1 /*
2 * Copyright (C) 2006 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 * You have a lists of states. kernel = locked, foo = NULL, ...
20 * When you hit an if {} else {} statement then you swap the list
21 * of states for a different list of states. The lists are stored
22 * on stacks.
23 *
24 * At the beginning of this file there are list of the stacks that
25 * we use. Each function in this file does something to one of
26 * of the stacks.
27 *
28 * So the smatch_flow.c understands code but it doesn't understand states.
29 * smatch_flow calls functions in this file. This file calls functions
30 * in smatch_slist.c which just has boring generic plumbing for handling
31 * state lists. But really it's this file where all the magic happens.
32 */
33
34 #include <stdlib.h>
35 #include <stdio.h>
36 #include "smatch.h"
37 #include "smatch_slist.h"
38 #include "smatch_extra.h"
39
40 struct smatch_state undefined = { .name = "undefined" };
41 struct smatch_state ghost = { .name = "ghost" };
42 struct smatch_state merged = { .name = "merged" };
43 struct smatch_state true_state = { .name = "true" };
44 struct smatch_state false_state = { .name = "false" };
45
46 static struct stree *cur_stree; /* current states */
47 static struct stree *fast_overlay;
48
49 static struct stree_stack *true_stack; /* states after a t/f branch */
50 static struct stree_stack *false_stack;
51 static struct stree_stack *pre_cond_stack; /* states before a t/f branch */
52
53 static struct stree_stack *cond_true_stack; /* states affected by a branch */
54 static struct stree_stack *cond_false_stack;
55
56 static struct stree_stack *fake_cur_stree_stack;
57 static int read_only;
58
59 static struct stree_stack *break_stack;
60 static struct stree_stack *fake_break_stack;
61 static struct stree_stack *switch_stack;
62 static struct range_list_stack *remaining_cases;
63 static struct stree_stack *default_stack;
64 static struct stree_stack *continue_stack;
65
66 static struct named_stree_stack *goto_stack;
67
68 static struct ptr_list *backup;
69
70 int option_debug;
71
72 void __print_cur_stree(void)
73 {
74 __print_stree(cur_stree);
75 }
76
77 int unreachable(void)
78 {
79 if (!cur_stree)
80 return 1;
81 return 0;
82 }
83
84 void __set_cur_stree_readonly(void)
85 {
86 read_only++;
87 }
88
89 void __set_cur_stree_writable(void)
90 {
91 read_only--;
92 }
93
94 struct sm_state *set_state(int owner, const char *name, struct symbol *sym, struct smatch_state *state)
95 {
96 struct sm_state *ret;
97
98 if (!name || !state)
99 return NULL;
100
101 if (read_only)
102 sm_perror("cur_stree is read only.");
103
104 if (option_debug || strcmp(check_name(owner), option_debug_check) == 0) {
105 struct smatch_state *s;
106
107 s = __get_state(owner, name, sym);
108 if (!s)
109 sm_msg("%s new [%s] '%s' %s", __func__,
110 check_name(owner), name, show_state(state));
111 else
112 sm_msg("%s change [%s] '%s' %s => %s",
113 __func__, check_name(owner), name, show_state(s),
114 show_state(state));
115 }
116
117 if (owner != -1 && unreachable())
118 return NULL;
119
120 if (fake_cur_stree_stack)
121 set_state_stree_stack(&fake_cur_stree_stack, owner, name, sym, state);
122
123 ret = set_state_stree(&cur_stree, owner, name, sym, state);
124
125 return ret;
126 }
127
128 struct sm_state *set_state_expr(int owner, struct expression *expr, struct smatch_state *state)
129 {
130 char *name;
131 struct symbol *sym;
132 struct sm_state *ret = NULL;
133
134 expr = strip_expr(expr);
135 name = expr_to_var_sym(expr, &sym);
136 if (!name || !sym)
137 goto free;
138 ret = set_state(owner, name, sym, state);
139 free:
140 free_string(name);
141 return ret;
142 }
143
144 struct stree *__swap_cur_stree(struct stree *stree)
145 {
146 struct stree *orig = cur_stree;
147
148 cur_stree = stree;
149 return orig;
150 }
151
152 void __push_fake_cur_stree(void)
153 {
154 push_stree(&fake_cur_stree_stack, NULL);
155 __save_pre_cond_states();
156 }
157
158 struct stree *__pop_fake_cur_stree(void)
159 {
160 if (!fake_cur_stree_stack)
161 sm_perror("popping too many fake cur strees.");
162 __use_pre_cond_states();
163 return pop_stree(&fake_cur_stree_stack);
164 }
165
166 void __free_fake_cur_stree(void)
167 {
168 struct stree *stree;
169
170 stree = __pop_fake_cur_stree();
171 free_stree(&stree);
172 }
173
174 void __set_fake_cur_stree_fast(struct stree *stree)
175 {
176 if (fast_overlay) {
177 sm_perror("cannot nest fast overlay");
178 return;
179 }
180 fast_overlay = stree;
181 set_fast_math_only();
182 }
183
184 void __pop_fake_cur_stree_fast(void)
185 {
186 fast_overlay = NULL;
187 clear_fast_math_only();
188 }
189
190 void __merge_stree_into_cur(struct stree *stree)
191 {
192 struct sm_state *sm;
193 struct sm_state *orig;
194 struct sm_state *merged;
195
196 FOR_EACH_SM(stree, sm) {
197 orig = get_sm_state(sm->owner, sm->name, sm->sym);
198 if (orig)
199 merged = merge_sm_states(orig, sm);
200 else
201 merged = sm;
202 __set_sm(merged);
203 } END_FOR_EACH_SM(sm);
204 }
205
206 void __set_sm(struct sm_state *sm)
207 {
208 if (read_only)
209 sm_perror("cur_stree is read only.");
210
211 if (option_debug ||
212 strcmp(check_name(sm->owner), option_debug_check) == 0) {
213 struct smatch_state *s;
214
215 s = __get_state(sm->owner, sm->name, sm->sym);
216 if (!s)
217 sm_msg("%s new %s", __func__, show_sm(sm));
218 else
219 sm_msg("%s change %s (was %s)", __func__, show_sm(sm),
220 show_state(s));
221 }
222
223 if (unreachable())
224 return;
225
226 if (fake_cur_stree_stack)
227 overwrite_sm_state_stree_stack(&fake_cur_stree_stack, sm);
228
229 overwrite_sm_state_stree(&cur_stree, sm);
230 }
231
232 void __set_sm_cur_stree(struct sm_state *sm)
233 {
234 if (read_only)
235 sm_perror("cur_stree is read only.");
236
237 if (option_debug ||
238 strcmp(check_name(sm->owner), option_debug_check) == 0) {
239 struct smatch_state *s;
240
241 s = __get_state(sm->owner, sm->name, sm->sym);
242 if (!s)
243 sm_msg("%s new %s", __func__, show_sm(sm));
244 else
245 sm_msg("%s change %s (was %s)",
246 __func__, show_sm(sm), show_state(s));
247 }
248
249 if (unreachable())
250 return;
251
252 overwrite_sm_state_stree(&cur_stree, sm);
253 }
254
255 void __set_sm_fake_stree(struct sm_state *sm)
256 {
257 if (read_only)
258 sm_perror("cur_stree is read only.");
259
260 if (option_debug ||
261 strcmp(check_name(sm->owner), option_debug_check) == 0) {
262 struct smatch_state *s;
263
264 s = __get_state(sm->owner, sm->name, sm->sym);
265 if (!s)
266 sm_msg("%s new %s", __func__, show_sm(sm));
267 else
268 sm_msg("%s change %s (was %s)",
269 __func__, show_sm(sm), show_state(s));
270 }
271
272 if (unreachable())
273 return;
274
275 overwrite_sm_state_stree_stack(&fake_cur_stree_stack, sm);
276 }
277
278
279 typedef void (get_state_hook)(int owner, const char *name, struct symbol *sym);
280 DECLARE_PTR_LIST(fn_list, get_state_hook *);
281 static struct fn_list *get_state_hooks;
282
283 void add_get_state_hook(get_state_hook *fn)
284 {
285 get_state_hook **p = malloc(sizeof(get_state_hook *));
286 *p = fn;
287 add_ptr_list(&get_state_hooks, p);
288 }
289
290 static void call_get_state_hooks(int owner, const char *name, struct symbol *sym)
291 {
292 static int recursion;
293 get_state_hook **fn;
294
295 if (recursion)
296 return;
297 recursion = 1;
298
299 FOR_EACH_PTR(get_state_hooks, fn) {
300 (*fn)(owner, name, sym);
301 } END_FOR_EACH_PTR(fn);
302
303 recursion = 0;
304 }
305
306 struct smatch_state *__get_state(int owner, const char *name, struct symbol *sym)
307 {
308 struct sm_state *sm;
309
310 sm = get_sm_state(owner, name, sym);
311 if (!sm)
312 return NULL;
313 return sm->state;
314 }
315
316 struct smatch_state *get_state(int owner, const char *name, struct symbol *sym)
317 {
318 call_get_state_hooks(owner, name, sym);
319
320 return __get_state(owner, name, sym);
321 }
322
323 struct smatch_state *get_state_expr(int owner, struct expression *expr)
