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
#ifndef vm_StringType_inl_h
#define vm_StringType_inl_h
#include "vm/StringType.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Range.h"
#include "mozilla/StringBuffer.h"
#include "gc/GCEnum.h"
#include "gc/MaybeRooted.h"
#include "gc/StoreBuffer.h"
#include "js/UniquePtr.h"
#include "vm/StaticStrings.h"
#include "gc/GCContext-inl.h"
#include "gc/Marking-inl.h"
#include "gc/StoreBuffer-inl.h"
#include "vm/JSContext-inl.h"
namespace js {
// Allocate a thin inline string if possible, and a fat inline string if not.
template <AllowGC allowGC, typename CharT>
static MOZ_ALWAYS_INLINE JSInlineString* AllocateInlineString(
JSContext* cx, size_t len, CharT** chars, js::gc::Heap heap) {
MOZ_ASSERT(JSInlineString::lengthFits<CharT>(len));
if (JSThinInlineString::lengthFits<CharT>(len)) {
return cx->newCell<JSThinInlineString, allowGC>(heap, len, chars);
}
return cx->newCell<JSFatInlineString, allowGC>(heap, len, chars);
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* AllocateInlineAtom(JSContext* cx, size_t len,
CharT** chars,
js::HashNumber hash) {
MOZ_ASSERT(JSAtom::lengthFitsInline<CharT>(len));
if constexpr (js::ThinInlineAtom::EverInstantiated) {
if (js::ThinInlineAtom::lengthFits<CharT>(len)) {
return cx->newCell<js::ThinInlineAtom, js::NoGC>(len, chars, hash);
}
}
return cx->newCell<js::FatInlineAtom, js::NoGC>(len, chars, hash);
}
// Create a thin inline string if possible, and a fat inline string if not.
template <AllowGC allowGC, typename CharT>
static MOZ_ALWAYS_INLINE JSInlineString* NewInlineString(
JSContext* cx, mozilla::Range<const CharT> chars,
js::gc::Heap heap = js::gc::Heap::Default) {
/*
* Don't bother trying to find a static atom; measurement shows that not
* many get here (for one, Atomize is catching them).
*/
size_t len = chars.length();
CharT* storage;
JSInlineString* str = AllocateInlineString<allowGC>(cx, len, &storage, heap);
if (!str) {
return nullptr;
}
mozilla::PodCopy(storage, chars.begin().get(), len);
return str;
}
// Create a thin inline string if possible, and a fat inline string if not.
template <AllowGC allowGC, typename CharT, size_t N>
static MOZ_ALWAYS_INLINE JSInlineString* NewInlineString(
JSContext* cx, const CharT (&chars)[N], size_t len,
js::gc::Heap heap = js::gc::Heap::Default) {
MOZ_ASSERT(len <= N);
/*
* Don't bother trying to find a static atom; measurement shows that not
* many get here (for one, Atomize is catching them).
*/
CharT* storage;
JSInlineString* str = AllocateInlineString<allowGC>(cx, len, &storage, heap);
if (!str) {
return nullptr;
}
if (JSThinInlineString::lengthFits<CharT>(len)) {
constexpr size_t MaxLength = std::is_same_v<CharT, Latin1Char>
? JSThinInlineString::MAX_LENGTH_LATIN1
: JSThinInlineString::MAX_LENGTH_TWO_BYTE;
// memcpy with a constant length can be optimized more easily by compilers.
constexpr size_t toCopy = std::min(N, MaxLength) * sizeof(CharT);
std::memcpy(storage, chars, toCopy);
} else {
constexpr size_t MaxLength = std::is_same_v<CharT, Latin1Char>
? JSFatInlineString::MAX_LENGTH_LATIN1
: JSFatInlineString::MAX_LENGTH_TWO_BYTE;
// memcpy with a constant length can be optimized more easily by compilers.
constexpr size_t toCopy = std::min(N, MaxLength) * sizeof(CharT);
std::memcpy(storage, chars, toCopy);
}
return str;
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSAtom* NewInlineAtom(JSContext* cx,
const CharT* chars,
size_t length,
js::HashNumber hash) {
CharT* storage;
JSAtom* str = AllocateInlineAtom(cx, length, &storage, hash);
if (!str) {
return nullptr;
}
mozilla::PodCopy(storage, chars, length);
return str;
}
// Create a thin inline string if possible, and a fat inline string if not.
template <typename CharT>
static MOZ_ALWAYS_INLINE JSInlineString* NewInlineString(
JSContext* cx, Handle<JSLinearString*> base, size_t start, size_t length,
js::gc::Heap heap) {
MOZ_ASSERT(JSInlineString::lengthFits<CharT>(length));
CharT* chars;
JSInlineString* s = AllocateInlineString<CanGC>(cx, length, &chars, heap);
if (!s) {
return nullptr;
}
JS::AutoCheckCannotGC nogc;
mozilla::PodCopy(chars, base->chars<CharT>(nogc) + start, length);
return s;
}
template <typename CharT>
static MOZ_ALWAYS_INLINE JSLinearString* TryEmptyOrStaticString(
JSContext* cx, const CharT* chars, size_t n) {
// Measurements on popular websites indicate empty strings are pretty common
// and most strings with length 1 or 2 are in the StaticStrings table. For
// length 3 strings that's only about 1%, so we check n <= 2.
if (n <= 2) {
if (n == 0) {
return cx->emptyString();
}
if (JSLinearString* str = cx->staticStrings().lookup(chars, n)) {
return str;
}
}
return nullptr;
}
} /* namespace js */
template <typename CharT>
JSString::OwnedChars<CharT>::OwnedChars(CharT* chars, size_t length, Kind kind)
: chars_(chars, length), kind_(kind) {
MOZ_ASSERT(kind != Kind::Uninitialized);
MOZ_ASSERT(length > 0);
MOZ_ASSERT(chars);
#ifdef DEBUG
bool inNursery = js::TlsContext.get()->nursery().isInside(chars);
MOZ_ASSERT((kind == Kind::Nursery) == inNursery);
#endif
}
template <typename CharT>
JSString::OwnedChars<CharT>::OwnedChars(JSString::OwnedChars<CharT>&& other)
: chars_(other.chars_), kind_(other.kind_) {
other.release();
}
template <typename CharT>
CharT* JSString::OwnedChars<CharT>::release() {
CharT* chars = chars_.data();
chars_ = {};
kind_ = Kind::Uninitialized;
return chars;
}
template <typename CharT>
void JSString::OwnedChars<CharT>::reset() {
switch (kind_) {
case Kind::Uninitialized:
case Kind::Nursery:
break;
case Kind::Malloc:
js_free(chars_.data());
break;
case Kind::StringBuffer:
mozilla::StringBuffer::FromData(chars_.data())->Release();
break;
}
chars_ = {};
kind_ = Kind::Uninitialized;
}
template <typename CharT>
void JSString::OwnedChars<CharT>::ensureNonNursery() {
if (kind_ != Kind::Nursery) {
return;
}
js::AutoEnterOOMUnsafeRegion oomUnsafe;
CharT* oldPtr = data();
size_t length = chars_.Length();
CharT* ptr = js_pod_arena_malloc<CharT>(js::StringBufferArena, length);
if (!ptr) {
oomUnsafe.crash(chars_.size(), "moving nursery buffer to heap");
}
mozilla::PodCopy(ptr, oldPtr, length);
chars_ = mozilla::Span<CharT>(ptr, length);
kind_ = Kind::Malloc;
}
template <typename CharT>
JSString::OwnedChars<CharT>::OwnedChars(
js::UniquePtr<CharT[], JS::FreePolicy>&& chars, size_t length)
: OwnedChars(chars.release(), length, Kind::Malloc) {}
template <typename CharT>
JSString::OwnedChars<CharT>::OwnedChars(RefPtr<mozilla::StringBuffer>&& buffer,
size_t length)
: OwnedChars(static_cast<CharT*>(buffer->Data()), length,
Kind::StringBuffer) {
// Transfer the reference from |buffer| to this OwnedChars.
