> GetElementAccessExpressionParameterLists(
SemanticModel semanticModel,
int position,
ElementAccessExpressionSyntax elementAccessExpression,
CancellationToken cancellationToken
)
{
var expressionSymbol = semanticModel
.GetSymbolInfo(elementAccessExpression.Expression, cancellationToken)
.GetAnySymbol();
var expressionType =
semanticModel.GetTypeInfo(
elementAccessExpression.Expression,
cancellationToken
).Type;
if (expressionSymbol != null && expressionType != null)
{
var indexers = semanticModel
.LookupSymbols(position, expressionType, WellKnownMemberNames.Indexer)
.OfType<IPropertySymbol>();
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(
position,
cancellationToken
);
if (within != null)
{
return indexers
.Where(i => i.IsAccessibleWithin(within, throughType: expressionType))
.Select(i => i.Parameters);
}
}
return null;
}
private IEnumerable <ImmutableArray <IParameterSymbol> > GetInvocationExpressionParameterLists(
SemanticModel semanticModel,
int position,
InvocationExpressionSyntax invocationExpression,
CancellationToken cancellationToken)
{
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (within != null)
{
var methodGroup = semanticModel.GetMemberGroup(invocationExpression.Expression, cancellationToken).OfType <IMethodSymbol>();
var expressionType = semanticModel.GetTypeInfo(invocationExpression.Expression, cancellationToken).Type as INamedTypeSymbol;
if (methodGroup.Any())
{
return(methodGroup.Where(m => m.IsAccessibleWithin(within))
.Select(m => m.Parameters));
}
else if (expressionType.IsDelegateType())
{
var delegateType = expressionType;
return(SpecializedCollections.SingletonEnumerable(delegateType.DelegateInvokeMethod.Parameters));
}
}
return(null);
}
private IEnumerable <ISymbol> GetAttributeNamedParameters(
SemanticModel semanticModel,
int position,
AttributeSyntax attribute,
CancellationToken cancellationToken)
{
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
var attributeType = semanticModel.GetTypeInfo(attribute, cancellationToken).Type as INamedTypeSymbol;
return(attributeType.GetAttributeNamedParameters(semanticModel.Compilation, within));
}
private IEnumerable <ImmutableArray <IParameterSymbol> > GetParameterLists(
SemanticModel semanticModel,
int position,
AttributeSyntax attribute,
CancellationToken cancellationToken)
{
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (within != null && semanticModel.GetTypeInfo(attribute, cancellationToken).Type is INamedTypeSymbol attributeType)
{
return(attributeType.InstanceConstructors.Where(c => c.IsAccessibleWithin(within))
.Select(c => c.Parameters));
}
return(SpecializedCollections.EmptyEnumerable <ImmutableArray <IParameterSymbol> >());
}
ParameterHintingResult HandleObjectCreationExpression(SemanticModel semanticModel, SyntaxNode node, CancellationToken cancellationToken)
{
// var info = semanticModel.GetSymbolInfo(node, cancellationToken);
var result = new ParameterHintingResult(node.SpanStart);
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(node.SpanStart, cancellationToken);
var targetTypeInfo = semanticModel.GetTypeInfo(node);
if (targetTypeInfo.Type != null)
{
foreach (IMethodSymbol c in targetTypeInfo.Type.GetMembers().OfType <IMethodSymbol>().Where(m => m.MethodKind == MethodKind.Constructor))
{
if (c.IsAccessibleWithin(within))
{
result.AddData(factory.CreateConstructorProvider(c));
}
}
}
return(result);
}
> GetRecordBaseTypeParameterLists(
SemanticModel semanticModel,
int position,
PrimaryConstructorBaseTypeSyntax recordBaseType,
CancellationToken cancellationToken
)
{
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (within != null)
{
var type =
semanticModel.GetTypeInfo(recordBaseType.Type, cancellationToken).Type
as INamedTypeSymbol;
return type?.InstanceConstructors.Where(m => m.IsAccessibleWithin(within))
.Select(m => m.Parameters);
}
return null;
}
ParameterHintingResult HandleElementAccessExpression(SemanticModel semanticModel, ElementAccessExpressionSyntax node, CancellationToken cancellationToken)
{
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(node.SpanStart, cancellationToken);
var targetTypeInfo = semanticModel.GetTypeInfo(node.Expression);
