+# You can override this variable in cfg.mk to set your own regexp
+# matching files to ignore.
+VC_LIST_ALWAYS_EXCLUDE_REGEX ?= ^$$
+
+# This is to preprocess robustly the output of $(VC_LIST), so that even
+# when $(srcdir) is a pathological name like "....", the leading sed command
+# removes only the intended prefix.
+_dot_escaped_srcdir = $(subst .,\.,$(srcdir))
+
+# Post-process $(VC_LIST) output, prepending $(srcdir)/, but only
+# when $(srcdir) is not ".".
+ifeq ($(srcdir),.)
+_prepend_srcdir_prefix =
+else
+_prepend_srcdir_prefix = | sed 's|^|$(srcdir)/|'
+endif
+
+# In order to be able to consistently filter "."-relative names,
+# (i.e., with no $(srcdir) prefix), this definition is careful to
+# remove any $(srcdir) prefix, and to restore what it removes.