Merge pull request #41274 from allisonchou/AddParameterCrash

Fix for Visual Studio crashes when adding a parameter to a function

src/EditorFeatures/VisualBasicTest/SignatureHelp/InvocationExpressionSignatureHelpProviderTests.vb

@@ -1972,5 +1972,25 @@ End Class
 
             Await TestAsync(markup, expectedOrderedItems)
         End Function
+
+        <WorkItem(40451, "https://github.com/dotnet/roslyn/issues/40451")>
+        <Fact, Trait(Traits.Feature, Traits.Features.SignatureHelp)>
+        Public Async Function TestSigHelpIsVisibleWithDuplicateMethodNames() As Task
+            Dim markup = "
+Class C
+    Shared Sub Test()
+        M(1, 2$$)
+    End Sub
+
+    Sub M(y As Integer)
+    End Sub
+
+    Shared Sub M(x As Integer, y As Integer)
+    End Sub
+End Class
+"
+
+            Await TestAsync(markup, {New SignatureHelpTestItem("C.M(x As Integer, y As Integer)")})
+        End Function
     End Class
 End Namespace

src/Features/Core/Portable/SignatureHelp/AbstractSignatureHelpProvider.cs

@@ -340,7 +340,6 @@ protected async Task<List<Tuple<Document, IEnumerable<SignatureHelpItem>>>> GetI
             foreach (var relatedDocumentId in relatedDocuments)
             {
                 var relatedDocument = document.Project.Solution.GetDocument(relatedDocumentId);
-                var semanticModel = await relatedDocument.GetSemanticModelForSpanAsync(new TextSpan(position, 0), cancellationToken).ConfigureAwait(false);
                 var result = await GetItemsWorkerAsync(relatedDocument, position, triggerInfo, cancellationToken).ConfigureAwait(false);
 
                 supportedPlatforms.Add(Tuple.Create(relatedDocument, result != null ? result.Items : SpecializedCollections.EmptyEnumerable<SignatureHelpItem>()));

src/Features/VisualBasic/Portable/SignatureHelp/InvocationExpressionSignatureHelpProvider.MemberGroup.vb

@@ -2,22 +2,20 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
+Imports System.Collections.Immutable
 Imports System.Threading
-Imports Microsoft.CodeAnalysis.DocumentationComments
-Imports Microsoft.CodeAnalysis.LanguageServices
 Imports Microsoft.CodeAnalysis.SignatureHelp
 Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.SignatureHelp
 
     Partial Friend Class InvocationExpressionSignatureHelpProvider
 
-        Private Function GetMemberGroupItems(document As Document,
-                                             invocationExpression As InvocationExpressionSyntax,
+        Private Function GetAccessibleMembers(invocationExpression As InvocationExpressionSyntax,
                                              semanticModel As SemanticModel,
                                              within As ISymbol,
                                              memberGroup As IEnumerable(Of ISymbol),
-                                             cancellationToken As CancellationToken) As IEnumerable(Of SignatureHelpItem)
+                                             cancellationToken As CancellationToken) As ImmutableArray(Of ISymbol)
             Dim throughType As ITypeSymbol = Nothing
             Dim expression = TryCast(invocationExpression.Expression, MemberAccessExpressionSyntax).GetExpressionOfMemberAccessExpression()
 
@@ -34,8 +32,15 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.SignatureHelp
                 memberGroup = memberGroup.Where(Function(m) m.IsStatic)
             End If
 
-            Dim accessibleMembers = memberGroup.Where(Function(m) m.IsAccessibleWithin(within, throughType:=throughType)).ToList()
-            If accessibleMembers.Count = 0 Then
+            Return memberGroup.Where(Function(m) m.IsAccessibleWithin(within, throughType)).ToImmutableArray()
+        End Function
+
+        Private Function GetMemberGroupItems(accessibleMembers As ImmutableArray(Of ISymbol),
+                                             document As Document,
+                                             invocationExpression As InvocationExpressionSyntax,
+                                             semanticModel As SemanticModel,
+                                             cancellationToken As CancellationToken) As IEnumerable(Of SignatureHelpItem)
+            If accessibleMembers.Length = 0 Then
                 Return SpecializedCollections.EmptyEnumerable(Of SignatureHelpItem)()
             End If
 

src/Features/VisualBasic/Portable/SignatureHelp/InvocationExpressionSignatureHelpProvider.vb

@@ -33,9 +33,9 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.SignatureHelp
         Public Overrides Function GetCurrentArgumentState(root As SyntaxNode, position As Integer, syntaxFacts As ISyntaxFactsService, currentSpan As TextSpan, cancellationToken As CancellationToken) As SignatureHelpState
             Dim expression As InvocationExpressionSyntax = Nothing
             If TryGetInvocationExpression(root, position, syntaxFacts, SignatureHelpTriggerReason.InvokeSignatureHelpCommand, cancellationToken, expression) AndAlso
-                currentSpan.Start = SignatureHelpUtilities.GetSignatureHelpSpan(expression.ArgumentList).Start Then
+                currentSpan.Start = GetSignatureHelpSpan(expression.ArgumentList).Start Then
 
-                Return SignatureHelpUtilities.GetSignatureHelpState(expression.ArgumentList, position)
+                Return GetSignatureHelpState(expression.ArgumentList, position)
             End If
 
             Return Nothing
@@ -116,8 +116,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.SignatureHelp
             Dim documentationCommentFormattingService = document.GetLanguageService(Of IDocumentationCommentFormattingService)()
 
             Dim items = New List(Of SignatureHelpItem)
+            Dim accessibleMembers = New ImmutableArray(Of ISymbol)
             If memberGroup.Length > 0 Then
-                items.AddRange(GetMemberGroupItems(document, invocationExpression, semanticModel, within, memberGroup, cancellationToken))
+                accessibleMembers = GetAccessibleMembers(invocationExpression, semanticModel, within, memberGroup, cancellationToken)
+                items.AddRange(GetMemberGroupItems(accessibleMembers, document, invocationExpression, semanticModel, cancellationToken))
             End If
 
             If expressionType.IsDelegateType() Then
@@ -128,10 +130,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.SignatureHelp
                 items.AddRange(GetElementAccessItems(targetExpression, semanticModel, symbolDisplayService, anonymousTypeDisplayService, documentationCommentFormattingService, within, defaultProperties, cancellationToken))
             End If
 
-            Dim textSpan = SignatureHelpUtilities.GetSignatureHelpSpan(invocationExpression.ArgumentList)
+            Dim textSpan = GetSignatureHelpSpan(invocationExpression.ArgumentList)
             Dim syntaxFacts = document.GetLanguageService(Of ISyntaxFactsService)
 
-            Dim selectedItem = TryGetSelectedIndex(memberGroup, symbolInfo)
+            Dim selectedItem = TryGetSelectedIndex(accessibleMembers, symbolInfo)
             Return CreateSignatureHelpItems(items, textSpan, GetCurrentArgumentState(root, position, syntaxFacts, textSpan, cancellationToken), selectedItem)
         End Function
     End Class