2 * sparse/smatch_states.c
4 * Copyright (C) 2006 Dan Carpenter.
6 * Licensed under the Open Software License version 1.1
11 * You have a lists of states. kernel = locked, foo = NULL, ...
12 * When you hit an if {} else {} statement then you swap the list
13 * of states for a different list of states. The lists are stored
16 * At the beginning of this file there are list of the stacks that
17 * we use. Each function in this file does something to one of
20 * So the smatch_flow.c understands code but it doesn't understand states.
21 * smatch_flow calls functions in this file. This file calls functions
22 * in smatch_slist.c which just has boring generic plumbing for handling
23 * state lists. But really it's this file where all the magic happens.
30 #include "smatch_slist.h"
32 struct smatch_state undefined
= { .name
= "undefined" };
33 struct smatch_state merged
= { .name
= "merged" };
34 struct smatch_state true_state
= { .name
= "true" };
35 struct smatch_state false_state
= { .name
= "false" };
37 static struct state_list
*cur_slist
; /* current states */
39 static struct state_list_stack
*true_stack
; /* states after a t/f branch */
40 static struct state_list_stack
*false_stack
;
41 static struct state_list_stack
*pre_cond_stack
; /* states before a t/f branch */
43 static struct state_list_stack
*cond_true_stack
; /* states affected by a branch */
44 static struct state_list_stack
*cond_false_stack
;
46 static struct state_list_stack
*break_stack
;
47 static struct state_list_stack
*switch_stack
;
48 static struct state_list_stack
*default_stack
;
49 static struct state_list_stack
*continue_stack
;
50 static struct state_list_stack
*false_only_stack
;
52 static struct named_stack
*goto_stack
;
54 struct state_list_stack
*implied_pools
;
58 void __print_cur_slist()
60 __print_slist(cur_slist
);
63 static int unreachable()
65 static int reset_warnings
= 1;
72 if (reset_warnings
|| debug_states
)
73 smatch_msg("ignoring unreachable code.");
78 void set_state(const char *name
, int owner
, struct symbol
*sym
,
79 struct smatch_state
*state
)
85 struct smatch_state
*s
;
87 s
= get_state(name
, owner
, sym
);
89 printf("%d new state. name='%s' owner=%d: %s\n",
90 get_lineno(), name
, owner
, show_state(state
));
92 printf("%d state change name='%s' owner=%d: %s => %s\n",
93 get_lineno(), name
, owner
, show_state(s
),
97 if (owner
!= -1 && unreachable())
100 set_state_slist(&cur_slist
, name
, owner
, sym
, state
);
102 if (cond_true_stack
) {
103 set_state_stack(&cond_true_stack
, name
, owner
, sym
, state
);
104 set_state_stack(&cond_false_stack
, name
, owner
, sym
, state
);
108 struct smatch_state
*get_state(const char *name
, int owner
, struct symbol
*sym
)
110 return get_state_slist(cur_slist
, name
, owner
, sym
);
113 struct state_list
*get_possible_states(const char *name
, int owner
,
116 struct sm_state
*sms
;
118 sms
= get_sm_state_slist(cur_slist
, name
, owner
, sym
);
120 return sms
->possible
;
124 struct sm_state
*get_sm_state(const char *name
, int owner
, struct symbol
*sym
)
126 return get_sm_state_slist(cur_slist
, name
, owner
, sym
);
129 void delete_state(const char *name
, int owner
, struct symbol
*sym
)
131 delete_state_slist(&cur_slist
, name
, owner
, sym
);
134 struct state_list
*get_all_states(int owner
)
136 struct state_list
*slist
= NULL
;
137 struct sm_state
*tmp
;
139 FOR_EACH_PTR(cur_slist
, tmp
) {
140 if (tmp
->owner
== owner
) {
141 add_ptr_list(&slist
, tmp
);
143 } END_FOR_EACH_PTR(tmp
);
148 struct state_list
*__get_cur_slist()
153 void set_true_false_states(const char *name
, int owner
, struct symbol
*sym
,
154 struct smatch_state
*true_state
,
155 struct smatch_state
*false_state
)
158 struct smatch_state
*tmp
;
160 tmp
= get_state(name
, owner
, sym
);
161 SM_DEBUG("%d set_true_false '%s'. Was %s. Now T:%s F:%s\n",
162 get_lineno(), name
, show_state(tmp
),
163 show_state(true_state
), show_state(false_state
));
169 if (!cond_false_stack
|| !cond_true_stack
) {
170 printf("Error: missing true/false stacks\n");
175 set_state_slist(&cur_slist
, name
, owner
, sym
, true_state
);
176 set_state_stack(&cond_true_stack
, name
, owner
, sym
, true_state
);
179 set_state_stack(&cond_false_stack
, name
, owner
, sym
, false_state
);
182 void __set_true_false_sm(struct sm_state
*true_state
,
183 struct sm_state
*false_state
)
188 if (!cond_false_stack
|| !cond_true_stack
) {
189 printf("Error: missing true/false stacks\n");
194 overwrite_sm_state(&cur_slist
, true_state
);
195 overwrite_sm_state_stack(&cond_true_stack
, true_state
);
198 overwrite_sm_state_stack(&cond_false_stack
, false_state
);
203 free_slist(&cur_slist
);
207 * At the start of every function we mark the path
208 * as unnull. That there is always at least one state
209 * in the cur_slist until nullify_path is called. This
210 * is used in merge_slist() for the first null check.
213 void __unnullify_path()
215 set_state("unnull_path", -1, NULL
, &true_state
);
225 void clear_all_states()
227 struct named_slist
*named_slist
;
230 free_stack_and_slists(&true_stack
);
231 free_stack_and_slists(&false_stack
);
232 free_stack_and_slists(&false_only_stack
);
233 free_stack_and_slists(&pre_cond_stack
);
234 free_stack_and_slists(&cond_true_stack
);
235 free_stack_and_slists(&cond_false_stack
);
236 free_stack_and_slists(&break_stack
);
237 free_stack_and_slists(&switch_stack
);
238 free_stack_and_slists(&continue_stack
);
239 free_stack_and_slists(&implied_pools
);
241 FOR_EACH_PTR(goto_stack
, named_slist
) {
242 free_slist(&named_slist
->slist
);
243 } END_FOR_EACH_PTR(named_slist
);
244 __free_ptr_list((struct ptr_list
**)&goto_stack
);
245 free_every_single_sm_state();
249 void __push_cond_stacks()
251 push_slist(&cond_true_stack
, NULL
);
252 push_slist(&cond_false_stack
, NULL
);
256 * This combines the pre cond states with either the true or false states.
258 * a = kmalloc() ; if (a !! foo(a)
259 * In the pre state a is possibly null. In the true state it is non null.
260 * In the false state it is null. Combine the pre and the false to get
261 * that when we call 'foo', 'a' is null.
264 static void __use_cond_stack(struct state_list_stack
**stack
)
266 struct state_list
*slist
;
268 free_slist(&cur_slist
);
270 cur_slist
= pop_slist(&pre_cond_stack
);
271 push_slist(&pre_cond_stack
, clone_slist(cur_slist
));
273 slist
= pop_slist(stack
);
274 overwrite_slist(slist
, &cur_slist
);
275 push_slist(stack
, slist
);
278 void __save_false_states_for_later()
280 struct state_list
*pre_conditions
;
281 struct state_list
*false_states
;
282 struct state_list
*tmp
;
284 pre_conditions
= pop_slist(&pre_cond_stack
);
285 false_states
= pop_slist(&cond_false_stack
);
286 tmp
= clone_slist(pre_conditions
);
288 overwrite_slist(false_states
, &tmp
);
290 push_slist(&pre_cond_stack
, tmp
);
291 push_slist(&pre_cond_stack
, pre_conditions
);
292 push_slist(&cond_false_stack
, false_states
);
295 void __use_previously_stored_false_states()
297 free_slist(&cur_slist
);
298 cur_slist
= pop_slist(&pre_cond_stack
);
301 void __use_cond_true_states()
303 __use_cond_stack(&cond_true_stack
);
306 void __use_cond_false_states()
308 __use_cond_stack(&cond_false_stack
);
311 void __negate_cond_stacks()
313 struct state_list
*old_false
, *old_true
;
315 old_false
= pop_slist(&cond_false_stack
);
316 old_true
= pop_slist(&cond_true_stack
);
318 overwrite_slist(old_false
, &cur_slist
);
320 push_slist(&cond_false_stack
, old_true
);
321 push_slist(&cond_true_stack
, old_false
);
324 void __and_cond_states()
326 and_slist_stack(&cond_true_stack
);
327 or_slist_stack(&cond_false_stack
);
330 void __or_cond_states()
332 or_slist_stack(&cond_true_stack
);
333 and_slist_stack(&cond_false_stack
);
336 void __save_pre_cond_states()
338 push_slist(&pre_cond_stack
, clone_slist(cur_slist
));
341 void __pop_pre_cond_states()
343 struct state_list
*tmp
;
345 tmp
= pop_slist(&pre_cond_stack
);
349 void __use_false_only_stack()
351 struct state_list
*slist
;
353 slist
= pop_slist(&false_only_stack
);
354 overwrite_slist(slist
, &cur_slist
);
358 void __pop_false_only_stack()
360 struct state_list
*slist
;
362 slist
= pop_slist(&false_only_stack
);
366 void __use_cond_states()
368 struct state_list
*pre
, *pre_clone
