bug#60568: [FR] 30.0.50; Help buffers and function bodies for generated functions

["Daniel Martín via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Ihor Radchenko <yantar92@posteo.net> writes:

> Recently, we have stumbled upon a situation when showing function code
> is not only useful, but one of the few sane ways to examine it [3].
> Functions that are not directly written in the source but rather
> generated programmatically cannot currently be easily examined using
> built-in help functionality (using describe-function or other means).
> The help buffer only links to the (point-min) in the library defining
> the generated function - not very helpful. In contrast, helpful extracts
> function body from symbol function slot.

I'd prefer we teach the Help facilities how to go to the source code of
that kind of functions.  Some years ago, I added support for go to
definition from *Help* buffers when the symbol was generated by a Lisp
macro; there's no reason we couldn't extend the code to also handle this
particular case.

Showing the source code inline is something I feel more suitable for
third-party packages.  It is probably more interesting from a core Emacs
perspective to make sure that help-mode provides the appropriate hooks
for users and packages to customize what to show without needing to
reimplement *Help* from scratch.  I don't know what other people think,
my opinion about this may be a minority.