1. Dynamic compute the main closure that needs to be run by the main isolate

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/become.h"
@@ skipping 12035 matching lines @@
       }
     }
     if (!func.IsNull()) {
       return func.raw();
     }
   }
   return Function::null();
 }
 
 
+RawObject* Library::GetFunctionClosure(const String& name) const {
+  Thread* thread = Thread::Current();
+  Zone* zone = thread->zone();
+  Function& func = Function::Handle(zone, LookupFunctionAllowPrivate(name));
+  if (func.IsNull()) {
+    // Check whether the function is reexported into the library.
+    const Object& obj = Object::Handle(zone, LookupReExport(name));
+    if (obj.IsFunction()) {
+      func ^= obj.raw();
+    } else {
+      // Check if there is a getter of 'name', in which case invoke it
+      // and return the result.
+      const String& getter_name = String::Handle(zone, Field::GetterName(name));
+      func = LookupFunctionAllowPrivate(getter_name);
+      if (func.IsNull()) {
+        return Closure::null();
+      }
+      // Invoke the getter and return the result.
+      return DartEntry::InvokeFunction(func, Object::empty_array());
+    }
+  }
+  func = func.ImplicitClosureFunction();
+  return func.ImplicitStaticClosure();
+}
+
+
 #if defined(DART_NO_SNAPSHOT) && !defined(PRODUCT)
 void Library::CheckFunctionFingerprints() {
   GrowableArray<Library*> all_libs;
   Function& func = Function::Handle();
   bool has_errors = false;
 
 #define CHECK_FINGERPRINTS(class_name, function_name, dest, fp)                \
   func = GetFunction(all_libs, #class_name, #function_name);                   \
   if (func.IsNull()) {                                                         \
     has_errors = true;                                                         \
@@ skipping 11310 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart