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                 sm_msg("setting %s to %s", rel->name, state->name);
  80                 set_state(SMATCH_EXTRA, rel->name, rel->sym, state);
  81                 add_equiv(state, rel->name, rel->sym);
  82         } END_FOR_EACH_PTR(rel);
  83 }
  84
  85 static void set_extra_true_false(const char *name, struct symbol *sym,
  86                         struct smatch_state *true_state,
  87                         struct smatch_state *false_state)
  88 {
  89         struct relation *rel;
  90         struct smatch_state *orig_state;
  91
  92         if (in_warn_on_macro())
  93                 return;
  94
  95         orig_state = get_state(SMATCH_EXTRA, name, sym);
  96
  97         if (!estate_related(orig_state)) {
  98                 set_true_false_states(SMATCH_EXTRA, name, sym, true_state, false_state);
  99                 return;
 100         }
 101
 102         // FIXME!!!!  equiv => related
 103         FOR_EACH_PTR(estate_related(orig_state), rel) {
 104                 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
 105                                 true_state, false_state);
 106                 if (true_state)
 107                         add_equiv(true_state, rel->name, rel->sym);
 108                 if (false_state)
 109                         add_equiv(false_state, rel->name, rel->sym);
 110         } END_FOR_EACH_PTR(rel);
 111 }
 112
 113 static void set_extra_expr_true_false(struct expression *expr,
 114                 struct smatch_state *true_state,
 115                 struct smatch_state *false_state)
 116 {
 117         char *name;
 118         struct symbol *sym;
 119
 120         expr = strip_expr(expr);
 121         name = get_variable_from_expr(expr, &sym);
 122         if (!name || !sym)
 123                 goto free;
 124         set_extra_true_false(name, sym, true_state, false_state);
 125 free:
 126         free_string(name);
 127 }
 128
 129 struct smatch_state *filter_range(struct smatch_state *orig,
 130                                  long long filter_min, long long filter_max)
 131 {
 132         struct smatch_state *ret;
 133         struct data_info *ret_info;
 134
 135         if (!orig)
 136                 orig = extra_undefined();
 137         ret = alloc_estate_empty();
 138         ret_info = get_dinfo(ret);
 139         ret_info->value_ranges = remove_range(estate_ranges(orig), filter_min, filter_max);
 140         ret->name = show_ranges(ret_info->value_ranges);
 141         return ret;
 142 }
 143
 144 struct smatch_state *add_filter(struct smatch_state *orig, long long num)
 145 {
 146         return filter_range(orig, num, num);
 147 }
 148
 149 static struct smatch_state *merge_func(const char *name, struct symbol *sym,
 150                                        struct smatch_state *s1,
 151                                        struct smatch_state *s2)
 152 {
 153         struct data_info *info2 = get_dinfo(s2);
 154         struct data_info *ret_info;
 155         struct smatch_state *tmp;
 156         struct range_list *value_ranges;
 157         struct relation *rel;
 158         struct relation *new;
 159
 160         value_ranges = range_list_union(estate_ranges(s1), estate_ranges(s2));
 161         tmp = alloc_estate_empty();
 162         ret_info = get_dinfo(tmp);
 163         ret_info->value_ranges = value_ranges;
 164         tmp->name = show_ranges(ret_info->value_ranges);
 165         FOR_EACH_PTR(estate_related(s1), rel) {
 166                 new = get_common_relationship(info2, rel->op, rel->name, rel->sym);
 167                 if (new)
 168                         add_related(tmp, new->op, new->name, new->sym);
 169         } END_FOR_EACH_PTR(rel);
 170         return tmp;
 171 }
 172
 173 static struct sm_state *handle_canonical_while_count_down(struct statement *loop)
 174 {
 175         struct expression *iter_var;
 176         struct expression *condition;
 177         struct sm_state *sm;
 178         long long start;
 179
 180         condition = strip_expr(loop->iterator_pre_condition);
 181         if (!condition)
 182                 return NULL;
 183         if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
 184                 return NULL;
 185         if (condition->op != SPECIAL_DECREMENT)
 186                 return NULL;
 187
 188         iter_var = condition->unop;
 189         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 190         if (!sm)
 191                 return NULL;
 192         if (estate_min(sm->state) < 0)
 193                 return NULL;
 194         start = estate_max(sm->state);
 195         if  (start <= 0)
 196                 return NULL;
 197         if (start != whole_range.max)
 198                 start--;
 199
 200         if (condition->type == EXPR_PREOP)
 201                 set_extra_expr_mod(iter_var, alloc_estate_range(1, start));
 202         if (condition->type == EXPR_POSTOP)
 203                 set_extra_expr_mod(iter_var, alloc_estate_range(0, start));
 204         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 205 }
 206
 207 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
 208                                                 struct expression *condition)
 209 {
 210         struct expression *iter_var;
 211         struct sm_state *sm;
 212         long long start;
 213         long long end;
 214
 215         iter_var = iter_expr->unop;
 216         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 217         if (!sm)
 218                 return NULL;
 219         if (!get_single_value_from_dinfo(get_dinfo(sm->state), &start))
 220                 return NULL;
 221         if (!get_implied_value(condition->right, &end))
 222                 end = whole_range.max;
 223         if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
 224                 return NULL;
 225
 226         switch (condition->op) {
 227         case SPECIAL_NOTEQUAL:
 228         case '<':
 229                 if (end != whole_range.max)
 230                         end--;
 231                 break;
 232         case SPECIAL_LTE:
 233                 break;
 234         default:
 235                 return NULL;
 236         }
 237         if (end < start)
 238                 return NULL;
 239         set_extra_expr_mod(iter_var, alloc_estate_range(start, end));
 240         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 241 }
 242
 243 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
 244                                                 struct expression *condition)
 245 {
 246         struct expression *iter_var;
 247         struct sm_state *sm;
 248         long long start;
 249         long long end;
 250
 251         iter_var = iter_expr->unop;
 252         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 253         if (!sm)
 254                 return NULL;
 255         if (!get_single_value_from_dinfo(get_dinfo(sm->state), &start))
 256                 return NULL;
 257         if (!get_implied_value(condition->right, &end))
 258                 end = whole_range.max;
 259         if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
 260                 return NULL;
 261
 262         switch (condition->op) {
 263         case SPECIAL_NOTEQUAL:
 264         case '>':
 265                 if (end != whole_range.min)
 266                         end++;
 267                 break;
 268         case SPECIAL_GTE:
 269                 break;
 270         default:
 271                 return NULL;
 272         }
 273         if (end > start)
 274                 return NULL;
 275         set_extra_expr_mod(iter_var, alloc_estate_range(end, start));
 276         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 277 }
 278
 279 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
 280 {
 281         struct expression *iter_expr;
 282         struct expression *condition;
 283
 284         if (!loop->iterator_post_statement)
 285                 return NULL;
 286         if (loop->iterator_post_statement->type != STMT_EXPRESSION)
 287                 return NULL;
 288         iter_expr = loop->iterator_post_statement->expression;
 289         if (!loop->iterator_pre_condition)
 290                 return NULL;
 291         if (loop->iterator_pre_condition->type != EXPR_COMPARE)
 292                 return NULL;
 293         condition = loop->iterator_pre_condition;
 294
 295         if (iter_expr->op == SPECIAL_INCREMENT)
 296                 return handle_canonical_for_inc(iter_expr, condition);
 297         if (iter_expr->op == SPECIAL_DECREMENT)
 298                 return handle_canonical_for_dec(iter_expr, condition);
 299         return NULL;
 300 }
 301
 302 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct state_list **slist)
 303 {
 304         struct sm_state *ret;
 305
 306         __push_fake_cur_slist();
 307         if (!loop->iterator_post_statement)
 308                 ret = handle_canonical_while_count_down(loop);
 309         else
 310                 ret = handle_canonical_for_loops(loop);
 311         *slist = __pop_fake_cur_slist();
 312         return ret;
 313 }
 314
 315 int __iterator_unchanged(struct sm_state *sm)
 316 {
 317         if (!sm)
 318                 return 0;
 319         if (get_sm_state(my_id, sm->name, sm->sym) == sm)
 320                 return 1;
 321         return 0;
 322 }
 323
 324 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
 325 {
 326         long long after_value;
 327
 328         /* paranoid checking.  prolly not needed */
 329         condition = strip_expr(condition);
 330         if (!condition)
 331                 return;
 332         if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
 333                 return;
 334         if (condition->op != SPECIAL_DECREMENT)
 335                 return;
 336         after_value = estate_min(sm->state);
 337         after_value--;
 338         set_extra_mod(sm->name, sm->sym, alloc_estate(after_value));
 339 }
 340
 341 void __extra_pre_loop_hook_after(struct sm_state *sm,
 342                                 struct statement *iterator,
 343                                 struct expression *condition)
 344 {
 345         struct expression *iter_expr;
 346         char *name;
 347         struct symbol *sym;
 348         long long value;
 349         int left = 0;
 350         struct smatch_state *state;
 351         long long min, max;
 352
 353         if (!iterator) {
 354                 while_count_down_after(sm, condition);
 355                 return;
 356         }
 357
 358         iter_expr = iterator->expression;
 359
 360         if (condition->type != EXPR_COMPARE)
 361                 return;
 362         if (!get_value(condition->left, &value)) {
 363                 if (!get_value(condition->right, &value))
 364                         return;
 365                 left = 1;
 366         }
 367         if (left)
 368                 name = get_variable_from_expr(condition->left, &sym);
 369         else
 370                 name = get_variable_from_expr(condition->right, &sym);
 371         if (!name || !sym)
 372                 goto free;
 373         if (sym != sm->sym || strcmp(name, sm->name))
 374                 goto free;
 375         state = get_state(my_id, name, sym);
 376         min = estate_min(state);
 377         max = estate_max(state);
 378         if (iter_expr->op == SPECIAL_INCREMENT &&
