bug#15252: dir-locals: superdir (or parentdir) support

bug#15252: dir-locals: superdir (or parentdir) support

[Jambunathan K]

Introductory word:

I am having a private library that implements a unified search
interface.  It will use `cscope' as search engine while visiting *.[ch]
files and `rgrep' as search engine while visiting *.el files.  

The search as it stands will be on the whole of search tree.

It is "specified" in as .dir-locals.el as below.


~/src/emacs/trunk/.dir-locals.el:

    ((c-mode
      (search-dir . "~/src/emacs/trunk/")
      (search-engine . cscope))
     (emacs-lisp-mode
      (search-dir . "~/src/emacs/trunk/lisp")
      (search-engine . rgrep)))

----------------------------------------------------------------

Problem:


If I am visiting an Org file (say trunk/lisp/org/org.el), the recursive
search *on whole lisp tree* happens just fine.

But if I am visiting a Gnus file (say trunk/lisp/org/org.el), the
recursive search fails.


----------------------------------------------------------------

Diagnosis:


The reason is this because Gnus has it's own .dir-locals.el for lisp
files.

~/src/emacs/trunk/lisp/gnus/.dir-locals.el:

    ((emacs-lisp-mode . ((show-trailing-whitespace . t))))


----------------------------------------------------------------

What I need:

So to realize my use case, I want that the "emacs-lisp-mode" settings
from Gnus tree be merged with that specified from trunk.

----------------------------------------------------------------

One possible way to achieve it:


Introduce a `superdir' or a `parentdir' keyword, to traverse till the
root.

~/src/emacs/trunk/lisp/gnus/.dir-locals.el:

    ((emacs-lisp-mode . ((show-trailing-whitespace . t)
			 (superdir . t) ; <=====================
			 )))


Compare `superdir' to the already existing `subdir'.  From 

(info "(emacs) Directory Variables")

    ((c-mode . ((c-file-style . "BSD")
                (subdirs . nil) ; <=====================
                )))

----------------------------------------------------------------

Closing note:

Particularly useful for "submodules" which are part of a "sumo" project.

bug#15252: dir-locals: superdir (or parentdir) support

[Glenn Morris]

Known issue, eg

http://lists.gnu.org/archive/html/emacs-devel/2013-04/msg00663.html

(Copyright assigned) patches for dir-locals inheritance welcome.

bug#15252: dir-locals: superdir (or parentdir) support

[Jambunathan K]

Glenn

Glenn Morris <rgm@gnu.org> writes:

> (Copyright assigned) patches

Always vigilant!

I thought Emacs project has my future assingments on paper.  As far as
my understanding of law goes, the annulment of contract doesn't take
effect until it is signed off both the parties.

Anyways...

Jambunathan K.

bug#15252: dir-locals: superdir (or parentdir) support

[Eli Zaretskii]

> From: Jambunathan K <kjambunathan@gmail.com>
> Date: Sat, 14 Sep 2013 14:15:16 +0530
> Cc: 15252@debbugs.gnu.org
> 
> > (Copyright assigned) patches
> 
> Always vigilant!
> 
> I thought Emacs project has my future assingments on paper.  As far as
> my understanding of law goes, the annulment of contract doesn't take
> effect until it is signed off both the parties.

Your assignment appears as "canceled on 2013-4-2" in the FSF records
since last April.

bug#15252: dir-locals: superdir (or parentdir) support

[Jambunathan K]

OP here.  Closed.