Implement tear-off closure operator #

runtime/vm/resolver.cc

 // Copyright (c) 2011, 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/resolver.h"
 
 #include "vm/dart_entry.h"
 #include "vm/flags.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 96 matching lines @@
   if (FLAG_trace_resolving) {
     OS::Print("ResolveDynamic '%s' for class %s\n",
               function_name.ToCString(),
               String::Handle(cls.Name()).ToCString());
   }
 
   const bool is_getter = Field::IsGetterName(function_name);
   String& field_name = String::Handle();
   if (is_getter) {
     field_name ^= Field::NameFromGetter(function_name);
+
+    if (field_name.CharAt(0) == '#') {

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

Please add explanation here how we generate the closurization lookups. As far as
I understand it is done by creating an instance call "obj.get:#property()".
Additional explanation will help though.

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

Correct. I will add a comment. The # in the getter name signals that we want to
closurize a getter rather than calling it (which is what we do in the old
closurization semantics.)

+      String& property_name = String::Handle(String::SubString(field_name, 1));
+
+      ASSERT(!Field::IsGetterName(property_name));
+      String& method_name = String::Handle();
+      if (!Field::IsSetterName(property_name)) {

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

Please add comment why the property name needs to be adjusted for getters but
not for setters.

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

Will do.

+        method_name = Field::GetterName(property_name);
+      }
+
+      Function& function = Function::Handle();
+      while (!cls.IsNull()) {
+        function = cls.LookupDynamicFunction(property_name);
+        if (!function.IsNull()) {
+          return CreateMethodExtractor(function_name, function);
+        }
+        if (!method_name.IsNull()) {
+          function = cls.LookupDynamicFunction(method_name);
+          if (!function.IsNull()) {
+            return CreateMethodExtractor(function_name, function);
+          }
+        }
+        cls = cls.SuperClass();
+      }
+      return Function::null();
+    }
   }
 
   // Now look for an instance function whose name matches function_name
   // in the class.
   Function& function = Function::Handle();
   while (!cls.IsNull()) {
     function ^= cls.LookupDynamicFunction(function_name);
     if (!function.IsNull()) {
       return function.raw();
     }
@@ skipping 124 matching lines @@
       OS::Print("ResolveStaticAllowPrivate error '%s': %s.\n",
                 function_name.ToCString(),
                 error_message.ToCString());
     }
     return Function::null();
   }
   return function.raw();
 }
 
 }  // namespace dart