Mono.CSharp.EventField.EventFieldAccessor.FabricateBodyStatement C# (CSharp) Method

            void FabricateBodyStatement()
            {
                var cas = TypeManager.gen_interlocked_compare_exchange;
                if (cas == null) {
                    var t = Module.PredefinedTypes.Interlocked.Resolve (Location);
                    if (t == null)
                        return;

                    var p = new ParametersImported (
                        new[] {
                                new ParameterData (null, Parameter.Modifier.REF),
                                new ParameterData (null, Parameter.Modifier.NONE),
                                new ParameterData (null, Parameter.Modifier.NONE)
                            },
                        new[] {
                                new TypeParameterSpec (0, null, SpecialConstraint.None, Variance.None, null),
                                new TypeParameterSpec (0, null, SpecialConstraint.None, Variance.None, null),
                                new TypeParameterSpec (0, null, SpecialConstraint.None, Variance.None, null),
                            }, false);

                    var filter = new MemberFilter ("CompareExchange", 1, MemberKind.Method, p, null);
                    cas = TypeManager.gen_interlocked_compare_exchange = TypeManager.GetPredefinedMethod (t, filter, Location);
                }

                //
                // Delegate obj1 = backing_field
                // do {
                //   Delegate obj2 = obj1;
                //   obj1 =	Interlocked.CompareExchange (ref backing_field, Delegate.Combine|Remove(obj2, value), obj1);
                // } while (obj1 != obj2)
                //

                var field_info = ((EventField) method).backing_field;
                FieldExpr f_expr = new FieldExpr (field_info, Location);
                if (!IsStatic)
                    f_expr.InstanceExpression = new CompilerGeneratedThis (Parent.CurrentType, Location);

                var obj1 = LocalVariable.CreateCompilerGenerated (field_info.MemberType, block, Location);
                var obj2 = LocalVariable.CreateCompilerGenerated (field_info.MemberType, block, Location);

                block.AddStatement (new StatementExpression (new SimpleAssign (new LocalVariableReference (obj1, Location), f_expr)));

                var cond = new BooleanExpression (new Binary (Binary.Operator.Inequality,
                    new LocalVariableReference (obj1, Location), new LocalVariableReference (obj2, Location), Location));

                var body = new ExplicitBlock (block, Location, Location);
                block.AddStatement (new Do (body, cond, Location));

                body.AddStatement (new StatementExpression (
                    new SimpleAssign (new LocalVariableReference (obj2, Location), new LocalVariableReference (obj1, Location))));

                var args_oper = new Arguments (2);
                args_oper.Add (new Argument (new LocalVariableReference (obj2, Location)));
                args_oper.Add (new Argument (block.GetParameterReference (0, Location)));

                var args = new Arguments (3);
                args.Add (new Argument (f_expr, Argument.AType.Ref));
                args.Add (new Argument (new Cast (
                    new TypeExpression (field_info.MemberType, Location),
                    new Invocation (MethodGroupExpr.CreatePredefined (Operation, Operation.DeclaringType, Location), args_oper),
                    Location)));
                args.Add (new Argument (new LocalVariableReference (obj1, Location)));

                body.AddStatement (new StatementExpression (new SimpleAssign (
                    new LocalVariableReference (obj1, Location),
                    new Invocation (MethodGroupExpr.CreatePredefined (cas, cas.DeclaringType, Location), args))));
            }