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(ll_to_sval(start), ll_to_sval(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 *drange)
 175 {
 176         struct call_back_list *ret = NULL;
 177         struct fcall_back *tmp;
 178
 179         FOR_EACH_PTR(list, tmp) {
 180                 if (tmp->type != RANGED_CALL)
 181                         continue;
 182                 if (ranges_equiv(tmp->range, drange))
 183                         add_ptr_list(&ret, tmp);
 184         } END_FOR_EACH_PTR(tmp);
 185         return ret;
 186 }
 187
 188 static int in_list_exact_sval(struct range_list *list, struct data_range *drange)
 189 {
 190         struct data_range *tmp;
 191
 192         FOR_EACH_PTR(list, tmp) {
 193                 if (ranges_equiv(tmp, drange))
 194                         return 1;
 195         } END_FOR_EACH_PTR(tmp);
 196         return 0;
 197 }
 198
 199 static int assign_ranged_funcs(const char *fn, struct expression *expr,
 200                                  struct call_back_list *call_backs)
 201 {
 202         struct fcall_back *tmp;
 203         struct sm_state *sm;
 204         char *var_name;
 205         struct symbol *sym;
 206         struct smatch_state *estate;
 207         struct state_list *tmp_slist;
 208         struct state_list *final_states = NULL;
 209         struct range_list *handled_ranges = NULL;
 210         struct call_back_list *same_range_call_backs = NULL;
 211         int handled = 0;
 212
 213         if (!call_backs)
 214                 return 0;
 215
 216         var_name = get_variable_from_expr(expr->left, &sym);
 217         if (!var_name || !sym)
 218                 goto free;
 219
 220         FOR_EACH_PTR(call_backs, tmp) {
 221                 if (tmp->type != RANGED_CALL)
 222                         continue;
 223
 224                 if (in_list_exact_sval(handled_ranges, tmp->range))
 225                         continue;
 226                 __push_fake_cur_slist();
 227                 tack_on(&handled_ranges, tmp->range);
 228
 229                 same_range_call_backs = get_same_ranged_call_backs(call_backs, tmp->range);
 230                 call_ranged_call_backs(same_range_call_backs, fn, expr->right, expr);
 231                 __free_ptr_list((struct ptr_list **)&same_range_call_backs);
 232
 233                 estate = alloc_estate_range(tmp->range->min, tmp->range->max);
 234                 set_extra_mod(var_name, sym, estate);
 235
 236                 tmp_slist = __pop_fake_cur_slist();
 237                 merge_slist(&final_states, tmp_slist);
 238                 free_slist(&tmp_slist);
 239                 handled = 1;
 240         } END_FOR_EACH_PTR(tmp);
 241
 242         FOR_EACH_PTR(final_states, sm) {
 243                 __set_sm(sm);
 244         } END_FOR_EACH_PTR(sm);
 245
 246         free_slist(&final_states);
 247 free:
 248         free_string(var_name);
 249         return handled;
 250 }
 251
 252 static int call_implies_callbacks(int comparison, struct expression *expr, sval_t sval, int left)
 253 {
 254         struct call_back_list *call_backs;
 255         struct fcall_back *tmp;
 256         const char *fn;
 257         struct data_range *value_range;
 258         struct state_list *true_states = NULL;
 259         struct state_list *false_states = NULL;
 260         struct state_list *tmp_slist;
 261         struct sm_state *sm;
 262
 263         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 264                 return 0;
 265         fn = expr->fn->symbol->ident->name;
 266         call_backs = search_callback(func_hash, (char *)expr->fn->symbol->ident->name);
 267         if (!call_backs)
 268                 return 0;
 269         value_range = alloc_range(sval, sval);
 270
 271         /* set true states */
 272         __push_fake_cur_slist();
 273         FOR_EACH_PTR(call_backs, tmp) {
 274                 if (tmp->type != RANGED_CALL)
 275                         continue;
 276                 if (!true_comparison_range_lr(comparison, tmp->range, value_range, left))
