RE: Byte-compiled elisp libraries on different platforms

[Drew Adams]

> > I don't agree about the last part. I have come across 
> > things that do not work in Emacs 23 if byte-compiled
> > with Emacs 22 (and vice versa).
> 
> I was talking only about 22 -> 23, not the other way around.

Me too (that's what I said). And I mentioned both directions - I've seen
problems in both directions.

> And of course you can have code that does fail, in subtle or not so
> subtle ways. If it does not satisfy the expectations of 23.X
> (functions with different parameter profiles, macros whose semantics
> has changed, whatever), for example. The only real way to have 100%
> compatibility is compiling the .el files with the Emacs release you're
> going to use them.

Agreed.

> That said, most of the time .elc files generated with 22.X work fine
> with 23.X Emacs.

Most, yes, probably. The byte-compiler changes probably affect only a minority
of code in incompatible ways. But it's enough. ;-)

> > In general, I believe, Emacs has always been 
> > platform-independent wrt byte-compiled code,
> 
> Yes. But as stated above, whether a .elc file from one Emacs works in
> another Emacs is not (just) about byte-code.

Agreed. But if the uncompiled code works on two different platforms, then so
should the byte-compiled code (compiled with the same release #).

> Of course byte-code must be compatible, or you're liable to crash Emacs.

Yup.