CMAKE script retro-compatibility

Hi,

I didn't post anything for a while, but in since few days, I found several topic for which I would like to write something (It's like a reminder for me ...)

I worked on product that we build on several different linux platform (Centos/Ubuntu/ etc ...). We use cmake and someone updated a script in a way it couldn't work anymore with older version of cmake (prior to 2.8.3). As I implemented a work-around, I wanted to share it because it was an annoying issue.

In cmake v2.8.3, a new "Useful variable" was introduced CMAKE_CURRENT_LIST_DIR.
If you had to use a cmake script in which that variable is used, cmake will not complain, it will just consider the variable as empty.

The work-around use the other function of cmake to initialize that value and let the rest of your script unchanged.

if("${CMAKE_CURRENT_LIST_DIR}" STREQUAL "")
message(STATUS "work-around to get the current folder for cmake version prior to 2.8.3")
get_filename_component(CMAKE_CURRENT_LIST_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
endif()

It's quit simple, first I test if the value is empty, and if it's true I use get_filename_component cmake command to extract the current folder path from the CMAKE_CURRENT_LIST_FILE cmake variable.