2 // ecore.cs: Core of the Expression representation for the intermediate tree.
5 // Miguel de Icaza (miguel@ximian.com)
6 // Marek Safar (marek.safar@gmail.com)
8 // Copyright 2001, 2002, 2003 Ximian, Inc.
9 // Copyright 2003-2008 Novell, Inc.
10 // Copyright 2011-2012 Xamarin Inc.
15 using System.Collections.Generic;
17 using SLE = System.Linq.Expressions;
21 using IKVM.Reflection;
22 using IKVM.Reflection.Emit;
24 using System.Reflection;
25 using System.Reflection.Emit;
28 namespace Mono.CSharp {
31 /// The ExprClass class contains the is used to pass the
32 /// classification of an expression (value, variable, namespace,
33 /// type, method group, property access, event access, indexer access,
36 public enum ExprClass : byte {
52 /// This is used to tell Resolve in which types of expressions we're
56 public enum ResolveFlags {
57 // Returns Value, Variable, PropertyAccess, EventAccess or IndexerAccess.
60 // Returns a type expression.
63 // Returns a method group.
66 TypeParameter = 1 << 3,
68 // Mask of all the expression class flags.
69 MaskExprClass = VariableOrValue | Type | MethodGroup | TypeParameter,
73 // This is just as a hint to AddressOf of what will be done with the
76 public enum AddressOp {
83 /// This interface is implemented by variables
85 public interface IMemoryLocation {
87 /// The AddressOf method should generate code that loads
88 /// the address of the object and leaves it on the stack.
90 /// The `mode' argument is used to notify the expression
91 /// of whether this will be used to read from the address or
92 /// write to the address.
94 /// This is just a hint that can be used to provide good error
95 /// reporting, and should have no other side effects.
97 void AddressOf (EmitContext ec, AddressOp mode);
101 // An expressions resolved as a direct variable reference
103 public interface IVariableReference : IFixedExpression
105 bool IsHoisted { get; }
107 VariableInfo VariableInfo { get; }
109 void SetHasAddressTaken ();
113 // Implemented by an expression which could be or is always
116 public interface IFixedExpression
118 bool IsFixed { get; }
121 public interface IExpressionCleanup
123 void EmitCleanup (EmitContext ec);
127 /// Base class for expressions
129 public abstract class Expression
131 public ExprClass eclass;
132 protected TypeSpec type;
133 protected Location loc;
135 public TypeSpec Type {
137 set { type = value; }
140 public virtual bool IsSideEffectFree {
146 public Location Location {
150 public virtual bool IsNull {
157 // Used to workaround parser limitation where we cannot get
158 // start of statement expression location
160 public virtual Location StartLocation {
166 public virtual MethodGroupExpr CanReduceLambda (AnonymousMethodBody body)
169 // Return method-group expression when the expression can be used as
170 // lambda replacement. A good example is array sorting where instead of
173 // Array.Sort (s, (a, b) => String.Compare (a, b));
175 // we can use method group directly
177 // Array.Sort (s, String.Compare);
179 // Correct overload will be used because we do the reduction after
180 // best candidate was found.
186 // Returns true when the expression during Emit phase breaks stack
187 // by using await expression
189 public virtual bool ContainsEmitWithAwait ()
195 /// Performs semantic analysis on the Expression
199 /// The Resolve method is invoked to perform the semantic analysis
202 /// The return value is an expression (it can be the
203 /// same expression in some cases) or a new
204 /// expression that better represents this node.
206 /// For example, optimizations of Unary (LiteralInt)
207 /// would return a new LiteralInt with a negated
210 /// If there is an error during semantic analysis,
211 /// then an error should be reported (using Report)
212 /// and a null value should be returned.
214 /// There are two side effects expected from calling
215 /// Resolve(): the the field variable "eclass" should
216 /// be set to any value of the enumeration
217 /// `ExprClass' and the type variable should be set
218 /// to a valid type (this is the type of the
221 protected abstract Expression DoResolve (ResolveContext rc);
223 public virtual Expression DoResolveLValue (ResolveContext rc, Expression right_side)
229 // This is used if the expression should be resolved as a type or namespace name.
230 // the default implementation fails.
232 public virtual TypeSpec ResolveAsType (IMemberContext mc, bool allowUnboundTypeArguments = false)
234 var rc = mc as ResolveContext ?? new ResolveContext (mc);
235 Expression e = Resolve (rc);
237 e.Error_UnexpectedKind (rc, ResolveFlags.Type, loc);
242 public static void ErrorIsInaccesible (IMemberContext rc, string member, Location loc)
244 rc.Module.Compiler.Report.Error (122, loc, "`{0}' is inaccessible due to its protection level", member);
247 public void Error_ExpressionMustBeConstant (ResolveContext rc, Location loc, string e_name)
249 rc.Report.Error (133, loc, "The expression being assigned to `{0}' must be constant", e_name);
252 public void Error_ConstantCanBeInitializedWithNullOnly (ResolveContext rc, TypeSpec type, Location loc, string name)
254 rc.Report.Error (134, loc, "A constant `{0}' of reference type `{1}' can only be initialized with null",
255 name, type.GetSignatureForError ());
258 protected virtual void Error_InvalidExpressionStatement (Report report, Location loc)
260 report.Error (201, loc, "Only assignment, call, increment, decrement, await, and new object expressions can be used as a statement");
263 public void Error_InvalidExpressionStatement (BlockContext bc)
265 Error_InvalidExpressionStatement (bc.Report, loc);
268 public void Error_InvalidExpressionStatement (Report report)
270 Error_InvalidExpressionStatement (report, loc);
273 public static void Error_VoidInvalidInTheContext (Location loc, Report Report)
275 Report.Error (1547, loc, "Keyword `void' cannot be used in this context");
278 public virtual void Error_ValueCannotBeConverted (ResolveContext ec, TypeSpec target, bool expl)
280 Error_ValueCannotBeConvertedCore (ec, loc, target, expl);
283 protected void Error_ValueCannotBeConvertedCore (ResolveContext ec, Location loc, TypeSpec target, bool expl)
285 // The error was already reported as CS1660
286 if (type == InternalType.AnonymousMethod)
289 if (type == InternalType.ErrorType || target == InternalType.ErrorType)
292 if (type.MemberDefinition.DeclaringAssembly.IsMissing ||
293 target.MemberDefinition.DeclaringAssembly.IsMissing)
296 string from_type = type.GetSignatureForError ();
297 string to_type = target.GetSignatureForError ();
298 if (from_type == to_type) {
299 from_type = type.GetSignatureForErrorIncludingAssemblyName ();
300 to_type = target.GetSignatureForErrorIncludingAssemblyName ();
304 ec.Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
309 ec.Report.DisableReporting ();
310 bool expl_exists = Convert.ExplicitConversion (ec, this, target, Location.Null) != null;
311 ec.Report.EnableReporting ();
314 ec.Report.Error (266, loc,
315 "Cannot implicitly convert type `{0}' to `{1}'. An explicit conversion exists (are you missing a cast?)",
318 ec.Report.Error (29, loc, "Cannot implicitly convert type `{0}' to `{1}'",
323 public void Error_TypeArgumentsCannotBeUsed (IMemberContext context, MemberSpec member, Location loc)
325 // Better message for possible generic expressions
326 if (member != null && (member.Kind & MemberKind.GenericMask) != 0) {
327 var report = context.Module.Compiler.Report;
328 report.SymbolRelatedToPreviousError (member);
329 if (member is TypeSpec)
330 member = ((TypeSpec) member).GetDefinition ();
332 member = ((MethodSpec) member).GetGenericMethodDefinition ();
334 string name = member.Kind == MemberKind.Method ? "method" : "type";
335 if (member.IsGeneric) {
336 report.Error (305, loc, "Using the generic {0} `{1}' requires `{2}' type argument(s)",
337 name, member.GetSignatureForError (), member.Arity.ToString ());
339 report.Error (308, loc, "The non-generic {0} `{1}' cannot be used with the type arguments",
340 name, member.GetSignatureForError ());
343 Error_TypeArgumentsCannotBeUsed (context, ExprClassName, GetSignatureForError (), loc);
347 public static void Error_TypeArgumentsCannotBeUsed (IMemberContext context, string exprType, string name, Location loc)
349 context.Module.Compiler.Report.Error (307, loc, "The {0} `{1}' cannot be used with type arguments",
353 public virtual void Error_TypeDoesNotContainDefinition (ResolveContext ec, TypeSpec type, string name)
355 Error_TypeDoesNotContainDefinition (ec, loc, type, name);
358 public static void Error_TypeDoesNotContainDefinition (ResolveContext ec, Location loc, TypeSpec type, string name)
360 ec.Report.SymbolRelatedToPreviousError (type);
361 ec.Report.Error (117, loc, "`{0}' does not contain a definition for `{1}'",
362 type.GetSignatureForError (), name);
365 public virtual void Error_ValueAssignment (ResolveContext rc, Expression rhs)
367 if (rhs == EmptyExpression.LValueMemberAccess || rhs == EmptyExpression.LValueMemberOutAccess) {
368 // Already reported as CS1612
369 } else if (rhs == EmptyExpression.OutAccess) {
370 rc.Report.Error (1510, loc, "A ref or out argument must be an assignable variable");
372 rc.Report.Error (131, loc, "The left-hand side of an assignment must be a variable, a property or an indexer");
376 protected void Error_VoidPointerOperation (ResolveContext rc)
378 rc.Report.Error (242, loc, "The operation in question is undefined on void pointers");
381 public static void Warning_UnreachableExpression (ResolveContext rc, Location loc)
383 rc.Report.Warning (429, 4, loc, "Unreachable expression code detected");
386 public ResolveFlags ExprClassToResolveFlags {
390 case ExprClass.Namespace:
391 return ResolveFlags.Type;
393 case ExprClass.MethodGroup:
394 return ResolveFlags.MethodGroup;
396 case ExprClass.TypeParameter:
397 return ResolveFlags.TypeParameter;
399 case ExprClass.Value:
400 case ExprClass.Variable:
401 case ExprClass.PropertyAccess:
402 case ExprClass.EventAccess:
403 case ExprClass.IndexerAccess:
404 return ResolveFlags.VariableOrValue;
407 throw new InternalErrorException (loc.ToString () + " " + GetType () + " ExprClass is Invalid after resolve");
413 // Implements identical simple name and type-name resolution
415 public Expression ProbeIdenticalTypeName (ResolveContext rc, Expression left, SimpleName name)
418 if (t.Kind == MemberKind.InternalCompilerType || t is ElementTypeSpec || t.Arity > 0)
421 // In a member access of the form E.I, if E is a single identifier, and if the meaning of E as a simple-name is
422 // a constant, field, property, local variable, or parameter with the same type as the meaning of E as a type-name
424 if (left is MemberExpr || left is VariableReference) {
425 var identical_type = rc.LookupNamespaceOrType (name.Name, 0, LookupMode.Probing, loc) as TypeExpr;
426 if (identical_type != null && identical_type.Type == left.Type)
427 return identical_type;
433 public virtual string GetSignatureForError ()
435 return type.GetDefinition ().GetSignatureForError ();
438 public static bool IsNeverNull (Expression expr)
440 if (expr is This || expr is New || expr is ArrayCreation || expr is DelegateCreation || expr is ConditionalMemberAccess)
443 var c = expr as Constant;
447 var tc = expr as TypeCast;
449 return IsNeverNull (tc.Child);
454 protected static bool IsNullPropagatingValid (TypeSpec type)
457 case MemberKind.Struct:
458 return type.IsNullableType;
459 case MemberKind.Enum:
460 case MemberKind.Void:
461 case MemberKind.PointerType:
463 case MemberKind.InternalCompilerType:
464 return type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
465 case MemberKind.TypeParameter:
466 return !((TypeParameterSpec) type).IsValueType;
472 public virtual bool HasConditionalAccess ()
477 protected TypeSpec LiftMemberType (ResolveContext rc, TypeSpec type)
479 var tps = type as TypeParameterSpec;
480 if (tps != null && !(tps.IsReferenceType || tps.IsValueType)) {
481 Error_OperatorCannotBeApplied (rc, loc, "?", type);
484 return TypeSpec.IsValueType (type) && !type.IsNullableType ?
485 Nullable.NullableInfo.MakeType (rc.Module, type) :
490 /// Resolves an expression and performs semantic analysis on it.
494 /// Currently Resolve wraps DoResolve to perform sanity
495 /// checking and assertion checking on what we expect from Resolve.
497 public Expression Resolve (ResolveContext ec, ResolveFlags flags)
499 if (eclass != ExprClass.Unresolved) {
500 if ((flags & ExprClassToResolveFlags) == 0) {
501 Error_UnexpectedKind (ec, flags, loc);
515 if ((flags & e.ExprClassToResolveFlags) == 0) {
516 e.Error_UnexpectedKind (ec, flags, loc);
521 throw new InternalErrorException ("Expression `{0}' didn't set its type in DoResolve", e.GetType ());
524 } catch (Exception ex) {
525 if (loc.IsNull || ec.Module.Compiler.Settings.BreakOnInternalError || ex is CompletionResult || ec.Report.IsDisabled || ex is FatalException ||
526 ec.Report.Printer is NullReportPrinter)
529 ec.Report.Error (584, loc, "Internal compiler error: {0}", ex.Message);
530 return ErrorExpression.Instance; // TODO: Add location
535 /// Resolves an expression and performs semantic analysis on it.
537 public Expression Resolve (ResolveContext rc)
539 return Resolve (rc, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
543 /// Resolves an expression for LValue assignment
547 /// Currently ResolveLValue wraps DoResolveLValue to perform sanity
548 /// checking and assertion checking on what we expect from Resolve
550 public Expression ResolveLValue (ResolveContext ec, Expression right_side)
552 int errors = ec.Report.Errors;
553 bool out_access = right_side == EmptyExpression.OutAccess;
555 Expression e = DoResolveLValue (ec, right_side);
557 if (e != null && out_access && !(e is IMemoryLocation)) {
558 // FIXME: There's no problem with correctness, the 'Expr = null' handles that.
559 // Enabling this 'throw' will "only" result in deleting useless code elsewhere,
561 //throw new InternalErrorException ("ResolveLValue didn't return an IMemoryLocation: " +
562 // e.GetType () + " " + e.GetSignatureForError ());
567 if (errors == ec.Report.Errors) {
568 Error_ValueAssignment (ec, right_side);
573 if (e.eclass == ExprClass.Unresolved)
574 throw new Exception ("Expression " + e + " ExprClass is Invalid after resolve");
576 if ((e.type == null) && !(e is GenericTypeExpr))
577 throw new Exception ("Expression " + e + " did not set its type after Resolve");
582 public Constant ResolveLabelConstant (ResolveContext rc)
584 var expr = Resolve (rc);
588 Constant c = expr as Constant;
590 if (expr.type != InternalType.ErrorType)
591 rc.Report.Error (150, expr.StartLocation, "A constant value is expected");
599 public virtual void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType, TypeSpec parameterType)
601 if (Attribute.IsValidArgumentType (parameterType)) {
602 rc.Module.Compiler.Report.Error (182, loc,
603 "An attribute argument must be a constant expression, typeof expression or array creation expression");
605 rc.Module.Compiler.Report.Error (181, loc,
606 "Attribute constructor parameter has type `{0}', which is not a valid attribute parameter type",
607 targetType.GetSignatureForError ());
612 /// Emits the code for the expression
616 /// The Emit method is invoked to generate the code
617 /// for the expression.
619 public abstract void Emit (EmitContext ec);
622 // Emit code to branch to @target if this expression is equivalent to @on_true.
623 // The default implementation is to emit the value, and then emit a brtrue or brfalse.
624 // Subclasses can provide more efficient implementations, but those MUST be equivalent,
625 // including the use of conditional branches. Note also that a branch MUST be emitted
626 public virtual void EmitBranchable (EmitContext ec, Label target, bool on_true)
629 ec.Emit (on_true ? OpCodes.Brtrue : OpCodes.Brfalse, target);
632 // Emit this expression for its side effects, not for its value.
633 // The default implementation is to emit the value, and then throw it away.
634 // Subclasses can provide more efficient implementations, but those MUST be equivalent
635 public virtual void EmitSideEffect (EmitContext ec)
638 ec.Emit (OpCodes.Pop);
642 // Emits the expression into temporary field variable. The method
643 // should be used for await expressions only
645 public virtual Expression EmitToField (EmitContext ec)
648 // This is the await prepare Emit method. When emitting code like
649 // a + b we emit code like
655 // For await a + await b we have to interfere the flow to keep the
656 // stack clean because await yields from the expression. The emit
659 // a = a.EmitToField () // a is changed to temporary field access
660 // b = b.EmitToField ()
666 // The idea is to emit expression and leave the stack empty with
667 // result value still available.
669 // Expressions should override this default implementation when
670 // optimized version can be provided (e.g. FieldExpr)
673 // We can optimize for side-effect free expressions, they can be
674 // emitted out of order
676 if (IsSideEffectFree)
679 bool needs_temporary = ContainsEmitWithAwait ();
680 if (!needs_temporary)
683 // Emit original code
684 var field = EmitToFieldSource (ec);
687 // Store the result to temporary field when we
688 // cannot load `this' directly
690 field = ec.GetTemporaryField (type);
691 if (needs_temporary) {
693 // Create temporary local (we cannot load `this' before Emit)
695 var temp = ec.GetTemporaryLocal (type);
696 ec.Emit (OpCodes.Stloc, temp);
699 ec.Emit (OpCodes.Ldloc, temp);
700 field.EmitAssignFromStack (ec);
702 ec.FreeTemporaryLocal (temp, type);
704 field.EmitAssignFromStack (ec);
711 protected virtual FieldExpr EmitToFieldSource (EmitContext ec)
714 // Default implementation calls Emit method
720 protected static void EmitExpressionsList (EmitContext ec, List<Expression> expressions)
722 if (ec.HasSet (BuilderContext.Options.AsyncBody)) {
723 bool contains_await = false;
725 for (int i = 1; i < expressions.Count; ++i) {
726 if (expressions[i].ContainsEmitWithAwait ()) {
727 contains_await = true;
732 if (contains_await) {
733 for (int i = 0; i < expressions.Count; ++i) {
734 expressions[i] = expressions[i].EmitToField (ec);
739 for (int i = 0; i < expressions.Count; ++i) {
740 expressions[i].Emit (ec);
745 /// Protected constructor. Only derivate types should
746 /// be able to be created
749 protected Expression ()
754 /// Returns a fully formed expression after a MemberLookup
757 static Expression ExprClassFromMemberInfo (MemberSpec spec, Location loc)
759 if (spec is EventSpec)
760 return new EventExpr ((EventSpec) spec, loc);
761 if (spec is ConstSpec)
762 return new ConstantExpr ((ConstSpec) spec, loc);
763 if (spec is FieldSpec)
764 return new FieldExpr ((FieldSpec) spec, loc);
765 if (spec is PropertySpec)
766 return new PropertyExpr ((PropertySpec) spec, loc);
767 if (spec is TypeSpec)
768 return new TypeExpression (((TypeSpec) spec), loc);
773 public static MethodSpec ConstructorLookup (ResolveContext rc, TypeSpec type, ref Arguments args, Location loc)
775 var ctors = MemberCache.FindMembers (type, Constructor.ConstructorName, true);
778 case MemberKind.Struct:
779 // Every struct has implicit default constructor if not provided by user
783 rc.Report.SymbolRelatedToPreviousError (type);
784 // Report meaningful error for struct as they always have default ctor in C# context
785 OverloadResolver.Error_ConstructorMismatch (rc, type, args == null ? 0 : args.Count, loc);
787 case MemberKind.MissingType:
788 case MemberKind.InternalCompilerType:
789 // LAMESPEC: dynamic is not really object
790 // if (type.BuiltinType == BuiltinTypeSpec.Type.Object)
794 rc.Report.SymbolRelatedToPreviousError (type);
795 rc.Report.Error (143, loc, "The class `{0}' has no constructors defined",
796 type.GetSignatureForError ());
803 if (args == null && type.IsStruct) {
804 bool includes_empty = false;
805 foreach (MethodSpec ctor in ctors) {
806 if (ctor.Parameters.IsEmpty) {
807 includes_empty = true;
815 var r = new OverloadResolver (ctors, OverloadResolver.Restrictions.NoBaseMembers, loc);
816 if (!rc.HasSet (ResolveContext.Options.BaseInitializer)) {
817 r.InstanceQualifier = new ConstructorInstanceQualifier (type);
820 return r.ResolveMember<MethodSpec> (rc, ref args);
824 public enum MemberLookupRestrictions
830 EmptyArguments = 1 << 4,
831 IgnoreArity = 1 << 5,
832 IgnoreAmbiguity = 1 << 6,
833 NameOfExcluded = 1 << 7,
834 DontSetConditionalAccess = 1 << 8
838 // Lookup type `queried_type' for code in class `container_type' with a qualifier of
839 // `qualifier_type' or null to lookup members in the current class.
841 public static Expression MemberLookup (IMemberContext rc, bool errorMode, TypeSpec queried_type, string name, int arity, MemberLookupRestrictions restrictions, Location loc)
843 var members = MemberCache.FindMembers (queried_type, name, false);
845 if (members != null) {
848 expr = MemberLookupToExpression (rc, members, errorMode, queried_type, name, arity, restrictions, loc);
852 if (members [0].DeclaringType.BaseType == null)
855 members = MemberCache.FindMembers (members [0].DeclaringType.BaseType, name, false);
856 } while (members != null);
859 var tps = queried_type as TypeParameterSpec;
861 members = MemberCache.FindInterfaceMembers (tps, name);
863 return MemberLookupToExpression (rc, members, errorMode, queried_type, name, arity, restrictions, loc);
869 public static Expression MemberLookupToExpression (IMemberContext rc, IList<MemberSpec> members, bool errorMode, TypeSpec queried_type, string name, int arity, MemberLookupRestrictions restrictions, Location loc)
871 MemberSpec non_method = null;
872 MemberSpec ambig_non_method = null;
874 for (int i = 0; i < members.Count; ++i) {
875 var member = members [i];
877 // HACK: for events because +=/-= can appear at same class only, should use OverrideToBase there
878 if ((member.Modifiers & Modifiers.OVERRIDE) != 0 && member.Kind != MemberKind.Event)
881 if ((member.Modifiers & Modifiers.BACKING_FIELD) != 0 || member.Kind == MemberKind.Operator)
884 if ((arity > 0 || (restrictions & MemberLookupRestrictions.ExactArity) != 0) && member.Arity != arity)
888 if (!member.IsAccessible (rc))
892 // With runtime binder we can have a situation where queried type is inaccessible
893 // because it came via dynamic object, the check about inconsisted accessibility
894 // had no effect as the type was unknown during compilation
897 // private class N { }
899 // public dynamic Foo ()
905 if (rc.Module.Compiler.IsRuntimeBinder && !member.DeclaringType.IsAccessible (rc))
909 if ((restrictions & MemberLookupRestrictions.InvocableOnly) != 0) {
910 if (member is MethodSpec) {
911 return new MethodGroupExpr (members, queried_type, loc);
914 if (!Invocation.IsMemberInvocable (member))
918 if (non_method == null || member is MethodSpec || non_method.IsNotCSharpCompatible) {
920 } else if (!errorMode && !member.IsNotCSharpCompatible) {
922 // Interface members that are hidden by class members are removed from the set when T is a type parameter and
923 // T has both an effective base class other than object and a non-empty effective interface set.
925 // The spec has more complex rules but we simply remove all members declared in an interface declaration.
927 var tps = queried_type as TypeParameterSpec;
928 if (tps != null && tps.HasTypeConstraint) {
929 if (non_method.DeclaringType.IsClass && member.DeclaringType.IsInterface)
932 if (non_method.DeclaringType.IsInterface && member.DeclaringType.IsInterface) {
938 ambig_non_method = member;
942 if (non_method != null) {
943 if (ambig_non_method != null && rc != null && (restrictions & MemberLookupRestrictions.IgnoreAmbiguity) == 0) {
944 var report = rc.Module.Compiler.Report;
945 report.SymbolRelatedToPreviousError (non_method);
946 report.SymbolRelatedToPreviousError (ambig_non_method);
947 report.Error (229, loc, "Ambiguity between `{0}' and `{1}'",
948 non_method.GetSignatureForError (), ambig_non_method.GetSignatureForError ());
951 if (non_method is MethodSpec)
952 return new MethodGroupExpr (members, queried_type, loc);
954 return ExprClassFromMemberInfo (non_method, loc);
960 protected static void Error_NamedArgument (NamedArgument na, Report Report)
962 Report.Error (1742, na.Location, "An element access expression cannot use named argument");
965 protected virtual void Error_NegativeArrayIndex (ResolveContext ec, Location loc)
967 throw new NotImplementedException ();
970 public virtual void Error_OperatorCannotBeApplied (ResolveContext rc, Location loc, string oper, TypeSpec t)
972 if (t == InternalType.ErrorType)
975 rc.Report.Error (23, loc, "The `{0}' operator cannot be applied to operand of type `{1}'",
976 oper, t.GetSignatureForError ());
979 protected void Error_PointerInsideExpressionTree (ResolveContext ec)
981 ec.Report.Error (1944, loc, "An expression tree cannot contain an unsafe pointer operation");
984 protected void Error_NullShortCircuitInsideExpressionTree (ResolveContext rc)
986 rc.Report.Error (8072, loc, "An expression tree cannot contain a null propagating operator");
989 protected void Error_NullPropagatingLValue (ResolveContext rc)
991 rc.Report.Error (-1030, loc, "The left-hand side of an assignment cannot contain a null propagating operator");
994 public virtual void FlowAnalysis (FlowAnalysisContext fc)
999 // Special version of flow analysis for expressions which can return different
1000 // on-true and on-false result. Used by &&, ||, ?: expressions
1002 public virtual void FlowAnalysisConditional (FlowAnalysisContext fc)
1005 fc.DefiniteAssignmentOnTrue = fc.DefiniteAssignmentOnFalse = fc.DefiniteAssignment;
1009 /// Returns an expression that can be used to invoke operator true
1010 /// on the expression if it exists.
1012 protected static Expression GetOperatorTrue (ResolveContext ec, Expression e, Location loc)
1014 return GetOperatorTrueOrFalse (ec, e, true, loc);
1018 /// Returns an expression that can be used to invoke operator false
1019 /// on the expression if it exists.
