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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 "lkc.h"
13
14#define DEBUG_EXPR 0
15
16static struct expr *expr_eliminate_yn(struct expr *e);
17
18struct expr *expr_alloc_symbol(struct symbol *sym)
19{
20 struct expr *e = xcalloc(1, sizeof(*e));
21 e->type = E_SYMBOL;
22 e->left.sym = sym;
23 return e;
24}
25
26struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
27{
28 struct expr *e = xcalloc(1, sizeof(*e));
29 e->type = type;
30 e->left.expr = ce;
31 return e;
32}
33
34struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
35{
36 struct expr *e = xcalloc(1, sizeof(*e));
37 e->type = type;
38 e->left.expr = e1;
39 e->right.expr = e2;
40 return e;
41}
42
43struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
44{
45 struct expr *e = xcalloc(1, sizeof(*e));
46 e->type = type;
47 e->left.sym = s1;
48 e->right.sym = s2;
49 return e;
50}
51
52struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
53{
54 if (!e1)
55 return e2;
56 return e2 ? expr_alloc_two(E_AND, e1, e2) : e1;
57}
58
59struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
60{
61 if (!e1)
62 return e2;
63 return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
64}
65
66struct expr *expr_copy(const struct expr *org)
67{
68 struct expr *e;
69
70 if (!org)
71 return NULL;
72
73 e = xmalloc(sizeof(*org));
74 memcpy(e, org, sizeof(*org));
75 switch (org->type) {
76 case E_SYMBOL:
77 e->left = org->left;
78 break;
79 case E_NOT:
80 e->left.expr = expr_copy(org->left.expr);
81 break;
82 case E_EQUAL:
83 case E_GEQ:
84 case E_GTH:
85 case E_LEQ:
86 case E_LTH:
87 case E_UNEQUAL:
88 e->left.sym = org->left.sym;
89 e->right.sym = org->right.sym;
90 break;
91 case E_AND:
92 case E_OR:
93 case E_LIST:
94 e->left.expr = expr_copy(org->left.expr);
95 e->right.expr = expr_copy(org->right.expr);
96 break;
97 default:
98 fprintf(stderr, "can't copy type %d\n", e->type);
99 free(e);
100 e = NULL;
101 break;
102 }
103
104 return e;
105}
106
107void expr_free(struct expr *e)
108{
109 if (!e)
110 return;
111
112 switch (e->type) {
113 case E_SYMBOL:
114 break;
115 case E_NOT:
116 expr_free(e->left.expr);
117 break;
118 case E_EQUAL:
119 case E_GEQ:
120 case E_GTH:
121 case E_LEQ:
122 case E_LTH:
123 case E_UNEQUAL:
124 break;
125 case E_OR:
126 case E_AND:
127 expr_free(e->left.expr);
128 expr_free(e->right.expr);
129 break;
130 default:
131 fprintf(stderr, "how to free type %d?\n", e->type);
132 break;
133 }
134 free(e);
135}
136
137static int trans_count;
138
139#define e1 (*ep1)
140#define e2 (*ep2)
141
142/*
143 * expr_eliminate_eq() helper.
144 *
145 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
146 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
147 * against all other leaves. Two equal leaves are both replaced with either 'y'
148 * or 'n' as appropriate for 'type', to be eliminated later.
149 */
150static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
151{
152 /* Recurse down to leaves */
153
154 if (e1->type == type) {
155 __expr_eliminate_eq(type, &e1->left.expr, &e2);
156 __expr_eliminate_eq(type, &e1->right.expr, &e2);
157 return;
158 }
159 if (e2->type == type) {
160 __expr_eliminate_eq(type, &e1, &e2->left.expr);
161 __expr_eliminate_eq(type, &e1, &e2->right.expr);
162 return;
163 }
164
165 /* e1 and e2 are leaves. Compare them. */
166
167 if (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
168 e1->left.sym == e2->left.sym &&
169 (e1->left.sym == &symbol_yes || e1->left.sym == &symbol_no))
170 return;
171 if (!expr_eq(e1, e2))
172 return;
173
174 /* e1 and e2 are equal leaves. Prepare them for elimination. */
175
176 trans_count++;
177 expr_free(e1); expr_free(e2);
178 switch (type) {
179 case E_OR:
180 e1 = expr_alloc_symbol(&symbol_no);
181 e2 = expr_alloc_symbol(&symbol_no);
182 break;
183 case E_AND:
184 e1 = expr_alloc_symbol(&symbol_yes);
185 e2 = expr_alloc_symbol(&symbol_yes);
186 break;
187 default:
188 ;
189 }
190}
191
192/*
193 * Rewrites the expressions 'ep1' and 'ep2' to remove operands common to both.
194 * Example reductions:
195 *
196 * ep1: A && B -> ep1: y
197 * ep2: A && B && C -> ep2: C
198 *
199 * ep1: A || B -> ep1: n
200 * ep2: A || B || C -> ep2: C
201 *
202 * ep1: A && (B && FOO) -> ep1: FOO
203 * ep2: (BAR && B) && A -> ep2: BAR
204 *
205 * ep1: A && (B || C) -> ep1: y
206 * ep2: (C || B) && A -> ep2: y
207 *
208 * Comparisons are done between all operands at the same "level" of && or ||.
209 * For example, in the expression 'e1 && (e2 || e3) && (e4 || e5)', the
210 * following operands will be compared:
211 *
212 * - 'e1', 'e2 || e3', and 'e4 || e5', against each other
213 * - e2 against e3
214 * - e4 against e5
215 *
216 * Parentheses are irrelevant within a single level. 'e1 && (e2 && e3)' and
217 * '(e1 && e2) && e3' are both a single level.
218 *
219 * See __expr_eliminate_eq() as well.
220 */
221void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
222{
223 if (!e1 || !e2)
224 return;
225 switch (e1->type) {
226 case E_OR:
227 case E_AND:
228 __expr_eliminate_eq(e1->type, ep1, ep2);
229 default:
230 ;
231 }
232 if (e1->type != e2->type) switch (e2->type) {
233 case E_OR:
234 case E_AND:
235 __expr_eliminate_eq(e2->type, ep1, ep2);
236 default:
237 ;
238 }
239 e1 = expr_eliminate_yn(e1);
240 e2 = expr_eliminate_yn(e2);
241}
242
243#undef e1
244#undef e2
245
246/*
247 * Returns true if 'e1' and 'e2' are equal, after minor simplification. Two
248 * &&/|| expressions are considered equal if every operand in one expression
249 * equals some operand in the other (operands do not need to appear in the same
250 * order), recursively.
251 */
252int expr_eq(struct expr *e1, struct expr *e2)
253{
254 int res, old_count;
255
256 /*
257 * A NULL expr is taken to be yes, but there's also a different way to
258 * represent yes. expr_is_yes() checks for either representation.
259 */
260 if (!e1 || !e2)
261 return expr_is_yes(e1) && expr_is_yes(e2);
262
263 if (e1->type != e2->type)
264 return 0;
265 switch (e1->type) {
266 case E_EQUAL:
267 case E_GEQ:
268 case E_GTH:
269 case E_LEQ:
270 case E_LTH:
271 case E_UNEQUAL:
272 return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
273 case E_SYMBOL:
274 return e1->left.sym == e2->left.sym;
275 case E_NOT:
276 return expr_eq(e1->left.expr, e2->left.expr);
277 case E_AND:
278 case E_OR:
279 e1 = expr_copy(e1);
280 e2 = expr_copy(e2);
281 old_count = trans_count;
282 expr_eliminate_eq(&e1, &e2);
283 res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
284 e1->left.sym == e2->left.sym);
285 expr_free(e1);
286 expr_free(e2);
287 trans_count = old_count;
288 return res;
289 case E_LIST:
290 case E_RANGE:
291 case E_NONE:
292 /* panic */;
293 }
294
295 if (DEBUG_EXPR) {
296 expr_fprint(e1, stdout);
297 printf(" = ");
298 expr_fprint(e2, stdout);
299 printf(" ?\n");
300 }
301
302 return 0;
303}
304
305/*
306 * Recursively performs the following simplifications in-place (as well as the
307 * corresponding simplifications with swapped operands):
308 *
309 * expr && n -> n
310 * expr && y -> expr
311 * expr || n -> expr
312 * expr || y -> y
313 *
314 * Returns the optimized expression.
