[cmake-developers] Generator expressions in target properties

[Stephen Kelly]

Brad King wrote:

> On 11/20/2012 11:03 AM, Stephen Kelly wrote:
>> I have only tested on linux though so far. I'm still hoping to get this
>> into 2.8.11, and hoping to get it into next 'soon' for real testing.
> 
> I won't have time to do a thorough review until after this week (US
> holiday) but here are some quick comments:

Thanks for the review so far.

> 
> - I'd like to see the INTERFACE_LINK_LIBRARIES property and policy
>   added earlier in the topic if possible so we can test it separately.
>   It does not appear to depend on the "$<BUILD_INTERFACE:...>" changes.
>   In general I'd like to handle the topic in most-invasive to least-
>   invasive order so we can incrementally merge and test in pieces.
>   (Where "invasive" refers to effects on existing projects.)

I can look into that, but in general my preference is least-invasive (eg 
cleanups) to most-invasive. In particular the first three commits in the 
branch I would like to get in first as a standalone topic (eg revert-use-
generator-target) because they are a minimally 'invasive' cleanup. I can 
then move the INTERFACE_LINK_LIBRARIES commit to be first in the rest of the 
topic.

> 
> - The $<EXPNS> expression is too abbreviated.  I think
>   $<EXPORT_NAMESPACE> is better.  People can always do
>   set(ns "$<EXPORT_NAMESPACE>") and then use ${ns}.

Ok, I also thought it was too abbreviated.

> - The std::auto_ptr from <memory> is not portable to ancient compilers.
>   Use cmsys::auto_ptr as one can see elsewhere in CMake.

Yes, I saw cmsys::auto_ptr, but std::auto_ptr is also used in CMake. (eg, 
cmake::ReadListFile), so I guess the ancient compilers that used to not work 
with std::auto_ptr are no longer on the dashboard. 

I'm all for consistency, but in which direction? There is an argument for 
porting away from and removing cmsys::auto_ptr.

> 
> - The $<TARGET:tgt> expression will be too easily confused with
>   the $<TARGET_FILE:tgt> expression IMO.  Perhaps something like
>   $<TARGET_EXISTS:tgt> or $<TARGET_DEFINED:tgt> is better.

Yes, I'll go with $<TARGET_DEFINED:tgt>.

> - CMP0020 does not appear to have a WARN implementation.

Oops. :)

I've been looking at this stuff for too long...

Thanks,

Steve.