stylo: Allow setting nsTArray members directly

ports/geckolib/gecko_bindings/lib.rs

@@ -2,6 +2,7 @@
  * 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/. */
 
+#![feature(const_fn)]
 #![feature(concat_idents)]
 #![feature(type_macros)]
 
@@ -10,5 +11,6 @@ extern crate heapsize;
 #[allow(dead_code, non_camel_case_types)]
 pub mod bindings;
 pub mod ptr;
+pub mod sugar;
 #[allow(dead_code, non_camel_case_types, non_snake_case, non_upper_case_globals)]
 pub mod structs;

ports/geckolib/gecko_bindings/sugar/mod.rs

@@ -0,0 +1,5 @@
+/* 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/. */
+
+mod ns_t_array;

ports/geckolib/gecko_bindings/sugar/ns_t_array.rs

@@ -0,0 +1,50 @@
+/* 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 std::mem;
+use std::ops::{Index, IndexMut};
+use structs::{nsTArray, nsTArrayHeader};
+
+impl<T> Index<u32> for nsTArray<T> {
+    type Output = T;
+
+    fn index<'a>(&'a self, index: u32) -> &'a T {
+        unsafe { mem::transmute(self.ptr_at(index)) }
+    }
+}
+
+impl<T> IndexMut<u32> for nsTArray<T> {
+    fn index_mut<'a>(&'a mut self, index: u32) -> &'a mut T {
+        unsafe { mem::transmute(self.ptr_at_mut(index)) }
+    }
+}
+
+impl<T> nsTArray<T> {
+    #[inline]
+    fn header<'a>(&'a self) -> &'a nsTArrayHeader {
+        debug_assert!(!self.mBuffer.is_null());
+        unsafe { mem::transmute(self.mBuffer) }
+    }
+
+    #[inline]
+    pub fn len(&self) -> u32 {
+        self.header().mLength
+    }
+
+    fn ptr_at_mut(&mut self, index: u32) -> *mut T {
+        debug_assert!(index <= self.len());
+        unsafe {
+            let slice_begin = (self.mBuffer as *const nsTArrayHeader).offset(1) as *mut T;
+            slice_begin.offset(index as isize)
+        }
+    }
+
+    fn ptr_at(&self, index: u32) -> *const T {
+        debug_assert!(index <= self.len());
+        unsafe {
+            let slice_begin = (self.mBuffer as *const nsTArrayHeader).offset(1) as *const T;
+            slice_begin.offset(index as isize)
+        }
+    }
+}

ports/geckolib/gecko_bindings/tools/regen_style_structs.sh

@@ -46,7 +46,6 @@ export RUST_BACKTRACE=1
   "-I$1/../nsprpub/pr/include"                                      \
   $PLATFORM_DEPENDENT_DEFINES                                       \
   -ignore-functions                                                 \
-  -no-bitfield-methods                                              \
   -no-type-renaming                                                 \
   -DMOZILLA_INTERNAL_API                                            \
   -DMOZ_STYLO_BINDINGS=1                                            \
@@ -99,6 +98,7 @@ export RUST_BACKTRACE=1
   -match "nsCSSScanner.h"                                           \
   -match "Types.h"                                                  \
   -match "utility"                                                  \
+  -match "nsTArray"                                                 \
   -match "pair"                                                     \
   -match "SheetParsingMode.h"                                       \
   -match "StaticPtr.h"                                              \
@@ -106,6 +106,9 @@ export RUST_BACKTRACE=1
   -blacklist-type "IsDestructibleFallbackImpl"                      \
   -blacklist-type "IsDestructibleFallback"                          \
   -blacklist-type "nsProxyReleaseEvent"                             \
+  -blacklist-type "FallibleTArray"                                  \
+  -blacklist-type "nsTArray_Impl"                                   \
+  -blacklist-type "__is_tuple_like_impl"                            \
   -opaque-type "nsIntMargin"                                        \
   -opaque-type "nsIntPoint"                                         \
   -opaque-type "nsIntRect"                                          \
@@ -130,7 +133,11 @@ if [ $? -ne 0 ]; then
 else
   echo -e "\e[34minfo:\e[0m bindgen exited successfully, running tests"
   TESTS_FILE=$(mktemp)
-  rustc ../structs.rs --test -o $TESTS_FILE
+  TESTS_SRC=$(mktemp)
+  echo "#![feature(const_fn)]" > $TESTS_SRC
+  cat ../structs.rs >> $TESTS_SRC
+  rustc $TESTS_SRC --test -o $TESTS_FILE
   $TESTS_FILE
   rm $TESTS_FILE
+  rm $TESTS_SRC
 fi

ports/geckolib/properties.mako.rs

@@ -809,11 +809,10 @@ fn static_assert() {
                         };
 
                         unsafe {
-                            Gecko_SetGradientStop(gecko_gradient,
-                                                  index as u32,
-                                                  &coord,
-                                                  color,
-                                                  /* interpolation_hint = */ false);
+                            let mut stop = &mut (*gecko_gradient).mStops[index as u32];
+                            stop.mColor = color;
+                            stop.mIsInterpolationHint = false;
+                            stop.mLocation.copy_from(&coord);
                         }
                     }