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 /* originally:
  24  *  "(?:CreateFile|CreateMailslot|CreateNamedPipe|FindFirstFile(?:Ex)?|OpenConsole|SetupOpenInfFile|socket)[AW]?"
  25  *
  26  */
  27 static const char *filehandle_funcs[] = {
  28         "CreateFile",
  29         "CreateMailslot",
  30         "CreateNamedPipe",
  31         "FindFirstFile",
  32         "FindFirstFileEx",
  33         "OpenConsole",
  34         "SetupOpenInfFile",
  35         "socket",
  36         NULL,
  37 };
  38
  39 static void ok_to_use(struct sm_state *sm)
  40 {
  41         if (sm->state != &oktocheck)
  42                 set_state(my_id, sm->name, sm->sym, &oktocheck);
  43 }
  44
  45 static void match_returns_handle(const char *fn, struct expression *expr,
  46                              void *info)
  47 {
  48         char *left_name = NULL;
  49         struct symbol *left_sym;
  50
  51         left_name = get_variable_from_expr(expr->left, &left_sym);
  52         if (!left_name || !left_sym)
  53                 goto free;
  54         set_state_expr(my_id, expr->left, &filehandle);
  55 free:
  56         free_string(left_name);
  57 }
  58
  59 static void match_condition(struct expression *expr)
  60 {
  61         if (expr->type == EXPR_ASSIGNMENT)
  62                 match_condition(expr->left);
  63
  64         if (get_state_expr(my_id, expr) == &filehandle) {
  65                 char *name;
  66
  67                 name = get_variable_from_expr(expr, NULL);
  68                 sm_msg("error: comparing a filehandle against zero '%s'", name);
  69                 set_state_expr(my_id, expr, &oktocheck);
  70                 free_string(name);
  71         }
  72 }
  73
  74 void check_wine_filehandles(int id)
  75 {
  76         int i;
  77
  78         if (option_project != PROJ_WINE)
  79                 return;
  80
  81         my_id = id;
  82         for (i = 0; filehandle_funcs[i]; i++) {
  83                 add_function_assign_hook(filehandle_funcs[i],
  84                                          &match_returns_handle, NULL);
  85         }
  86         add_hook(&match_condition, CONDITION_HOOK);
  87         add_modification_hook(my_id, ok_to_use);
  88 }