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