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 static char *show_num(long long num)
  21 {
  22         static char buff[256];
  23
  24         if (num == whole_range.min) {
  25                 snprintf(buff, 255, "min");
  26         } else if (num == whole_range.max) {
  27                 snprintf(buff, 255, "max");
  28         } else if (num < 0) {
  29                 snprintf(buff, 255, "(%lld)", num);
  30         } else {
  31                 snprintf(buff, 255, "%lld", num);
  32         }
  33         buff[255] = '\0';
  34         return buff;
  35 }
  36
  37 char *show_ranges(struct range_list *list)
  38 {
  39         struct data_range *tmp;
  40         char full[256];
  41         int i = 0;
  42
  43         full[0] = '\0';
  44         full[255] = '\0';
  45         FOR_EACH_PTR(list, tmp) {
  46                 if (i++)
  47                         strncat(full, ",", 254 - strlen(full));
  48                 if (tmp->min == tmp->max) {
  49                         strncat(full, show_num(tmp->min), 254 - strlen(full));
  50                         continue;
  51                 }
  52                 strncat(full, show_num(tmp->min), 254 - strlen(full));
  53                 strncat(full, "-", 254 - strlen(full));
  54                 strncat(full, show_num(tmp->max), 254 - strlen(full));
  55         } END_FOR_EACH_PTR(tmp);
  56         return alloc_sname(full);
  57 }
  58
  59 static struct data_range range_zero = {
  60         .min = 0,
  61         .max = 0,
  62 };
  63
  64 static struct data_range range_one = {
  65         .min = 1,
  66         .max = 1,
  67 };
  68
  69 struct data_range *alloc_range(long long min, long long max)
  70 {
  71         struct data_range *ret;
  72
  73         if (min > max) {
  74                 printf("Error invalid range %lld to %lld\n", min, max);
  75         }
  76         if (min == whole_range.min && max == whole_range.max)
  77                 return &whole_range;
  78         if (min == 0 && max == 0)
  79                 return &range_zero;
  80         if (min == 1 && max == 1)
  81                 return &range_one;
  82         ret = __alloc_data_range(0);
  83         ret->min = min;
  84         ret->max = max;
  85         return ret;
  86 }
  87
  88 struct data_range *alloc_range_perm(long long min, long long max)
  89 {
  90         struct data_range *ret;
  91
  92         if (min > max) {
  93                 printf("Error invalid range %lld to %lld\n", min, max);
  94         }
  95         if (min == whole_range.min && max == whole_range.max)
  96                 return &whole_range;
  97         if (min == 0 && max == 0)
  98                 return &range_zero;
  99         if (min == 1 && max == 1)
 100                 return &range_one;
 101         ret = __alloc_perm_data_range(0);
 102         ret->min = min;
 103         ret->max = max;
 104         return ret;
 105 }
 106
 107 struct data_info *alloc_dinfo_range(long long min, long long max)
 108 {
 109         struct data_info *ret;
 110
 111         ret = __alloc_data_info(0);
 112         ret->type = DATA_RANGE;
 113         ret->value_ranges = NULL;
 114         add_range(&ret->value_ranges, min, max);
 115         return ret;
 116 }
 117
 118 struct data_info *alloc_dinfo_range_list(struct range_list *rl)
 119 {
 120         struct data_info *ret;
 121
 122         ret = __alloc_data_info(0);
 123         ret->type = DATA_RANGE;
 124         ret->value_ranges = rl;
 125         return ret;
 126 }
 127
 128 void add_range(struct range_list **list, long long min, long long max)
 129 {
 130         struct data_range *tmp = NULL;
 131         struct data_range *new = NULL;
 132         int check_next = 0;
 133
 134         FOR_EACH_PTR(*list, tmp) {
 135                 if (check_next) {
 136                         /* Sometimes we overlap with more than one range
 137                            so we have to delete or modify the next range. */
 138                         if (max + 1 == tmp->min) {
 139                                 /* join 2 ranges here */
 140                                 new->max = tmp->max;
 141                                 DELETE_CURRENT_PTR(tmp);
 142                                 return;
 143                         }
 144
 145                         /* Doesn't overlap with the next one. */
 146                         if (max < tmp->min)
 147                                 return;
 148                         /* Partially overlaps with the next one. */
 149                         if (max < tmp->max) {
 150                                 tmp->min = max + 1;
 151                                 return;
 152                         }
 153                         /* Completely overlaps with the next one. */
 154                         if (max >= tmp->max) {
 155                                 DELETE_CURRENT_PTR(tmp);
 156                                 /* there could be more ranges to delete */
 157                                 continue;
 158                         }
 159                 }
 160                 if (max != whole_range.max && max + 1 == tmp->min) {
 161                         /* join 2 ranges into a big range */
 162                         new = alloc_range(min, tmp->max);
 163                         REPLACE_CURRENT_PTR(tmp, new);
 164                         return;
 165                 }
 166                 if (max < tmp->min) {  /* new range entirely below */
 167                         new = alloc_range(min, max);
 168                         INSERT_CURRENT(new, tmp);
 169                         return;
 170                 }
 171                 if (min < tmp->min) { /* new range partially below */
 172                         if (max < tmp->max)
 173                                 max = tmp->max;
 174                         else
 175                                 check_next = 1;
 176                         new = alloc_range(min, max);
 177                         REPLACE_CURRENT_PTR(tmp, new);
 178                         if (!check_next)
 179                                 return;
 180                         continue;
 181                 }
 182                 if (max <= tmp->max) /* new range already included */
 183                         return;
 184                 if (min <= tmp->max) { /* new range partially above */
 185                         min = tmp->min;
 186                         new = alloc_range(min, max);
 187                         REPLACE_CURRENT_PTR(tmp, new);
 188                         check_next = 1;
 189                         continue;
 190                 }
 191                 if (min != whole_range.min && min - 1 == tmp->max) {
 192                         /* join 2 ranges into a big range */
 193                         new = alloc_range(tmp->min, max);
 194                         REPLACE_CURRENT_PTR(tmp, new);
 195                         check_next = 1;
 196                         continue;
 197                 }
 198                 /* the new range is entirely above the existing ranges */
 199         } END_FOR_EACH_PTR(tmp);
 200         if (check_next)
 201                 return;
 202         new = alloc_range(min, max);
 203         add_ptr_list(list, new);
 204 }
 205
 206 struct range_list *clone_range_list(struct range_list *list)
 207 {
 208         struct data_range *tmp;
 209         struct range_list *ret = NULL;
 210
 211         FOR_EACH_PTR(list, tmp) {
 212                 add_ptr_list(&ret, tmp);
 213         } END_FOR_EACH_PTR(tmp);
 214         return ret;
 215 }
 216
 217 struct range_list *range_list_union(struct range_list *one, struct range_list *two)
 218 {
 219         struct data_range *tmp;
 220         struct range_list *ret = NULL;
 221
 222         FOR_EACH_PTR(one, tmp) {
 223                 add_range(&ret, tmp->min, tmp->max);
 224         } END_FOR_EACH_PTR(tmp);
 225         FOR_EACH_PTR(two, tmp) {
 226                 add_range(&ret, tmp->min, tmp->max);
 227         } END_FOR_EACH_PTR(tmp);
 228         return ret;
 229 }
 230
 231 struct range_list *remove_range(struct range_list *list, long long min, long long max)
 232 {
 233         struct data_range *tmp;
 234         struct range_list *ret = NULL;
 235
 236         FOR_EACH_PTR(list, tmp) {
 237                 if (tmp->max < min) {
 238                         add_range(&ret, tmp->min, tmp->max);
 239                         continue;
 240                 }
 241                 if (tmp->min > max) {
 242                         add_range(&ret, tmp->min, tmp->max);
 243                         continue;
 244                 }
 245                 if (tmp->min >= min && tmp->max <= max)
 246                         continue;
 247                 if (tmp->min >= min) {
 248                         add_range(&ret, max + 1, tmp->max);
 249                 } else if (tmp->max <= max) {
 250                         add_range(&ret, tmp->min, min - 1);
 251                 } else {
 252                         add_range(&ret, tmp->min, min - 1);
 253                         add_range(&ret, max + 1, tmp->max);
 254                 }
 255         } END_FOR_EACH_PTR(tmp);
 256         return ret;
 257 }
 258
 259 long long get_dinfo_min(struct data_info *dinfo)
 260 {
 261         struct data_range *drange;
 262
 263         if (!dinfo || !dinfo->value_ranges)
 264                 return whole_range.min;
 265         drange = first_ptr_list((struct ptr_list *)dinfo->value_ranges);
 266         return drange->min;
 267 }
 268
