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 static sqlite3 *db;
  18
  19 struct def_callback {
  20         int hook_type;
  21         void (*callback)(const char *name, struct symbol *sym, char *key, char *value);
  22 };
  23 ALLOCATOR(def_callback, "definition db hook callbacks");
  24 DECLARE_PTR_LIST(callback_list, struct def_callback);
  25 static struct callback_list *callbacks;
  26
  27 struct member_info_callback {
  28         int owner;
  29         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state);
  30 };
  31 ALLOCATOR(member_info_callback, "caller_info callbacks");
  32 DECLARE_PTR_LIST(member_info_cb_list, struct member_info_callback);
  33 static struct member_info_cb_list *member_callbacks;
  34
  35 struct call_implies_callback {
  36         int type;
  37         void (*callback)(struct expression *arg, char *value);
  38 };
  39 ALLOCATOR(call_implies_callback, "call_implies callbacks");
  40 DECLARE_PTR_LIST(call_implies_cb_list, struct call_implies_callback);
  41 static struct call_implies_cb_list *call_implies_cb_list;
  42
  43 static int return_id;
  44 int get_return_id(void)
  45 {
  46         return return_id;
  47 }
  48
  49 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  50 {
  51         char *err = NULL;
  52         int rc;
  53
  54         if (option_no_db || !db)
  55                 return;
  56
  57         rc = sqlite3_exec(db, sql, callback, 0, &err);
  58         if (rc != SQLITE_OK) {
  59                 fprintf(stderr, "SQL error #2: %s\n", err);
  60                 fprintf(stderr, "SQL: '%s'\n", sql);
  61         }
  62 }
  63
  64 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  65 {
  66         struct def_callback *def_callback = __alloc_def_callback(0);
  67
  68         def_callback->hook_type = type;
  69         def_callback->callback = callback;
  70         add_ptr_list(&callbacks, def_callback);
  71 }
  72
  73 /*
  74  * These call backs are used when the --info option is turned on to print struct
  75  * member information.  For example foo->bar could have a state in
  76  * smatch_extra.c and also check_user.c.
  77  */
  78 void add_member_info_callback(int owner, void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
  79 {
  80         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  81
  82         member_callback->owner = owner;
  83         member_callback->callback = callback;
  84         add_ptr_list(&member_callbacks, member_callback);
  85 }
  86
  87 void add_db_fn_call_callback(int type, void (*callback)(struct expression *arg, char *value))
  88 {
  89         struct call_implies_callback *cb = __alloc_call_implies_callback(0);
  90
  91         cb->type = type;
  92         cb->callback = callback;
  93         add_ptr_list(&call_implies_cb_list, cb);
  94 }
  95
  96 static struct symbol *return_type;
  97 static struct range_list *return_range_list;
  98 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
  99 {
 100         if (argc != 1)
 101                 return 0;
 102         if (option_debug)
 103                 sm_msg("return type %d", type_positive_bits(return_type));
 104         parse_value_ranges_type(return_type, argv[0], &return_range_list);
 105         return 0;
 106 }
 107
 108 struct range_list *db_return_vals(struct expression *expr)
 109 {
 110         struct symbol *sym;
 111         static char sql_filter[1024];
 112
 113         if (expr->type != EXPR_CALL)
 114                 return NULL;
 115         if (expr->fn->type != EXPR_SYMBOL)
 116                 return NULL;
 117         return_type = get_type(expr);
 118         if (!return_type)
 119                 return NULL;
 120         sym = expr->fn->symbol;
 121         if (!sym)
 122                 return NULL;
 123
 124         if (sym->ctype.modifiers & MOD_STATIC) {
 125                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 126                          get_filename(), sym->ident->name);
 127         } else {
 128                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 129                                 sym->ident->name);
 130         }
 131
 132         return_range_list = NULL;
 133         run_sql(db_return_callback, "select return from return_values where %s",
 134                  sql_filter);
 135         return return_range_list;
 136 }
 137
 138 static void match_call_hack(struct expression *expr)
 139 {
 140         char *name;
 141
 142         /*
 143          * we just want to record something in the database so that if we have
 144          * two calls like:  frob(4); frob(some_unkown); then on the receiving
 145          * side we know that sometimes frob is called with unknown parameters.
