cygport cross-compiling beta2

[Yaakov (Cygwin/X)]

On Thu, 2010-07-29 at 03:53 -0400, Charles Wilson wrote:
> From (patch v3-7/9):
>         The = in func_replace_sysroot_result is the source of
>         forwards-compatibility problems of older Libtools.
>         Maybe --mode=finish could get rid of those.  For platforms
>         such as mingw where both native and cross-compilation makes
>         sense, it would provide an easy way to deploy .la files
>         that are usable without a new libtool.

libtool --mode=finish isn't run when installing with DESTDIR.

> +    Caution: .la files generated with sysroot support will _not_ be
> +    usable in general with older Libtools.

This is a problem, particularly if using sysroot-enabled libs on the
$host, where libtool is almost certain to not be that new.

> > Furthermore, do these patches address the issue that -L$libdir and
> > -Wl,-rpath,$libdir are passed even when $libdir (or $sysroot$libdir) is
> > in $sys_lib_search_path_spec? 
> 
> It doesn't appear so, but that is not a sysroot-specific issue, is it? I
> mean, you still get that behavior now, even for native compilers, right?

I suppose so, but it's particularly a problem with cross-compiling, as I
found out lately.

> However, how does this affect your decision?  If --with-sysroot defaults
> to no, then...nothing changes.  If you choose to use
> --prefix=$sysroot$prefix, it'll work just as well (or as badly) as the
> same arrangement works on other $builds.  (If it defaults to yes, and
> you still want to use $sysroot$prefix, then you could simply add
> --without-sysroot to all configures, right?)

It's a matter of API/ABI: among the various cross-samples I'm working
with, a few will need changes depending on whether we go with --prefix=
$sysroot$prefix or --prefix=$prefix and DESTDIR=$D$sysroot.  Since I'm
working with a pretty small sample, I can only assume that more packages
would be affected down the road.  So if libtool is going to be fixed
*right now*, then we'll go with that, otherwise we'll have to deal with
the consequences of changing sometime later.

> OTOH, if you choose to use --prefix=$prefix and the new sysroot support
> in libtool, that's great (I'd want to go that route) but...it still
> doesn't solve the foo-config problem -- unless you go forward with your
> cross_sysrootize() function in cygport.

I would also prefer to do this as well, as I did in beta1, as this is
AFAICS the ultimate purpose of sysroots and would solve the issues you
raised with cross-compiling libraries for the host.  If libtool does get
fixed, then I don't see foo-config as difficult enough by itself to
warrant not going that route.


Yaakov