C#: Fix merge conflicts. Unfortunately, the type of symbolEntityCache needed to be the same as objectEntityCache to fix nullability warnings.

calumgrant · hvitved · commit aa9926901595 · 2020-09-02T10:52:04.000+02:00
diff --git a/csharp/extractor/Semmle.Extraction/Context.cs b/csharp/extractor/Semmle.Extraction/Context.cs
@@ -75,7 +75,7 @@ public Entity CreateEntityFromSymbol<Type, Entity>(ICachedEntityFactory<Type, En
             where Entity : ICachedEntity
             where Type : ISymbol
         {
-            return init == null ? CreateEntity2(factory, init) : CreateNonNullEntity(factory, init);
+            return init == null ? CreateEntity2(factory, init) : CreateNonNullEntity(factory, init, symbolEntityCache);
         }
 
         // A recursion guard against writing to the trap file whilst writing an id to the trap file.
@@ -161,11 +161,11 @@ private void CheckEntityHasUniqueLabel(string id, ICachedEntity entity)
 
         public Entity CreateNonNullEntity<Type, Entity>(ICachedEntityFactory<Type, Entity> factory, Type init)
             where Entity : ICachedEntity
+            where Type : notnull
             => CreateNonNullEntity(factory, init, objectEntityCache);
 
-        private Entity CreateNonNullEntity<Type, Src, Entity>(ICachedEntityFactory<Type, Entity> factory, Type init, IDictionary<Src, ICachedEntity> dictionary)
+        private Entity CreateNonNullEntity<Type, Entity>(ICachedEntityFactory<Type, Entity> factory, Type init, IDictionary<object, ICachedEntity> dictionary)
             where Entity : ICachedEntity
-            where Type : Src
         {
             if (init is null) throw new ArgumentException("Unexpected null value", nameof(init));
 
@@ -233,8 +233,18 @@ public void AddFreshLabel(IEntity entity)
         readonly Dictionary<string, ICachedEntity> idLabelCache = new Dictionary<string, ICachedEntity>();
 #endif
 
+        // Adaptor to convert IEqualityComparer<ISymbol> to IEqualityComparer<object>
+        class SymbolComparer : IEqualityComparer<object>
+        {
+            IEqualityComparer<ISymbol> comparer = SymbolEqualityComparer.IncludeNullability;
+
+            bool IEqualityComparer<object>.Equals(object? x, object? y) => comparer.Equals(x as ISymbol, y as ISymbol);
+
+            int IEqualityComparer<object>.GetHashCode(object obj) => comparer.GetHashCode((ISymbol)obj);
+        }
+
         readonly IDictionary<object, ICachedEntity> objectEntityCache = new Dictionary<object, ICachedEntity>();
-        readonly IDictionary<ISymbol, ICachedEntity> symbolEntityCache = new Dictionary<ISymbol, ICachedEntity>(10000, SymbolEqualityComparer.IncludeNullability);
+        readonly IDictionary<object, ICachedEntity> symbolEntityCache = new Dictionary<object, ICachedEntity>(10000, new SymbolComparer());
         readonly Dictionary<ICachedEntity, Label> entityLabelCache = new Dictionary<ICachedEntity, Label>();
         readonly HashSet<Label> extractedGenerics = new HashSet<Label>();
 
