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         static const char *prev;
  31         int arg;
  32
  33         if (!option_info)
  34                 return;
  35
  36         if (__ignore_param_used ||
  37             __in_fake_assign ||
  38             __in_fake_parameter_assign ||
  39             __in_function_def ||
  40             __in_unmatched_hook)
  41                 return;
  42
  43         if (!name || name[0] == '&')
  44                 return;
  45
  46         if (name == prev)
  47                 return;
  48         prev = name;
  49
  50         arg = get_param_num_from_sym(sym);
  51         if (arg < 0)
  52                 return;
  53         if (param_was_set_var_sym(name, sym))
  54                 return;
  55         set_state_stree(&used_stree, my_id, name, sym, &used);
  56 }
  57
  58 static void set_param_used(struct expression *call, struct expression *arg, char *key, char *unused)
  59 {
  60         struct symbol *sym;
  61         char *name;
  62         int arg_nr;
  63
  64         if (!option_info)
  65                 return;
  66
  67         if (key[0] == '&')
  68                 return;
  69
  70         name = get_variable_from_key(arg, key, &sym);
  71         if (!name || !sym)
  72                 goto free;
  73
  74         arg_nr = get_param_num_from_sym(sym);
  75         if (arg_nr < 0)
  76                 goto free;
  77         if (param_was_set_var_sym(name, sym))
  78                 goto free;
  79         set_state_stree(&used_stree, my_id, name, sym, &used);
  80 free:
  81         free_string(name);
  82 }
  83
  84 static void process_states(void)
  85 {
  86         struct sm_state *tmp;
  87         int arg;
  88         const char *name;
  89
  90         FOR_EACH_SM(used_stree, tmp) {
  91                 arg = get_param_num_from_sym(tmp->sym);
  92                 if (arg < 0)
  93                         continue;
  94                 name = get_param_name(tmp);
  95                 if (!name)
  96                         continue;
  97                 if (strcmp(name, "$") == 0 ||
  98                     strcmp(name, "*$") == 0)
  99                         continue;
 100                 if (is_recursive_member(name))
 101                         continue;
 102
 103                 if (is_ignored_kernel_data(name))
 104                         continue;
 105
 106                 sql_insert_return_implies(PARAM_USED, arg, name, "");
 107         } END_FOR_EACH_SM(tmp);
 108
 109         free_stree(&used_stree);
 110 }
 111
 112 static void match_function_def(struct symbol *sym)
 113 {
 114         free_stree(&used_stree);
 115 }
 116
 117 void register_param_used(int id)
 118 {
 119         my_id = id;
 120
 121         add_hook(&match_function_def, AFTER_FUNC_HOOK);
 122         add_function_data((unsigned long *)&used_stree);
 123
 124         add_get_state_hook(&get_state_hook);
 125
 126         select_return_implies_hook(PARAM_USED, &set_param_used);
 127         all_return_states_hook(&process_states);
 128 }