OpenBSD-4.6/usr.sbin/afs/src/cf/check-declaration.m4

dnl $KTH: check-declaration.m4,v 1.2 1999/10/06 03:15:53 assar Exp $
dnl
dnl
dnl Check if we need the declaration of a variable
dnl

dnl AC_CHECK_DECLARATION(includes, variable)
AC_DEFUN(AC_CHECK_DECLARATION, [
AC_MSG_CHECKING([if $2 is properly declared])
AC_CACHE_VAL(ac_cv_var_$2_declaration, [
AC_TRY_COMPILE([$1
extern struct { int foo; } $2;],
[$2.foo = 1;],
eval "ac_cv_var_$2_declaration=no",
eval "ac_cv_var_$2_declaration=yes")
])

define(foo, [HAVE_]translit($2, [a-z], [A-Z])[_DECLARATION])

AC_MSG_RESULT($ac_cv_var_$2_declaration)
if eval "test \"\$ac_cv_var_$2_declaration\" = yes"; then
	AC_DEFINE(foo, 1, [define if your system declares $2])
fi
undefine([foo])
])