Revert "Revert "Merge pull request #7510 from CyrusNajmabadi/analysisSpeedup""

src/Features/CSharp/Portable/InvokeDelegateWithConditionalAccess/InvokeDelegateWithConditionalAccessAnalyzer.cs

@@ -2,6 +2,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Threading;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Text;
@@ -15,8 +16,8 @@ internal static class Constants
         public const string SingleIfStatementForm = nameof(SingleIfStatementForm);
     }
 
-    //[DiagnosticAnalyzer(LanguageNames.CSharp)]
-    internal class InvokeDelegateWithConditionalAccessAnalyzer : DiagnosticAnalyzer
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    internal class InvokeDelegateWithConditionalAccessAnalyzer : DiagnosticAnalyzer, IBuiltInAnalyzer
     {
         private static readonly DiagnosticDescriptor s_descriptor = new DiagnosticDescriptor(
             IDEDiagnosticIds.InvokeDelegateWithConditionalAccessId,
@@ -91,6 +92,8 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
             ExpressionStatementSyntax expressionStatement,
             InvocationExpressionSyntax invocationExpression)
         {
+            var cancellationToken = syntaxContext.CancellationToken;
+
             // Look for the form:  "if (someExpr != null) someExpr()"
             if (condition.Left.IsKind(SyntaxKind.NullLiteralExpression) ||
                 condition.Right.IsKind(SyntaxKind.NullLiteralExpression))
@@ -99,8 +102,11 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
                     ? condition.Right
                     : condition.Left;
 
+                cancellationToken.ThrowIfCancellationRequested();
                 if (SyntaxFactory.AreEquivalent(expr, invocationExpression.Expression, topLevel: false))
                 {
+                    cancellationToken.ThrowIfCancellationRequested();
+
                     // Looks good!
                     var tree = syntaxContext.SemanticModel.SyntaxTree;
                     var additionalLocations = new List<Location>
@@ -136,6 +142,9 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
             ExpressionStatementSyntax expressionStatement,
             InvocationExpressionSyntax invocationExpression)
         {
+            var cancellationToken = syntaxContext.CancellationToken;
+            cancellationToken.ThrowIfCancellationRequested();
+
             // look for the form "if (a != null)" or "if (null != a)"
             if (!ifStatement.Parent.IsKind(SyntaxKind.Block))
             {
@@ -192,6 +201,7 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
                 return false;
             }
 
+            cancellationToken.ThrowIfCancellationRequested();
             if (!Equals(declarator.Identifier.ValueText, conditionName.Identifier.ValueText))
             {
                 return false;
@@ -199,7 +209,7 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
 
             // Syntactically this looks good.  Now make sure that the local is a delegate type.
             var semanticModel = syntaxContext.SemanticModel;
-            var localSymbol = (ILocalSymbol)semanticModel.GetDeclaredSymbol(declarator);
+            var localSymbol = (ILocalSymbol)semanticModel.GetDeclaredSymbol(declarator, cancellationToken);
 
             // Ok, we made a local just to check it for null and invoke it.  Looks like something
             // we can suggest an improvement for!
@@ -237,5 +247,10 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
 
         private bool IsNullCheckExpression(ExpressionSyntax left, ExpressionSyntax right) =>
             left.IsKind(SyntaxKind.IdentifierName) && right.IsKind(SyntaxKind.NullLiteralExpression);
+
+        public DiagnosticAnalyzerCategory GetAnalyzerCategory()
+        {
+            return DiagnosticAnalyzerCategory.SemanticSpanAnalysis;
+        }
     }
 }
\ No newline at end of file

src/Features/CSharp/Portable/InvokeDelegateWithConditionalAccess/InvokeDelegateWithConditionalAccessCodeFixProvider.cs

@@ -18,7 +18,7 @@
 
 namespace Microsoft.CodeAnalysis.CSharp.InvokeDelegateWithConditionalAccess
 {
-    //[ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(InvokeDelegateWithConditionalAccessCodeFixProvider)), Shared]
+    [ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(InvokeDelegateWithConditionalAccessCodeFixProvider)), Shared]
     internal class InvokeDelegateWithConditionalAccessCodeFixProvider : CodeFixProvider
     {
         public override ImmutableArray<string> FixableDiagnosticIds { get; } = ImmutableArray.Create(IDEDiagnosticIds.InvokeDelegateWithConditionalAccessId);
@@ -45,23 +45,32 @@ private async Task<Document> UpdateDocumentAsync(CodeFixContext context)
 
             if (diagnostic.Properties[Constants.Kind] == Constants.VariableAndIfStatementForm)
             {
-                return HandVariableAndIfStatementFormAsync(document, root, diagnostic);
+                return HandVariableAndIfStatementFormAsync(document, root, diagnostic, cancellationToken);
             }
             else
             {
                 Debug.Assert(diagnostic.Properties[Constants.Kind] == Constants.SingleIfStatementForm);
-                return HandleSingleIfStatementForm(document, root, diagnostic);
+                return HandleSingleIfStatementForm(document, root, diagnostic, cancellationToken);
             }
         }
 
-        private Document HandleSingleIfStatementForm(Document document, SyntaxNode root, Diagnostic diagnostic)
+        private Document HandleSingleIfStatementForm(
+            Document document,
+            SyntaxNode root,
+            Diagnostic diagnostic,
+            CancellationToken cancellationToken)
         {
             var ifStatementLocation = diagnostic.AdditionalLocations[0];
             var expressionStatementLocation = diagnostic.AdditionalLocations[1];
 
             var ifStatement = (IfStatementSyntax)root.FindNode(ifStatementLocation.SourceSpan);
+            cancellationToken.ThrowIfCancellationRequested();
+
             var expressionStatement = (ExpressionStatementSyntax)root.FindNode(expressionStatementLocation.SourceSpan);
+            cancellationToken.ThrowIfCancellationRequested();
+
             var invocationExpression = (InvocationExpressionSyntax)expressionStatement.Expression;
+            cancellationToken.ThrowIfCancellationRequested();
 
             StatementSyntax newStatement = expressionStatement.WithExpression(
                 SyntaxFactory.ConditionalAccessExpression(
@@ -76,20 +85,27 @@ private Document HandleSingleIfStatementForm(Document document, SyntaxNode root,
             }
 
             newStatement = newStatement.WithAdditionalAnnotations(Formatter.Annotation);
+            cancellationToken.ThrowIfCancellationRequested();
 
             var newRoot = root.ReplaceNode(ifStatement, newStatement);
             return document.WithSyntaxRoot(newRoot);
         }
 
-        private static Document HandVariableAndIfStatementFormAsync(Document document, SyntaxNode root, Diagnostic diagnostic)
+        private static Document HandVariableAndIfStatementFormAsync(
+            Document document, SyntaxNode root, Diagnostic diagnostic, CancellationToken cancellationToken)
         {
             var localDeclarationLocation = diagnostic.AdditionalLocations[0];
             var ifStatementLocation = diagnostic.AdditionalLocations[1];
             var expressionStatementLocation = diagnostic.AdditionalLocations[2];
 
             var localDeclarationStatement = (LocalDeclarationStatementSyntax)root.FindNode(localDeclarationLocation.SourceSpan);
+            cancellationToken.ThrowIfCancellationRequested();
+
             var ifStatement = (IfStatementSyntax)root.FindNode(ifStatementLocation.SourceSpan);
+            cancellationToken.ThrowIfCancellationRequested();
+
             var expressionStatement = (ExpressionStatementSyntax)root.FindNode(expressionStatementLocation.SourceSpan);
+            cancellationToken.ThrowIfCancellationRequested();
 
             var invocationExpression = (InvocationExpressionSyntax)expressionStatement.Expression;
             var parentBlock = (BlockSyntax)localDeclarationStatement.Parent;
@@ -105,6 +121,7 @@ private static Document HandVariableAndIfStatementFormAsync(Document document, S
             var editor = new SyntaxEditor(root, document.Project.Solution.Workspace);
             editor.ReplaceNode(ifStatement, newStatement);
             editor.RemoveNode(localDeclarationStatement, SyntaxRemoveOptions.KeepLeadingTrivia | SyntaxRemoveOptions.AddElasticMarker);
+            cancellationToken.ThrowIfCancellationRequested();
 
             var newRoot = editor.GetChangedRoot();
             return document.WithSyntaxRoot(newRoot);