Re: [gofrontend-dev] Re: [PATCH 7/9] Gccgo port to s390[x] -- part I

[Ian Taylor <iant at golang dot org>]

On Thu, Oct 30, 2014 at 12:25 AM, Dominik Vogt <vogt@linux.vnet.ibm.com> wrote:
> On Wed, Oct 29, 2014 at 10:16:40AM -0700, Ian Taylor wrote:
>> Thanks.  Part of the problem is that the m68k max alignment is 16
>> bits, but the godump test expects it to be at least 64 bits.  This is
>> BIGGEST_ALIGNMENT in config/m68k/m68k.h.  Another part of the problem
>> seems to be that structs are sometimes aligned to 16 bits although
>> there is no obvious reason for that.  I'm not sure where that is
>> coming from.
>
> Hm, the test cases make assumptions about the Abi (structure
> padding and alignment) that are true on x86, x64_64 and s390[x].
> That may not be the case on other platforms and hence the tests
> fail.  Another candidate for test failures is the effect of
> bitfields (named or anonymous) on structure layout.
>
>> We could disable the test on m68k or make it more accepting.
>
> Since the point of some of the tests is to make sure that the Go
> structure layout matches the C layout, making the tests accept
> deviations seems to be rather pointless.  It's possible to add
> target selectors to all the "scan-file" lines, but that is a lot
> of work and will likely become unmaintainable very soon when more
> platforms need to be added.  Personally I cannot provide fixed
> tests for all the Abis either, so my suggestion is to "xfail" the
> test on all targets except s390[x] and x86_64 and leave it to the
> people who know the other platforms to decide whether the test
> should work there or how the test could be modified to work.
>
> See attached patch.

I don't mind skipping the test on other platforms, but xfail is not
correct.  When an xfail test passes, we get an XPASS error from the
testsuite.  We need dg-skip-if.  I committed this patch.

Ian


2014-10-30  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	* gcc.misc-tests/godump-1.c: Skip -fdump-go-spec tests for all
	platforms except s390[x] and x86_64.

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