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user_data: short circuit a bunch of code
[smatch.git] / smatch_extra.c
blob51d21406d44c7792fa80e801638a44bd2fd7d3a7
1 /*
2 * Copyright (C) 2008 Dan Carpenter.
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 * smatch_extra.c is supposed to track the value of every variable.
20 *
21 */
22
23 #define _GNU_SOURCE
24 #include <string.h>
25
26 #include <stdlib.h>
27 #include <errno.h>
28 #ifndef __USE_ISOC99
29 #define __USE_ISOC99
30 #endif
31 #include <limits.h>
32 #include "parse.h"
33 #include "smatch.h"
34 #include "smatch_slist.h"
35 #include "smatch_extra.h"
36
37 static int my_id;
38 static int link_id;
39
40 static void match_link_modify(struct sm_state *sm, struct expression *mod_expr);
41
42 struct string_list *__ignored_macros = NULL;
43 static int in_warn_on_macro(void)
44 {
45 struct statement *stmt;
46 char *tmp;
47 char *macro;
48
49 stmt = get_current_statement();
50 if (!stmt)
51 return 0;
52 macro = get_macro_name(stmt->pos);
53 if (!macro)
54 return 0;
55
56 FOR_EACH_PTR(__ignored_macros, tmp) {
57 if (!strcmp(tmp, macro))
58 return 1;
59 } END_FOR_EACH_PTR(tmp);
60 return 0;
61 }
62
63 typedef void (mod_hook)(const char *name, struct symbol *sym, struct smatch_state *state);
64 DECLARE_PTR_LIST(void_fn_list, mod_hook *);
65 static struct void_fn_list *extra_mod_hooks;
66 void add_extra_mod_hook(mod_hook *fn)
67 {
68 mod_hook **p = malloc(sizeof(mod_hook *));
69 *p = fn;
70 add_ptr_list(&extra_mod_hooks, p);
71 }
72
73 void call_extra_mod_hooks(const char *name, struct symbol *sym, struct smatch_state *state)
74 {
75 mod_hook **fn;
76
77 FOR_EACH_PTR(extra_mod_hooks, fn) {
78 (*fn)(name, sym, state);
79 } END_FOR_EACH_PTR(fn);
80 }
81
82 struct sm_state *set_extra_mod_helper(const char *name, struct symbol *sym, struct smatch_state *state)
83 {
84 remove_from_equiv(name, sym);
85 call_extra_mod_hooks(name, sym, state);
86 if (__in_fake_assign && estate_is_unknown(state) && !get_state(SMATCH_EXTRA, name, sym))
87 return NULL;
88 return set_state(SMATCH_EXTRA, name, sym, state);
89 }
90
91 char *get_other_name_sym(const char *name, struct symbol *sym, struct symbol **new_sym)
92 {
93 struct expression *assigned;
94 char *orig_name = NULL;
95 char buf[256];
96 char *ret = NULL;
97 int skip;
98
99 *new_sym = NULL;
100
101 if (!sym || !sym->ident)
102 return NULL;
103
104 skip = strlen(sym->ident->name);
105 if (name[skip] != '-' || name[skip + 1] != '>')
106 return NULL;
107 skip += 2;
108
109 assigned = get_assigned_expr_name_sym(sym->ident->name, sym);
110 if (!assigned)
111 return NULL;
112 if (assigned->type == EXPR_PREOP || assigned->op == '&') {
113
114 orig_name = expr_to_var_sym(assigned, new_sym);
115 if (!orig_name || !*new_sym)
116 goto free;
117
118 snprintf(buf, sizeof(buf), "%s.%s", orig_name + 1, name + skip);
119 ret = alloc_string(buf);
120 free_string(orig_name);
121 return ret;
122 }
123
124 if (assigned->type != EXPR_DEREF)
125 goto free;
126
127 orig_name = expr_to_var_sym(assigned, new_sym);
128 if (!orig_name || !*new_sym)
129 goto free;
130
131 snprintf(buf, sizeof(buf), "%s->%s", orig_name, name + skip);
132 ret = alloc_string(buf);
133 free_string(orig_name);
134 return ret;
135
136 free:
137 free_string(orig_name);
138 return NULL;
139 }
140
141 struct sm_state *set_extra_mod(const char *name, struct symbol *sym, struct smatch_state *state)
142 {
143 char *new_name;
144 struct symbol *new_sym;
145 struct sm_state *sm;
146
147 sm = set_extra_mod_helper(name, sym, state);
148 new_name = get_other_name_sym(name, sym, &new_sym);
149 if (new_name && new_sym)
150 set_extra_mod_helper(new_name, new_sym, state);
151 free_string(new_name);
152 return sm;
153 }
154
155 static void clear_array_states(struct expression *array)
156 {
157 struct sm_state *sm;
158
159 sm = get_sm_state_expr(link_id, array);
160 if (sm)
161 match_link_modify(sm, NULL);
162 }
163
164 static struct sm_state *set_extra_array_mod(struct expression *expr, struct smatch_state *state)
165 {
166 struct expression *array;
167 struct var_sym_list *vsl;
168 struct var_sym *vs;
169 char *name;
170 struct symbol *sym;
171 struct sm_state *ret = NULL;
172
173 array = get_array_base(expr);
174
175 name = expr_to_chunk_sym_vsl(expr, &sym, &vsl);
176 if (!name || !vsl) {
177 clear_array_states(array);
178 goto free;
179 }
180
181 FOR_EACH_PTR(vsl, vs) {
182 store_link(link_id, vs->var, vs->sym, name, sym);
183 } END_FOR_EACH_PTR(vs);
184
185 call_extra_mod_hooks(name, sym, state);
186 ret = set_state(SMATCH_EXTRA, name, sym, state);
187 free:
188 free_string(name);
189 return ret;
190 }
191
192 struct sm_state *set_extra_expr_mod(struct expression *expr, struct smatch_state *state)
193 {
194 struct symbol *sym;
195 char *name;
196 struct sm_state *ret = NULL;
197
198 if (is_array(expr))
199 return set_extra_array_mod(expr, state);
200
201 expr = strip_expr(expr);
202 name = expr_to_var_sym(expr, &sym);
203 if (!name || !sym)
204 goto free;
205 ret = set_extra_mod(name, sym, state);
206 free:
207 free_string(name);
208 return ret;
209 }
210
211 void set_extra_nomod(const char *name, struct symbol *sym, struct smatch_state *state)
212 {
213 char *new_name;
214 struct symbol *new_sym;
215 struct relation *rel;
216 struct smatch_state *orig_state;
217
218 orig_state = get_state(SMATCH_EXTRA, name, sym);
219
220 new_name = get_other_name_sym(name, sym, &new_sym);
221 if (new_name && new_sym)
222 set_state(SMATCH_EXTRA, new_name, new_sym, state);
223 free_string(new_name);
224
225 if (!estate_related(orig_state)) {
226 set_state(SMATCH_EXTRA, name, sym, state);
227 return;
228 }
229
230 set_related(state, estate_related(orig_state));
231 FOR_EACH_PTR(estate_related(orig_state), rel) {
232 struct smatch_state *estate;
233
234 if (option_debug_related)
235 sm_msg("%s updating related %s to %s", name, rel->name, state->name);
236 estate = get_state(SMATCH_EXTRA, rel->name, rel->sym);
237 if (!estate)
238 continue;
239 set_state(SMATCH_EXTRA, rel->name, rel->sym, clone_estate_cast(estate_type(estate), state));
240 } END_FOR_EACH_PTR(rel);
241 }
242
243 void set_extra_nomod_vsl(const char *name, struct symbol *sym, struct var_sym_list *vsl, struct smatch_state *state)
244 {
245 struct var_sym *vs;
246
247 FOR_EACH_PTR(vsl, vs) {
248 store_link(link_id, vs->var, vs->sym, name, sym);
249 } END_FOR_EACH_PTR(vs);
250
251 set_extra_nomod(name, sym, state);
252 }
253
254 /*
255 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
256 */
257 void set_extra_expr_nomod(struct expression *expr, struct smatch_state *state)
258 {
259 struct var_sym_list *vsl;
260 struct var_sym *vs;
261 char *name;
262 struct symbol *sym;
263
264 name = expr_to_chunk_sym_vsl(expr, &sym, &vsl);
265 if (!name || !vsl)
266 goto free;
267 FOR_EACH_PTR(vsl, vs) {
268 store_link(link_id, vs->var, vs->sym, name, sym);
269 } END_FOR_EACH_PTR(vs);
270
271 set_extra_nomod(name, sym, state);
272 free:
273 free_string(name);
274 }
275
276 static void set_extra_true_false(const char *name, struct symbol *sym,
277 struct smatch_state *true_state,
278 struct smatch_state *false_state)
279 {
280 char *new_name;
281 struct symbol *new_sym;
282 struct relation *rel;
283 struct smatch_state *orig_state;
284
285 if (!true_state && !false_state)
286 return;
287
288 if (in_warn_on_macro())
289 return;
290
291 new_name = get_other_name_sym(name, sym, &new_sym);
292 if (new_name && new_sym)
293 set_true_false_states(SMATCH_EXTRA, new_name, new_sym, true_state, false_state);
294 free_string(new_name);
295
296 orig_state = get_state(SMATCH_EXTRA, name, sym);
297
298 if (!estate_related(orig_state)) {
299 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
300 return;
301 }
302
303 if (true_state)
304 set_related(true_state, estate_related(orig_state));
305 if (false_state)
306 set_related(false_state, estate_related(orig_state));
307
308 FOR_EACH_PTR(estate_related(orig_state), rel) {
309 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
310 true_state, false_state);
311 } END_FOR_EACH_PTR(rel);
