smatch_extra.c

   1 /*
   2  * sparse/smatch_extra.c
   3  *
   4  * Copyright (C) 2008 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * smatch_extra.c is supposed to track the value of every variable.
  12  *
  13  */
  14
  15 #include <stdlib.h>
  16 #include <errno.h>
  17 #ifndef __USE_ISOC99
  18 #define __USE_ISOC99
  19 #endif
  20 #include <limits.h>
  21 #include "parse.h"
  22 #include "smatch.h"
  23 #include "smatch_slist.h"
  24 #include "smatch_extra.h"
  25
  26 static int my_id;
  27
  28 struct string_list *__ignored_macros = NULL;
  29 static int in_warn_on_macro()
  30 {
  31         struct statement *stmt;
  32         char *tmp;
  33         char *macro;
  34
  35         stmt = last_ptr_list((struct ptr_list *)big_statement_stack);
  36         macro = get_macro_name(stmt->pos);
  37         if (!macro)
  38                 return 0;
  39
  40         FOR_EACH_PTR(__ignored_macros, tmp) {
  41                 if (!strcmp(tmp, macro))
  42                         return 1;
  43         } END_FOR_EACH_PTR(tmp);
  44         return 0;
  45 }
  46
  47 struct sm_state *set_extra_mod(const char *name, struct symbol *sym, struct smatch_state *state)
  48 {
  49         if (in_warn_on_macro())
  50                 return NULL;
  51         remove_from_equiv(name, sym);
  52         return set_state(SMATCH_EXTRA, name, sym, state);
  53 }
  54
  55 struct sm_state *set_extra_expr_mod(struct expression *expr, struct smatch_state *state)
  56 {
  57         if (in_warn_on_macro())
  58                 return NULL;
  59         remove_from_equiv_expr(expr);
  60         return set_state_expr(SMATCH_EXTRA, expr, state);
  61 }
  62
  63 /*
  64  * This is for return_implies_state() hooks which modify a SMATCH_EXTRA state
  65  */
  66 void set_extra_expr_nomod(struct expression *expr, struct smatch_state *state)
  67 {
  68         struct relation *rel;
  69         struct smatch_state *orig_state;
  70
  71         orig_state = get_state_expr(SMATCH_EXTRA, expr);
  72
  73         if (!estate_related(orig_state)) {
  74                 set_state_expr(SMATCH_EXTRA, expr, state);
  75                 return;
  76         }
  77
  78         FOR_EACH_PTR(estate_related(orig_state), rel) {
  79                 if (option_debug_related)
  80                         sm_msg("updating related %s to %s", rel->name, state->name);
  81                 set_state(SMATCH_EXTRA, rel->name, rel->sym, state);
  82                 add_equiv(state, rel->name, rel->sym);
  83         } END_FOR_EACH_PTR(rel);
  84 }
  85
  86 static void set_extra_true_false(const char *name, struct symbol *sym,
  87                         struct smatch_state *true_state,
  88                         struct smatch_state *false_state)
  89 {
  90         struct relation *rel;
  91         struct smatch_state *orig_state;
  92
  93         if (in_warn_on_macro())
  94                 return;
  95
  96         orig_state = get_state(SMATCH_EXTRA, name, sym);
  97
  98         if (!estate_related(orig_state)) {
  99                 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
 100                 return;
 101         }
 102
 103         // FIXME!!!!  equiv => related
 104         FOR_EACH_PTR(estate_related(orig_state), rel) {
 105                 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
 106                                 true_state, false_state);
 107                 if (true_state)
 108                         add_equiv(true_state, rel->name, rel->sym);
 109                 if (false_state)
 110                         add_equiv(false_state, rel->name, rel->sym);
 111         } END_FOR_EACH_PTR(rel);
 112 }
 113
 114 static void set_extra_expr_true_false(struct expression *expr,
 115                 struct smatch_state *true_state,
 116                 struct smatch_state *false_state)
 117 {
 118         char *name;
 119         struct symbol *sym;
 120
 121         expr = strip_expr(expr);
 122         name = get_variable_from_expr(expr, &sym);
 123         if (!name || !sym)
 124                 goto free;
 125         set_extra_true_false(name, sym, true_state, false_state);
 126 free:
 127         free_string(name);
 128 }
 129
 130 struct smatch_state *filter_range(struct smatch_state *orig,
 131                                  long long filter_min, long long filter_max)
 132 {
 133         struct range_list *rl;
 134
 135         if (!orig)
 136                 orig = extra_undefined();
 137
 138         rl = remove_range(estate_ranges(orig), filter_min, filter_max);
 139         return alloc_estate_range_list(rl);
 140 }
 141
 142 struct smatch_state *add_filter(struct smatch_state *orig, long long num)
 143 {
 144         return filter_range(orig, num, num);
 145 }
 146
 147 static struct smatch_state *merge_func(const char *name, struct symbol *sym,
 148                                        struct smatch_state *s1,
 149                                        struct smatch_state *s2)
 150 {
 151         struct smatch_state *tmp;
 152         struct range_list *value_ranges;
 153         struct relation *rel;
 154         struct relation *new;
 155
 156         value_ranges = range_list_union(estate_ranges(s1), estate_ranges(s2));
 157         tmp = alloc_estate_range_list(value_ranges);
 158         FOR_EACH_PTR(estate_related(s1), rel) {
 159                 new = get_common_relationship(s2, rel->op, rel->name, rel->sym);
 160                 if (new)
 161                         add_related(tmp, new->op, new->name, new->sym);
 162         } END_FOR_EACH_PTR(rel);
 163         return tmp;
 164 }
 165
 166 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
 167 {
 168         struct expression *iter_var;
 169         struct expression *condition;
 170         struct sm_state *sm;
 171         long long start;
 172
 173         condition = strip_expr(loop->iterator_pre_condition);
 174         if (!condition)
 175                 return NULL;
 176         if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
 177                 return NULL;
 178         if (condition->op != SPECIAL_DECREMENT)
 179                 return NULL;
 180
 181         iter_var = condition->unop;
 182         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 183         if (!sm)
 184                 return NULL;
 185         if (estate_min(sm->state) < 0)
 186                 return NULL;
 187         start = estate_max(sm->state);
 188         if  (start <= 0)
 189                 return NULL;
 190         if (start != whole_range.max)
 191                 start--;
 192
 193         if (condition->type == EXPR_PREOP)
 194                 set_extra_expr_mod(iter_var, alloc_estate_range(1, start));
 195         if (condition->type == EXPR_POSTOP)
 196                 set_extra_expr_mod(iter_var, alloc_estate_range(0, start));
 197         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 198 }
 199
 200 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
 201                                                 struct expression *condition)
 202 {
 203         struct expression *iter_var;
 204         struct sm_state *sm;
 205         long long start;
 206         long long end;
 207
 208         iter_var = iter_expr->unop;
 209         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 210         if (!sm)
 211                 return NULL;
 212         if (!estate_get_single_value(sm->state, &start))
 213                 return NULL;
 214         if (!get_implied_value(condition->right, &end))
 215                 end = whole_range.max;
 216         if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
 217                 return NULL;
 218
 219         switch (condition->op) {
 220         case SPECIAL_NOTEQUAL:
 221         case '<':
 222                 if (end != whole_range.max)
 223                         end--;
 224                 break;
 225         case SPECIAL_LTE:
 226                 break;
 227         default:
 228                 return NULL;
 229         }
 230         if (end < start)
 231                 return NULL;
 232         set_extra_expr_mod(iter_var, alloc_estate_range(start, end));
 233         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 234 }
 235
 236 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
 237                                                 struct expression *condition)
 238 {
 239         struct expression *iter_var;
 240         struct sm_state *sm;
 241         long long start;
 242         long long end;
 243
 244         iter_var = iter_expr->unop;
 245         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 246         if (!sm)
 247                 return NULL;
 248         if (!estate_get_single_value(sm->state, &start))
 249                 return NULL;
 250         if (!get_implied_value(condition->right, &end))
 251                 end = whole_range.max;
 252         if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
