Re: configure's dependency on pkg-config

[Jan Djärv]

12 nov 2011 kl. 23:33 skrev Stephen Berman:

> On Sat, 12 Nov 2011 15:13:49 +0100 Jan Djärv <address@hidden> wrote:
> 
>> Hi.
>> 
>> 11 nov 2011 kl. 20:25 skrev Stephen Berman:
> [...]
>>> Is there a better way to override configure's dependency on pkg-config
>>> for libraries such as libxml2, so that it would suffice to pass the
>>> standard variable CPPFLAGS, LDFLAGS and LIBS?  Or if there isn't, should
>>> there be?
>> 
>> I would assume libxml2 installs its .pc-file in /usr/lib/pkgconfig (or
>> similar) when you install it, so all the info is there.  So why not just
>> install pkg-config?  It is a very small package.
> 
> No doubt pkg-config is convenient and of course I could install it; but
> my experience shows that even though it's not necessary, you can't avoid
> it by setting the recommended variables at configure time.  So this
> seems to be at least a doc bug in INSTALL, which should explicitly say
> that pkg-config is required in order for Emacs to use certain libraries
> and also list all of these libraries.  The alternative would be to patch
> configure (or rather configure.in) to allow setting the standard
> configure time variables to override using pkg-config.  This seems
> better to me in principle (though it might be judged not to be worth the
> effort); are there any platforms Emacs runs on that cannot use
> pkg-config but on which Emacs could use libxml2 etc.?

I don't know why you are opposed to installing pkg-config, but it is not Emacs 
choice.  libxml2 has made pkg-config the way for users of that library to find 
out compiler and linker flags as well as dependencies on other libraries.  So 
of course Emacs uses that.  Who are we to argue about the validity of that 
descision?  Ditto for Gtk, dbus, and others.

If you wan't another way to use libxml2 without using pkg-config, you should 
take that up with libxml2-developers.  If they make another way to compile with 
their library, Emacs can use that.  But I don't understand why Emacs should 
take the trouble to make sure Emacs can use a library WITHOUT using the 
official, sanctioned way of using that library.

        Jan D.