[cmake-developers] INTERFACE targets (Was: Generator expressisons in target properties)

[Brad King]

On 11/06/2012 01:32 PM, Brad King wrote:
> On 11/06/2012 12:00 PM, Stephen Kelly wrote:
>>  add_library(iface INTERFACE)
>>  set_property(TARGET iface PROPERTY INTERFACE_LINK_LIBRARIES foo bar)
>>  target_link_libraries(test_exe directdep1 iface directdep2)
>>
>> It is not really equivalent to this:
>>
>>  target_link_libraries(test_exe directdep1 foo bar directdep2)
>
> interfaces should be flattened and replaced with their content.

I think I was over-thinking this before.  This is a new target type.
There is no reason the above cases need to be equivalent.

On 11/16/2012 12:56 PM, Stephen Kelly wrote:
> I've thought some more about the topic of targets which do not create any 
> output files or binaries themselves, but which provide an interface to a 
> group of other targets.
> 
> Whatever solution we come up with to do that, I'd like it to be consistent 
> with other types of targets. The way I see it, these are the options:
> 
> 1) cmTarget::INTERFACE_LIBRARY
> 
> 2) cmTarget::INLINED_LIBRARY or INLINE_CONTAINER_LIBRARY
[snip]
> 1) can be turned into 2) by the user by using a generator expression
> 
>  target_link_libraries(foo 
>     $<TARGET_PROPERTY:iface,INTERFACE_LINK_LIBRARIES>)

Yes, I think #1 is okay.

Thanks,
-Brad