Adding upstream version 124.0.1.upstream/124.0.1

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

1 files changed, 909 insertions, 0 deletions

diff --git a/servo/components/style/properties/helpers.mako.rs b/servo/components/style/properties/helpers.mako.rs
new file mode 100644
index 0000000000..968a97aa00
--- /dev/null
+++ b/servo/components/style/properties/helpers.mako.rs
@@ -0,0 +1,909 @@
+/* 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/. */
+
+<%!
+    from data import Keyword, to_rust_ident, to_phys, to_camel_case, SYSTEM_FONT_LONGHANDS
+    from data import (LOGICAL_CORNERS, PHYSICAL_CORNERS, LOGICAL_SIDES,
+                      PHYSICAL_SIDES, LOGICAL_SIZES, LOGICAL_AXES)
+%>
+
+<%def name="predefined_type(name, type, initial_value, parse_method='parse',
+            vector=False, none_value=None, initial_specified_value=None,
+            allow_quirks='No', **kwargs)">
+    <%def name="predefined_type_inner(name, type, initial_value, parse_method)">
+        #[allow(unused_imports)]
+        use app_units::Au;
+        #[allow(unused_imports)]
+        use crate::values::specified::AllowQuirks;
+        #[allow(unused_imports)]
+        use crate::Zero;
+        #[allow(unused_imports)]
+        use smallvec::SmallVec;
+        pub use crate::values::specified::${type} as SpecifiedValue;
+        pub mod computed_value {
+            pub use crate::values::computed::${type} as T;
+        }
+        % if initial_value:
+        #[inline] pub fn get_initial_value() -> computed_value::T { ${initial_value} }
+        % endif
+        % if initial_specified_value:
+        #[inline] pub fn get_initial_specified_value() -> SpecifiedValue { ${initial_specified_value} }
+        % endif
+        #[allow(unused_variables)]
+        #[inline]
+        pub fn parse<'i, 't>(
+            context: &ParserContext,
+            input: &mut Parser<'i, 't>,
+        ) -> Result<SpecifiedValue, ParseError<'i>> {
+            % if allow_quirks != "No":
+            specified::${type}::${parse_method}_quirky(context, input, AllowQuirks::${allow_quirks})
+            % elif parse_method != "parse":
+            specified::${type}::${parse_method}(context, input)
+            % else:
+            <specified::${type} as crate::parser::Parse>::parse(context, input)
+            % endif
+        }
+    </%def>
+    % if vector:
+        <%call
+            expr="vector_longhand(name, predefined_type=type, allow_empty=not initial_value, none_value=none_value, **kwargs)"
+        >
+            ${predefined_type_inner(name, type, initial_value, parse_method)}
+            % if caller:
+            ${caller.body()}
+            % endif
+        </%call>
+    % else:
+        <%call expr="longhand(name, predefined_type=type, **kwargs)">
+            ${predefined_type_inner(name, type, initial_value, parse_method)}
+            % if caller:
+            ${caller.body()}
+            % endif
+        </%call>
+    % endif
+</%def>
+
+// The setup here is roughly:
+//
+//  * UnderlyingList is the list that is stored in the computed value. This may
+//    be a shared ArcSlice if the property is inherited.
+//  * UnderlyingOwnedList is the list that is used for animation.
+//  * Specified values always use OwnedSlice, since it's more compact.
+//  * computed_value::List is just a convenient alias that you can use for the
+//    computed value list, since this is in the computed_value module.
+//
+// If simple_vector_bindings is true, then we don't use the complex iterator
+// machinery and set_foo_from, and just compute the value like any other
+// longhand.
+<%def name="vector_longhand(name, animation_value_type=None,
+                            vector_animation_type=None, allow_empty=False,
+                            none_value=None,
+                            simple_vector_bindings=False,
+                            separator='Comma',
+                            **kwargs)">
+    <%call expr="longhand(name, animation_value_type=animation_value_type, vector=True,
+                          simple_vector_bindings=simple_vector_bindings, **kwargs)">
+        #[allow(unused_imports)]
+        use smallvec::SmallVec;
+
+        pub mod single_value {
+            #[allow(unused_imports)]
+            use cssparser::{Parser, BasicParseError};
+            #[allow(unused_imports)]
+            use crate::parser::{Parse, ParserContext};
+            #[allow(unused_imports)]
+            use crate::properties::ShorthandId;
+            #[allow(unused_imports)]
+            use selectors::parser::SelectorParseErrorKind;
+            #[allow(unused_imports)]
+            use style_traits::{ParseError, StyleParseErrorKind};
+            #[allow(unused_imports)]
+            use crate::values::computed::{Context, ToComputedValue};
+            #[allow(unused_imports)]
+            use crate::values::{computed, specified};
+            ${caller.body()}
+        }
+
+        /// The definition of the computed value for ${name}.
+        pub mod computed_value {
+            #[allow(unused_imports)]
+            use crate::values::animated::ToAnimatedValue;
+            #[allow(unused_imports)]
+            use crate::values::resolved::ToResolvedValue;
+            pub use super::single_value::computed_value as single_value;
+            pub use self::single_value::T as SingleComputedValue;
+            % if not allow_empty:
+            use smallvec::SmallVec;
+            % endif
+            use crate::values::computed::ComputedVecIter;
+
+            <%
+                is_shared_list = allow_empty and \
+                    data.longhands_by_name[name].style_struct.inherited
+            %>
+
+            // FIXME(emilio): Add an OwnedNonEmptySlice type, and figure out
+            // something for transition-name, which is the only remaining user
+            // of NotInitial.
+            pub type UnderlyingList<T> =
+                % if allow_empty:
+                % if data.longhands_by_name[name].style_struct.inherited:
+                    crate::ArcSlice<T>;
+                % else:
+                    crate::OwnedSlice<T>;
+                % endif
+                % else:
+                    SmallVec<[T; 1]>;
+                % endif
+
+            pub type UnderlyingOwnedList<T> =
+                % if allow_empty:
+                    crate::OwnedSlice<T>;
+                % else:
+                    SmallVec<[T; 1]>;
+                % endif
+
+
+            /// The generic type defining the animated and resolved values for
+            /// this property.
+            ///
+            /// Making this type generic allows the compiler to figure out the
+            /// animated value for us, instead of having to implement it
+            /// manually for every type we care about.
+            #[derive(Clone, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToResolvedValue, ToCss)]
+            % if separator == "Comma":
+            #[css(comma)]
+            % endif
+            pub struct OwnedList<T>(
+                % if not allow_empty:
+                #[css(iterable)]
+                % else:
+                #[css(if_empty = "none", iterable)]
+                % endif
+                pub UnderlyingOwnedList<T>,
+            );
+
+            /// The computed value for this property.
+            % if not is_shared_list:
+            pub type ComputedList = OwnedList<single_value::T>;
+            pub use self::OwnedList as List;
+            % else:
+            pub use self::ComputedList as List;
+
+            #[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+            % if separator == "Comma":
+            #[css(comma)]
+            % endif
+            pub struct ComputedList(
+                % if not allow_empty:
+                #[css(iterable)]
+                % else:
+                #[css(if_empty = "none", iterable)]
+                % endif
+                % if is_shared_list:
+                #[ignore_malloc_size_of = "Arc"]
+                % endif
+                pub UnderlyingList<single_value::T>,
+            );
+
+            type ResolvedList = OwnedList<<single_value::T as ToResolvedValue>::ResolvedValue>;
+            impl ToResolvedValue for ComputedList {
+                type ResolvedValue = ResolvedList;
+
+                fn to_resolved_value(self, context: &crate::values::resolved::Context) -> Self::ResolvedValue {
+                    OwnedList(
+                        self.0
+                            .iter()
+                            .cloned()
+                            .map(|v| v.to_resolved_value(context))
+                            .collect()
+                    )
+                }
+
+                fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+                    % if not is_shared_list:
+                    use std::iter::FromIterator;
+                    % endif
+                    let iter =
+                        resolved.0.into_iter().map(ToResolvedValue::from_resolved_value);
+                    ComputedList(UnderlyingList::from_iter(iter))
+                }
+            }
+            % endif
+
+            % if simple_vector_bindings:
+            impl From<ComputedList> for UnderlyingList<single_value::T> {
+                #[inline]
+                fn from(l: ComputedList) -> Self {
+                    l.0
+                }
+            }
+            impl From<UnderlyingList<single_value::T>> for ComputedList {
+                #[inline]
+                fn from(l: UnderlyingList<single_value::T>) -> Self {
+                    List(l)
+                }
+            }
+            % endif
+
+            % if vector_animation_type:
+            % if not animation_value_type:
+                Sorry, this is stupid but needed for now.
+            % endif
+
+            use crate::values::animated::{Animate, ToAnimatedZero, Procedure, lists};
+            use crate::values::distance::{SquaredDistance, ComputeSquaredDistance};
+
+            // FIXME(emilio): For some reason rust thinks that this alias is
+            // unused, even though it's clearly used below?
+            #[allow(unused)]
+            type AnimatedList = OwnedList<<single_value::T as ToAnimatedValue>::AnimatedValue>;
+
+            % if is_shared_list:
+            impl ToAnimatedValue for ComputedList {
+                type AnimatedValue = AnimatedList;
+
+                fn to_animated_value(self) -> Self::AnimatedValue {
+                    OwnedList(
+                        self.0.iter().map(|v| v.clone().to_animated_value()).collect()
+                    )
+                }
+
+                fn from_animated_value(animated: Self::AnimatedValue) -> Self {
+                    let iter =
+                        animated.0.into_iter().map(ToAnimatedValue::from_animated_value);
+                    ComputedList(UnderlyingList::from_iter(iter))
+                }
+            }
+            % endif
+
+            impl ToAnimatedZero for AnimatedList {
+                fn to_animated_zero(&self) -> Result<Self, ()> { Err(()) }
+            }
+
+            impl Animate for AnimatedList {
+                fn animate(
+                    &self,
+                    other: &Self,
+                    procedure: Procedure,
+                ) -> Result<Self, ()> {
+                    Ok(OwnedList(
+                        lists::${vector_animation_type}::animate(&self.0, &other.0, procedure)?
+                    ))
+                }
+            }
+            impl ComputeSquaredDistance for AnimatedList {
+                fn compute_squared_distance(
+                    &self,
+                    other: &Self,
+                ) -> Result<SquaredDistance, ()> {
+                    lists::${vector_animation_type}::squared_distance(&self.0, &other.0)
+                }
+            }
+            % endif
+
+            /// The computed value, effectively a list of single values.
+            pub use self::ComputedList as T;
+
+            pub type Iter<'a, 'cx, 'cx_a> = ComputedVecIter<'a, 'cx, 'cx_a, super::single_value::SpecifiedValue>;
+        }
+
+        /// The specified value of ${name}.
+        #[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
+        % if none_value:
+        #[value_info(other_values = "none")]
+        % endif
+        % if separator == "Comma":
+        #[css(comma)]
+        % endif
+        pub struct SpecifiedValue(
+            % if not allow_empty:
+            #[css(iterable)]
+            % else:
+            #[css(if_empty = "none", iterable)]
+            % endif
+            pub crate::OwnedSlice<single_value::SpecifiedValue>,
+        );
+
+        pub fn get_initial_value() -> computed_value::T {
+            % if allow_empty:
+                computed_value::List(Default::default())
+            % else:
+                let mut v = SmallVec::new();
+                v.push(single_value::get_initial_value());
+                computed_value::List(v)
+            % endif
+        }
+
+        pub fn parse<'i, 't>(
+            context: &ParserContext,
+            input: &mut Parser<'i, 't>,
+        ) -> Result<SpecifiedValue, ParseError<'i>> {
+            use style_traits::Separator;
+
+            % if allow_empty or none_value:
+            if input.try_parse(|input| input.expect_ident_matching("none")).is_ok() {
+                % if allow_empty:
+                return Ok(SpecifiedValue(Default::default()))
+                % else:
+                return Ok(SpecifiedValue(crate::OwnedSlice::from(vec![${none_value}])))
+                % endif
+            }
+            % endif
+
+            let v = style_traits::${separator}::parse(input, |parser| {
+                single_value::parse(context, parser)
+            })?;
+            Ok(SpecifiedValue(v.into()))
+        }
+
+        pub use self::single_value::SpecifiedValue as SingleSpecifiedValue;
+
+        % if not simple_vector_bindings and engine == "gecko":
+        impl SpecifiedValue {
+            fn compute_iter<'a, 'cx, 'cx_a>(
+                &'a self,
+                context: &'cx Context<'cx_a>,
+            ) -> computed_value::Iter<'a, 'cx, 'cx_a> {
+                computed_value::Iter::new(context, &self.0)
+            }
+        }
+        % endif
+
+        impl ToComputedValue for SpecifiedValue {
+            type ComputedValue = computed_value::T;
+
+            #[inline]
+            fn to_computed_value(&self, context: &Context) -> computed_value::T {
+                % if not is_shared_list:
+                use std::iter::FromIterator;
+                % endif
+                computed_value::List(computed_value::UnderlyingList::from_iter(
+                    self.0.iter().map(|i| i.to_computed_value(context))
+                ))
+            }
+
+            #[inline]
+            fn from_computed_value(computed: &computed_value::T) -> Self {
+                let iter = computed.0.iter().map(ToComputedValue::from_computed_value);
+                SpecifiedValue(iter.collect())
+            }
+        }
+    </%call>
+</%def>
+<%def name="longhand(*args, **kwargs)">
+    <%
+        property = data.declare_longhand(*args, **kwargs)
+        if property is None:
+            return ""
+    %>
+    /// ${property.spec}
+    pub mod ${property.ident} {
+        #[allow(unused_imports)]
+        use cssparser::{Parser, BasicParseError, Token};
+        #[allow(unused_imports)]
+        use crate::parser::{Parse, ParserContext};
+        #[allow(unused_imports)]
+        use crate::properties::{UnparsedValue, ShorthandId};
+        #[allow(unused_imports)]
+        use crate::error_reporting::ParseErrorReporter;
+        #[allow(unused_imports)]
+        use crate::properties::longhands;
+        #[allow(unused_imports)]
+        use crate::properties::{LonghandId, LonghandIdSet};
+        #[allow(unused_imports)]
+        use crate::properties::{CSSWideKeyword, ComputedValues, PropertyDeclaration};
+        #[allow(unused_imports)]
+        use crate::properties::style_structs;
+        #[allow(unused_imports)]
+        use selectors::parser::SelectorParseErrorKind;
+        #[allow(unused_imports)]
+        use servo_arc::Arc;
+        #[allow(unused_imports)]
+        use style_traits::{ParseError, StyleParseErrorKind};
+        #[allow(unused_imports)]
+        use crate::values::computed::{Context, ToComputedValue};
+        #[allow(unused_imports)]
+        use crate::values::{computed, generics, specified};
+        #[allow(unused_imports)]
+        use crate::Atom;
+        ${caller.body()}
+        #[allow(unused_variables)]
+        pub unsafe fn cascade_property(
+            declaration: &PropertyDeclaration,
+            context: &mut computed::Context,
+        ) {
+            % if property.logical:
+            declaration.debug_crash("Should physicalize before entering here");
+            % else:
+            context.for_non_inherited_property = ${"false" if property.style_struct.inherited else "true"};
+            % if property.logical_group:
+            debug_assert_eq!(
+                declaration.id().as_longhand().unwrap().logical_group(),
+                LonghandId::${property.camel_case}.logical_group(),
+            );
+            % else:
+            debug_assert_eq!(
+                declaration.id().as_longhand().unwrap(),
+                LonghandId::${property.camel_case},
+            );
+            % endif
+            let specified_value = match *declaration {
+                PropertyDeclaration::CSSWideKeyword(ref wk) => {
+                    match wk.keyword {
+                        % if not property.style_struct.inherited:
+                        CSSWideKeyword::Unset |
+                        % endif
+                        CSSWideKeyword::Initial => {
+                            % if not property.style_struct.inherited:
+                                declaration.debug_crash("Unexpected initial or unset for non-inherited property");
+                            % else:
+                                context.builder.reset_${property.ident}();
+                            % endif
+                        },
+                        % if property.style_struct.inherited:
+                        CSSWideKeyword::Unset |
+                        % endif
+                        CSSWideKeyword::Inherit => {
+                            % if property.style_struct.inherited:
+                                declaration.debug_crash("Unexpected inherit or unset for inherited property");
+                            % else:
+                                context.rule_cache_conditions.borrow_mut().set_uncacheable();
+                                context.builder.inherit_${property.ident}();
+                            % endif
+                        }
+                        CSSWideKeyword::RevertLayer |
+                        CSSWideKeyword::Revert => {
+                            declaration.debug_crash("Found revert/revert-layer not deal with");
+                        },
+                    }
+                    return;
+                },
+                #[cfg(debug_assertions)]
+                PropertyDeclaration::WithVariables(..) => {
+                    declaration.debug_crash("Found variables not substituted");
+                    return;
+                },
+                _ => unsafe {
+                    declaration.unchecked_value_as::<${property.specified_type()}>()
+                },
+            };
+
+            % if property.ident in SYSTEM_FONT_LONGHANDS and engine == "gecko":
+            if let Some(sf) = specified_value.get_system() {
+                longhands::system_font::resolve_system_font(sf, context);
+            }
+            % endif
+
+            % if property.is_vector and not property.simple_vector_bindings and engine == "gecko":
+                // In the case of a vector property we want to pass down an
+                // iterator so that this can be computed without allocation.
+                //
+                // However, computing requires a context, but the style struct
+                // being mutated is on the context. We temporarily remove it,
+                // mutate it, and then put it back. Vector longhands cannot
+                // touch their own style struct whilst computing, else this will
+                // panic.
+                let mut s =
+                    context.builder.take_${data.current_style_struct.name_lower}();
+                {
+                    let iter = specified_value.compute_iter(context);
+                    s.set_${property.ident}(iter);
+                }
+                context.builder.put_${data.current_style_struct.name_lower}(s);
+            % else:
+                % if property.boxed:
+                let computed = (**specified_value).to_computed_value(context);
+                % else:
+                let computed = specified_value.to_computed_value(context);
+                % endif
+                context.builder.set_${property.ident}(computed)
+            % endif
+            % endif
+        }
+
+        pub fn parse_declared<'i, 't>(
+            context: &ParserContext,
+            input: &mut Parser<'i, 't>,
+        ) -> Result<PropertyDeclaration, ParseError<'i>> {
+            % if property.allow_quirks != "No":
+                parse_quirky(context, input, specified::AllowQuirks::${property.allow_quirks})
+            % else:
+                parse(context, input)
+            % endif
+            % if property.boxed:
+                .map(Box::new)
+            % endif
+                .map(PropertyDeclaration::${property.camel_case})
+        }
+    }
+</%def>
+
+<%def name="gecko_keyword_conversion(keyword, values=None, type='SpecifiedValue', cast_to=None)">
+    <%
+        if not values:
+            values = keyword.values_for(engine)
+        maybe_cast = "as %s" % cast_to if cast_to else ""
+        const_type = cast_to if cast_to else "u32"
+    %>
+    #[cfg(feature = "gecko")]
+    impl ${type} {
+        /// Obtain a specified value from a Gecko keyword value
+        ///
+        /// Intended for use with presentation attributes, not style structs
+        pub fn from_gecko_keyword(kw: u32) -> Self {
+            use crate::gecko_bindings::structs;
+            % for value in values:
+                // We can't match on enum values if we're matching on a u32
+                const ${to_rust_ident(value).upper()}: ${const_type}
+                    = structs::${keyword.gecko_constant(value)} as ${const_type};
+            % endfor
+            match kw ${maybe_cast} {
+                % for value in values:
+                    ${to_rust_ident(value).upper()} => ${type}::${to_camel_case(value)},
+                % endfor
+                _ => panic!("Found unexpected value in style struct for ${keyword.name} property"),
+            }
+        }
+    }
+</%def>
+
+<%def name="gecko_bitflags_conversion(bit_map, gecko_bit_prefix, type, kw_type='u8')">
+    #[cfg(feature = "gecko")]
+    impl ${type} {
+        /// Obtain a specified value from a Gecko keyword value
+        ///
+        /// Intended for use with presentation attributes, not style structs
+        pub fn from_gecko_keyword(kw: ${kw_type}) -> Self {
+            % for gecko_bit in bit_map.values():
+            use crate::gecko_bindings::structs::${gecko_bit_prefix}${gecko_bit};
+            % endfor
+
+            let mut bits = ${type}::empty();
+            % for servo_bit, gecko_bit in bit_map.items():
+                if kw & (${gecko_bit_prefix}${gecko_bit} as ${kw_type}) != 0 {
+                    bits |= ${servo_bit};
+                }
+            % endfor
+            bits
+        }
+
+        pub fn to_gecko_keyword(self) -> ${kw_type} {
+            % for gecko_bit in bit_map.values():
+            use crate::gecko_bindings::structs::${gecko_bit_prefix}${gecko_bit};
+            % endfor
+
+            let mut bits: ${kw_type} = 0;
+            // FIXME: if we ensure that the Servo bitflags storage is the same
+            // as Gecko's one, we can just copy it.
+            % for servo_bit, gecko_bit in bit_map.items():
+                if self.contains(${servo_bit}) {
+                    bits |= ${gecko_bit_prefix}${gecko_bit} as ${kw_type};
+                }
+            % endfor
+            bits
+        }
+    }
+</%def>
+
+<%def name="single_keyword(name, values, vector=False,
+            needs_conversion=False, **kwargs)">
+    <%
+        keyword_kwargs = {a: kwargs.pop(a, None) for a in [
+            'gecko_constant_prefix',
+            'gecko_enum_prefix',
+            'extra_gecko_values',
+            'extra_servo_2013_values',
+            'extra_servo_2020_values',
+            'gecko_aliases',
+            'servo_2013_aliases',
+            'servo_2020_aliases',
+            'custom_consts',
+            'gecko_inexhaustive',
+            'gecko_strip_moz_prefix',
+        ]}
+    %>
+
+    <%def name="inner_body(keyword, needs_conversion=False)">
+        pub use self::computed_value::T as SpecifiedValue;
+        pub mod computed_value {
+            #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+            #[derive(Clone, Copy, Debug, Eq, FromPrimitive, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+            pub enum T {
+            % for variant in keyword.values_for(engine):
+            <%
+                aliases = []
+                for alias, v in keyword.aliases_for(engine).items():
+                    if variant == v:
+                        aliases.append(alias)
+            %>
+            % if aliases:
+            #[parse(aliases = "${','.join(sorted(aliases))}")]
+            % endif
+            ${to_camel_case(variant)},
+            % endfor
+            }
+        }
+        #[inline]
+        pub fn get_initial_value() -> computed_value::T {
+            computed_value::T::${to_camel_case(values.split()[0])}
+        }
+        #[inline]
+        pub fn get_initial_specified_value() -> SpecifiedValue {
+            SpecifiedValue::${to_camel_case(values.split()[0])}
+        }
+        #[inline]
+        pub fn parse<'i, 't>(_context: &ParserContext, input: &mut Parser<'i, 't>)
+                             -> Result<SpecifiedValue, ParseError<'i>> {
+            SpecifiedValue::parse(input)
+        }
+
+        % if needs_conversion:
+            <%
+                conversion_values = keyword.values_for(engine) + list(keyword.aliases_for(engine).keys())
+            %>
+            ${gecko_keyword_conversion(keyword, values=conversion_values)}
+        % endif
+    </%def>
+    % if vector:
+        <%call expr="vector_longhand(name, keyword=Keyword(name, values, **keyword_kwargs), **kwargs)">
+            ${inner_body(Keyword(name, values, **keyword_kwargs))}
+            % if caller:
+            ${caller.body()}
+            % endif
+        </%call>
+    % else:
+        <%call expr="longhand(name, keyword=Keyword(name, values, **keyword_kwargs), **kwargs)">
+            ${inner_body(Keyword(name, values, **keyword_kwargs),
+                         needs_conversion=needs_conversion)}
+            % if caller:
+            ${caller.body()}
+            % endif
+        </%call>
+    % endif
+</%def>
+
+<%def name="shorthand(name, sub_properties, derive_serialize=False,
+                      derive_value_info=True, **kwargs)">
+<%
+    shorthand = data.declare_shorthand(name, sub_properties.split(), **kwargs)
+    # mako doesn't accept non-string value in parameters with <% %> form, so
+    # we have to workaround it this way.
