[strong] Remove all remainders of strong mode

src/parsing/parser-base.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PARSING_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
 #include "src/hashmap.h"
@@ skipping 97 matching lines @@
         stack_overflow_(false),
         allow_lazy_(false),
         allow_natives_(false),
         allow_harmony_sloppy_(false),
         allow_harmony_sloppy_function_(false),
         allow_harmony_sloppy_let_(false),
         allow_harmony_default_parameters_(false),
         allow_harmony_destructuring_bind_(false),
         allow_harmony_destructuring_assignment_(false),
         allow_harmony_restrictive_declarations_(false),
-        allow_strong_mode_(false),
         allow_legacy_const_(true),
         allow_harmony_do_expressions_(false),
         allow_harmony_function_name_(false),
         allow_harmony_function_sent_(false) {}
 
 #define ALLOW_ACCESSORS(name)                           \
   bool allow_##name() const { return allow_##name##_; } \
   void set_allow_##name(bool allow) { allow_##name##_ = allow; }
 
   ALLOW_ACCESSORS(lazy);
   ALLOW_ACCESSORS(natives);
   ALLOW_ACCESSORS(harmony_sloppy);
   ALLOW_ACCESSORS(harmony_sloppy_function);
   ALLOW_ACCESSORS(harmony_sloppy_let);
   ALLOW_ACCESSORS(harmony_default_parameters);
   ALLOW_ACCESSORS(harmony_destructuring_bind);
   ALLOW_ACCESSORS(harmony_destructuring_assignment);
   ALLOW_ACCESSORS(harmony_restrictive_declarations);
-  ALLOW_ACCESSORS(strong_mode);
   ALLOW_ACCESSORS(legacy_const);
   ALLOW_ACCESSORS(harmony_do_expressions);
   ALLOW_ACCESSORS(harmony_function_name);
   ALLOW_ACCESSORS(harmony_function_sent);
 #undef ALLOW_ACCESSORS
 
   uintptr_t stack_limit() const { return stack_limit_; }
 
  protected:
   enum AllowRestrictedIdentifiers {
@@ skipping 328 matching lines @@
     Expect(Token::IDENTIFIER, ok);
     if (!*ok) return;
     if (!scanner()->is_literal_contextual_keyword(keyword)) {
       ReportUnexpectedToken(scanner()->current_token());
       *ok = false;
     }
   }
 
   bool CheckInOrOf(ForEachStatement::VisitMode* visit_mode, bool* ok) {
     if (Check(Token::IN)) {
-      if (is_strong(language_mode())) {
-        ReportMessageAt(scanner()->location(), MessageTemplate::kStrongForIn);
-        *ok = false;
-      } else {
-        *visit_mode = ForEachStatement::ENUMERATE;
-      }
+      *visit_mode = ForEachStatement::ENUMERATE;
       return true;
     } else if (CheckContextualKeyword(CStrVector("of"))) {
       *visit_mode = ForEachStatement::ITERATE;
       return true;
     }
     return false;
   }
 
   bool PeekInOrOf() {
     return peek() == Token::IN || PeekContextualKeyword(CStrVector("of"));
@@ skipping 40 matching lines @@
                               MessageTemplate::kStrictEvalArguments);
       *ok = false;
       return;
     }
     if (function_name_validity == kFunctionNameIsStrictReserved) {
       Traits::ReportMessageAt(function_name_loc,
                               MessageTemplate::kUnexpectedStrictReserved);
       *ok = false;
       return;
     }
-    if (is_strong(language_mode) && this->IsUndefined(function_name)) {
-      Traits::ReportMessageAt(function_name_loc,
-                              MessageTemplate::kStrongUndefined);
-      *ok = false;
-      return;
-    }
   }
 
