[OE-core] Multilib SDK, compiler issues

[Mark Hatle]

When you generate a multilib SDK, i.e. adding this to conf/local.conf:

MACHINE = "qemux86-64"
require conf/multilib.conf
MULTILIBS = "multilib:lib32"
DEFAULTTUNE_virtclass-multilib-lib32 = "x86"

And then build an SDK using 'bitbake meta-toolchain', you end up with and SDK 
that is only partially functional.

Using a small test program
/tmp/t.c:

int main()
{
         return 0;
}

source ./environment-setup-core2-64-poky-linux
$CC /tmp/t.c -o /tmp/t

This works as expected.

However, if you change to the multilib:

source environment-setup-x86-pokymllib32-linux

You get a page of errors trying to link.  The key thing is that a number of 
necessary libraries and linker object files were not installed.  This is fairly 
easy to fix, using the manual settings added to the local.conf file:

TOOLCHAIN_DEPENDS          = "packagegroup-core-standalone-sdk-target 
packagegroup-core-standalone-sdk-target-dbg"
TOOLCHAIN_MULTILIB_DEPENDS = "${@' '.join([variant + '-' + pkg for variant in 
(d.getVar("MULTILIB_VARIANTS", True) or "").split() for pkg in 
(d.getVar("TOOLCHAIN_DEPENDS", True) or "").split()])}"
TOOLCHAIN_TARGET_TASK      = "${TOOLCHAIN_DEPENDS} ${TOOLCHAIN_MULTILIB_DEPENDS}"

(perhaps that or something similar needs to go into meta-toolchain?)

But that doesn't resolve the problem.. the toolchain itself is not configured 
properly.

Once you've done that you still can't link the alternative library toolchain. 
The search-dirs are configured incorrectly:

$ $CC --print-search-dirs

install: 
/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/
programs: 
=/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../libexec/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/:/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../libexec/i586-pokymllib32-linux/gcc/:/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/../../../../../i586-pokymllib32-linux/bin/i586-pokymllib32-linux/4.9.0/:/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/../../../../../i586-pokymllib32-linux/bin/
libraries: 
=/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/:/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/:/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/../../../../../i586-pokymllib32-linux/lib/i586-pokymllib32-linux/4.9.0/:/usr/local/sdk/sysroots/x86_64-pokysdk-linux/usr/bin/i586-pokymllib32-linux/../../lib/i586-pokymllib32-linux/gcc/i586-pokymllib32-linux/4.9.0/../../../../../i586-pokymllib32-linux/lib/:/usr/local/sdk/sysroots/core2-64-poky-linux/lib64/i586-pokymllib32-linux/4.9.0/:/usr/local/sdk/sysroots/core2-64-poky-linux/lib64/:/usr/local/sdk/sysroots/core2-64-poky-linux/usr/lib64/i586-pokymllib32-linux/4.9.0/:/usr/local/sdk/sysroots/core2-64-poky-linux/usr/lib64/

It's looking in the /lib64 and /usr/lib64 directories of the sysroot for some 
reason.  The most I've tracked it down to at this point is that for some reason 
the value 'target_base_libdir' is being set to '/lib64' within the 
cross-canadian.bbclass -- but I can't figure out why that is occurring. 
'bitbake -e' shows that it should be '/lib', so I suspect there is an issue with 
overrides or something and multilib configurations.

Any help would be appreciated.. I'm stumped on this.

--Mark