 379                 min != whole_range.min &&
 380                 max == whole_range.max) {
 381                 set_extra_mod(name, sym, alloc_estate(min));
 382         } else if (min == whole_range.min && max != whole_range.max) {
 383                 set_extra_mod(name, sym, alloc_estate(max));
 384         }
 385 free:
 386         free_string(name);
 387         return;
 388 }
 389
 390 static struct smatch_state *unmatched_state(struct sm_state *sm)
 391 {
 392         return extra_undefined();
 393 }
 394
 395 static void match_function_call(struct expression *expr)
 396 {
 397         struct expression *tmp;
 398
 399         FOR_EACH_PTR(expr->args, tmp) {
 400                 if (tmp->type == EXPR_PREOP && tmp->op == '&') {
 401                         remove_from_equiv_expr(tmp->unop);
 402                         set_state_expr(SMATCH_EXTRA, tmp->unop, extra_undefined());
 403                 }
 404         } END_FOR_EACH_PTR(tmp);
 405 }
 406
 407 static void set_equiv(struct sm_state *right_sm, struct expression *left)
 408 {
 409         struct smatch_state *state;
 410         struct relation *rel;
 411         char *name;
 412         struct symbol *sym;
 413
 414         name = get_variable_from_expr(left, &sym);
 415         if (!name || !sym)
 416                 goto free;
 417
 418         remove_from_equiv(name, sym);
 419
 420         state = clone_estate(right_sm->state);
 421         if (!estate_related(state))
 422                 add_equiv(state, right_sm->name, right_sm->sym);
 423         add_equiv(state, name, sym);
 424
 425         FOR_EACH_PTR(estate_related(state), rel) {
 426                 struct sm_state *new_sm;
 427
 428                 new_sm = clone_sm(right_sm);
 429                 new_sm->name = rel->name;
 430                 new_sm->sym = rel->sym;
 431                 new_sm->state = state;
 432                 __set_sm(new_sm);
 433         } END_FOR_EACH_PTR(rel);
 434 free:
 435         free_string(name);
 436 }
 437
 438 static void match_assign(struct expression *expr)
 439 {
 440         struct expression *left;
 441         struct expression *right;
 442         struct sm_state *right_sm;
 443         struct symbol *right_sym;
 444         char *right_name;
 445         struct symbol *sym;
 446         char *name;
 447         long long value;
 448         int known;
 449         long long min = whole_range.min;
 450         long long max = whole_range.max;
 451         long long tmp;
 452
 453         if (__is_condition_assign(expr))
 454                 return;
 455         left = strip_expr(expr->left);
 456         name = get_variable_from_expr(left, &sym);
 457         if (!name)
 458                 return;
 459         right = strip_parens(expr->right);
 460         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
 461                 right = strip_parens(right->left);
 462
 463         if (expr->op == '=' && right->type == EXPR_CALL)
 464                 return;  /* these are handled in match_call_assign() */
 465
 466         right_name = get_variable_from_expr(right, &right_sym);
 467         if (expr->op == '=' && right_name && right_sym) {
 468                 right_sm = get_sm_state_expr(SMATCH_EXTRA, right);
 469                 if (!right_sm)
 470                         right_sm = set_state_expr(SMATCH_EXTRA, right, extra_undefined());
 471                 if (!right_sm)
 472                         goto free;
 473                 set_equiv(right_sm, left);
 474                 goto free;
 475         }
 476
 477         known = get_implied_value(right, &value);
 478         switch (expr->op) {
 479         case '=': {
 480                 struct range_list *rl = NULL;
 481
 482                 if (get_implied_range_list(right, &rl)) {
 483                         set_extra_mod(name, sym, alloc_estate_range_list(rl));
 484                         goto free;
 485                 }
 486
 487                 if (expr_unsigned(right))
 488                         min = 0;
 489                 break;
 490         }
 491         case SPECIAL_ADD_ASSIGN:
 492                 if (get_implied_min(left, &tmp)) {
 493                         if (known)
 494                                 min = tmp + value;
 495                         else
 496                                 min = tmp;
 497                 }
 498                 if (!inside_loop() && known && get_implied_max(left, &tmp))
 499                                 max = tmp + value;
 500                 break;
 501         case SPECIAL_SUB_ASSIGN:
 502                 if (get_implied_max(left, &tmp)) {
 503                         if (known)
 504                                 max = tmp - value;
 505                         else
 506                                 max = tmp;
 507                 }
 508                 if (!inside_loop() && known && get_implied_min(left, &tmp))
 509                                 min = tmp - value;
 510                 break;
 511         }
 512         set_extra_mod(name, sym, alloc_estate_range(min, max));
 513 free:
 514         free_string(right_name);
 515         free_string(name);
 516 }
 517
 518 static void reset_struct_members(const char *name, struct symbol *sym, struct expression *expr, void *unused)
 519 {
 520         struct state_list *slist;
 521         struct sm_state *tmp;
 522         int len;
 523
 524         len = strlen(name);
 525         slist = get_all_states(SMATCH_EXTRA);
 526         FOR_EACH_PTR(slist, tmp) {
 527                 if (sym != tmp->sym)
 528                         continue;
 529                 if (strncmp(name, tmp->name, len))
 530                         continue;
 531                 if (tmp->name[len] != '-' && tmp->name[len] != '.')
