Auto merge of #7391 - jdm:prefs, r=Ms2ger

Replace catch-all experimental flag with fine-grained boolean prefere…

…nces initialized from a JSON document.

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/7391)
<!-- Reviewable:end -->

components/compositing/constellation.rs

@@ -54,8 +54,8 @@ use style::viewport::ViewportConstraints;
 use url::Url;
 use util::cursor::Cursor;
 use util::geometry::PagePx;
-use util::opts;
 use util::task::spawn_named;
+use util::{opts, prefs};
 
 /// Maintains the pipelines and navigation context and grants permission to composite.
 ///
@@ -891,7 +891,7 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
                                    containing_pipeline_id: PipelineId,
                                    subpage_id: SubpageId,
                                    event: MozBrowserEvent) {
-        assert!(opts::experimental_enabled());
+        assert!(prefs::get_pref("dom.mozbrowser.enabled", false));
 
         // Find the script channel for the given parent pipeline,
         // and pass the event to that script task.
@@ -1373,7 +1373,7 @@ impl<LTF: LayoutTaskFactory, STF: ScriptTaskFactory> Constellation<LTF, STF> {
 
     // https://developer.mozilla.org/en-US/docs/Web/Events/mozbrowserlocationchange
     fn trigger_mozbrowserlocationchange(&self, pipeline_id: PipelineId) {
-        if opts::experimental_enabled() {
+        if prefs::get_pref("dom.mozbrowser.enabled", false) {
             // Work around borrow checker
             let event_info = {
                 let pipeline = self.pipeline(pipeline_id);

components/compositing/pipeline.rs

@@ -31,7 +31,7 @@ use url::Url;
 use util;
 use util::geometry::{PagePx, ViewportPx};
 use util::ipc::OptionalIpcSender;
-use util::opts;
+use util::prefs;
 
 /// A uniquely-identifiable pipeline of script task, layout task, and paint task.
 pub struct Pipeline {
@@ -269,7 +269,7 @@ impl Pipeline {
     pub fn trigger_mozbrowser_event(&self,
                                      subpage_id: SubpageId,
                                      event: MozBrowserEvent) {
-        assert!(opts::experimental_enabled());
+        assert!(prefs::get_pref("dom.mozbrowser.enabled", false));
 
         let event = ConstellationControlMsg::MozBrowserEvent(self.id,
                                                              subpage_id,

components/script/dom/document.rs

@@ -50,7 +50,7 @@ use dom::htmlcollection::{HTMLCollection, CollectionFilter};
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
 use dom::htmlheadelement::HTMLHeadElement;
 use dom::htmlhtmlelement::HTMLHtmlElement;
-use dom::htmliframeelement::HTMLIFrameElement;
+use dom::htmliframeelement::{self, HTMLIFrameElement};
 use dom::htmlscriptelement::HTMLScriptElement;
 use dom::keyboardevent::KeyboardEvent;
 use dom::location::Location;
@@ -79,7 +79,6 @@ use net_traits::CookieSource::NonHTTP;
 use net_traits::{Metadata, PendingAsyncLoad, AsyncResponseTarget};
 use script_task::Runnable;
 use script_traits::{MouseButton, UntrustedNodeAddress};
-use util::opts;
 use util::str::{DOMString, split_html_space_chars};
 
 use euclid::point::Point2D;
@@ -856,7 +855,7 @@ impl Document {
     }
 
     pub fn trigger_mozbrowser_event(&self, event: MozBrowserEvent) {
-        if opts::experimental_enabled() {
+        if htmliframeelement::mozbrowser_enabled() {
             let window = self.window.root();
 
             if let Some((containing_pipeline_id, subpage_id)) = window.r().parent_info() {

components/script/dom/htmliframeelement.rs

@@ -30,7 +30,7 @@ use msg::constellation_msg::IFrameSandboxState::{IFrameSandboxed, IFrameUnsandbo
 use msg::constellation_msg::Msg as ConstellationMsg;
 use msg::constellation_msg::{PipelineId, SubpageId, ConstellationChan, MozBrowserEvent, NavigationDirection};
 use string_cache::Atom;
-use util::opts;
+use util::prefs;
 use util::str::DOMString;
 
 use js::jsapi::{RootedValue, JSAutoRequest, JSAutoCompartment};
@@ -41,6 +41,10 @@ use std::cell::Cell;
 use url::{Url, UrlParser};
 use util::str::{self, LengthOrPercentageOrAuto};
 
