smatch_param_used.c

   1 /*
   2  * Copyright (C) 2015 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 #include "smatch.h"
  19 #include "smatch_slist.h"
  20
  21 static int my_id;
  22 int __ignore_param_used;
  23
  24 static struct stree *used_stree;
  25
  26 STATE(used);
  27
  28 static void get_state_hook(int owner, const char *name, struct symbol *sym)
  29 {
  30         int arg;
  31
  32         if (!option_info)
  33                 return;
  34
  35         if (__ignore_param_used ||
  36             __in_fake_assign ||
  37             __in_fake_parameter_assign ||
  38             __in_function_def ||
  39             __in_unmatched_hook)
  40                 return;
  41
  42         arg = get_param_num_from_sym(sym);
  43         if (arg < 0)
  44                 return;
  45         if (param_was_set_var_sym(name, sym))
  46                 return;
  47         set_state_stree(&used_stree, my_id, name, sym, &used);
  48 }
  49
  50 static void set_param_used(struct expression *call, struct expression *arg, char *key, char *unused)
  51 {
  52         struct symbol *sym;
  53         char *name;
  54         int arg_nr;
  55
  56         if (!option_info)
  57                 return;
  58
  59         name = get_variable_from_key(arg, key, &sym);
  60         if (!name || !sym)
  61                 goto free;
  62
  63         arg_nr = get_param_num_from_sym(sym);
  64         if (arg_nr < 0)
  65                 goto free;
  66         if (param_was_set_var_sym(name, sym))
  67                 goto free;
  68         set_state_stree(&used_stree, my_id, name, sym, &used);
  69 free:
  70         free_string(name);
  71 }
  72
  73 static void process_states(void)
  74 {
  75         struct sm_state *tmp;
  76         int arg;
  77         const char *name;
  78
  79         FOR_EACH_SM(used_stree, tmp) {
  80                 arg = get_param_num_from_sym(tmp->sym);
  81                 if (arg < 0)
  82                         continue;
  83                 name = get_param_name(tmp);
  84                 if (!name)
  85                         continue;
  86                 if (strcmp(name, "$") == 0 ||
  87                     strcmp(name, "*$") == 0)
  88                         continue;
  89                 if (is_recursive_member(name))
  90                         continue;
  91
  92                 if (is_ignored_kernel_data(name))
  93                         continue;
  94
  95                 sql_insert_return_implies(PARAM_USED, arg, name, "");
  96         } END_FOR_EACH_SM(tmp);
  97
  98         free_stree(&used_stree);
  99 }
 100
 101 static void match_function_def(struct symbol *sym)
 102 {
 103         free_stree(&used_stree);
 104 }
 105
 106 void register_param_used(int id)
 107 {
 108         my_id = id;
 109
 110         add_hook(&match_function_def, AFTER_FUNC_HOOK);
 111         add_function_data((unsigned long *)&used_stree);
 112
 113         add_get_state_hook(&get_state_hook);
 114
 115         select_return_implies_hook(PARAM_USED, &set_param_used);
 116         all_return_states_hook(&process_states);
 117 }