+ type.SetCustomAttribute (cb);
+ }
+
+ public override AttributeTargets AttributeTargets {
+ get {
+ return (AttributeTargets) AttributeTargets.GenericParameter;
+ }
+ }
+
+ public override string[] ValidAttributeTargets {
+ get {
+ return new string [] { "type parameter" };
+ }
+ }
+
+ //
+ // IMemberContainer
+ //
+
+ string IMemberContainer.Name {
+ get { return Name; }
+ }
+
+ MemberCache IMemberContainer.BaseCache {
+ get {
+ if (gc == null)
+ return null;
+
+ if (gc.EffectiveBaseClass.BaseType == null)
+ return null;
+
+ return TypeManager.LookupMemberCache (gc.EffectiveBaseClass.BaseType);
+ }
+ }
+
+ bool IMemberContainer.IsInterface {
+ get { return false; }
+ }
+
+ MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
+ {
+ return FindMembers (mt, bf, null, null);
+ }
+
+ public MemberCache MemberCache {
+ get {
+ if (member_cache != null)
+ return member_cache;
+
+ if (gc == null)
+ return null;
+
+ Type[] ifaces = TypeManager.ExpandInterfaces (gc.InterfaceConstraints);
+ member_cache = new MemberCache (this, gc.EffectiveBaseClass, ifaces);
+
+ return member_cache;
+ }
+ }
+
+ public MemberList FindMembers (MemberTypes mt, BindingFlags bf,
+ MemberFilter filter, object criteria)
+ {
+ if (gc == null)
+ return MemberList.Empty;
+
+ ArrayList members = new ArrayList ();
+
+ if (gc.HasClassConstraint) {
+ MemberList list = TypeManager.FindMembers (
+ gc.ClassConstraint, mt, bf, filter, criteria);
+
+ members.AddRange (list);
+ }
+
+ Type[] ifaces = TypeManager.ExpandInterfaces (gc.InterfaceConstraints);
+ foreach (Type t in ifaces) {
+ MemberList list = TypeManager.FindMembers (
+ t, mt, bf, filter, criteria);
+
+ members.AddRange (list);
+ }
+
+ return new MemberList (members);
+ }
+
+ public bool IsSubclassOf (Type t)
+ {
+ if (type.Equals (t))
+ return true;
+
+ if (constraints != null)
+ return constraints.IsSubclassOf (t);
+
+ return false;
+ }
+
+ public override string ToString ()
+ {
+ return "TypeParameter[" + name + "]";
+ }
+
+ public static string GetSignatureForError (TypeParameter[] tp)
+ {
+ if (tp == null || tp.Length == 0)
+ return "";
+
+ StringBuilder sb = new StringBuilder ("<");
+ for (int i = 0; i < tp.Length; ++i) {
+ if (i > 0)
+ sb.Append (",");
+ sb.Append (tp[i].GetSignatureForError ());
+ }
+ sb.Append ('>');
+ return sb.ToString ();
+ }
+
+ public void InflateConstraints (Type declaring)
+ {
+ if (constraints != null)
+ gc = new InflatedConstraints (constraints, declaring);
+ }
+
+ public override bool IsClsComplianceRequired ()
+ {
+ return false;
+ }
+
+ protected class InflatedConstraints : GenericConstraints
+ {
+ GenericConstraints gc;
+ Type base_type;
+ Type class_constraint;
+ Type[] iface_constraints;
+ Type[] dargs;
+
+ public InflatedConstraints (GenericConstraints gc, Type declaring)
+ : this (gc, TypeManager.GetTypeArguments (declaring))
+ { }
+
+ public InflatedConstraints (GenericConstraints gc, Type[] dargs)
+ {
+ this.gc = gc;
+ this.dargs = dargs;
+
+ ArrayList list = new ArrayList ();
+ if (gc.HasClassConstraint)
+ list.Add (inflate (gc.ClassConstraint));
+ foreach (Type iface in gc.InterfaceConstraints)
+ list.Add (inflate (iface));
+
+ bool has_class_constr = false;
+ if (list.Count > 0) {
+ Type first = (Type) list [0];
+ has_class_constr = !first.IsGenericParameter && !first.IsInterface;
+ }
+
+ if ((list.Count > 0) && has_class_constr) {
+ class_constraint = (Type) list [0];
+ iface_constraints = new Type [list.Count - 1];
+ list.CopyTo (1, iface_constraints, 0, list.Count - 1);
+ } else {
+ iface_constraints = new Type [list.Count];
+ list.CopyTo (iface_constraints, 0);
+ }
+
+ if (HasValueTypeConstraint)
+ base_type = TypeManager.value_type;
+ else if (class_constraint != null)
+ base_type = class_constraint;
+ else
+ base_type = TypeManager.object_type;
+ }
+
+ Type inflate (Type t)
+ {
+ if (t == null)
+ return null;
+ if (t.IsGenericParameter)
+ return dargs [t.GenericParameterPosition];
+ if (t.IsGenericType) {
+ Type[] args = t.GetGenericArguments ();
+ Type[] inflated = new Type [args.Length];
+
+ for (int i = 0; i < args.Length; i++)
+ inflated [i] = inflate (args [i]);
+
+ t = t.GetGenericTypeDefinition ();
+ t = t.MakeGenericType (inflated);
+ }
+
+ return t;
+ }
+
+ public override string TypeParameter {
+ get { return gc.TypeParameter; }
+ }
+
+ public override GenericParameterAttributes Attributes {
+ get { return gc.Attributes; }
+ }
+
+ public override Type ClassConstraint {
+ get { return class_constraint; }
+ }
+
+ public override Type EffectiveBaseClass {
+ get { return base_type; }
+ }
+
+ public override Type[] InterfaceConstraints {
+ get { return iface_constraints; }
+ }
+ }
+ }
+
+ /// <summary>
+ /// A TypeExpr which already resolved to a type parameter.
+ /// </summary>
+ public class TypeParameterExpr : TypeExpr {
+ TypeParameter type_parameter;
+
+ public override string Name {
+ get {
+ return type_parameter.Name;
+ }
+ }
+
+ public override string FullName {
+ get {
+ return type_parameter.Name;
+ }
+ }
+
+ public TypeParameter TypeParameter {
+ get {
+ return type_parameter;
+ }
+ }
+
+ public TypeParameterExpr (TypeParameter type_parameter, Location loc)
+ {
+ this.type_parameter = type_parameter;
+ this.loc = loc;
+ }
+
+ protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
+ {
+ type = type_parameter.Type;
+
+ return this;
+ }
+
+ public override bool IsInterface {
+ get { return false; }
+ }
+
+ public override bool CheckAccessLevel (DeclSpace ds)
+ {
+ return true;
+ }
+
+ public void Error_CannotUseAsUnmanagedType (Location loc)
+ {
+ Report.Error (-203, loc, "Can not use type parameter as unmanaged type");
+ }
+ }
+
+ /// <summary>
+ /// Tracks the type arguments when instantiating a generic type. We're used in
+ /// ConstructedType.
+ /// </summary>
+ public class TypeArguments {
+ public readonly Location Location;
+ ArrayList args;
+ Type[] atypes;
+ int dimension;
+ bool has_type_args;
+ bool created;
+
+ public TypeArguments (Location loc)
+ {
+ args = new ArrayList ();
+ this.Location = loc;
+ }
+
+ public TypeArguments (Location loc, params Expression[] types)
+ {
+ this.Location = loc;
+ this.args = new ArrayList (types);
+ }
+
+ public TypeArguments (int dimension, Location loc)
+ {
+ this.dimension = dimension;
+ this.Location = loc;
+ }
+
+ public void Add (Expression type)
+ {
+ if (created)
+ throw new InvalidOperationException ();
+
+ args.Add (type);
+ }
+
+ public void Add (TypeArguments new_args)
+ {
+ if (created)
+ throw new InvalidOperationException ();
+
+ args.AddRange (new_args.args);
+ }
+
+ /// <summary>
+ /// We're used during the parsing process: the parser can't distinguish
+ /// between type parameters and type arguments. Because of that, the
+ /// parser creates a `MemberName' with `TypeArguments' for both cases and
+ /// in case of a generic type definition, we call GetDeclarations().
+ /// </summary>
+ public TypeParameterName[] GetDeclarations ()
+ {
+ TypeParameterName[] ret = new TypeParameterName [args.Count];
+ for (int i = 0; i < args.Count; i++) {
+ TypeParameterName name = args [i] as TypeParameterName;
+ if (name != null) {
+ ret [i] = name;
+ continue;
+ }
+ SimpleName sn = args [i] as SimpleName;
+ if (sn != null) {
+ ret [i] = new TypeParameterName (sn.Name, null, sn.Location);
+ continue;
+ }
+
+ Report.Error (81, Location, "Type parameter declaration " +
+ "must be an identifier not a type");
+ return null;
+ }
+ return ret;
+ }
+
+ /// <summary>
+ /// We may only be used after Resolve() is called and return the fully
+ /// resolved types.
+ /// </summary>
+ public Type[] Arguments {
+ get {
+ return atypes;
+ }
+ }
+
+ public bool HasTypeArguments {
+ get {
+ return has_type_args;
+ }
+ }
+
+ public int Count {
+ get {
+ if (dimension > 0)
+ return dimension;
+ else
+ return args.Count;
+ }
+ }
+
+ public bool IsUnbound {
+ get {
+ return dimension > 0;
+ }
+ }
+
+ public override string ToString ()
+ {
+ StringBuilder s = new StringBuilder ();
+
+ int count = Count;
+ for (int i = 0; i < count; i++){
+ //
+ // FIXME: Use TypeManager.CSharpname once we have the type
+ //
+ if (args != null)
+ s.Append (args [i].ToString ());
+ if (i+1 < count)
+ s.Append (",");
+ }
+ return s.ToString ();
+ }
+
+ public string GetSignatureForError()
+ {
+ StringBuilder sb = new StringBuilder();
+ for (int i = 0; i < Count; ++i)
+ {
+ Expression expr = (Expression)args [i];
+ sb.Append(expr.GetSignatureForError());
+ if (i + 1 < Count)
+ sb.Append(',');
+ }
+ return sb.ToString();
+ }
+
+ /// <summary>
+ /// Resolve the type arguments.
