Re: Libtool and Pkg-Config

[Eric Lemings]

"Gary V. Vaughan" wrote:

> Yes, I have been thinking about this.  Although I was planning on writing a
> macro for autoconf-2.50 which would help generate the foo-config scripts.  I
> think your idea is a much better approach, and I'll add it to the TODO list
> presently.  Thanks.

You mean I actually came up with a good idea?  Wow.  ;)

> > Since most packages that use pkg-config also use libtool, I think this
> > would be a good way to reduce maintainer and developer dependencies.
>
> Most definitely.  Do you think there is any chance of rustling up some
> support for sending in a patch to get the ball rolling?

Well since two of the primary authors involved have already chimed in with
support, I'd say the ball is poised at least to start rolling.  But as Havoc
said, someone has to do the work.  I guess since I proposed the idea, that means
me.  I'm always willing to try but I'm really not familliar with the internals
of either tool.

What I do know though is that a few (if not several) packages are already using
pkg-config.  So if libtool is extended with that functionality, it should be
compatible with the current behavior of pkg-config.  This means that libtool
would first look for the .pc files and use them if found; otherwise, it would
use data of the same sort from its own files.  Havoc can add further details but
I think the primary data that pkg-config currently maintains/supplies includes
the following:

    * prefix
    * exec_prefix
    * includedir
    * libdir

    * name
    * version
    * description
    * dependencies
    * cflags
    * ldflags
    * libs

The variables relating to include directories may be considered out of libtool's
scope when considered in a purely runtime environment but they are essential for
development too.

Here's the complete set of pkg-config options for ease of reference:

Usage: pkg-config [OPTION...]
  --version                             output version of pkg-config
  --modversion                          output version for package
  --atleast-pkgconfig-version=VERSION   require given version of pkg-config
  --libs                                output all linker flags
  --libs-only-l                         output -l flags
  --libs-only-L                         output -L flags
  --cflags                              output all pre-processor and compiler
                                        flags
  --cflags-only-I                       output -I flags
  --variable=VARIABLENAME               get the value of a variable
  --exists                              return 0 if the module(s) exist
  --atleast-version=VERSION             return 0 if the module is at least
                                        version VERSION
  --exact-version=VERSION               return 0 if the module is at exactly
                                        version VERSION
  --max-version=VERSION                 return 0 if the module is at no newer
                                        than version VERSION
  --list-all                            list all known packages

Help options
  -?, --help                            Show this help message
  --usage                               Display brief usage message

Eric.