Github/emacs
2
0
Fork 1
mirror of git://git.sv.gnu.org/emacs.git synced 2026-06-14 12:31:25 +00:00
Code Issues Projects Releases Packages Wiki Activity

* lisp/emacs-lisp/cl-macs.el (cl--labels-convert): Fix bug#65017

Browse source 
This fixes what I consider to be the core of the bug, by handling
`cl--labels-convert-cache` more carefully (i.e. being more careful how
we look up its value and by flushing it ASAP).
This commit is contained in:
Stefan Monnier 2023-08-11 23:14:05 -04:00
parent 1da4fca064
commit be3cae9f55
1 changed files with 13 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
lisp/emacs-lisp/cl-macs.el
View file

@ -2037,7 +2037,17 @@ a `let' form, except that the list of symbols can be computed at run-time."
;; *after* handling `function', but we want to stop macroexpansion from
;; being applied infinitely, so we use a cache to return the exact `form'
;; being expanded even though we don't receive it.
((eq f (car cl--labels-convert-cache)) (cdr cl--labels-convert-cache))
;; In Common Lisp, we'd use the `&whole' arg instead (see
;; "Macro Lambda Lists" in the CLHS).
((let ((symbols-with-pos-enabled nil)) ;Don't rewrite #'<X@5> => #'<X@3>
;; FIXME: The above `let' is incorrectly optimized away (bug#65017).
(eq f (car cl--labels-convert-cache)))
;; This value should be `eq' to the `&whole' form.
;; If this is not the case, we have a bug.
(prog1 (cdr cl--labels-convert-cache)
;; Drop it, so it can't accidentally interfere with some
;; unrelated subsequent use of `function' with the same symbol.
(setq cl--labels-convert-cache nil)))
(t
(let* ((found (assq f macroexpand-all-environment))
(replacement (and found
@ -2045,6 +2055,8 @@ a `let' form, except that the list of symbols can be computed at run-time."
(funcall (cdr found) cl--labels-magic)))))
(if (and replacement (eq cl--labels-magic (car replacement)))
(nth 1 replacement)
;; FIXME: Here, we'd like to return the `&whole' form, but since ELisp
;; doesn't have that, we approximate it via `cl--labels-convert-cache'.
(let ((res `(function ,f)))
(setq cl--labels-convert-cache (cons f res))
res))))))