 253                 return NULL;
 254
 255         switch (condition->op) {
 256         case SPECIAL_NOTEQUAL:
 257         case '>':
 258                 if (end != whole_range.min)
 259                         end++;
 260                 break;
 261         case SPECIAL_GTE:
 262                 break;
 263         default:
 264                 return NULL;
 265         }
 266         if (end > start)
 267                 return NULL;
 268         set_extra_expr_mod(iter_var, alloc_estate_range(end, start));
 269         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 270 }
 271
 272 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
 273 {
 274         struct expression *iter_expr;
 275         struct expression *condition;
 276
 277         if (!loop->iterator_post_statement)
 278                 return NULL;
 279         if (loop->iterator_post_statement->type != STMT_EXPRESSION)
 280                 return NULL;
 281         iter_expr = loop->iterator_post_statement->expression;
 282         if (!loop->iterator_pre_condition)
 283                 return NULL;
 284         if (loop->iterator_pre_condition->type != EXPR_COMPARE)
 285                 return NULL;
 286         condition = loop->iterator_pre_condition;
 287
 288         if (iter_expr->op == SPECIAL_INCREMENT)
 289                 return handle_canonical_for_inc(iter_expr, condition);
 290         if (iter_expr->op == SPECIAL_DECREMENT)
 291                 return handle_canonical_for_dec(iter_expr, condition);
 292         return NULL;
 293 }
 294
 295 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct state_list **slist)
 296 {
 297         struct sm_state *ret;
 298
 299         __push_fake_cur_slist();
 300         if (!loop->iterator_post_statement)
 301                 ret = handle_canonical_while_count_down(loop);
 302         else
 303                 ret = handle_canonical_for_loops(loop);
 304         *slist = __pop_fake_cur_slist();
 305         return ret;
 306 }
 307
 308 int __iterator_unchanged(struct sm_state *sm)
 309 {
 310         if (!sm)
 311                 return 0;
 312         if (get_sm_state(my_id, sm->name, sm->sym) == sm)
 313                 return 1;
 314         return 0;
 315 }
 316
 317 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
 318 {
 319         long long after_value;
 320
 321         /* paranoid checking.  prolly not needed */
 322         condition = strip_expr(condition);
 323         if (!condition)
 324                 return;
 325         if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
 326                 return;
 327         if (condition->op != SPECIAL_DECREMENT)
 328                 return;
 329         after_value = estate_min(sm->state);
 330         after_value--;
 331         set_extra_mod(sm->name, sm->sym, alloc_estate(after_value));
 332 }
 333
 334 void __extra_pre_loop_hook_after(struct sm_state *sm,
 335                                 struct statement *iterator,
 336                                 struct expression *condition)
 337 {
 338         struct expression *iter_expr;
 339         char *name;
 340         struct symbol *sym;
 341         long long value;
 342         int left = 0;
 343         struct smatch_state *state;
 344         long long min, max;
 345
 346         if (!iterator) {
 347                 while_count_down_after(sm, condition);
 348                 return;
 349         }
 350
 351         iter_expr = iterator->expression;
 352
 353         if (condition->type != EXPR_COMPARE)
 354                 return;
 355         if (!get_value(condition->left, &value)) {
 356                 if (!get_value(condition->right, &value))
 357                         return;
 358                 left = 1;
 359         }
 360         if (left)
 361                 name = get_variable_from_expr(condition->left, &sym);
 362         else
 363                 name = get_variable_from_expr(condition->right, &sym);
 364         if (!name || !sym)
 365                 goto free;
 366         if (sym != sm->sym || strcmp(name, sm->name))
 367                 goto free;
 368         state = get_state(my_id, name, sym);
 369         min = estate_min(state);
 370         max = estate_max(state);
 371         if (iter_expr->op == SPECIAL_INCREMENT &&
 372                 min != whole_range.min &&
 373                 max == whole_range.max) {
 374                 set_extra_mod(name, sym, alloc_estate(min));
 375         } else if (min == whole_range.min && max != whole_range.max) {
 376                 set_extra_mod(name, sym, alloc_estate(max));
 377         }
 378 free:
 379         free_string(name);
 380         return;
 381 }
 382
 383 static struct smatch_state *unmatched_state(struct sm_state *sm)
 384 {
 385         return extra_undefined();
 386 }
 387
 388 static void match_function_call(struct expression *expr)
 389 {
 390         struct expression *arg;
 391         struct expression *tmp;
 392
 393         FOR_EACH_PTR(expr->args, arg) {
 394                 tmp = strip_expr(arg);
 395                 if (tmp->type == EXPR_PREOP && tmp->op == '&') {
 396                         remove_from_equiv_expr(tmp->unop);
 397                         set_state_expr(SMATCH_EXTRA, tmp->unop, extra_undefined());
 398                 }
 399         } END_FOR_EACH_PTR(arg);
 400 }
 401
 402 static void match_assign(struct expression *expr)
 403 {
 404         struct expression *left;
 405         struct expression *right;
 406         struct symbol *right_sym;
 407         char *right_name;
 408         struct symbol *sym;
 409         char *name;
 410         long long value;
 411         int known;
 412         long long min = whole_range.min;
 413         long long max = whole_range.max;
 414         long long tmp;
 415
 416         if (__is_condition_assign(expr))
 417                 return;
 418         left = strip_expr(expr->left);
 419         name = get_variable_from_expr(left, &sym);
 420         if (!name)
 421                 return;
 422         right = strip_parens(expr->right);
 423         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
 424                 right = strip_parens(right->left);
 425
 426         if (expr->op == '=' && right->type == EXPR_CALL)
 427                 return;  /* these are handled in match_call_assign() */
 428
 429         right_name = get_variable_from_expr(right, &right_sym);
 430         if (expr->op == '=' && right_name && right_sym) {
 431                 set_equiv(left, right);
 432                 goto free;
 433         }
 434
 435         known = get_implied_value(right, &value);
 436         switch (expr->op) {
 437         case '=': {
 438                 struct range_list *rl = NULL;
 439
 440                 if (get_implied_range_list(right, &rl)) {
 441                         set_extra_mod(name, sym, alloc_estate_range_list(rl));
 442                         goto free;
 443                 }
 444
 445                 if (expr_unsigned(right))
 446                         min = 0;
 447                 break;
 448         }
 449         case SPECIAL_ADD_ASSIGN:
 450                 if (get_implied_min(left, &tmp)) {
 451                         if (known)
 452                                 min = tmp + value;
 453                         else
 454                                 min = tmp;
 455                 }
 456                 if (!inside_loop() && known && get_implied_max(left, &tmp))
 457                                 max = tmp + value;
 458                 break;
 459         case SPECIAL_SUB_ASSIGN:
 460                 if (get_implied_max(left, &tmp)) {
 461                         if (known)
 462                                 max = tmp - value;
 463                         else
 464                                 max = tmp;
 465                 }
 466                 if (!inside_loop() && known && get_implied_min(left, &tmp))
 467                                 min = tmp - value;
 468                 break;
 469         }
 470         set_extra_mod(name, sym, alloc_estate_range(min, max));
 471 free:
 472         free_string(right_name);
 473         free_string(name);
 474 }
 475
 476 static void reset_struct_members(const char *name, struct symbol *sym, struct expression *expr, void *unused)
 477 {
 478         struct state_list *slist;
 479         struct sm_state *tmp;
 480         int len;
 481
 482         len = strlen(name);
 483         slist = get_all_states(SMATCH_EXTRA);
 484         FOR_EACH_PTR(slist, tmp) {
 485                 if (sym != tmp->sym)
 486                         continue;
 487                 if (tmp->name[0] == '*' && !strcmp(name, tmp->name + 1)) {
 488                         set_extra_mod(tmp->name, tmp->sym, extra_undefined());
 489                         continue;
 490                 }
 491                 if (strncmp(name, tmp->name, len))
 492                         continue;
 493                 if (tmp->name[len] != '-' && tmp->name[len] != '.')
 494                         continue;
 495                 set_extra_mod(tmp->name, tmp->sym, extra_undefined());
 496         } END_FOR_EACH_PTR(tmp);
 497 }
 498
 499 static struct smatch_state *increment_state(struct smatch_state *state)
 500 {
 501         long long min = estate_min(state);
 502         long long max = estate_max(state);
 503
 504         if (inside_loop())
 505                 max = whole_range.max;
 506
 507         if (min != whole_range.min)
 508                 min++;
 509         if (max != whole_range.max)
 510                 max++;
 511         return alloc_estate_range(min, max);
 512 }
 513
 514 static struct smatch_state *decrement_state(struct smatch_state *state)
 515 {
 516         long long min = estate_min(state);
 517         long long max = estate_max(state);
 518
 519         if (inside_loop())
 520                 min = whole_range.min;
 521
 522         if (min != whole_range.min)
 523                 min--;
 524         if (max != whole_range.max)
 525                 max--;
 526         return alloc_estate_range(min, max);
 527 }
 528
 529 static void unop_expr(struct expression *expr)
 530 {
 531         struct smatch_state *state;
 532
 533         if (expr->smatch_flags & Handled)
 534                 return;
 535
 536         switch (expr->op) {
 537         case SPECIAL_INCREMENT:
 538                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 539                 state = increment_state(state);
 540                 set_extra_expr_mod(expr->unop, state);
 541                 break;
 542         case SPECIAL_DECREMENT:
 543                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 544                 state = decrement_state(state);
 545                 set_extra_expr_mod(expr->unop, state);
 546                 break;
 547         default:
 548                 return;
 549         }
 550 }
 551
 552 static void delete_state_tracker(struct tracker *t)
 553 {
 554         remove_from_equiv(t->name, t->sym);
 555         delete_state(t->owner, t->name, t->sym);
 556 }
 557
 558 static void scoped_state_extra(const char *name, struct symbol *sym)
 559 {
 560         struct tracker *t;
 561
 562         t = alloc_tracker(SMATCH_EXTRA, name, sym);
 563         add_scope_hook((scope_hook *)&delete_state_tracker, t);
 564 }
 565
 566 static void match_declarations(struct symbol *sym)
 567 {
 568         const char *name;
 569
 570         if (sym->ident) {
 571                 name = sym->ident->name;
 572                 if (!sym->initializer) {
 573                         set_state(SMATCH_EXTRA, name, sym, extra_undefined());
 574                         scoped_state_extra(name, sym);
 575                 }
 576         }
 577 }
 578
 579 static void match_function_def(struct symbol *sym)
 580 {
 581         struct symbol *arg;
 582
 583         FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
 584                 if (!arg->ident)
 585                         continue;
 586                 set_state(my_id, arg->ident->name, arg, extra_undefined());
 587         } END_FOR_EACH_PTR(arg);
 588 }
 589
 590 static int match_func_comparison(struct expression *expr)
 591 {
 592         struct expression *left = strip_expr(expr->left);
 593         struct expression *right = strip_expr(expr->right);
 594         long long val;
 595
 596         if (left->type == EXPR_CALL) {
 597                 if (!get_implied_value(right, &val))
 598                         return 1;
 599                 function_comparison(expr->op, left, val, 1);
 600                 return 1;
 601         }
 602
 603         if (right->type == EXPR_CALL) {
 604                 if (!get_implied_value(left, &val))
 605                         return 1;
 606                 function_comparison(expr->op, right, val, 0);
 607                 return 1;
 608         }
 609
 610         return 0;
 611 }
 612
 613 static void match_comparison(struct expression *expr)
 614 {
 615         struct expression *left = strip_expr(expr->left);
 616         struct expression *right = strip_expr(expr->right);
 617         struct range_list *left_orig;
 618         struct range_list *left_true;
 619         struct range_list *left_false;
 620         struct range_list *right_orig;
 621         struct range_list *right_true;
 622         struct range_list *right_false;
 623         struct smatch_state *left_true_state;
 624         struct smatch_state *left_false_state;
 625         struct smatch_state *right_true_state;
 626         struct smatch_state *right_false_state;
 627         int left_postop = 0;
 628         int right_postop = 0;
 629
 630         if (match_func_comparison(expr))
 631                 return;
 632
 633         if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
 634                 if (left->type == EXPR_POSTOP) {
 635                         left->smatch_flags |= Handled;
 636                         left_postop = left->op;
 637                 }
 638                 left = strip_expr(left->unop);
 639         }
 640
 641         if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
 642                 if (right->type == EXPR_POSTOP) {
 643                         right->smatch_flags |= Handled;
 644                         right_postop = right->op;
 645                 }
 646                 right = strip_expr(right->unop);
 647         }
 648
 649         if (!get_implied_range_list(left, &left_orig))
 650                 left_orig = alloc_range_list(whole_range.min, whole_range.max);
 651         if (!get_implied_range_list(right, &right_orig))
 652                 right_orig = alloc_range_list(whole_range.min, whole_range.max);
 653
 654         left_true = clone_range_list(left_orig);
 655         left_false = clone_range_list(left_orig);
 656         right_true = clone_range_list(right_orig);
 657         right_false = clone_range_list(right_orig);
 658
 659         switch (expr->op) {
 660         case '<':
 661         case SPECIAL_UNSIGNED_LT:
 662                 if (rl_max(right_orig) != whole_range.max)
 663                         left_true = remove_range(left_orig, rl_max(right_orig), whole_range.max);
 664                 if (rl_min(right_orig) != whole_range.min)
 665                         left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
 666
 667                 if (rl_min(left_orig) != whole_range.min)
 668                         right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig));
 669                 if (rl_max(left_orig) != whole_range.max)
 670                         right_false = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
 671                 break;
 672         case SPECIAL_UNSIGNED_LTE:
 673         case SPECIAL_LTE:
 674                 if (rl_max(right_orig) != whole_range.max)
 675                         left_true = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
 676                 if (rl_min(right_orig) != whole_range.min)
 677                         left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig));
 678
 679                 if (rl_min(left_orig) != whole_range.min)
 680                         right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
 681                 if (rl_max(left_orig) != whole_range.max)
 682                         right_false = remove_range(right_orig, rl_max(left_orig), whole_range.max);
 683                 break;
 684         case SPECIAL_EQUAL:
 685                 if (rl_max(right_orig) != whole_range.max)
 686                         left_true = remove_range(left_true, rl_max(right_orig) + 1, whole_range.max);
 687                 if (rl_min(right_orig) != whole_range.min)
 688                         left_true = remove_range(left_true, whole_range.min, rl_min(right_orig) - 1);
 689                 if (rl_min(right_orig) == rl_max(right_orig))
 690                         left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 691
 692                 if (rl_max(left_orig) != whole_range.max)
 693                         right_true = remove_range(right_true, rl_max(left_orig) + 1, whole_range.max);
 694                 if (rl_min(left_orig) != whole_range.min)
 695                         right_true = remove_range(right_true, whole_range.min, rl_min(left_orig) - 1);
 696                 if (rl_min(left_orig) == rl_max(left_orig))
 697                         right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 698                 break;
 699         case SPECIAL_UNSIGNED_GTE:
 700         case SPECIAL_GTE:
 701                 if (rl_min(right_orig) != whole_range.min)
 702                         left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
 703                 if (rl_max(right_orig) != whole_range.max)
 704                         left_false = remove_range(left_orig, rl_max(right_orig), whole_range.max);
 705
 706                 if (rl_max(left_orig) != whole_range.max)
 707                         right_true = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
 708                 if (rl_min(left_orig) != whole_range.min)
 709                         right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig));
 710                 break;
 711         case '>':
 712         case SPECIAL_UNSIGNED_GT:
 713                 if (rl_min(right_orig) != whole_range.min)
 714                         left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig));
 715                 if (rl_max(right_orig) != whole_range.max)
 716                         left_false = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
 717
 718                 if (rl_max(left_orig) != whole_range.max)
 719                         right_true = remove_range(right_orig, rl_max(left_orig), whole_range.max);
 720                 if (rl_min(left_orig) != whole_range.min)
 721                         right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
 722                 break;
 723         case SPECIAL_NOTEQUAL:
 724                 if (rl_max(right_orig) != whole_range.max)
 725                         left_false = remove_range(left_false, rl_max(right_orig) + 1, whole_range.max);
 726                 if (rl_min(right_orig) != whole_range.min)
 727                         left_false = remove_range(left_false, whole_range.min, rl_min(right_orig) - 1);
 728                 if (rl_min(right_orig) == rl_max(right_orig))
 729                         left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 730
 731                 if (rl_max(left_orig) != whole_range.max)
 732                         right_false = remove_range(right_false, rl_max(left_orig) + 1, whole_range.max);
 733                 if (rl_min(left_orig) != whole_range.min)
 734                         right_false = remove_range(right_false, whole_range.min, rl_min(left_orig) - 1);
 735                 if (rl_min(left_orig) == rl_max(left_orig))
 736                         right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 737                 break;
 738         default:
 739                 return;
 740         }
 741
 742         left_true_state = alloc_estate_range_list(left_true);
 743         left_false_state = alloc_estate_range_list(left_false);
 744         right_true_state = alloc_estate_range_list(right_true);
 745         right_false_state = alloc_estate_range_list(right_false);
 746
 747         if (left_postop == SPECIAL_INCREMENT) {
 748                 left_true_state = increment_state(left_true_state);
 749                 left_false_state = increment_state(left_false_state);
 750         }
 751         if (left_postop == SPECIAL_DECREMENT) {
 752                 left_true_state = decrement_state(left_true_state);
 753                 left_false_state = decrement_state(left_false_state);
 754         }
 755         if (right_postop == SPECIAL_INCREMENT) {
 756                 right_true_state = increment_state(right_true_state);
 757                 right_false_state = increment_state(right_false_state);
 758         }
 759         if (right_postop == SPECIAL_DECREMENT) {
 760                 right_true_state = decrement_state(right_true_state);
 761                 right_false_state = decrement_state(right_false_state);
 762         }
 763
 764         set_extra_expr_true_false(left, left_true_state, left_false_state);
 765         set_extra_expr_true_false(right, right_true_state, right_false_state);
 766 }
 767
 768 /* this is actually hooked from smatch_implied.c...  it's hacky, yes */
 769 void __extra_match_condition(struct expression *expr)
 770 {
 771         struct symbol *sym;
 772         char *name;
 773         struct smatch_state *pre_state;
 774         struct smatch_state *true_state;
 775         struct smatch_state *false_state;
 776
 777         expr = strip_expr(expr);
 778         switch (expr->type) {
 779         case EXPR_CALL:
 780                 function_comparison(SPECIAL_NOTEQUAL, expr, 0, 1);
 781                 return;
 782         case EXPR_PREOP:
 783         case EXPR_SYMBOL:
 784         case EXPR_DEREF:
 785                 name = get_variable_from_expr(expr, &sym);
 786                 if (!name)
 787                         return;
 788                 pre_state = get_state(my_id, name, sym);
 789                 true_state = add_filter(pre_state, 0);
 790                 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
 791                         false_state = alloc_estate(0);
 792                 else
 793                         false_state = alloc_estate_empty();
 794                 set_extra_true_false(name, sym, true_state, false_state);
 795                 free_string(name);
 796                 return;
 797         case EXPR_COMPARE:
 798                 match_comparison(expr);
 799                 return;
 800         case EXPR_ASSIGNMENT:
 801                 __extra_match_condition(expr->left);
 802                 return;
 803         }
 804 }
 805
 806 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
 807 int implied_not_equal(struct expression *expr, long long val)
 808 {
 809         return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
 810 }
 811
