Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1067 insertions, 0 deletions

diff --git a/gfx/thebes/gfxPlatformFontList.h b/gfx/thebes/gfxPlatformFontList.h
new file mode 100644
index 0000000000..930026d8cc
--- /dev/null
+++ b/gfx/thebes/gfxPlatformFontList.h
@@ -0,0 +1,1067 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * 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/. */
+
+#ifndef GFXPLATFORMFONTLIST_H_
+#define GFXPLATFORMFONTLIST_H_
+
+#include "nsClassHashtable.h"
+#include "nsTHashMap.h"
+#include "nsTHashSet.h"
+#include "nsRefPtrHashtable.h"
+#include "nsTHashtable.h"
+
+#include "gfxFontUtils.h"
+#include "gfxFontInfoLoader.h"
+#include "gfxFont.h"
+#include "gfxFontConstants.h"
+#include "gfxPlatform.h"
+#include "SharedFontList.h"
+
+#include "nsIMemoryReporter.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/EnumeratedArray.h"
+#include "mozilla/FontPropertyTypes.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/RangedArray.h"
+#include "mozilla/RecursiveMutex.h"
+#include "nsLanguageAtomService.h"
+
+#include "base/shared_memory.h"
+
+namespace mozilla {
+namespace fontlist {
+struct AliasData;
+}
+}  // namespace mozilla
+
+class CharMapHashKey : public PLDHashEntryHdr {
+ public:
+  typedef gfxCharacterMap* KeyType;
+  typedef const gfxCharacterMap* KeyTypePointer;
+
+  explicit CharMapHashKey(const gfxCharacterMap* aCharMap)
+      : mCharMap(const_cast<gfxCharacterMap*>(aCharMap)) {
+    MOZ_COUNT_CTOR(CharMapHashKey);
+  }
+  CharMapHashKey(const CharMapHashKey& toCopy) : mCharMap(toCopy.mCharMap) {
+    MOZ_COUNT_CTOR(CharMapHashKey);
+  }
+  MOZ_COUNTED_DTOR(CharMapHashKey)
+
+  gfxCharacterMap* GetKey() const { return mCharMap.get(); }
+
+  bool KeyEquals(const gfxCharacterMap* aCharMap) const {
+    MOZ_ASSERT(!aCharMap->mBuildOnTheFly && !mCharMap->mBuildOnTheFly,
+               "custom cmap used in shared cmap hashtable");
+    // cmaps built on the fly never match
+    if (aCharMap->mHash != mCharMap->mHash) {
+      return false;
+    }
+    return mCharMap->Equals(aCharMap);
+  }
+
+  static const gfxCharacterMap* KeyToPointer(gfxCharacterMap* aCharMap) {
+    return aCharMap;
+  }
+  static PLDHashNumber HashKey(const gfxCharacterMap* aCharMap) {
+    return aCharMap->mHash;
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+ protected:
+  friend class gfxPlatformFontList;
+
+  // gfxCharacterMap::Release() will notify us when the refcount of a
+  // charmap drops to 1; at that point, we'll lock the cache, check if
+  // the charmap is owned by the cache and this is still the only ref,
+  // and if so, delete it.
+  RefPtr<gfxCharacterMap> mCharMap;
+};
+
+/**
+ * A helper class used to create a SharedBitSet instance in a FontList's shared
+ * memory, while ensuring that we avoid bloating memory by avoiding creating
+ * duplicate instances.
+ */
+class ShmemCharMapHashEntry final : public PLDHashEntryHdr {
+ public:
+  typedef const gfxSparseBitSet* KeyType;
+  typedef const gfxSparseBitSet* KeyTypePointer;
+
+  /**
+   * Creation from a gfxSparseBitSet creates not only the ShmemCharMapHashEntry
+   * itself, but also a SharedBitSet in shared memory.
+   * Only the parent process creates and manages these entries.
+   */
+  explicit ShmemCharMapHashEntry(const gfxSparseBitSet* aCharMap);
+
+  ShmemCharMapHashEntry(ShmemCharMapHashEntry&&) = default;
+  ShmemCharMapHashEntry& operator=(ShmemCharMapHashEntry&&) = default;
+
+  /**
+   * Return a shared-memory Pointer that refers to the wrapped SharedBitSet.
+   * This can be passed to content processes to give them access to the same
+   * SharedBitSet as the parent stored.
+   */
+  mozilla::fontlist::Pointer GetCharMap() const { return mCharMap; }
+
+  bool KeyEquals(KeyType aCharMap) const {
+    // mHash is a 32-bit Adler checksum of the bitset; if it doesn't match we
+    // can immediately reject it as non-matching, but if it is equal we still
+    // need to do a full equality check below.
+    if (mHash != aCharMap->GetChecksum()) {
+      return false;
+    }
+
+    return mCharMap.ToPtr<const SharedBitSet>(mList)->Equals(aCharMap);
+  }
+
+  static KeyTypePointer KeyToPointer(KeyType aCharMap) { return aCharMap; }
+  static PLDHashNumber HashKey(KeyType aCharMap) {
+    return aCharMap->GetChecksum();
+  }
+
+  enum { ALLOW_MEMMOVE = true };
+
+ private:
+  // charMaps are stored in the shared memory that FontList objects point to,
+  // and are never deleted until the FontList (all referencing font lists,
+  // actually) have gone away.
+  mozilla::fontlist::FontList* mList;
+  mozilla::fontlist::Pointer mCharMap;
+  uint32_t mHash;
+};
+
+// gfxPlatformFontList is an abstract class for the global font list on the
+// system; concrete subclasses for each platform implement the actual interface
+// to the system fonts. This class exists because we cannot rely on the platform
+// font-finding APIs to behave in sensible/similar ways, particularly with rich,
+// complex OpenType families, so we do our own font family/style management here
+// instead.
+
+// Much of this is based on the old gfxQuartzFontCache, but adapted for use on
+// all platforms.
+
+struct FontListSizes {
+  uint32_t mFontListSize;  // size of the font list and dependent objects
+                           // (font family and face names, etc), but NOT
+                           // including the font table cache and the cmaps
+  uint32_t
+      mFontTableCacheSize;  // memory used for the gfxFontEntry table caches
+  uint32_t mCharMapsSize;   // memory used for cmap coverage info
+  uint32_t mLoaderSize;     // memory used for (platform-specific) loader
+  uint32_t mSharedSize;     // shared-memory use (reported by parent only)
+};
+
+class gfxUserFontSet;
+
+class gfxPlatformFontList : public gfxFontInfoLoader {
+  friend class InitOtherFamilyNamesRunnable;
+
+ public:
+  typedef mozilla::StretchRange StretchRange;
+  typedef mozilla::SlantStyleRange SlantStyleRange;
+  typedef mozilla::WeightRange WeightRange;
+  typedef mozilla::intl::Script Script;
+
+  using AutoLock = mozilla::RecursiveMutexAutoLock;
+  using AutoUnlock = mozilla::RecursiveMutexAutoUnlock;
+
+  // Class used to hold cached copies of the font-name prefs, so that they can
+  // be accessed from non-main-thread callers who are not allowed to touch the
+  // Preferences service.
+  class FontPrefs final {
+   public:
+    using HashMap = nsTHashMap<nsCStringHashKey, nsCString>;
+
+    FontPrefs();
+    ~FontPrefs() = default;
+
+    FontPrefs(const FontPrefs& aOther) = delete;
+    FontPrefs& operator=(const FontPrefs& aOther) = delete;
+
+    // Lookup the font.name.<foo> or font.name-list.<foo> pref for a given
+    // generic+langgroup pair.
+    bool LookupName(const nsACString& aPref, nsACString& aValue) const;
+    bool LookupNameList(const nsACString& aPref, nsACString& aValue) const;
+
+    // Does the font.name-list.emoji pref have a user-set value?
+    bool EmojiHasUserValue() const { return mEmojiHasUserValue; }
+
+    // Expose iterators over all the defined prefs of each type.
+    HashMap::ConstIterator NameIter() const { return mFontName.ConstIter(); }
+    HashMap::ConstIterator NameListIter() const {
+      return mFontNameList.ConstIter();
+    }
+
+   private:
+    static constexpr char kNamePrefix[] = "font.name.";
+    static constexpr char kNameListPrefix[] = "font.name-list.";
+
+    void Init();
+
+    HashMap mFontName;
+    HashMap mFontNameList;
+    bool mEmojiHasUserValue = false;
+  };
+
+  // For font family lists loaded from user preferences (prefs such as
+  // font.name-list.<generic>.<langGroup>) that map CSS generics to
+  // platform-specific font families.
+  typedef nsTArray<FontFamily> PrefFontList;
+
+  static gfxPlatformFontList* PlatformFontList() {
+    // If there is a font-list initialization thread, we need to let it run
+    // to completion before the font list can be used for anything else.
+    if (sInitFontListThread) {
+      // If we're currently on the initialization thread, just continue;
+      // otherwise wait for it to finish.
+      if (IsInitFontListThread()) {
+        return sPlatformFontList;
+      }
+      PR_JoinThread(sInitFontListThread);
+      sInitFontListThread = nullptr;
+      // If font-list initialization failed, the thread will have cleared
+      // the static sPlatformFontList pointer; we cannot proceed without any
+      // usable fonts.
+      if (!sPlatformFontList) {
+        MOZ_CRASH("Could not initialize gfxPlatformFontList");
+      }
+    }
+    if (!sPlatformFontList->IsInitialized()) {
+      if (!sPlatformFontList->InitFontList()) {
+        MOZ_CRASH("Could not initialize gfxPlatformFontList");
+      }
+    }
+    return sPlatformFontList;
+  }
+
+  static bool Initialize(gfxPlatformFontList* aList);
+
+  static void Shutdown() {
+    delete sPlatformFontList;
+    sPlatformFontList = nullptr;
+  }
+
+  bool IsInitialized() const { return mFontlistInitCount; }
+
+  virtual ~gfxPlatformFontList();
+
+  // Initialize font lists; return true on success, false if something fails.
+  bool InitFontList();
+
+  void FontListChanged();
+
+  /**
+   * Gathers (from a platform's underlying font system) the information needed
+   * to initialize a fontlist::Family with its Face members.
+   */
+  virtual void GetFacesInitDataForFamily(
+      const mozilla::fontlist::Family* aFamily,
+      nsTArray<mozilla::fontlist::Face::InitData>& aFaces,
+      bool aLoadCmaps) const {}
+
+  virtual void GetFontList(nsAtom* aLangGroup, const nsACString& aGenericFamily,
+                           nsTArray<nsString>& aListOfFonts);
+
+  // Pass false to notify content that the shared font list has been modified
+  // but not completely invalidated.
+  void UpdateFontList(bool aFullRebuild = true);
+
+  void ClearLangGroupPrefFonts() {
+    AutoLock lock(mLock);
+    ClearLangGroupPrefFontsLocked();
+  }
+  virtual void ClearLangGroupPrefFontsLocked() MOZ_REQUIRES(mLock);
+
+  void GetFontFamilyList(nsTArray<RefPtr<gfxFontFamily>>& aFamilyArray);
+
+  already_AddRefed<gfxFont> SystemFindFontForChar(
+      nsPresContext* aPresContext, uint32_t aCh, uint32_t aNextCh,
+      Script aRunScript, eFontPresentation aPresentation,
+      const gfxFontStyle* aStyle, FontVisibility* aVisibility);
+
+  // Flags to control optional behaviors in FindAndAddFamilies. The sense
+  // of the bit flags have been chosen such that the default parameter of
+  // FindFamiliesFlags(0) in FindFamily will give the most commonly-desired
+  // behavior, and only a few callsites need to explicitly pass other values.
+  enum class FindFamiliesFlags {
+    // If set, "other" (e.g. localized) family names should be loaded
+    // immediately; if clear, InitOtherFamilyNames is allowed to defer
+    // loading to avoid blocking.
+    eForceOtherFamilyNamesLoading = 1 << 0,
+
+    // If set, FindAndAddFamilies should not check for legacy "styled
+    // family" names to add to the font list. This is used to avoid
+    // a recursive search when using FindFamily to find a potential base
+    // family name for a styled variant.
+    eNoSearchForLegacyFamilyNames = 1 << 1,
+
+    // If set, FindAndAddFamilies will not add a missing entry to
+    // mOtherNamesMissed
+    eNoAddToNamesMissedWhenSearching = 1 << 2,
+
+    // If set, the family name was quoted and so must not be treated as a CSS
+    // generic.
+    eQuotedFamilyName = 1 << 3,
+
+    // If set, "hidden" font families (like ".SF NS Text" on macOS) are
+    // searched in addition to standard user-visible families.
+    eSearchHiddenFamilies = 1 << 4,
+  };
+
+  // Find family(ies) matching aFamily and append to the aOutput array
+  // (there may be multiple results in the case of fontconfig aliases, etc).
+  // Return true if any match was found and appended, false if none.
+  bool FindAndAddFamilies(
+      nsPresContext* aPresContext, mozilla::StyleGenericFontFamily aGeneric,
+      const nsACString& aFamily, nsTArray<FamilyAndGeneric>* aOutput,
+      FindFamiliesFlags aFlags, gfxFontStyle* aStyle = nullptr,
+      nsAtom* aLanguage = nullptr, gfxFloat aDevToCssSize = 1.0) {
+    AutoLock lock(mLock);
+    return FindAndAddFamiliesLocked(aPresContext, aGeneric, aFamily, aOutput,
+                                    aFlags, aStyle, aLanguage, aDevToCssSize);
+  }
+  virtual bool FindAndAddFamiliesLocked(
+      nsPresContext* aPresContext, mozilla::StyleGenericFontFamily aGeneric,
+      const nsACString& aFamily, nsTArray<FamilyAndGeneric>* aOutput,
+      FindFamiliesFlags aFlags, gfxFontStyle* aStyle = nullptr,
+      nsAtom* aLanguage = nullptr, gfxFloat aDevToCssSize = 1.0)
+      MOZ_REQUIRES(mLock);
+
+  gfxFontEntry* FindFontForFamily(nsPresContext* aPresContext,
+                                  const nsACString& aFamily,
+                                  const gfxFontStyle* aStyle);
+
+  mozilla::fontlist::FontList* SharedFontList() const {
+    return mSharedFontList.get();
+  }
+
+  // Create a handle for a single shmem block (identified by index) ready to
+  // be shared to the given processId.
+  void ShareFontListShmBlockToProcess(uint32_t aGeneration, uint32_t aIndex,
+                                      base::ProcessId aPid,
+                                      base::SharedMemoryHandle* aOut);
+
+  // Populate the array aBlocks with the complete list of shmem handles ready
+  // to be shared to the given processId.
+  void ShareFontListToProcess(nsTArray<base::SharedMemoryHandle>* aBlocks,
+                              base::ProcessId aPid);
+
+  void ShmBlockAdded(uint32_t aGeneration, uint32_t aIndex,
+                     base::SharedMemoryHandle aHandle);
+
+  base::SharedMemoryHandle ShareShmBlockToProcess(uint32_t aIndex,
+                                                  base::ProcessId aPid);
+
+  void SetCharacterMap(uint32_t aGeneration,
+                       const mozilla::fontlist::Pointer& aFacePtr,
+                       const gfxSparseBitSet& aMap);
+
+  void SetupFamilyCharMap(uint32_t aGeneration,
+                          const mozilla::fontlist::Pointer& aFamilyPtr);
+
+  // Start the async cmap loading process, if not already under way, from the
+  // given family index. (For use in any process that needs font lookups.)
+  void StartCmapLoadingFromFamily(uint32_t aStartIndex);
+
+  // [Parent] Handle request from content process to start cmap loading.
+  void StartCmapLoading(uint32_t aGeneration, uint32_t aStartIndex);
+
+  void CancelLoadCmapsTask() {
+    if (mLoadCmapsRunnable) {
+      mLoadCmapsRunnable->Cancel();
+      mLoadCmapsRunnable = nullptr;
+    }
+  }
+
+  // Populate aFamily with face records, and if aLoadCmaps is true, also load
+  // their character maps (rather than leaving this to be done lazily).
+  // Note that even when aFamily->IsInitialized() is true, it can make sense
+  // to call InitializeFamily again if passing aLoadCmaps=true, in order to
+  // ensure cmaps are loaded.
+  [[nodiscard]] bool InitializeFamily(mozilla::fontlist::Family* aFamily,
+                                      bool aLoadCmaps = false);
+  void InitializeFamily(uint32_t aGeneration, uint32_t aFamilyIndex,
+                        bool aLoadCmaps);
+
+  // name lookup table methods
+
+  void AddOtherFamilyNames(gfxFontFamily* aFamilyEntry,
+                           const nsTArray<nsCString>& aOtherFamilyNames);
+
+  void AddFullname(gfxFontEntry* aFontEntry, const nsCString& aFullname) {
+    AutoLock lock(mLock);
+    AddFullnameLocked(aFontEntry, aFullname);
+  }
+  void AddFullnameLocked(gfxFontEntry* aFontEntry, const nsCString& aFullname)
+      MOZ_REQUIRES(mLock);
+
+  void AddPostscriptName(gfxFontEntry* aFontEntry,
+                         const nsCString& aPostscriptName) {
+    AutoLock lock(mLock);
+    AddPostscriptNameLocked(aFontEntry, aPostscriptName);
+  }
+  void AddPostscriptNameLocked(gfxFontEntry* aFontEntry,
+                               const nsCString& aPostscriptName)
+      MOZ_REQUIRES(mLock);
+
+  bool NeedFullnamePostscriptNames() { return mExtraNames != nullptr; }
+
+  /**
+   * Read PSName and FullName of the given face, for src:local lookup,
+   * returning true if actually implemented and succeeded.
+   */
+  virtual bool ReadFaceNames(const mozilla::fontlist::Family* aFamily,
+                             const mozilla::fontlist::Face* aFace,
+                             nsCString& aPSName, nsCString& aFullName) {
+    return false;
+  }
+
+  // initialize localized family names
+  bool InitOtherFamilyNames(bool aDeferOtherFamilyNamesLoading);
+  bool InitOtherFamilyNames(uint32_t aGeneration, bool aDefer);
+
+  // pure virtual functions, to be provided by concrete subclasses
+
+  // get the system default font family
+  FontFamily GetDefaultFont(nsPresContext* aPresContext,
+                            const gfxFontStyle* aStyle);
+  FontFamily GetDefaultFontLocked(nsPresContext* aPresContext,
+                                  const gfxFontStyle* aStyle)
+      MOZ_REQUIRES(mLock);
+
+  // get the "ultimate" default font, for use if the font list is otherwise
+  // unusable (e.g. in the middle of being updated)
+  gfxFontEntry* GetDefaultFontEntry() {
+    AutoLock lock(mLock);
+    return mDefaultFontEntry.get();
+  }
+
+  /**
+   * Look up a font by name on the host platform.
+   *
+   * Note that the style attributes (weight, stretch, style) are NOT used in
+   * selecting the platform font, which is looked up by name only; these are
+   * values to be recorded in the new font entry.
+   */
+  virtual gfxFontEntry* LookupLocalFont(nsPresContext* aPresContext,
+                                        const nsACString& aFontName,
+                                        WeightRange aWeightForEntry,
+                                        StretchRange aStretchForEntry,
+                                        SlantStyleRange aStyleForEntry) = 0;
+
+  /**
+   * Create a new platform font from downloaded data (@font-face).
+   *
+   * Note that the style attributes (weight, stretch, style) are NOT related
+   * (necessarily) to any values within the font resource itself; these are
+   * values to be recorded in the new font entry and used for face selection,
+   * in place of whatever inherent style attributes the resource may have.
+   *
+   * This method takes ownership of the data block passed in as aFontData,
+   * and must ensure it is free()'d when no longer required.
+   */
+  virtual gfxFontEntry* MakePlatformFont(const nsACString& aFontName,
+                                         WeightRange aWeightForEntry,
+                                         StretchRange aStretchForEntry,
+                                         SlantStyleRange aStyleForEntry,
+                                         const uint8_t* aFontData,
+                                         uint32_t aLength) = 0;
+
+  // get the standard family name on the platform for a given font name
+  // (platforms may override, eg Mac)
+  virtual bool GetStandardFamilyName(const nsCString& aFontName,
+                                     nsACString& aFamilyName);
+
+  // Get the localized family name for a given font family.
+  bool GetLocalizedFamilyName(const FontFamily& aFamily,
+                              nsACString& aFamilyName);
+
+  // get the default font name which is available on the system from
+  // font.name-list.*.  if there are no available fonts in the pref,
+  // returns an empty FamilyAndGeneric record.
+  FamilyAndGeneric GetDefaultFontFamily(const nsACString& aLangGroup,
+                                        const nsACString& aGenericFamily);
+
+  virtual void AddSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf,
+                                      FontListSizes* aSizes) const;
+  virtual void AddSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf,
+                                      FontListSizes* aSizes) const;
+
+  mozilla::fontlist::Pointer GetShmemCharMap(const gfxSparseBitSet* aCmap) {
+    AutoLock lock(mLock);
+    return GetShmemCharMapLocked(aCmap);
+  }
+  mozilla::fontlist::Pointer GetShmemCharMapLocked(const gfxSparseBitSet* aCmap)
+      MOZ_REQUIRES(mLock);
+
+  // Search for existing cmap that matches the input; return the input if no
+  // match is found.
+  already_AddRefed<gfxCharacterMap> FindCharMap(gfxCharacterMap* aCmap);
+
+  // Remove the cmap from the shared cmap set if it holds the only remaining
+  // reference to the object.
+  void MaybeRemoveCmap(gfxCharacterMap* aCharMap);
+
+  // Keep track of userfont sets to notify when global fontlist changes occur.
+  void AddUserFontSet(gfxUserFontSet* aUserFontSet) {
+    AutoLock lock(mLock);
+    mUserFontSetList.Insert(aUserFontSet);
+  }
+
+  void RemoveUserFontSet(gfxUserFontSet* aUserFontSet) {
+    AutoLock lock(mLock);
+    mUserFontSetList.Remove(aUserFontSet);
+  }
+
+  static const gfxFontEntry::ScriptRange sComplexScriptRanges[];
+
+  void GetFontlistInitInfo(uint32_t& aNumInits, uint32_t& aLoaderState) {
+    aNumInits = mFontlistInitCount;
+    aLoaderState = (uint32_t)mState;
+  }
+
+  virtual void AddGenericFonts(nsPresContext* aPresContext,
+                               mozilla::StyleGenericFontFamily aGenericType,
+                               nsAtom* aLanguage,
+                               nsTArray<FamilyAndGeneric>& aFamilyList);
+
+  /**
+   * Given a Face from the shared font list, return a gfxFontEntry usable
+   * by the current process. This returns a cached entry if available,
+   * otherwise it calls the (platform-specific) CreateFontEntry method to
+   * make one, and adds it to the cache.
+   */
+  gfxFontEntry* GetOrCreateFontEntry(mozilla::fontlist::Face* aFace,
+                                     const mozilla::fontlist::Family* aFamily) {
+    AutoLock lock(mLock);
+    return GetOrCreateFontEntryLocked(aFace, aFamily);
+  }
+  gfxFontEntry* GetOrCreateFontEntryLocked(
+      mozilla::fontlist::Face* aFace, const mozilla::fontlist::Family* aFamily)
+      MOZ_REQUIRES(mLock);
+
+  const FontPrefs* GetFontPrefs() const MOZ_REQUIRES(mLock) {
+    return mFontPrefs.get();
+  }
+
+  bool EmojiPrefHasUserValue() const {
+    AutoLock lock(mLock);
+    return mFontPrefs->EmojiHasUserValue();
+  }
+
+  PrefFontList* GetPrefFontsLangGroup(
+      nsPresContext* aPresContext, mozilla::StyleGenericFontFamily aGenericType,
+      eFontPrefLang aPrefLang) {
+    AutoLock lock(mLock);
+    return GetPrefFontsLangGroupLocked(aPresContext, aGenericType, aPrefLang);
+  }
+  PrefFontList* GetPrefFontsLangGroupLocked(
+      nsPresContext* aPresContext, mozilla::StyleGenericFontFamily aGenericType,
+      eFontPrefLang aPrefLang) MOZ_REQUIRES(mLock);
+
+  // in some situations, need to make decisions about ambiguous characters, may
+  // need to look at multiple pref langs
+  void GetLangPrefs(eFontPrefLang aPrefLangs[], uint32_t& aLen,
+                    eFontPrefLang aCharLang, eFontPrefLang aPageLang);
+
+  // convert a lang group to enum constant (i.e. "zh-TW" ==>
+  // eFontPrefLang_ChineseTW)
+  static eFontPrefLang GetFontPrefLangFor(const char* aLang);
+
+  // convert a lang group atom to enum constant
+  static eFontPrefLang GetFontPrefLangFor(nsAtom* aLang);
+
+  // convert an enum constant to a lang group atom
+  static nsAtom* GetLangGroupForPrefLang(eFontPrefLang aLang);
+
+  // convert a enum constant to lang group string (i.e. eFontPrefLang_ChineseTW
+  // ==> "zh-TW")
+  static const char* GetPrefLangName(eFontPrefLang aLang);
+
+  // map a char code to a font language for Preferences
+  static eFontPrefLang GetFontPrefLangFor(uint32_t aCh);
+
+  // returns true if a pref lang is CJK
+  static bool IsLangCJK(eFontPrefLang aLang);
+
+  // helper method to add a pref lang to an array, if not already in array
+  static void AppendPrefLang(eFontPrefLang aPrefLangs[], uint32_t& aLen,
+                             eFontPrefLang aAddLang);
+
+  // default serif/sans-serif choice based on font.default.xxx prefs
+  mozilla::StyleGenericFontFamily GetDefaultGeneric(eFontPrefLang aLang);
+
+  // Returns true if the font family whitelist is not empty. In this case we
+  // ignore the "CSS visibility level"; only the given fonts are present in
+  // the browser's font list.
+  bool IsFontFamilyWhitelistActive() const {
+    return mFontFamilyWhitelistActive;
+  };
+
+  static void FontWhitelistPrefChanged(const char* aPref, void* aClosure);
+
+  bool AddWithLegacyFamilyName(const nsACString& aLegacyName,
+                               gfxFontEntry* aFontEntry,
+                               FontVisibility aVisibility);
+
+  static const char* GetGenericName(
+      mozilla::StyleGenericFontFamily aGenericType);
+
+  bool SkipFontFallbackForChar(FontVisibility aVisibility, uint32_t aCh) const {
+    AutoLock lock(mLock);
+    return mCodepointsWithNoFonts[aVisibility].test(aCh);
+  }
+
+  // Return whether the given font-family record should be visible to CSS,
+  // in a context with the given FontVisibility setting.
+  bool IsVisibleToCSS(const gfxFontFamily& aFamily,
+                      FontVisibility aVisibility) const;
+  bool IsVisibleToCSS(const mozilla::fontlist::Family& aFamily,
+                      FontVisibility aVisibility) const;
+
+  // (Re-)initialize the set of codepoints that we know cannot be rendered.
+  void InitializeCodepointsWithNoFonts() MOZ_REQUIRES(mLock);
+
+  // If using the shared font list, returns a generation count that is
+  // incremented if/when the platform list is reinitialized (e.g. because
+  // fonts are installed/removed while the browser is running), such that
+  // existing references to shared font family or face objects and character
+  // maps will no longer be valid.
+  // (The legacy (non-shared) list just returns 0 here.)
+  uint32_t GetGeneration() const;
+
+  // Sometimes we need to know if we're on the InitFontList startup thread.
+  static bool IsInitFontListThread() {
+    return PR_GetCurrentThread() == sInitFontListThread;
+  }
+
+  bool IsKnownIconFontFamily(const nsAtom* aFamilyName) const;
+  void LoadIconFontOverrideList();
+
+  void Lock() MOZ_CAPABILITY_ACQUIRE(mLock) { mLock.Lock(); }
+  void Unlock() MOZ_CAPABILITY_RELEASE(mLock) { mLock.Unlock(); }
+
+  // This is only public because some external callers want to be able to
+  // assert about the locked status.
+  mutable mozilla::RecursiveMutex mLock;
+
+ protected:
+  friend class mozilla::fontlist::FontList;
+  friend class InitOtherFamilyNamesForStylo;
+
+  template <size_t N>
+  static bool FamilyInList(const nsACString& aName, const char* (&aList)[N]) {
+    return FamilyInList(aName, aList, N);
+  }
+  static bool FamilyInList(const nsACString& aName, const char* aList[],
+                           size_t aCount);
+
+  // Check list is correctly sorted (in debug build only; no-op on release).
+  template <size_t N>
+  static void CheckFamilyList(const char* (&aList)[N]) {
+    CheckFamilyList(aList, N);
+  }
+  static void CheckFamilyList(const char* aList[], size_t aCount);
+
+  class InitOtherFamilyNamesRunnable : public mozilla::CancelableRunnable {
+   public:
+    InitOtherFamilyNamesRunnable()
+        : CancelableRunnable(
+              "gfxPlatformFontList::InitOtherFamilyNamesRunnable"),
+          mIsCanceled(false) {}
+
+    NS_IMETHOD Run() override {
+      if (mIsCanceled) {
+        return NS_OK;
+      }
+
+      gfxPlatformFontList* fontList = gfxPlatformFontList::PlatformFontList();
+      if (!fontList) {
+        return NS_OK;
+      }
+
+      fontList->InitOtherFamilyNamesInternal(true);
+
+      return NS_OK;
+    }
+
+    nsresult Cancel() override {
+      mIsCanceled = true;
+
+      return NS_OK;
+    }
+
+   private:
+    bool mIsCanceled;
+  };
+
+  class MemoryReporter final : public nsIMemoryReporter {
+    ~MemoryReporter() = default;
+
+   public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIMEMORYREPORTER
+  };
+
+  class PrefName final : public nsAutoCString {
+    void Init(const nsACString& aGeneric, const nsACString& aLangGroup) {
+      Assign(aGeneric);
+      if (!aLangGroup.IsEmpty()) {
+        Append('.');
+        Append(aLangGroup);
+      }
+    }
+
+   public:
+    PrefName(const nsACString& aGeneric, const nsACString& aLangGroup) {
+      Init(aGeneric, aLangGroup);
+    }
+
+    PrefName(const char* aGeneric, const char* aLangGroup) {
+      Init(nsDependentCString(aGeneric), nsDependentCString(aLangGroup));
+    }
+
+    PrefName(const char* aGeneric, nsAtom* aLangGroup) {
+      if (aLangGroup) {
+        Init(nsDependentCString(aGeneric), nsAtomCString(aLangGroup));
+      } else {
+        Init(nsDependentCString(aGeneric), nsAutoCString());
+      }
+    }
+  };
+
+  explicit gfxPlatformFontList(bool aNeedFullnamePostscriptNames = true);
+
+  static gfxPlatformFontList* sPlatformFontList;
+
+  /**
+   * Convenience method to return the first matching family (if any) as found
+   * by FindAndAddFamilies(). The family will be initialized (synchronously)
+   * if this has not already been done, so the returned pointer, if non-null,
+   * is ready for use.
+   */
+  mozilla::fontlist::Family* FindSharedFamily(
+      nsPresContext* aPresContext, const nsACString& aFamily,
+      FindFamiliesFlags aFlags = FindFamiliesFlags(0),
+      gfxFontStyle* aStyle = nullptr, nsAtom* aLanguage = nullptr,
+      gfxFloat aDevToCssSize = 1.0) MOZ_REQUIRES(mLock);
+
+  gfxFontFamily* FindUnsharedFamily(
+      nsPresContext* aPresContext, const nsACString& aFamily,
+      FindFamiliesFlags aFlags = FindFamiliesFlags(0),
+      gfxFontStyle* aStyle = nullptr, nsAtom* aLanguage = nullptr,
+      gfxFloat aDevToCssSize = 1.0) MOZ_REQUIRES(mLock) {
+    if (SharedFontList()) {
+      return nullptr;
+    }
+    AutoTArray<FamilyAndGeneric, 1> families;
+    if (FindAndAddFamiliesLocked(
+            aPresContext, mozilla::StyleGenericFontFamily::None, aFamily,
+            &families, aFlags, aStyle, aLanguage, aDevToCssSize)) {
+      return families[0].mFamily.mUnshared;
+    }
+    return nullptr;
+  }
+
+  FontFamily FindFamily(nsPresContext* aPresContext, const nsACString& aFamily,
+                        FindFamiliesFlags aFlags = FindFamiliesFlags(0),
+                        gfxFontStyle* aStyle = nullptr,
+                        nsAtom* aLanguage = nullptr,
+                        gfxFloat aDevToCssSize = 1.0) MOZ_REQUIRES(mLock) {
+    if (SharedFontList()) {
+      return FontFamily(FindSharedFamily(aPresContext, aFamily, aFlags, aStyle,
+                                         aLanguage, aDevToCssSize));
+    }
+    return FontFamily(FindUnsharedFamily(aPresContext, aFamily, aFlags, aStyle,
+                                         aLanguage, aDevToCssSize));
+  }
+
+  // Lookup family name in global family list without substitutions or
+  // localized family name lookup. Used for common font fallback families.
+  gfxFontFamily* FindFamilyByCanonicalName(const nsACString& aFamily)
+      MOZ_REQUIRES(mLock) {
+    nsAutoCString key;
+    gfxFontFamily* familyEntry;
+    GenerateFontListKey(aFamily, key);
+    if ((familyEntry = mFontFamilies.GetWeak(key))) {
+      return CheckFamily(familyEntry);
+    }
+    return nullptr;
+  }
+
+  // returns default font for a given character, null otherwise
+  already_AddRefed<gfxFont> CommonFontFallback(nsPresContext* aPresContext,
+                                               uint32_t aCh, uint32_t aNextCh,
+                                               Script aRunScript,
+                                               eFontPresentation aPresentation,
+                                               const gfxFontStyle* aMatchStyle,
+                                               FontFamily& aMatchedFamily)
+      MOZ_REQUIRES(mLock);
+
+  // Search fonts system-wide for a given character, null if not found.
+  already_AddRefed<gfxFont> GlobalFontFallback(
+      nsPresContext* aPresContext, uint32_t aCh, uint32_t aNextCh,
+      Script aRunScript, eFontPresentation aPresentation,
+      const gfxFontStyle* aMatchStyle, uint32_t& aCmapCount,
+      FontFamily& aMatchedFamily) MOZ_REQUIRES(mLock);
+
+  // Platform-specific implementation of global font fallback, if any;
+  // this may return nullptr in which case the default cmap-based fallback
+  // will be performed.
+  virtual gfxFontEntry* PlatformGlobalFontFallback(
+      nsPresContext* aPresContext, const uint32_t aCh, Script aRunScript,
+      const gfxFontStyle* aMatchStyle, FontFamily& aMatchedFamily) {
+    return nullptr;
+  }
+
+  // whether system-based font fallback is used or not
+  // if system fallback is used, no need to load all cmaps
+  virtual bool UsesSystemFallback() { return false; }
+
+  void AppendCJKPrefLangs(eFontPrefLang aPrefLangs[], uint32_t& aLen,
+                          eFontPrefLang aCharLang, eFontPrefLang aPageLang)
+      MOZ_REQUIRES(mLock);
+
+  // verifies that a family contains a non-zero font count
+  gfxFontFamily* CheckFamily(gfxFontFamily* aFamily) MOZ_REQUIRES(mLock);
+
+  // initialize localized family names
+  void InitOtherFamilyNamesInternal(bool aDeferOtherFamilyNamesLoading);
+  void CancelInitOtherFamilyNamesTask();
+
+  void AddToMissedNames(const nsCString& aKey) MOZ_REQUIRES(mLock);
+
+  // search through font families, looking for a given name, initializing
+  // facename lists along the way. first checks all families with names
+  // close to face name, then searchs all families if not found.
