Should C# plugin(win) be a single cspomelo.dll instead of two DLLs (cspomelo.dll and libpomelo2.dll) ? #49

I try to complie the unity plugin,and thought that a single cspomelo.dll maybe the common ways for unity plugins.
And in my vs2015, multiple DLLS way do not work yet
'''
gyp --depth=. pomelo.gyp -Dbuild_cspomelo=true -Dpomelo_library=shared_library
'''
failed with some link errors.

I thought the best command to indicate to generate a DLL for c# plugin should simply like this (and it generate a single dll )
'''
gyp --depth=. pomelo.gyp -Dbuild_cspomelo=true
'''
But there are some problems for me:VS-PRB: Can't Export from Static Libraries
To export functions to DLL from static library in VC .
It must ,either recomplie static library with __declspec(dllexport) for all the functions to be exported ,or write a handy .def files to export.

So how can i make gpy to generate the right sln automatically? i saw the pomelo.gyp file,but cause i did not know gyp before,so i have no clue.
(
Things i want to do is that
define BUILDING_PC_SHARED in project <libpomelo2> automatically
by command gyp --depth=. pomelo.gyp -Dbuild_cspomelo=true,
so the static library libpomelo2.lib will be compiled with __declspec(dllexport)
).