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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
14static int expr_eq(struct expr *e1, struct expr *e2);
15static struct expr *expr_eliminate_yn(struct expr *e);
16
17struct expr *expr_alloc_symbol(struct symbol *sym)
18{
19 struct expr *e = xcalloc(1, sizeof(*e));
20 e->type = E_SYMBOL;
21 e->left.sym = sym;
22 return e;
23}
24
25struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
26{
27 struct expr *e = xcalloc(1, sizeof(*e));
28 e->type = type;
29 e->left.expr = ce;
30 return e;
31}
32
33struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
34{
35 struct expr *e = xcalloc(1, sizeof(*e));
36 e->type = type;
37 e->left.expr = e1;
38 e->right.expr = e2;
39 return e;
40}
41
42struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
43{
44 struct expr *e = xcalloc(1, sizeof(*e));
45 e->type = type;
46 e->left.sym = s1;
47 e->right.sym = s2;
48 return e;
49}
50
51struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
52{
53 if (!e1)
54 return e2;
55 return e2 ? expr_alloc_two(E_AND, e1, e2) : e1;
56}
57
58struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
59{
60 if (!e1)
61 return e2;
62 return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
63}
64
65struct expr *expr_copy(const struct expr *org)
66{
67 struct expr *e;
68
69 if (!org)
70 return NULL;
71
72 e = xmalloc(sizeof(*org));
73 memcpy(e, org, sizeof(*org));
74 switch (org->type) {
75 case E_SYMBOL:
76 e->left = org->left;
77 break;
78 case E_NOT:
79 e->left.expr = expr_copy(org->left.expr);
80 break;
81 case E_EQUAL:
82 case E_GEQ:
83 case E_GTH:
84 case E_LEQ:
85 case E_LTH:
86 case E_UNEQUAL:
87 e->left.sym = org->left.sym;
88 e->right.sym = org->right.sym;
89 break;
90 case E_AND:
91 case E_OR:
92 case E_LIST:
93 e->left.expr = expr_copy(org->left.expr);
94 e->right.expr = expr_copy(org->right.expr);
95 break;
96 default:
97 printf("can't copy type %d\n", e->type);
98 free(e);
99 e = NULL;
100 break;
101 }
102
103 return e;
104}
105
106void expr_free(struct expr *e)
107{
108 if (!e)
109 return;
110
111 switch (e->type) {
112 case E_SYMBOL:
113 break;
114 case E_NOT:
115 expr_free(e->left.expr);
116 return;
117 case E_EQUAL:
118 case E_GEQ:
119 case E_GTH:
120 case E_LEQ:
121 case E_LTH:
122 case E_UNEQUAL:
123 break;
124 case E_OR:
125 case E_AND:
126 expr_free(e->left.expr);
127 expr_free(e->right.expr);
128 break;
129 default:
130 printf("how to free type %d?\n", e->type);
131 break;
132 }
133 free(e);
134}
135
136static int trans_count;
137
138#define e1 (*ep1)
139#define e2 (*ep2)
140
141static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
142{
143 if (e1->type == type) {
144 __expr_eliminate_eq(type, &e1->left.expr, &e2);
145 __expr_eliminate_eq(type, &e1->right.expr, &e2);
146 return;
147 }
148 if (e2->type == type) {
149 __expr_eliminate_eq(type, &e1, &e2->left.expr);
150 __expr_eliminate_eq(type, &e1, &e2->right.expr);
151 return;
152 }
153 if (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
154 e1->left.sym == e2->left.sym &&
155 (e1->left.sym == &symbol_yes || e1->left.sym == &symbol_no))
156 return;
157 if (!expr_eq(e1, e2))
158 return;
159 trans_count++;
160 expr_free(e1); expr_free(e2);
161 switch (type) {
162 case E_OR:
163 e1 = expr_alloc_symbol(&symbol_no);
164 e2 = expr_alloc_symbol(&symbol_no);
165 break;
166 case E_AND:
167 e1 = expr_alloc_symbol(&symbol_yes);
168 e2 = expr_alloc_symbol(&symbol_yes);
169 break;
170 default:
171 ;
172 }
173}
174
175void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
176{
177 if (!e1 || !e2)
178 return;
179 switch (e1->type) {
180 case E_OR:
181 case E_AND:
182 __expr_eliminate_eq(e1->type, ep1, ep2);
183 default:
184 ;
185 }
186 if (e1->type != e2->type) switch (e2->type) {
187 case E_OR:
188 case E_AND:
189 __expr_eliminate_eq(e2->type, ep1, ep2);
190 default:
191 ;
192 }
193 e1 = expr_eliminate_yn(e1);
194 e2 = expr_eliminate_yn(e2);
195}
196
197#undef e1
198#undef e2
199
200static int expr_eq(struct expr *e1, struct expr *e2)
201{
202 int res, old_count;
203
204 if (e1->type != e2->type)
205 return 0;
206 switch (e1->type) {
207 case E_EQUAL:
208 case E_GEQ:
209 case E_GTH:
210 case E_LEQ:
211 case E_LTH:
212 case E_UNEQUAL:
213 return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
214 case E_SYMBOL:
215 return e1->left.sym == e2->left.sym;
216 case E_NOT:
217 return expr_eq(e1->left.expr, e2->left.expr);
218 case E_AND:
219 case E_OR:
220 e1 = expr_copy(e1);
221 e2 = expr_copy(e2);
222 old_count = trans_count;
223 expr_eliminate_eq(&e1, &e2);
224 res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
225 e1->left.sym == e2->left.sym);
226 expr_free(e1);
227 expr_free(e2);
228 trans_count = old_count;
229 return res;
230 case E_LIST:
231 case E_RANGE:
232 case E_NONE:
233 /* panic */;
234 }
235
236 if (DEBUG_EXPR) {
237 expr_fprint(e1, stdout);
238 printf(" = ");
239 expr_fprint(e2, stdout);
240 printf(" ?\n");
241 }
242
243 return 0;
244}
245
246static struct expr *expr_eliminate_yn(struct expr *e)
247{
248 struct expr *tmp;
249
250 if (e) switch (e->type) {
251 case E_AND:
252 e->left.expr = expr_eliminate_yn(e->left.expr);
253 e->right.expr = expr_eliminate_yn(e->right.expr);
254 if (e->left.expr->type == E_SYMBOL) {
255 if (e->left.expr->left.sym == &symbol_no) {
256 expr_free(e->left.expr);
257 expr_free(e->right.expr);
258 e->type = E_SYMBOL;
259 e->left.sym = &symbol_no;
260 e->right.expr = NULL;
261 return e;
262 } else if (e->left.expr->left.sym == &symbol_yes) {
263 free(e->left.expr);
264 tmp = e->right.expr;
265 *e = *(e->right.expr);
266 free(tmp);
267 return e;
268 }
269 }
270 if (e->right.expr->type == E_SYMBOL) {
271 if (e->right.expr->left.sym == &symbol_no) {
272 expr_free(e->left.expr);
273 expr_free(e->right.expr);
274 e->type = E_SYMBOL;
275 e->left.sym = &symbol_no;
276 e->right.expr = NULL;
277 return e;
278 } else if (e->right.expr->left.sym == &symbol_yes) {
279 free(e->right.expr);
280 tmp = e->left.expr;
281 *e = *(e->left.expr);
282 free(tmp);
283 return e;
284 }
285 }
286 break;
287 case E_OR:
288 e->left.expr = expr_eliminate_yn(e->left.expr);
289 e->right.expr = expr_eliminate_yn(e->right.expr);
290 if (e->left.expr->type == E_SYMBOL) {
291 if (e->left.expr->left.sym == &symbol_no) {
292 free(e->left.expr);
293 tmp = e->right.expr;
294 *e = *(e->right.expr);
295 free(tmp);
296 return e;
297 } else if (e->left.expr->left.sym == &symbol_yes) {
298 expr_free(e->left.expr);
299 expr_free(e->right.expr);
300 e->type = E_SYMBOL;
301 e->left.sym = &symbol_yes;
302 e->right.expr = NULL;
303 return e;
304 }
305 }
306 if (e->right.expr->type == E_SYMBOL) {
307 if (e->right.expr->left.sym == &symbol_no) {
308 free(e->right.expr);
309 tmp = e->left.expr;
310 *e = *(e->left.expr);
311 free(tmp);
312 return e;
313 } else if (e->right.expr->left.sym == &symbol_yes) {
314 expr_free(e->left.expr);
315 expr_free(e->right.expr);
316 e->type = E_SYMBOL;
317 e->left.sym = &symbol_yes;
318 e->right.expr = NULL;
319 return e;
320 }
321 }
322 break;
323 default:
324 ;
325 }
326 return e;
327}
328
329/*
330 * bool FOO!=n => FOO
331 */
332struct expr *expr_trans_bool(struct expr *e)
333{
334 if (!e)
335 return NULL;
336 switch (e->type) {
337 case E_AND:
338 case E_OR:
339 case E_NOT:
340 e->left.expr = expr_trans_bool(e->left.expr);
341 e->right.expr = expr_trans_bool(e->right.expr);
342 break;
343 case E_UNEQUAL:
344 // FOO!=n -> FOO
345 if (e->left.sym->type == S_TRISTATE) {
346 if (e->right.sym == &symbol_no) {
347 e->type = E_SYMBOL;
348 e->right.sym = NULL;
349 }
350 }
351 break;
352 default:
353 ;
354 }
355 return e;
356}
357
358/*
359 * e1 || e2 -> ?
