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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/*
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 fprintf(stderr, "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 break;
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 fprintf(stderr, "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
141/*
142 * expr_eliminate_eq() helper.
143 *
144 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
145 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
146 * against all other leaves. Two equal leaves are both replaced with either 'y'
147 * or 'n' as appropriate for 'type', to be eliminated later.
148 */
149static void __expr_eliminate_eq(enum expr_type type, struct expr **ep1, struct expr **ep2)
150{
151 /* Recurse down to leaves */
152
153 if (e1->type == type) {
154 __expr_eliminate_eq(type, &e1->left.expr, &e2);
155 __expr_eliminate_eq(type, &e1->right.expr, &e2);
156 return;
157 }
158 if (e2->type == type) {
159 __expr_eliminate_eq(type, &e1, &e2->left.expr);
160 __expr_eliminate_eq(type, &e1, &e2->right.expr);
161 return;
162 }
163
164 /* e1 and e2 are leaves. Compare them. */
165
166 if (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
167 e1->left.sym == e2->left.sym &&
168 (e1->left.sym == &symbol_yes || e1->left.sym == &symbol_no))
169 return;
170 if (!expr_eq(e1, e2))
171 return;
172
173 /* e1 and e2 are equal leaves. Prepare them for elimination. */
174
175 trans_count++;
176 expr_free(e1); expr_free(e2);
177 switch (type) {
178 case E_OR:
179 e1 = expr_alloc_symbol(&symbol_no);
180 e2 = expr_alloc_symbol(&symbol_no);
181 break;
182 case E_AND:
183 e1 = expr_alloc_symbol(&symbol_yes);
184 e2 = expr_alloc_symbol(&symbol_yes);
185 break;
186 default:
187 ;
188 }
189}
190
191/*
192 * Rewrites the expressions 'ep1' and 'ep2' to remove operands common to both.
193 * Example reductions:
194 *
195 * ep1: A && B -> ep1: y
196 * ep2: A && B && C -> ep2: C
197 *
198 * ep1: A || B -> ep1: n
199 * ep2: A || B || C -> ep2: C
200 *
201 * ep1: A && (B && FOO) -> ep1: FOO
202 * ep2: (BAR && B) && A -> ep2: BAR
203 *
204 * ep1: A && (B || C) -> ep1: y
205 * ep2: (C || B) && A -> ep2: y
206 *
207 * Comparisons are done between all operands at the same "level" of && or ||.
208 * For example, in the expression 'e1 && (e2 || e3) && (e4 || e5)', the
209 * following operands will be compared:
210 *
211 * - 'e1', 'e2 || e3', and 'e4 || e5', against each other
212 * - e2 against e3
213 * - e4 against e5
214 *
215 * Parentheses are irrelevant within a single level. 'e1 && (e2 && e3)' and
216 * '(e1 && e2) && e3' are both a single level.
217 *
218 * See __expr_eliminate_eq() as well.
219 */
220void expr_eliminate_eq(struct expr **ep1, struct expr **ep2)
221{
222 if (!e1 || !e2)
223 return;
224 switch (e1->type) {
225 case E_OR:
226 case E_AND:
227 __expr_eliminate_eq(e1->type, ep1, ep2);
228 default:
229 ;
230 }
231 if (e1->type != e2->type) switch (e2->type) {
232 case E_OR:
233 case E_AND:
234 __expr_eliminate_eq(e2->type, ep1, ep2);
235 default:
236 ;
237 }
238 e1 = expr_eliminate_yn(e1);
239 e2 = expr_eliminate_yn(e2);
240}
241
242#undef e1
243#undef e2
244
245/*
246 * Returns true if 'e1' and 'e2' are equal, after minor simplification. Two
247 * &&/|| expressions are considered equal if every operand in one expression
248 * equals some operand in the other (operands do not need to appear in the same
249 * order), recursively.
