Add strong mode.

src/preparser.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_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/v8.h"
 
 #include "src/bailout-reason.h"
@@ skipping 736 matching lines @@
         IsValidArrowParamListField::encode(valid_arrow_param_list));
   }
 
   static PreParserExpression EmptyArrowParamList() {
     // Any expression for which IsValidArrowParamList() returns true
     // will work here.
     return FromIdentifier(PreParserIdentifier::Default());
   }
 
   static PreParserExpression StringLiteral() {
-    return PreParserExpression(TypeField::encode(kStringLiteralExpression) |
-                               IsUseStrictField::encode(false));
+    return PreParserExpression(TypeField::encode(kStringLiteralExpression));
   }
 
   static PreParserExpression UseStrictStringLiteral() {
     return PreParserExpression(TypeField::encode(kStringLiteralExpression) |
                                IsUseStrictField::encode(true));
   }
 
+  static PreParserExpression UseSanityStringLiteral() {
+    return PreParserExpression(TypeField::encode(kStringLiteralExpression) |
+                               IsUseSanityField::encode(true));
+  }
+
   static PreParserExpression This() {
     return PreParserExpression(TypeField::encode(kExpression) |
                                ExpressionTypeField::encode(kThisExpression));
   }
 
   static PreParserExpression Super() {
     return PreParserExpression(TypeField::encode(kExpression) |
                                ExpressionTypeField::encode(kSuperExpression));
   }
 
@@ skipping 31 matching lines @@
 
   bool IsStringLiteral() const {
     return TypeField::decode(code_) == kStringLiteralExpression;
   }
 
   bool IsUseStrictLiteral() const {
     return TypeField::decode(code_) == kStringLiteralExpression &&
            IsUseStrictField::decode(code_);
   }
 
+  bool IsUseSanityLiteral() const {
+    return TypeField::decode(code_) == kStringLiteralExpression &&
+           IsUseSanityField::decode(code_);
+  }
+
   bool IsThis() const {
     return TypeField::decode(code_) == kExpression &&
            ExpressionTypeField::decode(code_) == kThisExpression;
   }
 
   bool IsThisProperty() const {
     return TypeField::decode(code_) == kExpression &&
            ExpressionTypeField::decode(code_) == kThisPropertyExpression;
   }
 
@@ skipping 88 matching lines @@
 
   // The first four bits are for the Type and Parenthesization.
   typedef BitField<Type, 0, 2> TypeField;
   typedef BitField<Parenthesization, TypeField::kNext, 2> ParenthesizationField;
 
   // The rest of the bits are interpreted depending on the value
   // of the Type field, so they can share the storage.
   typedef BitField<ExpressionType, ParenthesizationField::kNext, 3>
       ExpressionTypeField;
   typedef BitField<bool, ParenthesizationField::kNext, 1> IsUseStrictField;
+  typedef BitField<bool, IsUseStrictField::kNext, 1> IsUseSanityField;
   typedef BitField<bool, ParenthesizationField::kNext, 1>
       IsValidArrowParamListField;
   typedef BitField<PreParserIdentifier::Type, ParenthesizationField::kNext, 10>
       IdentifierTypeField;
 
   uint32_t code_;
 };
 
 
 // PreParserExpressionList doesn't actually store the expressions because
@@ skipping 21 matching lines @@
   }
 
   // Creates expression statement from expression.
   // Preserves being an unparenthesized string literal, possibly
   // "use strict".
   static PreParserStatement ExpressionStatement(
       PreParserExpression expression) {
     if (expression.IsUseStrictLiteral()) {
       return PreParserStatement(kUseStrictExpressionStatement);
     }
+    if (expression.IsUseSanityLiteral()) {
+      return PreParserStatement(kUseSanityExpressionStatement);
+    }
     if (expression.IsStringLiteral()) {
       return PreParserStatement(kStringLiteralExpressionStatement);
     }
     return Default();
   }
 
   bool IsStringLiteral() {
     return code_ == kStringLiteralExpressionStatement;
   }
 
   bool IsUseStrictLiteral() {
     return code_ == kUseStrictExpressionStatement;
   }
 
+  bool IsUseSanityLiteral() { return code_ == kUseSanityExpressionStatement; }
+
   bool IsFunctionDeclaration() {
     return code_ == kFunctionDeclaration;
   }
 
  private:
   enum Type {
     kUnknownStatement,
     kStringLiteralExpressionStatement,
     kUseStrictExpressionStatement,
+    kUseSanityExpressionStatement,
     kFunctionDeclaration
   };
 
   explicit PreParserStatement(Type code) : code_(code) {}
   Type code_;
 };
 
 
 
 // PreParserStatementList doesn't actually store the statements because
@@ skipping 2077 matching lines @@
       *ok = false;
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H