Implement tear-off closure operator #

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index d47ed574a05e8638a17e13a4dfe1560f1f5959e4..2476e5ccaa1b547e318203a97010f22014317923 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -7380,6 +7380,39 @@ void Field::PrintJSONImpl(JSONStream* stream, bool ref) const {
 }
 
 
+RawInstance* Field::GetterClosure() const {
+  ASSERT(is_static());
+  const Class& field_owner = Class::Handle(owner());
+  const char* field_name = String::Handle(name()).ToCString();
+  String& expr_src = String::Handle(
+      String::NewFormatted("() { return %s; }", field_name));
+  Object& result =
+      Object::Handle(field_owner.Evaluate(expr_src,

[Florian Schneider, 2015/07/17 09:42:02]

With precompilation we can't invoke the compiler at runtime.

[hausner, 2015/07/17 17:53:51]

Yes. This evaluation happens at (pre-)compile time. I was hoping that there is a
way to also compile the resulting closure object at pre-compile time. 

+                                          Object::empty_array(),
+                                          Object::empty_array()));
+  ASSERT(result.IsInstance());
+  result = Object::Clone(result, Heap::kOld);

[Ivan Posva, 2015/07/17 08:35:42]

Why is this necessary?

[hausner, 2015/07/17 17:53:51]

Because the result will be stuck into a LiteralNode in the parser, and the
constructor for LiteralNode wants the literal to be allocated in old space.
Close is a private method of object, so I can't call it in the parser, which
would otherwise be my preference.

+  return Instance::RawCast(result.raw());
+}
+
+
+RawInstance* Field::SetterClosure() const {
+  ASSERT(is_static());
+  const Class& field_owner = Class::Handle(owner());
+  const char* field_name = String::Handle(name()).ToCString();
+  // TODO(hausner): Ensure that parameter name does not hide field name.
+  String& expr_src = String::Handle(
+      String::NewFormatted("(xxx) { return %s = xxx; }", field_name));
+  Object& result =
+      Object::Handle(field_owner.Evaluate(expr_src,

[Florian Schneider, 2015/07/17 09:42:02]

Same issue here with precompiled code.

+                                          Object::empty_array(),
+                                          Object::empty_array()));
+  ASSERT(result.IsInstance());
+  result = Object::Clone(result, Heap::kOld);
+  return Instance::RawCast(result.raw());
+}
+
+
 RawArray* Field::dependent_code() const {
   return raw_ptr()->dependent_code_;
 }