Re: [PATCH 2/4] scripts: add reqs python library

[Michal Marek <mmarek@suse.com>]

Dne 15.6.2016 v 18:02 Luis R. Rodriguez napsal(a):
> On Wed, Jun 15, 2016 at 09:50:11AM +0200, Michal Marek wrote:
>> On 2016-06-15 00:10, Luis R. Rodriguez wrote:
>>> +        weight = (int(rel_specs['VERSION'])    << 32) + \
>>> +                 (int(rel_specs['PATCHLEVEL']) << 16) + \
>>> +                 (sublevel   		       << 8 ) + \
>>> +                 (extra * 60) + (relmod * 2)
>>
>> This is going to silently break as soon as we have a version number with
>> e.g. a time stamp embedded. 
> 
> Well this is adhering to a linux_version_cmp type, surely we can adjust
> it with alternatives. It just happens that with the common stuff this
> suffices.
> 
> Do you have a specific string in mind I can use to test against?

You can have a look at the git history of scripts/ld-version.sh.


>> And there is actually no need to convert the
>> version string to an integer. You can convert them to arrays of
>> components and compare the components one by one.
> 
> You can, however weight is used to as a generic formula to determine
> in one shot if you have a release >= than what is required. Its inspired
> by how KERNEL_VERSION() is used:
> 
> #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))

Yes, the kernel interface provides comparisons using the preprocessor
arithmetic, so it needs to convert the version strings to integers. But
you are providing methods to compare the versions and what happens in
these methods stays in these methods :).

Michal