widget/windows/WindowsEventLog.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_WindowsEventLog_h
   8 #define mozilla_WindowsEventLog_h
   9
  10 /**
  11  * Report messages to the Windows Event Log.
  12  */
  13
  14 #include <stdio.h>
  15 #include <windows.h>
  16
  17 #include "mozilla/Attributes.h"
  18 #include "mozilla/UniquePtr.h"
  19
  20 /**
  21  * This header is intended for self-contained, header-only, utility code for
  22  * Win32. It may be used outside of xul.dll, in places such as
  23  * default-browser-agent.exe or notificationrouter.dll. If your code creates
  24  * dependencies on Mozilla libraries, you should put it elsewhere.
  25  */
  26
  27 #define MOZ_WIN_EVENT_LOG_ERROR(source, hr) \
  28   mozilla::WriteWindowsEventLogHresult(source, hr, __FUNCTION__, __LINE__)
  29 #define MOZ_WIN_EVENT_LOG_ERROR_MESSAGE(source, format, ...)              \
  30   mozilla::WriteWindowsEventLogErrorMessage(source, format, __FUNCTION__, \
  31                                             __LINE__, ##__VA_ARGS__)
  32
  33 namespace mozilla {
  34
  35 static void WriteWindowsEventLogErrorBuffer(const wchar_t* eventSourceName,
  36                                             const wchar_t* buffer,
  37                                             DWORD eventId) {
  38   HANDLE source = RegisterEventSourceW(nullptr, eventSourceName);
  39   if (!source) {
  40     // Not much we can do about this.
  41     return;
  42   }
  43
  44   const wchar_t* stringsArray[] = {buffer};
  45   ReportEventW(source, EVENTLOG_ERROR_TYPE, 0, eventId, nullptr, 1, 0,
  46                stringsArray, nullptr);
  47
  48   DeregisterEventSource(source);
  49 }
  50
  51 void WriteWindowsEventLogHresult(const wchar_t* eventSourceName, HRESULT hr,
  52                                  const char* sourceFile, int sourceLine) {
  53   const wchar_t* format = L"0x%X in %S:%d";
  54   int bufferSize = _scwprintf(format, hr, sourceFile, sourceLine);
  55   ++bufferSize;  // Extra character for terminating null
  56   mozilla::UniquePtr<wchar_t[]> errorStr =
  57       mozilla::MakeUnique<wchar_t[]>(bufferSize);
  58
  59   _snwprintf_s(errorStr.get(), bufferSize, _TRUNCATE, format, hr, sourceFile,
  60                sourceLine);
  61
  62   WriteWindowsEventLogErrorBuffer(eventSourceName, errorStr.get(), hr);
  63 }
  64
  65 MOZ_FORMAT_WPRINTF(1, 4)
  66 void WriteWindowsEventLogErrorMessage(const wchar_t* eventSourceName,
  67                                       const wchar_t* messageFormat,
  68                                       const char* sourceFile, int sourceLine,
  69                                       ...) {
  70   // First assemble the passed message
  71   va_list ap;
  72   va_start(ap, sourceLine);
  73   int bufferSize = _vscwprintf(messageFormat, ap);
  74   ++bufferSize;  // Extra character for terminating null
  75   va_end(ap);
  76   mozilla::UniquePtr<wchar_t[]> message =
  77       mozilla::MakeUnique<wchar_t[]>(bufferSize);
  78
  79   va_start(ap, sourceLine);
  80   vswprintf(message.get(), bufferSize, messageFormat, ap);
  81   va_end(ap);
  82
  83   // Next, assemble the complete error message to print
  84   const wchar_t* errorFormat = L"Error: %s (%S:%d)";
  85   bufferSize = _scwprintf(errorFormat, message.get(), sourceFile, sourceLine);
  86   ++bufferSize;  // Extra character for terminating null
  87   mozilla::UniquePtr<wchar_t[]> errorStr =
  88       mozilla::MakeUnique<wchar_t[]>(bufferSize);
  89
  90   _snwprintf_s(errorStr.get(), bufferSize, _TRUNCATE, errorFormat,
  91                message.get(), sourceFile, sourceLine);
  92
  93   WriteWindowsEventLogErrorBuffer(eventSourceName, errorStr.get(), 0);
  94 }
  95
  96 }  // namespace mozilla
  97
  98 #endif  // mozilla_WindowsEventLog_h