/// <summary>
/// Generates the LSIF content for a single document.
/// </summary>
/// <returns>The ID of the outputted Document vertex.</returns>
/// <remarks>
/// The high level algorithm here is we are going to walk across each token, produce a <see cref="Graph.Range"/> for that token's span,
/// bind that token, and then link up the various features. So we'll link that range to the symbols it defines or references,
/// will link it to results like Quick Info, and more. This method has a <paramref name="topLevelSymbolsResultSetTracker"/> that
/// lets us link symbols across files, and will only talk about "top level" symbols that aren't things like locals that can't
/// leak outside a file.
/// </remarks>
private static Id <Graph.LsifDocument> GenerateForDocument(
SemanticModel semanticModel,
HostLanguageServices languageServices,
OptionSet options,
IResultSetTracker topLevelSymbolsResultSetTracker,
ILsifJsonWriter lsifJsonWriter,
IdFactory idFactory)
{
var syntaxTree = semanticModel.SyntaxTree;
var sourceText = semanticModel.SyntaxTree.GetText();
var syntaxFactsService = languageServices.GetRequiredService <ISyntaxFactsService>();
var semanticFactsService = languageServices.GetRequiredService <ISemanticFactsService>();
string?contentBase64Encoded = null;
// TODO: move to checking the enum member mentioned in https://github.com/dotnet/roslyn/issues/49326 when that
// is implemented. In the mean time, we'll use a heuristic of the path being a relative path as a way to indicate
// this is a source generated file.
if (!PathUtilities.IsAbsolute(syntaxTree.FilePath))
{
var text = semanticModel.SyntaxTree.GetText();
// We always use UTF-8 encoding when writing out file contents, as that's expected by LSIF implementations.
// TODO: when we move to .NET Core, is there a way to reduce allocatios here?
contentBase64Encoded = Convert.ToBase64String(Encoding.UTF8.GetBytes(text.ToString()));
}
var documentVertex = new Graph.LsifDocument(new Uri(syntaxTree.FilePath, UriKind.RelativeOrAbsolute), GetLanguageKind(semanticModel.Language), contentBase64Encoded, idFactory);
lsifJsonWriter.Write(documentVertex);
lsifJsonWriter.Write(new Event(Event.EventKind.Begin, documentVertex.GetId(), idFactory));
// As we are processing this file, we are going to encounter symbols that have a shared resultSet with other documents like types
// or methods. We're also going to encounter locals that never leave this document. We don't want those locals being held by
// the topLevelSymbolsResultSetTracker, so we'll make another tracker for document local symbols, and then have a delegating
// one that picks the correct one of the two.
var documentLocalSymbolsResultSetTracker = new SymbolHoldingResultSetTracker(lsifJsonWriter, semanticModel.Compilation, idFactory);
var symbolResultsTracker = new DelegatingResultSetTracker(symbol =>
{
if (symbol.Kind == SymbolKind.Local ||
symbol.Kind == SymbolKind.RangeVariable ||
symbol.Kind == SymbolKind.Label)
{
// These symbols can go in the document local one because they can't escape methods
return(documentLocalSymbolsResultSetTracker);
}
else if (symbol.ContainingType != null && symbol.DeclaredAccessibility == Accessibility.Private && symbol.ContainingType.Locations.Length == 1)
{
// This is a private member in a class that isn't partial, so it can't escape the file
return(documentLocalSymbolsResultSetTracker);
}
else
{
return(topLevelSymbolsResultSetTracker);
}
});
// We will walk the file token-by-token, making a range for each one and then attaching information for it
var rangeVertices = new List <Id <Graph.Range> >();
foreach (var syntaxToken in syntaxTree.GetRoot().DescendantTokens(descendIntoTrivia: true))
{
// We'll only create the Range vertex once it's needed, but any number of bits of code might create it first,
// so we'll just make it Lazy.
var lazyRangeVertex = new Lazy <Graph.Range>(() =>
{
var rangeVertex = Graph.Range.FromTextSpan(syntaxToken.Span, sourceText, idFactory);
lsifJsonWriter.Write(rangeVertex);
rangeVertices.Add(rangeVertex.GetId());
return(rangeVertex);
}, LazyThreadSafetyMode.None);
var declaredSymbol = semanticFactsService.GetDeclaredSymbol(semanticModel, syntaxToken, CancellationToken.None);
ISymbol?referencedSymbol = null;
if (syntaxFactsService.IsBindableToken(syntaxToken))
{
var bindableParent = syntaxFactsService.TryGetBindableParent(syntaxToken);
if (bindableParent != null)
{
var symbolInfo = semanticModel.GetSymbolInfo(bindableParent);
if (symbolInfo.Symbol != null && IncludeSymbolInReferences(symbolInfo.Symbol))
{
referencedSymbol = symbolInfo.Symbol;
}
}
}
if (declaredSymbol != null || referencedSymbol != null)
{
// For now, we will link the range to the original definition, preferring the definition, as this is the symbol
// that would be used if we invoke a feature on this range. This is analogous to the logic in
// SymbolFinder.FindSymbolAtPositionAsync where if a token is both a reference and definition we'll prefer the
// definition. Once we start supporting hover we'll have to remove the "original definition" part of this, since
// since we show different contents for different constructed types there.
var symbolForLinkedResultSet = (declaredSymbol ?? referencedSymbol) !.OriginalDefinition;
var symbolForLinkedResultSetId = symbolResultsTracker.GetResultSetIdForSymbol(symbolForLinkedResultSet);
lsifJsonWriter.Write(Edge.Create("next", lazyRangeVertex.Value.GetId(), symbolForLinkedResultSetId, idFactory));
if (declaredSymbol != null)
{
var definitionResultsId = symbolResultsTracker.GetResultIdForSymbol(declaredSymbol, Methods.TextDocumentDefinitionName, () => new DefinitionResult(idFactory));
lsifJsonWriter.Write(new Item(definitionResultsId.As <DefinitionResult, Vertex>(), lazyRangeVertex.Value.GetId(), documentVertex.GetId(), idFactory));
}
if (referencedSymbol != null)
{
// Create the link from the references back to this range. Note: this range can be reference to a
// symbol but the range can point a different symbol's resultSet. This can happen if the token is
// both a definition of a symbol (where we will point to the definition) but also a reference to some
// other symbol.
var referenceResultsId = symbolResultsTracker.GetResultIdForSymbol(referencedSymbol.OriginalDefinition, Methods.TextDocumentReferencesName, () => new ReferenceResult(idFactory));
lsifJsonWriter.Write(new Item(referenceResultsId.As <ReferenceResult, Vertex>(), lazyRangeVertex.Value.GetId(), documentVertex.GetId(), idFactory, property: "references"));
}
// Write hover information for the symbol, if edge has not already been added.
// 'textDocument/hover' edge goes from the symbol ResultSet vertex to the hover result
// See https://github.com/Microsoft/language-server-protocol/blob/main/indexFormat/specification.md#resultset for an example.
if (symbolResultsTracker.ResultSetNeedsInformationalEdgeAdded(symbolForLinkedResultSet, Methods.TextDocumentHoverName))
{
// TODO: Can we avoid the WaitAndGetResult_CanCallOnBackground call by adding a sync method to compute hover?
var hover = HoverHandler.GetHoverAsync(semanticModel, syntaxToken.SpanStart, languageServices, CancellationToken.None).WaitAndGetResult_CanCallOnBackground(CancellationToken.None);
if (hover != null)
{
var hoverResult = new HoverResult(hover, idFactory);
lsifJsonWriter.Write(hoverResult);
lsifJsonWriter.Write(Edge.Create(Methods.TextDocumentHoverName, symbolForLinkedResultSetId, hoverResult.GetId(), idFactory));
}
}
}
}
lsifJsonWriter.Write(Edge.Create("contains", documentVertex.GetId(), rangeVertices, idFactory));
// Write the folding ranges for the document.
var foldingRanges = FoldingRangesHandler.GetFoldingRanges(syntaxTree, languageServices, options, isMetadataAsSource: false, CancellationToken.None);
var foldingRangeResult = new FoldingRangeResult(foldingRanges, idFactory);
lsifJsonWriter.Write(foldingRangeResult);
lsifJsonWriter.Write(Edge.Create(Methods.TextDocumentFoldingRangeName, documentVertex.GetId(), foldingRangeResult.GetId(), idFactory));
lsifJsonWriter.Write(new Event(Event.EventKind.End, documentVertex.GetId(), idFactory));
return(documentVertex.GetId());
}