 277                         continue;
 278                 (tmp->u.ranged)(fn, expr, NULL, tmp->info);
 279         } END_FOR_EACH_PTR(tmp);
 280         tmp_slist = __pop_fake_cur_slist();
 281         merge_slist(&true_states, tmp_slist);
 282         free_slist(&tmp_slist);
 283
 284         /* set false states */
 285         __push_fake_cur_slist();
 286         FOR_EACH_PTR(call_backs, tmp) {
 287                 if (tmp->type != RANGED_CALL)
 288                         continue;
 289                 if (!false_comparison_range_lr(comparison, tmp->range, value_range, left))
 290                         continue;
 291                 (tmp->u.ranged)(fn, expr, NULL, tmp->info);
 292         } END_FOR_EACH_PTR(tmp);
 293         tmp_slist = __pop_fake_cur_slist();
 294         merge_slist(&false_states, tmp_slist);
 295         free_slist(&tmp_slist);
 296
 297         FOR_EACH_PTR(true_states, sm) {
 298                 __set_true_false_sm(sm, NULL);
 299         } END_FOR_EACH_PTR(sm);
 300         FOR_EACH_PTR(false_states, sm) {
 301                 __set_true_false_sm(NULL, sm);
 302         } END_FOR_EACH_PTR(sm);
 303
 304         free_slist(&true_states);
 305         free_slist(&false_states);
 306         return 1;
 307 }
 308
 309 struct db_callback_info {
 310         int true_side;
 311         int comparison;
 312         struct expression *expr;
 313         struct range_list *rl;
 314         int left;
 315         struct state_list *slist;
 316         struct db_implies_list *callbacks;
 317 };
 318 static struct db_callback_info db_info;
 319 static int db_compare_callback(void *unused, int argc, char **argv, char **azColName)
 320 {
 321         struct range_list *ret_range;
 322         int type, param;
 323         char *key, *value;
 324         struct return_implies_callback *tmp;
 325
 326         if (argc != 5)
 327                 return 0;
 328
 329         parse_value_ranges_type(get_type(db_info.expr), argv[0], &ret_range);
 330         type = atoi(argv[1]);
 331         param = atoi(argv[2]);
 332         key = argv[3];
 333         value = argv[4];
 334
 335         if (db_info.true_side) {
 336                 if (!possibly_true_range_lists_lr(db_info.comparison,
 337                                                   ret_range, db_info.rl,
 338                                                   db_info.left))
 339                         return 0;
 340         } else {
 341                 if (!possibly_false_range_lists_lr(db_info.comparison,
 342                                                   ret_range, db_info.rl,
 343                                                   db_info.left))
 344                         return 0;
 345         }
 346
 347         FOR_EACH_PTR(db_info.callbacks, tmp) {
 348                 if (tmp->type == type)
 349                         tmp->callback(db_info.expr, param, key, value);
 350         } END_FOR_EACH_PTR(tmp);
 351         return 0;
 352 }
 353
 354 void compare_db_implies_callbacks(int comparison, struct expression *expr, sval_t sval, int left)
 355 {
 356         struct symbol *sym;
 357         static char sql_filter[1024];
 358         struct state_list *true_states;
 359         struct state_list *false_states;
 360         struct sm_state *sm;
 361
 362         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 363                 return;
 364
 365         sym = expr->fn->symbol;
 366         if (!sym)
 367                 return;
 368
 369         if (sym->ctype.modifiers & MOD_STATIC) {
 370                 snprintf(sql_filter, 1024,
 371                          "file = '%s' and function = '%s' and static = '1';",
 372                          get_filename(), sym->ident->name);
 373         } else {
 374                 snprintf(sql_filter, 1024,
 375                          "function = '%s' and static = '0';", sym->ident->name);
 376         }
 377
 378         db_info.comparison = comparison;
 379         db_info.expr = expr;
 380         db_info.rl = alloc_range_list(sval, sval);
 381         db_info.left = left;
