Re: [Contrib PATCH] Add scripts to convert GCC repo from SVN to Git

["Martin Liška" <mliska@suse.cz>]

On 5/19/19 10:06 PM, Marek Polacek wrote:
> On Sun, May 19, 2019 at 01:00:45PM -0700, Andrew Pinski wrote:
>> On Sun, May 19, 2019 at 12:54 PM Segher Boessenkool
>> <segher@kernel.crashing.org> wrote:
>>>
>>> On Sun, May 19, 2019 at 03:21:01PM -0400, Marek Polacek wrote:
>>>> On Sun, May 19, 2019 at 03:11:08AM -0500, Segher Boessenkool wrote:
>>>>> On Sun, May 19, 2019 at 09:35:45AM +0200, Martin Liška wrote:
>>>>>> Do we really need a commit integer numbers after the transition? I know
>>>>>> we're used to it.
>>>>>> But git commit hash provides that same.
>>>>>
>>>>> Revision numbers are nice short text strings, and from a revision number
>>>>> you can see approximately when it happened, and from two revision numbers
>>>>> on the same branch you can trivially tell which one is older.  Those are
>>>>> nice features.  But we can live without it, IMO.
>>>>
>>>> Since I do many bisections a day, losing this capability would be Very Bad.
>>>> Without it, there's no range, and without a range, there's nothing to _bisect_.
>>>>
>>>> I bisect by hand, so if I have cc1plus.250000 (good) and cc1plus.260000 (bad),
>>>> I know the commit I'm looking for is within that range, and I can easily split
>>>> the range, and it's at most log n steps.  Whereas if we had e.g. cc1plus.de28b0
>>>> and cc1plus.a9bd4d, I couldn't do it anymore.
>>>
>>> Git can bisect automatically just fine, there is no upside to doing things
>>> manually.  In git there are various handy ways of referring to commits; you
>>> can say  master@{3 days ago}  for example, or zut@{31}  to get the 31st
>>> commit back on branch "zut", etc.  See "man gitrevisions".
>>
>> Well one thing is if you have prebuilt cc1/cc1plus.  So it is not
>> really doing a manual bisect per-say but rather it is doing a manual
>> bisect using prebuilt binaries and knowing which one comes before
>> which one.
> 
> Exactly, we have many TBs of prebuilt binaries.

I combine both together, feel free to use my script:
https://github.com/marxin/script-misc/blob/master/gcc-bisect.py

It uses git repository for navigation, information about branches, tag releases
and so on. And then I have a folder with pre-built binaries which are identified
by commit hash. That works all fine.

Martin

> 
>> One way is store the binaries based on the date that commit happened
>> instead.  This is a bit more complex but still doable.
> 
> Yeah, I guess we'll have to do something like that, then.  :/
> 
> --
> Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA
>