check_wine_filehandles.c

   1 /*
   2  * sparse/check_wine_filehandles.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * In wine you aren't allowed to compare file handles with 0,
  12  * only with INVALID_HANDLE_VALUE.
  13  *
  14  */
  15
  16 #include "smatch.h"
  17
  18 static int my_id;
  19
  20 STATE(filehandle);
  21 STATE(oktocheck);
  22
  23
  24 /* originally:
  25  *  "(?:CreateFile|CreateMailslot|CreateNamedPipe|FindFirstFile(?:Ex)?|OpenConsole|SetupOpenInfFile|socket)[AW]?"
  26  *
  27  */
  28 static const char *filehandle_funcs[] = {
  29         "CreateFile",
  30         "CreateMailslot",
  31         "CreateNamedPipe",
  32         "FindFirstFile",
  33         "FindFirstFileEx",
  34         "OpenConsole",
  35         "SetupOpenInfFile",
  36         "socket",
  37         NULL,
  38 };
  39
  40 static void match_returns_handle(const char *fn, struct expression *expr,
  41                              void *info)
  42 {
  43         char *left_name = NULL;
  44         struct symbol *left_sym;
  45
  46         left_name = get_variable_from_expr(expr->left, &left_sym);
  47         if (!left_name || !left_sym)
  48                 goto free;
  49         set_state_expr(my_id, expr->left, &filehandle);
  50 free:
  51         free_string(left_name);
  52 }
  53
  54 static void match_condition(struct expression *expr)
  55 {
  56         if (expr->type == EXPR_ASSIGNMENT)
  57                 match_condition(expr->left);
  58
  59         if (get_state_expr(my_id, expr) == &filehandle) {
  60                 char *name;
  61
  62                 name = get_variable_from_expr(expr, NULL);
  63                 sm_msg("error: comparing a filehandle against zero '%s'", name);
  64                 set_state_expr(my_id, expr, &oktocheck);
  65                 free_string(name);
  66         }
  67 }
  68
  69 void check_wine_filehandles(int id)
  70 {
  71         int i;
  72
  73         if (option_project != PROJ_WINE)
  74                 return;
  75
  76         my_id = id;
  77         set_default_state(my_id, &oktocheck);
  78         for(i = 0; filehandle_funcs[i]; i++) {
  79                 add_function_assign_hook(filehandle_funcs[i],
  80                                          &match_returns_handle, NULL);
  81         }
  82         add_hook(&match_condition, CONDITION_HOOK);
  83 }