Add support for `elemhide` (through `specifichide`)

Related documentation: - https://help.eyeo.com/en/adblockplus/how-to-write-filters#element-hiding Related feedback/discussion: - https://www.reddit.com/r/uBlockOrigin/comments/d6vxzj/ The `elemhide` filter option as per ABP semantic is now supported. Previously uBO would consider `elemhide` to be an alias of `generichide`. The support of `elemhide` is through the convenient conversion of `elemhide` option into existing `generichide` option and new `specifichide` option. The purpose of the new `specifichide` filter option is to disable all specific cosmetic filters, i.e. those who target a specific site. Additionally, for convenience purpose, the filter options `generichide`, `specifichide` and `elemhide` can be aliased using the shorter forms `ghide`, `shide` and `ehide` respectively.
2019-09-21 11:30:38 -04:00 · 2019-09-21 11:30:38 -04:00 · 23c4c80136
parent 6033ebf0d0
commit 23c4c80136
9 changed files with 269 additions and 141 deletions
--- a/src/js/background.js
+++ b/src/js/background.js
@ -33,7 +33,7 @@ if ( vAPI.webextFlavor === undefined ) {

 /******************************************************************************/

-const µBlock = (function() { // jshint ignore:line
+const µBlock = (( ) => { // jshint ignore:line

    const hiddenSettingsDefault = {
        allowGenericProceduralFilters: false,
@ -84,7 +84,7 @@ const µBlock = (function() { // jshint ignore:line
            requestLogMaxEntries: 1000,
            showIconBadge: true,
            tooltipsDisabled: false,
-            webrtcIPAddressHidden: false
+            webrtcIPAddressHidden: false,
        },

        hiddenSettingsDefault: hiddenSettingsDefault,
@ -133,22 +133,22 @@ const µBlock = (function() { // jshint ignore:line

        localSettings: {
            blockedRequestCount: 0,
-            allowedRequestCount: 0
+            allowedRequestCount: 0,
        },
        localSettingsLastModified: 0,
        localSettingsLastSaved: 0,

        // Read-only
        systemSettings: {
-            compiledMagic: 18,  // Increase when compiled format changes
-            selfieMagic: 18     // Increase when selfie format changes
+            compiledMagic: 19,  // Increase when compiled format changes
+            selfieMagic: 19,    // Increase when selfie format changes
        },

        restoreBackupSettings: {
            lastRestoreFile: '',
            lastRestoreTime: 0,
            lastBackupFile: '',
-            lastBackupTime: 0
+            lastBackupTime: 0,
        },

        commandShortcuts: new Map(),
--- a/src/js/cosmetic-filtering.js
+++ b/src/js/cosmetic-filtering.js
@ -23,7 +23,7 @@

 /******************************************************************************/

-µBlock.cosmeticFilteringEngine = (function(){
+µBlock.cosmeticFilteringEngine = (( ) => {

 /******************************************************************************/

@ -238,10 +238,12 @@ const FilterContainer = function() {
    // is to prevent repeated allocation/deallocation overheads -- the
    // constructors/destructors of javascript Set/Map is assumed to be costlier
    // than just calling clear() on these.
-    this.setRegister0 = new Set();
-    this.setRegister1 = new Set();
-    this.setRegister2 = new Set();
-    this.mapRegister0 = new Map();
+    this.simpleSet$ = new Set();
+    this.complexSet$ = new Set();
+    this.specificSet$ = new Set();
+    this.exceptionSet$ = new Set();
+    this.proceduralSet$ = new Set();
+    this.dummySet$ = new Set();

    this.reset();
 };
@ -830,11 +832,11 @@ FilterContainer.prototype.retrieveGenericSelectors = function(request) {

    //console.time('cosmeticFilteringEngine.retrieveGenericSelectors');

-    const simpleSelectors = this.setRegister0;
-    const complexSelectors = this.setRegister1;
+    const simpleSelectors = this.simpleSet$;
+    const complexSelectors = this.complexSet$;

    const cacheEntry = this.selectorCache.get(request.hostname);
-    const previousHits = cacheEntry && cacheEntry.cosmetic || this.setRegister2;
+    const previousHits = cacheEntry && cacheEntry.cosmetic || this.dummySet$;

    for ( const type in this.lowlyGeneric ) {
        const entry = this.lowlyGeneric[type];
@ -891,6 +893,10 @@ FilterContainer.prototype.retrieveGenericSelectors = function(request) {
        excepted,
    };

