smatch_function_hooks.c

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