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