1021 protected static Expression GetOperatorFalse (ResolveContext ec, Expression e, Location loc)
1023 return GetOperatorTrueOrFalse (ec, e, false, loc);
1026 static Expression GetOperatorTrueOrFalse (ResolveContext ec, Expression e, bool is_true, Location loc)
1028 var op = is_true ? Operator.OpType.True : Operator.OpType.False;
1030 if (type.IsNullableType)
1031 type = Nullable.NullableInfo.GetUnderlyingType (type);
1033 var methods = MemberCache.GetUserOperator (type, op, false);
1034 if (methods == null)
1037 Arguments arguments = new Arguments (1);
1038 arguments.Add (new Argument (e));
1040 var res = new OverloadResolver (methods, OverloadResolver.Restrictions.BaseMembersIncluded | OverloadResolver.Restrictions.NoBaseMembers, loc);
1041 var oper = res.ResolveOperator (ec, ref arguments);
1046 return new UserOperatorCall (oper, arguments, null, loc);
1049 public virtual string ExprClassName
1053 case ExprClass.Unresolved:
1054 return "Unresolved";
1055 case ExprClass.Value:
1057 case ExprClass.Variable:
1059 case ExprClass.Namespace:
1061 case ExprClass.Type:
1063 case ExprClass.MethodGroup:
1064 return "method group";
1065 case ExprClass.PropertyAccess:
1066 return "property access";
1067 case ExprClass.EventAccess:
1068 return "event access";
1069 case ExprClass.IndexerAccess:
1070 return "indexer access";
1071 case ExprClass.Nothing:
1073 case ExprClass.TypeParameter:
1074 return "type parameter";
1076 throw new Exception ("Should not happen");
1081 /// Reports that we were expecting `expr' to be of class `expected'
1083 public static void Error_UnexpectedKind (IMemberContext ctx, Expression memberExpr, string expected, string was, Location loc)
1085 var name = memberExpr.GetSignatureForError ();
1087 ctx.Module.Compiler.Report.Error (118, loc, "`{0}' is a `{1}' but a `{2}' was expected", name, was, expected);
1090 public virtual void Error_UnexpectedKind (ResolveContext ec, ResolveFlags flags, Location loc)
1092 string [] valid = new string [4];
1095 if ((flags & ResolveFlags.VariableOrValue) != 0) {
1096 valid [count++] = "variable";
1097 valid [count++] = "value";
1100 if ((flags & ResolveFlags.Type) != 0)
1101 valid [count++] = "type";
1103 if ((flags & ResolveFlags.MethodGroup) != 0)
1104 valid [count++] = "method group";
1107 valid [count++] = "unknown";
1109 StringBuilder sb = new StringBuilder (valid [0]);
1110 for (int i = 1; i < count - 1; i++) {
1112 sb.Append (valid [i]);
1115 sb.Append ("' or `");
1116 sb.Append (valid [count - 1]);
1119 ec.Report.Error (119, loc,
1120 "Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb.ToString ());
1123 public static void UnsafeError (ResolveContext ec, Location loc)
1125 UnsafeError (ec.Report, loc);
1128 public static void UnsafeError (Report Report, Location loc)
1130 Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
1133 public static void UnsafeInsideIteratorError (ResolveContext rc, Location loc)
1135 UnsafeInsideIteratorError (rc.Report, loc);
1138 public static void UnsafeInsideIteratorError (Report report, Location loc)
1140 report.Error (1629, loc, "Unsafe code may not appear in iterators");
1144 // Converts `source' to an int, uint, long or ulong.
1146 protected Expression ConvertExpressionToArrayIndex (ResolveContext ec, Expression source, bool pointerArray = false)
1148 var btypes = ec.BuiltinTypes;
1150 if (source.type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
1151 Arguments args = new Arguments (1);
1152 args.Add (new Argument (source));
1153 return new DynamicConversion (btypes.Int, CSharpBinderFlags.ConvertArrayIndex, args, source.loc).Resolve (ec);
1156 Expression converted;
1158 using (ec.Set (ResolveContext.Options.CheckedScope)) {
1159 converted = Convert.ImplicitConversion (ec, source, btypes.Int, source.loc);
1160 if (converted == null)
1161 converted = Convert.ImplicitConversion (ec, source, btypes.UInt, source.loc);
1162 if (converted == null)
1163 converted = Convert.ImplicitConversion (ec, source, btypes.Long, source.loc);
1164 if (converted == null)
1165 converted = Convert.ImplicitConversion (ec, source, btypes.ULong, source.loc);
1167 if (converted == null) {
1168 source.Error_ValueCannotBeConverted (ec, btypes.Int, false);
1177 // Only positive constants are allowed at compile time
1179 Constant c = converted as Constant;
1180 if (c != null && c.IsNegative)
1181 Error_NegativeArrayIndex (ec, source.loc);
1183 // No conversion needed to array index
1184 if (converted.Type.BuiltinType == BuiltinTypeSpec.Type.Int)
1187 return new ArrayIndexCast (converted, btypes.Int).Resolve (ec);
1190 public Expression MakePointerAccess (ResolveContext rc, TypeSpec type, Arguments args)
1192 if (args.Count != 1){
1193 rc.Report.Error (196, loc, "A pointer must be indexed by only one value");
1198 if (arg is NamedArgument)
1199 Error_NamedArgument ((NamedArgument) arg, rc.Report);
1201 var index = arg.Expr.Resolve (rc);
1205 index = ConvertExpressionToArrayIndex (rc, index, true);
1207 Expression p = new PointerArithmetic (Binary.Operator.Addition, this, index, type, loc);
1208 return new Indirection (p, loc);
1212 // Derived classes implement this method by cloning the fields that
1213 // could become altered during the Resolve stage
1215 // Only expressions that are created for the parser need to implement
1218 protected virtual void CloneTo (CloneContext clonectx, Expression target)
1220 throw new NotImplementedException (
1222 "CloneTo not implemented for expression {0}", this.GetType ()));
1226 // Clones an expression created by the parser.
1228 // We only support expressions created by the parser so far, not
1229 // expressions that have been resolved (many more classes would need
1230 // to implement CloneTo).
1232 // This infrastructure is here merely for Lambda expressions which
1233 // compile the same code using different type values for the same
1234 // arguments to find the correct overload
1236 public virtual Expression Clone (CloneContext clonectx)
1238 Expression cloned = (Expression) MemberwiseClone ();
1239 CloneTo (clonectx, cloned);
1245 // Implementation of expression to expression tree conversion
1247 public abstract Expression CreateExpressionTree (ResolveContext ec);
1249 protected Expression CreateExpressionFactoryCall (ResolveContext ec, string name, Arguments args)
1251 return CreateExpressionFactoryCall (ec, name, null, args, loc);
1254 protected Expression CreateExpressionFactoryCall (ResolveContext ec, string name, TypeArguments typeArguments, Arguments args)
1256 return CreateExpressionFactoryCall (ec, name, typeArguments, args, loc);
1259 public static Expression CreateExpressionFactoryCall (ResolveContext ec, string name, TypeArguments typeArguments, Arguments args, Location loc)
1261 return new Invocation (new MemberAccess (CreateExpressionTypeExpression (ec, loc), name, typeArguments, loc), args);
1264 protected static TypeExpr CreateExpressionTypeExpression (ResolveContext ec, Location loc)
1266 var t = ec.Module.PredefinedTypes.Expression.Resolve ();
1270 return new TypeExpression (t, loc);
1274 // Implemented by all expressions which support conversion from
1275 // compiler expression to invokable runtime expression. Used by
1276 // dynamic C# binder.
1278 public virtual SLE.Expression MakeExpression (BuilderContext ctx)
1280 throw new NotImplementedException ("MakeExpression for " + GetType ());
1283 public virtual object Accept (StructuralVisitor visitor)
1285 return visitor.Visit (this);
1290 /// This is just a base class for expressions that can
1291 /// appear on statements (invocations, object creation,
1292 /// assignments, post/pre increment and decrement). The idea
1293 /// being that they would support an extra Emition interface that
1294 /// does not leave a result on the stack.
1296 public abstract class ExpressionStatement : Expression
1298 public virtual void MarkReachable (Reachability rc)
1302 public virtual ExpressionStatement ResolveStatement (BlockContext ec)
1304 Expression e = Resolve (ec);
1308 ExpressionStatement es = e as ExpressionStatement;
1309 if (es == null || e is AnonymousMethodBody) {
1310 var reduced = e as IReducedExpressionStatement;
1311 if (reduced != null) {
1312 return EmptyExpressionStatement.Instance;
1315 Error_InvalidExpressionStatement (ec);
1319 // This is quite expensive warning, try to limit the damage
1321 if (MemberAccess.IsValidDotExpression (e.Type) && !(e is Assign || e is Await)) {
1322 WarningAsyncWithoutWait (ec, e);
1328 static void WarningAsyncWithoutWait (BlockContext bc, Expression e)
1330 if (bc.CurrentAnonymousMethod is AsyncInitializer) {
1331 var awaiter = new AwaitStatement.AwaitableMemberAccess (e) {
1336 // Need to do full resolve because GetAwaiter can be extension method
1337 // available only in this context
1339 var mg = awaiter.Resolve (bc) as MethodGroupExpr;
1343 var arguments = new Arguments (0);
1344 mg = mg.OverloadResolve (bc, ref arguments, null, OverloadResolver.Restrictions.ProbingOnly);
1349 // Use same check rules as for real await
1351 var awaiter_definition = bc.Module.GetAwaiter (mg.BestCandidateReturnType);
1352 if (!awaiter_definition.IsValidPattern || !awaiter_definition.INotifyCompletion)
1355 bc.Report.Warning (4014, 1, e.Location,
1356 "The statement is not awaited and execution of current method continues before the call is completed. Consider using `await' operator");
1360 var inv = e as Invocation;
1361 if (inv != null && inv.MethodGroup != null && inv.MethodGroup.BestCandidate.IsAsync) {
1362 // The warning won't be reported for imported methods to maintain warning compatiblity with csc
1363 bc.Report.Warning (4014, 1, e.Location,
1364 "The statement is not awaited and execution of current method continues before the call is completed. Consider using `await' operator or calling `Wait' method");
1370 /// Requests the expression to be emitted in a `statement'
1371 /// context. This means that no new value is left on the
1372 /// stack after invoking this method (constrasted with
1373 /// Emit that will always leave a value on the stack).
1375 public abstract void EmitStatement (EmitContext ec);
1377 public override void EmitSideEffect (EmitContext ec)
1383 interface IReducedExpressionStatement
1388 /// This kind of cast is used to encapsulate the child
1389 /// whose type is child.Type into an expression that is
1390 /// reported to return "return_type". This is used to encapsulate
1391 /// expressions which have compatible types, but need to be dealt
1392 /// at higher levels with.
1394 /// For example, a "byte" expression could be encapsulated in one
1395 /// of these as an "unsigned int". The type for the expression
1396 /// would be "unsigned int".
1399 public abstract class TypeCast : Expression
1401 protected readonly Expression child;
1403 protected TypeCast (Expression child, TypeSpec return_type)
1405 eclass = child.eclass;
1406 loc = child.Location;
1411 public Expression Child {
1417 public override bool ContainsEmitWithAwait ()
1419 return child.ContainsEmitWithAwait ();
1422 public override Expression CreateExpressionTree (ResolveContext ec)
1424 Arguments args = new Arguments (2);
1425 args.Add (new Argument (child.CreateExpressionTree (ec)));
1426 args.Add (new Argument (new TypeOf (type, loc)));
1428 if (type.IsPointer || child.Type.IsPointer)
1429 Error_PointerInsideExpressionTree (ec);
1431 return CreateExpressionFactoryCall (ec, ec.HasSet (ResolveContext.Options.CheckedScope) ? "ConvertChecked" : "Convert", args);
1434 protected override Expression DoResolve (ResolveContext ec)
1436 // This should never be invoked, we are born in fully
1437 // initialized state.
1442 public override void Emit (EmitContext ec)
1447 public override void FlowAnalysis (FlowAnalysisContext fc)
1449 child.FlowAnalysis (fc);
1452 public override SLE.Expression MakeExpression (BuilderContext ctx)
1455 return base.MakeExpression (ctx);
1457 return ctx.HasSet (BuilderContext.Options.CheckedScope) ?
1458 SLE.Expression.ConvertChecked (child.MakeExpression (ctx), type.GetMetaInfo ()) :
1459 SLE.Expression.Convert (child.MakeExpression (ctx), type.GetMetaInfo ());
1463 protected override void CloneTo (CloneContext clonectx, Expression t)
1468 public override bool IsNull {
1469 get { return child.IsNull; }
1473 public class EmptyCast : TypeCast {
1474 EmptyCast (Expression child, TypeSpec target_type)
1475 : base (child, target_type)
1479 public static Expression Create (Expression child, TypeSpec type)
1481 Constant c = child as Constant;
1483 var enum_constant = c as EnumConstant;
1484 if (enum_constant != null)
1485 c = enum_constant.Child;
1487 if (!(c is ReducedExpression.ReducedConstantExpression)) {
1491 var res = c.ConvertImplicitly (type);
1497 EmptyCast e = child as EmptyCast;
1499 return new EmptyCast (e.child, type);
1501 return new EmptyCast (child, type);
1504 public override void EmitBranchable (EmitContext ec, Label label, bool on_true)
1506 child.EmitBranchable (ec, label, on_true);
1509 public override void EmitSideEffect (EmitContext ec)
1511 child.EmitSideEffect (ec);
1516 // Used for predefined type user operator (no obsolete check, etc.)
1518 public class OperatorCast : TypeCast
1520 readonly MethodSpec conversion_operator;
1522 public OperatorCast (Expression expr, TypeSpec target_type)
1523 : this (expr, target_type, target_type, false)
1527 public OperatorCast (Expression expr, TypeSpec target_type, bool find_explicit)
1528 : this (expr, target_type, target_type, find_explicit)
1532 public OperatorCast (Expression expr, TypeSpec declaringType, TypeSpec returnType, bool isExplicit)
1533 : base (expr, returnType)
1535 var op = isExplicit ? Operator.OpType.Explicit : Operator.OpType.Implicit;
1536 var mi = MemberCache.GetUserOperator (declaringType, op, true);
1539 foreach (MethodSpec oper in mi) {
1540 if (oper.ReturnType != returnType)
1543 if (oper.Parameters.Types[0] == expr.Type) {
1544 conversion_operator = oper;
1550 throw new InternalErrorException ("Missing predefined user operator between `{0}' and `{1}'",
1551 returnType.GetSignatureForError (), expr.Type.GetSignatureForError ());
1554 public override void Emit (EmitContext ec)
1557 ec.Emit (OpCodes.Call, conversion_operator);
1562 // Constant specialization of EmptyCast.
1563 // We need to special case this since an empty cast of
1564 // a constant is still a constant.
1566 public class EmptyConstantCast : Constant
1568 public readonly Constant child;
1570 public EmptyConstantCast (Constant child, TypeSpec type)
1571 : base (child.Location)
1574 throw new ArgumentNullException ("child");
1577 this.eclass = child.eclass;
1581 public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
1583 if (child.Type == target_type)
1586 // FIXME: check that 'type' can be converted to 'target_type' first
1587 return child.ConvertExplicitly (in_checked_context, target_type);
1590 public override Expression CreateExpressionTree (ResolveContext ec)
1592 Arguments args = Arguments.CreateForExpressionTree (ec, null,
1593 child.CreateExpressionTree (ec),
1594 new TypeOf (type, loc));
1597 Error_PointerInsideExpressionTree (ec);
1599 return CreateExpressionFactoryCall (ec, "Convert", args);
1602 public override bool IsDefaultValue {
1603 get { return child.IsDefaultValue; }
1606 public override bool IsNegative {
1607 get { return child.IsNegative; }
1610 public override bool IsNull {
1611 get { return child.IsNull; }
1614 public override bool IsOneInteger {
1615 get { return child.IsOneInteger; }
1618 public override bool IsSideEffectFree {
1620 return child.IsSideEffectFree;
1624 public override bool IsZeroInteger {
1625 get { return child.IsZeroInteger; }
1628 public override void Emit (EmitContext ec)
1633 public override void EmitBranchable (EmitContext ec, Label label, bool on_true)
1635 child.EmitBranchable (ec, label, on_true);
1637 // Only to make verifier happy
1638 if (TypeManager.IsGenericParameter (type) && child.IsNull)
1639 ec.Emit (OpCodes.Unbox_Any, type);
1642 public override void EmitSideEffect (EmitContext ec)
1644 child.EmitSideEffect (ec);
1647 public override object GetValue ()
1649 return child.GetValue ();
1652 public override string GetValueAsLiteral ()
1654 return child.GetValueAsLiteral ();
1657 public override long GetValueAsLong ()
1659 return child.GetValueAsLong ();
1662 public override Constant ConvertImplicitly (TypeSpec target_type)
1664 if (type == target_type)
1667 // FIXME: Do we need to check user conversions?
1668 if (!Convert.ImplicitStandardConversionExists (this, target_type))
1671 return child.ConvertImplicitly (target_type);
1676 /// This class is used to wrap literals which belong inside Enums
1678 public class EnumConstant : Constant
1680 public Constant Child;
1682 public EnumConstant (Constant child, TypeSpec enum_type)
1683 : base (child.Location)
1687 this.eclass = ExprClass.Value;
1688 this.type = enum_type;
1691 protected EnumConstant (Location loc)
1696 public override void Emit (EmitContext ec)
1701 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType, TypeSpec parameterType)
1703 Child.EncodeAttributeValue (rc, enc, Child.Type, parameterType);
1706 public override void EmitBranchable (EmitContext ec, Label label, bool on_true)
1708 Child.EmitBranchable (ec, label, on_true);
1711 public override void EmitSideEffect (EmitContext ec)
1713 Child.EmitSideEffect (ec);
1716 public override string GetSignatureForError()
1718 return Type.GetSignatureForError ();
1721 public override object GetValue ()
1723 return Child.GetValue ();
1727 public override object GetTypedValue ()
1730 // The method can be used in dynamic context only (on closed types)
1732 // System.Enum.ToObject cannot be called on dynamic types
1733 // EnumBuilder has to be used, but we cannot use EnumBuilder
1734 // because it does not properly support generics
1736 return System.Enum.ToObject (type.GetMetaInfo (), Child.GetValue ());
1740 public override string GetValueAsLiteral ()
1742 return Child.GetValueAsLiteral ();
1745 public override long GetValueAsLong ()
1747 return Child.GetValueAsLong ();
1750 public EnumConstant Increment()
1752 return new EnumConstant (((IntegralConstant) Child).Increment (), type);
1755 public override bool IsDefaultValue {
1757 return Child.IsDefaultValue;
1761 public override bool IsSideEffectFree {
1763 return Child.IsSideEffectFree;
1767 public override bool IsZeroInteger {
1768 get { return Child.IsZeroInteger; }
1771 public override bool IsNegative {
1773 return Child.IsNegative;
1777 public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
1779 if (Child.Type == target_type)
1782 return Child.ConvertExplicitly (in_checked_context, target_type);
1785 public override Constant ConvertImplicitly (TypeSpec type)
1787 if (this.type == type) {
1791 if (!Convert.ImplicitStandardConversionExists (this, type)){
1795 return Child.ConvertImplicitly (type);
1800 /// This kind of cast is used to encapsulate Value Types in objects.
1802 /// The effect of it is to box the value type emitted by the previous
1805 public class BoxedCast : TypeCast {
1807 public BoxedCast (Expression expr, TypeSpec target_type)
1808 : base (expr, target_type)
1810 eclass = ExprClass.Value;
1813 protected override Expression DoResolve (ResolveContext ec)
1815 // This should never be invoked, we are born in fully
1816 // initialized state.
1821 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType, TypeSpec parameterType)
1823 // Only boxing to object type is supported
1824 if (targetType.BuiltinType != BuiltinTypeSpec.Type.Object) {
1825 base.EncodeAttributeValue (rc, enc, targetType, parameterType);
1829 enc.Encode (child.Type);
1830 child.EncodeAttributeValue (rc, enc, child.Type, parameterType);
1833 public override void Emit (EmitContext ec)
1837 ec.Emit (OpCodes.Box, child.Type);
1840 public override void EmitSideEffect (EmitContext ec)
1842 // boxing is side-effectful, since it involves runtime checks, except when boxing to Object or ValueType
1843 // so, we need to emit the box+pop instructions in most cases
1844 if (child.Type.IsStruct &&
1845 (type.BuiltinType == BuiltinTypeSpec.Type.Object || type.BuiltinType == BuiltinTypeSpec.Type.ValueType))
1846 child.EmitSideEffect (ec);
1848 base.EmitSideEffect (ec);
1852 public class UnboxCast : TypeCast {
1853 public UnboxCast (Expression expr, TypeSpec return_type)
1854 : base (expr, return_type)
1858 protected override Expression DoResolve (ResolveContext ec)
1860 // This should never be invoked, we are born in fully
1861 // initialized state.
1866 public override void Emit (EmitContext ec)
1870 ec.Emit (OpCodes.Unbox_Any, type);
1875 /// This is used to perform explicit numeric conversions.
1877 /// Explicit numeric conversions might trigger exceptions in a checked
1878 /// context, so they should generate the conv.ovf opcodes instead of
1881 public class ConvCast : TypeCast {
1882 public enum Mode : byte {
1883 I1_U1, I1_U2, I1_U4, I1_U8, I1_CH,
1885 I2_I1, I2_U1, I2_U2, I2_U4, I2_U8, I2_CH,
1886 U2_I1, U2_U1, U2_I2, U2_CH,
1887 I4_I1, I4_U1, I4_I2, I4_U2, I4_U4, I4_U8, I4_CH,
1888 U4_I1, U4_U1, U4_I2, U4_U2, U4_I4, U4_CH,
1889 I8_I1, I8_U1, I8_I2, I8_U2, I8_I4, I8_U4, I8_U8, I8_CH, I8_I,
1890 U8_I1, U8_U1, U8_I2, U8_U2, U8_I4, U8_U4, U8_I8, U8_CH, U8_I,
1891 CH_I1, CH_U1, CH_I2,
1892 R4_I1, R4_U1, R4_I2, R4_U2, R4_I4, R4_U4, R4_I8, R4_U8, R4_CH,
1893 R8_I1, R8_U1, R8_I2, R8_U2, R8_I4, R8_U4, R8_I8, R8_U8, R8_CH, R8_R4,
1899 public ConvCast (Expression child, TypeSpec return_type, Mode m)
1900 : base (child, return_type)
1905 protected override Expression DoResolve (ResolveContext ec)
1907 // This should never be invoked, we are born in fully
1908 // initialized state.