+pub fn mozbrowser_enabled() -> bool {
+    prefs::get_pref("dom.mozbrowser.enabled", false)
+}
+
 #[derive(HeapSizeOf)]
 enum SandboxAllowance {
     AllowNothing = 0x00,
@@ -117,7 +121,7 @@ impl HTMLIFrameElement {
                                                             old_subpage_id,
                                                             sandboxed)).unwrap();
 
-        if opts::experimental_enabled() {
+        if mozbrowser_enabled() {
             // https://developer.mozilla.org/en-US/docs/Web/Events/mozbrowserloadstart
             self.dispatch_mozbrowser_event(MozBrowserEvent::LoadStart);
         }
@@ -136,7 +140,7 @@ impl HTMLIFrameElement {
         // TODO(gw): Support mozbrowser event types that have detail which is not a string.
         // See https://developer.mozilla.org/en-US/docs/Web/API/Using_the_Browser_API
         // for a list of mozbrowser events.
-        assert!(opts::experimental_enabled());
+        assert!(mozbrowser_enabled());
 
         if self.Mozbrowser() {
             let window = window_from_node(self);
@@ -298,7 +302,7 @@ impl HTMLIFrameElementMethods for HTMLIFrameElement {
 
     // https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#attr-mozbrowser
     fn Mozbrowser(&self) -> bool {
-        if opts::experimental_enabled() {
+        if mozbrowser_enabled() {
             let element = ElementCast::from_ref(self);
             element.has_attribute(&Atom::from_slice("mozbrowser"))
         } else {
@@ -308,7 +312,7 @@ impl HTMLIFrameElementMethods for HTMLIFrameElement {
 
     // https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#attr-mozbrowser
     fn SetMozbrowser(&self, value: bool) -> ErrorResult {
-        if opts::experimental_enabled() {
+        if mozbrowser_enabled() {
             let element = ElementCast::from_ref(self);
             element.set_bool_attribute(&Atom::from_slice("mozbrowser"), value);
         }

components/script/dom/mouseevent.rs

@@ -16,7 +16,7 @@ use dom::uievent::{UIEvent, UIEventTypeId};
 use dom::window::Window;
 use std::cell::Cell;
 use std::default::Default;
-use util::opts;
+use util::prefs;
 use util::str::DOMString;
 
 #[dom_struct]
@@ -171,7 +171,7 @@ impl MouseEventMethods for MouseEvent {
     // This returns the same result as current gecko.
     // https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/which
     fn Which(&self) -> i32 {
-        if opts::experimental_enabled() {
+        if prefs::get_pref("dom.mouseevent.which.enabled", false) {
             (self.button.get() + 1) as i32
         } else {
             0

components/style/properties.mako.rs

@@ -51,7 +51,7 @@ class Longhand(object):
         self.ident = to_rust_ident(name)
         self.camel_case = to_camel_case(self.ident)
         self.style_struct = THIS_STYLE_STRUCT
-        self.experimental = experimental
+        self.experimental = ("layout.%s.enabled" % name) if experimental else None
         self.custom_cascade = custom_cascade
         if derived_from is None:
             self.derived_from = None
@@ -64,7 +64,7 @@ class Shorthand(object):
         self.ident = to_rust_ident(name)
         self.camel_case = to_camel_case(self.ident)
         self.derived_from = None
-        self.experimental = experimental
+        self.experimental = ("layout.%s.enabled" % name) if experimental else None
         self.sub_properties = [LONGHANDS_BY_NAME[s] for s in sub_properties]
 
 class StyleStruct(object):
@@ -450,7 +450,9 @@ pub mod longhands {
                 % for value in values[:-1]:
                     "${value}" => {
                         % if value in experimental_values:
-                            if !::util::opts::experimental_enabled() { return Err(()) }
+                            if !::util::prefs::get_pref("layout.${value}.enabled", false) {
+                                return Err(())
+                            }
                         % endif
                         Ok(computed_value::T::${to_rust_ident(value)})
                     },
@@ -458,7 +460,9 @@ pub mod longhands {
                 % for value in values[-1:]:
                     "${value}" => {
                         % if value in experimental_values:
-                            if !::util::opts::experimental_enabled() { return Err(()) }
+                            if !::util::prefs::get_pref("layout.${value}.enabled", false) {
+                                return Err(())
+                            }
                         % endif
                         Ok(computed_value::T::${to_rust_ident(value)})
                     }
@@ -5720,7 +5724,7 @@ impl PropertyDeclaration {
                 % if property.derived_from is None:
                     "${property.name}" => {
                         % if property.experimental:
-                            if !::util::opts::experimental_enabled() {
+                            if !::util::prefs::get_pref("${property.experimental}", false) {
                                 return PropertyDeclarationParseResult::ExperimentalProperty
                             }
                         % endif
@@ -5739,7 +5743,7 @@ impl PropertyDeclaration {
             % for shorthand in SHORTHANDS:
                 "${shorthand.name}" => {
                     % if shorthand.experimental:
-                        if !::util::opts::experimental_enabled() {
+                        if !::util::prefs::get_pref("${shorthand.experimental}", false) {
                             return PropertyDeclarationParseResult::ExperimentalProperty
                         }
                     % endif

components/style/stylesheets.rs

@@ -429,7 +429,7 @@ impl<'a, 'b> AtRuleParser for NestedRuleParser<'a, 'b> {
                 Ok(AtRuleType::WithBlock(AtRulePrelude::FontFace))
             },
             "viewport" => {
-                if ::util::opts::experimental_enabled() {
+                if ::util::prefs::get_pref("layout.viewport.enabled", false) {
                     Ok(AtRuleType::WithBlock(AtRulePrelude::Viewport))
                 } else {
                     Err(())

components/util/lib.rs

@@ -60,6 +60,7 @@ pub mod logical_geometry;
 pub mod mem;
 pub mod opts;
 pub mod persistent_list;
+pub mod prefs;
 pub mod range;
 pub mod resource_files;
 pub mod str;

components/util/opts.rs

@@ -10,6 +10,7 @@ use geometry::ScreenPx;
 use euclid::size::{Size2D, TypedSize2D};
 use getopts::Options;
 use num_cpus;
+use prefs;
 use std::cmp;
 use std::default::Default;
 use std::env;
@@ -17,7 +18,6 @@ use std::fs::{File, PathExt};
 use std::io::{self, Read, Write};
 use std::path::Path;
 use std::process;
-use std::sync::atomic::{AtomicBool, Ordering, ATOMIC_BOOL_INIT};
 use url::{self, Url};
 
 /// Global flags for Servo, currently set on the command line.
@@ -50,9 +50,6 @@ pub struct Opts {
     /// and cause it to produce output on that interval (`-m`).
     pub mem_profiler_period: Option<f64>,
 
-    /// Enable experimental web features (`-e`).
-    pub enable_experimental: bool,
-
     /// The number of threads to use for layout (`-y`). Defaults to 1, which results in a recursive
     /// sequential algorithm.
     pub layout_threads: usize,
@@ -384,7 +381,6 @@ pub fn default_opts() -> Opts {
         device_pixels_per_px: None,
         time_profiler_period: None,
         mem_profiler_period: None,
-        enable_experimental: false,
         layout_threads: 1,
         nonincremental_layout: false,
         nossl: false,
@@ -434,7 +430,6 @@ pub fn from_cmdline_args(args: &[String]) {
     opts.optopt("o", "output", "Output file", "output.png");
     opts.optopt("s", "size", "Size of tiles", "512");
     opts.optopt("", "device-pixel-ratio", "Device pixels per px", "");
-    opts.optflag("e", "experimental", "Enable experimental web features");
     opts.optopt("t", "threads", "Number of paint threads", "1");
     opts.optflagopt("p", "profile", "Profiler flag and output interval", "10");
     opts.optflagopt("m", "memory-profile", "Memory profiler flag and output interval", "10");
@@ -461,6 +456,8 @@ pub fn from_cmdline_args(args: &[String]) {
     opts.optflag("h", "help", "Print this message");
     opts.optopt("", "resources-path", "Path to find static resources", "/home/servo/resources");
     opts.optflag("", "sniff-mime-types" , "Enable MIME sniffing");
+    opts.optmulti("", "pref",
+                  "A preference to set to enable", "dom.mozbrowser.enabled");
 
     let opt_match = match opts.parse(args) {
         Ok(m) => m,
@@ -589,7 +586,6 @@ pub fn from_cmdline_args(args: &[String]) {
         device_pixels_per_px: device_pixels_per_px,
         time_profiler_period: time_profiler_period,
         mem_profiler_period: mem_profiler_period,
-        enable_experimental: opt_match.opt_present("e"),
         layout_threads: layout_threads,
         nonincremental_layout: nonincremental_layout,
         nossl: nossl,
@@ -630,19 +626,12 @@ pub fn from_cmdline_args(args: &[String]) {
     };
 
     set_defaults(opts);
-}
 
-static EXPERIMENTAL_ENABLED: AtomicBool = ATOMIC_BOOL_INIT;
+    // This must happen after setting the default options, since the prefs rely on
-
+    // on the resource path.
-/// Turn on experimental features globally. Normally this is done
+    for pref in opt_match.opt_strs("pref").iter() {
-/// during initialization by `set` or `from_cmdline_args`, but
+        prefs::set_pref(pref, true);
-/// tests that require experimental features will also set it.
+    }
-pub fn set_experimental_enabled(new_value: bool) {
-    EXPERIMENTAL_ENABLED.store(new_value, Ordering::SeqCst);
-}
-
-pub fn experimental_enabled() -> bool {
-    EXPERIMENTAL_ENABLED.load(Ordering::SeqCst)
 }
 
 // Make Opts available globally. This saves having to clone and pass
@@ -653,7 +642,7 @@ const INVALID_OPTIONS: *mut Opts = 0x01 as *mut Opts;
 
 lazy_static! {
     static ref OPTIONS: Opts = {
-        let opts = unsafe {
+        unsafe {
             let initial = if !DEFAULT_OPTIONS.is_null() {
                 let opts = Box::from_raw(DEFAULT_OPTIONS);
                 *opts
@@ -662,9 +651,7 @@ lazy_static! {
             };
             DEFAULT_OPTIONS = INVALID_OPTIONS;
             initial
-        };
+        }
-        set_experimental_enabled(opts.enable_experimental);
-        opts
     };
 }
 

components/util/prefs.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 resource_files::resources_dir_path;
+use rustc_serialize::json::Json;
+use std::collections::HashMap;
+use std::fs::File;
+use std::sync::{Arc, Mutex};
+
+lazy_static! {
+    static ref PREFS: Arc<Mutex<HashMap<String, bool>>> = {
+        let prefs = read_prefs().unwrap_or(HashMap::new());
+        Arc::new(Mutex::new(prefs))
+    };
+}
+
+fn read_prefs() -> Result<HashMap<String, bool>, ()> {
+    let mut path = resources_dir_path();
+    path.push("prefs.json");
+
+    let mut file = try!(File::open(path).or_else(|e| {
+        println!("Error opening preferences: {:?}.", e);
+        Err(())
+    }));
+    let json = try!(Json::from_reader(&mut file).or_else(|e| {
+        println!("Ignoring invalid JSON in preferences: {:?}.", e);
+        Err(())
+    }));
+
+    let mut prefs = HashMap::new();
+    if let Some(obj) = json.as_object() {
+        for (name, value) in obj.iter() {
+            if let Some(bool_value) = value.as_boolean() {
+                prefs.insert(name.clone(), bool_value);
+            } else {
+                println!("Ignoring non-boolean preference value for {:?}", name);
+            }
+        }
+    }
+    Ok(prefs)
+}
+
+pub fn get_pref(name: &str, default: bool) -> bool {
+    *PREFS.lock().unwrap().get(name).unwrap_or(&default)
+}
+
+pub fn set_pref(name: &str, value: bool) {
+    let _ = PREFS.lock().unwrap().insert(name.to_owned(), value);
+}

