[llvm-dev] Status of docs/BitCodeFormat.rst?

[Ismail Badawi (ibadawi) via llvm-dev]

I’ve opened https://reviews.llvm.org/D25623 to start bringing this up to date. Would appreciate someone taking the time to review.

Thanks,
Ismail

> On Oct 13, 2016, at 2:10 PM, Mehdi Amini <mehdi.amini at apple.com> wrote:
> 
> It is more than that: the ID was *freed* and that’s why it has been reused for something else.
> We only support bitcode from version 3.0 and above.
> There is really no point keeping in the documentation construct from 2.9 and before that we can’t read anymore today.
> 
> Hope this makes sense.
> 
> — 
> Mehdi
> 
>> On Oct 13, 2016, at 11:09 AM, Ismail Badawi (ibadawi) <ibadawi at cisco.com> wrote:
>> 
>> I think it just changed formats which prompted a change in ID -- the code now uses TYPE_BLOCK_ID_NEW (= 17). I haven’t looked deeply to see how different it is.
>> 
>> Ismail
>> 
>>> On Oct 13, 2016, at 2:02 PM, Mehdi Amini <mehdi.amini at apple.com> wrote:
>>> 
>>> 
>>>> On Oct 13, 2016, at 10:24 AM, Ismail Badawi (ibadawi) via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>>> 
>>>> Hi folks,
>>>> 
>>>> A while back I noticed some outdated information in docs/BitCodeFormat.rst about how parameter attributes were encoded — it describes an old encoding that was changed in 3.3 with the introduction of attribute groups. I opened a bug about this (https://llvm.org/bugs/show_bug.cgi?id=28941) and started trying to write a patch, but along the way ran into more and more issues (e.g. new things not documented, things that were removed or changed formats).
>>>> 
>>>> So I’m wondering whether there is an interest in keeping this document up to date. I see that there are some commits to this file in 2016 so it’s not totally abandoned, but at the same time there is information that has been outdated for 5+ years.
>>>> 
>>>> Assuming there is an interest, I’m also wondering whether (or how) to approach fixing this incrementally. For example, in trying to document the new paramattr format, I noticed that the type format is also outdated, and there is a conflict in block ids (i.e. the old TYPE_BLOCK format which is documented used blockid=10, but blockid=10 is now used for PARAMATTR_GROUP_BLOCK),
>>> 
>>> For this particular example, it should just be removed I think. If I read correctly the history the TYPE_BLOCK was a 2.9 thing.
>>> 
>>> — 
>>> Mehdi
>>> 
>>> 
>>>> so that fixing the paramattr docs on their own might introduce inconsistencies. Would it be better to try & bring the whole document up to date at once, or would it be fine to do it incrementally & possibly introduce some strangeness in the intermediate steps?
>>>> 
>>>> Thanks,
>>>> Ismail
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>>> 
>> 
>