Re: byte-compile-warn in do-after-load-evaluation - a bug?

[Alan Mackenzie]

Hello, Stefan.

On Fri, Jan 21, 2022 at 13:39:26 -0500, Stefan Monnier wrote:
> > Might it be that somebody not having a good day just used that function
> > thinking it was a general purpose warning function?

> No, and I think the code makes it pretty clear:

Sorry, yes it does.  I think it's me that's having the bad day.

>     [...]
>     (cond
>      ((bound-and-true-p byte-compile-current-file)
>       ;; Don't warn about obsolete files using other obsolete files.
>       (unless (and (stringp byte-compile-current-file)
>                    (string-match-p "/obsolete/[^/]*\\'"
>                                    (expand-file-name
>                                     byte-compile-current-file
>                                     byte-compile-root-dir)))
>         (byte-compile-warn "%s" msg)))
>     [...]

> The intention is to use this code when the load was performed by the
> byte-compiler (presumably because of a `require`).

I think I've got it sorted out, now.  By pushing an element onto
byte-compile-form-stack when handling a `require', we can ensure
byte-compile-warn will have something to chew on.
(scratch/correct-warning-pos branch.)

> > The problem with it is that it uses an implicit (compilation) source
> > position in the message it outputs.  There is no compilation going on at
> > the moment.

> I suspect that what we should do here is to make the byte-compiler
> provide more info.  E.g. instead of just testing
> `byte-compile-current-file`, which is a kind of "accidental" info, we
> should have `bytecomp.el` do a

>     (let ((byte-compile-triggered-load-source <sourcedata>))
>       ...)

> so `do-after-load-evaluation` can check this specific var and use its
> info to provide proper source information.

> WDYT?

I'm not convinced.  I think byte-compile-form-stack already provides (or
can provide) sufficient source position information.

>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).