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