On Fri, Dec 6, 2013 at 10:11 AM, Eric Botcazou <ebotca...@adacore.com> wrote:
>> Here's the Correct Fix(tm). We may or may not decide to go for it because
>> of concerns about ABI changes; in the latter case, any kludge that we'll
>> put in place instead must be restricted to the cases caught by this patch.
>>
>>
>> * stor-layout.c (compute_record_mode): Return BLKmode for a trailing
>> array with size 0 or 1.
>
> Revised version without the one-by-one error...
It's not fully fixing the issue as _all_ aggregates that may be
accessed beyond their
declarations size are broken.
I'd say we should simply stop giving aggregates a mode besides BLKmode. What
can possibly break with that ...
struct { char c[4]; }
has SImode, we accept all trailing arrays as possibly extending beyond the
struct declaration.
Alternatively all structs with aggregate members should not have a
mode != BLKmode.
Previously you said it doesn't have ABI impacts and I doubt it has optimization
impacts.
Richard.
> --
> Eric Botcazou
