Experimental parser: merge to r19637

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 24 matching lines @@
 #include "conversions-inl.h"
 #include "globals.h"
 #include "hashmap.h"
 #include "list.h"
 #include "preparse-data-format.h"
 #include "preparse-data.h"
 #include "preparser.h"
 #include "unicode.h"
 #include "utils.h"
 
-#if V8_CC_MSVC && (_MSC_VER < 1800)
+#if V8_LIBC_MSVCRT && (_MSC_VER < 1800)
 namespace std {
 
 // 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::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);
+}
+
+
+void PreParserTraits::ReportMessageAt(Scanner::Location location,
+                                      const char* type,
+                                      const char* name_opt) {
+  pre_parser_->log_
+      ->LogMessage(location.beg_pos, location.end_pos, type, name_opt);
+}
+
+
+void PreParserTraits::ReportMessageAt(int start_pos,
+                                      int end_pos,
+                                      const char* type,
+                                      const char* name_opt) {
+  pre_parser_->log_->LogMessage(start_pos, end_pos, type, name_opt);
+}
+
+
+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();
+    }
+  }
+  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)) {
+    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);
+}
+
+
 PreParser::PreParseResult PreParser::PreParseLazyFunction(
     LanguageMode mode, bool is_generator, ParserRecorder* log) {
   log_ = log;
   // Lazy functions always have trivial outer scopes (no with/catch scopes).
-  Scope top_scope(&scope_, kTopLevelScope);
-  set_language_mode(mode);
-  Scope function_scope(&scope_, kFunctionScope);
-  function_scope.set_is_generator(is_generator);
+  PreParserScope top_scope(scope_, GLOBAL_SCOPE);
+  FunctionState top_state(&function_state_, &scope_, &top_scope);
+  scope_->SetLanguageMode(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 (!is_classic_mode()) {
+    if (!scope_->is_classic_mode()) {
       int end_pos = scanner()->location().end_pos;
       CheckOctalLiteral(start_position, end_pos, &ok);
-      if (ok) {
-        CheckDelayedStrictModeViolation(start_position, end_pos, &ok);
-      }
     }
   }
   return kPreParseSuccess;
 }
 
 
 // Preparsing checks a JavaScript program and emits preparse-data that helps
 // a later parsing to be faster.
 // See preparser-data.h for the data.
 
 // The PreParser checks that the syntax follows the grammar for JavaScript,
 // and collects some information about the program along the way.
 // The grammar check is only performed in order to understand the program
 // sufficiently to deduce some information about it, that can be used
 // to speed up later parsing. Finding errors is not the goal of pre-parsing,
 // rather it is to speed up properly written and correct programs.
 // That means that contextual checks (like a label being declared where
 // it is used) are generally omitted.
 
-void PreParser::ReportUnexpectedToken(Token::Value token) {
-  // We don't report stack overflows here, to avoid increasing the
-  // stack depth even further.  Instead we report it after parsing is
-  // over, in ParseProgram.
-  if (token == Token::ILLEGAL && stack_overflow()) {
-    return;
-  }
-  ScannerBase::Location source_location = scanner()->location();
-
-  // Four of the tokens are treated specially
-  switch (token) {
-  case Token::EOS:
-    return ReportMessageAt(source_location, "unexpected_eos", NULL);
-  case Token::NUMBER:
-    return ReportMessageAt(source_location, "unexpected_token_number", NULL);
-  case Token::STRING:
-    return ReportMessageAt(source_location, "unexpected_token_string", NULL);
-  case Token::IDENTIFIER:
-    return ReportMessageAt(source_location,
-                           "unexpected_token_identifier", NULL);
-  case Token::FUTURE_RESERVED_WORD:
-    return ReportMessageAt(source_location, "unexpected_reserved", NULL);
-  case Token::FUTURE_STRICT_RESERVED_WORD:
-    return ReportMessageAt(source_location,
-                           "unexpected_strict_reserved", NULL);
-  default:
-    const char* name = Token::String(token);
-    ReportMessageAt(source_location, "unexpected_token", name);
-  }
-}
-
 
 #define CHECK_OK  ok);                      \
   if (!*ok) return kUnknownSourceElements;  \
   ((void)0
 #define DUMMY )  // to make indentation work
 #undef DUMMY
 
 
 PreParser::Statement PreParser::ParseSourceElement(bool* ok) {
   // (Ecma 262 5th Edition, clause 14):
@@ skipping 17 matching lines @@
       return ParseStatement(ok);
   }
 }
 
 
 PreParser::SourceElements PreParser::ParseSourceElements(int end_token,
                                                          bool* ok) {
   // SourceElements ::
   //   (Statement)* <end_token>
 
-  bool allow_directive_prologue = true;
+  bool directive_prologue = true;
   while (peek() != end_token) {
+    if (directive_prologue && peek() != Token::STRING) {
+      directive_prologue = false;
+    }
     Statement statement = ParseSourceElement(CHECK_OK);
-    if (allow_directive_prologue) {
+    if (directive_prologue) {
       if (statement.IsUseStrictLiteral()) {
-        set_language_mode(allow_harmony_scoping() ?
-                          EXTENDED_MODE : STRICT_MODE);
+        scope_->SetLanguageMode(allow_harmony_scoping() ?
+                                EXTENDED_MODE : STRICT_MODE);
       } else if (!statement.IsStringLiteral()) {
-        allow_directive_prologue = false;
+        directive_prologue = false;
       }
     }
   }
   return kUnknownSourceElements;
 }
 
 
 #undef CHECK_OK
 #define CHECK_OK  ok);                   \
   if (!*ok) return Statement::Default();  \
@@ skipping 68 matching lines @@
     case Token::SWITCH:
       return ParseSwitchStatement(ok);
 
     case Token::THROW:
       return ParseThrowStatement(ok);
 
     case Token::TRY:
       return ParseTryStatement(ok);
 
     case Token::FUNCTION: {
-      ScannerBase::Location start_location = scanner()->peek_location();
+      Scanner::Location start_location = scanner()->peek_location();
       Statement statement = ParseFunctionDeclaration(CHECK_OK);
-      ScannerBase::Location end_location = scanner()->location();
-      if (!is_classic_mode()) {
-        ReportMessageAt(start_location.beg_pos, end_location.end_pos,
-                        "strict_function", NULL);
+      Scanner::Location end_location = scanner()->location();
+      if (!scope_->is_classic_mode()) {
+        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);
 
   bool is_generator = allow_generators() && Check(Token::MUL);
-  Identifier identifier = ParseIdentifier(CHECK_OK);
-  ScannerBase::Location location = scanner()->location();
-
-  Expression function_value = ParseFunctionLiteral(is_generator, CHECK_OK);
-
-  if (function_value.IsStrictFunction() &&
-      !identifier.IsValidStrictVariable()) {
-    // Strict mode violation, using either reserved word or eval/arguments
-    // as name of strict function.
-    const char* type = "strict_function_name";
-    if (identifier.IsFutureStrictReserved() || identifier.IsYield()) {
-      type = "strict_reserved_word";
-    }
-    ReportMessageAt(location, type, NULL);
-    *ok = false;
-  }
+  bool is_strict_reserved = false;
+  Identifier name = ParseIdentifierOrStrictReservedWord(
+      &is_strict_reserved, CHECK_OK);
+  ParseFunctionLiteral(name,
+                       scanner()->location(),
+                       is_strict_reserved,
+                       is_generator,
+                       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 (is_extended_mode()) {
+    if (scope_->is_extended_mode()) {
       ParseSourceElement(CHECK_OK);
     } else {
       ParseStatement(CHECK_OK);
     }
   }
   Expect(Token::RBRACE, ok);
   return Statement::Default();
 }
 
 
@@ skipping 43 matching lines @@
     //
     // 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
     // existing pages. Therefore we keep allowing const with the old
     // non-harmony semantics in classic mode.
     Consume(Token::CONST);
-    switch (language_mode()) {
+    switch (scope_->language_mode()) {
       case CLASSIC_MODE:
         break;
       case STRICT_MODE: {
-        ScannerBase::Location location = scanner()->peek_location();
-        ReportMessageAt(location, "strict_const", NULL);
+        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) {
-          ScannerBase::Location location = scanner()->peek_location();
-          ReportMessageAt(location.beg_pos, location.end_pos,
-                          "unprotected_const", NULL);
+          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 (!is_extended_mode()) {
-      ScannerBase::Location location = scanner()->peek_location();
-      ReportMessageAt(location.beg_pos, location.end_pos,
-                      "illegal_let", NULL);
+    if (!scope_->is_extended_mode()) {
+      ReportMessageAt(scanner()->peek_location(), "illegal_let");
       *ok = false;
       return Statement::Default();
     }
     Consume(Token::LET);
     if (var_context != kSourceElement &&
         var_context != kForStatement) {
-      ScannerBase::Location location = scanner()->peek_location();
-      ReportMessageAt(location.beg_pos, location.end_pos,
-                      "unprotected_let", NULL);
+      ReportMessageAt(scanner()->peek_location(), "unprotected_let");
       *ok = false;
       return Statement::Default();
     }
   } else {
     *ok = false;
     return Statement::Default();
   }
 
   // The scope of a var/const declared variable anywhere inside a function
   // is the entire function (ECMA-262, 3rd, 10.1.3, and 12.2). The scope
   // of a let declared variable is the scope of the immediately enclosing
   // block.
   int nvars = 0;  // the number of variables declared
   do {
     // Parse variable name.
     if (nvars > 0) Consume(Token::COMMA);
-    Identifier identifier  = ParseIdentifier(CHECK_OK);
-    if (!is_classic_mode() && !identifier.IsValidStrictVariable()) {
-      StrictModeIdentifierViolation(scanner()->location(),
-                                    "strict_var_name",
-                                    identifier,
-                                    ok);
-      return Statement::Default();
-    }
+    ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
     nvars++;
     if (peek() == Token::ASSIGN || require_initializer) {
       Expect(Token::ASSIGN, CHECK_OK);
       ParseAssignmentExpression(var_context != kForStatement, CHECK_OK);
       if (decl_props != NULL) *decl_props = kHasInitializers;
     }
   } while (peek() == Token::COMMA);
 
   if (num_decl != NULL) *num_decl = nvars;
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseExpressionOrLabelledStatement(bool* ok) {
   // ExpressionStatement | LabelledStatement ::
   //   Expression ';'
   //   Identifier ':' Statement
 
+  bool starts_with_identifier = peek_any_identifier();
   Expression expr = ParseExpression(true, CHECK_OK);
-  if (expr.IsRawIdentifier()) {
+  // 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(is_classic_mode() ||
+    ASSERT(scope_->is_classic_mode() ||
            (!expr.AsIdentifier().IsFutureStrictReserved() &&
             !expr.AsIdentifier().IsYield()));
-    if (peek() == Token::COLON) {
-      Consume(Token::COLON);
-      return ParseStatement(ok);
-    }
+    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);
   return Statement::ExpressionStatement(expr);
 }
 
 
@@ skipping 17 matching lines @@
 PreParser::Statement PreParser::ParseContinueStatement(bool* ok) {
   // ContinueStatement ::
   //   'continue' [no line terminator] Identifier? ';'
 
   Expect(Token::CONTINUE, CHECK_OK);
   Token::Value tok = peek();
   if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
       tok != Token::SEMICOLON &&
       tok != Token::RBRACE &&
       tok != Token::EOS) {
-    ParseIdentifier(CHECK_OK);
+    // ECMA allows "eval" or "arguments" as labels even in strict mode.
+    ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
   }
   ExpectSemicolon(CHECK_OK);
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseBreakStatement(bool* ok) {
   // BreakStatement ::
   //   'break' [no line terminator] Identifier? ';'
 
   Expect(Token::BREAK, CHECK_OK);
   Token::Value tok = peek();
   if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
       tok != Token::SEMICOLON &&
       tok != Token::RBRACE &&
       tok != Token::EOS) {
-    ParseIdentifier(CHECK_OK);
+    // ECMA allows "eval" or "arguments" as labels even in strict mode.
+    ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
   }
   ExpectSemicolon(CHECK_OK);
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseReturnStatement(bool* ok) {
   // ReturnStatement ::
   //   'return' [no line terminator] Expression? ';'
 
@@ skipping 16 matching lines @@
   }
   ExpectSemicolon(CHECK_OK);
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseWithStatement(bool* ok) {
   // WithStatement ::
   //   'with' '(' Expression ')' Statement
   Expect(Token::WITH, CHECK_OK);
-  if (!is_classic_mode()) {
-    ScannerBase::Location location = scanner()->location();
-    ReportMessageAt(location, "strict_mode_with", NULL);
+  if (!scope_->is_classic_mode()) {
+    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);
 
-  Scope::InsideWith iw(scope_);
+  PreParserScope with_scope(scope_, WITH_SCOPE);
+  BlockState block_state(&scope_, &with_scope);
   ParseStatement(CHECK_OK);
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseSwitchStatement(bool* ok) {
   // SwitchStatement ::
   //   'switch' '(' Expression ')' '{' CaseClause* '}'
 
   Expect(Token::SWITCH, CHECK_OK);
@@ skipping 115 matching lines @@
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseThrowStatement(bool* ok) {
   // ThrowStatement ::
   //   'throw' [no line terminator] Expression ';'
 
   Expect(Token::THROW, CHECK_OK);
   if (scanner()->HasAnyLineTerminatorBeforeNext()) {
-    ScannerBase::Location pos = scanner()->location();
-    ReportMessageAt(pos, "newline_after_throw", NULL);
+    ReportMessageAt(scanner()->location(), "newline_after_throw");
     *ok = false;
     return Statement::Default();
   }
   ParseExpression(true, CHECK_OK);
   ExpectSemicolon(ok);
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseTryStatement(bool* ok) {
   // TryStatement ::
   //   'try' Block Catch
   //   'try' Block Finally
   //   'try' Block Catch Finally
   //
   // Catch ::
   //   'catch' '(' Identifier ')' Block
   //
   // Finally ::
   //   'finally' Block
 
-  // In preparsing, allow any number of catch/finally blocks, including zero
-  // of both.
-
   Expect(Token::TRY, CHECK_OK);
 
   ParseBlock(CHECK_OK);
 
-  bool catch_or_finally_seen = false;
-  if (peek() == Token::CATCH) {
+  Token::Value tok = peek();
+  if (tok != Token::CATCH && tok != Token::FINALLY) {
+    ReportMessageAt(scanner()->location(), "no_catch_or_finally");
+    *ok = false;
+    return Statement::Default();
+  }
+  if (tok == Token::CATCH) {
     Consume(Token::CATCH);
     Expect(Token::LPAREN, CHECK_OK);
-    Identifier id = ParseIdentifier(CHECK_OK);
-    if (!is_classic_mode() && !id.IsValidStrictVariable()) {
-      StrictModeIdentifierViolation(scanner()->location(),
-                                    "strict_catch_variable",
-                                    id,
-                                    ok);
-      return Statement::Default();
-    }
+    ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
     Expect(Token::RPAREN, CHECK_OK);
-    { Scope::InsideWith iw(scope_);
+    {
+      PreParserScope with_scope(scope_, WITH_SCOPE);
+      BlockState block_state(&scope_, &with_scope);
       ParseBlock(CHECK_OK);
     }
-    catch_or_finally_seen = true;
+    tok = peek();
   }
-  if (peek() == Token::FINALLY) {
+  if (tok == Token::FINALLY) {
     Consume(Token::FINALLY);
     ParseBlock(CHECK_OK);
-    catch_or_finally_seen = true;
-  }
-  if (!catch_or_finally_seen) {
-    *ok = false;
   }
   return Statement::Default();
 }
 
 
 PreParser::Statement PreParser::ParseDebuggerStatement(bool* ok) {
   // In ECMA-262 'debugger' is defined as a reserved keyword. In some browser
   // contexts this is used as a statement which invokes the debugger as if a
   // break point is present.
   // DebuggerStatement ::
   //   'debugger' ';'
 
   Expect(Token::DEBUGGER, CHECK_OK);
   ExpectSemicolon(ok);
   return Statement::Default();
 }
 
 
 #undef CHECK_OK
 #define CHECK_OK  ok);                     \
   if (!*ok) return Expression::Default();  \
   ((void)0
 #define DUMMY )  // to make indentation work
 #undef DUMMY
 
 
-// Precedence = 1
-PreParser::Expression PreParser::ParseExpression(bool accept_IN, bool* ok) {
-  // Expression ::
-  //   AssignmentExpression
-  //   Expression ',' AssignmentExpression
-
-  Expression result = ParseAssignmentExpression(accept_IN, CHECK_OK);
-  while (peek() == Token::COMMA) {
-    Expect(Token::COMMA, CHECK_OK);
-    ParseAssignmentExpression(accept_IN, CHECK_OK);
-    result = Expression::Default();
-  }
-  return result;
-}
-
-
 // Precedence = 2
 PreParser::Expression PreParser::ParseAssignmentExpression(bool accept_IN,
                                                            bool* ok) {
   // AssignmentExpression ::
   //   ConditionalExpression
   //   YieldExpression
   //   LeftHandSideExpression AssignmentOperator AssignmentExpression
 
-  if (scope_->is_generator() && peek() == Token::YIELD) {
+  if (function_state_->is_generator() && peek() == Token::YIELD) {
     return ParseYieldExpression(ok);
   }
 
-  ScannerBase::Location before = scanner()->peek_location();
+  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 (!is_classic_mode() &&
+  if (!scope_->is_classic_mode() &&
       expression.IsIdentifier() &&
       expression.AsIdentifier().IsEvalOrArguments()) {
-    ScannerBase::Location after = scanner()->location();
-    ReportMessageAt(before.beg_pos, after.end_pos,
-                    "strict_lhs_assignment", NULL);
+    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()) {
-    scope_->AddProperty();
+    function_state_->AddProperty();
   }
 
   return Expression::Default();
 }
 
 
 // Precedence = 3
 PreParser::Expression PreParser::ParseYieldExpression(bool* ok) {
   // YieldExpression ::
   //   'yield' '*'? AssignmentExpression
@@ skipping 57 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();
-    ScannerBase::Location before = scanner()->peek_location();
+    Scanner::Location before = scanner()->peek_location();
     Expression expression = ParseUnaryExpression(CHECK_OK);
-    if (!is_classic_mode() &&
+    if (!scope_->is_classic_mode() &&
         expression.IsIdentifier() &&
         expression.AsIdentifier().IsEvalOrArguments()) {
-      ScannerBase::Location after = scanner()->location();
-      ReportMessageAt(before.beg_pos, after.end_pos,
-                      "strict_lhs_prefix", NULL);
+      Scanner::Location after = scanner()->location();
+      PreParserTraits::ReportMessageAt(before.beg_pos, after.end_pos,
+                                       "strict_eval_arguments", NULL);
       *ok = false;
     }
     return Expression::Default();
   } else {
     return ParsePostfixExpression(ok);
   }
 }
 
 
 PreParser::Expression PreParser::ParsePostfixExpression(bool* ok) {
   // PostfixExpression ::
   //   LeftHandSideExpression ('++' | '--')?
 
-  ScannerBase::Location before = scanner()->peek_location();
+  Scanner::Location before = scanner()->peek_location();
   Expression expression = ParseLeftHandSideExpression(CHECK_OK);
   if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
       Token::IsCountOp(peek())) {
-    if (!is_classic_mode() &&
+    if (!scope_->is_classic_mode() &&
         expression.IsIdentifier() &&
         expression.AsIdentifier().IsEvalOrArguments()) {
-      ScannerBase::Location after = scanner()->location();
-      ReportMessageAt(before.beg_pos, after.end_pos,
-                      "strict_lhs_postfix", NULL);
+      Scanner::Location after = scanner()->location();
+      PreParserTraits::ReportMessageAt(before.beg_pos, after.end_pos,
+                                       "strict_eval_arguments", NULL);
       *ok = false;
       return Expression::Default();
     }
     Next();
     return Expression::Default();
   }
   return expression;
 }
 
 
 PreParser::Expression PreParser::ParseLeftHandSideExpression(bool* ok) {
   // LeftHandSideExpression ::
   //   (NewExpression | MemberExpression) ...
 
