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 *tmp;
 391
 392         FOR_EACH_PTR(expr->args, tmp) {
 393                 if (tmp->type == EXPR_PREOP && tmp->op == '&') {
 394                         remove_from_equiv_expr(tmp->unop);
 395                         set_state_expr(SMATCH_EXTRA, tmp->unop, extra_undefined());
 396                 }
 397         } END_FOR_EACH_PTR(tmp);
 398 }
 399
 400 static void match_assign(struct expression *expr)
 401 {
 402         struct expression *left;
 403         struct expression *right;
 404         struct symbol *right_sym;
 405         char *right_name;
 406         struct symbol *sym;
 407         char *name;
 408         long long value;
 409         int known;
 410         long long min = whole_range.min;
 411         long long max = whole_range.max;
 412         long long tmp;
 413
 414         if (__is_condition_assign(expr))
 415                 return;
 416         left = strip_expr(expr->left);
 417         name = get_variable_from_expr(left, &sym);
 418         if (!name)
 419                 return;
 420         right = strip_parens(expr->right);
 421         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
 422                 right = strip_parens(right->left);
 423
 424         if (expr->op == '=' && right->type == EXPR_CALL)
 425                 return;  /* these are handled in match_call_assign() */
 426
 427         right_name = get_variable_from_expr(right, &right_sym);
 428         if (expr->op == '=' && right_name && right_sym) {
 429                 set_equiv(left, right);
 430                 goto free;
 431         }
 432
 433         known = get_implied_value(right, &value);
 434         switch (expr->op) {
 435         case '=': {
 436                 struct range_list *rl = NULL;
 437
 438                 if (get_implied_range_list(right, &rl)) {
 439                         set_extra_mod(name, sym, alloc_estate_range_list(rl));
 440                         goto free;
 441                 }
 442
 443                 if (expr_unsigned(right))
 444                         min = 0;
 445                 break;
 446         }
 447         case SPECIAL_ADD_ASSIGN:
 448                 if (get_implied_min(left, &tmp)) {
 449                         if (known)
 450                                 min = tmp + value;
 451                         else
 452                                 min = tmp;
 453                 }
 454                 if (!inside_loop() && known && get_implied_max(left, &tmp))
 455                                 max = tmp + value;
 456                 break;
 457         case SPECIAL_SUB_ASSIGN:
 458                 if (get_implied_max(left, &tmp)) {
 459                         if (known)
 460                                 max = tmp - value;
 461                         else
 462                                 max = tmp;
 463                 }
 464                 if (!inside_loop() && known && get_implied_min(left, &tmp))
 465                                 min = tmp - value;
 466                 break;
 467         }
 468         set_extra_mod(name, sym, alloc_estate_range(min, max));
 469 free:
 470         free_string(right_name);
 471         free_string(name);
 472 }
 473
 474 static void reset_struct_members(const char *name, struct symbol *sym, struct expression *expr, void *unused)
 475 {
 476         struct state_list *slist;
 477         struct sm_state *tmp;
 478         int len;
 479
 480         len = strlen(name);
 481         slist = get_all_states(SMATCH_EXTRA);
 482         FOR_EACH_PTR(slist, tmp) {
 483                 if (sym != tmp->sym)
 484                         continue;
 485                 if (strncmp(name, tmp->name, len))
 486                         continue;
 487                 if (tmp->name[len] != '-' && tmp->name[len] != '.')
