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debug: make __smatch_about() print user data information
[smatch.git] / smatch_extra.c
blob195e73c6f4461242fb2a14c740ded265d4573a46
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 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 expression *expr, struct smatch_state *state);
64 DECLARE_PTR_LIST(void_fn_list, mod_hook *);
65 static struct void_fn_list *extra_mod_hooks;
66 static struct void_fn_list *extra_nomod_hooks;
67
68 void add_extra_mod_hook(mod_hook *fn)
69 {
70 mod_hook **p = malloc(sizeof(mod_hook *));
71 *p = fn;
72 add_ptr_list(&extra_mod_hooks, p);
73 }
74
75 void add_extra_nomod_hook(mod_hook *fn)
76 {
77 mod_hook **p = malloc(sizeof(mod_hook *));
78 *p = fn;
79 add_ptr_list(&extra_nomod_hooks, p);
80 }
81
82 void call_extra_hooks(struct void_fn_list *hooks, const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
83 {
84 mod_hook **fn;
85
86 FOR_EACH_PTR(hooks, fn) {
87 (*fn)(name, sym, expr, state);
88 } END_FOR_EACH_PTR(fn);
89 }
90
91 void call_extra_mod_hooks(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
92 {
93 call_extra_hooks(extra_mod_hooks, name, sym, expr, state);
94 }
95
96 void call_extra_nomod_hooks(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
97 {
98 call_extra_hooks(extra_nomod_hooks, name, sym, expr, state);
99 }
100
101 static void set_union_info(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
102 {
103 struct symbol *type, *tmp, *inner_type, *inner, *new_type;
104 struct expression *deref, *member_expr;
105 struct smatch_state *new;
106 int offset, inner_offset;
107 static bool in_recurse;
108 char *member_name;
109
110 if (__in_fake_assign)
111 return;
112
113 if (in_recurse)
114 return;
115 in_recurse = true;
116
117 if (!expr || expr->type != EXPR_DEREF || !expr->member)
118 goto done;
119 offset = get_member_offset_from_deref(expr);
120 if (offset < 0)
121 goto done;
122
123 deref = strip_expr(expr->deref);
124 type = get_type(deref);
125 if (type_is_ptr(type))
126 type = get_real_base_type(type);
127 if (!type || type->type != SYM_STRUCT)
128 goto done;
129
130 FOR_EACH_PTR(type->symbol_list, tmp) {
131 inner_type = get_real_base_type(tmp);
132 if (!inner_type || inner_type->type != SYM_UNION)
133 continue;
134
135 inner = first_ptr_list((struct ptr_list *)inner_type->symbol_list);
136 if (!inner || !inner->ident)
137 continue;
138
139 inner_offset = get_member_offset(type, inner->ident->name);
140 if (inner_offset < offset)
141 continue;
142 if (inner_offset > offset)
143 goto done;
144
145 FOR_EACH_PTR(inner_type->symbol_list, inner) {
146 struct symbol *tmp_type;
147
148 if (!inner->ident || inner->ident == expr->member)
149 continue;
150 tmp_type = get_real_base_type(inner);
151 if (tmp_type && tmp_type->type == SYM_STRUCT)
152 continue;
153 member_expr = deref;
154 if (tmp->ident)
155 member_expr = member_expression(member_expr, '.', tmp->ident);
156 member_expr = member_expression(member_expr, expr->op, inner->ident);
157 member_name = expr_to_var(member_expr);
158 if (!member_name)
159 continue;
160 new_type = get_real_base_type(inner);
161 new = alloc_estate_rl(cast_rl(new_type, estate_rl(state)));
162 set_extra_mod_helper(member_name, sym, member_expr, new);
163 free_string(member_name);
164 } END_FOR_EACH_PTR(inner);
165 } END_FOR_EACH_PTR(tmp);
166
167 done:
168 in_recurse = false;
169 }
170
171 static void mark_sub_members_gone(const char *name, struct symbol *sym, struct smatch_state *state)
172 {
173 struct sm_state *sm;
174
175 if (__in_fake_assign || __in_fake_var_assign)
176 return;
177
178 if (!estate_type(state) || estate_type(state)->type != SYM_PTR)
179 return;
180 if (!is_noderef_ptr_rl(estate_rl(state)))
181 return;
182
183 FOR_EACH_MY_SM(SMATCH_EXTRA, __get_cur_stree(), sm) {
184 if (sm->sym != sym)
185 continue;
186 if (strcmp(name, sm->name) == 0)
187 continue;
188 if (!is_sub_member(name, sym, sm))
189 continue;
190 set_extra_nomod(sm->name, sm->sym, NULL, alloc_estate_empty());
191 } END_FOR_EACH_SM(sm);
192 }
193
194 static void call_update_mtag_data(struct expression *expr,
195 struct smatch_state *state)
196 {
197 struct expression *faked;
198
199 if (__in_fake_var_assign)
200 return;
201
202 faked = get_faked_expression();
203 if (!faked)
204 goto update;
205 if (faked->type == EXPR_ASSIGNMENT && is_fresh_alloc(faked->right))
206 goto update;
207 return;
208
209 update:
210 update_mtag_data(expr, state);
211 }
212
213 static bool in_param_set;
214 void set_extra_mod_helper(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
215 {
216 if (!expr)
217 expr = gen_expression_from_name_sym(name, sym);
218 remove_from_equiv(name, sym);
219 set_union_info(name, sym, expr, state);
220 mark_sub_members_gone(name, sym, state);
221 call_extra_mod_hooks(name, sym, expr, state);
222 call_update_mtag_data(expr, state);
223 if ((__in_fake_assign || in_param_set) &&
224 estate_is_unknown(state) && !get_state(SMATCH_EXTRA, name, sym))
225 return;
226 set_state(SMATCH_EXTRA, name, sym, state);
227 }
228
229 static void set_extra_nomod_helper(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
230 {
231 call_extra_nomod_hooks(name, sym, expr, state);
232 set_state(SMATCH_EXTRA, name, sym, state);
233 }
234
235 static char *get_pointed_at(const char *name, struct symbol *sym, struct symbol **new_sym)
236 {
237 struct expression *assigned;
238
239 /*
240 * Imagine we have an assignment: "foo = &addr;" then the other name
241 * of "*foo" is addr.
242 */
243
244 if (name[0] != '*')
245 return NULL;
246 if (strcmp(name + 1, sym->ident->name) != 0)
247 return NULL;
248
249 assigned = get_assigned_expr_name_sym(sym->ident->name, sym);
250 if (!assigned)
251 return NULL;
252 assigned = strip_parens(assigned);
253 if (assigned->type != EXPR_PREOP || assigned->op != '&')
254 return NULL;
255
256 return expr_to_var_sym(assigned->unop, new_sym);
257 }
258
259 char *get_other_name_sym_from_chunk(const char *name, const char *chunk, int len, struct symbol *sym, struct symbol **new_sym)
260 {
261 struct expression *assigned;
262 char *orig_name = NULL;
263 char buf[256];
264 char *ret;
265
266 assigned = get_assigned_expr_name_sym(chunk, sym);
267 if (!assigned)
268 return NULL;
269 if (assigned->type == EXPR_CALL)
270 return map_call_to_other_name_sym(name, sym, new_sym);
271 if (assigned->type == EXPR_PREOP && assigned->op == '&') {
272
273 orig_name = expr_to_var_sym(assigned, new_sym);
274 if (!orig_name || !*new_sym)
275 goto free;
276
277 snprintf(buf, sizeof(buf), "%s.%s", orig_name + 1, name + len);
278 ret = alloc_string(buf);
279 free_string(orig_name);
280 return ret;
281 }
282
283 orig_name = expr_to_var_sym(assigned, new_sym);
284 if (!orig_name || !*new_sym)
285 goto free;
286
287 snprintf(buf, sizeof(buf), "%s->%s", orig_name, name + len);
288 ret = alloc_string(buf);
289 free_string(orig_name);
290 return ret;
291 free:
292 free_string(orig_name);
293 return NULL;
294 }
295
296 static char *get_long_name_sym(const char *name, struct symbol *sym, struct symbol **new_sym, bool use_stack)
297 {
298 struct expression *tmp;
299 struct sm_state *sm;
300 char buf[256];
301 int len, sym_len;
302
303 /*
304 * Just prepend the name with a different name/sym and return that.
305 * For example, if we set "foo->bar = bar;" then the other name
306 * for "bar->baz" is "foo->bar->baz". Or if we have "foo = bar;" then
307 * the other name for "bar" is "foo". A third option is if we have
308 * "foo = bar;" then another name for "*bar" is "*foo".
309 */
310
311 FOR_EACH_MY_SM(check_assigned_expr_id, __get_cur_stree(), sm) {
312 tmp = sm->state->data;
313 if (!tmp || tmp->type != EXPR_SYMBOL)
314 continue;
315 if (tmp->symbol == sym)
316 goto found;
317 } END_FOR_EACH_SM(sm);
318
319 return NULL;
320
321 found:
322 len = strlen(name);
323 sym_len = tmp->symbol->ident->len;
324 if (!use_stack && sym_len < len && name[sym_len] != '-')
325 return NULL;
326
327 if (name[0] == '*' && strcmp(name + 1, tmp->symbol_name->name) == 0)
328 snprintf(buf, sizeof(buf), "*%s", sm->name);
329 else if (sym_len < len && (name[tmp->symbol->ident->len] == '-' ||
330 name[tmp->symbol->ident->len] == '.'))
331 snprintf(buf, sizeof(buf), "%s%s", sm->name, name + tmp->symbol->ident->len);
332 else if (strcmp(name, tmp->symbol_name->name) == 0)
333 snprintf(buf, sizeof(buf), "%s", sm->name);
334 else
335 return NULL;
336
337 *new_sym = sm->sym;
338 return alloc_string(buf);
339 }
340
341 char *get_other_name_sym_helper(const char *name, struct symbol *sym, struct symbol **new_sym, bool use_stack)
342 {
343 char buf[256];
344 char *ret;
345 int len;
346
347 *new_sym = NULL;
348
349 if (!sym || !sym->ident)
350 return NULL;
351
352 ret = get_pointed_at(name, sym, new_sym);
353 if (ret)
354 return ret;
355
356 ret = map_long_to_short_name_sym(name, sym, new_sym, use_stack);
357 if (ret)
358 return ret;
359
360 len = snprintf(buf, sizeof(buf), "%s", name);
361 if (len >= sizeof(buf) - 2)
362 return NULL;
363
364 while (use_stack && len >= 1) {
365 if (buf[len] == '>' && buf[len - 1] == '-') {
366 len--;
367 buf[len] = '\0';
368 ret = get_other_name_sym_from_chunk(name, buf, len + 2, sym, new_sym);
369 if (ret)
370 return ret;
371 }
372 len--;
373 }
374
375 ret = get_long_name_sym(name, sym, new_sym, use_stack);
376 if (ret)
377 return ret;
378
379 return NULL;
380 }
381
382 char *get_other_name_sym(const char *name, struct symbol *sym, struct symbol **new_sym)
383 {
384 return get_other_name_sym_helper(name, sym, new_sym, true);
385 }
386
387 char *get_other_name_sym_nostack(const char *name, struct symbol *sym, struct symbol **new_sym)
388 {
389 return get_other_name_sym_helper(name, sym, new_sym, false);
390 }
391
392 void set_extra_mod(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
393 {
394 char *new_name;
395 struct symbol *new_sym;
396
397 set_extra_mod_helper(name, sym, expr, state);
398 new_name = get_other_name_sym_nostack(name, sym, &new_sym);
399 if (new_name && new_sym)
400 set_extra_mod_helper(new_name, new_sym, NULL, state);
401 free_string(new_name);
402 }
403
404 static struct expression *chunk_get_array_base(struct expression *expr)
405 {
406 /*
407 * The problem with is_array() is that it only returns true for things
408 * like foo[1] but not for foo[1].bar.
