Configuring your compiler

Picking a Compiler

Depending on what platform(s) you want to target for your Minecraft: Bedrock Edition mod, you'll have to use the correct compiler and standard template library (STL) for complete ABI compatibility for both language features and library features.

The following table serves as a rough guide for which compiler you'll want to use for a given Bedrock platform. It's not exact, nor complete (for now):

Platform	Compiler	STL
Windows	MSVC	Microsoft STL
Android	GCC	libstdc++
OSX/iOS	Clang	libc++

Generally, it should be fine to use the latest releases of both the compiler and STL provided by the table. If any notable incompatibilities are found in the future, the table will be updated accordingly.

IMPORTANT

If you are targeting Windows, the correct runtime library must be configured, continue reading.

Setting the Runtime Library

When targeting Windows, STL container ABI and C Runtime function compatibility are affected by the runtime library being used (either Release or Debug). Since official Minecraft: Bedrock Edition releases are compiled with the Release mode libraries, your mod must use the Release mode libraries, even when compiling a debug build.

CMake

CMake 3.15 introduced the MSVC_RUNTIME_LIBRARY property. There are 2 relevant values:

MultiThreaded - Statically linked, release mode runtime library
MultiThreadedDLL - Dynamically linked, release mode runtime library

Opting for the dynamically linked runtime library will require users of your mod to have the associated Visual C++ Redistributable downloaded, in exchange for a smaller binary size. The inverse is true of the statically linked runtime library.

It is often faster to compile against the dynamically linked runtime library, so it's worth considering dynamic linkage for debug builds and static linkage for release builds. A CMake generator expression can facilitate this behavior:

CMake

set_property(TARGET MyTarget PROPERTY
    # Statically link in release mode and dynamically link in debug mode
    MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:DLL>")

Or if you only want to use one runtime library for all build types:

StaticDynamic

CMake

set_property(TARGET MyTarget PROPERTY
    MSVC_RUNTIME_LIBRARY "MultiThreaded")

CMake

set_property(TARGET MyTarget PROPERTY
    MSVC_RUNTIME_LIBRARY "MultiThreadedDLL")

Clang on Windows

IMPORTANT

Some modding platforms, such as Amethyst, do not support Clang.

The Clang compiler supports ABI compatibility with MSVC. While it is not fully compatible, it is in a state that is acceptable for most applications, including developing mods for Minecraft: Bedrock Edition.

This is best done through the clang-cl.exe driver program, which is a "drop-in" replacement for MSVC's cl.exe.

Incompatibilities

A common issue that is encountered when using Clang instead of MSVC is the incompatibility with entt::type_hash. To address this issue, see Type Hashes.

Downloading LLVM

Open the Visual Studio Installer and select "Modify" on your installation.

vs installer modify

Click on "Individual Components" at the top and search for "LLVM". Make sure that both "C++ Clang Compiler for Windows" and "MSBuild support for LLVM" are selected.

vs installer llvm