 532                         continue;
 533                 set_extra_mod(tmp->name, tmp->sym, extra_undefined());
 534         } END_FOR_EACH_PTR(tmp);
 535 }
 536
 537 static struct smatch_state *increment_state(struct smatch_state *state)
 538 {
 539         long long min = estate_min(state);
 540         long long max = estate_max(state);
 541
 542         if (inside_loop())
 543                 max = whole_range.max;
 544
 545         if (min != whole_range.min)
 546                 min++;
 547         if (max != whole_range.max)
 548                 max++;
 549         return alloc_estate_range(min, max);
 550 }
 551
 552 static struct smatch_state *decrement_state(struct smatch_state *state)
 553 {
 554         long long min = estate_min(state);
 555         long long max = estate_max(state);
 556
 557         if (inside_loop())
 558                 min = whole_range.min;
 559
 560         if (min != whole_range.min)
 561                 min--;
 562         if (max != whole_range.max)
 563                 max--;
 564         return alloc_estate_range(min, max);
 565 }
 566
 567 static void unop_expr(struct expression *expr)
 568 {
 569         struct smatch_state *state;
 570
 571         if (expr->smatch_flags & Handled)
 572                 return;
 573
 574         switch (expr->op) {
 575         case SPECIAL_INCREMENT:
 576                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 577                 state = increment_state(state);
 578                 set_extra_expr_mod(expr->unop, state);
 579                 break;
 580         case SPECIAL_DECREMENT:
 581                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 582                 state = decrement_state(state);
 583                 set_extra_expr_mod(expr->unop, state);
 584                 break;
 585         default:
 586                 return;
 587         }
 588 }
 589
 590 static void delete_state_tracker(struct tracker *t)
 591 {
 592         remove_from_equiv(t->name, t->sym);
 593         delete_state(t->owner, t->name, t->sym);
 594 }
 595
 596 static void scoped_state_extra(const char *name, struct symbol *sym)
 597 {
 598         struct tracker *t;
 599
 600         t = alloc_tracker(SMATCH_EXTRA, name, sym);
 601         add_scope_hook((scope_hook *)&delete_state_tracker, t);
 602 }
 603
 604 static void match_declarations(struct symbol *sym)
 605 {
 606         const char *name;
 607
 608         if (sym->ident) {
 609                 name = sym->ident->name;
 610                 if (!sym->initializer) {
 611                         set_state(SMATCH_EXTRA, name, sym, extra_undefined());
 612                         scoped_state_extra(name, sym);
 613                 }
 614         }
 615 }
 616
 617 static void match_function_def(struct symbol *sym)
 618 {
 619         struct symbol *arg;
 620
 621         FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
 622                 if (!arg->ident)
 623                         continue;
 624                 set_state(my_id, arg->ident->name, arg, extra_undefined());
 625         } END_FOR_EACH_PTR(arg);
 626 }
 627
 628 static int last_stmt_val(struct statement *stmt, long long *val)
 629 {
 630         struct expression *expr;
 631
 632         if (!stmt)
 633                 return 0;
 634
 635         stmt = last_ptr_list((struct ptr_list *)stmt->stmts);
 636         if (stmt->type != STMT_EXPRESSION)
 637                 return 0;
 638         expr = stmt->expression;
 639         return get_value(expr, val);
 640 }
 641
 642 static int match_func_comparison(struct expression *expr)
 643 {
 644         struct expression *left = strip_expr(expr->left);
 645         struct expression *right = strip_expr(expr->right);
 646         long long val;
 647
 648         if (left->type == EXPR_CALL) {
 649                 if (!get_implied_value(right, &val))
 650                         return 1;
 651                 function_comparison(expr->op, left, val, 1);
 652                 return 1;
 653         }
 654
 655         if (right->type == EXPR_CALL) {
 656                 if (!get_implied_value(left, &val))
 657                         return 1;
 658                 function_comparison(expr->op, right, val, 0);
 659                 return 1;
 660         }
 661
 662         return 0;
 663 }
 664
 665 static void match_comparison(struct expression *expr)
 666 {
 667         struct expression *left = strip_expr(expr->left);
 668         struct expression *right = strip_expr(expr->right);
 669         struct range_list *left_orig;
 670         struct range_list *left_true;
 671         struct range_list *left_false;
 672         struct range_list *right_orig;
 673         struct range_list *right_true;
 674         struct range_list *right_false;
 675         struct smatch_state *left_true_state;
 676         struct smatch_state *left_false_state;
 677         struct smatch_state *right_true_state;
 678         struct smatch_state *right_false_state;
 679         int left_postop = 0;
 680         int right_postop = 0;
 681
 682         if (match_func_comparison(expr))
 683                 return;
 684
 685         if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
 686                 if (left->type == EXPR_POSTOP) {
 687                         left->smatch_flags |= Handled;
 688                         left_postop = left->op;
 689                 }
 690                 left = strip_expr(left->unop);
 691         }
 692
 693         if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
 694                 if (right->type == EXPR_POSTOP) {
 695                         right->smatch_flags |= Handled;
 696                         right_postop = right->op;
 697                 }
 698                 right = strip_expr(right->unop);
 699         }
 700
 701         if (!get_implied_range_list(left, &left_orig))
 702                 left_orig = alloc_range_list(whole_range.min, whole_range.max);
 703         if (!get_implied_range_list(right, &right_orig))
 704                 right_orig = alloc_range_list(whole_range.min, whole_range.max);
 705
 706         left_true = clone_range_list(left_orig);
 707         left_false = clone_range_list(left_orig);
 708         right_true = clone_range_list(right_orig);
 709         right_false = clone_range_list(right_orig);
 710
 711         switch (expr->op) {
 712         case '<':
 713         case SPECIAL_UNSIGNED_LT:
 714                 if (rl_max(right_orig) != whole_range.max)
 715                         left_true = remove_range(left_orig, rl_max(right_orig), whole_range.max);
 716                 if (rl_min(right_orig) != whole_range.min)
 717                         left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
 718
 719                 if (rl_min(left_orig) != whole_range.min)
 720                         right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig));
 721                 if (rl_max(left_orig) != whole_range.max)
 722                         right_false = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
 723                 break;
 724         case SPECIAL_UNSIGNED_LTE:
 725         case SPECIAL_LTE:
 726                 if (rl_max(right_orig) != whole_range.max)
 727                         left_true = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
 728                 if (rl_min(right_orig) != whole_range.min)
 729                         left_false = remove_range(left_orig, whole_range.min, rl_min(right_orig));
 730
 731                 if (rl_min(left_orig) != whole_range.min)
 732                         right_true = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
 733                 if (rl_max(left_orig) != whole_range.max)
 734                         right_false = remove_range(right_orig, rl_max(left_orig), whole_range.max);
 735                 break;
 736         case SPECIAL_EQUAL:
 737                 if (rl_max(right_orig) != whole_range.max)
 738                         left_true = remove_range(left_true, rl_max(right_orig) + 1, whole_range.max);
 739                 if (rl_min(right_orig) != whole_range.min)
 740                         left_true = remove_range(left_true, whole_range.min, rl_min(right_orig) - 1);
 741                 if (rl_min(right_orig) == rl_max(right_orig))
 742                         left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 743
 744                 if (rl_max(left_orig) != whole_range.max)
 745                         right_true = remove_range(right_true, rl_max(left_orig) + 1, whole_range.max);
 746                 if (rl_min(left_orig) != whole_range.min)
 747                         right_true = remove_range(right_true, whole_range.min, rl_min(left_orig) - 1);
 748                 if (rl_min(left_orig) == rl_max(left_orig))
 749                         right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 750                 break;
 751         case SPECIAL_UNSIGNED_GTE:
 752         case SPECIAL_GTE:
 753                 if (rl_min(right_orig) != whole_range.min)
 754                         left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig) - 1);
 755                 if (rl_max(right_orig) != whole_range.max)
 756                         left_false = remove_range(left_orig, rl_max(right_orig), whole_range.max);
 757
 758                 if (rl_max(left_orig) != whole_range.max)
 759                         right_true = remove_range(right_orig, rl_max(left_orig) + 1, whole_range.max);
 760                 if (rl_min(left_orig) != whole_range.min)
 761                         right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig));
 762                 break;
 763         case '>':
 764         case SPECIAL_UNSIGNED_GT:
 765                 if (rl_min(right_orig) != whole_range.min)
 766                         left_true = remove_range(left_orig, whole_range.min, rl_min(right_orig));
 767                 if (rl_max(right_orig) != whole_range.max)
 768                         left_false = remove_range(left_orig, rl_max(right_orig) + 1, whole_range.max);
 769
 770                 if (rl_max(left_orig) != whole_range.max)
 771                         right_true = remove_range(right_orig, rl_max(left_orig), whole_range.max);
 772                 if (rl_min(left_orig) != whole_range.min)
