public static int GetHashCodeFor(TypeReference obj)
{
// a very good prime number
const int hashCodeMultiplier = 486187739;
// prime numbers
const int genericInstanceTypeMultiplier = 31;
const int byReferenceMultiplier = 37;
const int pointerMultiplier = 41;
const int requiredModifierMultiplier = 43;
const int optionalModifierMultiplier = 47;
const int pinnedMultiplier = 53;
const int sentinelMultiplier = 59;
var metadataType = obj.MetadataType;
if (metadataType == MetadataType.GenericInstance)
{
var genericInstanceType = (GenericInstanceType)obj;
var hashCode = GetHashCodeFor(genericInstanceType.ElementType) * hashCodeMultiplier + genericInstanceTypeMultiplier;
for (var i = 0; i < genericInstanceType.GenericArguments.Count; i++)
{
hashCode = hashCode * hashCodeMultiplier + GetHashCodeFor(genericInstanceType.GenericArguments[i]);
}
return(hashCode);
}
if (metadataType == MetadataType.Array)
{
var arrayType = (ArrayType)obj;
return(GetHashCodeFor(arrayType.ElementType) * hashCodeMultiplier + arrayType.Rank.GetHashCode());
}
if (metadataType == MetadataType.Var || metadataType == MetadataType.MVar)
{
var genericParameter = (GenericParameter)obj;
var hashCode = genericParameter.Position.GetHashCode() * hashCodeMultiplier + ((int)metadataType).GetHashCode();
var ownerTypeReference = genericParameter.Owner as TypeReference;
if (ownerTypeReference != null)
{
return(hashCode * hashCodeMultiplier + GetHashCodeFor(ownerTypeReference));
}
var ownerMethodReference = genericParameter.Owner as MethodReference;
if (ownerMethodReference != null)
{
return(hashCode * hashCodeMultiplier + MethodReferenceComparer.GetHashCodeFor(ownerMethodReference));
}
throw new InvalidOperationException("Generic parameter encountered with invalid owner");
}
if (metadataType == MetadataType.ByReference)
{
var byReferenceType = (ByReferenceType)obj;
return(GetHashCodeFor(byReferenceType.ElementType) * hashCodeMultiplier * byReferenceMultiplier);
}
if (metadataType == MetadataType.Pointer)
{
var pointerType = (PointerType)obj;
return(GetHashCodeFor(pointerType.ElementType) * hashCodeMultiplier * pointerMultiplier);
}
if (metadataType == MetadataType.RequiredModifier)
{
var requiredModifierType = (RequiredModifierType)obj;
var hashCode = GetHashCodeFor(requiredModifierType.ElementType) * requiredModifierMultiplier;
hashCode = hashCode * hashCodeMultiplier + GetHashCodeFor(requiredModifierType.ModifierType);
return(hashCode);
}
if (metadataType == MetadataType.OptionalModifier)
{
var optionalModifierType = (OptionalModifierType)obj;
var hashCode = GetHashCodeFor(optionalModifierType.ElementType) * optionalModifierMultiplier;
hashCode = hashCode * hashCodeMultiplier + GetHashCodeFor(optionalModifierType.ModifierType);
return(hashCode);
}
if (metadataType == MetadataType.Pinned)
{
var pinnedType = (PinnedType)obj;
return(GetHashCodeFor(pinnedType.ElementType) * hashCodeMultiplier * pinnedMultiplier);
}
if (metadataType == MetadataType.Sentinel)
{
var sentinelType = (SentinelType)obj;
return(GetHashCodeFor(sentinelType.ElementType) * hashCodeMultiplier * sentinelMultiplier);
}
if (metadataType == MetadataType.FunctionPointer)
{
throw new NotImplementedException("We currently don't handle function pointer types.");
}
return(obj.Namespace.GetHashCode() * hashCodeMultiplier + obj.FullName.GetHashCode());
}
static bool AreEqual(GenericParameter a, GenericParameter b, TypeComparisonMode comparisonMode = TypeComparisonMode.Exact)
{
if (ReferenceEquals(a, b))
{
return(true);
}
if (a.Position != b.Position)
{
return(false);
}
if (a.Type != b.Type)
{
return(false);
}
var aOwnerType = a.Owner as TypeReference;
if (aOwnerType != null && AreEqual(aOwnerType, b.Owner as TypeReference, comparisonMode))
{
return(true);
}
var aOwnerMethod = a.Owner as MethodReference;
if (aOwnerMethod != null && comparisonMode != TypeComparisonMode.SignatureOnlyLoose && MethodReferenceComparer.AreEqual(aOwnerMethod, b.Owner as MethodReference))
{
return(true);
}
return(comparisonMode == TypeComparisonMode.SignatureOnly || comparisonMode == TypeComparisonMode.SignatureOnlyLoose);
}
