bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

[Eli Zaretskii]

I've noticed that the native-comp branch preloads pcase:

  Loading files (native compiled elisp)...
  Loading emacs-lisp/macroexp (native compiled elisp)...
  Loading emacs-lisp/pcase...
  Loading emacs-lisp/macroexp (native compiled elisp)...

whereas on master this doesn't happen.  Why is that?  Do we really
need to preload pcase?  If that's unavoidable, it should be added to
shortlisp, so that we eln-compile it.

In GNU Emacs 28.0.50 (build 1076, i686-pc-mingw32)
 of 2021-03-09 built on HOME-C4E4A596F7
Repository revision: 40d8f83e53ba64355035da78967c994d09a7802d
Repository branch: master
Windowing system distributor 'Microsoft Corp.', version 5.1.2600
System Description: Microsoft Windows XP Service Pack 3 (v5.1.0.2600)

Configured using:
 'configure -C --prefix=/d/usr --with-wide-int --with-modules
 --enable-checking=yes,glyphs 'CFLAGS=-O0 -gdwarf-4 -g3''

Configured features:
ACL GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES NOTIFY
W32NOTIFY PDUMPER PNG RSVG SOUND THREADS TIFF TOOLKIT_SCROLL_BARS XPM
ZLIB

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1255

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
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Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg epg-config gnus-util rmail
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eieio-loaddefs password-cache json map text-property-search time-date
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iso-transl tooltip eldoc electric uniquify ediff-hook vc-hooks
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w32-vars term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
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timer select scroll-bar mouse jit-lock font-lock syntax facemenu
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japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice button loaddefs faces cus-face macroexp files
window text-properties overlay sha1 md5 base64 format env code-pages
mule custom widget hashtable-print-readable backquote threads w32notify
w32 lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 56671 11176)
 (symbols 48 7803 1)
 (strings 16 21563 1999)
 (string-bytes 1 626919)
 (vectors 16 13076)
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bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

[Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Eli Zaretskii <eliz@gnu.org> writes:

> I've noticed that the native-comp branch preloads pcase:
>
>   Loading files (native compiled elisp)...
>   Loading emacs-lisp/macroexp (native compiled elisp)...
>   Loading emacs-lisp/pcase...
>   Loading emacs-lisp/macroexp (native compiled elisp)...
>
> whereas on master this doesn't happen.  Why is that?

Mmhh, I think is because of this from loadup.el:

====
(load "emacs-lisp/macroexp")
(if (byte-code-function-p (symbol-function 'macroexpand-all))
    nil
  ;; Since loaddefs is not yet loaded, macroexp's uses of pcase will simply
  ;; fail until pcase is explicitly loaded.  This also means that we have to
  ;; disable eager macro-expansion while loading pcase.
  (let ((macroexp--pending-eager-loads '(skip))) (load "emacs-lisp/pcase"))
  ;; Re-load macroexp so as to eagerly macro-expand its uses of pcase.
  (let ((max-lisp-eval-depth (* 2 max-lisp-eval-depth)))
    (load "emacs-lisp/macroexp")))
====

> need to preload pcase?

I fear I don't have an answer as ATM I don't uderstand why it should be
different compared to master.

  Andrea

bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

[Eli Zaretskii]

> From: Andrea Corallo <akrl@sdf.org>
> Cc: 47025@debbugs.gnu.org
> Date: Tue, 09 Mar 2021 20:21:21 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I've noticed that the native-comp branch preloads pcase:
> >
> >   Loading files (native compiled elisp)...
> >   Loading emacs-lisp/macroexp (native compiled elisp)...
> >   Loading emacs-lisp/pcase...
> >   Loading emacs-lisp/macroexp (native compiled elisp)...
> >
> > whereas on master this doesn't happen.  Why is that?
> 
> Mmhh, I think is because of this from loadup.el:
> 
> ====
> (load "emacs-lisp/macroexp")
> (if (byte-code-function-p (symbol-function 'macroexpand-all))
>     nil
>   ;; Since loaddefs is not yet loaded, macroexp's uses of pcase will simply
>   ;; fail until pcase is explicitly loaded.  This also means that we have to
>   ;; disable eager macro-expansion while loading pcase.
>   (let ((macroexp--pending-eager-loads '(skip))) (load "emacs-lisp/pcase"))
>   ;; Re-load macroexp so as to eagerly macro-expand its uses of pcase.
>   (let ((max-lisp-eval-depth (* 2 max-lisp-eval-depth)))
>     (load "emacs-lisp/macroexp")))
> ====
> 
> > need to preload pcase?
> 
> I fear I don't have an answer as ATM I don't uderstand why it should be
> different compared to master.

Stefan, any ideas why this happens on the native-comp branch but not
on master?

bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

[Stefan Monnier]

>> (load "emacs-lisp/macroexp")
>> (if (byte-code-function-p (symbol-function 'macroexpand-all))
>>     nil
>>   ;; Since loaddefs is not yet loaded, macroexp's uses of pcase will simply
>>   ;; fail until pcase is explicitly loaded.  This also means that we have to
>>   ;; disable eager macro-expansion while loading pcase.
>>   (let ((macroexp--pending-eager-loads '(skip))) (load "emacs-lisp/pcase"))
>>   ;; Re-load macroexp so as to eagerly macro-expand its uses of pcase.
>>   (let ((max-lisp-eval-depth (* 2 max-lisp-eval-depth)))
>>     (load "emacs-lisp/macroexp")))
>> ====
>> 
>> > need to preload pcase?
>> 
>> I fear I don't have an answer as ATM I don't uderstand why it should be
>> different compared to master.
>
> Stefan, any ideas why this happens on the native-comp branch but not
> on master?

It's probably the `byte-code-function-p` which tries to distinguish the
case where macroexp has not yet been compiled, but on the native branch,
I suspect that (byte-code-function-p (symbol-function 'macroexpand-all))
will return nil when macroexp has been compiled because it's now
a `subrp`.

So we could replace

    (byte-code-function-p (symbol-function 'macroexpand-all))

with

    (or (byte-code-function-p (symbol-function 'macroexpand-all))
        (subrp (symbol-function 'macroexpand-all)))

or with

    (not (consp (symbol-function 'macroexpand-all)))


-- Stefan

bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

[Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors]

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

>>> (load "emacs-lisp/macroexp")
>>> (if (byte-code-function-p (symbol-function 'macroexpand-all))
>>>     nil
>>>   ;; Since loaddefs is not yet loaded, macroexp's uses of pcase will simply
>>>   ;; fail until pcase is explicitly loaded.  This also means that we have to
>>>   ;; disable eager macro-expansion while loading pcase.
>>>   (let ((macroexp--pending-eager-loads '(skip))) (load "emacs-lisp/pcase"))
>>>   ;; Re-load macroexp so as to eagerly macro-expand its uses of pcase.
>>>   (let ((max-lisp-eval-depth (* 2 max-lisp-eval-depth)))
>>>     (load "emacs-lisp/macroexp")))
>>> ====
>>> 
>>> > need to preload pcase?
>>> 
>>> I fear I don't have an answer as ATM I don't uderstand why it should be
>>> different compared to master.
>>
>> Stefan, any ideas why this happens on the native-comp branch but not
>> on master?
>
> It's probably the `byte-code-function-p` which tries to distinguish the
> case where macroexp has not yet been compiled, but on the native branch,
> I suspect that (byte-code-function-p (symbol-function 'macroexpand-all))
> will return nil when macroexp has been compiled because it's now
> a `subrp`.

Ops should have spotted that :/ thanks for the suggestion.

711b2c8349 fix this for me.

Eli let me know if we are okay to close.

Thanks

  Andrea

bug#47025: 28.0.50; [feature/native-comp] pcase is preloaded, but not eln-compiled

[Eli Zaretskii]

> From: Andrea Corallo <akrl@sdf.org>
> Cc: Eli Zaretskii <eliz@gnu.org>, 47025@debbugs.gnu.org
> Date: Wed, 10 Mar 2021 15:22:45 +0000
> 
> > It's probably the `byte-code-function-p` which tries to distinguish the
> > case where macroexp has not yet been compiled, but on the native branch,
> > I suspect that (byte-code-function-p (symbol-function 'macroexpand-all))
> > will return nil when macroexp has been compiled because it's now
> > a `subrp`.
> 
> Ops should have spotted that :/ thanks for the suggestion.
> 
> 711b2c8349 fix this for me.
> 
> Eli let me know if we are okay to close.

This is fixed, closing.

Thanks.