style/invalidation/element/
relative_selector.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! Invalidation of element styles relative selectors.
6
7use crate::data::ElementData;
8use crate::dom::{TElement, TNode};
9#[cfg(feature = "gecko")]
10use crate::gecko_bindings::structs::ServoElementSnapshotTable;
11use crate::invalidation::element::element_wrapper::ElementWrapper;
12use crate::invalidation::element::invalidation_map::{
13    AdditionalRelativeSelectorInvalidationMap, Dependency, DependencyInvalidationKind,
14    InvalidationMap, NormalDependencyInvalidationKind, RelativeDependencyInvalidationKind,
15    ScopeDependencyInvalidationKind, TSStateForInvalidation,
16};
17use crate::invalidation::element::invalidator::{
18    note_scope_dependency_force_at_subject, DescendantInvalidationLists, Invalidation,
19    InvalidationProcessor, InvalidationResult, InvalidationVector, SiblingTraversalMap,
20    TreeStyleInvalidator,
21};
22use crate::invalidation::element::restyle_hints::RestyleHint;
23use crate::invalidation::element::state_and_attributes::{
24    check_dependency, dependency_may_be_relevant, invalidated_descendants, invalidated_self,
25    invalidated_sibling, push_invalidation, should_process_descendants,
26};
27#[cfg(feature = "servo")]
28use crate::selector_parser::SnapshotMap as ServoElementSnapshotTable;
29use crate::stylist::{CascadeData, Stylist};
30use dom::ElementState;
31use rustc_hash::FxHashMap;
32use selectors::matching::{
33    matches_selector, ElementSelectorFlags, IncludeStartingStyle, MatchingContext,
34    MatchingForInvalidation, MatchingMode, NeedsSelectorFlags, QuirksMode, SelectorCaches,
35    VisitedHandlingMode,
36};
37use selectors::parser::SelectorKey;
38use selectors::OpaqueElement;
39use smallvec::{smallvec, SmallVec};
40use std::ops::DerefMut;
41
42/// Kind of DOM mutation this relative selector invalidation is being carried out in.
43#[derive(Clone, Copy)]
44pub enum DomMutationOperation {
45    /// Insertion operation, can cause side effect, but presumed already happened.
46    Insert,
47    /// Append operation, cannot cause side effect.
48    Append,
49    /// Removal operation, can cause side effect, but presumed already happened. Sibling relationships are destroyed.
50    Remove,
51    /// Invalidating for side effect of a DOM operation, for the previous sibling.
52    SideEffectPrevSibling,
53    /// Invalidating for side effect of a DOM operation, for the next sibling.
54    SideEffectNextSibling,
55}
56
57impl DomMutationOperation {
58    fn accept<E: TElement>(&self, d: &Dependency, e: E) -> bool {
59        match self {
60            Self::Insert | Self::Append | Self::Remove => {
61                !e.relative_selector_search_direction().is_empty()
62            },
63            // `:has(+ .a + .b)` with `.anchor + .a + .remove + .b` - `.a` would be present
64            // in the search path.
65            Self::SideEffectPrevSibling => {
66                !e.relative_selector_search_direction().is_empty()
67                    && d.right_combinator_is_next_sibling()
68            },
69            // If an element is being removed and would cause next-sibling match to happen,
70            // e.g. `:has(+ .a)` with `.anchor + .remove + .a`, `.a` isn't yet searched
71            // for relative selector matching.
72            Self::SideEffectNextSibling => d.dependency_is_relative_with_single_next_sibling(),
73        }
74    }
75
76    fn is_side_effect(&self) -> bool {
77        match self {
78            Self::Insert | Self::Append | Self::Remove => false,
79            Self::SideEffectPrevSibling | Self::SideEffectNextSibling => true,
80        }
81    }
82}
83
84/// Context required to try and optimize away relative dependencies.
85struct OptimizationContext<'a, E: TElement> {
86    sibling_traversal_map: &'a SiblingTraversalMap<E>,
87    quirks_mode: QuirksMode,
88    operation: DomMutationOperation,
89}
90
91impl<'a, E: TElement> OptimizationContext<'a, E> {
92    fn can_be_ignored(
93        &self,
94        is_subtree: bool,
95        element: E,
96        host: Option<OpaqueElement>,
97        dependency: &Dependency,
98        leftmost_collapse_offset: usize,
99    ) -> bool {
100        if is_subtree {
101            // Subtree elements don't have unaffected sibling to look at.
102            return false;
103        }
104        debug_assert!(
105            matches!(
106                dependency.invalidation_kind(),
107                DependencyInvalidationKind::Relative(..)
108            ),
109            "Non-relative selector being evaluated for optimization"
110        );
111        // This optimization predecates on the fact that there may be a sibling that can readily
112        // "take over" this element.
113        let sibling = match self.sibling_traversal_map.prev_sibling_for(&element) {
114            None => {
115                if matches!(self.operation, DomMutationOperation::Append) {
116                    return false;
117                }
118                match self.sibling_traversal_map.next_sibling_for(&element) {
119                    Some(s) => s,
120                    None => return false,
121                }
122            },
123            Some(s) => s,
124        };
125        {
126            // Run through the affected compund.
127            let mut iter = dependency.selector.iter_from(dependency.selector_offset);
128            while let Some(c) = iter.next() {
129                if c.has_indexed_selector_in_subject() {
130                    // We do not calculate indices during invalidation as they're wasteful - as a side effect,
131                    // such selectors always return true, breaking this optimization. Note that we only check
132                    // this compound only because the check to skip compares against this element's sibling.
133                    // i.e. Given `:has(:nth-child(2) .foo)`, we'd try to find `.foo`'s sibling, which
134                    // shares `:nth-child` up the selector.
135                    return false;
136                }
137            }
138        }
139        let dependency_is_rightmost = dependency.selector_offset == 0;
140        if !dependency_is_rightmost {
141            let combinator = dependency
142                .selector
143                .combinator_at_match_order(dependency.selector_offset - 1);
144            if combinator.is_ancestor() {
145                // We can safely ignore these, since we're about to traverse the
146                // rest of the affected tree anyway to find the rightmost invalidated element.
147                return true;
148            }
149            if combinator.is_sibling() && matches!(self.operation, DomMutationOperation::Append) {
150                // If we're at the top of the DOM tree being mutated, we can ignore it if the
151                // operation is append - we know we'll cover all the later siblings and their descendants.
152                return true;
153            }
154        }
155
156        // We have a situation like `:has(.item .item + .item + .item)`, where the first element in the sibling
157        // chain position (i.e. The element matched by the second `.item` from the left) mutates. By the time we
158        // get here, we've collapsed the 4 dependencies for each of `.item` position into one at the rightmost
159        // position. Before we look for a standin, we need to find which `.item` this element matches - Doing
160        // that would generate more work than it saves.
161        if dependency_is_rightmost
162            && leftmost_collapse_offset != dependency.selector_offset
163            && self
164                .sibling_traversal_map
165                .next_sibling_for(&element)
166                .is_some()
167        {
168            return false;
169        }
170
171        let mut caches = SelectorCaches::default();
172        let mut matching_context = MatchingContext::new(
173            MatchingMode::Normal,
174            None,
175            &mut caches,
176            self.quirks_mode,
177            NeedsSelectorFlags::No,
178            MatchingForInvalidation::Yes,
179        );
180        matching_context.current_host = host;
181        let sibling_matches = matches_selector(
182            &dependency.selector,
183            dependency.selector_offset,
184            None,
185            &sibling,
186            &mut matching_context,
187        );
188        if sibling_matches {
189            // Remember that at this point, we know that the combinator to the right of this
190            // compound is a sibling combinator. Effectively, we've found a standin for the
191            // element we're mutating.
192            // e.g. Given `:has(... .a ~ .b ...)`, we're the mutating element matching `... .a`,
193            // if we find a sibling that matches the `... .a`, it can stand in for us.
194            debug_assert!(
195                dependency.next.is_some(),
196                "No relative selector outer dependency?"
197            );
198            return dependency.next.as_ref().map_or(false, |deps| {
199                // ... However, if the standin sibling can be the anchor, we can't skip it, since
200                // that sibling should be invlidated to become the anchor.
201                let next = &deps.as_ref().slice()[0];
202                !matches_selector(
203                    &next.selector,
204                    next.selector_offset,
205                    None,
206                    &sibling,
207                    &mut matching_context,
208                )
209            });
210        }
211        // Ok, there's no standin element - but would this element have matched the upstream
212        // selector anyway? If we don't, either the match exists somewhere far from us
213        // (In which case our mutation doesn't really matter), or it doesn't exist at all,
214        // so we can just skip the invalidation.
215        let (combinator, prev_offset) = {
216            let mut iter = dependency.selector.iter_from(dependency.selector_offset);
217            let mut o = dependency.selector_offset;
218            while iter.next().is_some() {
219                o += 1;
220            }
221            let combinator = iter.next_sequence();
222            o += 1;
223            debug_assert!(
224                combinator.is_some(),
225                "Should at least see a relative combinator"
226            );
227            (combinator.unwrap(), o)
228        };
229        if combinator.is_sibling() && prev_offset >= dependency.selector.len() - 1 {
230            // Hit the relative combinator - we don't have enough information to
231            // see if there's going to be a downstream match.
232            return false;
233        }
234        !matches_selector(
235            &dependency.selector,
236            dependency.selector_offset,
237            None,
238            &element,
239            &mut matching_context,
240        )
241    }
242}
243
244/// Overall invalidator for handling relative selector invalidations.
245pub struct RelativeSelectorInvalidator<'a, 'b, E>
246where
247    E: TElement + 'a,
248{
249    /// Element triggering the invalidation.
250    pub element: E,
251    /// Quirks mode of the current invalidation.
252    pub quirks_mode: QuirksMode,
253    /// Snapshot containing changes to invalidate against.
254    /// Can be None if it's a DOM mutation.
255    pub snapshot_table: Option<&'b ServoElementSnapshotTable>,
256    /// Callback to trigger when the subject element is invalidated.
257    pub invalidated: fn(E, &InvalidationResult),
258    /// The traversal map that should be used to process invalidations.
259    pub sibling_traversal_map: SiblingTraversalMap<E>,
260    /// Marker for 'a lifetime.
261    pub _marker: ::std::marker::PhantomData<&'a ()>,
262}
263
264struct RelativeSelectorInvalidation<'a> {
265    host: Option<OpaqueElement>,
266    kind: RelativeDependencyInvalidationKind,
267    dependency: &'a Dependency,
268}
269
270type ElementDependencies<'a> = SmallVec<[(Option<OpaqueElement>, &'a Dependency); 1]>;
271type Dependencies<'a, E> = SmallVec<[(E, ElementDependencies<'a>); 1]>;
272type AlreadyInvalidated<'a, E> = SmallVec<[AlreadyInvalidatedEntry<'a, E>; 2]>;
273
274struct AlreadyInvalidatedEntry<'a, E>
275where
276    E: TElement + 'a,
277{
278    /// Element where the invalidation will begin.
279    element: E,
280    /// The current shadow host.
281    host: Option<OpaqueElement>,
282    /// Dependency chain for this invalidation.
283    dependency: &'a Dependency,
284    /// The offset, of the leftmost dependencies that this
285    /// invalidation collapsed. See the `update()` function
286    /// for more information.
287    leftmost_collapse_offset: usize,
288}
289
290impl<'a, E> AlreadyInvalidatedEntry<'a, E>
291where
292    E: TElement + 'a,
293{
294    fn new(element: E, host: Option<OpaqueElement>, dependency: &'a Dependency) -> Self {
295        Self {
296            element,
297            host,
298            dependency,
299            leftmost_collapse_offset: dependency.selector_offset,
300        }
301    }
302
303    /// Update this invalidation with a new invalidation that may collapse with it.
304    fn update(&mut self, element: E, host: Option<OpaqueElement>, dependency: &'a Dependency) {
305        // This dependency should invalidate the same way - Collapse the invalidation
306        // to a more general case so we don't do duplicate work.
307        // e.g. For `:has(.item .item + .item + .item)`, since the anchor would be located
308        // in the ancestor chain for any invalidation triggered by any `.item` compound,
309        // 4 entries can collapse into one - but keep track of the leftmost offset.
310        if self.dependency.selector_offset > dependency.selector_offset {
311            *self = Self {
312                element,
313                host,
314                dependency,
315                leftmost_collapse_offset: self.leftmost_collapse_offset,
316            };
317        } else if self.leftmost_collapse_offset < dependency.selector_offset {
318            self.leftmost_collapse_offset = dependency.selector_offset;
319        }
320    }
321}
322
323/// Interface for collecting relative selector dependencies.