250 */
251static int expr_eq(struct expr *e1, struct expr *e2)
252{
253 int res, old_count;
254
255 if (e1->type != e2->type)
256 return 0;
257 switch (e1->type) {
258 case E_EQUAL:
259 case E_GEQ:
260 case E_GTH:
261 case E_LEQ:
262 case E_LTH:
263 case E_UNEQUAL:
264 return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
265 case E_SYMBOL:
266 return e1->left.sym == e2->left.sym;
267 case E_NOT:
268 return expr_eq(e1->left.expr, e2->left.expr);
269 case E_AND:
270 case E_OR:
271 e1 = expr_copy(e1);
272 e2 = expr_copy(e2);
273 old_count = trans_count;
274 expr_eliminate_eq(&e1, &e2);
275 res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
276 e1->left.sym == e2->left.sym);
277 expr_free(e1);
278 expr_free(e2);
279 trans_count = old_count;
280 return res;
281 case E_LIST:
282 case E_RANGE:
283 case E_NONE:
284 /* panic */;
285 }
286
287 if (DEBUG_EXPR) {
288 expr_fprint(e1, stdout);
289 printf(" = ");
290 expr_fprint(e2, stdout);
291 printf(" ?\n");
292 }
293
294 return 0;
295}
296
297/*
298 * Recursively performs the following simplifications in-place (as well as the
299 * corresponding simplifications with swapped operands):
300 *
301 * expr && n -> n
302 * expr && y -> expr
303 * expr || n -> expr
304 * expr || y -> y
305 *
306 * Returns the optimized expression.
307 */
308static struct expr *expr_eliminate_yn(struct expr *e)
309{
310 struct expr *tmp;
311
312 if (e) switch (e->type) {
313 case E_AND:
314 e->left.expr = expr_eliminate_yn(e->left.expr);
315 e->right.expr = expr_eliminate_yn(e->right.expr);
316 if (e->left.expr->type == E_SYMBOL) {
317 if (e->left.expr->left.sym == &symbol_no) {
318 expr_free(e->left.expr);
319 expr_free(e->right.expr);
320 e->type = E_SYMBOL;
321 e->left.sym = &symbol_no;
322 e->right.expr = NULL;
323 return e;
324 } else if (e->left.expr->left.sym == &symbol_yes) {
325 free(e->left.expr);
326 tmp = e->right.expr;
327 *e = *(e->right.expr);
328 free(tmp);
329 return e;
330 }
331 }
332 if (e->right.expr->type == E_SYMBOL) {
333 if (e->right.expr->left.sym == &symbol_no) {
334 expr_free(e->left.expr);
335 expr_free(e->right.expr);
336 e->type = E_SYMBOL;
337 e->left.sym = &symbol_no;
338 e->right.expr = NULL;
339 return e;
340 } else if (e->right.expr->left.sym == &symbol_yes) {
341 free(e->right.expr);
342 tmp = e->left.expr;
343 *e = *(e->left.expr);
344 free(tmp);
345 return e;
346 }
347 }
348 break;
349 case E_OR:
350 e->left.expr = expr_eliminate_yn(e->left.expr);
351 e->right.expr = expr_eliminate_yn(e->right.expr);
352 if (e->left.expr->type == E_SYMBOL) {
353 if (e->left.expr->left.sym == &symbol_no) {
354 free(e->left.expr);
355 tmp = e->right.expr;
356 *e = *(e->right.expr);
357 free(tmp);
358 return e;
359 } else if (e->left.expr->left.sym == &symbol_yes) {
360 expr_free(e->left.expr);
361 expr_free(e->right.expr);
362 e->type = E_SYMBOL;
363 e->left.sym = &symbol_yes;
364 e->right.expr = NULL;
365 return e;
366 }
367 }
368 if (e->right.expr->type == E_SYMBOL) {
369 if (e->right.expr->left.sym == &symbol_no) {
370 free(e->right.expr);
371 tmp = e->left.expr;
372 *e = *(e->left.expr);
373 free(tmp);
374 return e;
375 } else if (e->right.expr->left.sym == &symbol_yes) {
376 expr_free(e->left.expr);
377 expr_free(e->right.expr);
378 e->type = E_SYMBOL;
379 e->left.sym = &symbol_yes;
380 e->right.expr = NULL;
381 return e;
382 }
383 }
384 break;
385 default:
386 ;
387 }
388 return e;
389}
390
391/*
392 * bool FOO!=n => FOO
393 */
394struct expr *expr_trans_bool(struct expr *e)
395{
396 if (!e)
397 return NULL;
398 switch (e->type) {
399 case E_AND:
400 case E_OR:
401 case E_NOT:
402 e->left.expr = expr_trans_bool(e->left.expr);
403 e->right.expr = expr_trans_bool(e->right.expr);
404 break;
405 case E_UNEQUAL:
406 // FOO!=n -> FOO
407 if (e->left.sym->type == S_TRISTATE) {
408 if (e->right.sym == &symbol_no) {
409 e->type = E_SYMBOL;
410 e->right.sym = NULL;
411 }
412 }
413 break;
414 default:
415 ;
416 }
417 return e;
418}
419
420/*
421 * e1 || e2 -> ?
422 */
423static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
424{
425 struct expr *tmp;
426 struct symbol *sym1, *sym2;
427
428 if (expr_eq(e1, e2))
429 return expr_copy(e1);
430 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
431 return NULL;
432 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
433 return NULL;
434 if (e1->type == E_NOT) {
435 tmp = e1->left.expr;
436 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
437 return NULL;
438 sym1 = tmp->left.sym;
439 } else
440 sym1 = e1->left.sym;
441 if (e2->type == E_NOT) {
442 if (e2->left.expr->type != E_SYMBOL)
443 return NULL;
444 sym2 = e2->left.expr->left.sym;
445 } else
446 sym2 = e2->left.sym;
447 if (sym1 != sym2)
448 return NULL;
449 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
450 return NULL;
451 if (sym1->type == S_TRISTATE) {
452 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
453 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
454 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
455 // (a='y') || (a='m') -> (a!='n')
456 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
457 }
458 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
459 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
460 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
461 // (a='y') || (a='n') -> (a!='m')
462 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
463 }
464 if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
465 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
466 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
467 // (a='m') || (a='n') -> (a!='y')
468 return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
469 }
470 }
471 if (sym1->type == S_BOOLEAN && sym1 == sym2) {
472 if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
473 (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
474 return expr_alloc_symbol(&symbol_yes);
475 }
476
477 if (DEBUG_EXPR) {
478 printf("optimize (");
479 expr_fprint(e1, stdout);
480 printf(") || (");
481 expr_fprint(e2, stdout);
482 printf(")?\n");
483 }
484 return NULL;
485}
486
487static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
488{
489 struct expr *tmp;
490 struct symbol *sym1, *sym2;
491
492 if (expr_eq(e1, e2))
493 return expr_copy(e1);
494 if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
495 return NULL;
496 if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
497 return NULL;
498 if (e1->type == E_NOT) {
499 tmp = e1->left.expr;
500 if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
501 return NULL;
502 sym1 = tmp->left.sym;
503 } else
504 sym1 = e1->left.sym;
505 if (e2->type == E_NOT) {
506 if (e2->left.expr->type != E_SYMBOL)
507 return NULL;
508 sym2 = e2->left.expr->left.sym;
509 } else
510 sym2 = e2->left.sym;
511 if (sym1 != sym2)
512 return NULL;
513 if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
514 return NULL;
515
516 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
517 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
518 // (a) && (a='y') -> (a='y')
519 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
520
521 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
522 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
523 // (a) && (a!='n') -> (a)
524 return expr_alloc_symbol(sym1);
525
526 if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
527 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
528 // (a) && (a!='m') -> (a='y')
529 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
530
531 if (sym1->type == S_TRISTATE) {
532 if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
533 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
534 sym2 = e1->right.sym;
535 if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
536 return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
537 : expr_alloc_symbol(&symbol_no);
538 }
539 if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
540 // (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
541 sym2 = e2->right.sym;
542 if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
543 return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
544 : expr_alloc_symbol(&symbol_no);
545 }
546 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
547 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
548 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
549 // (a!='y') && (a!='n') -> (a='m')
550 return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
551
552 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
553 ((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
554 (e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
555 // (a!='y') && (a!='m') -> (a='n')
556 return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
557
558 if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
559 ((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
560 (e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
561 // (a!='m') && (a!='n') -> (a='m')
562 return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
563
564 if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
565 (e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
566 (e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
567 (e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
568 return NULL;
569 }
570
571 if (DEBUG_EXPR) {
572 printf("optimize (");
573 expr_fprint(e1, stdout);
574 printf(") && (");
575 expr_fprint(e2, stdout);
576 printf(")?\n");
577 }
578 return NULL;
579}
580
581/*
582 * expr_eliminate_dups() helper.
583 *
584 * Walks the two expression trees given in 'ep1' and 'ep2'. Any node that does
585 * not have type 'type' (E_OR/E_AND) is considered a leaf, and is compared
586 * against all other leaves to look for simplifications.
587 */
588static void expr_eliminate_dups1(enum expr_type type, struct expr **ep1, struct expr **ep2)
589{
590#define e1 (*ep1)
591#define e2 (*ep2)
592 struct expr *tmp;
593
594 /* Recurse down to leaves */
595
596 if (e1->type == type) {
597 expr_eliminate_dups1(type, &e1->left.expr, &e2);
598 expr_eliminate_dups1(type, &e1->right.expr, &e2);
599 return;
600 }
601 if (e2->type == type) {
602 expr_eliminate_dups1(type, &e1, &e2->left.expr);
603 expr_eliminate_dups1(type, &e1, &e2->right.expr);
604 return;
605 }
606
607 /* e1 and e2 are leaves. Compare and process them. */
608
609 if (e1 == e2)
610 return;
611
612 switch (e1->type) {
613 case E_OR: case E_AND:
614 expr_eliminate_dups1(e1->type, &e1, &e1);
615 default:
616 ;
617 }
618
619 switch (type) {
620 case E_OR:
621 tmp = expr_join_or(e1, e2);
622 if (tmp) {
623 expr_free(e1); expr_free(e2);
624 e1 = expr_alloc_symbol(&symbol_no);
625 e2 = tmp;
626 trans_count++;
627 }
628 break;
629 case E_AND:
630 tmp = expr_join_and(e1, e2);
631 if (tmp) {
632 expr_free(e1); expr_free(e2);
633 e1 = expr_alloc_symbol(&symbol_yes);
634 e2 = tmp;
635 trans_count++;
636 }
637 break;
638 default:
639 ;
640 }
641#undef e1
642#undef e2
643}
644
645/*
646 * Rewrites 'e' in-place to remove ("join") duplicate and other redundant
647 * operands.
648 *
649 * Example simplifications:
650 *
651 * A || B || A -> A || B
652 * A && B && A=y -> A=y && B
653 *
654 * Returns the deduplicated expression.
655 */
656struct expr *expr_eliminate_dups(struct expr *e)
657{
658 int oldcount;
659 if (!e)
660 return e;
661
662 oldcount = trans_count;
663 while (1) {
664 trans_count = 0;
665 switch (e->type) {
666 case E_OR: case E_AND:
667 expr_eliminate_dups1(e->type, &e, &e);
668 default:
669 ;
670 }
671 if (!trans_count)
672 /* No simplifications done in this pass. We're done */
673 break;
674 e = expr_eliminate_yn(e);
675 }
676 trans_count = oldcount;
677 return e;
678}
679
680/*
681 * Performs various simplifications involving logical operators and
682 * comparisons.
683 *
684 * Allocates and returns a new expression.
685 */
686struct expr *expr_transform(struct expr *e)
687{
688 struct expr *tmp;
689
690 if (!e)
691 return NULL;
692 switch (e->type) {
693 case E_EQUAL:
694 case E_GEQ:
695 case E_GTH:
696 case E_LEQ:
697 case E_LTH:
698 case E_UNEQUAL:
699 case E_SYMBOL:
700 case E_LIST:
701 break;
702 default:
703 e->left.expr = expr_transform(e->left.expr);
704 e->right.expr = expr_transform(e->right.expr);
705 }
706
707 switch (e->type) {
708 case E_EQUAL:
709 if (e->left.sym->type != S_BOOLEAN)
710 break;
711 if (e->right.sym == &symbol_no) {
712 e->type = E_NOT;
713 e->left.expr = expr_alloc_symbol(e->left.sym);
714 e->right.sym = NULL;
715 break;
716 }
717 if (e->right.sym == &symbol_mod) {
718 printf("boolean symbol %s tested for 'm'? test forced to 'n'\n", e->left.sym->name);
719 e->type = E_SYMBOL;
720 e->left.sym = &symbol_no;
721 e->right.sym = NULL;
722 break;
723 }
724 if (e->right.sym == &symbol_yes) {
725 e->type = E_SYMBOL;
726 e->right.sym = NULL;
727 break;
728 }
729 break;
730 case E_UNEQUAL:
731 if (e->left.sym->type != S_BOOLEAN)
732 break;
733 if (e->right.sym == &symbol_no) {
734 e->type = E_SYMBOL;
735 e->right.sym = NULL;
736 break;
737 }
738 if (e->right.sym == &symbol_mod) {
739 printf("boolean symbol %s tested for 'm'? test forced to 'y'\n", e->left.sym->name);
740 e->type = E_SYMBOL;
741 e->left.sym = &symbol_yes;
742 e->right.sym = NULL;
743 break;
744 }
745 if (e->right.sym == &symbol_yes) {
746 e->type = E_NOT;
747 e->left.expr = expr_alloc_symbol(e->left.sym);
748 e->right.sym = NULL;
749 break;
750 }
751 break;
752 case E_NOT:
753 switch (e->left.expr->type) {
754 case E_NOT:
755 // !!a -> a
756 tmp = e->left.expr->left.expr;
757 free(e->left.expr);
758 free(e);
759 e = tmp;
760 e = expr_transform(e);
761 break;
762 case E_EQUAL:
763 case E_UNEQUAL:
764 // !a='x' -> a!='x'
765 tmp = e->left.expr;
766 free(e);
767 e = tmp;
768 e->type = e->type == E_EQUAL ? E_UNEQUAL : E_EQUAL;
769 break;
770 case E_LEQ:
771 case E_GEQ:
772 // !a<='x' -> a>'x'
773 tmp = e->left.expr;
774 free(e);
775 e = tmp;
776 e->type = e->type == E_LEQ ? E_GTH : E_LTH;
777 break;
778 case E_LTH:
779 case E_GTH:
780 // !a<'x' -> a>='x'
781 tmp = e->left.expr;
782 free(e);
783 e = tmp;
784 e->type = e->type == E_LTH ? E_GEQ : E_LEQ;
785 break;
786 case E_OR:
787 // !(a || b) -> !a && !b
788 tmp = e->left.expr;
789 e->type = E_AND;
790 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
791 tmp->type = E_NOT;
792 tmp->right.expr = NULL;
793 e = expr_transform(e);
794 break;
795 case E_AND:
796 // !(a && b) -> !a || !b
797 tmp = e->left.expr;
798 e->type = E_OR;
799 e->right.expr = expr_alloc_one(E_NOT, tmp->right.expr);
800 tmp->type = E_NOT;
801 tmp->right.expr = NULL;
802 e = expr_transform(e);
803 break;
804 case E_SYMBOL:
805 if (e->left.expr->left.sym == &symbol_yes) {
806 // !'y' -> 'n'
807 tmp = e->left.expr;
808 free(e);
809 e = tmp;
810 e->type = E_SYMBOL;
811 e->left.sym = &symbol_no;
812 break;
813 }
814 if (e->left.expr->left.sym == &symbol_mod) {
815 // !'m' -> 'm'
816 tmp = e->left.expr;
817 free(e);
818 e = tmp;
819 e->type = E_SYMBOL;
820 e->left.sym = &symbol_mod;
821 break;
822 }
823 if (e->left.expr->left.sym == &symbol_no) {
824 // !'n' -> 'y'
825 tmp = e->left.expr;
826 free(e);
827 e = tmp;
828 e->type = E_SYMBOL;
829 e->left.sym = &symbol_yes;
830 break;
831 }
832 break;
833 default:
834 ;
835 }
836 break;
837 default:
838 ;
839 }
840 return e;
841}
842
843int expr_contains_symbol(struct expr *dep, struct symbol *sym)
844{
845 if (!dep)
846 return 0;
847
848 switch (dep->type) {
849 case E_AND:
850 case E_OR:
851 return expr_contains_symbol(dep->left.expr, sym) ||
852 expr_contains_symbol(dep->right.expr, sym);
853 case E_SYMBOL:
854 return dep->left.sym == sym;
855 case E_EQUAL:
856 case E_GEQ:
857 case E_GTH:
858 case E_LEQ:
859 case E_LTH:
860 case E_UNEQUAL:
861 return dep->left.sym == sym ||
862 dep->right.sym == sym;
863 case E_NOT:
864 return expr_contains_symbol(dep->left.expr, sym);
865 default:
866 ;
867 }
868 return 0;
869}
870
871bool expr_depends_symbol(struct expr *dep, struct symbol *sym)
872{
873 if (!dep)
874 return false;
875
876 switch (dep->type) {
877 case E_AND:
878 return expr_depends_symbol(dep->left.expr, sym) ||
879 expr_depends_symbol(dep->right.expr, sym);
880 case E_SYMBOL:
881 return dep->left.sym == sym;
882 case E_EQUAL:
883 if (dep->left.sym == sym) {
884 if (dep->right.sym == &symbol_yes || dep->right.sym == &symbol_mod)
885 return true;
886 }
887 break;
888 case E_UNEQUAL:
889 if (dep->left.sym == sym) {
890 if (dep->right.sym == &symbol_no)
891 return true;
892 }
893 break;
894 default:
895 ;
896 }
897 return false;
898}
899
900/*
901 * Inserts explicit comparisons of type 'type' to symbol 'sym' into the
902 * expression 'e'.
903 *
904 * Examples transformations for type == E_UNEQUAL, sym == &symbol_no:
905 *
906 * A -> A!=n
907 * !A -> A=n
908 * A && B -> !(A=n || B=n)
909 * A || B -> !(A=n && B=n)
910 * A && (B || C) -> !(A=n || (B=n && C=n))
911 *
912 * Allocates and returns a new expression.
913 */
914struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym)
915{
916 struct expr *e1, *e2;
917
918 if (!e) {
919 e = expr_alloc_symbol(sym);
920 if (type == E_UNEQUAL)
921 e = expr_alloc_one(E_NOT, e);
922 return e;
923 }
924 switch (e->type) {
925 case E_AND:
926 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
927 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
928 if (sym == &symbol_yes)
929 e = expr_alloc_two(E_AND, e1, e2);
930 if (sym == &symbol_no)
931 e = expr_alloc_two(E_OR, e1, e2);
932 if (type == E_UNEQUAL)
933 e = expr_alloc_one(E_NOT, e);
934 return e;
935 case E_OR:
936 e1 = expr_trans_compare(e->left.expr, E_EQUAL, sym);
937 e2 = expr_trans_compare(e->right.expr, E_EQUAL, sym);
938 if (sym == &symbol_yes)
939 e = expr_alloc_two(E_OR, e1, e2);
940 if (sym == &symbol_no)
941 e = expr_alloc_two(E_AND, e1, e2);
942 if (type == E_UNEQUAL)
943 e = expr_alloc_one(E_NOT, e);
944 return e;
945 case E_NOT:
946 return expr_trans_compare(e->left.expr, type == E_EQUAL ? E_UNEQUAL : E_EQUAL, sym);
947 case E_UNEQUAL:
948 case E_LTH:
949 case E_LEQ:
950 case E_GTH:
951 case E_GEQ:
952 case E_EQUAL:
953 if (type == E_EQUAL) {
954 if (sym == &symbol_yes)
955 return expr_copy(e);
956 if (sym == &symbol_mod)
957 return expr_alloc_symbol(&symbol_no);
958 if (sym == &symbol_no)
959 return expr_alloc_one(E_NOT, expr_copy(e));
960 } else {
961 if (sym == &symbol_yes)
962 return expr_alloc_one(E_NOT, expr_copy(e));
963 if (sym == &symbol_mod)
964 return expr_alloc_symbol(&symbol_yes);
965 if (sym == &symbol_no)
966 return expr_copy(e);
967 }
968 break;
969 case E_SYMBOL:
970 return expr_alloc_comp(type, e->left.sym, sym);
971 case E_LIST:
972 case E_RANGE:
973 case E_NONE:
974 /* panic */;
975 }
976 return NULL;
977}
978
979enum string_value_kind {
980 k_string,
981 k_signed,
982 k_unsigned,
983 k_invalid
984};
985
986union string_value {
987 unsigned long long u;
988 signed long long s;
989};
990
991static enum string_value_kind expr_parse_string(const char *str,
992 enum symbol_type type,
993 union string_value *val)
994{
995 char *tail;
996 enum string_value_kind kind;
997
998 errno = 0;
999 switch (type) {
1000 case S_BOOLEAN:
1001 case S_TRISTATE:
1002 val->s = !strcmp(str, "n") ? 0 :
1003 !strcmp(str, "m") ? 1 :
1004 !strcmp(str, "y") ? 2 : -1;
1005 return k_signed;
1006 case S_INT:
1007 val->s = strtoll(str, &tail, 10);
1008 kind = k_signed;
1009 break;
1010 case S_HEX:
1011 val->u = strtoull(str, &tail, 16);
1012 kind = k_unsigned;
1013 break;
1014 case S_STRING:
1015 case S_UNKNOWN:
1016 val->s = strtoll(str, &tail, 0);
1017 kind = k_signed;
1018 break;
1019 default:
1020 return k_invalid;
1021 }
1022 return !errno && !*tail && tail > str && isxdigit(tail[-1])
1023 ? kind : k_string;
1024}
1025
1026tristate expr_calc_value(struct expr *e)
1027{
1028 tristate val1, val2;
1029 const char *str1, *str2;
1030 enum string_value_kind k1 = k_string, k2 = k_string;
1031 union string_value lval = {}, rval = {};
1032 int res;
1033
1034 if (!e)
1035 return yes;
1036
1037 switch (e->type) {
1038 case E_SYMBOL:
1039 sym_calc_value(e->left.sym);
1040 return e->left.sym->curr.tri;
1041 case E_AND:
1042 val1 = expr_calc_value(e->left.expr);
1043 val2 = expr_calc_value(e->right.expr);
1044 return EXPR_AND(val1, val2);
1045 case E_OR:
1046 val1 = expr_calc_value(e->left.expr);
1047 val2 = expr_calc_value(e->right.expr);
1048 return EXPR_OR(val1, val2);
1049 case E_NOT:
1050 val1 = expr_calc_value(e->left.expr);
1051 return EXPR_NOT(val1);
1052 case E_EQUAL:
1053 case E_GEQ:
1054 case E_GTH:
1055 case E_LEQ:
1056 case E_LTH:
1057 case E_UNEQUAL:
1058 break;
1059 default:
1060 printf("expr_calc_value: %d?\n", e->type);
1061 return no;
1062 }
1063
1064 sym_calc_value(e->left.sym);
1065 sym_calc_value(e->right.sym);
1066 str1 = sym_get_string_value(e->left.sym);
1067 str2 = sym_get_string_value(e->right.sym);
1068
1069 if (e->left.sym->type != S_STRING || e->right.sym->type != S_STRING) {
1070 k1 = expr_parse_string(str1, e->left.sym->type, &lval);
1071 k2 = expr_parse_string(str2, e->right.sym->type, &rval);
1072 }
1073
1074 if (k1 == k_string || k2 == k_string)
1075 res = strcmp(str1, str2);
1076 else if (k1 == k_invalid || k2 == k_invalid) {
1077 if (e->type != E_EQUAL && e->type != E_UNEQUAL) {
1078 printf("Cannot compare \"%s\" and \"%s\"\n", str1, str2);
1079 return no;
1080 }
1081 res = strcmp(str1, str2);
1082 } else if (k1 == k_unsigned || k2 == k_unsigned)
1083 res = (lval.u > rval.u) - (lval.u < rval.u);
1084 else /* if (k1 == k_signed && k2 == k_signed) */
1085 res = (lval.s > rval.s) - (lval.s < rval.s);
1086
1087 switch(e->type) {
1088 case E_EQUAL:
1089 return res ? no : yes;
1090 case E_GEQ:
1091 return res >= 0 ? yes : no;
1092 case E_GTH:
1093 return res > 0 ? yes : no;
1094 case E_LEQ:
1095 return res <= 0 ? yes : no;
1096 case E_LTH:
1097 return res < 0 ? yes : no;
1098 case E_UNEQUAL:
1099 return res ? yes : no;
1100 default:
1101 printf("expr_calc_value: relation %d?\n", e->type);
1102 return no;
1103 }
1104}
1105
1106static int expr_compare_type(enum expr_type t1, enum expr_type t2)
1107{
1108 if (t1 == t2)
1109 return 0;
1110 switch (t1) {
1111 case E_LEQ:
1112 case E_LTH:
1113 case E_GEQ:
1114 case E_GTH:
1115 if (t2 == E_EQUAL || t2 == E_UNEQUAL)
1116 return 1;
1117 case E_EQUAL:
1118 case E_UNEQUAL:
1119 if (t2 == E_NOT)
1120 return 1;
1121 case E_NOT:
1122 if (t2 == E_AND)
1123 return 1;
1124 case E_AND:
1125 if (t2 == E_OR)
1126 return 1;
1127 case E_OR:
1128 if (t2 == E_LIST)
1129 return 1;
1130 case E_LIST:
1131 if (t2 == 0)
1132 return 1;
1133 default:
1134 return -1;
1135 }
1136 printf("[%dgt%d?]", t1, t2);
1137 return 0;
1138}
1139
1140void expr_print(struct expr *e,
1141 void (*fn)(void *, struct symbol *, const char *),
1142 void *data, int prevtoken)
1143{
1144 if (!e) {
1145 fn(data, NULL, "y");
1146 return;
1147 }
1148
1149 if (expr_compare_type(prevtoken, e->type) > 0)
1150 fn(data, NULL, "(");
1151 switch (e->type) {
1152 case E_SYMBOL:
1153 if (e->left.sym->name)
1154 fn(data, e->left.sym, e->left.sym->name);
1155 else
1156 fn(data, NULL, "<choice>");
1157 break;
1158 case E_NOT:
1159 fn(data, NULL, "!");
1160 expr_print(e->left.expr, fn, data, E_NOT);
1161 break;
1162 case E_EQUAL:
1163 if (e->left.sym->name)
1164 fn(data, e->left.sym, e->left.sym->name);
1165 else
1166 fn(data, NULL, "<choice>");
1167 fn(data, NULL, "=");
1168 fn(data, e->right.sym, e->right.sym->name);
1169 break;
1170 case E_LEQ:
1171 case E_LTH:
1172 if (e->left.sym->name)
1173 fn(data, e->left.sym, e->left.sym->name);
1174 else
1175 fn(data, NULL, "<choice>");
1176 fn(data, NULL, e->type == E_LEQ ? "<=" : "<");
1177 fn(data, e->right.sym, e->right.sym->name);
1178 break;
1179 case E_GEQ:
1180 case E_GTH:
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, e->type == E_GEQ ? ">=" : ">");
1186 fn(data, e->right.sym, e->right.sym->name);
1187 break;
1188 case E_UNEQUAL:
1189 if (e->left.sym->name)
1190 fn(data, e->left.sym, e->left.sym->name);
1191 else
1192 fn(data, NULL, "<choice>");
1193 fn(data, NULL, "!=");
1194 fn(data, e->right.sym, e->right.sym->name);
1195 break;
1196 case E_OR:
1197 expr_print(e->left.expr, fn, data, E_OR);
1198 fn(data, NULL, " || ");
1199 expr_print(e->right.expr, fn, data, E_OR);
1200 break;
1201 case E_AND:
1202 expr_print(e->left.expr, fn, data, E_AND);
1203 fn(data, NULL, " && ");
1204 expr_print(e->right.expr, fn, data, E_AND);
1205 break;
1206 case E_LIST:
1207 fn(data, e->right.sym, e->right.sym->name);
1208 if (e->left.expr) {
1209 fn(data, NULL, " ^ ");
1210 expr_print(e->left.expr, fn, data, E_LIST);
1211 }
1212 break;
1213 case E_RANGE:
1214 fn(data, NULL, "[");
1215 fn(data, e->left.sym, e->left.sym->name);
1216 fn(data, NULL, " ");
1217 fn(data, e->right.sym, e->right.sym->name);
1218 fn(data, NULL, "]");
1219 break;
1220 default:
1221 {
1222 char buf[32];
1223 sprintf(buf, "<unknown type %d>", e->type);
1224 fn(data, NULL, buf);
1225 break;
1226 }
1227 }
1228 if (expr_compare_type(prevtoken, e->type) > 0)
1229 fn(data, NULL, ")");
1230}
1231
1232static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
1233{
1234 xfwrite(str, strlen(str), 1, data);
1235}
1236
1237void expr_fprint(struct expr *e, FILE *out)
1238{
1239 expr_print(e, expr_print_file_helper, out, E_NONE);
1240}
1241
1242static void expr_print_gstr_helper(void *data, struct symbol *sym, const char *str)
1243{
1244 struct gstr *gs = (struct gstr*)data;
1245 const char *sym_str = NULL;
1246
1247 if (sym)
1248 sym_str = sym_get_string_value(sym);
1249
1250 if (gs->max_width) {
1251 unsigned extra_length = strlen(str);
1252 const char *last_cr = strrchr(gs->s, '\n');
1253 unsigned last_line_length;
1254
1255 if (sym_str)
1256 extra_length += 4 + strlen(sym_str);
1257
1258 if (!last_cr)
1259 last_cr = gs->s;
1260
1261 last_line_length = strlen(gs->s) - (last_cr - gs->s);
1262
1263 if ((last_line_length + extra_length) > gs->max_width)
1264 str_append(gs, "\\\n");
1265 }
1266
1267 str_append(gs, str);
1268 if (sym && sym->type != S_UNKNOWN)
1269 str_printf(gs, " [=%s]", sym_str);
1270}
1271
1272void expr_gstr_print(struct expr *e, struct gstr *gs)
1273{
1274 expr_print(e, expr_print_gstr_helper, gs, E_NONE);
1275}
1276
1277/*
1278 * Transform the top level "||" tokens into newlines and prepend each
1279 * line with a minus. This makes expressions much easier to read.
1280 * Suitable for reverse dependency expressions.
1281 */
1282static void expr_print_revdep(struct expr *e,
1283 void (*fn)(void *, struct symbol *, const char *),
1284 void *data, tristate pr_type, const char **title)
1285{
1286 if (e->type == E_OR) {
1287 expr_print_revdep(e->left.expr, fn, data, pr_type, title);
1288 expr_print_revdep(e->right.expr, fn, data, pr_type, title);
1289 } else if (expr_calc_value(e) == pr_type) {
1290 if (*title) {
1291 fn(data, NULL, *title);
1292 *title = NULL;
1293 }
1294
1295 fn(data, NULL, " - ");
1296 expr_print(e, fn, data, E_NONE);
1297 fn(data, NULL, "\n");
1298 }
1299}
1300
1301void expr_gstr_print_revdep(struct expr *e, struct gstr *gs,
1302 tristate pr_type, const char *title)
1303{
1304 expr_print_revdep(e, expr_print_gstr_helper, gs, pr_type, &title);
1305}