+  gfxFontEntry* SearchFamiliesForFaceName(const nsACString& aFaceName)
+      MOZ_REQUIRES(mLock);
+
+  // helper method for finding fullname/postscript names in facename lists
+  gfxFontEntry* FindFaceName(const nsACString& aFaceName) MOZ_REQUIRES(mLock);
+
+  // look up a font by name, for cases where platform font list
+  // maintains explicit mappings of fullname/psname ==> font
+  virtual gfxFontEntry* LookupInFaceNameLists(const nsACString& aFaceName)
+      MOZ_REQUIRES(mLock);
+
+  gfxFontEntry* LookupInSharedFaceNameList(nsPresContext* aPresContext,
+                                           const nsACString& aFaceName,
+                                           WeightRange aWeightForEntry,
+                                           StretchRange aStretchForEntry,
+                                           SlantStyleRange aStyleForEntry)
+      MOZ_REQUIRES(mLock);
+
+  // load the bad underline blocklist from pref.
+  void LoadBadUnderlineList();
+
+  void GenerateFontListKey(const nsACString& aKeyName, nsACString& aResult);
+
+  virtual void GetFontFamilyNames(nsTArray<nsCString>& aFontFamilyNames)
+      MOZ_REQUIRES(mLock);
+
+  // helper function to map lang to lang group
+  nsAtom* GetLangGroup(nsAtom* aLanguage);
+
+  // gfxFontInfoLoader overrides, used to load in font cmaps
+  void InitLoader() MOZ_REQUIRES(mLock) override;
+  bool LoadFontInfo() override;
+  void CleanupLoader() override;
+
+  void ForceGlobalReflowLocked(
+      gfxPlatform::NeedsReframe aNeedsReframe,
+      gfxPlatform::BroadcastToChildren aBroadcastToChildren =
+          gfxPlatform::BroadcastToChildren::Yes) MOZ_REQUIRES(mLock);
+
+  // read the loader initialization prefs, and start it
+  void GetPrefsAndStartLoader();
+
+  // If aForgetLocalFaces is true, all gfxFontEntries for src:local fonts must
+  // be discarded (not potentially reused to satisfy the rebuilt rules),
+  // because they may no longer be valid.
+  void RebuildLocalFonts(bool aForgetLocalFaces = false) MOZ_REQUIRES(mLock);
+
+  void ResolveGenericFontNames(nsPresContext* aPresContext,
+                               mozilla::StyleGenericFontFamily aGenericType,
+                               eFontPrefLang aPrefLang,
+                               PrefFontList* aGenericFamilies)
+      MOZ_REQUIRES(mLock);
+
+  void ResolveEmojiFontNames(nsPresContext* aPresContext,
+                             PrefFontList* aGenericFamilies)
+      MOZ_REQUIRES(mLock);
+
+  void GetFontFamiliesFromGenericFamilies(
+      nsPresContext* aPresContext, mozilla::StyleGenericFontFamily aGenericType,
+      nsTArray<nsCString>& aGenericNameFamilies, nsAtom* aLangGroup,
+      PrefFontList* aFontFamilies) MOZ_REQUIRES(mLock);
+
+  virtual nsresult InitFontListForPlatform() MOZ_REQUIRES(mLock) = 0;
+  virtual void InitSharedFontListForPlatform() MOZ_REQUIRES(mLock) {}
+
+  virtual gfxFontEntry* CreateFontEntry(
+      mozilla::fontlist::Face* aFace,
+      const mozilla::fontlist::Family* aFamily) {
+    return nullptr;
+  }
+
+  /**
+   * Methods to apply the font.system.whitelist anti-fingerprinting pref,
+   * by filtering the list of installed fonts so that only whitelisted families
+   * are exposed.
+   * There are separate implementations of this for the per-process font list
+   * and for the shared-memory font list.
+   */
+  void ApplyWhitelist() MOZ_REQUIRES(mLock);
+  void ApplyWhitelist(nsTArray<mozilla::fontlist::Family::InitData>& aFamilies);
+
+  // Create a new gfxFontFamily of the appropriate subclass for the platform,
+  // used when AddWithLegacyFamilyName needs to create a new family.
+  virtual gfxFontFamily* CreateFontFamily(const nsACString& aName,
+                                          FontVisibility aVisibility) const = 0;
+
+  /**
+   * For the post-startup font info loader task.
+   * Perform platform-specific work to read alternate names (if any) for a
+   * font family, recording them in mAliasTable. Once alternate names have been
+   * loaded for all families, the accumulated records are stored in the shared
+   * font list's mAliases list.
+   * Some platforms (currently Linux/fontconfig) may load alternate names as
+   * part of initially populating the font list with family records, in which
+   * case this method is unused.
+   */
+  virtual void ReadFaceNamesForFamily(mozilla::fontlist::Family* aFamily,
+                                      bool aNeedFullnamePostscriptNames)
+      MOZ_REQUIRES(mLock) {}
+
+  typedef nsRefPtrHashtable<nsCStringHashKey, gfxFontFamily> FontFamilyTable;
+  typedef nsRefPtrHashtable<nsCStringHashKey, gfxFontEntry> FontEntryTable;
+
+  // used by memory reporter to accumulate sizes of family names in the table
+  static size_t SizeOfFontFamilyTableExcludingThis(
+      const FontFamilyTable& aTable, mozilla::MallocSizeOf aMallocSizeOf);
+  static size_t SizeOfFontEntryTableExcludingThis(
+      const FontEntryTable& aTable, mozilla::MallocSizeOf aMallocSizeOf);
+
+  // Platform-specific helper for GetDefaultFont(...).
+  virtual FontFamily GetDefaultFontForPlatform(nsPresContext* aPresContext,
+                                               const gfxFontStyle* aStyle,
+                                               nsAtom* aLanguage = nullptr)
+      MOZ_REQUIRES(mLock) = 0;
+
+  // canonical family name ==> family entry (unique, one name per family entry)
+  FontFamilyTable mFontFamilies MOZ_GUARDED_BY(mLock);
+
+  // other family name ==> family entry (not unique, can have multiple names per
+  // family entry, only names *other* than the canonical names are stored here)
+  FontFamilyTable mOtherFamilyNames MOZ_GUARDED_BY(mLock);
+
+  // flag set after InitOtherFamilyNames is called upon first name lookup miss
+  mozilla::Atomic<bool> mOtherFamilyNamesInitialized;
+
+  // The pending InitOtherFamilyNames() task.
+  RefPtr<mozilla::CancelableRunnable> mPendingOtherFamilyNameTask;
+
+  // flag set after fullname and Postcript name lists are populated
+  mozilla::Atomic<bool> mFaceNameListsInitialized;
+
+  struct ExtraNames {
+    ExtraNames() = default;
+
+    // fullname ==> font entry (unique, one name per font entry)
+    FontEntryTable mFullnames{64};
+    // Postscript name ==> font entry (unique, one name per font entry)
+    FontEntryTable mPostscriptNames{64};
+  };
+  // The lock is needed to guard access to the actual name tables, but does not
+  // need to be held to just test whether mExtraNames is non-null as it is set
+  // during initialization before other threads have a chance to see it.
+  mozilla::UniquePtr<ExtraNames> mExtraNames MOZ_PT_GUARDED_BY(mLock);
+
+  // face names missed when face name loading takes a long time
+  mozilla::UniquePtr<nsTHashSet<nsCString>> mFaceNamesMissed
+      MOZ_GUARDED_BY(mLock);
+
+  // localized family names missed when face name loading takes a long time
+  mozilla::UniquePtr<nsTHashSet<nsCString>> mOtherNamesMissed
+      MOZ_GUARDED_BY(mLock);
+
+  typedef mozilla::RangedArray<mozilla::UniquePtr<PrefFontList>,
+                               size_t(mozilla::StyleGenericFontFamily::None),
+                               size_t(
+                                   mozilla::StyleGenericFontFamily::MozEmoji)>
+      PrefFontsForLangGroup;
+  mozilla::RangedArray<PrefFontsForLangGroup, eFontPrefLang_First,
+                       eFontPrefLang_Count>
+      mLangGroupPrefFonts MOZ_GUARDED_BY(mLock);
+  mozilla::UniquePtr<PrefFontList> mEmojiPrefFont MOZ_GUARDED_BY(mLock);
+
+  // When system-wide font lookup fails for a character, cache it to skip future
+  // searches. This is an array of bitsets, one for each FontVisibility level.
+  mozilla::EnumeratedArray<FontVisibility, FontVisibility::Count,
+                           gfxSparseBitSet>
+      mCodepointsWithNoFonts MOZ_GUARDED_BY(mLock);
+
+  // the family to use for U+FFFD fallback, to avoid expensive search every time
+  // on pages with lots of problems
+  mozilla::EnumeratedArray<FontVisibility, FontVisibility::Count, FontFamily>
+      mReplacementCharFallbackFamily MOZ_GUARDED_BY(mLock);
+
+  // Sorted array of lowercased family names; use ContainsSorted to test
+  nsTArray<nsCString> mBadUnderlineFamilyNames;
+
+  // character map data shared across families
+  // contains weak ptrs to cmaps shared by font entry objects
+  nsTHashtable<CharMapHashKey> mSharedCmaps MOZ_GUARDED_BY(mLock);
+
+  nsTHashtable<ShmemCharMapHashEntry> mShmemCharMaps MOZ_GUARDED_BY(mLock);
+
+  // data used as part of the font cmap loading process
+  nsTArray<RefPtr<gfxFontFamily>> mFontFamiliesToLoad MOZ_GUARDED_BY(mLock);
+  uint32_t mStartIndex MOZ_GUARDED_BY(mLock) = 0;
+  uint32_t mNumFamilies MOZ_GUARDED_BY(mLock) = 0;
+
+  // xxx - info for diagnosing no default font aborts
+  // see bugs 636957, 1070983, 1189129
+  uint32_t mFontlistInitCount = 0;  // num times InitFontList called
+
+  nsTHashSet<gfxUserFontSet*> mUserFontSetList MOZ_GUARDED_BY(mLock);
+
+  nsLanguageAtomService* mLangService = nullptr;
+
+  nsTArray<uint32_t> mCJKPrefLangs MOZ_GUARDED_BY(mLock);
+  nsTArray<mozilla::StyleGenericFontFamily> mDefaultGenericsLangGroup
+      MOZ_GUARDED_BY(mLock);
+
+  nsTArray<nsCString> mEnabledFontsList;
+  nsTHashSet<nsCString> mIconFontsSet;
+
+  mozilla::UniquePtr<mozilla::fontlist::FontList> mSharedFontList;
+
+  nsClassHashtable<nsCStringHashKey, mozilla::fontlist::AliasData> mAliasTable;
+  nsTHashMap<nsCStringHashKey, mozilla::fontlist::LocalFaceRec::InitData>
+      mLocalNameTable;
+
+  nsRefPtrHashtable<nsPtrHashKey<const mozilla::fontlist::Face>, gfxFontEntry>
+      mFontEntries MOZ_GUARDED_BY(mLock);
+
+  mozilla::UniquePtr<FontPrefs> mFontPrefs;
+
+  RefPtr<gfxFontEntry> mDefaultFontEntry MOZ_GUARDED_BY(mLock);
+
+  RefPtr<mozilla::CancelableRunnable> mLoadCmapsRunnable;
+  uint32_t mStartedLoadingCmapsFrom MOZ_GUARDED_BY(mLock) = 0xffffffffu;
+
+  bool mFontFamilyWhitelistActive = false;
+
+  static PRThread* sInitFontListThread;
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(gfxPlatformFontList::FindFamiliesFlags)
+
+#endif /* GFXPLATFORMFONTLIST_H_ */