Add support for converted closures with explicit contexts to VM

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index d5062633402b9c66a7b4e20c46a5eb4e109c01be..dfa966abc562e2605b3295ed3d3a9b39abb55112 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -499,6 +499,10 @@ class Object {
     ASSERT(void_type_ != NULL);
     return *void_type_;
   }
+  static const Type& vector_type() {
+    ASSERT(vector_type_ != NULL);
+    return *vector_type_;
+  }
 
   static void set_vm_isolate_snapshot_object_table(const Array& table);
 
@@ -763,6 +767,7 @@ class Object {
   static RawClass* class_class_;             // Class of the Class vm object.
   static RawClass* dynamic_class_;           // Class of the 'dynamic' type.
   static RawClass* void_class_;              // Class of the 'void' type.
+  static RawClass* vector_class_;            // Class of the 'vector' type.
   static RawClass* unresolved_class_class_;  // Class of UnresolvedClass.
   static RawClass* type_arguments_class_;  // Class of TypeArguments vm object.
   static RawClass* patch_class_class_;     // Class of the PatchClass vm object.
@@ -829,6 +834,7 @@ class Object {
   static Array* vm_isolate_snapshot_object_table_;
   static Type* dynamic_type_;
   static Type* void_type_;
+  static Type* vector_type_;
 
   friend void ClassTable::Register(const Class& cls);
   friend void RawObject::Validate(Isolate* isolate) const;
@@ -1573,9 +1579,9 @@ class UnresolvedClass : public Object {
 
 // Classification of type genericity according to type parameter owners.
 enum Genericity {
-  kAny,              // Consider type params of current class and functions.
-  kCurrentClass,     // Consider type params of current class only.
-  kFunctions,        // Consider type params of current and parent functions.
+  kAny,           // Consider type params of current class and functions.
+  kCurrentClass,  // Consider type params of current class only.
+  kFunctions,     // Consider type params of current and parent functions.
 };
 
 
@@ -2395,11 +2401,22 @@ class Function : public Object {
     return implicit_closure_function() != null();
   }
 
+  // Returns true iff a converted closure function has been created
+  // for this function.
+  bool HasConvertedClosureFunction() const {
+    return converted_closure_function() != null();
+  }
+
   // Return the closure function implicitly created for this function.
   // If none exists yet, create one and remember it.
   RawFunction* ImplicitClosureFunction() const;
   void DropUncompiledImplicitClosureFunction() const;
 
+  // Return the converted closure function created for this function.

[kustermann, 2017/06/20 12:13:14]

s/Return/Returns/

also above in the old code.

[Dmitry Stefantsov, 2017/06/22 14:12:52]

Thanks!  Fixed.

+  // If none exists yet, create one and remember it.
+  RawFunction* ConvertedClosureFunction() const;
+  void DropUncompiledConvertedClosureFunction() const;

[kustermann, 2017/06/20 12:13:14]

A reader of this could would be very curious what the difference between a
"implicit closure function" and a "converted closure function" is.

Consider adding a length comment somewhere explaining the difference (or add a
pointer to look where to find the documentation)

[Dmitry Stefantsov, 2017/06/22 14:12:52]

I think the comment on `Function::ConvertedClosureFunction` in
runtime/vm/object.cc partially explains the difference.  I'll put a reference to
it here.  I also added a comment above, for `ImplicitClosureFunction` stating
that it is used for tear-offs.

+
   // Return the closure implicitly created for this function.
   // If none exists yet, create one and remember it.
   RawInstance* ImplicitStaticClosure() const;
@@ -2760,6 +2777,11 @@ class Function : public Object {
   // Returns true if this function represents an implicit closure function.
   bool IsImplicitClosureFunction() const;
 
+  // Returns true if this function represents a converted closure function.
+  bool IsConvertedClosureFunction() const {
+    return kind() == RawFunction::kConvertedClosureFunction;
+  }
+
   // Returns true if this function represents a non implicit closure function.
   bool IsNonImplicitClosureFunction() const {
     return IsClosureFunction() && !IsImplicitClosureFunction();
@@ -2852,6 +2874,11 @@ class Function : public Object {
                                          const Function& parent,
                                          TokenPosition token_pos);
 
+  // Allocates a new Function object representing a converted closure function.
+  static RawFunction* NewConvertedClosureFunction(const String& name,
+                                                  const Function& parent,
+                                                  TokenPosition token_pos);
+
   // Allocates a new Function object representing a signature function.
   // The owner is the scope class of the function type.
   static RawFunction* NewSignatureFunction(const Object& owner,
@@ -3013,6 +3040,8 @@ class Function : public Object {
   void set_owner(const Object& value) const;
   RawFunction* implicit_closure_function() const;
   void set_implicit_closure_function(const Function& value) const;
+  RawFunction* converted_closure_function() const;
+  void set_converted_closure_function(const Function& value) const;
   RawInstance* implicit_static_closure() const;
   void set_implicit_static_closure(const Instance& closure) const;
   RawScript* eval_script() const;
@@ -5106,7 +5135,7 @@ class Code : public Object {
   friend class SnapshotWriter;
   friend class FunctionSerializationCluster;
   friend class CodeSerializationCluster;
-  friend class CodePatcher;  // for set_instructions
+  friend class CodePatcher;     // for set_instructions
   friend class ProgramVisitor;  // for set_instructions
   // So that the RawFunction pointer visitor can determine whether code the
   // function points to is optimized.