On Sun, Dec 27, 2015 at 22:04:14 +0100, Dimitar Yordanov wrote: > I agree with you. Running valgrind directly on the cmake binary > provides useful information: I can see which internal cmake functions > are used the most and consume most of the time. > > Nevertheless, I think it would be useful to have a higher level > overview. E.g. to see if there are some issues with the scripts > themselves that I use in my project ...
I had patches which did this, but it doesn't really help much. At least I didn't think it did. The problems are mainly in CMake itself (regular expressions, path parsing, etc.). I think the next big improvement would be caching variable values which are parsed as numbers, on/off, and paths as a more structured state so that if you have a path, path operations don't have to keep searching for directory separators since it is already in a std::vector<cmPathComponent> structure. > > Usually you see mostly string handling related functions. > > malloc and free are on the top of what I see for a random project used > mostly by std::string. Maybe we can optimize something here too? I did a lot of profiling of CMake two years ago. I fixed the low-hanging fruit (rewriting the CMakeLists.txt parser/variable expander (CMP0053 if you aren't using it), fixing other mini-parsers (escape routines, the genex parser) to chunk rather than do char-by-char iteration, etc.). The big remaining problem is passing char* as an argument where functions do std::string(arg) right away. I fixed all of those which did explicit std::string conversions (via assignment or otherwise), but those which are conditional should get std::string overloads to avoid a malloc/copy/free penalty. There is a *lot* of work here though. The branch I had been working on (which is now woefully out-of-date) is 100 commits long. --Ben -- 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
