Possible build configurations

Possible build configurations

[Stefan Monnier]

Is it currently possible to have

    (featurep 'xinput2)

or

    (featurep 'x)

be true at the same time as

    (or (featurep 'w32-win) (featurep 'ns-win)
        (featurep 'haiku-win) (featurep 'pgtk-win)
        (featurep 'android-win))

?

According to my reading of the code, the answer is no: these features
are all defined in their respective `<GUI>term.c` or `<GUI>fns.c` and
the current `configure.ac` (and I think current C code) supports only
a single <GUI> active at the same time.

Can someone confirm this?


        Stefan

Re: Possible build configurations

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Sat, 20 Jan 2024 12:54:38 -0500
> 
> Is it currently possible to have
> 
>     (featurep 'xinput2)
> 
> or
> 
>     (featurep 'x)
> 
> be true at the same time as
> 
>     (or (featurep 'w32-win) (featurep 'ns-win)
>         (featurep 'haiku-win) (featurep 'pgtk-win)
>         (featurep 'android-win))
> 
> ?
> 
> According to my reading of the code, the answer is no: these features
> are all defined in their respective `<GUI>term.c` or `<GUI>fns.c` and
> the current `configure.ac` (and I think current C code) supports only
> a single <GUI> active at the same time.
> 
> Can someone confirm this?

The FOO-win features are provided by the corresponding FOO-win.el
files in lisp/term/, not by FOOterm.c.  So I'm not sure what you are
asking about here.  For example, my rading of the code is that 'x and
'xinput2 _can_ coexist with 'pgtk-win (but not with any other FOO-win,
AFAICT).

Re: Possible build configurations

[Stefan Monnier]

> The FOO-win features are provided by the corresponding FOO-win.el
> files in lisp/term/, not by FOOterm.c.

Oh, right, I was confusing the `<GUI>` and `<GUI>-win` features.
This said, the `<GUI>-win.el` files are loaded by `loadup.el` only
when the corresponding `<GUI>` is defined and those are defined
in `<GUI>term.c`, so I think the end result is "the same".

> So I'm not sure what you are asking about here.  For example, my
> rading of the code is that 'x and 'xinput2 _can_ coexist with
> 'pgtk-win (but not with any other FOO-win, AFAICT).

Hmm... interesting.  `pgtk-win` is provided by `pgtk-win.el`
which is loaded in loadup via:

    (if (featurep 'pgtk)
        (progn
          (load "pgtk-dnd")
          (load "term/common-win")
          (load "term/pgtk-win")))

so it's only defined if the `pgtk` feature is provided.  In turn

    grep Fprovide.\*pgtk ~/src/emacs/main/src/**/*.[ch]

suggests it's provided only by `pgtkterm.c` and my reading of
`configure.ac` suggests `pgtkterm.c` and `xfns.c` (the file where
`xinput2` and `x` are provided) can't be both linked into the `emacs`
executable at the same time.

Am I missing something?


        Stefan


PS: As for why I'm asking, this is basically to determine if

    ;; FIXME: Yuck!
    (if (or (featurep 'w32-win) (featurep 'ns-win)
            (featurep 'haiku-win) (featurep 'pgtk-win)
            (featurep 'android-win))
        (if (featurep 'xinput2)
            nil
          (unless (featurep 'x)
            t))
      t)

is just a roundabout way to write `t`.

Re: Possible build configurations

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: emacs-devel@gnu.org
> Date: Sat, 20 Jan 2024 15:06:41 -0500
> 
> > So I'm not sure what you are asking about here.  For example, my
> > rading of the code is that 'x and 'xinput2 _can_ coexist with
> > 'pgtk-win (but not with any other FOO-win, AFAICT).
> 
> Hmm... interesting.  `pgtk-win` is provided by `pgtk-win.el`
> which is loaded in loadup via:
> 
>     (if (featurep 'pgtk)
>         (progn
>           (load "pgtk-dnd")
>           (load "term/common-win")
>           (load "term/pgtk-win")))
> 
> so it's only defined if the `pgtk` feature is provided.  In turn
> 
>     grep Fprovide.\*pgtk ~/src/emacs/main/src/**/*.[ch]
> 
> suggests it's provided only by `pgtkterm.c` and my reading of
> `configure.ac` suggests `pgtkterm.c` and `xfns.c` (the file where
> `xinput2` and `x` are provided) can't be both linked into the `emacs`
> executable at the same time.
> 
> Am I missing something?

I think I confused pgtk with gtk.

Re: Possible build configurations

[Po Lu]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Is it currently possible to have
>
>     (featurep 'xinput2)
>
> or
>
>     (featurep 'x)
>
> be true at the same time as

Not as yet, thanks.

>     (or (featurep 'w32-win) (featurep 'ns-win)
>         (featurep 'haiku-win) (featurep 'pgtk-win)
>         (featurep 'android-win))
>
> ?
>
> According to my reading of the code, the answer is no: these features
> are all defined in their respective `<GUI>term.c` or `<GUI>fns.c` and
> the current `configure.ac` (and I think current C code) supports only
> a single <GUI> active at the same time.
>
> Can someone confirm this?

This is correct.

Re: Possible build configurations

[Stefan Monnier]

>> be true at the same time as
> Not as yet, thanks.

Thank you (and Eli as well) for confirming my suspicion.
So I simplified the `mwheel.el` code accordingly.


        Stefan