Re: sparse attribute packed on structures

[Jacob Keller <jacob.e.keller@intel.com>]

On 12/16/2020 3:30 PM, Luc Van Oostenryck wrote:
> On Tue, Dec 15, 2020 at 03:15:48PM -0800, Jacob Keller wrote:
>>
>> I did find one bug, in your step (3), you have a check against
>> info->packed on symbol.c:162 in lay_out_struct, but nothing ever set the
>> packed value. I think you just need to initialized info->packed from
>> sym_packed at the top of examine_struct_union_type, i.e.
> 
> A yes, I see, thank you. I think it was on purpose that it wasn't
> yet enabled (things are it fuzzy because the code is ~2 year old)
> and as I said it's unfinished.
> 
> But, with your change, does it handles 'packed' more or less
> correctly?
> 
> -- Luc
> 

Yes. Obviously we're limited in that we no longer check for
out-of-bounds accesses on bitfields, but it at least produces the
correct sizes for structures, and avoids the warnings that I was running
into.

Overall, I think the changes in that branch are solid, and look correct
to me.

I'm not sure what all the limitations are of having it produce incorrect
load/store operations that don't work with the packed bitfields.. but at
least for the code I was checking, it seems to be correct now.

Thanks,
Jake