gcc/config/bitfields.m4
Trevor Saunders 539280a8e8 fixup libobjc usage of PCC_BITFIELD_TYPE_MATTERS
libobjc/ChangeLog:

2015-05-01  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* acinclude.m4: Include bitfields.m4.
	* config.h.in: Regenerate.
	* configure: Likewise.
	* configure.ac: Invoke gt_BITFIELD_TYPE_MATTERS.
	* encoding.c: Check HAVE_BITFIELD_TYPE_MATTERS.

config/ChangeLog:

2015-05-01  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* bitfields.m4: New file.

From-SVN: r222715
2015-05-02 04:11:07 +00:00

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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 :0; char y; };
struct foo2 { char x; int :0; char y; };
int foo1test[ sizeof (struct foo1) == 2 ? 1 : -1 ];
int foo2test[ sizeof (struct foo2) == 5 ? 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
])