312 }
313
314 static void set_extra_chunk_true_false(struct expression *expr,
315 struct smatch_state *true_state,
316 struct smatch_state *false_state)
317 {
318 struct var_sym_list *vsl;
319 struct var_sym *vs;
320 struct symbol *type;
321 char *name;
322 struct symbol *sym;
323
324 if (in_warn_on_macro())
325 return;
326
327 type = get_type(expr);
328 if (!type)
329 return;
330
331 name = expr_to_chunk_sym_vsl(expr, &sym, &vsl);
332 if (!name || !vsl)
333 goto free;
334 FOR_EACH_PTR(vsl, vs) {
335 store_link(link_id, vs->var, vs->sym, name, sym);
336 } END_FOR_EACH_PTR(vs);
337
338 set_true_false_states(SMATCH_EXTRA, name, sym,
339 clone_estate(true_state),
340 clone_estate(false_state));
341 free:
342 free_string(name);
343 }
344
345 static void set_extra_expr_true_false(struct expression *expr,
346 struct smatch_state *true_state,
347 struct smatch_state *false_state)
348 {
349 char *name;
350 struct symbol *sym;
351 sval_t sval;
352
353 if (!true_state && !false_state)
354 return;
355
356 if (get_value(expr, &sval))
357 return;
358
359 expr = strip_expr(expr);
360 name = expr_to_var_sym(expr, &sym);
361 if (!name || !sym) {
362 free_string(name);
363 set_extra_chunk_true_false(expr, true_state, false_state);
364 return;
365 }
366 set_extra_true_false(name, sym, true_state, false_state);
367 free_string(name);
368 }
369
370 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
371 {
372 struct expression *iter_var;
373 struct expression *condition;
374 struct sm_state *sm;
375 struct smatch_state *estate;
376 sval_t start;
377
378 condition = strip_expr(loop->iterator_pre_condition);
379 if (!condition)
380 return NULL;
381 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
382 return NULL;
383 if (condition->op != SPECIAL_DECREMENT)
384 return NULL;
385
386 iter_var = condition->unop;
387 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
388 if (!sm)
389 return NULL;
390 if (sval_cmp_val(estate_min(sm->state), 0) < 0)
391 return NULL;
392 start = estate_max(sm->state);
393 if (sval_cmp_val(start, 0) <= 0)
394 return NULL;
395 if (!sval_is_max(start))
396 start.value--;
397
398 if (condition->type == EXPR_PREOP) {
399 estate = alloc_estate_range(sval_type_val(start.type, 1), start);
400 if (estate_has_hard_max(sm->state))
401 estate_set_hard_max(estate);
402 estate_copy_fuzzy_max(estate, sm->state);
403 set_extra_expr_mod(iter_var, estate);
404 }
405 if (condition->type == EXPR_POSTOP) {
406 estate = alloc_estate_range(sval_type_val(start.type, 0), start);
407 if (estate_has_hard_max(sm->state))
408 estate_set_hard_max(estate);
409 estate_copy_fuzzy_max(estate, sm->state);
410 set_extra_expr_mod(iter_var, estate);
411 }
412 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
413 }
414
415 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
416 struct expression *condition)
417 {
418 struct expression *iter_var;
419 struct sm_state *sm;
420 struct smatch_state *estate;
421 sval_t start, end, max;
422
423 iter_var = iter_expr->unop;
424 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
425 if (!sm)
426 return NULL;
427 if (!estate_get_single_value(sm->state, &start))
428 return NULL;
429 if (get_implied_max(condition->right, &end))
430 end = sval_cast(get_type(iter_var), end);
431 else
432 end = sval_type_max(get_type(iter_var));
433
434 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
435 return NULL;
436
437 switch (condition->op) {
438 case SPECIAL_UNSIGNED_LT:
439 case SPECIAL_NOTEQUAL:
440 case '<':
441 if (!sval_is_min(end))
442 end.value--;
443 break;
444 case SPECIAL_UNSIGNED_LTE:
445 case SPECIAL_LTE:
446 break;
447 default:
448 return NULL;
449 }
450 if (sval_cmp(end, start) < 0)
451 return NULL;
452 estate = alloc_estate_range(start, end);
453 if (get_hard_max(condition->right, &max)) {
454 estate_set_hard_max(estate);
455 if (condition->op == '<' ||
456 condition->op == SPECIAL_UNSIGNED_LT ||
457 condition->op == SPECIAL_NOTEQUAL)
458 max.value--;
459 estate_set_fuzzy_max(estate, max);
460 }
461 set_extra_expr_mod(iter_var, estate);
462 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
463 }
464
465 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
466 struct expression *condition)
467 {
468 struct expression *iter_var;
469 struct sm_state *sm;
470 struct smatch_state *estate;
471 sval_t start, end;
472
473 iter_var = iter_expr->unop;
474 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
475 if (!sm)
476 return NULL;
477 if (!estate_get_single_value(sm->state, &start))
478 return NULL;
479 if (!get_implied_min(condition->right, &end))
480 end = sval_type_min(get_type(iter_var));
481 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
482 return NULL;
483
484 switch (condition->op) {
485 case SPECIAL_NOTEQUAL:
486 case '>':
487 if (!sval_is_min(end) && !sval_is_max(end))
488 end.value++;
489 break;
490 case SPECIAL_GTE:
491 break;
492 default:
493 return NULL;
494 }
495 if (sval_cmp(end, start) > 0)
496 return NULL;
497 estate = alloc_estate_range(end, start);
498 estate_set_hard_max(estate);
499 estate_set_fuzzy_max(estate, estate_get_fuzzy_max(estate));
500 set_extra_expr_mod(iter_var, estate);
501 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
502 }
503
504 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
505 {
506 struct expression *iter_expr;
507 struct expression *condition;
508
509 if (!loop->iterator_post_statement)
510 return NULL;
511 if (loop->iterator_post_statement->type != STMT_EXPRESSION)
512 return NULL;
513 iter_expr = loop->iterator_post_statement->expression;
514 if (!loop->iterator_pre_condition)
515 return NULL;
516 if (loop->iterator_pre_condition->type != EXPR_COMPARE)
517 return NULL;
518 condition = loop->iterator_pre_condition;
519
520 if (iter_expr->op == SPECIAL_INCREMENT)
521 return handle_canonical_for_inc(iter_expr, condition);
522 if (iter_expr->op == SPECIAL_DECREMENT)
523 return handle_canonical_for_dec(iter_expr, condition);
524 return NULL;
525 }
526
527 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct stree **stree)
528 {
529 struct sm_state *ret;
530
531 __push_fake_cur_stree();
532 if (!loop->iterator_post_statement)
533 ret = handle_canonical_while_count_down(loop);
534 else
535 ret = handle_canonical_for_loops(loop);
536 *stree = __pop_fake_cur_stree();
537 return ret;
538 }
539
540 int __iterator_unchanged(struct sm_state *sm)
541 {
542 if (!sm)
543 return 0;
544 if (get_sm_state(my_id, sm->name, sm->sym) == sm)
545 return 1;
546 return 0;
547 }
548
549 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
550 {
551 sval_t after_value;
552
553 /* paranoid checking. prolly not needed */
554 condition = strip_expr(condition);
555 if (!condition)
556 return;
557 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
558 return;
559 if (condition->op != SPECIAL_DECREMENT)
560 return;
561 after_value = estate_min(sm->state);
562 after_value.value--;
563 set_extra_mod(sm->name, sm->sym, alloc_estate_sval(after_value));
564 }
565
566 void __extra_pre_loop_hook_after(struct sm_state *sm,
567 struct statement *iterator,
568 struct expression *condition)
569 {
570 struct expression *iter_expr;
571 sval_t limit;
572 struct smatch_state *state;
573
574 if (!iterator) {
575 while_count_down_after(sm, condition);
576 return;
577 }
578
579 iter_expr = iterator->expression;
580
581 if (condition->type != EXPR_COMPARE)
582 return;
583 if (iter_expr->op == SPECIAL_INCREMENT) {
584 limit = sval_binop(estate_max(sm->state), '+',
585 sval_type_val(estate_type(sm->state), 1));
586 } else {
587 limit = sval_binop(estate_min(sm->state), '-',
588 sval_type_val(estate_type(sm->state), 1));
589 }
590 if (!estate_has_hard_max(sm->state) && !__has_breaks()) {
591 if (iter_expr->op == SPECIAL_INCREMENT)
592 state = alloc_estate_range(estate_min(sm->state), limit);
593 else
594 state = alloc_estate_range(limit, estate_max(sm->state));
595 } else {
596 state = alloc_estate_sval(limit);
597 }
598 if (!estate_has_hard_max(sm->state)) {
599 estate_clear_hard_max(state);
600 }
601 if (estate_has_fuzzy_max(sm->state)) {
602 sval_t hmax = estate_get_fuzzy_max(sm->state);
603 sval_t max = estate_max(sm->state);
604
605 if (sval_cmp(hmax, max) != 0)
606 estate_clear_fuzzy_max(state);
607 } else if (!estate_has_fuzzy_max(sm->state)) {
608 estate_clear_fuzzy_max(state);
609 }
610
611 set_extra_mod(sm->name, sm->sym, state);
612 }
613
614 static struct stree *unmatched_stree;
615 static struct smatch_state *unmatched_state(struct sm_state *sm)
616 {
617 struct smatch_state *state;
618
619 if (unmatched_stree) {
620 state = get_state_stree(unmatched_stree, SMATCH_EXTRA, sm->name, sm->sym);
621 if (state)
622 return state;
623 }
624 if (parent_is_gone_var_sym(sm->name, sm->sym))
625 return alloc_estate_empty();
626 return alloc_estate_whole(estate_type(sm->state));
627 }
628
629 static void clear_the_pointed_at(struct expression *expr)
630 {
631 struct stree *stree;
632 char *name;
633 struct symbol *sym;
634 struct sm_state *tmp;
635
636 name = expr_to_var_sym(expr, &sym);
637 if (!name || !sym)
638 goto free;
639
640 stree = __get_cur_stree();
641 FOR_EACH_MY_SM(SMATCH_EXTRA, stree, tmp) {
642 if (tmp->name[0] != '*')
643 continue;
644 if (tmp->sym != sym)
645 continue;
646 if (strcmp(tmp->name + 1, name) != 0)
647 continue;
648 set_extra_mod(tmp->name, tmp->sym, alloc_estate_whole(estate_type(tmp->state)));
649 } END_FOR_EACH_SM(tmp);
650
651 free:
652 free_string(name);
653 }
654
655 static void match_function_call(struct expression *expr)
656 {
657 struct expression *arg;
658 struct expression *tmp;
659
660 /* if we have the db this is handled in smatch_function_hooks.c */
661 if (!option_no_db)
662 return;
663 if (inlinable(expr->fn))
664 return;
665
666 FOR_EACH_PTR(expr->args, arg) {
667 tmp = strip_expr(arg);
668 if (tmp->type == EXPR_PREOP && tmp->op == '&')
669 set_extra_expr_mod(tmp->unop, alloc_estate_whole(get_type(tmp->unop)));
670 else
671 clear_the_pointed_at(tmp);
672 } END_FOR_EACH_PTR(arg);
673 }
674
675 static int values_fit_type(struct expression *left, struct expression *right)
676 {
677 struct range_list *rl;
678 struct symbol *type;
679
680 type = get_type(left);
681 if (!type)
682 return 0;
683 get_absolute_rl(right, &rl);
684 if (type_unsigned(type) && sval_is_negative(rl_min(rl)))
685 return 0;
686 if (sval_cmp(sval_type_min(type), rl_min(rl)) > 0)
687 return 0;
688 if (sval_cmp(sval_type_max(type), rl_max(rl)) < 0)
689 return 0;
690 return 1;
691 }
692
693 static void save_chunk_info(struct expression *left, struct expression *right)
694 {
695 struct var_sym_list *vsl;
696 struct var_sym *vs;
697 struct expression *add_expr;
698 struct symbol *type;
699 sval_t sval;
700 char *name;
701 struct symbol *sym;
702
703 if (right->type != EXPR_BINOP || right->op != '-')
704 return;
705 if (!get_value(right->left, &sval))
706 return;
707 if (!expr_to_sym(right->right))
708 return;
709
710 add_expr = binop_expression(left, '+', right->right);
711 type = get_type(add_expr);
712 if (!type)
713 return;
714 name = expr_to_chunk_sym_vsl(add_expr, &sym, &vsl);
715 if (!name || !vsl)
716 goto free;
717 FOR_EACH_PTR(vsl, vs) {
718 store_link(link_id, vs->var, vs->sym, name, sym);
719 } END_FOR_EACH_PTR(vs);
720
721 set_state(SMATCH_EXTRA, name, sym, alloc_estate_sval(sval_cast(type, sval)));
722 free:
723 free_string(name);
724 }
725
726 static void do_array_assign(struct expression *left, int op, struct expression *right)
727 {
728 struct range_list *rl;
729
730 if (op == '=') {
731 get_absolute_rl(right, &rl);
732 rl = cast_rl(get_type(left), rl);
733 } else {
734 rl = alloc_whole_rl(get_type(left));
735 }
736
737 set_extra_array_mod(left, alloc_estate_rl(rl));
738 }
739
740 static void match_untracked_array(struct expression *call, int param)
741 {
742 struct expression *arg;
743
744 arg = get_argument_from_call_expr(call->args, param);
745 arg = strip_expr(arg);
746
747 clear_array_states(arg);
748 }
749
750 static void match_vanilla_assign(struct expression *left, struct expression *right)
751 {
752 struct range_list *orig_rl = NULL;
753 struct range_list *rl = NULL;
754 struct symbol *right_sym;
755 struct symbol *left_type;
756 struct symbol *right_type;
757 char *right_name = NULL;
758 struct symbol *sym;
759 char *name;
760 sval_t max;
761 struct smatch_state *state;
762 int comparison;
763
764 if (is_struct(left))
765 return;
766
767 save_chunk_info(left, right);
768
769 name = expr_to_var_sym(left, &sym);
770 if (!name) {
771 if (is_array(left))
772 do_array_assign(left, '=', right);
773 return;
774 }
775
776 left_type = get_type(left);
777 right_type = get_type(right);
778
779 right_name = expr_to_var_sym(right, &right_sym);
780
781 if (!__in_fake_assign &&
782 !(right->type == EXPR_PREOP && right->op == '&') &&
783 right_name && right_sym &&
784 values_fit_type(left, right) &&
785 !has_symbol(right, sym)) {
786 set_equiv(left, right);
787 goto free;
788 }
789
790 if (is_pointer(right) && get_address_rl(right, &rl)) {
791 state = alloc_estate_rl(rl);
792 goto done;
793 }
794
795 if (__in_fake_assign) {
796 struct smatch_state *right_state;
797 sval_t sval;
798
799 if (get_value(right, &sval)) {
800 sval = sval_cast(left_type, sval);
801 state = alloc_estate_sval(sval);
802 goto done;
803 }
804
805 right_state = get_state(SMATCH_EXTRA, right_name, right_sym);
806 if (right_state) {
807 /* simple assignment */
808 state = clone_estate(right_state);
809 goto done;
810 }
811
812 state = alloc_estate_rl(alloc_whole_rl(left_type));
813 goto done;
814 }
815
816 comparison = get_comparison(left, right);
817 if (comparison) {
818 comparison = flip_comparison(comparison);
819 get_implied_rl(left, &orig_rl);
820 }
821
822 if (get_implied_rl(right, &rl)) {
823 rl = cast_rl(left_type, rl);
824 if (orig_rl)
825 filter_by_comparison(&rl, comparison, orig_rl);
826 state = alloc_estate_rl(rl);
827 if (get_hard_max(right, &max)) {
828 estate_set_hard_max(state);
829 estate_set_fuzzy_max(state, max);
830 }
831 } else {
832 rl = alloc_whole_rl(right_type);
833 rl = cast_rl(left_type, rl);
834 if (orig_rl)
835 filter_by_comparison(&rl, comparison, orig_rl);
836 state = alloc_estate_rl(rl);
837 }
838
839 done:
840 set_extra_mod(name, sym, state);
841 free:
842 free_string(right_name);
843 }
844
845 static int op_remove_assign(int op)
846 {
847 switch (op) {
848 case SPECIAL_ADD_ASSIGN:
849 return '+';
850 case SPECIAL_SUB_ASSIGN:
851 return '-';
852 case SPECIAL_MUL_ASSIGN:
853 return '*';
854 case SPECIAL_DIV_ASSIGN:
855 return '/';
856 case SPECIAL_MOD_ASSIGN:
857 return '%';
858 case SPECIAL_AND_ASSIGN:
859 return '&';
860 case SPECIAL_OR_ASSIGN:
861 return '|';
862 case SPECIAL_XOR_ASSIGN:
863 return '^';
864 case SPECIAL_SHL_ASSIGN:
865 return SPECIAL_LEFTSHIFT;
866 case SPECIAL_SHR_ASSIGN:
867 return SPECIAL_RIGHTSHIFT;
868 default:
869 return op;
870 }
871 }
872
873 static void match_assign(struct expression *expr)
874 {
875 struct range_list *rl = NULL;
876 struct expression *left;
877 struct expression *right;
878 struct expression *binop_expr;
879 struct symbol *left_type;
880 struct symbol *right_type;
881 struct symbol *sym;
882 char *name;
883 sval_t left_min, left_max;
884 sval_t right_min, right_max;
885 sval_t res_min, res_max;
886
887 left = strip_expr(expr->left);
888
889 right = strip_parens(expr->right);
890 if (right->type == EXPR_CALL && sym_name_is("__builtin_expect", right->fn))
891 right = get_argument_from_call_expr(right->args, 0);
892 while (right->type == EXPR_ASSIGNMENT && right->op == '=')
893 right = strip_parens(right->left);
894
895 if (expr->op == '=' && is_condition(expr->right))
896 return; /* handled in smatch_condition.c */
897 if (expr->op == '=' && right->type == EXPR_CALL)
898 return; /* handled in smatch_function_hooks.c */
899 if (expr->op == '=') {
900 match_vanilla_assign(left, right);
901 return;
902 }
903
904 name = expr_to_var_sym(left, &sym);
905 if (!name)
906 return;
907
908 left_type = get_type(left);
909 right_type = get_type(right);
910
911 res_min = sval_type_min(left_type);
912 res_max = sval_type_max(left_type);
913
914 switch (expr->op) {
915 case SPECIAL_ADD_ASSIGN:
916 get_absolute_max(left, &left_max);
917 get_absolute_max(right, &right_max);
918 if (sval_binop_overflows(left_max, '+', right_max))
919 break;
920 if (get_implied_min(left, &left_min) &&
921 !sval_is_negative_min(left_min) &&
922 get_implied_min(right, &right_min) &&
923 !sval_is_negative_min(right_min)) {
924 res_min = sval_binop(left_min, '+', right_min);
925 res_min = sval_cast(right_type, res_min);
926 }
927 if (inside_loop()) /* we are assuming loops don't lead to wrapping */
928 break;
929 res_max = sval_binop(left_max, '+', right_max);
930 res_max = sval_cast(right_type, res_max);
931 break;
932 case SPECIAL_SUB_ASSIGN:
933 if (get_implied_max(left, &left_max) &&
934 !sval_is_max(left_max) &&
935 get_implied_min(right, &right_min) &&
936 !sval_is_min(right_min)) {
937 res_max = sval_binop(left_max, '-', right_min);
938 res_max = sval_cast(right_type, res_max);
939 }
940 if (inside_loop())
941 break;
942 if (get_implied_min(left, &left_min) &&
943 !sval_is_min(left_min) &&
944 get_implied_max(right, &right_max) &&
945 !sval_is_max(right_max)) {
946 res_min = sval_binop(left_min, '-', right_max);
947 res_min = sval_cast(right_type, res_min);
948 }
949 break;
950 case SPECIAL_AND_ASSIGN:
951 case SPECIAL_MOD_ASSIGN:
952 case SPECIAL_SHL_ASSIGN:
953 case SPECIAL_SHR_ASSIGN:
954 case SPECIAL_OR_ASSIGN:
955 case SPECIAL_XOR_ASSIGN:
956 case SPECIAL_MUL_ASSIGN:
957 case SPECIAL_DIV_ASSIGN:
958 binop_expr = binop_expression(expr->left,
959 op_remove_assign(expr->op),
960 expr->right);
961 if (get_absolute_rl(binop_expr, &rl)) {
962 rl = cast_rl(left_type, rl);
963 set_extra_mod(name, sym, alloc_estate_rl(rl));
964 goto free;
965 }
966 break;
967 }
968 rl = cast_rl(left_type, alloc_rl(res_min, res_max));
969 set_extra_mod(name, sym, alloc_estate_rl(rl));
970 free:
971 free_string(name);
972 }
973
974 static struct smatch_state *increment_state(struct smatch_state *state)
975 {
976 sval_t min = estate_min(state);
977 sval_t max = estate_max(state);
978
979 if (!estate_rl(state))
980 return NULL;
981
982 if (inside_loop())
983 max = sval_type_max(max.type);
984
985 if (!sval_is_min(min) && !sval_is_max(min))
986 min.value++;
987 if (!sval_is_min(max) && !sval_is_max(max))
988 max.value++;
989 return alloc_estate_range(min, max);
990 }
991
992 static struct smatch_state *decrement_state(struct smatch_state *state)
993 {
994 sval_t min = estate_min(state);
995 sval_t max = estate_max(state);
996
997 if (!estate_rl(state))
998 return NULL;
999
1000 if (inside_loop())
1001 min = sval_type_min(min.type);
1002
1003 if (!sval_is_min(min) && !sval_is_max(min))
1004 min.value--;
1005 if (!sval_is_min(max) && !sval_is_max(max))
1006 max.value--;
1007 return alloc_estate_range(min, max);
1008 }
1009
1010 static void clear_pointed_at_state(struct expression *expr)
1011 {
1012 struct symbol *type;
1013
1014 /*
1015 * ALERT: This is sort of a mess. If it's is a struct assigment like
1016 * "foo = bar;", then that's handled by smatch_struct_assignment.c.
1017 * the same thing for p++ where "p" is a struct. Most modifications
1018 * are handled by the assignment hook or the db. Smatch_extra.c doesn't
1019 * use smatch_modification.c because we have to get the ordering right
1020 * or something. So if you have p++ where p is a pointer to a standard
1021 * c type then we handle that here. What a mess.
1022 */
1023
1024 type = get_type(expr);
1025 if (!type || type->type != SYM_PTR)
1026 return;
1027 type = get_real_base_type(type);
1028 if (!type || type->type != SYM_BASETYPE)
1029 return;
1030 set_extra_expr_mod(deref_expression(expr), alloc_estate_whole(type));
1031 }
1032
1033 static void unop_expr(struct expression *expr)
1034 {
1035 struct smatch_state *state;
1036
1037 if (expr->smatch_flags & Handled)
1038 return;
1039
1040 switch (expr->op) {
1041 case SPECIAL_INCREMENT:
1042 state = get_state_expr(SMATCH_EXTRA, expr->unop);
1043 state = increment_state(state);
1044 if (!state)
1045 state = alloc_estate_whole(get_type(expr));
1046 set_extra_expr_mod(expr->unop, state);
1047 clear_pointed_at_state(expr->unop);
1048 break;
1049 case SPECIAL_DECREMENT:
1050 state = get_state_expr(SMATCH_EXTRA, expr->unop);
1051 state = decrement_state(state);
1052 if (!state)
1053 state = alloc_estate_whole(get_type(expr));
1054 set_extra_expr_mod(expr->unop, state);
1055 clear_pointed_at_state(expr->unop);
1056 break;
1057 default:
1058 return;
1059 }
1060 }
1061
1062 static void asm_expr(struct statement *stmt)
1063 {
1064
1065 struct expression *expr;
1066 struct symbol *type;
1067 int state = 0;
1068
1069 FOR_EACH_PTR(stmt->asm_outputs, expr) {
1070 switch (state) {
1071 case 0: /* identifier */
1072 case 1: /* constraint */
1073 state++;
1074 continue;
1075 case 2: /* expression */
1076 state = 0;
1077 type = get_type(strip_expr(expr));
1078 set_extra_expr_mod(expr, alloc_estate_whole(type));
1079 continue;
1080 }
1081 } END_FOR_EACH_PTR(expr);
1082 }
1083
1084 static void check_dereference(struct expression *expr)
1085 {
1086 if (__in_fake_assign)
1087 return;
1088 if (outside_of_function())
1089 return;
1090 if (implied_not_equal(expr, 0))
1091 return;
1092 set_extra_expr_nomod(expr, alloc_estate_range(valid_ptr_min_sval, valid_ptr_max_sval));
1093 }
1094
1095 static void match_dereferences(struct expression *expr)
1096 {
1097 if (expr->type != EXPR_PREOP)
1098 return;
1099 /* it's saying that foo[1] = bar dereferences foo[1] */
1100 if (is_array(expr))
1101 return;
1102 check_dereference(expr->unop);
1103 }
1104
1105 static void match_pointer_as_array(struct expression *expr)
1106 {
1107 if (!is_array(expr))
1108 return;
1109 check_dereference(get_array_base(expr));
1110 }
1111
1112 static void find_dereferences(struct expression *expr)
1113 {
1114 while (expr->type == EXPR_PREOP) {
1115 if (expr->op == '*')
1116 check_dereference(expr->unop);
1117 expr = strip_expr(expr->unop);
1118 }
1119 }
1120
1121 static void set_param_dereferenced(struct expression *arg, char *key, char *unused)
1122 {
1123 struct symbol *sym;
1124 char *name;
1125
1126 name = get_variable_from_key(arg, key, &sym);
1127 if (name && sym)
1128 set_extra_nomod(name, sym, alloc_estate_range(valid_ptr_min_sval, valid_ptr_max_sval));
1129 free_string(name);
1130
1131 find_dereferences(arg);
1132 }
1133
1134 static sval_t add_one(sval_t sval)
1135 {
1136 sval.value++;
1137 return sval;
1138 }
1139
1140 static int handle_postop_inc(struct expression *left, int op, struct expression *right)
1141 {
1142 struct statement *stmt;
1143 struct expression *cond;
1144 struct smatch_state *true_state, *false_state;
1145 sval_t start;
1146 sval_t limit;
1147
1148 /*
1149 * If we're decrementing here then that's a canonical while count down
1150 * so it's handled already. We're only handling loops like:
1151 * i = 0;
1152 * do { ... } while (i++ < 3);
1153 */
1154
1155 if (left->type != EXPR_POSTOP || left->op != SPECIAL_INCREMENT)
1156 return 0;
1157
1158 stmt = __cur_stmt->parent;
1159 if (!stmt)
1160 return 0;
1161 if (stmt->type == STMT_COMPOUND)
1162 stmt = stmt->parent;
1163 if (!stmt || stmt->type != STMT_ITERATOR || !stmt->iterator_post_condition)
1164 return 0;
1165
1166 cond = strip_expr(stmt->iterator_post_condition);
1167 if (cond->type != EXPR_COMPARE || cond->op != op)
1168 return 0;
1169 if (left != strip_expr(cond->left) || right != strip_expr(cond->right))
1170 return 0;
1171
1172 if (!get_implied_value(left->unop, &start))
1173 return 0;
1174 if (!get_implied_value(right, &limit))
1175 return 0;
1176
1177 if (sval_cmp(start, limit) > 0)
1178 return 0;
1179
1180 switch (op) {
1181 case '<':
1182 case SPECIAL_UNSIGNED_LT:
1183 break;
1184 case SPECIAL_LTE:
1185 case SPECIAL_UNSIGNED_LTE:
1186 limit = add_one(limit);
1187 default:
1188 return 0;
1189
1190 }
1191
1192 true_state = alloc_estate_range(add_one(start), limit);
1193 false_state = alloc_estate_range(add_one(limit), add_one(limit));
1194
1195 /* Currently we just discard the false state but when two passes is
1196 * implimented correctly then it will use it.
