On 10/07/2014 04:53 PM, Adam Strzelecki wrote: > In meantime I've pushed stage/cmp0055-disable-ninja-side-effects > that make CMake warn about this compatibility layer when such > phony rules are about to be emitted.
What I've been trying to say is that this is NOT about compatibility with broken projects. It is a *fundamental limitation* of the current CMake custom command specification interface (add_custom_command). If you start requiring explicit specification of side-effects as custom command outputs, you will make it *impossible* for project code to specify their build rules for cases involving side-effect outputs whose timestamps do not need to be newer than their inputs. Non-Ninja build systems do *not* support this. This issue: Add explicit specification of custom command side effect outputs http://www.cmake.org/Bug/view.php?id=14963 documents a few such cases. It explains that we need a new interface, perhaps as an option to add_custom_command, to specify side-effect outputs of rules. Another possible middle-ground workaround is to generate phony rules only for custom command dependencies that are marked with the GENERATED property. That would avoid the phony rule bloat and simply require projects to explicitly mark their generated side effects. We still won't be able to tell Ninja which rule generates them, but at least we could reduce the number of phony rules. However, there is no way this will be done for 3.1 by tomorrow, so it would be best to think about a full solution to #14963 to start development now and target the 3.2 release. -Brad -- 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
