Proper handling of future reserved words in strict and normal mode.

BUG=86442
TEST=mjsunit/keywords-and-reserved_words.js

Review URL: http://codereview.chromium.org/7207007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8421 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/messages.js

@@ -148,6 +148,7 @@ function FormatMessage(message) {
       unexpected_token_number:      ["Unexpected number"],
       unexpected_token_string:      ["Unexpected string"],
       unexpected_token_identifier:  ["Unexpected identifier"],
+      unexpected_reserved:          ["Unexpected reserved word"],
       unexpected_strict_reserved:   ["Unexpected strict mode reserved word"],
       unexpected_eos:               ["Unexpected end of input"],
       malformed_regexp:             ["Invalid regular expression: /", "%0", "/: ", "%1"],

src/parser.cc

@@ -1445,10 +1445,11 @@ Statement* Parser::ParseFunctionDeclaration(bool* ok) {
   //   'function' Identifier '(' FormalParameterListopt ')' '{' FunctionBody '}'
   Expect(Token::FUNCTION, CHECK_OK);
   int function_token_position = scanner().location().beg_pos;
-  bool is_reserved = false;
-  Handle<String> name = ParseIdentifierOrReservedWord(&is_reserved, CHECK_OK);
+  bool is_strict_reserved = false;
+  Handle<String> name = ParseIdentifierOrStrictReservedWord(
+      &is_strict_reserved, CHECK_OK);
   FunctionLiteral* fun = ParseFunctionLiteral(name,
-                                              is_reserved,
+                                              is_strict_reserved,
                                               function_token_position,
                                               DECLARATION,
                                               CHECK_OK);
@@ -2774,11 +2775,12 @@ Expression* Parser::ParseMemberWithNewPrefixesExpression(PositionStack* stack,
     Expect(Token::FUNCTION, CHECK_OK);
     int function_token_position = scanner().location().beg_pos;
     Handle<String> name;
-    bool is_reserved_name = false;
+    bool is_strict_reserved_name = false;
     if (peek_any_identifier()) {
-        name = ParseIdentifierOrReservedWord(&is_reserved_name, CHECK_OK);
+      name = ParseIdentifierOrStrictReservedWord(&is_strict_reserved_name,
+                                                 CHECK_OK);
     }
-    result = ParseFunctionLiteral(name, is_reserved_name,
+    result = ParseFunctionLiteral(name, is_strict_reserved_name,
                                   function_token_position, NESTED, CHECK_OK);
   } else {
     result = ParsePrimaryExpression(CHECK_OK);
@@ -2857,6 +2859,9 @@ void Parser::ReportUnexpectedToken(Token::Value token) {
       return ReportMessage("unexpected_token_identifier",
                            Vector<const char*>::empty());
     case Token::FUTURE_RESERVED_WORD:
+      return ReportMessage("unexpected_reserved",
+                           Vector<const char*>::empty());
+    case Token::FUTURE_STRICT_RESERVED_WORD:
       return ReportMessage(top_scope_->is_strict_mode() ?
                                "unexpected_strict_reserved" :
                                "unexpected_token_identifier",
@@ -2917,7 +2922,7 @@ Expression* Parser::ParsePrimaryExpression(bool* ok) {
       break;
 
     case Token::IDENTIFIER:
-    case Token::FUTURE_RESERVED_WORD: {
+    case Token::FUTURE_STRICT_RESERVED_WORD: {
       Handle<String> name = ParseIdentifier(CHECK_OK);
       if (fni_ != NULL) fni_->PushVariableName(name);
       result = top_scope_->NewUnresolved(name,
@@ -3328,6 +3333,7 @@ ObjectLiteral::Property* Parser::ParseObjectLiteralGetSet(bool is_getter,
   bool is_keyword = Token::IsKeyword(next);
   if (next == Token::IDENTIFIER || next == Token::NUMBER ||
       next == Token::FUTURE_RESERVED_WORD ||
+      next == Token::FUTURE_STRICT_RESERVED_WORD ||
       next == Token::STRING || is_keyword) {
     Handle<String> name;
     if (is_keyword) {
@@ -3382,11 +3388,12 @@ Expression* Parser::ParseObjectLiteral(bool* ok) {
 
     switch (next) {
       case Token::FUTURE_RESERVED_WORD:
+      case Token::FUTURE_STRICT_RESERVED_WORD:
       case Token::IDENTIFIER: {
         bool is_getter = false;
         bool is_setter = false;
         Handle<String> id =
-            ParseIdentifierOrGetOrSet(&is_getter, &is_setter, CHECK_OK);
+            ParseIdentifierNameOrGetOrSet(&is_getter, &is_setter, CHECK_OK);
         if (fni_ != NULL) fni_->PushLiteralName(id);
 
         if ((is_getter || is_setter) && peek() != Token::COLON) {
@@ -3545,7 +3552,7 @@ ZoneList<Expression*>* Parser::ParseArguments(bool* ok) {
 
 
 FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
-                                              bool name_is_reserved,
+                                              bool name_is_strict_reserved,
                                               int function_token_position,
                                               FunctionLiteralType type,
                                               bool* ok) {
@@ -3589,9 +3596,10 @@ FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
 
     bool done = (peek() == Token::RPAREN);
     while (!done) {
-      bool is_reserved = false;
+      bool is_strict_reserved = false;
       Handle<String> param_name =
-          ParseIdentifierOrReservedWord(&is_reserved, CHECK_OK);
+          ParseIdentifierOrStrictReservedWord(&is_strict_reserved,
+                                              CHECK_OK);
 
       // Store locations for possible future error reports.
       if (!name_loc.IsValid() && IsEvalOrArguments(param_name)) {
@@ -3601,7 +3609,7 @@ FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
         has_duplicate_parameters = true;
         dupe_loc = scanner().location();
       }
-      if (!reserved_loc.IsValid() && is_reserved) {
+      if (!reserved_loc.IsValid() && is_strict_reserved) {
         reserved_loc = scanner().location();
       }
 
@@ -3703,7 +3711,7 @@ FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
         *ok = false;
         return NULL;
       }
-      if (name_is_reserved) {
+      if (name_is_strict_reserved) {
         int position = function_token_position != RelocInfo::kNoPosition
             ? function_token_position
             : (start_pos > 0 ? start_pos - 1 : start_pos);
@@ -3792,7 +3800,8 @@ Expression* Parser::ParseV8Intrinsic(bool* ok) {
 bool Parser::peek_any_identifier() {
   Token::Value next = peek();
   return next == Token::IDENTIFIER ||
-         next == Token::FUTURE_RESERVED_WORD;
+         next == Token::FUTURE_RESERVED_WORD ||
+         next == Token::FUTURE_STRICT_RESERVED_WORD;
 }
 
 
@@ -3854,22 +3863,27 @@ Literal* Parser::GetLiteralNumber(double value) {
 }
 
 
+// Parses and identifier that is valid for the current scope, in particular it
+// fails on strict mode future reserved keywords in a strict scope.
 Handle<String> Parser::ParseIdentifier(bool* ok) {
-  bool is_reserved;
-  return ParseIdentifierOrReservedWord(&is_reserved, ok);
+  if (top_scope_->is_strict_mode()) {
+    Expect(Token::IDENTIFIER, ok);
+  } else if (!Check(Token::IDENTIFIER)) {
+    Expect(Token::FUTURE_STRICT_RESERVED_WORD, ok);
+  }
+  if (!*ok) return Handle<String>();
+  return GetSymbol(ok);
 }
 
 
-Handle<String> Parser::ParseIdentifierOrReservedWord(bool* is_reserved,
-                                                     bool* ok) {
-  *is_reserved = false;
-  if (top_scope_->is_strict_mode()) {
-    Expect(Token::IDENTIFIER, ok);
-  } else {
-    if (!Check(Token::IDENTIFIER)) {
-      Expect(Token::FUTURE_RESERVED_WORD, ok);
-      *is_reserved = true;
-    }
+// Parses and identifier or a strict mode future reserved word, and indicate
+// whether it is strict mode future reserved.
+Handle<String> Parser::ParseIdentifierOrStrictReservedWord(
+    bool* is_strict_reserved, bool* ok) {
+  *is_strict_reserved = false;
+  if (!Check(Token::IDENTIFIER)) {
+    Expect(Token::FUTURE_STRICT_RESERVED_WORD, ok);
+    *is_strict_reserved = true;
   }
   if (!*ok) return Handle<String>();
   return GetSymbol(ok);
@@ -3879,8 +3893,9 @@ Handle<String> Parser::ParseIdentifierOrReservedWord(bool* is_reserved,
 Handle<String> Parser::ParseIdentifierName(bool* ok) {
   Token::Value next = Next();
   if (next != Token::IDENTIFIER &&
-          next != Token::FUTURE_RESERVED_WORD &&
-          !Token::IsKeyword(next)) {
+      next != Token::FUTURE_RESERVED_WORD &&
+      next != Token::FUTURE_STRICT_RESERVED_WORD &&
+      !Token::IsKeyword(next)) {
     ReportUnexpectedToken(next);
     *ok = false;
     return Handle<String>();
@@ -3921,12 +3936,12 @@ void Parser::CheckOctalLiteral(int beg_pos, int end_pos, bool* ok) {
 }
 
