Issue 5870 - Implement the new ElemHideEmulation filter type

compiled/filter/ElemHideBase.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #pragma once
 
 #include <cstddef>
 
 #include "ActiveFilter.h"
 #include "../bindings/runtime.h"
 
 struct ElemHideData
 {
   String::size_type mDomainsEnd;
   String::size_type mSelectorStart;
+  bool mNeedConversion;

[sergei, 2018/02/05 14:51:06]

Do we really need this member for each instance of ElemHideBase? What do you
think about detecting whether a conversion is required in the constructor of
ElemHideBase?

[hub, 2018/02/07 04:13:37]

I can move mNeedConversion out of this and pass it to ElemHideBase::Parse().

The conversion in the constructor is a problem as it involved mutating
data.elemhide as well.

 
   bool HasDomains() const
   {
     return mDomainsEnd != 0;
   }
 
   DependentString GetDomainsSource(String& text) const
   {
     return DependentString(text, 0, mDomainsEnd);
   }
@@ skipping 15 matching lines @@
 };
 
 class ElemHideBase : public ActiveFilter
 {
 protected:
   ElemHideData mData;
 public:
   static constexpr Type classType = Type::ELEMHIDEBASE;
   explicit ElemHideBase(Type type, const String& text, const ElemHideData& data);
   static Type Parse(DependentString& text, ElemHideData& data);
+  static OwnedString ConvertFilter(const String& text, String::size_type& at);
 
   OwnedString BINDINGS_EXPORTED GetSelector() const;
   OwnedString BINDINGS_EXPORTED GetSelectorDomain() const;
 };
 
 typedef intrusive_ptr<ElemHideBase> ElemHideBasePtr;