Implement tear-off closure operator #

runtime/vm/object.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 "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 7362 matching lines @@
     jsobj.AddProperty("_guardLength", guarded_list_length());
   }
   const Class& origin_cls = Class::Handle(origin());
   const Script& script = Script::Handle(origin_cls.script());
   if (!script.IsNull()) {
     jsobj.AddLocation(script, token_pos());
   }
 }
 
 
+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_;
 }
 
 
 void Field::set_dependent_code(const Array& array) const {
   StorePointer(&raw_ptr()->dependent_code_, array.raw());
 }
 
 
@@ skipping 13798 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart