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dnl Copyright (C) 2004-2008 Kim Woelders
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dnl Copyright (C) 2008 Vincent Torri <vtorri at univ-evry dot fr>
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dnl That code is public domain and can be freely used or copied.
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dnl Originally snatched from somewhere...
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dnl Macro for checking if the compiler supports __attribute__
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dnl Usage: AC_C___ATTRIBUTE__
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dnl call AC_DEFINE for HAVE___ATTRIBUTE__ and __UNUSED__
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dnl if the compiler supports __attribute__, HAVE___ATTRIBUTE__ is
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dnl defined to 1 and __UNUSED__ is defined to __attribute__((unused))
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dnl otherwise, HAVE___ATTRIBUTE__ is not defined and __UNUSED__ is
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dnl defined to nothing.
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AC_DEFUN([AC_C___ATTRIBUTE__],
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AC_MSG_CHECKING([for __attribute__])
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AC_CACHE_VAL([ac_cv___attribute__],
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int foo(int x __attribute__ ((unused)))
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[ac_cv___attribute__="yes"],
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[ac_cv___attribute__="no"]
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AC_MSG_RESULT($ac_cv___attribute__)
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if test "x${ac_cv___attribute__}" = "xyes" ; then
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AC_DEFINE([HAVE___ATTRIBUTE__], [1], [Define to 1 if your compiler has __attribute__])
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AC_DEFINE([__UNUSED__], [__attribute__((unused))], [Macro declaring a function argument to be unused])
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AC_DEFINE([__UNUSED__], [], [Macro declaring a function argument to be unused])
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dnl End of ac_attribute.m4