Make saving and restoring of the context around closure calls explicit.

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/bit_vector.h"
 #include "vm/code_descriptors.h"
 #include "vm/dart_entry.h"
@@ skipping 1353 matching lines @@
   StaticCallComp* call =
       new StaticCallComp(node->token_index(),
                          owner()->try_index(),
                          node->function(),
                          node->arguments()->names(),
                          values);
   ReturnComputation(call);
 }
 
 
-void EffectGraphVisitor::VisitClosureCallNode(ClosureCallNode* node) {
-  // Context is saved around the call, it's treated as an extra operand
-  // consumed by the call (but not an argument).
-  BindInstr* context = new BindInstr(new CurrentContextComp());
-  AddInstruction(context);
-
+ClosureCallComp* EffectGraphVisitor::BuildClosureCall(
+    ClosureCallNode* node) {
   ValueGraphVisitor for_closure(owner(), temp_index());
   node->closure()->Visit(&for_closure);
   Append(for_closure);
 
   ZoneGrowableArray<Value*>* arguments =
       new ZoneGrowableArray<Value*>(node->arguments()->length());
   arguments->Add(for_closure.value());
   TranslateArgumentList(*node->arguments(), arguments);
-  // First operand is the saved context, consumed by the call.
-  ClosureCallComp* call =  new ClosureCallComp(node,
-                                               owner()->try_index(),
-                                               new UseVal(context),
-                                               arguments);
-  ReturnComputation(call);
+
+  // Save context around the call.
+  BuildStoreContext(*owner()->parsed_function().expression_temp_var());
+  return new ClosureCallComp(node, owner()->try_index(), arguments);
+}
+
+
+void EffectGraphVisitor::VisitClosureCallNode(ClosureCallNode* node) {
+  ClosureCallComp* call = BuildClosureCall(node);
+  AddInstruction(new DoInstr(call));
+
+  // Restore context from saved location.
+  BuildLoadContext(*owner()->parsed_function().expression_temp_var());
+}
+
+
+void ValueGraphVisitor::VisitClosureCallNode(ClosureCallNode* node) {
+  ClosureCallComp* call = BuildClosureCall(node);
+  BindInstr* result = new BindInstr(call);
+  AddInstruction(result);
+
+  // Restore context from temp.
+  BuildLoadContext(*owner()->parsed_function().expression_temp_var());
+
+  ReturnValue(new UseVal(result));
 }
 
 
 void EffectGraphVisitor::VisitCloneContextNode(CloneContextNode* node) {
   BindInstr* context = new BindInstr(new CurrentContextComp());
   AddInstruction(context);
   BindInstr* clone =
       new BindInstr(new CloneContextComp(node->token_index(),
                                          owner()->try_index(),
                                          new UseVal(context)));
@@ skipping 975 matching lines @@
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(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