style: Remove HasBoxFFI

HasBoxFFI and HasArcFFI aren't great, see bug 1831242 as for examples of
why.

HasArcFFI requires a bit more care, but HasBoxFFI doesn't give us much
benefit. Instead use the same type in the FFI boundary.

Differential Revision: https://phabricator.services.mozilla.com/D177252

components/style/author_styles.rs

@@ -6,8 +6,6 @@
 //! ones used for ShadowRoot.
 
 use crate::dom::TElement;
-#[cfg(feature = "gecko")]
-use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use crate::invalidation::media_queries::ToMediaListKey;
 use crate::shared_lock::SharedRwLockReadGuard;
 use crate::stylesheet_set::AuthorStylesheetSet;
@@ -19,7 +17,7 @@ use servo_arc::Arc;
 /// A set of author stylesheets and their computed representation, such as the
 /// ones used for ShadowRoot.
 #[derive(MallocSizeOf)]
-pub struct AuthorStyles<S>
+pub struct GenericAuthorStyles<S>
 where
     S: StylesheetInDocument + PartialEq + 'static,
 {
@@ -31,11 +29,13 @@ where
     pub data: Arc<CascadeData>,
 }
 
+pub use self::GenericAuthorStyles as AuthorStyles;
+
 lazy_static! {
     static ref EMPTY_CASCADE_DATA: Arc<CascadeData> = Arc::new_leaked(CascadeData::new());
 }
 
-impl<S> AuthorStyles<S>
+impl<S> GenericAuthorStyles<S>
 where
     S: StylesheetInDocument + PartialEq + 'static,
 {
@@ -68,12 +68,3 @@ where
         }
     }
 }
-
-#[cfg(feature = "gecko")]
-unsafe impl HasFFI for AuthorStyles<crate::gecko::data::GeckoStyleSheet> {
-    type FFIType = crate::gecko_bindings::structs::RawServoAuthorStyles;
-}
-#[cfg(feature = "gecko")]
-unsafe impl HasSimpleFFI for AuthorStyles<crate::gecko::data::GeckoStyleSheet> {}
-#[cfg(feature = "gecko")]
-unsafe impl HasBoxFFI for AuthorStyles<crate::gecko::data::GeckoStyleSheet> {}

components/style/gecko/boxed_types.rs

@@ -1,31 +0,0 @@
-/* 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/. */
-
-//! FFI implementations for types listed in ServoBoxedTypeList.h.
-
-use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
-use crate::properties::animated_properties::AnimationValueMap;
-use to_shmem::SharedMemoryBuilder;
-
-// TODO(heycam): The FFI impls for most of the types in ServoBoxedTypeList.h are spread across
-// various files at the moment, but should probably all move here, and use macros to define
-// them more succinctly, like we do in arc_types.rs.
-
-#[cfg(feature = "gecko")]
-unsafe impl HasFFI for AnimationValueMap {
-    type FFIType = crate::gecko_bindings::bindings::RawServoAnimationValueMap;
-}
-#[cfg(feature = "gecko")]
-unsafe impl HasSimpleFFI for AnimationValueMap {}
-#[cfg(feature = "gecko")]
-unsafe impl HasBoxFFI for AnimationValueMap {}
-
-#[cfg(feature = "gecko")]
-unsafe impl HasFFI for SharedMemoryBuilder {
-    type FFIType = crate::gecko_bindings::bindings::RawServoSharedMemoryBuilder;
-}
-#[cfg(feature = "gecko")]
-unsafe impl HasSimpleFFI for SharedMemoryBuilder {}
-#[cfg(feature = "gecko")]
-unsafe impl HasBoxFFI for SharedMemoryBuilder {}

components/style/gecko/data.rs

@@ -6,9 +6,8 @@
 
 use crate::dom::TElement;
 use crate::gecko_bindings::bindings;
-use crate::gecko_bindings::structs::{self, RawServoStyleSet, ServoStyleSetSizes};
-use crate::gecko_bindings::structs::{StyleSheet as DomStyleSheet, StyleSheetInfo};
-use crate::gecko_bindings::sugar::ownership::{HasArcFFI, HasBoxFFI, HasFFI, HasSimpleFFI};
+use crate::gecko_bindings::structs::{self, ServoStyleSetSizes, StyleSheet as DomStyleSheet, StyleSheetInfo};
+use crate::gecko_bindings::sugar::ownership::HasArcFFI;
 use crate::invalidation::media_queries::{MediaListKey, ToMediaListKey};
 use crate::media_queries::{Device, MediaList};
 use crate::properties::ComputedValues;
@@ -201,8 +200,5 @@ impl PerDocumentStyleDataImpl {
     }
 }
 
