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             __in_fake_struct_assign)
  42                 return;
  43
  44         if (!name || name[0] == '&')
  45                 return;
  46
  47         if (name == prev)
  48                 return;
  49         prev = name;
  50
  51         arg = get_param_num_from_sym(sym);
  52         if (arg < 0)
  53                 return;
  54         if (param_was_set_var_sym(name, sym))
  55                 return;
  56         if (parent_was_PARAM_CLEAR(name, sym))
  57                 return;
  58
  59         set_state_stree(&used_stree, my_id, name, sym, &used);
  60 }
  61
  62 static void set_param_used(struct expression *call, struct expression *arg, char *key, char *unused)
  63 {
  64         struct symbol *sym;
  65         char *name;
  66         int arg_nr;
  67
  68         if (!option_info)
  69                 return;
  70
  71         if (key[0] == '&')
  72                 return;
  73
  74         name = get_variable_from_key(arg, key, &sym);
  75         if (!name || !sym)
  76                 goto free;
  77
  78         arg_nr = get_param_num_from_sym(sym);
  79         if (arg_nr < 0)
  80                 goto free;
  81         if (param_was_set_var_sym(name, sym))
  82                 goto free;
  83         set_state_stree(&used_stree, my_id, name, sym, &used);
  84 free:
  85         free_string(name);
  86 }
  87
  88 static void process_states(void)
  89 {
  90         struct sm_state *tmp;
  91         int arg;
  92         const char *name;
  93
  94         FOR_EACH_SM(used_stree, tmp) {
  95                 arg = get_param_num_from_sym(tmp->sym);
  96                 if (arg < 0)
  97                         continue;
  98                 name = get_param_name(tmp);
  99                 if (!name)
 100                         continue;
 101                 if (strcmp(name, "$") == 0 ||
 102                     strcmp(name, "*$") == 0)
 103                         continue;
 104                 if (is_recursive_member(name))
 105                         continue;
 106
 107                 if (is_ignored_kernel_data(name))
 108                         continue;
 109
 110                 sql_insert_return_implies(PARAM_USED, arg, name, "");
 111         } END_FOR_EACH_SM(tmp);
 112
 113         free_stree(&used_stree);
 114 }
 115
 116 static void match_function_def(struct symbol *sym)
 117 {
 118         free_stree(&used_stree);
 119 }
 120
 121 void register_param_used(int id)
 122 {
 123         my_id = id;
 124
 125         add_hook(&match_function_def, AFTER_FUNC_HOOK);
 126         add_function_data((unsigned long *)&used_stree);
 127
 128         add_get_state_hook(&get_state_hook);
 129
 130         select_return_implies_hook(PARAM_USED, &set_param_used);
 131         all_return_states_hook(&process_states);
 132 }