+if test "x$ac_cv_lib_pthread_pthread_exit" != "xyes" -a "x$ac_cv_header_pthread_h" = "xyes"; then
+ dnl FreeBSD: System has pthread.h, but -lpthread library check
+ dnl fails. See if we need -pthread instead of -lpthread and look
+ dnl for the functions in libc_r.
+ save_CXXFLAGS="$CXXFLAGS"
+ save_CFLAGS="$CFLAGS"
+ CXXFLAGS="-pthread $CXXFLAGS"
+ CFLAGS="-pthread $FLAGS"
+ save_LIBS=$LIBS
+ AC_CHECK_LIB(c_r, pthread_exit)
+ if test "x$ac_cv_lib_c_r_pthread_exit" != "xyes"; then
+ CXXFLAGS=$save_CXXFLAGS
+ CFLAGS=$save_CFLAGS
+ else
+ dnl This is cheating a bit. pthread_exit comes with using -pthread, not -lpthread
+ ac_cv_lib_pthread_pthread_exit="yes"
+ fi
+ LIBS=$save_LIBS
+fi