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