[cmake-developers] Generator expressisons in target properties

[Brad King]

On 11/07/2012 08:30 AM, Stephen Kelly wrote:
> I'm a bit confused by this line. In a union, where does the duplication come 
> from? 

The term "union" is an unordered set operation.  Order matters here.

> The upstream will generate different properties which contain duplicate 
> information. Lets say this is generated:

I think this example would be easier to understand if you write out:

(1) What the upstream CMakeLists.txt file contains
(2) What the export files contain
(3) What the application contains

Right now I only care about cases where the projects have not been modified
and use only the old interfaces, but tll() enables the new interfaces.

Note that the old-style per-config interface completely overrides
the configless form in current behavior:

 http://www.cmake.org/cmake/help/v2.8.10/cmake.html#prop_tgt:LINK_INTERFACE_LIBRARIES_CONFIG
 "this property completely overrides the generic property for the named configuration"

If INTERFACE_LINK_LIBRARIES is set with a generator expression to handle
the debug case (constructed by tll), and LINK_INTERFACE_LIBRARIES_DEBUG
is set, then which one should 2.8.11 use in the consumer?

-Brad