Eliminating automatic provides on private libs

[Panu Matilainen]

On 04/29/2012 06:25 PM, Panu Matilainen wrote:
> On 04/29/2012 06:13 PM, Panu Matilainen wrote:
>> On 04/27/2012 07:36 PM, Toshio Kuratomi wrote:
>>> On Fri, Apr 27, 2012 at 11:13:47AM +0300, Panu Matilainen wrote:
>>>>
>>>> I'm going to add a switch to allow packages to control the behavior
>>>> anyway. Whether rpm upstream defaults to the traditional behavior for
>>>> compatibility reasons or not is another question, but Fedora is
>>>> obviously free to override that. Given the packaging guideline
>>>> mandate to eliminate private soname provides from packages it seems
>>>> like a no-brainer to disable faked sonames by default, and require
>>>> the handful of special cases to work around it (adding
>>>> enable-switches to specs) instead of adding disable-switches to
>>>> possibly hundreds of packages to cater for the special cases needs.
>>>>
>>>> Thoughts? This would obviously only change in rawhide.
>>>>
>>>> Oh and of course eliminating the faked soname provides does not
>>>> eliminate all unwanted provides, eg libtool adds a soname even when
>>>> -module is used. But ... you need to start someplace.
>>>>
>>> Will the toggle to turn it on and off work for those libtool generated
>>> modules (as long as there's not public libraries in the same
>>> package)? Is
>>> it possible to turn this on and off per subpackage or is that along the
>>> lines of asking for pretty pink ponies with wings?
>>
>> For now, I'm only talking about a switch that stops faking a soname
>> provide when an ELF DSO does not provide one, nothing more. Also that
>> switch is going to be a global macro to avoid spec syntax compatibility
>> issues, at least for now.
>>
>> As for the other issues like libtool generated modules, the question is:
>> why does libtool insist on creating a soname for them, and could we get
>> libtool changed not to do that?
>>
>> Also it might be possible to come up with heuristics to detect (some of)
>> such modules based on the data in elf headers.
>
> Actually... one painfully simple and obvious heuristic is the DSO
> basename: if it doesn't start with "lib", it's almost certainly not a
> regular library.

...but then there's ld-*.so. Which of course is not your average regular 
library either, but requiring spec tweaks to get the necessary provides 
into place for such a fundamental piece of the system doesn't seem right 
either.

One possibility that looks like it should weed out nearly all the 
private libs (plugins etc) whether created with libtool or not, and 
still handle ld-linux.so correctly by default:

Only create soname provides if the DSO specificies specifies a SONAME, 
and the soname either starts with "lib" or is versioned.

It's just that it's getting a bit thick in the heuristics department. 
Sigh... it would all be sooooo simple if presence of SONAME could be 
used as a mostly reliable indicator for the DSO's public/private status :(

	- Panu -