Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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
/*
* JS atom table.
*/
#include "vm/JSAtomUtils-inl.h"
#include "mozilla/HashFunctions.h" // mozilla::HashStringKnownLength
#include "mozilla/RangedPtr.h"
#include <iterator>
#include <string.h>
#include "jstypes.h"
#include "frontend/CompilationStencil.h"
#include "gc/GC.h"
#include "gc/Marking.h"
#include "gc/MaybeRooted.h"
#include "js/CharacterEncoding.h"
#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_*
#include "js/Symbol.h"
#include "util/Text.h"
#include "vm/JSContext.h"
#include "vm/JSObject.h"
#include "vm/StaticStrings.h"
#include "vm/StringType.h"
#include "vm/SymbolType.h"
#include "vm/WellKnownAtom.h" // WellKnownAtomInfo, WellKnownAtomId, wellKnownAtomInfos
#ifdef ENABLE_RECORD_TUPLE
# include "vm/RecordType.h"
# include "vm/TupleType.h"
#endif
#include "gc/AtomMarking-inl.h"
#include "vm/JSContext-inl.h"
#include "vm/Realm-inl.h"
#include "vm/StringType-inl.h"
using namespace js;
using mozilla::Maybe;
using mozilla::Nothing;
using mozilla::RangedPtr;
template <typename CharT>
extern void InflateUTF8CharsToBuffer(const JS::UTF8Chars& src, CharT* dst,
size_t dstLen,
JS::SmallestEncoding encoding);
template <typename CharT>
extern bool UTF8EqualsChars(const JS::UTF8Chars& utf8, const CharT* chars);
extern bool GetUTF8AtomizationData(JSContext* cx, const JS::UTF8Chars& utf8,
size_t* outlen,
JS::SmallestEncoding* encoding,
HashNumber* hashNum);
MOZ_ALWAYS_INLINE bool js::AtomHasher::Lookup::StringsMatch(
const JSAtom& atom) const {
if (atom.hasLatin1Chars()) {
const Latin1Char* keyChars = atom.latin1Chars(nogc);
switch (type) {
case Lookup::Latin1:
return EqualChars(keyChars, latin1Chars, length);
case Lookup::TwoByteChar:
return EqualChars(keyChars, twoByteChars, length);
case Lookup::UTF8: {
JS::UTF8Chars utf8(utf8Bytes, byteLength);
return UTF8EqualsChars(utf8, keyChars);
}
}
}
const char16_t* keyChars = atom.twoByteChars(nogc);
switch (type) {
case Lookup::Latin1:
return EqualChars(latin1Chars, keyChars, length);
case Lookup::TwoByteChar:
return EqualChars(keyChars, twoByteChars, length);
case Lookup::UTF8: {
JS::UTF8Chars utf8(utf8Bytes, byteLength);
return UTF8EqualsChars(utf8, keyChars);
}
}
MOZ_ASSERT_UNREACHABLE("AtomHasher::match unknown type");
return false;
}
inline HashNumber js::AtomHasher::hash(const Lookup& l) { return l.hash; }
MOZ_ALWAYS_INLINE bool js::AtomHasher::match(const WeakHeapPtr<JSAtom*>& entry,
const Lookup& lookup) {
JSAtom* key = entry.unbarrieredGet();
if (lookup.atom) {
return lookup.atom == key;
}
if (key->length() != lookup.length || key->hash() != lookup.hash) {
return false;
}
return lookup.StringsMatch(*key);
}
UniqueChars js::AtomToPrintableString(JSContext* cx, JSAtom* atom) {
return QuoteString(cx, atom);
}
// Use a low initial capacity for the permanent atoms table to avoid penalizing
// runtimes that create a small number of atoms.
static const uint32_t JS_PERMANENT_ATOM_SIZE = 64;
MOZ_ALWAYS_INLINE AtomSet::Ptr js::FrozenAtomSet::readonlyThreadsafeLookup(
const AtomSet::Lookup& l) const {
return mSet->readonlyThreadsafeLookup(l);
}
static JSAtom* PermanentlyAtomizeCharsValidLength(JSContext* cx,
AtomSet& atomSet,
mozilla::HashNumber hash,
const Latin1Char* chars,
size_t length);
bool JSRuntime::initializeAtoms(JSContext* cx) {
JS::AutoAssertNoGC nogc;
MOZ_ASSERT(!atoms_);
MOZ_ASSERT(!permanentAtoms_);
if (parentRuntime) {
permanentAtoms_ = parentRuntime->permanentAtoms_;
staticStrings = parentRuntime->staticStrings;
commonNames = parentRuntime->commonNames;
emptyString = parentRuntime->emptyString;
wellKnownSymbols = parentRuntime->wellKnownSymbols;
atoms_ = js_new<AtomsTable>();
return bool(atoms_);
}
// NOTE: There's no GC, but `gc.freezePermanentSharedThings` below contains
// a function call that's marked as "Can GC".