+    // Important: always clear used registers before leaving.
+    simpleSelectors.clear();
+    complexSelectors.clear();
+
    // Cache and inject (if user stylesheets supported) looked-up low generic
    // cosmetic filters.
    if (
@ -931,10 +937,6 @@ FilterContainer.prototype.retrieveGenericSelectors = function(request) {
        });
    }

-    // Important: always clear used registers before leaving.
-    this.setRegister0.clear();
-    this.setRegister1.clear();
-
    //console.timeEnd('cosmeticFilteringEngine.retrieveGenericSelectors');

    return out;
@ -946,8 +948,6 @@ FilterContainer.prototype.retrieveSpecificSelectors = function(
    request,
    options
 ) {
-    //console.time('cosmeticFilteringEngine.retrieveSpecificSelectors');
-
    const hostname = request.hostname;
    const cacheEntry = this.selectorCache.get(hostname);

@ -976,7 +976,11 @@ FilterContainer.prototype.retrieveSpecificSelectors = function(
    };

    if ( options.noCosmeticFiltering !== true ) {
-        const specificSet = this.setRegister1;
+        const specificSet = this.specificSet$;
+        const proceduralSet = this.proceduralSet$;
+        const exceptionSet = this.exceptionSet$;
+        const dummySet = this.dummySet$;
+
        // Cached cosmetic filters: these are always declarative.
        if ( cacheEntry !== undefined ) {
            cacheEntry.retrieve('cosmetic', specificSet);
@ -986,17 +990,30 @@ FilterContainer.prototype.retrieveSpecificSelectors = function(
            }
        }

-        const exceptionSet = this.setRegister0;
-        const proceduralSet = this.setRegister2;
-
+        // Retrieve filters with a non-empty hostname
        this.specificFilters.retrieve(
            hostname,
-            [ specificSet, exceptionSet, proceduralSet, exceptionSet ]
+            options.noSpecificCosmeticFiltering !== true
+                ? [ specificSet, exceptionSet, proceduralSet, exceptionSet ]
+                : [ dummySet, exceptionSet, dummySet, exceptionSet ],
+            1
        );
+        // Retrieve filters with an empty hostname
+        this.specificFilters.retrieve(
+            hostname,
+            options.noGenericCosmeticFiltering !== true
+                ? [ specificSet, exceptionSet, proceduralSet, exceptionSet ]
+                : [ dummySet, exceptionSet, dummySet, exceptionSet ],
+            2
+        );
+        // Retrieve filters with a non-empty entity
        if ( request.entity !== '' ) {
            this.specificFilters.retrieve(
                `${hostname.slice(0, -request.domain.length)}${request.entity}`,
-                [ specificSet, exceptionSet, proceduralSet, exceptionSet ]
+                options.noSpecificCosmeticFiltering !== true
+                    ? [ specificSet, exceptionSet, proceduralSet, exceptionSet ]
+                    : [ dummySet, exceptionSet, dummySet, exceptionSet ],
+                1
            );
        }

@ -1060,9 +1077,10 @@ FilterContainer.prototype.retrieveSpecificSelectors = function(
        }

        // Important: always clear used registers before leaving.
-        this.setRegister0.clear();
-        this.setRegister1.clear();
-        this.setRegister2.clear();
+        specificSet.clear();
+        proceduralSet.clear();
+        exceptionSet.clear();
+        dummySet.clear();
    }

    // CSS selectors for collapsible blocked elements
@ -1115,8 +1133,6 @@ FilterContainer.prototype.retrieveSpecificSelectors = function(
        }
    }

-    //console.timeEnd('cosmeticFilteringEngine.retrieveSpecificSelectors');
-
    return out;
 };

--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@ -500,6 +500,98 @@ vAPI.messaging.listen({

 const µb = µBlock;

+const retrieveContentScriptParameters = function(senderDetails, request) {
+    const { url, tabId, frameId } = senderDetails;
+    if ( url === undefined || tabId === undefined || frameId === undefined ) {
+        return;
+    }
+    if ( request.url !== url ) { return; }
+    const pageStore = µb.pageStoreFromTabId(tabId);
+    if ( pageStore === null || pageStore.getNetFilteringSwitch() === false ) {
+        return;
+    }
+
+    const noCosmeticFiltering = pageStore.noCosmeticFiltering === true;
+
+    const response = {
+        collapseBlocked: µb.userSettings.collapseBlocked,
+        noCosmeticFiltering,
+        noGenericCosmeticFiltering: noCosmeticFiltering,
+        noSpecificCosmeticFiltering: noCosmeticFiltering,
+    };
+
+    // https://github.com/uBlockOrigin/uAssets/issues/5704
+    //   `generichide` must be evaluated in the frame context.
+    if ( noCosmeticFiltering === false ) {
+        const genericHide =
+            µb.staticNetFilteringEngine.matchStringElementHide(
+                'generic',
+                request.url
+            );
+        response.noGenericCosmeticFiltering = genericHide === 2;
+        if ( genericHide !== 0 && µb.logger.enabled ) {
+            µBlock.filteringContext
+                .duplicate()
+                .fromTabId(tabId)
+                .setURL(request.url)
+                .setRealm('network')
+                .setType('generichide')
+                .setFilter(µb.staticNetFilteringEngine.toLogData())
+                .toLogger();
+        }
+    }
+
+    request.tabId = tabId;
+    request.frameId = frameId;
+    request.hostname = µb.URI.hostnameFromURI(request.url);
+    request.domain = µb.URI.domainFromHostname(request.hostname);
+    request.entity = µb.URI.entityFromDomain(request.domain);
+
+    // https://www.reddit.com/r/uBlockOrigin/comments/d6vxzj/
+    //   Add support for `specifichide`.
+    if ( noCosmeticFiltering === false ) {
+        const specificHide =
+            µb.staticNetFilteringEngine.matchStringElementHide(
+                'specific',
+                request.url
+            );
+        response.noSpecificCosmeticFiltering = specificHide === 2;
+        if ( specificHide !== 0 && µb.logger.enabled ) {
+            µBlock.filteringContext
+                .duplicate()
+                .fromTabId(tabId)
+                .setURL(request.url)
+                .setRealm('network')
+                .setType('specifichide')
+                .setFilter(µb.staticNetFilteringEngine.toLogData())
+                .toLogger();
+        }
+    }
+
+    // Cosmetic filtering can be effectively disabled when both specific and
+    // generic cosmetic filtering are disabled.
+    if (
+        noCosmeticFiltering === false &&
+        response.noGenericCosmeticFiltering &&
+        response.noSpecificCosmeticFiltering
+    ) {
+        response.noCosmeticFiltering = true;
+    }
+
+    response.specificCosmeticFilters =
+        µb.cosmeticFilteringEngine.retrieveSpecificSelectors(request, response);
+
+    if ( µb.canInjectScriptletsNow === false ) {
+        response.scriptlets = µb.scriptletFilteringEngine.retrieve(request);
+    }
+
+    if ( µb.logger.enabled && response.noCosmeticFiltering !== true ) {
+        µb.logCosmeticFilters(tabId, frameId);
+    }
+
+    return response;
+};
+
 const onMessage = function(request, sender, callback) {
    // Async
    switch ( request.what ) {
@ -507,16 +599,11 @@ const onMessage = function(request, sender, callback) {
        break;
    }

-    // Sync
-    let response,
-        tabId, frameId,
-        pageStore = null;
+    const senderDetails = µb.getMessageSenderDetails(sender);
+    const pageStore = µb.pageStoreFromTabId(senderDetails.tabId);

-    if ( sender && sender.tab ) {
-        tabId = sender.tab.id;
-        frameId = sender.frameId;
-        pageStore = µb.pageStoreFromTabId(tabId);
-    }
+    // Sync
+    let response;

    switch ( request.what ) {
    case 'cosmeticFiltersInjected':
@ -528,88 +615,42 @@ const onMessage = function(request, sender, callback) {
            id: request.id,
            hash: request.hash,
            netSelectorCacheCountMax:
-                µb.cosmeticFilteringEngine.netSelectorCacheCountMax
+                µb.cosmeticFilteringEngine.netSelectorCacheCountMax,
        };
        if (
            µb.userSettings.collapseBlocked &&
-            pageStore &&
-            pageStore.getNetFilteringSwitch()
+            pageStore && pageStore.getNetFilteringSwitch()
        ) {
            pageStore.getBlockedResources(request, response);
        }
        break;

    case 'maybeGoodPopup':
-        µb.maybeGoodPopup.tabId = tabId;
+        µb.maybeGoodPopup.tabId = senderDetails.tabId;
        µb.maybeGoodPopup.url = request.url;
        break;

    case 'shouldRenderNoscriptTags':
        if ( pageStore === null ) { break; }
-        const fctxt = µb.filteringContext.fromTabId(tabId);
+        const fctxt = µb.filteringContext.fromTabId(senderDetails.tabId);
        if ( pageStore.filterScripting(fctxt, undefined) ) {
-            vAPI.tabs.executeScript(tabId, {
+            vAPI.tabs.executeScript(senderDetails.tabId, {
                file: '/js/scriptlets/noscript-spoof.js',
-                frameId: frameId,
-                runAt: 'document_end'
+                frameId: senderDetails.frameId,
+                runAt: 'document_end',
            });
        }
        break;

    case 'retrieveContentScriptParameters':
-        if (
-            pageStore === null ||
-            pageStore.getNetFilteringSwitch() === false ||
-            !request.url
-        ) {
-            break;
-        }
-        const noCosmeticFiltering = pageStore.noCosmeticFiltering === true;
-        response = {
-            collapseBlocked: µb.userSettings.collapseBlocked,
-            noCosmeticFiltering,
-            noGenericCosmeticFiltering: noCosmeticFiltering,
-        };
-        // https://github.com/uBlockOrigin/uAssets/issues/5704
-        //   `generichide` must be evaluated in the frame context.
-        if ( noCosmeticFiltering === false ) {
-            const genericHide =
-                µb.staticNetFilteringEngine.matchStringGenericHide(request.url);
-            response.noGenericCosmeticFiltering = genericHide === 2;
-            if ( genericHide !== 0 && µb.logger.enabled ) {
-                µBlock.filteringContext
-                    .duplicate()
-                    .fromTabId(tabId)
-                    .setURL(request.url)
-                    .setRealm('network')
-                    .setType('generichide')
-                    .setFilter(µb.staticNetFilteringEngine.toLogData())
-                    .toLogger();
-            }
-        }
-        request.tabId = tabId;
-        request.frameId = frameId;
-        request.hostname = µb.URI.hostnameFromURI(request.url);
-        request.domain = µb.URI.domainFromHostname(request.hostname);
-        request.entity = µb.URI.entityFromDomain(request.domain);
-        response.specificCosmeticFilters =
-            µb.cosmeticFilteringEngine.retrieveSpecificSelectors(
-                request,
-                response
-            );
-        if ( µb.canInjectScriptletsNow === false ) {
-            response.scriptlets = µb.scriptletFilteringEngine.retrieve(request);
-        }
-        if ( µb.logger.enabled && response.noCosmeticFiltering !== true ) {
-            µb.logCosmeticFilters(tabId, frameId);
-        }
+        response = retrieveContentScriptParameters(senderDetails, request);
        break;

    case 'retrieveGenericCosmeticSelectors':
-        request.tabId = tabId;
-        request.frameId = frameId;
+        request.tabId = senderDetails.tabId;
+        request.frameId = senderDetails.frameId;
        response = {
-            result: µb.cosmeticFilteringEngine.retrieveGenericSelectors(request)
+            result: µb.cosmeticFilteringEngine.retrieveGenericSelectors(request),
        };
        break;

--- a/src/js/reverselookup-worker.js
+++ b/src/js/reverselookup-worker.js
@ -176,17 +176,18 @@ const fromCosmeticFilter = function(details) {
            let end = content.indexOf('\n', pos);
            if ( end === -1 ) { end = content.length; }
            pos = end;
-            let fargs = JSON.parse(content.slice(beg, end));
+            const fargs = JSON.parse(content.slice(beg, end));
+            const filterType = fargs[0];

            // https://github.com/gorhill/uBlock/issues/2763
-            if ( fargs[0] >= 0 && fargs[0] <= 5 && details.ignoreGeneric ) {
+            if ( filterType >= 0 && filterType <= 5 && details.ignoreGeneric ) {
                continue;
            }

            // Do not confuse cosmetic filters with HTML ones.
-            if ( (fargs[0] === 64) !== isHtmlFilter ) { continue; }
+            if ( (filterType === 64) !== isHtmlFilter ) { continue; }