360 */
361static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
362{
363 struct expr *tmp;
364 struct symbol *sym1, *sym2;
365
366 if (expr_eq(e1, e2))
367 return expr_copy(e1);
368 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
369 return NULL;
370 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
371 return NULL;
372 if (e1->type == E_NOT) {
373 tmp = e1->left.expr;
374 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
375 return NULL;
376 sym1 = tmp->left.sym;
377 } else
378 sym1 = e1->left.sym;
379 if (e2->type == E_NOT) {
380 if (e2->left.expr->type != E_SYMBOL)
381 return NULL;
382 sym2 = e2->left.expr->left.sym;
383 } else
384 sym2 = e2->left.sym;
385 if (sym1 != sym2)
386 return NULL;
387 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
388 return NULL;
389 if (sym1->type == S_TRISTATE) {
390 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
391 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
392 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
393 // (a='y') || (a='m') -> (a!='n')
394 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
395 }
396 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
397 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
398 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
399 // (a='y') || (a='n') -> (a!='m')
400 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
401 }
402 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
403 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
404 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
405 // (a='m') || (a='n') -> (a!='y')
406 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
407 }
408 }
409 if (sym1->type == S_BOOLEAN && sym1 == sym2) {
410 if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
411 (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
412 return expr_alloc_symbol(&symbol_yes);
413 }
414
415 if (DEBUG_EXPR) {
416 printf("optimize (");
417 expr_fprint(e1, stdout);
418 printf(") || (");
419 expr_fprint(e2, stdout);
420 printf(")?\n");
421 }
422 return NULL;
423}
424
425static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
426{
427 struct expr *tmp;
428 struct symbol *sym1, *sym2;
429
430 if (expr_eq(e1, e2))
431 return expr_copy(e1);
432 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
433 return NULL;
434 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
435 return NULL;
436 if (e1->type == E_NOT) {
437 tmp = e1->left.expr;
438 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
439 return NULL;
440 sym1 = tmp->left.sym;
441 } else
442 sym1 = e1->left.sym;
443 if (e2->type == E_NOT) {
444 if (e2->left.expr->type != E_SYMBOL)
445 return NULL;
446 sym2 = e2->left.expr->left.sym;
447 } else
448 sym2 = e2->left.sym;
449 if (sym1 != sym2)
450 return NULL;
451 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
452 return NULL;
453
454 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
455 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
456 // (a) && (a='y') -> (a='y')
457 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
458
459 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
460 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
461 // (a) && (a!='n') -> (a)
462 return expr_alloc_symbol(sym1);
463
464 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
465 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
466 // (a) && (a!='m') -> (a='y')
467 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
468
469 if (sym1->type == S_TRISTATE) {
470 if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
