Re: PKG_CHECK_MODULES on system without pkg-config installed?

[Miles Bader]

Jef Driesen <address@hidden> writes:
> I'm aware of the advantage of using pkg-config. I even supply the *.pc
> files for my own projects. But the point is that if I want to support
> systems that don't have pkg-config installed (like Mac OS X in my
> case), I have to provide a fallback with manual detection anyway. So
> why not skip pkg-config entirely?

I don't even try to fully support systems without pkg-config, I
basically just want a fallback so I can get some sort of build on them,
maybe with some features disabled.

So what I do is use PKG_CHECK_MODULES for normally pkg-config'd
packages.  It's very concise and easy to use (one line per library,
normally).  On systems without pkg-config, this will just fail as if the
package wasn't installed at all.

For a few of the most critical libraries, I use both PKG_CHECK_MODULES
(it yields better results when available, is almost trivial, and the
support infrastructure is present for other packages anyway), _and_ more
traditional probing code as a backup (but see below why it's annoying).

> And I could simply replace the pkg-config based check with something like:

Even that -- rather verbose -- code often isn't enough, because install
locations can vary between systems, in a manner that varies from package
to package.  In such cases, you can either require the user to specify
the location with a configure option (and I want to avoid require user
input if at all possible), or you can add a loop to guess various common
configurations (which make the configure code somewhat more complex as
well as being more likely to yield incorrect results).

[Note, all of this results from trying to compile on systems where
something didn't work!]

-Miles

-- 
Faith, n. Belief without evidence in what is told by one who speaks without
knowledge, of things without parallel.