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, 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 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  36 {
  37         char *err = NULL;
  38         int rc;
  39
  40         if (option_no_db || !db)
  41                 return;
  42
  43         rc = sqlite3_exec(db, sql, callback, 0, &err);
  44         if (rc != SQLITE_OK)
  45                 fprintf(stderr, "SQL error #2: %s\n", err);
  46 }
  47
  48 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  49 {
  50         struct def_callback *def_callback = __alloc_def_callback(0);
  51
  52         def_callback->hook_type = type;
  53         def_callback->callback = callback;
  54         add_ptr_list(&callbacks, def_callback);
  55 }
  56
  57 void add_member_info_callback(int owner, void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state))
  58 {
  59         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  60
  61         member_callback->owner = owner;
  62         member_callback->callback = callback;
  63         add_ptr_list(&member_callbacks, member_callback);
  64 }
  65
  66 static struct range_list *return_range_list;
  67 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
  68 {
  69         struct range_list *rl = NULL;
  70
  71         if (argc != 1)
  72                 return 0;
  73
  74         get_value_ranges(argv[0], &rl);
  75         return_range_list = range_list_union(return_range_list, rl);
  76
  77         return 0;
  78 }
  79
  80 struct range_list *db_return_vals(struct expression *expr)
  81 {
  82         struct symbol *sym;
  83         static char sql_filter[1024];
  84
  85         if (expr->type != EXPR_CALL)
  86                 return NULL;
  87         if (expr->fn->type != EXPR_SYMBOL)
  88                 return NULL;
  89         sym = expr->fn->symbol;
  90         if (!sym)
  91                 return NULL;
  92
  93         if (sym->ctype.modifiers & MOD_STATIC) {
  94                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
  95                          get_filename(), sym->ident->name);
  96         } else {
  97                 snprintf(sql_filter, 1024, "function = '%s';", sym->ident->name);
  98         }
  99
 100         return_range_list = NULL;
 101         run_sql(db_return_callback, "select value from return_info where %s",
 102                  sql_filter);
 103         return return_range_list;
 104 }
 105
 106 static void match_call_hack(struct expression *expr)
 107 {
 108         char *name;
 109
 110         /*
 111          * we just want to record something in the database so that if we have
 112          * two calls like:  frob(4); frob(some_unkown); then on the recieving
 113          * side we know that sometimes frob is called with unknown parameters.
 114          */
 115
 116         name = get_fnptr_name(expr->fn);
 117         if (!name)
 118                 return;
 119         if (ptr_list_empty(expr->args))
 120                 return;
 121         sm_msg("info: passes param_value '%s' -1 '$$' min-max", name);
 122         free_string(name);
 123 }
 124
 125 static void print_struct_members(char *fn, struct expression *expr, int param, struct state_list *slist,
 126         void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state))
 127 {
 128         struct sm_state *sm;
 129         char *name;
 130         struct symbol *sym;
 131         int len;
 132         char printed_name[256];
 133         int is_address = 0;
 134
 135         expr = strip_expr(expr);
 136         if (expr->type == EXPR_PREOP && expr->op == '&') {
 137                 expr = strip_expr(expr->unop);
 138                 is_address = 1;
 139         }
 140
 141         name = get_variable_from_expr(expr, &sym);
 142         if (!name || !sym)
 143                 goto free;
 144
 145         len = strlen(name);
 146         FOR_EACH_PTR(slist, sm) {
 147                 if (sm->sym != sym)
 148                         continue;
 149                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 150                         continue;
 151                 if (is_address)
 152                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 153                 else
 154                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 155                 callback(fn, param, printed_name, sm->state);
 156         } END_FOR_EACH_PTR(sm);
 157 free:
 158         free_string(name);
 159 }
 160
 161 static void match_call_info(struct expression *expr)
 162 {
 163         struct member_info_callback *cb;
 164         struct expression *arg;
 165         struct state_list *slist;
 166         char *name;
 167         int i;
 168
 169         name = get_fnptr_name(expr->fn);
 170         if (!name)
 171                 return;
 172
 173         FOR_EACH_PTR(member_callbacks, cb) {
 174                 slist = get_all_states(cb->owner);
 175                 i = 0;
 176                 FOR_EACH_PTR(expr->args, arg) {
 177                         print_struct_members(name, arg, i, slist, cb->callback);
 178                         i++;
 179                 } END_FOR_EACH_PTR(arg);
 180         } END_FOR_EACH_PTR(cb);
 181
 182         free_string(name);
 183         free_slist(&slist);
 184 }
 185
 186 static int get_param(int param, char **name, struct symbol **sym)
 187 {
 188         struct symbol *arg;
 189         int i;
 190
 191         i = 0;
 192         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 193                 /*
 194                  * this is a temporary hack to work around a bug (I think in sparse?)
 195                  * 2.6.37-rc1:fs/reiserfs/journal.o
 196                  * If there is a function definition without parameter name found
 197                  * after a function implementation then it causes a crash.
 198                  * int foo() {}
 199                  * int bar(char *);
 200                  */
 201                 if (arg->ident->name < (char *)100)
 202                         continue;
 203                 if (i == param && arg->ident->name) {
 204                         *name = arg->ident->name;
 205                         *sym = arg;
 206                         return TRUE;
 207                 }
 208                 i++;
 209         } END_FOR_EACH_PTR(arg);
 210
 211         return FALSE;
 212 }
 213
 214 static struct state_list *final_states;
 215 static int prev_func_id = -1;
 216 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 217 {
 218         int func_id;
 219         long type;
 220         long param;
 221         char *name;
 222         struct symbol *sym;
 223         struct def_callback *def_callback;
 224
 225         if (argc != 5)
 226                 return 0;
 227
 228         func_id = atoi(argv[0]);
 229         errno = 0;
 230         type = strtol(argv[1], NULL, 10);
 231         param = strtol(argv[2], NULL, 10);
 232         if (errno)
 233                 return 0;
 234
 235         if (prev_func_id == -1)
 236                 prev_func_id = func_id;
 237         if (func_id != prev_func_id) {
 238                 merge_slist(&final_states, __pop_fake_cur_slist());
 239                 __push_fake_cur_slist();
 240                 __unnullify_path();
 241                 prev_func_id = func_id;
 242         }
 243
 244         if (param == -1 || !get_param(param, &name, &sym))
 245                 return 0;
 246
 247         FOR_EACH_PTR(callbacks, def_callback) {
 248                 if (def_callback->hook_type == type)
 249                         def_callback->callback(name, sym, argv[3], argv[4]);
 250         } END_FOR_EACH_PTR(def_callback);
 251
 252         return 0;
 253 }
 254
 255 static void get_direct_callers(struct symbol *sym)
 256 {
 257         char sql_filter[1024];
 258
 259         if (sym->ctype.modifiers & MOD_STATIC) {
 260                 snprintf(sql_filter, 1024,
 261                          "file = '%s' and function = '%s' order by function_id;",
 262                          get_filename(), sym->ident->name);
 263         } else {
 264                 snprintf(sql_filter, 1024,
 265                          "function = '%s' order by function_id;",
 266                          sym->ident->name);
 267         }
 268
 269         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 270                 " where %s", sql_filter);
 271 }
 272
 273 static char *ptr_name;
 274 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 275 {
 276         if (!ptr_name)
 277                 ptr_name = alloc_string(argv[0]);
 278         return 0;
 279 }
 280
 281 static void get_function_pointer_callers(struct symbol *sym)
 282 {
 283         ptr_name = NULL;
 284         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 285                 sym->ident->name);
 286         if (!ptr_name)
 287                 return;
 288
 289         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 290                 " where function = '%s' order by function_id", ptr_name);
 291 }
 292
 293 static void match_data_from_db(struct symbol *sym)
 294 {
 295         struct sm_state *sm;
 296
 297         if (!sym || !sym->ident || !sym->ident->name)
 298                 return;
 299
 300         __push_fake_cur_slist();
 301         __unnullify_path();
 302         prev_func_id = -1;
 303
 304         get_direct_callers(sym);
 305         get_function_pointer_callers(sym);
 306
 307         merge_slist(&final_states, __pop_fake_cur_slist());
 308
 309         FOR_EACH_PTR(final_states, sm) {
 310                 __set_sm(sm);
 311         } END_FOR_EACH_PTR(sm);
 312
 313         free_slist(&final_states);
 314 }
 315
 316 static void match_function_assign(struct expression *expr)
 317 {
 318         struct expression *right = expr->right;
 319         struct symbol *sym;
 320         char *fn_name;
 321         char *ptr_name;
 322
 323         if (right->type == EXPR_PREOP && right->op == '&')
 324                 right = right->unop;
 325         if (right->type != EXPR_SYMBOL)
 326                 return;
 327         sym = get_type(right);
 328         if (!sym || sym->type != SYM_FN)
 329                 return;
 330
 331         fn_name = get_variable_from_expr(right, NULL);
 332         ptr_name = get_fnptr_name(expr->left);
 333         if (!fn_name || !ptr_name)
 334                 goto free;
 335
 336         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 337
 338 free:
 339         free_string(fn_name);
 340         free_string(ptr_name);
 341 }
 342
 343 static void print_initializer_list(struct expression_list *expr_list,
 344                 struct symbol *struct_type)
 345 {
 346         struct expression *expr;
 347         struct symbol *base_type;
 348
 349         FOR_EACH_PTR(expr_list, expr) {
 350                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 351                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 352                         continue;
 353                 }
 354                 if (expr->type != EXPR_IDENTIFIER)
 355                         continue;
 356                 if (!expr->expr_ident)
 357                         continue;
 358                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 359                         continue;
 360                 base_type = get_type(expr->ident_expression);
 361                 if (!base_type || base_type->type != SYM_FN)
 362                         continue;
 363                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 364                        expr->expr_ident->name,
 365                        expr->ident_expression->symbol_name->name);
 366         } END_FOR_EACH_PTR(expr);
 367
 368 }
 369
 370 static void global_variable(struct symbol *sym)
 371 {
 372         struct symbol *struct_type;
 373
 374         if (!sym->ident)
 375                 return;
 376         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 377                 return;
 378         struct_type = get_base_type(sym);
 379         if (!struct_type)
 380                 return;
 381         if (struct_type->type == SYM_ARRAY) {
 382                 struct_type = get_base_type(struct_type);
 383                 if (!struct_type)
 384                         return;
 385         }
 386         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 387                 return;
 388         print_initializer_list(sym->initializer->expr_list, struct_type);
 389 }
 390
 391 void open_smatch_db(void)
 392 {
 393 #ifdef SQLITE_OPEN_READONLY
 394         int rc;
 395
 396         if (option_no_db)
 397                 return;
 398
 399         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 400         if (rc != SQLITE_OK) {
 401                 option_no_db = 1;
 402                 return;
 403         }
 404         return;
 405 #else
 406         option_no_db = 1;
 407         return;
 408 #endif
 409 }
 410
 411 void register_definition_db_callbacks(int id)
 412 {
 413         if (option_info) {
 414                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 415                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 416                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 417                 add_hook(&global_variable, BASE_HOOK);
 418                 add_hook(&global_variable, DECLARATION_HOOK);
 419         }
 420
 421         if (option_no_db)
 422                 return;
 423
 424         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 425 }