| public static IsNullableType ( System.TypeSpec t ) : bool | ||
| t | System.TypeSpec | |
| Résultat | bool | |
public override Constant ConvertExplicitly(bool inCheckedContext, Type targetType)
{
if (targetType.IsPointer)
{
if (type == TypeManager.null_type || this is NullPointer)
{
return(new EmptyConstantCast(new NullPointer(loc), targetType));
}
return(null);
}
// Exlude internal compiler types
if (targetType == InternalType.AnonymousMethod)
{
return(null);
}
if (type != TypeManager.null_type && !Convert.ImplicitStandardConversionExists(this, targetType))
{
return(null);
}
if (TypeManager.IsReferenceType(targetType))
{
return(new NullLiteral(targetType, loc));
}
if (TypeManager.IsNullableType(targetType))
{
return(Nullable.LiftedNull.Create(targetType, loc));
}
return(null);
}
public override Constant ConvertExplicitly(bool inCheckedContext, Type targetType)
{
if (targetType.IsPointer)
{
return(new EmptyConstantCast(new NullPointer(loc), targetType));
}
// Exlude internal compiler types
if (targetType == TypeManager.anonymous_method_type)
{
return(null);
}
if (TypeManager.IsReferenceType(targetType))
{
return(new EmptyConstantCast(this, targetType));
}
if (TypeManager.IsNullableType(targetType))
{
return(Nullable.LiftedNull.Create(targetType, loc));
}
return(null);
}
public override Expression DoResolve(ResolveContext ec)
{
constructor_method = Delegate.GetConstructor(ec.Compiler, ec.CurrentType, type);
MethodInfo invoke_method = Delegate.GetInvokeMethod(ec.Compiler, ec.CurrentType, type);
method_group.DelegateType = type;
method_group.CustomErrorHandler = this;
Arguments arguments = CreateDelegateMethodArguments(TypeManager.GetParameterData(invoke_method), loc);
method_group = method_group.OverloadResolve(ec, ref arguments, false, loc);
if (method_group == null)
{
return(null);
}
delegate_method = (MethodInfo)method_group;
if (TypeManager.IsNullableType(delegate_method.DeclaringType))
{
ec.Report.Error(1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
TypeManager.GetFullNameSignature(delegate_method));
return(null);
}
Invocation.IsSpecialMethodInvocation(ec, delegate_method, loc);
ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
if (emg != null)
{
delegate_instance_expression = emg.ExtensionExpression;
Type e_type = delegate_instance_expression.Type;
if (TypeManager.IsValueType(e_type))
{
ec.Report.Error(1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
TypeManager.CSharpSignature(delegate_method), TypeManager.CSharpName(e_type));
}
}
Type rt = TypeManager.TypeToCoreType(delegate_method.ReturnType);
Expression ret_expr = new TypeExpression(rt, loc);
if (!Delegate.IsTypeCovariant(ret_expr, (TypeManager.TypeToCoreType(invoke_method.ReturnType))))
{
Error_ConversionFailed(ec, delegate_method, ret_expr);
}
if (Invocation.IsMethodExcluded(delegate_method, loc))
{
ec.Report.SymbolRelatedToPreviousError(delegate_method);
MethodOrOperator m = TypeManager.GetMethod(delegate_method) as MethodOrOperator;
if (m != null && m.IsPartialDefinition)
{
ec.Report.Error(762, loc, "Cannot create delegate from partial method declaration `{0}'",
TypeManager.CSharpSignature(delegate_method));
}
else
{
ec.Report.Error(1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
TypeManager.CSharpSignature(delegate_method));
}
}
DoResolveInstanceExpression(ec);
eclass = ExprClass.Value;
return(this);
}
public void Resolve(ResolveContext rc, Parameter p)
{
var expr = Resolve(rc);
if (expr == null)
{
return;
}
expr = Child;
if (!(expr is Constant || expr is DefaultValueExpression || (expr is New && ((New)expr).IsDefaultStruct)))
{
rc.Report.Error(1736, Location,
"The expression being assigned to optional parameter `{0}' must be a constant or default value",
p.Name);
return;
}
var parameter_type = p.Type;
if (type == parameter_type)
{
return;
}
var res = Convert.ImplicitConversionStandard(rc, expr, parameter_type, Location);
if (res != null)
{
if (TypeManager.IsNullableType(parameter_type) && res is Nullable.Wrap)
{
Nullable.Wrap wrap = (Nullable.Wrap)res;
res = wrap.Child;
if (!(res is Constant))
{
rc.Report.Error(1770, Location,
"The expression being assigned to nullable optional parameter `{0}' must be default value",
p.Name);
return;
}
}
if (!expr.IsNull && TypeManager.IsReferenceType(parameter_type) && parameter_type != TypeManager.string_type)
{
rc.Report.Error(1763, Location,
"Optional parameter `{0}' of type `{1}' can only be initialized with `null'",
p.Name, parameter_type.GetSignatureForError());
return;
}
this.expr = res;
return;
}
rc.Report.Error(1750, Location,
"Optional parameter expression of type `{0}' cannot be converted to parameter type `{1}'",
type.GetSignatureForError(), parameter_type.GetSignatureForError());
}
// <summary>
// Resolve is used in method definitions
// </summary>
public virtual Type Resolve(IMemberContext rc)
{
if (parameter_type != null)
{
return(parameter_type);
}
if (attributes != null)
{
attributes.AttachTo(this, rc);
}
TypeExpr texpr = TypeName.ResolveAsTypeTerminal(rc, false);
if (texpr == null)
{
return(null);
}
parameter_type = texpr.Type;
// Ignore all checks for dummy members
AbstractPropertyEventMethod pem = rc as AbstractPropertyEventMethod;
if (pem != null && pem.IsDummy)
{
return(parameter_type);
}
if (default_expr != null)
{
ResolveContext ec = new ResolveContext(rc);
default_expr = default_expr.Resolve(ec);
if (default_expr != null)
{
Constant value = default_expr as Constant;
if (value == null)
{
if (default_expr != null)
{
bool is_valid = false;
if (default_expr is DefaultValueExpression)
{
is_valid = true;
}
else if (default_expr is New && ((New)default_expr).IsDefaultValueType)
{
is_valid = TypeManager.IsEqual(parameter_type, default_expr.Type) ||
(TypeManager.IsNullableType(parameter_type) &&
Convert.ImplicitNulableConversion(ec, default_expr, parameter_type) != EmptyExpression.Null);
}
else
{
rc.Compiler.Report.Error(1736, default_expr.Location,
"The expression being assigned to optional parameter `{0}' must be a constant or default value",
Name);
is_valid = true;
}
if (!is_valid)
{
default_expr = null;
ec.Compiler.Report.Error(1763, Location,
"Optional parameter `{0}' of type `{1}' can only be initialized with `null'",
Name, GetSignatureForError());
}
}
}
else
{
Constant c = value.ConvertImplicitly(parameter_type);
if (c == null)
{
if (parameter_type == TypeManager.object_type)
{
rc.Compiler.Report.Error(1763, Location,
"Optional parameter `{0}' of type `{1}' can only be initialized with `null'",
Name, GetSignatureForError());
}
else
{
rc.Compiler.Report.Error(1750, Location,
"Optional parameter value `{0}' cannot be converted to parameter type `{1}'",
value.GetValue(), GetSignatureForError());
}
default_expr = null;
}
}
}
}
if ((modFlags & Parameter.Modifier.ISBYREF) != 0 &&
TypeManager.IsSpecialType(parameter_type))
{
rc.Compiler.Report.Error(1601, Location, "Method or delegate parameter cannot be of type `{0}'",
GetSignatureForError());
return(null);
}
TypeManager.CheckTypeVariance(parameter_type,
(modFlags & Parameter.Modifier.ISBYREF) != 0 ? Variance.None : Variance.Contravariant,
rc);
if (TypeManager.IsGenericParameter(parameter_type))
{
return(parameter_type);
}
if ((parameter_type.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute)
{
rc.Compiler.Report.Error(721, Location, "`{0}': static types cannot be used as parameters",
texpr.GetSignatureForError());
return(parameter_type);
}
if ((modFlags & Modifier.This) != 0 && (parameter_type.IsPointer || TypeManager.IsDynamicType(parameter_type)))
{
rc.Compiler.Report.Error(1103, Location, "The extension method cannot be of type `{0}'",
TypeManager.CSharpName(parameter_type));
}
return(parameter_type);
}
protected override Expression DoResolve(ResolveContext ec)
{
constructor_method = Delegate.GetConstructor(ec.Compiler, ec.CurrentType, type);
var invoke_method = Delegate.GetInvokeMethod(ec.Compiler, type);
Arguments arguments = CreateDelegateMethodArguments(invoke_method.Parameters, invoke_method.Parameters.Types, loc);
method_group = method_group.OverloadResolve(ec, ref arguments, this, OverloadResolver.Restrictions.CovariantDelegate);
if (method_group == null)
{
return(null);
}
var delegate_method = method_group.BestCandidate;
if (TypeManager.IsNullableType(delegate_method.DeclaringType))
{
ec.Report.Error(1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
delegate_method.GetSignatureForError());
return(null);
}
Invocation.IsSpecialMethodInvocation(ec, delegate_method, loc);
ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
if (emg != null)
{
method_group.InstanceExpression = emg.ExtensionExpression;
TypeSpec e_type = emg.ExtensionExpression.Type;
if (TypeManager.IsValueType(e_type))
{
ec.Report.Error(1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
delegate_method.GetSignatureForError(), TypeManager.CSharpName(e_type));
}
}
TypeSpec rt = delegate_method.ReturnType;
Expression ret_expr = new TypeExpression(rt, loc);
if (!Delegate.IsTypeCovariant(ret_expr, invoke_method.ReturnType))
{
Error_ConversionFailed(ec, delegate_method, ret_expr);
}
if (delegate_method.IsConditionallyExcluded(loc))
{
ec.Report.SymbolRelatedToPreviousError(delegate_method);
MethodOrOperator m = delegate_method.MemberDefinition as MethodOrOperator;
if (m != null && m.IsPartialDefinition)
{
ec.Report.Error(762, loc, "Cannot create delegate from partial method declaration `{0}'",
delegate_method.GetSignatureForError());
}
else
{
ec.Report.Error(1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
TypeManager.CSharpSignature(delegate_method));
}
}
var expr = method_group.InstanceExpression;
if (expr != null && (expr.Type.IsGenericParameter || !TypeManager.IsReferenceType(expr.Type)))
{
method_group.InstanceExpression = new BoxedCast(expr, TypeManager.object_type);
}
eclass = ExprClass.Value;
return(this);
}
