Build.cs

The Build.cs C# code is attached to each module and defines how the code for each module is built. There are many variables in this class that users can take advantage of to compile code conditionally per different build situation or set up a special types of modules.

UnrealBuildTool specification

Target

You can use Target to get to a lot of the properties of the build's target settings, such as platform or type of build being compiled.

Configuration

Example:

if(Target.Configuration == UnrealTargetConfiguration.Shipping)
{
      ...
}

Options: (from Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildTarget.cs)

public enum UnrealTargetConfiguration
{
    Unknown,
    Debug,
    DebugGame,
    Development,
    Shipping,
    Test
}

Platform

Example:

if(Target.Platform == UnrealTargetPlatform.Win64)
{
      ...
}

Options: (from Engine/Source/Programs/UnrealBuildTool/Configuration/UEBuildTarget.cs)

public static UnrealTargetPlatform Win32 = FindOrAddByName("Win32");
public static UnrealTargetPlatform Win64 = FindOrAddByName("Win64");
public static UnrealTargetPlatform HoloLens = FindOrAddByName("HoloLens");
public static UnrealTargetPlatform Mac = FindOrAddByName("Mac");
public static UnrealTargetPlatform XboxOne = FindOrAddByName("XboxOne");
public static UnrealTargetPlatform PS4 = FindOrAddByName("PS4");
public static UnrealTargetPlatform IOS = FindOrAddByName("IOS");
public static UnrealTargetPlatform Android = FindOrAddByName("Android");
public static UnrealTargetPlatform Linux = FindOrAddByName("Linux");
public static UnrealTargetPlatform LinuxAArch64 = FindOrAddByName("LinuxAArch64");
public static UnrealTargetPlatform AllDesktop = FindOrAddByName("AllDesktop");
public static UnrealTargetPlatform TVOS = FindOrAddByName("TVOS");
public static UnrealTargetPlatform Switch = FindOrAddByName("Switch");
public static UnrealTargetPlatform Quail = FindOrAddByName("Quail");
public static UnrealTargetPlatform Lumin = FindOrAddByName("Lumin");