Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 595 insertions, 0 deletions

diff --git a/servo/components/style/stylesheets/stylesheet.rs b/servo/components/style/stylesheets/stylesheet.rs
new file mode 100644
index 0000000000..097cf7f393
--- /dev/null
+++ b/servo/components/style/stylesheets/stylesheet.rs
@@ -0,0 +1,595 @@
+/* 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/. */
+
+use crate::context::QuirksMode;
+use crate::error_reporting::{ContextualParseError, ParseErrorReporter};
+use crate::media_queries::{Device, MediaList};
+use crate::parser::ParserContext;
+use crate::shared_lock::{DeepCloneParams, DeepCloneWithLock, Locked};
+use crate::shared_lock::{SharedRwLock, SharedRwLockReadGuard};
+use crate::stylesheets::loader::StylesheetLoader;
+use crate::stylesheets::rule_parser::{State, TopLevelRuleParser};
+use crate::stylesheets::rules_iterator::{EffectiveRules, EffectiveRulesIterator};
+use crate::stylesheets::rules_iterator::{NestedRuleIterationCondition, RulesIterator};
+use crate::stylesheets::{CssRule, CssRules, Origin, UrlExtraData};
+use crate::use_counters::UseCounters;
+use crate::{Namespace, Prefix};
+use cssparser::{Parser, ParserInput, StyleSheetParser};
+use fxhash::FxHashMap;
+#[cfg(feature = "gecko")]
+use malloc_size_of::{MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
+use parking_lot::RwLock;
+use servo_arc::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use style_traits::ParsingMode;
+
+/// This structure holds the user-agent and user stylesheets.
+pub struct UserAgentStylesheets {
+    /// The lock used for user-agent stylesheets.
+    pub shared_lock: SharedRwLock,
+    /// The user or user agent stylesheets.
+    pub user_or_user_agent_stylesheets: Vec<DocumentStyleSheet>,
+    /// The quirks mode stylesheet.
+    pub quirks_mode_stylesheet: DocumentStyleSheet,
+}
+
+/// A set of namespaces applying to a given stylesheet.
+///
+/// The namespace id is used in gecko
+#[derive(Clone, Debug, Default, MallocSizeOf)]
+#[allow(missing_docs)]
+pub struct Namespaces {
+    pub default: Option<Namespace>,
+    pub prefixes: FxHashMap<Prefix, Namespace>,
+}
+
+/// The contents of a given stylesheet. This effectively maps to a
+/// StyleSheetInner in Gecko.
+#[derive(Debug)]
+pub struct StylesheetContents {
+    /// List of rules in the order they were found (important for
+    /// cascading order)
+    pub rules: Arc<Locked<CssRules>>,
+    /// The origin of this stylesheet.
+    pub origin: Origin,
+    /// The url data this stylesheet should use.
+    pub url_data: RwLock<UrlExtraData>,
+    /// The namespaces that apply to this stylesheet.
+    pub namespaces: RwLock<Namespaces>,
+    /// The quirks mode of this stylesheet.
+    pub quirks_mode: QuirksMode,
+    /// This stylesheet's source map URL.
+    pub source_map_url: RwLock<Option<String>>,
+    /// This stylesheet's source URL.
+    pub source_url: RwLock<Option<String>>,
+
+    /// We don't want to allow construction outside of this file, to guarantee
+    /// that all contents are created with Arc<>.
+    _forbid_construction: (),
+}
+
+impl StylesheetContents {
+    /// Parse a given CSS string, with a given url-data, origin, and
+    /// quirks mode.
+    pub fn from_str(
+        css: &str,
+        url_data: UrlExtraData,
+        origin: Origin,
+        shared_lock: &SharedRwLock,
+        stylesheet_loader: Option<&dyn StylesheetLoader>,
+        error_reporter: Option<&dyn ParseErrorReporter>,
+        quirks_mode: QuirksMode,
+        line_number_offset: u32,
+        use_counters: Option<&UseCounters>,
+        allow_import_rules: AllowImportRules,
+        sanitization_data: Option<&mut SanitizationData>,
+    ) -> Arc<Self> {
+        let (namespaces, rules, source_map_url, source_url) = Stylesheet::parse_rules(
+            css,
+            &url_data,
+            origin,
+            &shared_lock,
+            stylesheet_loader,
+            error_reporter,
+            quirks_mode,
+            line_number_offset,
+            use_counters,
+            allow_import_rules,
+            sanitization_data,
+        );
+
+        Arc::new(Self {
+            rules: CssRules::new(rules, &shared_lock),
+            origin,
+            url_data: RwLock::new(url_data),
+            namespaces: RwLock::new(namespaces),
+            quirks_mode,
+            source_map_url: RwLock::new(source_map_url),
+            source_url: RwLock::new(source_url),
+            _forbid_construction: (),
+        })
+    }
+
+    /// Creates a new StylesheetContents with the specified pre-parsed rules,
+    /// origin, URL data, and quirks mode.
