public MethodGroupResolution(
MethodGroup methodGroup,
Symbol otherSymbol,
OverloadResolutionResult<MethodSymbol> overloadResolutionResult,
AnalyzedArguments analyzedArguments,
LookupResultKind resultKind,
ImmutableArray<Diagnostic> diagnostics,
bool extensionMethodsOfSameViabilityAreAvailable)
{
Debug.Assert((methodGroup == null) || (methodGroup.Methods.Count > 0));
Debug.Assert((methodGroup == null) || ((object)otherSymbol == null));
// Methods should be represented in the method group.
Debug.Assert(((object)otherSymbol == null) || (otherSymbol.Kind != SymbolKind.Method));
Debug.Assert(resultKind != LookupResultKind.Ambiguous); // HasAnyApplicableMethod is expecting Viable methods.
Debug.Assert(!diagnostics.IsDefault);
Debug.Assert(!extensionMethodsOfSameViabilityAreAvailable || methodGroup == null || !methodGroup.IsExtensionMethodGroup);
this.MethodGroup = methodGroup;
this.OtherSymbol = otherSymbol;
this.OverloadResolutionResult = overloadResolutionResult;
this.AnalyzedArguments = analyzedArguments;
this.ResultKind = resultKind;
this.Diagnostics = diagnostics;
this.ExtensionMethodsOfSameViabilityAreAvailable = extensionMethodsOfSameViabilityAreAvailable;
}
public MethodGroupResolution(
MethodGroup methodGroup,
OverloadResolutionResult<MethodSymbol> overloadResolutionResult,
AnalyzedArguments analyzedArguments,
ImmutableArray<Diagnostic> diagnostics)
: this(methodGroup, null, overloadResolutionResult, analyzedArguments, methodGroup.ResultKind, diagnostics)
{
}
private static Conversion ToConversion(OverloadResolutionResult<MethodSymbol> result, MethodGroup methodGroup, NamedTypeSymbol delegateType)
{
// 6.6 An implicit conversion (6.1) exists from a method group (7.1) to a compatible
// delegate type. Given a delegate type D and an expression E that is classified as
// a method group, an implicit conversion exists from E to D if E contains at least
// one method that is applicable in its normal form (7.5.3.1) to an argument list
// constructed by use of the parameter types and modifiers of D...
// SPEC VIOLATION: Unfortunately, we cannot exactly implement the specification for
// the scenario in which an extension method that extends a value type is converted
// to a delegate. The code we generate that captures a delegate to a static method
// that is "partially evaluated" with the bound-to-the-delegate first argument
// requires that the first argument be of reference type.
// SPEC VIOLATION: Similarly, we cannot capture a method of Nullable<T>, because
// boxing a Nullable<T> gives a T, not a boxed Nullable<T>. (We can capture methods
// of object on a nullable receiver, but not GetValueOrDefault.)
if (!result.Succeeded)
{
return Conversion.NoConversion;
}
MethodSymbol method = result.BestResult.Member;
if (methodGroup.IsExtensionMethodGroup && !method.Parameters[0].Type.IsReferenceType)
{
return Conversion.NoConversion;
}
if (method.OriginalDefinition.ContainingType.SpecialType == SpecialType.System_Nullable_T &&
!method.IsOverride)
{
return Conversion.NoConversion;
}
// NOTE: Section 6.6 will be slightly updated:
//
// - The candidate methods considered are only those methods that are applicable in their
// normal form (§7.5.3.1), and do not omit any optional parameters. Thus, candidate methods
// are ignored if they are applicable only in their expanded form, or if one or more of their
// optional parameters do not have a corresponding parameter in the targeted delegate type.
//
// Therefore, we shouldn't get here unless the parameter count matches.
// NOTE: Delegate type compatibility is important, but is not part of the existence check.
Debug.Assert(method.ParameterCount == delegateType.DelegateInvokeMethod.ParameterCount + (methodGroup.IsExtensionMethodGroup ? 1 : 0));
return new Conversion(ConversionKind.MethodGroup, method, methodGroup.IsExtensionMethodGroup);
}
public Conversion MethodGroupConversion(CSharpSyntaxNode syntax, MethodGroup methodGroup, NamedTypeSymbol delegateType, ref HashSet<DiagnosticInfo> useSiteDiagnostics)
{
var analyzedArguments = AnalyzedArguments.GetInstance();
var result = OverloadResolutionResult<MethodSymbol>.GetInstance();
Debug.Assert((object)delegateType.DelegateInvokeMethod != null && !delegateType.DelegateInvokeMethod.HasUseSiteError,
"This method should only be called for valid delegate types");
GetDelegateArguments(syntax, analyzedArguments, delegateType.DelegateInvokeMethod.Parameters, binder.Compilation);
this.binder.OverloadResolution.MethodInvocationOverloadResolution(
methodGroup.Methods, methodGroup.TypeArguments, analyzedArguments, result, ref useSiteDiagnostics, isMethodGroupConversion: true);
var conversion = ToConversion(result, methodGroup, delegateType);
analyzedArguments.Free();
result.Free();
return conversion;
}
public MethodGroupResolution(MethodGroup methodGroup, ImmutableArray<Diagnostic> diagnostics)
: this(methodGroup, null, null, null, methodGroup.ResultKind, diagnostics)
{
}
private static Conversion ToConversion(OverloadResolutionResult <MethodSymbol> result, MethodGroup methodGroup, NamedTypeSymbol delegateType)
{
// 6.6 An implicit conversion (6.1) exists from a method group (7.1) to a compatible
// delegate type. Given a delegate type D and an expression E that is classified as
// a method group, an implicit conversion exists from E to D if E contains at least
// one method that is applicable in its normal form (7.5.3.1) to an argument list
// constructed by use of the parameter types and modifiers of D...
// SPEC VIOLATION: Unfortunately, we cannot exactly implement the specification for
// the scenario in which an extension method that extends a value type is converted
// to a delegate. The code we generate that captures a delegate to a static method
// that is "partially evaluated" with the bound-to-the-delegate first argument
// requires that the first argument be of reference type.
// SPEC VIOLATION: Similarly, we cannot capture a method of Nullable<T>, because
// boxing a Nullable<T> gives a T, not a boxed Nullable<T>. (We can capture methods
// of object on a nullable receiver, but not GetValueOrDefault.)
if (!result.Succeeded)
{
return(Conversion.NoConversion);
}
MethodSymbol method = result.BestResult.Member;
if (methodGroup.IsExtensionMethodGroup && !method.Parameters[0].Type.IsReferenceType)
{
return(Conversion.NoConversion);
}
//cannot capture stack-only types.
if (!method.IsStatic && methodGroup.Receiver?.Type?.IsRestrictedType() == true)
{
return(Conversion.NoConversion);
}
if (method.ContainingType.IsNullableType() && !method.IsOverride)
{
return(Conversion.NoConversion);
}
// NOTE: Section 6.6 will be slightly updated:
//
// - The candidate methods considered are only those methods that are applicable in their
// normal form (§7.5.3.1), and do not omit any optional parameters. Thus, candidate methods
// are ignored if they are applicable only in their expanded form, or if one or more of their
// optional parameters do not have a corresponding parameter in the targeted delegate type.
//
// Therefore, we shouldn't get here unless the parameter count matches.
// NOTE: Delegate type compatibility is important, but is not part of the existence check.
Debug.Assert(method.ParameterCount == delegateType.DelegateInvokeMethod.ParameterCount + (methodGroup.IsExtensionMethodGroup ? 1 : 0));
return(new Conversion(ConversionKind.MethodGroup, method, methodGroup.IsExtensionMethodGroup));
}
public MethodGroupResolution(MethodGroup methodGroup, ImmutableArray <Diagnostic> diagnostics)
: this(methodGroup, otherSymbol : null, overloadResolutionResult : null, analyzedArguments : null, methodGroup.ResultKind, diagnostics)
{
}
public MethodGroupResolution(MethodGroup methodGroup, ImmutableArray <Diagnostic> diagnostics)
: this(methodGroup, null, null, null, methodGroup.ResultKind, diagnostics)
{
}