Rooted<UniquePtr<AtomSet>> atomSet(cx,
cx->new_<AtomSet>(JS_PERMANENT_ATOM_SIZE));
if (!atomSet) {
return false;
}
staticStrings = js_new<StaticStrings>();
if (!staticStrings || !staticStrings->init(cx)) {
return false;
}
// The bare symbol names are already part of the well-known set, but their
// descriptions are not, so enumerate them here and add them to the initial
// permanent atoms set below.
static const WellKnownAtomInfo symbolDescInfo[] = {
#define COMMON_NAME_INFO(NAME) \
{uint32_t(sizeof("Symbol." #NAME) - 1), \
mozilla::HashStringKnownLength("Symbol." #NAME, \
sizeof("Symbol." #NAME) - 1), \
"Symbol." #NAME},
JS_FOR_EACH_WELL_KNOWN_SYMBOL(COMMON_NAME_INFO)
#undef COMMON_NAME_INFO
};
commonNames = js_new<JSAtomState>();
if (!commonNames) {
return false;
}
ImmutableTenuredPtr<PropertyName*>* names =
reinterpret_cast<ImmutableTenuredPtr<PropertyName*>*>(commonNames.ref());
for (size_t i = 0; i < uint32_t(WellKnownAtomId::Limit); i++) {
const auto& info = wellKnownAtomInfos[i];
JSAtom* atom = PermanentlyAtomizeCharsValidLength(
cx, *atomSet, info.hash,
reinterpret_cast<const Latin1Char*>(info.content), info.length);
if (!atom) {
return false;
}
names->init(atom->asPropertyName());
names++;
}
for (const auto& info : symbolDescInfo) {
JSAtom* atom = PermanentlyAtomizeCharsNonStaticValidLength(
cx, *atomSet, info.hash,
reinterpret_cast<const Latin1Char*>(info.content), info.length);
if (!atom) {
return false;
}
names->init(atom->asPropertyName());
names++;
}
MOZ_ASSERT(uintptr_t(names) == uintptr_t(commonNames + 1));
emptyString = commonNames->empty_;
// The self-hosted atoms are those that exist in a self-hosted JS source file,
// but are not defined in any of the well-known atom collections.
if (!cx->runtime()->selfHostStencil_->instantiateSelfHostedAtoms(
cx, *atomSet, cx->runtime()->selfHostStencilInput_->atomCache)) {
return false;
}
// Create the well-known symbols.
auto wks = js_new<WellKnownSymbols>();
if (!wks) {
return false;
}
{
// Prevent GC until we have fully initialized the well known symbols table.
// Faster than zeroing the array and null checking during every GC.
gc::AutoSuppressGC nogc(cx);
ImmutableTenuredPtr<PropertyName*>* descriptions =
commonNames->wellKnownSymbolDescriptions();
ImmutableTenuredPtr<JS::Symbol*>* symbols =
reinterpret_cast<ImmutableTenuredPtr<JS::Symbol*>*>(wks);
for (size_t i = 0; i < JS::WellKnownSymbolLimit; i++) {
JS::Symbol* symbol =
JS::Symbol::newWellKnown(cx, JS::SymbolCode(i), descriptions[i]);
if (!symbol) {
ReportOutOfMemory(cx);
return false;
}
symbols[i].init(symbol);
}
wellKnownSymbols = wks;
}
if (!gc.freezeSharedAtomsZone()) {
return false;
}
// The permanent atoms table has now been populated.
permanentAtoms_ =
js_new<FrozenAtomSet>(atomSet.release()); // Takes ownership.
if (!permanentAtoms_) {
return false;
}
// Initialize the main atoms table.
atoms_ = js_new<AtomsTable>();
if (!atoms_) {
return false;
}
return true;
}
void JSRuntime::finishAtoms() {
js_delete(atoms_.ref());
if (!parentRuntime) {
js_delete(permanentAtoms_.ref());
js_delete(staticStrings.ref());
js_delete(commonNames.ref());
js_delete(wellKnownSymbols.ref());
}
atoms_ = nullptr;
permanentAtoms_ = nullptr;
staticStrings = nullptr;
commonNames = nullptr;
wellKnownSymbols = nullptr;
emptyString = nullptr;
}
AtomsTable::AtomsTable()
: atoms(InitialTableSize), atomsAddedWhileSweeping(nullptr) {}
AtomsTable::~AtomsTable() { MOZ_ASSERT(!atomsAddedWhileSweeping); }
void AtomsTable::tracePinnedAtoms(JSTracer* trc) {
for (JSAtom* atom : pinnedAtoms) {
TraceRoot(trc, &atom, "pinned atom");
}
}
void js::TraceAtoms(JSTracer* trc) {
JSRuntime* rt = trc->runtime();
if (rt->permanentAtomsPopulated()) {
rt->atoms().tracePinnedAtoms(trc);
}
}
void AtomsTable::traceWeak(JSTracer* trc) {
for (AtomSet::Enum e(atoms); !e.empty(); e.popFront()) {
JSAtom* atom = e.front().unbarrieredGet();
MOZ_DIAGNOSTIC_ASSERT(atom);
if (!TraceManuallyBarrieredWeakEdge(trc, &atom, "AtomsTable::atoms")) {
e.removeFront();
} else {
MOZ_ASSERT(atom == e.front().unbarrieredGet());
}
}
}
bool AtomsTable::startIncrementalSweep(Maybe<SweepIterator>& atomsToSweepOut) {
MOZ_ASSERT(JS::RuntimeHeapIsCollecting());
MOZ_ASSERT(atomsToSweepOut.isNothing());
MOZ_ASSERT(!atomsAddedWhileSweeping);
atomsAddedWhileSweeping = js_new<AtomSet>();
if (!atomsAddedWhileSweeping) {
return false;
}
atomsToSweepOut.emplace(atoms);
return true;
}
void AtomsTable::mergeAtomsAddedWhileSweeping() {
// Add atoms that were added to the secondary table while we were sweeping
// the main table.
AutoEnterOOMUnsafeRegion oomUnsafe;
auto newAtoms = atomsAddedWhileSweeping;
atomsAddedWhileSweeping = nullptr;
for (auto r = newAtoms->all(); !r.empty(); r.popFront()) {
if (!atoms.putNew(AtomHasher::Lookup(r.front().unbarrieredGet()),
r.front())) {
oomUnsafe.crash("Adding atom from secondary table after sweep");
}
}
js_delete(newAtoms);
}
bool AtomsTable::sweepIncrementally(SweepIterator& atomsToSweep,
JS::SliceBudget& budget) {
// Sweep the table incrementally until we run out of work or budget.
while (!atomsToSweep.empty()) {
budget.step();
if (budget.isOverBudget()) {
return false;
}
JSAtom* atom = atomsToSweep.front().unbarrieredGet();
MOZ_DIAGNOSTIC_ASSERT(atom);
if (IsAboutToBeFinalizedUnbarriered(atom)) {
MOZ_ASSERT(!atom->isPinned());
atomsToSweep.removeFront();
} else {
MOZ_ASSERT(atom == atomsToSweep.front().unbarrieredGet());
}
atomsToSweep.popFront();
}
mergeAtomsAddedWhileSweeping();
return true;
}
size_t AtomsTable::sizeOfIncludingThis(
mozilla::MallocSizeOf mallocSizeOf) const {
size_t size = sizeof(AtomsTable);
size += atoms.shallowSizeOfExcludingThis(mallocSizeOf);
if (atomsAddedWhileSweeping) {
size += atomsAddedWhileSweeping->shallowSizeOfExcludingThis(mallocSizeOf);
}
size += pinnedAtoms.sizeOfExcludingThis(mallocSizeOf);
return size;
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom*
AtomizeAndCopyCharsNonStaticValidLengthFromLookup(
JSContext* cx, const CharT* chars, size_t length,
const AtomHasher::Lookup& lookup, const Maybe<uint32_t>& indexValue) {
Zone* zone = cx->zone();
MOZ_ASSERT(zone);
AtomCacheHashTable* atomCache = zone->atomCache();
// Try the per-Zone cache first. If we find the atom there we can avoid the
// markAtom call, and the multiple HashSet lookups below.
if (MOZ_LIKELY(atomCache)) {
JSAtom* const cachedAtom = atomCache->lookupForAdd(lookup);
if (cachedAtom) {
// The cache is purged on GC so if we're in the middle of an incremental
// GC we should have barriered the atom when we put it in the cache.
