Merge mozilla-central to autoland. a=merge CLOSED TREE

Cargo.lock

@@ -2361,15 +2361,19 @@ name = "webrender_bindings"
 version = "0.1.0"
 dependencies = [
  "app_units 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bincode 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "dwrote 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.17.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "gleam 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nsstring 0.1.0",
  "rayon 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_profiler 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "uuid 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "webrender 0.57.2",
 ]
 

caps/nsScriptSecurityManager.cpp

@@ -1253,15 +1253,6 @@ nsScriptSecurityManager::GetDocShellCodebasePrincipal(nsIURI* aURI,
   return *aPrincipal ? NS_OK : NS_ERROR_FAILURE;
 }
 
-// static
-nsIPrincipal*
-nsScriptSecurityManager::doGetObjectPrincipal(JSObject *aObj)
-{
-    JSCompartment *compartment = js::GetObjectCompartment(aObj);
-    JSPrincipals *principals = JS_GetCompartmentPrincipals(compartment);
-    return nsJSPrincipals::get(principals);
-}
-
 NS_IMETHODIMP
 nsScriptSecurityManager::CanCreateWrapper(JSContext *cx,
                                           const nsIID &aIID,

caps/nsScriptSecurityManager.h

@@ -93,10 +93,6 @@ private:
     static bool
     JSPrincipalsSubsume(JSPrincipals *first, JSPrincipals *second);
 
-    // Returns null if a principal cannot be found; generally callers
-    // should error out at that point.
-    static nsIPrincipal* doGetObjectPrincipal(JSObject* obj);
-
     nsresult
     Init();
 

devtools/client/debugger/new/README.mozilla

@@ -1,9 +1,9 @@
 This is the debugger.html project output.
 See https://github.com/devtools-html/debugger.html
 
-Version 60
+Version 61
 
-Comparison: https://github.com/devtools-html/debugger.html/compare/release-59...release-60
+Comparison: https://github.com/devtools-html/debugger.html/compare/release-60...release-61
 
 Packages:
 - babel-plugin-transform-es2015-modules-commonjs @6.26.2

devtools/client/debugger/new/dist/debugger.css

@@ -2117,6 +2117,10 @@ menuseparator {
   padding: 0 2px;
 }
 
+.objectBox-node.clickable {
+  cursor: pointer;
+}
+
 /******************************************************************************/
 
 .objectBox-event,
@@ -2223,6 +2227,7 @@ button.open-inspector {
   height: 16px;
   margin-left: 0.25em;
   vertical-align: middle;
+  cursor: pointer;
 }
 
 .objectBox-node:hover .open-inspector,

devtools/client/debugger/new/dist/parser-worker.js

@@ -1222,7 +1222,7 @@ function isYieldExpression(path) {
 }
 
 function isObjectShorthand(parent) {
-  return t.isObjectProperty(parent) && parent.key.start == parent.value.start && parent.key.loc.identifierName === parent.value.loc.identifierName;
+  return t.isObjectProperty(parent) && parent.value && parent.key.start == parent.value.start && parent.key.loc.identifierName === parent.value.loc.identifierName;
 }
 
 function getObjectExpressionValue(node) {

devtools/client/debugger/new/dist/vendors.js

@@ -8174,7 +8174,7 @@ function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj;
 // (eg. "my-module/Test") which is why they are nested in "vendored".
 // The keys of the vendored object should match the module names
 // !!! Should remain synchronized with .babel/transform-mc.js !!!
-const vendored = {
+const vendored = exports.vendored = {
   classnames: _classnames2.default,
   "devtools-components": devtoolsComponents,
   "devtools-config": devtoolsConfig,
@@ -8210,7 +8210,6 @@ const vendored = {
  */
 
 // Modules imported with destructuring
-exports.vendored = vendored;
 
 /***/ }),
 

devtools/client/debugger/new/src/actions/pause/extra.js

@@ -91,7 +91,7 @@ function getExtra(expression, result) {
     const selectedFrame = (0, _selectors.getSelectedFrame)(getState());
 
     if (!selectedFrame) {
-      return;
+      return {};
     }
 
     const extra = await getExtraProps(getState, expression, result, expr => client.evaluateInFrame(expr, selectedFrame.id));

devtools/client/debugger/new/src/client/index.js

@@ -3,7 +3,7 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-exports.onConnect = undefined;
+exports.onConnect = onConnect;
 
 var _firefox = require("./firefox");
 
@@ -68,6 +68,4 @@ async function onConnect(connection, {
     selectors,
     client: commands
   };
-}
-
-exports.onConnect = onConnect;
+}

devtools/client/debugger/new/src/components/Editor/Preview/Popup.js

@@ -237,7 +237,7 @@ class Popup extends _react.Component {
       roots = roots.filter(r => r.type != NODE_TYPES.PROTOTYPE);
     }
 
-    if ((0, _preview.isReactComponent)(this.getObjectProperties())) {
+    if (extra.react && (0, _preview.isReactComponent)(this.getObjectProperties())) {
       header = this.renderReact(extra.react);
       roots = roots.filter(r => ["state", "props"].includes(r.name));
     }

devtools/client/debugger/new/src/components/PrimaryPanes/SourcesTree.js

@@ -124,6 +124,18 @@ class SourcesTree extends _react.Component {
     }
   }
 
+  // NOTE: we get the source from sources because item.contents is cached
+  getSource(item) {
+    return this.props.sources.get(item.contents.id);
+  }
+
+  isEmpty() {
+    const {
+      sourceTree
+    } = this.state;
+    return sourceTree.contents.length === 0;
+  }
+
   renderItemName(name) {
     const hosts = {
       "ng://": "Angular",
@@ -135,69 +147,56 @@ class SourcesTree extends _react.Component {
 
   renderEmptyElement(message) {
     return _react2.default.createElement("div", {
+      key: "empty",
       className: "no-sources-message"
     }, message);
   }
 
-  render() {
+  renderProjectRootHeader() {
     const {
-      expanded,
       projectRoot
     } = this.props;
     const {
-      focusedItem,
-      highlightItems,
-      listItems,
-      parentMap,
       sourceTree
     } = this.state;
 
-    const onExpand = (item, expandedState) => {
-      this.props.setExpandedState(expandedState);
-    };
-
-    const onCollapse = (item, expandedState) => {
-      this.props.setExpandedState(expandedState);
-    };
-
-    const isEmpty = sourceTree.contents.length === 0;
-    const isCustomRoot = projectRoot !== "";
-
-    let roots = () => sourceTree.contents;
-
-    let clearProjectRootButton = null; // The "sourceTree.contents[0]" check ensures that there are contents
-    // A custom root with no existing sources will be ignored
-
-    if (isCustomRoot) {
-      const sourceContents = sourceTree.contents[0];
-      let rootLabel = projectRoot.split("/").pop();
-
-      roots = () => sourceContents.contents;
-
-      if (sourceContents && sourceContents.name !== rootLabel) {
-        rootLabel = sourceContents.contents[0].name;
-
-        roots = () => sourceContents.contents[0].contents;
-      }
-
-      clearProjectRootButton = _react2.default.createElement("button", {
-        className: "sources-clear-root",
-        onClick: () => this.props.clearProjectDirectoryRoot(),
-        title: L10N.getStr("removeDirectoryRoot.label")
-      }, _react2.default.createElement(_Svg2.default, {
-        name: "home"
-      }), _react2.default.createElement(_Svg2.default, {
-        name: "breadcrumb",
-        "class": true
-      }), _react2.default.createElement("span", {
-        className: "sources-clear-root-label"
-      }, rootLabel));
+    if (!projectRoot) {
+      return null;
     }
 
-    if (isEmpty && !isCustomRoot) {
-      return this.renderEmptyElement(L10N.getStr("sources.noSourcesAvailable"));
+    const sourceContents = sourceTree.contents[0];
+    let rootLabel = projectRoot.split("/").pop();
+
+    if (sourceContents && sourceContents.name !== rootLabel) {
+      rootLabel = sourceContents.contents[0].name;
     }
 
+    return _react2.default.createElement("div", {
+      key: "root",
+      className: "sources-clear-root-container"
+    }, _react2.default.createElement("button", {
+      className: "sources-clear-root",
+      onClick: () => this.props.clearProjectDirectoryRoot(),
+      title: L10N.getStr("removeDirectoryRoot.label")
+    }, _react2.default.createElement(_Svg2.default, {
+      name: "home"
+    }), _react2.default.createElement(_Svg2.default, {
+      name: "breadcrumb",
+      "class": true
+    }), _react2.default.createElement("span", {
+      className: "sources-clear-root-label"
+    }, rootLabel)));
+  }
+
+  renderTree() {
+    const {
+      expanded
+    } = this.props;
+    const {
+      highlightItems,
+      listItems,
+      parentMap
+    } = this.state;
     const treeProps = {
       autoExpandAll: false,
       autoExpandDepth: expanded ? 0 : 1,
@@ -205,35 +204,49 @@ class SourcesTree extends _react.Component {
       getChildren: item => (0, _sourcesTree.nodeHasChildren)(item) ? item.contents : [],
       getParent: item => parentMap.get(item),
       getPath: this.getPath,
-      getRoots: roots,
+      getRoots: this.getRoots,
       highlightItems,
       itemHeight: 21,
-      key: isEmpty ? "empty" : "full",
+      key: this.isEmpty() ? "empty" : "full",
       listItems,
-      onCollapse,
-      onExpand,
+      onCollapse: this.onCollapse,
+      onExpand: this.onExpand,
       onFocus: this.focusItem,
       renderItem: this.renderItem
     };
+    return _react2.default.createElement(_ManagedTree2.default, treeProps);
+  }
 
-    const tree = _react2.default.createElement(_ManagedTree2.default, treeProps);
-
-    const onKeyDown = e => {
-      if (e.keyCode === 13 && focusedItem) {
-        this.selectItem(focusedItem);
-      }
-    };
-
+  renderPane(...children) {
+    const {
+      projectRoot
+    } = this.props;
     return _react2.default.createElement("div", {
+      key: "pane",
       className: (0, _classnames2.default)("sources-pane", {
-        "sources-list-custom-root": isCustomRoot
+        "sources-list-custom-root": projectRoot
       })
-    }, isCustomRoot ? _react2.default.createElement("div", {
-      className: "sources-clear-root-container"
-    }, clearProjectRootButton) : null, isEmpty ? this.renderEmptyElement(L10N.getStr("sources.noSourcesAvailableRoot")) : _react2.default.createElement("div", {
+    }, children);
+  }
+
+  render() {
+    const {
+      projectRoot
+    } = this.props;
+
+    if (this.isEmpty()) {
+      if (projectRoot) {
+        return this.renderPane(this.renderProjectRootHeader(), this.renderEmptyElement(L10N.getStr("sources.noSourcesAvailableRoot")));
+      }
+
+      return this.renderPane(this.renderEmptyElement(L10N.getStr("sources.noSourcesAvailable")));
+    }
+
+    return this.renderPane(this.renderProjectRootHeader(), _react2.default.createElement("div", {
+      key: "tree",
       className: "sources-list",
-      onKeyDown: onKeyDown
-    }, tree));
+      onKeyDown: this.onKeyDown
+    }, this.renderTree()));
   }
 
 }
@@ -246,25 +259,21 @@ var _initialiseProps = function () {
   };
 
   this.selectItem = item => {
-    if (!(0, _sourcesTree.nodeHasChildren)(item)) {
-      this.props.selectLocation({
-        sourceId: item.contents.get("id")
-      });
+    if (!(0, _sourcesTree.isDirectory)(item)) {
+      this.props.selectSource(item.contents.id);
     }
   };
 
   this.getPath = item => {
-    const {
-      sources
-    } = this.props;
-    const obj = item.contents.get && item.contents.get("id");
-    let blackBoxedPart = "";
+    const path = `${item.path}/${item.name}`;
 
-    if (typeof obj !== "undefined" && sources.has(obj) && sources.get(obj).get("isBlackBoxed")) {
-      blackBoxedPart = "update";
+    if ((0, _sourcesTree.isDirectory)(item)) {
+      return path;
     }
 
-    return `${item.path}/${item.name}/${blackBoxedPart}`;
+    const source = this.getSource(item);
+    const blackBoxedPart = source.isBlackBoxed ? ":blackboxed" : "";
+    return `${path}${blackBoxedPart}`;
   };
 
   this.getIcon = (sources, item, depth) => {
@@ -295,17 +304,15 @@ var _initialiseProps = function () {
       });
     }
 
-    if (!(0, _sourcesTree.nodeHasChildren)(item)) {
-      const obj = item.contents.get("id");
-      const source = sources.get(obj);
-      const className = (0, _classnames2.default)((0, _source.getSourceClassnames)(source), "source-icon");
+    if ((0, _sourcesTree.isDirectory)(item)) {
       return _react2.default.createElement("img", {
-        className: className
+        className: "folder"
       });
     }
 
+    const source = this.getSource(item);
     return _react2.default.createElement("img", {
-      className: "folder"
+      className: (0, _classnames2.default)((0, _source.getSourceClassnames)(source), "source-icon")
     });
   };
 
@@ -320,13 +327,12 @@ var _initialiseProps = function () {
     const menuOptions = [];
 
     if (!(0, _sourcesTree.isDirectory)(item)) {
-      const source = item.contents.get("url");
       const copySourceUri2 = {
         id: "node-menu-copy-source",
         label: copySourceUri2Label,
         accesskey: copySourceUri2Key,
         disabled: false,
-        click: () => (0, _clipboard.copyToTheClipboard)(source)
+        click: () => (0, _clipboard.copyToTheClipboard)(item.contents.url)
       };
       menuOptions.push(copySourceUri2);
     }
@@ -360,6 +366,24 @@ var _initialiseProps = function () {
     (0, _devtoolsContextmenu.showMenu)(event, menuOptions);
   };
 
+  this.onExpand = (item, expandedState) => {
+    this.props.setExpandedState(expandedState);
+  };
+
+  this.onCollapse = (item, expandedState) => {
+    this.props.setExpandedState(expandedState);
+  };
+
+  this.onKeyDown = e => {
+    const {
+      focusedItem
+    } = this.state;
+
+    if (e.keyCode === 13 && focusedItem) {
+      this.selectItem(focusedItem);
+    }
+  };
+
   this.renderItem = (item, depth, focused, _, expanded, {
     setExpanded
   }) => {
@@ -393,6 +417,28 @@ var _initialiseProps = function () {
       className: "label"
     }, " ", this.renderItemName(item.name), " "));
   };
+
+  this.getRoots = () => {
+    const {
+      projectRoot
+    } = this.props;
+    const {
+      sourceTree
+    } = this.state;
+    const sourceContents = sourceTree.contents[0];
+    const rootLabel = projectRoot.split("/").pop(); // The "sourceTree.contents[0]" check ensures that there are contents
+    // A custom root with no existing sources will be ignored
+
+    if (projectRoot) {
+      if (sourceContents && sourceContents.name !== rootLabel) {
+        return sourceContents.contents[0].contents;
+      }
+
+      return sourceContents.contents;
+    }
+
+    return sourceTree.contents;
+  };
 };
 
 const mapStateToProps = state => {
@@ -408,7 +454,7 @@ const mapStateToProps = state => {
 
 const actionCreators = {
   setExpandedState: _sourceTree.setExpandedState,
-  selectLocation: _sources.selectLocation,
+  selectSource: _sources.selectSource,
   setProjectDirectoryRoot: _ui.setProjectDirectoryRoot,
   clearProjectDirectoryRoot: _ui.clearProjectDirectoryRoot
 };

devtools/client/debugger/new/src/utils/editor/source-documents.js

@@ -3,7 +3,17 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-exports.showLoading = exports.showErrorMessage = exports.showSourceText = exports.clearEditor = exports.updateDocument = exports.updateLineNumberFormat = exports.clearDocuments = exports.removeDocument = exports.hasDocument = exports.setDocument = exports.getDocument = undefined;
+exports.getDocument = getDocument;
+exports.hasDocument = hasDocument;
+exports.setDocument = setDocument;
+exports.removeDocument = removeDocument;
+exports.clearDocuments = clearDocuments;
+exports.updateLineNumberFormat = updateLineNumberFormat;
+exports.updateDocument = updateDocument;
+exports.clearEditor = clearEditor;
+exports.showLoading = showLoading;
+exports.showErrorMessage = showErrorMessage;
+exports.showSourceText = showSourceText;
 
 var _source = require("../source");
 
@@ -168,16 +178,4 @@ function showSourceText(editor, source, symbols) {
   setEditorText(editor, source);
   editor.setMode((0, _source.getMode)(source, symbols));
   updateLineNumberFormat(editor, source.id);
-}
-
-exports.getDocument = getDocument;
-exports.setDocument = setDocument;
-exports.hasDocument = hasDocument;
-exports.removeDocument = removeDocument;
-exports.clearDocuments = clearDocuments;
-exports.updateLineNumberFormat = updateLineNumberFormat;
-exports.updateDocument = updateDocument;
-exports.clearEditor = clearEditor;
-exports.showSourceText = showSourceText;
-exports.showErrorMessage = showErrorMessage;
-exports.showLoading = showLoading;
+}

devtools/client/debugger/new/src/utils/path.js

@@ -3,6 +3,11 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
+exports.basename = basename;
+exports.dirname = dirname;
+exports.isURL = isURL;
+exports.isAbsolute = isAbsolute;
+exports.join = join;
 
 /* 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
@@ -26,10 +31,4 @@ function isAbsolute(str) {
 
 function join(base, dir) {
   return `${base}/${dir}`;
-}
-
-exports.basename = basename;
-exports.dirname = dirname;
-exports.isURL = isURL;
-exports.isAbsolute = isAbsolute;
-exports.join = join;
+}

devtools/client/debugger/new/src/utils/result-list.js

@@ -3,7 +3,7 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-exports.scrollList = undefined;
+exports.scrollList = scrollList;
 
 var _devtoolsEnvironment = require("devtools/client/debugger/new/dist/vendors").vendored["devtools-environment"];
 
@@ -53,6 +53,4 @@ function chromeScrollList(elem, index) {
   const itemOffset = resultsHeight % itemHeight;
   const scroll = positionsToScroll * (itemHeight + 2) + itemOffset;
   resultsEl.scrollTop = Math.max(0, scroll);
-}
-
-exports.scrollList = scrollList;
+}

devtools/client/debugger/new/src/utils/source.js

@@ -426,17 +426,12 @@ function isLoading(source) {
 }
 
 function getTextAtPosition(source, location) {
-  if (!source || !source.text) {
+  if (!source || !source.text || source.isWasm) {
     return "";
   }
 
   const line = location.line;
   const column = location.column || 0;
-
-  if (source.isWasm) {
-    return "";
-  }
-
   const lineText = source.text.split("\n")[line - 1];
 
   if (!lineText) {
@@ -466,5 +461,5 @@ function getSourceClassnames(source, sourceMetaData) {
     return "blackBox";
   }
 
-  return sourceTypes[(0, _sourcesTree.getExtension)(source.url)] || defaultClassName;
+  return sourceTypes[(0, _sourcesTree.getFileExtension)(source.url)] || defaultClassName;
 }

devtools/client/debugger/new/src/utils/sources-tree/addToTree.js

@@ -129,7 +129,7 @@ function addSourceToNode(node, url, source) {
 
 
 function addToTree(tree, source, debuggeeUrl, projectRoot) {
-  const url = (0, _getURL.getURL)(source.get("url"), debuggeeUrl);
+  const url = (0, _getURL.getURL)(source.get ? source.get("url") : source.url, debuggeeUrl);
   const debuggeeHost = (0, _treeOrder.getDomain)(debuggeeUrl);
 
   if ((0, _utils.isInvalidUrl)(url, source) || !isUnderRoot(url, projectRoot)) {

devtools/client/debugger/new/src/utils/sources-tree/index.js

@@ -102,6 +102,12 @@ Object.defineProperty(exports, "createParentMap", {
     return _utils.createParentMap;
   }
 });
+Object.defineProperty(exports, "getFileExtension", {
+  enumerable: true,
+  get: function () {
+    return _utils.getFileExtension;
+  }
+});
 Object.defineProperty(exports, "getRelativePath", {
   enumerable: true,
   get: function () {
@@ -131,10 +137,4 @@ Object.defineProperty(exports, "nodeHasChildren", {
   get: function () {
     return _utils.nodeHasChildren;
   }
-});
-Object.defineProperty(exports, "getExtension", {
-  enumerable: true,
-  get: function () {
-    return _utils.getExtension;
-  }
 });

devtools/client/debugger/new/src/utils/sources-tree/utils.js

@@ -6,7 +6,7 @@ Object.defineProperty(exports, "__esModule", {
 exports.nodeHasChildren = nodeHasChildren;
 exports.isExactUrlMatch = isExactUrlMatch;
 exports.isDirectory = isDirectory;
-exports.getExtension = getExtension;
+exports.getFileExtension = getFileExtension;
 exports.isNotJavaScript = isNotJavaScript;
 exports.isInvalidUrl = isInvalidUrl;
 exports.partIsFile = partIsFile;
@@ -47,7 +47,7 @@ function isDirectory(url) {
   return (parts.length === 0 || url.path.slice(-1) === "/" || nodeHasChildren(url)) && url.name != "(index)";
 }
 
-function getExtension(url = "") {
+function getFileExtension(url = "") {
   const parsedUrl = (0, _url.parse)(url).pathname;
 
   if (!parsedUrl) {
@@ -58,11 +58,11 @@ function getExtension(url = "") {
 }
 
 function isNotJavaScript(source) {
-  return ["css", "svg", "png"].includes(getExtension(source.url));
+  return ["css", "svg", "png"].includes(getFileExtension(source.url));
 }
 
 function isInvalidUrl(url, source) {
-  return IGNORED_URLS.indexOf(url) != -1 || !source.get("url") || !url.group || (0, _source.isPretty)(source) || isNotJavaScript(source);
+  return IGNORED_URLS.indexOf(url) != -1 || !(source.get ? source.get("url") : source.url) || !url.group || (0, _source.isPretty)(source) || isNotJavaScript(source);
 }
 
 function partIsFile(index, parts, url) {

devtools/client/debugger/new/src/utils/task.js

@@ -15,7 +15,7 @@ Object.defineProperty(exports, "__esModule", {
 /**
  * This object provides the public module functions.
  */
-const Task = {
+const Task = exports.Task = {
   // XXX: Not sure if this works in all cases...
   async: function (task) {
     return function () {
@@ -49,5 +49,4 @@ const Task = {
       callNext(undefined);
     });
   }
-};
-exports.Task = Task;
+};

devtools/client/debugger/new/src/utils/text.js

@@ -3,7 +3,8 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-exports.truncateMiddleText = exports.formatKeyShortcut = undefined;
+exports.formatKeyShortcut = formatKeyShortcut;
+exports.truncateMiddleText = truncateMiddleText;
 
 var _devtoolsModules = require("devtools/client/debugger/new/dist/vendors").vendored["devtools-modules"];
 
