1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
4 * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
5 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
6 * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
7 * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
8 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
9 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
10 * Copyright (C) Research In Motion Limited 2011. All rights reserved.
11 * Copyright (C) 2012 Google Inc. All rights reserved.
12 *
13 * This library is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU Library General Public
15 * License as published by the Free Software Foundation; either
16 * version 2 of the License, or (at your option) any later version.
17 *
18 * This library is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21 * Library General Public License for more details.
22 *
23 * You should have received a copy of the GNU Library General Public License
24 * along with this library; see the file COPYING.LIB.  If not, write to
25 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
26 * Boston, MA 02110-1301, USA.
27 */
28
29#include "config.h"
30#include "core/css/RuleSet.h"
31
32#include "core/HTMLNames.h"
33#include "core/css/CSSFontSelector.h"
34#include "core/css/CSSSelector.h"
35#include "core/css/CSSSelectorList.h"
36#include "core/css/SelectorChecker.h"
37#include "core/css/SelectorFilter.h"
38#include "core/css/StyleRuleImport.h"
39#include "core/css/StyleSheetContents.h"
40#include "core/html/track/TextTrackCue.h"
41#include "platform/RuntimeEnabledFeatures.h"
42#include "platform/TraceEvent.h"
43#include "platform/heap/HeapTerminatedArrayBuilder.h"
44#include "platform/weborigin/SecurityOrigin.h"
45
46#include "wtf/TerminatedArrayBuilder.h"
47
48namespace blink {
49
50using namespace HTMLNames;
51
52// -----------------------------------------------------------------
53
54static inline bool isSelectorMatchingHTMLBasedOnRuleHash(const CSSSelector& selector)
55{
56    if (selector.match() == CSSSelector::Tag) {
57        const AtomicString& selectorNamespace = selector.tagQName().namespaceURI();
58        if (selectorNamespace != starAtom && selectorNamespace != xhtmlNamespaceURI)
59            return false;
60        if (selector.relation() == CSSSelector::SubSelector) {
61            ASSERT(selector.tagHistory());
62            return isSelectorMatchingHTMLBasedOnRuleHash(*selector.tagHistory());
63        }
64        return true;
65    }
66    if (SelectorChecker::isCommonPseudoClassSelector(selector))
67        return true;
68    return selector.match() == CSSSelector::Id || selector.match() == CSSSelector::Class;
69}
70
71static inline bool selectorListContainsUncommonAttributeSelector(const CSSSelector* selector)
72{
73    const CSSSelectorList* selectorList = selector->selectorList();
74    if (!selectorList)
75        return false;
76    for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector)) {
77        for (const CSSSelector* component = selector; component; component = component->tagHistory()) {
78            if (component->isAttributeSelector())
79                return true;
80        }
81    }
82    return false;
83}
84
85static inline bool isCommonAttributeSelectorAttribute(const QualifiedName& attribute)
86{
87    // These are explicitly tested for equality in canShareStyleWithElement.
88    return attribute == typeAttr || attribute == readonlyAttr;
89}
90
91static inline bool containsUncommonAttributeSelector(const CSSSelector& selector)
92{
93    const CSSSelector* current = &selector;
94    for (; current; current = current->tagHistory()) {
95        // Allow certain common attributes (used in the default style) in the selectors that match the current element.
96        if (current->isAttributeSelector() && !isCommonAttributeSelectorAttribute(current->attribute()))
97            return true;
98        if (selectorListContainsUncommonAttributeSelector(current))
99            return true;
100        if (current->relation() != CSSSelector::SubSelector) {
101            current = current->tagHistory();
102            break;
103        }
104    }
105
106    for (; current; current = current->tagHistory()) {
107        if (current->isAttributeSelector())
108            return true;
109        if (selectorListContainsUncommonAttributeSelector(current))
110            return true;
111    }
112    return false;
113}
114
115static inline PropertyWhitelistType determinePropertyWhitelistType(const AddRuleFlags addRuleFlags, const CSSSelector& selector)
116{
117    for (const CSSSelector* component = &selector; component; component = component->tagHistory()) {
118        if (component->pseudoType() == CSSSelector::PseudoCue || (component->match() == CSSSelector::PseudoElement && component->value() == TextTrackCue::cueShadowPseudoId()))
119            return PropertyWhitelistCue;
120        if (component->pseudoType() == CSSSelector::PseudoFirstLetter)
121            return PropertyWhitelistFirstLetter;
122    }
123    return PropertyWhitelistNone;
124}
125
126RuleData::RuleData(StyleRule* rule, unsigned selectorIndex, unsigned position, AddRuleFlags addRuleFlags)
127    : m_rule(rule)
128    , m_selectorIndex(selectorIndex)
129    , m_isLastInArray(false)
130    , m_position(position)
131    , m_specificity(selector().specificity())
132    , m_hasMultipartSelector(!!selector().tagHistory())
133    , m_hasRightmostSelectorMatchingHTMLBasedOnRuleHash(isSelectorMatchingHTMLBasedOnRuleHash(selector()))
134    , m_containsUncommonAttributeSelector(blink::containsUncommonAttributeSelector(selector()))
135    , m_linkMatchType(SelectorChecker::determineLinkMatchType(selector()))
136    , m_hasDocumentSecurityOrigin(addRuleFlags & RuleHasDocumentSecurityOrigin)
137    , m_propertyWhitelistType(determinePropertyWhitelistType(addRuleFlags, selector()))
138{
139    ASSERT(m_position == position);
140    ASSERT(m_selectorIndex == selectorIndex);
141    SelectorFilter::collectIdentifierHashes(selector(), m_descendantSelectorIdentifierHashes, maximumIdentifierCount);
142}
143
144void RuleSet::addToRuleSet(const AtomicString& key, PendingRuleMap& map, const RuleData& ruleData)
145{
146    OwnPtrWillBeMember<WillBeHeapLinkedStack<RuleData> >& rules = map.add(key, nullptr).storedValue->value;
147    if (!rules)
148        rules = adoptPtrWillBeNoop(new WillBeHeapLinkedStack<RuleData>);
149    rules->push(ruleData);
150}
151
152static void extractValuesforSelector(const CSSSelector* selector, AtomicString& id, AtomicString& className, AtomicString& customPseudoElementName, AtomicString& tagName)
153{
154    switch (selector->match()) {
155    case CSSSelector::Id:
156        id = selector->value();
157        break;
158    case CSSSelector::Class:
159        className = selector->value();
160        break;
161    case CSSSelector::Tag:
162        if (selector->tagQName().localName() != starAtom)
163            tagName = selector->tagQName().localName();
164        break;
165    default:
166        break;
167    }
168    if (selector->isCustomPseudoElement())
169        customPseudoElementName = selector->value();
170}
171
172bool RuleSet::findBestRuleSetAndAdd(const CSSSelector& component, RuleData& ruleData)
173{
174    AtomicString id;
175    AtomicString className;
176    AtomicString customPseudoElementName;
177    AtomicString tagName;
178
179#ifndef NDEBUG
180    m_allRules.append(ruleData);
181#endif
182
183    const CSSSelector* it = &component;
184    for (; it && it->relation() == CSSSelector::SubSelector; it = it->tagHistory()) {
185        extractValuesforSelector(it, id, className, customPseudoElementName, tagName);
186    }
187    // FIXME: this null check should not be necessary. See crbug.com/358475
188    if (it)
189        extractValuesforSelector(it, id, className, customPseudoElementName, tagName);
190
191    // Prefer rule sets in order of most likely to apply infrequently.
192    if (!id.isEmpty()) {
193        addToRuleSet(id, ensurePendingRules()->idRules, ruleData);
194        return true;
195    }
196    if (!className.isEmpty()) {
197        addToRuleSet(className, ensurePendingRules()->classRules, ruleData);
198        return true;
199    }
200    if (!customPseudoElementName.isEmpty()) {
201        // Custom pseudos come before ids and classes in the order of tagHistory, and have a relation of
202        // ShadowPseudo between them. Therefore we should never be a situation where extractValuesforSelector
203        // finsd id and className in addition to custom pseudo.
204        ASSERT(id.isEmpty() && className.isEmpty());
205        addToRuleSet(customPseudoElementName, ensurePendingRules()->shadowPseudoElementRules, ruleData);
206        return true;
207    }
208
209    if (component.pseudoType() == CSSSelector::PseudoCue) {
210        m_cuePseudoRules.append(ruleData);
211        return true;
212    }
213
214    if (SelectorChecker::isCommonPseudoClassSelector(component)) {
215        switch (component.pseudoType()) {
216        case CSSSelector::PseudoLink:
217        case CSSSelector::PseudoVisited:
218        case CSSSelector::PseudoAnyLink:
219            m_linkPseudoClassRules.append(ruleData);
220            return true;
221        case CSSSelector::PseudoFocus:
222            m_focusPseudoClassRules.append(ruleData);
223            return true;
224        default:
225            ASSERT_NOT_REACHED();
226            return true;
227        }
228    }
229
230    if (!tagName.isEmpty()) {
231        addToRuleSet(tagName, ensurePendingRules()->tagRules, ruleData);
232        return true;
233    }
234
235    return false;
236}
237
238void RuleSet::addRule(StyleRule* rule, unsigned selectorIndex, AddRuleFlags addRuleFlags)
239{
240    RuleData ruleData(rule, selectorIndex, m_ruleCount++, addRuleFlags);
241    m_features.collectFeaturesFromRuleData(ruleData);
242
243    if (!findBestRuleSetAndAdd(ruleData.selector(), ruleData)) {
244        // If we didn't find a specialized map to stick it in, file under universal rules.
245        m_universalRules.append(ruleData);
246    }
247}
248
249void RuleSet::addPageRule(StyleRulePage* rule)
250{
251    ensurePendingRules(); // So that m_pageRules.shrinkToFit() gets called.
252    m_pageRules.append(rule);
253}
254
255void RuleSet::addViewportRule(StyleRuleViewport* rule)
256{
257    ensurePendingRules(); // So that m_viewportRules.shrinkToFit() gets called.
258    m_viewportRules.append(rule);
259}
260
261void RuleSet::addFontFaceRule(StyleRuleFontFace* rule)
262{
263    ensurePendingRules(); // So that m_fontFaceRules.shrinkToFit() gets called.
264    m_fontFaceRules.append(rule);
265}
266
267void RuleSet::addKeyframesRule(StyleRuleKeyframes* rule)
268{
269    ensurePendingRules(); // So that m_keyframesRules.shrinkToFit() gets called.
270    m_keyframesRules.append(rule);
271}
272
273void RuleSet::addChildRules(const WillBeHeapVector<RefPtrWillBeMember<StyleRuleBase> >& rules, const MediaQueryEvaluator& medium, AddRuleFlags addRuleFlags)
274{
275    for (unsigned i = 0; i < rules.size(); ++i) {
276        StyleRuleBase* rule = rules[i].get();
277
278        if (rule->isStyleRule()) {
279            StyleRule* styleRule = toStyleRule(rule);
280
281            const CSSSelectorList& selectorList = styleRule->selectorList();
282            for (size_t selectorIndex = 0; selectorIndex != kNotFound; selectorIndex = selectorList.indexOfNextSelectorAfter(selectorIndex)) {
283                if (selectorList.selectorCrossesTreeScopes(selectorIndex)) {
284                    m_treeBoundaryCrossingRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
285                } else if (selectorList.hasShadowDistributedAt(selectorIndex)) {
286                    m_shadowDistributedRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
287                } else {
288                    addRule(styleRule, selectorIndex, addRuleFlags);
289                }
290            }
291        } else if (rule->isPageRule()) {
292            addPageRule(toStyleRulePage(rule));
293        } else if (rule->isMediaRule()) {
294            StyleRuleMedia* mediaRule = toStyleRuleMedia(rule);
295            if ((!mediaRule->mediaQueries() || medium.eval(mediaRule->mediaQueries(), &m_viewportDependentMediaQueryResults)))
296                addChildRules(mediaRule->childRules(), medium, addRuleFlags);
297        } else if (rule->isFontFaceRule()) {
298            addFontFaceRule(toStyleRuleFontFace(rule));
299        } else if (rule->isKeyframesRule()) {
300            addKeyframesRule(toStyleRuleKeyframes(rule));
301        } else if (rule->isViewportRule()) {
302            addViewportRule(toStyleRuleViewport(rule));
303        } else if (rule->isSupportsRule() && toStyleRuleSupports(rule)->conditionIsSupported()) {
304            addChildRules(toStyleRuleSupports(rule)->childRules(), medium, addRuleFlags);
305        }
306    }
307}
308
309void RuleSet::addRulesFromSheet(StyleSheetContents* sheet, const MediaQueryEvaluator& medium, AddRuleFlags addRuleFlags)
310{
311    TRACE_EVENT0("blink", "RuleSet::addRulesFromSheet");
312
313    ASSERT(sheet);
314
315    addRuleFlags = static_cast<AddRuleFlags>(addRuleFlags | RuleCanUseFastCheckSelector);
316    const WillBeHeapVector<RefPtrWillBeMember<StyleRuleImport> >& importRules = sheet->importRules();
317    for (unsigned i = 0; i < importRules.size(); ++i) {
318        StyleRuleImport* importRule = importRules[i].get();
319        if (importRule->styleSheet() && (!importRule->mediaQueries() || medium.eval(importRule->mediaQueries(), &m_viewportDependentMediaQueryResults)))
320            addRulesFromSheet(importRule->styleSheet(), medium, addRuleFlags);
321    }
322
323    addChildRules(sheet->childRules(), medium, addRuleFlags);
324}
325
326void RuleSet::addStyleRule(StyleRule* rule, AddRuleFlags addRuleFlags)
327{
328    for (size_t selectorIndex = 0; selectorIndex != kNotFound; selectorIndex = rule->selectorList().indexOfNextSelectorAfter(selectorIndex))
329        addRule(rule, selectorIndex, addRuleFlags);
330}
331
332void RuleSet::compactPendingRules(PendingRuleMap& pendingMap, CompactRuleMap& compactMap)
333{
334    PendingRuleMap::iterator end = pendingMap.end();
335    for (PendingRuleMap::iterator it = pendingMap.begin(); it != end; ++it) {
336        OwnPtrWillBeRawPtr<WillBeHeapLinkedStack<RuleData> > pendingRules = it->value.release();
337        CompactRuleMap::ValueType* compactRules = compactMap.add(it->key, nullptr).storedValue;
338
339        WillBeHeapTerminatedArrayBuilder<RuleData> builder(compactRules->value.release());
340        builder.grow(pendingRules->size());
341        while (!pendingRules->isEmpty()) {
342            builder.append(pendingRules->peek());
343            pendingRules->pop();
344        }
345
346        compactRules->value = builder.release();
347    }
348}
349
350void RuleSet::compactRules()
351{
352    ASSERT(m_pendingRules);
353    OwnPtrWillBeRawPtr<PendingRuleMaps> pendingRules = m_pendingRules.release();
354    compactPendingRules(pendingRules->idRules, m_idRules);
355    compactPendingRules(pendingRules->classRules, m_classRules);
356    compactPendingRules(pendingRules->tagRules, m_tagRules);
357    compactPendingRules(pendingRules->shadowPseudoElementRules, m_shadowPseudoElementRules);
358    m_linkPseudoClassRules.shrinkToFit();
359    m_cuePseudoRules.shrinkToFit();
360    m_focusPseudoClassRules.shrinkToFit();
361    m_universalRules.shrinkToFit();
362    m_pageRules.shrinkToFit();
363    m_viewportRules.shrinkToFit();
364    m_fontFaceRules.shrinkToFit();
365    m_keyframesRules.shrinkToFit();
366    m_treeBoundaryCrossingRules.shrinkToFit();
367    m_shadowDistributedRules.shrinkToFit();
368}
369
370void MinimalRuleData::trace(Visitor* visitor)
371{
372    visitor->trace(m_rule);
373}
374
375void RuleData::trace(Visitor* visitor)
376{
377    visitor->trace(m_rule);
378}
379
380void RuleSet::PendingRuleMaps::trace(Visitor* visitor)
381{
382#if ENABLE(OILPAN)
383    visitor->trace(idRules);
384    visitor->trace(classRules);
385    visitor->trace(tagRules);
386    visitor->trace(shadowPseudoElementRules);
387#endif
388}
389
390void RuleSet::trace(Visitor* visitor)
391{
392#if ENABLE(OILPAN)
393    visitor->trace(m_idRules);
394    visitor->trace(m_classRules);
395    visitor->trace(m_tagRules);
396    visitor->trace(m_shadowPseudoElementRules);
397    visitor->trace(m_linkPseudoClassRules);
398    visitor->trace(m_cuePseudoRules);
399    visitor->trace(m_focusPseudoClassRules);
400    visitor->trace(m_universalRules);
401    visitor->trace(m_features);
402    visitor->trace(m_pageRules);
403    visitor->trace(m_viewportRules);
404    visitor->trace(m_fontFaceRules);
405    visitor->trace(m_keyframesRules);
406    visitor->trace(m_treeBoundaryCrossingRules);
407    visitor->trace(m_shadowDistributedRules);
408    visitor->trace(m_viewportDependentMediaQueryResults);
409    visitor->trace(m_pendingRules);
410#ifndef NDEBUG
411    visitor->trace(m_allRules);
412#endif
413#endif
414}
415
416#ifndef NDEBUG
417void RuleSet::show()
418{
419    for (WillBeHeapVector<RuleData>::const_iterator it = m_allRules.begin(); it != m_allRules.end(); ++it)
420        it->selector().show();
421}
422#endif
423
424} // namespace blink
425