MOZ_ASSERT(AtomIsMarked(zone, cachedAtom));
return cachedAtom;
}
}
MOZ_ASSERT(cx->permanentAtomsPopulated());
AtomSet::Ptr pp = cx->permanentAtoms().readonlyThreadsafeLookup(lookup);
if (pp) {
JSAtom* atom = pp->get();
if (MOZ_LIKELY(atomCache)) {
atomCache->add(lookup.hash, atom);
}
return atom;
}
JSAtom* atom = cx->atoms().atomizeAndCopyCharsNonStaticValidLength(
cx, chars, length, indexValue, lookup);
if (!atom) {
return nullptr;
}
if (MOZ_UNLIKELY(!cx->atomMarking().inlinedMarkAtomFallible(cx, atom))) {
ReportOutOfMemory(cx);
return nullptr;
}
if (MOZ_LIKELY(atomCache)) {
atomCache->add(lookup.hash, atom);
}
return atom;
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* AllocateNewAtomNonStaticValidLength(
JSContext* cx, const CharT* chars, size_t length,
const Maybe<uint32_t>& indexValue, const AtomHasher::Lookup& lookup);
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* AllocateNewPermanentAtomNonStaticValidLength(
JSContext* cx, const CharT* chars, size_t length,
const AtomHasher::Lookup& lookup);
template <typename CharT>
MOZ_ALWAYS_INLINE JSAtom* AtomsTable::atomizeAndCopyCharsNonStaticValidLength(
JSContext* cx, const CharT* chars, size_t length,
const Maybe<uint32_t>& indexValue, const AtomHasher::Lookup& lookup) {
AtomSet::AddPtr p;
if (!atomsAddedWhileSweeping) {
p = atoms.lookupForAdd(lookup);
} else {
// We're currently sweeping the main atoms table and all new atoms will
// be added to a secondary table. Check this first.
p = atomsAddedWhileSweeping->lookupForAdd(lookup);
// If that fails check the main table but check if any atom found there
// is dead.
if (!p) {
if (AtomSet::AddPtr p2 = atoms.lookupForAdd(lookup)) {
JSAtom* atom = p2->unbarrieredGet();
if (!IsAboutToBeFinalizedUnbarriered(atom)) {
p = p2;
}
}
}
}
if (p) {
return p->get();
}
JSAtom* atom = AllocateNewAtomNonStaticValidLength(cx, chars, length,
indexValue, lookup);
if (!atom) {
return nullptr;
}
// The operations above can't GC; therefore the atoms table has not been
// modified and p is still valid.
AtomSet* addSet = atomsAddedWhileSweeping ? atomsAddedWhileSweeping : &atoms;
if (MOZ_UNLIKELY(!addSet->add(p, atom))) {
ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
return nullptr;
}
return atom;
}
/* |chars| must not point into an inline or short string. */
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* AtomizeAndCopyChars(
JSContext* cx, const CharT* chars, size_t length,
const Maybe<uint32_t>& indexValue, const Maybe<js::HashNumber>& hash) {
if (JSAtom* s = cx->staticStrings().lookup(chars, length)) {
return s;
}
if (MOZ_UNLIKELY(!JSString::validateLength(cx, length))) {
return nullptr;
}
if (hash.isSome()) {
AtomHasher::Lookup lookup(hash.value(), chars, length);
return AtomizeAndCopyCharsNonStaticValidLengthFromLookup(
cx, chars, length, lookup, indexValue);
}
AtomHasher::Lookup lookup(chars, length);
return AtomizeAndCopyCharsNonStaticValidLengthFromLookup(cx, chars, length,
lookup, indexValue);
}
template <typename CharT>
static MOZ_NEVER_INLINE JSAtom*
PermanentlyAtomizeAndCopyCharsNonStaticValidLength(
JSContext* cx, AtomSet& atomSet, const CharT* chars, size_t length,
const AtomHasher::Lookup& lookup) {
MOZ_ASSERT(!cx->permanentAtomsPopulated());
MOZ_ASSERT(CurrentThreadCanAccessRuntime(cx->runtime()));
AtomSet::AddPtr p = atomSet.lookupForAdd(lookup);
if (p) {
return p->get();
}
JSAtom* atom =
AllocateNewPermanentAtomNonStaticValidLength(cx, chars, length, lookup);
if (!atom) {
return nullptr;
}
// We are single threaded at this point, and the operations we've done since
// then can't GC; therefore the atoms table has not been modified and p is
// still valid.
if (!atomSet.add(p, atom)) {
ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
return nullptr;
}
return atom;
}
struct AtomizeUTF8CharsWrapper {
JS::UTF8Chars utf8;
JS::SmallestEncoding encoding;
AtomizeUTF8CharsWrapper(const JS::UTF8Chars& chars,
JS::SmallestEncoding minEncode)
: utf8(chars), encoding(minEncode) {}
};
// NewAtomNonStaticValidLength has 3 variants.
// This is used by Latin1Char and char16_t.
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* NewAtomNonStaticValidLength(
JSContext* cx, const CharT* chars, size_t length, js::HashNumber hash) {
return NewAtomCopyNMaybeDeflateValidLength(cx, chars, length, hash);
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* MakeUTF8AtomHelperNonStaticValidLength(
JSContext* cx, const AtomizeUTF8CharsWrapper* chars, size_t length,
js::HashNumber hash) {
if (JSAtom::lengthFitsInline<CharT>(length)) {
CharT* storage;
JSAtom* str = AllocateInlineAtom(cx, length, &storage, hash);
if (!str) {
return nullptr;
}
InflateUTF8CharsToBuffer(chars->utf8, storage, length, chars->encoding);
return str;
}
// MakeAtomUTF8Helper is called from deep in the Atomization path, which
// expects functions to fail gracefully with nullptr on OOM, without throwing.
JSString::OwnedChars<CharT> newChars(
AllocAtomCharsValidLength<CharT>(cx, length));
if (!newChars) {
return nullptr;
}
InflateUTF8CharsToBuffer(chars->utf8, newChars.data(), length,
chars->encoding);
return JSAtom::newValidLength<CharT>(cx, newChars, hash);
}
// Another variant of NewAtomNonStaticValidLength.
static MOZ_ALWAYS_INLINE JSAtom* NewAtomNonStaticValidLength(
JSContext* cx, const AtomizeUTF8CharsWrapper* chars, size_t length,
js::HashNumber hash) {
if (length == 0) {
return cx->emptyString();
}
if (chars->encoding == JS::SmallestEncoding::UTF16) {
return MakeUTF8AtomHelperNonStaticValidLength<char16_t>(cx, chars, length,
hash);
}
return MakeUTF8AtomHelperNonStaticValidLength<JS::Latin1Char>(cx, chars,
length, hash);
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* AllocateNewAtomNonStaticValidLength(
JSContext* cx, const CharT* chars, size_t length,
const Maybe<uint32_t>& indexValue, const AtomHasher::Lookup& lookup) {
AutoAllocInAtomsZone ac(cx);
JSAtom* atom = NewAtomNonStaticValidLength(cx, chars, length, lookup.hash);
if (!atom) {
// Grudgingly forgo last-ditch GC. The alternative would be to manually GC
// here, and retry from the top.
ReportOutOfMemory(cx);
return nullptr;
}
MOZ_ASSERT(atom->hash() == lookup.hash);
if (indexValue) {
atom->setIsIndex(*indexValue);
} else {
// We need to call isIndexSlow directly to avoid the flag check in isIndex,
// because we still have to initialize that flag.
uint32_t index;
if (atom->isIndexSlow(&index)) {
atom->setIsIndex(index);
}
}
return atom;
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* AllocateNewPermanentAtomNonStaticValidLength(
JSContext* cx, const CharT* chars, size_t length,
const AtomHasher::Lookup& lookup) {
AutoAllocInAtomsZone ac(cx);
#ifdef DEBUG
if constexpr (std::is_same_v<CharT, char16_t>) {
// Can call DontDeflate variant.
MOZ_ASSERT(!CanStoreCharsAsLatin1(chars, length));
}
#endif
JSAtom* atom =
NewAtomCopyNDontDeflateValidLength(cx, chars, length, lookup.hash);
if (!atom) {
// Do not bother with a last-ditch GC here since we are very early in
// startup and there is no potential garbage to collect.
