.expr;
487 r = (*ep1)->right.expr;
488 expr_eliminate_dups1(type, &l, ep2);
489 expr_eliminate_dups1(type, &r, ep2);
490 *ep1 = expr_alloc_two(type, l, r);
491 return;
492 }
493 if ((*ep2)->type == type) {
494 l = (*ep2)->left.expr;
495 r = (*ep2)->right.expr;
496 expr_eliminate_dups1(type, ep1, &l);
497 expr_eliminate_dups1(type, ep1, &r);
498 *ep2 = expr_alloc_two(type, l, r);
499 return;
500 }
501
502 /* *ep1 and *ep2 are leaves. Compare and process them. */
503
504 switch (type) {
505 case E_OR:
506 tmp = expr_join_or(*ep1, *ep2);
507 if (tmp) {
508 *ep1 = expr_alloc_symbol(&symbol_no);
509 *ep2 = tmp;
510 trans_count++;
511 }
512 break;
513 case E_AND:
514 tmp = expr_join_and(*ep1, *ep2);
515 if (tmp) {
516 *ep1 = expr_alloc_symbol(&symbol_yes);
517 *ep2 = tmp;
518 trans_count++;
519 }
520 break;
521 default:
522 ;
523 }
524}
525
526/*
527 * Rewrites 'e' in-place to remove ("join") duplicate and other redundant
528 * operands.
529 *
530 * Example simplifications:
531 *
532 * A || B || A -> A || B
533 * A && B && A=y -> A=y && B
534 *
535 * Returns the deduplicated expression.
536 */
537struct expr *expr_eliminate_dups(struct expr *e)
538{
539 int oldcount;
540 if (!e)
541 return e;
542
543 oldcount = trans_count;
544 do {
545 struct expr *l, *r;
546
547 trans_count = 0;
548 switch (e->type) {
549 case E_OR: case E_AND:
550 l = expr_eliminate_dups(e->left.expr);
551 r = expr_eliminate_dups(e->right.expr);
552 expr_eliminate_dups1(e->type, &l, &r);
553 e = expr_alloc_two(e->type, l, r);
554 default:
555 ;
556 }
557 e = expr_eliminate_yn(e);
558 } while (trans_count); /* repeat until we get no more simplifications */
559 trans_count = oldcount;
560 return e;
561}
562
563/*
564 * Performs various simplifications involving logical operators and
565 * comparisons.
566 *
567 * For bool type:
568 * A=n -> !A
569 * A=m -> n
570 * A=y -> A
571 * A!=n -> A
572 * A!=m -> y
573 * A!=y -> !A
574 *
575 * For any type:
576 * !!A -> A
577 * !(A=B) -> A!=B
578 * !(A!=B) -> A=B
579 * !(A<=B) -> A>B
580 * !(A>=B) -> A<B
581 * !(A<B) -> A>=B
582 * !(A>B) -> A<=B
583 * !(A || B) -> !A && !B
584 * !(A && B) -> !A || !B
585 *
586 * For constant:
587 * !y -> n
588 * !m -> m
589 * !n -> y
590 *
591 * Allocates and returns a new expression.
592 */
593struct expr *expr_transform(struct expr *e)
594{
595 if (!e)
596 return NULL;
597 switch (e->type) {
598 case E_EQUAL:
599 case E_GEQ:
600 case E_GTH:
601 case E_LEQ:
602 case E_LTH:
603 case E_UNEQUAL:
604 case E_SYMBOL:
605 break;
606 default:
607 e = expr_alloc_two(e->type,
608 expr_transform(e->left.expr),
609 expr_transform(e->right.expr));
610 }
611
612 switch (e->type) {
613 case E_EQUAL:
614 if (e->left.sym->type != S_BOOLEAN)
615 break;
616 if (e->right.sym == &symbol_no) {
617 // A=n -> !A
618 e = expr_alloc_one(E_NOT, expr_alloc_symbol(e->left.sym));
619 break;
620 }
621 if (e->right.sym == &symbol_mod) {
622 // A=m -> n
623 printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
624 e = expr_alloc_symbol(&symbol_no);
625 break;
626 }
627 if (e->right.sym == &symbol_yes) {
628 // A=y -> A
629 e = expr_alloc_symbol(e->left.sym);
630 break;
631 }
632 break;
633 case E_UNEQUAL:
634 if (e->left.sym->type != S_BOOLEAN)
635 break;
636 if (e->right.sym == &symbol_no) {
637 // A!=n -> A
638 e = expr_alloc_symbol(e->left.sym);
639 break;
640 }
641 if (e->right.sym == &symbol_mod) {
642 // A!=m -> y
643 printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
644 e = expr_alloc_symbol(&symbol_yes);
645 break;
646 }
647 if (e->right.sym == &symbol_yes) {
648 // A!=y -> !A
649 e = expr_alloc_one(E_NOT, e->left.expr);
650 break;
651 }
652 break;
653 case E_NOT:
654 switch (e->left.expr->type) {
655 case E_NOT:
656 // !!A -> A
657 e = e->left.expr->left.expr;
658 break;
659 case E_EQUAL:
660 case E_UNEQUAL:
661 // !(A=B) -> A!=B
662 e = expr_alloc_comp(e->left.expr->type == E_EQUAL ? E_UNEQUAL : E_EQUAL,
663 e->left.expr->left.sym,
664 e->left.expr->right.sym);
665 break;
666 case E_LEQ:
667 case E_GEQ:
668 // !(A<=B) -> A>B
669 e = expr_alloc_comp(e->left.expr->type == E_LEQ ? E_GTH : E_LTH,
670 e->left.expr->left.sym,
671 e->left.expr->right.sym);
672 break;
673 case E_LTH:
674 case E_GTH:
675 // !(A<B) -> A>=B
676 e = expr_alloc_comp(e->left.expr->type == E_LTH ? E_GEQ : E_LEQ,
677 e->left.expr->left.sym,
678 e->left.expr->right.sym);
679 break;
680 case E_OR:
681 // !(A || B) -> !A && !B
682 e = expr_alloc_and(expr_alloc_one(E_NOT, e->left.expr->left.expr),
683 expr_alloc_one(E_NOT, e->left.expr->right.expr));
684 e = expr_transform(e);
685 break;
686 case E_AND:
687 // !(A && B) -> !A || !B
688 e = expr_alloc_or(expr_alloc_one(E_NOT, e->left.expr->left.expr),
689 expr_alloc_one(E_NOT, e->left.expr->right.expr));
690 e = expr_transform(e);
691 break;
692 case E_SYMBOL:
693 if (e->left.expr->left.sym == &symbol_yes)
694 // !'y' -> 'n'
695 e = expr_alloc_symbol(&symbol_no);
696 else if (e->left.expr->left.sym == &symbol_mod)
697 // !'m' -> 'm'
698 e = expr_alloc_symbol(&symbol_mod);
699 else if (e->left.expr->left.sym == &symbol_no)
700 // !'n' -> 'y'
701 e = expr_alloc_symbol(&symbol_yes);
702 break;
703 default:
704 ;
705 }
706 break;
707 default:
708 ;
709 }
710 return e;
711}
712
713bool expr_contains_symbol(struct expr *dep, struct symbol *sym)
714{
715 if (!dep)
716 return false;
717
718 switch (dep->type) {
719 case E_AND:
720 case E_OR:
721 return expr_contains_symbol(dep->left.expr, sym) ||
722 expr_contains_symbol(dep->right.expr, sym);
723 case E_SYMBOL:
724 return dep->left.sym == sym;
725 case E_EQUAL:
726 case E_GEQ:
727 case E_GTH:
728 case E_LEQ:
729 case E_LTH:
730 case E_UNEQUAL:
731 return dep->left.sym == sym ||
732 dep->right.sym == sym;
733 case E_NOT:
734 return expr_contains_symbol(dep->left.expr, sym);
735 default:
736 ;
737 }
738 return false;
739}
740
741bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
742{
743 if (!dep)
744 return false;
745
746 switch (dep->type) {
747 case E_AND:
748 return expr_depends_symbol(dep->left.expr, sym) ||
749 expr_depends_symbol(dep->right.expr, sym);
750 case E_SYMBOL:
751 return dep->left.sym == sym;
752 case E_EQUAL:
753 if (dep->left.sym == sym) {
754 if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
755 return true;
756 }
757 break;
758 case E_UNEQUAL:
759 if (dep->left.sym == sym) {
760 if (dep->right.sym == &symbol_no)
761 return true;
762 }
763 break;
764 default:
765 ;
766 }
767 return false;
768}
769
770/*
771 * Inserts explicit comparisons of type 'type' to symbol 'sym' into the
772 * expression 'e'.
