mirror of
https://sourceware.org/git/glibc.git
synced 2024-09-20 00:19:57 +00:00
8311c83f91
Do not use a statement expression in array_length, so that array_length can be used at file scope and as a constant expression. Instead, put the _Static_assert into a struct (as a declaration), and nest this in the expression using a sizeof expression.
37 lines
1.6 KiB
C
37 lines
1.6 KiB
C
/* The array_length and array_end macros.
|
|
Copyright (C) 2017-2019 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) \
|
|
(sizeof (var) / sizeof ((var)[0]) \
|
|
+ 0 * sizeof (struct { \
|
|
_Static_assert (!__builtin_types_compatible_p \
|
|
(__typeof (var), __typeof (&(var)[0])), \
|
|
"argument must be an array"); \
|
|
}))
|
|
|
|
/* 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 */
|