[Bug testsuite/80759] gcc.target/x86_64/abi/ms-sysv FAILs

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80759

--- Comment #19 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #18 from Daniel Santos <daniel.santos at pobox dot com> ---
> I intended to respond to your comments from 6 days ago sooner, but better late
> than never!  Again, sorry for the delay

No worries at all: I'm way late here myself ;-)

> (In reply to ro@CeBiTec.Uni-Bielefeld.DE from comment #14)
>> You need to make certain to have the necessary 32-bit libraries and
>> headers.  Apart from that, configure --target=i686-pc-linux-gnu
>> --enable-targets=all should be enough, together with CC='gcc -m32'
>> CXX='g++ -m32'.  I don't pass --enable-multilib, this happens by default.
>
> I think I'll need to figure this part out soon, as I posted earlier about
> strange problems when calling exec.  As it turns out, there are a lot of
> variables in the generated script that aren't being populated,
> ORIGINAL_AS_FOR_TARGET being one of them.  The "exec: --: invalid option"
> problem is occurs because ORIGINAL_AS_FOR_TARGET expands to an empty string and
> the first thing after "exec" is the argument "--32" that is intended for the AS
> program.

I now remembered what you're probably missing: as soon as configure and
the gcc build process are run with --target=<some target> which differs
from the (guessed by config.sub) values for --host and --build, they
conclude that a cross-configuration/-build is running and make their set
of assumptions on how to locate cross-ar/as/ld.  In the case at hand
(and any multilibbed target in general), this is wrong: this is *not* a
cross-build since the host can execute both 32 and 64-bit binaries and
many of those assumptions are wrong.

The way to convince configure of that fact is to run it with

--build=i686-pc-linux-gnu --host=i686-pc-linux-gnu --target=i686-pc-linux-gnu

This way, you'll get a native build and all problems should vanish.

While in theory both /usr/bin/as and /usr/bin/ld should be capable of
performing both 32 and 64-bit assemblies/links, I found it best to
provide an i686-pc-linux-gnu gas and gld with

--with-as=<path to gas> --with-gnu-as --with-ld=<path to ld> --with-gnu-ld

to avoid a couple of corner cases.  You should configure binutils in the
same way, perhaps again with CC='gcc -m32' CXX='g++ -m32'.

I'll comment on the rest later once I find some time.

        Rainer