bug#64642: 29.0.92; Native compiler doesn't compile dynamically bound functions.

[Eli Zaretskii]

> Date: Sat, 15 Jul 2023 09:38:13 +0000
> From: Alan Mackenzie <acm@muc.de>
> 
> Hello, Emacs.
> 
> In the Emacs 29 pretest version (or the master version):
> (i) emacs -Q
> (ii) C-x b foo.el <RET>
> (iii) M-x emacs-lisp-mode <RET>
> Don't set lexical-binding in this buffer.
> (iv) Enter a function called foo:
>     (defun foo () "foo doc string"
>       (lambda (bar) "lambda doc string" (car bar)))
> (v) With point after the function, evaluate it with C-x C-e.
> 
> (vi) M-: (native-compile 'foo)
> This signals an error, native-compiler-error-dyn-func.  This is a bug.
> 
> #########################################################################
> 
> The immediate cause of the bug is in the version of
> comp-spill-lap-function which processes named functions (comp.el).
> Unlike the other version of the cl-defmethod (which processes lambda
> functions), there is no code for dynamic functions here.
> 
> If the intention is not to process dynamic functions, this should be
> indicated by an error message rather than a signal.  Personally, I feel
> that dynamic functions ought to be handled in Emacs-29.
> 
> Fixing this bug should be relatively straightforward, since it should
> only involve copying and adapting the corresponding code in the lambda
> version of comp-spill-lap-function.

Adding Andrea.

It is unlikely that this will be fixed in Emacs 29, unless the fix is
so simple that will surprise me.