Coverage check for data files inclusion in dist

[Christian Egli]

Hi all

I work in a project where we ship a lot of data files. These files sit
in a subdirectory where Makefile.am lists them explicitly as follows:

table_files = \
        ar-ar-g1.utb \
        ...
        zh-tw.ctb

tablesdir = $(datadir)/liblouis/tables
tables_DATA = $(table_files)
EXTRA_DIST = $(table_files)

Now as we get a lot of these files contributed the maintenance of this
list becoming hard to manage. There are currently around 120 entries.
The main developer has been asking for some automated maintenance of
this list. I read the entry about wildcards in the FAQ and generally
agree with it, so I'd rather not generate the list in an automated way. 

But as a compromise would it maybe be possible to have some form of
coverage check that takes the table_files variable and checks if there
are files in the directory that are not listed (aside from the obvious
Makefile.am and Makefile)? Anyone have some code snippets to share? I
checked gnulib but it doesn't seem to contain anything like that.

Thanks
Christian