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function_hooks: don't mark it as impossible if a function is not in the DB
[smatch.git] / smatch_extra.c
blob2d818b3be70558731623a5e884f94064de2f3474
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 /* Handle conditions like "if (foo + bar < foo) {" */
1514 static int handle_integer_overflow_test(struct expression *expr)
1515 {
1516 struct expression *left, *right;
1517 struct symbol *type;
1518 sval_t left_min, right_min, min, max;
1519
1520 if (expr->op != '<' && expr->op != SPECIAL_UNSIGNED_LT)
1521 return 0;
1522
1523 left = strip_parens(expr->left);
1524 right = strip_parens(expr->right);
1525
1526 if (left->op != '+')
1527 return 0;
1528
1529 type = get_type(expr);
1530 if (!type)
1531 return 0;
1532 if (type_positive_bits(type) == 32) {
1533 max.type = &uint_ctype;
1534 max.uvalue = (unsigned int)-1;
1535 } else if (type_positive_bits(type) == 64) {
1536 max.type = &ulong_ctype;
1537 max.value = (unsigned long long)-1;
1538 } else {
1539 return 0;
1540 }
1541
1542 if (!expr_equiv(left->left, right) && !expr_equiv(left->right, right))
1543 return 0;
1544
1545 get_absolute_min(left->left, &left_min);
1546 get_absolute_min(left->right, &right_min);
1547 min = sval_binop(left_min, '+', right_min);
1548
1549 set_extra_chunk_true_false(left, NULL, alloc_estate_range(min, max));
1550 return 1;
1551 }
1552
1553 static void match_comparison(struct expression *expr)
1554 {
1555 struct expression *left_orig = strip_parens(expr->left);
1556 struct expression *right_orig = strip_parens(expr->right);
1557 struct expression *left, *right;
1558 struct expression *prev;
1559 struct symbol *type;
1560
1561 if (match_func_comparison(expr))
1562 return;
1563
1564 type = get_type(expr);
1565 if (!type)
1566 type = &llong_ctype;
1567
1568 if (handle_integer_overflow_test(expr))
1569 return;
1570
1571 left = left_orig;
1572 right = right_orig;
1573 move_known_values(&left, &right);
1574 handle_comparison(type, left, expr->op, right);
1575
1576 prev = get_assigned_expr(left_orig);
1577 if (is_simple_math(prev) && has_variable(prev, left_orig) == 0) {
1578 left = prev;
1579 right = right_orig;
1580 move_known_values(&left, &right);
1581 handle_comparison(type, left, expr->op, right);
1582 }
1583
1584 prev = get_assigned_expr(right_orig);
1585 if (is_simple_math(prev) && has_variable(prev, right_orig) == 0) {
1586 left = left_orig;
1587 right = prev;
1588 move_known_values(&left, &right);
1589 handle_comparison(type, left, expr->op, right);
1590 }
1591 }
1592
1593 static sval_t get_high_mask(sval_t known)
1594 {
1595 sval_t ret;
1596 int i;
1597
1598 ret = known;
1599 ret.value = 0;
1600
1601 for (i = type_bits(known.type) - 1; i >= 0; i--) {
1602 if (known.uvalue & (1ULL << i))
1603 ret.uvalue |= (1ULL << i);
1604 else
1605 return ret;
1606
1607 }
1608 return ret;
1609 }
1610
1611 static void handle_AND_condition(struct expression *expr)
1612 {
1613 struct range_list *orig_rl;
1614 struct range_list *true_rl = NULL;
1615 struct range_list *false_rl = NULL;
1616 sval_t known;
1617 int bit;
1618
1619 if (get_implied_value(expr->left, &known)) {
1620 sval_t low_mask = known;
1621 sval_t high_mask;
1622
1623 if (known.value > 0) {
1624 bit = ffsll(known.value) - 1;
1625 low_mask.uvalue = (1ULL << bit) - 1;
1626 get_absolute_rl(expr->right, &orig_rl);
1627 true_rl = remove_range(orig_rl, sval_type_val(known.type, 0), low_mask);
1628 }
1629 high_mask = get_high_mask(known);
1630 if (high_mask.value) {
1631 bit = ffsll(high_mask.value) - 1;
1632 low_mask.uvalue = (1ULL << bit) - 1;
1633
1634 get_absolute_rl(expr->left, &orig_rl);
1635 if (sval_is_negative(rl_min(orig_rl)))
1636 orig_rl = remove_range(orig_rl, sval_type_min(known.type), sval_type_val(known.type, -1));
1637 false_rl = remove_range(orig_rl, low_mask, sval_type_max(known.type));
1638 if (type_signed(high_mask.type) && type_unsigned(rl_type(false_rl))) {
1639 false_rl = remove_range(false_rl,
1640 sval_type_val(rl_type(false_rl), sval_type_max(known.type).uvalue),
1641 sval_type_val(rl_type(false_rl), -1));
1642 }
1643 }
1644 set_extra_expr_true_false(expr->right,
1645 true_rl ? alloc_estate_rl(true_rl) : NULL,
1646 false_rl ? alloc_estate_rl(false_rl) : NULL);
1647
1648 return;
1649 }
1650
1651 if (get_implied_value(expr->right, &known)) {
1652 sval_t low_mask = known;
1653 sval_t high_mask;
1654
1655 if (known.value > 0) {
1656 bit = ffsll(known.value) - 1;
1657 low_mask.uvalue = (1ULL << bit) - 1;
1658 get_absolute_rl(expr->left, &orig_rl);
1659 true_rl = remove_range(orig_rl, sval_type_val(known.type, 0), low_mask);
1660 }
1661 high_mask = get_high_mask(known);
1662 if (high_mask.value) {
1663 bit = ffsll(high_mask.value) - 1;
1664 low_mask.uvalue = (1ULL << bit) - 1;
1665
1666 get_absolute_rl(expr->left, &orig_rl);
1667 if (sval_is_negative(rl_min(orig_rl)))
1668 orig_rl = remove_range(orig_rl, sval_type_min(known.type), sval_type_val(known.type, -1));
1669 false_rl = remove_range(orig_rl, low_mask, sval_type_max(known.type));
1670 if (type_signed(high_mask.type) && type_unsigned(rl_type(false_rl))) {
1671 false_rl = remove_range(false_rl,
1672 sval_type_val(rl_type(false_rl), sval_type_max(known.type).uvalue),
1673 sval_type_val(rl_type(false_rl), -1));
1674 }
1675 }
1676 set_extra_expr_true_false(expr->left,
1677 true_rl ? alloc_estate_rl(true_rl) : NULL,
1678 false_rl ? alloc_estate_rl(false_rl) : NULL);
1679 return;
1680 }
1681 }
1682
1683 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
1684 void __extra_match_condition(struct expression *expr)
1685 {
1686 struct smatch_state *pre_state;
1687 struct smatch_state *true_state;
1688 struct smatch_state *false_state;
1689
1690 expr = strip_expr(expr);
1691 switch (expr->type) {
1692 case EXPR_CALL:
1693 function_comparison(expr, SPECIAL_NOTEQUAL, zero_expr());
1694 return;
1695 case EXPR_PREOP:
1696 case EXPR_SYMBOL:
1697 case EXPR_DEREF: {
1698 sval_t zero;
1699
1700 zero = sval_blank(expr);
1701 zero.value = 0;
1702
1703 pre_state = get_extra_state(expr);
1704 true_state = estate_filter_sval(pre_state, zero);
1705 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
1706 false_state = alloc_estate_sval(zero);
1707 else
1708 false_state = alloc_estate_empty();
1709 set_extra_expr_true_false(expr, true_state, false_state);
1710 return;
1711 }
1712 case EXPR_COMPARE:
1713 match_comparison(expr);
1714 return;
1715 case EXPR_ASSIGNMENT:
1716 __extra_match_condition(expr->left);
1717 return;
1718 case EXPR_BINOP:
1719 if (expr->op == '&')
1720 handle_AND_condition(expr);
1721 return;
1722 }
1723 }
1724
1725 static void assume_indexes_are_valid(struct expression *expr)
1726 {
1727 struct expression *array_expr;
1728 int array_size;
1729 struct expression *offset;
1730 struct symbol *offset_type;
1731 struct range_list *rl_before;
1732 struct range_list *rl_after;
1733 struct range_list *filter = NULL;
1734 sval_t size;
1735
1736 expr = strip_expr(expr);
1737 if (!is_array(expr))
1738 return;
1739
1740 offset = get_array_offset(expr);
1741 offset_type = get_type(offset);
1742 if (offset_type && type_signed(offset_type)) {
1743 filter = alloc_rl(sval_type_min(offset_type),
1744 sval_type_val(offset_type, -1));
1745 }
1746
1747 array_expr = get_array_base(expr);
1748 array_size = get_real_array_size(array_expr);
1749 if (array_size > 1) {
1750 size = sval_type_val(offset_type, array_size);
1751 add_range(&filter, size, sval_type_max(offset_type));
1752 }
1753
1754 if (!filter)
1755 return;
1756 get_absolute_rl(offset, &rl_before);
1757 rl_after = rl_filter(rl_before, filter);
1758 if (rl_equiv(rl_before, rl_after))
1759 return;
1760 set_extra_expr_nomod(offset, alloc_estate_rl(rl_after));
1761 }
1762
1763 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
1764 int implied_not_equal(struct expression *expr, long long val)
1765 {
1766 return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
1767 }
1768
1769 int implied_not_equal_name_sym(char *name, struct symbol *sym, long long val)
1770 {
1771 struct smatch_state *estate;
1772
1773 estate = get_state(SMATCH_EXTRA, name, sym);
1774 if (!estate)
1775 return 0;
1776 if (!rl_has_sval(estate_rl(estate), sval_type_val(estate_type(estate), 0)))
1777 return 1;
1778 return 0;
1779 }
1780
1781 int parent_is_null_var_sym(const char *name, struct symbol *sym)
1782 {
1783 char buf[256];
1784 char *start;
1785 char *end;
1786 struct smatch_state *state;
1787
1788 strncpy(buf, name, sizeof(buf) - 1);
1789 buf[sizeof(buf) - 1] = '\0';
1790
1791 start = &buf[0];
1792 while (*start == '*') {
1793 start++;
1794 state = get_state(SMATCH_EXTRA, start, sym);
1795 if (!state)
1796 continue;
1797 if (!estate_rl(state))
1798 return 1;
1799 if (estate_min(state).value == 0 &&
1800 estate_max(state).value == 0)
1801 return 1;
1802 }
1803
1804 start = &buf[0];
1805 while (*start == '&')
1806 start++;
1807
1808 while ((end = strrchr(start, '-'))) {
1809 *end = '\0';
1810 state = get_state(SMATCH_EXTRA, start, sym);
1811 if (!state)
1812 continue;
1813 if (estate_min(state).value == 0 &&
1814 estate_max(state).value == 0)
1815 return 1;
1816 }
1817 return 0;
1818 }
1819
1820 int parent_is_null(struct expression *expr)
1821 {
1822 struct symbol *sym;
1823 char *var;
1824 int ret = 0;
1825
1826 expr = strip_expr(expr);
1827 var = expr_to_var_sym(expr, &sym);
1828 if (!var || !sym)
1829 goto free;
1830 ret = parent_is_null_var_sym(var, sym);
1831 free:
1832 free_string(var);
1833 return ret;
1834 }
1835
1836 static int param_used_callback(void *found, int argc, char **argv, char **azColName)
1837 {
1838 *(int *)found = 1;
1839 return 0;
1840 }
1841
1842 static int filter_unused_kzalloc_info(struct expression *call, int param, char *printed_name, struct sm_state *sm)
1843 {
1844 sval_t sval;
1845 int found = 0;
1846
1847 /* for function pointers assume everything is used */
1848 if (call->fn->type != EXPR_SYMBOL)
1849 return 0;
1850
1851 /*
1852 * kzalloc() information is treated as special because so there is just
1853 * a lot of stuff initialized to zero and it makes building the database
1854 * take hours and hours.
1855 *
1856 * In theory, we should just remove this line and not pass any unused
1857 * information, but I'm not sure enough that this code works so I want
1858 * to hold off on that for now.
1859 */
1860 if (!estate_get_single_value(sm->state, &sval) || sval.value != 0)
1861 return 0;
1862
1863 run_sql(&param_used_callback, &found,
1864 "select * from call_implies where %s and type = %d and parameter = %d and key = '%s';",
1865 get_static_filter(call->fn->symbol), PARAM_USED, param, printed_name);
1866 if (found)
1867 return 0;
1868
1869 /* If the database is not built yet, then assume everything is used */
1870 run_sql(&param_used_callback, &found,
1871 "select * from call_implies where %s and type = %d;",
1872 get_static_filter(call->fn->symbol), PARAM_USED);
1873 if (!found)
1874 return 0;
1875
1876 return 1;
1877 }
1878
1879 static void struct_member_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm)
1880 {
1881 if (estate_is_whole(sm->state))
1882 return;
1883 if (filter_unused_kzalloc_info(call, param, printed_name, sm))
1884 return;
1885 sql_insert_caller_info(call, PARAM_VALUE, param, printed_name, sm->state->name);
1886 if (estate_has_fuzzy_max(sm->state))
1887 sql_insert_caller_info(call, FUZZY_MAX, param, printed_name,
1888 sval_to_str(estate_get_fuzzy_max(sm->state)));
1889 }
1890
1891 static void returned_struct_members(int return_id, char *return_ranges, struct expression *expr)
1892 {
1893 struct symbol *returned_sym;
1894 struct sm_state *sm;
1895 const char *param_name;
1896 char *compare_str;
1897 char buf[256];
1898
1899 returned_sym = expr_to_sym(expr);
1900 if (!returned_sym)
1901 return;
1902
1903 FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
1904 if (!estate_rl(sm->state))
1905 continue;
1906 if (returned_sym != sm->sym)
1907 continue;
1908
1909 param_name = get_param_name(sm);
1910 if (!param_name)
1911 continue;
1912 if (strcmp(param_name, "$") == 0)
1913 continue;
1914 compare_str = name_sym_to_param_comparison(sm->name, sm->sym);
1915 if (!compare_str && estate_is_whole(sm->state))
1916 continue;
1917 snprintf(buf, sizeof(buf), "%s%s", sm->state->name, compare_str ?: "");
1918
1919 sql_insert_return_states(return_id, return_ranges, PARAM_VALUE,
1920 -1, param_name, buf);
1921 } END_FOR_EACH_SM(sm);
1922 }
1923
1924 static void db_limited_before(void)
1925 {
1926 unmatched_stree = clone_stree(__get_cur_stree());
1927 }
1928
1929 static void db_limited_after(void)
1930 {
1931 free_stree(&unmatched_stree);
1932 }
1933
1934 static int rl_fits_in_type(struct range_list *rl, struct symbol *type)
1935 {
1936 if (type_bits(rl_type(rl)) <= type_bits(type))
1937 return 1;
1938 if (sval_cmp(rl_max(rl), sval_type_max(type)) > 0)
1939 return 0;
1940 if (sval_is_negative(rl_min(rl)) &&
1941 sval_cmp(rl_min(rl), sval_type_min(type)) < 0)
1942 return 0;
1943 return 1;
1944 }
1945
1946 static void db_param_limit_filter(struct expression *expr, int param, char *key, char *value, enum info_type op)
1947 {
1948 struct expression *arg;
1949 char *name;
1950 struct symbol *sym;
1951 struct var_sym_list *vsl = NULL;
1952 struct sm_state *sm;
1953 struct symbol *compare_type, *var_type;
1954 struct range_list *rl;
1955 struct range_list *limit;
1956 struct range_list *new;
1957
1958 while (expr->type == EXPR_ASSIGNMENT)
1959 expr = strip_expr(expr->right);
1960 if (expr->type != EXPR_CALL)
1961 return;
1962
1963 arg = get_argument_from_call_expr(expr->args, param);
1964 if (!arg)
1965 return;
1966
1967 name = get_chunk_from_key(arg, key, &sym, &vsl);
1968 if (!name)
1969 return;
1970 if (op != PARAM_LIMIT && !sym)
1971 goto free;
1972
1973 if (strcmp(key, "$") == 0)
1974 compare_type = get_arg_type(expr->fn, param);
1975 else
1976 compare_type = get_member_type_from_key(arg, key);
1977
1978 sm = get_sm_state(SMATCH_EXTRA, name, sym);
1979 if (sm)
1980 rl = estate_rl(sm->state);
1981 else
1982 rl = alloc_whole_rl(compare_type);
1983
1984 if (op == PARAM_LIMIT && !rl_fits_in_type(rl, compare_type))
1985 goto free;
1986
1987 call_results_to_rl(expr, compare_type, value, &limit);
1988 new = rl_intersection(rl, limit);
1989
1990 var_type = get_member_type_from_key(arg, key);
1991 new = cast_rl(var_type, new);
1992
1993 /* We want to preserve the implications here */
1994 if (sm && rl_equiv(estate_rl(sm->state), new))
1995 __set_sm(sm);
1996 else {
1997 if (op == PARAM_LIMIT)
1998 set_extra_nomod_vsl(name, sym, vsl, alloc_estate_rl(new));
1999 else
2000 set_extra_mod(name, sym, alloc_estate_rl(new));
2001 }
2002
2003 free:
2004 free_string(name);
2005 }
2006
2007 static void db_param_limit(struct expression *expr, int param, char *key, char *value)
2008 {
2009 db_param_limit_filter(expr, param, key, value, PARAM_LIMIT);
2010 }
2011
2012 static void db_param_filter(struct expression *expr, int param, char *key, char *value)
2013 {
2014 db_param_limit_filter(expr, param, key, value, PARAM_FILTER);
2015 }
2016
2017 static void db_param_add_set(struct expression *expr, int param, char *key, char *value, enum info_type op)
2018 {
2019 struct expression *arg;
2020 char *name;
2021 struct symbol *sym;
2022 struct symbol *type;
2023 struct smatch_state *state;
2024 struct range_list *new = NULL;
2025 struct range_list *added = NULL;
2026
2027 while (expr->type == EXPR_ASSIGNMENT)
2028 expr = strip_expr(expr->right);
2029 if (expr->type != EXPR_CALL)
2030 return;
2031
2032 arg = get_argument_from_call_expr(expr->args, param);
2033 if (!arg)
2034 return;
2035 type = get_member_type_from_key(arg, key);
2036 name = get_variable_from_key(arg, key, &sym);
2037 if (!name || !sym)
2038 goto free;
2039
2040 state = get_state(SMATCH_EXTRA, name, sym);
2041 if (state)
2042 new = estate_rl(state);
2043
2044 call_results_to_rl(expr, type, value, &added);
2045
2046 if (op == PARAM_SET)
2047 new = added;
2048 else
2049 new = rl_union(new, added);
2050
2051 set_extra_mod(name, sym, alloc_estate_rl(new));
2052 free:
2053 free_string(name);
2054 }
2055
2056 static void db_param_add(struct expression *expr, int param, char *key, char *value)
2057 {
2058 db_param_add_set(expr, param, key, value, PARAM_ADD);
2059 }
2060
2061 static void db_param_set(struct expression *expr, int param, char *key, char *value)
2062 {
2063 db_param_add_set(expr, param, key, value, PARAM_SET);
2064 }
2065
2066 static void db_param_value(struct expression *expr, int param, char *key, char *value)
2067 {
2068 struct expression *call;
2069 char *name;
2070 struct symbol *sym;
2071 struct symbol *type;
2072 struct range_list *rl = NULL;
2073
2074 if (param != -1)
2075 return;
2076
2077 call = expr;
2078 while (call->type == EXPR_ASSIGNMENT)
2079 call = strip_expr(call->right);
2080 if (call->type != EXPR_CALL)
2081 return;
2082
2083 type = get_member_type_from_key(expr->left, key);
2084 name = get_variable_from_key(expr->left, key, &sym);
2085 if (!name || !sym)
2086 goto free;
2087
2088 call_results_to_rl(call, type, value, &rl);
2089
2090 set_extra_mod(name, sym, alloc_estate_rl(rl));
2091 free:
2092 free_string(name);
2093 }
2094
2095 static void match_call_info(struct expression *expr)
2096 {
2097 struct smatch_state *state;
2098 struct range_list *rl = NULL;
2099 struct expression *arg;
2100 struct symbol *type;
2101 int i = 0;
2102
2103 FOR_EACH_PTR(expr->args, arg) {
2104 type = get_arg_type(expr->fn, i);
2105
2106 if (get_implied_rl(arg, &rl))
2107 rl = cast_rl(type, rl);
2108 else
2109 rl = cast_rl(type, alloc_whole_rl(get_type(arg)));
2110
2111 if (!is_whole_rl(rl))
2112 sql_insert_caller_info(expr, PARAM_VALUE, i, "$", show_rl(rl));
2113 state = get_state_expr(SMATCH_EXTRA, arg);
2114 if (estate_has_fuzzy_max(state)) {
2115 sql_insert_caller_info(expr, FUZZY_MAX, i, "$",
2116 sval_to_str(estate_get_fuzzy_max(state)));
2117 }
2118 i++;
2119 } END_FOR_EACH_PTR(arg);
2120 }
2121
2122 static void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
2123 {
2124 struct range_list *rl = NULL;
2125 struct smatch_state *state;
2126 struct symbol *type;
2127 char fullname[256];
2128
2129 if (strcmp(key, "*$") == 0)
2130 snprintf(fullname, sizeof(fullname), "*%s", name);
2131 else if (strncmp(key, "$", 1) == 0)
2132 snprintf(fullname, 256, "%s%s", name, key + 1);
2133 else
2134 return;
2135
2136 type = get_member_type_from_key(symbol_expression(sym), key);
2137 str_to_rl(type, value, &rl);
2138 state = alloc_estate_rl(rl);
2139 set_state(SMATCH_EXTRA, fullname, sym, state);
2140 }
2141
2142 static void set_param_hard_max(const char *name, struct symbol *sym, char *key, char *value)
2143 {
2144 struct range_list *rl = NULL;
2145 struct smatch_state *state;
2146 struct symbol *type;
2147 char fullname[256];
2148 sval_t max;
2149
2150 if (strcmp(key, "*$") == 0)
2151 snprintf(fullname, sizeof(fullname), "*%s", name);
2152 else if (strncmp(key, "$", 1) == 0)
2153 snprintf(fullname, 256, "%s%s", name, key + 1);
2154 else
2155 return;
2156
2157 state = get_state(SMATCH_EXTRA, fullname, sym);
2158 if (!state)
2159 return;
2160 type = get_member_type_from_key(symbol_expression(sym), key);
2161 str_to_rl(type, value, &rl);
2162 if (!rl_to_sval(rl, &max))
2163 return;
2164 estate_set_fuzzy_max(state, max);
2165 }
2166
2167 struct smatch_state *get_extra_state(struct expression *expr)
2168 {
2169 char *name;
2170 struct symbol *sym;
2171 struct smatch_state *ret = NULL;
2172 struct range_list *rl;
2173
2174 if (is_pointer(expr) && get_address_rl(expr, &rl))
2175 return alloc_estate_rl(rl);
2176
2177 name = expr_to_known_chunk_sym(expr, &sym);
2178 if (!name)
2179 goto free;
2180
2181 ret = get_state(SMATCH_EXTRA, name, sym);
2182 free:
2183 free_string(name);
2184 return ret;
2185 }
2186
2187 void register_smatch_extra(int id)
2188 {
2189 my_id = id;
2190
2191 add_merge_hook(my_id, &merge_estates);
2192 add_unmatched_state_hook(my_id, &unmatched_state);
2193 select_caller_info_hook(set_param_value, PARAM_VALUE);
2194 select_caller_info_hook(set_param_hard_max, FUZZY_MAX);
2195 select_return_states_before(&db_limited_before);
2196 select_return_states_hook(PARAM_LIMIT, &db_param_limit);
2197 select_return_states_hook(PARAM_FILTER, &db_param_filter);
2198 select_return_states_hook(PARAM_ADD, &db_param_add);
2199 select_return_states_hook(PARAM_SET, &db_param_set);
2200 select_return_states_hook(PARAM_VALUE, &db_param_value);
2201 select_return_states_after(&db_limited_after);
2202 }
2203
2204 static void match_link_modify(struct sm_state *sm, struct expression *mod_expr)
2205 {
2206 struct var_sym_list *links;
2207 struct var_sym *tmp;
2208 struct smatch_state *state;
2209
2210 links = sm->state->data;
2211
2212 FOR_EACH_PTR(links, tmp) {
2213 if (sm->sym == tmp->sym &&
2214 strcmp(sm->name, tmp->var) == 0)
2215 continue;
2216 state = get_state(SMATCH_EXTRA, tmp->var, tmp->sym);
2217 if (!state)
2218 continue;
2219 set_state(SMATCH_EXTRA, tmp->var, tmp->sym, alloc_estate_whole(estate_type(state)));
2220 } END_FOR_EACH_PTR(tmp);
2221 set_state(link_id, sm->name, sm->sym, &undefined);
2222 }
2223
2224 void register_smatch_extra_links(int id)
2225 {
2226 link_id = id;
2227 }
2228
2229 void register_smatch_extra_late(int id)
2230 {
2231 add_merge_hook(link_id, &merge_link_states);
2232 add_modification_hook(link_id, &match_link_modify);
2233 add_hook(&match_dereferences, DEREF_HOOK);
2234 add_hook(&match_pointer_as_array, OP_HOOK);
2235 select_call_implies_hook(DEREFERENCE, &set_param_dereferenced);
2236 add_hook(&match_function_call, FUNCTION_CALL_HOOK);
2237 add_hook(&match_assign, ASSIGNMENT_HOOK);
2238 add_hook(&match_assign, GLOBAL_ASSIGNMENT_HOOK);
2239 add_hook(&unop_expr, OP_HOOK);
2240 add_hook(&asm_expr, ASM_HOOK);
2241 add_untracked_param_hook(&match_untracked_array);
2242
2243 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
2244 add_member_info_callback(my_id, struct_member_callback);
2245 add_split_return_callback(&returned_struct_members);
2246
2247 add_hook(&assume_indexes_are_valid, OP_HOOK);
2248 }
Static analysis for C