1197 */
1198
1199 set_extra_expr_true_false(left->unop, true_state, false_state);
1200
1201 return 1;
1202 }
1203
1204 static void handle_comparison(struct symbol *type, struct expression *left, int op, struct expression *right)
1205 {
1206 struct range_list *left_orig;
1207 struct range_list *left_true;
1208 struct range_list *left_false;
1209 struct range_list *right_orig;
1210 struct range_list *right_true;
1211 struct range_list *right_false;
1212 struct smatch_state *left_true_state;
1213 struct smatch_state *left_false_state;
1214 struct smatch_state *right_true_state;
1215 struct smatch_state *right_false_state;
1216 sval_t dummy, hard_max;
1217 int left_postop = 0;
1218 int right_postop = 0;
1219
1220 if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
1221 if (left->type == EXPR_POSTOP) {
1222 left->smatch_flags |= Handled;
1223 left_postop = left->op;
1224 if (handle_postop_inc(left, op, right))
1225 return;
1226 }
1227 left = strip_parens(left->unop);
1228 }
1229 while (left->type == EXPR_ASSIGNMENT)
1230 left = strip_parens(left->left);
1231
1232 if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
1233 if (right->type == EXPR_POSTOP) {
1234 right->smatch_flags |= Handled;
1235 right_postop = right->op;
1236 }
1237 right = strip_parens(right->unop);
1238 }
1239
1240 get_real_absolute_rl(left, &left_orig);
1241 left_orig = cast_rl(type, left_orig);
1242
1243 get_real_absolute_rl(right, &right_orig);
1244 right_orig = cast_rl(type, right_orig);
1245
1246 split_comparison_rl(left_orig, op, right_orig, &left_true, &left_false, &right_true, &right_false);
1247
1248 left_true = rl_truncate_cast(get_type(strip_expr(left)), left_true);
1249 left_false = rl_truncate_cast(get_type(strip_expr(left)), left_false);
1250 right_true = rl_truncate_cast(get_type(strip_expr(right)), right_true);
1251 right_false = rl_truncate_cast(get_type(strip_expr(right)), right_false);
1252
1253 if (!left_true || !left_false) {
1254 struct range_list *tmp_true, *tmp_false;
1255
1256 split_comparison_rl(alloc_whole_rl(type), op, right_orig, &tmp_true, &tmp_false, NULL, NULL);
1257 tmp_true = rl_truncate_cast(get_type(strip_expr(left)), tmp_true);
1258 tmp_false = rl_truncate_cast(get_type(strip_expr(left)), tmp_false);
1259 if (tmp_true && tmp_false)
1260 __save_imaginary_state(left, tmp_true, tmp_false);
1261 }
1262
1263 if (!right_true || !right_false) {
1264 struct range_list *tmp_true, *tmp_false;
1265
1266 split_comparison_rl(alloc_whole_rl(type), op, right_orig, NULL, NULL, &tmp_true, &tmp_false);
1267 tmp_true = rl_truncate_cast(get_type(strip_expr(right)), tmp_true);
1268 tmp_false = rl_truncate_cast(get_type(strip_expr(right)), tmp_false);
1269 if (tmp_true && tmp_false)
1270 __save_imaginary_state(right, tmp_true, tmp_false);
1271 }
1272
1273 left_true_state = alloc_estate_rl(left_true);
1274 left_false_state = alloc_estate_rl(left_false);
1275 right_true_state = alloc_estate_rl(right_true);
1276 right_false_state = alloc_estate_rl(right_false);
1277
1278 switch (op) {
1279 case '<':
1280 case SPECIAL_UNSIGNED_LT:
1281 case SPECIAL_UNSIGNED_LTE:
1282 case SPECIAL_LTE:
1283 if (get_hard_max(right, &dummy))
1284 estate_set_hard_max(left_true_state);
1285 if (get_hard_max(left, &dummy))
1286 estate_set_hard_max(right_false_state);
1287 break;
1288 case '>':
1289 case SPECIAL_UNSIGNED_GT:
1290 case SPECIAL_UNSIGNED_GTE:
1291 case SPECIAL_GTE:
1292 if (get_hard_max(left, &dummy))
1293 estate_set_hard_max(right_true_state);
1294 if (get_hard_max(right, &dummy))
1295 estate_set_hard_max(left_false_state);
1296 break;
1297 }
1298
1299 switch (op) {
1300 case '<':
1301 case SPECIAL_UNSIGNED_LT:
1302 case SPECIAL_UNSIGNED_LTE:
1303 case SPECIAL_LTE:
1304 if (get_hard_max(right, &hard_max)) {
1305 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1306 hard_max.value--;
1307 estate_set_fuzzy_max(left_true_state, hard_max);
1308 }
1309 if (get_implied_value(right, &hard_max)) {
1310 if (op == SPECIAL_UNSIGNED_LTE ||
1311 op == SPECIAL_LTE)
1312 hard_max.value++;
1313 estate_set_fuzzy_max(left_false_state, hard_max);
1314 }
1315 if (get_hard_max(left, &hard_max)) {
1316 if (op == SPECIAL_UNSIGNED_LTE ||
1317 op == SPECIAL_LTE)
1318 hard_max.value--;
1319 estate_set_fuzzy_max(right_false_state, hard_max);
1320 }
1321 if (get_implied_value(left, &hard_max)) {
1322 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1323 hard_max.value++;
1324 estate_set_fuzzy_max(right_true_state, hard_max);
1325 }
1326 break;
1327 case '>':
1328 case SPECIAL_UNSIGNED_GT:
1329 case SPECIAL_UNSIGNED_GTE:
1330 case SPECIAL_GTE:
1331 if (get_hard_max(left, &hard_max)) {
1332 if (op == '>' || op == SPECIAL_UNSIGNED_GT)
1333 hard_max.value--;
1334 estate_set_fuzzy_max(right_true_state, hard_max);
1335 }
1336 if (get_implied_value(left, &hard_max)) {
1337 if (op == SPECIAL_UNSIGNED_GTE ||
1338 op == SPECIAL_GTE)
1339 hard_max.value++;
1340 estate_set_fuzzy_max(right_false_state, hard_max);
1341 }
1342 if (get_hard_max(right, &hard_max)) {
1343 if (op == SPECIAL_UNSIGNED_LTE ||
1344 op == SPECIAL_LTE)
1345 hard_max.value--;
1346 estate_set_fuzzy_max(left_false_state, hard_max);
1347 }
1348 if (get_implied_value(right, &hard_max)) {
1349 if (op == '>' ||
1350 op == SPECIAL_UNSIGNED_GT)
1351 hard_max.value++;
1352 estate_set_fuzzy_max(left_true_state, hard_max);
1353 }
1354 break;
1355 case SPECIAL_EQUAL:
1356 if (get_hard_max(left, &hard_max))
1357 estate_set_fuzzy_max(right_true_state, hard_max);
1358 if (get_hard_max(right, &hard_max))
1359 estate_set_fuzzy_max(left_true_state, hard_max);
1360 break;
1361 }
1362
1363 if (get_hard_max(left, &hard_max)) {
1364 estate_set_hard_max(left_true_state);
1365 estate_set_hard_max(left_false_state);
1366 }
1367 if (get_hard_max(right, &hard_max)) {
1368 estate_set_hard_max(right_true_state);
1369 estate_set_hard_max(right_false_state);
1370 }
1371
1372 if (left_postop == SPECIAL_INCREMENT) {
1373 left_true_state = increment_state(left_true_state);
1374 left_false_state = increment_state(left_false_state);
1375 }
1376 if (left_postop == SPECIAL_DECREMENT) {
1377 left_true_state = decrement_state(left_true_state);
1378 left_false_state = decrement_state(left_false_state);
1379 }
1380 if (right_postop == SPECIAL_INCREMENT) {
1381 right_true_state = increment_state(right_true_state);
1382 right_false_state = increment_state(right_false_state);
1383 }
1384 if (right_postop == SPECIAL_DECREMENT) {
1385 right_true_state = decrement_state(right_true_state);
1386 right_false_state = decrement_state(right_false_state);
1387 }
1388
1389 if (estate_rl(left_true_state) && estates_equiv(left_true_state, left_false_state)) {
1390 left_true_state = NULL;
1391 left_false_state = NULL;
1392 }
1393
1394 if (estate_rl(right_true_state) && estates_equiv(right_true_state, right_false_state)) {
1395 right_true_state = NULL;
1396 right_false_state = NULL;
1397 }
1398
1399 set_extra_expr_true_false(left, left_true_state, left_false_state);
1400 set_extra_expr_true_false(right, right_true_state, right_false_state);
1401 }
1402
1403 static int is_simple_math(struct expression *expr)
1404 {
1405 if (!expr)
1406 return 0;
1407 if (expr->type != EXPR_BINOP)
1408 return 0;
1409 switch (expr->op) {
1410 case '+':
1411 case '-':
1412 case '*':
1413 return 1;
1414 }
1415 return 0;
1416 }
1417
1418 static void move_known_values(struct expression **left_p, struct expression **right_p)
1419 {
1420 struct expression *left = *left_p;
1421 struct expression *right = *right_p;
1422 sval_t sval;
1423
1424 if (get_implied_value(left, &sval)) {
1425 if (!is_simple_math(right))
1426 return;
1427 if (right->op == '*') {
1428 sval_t divisor;
1429
1430 if (!get_value(right->right, &divisor))
1431 return;
1432 if (divisor.value == 0 && sval.value % divisor.value)
1433 return;
1434 *left_p = binop_expression(left, invert_op(right->op), right->right);
1435 *right_p = right->left;
1436 return;
1437 }
1438 if (right->op == '+' && get_value(right->left, &sval)) {
1439 *left_p = binop_expression(left, invert_op(right->op), right->left);
1440 *right_p = right->right;
1441 return;
1442 }
1443 if (get_value(right->right, &sval)) {
1444 *left_p = binop_expression(left, invert_op(right->op), right->right);
1445 *right_p = right->left;
1446 return;
1447 }
1448 return;
1449 }
1450 if (get_implied_value(right, &sval)) {
1451 if (!is_simple_math(left))
1452 return;
1453 if (left->op == '*') {
1454 sval_t divisor;
1455
1456 if (!get_value(left->right, &divisor))
1457 return;
1458 if (divisor.value == 0 && sval.value % divisor.value)
1459 return;
1460 *right_p = binop_expression(right, invert_op(left->op), left->right);
1461 *left_p = left->left;
1462 return;
1463 }
1464 if (left->op == '+' && get_value(left->left, &sval)) {
1465 *right_p = binop_expression(right, invert_op(left->op), left->left);
1466 *left_p = left->right;
1467 return;
1468 }
1469
1470 if (get_value(left->right, &sval)) {
1471 *right_p = binop_expression(right, invert_op(left->op), left->right);
1472 *left_p = left->left;
1473 return;
1474 }
1475 return;
1476 }
1477 }
1478
1479 static int match_func_comparison(struct expression *expr)
1480 {
1481 struct expression *left = strip_expr(expr->left);
1482 struct expression *right = strip_expr(expr->right);
1483 sval_t sval;
1484
1485 /*
1486 * fixme: think about this harder. We should always be trying to limit
1487 * the non-call side as well. If we can't determine the limitter does
1488 * that mean we aren't querying the database and are missing important
1489 * information?
1490 */
1491
1492 if (left->type == EXPR_CALL) {
1493 if (get_implied_value(left, &sval)) {
1494 handle_comparison(get_type(expr), left, expr->op, right);
1495 return 1;
1496 }
1497 function_comparison(left, expr->op, right);
1498 return 1;
1499 }
1500
1501 if (right->type == EXPR_CALL) {
1502 if (get_implied_value(right, &sval)) {
1503 handle_comparison(get_type(expr), left, expr->op, right);
1504 return 1;
1505 }
1506 function_comparison(left, expr->op, right);
1507 return 1;
1508 }
1509
1510 return 0;
1511 }
1512
1513 static void match_comparison(struct expression *expr)
1514 {
1515 struct expression *left_orig = strip_parens(expr->left);
1516 struct expression *right_orig = strip_parens(expr->right);
1517 struct expression *left, *right;
1518 struct expression *prev;
1519 struct symbol *type;
1520
1521 if (match_func_comparison(expr))
1522 return;
1523
1524 type = get_type(expr);
1525 if (!type)
1526 type = &llong_ctype;
1527
1528 left = left_orig;
1529 right = right_orig;
1530 move_known_values(&left, &right);
1531 handle_comparison(type, left, expr->op, right);
1532
1533 prev = get_assigned_expr(left_orig);
1534 if (is_simple_math(prev) && has_variable(prev, left_orig) == 0) {
1535 left = prev;
1536 right = right_orig;
1537 move_known_values(&left, &right);
1538 handle_comparison(type, left, expr->op, right);
1539 }
1540
1541 prev = get_assigned_expr(right_orig);
1542 if (is_simple_math(prev) && has_variable(prev, right_orig) == 0) {
1543 left = left_orig;
1544 right = prev;
1545 move_known_values(&left, &right);
1546 handle_comparison(type, left, expr->op, right);
1547 }
1548 }
1549
1550 static sval_t get_high_mask(sval_t known)
1551 {
1552 sval_t ret;
1553 int i;
1554
1555 ret = known;
1556 ret.value = 0;
1557
1558 for (i = type_bits(known.type) - 1; i >= 0; i--) {
1559 if (known.uvalue & (1ULL << i))
1560 ret.uvalue |= (1ULL << i);
1561 else
1562 return ret;
1563
1564 }
1565 return ret;
1566 }
1567
1568 static void handle_AND_condition(struct expression *expr)
1569 {
1570 struct range_list *orig_rl;
1571 struct range_list *true_rl = NULL;
1572 struct range_list *false_rl = NULL;
1573 sval_t known;
1574 int bit;
1575
1576 if (get_implied_value(expr->left, &known)) {
1577 sval_t low_mask = known;
1578 sval_t high_mask;
1579
1580 if (known.value > 0) {
1581 bit = ffsll(known.value) - 1;
1582 low_mask.uvalue = (1ULL << bit) - 1;
1583 get_absolute_rl(expr->right, &orig_rl);
1584 true_rl = remove_range(orig_rl, sval_type_val(known.type, 0), low_mask);
1585 }
1586 high_mask = get_high_mask(known);
1587 if (high_mask.value) {
1588 bit = ffsll(high_mask.value) - 1;
1589 low_mask.uvalue = (1ULL << bit) - 1;
1590
1591 get_absolute_rl(expr->left, &orig_rl);
1592 if (sval_is_negative(rl_min(orig_rl)))
1593 orig_rl = remove_range(orig_rl, sval_type_min(known.type), sval_type_val(known.type, -1));
1594 false_rl = remove_range(orig_rl, low_mask, sval_type_max(known.type));
1595 if (type_signed(high_mask.type) && type_unsigned(rl_type(false_rl))) {
1596 false_rl = remove_range(false_rl,
1597 sval_type_val(rl_type(false_rl), sval_type_max(known.type).uvalue),
1598 sval_type_val(rl_type(false_rl), -1));
1599 }
1600 }
1601 set_extra_expr_true_false(expr->right,
1602 true_rl ? alloc_estate_rl(true_rl) : NULL,
1603 false_rl ? alloc_estate_rl(false_rl) : NULL);
1604
1605 return;
1606 }
1607
1608 if (get_implied_value(expr->right, &known)) {
1609 sval_t low_mask = known;
1610 sval_t high_mask;
1611
1612 if (known.value > 0) {
1613 bit = ffsll(known.value) - 1;
1614 low_mask.uvalue = (1ULL << bit) - 1;
1615 get_absolute_rl(expr->left, &orig_rl);
1616 true_rl = remove_range(orig_rl, sval_type_val(known.type, 0), low_mask);
1617 }
1618 high_mask = get_high_mask(known);
1619 if (high_mask.value) {
1620 bit = ffsll(high_mask.value) - 1;
1621 low_mask.uvalue = (1ULL << bit) - 1;
1622
1623 get_absolute_rl(expr->left, &orig_rl);
1624 if (sval_is_negative(rl_min(orig_rl)))
1625 orig_rl = remove_range(orig_rl, sval_type_min(known.type), sval_type_val(known.type, -1));
1626 false_rl = remove_range(orig_rl, low_mask, sval_type_max(known.type));
1627 if (type_signed(high_mask.type) && type_unsigned(rl_type(false_rl))) {
1628 false_rl = remove_range(false_rl,
1629 sval_type_val(rl_type(false_rl), sval_type_max(known.type).uvalue),
1630 sval_type_val(rl_type(false_rl), -1));
1631 }
1632 }
1633 set_extra_expr_true_false(expr->left,
1634 true_rl ? alloc_estate_rl(true_rl) : NULL,
1635 false_rl ? alloc_estate_rl(false_rl) : NULL);
1636 return;
1637 }
1638 }
1639
1640 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
1641 void __extra_match_condition(struct expression *expr)
1642 {
1643 struct smatch_state *pre_state;
1644 struct smatch_state *true_state;
1645 struct smatch_state *false_state;
1646
1647 expr = strip_expr(expr);
1648 switch (expr->type) {
1649 case EXPR_CALL:
1650 function_comparison(expr, SPECIAL_NOTEQUAL, zero_expr());
1651 return;
1652 case EXPR_PREOP:
1653 case EXPR_SYMBOL:
1654 case EXPR_DEREF: {
1655 sval_t zero;
1656
1657 zero = sval_blank(expr);
1658 zero.value = 0;
1659
1660 pre_state = get_extra_state(expr);
1661 true_state = estate_filter_sval(pre_state, zero);
1662 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
1663 false_state = alloc_estate_sval(zero);
1664 else
1665 false_state = alloc_estate_empty();
1666 set_extra_expr_true_false(expr, true_state, false_state);
1667 return;
1668 }
1669 case EXPR_COMPARE:
1670 match_comparison(expr);
1671 return;
1672 case EXPR_ASSIGNMENT:
1673 __extra_match_condition(expr->left);
1674 return;
1675 case EXPR_BINOP:
1676 if (expr->op == '&')
1677 handle_AND_condition(expr);
1678 return;
1679 }
1680 }
1681
1682 static void assume_indexes_are_valid(struct expression *expr)
1683 {
1684 struct expression *array_expr;
1685 int array_size;
1686 struct expression *offset;
1687 struct symbol *offset_type;
1688 struct range_list *rl_before;
1689 struct range_list *rl_after;
1690 struct range_list *filter = NULL;
1691 sval_t size;
1692
1693 expr = strip_expr(expr);
1694 if (!is_array(expr))
1695 return;
1696
1697 offset = get_array_offset(expr);
1698 offset_type = get_type(offset);
1699 if (offset_type && type_signed(offset_type)) {
1700 filter = alloc_rl(sval_type_min(offset_type),
1701 sval_type_val(offset_type, -1));
1702 }
1703
1704 array_expr = get_array_base(expr);
1705 array_size = get_real_array_size(array_expr);
1706 if (array_size > 1) {
1707 size = sval_type_val(offset_type, array_size);
1708 add_range(&filter, size, sval_type_max(offset_type));
1709 }
1710
1711 if (!filter)
1712 return;
1713 get_absolute_rl(offset, &rl_before);
1714 rl_after = rl_filter(rl_before, filter);
1715 if (rl_equiv(rl_before, rl_after))
1716 return;
1717 set_extra_expr_nomod(offset, alloc_estate_rl(rl_after));
1718 }
1719
1720 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
1721 int implied_not_equal(struct expression *expr, long long val)
1722 {
1723 return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
1724 }
1725
1726 int implied_not_equal_name_sym(char *name, struct symbol *sym, long long val)
1727 {
1728 struct smatch_state *estate;
1729
1730 estate = get_state(SMATCH_EXTRA, name, sym);
1731 if (!estate)
1732 return 0;
1733 if (!rl_has_sval(estate_rl(estate), sval_type_val(estate_type(estate), 0)))
1734 return 1;
1735 return 0;
1736 }
1737
1738 int parent_is_null_var_sym(const char *name, struct symbol *sym)
1739 {
1740 char buf[256];
1741 char *start;
1742 char *end;
1743 struct smatch_state *state;
1744
1745 strncpy(buf, name, sizeof(buf) - 1);
1746 buf[sizeof(buf) - 1] = '\0';
1747
1748 start = &buf[0];
1749 while (*start == '*') {
1750 start++;
1751 state = get_state(SMATCH_EXTRA, start, sym);
1752 if (!state)
1753 continue;
1754 if (!estate_rl(state))
1755 return 1;
1756 if (estate_min(state).value == 0 &&
1757 estate_max(state).value == 0)
1758 return 1;
1759 }
1760
1761 start = &buf[0];
1762 while (*start == '&')
1763 start++;
1764
1765 while ((end = strrchr(start, '-'))) {
1766 *end = '\0';
1767 state = get_state(SMATCH_EXTRA, start, sym);
1768 if (!state)
1769 continue;
1770 if (estate_min(state).value == 0 &&
1771 estate_max(state).value == 0)
1772 return 1;
1773 }
1774 return 0;
1775 }
1776
1777 int parent_is_null(struct expression *expr)
1778 {
1779 struct symbol *sym;
1780 char *var;
1781 int ret = 0;
1782
1783 expr = strip_expr(expr);
1784 var = expr_to_var_sym(expr, &sym);
1785 if (!var || !sym)
1786 goto free;
1787 ret = parent_is_null_var_sym(var, sym);
1788 free:
1789 free_string(var);
1790 return ret;
1791 }
1792
1793 static int param_used_callback(void *found, int argc, char **argv, char **azColName)
1794 {
1795 *(int *)found = 1;
1796 return 0;
1797 }
1798
1799 static int filter_unused_kzalloc_info(struct expression *call, int param, char *printed_name, struct sm_state *sm)
1800 {
1801 sval_t sval;
1802 int found = 0;
1803
1804 /* for function pointers assume everything is used */
1805 if (call->fn->type != EXPR_SYMBOL)
1806 return 0;
1807
1808 /*
1809 * kzalloc() information is treated as special because so there is just
1810 * a lot of stuff initialized to zero and it makes building the database
1811 * take hours and hours.
1812 *
1813 * In theory, we should just remove this line and not pass any unused
1814 * information, but I'm not sure enough that this code works so I want
1815 * to hold off on that for now.
1816 */
1817 if (!estate_get_single_value(sm->state, &sval) || sval.value != 0)
1818 return 0;
1819
1820 run_sql(&param_used_callback, &found,
1821 "select * from call_implies where %s and type = %d and parameter = %d and key = '%s';",
1822 get_static_filter(call->fn->symbol), PARAM_USED, param, printed_name);
1823 if (found)
1824 return 0;
1825
1826 /* If the database is not built yet, then assume everything is used */
1827 run_sql(&param_used_callback, &found,
1828 "select * from call_implies where %s and type = %d;",
1829 get_static_filter(call->fn->symbol), PARAM_USED);
1830 if (!found)
1831 return 0;
1832
1833 return 1;
1834 }
1835
1836 static void struct_member_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm)
1837 {
1838 if (estate_is_whole(sm->state))
1839 return;
1840 if (filter_unused_kzalloc_info(call, param, printed_name, sm))
1841 return;
1842 sql_insert_caller_info(call, PARAM_VALUE, param, printed_name, sm->state->name);
1843 if (estate_has_fuzzy_max(sm->state))
1844 sql_insert_caller_info(call, FUZZY_MAX, param, printed_name,
1845 sval_to_str(estate_get_fuzzy_max(sm->state)));
1846 }
1847
1848 static void returned_struct_members(int return_id, char *return_ranges, struct expression *expr)
1849 {
1850 struct symbol *returned_sym;
1851 struct sm_state *sm;
1852 const char *param_name;
1853 char *compare_str;
1854 char buf[256];
1855
1856 returned_sym = expr_to_sym(expr);
1857 if (!returned_sym)
1858 return;
1859
1860 FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
1861 if (!estate_rl(sm->state))
1862 continue;
1863 if (returned_sym != sm->sym)
1864 continue;
1865
1866 param_name = get_param_name(sm);
1867 if (!param_name)
1868 continue;
1869 if (strcmp(param_name, "$") == 0)
1870 continue;
1871 compare_str = name_sym_to_param_comparison(sm->name, sm->sym);
1872 if (!compare_str && estate_is_whole(sm->state))
1873 continue;
1874 snprintf(buf, sizeof(buf), "%s%s", sm->state->name, compare_str ?: "");
1875
1876 sql_insert_return_states(return_id, return_ranges, PARAM_VALUE,
1877 -1, param_name, buf);
1878 } END_FOR_EACH_SM(sm);
1879 }
1880
1881 static void db_limited_before(void)
1882 {
1883 unmatched_stree = clone_stree(__get_cur_stree());
1884 }
1885
1886 static void db_limited_after(void)
1887 {
1888 free_stree(&unmatched_stree);
1889 }
1890
1891 static int rl_fits_in_type(struct range_list *rl, struct symbol *type)
1892 {
1893 if (type_bits(rl_type(rl)) <= type_bits(type))
1894 return 1;
1895 if (sval_cmp(rl_max(rl), sval_type_max(type)) > 0)
1896 return 0;
1897 if (sval_is_negative(rl_min(rl)) &&
1898 sval_cmp(rl_min(rl), sval_type_min(type)) < 0)
1899 return 0;
1900 return 1;
1901 }
1902
1903 static void db_param_limit_filter(struct expression *expr, int param, char *key, char *value, enum info_type op)
1904 {
1905 struct expression *arg;
1906 char *name;
1907 struct symbol *sym;
1908 struct var_sym_list *vsl = NULL;
1909 struct sm_state *sm;
1910 struct symbol *compare_type, *var_type;
1911 struct range_list *rl;
1912 struct range_list *limit;
1913 struct range_list *new;
1914
1915 while (expr->type == EXPR_ASSIGNMENT)
1916 expr = strip_expr(expr->right);
1917 if (expr->type != EXPR_CALL)
1918 return;
1919
1920 arg = get_argument_from_call_expr(expr->args, param);
1921 if (!arg)
1922 return;
1923
1924 name = get_chunk_from_key(arg, key, &sym, &vsl);
1925 if (!name)
1926 return;
1927 if (op != PARAM_LIMIT && !sym)
1928 goto free;
1929
1930 if (strcmp(key, "$") == 0)
1931 compare_type = get_arg_type(expr->fn, param);
1932 else
1933 compare_type = get_member_type_from_key(arg, key);
1934
1935 sm = get_sm_state(SMATCH_EXTRA, name, sym);
1936 if (sm)
1937 rl = estate_rl(sm->state);
1938 else
1939 rl = alloc_whole_rl(compare_type);
1940
1941 if (op == PARAM_LIMIT && !rl_fits_in_type(rl, compare_type))
1942 goto free;
1943
1944 call_results_to_rl(expr, compare_type, value, &limit);
1945 new = rl_intersection(rl, limit);
1946
1947 var_type = get_member_type_from_key(arg, key);
1948 new = cast_rl(var_type, new);
1949
1950 /* We want to preserve the implications here */
1951 if (sm && rl_equiv(estate_rl(sm->state), new))
1952 __set_sm(sm);
1953 else {
1954 if (op == PARAM_LIMIT)
1955 set_extra_nomod_vsl(name, sym, vsl, alloc_estate_rl(new));
1956 else
1957 set_extra_mod(name, sym, alloc_estate_rl(new));
1958 }
1959
1960 free:
1961 free_string(name);
1962 }
1963
1964 static void db_param_limit(struct expression *expr, int param, char *key, char *value)
1965 {
1966 db_param_limit_filter(expr, param, key, value, PARAM_LIMIT);
1967 }
1968
1969 static void db_param_filter(struct expression *expr, int param, char *key, char *value)
1970 {
1971 db_param_limit_filter(expr, param, key, value, PARAM_FILTER);
1972 }
1973
1974 static void db_param_add_set(struct expression *expr, int param, char *key, char *value, enum info_type op)
1975 {
1976 struct expression *arg;
1977 char *name;
1978 struct symbol *sym;
1979 struct symbol *type;
1980 struct smatch_state *state;
1981 struct range_list *new = NULL;
1982 struct range_list *added = NULL;
1983
1984 while (expr->type == EXPR_ASSIGNMENT)
1985 expr = strip_expr(expr->right);
1986 if (expr->type != EXPR_CALL)
1987 return;
1988
1989 arg = get_argument_from_call_expr(expr->args, param);
1990 if (!arg)
1991 return;
1992 type = get_member_type_from_key(arg, key);
1993 name = get_variable_from_key(arg, key, &sym);
1994 if (!name || !sym)
1995 goto free;
1996
1997 state = get_state(SMATCH_EXTRA, name, sym);
1998 if (state)
1999 new = estate_rl(state);
2000
2001 call_results_to_rl(expr, type, value, &added);
2002
2003 if (op == PARAM_SET)
2004 new = added;
2005 else
2006 new = rl_union(new, added);
2007
2008 set_extra_mod(name, sym, alloc_estate_rl(new));
2009 free:
2010 free_string(name);
2011 }
2012
2013 static void db_param_add(struct expression *expr, int param, char *key, char *value)
2014 {
2015 db_param_add_set(expr, param, key, value, PARAM_ADD);
2016 }
2017
2018 static void db_param_set(struct expression *expr, int param, char *key, char *value)
2019 {
2020 db_param_add_set(expr, param, key, value, PARAM_SET);
2021 }
2022
2023 static void db_param_value(struct expression *expr, int param, char *key, char *value)
2024 {
2025 struct expression *call;
2026 char *name;
2027 struct symbol *sym;
2028 struct symbol *type;
2029 struct range_list *rl = NULL;
2030
2031 if (param != -1)
2032 return;
2033
2034 call = expr;
2035 while (call->type == EXPR_ASSIGNMENT)
2036 call = strip_expr(call->right);
2037 if (call->type != EXPR_CALL)
2038 return;
2039
2040 type = get_member_type_from_key(expr->left, key);
2041 name = get_variable_from_key(expr->left, key, &sym);
2042 if (!name || !sym)
2043 goto free;
2044
2045 call_results_to_rl(call, type, value, &rl);
2046
2047 set_extra_mod(name, sym, alloc_estate_rl(rl));
2048 free:
2049 free_string(name);
2050 }
2051
2052 static void match_call_info(struct expression *expr)
2053 {
2054 struct smatch_state *state;
2055 struct range_list *rl = NULL;
2056 struct expression *arg;
2057 struct symbol *type;
2058 int i = 0;
2059
2060 FOR_EACH_PTR(expr->args, arg) {
2061 type = get_arg_type(expr->fn, i);
2062
2063 if (get_implied_rl(arg, &rl))
2064 rl = cast_rl(type, rl);
2065 else
2066 rl = cast_rl(type, alloc_whole_rl(get_type(arg)));
2067
2068 if (!is_whole_rl(rl))
2069 sql_insert_caller_info(expr, PARAM_VALUE, i, "$", show_rl(rl));
2070 state = get_state_expr(SMATCH_EXTRA, arg);
2071 if (estate_has_fuzzy_max(state)) {
2072 sql_insert_caller_info(expr, FUZZY_MAX, i, "$",
2073 sval_to_str(estate_get_fuzzy_max(state)));
2074 }
2075 i++;
2076 } END_FOR_EACH_PTR(arg);
2077 }
2078
2079 static void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
2080 {
2081 struct range_list *rl = NULL;
2082 struct smatch_state *state;
2083 struct symbol *type;
2084 char fullname[256];
2085
2086 if (strcmp(key, "*$") == 0)
2087 snprintf(fullname, sizeof(fullname), "*%s", name);
2088 else if (strncmp(key, "$", 1) == 0)
2089 snprintf(fullname, 256, "%s%s", name, key + 1);
2090 else
2091 return;
2092
2093 type = get_member_type_from_key(symbol_expression(sym), key);
2094 str_to_rl(type, value, &rl);
2095 state = alloc_estate_rl(rl);
2096 set_state(SMATCH_EXTRA, fullname, sym, state);
2097 }
2098
2099 static void set_param_hard_max(const char *name, struct symbol *sym, char *key, char *value)
2100 {
2101 struct range_list *rl = NULL;
2102 struct smatch_state *state;
2103 struct symbol *type;
2104 char fullname[256];
2105 sval_t max;
2106
2107 if (strcmp(key, "*$") == 0)
2108 snprintf(fullname, sizeof(fullname), "*%s", name);
2109 else if (strncmp(key, "$", 1) == 0)
2110 snprintf(fullname, 256, "%s%s", name, key + 1);
2111 else
2112 return;
2113
2114 state = get_state(SMATCH_EXTRA, fullname, sym);
2115 if (!state)
2116 return;
2117 type = get_member_type_from_key(symbol_expression(sym), key);
2118 str_to_rl(type, value, &rl);
2119 if (!rl_to_sval(rl, &max))
2120 return;
2121 estate_set_fuzzy_max(state, max);
2122 }
2123
2124 struct smatch_state *get_extra_state(struct expression *expr)
2125 {
2126 char *name;
2127 struct symbol *sym;
2128 struct smatch_state *ret = NULL;
2129 struct range_list *rl;
2130
2131 if (is_pointer(expr) && get_address_rl(expr, &rl))
2132 return alloc_estate_rl(rl);
2133
2134 name = expr_to_known_chunk_sym(expr, &sym);
2135 if (!name)
2136 goto free;
2137
2138 ret = get_state(SMATCH_EXTRA, name, sym);
2139 free:
2140 free_string(name);
2141 return ret;
2142 }
2143
2144 void register_smatch_extra(int id)
2145 {
2146 my_id = id;
2147
2148 add_merge_hook(my_id, &merge_estates);
2149 add_unmatched_state_hook(my_id, &unmatched_state);
2150 select_caller_info_hook(set_param_value, PARAM_VALUE);
2151 select_caller_info_hook(set_param_hard_max, FUZZY_MAX);
2152 select_return_states_before(&db_limited_before);
2153 select_return_states_hook(PARAM_LIMIT, &db_param_limit);
2154 select_return_states_hook(PARAM_FILTER, &db_param_filter);
2155 select_return_states_hook(PARAM_ADD, &db_param_add);
2156 select_return_states_hook(PARAM_SET, &db_param_set);
2157 select_return_states_hook(PARAM_VALUE, &db_param_value);
2158 select_return_states_after(&db_limited_after);
2159 }
2160
2161 static void match_link_modify(struct sm_state *sm, struct expression *mod_expr)
2162 {
2163 struct var_sym_list *links;
2164 struct var_sym *tmp;
2165 struct smatch_state *state;
2166
2167 links = sm->state->data;
2168
2169 FOR_EACH_PTR(links, tmp) {
2170 if (sm->sym == tmp->sym &&
2171 strcmp(sm->name, tmp->var) == 0)
2172 continue;
2173 state = get_state(SMATCH_EXTRA, tmp->var, tmp->sym);
2174 if (!state)
2175 continue;
2176 set_state(SMATCH_EXTRA, tmp->var, tmp->sym, alloc_estate_whole(estate_type(state)));
2177 } END_FOR_EACH_PTR(tmp);
2178 set_state(link_id, sm->name, sm->sym, &undefined);
2179 }
2180
2181 void register_smatch_extra_links(int id)
2182 {
2183 link_id = id;
2184 }
2185
2186 void register_smatch_extra_late(int id)
2187 {
2188 add_merge_hook(link_id, &merge_link_states);
2189 add_modification_hook(link_id, &match_link_modify);
2190 add_hook(&match_dereferences, DEREF_HOOK);
2191 add_hook(&match_pointer_as_array, OP_HOOK);
2192 select_call_implies_hook(DEREFERENCE, &set_param_dereferenced);
2193 add_hook(&match_function_call, FUNCTION_CALL_HOOK);
2194 add_hook(&match_assign, ASSIGNMENT_HOOK);
2195 add_hook(&match_assign, GLOBAL_ASSIGNMENT_HOOK);
2196 add_hook(&unop_expr, OP_HOOK);
2197 add_hook(&asm_expr, ASM_HOOK);
2198 add_untracked_param_hook(&match_untracked_array);
2199
2200 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
2201 add_member_info_callback(my_id, struct_member_callback);
2202 add_split_return_callback(&returned_struct_members);
2203
2204 add_hook(&assume_indexes_are_valid, OP_HOOK);
2205 }
Static analysis for C