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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
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}