324 {
325 char *name;
326 struct symbol *sym;
327 struct smatch_state *ret = NULL;
328
329 expr = strip_expr(expr);
330 name = expr_to_var_sym(expr, &sym);
331 if (!name || !sym)
332 goto free;
333 ret = get_state(owner, name, sym);
334 free:
335 free_string(name);
336 return ret;
337 }
338
339 struct state_list *get_possible_states(int owner, const char *name, struct symbol *sym)
340 {
341 struct sm_state *sms;
342
343 sms = get_sm_state_stree(cur_stree, owner, name, sym);
344 if (sms)
345 return sms->possible;
346 return NULL;
347 }
348
349 struct state_list *get_possible_states_expr(int owner, struct expression *expr)
350 {
351 char *name;
352 struct symbol *sym;
353 struct state_list *ret = NULL;
354
355 expr = strip_expr(expr);
356 name = expr_to_var_sym(expr, &sym);
357 if (!name || !sym)
358 goto free;
359 ret = get_possible_states(owner, name, sym);
360 free:
361 free_string(name);
362 return ret;
363 }
364
365 struct sm_state *get_sm_state(int owner, const char *name, struct symbol *sym)
366 {
367 struct sm_state *ret;
368
369 ret = get_sm_state_stree(fast_overlay, owner, name, sym);
370 if (ret)
371 return ret;
372
373 return get_sm_state_stree(cur_stree, owner, name, sym);
374 }
375
376 struct sm_state *get_sm_state_expr(int owner, struct expression *expr)
377 {
378 char *name;
379 struct symbol *sym;
380 struct sm_state *ret = NULL;
381
382 expr = strip_expr(expr);
383 name = expr_to_var_sym(expr, &sym);
384 if (!name || !sym)
385 goto free;
386 ret = get_sm_state(owner, name, sym);
387 free:
388 free_string(name);
389 return ret;
390 }
391
392 void delete_state(int owner, const char *name, struct symbol *sym)
393 {
394 delete_state_stree(&cur_stree, owner, name, sym);
395 if (cond_true_stack) {
396 delete_state_stree_stack(&pre_cond_stack, owner, name, sym);
397 delete_state_stree_stack(&cond_true_stack, owner, name, sym);
398 delete_state_stree_stack(&cond_false_stack, owner, name, sym);
399 }
400 }
401
402 void delete_state_expr(int owner, struct expression *expr)
403 {
404 char *name;
405 struct symbol *sym;
406
407 expr = strip_expr(expr);
408 name = expr_to_var_sym(expr, &sym);
409 if (!name || !sym)
410 goto free;
411 delete_state(owner, name, sym);
412 free:
413 free_string(name);
414 }
415
416 static void delete_all_states_stree_sym(struct stree **stree, struct symbol *sym)
417 {
418 struct state_list *slist = NULL;
419 struct sm_state *sm;
420
421 FOR_EACH_SM(*stree, sm) {
422 if (sm->sym == sym)
423 add_ptr_list(&slist, sm);
424 } END_FOR_EACH_SM(sm);
425
426 FOR_EACH_PTR(slist, sm) {
427 delete_state_stree(stree, sm->owner, sm->name, sm->sym);
428 } END_FOR_EACH_PTR(sm);
429
430 free_slist(&slist);
431 }
432
433 static void delete_all_states_stree_stack_sym(struct stree_stack **stack, struct symbol *sym)
434 {
435 struct stree *stree;
436
437 if (!*stack)
438 return;
439
440 stree = pop_stree(stack);
441 delete_all_states_stree_sym(&stree, sym);
442 push_stree(stack, stree);
443 }
444
445 void __delete_all_states_sym(struct symbol *sym)
446 {
447 delete_all_states_stree_sym(&cur_stree, sym);
448
449 delete_all_states_stree_stack_sym(&true_stack, sym);
450 delete_all_states_stree_stack_sym(&true_stack, sym);
451 delete_all_states_stree_stack_sym(&false_stack, sym);
452 delete_all_states_stree_stack_sym(&pre_cond_stack, sym);
453 delete_all_states_stree_stack_sym(&cond_true_stack, sym);
454 delete_all_states_stree_stack_sym(&cond_false_stack, sym);
455 delete_all_states_stree_stack_sym(&fake_cur_stree_stack, sym);
456 delete_all_states_stree_stack_sym(&break_stack, sym);
457 delete_all_states_stree_stack_sym(&fake_break_stack, sym);
458 delete_all_states_stree_stack_sym(&switch_stack, sym);
459 delete_all_states_stree_stack_sym(&continue_stack, sym);
460
461 /*
462 * deleting from the goto stack is problematic because we don't know
463 * if the label is in scope and also we need the value for --two-passes.
