Re: [gentoo-dev] RFC: GLEP 64: Standardize contents of VDB and establish and API for exporting this information.

[Anthony G. Basile]

On 09/01/14 02:24, Fabian Groffen wrote:
> On 30-08-2014 16:02:51 -0400, Anthony G. Basile wrote:
>> ...  During that meeting, the council focused on NEEDED.ELF.2 which is
>> recorded by portage, but not paludis. Linkage information is generated
>> during package builds, is expensive to recalculate and is needed by
>> other packages like revdep-pax for PaX marking ELF objects.
> Portage is able to calculate dependency information for
> @preserved-rebuild based on the information stored in multiple files,
> (NEEDED,) NEEDED.ELF.2, NEEDED.MACHO.3, NEEDED.XCOFF, NEEDED.PECOFF, etc.
> For this purpose, it would be helpful if a generalised interface would
> be exported, instead of the raw files (and their storage format
> version).  Portage, for instance, internally has a function that queries
> for consumers of a specific library (file), abstracting away parts of
> the shared library format internals, that otherwise would have to be
> implemented by all tools.
>
> Fabian
>
>

Here are some packages that raw-read VDB, other than portage itself:

* sys-apps/elfix (python)
* app-portage/gentoolkit (python)
* app-portage/portage-utils (C)
* app-portage/eix (C++)

There are probably more, but I am familiar with their internals. 
Generally, these packages use VDB information for 1) lists of files and 
2) linking information.  Again, caching this information (because it is 
expensive to re-calculate) and exporting it via a general interface is 
useful.

Fabian thanks for pointing out the other NEEDED.* files.  I wondered how 
portage did this for alternative exe formats.

-- 
Anthony G. Basile, Ph.D.
Gentoo Linux Developer [Hardened]
E-Mail    : blueness@g.o
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