@@ -59,7 +60,4 @@ function truncateMiddleText(sourceText, maxLength) {
   }
 
   return truncatedText;
-}
-
-exports.formatKeyShortcut = formatKeyShortcut;
-exports.truncateMiddleText = truncateMiddleText;
+}

devtools/client/debugger/new/src/utils/utils.js

@@ -3,6 +3,10 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
+exports.handleError = handleError;
+exports.promisify = promisify;
+exports.endTruncateStr = endTruncateStr;
+exports.waitForMs = waitForMs;
 
 /* 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
@@ -54,9 +58,4 @@ function endTruncateStr(str, size) {
 
 function waitForMs(ms) {
   return new Promise(resolve => setTimeout(resolve, ms));
-}
-
-exports.handleError = handleError;
-exports.promisify = promisify;
-exports.endTruncateStr = endTruncateStr;
-exports.waitForMs = waitForMs;
+}

devtools/client/debugger/new/src/utils/wasm.js

@@ -3,7 +3,13 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-exports.renderWasmText = exports.clearWasmStates = exports.wasmOffsetToLine = exports.lineToWasmOffset = exports.isWasm = exports.getWasmLineNumberFormatter = exports.getWasmText = undefined;
+exports.getWasmText = getWasmText;
+exports.getWasmLineNumberFormatter = getWasmLineNumberFormatter;
+exports.isWasm = isWasm;
+exports.lineToWasmOffset = lineToWasmOffset;
+exports.wasmOffsetToLine = wasmOffsetToLine;
+exports.clearWasmStates = clearWasmStates;
+exports.renderWasmText = renderWasmText;
 
 var _WasmParser = require("devtools/client/shared/vendor/WasmParser");
 
@@ -179,12 +185,4 @@ function renderWasmText(sourceId, {
   }
 
   return lines;
-}
-
-exports.getWasmText = getWasmText;
-exports.getWasmLineNumberFormatter = getWasmLineNumberFormatter;
-exports.isWasm = isWasm;
-exports.lineToWasmOffset = lineToWasmOffset;
-exports.wasmOffsetToLine = wasmOffsetToLine;
-exports.clearWasmStates = clearWasmStates;
-exports.renderWasmText = renderWasmText;
+}

devtools/client/debugger/new/src/workers/parser/utils/helpers.js

@@ -56,7 +56,7 @@ function isYieldExpression(path) {
 }
 
 function isObjectShorthand(parent) {
-  return t.isObjectProperty(parent) && parent.key.start == parent.value.start && parent.key.loc.identifierName === parent.value.loc.identifierName;
+  return t.isObjectProperty(parent) && parent.value && parent.key.start == parent.value.start && parent.key.loc.identifierName === parent.value.loc.identifierName;
 }
 
 function getObjectExpressionValue(node) {

devtools/client/shared/components/reps/reps.css

@@ -226,6 +226,10 @@ html[dir="rtl"] .tree-node img.arrow {
   padding: 0 2px;
 }
 
+.objectBox-node.clickable {
+  cursor: pointer;
+}
+
 /******************************************************************************/
 
 .objectBox-event,
@@ -332,6 +336,7 @@ button.open-inspector {
   height: 16px;
   margin-left: 0.25em;
   vertical-align: middle;
+  cursor: pointer;
 }
 
 .objectBox-node:hover .open-inspector,

devtools/client/shared/components/reps/reps.js

@@ -5680,7 +5680,8 @@ function ElementNode(props) {
   if (isInTree) {
     if (onDOMNodeClick) {
       Object.assign(baseConfig, {
-        onClick: _ => onDOMNodeClick(object)
+        onClick: _ => onDOMNodeClick(object),
+        className: `${baseConfig.className} clickable`
       });
     }
 

devtools/server/actors/accessibility.js

@@ -503,8 +503,15 @@ const AccessibleWalkerActor = ActorClassWithSpec(accessibleWalkerSpec, {
    * A helper method. Accessibility walker is assumed to have only 1 child which
    * is the top level document.
    */
-  children() {
-    return Promise.all([this.getDocument()]);
+  async children() {
+    if (this._childrenPromise) {
+      return this._childrenPromise;
+    }
+
+    this._childrenPromise = Promise.all([this.getDocument()]);
+    let children = await this._childrenPromise;
+    this._childrenPromise = null;
+    return children;
   },
 
   /**

docshell/base/nsPingListener.cpp

@@ -162,7 +162,7 @@ SendPing(void* aClosure, nsIContent* aContent, nsIURI* aURI,
 
   if (sm && info->referrer) {
     bool referrerIsSecure;
-    uint32_t flags = nsIProtocolHandler::URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT;
+    uint32_t flags = nsIProtocolHandler::URI_IS_POTENTIALLY_TRUSTWORTHY;
     rv = NS_URIChainHasFlags(info->referrer, flags, &referrerIsSecure);
 
     // Default to sending less data if NS_URIChainHasFlags() fails.

dom/base/DocGroup.cpp

@@ -184,5 +184,17 @@ DocGroup::MoveSignalSlotListTo(nsTArray<RefPtr<HTMLSlotElement>>& aDest)
   mSignalSlotList.Clear();
 }
 
+bool
+DocGroup::IsActive() const
+{
+  for (nsIDocument* doc : mDocuments) {
+    if (doc->IsCurrentActiveDocument()) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 }
 }

dom/base/DocGroup.h

@@ -122,6 +122,9 @@ public:
   // List of DocGroups that has non-empty signal slot list.
   static AutoTArray<RefPtr<DocGroup>, 2>* sPendingDocGroups;
 
+  // Returns true if any of its documents are active but not in the bfcache.
+  bool IsActive() const;
+
 private:
   DocGroup(TabGroup* aTabGroup, const nsACString& aKey);
   ~DocGroup();

dom/base/TabGroup.cpp

@@ -306,5 +306,22 @@ TabGroup::IsBackground() const
   return mForegroundCount == 0;
 }
 
+uint32_t
+TabGroup::Count(bool aActiveOnly) const
+{
+  if (!aActiveOnly) {
+    return mDocGroups.Count();
+  }
+
+  uint32_t count = 0;
+  for (auto iter = mDocGroups.ConstIter(); !iter.Done(); iter.Next()) {
+    if (iter.Get()->mDocGroup->IsActive()) {
+      ++count;
+    }
+  }
+
+  return count;
+}
+
 } // namespace dom
 } // namespace mozilla

dom/base/TabGroup.h

@@ -100,6 +100,10 @@ public:
     return mDocGroups.Iter();
   }
 
+  // Returns the size of the set of "similar-origin" DocGroups. To
+  // only consider DocGroups with at least one active document, call
+  // Count with 'aActiveOnly' = true
+  uint32_t Count(bool aActiveOnly = false) const;
 
   // Returns the nsIDocShellTreeItem with the given name, searching each of the
   // docShell trees which are within this TabGroup. It will pass itself as

dom/base/nsContentUtils.cpp

@@ -172,7 +172,6 @@
 #include "nsIStreamConverterService.h"
 #include "nsIStringBundle.h"
 #include "nsIURI.h"
-#include "nsIURIWithPrincipal.h"
 #include "nsIURL.h"
 #include "nsIWebNavigation.h"
 #include "nsIWindowMediator.h"
@@ -3085,12 +3084,12 @@ nsContentUtils::SubjectPrincipal(JSContext* aCx)
   MOZ_ASSERT(NS_IsMainThread());
 
   // As opposed to SubjectPrincipal(), we do in fact assume that
-  // we're in a compartment here; anyone who calls this function
-  // in situations where that's not the case is doing it wrong.
-  JSCompartment* compartment = js::GetContextCompartment(aCx);
-  MOZ_ASSERT(compartment);
+  // we're in a realm here; anyone who calls this function in
+  // situations where that's not the case is doing it wrong.
+  JS::Realm* realm = js::GetContextRealm(aCx);
+  MOZ_ASSERT(realm);
 
-  JSPrincipals* principals = JS_GetCompartmentPrincipals(compartment);
+  JSPrincipals* principals = JS::GetRealmPrincipals(realm);
   return nsJSPrincipals::get(principals);
 }
 
@@ -3105,9 +3104,9 @@ nsContentUtils::SubjectPrincipal()
     MOZ_CRASH("Accessing the Subject Principal without an AutoJSAPI on the stack is forbidden");
   }
 
-  JSCompartment *compartment = js::GetContextCompartment(cx);
+  JS::Realm* realm = js::GetContextRealm(cx);
 
-  // When an AutoJSAPI is instantiated, we are in a null compartment until the
+  // When an AutoJSAPI is instantiated, we are in a null realm until the
   // first JSAutoRealm, which is kind of a purgatory as far as permissions
   // go. It would be nice to just hard-abort if somebody does a security check
   // in this purgatory zone, but that would be too fragile, since it could be
@@ -3125,9 +3124,9 @@ nsContentUtils::SubjectPrincipal()
   //
   // So we use a singleton null principal. To avoid it being accidentally
   // inherited and becoming a "real" subject or object principal, we do a
-  // release-mode assert during compartment creation against using this
-  // principal on an actual global.
-  if (!compartment) {
+  // release-mode assert during realm creation against using this principal on
+  // an actual global.
+  if (!realm) {
     return sNullSubjectPrincipal;
   }
 
@@ -6285,21 +6284,24 @@ nsContentUtils::GetASCIIOrigin(nsIURI* aURI, nsACString& aOrigin)
 {
   MOZ_ASSERT(aURI, "missing uri");
 
-  // For Blob URI we have to return the origin of page using its principal.
-  nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(aURI);
-  if (uriWithPrincipal) {
-    nsCOMPtr<nsIPrincipal> principal;
-    uriWithPrincipal->GetPrincipal(getter_AddRefs(principal));
+  bool isBlobURL = false;
+  nsresult rv = aURI->SchemeIs(BLOBURI_SCHEME, &isBlobURL);
+  NS_ENSURE_SUCCESS(rv, rv);
 
-    if (principal) {
-      nsCOMPtr<nsIURI> uri;
-      nsresult rv = principal->GetURI(getter_AddRefs(uri));
-      NS_ENSURE_SUCCESS(rv, rv);
+  // For Blob URI, the path is the URL of the owning page.
+  if (isBlobURL) {
+    nsAutoCString path;
+    rv = aURI->GetPathQueryRef(path);
+    NS_ENSURE_SUCCESS(rv, rv);
 
-      if (uri && uri != aURI) {
-        return GetASCIIOrigin(uri, aOrigin);
-      }
+    nsCOMPtr<nsIURI> uri;
+    nsresult rv = NS_NewURI(getter_AddRefs(uri), path);
+    if (NS_FAILED(rv)) {
+      aOrigin.AssignLiteral("null");
+      return NS_OK;
     }
+
+    return GetASCIIOrigin(uri, aOrigin);
   }
 
   aOrigin.Truncate();
@@ -6308,7 +6310,7 @@ nsContentUtils::GetASCIIOrigin(nsIURI* aURI, nsACString& aOrigin)
   NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);
 
   nsCString host;
-  nsresult rv = uri->GetAsciiHost(host);
+  rv = uri->GetAsciiHost(host);
 
   if (NS_SUCCEEDED(rv) && !host.IsEmpty()) {
     nsCString scheme;

dom/base/nsDocument.cpp

@@ -2364,9 +2364,9 @@ nsIDocument::ResetToURI(nsIURI* aURI,
     mFontFaceSet->RefreshStandardFontLoadPrincipal();
   }
 
-  // Refresh the principal on the compartment.
+  // Refresh the principal on the realm.
   if (nsPIDOMWindowInner* win = GetInnerWindow()) {
-    nsGlobalWindowInner::Cast(win)->RefreshCompartmentPrincipal();
+    nsGlobalWindowInner::Cast(win)->RefreshRealmPrincipal();
   }
 }
 
@@ -8495,6 +8495,18 @@ static void ClearPendingFullscreenRequests(nsIDocument* aDoc);
 void
 nsIDocument::OnPageHide(bool aPersisted, EventTarget* aDispatchStartTarget)
 {
+  if (mDocGroup && Telemetry::CanRecordExtended() &&
+      IsTopLevelContentDocument()) {
+    TabGroup* tabGroup = mDocGroup->GetTabGroup();
+
+    if (tabGroup) {
+      Telemetry::Accumulate(Telemetry::ACTIVE_DOCGROUPS_PER_TABGROUP,
+                            tabGroup->Count(true /* aActiveOnly */));
+      Telemetry::Accumulate(Telemetry::TOTAL_DOCGROUPS_PER_TABGROUP,
+                            tabGroup->Count());
+    }
+  }
+
   // Send out notifications that our <link> elements are detached,
   // but only if this is not a full unload.
   Element* root = GetRootElement();

dom/base/nsGlobalWindowInner.cpp

@@ -3632,10 +3632,10 @@ nsGlobalWindowInner::GetChildWindow(const nsAString& aName)
 }
 
 void
-nsGlobalWindowInner::RefreshCompartmentPrincipal()
+nsGlobalWindowInner::RefreshRealmPrincipal()
 {
-  JS_SetCompartmentPrincipals(js::GetObjectCompartment(GetWrapperPreserveColor()),
-                              nsJSPrincipals::get(mDoc->NodePrincipal()));
+  JS::SetRealmPrincipals(js::GetNonCCWObjectRealm(GetWrapperPreserveColor()),
+                         nsJSPrincipals::get(mDoc->NodePrincipal()));
 }
 
 already_AddRefed<nsIWidget>

dom/base/nsGlobalWindowInner.h

@@ -377,7 +377,7 @@ public:
   virtual void MaybeUpdateTouchState() override;
 
   // Inner windows only.
-  void RefreshCompartmentPrincipal();
+  void RefreshRealmPrincipal();
 
   // For accessing protected field mFullScreen
   friend class FullscreenTransitionTask;

dom/base/nsGlobalWindowOuter.cpp

@@ -1747,24 +1747,26 @@ nsGlobalWindowOuter::SetNewDocument(nsIDocument* aDocument,
     }
 
     // Inner windows are only reused for same-origin principals, but the principals
-    // don't necessarily match exactly. Update the principal on the compartment to
-    // match the new document.
-    // NB: We don't just call currentInner->RefreshCompartmentPrincipals() here
+    // don't necessarily match exactly. Update the principal on the realm to match
+    // the new document.
+    // NB: We don't just call currentInner->RefreshRealmPrincipals() here
     // because we haven't yet set its mDoc to aDocument.
-    JSCompartment *compartment = js::GetObjectCompartment(newInnerGlobal);
+    JS::Realm* realm = js::GetNonCCWObjectRealm(newInnerGlobal);
 #ifdef DEBUG
     bool sameOrigin = false;
     nsIPrincipal *existing =
-      nsJSPrincipals::get(JS_GetCompartmentPrincipals(compartment));
+      nsJSPrincipals::get(JS::GetRealmPrincipals(realm));
     aDocument->NodePrincipal()->Equals(existing, &sameOrigin);
     MOZ_ASSERT(sameOrigin);
-#endif
+
+    JSCompartment* compartment = JS::GetCompartmentForRealm(realm);
     MOZ_ASSERT_IF(aDocument == oldDoc,
                   xpc::GetCompartmentPrincipal(compartment) ==
                   aDocument->NodePrincipal());
+#endif
     if (aDocument != oldDoc) {
-      JS_SetCompartmentPrincipals(compartment,
-                                  nsJSPrincipals::get(aDocument->NodePrincipal()));
+      JS::SetRealmPrincipals(realm,
+                             nsJSPrincipals::get(aDocument->NodePrincipal()));
       // Make sure we clear out the old content XBL scope, so the new one will
       // get created with a principal that subsumes our new principal.
       xpc::ClearContentXBLScope(newInnerGlobal);
@@ -1980,13 +1982,13 @@ nsGlobalWindowOuter::SetNewDocument(nsIDocument* aDocument,
   currentInner = nullptr;
 
   // Ask the JS engine to assert that it's valid to access our DocGroup whenever
-  // it runs JS code for this compartment. We skip the check if this window is
-  // for chrome JS or an add-on.
+  // it runs JS code for this realm. We skip the check if this window is for
+  // chrome JS or an add-on.
   nsCOMPtr<nsIPrincipal> principal = mDoc->NodePrincipal();
   if (GetDocGroup() && !nsContentUtils::IsSystemPrincipal(principal) &&
       !BasePrincipal::Cast(principal)->AddonPolicy()) {
-    js::SetCompartmentValidAccessPtr(cx, newInnerGlobal,
-                                     newInnerWindow->GetDocGroup()->GetValidAccessPtr());
+    js::SetRealmValidAccessPtr(cx, newInnerGlobal,
+                               newInnerWindow->GetDocGroup()->GetValidAccessPtr());
   }
 
   kungFuDeathGrip->DidInitializeContext();

dom/base/nsJSEnvironment.cpp

@@ -2563,7 +2563,7 @@ AsmJSCacheOpenEntryForRead(JS::Handle<JSObject*> aGlobal,
                            intptr_t *aHandle)
 {
   nsIPrincipal* principal =
-    nsJSPrincipals::get(JS_GetCompartmentPrincipals(js::GetObjectCompartment(aGlobal)));
+    nsJSPrincipals::get(JS::GetRealmPrincipals(js::GetNonCCWObjectRealm(aGlobal)));
   return asmjscache::OpenEntryForRead(principal, aBegin, aLimit, aSize, aMemory,
                                       aHandle);
 }
@@ -2577,7 +2577,7 @@ AsmJSCacheOpenEntryForWrite(JS::Handle<JSObject*> aGlobal,
                             intptr_t* aHandle)
 {
   nsIPrincipal* principal =
-    nsJSPrincipals::get(JS_GetCompartmentPrincipals(js::GetObjectCompartment(aGlobal)));
+    nsJSPrincipals::get(JS::GetRealmPrincipals(js::GetNonCCWObjectRealm(aGlobal)));
   return asmjscache::OpenEntryForWrite(principal, aBegin, aEnd, aSize, aMemory,
                                        aHandle);
 }

dom/bindings/BindingUtils.cpp

@@ -2462,9 +2462,9 @@ GlobalObject::GetSubjectPrincipal() const
     return nullptr;
   }
 
-  JSCompartment* compartment = js::GetContextCompartment(mCx);
-  MOZ_ASSERT(compartment);
-  JSPrincipals* principals = JS_GetCompartmentPrincipals(compartment);
+  JS::Realm* realm = js::GetContextRealm(mCx);
+  MOZ_ASSERT(realm);
+  JSPrincipals* principals = JS::GetRealmPrincipals(realm);
   return nsJSPrincipals::get(principals);
 }
 

dom/bindings/CallbackObject.cpp

@@ -133,10 +133,10 @@ CallbackObject::CallSetup::CallSetup(CallbackObject* aCallback,
                                      ErrorResult& aRv,
                                      const char* aExecutionReason,
                                      ExceptionHandling aExceptionHandling,
-                                     JSCompartment* aCompartment,
+                                     JS::Realm* aRealm,
                                      bool aIsJSImplementedWebIDL)
   : mCx(nullptr)
-  , mCompartment(aCompartment)
+  , mRealm(aRealm)
   , mErrorResult(aRv)
   , mExceptionHandling(aExceptionHandling)
   , mIsMainThread(NS_IsMainThread())
@@ -261,35 +261,35 @@ bool
 CallbackObject::CallSetup::ShouldRethrowException(JS::Handle<JS::Value> aException)
 {
   if (mExceptionHandling == eRethrowExceptions) {
-    if (!mCompartment) {
+    if (!mRealm) {
       // Caller didn't ask us to filter for only exceptions we subsume.
       return true;
     }
 
     // On workers, we don't have nsIPrincipals to work with.  But we also only
-    // have one compartment, so check whether mCompartment is the same as the
-    // current compartment of mCx.
-    if (mCompartment == js::GetContextCompartment(mCx)) {
+    // have one realm, so check whether mRealm is the same as the current realm
+    // of mCx.
+    if (mRealm == js::GetContextRealm(mCx)) {
       return true;
     }
 
     MOZ_ASSERT(NS_IsMainThread());
 
-    // At this point mCx is in the compartment of our unwrapped callback, so
-    // just check whether the principal of mCompartment subsumes that of the
-    // current compartment/global of mCx.
+    // At this point mCx is in the realm of our unwrapped callback, so just
+    // check whether the principal of mRealm subsumes that of the current
+    // realm/global of mCx.
     nsIPrincipal* callerPrincipal =
-      nsJSPrincipals::get(JS_GetCompartmentPrincipals(mCompartment));
+      nsJSPrincipals::get(JS::GetRealmPrincipals(mRealm));
     nsIPrincipal* calleePrincipal = nsContentUtils::SubjectPrincipal();
     if (callerPrincipal->SubsumesConsideringDomain(calleePrincipal)) {
       return true;
     }
   }
 
-  MOZ_ASSERT(mCompartment);
+  MOZ_ASSERT(mRealm);
 
   // Now we only want to throw an exception to the caller if the object that was
-  // thrown is in the caller compartment (which we stored in mCompartment).
+  // thrown is in the caller realm (which we stored in mRealm).
 
   if (!aException.isObject()) {
     return false;
@@ -297,7 +297,7 @@ CallbackObject::CallSetup::ShouldRethrowException(JS::Handle<JS::Value> aExcepti
 
   JS::Rooted<JSObject*> obj(mCx, &aException.toObject());
   obj = js::UncheckedUnwrap(obj, /* stopAtWindowProxy = */ false);
-  return js::GetObjectCompartment(obj) == mCompartment;
+  return js::GetNonCCWObjectRealm(obj) == mRealm;
 }
 
 CallbackObject::CallSetup::~CallSetup()
@@ -313,7 +313,7 @@ CallbackObject::CallSetup::~CallSetup()
   // were told to re-throw them.
   if (mCx) {
     bool needToDealWithException = mAutoEntryScript->HasException();
-    if ((mCompartment && mExceptionHandling == eRethrowContentExceptions) ||
+    if ((mRealm && mExceptionHandling == eRethrowContentExceptions) ||
         mExceptionHandling == eRethrowExceptions) {
       mErrorResult.MightThrowJSException();
       if (needToDealWithException) {
@@ -349,7 +349,7 @@ CallbackObject::CallSetup::~CallSetup()
   mAutoEntryScript.reset();
 
   // It is important that this is the last thing we do, after leaving the
-  // compartment and undoing all our entry/incumbent script changes
+  // realm and undoing all our entry/incumbent script changes
   CycleCollectedJSContext* ccjs = CycleCollectedJSContext::Get();
   if (ccjs) {
     ccjs->LeaveMicroTask();

dom/bindings/CallbackObject.h

@@ -94,7 +94,7 @@ public:
   }
 
   // Like CallbackOrNull(), but will return a new dead proxy object in the
-  // caller's compartment if the callback is null.
+  // caller's realm if the callback is null.
   JSObject* Callback(JSContext* aCx);
 
   JSObject* GetCreationStack() const
@@ -146,10 +146,9 @@ public:
     // binding object for a DOMException from the caller's scope, otherwise
     // report it.
     eRethrowContentExceptions,
-    // Throw exceptions to the caller code, unless the caller compartment is
+    // Throw exceptions to the caller code, unless the caller realm is
     // provided, the exception is not a DOMException from the caller
-    // compartment, and the caller compartment does not subsume our unwrapped
-    // callback.
+    // realm, and the caller realm does not subsume our unwrapped callback.
     eRethrowExceptions
   };
 
@@ -295,17 +294,17 @@ protected:
      * non-null.
      */
   public:
-    // If aExceptionHandling == eRethrowContentExceptions then aCompartment
-    // needs to be set to the compartment in which exceptions will be rethrown.
+    // If aExceptionHandling == eRethrowContentExceptions then aRealm
+    // needs to be set to the realm in which exceptions will be rethrown.
     //
-    // If aExceptionHandling == eRethrowExceptions then aCompartment may be set
-    // to the compartment in which exceptions will be rethrown.  In that case
-    // they will only be rethrown if that compartment's principal subsumes the
+    // If aExceptionHandling == eRethrowExceptions then aRealm may be set
+    // to the realm in which exceptions will be rethrown.  In that case
+    // they will only be rethrown if that realm's principal subsumes the
     // principal of our (unwrapped) callback.
     CallSetup(CallbackObject* aCallback, ErrorResult& aRv,
               const char* aExecutionReason,
               ExceptionHandling aExceptionHandling,
-              JSCompartment* aCompartment = nullptr,
+              JS::Realm* aRealm = nullptr,
               bool aIsJSImplementedWebIDL = false);
     ~CallSetup();
 
@@ -323,9 +322,9 @@ protected:
     // Members which can go away whenever
     JSContext* mCx;
 
-    // Caller's compartment. This will only have a sensible value if
+    // Caller's realm. This will only have a sensible value if
     // mExceptionHandling == eRethrowContentExceptions or eRethrowExceptions.
-    JSCompartment* mCompartment;
+    JS::Realm* mRealm;
 
     // And now members whose construction/destruction order we need to control.
     Maybe<AutoEntryScript> mAutoEntryScript;

dom/bindings/Codegen.py

@@ -7236,9 +7236,9 @@ class CGCallGenerator(CGThing):
 
             getPrincipal = fill(
                 """
-                JSCompartment* compartment = js::GetContextCompartment(cx);
-                MOZ_ASSERT(compartment);
-                JSPrincipals* principals = JS_GetCompartmentPrincipals(compartment);
+                JS::Realm* realm = js::GetContextRealm(cx);
+                MOZ_ASSERT(realm);
+                JSPrincipals* principals = JS::GetRealmPrincipals(realm);
                 nsIPrincipal* principal = nsJSPrincipals::get(principals);
                 ${checkPrincipal}
                 """,
@@ -7563,7 +7563,7 @@ class CGPerSignatureCall(CGThing):
             if not idlNode.isStatic():
                 needsUnwrap = True
                 needsUnwrappedVar = True
-                argsPost.append("js::GetObjectCompartment(unwrappedObj ? *unwrappedObj : obj)")
+                argsPost.append("(unwrappedObj ? js::GetNonCCWObjectRealm(*unwrappedObj) : js::GetContextRealm(cx))")
         elif needScopeObject(returnType, arguments, self.extendedAttributes,
                              descriptor.wrapperCache, True,
                              idlNode.getExtendedAttribute("StoreInSlot")):
@@ -15009,7 +15009,7 @@ class CGJSImplMember(CGNativeMember):
 
     def getArgs(self, returnType, argList):
         args = CGNativeMember.getArgs(self, returnType, argList)
-        args.append(Argument("JSCompartment*", "aCompartment", "nullptr"))
+        args.append(Argument("JS::Realm*", "aRealm", "nullptr"))
         return args
 
 
@@ -15058,7 +15058,7 @@ class CGJSImplMethod(CGJSImplMember):
             assert args[-1].argType == 'JS::Handle<JSObject*>'
             assert args[-1].name == 'aGivenProto'
             constructorArgs = [arg.name for arg in args[2:-1]]
-            constructorArgs.append("js::GetObjectCompartment(scopeObj)")
+            constructorArgs.append("js::GetNonCCWObjectRealm(scopeObj)")
             initCall = fill(
                 """
                 // Wrap the object before calling __Init so that __DOM_IMPL__ is available.
@@ -15506,9 +15506,9 @@ class CGCallback(CGClass):
                              "nullptr"))
 
         # Make copies of the arg list for the two "without rv" overloads.  Note
-        # that those don't need aExceptionHandling or aCompartment arguments
-        # because those would make not sense anyway: the only sane thing to do
-        # with exceptions in the "without rv" cases is to report them.
+        # that those don't need aExceptionHandling or aRealm arguments because
+        # those would make not sense anyway: the only sane thing to do with
+        # exceptions in the "without rv" cases is to report them.
         argsWithoutRv = list(args)
         argsWithoutRv.pop(rvIndex)
         argsWithoutThisAndRv = list(argsWithoutRv)
@@ -15519,10 +15519,10 @@ class CGCallback(CGClass):
                              "eReportExceptions"))
         # And the argument for communicating when exceptions should really be
         # rethrown.  In particular, even when aExceptionHandling is
-        # eRethrowExceptions they won't get rethrown if aCompartment is provided
+        # eRethrowExceptions they won't get rethrown if aRealm is provided
         # and its principal doesn't subsume either the callback or the
         # exception.
-        args.append(Argument("JSCompartment*", "aCompartment", "nullptr"))
+        args.append(Argument("JS::Realm*", "aRealm", "nullptr"))
         # And now insert our template argument.
         argsWithoutThis = list(args)
         args.insert(0, Argument("const T&",  "thisVal"))
@@ -15533,8 +15533,8 @@ class CGCallback(CGClass):
         # If we just leave things like that, and have no actual arguments in the
         # IDL, we will end up trying to call the templated "without rv" overload
         # with "rv" as the thisVal.  That's no good.  So explicitly append the
-        # aExceptionHandling and aCompartment values we need to end up matching
-        # the signature of our non-templated "with rv" overload.
+        # aExceptionHandling and aRealm values we need to end up matching the
+        # signature of our non-templated "with rv" overload.
         argnamesWithoutThisAndRv.extend(["eReportExceptions", "nullptr"])
 
         argnamesWithoutRv = [arg.name for arg in argsWithoutRv]
@@ -15550,7 +15550,7 @@ class CGCallback(CGClass):
             if (!aExecutionReason) {
               aExecutionReason = "${executionReason}";
             }
-            CallSetup s(this, aRv, aExecutionReason, aExceptionHandling, aCompartment);
+            CallSetup s(this, aRv, aExecutionReason, aExceptionHandling, aRealm);
             if (!s.GetContext()) {
               MOZ_ASSERT(aRv.Failed());
               return${errorReturn};
@@ -15961,7 +15961,7 @@ class CallbackMember(CGNativeMember):
                                      "nullptr"))
                 args.append(Argument("ExceptionHandling", "aExceptionHandling",
                                      "eReportExceptions"))
-            args.append(Argument("JSCompartment*", "aCompartment", "nullptr"))
+            args.append(Argument("JS::Realm*", "aRealm", "nullptr"))
             return args
         # We want to allow the caller to pass in a "this" value, as
         # well as a JSContext.
@@ -15975,11 +15975,11 @@ class CallbackMember(CGNativeMember):
         callSetup = "CallSetup s(this, aRv"
         if self.rethrowContentException:
             # getArgs doesn't add the aExceptionHandling argument but does add
-            # aCompartment for us.
-            callSetup += ', "%s", eRethrowContentExceptions, aCompartment, /* aIsJSImplementedWebIDL = */ ' % self.getPrettyName()
+            # aRealm for us.
+            callSetup += ', "%s", eRethrowContentExceptions, aRealm, /* aIsJSImplementedWebIDL = */ ' % self.getPrettyName()
             callSetup += toStringBool(isJSImplementedDescriptor(self.descriptorProvider))
         else:
-            callSetup += ', "%s", aExceptionHandling, aCompartment' % self.getPrettyName()
+            callSetup += ', "%s", aExceptionHandling, aRealm' % self.getPrettyName()
         callSetup += ");\n"
         return fill(
             """

dom/bindings/Exceptions.cpp

@@ -189,7 +189,7 @@ GetCurrentJSStack(int32_t aMaxDepth)
   // is there a current context available?
   JSContext* cx = nsContentUtils::GetCurrentJSContext();
 
-  if (!cx || !js::GetContextCompartment(cx)) {
+  if (!cx || !js::GetContextRealm(cx)) {
     return nullptr;
   }
 

dom/bindings/test/mochitest.ini

@@ -73,6 +73,8 @@ skip-if = debug == false
 skip-if = debug == false
 [test_jsimplemented_eventhandler.html]
 skip-if = debug == false
+[test_jsimplemented_cross_realm_this.html]
+skip-if = debug == false
 [test_iterable.html]
 skip-if = debug == false
 [test_oom_reporting.html]

dom/bindings/test/test_jsimplemented_cross_realm_this.html

@@ -0,0 +1,43 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1464374-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1464374</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1464374">Mozilla Bug 1464374</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+</pre>
+
+<iframe></iframe>
+<script type="application/javascript">
+  /** Test for Bug 1464374 **/
+  SimpleTest.waitForExplicitFinish();
+
+  function doTest() {
+    var frame = frames[0];
+    var obj = new frame.TestInterfaceJS();
+    var ex;
+    try {
+      TestInterfaceJS.prototype.testThrowTypeError.call(obj);
+    } catch(e) {
+      ex = e;
+    }
+    ok(ex, "Should have an exception");
+    SimpleTest.finish();
+  }
+
+  SpecialPowers.pushPrefEnv({set: [['dom.expose_test_interfaces', true]]},
+                            doTest);
+</script>
+
+</body>
+</html>

dom/html/nsHTMLDocument.cpp

@@ -1537,10 +1537,10 @@ nsHTMLDocument::Open(JSContext* cx,
   SetReadyStateInternal(nsIDocument::READYSTATE_LOADING);
 
   // After changing everything around, make sure that the principal on the
-  // document's compartment exactly matches NodePrincipal().
+  // document's realm exactly matches NodePrincipal().
   DebugOnly<JSObject*> wrapper = GetWrapperPreserveColor();
   MOZ_ASSERT_IF(wrapper,
-                JS_GetCompartmentPrincipals(js::GetObjectCompartment(wrapper)) ==
+                JS::GetRealmPrincipals(js::GetNonCCWObjectRealm(wrapper)) ==
                 nsJSPrincipals::get(NodePrincipal()));
 
   return kungFuDeathGrip.forget();

dom/script/ScriptSettings.cpp

@@ -618,7 +618,7 @@ AutoJSAPI::PeekException(JS::MutableHandle<JS::Value> aVal)
 {
   MOZ_ASSERT_IF(mIsMainThread, IsStackTop());
   MOZ_ASSERT(HasException());
-  MOZ_ASSERT(js::GetContextCompartment(cx()));
+  MOZ_ASSERT(js::GetContextRealm(cx()));
   if (!JS_GetPendingException(cx(), aVal)) {
     return false;
   }

dom/security/nsContentSecurityManager.cpp

@@ -890,12 +890,16 @@ nsContentSecurityManager::IsOriginPotentiallyTrustworthy(nsIPrincipal* aPrincipa
   // which is technically a substituting protocol handler that is not limited to
   // local resource mapping, but in practice is never mapped remotely as this
   // would violate assumptions a lot of code makes.
-  if (scheme.EqualsLiteral("https") ||
-      scheme.EqualsLiteral("file") ||
-      scheme.EqualsLiteral("resource") ||
-      scheme.EqualsLiteral("app") ||
-      scheme.EqualsLiteral("moz-extension") ||
-      scheme.EqualsLiteral("wss")) {
+  // We use nsIProtocolHandler flags to determine which protocols we consider a priori
+  // authenticated.
+  bool aPrioriAuthenticated = false;
+  if (NS_FAILED(NS_URIChainHasFlags(uri,
+                                    nsIProtocolHandler::URI_IS_POTENTIALLY_TRUSTWORTHY,
+                                    &aPrioriAuthenticated))) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  if (aPrioriAuthenticated) {
     *aIsTrustWorthy = true;
     return NS_OK;
   }

dom/security/nsMixedContentBlocker.cpp

@@ -597,7 +597,7 @@ nsMixedContentBlocker::ShouldLoad(bool aHadInsecureImageRedirect,
   *   "moz-icon"
   * URI_INHERITS_SECURITY_CONTEXT - e.g.
   *   "javascript"
-  * URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT - e.g.
+  * URI_IS_POTENTIALLY_TRUSTWORTHY - e.g.
   *   "https",
   *   "moz-safe-about"
   *
@@ -609,7 +609,7 @@ nsMixedContentBlocker::ShouldLoad(bool aHadInsecureImageRedirect,
   if (NS_FAILED(NS_URIChainHasFlags(innerContentLocation, nsIProtocolHandler::URI_IS_LOCAL_RESOURCE , &schemeLocal))  ||
       NS_FAILED(NS_URIChainHasFlags(innerContentLocation, nsIProtocolHandler::URI_DOES_NOT_RETURN_DATA, &schemeNoReturnData)) ||
       NS_FAILED(NS_URIChainHasFlags(innerContentLocation, nsIProtocolHandler::URI_INHERITS_SECURITY_CONTEXT, &schemeInherits)) ||
-      NS_FAILED(NS_URIChainHasFlags(innerContentLocation, nsIProtocolHandler::URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT, &schemeSecure))) {
+      NS_FAILED(NS_URIChainHasFlags(innerContentLocation, nsIProtocolHandler::URI_IS_POTENTIALLY_TRUSTWORTHY, &schemeSecure))) {
     *aDecision = REJECT_REQUEST;
     return NS_ERROR_FAILURE;
   }

dom/security/test/gtest/TestSecureContext.cpp

@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#include "gtest/gtest.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "nsContentSecurityManager.h"
+#include "nsContentUtils.h"
+#include "nsIPrincipal.h"
+#include "nsScriptSecurityManager.h"
+#include "NullPrincipal.h"
+
+static const uint32_t kURIMaxLength = 64;
+
+struct TestExpectations {
+  char uri[kURIMaxLength ];
+  bool expectedResult;
+};
+
+// ============================= TestDirectives ========================
+
+TEST(SecureContext, IsOriginPotentiallyTrustworthyWithCodeBasePrincipal)
+{
+  //boolean isOriginPotentiallyTrustworthy(in nsIPrincipal aPrincipal);
+
+  static const TestExpectations uris[] = {
+    { "http://example.com/", false },
+    { "https://example.com/", true },
+    { "ws://example.com/", false },
+    { "wss://example.com/", true },
+    { "file:///xyzzy", true },
+    { "ftp://example.com", false },
+    { "about:config", false },
+    { "http://localhost", true },
+    { "http://xyzzy.localhost", false },
+    { "http://127.0.0.1", true },
+    { "resource://xyzzy", true },
+    { "moz-extension://xyzzy", true },
+    { "data:data:text/plain;charset=utf-8;base64,eHl6enk=", false },
+    { "blob://unique-id", false },
+    { "mailto:foo@bar.com", false },
+    { "moz-icon://example.com", false },
+    { "javascript:42", false },
+  };
+
+  uint32_t numExpectations = sizeof(uris) / sizeof(TestExpectations);
+  nsCOMPtr<nsIContentSecurityManager> csManager = do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
+  ASSERT_TRUE(!!csManager);
+
+  nsresult rv;
+  for (uint32_t i = 0; i < numExpectations; i++) {
+    nsCOMPtr<nsIPrincipal> prin;
+    nsAutoCString uri(uris[i].uri);
+    rv = nsScriptSecurityManager::GetScriptSecurityManager()->
+           CreateCodebasePrincipalFromOrigin(uri, getter_AddRefs(prin));
+    bool isPotentiallyTrustworthy = false;
+    rv = csManager->IsOriginPotentiallyTrustworthy(prin, &isPotentiallyTrustworthy);
+    ASSERT_EQ(NS_OK, rv);
+    ASSERT_EQ(isPotentiallyTrustworthy, uris[i].expectedResult);
+  }
+}
+
+TEST(SecureContext, IsOriginPotentiallyTrustworthyWithSystemPrincipal)
+{
+  RefPtr<nsScriptSecurityManager> ssManager = nsScriptSecurityManager::GetScriptSecurityManager();
+  ASSERT_TRUE(!!ssManager);
+  nsCOMPtr<nsIContentSecurityManager> csManager = do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
+  ASSERT_TRUE(!!csManager);
+
+  nsCOMPtr<nsIPrincipal> sysPrin = nsContentUtils::GetSystemPrincipal();
+  bool isPotentiallyTrustworthy;
+  nsresult rv = csManager->IsOriginPotentiallyTrustworthy(sysPrin, &isPotentiallyTrustworthy);
+  ASSERT_EQ(rv, NS_OK);
+  ASSERT_TRUE(isPotentiallyTrustworthy);
+}
+
+TEST(SecureContext, IsOriginPotentiallyTrustworthyWithNullPrincipal)
+{
+  RefPtr<nsScriptSecurityManager> ssManager = nsScriptSecurityManager::GetScriptSecurityManager();
+  ASSERT_TRUE(!!ssManager);
+  nsCOMPtr<nsIContentSecurityManager> csManager = do_GetService(NS_CONTENTSECURITYMANAGER_CONTRACTID);
+  ASSERT_TRUE(!!csManager);
+
+  RefPtr<NullPrincipal> nullPrin = NullPrincipal::CreateWithoutOriginAttributes();
+  bool isPotentiallyTrustworthy;
+  nsresult rv = csManager->IsOriginPotentiallyTrustworthy(nullPrin, &isPotentiallyTrustworthy);
+  ASSERT_EQ(rv, NS_OK);
+  ASSERT_TRUE(!isPotentiallyTrustworthy);
+}

dom/security/test/gtest/moz.build

@@ -6,6 +6,11 @@
 
 UNIFIED_SOURCES += [
      'TestCSPParser.cpp',
+     'TestSecureContext.cpp',
 ]
 
 FINAL_LIBRARY = 'xul-gtest'
+
+LOCAL_INCLUDES += [
+    '/caps',
+]

dom/tests/mochitest/chrome/chrome.ini

@@ -46,12 +46,10 @@ tags = fullscreen
 [test_bug830858.xul]
 [test_bug1224790-1.xul]
 tags = openwindow
-# synthesizeNativeOSXClick does not work on 10.6
-skip-if = os != 'mac' || os_version == '10.6'
+skip-if = os != 'mac'
 [test_bug1224790-2.xul]
 tags = openwindow
-# synthesizeNativeOSXClick does not work on 10.6
-skip-if = os != 'mac' || os_version == '10.6'
+skip-if = os != 'mac'
 [test_callback_wrapping.xul]
 [test_clonewrapper.xul]
 [test_cyclecollector.xul]

dom/workers/WorkerPrivate.cpp

@@ -1206,15 +1206,12 @@ public:
     // aRealmStats->extra is a xpc::RealmStatsExtras pointer.
     xpc::RealmStatsExtras* extras = new xpc::RealmStatsExtras;
 
-    // This is the |jsPathPrefix|.  Each worker has exactly two realms:
-    // one for atoms, and one for everything else.
+    // This is the |jsPathPrefix|.  Each worker has exactly one realm.
     JSCompartment* compartment = JS::GetCompartmentForRealm(aRealm);
     extras->jsPathPrefix.Assign(mRtPath);
     extras->jsPathPrefix += nsPrintfCString("zone(0x%p)/",
                                             (void *)js::GetCompartmentZone(compartment));
-    extras->jsPathPrefix += js::IsAtomsRealm(aRealm)
-                            ? NS_LITERAL_CSTRING("realm(web-worker-atoms)/")
-                            : NS_LITERAL_CSTRING("realm(web-worker)/");
+    extras->jsPathPrefix += NS_LITERAL_CSTRING("realm(web-worker)/");
 
     // This should never be used when reporting with workers (hence the "?!").
     extras->domPathPrefix.AssignLiteral("explicit/workers/?!/");

gfx/config/gfxVars.h

@@ -39,9 +39,11 @@ class gfxVarReceiver;
   _(UseWebRenderANGLE,          bool,             false)                \
   _(UseWebRenderDCompWin,       bool,             false)                \
   _(UseWebRenderProgramBinary,  bool,             false)                \
+  _(UseWebRenderProgramBinaryDisk, bool,          false)                \
   _(WebRenderDebugFlags,        int32_t,          0)                    \
   _(ScreenDepth,                int32_t,          0)                    \
   _(GREDirectory,               nsString,         nsString())           \
+  _(ProfDirectory,              nsString,         nsString())           \
   _(UseOMTP,                    bool,             false)                \
   _(AllowD3D11KeyedMutex,       bool,             false)                \
 

gfx/layers/client/MultiTiledContentClient.cpp

@@ -326,7 +326,6 @@ void ClientMultiTiledLayerBuffer::Update(const nsIntRegion& newValidRegion,
     }
 
     bool edgePaddingEnabled = gfxPrefs::TileEdgePaddingEnabled();
-
     for (uint32_t i = 0; i < mRetainedTiles.Length(); ++i) {
       TileClient& tile = mRetainedTiles[i];
 
@@ -442,6 +441,8 @@ ClientMultiTiledLayerBuffer::ValidateTile(TileClient& aTile,
     return false;
   }
 
+  // Get the targets to draw into, and create a dual target
+  // if we are using component alpha
   RefPtr<DrawTarget> dt = backBuffer->BorrowDrawTarget();
   RefPtr<DrawTarget> dtOnWhite;
   if (backBufferOnWhite) {
@@ -460,12 +461,18 @@ ClientMultiTiledLayerBuffer::ValidateTile(TileClient& aTile,
     drawTarget = dt;
   }
 
-  auto clear = CapturedTiledPaintState::Clear{
-    dt,
-    dtOnWhite,
-    tileDirtyRegion
-  };
+  // We need to clear the dirty region of the tile before painting
+  // if we are painting non-opaque content
+  Maybe<CapturedTiledPaintState::Clear> clear = Nothing();
+  if (mode != SurfaceMode::SURFACE_OPAQUE) {
+    clear = Some(CapturedTiledPaintState::Clear{
+      dt,
+      dtOnWhite,
+      tileDirtyRegion
+    });
+  }
 
+  // Queue or execute the paint operation
   gfx::Tile paintTile;
   paintTile.mTileOrigin = gfx::IntPoint(aTileOrigin.x, aTileOrigin.y);
 
@@ -481,7 +488,9 @@ ClientMultiTiledLayerBuffer::ValidateTile(TileClient& aTile,
     asyncPaint->mCapture = captureDT;
 
     asyncPaint->mCopies = std::move(asyncPaintCopies);
-    asyncPaint->mClears.push_back(clear);
+    if (clear) {
+      asyncPaint->mClears.push_back(*clear);
+    }
 
     asyncPaint->mClients = std::move(asyncPaintClients);
     asyncPaint->mClients.push_back(backBuffer);
@@ -492,7 +501,9 @@ ClientMultiTiledLayerBuffer::ValidateTile(TileClient& aTile,
     mPaintStates.push_back(asyncPaint);
   } else {
     paintTile.mDrawTarget = drawTarget;
-    clear.ClearBuffer();
+    if (clear) {
+      clear->ClearBuffer();
+    }
   }
 
   mPaintTiles.push_back(paintTile);

gfx/layers/client/SingleTiledContentClient.cpp

@@ -197,68 +197,21 @@ ClientSingleTiledLayerBuffer::PaintThebes(const nsIntRegion& aNewValidRegion,
     copyableRegion.And(aNewValidRegion, discardedValidRegion);
     copyableRegion.SubOut(aDirtyRegion);
 
-    if (!copyableRegion.IsEmpty()) {
-      OpenMode asyncFlags = asyncPaint ? OpenMode::OPEN_ASYNC
-                                       : OpenMode::OPEN_NONE;
+    if (!mTile.CopyFromBuffer(discardedFrontBuffer,
+                              discardedFrontBufferOnWhite,
+                              discardedValidRegion.GetBounds().TopLeft(),
+                              mTilingOrigin,
+                              copyableRegion,
+                              aFlags,
+                              &paintCopies)) {
+      gfxWarning() << "[Tiling:Client] Failed to aquire the discarded front buffer's draw target";
+    } else {
+      TILING_LOG("TILING %p: Region copied from discarded frontbuffer %s\n", &mPaintedLayer, Stringify(copyableRegion).c_str());
 
-      TextureClientAutoLock frontLock(discardedFrontBuffer,
-                                      OpenMode::OPEN_READ | asyncFlags);
-      Maybe<TextureClientAutoLock> frontOnWhiteLock;
-      if (discardedFrontBufferOnWhite && backBufferOnWhite) {
-        frontOnWhiteLock.emplace(discardedFrontBufferOnWhite, OpenMode::OPEN_READ | asyncFlags);
-      }
-
-      // Copy to both backBuffer and backBufferOnWhite if required, or copy to neither.
-      if (frontLock.Succeeded() && (!frontOnWhiteLock || frontOnWhiteLock->Succeeded())) {
-        RefPtr<gfx::DrawTarget> frontBuffer = discardedFrontBuffer->BorrowDrawTarget();
-
-        if (frontBuffer) {
-          for (auto iter = copyableRegion.RectIter(); !iter.Done(); iter.Next()) {
-            const gfx::IntRect rect = iter.Get() - discardedValidRegion.GetBounds().TopLeft();
-            const gfx::IntPoint dest = iter.Get().TopLeft() - mTilingOrigin;
-
-            auto copy = CapturedTiledPaintState::Copy{
-              frontBuffer, dt, rect, dest
-            };
-            if (asyncPaint) {
-              paintCopies.push_back(copy);
-            } else {
-              copy.CopyBuffer();
-            }
-          }
-
-          if (frontOnWhiteLock) {
-            RefPtr<gfx::DrawTarget> frontBufferOnWhite = discardedFrontBufferOnWhite->BorrowDrawTarget();
-
-            if (frontBufferOnWhite) {
-              for (auto iter = copyableRegion.RectIter(); !iter.Done(); iter.Next()) {
-                const gfx::IntRect rect = iter.Get() - discardedValidRegion.GetBounds().TopLeft();
-                const gfx::IntPoint dest = iter.Get().TopLeft() - mTilingOrigin;
-
-                auto copy = CapturedTiledPaintState::Copy{
-                  frontBufferOnWhite, dtOnWhite, rect, dest
-                };
-                if (asyncPaint) {
-                  paintCopies.push_back(copy);
-                } else {
-                  copy.CopyBuffer();
-                }
-              }
-            } else {
-              gfxWarning() << "[Tiling:Client] Failed to aquire the discarded front buffer's draw target";
-            }
-          }
-        } else {
-          gfxWarning() << "[Tiling:Client] Failed to aquire the discarded front buffer's draw target";
-        }
-
-        TILING_LOG("TILING %p: Region copied from discarded frontbuffer %s\n", &mPaintedLayer, Stringify(copyableRegion).c_str());
-
-        // We don't need to repaint valid content that was just copied.
-        paintRegion.SubOut(copyableRegion);
-        copyableRegion.MoveBy(-mTilingOrigin);
-        tileDirtyRegion.SubOut(copyableRegion);
-      }
+      // We don't need to repaint valid content that was just copied.
+      paintRegion.SubOut(copyableRegion);
+      copyableRegion.MoveBy(-mTilingOrigin);
+      tileDirtyRegion.SubOut(copyableRegion);
     }
   }
 

gfx/layers/client/TiledContentClient.cpp

@@ -483,45 +483,49 @@ TileClient::ValidateBackBufferFromFront(const nsIntRegion& aDirtyRegion,
                                         std::vector<CapturedTiledPaintState::Copy>* aCopies,
                                         std::vector<RefPtr<TextureClient>>* aClients)
 {
-  if (mBackBuffer && mFrontBuffer) {
-    gfx::IntSize tileSize = mFrontBuffer->GetSize();
-    const IntRect tileRect = IntRect(0, 0, tileSize.width, tileSize.height);
+  if (!mBackBuffer || !mFrontBuffer) {
+    return;
+  }
 
-    if (aDirtyRegion.Contains(tileRect)) {
-      // The dirty region means that we no longer need the front buffer, so
-      // discard it.
-      DiscardFrontBuffer();
-    } else {
-      // Region that needs copying.
-      nsIntRegion regionToCopy = mInvalidBack;
+  gfx::IntSize tileSize = mFrontBuffer->GetSize();
+  const IntRect tileRect = IntRect(0, 0, tileSize.width, tileSize.height);
 
-      regionToCopy.Sub(regionToCopy, aDirtyRegion);
-      regionToCopy.And(regionToCopy, aVisibleRegion);
+  if (aDirtyRegion.Contains(tileRect)) {
+    // The dirty region means that we no longer need the front buffer, so
+    // discard it.
+    DiscardFrontBuffer();
+    return;
+  }
 
-      aAddPaintedRegion = regionToCopy;
+  // Region that needs copying.
+  nsIntRegion regionToCopy = mInvalidBack;
 
-      if (regionToCopy.IsEmpty()) {
-        // Just redraw it all.
-        return;
-      }
+  regionToCopy.Sub(regionToCopy, aDirtyRegion);
+  regionToCopy.And(regionToCopy, aVisibleRegion);
 
-      // Copy the bounding rect of regionToCopy. As tiles are quite small, it
-      // is unlikely that we'd save much by copying each individual rect of the
-      // region, but we can reevaluate this if it becomes an issue.
-      const IntRect rectToCopy = regionToCopy.GetBounds();
-      gfx::IntRect gfxRectToCopy(rectToCopy.X(), rectToCopy.Y(), rectToCopy.Width(), rectToCopy.Height());
-      if (CopyFrontToBack(mFrontBuffer, mBackBuffer, gfxRectToCopy, aFlags, aCopies, aClients)) {
-        if (mBackBufferOnWhite) {
-          MOZ_ASSERT(mFrontBufferOnWhite);
-          if (CopyFrontToBack(mFrontBufferOnWhite, mBackBufferOnWhite, gfxRectToCopy, aFlags, aCopies, aClients)) {
-            mInvalidBack.Sub(mInvalidBack, aVisibleRegion);
-          }
-        } else {
-          mInvalidBack.Sub(mInvalidBack, aVisibleRegion);
-        }
-      }
+  aAddPaintedRegion = regionToCopy;
+
+  if (regionToCopy.IsEmpty()) {
+    // Just redraw it all.
+    return;
+  }
+
+  // Copy the bounding rect of regionToCopy. As tiles are quite small, it
+  // is unlikely that we'd save much by copying each individual rect of the
+  // region, but we can reevaluate this if it becomes an issue.
+  const IntRect rectToCopy = regionToCopy.GetBounds();
+  if (!CopyFrontToBack(mFrontBuffer, mBackBuffer, rectToCopy, aFlags, aCopies, aClients)) {
+    return;
+  }
+
+  if (mBackBufferOnWhite) {
+    MOZ_ASSERT(mFrontBufferOnWhite);
+    if (!CopyFrontToBack(mFrontBufferOnWhite, mBackBufferOnWhite, rectToCopy, aFlags, aCopies, aClients)) {
+      return;
     }
   }
+
+  mInvalidBack.Sub(mInvalidBack, aVisibleRegion);
 }
 
 void
@@ -580,6 +584,59 @@ TileClient::DiscardBackBuffer()
   }
 }
 
+bool
+TileClient::CopyFromBuffer(RefPtr<TextureClient> aBuffer,
+                           RefPtr<TextureClient> aBufferOnWhite,
+                           nsIntPoint aBufferOrigin,
+                           nsIntPoint aTileOrigin,
+                           const nsIntRegion& aRegion,
+                           TilePaintFlags aFlags,
+                           std::vector<CapturedTiledPaintState::Copy>* aCopies)
+{
+  if (aRegion.IsEmpty()) {
+    return true;
+  }
+
+  bool asyncPaint = !!(aFlags & TilePaintFlags::Async);
+  auto CopyBuffer = [&aRegion, asyncPaint, &aCopies] (auto aSrc, auto aSrcOrigin, auto aDest, auto aDestOrigin) {
+    MOZ_ASSERT(aDest->IsLocked());
+
+    OpenMode asyncFlags = asyncPaint ? OpenMode::OPEN_ASYNC
+                                     : OpenMode::OPEN_NONE;
+    TextureClientAutoLock lock(aSrc, OpenMode::OPEN_READ | asyncFlags);
+    if (!lock.Succeeded()) {
+      return false;
+    }
+
+    RefPtr<gfx::DrawTarget> srcTarget = aSrc->BorrowDrawTarget();
+    RefPtr<gfx::DrawTarget> destTarget = aDest->BorrowDrawTarget();
+    if (!srcTarget || !destTarget) {
+      return false;
+    }
+
+    for (auto iter = aRegion.RectIter(); !iter.Done(); iter.Next()) {
+      const gfx::IntRect src = iter.Get() - aSrcOrigin;
+      const gfx::IntPoint dest = iter.Get().TopLeft() - aDestOrigin;
+
+      auto copy = CapturedTiledPaintState::Copy{
+        srcTarget, destTarget, src, dest
+      };
+
+      if (asyncPaint) {
+        aCopies->push_back(copy);
+      } else {
+        copy.CopyBuffer();
+      }
+    }
+    return true;
+  };
+
+  return CopyBuffer(aBuffer, aBufferOrigin, mBackBuffer, aTileOrigin) &&
+    (!aBufferOnWhite ||
+     !mBackBufferOnWhite ||
+     CopyBuffer(aBufferOnWhite, aBufferOrigin, mBackBufferOnWhite, aTileOrigin));
+}
+
 static already_AddRefed<TextureClient>
 CreateBackBufferTexture(TextureClient* aCurrentTexture,
                         CompositableClient& aCompositable,

gfx/layers/client/TiledContentClient.h

@@ -140,6 +140,18 @@ struct TileClient
 
   void DiscardBackBuffer();
 
+  /*
+   * Copy aRegion from aBuffer and aBufferOnWhite positioned at aBufferOrigin
+   * into ourselves assuming we are positioned at aTileOrigin.
+   */
+  bool CopyFromBuffer(RefPtr<TextureClient> aBuffer,
+                      RefPtr<TextureClient> aBufferOnWhite,
+                      nsIntPoint aBufferOrigin,
+                      nsIntPoint aTileOrigin,
+                      const nsIntRegion& aRegion,
+                      TilePaintFlags aFlags,
+                      std::vector<CapturedTiledPaintState::Copy>* aCopies);
+
   /* We wrap the back buffer in a class that disallows assignment
    * so that we can track when ever it changes so that we can update
    * the expiry tracker for expiring the back buffers */
@@ -168,8 +180,10 @@ struct TileClient
   nsIntRegion mInvalidBack;
   nsExpirationState mExpirationState;
 private:
-  // Copies dirty pixels from the front buffer into the back buffer,
-  // and records the copied region in aAddPaintedRegion.
+  /*
+   * Copies dirty pixels from the front buffer into the back buffer,
+   * and records the copied region in aAddPaintedRegion.
+   */
   void ValidateBackBufferFromFront(const nsIntRegion &aDirtyRegion,
                                    const nsIntRegion& aVisibleRegion,
                                    nsIntRegion& aAddPaintedRegion,

gfx/thebes/gfxPlatform.cpp

@@ -22,6 +22,7 @@
 
 #include "mozilla/Logging.h"
 #include "mozilla/Services.h"
+#include "nsAppDirectoryServiceDefs.h"
 
 #include "gfxCrashReporterUtils.h"
 #include "gfxPlatform.h"
@@ -866,6 +867,18 @@ gfxPlatform::Init()
         Preferences::SetBool(FONT_VARIATIONS_PREF, false);
         Preferences::Lock(FONT_VARIATIONS_PREF);
       }
+
+      nsCOMPtr<nsIFile> profDir;
+      rv = NS_GetSpecialDirectory(NS_APP_PROFILE_DIR_STARTUP, getter_AddRefs(profDir));
+      if (NS_FAILED(rv)) {
+        gfxVars::SetProfDirectory(nsString());
+      } else {
+        nsAutoString path;
+        profDir->GetPath(path);
+        gfxVars::SetProfDirectory(nsString(path));
+      }
+
+      gfxUtils::RemoveShaderCacheFromDiskIfNecessary();
     }
 
     if (obs) {
@@ -2626,7 +2639,10 @@ gfxPlatform::InitWebRenderConfig()
 #endif
 
   if (Preferences::GetBool("gfx.webrender.program-binary", false)) {
-    gfx::gfxVars::SetUseWebRenderProgramBinary(gfxConfig::IsEnabled(Feature::WEBRENDER));
+    gfxVars::SetUseWebRenderProgramBinary(gfxConfig::IsEnabled(Feature::WEBRENDER));
+    if (Preferences::GetBool("gfx.webrender.program-binary-disk", false)) {
+      gfxVars::SetUseWebRenderProgramBinaryDisk(gfxConfig::IsEnabled(Feature::WEBRENDER));
+    }
   }
 
 #ifdef MOZ_WIDGET_ANDROID

gfx/thebes/gfxUtils.cpp

@@ -22,11 +22,14 @@
 #include "mozilla/gfx/Logging.h"
 #include "mozilla/gfx/PathHelpers.h"
 #include "mozilla/gfx/Swizzle.h"
+#include "mozilla/gfx/gfxVars.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/UniquePtrExtensions.h"
 #include "mozilla/Unused.h"
 #include "mozilla/Vector.h"
+#include "mozilla/webrender/webrender_ffi.h"
+#include "nsAppRunner.h"
 #include "nsComponentManagerUtils.h"
 #include "nsIClipboardHelper.h"
 #include "nsIFile.h"
@@ -1468,6 +1471,54 @@ gfxUtils::ThreadSafeGetFeatureStatus(const nsCOMPtr<nsIGfxInfo>& gfxInfo,
   return gfxInfo->GetFeatureStatus(feature, failureId, status);
 }
 
+#define GFX_SHADER_CHECK_BUILD_VERSION_PREF "gfx-shader-check.build-version"
+#define GFX_SHADER_CHECK_DEVICE_ID_PREF "gfx-shader-check.device-id"
+#define GFX_SHADER_CHECK_DRIVER_VERSION_PREF "gfx-shader-check.driver-version"
+
+/* static */ void
+gfxUtils::RemoveShaderCacheFromDiskIfNecessary()
+{
+  if (!gfxVars::UseWebRenderProgramBinaryDisk()) {
+    return;
+  }
+
+  nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
+
+  // Get current values
+  nsCString buildID(mozilla::PlatformBuildID());
+  nsString deviceID, driverVersion;
+  gfxInfo->GetAdapterDeviceID(deviceID);
+  gfxInfo->GetAdapterDriverVersion(driverVersion);
+
+  // Get pref stored values
+  nsAutoCString buildIDChecked;
+  Preferences::GetCString(GFX_SHADER_CHECK_BUILD_VERSION_PREF, buildIDChecked);
+  nsAutoString deviceIDChecked, driverVersionChecked;
+  Preferences::GetString(GFX_SHADER_CHECK_DEVICE_ID_PREF, deviceIDChecked);
+  Preferences::GetString(GFX_SHADER_CHECK_DRIVER_VERSION_PREF, driverVersionChecked);
+
+  if (buildID == buildIDChecked &&
+      deviceID == deviceIDChecked &&
+      driverVersion == driverVersionChecked) {
+      return;
+  }
+
+  nsAutoString path(gfx::gfxVars::ProfDirectory());
+
+  if (!wr::remove_program_binary_disk_cache(&path)) {
+    // Failed to remove program binary disk cache. The disk cache might have
+    // invalid data. Disable program binary disk cache usage.
+    gfxVars::SetUseWebRenderProgramBinaryDisk(false);
+    return;
+  }
+
+  Preferences::SetCString(GFX_SHADER_CHECK_BUILD_VERSION_PREF, buildID);
+  Preferences::SetString(GFX_SHADER_CHECK_DEVICE_ID_PREF, deviceID);
+  Preferences::SetString(GFX_SHADER_CHECK_DRIVER_VERSION_PREF, driverVersion);
+  return;
+}
+
+
 /* static */ bool
 gfxUtils::DumpDisplayList() {
   return gfxPrefs::LayoutDumpDisplayList() ||

gfx/thebes/gfxUtils.h

@@ -295,6 +295,8 @@ public:
                                                nsACString& failureId,
                                                int32_t* status);
 
+    static void RemoveShaderCacheFromDiskIfNecessary();
+
     /**
      * Copy to the clipboard as a PNG encoded Data URL.
      */

gfx/webrender_bindings/Cargo.toml

@@ -11,12 +11,16 @@ euclid = { version = "0.17", features = ["serde"] }
 app_units = "0.6"
 gleam = "0.5"
 log = "0.4"
+nsstring = { path = "../../servo/support/gecko/nsstring" }
+bincode = "1.0"
+uuid = {version = "0.1.18"}
+fxhash = "0.2.1"
 
 [dependencies.webrender]
 path = "../webrender"
 version = "0.57.2"
 default-features = false
-features = ["capture"]
+features = ["capture", "serialize_program"]
 
 [target.'cfg(target_os = "windows")'.dependencies]
 dwrote = "0.4.1"

gfx/webrender_bindings/RenderThread.cpp

@@ -70,6 +70,16 @@ RenderThread::Start()
   widget::WinCompositorWindowThread::Start();
 #endif
   layers::SharedSurfacesParent::Initialize();
+
+  if (XRE_IsGPUProcess() &&
+      gfx::gfxVars::UseWebRenderProgramBinary()) {
+    MOZ_ASSERT(gfx::gfxVars::UseWebRender());
+    // Initialize program cache if necessary
+    RefPtr<Runnable> runnable = WrapRunnable(
+      RefPtr<RenderThread>(sRenderThread.get()),
+      &RenderThread::ProgramCacheTask);
+    sRenderThread->Loop()->PostTask(runnable.forget());
+  }
 }
 
 // static
@@ -511,13 +521,19 @@ RenderThread::GetRenderTexture(wr::WrExternalImageId aExternalImageId)
   return mRenderTextures.GetWeak(aExternalImageId.mHandle);
 }
 
+void
+RenderThread::ProgramCacheTask()
+{
+  ProgramCache();
+}
+
 WebRenderProgramCache*
 RenderThread::ProgramCache()
 {
   MOZ_ASSERT(IsInRenderThread());
 
   if (!mProgramCache) {
-    mProgramCache = MakeUnique<WebRenderProgramCache>();
+    mProgramCache = MakeUnique<WebRenderProgramCache>(ThreadPool().Raw());
   }
   return mProgramCache.get();
 }
@@ -532,9 +548,16 @@ WebRenderThreadPool::~WebRenderThreadPool()
   wr_thread_pool_delete(mThreadPool);
 }
 
-WebRenderProgramCache::WebRenderProgramCache()
+WebRenderProgramCache::WebRenderProgramCache(wr::WrThreadPool* aThreadPool)
 {
-  mProgramCache = wr_program_cache_new();
+  MOZ_ASSERT(aThreadPool);
+
+  nsAutoString path;
+  if (gfxVars::UseWebRenderProgramBinaryDisk()) {
+    path.Append(gfx::gfxVars::ProfDirectory());
+  }
+  mProgramCache = wr_program_cache_new(&path, aThreadPool);
+  wr_try_load_shader_from_disk(mProgramCache);
 }
 
 WebRenderProgramCache::~WebRenderProgramCache()

gfx/webrender_bindings/RenderThread.h

@@ -42,7 +42,7 @@ protected:
 
 class WebRenderProgramCache {
 public:
-  WebRenderProgramCache();
+  explicit WebRenderProgramCache(wr::WrThreadPool* aThreadPool);
 
   ~WebRenderProgramCache();
 
@@ -170,6 +170,7 @@ private:
 
   void DeferredRenderTextureHostDestroy(RefPtr<RenderTextureHost> aTexture);
   void ShutDownTask(layers::SynchronousTask* aTask);
+  void ProgramCacheTask();
 
   ~RenderThread();
 

gfx/webrender_bindings/src/bindings.rs

@@ -13,12 +13,14 @@ use webrender::{ExternalImage, ExternalImageHandler, ExternalImageSource};
 use webrender::DebugFlags;
 use webrender::{ApiRecordingReceiver, BinaryRecorder};
 use webrender::{AsyncPropertySampler, PipelineInfo, SceneBuilderHooks};
-use webrender::{ProgramCache, UploadMethod, VertexUsageHint};
+use webrender::{UploadMethod, VertexUsageHint};
 use thread_profiler::register_thread_with_profiler;
 use moz2d_renderer::Moz2dImageRenderer;
+use program_cache::{WrProgramCache, remove_disk_cache};
 use app_units::Au;
 use rayon;
 use euclid::SideOffsets2D;
+use nsstring::nsAString;
 
 #[cfg(target_os = "windows")]
 use dwrote::{FontDescriptor, FontWeight, FontStretch, FontStyle};
@@ -827,23 +829,40 @@ pub unsafe extern "C" fn wr_thread_pool_delete(thread_pool: *mut WrThreadPool) {
     Box::from_raw(thread_pool);
 }
 
-pub struct WrProgramCache(Rc<ProgramCache>);
-
 #[no_mangle]
-pub unsafe extern "C" fn wr_program_cache_new() -> *mut WrProgramCache {
-    let program_cache = ProgramCache::new(None);
-    Box::into_raw(Box::new(WrProgramCache(program_cache)))
+pub unsafe extern "C" fn wr_program_cache_new(prof_path: &nsAString, thread_pool: *mut WrThreadPool) -> *mut WrProgramCache {
+    let workers = &(*thread_pool).0;
+    let program_cache = WrProgramCache::new(prof_path, workers);
+    Box::into_raw(Box::new(program_cache))
 }
 
 /// cbindgen:postfix=WR_DESTRUCTOR_SAFE_FUNC
 #[no_mangle]
 pub unsafe extern "C" fn wr_program_cache_delete(program_cache: *mut WrProgramCache) {
-    Rc::from_raw(program_cache);
+    Box::from_raw(program_cache);
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn wr_try_load_shader_from_disk(program_cache: *mut WrProgramCache) {
+    if !program_cache.is_null() {
+        (*program_cache).try_load_from_disk();
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn remove_program_binary_disk_cache(prof_path: &nsAString) -> bool {
+    match remove_disk_cache(prof_path) {
+        Ok(_) => true,
+        Err(_) => {
+            error!("Failed to remove program binary disk cache");
+            false
+        }
+    }
 }
 
 #[no_mangle]
 pub extern "C" fn wr_renderer_update_program_cache(renderer: &mut Renderer, program_cache: &mut WrProgramCache) {
-    let program_cache = Rc::clone(&program_cache.0);
+    let program_cache = Rc::clone(&program_cache.rc_get());
     renderer.update_program_cache(program_cache);
 }
 

gfx/webrender_bindings/src/lib.rs

@@ -8,8 +8,12 @@ extern crate webrender;
 extern crate euclid;
 extern crate app_units;
 extern crate gleam;
+extern crate nsstring;
 extern crate rayon;
 extern crate thread_profiler;
+extern crate bincode;
+extern crate uuid;
+extern crate fxhash;
 
 #[macro_use]
 extern crate log;
@@ -17,6 +21,7 @@ extern crate log;
 #[cfg(target_os = "windows")]
 extern crate dwrote;
 
+
 #[cfg(target_os = "macos")]
 extern crate core_foundation;
 #[cfg(target_os = "macos")]
@@ -24,6 +29,8 @@ extern crate core_graphics;
 #[cfg(target_os = "macos")]
 extern crate foreign_types;
 
+mod program_cache;
+
 #[allow(non_snake_case)]
 pub mod bindings;
 pub mod moz2d_renderer;

gfx/webrender_bindings/src/program_cache.rs

@@ -0,0 +1,298 @@
+use std::cell::RefCell;
+use std::io::{Error, ErrorKind};
+use std::fs::{File, create_dir_all, read_dir};
+use std::io::{Read, Write};
+use std::path::{PathBuf};
+use std::rc::Rc;
+use std::sync::Arc;
+
+use webrender::{ProgramBinary, ProgramCache, ProgramCacheObserver};
+use bincode;
+use fxhash;
+use nsstring::nsAString;
+use rayon::ThreadPool;
+use uuid::Uuid;
+
+const MAX_LOAD_TIME_MS: u64 = 400;
+const MAX_CACHED_PROGRAM_COUNT: u32 = 15;
+
+fn deserialize_program_binary(path: &PathBuf) -> Result<Arc<ProgramBinary>, Error> {
+    let mut buf = vec![];
+    let mut file = File::open(path)?;
+    file.read_to_end(&mut buf)?;
+
+    if buf.len() <= 8 {
+        return Err(Error::new(ErrorKind::InvalidData, "File size is too small"));
+    }
+    let hash = &buf[0 .. 8];
+    let data = &buf[8 ..];
+
+    // Check if hash is correct
+    let hash:u64 = bincode::deserialize(&hash).unwrap();
+    let hash_data = fxhash::hash64(&data);
+    if hash != hash_data {
+        return Err(Error::new(ErrorKind::InvalidData, "File data is invalid"));
+    }
+
+    // Deserialize ProgramBinary
+    let binary = match bincode::deserialize(&data) {
+        Ok(binary) => binary,
+        Err(_) => return Err(Error::new(ErrorKind::InvalidData, "Failed to deserialize ProgramBinary")),
+    };
+
+    Ok(Arc::new(binary))
+}
+
+#[cfg(target_os = "windows")]
+fn get_cache_path_from_prof_path(prof_path: &nsAString) -> Option<PathBuf> {
+    if prof_path.is_empty() {
+        // Empty means that we do not use disk cache.
+        return None;
+    }
+
+    use std::ffi::OsString;
+    use std::os::windows::prelude::*;
+
+    let prof_path = OsString::from_wide(prof_path.as_ref());
+    let mut cache_path = PathBuf::from(&prof_path);
+    cache_path.push("shader-cache");
+
+    Some(cache_path)
+}
+
+#[cfg(not(target_os="windows"))]
+fn get_cache_path_from_prof_path(_prof_path: &nsAString) -> Option<PathBuf> {
+    // Not supported yet.
+    None
+}
+
+struct WrProgramBinaryDiskCache {
+    cache_path: Option<PathBuf>,
+    program_count: u32,
+    is_enabled: bool,
+    workers: Arc<ThreadPool>,
+}
+
+impl WrProgramBinaryDiskCache {
+    #[allow(dead_code)]
+    fn new(prof_path: &nsAString, workers: &Arc<ThreadPool>) -> Self {
+        let cache_path = get_cache_path_from_prof_path(prof_path);
+        let is_enabled = cache_path.is_some();
+        let workers = Arc::clone(workers);
+
+        WrProgramBinaryDiskCache{
+            cache_path,
+            program_count: 0,
+            is_enabled,
+            workers,
+        }
+    }
+
+    fn notify_binary_added(&mut self, program_binary: &Arc<ProgramBinary>) {
+        if !self.is_enabled {
+            return;
+        }
+
+        if let Some(ref cache_path) = self.cache_path {
+            if let Err(_) = create_dir_all(&cache_path) {
+                error!("failed to create dir for shader disk cache");
+                return;
+            }
+
+            self.program_count += 1;
+            if self.program_count > MAX_CACHED_PROGRAM_COUNT {
+                // Disable disk cache to avoid storing more shader programs to disk
+                self.is_enabled = false;
+                return;
+            }
+
+            // Use uuid for file name
+            let uuid1 = Uuid::new_v4();
+            let file_name = uuid1.to_hyphenated_string();
+            let program_binary = Arc::clone(program_binary);
+            let file_path = cache_path.join(&file_name);
+
+            let program_count = self.program_count;
+
+            // Save to disk on worker thread
+            self.workers.spawn(move || {
+
+                use std::time::{Instant};
+                let start = Instant::now();
+
+                let data: Vec<u8> = match bincode::serialize(&*program_binary) {
+                    Ok(data) => data,
+                    Err(err) => {
+                        error!("Failed to serialize program binary error: {}", err);
+                        return;
+                    }
+                };
+
+                let mut file = match File::create(&file_path) {
+                    Ok(file) => file,
+                    Err(err) => {
+                        error!("Unable to create file for program binary error: {}", err);
+                        return;
+                    }
+                };
+
+                // Write hash
+                let hash = fxhash::hash64(&data);
+                let hash = bincode::serialize(&hash).unwrap();
+                assert!(hash.len() == 8);
+                match file.write_all(&hash) {
+                    Err(err) => {
+                        error!("Failed to write hash to file error: {}", err);
+                    }
+                    _ => {},
+                };
+
+                // Write serialized data
+                match file.write_all(&data) {
+                    Err(err) => {
+                        error!("Failed to write program binary to file error: {}", err);
+                    }
+                    _ => {},
+                };
+
+                let elapsed = start.elapsed();
+                info!("notify_binary_added: {} ms program_count {}",
+                    (elapsed.as_secs() * 1_000) + (elapsed.subsec_nanos() / 1_000_000) as u64, program_count);
+
+            });
+        }
+    }
+
+    pub fn try_load_from_disk(&mut self, program_cache: &Rc<ProgramCache>) {
+        if !self.is_enabled {
+            return;
+        }
+
+        if let Some(ref cache_path) = self.cache_path {
+            use std::time::{Instant};
+            let start = Instant::now();
+
+            // Load program binaries if exist
+            if cache_path.exists() && cache_path.is_dir() {
+                for entry in read_dir(cache_path).unwrap() {
+                    let entry = entry.unwrap();
+                    let path = entry.path();
+
+                    info!("loading shader file");
+
+                    match deserialize_program_binary(&path) {
+                        Ok(program) => {
+                            program_cache.load_program_binary(program);
+                        }
+                        Err(err) => {
+                            error!("Failed to desriralize program binary error: {}", err);
+                        }
+                    };
+
+                    self.program_count += 1;
+
+                    let elapsed = start.elapsed();
+                    let elapsed_ms = (elapsed.as_secs() * 1_000) + (elapsed.subsec_nanos() / 1_000_000) as u64;
+                    info!("deserialize_program_binary: {} ms program_count {}", elapsed_ms, self.program_count);
+
+                    if self.program_count > MAX_CACHED_PROGRAM_COUNT || elapsed_ms > MAX_LOAD_TIME_MS {
+                        // Disable disk cache to avoid storing more shader programs to disk
+                        self.is_enabled = false;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+}
+
+pub struct WrProgramCacheObserver {
+    disk_cache: Rc<RefCell<WrProgramBinaryDiskCache>>,
+}
+
+impl WrProgramCacheObserver {
+    #[allow(dead_code)]
+    fn new(disk_cache: Rc<RefCell<WrProgramBinaryDiskCache>>) -> Self {
+        WrProgramCacheObserver{
+            disk_cache,
+        }
+    }
+}
+
+impl ProgramCacheObserver for WrProgramCacheObserver {
+    fn notify_binary_added(&self, program_binary: &Arc<ProgramBinary>) {
+        self.disk_cache.borrow_mut().notify_binary_added(program_binary);
+    }
+
+    fn notify_program_binary_failed(&self, _program_binary: &Arc<ProgramBinary>) {
+        error!("Failed program_binary");
+    }
+}
+
+
+pub struct WrProgramCache {
+    program_cache: Rc<ProgramCache>,
+    disk_cache: Option<Rc<RefCell<WrProgramBinaryDiskCache>>>,
+}
+
+impl WrProgramCache {
+    #[cfg(target_os = "windows")]
+    pub fn new(prof_path: &nsAString, workers: &Arc<ThreadPool>) -> Self {
+        let disk_cache = Rc::new(RefCell::new(WrProgramBinaryDiskCache::new(prof_path, workers)));
+        let program_cache_observer = Box::new(WrProgramCacheObserver::new(Rc::clone(&disk_cache)));
+        let program_cache = ProgramCache::new(Some(program_cache_observer));
+
+        WrProgramCache {
+            program_cache,
+            disk_cache: Some(disk_cache),
+        }
+    }
+
+    #[cfg(not(target_os="windows"))]
+    pub fn new(_prof_path: &nsAString, _: &Arc<ThreadPool>) -> Self {
+        let program_cache = ProgramCache::new(None);
+
+        WrProgramCache {
+            program_cache,
+            disk_cache: None,
+        }
+    }
+
+    pub fn rc_get(&self) -> &Rc<ProgramCache> {
+        &self.program_cache
+    }
+
+    pub fn try_load_from_disk(&self) {
+        if let Some(ref disk_cache) = self.disk_cache {
+            disk_cache.borrow_mut().try_load_from_disk(&self.program_cache);
+        } else {
+            error!("Shader disk cache is not supported");
+        }
+    }
+}
+
+#[cfg(target_os = "windows")]
+pub fn remove_disk_cache(prof_path: &nsAString) -> Result<(), Error> {
+    use std::fs::remove_dir_all;
+    use std::time::{Instant};
+
+    if let Some(cache_path) = get_cache_path_from_prof_path(prof_path) {
+        if cache_path.exists() {
+            let start = Instant::now();
+
+            remove_dir_all(&cache_path)?;
+
+            let elapsed = start.elapsed();
+            let elapsed_ms = (elapsed.as_secs() * 1_000) + (elapsed.subsec_nanos() / 1_000_000) as u64;
+            info!("remove_disk_cache: {} ms", elapsed_ms);
+        }
+    }
+    Ok(())
+}
+
+#[cfg(not(target_os="windows"))]
+pub fn remove_disk_cache(_prof_path: &nsAString) -> Result<(), Error> {
+    error!("Shader disk cache is not supported");
+    return Err(Error::new(ErrorKind::Other, "Not supported"))
+}
+

gfx/webrender_bindings/webrender_ffi_generated.h

@@ -17,6 +17,10 @@
 namespace mozilla {
 namespace wr {
 
+static const uint32_t MAX_CACHED_PROGRAM_COUNT = 15;
+
+static const uint64_t MAX_LOAD_TIME_MS = 400;
+
 enum class BorderStyle : uint32_t {
   None = 0,
   Solid = 1,
@@ -1000,6 +1004,10 @@ extern bool is_in_main_thread();
 
 extern bool is_in_render_thread();
 
+WR_INLINE
+bool remove_program_binary_disk_cache(const nsAString *aProfPath)
+WR_FUNC;
+
 WR_INLINE
 const VecU8 *wr_add_ref_arc(const ArcVecU8 *aArc)
 WR_FUNC;
@@ -1411,7 +1419,8 @@ void wr_program_cache_delete(WrProgramCache *aProgramCache)
 WR_DESTRUCTOR_SAFE_FUNC;
 
 WR_INLINE
-WrProgramCache *wr_program_cache_new()
+WrProgramCache *wr_program_cache_new(const nsAString *aProfPath,
+                                     WrThreadPool *aThreadPool)
 WR_FUNC;
 
 WR_INLINE
@@ -1662,6 +1671,10 @@ void wr_transaction_update_epoch(Transaction *aTxn,
                                  WrEpoch aEpoch)
 WR_FUNC;
 
+WR_INLINE
+void wr_try_load_shader_from_disk(WrProgramCache *aProgramCache)
+WR_FUNC;
+
 WR_INLINE
 void wr_vec_u8_free(WrVecU8 aV)
 WR_FUNC;

ipc/glue/IPCStream.ipdlh

@@ -34,6 +34,8 @@ struct IPCRemoteStream
   bool delayedStart;
 
   IPCRemoteStreamType stream;
+
+  int64_t length;
 };
 
 // Use IPCStream or OptionalIPCStream in your ipdl to represent serialized

ipc/glue/IPCStreamDestination.cpp

@@ -5,6 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "IPCStreamDestination.h"
+#include "mozilla/InputStreamLengthWrapper.h"
 #include "mozilla/Mutex.h"
 #include "nsIAsyncInputStream.h"
 #include "nsIAsyncOutputStream.h"
@@ -264,6 +265,9 @@ NS_INTERFACE_MAP_END
 IPCStreamDestination::IPCStreamDestination()
   : mOwningThread(NS_GetCurrentThread())
   , mDelayedStart(false)
+#ifdef MOZ_DEBUG
+  , mLengthSet(false)
+#endif
 {
 }
 
@@ -302,6 +306,24 @@ IPCStreamDestination::SetDelayedStart(bool aDelayedStart)
   mDelayedStart = aDelayedStart;
 }
 
+void
+IPCStreamDestination::SetLength(int64_t aLength)
+{
+  MOZ_ASSERT(mReader);
+  MOZ_ASSERT(!mLengthSet);
+
+#ifdef DEBUG
+  mLengthSet = true;
+#endif
+
+  if (aLength != -1) {
+    nsCOMPtr<nsIInputStream> finalStream;
+    finalStream = new InputStreamLengthWrapper(mReader.forget(), aLength);
+    mReader = do_QueryInterface(finalStream);
+    MOZ_ASSERT(mReader);
+  }
+}
+
 already_AddRefed<nsIInputStream>
 IPCStreamDestination::TakeReader()
 {

ipc/glue/IPCStreamDestination.h

@@ -39,6 +39,9 @@ public:
   void
   SetDelayedStart(bool aDelayedStart);
 
+  void
+  SetLength(int64_t aLength);
+
   already_AddRefed<nsIInputStream>
   TakeReader();
 
@@ -96,6 +99,10 @@ private:
 
   nsCOMPtr<nsIThread> mOwningThread;
   bool mDelayedStart;
+
+#ifdef MOZ_DEBUG
+  bool mLengthSet;
+#endif
 };
 
 } // namespace ipc

ipc/glue/IPCStreamUtils.cpp

@@ -9,6 +9,7 @@
 #include "nsIIPCSerializableInputStream.h"
 
 #include "mozilla/Assertions.h"
+#include "mozilla/InputStreamLengthHelper.h"
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/File.h"
@@ -137,6 +138,14 @@ SerializeInputStream(nsIInputStream* aStream, IPCStream& aValue, M* aManager,
   MOZ_ASSERT(aStream);
   MOZ_ASSERT(aManager);
 
+  // Let's try to take the length using InputStreamLengthHelper. If the length
+  // cannot be taken synchronously, and its length is needed, the stream needs
+  // to be fully copied in memory on the deserialization side.
+  int64_t length;
+  if (!InputStreamLengthHelper::GetSyncLength(aStream, &length)) {
+    length = -1;
+  }
+
   // As a fallback, attempt to stream the data across using a IPCStream
   // actor. For blocking streams, create a nonblocking pipe instead,
   nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(aStream);
@@ -168,6 +177,7 @@ SerializeInputStream(nsIInputStream* aStream, IPCStream& aValue, M* aManager,
   IPCRemoteStream remoteStream;
   remoteStream.delayedStart() = aDelayedStart;
   remoteStream.stream() = IPCStreamSource::Create(asyncStream, aManager);
+  remoteStream.length() = length;
   aValue = remoteStream;
 
   return true;
@@ -379,6 +389,7 @@ DeserializeIPCStream(const IPCStream& aValue)
     }
 
     destinationStream->SetDelayedStart(remoteStream.delayedStart());
+    destinationStream->SetLength(remoteStream.length());
     return destinationStream->TakeReader();
   }
 

ipc/glue/InputStreamParams.ipdlh

@@ -61,6 +61,7 @@ union InputStreamParams
   MultiplexInputStreamParams;
   SlicedInputStreamParams;
   IPCBlobInputStreamParams;
+  InputStreamLengthWrapperParams;
 };
 
 union OptionalInputStreamParams
@@ -82,5 +83,12 @@ struct MIMEInputStreamParams
   bool startedReading;
 };
 
+struct InputStreamLengthWrapperParams
+{
+  InputStreamParams stream;
+  int64_t length;
+  bool consumed;
+};
+
 } // namespace ipc
 } // namespace mozilla

ipc/glue/InputStreamUtils.cpp

@@ -13,6 +13,7 @@
 #include "mozilla/dom/ipc/IPCBlobInputStream.h"
 #include "mozilla/dom/ipc/IPCBlobInputStreamStorage.h"
 #include "mozilla/SlicedInputStream.h"
+#include "mozilla/InputStreamLengthWrapper.h"
 #include "nsComponentManagerUtils.h"
 #include "nsDebug.h"
 #include "nsID.h"
@@ -100,6 +101,10 @@ InputStreamHelper::DeserializeInputStream(const InputStreamParams& aParams,
       serializable = new mozilla::SlicedInputStream();
       break;
 
+    case InputStreamParams::TInputStreamLengthWrapperParams:
+      serializable = new mozilla::InputStreamLengthWrapper();
+      break;
+
     default:
       MOZ_ASSERT(false, "Unknown params!");
       return nullptr;

js/public/Realm.h

@@ -97,8 +97,8 @@ typedef void
 extern JS_PUBLIC_API(void)
 SetRealmNameCallback(JSContext* cx, RealmNameCallback callback);
 
-// Get the global object for the given realm. Returns null only if `realm` is
-// the atoms realm.
+// Get the global object for the given realm. This only returns nullptr during
+// GC, between collecting the global object and destroying the Realm.
 extern JS_PUBLIC_API(JSObject*)
 GetRealmGlobalOrNull(Handle<Realm*> realm);
 

js/public/RootingAPI.h

@@ -884,7 +884,7 @@ class RootingContext
         return reinterpret_cast<RootingContext*>(cx);
     }
 
-    friend JSCompartment* js::GetContextCompartment(const JSContext* cx);
+    friend JS::Realm* js::GetContextRealm(const JSContext* cx);
     friend JS::Zone* js::GetContextZone(const JSContext* cx);
 };
 
@@ -1054,10 +1054,16 @@ namespace js {
  *   usable without resorting to jsfriendapi.h, and when JSContext is an
  *   incomplete type.
  */
+inline JS::Realm*
+GetContextRealm(const JSContext* cx)
+{
+    return JS::RootingContext::get(cx)->realm_;
+}
+
 inline JSCompartment*
 GetContextCompartment(const JSContext* cx)
 {
-    return GetCompartmentForRealm(JS::RootingContext::get(cx)->realm_);
+    return GetCompartmentForRealm(GetContextRealm(cx));
 }
 
 inline JS::Zone*

js/public/Wrapper.h

@@ -378,9 +378,6 @@ UncheckedUnwrapWithoutExpose(JSObject* obj);
 void
 ReportAccessDenied(JSContext* cx);
 
-JS_FRIEND_API(bool)
-IsCrossCompartmentWrapper(JSObject* obj);
-
 JS_FRIEND_API(void)
 NukeCrossCompartmentWrapper(JSContext* cx, JSObject* wrapper);
 

js/rust/build.rs

@@ -174,6 +174,7 @@ const WHITELIST_TYPES: &'static [&'static str] = &[
     "JSAutoStructuredCloneBuffer",
     "JSClass",
     "JSClassOps",
+    "JSCompartment",
     "JSContext",
     "JSErrNum",
     "JSErrorCallback",

js/rust/src/rust.rs

@@ -1055,7 +1055,7 @@ pub unsafe fn get_object_class(obj: *mut JSObject) -> *const JSClass {
 
 #[inline]
 pub unsafe fn get_object_compartment(obj: *mut JSObject) -> *mut JSCompartment {
-    (*get_object_group(obj)).compartment
+    (*get_object_group(obj)).realm as *mut JSCompartment
 }
 
 #[inline]

js/src/builtin/Object.cpp

@@ -1999,7 +1999,7 @@ CreateObjectConstructor(JSContext* cx, JSProtoKey key)
 static JSObject*
 CreateObjectPrototype(JSContext* cx, JSProtoKey key)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     MOZ_ASSERT(cx->global()->isNative());
 
