|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.FindSymbols;
using Microsoft.CodeAnalysis.FindUsages;
using Microsoft.CodeAnalysis.Navigation;
using Microsoft.CodeAnalysis.PooledObjects;
namespace Microsoft.CodeAnalysis.GoToDefinition;
internal static class GoToDefinitionFeatureHelpers
{
public static async Task<ISymbol?> TryGetPreferredSymbolAsync(
Solution solution, ISymbol? symbol, CancellationToken cancellationToken)
{
// VB global import aliases have a synthesized SyntaxTree.
// We can't go to the definition of the alias, so use the target type.
var alias = symbol as IAliasSymbol;
if (alias != null)
{
if (alias.Target is INamespaceSymbol ns && ns.IsGlobalNamespace)
return null;
}
// VB global import aliases have a synthesized SyntaxTree.
// We can't go to the definition of the alias, so use the target type.
if (alias != null)
{
var sourceLocations = NavigableItemFactory.GetPreferredSourceLocations(
solution, symbol, cancellationToken);
if (sourceLocations.All(l => solution.GetDocument(l.SourceTree) == null))
symbol = alias.Target;
}
var definition = await SymbolFinder.FindSourceDefinitionAsync(symbol, solution, cancellationToken).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
symbol = definition ?? symbol;
// If symbol has a partial implementation part, prefer to go to it, since that is where the body is.
symbol = (symbol as IMethodSymbol)?.PartialImplementationPart ?? symbol;
symbol = (symbol as IPropertySymbol)?.PartialImplementationPart ?? symbol;
return symbol;
}
public static async Task<ImmutableArray<DefinitionItem>> GetDefinitionsAsync(
ISymbol? symbol,
Solution solution,
bool thirdPartyNavigationAllowed,
CancellationToken cancellationToken)
{
symbol = await TryGetPreferredSymbolAsync(solution, symbol, cancellationToken).ConfigureAwait(false);
if (symbol is null)
return [];
using var _ = ArrayBuilder<DefinitionItem>.GetInstance(out var definitions);
// Going to a symbol may end up actually showing the symbol in the Find-Usages window.
// This happens when there is more than one location for the symbol (i.e. for partial
// symbols) and we don't know the best place to take you to.
//
// The FindUsages window supports showing the classified text for an item. It does this
// in two ways. Either the item can pass along its classified text (and the window will
// defer to that), or the item will have no classified text, and the window will compute
// it in the BG.
//
// Passing along the classified information is valuable for OOP scenarios where we want
// all that expensive computation done on the OOP side and not in the VS side.
//
// However, Go To Definition is all in-process, and is also synchronous. So we do not
// want to fetch the classifications here. It slows down the command and leads to a
// measurable delay in our perf tests.
//
// So, if we only have a single location to go to, this does no unnecessary work. And,
// if we do have multiple locations to show, it will just be done in the BG, unblocking
// this command thread so it can return the user faster.
var definitionItem = symbol.ToNonClassifiedDefinitionItem(solution, includeHiddenLocations: true);
if (thirdPartyNavigationAllowed)
{
var provider = solution.Services.GetService<IExternalDefinitionItemProvider>();
if (provider != null)
{
var thirdPartyItem = await provider.GetThirdPartyDefinitionItemAsync(solution, definitionItem, cancellationToken).ConfigureAwait(false);
definitions.AddIfNotNull(thirdPartyItem);
}
}
definitions.Add(definitionItem);
return definitions.ToImmutableAndClear();
}
}
|