how does a c sharp compiler work when a function from the system namespace is called?

how does a c sharp compiler work when a function from any pre-defined namespace is called? I have mentioned System namespace just a开发者_如何学运维s an instance.

The same as it does for any other namespace. There is no magic here.

There are some hard-coded things in the compiler, for example:

• the type aliases int/string etc which are merely aliases to global::System.Int32 etc
• the expression tree compiler is, AFAIK, hard-coded to System.Linq.Expressions.Expression (but is also not cited in the spec, so a bit of an edge-case)
• some magic in the interop namespaces (for calling constructors on interfaces, etc)

But mostly... it is just classes etc.