Add Genericity enum in VM to distinguish how a type is uninstantiated.

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index d208ee2e524689f45d174042ce5af94e68c7db5d..a413cd8de7990042ecf128d8545361c41563b108 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -1548,6 +1548,16 @@ class UnresolvedClass : public Object {
 };
 
 
+// Classification of type genericity according to type parameter owners.
+enum Genericity {
+  kAny,              // Consider type params of class and functions.
+  kClass,            // Consider type params of class only.
+  kFunctions,        // Consider type params of current and parent functions.
+  kCurrentFunction,  // Consider type params of current function only.
+  kParentFunctions   // Consider type params of parent functions only.
+};
+
+
 // A TypeArguments is an array of AbstractType.
 class TypeArguments : public Object {
  public:
@@ -1625,11 +1635,13 @@ class TypeArguments : public Object {
                              TrailPtr trail = NULL) const;
 
   // Check if the vector is instantiated (it must not be null).
-  bool IsInstantiated(TrailPtr trail = NULL) const {
-    return IsSubvectorInstantiated(0, Length(), trail);
+  bool IsInstantiated(Genericity genericity = kAny,
+                      TrailPtr trail = NULL) const {
+    return IsSubvectorInstantiated(0, Length(), genericity, trail);
   }
   bool IsSubvectorInstantiated(intptr_t from_index,
                                intptr_t len,
+                               Genericity genericity = kAny,
                                TrailPtr trail = NULL) const;
   bool IsUninstantiatedIdentity() const;
   bool CanShareInstantiatorTypeArguments(const Class& instantiator_class) const;
@@ -2275,6 +2287,9 @@ class Function : public Object {
   // Return true if this function declares type parameters.
   bool IsGeneric() const { return NumTypeParameters(Thread::Current()) > 0; }
 
+  // Return true if any parent function of this function is generic.
+  bool HasGenericParent() const;
+
   // Not thread-safe; must be called in the main thread.
   // Sets function's code and code's function.
   void InstallOptimizedCode(const Code& code, bool is_osr) const;
@@ -5678,7 +5693,8 @@ class AbstractType : public Instance {
   virtual RawTypeArguments* arguments() const;
   virtual void set_arguments(const TypeArguments& value) const;
   virtual TokenPosition token_pos() const;
-  virtual bool IsInstantiated(TrailPtr trail = NULL) const;
+  virtual bool IsInstantiated(Genericity genericity = kAny,
+                              TrailPtr trail = NULL) const;
   virtual bool CanonicalizeEquals(const Instance& other) const {
     return Equals(other);
   }
@@ -5893,7 +5909,8 @@ class Type : public AbstractType {
   virtual RawTypeArguments* arguments() const { return raw_ptr()->arguments_; }
   virtual void set_arguments(const TypeArguments& value) const;
   virtual TokenPosition token_pos() const { return raw_ptr()->token_pos_; }
-  virtual bool IsInstantiated(TrailPtr trail = NULL) const;
+  virtual bool IsInstantiated(Genericity genericity = kAny,
+                              TrailPtr trail = NULL) const;
   virtual bool IsEquivalent(const Instance& other, TrailPtr trail = NULL) const;
   virtual bool IsRecursive() const;
   // If signature is not null, this type represents a function type.
@@ -6031,7 +6048,8 @@ class TypeRef : public AbstractType {
   virtual TokenPosition token_pos() const {
     return AbstractType::Handle(type()).token_pos();
   }
-  virtual bool IsInstantiated(TrailPtr trail = NULL) const;
+  virtual bool IsInstantiated(Genericity genericity = kAny,
+                              TrailPtr trail = NULL) const;
   virtual bool IsEquivalent(const Instance& other, TrailPtr trail = NULL) const;
   virtual bool IsRecursive() const { return true; }
   virtual RawTypeRef* InstantiateFrom(
@@ -6115,7 +6133,8 @@ class TypeParameter : public AbstractType {
                   TrailPtr bound_trail,
                   Heap::Space space) const;
   virtual TokenPosition token_pos() const { return raw_ptr()->token_pos_; }
-  virtual bool IsInstantiated(TrailPtr trail = NULL) const { return false; }
+  virtual bool IsInstantiated(Genericity genericity = kAny,
+                              TrailPtr trail = NULL) const;
   virtual bool IsEquivalent(const Instance& other, TrailPtr trail = NULL) const;
   virtual bool IsRecursive() const { return false; }
   virtual RawAbstractType* InstantiateFrom(
@@ -6209,12 +6228,13 @@ class BoundedType : public AbstractType {
   virtual TokenPosition token_pos() const {
     return AbstractType::Handle(type()).token_pos();
   }
-  virtual bool IsInstantiated(TrailPtr trail = NULL) const {
+  virtual bool IsInstantiated(Genericity genericity = kAny,
+                              TrailPtr trail = NULL) const {
     // It is not possible to encounter an instantiated bounded type with an
     // uninstantiated upper bound. Therefore, we do not need to check if the
     // bound is instantiated. Moreover, doing so could lead into cycles, as in
     // class C<T extends C<C>> { }.
-    return AbstractType::Handle(type()).IsInstantiated(trail);
+    return AbstractType::Handle(type()).IsInstantiated(genericity, trail);
   }
   virtual bool IsEquivalent(const Instance& other, TrailPtr trail = NULL) const;
   virtual bool IsRecursive() const;