public static Expression ImplicitTypeParameterConversion (Expression expr, TypeParameterSpec expr_type, TypeSpec target_type)
{
//
// From T to a type parameter U, provided T depends on U
//
if (target_type.IsGenericParameter) {
if (expr_type.TypeArguments != null && expr_type.HasDependencyOn (target_type)) {
if (expr == null)
return EmptyExpression.Null;
if (expr_type.IsReferenceType && !((TypeParameterSpec) target_type).IsReferenceType)
return new BoxedCast (expr, target_type);
return new ClassCast (expr, target_type);
}
return null;
}
//
// LAMESPEC: From T to dynamic type because it's like T to object
//
if (target_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
if (expr == null)
return EmptyExpression.Null;
if (expr_type.IsReferenceType)
return new ClassCast (expr, target_type);
return new BoxedCast (expr, target_type);
}
//
// From T to its effective base class C
// From T to any base class of C (it cannot contain dynamic or be of dynamic type)
// From T to any interface implemented by C
//
var base_type = expr_type.GetEffectiveBase ();
if (base_type == target_type || TypeSpec.IsBaseClass (base_type, target_type, false) || base_type.ImplementsInterface (target_type, true)) {
if (expr == null)
return EmptyExpression.Null;
if (expr_type.IsReferenceType)
return new ClassCast (expr, target_type);
return new BoxedCast (expr, target_type);
}
if (target_type.IsInterface && expr_type.IsConvertibleToInterface (target_type)) {
if (expr == null)
return EmptyExpression.Null;
if (expr_type.IsReferenceType)
return new ClassCast (expr, target_type);
return new BoxedCast (expr, target_type);
}
return null;
}
static Expression ExplicitTypeParameterConversionToT (Expression source, TypeSpec source_type, TypeParameterSpec target_type)
{
//
// From the effective base class C of T to T and from any base class of C to T
//
var effective = target_type.GetEffectiveBase ();
if (TypeSpecComparer.IsEqual (effective, source_type) || TypeSpec.IsBaseClass (effective, source_type, false))
return source == null ? EmptyExpression.Null : new ClassCast (source, target_type);
return null;
}
TypeParameterSpec CreateTypeParameter (MetaType type, TypeSpec declaringType)
{
Variance variance;
switch (type.GenericParameterAttributes & GenericParameterAttributes.VarianceMask) {
case GenericParameterAttributes.Covariant:
variance = Variance.Covariant;
break;
case GenericParameterAttributes.Contravariant:
variance = Variance.Contravariant;
break;
default:
variance = Variance.None;
break;
}
SpecialConstraint special = SpecialConstraint.None;
var import_special = type.GenericParameterAttributes & GenericParameterAttributes.SpecialConstraintMask;
if ((import_special & GenericParameterAttributes.NotNullableValueTypeConstraint) != 0) {
special |= SpecialConstraint.Struct;
} else if ((import_special & GenericParameterAttributes.DefaultConstructorConstraint) != 0) {
special = SpecialConstraint.Constructor;
}
if ((import_special & GenericParameterAttributes.ReferenceTypeConstraint) != 0) {
special |= SpecialConstraint.Class;
}
TypeParameterSpec spec;
var def = new ImportedTypeParameterDefinition (type, this);
if (type.DeclaringMethod != null) {
spec = new TypeParameterSpec (type.GenericParameterPosition, def, special, variance, type);
} else {
spec = new TypeParameterSpec (declaringType, type.GenericParameterPosition, def, special, variance, type);
}
return spec;
}
TypeParameterSpec[] CreateGenericParameters (int first, MetaType[] tparams)
{
var tspec = new TypeParameterSpec[tparams.Length - first];
for (int pos = first; pos < tparams.Length; ++pos) {
var type = tparams[pos];
int index = pos - first;
tspec[index] = (TypeParameterSpec) CreateType (type, new DynamicTypeReader (), false);
}
return tspec;
}
public ImportedGenericMethodDefinition (MethodInfo provider, TypeSpec type, AParametersCollection parameters, TypeParameterSpec[] tparams, MetadataImporter importer)
: base (provider, type, parameters, importer)
{
this.tparams = tparams;
}
void ImportTypeParameterTypeConstraints (TypeParameterSpec spec, MetaType type)
{
var constraints = type.GetGenericParameterConstraints ();
List<TypeSpec> tparams = null;
foreach (var ct in constraints) {
if (ct.IsGenericParameter) {
if (tparams == null)
tparams = new List<TypeSpec> ();
tparams.Add (CreateType (ct));
continue;
}
var constraint_type = CreateType (ct);
if (constraint_type.IsClass) {
spec.BaseType = constraint_type;
continue;
}
spec.AddInterface (constraint_type);
}
if (spec.BaseType == null)
spec.BaseType = module.Compiler.BuiltinTypes.Object;
if (tparams != null)
spec.TypeArguments = tparams.ToArray ();
}
public HoistedStoreyClass (TypeDefinition parent, MemberName name, TypeParameters tparams, Modifiers mods, MemberKind kind)
: base (parent, name, mods | Modifiers.PRIVATE, kind)
{
if (tparams != null) {
var type_params = name.TypeParameters;
var src = new TypeParameterSpec[tparams.Count];
var dst = new TypeParameterSpec[tparams.Count];
for (int i = 0; i < tparams.Count; ++i) {
type_params[i] = tparams[i].CreateHoistedCopy (spec);
src[i] = tparams[i].Type;
dst[i] = type_params[i].Type;
}
// A copy is not enough, inflate any type parameter constraints
// using a new type parameters
var inflator = new TypeParameterInflator (this, null, src, dst);
for (int i = 0; i < tparams.Count; ++i) {
src[i].InflateConstraints (inflator, dst[i]);
}
mutator = new TypeParameterMutator (tparams, type_params);
}
}