mozilla::StringBuffer* buf;
buffer.forget(&buf);
}
MOZ_ALWAYS_INLINE bool JSString::validateLength(JSContext* maybecx,
size_t length) {
return validateLengthInternal<js::CanGC>(maybecx, length);
}
template <js::AllowGC allowGC>
MOZ_ALWAYS_INLINE bool JSString::validateLengthInternal(JSContext* maybecx,
size_t length) {
if (MOZ_UNLIKELY(length > JSString::MAX_LENGTH)) {
if constexpr (allowGC) {
js::ReportOversizedAllocation(maybecx, JSMSG_ALLOC_OVERFLOW);
}
return false;
}
return true;
}
template <>
MOZ_ALWAYS_INLINE const char16_t* JSString::nonInlineCharsRaw() const {
return d.s.u2.nonInlineCharsTwoByte;
}
template <>
MOZ_ALWAYS_INLINE const JS::Latin1Char* JSString::nonInlineCharsRaw() const {
return d.s.u2.nonInlineCharsLatin1;
}
bool JSString::ownsMallocedChars() const {
if (!hasOutOfLineChars() || asLinear().hasStringBuffer()) {
return false;
}
js::gc::StoreBuffer* sb = storeBuffer();
if (!sb) {
// Tenured strings always own out-of-line chars.
return true;
}
// Return whether the chars are malloced. Note: this allows the data to be in
// a different nursery chunk than the Cell itself, at the performance cost of
// iterating over all chunks.
return !sb->nursery().isInside(asLinear().nonInlineCharsRaw());
}
template <typename CharT>
inline size_t JSLinearString::maybeMallocCharsOnPromotion(
js::Nursery* nursery) {
const void** chars;
if constexpr (std::is_same_v<CharT, char16_t>) {
chars = reinterpret_cast<const void**>(&d.s.u2.nonInlineCharsTwoByte);
} else {
chars = reinterpret_cast<const void**>(&d.s.u2.nonInlineCharsLatin1);
}
size_t nbytes = length() * sizeof(CharT);
if (nursery->maybeMoveBufferOnPromotion(const_cast<void**>(chars), this,
nbytes, js::MemoryUse::StringContents,
js::StringBufferArena) ==
js::Nursery::BufferMoved) {
return nbytes;
}
return 0;
}
inline size_t JSLinearString::allocSize() const {
MOZ_ASSERT(ownsMallocedChars() || hasStringBuffer());
size_t charSize =
hasLatin1Chars() ? sizeof(JS::Latin1Char) : sizeof(char16_t);
size_t count = isExtensible() ? asExtensible().capacity() : length();
return count * charSize;
}
inline size_t JSString::allocSize() const {
if (ownsMallocedChars() || hasStringBuffer()) {
return asLinear().allocSize();
}
return 0;
}
inline JSRope::JSRope(JSString* left, JSString* right, size_t length) {
// JITs expect rope children aren't empty.
MOZ_ASSERT(!left->empty() && !right->empty());
// |length| must be the sum of the length of both child nodes.
MOZ_ASSERT(left->length() + right->length() == length);
// |isLatin1| is set when both children are guaranteed to contain only Latin-1
// characters. Note that flattening either rope child can clear the Latin-1
// flag of that child, so it's possible that a Latin-1 rope can end up with
// both children being two-byte (dependent) strings.
bool isLatin1 = left->hasLatin1Chars() && right->hasLatin1Chars();
// Do not try to make a rope that could fit inline.
MOZ_ASSERT_IF(!isLatin1, !JSInlineString::lengthFits<char16_t>(length));
MOZ_ASSERT_IF(isLatin1, !JSInlineString::lengthFits<JS::Latin1Char>(length));
if (isLatin1) {
setLengthAndFlags(length, INIT_ROPE_FLAGS | LATIN1_CHARS_BIT);
} else {
setLengthAndFlags(length, INIT_ROPE_FLAGS);
}
d.s.u2.left = left;
d.s.u3.right = right;
// Post-barrier by inserting into the whole cell buffer if either
// this -> left or this -> right is a tenured -> nursery edge.
if (isTenured()) {
js::gc::StoreBuffer* sb = left->storeBuffer();
if (!sb) {
sb = right->storeBuffer();
}
if (sb) {
sb->putWholeCell(this);
}
}
}
template <js::AllowGC allowGC>
MOZ_ALWAYS_INLINE JSRope* JSRope::new_(
JSContext* cx,
typename js::MaybeRooted<JSString*, allowGC>::HandleType left,
typename js::MaybeRooted<JSString*, allowGC>::HandleType right,
size_t length, js::gc::Heap heap) {
if (MOZ_UNLIKELY(!validateLengthInternal<allowGC>(cx, length))) {
return nullptr;
}
return cx->newCell<JSRope, allowGC>(heap, left, right, length);
}
inline JSDependentString::JSDependentString(JSLinearString* base, size_t start,
size_t length) {
MOZ_ASSERT(start + length <= base->length());
JS::AutoCheckCannotGC nogc;
if (base->hasLatin1Chars()) {
setLengthAndFlags(length, INIT_DEPENDENT_FLAGS | LATIN1_CHARS_BIT);
d.s.u2.nonInlineCharsLatin1 = base->latin1Chars(nogc) + start;
} else {
setLengthAndFlags(length, INIT_DEPENDENT_FLAGS);
d.s.u2.nonInlineCharsTwoByte = base->twoByteChars(nogc) + start;
}
base->setDependedOn();
d.s.u3.base = base;
if (isTenured() && !base->isTenured()) {
base->storeBuffer()->putWholeCell(this);
}
}
MOZ_ALWAYS_INLINE JSLinearString* JSDependentString::new_(
JSContext* cx, JSLinearString* baseArg, size_t start, size_t length,
js::gc::Heap heap) {
// Do not try to make a dependent string that could fit inline.
MOZ_ASSERT_IF(baseArg->hasTwoByteChars(),
!JSInlineString::lengthFits<char16_t>(length));
MOZ_ASSERT_IF(!baseArg->hasTwoByteChars(),
!JSInlineString::lengthFits<JS::Latin1Char>(length));
/*
* Try to avoid long chains of dependent strings. We can't avoid these
* entirely, however, due to how ropes are flattened.
*/
if (baseArg->isDependent()) {
start += baseArg->asDependent().baseOffset();
baseArg = baseArg->asDependent().base();
}
MOZ_ASSERT(start + length <= baseArg->length());
JSDependentString* str =
cx->newCell<JSDependentString, js::NoGC>(heap, baseArg, start, length);
if (str) {
return str;
}
JS::Rooted<JSLinearString*> base(cx, baseArg);
return cx->newCell<JSDependentString>(heap, base, start, length);
}
inline JSLinearString::JSLinearString(const char16_t* chars, size_t length,
bool hasBuffer) {
uint32_t flags = INIT_LINEAR_FLAGS | (hasBuffer ? HAS_STRING_BUFFER_BIT : 0);
setLengthAndFlags(length, flags);
// Check that the new buffer is located in the StringBufferArena.
checkStringCharsArena(chars, hasBuffer);
d.s.u2.nonInlineCharsTwoByte = chars;
}
inline JSLinearString::JSLinearString(const JS::Latin1Char* chars,
size_t length, bool hasBuffer) {
uint32_t flags = INIT_LINEAR_FLAGS | LATIN1_CHARS_BIT |
(hasBuffer ? HAS_STRING_BUFFER_BIT : 0);
setLengthAndFlags(length, flags);
// Check that the new buffer is located in the StringBufferArena.
checkStringCharsArena(chars, hasBuffer);
d.s.u2.nonInlineCharsLatin1 = chars;
}
template <typename CharT>
inline JSLinearString::JSLinearString(
JS::MutableHandle<JSString::OwnedChars<CharT>> chars) {
// Note that it is possible that the chars may have been moved from the
// nursery to the malloc heap when allocating the Cell that this constructor
// is initializing.
MOZ_ASSERT(chars.data());
checkStringCharsArena(chars.data(), chars.hasStringBuffer());
if (isTenured()) {
chars.ensureNonNursery();
}
uint32_t flags = INIT_LINEAR_FLAGS;
if (chars.hasStringBuffer()) {
flags |= HAS_STRING_BUFFER_BIT;
}
if constexpr (std::is_same_v<CharT, char16_t>) {
setLengthAndFlags(chars.length(), flags);
d.s.u2.nonInlineCharsTwoByte = chars.data();
} else {
setLengthAndFlags(chars.length(), flags | LATIN1_CHARS_BIT);
d.s.u2.nonInlineCharsLatin1 = chars.data();
}
}
void JSLinearString::disownCharsBecauseError() {
setLengthAndFlags(0, INIT_LINEAR_FLAGS | LATIN1_CHARS_BIT);
d.s.u2.nonInlineCharsLatin1 = nullptr;
}
inline JSLinearString* JSDependentString::rootBaseDuringMinorGC() {
JSLinearString* root = this;
while (MaybeForwarded(root)->hasBase()) {
if (root->isForwarded()) {
root = js::gc::StringRelocationOverlay::fromCell(root)
->savedNurseryBaseOrRelocOverlay();
} else {
// Possibly nursery or tenured string (not an overlay).
root = root->nurseryBaseOrRelocOverlay();
}
}
return root;
}
template <js::AllowGC allowGC, typename CharT>
MOZ_ALWAYS_INLINE JSLinearString* JSLinearString::new_(
JSContext* cx, JS::MutableHandle<JSString::OwnedChars<CharT>> chars,
js::gc::Heap heap) {
if (MOZ_UNLIKELY(!validateLengthInternal<allowGC>(cx, chars.length()))) {
return nullptr;
}
return newValidLength<allowGC>(cx, chars, heap);
}
template <js::AllowGC allowGC, typename CharT>
MOZ_ALWAYS_INLINE JSLinearString* JSLinearString::newValidLength(
JSContext* cx, JS::MutableHandle<JSString::OwnedChars<CharT>> chars,
js::gc::Heap heap) {
MOZ_ASSERT(!cx->zone()->isAtomsZone());
MOZ_ASSERT(!JSInlineString::lengthFits<CharT>(chars.length()));
JSLinearString* str = cx->newCell<JSLinearString, allowGC>(heap, chars);
if (!str) {
return nullptr;
}
if (!str->isTenured()) {
// If the following registration fails, the string is partially initialized
// and must be made valid, or its finalizer may attempt to free
// uninitialized memory.
bool ok = true;
if (chars.isMalloced()) {
ok = cx->nursery().registerMallocedBuffer(chars.data(), chars.size());
} else if (chars.hasStringBuffer()) {
ok = cx->nursery().addStringBuffer(str);
}
if (!ok) {
str->disownCharsBecauseError();
if (allowGC) {
ReportOutOfMemory(cx);
}
return nullptr;
}
} else {
// Note: this will overcount if the same StringBuffer is used by multiple JS
// strings. Unfortunately we don't have a good way to avoid this.
cx->zone()->addCellMemory(str, chars.size(), js::MemoryUse::StringContents);
}
// Either the tenured Cell or the nursery's registry owns the chars now.
chars.release();
return str;
}
template <typename CharT>
MOZ_ALWAYS_INLINE JSAtom* JSAtom::newValidLength(JSContext* cx,
OwnedChars<CharT>& chars,
js::HashNumber hash) {
size_t length = chars.length();
MOZ_ASSERT(validateLength(cx, length));
MOZ_ASSERT(cx->zone()->isAtomsZone());
// Note: atom allocation can't GC. The unrooted |chars| argument relies on
// this.
JSAtom* str = cx->newCell<js::NormalAtom, js::NoGC>(chars, hash);
if (!str) {
return nullptr;
}
// The atom now owns the chars.
chars.release();
MOZ_ASSERT(str->isTenured());
cx->zone()->addCellMemory(str, length * sizeof(CharT),
js::MemoryUse::StringContents);
return str;
}
inline js::PropertyName* JSLinearString::toPropertyName(JSContext* cx) {
#ifdef DEBUG
uint32_t dummy;
MOZ_ASSERT(!isIndex(&dummy));
#endif
JSAtom* atom = js::AtomizeString(cx, this);
if (!atom) {
return nullptr;
}
return atom->asPropertyName();
}
// String characters are movable in the following cases:
//
// 1. Inline nursery strings (moved during promotion)
// 2. Nursery strings with nursery chars (moved during promotion)
// 3. Nursery strings that are deduplicated (moved during promotion)
// 4. Inline tenured strings (moved during compaction)
//
// This method does not consider #3, because if this method returns true and the
// caller does not want the characters to move, it can fix them in place by
// setting the nondeduplicatable bit. (If the bit were already taken into
// consideration, then the caller wouldn't know whether the movability is
// "fixable" or not. If it is *only* movable because of the lack of the bit
// being set, then it is fixable by setting the bit.)
bool JSLinearString::hasMovableChars() const {
const JSLinearString* topBase = this;
while (topBase->hasBase()) {
topBase = topBase->base();
}
if (topBase->isInline()) {
return true;
}
if (topBase->isTenured()) {
return false;
}
return topBase->storeBuffer()->nursery().isInside(
topBase->nonInlineCharsRaw());
}
template <js::AllowGC allowGC>
MOZ_ALWAYS_INLINE JSThinInlineString* JSThinInlineString::new_(
JSContext* cx, js::gc::Heap heap) {
MOZ_ASSERT(!cx->zone()->isAtomsZone());
return cx->newCell<JSThinInlineString, allowGC>(heap);
}
template <js::AllowGC allowGC>
MOZ_ALWAYS_INLINE JSFatInlineString* JSFatInlineString::new_(
JSContext* cx, js::gc::Heap heap) {
MOZ_ASSERT(!cx->zone()->isAtomsZone());
return cx->newCell<JSFatInlineString, allowGC>(heap);
}
inline JSThinInlineString::JSThinInlineString(size_t length,
JS::Latin1Char** chars) {
MOZ_ASSERT(lengthFits<JS::Latin1Char>(length));
setLengthAndFlags(length, INIT_THIN_INLINE_FLAGS | LATIN1_CHARS_BIT);
*chars = d.inlineStorageLatin1;
}
inline JSThinInlineString::JSThinInlineString(size_t length, char16_t** chars) {
MOZ_ASSERT(lengthFits<char16_t>(length));
setLengthAndFlags(length, INIT_THIN_INLINE_FLAGS);
*chars = d.inlineStorageTwoByte;
}
inline JSFatInlineString::JSFatInlineString(size_t length,
JS::Latin1Char** chars) {
MOZ_ASSERT(lengthFits<JS::Latin1Char>(length));
setLengthAndFlags(length, INIT_FAT_INLINE_FLAGS | LATIN1_CHARS_BIT);
*chars = d.inlineStorageLatin1;
}
inline JSFatInlineString::JSFatInlineString(size_t length, char16_t** chars) {
MOZ_ASSERT(lengthFits<char16_t>(length));
