Except, in the Cygwin ecosystem, it doesn't look as if you can do that. All the "crt" stuff for setting up the executable environment is built around regular main.
Luckily, I maintain a fork of the Cygwin DLL for my project called Cygnal, where I can make improvements. The focus has not been security up to now, but rather restoring some "native like" behaviors in the Cygwin run-time that are "too POSIXy" for native Windows users.
I could hack the CRT stuff in the Cygnal fork to avoid pitfalls in producing the main() arguments.
At the moment, I only looked at this issue fairly superficially, so I don't have a full picture of how what piece are doing exactly what in this area.
The above guess turns out to be false. You can link a program in Cygwin that has WinMain.
If you don't include <windows.h>, you can give it whatever argument list you like, such as (void), and it will work. But in 32 bit Cygwin (which I still support), it will complain about _WinMain@16 missing (as a warning only).
If you give it the correct signature declared in <winbase.h> then it links on 32 or 64 bit Cygwin just fine. without warnings.
In this WinMain, you can use the wide-string functions for obtaining the command line and parsing to arguments.
