[committed][gdb/testsuite] Update psym-external-decl.exp for gcc-10/clang

[Tom de Vries]

On 6/19/20 4:00 PM, Gary Benson wrote:
> Tom de Vries wrote:
>> On 6/18/20 6:10 PM, Gary Benson wrote:
>>> Tom de Vries wrote:
>>>> On 6/17/20 2:24 PM, Gary Benson wrote:
>>>>> Tom de Vries wrote:
>>>>>> diff --git a/gdb/testsuite/gdb.base/psym-external-decl.exp b/gdb/testsuite/gdb.base/psym-external-decl.exp
>>>>>> index bbcc2745755..d0388d5655e 100644
>>>>>> --- a/gdb/testsuite/gdb.base/psym-external-decl.exp
>>>>>> +++ b/gdb/testsuite/gdb.base/psym-external-decl.exp
> [nsip]
>>>>> Tom, I'd like this testcase to not fail silently.  Is the
>>>>> functionality under test something that isn't ever expected to
>>>>> work with clang, or is this a test that should pass with clang
>>>>> (but it currently doesn't, for whatever reason)?
>>>>
>>>> I'm not sure.  The test can pass with clang, provided it generates the
>>>> required debug info.  It currently doesn't.  Why that is the case, I
>>>> have no idea.
>>>
>>> I think that means the test should work but it doesn't.  Would you
>>> object if I push a patch removing the test-skipping logic?  It will
>>> mean an extra FAIL when tested using clang
>>
>> I don't think having a fail for a compiler bug/missing-feature is a
>> good idea.
>>
>> If this is due to a bug/missing-feature in clang, then we need to:
>> - xfail the test,
>> - file the PR in clang, and
>> - reference the PR at the xfail.
> 
> Is this a bug/missing feature in clang though?
> How sure are you GDB isn't at fault?

Clang emits less debug info than GCC.  Whether that's a bug, a missing
feature or an explicit unsupported feature in clang, I don't known.

I known that gdb isn't at fault.  It can't do anything without the
missing debug info.  The test was specifically written to use that debug
info.

Thanks,
- Tom