Extensions: DocumentationCommentId and

ExtensionGroupingName/ExtensionMarkerName APIs

Author: jcouv

docs/contributing/Compiler Test Plan.md

@@ -9,7 +9,7 @@ This document provides guidance for thinking about language interactions and tes
 - BCL (including mono) and other customer impact
 - Determinism
 - Loading from metadata (source vs. loaded from metadata)
-- Public interface of compiler APIs (including semantic model APIs listed below):
+- Public compiler APIs (including semantic model and other APIs listed below):
     - GetDeclaredSymbol 
     - GetEnclosingSymbol 
     - GetSymbolInfo 
@@ -29,6 +29,7 @@ This document provides guidance for thinking about language interactions and tes
     - ClassifyConversion
     - GetOperation (`IOperation`)
     - GetCFG (`ControlFlowGraph`)
+    - DocumentationCommentId APIs
 - VB/F# interop
 - C++/CLI interop (particularly for metadata format changes, e.g. DIMs, static abstracts in interfaces, or generic attributes)
 - Performance and stress testing

src/Compilers/CSharp/Portable/Binder/Semantics/Operators/UnaryOperatorOverloadResolution.cs

@@ -263,6 +263,7 @@ public bool Equals(MethodSymbol? x, MethodSymbol? y)
 
                 var xExtension = x.OriginalDefinition.ContainingType;
                 var xGroupingKey = ((SourceNamedTypeSymbol)xExtension).ExtensionGroupingName;
+                Debug.Assert(xGroupingKey is not null);
                 var yExtension = y.OriginalDefinition.ContainingType;
                 var yGroupingKey = ((SourceNamedTypeSymbol)yExtension).ExtensionGroupingName;
 
@@ -294,6 +295,7 @@ public int GetHashCode(MethodSymbol op)
 
                 var extension = op.OriginalDefinition.ContainingType;
                 var groupingKey = ((SourceNamedTypeSymbol)extension).ExtensionGroupingName;
+                Debug.Assert(groupingKey is not null);
                 result = Hash.Combine(result, groupingKey.GetHashCode());
 
                 foreach (var parameter in op.OriginalDefinition.AsMember(Normalize(extension)).Parameters)

src/Compilers/CSharp/Portable/SymbolDisplay/SymbolDisplayVisitor.Types.cs

@@ -345,9 +345,7 @@ private void AddNameAndTypeArgumentsOrParameters(INamedTypeSymbol symbol)
             {
                 if (Format.CompilerInternalOptions.HasFlag(SymbolDisplayCompilerInternalOptions.UseMetadataMemberNames))
                 {
-                    // Tracked by https://github.com/dotnet/roslyn/issues/78957 : public API, should we output ExtensionMarkerName instead here?
-                    var extensionIdentifier = underlyingTypeSymbol!.ExtensionGroupingName; // Tracked by https://github.com/dotnet/roslyn/issues/78957 : public API, use public API once it's available
-                    Builder.Add(CreatePart(SymbolDisplayPartKind.ClassName, symbol, extensionIdentifier));
+                    Builder.Add(CreatePart(SymbolDisplayPartKind.ClassName, symbol, symbol.ExtensionGroupingName));
                 }
                 else
                 {

src/Compilers/CSharp/Portable/Symbols/AnonymousTypes/PublicSymbols/AnonymousManager.TypeOrDelegatePublicSymbol.cs

@@ -82,11 +82,9 @@ internal sealed override bool MangleName
             internal sealed override bool IsFileLocal => false;
             internal sealed override FileIdentifier? AssociatedFileIdentifier => null;
 
-            internal override string ExtensionGroupingName
-                => throw ExceptionUtilities.Unreachable();
+            internal sealed override string? ExtensionGroupingName => null;
 
-            internal override string ExtensionMarkerName
-                => throw ExceptionUtilities.Unreachable();
+            internal sealed override string? ExtensionMarkerName => null;
 
             public sealed override int Arity
             {

src/Compilers/CSharp/Portable/Symbols/AnonymousTypes/SynthesizedSymbols/AnonymousType.TypeOrDelegateTemplateSymbol.cs

@@ -167,11 +167,9 @@ public sealed override bool IsRefLikeType
                 get { return false; }
             }
 
-            internal override string ExtensionGroupingName
-                => throw ExceptionUtilities.Unreachable();
+            internal sealed override string? ExtensionGroupingName => null;
 
-            internal override string ExtensionMarkerName
-                => throw ExceptionUtilities.Unreachable();
+            internal sealed override string? ExtensionMarkerName => null;
 
             public sealed override bool IsReadOnly
             {

src/Compilers/CSharp/Portable/Symbols/ArrayTypeSymbol.cs

@@ -237,6 +237,8 @@ public override bool IsValueType
         }
 
         internal sealed override ParameterSymbol? ExtensionParameter => null;
+        internal sealed override string? ExtensionGroupingName => null;
+        internal sealed override string? ExtensionMarkerName => null;
 
         internal sealed override ManagedKind GetManagedKind(ref CompoundUseSiteInfo<AssemblySymbol> useSiteInfo) => ManagedKind.Managed;
 

src/Compilers/CSharp/Portable/Symbols/DynamicTypeSymbol.cs

@@ -108,6 +108,8 @@ public override bool IsValueType
         }
 
         internal sealed override ParameterSymbol? ExtensionParameter => null;
+        internal sealed override string? ExtensionGroupingName => null;
+        internal sealed override string? ExtensionMarkerName => null;
 
         internal sealed override ManagedKind GetManagedKind(ref CompoundUseSiteInfo<AssemblySymbol> useSiteInfo) => ManagedKind.Managed;
 

src/Compilers/CSharp/Portable/Symbols/ErrorTypeSymbol.cs

@@ -116,11 +116,9 @@ public sealed override bool IsRefLikeType
             }
         }
 
-        internal sealed override string ExtensionGroupingName
-            => throw ExceptionUtilities.Unreachable();
+        internal sealed override string? ExtensionGroupingName => null;
 
-        internal sealed override string ExtensionMarkerName
-            => throw ExceptionUtilities.Unreachable();
+        internal sealed override string? ExtensionMarkerName => null;
 
         public sealed override bool IsReadOnly
         {

src/Compilers/CSharp/Portable/Symbols/FunctionPointers/FunctionPointerTypeSymbol.cs

@@ -74,6 +74,8 @@ private FunctionPointerTypeSymbol(FunctionPointerMethodSymbol signature)
         public override bool IsReferenceType => false;
         public override bool IsValueType => true;
         internal sealed override ParameterSymbol? ExtensionParameter => null;
+        internal sealed override string? ExtensionGroupingName => null;
+        internal sealed override string? ExtensionMarkerName => null;
         public override TypeKind TypeKind => TypeKind.FunctionPointer;
         public override bool IsRefLikeType => false;
         public override bool IsReadOnly => false;

src/Compilers/CSharp/Portable/Symbols/FunctionTypeSymbol.cs

@@ -100,6 +100,8 @@ internal void SetExpression(BoundExpression expression)
         public override bool IsValueType => false;
 
         internal sealed override ParameterSymbol? ExtensionParameter => null;
+        internal sealed override string? ExtensionGroupingName => null;
+        internal sealed override string? ExtensionMarkerName => null;
 
         public override TypeKind TypeKind => TypeKindInternal.FunctionType;