base/win/wrapped_window_proc_unittest.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/message_loop/message_loop.h"
   6 #include "base/win/wrapped_window_proc.h"
   7 #include "testing/gtest/include/gtest/gtest.h"
   8
   9 namespace {
  10
  11 DWORD kExceptionCode = 12345;
  12 WPARAM kCrashMsg = 98765;
  13
  14 // A trivial WindowProc that generates an exception.
  15 LRESULT CALLBACK TestWindowProc(HWND hwnd, UINT message,
  16                                 WPARAM wparam, LPARAM lparam) {
  17   if (message == kCrashMsg)
  18     RaiseException(kExceptionCode, 0, 0, NULL);
  19   return DefWindowProc(hwnd, message, wparam, lparam);
  20 }
  21
  22 // This class implements an exception filter that can be queried about a past
  23 // exception.
  24 class TestWrappedExceptionFiter {
  25  public:
  26   TestWrappedExceptionFiter() : called_(false) {
  27     EXPECT_FALSE(s_filter_);
  28     s_filter_ = this;
  29   }
  30
  31   ~TestWrappedExceptionFiter() {
  32     EXPECT_EQ(s_filter_, this);
  33     s_filter_ = NULL;
  34   }
  35
  36   bool called() {
  37     return called_;
  38   }
  39
  40   // The actual exception filter just records the exception.
  41   static int Filter(EXCEPTION_POINTERS* info) {
  42     EXPECT_FALSE(s_filter_->called_);
  43     if (info->ExceptionRecord->ExceptionCode == kExceptionCode)
  44       s_filter_->called_ = true;
  45     return EXCEPTION_EXECUTE_HANDLER;
  46   }
  47
  48  private:
  49   bool called_;
  50   static TestWrappedExceptionFiter* s_filter_;
  51 };
  52 TestWrappedExceptionFiter* TestWrappedExceptionFiter::s_filter_ = NULL;
  53
  54 }  // namespace.
  55
  56 TEST(WrappedWindowProc, CatchesExceptions) {
  57   HINSTANCE hinst = GetModuleHandle(NULL);
  58   std::wstring class_name(L"TestClass");
  59
  60   WNDCLASS wc = {0};
  61   wc.lpfnWndProc = base::win::WrappedWindowProc<TestWindowProc>;
  62   wc.hInstance = hinst;
  63   wc.lpszClassName = class_name.c_str();
  64   RegisterClass(&wc);
  65
  66   HWND window = CreateWindow(class_name.c_str(), 0, 0, 0, 0, 0, 0, HWND_MESSAGE,
  67                              0, hinst, 0);
  68   ASSERT_TRUE(window);
  69
  70   // Before generating the exception we make sure that the filter will see it.
  71   TestWrappedExceptionFiter wrapper;
  72   base::win::WinProcExceptionFilter old_filter =
  73       base::win::SetWinProcExceptionFilter(TestWrappedExceptionFiter::Filter);
  74
  75   SendMessage(window, kCrashMsg, 0, 0);
  76   EXPECT_TRUE(wrapper.called());
  77
  78   base::win::SetWinProcExceptionFilter(old_filter);
  79 }