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