+ /// </summary>
+ public bool Resolve (IResolveContext ec)
+ {
+ int count = args.Count;
+ bool ok = true;
+
+ atypes = new Type [count];
+
+ for (int i = 0; i < count; i++){
+ TypeExpr te = ((Expression) args [i]).ResolveAsTypeTerminal (ec, false);
+ if (te == null) {
+ ok = false;
+ continue;
+ }
+
+ atypes[i] = te.Type;
+ if (te.Type.IsGenericParameter) {
+ if (te is TypeParameterExpr)
+ has_type_args = true;
+ continue;
+ }
+
+ if (te.Type.IsSealed && te.Type.IsAbstract) {
+ Report.Error (718, Location, "`{0}': static classes cannot be used as generic arguments",
+ te.GetSignatureForError ());
+ return false;
+ }
+
+ if (te.Type.IsPointer) {
+ Report.Error (306, Location, "The type `{0}' may not be used " +
+ "as a type argument", TypeManager.CSharpName (te.Type));
+ return false;
+ }
+
+ if (te.Type == TypeManager.void_type) {
+ Expression.Error_VoidInvalidInTheContext (Location);
+ return false;
+ }
+ }
+ return ok;
+ }
+
+ public TypeArguments Clone ()
+ {
+ TypeArguments copy = new TypeArguments (Location);
+ foreach (Expression ta in args)
+ copy.args.Add (ta);
+
+ return copy;
+ }
+ }
+
+ public class TypeParameterName : SimpleName
+ {
+ Attributes attributes;
+
+ public TypeParameterName (string name, Attributes attrs, Location loc)
+ : base (name, loc)
+ {
+ attributes = attrs;
+ }
+
+ public Attributes OptAttributes {
+ get {
+ return attributes;
+ }
+ }
+ }
+
+ /// <summary>
+ /// An instantiation of a generic type.
+ /// </summary>
+ public class ConstructedType : TypeExpr {
+ string full_name;
+ FullNamedExpression name;
+ TypeArguments args;
+ Type[] gen_params, atypes;
+ Type gt;
+
+ /// <summary>
+ /// Instantiate the generic type `fname' with the type arguments `args'.
+ /// </summary>
+ public ConstructedType (FullNamedExpression fname, TypeArguments args, Location l)
+ {
+ loc = l;
+ this.name = fname;
+ this.args = args;
+
+ eclass = ExprClass.Type;
+ full_name = name + "<" + args.ToString () + ">";
+ }
+
+ protected ConstructedType (TypeArguments args, Location l)
+ {
+ loc = l;
+ this.args = args;
+
+ eclass = ExprClass.Type;
+ }
+
+ protected ConstructedType (TypeParameter[] type_params, Location l)
+ {
+ loc = l;
+
+ args = new TypeArguments (l);
+ foreach (TypeParameter type_param in type_params)
+ args.Add (new TypeParameterExpr (type_param, l));
+
+ eclass = ExprClass.Type;
+ }
+
+ /// <summary>
+ /// This is used to construct the `this' type inside a generic type definition.
+ /// </summary>
+ public ConstructedType (Type t, TypeParameter[] type_params, Location l)
+ : this (type_params, l)
+ {
+ gt = t.GetGenericTypeDefinition ();
+
+ this.name = new TypeExpression (gt, l);
+ full_name = gt.FullName + "<" + args.ToString () + ">";
+ }
+
+ /// <summary>
+ /// Instantiate the generic type `t' with the type arguments `args'.
+ /// Use this constructor if you already know the fully resolved
+ /// generic type.
+ /// </summary>
+ public ConstructedType (Type t, TypeArguments args, Location l)
+ : this (args, l)
+ {
+ gt = t.GetGenericTypeDefinition ();
+
+ this.name = new TypeExpression (gt, l);
+ full_name = gt.FullName + "<" + args.ToString () + ">";
+ }
+
+ public TypeArguments TypeArguments {
+ get { return args; }
+ }
+
+ public override string GetSignatureForError ()
+ {
+ return TypeManager.RemoveGenericArity (gt.FullName) + "<" + args.GetSignatureForError () + ">";
+ }
+
+ protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
+ {
+ if (!ResolveConstructedType (ec))
+ return null;
+
+ return this;
+ }
+
+ /// <summary>
+ /// Check the constraints; we're called from ResolveAsTypeTerminal()
+ /// after fully resolving the constructed type.
+ /// </summary>
+ public bool CheckConstraints (IResolveContext ec)
+ {
+ return ConstraintChecker.CheckConstraints (ec, gt, gen_params, atypes, loc);
+ }
+
+ /// <summary>
+ /// Resolve the constructed type, but don't check the constraints.
+ /// </summary>
+ public bool ResolveConstructedType (IResolveContext ec)
+ {
+ if (type != null)
+ return true;
+ // If we already know the fully resolved generic type.
+ if (gt != null)
+ return DoResolveType (ec);
+
+ int num_args;
+ Type t = name.Type;
+
+ if (t == null) {
+ Report.Error (246, loc, "Cannot find type `{0}'<...>", Name);
+ return false;
+ }
+
+ num_args = TypeManager.GetNumberOfTypeArguments (t);
+ if (num_args == 0) {
+ Report.Error (308, loc,
+ "The non-generic type `{0}' cannot " +
+ "be used with type arguments.",
+ TypeManager.CSharpName (t));
+ return false;
+ }
+
+ gt = t.GetGenericTypeDefinition ();
+ return DoResolveType (ec);
+ }
+
+ bool DoResolveType (IResolveContext ec)
+ {
+ //
+ // Resolve the arguments.
+ //
+ if (args.Resolve (ec) == false)
+ return false;
+
+ gen_params = gt.GetGenericArguments ();
+ atypes = args.Arguments;
+
+ if (atypes.Length != gen_params.Length) {
+ Report.Error (305, loc,
+ "Using the generic type `{0}' " +
+ "requires {1} type arguments",
+ TypeManager.CSharpName (gt),
+ gen_params.Length.ToString ());
+ return false;
+ }
+
+ //
+ // Now bind the parameters.
+ //
+ type = gt.MakeGenericType (atypes);
+ return true;
+ }
+
+ public Expression GetSimpleName (EmitContext ec)
+ {
+ return this;
+ }
+
+ public override bool CheckAccessLevel (DeclSpace ds)
+ {
+ return ds.CheckAccessLevel (gt);
+ }
+
+ public override bool AsAccessible (DeclSpace ds, int flags)
+ {
+ foreach (Type t in atypes) {
+ if (!ds.AsAccessible (t, flags))
+ return false;
+ }
+
+ return ds.AsAccessible (gt, flags);
+ }
+
+ public override bool IsClass {
+ get { return gt.IsClass; }
+ }
+
+ public override bool IsValueType {
+ get { return gt.IsValueType; }
+ }
+
+ public override bool IsInterface {
+ get { return gt.IsInterface; }
+ }
+
+ public override bool IsSealed {
+ get { return gt.IsSealed; }
+ }
+
+ public override bool Equals (object obj)
+ {
+ ConstructedType cobj = obj as ConstructedType;
+ if (cobj == null)
+ return false;
+
+ if ((type == null) || (cobj.type == null))
+ return false;
+
+ return type == cobj.type;
+ }
+
+ public override int GetHashCode ()
+ {
+ return base.GetHashCode ();
+ }
+
+ public override string Name {
+ get {
+ return full_name;
+ }
+ }
+
+ public override string FullName {
+ get {
+ return full_name;
+ }
+ }
+ }
+
+ public abstract class ConstraintChecker
+ {
+ protected readonly Type[] gen_params;
+ protected readonly Type[] atypes;
+ protected readonly Location loc;
+
+ protected ConstraintChecker (Type[] gen_params, Type[] atypes, Location loc)
+ {
+ this.gen_params = gen_params;
+ this.atypes = atypes;
+ this.loc = loc;
+ }
+
+ /// <summary>
+ /// Check the constraints; we're called from ResolveAsTypeTerminal()
+ /// after fully resolving the constructed type.
+ /// </summary>
+ public bool CheckConstraints (IResolveContext ec)
+ {
+ for (int i = 0; i < gen_params.Length; i++) {
+ if (!CheckConstraints (ec, i))
+ return false;
+ }
+
+ return true;
+ }
+
+ protected bool CheckConstraints (IResolveContext ec, int index)
+ {
+ Type atype = atypes [index];
+ Type ptype = gen_params [index];
+
+ if (atype == ptype)
+ return true;
+
+ Expression aexpr = new EmptyExpression (atype);
+
+ GenericConstraints gc = TypeManager.GetTypeParameterConstraints (ptype);
+ if (gc == null)
+ return true;
+
+ bool is_class, is_struct;
+ if (atype.IsGenericParameter) {
+ GenericConstraints agc = TypeManager.GetTypeParameterConstraints (atype);
+ if (agc != null) {
+ if (agc is Constraints)
+ ((Constraints) agc).Resolve (ec);
+ is_class = agc.IsReferenceType;
+ is_struct = agc.IsValueType;
+ } else {
+ is_class = is_struct = false;
+ }
+ } else {
+#if MS_COMPATIBLE
+ is_class = false;
+ if (!atype.IsGenericType)
+#endif
+ is_class = atype.IsClass || atype.IsInterface;
+ is_struct = atype.IsValueType && !TypeManager.IsNullableType (atype);
+ }
+
+ //
+ // First, check the `class' and `struct' constraints.
+ //
+ if (gc.HasReferenceTypeConstraint && !is_class) {
+ Report.Error (452, loc, "The type `{0}' must be " +
+ "a reference type in order to use it " +
+ "as type parameter `{1}' in the " +
+ "generic type or method `{2}'.",
+ TypeManager.CSharpName (atype),
+ TypeManager.CSharpName (ptype),
+ GetSignatureForError ());
+ return false;
+ } else if (gc.HasValueTypeConstraint && !is_struct) {
+ Report.Error (453, loc, "The type `{0}' must be a " +
+ "non-nullable value type in order to use it " +
+ "as type parameter `{1}' in the " +
+ "generic type or method `{2}'.",
+ TypeManager.CSharpName (atype),
+ TypeManager.CSharpName (ptype),
+ GetSignatureForError ());
+ return false;
+ }
+
+ //
+ // The class constraint comes next.
+ //
+ if (gc.HasClassConstraint) {
+ if (!CheckConstraint (ec, ptype, aexpr, gc.ClassConstraint))
+ return false;
+ }
+
+ //
+ // Now, check the interface constraints.
+ //
+ if (gc.InterfaceConstraints != null) {
+ foreach (Type it in gc.InterfaceConstraints) {
+ if (!CheckConstraint (ec, ptype, aexpr, it))
+ return false;
+ }
+ }
+
+ //
+ // Finally, check the constructor constraint.
