Be less aggressive in sharing contexts between scopes so that sibling contexts

runtime/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 "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 202 matching lines @@
   } else {
     // Parameter i will be at fp[kFirstLocalSlotFromFp - i] and local variable
     // j will be at fp[kFirstLocalSlotFromFp - num_params - j].
     first_parameter_index_ = kFirstLocalSlotFromFp;
     first_stack_local_index_ = first_parameter_index_ - num_params;
     num_copied_params_ = num_params;
   }
 
   // Allocate parameters and local variables, either in the local frame or
   // in the context(s).
-  LocalScope* context_owner = NULL;  // No context needed yet.
   bool found_captured_variables = false;
   int next_free_frame_index =
       scope->AllocateVariables(first_parameter_index_,
                                num_params,
                                first_stack_local_index_,
-                               scope,
-                               &context_owner,
+                               NULL,
                                &found_captured_variables);
 
   // Frame indices are relative to the frame pointer and are decreasing.
   ASSERT(next_free_frame_index <= first_stack_local_index_);
   num_stack_locals_ = first_stack_local_index_ - next_free_frame_index;
 }
 
 
 struct CatchParamDesc {
   CatchParamDesc()
@@ skipping 9163 matching lines @@
 
 
     // if (:controller.add[Stream](expr)) {
     //   return;
     // }
     // await_marker;
     // continuation_return;
     // restore saved_try_context
 
     SequenceNode* true_branch =
-        new(Z) SequenceNode(Scanner::kNoSourcePos, current_block_->scope);
+        new(Z) SequenceNode(Scanner::kNoSourcePos, NULL);
     AstNode* return_from_generator = new(Z) ReturnNode(yield_pos);
     true_branch->Add(return_from_generator);
     AddNodeForFinallyInlining(return_from_generator);
     AstNode* if_is_cancelled =
        new(Z) IfNode(Scanner::kNoSourcePos, add_call, true_branch, NULL);
     yield->AddNode(if_is_cancelled);
 
     AwaitMarkerNode* await_marker = new(Z) AwaitMarkerNode();
     await_marker->set_scope(current_block_->scope);
     yield->AddNode(await_marker);
@@ skipping 3798 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart