smatch_estate.c

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