Improve pkg-config support

[mnhauke]

The pkg-config file should list all the requirements needed for the library.

See:
https://people.freedesktop.org/~dbn/pkg-config-guide.html#faq

Here's an example from another project:
https://github.com/realnc/SDL_audiolib/blob/master/CMakeLists.txt
https://github.com/realnc/SDL_audiolib/blob/master/SDL_audiolib.pc.in

The same applies to your other libraries (ocania,..).

[babelouest]

Thanks for the pointer

I'm not sure I understand the difference between Requires and Requires.private though (and the other *.private values as well).

In your example, both values are the same, and the pkg-config documentation says:

* Requires: A list of packages required by this package. The versions of these packages may be specified using the comparison operators =, <, >, <= or >=.
* Requires.private: A list of private packages required by this package but not exposed to applications. The version specific rules from the Requires field also apply here.

Does it mean in ulfius case that the values would be something like?

Requires: libmicrohttpd, jansson, gnutls, libc6, libcurl, yder, orcania
Requires.private: libmicrohttpd, gnutls, libc6, libcurl

Since Jansson, Yder and Orcania functionalities are exposed to applications that use ulfius.

[babelouest]

If I understand correctly the documentation, the master branches of Orcania, Yder, Ulfius and Hoel should now have correct values for pkg-config.