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