[yocto] inc files in recipes

[Tian, Kevin]

>From: Frans Meulenbroeks [mailto:fransmeulenbroeks at gmail.com]
>Sent: Friday, November 19, 2010 5:43 PM
>
>>
>>>
>>>Here the inc file could be merged into the bb file.
>>>This has the advantage of having only a single file, so it is slightly
>>>easier if you want to read or maintain the recipe.
>>
>> One advantage of not doing so is to retrieve change history in git easily.
>> Version change on .bb is a rename which in git is simply a remove and
>> create, while with .inc you can easily track history. This also reduces the
>> commit size.
>
>If I am correct git mv does preserve history although the name change
>makes it a little bit more difficult to track them.

I'm not sure how that works consistently. Sometimes the rename is kept
while most times it doesn't happen to me. :-(

>
>Wrt commit size: I agree that the commit size is bigger.
>If you want to minimize this you should maximize what goes into the inc.
>Personally when it comes to choosing between readability, cleanness
>etc and commit size, I go for the former.

I'm neutral here actually. :-) But I agree with you that we should document
such guideline on the wiki after it's finalized.

>>
>>>
>>>For recipes with multiple versions (e.g. tar) it might be useful to
>>>have inc files. It is really a tradeoff between easy access/reading
>>>and maintainability here.
>>
>> There's one case we actually suggest not using .inc for multiple versions:
>> both GPLv2 and GPLv3 exist for one package. That way we can avoid potential
>> contamination as much as possible.
>
>If you want to avoid contamination as much as possible I would suggest
>creating two different folders. They are two different beasts that you
>want to maintain separately.
>
>The same also holds if you want to keep two versions because they are
>e.g. functionwise very different.
>Sometimes this is already done (at least in OE, there we have e.g
>libsigc++-1.2 and libsigc++-2.0 and apache and apache2 directories,
>also sometimes there are differently named recipes (different PN) in
>the same folder, e.g. bluez and bluez4)
>

Perhaps that's the better approach.

Thanks
Kevin