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-rw-r--r--servo/components/style/stylesheets/rule_parser.rs796
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diff --git a/servo/components/style/stylesheets/rule_parser.rs b/servo/components/style/stylesheets/rule_parser.rs
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Parsing of the stylesheet contents.
+
+use crate::counter_style::{parse_counter_style_body, parse_counter_style_name_definition};
+use crate::error_reporting::ContextualParseError;
+use crate::font_face::parse_font_face_block;
+use crate::media_queries::MediaList;
+use crate::parser::{Parse, ParserContext};
+use crate::properties::parse_property_declaration_list;
+use crate::selector_parser::{SelectorImpl, SelectorParser};
+use crate::shared_lock::{Locked, SharedRwLock};
+use crate::str::starts_with_ignore_ascii_case;
+use crate::stylesheets::container_rule::{ContainerCondition, ContainerRule};
+use crate::stylesheets::document_rule::DocumentCondition;
+use crate::stylesheets::font_feature_values_rule::parse_family_name_list;
+use crate::stylesheets::import_rule::ImportLayer;
+use crate::stylesheets::keyframes_rule::parse_keyframe_list;
+use crate::stylesheets::layer_rule::{LayerBlockRule, LayerName, LayerStatementRule};
+use crate::stylesheets::stylesheet::Namespaces;
+use crate::stylesheets::supports_rule::SupportsCondition;
+use crate::stylesheets::{
+ viewport_rule, AllowImportRules, CorsMode, CssRule, CssRuleType, CssRules, DocumentRule,
+ FontFeatureValuesRule, FontPaletteValuesRule, KeyframesRule, MediaRule, NamespaceRule,
+ PageRule, PageSelectors, RulesMutateError, StyleRule, StylesheetLoader, SupportsRule,
+ ViewportRule,
+};
+use crate::values::computed::font::FamilyName;
+use crate::values::{CssUrl, CustomIdent, DashedIdent, KeyframesName};
+use crate::{Namespace, Prefix};
+use cssparser::{
+ AtRuleParser, BasicParseError, BasicParseErrorKind, CowRcStr, Parser, ParserState,
+ QualifiedRuleParser, RuleListParser, SourcePosition,
+};
+use selectors::SelectorList;
+use servo_arc::Arc;
+use style_traits::{ParseError, StyleParseErrorKind};
+
+/// The information we need particularly to do CSSOM insertRule stuff.
+pub struct InsertRuleContext<'a> {
+ /// The rule list we're about to insert into.
+ pub rule_list: &'a [CssRule],
+ /// The index we're about to get inserted at.
+ pub index: usize,
+}
+
+impl<'a> InsertRuleContext<'a> {
+ /// Returns the max rule state allowable for insertion at a given index in
+ /// the rule list.
+ pub fn max_rule_state_at_index(&self, index: usize) -> State {
+ let rule = match self.rule_list.get(index) {
+ Some(rule) => rule,
+ None => return State::Body,
+ };
+ match rule {
+ CssRule::Import(..) => State::Imports,
+ CssRule::Namespace(..) => State::Namespaces,
+ CssRule::LayerStatement(..) => {
+ // If there are @import / @namespace after this layer, then
+ // we're in the early-layers phase, otherwise we're in the body
+ // and everything is fair game.
+ let next_non_layer_statement_rule = self.rule_list[index + 1..]
+ .iter()
+ .find(|r| !matches!(*r, CssRule::LayerStatement(..)));
+ if let Some(non_layer) = next_non_layer_statement_rule {
+ if matches!(*non_layer, CssRule::Import(..) | CssRule::Namespace(..)) {
+ return State::EarlyLayers;
+ }
+ }
+ State::Body
+ },
+ _ => State::Body,
+ }
+ }
+}
+
+/// The parser for the top-level rules in a stylesheet.
+pub struct TopLevelRuleParser<'a> {
+ /// A reference to the lock we need to use to create rules.
+ pub shared_lock: &'a SharedRwLock,
+ /// A reference to a stylesheet loader if applicable, for `@import` rules.
+ pub loader: Option<&'a dyn StylesheetLoader>,
+ /// The top-level parser context.