324pub struct RelativeSelectorDependencyCollector<'a, E>
325where
326    E: TElement,
327{
328    /// Dependencies that need to run through the normal invalidation that may generate
329    /// a relative selector invalidation.
330    dependencies: FxHashMap<E, ElementDependencies<'a>>,
331    /// Dependencies that created an invalidation right away.
332    invalidations: AlreadyInvalidated<'a, E>,
333    /// The top element in the subtree being invalidated.
334    top: E,
335    /// Optional context that will be used to try and skip invalidations
336    /// by running selector matches.
337    optimization_context: Option<OptimizationContext<'a, E>>,
338}
339
340type Invalidations<'a> = SmallVec<[RelativeSelectorInvalidation<'a>; 1]>;
341type InnerInvalidations<'a, E> = SmallVec<[(E, RelativeSelectorInvalidation<'a>); 1]>;
342
343struct ToInvalidate<'a, E: TElement + 'a> {
344    /// Dependencies to run through normal invalidator.
345    dependencies: Dependencies<'a, E>,
346    /// Dependencies already invalidated.
347    invalidations: Invalidations<'a>,
348}
349
350impl<'a, E: TElement + 'a> Default for ToInvalidate<'a, E> {
351    fn default() -> Self {
352        Self {
353            dependencies: Dependencies::default(),
354            invalidations: Invalidations::default(),
355        }
356    }
357}
358
359fn invalidation_can_collapse(
360    a: &Dependency,
361    b: &Dependency,
362    allow_indexed_selectors: bool,
363) -> bool {
364    // We want to detect identical dependencies that occur at different
365    // compounds but has the identical compound in the same selector,
366    // e.g. :has(.item .item).
367
368    // If they trigger different invalidations, they shouldn't be collapsed.
369    if a.relative_invalidation_kind() != b.relative_invalidation_kind() {
370        return false;
371    }
372
373    // Not in the same selector, trivially skipped.
374    if SelectorKey::new(&a.selector) != SelectorKey::new(&b.selector) {
375        return false;
376    }
377
378    // Check that this is in the same nesting.
379    // TODO(dshin): @scope probably brings more subtleties...
380    let mut a_next = a.next.as_ref();
381    let mut b_next = b.next.as_ref();
382    while let (Some(a_deps), Some(b_deps)) = (a_next, b_next) {
383        // This is a bit subtle - but we don't need to do the checks we do at higher levels.
384        // Cases like `:is(.item .foo) :is(.item .foo)` where `.item` invalidates would
385        // point to different dependencies, pointing to the same outer selector, but
386        // differing in selector offset.
387        let a_n = &a_deps.as_ref().slice()[0];
388        let b_n = &b_deps.as_ref().slice()[0];
389        if SelectorKey::new(&a_n.selector) != SelectorKey::new(&b_n.selector) {
390            return false;
391        }
392        a_next = a_n.next.as_ref();
393        b_next = b_n.next.as_ref();
394    }
395    if a_next.is_some() || b_next.is_some() {
396        return false;
397    }
398
399    // Ok, now, do the compounds actually match?
400    // This can get expensive quickly, but we're assuming that:
401    //
402    //   * In most cases, authors don't generally duplicate compounds in a selector, so
403    //     this fails quickly
404    //   * In cases where compounds are duplicated, reducing the number of invalidations
405    //     has a payoff that offsets the comparison cost
406    //
407    // Note, `.a.b` != `.b.a` - doesn't affect correctness, though.
408    // TODO(dshin): Caching this may be worth it as well?
409    let mut a_iter = a.selector.iter_from(a.selector_offset);
410    let mut b_iter = b.selector.iter_from(b.selector_offset);
411    loop {
412        let a_component = a_iter.next();
413        let b_component = b_iter.next();
414
415        if a_component != b_component {
416            return false;
417        }
418        let Some(component) = a_component else {
419            return true;
420        };
421        if !allow_indexed_selectors && component.has_indexed_selector_in_subject() {
422            // The element's positioning matters, so can't collapse.
423            return false;
424        }
425    }
426}
427
428impl<'a, E> RelativeSelectorDependencyCollector<'a, E>
429where
430    E: TElement,
431{
432    fn new(top: E, optimization_context: Option<OptimizationContext<'a, E>>) -> Self {
433        Self {
434            dependencies: FxHashMap::default(),
435            invalidations: AlreadyInvalidated::default(),
436            top,
437            optimization_context,
438        }
439    }
440
441    fn insert_invalidation(
442        &mut self,
443        element: E,
444        dependency: &'a Dependency,
445        host: Option<OpaqueElement>,
446    ) {
447        let in_subtree = element != self.top;
448        if let Some(entry) = self.invalidations.iter_mut().find(|entry| {
449            // If we're in the subtree of DOM manipulation - worrying the about positioning of this element
450            // is irrelevant, because the DOM structure is either completely new or about to go away.
451            let both_in_subtree = in_subtree && entry.element != self.top;
452            // If we're considering the same element for invalidation, their evaluation of the indexed selector
453            // is identical by definition.
454            let same_element = element == entry.element;
455            invalidation_can_collapse(
456                dependency,
457                entry.dependency,
458                both_in_subtree || same_element,
459            )
460        }) {
461            entry.update(element, host, dependency)
462        } else {
463            self.invalidations
464                .push(AlreadyInvalidatedEntry::new(element, host, dependency));
465        }
466    }
467
468    /// Add this dependency, if it is unique (i.e. Different outer dependency or same outer dependency
469    /// but requires a different invalidation traversal).
470    pub fn add_dependency(
471        &mut self,
472        dependency: &'a Dependency,
473        element: E,
474        host: Option<OpaqueElement>,
475    ) {
476        match dependency.invalidation_kind() {
477            DependencyInvalidationKind::FullSelector => unreachable!(),
478            DependencyInvalidationKind::Normal(..) | DependencyInvalidationKind::Scope(..) => {
479                self.dependencies
480                    .entry(element)
481                    .and_modify(|v| v.push((host, dependency)))
482                    .or_default()
483                    .push((host, dependency));
484            },
485            DependencyInvalidationKind::Relative(kind) => {
486                debug_assert!(
487                    dependency.next.is_some(),
488                    "Orphaned inner relative selector?"
