smatch_ranges.c

   1 /*
   2  * sparse/smatch_ranges.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "parse.h"
  11 #include "smatch.h"
  12 #include "smatch_extra.h"
  13 #include "smatch_slist.h"
  14
  15 ALLOCATOR(data_info, "smatch extra data");
  16 ALLOCATOR(data_range, "data range");
  17 __DO_ALLOCATOR(struct data_range, sizeof(struct data_range), __alignof__(struct data_range),
  18                          "permanent ranges", perm_data_range);
  19
  20 struct data_range whole_range = {
  21         .min = LLONG_MIN,
  22         .max = LLONG_MAX,
  23 };
  24
  25 static char *show_num(long long num)
  26 {
  27         static char buff[256];
  28
  29         if (num == whole_range.min)
  30                 snprintf(buff, 255, "min");
  31         else if (num == whole_range.max)
  32                 snprintf(buff, 255, "max");
  33         else if (num < 0)
  34                 snprintf(buff, 255, "(%lld)", num);
  35         else
  36                 snprintf(buff, 255, "%lld", num);
  37
  38         buff[255] = '\0';
  39         return buff;
  40 }
  41
  42 char *show_ranges(struct range_list *list)
  43 {
  44         struct data_range *tmp;
  45         char full[256];
  46         int i = 0;
  47
  48         full[0] = '\0';
  49         full[255] = '\0';
  50         FOR_EACH_PTR(list, tmp) {
  51                 if (i++)
  52                         strncat(full, ",", 254 - strlen(full));
  53                 if (tmp->min == tmp->max) {
  54                         strncat(full, show_num(tmp->min), 254 - strlen(full));
  55                         continue;
  56                 }
  57                 strncat(full, show_num(tmp->min), 254 - strlen(full));
  58                 strncat(full, "-", 254 - strlen(full));
  59                 strncat(full, show_num(tmp->max), 254 - strlen(full));
  60         } END_FOR_EACH_PTR(tmp);
  61         return alloc_sname(full);
  62 }
  63
  64 void get_value_ranges(char *value, struct range_list **rl)
  65 {
  66         long long val1, val2;
  67         char *start;
  68         char *c;
  69
  70         *rl = NULL;
  71
  72         c = value;
  73         while (*c) {
  74                 if (*c == '(')
  75                         c++;
  76                 start = c;
  77                 if (!strncmp(start, "min", 3)) {
  78                         val1 = LLONG_MIN;
  79                         c += 3;
  80                 } else {
  81                         while (*c && *c != ',' && *c != '-')
  82                                 c++;
  83                         val1 = strtoll(start, &c, 10);
  84                 }
  85                 if (*c == ')')
  86                         c++;
  87                 if (!*c) {
  88                         add_range(rl, val1, val1);
  89                         break;
  90                 }
  91                 if (*c == ',') {
  92                         add_range(rl, val1, val1);
  93                         c++;
  94                         start = c;
  95                         continue;
  96                 }
  97                 c++; /* skip the dash in eg. 4-5 */
  98                 if (*c == '(')
  99                         c++;
 100                 start = c;
 101                 if (!strncmp(start, "max", 3)) {
 102                         val2 = LLONG_MAX;
 103                         c += 3;
 104                 } else {
 105
 106                         while (*c && *c != ',' && *c != '-')
 107                                 c++;
 108                         val2 = strtoll(start, &c, 10);
 109                 }
 110                 add_range(rl, val1, val2);
 111                 if (!*c)
 112                         break;
 113                 if (*c == ')')
 114                         c++;
 115                 c++; /* skip the comma in eg: 4-5,7 */
 116         }
 117
 118 }
 119
 120 static struct data_range range_zero = {
 121         .min = 0,
 122         .max = 0,
 123 };
 124
 125 static struct data_range range_one = {
 126         .min = 1,
 127         .max = 1,
 128 };
 129
 130 int is_whole_range_rl(struct range_list *rl)
 131 {
 132         struct data_range *drange;
 133
 134         if (ptr_list_empty(rl))
 135                 return 1;
 136         drange = first_ptr_list((struct ptr_list *)rl);
 137         if (drange->min == whole_range.min && drange->max == whole_range.max)
 138                 return 1;
 139         return 0;
 140 }
 141
 142 long long rl_min(struct range_list *rl)
 143 {
 144         struct data_range *drange;
 145
 146         if (ptr_list_empty(rl))
 147                 return whole_range.min;
 148         drange = first_ptr_list((struct ptr_list *)rl);
 149         return drange->min;
 150 }
 151
 152 long long rl_max(struct range_list *rl)
 153 {
 154         struct data_range *drange;
 155
 156         if (ptr_list_empty(rl))
 157                 return whole_range.max;
 158         drange = last_ptr_list((struct ptr_list *)rl);
 159         return drange->max;
 160 }
 161
 162 static struct data_range *alloc_range_helper(long long min, long long max, int perm)
 163 {
 164         struct data_range *ret;
 165
 166         if (min > max) {
 167                 sm_msg("Error invalid range %lld to %lld", min, max);
 168                 min = whole_range.min;
 169                 max = whole_range.max;
 170         }
 171         if (min == whole_range.min && max == whole_range.max)
 172                 return &whole_range;
 173         if (min == 0 && max == 0)
 174                 return &range_zero;
 175         if (min == 1 && max == 1)
 176                 return &range_one;
 177
 178         if (perm)
 179                 ret = __alloc_perm_data_range(0);
 180         else
 181                 ret = __alloc_data_range(0);
 182         ret->min = min;
 183         ret->max = max;
 184         return ret;
 185 }
 186
 187 struct data_range *alloc_range(long long min, long long max)
 188 {
 189         return alloc_range_helper(min, max, 0);
 190 }
 191
 192 struct data_range *alloc_range_perm(long long min, long long max)
 193 {
 194         return alloc_range_helper(min, max, 1);
 195 }
 196
 197 struct range_list *alloc_range_list(long long min, long long max)
 198 {
 199         struct range_list *rl = NULL;
 200
 201         add_range(&rl, min, max);
 202         return rl;
 203 }
 204
 205 struct range_list *whole_range_list(void)
 206 {
 207         return alloc_range_list(whole_range.min, whole_range.max);
 208 }
 209
 210 void add_range(struct range_list **list, long long min, long long max)
 211 {
 212         struct data_range *tmp = NULL;
 213         struct data_range *new = NULL;
 214         int check_next = 0;
 215
 216         /*
 217          * FIXME:  This has a problem merging a range_list like: min-0,3-max
 218          * with a range like 1-2.  You end up with min-2,3-max instead of
 219          * just min-max.
 220          */
 221         FOR_EACH_PTR(*list, tmp) {
 222                 if (check_next) {
 223                         /* Sometimes we overlap with more than one range
 224                            so we have to delete or modify the next range. */
 225                         if (max + 1 == tmp->min) {
 226                                 /* join 2 ranges here */
 227                                 new->max = tmp->max;
 228                                 DELETE_CURRENT_PTR(tmp);
 229                                 return;
 230                         }
 231
 232                         /* Doesn't overlap with the next one. */
 233                         if (max < tmp->min)
 234                                 return;
 235                         /* Partially overlaps with the next one. */
 236                         if (max < tmp->max) {
 237                                 tmp->min = max + 1;
 238                                 return;
 239                         }
 240                         /* Completely overlaps with the next one. */
 241                         if (max >= tmp->max) {
 242                                 DELETE_CURRENT_PTR(tmp);
 243                                 /* there could be more ranges to delete */
 244                                 continue;
 245                         }
 246                 }
 247                 if (max != whole_range.max && max + 1 == tmp->min) {
 248                         /* join 2 ranges into a big range */
 249                         new = alloc_range(min, tmp->max);
 250                         REPLACE_CURRENT_PTR(tmp, new);
 251                         return;
 252                 }
 253                 if (max < tmp->min) {  /* new range entirely below */
 254                         new = alloc_range(min, max);
 255                         INSERT_CURRENT(new, tmp);
 256                         return;
 257                 }
 258                 if (min < tmp->min) { /* new range partially below */
 259                         if (max < tmp->max)
 260                                 max = tmp->max;
 261                         else
 262                                 check_next = 1;
 263                         new = alloc_range(min, max);
 264                         REPLACE_CURRENT_PTR(tmp, new);
 265                         if (!check_next)
 266                                 return;
 267                         continue;
 268                 }
 269                 if (max <= tmp->max) /* new range already included */
 270                         return;
 271                 if (min <= tmp->max) { /* new range partially above */