+ ///
+ /// This won't contain any namespaces, and only nested parsers created with
+ /// `ParserContext::new_with_rule_type` will.
+ pub context: ParserContext<'a>,
+ /// The current state of the parser.
+ pub state: State,
+ /// Whether we have tried to parse was invalid due to being in the wrong
+ /// place (e.g. an @import rule was found while in the `Body` state). Reset
+ /// to `false` when `take_had_hierarchy_error` is called.
+ pub dom_error: Option<RulesMutateError>,
+ /// The namespace map we use for parsing. Needs to start as `Some()`, and
+ /// will be taken out after parsing namespace rules, and that reference will
+ /// be moved to `ParserContext`.
+ pub namespaces: &'a mut Namespaces,
+ /// The info we need insert a rule in a list.
+ pub insert_rule_context: Option<InsertRuleContext<'a>>,
+ /// Whether @import rules will be allowed.
+ pub allow_import_rules: AllowImportRules,
+}
+
+impl<'b> TopLevelRuleParser<'b> {
+ fn nested<'a: 'b>(&'a self) -> NestedRuleParser<'a, 'b> {
+ NestedRuleParser {
+ shared_lock: self.shared_lock,
+ context: &self.context,
+ namespaces: &self.namespaces,
+ }
+ }
+
+ /// Returns the current state of the parser.
+ pub fn state(&self) -> State {
+ self.state
+ }
+
+ /// Checks whether we can parse a rule that would transition us to
+ /// `new_state`.
+ ///
+ /// This is usually a simple branch, but we may need more bookkeeping if
+ /// doing `insertRule` from CSSOM.
+ fn check_state(&mut self, new_state: State) -> bool {
+ if self.state > new_state {
+ self.dom_error = Some(RulesMutateError::HierarchyRequest);
+ return false;
+ }
+
+ let ctx = match self.insert_rule_context {
+ Some(ref ctx) => ctx,
+ None => return true,
+ };
+
+ let max_rule_state = ctx.max_rule_state_at_index(ctx.index);
+ if new_state > max_rule_state {
+ self.dom_error = Some(RulesMutateError::HierarchyRequest);
+ return false;
+ }
+
+ // If there's anything that isn't a namespace rule (or import rule, but
+ // we checked that already at the beginning), reject with a
+ // StateError.
+ if new_state == State::Namespaces &&
+ ctx.rule_list[ctx.index..]
+ .iter()
+ .any(|r| !matches!(*r, CssRule::Namespace(..)))
+ {
+ self.dom_error = Some(RulesMutateError::InvalidState);
+ return false;
+ }
+
+ true
+ }
+}
+
+/// The current state of the parser.
+#[derive(Clone, Copy, Eq, Ord, PartialEq, PartialOrd)]
+pub enum State {
+ /// We haven't started parsing rules.
+ Start = 1,
+ /// We're parsing early `@layer` statement rules.
+ EarlyLayers = 2,
+ /// We're parsing `@import` and early `@layer` statement rules.
+ Imports = 3,
+ /// We're parsing `@namespace` rules.
+ Namespaces = 4,
+ /// We're parsing the main body of the stylesheet.
+ Body = 5,
+}
+
+#[derive(Clone, Debug, MallocSizeOf, ToShmem)]
+/// Vendor prefix.
+pub enum VendorPrefix {
+ /// -moz prefix.
+ Moz,
+ /// -webkit prefix.
+ WebKit,
+}
+
+/// A rule prelude for at-rule with block.
+pub enum AtRulePrelude {
+ /// A @font-face rule prelude.
+ FontFace,
+ /// A @font-feature-values rule prelude, with its FamilyName list.
+ FontFeatureValues(Vec<FamilyName>),
+ /// A @font-palette-values rule prelude, with its identifier.
+ FontPaletteValues(DashedIdent),
+ /// A @counter-style rule prelude, with its counter style name.
+ CounterStyle(CustomIdent),
+ /// A @media rule prelude, with its media queries.
+ Media(Arc<Locked<MediaList>>),
+ /// A @container rule prelude.