ITypeSymbol type = targetTypeInfo.Type;
if (type == null)
{
return(ParameterHintingResult.Empty);
}
var result = new ParameterHintingResult(node.SpanStart);
if (type.TypeKind == TypeKind.Array)
{
result.AddData(factory.CreateArrayDataProvider((IArrayTypeSymbol)type));
return(result);
}
var addedProperties = new List <IPropertySymbol> ();
for (; type != null; type = type.BaseType)
{
foreach (var indexer in type.GetMembers().OfType <IPropertySymbol> ().Where(p => p.IsIndexer))
{
if (addedProperties.Any(added => SignatureComparer.HaveSameSignature(indexer, added, true)))
{
continue;
}
if (indexer.IsAccessibleWithin(within))
{
addedProperties.Add(indexer);
result.AddData(factory.CreateIndexerParameterDataProvider(indexer, node));
}
}
}
return(result);
}
ParameterHintingResult HandleConstructorInitializer(SemanticModel semanticModel, SyntaxNode node, CancellationToken cancellationToken)
{
var info = semanticModel.GetSymbolInfo(node, cancellationToken);
var result = new ParameterHintingResult(node.SpanStart);
var resolvedMethod = info.Symbol as IMethodSymbol;
if (resolvedMethod != null)
{
var type = resolvedMethod.ContainingType;
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(node.SpanStart, cancellationToken);
result.AddRange(type.GetMembers()
.OfType <IMethodSymbol> ()
.Where(m => m.MethodKind == MethodKind.Constructor && m.IsAccessibleWithin(within))
.Select(factory.CreateConstructorProvider));
}
else
{
result.AddRange(info.CandidateSymbols.OfType <IMethodSymbol> ().Select(factory.CreateConstructorProvider));
}
return(result);
}
ParameterHintingResult HandleInvocationExpression(SemanticModel semanticModel, InvocationExpressionSyntax node, CancellationToken cancellationToken)
{
var info = semanticModel.GetSymbolInfo(node, cancellationToken);
var result = new ParameterHintingResult(node.SpanStart);
var targetTypeInfo = semanticModel.GetTypeInfo(node.Expression);
if (targetTypeInfo.Type != null && targetTypeInfo.Type.TypeKind == TypeKind.Delegate)
{
result.AddData(factory.CreateMethodDataProvider(targetTypeInfo.Type.GetDelegateInvokeMethod()));
return(result);
}
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(node.SpanStart, cancellationToken);
ITypeSymbol type;
var ma = node.Expression as MemberAccessExpressionSyntax;
string name = null;
bool staticLookup = false;
if (ma != null)
{
staticLookup = semanticModel.GetSymbolInfo(ma.Expression).Symbol is ITypeSymbol;
type = semanticModel.GetTypeInfo(ma.Expression).Type;
name = info.Symbol?.Name ?? ma.Name.Identifier.ValueText;
}
else
{
type = within as ITypeSymbol;
name = info.Symbol?.Name ?? node.Expression.ToString();
var sym = semanticModel.GetEnclosingSymbol(node.SpanStart, cancellationToken);
staticLookup = sym.IsStatic;
}
var addedMethods = new List <IMethodSymbol> ();
var filterMethod = new HashSet <IMethodSymbol> ();
for (; type != null; type = type.BaseType)
{
foreach (var method in type.GetMembers().OfType <IMethodSymbol> ().Concat(GetExtensionMethods(semanticModel, type, node, cancellationToken)).Where(m => m.Name == name))
{
if (staticLookup && !method.IsStatic)
{
continue;
}
if (method.OverriddenMethod != null)
{
filterMethod.Add(method.OverriddenMethod);
}
if (filterMethod.Contains(method))
{
continue;
}
if (addedMethods.Any(added => SignatureComparer.HaveSameSignature(method, added, true)))
{
continue;
}
if (method.IsAccessibleWithin(within))
{
if (info.Symbol != null)
{
var smethod = (IMethodSymbol)info.Symbol;
if (smethod != null && smethod.OriginalDefinition == method)
{
continue;
}
}
addedMethods.Add(method);
result.AddData(factory.CreateMethodDataProvider(method));
}
}
}
if (info.Symbol != null && !addedMethods.Contains(info.Symbol))
{
if (!staticLookup || info.Symbol.IsStatic)
{
result.AddData(factory.CreateMethodDataProvider((IMethodSymbol)info.Symbol));
}
}
return(result);
}
public static bool IsExpressionContext(
this SyntaxTree syntaxTree,
int position,
SyntaxToken tokenOnLeftOfPosition,
bool attributes,
CancellationToken cancellationToken,
SemanticModel semanticModelOpt = null)
{
// cases:
// var q = |
// var q = a|
// this list is *not* exhaustive.
