Auto merge of #17086 - upsuper:bug1352968, r=heycam

Add CSSOM support of @import rule for stylo

This is the Servo side change of [bug 1352968](https://bugzilla.mozilla.org/show_bug.cgi?id=1352968).

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/17086)
<!-- Reviewable:end -->

components/style/gecko/generated/bindings.rs

@@ -1739,10 +1739,6 @@ extern "C" {
                                           quirks_mode: nsCompatibility)
      -> RawServoStyleSheetStrong;
 }
-extern "C" {
-    pub fn Servo_ImportRule_GetSheet(import_rule: RawServoImportRuleBorrowed)
-     -> RawServoStyleSheetStrong;
-}
 extern "C" {
     pub fn Servo_StyleSheet_ClearAndUpdate(stylesheet:
                                                RawServoStyleSheetBorrowed,
@@ -1873,6 +1869,20 @@ extern "C" {
     pub fn Servo_StyleRule_GetCssText(rule: RawServoStyleRuleBorrowed,
                                       result: *mut nsAString);
 }
+extern "C" {
+    pub fn Servo_CssRules_GetImportRuleAt(rules: ServoCssRulesBorrowed,
+                                          index: u32, line: *mut u32,
+                                          column: *mut u32)
+     -> RawServoImportRuleStrong;
+}
+extern "C" {
+    pub fn Servo_ImportRule_Debug(rule: RawServoImportRuleBorrowed,
+                                  result: *mut nsACString);
+}
+extern "C" {
+    pub fn Servo_ImportRule_GetCssText(rule: RawServoImportRuleBorrowed,
+                                       result: *mut nsAString);
+}
 extern "C" {
     pub fn Servo_Keyframe_Debug(rule: RawServoKeyframeBorrowed,
                                 result: *mut nsACString);
@@ -2000,6 +2010,14 @@ extern "C" {
     pub fn Servo_StyleRule_GetSelectorText(rule: RawServoStyleRuleBorrowed,
                                            result: *mut nsAString);
 }
+extern "C" {
+    pub fn Servo_ImportRule_GetHref(rule: RawServoImportRuleBorrowed,
+                                    result: *mut nsAString);
+}
+extern "C" {
+    pub fn Servo_ImportRule_GetSheet(rule: RawServoImportRuleBorrowed)
+     -> *const RawServoStyleSheet;
+}
 extern "C" {
     pub fn Servo_Keyframe_GetKeyText(keyframe: RawServoKeyframeBorrowed,
                                      result: *mut nsAString);

components/style/gecko/generated/structs_debug.rs

@@ -1555,11 +1555,6 @@ pub mod root {
                 _unused: [u8; 0],
             }
             #[repr(C)]
-            #[derive(Debug, Copy, Clone)]
-            pub struct ImportRule {
-                _unused: [u8; 0],
-            }
-            #[repr(C)]
             #[derive(Debug)]
             pub struct Rule {
                 pub _base: root::nsIDOMCSSRule,
@@ -3349,6 +3344,11 @@ pub mod root {
             }
             #[repr(C)]
             #[derive(Debug, Copy, Clone)]
+            pub struct CSSImportRule {
+                _unused: [u8; 0],
+            }
+            #[repr(C)]
+            #[derive(Debug, Copy, Clone)]
             pub struct CSSRuleList {
                 _unused: [u8; 0],
             }
@@ -6692,6 +6692,7 @@ pub mod root {
             pub mTitle: ::nsstring::nsStringRepr,
             pub mDocument: *mut root::nsIDocument,
             pub mOwningNode: *mut root::nsINode,
+            pub mOwnerRule: *mut root::mozilla::dom::CSSImportRule,
             pub mMedia: root::RefPtr<root::mozilla::dom::MediaList>,
             pub mNext: root::RefPtr<root::mozilla::StyleSheet>,
             pub mParsingMode: root::mozilla::css::SheetParsingMode,
@@ -6786,7 +6787,7 @@ pub mod root {
         }
         #[test]
         fn bindgen_test_layout_StyleSheet() {
-            assert_eq!(::std::mem::size_of::<StyleSheet>() , 152usize , concat
+            assert_eq!(::std::mem::size_of::<StyleSheet>() , 160usize , concat
                        ! ( "Size of: " , stringify ! ( StyleSheet ) ));
             assert_eq! (::std::mem::align_of::<StyleSheet>() , 8usize , concat
                         ! ( "Alignment of " , stringify ! ( StyleSheet ) ));

components/style/gecko/generated/structs_release.rs

@@ -1479,11 +1479,6 @@ pub mod root {
                 _unused: [u8; 0],
             }
             #[repr(C)]
-            #[derive(Debug, Copy, Clone)]
-            pub struct ImportRule {
-                _unused: [u8; 0],
-            }
-            #[repr(C)]
             #[derive(Debug)]
             pub struct Rule {
                 pub _base: root::nsIDOMCSSRule,
@@ -3254,6 +3249,11 @@ pub mod root {
             }
             #[repr(C)]
             #[derive(Debug, Copy, Clone)]
+            pub struct CSSImportRule {
+                _unused: [u8; 0],
+            }
+            #[repr(C)]
+            #[derive(Debug, Copy, Clone)]
             pub struct CSSRuleList {
                 _unused: [u8; 0],
             }
@@ -6562,6 +6562,7 @@ pub mod root {
             pub mTitle: ::nsstring::nsStringRepr,
             pub mDocument: *mut root::nsIDocument,
             pub mOwningNode: *mut root::nsINode,
+            pub mOwnerRule: *mut root::mozilla::dom::CSSImportRule,
             pub mMedia: root::RefPtr<root::mozilla::dom::MediaList>,
             pub mNext: root::RefPtr<root::mozilla::StyleSheet>,
             pub mParsingMode: root::mozilla::css::SheetParsingMode,
@@ -6656,7 +6657,7 @@ pub mod root {
         }
         #[test]
         fn bindgen_test_layout_StyleSheet() {
-            assert_eq!(::std::mem::size_of::<StyleSheet>() , 144usize , concat
+            assert_eq!(::std::mem::size_of::<StyleSheet>() , 152usize , concat
                        ! ( "Size of: " , stringify ! ( StyleSheet ) ));
             assert_eq! (::std::mem::align_of::<StyleSheet>() , 8usize , concat
                         ! ( "Alignment of " , stringify ! ( StyleSheet ) ));

components/style/stylesheets.rs

@@ -633,6 +633,9 @@ pub struct ImportRule {
     /// It contains an empty list of rules and namespace set that is updated
     /// when it loads.
     pub stylesheet: Arc<Stylesheet>,
+
+    /// The line and column of the rule's source code.
+    pub source_location: SourceLocation,
 }
 
 impl Clone for ImportRule {
@@ -641,6 +644,7 @@ impl Clone for ImportRule {
         ImportRule {
             url: self.url.clone(),
             stylesheet: Arc::new(stylesheet.clone()),
+            source_location: self.source_location.clone(),
         }
     }
 }
@@ -1530,6 +1534,8 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
 
     fn parse_prelude(&mut self, name: &str, input: &mut Parser)
                      -> Result<AtRuleType<AtRulePrelude, CssRule>, ()> {
+        let location = get_location_with_offset(input.current_source_location(),
+                                                self.context.line_number_offset);
         match_ignore_ascii_case! { name,
             "import" => {
                 if self.state.get() <= State::Imports {
@@ -1561,7 +1567,8 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                                 dirty_on_viewport_size_change: AtomicBool::new(false),
                                 disabled: AtomicBool::new(false),
                                 quirks_mode: self.context.quirks_mode,
-                            })
+                            }),
+                            source_location: location,
                         }
                     }, &mut |import_rule| {
                         Arc::new(self.shared_lock.wrap(import_rule))
@@ -1576,9 +1583,6 @@ impl<'a> AtRuleParser for TopLevelRuleParser<'a> {
                 if self.state.get() <= State::Namespaces {
                     self.state.set(State::Namespaces);
 
-                    let location = get_location_with_offset(input.current_source_location(),
-                                                            self.context.line_number_offset);
-
                     let prefix_result = input.try(|input| input.expect_ident());
                     let url = Namespace::from(try!(input.expect_url_or_string()));
 

ports/geckolib/glue.rs

@@ -30,6 +30,7 @@ use style::gecko_bindings::bindings::{RawGeckoElementBorrowed, RawGeckoElementBo
 use style::gecko_bindings::bindings::{RawGeckoKeyframeListBorrowed, RawGeckoKeyframeListBorrowedMut};
 use style::gecko_bindings::bindings::{RawServoDeclarationBlockBorrowed, RawServoDeclarationBlockStrong};
 use style::gecko_bindings::bindings::{RawServoDocumentRule, RawServoDocumentRuleBorrowed};
+use style::gecko_bindings::bindings::{RawServoImportRule, RawServoImportRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoKeyframe, RawServoKeyframeBorrowed, RawServoKeyframeStrong};
 use style::gecko_bindings::bindings::{RawServoKeyframesRule, RawServoKeyframesRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoMediaList, RawServoMediaListBorrowed, RawServoMediaListStrong};
@@ -56,8 +57,8 @@ use style::gecko_bindings::bindings::RawGeckoServoStyleRuleListBorrowedMut;
 use style::gecko_bindings::bindings::RawServoAnimationValueBorrowed;
 use style::gecko_bindings::bindings::RawServoAnimationValueMapBorrowedMut;
 use style::gecko_bindings::bindings::RawServoAnimationValueStrong;
-use style::gecko_bindings::bindings::RawServoImportRuleBorrowed;
 use style::gecko_bindings::bindings::RawServoStyleRuleBorrowed;
+use style::gecko_bindings::bindings::RawServoStyleSheet;
 use style::gecko_bindings::bindings::ServoComputedValuesBorrowedOrNull;
 use style::gecko_bindings::bindings::nsTArrayBorrowed_uintptr_t;
 use style::gecko_bindings::bindings::nsTimingFunctionBorrowed;
@@ -988,6 +989,12 @@ impl_basic_rule_funcs! { (Style, StyleRule, RawServoStyleRule),
     to_css: Servo_StyleRule_GetCssText,
 }
 
+impl_basic_rule_funcs! { (Import, ImportRule, RawServoImportRule),
+    getter: Servo_CssRules_GetImportRuleAt,
+    debug: Servo_ImportRule_Debug,
+    to_css: Servo_ImportRule_GetCssText,
+}
+
 impl_basic_rule_funcs_without_getter! { (Keyframe, RawServoKeyframe),
     debug: Servo_Keyframe_Debug,
     to_css: Servo_Keyframe_GetCssText,
@@ -1077,6 +1084,20 @@ pub extern "C" fn Servo_StyleRule_GetSelectorText(rule: RawServoStyleRuleBorrowe
     })
 }
 
+#[no_mangle]
+pub extern "C" fn Servo_ImportRule_GetHref(rule: RawServoImportRuleBorrowed, result: *mut nsAString) {
+    read_locked_arc(rule, |rule: &ImportRule| {
+        write!(unsafe { &mut *result }, "{}", rule.url.as_str()).unwrap();
+    })
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_ImportRule_GetSheet(rule: RawServoImportRuleBorrowed) -> *const RawServoStyleSheet {
+    read_locked_arc(rule, |rule: &ImportRule| {
+        rule.stylesheet.as_borrowed_opt().unwrap() as *const _
+    })
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_Keyframe_GetKeyText(keyframe: RawServoKeyframeBorrowed, result: *mut nsAString) {
     read_locked_arc(keyframe, |keyframe: &Keyframe| {
@@ -2294,15 +2315,6 @@ pub extern "C" fn Servo_NoteExplicitHints(element: RawGeckoElementBorrowed,
     }
 }
 
-#[no_mangle]
-pub extern "C" fn Servo_ImportRule_GetSheet(import_rule:
-                                            RawServoImportRuleBorrowed)
-                                            -> RawServoStyleSheetStrong {
-    read_locked_arc(import_rule, |rule: &ImportRule| {
-        rule.stylesheet.clone().into_strong()
-    })
-}
-
 #[no_mangle]
 pub extern "C" fn Servo_TakeChangeHint(element: RawGeckoElementBorrowed) -> nsChangeHint
 {