check_dereferences_param.c

   1 /*
   2  * Copyright (C) 2012 Oracle.
   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  * This is an --info recipe.  The goal is to print a message for every parameter
  20  * which we can not avoid dereferencing.  This is maybe a bit restrictive but it
  21  * avoids some false positives.
  22  */
  23
  24 #include "smatch.h"
  25 #include "smatch_extra.h"
  26 #include "smatch_slist.h"
  27
  28 static int my_id;
  29
  30 STATE(derefed);
  31
  32 static void process_states(void)
  33 {
  34         struct sm_state *tmp;
  35         int arg;
  36         const char *name;
  37
  38         FOR_EACH_MY_SM(my_id, __get_cur_stree(), tmp) {
  39                 if (tmp->state != &derefed)
  40                         continue;
  41                 arg = get_param_num_from_sym(tmp->sym);
  42                 if (arg < 0)
  43                         continue;
  44                 name = get_param_name(tmp);
  45                 if (!name || name[0] == '&')
  46                         continue;
  47                 sql_insert_return_implies(DEREFERENCE, arg, name, "1");
  48         } END_FOR_EACH_SM(tmp);
  49 }
  50
  51 static void deref_hook(struct expression *expr)
  52 {
  53         char *param_name = NULL;
  54         struct symbol *sym, *param_sym;
  55         char *name;
  56
  57         name = expr_to_var_sym(expr, &sym);
  58         if (!name)
  59                 return;
  60
  61         param_name = get_param_var_sym_var_sym(name, sym, NULL, &param_sym);
  62         if (!param_name || !param_sym)
  63                 goto free;
  64         if (get_param_num_from_sym(param_sym) < 0)
  65                 goto free;
  66         if (param_was_set_var_sym(param_name, param_sym))
  67                 goto free;
  68
  69         set_state(my_id, param_name, param_sym, &derefed);
  70 free:
  71         free_string(name);
  72 }
  73
  74 void check_dereferences_param(int id)
  75 {
  76         my_id = id;
  77
  78         add_dereference_hook(deref_hook);
  79         all_return_states_hook(&process_states);
  80 }