[CMake] Restrictions on where a binary can be put?

[Alexander Neundorf]

On Sunday 09 January 2011, Michael Hertling wrote:
> On 01/09/2011 09:47 PM, Nizar Khalifa Sallem wrote:
> > At Sun, 09 Jan 2011 21:42:49 +0100,
> >
> > Michael Hertling wrote:
> >> On 01/09/2011 09:09 PM, Andreas Pakulat wrote:
> >>> On 09.01.11 21:05:21, Andreas Pakulat wrote:
> >>>> On 09.01.11 14:24:16, Michael Hertling wrote:
> >>>>> On 01/09/2011 12:58 PM, Andreas Pakulat wrote:
> >>>>>> Hi,
> >>>>>>
> >>>>>> I'm having a bit of a problem here changing the runtime output
> >>>>>> directory for a binary. Its an executable target named 'setup' and
> >>>>>> I'd like to put it into the top-level directory. Unfortunately it
> >>>>>> always ends up in the bin/ directory, which is what
> >>>>>> CMAKE_RUNTIME_OUTPUT_DIRECTORY is being set to.
> >>>>>>
> >>>>>> I'm using
> >>>>>>     set_target_properties( setup PROPERTIES RUNTIME_OUTPUT_DIRECTORY
> >>>>>> ${CMAKE_BINARY_DIR} ) after creating the target currently, which
> >>>>>> should work as far as I can see from the documentation. Are there
> >>>>>> maybe any restrictions on what the directory may be or what targets
> >>>>>> can be put there?
> >>>>>>
> >>>>>> If not, any suggestions how to debug this? I can see that the
> >>>>>> build.make does already have the rule setup for putting the binary
> >>>>>> into bin/, so it must be going wrong somewhere in the generation
> >>>>>> stage, but a simple cmake --trace doesn't show up anything
> >>>>>> suspicious. Is there a switch to follow the steps that cmake does
> >>>>>> during makefile-generation?
> >>>>>
> >>>>> Could you provide a minimal but complete example?
> >>>>
> >>>> Ok, attached case produces the error. Apparently the problem is
> >>>> fetching the LOCATION property from the target and setting the
> >>>> RUNTIME_OUTPUT_DIRECTORY afterwards. Looks like a cmake bug to me, so
> >>>> I'll file a report.
> >>>
> >>> Ooops, forgot the attachment :)
> >>
> >> Now, I can confirm the issue; indeed, the GET_TARGET_PROPERTY() on the
> >> LOCATION apparently renders the following SET_TARGET_PROPERTY() on the
> >> RUNTIME_OUTPUT_DIRECTORY ineffective. As I cannot see any reason for
> >> this, I'd agree that it should be considered as a bug. Besides, my
> >> example was pointless: A simple clash of an executable "main" with
> >> a subdirectory of the same name in CMAKE_BINARY_DIR, sorry. :/
> >>
> >> Regards,
> >>
> >> Michael
> >
> > I don't really understand why you want to get the LOCATION from your
> > target, anyway, the get_target_property works fine if you use
> > set_target_properties before it. [...]
>
> ...but SET_TARGET_PROPERTIES() doesn't work fine if it's used after
> GET_TARGET_PROPERTY(), even if both operate on different properties.

Well, they are not completely different.
If I remember correctly, the LOCATION property is "calculcated" when you query 
it. I think it changes some internal variables. Apparently to a state where 
setting the target property afterwards doesn't have the desired effect 
anymore :-/

Alex