 488                         continue;
 489                 set_extra_mod(tmp->name, tmp->sym, extra_undefined());
 490         } END_FOR_EACH_PTR(tmp);
 491 }
 492
 493 static struct smatch_state *increment_state(struct smatch_state *state)
 494 {
 495         long long min = estate_min(state);
 496         long long max = estate_max(state);
 497
 498         if (inside_loop())
 499                 max = whole_range.max;
 500
 501         if (min != whole_range.min)
 502                 min++;
 503         if (max != whole_range.max)
 504                 max++;
 505         return alloc_estate_range(min, max);
 506 }
 507
 508 static struct smatch_state *decrement_state(struct smatch_state *state)
 509 {
 510         long long min = estate_min(state);
 511         long long max = estate_max(state);
 512
 513         if (inside_loop())
 514                 min = whole_range.min;
 515
 516         if (min != whole_range.min)
 517                 min--;
 518         if (max != whole_range.max)
 519                 max--;
 520         return alloc_estate_range(min, max);
 521 }
 522
 523 static void unop_expr(struct expression *expr)
 524 {
 525         struct smatch_state *state;
 526
 527         if (expr->smatch_flags & Handled)
 528                 return;
 529
 530         switch (expr->op) {
 531         case SPECIAL_INCREMENT:
 532                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 533                 state = increment_state(state);
 534                 set_extra_expr_mod(expr->unop, state);
 535                 break;
 536         case SPECIAL_DECREMENT:
 537                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 538                 state = decrement_state(state);
 539                 set_extra_expr_mod(expr->unop, state);
 540                 break;
 541         default:
 542                 return;
 543         }
 544 }
 545
 546 static void delete_state_tracker(struct tracker *t)
 547 {
 548         remove_from_equiv(t->name, t->sym);
 549         delete_state(t->owner, t->name, t->sym);
 550 }
 551
 552 static void scoped_state_extra(const char *name, struct symbol *sym)
 553 {
 554         struct tracker *t;
 555
 556         t = alloc_tracker(SMATCH_EXTRA, name, sym);
 557         add_scope_hook((scope_hook *)&delete_state_tracker, t);
 558 }
 559
 560 static void match_declarations(struct symbol *sym)
 561 {
 562         const char *name;
 563
 564         if (sym->ident) {
 565                 name = sym->ident->name;
 566                 if (!sym->initializer) {
 567                         set_state(SMATCH_EXTRA, name, sym, extra_undefined());
 568                         scoped_state_extra(name, sym);
 569                 }
 570         }
 571 }
 572
 573 static void match_function_def(struct symbol *sym)
 574 {
 575         struct symbol *arg;
 576
 577         FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
 578                 if (!arg->ident)
 579                         continue;
 580                 set_state(my_id, arg->ident->name, arg, extra_undefined());
 581         } END_FOR_EACH_PTR(arg);
 582 }
 583
 584 static int last_stmt_val(struct statement *stmt, long long *val)
 585 {
 586         struct expression *expr;
 587
 588         if (!stmt)
 589                 return 0;
 590
 591         stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 592         if (stmt->type != STMT_EXPRESSION)
 593                 return 0;
 594         expr = stmt->expression;
 595         return get_value(expr, val);
 596 }
 597
 598 static int match_func_comparison(struct expression *expr)
 599 {
 600         struct expression *left = strip_expr(expr->left);
 601         struct expression *right = strip_expr(expr->right);
 602         long long val;
 603
 604         if (left->type == EXPR_CALL) {
 605                 if (!get_implied_value(right, &val))
 606                         return 1;
 607                 function_comparison(expr->op, left, val, 1);
 608                 return 1;
 609         }
 610
 611         if (right->type == EXPR_CALL) {
 612                 if (!get_implied_value(left, &val))
 613                         return 1;
 614                 function_comparison(expr->op, right, val, 0);
 615                 return 1;
 616         }
 617
 618         return 0;
 619 }
 620
 621 static void match_comparison(struct expression *expr)
 622 {
 623         struct expression *left = strip_expr(expr->left);
 624         struct expression *right = strip_expr(expr->right);
 625         struct range_list *left_orig;
 626         struct range_list *left_true;
 627         struct range_list *left_false;
 628         struct range_list *right_orig;
 629         struct range_list *right_true;
 630         struct range_list *right_false;
 631         struct smatch_state *left_true_state;
 632         struct smatch_state *left_false_state;
 633         struct smatch_state *right_true_state;
 634         struct smatch_state *right_false_state;
