make describe-function link to org file for "tangled" lisp functions

Question

I have a lot of my emacs configuration in an org babel file, which I load with org-babel-load-file. My configuration is in my-emacs-config.org.

When I use describe-function for one of the functions I define there, it links to the tangled .el file, but I'd like it to link to my org file.

For example:

my-function is a Lisp function in ‘../my-emacs-config.el’.

(my-function)

Blah blah documentation for my function here.

[back]

The ../my-emacs-config.el is a link. But I want that to link to ../my-emacs-config.org -- the original org source file.

Note that the manual has a bit on the :comments link header argument (see here) but that just seems to put an org-mode style link at the top of the output .el file. I want something that advises describe-function or somehow gives me a link to the org source file.

Any ideas?

Answer 1

Thanks to @NickD and the magic of :filter-return advice, this turns out to be super simple: we write a function that akes the file name that find-lisp-object-file-name returns, and for those that came from our literate org files, change the .el to .org.

For my setup, here's all I need to do:

(defun filter-find-lisp-object-file-name (fn)
  "If the output of `find-lisp-object-file-name' is config.el,
change that to config.org; otherwise, this is the identity
 function."
  (if (string= fn "/home/dan/.emacs.d/my-emacs-config.el")
      "/home/dan/.emacs.d/my-emacs-config.org"
      fn))

(advice-add 'find-lisp-object-file-name :filter-return #'filter-find-lisp-object-file-name)

The filter-return advice function is very simple: it just needs some logic to identify the .el files that come from my literate .org files, and to change those appropriately. In my case, there's only one, so the logic is very simple, but it would be straightforward to do some parsing of the path or other logic. For anything not from my configuration, the filter just passes through the file name.