Use api

src/libraries/System.Text.RegularExpressions/gen/RegexGenerator.Parser.cs

@@ -1,58 +1,30 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.CSharp.Syntax;
-using Microsoft.CodeAnalysis.DotnetRuntime.Extensions;
-using System;
-using System.Collections;
-using System.Collections.Generic;
 using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Globalization;
 using System.Linq;
 using System.Threading;
 
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.DotnetRuntime.Extensions;
+
 namespace System.Text.RegularExpressions.Generator
 {
     public partial class RegexGenerator
     {
         private const string RegexName = "System.Text.RegularExpressions.Regex";
         private const string RegexGeneratorAttributeName = "System.Text.RegularExpressions.RegexGeneratorAttribute";
 
-        private static bool IsSyntaxTargetForGeneration(SyntaxNode node, CancellationToken cancellationToken) =>
-            // We don't have a semantic model here, so the best we can do is say whether there are any attributes.
-            node is MethodDeclarationSyntax { AttributeLists: { Count: > 0 } };
-
-        private static bool IsSemanticTargetForGeneration(SemanticModel semanticModel, MethodDeclarationSyntax methodDeclarationSyntax, CancellationToken cancellationToken)
-        {
-            foreach (AttributeListSyntax attributeListSyntax in methodDeclarationSyntax.AttributeLists)
-            {
-                foreach (AttributeSyntax attributeSyntax in attributeListSyntax.Attributes)
-                {
-                    if (semanticModel.GetSymbolInfo(attributeSyntax, cancellationToken).Symbol is IMethodSymbol attributeSymbol &&
-                        attributeSymbol.ContainingType.ToDisplayString() == RegexGeneratorAttributeName)
-                    {
-                        return true;
-                    }
-                }
-            }
-
-            return false;
-        }
-
         // Returns null if nothing to do, Diagnostic if there's an error to report, or RegexType if the type was analyzed successfully.
-        private static object? GetSemanticTargetForGeneration(GeneratorSyntaxContext context, CancellationToken cancellationToken)
+        private static object? GetSemanticTargetForGeneration(
+            GeneratorAttributeSyntaxContext context, CancellationToken cancellationToken)
         {
-            var methodSyntax = (MethodDeclarationSyntax)context.Node;
+            var methodSyntax = (MethodDeclarationSyntax)context.TargetNode;
             SemanticModel sm = context.SemanticModel;
 
-            if (!IsSemanticTargetForGeneration(sm, methodSyntax, cancellationToken))
-            {
-                return null;
-            }
-
             Compilation compilation = sm.Compilation;
             INamedTypeSymbol? regexSymbol = compilation.GetBestTypeByMetadataName(RegexName);
             INamedTypeSymbol? regexGeneratorAttributeSymbol = compilation.GetBestTypeByMetadataName(RegexGeneratorAttributeName);
@@ -69,7 +41,7 @@ private static bool IsSemanticTargetForGeneration(SemanticModel semanticModel, M
                 return null;
             }
 
-            IMethodSymbol? regexMethodSymbol = sm.GetDeclaredSymbol(methodSyntax, cancellationToken) as IMethodSymbol;
+            IMethodSymbol regexMethodSymbol = context.TargetSymbol as IMethodSymbol;
             if (regexMethodSymbol is null)
             {
                 return null;