style: Better debugging for stylesheets and URLs.

Bug: 1470145
Reviewed-by: xidorn
MozReview-Commit-ID: FIcz2K1ZYX0

components/style/error_reporting.rs

@@ -7,7 +7,6 @@
 #![deny(missing_docs)]
 
 use cssparser::{BasicParseErrorKind, ParseErrorKind, SourceLocation, Token};
-use log;
 use std::fmt;
 use style_traits::ParseError;
 use stylesheets::UrlExtraData;
@@ -229,8 +228,10 @@ pub trait ParseErrorReporter {
 /// This logging is silent by default, and can be enabled with a `RUST_LOG=style=info`
 /// environment variable.
 /// (See [`env_logger`](https://rust-lang-nursery.github.io/log/env_logger/).)
+#[cfg(feature = "servo")]
 pub struct RustLogReporter;
 
+#[cfg(feature = "servo")]
 impl ParseErrorReporter for RustLogReporter {
     fn report_error(
         &self,
@@ -238,6 +239,7 @@ impl ParseErrorReporter for RustLogReporter {
         location: SourceLocation,
         error: ContextualParseError,
     ) {
+        use log;
         if log_enabled!(log::Level::Info) {
             info!(
                 "Url:\t{}\n{}:{} {}",

components/style/gecko/data.rs

@@ -17,14 +17,25 @@ use media_queries::{Device, MediaList};
 use properties::ComputedValues;
 use selector_parser::SnapshotMap;
 use servo_arc::Arc;
+use std::fmt;
 use shared_lock::{Locked, SharedRwLockReadGuard, StylesheetGuards};
 use stylesheets::{CssRule, Origin, StylesheetContents, StylesheetInDocument};
 use stylist::Stylist;
 
 /// Little wrapper to a Gecko style sheet.
-#[derive(Debug, Eq, PartialEq)]
+#[derive(Eq, PartialEq)]
 pub struct GeckoStyleSheet(*const DomStyleSheet);
 
+impl fmt::Debug for GeckoStyleSheet {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let contents = self.contents();
+        formatter.debug_struct("GeckoStyleSheet")
+            .field("origin", &contents.origin)
+            .field("url_data", &*contents.url_data.read())
+            .finish()
+    }
+}
+
 impl ToMediaListKey for ::gecko::data::GeckoStyleSheet {
     fn to_media_list_key(&self) -> MediaListKey {
         use std::mem;

components/style/gecko/url.rs

@@ -6,7 +6,7 @@
 
 use cssparser::Parser;
 use gecko_bindings::bindings;
-use gecko_bindings::structs::{ServoBundledURI, URLExtraData};
+use gecko_bindings::structs::ServoBundledURI;
 use gecko_bindings::structs::mozilla::css::URLValueData;
 use gecko_bindings::structs::root::{RustString, nsStyleImageRequest};
 use gecko_bindings::structs::root::mozilla::css::{ImageValue, URLValue};
@@ -17,6 +17,7 @@ use parser::{Parse, ParserContext};
 use servo_arc::{Arc, RawOffsetArc};
 use std::fmt::{self, Write};
 use std::mem;
+use stylesheets::UrlExtraData;
 use style_traits::{CssWriter, ParseError, ToCss};
 use values::computed::{Context, ToComputedValue};
 
@@ -32,7 +33,7 @@ pub struct CssUrl {
 
     /// The URL extra data.
     #[css(skip)]
-    pub extra_data: RefPtr<URLExtraData>,
+    pub extra_data: UrlExtraData,
 }
 
 impl CssUrl {
@@ -58,7 +59,7 @@ impl CssUrl {
             &url.mString as *const _ as *const RawOffsetArc<String>;
         CssUrl {
             serialization: Arc::from_raw_offset((*arc_type).clone()),
-            extra_data: url.mExtraData.to_safe(),
+            extra_data: UrlExtraData(url.mExtraData.to_safe()),
         }
     }
 
@@ -88,7 +89,7 @@ impl CssUrl {
         let arc_offset = Arc::into_raw_offset(self.serialization.clone());
         ServoBundledURI {
             mURLString: unsafe { mem::transmute::<_, RawOffsetArc<RustString>>(arc_offset) },
-            mExtraData: self.extra_data.get(),
+            mExtraData: self.extra_data.0.get(),
         }
     }
 }

components/style/gecko_bindings/sugar/refptr.rs

@@ -78,15 +78,6 @@ impl<T: RefCounted> RefPtr<T> {
         ret
     }
 
-    /// Create a reference to RefPtr from a reference to pointer.
-    ///
-    /// The pointer must be valid and non null.
-    ///
-    /// This method doesn't touch refcount.
-    pub unsafe fn from_ptr_ref(ptr: &*mut T) -> &Self {
-        mem::transmute(ptr)
-    }
-
     /// Produces an FFI-compatible RefPtr that can be stored in style structs.
     ///
     /// structs::RefPtr does not have a destructor, so this may leak

components/style/stylesheets/mod.rs

@@ -61,22 +61,52 @@ pub type UrlExtraData = ::servo_url::ServoUrl;
 
 /// Extra data that the backend may need to resolve url values.
 #[cfg(feature = "gecko")]
-pub type UrlExtraData =
+#[derive(Clone, PartialEq)]
-    ::gecko_bindings::sugar::refptr::RefPtr<::gecko_bindings::structs::URLExtraData>;
+pub struct UrlExtraData(
+    pub ::gecko_bindings::sugar::refptr::RefPtr<::gecko_bindings::structs::URLExtraData>
+);
 
 #[cfg(feature = "gecko")]
 impl UrlExtraData {
-    /// Returns a string for the url.
+    /// True if this URL scheme is chrome.
-    ///
+    #[inline]
-    /// Unimplemented currently.
+    pub fn is_chrome(&self) -> bool {
-    pub fn as_str(&self) -> &str {
+        self.0.mIsChrome
-        // TODO
-        "(stylo: not supported)"
     }
 
-    /// True if this URL scheme is chrome.
+    /// Create a reference to this `UrlExtraData` from a reference to pointer.
-    pub fn is_chrome(&self) -> bool {
+    ///
-        self.mIsChrome
+    /// The pointer must be valid and non null.
+    ///
+    /// This method doesn't touch refcount.
+    #[inline]
+    pub unsafe fn from_ptr_ref(ptr: &*mut ::gecko_bindings::structs::URLExtraData) -> &Self {
+        ::std::mem::transmute(ptr)
+    }
+}
+
+#[cfg(feature = "gecko")]
+impl fmt::Debug for UrlExtraData {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        use gecko_bindings::{structs, bindings};
+
+        struct DebugURI(*mut structs::nsIURI);
+        impl fmt::Debug for DebugURI {
+            fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                use nsstring::nsCString;
+                let mut spec = nsCString::new();
+                unsafe {
+                    bindings::Gecko_nsIURI_Debug(self.0, &mut spec);
+                }
+                spec.fmt(formatter)
+            }
+        }
+
+        formatter.debug_struct("URLExtraData")
+            .field("is_chrome", &self.is_chrome())
+            .field("base", &DebugURI(self.0.mBaseURI.raw::<structs::nsIURI>()))
+            .field("referrer", &DebugURI(self.0.mReferrer.raw::<structs::nsIURI>()))
+            .finish()
     }
 }
 

components/style/stylesheets/stylesheet.rs

@@ -176,7 +176,7 @@ macro_rules! rule_filter {
 }
 
 /// A trait to represent a given stylesheet in a document.
-pub trait StylesheetInDocument {
+pub trait StylesheetInDocument : ::std::fmt::Debug {
     /// Get the stylesheet origin.
     fn origin(&self, guard: &SharedRwLockReadGuard) -> Origin;
 
@@ -263,7 +263,7 @@ impl StylesheetInDocument for Stylesheet {
 
 /// A simple wrapper over an `Arc<Stylesheet>`, with pointer comparison, and
 /// suitable for its use in a `StylesheetSet`.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub struct DocumentStyleSheet(
     #[cfg_attr(feature = "servo", ignore_malloc_size_of = "Arc")] pub Arc<Stylesheet>,