1 /*
2 * Copyright (C) 2010 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_dinfo.c has helper functions for handling data_info structs
20 *
21 */
22
23 #include <stdlib.h>
24 #ifndef __USE_ISOC99
25 #define __USE_ISOC99
26 #endif
27 #include <limits.h>
28 #include "parse.h"
29 #include "smatch.h"
30 #include "smatch_slist.h"
31 #include "smatch_extra.h"
32
33 struct smatch_state *merge_estates(struct smatch_state *s1, struct smatch_state *s2)
34 {
35 struct smatch_state *tmp;
36 struct range_list *value_ranges;
37 struct related_list *rlist;
38
39 if (estates_equiv(s1, s2))
40 return s1;
41
42 value_ranges = rl_union(estate_rl(s1), estate_rl(s2));
43 tmp = alloc_estate_rl(value_ranges);
44 rlist = get_shared_relations(estate_related(s1), estate_related(s2));
45 set_related(tmp, rlist);
46
47 if ((estate_has_hard_max(s1) && (!estate_rl(s2) || estate_has_hard_max(s2))) ||
48 (estate_has_hard_max(s2) && (!estate_rl(s1) || estate_has_hard_max(s1))))
49 estate_set_hard_max(tmp);
50
51 estate_set_fuzzy_max(tmp, sval_max(estate_get_fuzzy_max(s1), estate_get_fuzzy_max(s2)));
52
53 if (estate_capped(s1) && estate_capped(s2))
54 estate_set_capped(tmp);
55
56 if (estate_treat_untagged(s1) && estate_treat_untagged(s2))
57 estate_set_treat_untagged(tmp);
58
59 return tmp;
60 }
61
62 struct data_info *get_dinfo(struct smatch_state *state)
63 {
64 if (!state)
65 return NULL;
66 return (struct data_info *)state->data;
67 }
68
69 struct range_list *estate_rl(struct smatch_state *state)
70 {
71 if (!state)
72 return NULL;
73 return get_dinfo(state)->value_ranges;
74 }
75
76 struct related_list *estate_related(struct smatch_state *state)
77 {
78 if (!state)
79 return NULL;
80 return get_dinfo(state)->related;
81 }
82
83 sval_t estate_get_fuzzy_max(struct smatch_state *state)
84 {
85 sval_t empty = {};
86
87 if (!state || !get_dinfo(state))
88 return empty;
89 return get_dinfo(state)->fuzzy_max;
90 }
91
92 int estate_has_fuzzy_max(struct smatch_state *state)
93 {
94 if (estate_get_fuzzy_max(state).type)
95 return 1;
96 return 0;
97 }
98
99 void estate_set_fuzzy_max(struct smatch_state *state, sval_t fuzzy_max)
100 {
101 if (!rl_has_sval(estate_rl(state), fuzzy_max))
102 return;
103 get_dinfo(state)->fuzzy_max = fuzzy_max;
104 }
105
106 void estate_copy_fuzzy_max(struct smatch_state *new, struct smatch_state *old)
107 {
108 if (!estate_has_fuzzy_max(old))
109 return;
110 estate_set_fuzzy_max(new, estate_get_fuzzy_max(old));
111 }
112
113 void estate_clear_fuzzy_max(struct smatch_state *state)
114 {
115 sval_t empty = {};
116
117 get_dinfo(state)->fuzzy_max = empty;
118 }
119
120 int estate_has_hard_max(struct smatch_state *state)
121 {
122 if (!state || !estate_rl(state))
123 return 0;
124 return get_dinfo(state)->hard_max;
125 }
126
127 void estate_set_hard_max(struct smatch_state *state)
128 {
129 get_dinfo(state)->hard_max = 1;
130 }
131
132 void estate_clear_hard_max(struct smatch_state *state)
133 {
134 get_dinfo(state)->hard_max = 0;
135 }
136
137 int estate_get_hard_max(struct smatch_state *state, sval_t *sval)
138 {
139 if (!state || !get_dinfo(state)->hard_max || !estate_rl(state))
140 return 0;
141 *sval = rl_max(estate_rl(state));
142 return 1;
143 }
144
145 bool estate_capped(struct smatch_state *state)
146 {
147 if (!state)
148 return false;
149 /* impossible states are capped */
150 if (!estate_rl(state))
151 return true;
152 return get_dinfo(state)->capped;
153 }
154
155 void estate_set_capped(struct smatch_state *state)
156 {
157 get_dinfo(state)->capped = true;
158 }
159
160 bool estate_treat_untagged(struct smatch_state *state)
161 {
162 if (!state)
163 return false;
164
165 /* impossible states are capped */
166 if (!estate_rl(state))
167 return true;
168
169 return get_dinfo(state)->treat_untagged;
170 }
171
172 void estate_set_treat_untagged(struct smatch_state *state)
173 {
174 get_dinfo(state)->treat_untagged = true;
175 }
176
177 sval_t estate_min(struct smatch_state *state)
178 {
179 return rl_min(estate_rl(state));
180 }
181
182 sval_t estate_max(struct smatch_state *state)
183 {
184 return rl_max(estate_rl(state));
185 }
186
187 struct symbol *estate_type(struct smatch_state *state)
188 {
189 return rl_max(estate_rl(state)).type;
190 }
191
192 static int rlists_equiv(struct related_list *one, struct related_list *two)
193 {
194 struct relation *one_rel;
195 struct relation *two_rel;
196
197 PREPARE_PTR_LIST(one, one_rel);
198 PREPARE_PTR_LIST(two, two_rel);
199 for (;;) {
200 if (!one_rel && !two_rel)
201 return 1;
202 if (!one_rel || !two_rel)
203 return 0;
204 if (one_rel->sym != two_rel->sym)
205 return 0;
206 if (strcmp(one_rel->name, two_rel->name))
207 return 0;
208 NEXT_PTR_LIST(one_rel);
209 NEXT_PTR_LIST(two_rel);
210 }
211 FINISH_PTR_LIST(two_rel);
212 FINISH_PTR_LIST(one_rel);
213
214 return 1;
215 }
216
217 int estates_equiv(struct smatch_state *one, struct smatch_state *two)
218 {
219 if (!one || !two)
220 return 0;
221 if (one == two)
222 return 1;
223 if (!rlists_equiv(estate_related(one), estate_related(two)))
224 return 0;
225 if (estate_capped(one) != estate_capped(two))
226 return 0;
227 if (estate_treat_untagged(one) != estate_treat_untagged(two))
228 return 0;
229 if (strcmp(one->name, two->name) == 0)
230 return 1;
231 return 0;
232 }
233
234 int estate_is_whole(struct smatch_state *state)
235 {
236 return is_whole_rl(estate_rl(state));
237 }
238
239 int estate_is_empty(struct smatch_state *state)
240 {
241 return state && !estate_rl(state);
242 }
243
244 int estate_is_unknown(struct smatch_state *state)
245 {
246 if (!estate_is_whole(state))
247 return 0;
248 if (estate_related(state))
249 return 0;
250 if (estate_has_fuzzy_max(state))
251 return 0;
252 return 1;
253 }
254
255 int estate_get_single_value(struct smatch_state *state, sval_t *sval)
256 {
257 sval_t min, max;
258
259 if (!estate_rl(state))
260 return 0;
261 min = rl_min(estate_rl(state));
262 max = rl_max(estate_rl(state));
263 if (sval_cmp(min, max) != 0)
264 return 0;
265 *sval = min;
266 return 1;
267 }
268
269 static struct data_info *alloc_dinfo(void)
270 {
271 struct data_info *ret;
272
273 ret = __alloc_data_info(0);
274 memset(ret, 0, sizeof(*ret));
275 return ret;
276 }
277
278 static struct data_info *alloc_dinfo_range(sval_t min, sval_t max)
279 {
280 struct data_info *ret;
281
282 ret = alloc_dinfo();
283 add_range(&ret->value_ranges, min, max);
284 return ret;
285 }
286
287 static struct data_info *alloc_dinfo_range_list(struct range_list *rl)
288 {
289 struct data_info *ret;
290
291 ret = alloc_dinfo();
292 ret->value_ranges = rl;
293 return ret;
294 }
295
296 static struct data_info *clone_dinfo(struct data_info *dinfo)
297 {
298 struct data_info *ret;
299
300 ret = alloc_dinfo();
301 ret->related = clone_related_list(dinfo->related);
302 ret->value_ranges = clone_rl(dinfo->value_ranges);
303 ret->hard_max = dinfo->hard_max;
304 ret->fuzzy_max = dinfo->fuzzy_max;
305 return ret;
306 }
307
308 struct smatch_state *clone_estate(struct smatch_state *state)
309 {
310 struct smatch_state *ret;
311
312 if (!state)
313 return NULL;
314
315 ret = __alloc_smatch_state(0);
316 ret->name = state->name;
