Preprocessor commands

cl -help

cl .\Compilation.cpp /E

cl .\Compilation.cpp /P

cl .\Compilation.cpp /P /DCONFIG

cl .\Compilation.cpp /P /DCONFIG=102

cl .\Compilation.cpp /P /EP /C

cl .\Compilation.cpp /P /Fimy_cool_preprocessor.i

using UnrealBuildTool;

public class Compilation : ModuleRules
{
    public Compilation(ReadOnlyTargetRules Target) : base(Target)
    {
        PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
        PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "EnhancedInput" });

        PublicDefinitions.Add("CONFIG=102");
    }
}