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/* -*- 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 number type and wrapper class.
*/
#include "jsnum.h"
#include "mozilla/Casting.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/Maybe.h"
#include "mozilla/RangedPtr.h"
#include "mozilla/TextUtils.h"
#include "mozilla/Utf8.h"
#include <algorithm>
#include <iterator>
#include <limits>
#ifdef HAVE_LOCALECONV
# include <locale.h>
#endif
#include <math.h>
#include <string.h> // memmove
#include <string_view>
#include "jstypes.h"
#include "builtin/String.h"
#include "double-conversion/double-conversion.h"
#include "frontend/ParserAtom.h" // frontend::{ParserAtomsTable, TaggedParserAtomIndex}
#include "jit/InlinableNatives.h"
#include "js/CharacterEncoding.h"
#include "js/Conversions.h"
#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_*
#include "js/GCAPI.h"
#if !JS_HAS_INTL_API
# include "js/LocaleSensitive.h"
#endif
#include "js/PropertyAndElement.h" // JS_DefineFunctions
#include "js/PropertySpec.h"
#include "util/DoubleToString.h"
#include "util/Memory.h"
#include "util/StringBuilder.h"
#include "vm/BigIntType.h"
#include "vm/GlobalObject.h"
#include "vm/JSAtomUtils.h" // Atomize, AtomizeString
#include "vm/JSContext.h"
#include "vm/JSObject.h"
#include "vm/StaticStrings.h"
#include "vm/Compartment-inl.h" // For js::UnwrapAndTypeCheckThis
#include "vm/GeckoProfiler-inl.h"
#include "vm/JSAtomUtils-inl.h" // BackfillIndexInCharBuffer
#include "vm/NativeObject-inl.h"
#include "vm/NumberObject-inl.h"
#include "vm/StringType-inl.h"
using namespace js;
using mozilla::Abs;
using mozilla::AsciiAlphanumericToNumber;
using mozilla::IsAsciiAlphanumeric;
using mozilla::IsAsciiDigit;
using mozilla::MaxNumberValue;
using mozilla::Maybe;
using mozilla::MinNumberValue;
using mozilla::NegativeInfinity;
using mozilla::NumberEqualsInt32;
using mozilla::PositiveInfinity;
using mozilla::RangedPtr;
using mozilla::Utf8AsUnsignedChars;
using mozilla::Utf8Unit;
using JS::AutoCheckCannotGC;
using JS::GenericNaN;
using JS::ToInt16;
using JS::ToInt32;
using JS::ToInt64;
using JS::ToInt8;
using JS::ToUint16;
using JS::ToUint32;
using JS::ToUint64;
using JS::ToUint8;
static bool EnsureDtoaState(JSContext* cx) {
if (!cx->dtoaState) {
cx->dtoaState = NewDtoaState();
if (!cx->dtoaState) {
return false;
}
}
return true;
}
template <typename CharT>
static inline void AssertWellPlacedNumericSeparator(const CharT* s,
const CharT* start,
const CharT* end) {
MOZ_ASSERT(start < end, "string is non-empty");
MOZ_ASSERT(s > start, "number can't start with a separator");
MOZ_ASSERT(s + 1 < end,
"final character in a numeric literal can't be a separator");
MOZ_ASSERT(*(s + 1) != '_',
"separator can't be followed by another separator");
MOZ_ASSERT(*(s - 1) != '_',
"separator can't be preceded by another separator");
}
namespace {
template <typename CharT>
class BinaryDigitReader {
const int base; /* Base of number; must be a power of 2 */
int digit; /* Current digit value in radix given by base */
int digitMask; /* Mask to extract the next bit from digit */
const CharT* cur; /* Pointer to the remaining digits */
const CharT* start; /* Pointer to the start of the string */
const CharT* end; /* Pointer to first non-digit */
public:
BinaryDigitReader(int base, const CharT* start, const CharT* end)
: base(base),
digit(0),
digitMask(0),
cur(start),
start(start),
end(end) {}
/* Return the next binary digit from the number, or -1 if done. */
int nextDigit() {
if (digitMask == 0) {
if (cur == end) {
return -1;
}
int c = *cur++;
if (c == '_') {
AssertWellPlacedNumericSeparator(cur - 1, start, end);
c = *cur++;
}
MOZ_ASSERT(IsAsciiAlphanumeric(c));
digit = AsciiAlphanumericToNumber(c);
digitMask = base >> 1;
}
int bit = (digit & digitMask) != 0;
digitMask >>= 1;
return bit;
}
};
} /* anonymous namespace */
/*
* The fast result might also have been inaccurate for power-of-two bases. This
* happens if the addition in value * 2 + digit causes a round-down to an even
* least significant mantissa bit when the first dropped bit is a one. If any
* of the following digits in the number (which haven't been added in yet) are
* nonzero, then the correct action would have been to round up instead of
* down. An example occurs when reading the number 0x1000000000000081, which
* rounds to 0x1000000000000000 instead of 0x1000000000000100.
*/
template <typename CharT>
static double ComputeAccurateBinaryBaseInteger(const CharT* start,
const CharT* end, int base) {
BinaryDigitReader<CharT> bdr(base, start, end);
/* Skip leading zeroes. */
int bit;
do {
bit = bdr.nextDigit();
} while (bit == 0);
MOZ_ASSERT(bit == 1); // guaranteed by Get{Prefix,Decimal}Integer
/* Gather the 53 significant bits (including the leading 1). */
double value = 1.0;
for (int j = 52; j > 0; j--) {
bit = bdr.nextDigit();
if (bit < 0) {
return value;
}
value = value * 2 + bit;
}
/* bit2 is the 54th bit (the first dropped from the mantissa). */
int bit2 = bdr.nextDigit();
if (bit2 >= 0) {
double factor = 2.0;
int sticky = 0; /* sticky is 1 if any bit beyond the 54th is 1 */
int bit3;
while ((bit3 = bdr.nextDigit()) >= 0) {
sticky |= bit3;
factor *= 2;
}
value += bit2 & (bit | sticky);
value *= factor;
}
return value;
}
template <typename CharT>
double js::ParseDecimalNumber(const mozilla::Range<const CharT> chars) {
MOZ_ASSERT(chars.length() > 0);
uint64_t dec = 0;
RangedPtr<const CharT> s = chars.begin(), end = chars.end();
do {
CharT c = *s;
MOZ_ASSERT('0' <= c && c <= '9');
uint8_t digit = c - '0';
uint64_t next = dec * 10 + digit;
MOZ_ASSERT(next < DOUBLE_INTEGRAL_PRECISION_LIMIT,
"next value won't be an integrally-precise double");
dec = next;
} while (++s < end);
return static_cast<double>(dec);
}
template double js::ParseDecimalNumber(
const mozilla::Range<const Latin1Char> chars);
template double js::ParseDecimalNumber(
const mozilla::Range<const char16_t> chars);
template <typename CharT>
static bool GetPrefixIntegerImpl(const CharT* start, const CharT* end, int base,
IntegerSeparatorHandling separatorHandling,
const CharT** endp, double* dp) {
MOZ_ASSERT(start <= end);
MOZ_ASSERT(2 <= base && base <= 36);
const CharT* s = start;
double d = 0.0;
for (; s < end; s++) {
CharT c = *s;
if (!IsAsciiAlphanumeric(c)) {
if (c == '_' &&
separatorHandling == IntegerSeparatorHandling::SkipUnderscore) {
AssertWellPlacedNumericSeparator(s, start, end);
continue;
}
break;
}
uint8_t digit = AsciiAlphanumericToNumber(c);
if (digit >= base) {
break;
}
d = d * base + digit;
}
*endp = s;
*dp = d;
/* If we haven't reached the limit of integer precision, we're done. */
if (d < DOUBLE_INTEGRAL_PRECISION_LIMIT) {
return true;
}
/*
* Otherwise compute the correct integer from the prefix of valid digits
* if we're computing for base ten or a power of two. Don't worry about
* other bases; see ES2018, 18.2.5 `parseInt(string, radix)`, step 13.
*/
if (base == 10) {
return false;
}
if ((base & (base - 1)) == 0) {
*dp = ComputeAccurateBinaryBaseInteger(start, s, base);
}
return true;
}
template <typename CharT>
bool js::GetPrefixInteger(const CharT* start, const CharT* end, int base,
IntegerSeparatorHandling separatorHandling,
const CharT** endp, double* dp) {
if (GetPrefixIntegerImpl(start, end, base, separatorHandling, endp, dp)) {
return true;
}
// Can only fail for base 10.
MOZ_ASSERT(base == 10);
// If we're accumulating a decimal number and the number is >= 2^53, then the
// fast result from the loop in GetPrefixIntegerImpl may be inaccurate. Call
// GetDecimal to get the correct answer.
return GetDecimal(start, *endp, dp);
}
namespace js {
template bool GetPrefixInteger(const char16_t* start, const char16_t* end,
int base,
IntegerSeparatorHandling separatorHandling,
const char16_t** endp, double* dp);
template bool GetPrefixInteger(const Latin1Char* start, const Latin1Char* end,
int base,
IntegerSeparatorHandling separatorHandling,
const Latin1Char** endp, double* dp);
} // namespace js
template <typename CharT>
bool js::GetDecimalInteger(const CharT* start, const CharT* end, double* dp) {
MOZ_ASSERT(start <= end);
double d = 0.0;
for (const CharT* s = start; s < end; s++) {
CharT c = *s;
if (c == '_') {
AssertWellPlacedNumericSeparator(s, start, end);
continue;
}
MOZ_ASSERT(IsAsciiDigit(c));
int digit = c - '0';
d = d * 10 + digit;
}
// If we haven't reached the limit of integer precision, we're done.
if (d < DOUBLE_INTEGRAL_PRECISION_LIMIT) {
*dp = d;
return true;
}
// Otherwise compute the correct integer using GetDecimal.
return GetDecimal(start, end, dp);
}
namespace js {
template bool GetDecimalInteger(const char16_t* start, const char16_t* end,
double* dp);
template bool GetDecimalInteger(const Latin1Char* start, const Latin1Char* end,
double* dp);
template <>
bool GetDecimalInteger<Utf8Unit>(const Utf8Unit* start, const Utf8Unit* end,
double* dp) {
return GetDecimalInteger(Utf8AsUnsignedChars(start), Utf8AsUnsignedChars(end),
dp);
}
} // namespace js
template <typename CharT>
bool js::GetDecimal(const CharT* start, const CharT* end, double* dp) {
MOZ_ASSERT(start <= end);
size_t length = end - start;
auto convert = [](auto* chars, size_t length) -> double {
using SToDConverter = double_conversion::StringToDoubleConverter;
SToDConverter converter(/* flags = */ 0, /* empty_string_value = */ 0.0,
/* junk_string_value = */ 0.0,
/* infinity_symbol = */ nullptr,
/* nan_symbol = */ nullptr);
int lengthInt = mozilla::AssertedCast<int>(length);
int processed = 0;
double d = converter.StringToDouble(chars, lengthInt, &processed);
MOZ_ASSERT(processed >= 0);
MOZ_ASSERT(size_t(processed) == length);
return d;
};
// If there are no underscores, we don't need to copy the chars.
bool hasUnderscore = std::any_of(start, end, [](auto c) { return c == '_'; });
if (!hasUnderscore) {
if constexpr (std::is_same_v<CharT, char16_t>) {
*dp = convert(reinterpret_cast<const uc16*>(start), length);
} else {
static_assert(std::is_same_v<CharT, Latin1Char>);
*dp = convert(reinterpret_cast<const char*>(start), length);
}
return true;
}
Vector<char, 32, SystemAllocPolicy> chars;
if (!chars.growByUninitialized(length)) {
return false;
}
const CharT* s = start;
size_t i = 0;
for (; s < end; s++) {
CharT c = *s;
if (c == '_') {
AssertWellPlacedNumericSeparator(s, start, end);
continue;
}
MOZ_ASSERT(IsAsciiDigit(c) || c == '.' || c == 'e' || c == 'E' ||
c == '+' || c == '-');
chars[i++] = char(c);
}
*dp = convert(chars.begin(), i);
return true;
}
namespace js {
template bool GetDecimal(const char16_t* start, const char16_t* end,
double* dp);
template bool GetDecimal(const Latin1Char* start, const Latin1Char* end,
double* dp);
template <>
bool GetDecimal<Utf8Unit>(const Utf8Unit* start, const Utf8Unit* end,
double* dp) {
return GetDecimal(Utf8AsUnsignedChars(start), Utf8AsUnsignedChars(end), dp);
}
} // namespace js
static bool num_parseFloat(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
if (args[0].isNumber()) {
// ToString(-0) is "0", handle it accordingly.
if (args[0].isDouble() && args[0].toDouble() == 0.0) {
args.rval().setInt32(0);
} else {
args.rval().set(args[0]);
}
return true;
}
JSString* str = ToString<CanGC>(cx, args[0]);
if (!str) {
return false;
}
if (str->hasIndexValue()) {
args.rval().setNumber(str->getIndexValue());
return true;
}
JSLinearString* linear = str->ensureLinear(cx);
if (!linear) {
return false;
}
double d;
AutoCheckCannotGC nogc;
if (linear->hasLatin1Chars()) {
const Latin1Char* begin = linear->latin1Chars(nogc);
const Latin1Char* end;
d = js_strtod(begin, begin + linear->length(), &end);
if (end == begin) {
d = GenericNaN();
}
} else {
const char16_t* begin = linear->twoByteChars(nogc);
const char16_t* end;
d = js_strtod(begin, begin + linear->length(), &end);
if (end == begin) {
d = GenericNaN();
}
}
args.rval().setDouble(d);
return true;
}
// ES2023 draft rev 053d34c87b14d9234d6f7f45bd61074b72ca9d69
// 19.2.5 parseInt ( string, radix )
template <typename CharT>
static bool ParseIntImpl(JSContext* cx, const CharT* chars, size_t length,
bool stripPrefix, int32_t radix, double* res) {
// Step 2.
const CharT* end = chars + length;
const CharT* s = SkipSpace(chars, end);
MOZ_ASSERT(chars <= s);
MOZ_ASSERT(s <= end);
// Steps 3-4.
bool negative = (s != end && s[0] == '-');
// Step 5. */
if (s != end && (s[0] == '-' || s[0] == '+')) {
s++;
}
// Step 10.
if (stripPrefix) {
if (end - s >= 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) {
s += 2;
radix = 16;
}
}
// Steps 11-15.
const CharT* actualEnd;
double d;
if (!js::GetPrefixInteger(s, end, radix, IntegerSeparatorHandling::None,
&actualEnd, &d)) {
ReportOutOfMemory(cx);
return false;
}
if (s == actualEnd) {
*res = GenericNaN();
} else {
*res = negative ? -d : d;
}
return true;
}
// ES2023 draft rev 053d34c87b14d9234d6f7f45bd61074b72ca9d69
// 19.2.5 parseInt ( string, radix )
bool js::NumberParseInt(JSContext* cx, HandleString str, int32_t radix,
MutableHandleValue result) {
// Step 7.
bool stripPrefix = true;
// Steps 8-9.
if (radix != 0) {
if (radix < 2 || radix > 36) {
result.setNaN();
return true;
}
if (radix != 16) {
stripPrefix = false;
}
} else {
radix = 10;
}
MOZ_ASSERT(2 <= radix && radix <= 36);
JSLinearString* linear = str->ensureLinear(cx);
if (!linear) {
return false;
}
// Steps 2-5, 10-16.
AutoCheckCannotGC nogc;
size_t length = linear->length();
double number;
if (linear->hasLatin1Chars()) {
if (!ParseIntImpl(cx, linear->latin1Chars(nogc), length, stripPrefix, radix,
&number)) {
return false;
}
} else {
if (!ParseIntImpl(cx, linear->twoByteChars(nogc), length, stripPrefix,
radix, &number)) {
return false;
}
}
result.setNumber(number);
return true;
}
// ES2023 draft rev 053d34c87b14d9234d6f7f45bd61074b72ca9d69
// 19.2.5 parseInt ( string, radix )
static bool num_parseInt(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
/* Fast paths and exceptional cases. */
if (args.length() == 0) {
args.rval().setNaN();
return true;
}
if (args.length() == 1 || (args[1].isInt32() && (args[1].toInt32() == 0 ||
args[1].toInt32() == 10))) {
if (args[0].isInt32()) {
args.rval().set(args[0]);
return true;
}
/*
* Step 1 is |inputString = ToString(string)|. When string >=
* 1e21, ToString(string) is in the form "NeM". 'e' marks the end of
* the word, which would mean the result of parseInt(string) should be |N|.
*
* To preserve this behaviour, we can't use the fast-path when string >=
* 1e21, or else the result would be |NeM|.
*
* The same goes for values smaller than 1.0e-6, because the string would be
* in the form of "Ne-M".
*/
if (args[0].isDouble()) {
double d = args[0].toDouble();
if (DOUBLE_DECIMAL_IN_SHORTEST_LOW <= d &&
d < DOUBLE_DECIMAL_IN_SHORTEST_HIGH) {
args.rval().setNumber(floor(d));
return true;
}
if (-DOUBLE_DECIMAL_IN_SHORTEST_HIGH < d &&
d <= -DOUBLE_DECIMAL_IN_SHORTEST_LOW) {
args.rval().setNumber(-floor(-d));
return true;
}
if (d == 0.0) {
args.rval().setInt32(0);
return true;
}
}
if (args[0].isString()) {
JSString* str = args[0].toString();
if (str->hasIndexValue()) {
args.rval().setNumber(str->getIndexValue());
return true;
}
}
}
// Step 1.
RootedString inputString(cx, ToString<CanGC>(cx, args[0]));
if (!inputString) {
return false;
}
// Step 6.
int32_t radix = 0;
if (args.hasDefined(1)) {
if (!ToInt32(cx, args[1], &radix)) {
return false;
}
}
// Steps 2-5, 7-16.
return NumberParseInt(cx, inputString, radix, args.rval());
}
static constexpr JSFunctionSpec number_functions[] = {
JS_SELF_HOSTED_FN("isNaN", "Global_isNaN", 1, JSPROP_RESOLVING),
JS_SELF_HOSTED_FN("isFinite", "Global_isFinite", 1, JSPROP_RESOLVING),
JS_FS_END,
};
const JSClass NumberObject::class_ = {
"Number",
JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_HAS_CACHED_PROTO(JSProto_Number),
JS_NULL_CLASS_OPS,
&NumberObject::classSpec_,
};
static bool Number(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() > 0) {
// BigInt proposal section 6.2, steps 2a-c.
if (!ToNumeric(cx, args[0])) {
return false;
}
if (args[0].isBigInt()) {
args[0].setNumber(BigInt::numberValue(args[0].toBigInt()));
}
MOZ_ASSERT(args[0].isNumber());
}
if (!args.isConstructing()) {
if (args.length() > 0) {
args.rval().set(args[0]);
} else {
args.rval().setInt32(0);
}
return true;
}
RootedObject proto(cx);
if (!GetPrototypeFromBuiltinConstructor(cx, args, JSProto_Number, &proto)) {
return false;
}
double d = args.length() > 0 ? args[0].toNumber() : 0;
JSObject* obj = NumberObject::create(cx, d, proto);
if (!obj) {
return false;
}
args.rval().setObject(*obj);
return true;
}
// ES2020 draft rev e08b018785606bc6465a0456a79604b149007932
// 20.1.3 Properties of the Number Prototype Object, thisNumberValue.
MOZ_ALWAYS_INLINE
static bool ThisNumberValue(JSContext* cx, const CallArgs& args,
const char* methodName, double* number) {
HandleValue thisv = args.thisv();
// Step 1.
if (thisv.isNumber()) {
*number = thisv.toNumber();
return true;
}
// Steps 2-3.
auto* obj = UnwrapAndTypeCheckThis<NumberObject>(cx, args, methodName);
if (!obj) {
return false;
}
*number = obj->unbox();
return true;
}
// On-off helper function for the self-hosted Number_toLocaleString method.
// This only exists to produce an error message with the right method name.
bool js::ThisNumberValueForToLocaleString(JSContext* cx, unsigned argc,
Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
double d;
if (!ThisNumberValue(cx, args, "toLocaleString", &d)) {
return false;
}
args.rval().setNumber(d);
return true;
}
static bool num_toSource(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
double d;
if (!ThisNumberValue(cx, args, "toSource", &d)) {
return false;
}
JSStringBuilder sb(cx);
if (!sb.append("(new Number(") ||
!NumberValueToStringBuilder(NumberValue(d), sb) || !sb.append("))")) {
return false;
}
JSString* str = sb.finishString();
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
// Subtract one from DTOSTR_STANDARD_BUFFER_SIZE to exclude the null-character.
static_assert(
double_conversion::DoubleToStringConverter::kMaxCharsEcmaScriptShortest ==
DTOSTR_STANDARD_BUFFER_SIZE - 1,
"double_conversion and dtoa both agree how large the longest string "
"can be");
static_assert(DTOSTR_STANDARD_BUFFER_SIZE <= JS::MaximumNumberToStringLength,
"MaximumNumberToStringLength is large enough to hold the longest "
"string produced by a conversion");
MOZ_ALWAYS_INLINE
static JSLinearString* LookupDtoaCache(JSContext* cx, double d) {
if (Realm* realm = cx->realm()) {
if (JSLinearString* str = realm->dtoaCache.lookup(10, d)) {
return str;
}
}
return nullptr;
}
MOZ_ALWAYS_INLINE
static void CacheNumber(JSContext* cx, double d, JSLinearString* str) {
if (Realm* realm = cx->realm()) {
realm->dtoaCache.cache(10, d, str);
}
}
MOZ_ALWAYS_INLINE
static JSLinearString* LookupInt32ToString(JSContext* cx, int32_t si) {
if (si >= 0 && StaticStrings::hasInt(si)) {
return cx->staticStrings().getInt(si);
}
return LookupDtoaCache(cx, si);
}
template <typename T>
MOZ_ALWAYS_INLINE static T* BackfillInt32InBuffer(int32_t si, T* buffer,
size_t size, size_t* length) {
uint32_t ui = Abs(si);
MOZ_ASSERT_IF(si == INT32_MIN, ui == uint32_t(INT32_MAX) + 1);
RangedPtr<T> end(buffer + size - 1, buffer, size);
*end = '\0';
RangedPtr<T> start = BackfillIndexInCharBuffer(ui, end);
if (si < 0) {
*--start = '-';
}
*length = end - start;
return start.get();
}
template <AllowGC allowGC>
JSLinearString* js::Int32ToString(JSContext* cx, int32_t si) {
return js::Int32ToStringWithHeap<allowGC>(cx, si, gc::Heap::Default);
}
template JSLinearString* js::Int32ToString<CanGC>(JSContext* cx, int32_t si);
template JSLinearString* js::Int32ToString<NoGC>(JSContext* cx, int32_t si);
template <AllowGC allowGC>
JSLinearString* js::Int32ToStringWithHeap(JSContext* cx, int32_t si,
gc::Heap heap) {
if (JSLinearString* str = LookupInt32ToString(cx, si)) {
return str;
}
Latin1Char buffer[JSFatInlineString::MAX_LENGTH_LATIN1 + 1];
size_t length;
Latin1Char* start =
BackfillInt32InBuffer(si, buffer, std::size(buffer), &length);
mozilla::Range<const Latin1Char> chars(start, length);
JSInlineString* str = NewInlineString<allowGC>(cx, chars, heap);
if (!str) {
return nullptr;
}
if (si >= 0) {
str->maybeInitializeIndexValue(si);
}
CacheNumber(cx, si, str);
return str;
}
template JSLinearString* js::Int32ToStringWithHeap<CanGC>(JSContext* cx,
int32_t si,
gc::Heap heap);
template JSLinearString* js::Int32ToStringWithHeap<NoGC>(JSContext* cx,
int32_t si,
gc::Heap heap);
JSLinearString* js::Int32ToStringPure(JSContext* cx, int32_t si) {
AutoUnsafeCallWithABI unsafe;
return Int32ToString<NoGC>(cx, si);
}
JSAtom* js::Int32ToAtom(JSContext* cx, int32_t si) {
if (JSLinearString* str = LookupInt32ToString(cx, si)) {
return js::AtomizeString(cx, str);
}
char buffer[JSFatInlineString::MAX_LENGTH_TWO_BYTE + 1];
size_t length;
char* start = BackfillInt32InBuffer(
si, buffer, JSFatInlineString::MAX_LENGTH_TWO_BYTE + 1, &length);
Maybe<uint32_t> indexValue;
if (si >= 0) {
indexValue.emplace(si);
}
JSAtom* atom = Atomize(cx, start, length, indexValue);
if (!atom) {
return nullptr;
}
CacheNumber(cx, si, atom);
return atom;
}
frontend::TaggedParserAtomIndex js::Int32ToParserAtom(
FrontendContext* fc, frontend::ParserAtomsTable& parserAtoms, int32_t si) {
char buffer[JSFatInlineString::MAX_LENGTH_TWO_BYTE + 1];
size_t length;
char* start = BackfillInt32InBuffer(
si, buffer, JSFatInlineString::MAX_LENGTH_TWO_BYTE + 1, &length);
Maybe<uint32_t> indexValue;
if (si >= 0) {
indexValue.emplace(si);
}
return parserAtoms.internAscii(fc, start, length);
}
/* Returns a non-nullptr pointer to inside `buf`. */
