private EntityHandle MakeTypeRefHandle(TypeDesc type)
{
Debug.Assert(type.IsTypeDefinition);
Debug.Assert((type is EcmaType) || _typeSystemContext.IsCanonicalDefinitionType(type, CanonicalFormKind.Any));
EntityHandle handle;
if (!_typeRefOrSpecHandles.TryGetValue(type, out handle))
{
if (_typeSystemContext.IsCanonicalDefinitionType(type, CanonicalFormKind.Any))
{
CanonBaseType canonType = (CanonBaseType)type;
handle = _metadataBuilder.AddTypeReference(
MakeCorlibAssemblyReferenceHandle(),
_metadataBuilder.GetOrAddString(canonType.Namespace),
_metadataBuilder.GetOrAddString(canonType.Name));
}
else
{
EntityHandle scope;
EcmaType typeAsEcmaType = (EcmaType)type;
if (typeAsEcmaType.ContainingType != null)
{
scope = MakeTypeRefHandle(typeAsEcmaType.ContainingType);
}
else
{
scope = MakeAssemblyReferenceHandle((EcmaAssembly)typeAsEcmaType.EcmaModule);
}
handle = _metadataBuilder.AddTypeReference(
scope,
_metadataBuilder.GetOrAddString(typeAsEcmaType.Namespace),
_metadataBuilder.GetOrAddString(typeAsEcmaType.Name));
}
_typeRefOrSpecHandles[type] = handle;
}
return(handle);
}
/// <summary>
/// Gets the comparer type that is suitable to compare instances of <paramref name="type"/>
/// or null if such comparer cannot be determined at compile time.
/// </summary>
private static TypeDesc GetComparerForType(TypeDesc type, string flavor, string interfaceName)
{
TypeSystemContext context = type.Context;
if (context.IsCanonicalDefinitionType(type, CanonicalFormKind.Any) ||
(type.IsRuntimeDeterminedSubtype && !type.HasInstantiation))
{
// The comparer will be determined at runtime. We can't tell the exact type at compile time.
return(null);
}
else if (type.IsNullable)
{
TypeDesc nullableType = type.Instantiation[0];
if (context.IsCanonicalDefinitionType(nullableType, CanonicalFormKind.Universal))
{
// We can't tell at compile time either.
return(null);
}
else if (ImplementsInterfaceOfSelf(nullableType, interfaceName))
{
return(context.SystemModule.GetKnownType("System.Collections.Generic", $"Nullable{flavor}`1")
.MakeInstantiatedType(nullableType));
}
}
else if (flavor == "EqualityComparer" && type.IsEnum)
{
// Enums have a specialized comparer that avoids boxing
return(context.SystemModule.GetKnownType("System.Collections.Generic", $"Enum{flavor}`1")
.MakeInstantiatedType(type));
}
else if (ImplementsInterfaceOfSelf(type, interfaceName))
{
return(context.SystemModule.GetKnownType("System.Collections.Generic", $"Generic{flavor}`1")
.MakeInstantiatedType(type));
}
return(context.SystemModule.GetKnownType("System.Collections.Generic", $"Object{flavor}`1")
.MakeInstantiatedType(type));
}
/// <summary>
/// Gets the set of template types needed to support loading comparers for the give canonical type at runtime.
/// </summary>
private static TypeDesc[] GetPotentialComparersForTypeCommon(TypeDesc type, string flavor, string interfaceName)
{
Debug.Assert(type.IsCanonicalSubtype(CanonicalFormKind.Any));
TypeDesc exactComparer = GetComparerForType(type, flavor, interfaceName);
if (exactComparer != null)
{
// If we have a comparer that is exactly known at runtime, we're done.
// This will typically be if type is a generic struct, generic enum, or a nullable.
return(new TypeDesc[] { exactComparer });
}
TypeSystemContext context = type.Context;
if (context.IsCanonicalDefinitionType(type, CanonicalFormKind.Universal))
{
// This can be any of the comparers we have.
ArrayBuilder <TypeDesc> universalComparers = new ArrayBuilder <TypeDesc>();
universalComparers.Add(context.SystemModule.GetKnownType("System.Collections.Generic", $"Nullable{flavor}`1")
.MakeInstantiatedType(type));
if (flavor == "EqualityComparer")
{
universalComparers.Add(context.SystemModule.GetKnownType("System.Collections.Generic", $"Enum{flavor}`1")
.MakeInstantiatedType(type));
}
universalComparers.Add(context.SystemModule.GetKnownType("System.Collections.Generic", $"Generic{flavor}`1")
.MakeInstantiatedType(type));
universalComparers.Add(context.SystemModule.GetKnownType("System.Collections.Generic", $"Object{flavor}`1")
.MakeInstantiatedType(type));
return(universalComparers.ToArray());
}
// This mirrors exactly what GetUnknownEquatableComparer and GetUnknownComparer (in the class library)
// will need at runtime. This is the general purpose code path that can be used to compare
// anything.
if (type.IsNullable)
{
TypeDesc nullableType = type.Instantiation[0];
// This should only be reachabe for universal canon code.
// For specific canon, this should have been an exact match above.
Debug.Assert(context.IsCanonicalDefinitionType(nullableType, CanonicalFormKind.Universal));
return(new TypeDesc[]
{
context.SystemModule.GetKnownType("System.Collections.Generic", $"Nullable{flavor}`1")
.MakeInstantiatedType(nullableType),
context.SystemModule.GetKnownType("System.Collections.Generic", $"Object{flavor}`1")
.MakeInstantiatedType(type),
});
}
return(new TypeDesc[]
{
context.SystemModule.GetKnownType("System.Collections.Generic", $"Generic{flavor}`1")
.MakeInstantiatedType(type),
context.SystemModule.GetKnownType("System.Collections.Generic", $"Object{flavor}`1")
.MakeInstantiatedType(type),
});
}