1 /*
   2  * Copyright (C) 2017 Oracle.  All rights reserved.
   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 basically stores when a pointer is stored as a struct member.
  20  *
  21  */
  22 
  23 #include "smatch.h"
  24 #include "smatch_slist.h"
  25 #include "smatch_extra.h"
  26 
  27 static int my_id;
  28 
  29 static void match_assign(struct expression *expr)
  30 {
  31         struct expression *left, *right;
  32         mtag_t left_tag, right_tag;
  33         int offset;
  34 
  35         if (expr->op != '=')
  36                 return;
  37 
  38         left = strip_expr(expr->left);
  39         right = strip_expr(expr->right);
  40 
  41         if (left->type != EXPR_DEREF)
  42                 return;
  43 
  44         offset = get_member_offset_from_deref(left);
  45         if (offset < 0)
  46                 return;
  47 
  48         if (!get_mtag(left->deref, &left_tag))
  49                 return;
  50         if (!get_mtag(right, &right_tag))
  51                 return;
  52 
  53         sql_insert_mtag_map(right_tag, -offset, left_tag);
  54 }
  55 
  56 void register_mtag_map(int id)
  57 {
  58         my_id = id;
  59 
  60         add_hook(&match_assign, ASSIGNMENT_HOOK);
  61         add_hook(&match_assign, GLOBAL_ASSIGNMENT_HOOK);
  62 }