464 */
465 }
466
467 struct stree *get_all_states_from_stree(int owner, struct stree *source)
468 {
469 struct stree *ret = NULL;
470 struct sm_state *tmp;
471
472 FOR_EACH_SM(source, tmp) {
473 if (tmp->owner == owner)
474 avl_insert(&ret, tmp);
475 } END_FOR_EACH_SM(tmp);
476
477 return ret;
478 }
479
480 struct stree *get_all_states_stree(int owner)
481 {
482 return get_all_states_from_stree(owner, cur_stree);
483 }
484
485 struct stree *__get_cur_stree(void)
486 {
487 return cur_stree;
488 }
489
490 int is_reachable(void)
491 {
492 if (cur_stree)
493 return 1;
494 return 0;
495 }
496
497 void set_true_false_states(int owner, const char *name, struct symbol *sym,
498 struct smatch_state *true_state,
499 struct smatch_state *false_state)
500 {
501 if (read_only)
502 sm_perror("cur_stree is read only.");
503
504 if (option_debug || strcmp(check_name(owner), option_debug_check) == 0) {
505 struct smatch_state *tmp;
506
507 tmp = __get_state(owner, name, sym);
508 sm_msg("%s [%s] '%s'. Was %s. Now T:%s F:%s", __func__,
509 check_name(owner), name, show_state(tmp),
510 show_state(true_state), show_state(false_state));
511 }
512
513 if (unreachable())
514 return;
515
516 if (!cond_false_stack || !cond_true_stack) {
517 sm_perror("missing true/false stacks");
518 return;
519 }
520
521 if (true_state)
522 set_state_stree_stack(&cond_true_stack, owner, name, sym, true_state);
523 if (false_state)
524 set_state_stree_stack(&cond_false_stack, owner, name, sym, false_state);
525 }
526
527 void set_true_false_states_expr(int owner, struct expression *expr,
528 struct smatch_state *true_state,
529 struct smatch_state *false_state)
530 {
531 char *name;
532 struct symbol *sym;
533
534 expr = strip_expr(expr);
535 name = expr_to_var_sym(expr, &sym);
536 if (!name || !sym)
537 goto free;
538 set_true_false_states(owner, name, sym, true_state, false_state);
539 free:
540 free_string(name);
541 }
542
543 void __set_true_false_sm(struct sm_state *true_sm, struct sm_state *false_sm)
544 {
545 int owner;
546 const char *name;
547 struct symbol *sym;
548
549 if (!true_sm && !false_sm)
550 return;
551
552 if (unreachable())
553 return;
554
555 owner = true_sm ? true_sm->owner : false_sm->owner;
556 name = true_sm ? true_sm->name : false_sm->name;
557 sym = true_sm ? true_sm->sym : false_sm->sym;
558 if (option_debug || strcmp(check_name(owner), option_debug_check) == 0) {
559 struct smatch_state *tmp;
560
561 tmp = __get_state(owner, name, sym);
562 sm_msg("%s [%s] '%s'. Was %s. Now T:%s F:%s", __func__,
563 check_name(owner), name, show_state(tmp),
564 show_state(true_sm ? true_sm->state : NULL),
565 show_state(false_sm ? false_sm->state : NULL));
566 }
567
568 if (!cond_false_stack || !cond_true_stack) {
569 sm_perror("missing true/false stacks");
570 return;
571 }
572
573 if (true_sm)
574 overwrite_sm_state_stree_stack(&cond_true_stack, true_sm);
575 if (false_sm)
576 overwrite_sm_state_stree_stack(&cond_false_stack, false_sm);
577 }
578
579 void nullify_path(void)
580 {
581 if (fake_cur_stree_stack) {
582 __free_fake_cur_stree();
583 __push_fake_cur_stree();
584 }
585 free_stree(&cur_stree);
586 }
587
588 void __match_nullify_path_hook(const char *fn, struct expression *expr,
589 void *unused)
590 {
591 nullify_path();
592 }
593
594 /*
595 * At the start of every function we mark the path
596 * as unnull. That way there is always at least one state
597 * in the cur_stree until nullify_path is called. This
598 * is used in merge_slist() for the first null check.
599 */
600 void __unnullify_path(void)
601 {
602 if (!cur_stree)
603 set_state(-1, "unnull_path", NULL, &true_state);
604 }
605
606 int __path_is_null(void)
607 {
608 if (cur_stree)
609 return 0;
610 return 1;
611 }
612
613 static void check_stree_stack_free(struct stree_stack **stack)
614 {
615 if (*stack) {
616 sm_perror("stack not empty");
617 free_stack_and_strees(stack);
618 }
619 }
620
621 void save_all_states(void)
622 {
623 __add_ptr_list(&backup, cur_stree);
624 cur_stree = NULL;
625
626 __add_ptr_list(&backup, true_stack);
627 true_stack = NULL;
628 __add_ptr_list(&backup, false_stack);
629 false_stack = NULL;
630 __add_ptr_list(&backup, pre_cond_stack);
631 pre_cond_stack = NULL;
632
633 __add_ptr_list(&backup, cond_true_stack);
634 cond_true_stack = NULL;
635 __add_ptr_list(&backup, cond_false_stack);
636 cond_false_stack = NULL;
637
638 __add_ptr_list(&backup, fake_cur_stree_stack);
639 fake_cur_stree_stack = NULL;
640
641 __add_ptr_list(&backup, break_stack);
642 break_stack = NULL;
643 __add_ptr_list(&backup, fake_break_stack);
644 fake_break_stack = NULL;
645
646 __add_ptr_list(&backup, switch_stack);
647 switch_stack = NULL;
648 __add_ptr_list(&backup, remaining_cases);
649 remaining_cases = NULL;
650 __add_ptr_list(&backup, default_stack);
651 default_stack = NULL;
652 __add_ptr_list(&backup, continue_stack);
653 continue_stack = NULL;
654
655 __add_ptr_list(&backup, goto_stack);
656 goto_stack = NULL;
657 }
658
659 static void *pop_backup(void)
660 {
661 void *ret;
662
663 ret = last_ptr_list(backup);
664 delete_ptr_list_last(&backup);
665 return ret;
666 }
667
668 void restore_all_states(void)
669 {
670 goto_stack = pop_backup();
671
672 continue_stack = pop_backup();
673 default_stack = pop_backup();
674 remaining_cases = pop_backup();
675 switch_stack = pop_backup();
676 fake_break_stack = pop_backup();
677 break_stack = pop_backup();
678
679 fake_cur_stree_stack = pop_backup();
680
681 cond_false_stack = pop_backup();
682 cond_true_stack = pop_backup();
683
684 pre_cond_stack = pop_backup();
685 false_stack = pop_backup();
686 true_stack = pop_backup();
687
688 cur_stree = pop_backup();
689 }
690
691 void free_goto_stack(void)
692 {
693 struct named_stree *named_stree;
694
695 FOR_EACH_PTR(goto_stack, named_stree) {
696 free_stree(&named_stree->stree);
697 } END_FOR_EACH_PTR(named_stree);
698 __free_ptr_list((struct ptr_list **)&goto_stack);
699 }
700
701 void clear_all_states(void)
702 {
703 nullify_path();
704 check_stree_stack_free(&true_stack);
705 check_stree_stack_free(&false_stack);
706 check_stree_stack_free(&pre_cond_stack);
707 check_stree_stack_free(&cond_true_stack);
708 check_stree_stack_free(&cond_false_stack);
709 check_stree_stack_free(&break_stack);
710 check_stree_stack_free(&fake_break_stack);
711 check_stree_stack_free(&switch_stack);
712 check_stree_stack_free(&continue_stack);
713 check_stree_stack_free(&fake_cur_stree_stack);
714
715 free_goto_stack();
716
717 free_every_single_sm_state();
718 free_tmp_expressions();
719 }
720
721 void __push_cond_stacks(void)
722 {
723 push_stree(&cond_true_stack, NULL);
724 push_stree(&cond_false_stack, NULL);
725 __push_fake_cur_stree();
726 }
727
728 void __fold_in_set_states(void)
729 {
730 struct stree *new_states;
731 struct sm_state *sm;
732
733 new_states = __pop_fake_cur_stree();
734 FOR_EACH_SM(new_states, sm) {
735 __set_sm(sm);
736 __set_true_false_sm(sm, sm);
737 } END_FOR_EACH_SM(sm);
738 free_stree(&new_states);
739 }
740
741 void __free_set_states(void)
742 {
743 struct stree *new_states;
744
745 new_states = __pop_fake_cur_stree();
746 free_stree(&new_states);
747 }
748
749 struct stree *__copy_cond_true_states(void)
750 {
751 struct stree *ret;
752
753 ret = pop_stree(&cond_true_stack);
754 push_stree(&cond_true_stack, clone_stree(ret));
755 return ret;
756 }
757
758 struct stree *__copy_cond_false_states(void)
759 {
760 struct stree *ret;
761
762 ret = pop_stree(&cond_false_stack);
763 push_stree(&cond_false_stack, clone_stree(ret));
764 return ret;
765 }
766
767 struct stree *__pop_cond_true_stack(void)
768 {
769 return pop_stree(&cond_true_stack);
770 }
771
772 struct stree *__pop_cond_false_stack(void)
773 {
774 return pop_stree(&cond_false_stack);
775 }
776
777 /*
778 * This combines the pre cond states with either the true or false states.
779 * For example:
780 * a = kmalloc() ; if (a !! foo(a)
781 * In the pre state a is possibly null. In the true state it is non null.
782 * In the false state it is null. Combine the pre and the false to get
783 * that when we call 'foo', 'a' is null.
784 */
785 static void __use_cond_stack(struct stree_stack **stack)
786 {
787 struct stree *stree;
788
789 free_stree(&cur_stree);
790
791 cur_stree = pop_stree(&pre_cond_stack);
792 push_stree(&pre_cond_stack, clone_stree(cur_stree));
793
794 stree = pop_stree(stack);
795 overwrite_stree(stree, &cur_stree);
796 push_stree(stack, stree);
797 }
798
799 void __use_pre_cond_states(void)
800 {
801 free_stree(&cur_stree);
802 cur_stree = pop_stree(&pre_cond_stack);
803 }
804
805 void __use_cond_true_states(void)
806 {
807 __use_cond_stack(&cond_true_stack);
808 }
809
810 void __use_cond_false_states(void)
811 {
812 __use_cond_stack(&cond_false_stack);
813 }
814
815 void __negate_cond_stacks(void)
816 {
817 struct stree *old_false, *old_true;
818
819 old_false = pop_stree(&cond_false_stack);
820 old_true = pop_stree(&cond_true_stack);
821 push_stree(&cond_false_stack, old_true);
822 push_stree(&cond_true_stack, old_false);
823 }
824
825 void __and_cond_states(void)
826 {
827 and_stree_stack(&cond_true_stack);
828 or_stree_stack(&pre_cond_stack, cur_stree, &cond_false_stack);
829 }
830
831 void __or_cond_states(void)
832 {
833 or_stree_stack(&pre_cond_stack, cur_stree, &cond_true_stack);
834 and_stree_stack(&cond_false_stack);
835 }
836
837 void __save_pre_cond_states(void)
838 {
839 push_stree(&pre_cond_stack, clone_stree(cur_stree));
840 }
841
842 void __discard_pre_cond_states(void)
843 {
844 struct stree *tmp;
845
846 tmp = pop_stree(&pre_cond_stack);
847 free_stree(&tmp);
848 }
849
850 struct stree *__get_true_states(void)
851 {
852 return clone_stree(top_stree(cond_true_stack));
853 }
854
855 struct stree *__get_false_states(void)
856 {
857 return clone_stree(top_stree(cond_false_stack));
858 }
859
860 void __use_cond_states(void)
861 {
862 struct stree *pre, *pre_clone, *true_states, *false_states;
863
864 pre = pop_stree(&pre_cond_stack);
865 pre_clone = clone_stree(pre);
866
867 true_states = pop_stree(&cond_true_stack);
868 overwrite_stree(true_states, &pre);
869 free_stree(&true_states);
870 /* we use the true states right away */
871 free_stree(&cur_stree);
872 cur_stree = pre;
873
874 false_states = pop_stree(&cond_false_stack);
875 overwrite_stree(false_states, &pre_clone);
876 free_stree(&false_states);
877 push_stree(&false_stack, pre_clone);
878 }
879
880 void __push_true_states(void)
881 {
882 push_stree(&true_stack, clone_stree(cur_stree));
883 }
884
885 void __use_false_states(void)
886 {
887 free_stree(&cur_stree);
888 cur_stree = pop_stree(&false_stack);
889 }
890
891 void __discard_false_states(void)
892 {
893 struct stree *stree;
894
895 stree = pop_stree(&false_stack);
896 free_stree(&stree);
897 }
898
899 void __merge_false_states(void)
900 {
901 struct stree *stree;
902
903 stree = pop_stree(&false_stack);
904 merge_stree(&cur_stree, stree);
905 free_stree(&stree);
906 }
907
908 /*
909 * This function probably seemed common sensical when I wrote it but, oh wow,
910 * does it look subtle in retrospect. Say we set a state on one side of the if
911 * else path but not on the other, then what we should record in the fake stree
912 * is the merged state.
