Is there STDCALL in Linux?

I'm trying to port a Windows app to Linux. This appplication marks some functions with the __stdcall attribute. However, I was told by a friend that stdcall is used only on Windows and has no meaning in Linux (but DOES exist in Windows GCC).

Searching Google - some results state that there IS stdcall in Linux.

Is there a stdcall in Linux?

Additionally, GCC indicates that: __attribute__((__stdcall__)) and __attribute__((stdcall)) (without the underscores near stdcall).

Which one is preferred (if applied to Linux at all)?

The simplest solution is to just define __stdcall to nothing conditionally on Linux.