25 lines
1 KiB
Text
25 lines
1 KiB
Text
dnl Copyright (C) 2015 Free Software Foundation, Inc.
|
|
dnl This file is free software, distributed under the terms of the GNU
|
|
dnl General Public License. As a special exception to the GNU General
|
|
dnl Public License, this file may be distributed as part of a program
|
|
dnl that contains a configuration script generated by Autoconf, under
|
|
dnl the same distribution terms as the rest of that program.
|
|
|
|
# Define HAVE_BITFIELD_TYPE_MATTERS if the type of bitfields effects their
|
|
# alignment.
|
|
|
|
AC_DEFUN([gt_BITFIELD_TYPE_MATTERS],
|
|
[
|
|
AC_CACHE_CHECK([if the type of bitfields matters], gt_cv_bitfield_type_matters,
|
|
[
|
|
AC_TRY_COMPILE(
|
|
[struct foo1 { char x; char y:1; char z; };
|
|
struct foo2 { char x; long long int y:1; char z; };
|
|
int foo1test[ sizeof (struct foo1) < sizeof (struct foo2) ? 1 : -1 ]; ],
|
|
[], gt_cv_bitfield_type_matters=yes, gt_cv_bitfield_type_matters=no)
|
|
])
|
|
if test $gt_cv_bitfield_type_matters = yes; then
|
|
AC_DEFINE(HAVE_BITFIELD_TYPE_MATTERS, 1,
|
|
[Define if the type of bitfields effects alignment.])
|
|
fi
|
|
])
|