471 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
472 sym2 = e1->right.sym;
473 if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
474 return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
475 : expr_alloc_symbol(&symbol_no);
476 }
477 if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
478 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
479 sym2 = e2->right.sym;
480 if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
481 return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
482 : expr_alloc_symbol(&symbol_no);
483 }
484 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
485 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
486 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
487 // (a!='y') && (a!='n') -> (a='m')
488 return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
489
490 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
491 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
492 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
493 // (a!='y') && (a!='m') -> (a='n')
494 return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
495
496 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
497 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
498 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
499 // (a!='m') && (a!='n') -> (a='m')
500 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
501
502 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
503 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
504 (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
505 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
506 return NULL;
507 }
508
509 if (DEBUG_EXPR) {
510 printf("optimize (");
511 expr_fprint(e1, stdout);
512 printf(") && (");
513 expr_fprint(e2, stdout);
514 printf(")?\n");
515 }
516 return NULL;
517}
518
519static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
520{
521#define e1 (*ep1)
522#define e2 (*ep2)
523 struct expr *tmp;
524
525 if (e1->type == type) {
526 expr_eliminate_dups1(type, &e1->left.expr, &e2);
527 expr_eliminate_dups1(type, &e1->right.expr, &e2);
528 return;
529 }
530 if (e2->type == type) {
531 expr_eliminate_dups1(type, &e1, &e2->left.expr);
532 expr_eliminate_dups1(type, &e1, &e2->right.expr);
533 return;
534 }
535 if (e1 == e2)
536 return;
537
538 switch (e1->type) {
539 case E_OR: case E_AND:
540 expr_eliminate_dups1(e1->type, &e1, &e1);
541 default:
542 ;
543 }
544
545 switch (type) {
546 case E_OR:
547 tmp = expr_join_or(e1, e2);
548 if (tmp) {
549 expr_free(e1); expr_free(e2);
550 e1 = expr_alloc_symbol(&symbol_no);
551 e2 = tmp;
552 trans_count++;
553 }
554 break;
555 case E_AND:
556 tmp = expr_join_and(e1, e2);
557 if (tmp) {
558 expr_free(e1); expr_free(e2);
559 e1 = expr_alloc_symbol(&symbol_yes);
560 e2 = tmp;
561 trans_count++;
562 }
563 break;
564 default:
565 ;
566 }
567#undef e1
568#undef e2
569}
570
571struct expr *expr_eliminate_dups(struct expr *e)
572{
573 int oldcount;
574 if (!e)
575 return e;
576
577 oldcount = trans_count;
578 while (1) {
579 trans_count = 0;
580 switch (e->type) {
581 case E_OR: case E_AND:
582 expr_eliminate_dups1(e->type, &e, &e);
583 default:
584 ;
585 }
586 if (!trans_count)
587 break;
588 e = expr_eliminate_yn(e);
589 }
590 trans_count = oldcount;
591 return e;
592}
593
594struct expr *expr_transform(struct expr *e)
595{
596 struct expr *tmp;
597
598 if (!e)
599 return NULL;
600 switch (e->type) {
601 case E_EQUAL:
602 case E_GEQ:
603 case E_GTH:
604 case E_LEQ:
605 case E_LTH:
606 case E_UNEQUAL:
607 case E_SYMBOL:
608 case E_LIST:
609 break;
