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