Use Clang to Build Microsoft Platforms

Unreal Engine (UE) supports using the Clang compiler on Windows to build supported Microsoft platforms. You can enable Clang with:

• Build Configuration
• Command-Line Arguments
• Engine Configuration

This page also includes a table of additional options, such as specifying:

• Clang linker
• Clang version
• MSVC version
• Toolchain version

For more information, see the Additional Options section below. As of UE 5.3, the latest supported version of Clang is Clang 16.

What is Clang

Clang is a front-end compiler that compiles C, C++, Objective-C, and Objective-C++ into machine code. Clang is an alternative to the MSVC (Microsoft Visual C++) compiler.

Install Clang

You can install Clang through Visual Studio or directly from the LLVM Downloads page.

Enable Clang

Once you have installed Clang, follow any one of the methods below to enable Clang in your Unreal project.

Build Configuration

To enable Clang in Build Configuration, navigate to an engine BuildConfiguration.xml file, and add the following:

<?xml version="1.0" encoding="utf-8" ?>
<Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">
	...
	<WindowsPlatform>
      		<Compiler>Clang</Compiler>
	</WindowsPlatform>
...
</Configuration>
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<?xml version="1.0" encoding="utf-8" ?> <Configuration xmlns="https://www.unrealengine.com/BuildConfiguration"> ... <WindowsPlatform> <Compiler>Clang</Compiler> </WindowsPlatform> ... </Configuration>

Command-Line Arguments

To enable Clang with Command-Line Arguments, pass the -Compiler=Clang option.

Engine Configuration

To enable Clang in Engine Configuration, navigate to an engine configuration file, such as DefaultEngine.ini, and add the following:

[/Script/WindowsTargetPlatform.WindowsTargetSettings]
CompilerVersion=Clang
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[/Script/WindowsTargetPlatform.WindowsTargetSettings] CompilerVersion=Clang

Additional Options

The following options assume that:

• Build Configuration options are added inside the <WindowsPlatform>...</WindowsPlatform> section of BuildConfiguration.xml.
• Engine Configuration options are added to the [/Script/WindowsTargetPlatform.WindowsTargetSettings] section of an engine configuration file, such as DefaultEngine.ini.

Clang Linker

The Clang Linker is a boolean option that determines whether the Clang Linker is used when compiling with Clang.

Epic does not use the Clang linker for Microsoft platforms and it is not currently tested.

Clang Compiler Version

The Clang compiler version is a string option that determines which version of the specified compiler is used. The options include:

• Specific version number: Use the exact version specified, for example, "16.0.0".
• Latest: Use the newest installed version.

MSVC Version

The MSVC Toolchain is a string option that determines which toolchain is used. The options include:

• VisualStudio2022
• VisualStudio2019

Toolchain Version

The Toolchain version is a string option that determines which version of the MSVC toolchain is used. The options include:

• Specific version number: Use the exact version specified, for example, "14.37.32822".
• Latest: Use the newest installed version.
• Preview: Use the newest installed preview version.

More Information

Follow these links for information about:

• Windows Platform section of Build Configuration
• Command-Line Arguments
• Engine Configuration Files