+ //
+
+ if (!gc.HasConstructorConstraint)
+ return true;
+
+ if (TypeManager.IsBuiltinType (atype) || atype.IsValueType)
+ return true;
+
+ if (HasDefaultConstructor (atype))
+ return true;
+
+ Report_SymbolRelatedToPreviousError ();
+ Report.SymbolRelatedToPreviousError (atype);
+ Report.Error (310, loc, "The type `{0}' must have a public " +
+ "parameterless constructor in order to use it " +
+ "as parameter `{1}' in the generic type or " +
+ "method `{2}'",
+ TypeManager.CSharpName (atype),
+ TypeManager.CSharpName (ptype),
+ GetSignatureForError ());
+ return false;
+ }
+
+ protected bool CheckConstraint (IResolveContext ec, Type ptype, Expression expr,
+ Type ctype)
+ {
+ if (TypeManager.HasGenericArguments (ctype)) {
+ Type[] types = TypeManager.GetTypeArguments (ctype);
+
+ TypeArguments new_args = new TypeArguments (loc);
+
+ for (int i = 0; i < types.Length; i++) {
+ Type t = types [i];
+
+ if (t.IsGenericParameter) {
+ int pos = t.GenericParameterPosition;
+ t = atypes [pos];
+ }
+ new_args.Add (new TypeExpression (t, loc));
+ }
+
+ TypeExpr ct = new ConstructedType (ctype, new_args, loc);
+ if (ct.ResolveAsTypeStep (ec, false) == null)
+ return false;
+ ctype = ct.Type;
+ } else if (ctype.IsGenericParameter) {
+ int pos = ctype.GenericParameterPosition;
+ ctype = atypes [pos];
+ }
+
+ if (Convert.ImplicitStandardConversionExists (expr, ctype))
+ return true;
+
+ Error_TypeMustBeConvertible (expr.Type, ctype, ptype);
+ return false;
+ }
+
+ bool HasDefaultConstructor (Type atype)
+ {
+ if (atype.IsAbstract)
+ return false;
+
+ again:
+ atype = TypeManager.DropGenericTypeArguments (atype);
+ if (atype is TypeBuilder) {
+ TypeContainer tc = TypeManager.LookupTypeContainer (atype);
+ if (tc.InstanceConstructors == null) {
+ atype = atype.BaseType;
+ goto again;
+ }
+
+ foreach (Constructor c in tc.InstanceConstructors) {
+ if ((c.ModFlags & Modifiers.PUBLIC) == 0)
+ continue;
+ if ((c.Parameters.FixedParameters != null) &&
+ (c.Parameters.FixedParameters.Length != 0))
+ continue;
+ if (c.Parameters.HasArglist || c.Parameters.HasParams)
+ continue;
+
+ return true;
+ }
+ }
+
+ TypeParameter tparam = TypeManager.LookupTypeParameter (atype);
+ if (tparam != null) {
+ if (tparam.GenericConstraints == null)
+ return false;
+ else
+ return tparam.GenericConstraints.HasConstructorConstraint;
+ }
+
+ MemberList list = TypeManager.FindMembers (
+ atype, MemberTypes.Constructor,
+ BindingFlags.Public | BindingFlags.Instance |
+ BindingFlags.DeclaredOnly, null, null);
+
+ if (atype.IsAbstract || (list == null))
+ return false;
+
+ foreach (MethodBase mb in list) {
+ ParameterData pd = TypeManager.GetParameterData (mb);
+ if ((pd.Count == 0) && mb.IsPublic && !mb.IsStatic)
+ return true;
+ }
+
+ return false;
+ }
+
+ protected abstract string GetSignatureForError ();
+ protected abstract void Report_SymbolRelatedToPreviousError ();
+
+ void Error_TypeMustBeConvertible (Type atype, Type gc, Type ptype)
+ {
+ Report_SymbolRelatedToPreviousError ();
+ Report.SymbolRelatedToPreviousError (atype);
+ Report.Error (309, loc,
+ "The type `{0}' must be convertible to `{1}' in order to " +
+ "use it as parameter `{2}' in the generic type or method `{3}'",
+ TypeManager.CSharpName (atype), TypeManager.CSharpName (gc),
+ TypeManager.CSharpName (ptype), GetSignatureForError ());
+ }
+
+ public static bool CheckConstraints (EmitContext ec, MethodBase definition,
+ MethodBase instantiated, Location loc)
+ {
+ MethodConstraintChecker checker = new MethodConstraintChecker (
+ definition, definition.GetGenericArguments (),
+ instantiated.GetGenericArguments (), loc);
+
+ return checker.CheckConstraints (ec);
+ }
+
+ public static bool CheckConstraints (IResolveContext ec, Type gt, Type[] gen_params,
+ Type[] atypes, Location loc)
+ {
+ TypeConstraintChecker checker = new TypeConstraintChecker (
+ gt, gen_params, atypes, loc);
+
+ return checker.CheckConstraints (ec);
+ }
+
+ protected class MethodConstraintChecker : ConstraintChecker
+ {
+ MethodBase definition;
+
+ public MethodConstraintChecker (MethodBase definition, Type[] gen_params,
+ Type[] atypes, Location loc)
+ : base (gen_params, atypes, loc)
+ {
+ this.definition = definition;
+ }
+
+ protected override string GetSignatureForError ()
+ {
+ return TypeManager.CSharpSignature (definition);
+ }
+
+ protected override void Report_SymbolRelatedToPreviousError ()
+ {
+ Report.SymbolRelatedToPreviousError (definition);
+ }
+ }
+
+ protected class TypeConstraintChecker : ConstraintChecker
+ {
+ Type gt;
+
+ public TypeConstraintChecker (Type gt, Type[] gen_params, Type[] atypes,
+ Location loc)
+ : base (gen_params, atypes, loc)
+ {
+ this.gt = gt;
+ }
+
+ protected override string GetSignatureForError ()
+ {
+ return TypeManager.CSharpName (gt);
+ }
+
+ protected override void Report_SymbolRelatedToPreviousError ()
+ {
+ Report.SymbolRelatedToPreviousError (gt);
+ }
+ }
+ }
+
+ /// <summary>
+ /// A generic method definition.
+ /// </summary>
+ public class GenericMethod : DeclSpace
+ {
+ Expression return_type;
+ Parameters parameters;
+
+ public GenericMethod (NamespaceEntry ns, DeclSpace parent, MemberName name,
+ Expression return_type, Parameters parameters)
+ : base (ns, parent, name, null)
+ {
+ this.return_type = return_type;
+ this.parameters = parameters;
+ }
+
+ public override TypeBuilder DefineType ()
+ {
+ throw new Exception ();
+ }
+
+ public override bool Define ()
+ {
+ for (int i = 0; i < TypeParameters.Length; i++)
+ if (!TypeParameters [i].Resolve (this))
+ return false;
+
+ return true;
+ }
+
+ /// <summary>
+ /// Define and resolve the type parameters.
+ /// We're called from Method.Define().
+ /// </summary>
+ public bool Define (MethodBuilder mb, ToplevelBlock block)
+ {
+ TypeParameterName[] names = MemberName.TypeArguments.GetDeclarations ();
+ string[] snames = new string [names.Length];
+ for (int i = 0; i < names.Length; i++) {
+ string type_argument_name = names[i].Name;
+ Parameter p = parameters.GetParameterByName (type_argument_name);
+ if (p != null) {
+ Error_ParameterNameCollision (p.Location, type_argument_name, "method parameter");
+ return false;
+ }
+
+ snames[i] = type_argument_name;
+ }
+
+ GenericTypeParameterBuilder[] gen_params = mb.DefineGenericParameters (snames);
+ for (int i = 0; i < TypeParameters.Length; i++)
+ TypeParameters [i].Define (gen_params [i]);
+
+ if (!Define ())
+ return false;
+
+ for (int i = 0; i < TypeParameters.Length; i++) {
+ if (!TypeParameters [i].ResolveType (this))
+ return false;
+ }
+
+ return true;
+ }
+
+ internal static void Error_ParameterNameCollision (Location loc, string name, string collisionWith)
+ {
+ Report.Error (412, loc, "The type parameter name `{0}' is the same as `{1}'",
+ name, collisionWith);
+ }
+
+ /// <summary>
+ /// We're called from MethodData.Define() after creating the MethodBuilder.
+ /// </summary>
+ public bool DefineType (EmitContext ec, MethodBuilder mb,
+ MethodInfo implementing, bool is_override)
+ {
+ for (int i = 0; i < TypeParameters.Length; i++)
+ if (!TypeParameters [i].DefineType (
+ ec, mb, implementing, is_override))
+ return false;
+
+ bool ok = true;
+ foreach (Parameter p in parameters.FixedParameters){
+ if (!p.Resolve (ec))
+ ok = false;
+ }
+ if ((return_type != null) && (return_type.ResolveAsTypeTerminal (ec, false) == null))
+ ok = false;
+
+ return ok;
+ }
+
+ public void EmitAttributes ()
+ {
+ for (int i = 0; i < TypeParameters.Length; i++)
+ TypeParameters [i].Emit ();
+
+ if (OptAttributes != null)
+ OptAttributes.Emit ();
+ }
+
+ public override bool DefineMembers ()
+ {
+ return true;
+ }
+
+ public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
+ MemberFilter filter, object criteria)
+ {
+ throw new Exception ();
+ }
+
+ public override MemberCache MemberCache {
+ get {
+ return null;
+ }
+ }
+
+ public override AttributeTargets AttributeTargets {
+ get {
+ return AttributeTargets.Method | AttributeTargets.ReturnValue;
+ }
+ }
+
+ public override string DocCommentHeader {
+ get { return "M:"; }
+ }
+
+ public new void VerifyClsCompliance ()
+ {
+ foreach (TypeParameter tp in TypeParameters) {
+ if (tp.Constraints == null)
+ continue;
+
+ tp.Constraints.VerifyClsCompliance ();
+ }
+ }
+ }
+
+ public class NullableType : TypeExpr
+ {
+ Expression underlying;
+
+ public NullableType (Expression underlying, Location l)
+ {
+ this.underlying = underlying;
+ loc = l;
+
+ eclass = ExprClass.Type;
+ }
+
+ public NullableType (Type type, Location loc)
+ : this (new TypeExpression (type, loc), loc)
+ { }
+
+ public override string Name {
+ get { return underlying.ToString () + "?"; }
+ }
+
+ public override string FullName {
+ get { return underlying.ToString () + "?"; }
+ }
+
+ protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
+ {
+ TypeArguments args = new TypeArguments (loc);
+ args.Add (underlying);
+
+ ConstructedType ctype = new ConstructedType (TypeManager.generic_nullable_type, args, loc);
+ return ctype.ResolveAsTypeTerminal (ec, false);
+ }
+ }
+
+ public partial class TypeManager
+ {
+ //
+ // A list of core types that the compiler requires or uses
+ //
+ static public Type activator_type;
+ static public Type generic_ilist_type;
+ static public Type generic_icollection_type;
+ static public Type generic_ienumerator_type;
+ static public Type generic_ienumerable_type;
+ static public Type generic_nullable_type;
+
+ //
+ // These methods are called by code generated by the compiler
+ //
+ static public MethodInfo activator_create_instance;
+
+ static void InitGenericCoreTypes ()
+ {
+ activator_type = CoreLookupType ("System", "Activator");
+
+ generic_ilist_type = CoreLookupType (
+ "System.Collections.Generic", "IList", 1);
+ generic_icollection_type = CoreLookupType (
+ "System.Collections.Generic", "ICollection", 1);
+ generic_ienumerator_type = CoreLookupType (
+ "System.Collections.Generic", "IEnumerator", 1);
+ generic_ienumerable_type = CoreLookupType (
+ "System.Collections.Generic", "IEnumerable", 1);
+ generic_nullable_type = CoreLookupType (
+ "System", "Nullable", 1);
+ }
+
+ static void InitGenericCodeHelpers ()
+ {
+ // Activator
+ activator_create_instance = GetMethod (
+ activator_type, "CreateInstance", Type.EmptyTypes);
+ }
+
+ static Type CoreLookupType (string ns, string name, int arity)
+ {
+ return CoreLookupType (ns, MemberName.MakeName (name, arity));
+ }
+
+ public static TypeContainer LookupGenericTypeContainer (Type t)
+ {
+ t = DropGenericTypeArguments (t);
+ return LookupTypeContainer (t);
+ }
+
+ /// <summary>
+ /// Check whether `a' and `b' may become equal generic types.
+ /// The algorithm to do that is a little bit complicated.
+ /// </summary>
+ public static bool MayBecomeEqualGenericTypes (Type a, Type b, Type[] class_inferred,
+ Type[] method_inferred)
+ {
+ if (a.IsGenericParameter) {
+ //
+ // If a is an array of a's type, they may never
+ // become equal.
+ //
+ while (b.IsArray) {
+ b = b.GetElementType ();
+ if (a.Equals (b))
+ return false;
+ }
+
+ //
+ // If b is a generic parameter or an actual type,
+ // they may become equal:
+ //
+ // class X<T,U> : I<T>, I<U>
+ // class X<T> : I<T>, I<float>
+ //
+ if (b.IsGenericParameter || !b.IsGenericType) {
+ int pos = a.GenericParameterPosition;
+ Type[] args = a.DeclaringMethod != null ? method_inferred : class_inferred;
+ if (args [pos] == null) {
+ args [pos] = b;
+ return true;
+ }
+
+ return args [pos] == a;
+ }
+
+ //
+ // We're now comparing a type parameter with a
+ // generic instance. They may become equal unless
+ // the type parameter appears anywhere in the
+ // generic instance:
+ //
+ // class X<T,U> : I<T>, I<X<U>>
+ // -> error because you could instanciate it as
+ // X<X<int>,int>
+ //
+ // class X<T> : I<T>, I<X<T>> -> ok
+ //
+
+ Type[] bargs = GetTypeArguments (b);
+ for (int i = 0; i < bargs.Length; i++) {
+ if (a.Equals (bargs [i]))
+ return false;
+ }
+
+ return true;
+ }
+
+ if (b.IsGenericParameter)
+ return MayBecomeEqualGenericTypes (b, a, class_inferred, method_inferred);
+
+ //
+ // At this point, neither a nor b are a type parameter.
+ //
+ // If one of them is a generic instance, let
+ // MayBecomeEqualGenericInstances() compare them (if the
+ // other one is not a generic instance, they can never
+ // become equal).
+ //
+
+ if (a.IsGenericType || b.IsGenericType)
+ return MayBecomeEqualGenericInstances (a, b, class_inferred, method_inferred);
+
+ //
+ // If both of them are arrays.
+ //
+
+ if (a.IsArray && b.IsArray) {
+ if (a.GetArrayRank () != b.GetArrayRank ())
+ return false;
+
+ a = a.GetElementType ();
+ b = b.GetElementType ();
+
+ return MayBecomeEqualGenericTypes (a, b, class_inferred, method_inferred);
+ }
+
+ //
+ // Ok, two ordinary types.
+ //
+
+ return a.Equals (b);
+ }
+
+ //
+ // Checks whether two generic instances may become equal for some
+ // particular instantiation (26.3.1).
+ //
+ public static bool MayBecomeEqualGenericInstances (Type a, Type b,
+ Type[] class_inferred,
+ Type[] method_inferred)
+ {
+ if (!a.IsGenericType || !b.IsGenericType)
+ return false;
+ if (a.GetGenericTypeDefinition () != b.GetGenericTypeDefinition ())
+ return false;
+
+ return MayBecomeEqualGenericInstances (
+ GetTypeArguments (a), GetTypeArguments (b), class_inferred, method_inferred);
+ }
+
+ public static bool MayBecomeEqualGenericInstances (Type[] aargs, Type[] bargs,
+ Type[] class_inferred,
+ Type[] method_inferred)
+ {
+ if (aargs.Length != bargs.Length)
+ return false;
+
+ for (int i = 0; i < aargs.Length; i++) {
+ if (!MayBecomeEqualGenericTypes (aargs [i], bargs [i], class_inferred, method_inferred))
+ return false;
+ }
+
+ return true;
+ }
+
+ /// <summary>
+ /// Type inference. Try to infer the type arguments from the params method
+ /// `method', which is invoked with the arguments `arguments'. This is used
+ /// when resolving an Invocation or a DelegateInvocation and the user
+ /// did not explicitly specify type arguments.
+ /// </summary>
+ public static bool InferParamsTypeArguments (EmitContext ec, ArrayList arguments,
+ ref MethodBase method)
+ {
+ if (!TypeManager.IsGenericMethod (method))
+ return true;
+
+ // if there are no arguments, there's no way to infer the type-arguments
+ if (arguments == null || arguments.Count == 0)
+ return false;
+
+ ParameterData pd = TypeManager.GetParameterData (method);
+ int pd_count = pd.Count;
+ int arg_count = arguments.Count;
+
+ if (pd_count == 0)
+ return false;
+
+ if (pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS)
+ return false;
+
+ if (pd_count - 1 > arg_count)
+ return false;
+
+ Type[] method_args = method.GetGenericArguments ();
+ Type[] inferred_types = new Type [method_args.Length];
+
+ //
+ // If we have come this far, the case which
+ // remains is when the number of parameters is
+ // less than or equal to the argument count.
+ //
+ for (int i = 0; i < pd_count - 1; ++i) {
+ Argument a = (Argument) arguments [i];
+
+ if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr))
+ continue;
+
+ Type pt = pd.ParameterType (i);
+ Type at = a.Type;
+
+ if (!TypeInferenceV2.UnifyType (pt, at, inferred_types))
+ return false;
+ }
+
+ Type element_type = TypeManager.GetElementType (pd.ParameterType (pd_count - 1));
+
+ for (int i = pd_count - 1; i < arg_count; i++) {
+ Argument a = (Argument) arguments [i];
+
+ if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr))
+ continue;
+
+ if (!TypeInferenceV2.UnifyType (element_type, a.Type, inferred_types))
+ return false;
+ }
+
+ for (int i = 0; i < inferred_types.Length; i++)
+ if (inferred_types [i] == null)
+ return false;
+
+ method = ((MethodInfo)method).MakeGenericMethod (inferred_types);
+ return true;
+ }
+
+ /// <summary>
+ /// Type inference. Try to infer the type arguments from `method',
+ /// which is invoked with the arguments `arguments'. This is used
+ /// when resolving an Invocation or a DelegateInvocation and the user
+ /// did not explicitly specify type arguments.
+ /// </summary>
+ public static int InferTypeArguments (EmitContext ec,
+ ArrayList arguments,
+ ref MethodBase method)
+ {
+ ATypeInference ti = ATypeInference.CreateInstance (arguments);
+ Type[] i_args = ti.InferMethodArguments (ec, method);
+ if (i_args == null)
+ return ti.InferenceScore;
+
+ if (i_args.Length == 0)
+ return 0;
+
+ method = ((MethodInfo) method).MakeGenericMethod (i_args);
+ return 0;
+ }
+
+ /// <summary>
+ /// Type inference.
+ /// </summary>
+ public static bool InferTypeArguments (ParameterData apd,
+ ref MethodBase method)
+ {
+ if (!TypeManager.IsGenericMethod (method))
+ return true;
+
+ ATypeInference ti = ATypeInference.CreateInstance (ArrayList.Adapter (apd.Types));
+ Type[] i_args = ti.InferDelegateArguments (method);
+ if (i_args == null)
+ return false;
+
+ method = ((MethodInfo) method).MakeGenericMethod (i_args);
+ return true;
+ }
+ }
+
+ abstract class ATypeInference
+ {
+ protected readonly ArrayList arguments;
+ protected readonly int arg_count;
+
+ protected ATypeInference (ArrayList arguments)
+ {
+ this.arguments = arguments;
+ if (arguments != null)
+ arg_count = arguments.Count;
+ }
+
+ public static ATypeInference CreateInstance (ArrayList arguments)
+ {
+ if (RootContext.Version == LanguageVersion.ISO_2)
+ return new TypeInferenceV2 (arguments);
+
+ return new TypeInferenceV3 (arguments);
+ }
+
+ public virtual int InferenceScore {
+ get {
+ return int.MaxValue;
+ }
+ }
+
+ public abstract Type[] InferMethodArguments (EmitContext ec, MethodBase method);
+ public abstract Type[] InferDelegateArguments (MethodBase method);
+ }
+
+ //
+ // Implements C# 2.0 type inference
+ //
+ class TypeInferenceV2 : ATypeInference
+ {
+ public TypeInferenceV2 (ArrayList arguments)
+ : base (arguments)
+ {
+ }
+
+ public override Type[] InferDelegateArguments (MethodBase method)
+ {
+ ParameterData pd = TypeManager.GetParameterData (method);
+ if (arg_count != pd.Count)
+ return null;
+
+ Type[] method_args = method.GetGenericArguments ();
+ Type[] inferred_types = new Type[method_args.Length];
+
+ Type[] param_types = new Type[pd.Count];
+ Type[] arg_types = (Type[])arguments.ToArray (typeof (Type));
+
+ for (int i = 0; i < arg_count; i++) {
+ param_types[i] = pd.ParameterType (i);
+ }
+
+ if (!InferTypeArguments (param_types, arg_types, inferred_types))
+ return null;
+
+ return inferred_types;
+ }
+
+ public override Type[] InferMethodArguments (EmitContext ec, MethodBase method)
+ {
+ ParameterData pd = TypeManager.GetParameterData (method);
+ if (arg_count != pd.Count)
+ return null;
+
+ Type[] method_generic_args = method.GetGenericArguments ();
+ Type[] arg_types = new Type[pd.Count];
+ for (int i = 0; i < arg_count; i++) {
+ Argument a = (Argument) arguments[i];
+ if (a.Expr is NullLiteral || a.Expr is MethodGroupExpr || a.Expr is AnonymousMethodExpression)
+ continue;
+
+ arg_types[i] = a.Type;
+ }
+
+ Type[] inferred_types = new Type [method_generic_args.Length];
+ if (!InferTypeArguments (pd.Types, arg_types, inferred_types))
+ return null;
+
+ return inferred_types;
+ }
+
+ static bool InferTypeArguments (Type[] param_types, Type[] arg_types,
+ Type[] inferred_types)
+ {
+ for (int i = 0; i < arg_types.Length; i++) {
+ if (arg_types[i] == null)
+ continue;
+
+ if (!UnifyType (param_types[i], arg_types[i], inferred_types))
+ return false;
+ }
+
+ for (int i = 0; i < inferred_types.Length; ++i)
+ if (inferred_types[i] == null)
+ return false;
+
+ return true;
+ }
+
+ public static bool UnifyType (Type pt, Type at, Type[] inferred)
+ {
+ if (pt.IsGenericParameter) {
+ if (pt.DeclaringMethod == null)
+ return pt == at;
+
+ int pos = pt.GenericParameterPosition;
+
+ if (inferred [pos] == null)
+ inferred [pos] = at;
+
+ return inferred [pos] == at;
+ }
+
+ if (!pt.ContainsGenericParameters) {
+ if (at.ContainsGenericParameters)
+ return UnifyType (at, pt, inferred);
+ else
+ return true;
+ }
+
+ if (at.IsArray) {
+ if (pt.IsArray) {
+ if (at.GetArrayRank () != pt.GetArrayRank ())
+ return false;
+
+ return UnifyType (pt.GetElementType (), at.GetElementType (), inferred);
+ }
+
+ if (!pt.IsGenericType)
+ return false;
+
+ Type gt = pt.GetGenericTypeDefinition ();
+ if ((gt != TypeManager.generic_ilist_type) && (gt != TypeManager.generic_icollection_type) &&
+ (gt != TypeManager.generic_ienumerable_type))
+ return false;
+
+ Type[] args = TypeManager.GetTypeArguments (pt);
+ return UnifyType (args[0], at.GetElementType (), inferred);
+ }
+
+ if (pt.IsArray) {
+ if (!at.IsArray ||
+ (pt.GetArrayRank () != at.GetArrayRank ()))
+ return false;
+
+ return UnifyType (pt.GetElementType (), at.GetElementType (), inferred);
+ }
+
+ if (pt.IsByRef && at.IsByRef)
+ return UnifyType (pt.GetElementType (), at.GetElementType (), inferred);
+ ArrayList list = new ArrayList ();
+ if (at.IsGenericType)
+ list.Add (at);
+ for (Type bt = at.BaseType; bt != null; bt = bt.BaseType)
+ list.Add (bt);
+
+ list.AddRange (TypeManager.GetInterfaces (at));
+
+ foreach (Type type in list) {
+ if (!type.IsGenericType)
+ continue;
+
+ if (TypeManager.DropGenericTypeArguments (pt) != TypeManager.DropGenericTypeArguments (type))
+ continue;
+
+ if (!UnifyTypes (pt.GetGenericArguments (), type.GetGenericArguments (), inferred))
+ return false;
+ }
+
+ return true;
+ }
+
+ static bool UnifyTypes (Type[] pts, Type[] ats, Type[] inferred)
+ {
+ for (int i = 0; i < ats.Length; i++) {
+ if (!UnifyType (pts [i], ats [i], inferred))
+ return false;
+ }
+ return true;
+ }
+ }
+
+ //
+ // Implements C# 3.0 type inference
+ //
+ class TypeInferenceV3 : ATypeInference
+ {
+ //
+ // Tracks successful rate of type inference
+ //
+ int score = int.MaxValue;
+
+ public TypeInferenceV3 (ArrayList arguments)
+ : base (arguments)
+ {
+ }
+
+ public override int InferenceScore {
+ get {
+ return score;
+ }
+ }
+
+ public override Type[] InferDelegateArguments (MethodBase method)
+ {
+ ParameterData pd = TypeManager.GetParameterData (method);
+ if (arg_count != pd.Count)
+ return null;
+
+ Type[] d_gargs = method.GetGenericArguments ();
+ TypeInferenceContext context = new TypeInferenceContext (d_gargs);
+
+ // A lower-bound inference is made from each argument type Uj of D
+ // to the corresponding parameter type Tj of M
+ for (int i = 0; i < arg_count; ++i) {
+ Type t = pd.Types [i];
+ if (!t.IsGenericParameter)
+ continue;
+
+ context.LowerBoundInference ((Type)arguments[i], t);
+ }
+
+ if (!context.FixAllTypes ())
+ return null;
+
+ return context.InferredTypeArguments;
+ }
+
+ public override Type[] InferMethodArguments (EmitContext ec, MethodBase method)
+ {
+ Type[] method_generic_args = method.GetGenericArguments ();
+ TypeInferenceContext context = new TypeInferenceContext (method_generic_args);
+ if (!context.UnfixedVariableExists)
+ return Type.EmptyTypes;
+
+ ParameterData pd = TypeManager.GetParameterData (method);
+ if (!InferInPhases (ec, context, pd))
+ return null;
+
+ return context.InferredTypeArguments;
+ }
+
+ //
+ // Implements method type arguments inference
+ //
+ bool InferInPhases (EmitContext ec, TypeInferenceContext tic, ParameterData methodParameters)
+ {
+ //
+ // The first inference phase
+ //
+ for (int i = 0; i < arg_count; i++) {
+ Type method_parameter = methodParameters.ParameterType (i);
+
+ Argument a = (Argument) arguments[i];
+
+ //
+ // When a lambda expression, an anonymous method
+ // is used an explicit argument type inference takes a place
+ //
+ AnonymousMethodExpression am = a.Expr as AnonymousMethodExpression;
+ if (am != null) {
+ if (am.ExplicitTypeInference (tic, method_parameter))
+ --score;
+ continue;
+ }
+
+ if (a.Expr.Type == TypeManager.null_type)
+ continue;
+
+ //
+ // Otherwise an output type inference is made
+ //
+ score -= tic.OutputTypeInference (ec, a.Expr, method_parameter);
+ }
+
+ //
+ // Part of the second phase but because it happens only once
+ // we don't need to call it in cycle
+ //
+ bool fixed_any = false;
+ if (!tic.FixIndependentTypeArguments (methodParameters, ref fixed_any))
+ return false;
+
+ return DoSecondPhase (ec, tic, methodParameters, !fixed_any);
+ }
+
+ bool DoSecondPhase (EmitContext ec, TypeInferenceContext tic, ParameterData methodParameters, bool fixDependent)
+ {
+ bool fixed_any = false;
+ if (fixDependent && !tic.FixDependentTypes (methodParameters, ref fixed_any))
+ return false;
+
+ // If no further unfixed type variables exist, type inference succeeds
+ if (!tic.UnfixedVariableExists)
+ return true;
+
+ if (!fixed_any && fixDependent)
+ return false;
+
+ // For all arguments where the corresponding argument output types
+ // contain unfixed type variables but the input types do not,
+ // an output type inference is made
+ for (int i = 0; i < arg_count; i++) {
+ Type t_i = methodParameters.ParameterType (i);
+ if (!TypeManager.IsDelegateType (t_i))
+ continue;
+
+ MethodInfo mi = Delegate.GetInvokeMethod (t_i, t_i);
+ Type rtype = mi.ReturnType;
+
+#if MS_COMPATIBLE
+ // Blablabla, because reflection does not work with dynamic types
+ Type[] g_args = t_i.GetGenericArguments ();
+ rtype = g_args[rtype.GenericParameterPosition];
+#endif
+
+ if (tic.IsReturnTypeNonDependent (mi, rtype))
+ score -= tic.OutputTypeInference (ec, ((Argument) arguments [i]).Expr, t_i);
+ }
+
+
+ return DoSecondPhase (ec, tic, methodParameters, true);
+ }
+ }
+
+ public class TypeInferenceContext
+ {
+ readonly Type[] unfixed_types;
+ readonly Type[] fixed_types;
+ readonly ArrayList[] bounds;
+
+ public TypeInferenceContext (Type[] typeArguments)
+ {
+ if (typeArguments.Length == 0)
+ throw new ArgumentException ("Empty generic arguments");
+
+ fixed_types = new Type [typeArguments.Length];
+ for (int i = 0; i < typeArguments.Length; ++i) {
+ if (typeArguments [i].IsGenericParameter) {
+ if (bounds == null) {
+ bounds = new ArrayList [typeArguments.Length];
+ unfixed_types = new Type [typeArguments.Length];
+ }
+ unfixed_types [i] = typeArguments [i];
+ } else {
+ fixed_types [i] = typeArguments [i];
+ }
+ }
+ }
+
+ public Type[] InferredTypeArguments {
+ get {
+ return fixed_types;
+ }
+ }
+
+ void AddToBounds (Type t, int index)
+ {
+ ArrayList a = bounds[index];
+ if (a == null) {
