1 files changed, 74 insertions, 0 deletions
diff --git a/bits/sysmacros.h b/bits/sysmacros.h
new file mode 100644
index 0000000000..e2c0bc2f65
--- /dev/null
+++ b/bits/sysmacros.h
@@ -0,0 +1,74 @@
+/* Definitions of macros to access `dev_t' values.
+   Copyright (C) 1996-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_SYSMACROS_H
+#define _BITS_SYSMACROS_H 1
+
+#ifndef _SYS_SYSMACROS_H
+# error "Never include <bits/sysmacros.h> directly; use <sys/sysmacros.h> instead."
+#endif
+
+/* dev_t in glibc is a 64-bit quantity, with 32-bit major and minor numbers.
+   Our default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of
+   the major number and m is a hex digit of the minor number.  This is
+   downward compatible with legacy systems where dev_t is 16 bits wide,
+   encoded as MMmm.  It is also downward compatible with the Linux kernel,
+   which (as of 2016) uses 32-bit dev_t, encoded as mmmM MMmm.
+
+   Systems that use an incompatible encoding for dev_t should override this
+   file in the appropriate sysdeps subdirectory.  */
+
+#define __SYSMACROS_DECLARE_MAJOR(DECL_TEMPL)			\
+  DECL_TEMPL(unsigned int, major, (__dev_t __dev))
+
+#define __SYSMACROS_DEFINE_MAJOR(DECL_TEMPL)			\
+  __SYSMACROS_DECLARE_MAJOR (DECL_TEMPL)			\
+  {								\
+    unsigned int __major;					\
+    __major  = ((__dev & (__dev_t) 0x00000000000fff00u) >>  8); \
+    __major |= ((__dev & (__dev_t) 0xfffff00000000000u) >> 32); \
+    return __major;						\
+  }
+
+#define __SYSMACROS_DECLARE_MINOR(DECL_TEMPL)			\
+  DECL_TEMPL(unsigned int, minor, (__dev_t __dev))
+
+#define __SYSMACROS_DEFINE_MINOR(DECL_TEMPL)			\
+  __SYSMACROS_DECLARE_MINOR (DECL_TEMPL)			\
+  {								\
+    unsigned int __minor;					\
+    __minor  = ((__dev & (__dev_t) 0x00000000000000ffu) >>  0); \
+    __minor |= ((__dev & (__dev_t) 0x00000ffffff00000u) >> 12); \
+    return __minor;						\
+  }
+
+#define __SYSMACROS_DECLARE_MAKEDEV(DECL_TEMPL)			\
+  DECL_TEMPL(__dev_t, makedev, (unsigned int __major, unsigned int __minor))
+
+#define __SYSMACROS_DEFINE_MAKEDEV(DECL_TEMPL)			\
+  __SYSMACROS_DECLARE_MAKEDEV (DECL_TEMPL)			\
+  {								\
+    __dev_t __dev;						\
+    __dev  = (((__dev_t) (__major & 0x00000fffu)) <<  8);	\
+    __dev |= (((__dev_t) (__major & 0xfffff000u)) << 32);	\
+    __dev |= (((__dev_t) (__minor & 0x000000ffu)) <<  0);	\
+    __dev |= (((__dev_t) (__minor & 0xffffff00u)) << 12);	\
+    return __dev;						\
+  }
+
+#endif /* bits/sysmacros.h */