-unsafe impl HasFFI for PerDocumentStyleData {
-    type FFIType = RawServoStyleSet;
-}
-unsafe impl HasSimpleFFI for PerDocumentStyleData {}
-unsafe impl HasBoxFFI for PerDocumentStyleData {}
+/// The gecko-specific AuthorStyles instantiation.
+pub type AuthorStyles = crate::author_styles::AuthorStyles<GeckoStyleSheet>;

components/style/gecko/mod.rs

@@ -8,7 +8,6 @@
 mod non_ts_pseudo_class_list;
 
 pub mod arc_types;
-pub mod boxed_types;
 pub mod conversions;
 pub mod data;
 pub mod media_features;

components/style/gecko/selector_parser.rs

@@ -5,8 +5,6 @@
 //! Gecko-specific bits for selector-parsing.
 
 use crate::computed_value_flags::ComputedValueFlags;
-use crate::gecko_bindings::structs::RawServoSelectorList;
-use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use crate::invalidation::element::document_state::InvalidationMatchingData;
 use crate::properties::ComputedValues;
 use crate::selector_parser::{Direction, HorizontalDirection, SelectorParser};
@@ -17,7 +15,6 @@ use cssparser::{BasicParseError, BasicParseErrorKind, Parser};
 use cssparser::{CowRcStr, SourceLocation, ToCss, Token};
 use dom::{DocumentState, ElementState};
 use selectors::parser::SelectorParseErrorKind;
-use selectors::SelectorList;
 use std::fmt;
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss as ToCss_};
 use thin_vec::ThinVec;
@@ -489,12 +486,6 @@ impl SelectorImpl {
     }
 }
 
-unsafe impl HasFFI for SelectorList<SelectorImpl> {
-    type FFIType = RawServoSelectorList;
-}
-unsafe impl HasSimpleFFI for SelectorList<SelectorImpl> {}
-unsafe impl HasBoxFFI for SelectorList<SelectorImpl> {}
-
 // Selector and component sizes are important for matching performance.
 size_of_test!(selectors::parser::Selector<SelectorImpl>, 8);
 size_of_test!(selectors::parser::Component<SelectorImpl>, 24);

components/style/gecko/wrapper.rs

@@ -15,11 +15,9 @@
 //! the separation between the style system implementation and everything else.
 
 use crate::applicable_declarations::ApplicableDeclarationBlock;
-use crate::author_styles::AuthorStyles;
 use crate::context::{PostAnimationTasks, QuirksMode, SharedStyleContext, UpdateAnimationsTasks};
 use crate::data::ElementData;
 use crate::dom::{LayoutIterator, NodeInfo, OpaqueNode, TDocument, TElement, TNode, TShadowRoot};
-use crate::gecko::data::GeckoStyleSheet;
 use crate::gecko::selector_parser::{NonTSPseudoClass, PseudoElement, SelectorImpl};
 use crate::gecko::snapshot_helpers;
 use crate::gecko_bindings::bindings;
@@ -50,7 +48,7 @@ use crate::gecko_bindings::structs::NODE_DESCENDANTS_NEED_FRAMES;
 use crate::gecko_bindings::structs::NODE_NEEDS_FRAME;
 use crate::gecko_bindings::structs::{nsAtom, nsIContent, nsINode_BooleanFlag};
 use crate::gecko_bindings::structs::{nsINode as RawGeckoNode, Element as RawGeckoElement};
-use crate::gecko_bindings::sugar::ownership::{HasArcFFI, HasSimpleFFI};
+use crate::gecko_bindings::sugar::ownership::HasArcFFI;
 use crate::global_style_data::GLOBAL_STYLE_DATA;
 use crate::invalidation::element::restyle_hints::RestyleHint;
 use crate::media_queries::Device;
@@ -180,7 +178,6 @@ impl<'lr> TShadowRoot for GeckoShadowRoot<'lr> {
         Self: 'a,
     {
         let author_styles = unsafe { self.0.mServoStyles.mPtr.as_ref()? };
-        let author_styles = AuthorStyles::<GeckoStyleSheet>::from_ffi(author_styles);
         Some(&author_styles.data)
     }
 
@@ -925,7 +922,7 @@ fn get_animation_rule(
         Gecko_GetAnimationRule(
             element.0,
             cascade_level,
-            AnimationValueMap::as_ffi_mut(&mut animation_values),
+            &mut animation_values,
         )
     } {
         let shared_lock = &GLOBAL_STYLE_DATA.shared_lock;

components/style/gecko_bindings/sugar/ownership.rs

@@ -56,26 +56,6 @@ pub unsafe trait HasSimpleFFI: HasFFI {
     }
 }
 
-/// Indicates that the given Servo type is passed over FFI
-/// as a Box
-pub unsafe trait HasBoxFFI: HasSimpleFFI {
-    #[inline]
-    /// Converts a borrowed Arc to a borrowed FFI reference.
-    ///
-    /// &Arc<ServoType> -> &GeckoType
-    fn into_ffi(self: Box<Self>) -> Owned<Self::FFIType> {
-        unsafe { transmute(self) }
-    }
-
-    /// Drops an owned FFI pointer. This conceptually takes the
-    /// Owned<Self::FFIType>, except it's a bit of a paint to do that without
-    /// much benefit.
-    #[inline]
-    unsafe fn drop_ffi(ptr: *mut Self::FFIType) {
-        let _ = Box::from_raw(ptr as *mut Self);
-    }
-}
-
 /// Helper trait for conversions between FFI Strong/Borrowed types and Arcs
 ///
 /// Should be implemented by types which are passed over FFI as Arcs via Strong
@@ -265,75 +245,6 @@ unsafe impl<T: HasArcFFI> FFIArcHelpers for Arc<T> {
     }
 }
 
-#[repr(C)]
-#[derive(Debug)]
-/// Gecko-FFI-safe owned pointer.
-///
-/// Cannot be null, and leaks on drop, so needs to be converted into a rust-side
-/// `Box` before.
-pub struct Owned<GeckoType> {
-    ptr: *mut GeckoType,
-    _marker: PhantomData<GeckoType>,
-}
-
-impl<GeckoType> Owned<GeckoType> {
-    /// Converts this instance to a (non-null) instance of `OwnedOrNull`.
-    pub fn maybe(self) -> OwnedOrNull<GeckoType> {
-        unsafe { transmute(self) }
-    }
-}
-
-impl<GeckoType> Deref for Owned<GeckoType> {
-    type Target = GeckoType;
-    fn deref(&self) -> &GeckoType {
-        unsafe { &*self.ptr }
-    }
-}
-
-impl<GeckoType> DerefMut for Owned<GeckoType> {
-    fn deref_mut(&mut self) -> &mut GeckoType {
-        unsafe { &mut *self.ptr }
-    }
-}
-
-#[repr(C)]
-/// Gecko-FFI-safe owned pointer.
-///
-/// Can be null, and just as `Owned` leaks on `Drop`.
-pub struct OwnedOrNull<GeckoType> {
-    ptr: *mut GeckoType,
-    _marker: PhantomData<GeckoType>,
-}
-
-impl<GeckoType> OwnedOrNull<GeckoType> {
-    /// Returns a null pointer.
-    #[inline]
-    pub fn null() -> Self {
-        Self {
-            ptr: ptr::null_mut(),
-            _marker: PhantomData,
-        }
-    }
-
-    /// Returns whether this pointer is null.
-    #[inline]
-    pub fn is_null(&self) -> bool {
-        self.ptr.is_null()
-    }
-
-    /// Gets a immutable reference to the underlying Gecko type, or `None` if
-    /// null.
-    pub fn borrow(&self) -> Option<&GeckoType> {
-        unsafe { transmute(self) }
-    }
-
-    /// Gets a mutable reference to the underlying Gecko type, or `None` if
-    /// null.
-    pub fn borrow_mut(&self) -> Option<&mut GeckoType> {
-        unsafe { transmute(self) }
-    }
-}
-
 impl<T> Deref for CopyablePtr<T> {
     type Target = T;
     fn deref(&self) -> &Self::Target {

components/style/use_counters/mod.rs

@@ -4,8 +4,6 @@
 
 //! Various stuff for CSS property use counters.
 
-#[cfg(feature = "gecko")]
-use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use crate::properties::{CountedUnknownProperty, COUNTED_UNKNOWN_PROPERTY_COUNT};
 use crate::properties::{NonCustomPropertyId, NON_CUSTOM_PROPERTY_ID_COUNT};
 use std::cell::Cell;
@@ -96,14 +94,3 @@ impl UseCounters {
             .merge(&other.counted_unknown_properties);
     }
 }
-
-#[cfg(feature = "gecko")]
-unsafe impl HasFFI for UseCounters {
-    type FFIType = crate::gecko_bindings::structs::StyleUseCounters;
-}
-
-#[cfg(feature = "gecko")]
-unsafe impl HasSimpleFFI for UseCounters {}
-
-#[cfg(feature = "gecko")]
-unsafe impl HasBoxFFI for UseCounters {}

components/style/values/specified/source_size_list.rs

@@ -4,8 +4,6 @@
 
 //! https://html.spec.whatwg.org/multipage/#source-size-list
 
-#[cfg(feature = "gecko")]
-use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use crate::media_queries::Device;
 use crate::parser::{Parse, ParserContext};
 use crate::queries::{FeatureType, QueryCondition};
@@ -134,12 +132,3 @@ impl SourceSizeList {
         }
     }
 }
-
-#[cfg(feature = "gecko")]
-unsafe impl HasFFI for SourceSizeList {
-    type FFIType = crate::gecko_bindings::structs::RawServoSourceSizeList;
-}
-#[cfg(feature = "gecko")]
-unsafe impl HasSimpleFFI for SourceSizeList {}
-#[cfg(feature = "gecko")]
-unsafe impl HasBoxFFI for SourceSizeList {}