610 default:
611 e->left.expr = expr_transform(e->left.expr);
612 e->right.expr = expr_transform(e->right.expr);
613 }
614
615 switch (e->type) {
616 case E_EQUAL:
617 if (e->left.sym->type != S_BOOLEAN)
618 break;
619 if (e->right.sym == &symbol_no) {
620 e->type = E_NOT;
621 e->left.expr = expr_alloc_symbol(e->left.sym);
622 e->right.sym = NULL;
623 break;
624 }
625 if (e->right.sym == &symbol_mod) {
626 printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
627 e->type = E_SYMBOL;
628 e->left.sym = &symbol_no;
629 e->right.sym = NULL;
630 break;
631 }
632 if (e->right.sym == &symbol_yes) {
633 e->type = E_SYMBOL;
634 e->right.sym = NULL;
635 break;
636 }
637 break;
638 case E_UNEQUAL:
639 if (e->left.sym->type != S_BOOLEAN)
640 break;
641 if (e->right.sym == &symbol_no) {
642 e->type = E_SYMBOL;
643 e->right.sym = NULL;
644 break;
645 }
646 if (e->right.sym == &symbol_mod) {
647 printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
648 e->type = E_SYMBOL;
649 e->left.sym = &symbol_yes;
650 e->right.sym = NULL;
651 break;
652 }
653 if (e->right.sym == &symbol_yes) {
654 e->type = E_NOT;
655 e->left.expr = expr_alloc_symbol(e->left.sym);
656 e->right.sym = NULL;
657 break;
658 }
659 break;
660 case E_NOT:
661 switch (e->left.expr->type) {
662 case E_NOT:
663 // !!a -> a
664 tmp = e->left.expr->left.expr;
665 free(e->left.expr);
666 free(e);
667 e = tmp;
668 e = expr_transform(e);
669 break;
670 case E_EQUAL:
671 case E_UNEQUAL:
672 // !a='x' -> a!='x'
673 tmp = e->left.expr;
674 free(e);
675 e = tmp;
676 e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
677 break;
678 case E_LEQ:
679 case E_GEQ:
680 // !a<='x' -> a>'x'
681 tmp = e->left.expr;
682 free(e);
683 e = tmp;
684 e->type = e->type == E_LEQ ? E_GTH : E_LTH;
685 break;
686 case E_LTH:
687 case E_GTH:
688 // !a<'x' -> a>='x'
689 tmp = e->left.expr;
690 free(e);
691 e = tmp;
692 e->type = e->type == E_LTH ? E_GEQ : E_LEQ;
693 break;
694 case E_OR:
695 // !(a || b) -> !a && !b
696 tmp = e->left.expr;
697 e->type = E_AND;
698 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
699 tmp->type = E_NOT;
700 tmp->right.expr = NULL;
701 e = expr_transform(e);
702 break;
703 case E_AND:
704 // !(a && b) -> !a || !b
705 tmp = e->left.expr;
706 e->type = E_OR;
707 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
708 tmp->type = E_NOT;
709 tmp->right.expr = NULL;
710 e = expr_transform(e);
711 break;
712 case E_SYMBOL:
713 if (e->left.expr->left.sym == &symbol_yes) {
714 // !'y' -> 'n'
715 tmp = e->left.expr;
716 free(e);
717 e = tmp;
718 e->type = E_SYMBOL;
719 e->left.sym = &symbol_no;
720 break;
721 }
722 if (e->left.expr->left.sym == &symbol_mod) {
723 // !'m' -> 'm'
724 tmp = e->left.expr;
725 free(e);
726 e = tmp;
727 e->type = E_SYMBOL;
728 e->left.sym = &symbol_mod;
729 break;
730 }
731 if (e->left.expr->left.sym == &symbol_no) {
732 // !'n' -> 'y'
733 tmp = e->left.expr;
734 free(e);
735 e = tmp;
736 e->type = E_SYMBOL;
737 e->left.sym = &symbol_yes;
738 break;
739 }
740 break;
741 default:
742 ;
743 }
744 break;
745 default:
746 ;
747 }
748 return e;
749}
750
751int expr_contains_symbol(struct expr *dep, struct symbol *sym)
752{
753 if (!dep)
754 return 0;
755
756 switch (dep->type) {
757 case E_AND:
758 case E_OR:
759 return expr_contains_symbol(dep->left.expr, sym) ||
760 expr_contains_symbol(dep->right.expr, sym);
761 case E_SYMBOL:
762 return dep->left.sym == sym;
763 case E_EQUAL:
764 case E_GEQ:
765 case E_GTH:
766 case E_LEQ:
767 case E_LTH:
768 case E_UNEQUAL:
769 return dep->left.sym == sym ||
770 dep->right.sym == sym;
771 case E_NOT:
772 return expr_contains_symbol(dep->left.expr, sym);
773 default:
774 ;
775 }
776 return 0;
777}
778
779bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
780{
781 if (!dep)
782 return false;
783
784 switch (dep->type) {
785 case E_AND:
786 return expr_depends_symbol(dep->left.expr, sym) ||
787 expr_depends_symbol(dep->right.expr, sym);
788 case E_SYMBOL:
789 return dep->left.sym == sym;
790 case E_EQUAL:
791 if (dep->left.sym == sym) {
792 if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
793 return true;
794 }
795 break;
796 case E_UNEQUAL:
797 if (dep->left.sym == sym) {
798 if (dep->right.sym == &symbol_no)
799 return true;
800 }
801 break;
802 default:
803 ;
804 }
805 return false;
806}
807
808struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
809{
810 struct expr *e1, *e2;
811
812 if (!e) {
813 e = expr_alloc_symbol(sym);
814 if (type == E_UNEQUAL)
815 e = expr_alloc_one(E_NOT, e);
816 return e;
817 }
818 switch (e->type) {
819 case E_AND:
820 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
821 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
822 if (sym == &symbol_yes)
823 e = expr_alloc_two(E_AND, e1, e2);
824 if (sym == &symbol_no)
825 e = expr_alloc_two(E_OR, e1, e2);
826 if (type == E_UNEQUAL)
827 e = expr_alloc_one(E_NOT, e);
828 return e;
829 case E_OR:
830 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
831 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
832 if (sym == &symbol_yes)
833 e = expr_alloc_two(E_OR, e1, e2);
834 if (sym == &symbol_no)
835 e = expr_alloc_two(E_AND, e1, e2);
836 if (type == E_UNEQUAL)
837 e = expr_alloc_one(E_NOT, e);
838 return e;
839 case E_NOT:
840 return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
841 case E_UNEQUAL:
842 case E_LTH:
843 case E_LEQ:
844 case E_GTH:
845 case E_GEQ:
846 case E_EQUAL:
847 if (type == E_EQUAL) {
848 if (sym == &symbol_yes)
849 return expr_copy(e);
850 if (sym == &symbol_mod)
851 return expr_alloc_symbol(&symbol_no);
852 if (sym == &symbol_no)
853 return expr_alloc_one(E_NOT, expr_copy(e));
854 } else {
855 if (sym == &symbol_yes)
856 return expr_alloc_one(E_NOT, expr_copy(e));
857 if (sym == &symbol_mod)
858 return expr_alloc_symbol(&symbol_yes);
859 if (sym == &symbol_no)
860 return expr_copy(e);
861 }
862 break;
863 case E_SYMBOL:
864 return expr_alloc_comp(type, e->left.sym, sym);
865 case E_LIST:
866 case E_RANGE:
867 case E_NONE:
868 /* panic */;
869 }
870 return NULL;
871}
872
873enum string_value_kind {
874 k_string,
875 k_signed,
876 k_unsigned,
877 k_invalid
878};
879
880union string_value {
881 unsigned long long u;
882 signed long long s;
883};
884
885static enum string_value_kind expr_parse_string(const char *str,
886 enum symbol_type type,
887 union string_value *val)
888{
889 char *tail;
890 enum string_value_kind kind;
891
892 errno = 0;
893 switch (type) {
894 case S_BOOLEAN:
895 case S_TRISTATE:
896 return k_string;
897 case S_INT:
898 val->s = strtoll(str, &tail, 10);
899 kind = k_signed;
900 break;
901 case S_HEX:
902 val->u = strtoull(str, &tail, 16);
903 kind = k_unsigned;
904 break;
905 case S_STRING:
906 case S_UNKNOWN:
907 val->s = strtoll(str, &tail, 0);
908 kind = k_signed;
909 break;
910 default:
911 return k_invalid;
912 }
913 return !errno && !*tail && tail > str && isxdigit(tail[-1])
914 ? kind : k_string;
915}
916
917tristate expr_calc_value(struct expr *e)
918{
919 tristate val1, val2;
920 const char *str1, *str2;
921 enum string_value_kind k1 = k_string, k2 = k_string;
922 union string_value lval = {}, rval = {};
923 int res;
924
925 if (!e)
