Mercurial > hg > octave-lojdl > gnulib-hg
changeset 11553:7388d8b01b56
New module 'alignof'.
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Fri, 08 May 2009 13:19:41 +0200 |
| parents | a12fc7e93275 |
| children | 2d40c73ca3d5 |
| files | ChangeLog lib/alignof.h modules/alignof |
| diffstat | 3 files changed, 67 insertions(+), 0 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2009-05-08 Bruno Haible <bruno@clisp.org> + + New module 'alignof'. + * lib/alignof.h: New file. + * modules/alignof: New file. + 2009-05-04 David Bartley <dtbartle@csclub.uwaterloo.ca> Bruno Haible <bruno@clisp.org>
new file mode 100644 --- /dev/null +++ b/lib/alignof.h @@ -0,0 +1,41 @@ +/* Determine alignment of types. + Copyright (C) 2003-2004, 2006, 2009 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 2, 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 type at compile time. */ +#if defined __GNUC__ +# define alignof __alignof__ +#elif defined __cplusplus + template <class type> struct alignof_helper { char __slot1; type __slot2; }; +# define alignof(type) offsetof (alignof_helper<type>, __slot2) +#elif defined __hpux + /* Work around a HP-UX 10.20 cc bug with enums constants defined as offsetof + values. */ +# define alignof(type) (sizeof (type) <= 4 ? 4 : 8) +#elif defined _AIX + /* Work around an AIX 3.2.5 xlc bug with enums constants defined as offsetof + values. */ +# define alignof(type) (sizeof (type) <= 4 ? 4 : 8) +#else +# define alignof(type) offsetof (struct { char __slot1; type __slot2; }, __slot2) +#endif + +#endif /* _ALIGNOF_H */