Re: Portability fixes for win32 cross compiling

[Volker Grabsch <vog@notjusthosting.com>]

Ludovic Courtès <ludo@gnu.org> schrieb:
> Volker Grabsch <vog@notjusthosting.com> writes:
> 
> > The "gen-scmconfig" script includes a mix of native and
> > cross headers, which goes horribly wrong when performing
> > win32 cross compiling.
> 
> What happens exactly?

I don't think that the exact error messages are relevant here
(some conflicting definitions of various symbols and types,
 resulting in various compiling errors),

because this is a general thing: You can't expect such a mix
of headers to work properly.

More concretely, when building "gen-scmconfig" with the native
compiler, you can only expect the native headers to be available,
not the cross headers. Well, the cross headers _are_ available,
but only because you add their include paths via "-I", which is
certainly not a sensible thing to do: You force the native compiler
to include headers written to be used by the cross compiler. You
simply can't expect that to work. Don't #include cross headers in
a native build.

> > Is it really necessary to #include
> > the "uniconv.h" from the cross system and to provide corresponding
> > SCM_ICONVEH_* constants?
> 
> The idea is to avoid including libunistring headers in public Guile
> headers, so that the dependency on libunistring isn’t visible from the
> outside.
> 
> Perhaps we could extract the values in some other way, but I’d like to
> make sure I understand the problem before attempting something.

I hope my explainations above help to make the issues more clear.

BTW, you can easily reproduce the issues by installing "Mingw-cross-env"
on your system, if you like.   http://mingw-cross-env.nongnu.org/#tutorial


Greets,
Volker

-- 
Volker Grabsch
---<<(())>>---
Administrator
NotJustHosting GbR