TypeProvider Optimizations

src/Draco.Compiler/Api/Compilation.cs

@@ -133,6 +133,11 @@ public static Compilation Create(
     /// </summary>
     internal WellKnownTypes WellKnownTypes { get; }
 
+    /// <summary>
+    /// The type provider used for metadata references.
+    /// </summary>
+    internal TypeProvider TypeProvider { get; }
+
     /// <summary>
     /// Intrinsicly defined symbols for the compilation.
     /// </summary>
@@ -153,6 +158,7 @@ private Compilation(
         ModuleSymbol? sourceModule = null,
         DeclarationTable? declarationTable = null,
         WellKnownTypes? wellKnownTypes = null,
+        TypeProvider? typeProvider = null,
         IntrinsicSymbols? intrinsicSymbols = null,
         BinderCache? binderCache = null)
     {
@@ -166,6 +172,7 @@ private Compilation(
         this.sourceModule = sourceModule;
         this.declarationTable = declarationTable;
         this.WellKnownTypes = wellKnownTypes ?? new WellKnownTypes(this);
+        this.TypeProvider = typeProvider ?? new TypeProvider(this);
         this.IntrinsicSymbols = intrinsicSymbols ?? new IntrinsicSymbols(this);
         this.binderCache = binderCache ?? new BinderCache(this);
     }

src/Draco.Compiler/Internal/Symbols/Metadata/MetadataFieldSymbol.cs

@@ -80,8 +80,7 @@ public MetadataFieldSymbol(Symbol containingSymbol, FieldDefinition fieldDefinit
     private TypeSymbol BuildType()
     {
         // Decode signature
-        var decoder = new TypeProvider(this.Assembly.Compilation);
-        return this.fieldDefinition.DecodeSignature(decoder, this);
+        return this.fieldDefinition.DecodeSignature(this.Assembly.Compilation.TypeProvider, this);
     }
 
     private object? BuildDefaultValue()

src/Draco.Compiler/Internal/Symbols/Metadata/MetadataMethodSymbol.cs

@@ -139,8 +139,7 @@ private ImmutableArray<TypeParameterSymbol> BuildGenericParameters()
     private void BuildSignature()
     {
         // Decode signature
-        var decoder = new TypeProvider(this.Assembly.Compilation);
-        var signature = this.methodDefinition.DecodeSignature(decoder, this);
+        var signature = this.methodDefinition.DecodeSignature(this.Assembly.Compilation.TypeProvider, this);
 
         // Build parameters
         var parameters = ImmutableArray.CreateBuilder<ParameterSymbol>();
@@ -194,7 +193,7 @@ private void BuildOverride()
     {
         var definition = this.MetadataReader.GetMethodDefinition(methodDef);
         var name = this.MetadataReader.GetString(definition.Name);
-        var provider = new TypeProvider(this.Assembly.Compilation);
+        var provider = this.Assembly.Compilation.TypeProvider;
         var signature = definition.DecodeSignature(provider, this);
         var containingType = provider.GetTypeFromDefinition(this.MetadataReader, definition.GetDeclaringType(), 0);
         return GetFunctionWithSignature(containingType, name, signature);
@@ -204,7 +203,7 @@ private void BuildOverride()
     {
         var reference = this.MetadataReader.GetMemberReference(methodRef);
         var name = this.MetadataReader.GetString(reference.Name);
-        var provider = new TypeProvider(this.Assembly.Compilation);
+        var provider = this.Assembly.Compilation.TypeProvider;
         var signature = reference.DecodeMethodSignature(provider, this);
         var containingType = provider.GetTypeFromReference(this.MetadataReader, (TypeReferenceHandle)reference.Parent, 0);
         return GetFunctionWithSignature(containingType, name, signature);

src/Draco.Compiler/Internal/Symbols/Metadata/MetadataSymbol.cs

@@ -58,7 +58,7 @@ public static IEnumerable<Symbol> ToSymbol(
         foreach (var attributeHandle in typeDefinition.GetCustomAttributes())
         {
             var attribute = reader.GetCustomAttribute(attributeHandle);
-            var typeProvider = new TypeProvider(compilation!);
+            var typeProvider = compilation.TypeProvider;
             switch (attribute.Constructor.Kind)
             {
             case HandleKind.MethodDefinition:

src/Draco.Compiler/Internal/Symbols/Metadata/MetadataTypeSymbol.cs

@@ -95,7 +95,7 @@ private ImmutableArray<TypeParameterSymbol> BuildGenericParameters()
     private ImmutableArray<TypeSymbol> BuildBaseTypes()
     {
         var builder = ImmutableArray.CreateBuilder<TypeSymbol>();
-        var typeProvider = new TypeProvider(this.Assembly.Compilation);
+        var typeProvider = this.Assembly.Compilation.TypeProvider;
         if (!this.typeDefinition.BaseType.IsNil)
         {
             builder.Add(GetTypeFromMetadata(this.typeDefinition.BaseType));

src/Draco.Compiler/Internal/Symbols/Metadata/TypeProvider.cs

@@ -19,6 +19,7 @@ internal sealed class TypeProvider : ISignatureTypeProvider<TypeSymbol, Symbol>,
     private IntrinsicSymbols IntrinsicSymbols => this.compilation.IntrinsicSymbols;
 
     private readonly Compilation compilation;
+    private readonly Dictionary<EntityHandle, TypeSymbol> cache = new();
 
     public TypeProvider(Compilation compilation)
     {
@@ -36,6 +37,7 @@ public TypeSymbol GetGenericInstantiation(TypeSymbol genericType, ImmutableArray
         if (ReferenceEquals(genericType, UnknownType)) return UnknownType;
         return genericType.GenericInstantiate(genericType.ContainingSymbol, typeArguments);
     }
+
     public TypeSymbol GetGenericMethodParameter(Symbol genericContext, int index)
     {
         var methodAncestor = genericContext.AncestorChain
@@ -46,6 +48,7 @@ public TypeSymbol GetGenericMethodParameter(Symbol genericContext, int index)
             ? methodAncestor.GenericParameters[index]
             : methodAncestor.GenericDefinition!.GenericParameters[index];
     }
+
     public TypeSymbol GetGenericTypeParameter(Symbol genericContext, int index)
     {
         var typeAncestor = genericContext.AncestorChain
@@ -56,6 +59,7 @@ public TypeSymbol GetGenericTypeParameter(Symbol genericContext, int index)
             ? typeAncestor.GenericParameters[index]
             : typeAncestor.GenericDefinition!.GenericParameters[index];
     }
+
     public TypeSymbol GetModifiedType(TypeSymbol modifier, TypeSymbol unmodifiedType, bool isRequired) => UnknownType;
     public TypeSymbol GetPinnedType(TypeSymbol elementType) => UnknownType;
     public TypeSymbol GetPointerType(TypeSymbol elementType) => UnknownType;
@@ -84,8 +88,10 @@ public TypeSymbol GetGenericTypeParameter(Symbol genericContext, int index)
 
         _ => UnknownType,
     };
+
     public TypeSymbol GetTypeFromDefinition(MetadataReader reader, TypeDefinitionHandle handle, byte rawTypeKind)
     {
+        if (this.cache.ContainsKey(handle)) return this.cache[handle];
         var definition = reader.GetTypeDefinition(handle);
         if (definition.IsNested)
         {
@@ -101,6 +107,7 @@ public TypeSymbol GetTypeFromDefinition(MetadataReader reader, TypeDefinitionHan
                 .OfType<TypeSymbol>()
                 .Where(t => t.Name == nestedName && t.GenericParameters.Length == nestedGenericArgc)
                 .Single();
+            this.cache[handle] = nestedSymbol;
             return nestedSymbol;
         }
 
@@ -114,10 +121,14 @@ public TypeSymbol GetTypeFromDefinition(MetadataReader reader, TypeDefinitionHan
         var fullName = string.IsNullOrWhiteSpace(@namespace) ? name : $"{@namespace}.{name}";
         var path = fullName.Split('.').ToImmutableArray();
 
-        return this.WellKnownTypes.GetTypeFromAssembly(assemblyName, path);
+        var result = this.WellKnownTypes.GetTypeFromAssembly(assemblyName, path);
+        this.cache[handle] = result;
+        return result;
     }
+
     public TypeSymbol GetTypeFromReference(MetadataReader reader, TypeReferenceHandle handle, byte rawTypeKind)
     {
+        if (this.cache.ContainsKey(handle)) return this.cache[handle];
         var parts = new List<string>();
         var reference = reader.GetTypeReference(handle);
         parts.Add(reader.GetString(reference.Name));
@@ -134,12 +145,17 @@ public TypeSymbol GetTypeFromReference(MetadataReader reader, TypeReferenceHandl
         // TODO: If we don't have the assembly report error
         var assemblyName = reader.GetAssemblyReference((AssemblyReferenceHandle)resolutionScope).GetAssemblyName();
         var assembly = this.compilation.MetadataAssemblies.Values.Single(x => x.AssemblyName.FullName == assemblyName.FullName);
-        return assembly.RootNamespace.Lookup(parts.ToImmutableArray()).OfType<TypeSymbol>().Single();
+        var result = assembly.RootNamespace.Lookup(parts.ToImmutableArray()).OfType<TypeSymbol>().Single();
+        this.cache[handle] = result;
+        return result;
     }
+
+    // TODO: Should we cache this as well? doesn't seem to have any effect
     public TypeSymbol GetTypeFromSpecification(MetadataReader reader, Symbol genericContext, TypeSpecificationHandle handle, byte rawTypeKind)
     {
         var specification = reader.GetTypeSpecification(handle);
-        return specification.DecodeSignature(this, genericContext);
+        var result = specification.DecodeSignature(this, genericContext);
+        return result;
     }
 
     public TypeSymbol GetSystemType() => this.WellKnownTypes.SystemType;