315 */
316static struct expr *expr_eliminate_yn(struct expr *e)
317{
318 struct expr *tmp;
319
320 if (e) switch (e->type) {
321 case E_AND:
322 e->left.expr = expr_eliminate_yn(e->left.expr);
323 e->right.expr = expr_eliminate_yn(e->right.expr);
324 if (e->left.expr->type == E_SYMBOL) {
325 if (e->left.expr->left.sym == &symbol_no) {
326 expr_free(e->left.expr);
327 expr_free(e->right.expr);
328 e->type = E_SYMBOL;
329 e->left.sym = &symbol_no;
330 e->right.expr = NULL;
331 return e;
332 } else if (e->left.expr->left.sym == &symbol_yes) {
333 free(e->left.expr);
334 tmp = e->right.expr;
335 *e = *(e->right.expr);
336 free(tmp);
337 return e;
338 }
339 }
340 if (e->right.expr->type == E_SYMBOL) {
341 if (e->right.expr->left.sym == &symbol_no) {
342 expr_free(e->left.expr);
343 expr_free(e->right.expr);
344 e->type = E_SYMBOL;
345 e->left.sym = &symbol_no;
346 e->right.expr = NULL;
347 return e;
348 } else if (e->right.expr->left.sym == &symbol_yes) {
349 free(e->right.expr);
350 tmp = e->left.expr;
351 *e = *(e->left.expr);
352 free(tmp);
353 return e;
354 }
355 }
356 break;
357 case E_OR:
358 e->left.expr = expr_eliminate_yn(e->left.expr);
359 e->right.expr = expr_eliminate_yn(e->right.expr);
360 if (e->left.expr->type == E_SYMBOL) {
361 if (e->left.expr->left.sym == &symbol_no) {
362 free(e->left.expr);
363 tmp = e->right.expr;
364 *e = *(e->right.expr);
365 free(tmp);
366 return e;
367 } else if (e->left.expr->left.sym == &symbol_yes) {
368 expr_free(e->left.expr);
369 expr_free(e->right.expr);
370 e->type = E_SYMBOL;
371 e->left.sym = &symbol_yes;
372 e->right.expr = NULL;
373 return e;
374 }
375 }
376 if (e->right.expr->type == E_SYMBOL) {
377 if (e->right.expr->left.sym == &symbol_no) {
378 free(e->right.expr);
379 tmp = e->left.expr;
380 *e = *(e->left.expr);
381 free(tmp);
382 return e;
383 } else if (e->right.expr->left.sym == &symbol_yes) {
384 expr_free(e->left.expr);
385 expr_free(e->right.expr);
386 e->type = E_SYMBOL;
387 e->left.sym = &symbol_yes;
388 e->right.expr = NULL;
389 return e;
390 }
391 }
392 break;
393 default:
394 ;
395 }
396 return e;
397}
398
399/*
400 * bool FOO!=n => FOO
401 */
402struct expr *expr_trans_bool(struct expr *e)
403{
404 if (!e)
405 return NULL;
406 switch (e->type) {
407 case E_AND:
408 case E_OR:
409 case E_NOT:
410 e->left.expr = expr_trans_bool(e->left.expr);
411 e->right.expr = expr_trans_bool(e->right.expr);
412 break;
413 case E_UNEQUAL:
414 // FOO!=n -> FOO
415 if (e->left.sym->type == S_TRISTATE) {
416 if (e->right.sym == &symbol_no) {
417 e->type = E_SYMBOL;
418 e->right.sym = NULL;
419 }
420 }
421 break;
422 default:
423 ;
424 }
425 return e;
426}
427
428/*
429 * e1 || e2 -> ?
430 */
431static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
432{
433 struct expr *tmp;
434 struct symbol *sym1, *sym2;
435
436 if (expr_eq(e1, e2))
437 return expr_copy(e1);
438 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
439 return NULL;
440 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
441 return NULL;
442 if (e1->type == E_NOT) {
443 tmp = e1->left.expr;
444 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
445 return NULL;
446 sym1 = tmp->left.sym;
447 } else
448 sym1 = e1->left.sym;
449 if (e2->type == E_NOT) {
450 if (e2->left.expr->type != E_SYMBOL)
451 return NULL;
452 sym2 = e2->left.expr->left.sym;
453 } else
454 sym2 = e2->left.sym;
455 if (sym1 != sym2)
456 return NULL;
457 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
458 return NULL;
459 if (sym1->type == S_TRISTATE) {
460 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
461 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
462 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
463 // (a='y') || (a='m') -> (a!='n')
464 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
465 }
466 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
467 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
468 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
469 // (a='y') || (a='n') -> (a!='m')
470 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
471 }
472 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
473 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
474 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
475 // (a='m') || (a='n') -> (a!='y')
476 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
477 }
478 }
479 if (sym1->type == S_BOOLEAN && sym1 == sym2) {
480 if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
481 (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
482 return expr_alloc_symbol(&symbol_yes);
483 }
484
485 if (DEBUG_EXPR) {
486 printf("optimize (");
487 expr_fprint(e1, stdout);
488 printf(") || (");
489 expr_fprint(e2, stdout);
490 printf(")?\n");
491 }
492 return NULL;
493}
494
495static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
496{
497 struct expr *tmp;
498 struct symbol *sym1, *sym2;
499
500 if (expr_eq(e1, e2))
501 return expr_copy(e1);
502 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
503 return NULL;
504 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
505 return NULL;
506 if (e1->type == E_NOT) {
507 tmp = e1->left.expr;
508 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
509 return NULL;
510 sym1 = tmp->left.sym;
511 } else
512 sym1 = e1->left.sym;
513 if (e2->type == E_NOT) {
514 if (e2->left.expr->type != E_SYMBOL)
515 return NULL;
516 sym2 = e2->left.expr->left.sym;
517 } else
518 sym2 = e2->left.sym;
519 if (sym1 != sym2)
520 return NULL;
521 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
522 return NULL;
523
524 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
525 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
526 // (a) && (a='y') -> (a='y')
527 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
528
529 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
530 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
531 // (a) && (a!='n') -> (a)
532 return expr_alloc_symbol(sym1);
533
534 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
535 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
536 // (a) && (a!='m') -> (a='y')
537 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
538
539 if (sym1->type == S_TRISTATE) {
540 if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
541 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
542 sym2 = e1->right.sym;
543 if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
544 return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
545 : expr_alloc_symbol(&symbol_no);
546 }
547 if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
548 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
549 sym2 = e2->right.sym;
550 if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
551 return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
552 : expr_alloc_symbol(&symbol_no);
553 }
554 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
555 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
556 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
557 // (a!='y') && (a!='n') -> (a='m')
558 return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
559
560 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
561 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
562 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
563 // (a!='y') && (a!='m') -> (a='n')
564 return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
565
566 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
567 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
568 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
569 // (a!='m') && (a!='n') -> (a='m')
570 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
571
572 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
573 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
574 (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
575 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
576 return NULL;
577 }
578
579 if (DEBUG_EXPR) {
580 printf("optimize (");
581 expr_fprint(e1, stdout);
582 printf(") && (");
583 expr_fprint(e2, stdout);
584 printf(")?\n");
585 }
586 return NULL;
587}
588
589/*
590 * expr_eliminate_dups() helper.
591 *
592 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
593 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
594 * against all other leaves to look for simplifications.
595 */
596static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
597{
598#define e1 (*ep1)
599#define e2 (*ep2)
600 struct expr *tmp;
601
602 /* Recurse down to leaves */
603
604 if (e1->type == type) {
605 expr_eliminate_dups1(type, &e1->left.expr, &e2);
606 expr_eliminate_dups1(type, &e1->right.expr, &e2);
607 return;
608 }
609 if (e2->type == type) {
610 expr_eliminate_dups1(type, &e1, &e2->left.expr);
611 expr_eliminate_dups1(type, &e1, &e2->right.expr);
612 return;
613 }
614
615 /* e1 and e2 are leaves. Compare and process them. */
616
617 if (e1 == e2)
618 return;
619
620 switch (e1->type) {
621 case E_OR: case E_AND:
622 expr_eliminate_dups1(e1->type, &e1, &e1);
623 default:
624 ;
625 }
626
627 switch (type) {
628 case E_OR:
629 tmp = expr_join_or(e1, e2);
630 if (tmp) {
631 expr_free(e1); expr_free(e2);
632 e1 = expr_alloc_symbol(&symbol_no);
633 e2 = tmp;
634 trans_count++;
635 }
636 break;
637 case E_AND:
638 tmp = expr_join_and(e1, e2);
639 if (tmp) {
640 expr_free(e1); expr_free(e2);
641 e1 = expr_alloc_symbol(&symbol_yes);
642 e2 = tmp;
643 trans_count++;
644 }
645 break;
646 default:
647 ;
648 }
649#undef e1
650#undef e2
651}
652
653/*
654 * Rewrites 'e' in-place to remove ("join") duplicate and other redundant
655 * operands.
656 *
657 * Example simplifications:
658 *
659 * A || B || A -> A || B
660 * A && B && A=y -> A=y && B
661 *
662 * Returns the deduplicated expression.
663 */
664struct expr *expr_eliminate_dups(struct expr *e)
665{
666 int oldcount;
667 if (!e)
668 return e;
669
670 oldcount = trans_count;
671 while (1) {
672 trans_count = 0;
673 switch (e->type) {
674 case E_OR: case E_AND:
675 expr_eliminate_dups1(e->type, &e, &e);
676 default:
677 ;
678 }
679 if (!trans_count)
680 /* No simplifications done in this pass. We're done */
681 break;
682 e = expr_eliminate_yn(e);
683 }
684 trans_count = oldcount;
685 return e;
686}
687
688/*
689 * Performs various simplifications involving logical operators and
690 * comparisons.
691 *
692 * Allocates and returns a new expression.
693 */
694struct expr *expr_transform(struct expr *e)
695{
696 struct expr *tmp;
697
698 if (!e)
699 return NULL;
700 switch (e->type) {
701 case E_EQUAL:
702 case E_GEQ:
703 case E_GTH:
704 case E_LEQ:
705 case E_LTH:
706 case E_UNEQUAL:
707 case E_SYMBOL:
708 case E_LIST:
709 break;
710 default:
711 e->left.expr = expr_transform(e->left.expr);
712 e->right.expr = expr_transform(e->right.expr);
713 }
714
715 switch (e->type) {
716 case E_EQUAL:
717 if (e->left.sym->type != S_BOOLEAN)
718 break;
719 if (e->right.sym == &symbol_no) {
720 e->type = E_NOT;
721 e->left.expr = expr_alloc_symbol(e->left.sym);
722 e->right.sym = NULL;
723 break;
724 }
725 if (e->right.sym == &symbol_mod) {
726 printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
727 e->type = E_SYMBOL;
728 e->left.sym = &symbol_no;
729 e->right.sym = NULL;
730 break;
731 }
732 if (e->right.sym == &symbol_yes) {
733 e->type = E_SYMBOL;
734 e->right.sym = NULL;
735 break;
736 }
737 break;
738 case E_UNEQUAL:
739 if (e->left.sym->type != S_BOOLEAN)
740 break;
741 if (e->right.sym == &symbol_no) {
742 e->type = E_SYMBOL;
743 e->right.sym = NULL;
744 break;
745 }
746 if (e->right.sym == &symbol_mod) {
747 printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
748 e->type = E_SYMBOL;
749 e->left.sym = &symbol_yes;
750 e->right.sym = NULL;
751 break;
752 }
753 if (e->right.sym == &symbol_yes) {
754 e->type = E_NOT;
755 e->left.expr = expr_alloc_symbol(e->left.sym);
756 e->right.sym = NULL;
757 break;
758 }
759 break;
760 case E_NOT:
761 switch (e->left.expr->type) {
762 case E_NOT:
763 // !!a -> a
764 tmp = e->left.expr->left.expr;
765 free(e->left.expr);
766 free(e);
767 e = tmp;
768 e = expr_transform(e);
769 break;
770 case E_EQUAL:
771 case E_UNEQUAL:
772 // !a='x' -> a!='x'
773 tmp = e->left.expr;
774 free(e);
775 e = tmp;
776 e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
777 break;
778 case E_LEQ:
779 case E_GEQ:
780 // !a<='x' -> a>'x'
781 tmp = e->left.expr;
782 free(e);
783 e = tmp;
784 e->type = e->type == E_LEQ ? E_GTH : E_LTH;
785 break;
786 case E_LTH:
787 case E_GTH:
788 // !a<'x' -> a>='x'
789 tmp = e->left.expr;
790 free(e);
791 e = tmp;
792 e->type = e->type == E_LTH ? E_GEQ : E_LEQ;
793 break;
794 case E_OR:
795 // !(a || b) -> !a && !b
796 tmp = e->left.expr;
797 e->type = E_AND;
798 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
799 tmp->type = E_NOT;
800 tmp->right.expr = NULL;
801 e = expr_transform(e);
802 break;
803 case E_AND:
804 // !(a && b) -> !a || !b
805 tmp = e->left.expr;
806 e->type = E_OR;
807 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
808 tmp->type = E_NOT;
809 tmp->right.expr = NULL;
810 e = expr_transform(e);
811 break;
812 case E_SYMBOL:
813 if (e->left.expr->left.sym == &symbol_yes) {
814 // !'y' -> 'n'
815 tmp = e->left.expr;
816 free(e);
817 e = tmp;
818 e->type = E_SYMBOL;
819 e->left.sym = &symbol_no;
820 break;
821 }
822 if (e->left.expr->left.sym == &symbol_mod) {
823 // !'m' -> 'm'
824 tmp = e->left.expr;
825 free(e);
826 e = tmp;
827 e->type = E_SYMBOL;
828 e->left.sym = &symbol_mod;
829 break;
830 }
831 if (e->left.expr->left.sym == &symbol_no) {
832 // !'n' -> 'y'
833 tmp = e->left.expr;
834 free(e);
835 e = tmp;
836 e->type = E_SYMBOL;
837 e->left.sym = &symbol_yes;
838 break;
839 }
840 break;
841 default:
842 ;
843 }
844 break;
845 default:
846 ;
847 }
848 return e;
849}
850
851int expr_contains_symbol(struct expr *dep, struct symbol *sym)
852{
853 if (!dep)
854 return 0;
855
856 switch (dep->type) {
857 case E_AND:
858 case E_OR:
859 return expr_contains_symbol(dep->left.expr, sym) ||
860 expr_contains_symbol(dep->right.expr, sym);
861 case E_SYMBOL:
862 return dep->left.sym == sym;
863 case E_EQUAL:
864 case E_GEQ:
865 case E_GTH:
866 case E_LEQ:
867 case E_LTH:
868 case E_UNEQUAL:
869 return dep->left.sym == sym ||
870 dep->right.sym == sym;
871 case E_NOT:
872 return expr_contains_symbol(dep->left.expr, sym);
873 default:
874 ;
875 }
876 return 0;
877}
878
879bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
880{
881 if (!dep)
882 return false;
883
884 switch (dep->type) {
885 case E_AND:
886 return expr_depends_symbol(dep->left.expr, sym) ||
887 expr_depends_symbol(dep->right.expr, sym);
888 case E_SYMBOL:
889 return dep->left.sym == sym;
890 case E_EQUAL:
891 if (dep->left.sym == sym) {
892 if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
893 return true;
894 }
895 break;
896 case E_UNEQUAL:
897 if (dep->left.sym == sym) {
898 if (dep->right.sym == &symbol_no)
899 return true;
900 }
901 break;
902 default:
903 ;
904 }
905 return false;
906}
907
908/*
909 * Inserts explicit comparisons of type 'type' to symbol 'sym' into the
910 * expression 'e'.
911 *
912 * Examples transformations for type == E_UNEQUAL, sym == &symbol_no:
913 *
914 * A -> A!=n
915 * !A -> A=n
916 * A && B -> !(A=n || B=n)
917 * A || B -> !(A=n && B=n)
918 * A && (B || C) -> !(A=n || (B=n && C=n))
919 *
920 * Allocates and returns a new expression.
921 */
922struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
923{
924 struct expr *e1, *e2;
925
926 if (!e) {
927 e = expr_alloc_symbol(sym);
928 if (type == E_UNEQUAL)
929 e = expr_alloc_one(E_NOT, e);
930 return e;
931 }
932 switch (e->type) {
933 case E_AND:
934 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
935 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
936 if (sym == &symbol_yes)
937 e = expr_alloc_two(E_AND, e1, e2);
938 if (sym == &symbol_no)
939 e = expr_alloc_two(E_OR, e1, e2);
940 if (type == E_UNEQUAL)
941 e = expr_alloc_one(E_NOT, e);
942 return e;
943 case E_OR:
944 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
945 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
946 if (sym == &symbol_yes)
947 e = expr_alloc_two(E_OR, e1, e2);
948 if (sym == &symbol_no)
949 e = expr_alloc_two(E_AND, e1, e2);
950 if (type == E_UNEQUAL)
951 e = expr_alloc_one(E_NOT, e);
952 return e;
953 case E_NOT:
954 return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
955 case E_UNEQUAL:
956 case E_LTH:
957 case E_LEQ:
958 case E_GTH:
959 case E_GEQ:
960 case E_EQUAL:
961 if (type == E_EQUAL) {
962 if (sym == &symbol_yes)
963 return expr_copy(e);
964 if (sym == &symbol_mod)
965 return expr_alloc_symbol(&symbol_no);
966 if (sym == &symbol_no)
967 return expr_alloc_one(E_NOT, expr_copy(e));
968 } else {
969 if (sym == &symbol_yes)
970 return expr_alloc_one(E_NOT, expr_copy(e));
971 if (sym == &symbol_mod)
972 return expr_alloc_symbol(&symbol_yes);
973 if (sym == &symbol_no)
974 return expr_copy(e);
975 }
976 break;
977 case E_SYMBOL:
978 return expr_alloc_comp(type, e->left.sym, sym);
979 case E_LIST:
980 case E_RANGE:
981 case E_NONE:
982 /* panic */;
983 }
984 return NULL;
985}
986
987enum string_value_kind {
988 k_string,
989 k_signed,
990 k_unsigned,
991};
992
993union string_value {
994 unsigned long long u;
995 signed long long s;
996};
997
998static enum string_value_kind expr_parse_string(const char *str,
999 enum symbol_type type,
1000 union string_value *val)
1001{
1002 char *tail;
1003 enum string_value_kind kind;
1004
1005 errno = 0;
1006 switch (type) {
1007 case S_BOOLEAN:
1008 case S_TRISTATE:
1009 val->s = !strcmp(str, "n") ? 0 :
1010 !strcmp(str, "m") ? 1 :
1011 !strcmp(str, "y") ? 2 : -1;
1012 return k_signed;
1013 case S_INT:
1014 val->s = strtoll(str, &tail, 10);
1015 kind = k_signed;
1016 break;
1017 case S_HEX:
1018 val->u = strtoull(str, &tail, 16);
1019 kind = k_unsigned;
1020 break;
1021 default:
1022 val->s = strtoll(str, &tail, 0);
1023 kind = k_signed;
1024 break;
1025 }
1026 return !errno && !*tail && tail > str && isxdigit(tail[-1])
1027 ? kind : k_string;
1028}
1029
1030tristate expr_calc_value(struct expr *e)
1031{
1032 tristate val1, val2;
1033 const char *str1, *str2;
1034 enum string_value_kind k1 = k_string, k2 = k_string;
1035 union string_value lval = {}, rval = {};
1036 int res;
1037
1038 if (!e)
1039 return yes;
1040
1041 switch (e->type) {
1042 case E_SYMBOL:
1043 sym_calc_value(e->left.sym);
1044 return e->left.sym->curr.tri;
1045 case E_AND:
1046 val1 = expr_calc_value(e->left.expr);
1047 val2 = expr_calc_value(e->right.expr);
1048 return EXPR_AND(val1, val2);
1049 case E_OR:
1050 val1 = expr_calc_value(e->left.expr);
1051 val2 = expr_calc_value(e->right.expr);
1052 return EXPR_OR(val1, val2);
1053 case E_NOT:
1054 val1 = expr_calc_value(e->left.expr);
1055 return EXPR_NOT(val1);
1056 case E_EQUAL:
1057 case E_GEQ:
1058 case E_GTH:
1059 case E_LEQ:
1060 case E_LTH:
1061 case E_UNEQUAL:
1062 break;
1063 default:
1064 printf("expr_calc_value: %d?\n", e->type);
1065 return no;
1066 }
1067
1068 sym_calc_value(e->left.sym);
1069 sym_calc_value(e->right.sym);
1070 str1 = sym_get_string_value(e->left.sym);
1071 str2 = sym_get_string_value(e->right.sym);
1072
1073 if (e->left.sym->type != S_STRING || e->right.sym->type != S_STRING) {
1074 k1 = expr_parse_string(str1, e->left.sym->type, &lval);
1075 k2 = expr_parse_string(str2, e->right.sym->type, &rval);
1076 }
1077
1078 if (k1 == k_string || k2 == k_string)
1079 res = strcmp(str1, str2);
1080 else if (k1 == k_unsigned || k2 == k_unsigned)
1081 res = (lval.u > rval.u) - (lval.u < rval.u);
1082 else /* if (k1 == k_signed && k2 == k_signed) */
1083 res = (lval.s > rval.s) - (lval.s < rval.s);
1084
1085 switch(e->type) {
1086 case E_EQUAL:
1087 return res ? no : yes;
1088 case E_GEQ:
1089 return res >= 0 ? yes : no;
1090 case E_GTH:
1091 return res > 0 ? yes : no;
1092 case E_LEQ:
1093 return res <= 0 ? yes : no;
1094 case E_LTH:
1095 return res < 0 ? yes : no;
1096 case E_UNEQUAL:
1097 return res ? yes : no;
1098 default:
1099 printf("expr_calc_value: relation %d?\n", e->type);
1100 return no;
1101 }
1102}
1103
1104static int expr_compare_type(enum expr_type t1, enum expr_type t2)
1105{
1106 if (t1 == t2)
1107 return 0;
1108 switch (t1) {
1109 case E_LEQ:
1110 case E_LTH:
1111 case E_GEQ:
1112 case E_GTH:
1113 if (t2 == E_EQUAL || t2 == E_UNEQUAL)
1114 return 1;
1115 case E_EQUAL:
1116 case E_UNEQUAL:
1117 if (t2 == E_NOT)
1118 return 1;
1119 case E_NOT:
1120 if (t2 == E_AND)
1121 return 1;
1122 case E_AND:
1123 if (t2 == E_OR)
1124 return 1;
1125 case E_OR:
1126 if (t2 == E_LIST)
1127 return 1;
1128 case E_LIST:
1129 if (t2 == 0)
1130 return 1;
1131 default:
1132 return -1;
1133 }
1134 return 0;
1135}
1136
1137void expr_print(struct expr *e,
1138 void (*fn)(void *, struct symbol *, const char *),
1139 void *data, int prevtoken)
1140{
1141 if (!e) {
1142 fn(data, NULL, "y");
1143 return;
1144 }
1145
1146 if (expr_compare_type(prevtoken, e->type) > 0)
1147 fn(data, NULL, "(");
1148 switch (e->type) {
1149 case E_SYMBOL:
1150 if (e->left.sym->name)
1151 fn(data, e->left.sym, e->left.sym->name);
1152 else
1153 fn(data, NULL, "<choice>");
1154 break;
1155 case E_NOT:
1156 fn(data, NULL, "!");
1157 expr_print(e->left.expr, fn, data, E_NOT);
1158 break;
1159 case E_EQUAL:
1160 if (e->left.sym->name)
1161 fn(data, e->left.sym, e->left.sym->name);
1162 else
1163 fn(data, NULL, "<choice>");
1164 fn(data, NULL, "=");
1165 fn(data, e->right.sym, e->right.sym->name);
1166 break;
1167 case E_LEQ:
1168 case E_LTH:
1169 if (e->left.sym->name)
1170 fn(data, e->left.sym, e->left.sym->name);
1171 else
1172 fn(data, NULL, "<choice>");
1173 fn(data, NULL, e->type == E_LEQ ? "<=" : "<");
1174 fn(data, e->right.sym, e->right.sym->name);
1175 break;
1176 case E_GEQ:
1177 case E_GTH:
1178 if (e->left.sym->name)
1179 fn(data, e->left.sym, e->left.sym->name);
1180 else
1181 fn(data, NULL, "<choice>");
1182 fn(data, NULL, e->type == E_GEQ ? ">=" : ">");
1183 fn(data, e->right.sym, e->right.sym->name);
1184 break;
1185 case E_UNEQUAL:
1186 if (e->left.sym->name)
1187 fn(data, e->left.sym, e->left.sym->name);
1188 else
1189 fn(data, NULL, "<choice>");
1190 fn(data, NULL, "!=");
1191 fn(data, e->right.sym, e->right.sym->name);
1192 break;
1193 case E_OR:
1194 expr_print(e->left.expr, fn, data, E_OR);
1195 fn(data, NULL, " || ");
1196 expr_print(e->right.expr, fn, data, E_OR);
1197 break;
1198 case E_AND:
1199 expr_print(e->left.expr, fn, data, E_AND);
1200 fn(data, NULL, " && ");
1201 expr_print(e->right.expr, fn, data, E_AND);
1202 break;
1203 case E_LIST:
1204 fn(data, e->right.sym, e->right.sym->name);
1205 if (e->left.expr) {
1206 fn(data, NULL, " ^ ");
1207 expr_print(e->left.expr, fn, data, E_LIST);
1208 }
1209 break;
1210 case E_RANGE:
1211 fn(data, NULL, "[");
1212 fn(data, e->left.sym, e->left.sym->name);
1213 fn(data, NULL, " ");
1214 fn(data, e->right.sym, e->right.sym->name);
1215 fn(data, NULL, "]");
1216 break;
1217 default:
1218 {
1219 char buf[32];
1220 sprintf(buf, "<unknown type %d>", e->type);
1221 fn(data, NULL, buf);
1222 break;
1223 }
1224 }
1225 if (expr_compare_type(prevtoken, e->type) > 0)
1226 fn(data, NULL, ")");
1227}
1228
1229static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
1230{
1231 xfwrite(str, strlen(str), 1, data);
1232}
1233
1234void expr_fprint(struct expr *e, FILE *out)
1235{
1236 expr_print(e, expr_print_file_helper, out, E_NONE);
1237}
1238
1239static void expr_print_gstr_helper(void *data, struct symbol *sym, const char *str)
1240{
1241 struct gstr *gs = (struct gstr*)data;
1242 const char *sym_str = NULL;
1243
1244 if (sym)
1245 sym_str = sym_get_string_value(sym);
1246
1247 if (gs->max_width) {
1248 unsigned extra_length = strlen(str);
1249 const char *last_cr = strrchr(gs->s, '\n');
1250 unsigned last_line_length;
1251
1252 if (sym_str)
1253 extra_length += 4 + strlen(sym_str);
1254
1255 if (!last_cr)
1256 last_cr = gs->s;
1257
1258 last_line_length = strlen(gs->s) - (last_cr - gs->s);
1259
1260 if ((last_line_length + extra_length) > gs->max_width)
1261 str_append(gs, "\\\n");
1262 }
1263
1264 str_append(gs, str);
1265 if (sym && sym->type != S_UNKNOWN)
1266 str_printf(gs, " [=%s]", sym_str);
1267}
1268
1269void expr_gstr_print(struct expr *e, struct gstr *gs)
1270{
1271 expr_print(e, expr_print_gstr_helper, gs, E_NONE);
1272}
1273
1274/*
1275 * Transform the top level "||" tokens into newlines and prepend each
1276 * line with a minus. This makes expressions much easier to read.
1277 * Suitable for reverse dependency expressions.
1278 */
1279static void expr_print_revdep(struct expr *e,
1280 void (*fn)(void *, struct symbol *, const char *),
1281 void *data, tristate pr_type, const char **title)
1282{
1283 if (e->type == E_OR) {
1284 expr_print_revdep(e->left.expr, fn, data, pr_type, title);
1285 expr_print_revdep(e->right.expr, fn, data, pr_type, title);
1286 } else if (expr_calc_value(e) == pr_type) {
1287 if (*title) {
1288 fn(data, NULL, *title);
1289 *title = NULL;
1290 }
1291
1292 fn(data, NULL, " - ");
1293 expr_print(e, fn, data, E_NONE);
1294 fn(data, NULL, "\n");
1295 }
1296}
1297
1298void expr_gstr_print_revdep(struct expr *e, struct gstr *gs,
1299 tristate pr_type, const char *title)
1300{
1301 expr_print_revdep(e, expr_print_gstr_helper, gs, pr_type, &title);
1302}
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 "lkc.h"
13
14#define DEBUG_EXPR 0
15
16static int expr_eq(struct expr *e1, struct expr *e2);
17static struct expr *expr_eliminate_yn(struct expr *e);
18
19struct expr *expr_alloc_symbol(struct symbol *sym)
20{
21 struct expr *e = xcalloc(1, sizeof(*e));
22 e->type = E_SYMBOL;
23 e->left.sym = sym;
24 return e;
25}
26
27struct expr *expr_alloc_one(enum expr_type type, struct expr *ce)
28{
29 struct expr *e = xcalloc(1, sizeof(*e));
30 e->type = type;
31 e->left.expr = ce;
32 return e;
33}
34
35struct expr *expr_alloc_two(enum expr_type type, struct expr *e1, struct expr *e2)
36{
37 struct expr *e = xcalloc(1, sizeof(*e));
38 e->type = type;
39 e->left.expr = e1;
40 e->right.expr = e2;
41 return e;
42}
43
44struct expr *expr_alloc_comp(enum expr_type type, struct symbol *s1, struct symbol *s2)
45{
46 struct expr *e = xcalloc(1, sizeof(*e));
47 e->type = type;
48 e->left.sym = s1;
49 e->right.sym = s2;
50 return e;
51}
52
53struct expr *expr_alloc_and(struct expr *e1, struct expr *e2)
54{
55 if (!e1)
56 return e2;
57 return e2 ? expr_alloc_two(E_AND, e1, e2) : e1;
58}
59
60struct expr *expr_alloc_or(struct expr *e1, struct expr *e2)
61{
62 if (!e1)
63 return e2;
64 return e2 ? expr_alloc_two(E_OR, e1, e2) : e1;
65}
66
67struct expr *expr_copy(const struct expr *org)
68{
69 struct expr *e;
70
71 if (!org)
72 return NULL;
73
74 e = xmalloc(sizeof(*org));
75 memcpy(e, org, sizeof(*org));
76 switch (org->type) {
77 case E_SYMBOL:
78 e->left = org->left;
79 break;
80 case E_NOT:
81 e->left.expr = expr_copy(org->left.expr);
82 break;
83 case E_EQUAL:
84 case E_GEQ:
85 case E_GTH:
86 case E_LEQ:
87 case E_LTH:
88 case E_UNEQUAL:
89 e->left.sym = org->left.sym;
90 e->right.sym = org->right.sym;
91 break;
92 case E_AND:
93 case E_OR:
94 case E_LIST:
95 e->left.expr = expr_copy(org->left.expr);
96 e->right.expr = expr_copy(org->right.expr);
97 break;
98 default:
99 fprintf(stderr, "can't copy type %d\n", e->type);
100 free(e);
101 e = NULL;
102 break;
103 }
104
105 return e;
106}
107
108void expr_free(struct expr *e)
109{
110 if (!e)
111 return;
112
113 switch (e->type) {
114 case E_SYMBOL:
115 break;
116 case E_NOT:
117 expr_free(e->left.expr);
118 break;
119 case E_EQUAL:
120 case E_GEQ:
121 case E_GTH:
122 case E_LEQ:
123 case E_LTH:
124 case E_UNEQUAL:
125 break;
126 case E_OR:
127 case E_AND:
128 expr_free(e->left.expr);
129 expr_free(e->right.expr);
130 break;
131 default:
132 fprintf(stderr, "how to free type %d?\n", e->type);
133 break;
134 }
135 free(e);
136}
137
138static int trans_count;
139
140#define e1 (*ep1)
141#define e2 (*ep2)
142
143/*
144 * expr_eliminate_eq() helper.
145 *
146 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
147 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
148 * against all other leaves. Two equal leaves are both replaced with either 'y'
149 * or 'n' as appropriate for 'type', to be eliminated later.
150 */
151static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
152{
153 /* Recurse down to leaves */
154
155 if (e1->type == type) {
156 __expr_eliminate_eq(type, &e1->left.expr, &e2);
157 __expr_eliminate_eq(type, &e1->right.expr, &e2);
158 return;
159 }
160 if (e2->type == type) {
161 __expr_eliminate_eq(type, &e1, &e2->left.expr);
162 __expr_eliminate_eq(type, &e1, &e2->right.expr);
163 return;
164 }
165
166 /* e1 and e2 are leaves. Compare them. */
167
168 if (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
169 e1->left.sym == e2->left.sym &&
170 (e1->left.sym == &symbol_yes || e1->left.sym == &symbol_no))
171 return;
172 if (!expr_eq(e1, e2))
173 return;
174
175 /* e1 and e2 are equal leaves. Prepare them for elimination. */
176
177 trans_count++;
178 expr_free(e1); expr_free(e2);
179 switch (type) {
180 case E_OR:
181 e1 = expr_alloc_symbol(&symbol_no);
182 e2 = expr_alloc_symbol(&symbol_no);
183 break;
184 case E_AND:
185 e1 = expr_alloc_symbol(&symbol_yes);
186 e2 = expr_alloc_symbol(&symbol_yes);
187 break;
188 default:
189 ;
190 }
191}
192
193/*
194 * Rewrites the expressions 'ep1' and 'ep2' to remove operands common to both.
195 * Example reductions:
196 *
197 * ep1: A && B -> ep1: y
198 * ep2: A && B && C -> ep2: C
199 *
200 * ep1: A || B -> ep1: n
201 * ep2: A || B || C -> ep2: C
202 *
203 * ep1: A && (B && FOO) -> ep1: FOO
204 * ep2: (BAR && B) && A -> ep2: BAR
205 *
206 * ep1: A && (B || C) -> ep1: y
207 * ep2: (C || B) && A -> ep2: y
208 *
209 * Comparisons are done between all operands at the same "level" of && or ||.
210 * For example, in the expression 'e1 && (e2 || e3) && (e4 || e5)', the
211 * following operands will be compared:
212 *
213 * - 'e1', 'e2 || e3', and 'e4 || e5', against each other
214 * - e2 against e3
215 * - e4 against e5
216 *
217 * Parentheses are irrelevant within a single level. 'e1 && (e2 && e3)' and
218 * '(e1 && e2) && e3' are both a single level.
219 *
220 * See __expr_eliminate_eq() as well.
221 */
222void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
223{
224 if (!e1 || !e2)
225 return;
226 switch (e1->type) {
227 case E_OR:
228 case E_AND:
229 __expr_eliminate_eq(e1->type, ep1, ep2);
230 default:
231 ;
232 }
233 if (e1->type != e2->type) switch (e2->type) {
234 case E_OR:
235 case E_AND:
236 __expr_eliminate_eq(e2->type, ep1, ep2);
237 default:
238 ;
239 }
240 e1 = expr_eliminate_yn(e1);
241 e2 = expr_eliminate_yn(e2);
242}
243
244#undef e1
245#undef e2
246
247/*
248 * Returns true if 'e1' and 'e2' are equal, after minor simplification. Two
249 * &&/|| expressions are considered equal if every operand in one expression
250 * equals some operand in the other (operands do not need to appear in the same
251 * order), recursively.
252 */
253static int expr_eq(struct expr *e1, struct expr *e2)
254{
255 int res, old_count;
256
257 if (e1->type != e2->type)
258 return 0;
259 switch (e1->type) {
260 case E_EQUAL:
261 case E_GEQ:
262 case E_GTH:
263 case E_LEQ:
264 case E_LTH:
265 case E_UNEQUAL:
266 return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
267 case E_SYMBOL:
268 return e1->left.sym == e2->left.sym;
269 case E_NOT:
270 return expr_eq(e1->left.expr, e2->left.expr);
271 case E_AND:
272 case E_OR:
273 e1 = expr_copy(e1);
274 e2 = expr_copy(e2);
275 old_count = trans_count;
276 expr_eliminate_eq(&e1, &e2);
277 res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
278 e1->left.sym == e2->left.sym);
279 expr_free(e1);
280 expr_free(e2);
281 trans_count = old_count;
282 return res;
283 case E_LIST:
284 case E_RANGE:
285 case E_NONE:
286 /* panic */;
287 }
288
289 if (DEBUG_EXPR) {
290 expr_fprint(e1, stdout);
291 printf(" = ");
292 expr_fprint(e2, stdout);
293 printf(" ?\n");
294 }
295
296 return 0;
297}
298
299/*
300 * Recursively performs the following simplifications in-place (as well as the
301 * corresponding simplifications with swapped operands):
302 *
303 * expr && n -> n
304 * expr && y -> expr
305 * expr || n -> expr
306 * expr || y -> y
307 *
308 * Returns the optimized expression.
309 */
310static struct expr *expr_eliminate_yn(struct expr *e)
311{
312 struct expr *tmp;
313
314 if (e) switch (e->type) {
315 case E_AND:
316 e->left.expr = expr_eliminate_yn(e->left.expr);
317 e->right.expr = expr_eliminate_yn(e->right.expr);
318 if (e->left.expr->type == E_SYMBOL) {
319 if (e->left.expr->left.sym == &symbol_no) {
320 expr_free(e->left.expr);
321 expr_free(e->right.expr);
322 e->type = E_SYMBOL;
323 e->left.sym = &symbol_no;
324 e->right.expr = NULL;
325 return e;
326 } else if (e->left.expr->left.sym == &symbol_yes) {
327 free(e->left.expr);
328 tmp = e->right.expr;
329 *e = *(e->right.expr);
330 free(tmp);
331 return e;
332 }
333 }
334 if (e->right.expr->type == E_SYMBOL) {
335 if (e->right.expr->left.sym == &symbol_no) {
336 expr_free(e->left.expr);
337 expr_free(e->right.expr);
338 e->type = E_SYMBOL;
339 e->left.sym = &symbol_no;
340 e->right.expr = NULL;
341 return e;
342 } else if (e->right.expr->left.sym == &symbol_yes) {
343 free(e->right.expr);
344 tmp = e->left.expr;
345 *e = *(e->left.expr);
346 free(tmp);
347 return e;
348 }
349 }
350 break;
351 case E_OR:
352 e->left.expr = expr_eliminate_yn(e->left.expr);
353 e->right.expr = expr_eliminate_yn(e->right.expr);
354 if (e->left.expr->type == E_SYMBOL) {
355 if (e->left.expr->left.sym == &symbol_no) {
356 free(e->left.expr);
357 tmp = e->right.expr;
358 *e = *(e->right.expr);
359 free(tmp);
360 return e;
361 } else if (e->left.expr->left.sym == &symbol_yes) {
362 expr_free(e->left.expr);
363 expr_free(e->right.expr);
364 e->type = E_SYMBOL;
365 e->left.sym = &symbol_yes;
366 e->right.expr = NULL;
367 return e;
368 }
369 }
370 if (e->right.expr->type == E_SYMBOL) {
371 if (e->right.expr->left.sym == &symbol_no) {
372 free(e->right.expr);
373 tmp = e->left.expr;
374 *e = *(e->left.expr);
375 free(tmp);
376 return e;
377 } else if (e->right.expr->left.sym == &symbol_yes) {
378 expr_free(e->left.expr);
379 expr_free(e->right.expr);
380 e->type = E_SYMBOL;
381 e->left.sym = &symbol_yes;
382 e->right.expr = NULL;
383 return e;
384 }
385 }
386 break;
387 default:
388 ;
389 }
390 return e;
391}
392
393/*
394 * bool FOO!=n => FOO
395 */
396struct expr *expr_trans_bool(struct expr *e)
397{
398 if (!e)
399 return NULL;
400 switch (e->type) {
401 case E_AND:
402 case E_OR:
403 case E_NOT:
404 e->left.expr = expr_trans_bool(e->left.expr);
405 e->right.expr = expr_trans_bool(e->right.expr);
406 break;
407 case E_UNEQUAL:
408 // FOO!=n -> FOO
409 if (e->left.sym->type == S_TRISTATE) {
410 if (e->right.sym == &symbol_no) {
411 e->type = E_SYMBOL;
412 e->right.sym = NULL;
413 }
414 }
415 break;
416 default:
417 ;
418 }
419 return e;
420}
421
422/*
423 * e1 || e2 -> ?
424 */
425static struct expr *expr_join_or(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 if (sym1->type == S_TRISTATE) {
454 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
455 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
456 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
457 // (a='y') || (a='m') -> (a!='n')
458 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
459 }
460 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
461 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
462 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
463 // (a='y') || (a='n') -> (a!='m')
464 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
465 }
466 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
467 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
468 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
469 // (a='m') || (a='n') -> (a!='y')
470 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
471 }
472 }
473 if (sym1->type == S_BOOLEAN && sym1 == sym2) {
474 if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
475 (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
476 return expr_alloc_symbol(&symbol_yes);
477 }
478
479 if (DEBUG_EXPR) {
480 printf("optimize (");
481 expr_fprint(e1, stdout);
482 printf(") || (");
483 expr_fprint(e2, stdout);
484 printf(")?\n");
485 }
486 return NULL;
487}
488
489static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
490{
491 struct expr *tmp;
492 struct symbol *sym1, *sym2;
493
494 if (expr_eq(e1, e2))
495 return expr_copy(e1);
496 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
497 return NULL;
498 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
499 return NULL;
500 if (e1->type == E_NOT) {
501 tmp = e1->left.expr;
502 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
503 return NULL;
504 sym1 = tmp->left.sym;
505 } else
506 sym1 = e1->left.sym;
507 if (e2->type == E_NOT) {
508 if (e2->left.expr->type != E_SYMBOL)
509 return NULL;
510 sym2 = e2->left.expr->left.sym;
511 } else
512 sym2 = e2->left.sym;
513 if (sym1 != sym2)
514 return NULL;
515 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
516 return NULL;
517
518 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
519 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
520 // (a) && (a='y') -> (a='y')
521 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
522
523 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
524 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
525 // (a) && (a!='n') -> (a)
526 return expr_alloc_symbol(sym1);
527
528 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
529 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
530 // (a) && (a!='m') -> (a='y')
531 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
532
533 if (sym1->type == S_TRISTATE) {
534 if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
535 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
536 sym2 = e1->right.sym;
537 if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
538 return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
539 : expr_alloc_symbol(&symbol_no);
540 }
541 if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
542 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
543 sym2 = e2->right.sym;
544 if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
545 return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
546 : expr_alloc_symbol(&symbol_no);
547 }
548 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
549 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
550 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
551 // (a!='y') && (a!='n') -> (a='m')
552 return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
553
554 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
555 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
556 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
557 // (a!='y') && (a!='m') -> (a='n')
558 return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
559
560 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
561 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
562 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
563 // (a!='m') && (a!='n') -> (a='m')
564 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
565
566 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
567 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
568 (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
569 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
570 return NULL;
571 }
572
573 if (DEBUG_EXPR) {
574 printf("optimize (");
575 expr_fprint(e1, stdout);
576 printf(") && (");
577 expr_fprint(e2, stdout);
578 printf(")?\n");
579 }
580 return NULL;
581}
582
583/*
584 * expr_eliminate_dups() helper.
585 *
586 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
587 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
588 * against all other leaves to look for simplifications.
589 */
590static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
591{
592#define e1 (*ep1)
593#define e2 (*ep2)
594 struct expr *tmp;
595
596 /* Recurse down to leaves */
597
598 if (e1->type == type) {
599 expr_eliminate_dups1(type, &e1->left.expr, &e2);
600 expr_eliminate_dups1(type, &e1->right.expr, &e2);
601 return;
602 }
603 if (e2->type == type) {
604 expr_eliminate_dups1(type, &e1, &e2->left.expr);
605 expr_eliminate_dups1(type, &e1, &e2->right.expr);
606 return;
607 }
608
609 /* e1 and e2 are leaves. Compare and process them. */
610
611 if (e1 == e2)
612 return;
613
614 switch (e1->type) {
615 case E_OR: case E_AND:
616 expr_eliminate_dups1(e1->type, &e1, &e1);
617 default:
618 ;
619 }
620
621 switch (type) {
622 case E_OR:
623 tmp = expr_join_or(e1, e2);
624 if (tmp) {
625 expr_free(e1); expr_free(e2);
626 e1 = expr_alloc_symbol(&symbol_no);
627 e2 = tmp;
628 trans_count++;
629 }
630 break;
631 case E_AND:
632 tmp = expr_join_and(e1, e2);
633 if (tmp) {
634 expr_free(e1); expr_free(e2);
635 e1 = expr_alloc_symbol(&symbol_yes);
636 e2 = tmp;
637 trans_count++;
638 }
639 break;
640 default:
641 ;
642 }
643#undef e1
644#undef e2
645}
646
647/*
648 * Rewrites 'e' in-place to remove ("join") duplicate and other redundant
649 * operands.
650 *
651 * Example simplifications:
652 *
653 * A || B || A -> A || B
654 * A && B && A=y -> A=y && B
655 *
656 * Returns the deduplicated expression.
657 */
658struct expr *expr_eliminate_dups(struct expr *e)
659{
660 int oldcount;
661 if (!e)
662 return e;
663
664 oldcount = trans_count;
665 while (1) {
666 trans_count = 0;
667 switch (e->type) {
668 case E_OR: case E_AND:
669 expr_eliminate_dups1(e->type, &e, &e);
670 default:
671 ;
672 }
673 if (!trans_count)
674 /* No simplifications done in this pass. We're done */
675 break;
676 e = expr_eliminate_yn(e);
677 }
678 trans_count = oldcount;
679 return e;
680}
681
682/*
683 * Performs various simplifications involving logical operators and
684 * comparisons.
685 *
686 * Allocates and returns a new expression.
