On Wed, 5 Dec 2007 00:01:22 +0100 Raphael Hertzog <[EMAIL PROTECTED]> wrote:
> On Tue, 04 Dec 2007, Neil Williams wrote:
> > +my @shlibdeps=();
> > +# ARCH for some awkward builds
> > +my $crossprefix = Dpkg::Arch::debarch_to_gnutriplet($ENV{ARCH}) if
> > ($ENV{ARCH});
>
> What's the role of $ARCH ? And why shall we consider that we're
> crossbuilding only because this variable is set ?
Not cross building - building a cross compiler.
gcc relies on $ARCH when preparing libgcc1-$arch-cross and other
toolchain libraries.
The actual call in gcc is:
ARCH=arm MAKEFLAGS="CC=something" dh_shlibdeps -plibgcc1-arm-cross
e.g.
> cd /opt/emdebian/emchain/gcc-4.2-4.2.2
> GCC_TARGET=arm DEB_CROSS=yes debian/rules control
> GCC_TARGET=arm DEB_CROSS=yes dpkg-buildpackage -b -uc -us -rfakeroot
>
> build completes as normal with the patch
>
> Testing from gcc-4.2-4.2.2 directory:
> ARCH=arm MAKEFLAGS="CC=something" dh_shlibdeps -plibgcc1-arm-cross
>
> no errors.
>
> Without the patch, I get:
> dpkg-shlibdeps: failure: couldn't find library libc.so.6 needed by
> debian/libgcc1-arm-cross/usr/arm-linux-gnu/lib/libgcc_s.so.1 (its RPATH
> is '').
> Note: libraries are not searched in other binary packages that do not
> have any shlibs file.
> To help dpkg-shlibdeps find private libraries, you might need to set
> LD_LIBRARY_PATH.
> dh_shlibdeps: command returned error code 512
...
> > +# host for normal cross builds.
> > +$crossprefix = $ENV{DEB_HOST_GNU_TYPE}
> > + if (($ENV{DEB_HOST_GNU_TYPE}) and ($ENV{DEB_HOST_GNU_TYPE} ne
> > $ENV{DEB_BUILD_GNU_TYPE}));
>
> I think you should use the functions contained in Dpkg::Arch instead of
> relying only the environment variables here...
Those variables are only defined in a cross build, not when building a
cross compiler or a toolchain.
We cannot use 'dpkg-architecture -a..' when building a cross compiler,
therefore we only have the environment variables.
> use Dpkg::Arch qw(get_host_arch get_build_arch debarch_to_gnutriplet);
> [...]
> if (get_host_arch() ne get_build_arch()) {
> $crossprefix = debarch_to_gnutriplet(get_host_arch());
> }
>
> > +# target when building a cross compiler
> > +$crossprefix = $ENV{DEB_TARGET_GNU_TYPE}
> > + if (($ENV{DEB_TARGET_GNU_TYPE}) and ($ENV{DEB_TARGET_GNU_TYPE} ne
> > $ENV{DEB_BUILD_GNU_TYPE}));
>
> Why would we need a special treatment of libs when creating a
> cross-compiler? The cross-compiler runs on the build arch but is not linked
> against any lib of the target arch so it doesn't need to scan the
> directories of the target arch.
The cross compiler needs to build cross libraries that *are* called
when preparing the cross compiler itself.
--
Neil Williams
=============
http://www.data-freedom.org/
http://www.nosoftwarepatents.com/
http://www.linux.codehelp.co.uk/
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