 635         int left_postop = 0;
 636         int right_postop = 0;
 637
 638         if (match_func_comparison(expr))
 639                 return;
 640
 641         if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
 642                 if (left->type == EXPR_POSTOP) {
 643                         left->smatch_flags |= Handled;
 644                         left_postop = left->op;
 645                 }
 646                 left = strip_expr(left->unop);
 647         }
 648
 649         if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
 650                 if (right->type == EXPR_POSTOP) {
 651                         right->smatch_flags |= Handled;
 652                         right_postop = right->op;
 653                 }
 654                 right = strip_expr(right->unop);
 655         }
 656
 657         if (!get_implied_range_list(left, &left_orig))
 658                 left_orig = alloc_range_list(whole_range.min, whole_range.max);
 659         if (!get_implied_range_list(right, &right_orig))
 660                 right_orig = alloc_range_list(whole_range.min, whole_range.max);
 661
 662         left_true = clone_range_list(left_orig);
 663         left_false = clone_range_list(left_orig);
 664         right_true = clone_range_list(right_orig);
 665         right_false = clone_range_list(right_orig);
 666
 667         switch (expr->op) {
 668         case '<':
 669         case SPECIAL_UNSIGNED_LT:
 670                 if (rl_max(right_orig) != whole_range.max)
 671                         left_true = remove_range(left_orig, rl_max(right_orig), whole_range.max);
 672                 if (rl_min(right_orig) != whole_range.min)
 673                         left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
 674
 675                 if (rl_min(left_orig) != whole_range.min)
 676                         right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig));
 677                 if (rl_max(left_orig) != whole_range.max)
 678                         right_false = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
 679                 break;
 680         case SPECIAL_UNSIGNED_LTE:
 681         case SPECIAL_LTE:
 682                 if (rl_max(right_orig) != whole_range.max)
 683                         left_true = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
 684                 if (rl_min(right_orig) != whole_range.min)
 685                         left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig));
 686
 687                 if (rl_min(left_orig) != whole_range.min)
 688                         right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
 689                 if (rl_max(left_orig) != whole_range.max)
 690                         right_false = remove_range(right_orig, rl_max(left_orig), whole_range.max);
 691                 break;
 692         case SPECIAL_EQUAL:
 693                 if (rl_max(right_orig) != whole_range.max)
 694                         left_true = remove_range(left_true, rl_max(right_orig) + 1, whole_range.max);
 695                 if (rl_min(right_orig) != whole_range.min)
 696                         left_true = remove_range(left_true, whole_range.min, rl_min(right_orig) - 1);
 697                 if (rl_min(right_orig) == rl_max(right_orig))
 698                         left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 699
 700                 if (rl_max(left_orig) != whole_range.max)
 701                         right_true = remove_range(right_true, rl_max(left_orig) + 1, whole_range.max);
 702                 if (rl_min(left_orig) != whole_range.min)
 703                         right_true = remove_range(right_true, whole_range.min, rl_min(left_orig) - 1);
 704                 if (rl_min(left_orig) == rl_max(left_orig))
 705                         right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 706                 break;
 707         case SPECIAL_UNSIGNED_GTE:
 708         case SPECIAL_GTE:
 709                 if (rl_min(right_orig) != whole_range.min)
 710                         left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
 711                 if (rl_max(right_orig) != whole_range.max)
 712                         left_false = remove_range(left_orig, rl_max(right_orig), whole_range.max);
 713
 714                 if (rl_max(left_orig) != whole_range.max)
 715                         right_true = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
 716                 if (rl_min(left_orig) != whole_range.min)
 717                         right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig));
 718                 break;
 719         case '>':
 720         case SPECIAL_UNSIGNED_GT:
 721                 if (rl_min(right_orig) != whole_range.min)
 722                         left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig));
 723                 if (rl_max(right_orig) != whole_range.max)
 724                         left_false = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
 725
 726                 if (rl_max(left_orig) != whole_range.max)
 727                         right_true = remove_range(right_orig, rl_max(left_orig), whole_range.max);
 728                 if (rl_min(left_orig) != whole_range.min)
 729                         right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
 730                 break;
 731         case SPECIAL_NOTEQUAL:
 732                 if (rl_max(right_orig) != whole_range.max)
 733                         left_false = remove_range(left_false, rl_max(right_orig) + 1, whole_range.max);
 734                 if (rl_min(right_orig) != whole_range.min)
 735                         left_false = remove_range(left_false, whole_range.min, rl_min(right_orig) - 1);
 736                 if (rl_min(right_orig) == rl_max(right_orig))
 737                         left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 738
 739                 if (rl_max(left_orig) != whole_range.max)
 740                         right_false = remove_range(right_false, rl_max(left_orig) + 1, whole_range.max);
 741                 if (rl_min(left_orig) != whole_range.min)
 742                         right_false = remove_range(right_false, whole_range.min, rl_min(left_orig) - 1);
 743                 if (rl_min(left_orig) == rl_max(left_orig))
 744                         right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 745                 break;
 746         default:
 747                 return;
 748         }
 749
 750         left_true_state = alloc_estate_range_list(left_true);
 751         left_false_state = alloc_estate_range_list(left_false);
 752         right_true_state = alloc_estate_range_list(right_true);
 753         right_false_state = alloc_estate_range_list(right_false);
 754
 755         if (left_postop == SPECIAL_INCREMENT) {
 756                 left_true_state = increment_state(left_true_state);
 757                 left_false_state = increment_state(left_false_state);
 758         }
 759         if (left_postop == SPECIAL_DECREMENT) {
 760                 left_true_state = decrement_state(left_true_state);
 761                 left_false_state = decrement_state(left_false_state);
 762         }
 763         if (right_postop == SPECIAL_INCREMENT) {
 764                 right_true_state = increment_state(right_true_state);
 765                 right_false_state = increment_state(right_false_state);
 766         }
 767         if (right_postop == SPECIAL_DECREMENT) {
 768                 right_true_state = decrement_state(right_true_state);
 769                 right_false_state = decrement_state(right_false_state);
 770         }
 771
 772         set_extra_expr_true_false(left, left_true_state, left_false_state);
 773         set_extra_expr_true_false(right, right_true_state, right_false_state);
 774 }
 775
 776 /* this is actually hooked from smatch_implied.c...  it's hacky, yes */
 777 void __extra_match_condition(struct expression *expr)
 778 {
 779         struct symbol *sym;
 780         char *name;
 781         struct smatch_state *pre_state;
 782         struct smatch_state *true_state;
 783         struct smatch_state *false_state;
 784
 785         expr = strip_expr(expr);
 786         switch (expr->type) {
 787         case EXPR_CALL:
 788                 function_comparison(SPECIAL_NOTEQUAL, expr, 0, 1);
 789                 return;
 790         case EXPR_PREOP:
 791         case EXPR_SYMBOL:
 792         case EXPR_DEREF:
 793                 name = get_variable_from_expr(expr, &sym);
 794                 if (!name)
 795                         return;
 796                 pre_state = get_state(my_id, name, sym);
 797                 true_state = add_filter(pre_state, 0);
 798                 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
 799                         false_state = alloc_estate(0);
 800                 else
 801                         false_state = alloc_estate_empty();
 802                 set_extra_true_false(name, sym, true_state, false_state);
 803                 free_string(name);
 804                 return;
 805         case EXPR_COMPARE:
 806                 match_comparison(expr);
 807                 return;
 808         case EXPR_ASSIGNMENT:
 809                 __extra_match_condition(expr->left);
 810                 return;
 811         }
 812 }
 813
 814 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
 815 int implied_not_equal(struct expression *expr, long long val)
 816 {
 817         return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
 818 }
 819
 820 int known_condition_true(struct expression *expr)
 821 {
 822         long long tmp;
 823         struct statement *stmt;
 824
 825         if (!expr)
 826                 return 0;
 827
 828         if (get_value(expr, &tmp) && tmp)
 829                 return 1;
 830
 831         expr = strip_expr(expr);
 832         switch (expr->type) {
 833         case EXPR_PREOP:
 834                 if (expr->op == '!') {
