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db: Avoid dereferencing null pointer
[smatch.git] / smatch_comparison.c
blob269fc65d8295dbe9f658b1d38b631e0e090a609f
1 /*
2 * Copyright (C) 2012 Oracle.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
16 */
17
18 /*
19 * The point here is to store the relationships between two variables.
20 * Ie: y > x.
21 * To do that we create a state with the two variables in alphabetical order:
22 * ->name = "x vs y" and the state would be "<". On the false path the state
23 * would be ">=".
24 *
25 * Part of the trick of it is that if x or y is modified then we need to reset
26 * the state. We need to keep a list of all the states which depend on x and
27 * all the states which depend on y. The link_id code handles this.
28 *
29 */
30
31 #include "smatch.h"
32 #include "smatch_extra.h"
33 #include "smatch_slist.h"
34
35 static int compare_id;
36 static int link_id;
37 static int inc_dec_id;
38 static int inc_dec_link_id;
39
40 /* for handling for loops */
41 STATE(start);
42 STATE(incremented);
43
44 ALLOCATOR(compare_data, "compare data");
45
46 static struct symbol *vsl_to_sym(struct var_sym_list *vsl)
47 {
48 struct var_sym *vs;
49
50 if (!vsl)
51 return NULL;
52 if (ptr_list_size((struct ptr_list *)vsl) != 1)
53 return NULL;
54 vs = first_ptr_list((struct ptr_list *)vsl);
55 return vs->sym;
56 }
57
58 static struct smatch_state *alloc_compare_state(
59 const char *var1, struct var_sym_list *vsl1,
60 int comparison,
61 const char *var2, struct var_sym_list *vsl2)
62 {
63 struct smatch_state *state;
64 struct compare_data *data;
65
66 state = __alloc_smatch_state(0);
67 state->name = alloc_sname(show_special(comparison));
68 data = __alloc_compare_data(0);
69 data->var1 = alloc_sname(var1);
70 data->vsl1 = clone_var_sym_list(vsl1);
71 data->comparison = comparison;
72 data->var2 = alloc_sname(var2);
73 data->vsl2 = clone_var_sym_list(vsl2);
74 state->data = data;
75 return state;
76 }
77
78 static int state_to_comparison(struct smatch_state *state)
79 {
80 if (!state || !state->data)
81 return 0;
82 return ((struct compare_data *)state->data)->comparison;
83 }
84
85 /*
86 * flip_comparison() reverses the op left and right. So "x >= y" becomes "y <= x".
87 */
88 int flip_comparison(int op)
89 {
90 switch (op) {
91 case 0:
92 return 0;
93 case '<':
94 return '>';
95 case SPECIAL_UNSIGNED_LT:
96 return SPECIAL_UNSIGNED_GT;
97 case SPECIAL_LTE:
98 return SPECIAL_GTE;
99 case SPECIAL_UNSIGNED_LTE:
100 return SPECIAL_UNSIGNED_GTE;
101 case SPECIAL_EQUAL:
102 return SPECIAL_EQUAL;
103 case SPECIAL_NOTEQUAL:
104 return SPECIAL_NOTEQUAL;
105 case SPECIAL_GTE:
106 return SPECIAL_LTE;
107 case SPECIAL_UNSIGNED_GTE:
108 return SPECIAL_UNSIGNED_LTE;
109 case '>':
110 return '<';
111 case SPECIAL_UNSIGNED_GT:
112 return SPECIAL_UNSIGNED_LT;
113 default:
114 sm_msg("internal smatch bug. unhandled comparison %d", op);
115 return op;
116 }
117 }
118
119 int negate_comparison(int op)
120 {
121 switch (op) {
122 case 0:
123 return 0;
124 case '<':
125 return SPECIAL_GTE;
126 case SPECIAL_UNSIGNED_LT:
127 return SPECIAL_UNSIGNED_GTE;
128 case SPECIAL_LTE:
129 return '>';
130 case SPECIAL_UNSIGNED_LTE:
131 return SPECIAL_UNSIGNED_GT;
132 case SPECIAL_EQUAL:
133 return SPECIAL_NOTEQUAL;
134 case SPECIAL_NOTEQUAL:
135 return SPECIAL_EQUAL;
136 case SPECIAL_GTE:
137 return '<';
138 case SPECIAL_UNSIGNED_GTE:
139 return SPECIAL_UNSIGNED_LT;
140 case '>':
141 return SPECIAL_LTE;
142 case SPECIAL_UNSIGNED_GT:
143 return SPECIAL_UNSIGNED_LTE;
144 default:
145 sm_msg("internal smatch bug. unhandled comparison %d", op);
146 return op;
147 }
148 }
149
150 static int rl_comparison(struct range_list *left_rl, struct range_list *right_rl)
151 {
152 sval_t left_min, left_max, right_min, right_max;
153
154 if (!left_rl || !right_rl)
155 return 0;
156
157 left_min = rl_min(left_rl);
158 left_max = rl_max(left_rl);
159 right_min = rl_min(right_rl);
160 right_max = rl_max(right_rl);
161
162 if (left_min.value == left_max.value &&
163 right_min.value == right_max.value &&
164 left_min.value == right_min.value)
165 return SPECIAL_EQUAL;
166
167 if (sval_cmp(left_max, right_min) < 0)
168 return '<';
169 if (sval_cmp(left_max, right_min) == 0)
170 return SPECIAL_LTE;
171 if (sval_cmp(left_min, right_max) > 0)
172 return '>';
173 if (sval_cmp(left_min, right_max) == 0)
174 return SPECIAL_GTE;
175
176 return 0;
177 }
178
179 static struct range_list *get_orig_rl(struct var_sym_list *vsl)
180 {
181 struct symbol *sym;
182 struct smatch_state *state;
183
184 if (!vsl)
185 return NULL;
186 sym = vsl_to_sym(vsl);
187 if (!sym || !sym->ident)
188 return NULL;
189 state = get_orig_estate(sym->ident->name, sym);
190 return estate_rl(state);
191 }
192
193 static struct smatch_state *unmatched_comparison(struct sm_state *sm)
194 {
195 struct compare_data *data = sm->state->data;
196 struct range_list *left_rl, *right_rl;
197 int op;
198
199 if (!data)
200 return &undefined;
201
202 if (strstr(data->var1, " orig"))
203 left_rl = get_orig_rl(data->vsl1);
204 else if (!get_implied_rl_var_sym(data->var1, vsl_to_sym(data->vsl1), &left_rl))
205 return &undefined;
206 if (strstr(data->var2, " orig"))
207 right_rl = get_orig_rl(data->vsl2);
208 else if (!get_implied_rl_var_sym(data->var2, vsl_to_sym(data->vsl2), &right_rl))
209 return &undefined;
210
211
212 op = rl_comparison(left_rl, right_rl);
213 if (op)
214 return alloc_compare_state(data->var1, data->vsl1, op, data->var2, data->vsl2);
215
216 return &undefined;
217 }
218
219 /* remove_unsigned_from_comparison() is obviously a hack. */
220 static int remove_unsigned_from_comparison(int op)
221 {
222 switch (op) {
223 case SPECIAL_UNSIGNED_LT:
224 return '<';
225 case SPECIAL_UNSIGNED_LTE:
226 return SPECIAL_LTE;
227 case SPECIAL_UNSIGNED_GTE:
228 return SPECIAL_GTE;
229 case SPECIAL_UNSIGNED_GT:
230 return '>';
231 default:
232 return op;
233 }
234 }
235
236 /*
237 * This is for when you merge states "a < b" and "a == b", the result is that
238 * we can say for sure, "a <= b" after the merge.
239 */
240 static int merge_comparisons(int one, int two)
241 {
242 int LT, EQ, GT;
243
244 one = remove_unsigned_from_comparison(one);
245 two = remove_unsigned_from_comparison(two);
246
247 if (one == two)
248 return one;
249
250 LT = EQ = GT = 0;
251
252 switch (one) {
253 case '<':
254 LT = 1;
255 break;
256 case SPECIAL_LTE:
257 LT = 1;
258 EQ = 1;
259 break;
260 case SPECIAL_EQUAL:
261 EQ = 1;
262 break;
263 case SPECIAL_GTE:
264 GT = 1;
265 EQ = 1;
266 break;
267 case '>':
268 GT = 1;
269 }
270
271 switch (two) {
272 case '<':
273 LT = 1;
274 break;
275 case SPECIAL_LTE:
276 LT = 1;
277 EQ = 1;
278 break;
279 case SPECIAL_EQUAL:
280 EQ = 1;
281 break;
282 case SPECIAL_GTE:
283 GT = 1;
284 EQ = 1;
285 break;
286 case '>':
287 GT = 1;
288 }
289
290 if (LT && EQ && GT)
291 return 0;
292 if (LT && EQ)
293 return SPECIAL_LTE;
294 if (LT && GT)
295 return SPECIAL_NOTEQUAL;
296 if (LT)
297 return '<';
298 if (EQ && GT)
299 return SPECIAL_GTE;
300 if (GT)
301 return '>';
302 return 0;
303 }
304
305 /*
306 * This is for if you have "a < b" and "b <= c". Or in other words,
307 * "a < b <= c". You would call this like get_combined_comparison('<', '<=').
308 * The return comparison would be '<'.
309 *
310 * This function is different from merge_comparisons(), for example:
311 * merge_comparison('<', '==') returns '<='
312 * get_combined_comparison('<', '==') returns '<'
313 */
314 static int combine_comparisons(int left_compare, int right_compare)
315 {
316 int LT, EQ, GT;
317
318 left_compare = remove_unsigned_from_comparison(left_compare);
319 right_compare = remove_unsigned_from_comparison(right_compare);
320
321 LT = EQ = GT = 0;
322
323 switch (left_compare) {
324 case '<':
325 LT++;
326 break;
327 case SPECIAL_LTE:
328 LT++;
329 EQ++;
330 break;
331 case SPECIAL_EQUAL:
332 return right_compare;
333 case SPECIAL_GTE:
334 GT++;
335 EQ++;
336 break;
337 case '>':
338 GT++;
339 }
340
341 switch (right_compare) {
342 case '<':
343 LT++;
344 break;
345 case SPECIAL_LTE:
346 LT++;
347 EQ++;
348 break;
349 case SPECIAL_EQUAL:
350 return left_compare;
351 case SPECIAL_GTE:
352 GT++;
353 EQ++;
354 break;
355 case '>':
356 GT++;
357 }
358
359 if (LT == 2) {
360 if (EQ == 2)
361 return SPECIAL_LTE;
362 return '<';
363 }
364
365 if (GT == 2) {
366 if (EQ == 2)
367 return SPECIAL_GTE;
368 return '>';
369 }
370 return 0;
371 }
372
373 static int filter_comparison(int orig, int op)
374 {
375 if (orig == op)
376 return orig;
377
378 switch (orig) {
379 case 0:
380 return op;
381 case '<':
382 switch (op) {
383 case '<':
384 case SPECIAL_LTE:
385 case SPECIAL_NOTEQUAL:
386 return '<';
387 }
388 return 0;
389 case SPECIAL_LTE:
390 switch (op) {
391 case '<':
392 case SPECIAL_LTE:
393 case SPECIAL_EQUAL:
394 return op;
395 case SPECIAL_NOTEQUAL:
396 return '<';
397 }
398 return 0;
399 case SPECIAL_EQUAL:
400 switch (op) {
401 case SPECIAL_LTE:
402 case SPECIAL_EQUAL:
403 case SPECIAL_GTE:
404 case SPECIAL_UNSIGNED_LTE:
405 case SPECIAL_UNSIGNED_GTE:
406 return SPECIAL_EQUAL;
407 }
408 return 0;
409 case SPECIAL_NOTEQUAL:
410 switch (op) {
411 case '<':
412 case SPECIAL_LTE:
413 return '<';
414 case SPECIAL_UNSIGNED_LT:
415 case SPECIAL_UNSIGNED_LTE:
416 return SPECIAL_UNSIGNED_LT;
417 case SPECIAL_NOTEQUAL:
418 return op;
419 case '>':
420 case SPECIAL_GTE:
421 return '>';
422 case SPECIAL_UNSIGNED_GT:
423 case SPECIAL_UNSIGNED_GTE:
424 return SPECIAL_UNSIGNED_GT;
425 }
426 return 0;
427 case SPECIAL_GTE:
428 switch (op) {
429 case SPECIAL_LTE:
430 return SPECIAL_EQUAL;
431 case '>':
432 case SPECIAL_GTE:
433 case SPECIAL_EQUAL:
434 return op;
435 case SPECIAL_NOTEQUAL:
436 return '>';
437 }
438 return 0;
439 case '>':
440 switch (op) {
441 case '>':
442 case SPECIAL_GTE:
443 case SPECIAL_NOTEQUAL:
444 return '>';
445 }
446 return 0;
447 case SPECIAL_UNSIGNED_LT:
448 switch (op) {
449 case SPECIAL_UNSIGNED_LT:
450 case SPECIAL_UNSIGNED_LTE:
451 case SPECIAL_NOTEQUAL:
452 return SPECIAL_UNSIGNED_LT;
453 }
454 return 0;
455 case SPECIAL_UNSIGNED_LTE:
456 switch (op) {
457 case SPECIAL_UNSIGNED_LT:
458 case SPECIAL_UNSIGNED_LTE:
459 case SPECIAL_EQUAL:
460 return op;
461 case SPECIAL_NOTEQUAL:
462 return SPECIAL_UNSIGNED_LT;
463 case SPECIAL_UNSIGNED_GTE:
464 return SPECIAL_EQUAL;
465 }
466 return 0;
467 case SPECIAL_UNSIGNED_GTE:
468 switch (op) {
469 case SPECIAL_UNSIGNED_LTE:
470 return SPECIAL_EQUAL;
471 case SPECIAL_NOTEQUAL:
472 return SPECIAL_UNSIGNED_GT;
473 case SPECIAL_EQUAL:
474 case SPECIAL_UNSIGNED_GTE:
475 case SPECIAL_UNSIGNED_GT:
476 return op;
477 }
478 return 0;
479 case SPECIAL_UNSIGNED_GT:
480 switch (op) {
481 case SPECIAL_UNSIGNED_GT:
482 case SPECIAL_UNSIGNED_GTE:
483 case SPECIAL_NOTEQUAL:
484 return SPECIAL_UNSIGNED_GT;
485 }
486 return 0;
487 }
488 return 0;
489 }
490
491 static struct smatch_state *merge_compare_states(struct smatch_state *s1, struct smatch_state *s2)
492 {
493 struct compare_data *data = s1->data;
494 int op;
495
496 op = merge_comparisons(state_to_comparison(s1), state_to_comparison(s2));
497 if (op)
498 return alloc_compare_state(data->var1, data->vsl1, op, data->var2, data->vsl2);
499 return &undefined;
500 }
501
502 static struct smatch_state *alloc_link_state(struct string_list *links)
503 {
504 struct smatch_state *state;
505 static char buf[256];
506 char *tmp;
507 int i;
508
509 state = __alloc_smatch_state(0);
510
511 i = 0;
512 FOR_EACH_PTR(links, tmp) {
513 if (!i++) {
514 snprintf(buf, sizeof(buf), "%s", tmp);
515 } else {
516 append(buf, ", ", sizeof(buf));
517 append(buf, tmp, sizeof(buf));
518 }
519 } END_FOR_EACH_PTR(tmp);
520
521 state->name = alloc_sname(buf);
522 state->data = links;
523 return state;
524 }
525
526 static void save_start_states(struct statement *stmt)
527 {
528 struct symbol *param;
529 char orig[64];
530 char state_name[128];
531 struct smatch_state *state;
532 struct string_list *links;
533 char *link;
534
535 FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, param) {
536 struct var_sym_list *vsl1 = NULL;
537 struct var_sym_list *vsl2 = NULL;
538
539 if (!param->ident)
540 continue;
541 snprintf(orig, sizeof(orig), "%s orig", param->ident->name);
542 snprintf(state_name, sizeof(state_name), "%s vs %s", param->ident->name, orig);
543 add_var_sym(&vsl1, param->ident->name, param);
544 add_var_sym(&vsl2, orig, param);
545 state = alloc_compare_state(param->ident->name, vsl1, SPECIAL_EQUAL, alloc_sname(orig), vsl2);
546 set_state(compare_id, state_name, NULL, state);
547
548 link = alloc_sname(state_name);
549 links = NULL;
550 insert_string(&links, link);
551 state = alloc_link_state(links);
552 set_state(link_id, param->ident->name, param, state);
553 } END_FOR_EACH_PTR(param);
554 }
555
556 static struct smatch_state *merge_links(struct smatch_state *s1, struct smatch_state *s2)
557 {
558 struct smatch_state *ret;
559 struct string_list *links;
560
561 links = combine_string_lists(s1->data, s2->data);
562 ret = alloc_link_state(links);
563 return ret;
564 }
565
566 static void save_link_var_sym(const char *var, struct symbol *sym, const char *link)
567 {
568 struct smatch_state *old_state, *new_state;
569 struct string_list *links;
570 char *new;
571
572 old_state = get_state(link_id, var, sym);
573 if (old_state)
574 links = clone_str_list(old_state->data);
575 else
576 links = NULL;
577
578 new = alloc_sname(link);
579 insert_string(&links, new);
580
581 new_state = alloc_link_state(links);
582 set_state(link_id, var, sym, new_state);
583 }
584
585 static void match_inc(struct sm_state *sm)
586 {
587 struct string_list *links;
588 struct smatch_state *state;
589 char *tmp;
590
591 links = sm->state->data;
592
593 FOR_EACH_PTR(links, tmp) {
594 state = get_state(compare_id, tmp, NULL);
595
596 switch (state_to_comparison(state)) {
597 case SPECIAL_EQUAL:
598 case SPECIAL_GTE:
599 case SPECIAL_UNSIGNED_GTE:
600 case '>':
601 case SPECIAL_UNSIGNED_GT: {
602 struct compare_data *data = state->data;
603 struct smatch_state *new;
604
605 new = alloc_compare_state(data->var1, data->vsl1, '>', data->var2, data->vsl2);
606 set_state(compare_id, tmp, NULL, new);
607 break;
608 }
609 default:
610 set_state(compare_id, tmp, NULL, &undefined);
611 }
612 } END_FOR_EACH_PTR(tmp);
613 }
614
615 static void match_dec(struct sm_state *sm)
616 {
617 struct string_list *links;
618 struct smatch_state *state;
619 char *tmp;
620
621 links = sm->state->data;
622
623 FOR_EACH_PTR(links, tmp) {
624 state = get_state(compare_id, tmp, NULL);
625
626 switch (state_to_comparison(state)) {
627 case SPECIAL_EQUAL:
628 case SPECIAL_LTE:
629 case SPECIAL_UNSIGNED_LTE:
630 case '<':
631 case SPECIAL_UNSIGNED_LT: {
632 struct compare_data *data = state->data;
633 struct smatch_state *new;
634
635 new = alloc_compare_state(data->var1, data->vsl1, '<', data->var2, data->vsl2);
636 set_state(compare_id, tmp, NULL, new);
637 break;
638 }
639 default:
640 set_state(compare_id, tmp, NULL, &undefined);
641 }
642 } END_FOR_EACH_PTR(tmp);
643 }
644
645 static int match_inc_dec(struct sm_state *sm, struct expression *mod_expr)
646 {
647 if (!mod_expr)
648 return 0;
649 if (mod_expr->type != EXPR_PREOP && mod_expr->type != EXPR_POSTOP)
650 return 0;
651
652 if (mod_expr->op == SPECIAL_INCREMENT) {
653 match_inc(sm);
654 return 1;
655 }
656 if (mod_expr->op == SPECIAL_DECREMENT) {
657 match_dec(sm);
658 return 1;
659 }
660 return 0;
661 }
662
663 static void match_modify(struct sm_state *sm, struct expression *mod_expr)
664 {
665 struct string_list *links;
666 char *tmp;
667
668 /* Huh??? This needs a comment! */
669 if (match_inc_dec(sm, mod_expr))
670 return;
671
672 links = sm->state->data;
673
674 FOR_EACH_PTR(links, tmp) {
675 set_state(compare_id, tmp, NULL, &undefined);
676 } END_FOR_EACH_PTR(tmp);
677 set_state(link_id, sm->name, sm->sym, &undefined);
678 }
679
680 static char *chunk_to_var_sym(struct expression *expr, struct symbol **sym)
681 {
682 char *name, *left_name, *right_name;
683 struct symbol *tmp;
684 char buf[128];
685
686 expr = strip_expr(expr);
687 if (!expr)
688 return NULL;
689 if (sym)
690 *sym = NULL;
691
692 if (expr->type == EXPR_PREOP &&
693 (expr->op == SPECIAL_INCREMENT ||
694 expr->op == SPECIAL_DECREMENT))
695 expr = strip_expr(expr->unop);
696
697 name = expr_to_var_sym(expr, &tmp);
698 if (name && tmp) {
699 if (sym)
700 *sym = tmp;
701 return name;
702 }
703 if (name)
704 free_string(name);
705
706 if (expr->type != EXPR_BINOP)
707 return NULL;
708 if (expr->op != '-' && expr->op != '+')
709 return NULL;
710
711 left_name = expr_to_var(expr->left);
712 if (!left_name)
713 return NULL;
714 right_name = expr_to_var(expr->right);
715 if (!right_name) {
716 free_string(left_name);
717 return NULL;
718 }
719 snprintf(buf, sizeof(buf), "%s %s %s", left_name, show_special(expr->op), right_name);
720 free_string(left_name);
721 free_string(right_name);
722 return alloc_string(buf);
723 }
724
725 static char *chunk_to_var(struct expression *expr)
726 {
727 return chunk_to_var_sym(expr, NULL);
728 }
729
730 static void save_link(struct expression *expr, char *link)
731 {
732 char *var;
733 struct symbol *sym;
734
735 expr = strip_expr(expr);
736 if (expr->type == EXPR_BINOP) {
737 char *chunk;
738
739 chunk = chunk_to_var(expr);
740 if (!chunk)
741 return;
742
743 save_link(expr->left, link);
744 save_link(expr->right, link);
745 save_link_var_sym(chunk, NULL, link);
746 return;
747 }
748
749 var = expr_to_var_sym(expr, &sym);
750 if (!var || !sym)
751 goto done;
752
753 save_link_var_sym(var, sym, link);
754 done:
755 free_string(var);
756 }
757
758 static int get_orig_comparison(struct stree *pre_stree, const char *left, const char *right)
759 {
760 struct smatch_state *state;
761 struct compare_data *data;
762 int flip = 0;
763 char state_name[256];
764
765 if (strcmp(left, right) > 0) {
766 const char *tmp = right;
767
768 flip = 1;
769 right = left;
770 left = tmp;
771 }
772
773 snprintf(state_name, sizeof(state_name), "%s vs %s", left, right);
774 state = get_state_stree(pre_stree, compare_id, state_name, NULL);
775 if (!state || !state->data)
776 return 0;
777 data = state->data;
778 if (flip)
779 return flip_comparison(data->comparison);
780 return data->comparison;
781
782 }
783
784 /*
785 * The idea here is that we take a comparison "a < b" and then we look at all
786 * the things which "b" is compared against "b < c" and we say that that implies
787 * a relationship "a < c".
788 *
789 * The names here about because the comparisons are organized like this
790 * "a < b < c".
791 *
792 */
793 static void update_tf_links(struct stree *pre_stree,
794 const char *left_var, struct var_sym_list *left_vsl,
795 int left_comparison, int left_false_comparison,
796 const char *mid_var, struct var_sym_list *mid_vsl,
797 struct string_list *links)
798 {
799 struct smatch_state *state;
800 struct smatch_state *true_state, *false_state;
801 struct compare_data *data;
802 const char *right_var;
803 struct var_sym_list *right_vsl;
804 int orig_comparison;
805 int right_comparison;
806 int true_comparison;
807 int false_comparison;
808 char *tmp;
809 char state_name[256];
810 struct var_sym *vs;
811
812 FOR_EACH_PTR(links, tmp) {
813 state = get_state_stree(pre_stree, compare_id, tmp, NULL);
814 if (!state || !state->data)
815 continue;
816 data = state->data;
817 right_comparison = data->comparison;
818 right_var = data->var2;
819 right_vsl = data->vsl2;
820 if (strcmp(mid_var, right_var) == 0) {
821 right_var = data->var1;
822 right_vsl = data->vsl1;
823 right_comparison = flip_comparison(right_comparison);
824 }
825 if (strcmp(left_var, right_var) == 0)
826 continue;
827
828 orig_comparison = get_orig_comparison(pre_stree, left_var, right_var);
829
830 true_comparison = combine_comparisons(left_comparison, right_comparison);
831 false_comparison = combine_comparisons(left_false_comparison, right_comparison);
832
833 true_comparison = filter_comparison(orig_comparison, true_comparison);
834 false_comparison = filter_comparison(orig_comparison, false_comparison);
835
836 if (strcmp(left_var, right_var) > 0) {
837 const char *tmp_var = left_var;
838 struct var_sym_list *tmp_vsl = left_vsl;
839
840 left_var = right_var;
841 left_vsl = right_vsl;
842 right_var = tmp_var;
843 right_vsl = tmp_vsl;
844 true_comparison = flip_comparison(true_comparison);
845 false_comparison = flip_comparison(false_comparison);
846 }
847
848 if (!true_comparison && !false_comparison)
849 continue;
850
851 if (true_comparison)
852 true_state = alloc_compare_state(left_var, left_vsl, true_comparison, right_var, right_vsl);
853 else
854 true_state = NULL;
855 if (false_comparison)
856 false_state = alloc_compare_state(left_var, left_vsl, false_comparison, right_var, right_vsl);
857 else
858 false_state = NULL;
859
860 snprintf(state_name, sizeof(state_name), "%s vs %s", left_var, right_var);
861 set_true_false_states(compare_id, state_name, NULL, true_state, false_state);
862 FOR_EACH_PTR(left_vsl, vs) {
863 save_link_var_sym(vs->var, vs->sym, state_name);
864 } END_FOR_EACH_PTR(vs);
865 FOR_EACH_PTR(right_vsl, vs) {
866 save_link_var_sym(vs->var, vs->sym, state_name);
867 } END_FOR_EACH_PTR(vs);
868 if (!vsl_to_sym(left_vsl))
869 save_link_var_sym(left_var, NULL, state_name);
870 if (!vsl_to_sym(right_vsl))
871 save_link_var_sym(right_var, NULL, state_name);
872 } END_FOR_EACH_PTR(tmp);
873 }
874
875 static void update_tf_data(struct stree *pre_stree,
876 const char *left_name, struct var_sym_list *left_vsl,
877 const char *right_name, struct var_sym_list *right_vsl,
878 int true_comparison, int false_comparison)
879 {
880 struct smatch_state *state;
881
882 state = get_state_stree(pre_stree, link_id, right_name, vsl_to_sym(right_vsl));
883 if (state)
884 update_tf_links(pre_stree, left_name, left_vsl, true_comparison, false_comparison, right_name, right_vsl, state->data);
885
886 state = get_state_stree(pre_stree, link_id, left_name, vsl_to_sym(left_vsl));
887 if (state)
888 update_tf_links(pre_stree, right_name, right_vsl, flip_comparison(true_comparison), flip_comparison(false_comparison), left_name, left_vsl, state->data);
889 }
890
891 static void iter_modify(struct sm_state *sm, struct expression *mod_expr)
892 {
893 if (sm->state != &start ||
894 !mod_expr ||
895 (mod_expr->type != EXPR_PREOP && mod_expr->type != EXPR_POSTOP) ||
896 mod_expr->op != SPECIAL_INCREMENT)
897 set_state(inc_dec_id, sm->name, sm->sym, &undefined);
898 else
899 set_state(inc_dec_id, sm->name, sm->sym, &incremented);
900 }
901
902 static void handle_for_loops(struct expression *expr, char *state_name, struct smatch_state *false_state)
903 {
904 sval_t sval;
905 char *iter_name, *cap_name;
906 struct symbol *iter_sym, *cap_sym;
907 struct compare_data *data;
908
909 if (expr->op != '<' && expr->op != SPECIAL_UNSIGNED_LT)
910 return;
911
912 if (!__cur_stmt || !__prev_stmt)
913 return;
914 if (__cur_stmt->type != STMT_ITERATOR)
915 return;
916 if (__cur_stmt->iterator_pre_condition != expr)
917 return;
918
919 /* literals are handled in smatch_extra.c */
920 if (get_value(expr->right, &sval))
921 return;
922
923 /* First time checking the condition */
924 if (__prev_stmt == __cur_stmt->iterator_pre_statement) {
925 if (!get_implied_value(expr->left, &sval) ||
926 sval.value != 0)
927 return;
928
929 iter_name = expr_to_var_sym(expr->left, &iter_sym);
930 cap_name = expr_to_var_sym(expr->right, &cap_sym);
931 if (!iter_name || !cap_name || !iter_sym || !cap_sym) {
932 free_string(iter_name);
933 free_string(cap_name);
934 return;
935 }
936
937 set_state(inc_dec_id, iter_name, iter_sym, &start);
938 store_link(inc_dec_link_id, cap_name, cap_sym, iter_name, iter_sym);
939
940 free_string(iter_name);
941 free_string(cap_name);
942 return;
943 }
944
945 /* Second time checking the condtion */
946 if (__prev_stmt != __cur_stmt->iterator_post_statement)
947 return;
948
949 if (get_state_expr(inc_dec_id, expr->left) != &incremented)
950 return;
951
952 data = false_state->data;
953 false_state = alloc_compare_state(data->var1, data->vsl1, SPECIAL_EQUAL, data->var2, data->vsl2);
954
955 set_true_false_states(compare_id, state_name, NULL, NULL, false_state);
956 }
957
958 static void match_compare(struct expression *expr)
959 {
960 char *left = NULL;
961 char *right = NULL;
962 struct symbol *left_sym, *right_sym;
963 struct var_sym_list *left_vsl, *right_vsl;
964 int op, false_op;
965 int orig_comparison;
966 struct smatch_state *true_state, *false_state;
967 char state_name[256];
968 struct stree *pre_stree;
969 sval_t sval;
970
971 if (expr->type != EXPR_COMPARE)
972 return;
973
974 op = expr->op;
975 false_op = negate_comparison(op);
976
977 if (op == SPECIAL_UNSIGNED_LT &&
978 get_implied_value(expr->left, &sval) &&
979 sval.value == 0)
980 false_op = SPECIAL_EQUAL;
981
982 if (op == SPECIAL_UNSIGNED_GT &&
983 get_implied_value(expr->right, &sval) &&
984 sval.value == 0)
985 false_op = SPECIAL_EQUAL;
986
987 left = chunk_to_var_sym(expr->left, &left_sym);
988 if (!left)
989 goto free;
990 left_vsl = expr_to_vsl(expr->left);
991 right = chunk_to_var_sym(expr->right, &right_sym);
992 if (!right)
993 goto free;
994 right_vsl = expr_to_vsl(expr->right);
995
996 if (strcmp(left, right) > 0) {
997 struct symbol *tmp_sym = left_sym;
998 char *tmp_name = left;
999 struct var_sym_list *tmp_vsl = left_vsl;
1000
1001 left = right;
1002 left_sym = right_sym;
1003 left_vsl = right_vsl;
1004 right = tmp_name;
1005 right_sym = tmp_sym;
1006 right_vsl = tmp_vsl;
1007 op = flip_comparison(op);
1008 false_op = flip_comparison(false_op);
1009 }
1010
1011 orig_comparison = get_comparison_strings(left, right);
1012 op = filter_comparison(orig_comparison, op);
1013 false_op = filter_comparison(orig_comparison, false_op);
1014
1015 snprintf(state_name, sizeof(state_name), "%s vs %s", left, right);
1016 true_state = alloc_compare_state(left, left_vsl, op, right, right_vsl);
1017 false_state = alloc_compare_state(left, left_vsl, false_op, right, right_vsl);
1018
1019 pre_stree = clone_stree(__get_cur_stree());
1020 update_tf_data(pre_stree, left, left_vsl, right, right_vsl, op, false_op);
1021 free_stree(&pre_stree);
1022
1023 set_true_false_states(compare_id, state_name, NULL, true_state, false_state);
1024 save_link(expr->left, state_name);
1025 save_link(expr->right, state_name);
1026
1027 handle_for_loops(expr, state_name, false_state);
1028 free:
1029 free_string(left);
1030 free_string(right);
1031 }
1032
1033 static void add_comparison_var_sym(const char *left_name,
1034 struct var_sym_list *left_vsl,
1035 int comparison,
1036 const char *right_name, struct var_sym_list *right_vsl)
1037 {
1038 struct smatch_state *state;
1039 struct var_sym *vs;
1040 char state_name[256];
1041
1042 if (strcmp(left_name, right_name) > 0) {
1043 const char *tmp_name = left_name;
1044 struct var_sym_list *tmp_vsl = left_vsl;
1045
1046 left_name = right_name;
1047 left_vsl = right_vsl;
1048 right_name = tmp_name;
1049 right_vsl = tmp_vsl;
1050 comparison = flip_comparison(comparison);
1051 }
1052 snprintf(state_name, sizeof(state_name), "%s vs %s", left_name, right_name);
1053 state = alloc_compare_state(left_name, left_vsl, comparison, right_name, right_vsl);
1054
1055 set_state(compare_id, state_name, NULL, state);
1056
1057 FOR_EACH_PTR(left_vsl, vs) {
1058 save_link_var_sym(vs->var, vs->sym, state_name);
1059 } END_FOR_EACH_PTR(vs);
1060 FOR_EACH_PTR(right_vsl, vs) {
1061 save_link_var_sym(vs->var, vs->sym, state_name);
1062 } END_FOR_EACH_PTR(vs);
1063 }
1064
1065 static void add_comparison(struct expression *left, int comparison, struct expression *right)
1066 {
1067 char *left_name = NULL;
1068 char *right_name = NULL;
1069 struct symbol *left_sym, *right_sym;
1070 struct var_sym_list *left_vsl, *right_vsl;
1071 struct smatch_state *state;
1072 char state_name[256];
1073
1074 left_name = chunk_to_var_sym(left, &left_sym);
1075 if (!left_name)
1076 goto free;
1077 left_vsl = expr_to_vsl(left);
1078 right_name = chunk_to_var_sym(right, &right_sym);
1079 if (!right_name)
1080 goto free;
1081 right_vsl = expr_to_vsl(right);
1082
1083 if (strcmp(left_name, right_name) > 0) {
1084 struct symbol *tmp_sym = left_sym;
1085 char *tmp_name = left_name;
1086 struct var_sym_list *tmp_vsl = left_vsl;
1087
1088 left_name = right_name;
1089 left_sym = right_sym;
1090 left_vsl = right_vsl;
1091 right_name = tmp_name;
1092 right_sym = tmp_sym;
1093 right_vsl = tmp_vsl;
1094 comparison = flip_comparison(comparison);
1095 }
1096 snprintf(state_name, sizeof(state_name), "%s vs %s", left_name, right_name);
1097 state = alloc_compare_state(left_name, left_vsl, comparison, right_name, right_vsl);
1098
1099 set_state(compare_id, state_name, NULL, state);
1100 save_link(left, state_name);
1101 save_link(right, state_name);
1102
1103 free:
1104 free_string(left_name);
1105 free_string(right_name);
1106 }
1107
1108 static void match_assign_add(struct expression *expr)
1109 {
1110 struct expression *right;
1111 struct expression *r_left, *r_right;
1112 sval_t left_tmp, right_tmp;
1113
1114 right = strip_expr(expr->right);
1115 r_left = strip_expr(right->left);
1116 r_right = strip_expr(right->right);
1117
1118 get_absolute_min(r_left, &left_tmp);
1119 get_absolute_min(r_right, &right_tmp);
1120
1121 if (left_tmp.value > 0)
1122 add_comparison(expr->left, '>', r_right);
1123 else if (left_tmp.value == 0)
1124 add_comparison(expr->left, SPECIAL_GTE, r_right);
1125
1126 if (right_tmp.value > 0)
1127 add_comparison(expr->left, '>', r_left);
1128 else if (right_tmp.value == 0)
1129 add_comparison(expr->left, SPECIAL_GTE, r_left);
1130 }
1131
1132 static void match_assign_sub(struct expression *expr)
1133 {
1134 struct expression *right;
1135 struct expression *r_left, *r_right;
1136 int comparison;
1137 sval_t min;
1138
1139 right = strip_expr(expr->right);
1140 r_left = strip_expr(right->left);