489                );
490                if element != self.top
491                    && matches!(
492                        kind,
493                        RelativeDependencyInvalidationKind::Parent
494                            | RelativeDependencyInvalidationKind::PrevSibling
495                            | RelativeDependencyInvalidationKind::EarlierSibling
496                    )
497                {
498                    return;
499                }
500                self.insert_invalidation(element, dependency, host);
501            },
502        };
503    }
504
505    /// Get the dependencies in a list format.
506    fn get(self) -> ToInvalidate<'a, E> {
507        let mut result = ToInvalidate::default();
508        for invalidation in self.invalidations {
509            match invalidation.dependency.invalidation_kind() {
510                DependencyInvalidationKind::FullSelector => unreachable!(),
511                DependencyInvalidationKind::Normal(_) | DependencyInvalidationKind::Scope(_) => {
512                    unreachable!("Inner selector in invalidation?")
513                },
514                DependencyInvalidationKind::Relative(kind) => {
515                    if let Some(context) = self.optimization_context.as_ref() {
516                        if context.can_be_ignored(
517                            invalidation.element != self.top,
518                            invalidation.element,
519                            invalidation.host,
520                            invalidation.dependency,
521                            invalidation.leftmost_collapse_offset,
522                        ) {
523                            continue;
524                        }
525                    }
526                    let dependency = &invalidation.dependency.next.as_ref().unwrap().slice()[0];
527                    result.invalidations.push(RelativeSelectorInvalidation {
528                        kind,
529                        host: invalidation.host,
530                        dependency,
531                    });
532                    // We move the invalidation up to the top of the subtree to avoid unnecessary traveral, but
533                    // this means that we need to take ancestor-earlier sibling invalidations into account, as
534                    // they'd look into earlier siblings of the top of the subtree as well.
535                    if invalidation.element != self.top
536                        && matches!(
537                            kind,
538                            RelativeDependencyInvalidationKind::AncestorEarlierSibling
539                                | RelativeDependencyInvalidationKind::AncestorPrevSibling
540                        )
541                    {
542                        result.invalidations.push(RelativeSelectorInvalidation {
543                            kind: if matches!(
544                                kind,
545                                RelativeDependencyInvalidationKind::AncestorPrevSibling
546                            ) {
547                                RelativeDependencyInvalidationKind::PrevSibling
548                            } else {
549                                RelativeDependencyInvalidationKind::EarlierSibling
550                            },
551                            host: invalidation.host,
552                            dependency,
553                        });
554                    }
555                },
556            };
557        }
558        for (key, element_dependencies) in self.dependencies {
559            // At least for now, we don't try to optimize away dependencies emitted from nested selectors.
560            result.dependencies.push((key, element_dependencies));
561        }
562        result
563    }
564
565    fn collect_all_dependencies_for_element(
566        &mut self,
567        element: E,
568        scope: Option<OpaqueElement>,
569        quirks_mode: QuirksMode,
570        map: &'a InvalidationMap,
571        additional_relative_selector_invalidation_map: &'a AdditionalRelativeSelectorInvalidationMap,
572        operation: DomMutationOperation,
573    ) {
574        element
575            .id()
576            .map(|v| match map.id_to_selector.get(v, quirks_mode) {
577                Some(v) => {
578                    for dependency in v {
579                        if !operation.accept(dependency, element) {
580                            continue;
581                        }
582                        self.add_dependency(dependency, element, scope);
583                    }
584                },
585                None => (),
586            });
587        element.each_class(|v| match map.class_to_selector.get(v, quirks_mode) {
588            Some(v) => {
589                for dependency in v {
590                    if !operation.accept(dependency, element) {
591                        continue;
592                    }
593                    self.add_dependency(dependency, element, scope);
594                }
595            },
596            None => (),
597        });
598        element.each_custom_state(|v| match map.custom_state_affecting_selectors.get(v) {
599            Some(v) => {
600                for dependency in v {
601                    if !operation.accept(dependency, element) {
602                        continue;
603                    }
604                    self.add_dependency(dependency, element, scope);
605                }
606            },
607            None => (),
608        });
609        element.each_attr_name(|v| match map.other_attribute_affecting_selectors.get(v) {
610            Some(v) => {
611                for dependency in v {
612                    if !operation.accept(dependency, element) {
613                        continue;
614                    }
615                    self.add_dependency(dependency, element, scope);
616                }
617            },
618            None => (),
619        });
620        let state = element.state();
621        map.state_affecting_selectors.lookup_with_additional(
622            element,
623            quirks_mode,
624            None,
625            &[],
626            ElementState::empty(),
627            |dependency| {
628                if !dependency.state.intersects(state) {
629                    return true;
630                }
631                if !operation.accept(&dependency.dep, element) {
632                    return true;
633                }
634                self.add_dependency(&dependency.dep, element, scope);
635                true
636            },
637        );
638
639        additional_relative_selector_invalidation_map
640            .ts_state_to_selector
641            .lookup_with_additional(
642                element,
643                quirks_mode,
644                None,
645                &[],
646                ElementState::empty(),
647                |dependency| {
648                    if !operation.accept(&dependency.dep, element) {
649                        return true;
650                    }
651                    // This section contain potential optimization for not running full invalidation -
652                    // consult documentation in `TSStateForInvalidation`.
653                    if dependency.state.may_be_optimized() {
654                        if operation.is_side_effect() {
655                            // Side effect operations act on element not being mutated, so they can't
656                            // change the match outcome of these optimizable pseudoclasses.
657                            return true;
658                        }
659                        debug_assert!(
660                            self.optimization_context.is_some(),
661                            "Optimization context not available for DOM mutation?"
662                        );
663                        if dependency.state.contains(TSStateForInvalidation::EMPTY)
664                            && element.first_element_child().is_some()
665                        {
666                            return true;
667                        }
668
669                        let sibling_traversal_map = self
670                            .optimization_context
671                            .as_ref()
672                            .unwrap()
673                            .sibling_traversal_map;
674                        if dependency
675                            .state
676                            .contains(TSStateForInvalidation::NTH_EDGE_FIRST)
677                            && sibling_traversal_map.prev_sibling_for(&element).is_some()
678                        {
679                            return true;
680                        }
681
682                        if dependency
683                            .state
684                            .contains(TSStateForInvalidation::NTH_EDGE_LAST)
685                            && sibling_traversal_map.next_sibling_for(&element).is_some()
686                        {
687                            return true;
688                        }
689                    }
690                    self.add_dependency(&dependency.dep, element, scope);
691                    true
692                },
693            );
694
695        if let Some(v) = additional_relative_selector_invalidation_map
696            .type_to_selector
697            .get(element.local_name())
698        {
699            for dependency in v {
700                if !operation.accept(dependency, element) {
701                    continue;
702                }
703                self.add_dependency(dependency, element, scope);
704            }
705        }
706
707        for dependency in &additional_relative_selector_invalidation_map.any_to_selector {
708            if !operation.accept(dependency, element) {
709                continue;
710            }
711            self.add_dependency(dependency, element, scope);
712        }
713    }
714
715    fn is_empty(&self) -> bool {
716        self.invalidations.is_empty() && self.dependencies.is_empty()
717    }
718}
719
720impl<'a, 'b, E> RelativeSelectorInvalidator<'a, 'b, E>
721where
722    E: TElement + 'a,
723{
724    /// Gather relative selector dependencies for the given element, and invalidate as necessary.
725    #[inline(never)]
726    pub fn invalidate_relative_selectors_for_this<F>(
727        self,
728        stylist: &'a Stylist,
729        mut gather_dependencies: F,
730    ) where
731        F: FnMut(
732            &E,
733            Option<OpaqueElement>,
734            &'a CascadeData,
735            QuirksMode,
736            &mut RelativeSelectorDependencyCollector<'a, E>,
737        ),
738    {
739        let mut collector = RelativeSelectorDependencyCollector::new(self.element, None);
740        stylist.for_each_cascade_data_with_scope(self.element, |data, scope| {
741            let map = data.relative_invalidation_map_attributes();
742            if !map.used {
743                return;
744            }
745            gather_dependencies(
746                &self.element,
747                scope.map(|e| e.opaque()),
748                data,
749                self.quirks_mode,
750                &mut collector,
751            );
752        });
753        if collector.is_empty() {
754            return;
755        }
756        self.invalidate_from_dependencies(collector.get());
757    }
758
759    /// Gather relative selector dependencies for the given element (And its subtree) that mutated, and invalidate as necessary.
760    #[inline(never)]
761    pub fn invalidate_relative_selectors_for_dom_mutation(
762        self,
763        subtree: bool,
764        stylist: &'a Stylist,
765        inherited_search_path: ElementSelectorFlags,
766        operation: DomMutationOperation,
767    ) {
768        let mut collector = RelativeSelectorDependencyCollector::new(
769            self.element,
770            if operation.is_side_effect() {
771                None
772            } else {
773                Some(OptimizationContext {
774                    sibling_traversal_map: &self.sibling_traversal_map,
775                    quirks_mode: self.quirks_mode,
776                    operation,
777                })
778            },
779        );
780        let mut traverse_subtree = false;
781        self.element.apply_selector_flags(inherited_search_path);
782        stylist.for_each_cascade_data_with_scope(self.element, |data, scope| {
783            let map_attributes = data.relative_invalidation_map_attributes();
784            if !map_attributes.used {
785                return;
786            }
787            let map = data.relative_selector_invalidation_map();
788            traverse_subtree |= map_attributes.needs_ancestors_traversal;
789            collector.collect_all_dependencies_for_element(
790                self.element,
791                scope.map(|e| e.opaque()),
792                self.quirks_mode,
793                map,
794                map_attributes,
795                operation,
796            );
797        });
798
799        if subtree && traverse_subtree {
800            for node in self.element.as_node().dom_descendants() {
801                let descendant = match node.as_element() {
802                    Some(e) => e,
803                    None => continue,
804                };
805                descendant.apply_selector_flags(inherited_search_path);
806                stylist.for_each_cascade_data_with_scope(descendant, |data, scope| {
807                    let map_attributes = data.relative_invalidation_map_attributes();
808                    if !map_attributes.used {
809                        return;
810                    }
811                    let map = data.relative_selector_invalidation_map();
812                    collector.collect_all_dependencies_for_element(
813                        descendant,
814                        scope.map(|e| e.opaque()),
815                        self.quirks_mode,
816                        map,
817                        map_attributes,
818                        operation,
819                    );
820                });
821            }
822        }
823        if collector.is_empty() {
824            return;
825        }
826        self.invalidate_from_dependencies(collector.get());
827    }
828
829    /// Carry out complete invalidation triggered by a relative selector invalidation.
830    fn invalidate_from_dependencies(&self, to_invalidate: ToInvalidate<'a, E>) {
831        for (element, dependencies) in to_invalidate.dependencies {
832            let mut selector_caches = SelectorCaches::default();
833            let mut processor = RelativeSelectorInnerInvalidationProcessor::new(
834                self.quirks_mode,
835                self.snapshot_table,
836                &dependencies,
837                &mut selector_caches,
838                &self.sibling_traversal_map,
839            );
840            TreeStyleInvalidator::new(element, None, &mut processor).invalidate();
841            for (element, invalidation) in processor.take_invalidations() {
842                self.invalidate_upwards(element, &invalidation);
843            }
844        }
845        for invalidation in to_invalidate.invalidations {
846            self.invalidate_upwards(self.element, &invalidation);
847        }
848    }
849
850    fn invalidate_upwards(&self, element: E, invalidation: &RelativeSelectorInvalidation<'a>) {
851        // This contains the main reason for why relative selector invalidation is handled
852        // separately - It travels ancestor and/or earlier sibling direction.
853        match invalidation.kind {
854            RelativeDependencyInvalidationKind::Parent => {
855                element.parent_element().map(|e| {
856                    if !Self::in_search_direction(
857                        &e,
858                        ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_ANCESTOR,
859                    ) {
860                        return;
861                    }
862                    self.handle_anchor(e, invalidation.dependency, invalidation.host);
863                });
864            },
865            RelativeDependencyInvalidationKind::Ancestors => {
866                let mut parent = element.parent_element();
867                while let Some(par) = parent {
868                    if !Self::in_search_direction(
869                        &par,
870                        ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_ANCESTOR,
871                    ) {
872                        return;
873                    }
874                    self.handle_anchor(par, invalidation.dependency, invalidation.host);
875                    parent = par.parent_element();
876                }
877            },
878            RelativeDependencyInvalidationKind::PrevSibling => {
879                self.sibling_traversal_map
880                    .prev_sibling_for(&element)
881                    .map(|e| {
882                        if !Self::in_search_direction(
883                            &e,
884                            ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_SIBLING,
885                        ) {
886                            return;
887                        }
888                        self.handle_anchor(e, invalidation.dependency, invalidation.host);
889                    });
890            },
891            RelativeDependencyInvalidationKind::AncestorPrevSibling => {
892                let mut parent = element.parent_element();
893                while let Some(par) = parent {
894                    if !Self::in_search_direction(
895                        &par,
896                        ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_ANCESTOR,
897                    ) {
898                        return;
899                    }
900                    par.prev_sibling_element().map(|e| {
901                        if !Self::in_search_direction(
902                            &e,
903                            ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_SIBLING,
904                        ) {
905                            return;
906                        }
907                        self.handle_anchor(e, invalidation.dependency, invalidation.host);
908                    });
909                    parent = par.parent_element();
910                }
911            },
912            RelativeDependencyInvalidationKind::EarlierSibling => {
913                let mut sibling = self.sibling_traversal_map.prev_sibling_for(&element);
914                while let Some(sib) = sibling {
915                    if !Self::in_search_direction(
916                        &sib,
917                        ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_SIBLING,
918                    ) {
919                        return;
920                    }
921                    self.handle_anchor(sib, invalidation.dependency, invalidation.host);
922                    sibling = sib.prev_sibling_element();
923                }
924            },
925            RelativeDependencyInvalidationKind::AncestorEarlierSibling => {
926                let mut parent = element.parent_element();
927                while let Some(par) = parent {
928                    if !Self::in_search_direction(
929                        &par,
930                        ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_ANCESTOR,
931                    ) {
932                        return;
933                    }
934                    let mut sibling = par.prev_sibling_element();
935                    while let Some(sib) = sibling {
936                        if !Self::in_search_direction(
937                            &sib,
938                            ElementSelectorFlags::RELATIVE_SELECTOR_SEARCH_DIRECTION_SIBLING,
939                        ) {
940                            return;
941                        }
942                        self.handle_anchor(sib, invalidation.dependency, invalidation.host);
943                        sibling = sib.prev_sibling_element();
944                    }
945                    parent = par.parent_element();
946                }
947            },
948        }
949    }
950
951    /// Is this element in the direction of the given relative selector search path?
952    fn in_search_direction(element: &E, desired: ElementSelectorFlags) -> bool {
953        element
954            .relative_selector_search_direction()
955            .intersects(desired)
956    }
957
958    /// Handle a potential relative selector anchor.
959    fn handle_anchor(
960        &self,
961        element: E,
962        outer_dependency: &Dependency,
963        host: Option<OpaqueElement>,
964    ) {
965        let is_rightmost = Self::is_subject(outer_dependency);
966        if (is_rightmost
967            && !element.has_selector_flags(ElementSelectorFlags::ANCHORS_RELATIVE_SELECTOR))
968            || (!is_rightmost
969                && !element.has_selector_flags(
970                    ElementSelectorFlags::ANCHORS_RELATIVE_SELECTOR_NON_SUBJECT,
971                ))
972        {
973            // If it was never a relative selector anchor, don't bother.
974            return;
975        }
976        let mut selector_caches = SelectorCaches::default();
977        let matching_context = MatchingContext::<'_, E::Impl>::new_for_visited(
978            MatchingMode::Normal,
979            None,
980            &mut selector_caches,
981            VisitedHandlingMode::AllLinksVisitedAndUnvisited,
982            IncludeStartingStyle::No,
983            self.quirks_mode,
984            NeedsSelectorFlags::No,
985            MatchingForInvalidation::Yes,
986        );
987        let mut data = match element.mutate_data() {
988            Some(data) => data,
989            None => return,
990        };
991        let mut processor = RelativeSelectorOuterInvalidationProcessor {
992            element,
993            host,
994            data: data.deref_mut(),
995            dependency: &*outer_dependency,
996            matching_context,
997            traversal_map: &self.sibling_traversal_map,
998        };
999        let result = TreeStyleInvalidator::new(element, None, &mut processor).invalidate();
1000        (self.invalidated)(element, &result);
1001    }
1002
1003    /// Does this relative selector dependency have its relative selector in the subject position?
1004    fn is_subject(outer_dependency: &Dependency) -> bool {
1005        debug_assert!(
1006            matches!(
1007                outer_dependency.invalidation_kind(),
1008                DependencyInvalidationKind::Normal(_) | DependencyInvalidationKind::Scope(_)
1009            ),
1010            "Outer selector of relative selector is relative?"
1011        );
1012
1013        if let Some(x) = outer_dependency.next.as_ref() {
1014            // We only care to ensure that we're the subject in the outermost selector of the current
1015            // selector - Crossing over a scope invalidation would mean moving into a selector inside
1016            // the current scope block
1017            if matches!(
1018                outer_dependency.invalidation_kind(),
1019                DependencyInvalidationKind::Normal(..)
1020            ) {
1021                if !Self::is_subject(&x.as_ref().slice()[0]) {
1022                    // Not subject in outer selector.
1023                    return false;
1024                }
1025            }
1026        }
1027        outer_dependency
1028            .selector
1029            .is_rightmost(outer_dependency.selector_offset)
1030    }
1031}
1032
1033/// Blindly invalidate everything outside of a relative selector.
1034/// Consider `:is(.a :has(.b) .c ~ .d) ~ .e .f`, where .b gets deleted.
1035/// Since the tree mutated, we cannot rely on snapshots.
1036pub struct RelativeSelectorOuterInvalidationProcessor<'a, 'b, E: TElement> {
1037    /// Element being invalidated.
1038    pub element: E,
1039    /// The current shadow host, if any.
1040    pub host: Option<OpaqueElement>,
1041    /// Data for the element being invalidated.
1042    pub data: &'a mut ElementData,
1043    /// Dependency to be processed.
1044    pub dependency: &'b Dependency,
1045    /// Matching context to use for invalidation.
1046    pub matching_context: MatchingContext<'a, E::Impl>,
1047    /// Traversal map for this invalidation.
1048    pub traversal_map: &'a SiblingTraversalMap<E>,
1049}
1050
1051impl<'a, 'b: 'a, E: 'a> InvalidationProcessor<'b, 'a, E>
1052    for RelativeSelectorOuterInvalidationProcessor<'a, 'b, E>
1053where
1054    E: TElement,
1055{
1056    fn invalidates_on_pseudo_element(&self) -> bool {
1057        true
1058    }
1059
1060    fn check_outer_dependency(
1061        &mut self,
1062        _dependency: &Dependency,
1063        _element: E,
1064        _: Option<OpaqueElement>,
1065    ) -> bool {
1066        // At this point, we know a relative selector invalidated, and are ignoring them.
1067        true
1068    }
1069
1070    fn matching_context(&mut self) -> &mut MatchingContext<'a, E::Impl> {
1071        &mut self.matching_context
1072    }
1073
1074    fn sibling_traversal_map(&self) -> &SiblingTraversalMap<E> {
1075        self.traversal_map
1076    }
1077
1078    fn collect_invalidations(
1079        &mut self,
1080        element: E,
1081        _self_invalidations: &mut InvalidationVector<'b>,
1082        descendant_invalidations: &mut DescendantInvalidationLists<'b>,
1083        sibling_invalidations: &mut InvalidationVector<'b>,
1084    ) -> bool {
1085        debug_assert_eq!(element, self.element);
1086        debug_assert!(
1087            self.matching_context.matching_for_invalidation(),
1088            "Not matching for invalidation?"
1089        );
1090
1091        // Ok, this element can potentially an anchor to the given dependency.
1092        // Before we do the potentially-costly ancestor/earlier sibling traversal,
1093        // See if it can actuall be an anchor by trying to match the "rest" of the selector
1094        // outside and to the left of `:has` in question.
1095        // e.g. Element under consideration can only be the anchor to `:has` in
1096        // `.foo .bar ~ .baz:has()`, iff it matches `.foo .bar ~ .baz`.
1097        let invalidated_self = {
1098            let mut invalidated = false;
1099            let mut dependencies_to_invalidate: SmallVec<[&Dependency; 1]> =
1100                smallvec![self.dependency];
1101            while let Some(d) = dependencies_to_invalidate.pop() {
1102                debug_assert!(
1103                    matches!(
1104                        d.invalidation_kind(),
1105                        DependencyInvalidationKind::Normal(_)
1106                            | DependencyInvalidationKind::Scope(_)
1107                    ),
1108                    "Unexpected dependency kind"
1109                );
1110                if !dependency_may_be_relevant(d, &element, false) {
1111                    continue;
1112                }
1113                if !matches_selector(
1114                    &d.selector,
1115                    d.selector_offset,
1116                    None,
1117                    &element,
1118                    self.matching_context(),
1119                ) {
1120                    continue;
1121                }
1122
1123                let invalidation_kind = d.invalidation_kind();
1124
1125                if let DependencyInvalidationKind::Scope(scope_kind) = invalidation_kind {
1126                    if d.selector.is_rightmost(d.selector_offset) {
1127                        if scope_kind == ScopeDependencyInvalidationKind::ScopeEnd {
1128                            let invalidations = note_scope_dependency_force_at_subject(
1129                                d,
1130                                self.matching_context.current_host.clone(),
1131                                self.matching_context.scope_element,
1132                                false,
1133                            );
1134                            descendant_invalidations
1135                                .dom_descendants
1136                                .extend(invalidations);
1137
1138                            invalidated |= true;
1139                        } else if let Some(ref next) = d.next {
1140                            dependencies_to_invalidate.extend(next.as_ref().slice());
1141                        }
1142                        continue;
1143                    }
1144                }
1145
1146                if matches!(
1147                    invalidation_kind,
1148                    DependencyInvalidationKind::Normal(NormalDependencyInvalidationKind::Element)
1149                ) {
1150                    if let Some(ref deps) = d.next {
1151                        // Normal dependencies should only have one next
1152                        dependencies_to_invalidate.push(&deps.as_ref().slice()[0]);
1153                        continue;
1154                    }
1155                    invalidated |= true;
1156                    continue;
1157                }
1158                debug_assert_ne!(d.selector_offset, 0);
1159                debug_assert_ne!(d.selector_offset, d.selector.len());
1160                let invalidation = Invalidation::new(&d, self.host, None);
1161                invalidated |= push_invalidation(
1162                    invalidation,
1163                    d.invalidation_kind(),
1164                    descendant_invalidations,
1165                    sibling_invalidations,
1166                );
1167            }
1168            invalidated
1169        };
1170
1171        if invalidated_self {
1172            self.data.hint.insert(RestyleHint::RESTYLE_SELF);
1173        }
1174        invalidated_self
1175    }
1176
1177    fn should_process_descendants(&mut self, element: E) -> bool {
1178        if element == self.element {
1179            return should_process_descendants(&self.data);
1180        }
1181
1182        match element.borrow_data() {
1183            Some(d) => should_process_descendants(&d),
1184            None => return false,
1185        }
1186    }
1187
1188    fn recursion_limit_exceeded(&mut self, _element: E) {
1189        unreachable!("Unexpected recursion limit");
1190    }
1191
1192    fn invalidated_descendants(&mut self, element: E, child: E) {
1193        invalidated_descendants(element, child)
1194    }
1195
1196    fn invalidated_self(&mut self, element: E) {
1197        debug_assert_ne!(element, self.element);
1198        invalidated_self(element);
1199    }
1200
1201    fn invalidated_sibling(&mut self, element: E, of: E) {
1202        debug_assert_ne!(element, self.element);
1203        invalidated_sibling(element, of);
1204    }
1205}
1206
1207/// Invalidation for the selector(s) inside a relative selector.
1208pub struct RelativeSelectorInnerInvalidationProcessor<'a, 'b, 'c, E>
1209where
1210    E: TElement + 'a,
1211{
1212    /// Matching context to be used.
1213    matching_context: MatchingContext<'b, E::Impl>,
1214    /// Table of snapshots.
1215    snapshot_table: Option<&'c ServoElementSnapshotTable>,
1216    /// Incoming dependencies to be processed.
1217    dependencies: &'c ElementDependencies<'a>,
1218    /// Generated invalidations.
1219    invalidations: InnerInvalidations<'a, E>,
1220    /// Traversal map for this invalidation.
1221    traversal_map: &'b SiblingTraversalMap<E>,
1222}
1223
1224impl<'a, 'b, 'c, E> RelativeSelectorInnerInvalidationProcessor<'a, 'b, 'c, E>
1225where
1226    E: TElement + 'a,
1227{
1228    fn new(
1229        quirks_mode: QuirksMode,
1230        snapshot_table: Option<&'c ServoElementSnapshotTable>,
1231        dependencies: &'c ElementDependencies<'a>,
1232        selector_caches: &'b mut SelectorCaches,
1233        traversal_map: &'b SiblingTraversalMap<E>,
1234    ) -> Self {
1235        let matching_context = MatchingContext::new_for_visited(
1236            MatchingMode::Normal,
1237            None,
1238            selector_caches,
1239            VisitedHandlingMode::AllLinksVisitedAndUnvisited,
1240            IncludeStartingStyle::No,
1241            quirks_mode,
1242            NeedsSelectorFlags::No,
1243            MatchingForInvalidation::Yes,
1244        );
1245        Self {
1246            matching_context,
1247            snapshot_table,
1248            dependencies,
1249            invalidations: InnerInvalidations::default(),
1250            traversal_map,
1251        }
1252    }
1253
1254    fn note_dependency(
1255        &mut self,
1256        element: E,
1257        host: Option<OpaqueElement>,
1258        dependency: &'a Dependency,
1259        descendant_invalidations: &mut DescendantInvalidationLists<'a>,
1260        sibling_invalidations: &mut InvalidationVector<'a>,
1261    ) {
1262        match dependency.invalidation_kind() {
1263            DependencyInvalidationKind::FullSelector => unreachable!(),
1264            DependencyInvalidationKind::Normal(_) | DependencyInvalidationKind::Scope(_) => (),
1265            DependencyInvalidationKind::Relative(kind) => {
1266                self.found_relative_selector_invalidation(element, kind, dependency);
1267                return;
1268            },
1269        }
1270        if matches!(
1271            dependency.normal_invalidation_kind(),
1272            NormalDependencyInvalidationKind::Element
1273        ) {
1274            // Ok, keep heading outwards.
1275            debug_assert!(
1276                dependency.next.is_some(),
1277                "Orphaned inner selector dependency?"
1278            );
1279            if let Some(next) = dependency.next.as_ref() {
1280                self.note_dependency(
1281                    element,
1282                    host,
1283                    &next.as_ref().slice()[0],
1284                    descendant_invalidations,
1285                    sibling_invalidations,
1286                );
1287            }
1288            return;
1289        }
1290        let invalidation = Invalidation::new(&dependency, None, None);
1291        match dependency.normal_invalidation_kind() {
1292            NormalDependencyInvalidationKind::Descendants => {
1293                // Descendant invalidations are simplified due to pseudo-elements not being available within the relative selector.
1294                descendant_invalidations.dom_descendants.push(invalidation)
1295            },
1296            NormalDependencyInvalidationKind::Siblings => sibling_invalidations.push(invalidation),
1297            // Note(dshin, bug 1940212): Nesting can enabling stuffing pseudo-elements into :has, like `::marker { :has(&) }`.
1298            // Ideally, we can just not insert the dependency into the invalidation map, but the necessary selector information
1299            // for this (i.e. `HAS_PSEUDO`) is filtered out in `replace_parent_selector` through
1300            // `SelectorFlags::forbidden_for_nesting`, so just ignoring such dependencies here is the best we can do.
1301            _ => (),
1302        }
1303    }
1304
1305    /// Take the generated invalidations.
1306    fn take_invalidations(self) -> InnerInvalidations<'a, E> {
1307        self.invalidations
1308    }
1309}
1310
1311impl<'a, 'b, 'c, E> InvalidationProcessor<'a, 'b, E>
1312    for RelativeSelectorInnerInvalidationProcessor<'a, 'b, 'c, E>
1313where
1314    E: TElement + 'a,
1315{
1316    fn check_outer_dependency(
1317        &mut self,
1318        dependency: &Dependency,
1319        element: E,
1320        _: Option<OpaqueElement>,
1321    ) -> bool {
1322        if let Some(snapshot_table) = self.snapshot_table {
1323            let wrapper = ElementWrapper::new(element, snapshot_table);
1324            return check_dependency(
1325                dependency,
1326                &element,
1327                &wrapper,
1328                &mut self.matching_context,
1329                None,
1330            );
1331        }
1332        // Just invalidate if we don't have a snapshot.
1333        true
1334    }
1335
1336    fn matching_context(&mut self) -> &mut MatchingContext<'b, E::Impl> {
1337        return &mut self.matching_context;
1338    }
1339
1340    fn collect_invalidations(
1341        &mut self,
1342        element: E,
1343        _self_invalidations: &mut InvalidationVector<'a>,
1344        descendant_invalidations: &mut DescendantInvalidationLists<'a>,
1345        sibling_invalidations: &mut InvalidationVector<'a>,
1346    ) -> bool {
1347        for (scope, dependency) in self.dependencies {
1348            self.note_dependency(
1349                element,
1350                *scope,
1351                dependency,
1352                descendant_invalidations,
1353                sibling_invalidations,
1354            )
1355        }
1356        false
1357    }
1358
1359    fn should_process_descendants(&mut self, _element: E) -> bool {
1360        true
1361    }
1362
1363    fn recursion_limit_exceeded(&mut self, _element: E) {
1364        unreachable!("Unexpected recursion limit");
1365    }
1366
1367    // Don't do anything for normal invalidations.
1368    fn invalidated_self(&mut self, _element: E) {}
1369    fn invalidated_sibling(&mut self, _sibling: E, _of: E) {}
1370    fn invalidated_descendants(&mut self, _element: E, _child: E) {}
1371
1372    fn found_relative_selector_invalidation(
1373        &mut self,
1374        element: E,
1375        kind: RelativeDependencyInvalidationKind,
1376        dep: &'a Dependency,
1377    ) {
1378        debug_assert!(dep.next.is_some(), "Orphaned inners selector?");
1379        if element.relative_selector_search_direction().is_empty() {
1380            return;
1381        }
1382        self.invalidations.push((
1383            element,
1384            RelativeSelectorInvalidation {
1385                host: self.matching_context.current_host,
1386                kind,
1387                dependency: &dep.next.as_ref().unwrap().as_ref().slice()[0],
1388            },
1389        ));
1390    }
1391
1392    fn sibling_traversal_map(&self) -> &SiblingTraversalMap<E> {
1393        &self.traversal_map
1394    }
1395}
style/invalidation/element/relative_selector.rs

style/invalidation/element/
relative_selector.rs