317 ret->data = clone_dinfo(get_dinfo(state));
318 return ret;
319 }
320
321 struct smatch_state *clone_partial_estate(struct smatch_state *state, struct range_list *rl)
322 {
323 struct smatch_state *ret;
324
325 if (!state)
326 return NULL;
327
328 rl = cast_rl(estate_type(state), rl);
329
330 ret = alloc_estate_rl(rl);
331 set_related(ret, clone_related_list(estate_related(state)));
332 if (estate_has_hard_max(state))
333 estate_set_hard_max(ret);
334 if (estate_has_fuzzy_max(state))
335 estate_set_fuzzy_max(ret, estate_get_fuzzy_max(state));
336
337 return ret;
338 }
339
340 struct smatch_state *alloc_estate_empty(void)
341 {
342 struct smatch_state *state;
343 struct data_info *dinfo;
344
345 dinfo = alloc_dinfo();
346 state = __alloc_smatch_state(0);
347 state->data = dinfo;
348 state->name = "";
349 return state;
350 }
351
352 struct smatch_state *alloc_estate_whole(struct symbol *type)
353 {
354 return alloc_estate_rl(alloc_whole_rl(type));
355 }
356
357 struct smatch_state *extra_empty(void)
358 {
359 struct smatch_state *ret;
360
361 ret = __alloc_smatch_state(0);
362 ret->name = "empty";
363 ret->data = alloc_dinfo();
364 return ret;
365 }
366
367 struct smatch_state *alloc_estate_sval(sval_t sval)
368 {
369 struct smatch_state *state;
370
371 state = __alloc_smatch_state(0);
372 state->data = alloc_dinfo_range(sval, sval);
373 state->name = show_rl(get_dinfo(state)->value_ranges);
374 estate_set_hard_max(state);
375 estate_set_fuzzy_max(state, sval);
376 return state;
377 }
378
379 struct smatch_state *alloc_estate_range(sval_t min, sval_t max)
380 {
381 struct smatch_state *state;
382
383 state = __alloc_smatch_state(0);
384 state->data = alloc_dinfo_range(min, max);
385 state->name = show_rl(get_dinfo(state)->value_ranges);
386 return state;
387 }
388
389 struct smatch_state *alloc_estate_rl(struct range_list *rl)
390 {
391 struct smatch_state *state;
392
393 if (!rl)
394 return extra_empty();
395
396 state = __alloc_smatch_state(0);
397 state->data = alloc_dinfo_range_list(rl);
398 state->name = show_rl(rl);
399 return state;
400 }
401
402 struct smatch_state *clone_estate_cast(struct symbol *type, struct smatch_state *state)
403 {
404 struct smatch_state *ret;
405 struct data_info *dinfo;
406
407 if (!state)
408 return NULL;
409
410 dinfo = alloc_dinfo();
411 dinfo->value_ranges = clone_rl(cast_rl(type, estate_rl(state)));
412
413 ret = __alloc_smatch_state(0);
414 ret->name = show_rl(dinfo->value_ranges);
415 ret->data = dinfo;
416
417 return ret;
418 }
419
420 struct smatch_state *get_implied_estate(struct expression *expr)
421 {
422 struct smatch_state *state;
423 struct range_list *rl;
424
425 state = get_state_expr(SMATCH_EXTRA, expr);
426 if (state)
427 return state;
428 if (!get_implied_rl(expr, &rl))
429 rl = alloc_whole_rl(get_type(expr));
430 return alloc_estate_rl(rl);
431 }
432
433 /*
434 * One of the complications is that smatch tries to free a bunch of data at the
435 * end of every function.
436 */
437 struct data_info *clone_dinfo_perm(struct data_info *dinfo)
438 {
439 struct data_info *ret;
440
441 ret = malloc(sizeof(*ret));
442 memset(ret, 0, sizeof(*ret));
443 ret->related = NULL;
444 ret->value_ranges = clone_rl_permanent(dinfo->value_ranges);
445 ret->hard_max = 0;
446 ret->fuzzy_max = dinfo->fuzzy_max;
447 return ret;
448 }
449
450 struct smatch_state *clone_estate_perm(struct smatch_state *state)
451 {
452 struct smatch_state *ret;
453
454 ret = malloc(sizeof(*ret));
455 ret->name = alloc_string(state->name);
456 ret->data = clone_dinfo_perm(get_dinfo(state));
457 return ret;
458 }
459
460