check_assigned_expr.c

   1 /*
   2  * Copyright (C) 2009 Dan Carpenter.
   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 not a check.  It just saves an struct expression pointer
  20  * whenever something is assigned.  This can be used later on by other scripts.
  21  */
  22
  23 #include "smatch.h"
  24 #include "smatch_slist.h"
  25 #include "smatch_extra.h"
  26
  27 int check_assigned_expr_id;
  28 static int my_id;
  29
  30 struct expression *get_assigned_expr(struct expression *expr)
  31 {
  32         struct smatch_state *state;
  33
  34         state = get_state_expr(my_id, expr);
  35         if (!state)
  36                 return NULL;
  37         return (struct expression *)state->data;
  38 }
  39
  40 static struct smatch_state *alloc_my_state(struct expression *expr)
  41 {
  42         struct smatch_state *state;
  43         char *name;
  44
  45         state = __alloc_smatch_state(0);
  46         expr = strip_expr(expr);
  47         name = expr_to_str(expr);
  48         state->name = alloc_sname(name);
  49         free_string(name);
  50         state->data = expr;
  51         return state;
  52 }
  53
  54 static void match_assignment(struct expression *expr)
  55 {
  56         if (expr->op != '=')
  57                 return;
  58         if (is_fake_call(expr->right))
  59                 return;
  60         set_state_expr(my_id, expr->left, alloc_my_state(expr->right));
  61 }
  62
  63 void check_assigned_expr(int id)
  64 {
  65         my_id = check_assigned_expr_id = id;
  66         add_hook(&match_assignment, ASSIGNMENT_HOOK);
  67 }