Re: Libtool and Pkg-Config

[Havoc Pennington]

Alexandre Oliva <address@hidden> writes:
> 
> You wouldn't.  This is totally out of the scope of libtool.  Libtool
> is about linking with libraries, not compiling source files so that
> they can be linked with them.  Not that it couldn't be extended so as
> to record user-directed flags at the time of creation of a library.
> But what should it do when a library is linked with other libraries?
> Should it merge the recorded flags with those of the dependence
> libraries, or record just what the user specified?

pkg-config merges the flags. This appears to always be the right thing
to do, in the examples I've seen.

Note that pkg-config merges at query-time, not at install time. That
is, the .pc file contains cflags that are specific to that library;
but 'pkg-config --cflags gtk+' also outputs cflags for all
dependencies of gtk+.

The rationale for putting this in libtool would be that the .la file
becomes a repository for info needed to use a library, not just info
needed to link. Having just the one file is much simpler for users,
and if pkg-config just has this one --cflags feature people will be
bitter about having to download and install a separate package.

Obviously to replace pkg-config you have to support non-libtool
app builds, so you would need the query mode equivalent anyhow.

Havoc