Respect LIB_SUFFIX and LIB_INSTALL_DIR

[Nikoli]

Ability to choose lib dir is required for making Gentoo package. Examples: http://quickgit.kde.org/?p=libechonest.git&a=blob&h=ac3c77b30febe9aa2f4127ecf5b51bf6974a6a81&hb=f32ec00185b3fbb4c493dc7cc511b0ad96b7911f&f=CMakeLists.txt#l69 https://bitbucket.org/acoustid/chromaprint/src/dd51f8e571227fc4bb8f09e382e4258ccea46757/CMakeLists.txt?at=master#cl-36

[Fat-Zer]

Here is an example patch for such options: https://gist.github.com/Fat-Zer/5845277 . btw: It would be nice if we could get moduledir from vdpau's pkg-config (like pkg-config vdpau --variable=moduledir), although FindPkgConfig haven't got such features.

[i-rinat]

fixed.

[i-rinat]

Here is an example patch for such options:

Thanks.

[Fat-Zer]

Sorry for my tedious exhortation, but you supposed to use CACHE variables for such stuff.

Firstly, this three lines:

if(NOT DEFINED LIB_INSTALL_DIR)
    set(LIB_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX})
endif(NOT DEFINED LIB_INSTALL_DIR)

are equivalent to one:

set(LIB_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX} CACHE PATH "<comment>" )

Moreover, the second variant is preferred cause the variable will be prompted in configuration utilities like cmake -I. Because of that it would be nice to give LIB_SUFFIX it's own declaration as well.

[i-rinat]

you supposed to use CACHE variables for such stuff.

Sounds reasonable. Applied.

[Fat-Zer]

LIB_INSTALL_DIR supposed to point to «lib» dir itself, not vdpau. AFAIK it's not the rule carved in stone but a lot of packages do so and some build systems [e.g. in gentoo] count on it.

[i-rinat]

LIB_INSTALL_DIR supposed to point to «lib» dir itself, not vdpau.

IMO, if build system sets custom LIB_INSTALL_DIR, that is the directory where it expects libraries to go. It's much more confusing to figure out that installer decided to append another directory (vdpau) to it. There is no sense to add another configurable variable either. If one have chosen to change LIB_INSTALL_DIR, he may add such suffix himself if needed.