var token = tokenOnLeftOfPosition.GetPreviousTokenIfTouchingWord(position);
if (token.GetAncestor<ConditionalDirectiveTriviaSyntax>() != null)
{
return false;
}
if (!attributes)
{
if (token.GetAncestor<AttributeListSyntax>() != null)
{
return false;
}
}
if (syntaxTree.IsConstantExpressionContext(position, tokenOnLeftOfPosition, cancellationToken))
{
return true;
}
// no expressions after . :: ->
if (token.IsKind(SyntaxKind.DotToken) ||
token.IsKind(SyntaxKind.ColonColonToken) ||
token.IsKind(SyntaxKind.MinusGreaterThanToken))
{
return false;
}
// Normally you can have any sort of expression after an equals. However, this does not
// apply to a "using Foo = ..." situation.
if (token.IsKind(SyntaxKind.EqualsToken))
{
if (token.Parent.IsKind(SyntaxKind.NameEquals) &&
token.Parent.IsParentKind(SyntaxKind.UsingDirective))
{
return false;
}
}
// q = |
// q -= |
// q *= |
// q += |
// q /= |
// q ^= |
// q %= |
// q &= |
// q |= |
// q <<= |
// q >>= |
if (token.IsKind(SyntaxKind.EqualsToken) ||
token.IsKind(SyntaxKind.MinusEqualsToken) ||
token.IsKind(SyntaxKind.AsteriskEqualsToken) ||
token.IsKind(SyntaxKind.PlusEqualsToken) ||
token.IsKind(SyntaxKind.SlashEqualsToken) ||
token.IsKind(SyntaxKind.ExclamationEqualsToken) ||
token.IsKind(SyntaxKind.CaretEqualsToken) ||
token.IsKind(SyntaxKind.AmpersandEqualsToken) ||
token.IsKind(SyntaxKind.BarEqualsToken) ||
token.IsKind(SyntaxKind.PercentEqualsToken) ||
token.IsKind(SyntaxKind.LessThanLessThanEqualsToken) ||
token.IsKind(SyntaxKind.GreaterThanGreaterThanEqualsToken))
{
return true;
}
// ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.Parent.IsKind(SyntaxKind.ParenthesizedExpression))
{
return true;
}
// - |
// + |
// ~ |
// ! |
if (token.Parent is PrefixUnaryExpressionSyntax)
{
var prefix = token.Parent as PrefixUnaryExpressionSyntax;
return prefix.OperatorToken == token;
}
// not sure about these:
// ++ |
// -- |
#if false
token.Kind == SyntaxKind.PlusPlusToken ||
token.Kind == SyntaxKind.DashDashToken)
#endif
// await |
if (token.Parent is AwaitExpressionSyntax)
{
var awaitExpression = token.Parent as AwaitExpressionSyntax;
return awaitExpression.AwaitKeyword == token;
}
// Check for binary operators.
// Note:
// - We handle < specially as it can be ambiguous with generics.
// - We handle * specially because it can be ambiguous with pointer types.
