[LLVMdev] [lld] alias atoms and LayoutPass

[Shankar Easwaran]

On 2/12/2015 2:26 PM, Rui Ueyama wrote:
> Looks like there's a bug. It's weird that the existing test didn't catch
> that. I'll probably need to fix the ordinal of alias atoms.
>
> LayoutPass is retired peacefully. I know that code very well, because after
> you added code to that file for follow-on/followed-by relations, I spend so
> much effort improving that functionality while keeping the original
> intention. I refactored it for readability, fixed various bugs, improved
> performance (originally it was even quadratic), and added bunch of
> (overly-designed in hindsight) assertions to verify that too-flexible
> complex data structure is in a well-formed shape. Eventually I had to
> conclude that this was not a good design after all -- it was too
> complicated compared to what it would do. So I cannot agree.
The whole point of LayoutPass was it was reference based previously and 
now its ordinal based. It was more generic previously(though we didnt 
need that complexity).

Shankar Easwaran
> On Thu, Feb 12, 2015 at 10:44 AM, Shankar Easwaran <shankare at codeaurora.org>
> wrote:
>
>> Hi,
>>
>> It looks like the COFF reader creates an Alias atom by adding a
>> kindLayoutAfter reference to the target atom. Now since the kindLayoutAfter
>> passes are moved to machO how does it still work ?
>>
>> Does it work by chance because of ordinals ? I would think moving
>> kindLayoutAfter references and having the LayoutPass would be a better
>> choice.
>>
>> Shankar Easwaran
>>
>> --
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted
>> by the Linux Foundation
>>
>>


-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation