Handle RawGeckoElement and friends, add support for types which are used in both maybe-null and non-null forms

components/style/properties/gecko.mako.rs

@@ -24,7 +24,7 @@ use gecko_bindings::bindings::{Gecko_EnsureImageLayersLength, Gecko_CreateGradie
 use gecko_bindings::bindings::{Gecko_CopyImageValueFrom, Gecko_CopyFontFamilyFrom};
 use gecko_bindings::bindings::{Gecko_FontFamilyList_AppendGeneric, Gecko_FontFamilyList_AppendNamed};
 use gecko_bindings::bindings::{Gecko_FontFamilyList_Clear, Gecko_InitializeImageLayer};
-use gecko_bindings::bindings::ServoComputedValuesBorrowed;
+use gecko_bindings::bindings::ServoComputedValuesMaybeBorrowed;
 use gecko_bindings::structs;
 use gecko_bindings::sugar::ns_style_coord::{CoordDataValue, CoordData, CoordDataMut};
 use gecko_values::{StyleCoordHelpers, GeckoStyleCoordConvertible, convert_nscolor_to_rgba};
@@ -1712,8 +1712,8 @@ fn static_assert() {
 <%def name="define_ffi_struct_accessor(style_struct)">
 #[no_mangle]
 #[allow(non_snake_case, unused_variables)]
-pub extern "C" fn Servo_GetStyle${style_struct.gecko_name}(computed_values: ServoComputedValuesBorrowed)
-  -> *const ${style_struct.gecko_ffi_name} {
+pub extern "C" fn Servo_GetStyle${style_struct.gecko_name}(computed_values:
+        ServoComputedValuesMaybeBorrowed) -> *const ${style_struct.gecko_ffi_name} {
     computed_values.as_arc::<ComputedValues>().get_${style_struct.name_lower}().get_gecko()
         as *const ${style_struct.gecko_ffi_name}
 }

ports/geckolib/binding_tools/regen.py

@@ -156,11 +156,15 @@ COMPILATION_TARGETS = {
         ],
         "servo_owned_types": [
             "RawServoStyleSet",
-            "RawGeckoNode",
         ],
         "servo_maybe_owned_types": [
             "ServoNodeData",
         ],
+        "servo_immutable_borrow_types": [
+            "RawGeckoNode",
+            "RawGeckoElement",
+            "RawGeckoDocument",
+        ],
     },
 
     "atoms": {
@@ -329,9 +333,19 @@ def build(objdir, target_name, debug, debugger, kind_name=None,
             flags.append("--raw-line")
             flags.append("pub type {0}Strong = ::sugar::ownership::Strong<{0}>;".format(ty))
             flags.append("--blacklist-type")
+            flags.append("{}MaybeBorrowed".format(ty))
+            flags.append("-raw-line")
+            flags.append("pub type {0}MaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, {0}>;".format(ty))
+    if "servo_immutable_borrow_types" in current_target:
+        for ty in current_target["servo_immutable_borrow_types"]:
+            flags.append("-blacklist-type")
             flags.append("{}Borrowed".format(ty))
             flags.append("--raw-line")
-            flags.append("pub type {0}Borrowed<'a> = ::sugar::ownership::Borrowed<'a, {0}>;".format(ty))
+            flags.append("pub type {0}Borrowed<'a> = &'a {0};".format(ty))
+            flags.append("--blacklist-type")
+            flags.append("{}MaybeBorrowed".format(ty))
+            flags.append("--raw-line")
+            flags.append("pub type {0}MaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, {0}>;".format(ty))
     if "servo_owned_types" in current_target:
         for ty in current_target["servo_owned_types"]:
             flags.append("--blacklist-type")
@@ -349,19 +363,19 @@ def build(objdir, target_name, debug, debugger, kind_name=None,
     if "servo_maybe_owned_types" in current_target:
         for ty in current_target["servo_maybe_owned_types"]:
             flags.append("--blacklist-type")
-            flags.append("{}Borrowed".format(ty))
+            flags.append("{}MaybeBorrowed".format(ty))
             flags.append("--raw-line")
-            flags.append("pub type {0}Borrowed<'a> = ::sugar::ownership::Borrowed<'a, {0}>;"
+            flags.append("pub type {0}MaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, {0}>;"
                          .format(ty))
             flags.append("--blacklist-type")
-            flags.append("{}BorrowedMut".format(ty))
+            flags.append("{}MaybeBorrowedMut".format(ty))
             flags.append("--raw-line")
-            flags.append("pub type {0}BorrowedMut<'a> = ::sugar::ownership::BorrowedMut<'a, {0}>;"
+            flags.append("pub type {0}MaybeBorrowedMut<'a> = ::sugar::ownership::BorrowedMut<'a, {0}>;"
                          .format(ty))
             flags.append("--blacklist-type")
-            flags.append("{}Owned".format(ty))
+            flags.append("{}MaybeOwned".format(ty))
             flags.append("--raw-line")
-            flags.append("pub type {0}Owned = ::sugar::ownership::MaybeOwned<{0}>;".format(ty))
+            flags.append("pub type {0}MaybeOwned = ::sugar::ownership::MaybeOwned<{0}>;".format(ty))
     if "structs_types" in current_target:
         for ty in current_target["structs_types"]:
             ty_fragments = ty.split("::")

ports/geckolib/gecko_bindings/bindings.rs

@@ -6,20 +6,23 @@ pub enum nsIDocument {}
 pub enum nsIPrincipal {}
 pub enum nsIURI {}
 pub type ServoComputedValuesStrong = ::sugar::ownership::Strong<ServoComputedValues>;
-pub type ServoComputedValuesBorrowed<'a> = ::sugar::ownership::Borrowed<'a, ServoComputedValues>;
+pub type ServoComputedValuesMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, ServoComputedValues>;
 pub type RawServoStyleSheetStrong = ::sugar::ownership::Strong<RawServoStyleSheet>;
-pub type RawServoStyleSheetBorrowed<'a> = ::sugar::ownership::Borrowed<'a, RawServoStyleSheet>;
+pub type RawServoStyleSheetMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, RawServoStyleSheet>;
 pub type ServoDeclarationBlockStrong = ::sugar::ownership::Strong<ServoDeclarationBlock>;
-pub type ServoDeclarationBlockBorrowed<'a> = ::sugar::ownership::Borrowed<'a, ServoDeclarationBlock>;
+pub type ServoDeclarationBlockMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, ServoDeclarationBlock>;
+pub type RawGeckoNodeBorrowed<'a> = &'a RawGeckoNode;
+pub type RawGeckoNodeMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, RawGeckoNode>;
+pub type RawGeckoElementBorrowed<'a> = &'a RawGeckoElement;
+pub type RawGeckoElementMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, RawGeckoElement>;
+pub type RawGeckoDocumentBorrowed<'a> = &'a RawGeckoDocument;
+pub type RawGeckoDocumentMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, RawGeckoDocument>;
 pub type RawServoStyleSetBorrowed<'a> = &'a RawServoStyleSet;
 pub type RawServoStyleSetBorrowedMut<'a> = &'a mut RawServoStyleSet;
 pub type RawServoStyleSetOwned = ::sugar::ownership::Owned<RawServoStyleSet>;
-pub type RawGeckoNodeBorrowed<'a> = &'a RawGeckoNode;
-pub type RawGeckoNodeBorrowedMut<'a> = &'a mut RawGeckoNode;
-pub type RawGeckoNodeOwned = ::sugar::ownership::Owned<RawGeckoNode>;
-pub type ServoNodeDataBorrowed<'a> = ::sugar::ownership::Borrowed<'a, ServoNodeData>;
-pub type ServoNodeDataBorrowedMut<'a> = ::sugar::ownership::BorrowedMut<'a, ServoNodeData>;
-pub type ServoNodeDataOwned = ::sugar::ownership::MaybeOwned<ServoNodeData>;
+pub type ServoNodeDataMaybeBorrowed<'a> = ::sugar::ownership::Borrowed<'a, ServoNodeData>;
+pub type ServoNodeDataMaybeBorrowedMut<'a> = ::sugar::ownership::BorrowedMut<'a, ServoNodeData>;
+pub type ServoNodeDataMaybeOwned = ::sugar::ownership::MaybeOwned<ServoNodeData>;
 use structs::nsStyleFont;
 unsafe impl Send for nsStyleFont {}
 unsafe impl Sync for nsStyleFont {}
@@ -182,26 +185,31 @@ pub enum StyleChildrenIterator { }
 pub type ThreadSafePrincipalHolder = nsMainThreadPtrHolder<nsIPrincipal>;
 pub type ThreadSafeURIHolder = nsMainThreadPtrHolder<nsIURI>;
 extern "C" {
-    pub fn Gecko_ChildrenCount(node: *mut RawGeckoNode) -> u32;
-    pub fn Gecko_NodeIsElement(node: *mut RawGeckoNode) -> bool;
-    pub fn Gecko_GetParentNode(node: *mut RawGeckoNode) -> *mut RawGeckoNode;
-    pub fn Gecko_GetFirstChild(node: *mut RawGeckoNode) -> *mut RawGeckoNode;
-    pub fn Gecko_GetLastChild(node: *mut RawGeckoNode) -> *mut RawGeckoNode;
-    pub fn Gecko_GetPrevSibling(node: *mut RawGeckoNode) -> *mut RawGeckoNode;
-    pub fn Gecko_GetNextSibling(node: *mut RawGeckoNode) -> *mut RawGeckoNode;
-    pub fn Gecko_GetParentElement(element: *mut RawGeckoElement)
-     -> *mut RawGeckoElement;
-    pub fn Gecko_GetFirstChildElement(element: *mut RawGeckoElement)
-     -> *mut RawGeckoElement;
-    pub fn Gecko_GetLastChildElement(element: *mut RawGeckoElement)
-     -> *mut RawGeckoElement;
-    pub fn Gecko_GetPrevSiblingElement(element: *mut RawGeckoElement)
-     -> *mut RawGeckoElement;
-    pub fn Gecko_GetNextSiblingElement(element: *mut RawGeckoElement)
-     -> *mut RawGeckoElement;
-    pub fn Gecko_GetDocumentElement(document: *mut RawGeckoDocument)
-     -> *mut RawGeckoElement;
-    pub fn Gecko_MaybeCreateStyleChildrenIterator(node: *mut RawGeckoNode)
+    pub fn Gecko_ChildrenCount(node: RawGeckoNodeBorrowed) -> u32;
+    pub fn Gecko_NodeIsElement(node: RawGeckoNodeBorrowed) -> bool;
+    pub fn Gecko_GetParentNode(node: RawGeckoNodeBorrowed)
+     -> RawGeckoNodeMaybeBorrowed;
+    pub fn Gecko_GetFirstChild(node: RawGeckoNodeBorrowed)
+     -> RawGeckoNodeMaybeBorrowed;
+    pub fn Gecko_GetLastChild(node: RawGeckoNodeBorrowed)
+     -> RawGeckoNodeMaybeBorrowed;
+    pub fn Gecko_GetPrevSibling(node: RawGeckoNodeBorrowed)
+     -> RawGeckoNodeMaybeBorrowed;
+    pub fn Gecko_GetNextSibling(node: RawGeckoNodeBorrowed)
+     -> RawGeckoNodeMaybeBorrowed;
+    pub fn Gecko_GetParentElement(element: RawGeckoElementBorrowed)
+     -> RawGeckoElementMaybeBorrowed;
+    pub fn Gecko_GetFirstChildElement(element: RawGeckoElementBorrowed)
+     -> RawGeckoElementMaybeBorrowed;
+    pub fn Gecko_GetLastChildElement(element: RawGeckoElementBorrowed)
+     -> RawGeckoElementMaybeBorrowed;
+    pub fn Gecko_GetPrevSiblingElement(element: RawGeckoElementBorrowed)
+     -> RawGeckoElementMaybeBorrowed;
+    pub fn Gecko_GetNextSiblingElement(element: RawGeckoElementBorrowed)
+     -> RawGeckoElementMaybeBorrowed;
+    pub fn Gecko_GetDocumentElement(document: RawGeckoDocumentBorrowed)
+     -> RawGeckoElementMaybeBorrowed;
+    pub fn Gecko_MaybeCreateStyleChildrenIterator(node: RawGeckoNodeBorrowed)
      -> *mut StyleChildrenIterator;
     pub fn Gecko_DropStyleChildrenIterator(it: *mut StyleChildrenIterator);
     pub fn Gecko_GetNextStyleChild(it: *mut StyleChildrenIterator)
@@ -209,36 +217,38 @@ extern "C" {
     pub fn Gecko_ElementState(element: *mut RawGeckoElement) -> u8;
     pub fn Gecko_IsHTMLElementInHTMLDocument(element: *mut RawGeckoElement)
      -> bool;
-    pub fn Gecko_IsLink(element: *mut RawGeckoElement) -> bool;
-    pub fn Gecko_IsTextNode(node: *mut RawGeckoNode) -> bool;
-    pub fn Gecko_IsVisitedLink(element: *mut RawGeckoElement) -> bool;
-    pub fn Gecko_IsUnvisitedLink(element: *mut RawGeckoElement) -> bool;
-    pub fn Gecko_IsRootElement(element: *mut RawGeckoElement) -> bool;
-    pub fn Gecko_LocalName(element: *mut RawGeckoElement) -> *mut nsIAtom;
-    pub fn Gecko_Namespace(element: *mut RawGeckoElement) -> *mut nsIAtom;
-    pub fn Gecko_GetElementId(element: *mut RawGeckoElement) -> *mut nsIAtom;
-    pub fn Gecko_AtomAttrValue(element: *mut RawGeckoElement,
+    pub fn Gecko_IsLink(element: RawGeckoElementBorrowed) -> bool;
+    pub fn Gecko_IsTextNode(node: RawGeckoNodeBorrowed) -> bool;
+    pub fn Gecko_IsVisitedLink(element: RawGeckoElementBorrowed) -> bool;
+    pub fn Gecko_IsUnvisitedLink(element: RawGeckoElementBorrowed) -> bool;
+    pub fn Gecko_IsRootElement(element: RawGeckoElementBorrowed) -> bool;
+    pub fn Gecko_LocalName(element: RawGeckoElementBorrowed) -> *mut nsIAtom;
+    pub fn Gecko_Namespace(element: RawGeckoElementBorrowed) -> *mut nsIAtom;
+    pub fn Gecko_GetElementId(element: RawGeckoElementBorrowed)
+     -> *mut nsIAtom;
+    pub fn Gecko_AtomAttrValue(element: RawGeckoElementBorrowed,
                                attribute: *mut nsIAtom) -> *mut nsIAtom;
-    pub fn Gecko_HasAttr(element: *mut RawGeckoElement, ns: *mut nsIAtom,
+    pub fn Gecko_HasAttr(element: RawGeckoElementBorrowed, ns: *mut nsIAtom,
                          name: *mut nsIAtom) -> bool;
-    pub fn Gecko_AttrEquals(element: *mut RawGeckoElement, ns: *mut nsIAtom,
-                            name: *mut nsIAtom, str: *mut nsIAtom,
-                            ignoreCase: bool) -> bool;
-    pub fn Gecko_AttrDashEquals(element: *mut RawGeckoElement,
+    pub fn Gecko_AttrEquals(element: RawGeckoElementBorrowed,
+                            ns: *mut nsIAtom, name: *mut nsIAtom,
+                            str: *mut nsIAtom, ignoreCase: bool) -> bool;
+    pub fn Gecko_AttrDashEquals(element: RawGeckoElementBorrowed,
                                 ns: *mut nsIAtom, name: *mut nsIAtom,
                                 str: *mut nsIAtom) -> bool;
-    pub fn Gecko_AttrIncludes(element: *mut RawGeckoElement, ns: *mut nsIAtom,
-                              name: *mut nsIAtom, str: *mut nsIAtom) -> bool;
-    pub fn Gecko_AttrHasSubstring(element: *mut RawGeckoElement,
+    pub fn Gecko_AttrIncludes(element: RawGeckoElementBorrowed,
+                              ns: *mut nsIAtom, name: *mut nsIAtom,
+                              str: *mut nsIAtom) -> bool;
+    pub fn Gecko_AttrHasSubstring(element: RawGeckoElementBorrowed,
                                   ns: *mut nsIAtom, name: *mut nsIAtom,
                                   str: *mut nsIAtom) -> bool;
-    pub fn Gecko_AttrHasPrefix(element: *mut RawGeckoElement,
+    pub fn Gecko_AttrHasPrefix(element: RawGeckoElementBorrowed,
                                ns: *mut nsIAtom, name: *mut nsIAtom,
                                str: *mut nsIAtom) -> bool;
-    pub fn Gecko_AttrHasSuffix(element: *mut RawGeckoElement,
+    pub fn Gecko_AttrHasSuffix(element: RawGeckoElementBorrowed,
                                ns: *mut nsIAtom, name: *mut nsIAtom,
                                str: *mut nsIAtom) -> bool;
-    pub fn Gecko_ClassOrClassList(element: *mut RawGeckoElement,
+    pub fn Gecko_ClassOrClassList(element: RawGeckoElementBorrowed,
                                   class_: *mut *mut nsIAtom,
                                   classList: *mut *mut *mut nsIAtom) -> u32;
     pub fn Gecko_SnapshotAtomAttrValue(element: *mut ServoElementSnapshot,
@@ -271,12 +281,12 @@ extern "C" {
                                           class_: *mut *mut nsIAtom,
                                           classList: *mut *mut *mut nsIAtom)
      -> u32;
-    pub fn Gecko_GetServoDeclarationBlock(element: *mut RawGeckoElement)
-     -> ServoDeclarationBlockBorrowed;
+    pub fn Gecko_GetServoDeclarationBlock(element: RawGeckoElementBorrowed)
+     -> ServoDeclarationBlockMaybeBorrowed;
     pub fn Gecko_GetNodeData(node: RawGeckoNodeBorrowed)
-     -> ServoNodeDataBorrowed;
-    pub fn Gecko_SetNodeData(node: RawGeckoNodeBorrowedMut,
-                             data: ServoNodeDataOwned);
+     -> ServoNodeDataMaybeBorrowed;
+    pub fn Gecko_SetNodeData(node: RawGeckoNodeBorrowed,
+                             data: ServoNodeDataMaybeOwned);
     pub fn Gecko_Atomize(aString: *const ::std::os::raw::c_char, aLength: u32)
      -> *mut nsIAtom;
     pub fn Gecko_AddRefAtom(aAtom: *mut nsIAtom);
@@ -320,16 +330,17 @@ extern "C" {
                                principal: *mut ThreadSafePrincipalHolder);
     pub fn Gecko_CopyMozBindingFrom(des: *mut nsStyleDisplay,
                                     src: *const nsStyleDisplay);
-    pub fn Gecko_GetNodeFlags(node: *mut RawGeckoNode) -> u32;
-    pub fn Gecko_SetNodeFlags(node: *mut RawGeckoNode, flags: u32);
-    pub fn Gecko_UnsetNodeFlags(node: *mut RawGeckoNode, flags: u32);
-    pub fn Gecko_GetStyleContext(node: *mut RawGeckoNode,
+    pub fn Gecko_GetNodeFlags(node: RawGeckoNodeBorrowed) -> u32;
+    pub fn Gecko_SetNodeFlags(node: RawGeckoNodeBorrowed, flags: u32);
+    pub fn Gecko_UnsetNodeFlags(node: RawGeckoNodeBorrowed, flags: u32);
+    pub fn Gecko_GetStyleContext(node: RawGeckoNodeBorrowed,
                                  aPseudoTagOrNull: *mut nsIAtom)
      -> *mut nsStyleContext;
     pub fn Gecko_CalcStyleDifference(oldstyle: *mut nsStyleContext,
-                                     newstyle: ServoComputedValuesBorrowed)
+                                     newstyle:
+                                         ServoComputedValuesMaybeBorrowed)
      -> nsChangeHint;
-    pub fn Gecko_StoreStyleDifference(node: *mut RawGeckoNode,
+    pub fn Gecko_StoreStyleDifference(node: RawGeckoNodeBorrowed,
                                       change: nsChangeHint);
     pub fn Gecko_EnsureTArrayCapacity(array: *mut ::std::os::raw::c_void,
                                       capacity: usize, elem_size: usize);
@@ -466,7 +477,7 @@ extern "C" {
     pub fn Gecko_CopyConstruct_nsStyleEffects(ptr: *mut nsStyleEffects,
                                               other: *const nsStyleEffects);
     pub fn Gecko_Destroy_nsStyleEffects(ptr: *mut nsStyleEffects);
-    pub fn Servo_NodeData_Drop(data: ServoNodeDataOwned);
+    pub fn Servo_NodeData_Drop(data: ServoNodeDataMaybeOwned);
     pub fn Servo_StyleSheet_FromUTF8Bytes(bytes: *const u8, length: u32,
                                           parsing_mode: SheetParsingMode,
                                           base_bytes: *const u8,
@@ -476,49 +487,49 @@ extern "C" {
                                           principal:
                                               *mut ThreadSafePrincipalHolder)
      -> RawServoStyleSheetStrong;
-    pub fn Servo_StyleSheet_AddRef(sheet: RawServoStyleSheetBorrowed);
-    pub fn Servo_StyleSheet_Release(sheet: RawServoStyleSheetBorrowed);
-    pub fn Servo_StyleSheet_HasRules(sheet: RawServoStyleSheetBorrowed)
+    pub fn Servo_StyleSheet_AddRef(sheet: RawServoStyleSheetMaybeBorrowed);
+    pub fn Servo_StyleSheet_Release(sheet: RawServoStyleSheetMaybeBorrowed);
+    pub fn Servo_StyleSheet_HasRules(sheet: RawServoStyleSheetMaybeBorrowed)
      -> bool;
     pub fn Servo_StyleSet_Init() -> RawServoStyleSetOwned;
     pub fn Servo_StyleSet_Drop(set: RawServoStyleSetOwned);
     pub fn Servo_StyleSet_AppendStyleSheet(set: RawServoStyleSetBorrowedMut,
-                                           sheet: RawServoStyleSheetBorrowed);
+                                           sheet: RawServoStyleSheetMaybeBorrowed);
     pub fn Servo_StyleSet_PrependStyleSheet(set: RawServoStyleSetBorrowedMut,
                                             sheet:
-                                                RawServoStyleSheetBorrowed);
+                                                RawServoStyleSheetMaybeBorrowed);
     pub fn Servo_StyleSet_RemoveStyleSheet(set: RawServoStyleSetBorrowedMut,
-                                           sheet: RawServoStyleSheetBorrowed);
+                                           sheet: RawServoStyleSheetMaybeBorrowed);
     pub fn Servo_StyleSet_InsertStyleSheetBefore(set: RawServoStyleSetBorrowedMut,
                                                  sheet:
-                                                     RawServoStyleSheetBorrowed,
+                                                     RawServoStyleSheetMaybeBorrowed,
                                                  reference:
-                                                     RawServoStyleSheetBorrowed);
+                                                     RawServoStyleSheetMaybeBorrowed);
     pub fn Servo_ParseStyleAttribute(bytes: *const u8, length: u32,
                                      cache: *mut nsHTMLCSSStyleSheet)
      -> ServoDeclarationBlockStrong;
     pub fn Servo_DeclarationBlock_AddRef(declarations:
-                                             ServoDeclarationBlockBorrowed);
+                                             ServoDeclarationBlockMaybeBorrowed);
     pub fn Servo_DeclarationBlock_Release(declarations:
-                                              ServoDeclarationBlockBorrowed);
+                                              ServoDeclarationBlockMaybeBorrowed);
     pub fn Servo_DeclarationBlock_GetCache(declarations:
-                                               ServoDeclarationBlockBorrowed)
+                                               ServoDeclarationBlockMaybeBorrowed)
      -> *mut nsHTMLCSSStyleSheet;
     pub fn Servo_DeclarationBlock_SetImmutable(declarations:
-                                                   ServoDeclarationBlockBorrowed);
+                                                   ServoDeclarationBlockMaybeBorrowed);
     pub fn Servo_DeclarationBlock_ClearCachePointer(declarations:
-                                                        ServoDeclarationBlockBorrowed);
+                                                        ServoDeclarationBlockMaybeBorrowed);
     pub fn Servo_CSSSupports(name: *const u8, name_length: u32,
                              value: *const u8, value_length: u32) -> bool;
-    pub fn Servo_ComputedValues_Get(node: *mut RawGeckoNode)
+    pub fn Servo_ComputedValues_Get(node: RawGeckoNodeBorrowed)
      -> ServoComputedValuesStrong;
     pub fn Servo_ComputedValues_GetForAnonymousBox(parent_style_or_null:
-                                                       ServoComputedValuesBorrowed,
+                                                       ServoComputedValuesMaybeBorrowed,
                                                    pseudoTag: *mut nsIAtom,
                                                    set: RawServoStyleSetBorrowedMut)
      -> ServoComputedValuesStrong;
     pub fn Servo_ComputedValues_GetForPseudoElement(parent_style:
-                                                        ServoComputedValuesBorrowed,
+                                                        ServoComputedValuesMaybeBorrowed,
                                                     match_element:
                                                         *mut RawGeckoElement,
                                                     pseudo_tag: *mut nsIAtom,
@@ -527,76 +538,92 @@ extern "C" {
                                                     is_probe: bool)
      -> ServoComputedValuesStrong;
     pub fn Servo_ComputedValues_Inherit(parent_style:
-                                            ServoComputedValuesBorrowed)
+                                            ServoComputedValuesMaybeBorrowed)
      -> ServoComputedValuesStrong;
     pub fn Servo_ComputedValues_AddRef(computed_values:
-                                           ServoComputedValuesBorrowed);
+                                           ServoComputedValuesMaybeBorrowed);
     pub fn Servo_ComputedValues_Release(computed_values:
-                                            ServoComputedValuesBorrowed);
+                                            ServoComputedValuesMaybeBorrowed);
     pub fn Servo_Initialize();
     pub fn Servo_Shutdown();
     pub fn Servo_ComputeRestyleHint(element: *mut RawGeckoElement,
                                     snapshot: *mut ServoElementSnapshot,
                                     set: RawServoStyleSetBorrowedMut)
      -> nsRestyleHint;
-    pub fn Servo_RestyleDocument(doc: *mut RawGeckoDocument,
+    pub fn Servo_RestyleDocument(doc: RawGeckoDocumentBorrowed,
                                  set: RawServoStyleSetBorrowedMut);
-    pub fn Servo_RestyleSubtree(node: *mut RawGeckoNode,
+    pub fn Servo_RestyleSubtree(node: RawGeckoNodeBorrowed,
                                 set: RawServoStyleSetBorrowedMut);
-    pub fn Servo_GetStyleFont(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleFont(computed_values:
+                                  ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleFont;
-    pub fn Servo_GetStyleColor(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleColor(computed_values:
+                                   ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleColor;
-    pub fn Servo_GetStyleList(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleList(computed_values:
+                                  ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleList;
-    pub fn Servo_GetStyleText(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleText(computed_values:
+                                  ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleText;
     pub fn Servo_GetStyleVisibility(computed_values:
-                                        ServoComputedValuesBorrowed)
+                                        ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleVisibility;
     pub fn Servo_GetStyleUserInterface(computed_values:
-                                           ServoComputedValuesBorrowed)
+                                           ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleUserInterface;
     pub fn Servo_GetStyleTableBorder(computed_values:
-                                         ServoComputedValuesBorrowed)
+                                         ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleTableBorder;
-    pub fn Servo_GetStyleSVG(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleSVG(computed_values:
+                                 ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleSVG;
     pub fn Servo_GetStyleVariables(computed_values:
-                                       ServoComputedValuesBorrowed)
+                                       ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleVariables;
     pub fn Servo_GetStyleBackground(computed_values:
-                                        ServoComputedValuesBorrowed)
+                                        ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleBackground;
     pub fn Servo_GetStylePosition(computed_values:
-                                      ServoComputedValuesBorrowed)
+                                      ServoComputedValuesMaybeBorrowed)
      -> *const nsStylePosition;
     pub fn Servo_GetStyleTextReset(computed_values:
-                                       ServoComputedValuesBorrowed)
+                                       ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleTextReset;
-    pub fn Servo_GetStyleDisplay(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleDisplay(computed_values:
+                                     ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleDisplay;
-    pub fn Servo_GetStyleContent(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleContent(computed_values:
+                                     ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleContent;
-    pub fn Servo_GetStyleUIReset(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleUIReset(computed_values:
+                                     ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleUIReset;
-    pub fn Servo_GetStyleTable(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleTable(computed_values:
+                                   ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleTable;
-    pub fn Servo_GetStyleMargin(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleMargin(computed_values:
+                                    ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleMargin;
-    pub fn Servo_GetStylePadding(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStylePadding(computed_values:
+                                     ServoComputedValuesMaybeBorrowed)
      -> *const nsStylePadding;
-    pub fn Servo_GetStyleBorder(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleBorder(computed_values:
+                                    ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleBorder;
-    pub fn Servo_GetStyleOutline(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleOutline(computed_values:
+                                     ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleOutline;
-    pub fn Servo_GetStyleXUL(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleXUL(computed_values:
+                                 ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleXUL;
     pub fn Servo_GetStyleSVGReset(computed_values:
-                                      ServoComputedValuesBorrowed)
+                                      ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleSVGReset;
-    pub fn Servo_GetStyleColumn(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleColumn(computed_values:
+                                    ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleColumn;
-    pub fn Servo_GetStyleEffects(computed_values: ServoComputedValuesBorrowed)
+    pub fn Servo_GetStyleEffects(computed_values:
+                                     ServoComputedValuesMaybeBorrowed)
      -> *const nsStyleEffects;
 }

ports/geckolib/gecko_bindings/sugar/ownership.rs

@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use std::marker::PhantomData;
-use std::mem::{forget, transmute};
+use std::mem::{forget, transmute, transmute_copy};
 use std::ops::{Deref, DerefMut};
 use std::ptr;
 use std::sync::Arc;

ports/geckolib/glue.rs

@@ -9,12 +9,14 @@ use data::{NUM_THREADS, PerDocumentStyleData};
 use env_logger;
 use euclid::Size2D;
 use gecko_bindings::bindings::{RawGeckoDocument, RawGeckoElement, RawGeckoNode};
+use gecko_bindings::bindings::RawGeckoDocumentBorrowed;
+use gecko_bindings::bindings::{RawGeckoElementBorrowed, RawGeckoNodeBorrowed};
 use gecko_bindings::bindings::{RawServoStyleSet, RawServoStyleSetBorrowedMut};
-use gecko_bindings::bindings::{RawServoStyleSetOwned, ServoNodeDataOwned};
-use gecko_bindings::bindings::{RawServoStyleSheetBorrowed, ServoComputedValuesBorrowed};
+use gecko_bindings::bindings::{RawServoStyleSetOwned, ServoNodeDataMaybeOwned};
+use gecko_bindings::bindings::{RawServoStyleSheetMaybeBorrowed, ServoComputedValuesMaybeBorrowed};
 use gecko_bindings::bindings::{RawServoStyleSheetStrong, ServoComputedValuesStrong};
 use gecko_bindings::bindings::{ServoDeclarationBlock, ThreadSafePrincipalHolder};
-use gecko_bindings::bindings::{ServoDeclarationBlockBorrowed, ServoDeclarationBlockStrong};
+use gecko_bindings::bindings::{ServoDeclarationBlockMaybeBorrowed, ServoDeclarationBlockStrong};
 use gecko_bindings::bindings::{ThreadSafeURIHolder, nsHTMLCSSStyleSheet};
 use gecko_bindings::ptr::{GeckoArcPrincipal, GeckoArcURI};
 use gecko_bindings::structs::ServoElementSnapshot;
@@ -114,15 +116,15 @@ fn restyle_subtree(node: GeckoNode, raw_data: RawServoStyleSetBorrowedMut) {
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_RestyleSubtree(node: *mut RawGeckoNode,
+pub extern "C" fn Servo_RestyleSubtree(node: RawGeckoNodeBorrowed,
                                        raw_data: RawServoStyleSetBorrowedMut) -> () {
-    let node = unsafe { GeckoNode::from_raw(node) };
+    let node = GeckoNode(node);
     restyle_subtree(node, raw_data);
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_RestyleDocument(doc: *mut RawGeckoDocument, raw_data: RawServoStyleSetBorrowedMut) -> () {
-    let document = unsafe { GeckoDocument::from_raw(doc) };
+pub extern "C" fn Servo_RestyleDocument(doc: RawGeckoDocumentBorrowed, raw_data: RawServoStyleSetBorrowedMut) -> () {
+    let document = GeckoDocument(doc);
     let node = match document.root_node() {
         Some(x) => x,
         None => return,
@@ -136,7 +138,7 @@ pub extern "C" fn Servo_StyleWorkerThreadCount() -> u32 {
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_NodeData_Drop(data: ServoNodeDataOwned) -> () {
+pub extern "C" fn Servo_NodeData_Drop(data: ServoNodeDataMaybeOwned) -> () {
     let _ = data.into_box_opt::<NonOpaqueStyleData>();
 }
 
@@ -174,7 +176,7 @@ pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(bytes: *const u8,
 
 #[no_mangle]
 pub extern "C" fn Servo_StyleSet_AppendStyleSheet(raw_data: RawServoStyleSetBorrowedMut,
-                                                  raw_sheet: RawServoStyleSheetBorrowed) {
+                                                  raw_sheet: RawServoStyleSheetMaybeBorrowed) {
     let data = PerDocumentStyleData::from_ffi_mut(raw_data);
     let sheet = raw_sheet.as_arc();
     data.stylesheets.retain(|x| !arc_ptr_eq(x, sheet));
@@ -184,7 +186,7 @@ pub extern "C" fn Servo_StyleSet_AppendStyleSheet(raw_data: RawServoStyleSetBorr
 
 #[no_mangle]
 pub extern "C" fn Servo_StyleSet_PrependStyleSheet(raw_data: RawServoStyleSetBorrowedMut,
-                                                   raw_sheet: RawServoStyleSheetBorrowed) {
+                                                   raw_sheet: RawServoStyleSheetMaybeBorrowed) {
     let data = PerDocumentStyleData::from_ffi_mut(raw_data);
     let sheet = raw_sheet.as_arc();
     data.stylesheets.retain(|x| !arc_ptr_eq(x, sheet));
@@ -194,8 +196,8 @@ pub extern "C" fn Servo_StyleSet_PrependStyleSheet(raw_data: RawServoStyleSetBor
 
 #[no_mangle]
 pub extern "C" fn Servo_StyleSet_InsertStyleSheetBefore(raw_data: RawServoStyleSetBorrowedMut,
-                                                        raw_sheet: RawServoStyleSheetBorrowed,
-                                                        raw_reference: RawServoStyleSheetBorrowed) {
+                                                        raw_sheet: RawServoStyleSheetMaybeBorrowed,
+                                                        raw_reference: RawServoStyleSheetMaybeBorrowed) {
     let data = PerDocumentStyleData::from_ffi_mut(raw_data);
     let sheet = raw_sheet.as_arc();
     let reference = raw_reference.as_arc();
@@ -207,7 +209,7 @@ pub extern "C" fn Servo_StyleSet_InsertStyleSheetBefore(raw_data: RawServoStyleS
 
 #[no_mangle]
 pub extern "C" fn Servo_StyleSet_RemoveStyleSheet(raw_data: RawServoStyleSetBorrowedMut,
-                                                  raw_sheet: RawServoStyleSheetBorrowed) {
+                                                  raw_sheet: RawServoStyleSheetMaybeBorrowed) {
     let data = PerDocumentStyleData::from_ffi_mut(raw_data);
     let sheet = raw_sheet.as_arc();
     data.stylesheets.retain(|x| !arc_ptr_eq(x, sheet));
@@ -215,24 +217,24 @@ pub extern "C" fn Servo_StyleSet_RemoveStyleSheet(raw_data: RawServoStyleSetBorr
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_StyleSheet_HasRules(raw_sheet: RawServoStyleSheetBorrowed) -> bool {
+pub extern "C" fn Servo_StyleSheet_HasRules(raw_sheet: RawServoStyleSheetMaybeBorrowed) -> bool {
     !raw_sheet.as_arc::<Stylesheet>().rules.is_empty()
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_StyleSheet_AddRef(sheet: RawServoStyleSheetBorrowed) -> () {
+pub extern "C" fn Servo_StyleSheet_AddRef(sheet: RawServoStyleSheetMaybeBorrowed) -> () {
     unsafe { Stylesheet::addref(sheet) };
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_StyleSheet_Release(sheet: RawServoStyleSheetBorrowed) -> () {
+pub extern "C" fn Servo_StyleSheet_Release(sheet: RawServoStyleSheetMaybeBorrowed) -> () {
     unsafe { Stylesheet::release(sheet) };
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputedValues_Get(node: *mut RawGeckoNode)
+pub extern "C" fn Servo_ComputedValues_Get(node: RawGeckoNodeBorrowed)
      -> ServoComputedValuesStrong {
-    let node = unsafe { GeckoNode::from_raw(node) };
+    let node = unsafe { GeckoNode(node) };
     let arc_cv = match node.borrow_data().map_or(None, |data| data.style.clone()) {
         Some(style) => style,
         None => {
@@ -248,7 +250,7 @@ pub extern "C" fn Servo_ComputedValues_Get(node: *mut RawGeckoNode)
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputedValues_GetForAnonymousBox(parent_style_or_null: ServoComputedValuesBorrowed,
+pub extern "C" fn Servo_ComputedValues_GetForAnonymousBox(parent_style_or_null: ServoComputedValuesMaybeBorrowed,
                                                          pseudo_tag: *mut nsIAtom,
                                                          raw_data: RawServoStyleSetBorrowedMut)
      -> ServoComputedValuesStrong {
@@ -266,13 +268,13 @@ pub extern "C" fn Servo_ComputedValues_GetForAnonymousBox(parent_style_or_null:
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputedValues_GetForPseudoElement(parent_style: ServoComputedValuesBorrowed,
-                                                          match_element: *mut RawGeckoElement,
-                                                          pseudo_tag: *mut nsIAtom,
-                                                          raw_data: RawServoStyleSetBorrowedMut,
-                                                          is_probe: bool)
+pub extern "C" fn Servo_ComputedValues_GetForPseudoElement(parent_style: ServoComputedValuesMaybeBorrowed,
+                                                           match_element: RawGeckoElementBorrowed,
+                                                           pseudo_tag: *mut nsIAtom,
+                                                           raw_data: RawServoStyleSetBorrowedMut,
+                                                           is_probe: bool)
      -> ServoComputedValuesStrong {
-    debug_assert!(!match_element.is_null());
+    debug_assert!(!(match_element as *const _).is_null());
 
     let parent_or_null = || {
         if is_probe {
@@ -289,7 +291,7 @@ pub extern "C" fn Servo_ComputedValues_GetForPseudoElement(parent_style: ServoCo
     let data = PerDocumentStyleData::from_ffi_mut(raw_data);
     data.flush_stylesheets();
 
-    let element = unsafe { GeckoElement::from_raw(match_element) };
+    let element = unsafe { GeckoElement(match_element) };
 
 
     match GeckoSelectorImpl::pseudo_element_cascade_type(&pseudo) {
@@ -315,7 +317,7 @@ pub extern "C" fn Servo_ComputedValues_GetForPseudoElement(parent_style: ServoCo
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputedValues_Inherit(parent_style: ServoComputedValuesBorrowed)
+pub extern "C" fn Servo_ComputedValues_Inherit(parent_style: ServoComputedValuesMaybeBorrowed)
      -> ServoComputedValuesStrong {
     let style = if parent_style.is_null() {
         Arc::new(ComputedValues::initial_values().clone())
@@ -326,12 +328,12 @@ pub extern "C" fn Servo_ComputedValues_Inherit(parent_style: ServoComputedValues
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputedValues_AddRef(ptr: ServoComputedValuesBorrowed) -> () {
+pub extern "C" fn Servo_ComputedValues_AddRef(ptr: ServoComputedValuesMaybeBorrowed) -> () {
     unsafe { ComputedValues::addref(ptr) };
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputedValues_Release(ptr: ServoComputedValuesBorrowed) -> () {
+pub extern "C" fn Servo_ComputedValues_Release(ptr: ServoComputedValuesMaybeBorrowed) -> () {
     unsafe { ComputedValues::release(ptr) };
 }
 