 382         db_info.callbacks = db_implies_list;
 383
 384         db_info.true_side = 1;
 385         __push_fake_cur_slist();
 386         run_sql(db_compare_callback,
 387                 "select return, type, parameter, key, value from return_implies where %s",
 388                 sql_filter);
 389         true_states = __pop_fake_cur_slist();
 390
 391         db_info.true_side = 0;
 392         __push_fake_cur_slist();
 393         run_sql(db_compare_callback,
 394                 "select return, type, parameter, key, value from return_implies where %s",
 395                 sql_filter);
 396         false_states = __pop_fake_cur_slist();
 397
 398         FOR_EACH_PTR(true_states, sm) {
 399                 __set_true_false_sm(sm, NULL);
 400         } END_FOR_EACH_PTR(sm);
 401         FOR_EACH_PTR(false_states, sm) {
 402                 __set_true_false_sm(NULL, sm);
 403         } END_FOR_EACH_PTR(sm);
 404
 405         free_slist(&true_states);
 406         free_slist(&false_states);
 407 }
 408
 409 void compare_db_return_states_callbacks(int comparison, struct expression *expr, sval_t sval, int left)
 410 {
 411         struct symbol *sym;
 412         static char sql_filter[1024];
 413         struct state_list *true_states;
 414         struct state_list *false_states;
 415         struct sm_state *sm;
 416
 417         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 418                 return;
 419
 420         sym = expr->fn->symbol;
 421         if (!sym)
 422                 return;
 423
 424         if (sym->ctype.modifiers & MOD_STATIC) {
 425                 snprintf(sql_filter, 1024,
 426                          "file = '%s' and function = '%s' and static = '1';",
 427                          get_filename(), sym->ident->name);
 428         } else {
 429                 snprintf(sql_filter, 1024,
 430                          "function = '%s' and static = '0';", sym->ident->name);
 431         }
 432
 433         db_info.comparison = comparison;
 434         db_info.expr = expr;
 435         db_info.rl = alloc_range_list(sval, sval);
 436         db_info.left = left;
 437         db_info.callbacks = db_return_states_list;
 438
 439         db_info.true_side = 1;
 440         __push_fake_cur_slist();
 441         run_sql(db_compare_callback,
 442                 "select return, type, parameter, key, value from return_states where %s",
 443                 sql_filter);
 444         true_states = __pop_fake_cur_slist();
 445
 446         db_info.true_side = 0;
 447         __push_fake_cur_slist();
 448         run_sql(db_compare_callback,
 449                 "select return, type, parameter, key, value from return_states where %s",
 450                 sql_filter);
 451         false_states = __pop_fake_cur_slist();
 452
 453         FOR_EACH_PTR(true_states, sm) {
 454                 __set_true_false_sm(sm, NULL);
 455         } END_FOR_EACH_PTR(sm);
 456         FOR_EACH_PTR(false_states, sm) {
 457                 __set_true_false_sm(NULL, sm);
 458         } END_FOR_EACH_PTR(sm);
 459
 460         free_slist(&true_states);
 461         free_slist(&false_states);
 462 }
 463
 464
 465
 466 void function_comparison(int comparison, struct expression *expr, sval_t sval, int left)
 467 {
 468         if (call_implies_callbacks(comparison, expr, sval, left))
 469                 return;
 470         compare_db_implies_callbacks(comparison, expr, sval, left);
 471         compare_db_return_states_callbacks(comparison, expr, sval, left);
 472 }
 473
 474 static int db_assign_callback(void *unused, int argc, char **argv, char **azColName)
 475 {
 476         struct range_list *ret_range;
 477         int type, param;
 478         char *key, *value;
 479         struct return_implies_callback *tmp;
 480         struct state_list *slist;
 481
 482         if (argc != 5)
 483                 return 0;
 484
 485         parse_value_ranges_type(get_type(db_info.expr->right), argv[0], &ret_range);
 486         type = atoi(argv[1]);
 487         param = atoi(argv[2]);