1141 r_right = strip_expr(right->right);
1142
1143 if (get_absolute_min(r_right, &min) && sval_is_negative(min))
1144 return;
1145
1146 comparison = get_comparison(r_left, r_right);
1147
1148 switch (comparison) {
1149 case '>':
1150 case SPECIAL_GTE:
1151 if (implied_not_equal(r_right, 0))
1152 add_comparison(expr->left, '>', r_left);
1153 else
1154 add_comparison(expr->left, SPECIAL_GTE, r_left);
1155 return;
1156 }
1157 }
1158
1159 static void match_assign_divide(struct expression *expr)
1160 {
1161 struct expression *right;
1162 struct expression *r_left, *r_right;
1163 sval_t min;
1164
1165 right = strip_expr(expr->right);
1166 r_left = strip_expr(right->left);
1167 r_right = strip_expr(right->right);
1168 if (!get_implied_min(r_right, &min) || min.value <= 1)
1169 return;
1170
1171 add_comparison(expr->left, '<', r_left);
1172 }
1173
1174 static void match_binop_assign(struct expression *expr)
1175 {
1176 struct expression *right;
1177
1178 right = strip_expr(expr->right);
1179 if (right->op == '+')
1180 match_assign_add(expr);
1181 if (right->op == '-')
1182 match_assign_sub(expr);
1183 if (right->op == '/')
1184 match_assign_divide(expr);
1185 }
1186
1187 static void copy_comparisons(struct expression *left, struct expression *right)
1188 {
1189 struct string_list *links;
1190 struct smatch_state *state;
1191 struct compare_data *data;
1192 struct symbol *left_sym, *right_sym;
1193 char *left_var = NULL;
1194 char *right_var = NULL;
1195 struct var_sym_list *left_vsl;
1196 const char *var;
1197 struct var_sym_list *vsl;
1198 int comparison;
1199 char *tmp;
1200
1201 left_var = chunk_to_var_sym(left, &left_sym);
1202 if (!left_var)
1203 goto done;
1204 left_vsl = expr_to_vsl(left);
1205 right_var = chunk_to_var_sym(right, &right_sym);
1206 if (!right_var)
1207 goto done;
1208
1209 state = get_state(link_id, right_var, right_sym);
1210 if (!state)
1211 return;
1212 links = state->data;
1213
1214 FOR_EACH_PTR(links, tmp) {
1215 state = get_state(compare_id, tmp, NULL);
1216 if (!state || !state->data)
1217 continue;
1218 data = state->data;
1219 comparison = data->comparison;
1220 var = data->var2;
1221 vsl = data->vsl2;
1222 if (strcmp(var, right_var) == 0) {
1223 var = data->var1;
1224 vsl = data->vsl1;
1225 comparison = flip_comparison(comparison);
1226 }
1227 add_comparison_var_sym(left_var, left_vsl, comparison, var, vsl);
1228 } END_FOR_EACH_PTR(tmp);
1229
1230 done:
1231 free_string(right_var);
1232 }
1233
1234 static void match_assign(struct expression *expr)
1235 {
1236 struct expression *right;
1237
1238 if (expr->op != '=')
1239 return;
1240 if (__in_fake_assign || outside_of_function())
1241 return;
1242
1243 if (is_struct(expr->left))
1244 return;
1245
1246 copy_comparisons(expr->left, expr->right);
1247 add_comparison(expr->left, SPECIAL_EQUAL, expr->right);
1248
1249 right = strip_expr(expr->right);
1250 if (right->type == EXPR_BINOP)
1251 match_binop_assign(expr);
1252 }
1253
1254 int get_comparison_strings(const char *one, const char *two)
1255 {
1256 char buf[256];
1257 struct smatch_state *state;
1258 int invert = 0;
1259 int ret = 0;
1260
1261 if (strcmp(one, two) == 0)
1262 return SPECIAL_EQUAL;
1263
1264 if (strcmp(one, two) > 0) {
1265 const char *tmp = one;
1266
1267 one = two;
1268 two = tmp;
1269 invert = 1;
1270 }
1271
1272 snprintf(buf, sizeof(buf), "%s vs %s", one, two);
1273 state = get_state(compare_id, buf, NULL);
1274 if (state)
1275 ret = state_to_comparison(state);
1276
1277 if (invert)
1278 ret = flip_comparison(ret);
1279
1280 return ret;
1281 }
1282
1283 int get_comparison(struct expression *a, struct expression *b)
1284 {
1285 char *one = NULL;
1286 char *two = NULL;
1287 int ret = 0;
1288
1289 one = chunk_to_var(a);
1290 if (!one)
1291 goto free;
1292 two = chunk_to_var(b);
1293 if (!two)
1294 goto free;
1295
1296 ret = get_comparison_strings(one, two);
1297 free:
1298 free_string(one);
1299 free_string(two);
1300 return ret;
1301 }
1302
1303 int possible_comparison(struct expression *a, int comparison, struct expression *b)
1304 {
1305 char *one = NULL;
1306 char *two = NULL;
1307 int ret = 0;
1308 char buf[256];
1309 struct sm_state *sm;
1310 int saved;
1311
1312 one = chunk_to_var(a);
1313 if (!one)
1314 goto free;
1315 two = chunk_to_var(b);
1316 if (!two)
1317 goto free;
1318
1319
1320 if (strcmp(one, two) == 0 && comparison == SPECIAL_EQUAL) {
1321 ret = 1;
1322 goto free;
1323 }
1324
1325 if (strcmp(one, two) > 0) {
1326 char *tmp = one;
1327
1328 one = two;
1329 two = tmp;
1330 comparison = flip_comparison(comparison);
1331 }
1332
1333 snprintf(buf, sizeof(buf), "%s vs %s", one, two);
1334 sm = get_sm_state(compare_id, buf, NULL);
1335 if (!sm)
1336 goto free;
1337
1338 FOR_EACH_PTR(sm->possible, sm) {
1339 if (!sm->state->data)
1340 continue;
1341 saved = ((struct compare_data *)sm->state->data)->comparison;
1342 if (saved == comparison)
1343 ret = 1;
1344 if (comparison == SPECIAL_EQUAL &&
1345 (saved == SPECIAL_LTE ||
1346 saved == SPECIAL_GTE ||
1347 saved == SPECIAL_UNSIGNED_LTE ||
1348 saved == SPECIAL_UNSIGNED_GTE))
1349 ret = 1;
1350 if (ret == 1)
1351 goto free;
1352 } END_FOR_EACH_PTR(sm);
1353
1354 return ret;
1355 free:
1356 free_string(one);
1357 free_string(two);
1358 return ret;
1359 }
1360
1361 struct state_list *get_all_comparisons(struct expression *expr)
1362 {
1363 struct smatch_state *state;
1364 struct string_list *links;
1365 struct state_list *ret = NULL;
1366 struct sm_state *sm;
1367 char *tmp;
1368
1369 state = get_state_expr(link_id, expr);
1370 if (!state)
1371 return NULL;
1372 links = state->data;
1373
1374 FOR_EACH_PTR(links, tmp) {
1375 sm = get_sm_state(compare_id, tmp, NULL);
