smatch_param_set.c

   1 /*
   2  * Copyright (C) 2012 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 /*
  19  * This is for functions like:
  20  *
  21  * int foo(int *x)
  22  * {
  23  *      if (*x == 42) {
  24  *              *x = 0;
  25  *              return 1;
  26  *      }
  27  *      return 0;
  28  * }
  29  *
  30  * If we return 1 that means the value of *x has been set to 0.  If we return
  31  * 0 then we have left *x alone.
  32  *
  33  */
  34
  35 #include "scope.h"
  36 #include "smatch.h"
  37 #include "smatch_slist.h"
  38 #include "smatch_extra.h"
  39
  40 static int my_id;
  41
  42 static struct smatch_state *unmatched_state(struct sm_state *sm)
  43 {
  44         return alloc_estate_empty();
  45 }
  46
  47 static void extra_mod_hook(const char *name, struct symbol *sym, struct smatch_state *state)
  48 {
  49         if (get_param_num_from_sym(sym) < 0)
  50                 return;
  51         set_state(my_id, name, sym, state);
  52 }
  53
  54 static void print_one_return_value_param(int return_id, char *return_ranges,
  55                         int param, struct sm_state *sm, char *implied_rl)
  56 {
  57         const char *param_name;
  58
  59         param_name = get_param_name(sm);
  60         if (!param_name)
  61                 return;
  62         if (strcmp(param_name, "$$") == 0)
  63                 return;
  64
  65         sql_insert_return_states(return_id, return_ranges, ADDED_VALUE, param,
  66                         param_name, implied_rl);
  67 }
  68
  69 static void print_return_value_param(int return_id, char *return_ranges, struct expression *expr)
  70 {
  71         struct stree *stree;
  72         struct sm_state *sm;
  73         struct smatch_state *extra;
  74         int param;
  75         struct range_list *rl;
  76
  77         stree = __get_cur_stree();
  78
  79         FOR_EACH_MY_SM(my_id, stree, sm) {
  80                 if (!estate_rl(sm->state))
  81                         continue;
  82                 extra = get_state(SMATCH_EXTRA, sm->name, sm->sym);
  83                 if (!estate_rl(extra))
  84                         continue;
  85                 rl = rl_intersection(estate_rl(sm->state), estate_rl(extra));
  86                 if (!rl)
  87                         continue;
  88
  89                 param = get_param_num_from_sym(sm->sym);
  90                 if (param < 0)
  91                         continue;
  92                 if (!sm->sym->ident)
  93                         continue;
  94                 print_one_return_value_param(return_id, return_ranges, param, sm, show_rl(rl));
  95         } END_FOR_EACH_SM(sm);
  96 }
  97
  98 void register_param_set(int id)
  99 {
 100         my_id = id;
 101
 102         add_extra_mod_hook(&extra_mod_hook);
 103         add_unmatched_state_hook(my_id, &unmatched_state);
 104         add_merge_hook(my_id, &merge_estates);
 105         add_split_return_callback(&print_return_value_param);
 106 }
 107