libsanitizer/asan/asan_win_dynamic_runtime_thunk.cc

   1 //===-- asan_win_uar_thunk.cc ---------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // This file defines things that need to be present in the application modules
  11 // to interact with the ASan DLL runtime correctly and can't be implemented
  12 // using the default "import library" generated when linking the DLL RTL.
  13 //
  14 // This includes:
  15 //  - forwarding the detect_stack_use_after_return runtime option
  16 //  - installing a custom SEH handler
  17 //
  18 //===----------------------------------------------------------------------===//
  19
  20 // Only compile this code when buidling asan_dynamic_runtime_thunk.lib
  21 // Using #ifdef rather than relying on Makefiles etc.
  22 // simplifies the build procedure.
  23 #ifdef ASAN_DYNAMIC_RUNTIME_THUNK
  24 extern "C" {
  25 __declspec(dllimport) int __asan_set_seh_filter();
  26 __declspec(dllimport) int __asan_should_detect_stack_use_after_return();
  27
  28 // Define a copy of __asan_option_detect_stack_use_after_return that should be
  29 // used when linking an MD runtime with a set of object files on Windows.
  30 //
  31 // The ASan MD runtime dllexports '__asan_option_detect_stack_use_after_return',
  32 // so normally we would just dllimport it.  Unfortunately, the dllimport
  33 // attribute adds __imp_ prefix to the symbol name of a variable.
  34 // Since in general we don't know if a given TU is going to be used
  35 // with a MT or MD runtime and we don't want to use ugly __imp_ names on Windows
  36 // just to work around this issue, let's clone the a variable that is
  37 // constant after initialization anyways.
  38 int __asan_option_detect_stack_use_after_return =
  39     __asan_should_detect_stack_use_after_return();
  40
  41 // Set the ASan-specific SEH handler at the end of CRT initialization of each
  42 // module (see asan_win.cc for the details).
  43 //
  44 // Unfortunately, putting a pointer to __asan_set_seh_filter into
  45 // __asan_intercept_seh gets optimized out, so we have to use an extra function.
  46 static int SetSEHFilter() { return __asan_set_seh_filter(); }
  47 #pragma section(".CRT$XIZ", long, read)  // NOLINT
  48 __declspec(allocate(".CRT$XIZ")) int (*__asan_seh_interceptor)() = SetSEHFilter;
  49 }
  50 #endif // ASAN_DYNAMIC_RUNTIME_THUNK