check_wrong_size_arg.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 #include "smatch.h"
  19
  20 static int my_id;
  21
  22 static void match_parameter(const char *fn, struct expression *expr, void *_param)
  23 {
  24         int param = PTR_INT(_param);
  25         struct expression *arg;
  26         char *name;
  27
  28         arg = get_argument_from_call_expr(expr->args, param);
  29         arg = strip_expr(arg);
  30         if (!arg)
  31                 return;
  32         if (arg->type != EXPR_COMPARE)
  33                 return;
  34
  35         name = expr_to_str_sym(arg, NULL);
  36         sm_msg("warn: expected a buffer size but got a comparison '%s'", name);
  37         free_string(name);
  38 }
  39
  40 static void register_funcs_from_file(void)
  41 {
  42         char name[256];
  43         struct token *token;
  44         const char *func;
  45         char prev_func[256];
  46         int size;
  47
  48         memset(prev_func, 0, sizeof(prev_func));
  49         snprintf(name, 256, "%s.sizeof_param", option_project_str);
  50         name[255] = '\0';
  51         token = get_tokens_file(name);
  52         if (!token)
  53                 return;
  54         if (token_type(token) != TOKEN_STREAMBEGIN)
  55                 return;
  56         token = token->next;
  57         while (token_type(token) != TOKEN_STREAMEND) {
  58                 if (token_type(token) != TOKEN_IDENT)
  59                         return;
  60                 func = show_ident(token->ident);
  61
  62                 token = token->next;
  63                 if (token_type(token) != TOKEN_NUMBER)
  64                         return;
  65                 size = atoi(token->number);
  66
  67                 token = token->next;
  68                 if (token_type(token) != TOKEN_NUMBER)
  69                         return;
  70                 /* we don't care which argument hold the buf pointer */
  71                 token = token->next;
  72
  73                 if (strcmp(func, prev_func) == 0)
  74                         continue;
  75                 strncpy(prev_func, func, 255);
  76
  77                 add_function_hook(func, &match_parameter, INT_PTR(size));
  78
  79         }
  80         clear_token_alloc();
  81 }
  82
  83 void check_wrong_size_arg(int id)
  84 {
  85         my_id = id;
  86         register_funcs_from_file();
  87 }