style: Add a ValueInfo trait for exposing types needed by devtools.

Most of types just derive it using proc_macro directly. Some of value
types need manual impl.

In my current plan, this new trait will be used in bug 1434130 to expose
values as well.

Bug: 1455576
Reviewed-by: emilio
MozReview-Commit-ID: LI7fy45VkRw

components/style/values/generics/background.rs

@@ -5,8 +5,8 @@
 //! Generic types for CSS values related to backgrounds.
 
 /// A generic value for the `background-size` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum BackgroundSize<LengthOrPercentageOrAuto> {
     /// `<width> <height>`
     Explicit {

components/style/values/generics/basic_shape.rs

@@ -18,7 +18,8 @@ pub type ClippingShape<BasicShape, Url> = ShapeSource<BasicShape, GeometryBox, U
 
 /// <https://drafts.fxtf.org/css-masking-1/#typedef-geometry-box>
 #[allow(missing_docs)]
-#[derive(Animate, Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, Copy, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum GeometryBox {
     FillBox,
     StrokeBox,
@@ -32,7 +33,8 @@ pub type FloatAreaShape<BasicShape, Image> = ShapeSource<BasicShape, ShapeBox, I
 /// https://drafts.csswg.org/css-shapes-1/#typedef-shape-box
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Animate, Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq,
+         SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum ShapeBox {
     MarginBox,
     BorderBox,
@@ -43,7 +45,8 @@ pub enum ShapeBox {
 /// A shape source, for some reference box.
 #[allow(missing_docs)]
 #[animation(no_bound(ImageOrUrl))]
-#[derive(Animate, Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
     #[animation(error)]
     ImageOrUrl(ImageOrUrl),
@@ -55,8 +58,8 @@ pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
 }
 
 #[allow(missing_docs)]
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToComputedValue,
-         ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum BasicShape<H, V, LengthOrPercentage> {
     Inset(#[css(field_bound)] InsetRect<LengthOrPercentage>),
     Circle(#[css(field_bound)] Circle<H, V, LengthOrPercentage>),
@@ -66,7 +69,8 @@ pub enum BasicShape<H, V, LengthOrPercentage> {
 
 /// <https://drafts.csswg.org/css-shapes/#funcdef-inset>
 #[allow(missing_docs)]
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToComputedValue)]
 pub struct InsetRect<LengthOrPercentage> {
     pub rect: Rect<LengthOrPercentage>,
     pub round: Option<BorderRadius<LengthOrPercentage>>,
@@ -74,8 +78,8 @@ pub struct InsetRect<LengthOrPercentage> {
 
 /// <https://drafts.csswg.org/css-shapes/#funcdef-circle>
 #[allow(missing_docs)]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue)]
 pub struct Circle<H, V, LengthOrPercentage> {
     pub position: Position<H, V>,
     pub radius: ShapeRadius<LengthOrPercentage>,
@@ -83,8 +87,8 @@ pub struct Circle<H, V, LengthOrPercentage> {
 
 /// <https://drafts.csswg.org/css-shapes/#funcdef-ellipse>
 #[allow(missing_docs)]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue)]
 pub struct Ellipse<H, V, LengthOrPercentage> {
     pub position: Position<H, V>,
     pub semiaxis_x: ShapeRadius<LengthOrPercentage>,
@@ -93,8 +97,8 @@ pub struct Ellipse<H, V, LengthOrPercentage> {
 
 /// <https://drafts.csswg.org/css-shapes/#typedef-shape-radius>
 #[allow(missing_docs)]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum ShapeRadius<LengthOrPercentage> {
     Length(LengthOrPercentage),
     #[animation(error)]
@@ -106,7 +110,8 @@ pub enum ShapeRadius<LengthOrPercentage> {
 /// A generic type for representing the `polygon()` function
 ///
 /// <https://drafts.csswg.org/css-shapes/#funcdef-polygon>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct Polygon<LengthOrPercentage> {
     /// The filling rule for a polygon.
     pub fill: FillRule,
@@ -120,7 +125,8 @@ pub struct Polygon<LengthOrPercentage> {
 // says that it can also be `inherit`
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq,
+         SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum FillRule {
     Nonzero,
     Evenodd,

components/style/values/generics/border.rs

@@ -10,7 +10,8 @@ use values::generics::rect::Rect;
 use values::generics::size::Size;
 
