Avoid caching thread in parser.

runtime/vm/parser.h

 // 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.
 
 #ifndef VM_PARSER_H_
 #define VM_PARSER_H_
 
 #include "include/dart_api.h"
 
 #include "platform/assert.h"
@@ skipping 23 matching lines @@
 class ClassDesc;
 struct MemberDesc;
 struct ParamList;
 struct QualIdent;
 struct TopLevel;
 
 // The class ParsedFunction holds the result of parsing a function.
 class ParsedFunction : public ZoneAllocated {
  public:
   ParsedFunction(Thread* thread, const Function& function)
-      : thread_(thread),
+      : isolate_(thread->isolate()),
         function_(function),
         code_(Code::Handle(zone(), function.unoptimized_code())),
         node_sequence_(NULL),
         regexp_compile_data_(NULL),
         instantiator_(NULL),
         default_parameter_values_(Array::ZoneHandle(zone(), Array::null())),
         current_context_var_(NULL),
         expression_temp_var_(NULL),
         finally_return_temp_var_(NULL),
         deferred_prefixes_(new ZoneGrowableArray<const LibraryPrefix*>()),
@@ skipping 88 matching lines @@
     return (num_copied_params_ == 0)
         ? function().num_fixed_parameters() : 0;
   }
 
   void AllocateVariables();
   void AllocateIrregexpVariables(intptr_t num_stack_locals);
 
   void record_await() { have_seen_await_expr_ = true; }
   bool have_seen_await() const { return have_seen_await_expr_; }
 
-  Thread* thread() const { return thread_; }
-  Isolate* isolate() const { return thread()->isolate(); }
-  Zone* zone() const { return thread()->zone(); }
+  Isolate* isolate() const { return isolate_; }
+  Zone* zone() const { return isolate()->current_zone(); }
 
  private:
-  Thread* thread_;
+  Isolate* isolate_;
   const Function& function_;
   Code& code_;
   SequenceNode* node_sequence_;
   RegExpCompileData* regexp_compile_data_;
   LocalVariable* instantiator_;
   Array& default_parameter_values_;
   LocalVariable* current_context_var_;
   LocalVariable* expression_temp_var_;
   LocalVariable* finally_return_temp_var_;
   ZoneGrowableArray<const LibraryPrefix*>* deferred_prefixes_;
@@ skipping 621 matching lines @@
       ArgumentListNode* arguments);
 
   void AddEqualityNullCheck();
 
   AstNode* BuildClosureCall(intptr_t token_pos,
                             AstNode* closure,
                             ArgumentListNode* arguments);
 
   RawInstance* TryCanonicalize(const Instance& instance, intptr_t token_pos);
 
-  Thread* thread() const { return thread_; }
-  Isolate* isolate() const { return thread()->isolate(); }
-  Zone* zone() const { return thread()->zone(); }
+  Isolate* isolate() const { return isolate_; }
+  Zone* zone() const { return isolate()->current_zone(); }
 
-  Thread* thread_;  // Cached current thread.
+  Isolate* isolate_;  // Cached current isolate.
 
   Script& script_;
   TokenStream::Iterator tokens_iterator_;
   Token::Kind token_kind_;  // Cached token kind for current token.
   Block* current_block_;
 
   // is_top_level_ is true if parsing the "top level" of a compilation unit,
   // that is class definitions, function type aliases, global functions,
   // global variables.
   bool is_top_level_;
@@ skipping 46 matching lines @@
 
   // Indentation of parser trace.
   intptr_t trace_indent_;
 
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };
 
 }  // namespace dart
 
 #endif  // VM_PARSER_H_