+ a = new ArrayList ();
+ a.Add (t);
+ bounds[index] = a;
+ return;
+ }
+
+ if (a.Contains (t))
+ return;
+
+ a.Add (t);
+ }
+
+ bool AllTypesAreFixed (Type[] types)
+ {
+ foreach (Type t in types) {
+ if (t.IsGenericParameter) {
+ if (!IsFixed (t))
+ return false;
+ continue;
+ }
+
+ if (t.IsGenericType)
+ return AllTypesAreFixed (t.GetGenericArguments ());
+ }
+
+ return true;
+ }
+
+ //
+ // 26.3.3.8 Exact Inference
+ //
+ public int ExactInference (Type u, Type v)
+ {
+ // If V is an array type
+ if (v.IsArray) {
+ if (!u.IsArray)
+ return 0;
+
+ if (u.GetArrayRank () != v.GetArrayRank ())
+ return 0;
+
+ return ExactInference (TypeManager.GetElementType (u), TypeManager.GetElementType (v));
+ }
+
+ // If V is constructed type and U is constructed type
+ if (v.IsGenericType && !v.IsGenericTypeDefinition) {
+ if (!u.IsGenericType)
+ return 0;
+
+ Type [] ga_u = u.GetGenericArguments ();
+ Type [] ga_v = v.GetGenericArguments ();
+ if (ga_u.Length != ga_v.Length)
+ return 0;
+
+ int score = 0;
+ for (int i = 0; i < ga_u.Length; ++i)
+ score += ExactInference (ga_u [i], ga_v [i]);
+
+ return score > 0 ? 1 : 0;
+ }
+
+ // If V is one of the unfixed type arguments
+ int pos = IsUnfixed (v);
+ if (pos == -1)
+ return 0;
+
+ AddToBounds (u, pos);
+ return 1;
+ }
+
+ public bool FixAllTypes ()
+ {
+ for (int i = 0; i < unfixed_types.Length; ++i) {
+ if (!FixType (i))
+ return false;
+ }
+ return true;
+ }
+
+ //
+ // All unfixed type variables Xi are fixed for which all of the following hold:
+ // a, There is at least one type variable Xj that depends on Xi
+ // b, Xi has a non-empty set of bounds
+ //
+ public bool FixDependentTypes (ParameterData methodParameters, ref bool fixed_any)
+ {
+ for (int i = 0; i < unfixed_types.Length; ++i) {
+ if (unfixed_types[i] == null)
+ continue;
+
+ if (bounds[i] == null)
+ continue;
+
+ if (!FixType (i))
+ return false;
+
+ fixed_any = true;
+ }
+
+ return true;
+ }
+
+ //
+ // All unfixed type variables Xi which depend on no Xj are fixed
+ //
+ public bool FixIndependentTypeArguments (ParameterData methodParameters, ref bool fixed_any)
+ {
+ ArrayList types_to_fix = new ArrayList (unfixed_types);
+ foreach (Type t in methodParameters.Types) {
+ if (t.IsGenericParameter)
+ continue;
+
+ if (!TypeManager.IsDelegateType (t))
+ continue;
+
+ MethodInfo invoke = Delegate.GetInvokeMethod (t, t);
+ Type rtype = invoke.ReturnType;
+ if (!rtype.IsGenericParameter && !rtype.IsGenericType)
+ continue;
+
+#if MS_COMPATIBLE
+ // Blablabla, because reflection does not work with dynamic types
+ if (rtype.IsGenericParameter) {
+ Type [] g_args = t.GetGenericArguments ();
+ rtype = g_args [rtype.GenericParameterPosition];
+ }
+#endif
+ // Remove dependent types, they cannot be fixed yet
+ RemoveDependentTypes (types_to_fix, rtype);
+ }
+
+ foreach (Type t in types_to_fix) {
+ if (t == null)
+ continue;
+
+ int idx = IsUnfixed (t);
+ if (idx >= 0 && !FixType (idx)) {
+ return false;
+ }
+ }
+
+ fixed_any = types_to_fix.Count > 0;
+ return true;
+ }
+
+ //
+ // 26.3.3.10 Fixing
+ //
+ public bool FixType (int i)
+ {
+ // It's already fixed
+ if (unfixed_types[i] == null)
+ throw new InternalErrorException ("Type argument has been already fixed");
+
+ ArrayList candidates = (ArrayList)bounds [i];
+ if (candidates == null)
+ return false;
+
+ if (candidates.Count == 1) {
+ unfixed_types[i] = null;
+ fixed_types[i] = (Type)candidates[0];
+ return true;
+ }
+
+ // TODO: Review, I think it is still wrong
+ Type best_candidate = null;
+ for (int ci = 0; ci < candidates.Count; ++ci) {
+ TypeExpr candidate = new TypeExpression ((Type)candidates[ci], Location.Null);
+ bool failed = false;
+ for (int cii = 0; cii < candidates.Count; ++cii) {
+ if (cii == ci)
+ continue;
+
+ if (!Convert.ImplicitStandardConversionExists (candidate, (Type)candidates[cii])) {
+ failed = true;
+ }
+ }
+
+ if (failed)
+ continue;
+
+ if (best_candidate != null)
+ return false;
+
+ best_candidate = candidate.Type;
+ }
+
+ if (best_candidate == null)
+ return false;
+
+ unfixed_types[i] = null;
+ fixed_types[i] = best_candidate;
+ return true;
+ }
+
+ //
+ // Uses inferred types to inflate delegate type argument
+ //
+ public Type InflateGenericArgument (Type parameter)
+ {
+ if (parameter.IsGenericParameter)
+ return fixed_types [parameter.GenericParameterPosition];
+
+ if (parameter.IsGenericType) {
+ Type [] parameter_targs = parameter.GetGenericArguments ();
+ for (int ii = 0; ii < parameter_targs.Length; ++ii) {
+ parameter_targs [ii] = InflateGenericArgument (parameter_targs [ii]);
+ }
+ return parameter.GetGenericTypeDefinition ().MakeGenericType (parameter_targs);
+ }
+
+ return parameter;
+ }
+
+ //
+ // Tests whether all delegate input arguments are fixed and generic output type
+ // requires output type inference
+ //
+ public bool IsReturnTypeNonDependent (MethodInfo invoke, Type returnType)
+ {
+ if (returnType.IsGenericParameter) {
+ if (IsFixed (returnType))
+ return false;
+ } else if (returnType.IsGenericType) {
+ if (TypeManager.IsDelegateType (returnType)) {
+ invoke = Delegate.GetInvokeMethod (returnType, returnType);
+ return IsReturnTypeNonDependent (invoke, invoke.ReturnType);
+ }
+
+ Type[] g_args = returnType.GetGenericArguments ();
+
+ // At least one unfixed return type has to exist
+ if (AllTypesAreFixed (g_args))
+ return false;
+ } else {
+ return false;
+ }
+
+ // All generic input arguments have to be fixed
+ ParameterData d_parameters = TypeManager.GetParameterData (invoke);
+ return AllTypesAreFixed (d_parameters.Types);
+ }
+
+ bool IsFixed (Type type)
+ {
+ return IsUnfixed (type) == -1;
+ }
+
+ int IsUnfixed (Type type)
+ {
+ if (!type.IsGenericParameter)
+ return -1;
+
+ //return unfixed_types[type.GenericParameterPosition] != null;
+ for (int i = 0; i < unfixed_types.Length; ++i) {
+ if (unfixed_types [i] == type)
+ return i;
+ }
+
+ return -1;
+ }
+
+ //
+ // 26.3.3.9 Lower-bound Inference
+ //
+ public int LowerBoundInference (Type u, Type v)
+ {
+ // Remove ref, out modifiers
+ if (v.IsByRef)
+ v = v.GetElementType ();
+
+ // If U is an array type
+ if (u.IsArray) {
+ int u_dim = u.GetArrayRank ();
+ Type v_e;
+ Type u_e = TypeManager.GetElementType (u);
+
+ if (v.IsArray) {
+ if (u_dim != v.GetArrayRank ())
+ return 0;
+
+ v_e = TypeManager.GetElementType (v);
+
+ if (u.IsByRef) {
+ return LowerBoundInference (u_e, v_e);
+ }
+
+ return ExactInference (u_e, v_e);
+ }
+
+ if (u_dim != 1)
+ return 0;
+
+ if (v.IsGenericType) {
+ Type g_v = v.GetGenericTypeDefinition ();
+ if ((g_v != TypeManager.generic_ilist_type) && (g_v != TypeManager.generic_icollection_type) &&
+ (g_v != TypeManager.generic_ienumerable_type))
+ return 0;
+
+ v_e = TypeManager.GetTypeArguments (v)[0];
+
+ if (u.IsByRef) {
+ return LowerBoundInference (u_e, v_e);
+ }
+
+ return ExactInference (u_e, v_e);
+ }
+ } else if (v.IsGenericType && !v.IsGenericTypeDefinition) {
+ //
+ // if V is a constructed type C<V1..Vk> and there is a unique set of types U1..Uk
+ // such that a standard implicit conversion exists from U to C<U1..Uk> then an exact
+ // inference is made from each Ui for the corresponding Vi
+ //
+ ArrayList u_candidates = new ArrayList ();
+ if (u.IsGenericType)
+ u_candidates.Add (u);
+
+ for (Type t = u.BaseType; t != null; t = t.BaseType) {
+ if (t.IsGenericType && !t.IsGenericTypeDefinition)
+ u_candidates.Add (t);
+ }
+
+ // TODO: Implement GetGenericInterfaces only and remove
+ // the if from foreach
+ u_candidates.AddRange (TypeManager.GetInterfaces (u));
+
+ Type open_v = v.GetGenericTypeDefinition ();
+ foreach (Type u_candidate in u_candidates) {
+ if (!u_candidate.IsGenericType || u_candidate.IsGenericTypeDefinition)
+ continue;
+
+ if (TypeManager.DropGenericTypeArguments (u_candidate) != open_v)
+ continue;
+
+ Type [] ga_u = u_candidate.GetGenericArguments ();
+ Type [] ga_v = v.GetGenericArguments ();
+ int score = 0;
+ for (int i = 0; i < ga_u.Length; ++i)
+ score += ExactInference (ga_u [i], ga_v [i]);
+
+ return score > 0 ? 1 : 0;
+ }
+ return 0;
+ }
+
+ // If V is one of the unfixed type arguments
+ int pos = IsUnfixed (v);
+ if (pos == -1)
+ return 0;
+
+ AddToBounds (u, pos);
+ return 1;
+ }
+
+ //
+ // 26.3.3.6 Output Type Inference
+ //
+ public int OutputTypeInference (EmitContext ec, Expression e, Type t)
+ {
+ // If e is a lambda or anonymous method with inferred return type
+ AnonymousMethodExpression ame = e as AnonymousMethodExpression;
+ if (ame != null) {
+ Type rt = ame.InferReturnType (ec, this, t);
+ MethodInfo invoke = Delegate.GetInvokeMethod (t, t);
+
+ if (rt == null) {
+ ParameterData pd = TypeManager.GetParameterData (invoke);
+ return ame.Parameters.Count == pd.Count ? 1 : 0;
+ }
+
+ Type rtype = invoke.ReturnType;
+#if MS_COMPATIBLE
+ // Blablabla, because reflection does not work with dynamic types
+ Type [] g_args = t.GetGenericArguments ();
+ rtype = g_args [rtype.GenericParameterPosition];
+#endif
+ return LowerBoundInference (rt, rtype) + 1;
+ }
+
+ if (e is MethodGroupExpr) {
+ MethodInfo invoke = Delegate.GetInvokeMethod (t, t);
+ Type rtype = invoke.ReturnType;
+ if (!TypeManager.IsGenericType (rtype))
+ return 0;
+
+ throw new NotImplementedException ();
+ }
+
+ //
+ // if e is an expression with type U, then
+ // a lower-bound inference is made from U for T
+ //
+ return LowerBoundInference (e.Type, t) * 2;
+ }
+
+ static void RemoveDependentTypes (ArrayList types, Type returnType)
+ {
+ if (returnType.IsGenericParameter) {
+ types [returnType.GenericParameterPosition] = null;
+ return;
+ }
+
+ if (returnType.IsGenericType) {
+ foreach (Type t in returnType.GetGenericArguments ()) {
+ RemoveDependentTypes (types, t);
+ }
+ }
+ }
+
+ public bool UnfixedVariableExists {
+ get {
+ if (unfixed_types == null)
+ return false;
+
+ foreach (Type ut in unfixed_types)
+ if (ut != null)
+ return true;
+ return false;
+ }
+ }
+ }
+
+ public abstract class Nullable
+ {
+ public sealed class NullableInfo
+ {
+ public readonly Type Type;
+ public readonly Type UnderlyingType;
+ public readonly MethodInfo HasValue;
+ public readonly MethodInfo Value;
+ public readonly ConstructorInfo Constructor;
+
+ public NullableInfo (Type type)
+ {
+ Type = type;
+ UnderlyingType = TypeManager.GetTypeArguments (type) [0];
+
+ PropertyInfo has_value_pi = TypeManager.GetProperty (type, "HasValue");
+ PropertyInfo value_pi = TypeManager.GetProperty (type, "Value");
+
+ HasValue = has_value_pi.GetGetMethod (false);
+ Value = value_pi.GetGetMethod (false);
+ Constructor = type.GetConstructor (new Type[] { UnderlyingType });
+ }
+ }
+
+ public class HasValue : Expression
+ {
+ Expression expr;
+ NullableInfo info;
+
+ private HasValue (Expression expr)
+ {
+ this.expr = expr;
+ }
+
+ public static Expression Create (Expression expr, EmitContext ec)
+ {
+ return new HasValue (expr).Resolve (ec);
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ ((IMemoryLocation) expr).AddressOf (ec, AddressOp.LoadStore);
+ ec.ig.EmitCall (OpCodes.Call, info.HasValue, null);
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ this.info = new NullableInfo (expr.Type);
+
+ type = TypeManager.bool_type;
+ eclass = expr.eclass;
+ return this;
+ }
+ }
+
+ public class Unwrap : Expression, IMemoryLocation, IAssignMethod
+ {
+ Expression expr;
+ NullableInfo info;
+
+ LocalTemporary temp;
+ bool has_temp;
+
+ protected Unwrap (Expression expr)
+ {
+ this.expr = expr;
+ this.loc = expr.Location;
+ }
+
+ public static Unwrap Create (Expression expr, EmitContext ec)
+ {
+ return new Unwrap (expr).Resolve (ec) as Unwrap;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ expr = expr.Resolve (ec);
+ if (expr == null)
+ return null;
+
+ temp = new LocalTemporary (expr.Type);
+
+ info = new NullableInfo (expr.Type);
+ type = info.UnderlyingType;
+ eclass = expr.eclass;
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ AddressOf (ec, AddressOp.LoadStore);
+ ec.ig.EmitCall (OpCodes.Call, info.Value, null);
+ }
+
+ public void EmitCheck (EmitContext ec)
+ {
+ AddressOf (ec, AddressOp.LoadStore);
+ ec.ig.EmitCall (OpCodes.Call, info.HasValue, null);
+ }
+
+ public void Store (EmitContext ec)
+ {
+ create_temp (ec);
+ }
+
+ void create_temp (EmitContext ec)
+ {
+ if ((temp != null) && !has_temp) {
+ expr.Emit (ec);
+ temp.Store (ec);
+ has_temp = true;
+ }
+ }
+
+ public void AddressOf (EmitContext ec, AddressOp mode)
+ {
+ create_temp (ec);
+ if (temp != null)
+ temp.AddressOf (ec, AddressOp.LoadStore);
+ else
+ ((IMemoryLocation) expr).AddressOf (ec, AddressOp.LoadStore);
+ }
+
+ public void Emit (EmitContext ec, bool leave_copy)
+ {
+ create_temp (ec);
+ if (leave_copy) {
+ if (temp != null)
+ temp.Emit (ec);
+ else
+ expr.Emit (ec);
+ }
+
+ Emit (ec);
+ }
+
+ public void EmitAssign (EmitContext ec, Expression source,
+ bool leave_copy, bool prepare_for_load)
+ {
+ InternalWrap wrap = new InternalWrap (source, info, loc);
+ ((IAssignMethod) expr).EmitAssign (ec, wrap, leave_copy, false);
+ }
+
+ protected class InternalWrap : Expression
+ {
+ public Expression expr;
+ public NullableInfo info;
+
+ public InternalWrap (Expression expr, NullableInfo info, Location loc)
+ {
+ this.expr = expr;
+ this.info = info;
+ this.loc = loc;
+
+ type = info.Type;
+ eclass = ExprClass.Value;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ expr.Emit (ec);
+ ec.ig.Emit (OpCodes.Newobj, info.Constructor);
+ }
+ }
+ }
+
+ public class Wrap : Expression
+ {
+ Expression expr;
+ NullableInfo info;
+
+ protected Wrap (Expression expr)
+ {
+ this.expr = expr;
+ this.loc = expr.Location;
+ }
+
+ public static Wrap Create (Expression expr, EmitContext ec)
+ {
+ return new Wrap (expr).Resolve (ec) as Wrap;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ expr = expr.Resolve (ec);
+ if (expr == null)
+ return null;
+
+ TypeExpr target_type = new NullableType (expr.Type, loc);
+ target_type = target_type.ResolveAsTypeTerminal (ec, false);
+ if (target_type == null)
+ return null;
+
+ type = target_type.Type;
+ info = new NullableInfo (type);
+ eclass = ExprClass.Value;
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ expr.Emit (ec);
+ ec.ig.Emit (OpCodes.Newobj, info.Constructor);
+ }
+ }
+
+ public class NullableLiteral : NullLiteral, IMemoryLocation {
+ public NullableLiteral (Type target_type, Location loc)
+ : base (loc)
+ {
+ this.type = target_type;
+
+ eclass = ExprClass.Value;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ LocalTemporary value_target = new LocalTemporary (type);
+
+ value_target.AddressOf (ec, AddressOp.Store);
+ ec.ig.Emit (OpCodes.Initobj, type);
+ value_target.Emit (ec);
+ }
+
+ public void AddressOf (EmitContext ec, AddressOp Mode)
+ {
+ LocalTemporary value_target = new LocalTemporary (type);
+
+ value_target.AddressOf (ec, AddressOp.Store);
+ ec.ig.Emit (OpCodes.Initobj, type);
+ ((IMemoryLocation) value_target).AddressOf (ec, Mode);
+ }
+ }
+
+ public abstract class Lifted : Expression, IMemoryLocation
+ {
+ Expression expr, underlying, wrap, null_value;
+ Unwrap unwrap;
+
+ protected Lifted (Expression expr, Location loc)
+ {
+ this.expr = expr;
+ this.loc = loc;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ expr = expr.Resolve (ec);
+ if (expr == null)
+ return null;
+
+ unwrap = Unwrap.Create (expr, ec);
+ if (unwrap == null)
+ return null;
+
+ underlying = ResolveUnderlying (unwrap, ec);
+ if (underlying == null)
+ return null;
+
+ wrap = Wrap.Create (underlying, ec);
+ if (wrap == null)
+ return null;
+
+ null_value = new NullableLiteral (wrap.Type, loc).Resolve (ec);
+ if (null_value == null)
+ return null;
+
+ type = wrap.Type;
+ eclass = ExprClass.Value;
+ return this;
+ }
+
+ protected abstract Expression ResolveUnderlying (Expression unwrap, EmitContext ec);
+
+ public override void Emit (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+ Label is_null_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+
+ wrap.Emit (ec);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (is_null_label);
+ null_value.Emit (ec);
+
+ ig.MarkLabel (end_label);
+ }
+
+ public void AddressOf (EmitContext ec, AddressOp mode)
+ {
+ unwrap.AddressOf (ec, mode);
+ }
+ }
+
+ public class LiftedConversion : Lifted
+ {
+ public readonly bool IsUser;
+ public readonly bool IsExplicit;
+ public readonly Type TargetType;
+
+ public LiftedConversion (Expression expr, Type target_type, bool is_user,
+ bool is_explicit, Location loc)
+ : base (expr, loc)
+ {
+ this.IsUser = is_user;
+ this.IsExplicit = is_explicit;
+ this.TargetType = target_type;
+ }
+
+ protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
+ {
+ Type type = TypeManager.GetTypeArguments (TargetType) [0];
+
+ if (IsUser) {
+ return Convert.UserDefinedConversion (ec, unwrap, type, loc, IsExplicit);
+ } else {
+ if (IsExplicit)
+ return Convert.ExplicitConversion (ec, unwrap, type, loc);
+ else
+ return Convert.ImplicitConversion (ec, unwrap, type, loc);
+ }
+ }
+ }
+
+ public class LiftedUnaryOperator : Lifted
+ {
+ public readonly Unary.Operator Oper;
+
+ public LiftedUnaryOperator (Unary.Operator op, Expression expr, Location loc)
+ : base (expr, loc)
+ {
+ this.Oper = op;
+ }
+
+ protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
+ {
+ return new Unary (Oper, unwrap, loc);
+ }
+ }
+
+ public class LiftedConditional : Lifted
+ {
+ Expression true_expr, false_expr;
+
+ public LiftedConditional (Expression expr, Expression true_expr, Expression false_expr,
+ Location loc)
+ : base (expr, loc)
+ {
+ this.true_expr = true_expr;
+ this.false_expr = false_expr;
+ }
+
+ protected override Expression ResolveUnderlying (Expression unwrap, EmitContext ec)
+ {
+ return new Conditional (unwrap, true_expr, false_expr);
+ }
+ }
+
+ public class LiftedBinaryOperator : Binary
+ {
+ Expression underlying, null_value, bool_wrap;
+ Unwrap left_unwrap, right_unwrap;
+ bool is_equality, is_comparision, is_boolean;
+
+ public LiftedBinaryOperator (Binary.Operator op, Expression left, Expression right,
+ Location loc)
+ : base (op, left, right)
+ {
+ this.loc = loc;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ if ((Oper == Binary.Operator.LogicalAnd) ||
+ (Oper == Binary.Operator.LogicalOr)) {
+ Error_OperatorCannotBeApplied ();
+ return null;
+ }
+
+ if (TypeManager.IsNullableType (left.Type)) {
+ left = left_unwrap = Unwrap.Create (left, ec);
+ if (left == null)
+ return null;
+ }
+
+ if (TypeManager.IsNullableType (right.Type)) {
+ right = right_unwrap = Unwrap.Create (right, ec);
+ if (right == null)
+ return null;
+ }
+
+ if (((Oper == Binary.Operator.BitwiseAnd) || (Oper == Binary.Operator.BitwiseOr)) &&
+ ((left.Type == TypeManager.bool_type) && (right.Type == TypeManager.bool_type))) {
+ Expression empty = new EmptyExpression (TypeManager.bool_type);
+ bool_wrap = Wrap.Create (empty, ec);
+ null_value = new NullableLiteral (bool_wrap.Type, loc).Resolve (ec);
+
+ type = bool_wrap.Type;
+ is_boolean = true;
+ } else if ((Oper == Binary.Operator.Equality) || (Oper == Binary.Operator.Inequality)) {
+ if (!(left is NullLiteral) && !(right is NullLiteral)) {
+ underlying = new Binary (Oper, left, right).Resolve (ec);
+ if (underlying == null)
+ return null;
+ }
+
+ type = TypeManager.bool_type;
+ is_equality = true;
+ } else if ((Oper == Binary.Operator.LessThan) ||
+ (Oper == Binary.Operator.GreaterThan) ||
+ (Oper == Binary.Operator.LessThanOrEqual) ||
+ (Oper == Binary.Operator.GreaterThanOrEqual)) {
