--- /dev/null
+// Specific definitions for IRIX -*- C++ -*-
+
+// Copyright (C) 2001, 2002, 2005, 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef _GLIBCXX_OS_DEFINES
+#define _GLIBCXX_OS_DEFINES 1
+
+// System-specific #define, typedefs, corrections, etc, go here. This
+// file will come before all others.
+
+// We need large file support. There are two ways to turn it on: by
+// defining either _LARGEFILE64_SOURCE or _SGI_SOURCE. However, it
+// does not actually work to define only the former, as then
+// <sys/stat.h> is invalid: `st_blocks' is defined to be a macro, but
+// then used as a field name. So, we have to turn on _SGI_SOURCE.
+// That only works if _POSIX_SOURCE is turned off, so we have to
+// explicitly turn it off. (Some of the libio C files explicitly try
+// to turn it on.) _SGI_SOURCE is actually turned on implicitly via
+// the command-line.
+#undef _POSIX_SOURCE
+
+// GCC does not use thunks on IRIX.
+#define _G_USING_THUNKS 0
+
+#endif
+