Re: [testsuite patch] Skip py-unwind.exp on x86_64 -m32

[Yao Qi <qiyaoltc at gmail dot com>]

On Mon, Jul 18, 2016 at 12:33 PM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> On Mon, 18 Jul 2016 12:04:27 +0200, Yao Qi wrote:
>> This problem is slightly different from "how to run testsuite in cross-arch
>> mode", IMO.
>> py-unwind.py defines a unwinder, in an arch-specific way.  It has nothing
>> wrong.
>> However, py-unwind.py should be more portable, which means, it should
>> define unwdiner for each arch it supports, and py-unwind.exp or py-unwind.py
>> chooses the right python unwinder according to the arch.  IOW, we need to
>> define a python unwinder for i386, and use it when arch is i386.
>
> There will always exist at least one unsupported arch for an arch-specific
> testcase.  I do not think it makes sense to say that very every testcase in
> the testsuite must support very every arch supported by GDB.
>
> So we can say that py-unwind.exp just does not support arch i386.
> I do not find that wrong.

It is still better to get one test case cover one more arch.

>
> Wrong is that it should not FAIL on unsupported arch, it should skip the
> testcase on unsupported arch.
>

IMO, it is wrong that py-unwind.py creates an x86_64 specific unwinder.
py-unwind.py should create a unwinder instance according to the arch if the
arch is supported.  On i386, or other archs, like arm, mips, py-unwind.py
can error, and py-unwind.exp knows unwinder is not created successfully,
and mark the test unsupported.  If people want to extend py-unwind.py for
their archs, they can modify py-unwind.py to create an unwinder instance
for their own arch.

> The problem here is that py-unwind.exp thinks that it runs on arch x86_64 but
> it runs on arch i386.
>
> Even if py-unwind.exp did support i386 it would still FAIL because it would
> run the testcase for %rbp/%rsp/%rip.

py-unwind.exp does nothing on arch specific thing, so py-unwind.exp shouldn't
be aware of the arch difference, but py-unwind.py should.

-- 
Yao (齐尧)