Package: emacs;
Reported by: chuntaro <chuntaro <at> sakura-games.jp>
Date: Tue, 5 Mar 2019 15:30:02 UTC
Severity: normal
Done: Stefan Monnier <monnier <at> iro.umontreal.ca>
Bug is archived. No further changes may be made.
View this message in rfc822 format
From: Stefan Monnier <monnier <at> IRO.UMontreal.CA> To: Eli Zaretskii <eliz <at> gnu.org> Cc: chuntaro <at> sakura-games.jp, Pip Cet <pipcet <at> gmail.com>, 34757 <at> debbugs.gnu.org Subject: bug#34757: Invalid bytecode from byte compiler Date: Fri, 15 Mar 2019 10:08:48 -0400
>> diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
>> index 0b8f8824b4c..4e54e08ce14 100644
>> --- a/lisp/emacs-lisp/bytecomp.el
>> +++ b/lisp/emacs-lisp/bytecomp.el
>> @@ -3025,6 +3025,7 @@ byte-compile-out-toplevel
>> (or (null (cdr rest))
>> (and (memq output-type '(file progn t))
>> (cdr (cdr rest))
>> + (eql (length body) (cdr (car rest)))
>> (eq (car (nth 1 rest)) 'byte-discard)
>> (progn (setq rest (cdr rest)) t))))
>> (setq maycall nil) ; Only allow one real function call.
>
> Stefan, any comments?
Looks good to me, thanks.
I'm personally running with the following patch instead, which is much
more risky and hasn't been sufficiently tested yet.
Stefan
diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index f46cab2c17..573b0489d4 100644
*** a/lisp/emacs-lisp/bytecomp.el
--- b/lisp/emacs-lisp/bytecomp.el
***************
*** 2990,3059 ****
(setq byte-compile-output
(byte-optimize-lapcode byte-compile-output)))
! ;; Decompile trivial functions:
! ;; only constants and variables, or a single funcall except in lambdas.
! ;; Except for Lisp_Compiled objects, forms like (foo "hi")
! ;; are still quicker than (byte-code "..." [foo "hi"] 2).
! ;; Note that even (quote foo) must be parsed just as any subr by the
! ;; interpreter, so quote should be compiled into byte-code in some contexts.
! ;; What to leave uncompiled:
! ;; lambda -> never. we used to leave it uncompiled if the body was
! ;; a single atom, but that causes confusion if the docstring
! ;; uses the (file . pos) syntax. Besides, now that we have
! ;; the Lisp_Compiled type, the compiled form is faster.
! ;; eval -> atom, quote or (function atom atom atom)
! ;; progn -> as <<same-as-eval>> or (progn <<same-as-eval>> atom)
! ;; file -> as progn, but takes both quotes and atoms, and longer forms.
! (let (rest
! (maycall (not (eq output-type 'lambda))) ; t if we may make a funcall.
! tmp body)
! (cond
! ;; #### This should be split out into byte-compile-nontrivial-function-p.
! ((or (eq output-type 'lambda)
! (nthcdr (if (eq output-type 'file) 50 8) byte-compile-output)
! (assq 'TAG byte-compile-output) ; Not necessary, but speeds up a bit.
! (not (setq tmp (assq 'byte-return byte-compile-output)))
! (progn
! (setq rest (nreverse
! (cdr (memq tmp (reverse byte-compile-output)))))
! (while
! (cond
! ((memq (car (car rest)) '(byte-varref byte-constant))
! (setq tmp (car (cdr (car rest))))
! (if (if (eq (car (car rest)) 'byte-constant)
! (or (consp tmp)
! (and (symbolp tmp)
! (not (macroexp--const-symbol-p tmp)))))
! (if maycall
! (setq body (cons (list 'quote tmp) body)))
! (setq body (cons tmp body))))
! ((and maycall
! ;; Allow a funcall if at most one atom follows it.
! (null (nthcdr 3 rest))
! (setq tmp (get (car (car rest)) 'byte-opcode-invert))
! (or (null (cdr rest))
! (and (memq output-type '(file progn t))
! (cdr (cdr rest))
! (eq (car (nth 1 rest)) 'byte-discard)
! (progn (setq rest (cdr rest)) t))))
! (setq maycall nil) ; Only allow one real function call.
! (setq body (nreverse body))
! (setq body (list
! (if (and (eq tmp 'funcall)
! (eq (car-safe (car body)) 'quote)
! (symbolp (nth 1 (car body))))
! (cons (nth 1 (car body)) (cdr body))
! (cons tmp body))))
! (or (eq output-type 'file)
! (not (delq nil (mapcar 'consp (cdr (car body))))))))
! (setq rest (cdr rest)))
! rest))
! (let ((byte-compile-vector (byte-compile-constants-vector)))
! (list 'byte-code (byte-compile-lapcode byte-compile-output)
! byte-compile-vector byte-compile-maxdepth)))
! ;; it's a trivial function
! ((cdr body) (cons 'progn (nreverse body)))
! ((car body)))))
;; Given BODY, compile it and return a new body.
(defun byte-compile-top-level-body (body &optional for-effect)
--- 2993,3013 ----
(setq byte-compile-output
(byte-optimize-lapcode byte-compile-output)))
! (cond
! ((and (not (eq output-type 'lambda)) ;;The caller really wants (byte-code ...)
! (null (cddr byte-compile-output))
! (eq (car (nth 0 byte-compile-output)) 'byte-constant)
! (eq (car (nth 1 byte-compile-output)) 'byte-return))
! ;; Special case for trivial code returning a function.
! ;; This is so that when compiling #'(lambda ...) we return
! ;; a #[...] byte-code object instead of a (byte-code "...")
! ;; expression that returns this object. It's not indispensable,
! ;; but it's cleaner.
! (macroexp-quote (cadr (nth 0 byte-compile-output))))
! (t
! (let ((byte-compile-vector (byte-compile-constants-vector)))
! (list 'byte-code (byte-compile-lapcode byte-compile-output)
! byte-compile-vector byte-compile-maxdepth)))))
;; Given BODY, compile it and return a new body.
(defun byte-compile-top-level-body (body &optional for-effect)
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