Experimental parser: merge r19949

src/preparser.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 37 matching lines @@
 // Usually defined in math.h, but not in MSVC until VS2013+.
 // Abstracted to work
 int isfinite(double value);
 
 }  // namespace std
 #endif
 
 namespace v8 {
 namespace internal {
 
+
+void PreParserTraits::CheckStrictModeLValue(PreParserExpression expression,
+                                            bool* ok) {
+  if (expression.IsIdentifier() &&
+      expression.AsIdentifier().IsEvalOrArguments()) {
+    pre_parser_->ReportMessage("strict_eval_arguments",
+                               Vector<const char*>::empty());
+    *ok = false;
+  }
+}
+
+
 void PreParserTraits::ReportMessageAt(Scanner::Location location,
                                       const char* message,
                                       Vector<const char*> args) {
   ReportMessageAt(location.beg_pos,
                   location.end_pos,
                   message,
                   args.length() > 0 ? args[0] : NULL);
 }
 
 
@@ skipping 16 matching lines @@
 PreParserIdentifier PreParserTraits::GetSymbol(Scanner* scanner) {
   pre_parser_->LogSymbol();
   if (scanner->current_token() == Token::FUTURE_RESERVED_WORD) {
     return PreParserIdentifier::FutureReserved();
   } else if (scanner->current_token() ==
              Token::FUTURE_STRICT_RESERVED_WORD) {
     return PreParserIdentifier::FutureStrictReserved();
   } else if (scanner->current_token() == Token::YIELD) {
     return PreParserIdentifier::Yield();
   }
-  if (scanner->is_literal_ascii()) {
-    // Detect strict-mode poison words.
-    if (scanner->literal_length() == 4 &&
-        !strncmp(scanner->literal_ascii_string().start(), "eval", 4)) {
-      return PreParserIdentifier::Eval();
-    }
-    if (scanner->literal_length() == 9 &&
-        !strncmp(scanner->literal_ascii_string().start(), "arguments", 9)) {
-      return PreParserIdentifier::Arguments();
-    }
+  if (scanner->UnescapedLiteralMatches("eval", 4)) {
+    return PreParserIdentifier::Eval();
+  }
+  if (scanner->UnescapedLiteralMatches("arguments", 9)) {
+    return PreParserIdentifier::Arguments();
   }
   return PreParserIdentifier::Default();
 }
 
 
 PreParserExpression PreParserTraits::ExpressionFromString(
     int pos, Scanner* scanner, PreParserFactory* factory) {
-  const int kUseStrictLength = 10;
-  const char* kUseStrictChars = "use strict";
   pre_parser_->LogSymbol();
-  if (scanner->is_literal_ascii() &&
-      scanner->literal_length() == kUseStrictLength &&
-      !scanner->literal_contains_escapes() &&
-      !strncmp(scanner->literal_ascii_string().start(), kUseStrictChars,
-               kUseStrictLength)) {
+  if (scanner->UnescapedLiteralMatches("use strict", 10)) {
     return PreParserExpression::UseStrictStringLiteral();
   }
   return PreParserExpression::StringLiteral();
 }
 
 
-PreParserExpression PreParserTraits::ParseObjectLiteral(bool* ok) {
-  return pre_parser_->ParseObjectLiteral(ok);
-}
-
-
-PreParserExpression PreParserTraits::ParseAssignmentExpression(bool accept_IN,
-                                                               bool* ok) {
-  return pre_parser_->ParseAssignmentExpression(accept_IN, ok);
-}
-
-
 PreParserExpression PreParserTraits::ParseV8Intrinsic(bool* ok) {
   return pre_parser_->ParseV8Intrinsic(ok);
 }
 
 
+PreParserExpression PreParserTraits::ParseFunctionLiteral(
+    PreParserIdentifier name,
+    Scanner::Location function_name_location,
+    bool name_is_strict_reserved,
+    bool is_generator,
+    int function_token_position,
+    FunctionLiteral::FunctionType type,
+    bool* ok) {
+  return pre_parser_->ParseFunctionLiteral(
+      name, function_name_location, name_is_strict_reserved, is_generator,
+      function_token_position, type, ok);
+}
+
+
+PreParserExpression PreParserTraits::ParseConditionalExpression(bool accept_IN,
+                                                                bool* ok) {
+  return pre_parser_->ParseConditionalExpression(accept_IN, ok);
+}
+
+
 PreParser::PreParseResult PreParser::PreParseLazyFunction(
-    LanguageMode mode, bool is_generator, ParserRecorder* log) {
+    StrictMode strict_mode, bool is_generator, ParserRecorder* log) {
   log_ = log;
   // Lazy functions always have trivial outer scopes (no with/catch scopes).
   PreParserScope top_scope(scope_, GLOBAL_SCOPE);
   FunctionState top_state(&function_state_, &scope_, &top_scope);
-  scope_->SetLanguageMode(mode);
+  scope_->SetStrictMode(strict_mode);
   PreParserScope function_scope(scope_, FUNCTION_SCOPE);
   FunctionState function_state(&function_state_, &scope_, &function_scope);
   function_state.set_is_generator(is_generator);
   ASSERT_EQ(Token::LBRACE, scanner()->current_token());
   bool ok = true;
   int start_position = peek_position();
   ParseLazyFunctionLiteralBody(&ok);
   if (stack_overflow()) return kPreParseStackOverflow;
   if (!ok) {
     ReportUnexpectedToken(scanner()->current_token());
   } else {
     ASSERT_EQ(Token::RBRACE, scanner()->peek());
-    if (!scope_->is_classic_mode()) {
+    if (scope_->strict_mode() == STRICT) {
       int end_pos = scanner()->location().end_pos;
       CheckOctalLiteral(start_position, end_pos, &ok);
     }
   }
   return kPreParseSuccess;
 }
 
 
 // Preparsing checks a JavaScript program and emits preparse-data that helps
 // a later parsing to be faster.
@@ skipping 46 matching lines @@
   //   (Statement)* <end_token>
 
   bool directive_prologue = true;
   while (peek() != end_token) {
     if (directive_prologue && peek() != Token::STRING) {
       directive_prologue = false;
     }
     Statement statement = ParseSourceElement(CHECK_OK);
     if (directive_prologue) {
       if (statement.IsUseStrictLiteral()) {
-        scope_->SetLanguageMode(allow_harmony_scoping() ?
-                                EXTENDED_MODE : STRICT_MODE);
+        scope_->SetStrictMode(STRICT);
       } else if (!statement.IsStringLiteral()) {
         directive_prologue = false;
       }
     }
   }
   return kUnknownSourceElements;
 }
 
 
 #undef CHECK_OK
@@ skipping 73 matching lines @@
     case Token::THROW:
       return ParseThrowStatement(ok);
 
     case Token::TRY:
       return ParseTryStatement(ok);
 
     case Token::FUNCTION: {
       Scanner::Location start_location = scanner()->peek_location();
       Statement statement = ParseFunctionDeclaration(CHECK_OK);
       Scanner::Location end_location = scanner()->location();
-      if (!scope_->is_classic_mode()) {
+      if (strict_mode() == STRICT) {
         PreParserTraits::ReportMessageAt(start_location.beg_pos,
                                          end_location.end_pos,
                                          "strict_function",
                                          NULL);
         *ok = false;
         return Statement::Default();
       } else {
         return statement;
       }
     }
 
     case Token::DEBUGGER:
       return ParseDebuggerStatement(ok);
 
     default:
       return ParseExpressionOrLabelledStatement(ok);
   }
 }
 
 
 PreParser::Statement PreParser::ParseFunctionDeclaration(bool* ok) {
   // FunctionDeclaration ::
   //   'function' Identifier '(' FormalParameterListopt ')' '{' FunctionBody '}'
   // GeneratorDeclaration ::
   //   'function' '*' Identifier '(' FormalParameterListopt ')'
   //      '{' FunctionBody '}'
   Expect(Token::FUNCTION, CHECK_OK);
-
+  int pos = position();
   bool is_generator = allow_generators() && Check(Token::MUL);
   bool is_strict_reserved = false;
   Identifier name = ParseIdentifierOrStrictReservedWord(
       &is_strict_reserved, CHECK_OK);
   ParseFunctionLiteral(name,
                        scanner()->location(),
                        is_strict_reserved,
                        is_generator,
+                       pos,
+                       FunctionLiteral::DECLARATION,
                        CHECK_OK);
   return Statement::FunctionDeclaration();
 }
 
 
 PreParser::Statement PreParser::ParseBlock(bool* ok) {
   // Block ::
   //   '{' Statement* '}'
 
   // Note that a Block does not introduce a new execution scope!
   // (ECMA-262, 3rd, 12.2)
   //
   Expect(Token::LBRACE, CHECK_OK);
   while (peek() != Token::RBRACE) {
-    if (scope_->is_extended_mode()) {
+    if (FLAG_harmony_scoping && strict_mode() == STRICT) {
       ParseSourceElement(CHECK_OK);
     } else {
       ParseStatement(CHECK_OK);
     }
   }
   Expect(Token::RBRACE, ok);
   return Statement::Default();
 }
 
 
@@ skipping 39 matching lines @@
   if (peek() == Token::VAR) {
     Consume(Token::VAR);
   } else if (peek() == Token::CONST) {
     // TODO(ES6): The ES6 Draft Rev4 section 12.2.2 reads:
     //
     // ConstDeclaration : const ConstBinding (',' ConstBinding)* ';'
     //
     // * It is a Syntax Error if the code that matches this production is not
     //   contained in extended code.
     //
-    // However disallowing const in classic mode will break compatibility with
+    // However disallowing const in sloppy mode will break compatibility with
     // existing pages. Therefore we keep allowing const with the old
-    // non-harmony semantics in classic mode.
+    // non-harmony semantics in sloppy mode.
     Consume(Token::CONST);
-    switch (scope_->language_mode()) {
-      case CLASSIC_MODE:
-        break;
-      case STRICT_MODE: {
+    if (strict_mode() == STRICT) {
+      if (FLAG_harmony_scoping) {
+        if (var_context != kSourceElement && var_context != kForStatement) {
+          ReportMessageAt(scanner()->peek_location(), "unprotected_const");
+          *ok = false;
+          return Statement::Default();
+        }
+        require_initializer = true;
+      } else {
         Scanner::Location location = scanner()->peek_location();
         ReportMessageAt(location, "strict_const");
         *ok = false;
         return Statement::Default();
       }
-      case EXTENDED_MODE:
-        if (var_context != kSourceElement &&
-            var_context != kForStatement) {
-          ReportMessageAt(scanner()->peek_location(), "unprotected_const");
-          *ok = false;
-          return Statement::Default();
-        }
-        require_initializer = true;
-        break;
     }
   } else if (peek() == Token::LET) {
     // ES6 Draft Rev4 section 12.2.1:
     //
     // LetDeclaration : let LetBindingList ;
     //
     // * It is a Syntax Error if the code that matches this production is not
     //   contained in extended code.
-    if (!scope_->is_extended_mode()) {
+    //
+    // TODO(rossberg): make 'let' a legal identifier in sloppy mode.
+    if (!FLAG_harmony_scoping || strict_mode() == SLOPPY) {
       ReportMessageAt(scanner()->peek_location(), "illegal_let");
       *ok = false;
       return Statement::Default();
     }
     Consume(Token::LET);
     if (var_context != kSourceElement &&
         var_context != kForStatement) {
       ReportMessageAt(scanner()->peek_location(), "unprotected_let");
       *ok = false;
       return Statement::Default();
@@ skipping 32 matching lines @@
 