   // Determine precedence of given token.
   static int Precedence(Token::Value token, bool accept_IN) {
     if (token == Token::IN && !accept_IN)
       return 0;  // 0 precedence will terminate binary expression parsing
     return Token::Precedence(token);
   }
 
   typename Traits::Type::Factory* factory() {
@@ skipping 84 matching lines @@
                                 LanguageMode language_mode,
                                 bool allow_duplicates, bool* ok) {
     if (!allow_duplicates &&
         !classifier->is_valid_formal_parameter_list_without_duplicates()) {
       ReportClassifierError(classifier->duplicate_formal_parameter_error());
       *ok = false;
     } else if (is_strict(language_mode) &&
                !classifier->is_valid_strict_mode_formal_parameters()) {
       ReportClassifierError(classifier->strict_mode_formal_parameter_error());
       *ok = false;
-    } else if (is_strong(language_mode) &&
-               !classifier->is_valid_strong_mode_formal_parameters()) {
-      ReportClassifierError(classifier->strong_mode_formal_parameter_error());
-      *ok = false;
     }
   }
 
   void ValidateArrowFormalParameters(const ExpressionClassifier* classifier,
                                      ExpressionT expr,
                                      bool parenthesized_formals, bool* ok) {
     if (classifier->is_valid_binding_pattern()) {
       // A simple arrow formal parameter: IDENTIFIER => BODY.
       if (!this->IsIdentifier(expr)) {
         Traits::ReportMessageAt(scanner()->location(),
@@ skipping 123 matching lines @@
   ExpressionT ParseArrowFunctionLiteral(bool accept_IN,
                                         const FormalParametersT& parameters,
                                         const ExpressionClassifier& classifier,
                                         bool* ok);
   ExpressionT ParseTemplateLiteral(ExpressionT tag, int start,
                                    ExpressionClassifier* classifier, bool* ok);
   void AddTemplateExpression(ExpressionT);
   ExpressionT ParseSuperExpression(bool is_new,
                                    ExpressionClassifier* classifier, bool* ok);
   ExpressionT ParseNewTargetExpression(bool* ok);
-  ExpressionT ParseStrongInitializationExpression(
-      ExpressionClassifier* classifier, bool* ok);
-  ExpressionT ParseStrongSuperCallExpression(ExpressionClassifier* classifier,
-                                             bool* ok);
 
   void ParseFormalParameter(FormalParametersT* parameters,
                             ExpressionClassifier* classifier, bool* ok);
   void ParseFormalParameterList(FormalParametersT* parameters,
                                 ExpressionClassifier* classifier, bool* ok);
   void CheckArityRestrictions(int param_count, FunctionKind function_type,
                               bool has_rest, int formals_start_pos,
                               int formals_end_pos, bool* ok);
 
   bool IsNextLetKeyword();
@@ skipping 13 matching lines @@
       MessageTemplate::Template message, ParseErrorType type, bool* ok);
 
   bool IsValidReferenceExpression(ExpressionT expression);
 
   bool IsAssignableIdentifier(ExpressionT expression) {
     if (!Traits::IsIdentifier(expression)) return false;
     if (is_strict(language_mode()) &&
         Traits::IsEvalOrArguments(Traits::AsIdentifier(expression))) {
       return false;
     }
-    if (is_strong(language_mode()) &&
-        Traits::IsUndefined(Traits::AsIdentifier(expression))) {
-      return false;
-    }
     return true;
   }
 
   bool IsValidPattern(ExpressionT expression) {
     return expression->IsObjectLiteral() || expression->IsArrayLiteral();
   }
 
   // Keep track of eval() calls since they disable all local variable
   // optimizations. This checks if expression is an eval call, and if yes,
   // forwards the information to scope.
@@ skipping 87 matching lines @@
 
   bool allow_lazy_;
   bool allow_natives_;
   bool allow_harmony_sloppy_;
   bool allow_harmony_sloppy_function_;
   bool allow_harmony_sloppy_let_;
   bool allow_harmony_default_parameters_;
   bool allow_harmony_destructuring_bind_;
   bool allow_harmony_destructuring_assignment_;
   bool allow_harmony_restrictive_declarations_;
-  bool allow_strong_mode_;
   bool allow_legacy_const_;
   bool allow_harmony_do_expressions_;
   bool allow_harmony_function_name_;
   bool allow_harmony_function_sent_;
 };
 
