+
+dnl
+dnl Check to see whether CC (gcc) supports a particular option.
+dnl
+AC_DEFUN(FPTOOLS_CC_FLAG,
+[
+AC_CACHE_CHECK([whether $CC accepts $1], [ac_cv_cc_$2],
+[save_CFLAGS="$CFLAGS"
+ CFLAGS="$CFLAGS $1"
+ AC_LANG_C
+ AC_TRY_COMPILE(,[int main(){return(0);}],
+ [ac_cv_cc_$2=yes],
+ [ac_cv_cc_$2=no])
+ CFLAGS="$save_CFLAGS"
+])
+if test "$ac_cv_cc_$2"x = "yesx"; then
+ $2=$1;
+else
+ $2="";
+fi;
+])
+
+dnl
+dnl Check to see whether 'struct msghdr' contains msg_control
+dnl
+AC_DEFUN(FPTOOLS_MSGHDR_MSG_CONTROL,
+[AC_CACHE_CHECK([for msg_control in struct msghdr], fptools_cv_struct_msghdr_msg_control,
+[AC_TRY_COMPILE([#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/socket.h>], [struct msghdr m; m.msg_control;],
+fptools_cv_struct_msghdr_msg_control=yes, fptools_cv_struct_msghdr_msg_control=no)])
+if test $fptools_cv_struct_msghdr_msg_control = yes; then
+ AC_DEFINE(HAVE_MSGHDR_MSG_CONTROL)
+fi
+AC_SUBST(HAVE_MSGHDR_MSG_CONTROL)dnl
+])
+
+dnl
+dnl Check to see whether 'struct msghdr' contains msg_accrights
+dnl
+AC_DEFUN(FPTOOLS_MSGHDR_MSG_ACCRIGHTS,
+[AC_CACHE_CHECK([for msg_accrights in struct msghdr], fptools_cv_struct_msghdr_msg_accrights,
+[AC_TRY_COMPILE([#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/socket.h>], [struct msghdr m; m.msg_accrights;],
+fptools_cv_struct_msghdr_msg_accrights=yes, fptools_cv_struct_msghdr_msg_accrights=no)])
+if test $fptools_cv_struct_msghdr_msg_accrights = yes; then
+ AC_DEFINE(HAVE_MSGHDR_MSG_ACCRIGHTS)
+fi
+AC_SUBST(HAVE_MSGHDR_MSG_ACCRIGHTS)dnl
+])
+