   bool starts_with_identifier = peek_any_identifier();
   Expression expr = ParseExpression(true, CHECK_OK);
   // Even if the expression starts with an identifier, it is not necessarily an
   // identifier. For example, "foo + bar" starts with an identifier but is not
   // an identifier.
   if (starts_with_identifier && expr.IsIdentifier() && peek() == Token::COLON) {
     // Expression is a single identifier, and not, e.g., a parenthesized
     // identifier.
     ASSERT(!expr.AsIdentifier().IsFutureReserved());
-    ASSERT(scope_->is_classic_mode() ||
+    ASSERT(strict_mode() == SLOPPY ||
            (!expr.AsIdentifier().IsFutureStrictReserved() &&
             !expr.AsIdentifier().IsYield()));
     Consume(Token::COLON);
     return ParseStatement(ok);
     // Preparsing is disabled for extensions (because the extension details
     // aren't passed to lazily compiled functions), so we don't
     // accept "native function" in the preparser.
   }
   // Parsed expression statement.
   ExpectSemicolon(CHECK_OK);
@@ skipping 77 matching lines @@
   }
   ExpectSemicolon(CHECK_OK);
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseWithStatement(bool* ok) {
   // WithStatement ::
   //   'with' '(' Expression ')' Statement
   Expect(Token::WITH, CHECK_OK);
-  if (!scope_->is_classic_mode()) {
+  if (strict_mode() == STRICT) {
     ReportMessageAt(scanner()->location(), "strict_mode_with");
     *ok = false;
     return Statement::Default();
   }
   Expect(Token::LPAREN, CHECK_OK);
   ParseExpression(true, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   PreParserScope with_scope(scope_, WITH_SCOPE);
   BlockState block_state(&scope_, &with_scope);
@@ skipping 198 matching lines @@
 
 
 #undef CHECK_OK
 #define CHECK_OK  ok);                     \
   if (!*ok) return Expression::Default();  \
   ((void)0
 #define DUMMY )  // to make indentation work
 #undef DUMMY
 
 
-// Precedence = 2
-PreParser::Expression PreParser::ParseAssignmentExpression(bool accept_IN,
-                                                           bool* ok) {
-  // AssignmentExpression ::
-  //   ConditionalExpression
-  //   YieldExpression
-  //   LeftHandSideExpression AssignmentOperator AssignmentExpression
-
-  if (function_state_->is_generator() && peek() == Token::YIELD) {
-    return ParseYieldExpression(ok);
-  }
-
-  Scanner::Location before = scanner()->peek_location();
-  Expression expression = ParseConditionalExpression(accept_IN, CHECK_OK);
-
-  if (!Token::IsAssignmentOp(peek())) {
-    // Parsed conditional expression only (no assignment).
-    return expression;
-  }
-
-  if (!scope_->is_classic_mode() &&
-      expression.IsIdentifier() &&
-      expression.AsIdentifier().IsEvalOrArguments()) {
-    Scanner::Location after = scanner()->location();
-    PreParserTraits::ReportMessageAt(before.beg_pos, after.end_pos,
-                                     "strict_eval_arguments", NULL);
-    *ok = false;
-    return Expression::Default();
-  }
-
-  Token::Value op = Next();  // Get assignment operator.
-  ParseAssignmentExpression(accept_IN, CHECK_OK);
-
-  if ((op == Token::ASSIGN) && expression.IsThisProperty()) {
-    function_state_->AddProperty();
-  }
-
-  return Expression::Default();
-}
-
-
-// Precedence = 3
-PreParser::Expression PreParser::ParseYieldExpression(bool* ok) {
-  // YieldExpression ::
-  //   'yield' '*'? AssignmentExpression
-  Consume(Token::YIELD);
-  Check(Token::MUL);
-
-  ParseAssignmentExpression(false, CHECK_OK);
-
-  return Expression::Default();
-}
-
-
 // Precedence = 3
 PreParser::Expression PreParser::ParseConditionalExpression(bool accept_IN,
                                                             bool* ok) {
   // ConditionalExpression ::
   //   LogicalOrExpression
   //   LogicalOrExpression '?' AssignmentExpression ':' AssignmentExpression
 
   // We start using the binary expression parser for prec >= 4 only!
   Expression expression = ParseBinaryExpression(4, accept_IN, CHECK_OK);
   if (peek() != Token::CONDITIONAL) return expression;
@@ skipping 38 matching lines @@
   //   '~' UnaryExpression
   //   '!' UnaryExpression
 
