// Add the second result type, if any.
		if twoResults {
			if name.FuncType.Result == nil {
				// An explicit void result looks odd but it
				// seems to be how cgo has worked historically.
				sb.WriteString("_Ctype_void")
			}
			sb.WriteString(", error)")
		}
	}

	sb.WriteString("{ ")

	// Define _cgoN for each argument value.
	// Write _cgoCheckPointer calls to sbCheck.
	var sbCheck bytes.Buffer

or variables, are provided in _cgo_gotypes.go.

Here is a _cgo_gotypes.go containing definitions for needed C types:

	type _Ctype_char int8
	type _Ctype_int int32
	type _Ctype_void [0]byte

The _cgo_gotypes.go file also contains the definitions of the
functions. They all have similar bodies that invoke runtime·cgocall
to make a switch from the Go runtime world to the system C (GCC-based)
world.