Building Zig on Windows

Note: If you want the latest build of Zig on Windows, you can get it from the download page.

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Option 1: Use the Windows Zig Compiler Dev Kit

This one has the benefit that LLVM, LLD, and Clang are built in Release mode, while your Zig build has the option to be a Debug build. It also works completely independently from MSVC so you don't need it to be installed.

The Dev Kit can be downloaded from a url that has the following form,

https://ziglang.org/deps/zig+llvm+lld+clang-x86_64-windows-gnu-$VERSION.zip

where you will need to replace $VERSION. To do this, determine the precise URL by looking at the CI script, specifically the variables $ZIG_LLVM_CLANG_LLD_NAME and $ZIG_LLVM_CLANG_LLD_URL (currently lines 2 and 4).

This zip file contains:

• An older Zig installation.
• LLVM, LLD, and Clang libraries (.lib and .h files), version 16.0.1, built in Release mode.
• zlib (.lib and .h files), v1.2.13, built in Release mode
• zstd (.lib and .h files), v1.5.2, built in Release mode

Option 1a: CMake + Ninja

Unzip the dev kit and then in cmd.exe in your Zig source checkout:

mkdir build
cd build
set DEVKIT=$DEVKIT

Replace $DEVKIT with the path to the folder that you unzipped after downloading it from the link above. Make sure to use forward slashes (/) for all path separators (otherwise CMake will try to interpret backslashes as escapes and fail).

Then run:

cmake .. -GNinja -DCMAKE_PREFIX_PATH="%DEVKIT%" -DCMAKE_C_COMPILER="%DEVKIT%/bin/zig.exe;cc" -DCMAKE_CXX_COMPILER="%DEVKIT%/bin/zig.exe;c++" -DCMAKE_AR="%DEVKIT%/bin/zig.exe" -DZIG_AR_WORKAROUND=ON -DZIG_STATIC=ON -DZIG_USE_LLVM_CONFIG=OFF

• Append -DCMAKE_BUILD_TYPE=Release for a Release build.
• Append -DZIG_NO_LIB=ON to avoid having multiple copies of the lib/ folder.

Finally, run:

ninja install

You now have the zig.exe binary at stage3\bin\zig.exe and you can run the tests:

stage3\bin\zig.exe build test

This can take a long time. For tips & tricks on using the test suite, see Contributing.

Option 1b: Zig build

The Dev Kit contains a Zig compiler that can be used to build Zig from source.

First unzip the Dev Kit. Let $DEVKIT denote the path to the unzipped Dev Kit. The Zig compiler in the Dev Kit is located at: $DEVKIT\bin\zig.exe.

Now navigate to the source of the compiler you wish to build. Then, using the Dev Kit compiler, attempt to build the compiler from source:

$DEVKIT\bin\zig.exe build -p stage3 --search-prefix $DEVKIT --zig-lib-dir lib -Dstatic-llvm -Duse-zig-libcxx -Dtarget=x86_64-windows-gnu

NOTE: In the command above, both instances of $DEVKIT will need to be substituted with the path to the unzipped Dev Kit.

Append -Doptimize=ReleaseSafe for a Release build.

You may get a build error during this step. In such a case, it is most likely that the Zig installation inside the dev kit is too old, and the dev kit needs to be updated. In this case one more step is required:

1. Download the latest master branch zip file.
2. Unzip, and try the above command again, replacing the path to zig.exe with the path to the zig.exe you just extracted, and also replace the lib\zig folder with the new contents.

You now have the zig.exe binary at stage3\bin\zig.exe and you can run the tests:

stage3\bin\zig.exe build test

This can take a long time. For tips & tricks on using the test suite, see Contributing.

Option 2: Using CMake and Microsoft Visual Studio

This one has the benefit that changes to the language or build system won't break your dev kit. This option can be used to upgrade a dev kit.

First, build LLVM, LLD, and Clang from source using CMake and Microsoft Visual Studio. Or, skip this step using a pre-built binary tarball, which unfortunately is not provided here.

Install Build Tools for Visual Studio 2019. Be sure to select "Desktop development with C++" when prompted.

• You must additionally check the optional component labeled C++ ATL for v142 build tools.

Install CMake.

Use git to clone the zig repository to a path with no spaces, e.g. C:\Users\Andy\zig.

Using the start menu, run x64 Native Tools Command Prompt for VS 2019 and execute these commands, replacing C:\Users\Andy with the correct value.

mkdir C:\Users\Andy\zig\build-release
cd C:\Users\Andy\zig\build-release
"c:\Program Files\CMake\bin\cmake.exe" .. -Thost=x64 -G "Visual Studio 16 2019" -A x64 -DCMAKE_PREFIX_PATH=C:\Users\Andy\llvm+clang+lld-13.0.1-x86_64-windows-msvc-release-mt -DCMAKE_BUILD_TYPE=Release
msbuild -p:Configuration=Release INSTALL.vcxproj

You now have the zig.exe binary at bin\zig.exe and you can run the tests:

bin\zig.exe build test

This can take a long time. For tips & tricks on using the test suite, see Contributing.

Note: In case you get the error "llvm-config not found" (or similar), make sure that you have no trailing slash (/ or \) at the end of the -DCMAKE_PREFIX_PATH value.