[ was: Re: [PATCH] gdb/testsuite: Fix typos in infcall-nested-structs.c ]

On 11-10-2019 14:19, Tom de Vries wrote:
> On 10-10-2019 23:07, Tom de Vries wrote:
>> On 10-10-2019 22:26, Tom de Vries wrote:
>>> On 10-10-2019 20:30, Tom de Vries wrote:
>>>> On 10-10-2019 19:24, Andreas Arnez wrote:
>>>>> On Thu, Oct 10 2019, Tom de Vries wrote:
>>>>>
>>>>>> I see these new failures on x86_64-linux:
>>>>>> ...
>>>>>> FAIL: gdb.base/infcall-nested-structs.exp: l=c++: types-tc-tf: p/d
>>>>>> check_arg_struct_02_01 (ref_val_struct_02_01)
>>>>>> FAIL: gdb.base/infcall-nested-structs.exp: l=c++: types-ts-tf: p/d
>>>>>> check_arg_struct_02_01 (ref_val_struct_02_01)
>>>>>> FAIL: gdb.base/infcall-nested-structs.exp: l=c++: types-ti-tf: p/d
>>>>>> check_arg_struct_02_01 (ref_val_struct_02_01)
>>>>>> ...
>>>>>
>>>>> Maybe the test case caught a real bug then, right?  Or do you see a
>>>>> problem with the test case?
>>>>
>>>> I think it's a real bug.
>>>>
>>>> I've minimized the types-ti-tf FAIL to:
>>>> ...
>>>> $ cat test.c
>>>> typedef int ti;
>>>> typedef float tf;
>>>> struct struct_02_01
>>>> {
>>>>   struct { } es1;
>>>>   struct {
>>>>     struct {
>>>>       ti a;
>>>>       tf b;
>>>>     } s1;
>>>>   } s2;
>>>> };
>>>>
>>>> struct struct_02_01 ref_val_struct_02_01 = {
>>>>   {},
>>>>   {
>>>>     {
>>>>       'a',
>>>>       'b'
>>>>     }
>>>>   }
>>>> };
>>>>
>>>> int cmp_struct_02_01 (struct struct_02_01 a, struct struct_02_01 b)
>>>> { return a.s2.s1.a == b.s2.s1.a && a.s2.s1.b == b.s2.s1.b; }
>>>>
>>>> int
>>>> check_arg_struct_02_01 (struct struct_02_01 arg) {
>>>>   return cmp_struct_02_01 (arg, ref_val_struct_02_01);
>>>> }
>>>>
>>>> int
>>>> main (void)
>>>> {
>>>>   return check_arg_struct_02_01 (ref_val_struct_02_01);
>>>> }
>>>> $ g++ test.c -g
>>>> $ ./a.out; echo $?
>>>> 1
>>>> $ gdb a.out -batch -ex start -ex "p check_arg_struct_02_01
>>>> (ref_val_struct_02_01)"
>>>> Temporary breakpoint 1 at 0x400563: file test.c, line 35.
>>>>
>>>> Temporary breakpoint 1, main () at test.c:35
>>>> 35        return check_arg_struct_02_01 (ref_val_struct_02_01);
>>>> $1 = 0
>>>> ...
>>>>
>>>
>>> The discrepancy is that the code generated by gcc passes the struct in
>>> registers %rdi and %xmm0, but amd64_push_arguments classifies the struct as:
>>> ...
>>> (gdb) p theclass
>>> $57 = {AMD64_INTEGER, AMD64_INTEGER}
>>> ...
>>> and therefore passes it in %rdi and %rsi.
>>>
>>
>> I've simplified the test-case a bit further, and filed as:
>> https://sourceware.org/bugzilla/show_bug.cgi?id=25096.
>>
> 
> I've submitted a fix for PR24104 (
> https://sourceware.org/ml/gdb-patches/2019-10/msg00293.html ) which
> marks these 3 FAILs as KFAILs.
> 
> Thanks,
> - Tom
> 

And here's a follow-up patch that fixes PR25096.

OK for trunk?

Thanks,
- Tom