summaryrefslogtreecommitdiffstats
path: root/gl/alignof.h
diff options
context:
space:
mode:
authorThomas Guyot-Sionnest <dermoth@aei.ca>2010-04-08 01:11:46 (GMT)
committerThomas Guyot-Sionnest <dermoth@aei.ca>2010-04-13 01:26:35 (GMT)
commit74da141e618ef99959d509cb2e7be35a348a39db (patch)
tree88ebc38b381a1021fc2d74864a71e230ae591c3d /gl/alignof.h
parentc63a4f726a0b6ad8cf6040f947754a81fd4683bb (diff)
downloadmonitoring-plugins-74da141e618ef99959d509cb2e7be35a348a39db.tar.gz
Sync with the latest Gnulib code (177f525)
Signed-off-by: Thomas Guyot-Sionnest <dermoth@aei.ca>
Diffstat (limited to 'gl/alignof.h')
-rw-r--r--gl/alignof.h34
1 files changed, 27 insertions, 7 deletions
diff --git a/gl/alignof.h b/gl/alignof.h
index 896382b..240468c 100644
--- a/gl/alignof.h
+++ b/gl/alignof.h
@@ -1,5 +1,5 @@
1/* Determine alignment of types. 1/* Determine alignment of types.
2 Copyright (C) 2003-2004, 2006, 2009 Free Software Foundation, Inc. 2 Copyright (C) 2003-2004, 2006, 2009-2010 Free Software Foundation, Inc.
3 3
4 This program is free software; you can redistribute it and/or modify 4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by 5 it under the terms of the GNU General Public License as published by
@@ -20,14 +20,34 @@
20 20
21#include <stddef.h> 21#include <stddef.h>
22 22
23/* Determine the alignment of a type at compile time. */ 23/* Determine the alignment of a structure slot (field) of a given type,
24#if defined __GNUC__ 24 at compile time. Note that the result depends on the ABI.
25# define alignof __alignof__ 25 Note: The result cannot be used as a value for an 'enum' constant,
26#elif defined __cplusplus 26 due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc. */
27#if defined __cplusplus
27 template <class type> struct alignof_helper { char __slot1; type __slot2; }; 28 template <class type> struct alignof_helper { char __slot1; type __slot2; };
28# define alignof(type) offsetof (alignof_helper<type>, __slot2) 29# define alignof_slot(type) offsetof (alignof_helper<type>, __slot2)
30#else
31# define alignof_slot(type) offsetof (struct { char __slot1; type __slot2; }, __slot2)
32#endif
33
34/* Determine the good alignment of a object of the given type at compile time.
35 Note that this is not necessarily the same as alignof_slot(type).
36 For example, with GNU C on x86 platforms: alignof_type(double) = 8, but
37 - when -malign-double is not specified: alignof_slot(double) = 4,
38 - when -malign-double is specified: alignof_slot(double) = 8.
39 Note: The result cannot be used as a value for an 'enum' constant,
40 due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc. */
41#if defined __GNUC__
42# define alignof_type __alignof__
29#else 43#else
30# define alignof(type) offsetof (struct { char __slot1; type __slot2; }, __slot2) 44# define alignof_type alignof_slot
31#endif 45#endif
32 46
47/* alignof is an alias for alignof_slot semantics, since that's what most
48 callers need.
49 Note: The result cannot be used as a value for an 'enum' constant,
50 due to bugs in HP-UX 10.20 cc and AIX 3.2.5 xlc. */
51#define alignof alignof_slot
52
33#endif /* _ALIGNOF_H */ 53#endif /* _ALIGNOF_H */