+ Container(Arc<ContainerCondition>),
+ /// An @supports rule, with its conditional
+ Supports(SupportsCondition),
+ /// A @viewport rule prelude.
+ Viewport,
+ /// A @keyframes rule, with its animation name and vendor prefix if exists.
+ Keyframes(KeyframesName, Option<VendorPrefix>),
+ /// A @page rule prelude, with its page name if it exists.
+ Page(PageSelectors),
+ /// A @document rule, with its conditional.
+ Document(DocumentCondition),
+ /// A @import rule prelude.
+ Import(CssUrl, Arc<Locked<MediaList>>, Option<ImportLayer>),
+ /// A @namespace rule prelude.
+ Namespace(Option<Prefix>, Namespace),
+ /// A @layer rule prelude.
+ Layer(Vec<LayerName>),
+}
+
+impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
+ type Prelude = AtRulePrelude;
+ type AtRule = (SourcePosition, CssRule);
+ type Error = StyleParseErrorKind<'i>;
+
+ fn parse_prelude<'t>(
+ &mut self,
+ name: CowRcStr<'i>,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<AtRulePrelude, ParseError<'i>> {
+ match_ignore_ascii_case! { &*name,
+ "import" => {
+ if !self.check_state(State::Imports) {
+ return Err(input.new_custom_error(StyleParseErrorKind::UnexpectedImportRule))
+ }
+
+ if let AllowImportRules::No = self.allow_import_rules {
+ return Err(input.new_custom_error(StyleParseErrorKind::DisallowedImportRule))
+ }
+
+ // FIXME(emilio): We should always be able to have a loader
+ // around! See bug 1533783.
+ if self.loader.is_none() {
+ error!("Saw @import rule, but no way to trigger the load");
+ return Err(input.new_custom_error(StyleParseErrorKind::UnexpectedImportRule))
+ }
+
+ let url_string = input.expect_url_or_string()?.as_ref().to_owned();
+ let url = CssUrl::parse_from_string(url_string, &self.context, CorsMode::None);
+
+ let layer = if !static_prefs::pref!("layout.css.cascade-layers.enabled") {
+ None
+ } else if input.try_parse(|input| input.expect_ident_matching("layer")).is_ok() {
+ Some(ImportLayer {
+ name: None,
+ })
+ } else {
+ input.try_parse(|input| {
+ input.expect_function_matching("layer")?;
+ input.parse_nested_block(|input| {
+ LayerName::parse(&self.context, input)
+ }).map(|name| ImportLayer {
+ name: Some(name),
+ })
+ }).ok()
+ };
+
+ let media = MediaList::parse(&self.context, input);
+ let media = Arc::new(self.shared_lock.wrap(media));
+
+ return Ok(AtRulePrelude::Import(url, media, layer));
+ },
+ "namespace" => {
+ if !self.check_state(State::Namespaces) {
+ return Err(input.new_custom_error(StyleParseErrorKind::UnexpectedNamespaceRule))
+ }
+
+ let prefix = input.try_parse(|i| i.expect_ident_cloned())
+ .map(|s| Prefix::from(s.as_ref())).ok();
+ let maybe_namespace = match input.expect_url_or_string() {
+ Ok(url_or_string) => url_or_string,
+ Err(BasicParseError { kind: BasicParseErrorKind::UnexpectedToken(t), location }) => {
+ return Err(location.new_custom_error(StyleParseErrorKind::UnexpectedTokenWithinNamespace(t)))
+ }
+ Err(e) => return Err(e.into()),
+ };
+ let url = Namespace::from(maybe_namespace.as_ref());
+ return Ok(AtRulePrelude::Namespace(prefix, url));
+ },
+ // @charset is removed by rust-cssparser if it’s the first rule in the stylesheet
+ // anything left is invalid.
+ "charset" => {
+ self.dom_error = Some(RulesMutateError::HierarchyRequest);
+ return Err(input.new_custom_error(StyleParseErrorKind::UnexpectedCharsetRule))
+ },
+ "layer" => {
+ let state_to_check = if self.state <= State::EarlyLayers {
+ // The real state depends on whether there's a block or not.
+ // We don't know that yet, but the parse_block check deals
+ // with that.
+ State::EarlyLayers
+ } else {
+ State::Body
+ };
+ if !self.check_state(state_to_check) {
+ return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
+ }
+ },
+ _ => {
+ // All other rules have blocks, so we do this check early in
+ // parse_block instead.
+ }
+ }
+
+ AtRuleParser::parse_prelude(&mut self.nested(), name, input)
+ }
+
+ #[inline]
+ fn parse_block<'t>(
+ &mut self,
+ prelude: AtRulePrelude,
+ start: &ParserState,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<Self::AtRule, ParseError<'i>> {
+ if !self.check_state(State::Body) {
+ return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
+ }
+ let rule = AtRuleParser::parse_block(&mut self.nested(), prelude, start, input)?;
+ self.state = State::Body;
+ Ok((start.position(), rule))
+ }
+
+ #[inline]
+ fn rule_without_block(
+ &mut self,
+ prelude: AtRulePrelude,
+ start: &ParserState,
+ ) -> Result<Self::AtRule, ()> {
+ let rule = match prelude {
+ AtRulePrelude::Import(url, media, layer) => {
+ let loader = self
+ .loader
+ .expect("Expected a stylesheet loader for @import");
+
+ let import_rule = loader.request_stylesheet(
+ url,
+ start.source_location(),
+ &self.context,
+ &self.shared_lock,
+ media,
+ layer,
+ );
+
+ self.state = State::Imports;
+ CssRule::Import(import_rule)
+ },
+ AtRulePrelude::Namespace(prefix, url) => {
+ let prefix = if let Some(prefix) = prefix {
+ self.namespaces.prefixes.insert(prefix.clone(), url.clone());
+ Some(prefix)
+ } else {
+ self.namespaces.default = Some(url.clone());
+ None
+ };
+
+ self.state = State::Namespaces;
+ CssRule::Namespace(Arc::new(self.shared_lock.wrap(NamespaceRule {
+ prefix,
+ url,
+ source_location: start.source_location(),
+ })))
+ },
+ AtRulePrelude::Layer(ref names) => {
+ if names.is_empty() {
+ return Err(());
+ }
+ if self.state <= State::EarlyLayers {
+ self.state = State::EarlyLayers;
+ } else {
+ self.state = State::Body;
+ }
+ AtRuleParser::rule_without_block(&mut self.nested(), prelude, start)
+ .expect("All validity checks on the nested parser should be done before changing self.state")
+ },
+ _ => AtRuleParser::rule_without_block(&mut self.nested(), prelude, start)?,
+ };
+
+ Ok((start.position(), rule))
+ }
+}
+
+impl<'a, 'i> QualifiedRuleParser<'i> for TopLevelRuleParser<'a> {
+ type Prelude = SelectorList<SelectorImpl>;
+ type QualifiedRule = (SourcePosition, CssRule);
+ type Error = StyleParseErrorKind<'i>;
+
+ #[inline]
+ fn parse_prelude<'t>(
+ &mut self,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<Self::Prelude, ParseError<'i>> {
+ if !self.check_state(State::Body) {
+ return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
+ }
+
+ QualifiedRuleParser::parse_prelude(&mut self.nested(), input)
+ }
+
+ #[inline]
+ fn parse_block<'t>(
+ &mut self,
+ prelude: Self::Prelude,
+ start: &ParserState,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<Self::QualifiedRule, ParseError<'i>> {
+ let rule = QualifiedRuleParser::parse_block(&mut self.nested(), prelude, start, input)?;
+ self.state = State::Body;
+ Ok((start.position(), rule))
+ }
+}
+
+#[derive(Clone)] // shallow, relatively cheap .clone
+struct NestedRuleParser<'a, 'b: 'a> {
+ shared_lock: &'a SharedRwLock,
+ context: &'a ParserContext<'b>,
+ namespaces: &'a Namespaces,
+}
+
+impl<'a, 'b> NestedRuleParser<'a, 'b> {
+ fn parse_nested_rules(
+ &mut self,
+ input: &mut Parser,
+ rule_type: CssRuleType,
+ ) -> Arc<Locked<CssRules>> {
+ let context = ParserContext::new_with_rule_type(self.context, rule_type, self.namespaces);
+
+ let nested_parser = NestedRuleParser {
+ shared_lock: self.shared_lock,
+ context: &context,
+ namespaces: self.namespaces,
+ };
+
+ let mut iter = RuleListParser::new_for_nested_rule(input, nested_parser);
+ let mut rules = Vec::new();
+ while let Some(result) = iter.next() {
+ match result {
+ Ok(rule) => rules.push(rule),
+ Err((error, slice)) => {
+ let location = error.location;
+ let error = ContextualParseError::InvalidRule(slice, error);
+ self.context.log_css_error(location, error);
+ },
+ }
+ }
+ CssRules::new(rules, self.shared_lock)
+ }
+}
+
+impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
+ type Prelude = AtRulePrelude;
+ type AtRule = CssRule;
+ type Error = StyleParseErrorKind<'i>;
+
+ fn parse_prelude<'t>(
+ &mut self,
+ name: CowRcStr<'i>,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<Self::Prelude, ParseError<'i>> {
+ Ok(match_ignore_ascii_case! { &*name,
+ "media" => {
+ let media_queries = MediaList::parse(self.context, input);
+ let arc = Arc::new(self.shared_lock.wrap(media_queries));
+ AtRulePrelude::Media(arc)
+ },
+ "supports" => {
+ let cond = SupportsCondition::parse(input)?;
+ AtRulePrelude::Supports(cond)
+ },
+ "font-face" => {
+ AtRulePrelude::FontFace
+ },
+ "container" if static_prefs::pref!("layout.css.container-queries.enabled") => {
+ let condition = Arc::new(ContainerCondition::parse(self.context, input)?);
+ AtRulePrelude::Container(condition)
+ },
+ "layer" if static_prefs::pref!("layout.css.cascade-layers.enabled") => {
+ let names = input.try_parse(|input| {
+ input.parse_comma_separated(|input| {
+ LayerName::parse(self.context, input)
+ })
+ }).unwrap_or_default();
+ AtRulePrelude::Layer(names)
+ },
+ "font-feature-values" if cfg!(feature = "gecko") => {
+ let family_names = parse_family_name_list(self.context, input)?;
+ AtRulePrelude::FontFeatureValues(family_names)
+ },
+ "font-palette-values" if static_prefs::pref!("layout.css.font-palette.enabled") => {
+ let name = DashedIdent::parse(self.context, input)?;
+ AtRulePrelude::FontPaletteValues(name)
+ },
+ "counter-style" if cfg!(feature = "gecko") => {
+ let name = parse_counter_style_name_definition(input)?;
+ AtRulePrelude::CounterStyle(name)
+ },
+ "viewport" if viewport_rule::enabled() => {
+ AtRulePrelude::Viewport
+ },
+ "keyframes" | "-webkit-keyframes" | "-moz-keyframes" => {
+ let prefix = if starts_with_ignore_ascii_case(&*name, "-webkit-") {
+ Some(VendorPrefix::WebKit)
+ } else if starts_with_ignore_ascii_case(&*name, "-moz-") {
+ Some(VendorPrefix::Moz)
+ } else {
+ None
+ };
+ if cfg!(feature = "servo") &&
+ prefix.as_ref().map_or(false, |p| matches!(*p, VendorPrefix::Moz)) {
+ // Servo should not support @-moz-keyframes.