@@ -376,28 +378,28 @@ pub extern "C" fn Servo_ParseStyleAttribute(bytes: *const u8, length: u32,
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_AddRef(declarations: ServoDeclarationBlockBorrowed) {
+pub extern "C" fn Servo_DeclarationBlock_AddRef(declarations: ServoDeclarationBlockMaybeBorrowed) {
     unsafe { GeckoDeclarationBlock::addref(declarations) };
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_Release(declarations: ServoDeclarationBlockBorrowed) {
+pub extern "C" fn Servo_DeclarationBlock_Release(declarations: ServoDeclarationBlockMaybeBorrowed) {
     unsafe { GeckoDeclarationBlock::release(declarations) };
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_GetCache(declarations: ServoDeclarationBlockBorrowed)
+pub extern "C" fn Servo_DeclarationBlock_GetCache(declarations: ServoDeclarationBlockMaybeBorrowed)
                                                  -> *mut nsHTMLCSSStyleSheet {
     declarations.as_arc::<GeckoDeclarationBlock>().cache.load(Ordering::Relaxed)
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_SetImmutable(declarations: ServoDeclarationBlockBorrowed) {
+pub extern "C" fn Servo_DeclarationBlock_SetImmutable(declarations: ServoDeclarationBlockMaybeBorrowed) {
     declarations.as_arc::<GeckoDeclarationBlock>().immutable.store(true, Ordering::Relaxed)
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_ClearCachePointer(declarations: ServoDeclarationBlockBorrowed) {
+pub extern "C" fn Servo_DeclarationBlock_ClearCachePointer(declarations: ServoDeclarationBlockMaybeBorrowed) {
     declarations.as_arc::<GeckoDeclarationBlock>().cache.store(ptr::null_mut(), Ordering::Relaxed)
 }
 
@@ -417,12 +419,12 @@ pub extern "C" fn Servo_CSSSupports(property: *const u8, property_length: u32,
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_ComputeRestyleHint(element: *mut RawGeckoElement,
+pub extern "C" fn Servo_ComputeRestyleHint(element: RawGeckoElementBorrowed,
                                            snapshot: *mut ServoElementSnapshot,
-                                           raw_data: *mut RawServoStyleSet) -> nsRestyleHint {
-    let per_doc_data = unsafe { &mut *(raw_data as *mut PerDocumentStyleData) };
+                                           raw_data: RawServoStyleSetBorrowedMut) -> nsRestyleHint {
+    let per_doc_data = PerDocumentStyleData::from_ffi_mut(raw_data);
     let snapshot = unsafe { GeckoElementSnapshot::from_raw(snapshot) };
-    let element = unsafe { GeckoElement::from_raw(element) };
+    let element = unsafe { GeckoElement(element) };
 
     // NB: This involves an FFI call, we can get rid of it easily if needed.
     let current_state = element.get_state();

ports/geckolib/wrapper.rs

@@ -23,6 +23,8 @@ use gecko_bindings::bindings::{Gecko_IsLink, Gecko_IsRootElement, Gecko_IsTextNo
 use gecko_bindings::bindings::{Gecko_IsUnvisitedLink, Gecko_IsVisitedLink};
 use gecko_bindings::bindings::{Gecko_LocalName, Gecko_Namespace, Gecko_NodeIsElement, Gecko_SetNodeData};
 use gecko_bindings::bindings::{RawGeckoDocument, RawGeckoElement, RawGeckoNode};
+use gecko_bindings::bindings::RawGeckoDocumentBorrowed;
+use gecko_bindings::bindings::{RawGeckoElementBorrowed, RawGeckoNodeBorrowed};
 use gecko_bindings::structs::{NODE_HAS_DIRTY_DESCENDANTS_FOR_SERVO, NODE_IS_DIRTY_FOR_SERVO};
 use gecko_bindings::structs::{nsIAtom, nsChangeHint, nsStyleContext};
 use gecko_bindings::sugar::ownership::Borrowed;
@@ -74,35 +76,20 @@ impl NonOpaqueStyleData {
 // could implement refcounting if need be (at a potentially non-trivial
 // performance cost) by implementing Drop and making LayoutFoo non-Copy.
 #[derive(Clone, Copy)]
-pub struct GeckoNode<'ln> {
-    node: *mut RawGeckoNode,
-    chain: PhantomData<&'ln ()>,
-}
+pub struct GeckoNode<'ln>(pub &'ln RawGeckoNode);
 
 impl<'ln> GeckoNode<'ln> {
-    pub unsafe fn from_raw(n: *mut RawGeckoNode) -> GeckoNode<'ln> {
-        GeckoNode {
-            node: n,
-            chain: PhantomData,
-        }
-    }
-
-    unsafe fn from_ref(n: &RawGeckoNode) -> GeckoNode<'ln> {
-        GeckoNode::from_raw(n as *const RawGeckoNode as *mut RawGeckoNode)
-    }
-
     fn get_node_data(&self) -> Borrowed<NonOpaqueStyleData> {
-        unsafe {
-            // XXXManishearth should GeckoNode just contain an &'ln RawGeckoNode?
-            Borrowed::from_ffi(Gecko_GetNodeData(&*self.node))
-        }
+            unsafe {
+                Borrowed::from_ffi(Gecko_GetNodeData(&*self.0))
+            }
     }
 
     pub fn initialize_data(self) {
         unsafe {
             if self.get_node_data().is_null() {
                 let ptr = Box::new(NonOpaqueStyleData::new());
-                Gecko_SetNodeData(&mut *self.node, ptr.into_ffi().maybe());
+                Gecko_SetNodeData(self.0, ptr.into_ffi().maybe());
             }
         }
     }
@@ -149,22 +136,22 @@ impl<'ln> TNode for GeckoNode<'ln> {
     type ConcreteChildrenIterator = GeckoChildrenIterator<'ln>;
 
     fn to_unsafe(&self) -> UnsafeNode {
-        (self.node as usize, 0)
+        (self.0 as *const _ as usize, 0)
     }
 
     unsafe fn from_unsafe(n: &UnsafeNode) -> Self {
-        GeckoNode::from_raw(n.0 as *mut RawGeckoNode)
+        GeckoNode(&*(n.0 as *mut RawGeckoNode))
     }
 
     fn is_text_node(&self) -> bool {
         unsafe {
-            Gecko_IsTextNode(self.node)
+            Gecko_IsTextNode(self.0)
         }
     }
 
     fn is_element(&self) -> bool {
         unsafe {
-            Gecko_NodeIsElement(self.node)
+            Gecko_NodeIsElement(self.0)
         }
     }
 
@@ -177,7 +164,7 @@ impl<'ln> TNode for GeckoNode<'ln> {
     }
 
     fn children(self) -> GeckoChildrenIterator<'ln> {
-        let maybe_iter = unsafe { Gecko_MaybeCreateStyleChildrenIterator(self.node) };
+        let maybe_iter = unsafe { Gecko_MaybeCreateStyleChildrenIterator(self.0) };
         if !maybe_iter.is_null() {
             GeckoChildrenIterator::GeckoIterator(maybe_iter)
         } else {
@@ -186,7 +173,7 @@ impl<'ln> TNode for GeckoNode<'ln> {
     }
 
     fn opaque(&self) -> OpaqueNode {
-        let ptr: uintptr_t = self.node as uintptr_t;
+        let ptr: uintptr_t = self.0 as *const _ as uintptr_t;
         OpaqueNode(ptr)
     }
 
@@ -204,7 +191,7 @@ impl<'ln> TNode for GeckoNode<'ln> {
 
     fn as_element(&self) -> Option<GeckoElement<'ln>> {
         if self.is_element() {
-            unsafe { Some(GeckoElement::from_raw(self.node as *mut RawGeckoElement)) }
+            unsafe { Some(GeckoElement(&*(self.0 as *const _ as *const RawGeckoElement))) }
         } else {
             None
         }
@@ -229,15 +216,15 @@ impl<'ln> TNode for GeckoNode<'ln> {
             return true;
         }
 
-        let flags = unsafe { Gecko_GetNodeFlags(self.node) };
+        let flags = unsafe { Gecko_GetNodeFlags(self.0) };
         flags & (NODE_IS_DIRTY_FOR_SERVO as u32) != 0
     }
 
     unsafe fn set_dirty(&self, value: bool) {
         if value {
-            Gecko_SetNodeFlags(self.node, NODE_IS_DIRTY_FOR_SERVO as u32)
+            Gecko_SetNodeFlags(self.0, NODE_IS_DIRTY_FOR_SERVO as u32)
         } else {
-            Gecko_UnsetNodeFlags(self.node, NODE_IS_DIRTY_FOR_SERVO as u32)
+            Gecko_UnsetNodeFlags(self.0, NODE_IS_DIRTY_FOR_SERVO as u32)
         }
     }
 
@@ -247,15 +234,15 @@ impl<'ln> TNode for GeckoNode<'ln> {
         if self.get_node_data().is_null() {
             return true;
         }
-        let flags = unsafe { Gecko_GetNodeFlags(self.node) };
+        let flags = unsafe { Gecko_GetNodeFlags(self.0) };
         flags & (NODE_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32) != 0
     }
 
     unsafe fn set_dirty_descendants(&self, value: bool) {
         if value {
-            Gecko_SetNodeFlags(self.node, NODE_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32)
+            Gecko_SetNodeFlags(self.0, NODE_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32)
         } else {
-            Gecko_UnsetNodeFlags(self.node, NODE_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32)
+            Gecko_UnsetNodeFlags(self.0, NODE_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32)
         }
     }
 
@@ -292,36 +279,36 @@ impl<'ln> TNode for GeckoNode<'ln> {
     }
 
     fn set_restyle_damage(self, damage: Self::ConcreteRestyleDamage) {
-        unsafe { Gecko_StoreStyleDifference(self.node, damage.0) }
+        unsafe { Gecko_StoreStyleDifference(self.0, damage.0) }
     }
 
     fn parent_node(&self) -> Option<GeckoNode<'ln>> {
         unsafe {
-            Gecko_GetParentNode(self.node).as_ref().map(|n| GeckoNode::from_ref(n))
+            Gecko_GetParentNode(self.0).borrow_opt().map(|n| GeckoNode(n))
         }
     }
 
     fn first_child(&self) -> Option<GeckoNode<'ln>> {
         unsafe {
-            Gecko_GetFirstChild(self.node).as_ref().map(|n| GeckoNode::from_ref(n))
+            Gecko_GetFirstChild(self.0).borrow_opt().map(|n| GeckoNode(n))
         }
     }
 
     fn last_child(&self) -> Option<GeckoNode<'ln>> {
         unsafe {
-            Gecko_GetLastChild(self.node).as_ref().map(|n| GeckoNode::from_ref(n))
+            Gecko_GetLastChild(self.0).borrow_opt().map(|n| GeckoNode(n))
         }
     }
 
     fn prev_sibling(&self) -> Option<GeckoNode<'ln>> {
         unsafe {
-            Gecko_GetPrevSibling(self.node).as_ref().map(|n| GeckoNode::from_ref(n))
+            Gecko_GetPrevSibling(self.0).borrow_opt().map(|n| GeckoNode(n))
         }
     }
 
     fn next_sibling(&self) -> Option<GeckoNode<'ln>> {
         unsafe {
-            Gecko_GetNextSibling(self.node).as_ref().map(|n| GeckoNode::from_ref(n))
+            Gecko_GetNextSibling(self.0).borrow_opt().map(|n| GeckoNode(n))
         }
     }
 
@@ -337,7 +324,7 @@ impl<'ln> TNode for GeckoNode<'ln> {
         unsafe {
             let atom_ptr = pseudo.map(|p| p.as_atom().as_ptr())
                                  .unwrap_or(ptr::null_mut());
-            let context_ptr = Gecko_GetStyleContext(self.node, atom_ptr);
+            let context_ptr = Gecko_GetStyleContext(self.0, atom_ptr);
             context_ptr.as_ref()
         }
     }
@@ -389,38 +376,26 @@ impl<'a> Iterator for GeckoChildrenIterator<'a> {
 }
 
 #[derive(Clone, Copy)]
-pub struct GeckoDocument<'ld> {
-    document: *mut RawGeckoDocument,
-    chain: PhantomData<&'ld ()>,
-}
-
-impl<'ld> GeckoDocument<'ld> {
-    pub unsafe fn from_raw(doc: *mut RawGeckoDocument) -> GeckoDocument<'ld> {
-        GeckoDocument {
-            document: doc,
-            chain: PhantomData,
-        }
-    }
-}
+pub struct GeckoDocument<'ld>(pub &'ld RawGeckoDocument);
 
 impl<'ld> TDocument for GeckoDocument<'ld> {
     type ConcreteNode = GeckoNode<'ld>;
     type ConcreteElement = GeckoElement<'ld>;
 
     fn as_node(&self) -> GeckoNode<'ld> {
-        unsafe { GeckoNode::from_raw(self.document as *mut RawGeckoNode) }
+        unsafe { GeckoNode(&*(self.0 as *const _ as *const RawGeckoNode)) }
     }
 
     fn root_node(&self) -> Option<GeckoNode<'ld>> {
         unsafe {
-            Gecko_GetDocumentElement(self.document).as_ref().map(|el| GeckoElement::from_ref(el).as_node())
+            Gecko_GetDocumentElement(self.0).borrow_opt().map(|el| GeckoElement(el).as_node())
         }
     }
 
     fn drain_modified_elements(&self) -> Vec<(GeckoElement<'ld>, GeckoElementSnapshot)> {
         unimplemented!()
         /*
-        let elements =  unsafe { self.document.drain_modified_elements() };
+        let elements =  unsafe { self.0.drain_modified_elements() };
         elements.into_iter().map(|(el, snapshot)| (ServoLayoutElement::from_layout_js(el), snapshot)).collect()*/
     }
     fn will_paint(&self) { unimplemented!() }
@@ -428,10 +403,7 @@ impl<'ld> TDocument for GeckoDocument<'ld> {
 }
 
 #[derive(Clone, Copy)]
-pub struct GeckoElement<'le> {
-    element: *mut RawGeckoElement,
-    chain: PhantomData<&'le ()>,
-}
+pub struct GeckoElement<'le>(pub &'le RawGeckoElement);
 
 impl<'le> fmt::Debug for GeckoElement<'le> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
@@ -444,17 +416,6 @@ impl<'le> fmt::Debug for GeckoElement<'le> {
 }
 
 impl<'le> GeckoElement<'le> {
-    pub unsafe fn from_raw(el: *mut RawGeckoElement) -> GeckoElement<'le> {
-        GeckoElement {
-            element: el,
-            chain: PhantomData,
-        }
-    }
-
-    unsafe fn from_ref(el: &RawGeckoElement) -> GeckoElement<'le> {
-        GeckoElement::from_raw(el as *const RawGeckoElement as *mut RawGeckoElement)
-    }
-
     pub fn parse_style_attribute(value: &str) -> Option<PropertyDeclarationBlock> {
         // FIXME(bholley): Real base URL and error reporter.
         let base_url = &*DUMMY_BASE_URL;
@@ -476,11 +437,11 @@ impl<'le> TElement for GeckoElement<'le> {
     type ConcreteDocument = GeckoDocument<'le>;
 
     fn as_node(&self) -> Self::ConcreteNode {
-        unsafe { GeckoNode::from_raw(self.element as *mut RawGeckoNode) }
+        unsafe { GeckoNode(&*(self.0 as *const _ as *const RawGeckoNode)) }
     }
 
     fn style_attribute(&self) -> Option<&Arc<PropertyDeclarationBlock>> {
-        let declarations = unsafe { Gecko_GetServoDeclarationBlock(self.element) };
+        let declarations = unsafe { Gecko_GetServoDeclarationBlock(self.0) };
         if declarations.is_null() {
             None
         } else {
@@ -491,14 +452,14 @@ impl<'le> TElement for GeckoElement<'le> {
 
     fn get_state(&self) -> ElementState {
         unsafe {
-            ElementState::from_bits_truncate(Gecko_ElementState(self.element) as u16)
+            ElementState::from_bits_truncate(Gecko_ElementState(self.0) as u16)
         }
     }
 
     #[inline]
     fn has_attr(&self, namespace: &Namespace, attr: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_HasAttr(self.element,
+            bindings::Gecko_HasAttr(self.0,
                                     namespace.0.as_ptr(),
                                     attr.as_ptr())
         }
@@ -507,7 +468,7 @@ impl<'le> TElement for GeckoElement<'le> {
     #[inline]
     fn attr_equals(&self, namespace: &Namespace, attr: &Atom, val: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrEquals(self.element,
+            bindings::Gecko_AttrEquals(self.0,
                                        namespace.0.as_ptr(),
                                        attr.as_ptr(),
                                        val.as_ptr(),
@@ -518,7 +479,7 @@ impl<'le> TElement for GeckoElement<'le> {
 
 impl<'le> PartialEq for GeckoElement<'le> {
     fn eq(&self, other: &Self) -> bool {
-        self.element == other.element
+        self.0 as *const _ == other.0 as *const _
     }
 }
 
@@ -533,37 +494,37 @@ impl<'le> PresentationalHintsSynthetizer for GeckoElement<'le> {
 impl<'le> ::selectors::Element for GeckoElement<'le> {
     fn parent_element(&self) -> Option<Self> {
         unsafe {
-            Gecko_GetParentElement(self.element).as_ref().map(|el| GeckoElement::from_ref(el))
+            Gecko_GetParentElement(self.0).borrow_opt().map(|el| GeckoElement(el))
         }
     }
 
     fn first_child_element(&self) -> Option<Self> {
         unsafe {
-            Gecko_GetFirstChildElement(self.element).as_ref().map(|el| GeckoElement::from_ref(el))
+            Gecko_GetFirstChildElement(self.0).borrow_opt().map(|el| GeckoElement(el))
         }
     }
 
     fn last_child_element(&self) -> Option<Self> {
         unsafe {
-            Gecko_GetLastChildElement(self.element).as_ref().map(|el| GeckoElement::from_ref(el))
+            Gecko_GetLastChildElement(self.0).borrow_opt().map(|el| GeckoElement(el))
         }
     }
 
     fn prev_sibling_element(&self) -> Option<Self> {
         unsafe {
-            Gecko_GetPrevSiblingElement(self.element).as_ref().map(|el| GeckoElement::from_ref(el))
+            Gecko_GetPrevSiblingElement(self.0).borrow_opt().map(|el| GeckoElement(el))
         }
     }
 
     fn next_sibling_element(&self) -> Option<Self> {
         unsafe {
-            Gecko_GetNextSiblingElement(self.element).as_ref().map(|el| GeckoElement::from_ref(el))
+            Gecko_GetNextSiblingElement(self.0).borrow_opt().map(|el| GeckoElement(el))
         }
     }
 
     fn is_root(&self) -> bool {
         unsafe {
-            Gecko_IsRootElement(self.element)
+            Gecko_IsRootElement(self.0)
         }
     }
 
@@ -574,22 +535,22 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
 
     fn get_local_name(&self) -> &WeakAtom {
         unsafe {
-            WeakAtom::new(Gecko_LocalName(self.element))
+            WeakAtom::new(Gecko_LocalName(self.0))
         }
     }
 
     fn get_namespace(&self) -> &WeakNamespace {
         unsafe {
-            WeakNamespace::new(Gecko_Namespace(self.element))
+            WeakNamespace::new(Gecko_Namespace(self.0))
         }
     }
 
     fn match_non_ts_pseudo_class(&self, pseudo_class: NonTSPseudoClass) -> bool {
         match pseudo_class {
             // https://github.com/servo/servo/issues/8718
-            NonTSPseudoClass::AnyLink => unsafe { Gecko_IsLink(self.element) },
-            NonTSPseudoClass::Link => unsafe { Gecko_IsUnvisitedLink(self.element) },
-            NonTSPseudoClass::Visited => unsafe { Gecko_IsVisitedLink(self.element) },
+            NonTSPseudoClass::AnyLink => unsafe { Gecko_IsLink(self.0) },
+            NonTSPseudoClass::Link => unsafe { Gecko_IsUnvisitedLink(self.0) },
+            NonTSPseudoClass::Visited => unsafe { Gecko_IsVisitedLink(self.0) },
             NonTSPseudoClass::Active |
             NonTSPseudoClass::Focus |
             NonTSPseudoClass::Hover |
@@ -608,7 +569,7 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
 
     fn get_id(&self) -> Option<Atom> {
         let ptr = unsafe {
-            bindings::Gecko_AtomAttrValue(self.element,
+            bindings::Gecko_AtomAttrValue(self.0,
                                           atom!("id").as_ptr())
         };
 
@@ -620,7 +581,7 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
     }
 
     fn has_class(&self, name: &Atom) -> bool {
-        snapshot_helpers::has_class(self.element,
+        snapshot_helpers::has_class(self.0,
                                     name,
                                     Gecko_ClassOrClassList)
     }
@@ -628,14 +589,14 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
     fn each_class<F>(&self, callback: F)
         where F: FnMut(&Atom)
     {
-        snapshot_helpers::each_class(self.element,
+        snapshot_helpers::each_class(self.0,
                                      callback,
                                      Gecko_ClassOrClassList)
     }
 
     fn is_html_element_in_html_document(&self) -> bool {
         unsafe {
-            Gecko_IsHTMLElementInHTMLDocument(self.element)
+            Gecko_IsHTMLElementInHTMLDocument(self.0)
         }
     }
 }
@@ -667,14 +628,14 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
 
     fn match_attr_has(&self, attr: &AttrSelector<Self::Impl>) -> bool {
         unsafe {
-            bindings::Gecko_HasAttr(self.element,
+            bindings::Gecko_HasAttr(self.0,
                                     attr.ns_or_null(),
                                     attr.select_name(self.is_html_element_in_html_document()))
         }
     }
     fn match_attr_equals(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrEquals(self.element,
+            bindings::Gecko_AttrEquals(self.0,
                                        attr.ns_or_null(),
                                        attr.select_name(self.is_html_element_in_html_document()),
                                        value.as_ptr(),
@@ -683,7 +644,7 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
     }
     fn match_attr_equals_ignore_ascii_case(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrEquals(self.element,
+            bindings::Gecko_AttrEquals(self.0,
                                        attr.ns_or_null(),
                                        attr.select_name(self.is_html_element_in_html_document()),
                                        value.as_ptr(),
@@ -692,7 +653,7 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
     }
     fn match_attr_includes(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrIncludes(self.element,
+            bindings::Gecko_AttrIncludes(self.0,
                                          attr.ns_or_null(),
                                          attr.select_name(self.is_html_element_in_html_document()),
                                          value.as_ptr())
@@ -700,7 +661,7 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
     }
     fn match_attr_dash(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrDashEquals(self.element,
+            bindings::Gecko_AttrDashEquals(self.0,
                                            attr.ns_or_null(),
                                            attr.select_name(self.is_html_element_in_html_document()),
                                            value.as_ptr())
@@ -708,7 +669,7 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
     }
     fn match_attr_prefix(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrHasPrefix(self.element,
+            bindings::Gecko_AttrHasPrefix(self.0,
                                           attr.ns_or_null(),
                                           attr.select_name(self.is_html_element_in_html_document()),
                                           value.as_ptr())
@@ -716,7 +677,7 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
     }
     fn match_attr_substring(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrHasSubstring(self.element,
+            bindings::Gecko_AttrHasSubstring(self.0,
                                              attr.ns_or_null(),
                                              attr.select_name(self.is_html_element_in_html_document()),
                                              value.as_ptr())
@@ -724,7 +685,7 @@ impl<'le> ::selectors::MatchAttr for GeckoElement<'le> {
     }
     fn match_attr_suffix(&self, attr: &AttrSelector<Self::Impl>, value: &Atom) -> bool {
         unsafe {
-            bindings::Gecko_AttrHasSuffix(self.element,
+            bindings::Gecko_AttrHasSuffix(self.0,
                                           attr.ns_or_null(),
                                           attr.select_name(self.is_html_element_in_html_document()),
                                           value.as_ptr())