773 *
774 * Examples transformations for type == E_UNEQUAL, sym == &symbol_no:
775 *
776 * A -> A!=n
777 * !A -> A=n
778 * A && B -> !(A=n || B=n)
779 * A || B -> !(A=n && B=n)
780 * A && (B || C) -> !(A=n || (B=n && C=n))
781 *
782 * Allocates and returns a new expression.
783 */
784struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
785{
786 struct expr *e1, *e2;
787
788 if (!e) {
789 e = expr_alloc_symbol(sym);
790 if (type == E_UNEQUAL)
791 e = expr_alloc_one(E_NOT, e);
792 return e;
793 }
794 switch (e->type) {
795 case E_AND:
796 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
797 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
798 if (sym == &symbol_yes)
799 e = expr_alloc_two(E_AND, e1, e2);
800 if (sym == &symbol_no)
801 e = expr_alloc_two(E_OR, e1, e2);
802 if (type == E_UNEQUAL)
803 e = expr_alloc_one(E_NOT, e);
804 return e;
805 case E_OR:
806 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
807 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
808 if (sym == &symbol_yes)
809 e = expr_alloc_two(E_OR, e1, e2);
810 if (sym == &symbol_no)
811 e = expr_alloc_two(E_AND, e1, e2);
812 if (type == E_UNEQUAL)
813 e = expr_alloc_one(E_NOT, e);
814 return e;
815 case E_NOT:
816 return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
817 case E_UNEQUAL:
818 case E_LTH:
819 case E_LEQ:
820 case E_GTH:
821 case E_GEQ:
822 case E_EQUAL:
823 if (type == E_EQUAL) {
824 if (sym == &symbol_yes)
825 return e;
826 if (sym == &symbol_mod)
827 return expr_alloc_symbol(&symbol_no);
828 if (sym == &symbol_no)
829 return expr_alloc_one(E_NOT, e);
830 } else {
831 if (sym == &symbol_yes)
832 return expr_alloc_one(E_NOT, e);
833 if (sym == &symbol_mod)
834 return expr_alloc_symbol(&symbol_yes);
835 if (sym == &symbol_no)
836 return e;
837 }
838 break;
839 case E_SYMBOL:
840 return expr_alloc_comp(type, e->left.sym, sym);
841 case E_RANGE:
842 case E_NONE:
843 /* panic */;
844 }
845 return NULL;
846}
847
848enum string_value_kind {
849 k_string,
850 k_signed,
851 k_unsigned,
852};
853
854union string_value {
855 unsigned long long u;
856 signed long long s;
857};
858
859static enum string_value_kind expr_parse_string(const char *str,
860 enum symbol_type type,
861 union string_value *val)
862{
863 char *tail;
864 enum string_value_kind kind;
865
866 errno = 0;
867 switch (type) {
868 case S_BOOLEAN:
869 case S_TRISTATE:
870 val->s = !strcmp(str, "n") ? 0 :
871 !strcmp(str, "m") ? 1 :
872 !strcmp(str, "y") ? 2 : -1;
873 return k_signed;
874 case S_INT:
875 val->s = strtoll(str, &tail, 10);
876 kind = k_signed;
877 break;
878 case S_HEX:
879 val->u = strtoull(str, &tail, 16);
880 kind = k_unsigned;
881 break;
882 default:
883 val->s = strtoll(str, &tail, 0);
884 kind = k_signed;
885 break;
886 }
887 return !errno && !*tail && tail > str && isxdigit(tail[-1])
888 ? kind : k_string;
889}
890
891static tristate __expr_calc_value(struct expr *e)
892{
893 tristate val1, val2;
894 const char *str1, *str2;
895 enum string_value_kind k1 = k_string, k2 = k_string;
896 union string_value lval = {}, rval = {};
897 int res;
898
899 switch (e->type) {
900 case E_SYMBOL:
901 sym_calc_value(e->left.sym);
902 return e->left.sym->curr.tri;
903 case E_AND:
904 val1 = expr_calc_value(e->left.expr);
905 val2 = expr_calc_value(e->right.expr);
906 return EXPR_AND(val1, val2);
907 case E_OR:
908 val1 = expr_calc_value(e->left.expr);
909 val2 = expr_calc_value(e->right.expr);
910 return EXPR_OR(val1, val2);
911 case E_NOT:
912 val1 = expr_calc_value(e->left.expr);
913 return EXPR_NOT(val1);
914 case E_EQUAL:
915 case E_GEQ:
916 case E_GTH:
917 case E_LEQ:
918 case E_LTH:
919 case E_UNEQUAL:
920 break;
921 default:
922 printf("expr_calc_value: %d?\n", e->type);
923 return no;
924 }
925
926 sym_calc_value(e->left.sym);
927 sym_calc_value(e->right.sym);
928 str1 = sym_get_string_value(e->left.sym);
929 str2 = sym_get_string_value(e->right.sym);
930
931 if (e->left.sym->type != S_STRING || e->right.sym->type != S_STRING) {
932 k1 = expr_parse_string(str1, e->left.sym->type, &lval);
933 k2 = expr_parse_string(str2, e->right.sym->type, &rval);
934 }
935
936 if (k1 == k_string || k2 == k_string)
937 res = strcmp(str1, str2);
938 else if (k1 == k_unsigned || k2 == k_unsigned)
939 res = (lval.u > rval.u) - (lval.u < rval.u);
940 else /* if (k1 == k_signed && k2 == k_signed) */
941 res = (lval.s > rval.s) - (lval.s < rval.s);
942
943 switch(e->type) {
944 case E_EQUAL:
945 return res ? no : yes;
946 case E_GEQ:
947 return res >= 0 ? yes : no;
948 case E_GTH:
949 return res > 0 ? yes : no;
950 case E_LEQ:
951 return res <= 0 ? yes : no;
952 case E_LTH:
953 return res < 0 ? yes : no;
954 case E_UNEQUAL:
955 return res ? yes : no;
956 default:
957 printf("expr_calc_value: relation %d?\n", e->type);
958 return no;
959 }
960}
961
962/**
963 * expr_calc_value - return the tristate value of the given expression
964 * @e: expression
965 * return: tristate value of the expression
966 */
967tristate expr_calc_value(struct expr *e)
968{
969 if (!e)
970 return yes;
971
972 if (!e->val_is_valid) {
973 e->val = __expr_calc_value(e);
974 e->val_is_valid = true;
975 }
976
977 return e->val;
978}
979
980/**
981 * expr_invalidate_all - invalidate all cached expression values
982 */
983void expr_invalidate_all(void)
984{
985 struct expr *e;
986
987 hash_for_each(expr_hashtable, e, node)
988 e->val_is_valid = false;
989}
990
991static int expr_compare_type(enum expr_type t1, enum expr_type t2)
992{
993 if (t1 == t2)
994 return 0;
995 switch (t1) {
996 case E_LEQ:
997 case E_LTH:
998 case E_GEQ:
999 case E_GTH:
1000 if (t2 == E_EQUAL || t2 == E_UNEQUAL)
1001 return 1;
1002 /* fallthrough */
1003 case E_EQUAL:
1004 case E_UNEQUAL:
1005 if (t2 == E_NOT)
1006 return 1;
1007 /* fallthrough */
1008 case E_NOT:
1009 if (t2 == E_AND)
1010 return 1;
1011 /* fallthrough */
1012 case E_AND:
1013 if (t2 == E_OR)
1014 return 1;
1015 /* fallthrough */
1016 default:
1017 break;
1018 }
1019 return 0;
1020}
1021
1022void expr_print(const struct expr *e,
1023 void (*fn)(void *, struct symbol *, const char *),
1024 void *data, int prevtoken)
1025{
1026 if (!e) {
1027 fn(data, NULL, "y");
1028 return;
1029 }
1030
1031 if (expr_compare_type(prevtoken, e->type) > 0)
1032 fn(data, NULL, "(");
1033 switch (e->type) {
1034 case E_SYMBOL:
1035 if (e->left.sym->name)
1036 fn(data, e->left.sym, e->left.sym->name);
1037 else
1038 fn(data, NULL, "<choice>");
1039 break;
1040 case E_NOT:
1041 fn(data, NULL, "!");
1042 expr_print(e->left.expr, fn, data, E_NOT);
1043 break;
1044 case E_EQUAL:
1045 if (e->left.sym->name)
1046 fn(data, e->left.sym, e->left.sym->name);
1047 else
1048 fn(data, NULL, "<choice>");
1049 fn(data, NULL, "=");
1050 fn(data, e->right.sym, e->right.sym->name);
1051 break;
1052 case E_LEQ:
1053 case E_LTH:
1054 if (e->left.sym->name)
1055 fn(data, e->left.sym, e->left.sym->name);
1056 else
1057 fn(data, NULL, "<choice>");
