Auto merge of #12465 - Manishearth:stylo-calc, r=heycam

Add bindings for calc()

This adds bindings for dealing with refcounted calc() values.

So far we can get/set them, but we don't yet have the ability to copy them around. I'll work on that next.

Corresponding gecko bindings at https://github.com/servo/gecko-dev/compare/stylo...Manishearth:stylo-calc?expand=1

f? @emilio @heycam

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components/style/gecko_conversions.rs

@@ -0,0 +1,36 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+//! This module contains conversion helpers between Servo and Gecko types
+//! Ideally, it would be in geckolib itself, but coherence
+//! forces us to keep the traits and implementations here
+
+use app_units::Au;
+use gecko_bindings::structs::nsStyleCoord_CalcValue;
+use values::computed::CalcLengthOrPercentage;
+
+impl From<CalcLengthOrPercentage> for nsStyleCoord_CalcValue {
+    fn from(other: CalcLengthOrPercentage) -> nsStyleCoord_CalcValue {
+        let has_percentage = other.percentage.is_some();
+        nsStyleCoord_CalcValue {
+            mLength: other.length.map_or(0, |l| l.0),
+            mPercent: other.percentage.unwrap_or(0.0),
+            mHasPercent: has_percentage,
+        }
+    }
+}
+
+impl From<nsStyleCoord_CalcValue> for CalcLengthOrPercentage {
+    fn from(other: nsStyleCoord_CalcValue) -> CalcLengthOrPercentage {
+        let percentage = if other.mHasPercent {
+            Some(other.mPercent)
+        } else {
+            None
+        };
+        CalcLengthOrPercentage {
+            length: Some(Au(other.mLength)),
+            percentage: percentage,
+        }
+    }
+}

components/style/lib.rs

@@ -81,6 +81,8 @@ pub mod dom;
 pub mod element_state;
 pub mod error_reporting;
 pub mod font_face;
+#[cfg(feature = "gecko")]
+pub mod gecko_conversions;
 pub mod keyframes;
 pub mod logical_geometry;
 pub mod matching;

ports/geckolib/gecko_bindings/bindings.rs

@@ -123,6 +123,16 @@ unsafe impl Sync for nsStyleImageLayers {}
 impl HeapSizeOf for nsStyleImageLayers { fn heap_size_of_children(&self) -> usize { 0 } }
 use structs::nsStyleImageLayers_Layer as Layer;
 use structs::nsStyleImageLayers_LayerType as LayerType;
+use structs::nsStyleUnit;
+unsafe impl Send for nsStyleUnit {}
+unsafe impl Sync for nsStyleUnit {}
+impl HeapSizeOf for nsStyleUnit { fn heap_size_of_children(&self) -> usize { 0 } }
+use structs::nsStyleUnion;
+unsafe impl Send for nsStyleUnion {}
+unsafe impl Sync for nsStyleUnion {}
+impl HeapSizeOf for nsStyleUnion { fn heap_size_of_children(&self) -> usize { 0 } }
+use structs::nsStyleCoord_CalcValue as CalcValue;
+use structs::nsStyleCoord_Calc as Calc;
 use structs::SheetParsingMode;
 use structs::nsMainThreadPtrHandle;
 use structs::nsMainThreadPtrHolder;
@@ -255,6 +265,13 @@ extern "C" {
                                          len: usize);
     pub fn Gecko_InitializeImageLayer(layer: *mut Layer,
                                       layer_type: LayerType);
+    pub fn Gecko_ResetStyleCoord(unit: *mut nsStyleUnit,
+                                 value: *mut nsStyleUnion);
+    pub fn Gecko_SetStyleCoordCalcValue(unit: *mut nsStyleUnit,
+                                        value: *mut nsStyleUnion,
+                                        calc: CalcValue);
+    pub fn Gecko_AddRefCalcArbitraryThread(aPtr: *mut Calc);
+    pub fn Gecko_ReleaseCalcArbitraryThread(aPtr: *mut Calc);
     pub fn Servo_StylesheetFromUTF8Bytes(bytes: *const u8, length: u32,
                                          parsing_mode: SheetParsingMode,
                                          base: *mut ThreadSafeURIHolder,

ports/geckolib/gecko_bindings/structs_debug.rs

@@ -4885,12 +4885,11 @@ fn bindgen_test_layout_nsStyleCoord_CalcValue() {
 #[derive(Debug)]
 pub struct nsStyleCoord_Calc {
     pub _base: nsStyleCoord_CalcValue,
-    pub mRefCnt: nsAutoRefCnt,
-    pub _mOwningThread: nsAutoOwningThread,
+    pub mRefCnt: ThreadSafeAutoRefCnt,
 }
 #[test]
 fn bindgen_test_layout_nsStyleCoord_Calc() {
-    assert_eq!(::std::mem::size_of::<nsStyleCoord_Calc>() , 32usize);
+    assert_eq!(::std::mem::size_of::<nsStyleCoord_Calc>() , 24usize);
     assert_eq!(::std::mem::align_of::<nsStyleCoord_Calc>() , 8usize);
 }
 #[repr(u32)]

ports/geckolib/gecko_bindings/structs_release.rs

@@ -4864,12 +4864,11 @@ fn bindgen_test_layout_nsStyleCoord_CalcValue() {
 #[derive(Debug)]
 pub struct nsStyleCoord_Calc {
     pub _base: nsStyleCoord_CalcValue,
-    pub mRefCnt: nsAutoRefCnt,
-    pub _mOwningThread: nsAutoOwningThread,
+    pub mRefCnt: ThreadSafeAutoRefCnt,
 }
 #[test]
 fn bindgen_test_layout_nsStyleCoord_Calc() {
-    assert_eq!(::std::mem::size_of::<nsStyleCoord_Calc>() , 32usize);
+    assert_eq!(::std::mem::size_of::<nsStyleCoord_Calc>() , 24usize);
     assert_eq!(::std::mem::align_of::<nsStyleCoord_Calc>() , 8usize);
 }
 #[repr(u32)]

ports/geckolib/gecko_bindings/sugar/mod.rs

@@ -3,4 +3,5 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 mod ns_style_auto_array;
+mod ns_style_coord;
 mod ns_t_array;

ports/geckolib/gecko_bindings/sugar/ns_style_coord.rs

@@ -0,0 +1,54 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+use bindings::{Gecko_ResetStyleCoord, Gecko_SetStyleCoordCalcValue, Gecko_AddRefCalcArbitraryThread};
+use std::mem::transmute;
+use structs::{nsStyleCoord_CalcValue, nsStyleCoord_Calc, nsStyleUnit, nsStyleUnion, nsStyleCoord};
+
+// Functions here are unsafe because it is possible to use the wrong nsStyleUnit
+// FIXME we should be pairing up nsStyleUnion and nsStyleUnit somehow
+// nsStyleCoord is one way to do it, but there are other structs using pairs
+// of union and unit too
+
+impl nsStyleUnion {
+    /// Clean up any resources used by an nsStyleUnit
+    /// Currently, this only happens if the nsStyleUnit
+    /// is a Calc
+    pub unsafe fn reset(&mut self, unit: &mut nsStyleUnit) {
+        if *unit == nsStyleUnit::eStyleUnit_Calc {
+            Gecko_ResetStyleCoord(unit, self);
+        }
+    }
+
+    /// Set internal value to a calc() value
+    /// reset() the union before calling this
+    pub unsafe fn set_calc_value(&mut self, unit: &mut nsStyleUnit, v: nsStyleCoord_CalcValue) {
+        // Calc should have been cleaned up
+        debug_assert!(*unit != nsStyleUnit::eStyleUnit_Calc);
+        Gecko_SetStyleCoordCalcValue(unit, self, v);
+    }
+
+    pub unsafe fn get_calc(&self) -> nsStyleCoord_CalcValue {
+        (*self.as_calc())._base
+    }
+
+    pub unsafe fn addref_if_calc(&mut self, unit: &nsStyleUnit) {
+        if *unit == nsStyleUnit::eStyleUnit_Calc {
+            Gecko_AddRefCalcArbitraryThread(self.as_calc_mut());
+        }
+    }
+
+    unsafe fn as_calc_mut(&mut self) -> &mut nsStyleCoord_Calc {
+        transmute(*self.mPointer.as_mut() as *mut nsStyleCoord_Calc)
+    }
+    unsafe fn as_calc(&self) -> &nsStyleCoord_Calc {
+        transmute(*self.mPointer.as_ref() as *const nsStyleCoord_Calc)
+    }
+}
+
+impl nsStyleCoord {
+    pub unsafe fn addref_if_calc(&mut self) {
+        self.mValue.addref_if_calc(&self.mUnit);
+    }
+}

ports/geckolib/gecko_bindings/tools/regen.py

@@ -121,6 +121,8 @@ COMPILATION_TARGETS = {
             "nsStyleEffects", "nsStyleImage", "nsStyleGradient",
             "nsStyleCoord", "nsStyleGradientStop", "nsStyleImageLayers",
             "nsStyleImageLayers::Layer", "nsStyleImageLayers::LayerType",
+            "nsStyleUnit", "nsStyleUnion", "nsStyleCoord::CalcValue",
+            "nsStyleCoord::Calc",
 
             "SheetParsingMode", "nsMainThreadPtrHandle",
             "nsMainThreadPtrHolder", "nscolor", "nsFont", "FontFamilyList",

ports/geckolib/properties.mako.rs

@@ -35,7 +35,7 @@ use style::properties::{CascadePropertyFn, ServoComputedValues, ComputedValues};
 use style::properties::longhands;
 use style::properties::style_struct_traits::*;
 use values::{StyleCoordHelpers, GeckoStyleCoordConvertible, convert_nscolor_to_rgba};
-use values::{convert_rgba_to_nscolor, debug_assert_unit_is_safe_to_copy};
+use values::convert_rgba_to_nscolor;
 use values::round_border_to_device_pixels;
 
 #[derive(Clone, Debug)]
@@ -317,9 +317,10 @@ def set_gecko_property(ffi_name, expr):
                                &mut self.gecko.${union_ffi_name});
     }
     fn copy_${ident}_from(&mut self, other: &Self) {
-        debug_assert_unit_is_safe_to_copy(self.gecko.${unit_ffi_name});
+        unsafe { self.gecko.${union_ffi_name}.reset(&mut self.gecko.${unit_ffi_name}) };
         self.gecko.${unit_ffi_name} =  other.gecko.${unit_ffi_name};
         self.gecko.${union_ffi_name} = other.gecko.${union_ffi_name};
+        unsafe { self.gecko.${union_ffi_name}.addref_if_calc(&self.gecko.${unit_ffi_name}) };
     }
     % if need_clone:
         fn clone_${ident}(&self) -> longhands::${ident}::computed_value::T {
@@ -347,12 +348,14 @@ ${impl_split_style_coord(ident,
                                         &mut self.gecko.${y_union_ffi_name});
     }
     fn copy_${ident}_from(&mut self, other: &Self) {
-        debug_assert_unit_is_safe_to_copy(self.gecko.${x_unit_ffi_name});
-        debug_assert_unit_is_safe_to_copy(self.gecko.${y_unit_ffi_name});
+        unsafe { self.gecko.${x_union_ffi_name}.reset(&mut self.gecko.${x_unit_ffi_name}) };
+        unsafe { self.gecko.${y_union_ffi_name}.reset(&mut self.gecko.${y_unit_ffi_name}) };
         self.gecko.${x_unit_ffi_name} = other.gecko.${x_unit_ffi_name};
         self.gecko.${x_union_ffi_name} = other.gecko.${x_union_ffi_name};
         self.gecko.${y_unit_ffi_name} = other.gecko.${y_unit_ffi_name};
         self.gecko.${y_union_ffi_name} = other.gecko.${y_union_ffi_name};
+        unsafe { self.gecko.${x_union_ffi_name}.addref_if_calc(&self.gecko.${x_unit_ffi_name}) };
+        unsafe { self.gecko.${y_union_ffi_name}.addref_if_calc(&self.gecko.${y_unit_ffi_name}) };
     }
     % if need_clone:
         fn clone_${ident}(&self) -> longhands::${ident}::computed_value::T {
@@ -627,7 +630,10 @@ fn static_assert() {
     }
 
     fn copy_z_index_from(&mut self, other: &Self) {
-        debug_assert_unit_is_safe_to_copy(self.gecko.mZIndex.mUnit);
+        use gecko_bindings::structs::nsStyleUnit;
+        // z-index is never a calc(). If it were, we'd be leaking here, so
+        // assert that it isn't.
+        debug_assert!(self.gecko.mZIndex.mUnit != nsStyleUnit::eStyleUnit_Calc);
         self.gecko.mZIndex.mUnit = other.gecko.mZIndex.mUnit;
         self.gecko.mZIndex.mValue = other.gecko.mZIndex.mValue;
     }

ports/geckolib/values.rs

@@ -43,10 +43,10 @@ pub trait StyleCoordHelpers {
 impl StyleCoordHelpers for nsStyleCoord {
     #[inline]
     fn copy_from(&mut self, other: &Self) {
-        debug_assert_unit_is_safe_to_copy(self.mUnit);
-        debug_assert_unit_is_safe_to_copy(other.mUnit);
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = other.mUnit;
         self.mValue = other.mValue;
+        unsafe { self.addref_if_calc(); }
     }
 
     #[inline]
@@ -56,6 +56,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_auto(&mut self) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Auto;
         unsafe { *self.mValue.mInt.as_mut() = 0; }
     }
@@ -66,6 +67,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_normal(&mut self) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Normal;
         unsafe { *self.mValue.mInt.as_mut() = 0; }
     }
@@ -76,6 +78,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_coord(&mut self, val: Au) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Coord;
         unsafe { *self.mValue.mInt.as_mut() = val.0; }
     }
@@ -91,6 +94,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_int(&mut self, val: i32) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Integer;
         unsafe { *self.mValue.mInt.as_mut() = val; }
     }
@@ -106,6 +110,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_enum(&mut self, val: i32) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Enumerated;
         unsafe { *self.mValue.mInt.as_mut() = val; }
     }
@@ -121,6 +126,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_percent(&mut self, val: f32) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Percent;
         unsafe { *self.mValue.mFloat.as_mut() = val; }
     }
@@ -136,6 +142,7 @@ impl StyleCoordHelpers for nsStyleCoord {
 
     #[inline]
     fn set_factor(&mut self, val: f32) {
+        unsafe { self.mValue.reset(&mut self.mUnit) };
         self.mUnit = nsStyleUnit::eStyleUnit_Factor;
         unsafe { *self.mValue.mFloat.as_mut() = val; }
     }
@@ -157,6 +164,7 @@ pub trait GeckoStyleCoordConvertible : Sized {
 
 impl GeckoStyleCoordConvertible for LengthOrPercentage {
     fn to_gecko_style_coord(&self, unit: &mut nsStyleUnit, union: &mut nsStyleUnion) {
+        unsafe { union.reset(unit) };
         match *self {
             LengthOrPercentage::Length(au) => {
                 *unit = nsStyleUnit::eStyleUnit_Coord;
@@ -166,7 +174,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentage {
                 *unit = nsStyleUnit::eStyleUnit_Percent;
                 unsafe { *union.mFloat.as_mut() = p; }
             },
-            LengthOrPercentage::Calc(_) => unimplemented!(),
+            LengthOrPercentage::Calc(calc) => unsafe { union.set_calc_value(unit, calc.into()) },
         };
     }
 