-  Expression result = Expression::Default();
-  if (peek() == Token::NEW) {
-    result = ParseNewExpression(CHECK_OK);
-  } else {
-    result = ParseMemberExpression(CHECK_OK);
-  }
+  Expression result = ParseMemberWithNewPrefixesExpression(CHECK_OK);
 
   while (true) {
     switch (peek()) {
       case Token::LBRACK: {
         Consume(Token::LBRACK);
         ParseExpression(true, CHECK_OK);
         Expect(Token::RBRACK, CHECK_OK);
         if (result.IsThis()) {
           result = Expression::ThisProperty();
         } else {
@@ skipping 19 matching lines @@
         break;
       }
 
       default:
         return result;
     }
   }
 }
 
 
-PreParser::Expression PreParser::ParseNewExpression(bool* ok) {
+PreParser::Expression PreParser::ParseMemberWithNewPrefixesExpression(
+    bool* ok) {
   // NewExpression ::
   //   ('new')+ MemberExpression
 
-  // The grammar for new expressions is pretty warped. The keyword
-  // 'new' can either be a part of the new expression (where it isn't
-  // followed by an argument list) or a part of the member expression,
-  // where it must be followed by an argument list. To accommodate
-  // this, we parse the 'new' keywords greedily and keep track of how
-  // many we have parsed. This information is then passed on to the
-  // member expression parser, which is only allowed to match argument
-  // lists as long as it has 'new' prefixes left
-  unsigned new_count = 0;
-  do {
+  // See Parser::ParseNewExpression.
+
+  if (peek() == Token::NEW) {
     Consume(Token::NEW);
-    new_count++;
-  } while (peek() == Token::NEW);
-
-  return ParseMemberWithNewPrefixesExpression(new_count, ok);
+    ParseMemberWithNewPrefixesExpression(CHECK_OK);
+    if (peek() == Token::LPAREN) {
+      // NewExpression with arguments.
+      ParseArguments(CHECK_OK);
+      // The expression can still continue with . or [ after the arguments.
+      ParseMemberExpressionContinuation(Expression::Default(), CHECK_OK);
+    }
+    return Expression::Default();
+  }
+  // No 'new' keyword.
+  return ParseMemberExpression(ok);
 }
 
 
 PreParser::Expression PreParser::ParseMemberExpression(bool* ok) {
-  return ParseMemberWithNewPrefixesExpression(0, ok);
-}
-
-
-PreParser::Expression PreParser::ParseMemberWithNewPrefixesExpression(
-    unsigned new_count, bool* ok) {
   // MemberExpression ::
   //   (PrimaryExpression | FunctionLiteral)
   //     ('[' 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);
 
     bool is_generator = allow_generators() && Check(Token::MUL);
-    Identifier identifier = Identifier::Default();
+    Identifier name = Identifier::Default();
+    bool is_strict_reserved_name = false;
+    Scanner::Location function_name_location = Scanner::Location::invalid();
     if (peek_any_identifier()) {
-      identifier = ParseIdentifier(CHECK_OK);
+      name = ParseIdentifierOrStrictReservedWord(&is_strict_reserved_name,
+                                                 CHECK_OK);
+      function_name_location = scanner()->location();
     }
-    result = ParseFunctionLiteral(is_generator, CHECK_OK);
-    if (result.IsStrictFunction() && !identifier.IsValidStrictVariable()) {
-      StrictModeIdentifierViolation(scanner()->location(),
-                                    "strict_function_name",
-                                    identifier,
-                                    ok);
-      return Expression::Default();
-    }
+    result = ParseFunctionLiteral(name,
+                                  function_name_location,
+                                  is_strict_reserved_name,
+                                  is_generator,
+                                  CHECK_OK);
   } else {
     result = ParsePrimaryExpression(CHECK_OK);
   }
+  result = ParseMemberExpressionContinuation(result, CHECK_OK);
+  return result;
+}
 
+
+PreParser::Expression PreParser::ParseMemberExpressionContinuation(
+    PreParserExpression expression, bool* ok) {
+  // Parses this part of MemberExpression:
+  // ('[' Expression ']' | '.' Identifier)*
   while (true) {
     switch (peek()) {
       case Token::LBRACK: {
         Consume(Token::LBRACK);
         ParseExpression(true, CHECK_OK);
         Expect(Token::RBRACK, CHECK_OK);
-        if (result.IsThis()) {
-          result = Expression::ThisProperty();
+        if (expression.IsThis()) {
+          expression = Expression::ThisProperty();
         } else {
-          result = Expression::Default();
+          expression = Expression::Default();
         }
         break;
       }
       case Token::PERIOD: {
         Consume(Token::PERIOD);
         ParseIdentifierName(CHECK_OK);
-        if (result.IsThis()) {
-          result = Expression::ThisProperty();
+        if (expression.IsThis()) {
+          expression = Expression::ThisProperty();
         } else {
-          result = Expression::Default();
+          expression = Expression::Default();
         }
         break;
       }
-      case Token::LPAREN: {
-        if (new_count == 0) return result;
-        // Consume one of the new prefixes (already parsed).
-        ParseArguments(CHECK_OK);
-        new_count--;
-        result = Expression::Default();
-        break;
-      }
       default:
-        return result;
+        return expression;
     }
   }
+  ASSERT(false);
+  return PreParserExpression::Default();
 }
 
