style: Move overflow to use cbindgen.

It's one of the most annoying / hacky mako bits we have.

Differential Revision: https://phabricator.services.mozilla.com/D14084

components/style/cbindgen.toml

@@ -64,5 +64,6 @@ include = [
   "ScrollSnapType",
   "OverflowClipBox",
   "Resize",
+  "Overflow",
 ]
 item_types = ["enums", "structs", "typedefs"]

components/style/properties/data.py

@@ -325,6 +325,7 @@ class Longhand(object):
                 "NonNegativeNumber",
                 "Opacity",
                 "OutlineStyle",
+                "Overflow",
                 "OverflowClipBox",
                 "OverflowWrap",
                 "OverscrollBehavior",

components/style/properties/gecko.mako.rs

@@ -1394,6 +1394,7 @@ impl Clone for ${style_struct.gecko_struct_name} {
         "OverflowClipBox": impl_simple,
         "ScrollSnapType": impl_simple,
         "Float": impl_simple,
+        "Overflow": impl_simple,
         "BreakBetween": impl_simple,
         "BreakWithin": impl_simple,
         "Resize": impl_simple,
@@ -3011,7 +3012,7 @@ fn static_assert() {
     }
 </%def>
 
-<% skip_box_longhands= """display overflow-y vertical-align
+<% skip_box_longhands= """display vertical-align
                           animation-name animation-delay animation-duration
                           animation-direction animation-fill-mode animation-play-state
                           animation-iteration-count animation-timing-function
@@ -3063,28 +3064,6 @@ fn static_assert() {
     ) %>
     ${impl_keyword('clear', 'mBreakType', clear_keyword)}
 
-    <% overflow_x = data.longhands_by_name["overflow-x"] %>
-    pub fn set_overflow_y(&mut self, v: longhands::overflow_y::computed_value::T) {
-        use crate::properties::longhands::overflow_x::computed_value::T as BaseType;
-        // FIXME(bholley): Align binary representations and ditch |match| for cast + static_asserts
-        self.gecko.mOverflowY = match v {
-            % for value in overflow_x.keyword.values_for('gecko'):
-                BaseType::${to_camel_case(value)} => structs::${overflow_x.keyword.gecko_constant(value)} as u8,
-            % endfor
-        };
-    }
-    ${impl_simple_copy('overflow_y', 'mOverflowY')}
-    pub fn clone_overflow_y(&self) -> longhands::overflow_y::computed_value::T {
-        use crate::properties::longhands::overflow_x::computed_value::T as BaseType;
-        // FIXME(bholley): Align binary representations and ditch |match| for cast + static_asserts
-        match self.gecko.mOverflowY as u32 {
-            % for value in overflow_x.keyword.values_for('gecko'):
-            structs::${overflow_x.keyword.gecko_constant(value)} => BaseType::${to_camel_case(value)},
-            % endfor
-            x => panic!("Found unexpected value in style struct for overflow_y property: {}", x),
-        }
-    }
-
     pub fn set_vertical_align(&mut self, v: longhands::vertical_align::computed_value::T) {
         use crate::values::generics::box_::VerticalAlign;
         let value = match v {

components/style/properties/longhands/box.mako.rs

@@ -100,34 +100,30 @@ ${helpers.single_keyword("-servo-overflow-clip-box", "padding-box content-box",
     )}
 % endfor
 
-<%
-    overflow_custom_consts = { "-moz-hidden-unscrollable": "CLIP" }
-%>
-
 // FIXME(pcwalton, #2742): Implement scrolling for `scroll` and `auto`.
 //
 // We allow it to apply to placeholders for UA sheets, which set it !important.
-${helpers.single_keyword(
+${helpers.predefined_type(
     "overflow-x",
-    "visible hidden scroll auto",
+    "Overflow",
+    "computed::Overflow::Visible",
     animation_value_type="discrete",
-    extra_gecko_values="-moz-hidden-unscrollable",
-    custom_consts=overflow_custom_consts,
-    gecko_constant_prefix="NS_STYLE_OVERFLOW",
     flags="APPLIES_TO_PLACEHOLDER",
     spec="https://drafts.csswg.org/css-overflow/#propdef-overflow-x",
+    needs_context=False,
     servo_restyle_damage = "reflow",
 )}
 
-// FIXME(pcwalton, #2742): Implement scrolling for `scroll` and `auto`.
-//
-// We allow it to apply to placeholders for UA sheets, which set it !important.
-<%helpers:longhand name="overflow-y" animation_value_type="discrete"
-                   flags="APPLIES_TO_PLACEHOLDER",
-                   spec="https://drafts.csswg.org/css-overflow/#propdef-overflow-y"
-                   servo_restyle_damage = "reflow">
-    pub use super::overflow_x::{SpecifiedValue, parse, get_initial_value, computed_value};
-</%helpers:longhand>
+${helpers.predefined_type(
+    "overflow-y",
+    "Overflow",
+    "computed::Overflow::Visible",
+    animation_value_type="discrete",
+    flags="APPLIES_TO_PLACEHOLDER",
+    spec="https://drafts.csswg.org/css-overflow/#propdef-overflow-y",
+    needs_context=False,
+    servo_restyle_damage = "reflow",
+)}
 
 <% transition_extra_prefixes = "moz:layout.css.prefixes.transitions webkit" %>
 

components/style/values/computed/box.rs

@@ -13,7 +13,7 @@ use crate::values::specified::box_ as specified;
 
 pub use crate::values::specified::box_::{AnimationName, Appearance, BreakBetween, BreakWithin};
 pub use crate::values::specified::box_::{Clear as SpecifiedClear, Float as SpecifiedFloat};
-pub use crate::values::specified::box_::{Contain, Display, OverflowClipBox};
+pub use crate::values::specified::box_::{Contain, Display, Overflow, OverflowClipBox};
 pub use crate::values::specified::box_::{OverscrollBehavior, ScrollSnapType};
 pub use crate::values::specified::box_::{TouchAction, TransitionProperty, WillChange};
 

components/style/values/computed/mod.rs

@@ -43,7 +43,7 @@ pub use self::border::{BorderImageRepeat, BorderImageSideWidth};
 pub use self::border::{BorderImageSlice, BorderImageWidth};
 pub use self::box_::{AnimationIterationCount, AnimationName, Contain};
 pub use self::box_::{Appearance, BreakBetween, BreakWithin, Clear, Float};
-pub use self::box_::{Display, TransitionProperty};
+pub use self::box_::{Display, TransitionProperty, Overflow};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
 pub use self::box_::{ScrollSnapType, TouchAction, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorPropertyValue, RGBAColor};

components/style/values/specified/box.rs

@@ -1363,3 +1363,28 @@ pub enum BreakWithin {
     Auto,
     Avoid,
 }
+
+/// The value for the `overflow-x` / `overflow-y` properties.
+#[allow(missing_docs)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    Hash,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToCss,
+    ToComputedValue,
+)]
+#[repr(u8)]
+pub enum Overflow {
+    Visible,
+    Hidden,
+    Scroll,
+    Auto,
+    #[cfg(feature = "gecko")]
+    MozHiddenUnscrollable,
+}

components/style/values/specified/mod.rs

@@ -36,7 +36,7 @@ pub use self::border::{BorderCornerRadius, BorderImageSlice, BorderImageWidth};
 pub use self::border::{BorderImageRepeat, BorderImageSideWidth};
 pub use self::border::{BorderRadius, BorderSideWidth, BorderSpacing, BorderStyle};
 pub use self::box_::{AnimationIterationCount, AnimationName, Contain, Display};
-pub use self::box_::{Appearance, BreakBetween, BreakWithin, Clear, Float};
+pub use self::box_::{Appearance, BreakBetween, BreakWithin, Clear, Float, Overflow};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
 pub use self::box_::{ScrollSnapType, TouchAction, TransitionProperty, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorPropertyValue, RGBAColor};