Re: no .pc file

[Richard Purdie]

On Fri, 2012-10-26 at 13:27 -0500, Bob Friesenhahn wrote:
> On Fri, 26 Oct 2012, Yaroslav Bulatov wrote:
> 
> > Oops my bad....that was a bad paste from some auto-generated code.
> >
> > This is basically a modified version of .pc file I get when building
> > zlib. Not sure how useful this is because you need to update "prefix"
> > in this file manually each time you rebuild libtool. Ideally the .pc
> > file would be generated automatically by configure/make
> 
> If it is not clear, package config files are operating system and/or 
> operating system distribution and/or operating system release version 
> specific.  One reason for this is that each operating system 
> distribution uses its own names for pkg-config package definitions. 
> Using zlib as an example is not useful since zlib does not depend on 
> any other packages.  Most packages depend on other packages and so 
> there is an OS-distribution (or even site-specific) list of packages 
> that this package depends on.
> 
> While many packages do produce sample pkg-config files (based on 
> guess-work or assumption of a partiticular OS distribuiton), it is 
> common practice for the default offering to be modified by the OS 
> package distribution maintainer because the OS uses a different name 
> for a similar thing.
> 
> Being intended for portable software, libtool does not concern itself 
> with a hand-edited/non-portable framework like pkg-config.

As I understand it, the .pc files use their own namespace so once a
given piece of software has chosen its naming, other things can depend
on it using that name space and it doesn't matter about the OS
distribution or OS version used. This is a clear incentive to maintain
the .pc file with the software so that there is one common naming used,
at least in pkg-config space. There is no connection to the package
management namespace which is totally separate.

This assumes that people use some kind of common sense when choosing
namespace but other than that it seems to work well.

As one of the people looking after the Yocto Project (which includes an
build system targeted at embedded devices), I have to say I see less
problems with pkg-config than with libtool and I'm once again being
asked to remove all .la files as a policy decision due to them causing
more problems than they seem to solve in a cross environment :(. I'm
running out of arguments against this, not least as I couldn't get any
response to the libtool sysroot problems I reported a while back.

Cheers,

Richard