[Rd] R CMD build: "Subdirectory 'R' contains invalid file names"

[Henrik Bengtsson]

Hi, I get

* excluding invalid files from 'R.oo'
Subdirectory 'R' contains invalid file names:
  attachLocally.Object.Rex Exception.Rex extend.default.Rex
  InternalErrorException.reportBug.Rex Package.Rex Person.Rex Rdoc.Rex
  setMethodS3.Rex StaticFields.Rex

when running R CMD build in R v2.3.0 devel.  I do understand what is
going on.  In my *.R files I keep so called Rdoc comments which in
their simplest form are Rd code wrapped up in plain comments.  These
are compiled into Rd files written to ../man/ (I do this prior to
building packages).  Rdoc also supports inclusion of other files, e.g.
@include "Person.Rex" to include example code.

With this structure I can, when I develop/maintain a package, have
<pkg>/R/ as the working directory, modify my *.R files and re-source
them from within R.  Since I keep all my Rd example code in separate
*.Rex files, I can easily rerun/test these by sourcing them too.  I
find this very convenient.

In previous versions, the *.Rex files was included when building a
source distribution of a package.  In R v2.3.0 they are excluded. 
However, I would like to distribute the *.Rex files with my
source-code package too (so I do not have to keep another type of
source distribution).  Note that these files are only needed for
further development of the package, but *not* to install the package
from source (since their contents is already incorporated in the Rd
files).  They are also not of interest to the end-user.

My question is how to incorporate the *.Rex files?  Here are some
ideas, that I would like to have some feedback on:

1) Put them in <pkg>/R/Rex/*.Rex.  However, Section 1.1.4 in Writing R
Extensions suggest that subdirectories of R/ may only(?) be named
'windows' or 'unix'.

2) Rename them to <pkg>/R/*.in, cf. Section 1.1.4.  Is this the
purpose of *.in files?  Will it have side effects?

3) Put the in <pkg>/inst/<dir>/*.Rex.  This will work, but then they
will also be install and available in system.file("<dir>",
package="<pkg>").  Not a big problem, but not what I want.

4) To avoid (3), put the in <pkg>/<dir>/*.Rex, i.e. at the top level
directory.  Is this allowed?  Section 1.1.4 says "Note that [...]
information files at the top level of the package will not be
installed". Does this mean that they will be included in the source
distribution and what about top level directories?

5) Put the in <pkg>/src/*.Rex.  Can src/ be used this way too?

6) Ask R-core to revert back to pre-R v2.3.0 and allow other files in
the R/ directory too.  Are more people than I interested in this?

I realize I can test the above by trial and error, but I will still
not be sure what is the right approach here.  Comments/feedback is
appreciated.

Thanks

Henrik