resources/prefs.json

@@ -0,0 +1,13 @@
+{
+  "dom.mouseevent.which.enabled": false,
+  "dom.mozbrowser.enabled": false,
+  "layout.columns.enabled": false,
+  "layout.column-width.enabled": false,
+  "layout.column-count.enabled": false,
+  "layout.column-gap.enabled": false,
+  "layout.flex.enabled": false,
+  "layout.flex-direction.enabled": false,
+  "layout.text-orientation.enabled": false,
+  "layout.viewport.enabled": false,
+  "layout.writing-mode.enabled": false
+}

tests/ref/basic.list

@@ -98,8 +98,8 @@ flaky_cpu == append_style_a.html append_style_b.html
 == first_child_pseudo_a.html first_child_pseudo_b.html
 == first_of_type_pseudo_a.html first_of_type_pseudo_b.html
 == fixed_width_overrides_child_intrinsic_width_a.html fixed_width_overrides_child_intrinsic_width_ref.html
-experimental == flex_column_direction.html flex_column_direction_ref.html
+prefs:"layout.flex-direction.enabled,layout.flex.enabled" == flex_column_direction.html flex_column_direction_ref.html
-experimental == flex_row_direction.html flex_row_direction_ref.html
+prefs:"layout.flex.enabled" == flex_row_direction.html flex_row_direction_ref.html
 == float_clearance_a.html float_clearance_ref.html
 == float_clearance_intrinsic_width_a.html float_clearance_intrinsic_width_ref.html
 == float_intrinsic_height.html float_intrinsic_height_ref.html
@@ -138,7 +138,7 @@ experimental == flex_row_direction.html flex_row_direction_ref.html
 == iframe/simple_inline_width_height.html iframe/simple_inline_width_height_ref.html
 == iframe/simple_inline_width_percentage.html iframe/simple_inline_width_percentage_ref.html
 == iframe/size_attributes.html iframe/size_attributes_ref.html
-experimental == iframe/size_attributes_vertical_writing_mode.html iframe/size_attributes_vertical_writing_mode_ref.html
+prefs:"layout.writing-mode.enabled" == iframe/size_attributes_vertical_writing_mode.html iframe/size_attributes_vertical_writing_mode_ref.html
 == iframe/stacking_context.html iframe/stacking_context_ref.html
 
 != image_rendering_auto_a.html image_rendering_pixelated_a.html
@@ -357,7 +357,7 @@ flaky_cpu == linebreak_simple_a.html linebreak_simple_b.html
 == transform_simple_a.html transform_simple_ref.html
 == transform_stacking_context_a.html transform_stacking_context_ref.html
 == upper_id_attr.html upper_id_attr_ref.html
-flaky_cpu,experimental == vertical-lr-blocks.html vertical-lr-blocks_ref.html
+flaky_cpu,prefs:"layout.writing-mode.enabled" == vertical-lr-blocks.html vertical-lr-blocks_ref.html
 == vertical_align_bottom_a.html vertical_align_bottom_ref.html
 == vertical_align_inline_block_a.html vertical_align_inline_block_ref.html
 == vertical_align_inside_table_a.html vertical_align_inside_table_ref.html
@@ -373,7 +373,7 @@ resolution=800x600 == viewport_percentage_vmin_vmax.html viewport_percentage_vmi
 # resolution=600x800 == viewport_percentage_vmin_vmax.html viewport_percentage_vmin_vmax_b.html
 resolution=800x600 == viewport_percentage_vw_vh.html viewport_percentage_vw_vh_a.html
 # resolution=600x800 == viewport_percentage_vw_vh.html viewport_percentage_vw_vh_b.html
-experimental == viewport_rule.html viewport_rule_ref.html
+prefs:"layout.viewport.enabled" == viewport_rule.html viewport_rule_ref.html
 == visibility_hidden.html visibility_hidden_ref.html
 
