smatch_db.c

   1 /*
   2  * smatch/smatch_db.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include <string.h>
  11 #include <errno.h>
  12 #include <sqlite3.h>
  13 #include "smatch.h"
  14 #include "smatch_slist.h"
  15 #include "smatch_extra.h"
  16
  17 #define sql_insert(table, values...)                                            \
  18 do {                                                                            \
  19         if (option_info) {                                                      \
  20                 sm_prefix();                                                    \
  21                 sm_printf("SQL: insert into " #table " values (" values);       \
  22                 sm_printf(");\n");                                              \
  23         }                                                                       \
  24 } while (0)
  25
  26 static sqlite3 *db;
  27
  28 struct def_callback {
  29         int hook_type;
  30         void (*callback)(const char *name, struct symbol *sym, char *key, char *value);
  31 };
  32 ALLOCATOR(def_callback, "definition db hook callbacks");
  33 DECLARE_PTR_LIST(callback_list, struct def_callback);
  34 static struct callback_list *callbacks;
  35
  36 struct member_info_callback {
  37         int owner;
  38         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state);
  39 };
  40 ALLOCATOR(member_info_callback, "caller_info callbacks");
  41 DECLARE_PTR_LIST(member_info_cb_list, struct member_info_callback);
  42 static struct member_info_cb_list *member_callbacks;
  43
  44 struct returned_state_callback {
  45         void (*callback)(int return_id, char *return_ranges, struct expression *return_expr, struct state_list *slist);
  46 };
  47 ALLOCATOR(returned_state_callback, "returned state callbacks");
  48 DECLARE_PTR_LIST(returned_state_cb_list, struct returned_state_callback);
  49 static struct returned_state_cb_list *returned_state_callbacks;
  50
  51 struct returned_member_callback {
  52         int owner;
  53         void (*callback)(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state);
  54 };
  55 ALLOCATOR(returned_member_callback, "returned member callbacks");
  56 DECLARE_PTR_LIST(returned_member_cb_list, struct returned_member_callback);
  57 static struct returned_member_cb_list *returned_member_callbacks;
  58
  59 struct call_implies_callback {
  60         int type;
  61         void (*callback)(struct expression *arg, char *value);
  62 };
  63 ALLOCATOR(call_implies_callback, "call_implies callbacks");
  64 DECLARE_PTR_LIST(call_implies_cb_list, struct call_implies_callback);
  65 static struct call_implies_cb_list *call_implies_cb_list;
  66
  67 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  68 {
  69         char *err = NULL;
  70         int rc;
  71
  72         if (option_no_db || !db)
  73                 return;
  74
  75         rc = sqlite3_exec(db, sql, callback, 0, &err);
  76         if (rc != SQLITE_OK) {
  77                 fprintf(stderr, "SQL error #2: %s\n", err);
  78                 fprintf(stderr, "SQL: '%s'\n", sql);
  79         }
  80 }
  81
  82 void sql_insert_return_states(int return_id, const char *return_ranges,
  83                 int type, int param, const char *key, const char *value)
  84 {
  85         sql_insert(return_states, "'%s', '%s', %d, '%s', %d, %d, %d, '%s', '%s'",
  86                    get_filename(), get_function(), return_id, return_ranges,
  87                    fn_static(), type, param, key, value);
  88 }
  89
  90 void sql_insert_function_ptr(const char *fn, const char *struct_name)
  91 {
  92         sql_insert(function_ptr, "'%s', '%s', '%s'", get_filename(), fn,
  93                    struct_name);
  94 }
  95
  96 void sql_insert_return_values(const char *return_values)
  97 {
  98         sql_insert(return_values, "'%s', '%s', %d, '%s'", get_filename(),
  99                    get_function(), fn_static(), return_values);
 100 }
 101
 102 void sql_insert_call_implies(int type, int param, int value)
 103 {
 104         sql_insert(call_implies, "'%s', '%s', %d, %d, %d, %d", get_filename(),
 105                    get_function(), fn_static(), type, param, value);
 106 }
 107
 108 void sql_insert_type_size(const char *member, int size)
 109 {
 110         sql_insert(type_size, "'%s', '%s', %d", get_filename(), member, size);
 111 }
 112
 113 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
 114 {
 115         struct def_callback *def_callback = __alloc_def_callback(0);
 116
 117         def_callback->hook_type = type;
 118         def_callback->callback = callback;
 119         add_ptr_list(&callbacks, def_callback);
 120 }
 121
 122 /*
 123  * These call backs are used when the --info option is turned on to print struct
 124  * member information.  For example foo->bar could have a state in
 125  * smatch_extra.c and also check_user.c.
 126  */
 127 void add_member_info_callback(int owner, void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 128 {
 129         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
 130
 131         member_callback->owner = owner;
 132         member_callback->callback = callback;
 133         add_ptr_list(&member_callbacks, member_callback);
 134 }
 135
 136 void add_returned_state_callback(void (*fn)(int return_id, char *return_ranges, struct expression *returned_expr, struct state_list *slist))
 137 {
 138         struct returned_state_callback *callback = __alloc_returned_state_callback(0);
 139
 140         callback->callback = fn;
 141         add_ptr_list(&returned_state_callbacks, callback);
 142 }
 143
 144 void add_returned_member_callback(int owner, void (*callback)(int return_id, char *return_ranges, char *printed_name, struct smatch_state *state))
 145 {
 146         struct returned_member_callback *member_callback = __alloc_returned_member_callback(0);
 147
 148         member_callback->owner = owner;
 149         member_callback->callback = callback;
 150         add_ptr_list(&returned_member_callbacks, member_callback);
 151 }
 152
 153 void add_db_fn_call_callback(int type, void (*callback)(struct expression *arg, char *value))
 154 {
 155         struct call_implies_callback *cb = __alloc_call_implies_callback(0);
 156
 157         cb->type = type;
 158         cb->callback = callback;
 159         add_ptr_list(&call_implies_cb_list, cb);
 160 }
 161
 162 static struct symbol *return_type;
 163 static struct range_list *return_range_list;
 164 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
 165 {
 166         if (argc != 1)
 167                 return 0;
 168         if (option_debug)
 169                 sm_msg("return type %d", type_positive_bits(return_type));
 170         str_to_rl(return_type, argv[0], &return_range_list);
 171         return 0;
 172 }
 173
 174 struct range_list *db_return_vals(struct expression *expr)
 175 {
 176         struct symbol *sym;
 177         static char sql_filter[1024];
 178
 179         if (expr->type != EXPR_CALL)
 180                 return NULL;
 181         if (expr->fn->type != EXPR_SYMBOL)
 182                 return NULL;
 183         return_type = get_type(expr);
 184         if (!return_type)
 185                 return NULL;
 186         sym = expr->fn->symbol;
 187         if (!sym)
 188                 return NULL;
 189
 190         if (sym->ctype.modifiers & MOD_STATIC) {
 191                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 192                          get_filename(), sym->ident->name);
 193         } else {
 194                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 195                                 sym->ident->name);
 196         }
 197
 198         return_range_list = NULL;
 199         run_sql(db_return_callback, "select return from return_values where %s",
 200                  sql_filter);
 201         return return_range_list;
 202 }
 203
 204 static void match_call_hack(struct expression *expr)
 205 {
 206         char *name;
 207
 208         /*
 209          * we just want to record something in the database so that if we have
 210          * two calls like:  frob(4); frob(some_unkown); then on the receiving
 211          * side we know that sometimes frob is called with unknown parameters.
 212          */
 213
 214         name = get_fnptr_name(expr->fn);
 215         if (!name)
 216                 return;
 217         sm_msg("info: call_marker '%s' %s", name, is_static(expr->fn) ? "static" : "global");
 218         free_string(name);
 219 }
 220
 221 static void print_struct_members(char *fn, char *global_static, struct expression *expr, int param, struct state_list *slist,
 222         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 223 {
 224         struct sm_state *sm;
 225         char *name;
 226         struct symbol *sym;
 227         int len;
 228         char printed_name[256];
 229         int is_address = 0;
 230
 231         expr = strip_expr(expr);
 232         if (expr->type == EXPR_PREOP && expr->op == '&') {
 233                 expr = strip_expr(expr->unop);
 234                 is_address = 1;
 235         }
 236
 237         name = expr_to_var_sym(expr, &sym);
 238         if (!name || !sym)
 239                 goto free;
 240
 241         len = strlen(name);
 242         FOR_EACH_PTR(slist, sm) {
 243                 if (sm->sym != sym)
 244                         continue;
 245                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 246                         continue;
 247                 if (is_address)
 248                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 249                 else
 250                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 251                 callback(fn, global_static, param, printed_name, sm->state);
 252         } END_FOR_EACH_PTR(sm);
 253 free:
 254         free_string(name);
 255 }
 256
 257 static void match_call_info(struct expression *expr)
 258 {
 259         struct member_info_callback *cb;
 260         struct expression *arg;
 261         struct state_list *slist;
 262         char *name;
 263         int i;
 264         char *gs;
 265
 266         name = get_fnptr_name(expr->fn);
 267         if (!name)
 268                 return;
 269
 270         if (is_static(expr->fn))
 271                 gs = (char *)"static";
 272         else
 273                 gs = (char *)"global";
 274
 275         FOR_EACH_PTR(member_callbacks, cb) {
 276                 slist = get_all_states(cb->owner);
 277                 i = 0;
 278                 FOR_EACH_PTR(expr->args, arg) {
 279                         print_struct_members(name, gs, arg, i, slist, cb->callback);
 280                         i++;
 281                 } END_FOR_EACH_PTR(arg);
 282                 free_slist(&slist);
 283         } END_FOR_EACH_PTR(cb);
 284
 285         free_string(name);
 286 }
 287
 288 static int get_param(int param, char **name, struct symbol **sym)
 289 {
 290         struct symbol *arg;
 291         int i;
 292
 293         i = 0;
 294         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 295                 /*
 296                  * this is a temporary hack to work around a bug (I think in sparse?)
 297                  * 2.6.37-rc1:fs/reiserfs/journal.o
 298                  * If there is a function definition without parameter name found
 299                  * after a function implementation then it causes a crash.
 300                  * int foo() {}
 301                  * int bar(char *);
 302                  */
 303                 if (arg->ident->name < (char *)100)
 304                         continue;
 305                 if (i == param && arg->ident->name) {
 306                         *name = arg->ident->name;
 307                         *sym = arg;
 308                         return TRUE;
 309                 }
 310                 i++;
 311         } END_FOR_EACH_PTR(arg);
 312
 313         return FALSE;
 314 }
 315
 316 static struct state_list *final_states;
 317 static int prev_func_id = -1;
 318 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 319 {
 320         int func_id;
 321         long type;
 322         long param;
 323         char *name = NULL;
 324         struct symbol *sym = NULL;
 325         struct def_callback *def_callback;
 326
 327         if (argc != 5)
 328                 return 0;
 329
 330         func_id = atoi(argv[0]);
 331         errno = 0;
 332         type = strtol(argv[1], NULL, 10);
 333         param = strtol(argv[2], NULL, 10);
 334         if (errno)
 335                 return 0;
 336
 337         if (prev_func_id == -1)