+    if not isinstance(derive_value_info, bool):
+        derive_value_info = eval(derive_value_info)
+%>
+    % if shorthand:
+    /// ${shorthand.spec}
+    pub mod ${shorthand.ident} {
+        use cssparser::Parser;
+        use crate::parser::ParserContext;
+        use crate::properties::{PropertyDeclaration, SourcePropertyDeclaration, MaybeBoxed, longhands};
+        #[allow(unused_imports)]
+        use selectors::parser::SelectorParseErrorKind;
+        #[allow(unused_imports)]
+        use std::fmt::{self, Write};
+        #[allow(unused_imports)]
+        use style_traits::{ParseError, StyleParseErrorKind};
+        #[allow(unused_imports)]
+        use style_traits::{CssWriter, KeywordsCollectFn, SpecifiedValueInfo, ToCss};
+
+        % if derive_value_info:
+        #[derive(SpecifiedValueInfo)]
+        % endif
+        pub struct Longhands {
+            % for sub_property in shorthand.sub_properties:
+                pub ${sub_property.ident}:
+                    % if sub_property.boxed:
+                        Box<
+                    % endif
+                    longhands::${sub_property.ident}::SpecifiedValue
+                    % if sub_property.boxed:
+                        >
+                    % endif
+                    ,
+            % endfor
+        }
+
+        /// Represents a serializable set of all of the longhand properties that
+        /// correspond to a shorthand.
+        % if derive_serialize:
+        #[derive(ToCss)]
+        % endif
+        pub struct LonghandsToSerialize<'a> {
+            % for sub_property in shorthand.sub_properties:
+                pub ${sub_property.ident}:
+                % if sub_property.may_be_disabled_in(shorthand, engine):
+                    Option<
+                % endif
+                    &'a longhands::${sub_property.ident}::SpecifiedValue,
+                % if sub_property.may_be_disabled_in(shorthand, engine):
+                    >,
+                % endif
+            % endfor
+        }
+
+        impl<'a> LonghandsToSerialize<'a> {
+            /// Tries to get a serializable set of longhands given a set of
+            /// property declarations.
+            pub fn from_iter(iter: impl Iterator<Item = &'a PropertyDeclaration>) -> Result<Self, ()> {
+                // Define all of the expected variables that correspond to the shorthand
+                % for sub_property in shorthand.sub_properties:
+                    let mut ${sub_property.ident} =
+                        None::< &'a longhands::${sub_property.ident}::SpecifiedValue>;
+                % endfor
+
+                // Attempt to assign the incoming declarations to the expected variables
+                for declaration in iter {
+                    match *declaration {
+                        % for sub_property in shorthand.sub_properties:
+                            PropertyDeclaration::${sub_property.camel_case}(ref value) => {
+                                ${sub_property.ident} = Some(value)
+                            },
+                        % endfor
+                        _ => {}
+                    };
+                }
+
+                // If any of the expected variables are missing, return an error
+                match (
+                    % for sub_property in shorthand.sub_properties:
+                        ${sub_property.ident},
+                    % endfor
+                ) {
+
+                    (
+                    % for sub_property in shorthand.sub_properties:
+                        % if sub_property.may_be_disabled_in(shorthand, engine):
+                        ${sub_property.ident},
+                        % else:
+                        Some(${sub_property.ident}),
+                        % endif
+                    % endfor
+                    ) =>
+                    Ok(LonghandsToSerialize {
+                        % for sub_property in shorthand.sub_properties:
+                            ${sub_property.ident},
+                        % endfor
+                    }),
+                    _ => Err(())
+                }
+            }
+        }
+
+        /// Parse the given shorthand and fill the result into the
+        /// `declarations` vector.
+        pub fn parse_into<'i, 't>(
+            declarations: &mut SourcePropertyDeclaration,
+            context: &ParserContext,
+            input: &mut Parser<'i, 't>,
+        ) -> Result<(), ParseError<'i>> {
+            #[allow(unused_imports)]
+            use crate::properties::{NonCustomPropertyId, LonghandId};
+            input.parse_entirely(|input| parse_value(context, input)).map(|longhands| {
+                % for sub_property in shorthand.sub_properties:
+                % if sub_property.may_be_disabled_in(shorthand, engine):
+                if NonCustomPropertyId::from(LonghandId::${sub_property.camel_case})
+                    .allowed_in_ignoring_rule_type(context) {
+                % endif
+                    declarations.push(PropertyDeclaration::${sub_property.camel_case}(
+                        longhands.${sub_property.ident}
+                    ));
+                % if sub_property.may_be_disabled_in(shorthand, engine):
+                }
+                % endif
+                % endfor
+            })
+        }
+
+        /// Try to serialize a given shorthand to a string.
+        pub fn to_css(declarations: &[&PropertyDeclaration], dest: &mut crate::str::CssStringWriter) -> fmt::Result {
+            match LonghandsToSerialize::from_iter(declarations.iter().cloned()) {
+                Ok(longhands) => longhands.to_css(&mut CssWriter::new(dest)),
+                Err(_) => Ok(())
+            }
+        }
+
+        ${caller.body()}
+    }
+    % endif
+</%def>
+
+// A shorthand of kind `<property-1> <property-2>?` where both properties have
+// the same type.
+<%def name="two_properties_shorthand(
+    name,
+    first_property,
+    second_property,
+    parser_function='crate::parser::Parse::parse',
+    **kwargs
+)">
+<%call expr="self.shorthand(name, sub_properties=' '.join([first_property, second_property]), **kwargs)">
+    #[allow(unused_imports)]
+    use crate::parser::Parse;
+    #[allow(unused_imports)]
+    use crate::values::specified;
+
+    fn parse_value<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Longhands, ParseError<'i>> {
+        let parse_one = |c: &ParserContext, input: &mut Parser<'i, 't>| -> Result<
+            crate::properties::longhands::${to_rust_ident(first_property)}::SpecifiedValue,
+            ParseError<'i>
+        > {
+            ${parser_function}(c, input)
+        };
+
+        let first = parse_one(context, input)?;
+        let second =
+            input.try_parse(|input| parse_one(context, input)).unwrap_or_else(|_| first.clone());
+        Ok(expanded! {
+            ${to_rust_ident(first_property)}: first,
+            ${to_rust_ident(second_property)}: second,
+        })
+    }
+
+    impl<'a> ToCss for LonghandsToSerialize<'a>  {
+        fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result where W: fmt::Write {
+            let first = &self.${to_rust_ident(first_property)};
+            let second = &self.${to_rust_ident(second_property)};
+
+            first.to_css(dest)?;
+            if first != second {
+                dest.write_char(' ')?;
+                second.to_css(dest)?;
+            }
+            Ok(())
+        }
+    }
+</%call>
+</%def>
+
+<%def name="four_sides_shorthand(name, sub_property_pattern,
+                                 parser_function='crate::parser::Parse::parse',
+                                 allow_quirks='No', **kwargs)">
+    <% sub_properties=' '.join(sub_property_pattern % side for side in PHYSICAL_SIDES) %>
+    <%call expr="self.shorthand(name, sub_properties=sub_properties, **kwargs)">
+        #[allow(unused_imports)]
+        use crate::parser::Parse;
+        use crate::values::generics::rect::Rect;
+        #[allow(unused_imports)]
+        use crate::values::specified;
+
+        fn parse_value<'i, 't>(
+            context: &ParserContext,
+            input: &mut Parser<'i, 't>,
+        ) -> Result<Longhands, ParseError<'i>> {
+            let rect = Rect::parse_with(context, input, |c, i| -> Result<
+                crate::properties::longhands::${to_rust_ident(sub_property_pattern % "top")}::SpecifiedValue,
+                ParseError<'i>
+            > {
+            % if allow_quirks != "No":
+                ${parser_function}_quirky(c, i, specified::AllowQuirks::${allow_quirks})
+            % else:
+                ${parser_function}(c, i)
+            % endif
+            })?;
+            Ok(expanded! {
+                % for index, side in enumerate(["top", "right", "bottom", "left"]):
+                    ${to_rust_ident(sub_property_pattern % side)}: rect.${index},
+                % endfor
+            })
+        }
+
+        impl<'a> ToCss for LonghandsToSerialize<'a> {
+            fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+            where
+                W: Write,
+            {
+                let rect = Rect::new(
+                    % for side in ["top", "right", "bottom", "left"]:
+                    &self.${to_rust_ident(sub_property_pattern % side)},
+                    % endfor
+                );
+                rect.to_css(dest)
+            }
+        }
+    </%call>
+</%def>