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