check_le16.c

   1 /*
   2  * smatch/check_le16.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "smatch.h"
  11
  12 static int my_id;
  13
  14 static int is_le16(struct symbol *type)
  15 {
  16         if (type->ctype.alignment != 2)
  17                 return 0;
  18         if (!(type->ctype.modifiers & MOD_UNSIGNED))
  19                 return 0;
  20         return 1;
  21 }
  22
  23 static void match_no_le16_param(const char *fn, struct expression *expr, void *param)
  24 {
  25         struct expression *arg;
  26         struct symbol *type;
  27         char *name;
  28
  29         arg = get_argument_from_call_expr(expr->args, (int)param);
  30         arg = strip_parens(arg);
  31         if (!arg)
  32                 return;
  33         if (arg->type != EXPR_FORCE_CAST)
  34                 return;
  35
  36         type = get_type(arg);
  37         if (!is_le16(type))
  38                 return;
  39
  40         arg = strip_expr(arg);
  41         name = get_variable_from_expr_complex(arg, NULL);
  42         sm_msg("warn: don't need to call cpu_to_le16() for '%s'", name);
  43         free_string(name);
  44 }
  45
  46 static void register_funcs_from_file(void)
  47 {
  48         struct token *token;
  49         const char *func;
  50         int arg;
  51
  52         token = get_tokens_file("kernel.no_le16");
  53         if (!token)
  54                 return;
  55         if (token_type(token) != TOKEN_STREAMBEGIN)
  56                 return;
  57         token = token->next;
  58         while (token_type(token) != TOKEN_STREAMEND) {
  59                 if (token_type(token) != TOKEN_IDENT)
  60                         return;
  61                 func = show_ident(token->ident);
  62                 token = token->next;
  63                 if (token_type(token) != TOKEN_NUMBER)
  64                         return;
  65                 arg = atoi(token->number);
  66                 add_function_hook(func, &match_no_le16_param, INT_PTR(arg));
  67                 token = token->next;
  68         }
  69         clear_token_alloc();
  70 }
  71
  72 void check_le16(int id)
  73 {
  74         if (option_project != PROJ_KERNEL)
  75                 return;
  76         if (!option_spammy)
  77                 return;
  78         my_id = id;
  79         register_funcs_from_file();
  80 }