public static string OperatorNameFromDeclaration(Syntax.InternalSyntax.OperatorDeclarationSyntax declaration)
{
var opTokenKind = declaration.OperatorToken.Kind;
if (SyntaxFacts.IsBinaryExpressionOperatorToken(opTokenKind))
{
// Some tokens may be either unary or binary operators (e.g. +, -).
if (SyntaxFacts.IsPrefixUnaryExpressionOperatorToken(opTokenKind) &&
declaration.ParameterList.Parameters.Count == 1)
{
return(OperatorFacts.UnaryOperatorNameFromSyntaxKind(opTokenKind));
}
return(OperatorFacts.BinaryOperatorNameFromSyntaxKind(opTokenKind));
}
else if (SyntaxFacts.IsUnaryOperatorDeclarationToken(opTokenKind))
{
return(OperatorFacts.UnaryOperatorNameFromSyntaxKind(opTokenKind));
}
else
{
// fallback for error recovery
return(WellKnownMemberNames.UnaryPlusOperatorName);
}
}
// NOTE: not guaranteed to be a method (e.g. class op_Addition)
// NOTE: constructor fallback logic applies
private ImmutableArray <Symbol> BindOperatorMemberCref(OperatorMemberCrefSyntax syntax, NamespaceOrTypeSymbol containerOpt, out Symbol ambiguityWinner, DiagnosticBag diagnostics)
{
const int arity = 0;
CrefParameterListSyntax parameterListSyntax = syntax.Parameters;
// NOTE: Prefer binary to unary, unless there is exactly one parameter.
// CONSIDER: we're following dev11 by never using a binary operator name if there's
// exactly one parameter, but doing so would allow us to match single-parameter constructors.
SyntaxKind operatorTokenKind = syntax.OperatorToken.Kind();
string memberName = parameterListSyntax != null && parameterListSyntax.Parameters.Count == 1
? null
: OperatorFacts.BinaryOperatorNameFromSyntaxKindIfAny(operatorTokenKind);
memberName = memberName ?? OperatorFacts.UnaryOperatorNameFromSyntaxKindIfAny(operatorTokenKind);
if (memberName == null)
{
ambiguityWinner = null;
return(ImmutableArray <Symbol> .Empty);
}
ImmutableArray <Symbol> sortedSymbols = ComputeSortedCrefMembers(syntax, containerOpt, memberName, arity, syntax.Parameters != null, diagnostics);
if (sortedSymbols.IsEmpty)
{
ambiguityWinner = null;
return(ImmutableArray <Symbol> .Empty);
}
return(ProcessCrefMemberLookupResults(
sortedSymbols,
arity,
syntax,
typeArgumentListSyntax: null,
parameterListSyntax: parameterListSyntax,
ambiguityWinner: out ambiguityWinner,
diagnostics: diagnostics));
}
private static void AddNonTypeMemberNames(
Syntax.InternalSyntax.CSharpSyntaxNode member, ImmutableHashSet <string> .Builder set, ref bool anyNonTypeMembers)
{
switch (member.Kind)
{
case SyntaxKind.FieldDeclaration:
anyNonTypeMembers = true;
set.Add(((Syntax.InternalSyntax.FieldDeclarationSyntax)member).Declaration.Identifier.ValueText);
break;
case SyntaxKind.EventFieldDeclaration:
anyNonTypeMembers = true;
set.Add(((Syntax.InternalSyntax.EventFieldDeclarationSyntax)member).Declaration.Identifier.ValueText);
break;
case SyntaxKind.MethodDeclaration:
anyNonTypeMembers = true;
// Member names are exposed via NamedTypeSymbol.MemberNames and are used primarily
// as an acid test to determine whether a more in-depth search of a type is worthwhile.
// We decided that it was reasonable to exclude explicit interface implementations
// from the list of member names.
var methodDecl = (Syntax.InternalSyntax.MethodDeclarationSyntax)member;
if (methodDecl.ExplicitInterfaceSpecifier == null)
{
set.Add(methodDecl.Identifier.ValueText);
}
break;
case SyntaxKind.PropertyDeclaration:
anyNonTypeMembers = true;
// Handle in the same way as explicit method implementations
var propertyDecl = (Syntax.InternalSyntax.PropertyDeclarationSyntax)member;
if (propertyDecl.ExplicitInterfaceSpecifier == null)
{
set.Add(propertyDecl.Identifier.ValueText);
}
break;
case SyntaxKind.EventDeclaration:
anyNonTypeMembers = true;
// Handle in the same way as explicit method implementations
var eventDecl = (Syntax.InternalSyntax.EventDeclarationSyntax)member;
if (eventDecl.ExplicitInterfaceSpecifier == null)
{
set.Add(eventDecl.Identifier.ValueText);
}
break;
case SyntaxKind.ConstructorDeclaration:
anyNonTypeMembers = true;
set.Add(((Syntax.InternalSyntax.ConstructorDeclarationSyntax)member).Modifiers.Any((int)SyntaxKind.StaticKeyword)
? WellKnownMemberNames.StaticConstructorName
: WellKnownMemberNames.InstanceConstructorName);
break;
case SyntaxKind.DestructorDeclaration:
anyNonTypeMembers = true;
set.Add(WellKnownMemberNames.DestructorName);
break;
case SyntaxKind.IndexerDeclaration:
anyNonTypeMembers = true;
set.Add(WellKnownMemberNames.Indexer);
break;
case SyntaxKind.OperatorDeclaration:
anyNonTypeMembers = true;
var opDecl = (Syntax.InternalSyntax.OperatorDeclarationSyntax)member;
var name = OperatorFacts.OperatorNameFromDeclaration(opDecl);
set.Add(name);
break;
case SyntaxKind.ConversionOperatorDeclaration:
anyNonTypeMembers = true;
set.Add(((Syntax.InternalSyntax.ConversionOperatorDeclarationSyntax)member).ImplicitOrExplicitKeyword.Kind == SyntaxKind.ImplicitKeyword
? WellKnownMemberNames.ImplicitConversionName
: WellKnownMemberNames.ExplicitConversionName);
break;
case SyntaxKind.GlobalStatement:
anyNonTypeMembers = true;
break;
}
}
// Returns true if there were any applicable candidates.
private bool GetUserDefinedOperators(UnaryOperatorKind kind, BoundExpression operand, ArrayBuilder <UnaryOperatorAnalysisResult> results, ref HashSet <DiagnosticInfo> useSiteDiagnostics)
{
Debug.Assert(operand != null);
if ((object)operand.Type == null)
{
// If the operand has no type -- because it is a null reference or a lambda or a method group --
// there is no way we can determine what type to search for user-defined operators.
return(false);
}
// Spec 7.3.5 Candidate user-defined operators
// SPEC: Given a type T and an operation op(A) ... the set of candidate user-defined
// SPEC: operators provided by T for op(A) is determined as follows:
// SPEC: If T is a nullable type then T0 is its underlying type; otherwise T0 is T.
// SPEC: For all operator declarations in T0 and all lifted forms of such operators, if
// SPEC: at least one operator is applicable with respect to A then the set of candidate
// SPEC: operators consists of all such applicable operators. Otherwise, if T0 is object
// SPEC: then the set of candidate operators is empty. Otherwise, the set of candidate
// SPEC: operators is the set provided by the direct base class of T0, or the effective
// SPEC: base class of T0 if T0 is a type parameter.
TypeSymbol type0 = operand.Type.StrippedType();
// Searching for user-defined operators is expensive; let's take an early out if we can.
if (OperatorFacts.DefinitelyHasNoUserDefinedOperators(type0))
{
return(false);
}
string name = OperatorFacts.UnaryOperatorNameFromOperatorKind(kind);
var operators = ArrayBuilder <UnaryOperatorSignature> .GetInstance();
bool hadApplicableCandidates = false;
NamedTypeSymbol current = type0 as NamedTypeSymbol;
if ((object)current == null)
{
current = type0.BaseTypeWithDefinitionUseSiteDiagnostics(ref useSiteDiagnostics);
}
if ((object)current == null && type0.IsTypeParameter())
{
current = ((TypeParameterSymbol)type0).EffectiveBaseClass(ref useSiteDiagnostics);
}
for (; (object)current != null; current = current.BaseTypeWithDefinitionUseSiteDiagnostics(ref useSiteDiagnostics))
{
operators.Clear();
GetUserDefinedUnaryOperatorsFromType(current, kind, name, operators);
results.Clear();
if (CandidateOperators(operators, operand, results, ref useSiteDiagnostics))
{
hadApplicableCandidates = true;
break;
}
}
operators.Free();
return(hadApplicableCandidates);
}