Use a reserved stack local variable to store the Code object so that it can be looked up easily whe…

vm/parser.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/parser.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/compiler_stats.h"
@@ skipping 128 matching lines @@
 
 void ParsedFunction::AllocateVariables() {
   LocalScope* scope = node_sequence()->scope();
   const int fixed_parameter_count = function().num_fixed_parameters();
   const int optional_parameter_count = function().num_optional_parameters();
   const int parameter_count = fixed_parameter_count + optional_parameter_count;
   // Compute start indices to parameters and locals, and the number of
   // parameters to copy.
   if (optional_parameter_count == 0) {
     // Parameter i will be at fp[1 + parameter_count - i] and local variable
-    // j will be at fp[-1 - j].
+    // j will be at fp[kFirstStackSlotIndex - j].
     first_parameter_index_ = 1 + parameter_count;
-    first_stack_local_index_ = -1;
+    first_stack_local_index_ = kFirstStackSlotIndex;
     copied_parameter_count_ = 0;
   } else {
     // Parameter i will be at fp[-1 - i] and local variable j will be at
     // fp[-1 - parameter_count - j].
-    first_parameter_index_ = -1;
-    first_stack_local_index_ = -1 - parameter_count;
+    first_parameter_index_ = kFirstStackSlotIndex;
+    first_stack_local_index_ = first_parameter_index_ - parameter_count;
     copied_parameter_count_ = parameter_count;
   }
 
   // Allocate parameters and local variables, either in the local frame or
   // in the context(s).
   LocalScope* context_owner = NULL;  // No context needed yet.
   int next_free_frame_index =
       scope->AllocateVariables(first_parameter_index_,
                                parameter_count,
                                first_stack_local_index_,
@@ skipping 8277 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart