Re: On elisp running native

[Eli Zaretskii]

> From: Andrea Corallo <address@hidden>
> Cc: address@hidden, address@hidden
> Date: Sat, 28 Dec 2019 08:56:17 +0000
> 
> Eli Zaretskii <address@hidden> writes:
> 
> > I'm not sure I understood you, but dlopen, dlsym etc. (or their moral
> > equivalents) are readily available on Windows; see src/dynlib.c.  So
> > that cannot be the reason why libgccjit is not available on Windows.
> 
> Sure, but libgccjit AFAIU just calls directly dlopen
> (gcc/gcc/jit/jit-playback.c:2650).

That's OK.  One of the MinGW flavors actually provides these functions
directly; for the other it should be easy to write them so that
libgccjit can call them.

> I've just found this interesting old thread:
> 
> https://gcc.gnu.org/ml/jit/2015-q3/msg00124.html

Thanks.  Not sure what to make from that, especially since AFAIK the
Windows code is PIC by default.  The problems they are talking about
are very easy to solve, but somehow no one has yet solved them.  Which
might mean there's more to it than meets the eye.  (However, I'm
talking out of sheer ignorance, so perhaps you should ask on the GCC
list whether there are any fundamental problems with providing
libgccjit on Windows.)

Maybe you should explain in more detail how will the compiled code be
loaded into Emacs.  Is each .el file compiled into a separate shared
library?  If so, when the shared library is loaded, what entry point
is called, and how does Emacs know which entry point to call when?

Also, compiling needs gas and ld, right?  IOW, people who'd like to
use this feature for Lisp that is not part of Emacs will have to have
GCC and GNU Binutils installed, something that AFAIU is not guaranteed
even on GNU/Linux these days.