[cmake-developers] conditionals in generator expressions

[Stephen Kelly]

Stephen Kelly wrote:

>>> The next thing I want to do is to see if I can make full use of
>>> cmGeneratorTarget and use const proactively while doing so, to make the
>>> code more clear. I'm not 100% certain that's possible, but it's the next
>>> goal I have. Any comments on that?
>>
>> That would be a really great example of splitting configure-time
>> constructs from generate-time constructs.
> 
> Right. I investigated a little bit already and it seems there's at least
> some low-hanging fruit.

I've put my work on the use-generator-target branch in my clone. 

Using const as proactively as I wanted is not really possible/worth it 
because of all the memoizing cmake does, but I've ported it to use 
cmGeneratorTarget enough to be able to add a

 cmGeneratorTarget::GetCompileDefinitions(const char *config) 

and use generator expressions in the implementation, and to use generator 
expressions in 

 cmGeneratorTarget::GetIncludeDirectories(const char *config) 

too. That should be three trivial patches, but I haven't written them yet. 
That's all I'm aiming for of the target_use_targets feature for the next 
release, so I think that's still on track.

Thanks,

Steve.