ReportOutOfMemory(cx);
return nullptr;
}
atom->makePermanent();
MOZ_ASSERT(atom->hash() == lookup.hash);
uint32_t index;
if (atom->isIndexSlow(&index)) {
atom->setIsIndex(index);
}
return atom;
}
JSAtom* js::AtomizeStringSlow(JSContext* cx, JSString* str) {
MOZ_ASSERT(!str->isAtom());
if (str->isAtomRef()) {
return str->atom();
}
if (JSAtom* atom = cx->caches().stringToAtomCache.lookup(str)) {
return atom;
}
JS::Latin1Char flattenRope[StringToAtomCache::MinStringLength];
mozilla::Maybe<StringToAtomCache::AtomTableKey> key;
size_t length = str->length();
if (str->isRope() && length < StringToAtomCache::MinStringLength &&
str->hasLatin1Chars()) {
StringSegmentRange<StringToAtomCache::MinStringLength> iter(cx);
if (iter.init(str)) {
size_t index = 0;
do {
const JSLinearString* s = iter.front();
CopyChars(flattenRope + index, *s);
index += s->length();
} while (iter.popFront() && !iter.empty());
if (JSAtom* atom = cx->caches().stringToAtomCache.lookupWithRopeChars(
flattenRope, length, key)) {
// Since this cache lookup is based on a string comparison, not object
// identity, need to mark atom explicitly in this case. And this is
// not done in lookup() itself, because #including JSContext.h there
// causes some non-trivial #include ordering issues.
cx->markAtom(atom);
str->tryReplaceWithAtomRef(atom);
return atom;
}
}
}
Maybe<uint32_t> indexValue;
if (str->hasIndexValue()) {
indexValue.emplace(str->getIndexValue());
}
JSAtom* atom = nullptr;
if (key.isSome()) {
atom = AtomizeAndCopyChars(cx, key.value().string_, key.value().length_,
indexValue, mozilla::Some(key.value().hash_));
} else {
JSLinearString* linear = str->ensureLinear(cx);
if (!linear) {
return nullptr;
}
JS::AutoCheckCannotGC nogc;
atom = linear->hasLatin1Chars()
? AtomizeAndCopyChars(cx, linear->latin1Chars(nogc),
linear->length(), indexValue, Nothing())
: AtomizeAndCopyChars(cx, linear->twoByteChars(nogc),
linear->length(), indexValue, Nothing());
}
if (!atom) {
return nullptr;
}
if (!str->tryReplaceWithAtomRef(atom)) {
cx->caches().stringToAtomCache.maybePut(str, atom, key);
}
return atom;
}
bool js::AtomIsPinned(JSContext* cx, JSAtom* atom) { return atom->isPinned(); }
bool js::PinAtom(JSContext* cx, JSAtom* atom) {
JS::AutoCheckCannotGC nogc;
return cx->runtime()->atoms().maybePinExistingAtom(cx, atom);
}
bool AtomsTable::maybePinExistingAtom(JSContext* cx, JSAtom* atom) {
MOZ_ASSERT(atom);
if (atom->isPinned()) {
return true;
}
if (!pinnedAtoms.append(atom)) {
return false;
}
atom->setPinned();
return true;
}
JSAtom* js::Atomize(JSContext* cx, const char* bytes, size_t length,
const Maybe<uint32_t>& indexValue) {
const Latin1Char* chars = reinterpret_cast<const Latin1Char*>(bytes);
return AtomizeAndCopyChars(cx, chars, length, indexValue, Nothing());
}
template <typename CharT>
JSAtom* js::AtomizeChars(JSContext* cx, const CharT* chars, size_t length) {
return AtomizeAndCopyChars(cx, chars, length, Nothing(), Nothing());
}
template JSAtom* js::AtomizeChars(JSContext* cx, const Latin1Char* chars,
size_t length);
template JSAtom* js::AtomizeChars(JSContext* cx, const char16_t* chars,
size_t length);
JSAtom* js::AtomizeWithoutActiveZone(JSContext* cx, const char* bytes,
size_t length) {
// This is used to implement JS_AtomizeAndPinString{N} when called without an
// active zone. This simplifies the normal atomization code because it can
// assume a non-null cx->zone().
MOZ_ASSERT(!cx->zone());
MOZ_ASSERT(cx->permanentAtomsPopulated());
const Latin1Char* chars = reinterpret_cast<const Latin1Char*>(bytes);
if (JSAtom* s = cx->staticStrings().lookup(chars, length)) {
return s;
}
if (MOZ_UNLIKELY(!JSString::validateLength(cx, length))) {
return nullptr;
}
AtomHasher::Lookup lookup(chars, length);
if (AtomSet::Ptr pp = cx->permanentAtoms().readonlyThreadsafeLookup(lookup)) {
return pp->get();
}
return cx->atoms().atomizeAndCopyCharsNonStaticValidLength(cx, chars, length,
Nothing(), lookup);
}
/* |chars| must not point into an inline or short string. */
template <typename CharT>
JSAtom* js::AtomizeCharsNonStaticValidLength(JSContext* cx, HashNumber hash,
const CharT* chars,
size_t length) {
MOZ_ASSERT(!cx->staticStrings().lookup(chars, length));
AtomHasher::Lookup lookup(hash, chars, length);
return AtomizeAndCopyCharsNonStaticValidLengthFromLookup(cx, chars, length,
lookup, Nothing());
}
template JSAtom* js::AtomizeCharsNonStaticValidLength(JSContext* cx,
HashNumber hash,
const Latin1Char* chars,
size_t length);
template JSAtom* js::AtomizeCharsNonStaticValidLength(JSContext* cx,
HashNumber hash,
const char16_t* chars,
size_t length);
static JSAtom* PermanentlyAtomizeCharsValidLength(JSContext* cx,
AtomSet& atomSet,
HashNumber hash,
const Latin1Char* chars,
size_t length) {
if (JSAtom* s = cx->staticStrings().lookup(chars, length)) {
return s;
}
return PermanentlyAtomizeCharsNonStaticValidLength(cx, atomSet, hash, chars,
length);
}
JSAtom* js::PermanentlyAtomizeCharsNonStaticValidLength(JSContext* cx,
AtomSet& atomSet,
HashNumber hash,
const Latin1Char* chars,
size_t length) {
MOZ_ASSERT(!cx->staticStrings().lookup(chars, length));
MOZ_ASSERT(length <= JSString::MAX_LENGTH);
AtomHasher::Lookup lookup(hash, chars, length);
return PermanentlyAtomizeAndCopyCharsNonStaticValidLength(cx, atomSet, chars,
length, lookup);
}
JSAtom* js::AtomizeUTF8Chars(JSContext* cx, const char* utf8Chars,
size_t utf8ByteLength) {
{
StaticStrings& statics = cx->staticStrings();
// Handle all pure-ASCII UTF-8 static strings.
if (JSAtom* s = statics.lookup(utf8Chars, utf8ByteLength)) {
return s;
}
// The only non-ASCII static strings are the single-code point strings
// U+0080 through U+00FF, encoded as
//
// 0b1100'00xx 0b10xx'xxxx
//
// where the encoded code point is the concatenation of the 'x' bits -- and
// where the highest 'x' bit is necessarily 1 (because U+0080 through U+00FF
// all contain an 0x80 bit).
if (utf8ByteLength == 2) {
auto first = static_cast<uint8_t>(utf8Chars[0]);
if ((first & 0b1111'1110) == 0b1100'0010) {
auto second = static_cast<uint8_t>(utf8Chars[1]);
if (mozilla::IsTrailingUnit(mozilla::Utf8Unit(second))) {
uint8_t unit =
static_cast<uint8_t>(first << 6) | (second & 0b0011'1111);
MOZ_ASSERT(StaticStrings::hasUnit(unit));
return statics.getUnit(unit);
}
}
// Fallthrough code handles the cases where the two units aren't a Latin-1
// code point or are invalid.
}
}
size_t length;
HashNumber hash;
JS::SmallestEncoding forCopy;
JS::UTF8Chars utf8(utf8Chars, utf8ByteLength);
if (!GetUTF8AtomizationData(cx, utf8, &length, &forCopy, &hash)) {
return nullptr;
}
if (MOZ_UNLIKELY(!JSString::validateLength(cx, length))) {
return nullptr;
}
AtomizeUTF8CharsWrapper chars(utf8, forCopy);
AtomHasher::Lookup lookup(utf8Chars, utf8ByteLength, length, hash);
return AtomizeAndCopyCharsNonStaticValidLengthFromLookup(cx, &chars, length,
lookup, Nothing());
}
bool js::IndexToIdSlow(JSContext* cx, uint32_t index, MutableHandleId idp) {
MOZ_ASSERT(index > JS::PropertyKey::IntMax);
char16_t buf[UINT32_CHAR_BUFFER_LENGTH];
RangedPtr<char16_t> end(std::end(buf), buf, std::end(buf));
RangedPtr<char16_t> start = BackfillIndexInCharBuffer(index, end);
JSAtom* atom = AtomizeChars(cx, start.get(), end - start);
if (!atom) {
return false;
}
idp.set(JS::PropertyKey::NonIntAtom(atom));
return true;
}
template <AllowGC allowGC>
static MOZ_ALWAYS_INLINE JSAtom* PrimitiveToAtom(JSContext* cx,
const Value& v) {
MOZ_ASSERT(v.isPrimitive());
switch (v.type()) {
case ValueType::String: {
JSAtom* atom = AtomizeString(cx, v.toString());
if (!allowGC && !atom) {
cx->recoverFromOutOfMemory();
}
return atom;
}
case ValueType::Int32: {
JSAtom* atom = Int32ToAtom(cx, v.toInt32());
if (!allowGC && !atom) {
cx->recoverFromOutOfMemory();
}
return atom;
}
case ValueType::Double: {
JSAtom* atom = NumberToAtom(cx, v.toDouble());
if (!allowGC && !atom) {
cx->recoverFromOutOfMemory();
}
return atom;
}
case ValueType::Boolean:
return v.toBoolean() ? cx->names().true_ : cx->names().false_;
case ValueType::Null:
return cx->names().null;
case ValueType::Undefined:
return cx->names().undefined;
case ValueType::Symbol:
if constexpr (allowGC) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_SYMBOL_TO_STRING);
}
return nullptr;
case ValueType::BigInt: {
RootedBigInt i(cx, v.toBigInt());
return BigIntToAtom<allowGC>(cx, i);
}
#ifdef ENABLE_RECORD_TUPLE
case ValueType::ExtendedPrimitive:
#endif
case ValueType::Object:
case ValueType::Magic:
case ValueType::PrivateGCThing:
break;
}
MOZ_CRASH("Unexpected type");
}
template <AllowGC allowGC>
static JSAtom* ToAtomSlow(
JSContext* cx, typename MaybeRooted<Value, allowGC>::HandleType arg) {
MOZ_ASSERT(!arg.isString());
Value v = arg;
if (!v.isPrimitive()) {
if (!allowGC) {
return nullptr;
}
RootedValue v2(cx, v);
if (!ToPrimitive(cx, JSTYPE_STRING, &v2)) {
return nullptr;
}
v = v2;
}
return PrimitiveToAtom<allowGC>(cx, v);
}
template <AllowGC allowGC>
JSAtom* js::ToAtom(JSContext* cx,
typename MaybeRooted<Value, allowGC>::HandleType v) {
if (!v.isString()) {
return ToAtomSlow<allowGC>(cx, v);
}
JSAtom* atom = AtomizeString(cx, v.toString());
if (!atom && !allowGC) {
MOZ_ASSERT(cx->isThrowingOutOfMemory());
cx->recoverFromOutOfMemory();
}
return atom;
}
template JSAtom* js::ToAtom<CanGC>(JSContext* cx, HandleValue v);
template JSAtom* js::ToAtom<NoGC>(JSContext* cx, const Value& v);
template <AllowGC allowGC>
bool js::PrimitiveValueToIdSlow(
JSContext* cx, typename MaybeRooted<Value, allowGC>::HandleType v,
typename MaybeRooted<jsid, allowGC>::MutableHandleType idp) {
MOZ_ASSERT(v.isPrimitive());
MOZ_ASSERT(!v.isString());
MOZ_ASSERT(!v.isSymbol());
MOZ_ASSERT_IF(v.isInt32(), !PropertyKey::fitsInInt(v.toInt32()));
int32_t i;
if (v.isDouble() && mozilla::NumberEqualsInt32(v.toDouble(), &i) &&
PropertyKey::fitsInInt(i)) {
idp.set(PropertyKey::Int(i));
return true;
}
JSAtom* atom = PrimitiveToAtom<allowGC>(cx, v);
if (!atom) {
return false;
}
idp.set(AtomToId(atom));
return true;
}
template bool js::PrimitiveValueToIdSlow<CanGC>(JSContext* cx, HandleValue v,
MutableHandleId idp);
template bool js::PrimitiveValueToIdSlow<NoGC>(JSContext* cx, const Value& v,
FakeMutableHandle<jsid> idp);
#ifdef ENABLE_RECORD_TUPLE
bool js::EnsureAtomized(JSContext* cx, MutableHandleValue v, bool* updated) {
if (v.isString()) {
if (v.toString()->isAtom()) {
*updated = false;
return true;
}
JSAtom* atom = AtomizeString(cx, v.toString());
if (!atom) {
return false;
}
v.setString(atom);
*updated = true;
return true;
}
*updated = false;
if (v.isExtendedPrimitive()) {
JSObject& obj = v.toExtendedPrimitive();
if (obj.is<RecordType>()) {
return obj.as<RecordType>().ensureAtomized(cx);
}
MOZ_ASSERT(obj.is<TupleType>());
return obj.as<TupleType>().ensureAtomized(cx);
}
return true;
}
#endif
Handle<PropertyName*> js::ClassName(JSProtoKey key, JSContext* cx) {
return ClassName(key, cx->names());
}