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 use those built products to compile a Swift program, it won't be possible to run the binary without seperately 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-cl

• Windows doesn't currently have a build script. You'll need to run commands manually to build Swift on Windows.
• Windows support for Swift is a work in progress and may not work on your system, but it has been tested.
• Using the latest Visual Studio version is recommended (tested with Visual Studio 2017 - Version 15.5.5). Swift may fail to build with older C++ compilers.
• Note that the release version of Swift on Windows may crash when you try to compile a Swift program. See bug report SR-7867.

1. Install dependencies

1. Latest version (2.7.12 tested) of Python 2
2. Latest version (3.7.0-rc3 tested) of CMake
3. Latest version (1.7.1 tested) of Ninja
4. Latest version (2015 Update 3 tested) 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.
• Make sure to add Python, CMake and Ninja to your Path environment variable

2. Clone the repositories

1. Create a folder to contain all the Swift repositories
2. Clone apple/swift-cmark into a folder named cmark
3. Clone apple/swift-clang into a folder named clang
4. Clone apple/swift-llvm into a folder named llvm
5. Clone apple/swift-compiler-rt into a folder named compiler-rt
6. Clone apple/swift into a folder named swift

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

3. Build ICU

1. Download and extract the ICU source code to a folder named icu in the same directory as the other Swift project repositories (tested with ICU versions 55.1 and 59.1).
2. Open src/win32/allinone.sln in Visual Studio.
3. Make sure to select the correct architecture from the drop-down in Visual Studio.
4. Right click on the solution in the Solution Explorer window and select "Build Solution".
5. When this is done, add the <icu-source>/bin 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

• Then adapt the following command and run it. Make sure to use forward slashes (/) instead of backslashes (\) as the path separators. clang breaks with backslashed paths.

set swift_source_dir=path-to-directory-containing-all-cloned-repositories

• 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.

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 "%swift_source_dir%/build/Ninja-DebugAssert/cmark-windows-amd64"
pushd "%swift_source_dir%/build/Ninja-DebugAssert/cmark-windows-amd64"
cmake -G "Ninja" -DCMAKE_BUILD_TYPE=Debug "%swift_source_dir%/cmark"
popd
cmake --build "%swift_source_dir%/build/Ninja-DebugAssert/cmark-windows-amd64/"

6. Build LLVM/Clang/Compiler-RT

• 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.
• Optionally, you can omit building compiler-rt by removing all lines referring to compiler-rt below, which should give faster build times.

mklink /J "%swift_source_dir%/llvm/tools/clang" "%swift_source_dir%/clang"
mklink /J "%swift_source_dir%/llvm/tools/compiler-rt" "%swift_source_dir%/compiler-rt"
mkdir "%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"
pushd "%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"
cmake -G "Ninja"^
 -DLLVM_ENABLE_ASSERTIONS=TRUE^
 -DCMAKE_BUILD_TYPE=Debug^
 -DLLVM_TOOL_SWIFT_BUILD=NO^
 -DLLVM_INCLUDE_DOCS=TRUE^
 -DLLVM_TOOL_COMPILER_RT_BUILD=TRUE^
 -DLLVM_BUILD_EXTERNAL_COMPILER_RT=TRUE^
 -DLLVM_LIT_ARGS=-sv^
 -DLLVM_TARGETS_TO_BUILD=X86^
 "%swift_source_dir%/llvm"
popd
cmake --build "%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"

• Store the LLVM bin directory in an environment variable so it can be used to build Swift. Assuming you followed the instructions exactly, the path below is correct, but it may be different based on your build variant and platform, so double check.

set llvm_bin_dir="%swift_source_dir%/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 "%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"
pushd "%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"
cmake -G "Ninja" "%swift_source_dir%/swift"^
 -DCMAKE_BUILD_TYPE=Debug^
 -DSWIFT_PATH_TO_CMARK_SOURCE="%swift_source_dir%/cmark"^
 -DSWIFT_PATH_TO_CMARK_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/cmark-windows-amd64"^
 -DSWIFT_CMARK_LIBRARY_DIR="%swift_source_dir%/build/Ninja-DebugAssert/cmark-windows-amd64/src"^
 -DSWIFT_PATH_TO_LLVM_SOURCE="%swift_source_dir%/llvm"^
 -DSWIFT_PATH_TO_LLVM_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"^
 -DSWIFT_PATH_TO_CLANG_SOURCE="%swift_source_dir%/llvm/tools/clang"^
 -DSWIFT_PATH_TO_CLANG_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"^
 -DICU_UC_INCLUDE_DIR="%swift_source_dir%/icu/include"^
 -DICU_UC_LIBRARY_DIRS="%swift_source_dir%/icu/lib64"^
 -DICU_I18N_INCLUDE_DIR="%swift_source_dir%/icu/include"^
 -DICU_I18N_LIBRARY_DIRS="%swift_source_dir%/icu/lib64"^
 -DICU_UC_LIB_NAME="icuuc"^
 -DICU_I18N_LIB_NAME="icuin"^
 -DSWIFT_INCLUDE_DOCS=FALSE^
 -DSWIFT_INCLUDE_TESTS=FALSE^
 -DCMAKE_C_COMPILER="%llvm_bin_dir%/clang-cl.exe"^
 -DCMAKE_CXX_COMPILER="%llvm_bin_dir%/clang-cl.exe"^
 -DCMAKE_C_FLAGS="-fms-compatibility-version=19.00 /Z7"^
 -DCMAKE_CXX_FLAGS="-fms-compatibility-version=19.00 -Z7"^
 -DCMAKE_EXE_LINKER_FLAGS:STRING="/INCREMENTAL:NO"^
 -DCMAKE_MODULE_LINKER_FLAGS="/INCREMENTAL:NO"^
 -DCMAKE_SHARED_LINKER_FLAGS="/INCREMENTAL:NO"^
 -DCMAKE_STATIC_LINKER_FLAGS="/INCREMENTAL:NO"^
 -DCMAKE_INSTALL_PREFIX="C:/Program Files (x86)/Swift"^
 -DSWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER=FALSE
popd
cmake --build "%swift_source_dir%/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 15" "%swift_source_dir%/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 "%swift_source_dir%/build/Ninja-DebugAssert/lldb-windows-amd64"
pushd "%swift_source_dir%/build/Ninja-DebugAssert/lldb-windows-amd64"
cmake -G "Ninja" "%swift_source_dir%/lldb"^
  -DCMAKE_BUILD_TYPE=Debug^
  -DLLDB_PATH_TO_CMARK_SOURCE="%swift_source_dir%/cmark"^
  -DLLDB_PATH_TO_CMARK_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/cmark-windows-amd64"^
  -DLLDB_PATH_TO_LLVM_SOURCE="%swift_source_dir%/llvm"^
  -DLLDB_PATH_TO_LLVM_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"^
  -DLLDB_PATH_TO_CLANG_SOURCE="%swift_source_dir%/clang"^
  -DLLDB_PATH_TO_CLANG_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/llvm-windows-amd64"^
  -DLLDB_PATH_TO_SWIFT_SOURCE="%swift_source_dir%/swift"^
  -DLLDB_PATH_TO_SWIFT_BUILD="%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"^
  -DCMAKE_C_COMPILER="%llvm_bin_dir%/clang-cl.exe"^
  -DCMAKE_CXX_COMPILER="%llvm_bin_dir%/clang-cl.exe"^
  -DCMAKE_C_FLAGS="-fms-compatibility-version=19.00 /Z7"^
  -DCMAKE_CXX_FLAGS="-fms-compatibility-version=19.00 -Z7 -Wno-c++98-compat"^
  -DLLVM_ENABLE_ASSERTIONS=YES
popd
cmake --build "%swift_source_dir%/build/Ninja-RelWithDebInfoAssert/lldb-windows-amd64"

9. Install Swift on Windows

• Run ninja install:

pushd "%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"
ninja install
popd

• Add the Swift on Windows binaries path (C:\Program Files (x86)\Swift\bin) to the Path environment variable.
• Add the Swift on Windows library path (C:\Program Files (x86)\Swift\lib\swift\windows) to the Path environment variable.

MSVC

Follow instructions 1-6 for clang-cl, but run the following instead to build Swift

mkdir "%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"
pushd "%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"
cmake -G "Ninja" "%swift_source_dir%/swift"^
 -DCMAKE_BUILD_TYPE=Debug^
 -DSWIFT_PATH_TO_CMARK_SOURCE="%swift_source_dir%/cmark"^
 -DSWIFT_PATH_TO_CMARK_BUILD="%swift_source_dir%/build/Ninja-RelWithDebInfoAssert/cmark-windows-amd64"^
 -DSWIFT_CMARK_LIBRARY_DIR="%swift_source_dir%/build/Ninja-RelWithDebInfoAssert/cmark-windows-amd64/src"^
 -DSWIFT_PATH_TO_LLVM_SOURCE="%swift_source_dir%/llvm"^
 -DSWIFT_PATH_TO_LLVM_BUILD="%swift_source_dir%/build/Ninja-RelWithDebInfoAssert/llvm-windows-amd64"^
 -DSWIFT_PATH_TO_CLANG_SOURCE="%swift_source_dir%/llvm/tools/clang"^
 -DSWIFT_PATH_TO_CLANG_BUILD="%swift_source_dir%/build/Ninja-RelWithDebInfoAssert/llvm-windows-amd64"^
 -DICU_UC_INCLUDE_DIRS="%swift_source_dir%/icu/include"^
 -DICU_UC_LIBRARY_DIRS="%swift_source_dir%/icu/lib64"^
 -DICU_I18N_INCLUDE_DIRS="%swift_source_dir%/icu/include"^
 -DICU_I18N_LIBRARY_DIRS="%swift_source_dir%/icu/lib64"^
 -DICU_UC_LIB_NAME="icuuc"^
 -DICU_I18N_LIB_NAME="icuin"^
 -DSWIFT_INCLUDE_DOCS=FALSE^
 -DSWIFT_INCLUDE_TESTS=FALSE^
 -DSWIFT_BUILD_DYNAMIC_SDK_OVERLAY=FALSE^
 -DSWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER=FALSE
popd
cmake --build "%swift_source_dir%/build/Ninja-DebugAssert/swift-windows-amd64"