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 = get_current_statement();
  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         set_related(state, estate_related(orig_state));
  79         FOR_EACH_PTR(estate_related(orig_state), rel) {
  80                 if (option_debug_related)
  81                         sm_msg("updating related %s to %s", rel->name, state->name);
  82                 set_state(SMATCH_EXTRA, rel->name, rel->sym, state);
  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         if (true_state)
 104                 set_related(true_state, estate_related(orig_state));
 105         if (false_state)
 106                 set_related(false_state, estate_related(orig_state));
 107
 108         FOR_EACH_PTR(estate_related(orig_state), rel) {
 109                 set_true_false_states(SMATCH_EXTRA, rel->name, rel->sym,
 110                                 true_state, false_state);
 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                                  sval_t filter_min, sval_t filter_max)
 132 {
 133         struct range_list *rl;
 134
 135         if (!orig)
 136                 orig = extra_undefined(filter_min.type);
 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, sval_t sval)
 143 {
 144         return filter_range(orig, sval, sval);
 145 }
 146
 147 static struct smatch_state *merge_func(struct smatch_state *s1, struct smatch_state *s2)
 148 {
 149         struct smatch_state *tmp;
 150         struct range_list *value_ranges;
 151         struct related_list *rlist;
 152
 153         if (estates_equiv(s1, s2))
 154                 return s1;
 155
 156         value_ranges = range_list_union(estate_ranges(s1), estate_ranges(s2));
 157         tmp = alloc_estate_range_list(value_ranges);
 158         rlist = get_shared_relations(estate_related(s1), estate_related(s2));
 159         set_related(tmp, rlist);
 160         if (estate_has_hard_max(s1) && estate_has_hard_max(s2))
 161                 estate_set_hard_max(tmp);
 162
 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         struct smatch_state *estate;
 172         sval_t start;
 173
 174         condition = strip_expr(loop->iterator_pre_condition);
 175         if (!condition)
 176                 return NULL;
 177         if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
 178                 return NULL;
 179         if (condition->op != SPECIAL_DECREMENT)
 180                 return NULL;
 181
 182         iter_var = condition->unop;
 183         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 184         if (!sm)
 185                 return NULL;
 186         if (sval_cmp_val(estate_min(sm->state), 0) < 0)
 187                 return NULL;
 188         start = estate_max(sm->state);
 189         if  (sval_cmp_val(start, 0) <= 0)
 190                 return NULL;
 191         if (!sval_is_max(start))
 192                 start.value--;
 193
 194         if (condition->type == EXPR_PREOP) {
 195                 estate = alloc_estate_range(sval_type_val(start.type, 1), start);
 196                 if (estate_has_hard_max(sm->state))
 197                         estate_set_hard_max(estate);
 198                 set_extra_expr_mod(iter_var, estate);
 199         }
 200         if (condition->type == EXPR_POSTOP) {
 201                 estate = alloc_estate_range(sval_type_val(start.type, 0), start);
 202                 if (estate_has_hard_max(sm->state))
 203                         estate_set_hard_max(estate);
 204                 set_extra_expr_mod(iter_var, estate);
 205         }
 206         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 207 }
 208
 209 static struct sm_state *handle_canonical_for_inc(struct expression *iter_expr,
 210                                                 struct expression *condition)
 211 {
 212         struct expression *iter_var;
 213         struct sm_state *sm;
 214         struct smatch_state *estate;
 215         sval_t start, end, dummy;
 216
 217         iter_var = iter_expr->unop;
 218         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 219         if (!sm)
 220                 return NULL;
 221         if (!estate_get_single_value(sm->state, &start))
 222                 return NULL;
 223         if (!get_implied_value(condition->right, &end))
 224                 end = sval_type_max(get_type(iter_var));
 225
 226         if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
 227                 return NULL;
 228
 229         switch (condition->op) {
 230         case SPECIAL_NOTEQUAL:
 231         case '<':
 232                 if (!sval_is_min(end))
 233                         end.value--;
