+
+ 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 (EmitContext ec)
+ {
+ TypeArguments args = new TypeArguments (loc);
+ args.Add (underlying);
+
+ ConstructedType ctype = new ConstructedType (TypeManager.generic_nullable_type, args, loc);
+ return ctype.ResolveAsTypeTerminal (ec);
+ }
+ }
+
+ public partial class TypeManager
+ {
+ //
+ // A list of core types that the compiler requires or uses
+ //
+ static public Type new_constraint_attr_type;
+ static public Type activator_type;
+ static public Type generic_ienumerator_type;
+ static public Type generic_ienumerable_type;
+ static public Type generic_nullable_type;
+
+ // <remarks>
+ // Tracks the generic parameters.
+ // </remarks>
+ static PtrHashtable builder_to_type_param;
+
+ //
+ // These methods are called by code generated by the compiler
+ //
+ static public MethodInfo activator_create_instance;
+
+ static void InitGenerics ()
+ {
+ builder_to_type_param = new PtrHashtable ();
+ }
+
+ static void CleanUpGenerics ()
+ {
+ builder_to_type_param = null;
+ }
+
+ static void InitGenericCoreTypes ()
+ {
+ activator_type = CoreLookupType ("System.Activator");
+ new_constraint_attr_type = CoreLookupType (
+ "System.Runtime.CompilerServices.NewConstraintAttribute");
+
+ 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
+ Type [] type_arg = { type_type };
+ activator_create_instance = GetMethod (
+ activator_type, "CreateInstance", type_arg);
+ }
+
+ static Type CoreLookupType (string name, int arity)
+ {
+ return CoreLookupType (MemberName.MakeName (name, arity));
+ }
+
+ public static void AddTypeParameter (Type t, TypeParameter tparam)
+ {
+ if (!builder_to_type_param.Contains (t))
+ builder_to_type_param.Add (t, tparam);
+ }
+
+ public static TypeContainer LookupGenericTypeContainer (Type t)
+ {
+ while (t.IsGenericInstance)
+ t = t.GetGenericTypeDefinition ();
+
+ return LookupTypeContainer (t);
+ }
+
+ public static TypeParameter LookupTypeParameter (Type t)
+ {
+ return (TypeParameter) builder_to_type_param [t];
+ }
+
+ public static GenericConstraints GetTypeParameterConstraints (Type t)
+ {
+ if (!t.IsGenericParameter)
+ throw new InvalidOperationException ();
+
+ TypeParameter tparam = LookupTypeParameter (t);
+ if (tparam != null)
+ return tparam.GenericConstraints;
+
+ return new ReflectionConstraints (t);
+ }
+
+ public static bool IsGeneric (Type t)
+ {
+ DeclSpace ds = (DeclSpace) builder_to_declspace [t];
+
+ return ds.IsGeneric;
+ }
+
+ public static bool HasGenericArguments (Type t)
+ {
+ return GetNumberOfTypeArguments (t) > 0;
+ }
+
+ public static int GetNumberOfTypeArguments (Type t)
+ {
+ DeclSpace tc = LookupDeclSpace (t);
+ if (tc != null)
+ return tc.IsGeneric ? tc.CountTypeParameters : 0;
+ else
+ return t.HasGenericArguments ? t.GetGenericArguments ().Length : 0;
+ }
+
+ public static Type[] GetTypeArguments (Type t)
+ {
+ DeclSpace tc = LookupDeclSpace (t);
+ if (tc != null) {
+ if (!tc.IsGeneric)
+ return Type.EmptyTypes;
+
+ TypeParameter[] tparam = tc.TypeParameters;
+ Type[] ret = new Type [tparam.Length];
+ for (int i = 0; i < tparam.Length; i++) {
+ ret [i] = tparam [i].Type;
+ if (ret [i] == null)
+ throw new InternalErrorException ();
+ }
+
+ return ret;
+ } else
+ return t.GetGenericArguments ();
+ }
+
+ //
+ // Whether `array' is an array of T and `enumerator' is `IEnumerable<T>'.
+ // For instance "string[]" -> "IEnumerable<string>".
+ //
+ public static bool IsIEnumerable (Type array, Type enumerator)
+ {
+ if (!array.IsArray || !enumerator.IsGenericInstance)
+ return false;
+
+ if (enumerator.GetGenericTypeDefinition () != generic_ienumerable_type)
+ return false;
+
+ Type[] args = GetTypeArguments (enumerator);
+ return args [0] == GetElementType (array);
+ }
+
+ public static bool IsEqual (Type a, Type b)
+ {
+ if (a.Equals (b))
+ return true;
+
+ if ((a is TypeBuilder) && a.IsGenericTypeDefinition && b.IsGenericInstance) {
+ //
+ // `a' is a generic type definition's TypeBuilder and `b' is a
+ // generic instance of the same type.
+ //
+ // Example:
+ //
+ // class Stack<T>
+ // {
+ // void Test (Stack<T> stack) { }
+ // }
+ //
+ // The first argument of `Test' will be the generic instance
+ // "Stack<!0>" - which is the same type than the "Stack" TypeBuilder.
+ //
+ //
+ // We hit this via Closure.Filter() for gen-82.cs.
+ //
+ if (a != b.GetGenericTypeDefinition ())
+ return false;
+
+ Type[] aparams = a.GetGenericArguments ();
+ Type[] bparams = b.GetGenericArguments ();
+
+ if (aparams.Length != bparams.Length)
+ return false;
+
+ for (int i = 0; i < aparams.Length; i++)
+ if (!IsEqual (aparams [i], bparams [i]))
+ return false;
+
+ return true;
+ }
+
+ if ((b is TypeBuilder) && b.IsGenericTypeDefinition && a.IsGenericInstance)
+ return IsEqual (b, a);
+
+ if (a.IsGenericParameter && b.IsGenericParameter) {
+ if ((a.DeclaringMethod == null) || (b.DeclaringMethod == null))
+ return false;
+ return a.GenericParameterPosition == b.GenericParameterPosition;
+ }
+
+ if (a.IsArray && b.IsArray) {
+ if (a.GetArrayRank () != b.GetArrayRank ())
+ return false;
+ return IsEqual (a.GetElementType (), b.GetElementType ());
+ }
+
+ if (a.IsGenericInstance && b.IsGenericInstance) {
+ if (a.GetGenericTypeDefinition () != b.GetGenericTypeDefinition ())
+ return false;
+
+ Type[] aargs = a.GetGenericArguments ();
+ Type[] bargs = b.GetGenericArguments ();
+
+ if (aargs.Length != bargs.Length)
+ return false;
+
+ for (int i = 0; i < aargs.Length; i++) {
+ if (!IsEqual (aargs [i], bargs [i]))
+ return false;
+ }
+
+ return true;
+ }
+
+ return false;
+ }
+
+ public static bool MayBecomeEqualGenericTypes (Type a, Type b, Type[] class_infered, Type[] method_infered)
+ {
+ 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.IsGenericInstance) {
+ int pos = a.GenericParameterPosition;
+ Type[] args = a.DeclaringMethod != null ? method_infered : class_infered;
+ 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_infered, method_infered);
+
+ //
+ // 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.IsGenericInstance || b.IsGenericInstance)
+ return MayBecomeEqualGenericInstances (a, b, class_infered, method_infered);
+
+ //
+ // 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_infered, method_infered);
+ }
+
+ //
+ // 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_infered, Type[] method_infered)
+ {
+ if (!a.IsGenericInstance || !b.IsGenericInstance)
+ return false;
+ if (a.GetGenericTypeDefinition () != b.GetGenericTypeDefinition ())
+ return false;
+
+ return MayBecomeEqualGenericInstances (
+ GetTypeArguments (a), GetTypeArguments (b), class_infered, method_infered);
+ }
+
+ public static bool MayBecomeEqualGenericInstances (Type[] aargs, Type[] bargs,
+ Type[] class_infered, Type[] method_infered)
+ {
+ if (aargs.Length != bargs.Length)
+ return false;
+
+ for (int i = 0; i < aargs.Length; i++) {
+ if (!MayBecomeEqualGenericTypes (aargs [i], bargs [i], class_infered, method_infered))
+ return false;
+ }
+
+ return true;
+ }
+
+ public static bool IsEqualGenericInstance (Type type, Type parent)
+ {
+ int tcount = GetNumberOfTypeArguments (type);
+ int pcount = GetNumberOfTypeArguments (parent);
+
+ if (type.IsGenericInstance)
+ type = type.GetGenericTypeDefinition ();
+ if (parent.IsGenericInstance)
+ parent = parent.GetGenericTypeDefinition ();
+
+ if (tcount != pcount)
+ return false;
+
+ return type.Equals (parent);
+ }
+
+ static public bool IsGenericMethod (MethodBase mb)
+ {
+ if (mb.DeclaringType is TypeBuilder) {
+ IMethodData method = (IMethodData) builder_to_method [mb];
+ if (method == null)
+ return false;
+
+ return method.GenericMethod != null;
+ }
+
+ return mb.IsGenericMethodDefinition;
+ }
+
+ //
+ // Type inference.