 template <class Traits>
 ParserBase<Traits>::FunctionState::FunctionState(
     FunctionState** function_state_stack, Scope** scope_stack, Scope* scope,
     FunctionKind kind, typename Traits::Type::Factory* factory)
@@ skipping 129 matching lines @@
       }
     }
     if (this->IsArguments(name)) {
       scope_->RecordArgumentsUsage();
       classifier->RecordStrictModeFormalParameterError(
           scanner()->location(), MessageTemplate::kStrictEvalArguments);
       if (is_strict(language_mode())) {
         classifier->RecordBindingPatternError(
             scanner()->location(), MessageTemplate::kStrictEvalArguments);
       }
-      if (is_strong(language_mode())) {
-        classifier->RecordExpressionError(scanner()->location(),
-                                          MessageTemplate::kStrongArguments);
-      }
-    }
-    if (this->IsUndefined(name)) {
-      classifier->RecordStrongModeFormalParameterError(
-          scanner()->location(), MessageTemplate::kStrongUndefined);
-      if (is_strong(language_mode())) {
-        // TODO(dslomov): allow 'undefined' in nested patterns.
-        classifier->RecordPatternError(scanner()->location(),
-                                       MessageTemplate::kStrongUndefined);
-      }
     }
 
     if (classifier->duplicate_finder() != nullptr &&
         scanner()->FindSymbol(classifier->duplicate_finder(), 1) != 0) {
       classifier->RecordDuplicateFormalParameterError(scanner()->location());
     }
     return name;
   } else if (is_sloppy(language_mode()) &&
              (next == Token::FUTURE_STRICT_RESERVED_WORD ||
               next == Token::ESCAPED_STRICT_RESERVED_WORD ||
@@ skipping 123 matching lines @@
   //   ClassLiteral
   //   '(' Expression ')'
   //   TemplateLiteral
   //   do Block
 
   int beg_pos = peek_position();
   switch (peek()) {
     case Token::THIS: {
       BindingPatternUnexpectedToken(classifier);
       Consume(Token::THIS);
-      if (FLAG_strong_this && is_strong(language_mode())) {
-        // Constructors' usages of 'this' in strong mode are parsed separately.
-        // TODO(rossberg): this does not work with arrow functions yet.
-        if (IsClassConstructor(function_state_->kind())) {
-          ReportMessage(MessageTemplate::kStrongConstructorThis);
-          *ok = false;
-          return this->EmptyExpression();
-        }
-      }
       return this->ThisExpression(scope_, factory(), beg_pos);
     }
 
     case Token::NULL_LITERAL:
     case Token::TRUE_LITERAL:
     case Token::FALSE_LITERAL:
       BindingPatternUnexpectedToken(classifier);
       return this->ExpressionFromLiteral(Next(), beg_pos, scanner(), factory());
     case Token::SMI:
     case Token::NUMBER:
@@ skipping 219 matching lines @@
   //   '[' Expression? (',' Expression?)* ']'
 
   int pos = peek_position();
   typename Traits::Type::ExpressionList values =
       this->NewExpressionList(4, zone_);
   int first_spread_index = -1;
   Expect(Token::LBRACK, CHECK_OK);
   while (peek() != Token::RBRACK) {
     ExpressionT elem = this->EmptyExpression();
     if (peek() == Token::COMMA) {
-      if (is_strong(language_mode())) {
-        ReportMessageAt(scanner()->peek_location(),
-                        MessageTemplate::kStrongEllision);
-        *ok = false;
-        return this->EmptyExpression();
-      }
       elem = this->GetLiteralTheHole(peek_position(), factory());
     } else if (peek() == Token::ELLIPSIS) {
       int start_pos = peek_position();
       Consume(Token::ELLIPSIS);
       int expr_pos = peek_position();
       ExpressionT argument =
           this->ParseAssignmentExpression(true, classifier, CHECK_OK);
       elem = factory()->NewSpread(argument, start_pos, expr_pos);
 
       if (first_spread_index < 0) {
@@ skipping 678 matching lines @@
                                           bool* ok) {
   DCHECK(prec >= 4);
   ExpressionT x = this->ParseUnaryExpression(classifier, CHECK_OK);
   for (int prec1 = Precedence(peek(), accept_IN); prec1 >= prec; prec1--) {
     // prec1 >= 4
     while (Precedence(peek(), accept_IN) == prec1) {
       Traits::RewriteNonPattern(classifier, CHECK_OK);
       BindingPatternUnexpectedToken(classifier);
       ArrowFormalParametersUnexpectedToken(classifier);
       Token::Value op = Next();
-      Scanner::Location op_location = scanner()->location();
       int pos = position();
       ExpressionT y =
           ParseBinaryExpression(prec1 + 1, accept_IN, classifier, CHECK_OK);
       Traits::RewriteNonPattern(classifier, CHECK_OK);
 
       if (this->ShortcutNumericLiteralBinaryExpression(&x, y, op, pos,
                                                        factory())) {
         continue;
       }
 
