public static ResolveResult Resolve(Lazy <ICompilation> compilation, CSharpUnresolvedFile unresolvedFile, SyntaxTree syntaxTree, TextLocation location, out AstNode node,
CancellationToken cancellationToken = default(CancellationToken))
{
node = syntaxTree.GetNodeAt(location);
if (node == null || node is ArrayInitializerExpression)
{
return(null);
}
if (node.Parent is UsingAliasDeclaration && node.Role == UsingAliasDeclaration.AliasRole)
{
var r = new CSharpAstResolver(compilation.Value, syntaxTree, unresolvedFile);
return(r.Resolve(((UsingAliasDeclaration)node.Parent).Import, cancellationToken));
}
if (CSharpAstResolver.IsUnresolvableNode(node))
{
if (node is Identifier)
{
node = node.Parent;
}
else if (node.NodeType == NodeType.Token)
{
if (node.Parent is IndexerExpression || node.Parent is ConstructorInitializer || node.Role == IndexerDeclaration.ThisKeywordRole)
{
// There's no other place where one could hover to see the indexer's tooltip,
// so we need to resolve it when hovering over the '[' or ']'.
// For constructor initializer, the same applies to the 'base'/'this' token.
node = node.Parent;
}
else if (node.Parent is BinaryOperatorExpression || node.Parent is UnaryOperatorExpression)
{
// Resolve user-defined operator
node = node.Parent;
}
else
{
return(null);
}
}
else
{
// don't resolve arbitrary nodes - we don't want to show tooltips for everything
return(null);
}
}
else
{
// It's a resolvable node.
// However, we usually don't want to show the tooltip everywhere
// For example, hovering with the mouse over an empty line between two methods causes
// node==TypeDeclaration, but we don't want to show any tooltip.
if (!node.GetChildByRole(Roles.Identifier).IsNull)
{
// We'll suppress the tooltip for resolvable nodes if there is an identifier that
// could be hovered over instead:
return(null);
}
}
if (node == null)
{
return(null);
}
if (node.Parent is ObjectCreateExpression && node.Role == Roles.Type)
{
node = node.Parent;
}
else if (node is ThisReferenceExpression && node.Parent is IndexerExpression)
{
node = node.Parent;
}
InvocationExpression parentInvocation = null;
if ((node is IdentifierExpression || node is MemberReferenceExpression || node is PointerReferenceExpression) && node.Role != Roles.Argument)
{
// we also need to resolve the invocation
parentInvocation = node.Parent as InvocationExpression;
}
// TODO: I think we should provide an overload so that an existing CSharpAstResolver can be reused
CSharpAstResolver resolver = new CSharpAstResolver(compilation.Value, syntaxTree, unresolvedFile);
ResolveResult rr = resolver.Resolve(node, cancellationToken);
if (rr is MethodGroupResolveResult mgrr)
{
// For method groups, resolve the parent invocation instead.
if (parentInvocation != null)
{
return(resolver.Resolve(parentInvocation));
}
if (node is Expression)
{
// If it's not an invocation, try if it's a conversion to a delegate type:
Conversion c = resolver.GetConversion((Expression)node, cancellationToken);
if (c.IsMethodGroupConversion)
{
return(new MemberResolveResult(mgrr.TargetResult, c.Method));
}
}
}
return(rr);
}
public CastResolveResult(IType targetType, ResolveResult input, Conversion conversion, bool checkForOverflow)
: base(targetType, input, conversion, checkForOverflow)
{
}
protected void AssertConversion(ResolveResult conversionResult, ResolveResult expectedRR, Conversion expectedConversion, string text)
{
if (expectedConversion == Conversion.IdentityConversion)
{
Assert.AreSame(expectedRR, conversionResult, "Expected no " + text);
}
else
{
ConversionResolveResult crr = conversionResult as ConversionResolveResult;
Assert.IsNotNull(crr, "Could not find ConversionResolveResult for " + text);
Assert.AreEqual(expectedConversion, crr.Conversion, text);
Assert.AreSame(expectedRR, crr.Input, "Input of " + text);
}
}
void CheckApplicability(Candidate candidate)
{
// C# 4.0 spec: §7.5.3.1 Applicable function member
// Test whether parameters were mapped the correct number of arguments:
int[] argumentCountPerParameter = new int[candidate.ParameterTypes.Length];
foreach (int parameterIndex in candidate.ArgumentToParameterMap)
{
if (parameterIndex >= 0)
{
argumentCountPerParameter[parameterIndex]++;
}
}
for (int i = 0; i < argumentCountPerParameter.Length; i++)
{
if (candidate.IsExpandedForm && i == argumentCountPerParameter.Length - 1)
{
continue; // any number of arguments is fine for the params-array
}
if (argumentCountPerParameter[i] == 0)
{
if (this.AllowOptionalParameters && candidate.Parameters[i].IsOptional)
{
candidate.HasUnmappedOptionalParameters = true;
}
else
{
candidate.AddError(OverloadResolutionErrors.MissingArgumentForRequiredParameter);
}
}
else if (argumentCountPerParameter[i] > 1)
{
candidate.AddError(OverloadResolutionErrors.MultipleArgumentsForSingleParameter);
}
}
candidate.ArgumentConversions = new Conversion[arguments.Length];
// Test whether argument passing mode matches the parameter passing mode
for (int i = 0; i < arguments.Length; i++)
{
int parameterIndex = candidate.ArgumentToParameterMap[i];
if (parameterIndex < 0)
{
candidate.ArgumentConversions[i] = Conversion.None;
continue;
}
ByReferenceResolveResult brrr = arguments[i] as ByReferenceResolveResult;
if (brrr != null)
{
if ((brrr.IsOut && !candidate.Parameters[parameterIndex].IsOut) || (brrr.IsRef && !candidate.Parameters[parameterIndex].IsRef))
{
candidate.AddError(OverloadResolutionErrors.ParameterPassingModeMismatch);
}
}
else
{
if (candidate.Parameters[parameterIndex].IsOut || candidate.Parameters[parameterIndex].IsRef)
{
candidate.AddError(OverloadResolutionErrors.ParameterPassingModeMismatch);
}
}
IType parameterType = candidate.ParameterTypes[parameterIndex];
Conversion c = conversions.ImplicitConversion(arguments[i], parameterType);
candidate.ArgumentConversions[i] = c;
if (IsExtensionMethodInvocation && parameterIndex == 0)
{
// First parameter to extension method must be an identity, reference or boxing conversion
if (!(c == Conversion.IdentityConversion || c == Conversion.ImplicitReferenceConversion || c == Conversion.BoxingConversion))
{
candidate.AddError(OverloadResolutionErrors.ArgumentTypeMismatch);
}
}
else
{
if ((!c.IsValid && !c.IsUserDefined && !c.IsMethodGroupConversion) && parameterType.Kind != TypeKind.Unknown)
{
candidate.AddError(OverloadResolutionErrors.ArgumentTypeMismatch);
}
}
}
}
/// <inheritdoc/>
public void ProcessConversion(Expression expression, ResolveResult result, Conversion conversion, IType targetType)
{
navigator.ProcessConversion(expression, result, conversion, targetType);
}
void IResolveVisitorNavigator.ProcessConversion(Expression expression, ResolveResult result, Conversion conversion, IType targetType)
{
}