Mono.CSharp.CompoundAssign.DoResolve C# (CSharp) Method

		protected override Expression DoResolve (ResolveContext ec)
		{
			right = right.Resolve (ec);
			if (right == null)
				return null;

			MemberAccess ma = target as MemberAccess;
			using (ec.Set (ResolveContext.Options.CompoundAssignmentScope)) {
				target = target.Resolve (ec);
			}
			
			if (target == null)
				return null;

			if (target is MethodGroupExpr){
				ec.Report.Error (1656, loc,
					"Cannot assign to `{0}' because it is a `{1}'",
					((MethodGroupExpr)target).Name, target.ExprClassName);
				return null;
			}

			var event_expr = target as EventExpr;
			if (event_expr != null) {
				source = Convert.ImplicitConversionRequired (ec, right, target.Type, loc);
				if (source == null)
					return null;

				Expression rside;
				if (op == Binary.Operator.Addition)
					rside = EmptyExpression.EventAddition;
				else if (op == Binary.Operator.Subtraction)
					rside = EmptyExpression.EventSubtraction;
				else
					rside = null;

				target = target.ResolveLValue (ec, rside);
				if (target == null)
					return null;

				eclass = ExprClass.Value;
				type = event_expr.Operator.ReturnType;
				return this;
			}

			//
			// Only now we can decouple the original source/target
			// into a tree, to guarantee that we do not have side
			// effects.
			//
			if (left == null)
				left = new TargetExpression (target);

			source = new Binary (op, left, right, true, loc);

			if (target is DynamicMemberAssignable) {
				Arguments targs = ((DynamicMemberAssignable) target).Arguments;
				source = source.Resolve (ec);

				Arguments args = new Arguments (targs.Count + 1);
				args.AddRange (targs);
				args.Add (new Argument (source));

				var binder_flags = CSharpBinderFlags.ValueFromCompoundAssignment;

				//
				// Compound assignment does target conversion using additional method
				// call, set checked context as the binary operation can overflow
				//
				if (ec.HasSet (ResolveContext.Options.CheckedScope))
					binder_flags |= CSharpBinderFlags.CheckedContext;

				if (target is DynamicMemberBinder) {
					source = new DynamicMemberBinder (ma.Name, binder_flags, args, loc).Resolve (ec);

					// Handles possible event addition/subtraction
					if (op == Binary.Operator.Addition || op == Binary.Operator.Subtraction) {
						args = new Arguments (targs.Count + 1);
						args.AddRange (targs);
						args.Add (new Argument (right));
						string method_prefix = op == Binary.Operator.Addition ?
							Event.AEventAccessor.AddPrefix : Event.AEventAccessor.RemovePrefix;

						var invoke = DynamicInvocation.CreateSpecialNameInvoke (
							new MemberAccess (right, method_prefix + ma.Name, loc), args, loc).Resolve (ec);

						args = new Arguments (targs.Count);
						args.AddRange (targs);
						source = new DynamicEventCompoundAssign (ma.Name, args,
							(ExpressionStatement) source, (ExpressionStatement) invoke, loc).Resolve (ec);
					}
				} else {
					source = new DynamicIndexBinder (binder_flags, args, loc).Resolve (ec);
				}

				return source;
			}

			return base.DoResolve (ec);
		}