 /// A generic value for a single side of a `border-image-width` property.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum BorderImageSideWidth<LengthOrPercentage, Number> {
     /// `<length-or-percentage>`
     Length(LengthOrPercentage),
@@ -21,7 +22,8 @@ pub enum BorderImageSideWidth<LengthOrPercentage, Number> {
 }
 
 /// A generic value for the `border-image-slice` property.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct BorderImageSlice<NumberOrPercentage> {
     /// The offsets.
     pub offsets: Rect<NumberOrPercentage>,
@@ -30,8 +32,8 @@ pub struct BorderImageSlice<NumberOrPercentage> {
 }
 
 /// A generic value for the `border-*-radius` longhand properties.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub struct BorderCornerRadius<L>(#[css(field_bound)] pub Size<L>);
 
 impl<L> BorderCornerRadius<L> {
@@ -42,8 +44,9 @@ impl<L> BorderCornerRadius<L> {
 }
 
 /// A generic value for the `border-spacing` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub struct BorderSpacing<L>(#[css(field_bound)] pub Size<L>);
 
 impl<L> BorderSpacing<L> {
@@ -56,8 +59,8 @@ impl<L> BorderSpacing<L> {
 /// A generic value for `border-radius`, `outline-radius` and `inset()`.
 ///
 /// <https://drafts.csswg.org/css-backgrounds-3/#border-radius>
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue)]
 pub struct BorderRadius<LengthOrPercentage> {
     /// The top left radius.
     pub top_left: BorderCornerRadius<LengthOrPercentage>,

components/style/values/generics/box.rs

@@ -7,8 +7,8 @@
 use values::animated::ToAnimatedZero;
 
 /// A generic value for the `vertical-align` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum VerticalAlign<LengthOrPercentage> {
     /// `baseline`
     Baseline,
@@ -48,7 +48,8 @@ impl<L> ToAnimatedZero for VerticalAlign<L> {
 }
 
 /// https://drafts.csswg.org/css-animations/#animation-iteration-count
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum AnimationIterationCount<Number> {
     /// A `<number>` value.
     Number(Number),
@@ -57,8 +58,9 @@ pub enum AnimationIterationCount<Number> {
 }
 
 /// A generic value for the `perspective` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub enum Perspective<NonNegativeLength> {
     /// A non-negative length.
     Length(NonNegativeLength),

components/style/values/generics/column.rs

@@ -5,8 +5,9 @@
 //! Generic types for the column properties.
 
 /// A generic type for `column-count` values.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub enum ColumnCount<PositiveInteger> {
     /// A positive integer.
     Integer(PositiveInteger),

components/style/values/generics/counters.rs

@@ -11,7 +11,8 @@ use style_traits::{CssWriter, ToCss};
 use values::CustomIdent;
 
 /// A generic value for the `counter-increment` property.
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub struct CounterIncrement<I>(Counters<I>);
 
 impl<I> CounterIncrement<I> {
@@ -32,7 +33,8 @@ impl<I> Deref for CounterIncrement<I> {
 }
 
 /// A generic value for the `counter-reset` property.
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub struct CounterReset<I>(Counters<I>);
 
 impl<I> CounterReset<I> {
@@ -55,7 +57,8 @@ impl<I> Deref for CounterReset<I> {
 /// A generic value for lists of counters.
 ///
 /// Keyword `none` is represented by an empty vector.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct Counters<I>(Box<[(CustomIdent, I)]>);
 
 impl<I> Default for Counters<I> {

components/style/values/generics/effects.rs

@@ -10,7 +10,8 @@ use style_traits::values::{CssWriter, SequenceWriter, ToCss};
 use values::specified::url::SpecifiedUrl;
 
 /// A generic value for a single `box-shadow`.
-#[derive(Animate, Clone, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToAnimatedZero)]
+#[derive(Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToAnimatedValue, ToAnimatedZero)]
 pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
     /// The base shadow.
     pub base: SimpleShadow<Color, SizeLength, BlurShapeLength>,
@@ -23,8 +24,8 @@ pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
 
 /// A generic value for a single `filter`.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToComputedValue, ToCss)]
 pub enum Filter<Angle, Factor, Length, DropShadow> {
     /// `blur(<length>)`
     #[css(function)]
@@ -66,8 +67,8 @@ pub enum Filter<Angle, Factor, Length, DropShadow> {
 ///
 /// Contrary to the canonical order from the spec, the color is serialised
 /// first, like in Gecko and Webkit.
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToAnimatedZero, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero, ToCss)]
 pub struct SimpleShadow<Color, SizeLength, ShapeLength> {
     /// Color.
     pub color: Color,

components/style/values/generics/flex.rs

@@ -6,8 +6,9 @@
 
 /// A generic value for the `flex-basis` property.
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, PartialEq, ToAnimatedValue,
-         ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero, ToComputedValue,
+         ToCss)]
 pub enum FlexBasis<Width> {
     /// `content`
     Content,

components/style/values/generics/font.rs

@@ -11,11 +11,12 @@ use num_traits::One;
 use parser::{Parse, ParserContext};
 use std::fmt::{self, Write};
 use std::io::Cursor;
-use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
+use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 use values::distance::{ComputeSquaredDistance, SquaredDistance};
 
 /// https://drafts.csswg.org/css-fonts-4/#feature-tag-value
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct FeatureTagValue<Integer> {
     /// A four-character tag, packed into a u32 (one byte per character).
     pub tag: FontTag,
@@ -45,7 +46,8 @@ where
 /// Variation setting for a single feature, see:
 ///
 /// https://drafts.csswg.org/css-fonts-4/#font-variation-settings-def
-#[derive(Animate, Clone, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub struct VariationValue<Number> {
     /// A four-character tag, packed into a u32 (one byte per character).
     #[animation(constant)]
@@ -69,7 +71,8 @@ where
 
 /// A value both for font-variation-settings and font-feature-settings.
 #[css(comma)]
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub struct FontSettings<T>(#[css(if_empty = "normal", iterable)] pub Box<[T]>);
 
 impl<T> FontSettings<T> {
@@ -105,7 +108,8 @@ impl<T: Parse> Parse for FontSettings<T> {
 ///   https://drafts.csswg.org/css-fonts-4/#font-variation-settings-def
 ///   https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-feature-settings
 ///
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct FontTag(pub u32);
 
 impl ToCss for FontTag {
@@ -177,9 +181,13 @@ where
     }
 }
 
+impl<Length> SpecifiedValueInfo for KeywordInfo<Length> {
+    const SUPPORTED_TYPES: u8 = <KeywordSize as SpecifiedValueInfo>::SUPPORTED_TYPES;
+}
+
 /// CSS font keywords
 #[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToAnimatedZero)]
+         ToAnimatedValue, ToAnimatedZero, SpecifiedValueInfo)]
 #[allow(missing_docs)]
 pub enum KeywordSize {
     XXSmall,

components/style/values/generics/gecko.rs

@@ -7,7 +7,8 @@
 
 /// A generic value for scroll snap points.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue,
+         ToCss)]
 pub enum ScrollSnapPoint<LengthOrPercentage> {
     /// `none`
     None,

components/style/values/generics/grid.rs

@@ -18,7 +18,8 @@ use values::specified::grid::parse_line_names;
 /// A `<grid-line>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-grid-row-start-grid-line>
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct GridLine<Integer> {
     /// Flag to check whether it's a `span` keyword.
     pub is_span: bool,
@@ -148,7 +149,8 @@ impl Parse for GridLine<specified::Integer> {
 
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq,
+         SpecifiedValueInfo, ToComputedValue, ToCss)]
 pub enum TrackKeyword {
     Auto,
     MaxContent,
@@ -159,7 +161,8 @@ pub enum TrackKeyword {
 /// avoid re-implementing it for the computed type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-breadth>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum TrackBreadth<L> {
     /// The generic type is almost always a non-negative `<length-percentage>`
     Breadth(L),
@@ -187,7 +190,7 @@ impl<L> TrackBreadth<L> {
 /// generic only to avoid code bloat. It only takes `<length-percentage>`
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-size>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo)]
 pub enum TrackSize<L> {
     /// A flexible `<track-breadth>`
     Breadth(TrackBreadth<L>),
@@ -343,7 +346,8 @@ where
 /// The initial argument of the `repeat` function.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-repeat>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum RepeatCount<Integer> {
     /// A positive integer. This is allowed only for `<track-repeat>` and `<fixed-repeat>`
     Number(Integer),
@@ -378,7 +382,8 @@ impl Parse for RepeatCount<specified::Integer> {
 ///
 /// It can also hold `repeat()` function parameters, which expands into the respective
 /// values in its computed form.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct TrackRepeat<L, I> {
     /// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
     pub count: RepeatCount<I>,
@@ -464,7 +469,8 @@ impl<L: Clone> TrackRepeat<L, specified::Integer> {
 }
 
