On 06/26/2011 04:12 PM, Owen Shepherd wrote: > On 25/06/2011 07:30, "Michael Hertling" <mhertl...@online.de> wrote: > >> On 06/24/2011 04:16 PM, Owen Shepherd wrote: >>> I think the appropriate solution here is a project-specific dialect >>> flag - >>> perhaps one taking options in the GNU format since it seems most >>> familiar. >>> One could perhaps generalise this further - a file-specific dialect flag >>> which defaults to the value of the project-specific flag >> >> If there are individual compilers for C89/C99, and a projects needs a >> C99 one, any dialect flags - project/directory/target/file specific - >> would be of no use, wouldn't they? Rather, one must specify the C99 >> compiler if it isn't found automatically by CMake during the initial >> configuration, and the project might consider to check the compiler's >> C99 capabilities. > > Sorry - I should have said property rather than flag. That is, something > along the lines of > set_target_properties(the_target PROPERTIES C_DIALECT C99) > Or > set_source_files_properties(myfile.c PROPERTIES C_DIALECT C99) > > (I'm not entirely sure here whether the source file property should be > C_DIALECT or just DIALECT. The language, after all, should be unambiguous > at this point) > > It would then be the responsibility of the Cmake machinery to choose the > right compiler and set it up for building code with the given dialect.
This would require to configure the entire project *before* the compiler is chosen, and this means that constructs like IF(CMAKE_C_COMPILER_ID STREQUAL ...) or IF(CMAKE_COMPILER_IS_GNUC) wouldn't work anymore. Of course, they're quite useful and necessary if one wants to enable compiler-specific features, so the compiler must be chosen at the very beginning. Moreover, IMO, it's absolutely inevitable that the responsibility for choosing a suitable compiler rests on the user. The fact that CMake usually finds a suitable one automatically - although common and very convenient - should be considered as the exception rather than the rule, at least in multi-compiler setups. Regards, Michael _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