, *true_states
, *false_states
;
370 pre
= pop_slist(&pre_cond_stack
);
371 pre_clone
= clone_slist(pre
);
373 true_states
= pop_slist(&cond_true_stack
);
374 overwrite_slist(true_states
, &pre
);
375 /* we use the true states right away */
376 free_slist(&cur_slist
);
380 false_states
= pop_slist(&cond_false_stack
);
381 push_slist(&false_only_stack
, clone_slist(false_states
));
382 overwrite_slist(false_states
, &pre_clone
);
383 push_slist(&false_stack
, pre_clone
);
386 void __push_true_states()
388 push_slist(&true_stack
, clone_slist(cur_slist
));
391 void __use_false_states()
393 free_slist(&cur_slist
);
394 cur_slist
= pop_slist(&false_stack
);
397 void __pop_false_states()
399 struct state_list
*slist
;
401 slist
= pop_slist(&false_stack
);
405 void __merge_false_states()
407 struct state_list
*slist
;
409 slist
= pop_slist(&false_stack
);
410 merge_slist(&cur_slist
, slist
);
414 void __merge_true_states()
416 struct state_list
*slist
;
418 slist
= pop_slist(&true_stack
);
419 merge_slist(&cur_slist
, slist
);
423 void __push_continues()
425 push_slist(&continue_stack
, NULL
);
428 void __pop_continues()
430 struct state_list
*slist
;
432 slist
= pop_slist(&continue_stack
);
436 void __process_continues()
438 struct state_list
*slist
;
440 slist
= pop_slist(&continue_stack
);
442 slist
= clone_slist(cur_slist
);
444 merge_slist(&slist
, cur_slist
);
446 push_slist(&continue_stack
, slist
);
449 void __merge_continues()
451 struct state_list
*slist
;
453 slist
= pop_slist(&continue_stack
);
454 merge_slist(&cur_slist
, slist
);
460 push_slist(&break_stack
, NULL
);
463 void __process_breaks()
465 struct state_list
*slist
;
467 slist
= pop_slist(&break_stack
);
469 slist
= clone_slist(cur_slist
);
471 merge_slist(&slist
, cur_slist
);
473 push_slist(&break_stack
, slist
);
476 void __merge_breaks()
478 struct state_list
*slist
;
480 slist
= pop_slist(&break_stack
);
481 merge_slist(&cur_slist
, slist
);
487 free_slist(&cur_slist
);
488 cur_slist
= pop_slist(&break_stack
);
491 void __save_switch_states()
493 push_slist(&switch_stack
, clone_slist(cur_slist
));
496 void __merge_switches()
498 struct state_list
*slist
;
500 slist
= pop_slist(&switch_stack
);
501 merge_slist(&cur_slist
, slist
);
502 push_slist(&switch_stack
, slist
);
505 void __pop_switches()
507 struct state_list
*slist
;
509 slist
= pop_slist(&switch_stack
);
513 void __push_default()
515 push_slist(&default_stack
, NULL
);
520 set_state_stack(&default_stack
, "has_default", 0, NULL
, &true_state
);
525 struct state_list
*slist
;
527 slist
= pop_slist(&default_stack
);
535 static struct named_slist
*alloc_named_slist(const char *name
,
536 struct state_list
*slist
)
538 struct named_slist
*named_slist
= __alloc_named_slist(0);
540 named_slist
->name
= (char *)name
;
541 named_slist
->slist
= slist
;
545 void __save_gotos(const char *name
)
547 struct state_list
**slist
;
549 slist
= get_slist_from_named_stack(goto_stack
, name
);
551 merge_slist(slist
, cur_slist
);
554 struct state_list
*slist
;
555 struct named_slist
*named_slist
;
557 slist
= clone_slist(cur_slist
);
558 named_slist
= alloc_named_slist(name
, slist
);
559 add_ptr_list(&goto_stack
, named_slist
);
563 void __merge_gotos(const char *name
)
565 struct state_list
**slist
;
567 slist
= get_slist_from_named_stack(goto_stack
, name
);
569 merge_slist(&cur_slist
, *slist
);