MSVC 编译器中的 /Fx 选项是什么意思？

Question

In the MSVC compiler, there is the option /Fx which generates merged source files. However, on the documentation of the option, there is no information about how to inject code into my source files nor what is the purpose of doing it.

If I take a dummy C++ project and add the /Fx option, nothing changes, no .mrg file is generated:

> cl.exe /c test.cpp /Fx

I have found no example of a usage of this option. I didn't find anything about code injection either.

So, how to inject code into a source file? What is the purpose of this feature?

Answer 1

I found https://assets.ctfassets.net/9pcn2syx7zns/524v1rKJCe8GHLT3OE8nso/0c198e1ab4059da9cd902f120defa4b5/c__.pdf which, on page 198, explains that this is for attributes . (emphasis mine)

Basic Mechanics of Attributes Microsoft defines a set of C++ attributes that simplify COM programming and .NET Framework common language runtime development. When you include attributes in your source files, the compiler works with provider DLLs to insert code or modify the code in the generated object files. These attributes aid in the creation of .idl files, interfaces, type libraries,and other COM elements.