-            switch ( fargs[0] ) {
+            switch ( filterType ) {
            // Lowly generic cosmetic filters
            case 0: // simple id-based
                if (
@ -232,9 +233,17 @@ const fromCosmeticFilter = function(details) {
                ) {
                    break;
                }
-                if ( hostnameMatches(fargs[1]) ) {
-                    found = fargs[1] + prefix + selector;
+                if ( hostnameMatches(fargs[1]) === false ) { break; }
+                // https://www.reddit.com/r/uBlockOrigin/comments/d6vxzj/
+                //   Ignore match if specific cosmetic filters are disabled
+                if (
+                    filterType === 8 &&
+                    exception === false &&
+                    details.ignoreSpecific
+                ) {
+                    break;
                }
+                found = fargs[1] + prefix + selector;
                break;
            // Scriptlet injection
            case 32:
--- a/src/js/reverselookup.js
+++ b/src/js/reverselookup.js
@ -170,8 +170,16 @@ const fromCosmeticFilter = async function(details, callback) {
        id: id,
        domain: µBlock.URI.domainFromHostname(hostname),
        hostname: hostname,
-        ignoreGeneric: µBlock.staticNetFilteringEngine
-                             .matchStringGenericHide(details.url) === 2,
+        ignoreGeneric:
+            µBlock.staticNetFilteringEngine.matchStringElementHide(
+                'generic',
+                details.url
+            ) === 2,
+        ignoreSpecific:
+            µBlock.staticNetFilteringEngine.matchStringElementHide(
+                'specific',
+                details.url
+            ) === 2,
        rawFilter: details.rawFilter
    });
 };
--- a/src/js/static-ext-filtering.js
+++ b/src/js/static-ext-filtering.js
@ -44,7 +44,7 @@
  optional.

  The static extended filtering engine also offers parsing capabilities which
-  are available to all other specialized fitlering engines. For example,
+  are available to all other specialized filtering engines. For example,
  cosmetic and html filtering can ask the extended filtering engine to
  compile/validate selectors.

@ -303,7 +303,7 @@
            [ ':nth-ancestor', compileNthAncestorSelector ],
            [ ':spath', compileSpathExpression ],
            [ ':watch-attr', compileAttrList ],
-            [ ':xpath', compileXpathExpression ]
+            [ ':xpath', compileXpathExpression ],
        ]);

        // https://github.com/gorhill/uBlock/issues/2793#issuecomment-333269387
@ -517,7 +517,11 @@
            this.timer = undefined;
            this.strToIdMap = new Map();
            this.hostnameToSlotIdMap = new Map();
-            this.hostnameSlots = [];
+            // Avoid heterogeneous arrays. Thus:
+            this.hostnameSlots = [];        // array of integers
+            // IMPORTANT: initialize with an empty array because -0 is NOT < 0.
+            this.hostnameSlotsEx = [ [] ];  // Array of arrays of integers
+            // Array of strings (selectors and pseudo-selectors)
            this.strSlots = [];
            this.size = 0;
            if ( selfie !== undefined ) {
@ -543,24 +547,27 @@
                this.hostnameSlots.push(strId);
                return;
            }
-            const bucket = this.hostnameSlots[iHn];
-            if ( Array.isArray(bucket) ) {
-                bucket.push(strId);
-            } else {
-                this.hostnameSlots[iHn] = [ bucket, strId ];
+            if ( iHn < 0 ) {
+                this.hostnameSlotsEx[-iHn].push(strId);
+                return;
            }
+            const strIdEx = -this.hostnameSlotsEx.length;
+            this.hostnameToSlotIdMap.set(hn, strIdEx);
+            this.hostnameSlotsEx.push([ this.hostnameSlots[iHn], strId ]);
+            this.hostnameSlots[iHn] = strIdEx;
        }

        clear() {
            this.hostnameToSlotIdMap.clear();
            this.hostnameSlots.length = 0;
+            this.hostnameSlotsEx.length = 1;    // IMPORTANT: 1, not 0
            this.strSlots.length = 0;
            this.strToIdMap.clear();
            this.size = 0;
        }

-        collectGarbage(async = false) {
-            if ( async === false ) {
+        collectGarbage(later = false) {
+            if ( later === false ) {
                if ( this.timer !== undefined ) {
                    self.cancelIdleCallback(this.timer);
                    this.timer = undefined;
@ -578,23 +585,39 @@
            );
        }