+    ///
+    /// Since the rules have already been parsed, and the intention is that
+    /// this function is used for read only User Agent style sheets, an empty
+    /// namespace map is used, and the source map and source URLs are set to
+    /// None.
+    ///
+    /// An empty namespace map should be fine, as it is only used for parsing,
+    /// not serialization of existing selectors.  Since UA sheets are read only,
+    /// we should never need the namespace map.
+    pub fn from_shared_data(
+        rules: Arc<Locked<CssRules>>,
+        origin: Origin,
+        url_data: UrlExtraData,
+        quirks_mode: QuirksMode,
+    ) -> Arc<Self> {
+        debug_assert!(rules.is_static());
+        Arc::new(Self {
+            rules,
+            origin,
+            url_data: RwLock::new(url_data),
+            namespaces: RwLock::new(Namespaces::default()),
+            quirks_mode,
+            source_map_url: RwLock::new(None),
+            source_url: RwLock::new(None),
+            _forbid_construction: (),
+        })
+    }
+
+    /// Returns a reference to the list of rules.
+    #[inline]
+    pub fn rules<'a, 'b: 'a>(&'a self, guard: &'b SharedRwLockReadGuard) -> &'a [CssRule] {
+        &self.rules.read_with(guard).0
+    }
+
+    /// Measure heap usage.
+    #[cfg(feature = "gecko")]
+    pub fn size_of(&self, guard: &SharedRwLockReadGuard, ops: &mut MallocSizeOfOps) -> usize {
+        if self.rules.is_static() {
+            return 0;
+        }
+        // Measurement of other fields may be added later.
+        self.rules.unconditional_shallow_size_of(ops) +
+            self.rules.read_with(guard).size_of(guard, ops)
+    }
+}
+
+impl DeepCloneWithLock for StylesheetContents {
+    fn deep_clone_with_lock(
+        &self,
+        lock: &SharedRwLock,
+        guard: &SharedRwLockReadGuard,
+        params: &DeepCloneParams,
+    ) -> Self {
+        // Make a deep clone of the rules, using the new lock.
+        let rules = self
+            .rules
+            .read_with(guard)
+            .deep_clone_with_lock(lock, guard, params);
+
+        Self {
+            rules: Arc::new(lock.wrap(rules)),
+            quirks_mode: self.quirks_mode,
+            origin: self.origin,
+            url_data: RwLock::new((*self.url_data.read()).clone()),
+            namespaces: RwLock::new((*self.namespaces.read()).clone()),
+            source_map_url: RwLock::new((*self.source_map_url.read()).clone()),
+            source_url: RwLock::new((*self.source_url.read()).clone()),
+            _forbid_construction: (),
+        }
+    }
+}
+
+/// The structure servo uses to represent a stylesheet.
+#[derive(Debug)]
+pub struct Stylesheet {
+    /// The contents of this stylesheet.
+    pub contents: Arc<StylesheetContents>,
+    /// The lock used for objects inside this stylesheet
+    pub shared_lock: SharedRwLock,
+    /// List of media associated with the Stylesheet.
+    pub media: Arc<Locked<MediaList>>,
+    /// Whether this stylesheet should be disabled.
+    pub disabled: AtomicBool,
+}
+
+macro_rules! rule_filter {
+    ($( $method: ident($variant:ident => $rule_type: ident), )+) => {
+        $(
+            #[allow(missing_docs)]
+            fn $method<F>(&self, device: &Device, guard: &SharedRwLockReadGuard, mut f: F)
+                where F: FnMut(&crate::stylesheets::$rule_type),
+            {
+                use crate::stylesheets::CssRule;
+
+                for rule in self.effective_rules(device, guard) {
+                    if let CssRule::$variant(ref rule) = *rule {
+                        f(&rule)
+                    }
+                }
+            }
+        )+
+    }
+}
+
+/// A trait to represent a given stylesheet in a document.