setLengthAndFlags(length, INIT_FAT_INLINE_FLAGS);
*chars = d.inlineStorageTwoByte;
}
inline JSExternalString::JSExternalString(
const char16_t* chars, size_t length,
const JSExternalStringCallbacks* callbacks) {
MOZ_ASSERT(callbacks);
setLengthAndFlags(length, EXTERNAL_FLAGS);
d.s.u2.nonInlineCharsTwoByte = chars;
d.s.u3.externalCallbacks = callbacks;
}
inline JSExternalString::JSExternalString(
const JS::Latin1Char* chars, size_t length,
const JSExternalStringCallbacks* callbacks) {
MOZ_ASSERT(callbacks);
setLengthAndFlags(length, EXTERNAL_FLAGS | LATIN1_CHARS_BIT);
d.s.u2.nonInlineCharsLatin1 = chars;
d.s.u3.externalCallbacks = callbacks;
}
template <typename CharT>
/* static */
MOZ_ALWAYS_INLINE JSExternalString* JSExternalString::newImpl(
JSContext* cx, const CharT* chars, size_t length,
const JSExternalStringCallbacks* callbacks) {
if (MOZ_UNLIKELY(!validateLength(cx, length))) {
return nullptr;
}
auto* str = cx->newCell<JSExternalString>(chars, length, callbacks);
if (!str) {
return nullptr;
}
size_t nbytes = length * sizeof(CharT);
MOZ_ASSERT(str->isTenured());
js::AddCellMemory(str, nbytes, js::MemoryUse::StringContents);
return str;
}
/* static */
MOZ_ALWAYS_INLINE JSExternalString* JSExternalString::new_(
JSContext* cx, const JS::Latin1Char* chars, size_t length,
const JSExternalStringCallbacks* callbacks) {
return newImpl(cx, chars, length, callbacks);
}
/* static */
MOZ_ALWAYS_INLINE JSExternalString* JSExternalString::new_(
JSContext* cx, const char16_t* chars, size_t length,
const JSExternalStringCallbacks* callbacks) {
return newImpl(cx, chars, length, callbacks);
}
template <typename CharT>
inline js::NormalAtom::NormalAtom(const OwnedChars<CharT>& chars,
js::HashNumber hash)
: hash_(hash) {
// Check that the new buffer is located in the StringBufferArena
checkStringCharsArena(chars.data(), chars.hasStringBuffer());
uint32_t flags = INIT_LINEAR_FLAGS | ATOM_BIT;
if (chars.hasStringBuffer()) {
flags |= HAS_STRING_BUFFER_BIT;
}
if constexpr (std::is_same_v<CharT, char16_t>) {
setLengthAndFlags(chars.length(), flags);
d.s.u2.nonInlineCharsTwoByte = chars.data();
} else {
setLengthAndFlags(chars.length(), flags | LATIN1_CHARS_BIT);
d.s.u2.nonInlineCharsLatin1 = chars.data();
}
}
#ifndef JS_64BIT
inline js::ThinInlineAtom::ThinInlineAtom(size_t length, JS::Latin1Char** chars,
js::HashNumber hash)
: NormalAtom(hash) {
setLengthAndFlags(length,
INIT_THIN_INLINE_FLAGS | LATIN1_CHARS_BIT | ATOM_BIT);
*chars = d.inlineStorageLatin1;
}
inline js::ThinInlineAtom::ThinInlineAtom(size_t length, char16_t** chars,
js::HashNumber hash)
: NormalAtom(hash) {
setLengthAndFlags(length, INIT_THIN_INLINE_FLAGS | ATOM_BIT);
*chars = d.inlineStorageTwoByte;
}
#endif
inline js::FatInlineAtom::FatInlineAtom(size_t length, JS::Latin1Char** chars,
js::HashNumber hash)
