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author | Florian Weimer <fweimer@redhat.com> | 2017-11-02 12:14:01 +0100 |
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committer | Aurelien Jarno <aurelien@aurel32.net> | 2017-12-16 14:44:54 +0100 |
commit | 6474863dcb277eaeeff47a5f53de424ec49dd03d (patch) | |
tree | 507a39733ed2fc20ec985d6c89618df5e18d0781 | |
parent | 17357d93cbf8d71a12530e91ea405cea4adb5ab0 (diff) | |
download | glibc-6474863dcb277eaeeff47a5f53de424ec49dd03d.tar.gz glibc-6474863dcb277eaeeff47a5f53de424ec49dd03d.tar.xz glibc-6474863dcb277eaeeff47a5f53de424ec49dd03d.zip |
<array_length.h>: New array_length and array_end macros
(cherry picked from commit c94a5688fb1228a862b2d4a3f1239cdc0e3349e5)
-rw-r--r-- | ChangeLog | 5 | ||||
-rw-r--r-- | include/array_length.h | 36 |
2 files changed, 41 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 574ea60130..4334e6ec39 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2017-11-02 Florian Weimer <fweimer@redhat.com> + + Add array_length and array_end macros. + * include/array_length.h: New file. + 2017-12-12 James Clarke <jrtc27@jrtc27.com> * sysdeps/unix/sysv/linux/ia64/ipc_priv.h: New file defining diff --git a/include/array_length.h b/include/array_length.h new file mode 100644 index 0000000000..cb4a8b2a56 --- /dev/null +++ b/include/array_length.h @@ -0,0 +1,36 @@ +/* The array_length and array_end macros. + Copyright (C) 2017 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 _ARRAY_LENGTH_H +#define _ARRAY_LENGTH_H + +/* array_length (VAR) is the number of elements in the array VAR. VAR + must evaluate to an array, not a pointer. */ +#define array_length(var) \ + __extension__ ({ \ + _Static_assert (!__builtin_types_compatible_p \ + (__typeof (var), __typeof (&(var)[0])), \ + "argument must be an array"); \ + sizeof (var) / sizeof ((var)[0]); \ + }) + +/* array_end (VAR) is a pointer one past the end of the array VAR. + VAR must evaluate to an array, not a pointer. */ +#define array_end(var) (&(var)[array_length (var)]) + +#endif /* _ARRAY_LENGTH_H */ |