Imported Upstream version 3.2.0

[debian/amanda] / gnulib / alignof.h

diff --git a/gnulib/alignof.h b/gnulib/alignof.h
new file mode 100644 (file)
index 0000000..240468c
--- /dev/null
+++ b/gnulib/alignof.h
@@ -0,0 +1,53 @@
+/* Determine alignment of types.
+   Copyright (C) 2003-2004, 2006, 2009-2010 Free Software Foundation, Inc.
+
+   This program 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 program 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.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _ALIGNOF_H
+#define _ALIGNOF_H
+
+#include <stddef.h>
+
+/* Determine the alignment of a structure slot (field) of a given type,
+   at compile time.  Note that the result depends on the ABI.
+   Note: The result cannot be used as a value for an 'enum' constant,
+   due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc.  */
+#if defined __cplusplus
+  template <class type> struct alignof_helper { char __slot1; type __slot2; };
+# define alignof_slot(type) offsetof (alignof_helper<type>, __slot2)
+#else
+# define alignof_slot(type) offsetof (struct { char __slot1; type __slot2; }, __slot2)
+#endif
+
+/* Determine the good alignment of a object of the given type at compile time.
+   Note that this is not necessarily the same as alignof_slot(type).
+   For example, with GNU C on x86 platforms: alignof_type(double) = 8, but
+   - when -malign-double is not specified:  alignof_slot(double) = 4,
+   - when -malign-double is specified:      alignof_slot(double) = 8.
+   Note: The result cannot be used as a value for an 'enum' constant,
+   due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc.  */
+#if defined __GNUC__
+# define alignof_type __alignof__
+#else
+# define alignof_type alignof_slot
+#endif
+
+/* alignof is an alias for alignof_slot semantics, since that's what most
+   callers need.
+   Note: The result cannot be used as a value for an 'enum' constant,
+   due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc.  */
+#define alignof alignof_slot
+
+#endif /* _ALIGNOF_H */