On Fri, Mar 15, 2019 at 12:06:13PM +0100, Andrea Bolognani wrote:
On Fri, 2019-03-15 at 11:27 +0100, Erik Skultety wrote:
On Thu, Mar 14, 2019 at 05:52:17PM +0000, Daniel P. Berrangé wrote:
Although the toolchain binaries for 32-bit x86 are using the ABI i686-linux-gnu, the library install directory is strangely named with the different i386-linux-gnu.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> ---
so the patch looks good to me, so I can give you my: Reviewed-by: Erik Skultety <eskultet@redhat.com>
Agreed:
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
However, I wasn't able to find anything explaining this to help me understand, apart from: https://wiki.debian.org/Multiarch/Tuples
but there's essentially no mention of i686.
Basically if you look at eg.
https://packages.debian.org/sid/amd64/gcc-aarch64-linux-gnu/filelist https://packages.debian.org/sid/arm64/libvirt0/filelist
you'll see that the name of the cross-compiler contains the ABI name, and so does the library path:
/usr/bin/aarch64-linux-gnu-gcc /usr/lib/aarch64-linux-gnu/libvirt.so.0
This is consistent for all Debian architectures *except* i386, where as seen in
https://packages.debian.org/sid/amd64/gcc-i686-linux-gnu/filelist https://packages.debian.org/sid/i386/libvirt0/filelist
the name of the cross-compiler still contains the ABI name, but the library path uses a slightly different triplet instead:
/usr/bin/i686-linux-gnu-gcc /usr/lib/i386-linux-gnu/libvirt.so.0
This is the reason why we need to special-case this architecture when generating a cross-compilation environment.
Thinking some more, I expect what happened is that the Debian 32-bit x86 arch did indeed generate code compatible with i386 and thus this library path got set. These days no one cares about true i386 compat, so the compiler toolchain is built to generate i686 compatible instructions, hence the compiler got the different name, but the library directory path remainined for back compat. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|