Re: [RFA/sparc64] internal-error printing return value (Ada array)

Mark Kettenis
2006-11-11T17:47:53Z

> The type in question is a TYPE_CODE_ARRAY. It seems that this case
> is not handled yet by the function that extracts the return value:
>
> sparc64-tdep.c:sparc64_extract_return_value
>
> I am not sure yet whether this case is specific to Ada or if we can
> reproduce the same with C, I will double-check.

C doesn't really have arrays.

> I think the best fix for this is to update sparc64_structure_or_union_p
> to accept arrays of 32 bytes or less. The name would become slightly
> misleading for its actual implementation, and I wouldn't mind changing
> it if felt necessary.
>
> I don't know if the same issue applies to 32bit GDB or not. I tried,
> but "fin" doesn't stop at the function return, so I never get the
> returned value printed by GDB. I'll have a look at this another time.
>
> I also noticed that the same problem happens for arrays larger than
> 32bytes. In fact, this is not specific to arrays, but to structures
> as well. Support for structures larger than 32 bytes seems to be
> missing. I can add that too, but let's make this another patch.
>
> 2006-11-10 Joel Brobecker <brobecker@adacore.com>
>
> * sparc64-tdep.c (sparc64_structure_or_union_p): Accept array
> types if the type length is 32 bytes or less.
>
> Fixes the two FAILs above, no regression.
> OK to apply?

I don't think this is the right fix; the length check almost cetainly is.

To decide what is the right fix, we need to investigate this a bit further.
I suspect that Ada arrays arereally treated as structures where all members
have the same type. So the first question I have is whether these indeed
have "fields". You should also check how small arrays are passed as
arguments to a function. Here the magic length will be 16 bytes instead
of 32 bytes.

Mark