GNU bug report logs - #67455
Record source position, etc., in doc strings, and use this in *Help* and backtraces.

Previous Next

Full log

Message #37 received at 67455 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Alan Mackenzie <acm <at> muc.de>
Cc: Eli Zaretskii <eliz <at> gnu.org>, 67455 <at> debbugs.gnu.org
Subject: Re: bug#67455: (Record source position, etc., in doc strings, and
 use this in *Help* and backtraces.)
Date: Sat, 09 Mar 2024 16:36:57 -0500

> I've just pushed a large commit to feature/positioned-lambdas, a work
> in progress commit for bug#67455, putting source position information at
> the start of doc strings.  master was merged into it just before the
> commit.

I barely started to look at the code, but regarding the following hunk:

    diff --git a/lisp/emacs-lisp/backquote.el b/lisp/emacs-lisp/backquote.el
    index 6917128d70a..0d4681bc979 100644
    --- a/lisp/emacs-lisp/backquote.el
    +++ b/lisp/emacs-lisp/backquote.el
    @@ -172,6 +172,30 @@ backquote-process
           (backquote-delay-process s (1- level))))
        ((eq (car s) backquote-backquote-symbol)
           (backquote-delay-process s (1+ level)))
    +   ;; Process a (lambda ...) form specially, since otherwise the
    +   ;; lambda symbol would get separated from its introductory (,
    +   ;; preventing this processing from being done elsewhere in macro
    +   ;; expansion.
    +   ((and (eq (car s) 'lambda)
    +         (symbol-with-pos-p (car s))
    +         (listp (car-safe (cdr s))))
    +    (let ((kdr (backquote-process (cdr s) level))
    +          (lambda-pos (symbol-with-pos-pos (car s)))
    +          )
    +      (if (null byte-compile-in-progress)
    +          (setcar s 'lambda))           ; Strip the position.
    +      (cond
    +       ((= (car kdr) 0)
    +        (cons (car kdr)
    +              (list 'quote
    +                    (byte-run-posify-lambda-form
    +                     (cons (car s) (car (cdr (cdr kdr)))) ; Two cdr's to strip 'quote.
    +                     lambda-pos))))
    +       (t
    +        (cons 1
    +              (list 'byte-run-posify-lambda-form
    +                    (list 'cons (list 'quote (car s)) (cdr kdr))
    +                    lambda-pos))))))
        (t
         (let ((rest s)
              item firstlist list lists expression)

- Testing `byte-compile-in-progress` can't be right.  Do you to test
  whether the result of this backquote will be byte-compiled or do you
  really mean to test whether this backquote happens to be executed
  during compilation (which could be because the compiler ends up
  loading code while executing `eval-when-compile` or `require`)?

- My gut tells me that changing backquote can't be right.
  (lambda (f) ..) *can* appear within a backquote without it being an
  actual lambda expression.
  What alternatives have you considered?


        Stefan

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.