 /// Track list values. Can be <track-size> or <track-repeat>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum TrackListValue<LengthOrPercentage, Integer> {
     /// A <track-size> value.
     TrackSize(TrackSize<LengthOrPercentage>),
@@ -475,7 +481,8 @@ pub enum TrackListValue<LengthOrPercentage, Integer> {
 /// The type of a `<track-list>` as determined during parsing.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub enum TrackListType {
     /// [`<auto-track-list>`](https://drafts.csswg.org/css-grid/#typedef-auto-track-list)
     ///
@@ -497,7 +504,7 @@ pub enum TrackListType {
 /// A grid `<track-list>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo)]
 pub struct TrackList<LengthOrPercentage, Integer> {
     /// The type of this `<track-list>` (auto, explicit or general).
     ///
@@ -569,7 +576,8 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
 ///
 /// `subgrid [ <line-names> | repeat(<positive-integer> | auto-fill, <line-names>+) ]+`
 /// Old spec: https://www.w3.org/TR/2015/WD-css-grid-1-20150917/#typedef-line-name-list
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct LineNameList {
     /// The optional `<line-name-list>`
     pub names: Box<[Box<[CustomIdent]>]>,
@@ -672,7 +680,8 @@ impl ToCss for LineNameList {
 /// Variants for `<grid-template-rows> | <grid-template-columns>`
 /// Subgrid deferred to Level 2 spec due to lack of implementation.
 /// But it's implemented in gecko, so we have to as well.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum GridTemplateComponent<L, I> {
     /// `none` value.
     None,

components/style/values/generics/image.rs

@@ -16,7 +16,7 @@ use values::serialize_atom_identifier;
 /// An [image].
 ///
 /// [image]: https://drafts.csswg.org/css-images/#image-values
-#[derive(Clone, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
 pub enum Image<Gradient, MozImageRect, ImageUrl> {
     /// A `<url()>` image.
     Url(ImageUrl),
@@ -164,7 +164,8 @@ impl ToCss for PaintWorklet {
 /// `-moz-image-rect(<uri>, top, right, bottom, left);`
 #[allow(missing_docs)]
 #[css(comma, function)]
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub struct MozImageRect<NumberOrPercentage, MozImageRectUrl> {
     pub url: MozImageRectUrl,
     pub top: NumberOrPercentage,

components/style/values/generics/mod.rs

@@ -79,7 +79,8 @@ impl SymbolsType {
 /// Since wherever <counter-style> is used, 'none' is a valid value as
 /// well, we combine them into one type to make code simpler.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Eq, PartialEq, SpecifiedValueInfo, ToComputedValue,
+         ToCss)]
 pub enum CounterStyleOrNone {
     /// `none`
     None,
@@ -139,12 +140,14 @@ impl Parse for CounterStyleOrNone {
 
 /// A wrapper of Non-negative values.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         PartialOrd, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, PartialOrd, SpecifiedValueInfo, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub struct NonNegative<T>(pub T);
 
 /// A wrapper of greater-than-or-equal-to-one values.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         PartialOrd, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, PartialOrd, SpecifiedValueInfo, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub struct GreaterThanOrEqualToOne<T>(pub T);

components/style/values/generics/pointing.rs

@@ -9,8 +9,9 @@ use style_traits::{CssWriter, ToCss};
 use style_traits::cursor::CursorKind;
 
 /// A generic value for the `caret-color` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub enum CaretColor<Color> {
     /// An explicit color.
     Color(Color),
@@ -21,7 +22,8 @@ pub enum CaretColor<Color> {
 /// A generic value for the `cursor` property.
 ///
 /// https://drafts.csswg.org/css-ui/#cursor
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct Cursor<Image> {
     /// The parsed images for the cursor.
     pub images: Box<[Image]>,
@@ -54,7 +56,8 @@ impl<Image: ToCss> ToCss for Cursor<Image> {
 }
 
 /// A generic value for item of `image cursors`.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue)]
 pub struct CursorImage<ImageUrl, Number> {
     /// The url to parse images from.
     pub url: ImageUrl,

components/style/values/generics/position.rs

@@ -6,8 +6,8 @@
 //! [`position`](https://drafts.csswg.org/css-backgrounds-3/#position)
 
