To build just CoreCLR, use the -subset
flag to the build.sh
(or build.cmd
) script at the repo root:
For Linux:
./build.sh -subset clr
For Windows:
build.cmd -subset clr
By default, build generates a 'debug' build type, that includes asserts and is easier for some people to debug. If you want to make performance measurements, or just want tests to execute more quickly, you can also build the 'release' version (which does not have these checks) by adding the flag -configuration release
(or -c release
), for example:
./build.sh -subset clr -configuration release
CoreCLR also supports a 'checked' build type which has asserts enabled like 'debug', but is built with the native compiler optimizer enabled, so it runs much faster. This is the usual mode used for running tests in the CI system. You can build that using, for example:
./build.sh -subset clr -configuration checked
If you want to use Ninja to drive the native build instead of Visual Studio MSBuild (on Windows) or Make (on non-Windows), you can pass the -ninja
flag to the build script as follows:
./build.cmd -subset clr -ninja
We recommend using Ninja for building the project on Windows since it more efficiently uses the build machine's resources for the native runtime build in comparison to Visual Studio's MSBuild.
To pass extra compiler/linker flags to the coreclr build, set the environment variables EXTRA_CFLAGS
, EXTRA_CXXFLAGS
and EXTRA_LDFLAGS
as needed. Don't set CFLAGS
/CXXFLAGS
/LDFLAGS
directly as that might lead to configure-time tests failing.
This will produce outputs as follows:
- Product binaries will be dropped in
artifacts\bin\coreclr\<OS>.<arch>.<flavor>
folder. - A NuGet package, Microsoft.Dotnet.CoreCLR, will be created under
artifacts\bin\coreclr\<OS>.<arch>.<flavor>\.nuget
folder. - Test binaries will be dropped under
artifacts\tests\coreclr\<OS>.<arch>.<flavor>
folder. However, the root build script will not build the tests.
The build places logs in artifacts\log
and these are useful when the build fails.
The build places all of its intermediate output in the artifacts\obj\coreclr
directory, so if you remove that directory you can force a
full rebuild.
To build CoreCLR, the root build script invokes the src\coreclr\build.cmd
(or build.sh) script. To build the CoreCLR tests, you must use this script.
Use build -?
to learn about the options to this script.
See Running Tests for instructions on running the tests.
See also Build CoreCLR on Linux, Build CoreCLR on OS X, Build CoreCLR on FreeBSD, Cross Compilation for ARM on Windows, Cross Compilation for Android on Linux.