C#: Improve db consistency by removing assembly id

csharp/extractor/Semmle.Extraction.CSharp/Entities/Accessor.cs

@@ -77,7 +77,7 @@ public override void Populate(TextWriter trapFile)
         }
 
         public new static Accessor Create(Context cx, IMethodSymbol symbol) =>
-            AccessorFactory.Instance.CreateEntity(cx, symbol);
+            AccessorFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class AccessorFactory : ICachedEntityFactory<IMethodSymbol, Accessor>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Constructor.cs

@@ -104,7 +104,7 @@ ConstructorDeclarationSyntax Syntax
             {
                 case MethodKind.StaticConstructor:
                 case MethodKind.Constructor:
-                    return ConstructorFactory.Instance.CreateEntity(cx, constructor);
+                    return ConstructorFactory.Instance.CreateEntityFromSymbol(cx, constructor);
                 default:
                     throw new InternalError(constructor, "Attempt to create a Constructor from a symbol that isn't a constructor");
             }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Conversion.cs

@@ -11,7 +11,7 @@ class Conversion : UserOperator
             : base(cx, init) { }
 
         public new static Conversion Create(Context cx, IMethodSymbol symbol) =>
-            ConversionFactory.Instance.CreateEntity(cx, symbol);
+            ConversionFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Destructor.cs

@@ -24,7 +24,7 @@ public override void Populate(TextWriter trapFile)
         }
 
         public new static Destructor Create(Context cx, IMethodSymbol symbol) =>
-            DestructorFactory.Instance.CreateEntity(cx, symbol);
+            DestructorFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class DestructorFactory : ICachedEntityFactory<IMethodSymbol, Destructor>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Event.cs

@@ -60,7 +60,7 @@ public override void Populate(TextWriter trapFile)
                 TypeMention.Create(Context, syntaxType, this, type);
         }
 
-        public static Event Create(Context cx, IEventSymbol symbol) => EventFactory.Instance.CreateEntity(cx, symbol);
+        public static Event Create(Context cx, IEventSymbol symbol) => EventFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class EventFactory : ICachedEntityFactory<IEventSymbol, Event>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/EventAccessor.cs

@@ -53,7 +53,7 @@ public override void Populate(TextWriter trapFile)
         }
 
         public new static EventAccessor Create(Context cx, IMethodSymbol symbol) =>
-            EventAccessorFactory.Instance.CreateEntity(cx, symbol);
+            EventAccessorFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class EventAccessorFactory : ICachedEntityFactory<IMethodSymbol, EventAccessor>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Field.cs

@@ -18,7 +18,7 @@ class Field : CachedSymbol<IFieldSymbol>, IExpressionParentEntity
             type = new Lazy<AnnotatedType>(() => Entities.Type.Create(cx, symbol.GetAnnotatedType()));
         }
 
-        public static Field Create(Context cx, IFieldSymbol field) => FieldFactory.Instance.CreateEntity(cx, field);
+        public static Field Create(Context cx, IFieldSymbol field) => FieldFactory.Instance.CreateEntityFromSymbol(cx, field);
 
         // Do not populate backing fields.
         // Populate Tuple fields.

csharp/extractor/Semmle.Extraction.CSharp/Entities/Indexer.cs

@@ -71,7 +71,7 @@ public override void Populate(TextWriter trapFile)
                 TypeMention.Create(Context, syntax.Type, this, type);
         }
 
-        public static new Indexer Create(Context cx, IPropertySymbol prop) => IndexerFactory.Instance.CreateEntity(cx, prop);
+        public static new Indexer Create(Context cx, IPropertySymbol prop) => IndexerFactory.Instance.CreateEntityFromSymbol(cx, prop);
 
         public override void WriteId(TextWriter trapFile)
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/LocalFunction.cs

@@ -22,7 +22,7 @@ public override void WriteQuotedId(TextWriter trapFile)
             trapFile.Write('*');
         }
 
-        public static new LocalFunction Create(Context cx, IMethodSymbol field) => LocalFunctionFactory.Instance.CreateEntity(cx, field);
+        public static new LocalFunction Create(Context cx, IMethodSymbol field) => LocalFunctionFactory.Instance.CreateEntityFromSymbol(cx, field);
 
         class LocalFunctionFactory : ICachedEntityFactory<IMethodSymbol, LocalFunction>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/LocalVariable.cs

@@ -43,7 +43,7 @@ symbol is ILocalSymbol l ?
 
         public static LocalVariable Create(Context cx, ISymbol local)
         {
-            return LocalVariableFactory.Instance.CreateEntity(cx, local);
+            return LocalVariableFactory.Instance.CreateEntityFromSymbol(cx, local);
         }
 
         void DefineConstantValue(TextWriter trapFile)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs

@@ -129,7 +129,7 @@ protected static void BuildMethodId(Method m, TextWriter trapFile)
                     // Type arguments with different nullability can result in 
                     // a constructed method with different nullability of its parameters and return type,
                     // so we need to create a distinct database entity for it.
-                    trapFile.BuildList(",", m.symbol.GetAnnotatedTypeArguments(), (ta, tb0) => { AddSignatureTypeToId(m.Context, tb0, m.symbol, ta.Symbol); trapFile.Write((int)ta.Nullability); });
+                    trapFile.BuildList(",", m.symbol.GetAnnotatedTypeArguments(), (ta, tb0) => { ta.Symbol.BuildNestedTypeId(m.Context, tb0, m.symbol); trapFile.Write((int)ta.Nullability); });
                     trapFile.Write('>');
                 }
             }
@@ -163,50 +163,6 @@ public override void WriteId(TextWriter trapFile)
             BuildMethodId(this, trapFile);
         }
 
-        /// <summary>
-        /// Adds an appropriate label ID to the trap builder <paramref name="trapFile"/>
-        /// for the type <paramref name="type"/> belonging to the signature of method
-        /// <paramref name="method"/>.
-        ///
-        /// For methods without type parameters this will always add the key of the
-        /// corresponding type.
-        ///
-        /// For methods with type parameters, this will add the key of the
-        /// corresponding type if the type does *not* contain one of the method
-        /// type parameters, otherwise it will add a textual representation of
-        /// the type. This distinction is required because type parameter IDs
-        /// refer to their declaring methods.
-        ///
-        /// Example:
-        ///
-        /// <code>
-        /// int Count&lt;T&gt;(IEnumerable<T> items)
-        /// </code>
-        ///
-        /// The label definitions for <code>Count</code> (<code>#4</code>) and <code>T</code>
-        /// (<code>#5</code>) will look like:
-        ///
-        /// <code>
-        /// #1=&lt;label for System.Int32&gt;
-        /// #2=&lt;label for type containing Count&gt;
-        /// #3=&lt;label for IEnumerable`1&gt;
-        /// #4=@"{#1} {#2}.Count`2(#3<T>);method"
-        /// #5=@"{#4}T;typeparameter"
-        /// </code>
-        ///
-        /// Note how <code>int</code> is referenced in the label definition <code>#3</code> for
-        /// <code>Count</code>, while <code>T[]</code> is represented textually in order
-        /// to make the reference to <code>#3</code> in the label definition <code>#4</code> for
-        /// <code>T</code> valid.
-        /// </summary>
-        protected static void AddSignatureTypeToId(Context cx, TextWriter trapFile, IMethodSymbol method, ITypeSymbol type)
-        {
-            if (type.ContainsTypeParameters(cx, method))
-                type.BuildTypeId(cx, trapFile, (cx0, tb0, type0) => AddSignatureTypeToId(cx, tb0, method, type0));
-            else
-                trapFile.WriteSubId(Type.Create(cx, type));
-        }
-
         protected static void AddParametersToId(Context cx, TextWriter trapFile, IMethodSymbol method)
         {
             trapFile.Write('(');
@@ -215,13 +171,13 @@ protected static void AddParametersToId(Context cx, TextWriter trapFile, IMethod
             if (method.MethodKind == MethodKind.ReducedExtension)
             {
                 trapFile.WriteSeparator(",", ref index);
-                AddSignatureTypeToId(cx, trapFile, method, method.ReceiverType);
+                method.ReceiverType.BuildNestedTypeId(cx, trapFile, method);
             }
 
             foreach (var param in method.Parameters)
             {
                 trapFile.WriteSeparator(",", ref index);
-                AddSignatureTypeToId(cx, trapFile, method, param.Type);
+                param.Type.BuildNestedTypeId(cx, trapFile, method);
                 switch (param.RefKind)
                 {
                     case RefKind.Out:
@@ -244,9 +200,10 @@ protected static void AddParametersToId(Context cx, TextWriter trapFile, IMethod
 
         public static void AddExplicitInterfaceQualifierToId(Context cx, System.IO.TextWriter trapFile, IEnumerable<ISymbol> explicitInterfaceImplementations)
         {
-            if (explicitInterfaceImplementations.Any())
+            foreach (var i in explicitInterfaceImplementations)
             {
-                trapFile.AppendList(",", explicitInterfaceImplementations.Select(impl => cx.CreateEntity(impl.ContainingType)));
+                trapFile.Write(';');
+                i.ContainingType.BuildNestedTypeId(cx, trapFile, null);
             }
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/OrdinaryMethod.cs

@@ -49,7 +49,7 @@ public override void Populate(TextWriter trapFile)
             ExtractCompilerGenerated(trapFile);
         }
 
-        public new static OrdinaryMethod Create(Context cx, IMethodSymbol method) => OrdinaryMethodFactory.Instance.CreateEntity(cx, method);
+        public new static OrdinaryMethod Create(Context cx, IMethodSymbol method) => OrdinaryMethodFactory.Instance.CreateEntityFromSymbol(cx, method);
 
         class OrdinaryMethodFactory : ICachedEntityFactory<IMethodSymbol, OrdinaryMethod>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Property.cs

@@ -113,7 +113,7 @@ public static Property Create(Context cx, IPropertySymbol prop)
         {
             bool isIndexer = prop.IsIndexer || prop.Parameters.Any();
 
-            return isIndexer ? Indexer.Create(cx, prop) : PropertyFactory.Instance.CreateEntity(cx, prop);
+            return isIndexer ? Indexer.Create(cx, prop) : PropertyFactory.Instance.CreateEntityFromSymbol(cx, prop);
         }
 
         public void VisitDeclaration(Context cx, PropertyDeclarationSyntax p)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/ArrayType.cs

@@ -36,7 +36,7 @@ public override void WriteId(TextWriter trapFile)
             trapFile.Write(";type");
         }
 
-        public static ArrayType Create(Context cx, IArrayTypeSymbol symbol) => ArrayTypeFactory.Instance.CreateEntity(cx, symbol);
+        public static ArrayType Create(Context cx, IArrayTypeSymbol symbol) => ArrayTypeFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class ArrayTypeFactory : ICachedEntityFactory<IArrayTypeSymbol, ArrayType>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/DynamicType.cs

@@ -9,7 +9,7 @@ class DynamicType : Type<IDynamicTypeSymbol>
         DynamicType(Context cx, IDynamicTypeSymbol init)
             : base(cx, init) { }
 
-        public static DynamicType Create(Context cx, IDynamicTypeSymbol type) => DynamicTypeFactory.Instance.CreateEntity(cx, type);
+        public static DynamicType Create(Context cx, IDynamicTypeSymbol type) => DynamicTypeFactory.Instance.CreateEntityFromSymbol(cx, type);
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation => Context.Compilation.ObjectType.Locations.FirstOrDefault();
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/NamedType.cs

@@ -17,7 +17,7 @@ class NamedType : Type<INamedTypeSymbol>
             typeArgumentsLazy = new Lazy<Type[]>(() => symbol.TypeArguments.Select(t => Create(cx, t)).ToArray());
         }
 
-        public static NamedType Create(Context cx, INamedTypeSymbol type) => NamedTypeFactory.Instance.CreateEntity(cx, type);
+        public static NamedType Create(Context cx, INamedTypeSymbol type) => NamedTypeFactory.Instance.CreateEntityFromSymbol(cx, type);
 
         public override bool NeedsPopulation => base.NeedsPopulation || symbol.TypeKind == TypeKind.Error;
 
@@ -29,7 +29,8 @@ public override void Populate(TextWriter trapFile)
                 return;
             }
 
-            trapFile.typeref_type((NamedTypeRef)TypeRef, this);
+            if (UsesTypeRef)
+                trapFile.typeref_type((NamedTypeRef)TypeRef, this);
 
             if (symbol.IsGenericType)
             {
@@ -108,7 +109,7 @@ public override IEnumerable<Extraction.Entities.Location> Locations
 
         public override void WriteId(TextWriter trapFile)
         {
-            symbol.BuildTypeId(Context, trapFile, (cx0, tb0, sub) => tb0.WriteSubId(Create(cx0, sub)));
+            symbol.BuildTypeId(Context, trapFile, true, symbol, (cx0, tb0, sub, _) => tb0.WriteSubId(Create(cx0, sub)));
             trapFile.Write(";type");
         }
 
@@ -148,7 +149,14 @@ class NamedTypeFactory : ICachedEntityFactory<INamedTypeSymbol, NamedType>
             public NamedType Create(Context cx, INamedTypeSymbol init) => new NamedType(cx, init);
         }
 
-        public override Type TypeRef => NamedTypeRef.Create(Context, symbol);
+        // Do not create typerefs of constructed generics as they are always in the current trap file, and there is a possibility
+        // that a generic could make the typedef ambiguous which leads to performance problems in QL.
+        // Create typerefs for constructed error types in case they are fully defined elsewhere.
+        // We cannot use `!this.NeedsPopulation` because this would not be stable as it would depend on
+        // the assembly that was being extracted at the time.
+        bool UsesTypeRef => symbol.TypeKind == TypeKind.Error || SymbolEqualityComparer.Default.Equals(symbol.OriginalDefinition, symbol);
+
+        public override Type TypeRef => UsesTypeRef ? (Type)NamedTypeRef.Create(Context, symbol) : this;
     }
 
     class NamedTypeRef : Type<INamedTypeSymbol>
@@ -174,7 +182,7 @@ class NamedTypeRefFactory : ICachedEntityFactory<INamedTypeSymbol, NamedTypeRef>
 
         public override void WriteId(TextWriter trapFile)
         {
-            trapFile.WriteSubId(referencedType);
+            referencedType.symbol.BuildNestedTypeId(Context, trapFile, referencedType.symbol);
             trapFile.Write(";typeRef");
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/PointerType.cs

@@ -29,7 +29,7 @@ public override void Populate(TextWriter trapFile)
 
         public Type PointedAtType { get; private set; }
 
-        public static PointerType Create(Context cx, IPointerTypeSymbol symbol) => PointerTypeFactory.Instance.CreateEntity(cx, symbol);
+        public static PointerType Create(Context cx, IPointerTypeSymbol symbol) => PointerTypeFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class PointerTypeFactory : ICachedEntityFactory<IPointerTypeSymbol, PointerType>
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/TupleType.cs

@@ -13,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities
     /// </summary>
     class TupleType : Type<INamedTypeSymbol>
     {
-        public static TupleType Create(Context cx, INamedTypeSymbol type) => TupleTypeFactory.Instance.CreateEntity(cx, type);
+        public static TupleType Create(Context cx, INamedTypeSymbol type) => TupleTypeFactory.Instance.CreateEntityFromSymbol(cx, type);
 
         class TupleTypeFactory : ICachedEntityFactory<INamedTypeSymbol, TupleType>
         {
@@ -32,7 +32,7 @@ class TupleTypeFactory : ICachedEntityFactory<INamedTypeSymbol, TupleType>
 
         public override void WriteId(TextWriter trapFile)
         {
-            symbol.BuildTypeId(Context, trapFile, (cx0, tb0, sub) => tb0.WriteSubId(Create(cx0, sub)));
+            symbol.BuildTypeId(Context, trapFile, false, symbol, (cx0, tb0, sub, _) => tb0.WriteSubId(Create(cx0, sub)));
             trapFile.Write(";tuple");
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs

@@ -324,6 +324,14 @@ public virtual IEnumerable<Type> TypeMentions
         }
 
         public override TrapStackBehaviour TrapStackBehaviour => TrapStackBehaviour.NoLabel;
+
+        public override bool Equals(object obj)
+        {
+            var other = obj as Type;
+            return other?.GetType() == GetType() && SymbolEqualityComparer.IncludeNullability.Equals(other.symbol, symbol);
+        }
+
+        public override int GetHashCode() => SymbolEqualityComparer.IncludeNullability.GetHashCode(symbol);
     }
 
     abstract class Type<T> : Type where T : ITypeSymbol

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/TypeParameter.cs

@@ -88,7 +88,7 @@ public override void Populate(TextWriter trapFile)
         }
 
         static public TypeParameter Create(Context cx, ITypeParameterSymbol p) =>
-            TypeParameterFactory.Instance.CreateEntity(cx, p);
+            TypeParameterFactory.Instance.CreateEntityFromSymbol(cx, p);
 
         /// <summary>
         /// The variance of this type parameter.

csharp/extractor/Semmle.Extraction.CSharp/Entities/UserOperator.cs

@@ -51,7 +51,7 @@ public override Type ContainingType
 
         public override void WriteId(TextWriter trapFile)
         {
-            AddSignatureTypeToId(Context, trapFile, symbol, symbol.ReturnType); // Needed for op_explicit(), which differs only by return type.
+            symbol.ReturnType.BuildNestedTypeId(Context, trapFile, symbol); // Needed for op_explicit(), which differs only by return type.
             trapFile.Write(' ');
             BuildMethodId(this, trapFile);
         }
@@ -190,7 +190,7 @@ public static string OperatorSymbol(Context cx, string methodName)
             return result;
         }
 
-        public new static UserOperator Create(Context cx, IMethodSymbol symbol) => UserOperatorFactory.Instance.CreateEntity(cx, symbol);
+        public new static UserOperator Create(Context cx, IMethodSymbol symbol) => UserOperatorFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
         class UserOperatorFactory : ICachedEntityFactory<IMethodSymbol, UserOperator>
         {