-        retrieve(hostname, out) {
+        // modifiers = 1: return only specific items
+        // modifiers = 2: return only generic items
+        //
+        retrieve(hostname, out, modifiers = 0) {
+            if ( modifiers === 2 ) {
+                hostname = '';
+            }
            const mask = out.length - 1; // out.length must be power of two
            for (;;) {
                const filterId = this.hostnameToSlotIdMap.get(hostname);
                if ( filterId !== undefined ) {
-                    const bucket = this.hostnameSlots[filterId];
-                    if ( Array.isArray(bucket) ) {
-                        for ( const id of bucket ) {
-                            out[id & mask].add(this.strSlots[id >>> this.nBits]);
+                    if ( filterId < 0 ) {
+                        const bucket = this.hostnameSlotsEx[-filterId];
+                        for ( const strId of bucket ) {
+                            out[strId & mask].add(
+                                this.strSlots[strId >>> this.nBits]
+                            );
                        }
                    } else {
-                        out[bucket & mask].add(this.strSlots[bucket >>> this.nBits]);
+                        const strId = this.hostnameSlots[filterId];
+                        out[strId & mask].add(
+                            this.strSlots[strId >>> this.nBits]
+                        );
                    }
                }
                if ( hostname === '' ) { break; }
                const pos = hostname.indexOf('.');
-                hostname = pos !== -1 ? hostname.slice(pos + 1) : '';
+                if ( pos === -1 ) {
+                    if ( modifiers === 1 ) { break; }
+                    hostname = '';
+                } else {
+                    hostname = hostname.slice(pos + 1);
+                }
            }
        }

@ -602,6 +625,7 @@
            return {
                hostnameToSlotIdMap: Array.from(this.hostnameToSlotIdMap),
                hostnameSlots: this.hostnameSlots,
+                hostnameSlotsEx: this.hostnameSlotsEx,
                strSlots: this.strSlots,
                size: this.size
            };
@ -610,6 +634,7 @@
        fromSelfie(selfie) {
            this.hostnameToSlotIdMap = new Map(selfie.hostnameToSlotIdMap);
            this.hostnameSlots = selfie.hostnameSlots;
+            this.hostnameSlotsEx = selfie.hostnameSlotsEx;
            this.strSlots = selfie.strSlots;
            this.size = selfie.size;
        }
--- a/src/js/static-net-filtering.js
+++ b/src/js/static-net-filtering.js
@ -68,12 +68,13 @@ const typeNameToTypeValue = {
          'popunder': 12 << 4,
        'main_frame': 13 << 4,  // start of 1st-party-only behavorial filtering
       'generichide': 14 << 4,
-       'inline-font': 15 << 4,
-     'inline-script': 16 << 4,
-              'data': 17 << 4,  // special: a generic data holder
-          'redirect': 18 << 4,
-            'webrtc': 19 << 4,
-       'unsupported': 20 << 4
+      'specifichide': 15 << 4,
+       'inline-font': 16 << 4,
+     'inline-script': 17 << 4,
+              'data': 18 << 4,  // special: a generic data holder
+          'redirect': 19 << 4,
+            'webrtc': 20 << 4,
+       'unsupported': 21 << 4,
 };

 const otherTypeBitValue = typeNameToTypeValue.other;
@ -110,12 +111,13 @@ const typeValueToTypeName = {
    12: 'popunder',
    13: 'document',
    14: 'generichide',
-    15: 'inline-font',
-    16: 'inline-script',
-    17: 'data',
-    18: 'redirect',
-    19: 'webrtc',
-    20: 'unsupported'
+    15: 'specifichide',
+    16: 'inline-font',
+    17: 'inline-script',
+    18: 'data',
+    19: 'redirect',
+    20: 'webrtc',
+    21: 'unsupported'
 };