+pub trait StylesheetInDocument: ::std::fmt::Debug {
+    /// Get whether this stylesheet is enabled.
+    fn enabled(&self) -> bool;
+
+    /// Get the media associated with this stylesheet.
+    fn media<'a>(&'a self, guard: &'a SharedRwLockReadGuard) -> Option<&'a MediaList>;
+
+    /// Returns a reference to the list of rules in this stylesheet.
+    fn rules<'a, 'b: 'a>(&'a self, guard: &'b SharedRwLockReadGuard) -> &'a [CssRule] {
+        self.contents().rules(guard)
+    }
+
+    /// Returns a reference to the contents of the stylesheet.
+    fn contents(&self) -> &StylesheetContents;
+
+    /// Return an iterator using the condition `C`.
+    #[inline]
+    fn iter_rules<'a, 'b, C>(
+        &'a self,
+        device: &'a Device,
+        guard: &'a SharedRwLockReadGuard<'b>,
+    ) -> RulesIterator<'a, 'b, C>
+    where
+        C: NestedRuleIterationCondition,
+    {
+        let contents = self.contents();
+        RulesIterator::new(
+            device,
+            contents.quirks_mode,
+            guard,
+            contents.rules(guard).iter(),
+        )
+    }
+
+    /// Returns whether the style-sheet applies for the current device.
+    fn is_effective_for_device(&self, device: &Device, guard: &SharedRwLockReadGuard) -> bool {
+        match self.media(guard) {
+            Some(medialist) => medialist.evaluate(device, self.contents().quirks_mode),
+            None => true,
+        }
+    }
+
+    /// Return an iterator over the effective rules within the style-sheet, as
+    /// according to the supplied `Device`.
+    #[inline]
+    fn effective_rules<'a, 'b>(
+        &'a self,
+        device: &'a Device,
+        guard: &'a SharedRwLockReadGuard<'b>,
+    ) -> EffectiveRulesIterator<'a, 'b> {
+        self.iter_rules::<EffectiveRules>(device, guard)
+    }
+
+    rule_filter! {
+        effective_viewport_rules(Viewport => ViewportRule),
+    }
+}
+
+impl StylesheetInDocument for Stylesheet {
+    fn media<'a>(&'a self, guard: &'a SharedRwLockReadGuard) -> Option<&'a MediaList> {
+        Some(self.media.read_with(guard))
+    }
+
+    fn enabled(&self) -> bool {
+        !self.disabled()
+    }
+
+    #[inline]
+    fn contents(&self) -> &StylesheetContents {
+        &self.contents
+    }
+}
+
+/// A simple wrapper over an `Arc<Stylesheet>`, with pointer comparison, and
+/// suitable for its use in a `StylesheetSet`.
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+pub struct DocumentStyleSheet(
+    #[cfg_attr(feature = "servo", ignore_malloc_size_of = "Arc")] pub Arc<Stylesheet>,
+);
+
+impl PartialEq for DocumentStyleSheet {
+    fn eq(&self, other: &Self) -> bool {
+        Arc::ptr_eq(&self.0, &other.0)
+    }
+}
+
+impl StylesheetInDocument for DocumentStyleSheet {
+    fn media<'a>(&'a self, guard: &'a SharedRwLockReadGuard) -> Option<&'a MediaList> {
+        self.0.media(guard)
+    }
+
+    fn enabled(&self) -> bool {
+        self.0.enabled()
+    }
+
+    #[inline]
+    fn contents(&self) -> &StylesheetContents {
+        self.0.contents()
+    }
+}
+
+/// The kind of sanitization to use when parsing a stylesheet.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum SanitizationKind {
+    /// Perform no sanitization.
+    None,
+    /// Allow only @font-face, style rules, and @namespace.
+    Standard,
+    /// Allow everything but conditional rules.
+    NoConditionalRules,
+}
+
+/// Whether @import rules are allowed.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum AllowImportRules {
+    /// @import rules will be parsed.
+    Yes,
+    /// @import rules will not be parsed.
