smatch_function_hooks.c

   1 /*
   2  * sparse/smatch_function_hooks.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * There are several types of function hooks:
  12  * add_function_hook()        - For any time a function is called.
  13  * add_function_assign_hook() - foo = the_function().
  14  * add_implied_return_hook()  - Calculates the implied return value.
  15  * add_macro_assign_hook()    - foo = the_macro().
  16  * return_implies_state()     - For when a return value of 1 implies locked
  17  *                              and 0 implies unlocked. etc. etc.
  18  *
  19  */
  20
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include "smatch.h"
  24 #include "smatch_slist.h"
  25 #include "smatch_extra.h"
  26 #include "smatch_function_hashtable.h"
  27
  28 struct fcall_back {
  29         int type;
  30         struct data_range *range;
  31         union {
  32                 func_hook *call_back;
  33                 implication_hook *ranged;
  34                 implied_return_hook *implied_return;
  35         } u;
  36         void *info;
  37 };
  38
  39 ALLOCATOR(fcall_back, "call backs");
  40 DECLARE_PTR_LIST(call_back_list, struct fcall_back);
  41
  42 DEFINE_FUNCTION_HASHTABLE_STATIC(callback, struct fcall_back, struct call_back_list);
  43 static struct hashtable *func_hash;
  44
  45 #define REGULAR_CALL       0
  46 #define RANGED_CALL        1
  47 #define ASSIGN_CALL        2
  48 #define IMPLIED_RETURN     3
  49 #define MACRO_ASSIGN       4
  50 #define MACRO_ASSIGN_EXTRA 5
  51
  52 struct return_implies_callback {
  53         int type;
  54         return_implies_hook *callback;
  55 };
  56 ALLOCATOR(return_implies_callback, "return_implies callbacks");
  57 DECLARE_PTR_LIST(db_implies_list, struct return_implies_callback);
  58 static struct db_implies_list *db_implies_list;
  59 static struct db_implies_list *db_return_states_list;
  60
  61 static struct fcall_back *alloc_fcall_back(int type, void *call_back,
  62                                            void *info)
  63 {
  64         struct fcall_back *cb;
  65
  66         cb = __alloc_fcall_back(0);
  67         cb->type = type;
  68         cb->u.call_back = call_back;
  69         cb->info = info;
  70         return cb;
  71 }
  72
  73 void add_function_hook(const char *look_for, func_hook *call_back, void *info)
  74 {
  75         struct fcall_back *cb;
  76
  77         cb = alloc_fcall_back(REGULAR_CALL, call_back, info);
  78         add_callback(func_hash, look_for, cb);
  79 }
  80
  81 void add_function_assign_hook(const char *look_for, func_hook *call_back,
  82                               void *info)
  83 {
  84         struct fcall_back *cb;
  85
  86         cb = alloc_fcall_back(ASSIGN_CALL, call_back, info);
  87         add_callback(func_hash, look_for, cb);
  88 }
  89
  90 void add_implied_return_hook(const char *look_for,
  91                              implied_return_hook *call_back,
  92                              void *info)
  93 {
  94         struct fcall_back *cb;
  95
  96         cb = alloc_fcall_back(IMPLIED_RETURN, call_back, info);
  97         add_callback(func_hash, look_for, cb);
  98 }
  99
 100 void add_macro_assign_hook(const char *look_for, func_hook *call_back,
 101                         void *info)
 102 {
 103         struct fcall_back *cb;
 104
 105         cb = alloc_fcall_back(MACRO_ASSIGN, call_back, info);
 106         add_callback(func_hash, look_for, cb);
 107 }
 108
 109 void add_macro_assign_hook_extra(const char *look_for, func_hook *call_back,
 110                         void *info)
 111 {
 112         struct fcall_back *cb;
 113
 114         cb = alloc_fcall_back(MACRO_ASSIGN_EXTRA, call_back, info);
 115         add_callback(func_hash, look_for, cb);
 116 }
 117
 118 void return_implies_state(const char *look_for, long long start, long long end,
 119                          implication_hook *call_back, void *info)
 120 {
 121         struct fcall_back *cb;
 122
 123         cb = alloc_fcall_back(RANGED_CALL, call_back, info);
 124         cb->range = alloc_range_perm(start, end);
 125         add_callback(func_hash, look_for, cb);
 126 }
 127
 128 void add_db_return_implies_callback(int type, return_implies_hook *callback)
 129 {
 130         struct return_implies_callback *cb = __alloc_return_implies_callback(0);
 131
 132         cb->type = type;
 133         cb->callback = callback;
 134         add_ptr_list(&db_implies_list, cb);
 135 }
 136
 137 void add_db_return_states_callback(int type, return_implies_hook *callback)
 138 {
 139         struct return_implies_callback *cb = __alloc_return_implies_callback(0);
 140
 141         cb->type = type;
 142         cb->callback = callback;
 143         add_ptr_list(&db_return_states_list, cb);
 144 }
 145
 146 static int call_call_backs(struct call_back_list *list, int type,
 147                             const char *fn, struct expression *expr)
 148 {
 149         struct fcall_back *tmp;
 150         int handled = 0;
 151
 152         FOR_EACH_PTR(list, tmp) {
 153                 if (tmp->type == type) {
 154                         (tmp->u.call_back)(fn, expr, tmp->info);
 155                         handled = 1;
 156                 }
 157         } END_FOR_EACH_PTR(tmp);
 158
 159         return handled;
 160 }
 161
 162 static void call_ranged_call_backs(struct call_back_list *list,
 163                                 const char *fn, struct expression *call_expr,
 164                                 struct expression *assign_expr)
 165 {
 166         struct fcall_back *tmp;
 167
 168         FOR_EACH_PTR(list, tmp) {
 169                 (tmp->u.ranged)(fn, call_expr, assign_expr, tmp->info);
 170         } END_FOR_EACH_PTR(tmp);
 171 }
 172
 173 static struct call_back_list *get_same_ranged_call_backs(struct call_back_list *list,
 174                                                 struct data_range_sval *drange)
 175 {
 176         struct call_back_list *ret = NULL;
 177         struct fcall_back *tmp;
 178
 179         FOR_EACH_PTR(list, tmp) {
 180                 struct data_range_sval *range_tmp;
 181
 182                 if (tmp->type != RANGED_CALL)
 183                         continue;
 184                 range_tmp = drange_to_drange_sval(tmp->range);
 185                 if (ranges_equiv_sval(range_tmp, drange))
 186                         add_ptr_list(&ret, tmp);
 187         } END_FOR_EACH_PTR(tmp);
 188         return ret;
 189 }
 190
 191 static int in_list_exact_sval(struct range_list_sval *list, struct data_range_sval *drange)
 192 {
 193         struct data_range_sval *tmp;
 194
 195         FOR_EACH_PTR(list, tmp) {
 196                 if (ranges_equiv_sval(tmp, drange))
 197                         return 1;
 198         } END_FOR_EACH_PTR(tmp);
 199         return 0;
 200 }
 201
 202 static int assign_ranged_funcs(const char *fn, struct expression *expr,
 203                                  struct call_back_list *call_backs)
 204 {
 205         struct fcall_back *tmp;
 206         struct sm_state *sm;
 207         char *var_name;
 208         struct symbol *sym;
 209         struct smatch_state *estate;
 210         struct state_list *tmp_slist;
 211         struct state_list *final_states = NULL;
 212         struct range_list_sval *handled_ranges = NULL;
 213         struct call_back_list *same_range_call_backs = NULL;
 214         int handled = 0;
 215
 216         if (!call_backs)
 217                 return 0;
 218
 219         var_name = get_variable_from_expr(expr->left, &sym);
 220         if (!var_name || !sym)
 221                 goto free;
 222
 223         FOR_EACH_PTR(call_backs, tmp) {
 224                 struct data_range_sval *tmp_dr_sval;
 225
 226                 if (tmp->type != RANGED_CALL)
 227                         continue;
 228                 tmp_dr_sval = drange_to_drange_sval(tmp->range);
 229
 230                 if (in_list_exact_sval(handled_ranges, tmp_dr_sval))
 231                         continue;
 232                 __push_fake_cur_slist();
 233                 tack_on_sval(&handled_ranges, tmp_dr_sval);
 234
 235                 same_range_call_backs = get_same_ranged_call_backs(call_backs, tmp_dr_sval);
 236                 call_ranged_call_backs(same_range_call_backs, fn, expr->right, expr);
 237                 __free_ptr_list((struct ptr_list **)&same_range_call_backs);
 238
 239                 estate = alloc_estate_range_sval(tmp_dr_sval->min, tmp_dr_sval->max);
 240                 set_extra_mod(var_name, sym, estate);
 241
 242                 tmp_slist = __pop_fake_cur_slist();
 243                 merge_slist(&final_states, tmp_slist);
 244                 free_slist(&tmp_slist);
 245                 handled = 1;
 246         } END_FOR_EACH_PTR(tmp);
 247
 248         FOR_EACH_PTR(final_states, sm) {
 249                 __set_sm(sm);
 250         } END_FOR_EACH_PTR(sm);
 251
 252         free_slist(&final_states);
 253 free:
 254         free_string(var_name);
 255         return handled;
 256 }
 257
 258 static int call_implies_callbacks(int comparison, struct expression *expr, sval_t sval, int left)
 259 {
 260         struct call_back_list *call_backs;
 261         struct fcall_back *tmp;
 262         const char *fn;
 263         struct data_range_sval *value_range;
 264         struct state_list *true_states = NULL;
 265         struct state_list *false_states = NULL;
 266         struct state_list *tmp_slist;
 267         struct sm_state *sm;
 268
 269         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 270                 return 0;
 271         fn = expr->fn->symbol->ident->name;
 272         call_backs = search_callback(func_hash, (char *)expr->fn->symbol->ident->name);
 273         if (!call_backs)
 274                 return 0;
 275         value_range = alloc_range_sval(sval, sval);
 276
 277         /* set true states */
 278         __push_fake_cur_slist();
 279         FOR_EACH_PTR(call_backs, tmp) {
 280                 if (tmp->type != RANGED_CALL)
 281                         continue;
 282                 if (!true_comparison_range_lr_sval(comparison, drange_to_drange_sval(tmp->range), value_range, left))
 283                         continue;
 284                 (tmp->u.ranged)(fn, expr, NULL, tmp->info);
 285         } END_FOR_EACH_PTR(tmp);
 286         tmp_slist = __pop_fake_cur_slist();
 287         merge_slist(&true_states, tmp_slist);
 288         free_slist(&tmp_slist);
 289
 290         /* set false states */
 291         __push_fake_cur_slist();
 292         FOR_EACH_PTR(call_backs, tmp) {
 293                 if (tmp->type != RANGED_CALL)
 294                         continue;
 295                 if (!false_comparison_range_lr_sval(comparison, drange_to_drange_sval(tmp->range), value_range, left))
 296                         continue;
 297                 (tmp->u.ranged)(fn, expr, NULL, tmp->info);
 298         } END_FOR_EACH_PTR(tmp);
 299         tmp_slist = __pop_fake_cur_slist();
 300         merge_slist(&false_states, tmp_slist);
 301         free_slist(&tmp_slist);
 302
 303         FOR_EACH_PTR(true_states, sm) {
 304                 __set_true_false_sm(sm, NULL);
 305         } END_FOR_EACH_PTR(sm);
 306         FOR_EACH_PTR(false_states, sm) {
 307                 __set_true_false_sm(NULL, sm);
 308         } END_FOR_EACH_PTR(sm);
 309
 310         free_slist(&true_states);
 311         free_slist(&false_states);
 312         return 1;
 313 }
 314
 315 struct db_callback_info {
 316         int true_side;
 317         int comparison;
 318         struct expression *expr;
 319         struct range_list_sval *rl;
 320         int left;
 321         struct state_list *slist;
 322         struct db_implies_list *callbacks;
 323 };
 324 static struct db_callback_info db_info;
 325 static int db_compare_callback(void *unused, int argc, char **argv, char **azColName)
 326 {
 327         struct range_list_sval *ret_range;
 328         int type, param;
 329         char *key, *value;
 330         struct return_implies_callback *tmp;
 331
 332         if (argc != 5)
 333                 return 0;
 334
 335         get_value_ranges_sval(argv[0], &ret_range);
 336         type = atoi(argv[1]);
 337         param = atoi(argv[2]);
 338         key = argv[3];
 339         value = argv[4];
 340
 341         if (db_info.true_side) {
 342                 if (!possibly_true_range_lists_rl_sval(db_info.comparison,
 343                                                   ret_range, db_info.rl,
 344                                                   db_info.left))
 345                         return 0;
 346         } else {
 347                 if (!possibly_false_range_lists_rl_sval(db_info.comparison,
 348                                                   ret_range, db_info.rl,
 349                                                   db_info.left))
 350                         return 0;
 351         }
 352
 353         FOR_EACH_PTR(db_info.callbacks, tmp) {
 354                 if (tmp->type == type)
 355                         tmp->callback(db_info.expr, param, key, value);
 356         } END_FOR_EACH_PTR(tmp);
 357         return 0;
 358 }
 359
 360 void compare_db_implies_callbacks(int comparison, struct expression *expr, sval_t sval, int left)
 361 {
 362         struct symbol *sym;
 363         static char sql_filter[1024];
 364         struct state_list *true_states;
 365         struct state_list *false_states;
 366         struct sm_state *sm;
 367
 368         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 369                 return;
 370
 371         sym = expr->fn->symbol;
 372         if (!sym)
 373                 return;
 374
 375         if (sym->ctype.modifiers & MOD_STATIC) {
 376                 snprintf(sql_filter, 1024,
 377                          "file = '%s' and function = '%s' and static = '1';",
 378                          get_filename(), sym->ident->name);
 379         } else {
 380                 snprintf(sql_filter, 1024,
 381                          "function = '%s' and static = '0';", sym->ident->name);
 382         }
 383
 384         db_info.comparison = comparison;
 385         db_info.expr = expr;
 386         db_info.rl = alloc_range_list_sval(sval, sval);
 387         db_info.left = left;
 388         db_info.callbacks = db_implies_list;
 389
 390         db_info.true_side = 1;
 391         __push_fake_cur_slist();
 392         run_sql(db_compare_callback,
 393                 "select return, type, parameter, key, value from return_implies where %s",
 394                 sql_filter);
 395         true_states = __pop_fake_cur_slist();
 396
 397         db_info.true_side = 0;
 398         __push_fake_cur_slist();
 399         run_sql(db_compare_callback,
 400                 "select return, type, parameter, key, value from return_implies where %s",
 401                 sql_filter);
 402         false_states = __pop_fake_cur_slist();
 403
 404         FOR_EACH_PTR(true_states, sm) {
 405                 __set_true_false_sm(sm, NULL);
 406         } END_FOR_EACH_PTR(sm);
 407         FOR_EACH_PTR(false_states, sm) {
 408                 __set_true_false_sm(NULL, sm);
 409         } END_FOR_EACH_PTR(sm);
 410
 411         free_slist(&true_states);
 412         free_slist(&false_states);
 413 }
 414
 415 void compare_db_return_states_callbacks(int comparison, struct expression *expr, sval_t sval, int left)
 416 {
 417         struct symbol *sym;
 418         static char sql_filter[1024];
 419         struct state_list *true_states;
 420         struct state_list *false_states;
 421         struct sm_state *sm;
 422
 423         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 424                 return;
 425
 426         sym = expr->fn->symbol;
 427         if (!sym)
 428                 return;
 429
 430         if (sym->ctype.modifiers & MOD_STATIC) {
 431                 snprintf(sql_filter, 1024,
 432                          "file = '%s' and function = '%s' and static = '1';",
 433                          get_filename(), sym->ident->name);
 434         } else {
 435                 snprintf(sql_filter, 1024,
 436                          "function = '%s' and static = '0';", sym->ident->name);
 437         }
 438
 439         db_info.comparison = comparison;
 440         db_info.expr = expr;
 441         db_info.rl = alloc_range_list_sval(sval, sval);
 442         db_info.left = left;
 443         db_info.callbacks = db_return_states_list;
 444
 445         db_info.true_side = 1;
 446         __push_fake_cur_slist();
 447         run_sql(db_compare_callback,
 448                 "select return, type, parameter, key, value from return_states where %s",
 449                 sql_filter);
 450         true_states = __pop_fake_cur_slist();
 451
 452         db_info.true_side = 0;
 453         __push_fake_cur_slist();
 454         run_sql(db_compare_callback,
 455                 "select return, type, parameter, key, value from return_states where %s",
 456                 sql_filter);
 457         false_states = __pop_fake_cur_slist();
 458
 459         FOR_EACH_PTR(true_states, sm) {
 460                 __set_true_false_sm(sm, NULL);
 461         } END_FOR_EACH_PTR(sm);
 462         FOR_EACH_PTR(false_states, sm) {
