C# MethodSymbol.IsAccessor方法代码示例

        /// <summary>
        /// Rewrites arguments of an invocation according to the receiving method or indexer.
        /// It is assumed that each argument has already been lowered, but we may need
        /// additional rewriting for the arguments, such as generating a params array, re-ordering
        /// arguments based on <paramref name="argsToParamsOpt"/> map, inserting arguments for optional parameters, etc.
        /// <paramref name="optionalParametersMethod"/> is the method used for values of any optional parameters.
        /// For indexers, this method must be an accessor, and for methods it must be the method
        /// itself. <paramref name="optionalParametersMethod"/> is needed for indexers since getter and setter
        /// may have distinct optional parameter values.
        /// </summary>
        private ImmutableArray<BoundExpression> MakeArguments(
            SyntaxNode syntax,
            ImmutableArray<BoundExpression> rewrittenArguments,
            Symbol methodOrIndexer,
            MethodSymbol optionalParametersMethod,
            bool expanded,
            ImmutableArray<int> argsToParamsOpt,
            ref ImmutableArray<RefKind> argumentRefKindsOpt,
            out ImmutableArray<LocalSymbol> temps,
            bool invokedAsExtensionMethod = false,
            ThreeState enableCallerInfo = ThreeState.Unknown)
        {
            // Either the methodOrIndexer is a property, in which case the method used
            // for optional parameters is an accessor of that property (or an overridden
            // property), or the methodOrIndexer is used for optional parameters directly.
            Debug.Assert(((methodOrIndexer.Kind == SymbolKind.Property) && optionalParametersMethod.IsAccessor()) ||
                ReferenceEquals(methodOrIndexer, optionalParametersMethod));

            // We need to do a fancy rewrite under the following circumstances:
            // (1) a params array is being used; we need to generate the array.
            // (2) there were named arguments that reordered the arguments; we might
            //     have to generate temporaries to ensure that the arguments are 
            //     evaluated in source code order, not the actual call order.
            // (3) there were optional parameters that had no corresponding arguments.
            //
            // If none of those are the case then we can just take an early out.

            // An applicable "vararg" method could not possibly be applicable in its expanded
            // form, and cannot possibly have named arguments or used optional parameters, 
            // because the __arglist() argument has to be positional and in the last position. 


            if (methodOrIndexer.GetIsVararg())
            {
                Debug.Assert(rewrittenArguments.Length == methodOrIndexer.GetParameterCount() + 1);
                Debug.Assert(argsToParamsOpt.IsDefault);
                Debug.Assert(!expanded);
                temps = default(ImmutableArray<LocalSymbol>);
                return rewrittenArguments;
            }

            var receiverNamedType = invokedAsExtensionMethod ?
                                    ((MethodSymbol)methodOrIndexer).Parameters[0].Type as NamedTypeSymbol :
                                    methodOrIndexer.ContainingType;

            bool isComReceiver = (object)receiverNamedType != null && receiverNamedType.IsComImport;

            if (rewrittenArguments.Length == methodOrIndexer.GetParameterCount() &&
                argsToParamsOpt.IsDefault &&
                !expanded &&
                !isComReceiver)
            {
                temps = default(ImmutableArray<LocalSymbol>);
                return rewrittenArguments;
            }


            // We have:
            // * a list of arguments, already converted to their proper types, 
            //   in source code order. Some optional arguments might be missing.
            // * a map showing which parameter each argument corresponds to. If
            //   this is null, then the argument to parameter mapping is one-to-one.
            // * the ref kind of each argument, in source code order. That is, whether
            //   the argument was marked as ref, out, or value (neither).
            // * a method symbol.
            // * whether the call is expanded or normal form.

            // We rewrite the call so that:
            // * if in its expanded form, we create the params array.
            // * if the call requires reordering of arguments because of named arguments, temporaries are generated as needed

            // Doing this transformation can move around refness in interesting ways. For example, consider
            //
            // A().M(y : ref B()[C()], x : out D());
            //
            // This will be created as a call with receiver A(), symbol M, argument list ( B()[C()], D() ),
            // name list ( y, x ) and ref list ( ref, out ).  We can rewrite this into temporaries:
            //
            // A().M( 
            //    seq ( ref int temp_y = ref B()[C()], out D() ),
            //    temp_y );
            // 
            // Now we have a call with receiver A(), symbol M, argument list as shown, no name list,
            // and ref list ( out, value ). We do not want to pass a *ref* to temp_y; the temporary
            // storage is not the thing being ref'd! We want to pass the *value* of temp_y, which
            // *contains* a reference.

            // We attempt to minimize the number of temporaries required. Arguments which neither
            // produce nor observe a side effect can be placed into their proper position without
            // recourse to a temporary. For example:
//.........这里部分代码省略.........

        public override void VisitMethod(MethodSymbol symbol)
        {
            _cancellationToken.ThrowIfCancellationRequested();

            if (DoNotVisit(symbol)) return;

            Compliance compliance = GetDeclaredOrInheritedCompliance(symbol);

            // Most CLS checks don't apply to accessors.
            if (symbol.IsAccessor())
            {
                CheckForAttributeOnAccessor(symbol);
                CheckForMeaninglessOnParameter(symbol.Parameters);
                CheckForMeaninglessOnReturn(symbol);

                if (IsTrue(compliance))
                {
                    CheckForAttributeWithArrayArgument(symbol);
                }

                return;
            }

            if (!VisitTypeOrMember(symbol, compliance)) return;

            if (IsTrue(compliance))
            {
                CheckParameterCompliance(symbol.Parameters, symbol.ContainingType);
                CheckTypeParameterCompliance(symbol.TypeParameters, symbol.ContainingType);

                if (symbol.IsVararg)
                {
                    this.AddDiagnostic(ErrorCode.WRN_CLS_NoVarArgs, symbol.Locations[0]);
                }
            }
        }