+ return Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
+ }
+ let name = KeyframesName::parse(self.context, input)?;
+ AtRulePrelude::Keyframes(name, prefix)
+ },
+ "page" if cfg!(feature = "gecko") => {
+ AtRulePrelude::Page(if static_prefs::pref!("layout.css.named-pages.enabled") {
+ input.try_parse(|i| PageSelectors::parse(self.context, i)).unwrap_or_default()
+ } else {
+ PageSelectors::default()
+ })
+ },
+ "-moz-document" if cfg!(feature = "gecko") => {
+ let cond = DocumentCondition::parse(self.context, input)?;
+ AtRulePrelude::Document(cond)
+ },
+ _ => return Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
+ })
+ }
+
+ fn parse_block<'t>(
+ &mut self,
+ prelude: AtRulePrelude,
+ start: &ParserState,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<CssRule, ParseError<'i>> {
+ match prelude {
+ AtRulePrelude::FontFace => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::FontFace,
+ self.namespaces,
+ );
+
+ Ok(CssRule::FontFace(Arc::new(self.shared_lock.wrap(
+ parse_font_face_block(&context, input, start.source_location()).into(),
+ ))))
+ },
+ AtRulePrelude::FontFeatureValues(family_names) => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::FontFeatureValues,
+ self.namespaces,
+ );
+
+ Ok(CssRule::FontFeatureValues(Arc::new(self.shared_lock.wrap(
+ FontFeatureValuesRule::parse(
+ &context,
+ input,
+ family_names,
+ start.source_location(),
+ ),
+ ))))
+ },
+ AtRulePrelude::FontPaletteValues(name) => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::FontPaletteValues,
+ self.namespaces,
+ );
+
+ Ok(CssRule::FontPaletteValues(Arc::new(self.shared_lock.wrap(
+ FontPaletteValuesRule::parse(
+ &context,
+ input,
+ name,
+ start.source_location(),
+ ),
+ ))))
+ },
+ AtRulePrelude::CounterStyle(name) => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::CounterStyle,
+ self.namespaces,
+ );
+
+ Ok(CssRule::CounterStyle(Arc::new(
+ self.shared_lock.wrap(
+ parse_counter_style_body(name, &context, input, start.source_location())?
+ .into(),
+ ),
+ )))
+ },
+ AtRulePrelude::Media(media_queries) => {
+ Ok(CssRule::Media(Arc::new(self.shared_lock.wrap(MediaRule {
+ media_queries,
+ rules: self.parse_nested_rules(input, CssRuleType::Media),
+ source_location: start.source_location(),
+ }))))
+ },
+ AtRulePrelude::Supports(condition) => {
+ let eval_context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::Style,
+ self.namespaces,
+ );
+
+ let enabled = condition.eval(&eval_context, self.namespaces);
+ Ok(CssRule::Supports(Arc::new(self.shared_lock.wrap(
+ SupportsRule {
+ condition,
+ rules: self.parse_nested_rules(input, CssRuleType::Supports),
+ enabled,
+ source_location: start.source_location(),
+ },
+ ))))
+ },
+ AtRulePrelude::Viewport => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::Viewport,
+ self.namespaces,
+ );
+
+ Ok(CssRule::Viewport(Arc::new(
+ self.shared_lock.wrap(ViewportRule::parse(&context, input)?),
+ )))
+ },
+ AtRulePrelude::Keyframes(name, vendor_prefix) => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::Keyframes,
+ self.namespaces,
+ );
+
+ Ok(CssRule::Keyframes(Arc::new(self.shared_lock.wrap(
+ KeyframesRule {
+ name,
+ keyframes: parse_keyframe_list(&context, input, self.shared_lock),
+ vendor_prefix,
+ source_location: start.source_location(),
+ },
+ ))))
+ },
+ AtRulePrelude::Page(selectors) => {
+ let context = ParserContext::new_with_rule_type(
+ self.context,
+ CssRuleType::Page,
+ self.namespaces,
+ );
+
+ let declarations = parse_property_declaration_list(&context, input, None);
+ Ok(CssRule::Page(Arc::new(self.shared_lock.wrap(PageRule {
+ selectors,
+ block: Arc::new(self.shared_lock.wrap(declarations)),
+ source_location: start.source_location(),
+ }))))
+ },
+ AtRulePrelude::Document(condition) => {
+ if !cfg!(feature = "gecko") {
+ unreachable!()
+ }
+ Ok(CssRule::Document(Arc::new(self.shared_lock.wrap(
+ DocumentRule {
+ condition,
+ rules: self.parse_nested_rules(input, CssRuleType::Document),
+ source_location: start.source_location(),
+ },
+ ))))
+ },
+ AtRulePrelude::Container(condition) => Ok(CssRule::Container(Arc::new(
+ self.shared_lock.wrap(ContainerRule {
+ condition,
+ rules: self.parse_nested_rules(input, CssRuleType::Container),
+ source_location: start.source_location(),
+ }),
+ ))),
+ AtRulePrelude::Layer(names) => {
+ let name = match names.len() {
+ 0 | 1 => names.into_iter().next(),
+ _ => return Err(input.new_error(BasicParseErrorKind::AtRuleBodyInvalid)),
+ };
+ Ok(CssRule::LayerBlock(Arc::new(self.shared_lock.wrap(
+ LayerBlockRule {
+ name,
+ rules: self.parse_nested_rules(input, CssRuleType::LayerBlock),
+ source_location: start.source_location(),
+ },
+ ))))
+ },
+ AtRulePrelude::Import(..) | AtRulePrelude::Namespace(..) => {
+ // These rules don't have blocks.