       // For now we distinguish between comparisons and other binary
       // operations.  (We could combine the two and get rid of this
       // code and AST node eventually.)
       if (Token::IsCompareOp(op)) {
         // We have a comparison.
         Token::Value cmp = op;
         switch (op) {
           case Token::NE: cmp = Token::EQ; break;
           case Token::NE_STRICT: cmp = Token::EQ_STRICT; break;
           default: break;
         }
-        if (cmp == Token::EQ && is_strong(language_mode())) {
-          ReportMessageAt(op_location, MessageTemplate::kStrongEqual);
-          *ok = false;
-          return this->EmptyExpression();
-        } else if (FLAG_harmony_instanceof && cmp == Token::INSTANCEOF) {
+        if (FLAG_harmony_instanceof && cmp == Token::INSTANCEOF) {
           x = Traits::RewriteInstanceof(x, y, pos);
         } else {
           x = factory()->NewCompareOperation(cmp, x, y, pos);
           if (cmp != op) {
             // The comparison was negated - add a NOT.
             x = factory()->NewUnaryOperation(Token::NOT, x, pos);
           }
         }
       } else {
         // We have a "normal" binary operation.
@@ skipping 25 matching lines @@
   if (Token::IsUnaryOp(op)) {
     BindingPatternUnexpectedToken(classifier);
     ArrowFormalParametersUnexpectedToken(classifier);
 
     op = Next();
     int pos = position();
     ExpressionT expression = ParseUnaryExpression(classifier, CHECK_OK);
     Traits::RewriteNonPattern(classifier, CHECK_OK);
 
     if (op == Token::DELETE && is_strict(language_mode())) {
-      if (is_strong(language_mode())) {
-        ReportMessage(MessageTemplate::kStrongDelete);
-        *ok = false;
-        return this->EmptyExpression();
-      } else if (this->IsIdentifier(expression)) {
+      if (this->IsIdentifier(expression)) {
         // "delete identifier" is a syntax error in strict mode.
         ReportMessage(MessageTemplate::kStrictDelete);
         *ok = false;
         return this->EmptyExpression();
       }
     }
 
     // Allow Traits do rewrite the expression.
     return this->BuildUnaryExpression(expression, op, pos, factory());
   } else if (Token::IsCountOp(op)) {
@@ skipping 74 matching lines @@
         result = factory()->NewProperty(result, index, pos);
         Expect(Token::RBRACK, CHECK_OK);
         break;
       }
 
       case Token::LPAREN: {
         Traits::RewriteNonPattern(classifier, CHECK_OK);
         BindingPatternUnexpectedToken(classifier);
         ArrowFormalParametersUnexpectedToken(classifier);
 
-        if (is_strong(language_mode()) && this->IsIdentifier(result) &&
-            this->IsEval(this->AsIdentifier(result))) {
-          ReportMessage(MessageTemplate::kStrongDirectEval);
-          *ok = false;
-          return this->EmptyExpression();
-        }
         int pos;
         if (scanner()->current_token() == Token::IDENTIFIER ||
             scanner()->current_token() == Token::SUPER) {
           // For call of an identifier we want to report position of
           // the identifier as position of the call in the stack trace.
           pos = position();
         } else {
           // For other kinds of calls we record position of the parenthesis as
           // position of the call. Note that this is extremely important for
           // expressions of the form function(){...}() for which call position
@@ skipping 197 matching lines @@
     result = ParsePrimaryExpression(classifier, CHECK_OK);
   }
 
   result = ParseMemberExpressionContinuation(result, classifier, CHECK_OK);
   return result;
 }
 
 
 template <class Traits>
 typename ParserBase<Traits>::ExpressionT
-ParserBase<Traits>::ParseStrongInitializationExpression(
-    ExpressionClassifier* classifier, bool* ok) {
-  // InitializationExpression ::  (strong mode)
-  //  'this' '.' IdentifierName '=' AssignmentExpression
-  //  'this' '[' Expression ']' '=' AssignmentExpression
-
-  FuncNameInferrer::State fni_state(fni_);
-
-  Consume(Token::THIS);
-  int pos = position();
-  function_state_->set_this_location(scanner()->location());
-  ExpressionT this_expr = this->ThisExpression(scope_, factory(), pos);
-
-  ExpressionT left = this->EmptyExpression();
-  switch (peek()) {
-    case Token::LBRACK: {
-      Consume(Token::LBRACK);
-      int pos = position();
-      ExpressionT index = this->ParseExpression(true, classifier, CHECK_OK);
-      Traits::RewriteNonPattern(classifier, CHECK_OK);
-      left = factory()->NewProperty(this_expr, index, pos);
-      if (fni_ != NULL) {
-        this->PushPropertyName(fni_, index);
-      }
-      Expect(Token::RBRACK, CHECK_OK);
-      break;
-    }
-    case Token::PERIOD: {
-      Consume(Token::PERIOD);
-      int pos = position();
-      IdentifierT name = ParseIdentifierName(CHECK_OK);
-      left = factory()->NewProperty(
-          this_expr, factory()->NewStringLiteral(name, pos), pos);
-      if (fni_ != NULL) {
-        this->PushLiteralName(fni_, name);
-      }
-      break;
-    }
-    default:
-      ReportMessage(MessageTemplate::kStrongConstructorThis);
-      *ok = false;
-      return this->EmptyExpression();
-  }
-
-  if (peek() != Token::ASSIGN) {
-    ReportMessageAt(function_state_->this_location(),
-                    MessageTemplate::kStrongConstructorThis);
-    *ok = false;
-    return this->EmptyExpression();
-  }
-  Consume(Token::ASSIGN);
-  left = this->MarkExpressionAsAssigned(left);
-
-  ExpressionT right =
-      this->ParseAssignmentExpression(true, classifier, CHECK_OK);
-  Traits::RewriteNonPattern(classifier, CHECK_OK);
-  this->CheckAssigningFunctionLiteralToProperty(left, right);
-  function_state_->AddProperty();
-  if (fni_ != NULL) {
-    // Check if the right hand side is a call to avoid inferring a
-    // name if we're dealing with "this.a = function(){...}();"-like
-    // expression.
-    if (!right->IsCall() && !right->IsCallNew()) {
-      fni_->Infer();
-    } else {
-      fni_->RemoveLastFunction();
-    }
-  }
-
-  if (function_state_->return_location().IsValid()) {
-    ReportMessageAt(function_state_->return_location(),
-                    MessageTemplate::kStrongConstructorReturnMisplaced);
-    *ok = false;
-    return this->EmptyExpression();
-  }
-
-  return factory()->NewAssignment(Token::ASSIGN, left, right, pos);
-}
-
-
-template <class Traits>
-typename ParserBase<Traits>::ExpressionT
-ParserBase<Traits>::ParseStrongSuperCallExpression(
-    ExpressionClassifier* classifier, bool* ok) {
-  // SuperCallExpression ::  (strong mode)
-  //  'super' '(' ExpressionList ')'
-  BindingPatternUnexpectedToken(classifier);
-
-  Consume(Token::SUPER);
-  int pos = position();
-  Scanner::Location super_loc = scanner()->location();
-  ExpressionT expr = this->SuperCallReference(scope_, factory(), pos);
-
-  if (peek() != Token::LPAREN) {
-    ReportMessage(MessageTemplate::kStrongConstructorSuper);
-    *ok = false;
-    return this->EmptyExpression();
-  }
-
-  Scanner::Location spread_pos;
-  typename Traits::Type::ExpressionList args =
-      ParseArguments(&spread_pos, classifier, CHECK_OK);
-
-  // TODO(rossberg): This doesn't work with arrow functions yet.
-  if (!IsSubclassConstructor(function_state_->kind())) {
-    ReportMessage(MessageTemplate::kUnexpectedSuper);
-    *ok = false;
-    return this->EmptyExpression();
-  } else if (function_state_->super_location().IsValid()) {
-    ReportMessageAt(scanner()->location(),
-                    MessageTemplate::kStrongSuperCallDuplicate);
-    *ok = false;
-    return this->EmptyExpression();
-  } else if (function_state_->this_location().IsValid()) {
-    ReportMessageAt(scanner()->location(),
-                    MessageTemplate::kStrongSuperCallMisplaced);
-    *ok = false;
-    return this->EmptyExpression();
-  } else if (function_state_->return_location().IsValid()) {
-    ReportMessageAt(function_state_->return_location(),
-                    MessageTemplate::kStrongConstructorReturnMisplaced);
-    *ok = false;
-    return this->EmptyExpression();
-  }
-
-  function_state_->set_super_location(super_loc);
-  if (spread_pos.IsValid()) {
-    args = Traits::PrepareSpreadArguments(args);
-    expr = Traits::SpreadCall(expr, args, pos);
-  } else {
-    expr = factory()->NewCall(expr, args, pos);
-  }
-
-  // Explicit calls to the super constructor using super() perform an implicit
-  // binding assignment to the 'this' variable.
-  ExpressionT this_expr = this->ThisExpression(scope_, factory(), pos);
-  return factory()->NewAssignment(Token::INIT, this_expr, expr, pos);
-}
-
-
-template <class Traits>
-typename ParserBase<Traits>::ExpressionT
 ParserBase<Traits>::ParseSuperExpression(bool is_new,
                                          ExpressionClassifier* classifier,
                                          bool* ok) {
   Expect(Token::SUPER, CHECK_OK);
   int pos = position();
 
   Scope* scope = scope_->ReceiverScope();
   FunctionKind kind = scope->function_kind();
   if (IsConciseMethod(kind) || IsAccessorFunction(kind) ||
       IsClassConstructor(kind)) {
     if (peek() == Token::PERIOD || peek() == Token::LBRACK) {
       scope->RecordSuperPropertyUsage();
       return this->SuperPropertyReference(scope_, factory(), pos);
     }
     // new super() is never allowed.
     // super() is only allowed in derived constructor
     if (!is_new && peek() == Token::LPAREN && IsSubclassConstructor(kind)) {
-      if (is_strong(language_mode())) {
-        // Super calls in strong mode are parsed separately.
-        ReportMessageAt(scanner()->location(),
-                        MessageTemplate::kStrongConstructorSuper);
-        *ok = false;
-        return this->EmptyExpression();
-      }
       // TODO(rossberg): This might not be the correct FunctionState for the
       // method here.
       function_state_->set_super_location(scanner()->location());
       return this->SuperCallReference(scope_, factory(), pos);
     }
   }
 
   ReportMessageAt(scanner()->location(), MessageTemplate::kUnexpectedSuper);
   *ok = false;
   return this->EmptyExpression();
@@ skipping 480 matching lines @@
     ExpressionClassifier* classifier, ExpressionT expression, int beg_pos,
     int end_pos, MessageTemplate::Template message, ParseErrorType type) {
   Scanner::Location location(beg_pos, end_pos);
   if (this->IsIdentifier(expression)) {
     if (is_strict(language_mode()) &&
         this->IsEvalOrArguments(this->AsIdentifier(expression))) {
       classifier->RecordExpressionError(
           location, MessageTemplate::kStrictEvalArguments, kSyntaxError);
       return expression;
     }
-    if (is_strong(language_mode()) &&
-        this->IsUndefined(this->AsIdentifier(expression))) {
-      classifier->RecordExpressionError(
-          location, MessageTemplate::kStrongUndefined, kSyntaxError);
-      return expression;
-    }
   }
   if (expression->IsValidReferenceExpression()) {
     return expression;
   } else if (expression->IsCall()) {
     // If it is a call, make it a runtime error for legacy web compatibility.
     // Rewrite `expr' to `expr[throw ReferenceError]'.
     int pos = location.beg_pos;
     ExpressionT error = this->NewThrowReferenceError(message, pos);
     return factory()->NewProperty(expression, error, pos);
   } else {
@@ skipping 78 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H