[CMake] Hint on usage of ExternalProject_Add

[Luigi Calori]

Luigi Calori wrote:

Getting no feedback, try to be shorter....

Is possible with ExternalProject  skip download+patch if only configure 
or build fails?
I'm working with 2.8.0,MSVC9
I tried without success: the target does not try to rebuild if I change 
CMAKE_ARGS
Is it intended?
Is 2.8.1 RC1 worth a try for that?

Any real example really appreciated.

Thanks in advance

Luigi

> Hi everybody, first sorry for the long intro,
>
> <SKIP>
>
> I' m trying to build up a project that assembles different components, 
> all open source and portable.
> The main component is OpenSceneGraph that heavily relies on FindXXX to 
> do configure time inspection and conditionally build plug ins.
> I am trying to build up an application (browser plug in) that bundles 
> my code,  OSG, and other plugins and their deps.
> I have to pack it as a package that has as few external deps as 
> possible, so i would like either to build static or to provide most of 
> the dll/so I would also provide a transparent and easy way to build 
> the package from original upstream sources of components: sou would 
> like to restrict at minimum inclusion of externally build binary 
> components.
> For these reasons I have started to look at recently added  
> ExternalProject_Add macro
> As the deps are quite few and change in versions, way of building, etc 
> etc, I was thinking to organize them in separate folders, specific for 
> dep and version, placing each ExternalProject_Add into an individual 
> CMakeLists.txt, alongside with Patch files and so on.
> All the installation step of ExternalProject_Add should put stuff in a 
> common place that should be searched first by FindXXX or configure
> Any comment or hint for the whole task really welcome, I' ve also used 
> and borrowed code  from cmakeports project on google code, that seem 
> on hold now and somehow superseded by ExternalProject approach
> Now some specific questions
>
> <SKIP>
>
> some examples of ExternalProject_Add usage
>
> Hints on deal with download-unpack-patch to separate the source 
> assembling phase to the build phase,
> (currently, visual studio projects issues re-download,unpack and patch 
> when switching from Release to Debug)
>
>
>
>