 269 long long get_dinfo_max(struct data_info *dinfo)
 270 {
 271         struct data_range *drange;
 272
 273         if (!dinfo || !dinfo->value_ranges)
 274                 return whole_range.max;
 275         drange = first_ptr_list((struct ptr_list *)dinfo->value_ranges);
 276         return drange->max;
 277 }
 278
 279 /*
 280  * if it can be only one and only value return 1, else return 0
 281  */
 282 int get_single_value_from_range(struct data_info *dinfo, long long *val)
 283 {
 284         struct data_range *tmp;
 285         int count = 0;
 286
 287         if (dinfo->type != DATA_RANGE)
 288                 return 0;
 289
 290         FOR_EACH_PTR(dinfo->value_ranges, tmp) {
 291                 if (!count++) {
 292                         if (tmp->min != tmp->max)
 293                                 return 0;
 294                         *val = tmp->min;
 295                 } else {
 296                         return 0;
 297                 }
 298         } END_FOR_EACH_PTR(tmp);
 299         return count;
 300 }
 301
 302 int true_comparison_range(struct data_range *left, int comparison, struct data_range *right)
 303 {
 304         switch(comparison){
 305         case '<':
 306         case SPECIAL_UNSIGNED_LT:
 307                 if (left->min < right->max)
 308                         return 1;
 309                 return 0;
 310         case SPECIAL_UNSIGNED_LTE:
 311         case SPECIAL_LTE:
 312                 if (left->min <= right->max)
 313                         return 1;
 314                 return 0;
 315         case SPECIAL_EQUAL:
 316                 if (left->max < right->min)
 317                         return 0;
 318                 if (left->min > right->max)
 319                         return 0;
 320                 return 1;
 321         case SPECIAL_UNSIGNED_GTE:
 322         case SPECIAL_GTE:
 323                 if (left->max >= right->min)
 324                         return 1;
 325                 return 0;
 326         case '>':
 327         case SPECIAL_UNSIGNED_GT:
 328                 if (left->max > right->min)
 329                         return 1;
 330                 return 0;
 331         case SPECIAL_NOTEQUAL:
 332                 if (left->min != left->max)
 333                         return 1;
 334                 if (right->min != right->max)
 335                         return 1;
 336                 if (left->min != right->min)
 337                         return 1;
 338                 return 0;
 339         default:
 340                 sm_msg("unhandled comparison %d\n", comparison);
 341                 return 0;
 342         }
 343         return 0;
 344 }
 345
 346 int true_comparison_range_lr(int comparison, struct data_range *var, struct data_range *val, int left)
 347 {
 348         if (left)
 349                 return true_comparison_range(var, comparison, val);
 350         else
 351                 return true_comparison_range(val, comparison, var);
 352 }
 353
 354 static int false_comparison_range(struct data_range *left, int comparison, struct data_range *right)
 355 {
 356         switch(comparison){
 357         case '<':
 358         case SPECIAL_UNSIGNED_LT:
 359                 if (left->max >= right->min)
 360                         return 1;
 361                 return 0;
 362         case SPECIAL_UNSIGNED_LTE:
 363         case SPECIAL_LTE:
 364                 if (left->max > right->min)
 365                         return 1;
 366                 return 0;
 367         case SPECIAL_EQUAL:
 368                 if (left->min != left->max)
 369                         return 1;
 370                 if (right->min != right->max)
 371                         return 1;
 372                 if (left->min != right->min)
 373                         return 1;
 374                 return 0;
 375         case SPECIAL_UNSIGNED_GTE:
 376         case SPECIAL_GTE:
 377                 if (left->min < right->max)
 378                         return 1;
 379                 return 0;
 380         case '>':
 381         case SPECIAL_UNSIGNED_GT:
 382                 if (left->min <= right->max)
 383                         return 1;
 384                 return 0;
 385         case SPECIAL_NOTEQUAL:
 386                 if (left->max < right->min)
 387                         return 0;
 388                 if (left->min > right->max)
 389                         return 0;
 390                 return 1;
 391         default:
 392                 sm_msg("unhandled comparison %d\n", comparison);
 393                 return 0;
 394         }
 395         return 0;
 396 }
 397
 398 int false_comparison_range_lr(int comparison, struct data_range *var, struct data_range *val, int left)
 399 {
 400         if (left)
 401                 return false_comparison_range(var, comparison, val);
 402         else
 403                 return false_comparison_range(val, comparison, var);
 404 }
 405
 406 int possibly_true(int comparison, struct data_info *dinfo, int num, int left)
 407 {
 408         struct data_range *tmp;
 409         struct data_range drange;
 410
 411         drange.min = num;
 412         drange.max = num;
 413
 414         FOR_EACH_PTR(dinfo->value_ranges, tmp) {
 415                 if (true_comparison_range_lr(comparison, tmp, &drange, left))
 416                         return 1;
 417         } END_FOR_EACH_PTR(tmp);
 418         return 0;
 419 }
 420
 421 int possibly_false(int comparison, struct data_info *dinfo, int num, int left)
 422 {
 423         struct data_range *tmp;
 424         struct data_range drange;
 425
 426         drange.min = num;
 427         drange.max = num;
 428
 429         FOR_EACH_PTR(dinfo->value_ranges, tmp) {
 430                 if (false_comparison_range_lr(comparison, tmp, &drange, left))
 431                         return 1;
 432         } END_FOR_EACH_PTR(tmp);
 433         return 0;
 434 }
 435
 436 int possibly_true_range_list(int comparison, struct data_info *dinfo, struct range_list *values, int left)
 437 {
 438         struct data_range *tmp, *tmp2;
 439
 440         FOR_EACH_PTR(dinfo->value_ranges, tmp) {
 441                 FOR_EACH_PTR(values, tmp2) {
 442                         if (true_comparison_range_lr(comparison, tmp, tmp2, left))
 443                                 return 1;
 444                 } END_FOR_EACH_PTR(tmp2);
 445         } END_FOR_EACH_PTR(tmp);
 446         return 0;
 447 }
 448
 449 int possibly_false_range_list(int comparison, struct data_info *dinfo, struct range_list *values, int left)
 450 {
 451         struct data_range *tmp, *tmp2;
 452
 453         FOR_EACH_PTR(dinfo->value_ranges, tmp) {
 454                 FOR_EACH_PTR(values, tmp2) {
 455                         if (false_comparison_range_lr(comparison, tmp, tmp2, left))
 456                                 return 1;
 457                 } END_FOR_EACH_PTR(tmp2);
 458         } END_FOR_EACH_PTR(tmp);
 459         return 0;
 460 }
 461
 462 void tack_on(struct range_list **list, struct data_range *drange)
 463 {
 464         add_ptr_list(list, drange);
 465 }
 466
 467 int in_list_exact(struct range_list *list, struct data_range *drange)
 468 {
 469         struct data_range *tmp;
 470
 471         FOR_EACH_PTR(list, tmp) {
 472                 if (tmp->min == drange->min && tmp->max == drange->max)
 473                         return 1;
 474         } END_FOR_EACH_PTR(tmp);
 475         return 0;
 476
 477 }
 478
 479 void push_range_list(struct range_list_stack **rl_stack, struct range_list *rl)
 480 {
 481         add_ptr_list(rl_stack, rl);
 482 }
 483
 484 struct range_list *pop_range_list(struct range_list_stack **rl_stack)
 485 {
 486         struct range_list *rl;
 487
 488         rl = last_ptr_list((struct ptr_list *)*rl_stack);
 489         delete_ptr_list_last((struct ptr_list **)rl_stack);
 490         return rl;
 491 }
 492
 493 struct range_list *top_range_list(struct range_list_stack *rl_stack)
 494 {
 495         struct range_list *rl;
 496
 497         rl = last_ptr_list((struct ptr_list *)rl_stack);
 498         return rl;
 499 }
 500
 501 void filter_top_range_list(struct range_list_stack **rl_stack, long long num)
 502 {
 503         struct range_list *rl;
 504
 505         rl = pop_range_list(rl_stack);
 506         rl = remove_range(rl, num, num);
 507         push_range_list(rl_stack, rl);
 508 }
 509
 510 static void free_single_dinfo(struct data_info *dinfo)
 511 {
 512         if (dinfo->type == DATA_RANGE)
 513                 __free_ptr_list((struct ptr_list **)&dinfo->value_ranges);
 514 }
 515
 516 static void free_dinfos(struct allocation_blob *blob)
 517 {
 518         unsigned int size = sizeof(struct data_info);
 519         unsigned int offset = 0;
 520
 521         while (offset < blob->offset) {
 522                 free_single_dinfo((struct data_info *)(blob->data + offset));
 523                 offset += size;
 524         }
 525 }
 526
 527 void free_data_info_allocs(void)
 528 {
 529         struct allocator_struct *desc = &data_info_allocator;
 530         struct allocation_blob *blob = desc->blobs;
 531
 532         desc->blobs = NULL;
 533         desc->allocations = 0;
 534         desc->total_bytes = 0;
 535         desc->useful_bytes = 0;
 536         desc->freelist = NULL;
 537         while (blob) {
 538                 struct allocation_blob *next = blob->next;
 539                 free_dinfos(blob);
 540                 blob_free(blob, desc->chunking);
 541                 blob = next;
 542         }
 543         clear_data_range_alloc();
 544 }
 545