 835                         if (known_condition_false(expr->unop))
 836                                 return 1;
 837                         break;
 838                 }
 839                 stmt = get_expression_statement(expr);
 840                 if (last_stmt_val(stmt, &tmp) && tmp == 1)
 841                         return 1;
 842                 break;
 843         default:
 844                 break;
 845         }
 846         return 0;
 847 }
 848
 849 int known_condition_false(struct expression *expr)
 850 {
 851         long long tmp;
 852         struct statement *stmt;
 853
 854         if (!expr)
 855                 return 0;
 856
 857         if (is_zero(expr))
 858                 return 1;
 859
 860         switch (expr->type) {
 861         case EXPR_PREOP:
 862                 if (expr->op == '!') {
 863                         if (known_condition_true(expr->unop))
 864                                 return 1;
 865                         break;
 866                 }
 867                 stmt = get_expression_statement(expr);
 868                 if (last_stmt_val(stmt, &tmp) && tmp == 0)
 869                         return 1;
 870                 break;
 871         case EXPR_CALL:
 872                 if (sym_name_is("__builtin_constant_p", expr->fn))
 873                         return 1;
 874                 break;
 875         default:
 876                 break;
 877         }
 878         return 0;
 879 }
 880
 881 static int do_comparison(struct expression *expr)
 882 {
 883         struct range_list *left_ranges = NULL;
 884         struct range_list *right_ranges = NULL;
 885         int poss_true, poss_false;
 886
 887         get_implied_range_list(expr->left, &left_ranges);
 888         get_implied_range_list(expr->right, &right_ranges);
 889
 890         poss_true = possibly_true_range_lists(left_ranges, expr->op, right_ranges);
 891         poss_false = possibly_false_range_lists(left_ranges, expr->op, right_ranges);
 892
 893         free_range_list(&left_ranges);
 894         free_range_list(&right_ranges);
 895
 896         if (!poss_true && !poss_false)
 897                 return 0;
 898         if (poss_true && !poss_false)
 899                 return 1;
 900         if (!poss_true && poss_false)
 901                 return 2;
 902         return 3;
 903 }
 904
 905 int implied_condition_true(struct expression *expr)
 906 {
 907         struct statement *stmt;
 908         long long tmp;
 909         long long val;
 910
 911         if (!expr)
 912                 return 0;
 913
 914         if (get_implied_value(expr, &tmp) && tmp)
 915                 return 1;
 916
 917         if (expr->type == EXPR_POSTOP)
 918                 return implied_condition_true(expr->unop);
 919
 920         if (expr->type == EXPR_PREOP && expr->op == SPECIAL_DECREMENT)
 921                 return implied_not_equal(expr->unop, 1);
 922         if (expr->type == EXPR_PREOP && expr->op == SPECIAL_INCREMENT)
 923                 return implied_not_equal(expr->unop, -1);
 924
 925         expr = strip_expr(expr);
 926         switch (expr->type) {
 927         case EXPR_COMPARE:
 928                 if (do_comparison(expr) == 1)
 929                         return 1;
 930                 break;
 931         case EXPR_PREOP:
 932                 if (expr->op == '!') {
 933                         if (implied_condition_false(expr->unop))
 934                                 return 1;
 935                         break;
 936                 }
 937                 stmt = get_expression_statement(expr);
 938                 if (last_stmt_val(stmt, &val) && val == 1)
 939                         return 1;
 940                 break;
 941         default:
 942                 if (implied_not_equal(expr, 0) == 1)
 943                         return 1;
 944                 break;
 945         }
 946         return 0;
 947 }
 948
 949 int implied_condition_false(struct expression *expr)
 950 {
 951         struct statement *stmt;
 952         struct expression *tmp;
 953         long long val;
 954
 955         if (!expr)
 956                 return 0;
 957
 958         if (is_zero(expr))
 959                 return 1;
 960
 961         switch (expr->type) {
 962         case EXPR_COMPARE:
 963                 if (do_comparison(expr) == 2)
 964                         return 1;
 965         case EXPR_PREOP:
 966                 if (expr->op == '!') {
 967                         if (implied_condition_true(expr->unop))
 968                                 return 1;
 969                         break;
 970                 }
 971                 stmt = get_expression_statement(expr);
 972                 if (last_stmt_val(stmt, &val) && val == 0)
 973                         return 1;
 974                 tmp = strip_expr(expr);
 975                 if (tmp != expr)
 976                         return implied_condition_false(tmp);
 977                 break;
 978         default:
 979                 if (get_implied_value(expr, &val) && val == 0)
 980                         return 1;
 981                 break;
 982         }
 983         return 0;
 984 }
 985
 986 int get_implied_range_list(struct expression *expr, struct range_list **rl)
 987 {
 988         long long val;
 989         struct smatch_state *state;
 990         long long min;
 991         long long max;
 992
 993         expr = strip_parens(expr);
 994         if (!expr)
 995                 return 0;
 996
 997         state = get_state_expr(my_id, expr);
 998         if (state) {
 999                 *rl = clone_range_list(estate_ranges(state));
1000                 return 1;
1001         }
1002
1003         if (get_implied_value(expr, &val)) {
1004                 *rl = NULL;
1005                 add_range(rl, val, val);
1006                 return 1;
1007         }
1008
1009         if (expr->type != EXPR_BINOP)
1010                 return 0;
1011
1012         if (expr->type == EXPR_CALL) {
1013                 *rl = db_return_vals(expr);
1014                 return !!*rl;
1015         }
1016
1017         if (expr->op == '%') {
1018                 if (!get_implied_value(expr->right, &val))
1019                         return 0;
1020                 *rl = NULL;
1021                 add_range(rl, 0, val - 1);
1022                 return 1;
1023         }
1024
1025         if (!get_implied_min(expr, &min))
1026                 return 0;
1027         if (!get_implied_max(expr, &max))
1028                 return 0;
1029
1030         *rl = alloc_range_list(min, max);
1031         return 1;
1032 }
1033
1034 int is_whole_range(struct smatch_state *state)
1035 {
1036         return is_whole_range_rl(estate_ranges(state));
1037 }
1038
1039 static void struct_member_callback(char *fn, int param, char *printed_name, struct smatch_state *state)
1040 {
1041         if (is_whole_range(state))
1042                 return;
1043         sm_msg("info: passes param_value '%s' %d '%s' %s", fn, param, printed_name, state->name);
1044 }
1045
1046 static void match_call_info(struct expression *expr)
1047 {
1048         struct range_list *rl = NULL;
1049         struct expression *arg;
1050         char *name;
1051         int i = 0;
1052
1053         name = get_fnptr_name(expr->fn);
1054         if (!name)
1055                 return;
1056
1057         FOR_EACH_PTR(expr->args, arg) {
1058                 if (get_implied_range_list(arg, &rl) && !is_whole_range_rl(rl)) {
1059                         sm_msg("info: passes param_value '%s' %d '$$' %s",
1060                                name, i, show_ranges(rl));
1061                 }
1062                 i++;
1063         } END_FOR_EACH_PTR(arg);
1064
1065         free_string(name);
1066 }
1067
1068 void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
1069 {
1070         struct range_list *rl = NULL;
1071         struct smatch_state *state;
1072         char fullname[256];
1073
1074         if (strncmp(key, "$$", 2))
1075                 return;
1076
1077         snprintf(fullname, 256, "%s%s", name, key + 2);
1078         get_value_ranges(value, &rl);
1079         char *tmp = show_ranges(rl);
1080         if (strcmp(tmp, value))
1081                 sm_msg("value = %s, ranges = %s", value, tmp);
1082         state = alloc_estate_range_list(rl);
1083         set_state(SMATCH_EXTRA, fullname, sym, state);
1084 }
1085
1086 static void match_call_assign(struct expression *expr)
1087 {
1088         struct expression *right;
1089         struct range_list *rl;
1090
1091         if (expr->op != '=')
1092                 return;
1093
1094         right = strip_parens(expr->right);
1095         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
1096                 right = strip_parens(right->left);
1097
1098         rl = db_return_vals(right);
1099         if (rl)
1100                 set_extra_expr_mod(expr->left, alloc_estate_range_list(rl));
1101         else
1102                 set_extra_expr_mod(expr->left, extra_undefined());
1103 }
1104
1105 void register_smatch_extra(int id)
1106 {
1107         my_id = id;
1108         add_merge_hook(my_id, &merge_func);
1109         add_unmatched_state_hook(my_id, &unmatched_state);
1110         add_hook(&unop_expr, OP_HOOK);
1111         add_hook(&match_function_def, FUNC_DEF_HOOK);
1112         add_hook(&match_function_call, FUNCTION_CALL_HOOK);
1113         add_hook(&match_assign, ASSIGNMENT_HOOK);
1114         add_hook(&match_call_assign, CALL_ASSIGNMENT_HOOK);
1115         add_hook(&match_declarations, DECLARATION_HOOK);
1116         if (option_info) {
1117                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1118                 add_member_info_callback(my_id, struct_member_callback);
1119         }
1120         add_definition_db_callback(set_param_value, PARAM_VALUE);
1121 }
1122
1123 void register_smatch_extra_late(int id)
1124 {
1125         set_default_modification_hook(SMATCH_EXTRA, reset_struct_members);
1126 }