+    No,
+}
+
+impl SanitizationKind {
+    fn allows(self, rule: &CssRule) -> bool {
+        debug_assert_ne!(self, SanitizationKind::None);
+        // NOTE(emilio): If this becomes more complex (not filtering just by
+        // top-level rules), we should thread all the data through nested rules
+        // and such. But this doesn't seem necessary at the moment.
+        let is_standard = matches!(self, SanitizationKind::Standard);
+        match *rule {
+            CssRule::Document(..) |
+            CssRule::Media(..) |
+            CssRule::Supports(..) |
+            CssRule::Import(..) |
+            CssRule::Container(..) |
+            // TODO(emilio): Perhaps Layer should not be always sanitized? But
+            // we sanitize @media and co, so this seems safer for now.
+            CssRule::LayerStatement(..) |
+            CssRule::LayerBlock(..) => false,
+
+            CssRule::FontFace(..) | CssRule::Namespace(..) | CssRule::Style(..) => true,
+
+            CssRule::Keyframes(..) |
+            CssRule::Page(..) |
+            CssRule::Property(..) |
+            CssRule::FontFeatureValues(..) |
+            CssRule::FontPaletteValues(..) |
+            CssRule::Viewport(..) |
+            CssRule::CounterStyle(..) => !is_standard,
+        }
+    }
+}
+
+/// A struct to hold the data relevant to style sheet sanitization.
+#[derive(Debug)]
+pub struct SanitizationData {
+    kind: SanitizationKind,
+    output: String,
+}
+
+impl SanitizationData {
+    /// Create a new input for sanitization.
+    #[inline]
+    pub fn new(kind: SanitizationKind) -> Option<Self> {
+        if matches!(kind, SanitizationKind::None) {
+            return None;
+        }
+        Some(Self {
+            kind,
+            output: String::new(),
+        })
+    }
+
+    /// Take the sanitized output.
+    #[inline]
+    pub fn take(self) -> String {
+        self.output
+    }
+}
+
+impl Stylesheet {
+    /// Updates an empty stylesheet from a given string of text.
+    pub fn update_from_str(
+        existing: &Stylesheet,
+        css: &str,
+        url_data: UrlExtraData,
+        stylesheet_loader: Option<&dyn StylesheetLoader>,
+        error_reporter: Option<&dyn ParseErrorReporter>,
+        line_number_offset: u32,
+        allow_import_rules: AllowImportRules,
+    ) {
+        // FIXME: Consider adding use counters to Servo?
+        let (namespaces, rules, source_map_url, source_url) = Self::parse_rules(
+            css,
+            &url_data,
+            existing.contents.origin,
+            &existing.shared_lock,
+            stylesheet_loader,
+            error_reporter,
+            existing.contents.quirks_mode,
+            line_number_offset,
+            /* use_counters = */ None,
+            allow_import_rules,
+            /* sanitization_data = */ None,
+        );
+
+        *existing.contents.url_data.write() = url_data;
+        *existing.contents.namespaces.write() = namespaces;
+
+        // Acquire the lock *after* parsing, to minimize the exclusive section.
+        let mut guard = existing.shared_lock.write();
+        *existing.contents.rules.write_with(&mut guard) = CssRules(rules);
+        *existing.contents.source_map_url.write() = source_map_url;
+        *existing.contents.source_url.write() = source_url;
+    }
+
+    fn parse_rules(
+        css: &str,
+        url_data: &UrlExtraData,
+        origin: Origin,
+        shared_lock: &SharedRwLock,
+        stylesheet_loader: Option<&dyn StylesheetLoader>,
+        error_reporter: Option<&dyn ParseErrorReporter>,
+        quirks_mode: QuirksMode,
+        line_number_offset: u32,
+        use_counters: Option<&UseCounters>,
+        allow_import_rules: AllowImportRules,
+        mut sanitization_data: Option<&mut SanitizationData>,
+    ) -> (Namespaces, Vec<CssRule>, Option<String>, Option<String>) {
+        let mut input = ParserInput::new_with_line_number_offset(css, line_number_offset);
+        let mut input = Parser::new(&mut input);
+
+        let context = ParserContext::new(
+            origin,
+            url_data,
+            None,
+            ParsingMode::DEFAULT,
+            quirks_mode,
+            /* namespaces = */ Default::default(),
+            error_reporter,
+            use_counters,
+        );
+
+        let mut rule_parser = TopLevelRuleParser {
+            shared_lock,
+            loader: stylesheet_loader,
+            context,
+            state: State::Start,
+            dom_error: None,
+            insert_rule_context: None,
+            allow_import_rules,
+            declaration_parser_state: Default::default(),
+            rules: Vec::new(),
+        };
+
+        {
+            let mut iter = StyleSheetParser::new(&mut input, &mut rule_parser);
+            while let Some(result) = iter.next() {
+                match result {
+                    Ok(rule_start) => {
+                        // TODO(emilio, nesting): sanitize nested CSS rules, probably?
+                        if let Some(ref mut data) = sanitization_data {
+                            if let Some(ref rule) = iter.parser.rules.last() {
+                                if !data.kind.allows(rule) {
+                                    iter.parser.rules.pop();
+                                    continue;
+                                }
+                            }
+                            let end = iter.input.position().byte_index();
+                            data.output.push_str(&css[rule_start.byte_index()..end]);
+                        }
+                    },
+                    Err((error, slice)) => {
+                        let location = error.location;
+                        let error = ContextualParseError::InvalidRule(slice, error);
+                        iter.parser.context.log_css_error(location, error);
+                    },
+                }
+            }
+        }
+
+        let source_map_url = input.current_source_map_url().map(String::from);
+        let source_url = input.current_source_url().map(String::from);
+        (
+            rule_parser.context.namespaces.into_owned(),
+            rule_parser.rules,
+            source_map_url,
+            source_url,
+        )
+    }
+
+    /// Creates an empty stylesheet and parses it with a given base url, origin
+    /// and media.
+    ///
+    /// Effectively creates a new stylesheet and forwards the hard work to
+    /// `Stylesheet::update_from_str`.
+    pub fn from_str(
+        css: &str,
+        url_data: UrlExtraData,
+        origin: Origin,
+        media: Arc<Locked<MediaList>>,
+        shared_lock: SharedRwLock,
+        stylesheet_loader: Option<&dyn StylesheetLoader>,
+        error_reporter: Option<&dyn ParseErrorReporter>,
+        quirks_mode: QuirksMode,
+        line_number_offset: u32,
+        allow_import_rules: AllowImportRules,
+    ) -> Self {
+        // FIXME: Consider adding use counters to Servo?
+        let contents = StylesheetContents::from_str(
+            css,
+            url_data,
+            origin,
+            &shared_lock,
+            stylesheet_loader,
+            error_reporter,
+            quirks_mode,
+            line_number_offset,
+            /* use_counters = */ None,
+            allow_import_rules,
+            /* sanitized_output = */ None,
+        );
+
+        Stylesheet {
+            contents,
+            shared_lock,
+            media,
+            disabled: AtomicBool::new(false),
+        }
+    }
+
+    /// Returns whether the stylesheet has been explicitly disabled through the
+    /// CSSOM.
+    pub fn disabled(&self) -> bool {
+        self.disabled.load(Ordering::SeqCst)
+    }
+
+    /// Records that the stylesheet has been explicitly disabled through the
+    /// CSSOM.
+    ///
+    /// Returns whether the the call resulted in a change in disabled state.
+    ///
+    /// Disabled stylesheets remain in the document, but their rules are not
+    /// added to the Stylist.
+    pub fn set_disabled(&self, disabled: bool) -> bool {
+        self.disabled.swap(disabled, Ordering::SeqCst) != disabled
+    }
+}
+
+#[cfg(feature = "servo")]
+impl Clone for Stylesheet {
+    fn clone(&self) -> Self {
+        // Create a new lock for our clone.
+        let lock = self.shared_lock.clone();
+        let guard = self.shared_lock.read();
+
+        // Make a deep clone of the media, using the new lock.
+        let media = self.media.read_with(&guard).clone();
+        let media = Arc::new(lock.wrap(media));
+        let contents = Arc::new(self.contents.deep_clone_with_lock(
+            &lock,
+            &guard,
+            &DeepCloneParams,
+        ));
+
+        Stylesheet {
+            contents,
+            media,
+            shared_lock: lock,
+            disabled: AtomicBool::new(self.disabled.load(Ordering::SeqCst)),
+        }
+    }
+}