2 // generic.cs: Generics support
4 // Authors: Martin Baulig (martin@ximian.com)
5 // Miguel de Icaza (miguel@ximian.com)
7 // Licensed under the terms of the GNU GPL
9 // (C) 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
10 // (C) 2004 Novell, Inc
13 using System.Reflection;
14 using System.Reflection.Emit;
15 using System.Globalization;
16 using System.Collections;
18 using System.Text.RegularExpressions;
20 namespace Mono.CSharp {
23 /// Abstract base class for type parameter constraints.
24 /// The type parameter can come from a generic type definition or from reflection.
26 public abstract class GenericConstraints {
27 public abstract string TypeParameter {
31 public abstract GenericParameterAttributes Attributes {
35 public bool HasConstructorConstraint {
36 get { return (Attributes & GenericParameterAttributes.DefaultConstructorConstraint) != 0; }
39 public bool HasReferenceTypeConstraint {
40 get { return (Attributes & GenericParameterAttributes.ReferenceTypeConstraint) != 0; }
43 public bool HasValueTypeConstraint {
44 get { return (Attributes & GenericParameterAttributes.NotNullableValueTypeConstraint) != 0; }
47 public virtual bool HasClassConstraint {
48 get { return ClassConstraint != null; }
51 public abstract Type ClassConstraint {
55 public abstract Type[] InterfaceConstraints {
59 public abstract Type EffectiveBaseClass {
64 // Returns whether the type parameter is "known to be a reference type".
66 public virtual bool IsReferenceType {
68 if (HasReferenceTypeConstraint)
70 if (HasValueTypeConstraint)
73 if (ClassConstraint != null) {
74 if (ClassConstraint.IsValueType)
77 if (ClassConstraint != TypeManager.object_type)
81 foreach (Type t in InterfaceConstraints) {
82 if (!t.IsGenericParameter)
85 GenericConstraints gc = TypeManager.GetTypeParameterConstraints (t);
86 if ((gc != null) && gc.IsReferenceType)
95 // Returns whether the type parameter is "known to be a value type".
97 public virtual bool IsValueType {
99 if (HasValueTypeConstraint)
101 if (HasReferenceTypeConstraint)
104 if (ClassConstraint != null) {
105 if (!ClassConstraint.IsValueType)
108 if (ClassConstraint != TypeManager.value_type)
112 foreach (Type t in InterfaceConstraints) {
113 if (!t.IsGenericParameter)
116 GenericConstraints gc = TypeManager.GetTypeParameterConstraints (t);
117 if ((gc != null) && gc.IsValueType)
126 public enum SpecialConstraint
134 /// Tracks the constraints for a type parameter from a generic type definition.
136 public class Constraints : GenericConstraints {
138 ArrayList constraints;
142 // name is the identifier, constraints is an arraylist of
143 // Expressions (with types) or `true' for the constructor constraint.
145 public Constraints (string name, ArrayList constraints,
149 this.constraints = constraints;
153 public override string TypeParameter {
159 GenericParameterAttributes attrs;
160 TypeExpr class_constraint;
161 ArrayList iface_constraints;
162 ArrayList type_param_constraints;
164 Type class_constraint_type;
165 Type[] iface_constraint_types;
166 Type effective_base_type;
171 /// Resolve the constraints - but only resolve things into Expression's, not
172 /// into actual types.
174 public bool Resolve (IResolveContext ec)
179 iface_constraints = new ArrayList ();
180 type_param_constraints = new ArrayList ();
182 foreach (object obj in constraints) {
183 if (HasConstructorConstraint) {
184 Report.Error (401, loc,
185 "The new() constraint must be the last constraint specified");
189 if (obj is SpecialConstraint) {
190 SpecialConstraint sc = (SpecialConstraint) obj;
192 if (sc == SpecialConstraint.Constructor) {
193 if (!HasValueTypeConstraint) {
194 attrs |= GenericParameterAttributes.DefaultConstructorConstraint;
198 Report.Error (451, loc, "The `new()' constraint " +
199 "cannot be used with the `struct' constraint");
203 if ((num_constraints > 0) || HasReferenceTypeConstraint || HasValueTypeConstraint) {
204 Report.Error (449, loc, "The `class' or `struct' " +
205 "constraint must be the first constraint specified");
209 if (sc == SpecialConstraint.ReferenceType)
210 attrs |= GenericParameterAttributes.ReferenceTypeConstraint;
212 attrs |= GenericParameterAttributes.NotNullableValueTypeConstraint;
216 int errors = Report.Errors;
217 FullNamedExpression fn = ((Expression) obj).ResolveAsTypeStep (ec, false);
220 if (errors != Report.Errors)
223 NamespaceEntry.Error_NamespaceNotFound (loc, ((Expression)obj).GetSignatureForError ());
228 ConstructedType cexpr = fn as ConstructedType;
230 if (!cexpr.ResolveConstructedType (ec))
235 expr = ((Expression) obj).ResolveAsTypeTerminal (ec, false);
237 if ((expr == null) || (expr.Type == null))
240 // TODO: It's aleady done in ResolveAsBaseTerminal
241 if (!ec.GenericDeclContainer.AsAccessible (fn.Type, ec.GenericDeclContainer.ModFlags)) {
242 Report.SymbolRelatedToPreviousError (fn.Type);
243 Report.Error (703, loc,
244 "Inconsistent accessibility: constraint type `{0}' is less accessible than `{1}'",
245 fn.GetSignatureForError (), ec.GenericDeclContainer.GetSignatureForError ());
249 TypeParameterExpr texpr = expr as TypeParameterExpr;
251 type_param_constraints.Add (expr);
252 else if (expr.IsInterface)
253 iface_constraints.Add (expr);
254 else if (class_constraint != null) {
255 Report.Error (406, loc,
256 "`{0}': the class constraint for `{1}' " +
257 "must come before any other constraints.",
260 } else if (HasReferenceTypeConstraint || HasValueTypeConstraint) {
261 Report.Error (450, loc, "`{0}': cannot specify both " +
262 "a constraint class and the `class' " +
263 "or `struct' constraint", expr.GetSignatureForError ());
266 class_constraint = expr;
271 ArrayList list = new ArrayList ();
272 foreach (TypeExpr iface_constraint in iface_constraints) {
273 foreach (Type type in list) {
274 if (!type.Equals (iface_constraint.Type))
277 Report.Error (405, loc,
278 "Duplicate constraint `{0}' for type " +
279 "parameter `{1}'.", iface_constraint.GetSignatureForError (),
284 list.Add (iface_constraint.Type);
287 foreach (TypeParameterExpr expr in type_param_constraints) {
288 foreach (Type type in list) {
289 if (!type.Equals (expr.Type))
292 Report.Error (405, loc,
293 "Duplicate constraint `{0}' for type " +
294 "parameter `{1}'.", expr.GetSignatureForError (), name);
298 list.Add (expr.Type);
301 iface_constraint_types = new Type [list.Count];
302 list.CopyTo (iface_constraint_types, 0);
304 if (class_constraint != null) {
305 class_constraint_type = class_constraint.Type;
306 if (class_constraint_type == null)
309 if (class_constraint_type.IsSealed) {
310 if (class_constraint_type.IsAbstract)
312 Report.Error (717, loc, "`{0}' is not a valid constraint. Static classes cannot be used as constraints",
313 TypeManager.CSharpName (class_constraint_type));
317 Report.Error (701, loc, "`{0}' is not a valid constraint. A constraint must be an interface, " +
318 "a non-sealed class or a type parameter", TypeManager.CSharpName(class_constraint_type));
323 if ((class_constraint_type == TypeManager.array_type) ||
324 (class_constraint_type == TypeManager.delegate_type) ||
325 (class_constraint_type == TypeManager.enum_type) ||
326 (class_constraint_type == TypeManager.value_type) ||
327 (class_constraint_type == TypeManager.object_type)) {
328 Report.Error (702, loc,
329 "Bound cannot be special class `{0}'",
330 TypeManager.CSharpName (class_constraint_type));
335 if (class_constraint_type != null)
336 effective_base_type = class_constraint_type;
337 else if (HasValueTypeConstraint)
338 effective_base_type = TypeManager.value_type;
340 effective_base_type = TypeManager.object_type;
346 bool CheckTypeParameterConstraints (TypeParameter tparam, Hashtable seen)
348 seen.Add (tparam, true);
350 Constraints constraints = tparam.Constraints;
351 if (constraints == null)
354 if (constraints.HasValueTypeConstraint) {
355 Report.Error (456, loc, "Type parameter `{0}' has " +
356 "the `struct' constraint, so it cannot " +
357 "be used as a constraint for `{1}'",
362 if (constraints.type_param_constraints == null)
365 foreach (TypeParameterExpr expr in constraints.type_param_constraints) {
366 if (seen.Contains (expr.TypeParameter)) {
367 Report.Error (454, loc, "Circular constraint " +
368 "dependency involving `{0}' and `{1}'",
369 tparam.Name, expr.Name);
373 if (!CheckTypeParameterConstraints (expr.TypeParameter, seen))
381 /// Resolve the constraints into actual types.
383 public bool ResolveTypes (IResolveContext ec)
388 resolved_types = true;
390 foreach (object obj in constraints) {
391 ConstructedType cexpr = obj as ConstructedType;
395 if (!cexpr.CheckConstraints (ec))
399 foreach (TypeParameterExpr expr in type_param_constraints) {
400 Hashtable seen = new Hashtable ();
401 if (!CheckTypeParameterConstraints (expr.TypeParameter, seen))
405 for (int i = 0; i < iface_constraints.Count; ++i) {
406 TypeExpr iface_constraint = (TypeExpr) iface_constraints [i];
407 iface_constraint = iface_constraint.ResolveAsTypeTerminal (ec, false);
408 if (iface_constraint == null)
410 iface_constraints [i] = iface_constraint;
413 if (class_constraint != null) {
414 class_constraint = class_constraint.ResolveAsTypeTerminal (ec, false);
415 if (class_constraint == null)
423 /// Check whether there are no conflicts in our type parameter constraints.
425 /// This is an example:
429 /// where U : T, struct
431 public bool CheckDependencies ()
433 foreach (TypeParameterExpr expr in type_param_constraints) {
434 if (!CheckDependencies (expr.TypeParameter))
441 bool CheckDependencies (TypeParameter tparam)
443 Constraints constraints = tparam.Constraints;
444 if (constraints == null)
447 if (HasValueTypeConstraint && constraints.HasClassConstraint) {
448 Report.Error (455, loc, "Type parameter `{0}' inherits " +
449 "conflicting constraints `{1}' and `{2}'",
450 name, TypeManager.CSharpName (constraints.ClassConstraint),
455 if (HasClassConstraint && constraints.HasClassConstraint) {
456 Type t1 = ClassConstraint;
457 TypeExpr e1 = class_constraint;
458 Type t2 = constraints.ClassConstraint;
459 TypeExpr e2 = constraints.class_constraint;
461 if (!Convert.ImplicitReferenceConversionExists (e1, t2) &&
462 !Convert.ImplicitReferenceConversionExists (e2, t1)) {
463 Report.Error (455, loc,
464 "Type parameter `{0}' inherits " +
465 "conflicting constraints `{1}' and `{2}'",
466 name, TypeManager.CSharpName (t1), TypeManager.CSharpName (t2));
471 if (constraints.type_param_constraints == null)
474 foreach (TypeParameterExpr expr in constraints.type_param_constraints) {
475 if (!CheckDependencies (expr.TypeParameter))
482 public override GenericParameterAttributes Attributes {
483 get { return attrs; }
486 public override bool HasClassConstraint {
487 get { return class_constraint != null; }
490 public override Type ClassConstraint {
491 get { return class_constraint_type; }
494 public override Type[] InterfaceConstraints {
495 get { return iface_constraint_types; }
498 public override Type EffectiveBaseClass {
499 get { return effective_base_type; }
502 public bool IsSubclassOf (Type t)
504 if ((class_constraint_type != null) &&
505 class_constraint_type.IsSubclassOf (t))
508 if (iface_constraint_types == null)
511 foreach (Type iface in iface_constraint_types) {
512 if (TypeManager.IsSubclassOf (iface, t))
519 public Location Location {
526 /// This is used when we're implementing a generic interface method.
527 /// Each method type parameter in implementing method must have the same
528 /// constraints than the corresponding type parameter in the interface
529 /// method. To do that, we're called on each of the implementing method's
532 public bool CheckInterfaceMethod (GenericConstraints gc)
534 if (gc.Attributes != attrs)
537 if (HasClassConstraint != gc.HasClassConstraint)
539 if (HasClassConstraint && !TypeManager.IsEqual (gc.ClassConstraint, ClassConstraint))
542 int gc_icount = gc.InterfaceConstraints != null ?
543 gc.InterfaceConstraints.Length : 0;
544 int icount = InterfaceConstraints != null ?
545 InterfaceConstraints.Length : 0;
547 if (gc_icount != icount)
550 foreach (Type iface in gc.InterfaceConstraints) {
552 foreach (Type check in InterfaceConstraints) {
553 if (TypeManager.IsEqual (iface, check)) {
568 /// A type parameter from a generic type definition.
570 public class TypeParameter : MemberCore, IMemberContainer {
573 GenericConstraints gc;
574 Constraints constraints;
576 GenericTypeParameterBuilder type;
578 public TypeParameter (DeclSpace parent, DeclSpace decl, string name,
579 Constraints constraints, Attributes attrs, Location loc)
580 : base (parent, new MemberName (name, loc), attrs)
584 this.constraints = constraints;
588 public GenericConstraints GenericConstraints {
589 get { return gc != null ? gc : constraints; }
592 public Constraints Constraints {
593 get { return constraints; }
596 public bool HasConstructorConstraint {
597 get { return constraints != null && constraints.HasConstructorConstraint; }
600 public DeclSpace DeclSpace {
609 /// This is the first method which is called during the resolving
610 /// process; we're called immediately after creating the type parameters
611 /// with SRE (by calling `DefineGenericParameters()' on the TypeBuilder /
614 /// We're either called from TypeContainer.DefineType() or from
615 /// GenericMethod.Define() (called from Method.Define()).
617 public void Define (GenericTypeParameterBuilder type)
619 if (this.type != null)
620 throw new InvalidOperationException ();
623 TypeManager.AddTypeParameter (type, this);
627 /// This is the second method which is called during the resolving
628 /// process - in case of class type parameters, we're called from
629 /// TypeContainer.ResolveType() - after it resolved the class'es
630 /// base class and interfaces. For method type parameters, we're
631 /// called immediately after Define().
633 /// We're just resolving the constraints into expressions here, we
634 /// don't resolve them into actual types.
636 /// Note that in the special case of partial generic classes, we may be
637 /// called _before_ Define() and we may also be called multiple types.
639 public bool Resolve (DeclSpace ds)
641 if (constraints != null) {
642 if (!constraints.Resolve (ds)) {
652 /// This is the third method which is called during the resolving
653 /// process. We're called immediately after calling DefineConstraints()
654 /// on all of the current class'es type parameters.
656 /// Our job is to resolve the constraints to actual types.
658 /// Note that we may have circular dependencies on type parameters - this
659 /// is why Resolve() and ResolveType() are separate.
661 public bool ResolveType (IResolveContext ec)
663 if (constraints != null) {
664 if (!constraints.ResolveTypes (ec)) {
674 /// This is the fourth and last method which is called during the resolving
675 /// process. We're called after everything is fully resolved and actually
676 /// register the constraints with SRE and the TypeManager.
678 public bool DefineType (IResolveContext ec)
680 return DefineType (ec, null, null, false);
684 /// This is the fith and last method which is called during the resolving
685 /// process. We're called after everything is fully resolved and actually
686 /// register the constraints with SRE and the TypeManager.
688 /// The `builder', `implementing' and `is_override' arguments are only
689 /// applicable to method type parameters.
691 public bool DefineType (IResolveContext ec, MethodBuilder builder,
692 MethodInfo implementing, bool is_override)
694 if (!ResolveType (ec))
697 if (implementing != null) {
698 if (is_override && (constraints != null)) {
699 Report.Error (460, loc,
700 "`{0}': Cannot specify constraints for overrides or explicit interface implementation methods",
701 TypeManager.CSharpSignature (builder));
705 MethodBase mb = TypeManager.DropGenericMethodArguments (implementing);
707 int pos = type.GenericParameterPosition;
708 Type mparam = mb.GetGenericArguments () [pos];
709 GenericConstraints temp_gc = ReflectionConstraints.GetConstraints (mparam);
712 gc = new InflatedConstraints (temp_gc, implementing.DeclaringType);
713 else if (constraints != null)
714 gc = new InflatedConstraints (constraints, implementing.DeclaringType);
717 if (constraints != null) {
720 else if (!constraints.CheckInterfaceMethod (gc))
723 if (!is_override && (temp_gc != null))
728 Report.SymbolRelatedToPreviousError (implementing);
731 425, loc, "The constraints for type " +
732 "parameter `{0}' of method `{1}' must match " +
733 "the constraints for type parameter `{2}' " +
734 "of interface method `{3}'. Consider using " +
735 "an explicit interface implementation instead",
736 Name, TypeManager.CSharpSignature (builder),
737 TypeManager.CSharpName (mparam), TypeManager.CSharpSignature (mb));
740 } else if (DeclSpace is Iterator) {
741 TypeParameter[] tparams = DeclSpace.TypeParameters;
742 Type[] types = new Type [tparams.Length];
743 for (int i = 0; i < tparams.Length; i++)
744 types [i] = tparams [i].Type;
746 if (constraints != null)
747 gc = new InflatedConstraints (constraints, types);
749 gc = (GenericConstraints) constraints;
755 if (gc.HasClassConstraint)
756 type.SetBaseTypeConstraint (gc.ClassConstraint);
758 type.SetInterfaceConstraints (gc.InterfaceConstraints);
759 type.SetGenericParameterAttributes (gc.Attributes);
760 TypeManager.RegisterBuilder (type, gc.InterfaceConstraints);
766 /// Check whether there are no conflicts in our type parameter constraints.
768 /// This is an example:
772 /// where U : T, struct
774 public bool CheckDependencies ()
776 if (constraints != null)
777 return constraints.CheckDependencies ();
783 /// This is called for each part of a partial generic type definition.
785 /// If `new_constraints' is not null and we don't already have constraints,
786 /// they become our constraints. If we already have constraints, we must
787 /// check that they're the same.
790 public bool UpdateConstraints (IResolveContext ec, Constraints new_constraints)
793 throw new InvalidOperationException ();
795 if (new_constraints == null)
798 if (!new_constraints.Resolve (ec))
800 if (!new_constraints.ResolveTypes (ec))
803 if (constraints != null)
804 return constraints.CheckInterfaceMethod (new_constraints);
806 constraints = new_constraints;
810 public void EmitAttributes ()
812 if (OptAttributes != null)
813 OptAttributes.Emit ();
816 public override string DocCommentHeader {
818 throw new InvalidOperationException (
819 "Unexpected attempt to get doc comment from " + this.GetType () + ".");
827 public override bool Define ()
832 public override void ApplyAttributeBuilder (Attribute a,
833 CustomAttributeBuilder cb)
835 type.SetCustomAttribute (cb);
838 public override AttributeTargets AttributeTargets {
840 return (AttributeTargets) AttributeTargets.GenericParameter;
844 public override string[] ValidAttributeTargets {
846 return new string [] { "type parameter" };
854 string IMemberContainer.Name {
858 MemberCache IMemberContainer.BaseCache {
862 bool IMemberContainer.IsInterface {
866 MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
868 return FindMembers (mt, bf, null, null);
871 MemberCache IMemberContainer.MemberCache {
875 public MemberList FindMembers (MemberTypes mt, BindingFlags bf,
876 MemberFilter filter, object criteria)
878 if (constraints == null)
879 return MemberList.Empty;
881 ArrayList members = new ArrayList ();
883 if (gc.HasClassConstraint) {
884 MemberList list = TypeManager.FindMembers (
885 gc.ClassConstraint, mt, bf, filter, criteria);
887 members.AddRange (list);
890 Type[] ifaces = TypeManager.ExpandInterfaces (gc.InterfaceConstraints);
891 foreach (Type t in ifaces) {
892 MemberList list = TypeManager.FindMembers (
893 t, mt, bf, filter, criteria);
895 members.AddRange (list);
898 return new MemberList (members);
901 public bool IsSubclassOf (Type t)
906 if (constraints != null)
907 return constraints.IsSubclassOf (t);
912 public override string ToString ()
914 return "TypeParameter[" + name + "]";
917 public static string GetSignatureForError (TypeParameter[] tp)
919 if (tp == null || tp.Length == 0)
922 StringBuilder sb = new StringBuilder ("<");
923 for (int i = 0; i < tp.Length; ++i) {
926 sb.Append (tp[i].GetSignatureForError ());
929 return sb.ToString ();
932 public void InflateConstraints (Type declaring)
934 if (constraints != null)
935 gc = new InflatedConstraints (constraints, declaring);
938 protected class InflatedConstraints : GenericConstraints
940 GenericConstraints gc;
942 Type class_constraint;
943 Type[] iface_constraints;
946 public InflatedConstraints (GenericConstraints gc, Type declaring)
947 : this (gc, TypeManager.GetTypeArguments (declaring))
950 public InflatedConstraints (GenericConstraints gc, Type[] dargs)
955 ArrayList list = new ArrayList ();
956 if (gc.HasClassConstraint)
957 list.Add (inflate (gc.ClassConstraint));
958 foreach (Type iface in gc.InterfaceConstraints)
959 list.Add (inflate (iface));
961 bool has_class_constr = false;
962 if (list.Count > 0) {
963 Type first = (Type) list [0];
964 has_class_constr = !first.IsInterface && !first.IsGenericParameter;
967 if ((list.Count > 0) && has_class_constr) {
968 class_constraint = (Type) list [0];
969 iface_constraints = new Type [list.Count - 1];
970 list.CopyTo (1, iface_constraints, 0, list.Count - 1);
972 iface_constraints = new Type [list.Count];
973 list.CopyTo (iface_constraints, 0);
976 if (HasValueTypeConstraint)
977 base_type = TypeManager.value_type;
978 else if (class_constraint != null)
979 base_type = class_constraint;
981 base_type = TypeManager.object_type;
984 Type inflate (Type t)
988 if (t.IsGenericParameter)
989 return dargs [t.GenericParameterPosition];
990 if (t.IsGenericType) {
991 Type[] args = t.GetGenericArguments ();
992 Type[] inflated = new Type [args.Length];
994 for (int i = 0; i < args.Length; i++)
995 inflated [i] = inflate (args [i]);
997 t = t.GetGenericTypeDefinition ();
998 t = t.MakeGenericType (inflated);
1004 public override string TypeParameter {
1005 get { return gc.TypeParameter; }
1008 public override GenericParameterAttributes Attributes {
1009 get { return gc.Attributes; }
1012 public override Type ClassConstraint {
1013 get { return class_constraint; }
1016 public override Type EffectiveBaseClass {
1017 get { return base_type; }
1020 public override Type[] InterfaceConstraints {
1021 get { return iface_constraints; }
1027 /// A TypeExpr which already resolved to a type parameter.
1029 public class TypeParameterExpr : TypeExpr {
1030 TypeParameter type_parameter;
1032 public override string Name {
1034 return type_parameter.Name;
1038 public override string FullName {
1040 return type_parameter.Name;
1044 public TypeParameter TypeParameter {
1046 return type_parameter;
1050 public TypeParameterExpr (TypeParameter type_parameter, Location loc)
1052 this.type_parameter = type_parameter;
1056 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
1058 type = type_parameter.Type;
1063 public override bool IsInterface {
1064 get { return false; }
1067 public override bool CheckAccessLevel (DeclSpace ds)
1072 public void Error_CannotUseAsUnmanagedType (Location loc)
1074 Report.Error (-203, loc, "Can not use type parameter as unmanaged type");
1079 /// Tracks the type arguments when instantiating a generic type. We're used in
1080 /// ConstructedType.
1082 public class TypeArguments {
1083 public readonly Location Location;
1090 public TypeArguments (Location loc)
1092 args = new ArrayList ();
1093 this.Location = loc;
1096 public TypeArguments (int dimension, Location loc)
1098 this.dimension = dimension;
1099 this.Location = loc;
1102 public void Add (Expression type)
1105 throw new InvalidOperationException ();
1110 public void Add (TypeArguments new_args)
1113 throw new InvalidOperationException ();
1115 args.AddRange (new_args.args);
1119 /// We're used during the parsing process: the parser can't distinguish
1120 /// between type parameters and type arguments. Because of that, the
1121 /// parser creates a `MemberName' with `TypeArguments' for both cases and
1122 /// in case of a generic type definition, we call GetDeclarations().
1124 public TypeParameterName[] GetDeclarations ()
1126 TypeParameterName[] ret = new TypeParameterName [args.Count];
1127 for (int i = 0; i < args.Count; i++) {
1128 TypeParameterName name = args [i] as TypeParameterName;
1133 SimpleName sn = args [i] as SimpleName;
1135 ret [i] = new TypeParameterName (sn.Name, null, sn.Location);
1139 Report.Error (81, Location, "Type parameter declaration " +
1140 "must be an identifier not a type");
1147 /// We may only be used after Resolve() is called and return the fully
1150 public Type[] Arguments {
1156 public bool HasTypeArguments {
1158 return has_type_args;
1171 public bool IsUnbound {
1173 return dimension > 0;
1177 public override string ToString ()
1179 StringBuilder s = new StringBuilder ();
1182 for (int i = 0; i < count; i++){
1184 // FIXME: Use TypeManager.CSharpname once we have the type
1187 s.Append (args [i].ToString ());
1191 return s.ToString ();
1194 public string GetSignatureForError()
1196 StringBuilder sb = new StringBuilder();
1197 for (int i = 0; i < Count; ++i)
1199 Expression expr = (Expression)args [i];
1200 sb.Append(expr.GetSignatureForError());
1204 return sb.ToString();
1208 /// Resolve the type arguments.
1210 public bool Resolve (IResolveContext ec)
1212 int count = args.Count;
1215 atypes = new Type [count];
1217 for (int i = 0; i < count; i++){
1218 TypeExpr te = ((Expression) args [i]).ResolveAsTypeTerminal (ec, false);
1223 if (te is TypeParameterExpr)
1224 has_type_args = true;
1226 if (te.Type.IsSealed && te.Type.IsAbstract) {
1227 Report.Error (718, Location, "`{0}': static classes cannot be used as generic arguments",
1228 te.GetSignatureForError ());
1231 if (te.Type.IsPointer) {
1232 Report.Error (306, Location, "The type `{0}' may not be used " +
1233 "as a type argument", TypeManager.CSharpName (te.Type));
1237 if (te.Type == TypeManager.void_type) {
1238 Expression.Error_VoidInvalidInTheContext (Location);
1242 atypes [i] = te.Type;
1248 public class TypeParameterName : SimpleName
1250 Attributes attributes;
1252 public TypeParameterName (string name, Attributes attrs, Location loc)
1258 public Attributes OptAttributes {
1266 /// An instantiation of a generic type.
1268 public class ConstructedType : TypeExpr {
1270 FullNamedExpression name;
1272 Type[] gen_params, atypes;
1276 /// Instantiate the generic type `fname' with the type arguments `args'.
1278 public ConstructedType (FullNamedExpression fname, TypeArguments args, Location l)
1284 eclass = ExprClass.Type;
1285 full_name = name + "<" + args.ToString () + ">";
1288 protected ConstructedType (TypeArguments args, Location l)
1293 eclass = ExprClass.Type;
1296 protected ConstructedType (TypeParameter[] type_params, Location l)
1300 args = new TypeArguments (l);
1301 foreach (TypeParameter type_param in type_params)
1302 args.Add (new TypeParameterExpr (type_param, l));
1304 eclass = ExprClass.Type;
1308 /// This is used to construct the `this' type inside a generic type definition.
1310 public ConstructedType (Type t, TypeParameter[] type_params, Location l)
1311 : this (type_params, l)
1313 gt = t.GetGenericTypeDefinition ();
1315 this.name = new TypeExpression (gt, l);
1316 full_name = gt.FullName + "<" + args.ToString () + ">";
1320 /// Instantiate the generic type `t' with the type arguments `args'.
1321 /// Use this constructor if you already know the fully resolved
1324 public ConstructedType (Type t, TypeArguments args, Location l)
1327 gt = t.GetGenericTypeDefinition ();
1329 this.name = new TypeExpression (gt, l);
1330 full_name = gt.FullName + "<" + args.ToString () + ">";
1333 public TypeArguments TypeArguments {
1334 get { return args; }
1337 public override string GetSignatureForError ()
1339 return TypeManager.RemoveGenericArity (gt.FullName) + "<" + args.GetSignatureForError () + ">";
1342 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
1344 if (!ResolveConstructedType (ec))
1351 /// Check the constraints; we're called from ResolveAsTypeTerminal()
1352 /// after fully resolving the constructed type.
1354 public bool CheckConstraints (IResolveContext ec)
1356 return ConstraintChecker.CheckConstraints (ec, gt, gen_params, atypes, loc);
1360 /// Resolve the constructed type, but don't check the constraints.
1362 public bool ResolveConstructedType (IResolveContext ec)
1366 // If we already know the fully resolved generic type.
1368 return DoResolveType (ec);
1374 Report.Error (246, loc, "Cannot find type `{0}'<...>", Name);
1378 num_args = TypeManager.GetNumberOfTypeArguments (t);
1379 if (num_args == 0) {
1380 Report.Error (308, loc,
1381 "The non-generic type `{0}' cannot " +
1382 "be used with type arguments.",
1383 TypeManager.CSharpName (t));
1387 gt = t.GetGenericTypeDefinition ();
1388 return DoResolveType (ec);
1391 bool DoResolveType (IResolveContext ec)
1394 // Resolve the arguments.
1396 if (args.Resolve (ec) == false)
1399 gen_params = gt.GetGenericArguments ();
1400 atypes = args.Arguments;
1402 if (atypes.Length != gen_params.Length) {
1403 Report.Error (305, loc,
1404 "Using the generic type `{0}' " +
1405 "requires {1} type arguments",
1406 TypeManager.CSharpName (gt),
1407 gen_params.Length.ToString ());
1412 // Now bind the parameters.
1414 type = gt.MakeGenericType (atypes);
1418 public Expression GetSimpleName (EmitContext ec)
1423 public override bool CheckAccessLevel (DeclSpace ds)
1425 return ds.CheckAccessLevel (gt);
1428 public override bool AsAccessible (DeclSpace ds, int flags)
1430 return ds.AsAccessible (gt, flags);
1433 public override bool IsClass {
1434 get { return gt.IsClass; }
1437 public override bool IsValueType {
1438 get { return gt.IsValueType; }
1441 public override bool IsInterface {
1442 get { return gt.IsInterface; }
1445 public override bool IsSealed {
1446 get { return gt.IsSealed; }
1449 public override bool Equals (object obj)
1451 ConstructedType cobj = obj as ConstructedType;
1455 if ((type == null) || (cobj.type == null))
1458 return type == cobj.type;
1461 public override int GetHashCode ()
1463 return base.GetHashCode ();
1466 public override string Name {
1472 public override string FullName {
1479 public abstract class ConstraintChecker
1481 protected readonly Type[] gen_params;
1482 protected readonly Type[] atypes;
1483 protected readonly Location loc;
1485 protected ConstraintChecker (Type[] gen_params, Type[] atypes, Location loc)
1487 this.gen_params = gen_params;
1488 this.atypes = atypes;
1493 /// Check the constraints; we're called from ResolveAsTypeTerminal()
1494 /// after fully resolving the constructed type.
1496 public bool CheckConstraints (IResolveContext ec)
1498 for (int i = 0; i < gen_params.Length; i++) {
1499 if (!CheckConstraints (ec, i))
1506 protected bool CheckConstraints (IResolveContext ec, int index)
1508 Type atype = atypes [index];
1509 Type ptype = gen_params [index];
1514 Expression aexpr = new EmptyExpression (atype);
1516 GenericConstraints gc = TypeManager.GetTypeParameterConstraints (ptype);
1520 bool is_class, is_struct;
1521 if (atype.IsGenericParameter) {
1522 GenericConstraints agc = TypeManager.GetTypeParameterConstraints (atype);
1524 if (agc is Constraints)
1525 ((Constraints) agc).Resolve (ec);
1526 is_class = agc.HasReferenceTypeConstraint;
1527 is_struct = agc.HasValueTypeConstraint;
1529 is_class = is_struct = false;
1534 if (!atype.IsGenericType)
1536 is_class = atype.IsClass || atype.IsInterface;
1537 is_struct = atype.IsValueType && !TypeManager.IsNullableType (atype);
1541 // First, check the `class' and `struct' constraints.
1543 if (gc.HasReferenceTypeConstraint && !is_class) {
1544 Report.Error (452, loc, "The type `{0}' must be " +
1545 "a reference type in order to use it " +
1546 "as type parameter `{1}' in the " +
1547 "generic type or method `{2}'.",
1548 TypeManager.CSharpName (atype),
1549 TypeManager.CSharpName (ptype),
1550 GetSignatureForError ());
1552 } else if (gc.HasValueTypeConstraint && !is_struct) {
1553 Report.Error (453, loc, "The type `{0}' must be a " +
1554 "non-nullable value type in order to use it " +
1555 "as type parameter `{1}' in the " +
1556 "generic type or method `{2}'.",
1557 TypeManager.CSharpName (atype),
1558 TypeManager.CSharpName (ptype),
1559 GetSignatureForError ());
1564 // The class constraint comes next.
1566 if (gc.HasClassConstraint) {
1567 if (!CheckConstraint (ec, ptype, aexpr, gc.ClassConstraint))
1572 // Now, check the interface constraints.
1574 if (gc.InterfaceConstraints != null) {
1575 foreach (Type it in gc.InterfaceConstraints) {
1576 if (!CheckConstraint (ec, ptype, aexpr, it))
1582 // Finally, check the constructor constraint.
1585 if (!gc.HasConstructorConstraint)
1588 if (TypeManager.IsBuiltinType (atype) || atype.IsValueType)
1591 if (HasDefaultConstructor (ec.DeclContainer.TypeBuilder, atype))
1594 Report_SymbolRelatedToPreviousError ();
1595 Report.SymbolRelatedToPreviousError (atype);
1596 Report.Error (310, loc, "The type `{0}' must have a public " +
1597 "parameterless constructor in order to use it " +
1598 "as parameter `{1}' in the generic type or " +
1600 TypeManager.CSharpName (atype),
1601 TypeManager.CSharpName (ptype),
1602 GetSignatureForError ());
1606 protected bool CheckConstraint (IResolveContext ec, Type ptype, Expression expr,
1609 if (TypeManager.HasGenericArguments (ctype)) {
1610 Type[] types = TypeManager.GetTypeArguments (ctype);
1612 TypeArguments new_args = new TypeArguments (loc);
1614 for (int i = 0; i < types.Length; i++) {
1617 if (t.IsGenericParameter) {
1618 int pos = t.GenericParameterPosition;
1621 new_args.Add (new TypeExpression (t, loc));
1624 TypeExpr ct = new ConstructedType (ctype, new_args, loc);
1625 if (ct.ResolveAsTypeStep (ec, false) == null)
1628 } else if (ctype.IsGenericParameter) {
1629 int pos = ctype.GenericParameterPosition;
1630 ctype = atypes [pos];
1633 if (Convert.ImplicitStandardConversionExists (expr, ctype))
1636 Error_TypeMustBeConvertible (expr.Type, ctype, ptype);
1640 bool HasDefaultConstructor (Type containerType, Type atype)
1642 if (atype.IsAbstract)
1646 atype = TypeManager.DropGenericTypeArguments (atype);
1647 if (atype is TypeBuilder) {
1648 TypeContainer tc = TypeManager.LookupTypeContainer (atype);
1649 if (tc.InstanceConstructors == null) {
1650 atype = atype.BaseType;
1654 foreach (Constructor c in tc.InstanceConstructors) {
1655 if ((c.ModFlags & Modifiers.PUBLIC) == 0)
1657 if ((c.Parameters.FixedParameters != null) &&
1658 (c.Parameters.FixedParameters.Length != 0))
1660 if (c.Parameters.HasArglist || c.Parameters.HasParams)
1667 TypeParameter tparam = TypeManager.LookupTypeParameter (atype);
1669 return tparam.HasConstructorConstraint;
1671 MemberList list = TypeManager.FindMembers (
1672 atype, MemberTypes.Constructor,
1673 BindingFlags.Public | BindingFlags.Instance |
1674 BindingFlags.DeclaredOnly, null, null);
1676 if (atype.IsAbstract || (list == null))
1679 foreach (MethodBase mb in list) {
1680 ParameterData pd = TypeManager.GetParameterData (mb);
1681 if ((pd.Count == 0) && mb.IsPublic && !mb.IsStatic)
1688 protected abstract string GetSignatureForError ();
1689 protected abstract void Report_SymbolRelatedToPreviousError ();
1691 void Error_TypeMustBeConvertible (Type atype, Type gc, Type ptype)
1693 Report_SymbolRelatedToPreviousError ();
1694 Report.SymbolRelatedToPreviousError (atype);
1695 Report.Error (309, loc,
1696 "The type `{0}' must be convertible to `{1}' in order to " +
1697 "use it as parameter `{2}' in the generic type or method `{3}'",
1698 TypeManager.CSharpName (atype), TypeManager.CSharpName (gc),
1699 TypeManager.CSharpName (ptype), GetSignatureForError ());
1702 public static bool CheckConstraints (EmitContext ec, MethodBase definition,
1703 MethodBase instantiated, Location loc)
1705 MethodConstraintChecker checker = new MethodConstraintChecker (
1706 definition, definition.GetGenericArguments (),
1707 instantiated.GetGenericArguments (), loc);
1709 return checker.CheckConstraints (ec);
1712 public static bool CheckConstraints (IResolveContext ec, Type gt, Type[] gen_params,
1713 Type[] atypes, Location loc)
1715 TypeConstraintChecker checker = new TypeConstraintChecker (
1716 gt, gen_params, atypes, loc);
1718 return checker.CheckConstraints (ec);
1721 protected class MethodConstraintChecker : ConstraintChecker
1723 MethodBase definition;
1725 public MethodConstraintChecker (MethodBase definition, Type[] gen_params,
1726 Type[] atypes, Location loc)
1727 : base (gen_params, atypes, loc)
1729 this.definition = definition;
1732 protected override string GetSignatureForError ()
1734 return TypeManager.CSharpSignature (definition);
1737 protected override void Report_SymbolRelatedToPreviousError ()
1739 Report.SymbolRelatedToPreviousError (definition);
1743 protected class TypeConstraintChecker : ConstraintChecker
1747 public TypeConstraintChecker (Type gt, Type[] gen_params, Type[] atypes,
1749 : base (gen_params, atypes, loc)
1754 protected override string GetSignatureForError ()
1756 return TypeManager.CSharpName (gt);
1759 protected override void Report_SymbolRelatedToPreviousError ()
1761 Report.SymbolRelatedToPreviousError (gt);
1767 /// A generic method definition.
