Strict mode eval/arguments LHS.

src/parser.cc

 // Copyright 2010 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 2274 matching lines @@
 
   // Signal a reference error if the expression is an invalid left-hand
   // side expression.  We could report this as a syntax error here but
   // for compatibility with JSC we choose to report the error at
   // runtime.
   if (expression == NULL || !expression->IsValidLeftHandSide()) {
     Handle<String> type = Factory::invalid_lhs_in_assignment_symbol();
     expression = NewThrowReferenceError(type);
   }
 
+  if (temp_scope_->StrictMode()) {
+    // Assignment to eval or arguments is disallowed in strict mode.
+    CheckStrictModeLValue(expression, "strict_lhs_assignment", CHECK_OK);
+  }
+
   Token::Value op = Next();  // Get assignment operator.
   int pos = scanner().location().beg_pos;
   Expression* right = ParseAssignmentExpression(accept_IN, CHECK_OK);
 
   // TODO(1231235): We try to estimate the set of properties set by
   // constructors. We define a new property whenever there is an
   // assignment to a property of 'this'. We should probably only add
   // properties if we haven't seen them before. Otherwise we'll
   // probably overestimate the number of properties.
   Property* property = expression ? expression->AsProperty() : NULL;
@@ skipping 206 matching lines @@
     op = Next();
     Expression* expression = ParseUnaryExpression(CHECK_OK);
     // Signal a reference error if the expression is an invalid
     // left-hand side expression.  We could report this as a syntax
     // error here but for compatibility with JSC we choose to report the
     // error at runtime.
     if (expression == NULL || !expression->IsValidLeftHandSide()) {
       Handle<String> type = Factory::invalid_lhs_in_prefix_op_symbol();
       expression = NewThrowReferenceError(type);
     }
+
+    if (temp_scope_->StrictMode()) {
+      // Prefix expression operand in strict mode may not be eval or arguments.
+      CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
+    }
+
     int position = scanner().location().beg_pos;
     IncrementOperation* increment = new IncrementOperation(op, expression);
     return new CountOperation(true /* prefix */, increment, position);
 
   } else {
     return ParsePostfixExpression(ok);
   }
 }
 
 
 Expression* Parser::ParsePostfixExpression(bool* ok) {
   // PostfixExpression ::
   //   LeftHandSideExpression ('++' | '--')?
 
   Expression* expression = ParseLeftHandSideExpression(CHECK_OK);
   if (!scanner().has_line_terminator_before_next() &&
       Token::IsCountOp(peek())) {
     // Signal a reference error if the expression is an invalid
     // left-hand side expression.  We could report this as a syntax
     // error here but for compatibility with JSC we choose to report the
     // error at runtime.
     if (expression == NULL || !expression->IsValidLeftHandSide()) {
       Handle<String> type = Factory::invalid_lhs_in_postfix_op_symbol();
       expression = NewThrowReferenceError(type);
     }
+
+    if (temp_scope_->StrictMode()) {
+      // Postfix expression operand in strict mode may not be eval or arguments.
+      CheckStrictModeLValue(expression, "strict_lhs_prefix", CHECK_OK);
+    }
+
     Token::Value next = Next();
     int position = scanner().location().beg_pos;
     IncrementOperation* increment = new IncrementOperation(next, expression);
     expression = new CountOperation(false /* postfix */, increment, position);
   }
   return expression;
 }
 
 
 Expression* Parser::ParseLeftHandSideExpression(bool* ok) {
@@ skipping 1129 matching lines @@
 Handle<String> Parser::ParseIdentifierName(bool* ok) {
   Token::Value next = Next();
   if (next != Token::IDENTIFIER && !Token::IsKeyword(next)) {
     ReportUnexpectedToken(next);
     *ok = false;
     return Handle<String>();
   }
   return GetSymbol(ok);
 }
 
+
+// Checks LHS expression for assignment and prefix/postfix increment/decrement
+// in strict mode.
+void Parser::CheckStrictModeLValue(Expression* expression,
+                                   const char* error,
+                                   bool* ok) {
+  ASSERT(temp_scope_->StrictMode());
+  VariableProxy* lhs = expression != NULL
+      ? expression->AsVariableProxy()
+      : NULL;
+
+  if (lhs != NULL && !lhs->is_this() && IsEvalOrArguments(lhs->name())) {
+    ReportMessage(error, Vector<const char*>::empty());
+    *ok = false;
+  }
+}
+
+
 // Checks whether octal literal last seen is between beg_pos and end_pos.
 // If so, reports an error.
 void Parser::CheckOctalLiteral(int beg_pos, int end_pos, bool* ok) {
   int octal = scanner().octal_position();
   if (beg_pos <= octal && octal <= end_pos) {
     ReportMessageAt(Scanner::Location(octal, octal + 1), "strict_octal_literal",
                     Vector<const char*>::empty());
     scanner().clear_octal_position();
     *ok = false;
   }
@@ skipping 1287 matching lines @@
       Handle<String> source = Handle<String>(String::cast(script->source()));
       result = parser.ParseProgram(source, info->is_global());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal