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implied: add the stree_id to debug output
[smatch.git] / smatch_extra.c
blobd9475cc67532e48e6bd55fcf4e7a39f089907e2a
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 #include <stdlib.h>
24 #include <errno.h>
25 #ifndef __USE_ISOC99
26 #define __USE_ISOC99
27 #endif
28 #include <limits.h>
29 #include "parse.h"
30 #include "smatch.h"
31 #include "smatch_slist.h"
32 #include "smatch_extra.h"
33
34 static int my_id;
35
36 struct string_list *__ignored_macros = NULL;
37 static int in_warn_on_macro()
38 {
39 struct statement *stmt;
40 char *tmp;
41 char *macro;
42
43 stmt = get_current_statement();
44 if (!stmt)
45 return 0;
46 macro = get_macro_name(stmt->pos);
47 if (!macro)
48 return 0;
49
50 FOR_EACH_PTR(__ignored_macros, tmp) {
51 if (!strcmp(tmp, macro))
52 return 1;
53 } END_FOR_EACH_PTR(tmp);
54 return 0;
55 }
56
57 typedef void (mod_hook)(const char *name, struct symbol *sym, struct smatch_state *state);
58 DECLARE_PTR_LIST(void_fn_list, mod_hook *);
59 static struct void_fn_list *extra_mod_hooks;
60 void add_extra_mod_hook(mod_hook *fn)
61 {
62 mod_hook **p = malloc(sizeof(mod_hook *));
63 *p = fn;
64 add_ptr_list(&extra_mod_hooks, p);
65 }
66
67 void call_extra_mod_hooks(const char *name, struct symbol *sym, struct smatch_state *state)
68 {
69 mod_hook **fn;
70
71 FOR_EACH_PTR(extra_mod_hooks, fn) {
72 (*fn)(name, sym, state);
73 } END_FOR_EACH_PTR(fn);
74 }
75
76 struct sm_state *set_extra_mod(const char *name, struct symbol *sym, struct smatch_state *state)
77 {
78 if (in_warn_on_macro())
79 return NULL;
80 remove_from_equiv(name, sym);
81 call_extra_mod_hooks(name, sym, state);
82 return set_state(SMATCH_EXTRA, name, sym, state);
83 }
84
85 struct sm_state *set_extra_expr_mod(struct expression *expr, struct smatch_state *state)
86 {
87 struct symbol *sym;
88 char *name;
89 struct sm_state *ret = NULL;
90
91 expr = strip_expr(expr);
92 name = expr_to_var_sym(expr, &sym);
93 if (!name || !sym)
94 goto free;
95 ret = set_extra_mod(name, sym, state);
96 free:
97 free_string(name);
98 return ret;
99 }
100
101 void set_extra_nomod(const char *name, struct symbol *sym, struct smatch_state *state)
102 {
103 struct relation *rel;
104 struct smatch_state *orig_state;
105
106 orig_state = get_state(SMATCH_EXTRA, name, sym);
107
108 if (!estate_related(orig_state)) {
109 set_state(SMATCH_EXTRA, name, sym, state);
110 return;
111 }
112
113 set_related(state, estate_related(orig_state));
114 FOR_EACH_PTR(estate_related(orig_state), rel) {
115 if (option_debug_related)
116 sm_msg("updating related %s to %s", rel->name, state->name);
117 set_state(SMATCH_EXTRA, rel->name, rel->sym, state);
118 } END_FOR_EACH_PTR(rel);
119 }
120
121 /*
122 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
123 */
124 void set_extra_expr_nomod(struct expression *expr, struct smatch_state *state)
125 {
126 char *name;
127 struct symbol *sym;
128
129 name = expr_to_var_sym(expr, &sym);
130 if (!name || !sym)
131 goto free;
132 set_extra_nomod(name, sym, state);
133 free:
134 free_string(name);
135
136 }
137
138 static void set_extra_true_false(const char *name, struct symbol *sym,
139 struct smatch_state *true_state,
140 struct smatch_state *false_state)
141 {
142 struct relation *rel;
143 struct smatch_state *orig_state;
144
145 if (in_warn_on_macro())
146 return;
147
148 orig_state = get_state(SMATCH_EXTRA, name, sym);
149
150 if (!estate_related(orig_state)) {
151 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
152 return;
153 }
154
155 if (true_state)
156 set_related(true_state, estate_related(orig_state));
157 if (false_state)
158 set_related(false_state, estate_related(orig_state));
159
160 FOR_EACH_PTR(estate_related(orig_state), rel) {
161 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
162 true_state, false_state);
163 } END_FOR_EACH_PTR(rel);
164 }
165
166 static void set_extra_expr_true_false(struct expression *expr,
167 struct smatch_state *true_state,
168 struct smatch_state *false_state)
169 {
170 char *name;
171 struct symbol *sym;
172
173 expr = strip_expr(expr);
174 name = expr_to_var_sym(expr, &sym);
175 if (!name || !sym)
176 goto free;
177 set_extra_true_false(name, sym, true_state, false_state);
178 free:
179 free_string(name);
180 }
181
182 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
183 {
184 struct expression *iter_var;
185 struct expression *condition;
186 struct sm_state *sm;
187 struct smatch_state *estate;
188 sval_t start;
189
190 condition = strip_expr(loop->iterator_pre_condition);
191 if (!condition)
192 return NULL;
193 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
194 return NULL;
195 if (condition->op != SPECIAL_DECREMENT)
196 return NULL;
197
198 iter_var = condition->unop;
199 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
200 if (!sm)
201 return NULL;
202 if (sval_cmp_val(estate_min(sm->state), 0) < 0)
203 return NULL;
204 start = estate_max(sm->state);
205 if (sval_cmp_val(start, 0) <= 0)
206 return NULL;
207 if (!sval_is_max(start))
208 start.value--;
209
210 if (condition->type == EXPR_PREOP) {
211 estate = alloc_estate_range(sval_type_val(start.type, 1), start);
212 if (estate_has_hard_max(sm->state))
213 estate_set_hard_max(estate);
214 estate_copy_fuzzy_max(estate, sm->state);
215 set_extra_expr_mod(iter_var, estate);
216 }
217 if (condition->type == EXPR_POSTOP) {
218 estate = alloc_estate_range(sval_type_val(start.type, 0), start);
219 if (estate_has_hard_max(sm->state))
220 estate_set_hard_max(estate);
221 estate_copy_fuzzy_max(estate, sm->state);
