Re: [boost] Finding the correct library to link (feature request for pkg-config support)

From: Domenico Andreoli (cavokz_at_[hidden])
Date: 2007-07-30 02:45:37

On Mon, Jul 30, 2007 at 10:09:43AM +0400, Vladimir Prus wrote:
> Roger Leigh wrote:
> > 
> > 2) pkg-config also provides other extra information in addition to the
> >    library name for linking:
> > 
> >    a) The CFLAGS needed to build.  This might be as simple as a
> >       -Iincludedir, but could also include -Ddef and threading options,
> >       such as -pthread if using multithreaded libraries.
> > 
> >    b) LDFLAGS including the library directory -Ldir option, needed to
> >       find the correct instance of the library and the -llibrary
> >       option.
> > 
> >    c) Libs.private is a list of dependent libraries needed to link.
> >       When linking dynamically, at least on ELF systems, dependent
> >       libraries are seen as NEEDED entries in the dynamic section of
> >       the symbol table.  But, static libraries carry no dependency
> >       information; you have to know, and this provides a mechanism to
> >       link statically by allowing discovery of the depdendencies.
> > 
> >       Maybe I need to link to libicu, maybe I don't.  This can be
> >       tailored to the specific build of Boost, so there's no
> >       ambiguity.  i.e. the pkg-config file is generated with plaform-,
> >       compiler- and build-specific information embedded in it as
> >       needed.
> > 
> >     d) Requires and Conflicts can specify versioned dependencies for
> >     other libraries also using pkg-config.  Currently, I don't think
> >     you would need this, but libraries based on Boost libraries can
> >     then Require boost pkg-config modules.
> 
> 
> Those (a)-(c) points above are the most clear explanations of pkgconfig
> benefits I've heard on this list, and it appears reasonable to add 
> pkgconfig support to Boost.Build. At the same time, I think we *first*
> should try to change the build process so that properly named libraries
> are created on Linux, so that things work even without pkgconfig. 

let me stress the fact that sources using linux names would not be
generally portable to other platforms. such a solution would not be
much different from directly using decorated library names, only a
little more easy to use.

thanks,
domenico

-----[ Domenico Andreoli, aka cavok
 --[ http://www.dandreoli.com/gpgkey.asc
   ---[ 3A0F 2F80 F79C 678A 8936  4FEE 0677 9033 A20E BC50