1/* 2 * (C) 1999-2003 Lars Knoll (knoll@kde.org) 3 * (C) 2002-2003 Dirk Mueller (mueller@kde.org) 4 * Copyright (C) 2002, 2005, 2006, 2007, 2012 Apple Inc. All rights reserved. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Library General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Library General Public License for more details. 15 * 16 * You should have received a copy of the GNU Library General Public License 17 * along with this library; see the file COPYING.LIB. If not, write to 18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA. 20 */ 21 22#include "config.h" 23#include "core/css/CSSRule.h" 24 25#include "core/css/CSSStyleSheet.h" 26#include "core/css/StyleRule.h" 27#include "core/css/StyleSheetContents.h" 28#include "platform/NotImplemented.h" 29 30namespace blink { 31 32// VC++ 2013 doesn't support EBCO (Empty Base Class Optimization), and having 33// multiple empty base classes makes the size of CSSRule bloat (Note that both 34// of GarbageCollectedFinalized and ScriptWrappableBase are empty classes). 35// See the following article for details. 36// http://social.msdn.microsoft.com/forums/vstudio/en-US/504c6598-6076-4acf-96b6-e6acb475d302/vc-multiple-inheritance-empty-base-classes-bloats-object-size 37// 38// FIXME: Remove ScriptWrappableBase from the base class list once VC++'s issue 39// gets fixed. 40// Note that we're going to split CSSRule class into two classes; CSSOMRule 41// (assumed name) which derives ScriptWrappable and CSSRule (new one) which 42// doesn't derive ScriptWrappable or ScriptWrappableBase. Then, we can safely 43// remove ScriptWrappableBase from the base class list. 44struct SameSizeAsCSSRule : public RefCountedWillBeGarbageCollectedFinalized<SameSizeAsCSSRule>, public ScriptWrappableBase { 45 virtual ~SameSizeAsCSSRule(); 46 unsigned char bitfields; 47 void* pointerUnion; 48}; 49 50COMPILE_ASSERT(sizeof(CSSRule) == sizeof(SameSizeAsCSSRule), CSSRule_should_stay_small); 51 52COMPILE_ASSERT(StyleRuleBase::Viewport == static_cast<StyleRuleBase::Type>(CSSRule::VIEWPORT_RULE), enums_should_match); 53 54void CSSRule::setCSSText(const String&) 55{ 56 notImplemented(); 57} 58 59const CSSParserContext& CSSRule::parserContext() const 60{ 61 CSSStyleSheet* styleSheet = parentStyleSheet(); 62 return styleSheet ? styleSheet->contents()->parserContext() : strictCSSParserContext(); 63} 64 65void CSSRule::trace(Visitor* visitor) 66{ 67#if ENABLE(OILPAN) 68 // This makes the parent link strong, which is different from the 69 // pre-oilpan world, where the parent link is mysteriously zeroed under 70 // some circumstances. 71 if (m_parentIsRule) 72 visitor->trace(m_parentRule); 73 else 74 visitor->trace(m_parentStyleSheet); 75#endif 76} 77 78} // namespace blink 79