 
-PreParser::Expression PreParser::ParsePrimaryExpression(bool* ok) {
-  // PrimaryExpression ::
-  //   'this'
-  //   'null'
-  //   'true'
-  //   'false'
-  //   Identifier
-  //   Number
-  //   String
-  //   ArrayLiteral
-  //   ObjectLiteral
-  //   RegExpLiteral
-  //   '(' Expression ')'
-
-  Expression result = Expression::Default();
-  switch (peek()) {
-    case Token::THIS: {
-      Next();
-      result = Expression::This();
-      break;
-    }
-
-    case Token::FUTURE_RESERVED_WORD:
-    case Token::FUTURE_STRICT_RESERVED_WORD:
-    case Token::YIELD:
-    case Token::IDENTIFIER: {
-      Identifier id = ParseIdentifier(CHECK_OK);
-      result = Expression::FromIdentifier(id);
-      break;
-    }
-
-    case Token::NULL_LITERAL:
-    case Token::TRUE_LITERAL:
-    case Token::FALSE_LITERAL:
-    case Token::NUMBER: {
-      Next();
-      break;
-    }
-    case Token::STRING: {
-      Next();
-      result = GetStringSymbol();
-      break;
-    }
-
-    case Token::ASSIGN_DIV:
-      result = ParseRegExpLiteral(true, CHECK_OK);
-      break;
-
-    case Token::DIV:
-      result = ParseRegExpLiteral(false, CHECK_OK);
-      break;
-
-    case Token::LBRACK:
-      result = ParseArrayLiteral(CHECK_OK);
-      break;
-
-    case Token::LBRACE:
-      result = ParseObjectLiteral(CHECK_OK);
-      break;
-
-    case Token::LPAREN:
-      Consume(Token::LPAREN);
-      parenthesized_function_ = (peek() == Token::FUNCTION);
-      result = ParseExpression(true, CHECK_OK);
-      Expect(Token::RPAREN, CHECK_OK);
-      result = result.Parenthesize();
-      break;
-
-    case Token::MOD:
-      result = ParseV8Intrinsic(CHECK_OK);
-      break;
-
-    default: {
-      Next();
-      *ok = false;
-      return Expression::Default();
-    }
-  }
-
-  return result;
-}
-
-
-PreParser::Expression PreParser::ParseArrayLiteral(bool* ok) {
-  // ArrayLiteral ::
-  //   '[' Expression? (',' Expression?)* ']'
-  Expect(Token::LBRACK, CHECK_OK);
-  while (peek() != Token::RBRACK) {
-    if (peek() != Token::COMMA) {
-      ParseAssignmentExpression(true, CHECK_OK);
-    }
-    if (peek() != Token::RBRACK) {
-      Expect(Token::COMMA, CHECK_OK);
-    }
-  }
-  Expect(Token::RBRACK, CHECK_OK);
-
-  scope_->NextMaterializedLiteralIndex();
-  return Expression::Default();
-}
-
-
 PreParser::Expression PreParser::ParseObjectLiteral(bool* ok) {
   // ObjectLiteral ::
   //   '{' (
   //       ((IdentifierName | String | Number) ':' AssignmentExpression)
   //     | (('get' | 'set') (IdentifierName | String | Number) FunctionLiteral)
   //    )*[','] '}'
 
-  ObjectLiteralChecker checker(this, language_mode());
+  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(false, 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);
-        GetStringSymbol();
+        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);
 
-  scope_->NextMaterializedLiteralIndex();
+  function_state_->NextMaterializedLiteralIndex();
   return Expression::Default();
 }
 
-
-PreParser::Expression PreParser::ParseRegExpLiteral(bool seen_equal,
-                                                    bool* ok) {
-  if (!scanner()->ScanRegExpPattern(seen_equal)) {
-    Next();
-    ReportMessageAt(scanner()->location(), "unterminated_regexp", NULL);
-    *ok = false;
-    return Expression::Default();
-  }
-
-  scope_->NextMaterializedLiteralIndex();
-
-  if (!scanner()->ScanRegExpFlags()) {
-    Next();
-    ReportMessageAt(scanner()->location(), "invalid_regexp_flags", NULL);
-    *ok = false;
-    return Expression::Default();
-  }
-  Next();
-  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(bool is_generator,
-                                                      bool* ok) {
+PreParser::Expression PreParser::ParseFunctionLiteral(
+    Identifier function_name,
+    Scanner::Location function_name_location,
+    bool name_is_strict_reserved,
+    bool is_generator,
+    bool* ok) {
   // Function ::
   //   '(' FormalParameterList? ')' '{' FunctionBody '}'
 
   // Parse function body.
   ScopeType outer_scope_type = scope_->type();
-  bool inside_with = scope_->IsInsideWith();
-  Scope function_scope(&scope_, kFunctionScope);
-  function_scope.set_is_generator(is_generator);
+  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);
   //  FormalParameterList ::
   //    '(' (Identifier)*[','] ')'
   Expect(Token::LPAREN, CHECK_OK);
   int start_position = position();
   bool done = (peek() == Token::RPAREN);
   DuplicateFinder duplicate_finder(scanner()->unicode_cache());
+  // We don't yet know if the function will be strict, so we cannot yet produce
+  // errors for parameter names or duplicates. However, we remember the
+  // locations of these errors if they occur and produce the errors later.
+  Scanner::Location eval_args_error_loc = Scanner::Location::invalid();
+  Scanner::Location dupe_error_loc = Scanner::Location::invalid();
+  Scanner::Location reserved_error_loc = Scanner::Location::invalid();
   while (!done) {
-    Identifier id = ParseIdentifier(CHECK_OK);
-    if (!id.IsValidStrictVariable()) {
-      StrictModeIdentifierViolation(scanner()->location(),
-                                    "strict_param_name",
-                                    id,
-                                    CHECK_OK);
+    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);
     }
 
-    if (prev_value != 0) {
-      SetStrictModeViolation(scanner()->location(),
-                             "strict_param_dupe",
-                             CHECK_OK);
+    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);
 
-  // Determine if the function will be lazily compiled.
-  // Currently only happens to top-level functions.
-  // Optimistically assume that all top-level functions are lazily compiled.
-  bool is_lazily_compiled = (outer_scope_type == kTopLevelScope &&
-                             !inside_with && allow_lazy() &&
-                             !parenthesized_function_);
+  // 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_compiled) {
+  if (is_lazily_parsed) {
     ParseLazyFunctionLiteralBody(CHECK_OK);
   } else {
     ParseSourceElements(Token::RBRACE, ok);
   }
   Expect(Token::RBRACE, CHECK_OK);
 
-  if (!is_classic_mode()) {
+  // 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 (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();
+    }
+    if (eval_args_error_loc.IsValid()) {
+      ReportMessageAt(eval_args_error_loc, "strict_eval_arguments");
+      *ok = false;
+      return Expression::Default();
+    }
+    if (dupe_error_loc.IsValid()) {
+      ReportMessageAt(dupe_error_loc, "strict_param_dupe");
+      *ok = false;
+      return Expression::Default();
+    }
+    if (reserved_error_loc.IsValid()) {
+      ReportMessageAt(reserved_error_loc, "unexpected_strict_reserved");
+      *ok = false;
+      return Expression::Default();
+    }
+
     int end_position = scanner()->location().end_pos;
     CheckOctalLiteral(start_position, end_position, CHECK_OK);
-    CheckDelayedStrictModeViolation(start_position, end_position, CHECK_OK);
     return Expression::StrictFunction();
   }
 
   return Expression::Default();
 }
 
 
 void PreParser::ParseLazyFunctionLiteralBody(bool* ok) {
   int body_start = position();
   log_->PauseRecording();
   ParseSourceElements(Token::RBRACE, ok);
   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,
-                    scope_->materialized_literal_count(),
-                    scope_->expected_properties(),
-                    language_mode());
+                    function_state_->materialized_literal_count(),
+                    function_state_->expected_property_count(),
+                    scope_->language_mode());
 }
 
 
 PreParser::Expression PreParser::ParseV8Intrinsic(bool* ok) {
   // CallRuntime ::
   //   '%' Identifier Arguments
   Expect(Token::MOD, CHECK_OK);
   if (!allow_natives_syntax()) {
     *ok = false;
     return Expression::Default();
   }
-  ParseIdentifier(CHECK_OK);
+  // 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());
   }
 }
 
 
-PreParser::Expression PreParser::GetStringSymbol() {
-  const int kUseStrictLength = 10;
-  const char* kUseStrictChars = "use strict";
-  LogSymbol();
-  if (scanner()->is_literal_ascii() &&
-      scanner()->literal_length() == kUseStrictLength &&
-      !scanner()->literal_contains_escapes() &&
-      !strncmp(scanner()->literal_ascii_string().start(), kUseStrictChars,
-               kUseStrictLength)) {
-    return Expression::UseStrictStringLiteral();
-  }
-  return Expression::StringLiteral();
-}
-
-
-PreParser::Identifier PreParser::GetIdentifierSymbol() {
-  LogSymbol();
-  if (scanner()->current_token() == Token::FUTURE_RESERVED_WORD) {
-    return Identifier::FutureReserved();
-  } else if (scanner()->current_token() ==
-             Token::FUTURE_STRICT_RESERVED_WORD) {
-    return Identifier::FutureStrictReserved();
-  } else if (scanner()->current_token() == Token::YIELD) {
-    return Identifier::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 Identifier::Eval();
-    }
-    if (scanner()->literal_length() == 9 &&
-        !strncmp(scanner()->literal_ascii_string().start(), "arguments", 9)) {
-      return Identifier::Arguments();
-    }
-  }
-  return Identifier::Default();
-}
-
-
-PreParser::Identifier PreParser::ParseIdentifier(bool* ok) {
-  Token::Value next = Next();
-  switch (next) {
-    case Token::FUTURE_RESERVED_WORD: {
-      ScannerBase::Location location = scanner()->location();
-      ReportMessageAt(location.beg_pos, location.end_pos,
-                      "reserved_word", NULL);
-      *ok = false;
-      return GetIdentifierSymbol();
-    }
-    case Token::YIELD:
-      if (scope_->is_generator()) {
-        // 'yield' in a generator is only valid as part of a YieldExpression.
-        ReportMessageAt(scanner()->location(), "unexpected_token", "yield");
-        *ok = false;
-        return Identifier::Yield();
-      }
-      // FALLTHROUGH
-    case Token::FUTURE_STRICT_RESERVED_WORD:
-      if (!is_classic_mode()) {
-        ScannerBase::Location location = scanner()->location();
-        ReportMessageAt(location.beg_pos, location.end_pos,
-                        "strict_reserved_word", NULL);
-        *ok = false;
-      }
-      // FALLTHROUGH
-    case Token::IDENTIFIER:
-      return GetIdentifierSymbol();
-    default:
-      *ok = false;
-      return Identifier::Default();
-  }
-}
-
-
-void PreParser::SetStrictModeViolation(ScannerBase::Location location,
-                                       const char* type,
-                                       bool* ok) {
-  if (!is_classic_mode()) {
-    ReportMessageAt(location, type, NULL);
-    *ok = false;
-    return;
-  }
-  // Delay report in case this later turns out to be strict code
-  // (i.e., for function names and parameters prior to a "use strict"
-  // directive).
-  // It's safe to overwrite an existing violation.
-  // It's either from a function that turned out to be non-strict,
-  // or it's in the current function (and we just need to report
-  // one error), or it's in a unclosed nesting function that wasn't
-  // strict (otherwise we would already be in strict mode).
-  strict_mode_violation_location_ = location;
-  strict_mode_violation_type_ = type;
-}
-
-
-void PreParser::CheckDelayedStrictModeViolation(int beg_pos,
-                                                int end_pos,
-                                                bool* ok) {
-  ScannerBase::Location location = strict_mode_violation_location_;
-  if (location.IsValid() &&
-      location.beg_pos > beg_pos && location.end_pos < end_pos) {
-    ReportMessageAt(location, strict_mode_violation_type_, NULL);
-    *ok = false;
-  }
-}
-
-
-void PreParser::StrictModeIdentifierViolation(ScannerBase::Location location,
-                                              const char* eval_args_type,
-                                              Identifier identifier,
-                                              bool* ok) {
-  const char* type = eval_args_type;
-  if (identifier.IsFutureReserved()) {
-    type = "reserved_word";
-  } else if (identifier.IsFutureStrictReserved() || identifier.IsYield()) {
-    type = "strict_reserved_word";
-  }
-  if (!is_classic_mode()) {
-    ReportMessageAt(location, type, NULL);
-    *ok = false;
-    return;
-  }
-  strict_mode_violation_location_ = location;
-  strict_mode_violation_type_ = type;
-}
-
-
-PreParser::Identifier PreParser::ParseIdentifierName(bool* ok) {
-  Token::Value next = Next();
-  if (Token::IsKeyword(next)) {
-    int pos = position();
-    const char* keyword = Token::String(next);
-    log_->LogAsciiSymbol(pos, Vector<const char>(keyword, StrLength(keyword)));
-    return Identifier::Default();
-  }
-  if (next == Token::IDENTIFIER ||
-      next == Token::FUTURE_RESERVED_WORD ||
-      next == Token::FUTURE_STRICT_RESERVED_WORD) {
-    return GetIdentifierSymbol();
-  }
-  *ok = false;
-  return Identifier::Default();
-}
-
-#undef CHECK_OK
-
-
-// This function reads an identifier and determines whether or not it
-// is 'get' or 'set'.
-PreParser::Identifier PreParser::ParseIdentifierNameOrGetOrSet(bool* is_get,
-                                                               bool* is_set,
-                                                               bool* ok) {
-  Identifier result = ParseIdentifierName(ok);
-  if (!*ok) return Identifier::Default();
-  if (scanner()->is_literal_ascii() &&
-      scanner()->literal_length() == 3) {
-    const char* token = scanner()->literal_ascii_string().start();
-    *is_get = strncmp(token, "get", 3) == 0;
-    *is_set = !*is_get && strncmp(token, "set", 3) == 0;
-  }
-  return result;
-}
-
-
-void PreParser::ObjectLiteralChecker::CheckProperty(Token::Value property,
-                                                    PropertyKind type,
-                                                    bool* ok) {
-  int old;
-  if (property == Token::NUMBER) {
-    old = finder_.AddNumber(scanner()->literal_ascii_string(), type);
-  } else if (scanner()->is_literal_ascii()) {
-    old = finder_.AddAsciiSymbol(scanner()->literal_ascii_string(), type);
-  } else {
-    old = finder_.AddUtf16Symbol(scanner()->literal_utf16_string(), type);
-  }
-  PropertyKind old_type = static_cast<PropertyKind>(old);
-  if (HasConflict(old_type, type)) {
-    if (IsDataDataConflict(old_type, type)) {
-      // Both are data properties.
-      if (language_mode_ == CLASSIC_MODE) return;
-      parser()->ReportMessageAt(scanner()->location(),
-                               "strict_duplicate_property");
-    } else if (IsDataAccessorConflict(old_type, type)) {
-      // Both a data and an accessor property with the same name.
-      parser()->ReportMessageAt(scanner()->location(),
-                               "accessor_data_property");
-    } else {
-      ASSERT(IsAccessorAccessorConflict(old_type, type));
-      // Both accessors of the same type.
-      parser()->ReportMessageAt(scanner()->location(),
-                               "accessor_get_set");
-    }
-    *ok = false;
-  }
-}
-
 } }  // v8::internal