1913 public override string ToString ()
1915 return String.Format ("ConvCast ({0}, {1})", mode, child);
1918 public override void Emit (EmitContext ec)
1924 public static void Emit (EmitContext ec, Mode mode)
1926 if (ec.HasSet (EmitContext.Options.CheckedScope)) {
1928 case Mode.I1_U1: ec.Emit (OpCodes.Conv_Ovf_U1); break;
1929 case Mode.I1_U2: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1930 case Mode.I1_U4: ec.Emit (OpCodes.Conv_Ovf_U4); break;
1931 case Mode.I1_U8: ec.Emit (OpCodes.Conv_Ovf_U8); break;
1932 case Mode.I1_CH: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1934 case Mode.U1_I1: ec.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1935 case Mode.U1_CH: /* nothing */ break;
1937 case Mode.I2_I1: ec.Emit (OpCodes.Conv_Ovf_I1); break;
1938 case Mode.I2_U1: ec.Emit (OpCodes.Conv_Ovf_U1); break;
1939 case Mode.I2_U2: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1940 case Mode.I2_U4: ec.Emit (OpCodes.Conv_Ovf_U4); break;
1941 case Mode.I2_U8: ec.Emit (OpCodes.Conv_Ovf_U8); break;
1942 case Mode.I2_CH: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1944 case Mode.U2_I1: ec.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1945 case Mode.U2_U1: ec.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1946 case Mode.U2_I2: ec.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1947 case Mode.U2_CH: /* nothing */ break;
1949 case Mode.I4_I1: ec.Emit (OpCodes.Conv_Ovf_I1); break;
1950 case Mode.I4_U1: ec.Emit (OpCodes.Conv_Ovf_U1); break;
1951 case Mode.I4_I2: ec.Emit (OpCodes.Conv_Ovf_I2); break;
1952 case Mode.I4_U4: ec.Emit (OpCodes.Conv_Ovf_U4); break;
1953 case Mode.I4_U2: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1954 case Mode.I4_U8: ec.Emit (OpCodes.Conv_Ovf_U8); break;
1955 case Mode.I4_CH: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1957 case Mode.U4_I1: ec.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1958 case Mode.U4_U1: ec.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1959 case Mode.U4_I2: ec.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1960 case Mode.U4_U2: ec.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1961 case Mode.U4_I4: ec.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1962 case Mode.U4_CH: ec.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1964 case Mode.I8_I1: ec.Emit (OpCodes.Conv_Ovf_I1); break;
1965 case Mode.I8_U1: ec.Emit (OpCodes.Conv_Ovf_U1); break;
1966 case Mode.I8_I2: ec.Emit (OpCodes.Conv_Ovf_I2); break;
1967 case Mode.I8_U2: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1968 case Mode.I8_I4: ec.Emit (OpCodes.Conv_Ovf_I4); break;
1969 case Mode.I8_U4: ec.Emit (OpCodes.Conv_Ovf_U4); break;
1970 case Mode.I8_U8: ec.Emit (OpCodes.Conv_Ovf_U8); break;
1971 case Mode.I8_CH: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1972 case Mode.I8_I: ec.Emit (OpCodes.Conv_Ovf_U); break;
1974 case Mode.U8_I1: ec.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1975 case Mode.U8_U1: ec.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1976 case Mode.U8_I2: ec.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1977 case Mode.U8_U2: ec.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1978 case Mode.U8_I4: ec.Emit (OpCodes.Conv_Ovf_I4_Un); break;
1979 case Mode.U8_U4: ec.Emit (OpCodes.Conv_Ovf_U4_Un); break;
1980 case Mode.U8_I8: ec.Emit (OpCodes.Conv_Ovf_I8_Un); break;
1981 case Mode.U8_CH: ec.Emit (OpCodes.Conv_Ovf_U2_Un); break;
1982 case Mode.U8_I: ec.Emit (OpCodes.Conv_Ovf_U_Un); break;
1984 case Mode.CH_I1: ec.Emit (OpCodes.Conv_Ovf_I1_Un); break;
1985 case Mode.CH_U1: ec.Emit (OpCodes.Conv_Ovf_U1_Un); break;
1986 case Mode.CH_I2: ec.Emit (OpCodes.Conv_Ovf_I2_Un); break;
1988 case Mode.R4_I1: ec.Emit (OpCodes.Conv_Ovf_I1); break;
1989 case Mode.R4_U1: ec.Emit (OpCodes.Conv_Ovf_U1); break;
1990 case Mode.R4_I2: ec.Emit (OpCodes.Conv_Ovf_I2); break;
1991 case Mode.R4_U2: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1992 case Mode.R4_I4: ec.Emit (OpCodes.Conv_Ovf_I4); break;
1993 case Mode.R4_U4: ec.Emit (OpCodes.Conv_Ovf_U4); break;
1994 case Mode.R4_I8: ec.Emit (OpCodes.Conv_Ovf_I8); break;
1995 case Mode.R4_U8: ec.Emit (OpCodes.Conv_Ovf_U8); break;
1996 case Mode.R4_CH: ec.Emit (OpCodes.Conv_Ovf_U2); break;
1998 case Mode.R8_I1: ec.Emit (OpCodes.Conv_Ovf_I1); break;
1999 case Mode.R8_U1: ec.Emit (OpCodes.Conv_Ovf_U1); break;
2000 case Mode.R8_I2: ec.Emit (OpCodes.Conv_Ovf_I2); break;
2001 case Mode.R8_U2: ec.Emit (OpCodes.Conv_Ovf_U2); break;
2002 case Mode.R8_I4: ec.Emit (OpCodes.Conv_Ovf_I4); break;
2003 case Mode.R8_U4: ec.Emit (OpCodes.Conv_Ovf_U4); break;
2004 case Mode.R8_I8: ec.Emit (OpCodes.Conv_Ovf_I8); break;
2005 case Mode.R8_U8: ec.Emit (OpCodes.Conv_Ovf_U8); break;
2006 case Mode.R8_CH: ec.Emit (OpCodes.Conv_Ovf_U2); break;
2007 case Mode.R8_R4: ec.Emit (OpCodes.Conv_R4); break;
2009 case Mode.I_I8: ec.Emit (OpCodes.Conv_Ovf_I8_Un); break;
2013 case Mode.I1_U1: ec.Emit (OpCodes.Conv_U1); break;
2014 case Mode.I1_U2: ec.Emit (OpCodes.Conv_U2); break;
2015 case Mode.I1_U4: ec.Emit (OpCodes.Conv_U4); break;
2016 case Mode.I1_U8: ec.Emit (OpCodes.Conv_I8); break;
2017 case Mode.I1_CH: ec.Emit (OpCodes.Conv_U2); break;
2019 case Mode.U1_I1: ec.Emit (OpCodes.Conv_I1); break;
2020 case Mode.U1_CH: ec.Emit (OpCodes.Conv_U2); break;
2022 case Mode.I2_I1: ec.Emit (OpCodes.Conv_I1); break;
2023 case Mode.I2_U1: ec.Emit (OpCodes.Conv_U1); break;
2024 case Mode.I2_U2: ec.Emit (OpCodes.Conv_U2); break;
2025 case Mode.I2_U4: ec.Emit (OpCodes.Conv_U4); break;
2026 case Mode.I2_U8: ec.Emit (OpCodes.Conv_I8); break;
2027 case Mode.I2_CH: ec.Emit (OpCodes.Conv_U2); break;
2029 case Mode.U2_I1: ec.Emit (OpCodes.Conv_I1); break;
2030 case Mode.U2_U1: ec.Emit (OpCodes.Conv_U1); break;
2031 case Mode.U2_I2: ec.Emit (OpCodes.Conv_I2); break;
2032 case Mode.U2_CH: /* nothing */ break;
2034 case Mode.I4_I1: ec.Emit (OpCodes.Conv_I1); break;
2035 case Mode.I4_U1: ec.Emit (OpCodes.Conv_U1); break;
2036 case Mode.I4_I2: ec.Emit (OpCodes.Conv_I2); break;
2037 case Mode.I4_U4: /* nothing */ break;
2038 case Mode.I4_U2: ec.Emit (OpCodes.Conv_U2); break;
2039 case Mode.I4_U8: ec.Emit (OpCodes.Conv_I8); break;
2040 case Mode.I4_CH: ec.Emit (OpCodes.Conv_U2); break;
2042 case Mode.U4_I1: ec.Emit (OpCodes.Conv_I1); break;
2043 case Mode.U4_U1: ec.Emit (OpCodes.Conv_U1); break;
2044 case Mode.U4_I2: ec.Emit (OpCodes.Conv_I2); break;
2045 case Mode.U4_U2: ec.Emit (OpCodes.Conv_U2); break;
2046 case Mode.U4_I4: /* nothing */ break;
2047 case Mode.U4_CH: ec.Emit (OpCodes.Conv_U2); break;
2049 case Mode.I8_I1: ec.Emit (OpCodes.Conv_I1); break;
2050 case Mode.I8_U1: ec.Emit (OpCodes.Conv_U1); break;
2051 case Mode.I8_I2: ec.Emit (OpCodes.Conv_I2); break;
2052 case Mode.I8_U2: ec.Emit (OpCodes.Conv_U2); break;
2053 case Mode.I8_I4: ec.Emit (OpCodes.Conv_I4); break;
2054 case Mode.I8_U4: ec.Emit (OpCodes.Conv_U4); break;
2055 case Mode.I8_U8: /* nothing */ break;
2056 case Mode.I8_CH: ec.Emit (OpCodes.Conv_U2); break;
2057 case Mode.I8_I: ec.Emit (OpCodes.Conv_U); break;
2059 case Mode.U8_I1: ec.Emit (OpCodes.Conv_I1); break;
2060 case Mode.U8_U1: ec.Emit (OpCodes.Conv_U1); break;
2061 case Mode.U8_I2: ec.Emit (OpCodes.Conv_I2); break;
2062 case Mode.U8_U2: ec.Emit (OpCodes.Conv_U2); break;
2063 case Mode.U8_I4: ec.Emit (OpCodes.Conv_I4); break;
2064 case Mode.U8_U4: ec.Emit (OpCodes.Conv_U4); break;
2065 case Mode.U8_I8: /* nothing */ break;
2066 case Mode.U8_CH: ec.Emit (OpCodes.Conv_U2); break;
2067 case Mode.U8_I: ec.Emit (OpCodes.Conv_U); break;
2069 case Mode.CH_I1: ec.Emit (OpCodes.Conv_I1); break;
2070 case Mode.CH_U1: ec.Emit (OpCodes.Conv_U1); break;
2071 case Mode.CH_I2: ec.Emit (OpCodes.Conv_I2); break;
2073 case Mode.R4_I1: ec.Emit (OpCodes.Conv_I1); break;
2074 case Mode.R4_U1: ec.Emit (OpCodes.Conv_U1); break;
2075 case Mode.R4_I2: ec.Emit (OpCodes.Conv_I2); break;
2076 case Mode.R4_U2: ec.Emit (OpCodes.Conv_U2); break;
2077 case Mode.R4_I4: ec.Emit (OpCodes.Conv_I4); break;
2078 case Mode.R4_U4: ec.Emit (OpCodes.Conv_U4); break;
2079 case Mode.R4_I8: ec.Emit (OpCodes.Conv_I8); break;
2080 case Mode.R4_U8: ec.Emit (OpCodes.Conv_U8); break;
2081 case Mode.R4_CH: ec.Emit (OpCodes.Conv_U2); break;
2083 case Mode.R8_I1: ec.Emit (OpCodes.Conv_I1); break;
2084 case Mode.R8_U1: ec.Emit (OpCodes.Conv_U1); break;
2085 case Mode.R8_I2: ec.Emit (OpCodes.Conv_I2); break;
2086 case Mode.R8_U2: ec.Emit (OpCodes.Conv_U2); break;
2087 case Mode.R8_I4: ec.Emit (OpCodes.Conv_I4); break;
2088 case Mode.R8_U4: ec.Emit (OpCodes.Conv_U4); break;
2089 case Mode.R8_I8: ec.Emit (OpCodes.Conv_I8); break;
2090 case Mode.R8_U8: ec.Emit (OpCodes.Conv_U8); break;
2091 case Mode.R8_CH: ec.Emit (OpCodes.Conv_U2); break;
2092 case Mode.R8_R4: ec.Emit (OpCodes.Conv_R4); break;
2094 case Mode.I_I8: ec.Emit (OpCodes.Conv_U8); break;
2100 class OpcodeCast : TypeCast
2104 public OpcodeCast (Expression child, TypeSpec return_type, OpCode op)
2105 : base (child, return_type)
2110 protected override Expression DoResolve (ResolveContext ec)
2112 // This should never be invoked, we are born in fully
2113 // initialized state.
2118 public override void Emit (EmitContext ec)
2124 public TypeSpec UnderlyingType {
2125 get { return child.Type; }
2130 // Opcode casts expression with 2 opcodes but only
2131 // single expression tree node
2133 class OpcodeCastDuplex : OpcodeCast
2135 readonly OpCode second;
2137 public OpcodeCastDuplex (Expression child, TypeSpec returnType, OpCode first, OpCode second)
2138 : base (child, returnType, first)
2140 this.second = second;
2143 public override void Emit (EmitContext ec)
2151 /// This kind of cast is used to encapsulate a child and cast it
2152 /// to the class requested
2154 public sealed class ClassCast : TypeCast {
2155 readonly bool forced;
2157 public ClassCast (Expression child, TypeSpec return_type)
2158 : base (child, return_type)
2162 public ClassCast (Expression child, TypeSpec return_type, bool forced)
2163 : base (child, return_type)
2165 this.forced = forced;
2168 public override void Emit (EmitContext ec)
2172 bool gen = TypeManager.IsGenericParameter (child.Type);
2174 ec.Emit (OpCodes.Box, child.Type);
2176 if (type.IsGenericParameter) {
2177 ec.Emit (OpCodes.Unbox_Any, type);
2184 ec.Emit (OpCodes.Castclass, type);
2189 // Created during resolving pahse when an expression is wrapped or constantified
2190 // and original expression can be used later (e.g. for expression trees)
2192 public class ReducedExpression : Expression
2194 public class ReducedConstantExpression : EmptyConstantCast
2196 readonly Expression orig_expr;
2198 public ReducedConstantExpression (Constant expr, Expression orig_expr)
2199 : base (expr, expr.Type)
2201 this.orig_expr = orig_expr;
2204 public Expression OriginalExpression {
2210 public override Constant ConvertImplicitly (TypeSpec target_type)
2212 Constant c = base.ConvertImplicitly (target_type);
2214 c = new ReducedConstantExpression (c, orig_expr);
2219 public override Expression CreateExpressionTree (ResolveContext ec)
2221 return orig_expr.CreateExpressionTree (ec);
2224 public override Constant ConvertExplicitly (bool in_checked_context, TypeSpec target_type)
2226 Constant c = base.ConvertExplicitly (in_checked_context, target_type);
2228 c = new ReducedConstantExpression (c, orig_expr);
2232 public override void EncodeAttributeValue (IMemberContext rc, AttributeEncoder enc, TypeSpec targetType, TypeSpec parameterType)
2235 // LAMESPEC: Reduced conditional expression is allowed as an attribute argument
2237 if (orig_expr is Conditional)
2238 child.EncodeAttributeValue (rc, enc, targetType,parameterType);
2240 base.EncodeAttributeValue (rc, enc, targetType, parameterType);
2244 sealed class ReducedConstantStatement : ReducedConstantExpression, IReducedExpressionStatement
2246 public ReducedConstantStatement (Constant expr, Expression origExpr)
2247 : base (expr, origExpr)
2252 sealed class ReducedExpressionStatement : ExpressionStatement
2254 readonly Expression orig_expr;
2255 readonly ExpressionStatement stm;
2257 public ReducedExpressionStatement (ExpressionStatement stm, Expression orig)
2259 this.orig_expr = orig;
2261 this.eclass = stm.eclass;
2262 this.type = stm.Type;
2264 this.loc = orig.Location;
2267 public override bool ContainsEmitWithAwait ()
2269 return stm.ContainsEmitWithAwait ();
2272 public override Expression CreateExpressionTree (ResolveContext ec)
2274 return orig_expr.CreateExpressionTree (ec);
2277 protected override Expression DoResolve (ResolveContext ec)
2282 public override void Emit (EmitContext ec)
2287 public override void EmitStatement (EmitContext ec)
2289 stm.EmitStatement (ec);
2292 public override void FlowAnalysis (FlowAnalysisContext fc)
2294 stm.FlowAnalysis (fc);
2298 readonly Expression expr, orig_expr;
2300 private ReducedExpression (Expression expr, Expression orig_expr)
2303 this.eclass = expr.eclass;
2304 this.type = expr.Type;
2305 this.orig_expr = orig_expr;
2306 this.loc = orig_expr.Location;
2311 public override bool IsSideEffectFree {
2313 return expr.IsSideEffectFree;
2317 public Expression OriginalExpression {
2325 public override bool ContainsEmitWithAwait ()
2327 return expr.ContainsEmitWithAwait ();
2331 // Creates fully resolved expression switcher
2333 public static Constant Create (Constant expr, Expression originalExpr)
2335 if (expr.eclass == ExprClass.Unresolved)
2336 throw new ArgumentException ("Unresolved expression");
2338 if (originalExpr is ExpressionStatement)
2339 return new ReducedConstantStatement (expr, originalExpr);
2341 return new ReducedConstantExpression (expr, originalExpr);
2344 public static ExpressionStatement Create (ExpressionStatement s, Expression orig)
2346 return new ReducedExpressionStatement (s, orig);
2349 public static Expression Create (Expression expr, Expression original_expr)
2351 return Create (expr, original_expr, true);
2355 // Creates unresolved reduce expression. The original expression has to be
2356 // already resolved. Created expression is constant based based on `expr'
2357 // value unless canBeConstant is used
2359 public static Expression Create (Expression expr, Expression original_expr, bool canBeConstant)
2361 if (canBeConstant) {
2362 Constant c = expr as Constant;
2364 return Create (c, original_expr);
2367 ExpressionStatement s = expr as ExpressionStatement;
2369 return Create (s, original_expr);
2371 if (expr.eclass == ExprClass.Unresolved)
2372 throw new ArgumentException ("Unresolved expression");
2374 return new ReducedExpression (expr, original_expr);
2377 public override Expression CreateExpressionTree (ResolveContext ec)
2379 return orig_expr.CreateExpressionTree (ec);
2382 protected override Expression DoResolve (ResolveContext ec)
2387 public override void Emit (EmitContext ec)
2392 public override Expression EmitToField (EmitContext ec)
2394 return expr.EmitToField(ec);
2397 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
2399 expr.EmitBranchable (ec, target, on_true);
2402 public override void FlowAnalysis (FlowAnalysisContext fc)
2404 expr.FlowAnalysis (fc);
2407 public override SLE.Expression MakeExpression (BuilderContext ctx)
2409 return orig_expr.MakeExpression (ctx);
2414 // Standard composite pattern
2416 public abstract class CompositeExpression : Expression
2418 protected Expression expr;
2420 protected CompositeExpression (Expression expr)
2423 this.loc = expr.Location;
2426 public override bool ContainsEmitWithAwait ()
2428 return expr.ContainsEmitWithAwait ();
2431 public override Expression CreateExpressionTree (ResolveContext rc)
2433 return expr.CreateExpressionTree (rc);
2436 public Expression Child {
2437 get { return expr; }
2440 protected override Expression DoResolve (ResolveContext rc)
2442 expr = expr.Resolve (rc);
2447 eclass = expr.eclass;
2451 public override void Emit (EmitContext ec)
2456 public override bool IsNull {
2457 get { return expr.IsNull; }
2462 // Base of expressions used only to narrow resolve flow
2464 public abstract class ShimExpression : Expression
2466 protected Expression expr;
2468 protected ShimExpression (Expression expr)
2473 public Expression Expr {
2479 protected override void CloneTo (CloneContext clonectx, Expression t)
2484 ShimExpression target = (ShimExpression) t;
2485 target.expr = expr.Clone (clonectx);
2488 public override bool ContainsEmitWithAwait ()
2490 return expr.ContainsEmitWithAwait ();
2493 public override Expression CreateExpressionTree (ResolveContext ec)
2495 throw new NotSupportedException ("ET");
2498 public override void Emit (EmitContext ec)
2500 throw new InternalErrorException ("Missing Resolve call");
2504 public class UnreachableExpression : Expression
2506 public UnreachableExpression (Expression expr)
2508 this.loc = expr.Location;
2511 public override Expression CreateExpressionTree (ResolveContext ec)
2514 throw new NotImplementedException ();
2517 protected override Expression DoResolve (ResolveContext rc)
2519 throw new NotSupportedException ();
2522 public override void FlowAnalysis (FlowAnalysisContext fc)
2524 fc.Report.Warning (429, 4, loc, "Unreachable expression code detected");
2527 public override void Emit (EmitContext ec)
2531 public override void EmitBranchable (EmitContext ec, Label target, bool on_true)
2537 // Unresolved type name expressions
2539 public abstract class ATypeNameExpression : FullNamedExpression
2542 protected TypeArguments targs;
2544 protected ATypeNameExpression (string name, Location l)
2550 protected ATypeNameExpression (string name, TypeArguments targs, Location l)
2557 protected ATypeNameExpression (string name, int arity, Location l)
2558 : this (name, new UnboundTypeArguments (arity, l), l)
2566 return targs == null ? 0 : targs.Count;
2570 public bool HasTypeArguments {
2572 return targs != null && !targs.IsEmpty;
2576 public string Name {
2585 public TypeArguments TypeArguments {
2593 public override bool Equals (object obj)
2595 ATypeNameExpression atne = obj as ATypeNameExpression;
2596 return atne != null && atne.Name == Name &&
2597 (targs == null || targs.Equals (atne.targs));
2600 public override int GetHashCode ()
2602 return Name.GetHashCode ();
2605 // TODO: Move it to MemberCore
2606 public static string GetMemberType (MemberCore mc)
2612 if (mc is FieldBase)
2614 if (mc is MethodCore)
2616 if (mc is EnumMember)
2624 public override string GetSignatureForError ()
2626 if (targs != null) {
2627 return Name + "<" + targs.GetSignatureForError () + ">";
2633 public abstract Expression LookupNameExpression (ResolveContext rc, MemberLookupRestrictions restriction);
2637 /// SimpleName expressions are formed of a single word and only happen at the beginning
2638 /// of a dotted-name.
2640 public class SimpleName : ATypeNameExpression
2642 public SimpleName (string name, Location l)
2647 public SimpleName (string name, TypeArguments args, Location l)
2648 : base (name, args, l)
2652 public SimpleName (string name, int arity, Location l)
2653 : base (name, arity, l)
2657 public SimpleName GetMethodGroup ()
2659 return new SimpleName (Name, targs, loc);
2662 protected override Expression DoResolve (ResolveContext rc)
2664 return SimpleNameResolve (rc, null);
2667 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
2669 return SimpleNameResolve (ec, right_side);
2672 public void Error_NameDoesNotExist (ResolveContext rc)
2674 rc.Report.Error (103, loc, "The name `{0}' does not exist in the current context", Name);
2677 protected virtual void Error_TypeOrNamespaceNotFound (IMemberContext ctx)
2679 if (ctx.CurrentType != null) {
2680 var member = MemberLookup (ctx, false, ctx.CurrentType, Name, 0, MemberLookupRestrictions.ExactArity, loc) as MemberExpr;
2681 if (member != null) {
2682 Error_UnexpectedKind (ctx, member, "type", member.KindName, loc);
2687 var report = ctx.Module.Compiler.Report;
2689 var retval = ctx.LookupNamespaceOrType (Name, Arity, LookupMode.IgnoreAccessibility, loc);
2690 if (retval != null) {
2691 report.SymbolRelatedToPreviousError (retval.Type);
2692 ErrorIsInaccesible (ctx, retval.GetSignatureForError (), loc);
2696 retval = ctx.LookupNamespaceOrType (Name, -System.Math.Max (1, Arity), LookupMode.Probing, loc);
2697 if (retval != null) {
2698 Error_TypeArgumentsCannotBeUsed (ctx, retval.Type, loc);
2702 var ns_candidates = ctx.Module.GlobalRootNamespace.FindTypeNamespaces (ctx, Name, Arity);
2703 if (ns_candidates != null) {
2704 if (ctx is UsingAliasNamespace.AliasContext) {
2705 report.Error (246, loc,
2706 "The type or namespace name `{1}' could not be found. Consider using fully qualified name `{0}.{1}'",
2707 ns_candidates[0], Name);
2709 string usings = string.Join ("' or `", ns_candidates.ToArray ());
2710 report.Error (246, loc,
2711 "The type or namespace name `{0}' could not be found. Are you missing `{1}' using directive?",
2715 report.Error (246, loc,
2716 "The type or namespace name `{0}' could not be found. Are you missing an assembly reference?",
2721 public override FullNamedExpression ResolveAsTypeOrNamespace (IMemberContext mc, bool allowUnboundTypeArguments)
2723 FullNamedExpression fne = mc.LookupNamespaceOrType (Name, Arity, LookupMode.Normal, loc);
2726 if (fne.Type != null && Arity > 0) {
2727 if (HasTypeArguments) {
2728 GenericTypeExpr ct = new GenericTypeExpr (fne.Type, targs, loc);
2729 if (ct.ResolveAsType (mc) == null)
2735 targs.Resolve (mc, allowUnboundTypeArguments);
2737 return new GenericOpenTypeExpr (fne.Type, loc);
2741 // dynamic namespace is ignored when dynamic is allowed (does not apply to types)
2743 if (!(fne is NamespaceExpression))
2747 if (Arity == 0 && Name == "dynamic" && !(mc is NamespaceContainer) && mc.Module.Compiler.Settings.Version > LanguageVersion.V_3) {
2748 if (!mc.Module.PredefinedAttributes.Dynamic.IsDefined) {
2749 mc.Module.Compiler.Report.Error (1980, Location,
2750 "Dynamic keyword requires `{0}' to be defined. Are you missing System.Core.dll assembly reference?",
2751 mc.Module.PredefinedAttributes.Dynamic.GetSignatureForError ());
2754 fne = new DynamicTypeExpr (loc);
2755 fne.ResolveAsType (mc);
2761 Error_TypeOrNamespaceNotFound (mc);
2765 public bool IsPossibleTypeOrNamespace (IMemberContext mc)
2767 return mc.LookupNamespaceOrType (Name, Arity, LookupMode.Probing, loc) != null;
2770 public bool IsPossibleType (IMemberContext mc)
2772 return mc.LookupNamespaceOrType (Name, Arity, LookupMode.Probing, loc) is TypeExpr;
2775 public override Expression LookupNameExpression (ResolveContext rc, MemberLookupRestrictions restrictions)
2777 int lookup_arity = Arity;
2778 bool errorMode = false;
2780 Block current_block = rc.CurrentBlock;
2781 INamedBlockVariable variable = null;
2782 bool variable_found = false;
2786 // Stage 1: binding to local variables or parameters
2788 // LAMESPEC: It should take invocableOnly into account but that would break csc compatibility
2790 if (current_block != null && lookup_arity == 0) {
2791 if (current_block.ParametersBlock.TopBlock.GetLocalName (Name, current_block.Original, ref variable)) {
2792 if (!variable.IsDeclared) {
2793 // We found local name in accessible block but it's not
2794 // initialized yet, maybe the user wanted to bind to something else
2796 variable_found = true;
2798 e = variable.CreateReferenceExpression (rc, loc);
2801 Error_TypeArgumentsCannotBeUsed (rc, "variable", Name, loc);
2810 // Stage 2: Lookup members if we are inside a type up to top level type for nested types
2812 TypeSpec member_type = rc.CurrentType;
2813 for (; member_type != null; member_type = member_type.DeclaringType) {
2814 e = MemberLookup (rc, errorMode, member_type, Name, lookup_arity, restrictions, loc);
2818 var me = e as MemberExpr;
2820 // The name matches a type, defer to ResolveAsTypeStep
2828 if (variable != null) {
2829 if (me is FieldExpr || me is ConstantExpr || me is EventExpr || me is PropertyExpr) {
2830 rc.Report.Error (844, loc,
2831 "A local variable `{0}' cannot be used before it is declared. Consider renaming the local variable when it hides the member `{1}'",
2832 Name, me.GetSignatureForError ());
2836 } else if (me is MethodGroupExpr || me is PropertyExpr || me is IndexerExpr) {
2837 // Leave it to overload resolution to report correct error
2839 // TODO: rc.Report.SymbolRelatedToPreviousError ()
2840 ErrorIsInaccesible (rc, me.GetSignatureForError (), loc);
2844 // MemberLookup does not check accessors availability, this is actually needed for properties only
2846 var pe = me as PropertyExpr;
2849 // Break as there is no other overload available anyway
2850 if ((restrictions & MemberLookupRestrictions.ReadAccess) != 0) {
2851 if (!pe.PropertyInfo.HasGet || !pe.PropertyInfo.Get.IsAccessible (rc))
2854 pe.Getter = pe.PropertyInfo.Get;
2856 if (!pe.PropertyInfo.HasSet) {
2857 if (rc.HasSet (ResolveContext.Options.ConstructorScope) && pe.IsAutoPropertyAccess &&
2858 pe.PropertyInfo.DeclaringType == rc.CurrentType && pe.IsStatic == rc.IsStatic) {
2859 var p = (Property) pe.PropertyInfo.MemberDefinition;
2860 return new FieldExpr (p.BackingField, loc);
2863 variable_found = true;
2867 if (!pe.PropertyInfo.Set.IsAccessible (rc)) {
2868 variable_found = true;
2872 pe.Setter = pe.PropertyInfo.Set;
2877 // TODO: It's used by EventExpr -> FieldExpr transformation only
2878 // TODO: Should go to MemberAccess
2879 me = me.ResolveMemberAccess (rc, null, null);
2882 targs.Resolve (rc, false);
2883 me.SetTypeArguments (rc, targs);
2889 var expr = NamespaceContainer.LookupStaticUsings (rc, Name, Arity, loc);
2892 targs.Resolve (rc, false);
2894 var me = expr as MemberExpr;
2896 me.SetTypeArguments (rc, targs);
2902 // Stage 3: Lookup nested types, namespaces and type parameters in the context
2904 if ((restrictions & MemberLookupRestrictions.InvocableOnly) == 0 && !variable_found) {
2905 if (IsPossibleTypeOrNamespace (rc)) {
2906 return ResolveAsTypeOrNamespace (rc, false);
2910 if ((restrictions & MemberLookupRestrictions.NameOfExcluded) == 0 && Name == "nameof")
2911 return new NameOf (this);
2914 if (variable_found) {
2915 rc.Report.Error (841, loc, "A local variable `{0}' cannot be used before it is declared", Name);
2918 var tparams = rc.CurrentTypeParameters;
2919 if (tparams != null) {
2920 if (tparams.Find (Name) != null) {
2921 Error_TypeArgumentsCannotBeUsed (rc, "type parameter", Name, loc);
2926 var ct = rc.CurrentType;
2928 if (ct.MemberDefinition.TypeParametersCount > 0) {
2929 foreach (var ctp in ct.MemberDefinition.TypeParameters) {
2930 if (ctp.Name == Name) {
2931 Error_TypeArgumentsCannotBeUsed (rc, "type parameter", Name, loc);
2937 ct = ct.DeclaringType;
2938 } while (ct != null);
2941 if ((restrictions & MemberLookupRestrictions.InvocableOnly) == 0) {
2942 e = rc.LookupNamespaceOrType (Name, Arity, LookupMode.IgnoreAccessibility, loc);
2944 rc.Report.SymbolRelatedToPreviousError (e.Type);
2945 ErrorIsInaccesible (rc, e.GetSignatureForError (), loc);
2949 var me = MemberLookup (rc, false, rc.CurrentType, Name, Arity, restrictions & ~MemberLookupRestrictions.InvocableOnly, loc) as MemberExpr;
2951 Error_UnexpectedKind (rc, me, "method group", me.KindName, loc);
2952 return ErrorExpression.Instance;
2956 e = rc.LookupNamespaceOrType (Name, -System.Math.Max (1, Arity), LookupMode.Probing, loc);
2958 if (e.Type.Arity != Arity && (restrictions & MemberLookupRestrictions.IgnoreArity) == 0) {
2959 Error_TypeArgumentsCannotBeUsed (rc, e.Type, loc);
2963 if (e is TypeExpr) {
2964 // TypeExpression does not have correct location
2965 if (e is TypeExpression)
2966 e = new TypeExpression (e.Type, loc);
2972 Error_NameDoesNotExist (rc);
2975 return ErrorExpression.Instance;
2978 if (rc.Module.Evaluator != null) {
2979 var fi = rc.Module.Evaluator.LookupField (Name);
2981 return new FieldExpr (fi.Item1, loc);
2989 Expression SimpleNameResolve (ResolveContext ec, Expression right_side)
2991 Expression e = LookupNameExpression (ec, right_side == null ? MemberLookupRestrictions.ReadAccess : MemberLookupRestrictions.None);
2996 if (e is FullNamedExpression && e.eclass != ExprClass.Unresolved) {
2997 Error_UnexpectedKind (ec, e, "variable", e.ExprClassName, loc);
3001 if (right_side != null) {
3002 e = e.ResolveLValue (ec, right_side);
3010 public override object Accept (StructuralVisitor visitor)
3012 return visitor.Visit (this);
3017 /// Represents a namespace or a type. The name of the class was inspired by
3018 /// section 10.8.1 (Fully Qualified Names).
