private ImmutableArray <ParameterSymbol> BindCrefParameters(BaseCrefParameterListSyntax parameterListSyntax, DiagnosticBag diagnostics)
{
ArrayBuilder <ParameterSymbol> parameterBuilder = ArrayBuilder <ParameterSymbol> .GetInstance(parameterListSyntax.Parameters.Count);
foreach (CrefParameterSyntax parameter in parameterListSyntax.Parameters)
{
RefKind refKind = parameter.RefOrOutKeyword.CSharpKind().GetRefKind();
TypeSymbol type = BindCrefParameterOrReturnType(parameter.Type, (MemberCrefSyntax)parameterListSyntax.Parent, diagnostics);
parameterBuilder.Add(new SignatureOnlyParameterSymbol(type, ImmutableArray <CustomModifier> .Empty, isParams: false, refKind: refKind));
}
return(parameterBuilder.ToImmutableAndFree());
}
/// <summary>
/// Given a list of viable lookup results (based on the name, arity, and containing symbol),
/// attempt to select one.
/// </summary>
private ImmutableArray <Symbol> ProcessCrefMemberLookupResults(
ImmutableArray <Symbol> symbols,
int arity,
MemberCrefSyntax memberSyntax,
TypeArgumentListSyntax typeArgumentListSyntax,
BaseCrefParameterListSyntax parameterListSyntax,
out Symbol ambiguityWinner,
DiagnosticBag diagnostics)
{
Debug.Assert(!symbols.IsEmpty);
if (parameterListSyntax == null)
{
return(ProcessParameterlessCrefMemberLookupResults(symbols, arity, memberSyntax, typeArgumentListSyntax, out ambiguityWinner, diagnostics));
}
ArrayBuilder <Symbol> candidates = ArrayBuilder <Symbol> .GetInstance();
GetCrefOverloadResolutionCandidates(symbols, arity, typeArgumentListSyntax, candidates);
ImmutableArray <ParameterSymbol> parameterSymbols = BindCrefParameters(parameterListSyntax, diagnostics);
ImmutableArray <Symbol> results = PerformCrefOverloadResolution(candidates, parameterSymbols, arity, memberSyntax, out ambiguityWinner, diagnostics);
candidates.Free();
// NOTE: This diagnostic is just a hint that might help fix a broken cref, so don't do
// any work unless there are no viable candidates.
if (results.Length == 0)
{
for (int i = 0; i < parameterSymbols.Length; i++)
{
if (ContainsNestedTypeOfUnconstructedGenericType(parameterSymbols[i].Type.TypeSymbol))
{
// This warning is new in Roslyn, because our better-defined semantics for
// cref lookup disallow some things that were possible in dev12.
//
// Consider the following code:
//
// public class C<T>
// {
// public class Inner { }
//
// public void M(Inner i) { }
//
// /// <see cref="M"/>
// /// <see cref="C{T}.M"/>
// /// <see cref="C{Q}.M"/>
// /// <see cref="C{Q}.M(C{Q}.Inner)"/>
// /// <see cref="C{Q}.M(Inner)"/> // WRN_UnqualifiedNestedTypeInCref
// public void N() { }
// }
//
// Dev12 binds all of the crefs as "M:C`1.M(C{`0}.Inner)".
// Roslyn accepts all but the last. The issue is that the context for performing
// the lookup is not C<Q>, but C<T>. Consequently, Inner binds to C<T>.Inner and
// then overload resolution fails because C<T>.Inner does not match C<Q>.Inner,
// the parameter type of C<Q>.M. Since we could not agree that the old behavior
// was desirable (other than for backwards compatibility) and since mimicking it
// would have been expensive, we settled on introducing a new warning that at
// least hints to the user how then can work around the issue (i.e. by qualifying
// Inner as C{Q}.Inner). Additional details are available in DevDiv #743425.
//
// CONSIDER: We could actually put the qualified form in the warning message,
// but that would probably just make it more frustrating (i.e. if the compiler
// knows exactly what I mean, why do I have to type it).
//
// NOTE: This is not a great location (whole parameter instead of problematic type),
// but it's better than nothing.
diagnostics.Add(ErrorCode.WRN_UnqualifiedNestedTypeInCref, parameterListSyntax.Parameters[i].Location);
break;
}
}
}
return(results);
}
/// <summary>
/// Given a list of viable lookup results (based on the name, arity, and containing symbol),
/// attempt to select one.
/// </summary>
private ImmutableArray<Symbol> ProcessCrefMemberLookupResults(
ImmutableArray<Symbol> symbols,
int arity,
MemberCrefSyntax memberSyntax,
TypeArgumentListSyntax typeArgumentListSyntax,
BaseCrefParameterListSyntax parameterListSyntax,
out Symbol ambiguityWinner,
DiagnosticBag diagnostics)
{
Debug.Assert(!symbols.IsEmpty);
if (parameterListSyntax == null)
{
return ProcessParameterlessCrefMemberLookupResults(symbols, arity, memberSyntax, typeArgumentListSyntax, out ambiguityWinner, diagnostics);
}
ArrayBuilder<Symbol> candidates = ArrayBuilder<Symbol>.GetInstance();
GetCrefOverloadResolutionCandidates(symbols, arity, typeArgumentListSyntax, candidates);
ImmutableArray<ParameterSymbol> parameterSymbols = BindCrefParameters(parameterListSyntax, diagnostics);
ImmutableArray<Symbol> results = PerformCrefOverloadResolution(candidates, parameterSymbols, arity, memberSyntax, out ambiguityWinner, diagnostics);
candidates.Free();
// NOTE: This diagnostic is just a hint that might help fix a broken cref, so don't do
// any work unless there are no viable candidates.
if (results.Length == 0)
{
for (int i = 0; i < parameterSymbols.Length; i++)
{
if (ContainsNestedTypeOfUnconstructedGenericType(parameterSymbols[i].Type))
{
// This warning is new in Roslyn, because our better-defined semantics for
// cref lookup disallow some things that were possible in dev12.
//
// Consider the following code:
//
// public class C<T>
// {
// public class Inner { }
//
// public void M(Inner i) { }
//
// /// <see cref="M"/>
// /// <see cref="C{T}.M"/>
// /// <see cref="C{Q}.M"/>
// /// <see cref="C{Q}.M(C{Q}.Inner)"/>
// /// <see cref="C{Q}.M(Inner)"/> // WRN_UnqualifiedNestedTypeInCref
// public void N() { }
// }
//
// Dev12 binds all of the crefs as "M:C`1.M(C{`0}.Inner)".
// Roslyn accepts all but the last. The issue is that the context for performing
// the lookup is not C<Q>, but C<T>. Consequently, Inner binds to C<T>.Inner and
// then overload resolution fails because C<T>.Inner does not match C<Q>.Inner,
// the parameter type of C<Q>.M. Since we could not agree that the old behavior
// was desirable (other than for backwards compatibility) and since mimicking it
// would have been expensive, we settled on introducing a new warning that at
// least hints to the user how then can work around the issue (i.e. by qualifying
// Inner as C{Q}.Inner). Additional details are available in DevDiv #743425.
//
// CONSIDER: We could actually put the qualified form in the warning message,
// but that would probably just make it more frustrating (i.e. if the compiler
// knows exactly what I mean, why do I have to type it).
//
// NOTE: This is not a great location (whole parameter instead of problematic type),
// but it's better than nothing.
diagnostics.Add(ErrorCode.WRN_UnqualifiedNestedTypeInCref, parameterListSyntax.Parameters[i].Location);
break;
}
}
}
return results;
}
private ImmutableArray<ParameterSymbol> BindCrefParameters(BaseCrefParameterListSyntax parameterListSyntax, DiagnosticBag diagnostics)
{
ArrayBuilder<ParameterSymbol> parameterBuilder = ArrayBuilder<ParameterSymbol>.GetInstance(parameterListSyntax.Parameters.Count);
foreach (CrefParameterSyntax parameter in parameterListSyntax.Parameters)
{
RefKind refKind = parameter.RefOrOutKeyword.CSharpKind().GetRefKind();
TypeSymbol type = BindCrefParameterOrReturnType(parameter.Type, (MemberCrefSyntax)parameterListSyntax.Parent, diagnostics);
parameterBuilder.Add(new SignatureOnlyParameterSymbol(type, ImmutableArray<CustomModifier>.Empty, isParams: false, refKind: refKind));
}
return parameterBuilder.ToImmutableAndFree();
}
public TameBaseCrefParameterListSyntax(BaseCrefParameterListSyntax node)
{
Node = node;
AddChildren();
}
