How to avoid "unknown function" warning for *very* optional functional

How to avoid "unknown function" warning for *very* optional functional

[Konstantin Kharlamov]

I'm fixing warnings in some of Emacs packages I'm using, and I found in
`meson-mode` this construct:

    (defun meson-lookup-doc (identifier)
    …
            (when (bound-and-true-p evil-mode)
              (evil-local-set-key 'normal (kbd "q") 'bury-buffer)))
    …

This basically a small help to those using both evil-mode and `meson-mode`. And this
triggers a byte-compilation warning:

    meson-mode.el:958:12: Warning: the function ‘evil-local-set-key’ is not known to be defined.

I'm not exactly sure what's the proper way to fix this? It's not even an optional
package, so `require` or `(cl-eval-when 'compile …` are not suitable here. It's just
that: "change behavior in this one function if another mode is present".

Re: How to avoid "unknown function" warning for *very* optional functional

[Joost Kremers]

On Sat, Feb 10 2024, Konstantin Kharlamov wrote:
> I'm fixing warnings in some of Emacs packages I'm using, and I found in
> `meson-mode` this construct:
>
>     (defun meson-lookup-doc (identifier)
>     …
>             (when (bound-and-true-p evil-mode)
>               (evil-local-set-key 'normal (kbd "q") 'bury-buffer)))
>     …
>
> This basically a small help to those using both evil-mode and `meson-mode`. And this
> triggers a byte-compilation warning:
>
>     meson-mode.el:958:12: Warning: the function ‘evil-local-set-key’ is not known to be defined.
>
> I'm not exactly sure what's the proper way to fix this? It's not even an optional
> package, so `require` or `(cl-eval-when 'compile …` are not suitable here. It's just
> that: "change behavior in this one function if another mode is present".

You can use `declare-function` to let the byte-compiler know that the function
exists but that there is no need to actually check to make sure.


-- 
Joost Kremers
Life has its moments

Re: How to avoid "unknown function" warning for *very* optional functional

[Konstantin Kharlamov]

Thank you, that works!

On Sat, 2024-02-10 at 01:08 +0100, Joost Kremers wrote:
> 
> On Sat, Feb 10 2024, Konstantin Kharlamov wrote:
> > I'm fixing warnings in some of Emacs packages I'm using, and I
> > found in
> > `meson-mode` this construct:
> > 
> >     (defun meson-lookup-doc (identifier)
> >     …
> >             (when (bound-and-true-p evil-mode)
> >               (evil-local-set-key 'normal (kbd "q") 'bury-buffer)))
> >     …
> > 
> > This basically a small help to those using both evil-mode and
> > `meson-mode`. And this
> > triggers a byte-compilation warning:
> > 
> >     meson-mode.el:958:12: Warning: the function ‘evil-local-set-
> > key’ is not known to be defined.
> > 
> > I'm not exactly sure what's the proper way to fix this? It's not
> > even an optional
> > package, so `require` or `(cl-eval-when 'compile …` are not
> > suitable here. It's just
> > that: "change behavior in this one function if another mode is
> > present".
> 
> You can use `declare-function` to let the byte-compiler know that the
> function
> exists but that there is no need to actually check to make sure.