3020 public abstract class FullNamedExpression : Expression
3022 protected override void CloneTo (CloneContext clonectx, Expression target)
3024 // Do nothing, most unresolved type expressions cannot be
3025 // resolved to different type
3028 public override bool ContainsEmitWithAwait ()
3033 public override Expression CreateExpressionTree (ResolveContext ec)
3035 throw new NotSupportedException ("ET");
3038 public abstract FullNamedExpression ResolveAsTypeOrNamespace (IMemberContext mc, bool allowUnboundTypeArguments);
3041 // This is used to resolve the expression as a type, a null
3042 // value will be returned if the expression is not a type
3045 public override TypeSpec ResolveAsType (IMemberContext mc, bool allowUnboundTypeArguments = false)
3047 FullNamedExpression fne = ResolveAsTypeOrNamespace (mc, allowUnboundTypeArguments);
3052 TypeExpr te = fne as TypeExpr;
3054 Error_UnexpectedKind (mc, fne, "type", fne.ExprClassName, loc);
3062 var dep = type.GetMissingDependencies ();
3064 ImportedTypeDefinition.Error_MissingDependency (mc, dep, loc);
3067 if (type.Kind == MemberKind.Void) {
3068 mc.Module.Compiler.Report.Error (673, loc, "System.Void cannot be used from C#. Consider using `void'");
3072 // Obsolete checks cannot be done when resolving base context as they
3073 // require type dependencies to be set but we are in process of resolving them
3075 if (mc is ResolveContext) {
3076 var oa = type.GetAttributeObsolete ();
3077 if (oa != null && !mc.IsObsolete)
3078 AttributeTester.Report_ObsoleteMessage (oa, type.GetSignatureForError (), fne.Location, mc.Module.Compiler.Report);
3085 public override void Emit (EmitContext ec)
3087 throw new InternalErrorException ("FullNamedExpression `{0}' found in resolved tree",
3088 GetSignatureForError ());
3093 /// Expression that evaluates to a type
3095 public abstract class TypeExpr : FullNamedExpression
3097 public sealed override FullNamedExpression ResolveAsTypeOrNamespace (IMemberContext mc, bool allowUnboundTypeArguments)
3103 protected sealed override Expression DoResolve (ResolveContext ec)
3109 public override bool Equals (object obj)
3111 TypeExpr tobj = obj as TypeExpr;
3115 return Type == tobj.Type;
3118 public override int GetHashCode ()
3120 return Type.GetHashCode ();
3125 /// Fully resolved Expression that already evaluated to a type
3127 public class TypeExpression : TypeExpr
3129 public TypeExpression (TypeSpec t, Location l)
3132 eclass = ExprClass.Type;
3136 public sealed override TypeSpec ResolveAsType (IMemberContext mc, bool allowUnboundTypeArguments = false)
3142 public class NamespaceExpression : FullNamedExpression
3144 readonly Namespace ns;
3146 public NamespaceExpression (Namespace ns, Location loc)
3149 this.Type = InternalType.Namespace;
3150 this.eclass = ExprClass.Namespace;
3154 public Namespace Namespace {
3160 protected override Expression DoResolve (ResolveContext rc)
3162 throw new NotImplementedException ();
3165 public override FullNamedExpression ResolveAsTypeOrNamespace (IMemberContext mc, bool allowUnboundTypeArguments)
3170 public void Error_NamespaceDoesNotExist (IMemberContext ctx, string name, int arity, Location loc)
3172 var retval = Namespace.LookupType (ctx, name, arity, LookupMode.IgnoreAccessibility, loc);
3173 if (retval != null) {
3174 // ctx.Module.Compiler.Report.SymbolRelatedToPreviousError (retval.MemberDefinition);
3175 ErrorIsInaccesible (ctx, retval.GetSignatureForError (), loc);
3179 retval = Namespace.LookupType (ctx, name, -System.Math.Max (1, arity), LookupMode.Probing, loc);
3180 if (retval != null) {
3181 Error_TypeArgumentsCannotBeUsed (ctx, retval, loc);
3186 if (arity > 0 && Namespace.TryGetNamespace (name, out ns)) {
3187 Error_TypeArgumentsCannotBeUsed (ctx, ExprClassName, ns.GetSignatureForError (), loc);
3191 string assembly = null;
3192 string possible_name = Namespace.GetSignatureForError () + "." + name;
3194 // Only assembly unique name should be added
3195 switch (possible_name) {
3196 case "System.Drawing":
3197 case "System.Web.Services":
3200 case "System.Configuration":
3201 case "System.Data.Services":
3202 case "System.DirectoryServices":
3204 case "System.Net.Http":
3205 case "System.Numerics":
3206 case "System.Runtime.Caching":
3207 case "System.ServiceModel":
3208 case "System.Transactions":
3209 case "System.Web.Routing":
3210 case "System.Xml.Linq":
3212 assembly = possible_name;
3216 case "System.Linq.Expressions":
3217 assembly = "System.Core";
3220 case "System.Windows.Forms":
3221 case "System.Windows.Forms.Layout":
3222 assembly = "System.Windows.Forms";
3226 assembly = assembly == null ? "an" : "`" + assembly + "'";
3228 if (Namespace is GlobalRootNamespace) {
3229 ctx.Module.Compiler.Report.Error (400, loc,
3230 "The type or namespace name `{0}' could not be found in the global namespace. Are you missing {1} assembly reference?",
3233 ctx.Module.Compiler.Report.Error (234, loc,
3234 "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing {2} assembly reference?",
3235 name, GetSignatureForError (), assembly);
3239 public override string GetSignatureForError ()
3241 return ns.GetSignatureForError ();
3244 public FullNamedExpression LookupTypeOrNamespace (IMemberContext ctx, string name, int arity, LookupMode mode, Location loc)
3246 return ns.LookupTypeOrNamespace (ctx, name, arity, mode, loc);
3249 public override string ToString ()
3251 return Namespace.Name;
3256 /// This class denotes an expression which evaluates to a member
3257 /// of a struct or a class.
3259 public abstract class MemberExpr : Expression, OverloadResolver.IInstanceQualifier
3261 protected bool conditional_access_receiver;
3264 // An instance expression associated with this member, if it's a
3265 // non-static member
3267 public Expression InstanceExpression;
3270 /// The name of this member.
3272 public abstract string Name {
3277 // When base.member is used
3279 public bool IsBase {
3280 get { return InstanceExpression is BaseThis; }
3284 /// Whether this is an instance member.
3286 public abstract bool IsInstance {
3291 /// Whether this is a static member.
3293 public abstract bool IsStatic {
3297 public abstract string KindName {
3301 public bool ConditionalAccess { get; set; }
3303 protected abstract TypeSpec DeclaringType {
3307 TypeSpec OverloadResolver.IInstanceQualifier.InstanceType {
3309 return InstanceExpression.Type;
3314 // Converts best base candidate for virtual method starting from QueriedBaseType
3316 protected MethodSpec CandidateToBaseOverride (ResolveContext rc, MethodSpec method)
3319 // Only when base.member is used and method is virtual
3325 // Overload resulution works on virtual or non-virtual members only (no overrides). That
3326 // means for base.member access we have to find the closest match after we found best candidate
3328 if ((method.Modifiers & (Modifiers.ABSTRACT | Modifiers.VIRTUAL | Modifiers.OVERRIDE)) != 0) {
3330 // The method could already be what we are looking for
3332 TypeSpec[] targs = null;
3333 if (method.DeclaringType != InstanceExpression.Type) {
3335 // Candidate can have inflated MVAR parameters and we need to find
3336 // base match for original definition not inflated parameter types
3338 var parameters = method.Parameters;
3339 if (method.Arity > 0) {
3340 parameters = ((IParametersMember) method.MemberDefinition).Parameters;
3341 var inflated = method.DeclaringType as InflatedTypeSpec;
3342 if (inflated != null) {
3343 parameters = parameters.Inflate (inflated.CreateLocalInflator (rc));
3347 var filter = new MemberFilter (method.Name, method.Arity, MemberKind.Method, parameters, null);
3348 var base_override = MemberCache.FindMember (InstanceExpression.Type, filter, BindingRestriction.InstanceOnly | BindingRestriction.OverrideOnly) as MethodSpec;
3349 if (base_override != null && base_override.DeclaringType != method.DeclaringType) {
3350 if (base_override.IsGeneric)
3351 targs = method.TypeArguments;
3353 method = base_override;
3358 // When base access is used inside anonymous method/iterator/etc we need to
3359 // get back to the context of original type. We do it by emiting proxy
3360 // method in original class and rewriting base call to this compiler
3361 // generated method call which does the actual base invocation. This may
3362 // introduce redundant storey but with `this' only but it's tricky to avoid
3363 // at this stage as we don't know what expressions follow base
3365 // TODO: It's needed only when the method with base call is moved to a storey
3367 if (rc.CurrentAnonymousMethod != null) {
3368 if (targs == null && method.IsGeneric) {
3369 targs = method.TypeArguments;
3370 method = method.GetGenericMethodDefinition ();
3373 if (method.Parameters.HasArglist)
3374 throw new NotImplementedException ("__arglist base call proxy");
3376 method = rc.CurrentMemberDefinition.Parent.PartialContainer.CreateHoistedBaseCallProxy (rc, method);
3378 // Ideally this should apply to any proxy rewrite but in the case of unary mutators on
3379 // get/set member expressions second call would fail to proxy because left expression
3380 // would be of 'this' and not 'base' because we share InstanceExpression for get/set
3381 // FIXME: The async check is another hack but will probably fail with mutators
3382 if (rc.CurrentType.IsStruct || rc.CurrentAnonymousMethod.Storey is AsyncTaskStorey)
3383 InstanceExpression = new This (loc).Resolve (rc);
3387 method = method.MakeGenericMethod (rc, targs);
3391 // Only base will allow this invocation to happen.
3393 if (method.IsAbstract) {
3394 rc.Report.SymbolRelatedToPreviousError (method);
3395 Error_CannotCallAbstractBase (rc, method.GetSignatureForError ());
3401 protected void CheckProtectedMemberAccess (ResolveContext rc, MemberSpec member)
3403 if (InstanceExpression == null)
3406 if ((member.Modifiers & Modifiers.PROTECTED) != 0 && !(InstanceExpression is This)) {
3407 if (!CheckProtectedMemberAccess (rc, member, InstanceExpression.Type)) {
3408 Error_ProtectedMemberAccess (rc, member, InstanceExpression.Type, loc);
3413 bool OverloadResolver.IInstanceQualifier.CheckProtectedMemberAccess (ResolveContext rc, MemberSpec member)
3415 if (InstanceExpression == null)
3418 return InstanceExpression is This || CheckProtectedMemberAccess (rc, member, InstanceExpression.Type);
3421 public static bool CheckProtectedMemberAccess<T> (ResolveContext rc, T member, TypeSpec qualifier) where T : MemberSpec
3423 var ct = rc.CurrentType;
3424 if (ct == qualifier)
3427 if ((member.Modifiers & Modifiers.INTERNAL) != 0 && member.DeclaringType.MemberDefinition.IsInternalAsPublic (ct.MemberDefinition.DeclaringAssembly))
3430 qualifier = qualifier.GetDefinition ();
3431 if (ct != qualifier && !IsSameOrBaseQualifier (ct, qualifier)) {
3438 public override bool ContainsEmitWithAwait ()
3440 return InstanceExpression != null && InstanceExpression.ContainsEmitWithAwait ();
3443 public override bool HasConditionalAccess ()
3445 return ConditionalAccess || (InstanceExpression != null && InstanceExpression.HasConditionalAccess ());
3448 static bool IsSameOrBaseQualifier (TypeSpec type, TypeSpec qtype)
3451 type = type.GetDefinition ();
3453 if (type == qtype || TypeManager.IsFamilyAccessible (qtype, type))
3456 type = type.DeclaringType;
3457 } while (type != null);
3462 protected void DoBestMemberChecks<T> (ResolveContext rc, T member) where T : MemberSpec, IInterfaceMemberSpec
3464 if (InstanceExpression != null) {
3465 InstanceExpression = InstanceExpression.Resolve (rc);
3466 CheckProtectedMemberAccess (rc, member);
3469 if (member.MemberType.IsPointer) {
3470 if (rc.CurrentIterator != null) {
3471 UnsafeInsideIteratorError (rc, loc);
3472 } else if (!rc.IsUnsafe) {
3473 UnsafeError (rc, loc);
3477 var dep = member.GetMissingDependencies ();
3479 ImportedTypeDefinition.Error_MissingDependency (rc, dep, loc);
3482 member.CheckObsoleteness (rc, loc);
3484 if (!(member is FieldSpec))
3485 member.MemberDefinition.SetIsUsed ();
3488 protected virtual void Error_CannotCallAbstractBase (ResolveContext rc, string name)
3490 rc.Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
3493 public static void Error_ProtectedMemberAccess (ResolveContext rc, MemberSpec member, TypeSpec qualifier, Location loc)
3495 rc.Report.SymbolRelatedToPreviousError (member);
3496 rc.Report.Error (1540, loc,
3497 "Cannot access protected member `{0}' via a qualifier of type `{1}'. The qualifier must be of type `{2}' or derived from it",
3498 member.GetSignatureForError (), qualifier.GetSignatureForError (), rc.CurrentType.GetSignatureForError ());
3501 public override void FlowAnalysis (FlowAnalysisContext fc)
3503 if (InstanceExpression != null) {
3504 InstanceExpression.FlowAnalysis (fc);
3508 protected void ResolveConditionalAccessReceiver (ResolveContext rc)
3510 if (!rc.HasSet (ResolveContext.Options.DontSetConditionalAccessReceiver) && HasConditionalAccess ()) {
3511 conditional_access_receiver = true;
3515 public bool ResolveInstanceExpression (ResolveContext rc, Expression rhs)
3517 if (!ResolveInstanceExpressionCore (rc, rhs))
3521 // Check intermediate value modification which won't have any effect
3523 if (rhs != null && TypeSpec.IsValueType (InstanceExpression.Type)) {
3524 var fexpr = InstanceExpression as FieldExpr;
3525 if (fexpr != null) {
3526 if (!fexpr.Spec.IsReadOnly || rc.HasAny (ResolveContext.Options.FieldInitializerScope | ResolveContext.Options.ConstructorScope))
3529 if (fexpr.IsStatic) {
3530 rc.Report.Error (1650, loc, "Fields of static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
3531 fexpr.GetSignatureForError ());
3533 rc.Report.Error (1648, loc, "Members of readonly field `{0}' cannot be modified (except in a constructor or a variable initializer)",
3534 fexpr.GetSignatureForError ());
3540 if (InstanceExpression is PropertyExpr || InstanceExpression is IndexerExpr || InstanceExpression is Invocation) {
3541 if (rc.CurrentInitializerVariable != null) {
3542 rc.Report.Error (1918, loc, "Members of value type `{0}' cannot be assigned using a property `{1}' object initializer",
3543 InstanceExpression.Type.GetSignatureForError (), InstanceExpression.GetSignatureForError ());
3545 rc.Report.Error (1612, loc,
3546 "Cannot modify a value type return value of `{0}'. Consider storing the value in a temporary variable",
3547 InstanceExpression.GetSignatureForError ());
3553 var lvr = InstanceExpression as LocalVariableReference;
3556 if (!lvr.local_info.IsReadonly)
3559 rc.Report.Error (1654, loc, "Cannot assign to members of `{0}' because it is a `{1}'",
3560 InstanceExpression.GetSignatureForError (), lvr.local_info.GetReadOnlyContext ());
3567 bool ResolveInstanceExpressionCore (ResolveContext rc, Expression rhs)
3570 if (InstanceExpression != null) {
3571 if (InstanceExpression is TypeExpr) {
3572 var t = InstanceExpression.Type;
3574 t.CheckObsoleteness (rc, loc);
3576 t = t.DeclaringType;
3577 } while (t != null);
3579 var runtime_expr = InstanceExpression as RuntimeValueExpression;
3580 if (runtime_expr == null || !runtime_expr.IsSuggestionOnly) {
3581 rc.Report.Error (176, loc,
3582 "Static member `{0}' cannot be accessed with an instance reference, qualify it with a type name instead",
3583 GetSignatureForError ());
3587 InstanceExpression = null;
3593 if (InstanceExpression == null || InstanceExpression is TypeExpr) {
3594 if (InstanceExpression != null || !This.IsThisAvailable (rc, true)) {
3595 if (rc.HasSet (ResolveContext.Options.FieldInitializerScope)) {
3596 rc.Report.Error (236, loc,
3597 "A field initializer cannot reference the nonstatic field, method, or property `{0}'",
3598 GetSignatureForError ());
3600 var fe = this as FieldExpr;
3601 if (fe != null && fe.Spec.MemberDefinition is PrimaryConstructorField) {
3602 if (rc.HasSet (ResolveContext.Options.BaseInitializer)) {
3603 rc.Report.Error (9005, loc, "Constructor initializer cannot access primary constructor parameters");
3605 rc.Report.Error (9006, loc, "An object reference is required to access primary constructor parameter `{0}'",
3609 rc.Report.Error (120, loc,
3610 "An object reference is required to access non-static member `{0}'",
3611 GetSignatureForError ());
3615 InstanceExpression = new CompilerGeneratedThis (rc.CurrentType, loc).Resolve (rc);
3619 if (!TypeManager.IsFamilyAccessible (rc.CurrentType, DeclaringType)) {
3620 rc.Report.Error (38, loc,
3621 "Cannot access a nonstatic member of outer type `{0}' via nested type `{1}'",
3622 DeclaringType.GetSignatureForError (), rc.CurrentType.GetSignatureForError ());
3625 InstanceExpression = new This (loc).Resolve (rc);
3629 var me = InstanceExpression as MemberExpr;
3631 me.ResolveInstanceExpressionCore (rc, rhs);
3633 var fe = me as FieldExpr;
3634 if (fe != null && fe.IsMarshalByRefAccess (rc)) {
3635 rc.Report.SymbolRelatedToPreviousError (me.DeclaringType);
3636 rc.Report.Warning (1690, 1, loc,
3637 "Cannot call methods, properties, or indexers on `{0}' because it is a value type member of a marshal-by-reference class",
3638 me.GetSignatureForError ());
3645 // Additional checks for l-value member access
3648 if (InstanceExpression is UnboxCast) {
3649 rc.Report.Error (445, InstanceExpression.Location, "Cannot modify the result of an unboxing conversion");
3656 public virtual MemberExpr ResolveMemberAccess (ResolveContext ec, Expression left, SimpleName original)
3658 if (left != null && !ConditionalAccess && !ec.HasSet (ResolveContext.Options.NameOfScope) && left.IsNull && TypeSpec.IsReferenceType (left.Type)) {
3659 ec.Report.Warning (1720, 1, left.Location,
3660 "Expression will always cause a `{0}'", "System.NullReferenceException");
3663 InstanceExpression = left;
3667 public virtual void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
3672 protected void EmitInstance (EmitContext ec, bool prepare_for_load)
3674 var inst = new InstanceEmitter (InstanceExpression, TypeSpec.IsValueType (InstanceExpression.Type));
3675 inst.Emit (ec, ConditionalAccess);
3677 if (prepare_for_load)
3678 ec.Emit (OpCodes.Dup);
3681 public abstract void SetTypeArguments (ResolveContext ec, TypeArguments ta);
3684 public class ExtensionMethodCandidates
3686 readonly NamespaceContainer container;
3687 readonly IList<MethodSpec> methods;
3689 readonly IMemberContext context;
3691 public ExtensionMethodCandidates (IMemberContext context, IList<MethodSpec> methods, NamespaceContainer nsContainer, int lookupIndex)
3693 this.context = context;
3694 this.methods = methods;
3695 this.container = nsContainer;
3696 this.index = lookupIndex;
3699 public NamespaceContainer Container {
3705 public IMemberContext Context {
3711 public int LookupIndex {
3717 public IList<MethodSpec> Methods {
3725 // Represents a group of extension method candidates for whole namespace
3727 class ExtensionMethodGroupExpr : MethodGroupExpr, OverloadResolver.IErrorHandler
3729 ExtensionMethodCandidates candidates;
3730 public Expression ExtensionExpression;
3732 public ExtensionMethodGroupExpr (ExtensionMethodCandidates candidates, Expression extensionExpr, Location loc)
3733 : base (candidates.Methods.Cast<MemberSpec>().ToList (), extensionExpr.Type, loc)
3735 this.candidates = candidates;
3736 this.ExtensionExpression = extensionExpr;
3739 public override bool IsStatic {
3740 get { return true; }
3744 // For extension methodgroup we are not looking for base members but parent
3745 // namespace extension methods
3747 public override IList<MemberSpec> GetBaseMembers (TypeSpec type)
3749 // TODO: candidates are null only when doing error reporting, that's
3750 // incorrect. We have to discover same extension methods in error mode
3751 if (candidates == null)
3754 int arity = type_arguments == null ? 0 : type_arguments.Count;
3756 candidates = candidates.Container.LookupExtensionMethod (candidates.Context, Name, arity, candidates.LookupIndex);
3757 if (candidates == null)
3760 return candidates.Methods.Cast<MemberSpec> ().ToList ();
3763 public static bool IsExtensionTypeCompatible (TypeSpec argType, TypeSpec extensionType)
3766 // Indentity, implicit reference or boxing conversion must exist for the extension parameter
3768 // LAMESPEC: or implicit type parameter conversion
3770 return argType == extensionType ||
3771 TypeSpecComparer.IsEqual (argType, extensionType) ||
3772 Convert.ImplicitReferenceConversionExists (argType, extensionType, false) ||
3773 Convert.ImplicitBoxingConversion (null, argType, extensionType) != null;
3776 public override void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
3778 rc.Report.Error (8093, expr.Location, "An argument to nameof operator cannot be extension method group");
3781 public override MethodGroupExpr LookupExtensionMethod (ResolveContext rc)
3783 // We are already here
3787 public override MethodGroupExpr OverloadResolve (ResolveContext ec, ref Arguments arguments, OverloadResolver.IErrorHandler ehandler, OverloadResolver.Restrictions restr)
3789 if (arguments == null)
3790 arguments = new Arguments (1);
3792 ExtensionExpression = ExtensionExpression.Resolve (ec);
3793 if (ExtensionExpression == null)
3796 var cand = candidates;
3797 var atype = ConditionalAccess ? Argument.AType.ExtensionTypeConditionalAccess : Argument.AType.ExtensionType;
3798 arguments.Insert (0, new Argument (ExtensionExpression, atype));
3799 var res = base.OverloadResolve (ec, ref arguments, ehandler ?? this, restr);
3801 // Restore candidates in case we are running in probing mode
3804 // Store resolved argument and restore original arguments
3806 // Clean-up modified arguments for error reporting
3807 arguments.RemoveAt (0);
3811 var me = ExtensionExpression as MemberExpr;
3813 me.ResolveInstanceExpression (ec, null);
3814 var fe = me as FieldExpr;
3816 fe.Spec.MemberDefinition.SetIsUsed ();
3819 InstanceExpression = null;
3823 #region IErrorHandler Members
3825 bool OverloadResolver.IErrorHandler.AmbiguousCandidates (ResolveContext rc, MemberSpec best, MemberSpec ambiguous)
3830 bool OverloadResolver.IErrorHandler.ArgumentMismatch (ResolveContext rc, MemberSpec best, Argument arg, int index)
3832 rc.Report.SymbolRelatedToPreviousError (best);
3835 rc.Report.Error (1929, loc,
3836 "Type `{0}' does not contain a member `{1}' and the best extension method overload `{2}' requires an instance of type `{3}'",
3837 queried_type.GetSignatureForError (), Name, best.GetSignatureForError (), ((MethodSpec)best).Parameters.ExtensionMethodType.GetSignatureForError ());
3839 rc.Report.Error (1928, loc,
3840 "Type `{0}' does not contain a member `{1}' and the best extension method overload `{2}' has some invalid arguments",
3841 queried_type.GetSignatureForError (), Name, best.GetSignatureForError ());
3847 bool OverloadResolver.IErrorHandler.NoArgumentMatch (ResolveContext rc, MemberSpec best)
3852 bool OverloadResolver.IErrorHandler.TypeInferenceFailed (ResolveContext rc, MemberSpec best)
3861 /// MethodGroupExpr represents a group of method candidates which
3862 /// can be resolved to the best method overload
3864 public class MethodGroupExpr : MemberExpr, OverloadResolver.IBaseMembersProvider
3866 static readonly MemberSpec[] Excluded = new MemberSpec[0];
3868 protected IList<MemberSpec> Methods;
3869 MethodSpec best_candidate;
3870 TypeSpec best_candidate_return;
3871 protected TypeArguments type_arguments;
3873 SimpleName simple_name;
3874 protected TypeSpec queried_type;
3876 public MethodGroupExpr (IList<MemberSpec> mi, TypeSpec type, Location loc)
3880 this.type = InternalType.MethodGroup;
3882 eclass = ExprClass.MethodGroup;
3883 queried_type = type;
3886 public MethodGroupExpr (MethodSpec m, TypeSpec type, Location loc)
3887 : this (new MemberSpec[] { m }, type, loc)
3893 public MethodSpec BestCandidate {
3895 return best_candidate;
3899 public TypeSpec BestCandidateReturnType {
3901 return best_candidate_return;
3905 public IList<MemberSpec> Candidates {
3911 protected override TypeSpec DeclaringType {
3913 return queried_type;
3917 public bool IsConditionallyExcluded {
3919 return Methods == Excluded;
3923 public override bool IsInstance {
3925 if (best_candidate != null)
3926 return !best_candidate.IsStatic;
3932 public override bool IsSideEffectFree {
3934 return InstanceExpression == null || InstanceExpression.IsSideEffectFree;
3938 public override bool IsStatic {
3940 if (best_candidate != null)
3941 return best_candidate.IsStatic;
3947 public override string KindName {
3948 get { return "method"; }
3951 public override string Name {
3953 if (best_candidate != null)
3954 return best_candidate.Name;
3957 return Methods.First ().Name;
3964 // When best candidate is already know this factory can be used
3965 // to avoid expensive overload resolution to be called
3967 // NOTE: InstanceExpression has to be set manually
3969 public static MethodGroupExpr CreatePredefined (MethodSpec best, TypeSpec queriedType, Location loc)
3971 return new MethodGroupExpr (best, queriedType, loc) {
3972 best_candidate = best,
3973 best_candidate_return = best.ReturnType
3977 public override string GetSignatureForError ()
3979 if (best_candidate != null)
3980 return best_candidate.GetSignatureForError ();
3982 return Methods.First ().GetSignatureForError ();
3985 public override Expression CreateExpressionTree (ResolveContext ec)
3987 if (best_candidate == null) {
3988 ec.Report.Error (1953, loc, "An expression tree cannot contain an expression with method group");
3992 if (IsConditionallyExcluded)
3993 ec.Report.Error (765, loc,
3994 "Partial methods with only a defining declaration or removed conditional methods cannot be used in an expression tree");
3996 if (ConditionalAccess)
3997 Error_NullShortCircuitInsideExpressionTree (ec);
3999 return new TypeOfMethod (best_candidate, loc);
4002 protected override Expression DoResolve (ResolveContext ec)
4004 this.eclass = ExprClass.MethodGroup;
4006 if (InstanceExpression != null) {
4007 InstanceExpression = InstanceExpression.Resolve (ec);
4008 if (InstanceExpression == null)
4015 public override void Emit (EmitContext ec)
4017 throw new NotSupportedException ();
4020 public void EmitCall (EmitContext ec, Arguments arguments, bool statement)
4022 var call = new CallEmitter ();
4023 call.InstanceExpression = InstanceExpression;
4024 call.ConditionalAccess = ConditionalAccess;
4027 call.EmitStatement (ec, best_candidate, arguments, loc);
4029 call.Emit (ec, best_candidate, arguments, loc);
4032 public void EmitCall (EmitContext ec, Arguments arguments, TypeSpec conditionalAccessReceiver, bool statement)
4034 var ca = ec.ConditionalAccess;
4035 ec.ConditionalAccess = new ConditionalAccessContext (conditionalAccessReceiver, ec.DefineLabel ()) {
4036 Statement = statement
4039 EmitCall (ec, arguments, statement);
4041 ec.CloseConditionalAccess (!statement && best_candidate_return != conditionalAccessReceiver && conditionalAccessReceiver.IsNullableType ? conditionalAccessReceiver : null);
4042 ec.ConditionalAccess = ca;
4045 public override void Error_ValueCannotBeConverted (ResolveContext ec, TypeSpec target, bool expl)
4047 if (target != InternalType.ErrorType) {
4048 ec.Report.Error (428, loc, "Cannot convert method group `{0}' to non-delegate type `{1}'. Consider using parentheses to invoke the method",
4049 Name, target.GetSignatureForError ());
4053 public bool HasAccessibleCandidate (ResolveContext rc)
4055 foreach (var candidate in Candidates) {
4056 if (candidate.IsAccessible (rc))
4063 public static bool IsExtensionMethodArgument (Expression expr)
4066 // LAMESPEC: No details about which expressions are not allowed
4068 return !(expr is TypeExpr) && !(expr is BaseThis);
4072 /// Find the Applicable Function Members (7.4.2.1)
4074 /// me: Method Group expression with the members to select.
4075 /// it might contain constructors or methods (or anything
4076 /// that maps to a method).
4078 /// Arguments: ArrayList containing resolved Argument objects.
4080 /// loc: The location if we want an error to be reported, or a Null
4081 /// location for "probing" purposes.
4083 /// Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
4084 /// that is the best match of me on Arguments.
4087 public virtual MethodGroupExpr OverloadResolve (ResolveContext ec, ref Arguments args, OverloadResolver.IErrorHandler cerrors, OverloadResolver.Restrictions restr)
4089 // TODO: causes issues with probing mode, remove explicit Kind check
4090 if (best_candidate != null && best_candidate.Kind == MemberKind.Destructor)
4093 var r = new OverloadResolver (Methods, type_arguments, restr, loc);
4094 if ((restr & OverloadResolver.Restrictions.NoBaseMembers) == 0) {
4095 r.BaseMembersProvider = this;
4096 r.InstanceQualifier = this;
4099 if (cerrors != null)
4100 r.CustomErrors = cerrors;
4102 // TODO: When in probing mode do IsApplicable only and when called again do VerifyArguments for full error reporting
4103 best_candidate = r.ResolveMember<MethodSpec> (ec, ref args);
4104 if (best_candidate == null) {
4105 if (!r.BestCandidateIsDynamic)
4108 if (simple_name != null && ec.IsStatic)
4109 InstanceExpression = ProbeIdenticalTypeName (ec, InstanceExpression, simple_name);
4114 // Overload resolver had to create a new method group, all checks bellow have already been executed
4115 if (r.BestCandidateNewMethodGroup != null)
4116 return r.BestCandidateNewMethodGroup;
4118 if (best_candidate.Kind == MemberKind.Method && (restr & OverloadResolver.Restrictions.ProbingOnly) == 0) {
4119 if (InstanceExpression != null) {
4120 if (best_candidate.IsExtensionMethod && args[0].Expr == InstanceExpression) {
4121 InstanceExpression = null;
4123 if (simple_name != null && best_candidate.IsStatic) {
4124 InstanceExpression = ProbeIdenticalTypeName (ec, InstanceExpression, simple_name);
4127 InstanceExpression.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup | ResolveFlags.Type);
4131 ResolveInstanceExpression (ec, null);
4134 var base_override = CandidateToBaseOverride (ec, best_candidate);
4135 if (base_override == best_candidate) {
4136 best_candidate_return = r.BestCandidateReturnType;
4138 best_candidate = base_override;
4139 best_candidate_return = best_candidate.ReturnType;
4142 if (best_candidate.IsGeneric && (restr & OverloadResolver.Restrictions.ProbingOnly) == 0 && TypeParameterSpec.HasAnyTypeParameterConstrained (best_candidate.GenericDefinition)) {
4143 ConstraintChecker cc = new ConstraintChecker (ec);
4144 cc.CheckAll (best_candidate.GetGenericMethodDefinition (), best_candidate.TypeArguments, best_candidate.Constraints, loc);
4148 // Additional check for possible imported base override method which
4149 // could not be done during IsOverrideMethodBaseTypeAccessible
4151 if (best_candidate.IsVirtual && (best_candidate.DeclaringType.Modifiers & Modifiers.PROTECTED) != 0 &&
4152 best_candidate.MemberDefinition.IsImported && !best_candidate.DeclaringType.IsAccessible (ec)) {
4153 ec.Report.SymbolRelatedToPreviousError (best_candidate);
4154 ErrorIsInaccesible (ec, best_candidate.GetSignatureForError (), loc);
4157 // Speed up the check by not doing it on disallowed targets
4158 if (best_candidate_return.Kind == MemberKind.Void && best_candidate.IsConditionallyExcluded (ec))
4164 public override MemberExpr ResolveMemberAccess (ResolveContext ec, Expression left, SimpleName original)
4166 var fe = left as FieldExpr;
4169 // Using method-group on struct fields makes the struct assigned. I am not sure
4170 // why but that's what .net does
4172 fe.Spec.MemberDefinition.SetIsAssigned ();
4175 simple_name = original;
4176 return base.ResolveMemberAccess (ec, left, original);
4179 public override void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
4181 if (!HasAccessibleCandidate (rc)) {
4182 ErrorIsInaccesible (rc, expr.GetSignatureForError (), loc);
4185 if (expr.HasTypeArguments) {
4186 rc.Report.Error (8084, expr.Location, "An argument to nameof operator cannot be method group with type arguments");
4190 public override void SetTypeArguments (ResolveContext ec, TypeArguments ta)
4192 type_arguments = ta;
4195 #region IBaseMembersProvider Members
4197 public virtual IList<MemberSpec> GetBaseMembers (TypeSpec type)
4199 var baseType = type.BaseType;
4201 IList<MemberSpec> members = baseType == null ? null : MemberCache.FindMembers (baseType, Methods [0].Name, false);
4203 if (members == null && !type.IsInterface) {
4204 var tps = queried_type as TypeParameterSpec;
4206 members = MemberCache.FindInterfaceMembers (tps, Methods [0].Name);
4212 public IParametersMember GetOverrideMemberParameters (MemberSpec member)
4214 if (queried_type == member.DeclaringType)
4217 return MemberCache.FindMember (queried_type, new MemberFilter ((MethodSpec) member),
4218 BindingRestriction.InstanceOnly | BindingRestriction.OverrideOnly) as IParametersMember;
4222 // Extension methods lookup after ordinary methods candidates failed to apply
4224 public virtual MethodGroupExpr LookupExtensionMethod (ResolveContext rc)
4226 if (InstanceExpression == null || InstanceExpression.eclass == ExprClass.Type)
4229 if (!IsExtensionMethodArgument (InstanceExpression))
4232 int arity = type_arguments == null ? 0 : type_arguments.Count;
4233 var methods = rc.LookupExtensionMethod (Methods[0].Name, arity);
4234 if (methods == null)
4237 var emg = new ExtensionMethodGroupExpr (methods, InstanceExpression, loc);
4238 emg.SetTypeArguments (rc, type_arguments);
4239 emg.ConditionalAccess = ConditionalAccess;
4246 struct ConstructorInstanceQualifier : OverloadResolver.IInstanceQualifier
4248 public ConstructorInstanceQualifier (TypeSpec type)
4251 InstanceType = type;
4254 public TypeSpec InstanceType { get; private set; }
4256 public bool CheckProtectedMemberAccess (ResolveContext rc, MemberSpec member)
4258 return MemberExpr.CheckProtectedMemberAccess (rc, member, InstanceType);
4262 public struct OverloadResolver
4265 public enum Restrictions
4269 ProbingOnly = 1 << 1,
4270 CovariantDelegate = 1 << 2,
4271 NoBaseMembers = 1 << 3,
4272 BaseMembersIncluded = 1 << 4,
4273 GetEnumeratorLookup = 1 << 5
4276 public interface IBaseMembersProvider
4278 IList<MemberSpec> GetBaseMembers (TypeSpec baseType);
4279 IParametersMember GetOverrideMemberParameters (MemberSpec member);
4280 MethodGroupExpr LookupExtensionMethod (ResolveContext rc);
4283 public interface IErrorHandler
4285 bool AmbiguousCandidates (ResolveContext rc, MemberSpec best, MemberSpec ambiguous);
4286 bool ArgumentMismatch (ResolveContext rc, MemberSpec best, Argument a, int index);
4287 bool NoArgumentMatch (ResolveContext rc, MemberSpec best);
4288 bool TypeInferenceFailed (ResolveContext rc, MemberSpec best);
4291 public interface IInstanceQualifier
4293 TypeSpec InstanceType { get; }
4294 bool CheckProtectedMemberAccess (ResolveContext rc, MemberSpec member);
4297 sealed class NoBaseMembers : IBaseMembersProvider
4299 public static readonly IBaseMembersProvider Instance = new NoBaseMembers ();
4301 public IList<MemberSpec> GetBaseMembers (TypeSpec baseType)
4306 public IParametersMember GetOverrideMemberParameters (MemberSpec member)
4311 public MethodGroupExpr LookupExtensionMethod (ResolveContext rc)
4317 struct AmbiguousCandidate
4319 public readonly MemberSpec Member;
4320 public readonly bool Expanded;
4321 public readonly AParametersCollection Parameters;
4323 public AmbiguousCandidate (MemberSpec member, AParametersCollection parameters, bool expanded)
4326 Parameters = parameters;
4327 Expanded = expanded;
4332 IList<MemberSpec> members;
4333 TypeArguments type_arguments;
4334 IBaseMembersProvider base_provider;
4335 IErrorHandler custom_errors;
4336 IInstanceQualifier instance_qualifier;
4337 Restrictions restrictions;
4338 MethodGroupExpr best_candidate_extension_group;
4339 TypeSpec best_candidate_return_type;
4341 SessionReportPrinter lambda_conv_msgs;
4343 public OverloadResolver (IList<MemberSpec> members, Restrictions restrictions, Location loc)
4344 : this (members, null, restrictions, loc)
4348 public OverloadResolver (IList<MemberSpec> members, TypeArguments targs, Restrictions restrictions, Location loc)
4351 if (members == null || members.Count == 0)
4352 throw new ArgumentException ("empty members set");
4354 this.members = members;
4356 type_arguments = targs;
4357 this.restrictions = restrictions;
4358 if (IsDelegateInvoke)
4359 this.restrictions |= Restrictions.NoBaseMembers;
4361 base_provider = NoBaseMembers.Instance;
4366 public IBaseMembersProvider BaseMembersProvider {
4368 return base_provider;
4371 base_provider = value;
4375 public bool BestCandidateIsDynamic { get; set; }
4378 // Best candidate was found in newly created MethodGroupExpr, used by extension methods
4380 public MethodGroupExpr BestCandidateNewMethodGroup {
4382 return best_candidate_extension_group;
4387 // Return type can be different between best candidate and closest override
4389 public TypeSpec BestCandidateReturnType {
4391 return best_candidate_return_type;
4395 public IErrorHandler CustomErrors {
4397 return custom_errors;
4400 custom_errors = value;
4404 TypeSpec DelegateType {
4406 if ((restrictions & Restrictions.DelegateInvoke) == 0)
4407 throw new InternalErrorException ("Not running in delegate mode", loc);
4409 return members [0].DeclaringType;
4413 public IInstanceQualifier InstanceQualifier {
4415 return instance_qualifier;
4418 instance_qualifier = value;
4422 bool IsProbingOnly {
4424 return (restrictions & Restrictions.ProbingOnly) != 0;
4428 bool IsDelegateInvoke {
4430 return (restrictions & Restrictions.DelegateInvoke) != 0;
4437 // 7.4.3.3 Better conversion from expression
4438 // Returns : 1 if a->p is better,
4439 // 2 if a->q is better,
4440 // 0 if neither is better
4442 static int BetterExpressionConversion (ResolveContext ec, Argument a, TypeSpec p, TypeSpec q)
4444 TypeSpec argument_type = a.Type;
4447 // Exactly matching Expression phase
4451 // If argument is an anonymous function
4453 if (argument_type == InternalType.AnonymousMethod && ec.Module.Compiler.Settings.Version > LanguageVersion.ISO_2) {
4455 // p and q are delegate types or expression tree types
4457 if (p.IsExpressionTreeType || q.IsExpressionTreeType) {
4458 if (q.MemberDefinition != p.MemberDefinition) {
4463 // Uwrap delegate from Expression<T>
4465 q = TypeManager.GetTypeArguments (q) [0];
4466 p = TypeManager.GetTypeArguments (p) [0];
4469 var p_m = Delegate.GetInvokeMethod (p);
4470 var q_m = Delegate.GetInvokeMethod (q);
4473 // With identical parameter lists
4475 if (!TypeSpecComparer.Equals (p_m.Parameters.Types, q_m.Parameters.Types))
4483 // if p is void returning, and q has a return type Y, then C2 is the better conversion.
4485 if (p.Kind == MemberKind.Void) {
4486 return q.Kind != MemberKind.Void ? 2 : 0;
4490 // if p has a return type Y, and q is void returning, then C1 is the better conversion.
4492 if (q.Kind == MemberKind.Void) {
4493 return p.Kind != MemberKind.Void ? 1 : 0;
4496 var am = (AnonymousMethodExpression)a.Expr;
4499 // When anonymous method is an asynchronous, and P has a return type Task<Y1>, and Q has a return type Task<Y2>
4500 // better conversion is performed between underlying types Y1 and Y2
4502 if (p.IsGenericTask || q.IsGenericTask) {
4503 if (am.Block.IsAsync && p.IsGenericTask && q.IsGenericTask) {
4504 q = q.TypeArguments [0];
4505 p = p.TypeArguments [0];
4511 // An inferred return type X exists for E in the context of the parameter list, and
4512 // an identity conversion exists from X to the return type of D
4514 var inferred_type = am.InferReturnType (ec, null, orig_q);
4515 if (inferred_type != null) {
4516 if (inferred_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
4517 inferred_type = ec.BuiltinTypes.Object;
4519 if (inferred_type == p)
4522 if (inferred_type == q)
4528 if (argument_type == p)
4531 if (argument_type == q)
4534 return IsBetterConversionTarget (ec, p, q);
4537 static int IsBetterConversionTarget (ResolveContext rc, TypeSpec p, TypeSpec q)
4539 if ((p.Kind == MemberKind.Delegate || p.IsExpressionTreeType) && (q.Kind == MemberKind.Delegate || q.IsExpressionTreeType)) {
4541 if (p.Kind != MemberKind.Delegate) {
4542 p = TypeManager.GetTypeArguments (p) [0];
4545 if (q.Kind != MemberKind.Delegate) {
4546 q = TypeManager.GetTypeArguments (q) [0];
4549 var p_m = Delegate.GetInvokeMethod (p);
4550 var q_m = Delegate.GetInvokeMethod (q);
4556 // if p is void returning, and q has a return type Y, then C2 is the better conversion.
4558 if (p.Kind == MemberKind.Void) {
4559 return q.Kind != MemberKind.Void ? 2 : 0;
4563 // if p has a return type Y, and q is void returning, then C1 is the better conversion.
4565 if (q.Kind == MemberKind.Void) {
4566 return p.Kind != MemberKind.Void ? 1 : 0;
4569 return IsBetterConversionTarget (rc, p, q);
4572 if (p.IsGenericTask && q.IsGenericTask) {
4573 q = q.TypeArguments [0];
4574 p = p.TypeArguments [0];
4575 return IsBetterConversionTarget (rc, p, q);
4579 if (p.IsNullableType) {
4580 p = Nullable.NullableInfo.GetUnderlyingType (p);
4581 if (!BuiltinTypeSpec.IsPrimitiveTypeOrDecimal (p))
4582 return BetterTypeConversionImplicitConversion (rc, p_orig, q);
4585 // Spec expects implicit conversion check between p and q, q and p
4586 // to be done before nullable unwrapping but that's expensive operation.
4588 // Extra manual tweak is needed because BetterTypeConversion works on
4596 if (q.IsNullableType) {
4597 q = Nullable.NullableInfo.GetUnderlyingType (q);
4598 if (!BuiltinTypeSpec.IsPrimitiveTypeOrDecimal (q))
4599 return BetterTypeConversionImplicitConversion (rc, p_orig, q_orig);
4605 return BetterTypeConversion (rc, p, q);
4609 // 7.4.3.4 Better conversion from type
4611 public static int BetterTypeConversion (ResolveContext ec, TypeSpec p, TypeSpec q)
4613 if (p == null || q == null)
4614 throw new InternalErrorException ("BetterTypeConversion got a null conversion");
4616 switch (p.BuiltinType) {
4617 case BuiltinTypeSpec.Type.Int:
4618 if (q.BuiltinType == BuiltinTypeSpec.Type.UInt || q.BuiltinType == BuiltinTypeSpec.Type.ULong)
4621 case BuiltinTypeSpec.Type.Long:
4622 if (q.BuiltinType == BuiltinTypeSpec.Type.ULong)
4625 case BuiltinTypeSpec.Type.SByte:
4626 switch (q.BuiltinType) {
4627 case BuiltinTypeSpec.Type.Byte:
4628 case BuiltinTypeSpec.Type.UShort:
4629 case BuiltinTypeSpec.Type.UInt:
4630 case BuiltinTypeSpec.Type.ULong:
4634 case BuiltinTypeSpec.Type.Short:
4635 switch (q.BuiltinType) {
4636 case BuiltinTypeSpec.Type.UShort:
4637 case BuiltinTypeSpec.Type.UInt:
4638 case BuiltinTypeSpec.Type.ULong:
4642 case BuiltinTypeSpec.Type.Dynamic:
4643 // LAMESPEC: Dynamic conversions is not considered
4644 p = ec.Module.Compiler.BuiltinTypes.Object;
4648 switch (q.BuiltinType) {
4649 case BuiltinTypeSpec.Type.Int:
4650 if (p.BuiltinType == BuiltinTypeSpec.Type.UInt || p.BuiltinType == BuiltinTypeSpec.Type.ULong)
4653 case BuiltinTypeSpec.Type.Long:
4654 if (p.BuiltinType == BuiltinTypeSpec.Type.ULong)
4657 case BuiltinTypeSpec.Type.SByte:
4658 switch (p.BuiltinType) {
4659 case BuiltinTypeSpec.Type.Byte:
4660 case BuiltinTypeSpec.Type.UShort:
4661 case BuiltinTypeSpec.Type.UInt:
4662 case BuiltinTypeSpec.Type.ULong:
4666 case BuiltinTypeSpec.Type.Short:
4667 switch (p.BuiltinType) {
4668 case BuiltinTypeSpec.Type.UShort:
4669 case BuiltinTypeSpec.Type.UInt:
4670 case BuiltinTypeSpec.Type.ULong:
4674 case BuiltinTypeSpec.Type.Dynamic:
4675 // LAMESPEC: Dynamic conversions is not considered
4676 q = ec.Module.Compiler.BuiltinTypes.Object;
4680 return BetterTypeConversionImplicitConversion (ec, p, q);
4683 static int BetterTypeConversionImplicitConversion (ResolveContext rc, TypeSpec p, TypeSpec q)
4685 // TODO: this is expensive
4686 Expression p_tmp = new EmptyExpression (p);
4687 Expression q_tmp = new EmptyExpression (q);
4689 bool p_to_q = Convert.ImplicitConversionExists (rc, p_tmp, q);
4690 bool q_to_p = Convert.ImplicitConversionExists (rc, q_tmp, p);
4692 if (p_to_q && !q_to_p)
4695 if (q_to_p && !p_to_q)
4702 /// Determines "Better function" between candidate
4703 /// and the current best match
4706 /// Returns a boolean indicating :
4707 /// false if candidate ain't better
4708 /// true if candidate is better than the current best match
4710 bool BetterFunction (ResolveContext ec, Arguments args, MemberSpec candidate, AParametersCollection cparam, bool candidate_params,
4711 MemberSpec best, AParametersCollection bparam, bool best_params)
4713 AParametersCollection candidate_pd = ((IParametersMember) candidate).Parameters;
4714 AParametersCollection best_pd = ((IParametersMember) best).Parameters;
4716 int candidate_better_count = 0;
4717 int best_better_count = 0;
4719 bool are_equivalent = true;
4720 int args_count = args == null ? 0 : args.Count;
4724 for (int c_idx = 0, b_idx = 0; j < args_count; ++j, ++c_idx, ++b_idx) {
4727 // Default arguments are ignored for better decision
4728 if (a.IsDefaultArgument)
4732 // When comparing named argument the parameter type index has to be looked up
4733 // in original parameter set (override version for virtual members)
4735 NamedArgument na = a as NamedArgument;
4737 int idx = cparam.GetParameterIndexByName (na.Name);
4738 ct = candidate_pd.Types[idx];
4739 if (candidate_params && candidate_pd.FixedParameters[idx].ModFlags == Parameter.Modifier.PARAMS)
4740 ct = TypeManager.GetElementType (ct);
4742 idx = bparam.GetParameterIndexByName (na.Name);
4743 bt = best_pd.Types[idx];
4744 if (best_params && best_pd.FixedParameters[idx].ModFlags == Parameter.Modifier.PARAMS)
4745 bt = TypeManager.GetElementType (bt);
4747 ct = candidate_pd.Types[c_idx];
4748 bt = best_pd.Types[b_idx];
4750 if (candidate_params && candidate_pd.FixedParameters[c_idx].ModFlags == Parameter.Modifier.PARAMS) {
4751 ct = TypeManager.GetElementType (ct);
4755 if (best_params && best_pd.FixedParameters[b_idx].ModFlags == Parameter.Modifier.PARAMS) {
4756 bt = TypeManager.GetElementType (bt);
4761 if (TypeSpecComparer.IsEqual (ct, bt))
4764 are_equivalent = false;
4765 int result = BetterExpressionConversion (ec, a, ct, bt);
4767 // for each argument, the conversion to 'ct' should be no worse than
4768 // the conversion to 'bt'.
4771 // No optional parameters tie breaking rules for delegates overload resolution
4773 if ((restrictions & Restrictions.CovariantDelegate) != 0)
4776 ++best_better_count;
4780 // for at least one argument, the conversion to 'ct' should be better than
4781 // the conversion to 'bt'.
4783 ++candidate_better_count;
4786 if (candidate_better_count != 0 && best_better_count == 0)
4789 if (best_better_count > 0 && candidate_better_count == 0)
4793 // LAMESPEC: Tie-breaking rules for not equivalent parameter types
4795 if (!are_equivalent) {
4796 while (j < args_count && !args [j++].IsDefaultArgument) ;
4799 // A candidate with no default parameters is still better when there
4800 // is no better expression conversion and does not have more parameters
4802 if (candidate_pd.Count < best_pd.Count) {
4803 if (candidate_params)
4806 if (!candidate_pd.FixedParameters [j - 1].HasDefaultValue)
4809 if (best_pd.FixedParameters [j].HasDefaultValue)
4812 } else if (candidate_pd.Count == best_pd.Count) {
4813 if (candidate_params)
4816 if (!candidate_pd.FixedParameters [j - 1].HasDefaultValue && best_pd.FixedParameters [j - 1].HasDefaultValue)
4819 if (candidate_pd.FixedParameters [j - 1].HasDefaultValue && best_pd.HasParams)
4827 // If candidate is applicable in its normal form and best has a params array and is applicable
4828 // only in its expanded form, then candidate is better
4830 if (candidate_params != best_params)
4831 return !candidate_params;
4834 // We have not reached end of parameters list due to params or used default parameters
4836 bool defaults_ambiguity = false;
4837 while (j < candidate_pd.Count && j < best_pd.Count) {
4838 var cand_param = candidate_pd.FixedParameters [j];
4839 var best_param = best_pd.FixedParameters [j];
4841 if (cand_param.HasDefaultValue != best_param.HasDefaultValue && (!candidate_pd.HasParams || !best_pd.HasParams))
4842 return cand_param.HasDefaultValue;
4844 defaults_ambiguity = true;
4845 if (candidate_pd.Count == best_pd.Count) {
4849 // void Foo (int i = 0) is better than void Foo (params int[]) for Foo ()
4850 // void Foo (string[] s, string value = null) is better than Foo (string s, params string[]) for Foo (null) or Foo ()
4852 if (cand_param.HasDefaultValue) {
4861 // Neither is better when not all arguments are provided
4863 // void Foo (string s, int i = 0) <-> Foo (string s, int i = 0, int i2 = 0)
4864 // void Foo (string s, int i = 0) <-> Foo (string s, byte i = 0)
4865 // void Foo (string s, params int[]) <-> Foo (string s, params byte[])
4870 if (candidate_pd.Count != best_pd.Count) {
4871 if (defaults_ambiguity && best_pd.Count - 1 == j)
4872 return best_pd.HasParams;
4874 return candidate_pd.Count < best_pd.Count;
4878 // One is a non-generic method and second is a generic method, then non-generic is better
4880 if (best.IsGeneric != candidate.IsGeneric)
4881 return best.IsGeneric;
4884 // Both methods have the same number of parameters, and the parameters have equal types
4885 // Pick the "more specific" signature using rules over original (non-inflated) types
4887 var candidate_def_pd = ((IParametersMember) candidate.MemberDefinition).Parameters;
4888 var best_def_pd = ((IParametersMember) best.MemberDefinition).Parameters;
4890 bool specific_at_least_once = false;
4891 for (j = 0; j < args_count; ++j) {
4892 NamedArgument na = args_count == 0 ? null : args [j] as NamedArgument;
4894 ct = candidate_def_pd.Types[cparam.GetParameterIndexByName (na.Name)];
4895 bt = best_def_pd.Types[bparam.GetParameterIndexByName (na.Name)];
4897 ct = candidate_def_pd.Types[j];
4898 bt = best_def_pd.Types[j];
4903 TypeSpec specific = MoreSpecific (ct, bt);
4907 specific_at_least_once = true;
4910 if (specific_at_least_once)
4916 static bool CheckInflatedArguments (MethodSpec ms)
4918 if (!TypeParameterSpec.HasAnyTypeParameterTypeConstrained (ms.GenericDefinition))
4921 // Setup constraint checker for probing only
4922 ConstraintChecker cc = new ConstraintChecker (null);
4924 var mp = ms.Parameters.Types;
4925 for (int i = 0; i < mp.Length; ++i) {
4926 var type = mp[i] as InflatedTypeSpec;
4930 var targs = type.TypeArguments;
4931 if (targs.Length == 0)
4934 // TODO: Checking inflated MVAR arguments should be enough
4935 if (!cc.CheckAll (type.GetDefinition (), targs, type.Constraints, Location.Null))
4942 public static void Error_ConstructorMismatch (ResolveContext rc, TypeSpec type, int argCount, Location loc)
4944 rc.Report.Error (1729, loc,
4945 "The type `{0}' does not contain a constructor that takes `{1}' arguments",
4946 type.GetSignatureForError (), argCount.ToString ());
4950 // Determines if the candidate method is applicable to the given set of arguments
4951 // There could be two different set of parameters for same candidate where one
4952 // is the closest override for default values and named arguments checks and second
4953 // one being the virtual base for the parameter types and modifiers.
4955 // A return value rates candidate method compatibility,
4957 // 0 = the best, int.MaxValue = the worst
4959 int IsApplicable (ResolveContext ec, ref Arguments arguments, int arg_count, ref MemberSpec candidate, IParametersMember pm, ref bool params_expanded_form, ref bool dynamicArgument, ref TypeSpec returnType, bool errorMode)
4962 // Each step has allocated 10 values, it can overflow for
4963 // more than 10 arguments but that's ok as it's used for
4964 // better error reporting only
4966 const int ArgumentCountMismatch = 1000000000;
4967 const int NamedArgumentsMismatch = 100000000;
4968 const int DefaultArgumentMismatch = 10000000;
4969 const int UnexpectedTypeArguments = 1000000;
4970 const int TypeArgumentsMismatch = 100000;
4971 const int InflatedTypesMismatch = 10000;
4973 // Parameters of most-derived type used mainly for named and optional parameters
4974 var pd = pm.Parameters;
4976 // Used for params modifier only, that's legacy of C# 1.0 which uses base type for
4977 // params modifier instead of most-derived type
4978 var cpd = ((IParametersMember) candidate).Parameters;
4979 int param_count = pd.Count;
4980 int optional_count = 0;
4982 Arguments orig_args = arguments;
4984 if (arg_count != param_count) {
4986 // No arguments expansion when doing exact match for delegates
4988 if ((restrictions & Restrictions.CovariantDelegate) == 0) {
4989 for (int i = 0; i < pd.Count; ++i) {
4990 if (pd.FixedParameters[i].HasDefaultValue) {
4991 optional_count = pd.Count - i;
4997 if (optional_count != 0) {
4998 // Readjust expected number when params used
4999 if (cpd.HasParams) {
5001 if (arg_count < param_count)
5003 } else if (arg_count > param_count) {
5004 int args_gap = System.Math.Abs (arg_count - param_count);
5005 return ArgumentCountMismatch + args_gap;
5006 } else if (arg_count < param_count - optional_count) {
5007 int args_gap = System.Math.Abs (param_count - optional_count - arg_count);
5008 return ArgumentCountMismatch + args_gap;
5010 } else if (arg_count != param_count) {
5011 int args_gap = System.Math.Abs (arg_count - param_count);
5013 return ArgumentCountMismatch + args_gap;
5014 if (arg_count < param_count - 1)
5015 return ArgumentCountMismatch + args_gap;
5018 // Resize to fit optional arguments
5019 if (optional_count != 0) {
5020 if (arguments == null) {
5021 arguments = new Arguments (optional_count);
5023 // Have to create a new container, so the next run can do same
5024 var resized = new Arguments (param_count);
5025 resized.AddRange (arguments);
5026 arguments = resized;
5029 for (int i = arg_count; i < param_count; ++i)
5030 arguments.Add (null);
5034 if (arg_count > 0) {
5036 // Shuffle named arguments to the right positions if there are any
5038 if (arguments[arg_count - 1] is NamedArgument) {
5039 arg_count = arguments.Count;
5041 for (int i = 0; i < arg_count; ++i) {
5042 bool arg_moved = false;
5044 NamedArgument na = arguments[i] as NamedArgument;
5048 int index = pd.GetParameterIndexByName (na.Name);
5050 // Named parameter not found
5052 return NamedArgumentsMismatch - i;
5054 // already reordered
5059 if (index >= param_count) {
5060 // When using parameters which should not be available to the user
5061 if ((cpd.FixedParameters[index].ModFlags & Parameter.Modifier.PARAMS) == 0)
5064 arguments.Add (null);
5068 if (index == arg_count)
5069 return NamedArgumentsMismatch - i - 1;
5071 temp = arguments [index];
5073 // The slot has been taken by positional argument
5074 if (temp != null && !(temp is NamedArgument))
5075 return NamedArgumentsMismatch - i - 1;
5079 arguments = arguments.MarkOrderedArgument (na);
5083 if (arguments == orig_args) {
5084 arguments = new Arguments (orig_args.Count);
5085 arguments.AddRange (orig_args);
5088 arguments[index] = arguments[i];
5089 arguments[i] = temp;
5096 arg_count = arguments.Count;
5098 } else if (arguments != null) {
5099 arg_count = arguments.Count;
5103 // Don't do any expensive checks when the candidate cannot succeed
5105 if (arg_count != param_count && !cpd.HasParams)
5106 return DefaultArgumentMismatch - System.Math.Abs (param_count - arg_count);
5108 var dep = candidate.GetMissingDependencies ();
5110 ImportedTypeDefinition.Error_MissingDependency (ec, dep, loc);
5115 // 1. Handle generic method using type arguments when specified or type inference
5118 var ms = candidate as MethodSpec;
5119 if (ms != null && ms.IsGeneric) {
5120 if (type_arguments != null) {
5121 var g_args_count = ms.Arity;
5122 if (g_args_count != type_arguments.Count)
5123 return TypeArgumentsMismatch - System.Math.Abs (type_arguments.Count - g_args_count);
5125 if (type_arguments.Arguments != null)
5126 ms = ms.MakeGenericMethod (ec, type_arguments.Arguments);
5129 // Deploy custom error reporting for infered anonymous expression or lambda methods. When
5130 // probing lambda methods keep all errors reported in separate set and once we are done and no best
5131 // candidate was found use the set to report more details about what was wrong with lambda body.
5132 // The general idea is to distinguish between code errors and errors caused by
5133 // trial-and-error type inference
5135 if (lambda_conv_msgs == null) {
5136 for (int i = 0; i < arg_count; i++) {
5137 Argument a = arguments[i];
5141 var am = a.Expr as AnonymousMethodExpression;
5143 if (lambda_conv_msgs == null)
5144 lambda_conv_msgs = new SessionReportPrinter ();
5146 am.TypeInferenceReportPrinter = lambda_conv_msgs;
5151 var ti = new TypeInference (arguments);
5152 TypeSpec[] i_args = ti.InferMethodArguments (ec, ms);
5155 return TypeArgumentsMismatch - ti.InferenceScore;
5158 // Clear any error messages when the result was success
5160 if (lambda_conv_msgs != null)
5161 lambda_conv_msgs.ClearSession ();
5163 if (i_args.Length != 0) {
5165 for (int i = 0; i < i_args.Length; ++i) {
5166 var ta = i_args [i];
5167 if (!ta.IsAccessible (ec))
5168 return TypeArgumentsMismatch - i;
5172 ms = ms.MakeGenericMethod (ec, i_args);
5177 // Type arguments constraints have to match for the method to be applicable
5179 if (!CheckInflatedArguments (ms)) {
5181 return InflatedTypesMismatch;
5185 // We have a generic return type and at same time the method is override which
5186 // means we have to also inflate override return type in case the candidate is
5187 // best candidate and override return type is different to base return type.
5189 // virtual Foo<T, object> with override Foo<T, dynamic>
5191 if (candidate != pm) {
5192 MethodSpec override_ms = (MethodSpec) pm;
5193 var inflator = new TypeParameterInflator (ec, ms.DeclaringType, override_ms.GenericDefinition.TypeParameters, ms.TypeArguments);
5194 returnType = inflator.Inflate (returnType);
5196 returnType = ms.ReturnType;
5203 if (type_arguments != null)
5204 return UnexpectedTypeArguments;
5210 // 2. Each argument has to be implicitly convertible to method parameter
5212 Parameter.Modifier p_mod = 0;
5215 for (int i = 0; i < arg_count; i++) {
5216 Argument a = arguments[i];
5218 var fp = pd.FixedParameters[i];
5219 if (!fp.HasDefaultValue) {
5220 arguments = orig_args;
5221 return arg_count * 2 + 2;
5225 // Get the default value expression, we can use the same expression
5226 // if the type matches
5228 Expression e = fp.DefaultValue;
5230 e = ResolveDefaultValueArgument (ec, ptypes[i], e, loc);
5232 // Restore for possible error reporting
5233 for (int ii = i; ii < arg_count; ++ii)
5234 arguments.RemoveAt (i);
5236 return (arg_count - i) * 2 + 1;
5240 if ((fp.ModFlags & Parameter.Modifier.CallerMask) != 0) {
5242 // LAMESPEC: Attributes can be mixed together with build-in priority
5244 if ((fp.ModFlags & Parameter.Modifier.CallerLineNumber) != 0) {
5245 e = new IntLiteral (ec.BuiltinTypes, loc.Row, loc);
5246 } else if ((fp.ModFlags & Parameter.Modifier.CallerFilePath) != 0) {
5247 e = new StringLiteral (ec.BuiltinTypes, loc.SourceFile.GetFullPathName (ec.Module.Compiler.Settings.PathMap), loc);
5248 } else if (ec.MemberContext.CurrentMemberDefinition != null) {
5249 e = new StringLiteral (ec.BuiltinTypes, ec.MemberContext.CurrentMemberDefinition.GetCallerMemberName (), loc);
5253 arguments[i] = new Argument (e, Argument.AType.Default);
5257 if (p_mod != Parameter.Modifier.PARAMS) {
5258 p_mod = (pd.FixedParameters[i].ModFlags & ~Parameter.Modifier.PARAMS) | (cpd.FixedParameters[i].ModFlags & Parameter.Modifier.PARAMS);
5260 } else if (!params_expanded_form) {
5261 params_expanded_form = true;
5262 pt = ((ElementTypeSpec) pt).Element;
5268 if (!params_expanded_form) {
5269 if (a.IsExtensionType) {
5270 if (ExtensionMethodGroupExpr.IsExtensionTypeCompatible (a.Type, pt)) {
5275 score = IsArgumentCompatible (ec, a, p_mod, pt);
5278 dynamicArgument = true;
5283 // It can be applicable in expanded form (when not doing exact match like for delegates)
5285 if (score != 0 && (p_mod & Parameter.Modifier.PARAMS) != 0 && (restrictions & Restrictions.CovariantDelegate) == 0) {
5286 if (!params_expanded_form) {
5287 pt = ((ElementTypeSpec) pt).Element;
5291 score = IsArgumentCompatible (ec, a, Parameter.Modifier.NONE, pt);
5294 params_expanded_form = true;
5295 dynamicArgument = true;
5296 } else if (score == 0 || arg_count > pd.Count) {
5297 params_expanded_form = true;
5302 if (params_expanded_form)
5304 return (arg_count - i) * 2 + score;
5309 // Restore original arguments for dynamic binder to keep the intention of original source code
5311 if (dynamicArgument)
5312 arguments = orig_args;
5317 public static Expression ResolveDefaultValueArgument (ResolveContext ec, TypeSpec ptype, Expression e, Location loc)
5319 if (e is Constant && e.Type == ptype)
5323 // LAMESPEC: No idea what the exact rules are for System.Reflection.Missing.Value instead of null
5325 if (e == EmptyExpression.MissingValue && (ptype.BuiltinType == BuiltinTypeSpec.Type.Object || ptype.BuiltinType == BuiltinTypeSpec.Type.Dynamic)) {
5326 e = new MemberAccess (new MemberAccess (new MemberAccess (
5327 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Reflection", loc), "Missing", loc), "Value", loc);
5328 } else if (e is Constant) {
5330 // Handles int to int? conversions, DefaultParameterValue check
5332 e = Convert.ImplicitConversionStandard (ec, e, ptype, loc);
5336 e = new DefaultValueExpression (new TypeExpression (ptype, loc), loc);
5339 return e.Resolve (ec);
5343 // Tests argument compatibility with the parameter
5344 // The possible return values are
5346 // 1 - modifier mismatch
5347 // 2 - type mismatch
5348 // -1 - dynamic binding required
5350 int IsArgumentCompatible (ResolveContext ec, Argument argument, Parameter.Modifier param_mod, TypeSpec parameter)
5353 // Types have to be identical when ref or out modifer
5354 // is used and argument is not of dynamic type
5356 if (((argument.Modifier | param_mod) & Parameter.Modifier.RefOutMask) != 0) {
5357 var arg_type = argument.Type;
5359 if ((argument.Modifier & Parameter.Modifier.RefOutMask) != (param_mod & Parameter.Modifier.RefOutMask)) {
5361 // Using dynamic for ref/out parameter can still succeed at runtime
5363 if (arg_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic && (argument.Modifier & Parameter.Modifier.RefOutMask) == 0 && (restrictions & Restrictions.CovariantDelegate) == 0)
5369 if (arg_type != parameter) {
5370 if (arg_type == InternalType.VarOutType)
5374 // Do full equality check after quick path
5376 if (!TypeSpecComparer.IsEqual (arg_type, parameter)) {
5378 // Using dynamic for ref/out parameter can still succeed at runtime
5380 if (arg_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic && (argument.Modifier & Parameter.Modifier.RefOutMask) == 0 && (restrictions & Restrictions.CovariantDelegate) == 0)
5388 if (argument.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic && (restrictions & Restrictions.CovariantDelegate) == 0)
5392 // Use implicit conversion in all modes to return same candidates when the expression
5393 // is used as argument or delegate conversion
5395 if (!Convert.ImplicitConversionExists (ec, argument.Expr, parameter)) {
5396 return parameter.IsDelegate && argument.Expr is AnonymousMethodExpression ? 2 : 3;
5403 static TypeSpec MoreSpecific (TypeSpec p, TypeSpec q)
5405 if (p.IsGenericParameter != q.IsGenericParameter)
5406 return p.IsGenericParameter ? q : p;
5408 var ac_p = p as ArrayContainer;
5410 var ac_q = q as ArrayContainer;
5414 TypeSpec specific = MoreSpecific (ac_p.Element, ac_q.Element);
5415 if (specific == ac_p.Element)
5417 if (specific == ac_q.Element)
5423 if (p.IsGeneric && q.IsGeneric) {
5424 var pargs = p.TypeArguments;
5425 var qargs = q.TypeArguments;
5427 bool p_specific_at_least_once = false;
5428 bool q_specific_at_least_once = false;
5430 for (int i = 0; i < pargs.Length; i++) {
5431 TypeSpec specific = MoreSpecific (pargs [i], qargs [i]);
5432 if (specific == pargs [i])
5433 p_specific_at_least_once = true;
5434 if (specific == qargs [i])
5435 q_specific_at_least_once = true;
5438 if (p_specific_at_least_once && !q_specific_at_least_once)
5440 if (!p_specific_at_least_once && q_specific_at_least_once)
5448 // Find the best method from candidate list
5450 public T ResolveMember<T> (ResolveContext rc, ref Arguments args) where T : MemberSpec, IParametersMember
5452 List<AmbiguousCandidate> ambiguous_candidates = null;
5454 MemberSpec best_candidate;
5455 Arguments best_candidate_args = null;
5456 bool best_candidate_params = false;
5457 bool best_candidate_dynamic = false;
5458 int best_candidate_rate;
5459 IParametersMember best_parameter_member = null;
5461 int args_count = args != null ? args.Count : 0;
5463 Arguments candidate_args = args;
5464 bool error_mode = false;
5465 MemberSpec invocable_member = null;
5466 int applicable_candidates = 0;
5469 best_candidate = null;
5470 best_candidate_rate = int.MaxValue;
5472 var type_members = members;
5474 for (int i = 0; i < type_members.Count; ++i) {
5475 var member = type_members[i];
5478 // Methods in a base class are not candidates if any method in a derived
5479 // class is applicable
5481 if ((member.Modifiers & Modifiers.OVERRIDE) != 0)
5485 if (!member.IsAccessible (rc))
5488 if (rc.IsRuntimeBinder && !member.DeclaringType.IsAccessible (rc))
5491 if ((member.Modifiers & (Modifiers.PROTECTED | Modifiers.STATIC)) == Modifiers.PROTECTED &&
5492 instance_qualifier != null && !instance_qualifier.CheckProtectedMemberAccess (rc, member)) {
5497 IParametersMember pm = member as IParametersMember;
5500 // Will use it later to report ambiguity between best method and invocable member
5502 if (Invocation.IsMemberInvocable (member))
5503 invocable_member = member;
5509 // Overload resolution is looking for base member but using parameter names
5510 // and default values from the closest member. That means to do expensive lookup
5511 // for the closest override for virtual or abstract members
5513 if ((member.Modifiers & (Modifiers.VIRTUAL | Modifiers.ABSTRACT)) != 0) {
5514 var override_params = base_provider.GetOverrideMemberParameters (member);
5515 if (override_params != null)
5516 pm = override_params;
5520 // Check if the member candidate is applicable
5522 bool params_expanded_form = false;
5523 bool dynamic_argument = false;
5524 TypeSpec rt = pm.MemberType;
5525 int candidate_rate = IsApplicable (rc, ref candidate_args, args_count, ref member, pm, ref params_expanded_form, ref dynamic_argument, ref rt, error_mode);
5527 if (lambda_conv_msgs != null)
5528 lambda_conv_msgs.EndSession ();
5531 // How does it score compare to others
5533 if (candidate_rate < best_candidate_rate) {
5535 // Fatal error (missing dependency), cannot continue
5536 if (candidate_rate < 0)
5539 applicable_candidates = 1;
5540 if ((restrictions & Restrictions.GetEnumeratorLookup) != 0 && candidate_args.Count != 0) {
5541 // Only parameterless methods are considered
5543 best_candidate_rate = candidate_rate;
5544 best_candidate = member;
5545 best_candidate_args = candidate_args;
5546 best_candidate_params = params_expanded_form;
5547 best_candidate_dynamic = dynamic_argument;
5548 best_parameter_member = pm;
5549 best_candidate_return_type = rt;
5551 } else if (candidate_rate == 0) {
5553 // The member look is done per type for most operations but sometimes
5554 // it's not possible like for binary operators overload because they
5555 // are unioned between 2 sides
5557 if ((restrictions & Restrictions.BaseMembersIncluded) != 0) {
5558 if (TypeSpec.IsBaseClass (best_candidate.DeclaringType, member.DeclaringType, true))
5562 ++applicable_candidates;
5564 if (best_candidate.DeclaringType.IsInterface && member.DeclaringType.ImplementsInterface (best_candidate.DeclaringType, false)) {
5566 // We pack all interface members into top level type which makes the overload resolution
5567 // more complicated for interfaces. We compensate it by removing methods with same
5568 // signature when building the cache hence this path should not really be hit often
5571 // interface IA { void Foo (int arg); }
5572 // interface IB : IA { void Foo (params int[] args); }
5574 // IB::Foo is the best overload when calling IB.Foo (1)
5577 if (ambiguous_candidates != null) {
5578 foreach (var amb_cand in ambiguous_candidates) {
5579 if (member.DeclaringType.ImplementsInterface (best_candidate.DeclaringType, false)) {
5588 ambiguous_candidates = null;
5591 // Is the new candidate better
5592 is_better = BetterFunction (rc, candidate_args, member, pm.Parameters, params_expanded_form, best_candidate, best_parameter_member.Parameters, best_candidate_params);
5596 best_candidate = member;
5597 best_candidate_args = candidate_args;
5598 best_candidate_params = params_expanded_form;
5599 best_candidate_dynamic = dynamic_argument;
5600 best_parameter_member = pm;
5601 best_candidate_return_type = rt;
5603 // It's not better but any other found later could be but we are not sure yet
5604 if (ambiguous_candidates == null)
5605 ambiguous_candidates = new List<AmbiguousCandidate> ();
5607 ambiguous_candidates.Add (new AmbiguousCandidate (member, pm.Parameters, params_expanded_form));
5611 // Restore expanded arguments
5612 candidate_args = args;
5614 } while (best_candidate_rate != 0 && (type_members = base_provider.GetBaseMembers (type_members[0].DeclaringType)) != null);
5617 // We've found exact match
5619 if (best_candidate_rate == 0)
5623 // Try extension methods lookup when no ordinary method match was found and provider enables it
5626 var emg = base_provider.LookupExtensionMethod (rc);
5628 emg = emg.OverloadResolve (rc, ref args, null, restrictions);
5630 best_candidate_extension_group = emg;
5631 return (T) (MemberSpec) emg.BestCandidate;
5636 // Don't run expensive error reporting mode for probing
5643 if (lambda_conv_msgs != null && !lambda_conv_msgs.IsEmpty)
5646 lambda_conv_msgs = null;
5651 // No best member match found, report an error
5653 if (best_candidate_rate != 0 || error_mode) {
5654 ReportOverloadError (rc, best_candidate, best_parameter_member, best_candidate_args, best_candidate_params);
5658 if (best_candidate_dynamic) {
5659 if (args[0].IsExtensionType) {
5660 rc.Report.Error (1973, loc,
5661 "Type `{0}' does not contain a member `{1}' and the best extension method overload `{2}' cannot be dynamically dispatched. Consider calling the method without the extension method syntax",
5662 args [0].Type.GetSignatureForError (), best_candidate.Name, best_candidate.GetSignatureForError ());
5666 // Check type constraints only when explicit type arguments are used
5668 if (applicable_candidates == 1 && best_candidate.IsGeneric && type_arguments != null) {
5669 MethodSpec bc = best_candidate as MethodSpec;
5670 if (bc != null && TypeParameterSpec.HasAnyTypeParameterConstrained (bc.GenericDefinition)) {
5671 ConstraintChecker cc = new ConstraintChecker (rc);
5672 cc.CheckAll (bc.GetGenericMethodDefinition (), bc.TypeArguments, bc.Constraints, loc);
5676 BestCandidateIsDynamic = true;
5681 // These flags indicates we are running delegate probing conversion. No need to
5682 // do more expensive checks
5684 if ((restrictions & (Restrictions.ProbingOnly | Restrictions.CovariantDelegate)) == (Restrictions.CovariantDelegate | Restrictions.ProbingOnly))
5685 return (T) best_candidate;
5687 if (ambiguous_candidates != null) {
5689 // Now check that there are no ambiguities i.e the selected method
5690 // should be better than all the others
5692 for (int ix = 0; ix < ambiguous_candidates.Count; ix++) {
5693 var candidate = ambiguous_candidates [ix];
5695 if (!BetterFunction (rc, best_candidate_args, best_candidate, best_parameter_member.Parameters, best_candidate_params, candidate.Member, candidate.Parameters, candidate.Expanded)) {
5696 var ambiguous = candidate.Member;
5697 if (custom_errors == null || !custom_errors.AmbiguousCandidates (rc, best_candidate, ambiguous)) {
5698 rc.Report.SymbolRelatedToPreviousError (best_candidate);
5699 rc.Report.SymbolRelatedToPreviousError (ambiguous);
5700 rc.Report.Error (121, loc, "The call is ambiguous between the following methods or properties: `{0}' and `{1}'",
5701 best_candidate.GetSignatureForError (), ambiguous.GetSignatureForError ());
5704 return (T) best_candidate;
5709 if (invocable_member != null && !IsProbingOnly) {
5710 rc.Report.SymbolRelatedToPreviousError (best_candidate);
5711 rc.Report.SymbolRelatedToPreviousError (invocable_member);
5712 rc.Report.Warning (467, 2, loc, "Ambiguity between method `{0}' and invocable non-method `{1}'. Using method group",
5713 best_candidate.GetSignatureForError (), invocable_member.GetSignatureForError ());
5717 // And now check if the arguments are all
5718 // compatible, perform conversions if
5719 // necessary etc. and return if everything is
5722 if (!VerifyArguments (rc, ref best_candidate_args, best_candidate, best_parameter_member, best_candidate_params))
5725 if (best_candidate == null)
5729 // Don't run possibly expensive checks in probing mode
5731 if (!IsProbingOnly && !rc.IsInProbingMode) {
5733 // Check ObsoleteAttribute on the best method
5735 best_candidate.CheckObsoleteness (rc, loc);
5737 best_candidate.MemberDefinition.SetIsUsed ();
5740 args = best_candidate_args;
5741 return (T) best_candidate;
5744 public MethodSpec ResolveOperator (ResolveContext rc, ref Arguments args)
5746 return ResolveMember<MethodSpec> (rc, ref args);
5749 void ReportArgumentMismatch (ResolveContext ec, int idx, MemberSpec method,
5750 Argument a, AParametersCollection expected_par, TypeSpec paramType)
5752 if (custom_errors != null && custom_errors.ArgumentMismatch (ec, method, a, idx))
5755 if (a.Type == InternalType.ErrorType)
5758 if (a is CollectionElementInitializer.ElementInitializerArgument) {
5759 ec.Report.SymbolRelatedToPreviousError (method);
5760 if ((expected_par.FixedParameters[idx].ModFlags & Parameter.Modifier.RefOutMask) != 0) {
5761 ec.Report.Error (1954, loc, "The best overloaded collection initalizer method `{0}' cannot have `ref' or `out' modifier",
5762 TypeManager.CSharpSignature (method));
5765 ec.Report.Error (1950, loc, "The best overloaded collection initalizer method `{0}' has some invalid arguments",
5766 TypeManager.CSharpSignature (method));
5767 } else if (IsDelegateInvoke) {
5768 ec.Report.Error (1594, loc, "Delegate `{0}' has some invalid arguments",
5769 DelegateType.GetSignatureForError ());
5771 ec.Report.SymbolRelatedToPreviousError (method);
5772 ec.Report.Error (1502, loc, "The best overloaded method match for `{0}' has some invalid arguments",
5773 method.GetSignatureForError ());
5776 Parameter.Modifier mod = idx >= expected_par.Count ? 0 : expected_par.FixedParameters[idx].ModFlags;
5778 string index = (idx + 1).ToString ();
5779 if (((mod & Parameter.Modifier.RefOutMask) ^ (a.Modifier & Parameter.Modifier.RefOutMask)) != 0) {
5780 if ((mod & Parameter.Modifier.RefOutMask) == 0)
5781 ec.Report.Error (1615, a.Expr.Location, "Argument `#{0}' does not require `{1}' modifier. Consider removing `{1}' modifier",
5782 index, Parameter.GetModifierSignature (a.Modifier));
5784 ec.Report.Error (1620, a.Expr.Location, "Argument `#{0}' is missing `{1}' modifier",
5785 index, Parameter.GetModifierSignature (mod));
5787 string p1 = a.GetSignatureForError ();
5788 string p2 = paramType.GetSignatureForError ();
5791 p1 = a.Type.GetSignatureForErrorIncludingAssemblyName ();
5792 p2 = paramType.GetSignatureForErrorIncludingAssemblyName ();
5795 if ((mod & Parameter.Modifier.RefOutMask) != 0) {
5796 p1 = Parameter.GetModifierSignature (a.Modifier) + " " + p1;
5797 p2 = Parameter.GetModifierSignature (a.Modifier) + " " + p2;
5800 ec.Report.Error (1503, a.Expr.Location,
5801 "Argument `#{0}' cannot convert `{1}' expression to type `{2}'", index, p1, p2);
