vcpkg/docs/users/triplets.md

Triplet files

Triplet is a standard term used in cross compiling as a way to completely capture the target environment (cpu, os, compiler, runtime, etc) in a single convenient name.

In Vcpkg, we use triplets to describe self-consistent builds of library sets. This means every library will be built using the same target cpu, OS, and compiler toolchain, but also CRT linkage and preferred library type.

We currently provide many triplets by default (run vcpkg help triplet). However, you can easily add your own by creating a new file in the triplets\ directory. The new triplet will immediately be available for use in commands, such as vcpkg install boost:x86-windows-custom.

To change the triplet used by your project, such as to enable static linking, see our Integration Document.

Variables

VCPKG_TARGET_ARCHITECTURE

Specifies the target machine architecture.

Valid options are x86, x64, arm, and arm64.

VCPKG_CRT_LINKAGE

Specifies the desired CRT linkage (for MSVC).

Valid options are dynamic and static.

VCPKG_LIBRARY_LINKAGE

Specifies the preferred library linkage.

Valid options are dynamic and static. Note that libraries can ignore this setting if they do not support the preferred linkage type.

VCPKG_CMAKE_SYSTEM_NAME

Specifies the target platform.

Valid options include any CMake system name, such as:

• Empty (Windows Desktop for legacy reasons)
• WindowsStore (Universal Windows Platform)
• Darwin (Mac OSX)
• Linux (Linux)

VCPKG_CHAINLOAD_TOOLCHAIN_FILE

Specifies an alternate CMake Toolchain file to use.

This (if set) will override all other compiler detection logic. By default, a toolchain file is selected from scripts/toolchains/ appropriate to the platform.

See also the CMake documentation for toolchain files: https://cmake.org/cmake/help/v3.11/manual/cmake-toolchains.7.html.

VCPKG_CXX_FLAGS

Sets additional compiler flags to be used when not using VCPKG_CHAINLOAD_TOOLCHAIN_FILE.

This option also has forms for configuration-specific and C flags:

• VCPKG_CXX_FLAGS
• VCPKG_CXX_FLAGS_DEBUG
• VCPKG_CXX_FLAGS_RELEASE
• VCPKG_C_FLAGS
• VCPKG_C_FLAGS_DEBUG
• VCPKG_C_FLAGS_RELEASE

Windows Variables

VCPKG_VISUAL_STUDIO_PATH

Specifies the Visual Studio installation to use.

To select the precise combination of Visual Studio instance and toolset version, we walk through the following algorithm:

1. Determine the setting for VCPKG_VISUAL_STUDIO_PATH from the triplet, or the environment variable VCPKG_VISUAL_STUDIO_PATH, or consider it unset
2. Determine the setting for VCPKG_PLATFORM_TOOLSET from the triplet or consider it unset
3. Gather a list of all pairs of Visual Studio Instances with all toolsets available in those instances
   1. This is ordered first by instance type (Stable, Prerelease, Legacy) and then by toolset version (v142, v141, v140)
4. Filter the list based on the settings for VCPKG_VISUAL_STUDIO_PATH and VCPKG_PLATFORM_TOOLSET.
5. Select the best remaining option

The path should be absolute, formatted with backslashes, and have no trailing slash:

set(VCPKG_VISUAL_STUDIO_PATH "C:\\Program Files (x86)\\Microsoft Visual Studio\\Preview\\Community")

VCPKG_PLATFORM_TOOLSET

Specifies the VS-based C/C++ compiler toolchain to use.

See VCPKG_VISUAL_STUDIO_PATH for the full selection algorithm.

Valid settings:

• The Visual Studio 2019 platform toolset is v142.
• The Visual Studio 2017 platform toolset is v141.
• The Visual Studio 2015 platform toolset is v140.

MacOS Variables

VCPKG_INSTALL_NAME_DIR

Sets the install name used when building macOS dynamic libraries. Default value is @rpath. See the CMake documentation for CMAKE_INSTALL_NAME_DIR for more information.

VCPKG_OSX_DEPLOYMENT_TARGET

Sets the minimum macOS version for compiled binaries. This also changes what versions of the macOS platform SDK that CMake will search for. See the CMake documentation for CMAKE_OSX_DEPLOYMENT_TARGET for more information.

VCPKG_OSX_SYSROOT

Set the name or path of the macOS platform SDK that will be used by CMake. See the CMake documentation for CMAKE_OSX_SYSROOT for more information.

Per-port customization

The CMake Macro PORT will be set when interpreting the triplet file and can be used to change settings (such as VCPKG_LIBRARY_LINKAGE) on a per-port basis.

Example:

set(VCPKG_LIBRARY_LINKAGE static)
if(PORT MATCHES "qt5-")
    set(VCPKG_LIBRARY_LINKAGE dynamic)
endif()

This will build all the qt5-* libraries as DLLs, but every other library as a static library.

For an example in a real project, see https://github.com/Intelight/vcpkg/blob/master/triplets/x86-windows-mixed.cmake.

Additional Remarks

The default triplet when running any vcpkg command is %VCPKG_DEFAULT_TRIPLET% or a platform-specific choice if that environment variable is undefined.

• Windows: x86-windows
• Linux: x64-linux
• OSX: x64-osx

We recommend using a systematic naming scheme when creating new triplets. The Android toolchain naming scheme is a good source of inspiration: https://developer.android.com/ndk/guides/standalone_toolchain.html.