1376 if (!sm)
1377 continue;
1378 // FIXME have to compare name with vsl
1379 add_ptr_list(&ret, sm);
1380 } END_FOR_EACH_PTR(tmp);
1381
1382 return ret;
1383 }
1384
1385 struct state_list *get_all_possible_equal_comparisons(struct expression *expr)
1386 {
1387 struct smatch_state *state;
1388 struct string_list *links;
1389 struct state_list *ret = NULL;
1390 struct sm_state *sm;
1391 char *tmp;
1392
1393 state = get_state_expr(link_id, expr);
1394 if (!state)
1395 return NULL;
1396 links = state->data;
1397
1398 FOR_EACH_PTR(links, tmp) {
1399 sm = get_sm_state(compare_id, tmp, NULL);
1400 if (!sm)
1401 continue;
1402 if (!strchr(sm->state->name, '='))
1403 continue;
1404 if (strcmp(sm->state->name, "!=") == 0)
1405 continue;
1406 add_ptr_list(&ret, sm);
1407 } END_FOR_EACH_PTR(tmp);
1408
1409 return ret;
1410 }
1411
1412 static void update_links_from_call(struct expression *left,
1413 int left_compare,
1414 struct expression *right)
1415 {
1416 struct string_list *links;
1417 struct smatch_state *state;
1418 struct compare_data *data;
1419 struct symbol *left_sym, *right_sym;
1420 char *left_var = NULL;
1421 char *right_var = NULL;
1422 struct var_sym_list *left_vsl;
1423 const char *var;
1424 struct var_sym_list *vsl;
1425 int comparison;
1426 char *tmp;
1427
1428 left_var = chunk_to_var_sym(left, &left_sym);
1429 if (!left_var)
1430 goto done;
1431 left_vsl = expr_to_vsl(left);
1432 right_var = chunk_to_var_sym(right, &right_sym);
1433 if (!right_var)
1434 goto done;
1435
1436 state = get_state(link_id, right_var, right_sym);
1437 if (!state)
1438 return;
1439 links = state->data;
1440
1441 FOR_EACH_PTR(links, tmp) {
1442 state = get_state(compare_id, tmp, NULL);
1443 if (!state || !state->data)
1444 continue;
1445 data = state->data;
1446 comparison = data->comparison;
1447 var = data->var2;
1448 vsl = data->vsl2;
1449 if (strcmp(var, right_var) == 0) {
1450 var = data->var1;
1451 vsl = data->vsl1;
1452 comparison = flip_comparison(comparison);
1453 }
1454 comparison = combine_comparisons(left_compare, comparison);
1455 if (!comparison)
1456 continue;
1457 add_comparison_var_sym(left_var, left_vsl, comparison, var, vsl);
1458 } END_FOR_EACH_PTR(tmp);
1459
1460 done:
1461 free_string(right_var);
1462 }
1463
1464 void __add_comparison_info(struct expression *expr, struct expression *call, const char *range)
1465 {
1466 struct expression *arg;
1467 int comparison;
1468 const char *c = range;
1469
1470 if (!str_to_comparison_arg(c, call, &comparison, &arg))
1471 return;
1472 update_links_from_call(expr, comparison, arg);
1473 add_comparison(expr, comparison, arg);
1474 }
1475
1476 static char *range_comparison_to_param_helper(struct expression *expr, char starts_with, int ignore)
1477 {
1478 struct symbol *param;
1479 char *var = NULL;
1480 char buf[256];
1481 char *ret_str = NULL;
1482 int compare;
1483 int i;
1484
1485 var = chunk_to_var(expr);
1486 if (!var)
1487 goto free;
1488
1489 i = -1;
1490 FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, param) {
1491 i++;
1492 if (i == ignore)
1493 continue;
1494 if (!param->ident)
1495 continue;
1496 snprintf(buf, sizeof(buf), "%s orig", param->ident->name);
1497 compare = get_comparison_strings(var, buf);
1498 if (!compare)
1499 continue;
1500 if (show_special(compare)[0] != starts_with)
1501 continue;
1502 snprintf(buf, sizeof(buf), "[%s$%d]", show_special(compare), i);
1503 ret_str = alloc_sname(buf);
1504 break;
1505 } END_FOR_EACH_PTR(param);
1506
1507 free:
1508 free_string(var);
1509 return ret_str;
1510 }
1511
1512 char *expr_equal_to_param(struct expression *expr, int ignore)
1513 {
1514 return range_comparison_to_param_helper(expr, '=', ignore);
1515 }
1516
1517 char *expr_lte_to_param(struct expression *expr, int ignore)
1518 {
1519 return range_comparison_to_param_helper(expr, '<', ignore);
1520 }
1521
1522 char *expr_param_comparison(struct expression *expr, int ignore)
1523 {
1524 struct symbol *param;
1525 char *var = NULL;
1526 char buf[256];
1527 char *ret_str = NULL;
1528 int compare;
1529 int i;
1530
1531 var = chunk_to_var(expr);
1532 if (!var)
1533 goto free;
1534
1535 i = -1;
1536 FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, param) {
1537 i++;
1538 if (i == ignore)
1539 continue;
1540 if (!param->ident)
1541 continue;
1542 snprintf(buf, sizeof(buf), "%s orig", param->ident->name);
1543 compare = get_comparison_strings(var, buf);
1544 if (!compare)
1545 continue;
1546 snprintf(buf, sizeof(buf), "[%s$%d]", show_special(compare), i);
1547 ret_str = alloc_sname(buf);
1548 break;
1549 } END_FOR_EACH_PTR(param);
1550
1551 free:
1552 free_string(var);
1553 return ret_str;
1554 }
1555
1556 static void free_data(struct symbol *sym)
1557 {
1558 if (__inline_fn)
1559 return;
1560 clear_compare_data_alloc();
1561 }
1562
1563 void register_comparison(int id)
1564 {
1565 compare_id = id;
1566 add_hook(&match_compare, CONDITION_HOOK);
1567 add_hook(&match_assign, ASSIGNMENT_HOOK);
1568 add_hook(&save_start_states, AFTER_DEF_HOOK);
1569 add_unmatched_state_hook(compare_id, unmatched_comparison);
1570 add_merge_hook(compare_id, &merge_compare_states);
1571 add_hook(&free_data, AFTER_FUNC_HOOK);
1572 }
1573
1574 void register_comparison_links(int id)
1575 {
1576 link_id = id;
1577 add_merge_hook(link_id, &merge_links);
1578 add_modification_hook(link_id, &match_modify);
1579 }
1580
1581 void register_comparison_inc_dec(int id)
1582 {
1583 inc_dec_id = id;
1584 add_modification_hook(inc_dec_id, &iter_modify);
1585 }
1586
1587 void register_comparison_inc_dec_links(int id)
1588 {
1589 inc_dec_link_id = id;
1590 set_up_link_functions(inc_dec_id, inc_dec_link_id);
1591 }
Static analysis for C