913 *
914 * This function relies on the fact that the we always set the cur_stree as well
915 * and we already have the infrastructure to merge things correctly into the
916 * cur_stree.
917 *
918 * So instead of merging fake strees together which is probably a lot of work,
919 * we just use it as a list of set states and look up the actual current values
920 * in the cur_stree.
921 *
922 */
923 static void update_stree_with_merged(struct stree **stree)
924 {
925 struct state_list *slist = NULL;
926 struct sm_state *sm, *new;
927
928 FOR_EACH_SM(*stree, sm) {
929 new = get_sm_state(sm->owner, sm->name, sm->sym);
930 if (!new) /* This can happen if we go out of scope */
931 continue;
932 add_ptr_list(&slist, new);
933 } END_FOR_EACH_SM(sm);
934
935 FOR_EACH_PTR(slist, sm) {
936 overwrite_sm_state_stree(stree, sm);
937 } END_FOR_EACH_PTR(sm);
938
939 free_slist(&slist);
940 }
941
942 static void update_fake_stree_with_merged(void)
943 {
944 struct stree *stree;
945
946 if (!fake_cur_stree_stack)
947 return;
948 stree = pop_stree(&fake_cur_stree_stack);
949 update_stree_with_merged(&stree);
950 push_stree(&fake_cur_stree_stack, stree);
951 }
952
953 void __merge_true_states(void)
954 {
955 struct stree *stree;
956
957 stree = pop_stree(&true_stack);
958 merge_stree(&cur_stree, stree);
959 update_fake_stree_with_merged();
960 free_stree(&stree);
961 }
962
963 void __push_continues(void)
964 {
965 push_stree(&continue_stack, NULL);
966 }
967
968 void __discard_continues(void)
969 {
970 struct stree *stree;
971
972 stree = pop_stree(&continue_stack);
973 free_stree(&stree);
974 }
975
976 void __process_continues(void)
977 {
978 struct stree *stree;
979
980 stree = pop_stree(&continue_stack);
981 if (!stree)
982 stree = clone_stree(cur_stree);
983 else
984 merge_stree(&stree, cur_stree);
985
986 push_stree(&continue_stack, stree);
987 }
988
989 void __merge_continues(void)
990 {
991 struct stree *stree;
992
993 stree = pop_stree(&continue_stack);
994 merge_stree(&cur_stree, stree);
995 free_stree(&stree);
996 }
997
998 void __push_breaks(void)
999 {
1000 push_stree(&break_stack, NULL);
1001 if (fake_cur_stree_stack)
1002 push_stree(&fake_break_stack, NULL);
1003 }
1004
1005 void __process_breaks(void)
1006 {
1007 struct stree *stree;
1008
1009 stree = pop_stree(&break_stack);
1010 if (!stree)
1011 stree = clone_stree(cur_stree);
1012 else
1013 merge_stree(&stree, cur_stree);
1014 push_stree(&break_stack, stree);
1015
1016 if (!fake_cur_stree_stack)
1017 return;
1018
1019 stree = pop_stree(&fake_break_stack);
1020 if (!stree)
1021 stree = clone_stree(top_stree(fake_cur_stree_stack));
1022 else
1023 merge_stree(&stree, top_stree(fake_cur_stree_stack));
1024 push_stree(&fake_break_stack, stree);
1025 }
1026
1027 int __has_breaks(void)
1028 {
1029 struct stree *stree;
1030 int ret;
1031
1032 stree = pop_stree(&break_stack);
1033 ret = !!stree;
1034 push_stree(&break_stack, stree);
1035 return ret;
1036 }
1037
1038 void __merge_breaks(void)
1039 {
1040 struct stree *stree;
1041 struct sm_state *sm;
1042
1043 stree = pop_stree(&break_stack);
1044 merge_stree(&cur_stree, stree);
1045 free_stree(&stree);
1046
1047 if (!fake_cur_stree_stack)
1048 return;
1049
1050 stree = pop_stree(&fake_break_stack);
1051 update_stree_with_merged(&stree);
1052 FOR_EACH_SM(stree, sm) {
1053 overwrite_sm_state_stree_stack(&fake_cur_stree_stack, sm);
1054 } END_FOR_EACH_SM(sm);
1055 free_stree(&stree);
1056 }
1057
1058 void __use_breaks(void)
1059 {
1060 struct stree *stree;
1061 struct sm_state *sm;
1062
1063 free_stree(&cur_stree);
1064 cur_stree = pop_stree(&break_stack);
1065
1066 if (!fake_cur_stree_stack)
1067 return;
1068 stree = pop_stree(&fake_break_stack);
1069 FOR_EACH_SM(stree, sm) {
1070 overwrite_sm_state_stree_stack(&fake_cur_stree_stack, sm);
1071 } END_FOR_EACH_SM(sm);
1072 free_stree(&stree);
1073
1074
1075 }
1076
1077 void __save_switch_states(struct expression *switch_expr)
1078 {
1079 struct range_list *rl;
1080
1081 get_absolute_rl(switch_expr, &rl);
1082
1083 push_rl(&remaining_cases, rl);
1084 push_stree(&switch_stack, clone_stree(cur_stree));
1085 }
1086
1087 int have_remaining_cases(void)
1088 {
1089 return !!top_rl(remaining_cases);
1090 }
1091
1092 void __merge_switches(struct expression *switch_expr, struct range_list *case_rl)
1093 {
1094 struct stree *stree;
1095 struct stree *implied_stree;
1096
1097 stree = pop_stree(&switch_stack);
1098 implied_stree = __implied_case_stree(switch_expr, case_rl, &remaining_cases, &stree);
1099 merge_stree(&cur_stree, implied_stree);
1100 free_stree(&implied_stree);
1101 push_stree(&switch_stack, stree);
1102 }
1103
1104 void __discard_switches(void)
1105 {
1106 struct stree *stree;
1107
1108 pop_rl(&remaining_cases);
1109 stree = pop_stree(&switch_stack);
1110 free_stree(&stree);
1111 }
1112
1113 void __push_default(void)
1114 {
1115 push_stree(&default_stack, NULL);
1116 }
1117
1118 void __set_default(void)
1119 {
1120 set_state_stree_stack(&default_stack, 0, "has_default", NULL, &true_state);
1121 }
1122
1123 int __pop_default(void)
1124 {
1125 struct stree *stree;
1126
1127 stree = pop_stree(&default_stack);
1128 if (stree) {
1129 free_stree(&stree);
1130 return 1;
1131 }
1132 return 0;
1133 }
1134
1135 static struct named_stree *alloc_named_stree(const char *name, struct symbol *sym, struct stree *stree)
1136 {
1137 struct named_stree *named_stree = __alloc_named_stree(0);
1138
1139 named_stree->name = (char *)name;
1140 named_stree->stree = stree;
1141 named_stree->sym = sym;
1142 return named_stree;
1143 }
1144
1145 void __save_gotos(const char *name, struct symbol *sym)
1146 {
1147 struct stree **stree;
1148 struct stree *clone;
1149
1150 stree = get_named_stree(goto_stack, name, sym);
1151 if (stree) {
1152 merge_stree(stree, cur_stree);
1153 return;
1154 } else {
1155 struct named_stree *named_stree;
1156
1157 clone = clone_stree(cur_stree);
1158 named_stree = alloc_named_stree(name, sym, clone);
1159 add_ptr_list(&goto_stack, named_stree);
1160 }
1161 }
1162
1163 void __merge_gotos(const char *name, struct symbol *sym)
1164 {
1165 struct stree **stree;
1166
1167 stree = get_named_stree(goto_stack, name, sym);
1168 if (stree)
1169 merge_stree(&cur_stree, *stree);
1170 }