1769 public class GenericMethod : DeclSpace
1771 Expression return_type;
1772 Parameters parameters;
1774 public GenericMethod (NamespaceEntry ns, DeclSpace parent, MemberName name,
1775 Expression return_type, Parameters parameters)
1776 : base (ns, parent, name, null)
1778 this.return_type = return_type;
1779 this.parameters = parameters;
1782 public override TypeBuilder DefineType ()
1784 throw new Exception ();
1787 public override bool Define ()
1789 for (int i = 0; i < TypeParameters.Length; i++)
1790 if (!TypeParameters [i].Resolve (this))
1797 /// Define and resolve the type parameters.
1798 /// We're called from Method.Define().
1800 public bool Define (MethodBuilder mb, ToplevelBlock block)
1802 TypeParameterName[] names = MemberName.TypeArguments.GetDeclarations ();
1803 string[] snames = new string [names.Length];
1804 for (int i = 0; i < names.Length; i++) {
1805 string type_argument_name = names[i].Name;
1806 Parameter p = parameters.GetParameterByName (type_argument_name);
1808 Error_ParameterNameCollision (p.Location, type_argument_name, "method parameter");
1811 if (block != null) {
1812 LocalInfo li = (LocalInfo)block.Variables[type_argument_name];
1814 Error_ParameterNameCollision (li.Location, type_argument_name, "local variable");
1818 snames[i] = type_argument_name;
1821 GenericTypeParameterBuilder[] gen_params = mb.DefineGenericParameters (snames);
1822 for (int i = 0; i < TypeParameters.Length; i++)
1823 TypeParameters [i].Define (gen_params [i]);
1828 for (int i = 0; i < TypeParameters.Length; i++) {
1829 if (!TypeParameters [i].ResolveType (this))
1836 static void Error_ParameterNameCollision (Location loc, string name, string collisionWith)
1838 Report.Error (412, loc, "The type parameter name `{0}' is the same as `{1}'",
1839 name, collisionWith);
1843 /// We're called from MethodData.Define() after creating the MethodBuilder.
1845 public bool DefineType (EmitContext ec, MethodBuilder mb,
1846 MethodInfo implementing, bool is_override)
1848 for (int i = 0; i < TypeParameters.Length; i++)
1849 if (!TypeParameters [i].DefineType (
1850 ec, mb, implementing, is_override))
1854 foreach (Parameter p in parameters.FixedParameters){
1855 if (!p.Resolve (ec))
1858 if ((return_type != null) && (return_type.ResolveAsTypeTerminal (ec, false) == null))
1864 public void EmitAttributes ()
1866 for (int i = 0; i < TypeParameters.Length; i++)
1867 TypeParameters [i].EmitAttributes ();
1869 if (OptAttributes != null)
1870 OptAttributes.Emit ();
1873 public override bool DefineMembers ()
1878 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
1879 MemberFilter filter, object criteria)
1881 throw new Exception ();
1884 public override MemberCache MemberCache {
1890 public override AttributeTargets AttributeTargets {
1892 return AttributeTargets.Method | AttributeTargets.ReturnValue;
1896 public override string DocCommentHeader {
1897 get { return "M:"; }
1901 public class DefaultValueExpression : Expression
1905 public DefaultValueExpression (Expression expr, Location loc)
1911 public override Expression DoResolve (EmitContext ec)
1913 TypeExpr texpr = expr.ResolveAsTypeTerminal (ec, false);
1919 if (type.IsGenericParameter)
1921 GenericConstraints constraints = TypeManager.GetTypeParameterConstraints(type);
1922 if (constraints != null && constraints.IsReferenceType)
1923 return new NullDefault(loc, this);
1927 Constant c = New.Constantify(type);
1931 if (!TypeManager.IsValueType(type))
1932 return new NullDefault(loc, this);
1934 eclass = ExprClass.Variable;
1938 public override void Emit (EmitContext ec)
1940 LocalTemporary temp_storage = new LocalTemporary(type);
1942 temp_storage.AddressOf(ec, AddressOp.LoadStore);
1943 ec.ig.Emit(OpCodes.Initobj, type);
1944 temp_storage.Emit(ec);
1948 public class NullableType : TypeExpr
1950 Expression underlying;
1952 public NullableType (Expression underlying, Location l)
1954 this.underlying = underlying;
1957 eclass = ExprClass.Type;
1960 public NullableType (Type type, Location loc)
1961 : this (new TypeExpression (type, loc), loc)
1964 public override string Name {
1965 get { return underlying.ToString () + "?"; }
1968 public override string FullName {
1969 get { return underlying.ToString () + "?"; }
1972 protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
1974 TypeArguments args = new TypeArguments (loc);
1975 args.Add (underlying);
1977 ConstructedType ctype = new ConstructedType (TypeManager.generic_nullable_type, args, loc);
1978 return ctype.ResolveAsTypeTerminal (ec, false);
1982 public partial class TypeManager
1985 // A list of core types that the compiler requires or uses
1987 static public Type activator_type;
1988 static public Type generic_ilist_type;
1989 static public Type generic_icollection_type;
1990 static public Type generic_ienumerator_type;
1991 static public Type generic_ienumerable_type;
1992 static public Type generic_nullable_type;
1995 // These methods are called by code generated by the compiler
1997 static public MethodInfo activator_create_instance;
1999 static void InitGenericCoreTypes ()
2001 activator_type = CoreLookupType ("System", "Activator");
2003 generic_ilist_type = CoreLookupType (
2004 "System.Collections.Generic", "IList", 1);
2005 generic_icollection_type = CoreLookupType (
2006 "System.Collections.Generic", "ICollection", 1);
2007 generic_ienumerator_type = CoreLookupType (
2008 "System.Collections.Generic", "IEnumerator", 1);
2009 generic_ienumerable_type = CoreLookupType (
2010 "System.Collections.Generic", "IEnumerable", 1);
2011 generic_nullable_type = CoreLookupType (
2012 "System", "Nullable", 1);
2015 static void InitGenericCodeHelpers ()
2018 Type [] type_arg = { type_type };
2019 activator_create_instance = GetMethod (
2020 activator_type, "CreateInstance", type_arg);
2023 static Type CoreLookupType (string ns, string name, int arity)
2025 return CoreLookupType (ns, MemberName.MakeName (name, arity));
2028 public static TypeContainer LookupGenericTypeContainer (Type t)
2030 t = DropGenericTypeArguments (t);
2031 return LookupTypeContainer (t);
2034 public static GenericConstraints GetTypeParameterConstraints (Type t)
2036 if (!t.IsGenericParameter)
2037 throw new InvalidOperationException ();
2039 TypeParameter tparam = LookupTypeParameter (t);
2041 return tparam.GenericConstraints;
2043 return ReflectionConstraints.GetConstraints (t);
2047 /// Check whether `a' and `b' may become equal generic types.
2048 /// The algorithm to do that is a little bit complicated.
2050 public static bool MayBecomeEqualGenericTypes (Type a, Type b, Type[] class_infered,
2051 Type[] method_infered)
2053 if (a.IsGenericParameter) {
2055 // If a is an array of a's type, they may never
2059 b = b.GetElementType ();
2065 // If b is a generic parameter or an actual type,
2066 // they may become equal:
2068 // class X<T,U> : I<T>, I<U>
2069 // class X<T> : I<T>, I<float>
2071 if (b.IsGenericParameter || !b.IsGenericType) {
2072 int pos = a.GenericParameterPosition;
2073 Type[] args = a.DeclaringMethod != null ? method_infered : class_infered;
2074 if (args [pos] == null) {
2079 return args [pos] == a;
2083 // We're now comparing a type parameter with a
2084 // generic instance. They may become equal unless
2085 // the type parameter appears anywhere in the
2086 // generic instance:
2088 // class X<T,U> : I<T>, I<X<U>>
2089 // -> error because you could instanciate it as
2092 // class X<T> : I<T>, I<X<T>> -> ok
2095 Type[] bargs = GetTypeArguments (b);
2096 for (int i = 0; i < bargs.Length; i++) {
2097 if (a.Equals (bargs [i]))
2104 if (b.IsGenericParameter)
2105 return MayBecomeEqualGenericTypes (b, a, class_infered, method_infered);
2108 // At this point, neither a nor b are a type parameter.
2110 // If one of them is a generic instance, let
2111 // MayBecomeEqualGenericInstances() compare them (if the
2112 // other one is not a generic instance, they can never
2116 if (a.IsGenericType || b.IsGenericType)
2117 return MayBecomeEqualGenericInstances (a, b, class_infered, method_infered);
2120 // If both of them are arrays.
2123 if (a.IsArray && b.IsArray) {
2124 if (a.GetArrayRank () != b.GetArrayRank ())
2127 a = a.GetElementType ();
2128 b = b.GetElementType ();
2130 return MayBecomeEqualGenericTypes (a, b, class_infered, method_infered);
2134 // Ok, two ordinary types.
2137 return a.Equals (b);
2141 // Checks whether two generic instances may become equal for some
2142 // particular instantiation (26.3.1).
2144 public static bool MayBecomeEqualGenericInstances (Type a, Type b,
2145 Type[] class_infered,
2146 Type[] method_infered)
2148 if (!a.IsGenericType || !b.IsGenericType)
2150 if (a.GetGenericTypeDefinition () != b.GetGenericTypeDefinition ())
2153 return MayBecomeEqualGenericInstances (
2154 GetTypeArguments (a), GetTypeArguments (b), class_infered, method_infered);
2157 public static bool MayBecomeEqualGenericInstances (Type[] aargs, Type[] bargs,
2158 Type[] class_infered,
2159 Type[] method_infered)
2161 if (aargs.Length != bargs.Length)
2164 for (int i = 0; i < aargs.Length; i++) {
2165 if (!MayBecomeEqualGenericTypes (aargs [i], bargs [i], class_infered, method_infered))
2176 static bool InferType (Type pt, Type at, Type[] infered)
2178 if (pt.IsGenericParameter) {
2179 if (pt.DeclaringMethod == null)
2182 int pos = pt.GenericParameterPosition;
2184 if (infered [pos] == null) {
2189 if (infered [pos] != at)
2195 if (!pt.ContainsGenericParameters) {
2196 if (at.ContainsGenericParameters)
2197 return InferType (at, pt, infered);
2204 if (at.GetArrayRank () != pt.GetArrayRank ())
2207 return InferType (pt.GetElementType (), at.GetElementType (), infered);
2210 if (!pt.IsGenericType)
2213 Type gt = pt.GetGenericTypeDefinition ();
2214 if ((gt != generic_ilist_type) && (gt != generic_icollection_type) &&
2215 (gt != generic_ienumerable_type))
2218 Type[] args = GetTypeArguments (pt);
2219 return InferType (args [0], at.GetElementType (), infered);
2224 (pt.GetArrayRank () != at.GetArrayRank ()))
2227 return InferType (pt.GetElementType (), at.GetElementType (), infered);
2230 if (pt.IsByRef && at.IsByRef)
2231 return InferType (pt.GetElementType (), at.GetElementType (), infered);
2232 ArrayList list = new ArrayList ();
2233 if (at.IsGenericType)
2235 for (Type bt = at.BaseType; bt != null; bt = bt.BaseType)
2238 list.AddRange (TypeManager.GetInterfaces (at));
2240 bool found_one = false;
2242 foreach (Type type in list) {
2243 if (!type.IsGenericType)
2246 Type[] infered_types = new Type [infered.Length];
2248 if (!InferGenericInstance (pt, type, infered_types))
2251 for (int i = 0; i < infered_types.Length; i++) {
2252 if (infered [i] == null) {
2253 infered [i] = infered_types [i];
2257 if (infered [i] != infered_types [i])
2267 static bool InferGenericInstance (Type pt, Type at, Type[] infered_types)
2269 Type[] at_args = at.GetGenericArguments ();
2270 Type[] pt_args = pt.GetGenericArguments ();
2272 if (at_args.Length != pt_args.Length)
2275 for (int i = 0; i < at_args.Length; i++) {
2276 if (!InferType (pt_args [i], at_args [i], infered_types))
2280 for (int i = 0; i < infered_types.Length; i++) {
2281 if (infered_types [i] == null)
2289 /// Type inference. Try to infer the type arguments from the params method
2290 /// `method', which is invoked with the arguments `arguments'. This is used
2291 /// when resolving an Invocation or a DelegateInvocation and the user
2292 /// did not explicitly specify type arguments.
2294 public static bool InferParamsTypeArguments (EmitContext ec, ArrayList arguments,
2295 ref MethodBase method)
2297 if (!TypeManager.IsGenericMethod (method))
2300 // if there are no arguments, there's no way to infer the type-arguments
2301 if (arguments == null || arguments.Count == 0)
2304 ParameterData pd = TypeManager.GetParameterData (method);
2305 int pd_count = pd.Count;
2306 int arg_count = arguments.Count;
2311 if (pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS)
2314 if (pd_count - 1 > arg_count)
2317 Type[] method_args = method.GetGenericArguments ();
2318 Type[] infered_types = new Type [method_args.Length];
2321 // If we have come this far, the case which
2322 // remains is when the number of parameters is
2323 // less than or equal to the argument count.
2325 for (int i = 0; i < pd_count - 1; ++i) {
2326 Argument a = (Argument) arguments [i];
2328 if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr))
2331 Type pt = pd.ParameterType (i);
2334 if (!InferType (pt, at, infered_types))
2338 Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
2340 for (int i = pd_count - 1; i < arg_count; i++) {
2341 Argument a = (Argument) arguments [i];
2343 if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr))
2346 if (!InferType (element_type, a.Type, infered_types))
2350 for (int i = 0; i < infered_types.Length; i++)
2351 if (infered_types [i] == null)
2354 method = ((MethodInfo)method).MakeGenericMethod (infered_types);
2358 static bool InferTypeArguments (Type[] param_types, Type[] arg_types,
2359 Type[] infered_types)
2361 if (infered_types == null)
2364 for (int i = 0; i < arg_types.Length; i++) {
2365 if (arg_types [i] == null)
2368 if (!InferType (param_types [i], arg_types [i], infered_types))
2372 for (int i = 0; i < infered_types.Length; i++)
2373 if (infered_types [i] == null)
2380 /// Type inference. Try to infer the type arguments from `method',
2381 /// which is invoked with the arguments `arguments'. This is used
2382 /// when resolving an Invocation or a DelegateInvocation and the user
2383 /// did not explicitly specify type arguments.
2385 public static bool InferTypeArguments (ArrayList arguments,
2386 ref MethodBase method)
2388 if (!TypeManager.IsGenericMethod (method))
2392 if (arguments != null)
2393 arg_count = arguments.Count;
2397 ParameterData pd = TypeManager.GetParameterData (method);
2398 if (arg_count != pd.Count)
2401 Type[] method_args = method.GetGenericArguments ();
2403 bool is_open = false;
2404 for (int i = 0; i < method_args.Length; i++) {
2405 if (method_args [i].IsGenericParameter) {
2411 // If none of the method parameters mention a generic parameter, we can't infer the generic parameters
2413 return !TypeManager.IsGenericMethodDefinition (method);
2415 Type[] infered_types = new Type [method_args.Length];
2417 Type[] param_types = new Type [pd.Count];
2418 Type[] arg_types = new Type [pd.Count];
2420 for (int i = 0; i < arg_count; i++) {
2421 param_types [i] = pd.ParameterType (i);
2423 Argument a = (Argument) arguments [i];
2424 if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr) ||
2425 (a.Expr is AnonymousMethod))
2428 arg_types [i] = a.Type;
2431 if (!InferTypeArguments (param_types, arg_types, infered_types))
2434 method = ((MethodInfo)method).MakeGenericMethod (infered_types);
2441 public static bool InferTypeArguments (ParameterData apd,
2442 ref MethodBase method)
2444 if (!TypeManager.IsGenericMethod (method))
2447 ParameterData pd = TypeManager.GetParameterData (method);
2448 if (apd.Count != pd.Count)
2451 Type[] method_args = method.GetGenericArguments ();
2452 Type[] infered_types = new Type [method_args.Length];
2454 Type[] param_types = new Type [pd.Count];
2455 Type[] arg_types = new Type [pd.Count];
2457 for (int i = 0; i < apd.Count; i++) {
2458 param_types [i] = pd.ParameterType (i);
2459 arg_types [i] = apd.ParameterType (i);
2462 if (!InferTypeArguments (param_types, arg_types, infered_types))
2465 method = ((MethodInfo)method).MakeGenericMethod (infered_types);
2469 public static bool IsNullableType (Type t)
2471 return generic_nullable_type == DropGenericTypeArguments (t);
2474 public static bool IsNullableTypeOf (Type t, Type nullable)
2476 if (!IsNullableType (t))
2479 return GetTypeArguments (t) [0] == nullable;
2482 public static bool IsNullableValueType (Type t)
2484 if (!IsNullableType (t))
2487 return GetTypeArguments (t) [0].IsValueType;
2491 public abstract class Nullable
2493 public sealed class NullableInfo
2495 public readonly Type Type;
2496 public readonly Type UnderlyingType;
2497 public readonly MethodInfo HasValue;
2498 public readonly MethodInfo Value;
2499 public readonly ConstructorInfo Constructor;
2501 public NullableInfo (Type type)
2504 UnderlyingType = TypeManager.GetTypeArguments (type) [0];
2506 PropertyInfo has_value_pi = TypeManager.GetProperty (type, "HasValue");
2507 PropertyInfo value_pi = TypeManager.GetProperty (type, "Value");
2509 HasValue = has_value_pi.GetGetMethod (false);
2510 Value = value_pi.GetGetMethod (false);
2511 Constructor = type.GetConstructor (new Type[] { UnderlyingType });
2515 public class Unwrap : Expression, IMemoryLocation, IAssignMethod