687 */
688struct expr *expr_transform(struct expr *e)
689{
690 struct expr *tmp;
691
692 if (!e)
693 return NULL;
694 switch (e->type) {
695 case E_EQUAL:
696 case E_GEQ:
697 case E_GTH:
698 case E_LEQ:
699 case E_LTH:
700 case E_UNEQUAL:
701 case E_SYMBOL:
702 case E_LIST:
703 break;
704 default:
705 e->left.expr = expr_transform(e->left.expr);
706 e->right.expr = expr_transform(e->right.expr);
707 }
708
709 switch (e->type) {
710 case E_EQUAL:
711 if (e->left.sym->type != S_BOOLEAN)
712 break;
713 if (e->right.sym == &symbol_no) {
714 e->type = E_NOT;
715 e->left.expr = expr_alloc_symbol(e->left.sym);
716 e->right.sym = NULL;
717 break;
718 }
719 if (e->right.sym == &symbol_mod) {
720 printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
721 e->type = E_SYMBOL;
722 e->left.sym = &symbol_no;
723 e->right.sym = NULL;
724 break;
725 }
726 if (e->right.sym == &symbol_yes) {
727 e->type = E_SYMBOL;
728 e->right.sym = NULL;
729 break;
730 }
731 break;
732 case E_UNEQUAL:
733 if (e->left.sym->type != S_BOOLEAN)
734 break;
735 if (e->right.sym == &symbol_no) {
736 e->type = E_SYMBOL;
737 e->right.sym = NULL;
738 break;
739 }
740 if (e->right.sym == &symbol_mod) {
741 printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
742 e->type = E_SYMBOL;
743 e->left.sym = &symbol_yes;
744 e->right.sym = NULL;
745 break;
746 }
747 if (e->right.sym == &symbol_yes) {
748 e->type = E_NOT;
749 e->left.expr = expr_alloc_symbol(e->left.sym);
750 e->right.sym = NULL;
751 break;
752 }
753 break;
754 case E_NOT:
755 switch (e->left.expr->type) {
756 case E_NOT:
757 // !!a -> a
758 tmp = e->left.expr->left.expr;
759 free(e->left.expr);
760 free(e);
761 e = tmp;
762 e = expr_transform(e);
763 break;
764 case E_EQUAL:
765 case E_UNEQUAL:
766 // !a='x' -> a!='x'
767 tmp = e->left.expr;
768 free(e);
769 e = tmp;
770 e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
771 break;
772 case E_LEQ:
773 case E_GEQ:
774 // !a<='x' -> a>'x'
775 tmp = e->left.expr;
776 free(e);
777 e = tmp;
778 e->type = e->type == E_LEQ ? E_GTH : E_LTH;
779 break;
780 case E_LTH:
781 case E_GTH:
782 // !a<'x' -> a>='x'
783 tmp = e->left.expr;
784 free(e);
785 e = tmp;
786 e->type = e->type == E_LTH ? E_GEQ : E_LEQ;
787 break;
788 case E_OR:
789 // !(a || b) -> !a && !b
790 tmp = e->left.expr;
791 e->type = E_AND;
792 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
793 tmp->type = E_NOT;
794 tmp->right.expr = NULL;
795 e = expr_transform(e);
796 break;
797 case E_AND:
798 // !(a && b) -> !a || !b
799 tmp = e->left.expr;
800 e->type = E_OR;
801 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
802 tmp->type = E_NOT;
803 tmp->right.expr = NULL;
804 e = expr_transform(e);
805 break;
806 case E_SYMBOL:
807 if (e->left.expr->left.sym == &symbol_yes) {
808 // !'y' -> 'n'
809 tmp = e->left.expr;
810 free(e);
811 e = tmp;
812 e->type = E_SYMBOL;
813 e->left.sym = &symbol_no;
814 break;
815 }
816 if (e->left.expr->left.sym == &symbol_mod) {
817 // !'m' -> 'm'
818 tmp = e->left.expr;
819 free(e);
820 e = tmp;
821 e->type = E_SYMBOL;
822 e->left.sym = &symbol_mod;
823 break;
824 }
825 if (e->left.expr->left.sym == &symbol_no) {
826 // !'n' -> 'y'
827 tmp = e->left.expr;
828 free(e);
829 e = tmp;
830 e->type = E_SYMBOL;
831 e->left.sym = &symbol_yes;
832 break;
833 }
834 break;
835 default:
836 ;
837 }
838 break;
839 default:
840 ;
841 }
842 return e;
843}
844
845int expr_contains_symbol(struct expr *dep, struct symbol *sym)
846{
847 if (!dep)
848 return 0;
849
850 switch (dep->type) {
851 case E_AND:
852 case E_OR:
853 return expr_contains_symbol(dep->left.expr, sym) ||
854 expr_contains_symbol(dep->right.expr, sym);
855 case E_SYMBOL:
856 return dep->left.sym == sym;
857 case E_EQUAL:
858 case E_GEQ:
859 case E_GTH:
860 case E_LEQ:
861 case E_LTH:
862 case E_UNEQUAL:
863 return dep->left.sym == sym ||
864 dep->right.sym == sym;
865 case E_NOT:
866 return expr_contains_symbol(dep->left.expr, sym);
867 default:
868 ;
869 }
870 return 0;
871}
872
873bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
874{
875 if (!dep)
876 return false;
877
878 switch (dep->type) {
879 case E_AND:
880 return expr_depends_symbol(dep->left.expr, sym) ||
881 expr_depends_symbol(dep->right.expr, sym);
882 case E_SYMBOL:
883 return dep->left.sym == sym;
884 case E_EQUAL:
885 if (dep->left.sym == sym) {
886 if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
887 return true;
888 }
889 break;
890 case E_UNEQUAL:
891 if (dep->left.sym == sym) {
892 if (dep->right.sym == &symbol_no)
893 return true;
894 }
895 break;
896 default:
897 ;
898 }
899 return false;
900}
901
902/*
903 * Inserts explicit comparisons of type 'type' to symbol 'sym' into the
904 * expression 'e'.
905 *
906 * Examples transformations for type == E_UNEQUAL, sym == &symbol_no:
907 *
908 * A -> A!=n
909 * !A -> A=n
910 * A && B -> !(A=n || B=n)
911 * A || B -> !(A=n && B=n)
912 * A && (B || C) -> !(A=n || (B=n && C=n))
913 *
914 * Allocates and returns a new expression.
915 */
916struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
917{
918 struct expr *e1, *e2;
919
920 if (!e) {
921 e = expr_alloc_symbol(sym);
922 if (type == E_UNEQUAL)
923 e = expr_alloc_one(E_NOT, e);
924 return e;
925 }
926 switch (e->type) {
927 case E_AND:
928 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
929 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
930 if (sym == &symbol_yes)
931 e = expr_alloc_two(E_AND, e1, e2);
932 if (sym == &symbol_no)
933 e = expr_alloc_two(E_OR, e1, e2);
934 if (type == E_UNEQUAL)
935 e = expr_alloc_one(E_NOT, e);
936 return e;
937 case E_OR:
938 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
939 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
940 if (sym == &symbol_yes)
941 e = expr_alloc_two(E_OR, e1, e2);
942 if (sym == &symbol_no)
943 e = expr_alloc_two(E_AND, e1, e2);
944 if (type == E_UNEQUAL)
945 e = expr_alloc_one(E_NOT, e);
946 return e;
947 case E_NOT:
948 return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
949 case E_UNEQUAL:
950 case E_LTH:
951 case E_LEQ:
952 case E_GTH:
953 case E_GEQ:
954 case E_EQUAL:
955 if (type == E_EQUAL) {
956 if (sym == &symbol_yes)
957 return expr_copy(e);
958 if (sym == &symbol_mod)
959 return expr_alloc_symbol(&symbol_no);
960 if (sym == &symbol_no)
961 return expr_alloc_one(E_NOT, expr_copy(e));
962 } else {
963 if (sym == &symbol_yes)
964 return expr_alloc_one(E_NOT, expr_copy(e));
965 if (sym == &symbol_mod)
966 return expr_alloc_symbol(&symbol_yes);
967 if (sym == &symbol_no)
968 return expr_copy(e);
969 }
970 break;
971 case E_SYMBOL:
972 return expr_alloc_comp(type, e->left.sym, sym);
973 case E_LIST:
974 case E_RANGE:
975 case E_NONE:
976 /* panic */;
977 }
978 return NULL;
979}
980
981enum string_value_kind {
982 k_string,
983 k_signed,
984 k_unsigned,
985};
986
987union string_value {
988 unsigned long long u;
989 signed long long s;
990};
991
992static enum string_value_kind expr_parse_string(const char *str,
993 enum symbol_type type,
994 union string_value *val)
995{
996 char *tail;
997 enum string_value_kind kind;
998
999 errno = 0;
1000 switch (type) {
1001 case S_BOOLEAN:
1002 case S_TRISTATE:
1003 val->s = !strcmp(str, "n") ? 0 :
1004 !strcmp(str, "m") ? 1 :
1005 !strcmp(str, "y") ? 2 : -1;
1006 return k_signed;
1007 case S_INT:
1008 val->s = strtoll(str, &tail, 10);
1009 kind = k_signed;
1010 break;
1011 case S_HEX:
1012 val->u = strtoull(str, &tail, 16);
1013 kind = k_unsigned;
1014 break;
1015 default:
1016 val->s = strtoll(str, &tail, 0);
1017 kind = k_signed;
1018 break;
1019 }
1020 return !errno && !*tail && tail > str && isxdigit(tail[-1])
1021 ? kind : k_string;
1022}
1023
1024tristate expr_calc_value(struct expr *e)
1025{
1026 tristate val1, val2;
1027 const char *str1, *str2;
1028 enum string_value_kind k1 = k_string, k2 = k_string;
1029 union string_value lval = {}, rval = {};
1030 int res;
1031
1032 if (!e)
1033 return yes;
1034
1035 switch (e->type) {
1036 case E_SYMBOL:
1037 sym_calc_value(e->left.sym);
1038 return e->left.sym->curr.tri;
1039 case E_AND:
1040 val1 = expr_calc_value(e->left.expr);
1041 val2 = expr_calc_value(e->right.expr);
1042 return EXPR_AND(val1, val2);
1043 case E_OR:
1044 val1 = expr_calc_value(e->left.expr);
1045 val2 = expr_calc_value(e->right.expr);
1046 return EXPR_OR(val1, val2);
1047 case E_NOT:
1048 val1 = expr_calc_value(e->left.expr);
1049 return EXPR_NOT(val1);
1050 case E_EQUAL:
1051 case E_GEQ:
1052 case E_GTH:
1053 case E_LEQ:
1054 case E_LTH:
1055 case E_UNEQUAL:
1056 break;
1057 default:
1058 printf("expr_calc_value: %d?\n", e->type);
1059 return no;
1060 }
1061
1062 sym_calc_value(e->left.sym);
1063 sym_calc_value(e->right.sym);
1064 str1 = sym_get_string_value(e->left.sym);
1065 str2 = sym_get_string_value(e->right.sym);
1066
1067 if (e->left.sym->type != S_STRING || e->right.sym->type != S_STRING) {
1068 k1 = expr_parse_string(str1, e->left.sym->type, &lval);
1069 k2 = expr_parse_string(str2, e->right.sym->type, &rval);
1070 }
1071
1072 if (k1 == k_string || k2 == k_string)
1073 res = strcmp(str1, str2);
1074 else if (k1 == k_unsigned || k2 == k_unsigned)
1075 res = (lval.u > rval.u) - (lval.u < rval.u);
1076 else /* if (k1 == k_signed && k2 == k_signed) */
1077 res = (lval.s > rval.s) - (lval.s < rval.s);
1078
1079 switch(e->type) {
1080 case E_EQUAL:
1081 return res ? no : yes;
1082 case E_GEQ:
1083 return res >= 0 ? yes : no;
1084 case E_GTH:
1085 return res > 0 ? yes : no;
1086 case E_LEQ:
1087 return res <= 0 ? yes : no;
1088 case E_LTH:
1089 return res < 0 ? yes : no;
1090 case E_UNEQUAL:
1091 return res ? yes : no;
1092 default:
1093 printf("expr_calc_value: relation %d?\n", e->type);
1094 return no;
1095 }
1096}
1097
1098static int expr_compare_type(enum expr_type t1, enum expr_type t2)
1099{
1100 if (t1 == t2)
1101 return 0;
1102 switch (t1) {
1103 case E_LEQ:
1104 case E_LTH:
1105 case E_GEQ:
1106 case E_GTH:
1107 if (t2 == E_EQUAL || t2 == E_UNEQUAL)
1108 return 1;
1109 case E_EQUAL:
1110 case E_UNEQUAL:
1111 if (t2 == E_NOT)
1112 return 1;
1113 case E_NOT:
1114 if (t2 == E_AND)
1115 return 1;
1116 case E_AND:
1117 if (t2 == E_OR)
1118 return 1;
1119 case E_OR:
1120 if (t2 == E_LIST)
1121 return 1;
1122 case E_LIST:
1123 if (t2 == 0)
1124 return 1;
1125 default:
1126 return -1;
1127 }
1128 printf("[%dgt%d?]", t1, t2);
1129 return 0;
1130}
1131
1132void expr_print(struct expr *e,
1133 void (*fn)(void *, struct symbol *, const char *),
1134 void *data, int prevtoken)
1135{
1136 if (!e) {
1137 fn(data, NULL, "y");
1138 return;
1139 }
1140
1141 if (expr_compare_type(prevtoken, e->type) > 0)
1142 fn(data, NULL, "(");
1143 switch (e->type) {
1144 case E_SYMBOL:
1145 if (e->left.sym->name)
1146 fn(data, e->left.sym, e->left.sym->name);
1147 else
1148 fn(data, NULL, "<choice>");
1149 break;
1150 case E_NOT:
1151 fn(data, NULL, "!");
1152 expr_print(e->left.expr, fn, data, E_NOT);
1153 break;
1154 case E_EQUAL:
1155 if (e->left.sym->name)
1156 fn(data, e->left.sym, e->left.sym->name);
1157 else
1158 fn(data, NULL, "<choice>");
1159 fn(data, NULL, "=");
1160 fn(data, e->right.sym, e->right.sym->name);
1161 break;
1162 case E_LEQ:
1163 case E_LTH:
1164 if (e->left.sym->name)
1165 fn(data, e->left.sym, e->left.sym->name);
1166 else
1167 fn(data, NULL, "<choice>");
1168 fn(data, NULL, e->type == E_LEQ ? "<=" : "<");
1169 fn(data, e->right.sym, e->right.sym->name);
1170 break;
1171 case E_GEQ:
1172 case E_GTH:
1173 if (e->left.sym->name)
1174 fn(data, e->left.sym, e->left.sym->name);
1175 else
1176 fn(data, NULL, "<choice>");
1177 fn(data, NULL, e->type == E_GEQ ? ">=" : ">");
1178 fn(data, e->right.sym, e->right.sym->name);
1179 break;
1180 case E_UNEQUAL:
1181 if (e->left.sym->name)
1182 fn(data, e->left.sym, e->left.sym->name);
1183 else
1184 fn(data, NULL, "<choice>");
1185 fn(data, NULL, "!=");
1186 fn(data, e->right.sym, e->right.sym->name);
1187 break;
1188 case E_OR:
1189 expr_print(e->left.expr, fn, data, E_OR);
1190 fn(data, NULL, " || ");
1191 expr_print(e->right.expr, fn, data, E_OR);
1192 break;
1193 case E_AND:
1194 expr_print(e->left.expr, fn, data, E_AND);
1195 fn(data, NULL, " && ");
1196 expr_print(e->right.expr, fn, data, E_AND);
1197 break;
1198 case E_LIST:
1199 fn(data, e->right.sym, e->right.sym->name);
1200 if (e->left.expr) {
1201 fn(data, NULL, " ^ ");
1202 expr_print(e->left.expr, fn, data, E_LIST);
1203 }
1204 break;
1205 case E_RANGE:
1206 fn(data, NULL, "[");
1207 fn(data, e->left.sym, e->left.sym->name);
1208 fn(data, NULL, " ");
1209 fn(data, e->right.sym, e->right.sym->name);
1210 fn(data, NULL, "]");
1211 break;
1212 default:
1213 {
1214 char buf[32];
1215 sprintf(buf, "<unknown type %d>", e->type);
1216 fn(data, NULL, buf);
1217 break;
1218 }
1219 }
1220 if (expr_compare_type(prevtoken, e->type) > 0)
1221 fn(data, NULL, ")");
1222}
1223
1224static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
1225{
1226 xfwrite(str, strlen(str), 1, data);
1227}
1228
1229void expr_fprint(struct expr *e, FILE *out)
1230{
1231 expr_print(e, expr_print_file_helper, out, E_NONE);
1232}
1233
1234static void expr_print_gstr_helper(void *data, struct symbol *sym, const char *str)
1235{
1236 struct gstr *gs = (struct gstr*)data;
1237 const char *sym_str = NULL;
1238
1239 if (sym)
1240 sym_str = sym_get_string_value(sym);
1241
1242 if (gs->max_width) {
1243 unsigned extra_length = strlen(str);
1244 const char *last_cr = strrchr(gs->s, '\n');
1245 unsigned last_line_length;
1246
1247 if (sym_str)
1248 extra_length += 4 + strlen(sym_str);
1249
1250 if (!last_cr)
1251 last_cr = gs->s;
1252
1253 last_line_length = strlen(gs->s) - (last_cr - gs->s);
1254
1255 if ((last_line_length + extra_length) > gs->max_width)
1256 str_append(gs, "\\\n");
1257 }
1258
1259 str_append(gs, str);
1260 if (sym && sym->type != S_UNKNOWN)
1261 str_printf(gs, " [=%s]", sym_str);
1262}
1263
1264void expr_gstr_print(struct expr *e, struct gstr *gs)
1265{
1266 expr_print(e, expr_print_gstr_helper, gs, E_NONE);
1267}
1268
1269/*
1270 * Transform the top level "||" tokens into newlines and prepend each
1271 * line with a minus. This makes expressions much easier to read.
1272 * Suitable for reverse dependency expressions.
1273 */
1274static void expr_print_revdep(struct expr *e,
1275 void (*fn)(void *, struct symbol *, const char *),
1276 void *data, tristate pr_type, const char **title)
1277{
1278 if (e->type == E_OR) {
1279 expr_print_revdep(e->left.expr, fn, data, pr_type, title);
1280 expr_print_revdep(e->right.expr, fn, data, pr_type, title);
1281 } else if (expr_calc_value(e) == pr_type) {
1282 if (*title) {
1283 fn(data, NULL, *title);
1284 *title = NULL;
1285 }
1286
1287 fn(data, NULL, " - ");
1288 expr_print(e, fn, data, E_NONE);
1289 fn(data, NULL, "\n");
1290 }
1291}
1292
1293void expr_gstr_print_revdep(struct expr *e, struct gstr *gs,
1294 tristate pr_type, const char *title)
1295{
1296 expr_print_revdep(e, expr_print_gstr_helper, gs, pr_type, &title);
1297}