 773                         right_false = remove_range(right_orig, whole_range.min, rl_min(left_orig) - 1);
 774                 break;
 775         case SPECIAL_NOTEQUAL:
 776                 if (rl_max(right_orig) != whole_range.max)
 777                         left_false = remove_range(left_false, rl_max(right_orig) + 1, whole_range.max);
 778                 if (rl_min(right_orig) != whole_range.min)
 779                         left_false = remove_range(left_false, whole_range.min, rl_min(right_orig) - 1);
 780                 if (rl_min(right_orig) == rl_max(right_orig))
 781                         left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 782
 783                 if (rl_max(left_orig) != whole_range.max)
 784                         right_false = remove_range(right_false, rl_max(left_orig) + 1, whole_range.max);
 785                 if (rl_min(left_orig) != whole_range.min)
 786                         right_false = remove_range(right_false, whole_range.min, rl_min(left_orig) - 1);
 787                 if (rl_min(left_orig) == rl_max(left_orig))
 788                         right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 789                 break;
 790         default:
 791                 return;
 792         }
 793
 794         left_true_state = alloc_estate_range_list(left_true);
 795         left_false_state = alloc_estate_range_list(left_false);
 796         right_true_state = alloc_estate_range_list(right_true);
 797         right_false_state = alloc_estate_range_list(right_false);
 798
 799         if (left_postop == SPECIAL_INCREMENT) {
 800                 left_true_state = increment_state(left_true_state);
 801                 left_false_state = increment_state(left_false_state);
 802         }
 803         if (left_postop == SPECIAL_DECREMENT) {
 804                 left_true_state = decrement_state(left_true_state);
 805                 left_false_state = decrement_state(left_false_state);
 806         }
 807         if (right_postop == SPECIAL_INCREMENT) {
 808                 right_true_state = increment_state(right_true_state);
 809                 right_false_state = increment_state(right_false_state);
 810         }
 811         if (right_postop == SPECIAL_DECREMENT) {
 812                 right_true_state = decrement_state(right_true_state);
 813                 right_false_state = decrement_state(right_false_state);
 814         }
 815
 816         set_extra_expr_true_false(left, left_true_state, left_false_state);
 817         set_extra_expr_true_false(right, right_true_state, right_false_state);
 818 }
 819
 820 /* this is actually hooked from smatch_implied.c...  it's hacky, yes */
 821 void __extra_match_condition(struct expression *expr)
 822 {
 823         struct symbol *sym;
 824         char *name;
 825         struct smatch_state *pre_state;
 826         struct smatch_state *true_state;
 827         struct smatch_state *false_state;
 828
 829         expr = strip_expr(expr);
 830         switch (expr->type) {
 831         case EXPR_CALL:
 832                 function_comparison(SPECIAL_NOTEQUAL, expr, 0, 1);
 833                 return;
 834         case EXPR_PREOP:
 835         case EXPR_SYMBOL:
 836         case EXPR_DEREF:
 837                 name = get_variable_from_expr(expr, &sym);
 838                 if (!name)
 839                         return;
 840                 pre_state = get_state(my_id, name, sym);
 841                 true_state = add_filter(pre_state, 0);
 842                 if (possibly_true(SPECIAL_EQUAL, expr, 0, 0))
 843                         false_state = alloc_estate(0);
 844                 else
 845                         false_state = alloc_estate_empty();
 846                 set_extra_true_false(name, sym, true_state, false_state);
 847                 free_string(name);
 848                 return;
 849         case EXPR_COMPARE:
 850                 match_comparison(expr);
 851                 return;
 852         case EXPR_ASSIGNMENT:
 853                 __extra_match_condition(expr->left);
 854                 return;
 855         }
 856 }
 857
 858 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
 859 int implied_not_equal(struct expression *expr, long long val)
 860 {
 861         return !possibly_false(SPECIAL_NOTEQUAL, expr, val, 1);
 862 }
 863
 864 int known_condition_true(struct expression *expr)
 865 {
 866         long long tmp;
 867         struct statement *stmt;
 868
 869         if (!expr)
 870                 return 0;
 871
 872         if (get_value(expr, &tmp) && tmp)
 873                 return 1;
 874
 875         expr = strip_expr(expr);
 876         switch (expr->type) {
 877         case EXPR_PREOP:
 878                 if (expr->op == '!') {
 879                         if (known_condition_false(expr->unop))
 880                                 return 1;
 881                         break;
 882                 }
 883                 stmt = get_expression_statement(expr);
 884                 if (last_stmt_val(stmt, &tmp) && tmp == 1)
 885                         return 1;
 886                 break;
 887         default:
 888                 break;
 889         }
 890         return 0;
 891 }
 892
 893 int known_condition_false(struct expression *expr)
 894 {
 895         long long tmp;
 896         struct statement *stmt;
 897
 898         if (!expr)
 899                 return 0;
 900
 901         if (is_zero(expr))
 902                 return 1;
 903
 904         switch (expr->type) {
 905         case EXPR_PREOP:
 906                 if (expr->op == '!') {
 907                         if (known_condition_true(expr->unop))
 908                                 return 1;
 909                         break;
 910                 }
 911                 stmt = get_expression_statement(expr);
 912                 if (last_stmt_val(stmt, &tmp) && tmp == 0)
 913                         return 1;
 914                 break;
 915         case EXPR_CALL:
 916                 if (sym_name_is("__builtin_constant_p", expr->fn))
 917                         return 1;
 918                 break;
 919         default:
 920                 break;
 921         }
 922         return 0;
 923 }
 924
 925 struct range_list *get_range_list(struct expression *expr)
 926 {
 927         long long min;
 928         long long max;
 929         struct range_list *ret = NULL;
 930         struct smatch_state *state;
 931
 932         state = get_state_expr(SMATCH_EXTRA, expr);
 933         if (state)
 934                 return clone_range_list(estate_ranges(state));
 935         if (!get_absolute_min(expr, &min))
 936                 return NULL;
 937         if (!get_absolute_max(expr, &max))
 938                 return NULL;
 939         add_range(&ret, min, max);
 940         return ret;
 941 }
 942
 943 static int do_comparison(struct expression *expr)
 944 {
 945         struct range_list *left_ranges;
 946         struct range_list *right_ranges;
 947         int poss_true, poss_false;
 948
 949         left_ranges = get_range_list(expr->left);
 950         right_ranges = get_range_list(expr->right);
 951
 952         poss_true = possibly_true_range_lists(left_ranges, expr->op, right_ranges);
 953         poss_false = possibly_false_range_lists(left_ranges, expr->op, right_ranges);
 954
 955         free_range_list(&left_ranges);
 956         free_range_list(&right_ranges);
 957
 958         if (!poss_true && !poss_false)
 959                 return 0;
 960         if (poss_true && !poss_false)
 961                 return 1;
 962         if (!poss_true && poss_false)
 963                 return 2;
 964         return 3;
 965 }
 966
 967 int implied_condition_true(struct expression *expr)
 968 {
 969         struct statement *stmt;
 970         long long tmp;
 971         long long val;
 972
 973         if (!expr)
 974                 return 0;
 975
 976         if (get_implied_value(expr, &tmp) && tmp)
 977                 return 1;
 978
 979         if (expr->type == EXPR_POSTOP)
 980                 return implied_condition_true(expr->unop);
 981
 982         if (expr->type == EXPR_PREOP && expr->op == SPECIAL_DECREMENT)
 983                 return implied_not_equal(expr->unop, 1);
 984         if (expr->type == EXPR_PREOP && expr->op == SPECIAL_INCREMENT)
 985                 return implied_not_equal(expr->unop, -1);
 986
 987         expr = strip_expr(expr);
 988         switch (expr->type) {
 989         case EXPR_COMPARE:
 990                 if (do_comparison(expr) == 1)
 991                         return 1;
 992                 break;
 993         case EXPR_PREOP:
 994                 if (expr->op == '!') {
 995                         if (implied_condition_false(expr->unop))
 996                                 return 1;
 997                         break;
 998                 }
 999                 stmt = get_expression_statement(expr);
1000                 if (last_stmt_val(stmt, &val) && val == 1)
1001                         return 1;
1002                 break;
1003         default:
1004                 if (implied_not_equal(expr, 0) == 1)
1005                         return 1;
1006                 break;
1007         }
1008         return 0;
1009 }
1010
1011 int implied_condition_false(struct expression *expr)
1012 {
1013         struct statement *stmt;
1014         struct expression *tmp;
1015         long long val;
1016
1017         if (!expr)
1018                 return 0;
1019
1020         if (is_zero(expr))
1021                 return 1;
1022
1023         switch (expr->type) {
1024         case EXPR_COMPARE:
1025                 if (do_comparison(expr) == 2)
1026                         return 1;
1027         case EXPR_PREOP:
1028                 if (expr->op == '!') {
1029                         if (implied_condition_true(expr->unop))
1030                                 return 1;
1031                         break;
1032                 }
1033                 stmt = get_expression_statement(expr);
1034                 if (last_stmt_val(stmt, &val) && val == 0)
1035                         return 1;
1036                 tmp = strip_expr(expr);
1037                 if (tmp != expr)
1038                         return implied_condition_false(tmp);
1039                 break;
1040         default:
1041                 if (get_implied_value(expr, &val) && val == 0)
