Substitution for type variables in mirrors on instantiated generics.

runtime/lib/mirrors_impl.dart

Index: runtime/lib/mirrors_impl.dart
diff --git a/runtime/lib/mirrors_impl.dart b/runtime/lib/mirrors_impl.dart
index 9759d53bd15c4692176930bc5619fc94f937b65c..0165149beec030d446c04500a7e341cd0ee472c2 100644
--- a/runtime/lib/mirrors_impl.dart
+++ b/runtime/lib/mirrors_impl.dart
@@ -433,6 +433,8 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
   final bool _isMixinTypedef;
   final bool _isGenericDeclaration;
 
+  TypeMirror _instantiateInContextOf(declaration) => this;
+
   bool get hasReflectedType => !_isGenericDeclaration;
   Type get reflectedType {
     if (!hasReflectedType) {
@@ -483,7 +485,9 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
   ClassMirror _trueSuperclassField;
   ClassMirror get _trueSuperclass {
     if (_trueSuperclassField == null) {
-      Type supertype = _supertype(_reflectee);
+      Type supertype = isOriginalDeclaration
+          ? _supertype(_reflectedType)

[rmacnak, 2013/10/09 01:15:00]

Unfortunately, this is not the same as reflecting on the instantiated supertype
and getting its original declaration.

[ahe, 2013/10/10 16:53:38]

Why?

[rmacnak, 2013/10/11 01:04:22]

Consider
class S<T>
class C<R> extends S<R>

The superclass of the declaration of C is S<R>, not the declaration of S.

[ahe, 2013/10/11 12:43:34]

I'm not sure I understand this. What is the difference between _supertype and
_supertypeInstantiated?

+          : _supertypeInstantiated(_reflectedType);
       if (supertype == null) {
         // Object has no superclass.
         return null;
@@ -596,11 +600,19 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
     return _constructors;
   }
 
+  bool get _isAnonymousMixinApplication {
+    if (_isMixinTypedef) return false;  // Named mixin application.
+    if (mixin == this) return false;  // Not a mixin application.
+    return true;
+  }
+
   List<TypeVariableMirror> _typeVariables = null;
   List<TypeVariableMirror> get typeVariables {
     if (_typeVariables == null) {
-      List params = _ClassMirror_type_variables(_reflectee);
       _typeVariables = new List<TypeVariableMirror>();
+      if (_isAnonymousMixinApplication) return _typeVariables;
+
+      List params = _ClassMirror_type_variables(_reflectee);
       var mirror;
       for (var i = 0; i < params.length; i += 2) {
         mirror = new _LocalTypeVariableMirrorImpl(
@@ -614,7 +626,7 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
   List<TypeMirror> _typeArguments = null;
   List<TypeMirror> get typeArguments {
     if(_typeArguments == null) {
-      if(_isGenericDeclaration) {
+      if(_isGenericDeclaration || _isAnonymousMixinApplication) {
         _typeArguments = new List<TypeMirror>();
       } else {
         _typeArguments =
@@ -691,9 +703,12 @@ class _LocalClassMirrorImpl extends _LocalObjectMirrorImpl
   static _library(reflectee)
       native "ClassMirror_library";
 
-  static _supertype(reflectee)
+  static _supertype(reflectedType)
       native "ClassMirror_supertype";
 
+  static _supertypeInstantiated(reflectedType)
+      native "ClassMirror_supertype_instantiated";
+
   static _interfaces(reflectee)
       native "ClassMirror_interfaces";
 
@@ -853,6 +868,22 @@ class _LocalTypeVariableMirrorImpl extends _LocalDeclarationMirrorImpl
 
   static Type _TypeVariableMirror_upper_bound(reflectee)
       native "TypeVariableMirror_upper_bound";
+
+  static Type _TypeVariableMirror_instantiate_from(reflectee, instantator)

[regis, 2013/10/09 15:46:51]

instantiator

[rmacnak, 2013/10/11 01:04:22]

Done.

+      native "TypeVariableMirror_instantiate_from";
+
+  TypeMirror _instantiateInContextOf(declaration) {
+    var instantator = declaration;
+    while (instantator is MethodMirror) instantator = instantator.owner;

[regis, 2013/10/09 15:46:51]

ditto

+    if (instantator is LibraryMirror) return this;
+    if (instantator is! ClassMirror) throw "UNREACHABLE";
+    if (instantator.isOriginalDeclaration) return this;
+
+    return _Mirrors._reflectType(
+        _TypeVariableMirror_instantiate_from(
+            _reflectee,
+            instantator._reflectedType));
+  }
 }
 
 
@@ -896,6 +927,9 @@ class _LocalTypedefMirrorImpl extends _LocalDeclarationMirrorImpl
 
   static _TypedefMirror_referent(_reflectee)
       native "TypedefMirror_referent";
+
+  // TODO(12282): This is wrong.
+  TypeMirror _instantiateInContextOf(declaration) => this;
 }
 
 class _LocalLibraryMirrorImpl extends _LocalObjectMirrorImpl
@@ -1064,6 +1098,7 @@ class _LocalMethodMirrorImpl extends _LocalDeclarationMirrorImpl
         _returnType =
             _Mirrors._reflectType(_MethodMirror_return_type(_reflectee));
       }
+      _returnType = _returnType._instantiateInContextOf(owner);
     }
     return _returnType;
   }
@@ -1158,6 +1193,7 @@ class _LocalVariableMirrorImpl extends _LocalDeclarationMirrorImpl
   TypeMirror get type {
     if (_type == null) {
        _type = _Mirrors._reflectType(_VariableMirror_type(_reflectee));
+       _type = _type._instantiateInContextOf(owner);
     }
     return _type;
   }
@@ -1215,6 +1251,7 @@ class _LocalParameterMirrorImpl extends _LocalVariableMirrorImpl
     if (_type == null) {
       _type =
           _Mirrors._reflectType(_ParameterMirror_type(_reflectee, _position));
+      _type = _type._instantiateInContextOf(owner);
     }
     return _type;
   }
@@ -1254,6 +1291,8 @@ class _SpecialTypeMirrorImpl extends _LocalMirrorImpl
   int get hashCode => simpleName.hashCode;
 
   String toString() => "TypeMirror on '${_n(simpleName)}'";
+
+  TypeMirror _instantiateInContextOf(declaration) => this;
 }
 
 class _Mirrors {