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

["Mark Kettenis" <mark.kettenis@xs4all.nl>]

>  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