 const BlockImportant = BlockAction | Important;
@ -1848,11 +1850,11 @@ FilterParser.prototype.toNormalizedType = {
              'data': 'data',
               'doc': 'main_frame',
          'document': 'main_frame',
-          'elemhide': 'generichide',
              'font': 'font',
             'frame': 'sub_frame',
      'genericblock': 'unsupported',
       'generichide': 'generichide',
+             'ghide': 'generichide',
             'image': 'image',
       'inline-font': 'inline-font',
     'inline-script': 'inline-script',
@ -1864,6 +1866,8 @@ FilterParser.prototype.toNormalizedType = {
          'popunder': 'popunder',
             'popup': 'popup',
            'script': 'script',
+      'specifichide': 'specifichide',
+             'shide': 'specifichide',
        'stylesheet': 'stylesheet',
       'subdocument': 'sub_frame',
               'xhr': 'xmlhttprequest',
@ -2017,7 +2021,8 @@ FilterParser.prototype.parseOptions = function(s) {
            this.dataStr = '';
            continue;
        }
-        // Used by Adguard, purpose is unclear -- just ignore for now.
+        // Used by Adguard:
+        // https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters?aid=16593#empty-modifier
        if ( opt === 'empty' || opt === 'mp4' ) {
            if ( this.redirect !== 0 ) {
                this.unsupported = true;
@ -2031,6 +2036,13 @@ FilterParser.prototype.parseOptions = function(s) {
            this.badFilter = true;
            continue;
        }
+        // https://www.reddit.com/r/uBlockOrigin/comments/d6vxzj/
+        //   Add support for `elemhide`. Rarely used but it happens.
+        if ( opt === 'elemhide' || opt === 'ehide' ) {
+            this.parseTypeOption('specifichide', not);
+            this.parseTypeOption('generichide', not);
+            continue;
+        }
        // Unrecognized filter option: ignore whole filter.
        this.unsupported = true;
        break;
@ -3055,17 +3067,19 @@ FilterContainer.prototype.realmMatchString = function(
 //   filter if and only if there was a hit on an exception filter.
 // https://github.com/gorhill/uBlock/issues/2103
 //   User may want to override `generichide` exception filters.
+// https://www.reddit.com/r/uBlockOrigin/comments/d6vxzj/
+//   Add support for `specifichide`.

-FilterContainer.prototype.matchStringGenericHide = function(requestURL) {
-    const typeBits = typeNameToTypeValue['generichide'] | 0x80000000;
+FilterContainer.prototype.matchStringElementHide = function(type, url) {
+    const typeBits = typeNameToTypeValue[`${type}hide`] | 0x80000000;

    // Prime tokenizer: we get a normalized URL in return.
-    urlRegister = this.urlTokenizer.setURL(requestURL);
+    urlRegister = this.urlTokenizer.setURL(url);
    this.filterRegister = null;

    // These registers will be used by various filters
    pageHostnameRegister = requestHostnameRegister =
-        µb.URI.hostnameFromURI(requestURL);
+        µb.URI.hostnameFromURI(url);

    // Exception filters
    if ( this.realmMatchString(AllowAction, typeBits, FirstParty) ) {
--- a/src/js/utils.js
+++ b/src/js/utils.js
@ -707,3 +707,18 @@
        window.dispatchEvent(new CustomEvent(name));
    }
 };
+
+/******************************************************************************/
+
+µBlock.getMessageSenderDetails = function(sender) {
+    const r = {};
+    if ( sender instanceof Object ) {
+        r.url = sender.url;
+        r.frameId = sender.frameId;
+        const tab = sender.tab;
+        if ( tab instanceof Object ) {
+            r.tabId = tab.id;
+        }
+    }
+    return r;
+};
--- a/src/logger-ui.html
+++ b/src/logger-ui.html
@ -61,7 +61,7 @@
                            <div><span data-filtex="!" data-i18n="loggerRowFiltererBuiltinNot"></span>
                                <span style="flex-direction: column;">
                                    <div style="margin-bottom: 1px;"><span data-filtex="\t(?:css|(?:inline-)?font)\t">css/font</span><span data-filtex="\timage\t">image</span><span data-filtex="\tmedia\t">media</span><span data-filtex="\t(?:inline-)?script(?:ing)?\t">script</span></div>
-                                    <div><span data-filtex="\t(?:websocket|xhr)\t">xhr</span><span data-filtex="\tframe\t">frame</span><span data-filtex="\t(?:beacon|csp_report|ping|other)\t">other</span><span data-filtex="\t(?:dom|generichide)\t">dom</span></div>
+                                    <div><span data-filtex="\t(?:websocket|xhr)\t">xhr</span><span data-filtex="\tframe\t">frame</span><span data-filtex="\t(?:beacon|csp_report|ping|other)\t">other</span><span data-filtex="\t(?:dom|g(?:eneric)?hide|s(?:pecific)?hide)\t">dom</span></div>
                                </span>
                            </div>
                            <div><span data-filtex="!" data-i18n="loggerRowFiltererBuiltinNot"></span><span data-filtex="\t(?:0,)?1\t" data-i18n="loggerRowFiltererBuiltin1p"></span><span data-filtex="\t(?:3(?:,\d)?|0,3)\t" data-i18n="loggerRowFiltererBuiltin3p"></span></div>