 338                 prev_func_id = func_id;
 339         if (func_id != prev_func_id) {
 340                 merge_slist(&final_states, __pop_fake_cur_slist());
 341                 __push_fake_cur_slist();
 342                 __unnullify_path();
 343                 prev_func_id = func_id;
 344         }
 345
 346         if (type == INTERNAL)
 347                 return 0;
 348         if (param >= 0 && !get_param(param, &name, &sym))
 349                 return 0;
 350
 351         FOR_EACH_PTR(callbacks, def_callback) {
 352                 if (def_callback->hook_type == type)
 353                         def_callback->callback(name, sym, argv[3], argv[4]);
 354         } END_FOR_EACH_PTR(def_callback);
 355
 356         return 0;
 357 }
 358
 359 static void get_direct_callers(struct symbol *sym)
 360 {
 361         char sql_filter[1024];
 362
 363         if (sym->ctype.modifiers & MOD_STATIC) {
 364                 snprintf(sql_filter, 1024,
 365                          "file = '%s' and function = '%s' order by function_id;",
 366                          get_filename(), sym->ident->name);
 367         } else {
 368                 snprintf(sql_filter, 1024,
 369                          "function = '%s' and static = 0 order by function_id;",
 370                          sym->ident->name);
 371         }
 372
 373         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 374                 " where %s", sql_filter);
 375 }
 376
 377 static char *ptr_name;
 378 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 379 {
 380         if (!ptr_name)
 381                 ptr_name = alloc_string(argv[0]);
 382         return 0;
 383 }
 384
 385 static void get_function_pointer_callers(struct symbol *sym)
 386 {
 387         char sql_filter[1024];
 388
 389         if (sym->ctype.modifiers & MOD_STATIC) {
 390                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 391                          get_filename(), sym->ident->name);
 392         } else {
 393                 snprintf(sql_filter, 1024, "function = '%s';",
 394                          sym->ident->name);
 395         }
 396
 397         ptr_name = NULL;
 398         run_sql(get_ptr_name, "select ptr from function_ptr where %s", sql_filter);
 399         if (!ptr_name)
 400                 return;
 401
 402         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 403                 " where function = '%s' order by function_id", ptr_name);
 404
 405         free_string(ptr_name);
 406 }
 407
 408 static void match_data_from_db(struct symbol *sym)
 409 {
 410         struct sm_state *sm;
 411
 412         if (!sym || !sym->ident || !sym->ident->name)
 413                 return;
 414
 415         __push_fake_cur_slist();
 416         __unnullify_path();
 417         prev_func_id = -1;
 418
 419         get_direct_callers(sym);
 420         get_function_pointer_callers(sym);
 421
 422         merge_slist(&final_states, __pop_fake_cur_slist());
 423
 424         FOR_EACH_PTR(final_states, sm) {
 425                 __set_sm(sm);
 426         } END_FOR_EACH_PTR(sm);
 427
 428         free_slist(&final_states);
 429 }
 430
 431 static void match_function_assign(struct expression *expr)
 432 {
 433         struct expression *right = expr->right;
 434         struct symbol *sym;
 435         char *fn_name;
 436         char *ptr_name;
 437
 438         if (right->type == EXPR_PREOP && right->op == '&')
 439                 right = strip_expr(right->unop);
 440         if (right->type != EXPR_SYMBOL)
 441                 return;
 442         sym = get_type(right);
 443         if (!sym || sym->type != SYM_FN)
 444                 return;
 445
 446         fn_name = expr_to_var(right);
 447         ptr_name = get_fnptr_name(expr->left);
 448         if (!fn_name || !ptr_name)
 449                 goto free;
 450
 451         sql_insert_function_ptr(fn_name, ptr_name);
 452
 453 free:
 454         free_string(fn_name);
 455         free_string(ptr_name);
 456 }
 457
 458 static struct expression *call_implies_call_expr;
 459 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 460 {
 461         struct call_implies_callback *cb;
 462         struct expression *arg = NULL;
 463         int type;
 464         int param;
 465
 466         if (argc != 4)
 467                 return 0;
 468
 469         type = atoi(argv[1]);
 470         param = atoi(argv[2]);
 471
 472         FOR_EACH_PTR(call_implies_cb_list, cb) {
 473                 if (cb->type != type)
 474                         continue;
 475                 if (param != -1) {
 476                         arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 477                         if (!arg)
 478                                 continue;
 479                 }
 480                 cb->callback(arg, argv[3]);
 481         } END_FOR_EACH_PTR(cb);
 482
 483         return 0;
 484 }
 485
 486 static void match_call_implies(struct expression *expr)
 487 {
 488         struct symbol *sym;
 489         static char sql_filter[1024];
 490
 491         if (expr->fn->type != EXPR_SYMBOL)
 492                 return;
 493         sym = expr->fn->symbol;
 494         if (!sym)
 495                 return;
 496
 497         if (sym->ctype.modifiers & MOD_STATIC) {
 498                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 499                          get_filename(), sym->ident->name);
 500         } else {
 501                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 502                                 sym->ident->name);
 503         }
 504
 505         call_implies_call_expr = expr;
 506         run_sql(call_implies_callbacks,
 507                 "select function, type, parameter, value from call_implies where %s",
 508                 sql_filter);
 509         return;
 510 }
 511
 512 static void print_initializer_list(struct expression_list *expr_list,
 513                 struct symbol *struct_type)
 514 {
 515         struct expression *expr;
 516         struct symbol *base_type;
 517         char struct_name[256];
 518
 519         FOR_EACH_PTR(expr_list, expr) {
 520                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 521                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 522                         continue;
 523                 }
 524                 if (expr->type != EXPR_IDENTIFIER)
 525                         continue;
 526                 if (!expr->expr_ident)
 527                         continue;
 528                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 529                         continue;
 530                 base_type = get_type(expr->ident_expression);
 531                 if (!base_type || base_type->type != SYM_FN)
 532                         continue;
 533                 snprintf(struct_name, sizeof(struct_name), "(struct %s)->%s",
 534                          struct_type->ident->name, expr->expr_ident->name);
 535                 sql_insert_function_ptr(expr->ident_expression->symbol_name->name,
 536                                         struct_name);
 537         } END_FOR_EACH_PTR(expr);
 538 }
 539
 540 static void global_variable(struct symbol *sym)
 541 {
 542         struct symbol *struct_type;
 543
 544         if (!sym->ident)
 545                 return;
 546         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 547                 return;
 548         struct_type = get_base_type(sym);
 549         if (!struct_type)
 550                 return;
 551         if (struct_type->type == SYM_ARRAY) {
 552                 struct_type = get_base_type(struct_type);
 553                 if (!struct_type)
 554                         return;
 555         }
 556         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 557                 return;
 558         print_initializer_list(sym->initializer->expr_list, struct_type);
 559 }
 560
 561 static void match_return_info(int return_id, char *return_ranges, struct expression *expr, struct state_list *slist)
 562 {
 563         sql_insert_return_states(return_id, return_ranges, INTERNAL, -1, "", "");
 564 }
 565
 566 static int return_id;
 567 static void match_function_def(struct symbol *sym)
 568 {
 569         return_id = 0;
 570 }
 571
 572 static void call_return_state_hooks_compare(struct expression *expr)
 573 {
 574         struct returned_state_callback *cb;
 575         struct state_list *slist;
 576         char *return_ranges;
 577         int final_pass_orig = final_pass;
 578
 579         __push_fake_cur_slist();
 580
 581         final_pass = 0;
 582         __split_whole_condition(expr);
 583         final_pass = final_pass_orig;
 584
 585         return_ranges = alloc_sname("1");
 586
 587         return_id++;
 588         slist = __get_cur_slist();
 589         FOR_EACH_PTR(returned_state_callbacks, cb) {
 590                 cb->callback(return_id, return_ranges, expr, slist);
 591         } END_FOR_EACH_PTR(cb);
 592
 593         __push_true_states();
 594         __use_false_states();
 595
 596         return_ranges = alloc_sname("0");;
 597         return_id++;
 598         slist = __get_cur_slist();
 599         FOR_EACH_PTR(returned_state_callbacks, cb) {
 600                 cb->callback(return_id, return_ranges, expr, slist);
 601         } END_FOR_EACH_PTR(cb);
 602
 603         __merge_true_states();
 604         __pop_fake_cur_slist();
 605 }
 606
 607 static int call_return_state_hooks_split_possible(struct expression *expr)
 608 {
 609         struct returned_state_callback *cb;
 610         struct state_list *slist;
 611         struct range_list *rl;
 612         char *return_ranges;
 613         struct sm_state *sm;
 614         struct sm_state *tmp;
 615         int ret = 0;
 616         int nr_possible, nr_states;
 617
 618         sm = get_sm_state_expr(SMATCH_EXTRA, expr);
 619         if (!sm || !sm->merged)
 620                 return 0;
 621
 622         /* bail if it gets too complicated */
 623         nr_possible = ptr_list_size((struct ptr_list *)sm->possible);
 624         nr_states = ptr_list_size((struct ptr_list *)__get_cur_slist());
 625         if (nr_possible >= 100)
 626                 return 0;
 627         if (nr_states * nr_possible >= 1000)
 628                 return 0;
 629
 630         FOR_EACH_PTR(sm->possible, tmp) {
 631                 if (tmp->merged)
 632                         continue;
 633
 634                 ret = 1;
 635                 __push_fake_cur_slist();
 636
 637                 overwrite_states_using_pool(tmp);
 638
 639                 rl = cast_rl(cur_func_return_type(), estate_rl(tmp->state));
 640                 return_ranges = show_rl(rl);
 641
 642                 return_id++;
 643                 slist = __get_cur_slist();
 644                 FOR_EACH_PTR(returned_state_callbacks, cb) {
 645                         cb->callback(return_id, return_ranges, expr, slist);
 646                 } END_FOR_EACH_PTR(cb);
 647
 648                 __pop_fake_cur_slist();
 649         } END_FOR_EACH_PTR(tmp);
 650
 651         return ret;
 652 }
 653
 654 static void call_return_state_hooks(struct expression *expr)
 655 {
 656         struct returned_state_callback *cb;
 657         struct state_list *slist;
 658         struct range_list *rl;
 659         char *return_ranges;
 660         int nr_states;
 661
 662         expr = strip_expr(expr);
 663
 664         if (!expr) {
 665                 return_ranges = alloc_sname("");
 666         } else if (is_condition(expr)) {
 667                 call_return_state_hooks_compare(expr);
 668                 return;
 669         } else if (call_return_state_hooks_split_possible(expr)) {
 670                 return;
 671         } else if (get_implied_rl(expr, &rl)) {
 672                 rl = cast_rl(cur_func_return_type(), rl);
 673                 return_ranges = show_rl(rl);
 674         } else {
 675                 rl = alloc_whole_rl(cur_func_return_type());
 676                 return_ranges = show_rl(rl);
 677         }
 678
 679         return_id++;
 680         slist = __get_cur_slist();
 681         nr_states = ptr_list_size((struct ptr_list *)__get_cur_slist());
 682         FOR_EACH_PTR(returned_state_callbacks, cb) {
 683                 if (nr_states < 10000)
 684                         cb->callback(return_id, return_ranges, expr, slist);
 685                 else
 686                         cb->callback(return_id, return_ranges, expr, NULL);
 687         } END_FOR_EACH_PTR(cb);
 688 }
 689
 690 static void print_returned_struct_members(int return_id, char *return_ranges, struct expression *expr, struct state_list *slist)
 691 {
 692         struct returned_member_callback *cb;
 693         struct state_list *my_slist;
 694         struct sm_state *sm;
 695         struct symbol *type;
 696         char *name;
 697         char member_name[256];
 698         int len;
 699
 700         type = get_type(expr);
 701         if (!type || type->type != SYM_PTR)
 702                 return;
 703         type = get_real_base_type(type);
 704         if (!type || type->type != SYM_STRUCT)
 705                 return;
 706         name = expr_to_var(expr);
 707         if (!name)
 708                 return;
 709
 710         member_name[sizeof(member_name) - 1] = '\0';
 711         strcpy(member_name, "$$");
 712
 713         len = strlen(name);
 714         FOR_EACH_PTR(returned_member_callbacks, cb) {
 715                 my_slist = get_all_states_slist(cb->owner, slist);
 716                 FOR_EACH_PTR(my_slist, sm) {
 717                         if (strncmp(sm->name, name, len) != 0)
 718                                 continue;
 719                         if (strncmp(sm->name + len, "->", 2) != 0)
 720                                 continue;
 721                         strncpy(member_name + 2, sm->name + len, sizeof(member_name) - 2);
 722                         cb->callback(return_id, return_ranges, member_name, sm->state);
 723                 } END_FOR_EACH_PTR(sm);
 724                 free_slist(&my_slist);
 725         } END_FOR_EACH_PTR(cb);
 726
 727         free_string(name);
 728 }
 729
 730 static void match_end_func_info(struct symbol *sym)
 731 {
 732         if (__path_is_null())
 733                 return;
 734         call_return_state_hooks(NULL);
 735 }
 736
 737 void open_smatch_db(void)
 738 {
 739 #ifdef SQLITE_OPEN_READONLY
 740         int rc;
 741
 742         if (option_no_db)
 743                 return;
 744
 745         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 746         if (rc != SQLITE_OK) {
 747                 option_no_db = 1;
 748                 return;
 749         }
 750         return;
 751 #else
 752         option_no_db = 1;
 753         return;
 754 #endif
 755 }
 756
 757 void register_definition_db_callbacks(int id)
 758 {
 759         add_hook(&match_function_def, FUNC_DEF_HOOK);
 760
 761         if (option_info) {
 762                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 763                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 764                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 765                 add_hook(&match_function_assign, GLOBAL_ASSIGNMENT_HOOK);
 766                 add_hook(&global_variable, BASE_HOOK);
 767                 add_hook(&global_variable, DECLARATION_HOOK);
 768                 add_returned_state_callback(match_return_info);
 769                 add_returned_state_callback(print_returned_struct_members);
 770                 add_hook(&call_return_state_hooks, RETURN_HOOK);
 771                 add_hook(&match_end_func_info, END_FUNC_HOOK);
 772         }
 773
 774         if (option_no_db)
 775                 return;
 776
 777         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 778         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 779 }
 780
 781 char *get_variable_from_key(struct expression *arg, char *key, struct symbol **sym)
 782 {
 783         char buf[256];
 784         char *tmp;
 785
 786         if (strcmp(key, "$$") == 0)
 787                 return expr_to_var_sym(arg, sym);
 788
 789         if (strcmp(key, "*$$") == 0) {
 790                 if (arg->type == EXPR_PREOP && arg->op == '&') {
 791                         arg = strip_expr(arg->unop);
 792                         return expr_to_var_sym(arg, sym);
 793                 } else {
 794                         tmp = expr_to_var_sym(arg, sym);
 795                         if (!tmp)
 796                                 return NULL;
 797                         snprintf(buf, sizeof(buf), "*%s", tmp);
 798                         free_string(tmp);
 799                         return alloc_string(buf);
 800                 }
 801         }
 802
 803         if (arg->type == EXPR_PREOP && arg->op == '&') {
 804                 arg = strip_expr(arg->unop);
 805                 tmp = expr_to_var_sym(arg, sym);
 806                 if (!tmp)
 807                         return NULL;
 808                 snprintf(buf, sizeof(buf), "%s.%s", tmp, key + 4);
 809                 return alloc_string(buf);
 810         }
 811
 812         tmp = expr_to_var_sym(arg, sym);
 813         if (!tmp)
 814                 return NULL;
 815         snprintf(buf, sizeof(buf), "%s%s", tmp, key + 2);
 816         free_string(tmp);
 817         return alloc_string(buf);
 818 }
 819
 820