Just a note.. . That method does NOT work with windows... And since the visual studio project has the external as a single command, (not sure if its calling nmake or the new build cmd) the proeject is not run in parallel.
Scott -----Original Message----- From: CMake [mailto:cmake-boun...@cmake.org] On Behalf Of Scott Aron Bloom Sent: Wednesday, March 23, 2016 8:53 PM To: Alan W. Irwin Cc: cmake@cmake.org Subject: Re: [CMake] Two phase install? > Thanks I'm getting close now. > > However, for the two sub projects, there doesn’t seem to be a way to run the > make stage with -j 6 or any make options. > > Am I missing something? I see how to set CMAKE_ARGS but no MAKE_ARGS Hi Scott: Some of my further comments are somewhat off your original topic since I discuss parallel build issues for the case of larger numbers of projects in the superproject, but I thought you might be interested in that case even though you just have two projects in your superproject. For the superproject (epa_build in my case) I configure the EPA_PARALLEL_BUILD_COMMAND variable to create the build command that I use for all individual projects. That can be anything accessible from the command-line such as nmake in the Windows case and make in the Unix case. So in your case, your overall superproject could specify set(SUPERPROJECT_BUILD_COMMAND make -j4) (say), and then each of your two projects could be configured via ExternalProject_Add to use ${SUPERPROJECT_BUILD_COMMAND} as the build command for each individual project. But getting back to the more complex case, for Unix on Windows (e.g. Cygwin, MinGW-w64/MSYS2, MinGW/MSYS) I find parallel build options are not reliable (presumably because of make bugs in all those platforms) so to work around that issue, epa_build deliberately drops any -j options that might be specified in EPA_PARALLEL_BUILD_COMMAND for those platforms. But for the Linux case (and I assume Mac OS X, also although I haven't tried it yet), the -j option for make does work reliably so I allow that option to be part of the EPA_PARALLEL_BUILD_COMMAND for that platform. N.B. with 60 projects being built (each one using a parallel build on Linux) with one overall make command, I am currently careful to build each of those projects one at a time (i.e., avoid any parallel options on the overall build or just use -j1) to avoid overwhelming my computer with parallel builds. However, come to think of it I have always used that combination of -j options (-j4 for individual project builds and -j1 for overall build) out of inertia, and there are many other ways that avoidance can be done (e.g., -j4 on the overall build and -j1 on the individual builds) so long as the product of the two integers specified by the -j options does not get too excessive. So I may do some experimentation concerning the most efficient combination of individual and overall -j options the next time I do an epa_build on Linux. Alan ========== Thanks that is what I was planning. I was just hoping, there was a variable I was missing in the docs I have it working now on linux, off to try and see how it works with windows Scott -- 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