5806 // We have failed to find exact match so we return error info about the closest match
5808 void ReportOverloadError (ResolveContext rc, MemberSpec best_candidate, IParametersMember pm, Arguments args, bool params_expanded)
5810 int ta_count = type_arguments == null ? 0 : type_arguments.Count;
5811 int arg_count = args == null ? 0 : args.Count;
5813 if (ta_count != best_candidate.Arity && (ta_count > 0 || ((IParametersMember) best_candidate).Parameters.IsEmpty)) {
5814 var mg = new MethodGroupExpr (new [] { best_candidate }, best_candidate.DeclaringType, loc);
5815 mg.Error_TypeArgumentsCannotBeUsed (rc, best_candidate, loc);
5819 if (lambda_conv_msgs != null && lambda_conv_msgs.Merge (rc.Report.Printer)) {
5824 if ((best_candidate.Modifiers & (Modifiers.PROTECTED | Modifiers.STATIC)) == Modifiers.PROTECTED &&
5825 InstanceQualifier != null && !InstanceQualifier.CheckProtectedMemberAccess (rc, best_candidate)) {
5826 MemberExpr.Error_ProtectedMemberAccess (rc, best_candidate, InstanceQualifier.InstanceType, loc);
5830 // For candidates which match on parameters count report more details about incorrect arguments
5833 if (pm.Parameters.Count == arg_count || params_expanded || HasUnfilledParams (best_candidate, pm, args)) {
5834 // Reject any inaccessible member
5835 if (!best_candidate.IsAccessible (rc) || !best_candidate.DeclaringType.IsAccessible (rc)) {
5836 rc.Report.SymbolRelatedToPreviousError (best_candidate);
5837 Expression.ErrorIsInaccesible (rc, best_candidate.GetSignatureForError (), loc);
5841 var ms = best_candidate as MethodSpec;
5842 if (ms != null && ms.IsGeneric) {
5843 bool constr_ok = true;
5844 if (ms.TypeArguments != null)
5845 constr_ok = new ConstraintChecker (rc.MemberContext).CheckAll (ms.GetGenericMethodDefinition (), ms.TypeArguments, ms.Constraints, loc);
5847 if (ta_count == 0 && ms.TypeArguments == null) {
5848 if (custom_errors != null && custom_errors.TypeInferenceFailed (rc, best_candidate))
5852 rc.Report.Error (411, loc,
5853 "The type arguments for method `{0}' cannot be inferred from the usage. Try specifying the type arguments explicitly",
5854 ms.GetGenericMethodDefinition ().GetSignatureForError ());
5861 VerifyArguments (rc, ref args, best_candidate, pm, params_expanded);
5867 // We failed to find any method with correct argument count, report best candidate
5869 if (custom_errors != null && custom_errors.NoArgumentMatch (rc, best_candidate))
5872 if (best_candidate.Kind == MemberKind.Constructor) {
5873 rc.Report.SymbolRelatedToPreviousError (best_candidate);
5874 Error_ConstructorMismatch (rc, best_candidate.DeclaringType, arg_count, loc);
5875 } else if (IsDelegateInvoke) {
5876 rc.Report.SymbolRelatedToPreviousError (DelegateType);
5877 rc.Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
5878 DelegateType.GetSignatureForError (), arg_count.ToString ());
5880 string name = best_candidate.Kind == MemberKind.Indexer ? "this" : best_candidate.Name;
5881 rc.Report.SymbolRelatedToPreviousError (best_candidate);
5882 rc.Report.Error (1501, loc, "No overload for method `{0}' takes `{1}' arguments",
5883 name, arg_count.ToString ());
5887 static bool HasUnfilledParams (MemberSpec best_candidate, IParametersMember pm, Arguments args)
5889 var p = ((IParametersMember)best_candidate).Parameters;
5894 for (int i = p.Count - 1; i != 0; --i) {
5895 var fp = p.FixedParameters [i];
5896 if ((fp.ModFlags & Parameter.Modifier.PARAMS) == 0)
5906 foreach (var arg in args) {
5907 var na = arg as NamedArgument;
5911 if (na.Name == name) {
5920 return args.Count + 1 == pm.Parameters.Count;
5923 bool VerifyArguments (ResolveContext ec, ref Arguments args, MemberSpec member, IParametersMember pm, bool chose_params_expanded)
5925 var pd = pm.Parameters;
5926 var cpd = ((IParametersMember) member).Parameters;
5927 var ptypes = cpd.Types;
5929 Parameter.Modifier p_mod = 0;
5931 int a_idx = 0, a_pos = 0;
5933 ArrayInitializer params_initializers = null;
5934 bool has_unsafe_arg = pm.MemberType.IsPointer;
5935 int arg_count = args == null ? 0 : args.Count;
5937 for (; a_idx < arg_count; a_idx++, ++a_pos) {
5942 if (p_mod != Parameter.Modifier.PARAMS) {
5943 p_mod = cpd.FixedParameters [a_idx].ModFlags;
5945 has_unsafe_arg |= pt.IsPointer;
5947 if (p_mod == Parameter.Modifier.PARAMS) {
5948 if (chose_params_expanded) {
5949 params_initializers = new ArrayInitializer (arg_count - a_idx, a.Expr.Location);
5950 pt = TypeManager.GetElementType (pt);
5956 // Types have to be identical when ref or out modifer is used
5958 if (((a.Modifier | p_mod) & Parameter.Modifier.RefOutMask) != 0) {
5959 if ((a.Modifier & Parameter.Modifier.RefOutMask) != (p_mod & Parameter.Modifier.RefOutMask))
5962 var arg_type = a.Type;
5966 if (arg_type == InternalType.VarOutType) {
5968 // Set underlying variable type based on parameter type
5970 ((DeclarationExpression)a.Expr).Variable.Type = pt;
5974 if (!TypeSpecComparer.IsEqual (arg_type, pt))
5978 NamedArgument na = a as NamedArgument;
5980 int name_index = pd.GetParameterIndexByName (na.Name);
5981 if (name_index < 0 || name_index >= pd.Count) {
5982 if (IsDelegateInvoke) {
5983 ec.Report.SymbolRelatedToPreviousError (DelegateType);
5984 ec.Report.Error (1746, na.Location,
5985 "The delegate `{0}' does not contain a parameter named `{1}'",
5986 DelegateType.GetSignatureForError (), na.Name);
5988 ec.Report.SymbolRelatedToPreviousError (member);
5989 ec.Report.Error (1739, na.Location,
5990 "The best overloaded method match for `{0}' does not contain a parameter named `{1}'",
5991 TypeManager.CSharpSignature (member), na.Name);
5993 } else if (args[name_index] != a && args[name_index] != null) {
5994 if (IsDelegateInvoke)
5995 ec.Report.SymbolRelatedToPreviousError (DelegateType);
5997 ec.Report.SymbolRelatedToPreviousError (member);
5999 ec.Report.Error (1744, na.Location,
6000 "Named argument `{0}' cannot be used for a parameter which has positional argument specified",
6005 if (a.Expr.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
6008 if ((restrictions & Restrictions.CovariantDelegate) != 0 && !Delegate.IsTypeCovariant (ec, a.Expr.Type, pt)) {
6009 if (a.IsExtensionType) {
6010 // TODO: Should report better message type, something similar to CS1928/1929 instead of
6011 // CS1061 but that still better than confusing CS0123
6012 var ma = new MemberAccess (a.Expr, member.Name, loc);
6013 ma.Error_TypeDoesNotContainDefinition (ec, a.Expr.Type, ma.Name);
6015 custom_errors.NoArgumentMatch (ec, member);
6021 if (a.IsExtensionType) {
6022 if (a.Expr.Type == pt || TypeSpecComparer.IsEqual (a.Expr.Type, pt)) {
6025 conv = Convert.ImplicitReferenceConversion (a.Expr, pt, false);
6027 conv = Convert.ImplicitBoxingConversion (a.Expr, a.Expr.Type, pt);
6030 conv = Convert.ImplicitConversion (ec, a.Expr, pt, loc);
6037 // Convert params arguments to an array initializer
6039 if (params_initializers != null) {
6040 // we choose to use 'a.Expr' rather than 'conv' so that
6041 // we don't hide the kind of expression we have (esp. CompoundAssign.Helper)
6042 params_initializers.Add (a.Expr);
6043 args.RemoveAt (a_idx--);
6049 // Update the argument with the implicit conversion
6053 if (a_idx != arg_count) {
6055 // Convert all var out argument to error type for less confusing error reporting
6056 // when no matching overload is found
6058 for (; a_idx < arg_count; a_idx++) {
6059 var arg = args [a_idx];
6063 if (arg.Type == InternalType.VarOutType) {
6064 ((DeclarationExpression)arg.Expr).Variable.Type = InternalType.ErrorType;
6068 ReportArgumentMismatch (ec, a_pos, member, a, pd, pt);
6073 // Fill not provided arguments required by params modifier
6075 if (params_initializers == null && arg_count + 1 == pd.Count) {
6077 args = new Arguments (1);
6079 pt = ptypes[pd.Count - 1];
6080 pt = TypeManager.GetElementType (pt);
6081 has_unsafe_arg |= pt.IsPointer;
6082 params_initializers = new ArrayInitializer (0, loc);
6086 // Append an array argument with all params arguments
6088 if (params_initializers != null) {
6089 args.Add (new Argument (
6090 new ArrayCreation (new TypeExpression (pt, loc), params_initializers, loc).Resolve (ec)));
6094 if (has_unsafe_arg) {
6095 if (ec.CurrentIterator != null) {
6096 Expression.UnsafeInsideIteratorError (ec, loc);
6097 } else if (!ec.IsUnsafe) {
6098 Expression.UnsafeError (ec, loc);
6103 // We could infer inaccesible type arguments
6105 if (type_arguments == null && member.IsGeneric) {
6106 var ms = (MethodSpec) member;
6107 foreach (var ta in ms.TypeArguments) {
6108 if (!ta.IsAccessible (ec)) {
6109 ec.Report.SymbolRelatedToPreviousError (ta);
6110 Expression.ErrorIsInaccesible (ec, member.GetSignatureForError (), loc);
6120 public class ConstantExpr : MemberExpr
6122 readonly ConstSpec constant;
6124 public ConstantExpr (ConstSpec constant, Location loc)
6126 this.constant = constant;
6130 public override string Name {
6131 get { throw new NotImplementedException (); }
6134 public override string KindName {
6135 get { return "constant"; }
6138 public override bool IsInstance {
6139 get { return !IsStatic; }
6142 public override bool IsStatic {
6143 get { return true; }
6146 protected override TypeSpec DeclaringType {
6147 get { return constant.DeclaringType; }
6150 public override Expression CreateExpressionTree (ResolveContext ec)
6152 throw new NotSupportedException ("ET");
6155 protected override Expression DoResolve (ResolveContext rc)
6157 ResolveInstanceExpression (rc, null);
6158 DoBestMemberChecks (rc, constant);
6160 if (rc.HasSet (ResolveContext.Options.NameOfScope)) {
6161 eclass = ExprClass.Value;
6162 type = constant.MemberType;
6166 var c = constant.GetConstant (rc);
6168 // Creates reference expression to the constant value
6169 return Constant.CreateConstantFromValue (constant.MemberType, c.GetValue (), loc);
6172 public override void Emit (EmitContext ec)
6174 throw new NotSupportedException ();
6177 public override string GetSignatureForError ()
6179 return constant.GetSignatureForError ();
6182 public override void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
6184 constant.CheckObsoleteness (rc, expr.Location);
6187 public override void SetTypeArguments (ResolveContext ec, TypeArguments ta)
6189 Error_TypeArgumentsCannotBeUsed (ec, "constant", GetSignatureForError (), loc);
6194 // Fully resolved expression that references a Field
6196 public class FieldExpr : MemberExpr, IDynamicAssign, IMemoryLocation, IVariableReference
6198 protected FieldSpec spec;
6199 VariableInfo variable_info;
6201 LocalTemporary temp;
6204 protected FieldExpr (Location l)
6209 public FieldExpr (FieldSpec spec, Location loc)
6214 type = spec.MemberType;
6217 public FieldExpr (FieldBase fi, Location l)
6224 public override string Name {
6230 public bool IsHoisted {
6232 IVariableReference hv = InstanceExpression as IVariableReference;
6233 return hv != null && hv.IsHoisted;
6237 public override bool IsInstance {
6239 return !spec.IsStatic;
6243 public override bool IsStatic {
6245 return spec.IsStatic;
6249 public override string KindName {
6250 get { return "field"; }
6253 public FieldSpec Spec {
6259 protected override TypeSpec DeclaringType {
6261 return spec.DeclaringType;
6265 public VariableInfo VariableInfo {
6267 return variable_info;
6273 public override string GetSignatureForError ()
6275 return spec.GetSignatureForError ();
6278 public bool IsMarshalByRefAccess (ResolveContext rc)
6280 // Checks possible ldflda of field access expression
6281 return !spec.IsStatic && TypeSpec.IsValueType (spec.MemberType) && !(InstanceExpression is This) &&
6282 rc.Module.PredefinedTypes.MarshalByRefObject.Define () &&
6283 TypeSpec.IsBaseClass (spec.DeclaringType, rc.Module.PredefinedTypes.MarshalByRefObject.TypeSpec, false);
6286 public void SetHasAddressTaken ()
6288 IVariableReference vr = InstanceExpression as IVariableReference;
6290 vr.SetHasAddressTaken ();
6294 protected override void CloneTo (CloneContext clonectx, Expression target)
6296 var t = (FieldExpr) target;
6298 if (InstanceExpression != null)
6299 t.InstanceExpression = InstanceExpression.Clone (clonectx);
6302 public override Expression CreateExpressionTree (ResolveContext ec)
6304 if (ConditionalAccess) {
6305 Error_NullShortCircuitInsideExpressionTree (ec);
6308 return CreateExpressionTree (ec, true);
6311 public Expression CreateExpressionTree (ResolveContext ec, bool convertInstance)
6314 Expression instance;
6316 if (InstanceExpression == null) {
6317 instance = new NullLiteral (loc);
6318 } else if (convertInstance) {
6319 instance = InstanceExpression.CreateExpressionTree (ec);
6321 args = new Arguments (1);
6322 args.Add (new Argument (InstanceExpression));
6323 instance = CreateExpressionFactoryCall (ec, "Constant", args);
6326 args = Arguments.CreateForExpressionTree (ec, null,
6328 CreateTypeOfExpression ());
6330 return CreateExpressionFactoryCall (ec, "Field", args);
6333 public Expression CreateTypeOfExpression ()
6335 return new TypeOfField (spec, loc);
6338 protected override Expression DoResolve (ResolveContext ec)
6340 spec.MemberDefinition.SetIsUsed ();
6342 return DoResolve (ec, null);
6345 Expression DoResolve (ResolveContext ec, Expression rhs)
6347 bool lvalue_instance = rhs != null && IsInstance && spec.DeclaringType.IsStruct;
6350 ResolveConditionalAccessReceiver (ec);
6352 if (ResolveInstanceExpression (ec, rhs)) {
6353 // Resolve the field's instance expression while flow analysis is turned
6354 // off: when accessing a field "a.b", we must check whether the field
6355 // "a.b" is initialized, not whether the whole struct "a" is initialized.
6357 if (lvalue_instance) {
6358 bool out_access = rhs == EmptyExpression.OutAccess || rhs == EmptyExpression.LValueMemberOutAccess;
6360 Expression right_side =
6361 out_access ? EmptyExpression.LValueMemberOutAccess : EmptyExpression.LValueMemberAccess;
6363 InstanceExpression = InstanceExpression.ResolveLValue (ec, right_side);
6365 InstanceExpression = InstanceExpression.Resolve (ec, ResolveFlags.VariableOrValue);
6368 if (InstanceExpression == null)
6372 DoBestMemberChecks (ec, spec);
6374 if (conditional_access_receiver)
6375 ec.With (ResolveContext.Options.DontSetConditionalAccessReceiver, false);
6378 var fb = spec as FixedFieldSpec;
6379 IVariableReference var = InstanceExpression as IVariableReference;
6382 IFixedExpression fe = InstanceExpression as IFixedExpression;
6383 if (!ec.HasSet (ResolveContext.Options.FixedInitializerScope) && (fe == null || !fe.IsFixed)) {
6384 ec.Report.Error (1666, loc, "You cannot use fixed size buffers contained in unfixed expressions. Try using the fixed statement");
6387 if (InstanceExpression.eclass != ExprClass.Variable) {
6388 ec.Report.SymbolRelatedToPreviousError (spec);
6389 ec.Report.Error (1708, loc, "`{0}': Fixed size buffers can only be accessed through locals or fields",
6390 TypeManager.GetFullNameSignature (spec));
6391 } else if (var != null && var.IsHoisted) {
6392 AnonymousMethodExpression.Error_AddressOfCapturedVar (ec, var, loc);
6395 return new FixedBufferPtr (this, fb.ElementType, loc).Resolve (ec);
6399 // Set flow-analysis variable info for struct member access. It will be check later
6400 // for precise error reporting
6402 if (var != null && var.VariableInfo != null && InstanceExpression.Type.IsStruct) {
6403 variable_info = var.VariableInfo.GetStructFieldInfo (Name);
6406 if (conditional_access_receiver)
6407 type = LiftMemberType (ec, type);
6409 if (ConditionalAccess && InstanceExpression != null && InstanceExpression.IsNull)
6410 return Constant.CreateConstantFromValue (type, null, loc);
6412 eclass = ExprClass.Variable;
6416 public override void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
6418 spec.CheckObsoleteness (rc, expr.Location);
6421 public void SetFieldAssigned (FlowAnalysisContext fc)
6426 bool lvalue_instance = spec.DeclaringType.IsStruct;
6427 if (lvalue_instance) {
6428 var var = InstanceExpression as IVariableReference;
6429 if (var != null && var.VariableInfo != null) {
6430 fc.SetStructFieldAssigned (var.VariableInfo, Name);
6434 var fe = InstanceExpression as FieldExpr;
6436 Expression instance;
6439 instance = fe.InstanceExpression;
6440 var fe_instance = instance as FieldExpr;
6441 if ((fe_instance != null && !fe_instance.IsStatic) || instance is LocalVariableReference) {
6442 if (TypeSpec.IsReferenceType (fe.Type) && instance.Type.IsStruct) {
6443 var var = InstanceExpression as IVariableReference;
6444 if (var != null && var.VariableInfo == null) {
6445 var var_inst = instance as IVariableReference;
6446 if (var_inst == null || (var_inst.VariableInfo != null && !fc.IsDefinitelyAssigned (var_inst.VariableInfo)))
6447 fc.Report.Warning (1060, 1, fe.loc, "Use of possibly unassigned field `{0}'", fe.Name);
6451 if (fe_instance != null) {
6460 if (instance != null && TypeSpec.IsReferenceType (instance.Type))
6461 instance.FlowAnalysis (fc);
6463 if (TypeSpec.IsReferenceType (InstanceExpression.Type))
6464 InstanceExpression.FlowAnalysis (fc);
6468 Expression Error_AssignToReadonly (ResolveContext rc, Expression right_side)
6470 // The return value is always null. Returning a value simplifies calling code.
6472 if (right_side == EmptyExpression.OutAccess) {
6474 rc.Report.Error (199, loc, "A static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
6475 GetSignatureForError ());
6477 rc.Report.Error (192, loc, "A readonly field `{0}' cannot be passed ref or out (except in a constructor)",
6478 GetSignatureForError ());
6484 if (right_side == EmptyExpression.LValueMemberAccess) {
6485 // Already reported as CS1648/CS1650
6489 if (right_side == EmptyExpression.LValueMemberOutAccess) {
6491 rc.Report.Error (1651, loc, "Fields of static readonly field `{0}' cannot be passed ref or out (except in a static constructor)",
6492 GetSignatureForError ());
6494 rc.Report.Error (1649, loc, "Members of readonly field `{0}' cannot be passed ref or out (except in a constructor)",
6495 GetSignatureForError ());
6501 rc.Report.Error (198, loc, "A static readonly field `{0}' cannot be assigned to (except in a static constructor or a variable initializer)",
6502 GetSignatureForError ());
6504 rc.Report.Error (191, loc, "A readonly field `{0}' cannot be assigned to (except in a constructor or a variable initializer)",
6505 GetSignatureForError ());
6511 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
6513 if (HasConditionalAccess ())
6514 Error_NullPropagatingLValue (ec);
6516 if (spec is FixedFieldSpec) {
6517 // It could be much better error message but we want to be error compatible
6518 Error_ValueAssignment (ec, right_side);
6521 Expression e = DoResolve (ec, right_side);
6526 spec.MemberDefinition.SetIsAssigned ();
6528 if ((right_side == EmptyExpression.UnaryAddress || right_side == EmptyExpression.OutAccess) &&
6529 (spec.Modifiers & Modifiers.VOLATILE) != 0) {
6530 ec.Report.Warning (420, 1, loc,
6531 "`{0}': A volatile field references will not be treated as volatile",
6532 spec.GetSignatureForError ());
6535 if (spec.IsReadOnly) {
6536 // InitOnly fields can only be assigned in constructors or initializers
6537 if (!ec.HasAny (ResolveContext.Options.FieldInitializerScope | ResolveContext.Options.ConstructorScope))
6538 return Error_AssignToReadonly (ec, right_side);
6540 if (ec.HasSet (ResolveContext.Options.ConstructorScope)) {
6542 // InitOnly fields cannot be assigned-to in a different constructor from their declaring type
6543 if (ec.CurrentMemberDefinition.Parent.PartialContainer.Definition != spec.DeclaringType.GetDefinition ())
6544 return Error_AssignToReadonly (ec, right_side);
6545 // static InitOnly fields cannot be assigned-to in an instance constructor
6546 if (IsStatic && !ec.IsStatic)
6547 return Error_AssignToReadonly (ec, right_side);
6548 // instance constructors can't modify InitOnly fields of other instances of the same type
6549 if (!IsStatic && !(InstanceExpression is This))
6550 return Error_AssignToReadonly (ec, right_side);
6554 if (right_side == EmptyExpression.OutAccess && IsMarshalByRefAccess (ec)) {
6555 ec.Report.SymbolRelatedToPreviousError (spec.DeclaringType);
6556 ec.Report.Warning (197, 1, loc,
6557 "Passing `{0}' as ref or out or taking its address may cause a runtime exception because it is a field of a marshal-by-reference class",
6558 GetSignatureForError ());
6561 eclass = ExprClass.Variable;
6565 public override void FlowAnalysis (FlowAnalysisContext fc)
6567 var var = InstanceExpression as IVariableReference;
6569 var vi = var.VariableInfo;
6570 if (vi != null && !fc.IsStructFieldDefinitelyAssigned (vi, Name)) {
6571 fc.Report.Error (170, loc, "Use of possibly unassigned field `{0}'", Name);
6575 if (TypeSpec.IsValueType (InstanceExpression.Type)) {
6576 var le = SkipLeftValueTypeAccess (InstanceExpression);
6578 le.FlowAnalysis (fc);
6584 var da = conditional_access_receiver ? fc.BranchDefiniteAssignment () : null;
6586 base.FlowAnalysis (fc);
6588 if (conditional_access_receiver)
6589 fc.DefiniteAssignment = da;
6592 static Expression SkipLeftValueTypeAccess (Expression expr)
6594 if (!TypeSpec.IsValueType (expr.Type))
6597 if (expr is VariableReference)
6600 var fe = expr as FieldExpr;
6604 if (fe.InstanceExpression == null)
6607 return SkipLeftValueTypeAccess (fe.InstanceExpression);
6610 public override int GetHashCode ()
6612 return spec.GetHashCode ();
6615 public bool IsFixed {
6618 // A variable of the form V.I is fixed when V is a fixed variable of a struct type
6620 IVariableReference variable = InstanceExpression as IVariableReference;
6621 if (variable != null)
6622 return InstanceExpression.Type.IsStruct && variable.IsFixed;
6624 IFixedExpression fe = InstanceExpression as IFixedExpression;
6625 return fe != null && fe.IsFixed;
6629 public override bool Equals (object obj)
6631 FieldExpr fe = obj as FieldExpr;
6635 if (spec != fe.spec)
6638 if (InstanceExpression == null || fe.InstanceExpression == null)
6641 return InstanceExpression.Equals (fe.InstanceExpression);
6644 public void Emit (EmitContext ec, bool leave_copy)
6646 bool is_volatile = (spec.Modifiers & Modifiers.VOLATILE) != 0;
6650 ec.Emit (OpCodes.Volatile);
6652 ec.Emit (OpCodes.Ldsfld, spec);
6654 var ca = ec.ConditionalAccess;
6657 if (conditional_access_receiver)
6658 ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());
6660 EmitInstance (ec, false);
6663 // Optimization for build-in types
6664 if (type.IsStruct && type == ec.CurrentType && InstanceExpression.Type == type) {
6665 ec.EmitLoadFromPtr (type);
6667 var ff = spec as FixedFieldSpec;
6669 ec.Emit (OpCodes.Ldflda, spec);
6670 ec.Emit (OpCodes.Ldflda, ff.Element);
6673 ec.Emit (OpCodes.Volatile);
6675 ec.Emit (OpCodes.Ldfld, spec);
6679 if (conditional_access_receiver) {
6680 ec.CloseConditionalAccess (type.IsNullableType && type != spec.MemberType ? type : null);
6681 ec.ConditionalAccess = ca;
6686 ec.Emit (OpCodes.Dup);
6688 temp = new LocalTemporary (this.Type);
6694 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool isCompound)
6696 bool has_await_source = ec.HasSet (BuilderContext.Options.AsyncBody) && source.ContainsEmitWithAwait ();
6697 if (isCompound && !(source is DynamicExpressionStatement) && !has_await_source) {
6702 if (ConditionalAccess)
6703 throw new NotImplementedException ("null operator assignment");
6705 if (has_await_source)
6706 source = source.EmitToField (ec);
6708 EmitInstance (ec, prepared);
6713 if (leave_copy || ec.NotifyEvaluatorOnStore) {
6714 ec.Emit (OpCodes.Dup);
6716 temp = new LocalTemporary (this.Type);
6721 if ((spec.Modifiers & Modifiers.VOLATILE) != 0)
6722 ec.Emit (OpCodes.Volatile);
6724 spec.MemberDefinition.SetIsAssigned ();
6727 ec.Emit (OpCodes.Stsfld, spec);
6729 ec.Emit (OpCodes.Stfld, spec);
6731 if (ec.NotifyEvaluatorOnStore) {
6733 throw new NotImplementedException ("instance field write");
6736 ec.Emit (OpCodes.Dup);
6738 ec.Module.Evaluator.EmitValueChangedCallback (ec, Name, type, loc);
6749 // Emits store to field with prepared values on stack
6751 public void EmitAssignFromStack (EmitContext ec)
6754 ec.Emit (OpCodes.Stsfld, spec);
6756 ec.Emit (OpCodes.Stfld, spec);
6760 public override void Emit (EmitContext ec)
6765 public override void EmitSideEffect (EmitContext ec)
6767 bool is_volatile = (spec.Modifiers & Modifiers.VOLATILE) != 0;
6769 if (is_volatile) // || is_marshal_by_ref ())
6770 base.EmitSideEffect (ec);
6773 public virtual void AddressOf (EmitContext ec, AddressOp mode)
6775 if ((mode & AddressOp.Store) != 0)
6776 spec.MemberDefinition.SetIsAssigned ();
6777 if ((mode & AddressOp.Load) != 0)
6778 spec.MemberDefinition.SetIsUsed ();
6781 // Handle initonly fields specially: make a copy and then
6782 // get the address of the copy.
6785 if (spec.IsReadOnly){
6787 if (ec.HasSet (EmitContext.Options.ConstructorScope) && spec.DeclaringType == ec.CurrentType) {
6799 var temp = ec.GetTemporaryLocal (type);
6800 ec.Emit (OpCodes.Stloc, temp);
6801 ec.Emit (OpCodes.Ldloca, temp);
6807 ec.Emit (OpCodes.Ldsflda, spec);
6810 EmitInstance (ec, false);
6811 ec.Emit (OpCodes.Ldflda, spec);
6815 public SLE.Expression MakeAssignExpression (BuilderContext ctx, Expression source)
6817 return MakeExpression (ctx);
6820 public override SLE.Expression MakeExpression (BuilderContext ctx)
6823 return base.MakeExpression (ctx);
6825 return SLE.Expression.Field (
6826 IsStatic ? null : InstanceExpression.MakeExpression (ctx),
6827 spec.GetMetaInfo ());
6831 public override void SetTypeArguments (ResolveContext ec, TypeArguments ta)
6833 Error_TypeArgumentsCannotBeUsed (ec, "field", GetSignatureForError (), loc);
6839 // Expression that evaluates to a Property.
6841 // This is not an LValue because we need to re-write the expression. We
6842 // can not take data from the stack and store it.
6844 sealed class PropertyExpr : PropertyOrIndexerExpr<PropertySpec>
6846 Arguments arguments;
6847 FieldExpr backing_field;
6849 public PropertyExpr (PropertySpec spec, Location l)
6852 best_candidate = spec;
6853 type = spec.MemberType;
6858 protected override Arguments Arguments {
6867 protected override TypeSpec DeclaringType {
6869 return best_candidate.DeclaringType;
6873 public override string Name {
6875 return best_candidate.Name;
6879 public bool IsAutoPropertyAccess {
6881 var prop = best_candidate.MemberDefinition as Property;
6882 return prop != null && prop.BackingField != null;
6886 public override bool IsInstance {
6892 public override bool IsStatic {
6894 return best_candidate.IsStatic;
6898 public override string KindName {
6899 get { return "property"; }
6902 public PropertySpec PropertyInfo {
6904 return best_candidate;
6910 public override MethodGroupExpr CanReduceLambda (AnonymousMethodBody body)
6912 if (best_candidate == null || !(best_candidate.IsStatic || InstanceExpression is This))
6915 var args_count = arguments == null ? 0 : arguments.Count;
6916 if (args_count != body.Parameters.Count && args_count == 0)
6919 var mg = MethodGroupExpr.CreatePredefined (best_candidate.Get, DeclaringType, loc);
6920 mg.InstanceExpression = InstanceExpression;
6925 public static PropertyExpr CreatePredefined (PropertySpec spec, Location loc)
6927 return new PropertyExpr (spec, loc) {
6933 public override Expression CreateExpressionTree (ResolveContext ec)
6935 if (ConditionalAccess) {
6936 Error_NullShortCircuitInsideExpressionTree (ec);
6940 if (IsSingleDimensionalArrayLength ()) {
6941 args = new Arguments (1);
6942 args.Add (new Argument (InstanceExpression.CreateExpressionTree (ec)));
6943 return CreateExpressionFactoryCall (ec, "ArrayLength", args);
6946 args = new Arguments (2);
6947 if (InstanceExpression == null)
6948 args.Add (new Argument (new NullLiteral (loc)));
6950 args.Add (new Argument (InstanceExpression.CreateExpressionTree (ec)));
6951 args.Add (new Argument (new TypeOfMethod (Getter, loc)));
6952 return CreateExpressionFactoryCall (ec, "Property", args);
6955 public Expression CreateSetterTypeOfExpression (ResolveContext rc)
6957 DoResolveLValue (rc, null);
6958 return new TypeOfMethod (Setter, loc);
6961 public override string GetSignatureForError ()
6963 return best_candidate.GetSignatureForError ();
6966 public override SLE.Expression MakeAssignExpression (BuilderContext ctx, Expression source)
6969 return base.MakeExpression (ctx);
6971 return SLE.Expression.Property (InstanceExpression.MakeExpression (ctx), (MethodInfo) Setter.GetMetaInfo ());
6975 public override SLE.Expression MakeExpression (BuilderContext ctx)
6978 return base.MakeExpression (ctx);
6980 return SLE.Expression.Property (InstanceExpression.MakeExpression (ctx), (MethodInfo) Getter.GetMetaInfo ());
6984 void Error_PropertyNotValid (ResolveContext ec)
6986 ec.Report.SymbolRelatedToPreviousError (best_candidate);
6987 ec.Report.Error (1546, loc, "Property or event `{0}' is not supported by the C# language",
6988 GetSignatureForError ());
6991 bool IsSingleDimensionalArrayLength ()
6993 if (best_candidate.DeclaringType.BuiltinType != BuiltinTypeSpec.Type.Array || !best_candidate.HasGet || Name != "Length")
6996 ArrayContainer ac = InstanceExpression.Type as ArrayContainer;
6997 return ac != null && ac.Rank == 1;
7000 public override void Emit (EmitContext ec, bool leave_copy)
7003 // Special case: length of single dimension array property is turned into ldlen
7005 if (IsSingleDimensionalArrayLength ()) {
7006 if (conditional_access_receiver) {
7007 ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());
7010 EmitInstance (ec, false);
7012 ec.Emit (OpCodes.Ldlen);
7013 ec.Emit (OpCodes.Conv_I4);
7015 if (conditional_access_receiver) {
7016 ec.CloseConditionalAccess (type);
7022 base.Emit (ec, leave_copy);
7025 public override void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool isCompound)
7027 if (backing_field != null) {
7028 backing_field.EmitAssign (ec, source, leave_copy, false);
7033 LocalTemporary await_source_arg = null;
7035 if (isCompound && !(source is DynamicExpressionStatement)) {
7036 emitting_compound_assignment = true;
7039 if (has_await_arguments) {
7040 await_source_arg = new LocalTemporary (Type);
7041 await_source_arg.Store (ec);
7043 args = new Arguments (1);
7044 args.Add (new Argument (await_source_arg));
7047 temp = await_source_arg;
7050 has_await_arguments = false;
7055 ec.Emit (OpCodes.Dup);
7056 temp = new LocalTemporary (this.Type);
7061 args = arguments ?? new Arguments (1);
7065 temp = new LocalTemporary (this.Type);
7067 args.Add (new Argument (temp));
7069 args.Add (new Argument (source));
7073 emitting_compound_assignment = false;
7075 var call = new CallEmitter ();
7076 call.InstanceExpression = InstanceExpression;
7078 call.InstanceExpressionOnStack = true;
7080 if (ConditionalAccess) {
7081 call.ConditionalAccess = true;
7085 call.Emit (ec, Setter, args, loc);
7087 call.EmitStatement (ec, Setter, args, loc);
7094 if (await_source_arg != null) {
7095 await_source_arg.Release (ec);
7099 public override void FlowAnalysis (FlowAnalysisContext fc)
7101 var prop = best_candidate.MemberDefinition as Property;
7102 if (prop != null && prop.BackingField != null) {
7103 var var = InstanceExpression as IVariableReference;
7105 var vi = var.VariableInfo;
7106 if (vi != null && !fc.IsStructFieldDefinitelyAssigned (vi, prop.BackingField.Name)) {
7107 fc.Report.Error (8079, loc, "Use of possibly unassigned auto-implemented property `{0}'", Name);
7111 if (TypeSpec.IsValueType (InstanceExpression.Type) && InstanceExpression is VariableReference)
7116 var da = conditional_access_receiver ? fc.BranchDefiniteAssignment () : null;
7118 base.FlowAnalysis (fc);
7120 if (conditional_access_receiver)
7121 fc.DefiniteAssignment = da;
7124 protected override Expression OverloadResolve (ResolveContext rc, Expression right_side)
7126 eclass = ExprClass.PropertyAccess;
7128 if (best_candidate.IsNotCSharpCompatible) {
7129 Error_PropertyNotValid (rc);
7132 ResolveInstanceExpression (rc, right_side);
7134 if ((best_candidate.Modifiers & (Modifiers.ABSTRACT | Modifiers.VIRTUAL)) != 0 && best_candidate.DeclaringType != InstanceExpression.Type) {
7135 var filter = new MemberFilter (best_candidate.Name, 0, MemberKind.Property, null, null);
7136 var p = MemberCache.FindMember (InstanceExpression.Type, filter, BindingRestriction.InstanceOnly | BindingRestriction.OverrideOnly) as PropertySpec;
7138 type = p.MemberType;
7142 DoBestMemberChecks (rc, best_candidate);
7144 // Handling of com-imported properties with any number of default property parameters
7145 if (best_candidate.HasGet && !best_candidate.Get.Parameters.IsEmpty) {
7146 var p = best_candidate.Get.Parameters;
7147 arguments = new Arguments (p.Count);
7148 for (int i = 0; i < p.Count; ++i) {
7149 arguments.Add (new Argument (OverloadResolver.ResolveDefaultValueArgument (rc, p.Types [i], p.FixedParameters [i].DefaultValue, loc)));
7151 } else if (best_candidate.HasSet && best_candidate.Set.Parameters.Count > 1) {
7152 var p = best_candidate.Set.Parameters;
7153 arguments = new Arguments (p.Count - 1);
7154 for (int i = 0; i < p.Count - 1; ++i) {
7155 arguments.Add (new Argument (OverloadResolver.ResolveDefaultValueArgument (rc, p.Types [i], p.FixedParameters [i].DefaultValue, loc)));
7162 protected override bool ResolveAutopropertyAssignment (ResolveContext rc, Expression rhs)
7164 if (!rc.HasSet (ResolveContext.Options.ConstructorScope))
7167 var prop = best_candidate.MemberDefinition as Property;
7168 if (prop == null || prop.Parent.PartialContainer != rc.CurrentMemberDefinition.Parent.PartialContainer) {
7169 var ps = MemberCache.FindMember (rc.CurrentType, MemberFilter.Property (best_candidate.Name, best_candidate.MemberType), BindingRestriction.DeclaredOnly) as PropertySpec;
7173 prop = (Property)ps.MemberDefinition;
7176 var spec = prop.BackingField;
7180 if (rc.IsStatic != spec.IsStatic)
7183 if (!spec.IsStatic && (!(InstanceExpression is This) || InstanceExpression is BaseThis))
7186 backing_field = new FieldExpr (prop.BackingField, loc);
7187 backing_field.ResolveLValue (rc, rhs);
7191 public override void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
7193 if (!best_candidate.IsAccessible (rc))
7194 ErrorIsInaccesible (rc, best_candidate.GetSignatureForError (), expr.Location);
7196 best_candidate.CheckObsoleteness (rc, expr.Location);
7199 public void SetBackingFieldAssigned (FlowAnalysisContext fc)
7201 if (backing_field != null) {
7202 backing_field.SetFieldAssigned (fc);
7206 if (!IsAutoPropertyAccess)
7209 var prop = best_candidate.MemberDefinition as Property;
7210 if (prop != null && prop.BackingField != null) {
7211 bool lvalue_instance = best_candidate.DeclaringType.IsStruct;
7212 if (lvalue_instance) {
7213 var var = InstanceExpression as IVariableReference;
7214 if (var != null && var.VariableInfo != null) {
7215 fc.SetStructFieldAssigned (var.VariableInfo, prop.BackingField.Name);
7221 public override void SetTypeArguments (ResolveContext ec, TypeArguments ta)
7223 Error_TypeArgumentsCannotBeUsed (ec, "property", GetSignatureForError (), loc);
7227 abstract class PropertyOrIndexerExpr<T> : MemberExpr, IDynamicAssign where T : PropertySpec
7229 // getter and setter can be different for base calls
7230 MethodSpec getter, setter;
7231 protected T best_candidate;
7233 protected LocalTemporary temp;
7234 protected bool emitting_compound_assignment;
7235 protected bool has_await_arguments;
7237 protected PropertyOrIndexerExpr (Location l)
7244 protected abstract Arguments Arguments { get; set; }
7246 public MethodSpec Getter {
7255 public MethodSpec Setter {
7266 protected override Expression DoResolve (ResolveContext ec)
7268 if (eclass == ExprClass.Unresolved) {
7269 ResolveConditionalAccessReceiver (ec);
7271 var expr = OverloadResolve (ec, null);
7276 using (ec.With (ResolveContext.Options.DontSetConditionalAccessReceiver, conditional_access_receiver))
7277 return expr.Resolve (ec);
7280 if (conditional_access_receiver) {
7281 type = LiftMemberType (ec, type);
7285 if (!ResolveGetter (ec))
7291 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
7293 if (HasConditionalAccess ())
7294 Error_NullPropagatingLValue (rc);
7296 if (right_side == EmptyExpression.OutAccess) {
7297 // TODO: best_candidate can be null at this point
7298 INamedBlockVariable variable = null;
7299 if (best_candidate != null && rc.CurrentBlock.ParametersBlock.TopBlock.GetLocalName (best_candidate.Name, rc.CurrentBlock, ref variable) && variable is Linq.RangeVariable) {
7300 rc.Report.Error (1939, loc, "A range variable `{0}' may not be passes as `ref' or `out' parameter",
7301 best_candidate.Name);
7303 right_side.DoResolveLValue (rc, this);
7308 if (eclass == ExprClass.Unresolved) {
7309 var expr = OverloadResolve (rc, right_side);
7314 return expr.ResolveLValue (rc, right_side);
7316 ResolveInstanceExpression (rc, right_side);
7319 if (!best_candidate.HasSet) {
7320 if (ResolveAutopropertyAssignment (rc, right_side))
7323 rc.Report.Error (200, loc, "Property or indexer `{0}' cannot be assigned to (it is read-only)",
7324 GetSignatureForError ());
7328 if (!best_candidate.Set.IsAccessible (rc) || !best_candidate.Set.DeclaringType.IsAccessible (rc)) {
7329 if (best_candidate.HasDifferentAccessibility) {
7330 rc.Report.SymbolRelatedToPreviousError (best_candidate.Set);
7331 rc.Report.Error (272, loc, "The property or indexer `{0}' cannot be used in this context because the set accessor is inaccessible",
7332 GetSignatureForError ());
7334 rc.Report.SymbolRelatedToPreviousError (best_candidate.Set);
7335 ErrorIsInaccesible (rc, best_candidate.GetSignatureForError (), loc);
7339 if (best_candidate.HasDifferentAccessibility)
7340 CheckProtectedMemberAccess (rc, best_candidate.Set);
7342 setter = CandidateToBaseOverride (rc, best_candidate.Set);
7346 void EmitConditionalAccess (EmitContext ec, ref CallEmitter call, MethodSpec method, Arguments arguments)
7348 var ca = ec.ConditionalAccess;
7349 ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());
7351 call.Emit (ec, method, arguments, loc);
7353 ec.CloseConditionalAccess (method.ReturnType != type && type.IsNullableType ? type : null);
7354 ec.ConditionalAccess = ca;
7358 // Implements the IAssignMethod interface for assignments
7360 public virtual void Emit (EmitContext ec, bool leave_copy)
7362 var call = new CallEmitter ();
7363 call.ConditionalAccess = ConditionalAccess;
7364 call.InstanceExpression = InstanceExpression;
7365 if (has_await_arguments)
7366 call.HasAwaitArguments = true;
7368 call.DuplicateArguments = emitting_compound_assignment;
7370 if (conditional_access_receiver)
7371 EmitConditionalAccess (ec, ref call, Getter, Arguments);
7373 call.Emit (ec, Getter, Arguments, loc);
7375 if (call.HasAwaitArguments) {
7376 InstanceExpression = call.InstanceExpression;
7377 Arguments = call.EmittedArguments;
7378 has_await_arguments = true;
7382 ec.Emit (OpCodes.Dup);
7383 temp = new LocalTemporary (Type);
7388 public abstract void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool isCompound);
7390 public override void Emit (EmitContext ec)
7395 protected override FieldExpr EmitToFieldSource (EmitContext ec)
7397 has_await_arguments = true;
7402 public abstract SLE.Expression MakeAssignExpression (BuilderContext ctx, Expression source);
7404 protected abstract Expression OverloadResolve (ResolveContext rc, Expression right_side);
7406 bool ResolveGetter (ResolveContext rc)
7408 if (!best_candidate.HasGet) {
7409 if (InstanceExpression != EmptyExpression.Null) {
7410 rc.Report.SymbolRelatedToPreviousError (best_candidate);
7411 rc.Report.Error (154, loc, "The property or indexer `{0}' cannot be used in this context because it lacks the `get' accessor",
7412 best_candidate.GetSignatureForError ());
7415 } else if (!best_candidate.Get.IsAccessible (rc) || !best_candidate.Get.DeclaringType.IsAccessible (rc)) {
7416 if (best_candidate.HasDifferentAccessibility) {
7417 rc.Report.SymbolRelatedToPreviousError (best_candidate.Get);
7418 rc.Report.Error (271, loc, "The property or indexer `{0}' cannot be used in this context because the get accessor is inaccessible",
7419 TypeManager.CSharpSignature (best_candidate));
7421 rc.Report.SymbolRelatedToPreviousError (best_candidate.Get);
7422 ErrorIsInaccesible (rc, best_candidate.Get.GetSignatureForError (), loc);
7426 if (best_candidate.HasDifferentAccessibility) {
7427 CheckProtectedMemberAccess (rc, best_candidate.Get);
7430 getter = CandidateToBaseOverride (rc, best_candidate.Get);
7434 protected virtual bool ResolveAutopropertyAssignment (ResolveContext rc, Expression rhs)
7441 /// Fully resolved expression that evaluates to an Event
7443 public class EventExpr : MemberExpr, IAssignMethod
7445 readonly EventSpec spec;
7448 public EventExpr (EventSpec spec, Location loc)
7456 protected override TypeSpec DeclaringType {
7458 return spec.DeclaringType;
7462 public override string Name {
7468 public override bool IsInstance {
7470 return !spec.IsStatic;
7474 public override bool IsStatic {
7476 return spec.IsStatic;
7480 public override string KindName {
7481 get { return "event"; }
7484 public MethodSpec Operator {
7492 public override MemberExpr ResolveMemberAccess (ResolveContext ec, Expression left, SimpleName original)
7495 // If the event is local to this class and we are not lhs of +=/-= we transform ourselves into a FieldExpr
7497 if (!ec.HasSet (ResolveContext.Options.CompoundAssignmentScope)) {
7498 if (spec.BackingField != null &&
7499 (spec.DeclaringType == ec.CurrentType || TypeManager.IsNestedChildOf (ec.CurrentType, spec.DeclaringType.MemberDefinition))) {
7501 spec.MemberDefinition.SetIsUsed ();
7503 spec.CheckObsoleteness (ec, loc);
7505 if ((spec.Modifiers & (Modifiers.ABSTRACT | Modifiers.EXTERN)) != 0)
7506 Error_AssignmentEventOnly (ec);
7508 FieldExpr ml = new FieldExpr (spec.BackingField, loc);
7510 InstanceExpression = null;
7512 return ml.ResolveMemberAccess (ec, left, original);
7516 return base.ResolveMemberAccess (ec, left, original);
7519 public override Expression CreateExpressionTree (ResolveContext ec)
7521 throw new NotSupportedException ("ET");
7524 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7526 if (right_side == EmptyExpression.EventAddition) {
7527 op = spec.AccessorAdd;
7528 } else if (right_side == EmptyExpression.EventSubtraction) {
7529 op = spec.AccessorRemove;
7533 Error_AssignmentEventOnly (ec);
7537 if (HasConditionalAccess ())
7538 Error_NullPropagatingLValue (ec);
7540 op = CandidateToBaseOverride (ec, op);
7544 protected override Expression DoResolve (ResolveContext ec)
7546 eclass = ExprClass.EventAccess;
7547 type = spec.MemberType;
7549 ResolveInstanceExpression (ec, null);
7551 if (!ec.HasSet (ResolveContext.Options.CompoundAssignmentScope)) {
7552 Error_AssignmentEventOnly (ec);
7555 DoBestMemberChecks (ec, spec);
7559 public override void Emit (EmitContext ec)
7561 throw new NotSupportedException ();
7562 //Error_CannotAssign ();
7565 #region IAssignMethod Members
7567 public void Emit (EmitContext ec, bool leave_copy)
7569 throw new NotImplementedException ();
7572 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool isCompound)
7574 if (leave_copy || !isCompound)
7575 throw new NotImplementedException ("EventExpr::EmitAssign");
7577 Arguments args = new Arguments (1);
7578 args.Add (new Argument (source));
7580 // TODO: Wrong, needs receiver
7581 // if (NullShortCircuit) {
7582 // ec.ConditionalAccess = new ConditionalAccessContext (type, ec.DefineLabel ());
7585 var call = new CallEmitter ();
7586 call.InstanceExpression = InstanceExpression;
7587 call.ConditionalAccess = ConditionalAccess;
7588 call.EmitStatement (ec, op, args, loc);
7590 // if (NullShortCircuit)
7591 // ec.CloseConditionalAccess (null);
7596 void Error_AssignmentEventOnly (ResolveContext ec)
7598 if (spec.DeclaringType == ec.CurrentType || TypeManager.IsNestedChildOf (ec.CurrentType, spec.DeclaringType.MemberDefinition)) {
7599 ec.Report.Error (79, loc,
7600 "The event `{0}' can only appear on the left hand side of `+=' or `-=' operator",
7601 GetSignatureForError ());
7603 ec.Report.Error (70, loc,
7604 "The event `{0}' can only appear on the left hand side of += or -= when used outside of the type `{1}'",
7605 GetSignatureForError (), spec.DeclaringType.GetSignatureForError ());
7609 protected override void Error_CannotCallAbstractBase (ResolveContext rc, string name)
7611 name = name.Substring (0, name.LastIndexOf ('.'));
7612 base.Error_CannotCallAbstractBase (rc, name);
7615 public override string GetSignatureForError ()
7617 return TypeManager.CSharpSignature (spec);
7620 public override void ResolveNameOf (ResolveContext rc, ATypeNameExpression expr)
7622 spec.CheckObsoleteness (rc, expr.Location);
7625 public override void SetTypeArguments (ResolveContext ec, TypeArguments ta)
7627 Error_TypeArgumentsCannotBeUsed (ec, "event", GetSignatureForError (), loc);
7631 public class TemporaryVariableReference : VariableReference
7633 public class Declarator : Statement
7635 TemporaryVariableReference variable;
7637 public Declarator (TemporaryVariableReference variable)
7639 this.variable = variable;
7643 protected override void DoEmit (EmitContext ec)
7645 variable.li.CreateBuilder (ec);
7648 public override void Emit (EmitContext ec)
7650 // Don't create sequence point
7654 protected override bool DoFlowAnalysis (FlowAnalysisContext fc)
7659 protected override void CloneTo (CloneContext clonectx, Statement target)
7667 public TemporaryVariableReference (LocalVariable li, Location loc)
7670 this.type = li.Type;
7674 public override bool IsLockedByStatement {
7682 public LocalVariable LocalInfo {
7688 public static TemporaryVariableReference Create (TypeSpec type, Block block, Location loc, bool writeToSymbolFile = false)
7690 var li = LocalVariable.CreateCompilerGenerated (type, block, loc, writeToSymbolFile);
7691 return new TemporaryVariableReference (li, loc);
7694 protected override Expression DoResolve (ResolveContext ec)
7696 eclass = ExprClass.Variable;
7699 // Don't capture temporary variables except when using
7700 // state machine redirection and block yields
7702 if (ec.CurrentAnonymousMethod is StateMachineInitializer &&
7703 (ec.CurrentBlock.Explicit.HasYield || ec.CurrentBlock.Explicit.HasAwait) &&
7704 ec.IsVariableCapturingRequired) {
7705 AnonymousMethodStorey storey = li.Block.Explicit.CreateAnonymousMethodStorey (ec);
7706 storey.CaptureLocalVariable (ec, li);
7712 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
7714 return Resolve (ec);
7717 public override void Emit (EmitContext ec)
7719 li.CreateBuilder (ec);
7724 public void EmitAssign (EmitContext ec, Expression source)
7726 li.CreateBuilder (ec);
7728 EmitAssign (ec, source, false, false);
7731 public override HoistedVariable GetHoistedVariable (AnonymousExpression ae)
7733 return li.HoistedVariant;
7736 public override bool IsFixed {
7737 get { return true; }
7740 public override bool IsRef {
7741 get { return false; }
7744 public override string Name {
7745 get { throw new NotImplementedException (); }
7748 public override void SetHasAddressTaken ()
7750 throw new NotImplementedException ();
7753 protected override ILocalVariable Variable {
7757 public override VariableInfo VariableInfo {
7758 get { return null; }
7763 /// Handles `var' contextual keyword; var becomes a keyword only
7764 /// if no type called var exists in a variable scope
7766 class VarExpr : SimpleName
7768 public VarExpr (Location loc)
7773 public bool InferType (ResolveContext ec, Expression right_side)
7776 throw new InternalErrorException ("An implicitly typed local variable could not be redefined");
7778 type = right_side.Type;
7779 if (type == InternalType.NullLiteral || type.Kind == MemberKind.Void || type == InternalType.AnonymousMethod || type == InternalType.MethodGroup) {
7780 ec.Report.Error (815, loc,
7781 "An implicitly typed local variable declaration cannot be initialized with `{0}'",
7782 type.GetSignatureForError ());
7783 type = InternalType.ErrorType;
7787 eclass = ExprClass.Variable;
7791 protected override void Error_TypeOrNamespaceNotFound (IMemberContext ec)
7793 if (ec.Module.Compiler.Settings.Version < LanguageVersion.V_3)
7794 base.Error_TypeOrNamespaceNotFound (ec);
7796 ec.Module.Compiler.Report.Error (825, loc, "The contextual keyword `var' may only appear within a local variable declaration");