409 *
410 */
411 expr = strip_expr(expr);
412 while (expr && expr->type == EXPR_DEREF)
413 expr = strip_expr(expr->deref);
414 return get_array_base(expr);
415 }
416
417 static int chunk_has_array(struct expression *expr)
418 {
419 return !!chunk_get_array_base(expr);
420 }
421
422 static void clear_array_states(struct expression *array)
423 {
424 struct sm_state *sm;
425
426 sm = get_sm_state_expr(link_id, array);
427 if (sm)
428 match_link_modify(sm, NULL);
429 }
430
431 static void set_extra_array_mod(struct expression *expr, struct smatch_state *state)
432 {
433 struct expression *array;
434 struct var_sym_list *vsl;
435 struct var_sym *vs;
436 char *name;
437 struct symbol *sym;
438
439 array = chunk_get_array_base(expr);
440
441 name = expr_to_chunk_sym_vsl(expr, &sym, &vsl);
442 if (!name || !vsl) {
443 clear_array_states(array);
444 goto free;
445 }
446
447 FOR_EACH_PTR(vsl, vs) {
448 store_link(link_id, vs->var, vs->sym, name, sym);
449 } END_FOR_EACH_PTR(vs);
450
451 call_extra_mod_hooks(name, sym, expr, state);
452 set_state(SMATCH_EXTRA, name, sym, state);
453 free:
454 free_string(name);
455 }
456
457 void set_extra_expr_mod(struct expression *expr, struct smatch_state *state)
458 {
459 struct symbol *sym;
460 char *name;
461
462 if (chunk_has_array(expr)) {
463 set_extra_array_mod(expr, state);
464 return;
465 }
466
467 expr = strip_expr(expr);
468 name = expr_to_var_sym(expr, &sym);
469 if (!name || !sym)
470 goto free;
471 set_extra_mod(name, sym, expr, state);
472 free:
473 free_string(name);
474 }
475
476 void set_extra_nomod(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
477 {
478 char *new_name;
479 struct symbol *new_sym;
480 struct relation *rel;
481 struct smatch_state *orig_state;
482
483 orig_state = get_state(SMATCH_EXTRA, name, sym);
484
485 /* don't save unknown states if leaving it blank is the same */
486 if (!orig_state && estate_is_unknown(state))
487 return;
488
489 new_name = get_other_name_sym(name, sym, &new_sym);
490 if (new_name && new_sym)
491 set_extra_nomod_helper(new_name, new_sym, expr, state);
492 free_string(new_name);
493
494 if (!estate_related(orig_state)) {
495 set_extra_nomod_helper(name, sym, expr, state);
496 return;
497 }
498
499 set_related(state, estate_related(orig_state));
500 FOR_EACH_PTR(estate_related(orig_state), rel) {
501 struct smatch_state *estate;
502
503 estate = get_state(SMATCH_EXTRA, rel->name, rel->sym);
504 if (!estate)
505 continue;
506 set_extra_nomod_helper(rel->name, rel->sym, expr, clone_estate_cast(estate_type(estate), state));
507 } END_FOR_EACH_PTR(rel);
508 }
509
510 void set_extra_nomod_vsl(const char *name, struct symbol *sym, struct var_sym_list *vsl, struct expression *expr, struct smatch_state *state)
511 {
512 struct var_sym *vs;
513
514 FOR_EACH_PTR(vsl, vs) {
515 store_link(link_id, vs->var, vs->sym, name, sym);
516 } END_FOR_EACH_PTR(vs);
517
518 set_extra_nomod(name, sym, expr, state);
519 }
520
521 /*
522 * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
523 */
524 void set_extra_expr_nomod(struct expression *expr, struct smatch_state *state)
525 {
526 struct var_sym_list *vsl;
527 struct var_sym *vs;
528 char *name;
529 struct symbol *sym;
530
531 name = expr_to_chunk_sym_vsl(expr, &sym, &vsl);
532 if (!name || !vsl)
533 goto free;
534 FOR_EACH_PTR(vsl, vs) {
535 store_link(link_id, vs->var, vs->sym, name, sym);
536 } END_FOR_EACH_PTR(vs);
537
538 set_extra_nomod(name, sym, expr, state);
539 free:
540 free_string(name);
541 }
542
543 static void set_extra_true_false(const char *name, struct symbol *sym,
544 struct smatch_state *true_state,
545 struct smatch_state *false_state)
546 {
547 char *new_name;
548 struct symbol *new_sym;
549 struct relation *rel;
550 struct smatch_state *orig_state;
551
552 if (!true_state && !false_state)
553 return;
554
555 if (in_warn_on_macro())
556 return;
557
558 new_name = get_other_name_sym(name, sym, &new_sym);
559 if (new_name && new_sym)
560 set_true_false_states(SMATCH_EXTRA, new_name, new_sym, true_state, false_state);
561 free_string(new_name);
562
563 orig_state = get_state(SMATCH_EXTRA, name, sym);
564
565 if (!estate_related(orig_state)) {
566 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
567 return;
568 }
569
570 if (true_state)
571 set_related(true_state, estate_related(orig_state));
572 if (false_state)
573 set_related(false_state, estate_related(orig_state));
574
575 FOR_EACH_PTR(estate_related(orig_state), rel) {
576 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
577 true_state, false_state);
578 } END_FOR_EACH_PTR(rel);
579 }
580
581 static void set_extra_chunk_true_false(struct expression *expr,
582 struct smatch_state *true_state,
583 struct smatch_state *false_state)
584 {
585 struct var_sym_list *vsl;
586 struct var_sym *vs;
587 struct symbol *type;
588 char *name;
589 struct symbol *sym;
590
591 if (in_warn_on_macro())
592 return;
593
594 type = get_type(expr);
595 if (!type)
596 return;
597
598 name = expr_to_chunk_sym_vsl(expr, &sym, &vsl);
599 if (!name || !vsl)
600 goto free;
601 FOR_EACH_PTR(vsl, vs) {
602 store_link(link_id, vs->var, vs->sym, name, sym);
603 } END_FOR_EACH_PTR(vs);
604
605 set_true_false_states(SMATCH_EXTRA, name, sym,
606 clone_estate(true_state),
607 clone_estate(false_state));
608 free:
609 free_string(name);
610 }
611
612 static void set_extra_expr_true_false(struct expression *expr,
613 struct smatch_state *true_state,
614 struct smatch_state *false_state)
615 {
616 char *name;
617 struct symbol *sym;
618 sval_t sval;
619
620 if (!true_state && !false_state)
621 return;
622
623 if (get_value(expr, &sval))
624 return;
625
626 expr = strip_expr(expr);
627 name = expr_to_var_sym(expr, &sym);
628 if (!name || !sym) {
629 free_string(name);
630 set_extra_chunk_true_false(expr, true_state, false_state);
631 return;
632 }
633 set_extra_true_false(name, sym, true_state, false_state);
634 free_string(name);
635 }
636
637 static int get_countdown_info(struct expression *condition, struct expression **unop, int *op, sval_t *right)
638 {
639 struct expression *unop_expr;
640 int comparison;
641 sval_t limit;
642
643 right->type = &int_ctype;
644 right->value = 0;
645
646 condition = strip_expr(condition);
647
648 if (condition->type == EXPR_COMPARE) {
649 comparison = remove_unsigned_from_comparison(condition->op);
650
651 if (comparison != SPECIAL_GTE && comparison != '>')
652 return 0;
653 if (!get_value(condition->right, &limit))
654 return 0;
655
656 unop_expr = condition->left;
657 if (unop_expr->type != EXPR_PREOP && unop_expr->type != EXPR_POSTOP)
658 return 0;
659 if (unop_expr->op != SPECIAL_DECREMENT)
660 return 0;
661
662 *unop = unop_expr;
663 *op = comparison;
664 *right = limit;
665
666 return 1;
667 }
668
669 if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
670 return 0;
671 if (condition->op != SPECIAL_DECREMENT)
672 return 0;
673
674 *unop = condition;
675 *op = '>';
676
677 return 1;
678 }
679
680 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
681 {
682 struct expression *iter_var;
683 struct expression *condition, *unop;
684 struct symbol *type;
685 struct sm_state *sm;
686 struct smatch_state *estate;
687 int op;
688 sval_t start, right;
689
690 right.type = &int_ctype;
691 right.value = 0;
692
693 condition = strip_expr(loop->iterator_pre_condition);
694 if (!condition)
695 return NULL;
696
697 if (!get_countdown_info(condition, &unop, &op, &right))
698 return NULL;
699
700 iter_var = unop->unop;
701
702 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
703 if (!sm)
704 return NULL;
705 if (sval_cmp(estate_min(sm->state), right) < 0)
706 return NULL;
707 start = estate_max(sm->state);
708
709 type = get_type(iter_var);
710 right = sval_cast(type, right);
711 start = sval_cast(type, start);
712
713 if (sval_cmp(start, right) <= 0)
714 return NULL;
715 if (!sval_is_max(start))
716 start.value--;
717
718 if (op == SPECIAL_GTE)
719 right.value--;
720
721 if (unop->type == EXPR_PREOP) {
722 right.value++;
723 estate = alloc_estate_range(right, start);
724 if (estate_has_hard_max(sm->state))
725 estate_set_hard_max(estate);
726 estate_copy_fuzzy_max(estate, sm->state);
727 set_extra_expr_mod(iter_var, estate);
728 }
729 if (unop->type == EXPR_POSTOP) {
730 estate = alloc_estate_range(right, start);
731 if (estate_has_hard_max(sm->state))
732 estate_set_hard_max(estate);
733 estate_copy_fuzzy_max(estate, sm->state);
734 set_extra_expr_mod(iter_var, estate);
735 }
736 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
737 }
738
739 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
740 struct expression *condition)
741 {
742 struct expression *iter_var;
743 struct sm_state *sm;
744 struct smatch_state *estate;
745 sval_t start, end, max;
746 bool unknown_end = false;
747
748 iter_var = iter_expr->unop;
749 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
750 if (!sm)
751 return NULL;
752 if (!estate_get_single_value(sm->state, &start))
753 return NULL;
754 if (!get_implied_max(condition->right, &end)) {
755 end = sval_type_max(get_type(condition->right));
756 end = sval_cast(start.type, end);
757 if (sval_is_max(end))
758 unknown_end = true;
759 }
760
761 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
762 return NULL;
763
764 switch (condition->op) {
765 case SPECIAL_UNSIGNED_LT:
766 case SPECIAL_NOTEQUAL:
767 case '<':
768 if (!sval_is_min(end) && !unknown_end)
769 end.value--;
770 break;
771 case SPECIAL_UNSIGNED_LTE:
772 case SPECIAL_LTE:
773 break;
774 default:
775 return NULL;
776 }
777 if (sval_cmp(end, start) < 0)
778 return NULL;
779 end = sval_cast(start.type, end);
780 estate = alloc_estate_range(start, end);
781 if (get_hard_max(condition->right, &max)) {
782 if (!get_macro_name(condition->pos))
783 estate_set_hard_max(estate);
784 if (condition->op == '<' ||
785 condition->op == SPECIAL_UNSIGNED_LT ||
786 condition->op == SPECIAL_NOTEQUAL)
787 max.value--;
788 max = sval_cast(start.type, max);
789 estate_set_fuzzy_max(estate, max);
790 }
791 set_extra_expr_mod(iter_var, estate);
792 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
793 }
794
795 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
796 struct expression *condition)
797 {
798 struct expression *iter_var;
799 struct sm_state *sm;
800 struct smatch_state *estate;
801 sval_t start, end;
802
803 iter_var = iter_expr->unop;
804 sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
805 if (!sm)
806 return NULL;
807 if (!estate_get_single_value(sm->state, &start))
808 return NULL;
809 if (!get_implied_min(condition->right, &end))
810 end = sval_type_min(get_type(iter_var));
811 end = sval_cast(estate_type(sm->state), end);
812 if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
813 return NULL;
814
815 switch (condition->op) {
816 case SPECIAL_NOTEQUAL:
817 case '>':
818 if (!sval_is_max(end))
819 end.value++;
820 break;
821 case SPECIAL_GTE:
822 break;
823 default:
824 return NULL;
825 }
826 if (sval_cmp(end, start) > 0)
827 return NULL;
828 estate = alloc_estate_range(end, start);
829 estate_set_hard_max(estate);
830 estate_set_fuzzy_max(estate, estate_get_fuzzy_max(estate));
831 set_extra_expr_mod(iter_var, estate);
832 return get_sm_state_expr(SMATCH_EXTRA, iter_var);
833 }
834
835 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
836 {
837 struct expression *iter_expr;
838 struct expression *condition;
839
840 if (!loop->iterator_post_statement)
841 return NULL;
842 if (loop->iterator_post_statement->type != STMT_EXPRESSION)
843 return NULL;
844 iter_expr = loop->iterator_post_statement->expression;
845 if (!loop->iterator_pre_condition)
846 return NULL;
847 if (loop->iterator_pre_condition->type != EXPR_COMPARE)
848 return NULL;
849 condition = loop->iterator_pre_condition;
850
851 if (iter_expr->op == SPECIAL_INCREMENT)
852 return handle_canonical_for_inc(iter_expr, condition);
853 if (iter_expr->op == SPECIAL_DECREMENT)
854 return handle_canonical_for_dec(iter_expr, condition);
855 return NULL;
856 }
857
858 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct stree **stree)
859 {
860 struct sm_state *ret;
861
862 /*
863 * Canonical loops are a hack. The proper way to handle this is to
864 * use two passes, but unfortunately, doing two passes makes parsing
865 * code twice as slow.
866 *
867 * What we do is we set the inside state here, which overwrites whatever
868 * __extra_match_condition() does. Then we set the outside state in
869 * __extra_pre_loop_hook_after().
870 *
871 */
872 __push_fake_cur_stree();
873 if (!loop->iterator_post_statement)
874 ret = handle_canonical_while_count_down(loop);
875 else
876 ret = handle_canonical_for_loops(loop);
877 *stree = __pop_fake_cur_stree();
878 return ret;
879 }
880
881 int __iterator_unchanged(struct sm_state *sm)
882 {
883 if (!sm)
884 return 0;
885 if (get_sm_state(my_id, sm->name, sm->sym) == sm)
886 return 1;
887 return 0;
888 }
889
890 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
891 {
892 struct expression *unop;
893 int op;
894 sval_t limit, after_value;
895
896 if (!get_countdown_info(condition, &unop, &op, &limit))
897 return;
898 after_value = estate_min(sm->state);
899 after_value.value--;
900 set_extra_mod(sm->name, sm->sym, condition->unop, alloc_estate_sval(after_value));
901 }
902
903 void __extra_pre_loop_hook_after(struct sm_state *sm,
904 struct statement *iterator,
905 struct expression *condition)
906 {
907 struct expression *iter_expr;
908 sval_t limit;
909 struct smatch_state *state;
910 sval_t end;
911
912 if (!iterator) {
913 while_count_down_after(sm, condition);
914 return;
915 }
916
917 iter_expr = iterator->expression;
918
919 if (condition->type != EXPR_COMPARE)
920 return;
921
922 if (iter_expr->op == SPECIAL_INCREMENT) {
923 if (!get_implied_value(condition->right, &end) &&
924 sval_is_max(estate_max(sm->state)))
925 limit = estate_max(sm->state);
926 else
927 limit = sval_binop(estate_max(sm->state), '+',
928 sval_type_val(estate_type(sm->state), 1));
929 } else {
930 limit = sval_binop(estate_min(sm->state), '-',
931 sval_type_val(estate_type(sm->state), 1));
932 }
933 limit = sval_cast(estate_type(sm->state), limit);
934 if (!estate_has_hard_max(sm->state) && !__has_breaks()) {
935 if (iter_expr->op == SPECIAL_INCREMENT)
936 state = alloc_estate_range(estate_min(sm->state), limit);
937 else
938 state = alloc_estate_range(limit, estate_max(sm->state));
939 } else {
940 state = alloc_estate_sval(limit);
941 }
942 if (!estate_has_hard_max(sm->state)) {
943 estate_clear_hard_max(state);
944 }
945 if (estate_has_fuzzy_max(sm->state)) {
946 sval_t hmax = estate_get_fuzzy_max(sm->state);
947 sval_t max = estate_max(sm->state);
948
949 if (sval_cmp(hmax, max) != 0)
950 estate_clear_fuzzy_max(state);
951 } else if (!estate_has_fuzzy_max(sm->state)) {
952 estate_clear_fuzzy_max(state);
953 }
954
955 set_extra_mod(sm->name, sm->sym, iter_expr, state);
956 }
957
958 static bool get_global_rl(const char *name, struct symbol *sym, struct range_list **rl)
959 {
960 struct expression *expr;
961
962 if (!sym || !(sym->ctype.modifiers & MOD_TOPLEVEL) || !sym->ident)
963 return false;
964 if (strcmp(sym->ident->name, name) != 0)
965 return false;
966
967 expr = symbol_expression(sym);
968 return get_implied_rl(expr, rl);
969 }
970
971 static struct stree *unmatched_stree;
972 static struct smatch_state *unmatched_state(struct sm_state *sm)
973 {
974 struct smatch_state *state;
975 struct range_list *rl;
976
977 if (unmatched_stree) {
978 state = get_state_stree(unmatched_stree, SMATCH_EXTRA, sm->name, sm->sym);
979 if (state)
980 return state;
981 }
982 if (parent_is_gone_var_sym(sm->name, sm->sym))
983 return alloc_estate_empty();
984 if (get_global_rl(sm->name, sm->sym, &rl))
985 return alloc_estate_rl(rl);
986 return alloc_estate_whole(estate_type(sm->state));
987 }
988
989 static void clear_the_pointed_at(struct expression *expr)
990 {
991 struct stree *stree;
992 char *name;
993 struct symbol *sym;
994 struct sm_state *tmp;
995
996 name = expr_to_var_sym(expr, &sym);
997 if (!name || !sym)
998 goto free;
999
1000 stree = __get_cur_stree();
1001 FOR_EACH_MY_SM(SMATCH_EXTRA, stree, tmp) {
1002 if (tmp->name[0] != '*')
1003 continue;
1004 if (tmp->sym != sym)
1005 continue;
1006 if (strcmp(tmp->name + 1, name) != 0)
1007 continue;
1008 set_extra_mod(tmp->name, tmp->sym, expr, alloc_estate_whole(estate_type(tmp->state)));
1009 } END_FOR_EACH_SM(tmp);
1010
1011 free:
1012 free_string(name);
1013 }
1014
1015 static int is_const_param(struct expression *expr, int param)
1016 {
1017 struct symbol *type;
1018
1019 type = get_arg_type(expr, param);
1020 if (!type)
1021 return 0;
1022 if (type->ctype.modifiers & MOD_CONST)
1023 return 1;
1024 return 0;
1025 }
1026
1027 static void match_function_call(struct expression *expr)
1028 {
1029 struct expression *arg;
1030 struct expression *tmp;
1031 int param = -1;
1032
1033 /* if we have the db this is handled in smatch_function_hooks.c */
1034 if (!option_no_db)
1035 return;
1036 if (inlinable(expr->fn))
1037 return;
1038
1039 FOR_EACH_PTR(expr->args, arg) {
1040 param++;
1041 if (is_const_param(expr->fn, param))
1042 continue;
1043 tmp = strip_expr(arg);
1044 if (tmp->type == EXPR_PREOP && tmp->op == '&')
1045 set_extra_expr_mod(tmp->unop, alloc_estate_whole(get_type(tmp->unop)));
1046 else
1047 clear_the_pointed_at(tmp);
1048 } END_FOR_EACH_PTR(arg);
1049 }
1050
1051 int values_fit_type(struct expression *left, struct expression *right)
1052 {
1053 struct range_list *rl;
1054 struct symbol *type;
1055
1056 type = get_type(left);
1057 if (!type)
1058 return 0;
1059 get_absolute_rl(right, &rl);
1060 if (type == rl_type(rl))
1061 return 1;
1062 if (type_unsigned(type) && sval_is_negative(rl_min(rl)))
1063 return 0;
1064 if (sval_cmp(sval_type_min(type), rl_min(rl)) > 0)
1065 return 0;
1066 if (sval_cmp(sval_type_max(type), rl_max(rl)) < 0)
1067 return 0;
1068 return 1;
1069 }
1070
1071 static void save_chunk_info(struct expression *left, struct expression *right)
1072 {
1073 struct var_sym_list *vsl;
1074 struct var_sym *vs;
1075 struct expression *add_expr;
1076 struct symbol *type;
1077 sval_t sval;
1078 char *name;
1079 struct symbol *sym;
1080
1081 if (right->type != EXPR_BINOP || right->op != '-')
1082 return;
1083 if (!get_value(right->left, &sval))
1084 return;
1085 if (!expr_to_sym(right->right))
1086 return;
1087
1088 add_expr = binop_expression(left, '+', right->right);
1089 type = get_type(add_expr);
1090 if (!type)
1091 return;
1092 name = expr_to_chunk_sym_vsl(add_expr, &sym, &vsl);
1093 if (!name || !vsl)
1094 goto free;
1095 FOR_EACH_PTR(vsl, vs) {
1096 store_link(link_id, vs->var, vs->sym, name, sym);
1097 } END_FOR_EACH_PTR(vs);
1098
1099 set_state(SMATCH_EXTRA, name, sym, alloc_estate_sval(sval_cast(type, sval)));
1100 free:
1101 free_string(name);
1102 }
1103
1104 static void do_array_assign(struct expression *left, int op, struct expression *right)
1105 {
1106 struct range_list *rl;
1107
1108 if (op == '=') {
1109 get_absolute_rl(right, &rl);
1110 rl = cast_rl(get_type(left), rl);
1111 } else {
1112 rl = alloc_whole_rl(get_type(left));
1113 }
1114
1115 set_extra_array_mod(left, alloc_estate_rl(rl));
1116 }
1117
1118 static void match_vanilla_assign(struct expression *left, struct expression *right)
1119 {
1120 struct range_list *orig_rl = NULL;
1121 struct range_list *rl = NULL;
1122 struct symbol *right_sym;
1123 struct symbol *left_type;
1124 struct symbol *right_type;
1125 char *right_name = NULL;
1126 struct symbol *sym;
1127 char *name;
1128 sval_t sval, max;
1129 struct smatch_state *state;
1130 int comparison;
1131
1132 if (is_struct(left))
1133 return;
1134
1135 save_chunk_info(left, right);
1136
1137 name = expr_to_var_sym(left, &sym);
1138 if (!name) {
1139 if (chunk_has_array(left))
1140 do_array_assign(left, '=', right);
1141 return;
1142 }
1143
1144 left_type = get_type(left);
1145 right_type = get_type(right);
1146
1147 right_name = expr_to_var_sym(right, &right_sym);
1148
1149 if (!__in_fake_assign &&
1150 !(right->type == EXPR_PREOP && right->op == '&') &&
1151 right_name && right_sym &&
1152 values_fit_type(left, strip_expr(right)) &&
1153 !has_symbol(right, sym)) {
1154 set_equiv(left, right);
1155 goto free;
1156 }
1157
1158 if (get_implied_value(right, &sval)) {
1159 state = alloc_estate_sval(sval_cast(left_type, sval));
1160 goto done;
1161 }
1162
1163 if (__in_fake_assign || is_fake_var(left)) {
1164 struct smatch_state *right_state;
1165 struct range_list *rl;
1166
1167 right_state = get_state(SMATCH_EXTRA, right_name, right_sym);
1168 if (right_state) {
1169 /* simple assignment */
1170 state = clone_estate(right_state);
1171 goto done;
1172 }
1173
1174 if (get_implied_rl(right, &rl)) {
1175 rl = cast_rl(left_type, rl);
1176 state = alloc_estate_rl(rl);
1177 goto done;
1178 }
1179
1180 state = alloc_estate_rl(alloc_whole_rl(left_type));
1181 goto done;
1182 }
1183
1184 comparison = get_comparison_no_extra(left, right);
1185 if (comparison) {
1186 comparison = flip_comparison(comparison);
1187 get_implied_rl(left, &orig_rl);
1188 }
1189
1190 if (get_implied_rl(right, &rl)) {
1191 rl = cast_rl(left_type, rl);
1192 if (orig_rl)
1193 filter_by_comparison(&rl, comparison, orig_rl);
1194 state = alloc_estate_rl(rl);
1195 if (get_hard_max(right, &max)) {
1196 estate_set_hard_max(state);
1197 estate_set_fuzzy_max(state, max);
1198 }
1199 } else {
1200 rl = alloc_whole_rl(right_type);
1201 rl = cast_rl(left_type, rl);
1202 if (orig_rl)
1203 filter_by_comparison(&rl, comparison, orig_rl);
1204 state = alloc_estate_rl(rl);
1205 }
1206
1207 done:
1208 set_extra_mod(name, sym, left, state);
1209 free:
1210 free_string(right_name);
1211 }
1212
1213 static void match_assign(struct expression *expr)
1214 {
1215 struct range_list *rl = NULL;
1216 struct expression *left;
1217 struct expression *right;
1218 struct expression *binop_expr;
1219 struct symbol *left_type;
1220 struct symbol *sym;
1221 char *name;
1222
1223 left = strip_expr(expr->left);
1224
1225 right = strip_parens(expr->right);
1226 if (right->type == EXPR_CALL && sym_name_is("__builtin_expect", right->fn))
1227 right = get_argument_from_call_expr(right->args, 0);
1228 while (right->type == EXPR_ASSIGNMENT && right->op == '=')
1229 right = strip_parens(right->left);
1230
1231 if (expr->op == '=' && is_condition(expr->right))
1232 return; /* handled in smatch_condition.c */
1233 if (expr->op == '=' && right->type == EXPR_CALL &&
1234 !is_fake_call(right))
1235 return; /* handled in smatch_function_hooks.c */
1236 if (expr->op == '=') {
1237 match_vanilla_assign(left, right);
1238 return;
1239 }
1240
1241 name = expr_to_var_sym(left, &sym);
1242 if (!name)
1243 return;
1244
1245 left_type = get_type(left);
1246
1247 switch (expr->op) {
1248 case SPECIAL_ADD_ASSIGN:
1249 case SPECIAL_SUB_ASSIGN:
1250 case SPECIAL_AND_ASSIGN:
1251 case SPECIAL_MOD_ASSIGN:
1252 case SPECIAL_SHL_ASSIGN:
1253 case SPECIAL_SHR_ASSIGN:
1254 case SPECIAL_OR_ASSIGN:
1255 case SPECIAL_XOR_ASSIGN:
1256 case SPECIAL_MUL_ASSIGN:
1257 case SPECIAL_DIV_ASSIGN:
1258 binop_expr = binop_expression(expr->left,
1259 op_remove_assign(expr->op),
1260 expr->right);
1261 get_absolute_rl(binop_expr, &rl);
1262 rl = cast_rl(left_type, rl);
1263 if (inside_loop()) {
1264 if (expr->op == SPECIAL_ADD_ASSIGN)
1265 add_range(&rl, rl_max(rl), sval_type_max(rl_type(rl)));
1266
1267 if (expr->op == SPECIAL_SUB_ASSIGN &&
1268 !sval_is_negative(rl_min(rl))) {
1269 sval_t zero = { .type = rl_type(rl) };
1270
1271 add_range(&rl, rl_min(rl), zero);
1272 }
1273 }
1274 set_extra_mod(name, sym, left, alloc_estate_rl(rl));
1275 goto free;
1276 }
1277 set_extra_mod(name, sym, left, alloc_estate_whole(left_type));
1278 free:
1279 free_string(name);
1280 }
1281
1282 static struct smatch_state *increment_state(struct smatch_state *state)
1283 {
1284 sval_t min = estate_min(state);
1285 sval_t max = estate_max(state);
1286
1287 if (!estate_rl(state))
1288 return NULL;
1289
1290 if (inside_loop())
1291 max = sval_type_max(max.type);
1292
1293 if (!sval_is_min(min) && !sval_is_max(min))
1294 min.value++;
1295 if (!sval_is_min(max) && !sval_is_max(max))
1296 max.value++;
1297 return alloc_estate_range(min, max);
1298 }
1299
1300 static struct smatch_state *decrement_state(struct smatch_state *state)
1301 {
1302 sval_t min = estate_min(state);
1303 sval_t max = estate_max(state);
1304
1305 if (!estate_rl(state))
1306 return NULL;
1307
1308 if (inside_loop())
1309 min = sval_type_min(min.type);
1310
1311 if (!sval_is_min(min) && !sval_is_max(min))
1312 min.value--;
1313 if (!sval_is_min(max) && !sval_is_max(max))
1314 max.value--;
1315 return alloc_estate_range(min, max);
1316 }
1317
1318 static void clear_pointed_at_state(struct expression *expr)
1319 {
1320 struct symbol *type;
1321
1322 /*
1323 * ALERT: This is sort of a mess. If it's is a struct assigment like
1324 * "foo = bar;", then that's handled by smatch_struct_assignment.c.
1325 * the same thing for p++ where "p" is a struct. Most modifications
1326 * are handled by the assignment hook or the db. Smatch_extra.c doesn't
1327 * use smatch_modification.c because we have to get the ordering right
1328 * or something. So if you have p++ where p is a pointer to a standard
1329 * c type then we handle that here. What a mess.
1330 */
1331 expr = strip_expr(expr);
1332 type = get_type(expr);
1333 if (!type || type->type != SYM_PTR)
1334 return;
1335 type = get_real_base_type(type);
1336 if (!type || type->type != SYM_BASETYPE)
1337 return;
1338 set_extra_expr_nomod(deref_expression(expr), alloc_estate_whole(type));
1339 }
1340
1341 static void unop_expr(struct expression *expr)
1342 {
1343 struct smatch_state *state;
1344
1345 if (expr->smatch_flags & Handled)
1346 return;
1347
1348 switch (expr->op) {
1349 case SPECIAL_INCREMENT:
1350 state = get_state_expr(SMATCH_EXTRA, expr->unop);
1351 state = increment_state(state);
1352 if (!state)
1353 state = alloc_estate_whole(get_type(expr));
1354 set_extra_expr_mod(expr->unop, state);
1355 clear_pointed_at_state(expr->unop);
1356 break;
1357 case SPECIAL_DECREMENT:
1358 state = get_state_expr(SMATCH_EXTRA, expr->unop);
1359 state = decrement_state(state);
1360 if (!state)
1361 state = alloc_estate_whole(get_type(expr));
1362 set_extra_expr_mod(expr->unop, state);
1363 clear_pointed_at_state(expr->unop);
1364 break;
1365 default:
1366 return;
1367 }
1368 }
1369
1370 static void asm_expr(struct statement *stmt)
1371 {
1372 struct asm_operand *op;
1373 struct symbol *type;
1374
1375 FOR_EACH_PTR(stmt->asm_outputs, op) {
1376 type = get_type(strip_expr(op->expr));
1377 set_extra_expr_mod(op->expr, alloc_estate_whole(type));
1378 } END_FOR_EACH_PTR(op);
1379 }
1380
1381 static void check_dereference(struct expression *expr)
1382 {
1383 struct smatch_state *state;
1384
1385 if (__in_fake_assign)
1386 return;
1387 if (outside_of_function())
1388 return;
1389 state = get_extra_state(expr);
1390 if (state) {
1391 struct range_list *rl;
1392
1393 rl = rl_intersection(estate_rl(state), valid_ptr_rl);
1394 if (rl_equiv(rl, estate_rl(state)))
1395 return;
1396 set_extra_expr_nomod(expr, alloc_estate_rl(rl));
1397 } else {
1398 struct range_list *rl;
1399
1400 if (get_mtag_rl(expr, &rl))
1401 rl = rl_intersection(rl, valid_ptr_rl);
1402 else
1403 rl = clone_rl(valid_ptr_rl);
1404
1405 set_extra_expr_nomod(expr, alloc_estate_rl(rl));
1406 }
1407 }
1408
1409 static void match_dereferences(struct expression *expr)
1410 {
1411 if (expr->type != EXPR_PREOP)
1412 return;
1413 if (getting_address(expr))
1414 return;
1415 /* it's saying that foo[1] = bar dereferences foo[1] */
1416 if (is_array(expr))
1417 return;
1418 check_dereference(expr->unop);
1419 }
1420
1421 static void match_pointer_as_array(struct expression *expr)
1422 {
1423 if (!is_array(expr))
1424 return;
1425 check_dereference(get_array_base(expr));
1426 }
1427
1428 static void find_dereferences(struct expression *expr)
1429 {
1430 while (expr->type == EXPR_PREOP) {
1431 if (expr->op == '*')
1432 check_dereference(expr->unop);
1433 expr = strip_expr(expr->unop);
1434 }
1435 }
1436
1437 static void set_param_dereferenced(struct expression *call, struct expression *arg, char *key, char *unused)
1438 {
1439 struct symbol *sym;
1440 char *name;
1441
1442 name = get_variable_from_key(arg, key, &sym);
1443 if (name && sym) {
1444 struct smatch_state *orig, *new;
1445 struct range_list *rl;
1446
1447 orig = get_state(SMATCH_EXTRA, name, sym);
1448 if (orig) {
1449 rl = rl_intersection(estate_rl(orig),
1450 alloc_rl(valid_ptr_min_sval,
1451 valid_ptr_max_sval));
1452 new = alloc_estate_rl(rl);
1453 } else {
1454 new = alloc_estate_range(valid_ptr_min_sval, valid_ptr_max_sval);
1455 }
1456
1457 set_extra_nomod(name, sym, NULL, new);
1458 }
1459 free_string(name);
1460
1461 find_dereferences(arg);
1462 }
1463
1464 static sval_t add_one(sval_t sval)
1465 {
1466 sval.value++;
1467 return sval;
1468 }
1469
1470 static int handle_postop_inc(struct expression *left, int op, struct expression *right)
1471 {
1472 struct statement *stmt;
1473 struct expression *cond;
1474 struct smatch_state *true_state, *false_state;
1475 struct symbol *type;
1476 sval_t start;
1477 sval_t limit;
1478
1479 /*
1480 * If we're decrementing here then that's a canonical while count down
1481 * so it's handled already. We're only handling loops like:
1482 * i = 0;
1483 * do { ... } while (i++ < 3);
1484 */
1485
1486 if (left->type != EXPR_POSTOP || left->op != SPECIAL_INCREMENT)
1487 return 0;
1488
1489 stmt = __cur_stmt->parent;
1490 if (!stmt)
1491 return 0;
1492 if (stmt->type == STMT_COMPOUND)
1493 stmt = stmt->parent;
1494 if (!stmt || stmt->type != STMT_ITERATOR || !stmt->iterator_post_condition)
1495 return 0;
1496
1497 cond = strip_expr(stmt->iterator_post_condition);
1498 if (cond->type != EXPR_COMPARE || cond->op != op)
1499 return 0;
1500 if (left != strip_expr(cond->left) || right != strip_expr(cond->right))
1501 return 0;
1502
1503 if (!get_implied_value(left->unop, &start))
1504 return 0;
1505 if (!get_implied_value(right, &limit))
1506 return 0;
1507 type = get_type(left->unop);
1508 limit = sval_cast(type, limit);
1509 if (sval_cmp(start, limit) > 0)
1510 return 0;
1511
1512 switch (op) {
1513 case '<':
1514 case SPECIAL_UNSIGNED_LT:
1515 break;
1516 case SPECIAL_LTE:
1517 case SPECIAL_UNSIGNED_LTE:
1518 limit = add_one(limit);
1519 default:
1520 return 0;
1521
1522 }
1523
1524 true_state = alloc_estate_range(add_one(start), limit);
1525 false_state = alloc_estate_range(add_one(limit), add_one(limit));
1526
1527 /* Currently we just discard the false state but when two passes is
1528 * implimented correctly then it will use it.
1529 */
1530
1531 set_extra_expr_true_false(left->unop, true_state, false_state);
1532
1533 return 1;
1534 }
1535
1536 bool is_impossible_variable(struct expression *expr)
1537 {
1538 struct smatch_state *state;
1539
1540 state = get_extra_state(expr);
1541 if (state && !estate_rl(state))
1542 return true;
1543 return false;
1544 }
1545
1546 static bool in_macro(struct expression *left, struct expression *right)
1547 {
1548 if (!left || !right)
1549 return 0;
1550 if (left->pos.line != right->pos.line || left->pos.pos != right->pos.pos)
1551 return 0;
1552 if (get_macro_name(left->pos))
1553 return 1;
1554 return 0;
1555 }
1556
1557 static void handle_comparison(struct symbol *type, struct expression *left, int op, struct expression *right)
1558 {
1559 struct range_list *left_orig;
1560 struct range_list *left_true;
1561 struct range_list *left_false;
1562 struct range_list *right_orig;
1563 struct range_list *right_true;
1564 struct range_list *right_false;
1565 struct smatch_state *left_true_state;
1566 struct smatch_state *left_false_state;
1567 struct smatch_state *right_true_state;
1568 struct smatch_state *right_false_state;
1569 sval_t dummy, hard_max;
1570 int left_postop = 0;
1571 int right_postop = 0;
1572
1573 if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
1574 if (left->type == EXPR_POSTOP) {
1575 left->smatch_flags |= Handled;
1576 left_postop = left->op;
1577 if (handle_postop_inc(left, op, right))
1578 return;
1579 }
1580 left = strip_parens(left->unop);
1581 }
1582 while (left->type == EXPR_ASSIGNMENT)
1583 left = strip_parens(left->left);
1584
1585 if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
1586 if (right->type == EXPR_POSTOP) {
1587 right->smatch_flags |= Handled;
1588 right_postop = right->op;
1589 }
1590 right = strip_parens(right->unop);
1591 }
1592
1593 if (is_impossible_variable(left) || is_impossible_variable(right))
1594 return;
1595
1596 get_real_absolute_rl(left, &left_orig);
1597 left_orig = cast_rl(type, left_orig);
1598
1599 get_real_absolute_rl(right, &right_orig);
1600 right_orig = cast_rl(type, right_orig);
1601
1602 split_comparison_rl(left_orig, op, right_orig, &left_true, &left_false, &right_true, &right_false);
1603
1604 left_true = rl_truncate_cast(get_type(strip_expr(left)), left_true);
1605 left_false = rl_truncate_cast(get_type(strip_expr(left)), left_false);
1606 right_true = rl_truncate_cast(get_type(strip_expr(right)), right_true);
1607 right_false = rl_truncate_cast(get_type(strip_expr(right)), right_false);
1608
1609 if (!left_true || !left_false) {
1610 struct range_list *tmp_true, *tmp_false;
1611
1612 split_comparison_rl(alloc_whole_rl(type), op, right_orig, &tmp_true, &tmp_false, NULL, NULL);
1613 tmp_true = rl_truncate_cast(get_type(strip_expr(left)), tmp_true);
1614 tmp_false = rl_truncate_cast(get_type(strip_expr(left)), tmp_false);
1615 if (tmp_true && tmp_false)
1616 __save_imaginary_state(left, tmp_true, tmp_false);
1617 }
1618
1619 if (!right_true || !right_false) {
1620 struct range_list *tmp_true, *tmp_false;
1621
1622 split_comparison_rl(alloc_whole_rl(type), op, right_orig, NULL, NULL, &tmp_true, &tmp_false);
1623 tmp_true = rl_truncate_cast(get_type(strip_expr(right)), tmp_true);
1624 tmp_false = rl_truncate_cast(get_type(strip_expr(right)), tmp_false);
1625 if (tmp_true && tmp_false)
1626 __save_imaginary_state(right, tmp_true, tmp_false);
1627 }
1628
1629 left_true_state = alloc_estate_rl(left_true);
1630 left_false_state = alloc_estate_rl(left_false);
1631 right_true_state = alloc_estate_rl(right_true);
1632 right_false_state = alloc_estate_rl(right_false);
1633
1634 switch (op) {
1635 case '<':
1636 case SPECIAL_UNSIGNED_LT:
1637 case SPECIAL_UNSIGNED_LTE:
1638 case SPECIAL_LTE:
1639 if (get_hard_max(right, &dummy) && !in_macro(left, right))
1640 estate_set_hard_max(left_true_state);
1641 if (get_hard_max(left, &dummy) && !in_macro(left, right))
1642 estate_set_hard_max(right_false_state);
1643 break;
1644 case '>':
1645 case SPECIAL_UNSIGNED_GT:
1646 case SPECIAL_UNSIGNED_GTE:
1647 case SPECIAL_GTE:
1648 if (get_hard_max(left, &dummy) && !in_macro(left, right))
1649 estate_set_hard_max(right_true_state);
1650 if (get_hard_max(right, &dummy) && !in_macro(left, right))
1651 estate_set_hard_max(left_false_state);
1652 break;
1653 }
1654
1655 switch (op) {
1656 case '<':
1657 case SPECIAL_UNSIGNED_LT:
1658 case SPECIAL_UNSIGNED_LTE:
1659 case SPECIAL_LTE:
1660 if (get_hard_max(right, &hard_max)) {
1661 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1662 hard_max.value--;
1663 estate_set_fuzzy_max(left_true_state, hard_max);
1664 }
1665 if (get_implied_value(right, &hard_max)) {
1666 if (op == SPECIAL_UNSIGNED_LTE ||
1667 op == SPECIAL_LTE)
1668 hard_max.value++;
1669 estate_set_fuzzy_max(left_false_state, hard_max);
1670 }
1671 if (get_hard_max(left, &hard_max)) {
1672 if (op == SPECIAL_UNSIGNED_LTE ||
1673 op == SPECIAL_LTE)
1674 hard_max.value--;
1675 estate_set_fuzzy_max(right_false_state, hard_max);
1676 }
1677 if (get_implied_value(left, &hard_max)) {
1678 if (op == '<' || op == SPECIAL_UNSIGNED_LT)
1679 hard_max.value++;
1680 estate_set_fuzzy_max(right_true_state, hard_max);
1681 }
1682 break;
1683 case '>':
1684 case SPECIAL_UNSIGNED_GT:
1685 case SPECIAL_UNSIGNED_GTE:
1686 case SPECIAL_GTE:
1687 if (get_hard_max(left, &hard_max)) {
1688 if (op == '>' || op == SPECIAL_UNSIGNED_GT)
1689 hard_max.value--;
1690 estate_set_fuzzy_max(right_true_state, hard_max);
1691 }
1692 if (get_implied_value(left, &hard_max)) {
1693 if (op == SPECIAL_UNSIGNED_GTE ||
1694 op == SPECIAL_GTE)
1695 hard_max.value++;
1696 estate_set_fuzzy_max(right_false_state, hard_max);
1697 }
1698 if (get_hard_max(right, &hard_max)) {
1699 if (op == SPECIAL_UNSIGNED_LTE ||
1700 op == SPECIAL_LTE)
1701 hard_max.value--;
1702 estate_set_fuzzy_max(left_false_state, hard_max);
1703 }
1704 if (get_implied_value(right, &hard_max)) {
1705 if (op == '>' ||
1706 op == SPECIAL_UNSIGNED_GT)
1707 hard_max.value++;
1708 estate_set_fuzzy_max(left_true_state, hard_max);
1709 }
1710 break;
1711 case SPECIAL_EQUAL:
1712 if (get_hard_max(left, &hard_max))
1713 estate_set_fuzzy_max(right_true_state, hard_max);
1714 if (get_hard_max(right, &hard_max))
1715 estate_set_fuzzy_max(left_true_state, hard_max);
1716 break;
1717 }
1718
1719 if (get_hard_max(left, &hard_max)) {
1720 estate_set_hard_max(left_true_state);
1721 estate_set_hard_max(left_false_state);
1722 }
1723 if (get_hard_max(right, &hard_max)) {
1724 estate_set_hard_max(right_true_state);
1725 estate_set_hard_max(right_false_state);
1726 }
1727
1728 if (left_postop == SPECIAL_INCREMENT) {
1729 left_true_state = increment_state(left_true_state);
1730 left_false_state = increment_state(left_false_state);
1731 }
1732 if (left_postop == SPECIAL_DECREMENT) {
1733 left_true_state = decrement_state(left_true_state);
1734 left_false_state = decrement_state(left_false_state);
1735 }
1736 if (right_postop == SPECIAL_INCREMENT) {
1737 right_true_state = increment_state(right_true_state);
1738 right_false_state = increment_state(right_false_state);
1739 }
1740 if (right_postop == SPECIAL_DECREMENT) {
1741 right_true_state = decrement_state(right_true_state);
1742 right_false_state = decrement_state(right_false_state);
1743 }
1744
1745 if (estate_rl(left_true_state) && estates_equiv(left_true_state, left_false_state)) {
1746 left_true_state = NULL;
1747 left_false_state = NULL;
1748 }
1749
1750 if (estate_rl(right_true_state) && estates_equiv(right_true_state, right_false_state)) {
1751 right_true_state = NULL;
1752 right_false_state = NULL;
1753 }
1754
1755 /* Don't introduce new states for known true/false conditions */
1756 if (rl_equiv(left_orig, estate_rl(left_true_state)))
1757 left_true_state = NULL;
1758 if (rl_equiv(left_orig, estate_rl(left_false_state)))
1759 left_false_state = NULL;
1760 if (rl_equiv(right_orig, estate_rl(right_true_state)))
1761 right_true_state = NULL;
1762 if (rl_equiv(right_orig, estate_rl(right_false_state)))
1763 right_false_state = NULL;
1764
1765 set_extra_expr_true_false(left, left_true_state, left_false_state);
1766 set_extra_expr_true_false(right, right_true_state, right_false_state);
1767 }
1768
1769 static int is_simple_math(struct expression *expr)
1770 {
1771 if (!expr)
1772 return 0;
1773 if (expr->type != EXPR_BINOP)
1774 return 0;
1775 switch (expr->op) {
1776 case '+':
1777 case '-':
1778 case '*':
1779 return 1;
1780 }
1781 return 0;
1782 }
1783
1784 static int flip_op(int op)
1785 {
1786 /* We only care about simple math */
1787 switch (op) {
1788 case '+':
1789 return '-';
1790 case '-':
1791 return '+';
1792 case '*':
1793 return '/';
1794 }
1795 return 0;
1796 }
1797
1798 static void move_known_to_rl(struct expression **expr_p, struct range_list **rl_p)
1799 {
1800 struct expression *expr = *expr_p;
1801 struct range_list *rl = *rl_p;
1802 sval_t sval;
1803
1804 if (!is_simple_math(expr))
1805 return;
1806
1807 if (get_implied_value(expr->right, &sval)) {
1808 *expr_p = expr->left;
1809 *rl_p = rl_binop(rl, flip_op(expr->op), alloc_rl(sval, sval));
1810 move_known_to_rl(expr_p, rl_p);
1811 return;
1812 }
1813 if (expr->op == '-')
1814 return;
1815 if (get_implied_value(expr->left, &sval)) {
1816 *expr_p = expr->right;
1817 *rl_p = rl_binop(rl, flip_op(expr->op), alloc_rl(sval, sval));
1818 move_known_to_rl(expr_p, rl_p);
1819 return;
1820 }
1821 }
1822
1823 static void move_known_values(struct expression **left_p, struct expression **right_p)
1824 {
1825 struct expression *left = *left_p;
1826 struct expression *right = *right_p;
1827 sval_t sval, dummy;
1828
1829 if (get_implied_value(left, &sval)) {
1830 if (!is_simple_math(right))
1831 return;
1832 if (get_implied_value(right, &dummy))
1833 return;
1834 if (right->op == '*') {
1835 sval_t divisor;
1836
1837 if (!get_value(right->right, &divisor))
1838 return;
1839 if (divisor.value == 0)
1840 return;
1841 *left_p = binop_expression(left, invert_op(right->op), right->right);
1842 *right_p = right->left;
1843 return;
1844 }
1845 if (right->op == '+' && get_value(right->left, &sval)) {
1846 *left_p = binop_expression(left, invert_op(right->op), right->left);
1847 *right_p = right->right;
1848 return;
1849 }
1850 if (get_value(right->right, &sval)) {
1851 *left_p = binop_expression(left, invert_op(right->op), right->right);
1852 *right_p = right->left;
1853 return;
1854 }
1855 return;
1856 }
1857 if (get_implied_value(right, &sval)) {
1858 if (!is_simple_math(left))
1859 return;
1860 if (get_implied_value(left, &dummy))
1861 return;
1862 if (left->op == '*') {
1863 sval_t divisor;
1864
1865 if (!get_value(left->right, &divisor))
1866 return;
1867 if (divisor.value == 0)
1868 return;
1869 *right_p = binop_expression(right, invert_op(left->op), left->right);
1870 *left_p = left->left;
1871 return;
1872 }
1873 if (left->op == '+' && get_value(left->left, &sval)) {
1874 *right_p = binop_expression(right, invert_op(left->op), left->left);
1875 *left_p = left->right;
1876 return;
1877 }
1878
1879 if (get_value(left->right, &sval)) {
1880 *right_p = binop_expression(right, invert_op(left->op), left->right);
1881 *left_p = left->left;
1882 return;
1883 }
1884 return;
1885 }
1886 }
1887
1888 /*
1889 * The reason for do_simple_algebra() is to solve things like:
1890 * if (foo > 66 || foo + bar > 64) {
1891 * "foo" is not really a known variable so it won't be handled by
1892 * move_known_variables() but it's a super common idiom.
1893 *
1894 */
1895 static int do_simple_algebra(struct expression **left_p, struct expression **right_p)
1896 {
1897 struct expression *left = *left_p;
1898 struct expression *right = *right_p;
1899 struct range_list *rl;
1900 sval_t tmp;
1901
1902 if (left->type != EXPR_BINOP || left->op != '+')
1903 return 0;
1904 if (can_integer_overflow(get_type(left), left))
1905 return 0;
1906 if (!get_implied_value(right, &tmp))
1907 return 0;
1908
1909 if (!get_implied_value(left->left, &tmp) &&
1910 get_implied_rl(left->left, &rl) &&
1911 !is_whole_rl(rl)) {
1912 *right_p = binop_expression(right, '-', left->left);
1913 *left_p = left->right;
1914 return 1;
1915 }
1916 if (!get_implied_value(left->right, &tmp) &&
1917 get_implied_rl(left->right, &rl) &&
1918 !is_whole_rl(rl)) {
1919 *right_p = binop_expression(right, '-', left->right);
1920 *left_p = left->left;
1921 return 1;
1922 }
1923
1924 return 0;
1925 }
1926
1927 static int match_func_comparison(struct expression *expr)
1928 {
1929 struct expression *left = strip_expr(expr->left);
1930 struct expression *right = strip_expr(expr->right);
1931
1932 if (left->type == EXPR_CALL || right->type == EXPR_CALL) {
1933 function_comparison(left, expr->op, right);
1934 return 1;
1935 }
1936
1937 return 0;
1938 }
1939
1940 /* Handle conditions like "if (foo + bar < foo) {" */
1941 static int handle_integer_overflow_test(struct expression *expr)
1942 {
1943 struct expression *left, *right;
1944 struct symbol *type;
1945 sval_t left_min, right_min, min, max;
1946
1947 if (expr->op != '<' && expr->op != SPECIAL_UNSIGNED_LT)
1948 return 0;
1949
1950 left = strip_parens(expr->left);
1951 right = strip_parens(expr->right);
1952
1953 if (left->op != '+')
1954 return 0;
1955
1956 type = get_type(expr);
1957 if (!type)
1958 return 0;
1959 if (type_positive_bits(type) == 32) {
1960 max.type = &uint_ctype;
1961 max.uvalue = (unsigned int)-1;
1962 } else if (type_positive_bits(type) == 64) {
1963 max.type = &ulong_ctype;
1964 max.value = (unsigned long long)-1;
1965 } else {
1966 return 0;
1967 }
1968
1969 if (!expr_equiv(left->left, right) && !expr_equiv(left->right, right))
1970 return 0;
1971
1972 get_absolute_min(left->left, &left_min);
1973 get_absolute_min(left->right, &right_min);
1974 min = sval_binop(left_min, '+', right_min);
1975
1976 type = get_type(left);
1977 min = sval_cast(type, min);
1978 max = sval_cast(type, max);
1979
1980 set_extra_chunk_true_false(left, NULL, alloc_estate_range(min, max));
1981 return 1;
1982 }
1983
1984 static void match_comparison(struct expression *expr)
1985 {
1986 struct expression *left_orig = strip_parens(expr->left);
1987 struct expression *right_orig = strip_parens(expr->right);
1988 struct expression *left, *right, *tmp;
1989 struct expression *prev;
1990 struct symbol *type;
1991 int redo, count;
1992
1993 if (match_func_comparison(expr))
1994 return;
1995
1996 type = get_type(expr);
1997 if (!type)
1998 type = &llong_ctype;
1999
2000 if (handle_integer_overflow_test(expr))
2001 return;
2002
2003 left = left_orig;
2004 right = right_orig;
2005 move_known_values(&left, &right);
2006 handle_comparison(type, left, expr->op, right);
2007
2008 left = left_orig;
2009 right = right_orig;
2010 if (do_simple_algebra(&left, &right))
2011 handle_comparison(type, left, expr->op, right);
2012
2013 prev = get_assigned_expr(left_orig);
2014 if (is_simple_math(prev) && !has_variable(prev, left_orig)) {
2015 left = prev;
2016 right = right_orig;
2017 move_known_values(&left, &right);
2018 handle_comparison(type, left, expr->op, right);
2019 }
2020
2021 prev = get_assigned_expr(right_orig);
2022 if (is_simple_math(prev) && !has_variable(prev, right_orig)) {
2023 left = left_orig;
2024 right = prev;
2025 move_known_values(&left, &right);
2026 handle_comparison(type, left, expr->op, right);
2027 }
2028
2029 redo = 0;
2030 left = left_orig;
2031 right = right_orig;
2032 if (get_last_expr_from_expression_stmt(left_orig)) {
2033 left = get_last_expr_from_expression_stmt(left_orig);
2034 redo = 1;
2035 }
2036 if (get_last_expr_from_expression_stmt(right_orig)) {
2037 right = get_last_expr_from_expression_stmt(right_orig);
2038 redo = 1;
2039 }
2040
2041 if (!redo)
2042 return;
2043
2044 count = 0;
2045 while ((tmp = get_assigned_expr(left))) {
2046 if (count++ > 3)
2047 break;
2048 left = strip_expr(tmp);
2049 }
2050 count = 0;
2051 while ((tmp = get_assigned_expr(right))) {
2052 if (count++ > 3)
2053 break;
2054 right = strip_expr(tmp);
2055 }
2056
2057 handle_comparison(type, left, expr->op, right);
2058 }
2059
2060 static sval_t get_high_mask(sval_t known)
2061 {
2062 sval_t ret;
2063 int i;
2064
2065 ret = known;
2066 ret.value = 0;
2067
2068 for (i = type_bits(known.type) - 1; i >= 0; i--) {
2069 if (known.uvalue & (1ULL << i))
2070 ret.uvalue |= (1ULL << i);
2071 else
2072 return ret;
2073
2074 }
2075 return ret;
2076 }
2077
2078 static bool handle_bit_test(struct expression *expr)
2079 {
2080 struct range_list *orig_rl, *rl;
2081 struct expression *shift, *mask, *var;
2082 struct bit_info *bit_info;
2083 sval_t sval;
2084 sval_t high = { .type = &int_ctype };
2085 sval_t low = { .type = &int_ctype };
2086
2087 shift = strip_expr(expr->right);
2088 mask = strip_expr(expr->left);
2089 if (shift->type != EXPR_BINOP || shift->op != SPECIAL_LEFTSHIFT) {
2090 shift = strip_expr(expr->left);
2091 mask = strip_expr(expr->right);
2092 if (shift->type != EXPR_BINOP || shift->op != SPECIAL_LEFTSHIFT)
2093 return false;
2094 }
2095 if (!get_implied_value(shift->left, &sval) || sval.value != 1)
2096 return false;
2097 var = strip_expr(shift->right);
2098
2099 bit_info = get_bit_info(mask);
2100 if (!bit_info)
2101 return false;
2102 if (!bit_info->possible)
2103 return false;
2104
2105 get_absolute_rl(var, &orig_rl);
2106 if (sval_is_negative(rl_min(orig_rl)) ||
2107 rl_max(orig_rl).uvalue > type_bits(get_type(shift->left)))
2108 return false;
2109
2110 low.value = ffsll(bit_info->possible);
2111 high.value = sm_fls64(bit_info->possible);
2112 rl = alloc_rl(low, high);
2113 rl = cast_rl(get_type(var), rl);
2114 rl = rl_intersection(orig_rl, rl);
2115 if (!rl)
2116 return false;
2117
2118 set_extra_expr_true_false(shift->right, alloc_estate_rl(rl), NULL);
2119
2120 return true;
2121 }
2122
2123 static void handle_AND_op(struct expression *var, sval_t known)
2124 {
2125 struct range_list *orig_rl;
2126 struct range_list *true_rl = NULL;
2127 struct range_list *false_rl = NULL;
2128 int bit;
2129 sval_t low_mask = known;
2130 sval_t high_mask;
2131 sval_t max;
2132
2133 get_absolute_rl(var, &orig_rl);
2134
2135 if (known.value > 0) {
2136 bit = ffsll(known.value) - 1;
2137 low_mask.uvalue = (1ULL << bit) - 1;
2138 true_rl = remove_range(orig_rl, sval_type_val(known.type, 0), low_mask);
2139 }
2140 high_mask = get_high_mask(known);
2141 if (high_mask.value) {
2142 bit = ffsll(high_mask.value) - 1;
2143 low_mask.uvalue = (1ULL << bit) - 1;
2144
2145 false_rl = orig_rl;
2146 if (sval_is_negative(rl_min(orig_rl)))
2147 false_rl = remove_range(false_rl, sval_type_min(known.type), sval_type_val(known.type, -1));
2148 false_rl = remove_range(false_rl, low_mask, sval_type_max(known.type));
2149 if (type_signed(high_mask.type) && type_unsigned(rl_type(false_rl))) {
2150 false_rl = remove_range(false_rl,
2151 sval_type_val(rl_type(false_rl), sval_type_max(known.type).uvalue),
2152 sval_type_val(rl_type(false_rl), -1));
2153 }
2154 } else if (known.value == 1 &&
2155 get_hard_max(var, &max) &&
2156 sval_cmp(max, rl_max(orig_rl)) == 0 &&
2157 max.value & 1) {
2158 false_rl = remove_range(orig_rl, max, max);
2159 }
2160 set_extra_expr_true_false(var,
2161 true_rl ? alloc_estate_rl(true_rl) : NULL,
2162 false_rl ? alloc_estate_rl(false_rl) : NULL);
2163 }
2164
2165 static void handle_AND_condition(struct expression *expr)
2166 {
2167 sval_t known;
2168
2169 if (handle_bit_test(expr))
2170 return;
2171
2172 if (get_implied_value(expr->left, &known))
2173 handle_AND_op(expr->right, known);
2174 else if (get_implied_value(expr->right, &known))
2175 handle_AND_op(expr->left, known);
2176 }
2177
2178 static void handle_MOD_condition(struct expression *expr)
2179 {
2180 struct range_list *orig_rl;
2181 struct range_list *true_rl;
2182 struct range_list *false_rl = NULL;
2183 sval_t right;
2184 sval_t zero = {
2185 .value = 0,
2186 };
2187
2188 if (!get_implied_value(expr->right, &right) || right.value == 0)
2189 return;
2190 get_absolute_rl(expr->left, &orig_rl);
2191
2192 zero.type = rl_type(orig_rl);
2193
2194 /* We're basically dorking around the min and max here */
2195 true_rl = remove_range(orig_rl, zero, zero);
2196 if (!sval_is_max(rl_max(true_rl)) &&
2197 !(rl_max(true_rl).value % right.value))
2198 true_rl = remove_range(true_rl, rl_max(true_rl), rl_max(true_rl));
2199
2200 if (rl_equiv(true_rl, orig_rl))
2201 true_rl = NULL;
2202
2203 if (sval_is_positive(rl_min(orig_rl)) &&
2204 (rl_max(orig_rl).value - rl_min(orig_rl).value) / right.value < 5) {
2205 sval_t add;
2206 int i;
2207
2208 add = rl_min(orig_rl);
2209 add.value += right.value - (add.value % right.value);
2210 add.value -= right.value;
2211
2212 for (i = 0; i < 5; i++) {
2213 add.value += right.value;
2214 if (add.value > rl_max(orig_rl).value)
2215 break;
2216 add_range(&false_rl, add, add);
2217 }
2218 } else {
2219 if (rl_min(orig_rl).uvalue != 0 &&
2220 rl_min(orig_rl).uvalue < right.uvalue) {
2221 sval_t chop = right;
2222 chop.value--;
2223 false_rl = remove_range(orig_rl, zero, chop);
2224 }
2225
2226 if (!sval_is_max(rl_max(orig_rl)) &&
2227 (rl_max(orig_rl).value % right.value)) {
2228 sval_t chop = rl_max(orig_rl);
2229 chop.value -= chop.value % right.value;
2230 chop.value++;
2231 if (!false_rl)
2232 false_rl = clone_rl(orig_rl);
2233 false_rl = remove_range(false_rl, chop, rl_max(orig_rl));
2234 }
2235 }
2236
2237 set_extra_expr_true_false(expr->left,
2238 true_rl ? alloc_estate_rl(true_rl) : NULL,
2239 false_rl ? alloc_estate_rl(false_rl) : NULL);
2240 }
2241
2242 /* this is actually hooked from smatch_implied.c... it's hacky, yes */
2243 void __extra_match_condition(struct expression *expr)
2244 {
2245 expr = strip_expr(expr);
2246 switch (expr->type) {
2247 case EXPR_CALL:
2248 function_comparison(expr, SPECIAL_NOTEQUAL, zero_expr());
2249 return;
2250 case EXPR_PREOP:
2251 case EXPR_SYMBOL:
2252 case EXPR_DEREF:
2253 handle_comparison(get_type(expr), expr, SPECIAL_NOTEQUAL, zero_expr());
2254 return;
2255 case EXPR_COMPARE:
2256 match_comparison(expr);
2257 return;
2258 case EXPR_ASSIGNMENT:
2259 __extra_match_condition(expr->left);
2260 return;
2261 case EXPR_BINOP:
2262 if (expr->op == '&')
2263 handle_AND_condition(expr);
2264 if (expr->op == '%')
2265 handle_MOD_condition(expr);
2266 return;
2267 }
2268 }
2269
2270 static void assume_indexes_are_valid(struct expression *expr)