 234                 break;
 235         case SPECIAL_LTE:
 236                 break;
 237         default:
 238                 return NULL;
 239         }
 240         if (sval_cmp(end, start) < 0)
 241                 return NULL;
 242         estate = alloc_estate_range(start, end);
 243         if (get_hard_max(condition->right, &dummy))
 244                 estate_set_hard_max(estate);
 245         set_extra_expr_mod(iter_var, estate);
 246         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 247 }
 248
 249 static struct sm_state *handle_canonical_for_dec(struct expression *iter_expr,
 250                                                 struct expression *condition)
 251 {
 252         struct expression *iter_var;
 253         struct sm_state *sm;
 254         struct smatch_state *estate;
 255         sval_t start, end;
 256
 257         iter_var = iter_expr->unop;
 258         sm = get_sm_state_expr(SMATCH_EXTRA, iter_var);
 259         if (!sm)
 260                 return NULL;
 261         if (!estate_get_single_value(sm->state, &start))
 262                 return NULL;
 263         if (!get_implied_value(condition->right, &end))
 264                 end = sval_type_min(get_type(iter_var));
 265         if (get_sm_state_expr(SMATCH_EXTRA, condition->left) != sm)
 266                 return NULL;
 267
 268         switch (condition->op) {
 269         case SPECIAL_NOTEQUAL:
 270         case '>':
 271                 if (!sval_is_min(end) && !sval_is_max(end))
 272                         end.value++;
 273                 break;
 274         case SPECIAL_GTE:
 275                 break;
 276         default:
 277                 return NULL;
 278         }
 279         if (sval_cmp(end, start) > 0)
 280                 return NULL;
 281         estate = alloc_estate_range(end, start);
 282         estate_set_hard_max(estate);
 283         set_extra_expr_mod(iter_var, estate);
 284         return get_sm_state_expr(SMATCH_EXTRA, iter_var);
 285 }
 286
 287 static struct sm_state *handle_canonical_for_loops(struct statement *loop)
 288 {
 289         struct expression *iter_expr;
 290         struct expression *condition;
 291
 292         if (!loop->iterator_post_statement)
 293                 return NULL;
 294         if (loop->iterator_post_statement->type != STMT_EXPRESSION)
 295                 return NULL;
 296         iter_expr = loop->iterator_post_statement->expression;
 297         if (!loop->iterator_pre_condition)
 298                 return NULL;
 299         if (loop->iterator_pre_condition->type != EXPR_COMPARE)
 300                 return NULL;
 301         condition = loop->iterator_pre_condition;
 302
 303         if (iter_expr->op == SPECIAL_INCREMENT)
 304                 return handle_canonical_for_inc(iter_expr, condition);
 305         if (iter_expr->op == SPECIAL_DECREMENT)
 306                 return handle_canonical_for_dec(iter_expr, condition);
 307         return NULL;
 308 }
 309
 310 struct sm_state *__extra_handle_canonical_loops(struct statement *loop, struct state_list **slist)
 311 {
 312         struct sm_state *ret;
 313
 314         __push_fake_cur_slist();
 315         if (!loop->iterator_post_statement)
 316                 ret = handle_canonical_while_count_down(loop);
 317         else
 318                 ret = handle_canonical_for_loops(loop);
 319         *slist = __pop_fake_cur_slist();
 320         return ret;
 321 }
 322
 323 int __iterator_unchanged(struct sm_state *sm)
 324 {
 325         if (!sm)
 326                 return 0;
 327         if (get_sm_state(my_id, sm->name, sm->sym) == sm)
 328                 return 1;
 329         return 0;
 330 }
 331
 332 static void while_count_down_after(struct sm_state *sm, struct expression *condition)
 333 {
 334         sval_t after_value;
 335
 336         /* paranoid checking.  prolly not needed */
 337         condition = strip_expr(condition);
 338         if (!condition)
 339                 return;
 340         if (condition->type != EXPR_PREOP && condition->type != EXPR_POSTOP)
 341                 return;
 342         if (condition->op != SPECIAL_DECREMENT)
 343                 return;
 344         after_value = estate_min(sm->state);
 345         after_value.value--;
 346         set_extra_mod(sm->name, sm->sym, alloc_estate(after_value));
 347 }
 348
 349 void __extra_pre_loop_hook_after(struct sm_state *sm,
 350                                 struct statement *iterator,
 351                                 struct expression *condition)
 352 {
 353         struct expression *iter_expr;
 354         sval_t limit;
 355
 356         if (!iterator) {
 357                 while_count_down_after(sm, condition);
 358                 return;
 359         }
 360
 361         iter_expr = iterator->expression;
 362
 363         if (condition->type != EXPR_COMPARE)
 364                 return;
 365         if (iter_expr->op == SPECIAL_INCREMENT) {
 366                 limit = sval_binop(estate_max(sm->state), '+',
 367                                    sval_type_val(estate_type(sm->state), 1));
 368         } else {
 369                 limit = sval_binop(estate_min(sm->state), '-',
 370                                    sval_type_val(estate_type(sm->state), 1));
 371         }
 372         set_extra_mod(sm->name, sm->sym, alloc_estate(limit));
 373 }
 374
 375 static struct smatch_state *unmatched_state(struct sm_state *sm)
 376 {
 377         return extra_undefined(estate_type(sm->state));
 378 }
 379
 380 static void match_function_call(struct expression *expr)
 381 {
 382         struct expression *arg;
 383         struct expression *tmp;
 384
 385         FOR_EACH_PTR(expr->args, arg) {
 386                 tmp = strip_expr(arg);
 387                 if (tmp->type == EXPR_PREOP && tmp->op == '&') {
 388                         remove_from_equiv_expr(tmp->unop);
 389                         set_state_expr(SMATCH_EXTRA, tmp->unop, extra_undefined(get_type(tmp->unop)));
 390                 }
 391         } END_FOR_EACH_PTR(arg);
 392 }
 393
 394 static int types_equiv_or_pointer(struct symbol *one, struct symbol *two)
 395 {
 396         if (!one || !two)
 397                 return 0;
 398         if (one->type == SYM_PTR && two->type == SYM_PTR)
 399                 return 1;
 400         return types_equiv(one, two);
 401 }
 402
 403 static void match_assign(struct expression *expr)
 404 {
 405         struct range_list *rl = NULL;
 406         struct expression *left;
 407         struct expression *right;
 408         struct symbol *right_sym;
 409         char *right_name;
 410         struct symbol *sym;
 411         char *name;
 412         sval_t value;
 413         int known;
 414         sval_t right_min, right_max;
 415         sval_t tmp;
 416
 417         if (__is_condition_assign(expr))
 418                 return;
 419         left = strip_expr(expr->left);
 420         name = get_variable_from_expr(left, &sym);
 421         if (!name)
 422                 return;
 423         right = strip_parens(expr->right);
 424         while (right->type == EXPR_ASSIGNMENT && right->op == '=')
 425                 right = strip_parens(right->left);
 426
 427         if (expr->op == '=' && right->type == EXPR_CALL)
 428                 return;  /* these are handled in smatch_function_hooks.c */
 429
 430         right_name = get_variable_from_expr(right, &right_sym);
 431         if (expr->op == '=' && right_name && right_sym &&
 432             types_equiv_or_pointer(get_type(expr->left), get_type(expr->right))) {
 433                 set_equiv(left, right);
 434                 goto free;
 435         }
 436
 437         right_min = sval_type_min(get_type(expr->right));
 438         right_max = sval_type_max(get_type(expr->right));
 439
 440         known = get_implied_value(right, &value);
 441         switch (expr->op) {
 442         case '=': {
 443                 struct smatch_state *state;
 444
 445                 if (get_implied_range_list(right, &rl)) {
 446                         rl = cast_rl(get_type(expr->left), rl);
 447                         state = alloc_estate_range_list(rl);
 448                         if (get_hard_max(right, &tmp))
 449                                 estate_set_hard_max(state);
 450                 } else {
 451                         rl = whole_range_list(get_type(right));
 452                         rl = cast_rl(get_type(expr->left), rl);
 453                         state = alloc_estate_range_list(rl);
 454                 }
 455                 set_extra_mod(name, sym, state);
 456                 goto free;
 457         }
 458         case SPECIAL_ADD_ASSIGN:
 459                 if (get_implied_min(left, &tmp)) {
 460                         if (known)
 461                                 right_min = sval_binop(tmp, '+', value);
 462                         else
 463                                 right_min = tmp;
 464                 }
 465                 if (!inside_loop() && known && get_implied_max(left, &tmp))
 466                         right_max = sval_binop(tmp, '+', value);
 467                 break;
 468         case SPECIAL_SUB_ASSIGN:
 469                 if (get_implied_max(left, &tmp)) {
 470                         if (known)
 471                                 right_max = sval_binop(tmp, '-', value);
 472                         else
 473                                 right_max = tmp;
 474                 }
 475                 if (!inside_loop() && known && get_implied_min(left, &tmp))
 476                         right_min = sval_binop(tmp, '-', value);
 477                 break;
 478         }
 479         if (!sval_is_min(right_min) || !sval_is_max(right_max))
 480                 rl = cast_rl(get_type(expr->left), alloc_range_list(right_min, right_max));
 481         else
 482                 rl = whole_range_list(get_type(expr->left));
 483         set_extra_mod(name, sym, alloc_estate_range_list(rl));
 484 free:
 485         free_string(right_name);
 486         free_string(name);
 487 }
 488
 489 static void reset_struct_members(struct sm_state *sm)
 490 {
 491         set_extra_mod(sm->name, sm->sym, extra_undefined(estate_type(sm->state)));
 492 }
 493
 494 static struct smatch_state *increment_state(struct smatch_state *state)
 495 {
 496         sval_t min = estate_min(state);
 497         sval_t max = estate_max(state);
 498
 499         if (!estate_ranges(state))
 500                 return NULL;
 501
 502         if (inside_loop())
 503                 max = sval_type_max(max.type);
 504
 505         if (!sval_is_min(min) && !sval_is_max(min))
 506                 min.value++;
 507         if (!sval_is_min(max) && !sval_is_max(max))
 508                 max.value++;
 509         return alloc_estate_range(min, max);
 510 }
 511
 512 static struct smatch_state *decrement_state(struct smatch_state *state)
 513 {
 514         sval_t min = estate_min(state);
 515         sval_t max = estate_max(state);
 516
 517         if (!estate_ranges(state))
 518                 return NULL;
 519
 520         if (inside_loop())
 521                 min = sval_type_min(min.type);
 522
 523         if (!sval_is_min(min) && !sval_is_max(min))
 524                 min.value--;
 525         if (!sval_is_min(max) && !sval_is_max(max))
 526                 max.value--;
 527         return alloc_estate_range(min, max);
 528 }
 529
 530 static void unop_expr(struct expression *expr)
 531 {
 532         struct smatch_state *state;
 533
 534         if (expr->smatch_flags & Handled)
 535                 return;
 536
 537         switch (expr->op) {
 538         case SPECIAL_INCREMENT:
 539                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 540                 state = increment_state(state);
 541                 if (!state)
 542                         state = extra_undefined(get_type(expr));
 543                 set_extra_expr_mod(expr->unop, state);
 544                 break;
 545         case SPECIAL_DECREMENT:
 546                 state = get_state_expr(SMATCH_EXTRA, expr->unop);
 547                 state = decrement_state(state);
 548                 if (!state)
 549                         state = extra_undefined(get_type(expr));
 550                 set_extra_expr_mod(expr->unop, state);
 551                 break;
 552         default:
 553                 return;
 554         }
 555 }
 556
 557 static void asm_expr(struct statement *stmt)
 558 {
 559
 560         struct expression *expr;
 561         int state = 0;
 562
 563         FOR_EACH_PTR(stmt->asm_outputs, expr) {
 564                 switch (state) {
 565                 case 0: /* identifier */
 566                 case 1: /* constraint */
 567                         state++;
 568                         continue;
 569                 case 2: /* expression */
 570                         state = 0;
 571                         set_extra_expr_mod(expr, extra_undefined(get_type(expr)));
 572                         continue;
 573                 }
 574         } END_FOR_EACH_PTR(expr);
 575 }
 576
 577 static void delete_state_tracker(struct tracker *t)
 578 {
 579         remove_from_equiv(t->name, t->sym);
 580         delete_state(t->owner, t->name, t->sym);
 581 }
 582
 583 static void scoped_state_extra(const char *name, struct symbol *sym)
 584 {
 585         struct tracker *t;
 586
 587         t = alloc_tracker(SMATCH_EXTRA, name, sym);
 588         add_scope_hook((scope_hook *)&delete_state_tracker, t);
 589 }
 590
 591 static void match_declarations(struct symbol *sym)
 592 {
 593         const char *name;
 594
 595         if (sym->ident) {
 596                 name = sym->ident->name;
 597                 if (!sym->initializer) {
 598                         set_state(SMATCH_EXTRA, name, sym, extra_undefined(get_real_base_type(sym)));
 599                         scoped_state_extra(name, sym);
 600                 }
 601         }
 602 }
 603
 604 static void check_dereference(struct expression *expr)
 605 {
 606         set_extra_expr_nomod(expr, alloc_estate_range(valid_ptr_min_sval, valid_ptr_max_sval));
 607 }
 608
 609 static void match_dereferences(struct expression *expr)
 610 {
 611         if (expr->type != EXPR_PREOP)
 612                 return;
 613         check_dereference(expr->unop);
 614 }
 615
 616 static void match_pointer_as_array(struct expression *expr)
 617 {
 618         if (!is_array(expr))
 619                 return;
 620         check_dereference(expr->unop->left);
 621 }
 622
 623 static void set_param_dereferenced(struct expression *arg, char *unused)
 624 {
 625         check_dereference(arg);
 626 }
 627
 628 static void match_function_def(struct symbol *sym)
 629 {
 630         struct symbol *arg;
 631
 632         FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
 633                 if (!arg->ident)
 634                         continue;
 635                 set_state(my_id, arg->ident->name, arg, extra_undefined(get_real_base_type(arg)));
 636         } END_FOR_EACH_PTR(arg);
 637 }
 638
 639 static int match_func_comparison(struct expression *expr)
 640 {
 641         struct expression *left = strip_expr(expr->left);
 642         struct expression *right = strip_expr(expr->right);
 643         sval_t sval;
 644
 645         if (left->type == EXPR_CALL) {
 646                 if (!get_implied_value(right, &sval))
 647                         return 1;
 648                 function_comparison(expr->op, left, sval, 1);
 649                 return 1;
 650         }
 651
 652         if (right->type == EXPR_CALL) {
 653                 if (!get_implied_value(left, &sval))
 654                         return 1;
 655                 function_comparison(expr->op, right, sval, 0);
 656                 return 1;
 657         }
 658
 659         return 0;
 660 }
 661
 662 static sval_t add_one(sval_t sval)
 663 {
 664         sval.value++;
 665         return sval;
 666 }
 667
 668 static sval_t sub_one(sval_t sval)
 669 {
 670         sval.value--;
 671         return sval;
 672 }
 673
 674 static void match_comparison(struct expression *expr)
 675 {
 676         struct expression *left = strip_expr(expr->left);
 677         struct expression *right = strip_expr(expr->right);
 678         struct symbol *type;
 679         struct range_list *left_orig;
 680         struct range_list *left_true;
 681         struct range_list *left_false;
 682         struct range_list *right_orig;
 683         struct range_list *right_true;
 684         struct range_list *right_false;
 685         struct smatch_state *left_true_state;
 686         struct smatch_state *left_false_state;
 687         struct smatch_state *right_true_state;
 688         struct smatch_state *right_false_state;
 689         sval_t min, max, dummy;
 690         int left_postop = 0;
 691         int right_postop = 0;
 692
 693         if (match_func_comparison(expr))
 694                 return;
 695
 696         if (left->op == SPECIAL_INCREMENT || left->op == SPECIAL_DECREMENT) {
 697                 if (left->type == EXPR_POSTOP) {
 698                         left->smatch_flags |= Handled;
 699                         left_postop = left->op;
 700                 }
 701                 left = strip_expr(left->unop);
 702         }
 703         while (left->type == EXPR_ASSIGNMENT)
 704                 left = strip_expr(left->left);
 705
 706         if (right->op == SPECIAL_INCREMENT || right->op == SPECIAL_DECREMENT) {
 707                 if (right->type == EXPR_POSTOP) {
 708                         right->smatch_flags |= Handled;
 709                         right_postop = right->op;
 710                 }
 711                 right = strip_expr(right->unop);
 712         }
 713
 714         type = get_type(expr);
 715         if (!type)
 716                 type = &llong_ctype;
 717
 718         if (get_implied_range_list(left, &left_orig)) {
 719                 left_orig = cast_rl(type, left_orig);
 720         } else {
 721                 min = sval_type_min(get_type(left));
 722                 max = sval_type_max(get_type(left));
 723                 left_orig = cast_rl(type, alloc_range_list(min, max));
 724         }
 725
 726         if (get_implied_range_list(right, &right_orig)) {
 727                 right_orig = cast_rl(type, right_orig);
 728         } else {
 729                 min = sval_type_min(get_type(right));
 730                 max = sval_type_max(get_type(right));
 731                 right_orig = cast_rl(type, alloc_range_list(min, max));
 732         }
 733         min = sval_type_min(type);
 734         max = sval_type_max(type);
 735
 736         left_true = clone_range_list(left_orig);
 737         left_false = clone_range_list(left_orig);
 738         right_true = clone_range_list(right_orig);
 739         right_false = clone_range_list(right_orig);
 740
 741         switch (expr->op) {
 742         case '<':
 743         case SPECIAL_UNSIGNED_LT:
 744                 if (!sval_is_max(rl_max(right_orig))) {
 745                         left_true = remove_range(left_orig, rl_max(right_orig), max);
 746                 }
 747                 if (!sval_is_min(rl_min(right_orig))) {
 748                         left_false = remove_range(left_orig, min, sub_one(rl_min(right_orig)));
 749                 }
 750
 751                 if (!sval_is_min(rl_min(left_orig)))
 752                         right_true = remove_range(right_orig, min, rl_min(left_orig));
 753                 if (!sval_is_max(rl_max(left_orig)))
 754                         right_false = remove_range(right_orig, add_one(rl_max(left_orig)), max);
 755                 break;
 756         case SPECIAL_UNSIGNED_LTE:
 757         case SPECIAL_LTE:
 758                 if (!sval_is_max(rl_max(right_orig)))
 759                         left_true = remove_range(left_orig, add_one(rl_max(right_orig)), max);
 760                 if (!sval_is_min(rl_min(right_orig)))
 761                         left_false = remove_range(left_orig, min, rl_min(right_orig));
 762
 763                 if (!sval_is_min(rl_min(left_orig)))
 764                         right_true = remove_range(right_orig, min, sub_one(rl_min(left_orig)));
 765                 if (!sval_is_max(rl_max(left_orig)))
 766                         right_false = remove_range(right_orig, rl_max(left_orig), max);
 767
 768                 if (sval_cmp(rl_min(left_orig), rl_min(right_orig)) == 0)
 769                         left_false = remove_range(left_false, rl_min(left_orig), rl_min(left_orig));
 770                 if (sval_cmp(rl_max(left_orig), rl_max(right_orig)) == 0)
 771                         right_false = remove_range(right_false, rl_max(left_orig), rl_max(left_orig));
 772                 break;
 773         case SPECIAL_EQUAL:
 774                 if (!sval_is_max(rl_max(right_orig))) {
 775                         left_true = remove_range(left_true, add_one(rl_max(right_orig)), max);
 776                 }
 777                 if (!sval_is_min(rl_min(right_orig))) {
 778                         left_true = remove_range(left_true, min, sub_one(rl_min(right_orig)));
 779                 }
 780                 if (sval_cmp(rl_min(right_orig), rl_max(right_orig)) == 0)
 781                         left_false = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 782
 783                 if (!sval_is_max(rl_max(left_orig)))
 784                         right_true = remove_range(right_true, add_one(rl_max(left_orig)), max);
 785                 if (!sval_is_min(rl_min(left_orig)))
 786                         right_true = remove_range(right_true, min, sub_one(rl_min(left_orig)));
 787                 if (sval_cmp(rl_min(left_orig), rl_max(left_orig)) == 0)
 788                         right_false = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 789                 break;
 790         case SPECIAL_UNSIGNED_GTE:
 791         case SPECIAL_GTE:
 792                 if (!sval_is_min(rl_min(right_orig)))
 793                         left_true = remove_range(left_orig, min, sub_one(rl_min(right_orig)));
 794                 if (!sval_is_max(rl_max(right_orig)))
 795                         left_false = remove_range(left_orig, rl_max(right_orig), max);
 796
 797                 if (!sval_is_max(rl_max(left_orig)))
 798                         right_true = remove_range(right_orig, add_one(rl_max(left_orig)), max);
 799                 if (!sval_is_min(rl_min(left_orig)))
 800                         right_false = remove_range(right_orig, min, rl_min(left_orig));
 801
 802                 if (sval_cmp(rl_min(left_orig), rl_min(right_orig)) == 0)
 803                         right_false = remove_range(right_false, rl_min(left_orig), rl_min(left_orig));
 804                 if (sval_cmp(rl_max(left_orig), rl_max(right_orig)) == 0)
 805                         left_false = remove_range(left_false, rl_max(left_orig), rl_max(left_orig));
 806                 break;
 807         case '>':
 808         case SPECIAL_UNSIGNED_GT:
 809                 if (!sval_is_min(rl_min(right_orig)))
 810                         left_true = remove_range(left_orig, min, rl_min(right_orig));
 811                 if (!sval_is_max(rl_max(right_orig)))
 812                         left_false = remove_range(left_orig, add_one(rl_max(right_orig)), max);
 813
 814                 if (!sval_is_max(rl_max(left_orig)))
 815                         right_true = remove_range(right_orig, rl_max(left_orig), max);
 816                 if (!sval_is_min(rl_min(left_orig)))
 817                         right_false = remove_range(right_orig, min, sub_one(rl_min(left_orig)));
 818                 break;
 819         case SPECIAL_NOTEQUAL:
 820                 if (!sval_is_max(rl_max(right_orig)))
 821                         left_false = remove_range(left_false, add_one(rl_max(right_orig)), max);
 822                 if (!sval_is_min(rl_min(right_orig)))
 823                         left_false = remove_range(left_false, min, sub_one(rl_min(right_orig)));
 824                 if (sval_cmp(rl_min(right_orig), rl_max(right_orig)) == 0)
 825                         left_true = remove_range(left_orig, rl_min(right_orig), rl_min(right_orig));
 826
 827                 if (!sval_is_max(rl_max(left_orig)))
 828                         right_false = remove_range(right_false, add_one(rl_max(left_orig)), max);
 829                 if (!sval_is_min(rl_min(left_orig)))
 830                         right_false = remove_range(right_false, min, sub_one(rl_min(left_orig)));
 831                 if (sval_cmp(rl_min(left_orig), rl_max(left_orig)) == 0)
 832                         right_true = remove_range(right_orig, rl_min(left_orig), rl_min(left_orig));
 833                 break;
 834         default:
 835                 return;
 836         }
 837
 838         left_true_state = alloc_estate_range_list(cast_rl(get_type(left), left_true));
 839         left_false_state = alloc_estate_range_list(cast_rl(get_type(left), left_false));
 840         right_true_state = alloc_estate_range_list(cast_rl(get_type(right), right_true));
 841         right_false_state = alloc_estate_range_list(cast_rl(get_type(right), right_false));
 842
 843         switch (expr->op) {
 844         case '<':
 845         case SPECIAL_UNSIGNED_LT:
 846         case SPECIAL_UNSIGNED_LTE:
 847         case SPECIAL_LTE:
 848                 if (get_hard_max(right, &dummy))
 849                         estate_set_hard_max(left_true_state);
 850                 if (get_hard_max(left, &dummy))
 851                         estate_set_hard_max(right_false_state);
 852                 break;
 853         case '>':
 854         case SPECIAL_UNSIGNED_GT:
 855         case SPECIAL_UNSIGNED_GTE:
 856         case SPECIAL_GTE:
 857                 if (get_hard_max(left, &dummy))
 858                         estate_set_hard_max(right_true_state);
 859                 if (get_hard_max(right, &dummy))
 860                         estate_set_hard_max(left_false_state);
 861                 break;
 862         }
 863
 864         if (get_hard_max(left, &dummy)) {
 865                 estate_set_hard_max(left_true_state);
 866                 estate_set_hard_max(left_false_state);
 867         }
 868         if (get_hard_max(right, &dummy)) {
 869                 estate_set_hard_max(right_true_state);
 870                 estate_set_hard_max(right_false_state);
 871         }
 872
 873         if (left_postop == SPECIAL_INCREMENT) {
 874                 left_true_state = increment_state(left_true_state);
 875                 left_false_state = increment_state(left_false_state);
 876         }
 877         if (left_postop == SPECIAL_DECREMENT) {
 878                 left_true_state = decrement_state(left_true_state);
 879                 left_false_state = decrement_state(left_false_state);
 880         }
 881         if (right_postop == SPECIAL_INCREMENT) {
 882                 right_true_state = increment_state(right_true_state);
 883                 right_false_state = increment_state(right_false_state);
 884         }
 885         if (right_postop == SPECIAL_DECREMENT) {
 886                 right_true_state = decrement_state(right_true_state);
 887                 right_false_state = decrement_state(right_false_state);
 888         }
 889
 890         set_extra_expr_true_false(left, left_true_state, left_false_state);
 891         set_extra_expr_true_false(right, right_true_state, right_false_state);
 892 }
 893
 894 /* this is actually hooked from smatch_implied.c...  it's hacky, yes */
 895 void __extra_match_condition(struct expression *expr)
 896 {
 897         struct symbol *sym;
 898         char *name;
 899         struct smatch_state *pre_state;
 900         struct smatch_state *true_state;
 901         struct smatch_state *false_state;
 902
 903         expr = strip_expr(expr);
 904         switch (expr->type) {
