Speeding up Flymake in emacs-lisp-mode

[João Távora]

Hi,

If you've tried M-x flymake-mode in emacs-lisp sources, you'll have
noticed there's a byte-compilation backend.  This relies on launching an
external 'emacs -Q' on an idle timer which does little but byte-compile
the a file with the buffer's contents and collect messages, which are
then used to annotate the buffer.

It works very well on Mac and Linux, but on windows is unusably slow
(presumably) because of a ~1 sec process-launching overhead.

It'd probably be better if only one process was launched and asked
(perhaps using server.el) to compile the files.  But this would have a
major disadvantage over the current approach, which is that the elisp
runtime is tainted by previous compilations.  The external process
approach doesn't have this disadvantage, since every emacs is clean when
launched.

Which brings me to my question: is there a way to re-flash the current
emacs's image with a brand new one, or to erase any side-effects of
previous byte-compilations? The only pitfall would be that I would need
server.el's bits to escape this reflashing otherwise I would be locked
out.

Thanks,
João