222 set_extra_expr_mod(iter_var, estate);
223 }
224 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
225 }
226
227 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
228 struct expression *condition)
229 {
230 struct expression *iter_var;
231 struct sm_state *sm;
232 struct smatch_state *estate;
233 sval_t start, end, max;
234
235 iter_var = iter_expr->unop;
236 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
237 if (!sm)
238 return NULL;
239 if (!estate_get_single_value(sm->state, &start))
240 return NULL;
241 if (get_implied_max(condition->right, &end))
242 end = sval_cast(get_type(iter_var), end);
243 else
244 end = sval_type_max(get_type(iter_var));
245
246 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
247 return NULL;
248
249 switch (condition->op) {
250 case SPECIAL_UNSIGNED_LT:
251 case SPECIAL_NOTEQUAL:
252 case '<':
253 if (!sval_is_min(end))
254 end.value--;
255 break;
256 case SPECIAL_UNSIGNED_LTE:
257 case SPECIAL_LTE:
258 break;
259 default:
260 return NULL;
261 }
262 if (sval_cmp(end, start) < 0)
263 return NULL;
264 estate = alloc_estate_range(start, end);
265 if (get_hard_max(condition->right, &max)) {
266 estate_set_hard_max(estate);
267 if (condition->op == '<' ||
268 condition->op == SPECIAL_UNSIGNED_LT ||
269 condition->op == SPECIAL_NOTEQUAL)
270 max.value--;
271 estate_set_fuzzy_max(estate, max);
272 }
273 set_extra_expr_mod(iter_var, estate);
274 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
275 }
276
277 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
278 struct expression *condition)
279 {
280 struct expression *iter_var;
281 struct sm_state *sm;
282 struct smatch_state *estate;
283 sval_t start, end;
284
285 iter_var = iter_expr->unop;
286 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
287 if (!sm)
288 return NULL;
289 if (!estate_get_single_value(sm->state, &start))
290 return NULL;
291 if (!get_implied_min(condition->right, &end))
292 end = sval_type_min(get_type(iter_var));
293 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
294 return NULL;
295
296 switch (condition->op) {
297 case SPECIAL_NOTEQUAL:
298 case '>':
299 if (!sval_is_min(end) && !sval_is_max(end))
300 end.value++;
301 break;
302 case SPECIAL_GTE:
303 break;
304 default:
305 return NULL;
306 }
307 if (sval_cmp(end, start) > 0)
308 return NULL;
309 estate = alloc_estate_range(end, start);
310 estate_set_hard_max(estate);
311 estate_set_fuzzy_max(estate, estate_get_fuzzy_max(estate));
312 set_extra_expr_mod(iter_var, estate);
313 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
314 }
315
316 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
317 {
318 struct expression *iter_expr;
319 struct expression *condition;
320
321 if (!loop->iterator_post_statement)
322 return NULL;
323 if (loop->iterator_post_statement->type != STMT_EXPRESSION)
324 return NULL;
325 iter_expr = loop->iterator_post_statement->expression;
326 if (!loop->iterator_pre_condition)
327 return NULL;
328 if (loop->iterator_pre_condition->type != EXPR_COMPARE)
329 return NULL;
330 condition = loop->iterator_pre_condition;
331
332 if (iter_expr->op == SPECIAL_INCREMENT)
333 return handle_canonical_for_inc(iter_expr, condition);
334 if (iter_expr->op == SPECIAL_DECREMENT)
335 return handle_canonical_for_dec(iter_expr, condition);
336 return NULL;
337 }
338
339 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct stree **stree)
340 {
341 struct sm_state *ret;
342
343 __push_fake_cur_stree();
344 if (!loop->iterator_post_statement)
345 ret = handle_canonical_while_count_down(loop);
346 else
347 ret = handle_canonical_for_loops(loop);
348 *stree = __pop_fake_cur_stree();
349 return ret;
350 }
351
352 int __iterator_unchanged(struct sm_state *sm)
353 {
354 if (!sm)
355 return 0;
356 if (get_sm_state(my_id, sm->name, sm->sym) == sm)
357 return 1;
358 return 0;
359 }
360
361 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
362 {
363 sval_t after_value;
364
365 /* paranoid checking. prolly not needed */
366 condition = strip_expr(condition);
367 if (!condition)
368 return;
369 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
370 return;
371 if (condition->op != SPECIAL_DECREMENT)
372 return;
373 after_value = estate_min(sm->state);
374 after_value.value--;
375 set_extra_mod(sm->name, sm->sym, alloc_estate_sval(after_value));
376 }
377
378 void __extra_pre_loop_hook_after(struct sm_state *sm,
379 struct statement *iterator,
380 struct expression *condition)
381 {
382 struct expression *iter_expr;
383 sval_t limit;
384 struct smatch_state *state;
385
386 if (!iterator) {
387 while_count_down_after(sm, condition);
388 return;
389 }
390
391 iter_expr = iterator->expression;
392
393 if (condition->type != EXPR_COMPARE)
394 return;
395 if (iter_expr->op == SPECIAL_INCREMENT) {
396 limit = sval_binop(estate_max(sm->state), '+',
397 sval_type_val(estate_type(sm->state), 1));
398 } else {
399 limit = sval_binop(estate_min(sm->state), '-',
400 sval_type_val(estate_type(sm->state), 1));
401 }
402 if (!estate_has_hard_max(sm->state) && !__has_breaks()) {
403 if (iter_expr->op == SPECIAL_INCREMENT)
404 state = alloc_estate_range(estate_min(sm->state), limit);
405 else
406 state = alloc_estate_range(limit, estate_max(sm->state));
407 } else {
408 state = alloc_estate_sval(limit);
409 }
410 if (!estate_has_hard_max(sm->state)) {
411 estate_clear_hard_max(state);
412 }
413 if (estate_has_fuzzy_max(sm->state)) {
414 sval_t hmax = estate_get_fuzzy_max(sm->state);
415 sval_t max = estate_max(sm->state);
416
417 if (sval_cmp(hmax, max) != 0)
418 estate_clear_fuzzy_max(state);
419 } else if (!estate_has_fuzzy_max(sm->state)) {
420 estate_clear_fuzzy_max(state);
421 }
422
423 set_extra_mod(sm->name, sm->sym, state);
424 }
425
426 static struct stree *unmatched_stree;
427 static struct smatch_state *unmatched_state(struct sm_state *sm)
428 {
429 struct smatch_state *state;
430
431 if (unmatched_stree) {
432 state = get_state_stree(unmatched_stree, SMATCH_EXTRA, sm->name, sm->sym);
433 if (state)
434 return state;
435 }
436 return alloc_estate_whole(estate_type(sm->state));
437 }
438
439 static void clear_the_pointed_at(struct expression *expr)
440 {
441 struct stree *stree;
442 char *name;
443 struct symbol *sym;
444 struct sm_state *tmp;
445
446 name = expr_to_var_sym(expr, &sym);
447 if (!name || !sym)
448 goto free;
449
450 stree = __get_cur_stree();
451 FOR_EACH_MY_SM(SMATCH_EXTRA, stree, tmp) {
452 if (tmp->name[0] != '*')
453 continue;
454 if (tmp->sym != sym)
455 continue;
456 if (strcmp(tmp->name + 1, name) != 0)
457 continue;
458 set_extra_mod(tmp->name, tmp->sym, alloc_estate_whole(estate_type(tmp->state)));
459 } END_FOR_EACH_SM(tmp);
460
461 free:
462 free_string(name);
463 }
464
465 static void match_function_call(struct expression *expr)
466 {
467 struct expression *arg;
468 struct expression *tmp;
469
470 /* if we have the db this is handled in smatch_function_hooks.c */
471 if (!option_no_db)
472 return;
473 if (inlinable(expr->fn))
474 return;
475
476 FOR_EACH_PTR(expr->args, arg) {
477 tmp = strip_expr(arg);
478 if (tmp->type == EXPR_PREOP && tmp->op == '&')
479 set_extra_expr_mod(tmp->unop, alloc_estate_whole(get_type(tmp->unop)));
480 else
481 clear_the_pointed_at(tmp);
482 } END_FOR_EACH_PTR(arg);
483 }
484
485 static int types_equiv_or_pointer(struct symbol *one, struct symbol *two)
486 {
487 if (!one || !two)
488 return 0;
489 if (one->type == SYM_PTR && two->type == SYM_PTR)
490 return 1;
491 return types_equiv(one, two);
492 }
493
494 static void match_vanilla_assign(struct expression *left, struct expression *right)
495 {
496 struct range_list *rl = NULL;
497 struct symbol *right_sym;
498 struct symbol *left_type;
499 struct symbol *right_type;
500 char *right_name = NULL;
501 struct symbol *sym;
502 char *name;
503 sval_t max;
504 struct smatch_state *state;
505
506 name = expr_to_var_sym(left, &sym);
507 if (!name)
508 return;
509
510 left_type = get_type(left);
511 right_type = get_type(right);
512
513 right_name = expr_to_var_sym(right, &right_sym);
514 if (right_name && right_sym &&
515 types_equiv_or_pointer(left_type, right_type)) {
516 set_equiv(left, right);
517 goto free;
518 }
519
520 if (get_implied_rl(right, &rl)) {
521 rl = cast_rl(left_type, rl);
522 state = alloc_estate_rl(rl);
523 if (get_hard_max(right, &max)) {
524 estate_set_hard_max(state);
525 estate_set_fuzzy_max(state, max);
526 }
527 } else {
528 rl = alloc_whole_rl(right_type);
529 rl = cast_rl(left_type, rl);
530 state = alloc_estate_rl(rl);
531 }
532 set_extra_mod(name, sym, state);
533 free:
534 free_string(right_name);
535 }
536
537 static int op_remove_assign(int op)
538 {
539 switch (op) {
540 case SPECIAL_ADD_ASSIGN:
541 return '+';
542 case SPECIAL_SUB_ASSIGN:
543 return '-';
544 case SPECIAL_MUL_ASSIGN:
545 return '*';
546 case SPECIAL_DIV_ASSIGN:
547 return '/';
548 case SPECIAL_MOD_ASSIGN:
549 return '%';
550 case SPECIAL_AND_ASSIGN:
551 return '&';
552 case SPECIAL_OR_ASSIGN:
553 return '|';
554 case SPECIAL_XOR_ASSIGN:
555 return '^';
556 case SPECIAL_SHL_ASSIGN:
557 return SPECIAL_LEFTSHIFT;
558 case SPECIAL_SHR_ASSIGN:
559 return SPECIAL_RIGHTSHIFT;
560 default:
561 return op;
562 }
563 }
564
565 static void match_assign(struct expression *expr)
566 {
567 struct range_list *rl = NULL;
568 struct expression *left;
569 struct expression *right;
570 struct expression *binop_expr;
571 struct symbol *left_type;
572 struct symbol *right_type;
573 struct symbol *sym;
574 char *name;
575 sval_t left_min, left_max;
576 sval_t right_min, right_max;
577 sval_t res_min, res_max;
578
579 left = strip_expr(expr->left);
580
581 right = strip_expr(expr->right);
582 while (right->type == EXPR_ASSIGNMENT && right->op == '=')
583 right = strip_expr(right->left);
584
585 if (is_condition(expr->right))
586 return; /* handled in smatch_condition.c */
587 if (expr->op == '=' && right->type == EXPR_CALL)
588 return; /* handled in smatch_function_hooks.c */
589 if (expr->op == '=') {
590 match_vanilla_assign(left, right);
591 return;
592 }
593
594 name = expr_to_var_sym(left, &sym);
595 if (!name)
596 return;
597
598 left_type = get_type(left);
599 right_type = get_type(right);
600
601 res_min = sval_type_min(left_type);
602 res_max = sval_type_max(left_type);
603
604 switch (expr->op) {
605 case SPECIAL_ADD_ASSIGN:
606 get_absolute_max(left, &left_max);
607 get_absolute_max(right, &right_max);
608 if (sval_binop_overflows(left_max, '+', right_max))
609 break;
610 if (get_implied_min(left, &left_min) &&
611 !sval_is_negative_min(left_min) &&
612 get_implied_min(right, &right_min) &&
613 !sval_is_negative_min(right_min)) {
614 res_min = sval_binop(left_min, '+', right_min);
615 res_min = sval_cast(right_type, res_min);
616 }
617 if (inside_loop()) /* we are assuming loops don't lead to wrapping */
618 break;
619 res_max = sval_binop(left_max, '+', right_max);
620 res_max = sval_cast(right_type, res_max);
621 break;
622 case SPECIAL_SUB_ASSIGN:
623 if (get_implied_max(left, &left_max) &&
624 !sval_is_max(left_max) &&
625 get_implied_min(right, &right_min) &&
626 !sval_is_min(right_min)) {
627 res_max = sval_binop(left_max, '-', right_min);
628 res_max = sval_cast(right_type, res_max);
629 }
630 if (inside_loop())
631 break;
632 if (get_implied_min(left, &left_min) &&
633 !sval_is_min(left_min) &&
634 get_implied_max(right, &right_max) &&
635 !sval_is_max(right_max)) {
636 res_min = sval_binop(left_min, '-', right_max);
637 res_min = sval_cast(right_type, res_min);
638 }
639 break;
640 case SPECIAL_AND_ASSIGN:
641 case SPECIAL_MOD_ASSIGN:
642 case SPECIAL_SHL_ASSIGN:
643 case SPECIAL_SHR_ASSIGN:
644 case SPECIAL_OR_ASSIGN:
645 case SPECIAL_XOR_ASSIGN:
646 case SPECIAL_MUL_ASSIGN:
647 case SPECIAL_DIV_ASSIGN:
648 binop_expr = binop_expression(expr->left,
649 op_remove_assign(expr->op),
650 expr->right);
651 if (get_absolute_rl(binop_expr, &rl)) {
652 rl = cast_rl(left_type, rl);
653 set_extra_mod(name, sym, alloc_estate_rl(rl));
654 goto free;
655 }
656 break;
657 }
658 rl = cast_rl(left_type, alloc_rl(res_min, res_max));
659 set_extra_mod(name, sym, alloc_estate_rl(rl));
660 free:
661 free_string(name);
662 }
663
664 static struct smatch_state *increment_state(struct smatch_state *state)
665 {
666 sval_t min = estate_min(state);
667 sval_t max = estate_max(state);
668
669 if (!estate_rl(state))
670 return NULL;
671
672 if (inside_loop())
673 max = sval_type_max(max.type);
674
675 if (!sval_is_min(min) && !sval_is_max(min))
676 min.value++;
677 if (!sval_is_min(max) && !sval_is_max(max))
678 max.value++;
679 return alloc_estate_range(min, max);
680 }
681
682 static struct smatch_state *decrement_state(struct smatch_state *state)
683 {
684 sval_t min = estate_min(state);
685 sval_t max = estate_max(state);
686
687 if (!estate_rl(state))
688 return NULL;
689
690 if (inside_loop())
691 min = sval_type_min(min.type);
692
693 if (!sval_is_min(min) && !sval_is_max(min))
694 min.value--;
695 if (!sval_is_min(max) && !sval_is_max(max))
696 max.value--;
697 return alloc_estate_range(min, max);
698 }
699
700 static void unop_expr(struct expression *expr)
701 {
702 struct smatch_state *state;
703
704 if (expr->smatch_flags & Handled)
705 return;
706
707 switch (expr->op) {
708 case SPECIAL_INCREMENT:
709 state = get_state_expr(SMATCH_EXTRA, expr->unop);
710 state = increment_state(state);
711 if (!state)
712 state = alloc_estate_whole(get_type(expr));
713 set_extra_expr_mod(expr->unop, state);
714 break;
715 case SPECIAL_DECREMENT:
716 state = get_state_expr(SMATCH_EXTRA, expr->unop);
717 state = decrement_state(state);
718 if (!state)
719 state = alloc_estate_whole(get_type(expr));
720 set_extra_expr_mod(expr->unop, state);
721 break;
722 default:
723 return;
724 }
725 }
726
727 static void asm_expr(struct statement *stmt)
728 {
729
730 struct expression *expr;
731 struct symbol *type;
732 int state = 0;
733
734 FOR_EACH_PTR(stmt->asm_outputs, expr) {
735 switch (state) {
736 case 0: /* identifier */
737 case 1: /* constraint */
738 state++;
739 continue;
740 case 2: /* expression */
741 state = 0;
742 type = get_type(strip_expr(expr));
743 set_extra_expr_mod(expr, alloc_estate_whole(type));
744 continue;
745 }
746 } END_FOR_EACH_PTR(expr);
747 }
748
749 static void delete_state_tracker(struct tracker *t)
750 {
751 remove_from_equiv(t->name, t->sym);
752 delete_state(t->owner, t->name, t->sym);
753 }
754
755 static void scoped_state_extra(const char *name, struct symbol *sym)
756 {
757 struct tracker *t;
758
759 t = alloc_tracker(SMATCH_EXTRA, name, sym);
760 add_scope_hook((scope_hook *)&delete_state_tracker, t);
761 }
762
763 static void match_declarations(struct symbol *sym)
764 {
765 const char *name;
766
767 if (sym->ident) {
768 name = sym->ident->name;
769 if (!sym->initializer) {
770 set_state(SMATCH_EXTRA, name, sym, alloc_estate_whole(get_real_base_type(sym)));
771 scoped_state_extra(name, sym);
772 }
773 }
774 }
775
776 static void check_dereference(struct expression *expr)
777 {
778 if (outside_of_function())
779 return;
780 set_extra_expr_nomod(expr, alloc_estate_range(valid_ptr_min_sval, valid_ptr_max_sval));
781 }
782
783 static void match_dereferences(struct expression *expr)
784 {
785 if (expr->type != EXPR_PREOP)
786 return;
787 check_dereference(expr->unop);
788 }
789
790 static void match_pointer_as_array(struct expression *expr)
791 {
792 if (!is_array(expr))
793 return;
794 check_dereference(expr->unop->left);
795 }
796
797 static void set_param_dereferenced(struct expression *arg, char *unused)
798 {
799 check_dereference(arg);
800 }
801
802 static void match_function_def(struct symbol *sym)
803 {
804 struct symbol *arg;
805
806 FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
807 if (!arg->ident)
808 continue;
809 set_state(my_id, arg->ident->name, arg, alloc_estate_whole(get_real_base_type(arg)));
810 } END_FOR_EACH_PTR(arg);
811 }
812
813 static sval_t add_one(sval_t sval)
814 {
815 sval.value++;
816 return sval;
817 }
818
819 static sval_t sub_one(sval_t sval)
820 {
821 sval.value--;
822 return sval;
823 }
824
825 static void handle_comparison(struct symbol *type, struct expression *left, int op, struct expression *right)
826 {
827 struct range_list *left_orig;
828 struct range_list *left_true;
829 struct range_list *left_false;
830 struct range_list *right_orig;
831 struct range_list *right_true;
832 struct range_list *right_false;
833 struct smatch_state *left_true_state;
834 struct smatch_state *left_false_state;
835 struct smatch_state *right_true_state;
836 struct smatch_state *right_false_state;
837 sval_t min, max, dummy, hard_max;
838 int left_postop = 0;
839 int right_postop = 0;
840
841 if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
842 if (left->type == EXPR_POSTOP) {
843 left->smatch_flags |= Handled;
844 left_postop = left->op;
845 }
846 left = strip_expr(left->unop);
847 }
848 while (left->type == EXPR_ASSIGNMENT)
849 left = strip_expr(left->left);
850
851 if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
852 if (right->type == EXPR_POSTOP) {
853 right->smatch_flags |= Handled;
854 right_postop = right->op;
855 }
856 right = strip_expr(right->unop);
857 }
858
859 if (get_implied_rl(left, &left_orig)) {
860 left_orig = cast_rl(type, left_orig);
861 } else {
862 min = sval_type_min(get_type(left));
863 max = sval_type_max(get_type(left));
864 left_orig = cast_rl(type, alloc_rl(min, max));
865 }
866
867 if (get_implied_rl(right, &right_orig)) {
868 right_orig = cast_rl(type, right_orig);
869 } else {
870 min = sval_type_min(get_type(right));
871 max = sval_type_max(get_type(right));
872 right_orig = cast_rl(type, alloc_rl(min, max));
873 }
874 min = sval_type_min(type);
875 max = sval_type_max(type);
876
877 left_true = clone_rl(left_orig);
878 left_false = clone_rl(left_orig);
879 right_true = clone_rl(right_orig);
880 right_false = clone_rl(right_orig);
881
882 switch (op) {
883 case '<':
884 case SPECIAL_UNSIGNED_LT:
885 left_true = remove_range(left_orig, rl_max(right_orig), max);
886 if (!sval_is_min(rl_min(right_orig))) {
887 left_false = remove_range(left_orig, min, sub_one(rl_min(right_orig)));
888 }
889
890 right_true = remove_range(right_orig, min, rl_min(left_orig));
891 if (!sval_is_max(rl_max(left_orig)))
892 right_false = remove_range(right_orig, add_one(rl_max(left_orig)), max);
893 break;
894 case SPECIAL_UNSIGNED_LTE:
895 case SPECIAL_LTE:
896 if (!sval_is_max(rl_max(right_orig)))
897 left_true = remove_range(left_orig, add_one(rl_max(right_orig)), max);
898 left_false = remove_range(left_orig, min, rl_min(right_orig));
899
900 if (!sval_is_min(rl_min(left_orig)))
901 right_true = remove_range(right_orig, min, sub_one(rl_min(left_orig)));
902 right_false = remove_range(right_orig, rl_max(left_orig), max);
903
904 if (sval_cmp(rl_min(left_orig), rl_min(right_orig)) == 0)
905 left_false = remove_range(left_false, rl_min(left_orig), rl_min(left_orig));
906 if (sval_cmp(rl_max(left_orig), rl_max(right_orig)) == 0)
907 right_false = remove_range(right_false, rl_max(left_orig), rl_max(left_orig));
908 break;
909 case SPECIAL_EQUAL:
910 if (!sval_is_max(rl_max(right_orig))) {
911 left_true = remove_range(left_true, add_one(rl_max(right_orig)), max);
912 }
913 if (!sval_is_min(rl_min(right_orig))) {
914 left_true = remove_range(left_true, min, sub_one(rl_min(right_orig)));
915 }
916 if (sval_cmp(rl_min(right_orig), rl_max(right_orig)) == 0)
917 left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
918
919 if (!sval_is_max(rl_max(left_orig)))
920 right_true = remove_range(right_true, add_one(rl_max(left_orig)), max);
921 if (!sval_is_min(rl_min(left_orig)))
922 right_true = remove_range(right_true, min, sub_one(rl_min(left_orig)));
923 if (sval_cmp(rl_min(left_orig), rl_max(left_orig)) == 0)
924 right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
925 break;
926 case SPECIAL_UNSIGNED_GTE:
927 case SPECIAL_GTE:
928 if (!sval_is_min(rl_min(right_orig)))
929 left_true = remove_range(left_orig, min, sub_one(rl_min(right_orig)));
930 left_false = remove_range(left_orig, rl_max(right_orig), max);
931
932 if (!sval_is_max(rl_max(left_orig)))
933 right_true = remove_range(right_orig, add_one(rl_max(left_orig)), max);
934 right_false = remove_range(right_orig, min, rl_min(left_orig));
935
936 if (sval_cmp(rl_min(left_orig), rl_min(right_orig)) == 0)
937 right_false = remove_range(right_false, rl_min(left_orig), rl_min(left_orig));
938 if (sval_cmp(rl_max(left_orig), rl_max(right_orig)) == 0)
939 left_false = remove_range(left_false, rl_max(left_orig), rl_max(left_orig));
940 break;
941 case '>':
942 case SPECIAL_UNSIGNED_GT:
943 left_true = remove_range(left_orig, min, rl_min(right_orig));
944 if (!sval_is_max(rl_max(right_orig)))
945 left_false = remove_range(left_orig, add_one(rl_max(right_orig)), max);
946
947 right_true = remove_range(right_orig, rl_max(left_orig), max);
948 if (!sval_is_min(rl_min(left_orig)))
949 right_false = remove_range(right_orig, min, sub_one(rl_min(left_orig)));
950 break;
951 case SPECIAL_NOTEQUAL:
952 if (!sval_is_max(rl_max(right_orig)))
953 left_false = remove_range(left_false, add_one(rl_max(right_orig)), max);
954 if (!sval_is_min(rl_min(right_orig)))
955 left_false = remove_range(left_false, min, sub_one(rl_min(right_orig)));
956 if (sval_cmp(rl_min(right_orig), rl_max(right_orig)) == 0)
957 left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
958
959 if (!sval_is_max(rl_max(left_orig)))
960 right_false = remove_range(right_false, add_one(rl_max(left_orig)), max);
961 if (!sval_is_min(rl_min(left_orig)))
962 right_false = remove_range(right_false, min, sub_one(rl_min(left_orig)));
963 if (sval_cmp(rl_min(left_orig), rl_max(left_orig)) == 0)
964 right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
965 break;
966 default:
967 return;
968 }
969
970 left_true = rl_truncate_cast(get_type(left), left_true);
971 left_false = rl_truncate_cast(get_type(left), left_false);
972 right_true = rl_truncate_cast(get_type(right), right_true);
973 right_false = rl_truncate_cast(get_type(right), right_false);
974
975 left_true_state = alloc_estate_rl(left_true);
976 left_false_state = alloc_estate_rl(left_false);
977 right_true_state = alloc_estate_rl(right_true);
978 right_false_state = alloc_estate_rl(right_false);
979
980 switch (op) {
981 case '<':
982 case SPECIAL_UNSIGNED_LT:
983 case SPECIAL_UNSIGNED_LTE:
984 case SPECIAL_LTE:
985 if (get_hard_max(right, &dummy))
986 estate_set_hard_max(left_true_state);
987 if (get_hard_max(left, &dummy))
988 estate_set_hard_max(right_false_state);
989 break;
990 case '>':
991 case SPECIAL_UNSIGNED_GT:
992 case SPECIAL_UNSIGNED_GTE:
993 case SPECIAL_GTE:
994 if (get_hard_max(left, &dummy))
995 estate_set_hard_max(right_true_state);
996 if (get_hard_max(right, &dummy))
997 estate_set_hard_max(left_false_state);
998 break;
999 }
1000
1001 switch (op) {
1002 case '<':
1003 case SPECIAL_UNSIGNED_LT:
1004 case SPECIAL_UNSIGNED_LTE:
1005 case SPECIAL_LTE:
1006 if (get_hard_max(right, &hard_max)) {
1007 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1008 hard_max.value--;
1009 estate_set_fuzzy_max(left_true_state, hard_max);
1010 }
1011 if (get_implied_value(right, &hard_max)) {
1012 if (op == SPECIAL_UNSIGNED_LTE ||
1013 op == SPECIAL_LTE)
1014 hard_max.value++;
1015 estate_set_fuzzy_max(left_false_state, hard_max);
1016 }
1017 if (get_hard_max(left, &hard_max)) {
1018 if (op == SPECIAL_UNSIGNED_LTE ||
1019 op == SPECIAL_LTE)
1020 hard_max.value--;
1021 estate_set_fuzzy_max(right_false_state, hard_max);
1022 }
1023 if (get_implied_value(left, &hard_max)) {
1024 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1025 hard_max.value++;
1026 estate_set_fuzzy_max(right_true_state, hard_max);
1027 }
1028 break;
1029 case '>':
1030 case SPECIAL_UNSIGNED_GT:
1031 case SPECIAL_UNSIGNED_GTE:
1032 case SPECIAL_GTE:
1033 if (get_hard_max(left, &hard_max)) {
1034 if (op == '>' || op == SPECIAL_UNSIGNED_GT)
1035 hard_max.value--;
1036 estate_set_fuzzy_max(right_true_state, hard_max);
1037 }
1038 if (get_implied_value(left, &hard_max)) {
1039 if (op == SPECIAL_UNSIGNED_GTE ||
1040 op == SPECIAL_GTE)
1041 hard_max.value++;
1042 estate_set_fuzzy_max(right_false_state, hard_max);
1043 }
1044 if (get_hard_max(right, &hard_max)) {
1045 if (op == SPECIAL_UNSIGNED_LTE ||
1046 op == SPECIAL_LTE)
1047 hard_max.value--;
1048 estate_set_fuzzy_max(left_false_state, hard_max);
1049 }
1050 if (get_implied_value(right, &hard_max)) {
1051 if (op == '>' ||
1052 op == SPECIAL_UNSIGNED_GT)
1053 hard_max.value++;
1054 estate_set_fuzzy_max(left_true_state, hard_max);
1055 }
1056 break;
1057 case SPECIAL_EQUAL:
1058 if (get_hard_max(left, &hard_max))
1059 estate_set_fuzzy_max(right_true_state, hard_max);
1060 if (get_hard_max(right, &hard_max))
1061 estate_set_fuzzy_max(left_true_state, hard_max);
1062 break;
1063 }
1064
1065 if (get_hard_max(left, &hard_max)) {
1066 estate_set_hard_max(left_true_state);
1067 estate_set_hard_max(left_false_state);
1068 }
1069 if (get_hard_max(right, &hard_max)) {
1070 estate_set_hard_max(right_true_state);
1071 estate_set_hard_max(right_false_state);
1072 }
1073
1074 if (left_postop == SPECIAL_INCREMENT) {
1075 left_true_state = increment_state(left_true_state);
1076 left_false_state = increment_state(left_false_state);
1077 }
1078 if (left_postop == SPECIAL_DECREMENT) {
1079 left_true_state = decrement_state(left_true_state);
1080 left_false_state = decrement_state(left_false_state);
1081 }
1082 if (right_postop == SPECIAL_INCREMENT) {
1083 right_true_state = increment_state(right_true_state);
1084 right_false_state = increment_state(right_false_state);
1085 }
1086 if (right_postop == SPECIAL_DECREMENT) {
1087 right_true_state = decrement_state(right_true_state);
1088 right_false_state = decrement_state(right_false_state);
1089 }
1090
1091 set_extra_expr_true_false(left, left_true_state, left_false_state);
1092 set_extra_expr_true_false(right, right_true_state, right_false_state);
1093 }
1094
1095 static int opposite_op(int op)
1096 {
1097 switch (op) {
1098 case '+':
1099 return '-';
1100 case '-':
1101 return '+';
1102 }
1103 return 0;
1104 }
1105
1106 static int is_simple_math(struct expression *expr)
1107 {
1108 if (!expr)
1109 return 0;
1110 if (expr->type != EXPR_BINOP)
1111 return 0;
1112 if (!opposite_op(expr->op))
1113 return 0;
1114 return 1;
1115 }
1116
1117 static void move_known_values(struct expression **left_p, struct expression **right_p)
1118 {
1119 struct expression *left = *left_p;
1120 struct expression *right = *right_p;
1121 sval_t sval;
1122
1123 if (get_implied_value(left, &sval)) {
1124 if (!is_simple_math(right))
1125 return;
1126 if (right->op == '+' && get_value(right->left, &sval)) {
1127 *left_p = binop_expression(left, opposite_op(right->op), right->left);
1128 *right_p = right->right;
1129 return;
1130 }
1131 if (get_value(right->right, &sval)) {
1132 *left_p = binop_expression(left, opposite_op(right->op), right->right);
1133 *right_p = right->left;
1134 return;
1135 }
1136 return;
1137 }
1138 if (get_implied_value(right, &sval)) {
1139 if (!is_simple_math(left))
1140 return;
1141 if (left->op == '+' && get_value(left->left, &sval)) {
1142 *right_p = binop_expression(right, opposite_op(left->op), left->left);
1143 *left_p = left->right;
1144 return;
1145 }
1146
1147 if (get_value(left->right, &sval)) {
1148 *right_p = binop_expression(right, opposite_op(left->op), left->right);
1149 *left_p = left->left;
1150 return;
1151 }
1152 return;
1153 }
1154 }
1155
1156 static int match_func_comparison(struct expression *expr)
1157 {
1158 struct expression *left = strip_expr(expr->left);
1159 struct expression *right = strip_expr(expr->right);
1160 sval_t sval;
1161
1162 /*
1163 * fixme: think about this harder. We should always be trying to limit
1164 * the non-call side as well. If we can't determine the limitter does
1165 * that mean we aren't querying the database and are missing important
1166 * information?
1167 */
1168
1169 if (left->type == EXPR_CALL) {
1170 if (get_implied_value(left, &sval)) {
1171 handle_comparison(get_type(expr), left, expr->op, right);
1172 return 1;
1173 }
1174 if (!get_implied_value(right, &sval))
1175 return 1;
1176 function_comparison(expr->op, left, sval, 1);
1177 return 1;
1178 }
1179
1180 if (right->type == EXPR_CALL) {
1181 if (get_implied_value(right, &sval)) {
1182 handle_comparison(get_type(expr), left, expr->op, right);
1183 return 1;
1184 }
1185 if (!get_implied_value(left, &sval))
1186 return 1;
1187 function_comparison(expr->op, right, sval, 0);
1188 return 1;
1189 }
1190
1191 return 0;
1192 }
1193
1194 static void match_comparison(struct expression *expr)
1195 {
1196 struct expression *left_orig = strip_expr(expr->left);
1197 struct expression *right_orig = strip_expr(expr->right);
1198 struct expression *left, *right;
1199 struct expression *prev;
1200 struct symbol *type;
1201
1202 if (match_func_comparison(expr))
1203 return;
1204
1205 type = get_type(expr);
1206 if (!type)
1207 type = &llong_ctype;
1208
1209 left = left_orig;
1210 right = right_orig;
1211 move_known_values(&left, &right);
1212 handle_comparison(type, left, expr->op, right);
1213
1214 prev = get_assigned_expr(left_orig);
1215 if (is_simple_math(prev) && has_variable(prev, left_orig) == 0) {
1216 left = prev;
1217 right = right_orig;
1218 move_known_values(&left, &right);
1219 handle_comparison(type, left, expr->op, right);
1220 }
1221
1222 prev = get_assigned_expr(right_orig);
1223 if (is_simple_math(prev) && has_variable(prev, right_orig) == 0) {
1224 left = left_orig;
1225 right = prev;
1226 move_known_values(&left, &right);
1227 handle_comparison(type, left, expr->op, right);
1228 }
1229 }
1230
1231 static void handle_AND_condition(struct expression *expr)
1232 {
1233 struct range_list *rl = NULL;
1234 sval_t known;
1235
1236 if (get_implied_value(expr->left, &known) && known.value > 0) {
1237 known.value--;
1238 get_absolute_rl(expr->right, &rl);
1239 rl = remove_range(rl, sval_type_val(known.type, 0), known);
1240 set_extra_expr_true_false(expr->right, alloc_estate_rl(rl), NULL);
1241 return;
1242 }
1243
1244 if (get_implied_value(expr->right, &known) && known.value > 0) {
1245 known.value--;
1246 get_absolute_rl(expr->left, &rl);
1247 rl = remove_range(rl, sval_type_val(known.type, 0), known);
1248 set_extra_expr_true_false(expr->left, alloc_estate_rl(rl), NULL);
1249 return;
1250 }
1251 }
1252
1253 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
1254 void __extra_match_condition(struct expression *expr)
1255 {
1256 struct symbol *sym;
1257 char *name;
1258 struct smatch_state *pre_state;
1259 struct smatch_state *true_state;
1260 struct smatch_state *false_state;
1261
1262 expr = strip_expr(expr);
1263 switch (expr->type) {
1264 case EXPR_CALL:
1265 function_comparison(SPECIAL_NOTEQUAL, expr, ll_to_sval(0), 1);
1266 return;
1267 case EXPR_PREOP:
1268 case EXPR_SYMBOL:
1269 case EXPR_DEREF: {
1270 sval_t zero;
1271
1272 zero = sval_blank(expr);
1273 zero.value = 0;
1274
1275 name = expr_to_var_sym(expr, &sym);
1276 if (!name)
1277 return;
1278 pre_state = get_state(my_id, name, sym);
1279 true_state = estate_filter_sval(pre_state, zero);
1280 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
1281 false_state = alloc_estate_sval(zero);
1282 else
1283 false_state = alloc_estate_empty();
1284 set_extra_true_false(name, sym, true_state, false_state);
1285 free_string(name);
1286 return;
1287 }
1288 case EXPR_COMPARE:
1289 match_comparison(expr);
1290 return;
1291 case EXPR_ASSIGNMENT:
1292 __extra_match_condition(expr->left);
1293 return;
1294 case EXPR_BINOP:
1295 if (expr->op == '&')
1296 handle_AND_condition(expr);
1297 return;
1298 }
1299 }
1300
1301 static void assume_indexes_are_valid(struct expression *expr)
1302 {
1303 struct expression *array_expr;
1304 int array_size;
1305 struct expression *offset;
1306 struct symbol *offset_type;
1307 struct range_list *rl_before;
1308 struct range_list *rl_after;
1309 struct range_list *filter = NULL;
1310 sval_t size;
1311
1312 expr = strip_expr(expr);
1313 if (!is_array(expr))
1314 return;
1315
1316 offset = get_array_offset(expr);
1317 offset_type = get_type(offset);
1318 if (offset_type && type_signed(offset_type)) {
1319 filter = alloc_rl(sval_type_min(offset_type),
1320 sval_type_val(offset_type, -1));
1321 }
1322
1323 array_expr = strip_parens(expr->unop->left);
1324 array_size = get_real_array_size(array_expr);
1325 if (array_size > 1) {
1326 size = sval_type_val(offset_type, array_size);
1327 add_range(&filter, size, sval_type_max(offset_type));
1328 }
1329
1330 if (!filter)
1331 return;
1332 get_absolute_rl(offset, &rl_before);
1333 rl_after = rl_filter(rl_before, filter);
1334 if (rl_equiv(rl_before, rl_after))
1335 return;
1336 set_extra_expr_nomod(offset, alloc_estate_rl(rl_after));
1337 }
1338
1339 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
1340 int implied_not_equal(struct expression *expr, long long val)
1341 {
1342 return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
1343 }
1344
1345 static void struct_member_callback(struct expression *call, int param, char *printed_name, struct smatch_state *state)
1346 {
1347 if (estate_is_whole(state))
1348 return;
1349 sql_insert_caller_info(call, PARAM_VALUE, param, printed_name, state->name);
1350 if (estate_has_fuzzy_max(state))
1351 sql_insert_caller_info(call, FUZZY_MAX, param, printed_name,
1352 sval_to_str(estate_get_fuzzy_max(state)));
1353 }
1354
1355 static void db_limited_before(void)
1356 {
1357 unmatched_stree = clone_stree(__get_cur_stree());
1358 }
1359
1360 static void db_limited_after(void)
1361 {
1362 free_stree(&unmatched_stree);
1363 }
1364
1365 static void db_param_limit_filter(struct expression *expr, int param, char *key, char *value, int mod)
1366 {
1367 struct expression *arg;
1368 char *name;
1369 struct symbol *sym;
1370 struct sm_state *sm;
1371 struct symbol *type;
1372 struct range_list *rl;
1373 struct range_list *limit;
1374 struct range_list *new;
1375
1376 while (expr->type == EXPR_ASSIGNMENT)
1377 expr = strip_expr(expr->right);
1378 if (expr->type != EXPR_CALL)
1379 return;
1380
1381 arg = get_argument_from_call_expr(expr->args, param);
1382 if (!arg)
1383 return;
1384
1385 name = get_variable_from_key(arg, key, &sym);
1386 if (!name || !sym)
1387 goto free;
1388
1389 sm = get_sm_state(SMATCH_EXTRA, name, sym);
1390 type = get_member_type_from_key(arg, key);
1391 if (sm)
1392 rl = estate_rl(sm->state);
1393 else
1394 rl = alloc_whole_rl(type);
1395
1396 call_results_to_rl(expr, type, value, &limit);
1397 new = rl_intersection(rl, limit);
1398
1399 /* We want to preserve the implications here */
1400 if (sm && rl_equiv(estate_rl(sm->state), new)) {
1401 __set_sm(sm);
1402 } else {
1403 if (mod)
1404 set_extra_mod(name, sym, alloc_estate_rl(new));
1405 else
1406 set_extra_nomod(name, sym, alloc_estate_rl(new));
1407 }
1408
1409 free:
1410 free_string(name);
1411 }
1412
1413 static void db_param_limit(struct expression *expr, int param, char *key, char *value)
1414 {
1415 db_param_limit_filter(expr, param, key, value, 0);
1416 }
1417
1418 static void db_param_filter(struct expression *expr, int param, char *key, char *value)
1419 {
1420 db_param_limit_filter(expr, param, key, value, 1);
1421 }
1422
1423 static void db_param_add(struct expression *expr, int param, char *key, char *value)
1424 {
1425 struct expression *arg;
1426 char *name;
1427 struct symbol *sym;
1428 struct symbol *type;
1429 struct smatch_state *state;
1430 struct range_list *added = NULL;
1431 struct range_list *new;
1432
1433 while (expr->type == EXPR_ASSIGNMENT)
1434 expr = strip_expr(expr->right);
1435 if (expr->type != EXPR_CALL)
1436 return;
1437
1438 arg = get_argument_from_call_expr(expr->args, param);
1439 if (!arg)
1440 return;
1441 name = get_variable_from_key(arg, key, &sym);
1442 if (!name || !sym)
1443 goto free;
1444
1445 type = get_member_type_from_key(arg, key);
1446 state = get_state(SMATCH_EXTRA, name, sym);
1447 if (state) {
1448 call_results_to_rl(expr, type, value, &added);
1449 new = rl_union(estate_rl(state), added);
1450 } else {
1451 new = alloc_whole_rl(type);
1452 }
1453
1454 set_extra_mod(name, sym, alloc_estate_rl(new));
1455 free:
1456 free_string(name);
1457 }
1458
1459 static void db_returned_member_info(struct expression *expr, int param, char *key, char *value)
1460 {
1461 struct symbol *type;
1462 struct symbol *sym;
1463 char *name;
1464 struct range_list *rl;
1465
1466 if (expr->type != EXPR_ASSIGNMENT)
1467 return;
1468
1469 name = return_state_to_var_sym(expr, param, key, &sym);
1470 if (!name || !sym)
1471 goto free;
1472 type = get_member_type_from_key(expr->left, key);
1473 if (!type)
1474 return;
1475 call_results_to_rl(expr->right, type, value, &rl);
1476 set_extra_mod(name, sym, alloc_estate_rl(rl));
1477
1478 free:
1479 free_string(name);
1480 }
1481
1482 static void returned_member_callback(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state)
1483 {
1484 if (estate_is_whole(state))
1485 return;
1486
1487 /* these are handled in smatch_param_filter/set/limit.c */
1488 if (printed_name[0] != '*' &&
1489 !strchr(printed_name, '.') && !strchr(printed_name, '-'))
1490 return;
1491
1492 sql_insert_return_states(return_id, return_ranges, RETURN_VALUE, -1,
1493 printed_name, state->name);
1494 }
1495
1496 static void match_call_info(struct expression *expr)
1497 {
1498 struct smatch_state *state;
1499 struct range_list *rl = NULL;
1500 struct expression *arg;
1501 struct symbol *type;
1502 int i = 0;
1503
1504 FOR_EACH_PTR(expr->args, arg) {
1505 type = get_arg_type(expr->fn, i);
1506
1507 if (get_implied_rl(arg, &rl))
1508 rl = cast_rl(type, rl);
1509 else
1510 rl = cast_rl(type, alloc_whole_rl(get_type(arg)));
1511
1512 if (!is_whole_rl(rl))
1513 sql_insert_caller_info(expr, PARAM_VALUE, i, "$$", show_rl(rl));
1514 state = get_state_expr(SMATCH_EXTRA, arg);
1515 if (estate_has_fuzzy_max(state)) {
1516 sql_insert_caller_info(expr, FUZZY_MAX, i, "$$",
1517 sval_to_str(estate_get_fuzzy_max(state)));
1518 }
1519 i++;
1520 } END_FOR_EACH_PTR(arg);
1521 }
1522
1523 static void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
1524 {
1525 struct range_list *rl = NULL;
1526 struct smatch_state *state;
1527 struct symbol *type;
1528 char fullname[256];
1529
1530 if (strcmp(key, "*$$") == 0)
1531 snprintf(fullname, sizeof(fullname), "*%s", name);
1532 else if (strncmp(key, "$$", 2) == 0)
1533 snprintf(fullname, 256, "%s%s", name, key + 2);
1534 else
1535 return;
1536
1537 type = get_member_type_from_key(symbol_expression(sym), key);
1538 str_to_rl(type, value, &rl);
1539 state = alloc_estate_rl(rl);
1540 set_state(SMATCH_EXTRA, fullname, sym, state);
1541 }
1542
1543 static void set_param_hard_max(const char *name, struct symbol *sym, char *key, char *value)
1544 {
1545 struct range_list *rl = NULL;
1546 struct smatch_state *state;
1547 struct symbol *type;
1548 char fullname[256];
1549 sval_t max;
1550
1551 if (strcmp(key, "*$$") == 0)
1552 snprintf(fullname, sizeof(fullname), "*%s", name);
1553 else if (strncmp(key, "$$", 2) == 0)
1554 snprintf(fullname, 256, "%s%s", name, key + 2);
1555 else
1556 return;
1557
1558 state = get_state(SMATCH_EXTRA, fullname, sym);
1559 if (!state)
1560 return;
1561 type = get_member_type_from_key(symbol_expression(sym), key);
1562 str_to_rl(type, value, &rl);
1563 if (!rl_to_sval(rl, &max))
1564 return;
1565 estate_set_fuzzy_max(state, max);
1566 }
1567
1568 void register_smatch_extra(int id)
1569 {
1570 my_id = id;
1571
1572 add_merge_hook(my_id, &merge_estates);
1573 add_unmatched_state_hook(my_id, &unmatched_state);
1574 add_hook(&match_function_def, FUNC_DEF_HOOK);
1575 add_hook(&match_declarations, DECLARATION_HOOK);
1576 select_caller_info_hook(set_param_value, PARAM_VALUE);
1577 select_caller_info_hook(set_param_hard_max, FUZZY_MAX);
1578 select_return_states_hook(RETURN_VALUE, &db_returned_member_info);
1579 select_return_states_before(&db_limited_before);
1580 select_return_states_hook(LIMITED_VALUE, &db_param_limit);
1581 select_return_states_hook(FILTER_VALUE, &db_param_filter);
1582 select_return_states_hook(ADDED_VALUE, &db_param_add);
1583 select_return_states_after(&db_limited_after);
1584 }
1585
1586 void register_smatch_extra_late(int id)
1587 {
1588 add_hook(&match_dereferences, DEREF_HOOK);
1589 add_hook(&match_pointer_as_array, OP_HOOK);
1590 select_call_implies_hook(DEREFERENCE, &set_param_dereferenced);
1591 add_hook(&match_function_call, FUNCTION_CALL_HOOK);
1592 add_hook(&match_assign, ASSIGNMENT_HOOK);
1593 add_hook(&unop_expr, OP_HOOK);
1594 add_hook(&asm_expr, ASM_HOOK);
1595
1596 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1597 add_member_info_callback(my_id, struct_member_callback);
1598 add_returned_member_callback(my_id, returned_member_callback);
1599
1600 add_hook(&assume_indexes_are_valid, OP_HOOK);
1601 }
Static analysis for C