     /*

js/src/frontend/BytecodeEmitter.cpp

@@ -1507,7 +1507,8 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
 // Usage: (check for the return value is omitted for simplicity)
 //
 //   `try { try_block } catch (ex) { catch_block }`
-//     TryEmitter tryCatch(this, TryEmitter::TryCatch);
+//     TryEmitter tryCatch(this, TryEmitter::Kind::TryCatch,
+//                         TryEmitter::ControlKind::Syntactic);
 //     tryCatch.emitTry();
 //     emit(try_block);
 //     tryCatch.emitCatch();
@@ -1515,7 +1516,8 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
 //     tryCatch.emitEnd();
 //
 //   `try { try_block } finally { finally_block }`
-//     TryEmitter tryCatch(this, TryEmitter::TryFinally);
+//     TryEmitter tryCatch(this, TryEmitter::Kind::TryFinally,
+//                         TryEmitter::ControlKind::Syntactic);
 //     tryCatch.emitTry();
 //     emit(try_block);
 //     // finally_pos: The "{" character's position in the source code text.
@@ -1524,7 +1526,8 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
 //     tryCatch.emitEnd();
 //
 //   `try { try_block } catch (ex) {catch_block} finally { finally_block }`
-//     TryEmitter tryCatch(this, TryEmitter::TryCatchFinally);
+//     TryEmitter tryCatch(this, TryEmitter::Kind::TryCatchFinally,
+//                         TryEmitter::ControlKind::Syntactic);
 //     tryCatch.emitTry();
 //     emit(try_block);
 //     tryCatch.emitCatch();
@@ -1536,17 +1539,23 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
 class MOZ_STACK_CLASS TryEmitter
 {
   public:
-    enum Kind {
+    enum class Kind {
         TryCatch,
         TryCatchFinally,
         TryFinally
     };
 
-    // Whether the catch and finally blocks handle the frame's return value.
-    // If UseRetVal is specified, the bytecode marked with "*" are emitted
-    // to clear return value with `undefined` before the catch block and the
-    // finally block, and also to save/restore the return value before/after
-    // the finally block.
+    // Syntactic try-catch-finally and internally used non-syntactic
+    // try-catch-finally behave differently for 2 points.
+    //
+    // The first one is whether TryFinallyControl is used or not.
+    // See the comment for `controlInfo_`.
+    //
+    // The second one is whether the catch and finally blocks handle the frame's
+    // return value.  For syntactic try-catch-finally, the bytecode marked with
+    // "*" are emitted to clear return value with `undefined` before the catch
+    // block and the finally block, and also to save/restore the return value
+    // before/after the finally block.
     //
     //     JSOP_TRY
     //
@@ -1581,27 +1590,17 @@ class MOZ_STACK_CLASS TryEmitter
     //   end:
     //     JSOP_JUMPTARGET
     //
-    // For syntactic try-catch-finally, UseRetVal should be used.
-    // For non-syntactic try-catch-finally, DontUseRetVal should be used.
-    enum ShouldUseRetVal {
-        UseRetVal,
-        DontUseRetVal
-    };
-
-    // Whether this class should use TryFinallyControl.
-    // See the comment for `controlInfo_`.
-    //
-    // For syntactic try-catch-finally, UseControl should be used.
-    // For non-syntactic try-catch-finally, DontUseControl should be used.
-    enum ShouldUseControl {
-        UseControl,
-        DontUseControl,
+    // For syntactic try-catch-finally, Syntactic should be used.
+    // For non-syntactic try-catch-finally, NonSyntactic should be used.
+    enum class ControlKind {
+        Syntactic,
+        NonSyntactic
     };
 
   private:
     BytecodeEmitter* bce_;
     Kind kind_;
-    ShouldUseRetVal retValKind_;
+    ControlKind controlKind_;
 
     // Track jumps-over-catches and gosubs-to-finally for later fixup.
     //
@@ -1609,19 +1608,17 @@ class MOZ_STACK_CLASS TryEmitter
     // jumps-over-catches) result in a GOSUB being written into the bytecode
     // stream and fixed-up later.
     //
-    // If ShouldUseControl is DontUseControl, all that handling is skipped.
-    // DontUseControl is used by yield* and the internal try-catch around
-    // IteratorClose. These internal uses must:
+    // For non-syntactic try-catch-finally, all that handling is skipped.
+    // The non-syntactic try-catch-finally must:
     //   * have only one catch block
     //   * have JSOP_GOTO at the end of catch-block
     //   * have no non-local-jump
     //   * don't use finally block for normal completion of try-block and
     //     catch-block
     //
-    // Additionally, a finally block may be emitted when ShouldUseControl is
-    // DontUseControl, even if the kind is not TryCatchFinally or TryFinally,
-    // because GOSUBs are not emitted. This internal use shares the
-    // requirements as above.
+    // Additionally, a finally block may be emitted for non-syntactic
+    // try-catch-finally, even if the kind is TryCatch, because GOSUBs are not
+    // emitted.
     Maybe<TryFinallyControl> controlInfo_;
 
     // The stack depth before emitting JSOP_TRY.
@@ -1642,6 +1639,7 @@ class MOZ_STACK_CLASS TryEmitter
     // The offset of JSOP_JUMPTARGET at the beginning of the finally block.
     JumpTarget finallyStart_;
 
+#ifdef DEBUG
     // The state of this emitter.
     //
     // +-------+ emitTry +-----+   emitCatch +-------+      emitEnd  +-----+
@@ -1653,7 +1651,7 @@ class MOZ_STACK_CLASS TryEmitter
     //                           |  v emitFinally +---------+  |
     //                           +->+------------>| Finally |--+
     //                                            +---------+
-    enum State {
+    enum class State {
         // The initial state.
         Start,
 
@@ -1670,40 +1668,42 @@ class MOZ_STACK_CLASS TryEmitter
         End
     };
     State state_;
+#endif
 
     bool hasCatch() const {
-        return kind_ == TryCatch || kind_ == TryCatchFinally;
+        return kind_ == Kind::TryCatch || kind_ == Kind::TryCatchFinally;
     }
     bool hasFinally() const {
-        return kind_ == TryCatchFinally || kind_ == TryFinally;
+        return kind_ == Kind::TryCatchFinally || kind_ == Kind::TryFinally;
     }
 
   public:
-    TryEmitter(BytecodeEmitter* bce, Kind kind, ShouldUseRetVal retValKind = UseRetVal,
-               ShouldUseControl controlKind = UseControl)
+    TryEmitter(BytecodeEmitter* bce, Kind kind, ControlKind controlKind)
       : bce_(bce),
         kind_(kind),
-        retValKind_(retValKind),
+        controlKind_(controlKind),
         depth_(0),
         noteIndex_(0),
-        tryStart_(0),
-        state_(Start)
+        tryStart_(0)
+#ifdef DEBUG
+      , state_(State::Start)
+#endif
     {
-        if (controlKind == UseControl)
+        if (controlKind_ == ControlKind::Syntactic)
             controlInfo_.emplace(bce_, hasFinally() ? StatementKind::Finally : StatementKind::Try);
         finallyStart_.offset = 0;
     }
 
     // Emits JSOP_GOTO to the end of try-catch-finally.
     // Used in `yield*`.
-    bool emitJumpOverCatchAndFinally() {
+    MOZ_MUST_USE bool emitJumpOverCatchAndFinally() {
         if (!bce_->emitJump(JSOP_GOTO, &catchAndFinallyJump_))
             return false;
         return true;
     }
 
-    bool emitTry() {
-        MOZ_ASSERT(state_ == Start);
+    MOZ_MUST_USE bool emitTry() {
+        MOZ_ASSERT(state_ == State::Start);
 
         // Since an exception can be thrown at any place inside the try block,
         // we need to restore the stack and the scope chain before we transfer
@@ -1721,13 +1721,15 @@ class MOZ_STACK_CLASS TryEmitter
             return false;
         tryStart_ = bce_->offset();
 
-        state_ = Try;
+#ifdef DEBUG
+        state_ = State::Try;
+#endif
         return true;
     }
 
   private:
-    bool emitTryEnd() {
-        MOZ_ASSERT(state_ == Try);
+    MOZ_MUST_USE bool emitTryEnd() {
+        MOZ_ASSERT(state_ == State::Try);
         MOZ_ASSERT(depth_ == bce_->stackDepth);
 
         // GOSUB to finally, if present.
@@ -1751,14 +1753,14 @@ class MOZ_STACK_CLASS TryEmitter
     }
 
   public:
-    bool emitCatch() {
-        MOZ_ASSERT(state_ == Try);
+    MOZ_MUST_USE bool emitCatch() {
+        MOZ_ASSERT(state_ == State::Try);
         if (!emitTryEnd())
             return false;
 
         MOZ_ASSERT(bce_->stackDepth == depth_);
 
-        if (retValKind_ == UseRetVal) {
+        if (controlKind_ == ControlKind::Syntactic) {
             // Clear the frame's return value that might have been set by the
             // try block:
             //
@@ -1769,13 +1771,15 @@ class MOZ_STACK_CLASS TryEmitter
                 return false;
         }
 
-        state_ = Catch;
+#ifdef DEBUG
+        state_ = State::Catch;
+#endif
         return true;
     }
 
   private:
-    bool emitCatchEnd() {
-        MOZ_ASSERT(state_ == Catch);
+    MOZ_MUST_USE bool emitCatchEnd() {
+        MOZ_ASSERT(state_ == State::Catch);
 
         if (!controlInfo_)
             return true;
@@ -1799,24 +1803,26 @@ class MOZ_STACK_CLASS TryEmitter
     // "{" character in the source code text, to improve line:column number in
     // the error reporting.
     // For non-syntactic try-catch-finally, `finallyPos` can be omitted.
-    bool emitFinally(const Maybe<uint32_t>& finallyPos = Nothing()) {
+    MOZ_MUST_USE bool emitFinally(const Maybe<uint32_t>& finallyPos = Nothing()) {
         // If we are using controlInfo_ (i.e., emitting a syntactic try
         // blocks), we must have specified up front if there will be a finally
-        // close. For internal try blocks, like those emitted for yield* and
-        // IteratorClose inside for-of loops, we can emitFinally even without
-        // specifying up front, since the internal try blocks emit no GOSUBs.
+        // close. For internal non-syntactic try blocks, like those emitted for
+        // yield* and IteratorClose inside for-of loops, we can emitFinally even
+        // without specifying up front, since the internal non-syntactic try
+        // blocks emit no GOSUBs.
         if (!controlInfo_) {
-            if (kind_ == TryCatch)
-                kind_ = TryCatchFinally;
+            if (kind_ == Kind::TryCatch)
+                kind_ = Kind::TryCatchFinally;
         } else {
             MOZ_ASSERT(hasFinally());
         }
 
-        if (state_ == Try) {
+        if (!hasCatch()) {
+            MOZ_ASSERT(state_ == State::Try);
             if (!emitTryEnd())
                 return false;
         } else {
-            MOZ_ASSERT(state_ == Catch);
+            MOZ_ASSERT(state_ == State::Catch);
             if (!emitCatchEnd())
                 return false;
         }
@@ -1841,7 +1847,7 @@ class MOZ_STACK_CLASS TryEmitter
         if (!bce_->emit1(JSOP_FINALLY))
             return false;
 
-        if (retValKind_ == UseRetVal) {
+        if (controlKind_ == ControlKind::Syntactic) {
             if (!bce_->emit1(JSOP_GETRVAL))
                 return false;
 
@@ -1855,15 +1861,17 @@ class MOZ_STACK_CLASS TryEmitter
                 return false;
         }
 
-        state_ = Finally;
+#ifdef DEBUG
+        state_ = State::Finally;
+#endif
         return true;
     }
 
   private:
-    bool emitFinallyEnd() {
-        MOZ_ASSERT(state_ == Finally);
+    MOZ_MUST_USE bool emitFinallyEnd() {
+        MOZ_ASSERT(state_ == State::Finally);
 
-        if (retValKind_ == UseRetVal) {
+        if (controlKind_ == ControlKind::Syntactic) {
             if (!bce_->emit1(JSOP_SETRVAL))
                 return false;
         }
@@ -1876,14 +1884,13 @@ class MOZ_STACK_CLASS TryEmitter
     }
 
   public:
-    bool emitEnd() {
-        if (state_ == Catch) {
-            MOZ_ASSERT(!hasFinally());
+    MOZ_MUST_USE bool emitEnd() {
+        if (!hasFinally()) {
+            MOZ_ASSERT(state_ == State::Catch);
             if (!emitCatchEnd())
                 return false;
         } else {
-            MOZ_ASSERT(state_ == Finally);
-            MOZ_ASSERT(hasFinally());
+            MOZ_ASSERT(state_ == State::Finally);
             if (!emitFinallyEnd())
                 return false;
         }
@@ -1914,34 +1921,53 @@ class MOZ_STACK_CLASS TryEmitter
                 return false;
         }
 
-        state_ = End;
+#ifdef DEBUG
+        state_ = State::End;
+#endif
         return true;
     }
 };
 
 // Class for emitting bytecode for blocks like if-then-else.
 //
-// This class can be used to emit single if-then-else block.  Cascading
-// elseif's need multiple instances of this class.
+// This class can be used to emit single if-then-else block, or cascading
+// else-if blocks.
 //
 // Usage: (check for the return value is omitted for simplicity)
 //
 //   `if (cond) then_block`
 //     IfThenElseEmitter ifThen(this);
 //     emit(cond);
-//     ifThen.emitIf();
+//     ifThen.emitThen();
 //     emit(then_block);
 //     ifThen.emitEnd();
 //
 //   `if (cond) then_block else else_block`
 //     IfThenElseEmitter ifThenElse(this);
 //     emit(cond);
-//     ifThenElse.emitIfElse();
+//     ifThenElse.emitThenElse();
 //     emit(then_block);
 //     ifThenElse.emitElse();
 //     emit(else_block);
 //     ifThenElse.emitEnd();
 //
+//   `if (c1) b1 else if (c2) b2 else if (c3) b3 else b4`
+//     IfThenElseEmitter ifThenElse(this);
+//     emit(c1);
+//     ifThenElse.emitThenElse();
+//     emit(b1);
+//     ifThenElse.emitElseIf();
+//     emit(c2);
+//     ifThenElse.emitThenElse();
+//     emit(b2);
+//     ifThenElse.emitElseIf();
+//     emit(c3);
+//     ifThenElse.emitThenElse();
+//     emit(b3);
+//     ifThenElse.emitElse();
+//     emit(b4);
+//     ifThenElse.emitEnd();
+//
 //   `cond ? then_expr : else_expr`
 //     IfThenElseEmitter condElse(this);
 //     emit(cond);
@@ -1955,7 +1981,10 @@ class MOZ_STACK_CLASS IfThenElseEmitter
 {
     BytecodeEmitter* bce_;
 
+    // Jump around the then clause, to the beginning of the else clause.
     JumpList jumpAroundThen_;
+
+    // Jump around the else clause, to the end of the entire branch.
     JumpList jumpsAroundElse_;
 
     // The stack depth before emitting the then block.
@@ -1968,67 +1997,70 @@ class MOZ_STACK_CLASS IfThenElseEmitter
     // The number of values pushed in the then and else blocks.
     int32_t pushed_;
     bool calculatedPushed_;
-#endif
 
     // The state of this emitter.
     //
-    // +-------+   emitIf     +----+                           emitEnd +-----+
-    // | Start |-+----------->| If |-------------------------+-------->| End |
-    // +-------+ |            +----+                         |         +-----+
+    // +-------+   emitCond +------+ emitElse +------+        emitEnd +-----+
+    // | Start |-+--------->| Cond |--------->| Else |------>+------->| End |
+    // +-------+ |          +------+          +------+       ^        +-----+
     //           |                                           |
-    //           | emitCond   +------+     emitElse +------+ |
-    //           +----------->| Cond |---+--------->| Else |-+
-    //           |            +------+   |          +------+
-    //           |                       |
-    //           | emitIfElse +--------+ |
-    //           +----------->| IfElse |-+
-    //                        +--------+
-    enum State {
+    //           v emitThen +------+                         |
+    //        +->+--------->| Then |------------------------>+
+    //        ^  |          +------+                         ^
+    //        |  |                                           |
+    //        |  |                                           +---+
+    //        |  |                                               |
+    //        |  | emitThenElse +----------+   emitElse +------+ |
+    //        |  +------------->| ThenElse |-+--------->| Else |-+
+    //        |                 +----------+ |          +------+
+    //        |                              |
+    //        |                              | emitElseIf +--------+
+    //        |                              +----------->| ElseIf |-+
+    //        |                                           +--------+ |
+    //        |                                                      |
+    //        +------------------------------------------------------+
+    enum class State {
         // The initial state.
         Start,
 
-        // After calling emitIf.
-        If,
+        // After calling emitThen.
+        Then,
 
         // After calling emitCond.
         Cond,
 
-        // After calling emitIfElse.
-        IfElse,
+        // After calling emitThenElse.
+        ThenElse,
 
-        // After calling Else.
+        // After calling emitElse.
         Else,
 
+        // After calling emitElseIf.
+        ElseIf,
+
         // After calling emitEnd.
         End
     };
     State state_;
+#endif
 
   public:
     explicit IfThenElseEmitter(BytecodeEmitter* bce)
       : bce_(bce),
-        thenDepth_(0),
+        thenDepth_(0)
 #ifdef DEBUG
-        pushed_(0),
-        calculatedPushed_(false),
+      , pushed_(0)
+      , calculatedPushed_(false)
+      , state_(State::Start)
 #endif
-        state_(Start)
     {}
 
     ~IfThenElseEmitter()
     {}
 
   private:
-    bool emitIf(State nextState) {
-        MOZ_ASSERT(state_ == Start || state_ == Else);
-        MOZ_ASSERT(nextState == If || nextState == IfElse || nextState == Cond);
-
-        // Clear jumpAroundThen_ offset that points previous JSOP_IFEQ.
-        if (state_ == Else)
-            jumpAroundThen_ = JumpList();
-
+    MOZ_MUST_USE bool emitIfInternal(SrcNoteType type) {
         // Emit an annotated branch-if-false around the then part.
-        SrcNoteType type = nextState == If ? SRC_IF : nextState == IfElse ? SRC_IF_ELSE : SRC_COND;
         if (!bce_->newSrcNote(type))
             return false;
         if (!bce_->emitJump(JSOP_IFEQ, &jumpAroundThen_))
@@ -2039,10 +2071,9 @@ class MOZ_STACK_CLASS IfThenElseEmitter
         // If DEBUG, this is also necessary to calculate |pushed_|.
         thenDepth_ = bce_->stackDepth;
 #else
-        if (nextState == IfElse || nextState == Cond)
+        if (type == SRC_COND || type == SRC_IF_ELSE)
             thenDepth_ = bce_->stackDepth;
 #endif
-        state_ = nextState;
         return true;
     }
 
@@ -2058,21 +2089,41 @@ class MOZ_STACK_CLASS IfThenElseEmitter
     }
 
   public:
-    bool emitIf() {
-        return emitIf(If);
+    MOZ_MUST_USE bool emitThen() {
+        MOZ_ASSERT(state_ == State::Start || state_ == State::ElseIf);
+        if (!emitIfInternal(SRC_IF))
+            return false;
+
+#ifdef DEBUG
+        state_ = State::Then;
+#endif
+        return true;
     }
 
-    bool emitCond() {
-        return emitIf(Cond);
+    MOZ_MUST_USE bool emitCond() {
+        MOZ_ASSERT(state_ == State::Start);
+        if (!emitIfInternal(SRC_COND))
+            return false;
+
+#ifdef DEBUG
+        state_ = State::Cond;
+#endif
+        return true;
     }
 
-    bool emitIfElse() {
-        return emitIf(IfElse);
+    MOZ_MUST_USE bool emitThenElse() {
+        MOZ_ASSERT(state_ == State::Start || state_ == State::ElseIf);
+        if (!emitIfInternal(SRC_IF_ELSE))
+            return false;
+
+#ifdef DEBUG
+        state_ = State::ThenElse;
+#endif
+        return true;
     }
 
-    bool emitElse() {
-        MOZ_ASSERT(state_ == IfElse || state_ == Cond);
-
+  private:
+    MOZ_MUST_USE bool emitElseInternal() {
         calculateOrCheckPushed();
 
         // Emit a jump from the end of our then part around the else part. The
@@ -2085,19 +2136,54 @@ class MOZ_STACK_CLASS IfThenElseEmitter
         if (!bce_->emitJumpTargetAndPatch(jumpAroundThen_))
             return false;
 
+        // Clear jumpAroundThen_ offset, to tell emitEnd there was an else part.
+        jumpAroundThen_ = JumpList();
+
         // Restore stack depth of the then part.
         bce_->stackDepth = thenDepth_;
-        state_ = Else;
+#ifdef DEBUG
+        state_ = State::Else;
+#endif
         return true;
     }
 
-    bool emitEnd() {
-        MOZ_ASSERT(state_ == If || state_ == Else);
+  public:
+    MOZ_MUST_USE bool emitElse() {
+        MOZ_ASSERT(state_ == State::ThenElse || state_ == State::Cond);
+
+        if (!emitElseInternal())
+            return false;
+
+#ifdef DEBUG
+        state_ = State::Else;
+#endif
+        return true;
+    }
+
+    MOZ_MUST_USE bool emitElseIf() {
+        MOZ_ASSERT(state_ == State::ThenElse);
+
+        if (!emitElseInternal())
+            return false;
+
+#ifdef DEBUG
+        state_ = State::ElseIf;
+#endif
+        return true;
+    }
+
+    MOZ_MUST_USE bool emitEnd() {
+        MOZ_ASSERT(state_ == State::Then || state_ == State::Else);
+        // If there was an else part for the last branch, jumpAroundThen_ is
+        // already fixed up when emitting the else part.
+        MOZ_ASSERT_IF(state_ == State::Then, jumpAroundThen_.offset != -1);
+        MOZ_ASSERT_IF(state_ == State::Else, jumpAroundThen_.offset == -1);
 
         calculateOrCheckPushed();
 
-        if (state_ == If) {
-            // No else part, fixup the branch-if-false to come here.
+        if (jumpAroundThen_.offset != -1) {
+            // No else part for the last branch, fixup the branch-if-false to
+            // come here.
             if (!bce_->emitJumpTargetAndPatch(jumpAroundThen_))
                 return false;
         }
@@ -2106,7 +2192,9 @@ class MOZ_STACK_CLASS IfThenElseEmitter
         if (!bce_->emitJumpTargetAndPatch(jumpsAroundElse_))
             return false;
 
-        state_ = End;
+#ifdef DEBUG
+        state_ = State::End;
+#endif
         return true;
     }
 
@@ -2186,8 +2274,7 @@ class ForOfLoopControl : public LoopControl
     }
 
     bool emitBeginCodeNeedingIteratorClose(BytecodeEmitter* bce) {
-        tryCatch_.emplace(bce, TryEmitter::TryCatch, TryEmitter::DontUseRetVal,
-                          TryEmitter::DontUseControl);
+        tryCatch_.emplace(bce, TryEmitter::Kind::TryCatch, TryEmitter::ControlKind::NonSyntactic);
 
         if (!tryCatch_->emitTry())
             return false;
@@ -2217,7 +2304,7 @@ class ForOfLoopControl : public LoopControl
             return false;
 
         IfThenElseEmitter ifIteratorIsNotClosed(bce);
-        if (!ifIteratorIsNotClosed.emitIf())      // ITER ... EXCEPTION
+        if (!ifIteratorIsNotClosed.emitThen())    // ITER ... EXCEPTION
             return false;
 
         MOZ_ASSERT(slotFromTop == unsigned(bce->stackDepth - iterDepth_));
@@ -2243,7 +2330,7 @@ class ForOfLoopControl : public LoopControl
             IfThenElseEmitter ifGeneratorClosing(bce);
             if (!bce->emit1(JSOP_ISGENCLOSING))   // ITER ... FTYPE FVALUE CLOSING
                 return false;
-            if (!ifGeneratorClosing.emitIf())     // ITER ... FTYPE FVALUE
+            if (!ifGeneratorClosing.emitThen())   // ITER ... FTYPE FVALUE
                 return false;
             if (!bce->emitDupAt(slotFromTop + 1)) // ITER ... FTYPE FVALUE ITER
                 return false;
@@ -5423,7 +5510,7 @@ BytecodeEmitter::emitIteratorCloseInScope(EmitterScope& currentScope,
     if (!emitPushNotUndefinedOrNull())                    // ... ITER RET NOT-UNDEF-OR-NULL
         return false;
 
-    if (!ifReturnMethodIsDefined.emitIfElse())            // ... ITER RET
+    if (!ifReturnMethodIsDefined.emitThenElse())          // ... ITER RET
         return false;
 
     if (completionKind == CompletionKind::Throw) {
@@ -5459,8 +5546,7 @@ BytecodeEmitter::emitIteratorCloseInScope(EmitterScope& currentScope,
     Maybe<TryEmitter> tryCatch;
 
     if (completionKind == CompletionKind::Throw) {
-        tryCatch.emplace(this, TryEmitter::TryCatch, TryEmitter::DontUseRetVal,
-                         TryEmitter::DontUseControl);
+        tryCatch.emplace(this, TryEmitter::Kind::TryCatch, TryEmitter::ControlKind::NonSyntactic);
 
         // Mutate stack to balance stack for try-catch.
         if (!emit1(JSOP_UNDEFINED))                       // ... RET ITER UNDEF
@@ -5804,7 +5890,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
                 // If spread is not the first element of the pattern,
                 // iterator can already be completed.
                                                                   // ... OBJ NEXT ITER *LREF DONE
-                if (!ifThenElse.emitIfElse())                     // ... OBJ NEXT ITER *LREF
+                if (!ifThenElse.emitThenElse())                   // ... OBJ NEXT ITER *LREF
                     return false;
 
                 if (!emitUint32Operand(JSOP_NEWARRAY, 0))         // ... OBJ NEXT ITER *LREF ARRAY
@@ -5859,7 +5945,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
         IfThenElseEmitter ifAlreadyDone(this);
         if (!isFirst) {
                                                                   // ... OBJ NEXT ITER *LREF DONE
-            if (!ifAlreadyDone.emitIfElse())                      // ... OBJ NEXT ITER *LREF
+            if (!ifAlreadyDone.emitThenElse())                    // ... OBJ NEXT ITER *LREF
                 return false;
 
             if (!emit1(JSOP_UNDEFINED))                           // ... OBJ NEXT ITER *LREF UNDEF
@@ -5894,7 +5980,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
             return false;
 
         IfThenElseEmitter ifDone(this);
-        if (!ifDone.emitIfElse())                                 // ... OBJ NEXT ITER DONE *LREF RESULT
+        if (!ifDone.emitThenElse())                               // ... OBJ NEXT ITER DONE *LREF RESULT
             return false;
 
         if (!emit1(JSOP_POP))                                     // ... OBJ NEXT ITER DONE *LREF
@@ -5946,7 +6032,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
     // IteratorClose.
                                                                   // ... OBJ NEXT ITER DONE
     IfThenElseEmitter ifDone(this);
-    if (!ifDone.emitIfElse())                                     // ... OBJ NEXT ITER
+    if (!ifDone.emitThenElse())                                   // ... OBJ NEXT ITER
         return false;
     if (!emitPopN(2))                                             // ... OBJ
         return false;
@@ -6788,14 +6874,14 @@ BytecodeEmitter::emitTry(ParseNode* pn)
     TryEmitter::Kind kind;
     if (catchScope) {
         if (finallyNode)
-            kind = TryEmitter::TryCatchFinally;
+            kind = TryEmitter::Kind::TryCatchFinally;
         else
-            kind = TryEmitter::TryCatch;
+            kind = TryEmitter::Kind::TryCatch;
     } else {
         MOZ_ASSERT(finallyNode);
-        kind = TryEmitter::TryFinally;
+        kind = TryEmitter::Kind::TryFinally;
     }
-    TryEmitter tryCatch(this, kind);
+    TryEmitter tryCatch(this, kind, TryEmitter::ControlKind::Syntactic);
 
     if (!tryCatch.emitTry())
         return false;
@@ -6852,10 +6938,10 @@ BytecodeEmitter::emitIf(ParseNode* pn)
 
     ParseNode* elseNode = pn->pn_kid3;
     if (elseNode) {
-        if (!ifThenElse.emitIfElse())
+        if (!ifThenElse.emitThenElse())
             return false;
     } else {
-        if (!ifThenElse.emitIf())
+        if (!ifThenElse.emitThen())
             return false;
     }
 
@@ -6864,14 +6950,18 @@ BytecodeEmitter::emitIf(ParseNode* pn)
         return false;
 
     if (elseNode) {
-        if (!ifThenElse.emitElse())
-            return false;
-
         if (elseNode->isKind(ParseNodeKind::If)) {
             pn = elseNode;
+
+            if (!ifThenElse.emitElseIf())
+                return false;
+
             goto if_again;
         }
 
+        if (!ifThenElse.emitElse())
+            return false;
+
         /* Emit code for the else part. */
         if (!emitTreeInBranch(elseNode))
             return false;
@@ -7074,7 +7164,7 @@ BytecodeEmitter::emitAsyncIterator()
         return false;
     if (!emit1(JSOP_NOT))                                         // OBJ ITERFN UNDEF-OR-NULL
         return false;
-    if (!ifAsyncIterIsUndefined.emitIfElse())                     // OBJ ITERFN
+    if (!ifAsyncIterIsUndefined.emitThenElse())                   // OBJ ITERFN
         return false;
 
     if (!emit1(JSOP_POP))                                         // OBJ
@@ -7389,7 +7479,7 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
 
         IfThenElseEmitter ifDone(this);
 
-        if (!ifDone.emitIf())                             // NEXT ITER RESULT
+        if (!ifDone.emitThen())                           // NEXT ITER RESULT
             return false;
 
         // Remove RESULT from the stack to release it.
@@ -8537,8 +8627,8 @@ BytecodeEmitter::emitYieldStar(ParseNode* iter)
     int32_t startDepth = stackDepth;
     MOZ_ASSERT(startDepth >= 3);
 
-    TryEmitter tryCatch(this, TryEmitter::TryCatchFinally, TryEmitter::DontUseRetVal,
-                        TryEmitter::DontUseControl);
+    TryEmitter tryCatch(this, TryEmitter::Kind::TryCatchFinally,
+                        TryEmitter::ControlKind::NonSyntactic);
     if (!tryCatch.emitJumpOverCatchAndFinally())          // NEXT ITER RESULT
         return false;
 
@@ -8582,7 +8672,7 @@ BytecodeEmitter::emitYieldStar(ParseNode* iter)
         return false;
 
     IfThenElseEmitter ifThrowMethodIsNotDefined(this);
-    if (!ifThrowMethodIsNotDefined.emitIf())              // NEXT ITER RESULT EXCEPTION ITER THROW
+    if (!ifThrowMethodIsNotDefined.emitThen())            // NEXT ITER RESULT EXCEPTION ITER THROW
         return false;
     savedDepthTemp = stackDepth;
     if (!emit1(JSOP_POP))                                 // NEXT ITER RESULT EXCEPTION ITER
@@ -8640,7 +8730,7 @@ BytecodeEmitter::emitYieldStar(ParseNode* iter)
     IfThenElseEmitter ifGeneratorClosing(this);
     if (!emit1(JSOP_ISGENCLOSING))                        // NEXT ITER RESULT FTYPE FVALUE CLOSING
         return false;
-    if (!ifGeneratorClosing.emitIf())                     // NEXT ITER RESULT FTYPE FVALUE
+    if (!ifGeneratorClosing.emitThen())                   // NEXT ITER RESULT FTYPE FVALUE
         return false;
 
     // Step ii.
@@ -8664,7 +8754,7 @@ BytecodeEmitter::emitYieldStar(ParseNode* iter)
     //
     // Call "return" with the argument passed to Generator.prototype.return,
     // which is currently in rval.value.
-    if (!ifReturnMethodIsDefined.emitIfElse())            // NEXT ITER OLDRESULT FTYPE FVALUE ITER RET
+    if (!ifReturnMethodIsDefined.emitThenElse())          // NEXT ITER OLDRESULT FTYPE FVALUE ITER RET
         return false;
     if (!emit1(JSOP_SWAP))                                // NEXT ITER OLDRESULT FTYPE FVALUE RET ITER
         return false;
@@ -8694,7 +8784,7 @@ BytecodeEmitter::emitYieldStar(ParseNode* iter)
         return false;
     if (!emitAtomOp(cx->names().done, JSOP_GETPROP))      // NEXT ITER OLDRESULT FTYPE FVALUE RESULT DONE
         return false;
-    if (!ifReturnDone.emitIfElse())                       // NEXT ITER OLDRESULT FTYPE FVALUE RESULT
+    if (!ifReturnDone.emitThenElse())                     // NEXT ITER OLDRESULT FTYPE FVALUE RESULT
         return false;
     if (!emitAtomOp(cx->names().value, JSOP_GETPROP))     // NEXT ITER OLDRESULT FTYPE FVALUE VALUE
         return false;
@@ -9453,7 +9543,7 @@ BytecodeEmitter::emitCallOrNew(ParseNode* pn, ValueUsage valueUsage /* = ValueUs
             if (!emit1(JSOP_NOT))
                 return false;
 
-            if (!ifNotOptimizable.emitIf())
+            if (!ifNotOptimizable.emitThen())
                 return false;
 
             if (!emit1(JSOP_POP))
@@ -10581,7 +10671,7 @@ BytecodeEmitter::emitClass(ParseNode* pn)
             return false;
 
         // [THEN] funProto = heritage, objProto = heritage.prototype
-        if (!ifThenElse.emitIfElse())
+        if (!ifThenElse.emitThenElse())
             return false;
         if (!emit1(JSOP_DUP))                                   // ... HERITAGE HERITAGE
             return false;

js/src/gc/Allocator.cpp

@@ -86,7 +86,7 @@ GCRuntime::tryNewNurseryObject(JSContext* cx, size_t thingSize, size_t nDynamicS
 
     MOZ_ASSERT(cx->isNurseryAllocAllowed());
     MOZ_ASSERT(!cx->isNurseryAllocSuppressed());
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
 
     JSObject* obj = cx->nursery().allocateObject(cx, thingSize, nDynamicSlots, clasp);
     if (obj)
@@ -140,7 +140,7 @@ GCRuntime::tryNewNurseryString(JSContext* cx, size_t thingSize, AllocKind kind)
     MOZ_ASSERT(cx->isNurseryAllocAllowed());
     MOZ_ASSERT(!cx->helperThread());
     MOZ_ASSERT(!cx->isNurseryAllocSuppressed());
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
 
     Cell* cell = cx->nursery().allocateString(cx->zone(), thingSize, kind);
     if (cell)
@@ -275,13 +275,13 @@ GCRuntime::checkAllocatorState(JSContext* cx, AllocKind kind)
     }
 
 #if defined(JS_GC_ZEAL) || defined(DEBUG)
-    MOZ_ASSERT_IF(cx->realm()->isAtomsRealm(),
+    MOZ_ASSERT_IF(cx->zone()->isAtomsZone(),
                   kind == AllocKind::ATOM ||
                   kind == AllocKind::FAT_INLINE_ATOM ||
                   kind == AllocKind::SYMBOL ||
                   kind == AllocKind::JITCODE ||
                   kind == AllocKind::SCOPE);
-    MOZ_ASSERT_IF(!cx->realm()->isAtomsRealm(),
+    MOZ_ASSERT_IF(!cx->zone()->isAtomsZone(),
                   kind != AllocKind::ATOM &&
                   kind != AllocKind::FAT_INLINE_ATOM);
     MOZ_ASSERT(!JS::CurrentThreadIsHeapBusy());

js/src/gc/AtomMarking.cpp

@@ -83,7 +83,7 @@ AtomMarkingRuntime::computeBitmapFromChunkMarkBits(JSRuntime* runtime, DenseBitm
     if (!bitmap.ensureSpace(allocatedWords))
         return false;
 
-    Zone* atomsZone = runtime->unsafeAtomsRealm()->zone();
+    Zone* atomsZone = runtime->unsafeAtomsZone();
     for (auto thingKind : AllAllocKinds()) {
         for (ArenaIter aiter(atomsZone, thingKind); !aiter.done(); aiter.next()) {
             Arena* arena = aiter.get();
@@ -117,7 +117,7 @@ AddBitmapToChunkMarkBits(JSRuntime* runtime, Bitmap& bitmap)
     static_assert(ArenaBitmapBits == ArenaBitmapWords * JS_BITS_PER_WORD,
                   "ArenaBitmapWords must evenly divide ArenaBitmapBits");
 
-    Zone* atomsZone = runtime->unsafeAtomsRealm()->zone();
+    Zone* atomsZone = runtime->unsafeAtomsZone();
     for (auto thingKind : AllAllocKinds()) {
         for (ArenaIter aiter(atomsZone, thingKind); !aiter.done(); aiter.next()) {
             Arena* arena = aiter.get();

js/src/gc/GC.cpp

@@ -3852,7 +3852,6 @@ Zone::sweepCompartments(FreeOp* fop, bool keepAtleastOne, bool destroyingRuntime
     while (read < end) {
         JSCompartment* comp = *read++;
         Realm* realm = JS::GetRealmForCompartment(comp);
-        MOZ_ASSERT(!realm->isAtomsRealm());
 
         /*
          * Don't delete the last compartment and realm if all the ones before
@@ -4126,7 +4125,7 @@ CompartmentCheckTracer::onChild(const JS::GCCellPtr& thing)
 {
     JSCompartment* comp = DispatchTyped(MaybeCompartmentFunctor(), thing);
     if (comp && compartment) {
-        MOZ_ASSERT(comp == compartment || runtime()->isAtomsCompartment(comp) ||
+        MOZ_ASSERT(comp == compartment ||
                    (srcKind == JS::TraceKind::Object &&
                     InCrossCompartmentMap(static_cast<JSObject*>(src), thing)));
     } else {
@@ -4223,7 +4222,7 @@ GCRuntime::prepareZonesForCollection(JS::gcreason::Reason reason, bool* isFullOu
     /* Assert that zone state is as we expect */
     for (ZonesIter zone(rt, WithAtoms); !zone.done(); zone.next()) {
         MOZ_ASSERT(!zone->isCollecting());
-        MOZ_ASSERT(!zone->compartments().empty());
+        MOZ_ASSERT_IF(!zone->isAtomsZone(), !zone->compartments().empty());
         for (auto i : AllAllocKinds())
             MOZ_ASSERT(!zone->arenas.arenaListsToSweep(i));
     }
@@ -4251,7 +4250,7 @@ GCRuntime::prepareZonesForCollection(JS::gcreason::Reason reason, bool* isFullOu
     // executable code limit.
     bool canAllocateMoreCode = jit::CanLikelyAllocateMoreExecutableMemory();
 
-    for (CompartmentsIter c(rt, WithAtoms); !c.done(); c.next()) {
+    for (CompartmentsIter c(rt); !c.done(); c.next()) {
         c->scheduledForDestruction = false;
         c->maybeAlive = false;
         for (RealmsInCompartmentIter r(c); !r.done(); r.next()) {
@@ -4478,7 +4477,7 @@ GCRuntime::markCompartments()
 
     Vector<JSCompartment*, 0, js::SystemAllocPolicy> workList;
 
-    for (CompartmentsIter comp(rt, SkipAtoms); !comp.done(); comp.next()) {
+    for (CompartmentsIter comp(rt); !comp.done(); comp.next()) {
         if (comp->maybeAlive) {
             if (!workList.append(comp))
                 return;
@@ -4895,7 +4894,7 @@ DropStringWrappers(JSRuntime* rt)
      * us to sweep the wrappers in all compartments every time we sweep a
      * compartment group.
      */
-    for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
+    for (CompartmentsIter c(rt); !c.done(); c.next()) {
         for (JSCompartment::StringWrapperEnum e(c); !e.empty(); e.popFront()) {
             MOZ_ASSERT(e.front().key().is<JSString*>());
             e.removeFront();
@@ -5137,7 +5136,7 @@ static void
 AssertNoWrappersInGrayList(JSRuntime* rt)
 {
 #ifdef DEBUG
-    for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
+    for (CompartmentsIter c(rt); !c.done(); c.next()) {
         MOZ_ASSERT(!c->gcIncomingGrayPointers);
         for (JSCompartment::NonStringWrapperEnum e(c); !e.empty(); e.popFront())
             AssertNotOnGrayList(&e.front().value().unbarrieredGet().toObject());
@@ -5412,7 +5411,7 @@ UpdateAtomsBitmap(GCParallelTask* task)
     // For convenience sweep these tables non-incrementally as part of bitmap
     // sweeping; they are likely to be much smaller than the main atoms table.
     runtime->unsafeSymbolRegistry().sweep();
-    for (RealmsIter realm(runtime, SkipAtoms); !realm.done(); realm.next())
+    for (RealmsIter realm(runtime); !realm.done(); realm.next())
         realm->sweepVarNames();
 }
 
@@ -6888,7 +6887,7 @@ GCRuntime::resetIncrementalGC(gc::AbortReason reason, AutoTraceSession& session)
       case State::Sweep: {
         marker.reset();
 
-        for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next())
+        for (CompartmentsIter c(rt); !c.done(); c.next())
             c->scheduledForDestruction = false;
 
         /* Finish sweeping the current sweep group, then abort. */
@@ -7552,7 +7551,7 @@ GCRuntime::maybeDoCycleCollection()
 
     size_t realmsTotal = 0;
     size_t realmsGray = 0;
-    for (RealmsIter realm(rt, SkipAtoms); !realm.done(); realm.next()) {
+    for (RealmsIter realm(rt); !realm.done(); realm.next()) {
         ++realmsTotal;
         GlobalObject* global = realm->unsafeUnbarrieredMaybeGlobal();
         if (global && global->isMarkedGray())
@@ -7602,7 +7601,7 @@ GCRuntime::shouldRepeatForDeadZone(JS::gcreason::Reason reason)
     if (!isIncremental)
         return false;
 
-    for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
+    for (CompartmentsIter c(rt); !c.done(); c.next()) {
         if (c->scheduledForDestruction)
             return true;
     }
@@ -7961,7 +7960,7 @@ js::NewRealm(JSContext* cx, JSPrincipals* principals, const JS::RealmOptions& op
         return nullptr;
 
     // Set up the principals.
-    JS_SetCompartmentPrincipals(JS::GetCompartmentForRealm(realm), principals);
+    JS::SetRealmPrincipals(realm, principals);
 
     JSCompartment* comp = realm->compartment();
     if (!comp->realms().append(realm)) {
@@ -8488,7 +8487,7 @@ js::gc::CheckHashTablesAfterMovingGC(JSRuntime* rt)
         }
     }
 
-    for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
+    for (CompartmentsIter c(rt); !c.done(); c.next()) {
         c->checkWrapperMapAfterMovingGC();
 
         for (RealmsInCompartmentIter r(c); !r.done(); r.next()) {

js/src/gc/Nursery.cpp

@@ -1029,7 +1029,7 @@ js::Nursery::sweep(JSTracer* trc)
     }
     cellsWithUid_.clear();
 
-    for (CompartmentsIter c(runtime(), SkipAtoms); !c.done(); c.next())
+    for (CompartmentsIter c(runtime()); !c.done(); c.next())
         c->sweepAfterMinorGC(trc);
 
     sweepDictionaryModeObjects();

js/src/gc/PrivateIterators-inl.h

@@ -67,7 +67,7 @@ class GCZonesIter
         MOZ_ASSERT_IF(rt->gc.atomsZone->isCollectingFromAnyThread(),
                       !rt->hasHelperThreadZones());
 
-        if (!zone->isCollectingFromAnyThread())
+        if (!done() && !zone->isCollectingFromAnyThread())
             next();
     }
 
@@ -95,11 +95,22 @@ using GCRealmsIter = CompartmentsOrRealmsIterT<GCZonesIter, RealmsInZoneIter>;
 /* Iterates over all zones in the current sweep group. */
 class SweepGroupZonesIter {
     JS::Zone* current;
+    ZoneSelector selector;
 
   public:
-    explicit SweepGroupZonesIter(JSRuntime* rt) {
+    explicit SweepGroupZonesIter(JSRuntime* rt, ZoneSelector selector = WithAtoms)
+      : selector(selector)
+    {
         MOZ_ASSERT(CurrentThreadIsPerformingGC());
         current = rt->gc.getCurrentSweepGroup();
+        maybeSkipAtomsZone();
+    }
+
+    void maybeSkipAtomsZone() {
+        if (selector == SkipAtoms && current && current->isAtomsZone()) {
+            current = current->nextNodeInGroup();
+            MOZ_ASSERT_IF(current, !current->isAtomsZone());
+        }
     }
 
     bool done() const { return !current; }
@@ -107,6 +118,7 @@ class SweepGroupZonesIter {
     void next() {
         MOZ_ASSERT(!done());
         current = current->nextNodeInGroup();
+        maybeSkipAtomsZone();
     }
 
     JS::Zone* get() const {

js/src/gc/PublicIterators.cpp

@@ -141,7 +141,7 @@ JS_IterateCompartments(JSContext* cx, void* data,
 {
     AutoTraceSession session(cx->runtime());
 
-    for (CompartmentsIter c(cx->runtime(), WithAtoms); !c.done(); c.next())
+    for (CompartmentsIter c(cx->runtime()); !c.done(); c.next())
         (*compartmentCallback)(cx, data, c);
 }
 
@@ -151,7 +151,7 @@ JS::IterateRealms(JSContext* cx, void* data, JS::IterateRealmCallback realmCallb
     AutoTraceSession session(cx->runtime());
 
