Small packaging improvements

[akien-mga]

About commit bf0312c, I assumed that undefined variables in CMake were already interpreted as an empty string, but that might be worth checking.
To make sure LIB_SUFFIX is empty when undefined, you might add something like:

IF(NOT DEFINED LIB_SUFFIX)
    SET(LIB_SUFFIX "")
ENDIF(NOT DEFINED LIB_SUFFIX)

[akien-mga]

BTW those changes would also be relevant for the pre-C++11 branch.

[cdunn2001]

I'm afraid I don't fully understand this change, having little experience using cmake for static/dynamic libraries as variant builds. In general, shared libs go into the same 'lib' directory as static archives. Does this change affect only the build, or the installation too? I mean, if someone wants to install the shared libs into /usr/local/lib, will that still be possible?

[akien-mga]

The purpose is to install both static and shared libs in $(CMAKE_INSTALL_PREFIX)/lib$(LIB_SUFFIX).
I did not change the output directories for the build, only the ones for system wide installation.

On Debian-based distros, you will usually put static/shared libraries in /usr/local/lib (or /usr/lib for official packages), while on RPM-based distros the 64bit libraries should go to /usr/local/lib64, hence the need for a LIB_SUFFIX variable that RPM packagers will set to "64".

If LIB_SUFFIX is not defined, nothing will change compared to what you currently use.

[akien-mga]

I rebased my pull request to add two small modifications:

• The LIB_SUFFIX variable is now set to an empty string as a default value, and it will be cached, i.e. it will appear as a configurable variable in cmake-gui for example. It can also be overridden by the user thanks to the CACHE parameter.
• Added a mention to issue Please use standard CMake variable to configure static vs. shared builds #51 in 27639ce. (Note that the solution mentioned in this issue might be better than mine, that's why I qualified mine as a "workaround". It doesn't hurt though).

[cdunn2001]

Oh! I thought LIB_SUFFIX was for dynamic versus static, but it's for 64-bit of course! Thanks.

[akien-mga]

You're welcome. Do you want me to make a similar pull request for the pre-C++11 branch, or will you handle that?

[cdunn2001]

We're only doing bug-fixes on that branch, unless you think this is really important.

[akien-mga]

It's not primordial, I already patched it locally to update Mageia's jsoncpp package.

[cdunn2001]

Ok, if you can validate it for us, then we might as well include it on that branch too.

[akien-mga]

I can confirm that it works fine on that branch too, it just needs manual merging since the pkgconfig file is slightly different there. Do you want me to prepare a pull request against the pre-C++11 branch?

[cdunn2001]

Yes, go ahead. If you want, rebase this branch and you can re-use this pull-request, I think.