926 return yes;
927
928 switch (e->type) {
929 case E_SYMBOL:
930 sym_calc_value(e->left.sym);
931 return e->left.sym->curr.tri;
932 case E_AND:
933 val1 = expr_calc_value(e->left.expr);
934 val2 = expr_calc_value(e->right.expr);
935 return EXPR_AND(val1, val2);
936 case E_OR:
937 val1 = expr_calc_value(e->left.expr);
938 val2 = expr_calc_value(e->right.expr);
939 return EXPR_OR(val1, val2);
940 case E_NOT:
941 val1 = expr_calc_value(e->left.expr);
942 return EXPR_NOT(val1);
943 case E_EQUAL:
944 case E_GEQ:
945 case E_GTH:
946 case E_LEQ:
947 case E_LTH:
948 case E_UNEQUAL:
949 break;
950 default:
951 printf("expr_calc_value: %d?\n", e->type);
952 return no;
953 }
954
955 sym_calc_value(e->left.sym);
956 sym_calc_value(e->right.sym);
957 str1 = sym_get_string_value(e->left.sym);
958 str2 = sym_get_string_value(e->right.sym);
959
960 if (e->left.sym->type != S_STRING || e->right.sym->type != S_STRING) {
961 k1 = expr_parse_string(str1, e->left.sym->type, &lval);
962 k2 = expr_parse_string(str2, e->right.sym->type, &rval);
963 }
964
965 if (k1 == k_string || k2 == k_string)
966 res = strcmp(str1, str2);
967 else if (k1 == k_invalid || k2 == k_invalid) {
968 if (e->type != E_EQUAL && e->type != E_UNEQUAL) {
969 printf("Cannot compare \"%s\" and \"%s\"\n", str1, str2);
970 return no;
971 }
972 res = strcmp(str1, str2);
973 } else if (k1 == k_unsigned || k2 == k_unsigned)
974 res = (lval.u > rval.u) - (lval.u < rval.u);
975 else /* if (k1 == k_signed && k2 == k_signed) */
976 res = (lval.s > rval.s) - (lval.s < rval.s);
977
978 switch(e->type) {
979 case E_EQUAL:
980 return res ? no : yes;
981 case E_GEQ:
982 return res >= 0 ? yes : no;
983 case E_GTH:
984 return res > 0 ? yes : no;
985 case E_LEQ:
986 return res <= 0 ? yes : no;
987 case E_LTH:
988 return res < 0 ? yes : no;
989 case E_UNEQUAL:
990 return res ? yes : no;
991 default:
992 printf("expr_calc_value: relation %d?\n", e->type);
993 return no;
994 }
995}
996
997static int expr_compare_type(enum expr_type t1, enum expr_type t2)
998{
999 if (t1 == t2)
1000 return 0;
1001 switch (t1) {
1002 case E_LEQ:
1003 case E_LTH:
1004 case E_GEQ:
1005 case E_GTH:
1006 if (t2 == E_EQUAL || t2 == E_UNEQUAL)
1007 return 1;
1008 case E_EQUAL:
1009 case E_UNEQUAL:
1010 if (t2 == E_NOT)
1011 return 1;
1012 case E_NOT:
1013 if (t2 == E_AND)
1014 return 1;
1015 case E_AND:
1016 if (t2 == E_OR)
1017 return 1;
1018 case E_OR:
1019 if (t2 == E_LIST)
1020 return 1;
1021 case E_LIST:
1022 if (t2 == 0)
1023 return 1;
1024 default:
1025 return -1;
1026 }
1027 printf("[%dgt%d?]", t1, t2);
1028 return 0;
1029}
1030
1031static inline struct expr *
1032expr_get_leftmost_symbol(const struct expr *e)
1033{
1034
1035 if (e == NULL)
1036 return NULL;
1037
1038 while (e->type != E_SYMBOL)
1039 e = e->left.expr;
1040
1041 return expr_copy(e);
1042}
1043
1044/*
1045 * Given expression `e1' and `e2', returns the leaf of the longest
1046 * sub-expression of `e1' not containing 'e2.
1047 */
1048struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2)
1049{
1050 struct expr *ret;
1051
1052 switch (e1->type) {
1053 case E_OR:
1054 return expr_alloc_and(
1055 expr_simplify_unmet_dep(e1->left.expr, e2),
1056 expr_simplify_unmet_dep(e1->right.expr, e2));
1057 case E_AND: {
1058 struct expr *e;
1059 e = expr_alloc_and(expr_copy(e1), expr_copy(e2));
1060 e = expr_eliminate_dups(e);
1061 ret = (!expr_eq(e, e1)) ? e1 : NULL;
1062 expr_free(e);
1063 break;
1064 }
1065 default:
1066 ret = e1;
1067 break;
1068 }
1069
1070 return expr_get_leftmost_symbol(ret);
1071}
1072
1073void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken)
1074{
1075 if (!e) {
1076 fn(data, NULL, "y");
1077 return;
1078 }
1079
1080 if (expr_compare_type(prevtoken, e->type) > 0)
1081 fn(data, NULL, "(");
1082 switch (e->type) {
1083 case E_SYMBOL:
1084 if (e->left.sym->name)
1085 fn(data, e->left.sym, e->left.sym->name);
1086 else
1087 fn(data, NULL, "<choice>");
1088 break;
1089 case E_NOT:
1090 fn(data, NULL, "!");
1091 expr_print(e->left.expr, fn, data, E_NOT);
1092 break;
1093 case E_EQUAL:
1094 if (e->left.sym->name)
1095 fn(data, e->left.sym, e->left.sym->name);
1096 else
1097 fn(data, NULL, "<choice>");
1098 fn(data, NULL, "=");
1099 fn(data, e->right.sym, e->right.sym->name);
1100 break;
1101 case E_LEQ:
1102 case E_LTH:
1103 if (e->left.sym->name)
1104 fn(data, e->left.sym, e->left.sym->name);
1105 else
1106 fn(data, NULL, "<choice>");
1107 fn(data, NULL, e->type == E_LEQ ? "<=" : "<");
1108 fn(data, e->right.sym, e->right.sym->name);
1109 break;
1110 case E_GEQ:
1111 case E_GTH:
1112 if (e->left.sym->name)
1113 fn(data, e->left.sym, e->left.sym->name);
1114 else
1115 fn(data, NULL, "<choice>");
1116 fn(data, NULL, e->type == E_GEQ ? ">=" : ">");
1117 fn(data, e->right.sym, e->right.sym->name);
1118 break;
1119 case E_UNEQUAL:
1120 if (e->left.sym->name)
1121 fn(data, e->left.sym, e->left.sym->name);
1122 else
1123 fn(data, NULL, "<choice>");
1124 fn(data, NULL, "!=");
1125 fn(data, e->right.sym, e->right.sym->name);
1126 break;
1127 case E_OR:
1128 expr_print(e->left.expr, fn, data, E_OR);
1129 fn(data, NULL, " || ");
1130 expr_print(e->right.expr, fn, data, E_OR);
1131 break;
1132 case E_AND:
1133 expr_print(e->left.expr, fn, data, E_AND);
1134 fn(data, NULL, " && ");
1135 expr_print(e->right.expr, fn, data, E_AND);
1136 break;
1137 case E_LIST:
1138 fn(data, e->right.sym, e->right.sym->name);
1139 if (e->left.expr) {
1140 fn(data, NULL, " ^ ");
1141 expr_print(e->left.expr, fn, data, E_LIST);
1142 }
1143 break;
1144 case E_RANGE:
1145 fn(data, NULL, "[");
1146 fn(data, e->left.sym, e->left.sym->name);
1147 fn(data, NULL, " ");
1148 fn(data, e->right.sym, e->right.sym->name);
1149 fn(data, NULL, "]");
1150 break;
1151 default:
1152 {
1153 char buf[32];
1154 sprintf(buf, "<unknown type %d>", e->type);
1155 fn(data, NULL, buf);
1156 break;
1157 }
1158 }
1159 if (expr_compare_type(prevtoken, e->type) > 0)
1160 fn(data, NULL, ")");
1161}
1162
1163static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
1164{
1165 xfwrite(str, strlen(str), 1, data);
1166}
1167
1168void expr_fprint(struct expr *e, FILE *out)
1169{
1170 expr_print(e, expr_print_file_helper, out, E_NONE);
1171}
1172
1173static void expr_print_gstr_helper(void *data, struct symbol *sym, const char *str)
1174{
1175 struct gstr *gs = (struct gstr*)data;
1176 const char *sym_str = NULL;
1177
1178 if (sym)
1179 sym_str = sym_get_string_value(sym);
1180
1181 if (gs->max_width) {
1182 unsigned extra_length = strlen(str);
1183 const char *last_cr = strrchr(gs->s, '\n');
1184 unsigned last_line_length;
1185
1186 if (sym_str)
1187 extra_length += 4 + strlen(sym_str);
1188
1189 if (!last_cr)
1190 last_cr = gs->s;
1191
1192 last_line_length = strlen(gs->s) - (last_cr - gs->s);
1193
1194 if ((last_line_length + extra_length) > gs->max_width)
1195 str_append(gs, "\\\n");
1196 }
1197
1198 str_append(gs, str);
1199 if (sym && sym->type != S_UNKNOWN)
1200 str_printf(gs, " [=%s]", sym_str);
1201}
1202
1203void expr_gstr_print(struct expr *e, struct gstr *gs)
1204{
1205 expr_print(e, expr_print_gstr_helper, gs, E_NONE);
1206}
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}