1058 fn(data, NULL, e->type == E_LEQ ? "<=" : "<");
1059 fn(data, e->right.sym, e->right.sym->name);
1060 break;
1061 case E_GEQ:
1062 case E_GTH:
1063 if (e->left.sym->name)
1064 fn(data, e->left.sym, e->left.sym->name);
1065 else
1066 fn(data, NULL, "<choice>");
1067 fn(data, NULL, e->type == E_GEQ ? ">=" : ">");
1068 fn(data, e->right.sym, e->right.sym->name);
1069 break;
1070 case E_UNEQUAL:
1071 if (e->left.sym->name)
1072 fn(data, e->left.sym, e->left.sym->name);
1073 else
1074 fn(data, NULL, "<choice>");
1075 fn(data, NULL, "!=");
1076 fn(data, e->right.sym, e->right.sym->name);
1077 break;
1078 case E_OR:
1079 expr_print(e->left.expr, fn, data, E_OR);
1080 fn(data, NULL, " || ");
1081 expr_print(e->right.expr, fn, data, E_OR);
1082 break;
1083 case E_AND:
1084 expr_print(e->left.expr, fn, data, E_AND);
1085 fn(data, NULL, " && ");
1086 expr_print(e->right.expr, fn, data, E_AND);
1087 break;
1088 case E_RANGE:
1089 fn(data, NULL, "[");
1090 fn(data, e->left.sym, e->left.sym->name);
1091 fn(data, NULL, " ");
1092 fn(data, e->right.sym, e->right.sym->name);
1093 fn(data, NULL, "]");
1094 break;
1095 default:
1096 {
1097 char buf[32];
1098 sprintf(buf, "<unknown type %d>", e->type);
1099 fn(data, NULL, buf);
1100 break;
1101 }
1102 }
1103 if (expr_compare_type(prevtoken, e->type) > 0)
1104 fn(data, NULL, ")");
1105}
1106
1107static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
1108{
1109 xfwrite(str, strlen(str), 1, data);
1110}
1111
1112void expr_fprint(struct expr *e, FILE *out)
1113{
1114 expr_print(e, expr_print_file_helper, out, E_NONE);
1115}
1116
1117static void expr_print_gstr_helper(void *data, struct symbol *sym, const char *str)
1118{
1119 struct gstr *gs = (struct gstr*)data;
1120 const char *sym_str = NULL;
1121
1122 if (sym)
1123 sym_str = sym_get_string_value(sym);
1124
1125 if (gs->max_width) {
1126 unsigned extra_length = strlen(str);
1127 const char *last_cr = strrchr(gs->s, '\n');
1128 unsigned last_line_length;
1129
1130 if (sym_str)
1131 extra_length += 4 + strlen(sym_str);
1132
1133 if (!last_cr)
1134 last_cr = gs->s;
1135
1136 last_line_length = strlen(gs->s) - (last_cr - gs->s);
1137
1138 if ((last_line_length + extra_length) > gs->max_width)
1139 str_append(gs, "\\\n");
1140 }
1141
1142 str_append(gs, str);
1143 if (sym && sym->type != S_UNKNOWN)
1144 str_printf(gs, " [=%s]", sym_str);
1145}
1146
1147void expr_gstr_print(const struct expr *e, struct gstr *gs)
1148{
1149 expr_print(e, expr_print_gstr_helper, gs, E_NONE);
1150}
1151
1152/*
1153 * Transform the top level "||" tokens into newlines and prepend each
1154 * line with a minus. This makes expressions much easier to read.
1155 * Suitable for reverse dependency expressions.
1156 */
1157static void expr_print_revdep(struct expr *e,
1158 void (*fn)(void *, struct symbol *, const char *),
1159 void *data, tristate pr_type, const char **title)
1160{
1161 if (e->type == E_OR) {
1162 expr_print_revdep(e->left.expr, fn, data, pr_type, title);
1163 expr_print_revdep(e->right.expr, fn, data, pr_type, title);
1164 } else if (expr_calc_value(e) == pr_type) {
1165 if (*title) {
1166 fn(data, NULL, *title);
1167 *title = NULL;
1168 }
1169
1170 fn(data, NULL, " - ");
1171 expr_print(e, fn, data, E_NONE);
1172 fn(data, NULL, "\n");
1173 }
1174}
1175
1176void expr_gstr_print_revdep(struct expr *e, struct gstr *gs,
1177 tristate pr_type, const char *title)
1178{
1179 expr_print_revdep(e, expr_print_gstr_helper, gs, pr_type, &title);
1180}