Substitution for type variables in mirrors on instantiated generics.

runtime/lib/mirrors.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "lib/invocation_mirror.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
@@ skipping 206 matching lines @@
   const TypeArguments& args = TypeArguments::Handle(cls.type_parameters());
   if (args.IsNull()) {
     return Object::empty_array().raw();
   }
   const Array& result = Array::Handle(Array::New(args.Length() * 2));
   TypeParameter& type = TypeParameter::Handle();
   String& name = String::Handle();
   for (intptr_t i = 0; i < args.Length(); i++) {
     type ^= args.TypeAt(i);
     ASSERT(type.IsTypeParameter());
+    ASSERT(!type.IsMalformed());
+    ASSERT(type.IsFinalized());
     name ^= type.name();
     result.SetAt(2 * i, name);
     result.SetAt(2 * i + 1, type);
   }
   return result.raw();
 }
 
 
 static RawInstance* CreateTypedefMirror(const Class& cls,
                                         const Instance& owner_mirror) {
@@ skipping 69 matching lines @@
     lookup_cls = lookup_cls.SuperClass();
   } while (!lookup_cls.IsNull());
   return Function::null();
 }
 
 static RawInstance* CreateClassMirror(const Class& cls,
                                       const AbstractType& type,
                                       const Bool& is_declaration,
                                       const Instance& owner_mirror) {
   ASSERT(!cls.IsDynamicClass() && !cls.IsVoidClass());
+  ASSERT(!type.IsNull());
+  ASSERT(type.IsFinalized());
 
   if (cls.IsSignatureClass()) {
     if (cls.IsCanonicalSignatureClass()) {
       // We represent function types as canonical signature classes.
       return CreateFunctionTypeMirror(cls, type);
     } else {
       // We represent typedefs as non-canonical signature classes.
       return CreateTypedefMirror(cls, owner_mirror);
     }
   }
 
-  ASSERT(!type.IsNull());
-
   const Bool& is_generic = Bool::Get(cls.NumTypeParameters() != 0);
   const Bool& is_mixin_typedef = Bool::Get(cls.is_mixin_typedef());
 
   const Array& args = Array::Handle(Array::New(6));
   args.SetAt(0, MirrorReference::Handle(MirrorReference::New(cls)));
   args.SetAt(1, type);
   // We do not set the names of anonymous mixin applications because the mirrors
   // use a different naming convention than the VM (lib.S with lib.M and S&M
   // respectively).
   if (!cls.IsMixinApplication() || cls.is_mixin_typedef()) {
@@ skipping 12 matching lines @@
   String& str = String::Handle();
   str = lib.name();
   args.SetAt(1, str);
   str = lib.url();
   args.SetAt(2, str);
   return CreateMirror(Symbols::_LocalLibraryMirrorImpl(), args);
 }
 
 
 static RawInstance* CreateTypeMirror(const AbstractType& type) {
+  ASSERT(type.IsFinalized());
   ASSERT(!type.IsMalformed());
   if (type.HasResolvedTypeClass()) {
     const Class& cls = Class::Handle(type.type_class());
     // Handle void and dynamic types.
     if (cls.IsVoidClass()) {
       Array& args = Array::Handle(Array::New(1));
       args.SetAt(0, Symbols::Void());
       // TODO(mlippautz): Create once in the VM isolate and retrieve from there.
       return CreateMirror(Symbols::_SpecialTypeMirrorImpl(), args);
     } else if (cls.IsDynamicClass()) {
       Array& args = Array::Handle(Array::New(1));
       args.SetAt(0, Symbols::Dynamic());
       // TODO(mlippautz): Create once in the VM isolate and retrieve from there.
       return CreateMirror(Symbols::_SpecialTypeMirrorImpl(), args);
     }
     return CreateClassMirror(cls, type, Bool::False(), Object::null_instance());
   } else if (type.IsTypeParameter()) {
     return CreateTypeVariableMirror(TypeParameter::Cast(type),
                                     Object::null_instance());
+  } else if (type.IsBoundedType()) {
+    AbstractType& actual_type =
+        AbstractType::Handle(BoundedType::Cast(type).type());
+    return CreateTypeMirror(actual_type);
   }
   UNREACHABLE();
   return Instance::null();
 }
 
 
 static RawInstance* CreateIsolateMirror() {
   Isolate* isolate = Isolate::Current();
   const String& debug_name = String::Handle(String::New(isolate->name()));
   const Library& root_library =
@@ skipping 365 matching lines @@
   return Object::sentinel().raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(Mirrors_makeLocalMirrorSystem, 0) {
   return CreateMirrorSystem();
 }
 
 
 DEFINE_NATIVE_ENTRY(Mirrors_makeLocalClassMirror, 1) {
-  GET_NON_NULL_NATIVE_ARGUMENT(Type, type, arguments->NativeArgAt(0));
+  GET_NON_NULL_NATIVE_ARGUMENT(AbstractType, type, arguments->NativeArgAt(0));
+  ASSERT(!type.IsMalformed());
+  ASSERT(type.IsFinalized());
+  ASSERT(type.HasResolvedTypeClass());
   const Class& cls = Class::Handle(type.type_class());
-  ASSERT(!cls.IsNull());
   if (cls.IsDynamicClass() || cls.IsVoidClass()) {
     Exceptions::ThrowArgumentError(type);
     UNREACHABLE();
   }
-  const Type& stripped_type = Type::Handle(cls.RareType());
+  const AbstractType& stripped_type = AbstractType::Handle(cls.RareType());
   return CreateClassMirror(cls,
                            stripped_type,
                            Bool::True(),  // is_declaration
                            Object::null_instance());
 }
 
 
 DEFINE_NATIVE_ENTRY(Mirrors_makeLocalTypeMirror, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(AbstractType, type, arguments->NativeArgAt(0));
   return CreateTypeMirror(type);
@@ skipping 81 matching lines @@
 DEFINE_NATIVE_ENTRY(ClassMirror_library, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Class& klass = Class::Handle(ref.GetClassReferent());
   const Library& library = Library::Handle(klass.library());
   ASSERT(!library.IsNull());
   return CreateLibraryMirror(library);
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_supertype, 1) {
-  GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
-  const Class& klass = Class::Handle(ref.GetClassReferent());
-  return klass.super_type();
+  GET_NON_NULL_NATIVE_ARGUMENT(AbstractType, type, arguments->NativeArgAt(0));
+  ASSERT(!type.IsMalformed());
+  ASSERT(type.IsFinalized());
+  const Class& cls = Class::Handle(type.type_class());
+  const AbstractType& super_type = AbstractType::Handle(cls.super_type());
+  if (super_type.IsType()) {
+    ASSERT(super_type.IsFinalized());

[regis, 2013/10/11 01:28:59]

You could write
ASSERT(!super_type.IsType() || super_type.IsFinalized());

But in what cases can you encounter a non-finalized super type?
The only case you need to keep in mind is that the super type of Object is null.
Therefore, this should work:
ASSERT(super_type.IsNull() || super_type.IsFinalized());

[rmacnak, 2013/10/11 01:48:02]

Yep, that holds. Also explains why I had trouble printing what the non-Type
thing was...

+  }
+  return super_type.raw();
+}
+
+DEFINE_NATIVE_ENTRY(ClassMirror_supertype_instantiated, 1) {
+  GET_NON_NULL_NATIVE_ARGUMENT(AbstractType, type, arguments->NativeArgAt(0));
+  ASSERT(!type.IsMalformed());
+  ASSERT(type.IsFinalized());
+  const Class& cls = Class::Handle(type.type_class());
+  AbstractType& super_type = AbstractType::Handle(cls.super_type());
+  AbstractType& result = AbstractType::Handle(super_type.raw());
+
+  ASSERT(super_type.IsType());
+  if (!super_type.IsInstantiated()) {
+    AbstractTypeArguments& type_args =
+        AbstractTypeArguments::Handle(type.arguments());
+    Error& bound_error = Error::Handle();
+    result ^= super_type.InstantiateFrom(type_args, &bound_error);
+    result ^= result.Canonicalize();

[regis, 2013/10/11 01:28:59]

I would canonicalize after checking for a bound error.

[rmacnak, 2013/10/11 01:48:02]

Done.

+    if (!bound_error.IsNull()) {
+      ThrowInvokeError(bound_error);
+      UNREACHABLE();
+    }
+    ASSERT(result.IsType());
+  }
+
+  ASSERT(result.IsFinalized());
+  return result.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(ClassMirror_interfaces, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Class& klass = Class::Handle(ref.GetClassReferent());
 
   const Error& error = Error::Handle(klass.EnsureIsFinalized(isolate));
   if (!error.IsNull()) {
     ThrowInvokeError(error);
@@ skipping 180 matching lines @@
     type_mirror = CreateTypeMirror(arg_type);
     result.SetAt(i, type_mirror);
   }
   return result.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(TypeVariableMirror_owner, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypeParameter, param, arguments->NativeArgAt(0));
   const Class& owner = Class::Handle(param.parameterized_class());
-  const Type& type = Type::Handle(owner.RareType());
+  const AbstractType& type = AbstractType::Handle(owner.RareType());
   return CreateClassMirror(owner,
                            type,
                            Bool::True(),  // is_declaration
                            Instance::null_instance());
 }
 
 
 DEFINE_NATIVE_ENTRY(TypeVariableMirror_upper_bound, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypeParameter, param, arguments->NativeArgAt(0));
   return param.bound();
 }
 
 
+DEFINE_NATIVE_ENTRY(TypeVariableMirror_instantiate_from, 2) {
+  GET_NON_NULL_NATIVE_ARGUMENT(TypeParameter, param, arguments->NativeArgAt(0));
+  GET_NON_NULL_NATIVE_ARGUMENT(Type, instantiator, arguments->NativeArgAt(1));
+
+  ASSERT(param.parameterized_class() == instantiator.type_class());
+
+  AbstractTypeArguments& type_args =
+      AbstractTypeArguments::Handle(instantiator.arguments());
+  Error& bound_error = Error::Handle();
+  AbstractType& result =
+      AbstractType::Handle(param.InstantiateFrom(type_args, &bound_error));
+  ASSERT(bound_error.IsNull());
+  ASSERT(result.IsFinalized());
+  return result.raw();
+}
+
+
 DEFINE_NATIVE_ENTRY(InstanceMirror_invoke, 5) {
   // Argument 0 is the mirror, which is unused by the native. It exists
   // because this native is an instance method in order to be polymorphic
   // with its cousins.
   GET_NATIVE_ARGUMENT(Instance, reflectee, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(
       String, function_name, arguments->NativeArgAt(2));
   GET_NON_NULL_NATIVE_ARGUMENT(Array, args, arguments->NativeArgAt(3));
   GET_NON_NULL_NATIVE_ARGUMENT(Array, arg_names, arguments->NativeArgAt(4));
 
@@ skipping 540 matching lines @@
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   if (func.IsNonImplicitClosureFunction()) {
     return CreateMethodMirror(Function::Handle(
         func.parent_function()), Object::null_instance());
   }
   const Class& owner = Class::Handle(func.Owner());
   if (owner.IsTopLevel()) {
     return CreateLibraryMirror(Library::Handle(owner.library()));
   }
 
-  Type& type = Type::Handle(owner.RareType());
+  AbstractType& type = AbstractType::Handle(owner.RareType());
   return CreateClassMirror(owner, type, Bool::True(), Object::null_instance());
 }
 
 
 DEFINE_NATIVE_ENTRY(MethodMirror_parameters, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, owner, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(1));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   return CreateParameterMirrorList(func, owner);
 }
@@ skipping 54 matching lines @@
 }
 
 
 DEFINE_NATIVE_ENTRY(VariableMirror_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Field& field = Field::Handle(ref.GetFieldReferent());
   return field.type();
 }
 
 }  // namespace dart