 146          */
 147
 148         name = get_fnptr_name(expr->fn);
 149         if (!name)
 150                 return;
 151         sm_msg("info: call_marker '%s' %s", name, is_static(expr->fn) ? "static" : "global");
 152         free_string(name);
 153 }
 154
 155 static void print_struct_members(char *fn, char *global_static, struct expression *expr, int param, struct state_list *slist,
 156         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 157 {
 158         struct sm_state *sm;
 159         char *name;
 160         struct symbol *sym;
 161         int len;
 162         char printed_name[256];
 163         int is_address = 0;
 164
 165         expr = strip_expr(expr);
 166         if (expr->type == EXPR_PREOP && expr->op == '&') {
 167                 expr = strip_expr(expr->unop);
 168                 is_address = 1;
 169         }
 170
 171         name = get_variable_from_expr(expr, &sym);
 172         if (!name || !sym)
 173                 goto free;
 174
 175         len = strlen(name);
 176         FOR_EACH_PTR(slist, sm) {
 177                 if (sm->sym != sym)
 178                         continue;
 179                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 180                         continue;
 181                 if (is_address)
 182                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 183                 else
 184                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 185                 callback(fn, global_static, param, printed_name, sm->state);
 186         } END_FOR_EACH_PTR(sm);
 187 free:
 188         free_string(name);
 189 }
 190
 191 static void match_call_info(struct expression *expr)
 192 {
 193         struct member_info_callback *cb;
 194         struct expression *arg;
 195         struct state_list *slist;
 196         char *name;
 197         int i;
 198         char *gs;
 199
 200         name = get_fnptr_name(expr->fn);
 201         if (!name)
 202                 return;
 203
 204         if (is_static(expr->fn))
 205                 gs = (char *)"static";
 206         else
 207                 gs = (char *)"global";
 208
 209         FOR_EACH_PTR(member_callbacks, cb) {
 210                 slist = get_all_states(cb->owner);
 211                 i = 0;
 212                 FOR_EACH_PTR(expr->args, arg) {
 213                         print_struct_members(name, gs, arg, i, slist, cb->callback);
 214                         i++;
 215                 } END_FOR_EACH_PTR(arg);
 216         } END_FOR_EACH_PTR(cb);
 217
 218         free_string(name);
 219         free_slist(&slist);
 220 }
 221
 222 static int get_param(int param, char **name, struct symbol **sym)
 223 {
 224         struct symbol *arg;
 225         int i;
 226
 227         i = 0;
 228         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 229                 /*
 230                  * this is a temporary hack to work around a bug (I think in sparse?)
 231                  * 2.6.37-rc1:fs/reiserfs/journal.o
 232                  * If there is a function definition without parameter name found
 233                  * after a function implementation then it causes a crash.
 234                  * int foo() {}
 235                  * int bar(char *);
 236                  */
 237                 if (arg->ident->name < (char *)100)
 238                         continue;
 239                 if (i == param && arg->ident->name) {
 240                         *name = arg->ident->name;
 241                         *sym = arg;
 242                         return TRUE;
 243                 }
 244                 i++;
 245         } END_FOR_EACH_PTR(arg);
 246
 247         return FALSE;
 248 }
 249
 250 static struct state_list *final_states;
 251 static int prev_func_id = -1;
 252 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 253 {
 254         int func_id;
 255         long type;
 256         long param;
 257         char *name = NULL;
 258         struct symbol *sym = NULL;
 259         struct def_callback *def_callback;
 260
 261         if (argc != 5)
 262                 return 0;
 263
 264         func_id = atoi(argv[0]);
 265         errno = 0;
 266         type = strtol(argv[1], NULL, 10);
 267         param = strtol(argv[2], NULL, 10);
 268         if (errno)
 269                 return 0;
 270
 271         if (prev_func_id == -1)
 272                 prev_func_id = func_id;
 273         if (func_id != prev_func_id) {
 274                 merge_slist(&final_states, __pop_fake_cur_slist());
 275                 __push_fake_cur_slist();
 276                 __unnullify_path();
 277                 prev_func_id = func_id;
 278         }
 279
 280         if (type == INTERNAL)
 281                 return 0;
 282         if (param >= 0 && !get_param(param, &name, &sym))
 283                 return 0;
 284
 285         FOR_EACH_PTR(callbacks, def_callback) {
 286                 if (def_callback->hook_type == type)
 287                         def_callback->callback(name, sym, argv[3], argv[4]);
 288         } END_FOR_EACH_PTR(def_callback);
 289
 290         return 0;
 291 }
 292
 293 static void get_direct_callers(struct symbol *sym)
 294 {
 295         char sql_filter[1024];
 296
 297         if (sym->ctype.modifiers & MOD_STATIC) {
 298                 snprintf(sql_filter, 1024,
 299                          "file = '%s' and function = '%s' order by function_id;",
 300                          get_filename(), sym->ident->name);
 301         } else {
 302                 snprintf(sql_filter, 1024,
 303                          "function = '%s' and static = 0 order by function_id;",
 304                          sym->ident->name);
 305         }
 306
 307         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 308                 " where %s", sql_filter);
 309 }
 310
 311 static char *ptr_name;
 312 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 313 {
 314         if (!ptr_name)
 315                 ptr_name = alloc_string(argv[0]);
 316         return 0;
 317 }
 318
 319 static void get_function_pointer_callers(struct symbol *sym)
 320 {
 321         ptr_name = NULL;
 322         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 323                 sym->ident->name);
 324         if (!ptr_name)
 325                 return;
 326
 327         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 328                 " where function = '%s' order by function_id", ptr_name);
 329 }
 330
 331 static void match_data_from_db(struct symbol *sym)
 332 {
 333         struct sm_state *sm;
 334
 335         if (!sym || !sym->ident || !sym->ident->name)
 336                 return;
 337
 338         __push_fake_cur_slist();
 339         __unnullify_path();
 340         prev_func_id = -1;
 341
 342         get_direct_callers(sym);
 343         get_function_pointer_callers(sym);
 344
 345         merge_slist(&final_states, __pop_fake_cur_slist());
 346
 347         FOR_EACH_PTR(final_states, sm) {
 348                 __set_sm(sm);
 349         } END_FOR_EACH_PTR(sm);
 350
 351         free_slist(&final_states);
 352 }
 353
 354 static void match_function_assign(struct expression *expr)
 355 {
 356         struct expression *right = expr->right;
 357         struct symbol *sym;
 358         char *fn_name;
 359         char *ptr_name;
 360
 361         if (right->type == EXPR_PREOP && right->op == '&')
 362                 right = right->unop;
 363         if (right->type != EXPR_SYMBOL)
 364                 return;
 365         sym = get_type(right);
 366         if (!sym || sym->type != SYM_FN)
 367                 return;
 368
 369         fn_name = get_variable_from_expr(right, NULL);
 370         ptr_name = get_fnptr_name(expr->left);
 371         if (!fn_name || !ptr_name)
 372                 goto free;
 373
 374         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 375
 376 free:
 377         free_string(fn_name);
 378         free_string(ptr_name);
 379 }
 380
 381 static struct expression *call_implies_call_expr;
 382 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 383 {
 384         struct call_implies_callback *cb;
 385         struct expression *arg = NULL;
 386         int type;
 387         int param;
 388
 389         if (argc != 4)
 390                 return 0;
 391
 392         type = atoi(argv[1]);
 393         param = atoi(argv[2]);
 394
 395         FOR_EACH_PTR(call_implies_cb_list, cb) {
 396                 if (cb->type != type)
 397                         continue;
 398                 if (param != -1) {
 399                         arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 400                         if (!arg)
 401                                 continue;
 402                 }
 403                 cb->callback(arg, argv[3]);
 404         } END_FOR_EACH_PTR(cb);
 405
 406         return 0;
 407 }
 408
 409 static void match_call_implies(struct expression *expr)
 410 {
 411         struct symbol *sym;
 412         static char sql_filter[1024];
 413
 414         if (expr->fn->type != EXPR_SYMBOL)
 415                 return;
 416         sym = expr->fn->symbol;
 417         if (!sym)
 418                 return;
 419
 420         if (sym->ctype.modifiers & MOD_STATIC) {
 421                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 422                          get_filename(), sym->ident->name);
 423         } else {
 424                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 425                                 sym->ident->name);
 426         }
 427
 428         call_implies_call_expr = expr;
 429         run_sql(call_implies_callbacks,
 430                 "select function, type, parameter, value from call_implies where %s",
 431                 sql_filter);
 432         return;
 433 }
 434
 435 static void print_initializer_list(struct expression_list *expr_list,
 436                 struct symbol *struct_type)
 437 {
 438         struct expression *expr;
 439         struct symbol *base_type;
 440
 441         FOR_EACH_PTR(expr_list, expr) {
 442                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 443                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 444                         continue;
 445                 }
 446                 if (expr->type != EXPR_IDENTIFIER)
 447                         continue;
 448                 if (!expr->expr_ident)
 449                         continue;
 450                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 451                         continue;
 452                 base_type = get_type(expr->ident_expression);
 453                 if (!base_type || base_type->type != SYM_FN)
 454                         continue;
 455                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 456                        expr->expr_ident->name,
 457                        expr->ident_expression->symbol_name->name);
 458         } END_FOR_EACH_PTR(expr);
 459 }
 460
 461 static void global_variable(struct symbol *sym)
 462 {
 463         struct symbol *struct_type;
 464
 465         if (!sym->ident)
 466                 return;
 467         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 468                 return;
 469         struct_type = get_base_type(sym);
 470         if (!struct_type)
 471                 return;
 472         if (struct_type->type == SYM_ARRAY) {
 473                 struct_type = get_base_type(struct_type);
 474                 if (!struct_type)
 475                         return;
 476         }
 477         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 478                 return;
 479         print_initializer_list(sym->initializer->expr_list, struct_type);
 480 }
 481
 482 static void match_return_info(struct expression *ret_value)
 483 {
 484         struct range_list *rl;
 485
 486         get_implied_range_list(ret_value, &rl);
 487         rl = cast_rl(cur_func_return_type(), rl);
 488         sm_msg("info: return_marker %d '%s' %s",
 489                get_return_id(), show_ranges(rl), global_static());
 490 }
 491
 492 static void match_end_func_info(struct symbol *sym)
 493 {
 494         if (__path_is_null())
 495                 return;
 496         sm_msg("info: return_marker %d '' %s", get_return_id(), global_static());
 497 }
 498
 499 static void match_function_def(struct symbol *sym)
 500 {
 501         return_id = 0;
 502 }
 503
 504 static void match_return(struct expression *ret_value)
 505 {
 506         return_id++;
 507 }
 508
 509 static void match_end_func(struct symbol *sym)
 510 {
 511         return_id++;
 512 }
 513
 514 void open_smatch_db(void)
 515 {
 516 #ifdef SQLITE_OPEN_READONLY
 517         int rc;
 518
 519         if (option_no_db)
 520                 return;
 521
 522         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 523         if (rc != SQLITE_OK) {
 524                 option_no_db = 1;
 525                 return;
 526         }
 527         return;
 528 #else
 529         option_no_db = 1;
 530         return;
 531 #endif
 532 }
 533
 534 void register_definition_db_callbacks(int id)
 535 {
 536         add_hook(&match_function_def, FUNC_DEF_HOOK);
 537         add_hook(&match_return, RETURN_HOOK);
 538         add_hook(&match_end_func, END_FUNC_HOOK);
 539
 540         if (option_info) {
 541                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 542                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 543                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 544                 add_hook(&global_variable, BASE_HOOK);
 545                 add_hook(&global_variable, DECLARATION_HOOK);
 546                 add_hook(&match_return_info, RETURN_HOOK);
 547                 add_hook(&match_end_func_info, END_FUNC_HOOK);
 548         }
 549
 550         if (option_no_db)
 551                 return;
 552
 553         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 554         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 555 }