template <typename T>
static char* Int32ToCStringWithBase(mozilla::Range<char> buf, T i, size_t* len,
int base) {
uint32_t u;
if constexpr (std::is_signed_v<T>) {
u = Abs(i);
} else {
u = i;
}
RangedPtr<char> cp = buf.end() - 1;
char* end = cp.get();
*cp = '\0';
/* Build the string from behind. */
switch (base) {
case 10:
cp = BackfillIndexInCharBuffer(u, cp);
break;
case 16:
do {
unsigned newu = u / 16;
*--cp = "0123456789abcdef"[u - newu * 16];
u = newu;
} while (u != 0);
break;
default:
MOZ_ASSERT(base >= 2 && base <= 36);
do {
unsigned newu = u / base;
*--cp = "0123456789abcdefghijklmnopqrstuvwxyz"[u - newu * base];
u = newu;
} while (u != 0);
break;
}
if constexpr (std::is_signed_v<T>) {
if (i < 0) {
*--cp = '-';
}
}
*len = end - cp.get();
return cp.get();
}
/* Returns a non-nullptr pointer to inside `out`. */
template <typename T, size_t Length>
static char* Int32ToCStringWithBase(char (&out)[Length], T i, size_t* len,
int base) {
// The buffer needs to be large enough to hold the largest number, including
// the sign and the terminating null-character.
static_assert(std::numeric_limits<T>::digits + (2 * std::is_signed_v<T>) <
Length);
mozilla::Range<char> buf(out, Length);
return Int32ToCStringWithBase(buf, i, len, base);
}
/* Returns a non-nullptr pointer to inside `out`. */
template <typename T, size_t Base, size_t Length>
static char* Int32ToCString(char (&out)[Length], T i, size_t* len) {
// The buffer needs to be large enough to hold the largest number, including
// the sign and the terminating null-character.
if constexpr (Base == 10) {
static_assert(std::numeric_limits<T>::digits10 + 1 + std::is_signed_v<T> <
Length);
} else {
// Compute digits16 analog to std::numeric_limits::digits10, which is
// defined as |std::numeric_limits::digits * std::log10(2)| for integer
// types.
// Note: log16(2) is 1/4.
static_assert(Base == 16);
static_assert(((std::numeric_limits<T>::digits + std::is_signed_v<T>) / 4 +
std::is_signed_v<T>) < Length);
}
mozilla::Range<char> buf(out, Length);
return Int32ToCStringWithBase(buf, i, len, Base);
}
/* Returns a non-nullptr pointer to inside `cbuf`. */
template <typename T, size_t Base = 10>
static char* Int32ToCString(ToCStringBuf* cbuf, T i, size_t* len) {
return Int32ToCString<T, Base>(cbuf->sbuf, i, len);
}
/* Returns a non-nullptr pointer to inside `cbuf`. */
template <typename T, size_t Base = 10>
static char* Int32ToCString(Int32ToCStringBuf* cbuf, T i, size_t* len) {
return Int32ToCString<T, Base>(cbuf->sbuf, i, len);
}
template <AllowGC allowGC>
static JSString* NumberToStringWithBase(JSContext* cx, double d, int base);
static bool num_toString(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
double d;
if (!ThisNumberValue(cx, args, "toString", &d)) {
return false;
}
int32_t base = 10;
if (args.hasDefined(0)) {
double d2;
if (!ToInteger(cx, args[0], &d2)) {
return false;
}
if (d2 < 2 || d2 > 36) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_RADIX);
return false;
}
base = int32_t(d2);
}
JSString* str = NumberToStringWithBase<CanGC>(cx, d, base);
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
#if !JS_HAS_INTL_API
static bool num_toLocaleString(JSContext* cx, unsigned argc, Value* vp) {
AutoJSMethodProfilerEntry pseudoFrame(cx, "Number.prototype",
"toLocaleString");
CallArgs args = CallArgsFromVp(argc, vp);
double d;
if (!ThisNumberValue(cx, args, "toLocaleString", &d)) {
return false;
}
RootedString str(cx, NumberToStringWithBase<CanGC>(cx, d, 10));
if (!str) {
return false;
}
/*
* Create the string, move back to bytes to make string twiddling
* a bit easier and so we can insert platform charset seperators.