1042                         return 1;
1043                 break;
1044         }
1045         return 0;
1046 }
1047
1048 int get_implied_range_list(struct expression *expr, struct range_list **rl)
1049 {
1050         long long val;
1051         struct smatch_state *state;
1052         long long min;
1053         long long max;
1054
1055         expr = strip_parens(expr);
1056         if (!expr)
1057                 return 0;
1058
1059         state = get_state_expr(my_id, expr);
1060         if (state) {
1061                 *rl = clone_range_list(estate_ranges(state));
1062                 return 1;
1063         }
1064
1065         if (get_implied_value(expr, &val)) {
1066                 *rl = NULL;
1067                 add_range(rl, val, val);
1068                 return 1;
1069         }
1070
1071         if (expr->type != EXPR_BINOP)
1072                 return 0;
1073
1074         if (expr->type == EXPR_CALL) {
1075                 *rl = db_return_vals(expr);
1076                 return !!*rl;
1077         }
1078
1079         if (expr->op == '%') {
1080                 if (!get_implied_value(expr->right, &val))
1081                         return 0;
1082                 *rl = NULL;
1083                 add_range(rl, 0, val - 1);
1084                 return 1;
1085         }
1086
1087         if (!get_implied_min(expr, &min))
1088                 return 0;
1089         if (!get_implied_max(expr, &max))
1090                 return 0;
1091
1092         *rl = alloc_range_list(min, max);
1093         return 1;
1094 }
1095
1096 int is_whole_range(struct smatch_state *state)
1097 {
1098         struct data_range *drange;
1099
1100         if (!estate_ranges(state))
1101                 return 1;
1102         drange = first_ptr_list((struct ptr_list *)estate_ranges(state));
1103         if (drange->min == whole_range.min && drange->max == whole_range.max)
1104                 return 1;
1105         return 0;
1106 }
1107
1108 static void struct_member_callback(char *fn, int param, char *printed_name, struct smatch_state *state)
1109 {
1110         if (is_whole_range(state))
1111                 return;
1112         sm_msg("info: passes param_value '%s' %d '%s' %s", fn, param, printed_name, state->name);
1113 }
1114
1115 static void match_call_info(struct expression *expr)
1116 {
1117         struct range_list *rl = NULL;
1118         struct expression *arg;
1119         char *name;
1120         int i = 0;
1121
1122         name = get_fnptr_name(expr->fn);
1123         if (!name)
1124                 return;
1125
1126         FOR_EACH_PTR(expr->args, arg) {
1127                 if (get_implied_range_list(arg, &rl) && !is_whole_range_rl(rl)) {
1128                         sm_msg("info: passes param_value '%s' %d '$$' %s",
1129                                name, i, show_ranges(rl));
1130                 }
1131                 i++;
1132         } END_FOR_EACH_PTR(arg);
1133
1134         free_string(name);
1135 }
1136
1137 void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
1138 {
1139         struct range_list *rl = NULL;
1140         struct smatch_state *state;
1141         char fullname[256];
1142
1143         if (strncmp(key, "$$", 2))
1144                 return;
1145
1146         snprintf(fullname, 256, "%s%s", name, key + 2);
1147         get_value_ranges(value, &rl);
1148         char *tmp = show_ranges(rl);
1149         if (strcmp(tmp, value))
1150                 sm_msg("value = %s, ranges = %s", value, tmp);
1151         state = alloc_estate_range_list(rl);
1152         set_state(SMATCH_EXTRA, fullname, sym, state);
1153 }
1154
1155 static void match_call_assign(struct expression *expr)
1156 {
1157         struct expression *right;
1158         struct range_list *rl;
1159
1160         if (expr->op != '=')
1161                 return;
1162
1163         right = strip_parens(expr->right);
1164         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
1165                 right = strip_parens(right->left);
1166
1167         rl = db_return_vals(right);
1168         if (rl)
1169                 set_extra_expr_mod(expr->left, alloc_estate_range_list(rl));
1170         else
1171                 set_extra_expr_mod(expr->left, extra_undefined());
1172 }
1173
1174 void register_smatch_extra(int id)
1175 {
1176         my_id = id;
1177         add_merge_hook(my_id, &merge_func);
1178         add_unmatched_state_hook(my_id, &unmatched_state);
1179         add_hook(&unop_expr, OP_HOOK);
1180         add_hook(&match_function_def, FUNC_DEF_HOOK);
1181         add_hook(&match_function_call, FUNCTION_CALL_HOOK);
1182         add_hook(&match_assign, ASSIGNMENT_HOOK);
1183         add_hook(&match_call_assign, CALL_ASSIGNMENT_HOOK);
1184         add_hook(&match_declarations, DECLARATION_HOOK);
1185         if (option_info) {
1186                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1187                 add_member_info_callback(my_id, struct_member_callback);
1188         }
1189         add_definition_db_callback(set_param_value, PARAM_VALUE);
1190 }
1191
1192 void register_smatch_extra_late(int id)
1193 {
1194         set_default_modification_hook(SMATCH_EXTRA, reset_struct_members);
1195 }