@@ -177,7 +185,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentage {
             nsStyleUnit::eStyleUnit_Percent
                 => Some(LengthOrPercentage::Percentage(unsafe { *union.mFloat.as_ref() })),
             nsStyleUnit::eStyleUnit_Calc
-                => unimplemented!(),
+                => Some(LengthOrPercentage::Calc(unsafe { union.get_calc().into() })),
             _ => None,
         }
     }
@@ -185,6 +193,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentage {
 
 impl GeckoStyleCoordConvertible for LengthOrPercentageOrAuto {
     fn to_gecko_style_coord(&self, unit: &mut nsStyleUnit, union: &mut nsStyleUnion) {
+        unsafe { union.reset(unit) };
         match *self {
             LengthOrPercentageOrAuto::Length(au) => {
                 *unit = nsStyleUnit::eStyleUnit_Coord;
@@ -198,7 +207,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentageOrAuto {
                 *unit = nsStyleUnit::eStyleUnit_Auto;
                 unsafe { *union.mInt.as_mut() = 0; }
             },
-            LengthOrPercentageOrAuto::Calc(_) => unimplemented!(),
+            LengthOrPercentageOrAuto::Calc(calc) => unsafe { union.set_calc_value(unit, calc.into()) },
         };
     }
 
@@ -211,7 +220,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentageOrAuto {
             nsStyleUnit::eStyleUnit_Percent
                 => Some(LengthOrPercentageOrAuto::Percentage(unsafe { *union.mFloat.as_ref() })),
             nsStyleUnit::eStyleUnit_Calc
-                => unimplemented!(),
+                => Some(LengthOrPercentageOrAuto::Calc(unsafe { union.get_calc().into() })),
             _ => None,
         }
     }
@@ -219,6 +228,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentageOrAuto {
 
 impl GeckoStyleCoordConvertible for LengthOrPercentageOrNone {
     fn to_gecko_style_coord(&self, unit: &mut nsStyleUnit, union: &mut nsStyleUnion) {
+        unsafe { union.reset(unit) };
         match *self {
             LengthOrPercentageOrNone::Length(au) => {
                 *unit = nsStyleUnit::eStyleUnit_Coord;
@@ -232,7 +242,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentageOrNone {
                 *unit = nsStyleUnit::eStyleUnit_None;
                 unsafe { *union.mInt.as_mut() = 0; }
             },
-            LengthOrPercentageOrNone::Calc(_) => unimplemented!(),
+            LengthOrPercentageOrNone::Calc(calc) => unsafe { union.set_calc_value(unit, calc.into()) },
         };
     }
 
@@ -245,7 +255,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentageOrNone {
             nsStyleUnit::eStyleUnit_Percent
                 => Some(LengthOrPercentageOrNone::Percentage(unsafe { *union.mFloat.as_ref() })),
             nsStyleUnit::eStyleUnit_Calc
-                => unimplemented!(),
+                => Some(LengthOrPercentageOrNone::Calc(unsafe { union.get_calc().into() })),
             _ => None,
         }
     }
@@ -253,6 +263,7 @@ impl GeckoStyleCoordConvertible for LengthOrPercentageOrNone {
 
 impl<T: GeckoStyleCoordConvertible> GeckoStyleCoordConvertible for Option<T> {
     fn to_gecko_style_coord(&self, unit: &mut nsStyleUnit, union: &mut nsStyleUnion) {
+        unsafe { union.reset(unit) };
         if let Some(ref me) = *self {
             me.to_gecko_style_coord(unit, union);
         } else {
@@ -270,6 +281,7 @@ impl GeckoStyleCoordConvertible for Angle {
     fn to_gecko_style_coord(&self,
                             unit: &mut nsStyleUnit,
                             union: &mut nsStyleUnion) {
+        unsafe { union.reset(unit) };
         *unit = nsStyleUnit::eStyleUnit_Radian;
         unsafe { *union.mFloat.as_mut() = self.radians() };
     }
@@ -310,7 +322,3 @@ pub fn round_border_to_device_pixels(width: Au, au_per_device_px: Au) -> Au {
         max(au_per_device_px, Au(width.0 / au_per_device_px.0 * au_per_device_px.0))
     }
 }
-
-pub fn debug_assert_unit_is_safe_to_copy(unit: nsStyleUnit) {
-    debug_assert!(unit != nsStyleUnit::eStyleUnit_Calc, "stylo: Can't yet handle refcounted Calc");
-}