[cmake-developers] Policy for INTERFACE_LINK_LIBRARIES

[Stephen Kelly]

Brad King wrote:

>> Brad King wrote:
>>> How can we ever stop exporting the old interface when it comes from the
>>> link implementation?
> 
> Now even projects that have never touched LINK_INTERFACE_LIBRARIES will
> have to be fixed to manually set it to a copy of the link implementation
> in order to remain compatible with older CMake versions once they set the
> policy to NEW.  I'm not currently sure whether this is okay.

I've added another patch to my clone to solve this problem:

Export link implementation as old link interface if it does not contain 
generator expressions.
    
That way,
    
 target_link_libraries(foo bar)
    
will export the old and new link interfaces, and
    
 target_link_libraries(foo $<1:bar>)
    
will export only the new one, which is appropriate anyway because only that 
can handle the generator expressions.

Thanks,

Steve.