 272                         min = tmp->min;
 273                         new = alloc_range(min, max);
 274                         REPLACE_CURRENT_PTR(tmp, new);
 275                         check_next = 1;
 276                         continue;
 277                 }
 278                 if (min != whole_range.min && min - 1 == tmp->max) {
 279                         /* join 2 ranges into a big range */
 280                         new = alloc_range(tmp->min, max);
 281                         REPLACE_CURRENT_PTR(tmp, new);
 282                         check_next = 1;
 283                         continue;
 284                 }
 285                 /* the new range is entirely above the existing ranges */
 286         } END_FOR_EACH_PTR(tmp);
 287         if (check_next)
 288                 return;
 289         new = alloc_range(min, max);
 290         add_ptr_list(list, new);
 291 }
 292
 293 struct range_list *clone_range_list(struct range_list *list)
 294 {
 295         struct data_range *tmp;
 296         struct range_list *ret = NULL;
 297
 298         FOR_EACH_PTR(list, tmp) {
 299                 add_ptr_list(&ret, tmp);
 300         } END_FOR_EACH_PTR(tmp);
 301         return ret;
 302 }
 303
 304 struct range_list *clone_permanent(struct range_list *list)
 305 {
 306         struct data_range *tmp;
 307         struct data_range *new;
 308         struct range_list *ret = NULL;
 309
 310         FOR_EACH_PTR(list, tmp) {
 311                 new = alloc_range_perm(tmp->min, tmp->max);
 312                 add_ptr_list(&ret, new);
 313         } END_FOR_EACH_PTR(tmp);
 314         return ret;
 315 }
 316
 317 struct range_list *range_list_union(struct range_list *one, struct range_list *two)
 318 {
 319         struct data_range *tmp;
 320         struct range_list *ret = NULL;
 321
 322         FOR_EACH_PTR(one, tmp) {
 323                 add_range(&ret, tmp->min, tmp->max);
 324         } END_FOR_EACH_PTR(tmp);
 325         FOR_EACH_PTR(two, tmp) {
 326                 add_range(&ret, tmp->min, tmp->max);
 327         } END_FOR_EACH_PTR(tmp);
 328         return ret;
 329 }
 330
 331 struct range_list *remove_range(struct range_list *list, long long min, long long max)
 332 {
 333         struct data_range *tmp;
 334         struct range_list *ret = NULL;
 335
 336         FOR_EACH_PTR(list, tmp) {
 337                 if (tmp->max < min) {
 338                         add_range(&ret, tmp->min, tmp->max);
 339                         continue;
 340                 }
 341                 if (tmp->min > max) {
 342                         add_range(&ret, tmp->min, tmp->max);
 343                         continue;
 344                 }
 345                 if (tmp->min >= min && tmp->max <= max)
 346                         continue;
 347                 if (tmp->min >= min) {
 348                         add_range(&ret, max + 1, tmp->max);
 349                 } else if (tmp->max <= max) {
 350                         add_range(&ret, tmp->min, min - 1);
 351                 } else {
 352                         add_range(&ret, tmp->min, min - 1);
 353                         add_range(&ret, max + 1, tmp->max);
 354                 }
 355         } END_FOR_EACH_PTR(tmp);
 356         return ret;
 357 }
 358
 359 /*
 360  * if it can be only one and only value return 1, else return 0
 361  */
 362 int estate_get_single_value(struct smatch_state *state, long long *val)
 363 {
 364         struct data_info *dinfo;
 365         struct data_range *tmp;
 366         int count = 0;
 367
 368         dinfo = get_dinfo(state);
 369         if (!dinfo || dinfo->type != DATA_RANGE)
 370                 return 0;
 371
 372         FOR_EACH_PTR(dinfo->value_ranges, tmp) {
 373                 if (!count++) {
 374                         if (tmp->min != tmp->max)
 375                                 return 0;
 376                         *val = tmp->min;
 377                 } else {
 378                         return 0;
 379                 }
 380         } END_FOR_EACH_PTR(tmp);
 381         return count;
 382 }
 383
 384 int range_lists_equiv(struct range_list *one, struct range_list *two)
 385 {
 386         struct data_range *one_range;
 387         struct data_range *two_range;
 388
 389         PREPARE_PTR_LIST(one, one_range);
 390         PREPARE_PTR_LIST(two, two_range);
 391         for (;;) {
 392                 if (!one_range && !two_range)
 393                         return 1;
 394                 if (!one_range || !two_range)
 395                         return 0;
 396                 if (one_range->min != two_range->min)
 397                         return 0;
 398                 if (one_range->max != two_range->max)
 399                         return 0;
 400                 NEXT_PTR_LIST(one_range);
