On 2015-02-11 09:44-0500 Brad King wrote:
Also one would need to decide what determines whether an optional language is not available. If a compiler is available but cannot compile binaries, should that be an error or tolerated as "not available"? As a user I would expect setting FC=/path/to/gfortran in my environment before calling CMake to cause Fortran to be enabled if the project wants it or else an error.
Tolerated with a warning please. Unsophisticated users could have environment variables set that they are completely unaware of. And I have run across scientific users of Fortran who assumed that Fortran compiler options (which can be set either with the FC variable or FFLAGS) were universal regardless of compiler (so they were inadvertently attempting to use some exotic solaris fortran compiler options for gfortran).
From these experiences with unsophisticated compiler users, my own
feeling is OPTIONAL should mean just that, i.e., warn instead of error out for all cases. That's how we currently deploy the workaround for PLplot, and I have never had a user complaint about getting those soft landings when a compiler didn't work properly. (Maybe because our warning messages are really obvious when a compiler does not work.) Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); the Time Ephemerides project (timeephem.sf.net); PLplot scientific plotting software package (plplot.sf.net); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ -- 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-developers