// a *
// a /
// a %
// a +
// a -
// a <<
// a >>
// a <
// a >
// a &&
// a ||
// a &
// a |
// a ^
if (token.Parent is BinaryExpressionSyntax)
{
// If the client provided a binding, then check if this is actually generic. If so,
// then this is not an expression context. i.e. if we have "Foo < |" then it could
// be an expression context, or it could be a type context if Foo binds to a type or
// method.
if (semanticModelOpt != null && syntaxTree.IsGenericTypeArgumentContext(position, tokenOnLeftOfPosition, cancellationToken, semanticModelOpt))
{
return false;
}
var binary = token.Parent as BinaryExpressionSyntax;
if (binary.OperatorToken == token)
{
// If this is a multiplication expression and a semantic model was passed in,
// check to see if the expression to the left is a type name. If it is, treat
// this as a pointer type.
if (token.IsKind(SyntaxKind.AsteriskToken) && semanticModelOpt != null)
{
var type = binary.Left as TypeSyntax;
if (type != null && type.IsPotentialTypeName(semanticModelOpt, cancellationToken))
{
return false;
}
}
return true;
}
}
// Special case:
// Foo * bar
// Foo ? bar
// This parses as a local decl called bar of type Foo* or Foo?
if (tokenOnLeftOfPosition.IntersectsWith(position) &&
tokenOnLeftOfPosition.IsKind(SyntaxKind.IdentifierToken))
{
var previousToken = tokenOnLeftOfPosition.GetPreviousToken(includeSkipped: true);
if (previousToken.IsKind(SyntaxKind.AsteriskToken) ||
previousToken.IsKind(SyntaxKind.QuestionToken))
{
if (previousToken.Parent.IsKind(SyntaxKind.PointerType) ||
previousToken.Parent.IsKind(SyntaxKind.NullableType))
{
var type = previousToken.Parent as TypeSyntax;
if (type.IsParentKind(SyntaxKind.VariableDeclaration) &&
type.Parent.IsParentKind(SyntaxKind.LocalDeclarationStatement))
{
var declStatement = type.Parent.Parent as LocalDeclarationStatementSyntax;
// note, this doesn't apply for cases where we know it
// absolutely is not multiplication or a conditional expression.
var underlyingType = type is PointerTypeSyntax
? ((PointerTypeSyntax)type).ElementType
: ((NullableTypeSyntax)type).ElementType;
if (!underlyingType.IsPotentialTypeName(semanticModelOpt, cancellationToken))
{
return true;
}
}
}
}
}
// new int[|
// new int[expr, |
if (token.IsKind(SyntaxKind.OpenBracketToken) ||
token.IsKind(SyntaxKind.CommaToken))
{
if (token.Parent.IsKind(SyntaxKind.ArrayRankSpecifier))
{
return true;
}
}
// foo ? |
if (token.IsKind(SyntaxKind.QuestionToken) &&
token.Parent.IsKind(SyntaxKind.ConditionalExpression))
{
// If the condition is simply a TypeSyntax that binds to a type, treat this as a nullable type.
var conditionalExpression = (ConditionalExpressionSyntax)token.Parent;
var type = conditionalExpression.Condition as TypeSyntax;
return type == null
|| !type.IsPotentialTypeName(semanticModelOpt, cancellationToken);
}
// foo ? bar : |
if (token.IsKind(SyntaxKind.ColonToken) &&
token.Parent.IsKind(SyntaxKind.ConditionalExpression))
{
return true;
}
// typeof(|
// default(|
// sizeof(|
if (token.IsKind(SyntaxKind.OpenParenToken))
{
if (token.Parent.IsKind(SyntaxKind.TypeOfExpression, SyntaxKind.DefaultExpression, SyntaxKind.SizeOfExpression))
{
return false;
}
}
// var(|
// var(id, |
// Those are more likely to be deconstruction-declarations being typed than invocations a method "var"
if (token.IsKind(SyntaxKind.OpenParenToken, SyntaxKind.CommaToken) &&
token.IsInvocationOfVarExpression())
{
return false;
}
// Foo(|
// Foo(expr, |
// this[|
// var t = (1, |
// var t = (| , 2)
if (token.IsKind(SyntaxKind.OpenParenToken) ||
token.IsKind(SyntaxKind.OpenBracketToken) ||
token.IsKind(SyntaxKind.CommaToken))
{
if (token.Parent.IsKind(SyntaxKind.ArgumentList, SyntaxKind.BracketedArgumentList, SyntaxKind.TupleExpression))
{
return true;
}
}
// [Foo(|
// [Foo(expr, |
if (attributes)
{
if (token.IsKind(SyntaxKind.OpenParenToken) ||
token.IsKind(SyntaxKind.CommaToken))
{
if (token.Parent.IsKind(SyntaxKind.AttributeArgumentList))
{
return true;
}
}
}
// Foo(ref |
// Foo(bar |
if (token.IsKind(SyntaxKind.RefKeyword) ||
token.IsKind(SyntaxKind.OutKeyword))
{
if (token.Parent.IsKind(SyntaxKind.Argument))
{
return true;
}
}
// Foo(bar: |
if (token.IsKind(SyntaxKind.ColonToken) &&
token.Parent.IsKind(SyntaxKind.NameColon) &&
token.Parent.IsParentKind(SyntaxKind.Argument))
{
return true;
}
// a => |
if (token.IsKind(SyntaxKind.EqualsGreaterThanToken))
{
return true;
}
// new List<int> { |
// new List<int> { expr, |
if (token.IsKind(SyntaxKind.OpenBraceToken) ||
token.IsKind(SyntaxKind.CommaToken))
{
if (token.Parent is InitializerExpressionSyntax)
{
// The compiler treats the ambiguous case as an object initializer, so we'll say
// expressions are legal here
if (token.Parent.IsKind(SyntaxKind.ObjectInitializerExpression) && token.IsKind(SyntaxKind.OpenBraceToken))
{
// In this position { a$$ =, the user is trying to type an object initializer.
if (!token.IntersectsWith(position) && token.GetNextToken().GetNextToken().IsKind(SyntaxKind.EqualsToken))
{
return false;
}
return true;
}
// Perform a semantic check to determine whether or not the type being created
// can support a collection initializer. If not, this must be an object initializer
// and can't be an expression context.
if (semanticModelOpt != null &&
token.Parent.IsParentKind(SyntaxKind.ObjectCreationExpression))
{
var objectCreation = (ObjectCreationExpressionSyntax)token.Parent.Parent;
var type = semanticModelOpt.GetSymbolInfo(objectCreation.Type, cancellationToken).Symbol as ITypeSymbol;
var containingSymbol = semanticModelOpt.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (type != null && !type.CanSupportCollectionInitializer(containingSymbol))
{
return false;
}
}
return true;
}
}
// for (; |
// for (; ; |
if (token.IsKind(SyntaxKind.SemicolonToken) &&
token.Parent.IsKind(SyntaxKind.ForStatement))
{
var forStatement = (ForStatementSyntax)token.Parent;
if (token == forStatement.FirstSemicolonToken ||
token == forStatement.SecondSemicolonToken)
{
return true;
}
}
// for ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.Parent.IsKind(SyntaxKind.ForStatement))
{
var forStatement = (ForStatementSyntax)token.Parent;
if (token == forStatement.OpenParenToken)
{
return true;
}
}
// for (; ; Foo(), |
// for ( Foo(), |
if (token.IsKind(SyntaxKind.CommaToken) &&
token.Parent.IsKind(SyntaxKind.ForStatement))
{
return true;
}
// foreach (var v in |
// from a in |
// join b in |
if (token.IsKind(SyntaxKind.InKeyword))
{
if (token.Parent.IsKind(SyntaxKind.ForEachStatement,
SyntaxKind.ForEachComponentStatement,
SyntaxKind.FromClause,
SyntaxKind.JoinClause))
{
return true;
}
}
// join x in y on |
// join x in y on a equals |
if (token.IsKind(SyntaxKind.OnKeyword) ||
token.IsKind(SyntaxKind.EqualsKeyword))
{
if (token.Parent.IsKind(SyntaxKind.JoinClause))
{
return true;
}
}
// where |
if (token.IsKind(SyntaxKind.WhereKeyword) &&
token.Parent.IsKind(SyntaxKind.WhereClause))
{
return true;
}
// orderby |
// orderby a, |
if (token.IsKind(SyntaxKind.OrderByKeyword) ||
token.IsKind(SyntaxKind.CommaToken))
{
if (token.Parent.IsKind(SyntaxKind.OrderByClause))
{
return true;
}
}
// select |
if (token.IsKind(SyntaxKind.SelectKeyword) &&
token.Parent.IsKind(SyntaxKind.SelectClause))
{
return true;
}
// group |
// group expr by |
if (token.IsKind(SyntaxKind.GroupKeyword) ||
token.IsKind(SyntaxKind.ByKeyword))
{
if (token.Parent.IsKind(SyntaxKind.GroupClause))
{
return true;
}
}
// return |
// yield return |
// but not: [return |
if (token.IsKind(SyntaxKind.ReturnKeyword))
{
if (token.GetPreviousToken(includeSkipped: true).Kind() != SyntaxKind.OpenBracketToken)
{
return true;
}
}
// throw |
if (token.IsKind(SyntaxKind.ThrowKeyword))
{
return true;
}
// while ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.WhileKeyword))
{
return true;
}
// todo: handle 'for' cases.
