mozglue/misc/Debug.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   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 https://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_glue_Debug_h
   8 #define mozilla_glue_Debug_h
   9
  10 /* This header file intends to supply debugging utilities for use in code
  11  * that cannot use XPCOM debugging facilities like nsDebug.h.
  12  * e.g. mozglue, browser/app
  13  *
  14  * NB: printf_stderr() is in the global namespace, so include this file with
  15  * care; avoid including from header files.
  16  */
  17
  18 #include <io.h>
  19 #if defined(XP_WIN)
  20 #  include <windows.h>
  21 #endif  // defined(XP_WIN)
  22 #include "mozilla/Attributes.h"
  23 #include "mozilla/Sprintf.h"
  24
  25 #if defined(MOZILLA_INTERNAL_API)
  26 #  error Do not include this file from XUL sources.
  27 #endif
  28
  29 // Though this is a separate implementation than nsDebug's, we want to make the
  30 // declarations compatible to avoid confusing the linker if both headers are
  31 // included.
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif  // __cplusplus
  35
  36 void printf_stderr(const char* fmt, ...) MOZ_FORMAT_PRINTF(1, 2);
  37 inline void printf_stderr(const char* fmt, ...) {
  38 #if defined(XP_WIN)
  39   if (IsDebuggerPresent()) {
  40     char buf[2048];
  41     va_list args;
  42     va_start(args, fmt);
  43     VsprintfLiteral(buf, fmt, args);
  44     va_end(args);
  45     OutputDebugStringA(buf);
  46   }
  47 #endif  // defined(XP_WIN)
  48
  49   // stderr is unbuffered by default so we open a new FILE (which is buffered)
  50   // so that calls to printf_stderr are not as likely to get mixed together.
  51   int fd = _fileno(stderr);
  52   if (fd == -2) return;
  53
  54   FILE* fp = _fdopen(_dup(fd), "a");
  55   if (!fp) return;
  56
  57   va_list args;
  58   va_start(args, fmt);
  59   vfprintf(fp, fmt, args);
  60   va_end(args);
  61
  62   fclose(fp);
  63 }
  64
  65 #ifdef __cplusplus
  66 }
  67 #endif  // __cplusplus
  68
  69 #endif  // mozilla_glue_Debug_h