   Token::Value op = peek();
   if (Token::IsUnaryOp(op)) {
     op = Next();
     ParseUnaryExpression(ok);
     return Expression::Default();
   } else if (Token::IsCountOp(op)) {
     op = Next();
-    Scanner::Location before = scanner()->peek_location();
     Expression expression = ParseUnaryExpression(CHECK_OK);
-    if (!scope_->is_classic_mode() &&
-        expression.IsIdentifier() &&
-        expression.AsIdentifier().IsEvalOrArguments()) {
-      Scanner::Location after = scanner()->location();
-      PreParserTraits::ReportMessageAt(before.beg_pos, after.end_pos,
-                                       "strict_eval_arguments", NULL);
-      *ok = false;
+    if (strict_mode() == STRICT) {
+      CheckStrictModeLValue(expression, CHECK_OK);
     }
     return Expression::Default();
   } else {
     return ParsePostfixExpression(ok);
   }
 }
 
 
 PreParser::Expression PreParser::ParsePostfixExpression(bool* ok) {
   // PostfixExpression ::
   //   LeftHandSideExpression ('++' | '--')?
 
-  Scanner::Location before = scanner()->peek_location();
   Expression expression = ParseLeftHandSideExpression(CHECK_OK);
   if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
       Token::IsCountOp(peek())) {
-    if (!scope_->is_classic_mode() &&
-        expression.IsIdentifier() &&
-        expression.AsIdentifier().IsEvalOrArguments()) {
-      Scanner::Location after = scanner()->location();
-      PreParserTraits::ReportMessageAt(before.beg_pos, after.end_pos,
-                                       "strict_eval_arguments", NULL);
-      *ok = false;
-      return Expression::Default();
+    if (strict_mode() == STRICT) {
+      CheckStrictModeLValue(expression, CHECK_OK);
     }
     Next();
     return Expression::Default();
   }
   return expression;
 }
 
 
 PreParser::Expression PreParser::ParseLeftHandSideExpression(bool* ok) {
   // LeftHandSideExpression ::
@@ skipping 68 matching lines @@
   //     ('[' Expression ']' | '.' Identifier | Arguments)*
 
   // The '[' Expression ']' and '.' Identifier parts are parsed by
   // ParseMemberExpressionContinuation, and the Arguments part is parsed by the
   // caller.
 
   // Parse the initial primary or function expression.
   Expression result = Expression::Default();
   if (peek() == Token::FUNCTION) {
     Consume(Token::FUNCTION);
-
+    int function_token_position = position();
     bool is_generator = allow_generators() && Check(Token::MUL);
     Identifier name = Identifier::Default();
     bool is_strict_reserved_name = false;
     Scanner::Location function_name_location = Scanner::Location::invalid();
+    FunctionLiteral::FunctionType function_type =
+        FunctionLiteral::ANONYMOUS_EXPRESSION;
     if (peek_any_identifier()) {
       name = ParseIdentifierOrStrictReservedWord(&is_strict_reserved_name,
                                                  CHECK_OK);
       function_name_location = scanner()->location();
+      function_type = FunctionLiteral::NAMED_EXPRESSION;
     }
     result = ParseFunctionLiteral(name,
                                   function_name_location,
                                   is_strict_reserved_name,
                                   is_generator,
+                                  function_token_position,
+                                  function_type,
                                   CHECK_OK);
   } else {
     result = ParsePrimaryExpression(CHECK_OK);
   }
   result = ParseMemberExpressionContinuation(result, CHECK_OK);
   return result;
 }
 
 
 PreParser::Expression PreParser::ParseMemberExpressionContinuation(
@@ skipping 25 matching lines @@
       }
       default:
         return expression;
     }
   }
   ASSERT(false);
   return PreParserExpression::Default();
 }
 
 
-PreParser::Expression PreParser::ParseObjectLiteral(bool* ok) {
-  // ObjectLiteral ::
-  //   '{' (
-  //       ((IdentifierName | String | Number) ':' AssignmentExpression)
-  //     | (('get' | 'set') (IdentifierName | String | Number) FunctionLiteral)
-  //    )*[','] '}'
-
-  ObjectLiteralChecker checker(this, scope_->language_mode());
-
-  Expect(Token::LBRACE, CHECK_OK);
-  while (peek() != Token::RBRACE) {
-    Token::Value next = peek();
-    switch (next) {
-      case Token::IDENTIFIER:
-      case Token::FUTURE_RESERVED_WORD:
-      case Token::FUTURE_STRICT_RESERVED_WORD: {
-        bool is_getter = false;
-        bool is_setter = false;
-        ParseIdentifierNameOrGetOrSet(&is_getter, &is_setter, CHECK_OK);
-        if ((is_getter || is_setter) && peek() != Token::COLON) {
-            Token::Value name = Next();
-            bool is_keyword = Token::IsKeyword(name);
-            if (name != Token::IDENTIFIER &&
-                name != Token::FUTURE_RESERVED_WORD &&
-                name != Token::FUTURE_STRICT_RESERVED_WORD &&
-                name != Token::NUMBER &&
-                name != Token::STRING &&
-                !is_keyword) {
-              *ok = false;
-              return Expression::Default();
-            }
-            if (!is_keyword) {
-              LogSymbol();
-            }
-            PropertyKind type = is_getter ? kGetterProperty : kSetterProperty;
-            checker.CheckProperty(name, type, CHECK_OK);
-            ParseFunctionLiteral(Identifier::Default(),
-                                 scanner()->location(),
-                                 false,  // reserved words are allowed here
-                                 false,  // not a generator
-                                 CHECK_OK);
-            if (peek() != Token::RBRACE) {
-              Expect(Token::COMMA, CHECK_OK);
-            }
-            continue;  // restart the while
-        }
-        checker.CheckProperty(next, kValueProperty, CHECK_OK);
-        break;
-      }
-      case Token::STRING:
-        Consume(next);
-        checker.CheckProperty(next, kValueProperty, CHECK_OK);
-        LogSymbol();
-        break;
-      case Token::NUMBER:
-        Consume(next);
-        checker.CheckProperty(next, kValueProperty, CHECK_OK);
-        break;
-      default:
-        if (Token::IsKeyword(next)) {
-          Consume(next);
-          checker.CheckProperty(next, kValueProperty, CHECK_OK);
-          LogSymbol();
-        } else {
-          // Unexpected token.
-          *ok = false;
-          return Expression::Default();
-        }
-    }
-
-    Expect(Token::COLON, CHECK_OK);
-    ParseAssignmentExpression(true, CHECK_OK);
-
-    // TODO(1240767): Consider allowing trailing comma.
-    if (peek() != Token::RBRACE) Expect(Token::COMMA, CHECK_OK);
-  }
-  Expect(Token::RBRACE, CHECK_OK);
-
-  function_state_->NextMaterializedLiteralIndex();
-  return Expression::Default();
-}
-
-
-PreParser::Arguments PreParser::ParseArguments(bool* ok) {
-  // Arguments ::
-  //   '(' (AssignmentExpression)*[','] ')'
-
-  Expect(Token::LPAREN, ok);
-  if (!*ok) return -1;
-  bool done = (peek() == Token::RPAREN);
-  int argc = 0;
-  while (!done) {
-    ParseAssignmentExpression(true, ok);
-    if (!*ok) return -1;
-    argc++;
-    done = (peek() == Token::RPAREN);
-    if (!done) {
-      Expect(Token::COMMA, ok);
-      if (!*ok) return -1;
-    }
-  }
-  Expect(Token::RPAREN, ok);
-  return argc;
-}
-
 PreParser::Expression PreParser::ParseFunctionLiteral(
     Identifier function_name,
     Scanner::Location function_name_location,
     bool name_is_strict_reserved,
     bool is_generator,
+    int function_token_pos,
+    FunctionLiteral::FunctionType function_type,
     bool* ok) {
   // Function ::
   //   '(' FormalParameterList? ')' '{' FunctionBody '}'
 
   // Parse function body.
   ScopeType outer_scope_type = scope_->type();
   bool inside_with = scope_->inside_with();
   PreParserScope function_scope(scope_, FUNCTION_SCOPE);
   FunctionState function_state(&function_state_, &scope_, &function_scope);
   function_state.set_is_generator(is_generator);
@@ skipping 13 matching lines @@
     bool is_strict_reserved = false;
     Identifier param_name =
         ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
     if (!eval_args_error_loc.IsValid() && param_name.IsEvalOrArguments()) {
       eval_args_error_loc = scanner()->location();
     }
     if (!reserved_error_loc.IsValid() && is_strict_reserved) {
       reserved_error_loc = scanner()->location();
     }
 
-    int prev_value;
-    if (scanner()->is_literal_ascii()) {
-      prev_value =
-          duplicate_finder.AddAsciiSymbol(scanner()->literal_ascii_string(), 1);
-    } else {
-      prev_value =
-          duplicate_finder.AddUtf16Symbol(scanner()->literal_utf16_string(), 1);
-    }
+    int prev_value = scanner()->FindSymbol(&duplicate_finder, 1);
 
     if (!dupe_error_loc.IsValid() && prev_value != 0) {
       dupe_error_loc = scanner()->location();
     }
 
     done = (peek() == Token::RPAREN);
     if (!done) {
       Expect(Token::COMMA, CHECK_OK);
     }
   }
   Expect(Token::RPAREN, CHECK_OK);
 
   // See Parser::ParseFunctionLiteral for more information about lazy parsing
   // and lazy compilation.
   bool is_lazily_parsed = (outer_scope_type == GLOBAL_SCOPE &&
                            !inside_with && allow_lazy() &&
                            !parenthesized_function_);
   parenthesized_function_ = false;
 
   Expect(Token::LBRACE, CHECK_OK);
   if (is_lazily_parsed) {
     ParseLazyFunctionLiteralBody(CHECK_OK);
   } else {
     ParseSourceElements(Token::RBRACE, ok);
   }
   Expect(Token::RBRACE, CHECK_OK);
 
   // Validate strict mode. We can do this only after parsing the function,
   // since the function can declare itself strict.
-  if (!scope_->is_classic_mode()) {
+  if (strict_mode() == STRICT) {
     if (function_name.IsEvalOrArguments()) {
       ReportMessageAt(function_name_location, "strict_eval_arguments");
       *ok = false;
       return Expression::Default();
     }
     if (name_is_strict_reserved) {
       ReportMessageAt(function_name_location, "unexpected_strict_reserved");
       *ok = false;
       return Expression::Default();
     }
@@ skipping 17 matching lines @@
     CheckOctalLiteral(start_position, end_position, CHECK_OK);
     return Expression::StrictFunction();
   }
 
   return Expression::Default();
 }
 
 
 void PreParser::ParseLazyFunctionLiteralBody(bool* ok) {
   int body_start = position();
-  log_->PauseRecording();
+  bool is_logging = log_->ShouldLogSymbols();
+  if (is_logging) log_->PauseRecording();
   ParseSourceElements(Token::RBRACE, ok);
-  log_->ResumeRecording();
+  if (is_logging) log_->ResumeRecording();
   if (!*ok) return;
 
   // Position right after terminal '}'.
   ASSERT_EQ(Token::RBRACE, scanner()->peek());
   int body_end = scanner()->peek_location().end_pos;
   log_->LogFunction(body_start, body_end,
                     function_state_->materialized_literal_count(),
                     function_state_->expected_property_count(),
-                    scope_->language_mode());
+                    strict_mode());
 }
 
 
 PreParser::Expression PreParser::ParseV8Intrinsic(bool* ok) {
   // CallRuntime ::
   //   '%' Identifier Arguments
   Expect(Token::MOD, CHECK_OK);
   if (!allow_natives_syntax()) {
     *ok = false;
     return Expression::Default();
   }
   // Allow "eval" or "arguments" for backward compatibility.
   ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
   ParseArguments(ok);
 
   return Expression::Default();
 }
 
 #undef CHECK_OK
 
 
 void PreParser::LogSymbol() {
-  int identifier_pos = position();
-  if (scanner()->is_literal_ascii()) {
-    log_->LogAsciiSymbol(identifier_pos, scanner()->literal_ascii_string());
-  } else {
-    log_->LogUtf16Symbol(identifier_pos, scanner()->literal_utf16_string());
+  if (log_->ShouldLogSymbols()) {
+    scanner()->LogSymbol(log_, position());
   }
 }
 
 
 } }  // v8::internal