// using ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.UsingKeyword))
{
return true;
}
// lock ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.LockKeyword))
{
return true;
}
// lock ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.IfKeyword))
{
return true;
}
// switch ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.SwitchKeyword))
{
return true;
}
// checked ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.CheckedKeyword))
{
return true;
}
// unchecked ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.UncheckedKeyword))
{
return true;
}
// when ( |
if (token.IsKind(SyntaxKind.OpenParenToken) &&
token.GetPreviousToken(includeSkipped: true).IsKind(SyntaxKind.WhenKeyword))
{
return true;
}
// (SomeType) |
if (token.IsAfterPossibleCast())
{
return true;
}
// In anonymous type initializer.
//
// new { | We allow new inside of anonymous object member declarators, so that the user
// can dot into a member afterward. For example:
//
// var a = new { new C().Foo };
if (token.IsKind(SyntaxKind.OpenBraceToken) || token.IsKind(SyntaxKind.CommaToken))
{
if (token.Parent.IsKind(SyntaxKind.AnonymousObjectCreationExpression))
{
return true;
}
}
// $"{ |
// $@"{ |
// $"{x} { |
// $@"{x} { |
if (token.IsKind(SyntaxKind.OpenBraceToken))
{
return token.Parent.IsKind(SyntaxKind.Interpolation)
&& ((InterpolationSyntax)token.Parent).OpenBraceToken == token;
}
return false;
}
ParameterHintingResult HandleInvocationExpression(SemanticModel semanticModel, InvocationExpressionSyntax node, CancellationToken cancellationToken)
{
var result = new ParameterHintingResult(node.SpanStart);
var targetTypeInfo = semanticModel.GetTypeInfo(node.Expression);
if (targetTypeInfo.Type != null && targetTypeInfo.Type.TypeKind == TypeKind.Delegate)
{
result.AddData(factory.CreateMethodDataProvider(targetTypeInfo.Type.GetDelegateInvokeMethod()));
return(result);
}
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(node.SpanStart, cancellationToken);
if (within == null)
{
return(result);
}
var memberGroup = semanticModel.GetMemberGroup(node.Expression, cancellationToken).OfType <IMethodSymbol> ();
var matchedMethodSymbol = semanticModel.GetSymbolInfo(node, cancellationToken).Symbol as IMethodSymbol;
// if the symbol could be bound, replace that item in the symbol list
if (matchedMethodSymbol != null && matchedMethodSymbol.IsGenericMethod)
{
memberGroup = memberGroup.Select(m => matchedMethodSymbol.OriginalDefinition == m ? matchedMethodSymbol : m);
}
ITypeSymbol throughType = null;
if (node.Expression is MemberAccessExpressionSyntax)
{
var throughExpression = ((MemberAccessExpressionSyntax)node.Expression).Expression;
var throughSymbol = semanticModel.GetSymbolInfo(throughExpression, cancellationToken).GetAnySymbol();
// if it is via a base expression "base.", we know the "throughType" is the base class but
// we need to be able to tell between "base.M()" and "new Base().M()".
// currently, Access check methods do not differentiate between them.
// so handle "base." primary-expression here by nulling out "throughType"
if (!(throughExpression is BaseExpressionSyntax))
{
throughType = semanticModel.GetTypeInfo(throughExpression, cancellationToken).Type;
}
var includeInstance = !throughExpression.IsKind(SyntaxKind.IdentifierName) ||
semanticModel.LookupSymbols(throughExpression.SpanStart, name: throughSymbol.Name).Any(s => !(s is INamedTypeSymbol)) ||
(!(throughSymbol is INamespaceOrTypeSymbol) && semanticModel.LookupSymbols(throughExpression.SpanStart, container: throughSymbol.ContainingType).Any(s => !(s is INamedTypeSymbol)));
var includeStatic = throughSymbol is INamedTypeSymbol ||
(throughExpression.IsKind(SyntaxKind.IdentifierName) &&
semanticModel.LookupNamespacesAndTypes(throughExpression.SpanStart, name: throughSymbol.Name).Any(t => t.GetSymbolType() == throughType));
memberGroup = memberGroup.Where(m => (m.IsStatic && includeStatic) || (!m.IsStatic && includeInstance));
}
else if (node.Expression is SimpleNameSyntax && node.IsInStaticContext())
{
memberGroup = memberGroup.Where(m => m.IsStatic);
}
var methodList = memberGroup.Where(member => member.IsAccessibleWithin(within, throughType)).ToList();
memberGroup = methodList.Where(m => !IsHiddenByOtherMethod(m, methodList));
foreach (var member in memberGroup)
{
result.AddData(factory.CreateMethodDataProvider(member));
}
return(result);
}
static SignatureHelp CreateMethodGroupSignatureHelp(
ExpressionSyntax expression,
ArgumentListSyntax argumentList,
int position,
SemanticModel semanticModel)
{
var signatureHelp = new SignatureHelp();
// Happens for object initializers with no preceding parens, as soon as user types comma
if (argumentList == null)
{
return(signatureHelp);
}
int currentArg;
if (TryGetCurrentArgumentIndex(argumentList, position, out currentArg))
{
signatureHelp.ActiveParameter = currentArg;
}
var symbolInfo = semanticModel.GetSymbolInfo(expression);
var bestGuessMethod = symbolInfo.Symbol as IMethodSymbol;
// Include everything by default (global eval context)
var includeInstance = true;
var includeStatic = true;
ITypeSymbol throughType = null;
// When accessing method via some member, only show static methods in static context and vice versa for instance methods.
// This block based on https://github.com/dotnet/roslyn/blob/3b6536f4a616e5f3b8ede940c63663a828e68b5d/src/Features/CSharp/Portable/SignatureHelp/InvocationExpressionSignatureHelpProvider_MethodGroup.cs#L44-L50
if (expression is MemberAccessExpressionSyntax memberAccessExpression)
{
var throughExpression = (memberAccessExpression).Expression;
if (!(throughExpression is BaseExpressionSyntax))
{
throughType = semanticModel.GetTypeInfo(throughExpression).Type;
}
var throughSymbolInfo = semanticModel.GetSymbolInfo(throughExpression);
var throughSymbol = throughSymbolInfo.Symbol ?? throughSymbolInfo.CandidateSymbols.FirstOrDefault();
includeInstance = !throughExpression.IsKind(SyntaxKind.IdentifierName) ||
semanticModel.LookupSymbols(throughExpression.SpanStart, name: throughSymbol.Name).Any(s => !(s is INamedTypeSymbol)) ||
(!(throughSymbol is INamespaceOrTypeSymbol) && semanticModel.LookupSymbols(throughExpression.SpanStart, throughSymbol.ContainingType).Any(s => !(s is INamedTypeSymbol)));
includeStatic = throughSymbol is INamedTypeSymbol ||
(throughExpression.IsKind(SyntaxKind.IdentifierName) &&
semanticModel.LookupNamespacesAndTypes(throughExpression.SpanStart, name: throughSymbol.Name).Any(t => t.GetSymbolType() == throughType));
}
// TODO: Start taking CT in here? Most calls in this method have optional CT arg. Could make this async.
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, CancellationToken.None);
var methods = semanticModel
.GetMemberGroup(expression)
.OfType <IMethodSymbol> ()
.Where(m => (m.IsStatic && includeStatic) || (!m.IsStatic && includeInstance))
.Where(m => m.IsAccessibleWithin(within, throughTypeOpt: throughType))
.ToArray();
var signatures = new List <SignatureInformation> ();
for (var i = 0; i < methods.Length; i++)
{
if (methods [i] == bestGuessMethod)
{
signatureHelp.ActiveSignature = i;
}
var signatureInfo = new SignatureInformation(methods [i]);
signatures.Add(signatureInfo);
}
signatureHelp.Signatures = signatures.ToArray();
return(signatureHelp);
}