 
-// This function reads an identifier and determines whether or not it
+// This function reads an identifier name and determines whether or not it
 // is 'get' or 'set'.
-Handle<String> Parser::ParseIdentifierOrGetOrSet(bool* is_get,
-                                                 bool* is_set,
-                                                 bool* ok) {
-  Handle<String> result = ParseIdentifier(ok);
+Handle<String> Parser::ParseIdentifierNameOrGetOrSet(bool* is_get,
+                                                     bool* is_set,
+                                                     bool* ok) {
+  Handle<String> result = ParseIdentifierName(ok);
   if (!*ok) return Handle<String>();
   if (scanner().is_literal_ascii() && scanner().literal_length() == 3) {
     const char* token = scanner().literal_ascii_string().start();

src/parser.h

@@ -623,11 +623,12 @@ class Parser {
   Literal* GetLiteralNumber(double value);
 
   Handle<String> ParseIdentifier(bool* ok);
-  Handle<String> ParseIdentifierOrReservedWord(bool* is_reserved, bool* ok);
+  Handle<String> ParseIdentifierOrStrictReservedWord(
+      bool* is_strict_reserved, bool* ok);
   Handle<String> ParseIdentifierName(bool* ok);
-  Handle<String> ParseIdentifierOrGetOrSet(bool* is_get,
-                                           bool* is_set,
-                                           bool* ok);
+  Handle<String> ParseIdentifierNameOrGetOrSet(bool* is_get,
+                                               bool* is_set,
+                                               bool* ok);
 
   // Strict mode validation of LValue expressions
   void CheckStrictModeLValue(Expression* expression,

src/preparser.cc

@@ -77,9 +77,14 @@ void PreParser::ReportUnexpectedToken(i::Token::Value token) {
     return ReportMessageAt(source_location.beg_pos, source_location.end_pos,
                            "unexpected_token_string", NULL);
   case i::Token::IDENTIFIER:
-  case i::Token::FUTURE_RESERVED_WORD:
     return ReportMessageAt(source_location.beg_pos, source_location.end_pos,
                            "unexpected_token_identifier", NULL);
+  case i::Token::FUTURE_RESERVED_WORD:
+    return ReportMessageAt(source_location.beg_pos, source_location.end_pos,
+                           "unexpected_reserved", NULL);
+  case i::Token::FUTURE_STRICT_RESERVED_WORD:
+    return ReportMessageAt(source_location.beg_pos, source_location.end_pos,
+                           "unexpected_strict_reserved", NULL);
   default:
     const char* name = i::Token::String(token);
     ReportMessageAt(source_location.beg_pos, source_location.end_pos,
@@ -233,7 +238,7 @@ PreParser::Statement PreParser::ParseFunctionDeclaration(bool* ok) {
     // Strict mode violation, using either reserved word or eval/arguments
     // as name of strict function.
     const char* type = "strict_function_name";
-    if (identifier.IsFutureReserved()) {
+    if (identifier.IsFutureStrictReserved()) {
       type = "strict_reserved_word";
     }
     ReportMessageAt(location.beg_pos, location.end_pos, type, NULL);
@@ -979,7 +984,16 @@ PreParser::Expression PreParser::ParsePrimaryExpression(bool* ok) {
       break;
     }
 
-    case i::Token::FUTURE_RESERVED_WORD:
+    case i::Token::FUTURE_RESERVED_WORD: {
+      Next();
+      i::Scanner::Location location = scanner_->location();
+      ReportMessageAt(location.beg_pos, location.end_pos,
+                      "reserved_word", NULL);
+      *ok = false;
+      return Expression::Default();
+    }
+
+    case i::Token::FUTURE_STRICT_RESERVED_WORD:
       if (strict_mode()) {
         Next();
         i::Scanner::Location location = scanner_->location();
@@ -1078,15 +1092,17 @@ PreParser::Expression PreParser::ParseObjectLiteral(bool* ok) {
     i::Token::Value next = peek();
     switch (next) {
       case i::Token::IDENTIFIER:
-      case i::Token::FUTURE_RESERVED_WORD: {
+      case i::Token::FUTURE_RESERVED_WORD:
+      case i::Token::FUTURE_STRICT_RESERVED_WORD: {
         bool is_getter = false;
         bool is_setter = false;
-        ParseIdentifierOrGetOrSet(&is_getter, &is_setter, CHECK_OK);
+        ParseIdentifierNameOrGetOrSet(&is_getter, &is_setter, CHECK_OK);
         if ((is_getter || is_setter) && peek() != i::Token::COLON) {
             i::Token::Value name = Next();
             bool is_keyword = i::Token::IsKeyword(name);
             if (name != i::Token::IDENTIFIER &&
                 name != i::Token::FUTURE_RESERVED_WORD &&
+                name != i::Token::FUTURE_STRICT_RESERVED_WORD &&
                 name != i::Token::NUMBER &&
                 name != i::Token::STRING &&
                 !is_keyword) {
@@ -1312,6 +1328,9 @@ PreParser::Identifier PreParser::GetIdentifierSymbol() {
   LogSymbol();
   if (scanner_->current_token() == i::Token::FUTURE_RESERVED_WORD) {
     return Identifier::FutureReserved();
+  } else if (scanner_->current_token() ==
+             i::Token::FUTURE_STRICT_RESERVED_WORD) {
+    return Identifier::FutureStrictReserved();
   }
   if (scanner_->is_literal_ascii()) {
     // Detect strict-mode poison words.
@@ -1329,11 +1348,22 @@ PreParser::Identifier PreParser::GetIdentifierSymbol() {
 
 
 PreParser::Identifier PreParser::ParseIdentifier(bool* ok) {
-  if (!Check(i::Token::FUTURE_RESERVED_WORD)) {
-    Expect(i::Token::IDENTIFIER, ok);
-    if (!*ok) return Identifier::Default();
+  i::Token::Value next = Next();
+  switch (next) {
+    case i::Token::FUTURE_RESERVED_WORD: {
+      i::Scanner::Location location = scanner_->location();
+      ReportMessageAt(location.beg_pos, location.end_pos,
+                      "reserved_word", NULL);
+      *ok = false;
+    }
+      // FALLTHROUGH
+    case i::Token::FUTURE_STRICT_RESERVED_WORD:
+    case i::Token::IDENTIFIER:
+      return GetIdentifierSymbol();
+    default:
+      *ok = false;
+      return Identifier::Default();
   }
-  return GetIdentifierSymbol();
 }
 
 
@@ -1373,6 +1403,8 @@ void PreParser::StrictModeIdentifierViolation(i::Scanner::Location location,
                                               bool* ok) {
   const char* type = eval_args_type;
   if (identifier.IsFutureReserved()) {
+    type = "reserved_word";
+  } else if (identifier.IsFutureStrictReserved()) {
     type = "strict_reserved_word";
   }
   if (strict_mode()) {
@@ -1395,7 +1427,8 @@ PreParser::Identifier PreParser::ParseIdentifierName(bool* ok) {
     return Identifier::Default();
   }
   if (next == i::Token::IDENTIFIER ||
-      next == i::Token::FUTURE_RESERVED_WORD) {
+      next == i::Token::FUTURE_RESERVED_WORD ||
+      next == i::Token::FUTURE_STRICT_RESERVED_WORD) {
     return GetIdentifierSymbol();
   }
   *ok = false;
@@ -1407,10 +1440,10 @@ PreParser::Identifier PreParser::ParseIdentifierName(bool* ok) {
 
 // This function reads an identifier and determines whether or not it
 // is 'get' or 'set'.
-PreParser::Identifier PreParser::ParseIdentifierOrGetOrSet(bool* is_get,
-                                                           bool* is_set,
-                                                           bool* ok) {
-  Identifier result = ParseIdentifier(ok);
+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) {
@@ -1424,6 +1457,7 @@ PreParser::Identifier PreParser::ParseIdentifierOrGetOrSet(bool* is_get,
 bool PreParser::peek_any_identifier() {
   i::Token::Value next = peek();
   return next == i::Token::IDENTIFIER ||
-         next == i::Token::FUTURE_RESERVED_WORD;
+         next == i::Token::FUTURE_RESERVED_WORD ||
+         next == i::Token::FUTURE_STRICT_RESERVED_WORD;
 }
 } }  // v8::preparser

src/preparser.h

@@ -93,16 +93,23 @@ class PreParser {
     static Identifier FutureReserved()  {
       return Identifier(kFutureReservedIdentifier);
     }
+    static Identifier FutureStrictReserved()  {
+      return Identifier(kFutureStrictReservedIdentifier);
+    }
     bool IsEval() { return type_ == kEvalIdentifier; }
     bool IsArguments() { return type_ == kArgumentsIdentifier; }
     bool IsEvalOrArguments() { return type_ >= kEvalIdentifier; }
     bool IsFutureReserved() { return type_ == kFutureReservedIdentifier; }
+    bool IsFutureStrictReserved() {
+      return type_ == kFutureStrictReservedIdentifier;
+    }
     bool IsValidStrictVariable() { return type_ == kUnknownIdentifier; }
 
    private:
     enum Type {
       kUnknownIdentifier,
       kFutureReservedIdentifier,
+      kFutureStrictReservedIdentifier,
       kEvalIdentifier,
       kArgumentsIdentifier
     };
@@ -411,7 +418,9 @@ class PreParser {
 
   Identifier ParseIdentifier(bool* ok);
   Identifier ParseIdentifierName(bool* ok);
-  Identifier ParseIdentifierOrGetOrSet(bool* is_get, bool* is_set, bool* ok);
+  Identifier ParseIdentifierNameOrGetOrSet(bool* is_get,
+                                           bool* is_set,
+                                           bool* ok);
 
   // Logs the currently parsed literal as a symbol in the preparser data.
   void LogSymbol();

src/scanner-base.cc

@@ -799,7 +799,7 @@ KeywordMatcher::FirstState KeywordMatcher::first_states_[] = {
   { NULL,     I,              Token::ILLEGAL },
   { NULL,     UNMATCHABLE,    Token::ILLEGAL },
   { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { "let",    KEYWORD_PREFIX, Token::FUTURE_RESERVED_WORD },
+  { "let",    KEYWORD_PREFIX, Token::FUTURE_STRICT_RESERVED_WORD },
   { NULL,     UNMATCHABLE,    Token::ILLEGAL },
   { NULL,     N,              Token::ILLEGAL },
   { NULL,     UNMATCHABLE,    Token::ILLEGAL },
@@ -812,7 +812,7 @@ KeywordMatcher::FirstState KeywordMatcher::first_states_[] = {
   { NULL,     V,              Token::ILLEGAL },
   { NULL,     W,              Token::ILLEGAL },
   { NULL,     UNMATCHABLE,    Token::ILLEGAL },
-  { "yield",  KEYWORD_PREFIX, Token::FUTURE_RESERVED_WORD }
+  { "yield",  KEYWORD_PREFIX, Token::FUTURE_STRICT_RESERVED_WORD }
 };
 
 
@@ -849,7 +849,7 @@ void KeywordMatcher::Step(unibrow::uchar input) {
     case C:
       if (MatchState(input, 'a', CA)) return;
       if (MatchKeywordStart(input, "class", 1,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_RESERVED_WORD)) return;
       if (MatchState(input, 'o', CO)) return;
       break;
     case CA:
@@ -875,14 +875,14 @@ void KeywordMatcher::Step(unibrow::uchar input) {
     case E:
       if (MatchKeywordStart(input, "else", 1, Token::ELSE)) return;
       if (MatchKeywordStart(input, "enum", 1,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_RESERVED_WORD)) return;
       if (MatchState(input, 'x', EX)) return;
       break;
     case EX:
       if (MatchKeywordStart(input, "export", 2,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_RESERVED_WORD)) return;
       if (MatchKeywordStart(input, "extends", 2,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_RESERVED_WORD)) return;
       break;
     case F:
       if (MatchKeywordStart(input, "false", 1, Token::FALSE_LITERAL)) return;
@@ -900,14 +900,14 @@ void KeywordMatcher::Step(unibrow::uchar input) {
       break;
     case IMP:
       if (MatchKeywordStart(input, "implements", 3,
-         Token::FUTURE_RESERVED_WORD )) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD )) return;
       if (MatchKeywordStart(input, "import", 3,
-         Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_RESERVED_WORD)) return;
       break;
     case IN:
       token_ = Token::IDENTIFIER;
       if (MatchKeywordStart(input, "interface", 2,
-         Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD)) return;
       if (MatchKeywordStart(input, "instanceof", 2, Token::INSTANCEOF)) return;
       break;
     case N:
@@ -916,24 +916,24 @@ void KeywordMatcher::Step(unibrow::uchar input) {
       break;
     case P:
       if (MatchKeywordStart(input, "package", 1,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD)) return;
       if (MatchState(input, 'r', PR)) return;
       if (MatchKeywordStart(input, "public", 1,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD)) return;
       break;
     case PR:
       if (MatchKeywordStart(input, "private", 2,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD)) return;
       if (MatchKeywordStart(input, "protected", 2,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD)) return;
       break;
     case S:
       if (MatchKeywordStart(input, "static", 1,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_STRICT_RESERVED_WORD)) return;
       if (MatchKeywordStart(input, "super", 1,
-          Token::FUTURE_RESERVED_WORD)) return;
+                            Token::FUTURE_RESERVED_WORD)) return;
       if (MatchKeywordStart(input, "switch", 1,
-          Token::SWITCH)) return;
+                            Token::SWITCH)) return;
       break;
     case T:
       if (MatchState(input, 'h', TH)) return;

src/scanner-base.h

@@ -549,14 +549,20 @@ class JavaScriptScanner : public Scanner {
 class KeywordMatcher {
 //  Incrementally recognize keywords.
 //
+//  We distinguish between normal future reserved words and words that are
+//  considered to be future reserved words only in strict mode as required by
+//  ECMA-262 7.6.1.2.
+//
 //  Recognized as keywords:
 //      break, case, catch, const*, continue, debugger, default, delete, do,
 //      else, finally, false, for, function, if, in, instanceof, new, null,
 //      return, switch, this, throw, true, try, typeof, var, void, while, with.
 //
-//  Recognized as Future Reserved Keywords (normal and strict mode):
-//      class, enum, export, extends, implements, import, interface,
-//      let, package, private, private, protected, public, public,
+//  Recognized as Future Reserved Keywords:
+//      class, enum, export, extends, import, super.
+//
+//  Recognized as Future Reserved Keywords (strict mode only):
+//      implements, interface, let, package, private, protected, public,
 //      static, yield.
 //
 //  *: Actually a "future reserved keyword". It's the only one we are

src/token.h

@@ -167,6 +167,7 @@ namespace internal {
                                                                         \
   /* Future reserved words (ECMA-262, section 7.6.1.2). */              \
   T(FUTURE_RESERVED_WORD, NULL, 0)                                      \
+  T(FUTURE_STRICT_RESERVED_WORD, NULL, 0)                               \
   K(CONST, "const", 0)                                                  \
                                                                         \
   /* Illegal token - not able to scan. */                               \

test/mjsunit/keywords-and-reserved_words.js

+// 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test proper handling of keywords, future reserved words and
+// future reserved words in strict mode as specific by 7.6.1 and 7.6.2
+// in ECMA-262.
+
+// This code is based on:
+// http://trac.webkit.org/export/89109/trunk/LayoutTests/fast/js/script-tests/keywords-and-reserved_words.js
+
+function isKeyword(x)
+{
+  try {
+    eval("var " + x + ";");
+  } catch(e) {
+    return true;
+  }
+
+  return false;
+}
+
+function isStrictKeyword(x)
+{
+  try {
+    eval("'use strict'; var "+x+";");
+  } catch(e) {
+    return true;
+  }
+
+  return false;
+}
+
+function classifyIdentifier(x)
+{
+  if (isKeyword(x)) {
+    // All non-strict keywords are also keywords in strict code.
+    if (!isStrictKeyword(x)) {
+      return "ERROR";
+    }
+    return "keyword";
+  }
+
+  // Check for strict mode future reserved words.
+  if (isStrictKeyword(x)) {
+    return "strict";
+  }
+
+  return "identifier";
+}
+
+function testKeyword(word) {
+  // Classify word
+  assertEquals("keyword", classifyIdentifier(word));
+
+  // Simple use of a keyword
+  assertThrows("var " + word + " = 1;", SyntaxError);
+  if (word != "this") {
+    assertThrows("typeof (" + word + ");", SyntaxError);
+  }
+
+  // object literal properties
+  eval("var x = { " + word + " : 42 };");
+  eval("var x = { get " + word + " () {} };");
+  eval("var x = { set " + word + " (value) {} };");
+
+  // object literal with string literal property names
+  eval("var x = { '" + word + "' : 42 };");
+  eval("var x = { get '" + word + "' () { } };");
+  eval("var x = { set '" + word + "' (value) { } };");
+
+  // Function names and arguments
+  assertThrows("function " + word + " () { }", SyntaxError);
+  assertThrows("function foo (" + word + ") {}", SyntaxError);
+  assertThrows("function foo (a, " + word + ") { }", SyntaxError);
+  assertThrows("function foo (" + word + ", a) { }", SyntaxError);
+  assertThrows("function foo (a, " + word + ", b) { }", SyntaxError);
+  assertThrows("var foo = function (" + word + ") { }", SyntaxError);
+
+  // setter parameter
+  assertThrows("var x = { set foo(" + word + ") { } };", SyntaxError);
+}
+
+// Not keywords - these are all just identifiers.
+var identifiers = [
+  "x",            "keyword",
+  "id",           "strict",
+  "identifier",   "use",
+  // The following are reserved in ES3 but not in ES5.
+  "abstract",     "int",
+  "boolean",      "long",
+  "byte",         "native",
+  "char",         "short",
+  "double",       "synchronized",
+  "final",        "throws",
+  "float",        "transient",
+  "goto",         "volatile" ];
+
+for (var i = 0; i < identifiers.length; i++) {
+  assertEquals ("identifier", classifyIdentifier(identifiers[i]));
+}
+
+// 7.6.1.1 Keywords
+var keywords = [
+  "break",        "in",
+  "case",         "instanceof",
+  "catch",        "new",
+  "continue",     "return",
+  "debugger",     "switch",
+  "default",      "this",
+  "delete",       "throw",
+  "do",           "try",
+  "else",         "typeof",
+  "finally",      "var",
+  "for",          "void",
+  "function",     "while",
+  "if",           "with",
+  // In ES5 "const" is a "future reserved word" but we treat it as a keyword.
+  "const" ];
+
+for (var i = 0; i < keywords.length; i++) {
+  testKeyword(keywords[i]);
+}
+
+// 7.6.1.2 Future Reserved Words (without "const")
+var future_reserved_words = [
+  "class",
+  "enum",
+  "export",
+  "extends",
+  "import",
+  "super" ];
+
+for (var i = 0; i < future_reserved_words.length; i++) {
+  testKeyword(future_reserved_words[i]);
+}
+
+// 7.6.1.2 Future Reserved Words, in strict mode only.
+var future_strict_reserved_words = [
+  "implements",
+  "interface",
+  "let",
+  "package",
+  "private",
+  "protected",
+  "public",
+  "static",
+  "yield" ];
+
+for (var i = 0; i < future_strict_reserved_words.length; i++) {
+  assertEquals ("strict", classifyIdentifier(future_strict_reserved_words[i]));
+}
+
+// More strict mode specific tests can be found in mjsunit/strict-mode.js.

test/mjsunit/strict-mode.js

@@ -67,6 +67,9 @@ function CheckFunctionConstructorStrictMode() {
   with ({}) {};
 })();
 
+// Incorrectly place 'use strict' directive.
+assertThrows("function foo (x) 'use strict'; {}", SyntaxError);
+
 // 'use strict' in non-directive position.
 (function UseStrictNonDirective() {
   void(0);
@@ -319,14 +322,8 @@ CheckStrictMode("var variable; delete variable;", SyntaxError);
            +arguments, -arguments, ~arguments, !arguments];
 })();
 
-// 7.6.1.2 Future Reserved Words
-var future_reserved_words = [
-  "class",
-  "enum",
-  "export",
-  "extends",
-  "import",
-  "super",
+// 7.6.1.2 Future Reserved Words in strict mode
+var future_strict_reserved_words = [
   "implements",
   "interface",
   "let",
@@ -337,14 +334,17 @@ var future_reserved_words = [
   "static",
   "yield" ];
 
-function testFutureReservedWord(word) {
+function testFutureStrictReservedWord(word) {
   // Simple use of each reserved word
   CheckStrictMode("var " + word + " = 1;", SyntaxError);
+  CheckStrictMode("typeof (" + word + ");", SyntaxError);
 
   // object literal properties
   eval("var x = { " + word + " : 42 };");
   eval("var x = { get " + word + " () {} };");
   eval("var x = { set " + word + " (value) {} };");
+  eval("var x = { get " + word + " () { 'use strict'; } };");
+  eval("var x = { set " + word + " (value) { 'use strict'; } };");
 
   // object literal with string literal property names
   eval("var x = { '" + word + "' : 42 };");
@@ -364,7 +364,6 @@ function testFutureReservedWord(word) {
 
   // Function names and arguments when the body is strict
   assertThrows("function " + word + " () { 'use strict'; }", SyntaxError);
-  assertThrows("function foo (" + word + ")  'use strict'; {}", SyntaxError);
   assertThrows("function foo (" + word + ", " + word + ") { 'use strict'; }",
                SyntaxError);
   assertThrows("function foo (a, " + word + ") { 'use strict'; }", SyntaxError);
@@ -374,17 +373,14 @@ function testFutureReservedWord(word) {
   assertThrows("var foo = function (" + word + ") { 'use strict'; }",
                SyntaxError);
 
-  // get/set when the body is strict
-  eval("var x = { get " + word + " () { 'use strict'; } };");
-  eval("var x = { set " + word + " (value) { 'use strict'; } };");
-  assertThrows("var x = { get foo(" + word + ") { 'use strict'; } };",
-               SyntaxError);
+  // setter parameter when the body is strict
+  CheckStrictMode("var x = { set foo(" + word + ") {} };", SyntaxError);
   assertThrows("var x = { set foo(" + word + ") { 'use strict'; } };",
                SyntaxError);
 }
 
-for (var i = 0; i < future_reserved_words.length; i++) {
-  testFutureReservedWord(future_reserved_words[i]);
+for (var i = 0; i < future_strict_reserved_words.length; i++) {
+  testFutureStrictReservedWord(future_strict_reserved_words[i]);
 }
 
 function testAssignToUndefined(test, should_throw) {

test/preparser/strict-identifiers.pyt

@@ -164,6 +164,20 @@ non_strict_use = Template("nonstrict-$id", """
   x = {get $id() {}, set $id(value) {}};
 """)
 
+identifier_name_source = """
+  var x = {$id: 42};
+  x = {get $id() {}, set $id(value) {}};
+  x.$id = 42;
+  function foo() { "use strict;" }
+  x = {$id: 42};
+  x = {get $id() {}, set $id(value) {}};
+  x.$id = 42;
+"""
+
+identifier_name = Template("identifier_name-$id", identifier_name_source)
+identifier_name_strict = StrictTemplate("identifier_name_strict-$id",
+                                        identifier_name_source)
+
 # ----------------------------------------------------------------------
 # Run tests
 
@@ -189,8 +203,12 @@ for id in ["eval", "arguments"]:
 # Reserved words just throw the same exception in all cases
 # (with "const" being special, as usual).
 for reserved_word in reserved_words + strict_reserved_words:
-  message = "strict_reserved_word"
-  if (reserved_word == "const"): message = "unexpected_token"
+  if (reserved_word in strict_reserved_words):
+    message = "strict_reserved_word"
+  elif (reserved_word == "const"):
+    message = "unexpected_token"
+  else:
+    message = "reserved_word"
   arg_name_own({"id":reserved_word}, message)
   arg_name_nested({"id":reserved_word}, message)
   setter_arg({"id": reserved_word}, message)
@@ -205,5 +223,11 @@ for reserved_word in reserved_words + strict_reserved_words:
   postfix_var({"id":reserved_word, "op":"++", "opname":"inc"}, message)
   postfix_var({"id":reserved_word, "op":"--", "opname":"dec"}, message)
   read_var({"id": reserved_word}, message)
+  identifier_name({"id": reserved_word}, None);
+  identifier_name_strict({"id": reserved_word}, None);
 
 
+# Future reserved words in strict mode behave like normal identifiers
+# in a non strict context.
+for reserved_word in strict_reserved_words:
+  non_strict_use({"id": id}, None)