 463                 __set_true_false_sm(NULL, sm);
 464         } END_FOR_EACH_PTR(sm);
 465
 466         free_slist(&true_states);
 467         free_slist(&false_states);
 468 }
 469
 470
 471
 472 void function_comparison(int comparison, struct expression *expr, sval_t sval, int left)
 473 {
 474         if (call_implies_callbacks(comparison, expr, sval, left))
 475                 return;
 476         compare_db_implies_callbacks(comparison, expr, sval, left);
 477         compare_db_return_states_callbacks(comparison, expr, sval, left);
 478 }
 479
 480 static int db_assign_callback(void *unused, int argc, char **argv, char **azColName)
 481 {
 482         struct range_list_sval *ret_range;
 483         int type, param;
 484         char *key, *value;
 485         struct return_implies_callback *tmp;
 486         struct state_list *slist;
 487
 488         if (argc != 5)
 489                 return 0;
 490
 491         get_value_ranges_sval(argv[0], &ret_range);
 492         type = atoi(argv[1]);
 493         param = atoi(argv[2]);
 494         key = argv[3];
 495         value = argv[4];
 496
 497         __push_fake_cur_slist();
 498         FOR_EACH_PTR(db_implies_list, tmp) {
 499                 if (tmp->type == type)
 500                         tmp->callback(db_info.expr->right, param, key, value);
 501         } END_FOR_EACH_PTR(tmp);
 502         set_extra_expr_mod(db_info.expr->left, alloc_estate_range_list_sval(ret_range));
 503         slist = __pop_fake_cur_slist();
 504
 505         merge_slist(&db_info.slist, slist);
 506
 507         return 0;
 508 }
 509
 510 static int db_return_implies_assign(struct expression *expr)
 511 {
 512         struct symbol *sym;
 513         static char sql_filter[1024];
 514         static struct sm_state *sm;
 515         int handled = 0;
 516
 517         if (expr->right->fn->type != EXPR_SYMBOL || !expr->right->fn->symbol)
 518                 return 0;
 519
 520         sym = expr->right->fn->symbol;
 521         if (!sym)
 522                 return 0;
 523
 524         if (sym->ctype.modifiers & MOD_STATIC) {
 525                 snprintf(sql_filter, 1024,
 526                          "file = '%s' and function = '%s' and static = '1';",
 527                          get_filename(), sym->ident->name);
 528         } else {
 529                 snprintf(sql_filter, 1024,
 530                          "function = '%s' and static = '0';", sym->ident->name);
 531         }
 532
 533         db_info.expr = expr;
 534         db_info.slist = NULL;
 535         run_sql(db_assign_callback,
 536                 "select return, type, parameter, key, value from return_implies where %s",
 537                 sql_filter);
 538
 539         FOR_EACH_PTR(db_info.slist, sm) {
 540                 __set_sm(sm);
 541                 handled = 1;
 542         } END_FOR_EACH_PTR(sm);
 543
 544         return handled;
 545 }
 546
 547 static int prev_return_id;
 548 static int db_assign_return_states_callback(void *unused, int argc, char **argv, char **azColName)
 549 {
 550         struct range_list_sval *ret_range;
 551         int type, param;
 552         char *key, *value;
 553         struct return_implies_callback *tmp;
 554         struct state_list *slist;
 555         int return_id;
 556
 557         if (argc != 6)
 558                 return 0;
 559
 560         return_id = atoi(argv[0]);
 561         get_value_ranges_sval(argv[1], &ret_range);
 562         if (!ret_range)
 563                 ret_range = whole_range_list_sval();
 564         type = atoi(argv[2]);
 565         param = atoi(argv[3]);
 566         key = argv[4];
 567         value = argv[5];
 568
 569         if (prev_return_id != -1 && return_id != prev_return_id) {
 570                 slist = __pop_fake_cur_slist();
 571                 merge_slist(&db_info.slist, slist);
 572                 __push_fake_cur_slist();
 573         }
 574         prev_return_id = return_id;
 575
 576         FOR_EACH_PTR(db_return_states_list, tmp) {
 577                 if (tmp->type == type)
 578                         tmp->callback(db_info.expr, param, key, value);
 579         } END_FOR_EACH_PTR(tmp);
 580         set_extra_expr_mod(db_info.expr->left, alloc_estate_range_list_sval(ret_range));
 581
 582         return 0;
 583 }
 584
