public static Instantiation ConvertInstantiationToSharedRuntimeForm(Instantiation instantiation, Instantiation openInstantiation, out bool changed)
{
Debug.Assert(instantiation.Length == openInstantiation.Length);
TypeDesc[] sharedInstantiation = null;
CanonicalFormKind currentPolicy = CanonicalFormKind.Specific;
CanonicalFormKind startLoopPolicy;
do
{
startLoopPolicy = currentPolicy;
for (int instantiationIndex = 0; instantiationIndex < instantiation.Length; instantiationIndex++)
{
TypeDesc typeToConvert = instantiation[instantiationIndex];
TypeSystemContext context = typeToConvert.Context;
TypeDesc canonForm = context.ConvertToCanon(typeToConvert, ref currentPolicy);
TypeDesc runtimeDeterminedForm = typeToConvert;
Debug.Assert(openInstantiation[instantiationIndex] is GenericParameterDesc);
if ((typeToConvert != canonForm) || typeToConvert.IsCanonicalType)
{
Debug.Assert(canonForm is DefType);
if (sharedInstantiation == null)
{
sharedInstantiation = new TypeDesc[instantiation.Length];
for (int i = 0; i < instantiationIndex; i++)
{
sharedInstantiation[i] = instantiation[i];
}
}
runtimeDeterminedForm = context.GetRuntimeDeterminedType(
(DefType)canonForm, (GenericParameterDesc)openInstantiation[instantiationIndex]);
}
if (sharedInstantiation != null)
{
sharedInstantiation[instantiationIndex] = runtimeDeterminedForm;
}
}
// Optimization: even if canonical policy changed, we don't actually need to re-run the loop
// for instantiations that only have a single element.
if (instantiation.Length == 1)
{
break;
}
} while (currentPolicy != startLoopPolicy);
changed = sharedInstantiation != null;
if (changed)
{
return(new Instantiation(sharedInstantiation));
}
return(instantiation);
}
