swift-mirror/docs/WindowsBuild.md

Building Swift on Windows

This document describes how to build Swift for Windows natively. See the Windows doc for more about what is possible with Swift on Windows.

There are two supported ways to build Swift on Windows, they are

1. Using clang-cl
2. Using the Microsoft Visual C++ compiler (MSVC)

clang-cl is recommended over MSVC for building Swift on Windows.

Although it is possible to build the compiler and the standard library with MSVC and to use those built products to compile a Swift program, it won't be possible to run the binary without separately obtaining the Swift runtime. On the other hand, clang-cl is able to build the runtime, which makes it possible to build and run all the components required for Swift natively on Windows.

clang should be 7.0 or newer. Visual Studio 2017 is needed in all cases as it provides some of the needed headers and libraries.

clang-cl

1. Install dependencies

1. Latest version of Visual Studio

• Make sure to include "Programming Languages|Visual C++" and "Windows and Web Development|Universal Windows App Development|Windows SDK" in your installation.

2. Clone the repositories

1. Configure git to work with Unix file endings
2. Create a folder to contain all the Swift repositories
3. Clone apple/swift-cmark into a folder named cmark
4. Clone apple/swift-clang into a folder named clang
5. Clone apple/swift-llvm into a folder named llvm
6. Clone apple/swift-compiler-rt into a folder named compiler-rt
7. Clone apple/swift into a folder named swift
8. Clone apple/swift-corelibs-libdispatch into a folder named swift-corelibs-libdispatch
9. Clone apple/swift-corelibs-foundation into a folder name swift-corelibs-foundation

• Currently, other repositories in the Swift project have not been tested and may not be supported.

If your sources live else where, you can create a substitution for this:

subst S: <path to sources>

git config --global core.autocrlf input
S:
git clone https://github.com/apple/swift-cmark cmark
git clone https://github.com/apple/swift-clang clang
git clone https://github.com/apple/swift-llvm llvm
git clone https://github.com/apple/swift-compiler-rt compiler-rt
git clone https://github.com/apple/swift
git clone https://github.com/apple/swift-corelibs-libdispatch
git clone https://github.com/apple/swift-corelibs-foundation

3. Acquire ICU

1. Download ICU from ICU Project for Windows x64 and extract the binaries.
2. Add the bin64 folder to your Path environment variable.

4. Get ready

• From within a developer command prompt (not PowerShell nor cmd, but the Visual Studio Developer Command Prompt), execute the following command if you have an x64 PC.

VsDevCmd -arch=amd64

If instead you're compiling for a 32-bit Windows target, adapt the arch argument to x86 and run

VsDevCmd -arch=x86

• Decide whether you want to build a release or debug version of Swift on Windows and replace the CMAKE_BUILD_TYPE parameter in the build steps below with the correct value (Debug, RelWithDebInfoAssert or Release) to avoid conflicts between the debug and non-debug version of the MSCRT library.

• Set up the ucrt, visualc, and WinSDK modules by copying ucrt.modulemap located at swift/stdlib/public/Platform/ucrt.modulemap into ${UniversalCRTSdkDir}/Include/${UCRTVersion}/ucrt as module.modulemap, copying visualc.modulemap located at swift/stdlib/public/Platform/visualc.modulemap into ${VCToolsInstallDir}/include as module.modulemap, and copying winsdk.modulemap located at swift/stdlib/public/Platform/winsdk.modulemap into ${UniversalCRTSdkDir}/Include/${UCRTVersion}/um and setup the visualc.apinotes located at swift/stdlib/public/Platform/visualc.apinotes into ${VCToolsInstallDir}/include as visualc.apinotes

mklink "%UniversalCRTSdkDir%\Include\%UCRTVersion%\ucrt\module.modulemap" S:\swift\stdlib\public\Platform\ucrt.modulemap
mklink "%VCToolsInstallDir%\include\module.modulemap" S:\swift\stdlib\public\Platform\visualc.modulemap
mklink "%VCToolsInstallDir%\include\visualc.apinotes" S:\swift\stdlib\public\Platform\visualc.apinotes
mklink "%UniversalCRTSdkDir%\Include\%UCRTVersion%\um\module.modulemap" S:\swift\stdlib\public\Platform\winsdk.modulemap

5. Build CMark

• This must be done from within a developer command prompt. CMark is a fairly small project and should only take a few minutes to build.

mkdir S:\build\Ninja-DebugAssert\cmark-windows-amd64"
pushd S:\build\Ninja-DebugAssert\cmark-windows-amd64" "S:\cmark"
cmake -G Ninja^
  -DCMAKE_BUILD_TYPE=Debug^
  -DCMAKE_C_COMPILER=cl^
  -DCMAKE_CXX_COMPIELR=cl^
  S:\cmark
popd
cmake --build "S:\build\Ninja-DebugAssert\cmark-windows-amd64"

