check_test_bit.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 void match_test_bit(const char *fn, struct expression *expr, void *data)
  24 {
  25         struct expression *arg;
  26         char *macro;
  27
  28         arg = get_argument_from_call_expr(expr->args, 0);
  29         arg = strip_expr(arg);
  30
  31         if (!arg || arg->type != EXPR_BINOP)
  32                 return;
  33         if (arg->op != '|' && arg->op != SPECIAL_LEFTSHIFT)
  34                 return;
  35         macro = get_macro_name(arg->pos);
  36         if (macro && strstr(macro, "cpu_has"))
  37                 return;
  38         sm_msg("warn: test_bit() takes a bit number");
  39 }
  40
  41 void check_test_bit(int id)
  42 {
  43         my_id = id;
  44
  45         if (option_project != PROJ_KERNEL)
  46                 return;
  47
  48         add_function_hook("test_bit", &match_test_bit, NULL);
  49         add_function_hook("variable_test_bit", &match_test_bit, NULL);
  50         add_function_hook("set_bit", &match_test_bit, NULL);
  51         add_function_hook("clear_bit", &match_test_bit, NULL);
  52 }