: hash_(hash) {
MOZ_ASSERT(lengthFits<JS::Latin1Char>(length));
setLengthAndFlags(length,
INIT_FAT_INLINE_FLAGS | LATIN1_CHARS_BIT | ATOM_BIT);
*chars = d.inlineStorageLatin1;
}
inline js::FatInlineAtom::FatInlineAtom(size_t length, char16_t** chars,
js::HashNumber hash)
: hash_(hash) {
MOZ_ASSERT(lengthFits<char16_t>(length));
setLengthAndFlags(length, INIT_FAT_INLINE_FLAGS | ATOM_BIT);
*chars = d.inlineStorageTwoByte;
}
inline JSLinearString* js::StaticStrings::getUnitString(JSContext* cx,
char16_t c) {
if (c < UNIT_STATIC_LIMIT) {
return getUnit(c);
}
return js::NewInlineString<CanGC>(cx, {c}, 1);
}
inline JSLinearString* js::StaticStrings::getUnitStringForElement(
JSContext* cx, JSString* str, size_t index) {
MOZ_ASSERT(index < str->length());
char16_t c;
if (!str->getChar(cx, index, &c)) {
return nullptr;
}
return getUnitString(cx, c);
}
inline JSLinearString* js::StaticStrings::getUnitStringForElement(
JSContext* cx, const JSLinearString* str, size_t index) {
MOZ_ASSERT(index < str->length());
char16_t c = str->latin1OrTwoByteChar(index);
return getUnitString(cx, c);
}
MOZ_ALWAYS_INLINE void JSString::finalize(JS::GCContext* gcx) {
/* FatInline strings are in a different arena. */
MOZ_ASSERT(getAllocKind() != js::gc::AllocKind::FAT_INLINE_STRING);
MOZ_ASSERT(getAllocKind() != js::gc::AllocKind::FAT_INLINE_ATOM);
if (isLinear()) {
asLinear().finalize(gcx);
} else {
MOZ_ASSERT(isRope());
}
}
inline void JSLinearString::finalize(JS::GCContext* gcx) {
MOZ_ASSERT(getAllocKind() != js::gc::AllocKind::FAT_INLINE_STRING);
MOZ_ASSERT(getAllocKind() != js::gc::AllocKind::FAT_INLINE_ATOM);
if (!isInline() && !isDependent()) {
size_t size = allocSize();
if (hasStringBuffer()) {
mozilla::StringBuffer* buffer = stringBuffer();
buffer->Release();
gcx->removeCellMemory(this, size, js::MemoryUse::StringContents);
} else {
gcx->free_(this, nonInlineCharsRaw(), size,
js::MemoryUse::StringContents);
}
}
}
inline void JSFatInlineString::finalize(JS::GCContext* gcx) {
MOZ_ASSERT(getAllocKind() == js::gc::AllocKind::FAT_INLINE_STRING);
MOZ_ASSERT(isInline());
// Nothing to do.
}
inline void js::FatInlineAtom::finalize(JS::GCContext* gcx) {
MOZ_ASSERT(JSString::isAtom());
MOZ_ASSERT(getAllocKind() == js::gc::AllocKind::FAT_INLINE_ATOM);
// Nothing to do.
}
inline void JSExternalString::finalize(JS::GCContext* gcx) {
MOZ_ASSERT(JSString::isExternal());
if (hasLatin1Chars()) {
size_t nbytes = length() * sizeof(JS::Latin1Char);
gcx->removeCellMemory(this, nbytes, js::MemoryUse::StringContents);
callbacks()->finalize(const_cast<JS::Latin1Char*>(rawLatin1Chars()));
} else {
size_t nbytes = length() * sizeof(char16_t);
gcx->removeCellMemory(this, nbytes, js::MemoryUse::StringContents);
callbacks()->finalize(const_cast<char16_t*>(rawTwoByteChars()));
}
}
#endif /* vm_StringType_inl_h */