     Rooted<Realm*> realm(cx);
-    for (RealmsIter r(cx->runtime(), WithAtoms); !r.done(); r.next()) {
+    for (RealmsIter r(cx->runtime()); !r.done(); r.next()) {
         realm = r;
         (*realmCallback)(cx, data, realm);
     }

js/src/gc/PublicIterators.h

@@ -193,14 +193,7 @@ class CompartmentsOrRealmsIterT
 
   public:
     explicit CompartmentsOrRealmsIterT(JSRuntime* rt)
-      : iterMarker(&rt->gc), zone(rt)
-    {
-        if (!zone.done())
-            inner.emplace(zone);
-    }
-
-    CompartmentsOrRealmsIterT(JSRuntime* rt, ZoneSelector selector)
-      : iterMarker(&rt->gc), zone(rt, selector)
+      : iterMarker(&rt->gc), zone(rt, SkipAtoms)
     {
         if (!zone.done())
             inner.emplace(zone);

js/src/gc/RootMarking.cpp

@@ -369,7 +369,7 @@ js::gc::GCRuntime::traceRuntimeCommon(JSTracer* trc, TraceOrMarkRuntime traceOrM
 
     // Trace all realm roots, but not the realm itself; it is traced via the
     // parent pointer if traceRoots actually traces anything.
-    for (RealmsIter r(rt, SkipAtoms); !r.done(); r.next())
+    for (RealmsIter r(rt); !r.done(); r.next())
         r->traceRoots(trc, traceOrMark);
 
     // Trace helper thread roots.
@@ -427,7 +427,7 @@ js::gc::GCRuntime::finishRoots()
 
     rt->finishSelfHosting();
 
-    for (RealmsIter r(rt, SkipAtoms); !r.done(); r.next())
+    for (RealmsIter r(rt); !r.done(); r.next())
         r->finishRoots();
 
 #ifdef DEBUG

js/src/gc/Tracer.cpp

@@ -163,7 +163,7 @@ struct TraceIncomingFunctor {
 JS_PUBLIC_API(void)
 JS::TraceIncomingCCWs(JSTracer* trc, const JS::CompartmentSet& compartments)
 {
-    for (js::CompartmentsIter comp(trc->runtime(), SkipAtoms); !comp.done(); comp.next()) {
+    for (js::CompartmentsIter comp(trc->runtime()); !comp.done(); comp.next()) {
         if (compartments.has(comp))
             continue;
 

js/src/jit-test/tests/gc/bug-1464872.js

@@ -0,0 +1,14 @@
+var g = newGlobal();
+var dbg = Debugger(g);
+dbg.onEnterFrame = function(frame) {};
+
+var g2 = newGlobal();
+g2[g] = g;
+g2.evaluate("grayRoot()")
+g2 = undefined;
+
+g = undefined;
+dbg = undefined;
+
+gc();
+startgc(100000);

js/src/jit/BaselineDebugModeOSR.cpp

@@ -1043,7 +1043,7 @@ JitRuntime::getBaselineDebugModeOSRHandler(JSContext* cx)
 {
     if (!baselineDebugModeOSRHandler_) {
         AutoLockForExclusiveAccess lock(cx);
-        AutoAtomsRealm ar(cx, lock);
+        AutoAtomsZone az(cx, lock);
         uint32_t offset;
         if (JitCode* code = generateBaselineDebugModeOSRHandler(cx, &offset)) {
             baselineDebugModeOSRHandler_ = code;

js/src/jit/Ion.cpp

@@ -108,6 +108,7 @@ JitContext::JitContext(CompileRuntime* rt, CompileRealm* realm, TempAllocator* t
     temp(temp),
     runtime(rt),
     realm(realm),
+    zone(realm ? realm->zone() : nullptr),
     prev_(CurrentJitContext()),
     assemblerCount_(0)
 {
@@ -119,6 +120,7 @@ JitContext::JitContext(JSContext* cx, TempAllocator* temp)
     temp(temp),
     runtime(CompileRuntime::get(cx->runtime())),
     realm(CompileRealm::get(cx->realm())),
+    zone(CompileZone::get(cx->zone())),
     prev_(CurrentJitContext()),
     assemblerCount_(0)
 {
@@ -211,13 +213,10 @@ JitRuntime::startTrampolineCode(MacroAssembler& masm)
 bool
 JitRuntime::initialize(JSContext* cx, AutoLockForExclusiveAccess& lock)
 {
-    AutoAtomsRealm ar(cx, lock);
+    AutoAtomsZone az(cx, lock);
 
     JitContext jctx(cx, nullptr);
 
-    if (!cx->realm()->ensureJitRealmExists(cx))
-        return false;
-
     functionWrappers_ = cx->new_<VMWrapperMap>(cx);
     if (!functionWrappers_ || !functionWrappers_->init())
         return false;
@@ -339,7 +338,7 @@ JitRuntime::debugTrapHandler(JSContext* cx)
         // JitRuntime code stubs are shared across compartments and have to
         // be allocated in the atoms zone.
         AutoLockForExclusiveAccess lock(cx);
-        AutoAtomsRealm ar(cx, lock);
+        AutoAtomsZone az(cx, lock);
         debugTrapHandler_ = generateDebugTrapHandler(cx);
     }
     return debugTrapHandler_;
@@ -592,7 +591,7 @@ JitRuntime::Trace(JSTracer* trc, AutoLockForExclusiveAccess& lock)
     if (trc->runtime()->atomsAreFinished())
         return;
 
-    Zone* zone = trc->runtime()->atomsRealm(lock)->zone();
+    Zone* zone = trc->runtime()->atomsZone(lock);
     for (auto i = zone->cellIter<JitCode>(); !i.done(); i.next()) {
         JitCode* code = i;
         TraceRoot(trc, &code, "wrapper");

js/src/jit/Ion.h

@@ -72,6 +72,7 @@ class JitContext
     // during compilation.
     CompileRuntime* runtime;
     CompileRealm* realm;
+    CompileZone* zone;
 
     int getNextAssemblerId() {
         return assemblerCount_++;

js/src/jit/JSJitFrameIter.h

@@ -346,9 +346,7 @@ class RInstructionResults
 
     MOZ_MUST_USE bool init(JSContext* cx, uint32_t numResults);
     bool isInitialized() const;
-#ifdef DEBUG
     size_t length() const;
-#endif
 
     JitFrameLayout* frame() const;
 

js/src/jit/JitFrames.cpp

@@ -1494,13 +1494,11 @@ RInstructionResults::isInitialized() const
     return initialized_;
 }
 
-#ifdef DEBUG
 size_t
 RInstructionResults::length() const
 {
     return results_->length();
 }
-#endif
 
 JitFrameLayout*
 RInstructionResults::frame() const
@@ -1953,7 +1951,7 @@ SnapshotIterator::initInstructionResults(MaybeReadFallback& fallback)
     }
 
     MOZ_ASSERT(results->isInitialized());
-    MOZ_ASSERT(results->length() == recover_.numInstructions() - 1);
+    MOZ_RELEASE_ASSERT(results->length() == recover_.numInstructions() - 1);
     instructionResults_ = results;
     return true;
 }

js/src/jit/shared/Assembler-shared.h

@@ -157,8 +157,8 @@ struct Imm64
 static inline bool
 IsCompilingWasm()
 {
-    // wasm compilation pushes a JitContext with a null Realm.
-    return GetJitContext()->realm == nullptr;
+    // wasm compilation pushes a JitContext with a null Zone.
+    return GetJitContext()->zone == nullptr;
 }
 #endif
 

js/src/jsapi.cpp

@@ -797,7 +797,7 @@ ReleaseAssertObjectHasNoWrappers(JSContext* cx, HandleObject target)
 {
     RootedValue origv(cx, ObjectValue(*target));
 
-    for (CompartmentsIter c(cx->runtime(), SkipAtoms); !c.done(); c.next()) {
+    for (CompartmentsIter c(cx->runtime()); !c.done(); c.next()) {
         if (c->lookupWrapper(origv))
             MOZ_CRASH("wrapper found for target object");
     }
@@ -954,7 +954,7 @@ JS_RefreshCrossCompartmentWrappers(JSContext* cx, HandleObject obj)
 JS_PUBLIC_API(bool)
 JS_InitStandardClasses(JSContext* cx, HandleObject obj)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -1974,7 +1974,7 @@ JS_FireOnNewGlobalObject(JSContext* cx, JS::HandleObject global)
 JS_PUBLIC_API(JSObject*)
 JS_NewObject(JSContext* cx, const JSClass* jsclasp)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -1991,7 +1991,7 @@ JS_NewObject(JSContext* cx, const JSClass* jsclasp)
 JS_PUBLIC_API(JSObject*)
 JS_NewObjectWithGivenProto(JSContext* cx, const JSClass* jsclasp, HandleObject proto)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, proto);
@@ -2009,7 +2009,7 @@ JS_NewObjectWithGivenProto(JSContext* cx, const JSClass* jsclasp, HandleObject p
 JS_PUBLIC_API(JSObject*)
 JS_NewPlainObject(JSContext* cx)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -2909,7 +2909,7 @@ JS_PUBLIC_API(bool)
 JS_CallFunctionValue(JSContext* cx, HandleObject obj, HandleValue fval, const HandleValueArray& args,
                      MutableHandleValue rval)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj, fval, args);
@@ -2926,7 +2926,7 @@ JS_PUBLIC_API(bool)
 JS_CallFunction(JSContext* cx, HandleObject obj, HandleFunction fun, const HandleValueArray& args,
                 MutableHandleValue rval)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj, fun, args);
@@ -2944,7 +2944,7 @@ JS_PUBLIC_API(bool)
 JS_CallFunctionName(JSContext* cx, HandleObject obj, const char* name, const HandleValueArray& args,
                     MutableHandleValue rval)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj, args);
@@ -3378,7 +3378,7 @@ JS_SetReservedSlot(JSObject* obj, uint32_t index, const Value& value)
 JS_PUBLIC_API(JSObject*)
 JS_NewArrayObject(JSContext* cx, const JS::HandleValueArray& contents)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -3389,7 +3389,7 @@ JS_NewArrayObject(JSContext* cx, const JS::HandleValueArray& contents)
 JS_PUBLIC_API(JSObject*)
 JS_NewArrayObject(JSContext* cx, size_t length)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -3512,7 +3512,7 @@ JS_PUBLIC_API(JSFunction*)
 JS_NewFunction(JSContext* cx, JSNative native, unsigned nargs, unsigned flags,
                const char* name)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
 
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
@@ -3532,7 +3532,7 @@ JS_NewFunction(JSContext* cx, JSNative native, unsigned nargs, unsigned flags,
 JS_PUBLIC_API(JSFunction*)
 JS::GetSelfHostedFunction(JSContext* cx, const char* selfHostedName, HandleId id, unsigned nargs)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, id);
@@ -3788,7 +3788,7 @@ JS_IsConstructor(JSFunction* fun)
 JS_PUBLIC_API(bool)
 JS_DefineFunctions(JSContext* cx, HandleObject obj, const JSFunctionSpec* fs)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
@@ -3800,7 +3800,7 @@ JS_PUBLIC_API(JSFunction*)
 JS_DefineFunction(JSContext* cx, HandleObject obj, const char* name, JSNative call,
                   unsigned nargs, unsigned attrs)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
@@ -3816,7 +3816,7 @@ JS_DefineUCFunction(JSContext* cx, HandleObject obj,
                     const char16_t* name, size_t namelen, JSNative call,
                     unsigned nargs, unsigned attrs)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
@@ -3831,7 +3831,7 @@ extern JS_PUBLIC_API(JSFunction*)
 JS_DefineFunctionById(JSContext* cx, HandleObject obj, HandleId id, JSNative call,
                       unsigned nargs, unsigned attrs)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj, id);
@@ -4082,7 +4082,7 @@ Compile(JSContext* cx, const ReadOnlyCompileOptions& options,
 {
     ScopeKind scopeKind = options.nonSyntacticScope ? ScopeKind::NonSyntactic : ScopeKind::Global;
 
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -4223,7 +4223,7 @@ JSScript*
 JS::DecodeBinAST(JSContext* cx, const ReadOnlyCompileOptions& options,
                  const uint8_t* buf, size_t length)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -4547,7 +4547,7 @@ CompileFunction(JSContext* cx, const ReadOnlyCompileOptions& optionsArg,
                 HandleObject enclosingEnv, HandleScope enclosingScope,
                 MutableHandleFunction fun)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, enclosingEnv);
@@ -4716,7 +4716,7 @@ JS::ExposeScriptToDebugger(JSContext* cx, HandleScript script)
 JS_PUBLIC_API(JSString*)
 JS_DecompileScript(JSContext* cx, HandleScript script)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
 
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
@@ -4734,7 +4734,7 @@ JS_DecompileScript(JSContext* cx, HandleScript script)
 JS_PUBLIC_API(JSString*)
 JS_DecompileFunction(JSContext* cx, HandleFunction fun)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, fun);
@@ -4744,7 +4744,7 @@ JS_DecompileFunction(JSContext* cx, HandleFunction fun)
 MOZ_NEVER_INLINE static bool
 ExecuteScript(JSContext* cx, HandleObject scope, HandleScript script, Value* rval)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, scope, script);
@@ -4838,7 +4838,7 @@ Evaluate(JSContext* cx, ScopeKind scopeKind, HandleObject env,
          SourceBufferHolder& srcBuf, MutableHandleValue rval)
 {
     CompileOptions options(cx, optionsArg);
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, env);
@@ -4979,7 +4979,7 @@ JS_PUBLIC_API(bool)
 JS::CompileModule(JSContext* cx, const ReadOnlyCompileOptions& options,
                   SourceBufferHolder& srcBuf, JS::MutableHandleObject module)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -5137,7 +5137,7 @@ JS::SetPromiseRejectionTrackerCallback(JSContext* cx, JSPromiseRejectionTrackerC
 JS_PUBLIC_API(JSObject*)
 JS::NewPromiseObject(JSContext* cx, HandleObject executor, HandleObject proto /* = nullptr */)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, executor, proto);
@@ -5391,7 +5391,7 @@ JS::NewReadableDefaultStreamObject(JSContext* cx,
                                    double highWaterMark /* = 1 */,
                                    JS::HandleObject proto /* = nullptr */)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -5413,7 +5413,7 @@ JS::NewReadableByteStreamObject(JSContext* cx,
                                 double highWaterMark /* = 1 */,
                                 JS::HandleObject proto /* = nullptr */)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -5472,7 +5472,7 @@ JS::NewReadableExternalSourceStreamObject(JSContext* cx, void* underlyingSource,
                                           uint8_t flags /* = 0 */,
                                           HandleObject proto /* = nullptr */)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     AssertHeapIsIdle();
     CHECK_REQUEST(cx);
 
@@ -7627,9 +7627,8 @@ GetScriptedCallerGlobal(JSContext* cx)
 
     GlobalObject* global = realm->maybeGlobal();
 
-    // No one should be running code in the atoms realm or running code in a
-    // realm without any live objects, so there should definitely be a live
-    // global.
+    // No one should be running code in a realm without any live objects, so
+    // there should definitely be a live global.
     MOZ_ASSERT(global);
 
     return global;

js/src/jsfriendapi.cpp

@@ -162,11 +162,16 @@ JS_GetCompartmentPrincipals(JSCompartment* compartment)
     return realm->principals();
 }
 
+JS_FRIEND_API(JSPrincipals*)
+JS::GetRealmPrincipals(JS::Realm* realm)
+{
+    return realm->principals();
+}
+
 JS_FRIEND_API(void)
-JS_SetCompartmentPrincipals(JSCompartment* compartment, JSPrincipals* principals)
+JS::SetRealmPrincipals(JS::Realm* realm, JSPrincipals* principals)
 {
     // Short circuit if there's no change.
-    Realm* realm = JS::GetRealmForCompartment(compartment);
     if (principals == realm->principals())
         return;
 
@@ -246,7 +251,7 @@ DefineHelpProperty(JSContext* cx, HandleObject obj, const char* prop, const char
 JS_FRIEND_API(bool)
 JS_DefineFunctionsWithHelp(JSContext* cx, HandleObject obj, const JSFunctionSpecWithHelp* fs)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
 
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
@@ -351,12 +356,6 @@ js::IsSystemZone(Zone* zone)
     return zone->isSystem;
 }
 
-JS_FRIEND_API(bool)
-js::IsAtomsRealm(JS::Realm* realm)
-{
-    return realm->isAtomsRealm();
-}
-
 JS_FRIEND_API(bool)
 js::IsAtomsZone(JS::Zone* zone)
 {
@@ -433,7 +432,7 @@ js::DefineFunctionWithReserved(JSContext* cx, JSObject* objArg, const char* name
                                unsigned nargs, unsigned attrs)
 {
     RootedObject obj(cx, objArg);
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, obj);
     JSAtom* atom = Atomize(cx, name, strlen(name));
@@ -447,7 +446,7 @@ JS_FRIEND_API(JSFunction*)
 js::NewFunctionWithReserved(JSContext* cx, JSNative native, unsigned nargs, unsigned flags,
                             const char* name)
 {
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
 
     CHECK_REQUEST(cx);
 
@@ -468,7 +467,7 @@ js::NewFunctionByIdWithReserved(JSContext* cx, JSNative native, unsigned nargs,
                                 jsid id)
 {
     MOZ_ASSERT(JSID_IS_STRING(id));
-    MOZ_ASSERT(!cx->realm()->isAtomsRealm());
+    MOZ_ASSERT(!cx->zone()->isAtomsZone());
     CHECK_REQUEST(cx);
     assertSameCompartment(cx, id);
 
@@ -1275,6 +1274,9 @@ JS::NotifyGCRootsRemoved(JSContext* cx)
 JS_FRIEND_API(JS::Realm*)
 js::GetAnyRealmInZone(JS::Zone* zone)
 {
+    if (zone->isAtomsZone())
+        return nullptr;
+
     RealmsInZoneIter realm(zone);
     MOZ_ASSERT(!realm.done());
     return realm.get();
@@ -1543,8 +1545,9 @@ js::EnableAccessValidation(JSContext* cx, bool enabled)
 }
 
 JS_FRIEND_API(void)
-js::SetCompartmentValidAccessPtr(JSContext* cx, JS::HandleObject global, bool* accessp)
+js::SetRealmValidAccessPtr(JSContext* cx, JS::HandleObject global, bool* accessp)
 {
+    MOZ_ASSERT(global->is<GlobalObject>());
     global->realm()->setValidAccessPtr(accessp);
 }
 

js/src/jsfriendapi.h

@@ -190,9 +190,6 @@ JS_GetIsSecureContext(JSCompartment* compartment);
 extern JS_FRIEND_API(JSPrincipals*)
 JS_GetCompartmentPrincipals(JSCompartment* compartment);
 
-extern JS_FRIEND_API(void)
-JS_SetCompartmentPrincipals(JSCompartment* compartment, JSPrincipals* principals);
-
 extern JS_FRIEND_API(JSPrincipals*)
 JS_GetScriptPrincipals(JSScript* script);
 
@@ -325,6 +322,12 @@ ForceLexicalInitialization(JSContext *cx, HandleObject obj);
 extern JS_FRIEND_API(int)
 IsGCPoisoning();
 
+extern JS_FRIEND_API(JSPrincipals*)
+GetRealmPrincipals(JS::Realm* realm);
+
+extern JS_FRIEND_API(void)
+SetRealmPrincipals(JS::Realm* realm, JSPrincipals* principals);
+
 } // namespace JS
 
 /**
@@ -483,9 +486,6 @@ IsSystemCompartment(JSCompartment* comp);
 extern JS_FRIEND_API(bool)
 IsSystemZone(JS::Zone* zone);
 
-extern JS_FRIEND_API(bool)
-IsAtomsRealm(JS::Realm* realm);
-
 extern JS_FRIEND_API(bool)
 IsAtomsZone(JS::Zone* zone);
 
@@ -553,6 +553,7 @@ extern JS_FRIEND_API(size_t)
 SizeOfDataIfCDataObject(mozilla::MallocSizeOf mallocSizeOf, JSObject* obj);
 #endif
 
+// Note: this returns nullptr iff |zone| is the atoms zone.
 extern JS_FRIEND_API(JS::Realm*)
 GetAnyRealmInZone(JS::Zone* zone);
 
@@ -566,8 +567,8 @@ namespace shadow {
 
 struct ObjectGroup {
     const Class* clasp;
-    JSObject*   proto;
-    JSCompartment* compartment;
+    JSObject* proto;
+    JS::Realm* realm;
 };
 
 struct BaseShape {
@@ -670,10 +671,23 @@ InheritanceProtoKeyForStandardClass(JSProtoKey key)
 JS_FRIEND_API(bool)
 IsFunctionObject(JSObject* obj);
 
+JS_FRIEND_API(bool)
+IsCrossCompartmentWrapper(JSObject* obj);
+
 static MOZ_ALWAYS_INLINE JSCompartment*
 GetObjectCompartment(JSObject* obj)
 {
-    return reinterpret_cast<shadow::Object*>(obj)->group->compartment;
+    JS::Realm* realm = reinterpret_cast<shadow::Object*>(obj)->group->realm;
+    return JS::GetCompartmentForRealm(realm);
+}
+
+// CrossCompartmentWrappers are shared by all realms within the compartment, so
+// getting a wrapper's realm usually doesn't make sense.
+static MOZ_ALWAYS_INLINE JS::Realm*
+GetNonCCWObjectRealm(JSObject* obj)
+{
+    MOZ_ASSERT(!js::IsCrossCompartmentWrapper(obj));
+    return reinterpret_cast<shadow::Object*>(obj)->group->realm;
 }
 
 JS_FRIEND_API(JSObject*)
@@ -3093,9 +3107,9 @@ class MOZ_STACK_CLASS JS_FRIEND_API(AutoAssertNoContentJS)
 };
 
 // Turn on assertions so that we assert that
-//     !comp->validAccessPtr || *comp->validAccessPtr
-// is true for every |comp| that we run JS code in. The compartment's validAccessPtr
-// is set via SetCompartmentValidAccessPtr.
+//     !realm->validAccessPtr || *realm->validAccessPtr
+// is true for every |realm| that we run JS code in. The realm's validAccessPtr
+// is set via SetRealmValidAccessPtr.
 extern JS_FRIEND_API(void)
 EnableAccessValidation(JSContext* cx, bool enabled);
 
@@ -3104,7 +3118,7 @@ EnableAccessValidation(JSContext* cx, bool enabled);
 // threads that are allowed to run code on |global|, so all changes to *accessp
 // should be made from whichever thread owns |global| at a given time.
 extern JS_FRIEND_API(void)
-SetCompartmentValidAccessPtr(JSContext* cx, JS::HandleObject global, bool* accessp);
+SetRealmValidAccessPtr(JSContext* cx, JS::HandleObject global, bool* accessp);
 
 // Returns true if the system zone is available (i.e., if no cooperative contexts
 // are using it now).

js/src/jspubtd.h

@@ -85,6 +85,7 @@ typedef JSConstScalarSpec<int32_t> JSConstIntegerSpec;
 
 namespace js {
 
+inline JS::Realm* GetContextRealm(const JSContext* cx);
 inline JSCompartment* GetContextCompartment(const JSContext* cx);
 inline JS::Zone* GetContextZone(const JSContext* cx);