 401                 NEXT_PTR_LIST(two_range);
 402         }
 403         FINISH_PTR_LIST(two_range);
 404         FINISH_PTR_LIST(one_range);
 405
 406         return 1;
 407 }
 408
 409 int true_comparison_range(struct data_range *left, int comparison, struct data_range *right)
 410 {
 411         switch (comparison) {
 412         case '<':
 413         case SPECIAL_UNSIGNED_LT:
 414                 if (left->min < right->max)
 415                         return 1;
 416                 return 0;
 417         case SPECIAL_UNSIGNED_LTE:
 418         case SPECIAL_LTE:
 419                 if (left->min <= right->max)
 420                         return 1;
 421                 return 0;
 422         case SPECIAL_EQUAL:
 423                 if (left->max < right->min)
 424                         return 0;
 425                 if (left->min > right->max)
 426                         return 0;
 427                 return 1;
 428         case SPECIAL_UNSIGNED_GTE:
 429         case SPECIAL_GTE:
 430                 if (left->max >= right->min)
 431                         return 1;
 432                 return 0;
 433         case '>':
 434         case SPECIAL_UNSIGNED_GT:
 435                 if (left->max > right->min)
 436                         return 1;
 437                 return 0;
 438         case SPECIAL_NOTEQUAL:
 439                 if (left->min != left->max)
 440                         return 1;
 441                 if (right->min != right->max)
 442                         return 1;
 443                 if (left->min != right->min)
 444                         return 1;
 445                 return 0;
 446         default:
 447                 sm_msg("unhandled comparison %d\n", comparison);
 448                 return 0;
 449         }
 450         return 0;
 451 }
 452
 453 int true_comparison_range_lr(int comparison, struct data_range *var, struct data_range *val, int left)
 454 {
 455         if (left)
 456                 return true_comparison_range(var, comparison, val);
 457         else
 458                 return true_comparison_range(val, comparison, var);
 459 }
 460
 461 static int false_comparison_range(struct data_range *left, int comparison, struct data_range *right)
 462 {
 463         switch (comparison) {
 464         case '<':
 465         case SPECIAL_UNSIGNED_LT:
 466                 if (left->max >= right->min)
 467                         return 1;
 468                 return 0;
 469         case SPECIAL_UNSIGNED_LTE:
 470         case SPECIAL_LTE:
 471                 if (left->max > right->min)
 472                         return 1;
 473                 return 0;
 474         case SPECIAL_EQUAL:
 475                 if (left->min != left->max)
 476                         return 1;
 477                 if (right->min != right->max)
 478                         return 1;
 479                 if (left->min != right->min)
 480                         return 1;
 481                 return 0;
 482         case SPECIAL_UNSIGNED_GTE:
 483         case SPECIAL_GTE:
 484                 if (left->min < right->max)
 485                         return 1;
 486                 return 0;
 487         case '>':
 488         case SPECIAL_UNSIGNED_GT:
 489                 if (left->min <= right->max)
 490                         return 1;
 491                 return 0;
 492         case SPECIAL_NOTEQUAL:
 493                 if (left->max < right->min)
 494                         return 0;
 495                 if (left->min > right->max)
 496                         return 0;
 497                 return 1;
 498         default:
 499                 sm_msg("unhandled comparison %d\n", comparison);
 500                 return 0;
 501         }
 502         return 0;
 503 }
 504
 505 int false_comparison_range_lr(int comparison, struct data_range *var, struct data_range *val, int left)
 506 {
 507         if (left)
 508                 return false_comparison_range(var, comparison, val);
 509         else
 510                 return false_comparison_range(val, comparison, var);
 511 }
 512
 513 int possibly_true(struct expression *left, int comparison, struct expression *right)
 514 {
 515         struct range_list *rl_left, *rl_right;
 516         struct data_range *tmp_left, *tmp_right;
 517
 518         if (!get_implied_range_list(left, &rl_left))
 519                 return 1;
 520         if (!get_implied_range_list(right, &rl_right))
 521                 return 1;
 522
 523         FOR_EACH_PTR(rl_left, tmp_left) {
 524                 FOR_EACH_PTR(rl_right, tmp_right) {
 525                         if (true_comparison_range(tmp_left, comparison, tmp_right))
 526                                 return 1;
 527                 } END_FOR_EACH_PTR(tmp_right);
 528         } END_FOR_EACH_PTR(tmp_left);
 529         return 0;
 530 }
 531
 532 int possibly_false(struct expression *left, int comparison, struct expression *right)
 533 {
 534         struct range_list *rl_left, *rl_right;
 535         struct data_range *tmp_left, *tmp_right;
 536
 537         if (!get_implied_range_list(left, &rl_left))
 538                 return 1;
 539         if (!get_implied_range_list(right, &rl_right))
 540                 return 1;
 541
 542         FOR_EACH_PTR(rl_left, tmp_left) {
 543                 FOR_EACH_PTR(rl_right, tmp_right) {
 544                         if (false_comparison_range(tmp_left, comparison, tmp_right))
 545                                 return 1;
 546                 } END_FOR_EACH_PTR(tmp_right);
 547         } END_FOR_EACH_PTR(tmp_left);
 548         return 0;
 549 }
 550
 551 int possibly_true_range_lists(struct range_list *left_ranges, int comparison, struct range_list *right_ranges)
 552 {
 553         struct data_range *left_tmp, *right_tmp;
 554
 555         if (!left_ranges || !right_ranges)
 556                 return 1;
 557
 558         FOR_EACH_PTR(left_ranges, left_tmp) {
 559                 FOR_EACH_PTR(right_ranges, right_tmp) {
 560                         if (true_comparison_range(left_tmp, comparison, right_tmp))
 561                                 return 1;
 562                 } END_FOR_EACH_PTR(right_tmp);
 563         } END_FOR_EACH_PTR(left_tmp);
 564         return 0;
 565 }
 566
 567 int possibly_false_range_lists(struct range_list *left_ranges, int comparison, struct range_list *right_ranges)
 568 {
 569         struct data_range *left_tmp, *right_tmp;
 570
 571         if (!left_ranges || !right_ranges)
 572                 return 1;
 573
 574         FOR_EACH_PTR(left_ranges, left_tmp) {
 575                 FOR_EACH_PTR(right_ranges, right_tmp) {
 576                         if (false_comparison_range(left_tmp, comparison, right_tmp))
 577                                 return 1;
 578                 } END_FOR_EACH_PTR(right_tmp);
 579         } END_FOR_EACH_PTR(left_tmp);
 580         return 0;
 581 }
 582
 583 void tack_on(struct range_list **list, struct data_range *drange)
 584 {
 585         add_ptr_list(list, drange);
 586 }
 587
 588 int in_list_exact(struct range_list *list, struct data_range *drange)
 589 {
 590         struct data_range *tmp;
 591
 592         FOR_EACH_PTR(list, tmp) {
 593                 if (tmp->min == drange->min && tmp->max == drange->max)
 594                         return 1;
 595         } END_FOR_EACH_PTR(tmp);
 596         return 0;
 597
 598 }
 599
 600 void push_range_list(struct range_list_stack **rl_stack, struct range_list *rl)
 601 {
 602         add_ptr_list(rl_stack, rl);
 603 }
 604
 605 struct range_list *pop_range_list(struct range_list_stack **rl_stack)
 606 {
 607         struct range_list *rl;
 608
 609         rl = last_ptr_list((struct ptr_list *)*rl_stack);
 610         delete_ptr_list_last((struct ptr_list **)rl_stack);
 611         return rl;
 612 }
 613
 614 struct range_list *top_range_list(struct range_list_stack *rl_stack)
 615 {
 616         struct range_list *rl;
 617
 618         rl = last_ptr_list((struct ptr_list *)rl_stack);
 619         return rl;
 620 }
 621
 622 void filter_top_range_list(struct range_list_stack **rl_stack, long long num)
 623 {
 624         struct range_list *rl;
 625
 626         rl = pop_range_list(rl_stack);
 627         rl = remove_range(rl, num, num);
 628         push_range_list(rl_stack, rl);
 629 }
 630
 631 void free_range_list(struct range_list **rlist)
 632 {
 633         __free_ptr_list((struct ptr_list **)rlist);
 634 }
 635
 636 static void free_single_dinfo(struct data_info *dinfo)
 637 {
 638         if (dinfo->type == DATA_RANGE)
 639                 free_range_list(&dinfo->value_ranges);
 640 }
 641
 642 static void free_dinfos(struct allocation_blob *blob)
 643 {
 644         unsigned int size = sizeof(struct data_info);
 645         unsigned int offset = 0;
 646
 647         while (offset < blob->offset) {
 648                 free_single_dinfo((struct data_info *)(blob->data + offset));
 649                 offset += size;
 650         }
 651 }
 652
 653 void free_data_info_allocs(void)
 654 {
 655         struct allocator_struct *desc = &data_info_allocator;
 656         struct allocation_blob *blob = desc->blobs;
 657
 658         desc->blobs = NULL;
 659         desc->allocations = 0;
 660         desc->total_bytes = 0;
 661         desc->useful_bytes = 0;
 662         desc->freelist = NULL;
 663         while (blob) {
 664                 struct allocation_blob *next = blob->next;
 665                 free_dinfos(blob);
 666                 blob_free(blob, desc->chunking);
 667                 blob = next;
 668         }
 669         clear_data_range_alloc();
 670 }
 671