 905         case EXPR_CALL:
 906                 function_comparison(SPECIAL_NOTEQUAL, expr, ll_to_sval(0), 1);
 907                 return;
 908         case EXPR_PREOP:
 909         case EXPR_SYMBOL:
 910         case EXPR_DEREF: {
 911                 sval_t zero;
 912
 913                 zero = sval_blank(expr);
 914                 zero.value = 0;
 915
 916                 name = get_variable_from_expr(expr, &sym);
 917                 if (!name)
 918                         return;
 919                 pre_state = get_state(my_id, name, sym);
 920                 true_state = add_filter(pre_state, zero);
 921                 if (possibly_true(expr, SPECIAL_EQUAL, zero_expr()))
 922                         false_state = alloc_estate(zero);
 923                 else
 924                         false_state = alloc_estate_empty();
 925                 set_extra_true_false(name, sym, true_state, false_state);
 926                 free_string(name);
 927                 return;
 928         }
 929         case EXPR_COMPARE:
 930                 match_comparison(expr);
 931                 return;
 932         case EXPR_ASSIGNMENT:
 933                 __extra_match_condition(expr->left);
 934                 return;
 935         }
 936 }
 937
 938 /* returns 1 if it is not possible for expr to be value, otherwise returns 0 */
 939 int implied_not_equal(struct expression *expr, long long val)
 940 {
 941         return !possibly_false(expr, SPECIAL_NOTEQUAL, value_expr(val));
 942 }
 943
 944 int is_whole_range(struct smatch_state *state)
 945 {
 946         return is_whole_range_rl(estate_ranges(state));
 947 }
 948
 949 static void struct_member_callback(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state)
 950 {
 951         if (is_whole_range(state))
 952                 return;
 953         sm_msg("info: passes param_value '%s' %d '%s' %s %s", fn, param, printed_name, state->name, global_static);
 954 }
 955
 956 static void match_call_info(struct expression *expr)
 957 {
 958         struct range_list *rl = NULL;
 959         struct expression *arg;
 960         struct symbol *type;
 961         char *name;
 962         int i = 0;
 963
 964         name = get_fnptr_name(expr->fn);
 965         if (!name)
 966                 return;
 967
 968         FOR_EACH_PTR(expr->args, arg) {
 969                 type = get_arg_type(expr->fn, i);
 970
 971                 if (get_implied_range_list(arg, &rl))
 972                         rl = cast_rl(type, rl);
 973                 else
 974                         rl = whole_range_list(type);
 975
 976                 sm_msg("info: passes param_value '%s' %d '$$' %s %s",
 977                        name, i, show_ranges(rl),
 978                        is_static(expr->fn) ? "static" : "global");
 979                 i++;
 980         } END_FOR_EACH_PTR(arg);
 981
 982         free_string(name);
 983 }
 984
 985 static void set_param_value(const char *name, struct symbol *sym, char *key, char *value)
 986 {
 987         struct range_list *rl = NULL;
 988         struct smatch_state *state;
 989         struct symbol *type;
 990         char fullname[256];
 991
 992         if (strncmp(key, "$$", 2))
 993                 return;
 994
 995         snprintf(fullname, 256, "%s%s", name, key + 2);
 996         type = get_param_type_from_key(sym, key);
 997         parse_value_ranges_type(type, value, &rl);
 998         state = alloc_estate_range_list(rl);
 999         set_state(SMATCH_EXTRA, fullname, sym, state);
1000 }
1001
1002 void register_smatch_extra(int id)
1003 {
1004         my_id = id;
1005
1006         add_merge_hook(my_id, &merge_func);
1007         add_unmatched_state_hook(my_id, &unmatched_state);
1008         add_hook(&unop_expr, OP_HOOK);
1009         add_hook(&asm_expr, ASM_HOOK);
1010         add_hook(&match_function_def, FUNC_DEF_HOOK);
1011         add_hook(&match_declarations, DECLARATION_HOOK);
1012         if (option_info) {
1013                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
1014                 add_member_info_callback(my_id, struct_member_callback);
1015         }
1016         add_definition_db_callback(set_param_value, PARAM_VALUE);
1017 }
1018
1019 void register_smatch_extra_late(int id)
1020 {
1021         add_hook(&match_dereferences, DEREF_HOOK);
1022         add_hook(&match_pointer_as_array, OP_HOOK);
1023         add_db_fn_call_callback(DEREFERENCE, &set_param_dereferenced);
1024         add_indirect_modification_hook(SMATCH_EXTRA, reset_struct_members);
1025         add_hook(&match_function_call, FUNCTION_CALL_HOOK);
1026         add_hook(&match_assign, ASSIGNMENT_HOOK);
1027 }