 == webgl-context/clearcolor.html webgl-context/clearcolor_ref.html

tests/reftest.rs

@@ -140,7 +140,7 @@ struct Reftest {
     servo_args: Vec<String>,
     render_mode: RenderMode,
     is_flaky: bool,
-    experimental: bool,
+    prefs: Vec<String>,
     fragment_identifier: Option<String>,
     resolution: Option<String>,
 }
@@ -198,7 +198,7 @@ fn parse_lists(file: &Path, servo_args: &[String], render_mode: RenderMode, id_o
 
         let conditions_list = test_line.conditions.split(',');
         let mut flakiness = RenderMode::empty();
-        let mut experimental = false;
+        let mut prefs = vec![];
         let mut fragment_identifier = None;
         let mut resolution = None;
         for condition in conditions_list {
@@ -207,8 +207,12 @@ fn parse_lists(file: &Path, servo_args: &[String], render_mode: RenderMode, id_o
                 "flaky_gpu" => flakiness.insert(GPU_RENDERING),
                 "flaky_linux" => flakiness.insert(LINUX_TARGET),
                 "flaky_macos" => flakiness.insert(MACOS_TARGET),
-                "experimental" => experimental = true,
+                _ => ()
-                _ => (),
+            }
+            if condition.starts_with("prefs:\"") {
+                if let Some(joined) = condition.split("\"").nth(1) {
+                    prefs.extend(joined.split(",").map(str::to_owned));
+                }
             }
             if condition.starts_with("fragment=") {
                 fragment_identifier = Some(condition["fragment=".len()..].to_string());
@@ -226,7 +230,7 @@ fn parse_lists(file: &Path, servo_args: &[String], render_mode: RenderMode, id_o
             render_mode: render_mode,
             servo_args: servo_args.to_vec(),
             is_flaky: render_mode.intersects(flakiness),
-            experimental: experimental,
+            prefs: prefs,
             fragment_identifier: fragment_identifier,
             resolution: resolution,
         };
@@ -275,8 +279,9 @@ fn capture(reftest: &Reftest, side: usize) -> (u32, u32, Vec<u8>) {
     if reftest.render_mode.contains(GPU_RENDERING) {
         command.arg("-g");
     }
-    if reftest.experimental {
+    for pref in &reftest.prefs {
-        command.arg("--experimental");
+        command.arg("--pref");
+        command.arg(pref);
     }
     if let Some(ref resolution) = reftest.resolution {
         command.arg("--resolution");

tests/unit/style/viewport.rs

@@ -25,7 +25,7 @@ fn test_viewport_rule<F>(css: &str,
                          callback: F)
     where F: Fn(&Vec<ViewportDescriptorDeclaration>, &str)
 {
-    ::util::opts::set_experimental_enabled(true);
+    ::util::prefs::set_pref("layout.viewport.enabled", true);
 
     let stylesheet = stylesheet!(css, Author);
     let mut rule_count = 0;
@@ -172,7 +172,7 @@ fn cascading_within_viewport_rule() {
 
 #[test]
 fn multiple_stylesheets_cascading() {
-    ::util::opts::set_experimental_enabled(true);
+    ::util::prefs::set_pref("layout.viewport.enabled", true);
     let device = Device::new(MediaType::Screen, Size2D::typed(800., 600.));
 
     let stylesheets = vec![