+ underlying = new Binary (Oper, left, right).Resolve (ec);
+ if (underlying == null)
+ return null;
+
+ type = TypeManager.bool_type;
+ is_comparision = true;
+ } else {
+ underlying = new Binary (Oper, left, right).Resolve (ec);
+ if (underlying == null)
+ return null;
+
+ underlying = Wrap.Create (underlying, ec);
+ if (underlying == null)
+ return null;
+
+ type = underlying.Type;
+ null_value = new NullableLiteral (type, loc).Resolve (ec);
+ }
+
+ eclass = ExprClass.Value;
+ return this;
+ }
+
+ void EmitBoolean (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+
+ Label left_is_null_label = ig.DefineLabel ();
+ Label right_is_null_label = ig.DefineLabel ();
+ Label is_null_label = ig.DefineLabel ();
+ Label wrap_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ if (left_unwrap != null) {
+ left_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, left_is_null_label);
+ }
+
+ left.Emit (ec);
+ ig.Emit (OpCodes.Dup);
+ if ((Oper == Binary.Operator.BitwiseOr) || (Oper == Binary.Operator.LogicalOr))
+ ig.Emit (OpCodes.Brtrue, wrap_label);
+ else
+ ig.Emit (OpCodes.Brfalse, wrap_label);
+
+ if (right_unwrap != null) {
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, right_is_null_label);
+ }
+
+ if ((Oper == Binary.Operator.LogicalAnd) || (Oper == Binary.Operator.LogicalOr))
+ ig.Emit (OpCodes.Pop);
+
+ right.Emit (ec);
+ if (Oper == Binary.Operator.BitwiseOr)
+ ig.Emit (OpCodes.Or);
+ else if (Oper == Binary.Operator.BitwiseAnd)
+ ig.Emit (OpCodes.And);
+ ig.Emit (OpCodes.Br, wrap_label);
+
+ ig.MarkLabel (left_is_null_label);
+ if (right_unwrap != null) {
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+ }
+
+ right.Emit (ec);
+ ig.Emit (OpCodes.Dup);
+ if ((Oper == Binary.Operator.BitwiseOr) || (Oper == Binary.Operator.LogicalOr))
+ ig.Emit (OpCodes.Brtrue, wrap_label);
+ else
+ ig.Emit (OpCodes.Brfalse, wrap_label);
+
+ ig.MarkLabel (right_is_null_label);
+ ig.Emit (OpCodes.Pop);
+ ig.MarkLabel (is_null_label);
+ null_value.Emit (ec);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (wrap_label);
+ ig.Emit (OpCodes.Nop);
+ bool_wrap.Emit (ec);
+ ig.Emit (OpCodes.Nop);
+
+ ig.MarkLabel (end_label);
+ }
+
+ void EmitEquality (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+
+ // Given 'X? x;' for any value type X: 'x != null' is the same as 'x.HasValue'
+ if (left is NullLiteral) {
+ if (right_unwrap == null)
+ throw new InternalErrorException ();
+ right_unwrap.EmitCheck (ec);
+ if (Oper == Binary.Operator.Equality) {
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Ceq);
+ }
+ return;
+ }
+
+ if (right is NullLiteral) {
+ if (left_unwrap == null)
+ throw new InternalErrorException ();
+ left_unwrap.EmitCheck (ec);
+ if (Oper == Binary.Operator.Equality) {
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Ceq);
+ }
+ return;
+ }
+
+ Label both_have_value_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ if (left_unwrap != null && right_unwrap != null) {
+ Label dissimilar_label = ig.DefineLabel ();
+
+ left_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Dup);
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Bne_Un, dissimilar_label);
+
+ ig.Emit (OpCodes.Brtrue, both_have_value_label);
+
+ // both are null
+ if (Oper == Binary.Operator.Equality)
+ ig.Emit (OpCodes.Ldc_I4_1);
+ else
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (dissimilar_label);
+ ig.Emit (OpCodes.Pop);
+ } else if (left_unwrap != null) {
+ left_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brtrue, both_have_value_label);
+ } else if (right_unwrap != null) {
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brtrue, both_have_value_label);
+ } else {
+ throw new InternalErrorException ("shouldn't get here");
+ }
+
+ // one is null while the other isn't
+ if (Oper == Binary.Operator.Equality)
+ ig.Emit (OpCodes.Ldc_I4_0);
+ else
+ ig.Emit (OpCodes.Ldc_I4_1);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (both_have_value_label);
+ underlying.Emit (ec);
+
+ ig.MarkLabel (end_label);
+ }
+
+ void EmitComparision (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+
+ Label is_null_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ if (left_unwrap != null) {
+ left_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+ }
+
+ if (right_unwrap != null) {
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+ }
+
+ underlying.Emit (ec);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (is_null_label);
+ ig.Emit (OpCodes.Ldc_I4_0);
+
+ ig.MarkLabel (end_label);
+ }
+
+ public override void EmitBranchable (EmitContext ec, Label target, bool onTrue)
+ {
+ Emit (ec);
+ ec.ig.Emit (onTrue ? OpCodes.Brtrue : OpCodes.Brfalse, target);
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ if (left_unwrap != null)
+ left_unwrap.Store (ec);
+ if (right_unwrap != null)
+ right_unwrap.Store (ec);
+
+ if (is_boolean) {
+ EmitBoolean (ec);
+ return;
+ } else if (is_equality) {
+ EmitEquality (ec);
+ return;
+ } else if (is_comparision) {
+ EmitComparision (ec);
+ return;
+ }
+
+ ILGenerator ig = ec.ig;
+
+ Label is_null_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ if (left_unwrap != null) {
+ left_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+ }
+
+ if (right_unwrap != null) {
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+ }
+
+ underlying.Emit (ec);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (is_null_label);
+ null_value.Emit (ec);
+
+ ig.MarkLabel (end_label);
+ }
+ }
+
+ public class OperatorTrueOrFalse : Expression
+ {
+ public readonly bool IsTrue;
+
+ Expression expr;
+ Unwrap unwrap;
+
+ public OperatorTrueOrFalse (Expression expr, bool is_true, Location loc)
+ {
+ this.IsTrue = is_true;
+ this.expr = expr;
+ this.loc = loc;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ unwrap = Unwrap.Create (expr, ec);
+ if (unwrap == null)
+ return null;
+
+ if (unwrap.Type != TypeManager.bool_type)
+ return null;
+
+ type = TypeManager.bool_type;
+ eclass = ExprClass.Value;
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+
+ Label is_null_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+
+ unwrap.Emit (ec);
+ if (!IsTrue) {
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Ceq);
+ }
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (is_null_label);
+ ig.Emit (OpCodes.Ldc_I4_0);
+
+ ig.MarkLabel (end_label);
+ }
+ }
+
+ public class NullCoalescingOperator : Expression
+ {
+ Expression left, right;
+ Expression expr;
+ Unwrap unwrap;
+
+ public NullCoalescingOperator (Expression left, Expression right, Location loc)
+ {
+ this.left = left;
+ this.right = right;
+ this.loc = loc;
+
+ eclass = ExprClass.Value;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ if (type != null)
+ return this;
+
+ left = left.Resolve (ec);
+ if (left == null)
+ return null;
+
+ right = right.Resolve (ec);
+ if (right == null)
+ return null;
+
+ Type ltype = left.Type, rtype = right.Type;
+
+ if (!TypeManager.IsNullableType (ltype) && ltype.IsValueType) {
+ Binary.Error_OperatorCannotBeApplied (loc, "??", ltype, rtype);
+ return null;
+ }
+
+ if (TypeManager.IsNullableType (ltype)) {
+ NullableInfo info = new NullableInfo (ltype);
+
+ unwrap = Unwrap.Create (left, ec);
+ if (unwrap == null)
+ return null;
+
+ expr = Convert.ImplicitConversion (ec, right, info.UnderlyingType, loc);
+ if (expr != null) {
+ left = unwrap;
+ type = expr.Type;
+ return this;
+ }
+ }
+
+ expr = Convert.ImplicitConversion (ec, right, ltype, loc);
+ if (expr != null) {
+ type = expr.Type;
+ return this;
+ }
+
+ Expression left_null = unwrap != null ? unwrap : left;
+ expr = Convert.ImplicitConversion (ec, left_null, rtype, loc);
+ if (expr != null) {
+ left = expr;
+ expr = right;
+ type = rtype;
+ return this;
+ }
+
+ Binary.Error_OperatorCannotBeApplied (loc, "??", ltype, rtype);
+ return null;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+
+ Label is_null_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ if (unwrap != null) {
+ unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+
+ left.Emit (ec);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (is_null_label);
+ expr.Emit (ec);
+
+ ig.MarkLabel (end_label);
+ } else {
+ left.Emit (ec);
+ ig.Emit (OpCodes.Dup);
+ ig.Emit (OpCodes.Brtrue, end_label);
+
+ ig.MarkLabel (is_null_label);
+
+ ig.Emit (OpCodes.Pop);
+ expr.Emit (ec);
+
+ ig.MarkLabel (end_label);
+ }
+ }
+ }
+
+ public class LiftedUnaryMutator : ExpressionStatement
+ {
+ public readonly UnaryMutator.Mode Mode;
+ Expression expr, null_value;
+ UnaryMutator underlying;
+ Unwrap unwrap;
+
+ public LiftedUnaryMutator (UnaryMutator.Mode mode, Expression expr, Location loc)
+ {
+ this.expr = expr;
+ this.Mode = mode;
+ this.loc = loc;
+
+ eclass = ExprClass.Value;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ expr = expr.Resolve (ec);
+ if (expr == null)
+ return null;
+
+ unwrap = Unwrap.Create (expr, ec);
+ if (unwrap == null)
+ return null;
+
+ underlying = (UnaryMutator) new UnaryMutator (Mode, unwrap, loc).Resolve (ec);
+ if (underlying == null)
+ return null;
+
+ null_value = new NullableLiteral (expr.Type, loc).Resolve (ec);
+ if (null_value == null)
+ return null;
+
+ type = expr.Type;
+ return this;
+ }
+
+ void DoEmit (EmitContext ec, bool is_expr)
+ {
+ ILGenerator ig = ec.ig;
+ Label is_null_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Brfalse, is_null_label);
+
+ if (is_expr)
+ underlying.Emit (ec);
+ else
+ underlying.EmitStatement (ec);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (is_null_label);
+ if (is_expr)
+ null_value.Emit (ec);
+
+ ig.MarkLabel (end_label);
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ DoEmit (ec, true);
+ }
+
+ public override void EmitStatement (EmitContext ec)
+ {
+ DoEmit (ec, false);
+ }