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