Ah, I understand now - I have a habit of forgetting that you can configure existing CMake builds by repeatedly invoking cmake. I don't know if such a feature exists but it definitely sounds useful.
On Sat, Mar 19, 2016 at 12:03 PM, René J. V. <rjvber...@gmail.com> wrote: > Nicholas Braden wrote: > > >> sense. Could you give an example of when you would find them useful? I >> think maybe I am not understanding what you want. > > Yeah, I realise my explanation may not have been very clear. > >> If you just want to pass a list of values to a variable on the command >> line, separate the values with semicolons: >> cmake "-DMY_LIST=example value 1;example value 2" > > > Now take an example where you are in fact assembling the commandline in > subsequent steps. A good example would be a build system like MacPorts that > uses > a kind of header files (so-called PortGroups) that can be included by the > build > scripts for packages of dependent software (say, the Kate5 editor). There's a > PortGroup for cmake itself, and there's a PortGroup for Qt5 and one for the > KF5 > frameworks. Each of those PortGroups can provide an element for MY_LIST (think > of the module path, or preprocessor tokens), but evidently they cannot make > assumptions about the contents of the variable. > > In other words, it would make sense for certain types of programmatically > generated commandlines to do things like > > cmake -DMY_LIST+=val1 -DMY_LIST+=val3 -DMY_LIST+=val2 > > At the moment we can do this reliably by using our own registers, one for each > CMake variable that might be used this way, splicing them into the commandline > just before invoking cmake. Not impossible, but somewhat of a hassle and a > pity > for a feature that seems useful and probablye rather trivial to implement. > > CMake commandline can get quite long, so this might even make sense as a > convenience for composing one manually. > > Of course it would be convenient to have a concatenation operator in the cmake > language too ;) > > R > > > -- > > Powered by www.kitware.com > > Please keep messages on-topic and check the CMake FAQ at: > http://www.cmake.org/Wiki/CMake_FAQ > > Kitware offers various services to support the CMake community. For more > information on each offering, please visit: > > CMake Support: http://cmake.org/cmake/help/support.html > CMake Consulting: http://cmake.org/cmake/help/consulting.html > CMake Training Courses: http://cmake.org/cmake/help/training.html > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Follow this link to subscribe/unsubscribe: > http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake
