1 /* 2 * Copyright (C) 2010 Dan Carpenter. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt 16 */ 17 18 /* 19 * Some macros don't return NULL pointers. Complain if people 20 * check the results for NULL because obviously the programmers 21 * don't know what the pants they're doing. 22 */ 23 24 #include "smatch.h" 25 26 static int my_id; 27 28 STATE(non_null); 29 30 static void is_ok(struct sm_state *sm, struct expression *mod_expr) 31 { 32 set_state(my_id, sm->name, sm->sym, &undefined); 33 } 34 35 static void match_non_null(const char *fn, struct expression *expr, void *unused) 36 { 37 set_state_expr(my_id, expr->left, &non_null); 38 } 39 40 static void match_condition(struct expression *expr) 41 { 42 if (__in_pre_condition) 43 return; 44 45 if (get_macro_name(expr->pos)) 46 return; 47 48 if (get_state_expr(my_id, expr) == &non_null) { 49 char *name; 50 51 name = expr_to_var(expr); 52 sm_warning("can '%s' even be NULL?", name); 53 set_state_expr(my_id, expr, &undefined); 54 free_string(name); 55 } 56 } 57 58 void check_container_of(int id) 59 { 60 if (option_project != PROJ_KERNEL) 61 return; 62 63 my_id = id; 64 add_macro_assign_hook("container_of", &match_non_null, NULL); 65 add_macro_assign_hook("list_first_entry", &match_non_null, NULL); 66 add_function_assign_hook("nla_data", &match_non_null, NULL); 67 add_modification_hook(my_id, &is_ok); 68 add_hook(&match_condition, CONDITION_HOOK); 69 } 70