r184276 - Debug Info: support for gdwarf-2 gdwarf-3 gdwarf-4

[Eric Christopher]

On Wed, Jun 19, 2013 at 4:01 PM, Manman Ren <mren at apple.com> wrote:
>
> On Jun 19, 2013, at 8:57 AM, Eric Christopher wrote:
>
>> Hi Manman,
>>
>> Few issues with this patch:
>>
>>> Debug Info: support for gdwarf-2 gdwarf-3 gdwarf-4
>>>
>>> These options will add a module flag with name "Dwarf Version".
>>> The behavior flag is currently set to Warning, so when two values disagree,
>>> a warning will be emitted.
>>>
>>
>> I don't think a module flag is the way we want to go about this, I
>> think it should be an attribute on the compile unit created.
>
> Using module flag is from previous email exchanges where you mentioned "a module level attribute".
> I may have misinterpreted what you meant.
>

Probably not, see below :)

> I assume you are now suggesting adding a member in DICompileUnit for Dwarf version.
> I agree that having a dwarf version on each CU gives us finer control as mentioned in your point b).
>

Yeah, Dave mentioned we'd talked about it in the past, but I can't
remember any logic that won me over convincingly...

> I remember you tried to bump the version from 2 to 3 before, so I used 3 as a startup.
> We can definitely bump it further to 4 if 3 is not causing any issue.
>

*nod* We'll need to fix address sizes, etc. here, but it shouldn't
cause more problems than that - outside of old gdbs, but this will fix
that problem :)

-eric