[ofa-general] [PATCH] add pkgconfig support to ibverbs library

[Steven Dake]

On Mon, 2009-07-20 at 18:06 -0600, Jason Gunthorpe wrote:
> On Mon, Jul 20, 2009 at 04:12:34PM -0700, Steven Dake wrote:
> > The librdmacm maintainer would have to decide if it is worth it for him
> > to use pkgconfig functionality in his configure scripts.  For other
> > downstream projects that link against librdmacm or libibverbs that
> > follow the upstream adoption model of autotools (always use latest
> > autotools, older versions may have bugs), it has many benefits.
> > 
> > Example:
> > ./configure --includedir=/tmp/abc
> > make install
> 
> > How does the downstream adopting application know where the include
> > files are located in /tmp/abc?
> 
> I don't see how that would work even with pkg-config and the
> PKG_CHECK_MODULES macro. The dumb configure misfeature is that all the
> options like --includedir that chain off --prefix are the INSTALLATION
> paths for the thing you are configuring, not the SEARCH paths needed
> to build.
> 
> pkg-config's m4 seems to respect that and doesn't add those options to
> the search path for .pc's
> 
> > Not all distros put the include files in the same location.  There
> > are two alternatives for downstream projects.
> 
> No.. distros have to put this stuff in the system search path, under
> the prefix we've picked so #include <infiniband/verbs.h> works ok, and
> -libverbs works ok. Anything else is madness, I don't know any distro
> that would do otherwise - it is contrary to the entire point of a
> distro...
> 
> The only case to worry about is when someone installs this stuff
> outside the system search path, ie your /tmp/abc/ or some-such, in
> which case, I think you are just trading one obscure environment
> option (CPPFLAGS/LDFLAGS) for another (PKG_CONFIG_LIBDIR).
> 
> > As a downstream adoptor, solving the "what are the flags" in a scalable
> > easy to use fashion is the main advantage I get with pkgconfig with
> > minimal upstream rdmacm and ibverbs disruption.
> 
> Some of the gnome software pkg-config was made for have interesting,
> non-simple requirements that pkg-config handles - but I don't see
> anything in the OFA packages that matches that stuff. These are all
> ment to be system libraries that don't have special user compilation
> requirements or flags when installed in the system search path. Any
> distro that does otherwise is broken..
> 
> Anyhow, sounds like adding the .pc files to the builds isn't a big
> deal and some minor cases do work better. But I guess I don't see a
> benefit from using PKG_CHECK_MODULES, and you've outlined enough
> reasons to avoid it..
> 
> BTW, libibcm, libibumad and libibmad should also all get .pc files for
> consistency. :)
> 

have git locations for libibumad and libibmad?

Regards
-steve

> Jason