According to the source code(UE4.26.2)
// Engine/Source/Runtime/Core/Public/Misc/CoreMiscDefines.h
#if UE_BUILD_DEBUG
#define FORCEINLINE_DEBUGGABLE FORCEINLINE_DEBUGGABLE_ACTUAL
#else
#define FORCEINLINE_DEBUGGABLE FORCEINLINE
#endif
// Engine/Source/Runtime/Core/Public/HAL/Platform.h
#ifndef FORCEINLINE_DEBUGGABLE_ACTUAL
#define FORCEINLINE_DEBUGGABLE_ACTUAL inline
#endif
// Engine/Source/Runtime/Core/Public/Windows/WIndowsPlatform.h
#define FORCEINLINE __forceinline /* Force code to be inline */
So I don’t understand how the macro FORCEINLINE_DEBUGGABLE can make a function inlined but also debuggable.