diff options
Diffstat (limited to 'servo/components/style/stylesheets/rule_parser.rs')
| -rw-r--r-- | servo/components/style/stylesheets/rule_parser.rs | 879 |
1 files changed, 879 insertions, 0 deletions
diff --git a/servo/components/style/stylesheets/rule_parser.rs b/servo/components/style/stylesheets/rule_parser.rs new file mode 100644 index 0000000000..de95c898fd --- /dev/null +++ b/servo/components/style/stylesheets/rule_parser.rs @@ -0,0 +1,879 @@ +/* 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::custom_properties::parse_name as parse_custom_property_name; +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::declaration_block::{ + parse_property_declaration_list, DeclarationParserState, PropertyDeclarationBlock, +}; +use crate::properties_and_values::rule::{parse_property_block, PropertyRuleName}; +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, ImportRule, ImportSupportsCondition}; +use crate::stylesheets::keyframes_rule::parse_keyframe_list; +use crate::stylesheets::layer_rule::{LayerBlockRule, LayerName, LayerStatementRule}; +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::{Atom, Namespace, Prefix}; +use cssparser::{ + AtRuleParser, BasicParseError, BasicParseErrorKind, CowRcStr, DeclarationParser, Parser, + ParserState, QualifiedRuleParser, RuleBodyItemParser, RuleBodyParser, SourceLocation, + 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, 'i> { + /// 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. + 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 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, + /// Parser state for declaration blocks in either nested rules or style rules. + pub declaration_parser_state: DeclarationParserState<'i>, + /// The rules we've parsed so far. + pub rules: Vec<CssRule>, +} + +impl<'a, 'i> TopLevelRuleParser<'a, 'i> { + fn nested<'b>(&'b mut self) -> NestedRuleParser<'b, 'a, 'i> { + NestedRuleParser { + shared_lock: self.shared_lock, + context: &mut self.context, + declaration_parser_state: &mut self.declaration_parser_state, + rules: &mut self.rules, + } + } + + /// 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 @property rule prelude. + Property(PropertyRuleName), + /// A @document rule, with its conditional. + Document(DocumentCondition), + /// A @import rule prelude. + Import( + CssUrl, + Arc<Locked<MediaList>>, + Option<ImportSupportsCondition>, + ImportLayer, + ), + /// A @namespace rule prelude. + Namespace(Option<Prefix>, Namespace), + /// A @layer rule prelude. + Layer(Vec<LayerName>), +} + +impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a, 'i> { + type Prelude = AtRulePrelude; + type AtRule = SourcePosition; + 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, supports) = ImportRule::parse_layer_and_supports(input, &mut self.context); + + let media = MediaList::parse(&self.context, input); + let media = Arc::new(self.shared_lock.wrap(media)); + + return Ok(AtRulePrelude::Import(url, media, supports, 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)); + } + AtRuleParser::parse_block(&mut self.nested(), prelude, start, input)?; + self.state = State::Body; + Ok(start.position()) + } + + #[inline] + fn rule_without_block( + &mut self, + prelude: AtRulePrelude, + start: &ParserState, + ) -> Result<Self::AtRule, ()> { + match prelude { + AtRulePrelude::Import(url, media, supports, 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, + supports, + layer, + ); + + self.state = State::Imports; + self.rules.push(CssRule::Import(import_rule)) + }, + AtRulePrelude::Namespace(prefix, url) => { + let namespaces = self.context.namespaces.to_mut(); + let prefix = if let Some(prefix) = prefix { + namespaces.prefixes.insert(prefix.clone(), url.clone()); + Some(prefix) + } else { + namespaces.default = Some(url.clone()); + None + }; + + self.state = State::Namespaces; + self.rules.push(CssRule::Namespace(Arc::new(NamespaceRule { + prefix, + url, + source_location: start.source_location(), + }))); + }, + AtRulePrelude::Layer(..) => { + AtRuleParser::rule_without_block(&mut self.nested(), prelude, start)?; + if self.state <= State::EarlyLayers { + self.state = State::EarlyLayers; + } else { + self.state = State::Body; + } + }, + _ => AtRuleParser::rule_without_block(&mut self.nested(), prelude, start)?, + }; + + Ok(start.position()) + } +} + +impl<'a, 'i> QualifiedRuleParser<'i> for TopLevelRuleParser<'a, 'i> { + type Prelude = SelectorList<SelectorImpl>; + type QualifiedRule = SourcePosition; + 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>> { + QualifiedRuleParser::parse_block(&mut self.nested(), prelude, start, input)?; + self.state = State::Body; + Ok(start.position()) + } +} + +struct NestedRuleParser<'a, 'b: 'a, 'i> { + shared_lock: &'a SharedRwLock, + context: &'a mut ParserContext<'b>, + declaration_parser_state: &'a mut DeclarationParserState<'i>, + rules: &'a mut Vec<CssRule>, +} + +struct NestedParseResult { + rules: Vec<CssRule>, + declarations: PropertyDeclarationBlock, +} + +impl NestedParseResult { + fn into_rules( + mut self, + shared_lock: &SharedRwLock, + source_location: SourceLocation, + ) -> Arc<Locked<CssRules>> { + lazy_static! { + static ref AMPERSAND: SelectorList<SelectorImpl> = { + let list = SelectorList::ampersand(); + list.0 + .iter() + .for_each(|selector| selector.mark_as_intentionally_leaked()); + list + }; + }; + + if !self.declarations.is_empty() { + self.rules.insert( + 0, + CssRule::Style(Arc::new(shared_lock.wrap(StyleRule { + selectors: AMPERSAND.clone(), + block: Arc::new(shared_lock.wrap(self.declarations)), + rules: None, + source_location, + }))), + ) + } + + CssRules::new(self.rules, shared_lock) + } +} + +impl<'a, 'b, 'i> NestedRuleParser<'a, 'b, 'i> { + /// When nesting is disabled, we prevent parsing at rules and qualified rules inside style + /// rules. + fn allow_at_and_qualified_rules(&self) -> bool { + if !self.context.rule_types.contains(CssRuleType::Style) { + return true; + } + static_prefs::pref!("layout.css.nesting.enabled") + } + + fn nest_for_rule<R>(&mut self, rule_type: CssRuleType, cb: impl FnOnce(&mut Self) -> R) -> R { + let old_rule_types = self.context.rule_types; + self.context.rule_types.insert(rule_type); + let r = cb(self); + self.context.rule_types = old_rule_types; + r + } + + fn parse_nested( + &mut self, + input: &mut Parser<'i, '_>, + rule_type: CssRuleType, + selectors: Option<&SelectorList<SelectorImpl>>, + ) -> NestedParseResult { + self.nest_for_rule(rule_type, |parser| { + let parse_declarations = parser.parse_declarations(); + let mut old_declaration_state = std::mem::take(parser.declaration_parser_state); + let mut rules = std::mem::take(parser.rules); + let mut iter = RuleBodyParser::new(input, parser); + while let Some(result) = iter.next() { + match result { + Ok(()) => {}, + Err((error, slice)) => { + if parse_declarations { + iter.parser.declaration_parser_state.did_error( + iter.parser.context, + error, + slice, + ); + } else { + let location = error.location; + let error = ContextualParseError::InvalidRule(slice, error); + iter.parser.context.log_css_error(location, error); + } + }, + } + } + let declarations = if parse_declarations { + parser + .declaration_parser_state + .report_errors_if_needed(parser.context, selectors); + parser.declaration_parser_state.take_declarations() + } else { + PropertyDeclarationBlock::default() + }; + debug_assert!( + !parser.declaration_parser_state.has_parsed_declarations(), + "Parsed but didn't consume declarations" + ); + std::mem::swap(parser.declaration_parser_state, &mut old_declaration_state); + std::mem::swap(parser.rules, &mut rules); + NestedParseResult { + rules, + declarations, + } + }) + } +} + +impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b, 'i> { + type Prelude = AtRulePrelude; + type AtRule = (); + type Error = StyleParseErrorKind<'i>; + + fn parse_prelude<'t>( + &mut self, + name: CowRcStr<'i>, + input: &mut Parser<'i, 't>, + ) -> Result<Self::Prelude, ParseError<'i>> { + if !self.allow_at_and_qualified_rules() { + return Err(input.new_error(BasicParseErrorKind::AtRuleInvalid(name))); + } + 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" => { + 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_error(BasicParseErrorKind::AtRuleInvalid(name.clone()))) + } + let name = KeyframesName::parse(self.context, input)?; + AtRulePrelude::Keyframes(name, prefix) + }, + "page" if cfg!(feature = "gecko") => { + AtRulePrelude::Page( + input.try_parse(|i| PageSelectors::parse(self.context, i)).unwrap_or_default() + ) + }, + "property" if static_prefs::pref!("layout.css.properties-and-values.enabled") => { + let name = input.expect_ident_cloned()?; + let name = parse_custom_property_name(&name).map_err(|_| { + input.new_custom_error(StyleParseErrorKind::UnexpectedIdent(name.clone())) + })?; + AtRulePrelude::Property(PropertyRuleName(Arc::new(Atom::from(name)))) + }, + "-moz-document" if cfg!(feature = "gecko") => { + let cond = DocumentCondition::parse(self.context, input)?; + AtRulePrelude::Document(cond) + }, + _ => return Err(input.new_error(BasicParseErrorKind::AtRuleInvalid(name.clone()))) + }) + } + + fn parse_block<'t>( + &mut self, + prelude: AtRulePrelude, + start: &ParserState, + input: &mut Parser<'i, 't>, + ) -> Result<(), ParseError<'i>> { + let rule = match prelude { + AtRulePrelude::FontFace => self.nest_for_rule(CssRuleType::FontFace, |p| { + CssRule::FontFace(Arc::new(p.shared_lock.wrap( + parse_font_face_block(&p.context, input, start.source_location()).into(), + ))) + }), + AtRulePrelude::FontFeatureValues(family_names) => { + self.nest_for_rule(CssRuleType::FontFeatureValues, |p| { + CssRule::FontFeatureValues(Arc::new(FontFeatureValuesRule::parse( + &p.context, + input, + family_names, + start.source_location(), + ))) + }) + }, + AtRulePrelude::FontPaletteValues(name) => { + self.nest_for_rule(CssRuleType::FontPaletteValues, |p| { + CssRule::FontPaletteValues(Arc::new(FontPaletteValuesRule::parse( + &p.context, + input, + name, + start.source_location(), + ))) + }) + }, + AtRulePrelude::CounterStyle(name) => { + let body = self.nest_for_rule(CssRuleType::CounterStyle, |p| { + parse_counter_style_body(name, &p.context, input, start.source_location()) + })?; + CssRule::CounterStyle(Arc::new(self.shared_lock.wrap(body))) + }, + AtRulePrelude::Media(media_queries) => { + let source_location = start.source_location(); + CssRule::Media(Arc::new(MediaRule { + media_queries, + rules: self + .parse_nested(input, CssRuleType::Media, None) + .into_rules(self.shared_lock, source_location), + source_location, + })) + }, + AtRulePrelude::Supports(condition) => { + let enabled = + self.nest_for_rule(CssRuleType::Style, |p| condition.eval(&p.context)); + let source_location = start.source_location(); + CssRule::Supports(Arc::new(SupportsRule { + condition, + rules: self + .parse_nested(input, CssRuleType::Supports, None) + .into_rules(self.shared_lock, source_location), + enabled, + source_location, + })) + }, + AtRulePrelude::Viewport => { + let body = self.nest_for_rule(CssRuleType::Viewport, |p| { + ViewportRule::parse(&p.context, input) + })?; + CssRule::Viewport(Arc::new(body)) + }, + AtRulePrelude::Keyframes(name, vendor_prefix) => { + self.nest_for_rule(CssRuleType::Keyframe, |p| { + CssRule::Keyframes(Arc::new(p.shared_lock.wrap(KeyframesRule { + name, + keyframes: parse_keyframe_list(&mut p.context, input, p.shared_lock), + vendor_prefix, + source_location: start.source_location(), + }))) + }) + }, + AtRulePrelude::Page(selectors) => { + let declarations = self.nest_for_rule(CssRuleType::Page, |p| { + // TODO: Support nesting in @page rules? + parse_property_declaration_list(&p.context, input, None) + }); + CssRule::Page(Arc::new(self.shared_lock.wrap(PageRule { + selectors, + block: Arc::new(self.shared_lock.wrap(declarations)), + source_location: start.source_location(), + }))) + }, + AtRulePrelude::Property(name) => self.nest_for_rule(CssRuleType::Property, |p| { + CssRule::Property(Arc::new(parse_property_block( + &p.context, + input, + name, + start.source_location(), + ))) + }), + AtRulePrelude::Document(condition) => { + if !cfg!(feature = "gecko") { + unreachable!() + } + let source_location = start.source_location(); + CssRule::Document(Arc::new(DocumentRule { + condition, + rules: self + .parse_nested(input, CssRuleType::Document, None) + .into_rules(self.shared_lock, source_location), + source_location, + })) + }, + AtRulePrelude::Container(condition) => { + let source_location = start.source_location(); + CssRule::Container(Arc::new(ContainerRule { + condition, + rules: self + .parse_nested(input, CssRuleType::Container, None) + .into_rules(self.shared_lock, source_location), + source_location, + })) + }, + AtRulePrelude::Layer(names) => { + let name = match names.len() { + 0 | 1 => names.into_iter().next(), + _ => return Err(input.new_error(BasicParseErrorKind::AtRuleBodyInvalid)), + }; + let source_location = start.source_location(); + CssRule::LayerBlock(Arc::new(LayerBlockRule { + name, + rules: self + .parse_nested(input, CssRuleType::LayerBlock, None) + .into_rules(self.shared_lock, source_location), + source_location, + })) + }, + AtRulePrelude::Import(..) | AtRulePrelude::Namespace(..) => { + // These rules don't have blocks. + return Err(input.new_unexpected_token_error(cssparser::Token::CurlyBracketBlock)); + }, + }; + self.rules.push(rule); + Ok(()) + } + + #[inline] + fn rule_without_block( + &mut self, + prelude: AtRulePrelude, + start: &ParserState, + ) -> Result<(), ()> { + let rule = match prelude { + AtRulePrelude::Layer(names) => { + if names.is_empty() { + return Err(()); + } + CssRule::LayerStatement(Arc::new(LayerStatementRule { + names, + source_location: start.source_location(), + })) + }, + _ => return Err(()), + }; + self.rules.push(rule); + Ok(()) + } +} + +#[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, 'i> { + type Prelude = SelectorList<SelectorImpl>; + type QualifiedRule = (); + 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.context.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<(), ParseError<'i>> { + let result = self.parse_nested(input, CssRuleType::Style, Some(&selectors)); + let block = Arc::new(self.shared_lock.wrap(result.declarations)); + self.rules + .push(CssRule::Style(Arc::new(self.shared_lock.wrap(StyleRule { + selectors, + block, + rules: if result.rules.is_empty() { + None + } else { + Some(CssRules::new(result.rules, self.shared_lock)) + }, + source_location: start.source_location(), + })))); + Ok(()) + } +} + +impl<'a, 'b, 'i> DeclarationParser<'i> for NestedRuleParser<'a, 'b, 'i> { + type Declaration = (); + type Error = StyleParseErrorKind<'i>; + fn parse_value<'t>( + &mut self, + name: CowRcStr<'i>, + input: &mut Parser<'i, 't>, + ) -> Result<(), ParseError<'i>> { + self.declaration_parser_state + .parse_value(self.context, name, input) + } +} + +impl<'a, 'b, 'i> RuleBodyItemParser<'i, (), StyleParseErrorKind<'i>> + for NestedRuleParser<'a, 'b, 'i> +{ + fn parse_qualified(&self) -> bool { + self.allow_at_and_qualified_rules() + } + + /// If nesting is disabled, we can't get there for a non-style-rule. If it's enabled, we parse + /// raw declarations there. + fn parse_declarations(&self) -> bool { + self.context.rule_types.contains(CssRuleType::Style) + } +} |