 812 int get_implied_range_list(struct expression *expr, struct range_list **rl)
 813 {
 814         long long val;
 815         struct smatch_state *state;
 816         long long min;
 817         long long max;
 818
 819         *rl = NULL;
 820
 821         expr = strip_parens(expr);
 822         if (!expr)
 823                 return 0;
 824
 825         state = get_state_expr(my_id, expr);
 826         if (state) {
 827                 *rl = clone_range_list(estate_ranges(state));
 828                 return 1;
 829         }
 830
 831         if (expr->type == EXPR_CALL) {
 832                 *rl = db_return_vals(expr);
 833                 return !!*rl;
 834         }
 835
 836         if (get_implied_value(expr, &val)) {
 837                 add_range(rl, val, val);
 838                 return 1;
 839         }
 840
 841         if (expr->type == EXPR_BINOP && expr->op == '%') {
 842                 if (!get_implied_value(expr->right, &val))
 843                         return 0;
 844                 add_range(rl, 0, val - 1);
 845                 return 1;
 846         }
 847
 848         if (!get_implied_min(expr, &min))
 849                 return 0;
 850         if (!get_implied_max(expr, &max))
 851                 return 0;
 852
 853         *rl = alloc_range_list(min, max);
 854         return 1;
 855 }
 856
 857 int is_whole_range(struct smatch_state *state)
 858 {
 859         return is_whole_range_rl(estate_ranges(state));
 860 }
 861
 862 static void struct_member_callback(char *fn, int param, char *printed_name, struct smatch_state *state)
 863 {
 864         if (is_whole_range(state))
 865                 return;
 866         sm_msg("info: passes param_value '%s' %d '%s' %s", fn, param, printed_name, state->name);
 867 }
 868
 869 static void match_call_info(struct expression *expr)
 870 {
 871         struct range_list *rl = NULL;
 872         struct expression *arg;
 873         char *name;
 874         int i = 0;
 875
 876         name = get_fnptr_name(expr->fn);
 877         if (!name)
 878                 return;
 879
 880         FOR_EACH_PTR(expr->args, arg) {
 881                 if (get_implied_range_list(arg, &rl) && !is_whole_range_rl(rl)) {
 882                         sm_msg("info: passes param_value '%s' %d '$$' %s",
 883                                name, i, show_ranges(rl));
 884                 }
 885                 i++;
 886         } END_FOR_EACH_PTR(arg);
 887
 888         free_string(name);
 889 }
 890
 891 void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
 892 {
 893         struct range_list *rl = NULL;
 894         struct smatch_state *state;
 895         char fullname[256];
 896
 897         if (strncmp(key, "$$", 2))
 898                 return;
 899
 900         snprintf(fullname, 256, "%s%s", name, key + 2);
 901         get_value_ranges(value, &rl);
 902         char *tmp = show_ranges(rl);
 903         if (strcmp(tmp, value))
 904                 sm_msg("value = %s, ranges = %s", value, tmp);
 905         state = alloc_estate_range_list(rl);
 906         set_state(SMATCH_EXTRA, fullname, sym, state);
 907 }
 908
 909 static void match_call_assign(struct expression *expr)
 910 {
 911         struct expression *right;
 912         struct range_list *rl;
 913
 914         if (expr->op != '=')
 915                 return;
 916
 917         right = strip_parens(expr->right);
 918         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
 919                 right = strip_parens(right->left);
 920
 921         rl = db_return_vals(right);
 922         if (rl)
 923                 set_extra_expr_mod(expr->left, alloc_estate_range_list(rl));
 924         else
 925                 set_extra_expr_mod(expr->left, extra_undefined());
 926 }
 927
 928 void register_smatch_extra(int id)
 929 {
 930         my_id = id;
 931         add_merge_hook(my_id, &merge_func);
 932         add_unmatched_state_hook(my_id, &unmatched_state);
 933         add_hook(&unop_expr, OP_HOOK);
 934         add_hook(&match_function_def, FUNC_DEF_HOOK);
 935         add_hook(&match_assign, ASSIGNMENT_HOOK);
 936         add_hook(&match_call_assign, CALL_ASSIGNMENT_HOOK);
 937         add_hook(&match_declarations, DECLARATION_HOOK);
 938         if (option_info) {
 939                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 940                 add_member_info_callback(my_id, struct_member_callback);
 941         }
 942         add_definition_db_callback(set_param_value, PARAM_VALUE);
 943 }
 944
 945 void register_smatch_extra_late(int id)
 946 {
 947         add_hook(&match_function_call, FUNCTION_CALL_HOOK);
 948         set_default_modification_hook(SMATCH_EXTRA, reset_struct_members);
 949 }