1 files changed, 69 insertions, 0 deletions
diff --git a/mozglue/misc/Debug.h b/mozglue/misc/Debug.h
new file mode 100644
index 0000000000..f8f05c6299
--- /dev/null
+++ b/mozglue/misc/Debug.h
@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_glue_Debug_h
+#define mozilla_glue_Debug_h
+
+/* This header file intends to supply debugging utilities for use in code
+ * that cannot use XPCOM debugging facilities like nsDebug.h.
+ * e.g. mozglue, browser/app
+ *
+ * NB: printf_stderr() is in the global namespace, so include this file with
+ * care; avoid including from header files.
+ */
+
+#include <io.h>
+#if defined(XP_WIN)
+#  include <windows.h>
+#endif  // defined(XP_WIN)
+#include "mozilla/Attributes.h"
+#include "mozilla/Sprintf.h"
+
+#if defined(MOZILLA_INTERNAL_API)
+#  error Do not include this file from XUL sources.
+#endif
+
+// Though this is a separate implementation than nsDebug's, we want to make the
+// declarations compatible to avoid confusing the linker if both headers are
+// included.
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+void printf_stderr(const char* fmt, ...) MOZ_FORMAT_PRINTF(1, 2);
+inline void printf_stderr(const char* fmt, ...) {
+#if defined(XP_WIN)
+  if (IsDebuggerPresent()) {
+    char buf[2048];
+    va_list args;
+    va_start(args, fmt);
+    VsprintfLiteral(buf, fmt, args);
+    va_end(args);
+    OutputDebugStringA(buf);
+  }
+#endif  // defined(XP_WIN)
+
+  // stderr is unbuffered by default so we open a new FILE (which is buffered)
+  // so that calls to printf_stderr are not as likely to get mixed together.
+  int fd = _fileno(stderr);
+  if (fd == -2) return;
+
+  FILE* fp = _fdopen(_dup(fd), "a");
+  if (!fp) return;
+
+  va_list args;
+  va_start(args, fmt);
+  vfprintf(fp, fmt, args);
+  va_end(args);
+
+  fclose(fp);
+}
+
+#ifdef __cplusplus
+}
+#endif  // __cplusplus
+
+#endif  // mozilla_glue_Debug_h