find-dir-with = $(shell /usr/bin/perl -e 'chomp($$_ = `pwd`); while ($$_ ne "" && ! -e "$$_/$(1)") { m:(.*)/[^/]+/??:; $$_ = $$1; } print;')

# define canonical directories in starsearch
ifndef TOP_DIR
  export TOP_DIR := $(call find-dir-with,.SD-VBS)
endif

export MAKEFILE_COMMON_DIR=$(TOP_DIR)/common/makefiles

# backward compatibility

ifeq ($(TOP_DIR),)
$(error file .SD-VBS not found -- try running 'gmake setup' at the top of your source tree)
endif