+ //
+
+ static bool InferType (Type pt, Type at, Type[] infered)
+ {
+ if (pt.IsGenericParameter && (pt.DeclaringMethod != null)) {
+ int pos = pt.GenericParameterPosition;
+
+ if (infered [pos] == null) {
+ Type check = at;
+ while (check.IsArray)
+ check = check.GetElementType ();
+
+ if (pt == check)
+ return false;
+
+ infered [pos] = at;
+ return true;
+ }
+
+ if (infered [pos] != at)
+ return false;
+
+ return true;
+ }
+
+ if (!pt.ContainsGenericParameters) {
+ if (at.ContainsGenericParameters)
+ return InferType (at, pt, infered);
+ else
+ return true;
+ }
+
+ if (at.IsArray) {
+ if (!pt.IsArray ||
+ (at.GetArrayRank () != pt.GetArrayRank ()))
+ return false;
+
+ return InferType (pt.GetElementType (), at.GetElementType (), infered);
+ }
+
+ if (pt.IsArray) {
+ if (!at.IsArray ||
+ (pt.GetArrayRank () != at.GetArrayRank ()))
+ return false;
+
+ return InferType (pt.GetElementType (), at.GetElementType (), infered);
+ }
+
+ if (pt.IsByRef && at.IsByRef)
+ return InferType (pt.GetElementType (), at.GetElementType (), infered);
+ ArrayList list = new ArrayList ();
+ if (at.IsGenericInstance)
+ list.Add (at);
+ for (Type bt = at.BaseType; bt != null; bt = bt.BaseType)
+ list.Add (bt);
+
+ list.AddRange (TypeManager.GetInterfaces (at));
+
+ bool found_one = false;
+
+ foreach (Type type in list) {
+ if (!type.IsGenericInstance)
+ continue;
+
+ Type[] infered_types = new Type [infered.Length];
+
+ if (!InferGenericInstance (pt, type, infered_types))
+ continue;
+
+ for (int i = 0; i < infered_types.Length; i++) {
+ if (infered [i] == null) {
+ infered [i] = infered_types [i];
+ continue;
+ }
+
+ if (infered [i] != infered_types [i])
+ return false;
+ }
+
+ found_one = true;
+ }
+
+ return found_one;
+ }
+
+ static bool InferGenericInstance (Type pt, Type at, Type[] infered_types)
+ {
+ Type[] at_args = at.GetGenericArguments ();
+ Type[] pt_args = pt.GetGenericArguments ();
+
+ if (at_args.Length != pt_args.Length)
+ return false;
+
+ for (int i = 0; i < at_args.Length; i++) {
+ if (!InferType (pt_args [i], at_args [i], infered_types))
+ return false;
+ }
+
+ for (int i = 0; i < infered_types.Length; i++) {
+ if (infered_types [i] == null)
+ return false;
+ }
+
+ return true;
+ }
+
+ public static bool InferParamsTypeArguments (EmitContext ec, ArrayList arguments,
+ ref MethodBase method)
+ {
+ if ((arguments == null) || !TypeManager.IsGenericMethod (method))
+ return true;
+
+ int arg_count;
+
+ if (arguments == null)
+ arg_count = 0;
+ else
+ arg_count = arguments.Count;
+
+ ParameterData pd = TypeManager.GetParameterData (method);
+
+ int pd_count = pd.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;
+
+ if (pd_count == 1 && arg_count == 0)
+ return true;
+
+ Type[] method_args = method.GetGenericArguments ();
+ Type[] infered_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 (!InferType (pt, at, infered_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 (!InferType (element_type, a.Type, infered_types))
+ return false;
+ }
+
+ for (int i = 0; i < infered_types.Length; i++)
+ if (infered_types [i] == null)
+ return false;
+
+ method = method.BindGenericParameters (infered_types);
+ return true;
+ }
+
+ public static bool InferTypeArguments (Type[] param_types, Type[] arg_types, Type[] infered_types)
+ {
+ if (infered_types == null)
+ return false;
+
+ for (int i = 0; i < arg_types.Length; i++) {
+ if (arg_types [i] == null)
+ continue;
+
+ if (!InferType (param_types [i], arg_types [i], infered_types))
+ return false;
+ }
+
+ for (int i = 0; i < infered_types.Length; i++)
+ if (infered_types [i] == null)
+ return false;
+
+ return true;
+ }
+
+ public static bool InferTypeArguments (EmitContext ec, ArrayList arguments,
+ ref MethodBase method)
+ {
+ if (!TypeManager.IsGenericMethod (method))
+ return true;
+
+ int arg_count;
+ if (arguments != null)
+ arg_count = arguments.Count;
+ else
+ arg_count = 0;
+
+ ParameterData pd = TypeManager.GetParameterData (method);
+ if (arg_count != pd.Count)
+ return false;
+
+ Type[] method_args = method.GetGenericArguments ();
+
+ bool is_open = false;
+ for (int i = 0; i < method_args.Length; i++) {
+ if (method_args [i].IsGenericParameter) {
+ is_open = true;
+ break;
+ }
+ }
+ if (!is_open)
+ return true;
+
+ Type[] infered_types = new Type [method_args.Length];
+
+ Type[] param_types = new Type [pd.Count];
+ Type[] arg_types = new Type [pd.Count];
+
+ for (int i = 0; i < arg_count; i++) {
+ param_types [i] = pd.ParameterType (i);
+
+ Argument a = (Argument) arguments [i];
+ if ((a.Expr is NullLiteral) || (a.Expr is MethodGroupExpr) ||
+ (a.Expr is AnonymousMethod))
+ continue;
+
+ arg_types [i] = a.Type;
+ }
+
+ if (!InferTypeArguments (param_types, arg_types, infered_types))
+ return false;
+
+ method = method.BindGenericParameters (infered_types);
+ return true;
+ }
+
+ public static bool InferTypeArguments (EmitContext ec, ParameterData apd,
+ ref MethodBase method)
+ {
+ if (!TypeManager.IsGenericMethod (method))
+ return true;
+
+ ParameterData pd = TypeManager.GetParameterData (method);
+ if (apd.Count != pd.Count)
+ return false;
+
+ Type[] method_args = method.GetGenericArguments ();
+ Type[] infered_types = new Type [method_args.Length];
+
+ Type[] param_types = new Type [pd.Count];
+ Type[] arg_types = new Type [pd.Count];
+
+ for (int i = 0; i < apd.Count; i++) {
+ param_types [i] = pd.ParameterType (i);
+ arg_types [i] = apd.ParameterType (i);
+ }
+
+ if (!InferTypeArguments (param_types, arg_types, infered_types))
+ return false;
+
+ method = method.BindGenericParameters (infered_types);
+ return true;
+ }
+
+ public static bool IsNullableType (Type t)
+ {
+ if (!t.IsGenericInstance)
+ return false;
+
+ Type gt = t.GetGenericTypeDefinition ();
+ return gt == generic_nullable_type;
+ }
+ }
+
+ public abstract class Nullable
+ {
+ protected 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 = type.GetProperty ("HasValue");
+ PropertyInfo value_pi = type.GetProperty ("Value");
+
+ HasValue = has_value_pi.GetGetMethod (false);
+ Value = value_pi.GetGetMethod (false);
+ Constructor = type.GetConstructor (new Type[] { UnderlyingType });
+ }
+ }
+
+ protected class Unwrap : Expression, IMemoryLocation, IAssignMethod
+ {
+ Expression expr;
+ NullableInfo info;
+
+ LocalTemporary temp;
+ bool has_temp;
+
+ public Unwrap (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;
+
+ if (!(expr is IMemoryLocation))
+ temp = new LocalTemporary (ec, 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);
+ }
+
+ 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)
+ {
+ source.Emit (ec);
+ ec.ig.Emit (OpCodes.Newobj, info.Constructor);
+
+ if (leave_copy)
+ ec.ig.Emit (OpCodes.Dup);
+
+ Expression empty = new EmptyExpression (expr.Type);
+ ((IAssignMethod) expr).EmitAssign (ec, empty, false, prepare_for_load);
+ }
+ }
+
+ protected class Wrap : Expression
+ {
+ Expression expr;
+ NullableInfo info;
+
+ public Wrap (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;
+
+ TypeExpr target_type = new NullableType (expr.Type, loc);
+ target_type = target_type.ResolveAsTypeTerminal (ec);
+ 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 : Expression, IMemoryLocation {
+ public NullableLiteral (Type target_type, Location loc)
+ {
+ this.type = target_type;
+ this.loc = loc;
+
+ eclass = ExprClass.Value;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ LocalTemporary value_target = new LocalTemporary (ec, 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 (ec, 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) new Unwrap (expr, loc).Resolve (ec);
+ if (unwrap == null)
+ return null;
+
+ underlying = ResolveUnderlying (unwrap, ec);
+ if (underlying == null)
+ return null;
+
+ wrap = new Wrap (underlying, loc).Resolve (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, loc);
+ }
+ }
+
+ public class LiftedBinaryOperator : Expression
+ {
+ public readonly Binary.Operator Oper;
+
+ Expression left, right, 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)
+ {
+ this.Oper = op;
+ this.left = left;
+ this.right = right;
+ this.loc = loc;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ if (TypeManager.IsNullableType (left.Type)) {
+ left_unwrap = new Unwrap (left, loc);
+ left = left_unwrap.Resolve (ec);
+ if (left == null)
+ return null;
+ }
+
+ if (TypeManager.IsNullableType (right.Type)) {
+ right_unwrap = new Unwrap (right, loc);
+ right = right_unwrap.Resolve (ec);
+ if (right == null)
+ return null;
+ }
+
+ if (((Oper == Binary.Operator.BitwiseAnd) || (Oper == Binary.Operator.BitwiseOr) ||
+ (Oper == Binary.Operator.LogicalAnd) || (Oper == Binary.Operator.LogicalOr)) &&
+ ((left.Type == TypeManager.bool_type) && (right.Type == TypeManager.bool_type))) {
+ Expression empty = new EmptyExpression (TypeManager.bool_type);
+ bool_wrap = new Wrap (empty, loc).Resolve (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, loc).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, loc).Resolve (ec);
+ if (underlying == null)
+ return null;
+
+ type = TypeManager.bool_type;
+ is_comparision = true;
+ } else {
+ underlying = new Binary (Oper, left, right, loc).Resolve (ec);
+ if (underlying == null)
+ return null;
+
+ underlying = new Wrap (underlying, loc).Resolve (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;
+
+ Label left_not_null_label = ig.DefineLabel ();
+ Label false_label = ig.DefineLabel ();
+ Label true_label = ig.DefineLabel ();
+ Label end_label = ig.DefineLabel ();
+
+ if (left_unwrap != null) {
+ left_unwrap.EmitCheck (ec);
+ if (right is NullLiteral) {
+ if (Oper == Binary.Operator.Equality)
+ ig.Emit (OpCodes.Brfalse, true_label);
+ else
+ ig.Emit (OpCodes.Brfalse, false_label);
+ } else if (right_unwrap != null) {
+ ig.Emit (OpCodes.Dup);
+ ig.Emit (OpCodes.Brtrue, left_not_null_label);
+ right_unwrap.EmitCheck (ec);
+ ig.Emit (OpCodes.Ceq);
+ if (Oper == Binary.Operator.Inequality) {
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Ceq);
+ }
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (left_not_null_label);
+ ig.Emit (OpCodes.Pop);
+ } else {
+ if (Oper == Binary.Operator.Equality)
+ ig.Emit (OpCodes.Brfalse, false_label);
+ else
+ ig.Emit (OpCodes.Brfalse, true_label);
+ }
+ }
+
+ if (right_unwrap != null) {
+ right_unwrap.EmitCheck (ec);
+ if (left is NullLiteral) {
+ if (Oper == Binary.Operator.Equality)
+ ig.Emit (OpCodes.Brfalse, true_label);
+ else
+ ig.Emit (OpCodes.Brfalse, false_label);
+ } else {
+ if (Oper == Binary.Operator.Equality)
+ ig.Emit (OpCodes.Brfalse, false_label);
+ else
+ ig.Emit (OpCodes.Brfalse, true_label);
+ }
+ }
+
+ bool left_is_null = left is NullLiteral;
+ bool right_is_null = right is NullLiteral;
+ if (left_is_null || right_is_null) {
+ if (((Oper == Binary.Operator.Equality) && (left_is_null == right_is_null)) ||
+ ((Oper == Binary.Operator.Inequality) && (left_is_null != right_is_null)))
+ ig.Emit (OpCodes.Br, true_label);
+ else
+ ig.Emit (OpCodes.Br, false_label);
+ } else {
+ underlying.Emit (ec);
+ ig.Emit (OpCodes.Br, end_label);
+ }
+
+ ig.MarkLabel (false_label);
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Br, end_label);
+
+ ig.MarkLabel (true_label);
+ ig.Emit (OpCodes.Ldc_I4_1);
+
+ 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 Emit (EmitContext 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 = new Unwrap (expr, loc);
+ expr = unwrap.Resolve (ec);
+ if (expr == 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) new Unwrap (left, loc).Resolve (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;
+ }
+
+ if (unwrap != null) {
+ expr = Convert.ImplicitConversion (ec, unwrap, rtype, loc);
+ if (expr != null) {
+ left = expr;
+ expr = right;
+ type = expr.Type;
+ 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) new Unwrap (expr, loc).Resolve (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);
+ }
+ }
+ }