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 void set_state(const char *name
, int owner
, struct symbol
*sym
,
64 struct smatch_state
*state
)
70 struct smatch_state
*s
;
72 s
= get_state(name
, owner
, sym
);
74 printf("%d new state. name='%s' owner=%d: %s\n",
75 get_lineno(), name
, owner
, show_state(state
));
77 printf("%d state change name='%s' owner=%d: %s => %s\n",
78 get_lineno(), name
, owner
, show_state(s
),
81 set_state_slist(&cur_slist
, name
, owner
, sym
, state
);
83 if (cond_true_stack
) {
84 set_state_stack(&cond_true_stack
, name
, owner
, sym
, state
);
85 set_state_stack(&cond_false_stack
, name
, owner
, sym
, state
);
89 struct smatch_state
*get_state(const char *name
, int owner
, struct symbol
*sym
)
91 return get_state_slist(cur_slist
, name
, owner
, sym
);
94 struct state_list
*get_possible_states(const char *name
, int owner
,
99 sms
= get_sm_state_slist(cur_slist
, name
, owner
, sym
);
101 return sms
->possible
;
105 struct sm_state
*__get_sm_state(const char *name
, int owner
, struct symbol
*sym
)
107 return get_sm_state_slist(cur_slist
, name
, owner
, sym
);
110 void delete_state(const char *name
, int owner
, struct symbol
*sym
)
112 delete_state_slist(&cur_slist
, name
, owner
, sym
);
115 struct state_list
*get_all_states(int owner
)
117 struct state_list
*slist
= NULL
;
118 struct sm_state
*tmp
;
120 FOR_EACH_PTR(cur_slist
, tmp
) {
121 if (tmp
->owner
== owner
) {
122 add_ptr_list(&slist
, tmp
);
124 } END_FOR_EACH_PTR(tmp
);
129 struct state_list
*__get_cur_slist()
134 void set_true_false_states(const char *name
, int owner
, struct symbol
*sym
,
135 struct smatch_state
*true_state
,
136 struct smatch_state
*false_state
)
138 /* fixme. save history */
141 struct smatch_state
*tmp
;
143 tmp
= get_state(name
, owner
, sym
);
144 SM_DEBUG("%d set_true_false '%s'. Was %s. Now T:%s F:%s\n",
145 get_lineno(), name
, show_state(tmp
),
146 show_state(true_state
), show_state(false_state
));
149 if (!cond_false_stack
|| !cond_true_stack
) {
150 printf("Error: missing true/false stacks\n");
155 set_state_slist(&cur_slist
, name
, owner
, sym
, true_state
);
156 set_state_stack(&cond_true_stack
, name
, owner
, sym
, true_state
);
159 set_state_stack(&cond_false_stack
, name
, owner
, sym
, false_state
);
164 del_slist(&cur_slist
);
168 * At the start of every function we mark the path
169 * as unnull. That there is always at least one state
170 * in the cur_slist until nullify_path is called. This
171 * is used in merge_slist() for the first null check.
174 void __unnullify_path()
176 set_state("unnull_path", 0, NULL
, &true_state
);
186 void clear_all_states()
188 struct named_slist
*named_slist
;
191 del_slist_stack(&true_stack
);
192 del_slist_stack(&false_stack
);
193 del_slist_stack(&false_only_stack
);
194 del_slist_stack(&pre_cond_stack
);
195 del_slist_stack(&cond_true_stack
);
196 del_slist_stack(&cond_false_stack
);
197 del_slist_stack(&break_stack
);
198 del_slist_stack(&switch_stack
);
199 del_slist_stack(&continue_stack
);
200 del_slist_stack(&implied_pools
);
202 FOR_EACH_PTR(goto_stack
, named_slist
) {
203 del_slist(&named_slist
->slist
);
204 } END_FOR_EACH_PTR(named_slist
);
205 __free_ptr_list((struct ptr_list
**)&goto_stack
);
209 void __push_cond_stacks()
211 push_slist(&cond_true_stack
, NULL
);
212 push_slist(&cond_false_stack
, NULL
);
216 * This combines the pre cond states with either the true or false states.
218 * a = kmalloc() ; if (a !! foo(a)
219 * In the pre state a is possibly null. In the true state it is non null.
220 * In the false state it is null. Combine the pre and the false to get
221 * that when we call 'foo', 'a' is null.
224 static void __use_cond_stack(struct state_list_stack
**stack
)
226 struct state_list
*slist
;
228 del_slist(&cur_slist
);
230 cur_slist
= pop_slist(&pre_cond_stack
);
231 push_slist(&pre_cond_stack
, clone_slist(cur_slist
));
233 slist
= pop_slist(stack
);
234 overwrite_slist(slist
, &cur_slist
);
235 push_slist(stack
, slist
);
239 void __use_cond_true_states()
241 __use_cond_stack(&cond_true_stack
);
244 void __use_cond_false_states()
246 __use_cond_stack(&cond_false_stack
);
249 void __negate_cond_stacks()
251 struct state_list
*old_false
, *old_true
;
253 old_false
= pop_slist(&cond_false_stack
);
254 old_true
= pop_slist(&cond_true_stack
);
256 overwrite_slist(old_false
, &cur_slist
);
258 push_slist(&cond_false_stack
, old_true
);
259 push_slist(&cond_true_stack
, old_false
);
262 void __and_cond_states()
264 and_slist_stack(&cond_true_stack
);
265 or_slist_stack(&cond_false_stack
);
268 void __or_cond_states()
270 or_slist_stack(&cond_true_stack
);
271 and_slist_stack(&cond_false_stack
);
274 void __save_pre_cond_states()
276 push_slist(&pre_cond_stack
, clone_slist(cur_slist
));
279 void __pop_pre_cond_states()
281 struct state_list
*tmp
;
283 tmp
= pop_slist(&pre_cond_stack
);
287 void __use_false_only_stack()
289 struct state_list
*slist
;
291 slist
= pop_slist(&false_only_stack
);
292 overwrite_slist(slist
, &cur_slist
);
296 void __pop_false_only_stack()
298 struct state_list
*slist
;
300 slist
= pop_slist(&false_only_stack
);
304 void __use_cond_states()
306 struct state_list
*pre
, *pre_clone
, *true_states
, *false_states
;
308 pre
= pop_slist(&pre_cond_stack
);
309 pre_clone
= clone_slist(pre
);
311 true_states
= pop_slist(&cond_true_stack
);
312 overwrite_slist(true_states
, &pre
);
313 /* we use the true states right away */
314 del_slist(&cur_slist
);
318 false_states
= pop_slist(&cond_false_stack
);
319 push_slist(&false_only_stack
, clone_slist(false_states
));
320 overwrite_slist(false_states
, &pre_clone
);
321 push_slist(&false_stack
, pre_clone
);
324 void __push_true_states()
326 push_slist(&true_stack
, clone_slist(cur_slist
));
329 void __use_false_states()
331 del_slist(&cur_slist
);
332 cur_slist
= pop_slist(&false_stack
);
335 void __pop_false_states()
337 struct state_list
*slist
;
339 slist
= pop_slist(&false_stack
);
343 void __merge_false_states()
345 struct state_list
*slist
;
347 slist
= pop_slist(&false_stack
);
348 merge_slist(&cur_slist
, slist
);
352 void __merge_true_states()
354 struct state_list
*slist
;
356 slist
= pop_slist(&true_stack
);
357 merge_slist(&cur_slist
, slist
);
361 void __push_continues()
363 push_slist(&continue_stack
, NULL
);
366 void __pop_continues()
368 struct state_list
*slist
;
370 slist
= pop_slist(&continue_stack
);
374 void __process_continues()
376 struct state_list
*slist
;
378 slist
= pop_slist(&continue_stack
);
380 overwrite_slist(cur_slist
, &slist
);
382 merge_slist(&slist
, cur_slist
);
384 push_slist(&continue_stack
, slist
);
387 void __merge_continues()
389 struct state_list
*slist
;
391 slist
= pop_slist(&continue_stack
);
392 merge_slist(&cur_slist
, slist
);
398 push_slist(&break_stack
, NULL
);
401 void __process_breaks()
403 struct state_list
*slist
;
405 slist
= pop_slist(&break_stack
);
407 overwrite_slist(cur_slist
, &slist
);
409 merge_slist(&slist
, cur_slist
);
411 push_slist(&break_stack
, slist
);
414 void __merge_breaks()
416 struct state_list
*slist
;
418 slist
= pop_slist(&break_stack
);
419 merge_slist(&cur_slist
, slist
);
425 del_slist(&cur_slist
);
426 cur_slist
= pop_slist(&break_stack
);
429 void __save_switch_states()
431 push_slist(&switch_stack
, clone_slist(cur_slist
));
434 void __merge_switches()
436 struct state_list
*slist
;
438 slist
= pop_slist(&switch_stack
);
439 merge_slist(&cur_slist
, slist
);
440 push_slist(&switch_stack
, slist
);
443 void __pop_switches()
445 struct state_list
*slist
;
447 slist
= pop_slist(&switch_stack
);
451 void __push_default()
453 push_slist(&default_stack
, NULL
);
458 set_state_stack(&default_stack
, "has_default", 0, NULL
, &true_state
);
463 struct state_list
*slist
;
465 slist
= pop_slist(&default_stack
);
473 static struct named_slist
*alloc_named_slist(const char *name
,
474 struct state_list
*slist
)
476 struct named_slist
*named_slist
= __alloc_named_slist(0);
478 named_slist
->name
= (char *)name
;
479 named_slist
->slist
= slist
;
483 void __save_gotos(const char *name
)
485 struct state_list
**slist
;
487 slist
= get_slist_from_named_stack(goto_stack
, name
);
489 merge_slist(slist
, cur_slist
);
492 struct state_list
*slist
;
493 struct named_slist
*named_slist
;
495 slist
= clone_slist(cur_slist
);
496 named_slist
= alloc_named_slist(name
, slist
);
497 add_ptr_list(&goto_stack
, named_slist
);
501 void __merge_gotos(const char *name
)
503 struct state_list
**slist
;
505 slist
= get_slist_from_named_stack(goto_stack
, name
);
507 merge_slist(&cur_slist
, *slist
);