build: Add $(NULL) as a convenient list terminator

When building lists of things in Makefiles it's convenient to have a
list terminator to avoid hanging backslash problems.  eg:

  EXTRA_DIST = \
           thing1 \
           thing2 \
           $(NULL)

Cherry picked from virt-v2v commit 09b86c07bf19beba9ccb8fcca0ebfae34dd56406
Cherry picked from guestfs-tools commit dad8c0d3803dcbc91e22ca35c630d9e8a01df81b
This commit is contained in:
Richard W.M. Jones
2025-09-22 10:58:29 +01:00
parent a5925f5e14
commit eed58cc443

View File

@@ -20,6 +20,10 @@
-include $(top_builddir)/localenv
# Convenient way to terminate lists in Makefiles, so that we avoid
# problems with dangling backslashes.
NULL =
# Files that should universally be removed by 'make clean'. Note if
# there is any case in any subdirectory where a file should not be
# removed by 'make clean', it should not be listed here!