[CMake] Build only what you need in third party libs

[Michael Wild]

On 22. Dec, 2009, at 16:22 , David Cole wrote:
<snip>
>> 
>> That's exactly my point: if the dependent project is the calling project
>> (i.e. the one that calls ExternalProject_Add), you have to use error-prone
>> ADD_LIBRARY(<name> <type> IMPORTED) calls with according invocations of
>> SET_TARGET_PROPERTIES(<name> PROPERTIES IMPORTED_LOCATION <filepath>). In
>> the case of Boost this is probably very difficult to get right, because from
>> what I hear, the library names change almost randomly with operating system,
>> compilation flags and what not. So what ExternalProject.cmake is missing, is
>> a mechanism of "pulling" the targets of the external project into the
>> calling project.
>> 
>> 
> So first build boost and everything with a simple "build my prerequisites"
> project that builds/installs all your prereqs in a nice, reasonable fashion.
> 
> Then your project can just find/include/import everything as your accustomed
> to without any fuss.

That is a workable solution for "tech-savvy" users, I'm not so sure the average admin will appreciate it (remembering the heated and quite ridiculous discussions on KDE not providing a configure script anymore...)

> There will never be an easy way to pull external projects directly into a
> calling project because the external things are not even guaranteed to be on
> disk yet at configure time of said calling project.


Yeah, kind of a chicken-egg problem...

Michael