 585 static int db_return_states_assign(struct expression *expr)
 586 {
 587         struct expression *right;
 588         struct symbol *sym;
 589         struct sm_state *sm;
 590         struct state_list *slist;
 591         static char sql_filter[1024];
 592         int handled = 0;
 593
 594         right = strip_expr(expr->right);
 595         if (right->fn->type != EXPR_SYMBOL || !right->fn->symbol)
 596                 return 0;
 597
 598         sym = right->fn->symbol;
 599         if (!sym)
 600                 return 0;
 601
 602         if (sym->ctype.modifiers & MOD_STATIC) {
 603                 snprintf(sql_filter, 1024,
 604                          "file = '%s' and function = '%s' and static = '1';",
 605                          get_filename(), sym->ident->name);
 606         } else {
 607                 snprintf(sql_filter, 1024,
 608                          "function = '%s' and static = '0';", sym->ident->name);
 609         }
 610
 611         prev_return_id = -1;
 612         db_info.expr = expr;
 613         db_info.slist = NULL;
 614         __push_fake_cur_slist();
 615         run_sql(db_assign_return_states_callback,
 616                 "select return_id, return, type, parameter, key, value from return_states where %s",
 617                 sql_filter);
 618         slist = __pop_fake_cur_slist();
 619         merge_slist(&db_info.slist, slist);
 620
 621         FOR_EACH_PTR(db_info.slist, sm) {
 622                 __set_sm(sm);
 623                 handled = 1;
 624         } END_FOR_EACH_PTR(sm);
 625
 626         return handled;
 627 }
 628
 629 static int handle_implied_return(struct expression *expr)
 630 {
 631         struct range_list_sval *rl;
 632
 633         if (!get_implied_return_sval(expr->right, &rl))
 634                 return 0;
 635         set_extra_expr_mod(expr->left, alloc_estate_range_list_sval(rl));
 636         return 1;
 637 }
 638
 639 static void match_assign_call(struct expression *expr)
 640 {
 641         struct call_back_list *call_backs;
 642         const char *fn;
 643         struct expression *right;
 644         int handled = 0;
 645
 646         right = strip_expr(expr->right);
 647         if (right->fn->type != EXPR_SYMBOL || !right->fn->symbol) {
 648                 set_extra_expr_mod(expr->left, extra_undefined());
 649                 return;
 650         }
 651         fn = right->fn->symbol->ident->name;
 652
 653         /*
 654          * some of these conflict (they try to set smatch extra twice), so we
 655          * call them in order from least important to most important.
 656          */
 657
 658         call_backs = search_callback(func_hash, (char *)fn);
 659         call_call_backs(call_backs, ASSIGN_CALL, fn, expr);
 660
 661         handled |= db_return_states_assign(expr);
 662         handled |= db_return_implies_assign(expr);
 663         handled |= assign_ranged_funcs(fn, expr, call_backs);
 664         handled |= handle_implied_return(expr);
 665
 666         if (!handled)
 667                 set_extra_expr_mod(expr->left, extra_undefined());
 668 }
 669
 670 static int db_return_states_callback(void *unused, int argc, char **argv, char **azColName)
 671 {
 672         struct range_list_sval *ret_range;
 673         int type, param;
 674         char *key, *value;
 675         struct return_implies_callback *tmp;
 676         struct state_list *slist;
 677         int return_id;
 678
 679         if (argc != 6)
 680                 return 0;
 681
 682         return_id = atoi(argv[0]);
 683         get_value_ranges_sval(argv[1], &ret_range);
 684         type = atoi(argv[2]);
 685         param = atoi(argv[3]);
 686         key = argv[4];
 687         value = argv[5];
 688
 689         if (prev_return_id != -1 && return_id != prev_return_id) {
 690                 slist = __pop_fake_cur_slist();
 691                 merge_slist(&db_info.slist, slist);
 692                 __push_fake_cur_slist();
 693         }
 694         prev_return_id = return_id;
 695
 696         FOR_EACH_PTR(db_return_states_list, tmp) {
 697                 if (tmp->type == type)
 698                         tmp->callback(db_info.expr, param, key, value);
 699         } END_FOR_EACH_PTR(tmp);
 700
 701         return 0;
 702 }
 703
 704 static void db_return_states(struct expression *expr)
 705 {
 706         struct symbol *sym;
 707         struct sm_state *sm;
 708         struct state_list *slist;
 709         static char sql_filter[1024];
 710
 711         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 712                 return;
 713
 714         sym = expr->fn->symbol;
 715         if (!sym)
 716                 return;
 717
 718         if (sym->ctype.modifiers & MOD_STATIC) {
 719                 snprintf(sql_filter, 1024,
 720                          "file = '%s' and function = '%s' and static = '1';",
 721                          get_filename(), sym->ident->name);
 722         } else {
 723                 snprintf(sql_filter, 1024,
 724                          "function = '%s' and static = '0';", sym->ident->name);
 725         }
 726
 727         prev_return_id = -1;
 728         db_info.expr = expr;
 729         db_info.slist = NULL;
 730         __push_fake_cur_slist();
 731         run_sql(db_return_states_callback,
 732                 "select return_id, return, type, parameter, key, value from return_states where %s",
 733                 sql_filter);
 734         slist = __pop_fake_cur_slist();
 735         merge_slist(&db_info.slist, slist);
 736
 737         FOR_EACH_PTR(db_info.slist, sm) {
 738                 __set_sm(sm);
 739         } END_FOR_EACH_PTR(sm);
 740 }
 741
 742 static int is_assigned_call(struct expression *expr)
 743 {
 744         struct expression *tmp;
 745
 746         FOR_EACH_PTR_REVERSE(big_expression_stack, tmp) {
 747                 if (tmp->type == EXPR_ASSIGNMENT && strip_expr(tmp->right) == expr)
 748                         return 1;
 749                 if (tmp->pos.line < expr->pos.line)
 750                         return 0;
 751         } END_FOR_EACH_PTR_REVERSE(tmp);
 752         return 0;
 753 }
 754
 755 static void db_return_states_call(struct expression *expr)
 756 {
 757         if (is_assigned_call(expr))
 758                 return;
 759         db_return_states(expr);
 760 }
 761
 762 static void match_function_call(struct expression *expr)
 763 {
 764         struct call_back_list *call_backs;
 765
 766         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 767                 return;
 768         call_backs = search_callback(func_hash, (char *)expr->fn->symbol->ident->name);
 769         if (call_backs)
 770                 call_call_backs(call_backs, REGULAR_CALL,
 771                                 expr->fn->symbol->ident->name, expr);
 772         db_return_states_call(expr);
 773 }
 774
 775 static void match_macro_assign(struct expression *expr)
 776 {
 777         struct call_back_list *call_backs;
 778         const char *macro;
 779         struct expression *right;
 780
 781         right = strip_expr(expr->right);
 782         macro = get_macro_name(right->pos);
 783         call_backs = search_callback(func_hash, (char *)macro);
 784         if (!call_backs)
 785                 return;
 786         call_call_backs(call_backs, MACRO_ASSIGN, macro, expr);
 787         call_call_backs(call_backs, MACRO_ASSIGN_EXTRA, macro, expr);
 788 }
 789
 790 int get_implied_return_sval(struct expression *expr, struct range_list_sval **rl)
 791 {
 792         struct call_back_list *call_backs;
 793         struct fcall_back *tmp;
 794         int handled = 0;
 795         char *fn;
 796
 797         *rl = NULL;
 798
 799         expr = strip_expr(expr);
 800         fn = get_variable_from_expr(expr->fn, NULL);
 801         if (!fn)
 802                 goto out;
 803
 804         call_backs = search_callback(func_hash, fn);
 805
 806         FOR_EACH_PTR(call_backs, tmp) {
 807                 if (tmp->type == IMPLIED_RETURN) {
 808                         (tmp->u.implied_return)(expr, tmp->info, rl);
 809                         handled = 1;
 810                 }
 811         } END_FOR_EACH_PTR(tmp);
 812
 813 out:
 814         free_string(fn);
 815         return handled;
 816 }
 817
 818 void create_function_hook_hash(void)
 819 {
 820         func_hash = create_function_hashtable(5000);
 821 }
 822
 823 void register_function_hooks(int id)
 824 {
 825         add_hook(&match_function_call, FUNCTION_CALL_HOOK);
 826         add_hook(&match_assign_call, CALL_ASSIGNMENT_HOOK);
 827         add_hook(&match_macro_assign, MACRO_ASSIGNMENT_HOOK);
 828 }