2271 {
2272 struct expression *array_expr;
2273 int array_size;
2274 struct expression *offset;
2275 struct symbol *offset_type;
2276 struct range_list *rl_before;
2277 struct range_list *rl_after;
2278 struct range_list *filter = NULL;
2279 sval_t size;
2280
2281 expr = strip_expr(expr);
2282 if (!is_array(expr))
2283 return;
2284
2285 offset = get_array_offset(expr);
2286 offset_type = get_type(offset);
2287 if (offset_type && type_signed(offset_type)) {
2288 filter = alloc_rl(sval_type_min(offset_type),
2289 sval_type_val(offset_type, -1));
2290 }
2291
2292 array_expr = get_array_base(expr);
2293 array_size = get_real_array_size(array_expr);
2294 if (array_size > 1) {
2295 size = sval_type_val(offset_type, array_size);
2296 add_range(&filter, size, sval_type_max(offset_type));
2297 }
2298
2299 if (!filter)
2300 return;
2301 get_absolute_rl(offset, &rl_before);
2302 rl_after = rl_filter(rl_before, filter);
2303 if (rl_equiv(rl_before, rl_after))
2304 return;
2305 set_extra_expr_nomod(offset, alloc_estate_rl(rl_after));
2306 }
2307
2308 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
2309 int implied_not_equal(struct expression *expr, long long val)
2310 {
2311 return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
2312 }
2313
2314 int implied_not_equal_name_sym(char *name, struct symbol *sym, long long val)
2315 {
2316 struct smatch_state *estate;
2317
2318 estate = get_state(SMATCH_EXTRA, name, sym);
2319 if (!estate)
2320 return 0;
2321 if (!rl_has_sval(estate_rl(estate), sval_type_val(estate_type(estate), 0)))
2322 return 1;
2323 return 0;
2324 }
2325
2326 bool is_noderef_ptr(struct expression *expr)
2327 {
2328 struct range_list *rl;
2329
2330 if (!get_implied_rl(expr, &rl))
2331 return false;
2332 return is_noderef_ptr_rl(rl);
2333 }
2334
2335 static int parent_is_err_or_null_var_sym_helper(const char *name, struct symbol *sym, bool check_err_ptr)
2336 {
2337 struct smatch_state *state;
2338 char buf[256];
2339 char *start;
2340 int len;
2341
2342 strncpy(buf, name, sizeof(buf) - 1);
2343 buf[sizeof(buf) - 1] = '\0';
2344
2345 start = &buf[0];
2346 while (*start == '*') {
2347 start++;
2348 state = __get_state(SMATCH_EXTRA, start, sym);
2349 if (!state)
2350 continue;
2351 if (!estate_rl(state))
2352 return 1;
2353 if (is_noderef_ptr_rl(estate_rl(state)))
2354 return 1;
2355 }
2356
2357 start = &buf[0];
2358 while (*start == '&')
2359 start++;
2360
2361 len = strlen(start);
2362 while (true) {
2363 while (len > 0) {
2364 len--;
2365 if (start[len] == '-' ||
2366 start[len] == '.') {
2367 start[len] = '\0';
2368 break;
2369 }
2370 }
2371 if (len == 0)
2372 return 0;
2373 state = __get_state(SMATCH_EXTRA, start, sym);
2374 if (!state)
2375 continue;
2376 if (is_noderef_ptr_rl(estate_rl(state)))
2377 return 1;
2378 }
2379 }
2380
2381 int parent_is_null_var_sym(const char *name, struct symbol *sym)
2382 {
2383 return parent_is_err_or_null_var_sym_helper(name, sym, false);
2384 }
2385
2386 int parent_is_err_or_null_var_sym(const char *name, struct symbol *sym)
2387 {
2388 return parent_is_err_or_null_var_sym_helper(name, sym, (option_project == PROJ_KERNEL));
2389 }
2390
2391 int parent_is_null(struct expression *expr)
2392 {
2393 struct symbol *sym;
2394 char *var;
2395 int ret = 0;
2396
2397 expr = strip_expr(expr);
2398 var = expr_to_var_sym(expr, &sym);
2399 if (!var || !sym)
2400 goto free;
2401 ret = parent_is_null_var_sym(var, sym);
2402 free:
2403 free_string(var);
2404 return ret;
2405 }
2406
2407 static int param_used_callback(void *found, int argc, char **argv, char **azColName)
2408 {
2409 *(int *)found = 1;
2410 return 0;
2411 }
2412
2413 static int is_kzalloc_info(struct sm_state *sm)
2414 {
2415 sval_t sval;
2416
2417 /*
2418 * kzalloc() information is treated as special because so there is just
2419 * a lot of stuff initialized to zero and it makes building the database
2420 * take hours and hours.
2421 *
2422 * In theory, we should just remove this line and not pass any unused
2423 * information, but I'm not sure enough that this code works so I want
2424 * to hold off on that for now.
2425 */
2426 if (!estate_get_single_value(sm->state, &sval))
2427 return 0;
2428 if (sval.value != 0)
2429 return 0;
2430 return 1;
2431 }
2432
2433 static int is_really_long(struct sm_state *sm)
2434 {
2435 const char *p;
2436 int cnt = 0;
2437
2438 p = sm->name;
2439 while ((p = strstr(p, "->"))) {
2440 p += 2;
2441 cnt++;
2442 }
2443
2444 if (cnt < 3 ||
2445 strlen(sm->name) < 40)
2446 return 0;
2447 return 1;
2448 }
2449
2450 static int filter_unused_param_value_info(struct expression *call, int param, char *printed_name, struct sm_state *sm)
2451 {
2452 int found = 0;
2453
2454 /* for function pointers assume everything is used */
2455 if (call->fn->type != EXPR_SYMBOL)
2456 return 0;
2457
2458 if (strcmp(printed_name, "$") == 0 ||
2459 strcmp(printed_name, "*$") == 0)
2460 return 0;
2461
2462 /*
2463 * This is to handle __builtin_mul_overflow(). In an ideal world we
2464 * would only need this for invalid code.
2465 *
2466 */
2467 if (!call->fn->symbol)
2468 return 0;
2469
2470 if (!is_kzalloc_info(sm) && !is_really_long(sm))
2471 return 0;
2472
2473 run_sql(&param_used_callback, &found,
2474 "select * from return_implies where %s and type = %d and parameter = %d and key = '%s';",
2475 get_static_filter(call->fn->symbol), PARAM_USED, param, printed_name);
2476 if (found)
2477 return 0;
2478
2479 /* If the database is not built yet, then assume everything is used */
2480 run_sql(&param_used_callback, &found,
2481 "select * from return_implies where %s and type = %d;",
2482 get_static_filter(call->fn->symbol), PARAM_USED);
2483 if (!found)
2484 return 0;
2485
2486 return 1;
2487 }
2488
2489 struct range_list *intersect_with_real_abs_var_sym(const char *name, struct symbol *sym, struct range_list *start)
2490 {
2491 struct smatch_state *state;
2492
2493 /*
2494 * Here is the difference between implied value and real absolute, say
2495 * you have:
2496 *
2497 * int a = (u8)x;
2498 *
2499 * Then you know that a is 0-255. That's real absolute. But you don't
2500 * know for sure that it actually goes up to 255. So it's not implied.
2501 * Implied indicates a degree of certainty.
2502 *
2503 * But then say you cap "a" at 8. That means you know it goes up to
2504 * 8. So now the implied value is s32min-8. But you can combine it
2505 * with the real absolute to say that actually it's 0-8.
2506 *
2507 * We are combining it here. But now that I think about it, this is
2508 * probably not the ideal place to combine it because it should proably
2509 * be done earlier. Oh well, this is an improvement on what was there
2510 * before so I'm going to commit this code.
2511 *
2512 */
2513
2514 state = get_real_absolute_state_var_sym(name, sym);
2515 if (!state || !estate_rl(state))
2516 return start;
2517
2518 return rl_intersection(estate_rl(state), start);
2519 }
2520
2521 struct range_list *intersect_with_real_abs_expr(struct expression *expr, struct range_list *start)
2522 {
2523 struct smatch_state *state;
2524 struct range_list *abs_rl;
2525
2526 state = get_real_absolute_state(expr);
2527 if (!state || !estate_rl(state))
2528 return start;
2529
2530 abs_rl = cast_rl(rl_type(start), estate_rl(state));
2531 return rl_intersection(abs_rl, start);
2532 }
2533
2534 static void caller_info_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm)
2535 {
2536 struct range_list *rl;
2537 sval_t dummy;
2538
2539 if (estate_is_whole(sm->state) || !estate_rl(sm->state))
2540 return;
2541 if (filter_unused_param_value_info(call, param, printed_name, sm))
2542 return;
2543 rl = estate_rl(sm->state);
2544 rl = intersect_with_real_abs_var_sym(sm->name, sm->sym, rl);
2545 if (!rl)
2546 return;
2547 sql_insert_caller_info(call, PARAM_VALUE, param, printed_name, show_rl(rl));
2548 if (!estate_get_single_value(sm->state, &dummy)) {
2549 if (estate_has_hard_max(sm->state))
2550 sql_insert_caller_info(call, HARD_MAX, param, printed_name,
2551 sval_to_str(estate_max(sm->state)));
2552 if (estate_has_fuzzy_max(sm->state))
2553 sql_insert_caller_info(call, FUZZY_MAX, param, printed_name,
2554 sval_to_str(estate_get_fuzzy_max(sm->state)));
2555 }
2556 }
2557
2558 static void returned_struct_members(int return_id, char *return_ranges, struct expression *expr)
2559 {
2560 struct symbol *returned_sym;
2561 char *returned_name;
2562 struct sm_state *sm;
2563 char *compare_str;
2564 char name_buf[256];
2565 char val_buf[256];
2566 int len;
2567
2568 // FIXME handle *$
2569
2570 if (!is_pointer(expr))
2571 return;
2572 if (return_ranges && strstr(return_ranges, "[==$"))
2573 return;
2574
2575 returned_name = expr_to_var_sym(expr, &returned_sym);
2576 if (!returned_name || !returned_sym)
2577 goto free;
2578 len = strlen(returned_name);
2579
2580 FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
2581 if (!estate_rl(sm->state))
2582 continue;
2583 if (returned_sym != sm->sym)
2584 continue;
2585 if (strncmp(returned_name, sm->name, len) != 0)
2586 continue;
2587 if (sm->name[len] != '-')
2588 continue;
2589
2590 snprintf(name_buf, sizeof(name_buf), "$%s", sm->name + len);
2591
2592 compare_str = name_sym_to_param_comparison(sm->name, sm->sym);
2593 if (!compare_str && estate_is_whole(sm->state))
2594 continue;
2595 snprintf(val_buf, sizeof(val_buf), "%s%s", sm->state->name, compare_str ?: "");
2596
2597 sql_insert_return_states(return_id, return_ranges, PARAM_VALUE,
2598 -1, name_buf, val_buf);
2599 } END_FOR_EACH_SM(sm);
2600
2601 free:
2602 free_string(returned_name);
2603 }
2604
2605 static void db_limited_before(void)
2606 {
2607 unmatched_stree = clone_stree(__get_cur_stree());
2608 }
2609
2610 static void db_limited_after(void)
2611 {
2612 free_stree(&unmatched_stree);
2613 }
2614
2615 static int basically_the_same(struct range_list *orig, struct range_list *new)
2616 {
2617 if (type_is_ptr(rl_type(orig)) &&
2618 is_whole_ptr_rl(orig) &&
2619 is_whole_ptr_rl(new))
2620 return true;
2621
2622 return rl_equiv(orig, new);
2623 }
2624
2625 static void db_param_limit_binops(struct expression *arg, char *key, struct range_list *rl)
2626 {
2627 struct range_list *left_rl;
2628 sval_t zero = { .type = rl_type(rl), };
2629 sval_t sval;
2630
2631 if (strcmp(key, "$") != 0)
2632 return;
2633 if (arg->op != '*')
2634 return;
2635 if (!get_implied_value(arg->right, &sval))
2636 return;
2637 if (can_integer_overflow(get_type(arg), arg))
2638 return;
2639
2640 left_rl = rl_binop(rl, '/', alloc_rl(sval, sval));
2641 if (!rl_has_sval(rl, zero))
2642 left_rl = remove_range(left_rl, zero, zero);
2643
2644 set_extra_expr_nomod(arg->left, alloc_estate_rl(left_rl));
2645 }
2646
2647 static void db_param_limit_filter(struct expression *expr, int param, char *key, char *value, enum info_type op)
2648 {
