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 true_state
= { .name
= "true" };
34 struct smatch_state false_state
= { .name
= "false" };
36 static struct state_list
*cur_slist
; /* current states */
38 static struct state_list_stack
*true_stack
; /* states after a t/f branch */
39 static struct state_list_stack
*false_stack
;
40 static struct state_list_stack
*pre_cond_stack
; /* states before a t/f branch */
42 static struct state_list_stack
*cond_true_stack
; /* states affected by a branch */
43 static struct state_list_stack
*cond_false_stack
;
45 static struct state_list_stack
*break_stack
;
46 static struct state_list_stack
*switch_stack
;
47 static struct state_list_stack
*default_stack
;
48 static struct state_list_stack
*continue_stack
;
49 static struct state_list_stack
*false_only_stack
;
51 static struct slist_stack
*goto_stack
;
53 struct state_list_stack
*implied_pools
;
57 void __print_cur_slist()
59 __print_slist(cur_slist
);
62 void set_state(const char *name
, int owner
, struct symbol
*sym
,
63 struct smatch_state
*state
)
69 struct smatch_state
*s
;
71 s
= get_state(name
, owner
, sym
);
73 printf("%d new state. name='%s' owner=%d: %s\n",
74 get_lineno(), name
, owner
, show_state(state
));
76 printf("%d state change name='%s' owner=%d: %s => %s\n",
77 get_lineno(), name
, owner
, show_state(s
),
80 set_state_slist(&cur_slist
, name
, owner
, sym
, state
);
82 if (cond_true_stack
) {
83 set_state_stack(&cond_true_stack
, name
, owner
, sym
, state
);
84 set_state_stack(&cond_false_stack
, name
, owner
, sym
, state
);
88 struct smatch_state
*get_state(const char *name
, int owner
, struct symbol
*sym
)
90 return get_state_slist(cur_slist
, name
, owner
, sym
);
93 struct state_list
*get_possible_states(const char *name
, int owner
,
98 sms
= get_sm_state_slist(cur_slist
, name
, owner
, sym
);
100 return sms
->possible
;
104 void __overwrite_cur_slist(struct state_list
*slist
)
106 overwrite_slist(slist
, &cur_slist
);
109 struct sm_state
*__get_sm_state(const char *name
, int owner
, struct symbol
*sym
)
111 return get_sm_state_slist(cur_slist
, name
, owner
, sym
);
114 void delete_state(const char *name
, int owner
, struct symbol
*sym
)
116 delete_state_slist(&cur_slist
, name
, owner
, sym
);
119 struct state_list
*get_all_states(int owner
)
121 struct state_list
*slist
= NULL
;
122 struct sm_state
*tmp
;
124 FOR_EACH_PTR(cur_slist
, tmp
) {
125 if (tmp
->owner
== owner
) {
126 add_ptr_list(&slist
, tmp
);
128 } END_FOR_EACH_PTR(tmp
);
133 void set_true_false_states(const char *name
, int owner
, struct symbol
*sym
,
134 struct smatch_state
*true_state
,
135 struct smatch_state
*false_state
)
137 /* fixme. save history */
140 struct smatch_state
*tmp
;
142 tmp
= get_state(name
, owner
, sym
);
143 SM_DEBUG("%d set_true_false '%s'. Was %s. Now T:%s F:%s\n",
144 get_lineno(), name
, show_state(tmp
),
145 show_state(true_state
), show_state(false_state
));
148 if (!cond_false_stack
|| !cond_true_stack
) {
149 printf("Error: missing true/false stacks\n");
154 set_state_slist(&cur_slist
, name
, owner
, sym
, true_state
);
155 set_state_stack(&cond_true_stack
, name
, owner
, sym
, true_state
);
158 set_state_stack(&cond_false_stack
, name
, owner
, sym
, false_state
);
163 del_slist(&cur_slist
);
167 * At the start of every function we mark the path
168 * as unnull. That there is always at least one state
169 * in the cur_slist until nullify_path is called. This
170 * is used in merge_slist() for the first null check.
173 void __unnullify_path()
175 set_state("unnull_path", 0, NULL
, &true_state
);
178 void clear_all_states()
180 struct named_slist
*named_slist
;
183 del_slist_stack(&true_stack
);
184 del_slist_stack(&false_stack
);
185 del_slist_stack(&false_only_stack
);
186 del_slist_stack(&pre_cond_stack
);
187 del_slist_stack(&cond_true_stack
);
188 del_slist_stack(&cond_false_stack
);
189 del_slist_stack(&break_stack
);
190 del_slist_stack(&switch_stack
);
191 del_slist_stack(&continue_stack
);
192 del_slist_stack(&implied_pools
);
194 FOR_EACH_PTR(goto_stack
, named_slist
) {
195 del_slist(&named_slist
->slist
);
196 } END_FOR_EACH_PTR(named_slist
);
197 __free_ptr_list((struct ptr_list
**)&goto_stack
);
201 void __push_cond_stacks()
203 push_slist(&cond_true_stack
, NULL
);
204 push_slist(&cond_false_stack
, NULL
);
208 * This combines the pre cond states with either the true or false states.
210 * a = kmalloc() ; if (a !! foo(a)
211 * In the pre state a is possibly null. In the true state it is non null.
212 * In the false state it is null. Combine the pre and the false to get
213 * that when we call 'foo', 'a' is null.
216 static void __use_cond_stack(struct state_list_stack
**stack
)
218 struct state_list
*slist
;
220 del_slist(&cur_slist
);
222 cur_slist
= pop_slist(&pre_cond_stack
);
223 push_slist(&pre_cond_stack
, clone_slist(cur_slist
));
225 slist
= pop_slist(stack
);
226 overwrite_slist(slist
, &cur_slist
);
227 push_slist(stack
, slist
);
231 void __use_cond_true_states()
233 __use_cond_stack(&cond_true_stack
);
236 void __use_cond_false_states()
238 __use_cond_stack(&cond_false_stack
);
241 void __negate_cond_stacks()
243 struct state_list
*old_false
, *old_true
;
245 old_false
= pop_slist(&cond_false_stack
);
246 old_true
= pop_slist(&cond_true_stack
);
248 overwrite_slist(old_false
, &cur_slist
);
250 push_slist(&cond_false_stack
, old_true
);
251 push_slist(&cond_true_stack
, old_false
);
254 void __and_cond_states()
256 and_slist_stack(&cond_true_stack
);
257 or_slist_stack(&cond_false_stack
);
260 void __or_cond_states()
262 or_slist_stack(&cond_true_stack
);
263 and_slist_stack(&cond_false_stack
);
266 void __save_pre_cond_states()
268 push_slist(&pre_cond_stack
, clone_slist(cur_slist
));
271 void __pop_pre_cond_states()
273 struct state_list
*tmp
;
275 tmp
= pop_slist(&pre_cond_stack
);
279 void __use_false_only_stack()
281 struct state_list
*slist
;
283 slist
= pop_slist(&false_only_stack
);
284 overwrite_slist(slist
, &cur_slist
);
288 void __pop_false_only_stack()
290 struct state_list
*slist
;
292 slist
= pop_slist(&false_only_stack
);
296 void __use_cond_states()
298 struct state_list
*pre
, *pre_clone
, *true_states
, *false_states
;
300 pre
= pop_slist(&pre_cond_stack
);
301 pre_clone
= clone_slist(pre
);
303 true_states
= pop_slist(&cond_true_stack
);
304 overwrite_slist(true_states
, &pre
);
305 /* we use the true states right away */
306 del_slist(&cur_slist
);
310 false_states
= pop_slist(&cond_false_stack
);
311 push_slist(&false_only_stack
, clone_slist(false_states
));
312 overwrite_slist(false_states
, &pre_clone
);
313 push_slist(&false_stack
, pre_clone
);
316 void __push_true_states()
318 push_slist(&true_stack
, clone_slist(cur_slist
));
321 void __use_false_states()
323 del_slist(&cur_slist
);
324 cur_slist
= pop_slist(&false_stack
);
327 void __pop_false_states()
329 struct state_list
*slist
;
331 slist
= pop_slist(&false_stack
);
335 void __merge_false_states()
337 struct state_list
*slist
;
339 slist
= pop_slist(&false_stack
);
340 merge_slist(&cur_slist
, slist
);
344 void __merge_true_states()
346 struct state_list
*slist
;
348 slist
= pop_slist(&true_stack
);
349 merge_slist(&cur_slist
, slist
);
353 void __push_continues()
355 push_slist(&continue_stack
, NULL
);
358 void __pop_continues()
360 struct state_list
*slist
;
362 slist
= pop_slist(&continue_stack
);
366 void __process_continues()
368 struct state_list
*slist
;
370 slist
= pop_slist(&continue_stack
);
372 overwrite_slist(cur_slist
, &slist
);
374 merge_slist(&slist
, cur_slist
);
376 push_slist(&continue_stack
, slist
);
379 void __merge_continues()
381 struct state_list
*slist
;
383 slist
= pop_slist(&continue_stack
);
384 merge_slist(&cur_slist
, slist
);
390 push_slist(&break_stack
, NULL
);
393 void __process_breaks()
395 struct state_list
*slist
;
397 slist
= pop_slist(&break_stack
);
399 overwrite_slist(cur_slist
, &slist
);
401 merge_slist(&slist
, cur_slist
);
403 push_slist(&break_stack
, slist
);
406 void __merge_breaks()
408 struct state_list
*slist
;
410 slist
= pop_slist(&break_stack
);
411 merge_slist(&cur_slist
, slist
);
417 del_slist(&cur_slist
);
418 cur_slist
= pop_slist(&break_stack
);
421 void __save_switch_states()
423 push_slist(&switch_stack
, clone_slist(cur_slist
));
426 void __merge_switches()
428 struct state_list
*slist
;
430 slist
= pop_slist(&switch_stack
);
431 merge_slist(&cur_slist
, slist
);
432 push_slist(&switch_stack
, slist
);
435 void __pop_switches()
437 struct state_list
*slist
;
439 slist
= pop_slist(&switch_stack
);
443 void __push_default()
445 push_slist(&default_stack
, NULL
);
450 set_state_stack(&default_stack
, "has_default", 0, NULL
, &true_state
);
455 struct state_list
*slist
;
457 slist
= pop_slist(&default_stack
);
465 static struct named_slist
*alloc_named_slist(const char *name
,
466 struct state_list
*slist
)
468 struct named_slist
*named_slist
= __alloc_named_slist(0);
470 named_slist
->name
= (char *)name
;
471 named_slist
->slist
= slist
;
475 void __save_gotos(const char *name
)
477 struct state_list
**slist
;
479 slist
= get_slist_from_slist_stack(goto_stack
, name
);
481 merge_slist(slist
, cur_slist
);
484 struct state_list
*slist
;
485 struct named_slist
*named_slist
;
487 slist
= clone_slist(cur_slist
);
488 named_slist
= alloc_named_slist(name
, slist
);
489 add_ptr_list(&goto_stack
, named_slist
);
493 void __merge_gotos(const char *name
)
495 struct state_list
**slist
;
497 slist
= get_slist_from_slist_stack(goto_stack
, name
);
499 merge_slist(&cur_slist
, *slist
);