public int GetHashCode(Symbol member)
{
int hash = 1;
if ((object)member != null)
{
hash = Hash.Combine((int)member.Kind, hash);
if (_considerName)
{
hash = Hash.Combine(ExplicitInterfaceHelpers.GetMemberNameWithoutInterfaceName(member.Name), hash);
// CONSIDER: could use interface type, but that might be quite expensive
}
if (_considerReturnType && member.GetMemberArity() == 0 &&
(_typeComparison & TypeCompareKind.AllIgnoreOptions) == 0) // If it is generic, then type argument might be in return type.
{
hash = Hash.Combine(member.GetTypeOrReturnType().GetHashCode(), hash);
}
// CONSIDER: modify hash for constraints?
hash = Hash.Combine(member.GetMemberArity(), hash);
hash = Hash.Combine(member.GetParameterCount(), hash);
}
return(hash);
}
internal static string GetMemberCallerName(this Symbol member)
{
if (member.Kind == SymbolKind.Method)
{
member = ((MethodSymbol)member).AssociatedSymbol ?? member;
}
return(member.IsIndexer() ? member.MetadataName :
member.IsExplicitInterfaceImplementation() ? ExplicitInterfaceHelpers.GetMemberNameWithoutInterfaceName(member.Name) :
member.Name);
}
public bool Equals(Symbol member1, Symbol member2)
{
if (ReferenceEquals(member1, member2))
{
return(true);
}
if ((object)member1 == null || (object)member2 == null || member1.Kind != member2.Kind)
{
return(false);
}
bool sawInterfaceInName1 = false;
bool sawInterfaceInName2 = false;
if (_considerName)
{
string name1 = ExplicitInterfaceHelpers.GetMemberNameWithoutInterfaceName(member1.Name);
string name2 = ExplicitInterfaceHelpers.GetMemberNameWithoutInterfaceName(member2.Name);
sawInterfaceInName1 = name1 != member1.Name;
sawInterfaceInName2 = name2 != member2.Name;
if (name1 != name2)
{
return(false);
}
}
// NB: up to, and including, this check, we have not actually forced the (type) parameters
// to be expanded - we're only using the counts.
int arity = member1.GetMemberArity();
if ((arity != member2.GetMemberArity()) ||
(member1.GetParameterCount() != member2.GetParameterCount()))
{
return(false);
}
TypeMap typeMap1;
TypeMap typeMap2;
if (arity > 0 && _useSpecialHandlingForNullableTypes)
{
// We need this special handling in order to avoid forcing resolution of nullable types
// in signature of an overriding member while we are looking for a matching overridden member.
// Doing the resolution in the original signature can send us into an infinite cycle because
// constraints must be inherited from the member we are looking for.
// It is important to ensure that the fact whether an indexed type parameter we are about to use
// is a reference type is inherited from the corresponding type parameter of the possibly overridden
// member (which is member2 when _useSpecialHandlingForNullableTypes is true). This will ensure
// proper resolution for nullable types in substituted signature of member1, ensuring proper
// comparison of types across both members.
ArrayBuilder <TypeParameterSymbol> builder = ArrayBuilder <TypeParameterSymbol> .GetInstance(arity);
var typeParameters2 = member2.GetMemberTypeParameters();
for (int i = arity - 1; i >= 0; i--)
{
builder.Add(IndexedTypeParameterSymbolForOverriding.GetTypeParameter(i, typeParameters2[i].IsValueType));
}
var indexed = builder.ToImmutableAndFree();
typeMap1 = new TypeMap(member1.GetMemberTypeParameters(), indexed, true);
typeMap2 = new TypeMap(typeParameters2, indexed, true);
}
else
{
typeMap1 = GetTypeMap(member1);
typeMap2 = GetTypeMap(member2);
}
if ((_considerReturnRefKindDifferences || _considerReturnType) && !HaveSameReturnTypes(member1, typeMap1, member2, typeMap2, _typeComparison))
{
return(false);
}
if (member1.GetParameterCount() > 0 && !HaveSameParameterTypes(member1.GetParameters(), typeMap1, member2.GetParameters(), typeMap2,
_considerRefKindDifferences, _typeComparison))
{
return(false);
}
if (_considerCallingConvention)
{
if (GetCallingConvention(member1) != GetCallingConvention(member2))
{
return(false);
}
}
else
{
if (IsVarargMethod(member1) != IsVarargMethod(member2))
{
return(false);
}
}
if (_considerExplicitlyImplementedInterfaces)
{
if (sawInterfaceInName1 != sawInterfaceInName2)
{
return(false);
}
// The purpose of this check is to determine whether the interface parts of the member names agree,
// but to do so using robust symbolic checks, rather than syntactic ones. Therefore, if neither member
// name contains an interface name, this check is not relevant.
// Phrased differently, the explicitly implemented interface is not part of the signature unless it's
// part of the name.
if (sawInterfaceInName1)
{
Debug.Assert(sawInterfaceInName2);
// May avoid realizing interface members.
if (member1.IsExplicitInterfaceImplementation() != member2.IsExplicitInterfaceImplementation())
{
return(false);
}
// By comparing symbols, rather than syntax, we gain the flexibility of ignoring whitespace
// and gracefully accepting multiple names for the same (or equivalent) types (e.g. "I<int>.M"
// vs "I<System.Int32>.M"), but we lose the connection with the name. For example, in metadata,
// a method name "I.M" could have nothing to do with "I" but explicitly implement interface "I2".
// We will behave as if the method was really named "I2.M". Furthermore, in metadata, a method
// can explicitly implement more than one interface method, in which case it doesn't really
// make sense to pretend that all of them are part of the signature.
var explicitInterfaceImplementations1 = member1.GetExplicitInterfaceImplementations();
var explicitInterfaceImplementations2 = member2.GetExplicitInterfaceImplementations();
if (!explicitInterfaceImplementations1.SetEquals(explicitInterfaceImplementations2, EqualityComparer <Symbol> .Default))
{
return(false);
}
}
}
return(!_considerTypeConstraints || HaveSameConstraints(member1, typeMap1, member2, typeMap2));
}