 /// A generic type for representing a CSS [position](https://drafts.csswg.org/css-values/#position).
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedZero, ToComputedValue)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedZero, ToComputedValue)]
 pub struct Position<H, V> {
     /// The horizontal component of position.
     pub horizontal: H,
@@ -26,8 +26,8 @@ impl<H, V> Position<H, V> {
 }
 
 /// A generic value for the `z-index` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedZero, ToComputedValue, ToCss)]
 pub enum ZIndex<Integer> {
     /// An integer value.
     Integer(Integer),

components/style/values/generics/rect.rs

@@ -11,8 +11,8 @@ use style_traits::{CssWriter, ParseError, ToCss};
 
 /// A CSS value made of four components, where its `ToCss` impl will try to
 /// serialize as few components as possible, like for example in `border-width`.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToComputedValue)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToComputedValue)]
 pub struct Rect<T>(pub T, pub T, pub T, pub T);
 
 impl<T> Rect<T> {

components/style/values/generics/size.rs

@@ -8,7 +8,7 @@ use cssparser::Parser;
 use euclid::Size2D;
 use parser::ParserContext;
 use std::fmt::{self, Write};
-use style_traits::{CssWriter, ParseError, ToCss};
+use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, ToCss};
 use values::animated::ToAnimatedValue;
 
 /// A generic size, for `border-*-radius` longhand properties, or
@@ -93,3 +93,7 @@ where
         ))
     }
 }
+
+impl<L: SpecifiedValueInfo> SpecifiedValueInfo for Size<L> {
+    const SUPPORTED_TYPES: u8 = L::SUPPORTED_TYPES;
+}

components/style/values/generics/svg.rs

@@ -16,8 +16,8 @@ use values::distance::{ComputeSquaredDistance, SquaredDistance};
 ///
 /// <https://www.w3.org/TR/SVG2/painting.html#SpecifyingPaint>
 #[animation(no_bound(UrlPaintServer))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToComputedValue, ToCss)]
 pub struct SVGPaint<ColorType, UrlPaintServer> {
     /// The paint source
     pub kind: SVGPaintKind<ColorType, UrlPaintServer>,
@@ -31,8 +31,9 @@ pub struct SVGPaint<ColorType, UrlPaintServer> {
 /// to have a fallback, Gecko lets the context
 /// properties have a fallback as well.
 #[animation(no_bound(UrlPaintServer))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero, ToComputedValue,
+         ToCss)]
 pub enum SVGPaintKind<ColorType, UrlPaintServer> {
     /// `none`
     #[animation(error)]
@@ -112,8 +113,8 @@ impl<ColorType: Parse, UrlPaintServer: Parse> Parse for SVGPaint<ColorType, UrlP
 
 /// A value of <length> | <percentage> | <number> for svg which allow unitless length.
 /// <https://www.w3.org/TR/SVG11/painting.html#StrokeProperties>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToAnimatedZero,
-         ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
 pub enum SvgLengthOrPercentageOrNumber<LengthOrPercentage, Number> {
     /// <length> | <percentage>
     LengthOrPercentage(LengthOrPercentage),
@@ -190,8 +191,9 @@ impl<LengthOrPercentageType: Parse, NumberType: Parse> Parse
 }
 
 /// An SVG length value supports `context-value` in addition to length.
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero, ToComputedValue,
+         ToCss)]
 pub enum SVGLength<LengthType> {
     /// `<length> | <percentage> | <number>`
     Length(LengthType),
@@ -200,8 +202,8 @@ pub enum SVGLength<LengthType> {
 }
 
 /// Generic value for stroke-dasharray.
-#[derive(Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToComputedValue, ToCss)]
 pub enum SVGStrokeDashArray<LengthType> {
     /// `[ <length> | <percentage> | <number> ]#`
     #[css(comma)]
@@ -216,8 +218,8 @@ pub enum SVGStrokeDashArray<LengthType> {
 
 /// An SVG opacity value accepts `context-{fill,stroke}-opacity` in
 /// addition to opacity value.
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedZero,
-         ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedZero, ToComputedValue, ToCss)]
 pub enum SVGOpacity<OpacityType> {
     /// `<opacity-value>`
     Opacity(OpacityType),

components/style/values/generics/text.rs

@@ -12,7 +12,8 @@ use values::animated::{Animate, Procedure, ToAnimatedZero};
 use values::distance::{ComputeSquaredDistance, SquaredDistance};
 
 /// A generic value for the `initial-letter` property.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum InitialLetter<Number, Integer> {
     /// `normal`
     Normal,
@@ -29,7 +30,8 @@ impl<N, I> InitialLetter<N, I> {
 }
 
 /// A generic spacing value for the `letter-spacing` and `word-spacing` properties.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum Spacing<Value> {
     /// `normal`
     Normal,
@@ -110,8 +112,8 @@ where
 }
 
 /// A generic value for the `line-height` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToCss)]
 pub enum LineHeight<Number, LengthOrPercentage> {
     /// `normal`
     Normal,
@@ -140,8 +142,9 @@ impl<N, L> LineHeight<N, L> {
 }
 
 /// A generic value for the `-moz-tab-size` property.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero,
+         ToComputedValue, ToCss)]
 pub enum MozTabSize<Number, Length> {
     /// A number.
     Number(Number),

components/style/values/generics/transform.rs

@@ -15,7 +15,8 @@ use values::specified::length::LengthOrPercentage as SpecifiedLengthOrPercentage
 
 /// A generic 2D transformation matrix.
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 #[css(comma, function)]
 pub struct Matrix<T> {
     pub a: T,
@@ -29,7 +30,8 @@ pub struct Matrix<T> {
 #[allow(missing_docs)]
 #[cfg_attr(rustfmt, rustfmt_skip)]
 #[css(comma, function = "matrix3d")]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub struct Matrix3D<T> {
     pub m11: T, pub m12: T, pub m13: T, pub m14: T,
     pub m21: T, pub m22: T, pub m23: T, pub m24: T,
@@ -64,8 +66,8 @@ impl<T: Into<f64>> From<Matrix3D<T>> for Transform3D<f64> {
 }
 
 /// A generic transform origin.
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
-         ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf,
+         PartialEq, SpecifiedValueInfo, ToAnimatedZero, ToComputedValue, ToCss)]
 pub struct TransformOrigin<H, V, Depth> {
     /// The horizontal origin.
     pub horizontal: H,
@@ -157,7 +159,8 @@ impl TimingKeyword {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 /// A single operation in the list of a `transform` value
 pub enum TransformOperation<Angle, Number, Length, Integer, LengthOrPercentage> {
     /// Represents a 2D 2x3 matrix.
@@ -261,7 +264,8 @@ pub enum TransformOperation<Angle, Number, Length, Integer, LengthOrPercentage>
     },
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 /// A value of the `transform` property
 pub struct Transform<T>(#[css(if_empty = "none", iterable)] pub Vec<T>);
 
@@ -554,8 +558,8 @@ pub fn get_normalized_vector_and_angle<T: Zero>(
     }
 }
 
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedZero,
-         ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedZero, ToComputedValue, ToCss)]
 /// A value of the `Rotate` property
 ///
 /// <https://drafts.csswg.org/css-transforms-2/#individual-transforms>
@@ -568,8 +572,8 @@ pub enum Rotate<Number, Angle> {
     Rotate3D(Number, Number, Number, Angle),
 }
 
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedZero,
-         ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedZero, ToComputedValue, ToCss)]
 /// A value of the `Scale` property
 ///
 /// <https://drafts.csswg.org/css-transforms-2/#individual-transforms>
@@ -584,8 +588,8 @@ pub enum Scale<Number> {
     Scale3D(Number, Number, Number),
 }
 
-#[derive(Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedZero,
-         ToComputedValue, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedZero, ToComputedValue, ToCss)]
 /// A value of the `Translate` property
 ///
 /// <https://drafts.csswg.org/css-transforms-2/#individual-transforms>
@@ -601,7 +605,8 @@ pub enum Translate<LengthOrPercentage, Length> {
 }
 
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo,
+         ToComputedValue, ToCss)]
 pub enum TransformStyle {
     #[cfg(feature = "servo")]
     Auto,

components/style/values/generics/url.rs

@@ -9,8 +9,9 @@ use parser::{Parse, ParserContext};
 use style_traits::ParseError;
 
 /// An image url or none, used for example in list-style-image
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-         ToAnimatedZero, ToComputedValue, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug, MallocSizeOf, PartialEq,
+         SpecifiedValueInfo, ToAnimatedValue, ToAnimatedZero, ToComputedValue,
+         ToCss)]
 pub enum UrlOrNone<Url> {
     /// `none`
     None,