Fix data races caused by compiler stats counters in the parser.

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 "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 46 matching lines @@
       if (script.HasSource()) {
         intptr_t line, column;
         script.GetTokenLocation(token_pos, &line, &column);
         PrintIndent();
         OS::Print("%s (line %" Pd ", col %" Pd ", token %" Pd ")\n",
                   msg, line, column, token_pos);
       }
       indent_++;
     }
   }
-  ~TraceParser() { indent_--; }
+  ~TraceParser() { if (FLAG_trace_parser) indent_--; }
  private:
   void PrintIndent() {
     for (int i = 0; i < indent_; i++) { OS::Print(". "); }
   }
   static int indent_;
 };
 
 int TraceParser::indent_ = 0;
 
 #define TRACE_PARSER(s) \
@@ skipping 260 matching lines @@
 }
 
 
 void Parser::set_current_class(const Class& value) {
   current_class_ = value.raw();
 }
 
 
 void Parser::SetPosition(intptr_t position) {
   if (position < TokenPos() && position != 0) {
-    CompilerStats::num_tokens_rewind += (TokenPos() - position);
+    if (FLAG_compiler_stats) {
+      CompilerStats::num_tokens_rewind += (TokenPos() - position);
+    }
   }
   tokens_iterator_.SetCurrentPosition(position);
   token_kind_ = Token::kILLEGAL;
 }
 
 
 void Parser::ParseCompilationUnit(const Library& library,
                                   const Script& script) {
   ASSERT(Isolate::Current()->long_jump_base()->IsSafeToJump());
   TimerScope timer(FLAG_compiler_stats, &CompilerStats::parser_timer);
   Parser parser(script, library, 0);
   parser.ParseTopLevel();
 }
 
 
 Token::Kind Parser::CurrentToken() {
   if (token_kind_ == Token::kILLEGAL) {
     token_kind_ = tokens_iterator_.CurrentTokenKind();
     if (token_kind_ == Token::kERROR) {
       ErrorMsg(TokenPos(), "%s", CurrentLiteral()->ToCString());
     }
   }
-  CompilerStats::num_token_checks++;
+  if (FLAG_compiler_stats) {
+    CompilerStats::num_token_checks++;
+  }
   return token_kind_;
 }
 
 
 Token::Kind Parser::LookaheadToken(int num_tokens) {
-  CompilerStats::num_tokens_lookahead++;
-  CompilerStats::num_token_checks++;
+  if (FLAG_compiler_stats) {
+    CompilerStats::num_tokens_lookahead++;
+    CompilerStats::num_token_checks++;
+  }
   return tokens_iterator_.LookaheadTokenKind(num_tokens);
 }
 
 
 String* Parser::CurrentLiteral() const {
   String& result = String::ZoneHandle();
   result = tokens_iterator_.CurrentLiteral();
   return &result;
 }
 
@@ skipping 10114 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart