+AX_PTHREAD(,AC_MSG_ERROR([Missing POSIX Threads support]))
+
+if test x"$ac_cv_prog_cc_c99" = x"no"; then
+ AC_MSG_ERROR([C99 support is required])
+fi
+
+# Windows stuff
+AC_CHECK_DECL(_WIN32)
+AM_CONDITIONAL([WINDOWS], [ test "x$ac_cv_have_decl__WIN32" = "xyes" ])
+if test "x$ac_cv_have_decl__WIN32" = "xyes" ; then
+ CPPFLAGS="$CPPFLAGS -I`pwd`/src/compat/windows/include"
+fi
+AC_CHECK_MEMBER([struct in_pktinfo.ipi_spec_dst],
+ AC_DEFINE([HAVE_IPI_SPEC_DST], [], [struct in_pktinfo has ipi_spec_dst member]),
+ [],
+ [[#include <netinet/in.h>]])
+
+# iOS stuff
+AC_CHECK_DECL(__APPLE__)
+AM_CONDITIONAL([APPLE], [ test "x$ac_cv_have_decl___APPLE__" = "xyes" ])
+if test "x$ac_cv_have_decl___APPLE__" = "xyes" ; then
+ CPPFLAGS="$CPPFLAGS -I`pwd`/src/compat/ios/include"
+fi