+ Err(input.new_unexpected_token_error(cssparser::Token::CurlyBracketBlock))
+ },
+ }
+ }
+
+ #[inline]
+ fn rule_without_block(
+ &mut self,
+ prelude: AtRulePrelude,
+ start: &ParserState,
+ ) -> Result<Self::AtRule, ()> {
+ Ok(match prelude {
+ AtRulePrelude::Layer(names) => {
+ if names.is_empty() {
+ return Err(());
+ }
+ CssRule::LayerStatement(Arc::new(self.shared_lock.wrap(LayerStatementRule {
+ names,
+ source_location: start.source_location(),
+ })))
+ },
+ _ => return Err(()),
+ })
+ }
+}
+
+#[inline(never)]
+fn check_for_useless_selector(
+ input: &mut Parser,
+ context: &ParserContext,
+ selectors: &SelectorList<SelectorImpl>,
+) {
+ use cssparser::ToCss;
+
+ 'selector_loop: for selector in selectors.0.iter() {
+ let mut current = selector.iter();
+ loop {
+ let mut found_host = false;
+ let mut found_non_host = false;
+ for component in &mut current {
+ if component.is_host() {
+ found_host = true;
+ } else {
+ found_non_host = true;
+ }
+ if found_host && found_non_host {
+ let location = input.current_source_location();
+ context.log_css_error(
+ location,
+ ContextualParseError::NeverMatchingHostSelector(selector.to_css_string()),
+ );
+ continue 'selector_loop;
+ }
+ }
+ if current.next_sequence().is_none() {
+ break;
+ }
+ }
+ }
+}
+
+impl<'a, 'b, 'i> QualifiedRuleParser<'i> for NestedRuleParser<'a, 'b> {
+ type Prelude = SelectorList<SelectorImpl>;
+ type QualifiedRule = CssRule;
+ type Error = StyleParseErrorKind<'i>;
+
+ fn parse_prelude<'t>(
+ &mut self,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<Self::Prelude, ParseError<'i>> {
+ let selector_parser = SelectorParser {
+ stylesheet_origin: self.context.stylesheet_origin,
+ namespaces: self.namespaces,
+ url_data: self.context.url_data,
+ for_supports_rule: false,
+ };
+ let selectors = SelectorList::parse(&selector_parser, input)?;
+ if self.context.error_reporting_enabled() {
+ check_for_useless_selector(input, &self.context, &selectors);
+ }
+ Ok(selectors)
+ }
+
+ fn parse_block<'t>(
+ &mut self,
+ selectors: Self::Prelude,
+ start: &ParserState,
+ input: &mut Parser<'i, 't>,
+ ) -> Result<CssRule, ParseError<'i>> {
+ let context =
+ ParserContext::new_with_rule_type(self.context, CssRuleType::Style, self.namespaces);
+
+ let declarations = parse_property_declaration_list(&context, input, Some(&selectors));
+ let block = Arc::new(self.shared_lock.wrap(declarations));
+ Ok(CssRule::Style(Arc::new(self.shared_lock.wrap(StyleRule {
+ selectors,
+ block,
+ source_location: start.source_location(),
+ }))))
+ }
+}