2649 struct expression *arg;
2650 char *name;
2651 struct symbol *sym;
2652 struct var_sym_list *vsl = NULL;
2653 struct sm_state *sm;
2654 struct symbol *compare_type, *var_type;
2655 struct range_list *rl;
2656 struct range_list *limit;
2657 struct range_list *new;
2658 char *other_name;
2659 struct symbol *other_sym;
2660
2661 while (expr->type == EXPR_ASSIGNMENT)
2662 expr = strip_expr(expr->right);
2663 if (expr->type != EXPR_CALL)
2664 return;
2665
2666 arg = get_argument_from_call_expr(expr->args, param);
2667 if (!arg)
2668 return;
2669
2670 if (strcmp(key, "$") == 0)
2671 compare_type = get_arg_type(expr->fn, param);
2672 else
2673 compare_type = get_member_type_from_key(arg, key);
2674
2675 call_results_to_rl(expr, compare_type, value, &limit);
2676 if (strcmp(key, "$") == 0)
2677 move_known_to_rl(&arg, &limit);
2678 name = get_chunk_from_key(arg, key, &sym, &vsl);
2679 if (!name)
2680 return;
2681 if (op != PARAM_LIMIT && !sym)
2682 goto free;
2683
2684 sm = get_sm_state(SMATCH_EXTRA, name, sym);
2685 if (sm)
2686 rl = estate_rl(sm->state);
2687 else
2688 rl = alloc_whole_rl(compare_type);
2689
2690 if (op == PARAM_LIMIT && !rl_fits_in_type(rl, compare_type))
2691 goto free;
2692
2693 new = rl_intersection(rl, limit);
2694
2695 var_type = get_member_type_from_key(arg, key);
2696 new = cast_rl(var_type, new);
2697
2698 /* We want to preserve the implications here */
2699 if (sm && basically_the_same(rl, new))
2700 goto free;
2701 other_name = get_other_name_sym(name, sym, &other_sym);
2702
2703 if (op == PARAM_LIMIT)
2704 set_extra_nomod_vsl(name, sym, vsl, NULL, alloc_estate_rl(new));
2705 else
2706 set_extra_mod(name, sym, NULL, alloc_estate_rl(new));
2707
2708 if (other_name && other_sym) {
2709 if (op == PARAM_LIMIT)
2710 set_extra_nomod_vsl(other_name, other_sym, vsl, NULL, alloc_estate_rl(new));
2711 else
2712 set_extra_mod(other_name, other_sym, NULL, alloc_estate_rl(new));
2713 }
2714
2715 if (op == PARAM_LIMIT && arg->type == EXPR_BINOP)
2716 db_param_limit_binops(arg, key, new);
2717 free:
2718 free_string(name);
2719 }
2720
2721 static void db_param_limit(struct expression *expr, int param, char *key, char *value)
2722 {
2723 db_param_limit_filter(expr, param, key, value, PARAM_LIMIT);
2724 }
2725
2726 static void db_param_filter(struct expression *expr, int param, char *key, char *value)
2727 {
2728 db_param_limit_filter(expr, param, key, value, PARAM_FILTER);
2729 }
2730
2731 static void db_param_add_set(struct expression *expr, int param, char *key, char *value, enum info_type op)
2732 {
2733 struct expression *arg, *gen_expr;
2734 char *name;
2735 char *other_name = NULL;
2736 struct symbol *sym, *other_sym;
2737 struct symbol *param_type, *arg_type;
2738 struct smatch_state *state;
2739 struct range_list *new = NULL;
2740 struct range_list *added = NULL;
2741
2742 while (expr->type == EXPR_ASSIGNMENT)
2743 expr = strip_expr(expr->right);
2744 if (expr->type != EXPR_CALL)
2745 return;
2746
2747 arg = get_argument_from_call_expr(expr->args, param);
2748 if (!arg)
2749 return;
2750
2751 arg_type = get_arg_type_from_key(expr->fn, param, arg, key);
2752 param_type = get_member_type_from_key(arg, key);
2753 if (param_type && param_type->type == SYM_STRUCT)
2754 return;
2755 name = get_variable_from_key(arg, key, &sym);
2756 if (!name || !sym)
2757 goto free;
2758 gen_expr = gen_expression_from_key(arg, key);
2759
2760 state = get_state(SMATCH_EXTRA, name, sym);
2761 if (state)
2762 new = estate_rl(state);
2763
2764 call_results_to_rl(expr, arg_type, value, &added);
2765 added = cast_rl(param_type, added);
2766 if (op == PARAM_SET)
2767 new = added;
2768 else
2769 new = rl_union(new, added);
2770
2771 other_name = get_other_name_sym_nostack(name, sym, &other_sym);
2772 set_extra_mod(name, sym, gen_expr, alloc_estate_rl(new));
2773 if (other_name && other_sym)
2774 set_extra_mod(other_name, other_sym, gen_expr, alloc_estate_rl(new));
2775 free:
2776 free_string(other_name);
2777 free_string(name);
2778 }
2779
2780 static void db_param_add(struct expression *expr, int param, char *key, char *value)
2781 {
2782 in_param_set = true;
2783 db_param_add_set(expr, param, key, value, PARAM_ADD);
2784 in_param_set = false;
2785 }
2786
2787 static void db_param_set(struct expression *expr, int param, char *key, char *value)
2788 {
2789 in_param_set = true;
2790 db_param_add_set(expr, param, key, value, PARAM_SET);
2791 in_param_set = false;
2792 }
2793
2794 static void match_lost_param(struct expression *call, int param)
2795 {
2796 struct expression *arg;
2797
2798 if (is_const_param(call->fn, param))
2799 return;
2800
2801 arg = get_argument_from_call_expr(call->args, param);
2802 if (!arg)
2803 return;
2804
2805 arg = strip_expr(arg);
2806 if (arg->type == EXPR_PREOP && arg->op == '&')
2807 set_extra_expr_mod(arg->unop, alloc_estate_whole(get_type(arg->unop)));
2808 else
2809 ; /* if pointer then set struct members, maybe?*/
2810 }
2811
2812 static void db_param_value(struct expression *expr, int param, char *key, char *value)
2813 {
2814 struct expression *call;
2815 char *name;
2816 struct symbol *sym;
2817 struct symbol *type;
2818 struct range_list *rl = NULL;
2819
2820 if (param != -1)
2821 return;
2822
2823 call = expr;
2824 while (call->type == EXPR_ASSIGNMENT)
2825 call = strip_expr(call->right);
2826 if (call->type != EXPR_CALL)
2827 return;
2828
2829 type = get_member_type_from_key(expr->left, key);
2830 name = get_variable_from_key(expr->left, key, &sym);
2831 if (!name || !sym)
2832 goto free;
2833
2834 call_results_to_rl(call, type, value, &rl);
2835
2836 set_extra_mod(name, sym, NULL, alloc_estate_rl(rl));
2837 free:
2838 free_string(name);
2839 }
2840
2841 static void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
2842 {
2843 struct expression *expr;
2844 struct range_list *rl = NULL;
2845 struct smatch_state *state;
2846 struct symbol *type;
2847 char *key_orig = key;
2848 char *fullname;
2849 sval_t dummy;
2850
2851 expr = symbol_expression(sym);
2852 fullname = get_variable_from_key(expr, key, NULL);
2853 if (!fullname)
2854 return;
2855
2856 type = get_member_type_from_key(expr, key_orig);
2857 str_to_rl(type, value, &rl);
2858 state = alloc_estate_rl(rl);
2859 if (estate_get_single_value(state, &dummy))
2860 estate_set_hard_max(state);
2861 set_state(SMATCH_EXTRA, fullname, sym, state);
2862 }
2863
2864 static void set_param_fuzzy_max(const char *name, struct symbol *sym, char *key, char *value)
2865 {
2866 struct expression *expr;
2867 struct range_list *rl = NULL;
2868 struct smatch_state *state;
2869 struct symbol *type;
2870 char *fullname;
2871 sval_t max;
2872
2873 expr = symbol_expression(sym);
2874 fullname = get_variable_from_key(expr, key, NULL);
2875 if (!fullname)
2876 return;
2877
2878 state = get_state(SMATCH_EXTRA, fullname, sym);
2879 if (!state)
2880 return;
2881 type = estate_type(state);
2882 str_to_rl(type, value, &rl);
2883 if (!rl_to_sval(rl, &max))
2884 return;
2885 estate_set_fuzzy_max(state, max);
2886 }
2887
2888 static void set_param_hard_max(const char *name, struct symbol *sym, char *key, char *value)
2889 {
2890 struct smatch_state *state;
2891 struct expression *expr;
2892 char *fullname;
2893
2894 expr = symbol_expression(sym);
2895 fullname = get_variable_from_key(expr, key, NULL);
2896 if (!fullname)
2897 return;
2898
2899 state = get_state(SMATCH_EXTRA, fullname, sym);
2900 if (!state)
2901 return;
2902 estate_set_hard_max(state);
2903 }
2904
2905 static struct sm_state *get_sm_from_call(struct expression *expr)
2906 {
2907 char buf[32];
2908
2909 if (is_fake_call(expr))
2910 return NULL;
2911
2912 snprintf(buf, sizeof(buf), "return %p", expr);
2913 return get_sm_state(SMATCH_EXTRA, buf, NULL);
2914 }
2915
2916 struct sm_state *get_extra_sm_state(struct expression *expr)
2917 {
2918 char *name;
2919 struct symbol *sym;
2920 struct sm_state *ret = NULL;
2921
2922 expr = strip_expr(expr);
2923 if (!expr)
2924 return NULL;
2925
2926 if (expr->type == EXPR_CALL)
2927 return get_sm_from_call(expr);
2928
2929 name = expr_to_known_chunk_sym(expr, &sym);
2930 if (!name)
2931 goto free;
2932
2933 ret = get_sm_state(SMATCH_EXTRA, name, sym);
2934 free:
2935 free_string(name);
2936 return ret;
2937 }
2938
2939 struct smatch_state *get_extra_state(struct expression *expr)
2940 {
2941 struct sm_state *sm;
2942
2943 sm = get_extra_sm_state(expr);
2944 if (!sm)
2945 return NULL;
2946 return sm->state;
2947 }
2948
2949 void register_smatch_extra(int id)
2950 {
2951 my_id = id;
2952
2953 set_dynamic_states(my_id);
2954 add_merge_hook(my_id, &merge_estates);
2955 add_unmatched_state_hook(my_id, &unmatched_state);
2956 select_caller_info_hook(set_param_value, PARAM_VALUE);
2957 select_caller_info_hook(set_param_fuzzy_max, FUZZY_MAX);
2958 select_caller_info_hook(set_param_hard_max, HARD_MAX);
2959 select_return_states_before(&db_limited_before);
2960 select_return_states_hook(PARAM_LIMIT, &db_param_limit);
2961 select_return_states_hook(PARAM_FILTER, &db_param_filter);
2962 select_return_states_hook(PARAM_ADD, &db_param_add);
2963 select_return_states_hook(PARAM_SET, &db_param_set);
2964 add_lost_param_hook(&match_lost_param);
2965 select_return_states_hook(PARAM_VALUE, &db_param_value);
2966 select_return_states_after(&db_limited_after);
2967 }
2968
2969 static void match_link_modify(struct sm_state *sm, struct expression *mod_expr)
2970 {
2971 struct var_sym_list *links;
2972 struct var_sym *tmp;
2973 struct smatch_state *state;
2974
2975 links = sm->state->data;
2976
2977 FOR_EACH_PTR(links, tmp) {
2978 if (sm->sym == tmp->sym &&
2979 strcmp(sm->name, tmp->var) == 0)
2980 continue;
2981 state = get_state(SMATCH_EXTRA, tmp->var, tmp->sym);
2982 if (!state)
2983 continue;
2984 set_state(SMATCH_EXTRA, tmp->var, tmp->sym, alloc_estate_whole(estate_type(state)));
2985 } END_FOR_EACH_PTR(tmp);
2986 set_state(link_id, sm->name, sm->sym, &undefined);
2987 }
2988
2989 void register_smatch_extra_links(int id)
2990 {
2991 link_id = id;
2992 set_dynamic_states(link_id);
2993 }
2994
2995 void register_smatch_extra_late(int id)
2996 {
2997 add_merge_hook(link_id, &merge_link_states);
2998 add_modification_hook(link_id, &match_link_modify);
2999 add_hook(&match_dereferences, DEREF_HOOK);
3000 add_hook(&match_pointer_as_array, OP_HOOK);
3001 select_return_implies_hook(DEREFERENCE, &set_param_dereferenced);
3002 add_hook(&match_function_call, FUNCTION_CALL_HOOK);
3003 add_hook(&match_assign, ASSIGNMENT_HOOK);
3004 add_hook(&match_assign, GLOBAL_ASSIGNMENT_HOOK);
3005 add_hook(&unop_expr, OP_HOOK);
3006 add_hook(&asm_expr, ASM_HOOK);
3007
3008 add_caller_info_callback(my_id, caller_info_callback);
3009 add_split_return_callback(&returned_struct_members);
3010
3011 // add_hook(&assume_indexes_are_valid, OP_HOOK);
3012 }
Static analysis for C