6. Build LLVM/Clang

• This must be done from within a developer command prompt. LLVM and Clang are large projects, so building might take a few hours. Make sure that the build type (e.g. Debug, Release, RelWithDebInfoAssert) for LLVM/Clang matches the build type for Swift.

mkdir "S:\build\Ninja-DebugAssert\llvm-windows-amd64"
pushd "S:\build\Ninja-DebugAssert\llvm-windows-amd64"
cmake -G "Ninja"^
 -DCMAKE_BUILD_TYPE=Debug^
 -DCMAKE_C_COMPILER=cl^
 -DCMAKE_CXX_COMPILER=cl^
 -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-windows-msvc^
 -DLLVM_ENABLE_ASSERTIONS=TRUE^
 -DLLVM_ENABLE_PROJECTS=clang^
 -DLLVM_TARGETS_TO_BUILD=X86^
 "S:\llvm"
popd
cmake --build "S:\build\Ninja-DebugAssert\llvm-windows-amd64"

• Update your path to include the LLVM tools.

set PATH=%PATH%;S:\build\Ninja-DebugAssert\llvm-windows-amd64\bin

7. Build Swift

• This must be done from within a developer command prompt and could take hours depending on your system.
• You may need to adjust the SWIFT_WINDOWS_LIB_DIRECTORY parameter depending on your target platform or Windows SDK version.

mkdir "S:\build\Ninja-DebugAssert\swift-windows-amd64"
pushd "S:\build\inja-DebugAssert\swift-windows-amd64"
cmake -G "Ninja"^
 -DCMAKE_BUILD_TYPE=Debug^
 -DCMAKE_C_COMPILER=clang-cl^
 -DCMAKE_CXX_COMPILER=clang-cl^
 -DSWIFT_PATH_TO_CMARK_SOURCE="S:\cmark"^
 -DCMAKE_CXX_FLAGS="-Wno-c++98-compat -Wno-c++98-compat-pedantic"^
 -DCMAKE_EXE_LINKER_FLAGS:STRING="/INCREMENTAL:NO"^
 -DCMAKE_SHARED_LINKER_FLAGS="/INCREMENTAL:NO"^
 -DSWIFT_INCLUDE_DOCS=NO^
 -DSWIFT_PATH_TO_LLVM_SOURCE="S:\llvm"^
 -DSWIFT_PATH_TO_CLANG_SOURCE="S:\clang"^
 -DSWIFT_PATH_TO_LIBDISPATCH_SOURCE="S:\swift-corelibs-libdispatch"^
 -DSWIFT_PATH_TO_LLVM_BUILD="S:\build\Ninja-DebugAssert\llvm-windows-amd64"^
 -DSWIFT_PATH_TO_CLANG_BUILD="S:\build\Ninja-DebugAssert\llvm-windows-amd64"^
 -DSWIFT_PATH_TO_CMARK_BUILD="S:\build\Ninja-DebugAssert\cmark-windows-amd64"^
 -DSWIFT_WINDOWS_x86_64_ICU_UC_INCLUDE="S:\icu\include"^
 -DSWIFT_WINDOWS_x86_64_ICU_UC="S:\icu\lib64\icuuc.lib"^
 -DSWIFT_WINDOWS_x86_64_ICU_I18N_INCLUDE="S:\icu\include"^
 -DSWIFT_WINDOWS_x86_64_ICU_I18N="S:\icu\lib64\icuin.lib"^
 -DCMAKE_INSTALL_PREFIX="C:\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr"^
 "S:\swift"
popd
cmake --build "S:\build\Ninja-DebugAssert\swift-windows-amd64"

• To create a Visual Studio project, you'll need to change the generator and, if you have a 64 bit processor, specify the generator platform. Note that you may get multiple build errors compiling the swift project due to an MSBuild limitation that file paths cannot exceed 260 characters. These can be ignored, as they occur after the build when writing the last build status to a file.

cmake -G "Visual Studio 2017" "S:\swift" -DCMAKE_GENERATOR_PLATFORM="x64"^ ...

8. Build lldb

• This must be done from within a developer command prompt and could take hours depending on your system.

mkdir "S:/build/Ninja-DebugAssert/lldb-windows-amd64"
pushd "S:/build/Ninja-DebugAssert/lldb-windows-amd64"
cmake -G "Ninja" "S:/lldb"^
  -DCMAKE_BUILD_TYPE=Debug^
  -DLLDB_PATH_TO_CMARK_SOURCE="S:/cmark"^
  -DLLDB_PATH_TO_LLVM_SOURCE="S:/llvm"^
  -DLLDB_PATH_TO_CLANG_SOURCE="S:/clang"^
  -DLLDB_PATH_TO_SWIFT_SOURCE="S:/swift"^
  -DLLDB_PATH_TO_CMARK_BUILD="S:/build/Ninja-DebugAssert/cmark-windows-amd64"^
  -DLLDB_PATH_TO_CLANG_BUILD="S:/build/Ninja-DebugAssert/llvm-windows-amd64"^
  -DLLDB_PATH_TO_LLVM_BUILD="S:/build/Ninja-DebugAssert/llvm-windows-amd64"^
  -DLLDB_PATH_TO_SWIFT_BUILD="S:/build/Ninja-DebugAssert/swift-windows-amd64"^
  -DLLVM_ENABLE_ASSERTIONS=YES
popd
cmake --build "S:/build/Ninja-DebugAssert/lldb-windows-amd64"

9. Running tests on Windows

Running the testsuite on Windows has additional external dependencies. You must have a subset of the GNUWin32 programs installed and available in your path. The following packages are currently required:

1. coreutils
2. diffutils
3. file
4. grep
5. sed

ninja -C "S:/build/Ninja-DebugAssert/swift-windows-amd64" check-swift

10. Build swift-corelibs-libdispatch

mkdir "S:/build/Ninja-DebugAssert/swift-corelibs-libdispatch-windows-amd64"
pushd "S:/build/Ninja-DebugAssert/swift-corelibs-libdispatch-windows-amd64"
cmake -G "Ninja"^
  -DCMAKE_BUILD_TYPE=Debug^
  -DCMAKE_C_COMPILER="S:/build/Ninja-DebugAssert/llvm-windows-amd64/bin/clang-cl.exe"^
  -DCMAKE_CXX_COMPILER="S:/build/Ninja-DebugAssert/llvm-windows-amd64/bin/clang-cl.exe"^
  -DCMAKE_SWIFT_COMPILER="S:/build/Ninja-DebugAssert/swift-windows-amd64/bin/swiftc.exe"^
  -DSwift_DIR="S:/build/Ninja-DebugAssert/swift-windows-amd64/lib/cmake/swift"^
  -DENABLE_SWIFT=YES^
  -DENABLE_TESTING=NO^
  S:/swift-corelibs-libdispatch
popd
cmake --build

11. Build swift-corelibs-foundation

mkdir "S:/build/Ninja-DebugAssert/swift-corelibs-foundation-windows-amd64"
pushd "S:/build/Ninja-DebugAssert/swift-corelibs-foundation-windows-amd64"
cmake -G "Ninja"^
  -DCMAKE_BUILD_TYPE=Debug^
  -DCMAKE_C_COMPILER="S:/build/Ninja-DebugAssert/llvm-windows-amd64/bin/clang-cl.exe"^
  -DCMAKE_SWIFT_COMPILER="S:/build/Ninja-DebugAssert/swift-windows-amd64/bin/swiftc.exe"^
  -DCURL_LIBRARY="S:/curl/builds/libcurl-VS15-x64-release-static-ipv6-sspi-winssl/lib/libcurl_a.lib"^
  -DCURL_INCLUDE_DIR="S:/curl/builds/libcurl-VS15-x64-release-static-ipv6-sspi-winssl/include"^
  -DICU_ROOT="S:/thirdparty/icu4c-63_1-Win64-MSVC2017"^
  -DLIBXML2_LIBRARY="S:/libxml2/win32/bin.msvc/libxml2_a.lib"^
  -DLIBXML2_INCLUDE_DIR="S:/libxml2/include"^
  -DFOUNDATION_PATH_TO_LIBDISPATCH_SOURCE="S:/swift-corelibs-libdispatch"^
  -DFOUNDATION_PATH_TO_LIBDISPATCH_BUILD="S:/build/Ninja-DebugAssert/swift-corelibs-libdispatch-windows-amd64"^
   "S:/swift-corelibs-foundation"
 cmake --build "S:/build/Ninja-DebugAssert/swift-corelibs-foundation-windows-amd64"

12. Install Swift on Windows

• Run ninja install:

ninja -C "S:/build/Ninja-DebugAssert/swift-windows-amd64" install

• Add the Swift on Windows binaries path (C:\Library\Developer\Toolchains\unknown-Asserts-development.xctoolchain\usr\bin) to the PATH environment variable.

MSVC

To use cl instead, just replace the -DCMAKE_C_COMPILER and -DCMAKE_CXX_COMPILER parameters to the cmake invocations.