Make ScopedMetric portable, accurate, and efficient ScopedMetric used to use separate code paths for Win32 and other platforms. std::chrono makes it practical to use the same code everywhere. This requires C++ 11 so that is specified in the configuration file (C++ 11 was already used on Win32 builds). This change also makes ScopedMetric more accurate because it postpones converting the raw deltas until it is time to report them. Previously they would be converted at each measurement site, potentially losing almost a microsecond each time. Postponing the conversion also reduces the cost of ScopedMetric. The performance of std::chrono is currently harmed a bit by some design and code-gen issues in VC++, but bugs have been filed and these should be fixed. The overhead is low enough to be inconsequential for the O(15,000) ScopedMetric objects created in a build of Chrome. The net result is that the ScopedMetric code is now portable, more accurate, and as fast or faster than it used to be. This will resolve issue #2004.
Ninja is a small build system with a focus on speed. https://ninja-build.org/
See the manual or doc/manual.asciidoc included in the distribution for background and more details.
Binaries for Linux, Mac, and Windows are available at GitHub. Run ./ninja -h for Ninja help.
Installation is not necessary because the only required file is the resulting ninja binary. However, to enable features like Bash completion and Emacs and Vim editing modes, some files in misc/ must be copied to appropriate locations.
If you're interested in making changes to Ninja, read CONTRIBUTING.md first.
You can either build Ninja via the custom generator script written in Python or via CMake. For more details see the wiki.
./configure.py --bootstrap
This will generate the ninja binary and a build.ninja file you can now use to build Ninja with itself.
cmake -Bbuild-cmake -H. cmake --build build-cmake
The ninja binary will now be inside the build-cmake directory (you can choose any other name you like).
To run the unit tests:
./build-cmake/ninja_test