 488         key = argv[3];
 489         value = argv[4];
 490
 491         __push_fake_cur_slist();
 492         FOR_EACH_PTR(db_implies_list, tmp) {
 493                 if (tmp->type == type)
 494                         tmp->callback(db_info.expr->right, param, key, value);
 495         } END_FOR_EACH_PTR(tmp);
 496         ret_range = cast_rl(get_type(db_info.expr->left), ret_range);
 497         set_extra_expr_mod(db_info.expr->left, alloc_estate_range_list(ret_range));
 498         slist = __pop_fake_cur_slist();
 499
 500         merge_slist(&db_info.slist, slist);
 501
 502         return 0;
 503 }
 504
 505 static int db_return_implies_assign(struct expression *expr)
 506 {
 507         struct symbol *sym;
 508         static char sql_filter[1024];
 509         static struct sm_state *sm;
 510         int handled = 0;
 511
 512         if (expr->right->fn->type != EXPR_SYMBOL || !expr->right->fn->symbol)
 513                 return 0;
 514
 515         sym = expr->right->fn->symbol;
 516         if (!sym)
 517                 return 0;
 518
 519         if (sym->ctype.modifiers & MOD_STATIC) {
 520                 snprintf(sql_filter, 1024,
 521                          "file = '%s' and function = '%s' and static = '1';",
 522                          get_filename(), sym->ident->name);
 523         } else {
 524                 snprintf(sql_filter, 1024,
 525                          "function = '%s' and static = '0';", sym->ident->name);
 526         }
 527
 528         db_info.expr = expr;
 529         db_info.slist = NULL;
 530         run_sql(db_assign_callback,
 531                 "select return, type, parameter, key, value from return_implies where %s",
 532                 sql_filter);
 533
 534         FOR_EACH_PTR(db_info.slist, sm) {
 535                 __set_sm(sm);
 536                 handled = 1;
 537         } END_FOR_EACH_PTR(sm);
 538
 539         return handled;
 540 }
 541
 542 static int prev_return_id;
 543 static int db_assign_return_states_callback(void *unused, int argc, char **argv, char **azColName)
 544 {
 545         struct range_list *ret_range;
 546         int type, param;
 547         char *key, *value;
 548         struct return_implies_callback *tmp;
 549         struct state_list *slist;
 550         int return_id;
 551
 552         if (argc != 6)
 553                 return 0;
 554
 555         return_id = atoi(argv[0]);
 556         parse_value_ranges_type(get_type(db_info.expr->right), argv[1], &ret_range);
 557         if (!ret_range)
 558                 ret_range = whole_range_list(cur_func_return_type());
 559         type = atoi(argv[2]);
 560         param = atoi(argv[3]);
 561         key = argv[4];
 562         value = argv[5];
 563
 564         if (prev_return_id != -1 && return_id != prev_return_id) {
 565                 slist = __pop_fake_cur_slist();
 566                 merge_slist(&db_info.slist, slist);
 567                 __push_fake_cur_slist();
 568         }
 569         prev_return_id = return_id;
 570
 571         FOR_EACH_PTR(db_return_states_list, tmp) {
 572                 if (tmp->type == type)
 573                         tmp->callback(db_info.expr, param, key, value);
 574         } END_FOR_EACH_PTR(tmp);
 575         ret_range = cast_rl(get_type(db_info.expr->left), ret_range);
 576         set_extra_expr_mod(db_info.expr->left, alloc_estate_range_list(ret_range));
 577
 578         return 0;
 579 }
 580
 581 static int db_return_states_assign(struct expression *expr)
 582 {
 583         struct expression *right;
 584         struct symbol *sym;
 585         struct sm_state *sm;
 586         struct state_list *slist;
 587         static char sql_filter[1024];
 588         int handled = 0;
 589
 590         right = strip_expr(expr->right);
 591         if (right->fn->type != EXPR_SYMBOL || !right->fn->symbol)
 592                 return 0;
 593
 594         sym = right->fn->symbol;
 595         if (!sym)
 596                 return 0;
 597
 598         if (sym->ctype.modifiers & MOD_STATIC) {
 599                 snprintf(sql_filter, 1024,
 600                          "file = '%s' and function = '%s' and static = '1';",
 601                          get_filename(), sym->ident->name);
 602         } else {
 603                 snprintf(sql_filter, 1024,
 604                          "function = '%s' and static = '0';", sym->ident->name);
 605         }
 606
 607         prev_return_id = -1;
 608         db_info.expr = expr;
 609         db_info.slist = NULL;
 610         __push_fake_cur_slist();
 611         run_sql(db_assign_return_states_callback,
 612                 "select return_id, return, type, parameter, key, value from return_states where %s",
 613                 sql_filter);
 614         slist = __pop_fake_cur_slist();
 615         merge_slist(&db_info.slist, slist);
 616
 617         FOR_EACH_PTR(db_info.slist, sm) {
 618                 __set_sm(sm);
 619                 handled = 1;
 620         } END_FOR_EACH_PTR(sm);
 621
 622         return handled;
 623 }
 624
 625 static int handle_implied_return(struct expression *expr)
 626 {
 627         struct range_list *rl;
 628
 629         if (!get_implied_return(expr->right, &rl))
 630                 return 0;
 631         rl = cast_rl(get_type(expr->left), rl);
 632         set_extra_expr_mod(expr->left, alloc_estate_range_list(rl));
 633         return 1;
 634 }
 635
 636 static void match_assign_call(struct expression *expr)
 637 {
 638         struct call_back_list *call_backs;
 639         const char *fn;
 640         struct expression *right;
 641         int handled = 0;
 642
 643         right = strip_expr(expr->right);
 644         if (right->fn->type != EXPR_SYMBOL || !right->fn->symbol) {
 645                 set_extra_expr_mod(expr->left, extra_undefined(get_type(expr->left)));
 646                 return;
 647         }
 648         fn = right->fn->symbol->ident->name;
 649
 650         /*
 651          * some of these conflict (they try to set smatch extra twice), so we
 652          * call them in order from least important to most important.
 653          */
 654
 655         call_backs = search_callback(func_hash, (char *)fn);
 656         call_call_backs(call_backs, ASSIGN_CALL, fn, expr);
 657
 658         handled |= db_return_states_assign(expr);
 659         handled |= db_return_implies_assign(expr);
 660         handled |= assign_ranged_funcs(fn, expr, call_backs);
 661         handled |= handle_implied_return(expr);
 662
 663         if (!handled)
 664                 set_extra_expr_mod(expr->left, extra_undefined(get_type(expr->left)));
 665 }
 666
 667 static int db_return_states_callback(void *unused, int argc, char **argv, char **azColName)
 668 {
 669         struct range_list *ret_range;
 670         int type, param;
 671         char *key, *value;
 672         struct return_implies_callback *tmp;
 673         struct state_list *slist;
 674         int return_id;
 675
 676         if (argc != 6)
 677                 return 0;
 678
 679         return_id = atoi(argv[0]);
 680         parse_value_ranges_type(get_type(db_info.expr), argv[1], &ret_range);
 681         type = atoi(argv[2]);
 682         param = atoi(argv[3]);
 683         key = argv[4];
 684         value = argv[5];
 685
 686         if (prev_return_id != -1 && return_id != prev_return_id) {
 687                 slist = __pop_fake_cur_slist();
 688                 merge_slist(&db_info.slist, slist);
 689                 __push_fake_cur_slist();
 690         }
 691         prev_return_id = return_id;
 692
 693         FOR_EACH_PTR(db_return_states_list, tmp) {
 694                 if (tmp->type == type)
 695                         tmp->callback(db_info.expr, param, key, value);
 696         } END_FOR_EACH_PTR(tmp);
 697
 698         return 0;
 699 }
 700
 701 static void db_return_states(struct expression *expr)
 702 {
 703         struct symbol *sym;
 704         struct sm_state *sm;
 705         struct state_list *slist;
 706         static char sql_filter[1024];
 707
 708         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 709                 return;
 710
 711         sym = expr->fn->symbol;
 712         if (!sym)
 713                 return;
 714
 715         if (sym->ctype.modifiers & MOD_STATIC) {
 716                 snprintf(sql_filter, 1024,
 717                          "file = '%s' and function = '%s' and static = '1';",
 718                          get_filename(), sym->ident->name);
 719         } else {
 720                 snprintf(sql_filter, 1024,
 721                          "function = '%s' and static = '0';", sym->ident->name);
 722         }
 723
 724         prev_return_id = -1;
 725         db_info.expr = expr;
 726         db_info.slist = NULL;
 727         __push_fake_cur_slist();
 728         run_sql(db_return_states_callback,
 729                 "select return_id, return, type, parameter, key, value from return_states where %s",
 730                 sql_filter);
 731         slist = __pop_fake_cur_slist();
 732         merge_slist(&db_info.slist, slist);
 733
 734         FOR_EACH_PTR(db_info.slist, sm) {
 735                 __set_sm(sm);
 736         } END_FOR_EACH_PTR(sm);
 737 }
 738
 739 static int is_assigned_call(struct expression *expr)
 740 {
 741         struct expression *tmp;
 742
 743         FOR_EACH_PTR_REVERSE(big_expression_stack, tmp) {
 744                 if (tmp->type == EXPR_ASSIGNMENT && strip_expr(tmp->right) == expr)
 745                         return 1;
 746                 if (tmp->pos.line < expr->pos.line)
 747                         return 0;
 748         } END_FOR_EACH_PTR_REVERSE(tmp);
 749         return 0;
 750 }
 751
 752 static void db_return_states_call(struct expression *expr)
 753 {
 754         if (is_assigned_call(expr))
 755                 return;
 756         db_return_states(expr);
 757 }
 758
 759 static void match_function_call(struct expression *expr)
 760 {
 761         struct call_back_list *call_backs;
 762
 763         if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol)
 764                 return;
 765         call_backs = search_callback(func_hash, (char *)expr->fn->symbol->ident->name);
 766         if (call_backs)
 767                 call_call_backs(call_backs, REGULAR_CALL,
 768                                 expr->fn->symbol->ident->name, expr);
 769         db_return_states_call(expr);
 770 }
 771
 772 static void match_macro_assign(struct expression *expr)
 773 {
 774         struct call_back_list *call_backs;
 775         const char *macro;
 776         struct expression *right;
 777
 778         right = strip_expr(expr->right);
 779         macro = get_macro_name(right->pos);
 780         call_backs = search_callback(func_hash, (char *)macro);
 781         if (!call_backs)
 782                 return;
 783         call_call_backs(call_backs, MACRO_ASSIGN, macro, expr);
 784         call_call_backs(call_backs, MACRO_ASSIGN_EXTRA, macro, expr);
 785 }
 786
 787 int get_implied_return(struct expression *expr, struct range_list **rl)
 788 {
 789         struct call_back_list *call_backs;
 790         struct fcall_back *tmp;
 791         int handled = 0;
 792         char *fn;
 793
 794         *rl = NULL;
 795
 796         expr = strip_expr(expr);
 797         fn = get_variable_from_expr(expr->fn, NULL);
 798         if (!fn)
 799                 goto out;
 800
 801         call_backs = search_callback(func_hash, fn);
 802
 803         FOR_EACH_PTR(call_backs, tmp) {
 804                 if (tmp->type == IMPLIED_RETURN) {
 805                         (tmp->u.implied_return)(expr, tmp->info, rl);
 806                         handled = 1;
 807                 }
 808         } END_FOR_EACH_PTR(tmp);
 809
 810 out:
 811         free_string(fn);
 812         return handled;
 813 }
 814
 815 void create_function_hook_hash(void)
 816 {
 817         func_hash = create_function_hashtable(5000);
 818 }
 819
 820 void register_function_hooks(int id)
 821 {
 822         add_hook(&match_function_call, FUNCTION_CALL_HOOK);
 823         add_hook(&match_assign_call, CALL_ASSIGNMENT_HOOK);
 824         add_hook(&match_macro_assign, MACRO_ASSIGNMENT_HOOK);
 825 }