2520 LocalTemporary temp;
2523 protected Unwrap (Expression expr)
2526 this.loc = expr.Location;
2529 public static Unwrap Create (Expression expr, EmitContext ec)
2531 return new Unwrap (expr).Resolve (ec) as Unwrap;
2534 public override Expression DoResolve (EmitContext ec)
2536 expr = expr.Resolve (ec);
2540 temp = new LocalTemporary (expr.Type);
2542 info = new NullableInfo (expr.Type);
2543 type = info.UnderlyingType;
2544 eclass = expr.eclass;
2548 public override void Emit (EmitContext ec)
2550 AddressOf (ec, AddressOp.LoadStore);
2551 ec.ig.EmitCall (OpCodes.Call, info.Value, null);
2554 public void EmitCheck (EmitContext ec)
2556 AddressOf (ec, AddressOp.LoadStore);
2557 ec.ig.EmitCall (OpCodes.Call, info.HasValue, null);
2560 public void Store (EmitContext ec)
2565 void create_temp (EmitContext ec)
2567 if ((temp != null) && !has_temp) {
2574 public void AddressOf (EmitContext ec, AddressOp mode)
2578 temp.AddressOf (ec, AddressOp.LoadStore);
2580 ((IMemoryLocation) expr).AddressOf (ec, AddressOp.LoadStore);
2583 public void Emit (EmitContext ec, bool leave_copy)
2596 public void EmitAssign (EmitContext ec, Expression source,
2597 bool leave_copy, bool prepare_for_load)
2599 InternalWrap wrap = new InternalWrap (source, info, loc);
2600 ((IAssignMethod) expr).EmitAssign (ec, wrap, leave_copy, false);
2603 protected class InternalWrap : Expression
2605 public Expression expr;
2606 public NullableInfo info;
2608 public InternalWrap (Expression expr, NullableInfo info, Location loc)
2615 eclass = ExprClass.Value;
2618 public override Expression DoResolve (EmitContext ec)
2623 public override void Emit (EmitContext ec)
2626 ec.ig.Emit (OpCodes.Newobj, info.Constructor);
2631 public class Wrap : Expression
2636 protected Wrap (Expression expr)
2639 this.loc = expr.Location;
2642 public static Wrap Create (Expression expr, EmitContext ec)
2644 return new Wrap (expr).Resolve (ec) as Wrap;
2647 public override Expression DoResolve (EmitContext ec)
2649 expr = expr.Resolve (ec);
2653 TypeExpr target_type = new NullableType (expr.Type, loc);
2654 target_type = target_type.ResolveAsTypeTerminal (ec, false);
2655 if (target_type == null)
2658 type = target_type.Type;
2659 info = new NullableInfo (type);
2660 eclass = ExprClass.Value;
2664 public override void Emit (EmitContext ec)
2667 ec.ig.Emit (OpCodes.Newobj, info.Constructor);
2671 public class NullableLiteral : NullLiteral, IMemoryLocation {
2672 public NullableLiteral (Type target_type, Location loc)
2675 this.type = target_type;
2677 eclass = ExprClass.Value;
2680 public override Expression DoResolve (EmitContext ec)
2685 public override void Emit (EmitContext ec)
2687 LocalTemporary value_target = new LocalTemporary (type);
2689 value_target.AddressOf (ec, AddressOp.Store);
2690 ec.ig.Emit (OpCodes.Initobj, type);
2691 value_target.Emit (ec);
2694 public void AddressOf (EmitContext ec, AddressOp Mode)
2696 LocalTemporary value_target = new LocalTemporary (type);
2698 value_target.AddressOf (ec, AddressOp.Store);
2699 ec.ig.Emit (OpCodes.Initobj, type);
2700 ((IMemoryLocation) value_target).AddressOf (ec, Mode);
2704 public abstract class Lifted : Expression, IMemoryLocation
2706 Expression expr, underlying, wrap, null_value;
2709 protected Lifted (Expression expr, Location loc)
2715 public override Expression DoResolve (EmitContext ec)
2717 expr = expr.Resolve (ec);
2721 unwrap = Unwrap.Create (expr, ec);
2725 underlying = ResolveUnderlying (unwrap, ec);
2726 if (underlying == null)
2729 wrap = Wrap.Create (underlying, ec);
2733 null_value = new NullableLiteral (wrap.Type, loc).Resolve (ec);
2734 if (null_value == null)
2738 eclass = ExprClass.Value;
2742 protected abstract Expression ResolveUnderlying (Expression unwrap, EmitContext ec);
2744 public override void Emit (EmitContext ec)
2746 ILGenerator ig = ec.ig;
2747 Label is_null_label = ig.DefineLabel ();
2748 Label end_label = ig.DefineLabel ();
2750 unwrap.EmitCheck (ec);
2751 ig.Emit (OpCodes.Brfalse, is_null_label);
2754 ig.Emit (OpCodes.Br, end_label);
2756 ig.MarkLabel (is_null_label);
2757 null_value.Emit (ec);
2759 ig.MarkLabel (end_label);
2762 public void AddressOf (EmitContext ec, AddressOp mode)
2764 unwrap.AddressOf (ec, mode);
2768 public class LiftedConversion : Lifted
2770 public readonly bool IsUser;
2771 public readonly bool IsExplicit;
2772 public readonly Type TargetType;
2774 public LiftedConversion (Expression expr, Type target_type, bool is_user,
2775 bool is_explicit, Location loc)
2778 this.IsUser = is_user;
2779 this.IsExplicit = is_explicit;
2780 this.TargetType = target_type;
2783 protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
2785 Type type = TypeManager.GetTypeArguments (TargetType) [0];
2788 return Convert.UserDefinedConversion (ec, unwrap, type, loc, IsExplicit);
2791 return Convert.ExplicitConversion (ec, unwrap, type, loc);
2793 return Convert.ImplicitConversion (ec, unwrap, type, loc);
2798 public class LiftedUnaryOperator : Lifted
2800 public readonly Unary.Operator Oper;
2802 public LiftedUnaryOperator (Unary.Operator op, Expression expr, Location loc)
2808 protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
2810 return new Unary (Oper, unwrap, loc);
2814 public class LiftedConditional : Lifted
2816 Expression true_expr, false_expr;
2818 public LiftedConditional (Expression expr, Expression true_expr, Expression false_expr,
2822 this.true_expr = true_expr;
2823 this.false_expr = false_expr;
2826 protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
2828 return new Conditional (unwrap, true_expr, false_expr);
2832 public class LiftedBinaryOperator : Expression
2834 public readonly Binary.Operator Oper;
2836 Expression left, right, original_left, original_right;
2837 Expression underlying, null_value, bool_wrap;
2838 Unwrap left_unwrap, right_unwrap;
2839 bool is_equality, is_comparision, is_boolean;
2841 public LiftedBinaryOperator (Binary.Operator op, Expression left, Expression right,
2845 this.left = original_left = left;
2846 this.right = original_right = right;
2850 public override Expression DoResolve (EmitContext ec)
2852 if (TypeManager.IsNullableType (left.Type)) {
2853 left = left_unwrap = Unwrap.Create (left, ec);
2858 if (TypeManager.IsNullableType (right.Type)) {
2859 right = right_unwrap = Unwrap.Create (right, ec);
2864 if ((Oper == Binary.Operator.LogicalAnd) ||
2865 (Oper == Binary.Operator.LogicalOr)) {
2866 Binary.Error_OperatorCannotBeApplied (
2867 loc, Binary.OperName (Oper),
2868 original_left.GetSignatureForError (),
2869 original_right.GetSignatureForError ());
2873 if (((Oper == Binary.Operator.BitwiseAnd) || (Oper == Binary.Operator.BitwiseOr)) &&
2874 ((left.Type == TypeManager.bool_type) && (right.Type == TypeManager.bool_type))) {
2875 Expression empty = new EmptyExpression (TypeManager.bool_type);
2876 bool_wrap = Wrap.Create (empty, ec);
2877 null_value = new NullableLiteral (bool_wrap.Type, loc).Resolve (ec);
2879 type = bool_wrap.Type;
2881 } else if ((Oper == Binary.Operator.Equality) || (Oper == Binary.Operator.Inequality)) {
2882 if (!(left is NullLiteral) && !(right is NullLiteral)) {
2883 underlying = new Binary (Oper, left, right).Resolve (ec);
2884 if (underlying == null)
2888 type = TypeManager.bool_type;
2890 } else if ((Oper == Binary.Operator.LessThan) ||
2891 (Oper == Binary.Operator.GreaterThan) ||
2892 (Oper == Binary.Operator.LessThanOrEqual) ||
2893 (Oper == Binary.Operator.GreaterThanOrEqual)) {
2894 underlying = new Binary (Oper, left, right).Resolve (ec);
2895 if (underlying == null)
2898 type = TypeManager.bool_type;
2899 is_comparision = true;
2901 underlying = new Binary (Oper, left, right).Resolve (ec);
2902 if (underlying == null)
2905 underlying = Wrap.Create (underlying, ec);
2906 if (underlying == null)
2909 type = underlying.Type;
2910 null_value = new NullableLiteral (type, loc).Resolve (ec);
2913 eclass = ExprClass.Value;
2917 void EmitBoolean (EmitContext ec)
2919 ILGenerator ig = ec.ig;
2921 Label left_is_null_label = ig.DefineLabel ();
2922 Label right_is_null_label = ig.DefineLabel ();
2923 Label is_null_label = ig.DefineLabel ();
2924 Label wrap_label = ig.DefineLabel ();
2925 Label end_label = ig.DefineLabel ();
2927 if (left_unwrap != null) {
2928 left_unwrap.EmitCheck (ec);
2929 ig.Emit (OpCodes.Brfalse, left_is_null_label);
2933 ig.Emit (OpCodes.Dup);
2934 if ((Oper == Binary.Operator.BitwiseOr) || (Oper == Binary.Operator.LogicalOr))
2935 ig.Emit (OpCodes.Brtrue, wrap_label);
2937 ig.Emit (OpCodes.Brfalse, wrap_label);
2939 if (right_unwrap != null) {
2940 right_unwrap.EmitCheck (ec);
2941 ig.Emit (OpCodes.Brfalse, right_is_null_label);
2944 if ((Oper == Binary.Operator.LogicalAnd) || (Oper == Binary.Operator.LogicalOr))
2945 ig.Emit (OpCodes.Pop);
2948 if (Oper == Binary.Operator.BitwiseOr)
2949 ig.Emit (OpCodes.Or);
2950 else if (Oper == Binary.Operator.BitwiseAnd)
2951 ig.Emit (OpCodes.And);
2952 ig.Emit (OpCodes.Br, wrap_label);
2954 ig.MarkLabel (left_is_null_label);
2955 if (right_unwrap != null) {
2956 right_unwrap.EmitCheck (ec);
2957 ig.Emit (OpCodes.Brfalse, is_null_label);
2961 ig.Emit (OpCodes.Dup);
2962 if ((Oper == Binary.Operator.BitwiseOr) || (Oper == Binary.Operator.LogicalOr))
2963 ig.Emit (OpCodes.Brtrue, wrap_label);
2965 ig.Emit (OpCodes.Brfalse, wrap_label);
2967 ig.MarkLabel (right_is_null_label);
2968 ig.Emit (OpCodes.Pop);
2969 ig.MarkLabel (is_null_label);
2970 null_value.Emit (ec);
2971 ig.Emit (OpCodes.Br, end_label);
2973 ig.MarkLabel (wrap_label);
2974 ig.Emit (OpCodes.Nop);
2975 bool_wrap.Emit (ec);
2976 ig.Emit (OpCodes.Nop);
2978 ig.MarkLabel (end_label);
2981 void EmitEquality (EmitContext ec)
2983 ILGenerator ig = ec.ig;
2985 // Given 'X? x;' for any value type X: 'x != null' is the same as 'x.HasValue'
2986 if (left is NullLiteral) {
2987 if (right_unwrap == null)
2988 throw new InternalErrorException ();
2989 right_unwrap.EmitCheck (ec);
2990 if (Oper == Binary.Operator.Equality) {
2991 ig.Emit (OpCodes.Ldc_I4_0);
2992 ig.Emit (OpCodes.Ceq);
2997 if (right is NullLiteral) {
2998 if (left_unwrap == null)
2999 throw new InternalErrorException ();
3000 left_unwrap.EmitCheck (ec);
3001 if (Oper == Binary.Operator.Equality) {
3002 ig.Emit (OpCodes.Ldc_I4_0);
3003 ig.Emit (OpCodes.Ceq);
3008 Label both_have_value_label = ig.DefineLabel ();
3009 Label end_label = ig.DefineLabel ();
3011 if (left_unwrap != null && right_unwrap != null) {
3012 Label dissimilar_label = ig.DefineLabel ();
3014 left_unwrap.EmitCheck (ec);
3015 ig.Emit (OpCodes.Dup);
3016 right_unwrap.EmitCheck (ec);
3017 ig.Emit (OpCodes.Bne_Un, dissimilar_label);
3019 ig.Emit (OpCodes.Brtrue, both_have_value_label);
3022 if (Oper == Binary.Operator.Equality)
3023 ig.Emit (OpCodes.Ldc_I4_1);
3025 ig.Emit (OpCodes.Ldc_I4_0);
3026 ig.Emit (OpCodes.Br, end_label);
3028 ig.MarkLabel (dissimilar_label);
3029 ig.Emit (OpCodes.Pop);
3030 } else if (left_unwrap != null) {
3031 left_unwrap.EmitCheck (ec);
3032 ig.Emit (OpCodes.Brtrue, both_have_value_label);
3033 } else if (right_unwrap != null) {
3034 right_unwrap.EmitCheck (ec);
3035 ig.Emit (OpCodes.Brtrue, both_have_value_label);
3037 throw new InternalErrorException ("shouldn't get here");
3040 // one is null while the other isn't
3041 if (Oper == Binary.Operator.Equality)
3042 ig.Emit (OpCodes.Ldc_I4_0);
3044 ig.Emit (OpCodes.Ldc_I4_1);
3045 ig.Emit (OpCodes.Br, end_label);
3047 ig.MarkLabel (both_have_value_label);
3048 underlying.Emit (ec);
3050 ig.MarkLabel (end_label);
3053 void EmitComparision (EmitContext ec)
3055 ILGenerator ig = ec.ig;
3057 Label is_null_label = ig.DefineLabel ();
3058 Label end_label = ig.DefineLabel ();
3060 if (left_unwrap != null) {
3061 left_unwrap.EmitCheck (ec);
3062 ig.Emit (OpCodes.Brfalse, is_null_label);
3065 if (right_unwrap != null) {
3066 right_unwrap.EmitCheck (ec);
3067 ig.Emit (OpCodes.Brfalse, is_null_label);
3070 underlying.Emit (ec);
3071 ig.Emit (OpCodes.Br, end_label);
3073 ig.MarkLabel (is_null_label);
3074 ig.Emit (OpCodes.Ldc_I4_0);
3076 ig.MarkLabel (end_label);
3079 public override void Emit (EmitContext ec)
3081 if (left_unwrap != null)
3082 left_unwrap.Store (ec);
3083 if (right_unwrap != null)
3084 right_unwrap.Store (ec);
3089 } else if (is_equality) {
3092 } else if (is_comparision) {
3093 EmitComparision (ec);
3097 ILGenerator ig = ec.ig;
3099 Label is_null_label = ig.DefineLabel ();
3100 Label end_label = ig.DefineLabel ();
3102 if (left_unwrap != null) {
3103 left_unwrap.EmitCheck (ec);
3104 ig.Emit (OpCodes.Brfalse, is_null_label);
3107 if (right_unwrap != null) {
3108 right_unwrap.EmitCheck (ec);
3109 ig.Emit (OpCodes.Brfalse, is_null_label);
3112 underlying.Emit (ec);
3113 ig.Emit (OpCodes.Br, end_label);
3115 ig.MarkLabel (is_null_label);
3116 null_value.Emit (ec);
3118 ig.MarkLabel (end_label);
3122 public class OperatorTrueOrFalse : Expression
3124 public readonly bool IsTrue;
3129 public OperatorTrueOrFalse (Expression expr, bool is_true, Location loc)
3131 this.IsTrue = is_true;
3136 public override Expression DoResolve (EmitContext ec)
3138 unwrap = Unwrap.Create (expr, ec);
3142 if (unwrap.Type != TypeManager.bool_type)
3145 type = TypeManager.bool_type;
3146 eclass = ExprClass.Value;
3150 public override void Emit (EmitContext ec)
3152 ILGenerator ig = ec.ig;
3154 Label is_null_label = ig.DefineLabel ();
3155 Label end_label = ig.DefineLabel ();
3157 unwrap.EmitCheck (ec);
3158 ig.Emit (OpCodes.Brfalse, is_null_label);
3162 ig.Emit (OpCodes.Ldc_I4_0);
3163 ig.Emit (OpCodes.Ceq);
3165 ig.Emit (OpCodes.Br, end_label);
3167 ig.MarkLabel (is_null_label);
3168 ig.Emit (OpCodes.Ldc_I4_0);
3170 ig.MarkLabel (end_label);
3174 public class NullCoalescingOperator : Expression
3176 Expression left, right;
3180 public NullCoalescingOperator (Expression left, Expression right, Location loc)
3186 eclass = ExprClass.Value;
3189 public override Expression DoResolve (EmitContext ec)
3194 left = left.Resolve (ec);
3198 right = right.Resolve (ec);
3202 Type ltype = left.Type, rtype = right.Type;
3204 if (!TypeManager.IsNullableType (ltype) && ltype.IsValueType) {
3205 Binary.Error_OperatorCannotBeApplied (loc, "??", ltype, rtype);
3209 if (TypeManager.IsNullableType (ltype)) {
3210 NullableInfo info = new NullableInfo (ltype);
3212 unwrap = Unwrap.Create (left, ec);
3216 expr = Convert.ImplicitConversion (ec, right, info.UnderlyingType, loc);
3224 expr = Convert.ImplicitConversion (ec, right, ltype, loc);
3230 if (unwrap != null) {
3231 expr = Convert.ImplicitConversion (ec, unwrap, rtype, loc);
3240 Binary.Error_OperatorCannotBeApplied (loc, "??", ltype, rtype);
3244 public override void Emit (EmitContext ec)
3246 ILGenerator ig = ec.ig;
3248 Label is_null_label = ig.DefineLabel ();
3249 Label end_label = ig.DefineLabel ();
3251 if (unwrap != null) {
3252 unwrap.EmitCheck (ec);
3253 ig.Emit (OpCodes.Brfalse, is_null_label);
3256 ig.Emit (OpCodes.Br, end_label);
3258 ig.MarkLabel (is_null_label);
3261 ig.MarkLabel (end_label);
3264 ig.Emit (OpCodes.Dup);
3265 ig.Emit (OpCodes.Brtrue, end_label);
3267 ig.MarkLabel (is_null_label);
3269 ig.Emit (OpCodes.Pop);
3272 ig.MarkLabel (end_label);
3277 public class LiftedUnaryMutator : ExpressionStatement
3279 public readonly UnaryMutator.Mode Mode;
3280 Expression expr, null_value;
3281 UnaryMutator underlying;
3284 public LiftedUnaryMutator (UnaryMutator.Mode mode, Expression expr, Location loc)
3290 eclass = ExprClass.Value;
3293 public override Expression DoResolve (EmitContext ec)
3295 expr = expr.Resolve (ec);
3299 unwrap = Unwrap.Create (expr, ec);
3303 underlying = (UnaryMutator) new UnaryMutator (Mode, unwrap, loc).Resolve (ec);
3304 if (underlying == null)
3307 null_value = new NullableLiteral (expr.Type, loc).Resolve (ec);
3308 if (null_value == null)
3315 void DoEmit (EmitContext ec, bool is_expr)
3317 ILGenerator ig = ec.ig;
3318 Label is_null_label = ig.DefineLabel ();
3319 Label end_label = ig.DefineLabel ();
3321 unwrap.EmitCheck (ec);
3322 ig.Emit (OpCodes.Brfalse, is_null_label);
3325 underlying.Emit (ec);
3327 underlying.EmitStatement (ec);
3328 ig.Emit (OpCodes.Br, end_label);
3330 ig.MarkLabel (is_null_label);
3332 null_value.Emit (ec);
3334 ig.MarkLabel (end_label);
3337 public override void Emit (EmitContext ec)
3342 public override void EmitStatement (EmitContext ec)