Fix for issue 6623 - Canonicalize implicit static closure objects.

runtime/vm/flow_graph_builder.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/flow_graph_builder.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_descriptors.h"
 #include "vm/dart_entry.h"
 #include "vm/flags.h"
@@ skipping 1465 matching lines @@
                                                   arguments,
                                                   node->type(),
                                                   element_type);
   ReturnDefinition(create);
 }
 
 
 void EffectGraphVisitor::VisitClosureNode(ClosureNode* node) {
   const Function& function = node->function();
 
+  if (function.IsImplicitStaticClosureFunction()) {
+    Instance& closure = Instance::ZoneHandle();
+    closure ^= function.implicit_static_closure();
+    if (closure.IsNull()) {
+      ObjectStore* object_store = Isolate::Current()->object_store();
+      const Context& context = Context::Handle(object_store->empty_context());
+      closure ^= Closure::New(function, context, Heap::kOld);
+      function.set_implicit_static_closure(closure);
+    }
+    ReturnDefinition(new ConstantInstr(closure));
+    return;
+  }
   Value* receiver = NULL;
   if (function.IsNonImplicitClosureFunction()) {
     // The context scope may have already been set by the non-optimizing
     // compiler.  If it was not, set it here.
     if (function.context_scope() == ContextScope::null()) {
       // TODO(regis): Why are we not doing this in the parser?
       const ContextScope& context_scope = ContextScope::ZoneHandle(
           node->scope()->PreserveOuterScope(owner()->context_level()));
       ASSERT(!function.HasCode());
       ASSERT(function.context_scope() == ContextScope::null());
       function.set_context_scope(context_scope);
     }
     receiver = BuildNullValue();
-  } else if (function.IsImplicitInstanceClosureFunction()) {
+  } else {
+    ASSERT(function.IsImplicitInstanceClosureFunction());
     ValueGraphVisitor for_receiver(owner(), temp_index(), loop_depth());
     node->receiver()->Visit(&for_receiver);
     Append(for_receiver);
     receiver = for_receiver.value();
-  } else {
-    receiver = BuildNullValue();
   }
   PushArgumentInstr* push_receiver = PushArgument(receiver);
   ZoneGrowableArray<PushArgumentInstr*>* arguments =
       new ZoneGrowableArray<PushArgumentInstr*>(2);
   arguments->Add(push_receiver);
   ASSERT(function.context_scope() != ContextScope::null());
 
   // The function type of a closure may have type arguments. In that case, pass
   // the type arguments of the instantiator. Otherwise, pass null object.
   const Class& cls = Class::Handle(function.signature_class());
@@ skipping 1420 matching lines @@
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, function_name, reason) + 1;
   char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
       LanguageError::New(String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }
 
 
 }  // namespace dart