[CMake] target_link_libraries: prefer static to dynamic

[Michael Wild]

On 28. Dec, 2009, at 12:40 , Pau Garcia i Quiles wrote:

>> That sounds doable to me. However, you'd need a mechanism to express the same preference when calling find_package and then have find_package communicate that to find_library. Not sure how fine-grained
>> the control should be for FindXXX.cmake modules that find more than one library (or call another FindYYY.cmake internally).
> 
> The very same syntax should work for find_package: find_package( XXX
> VARIANT static shared ). Inside FindXXX.cmake you'd do something like:
> 
> IF( XXX_FIND_VARIANTS )
>  FIND_LIBRARY( xxx VARIANTS ${XXX_FIND_VARIANTS} )
> ELSE( XXX_FIND_VARIANTS )
>  FIND_LIBRARY( xxx )
> ENDIF( XXX_FIND_VARIANTS )
> 
> Or, even better, one of these three solutions could be adopted to
> avoid the 'if':
> 
> * Make XXX_FIND_VARIANTS contain "VARIANTS static shared ..." instead
> of just "static shared ...". That way, in FindXXX.cmake you'd do:
>    FIND_LIBRARY( xxx ${XXX_FIND_VARIANTS} )
>  If find_package was called without the VARIANTS parameter, that'd
> resolve to FIND_LIBRARY( xxx )
> 
> * Make CMake automagically construct XXX_FIND_VARIANTS with the
> default values ("shared static ..." or whatever Kitware considers
> sensible). I. e. inside find_package, XXX_FIND_VARIANTS would always
> exist. If it was overriden by the FindXXX.cmake author, it'd have the
> overriden value. If it wasn't overriden by the FindXXX.cmake author,
> it'd have the default value. Again, in FindXXX.cmake you'd only do:
>    FIND_LIBRARY( xxx ${XXX_FIND_VARIANTS} )
> 
> * Make find_library always consider XXX_FIND_VARIANTS (a different
> name, such as xxx_FIND_LIBRARY_VARIANTS, would probably be better to
> avoid confusion with modules' variables)  if it exists, without the
> need for a new parameter to find_library/find_package. Pros: every
> CMake module gains support for finding static, shared, frameworks,
> etc. Cons: very intrusive.

I'd go with option 2. I'm still unsure whether it would be desirable to have more fine grained control, e.g. if FindXXX has multiple find_library calls, or calls itself find_package internally.

And, of course, somebody would have to implement it... What about compatibility with CMAKE_FIND_FRAMEWORK?

Michael