*/
UniqueChars numBytes = EncodeAscii(cx, str);
if (!numBytes) {
return false;
}
const char* num = numBytes.get();
if (!num) {
return false;
}
/*
* Find the first non-integer value, whether it be a letter as in
* 'Infinity', a decimal point, or an 'e' from exponential notation.
*/
const char* nint = num;
if (*nint == '-') {
nint++;
}
while (*nint >= '0' && *nint <= '9') {
nint++;
}
int digits = nint - num;
const char* end = num + digits;
if (!digits) {
args.rval().setString(str);
return true;
}
JSRuntime* rt = cx->runtime();
size_t thousandsLength = strlen(rt->thousandsSeparator);
size_t decimalLength = strlen(rt->decimalSeparator);
/* Figure out how long resulting string will be. */
int buflen = strlen(num);
if (*nint == '.') {
buflen += decimalLength - 1; /* -1 to account for existing '.' */
}
const char* numGrouping;
const char* tmpGroup;
numGrouping = tmpGroup = rt->numGrouping;
int remainder = digits;
if (*num == '-') {
remainder--;
}
while (*tmpGroup != CHAR_MAX && *tmpGroup != '\0') {
if (*tmpGroup >= remainder) {
break;
}
buflen += thousandsLength;
remainder -= *tmpGroup;
tmpGroup++;
}
int nrepeat;
if (*tmpGroup == '\0' && *numGrouping != '\0') {
nrepeat = (remainder - 1) / tmpGroup[-1];
buflen += thousandsLength * nrepeat;
remainder -= nrepeat * tmpGroup[-1];
} else {
nrepeat = 0;
}
tmpGroup--;
char* buf = cx->pod_malloc<char>(buflen + 1);
if (!buf) {
return false;
}
char* tmpDest = buf;
const char* tmpSrc = num;
while (*tmpSrc == '-' || remainder--) {
MOZ_ASSERT(tmpDest - buf < buflen);
*tmpDest++ = *tmpSrc++;
}
while (tmpSrc < end) {
MOZ_ASSERT(tmpDest - buf + ptrdiff_t(thousandsLength) <= buflen);
strcpy(tmpDest, rt->thousandsSeparator);
tmpDest += thousandsLength;
MOZ_ASSERT(tmpDest - buf + *tmpGroup <= buflen);
js_memcpy(tmpDest, tmpSrc, *tmpGroup);
tmpDest += *tmpGroup;
tmpSrc += *tmpGroup;
if (--nrepeat < 0) {
tmpGroup--;
}
}
if (*nint == '.') {
MOZ_ASSERT(tmpDest - buf + ptrdiff_t(decimalLength) <= buflen);
strcpy(tmpDest, rt->decimalSeparator);
tmpDest += decimalLength;
MOZ_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint + 1)) <= buflen);
strcpy(tmpDest, nint + 1);
} else {
MOZ_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint)) <= buflen);
strcpy(tmpDest, nint);
}
if (cx->runtime()->localeCallbacks &&
cx->runtime()->localeCallbacks->localeToUnicode) {
Rooted<Value> v(cx, StringValue(str));
bool ok = !!cx->runtime()->localeCallbacks->localeToUnicode(cx, buf, &v);
if (ok) {
args.rval().set(v);
}
js_free(buf);
return ok;
}
str = NewStringCopyN<CanGC>(cx, buf, buflen);
js_free(buf);
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
#endif /* !JS_HAS_INTL_API */
bool js::num_valueOf(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
double d;
if (!ThisNumberValue(cx, args, "valueOf", &d)) {
return false;
}
args.rval().setNumber(d);
return true;
}
static const unsigned MAX_PRECISION = 100;
static bool ComputePrecisionInRange(JSContext* cx, int minPrecision,
int maxPrecision, double prec,
int* precision) {
if (minPrecision <= prec && prec <= maxPrecision) {
*precision = int(prec);
return true;
}
ToCStringBuf cbuf;
char* numStr = NumberToCString(&cbuf, prec);
MOZ_ASSERT(numStr);
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_PRECISION_RANGE,
numStr);
return false;
}
static constexpr size_t DoubleToStrResultBufSize = 128;
template <typename Op>
[[nodiscard]] static bool DoubleToStrResult(JSContext* cx, const CallArgs& args,
Op op) {
char buf[DoubleToStrResultBufSize];
const auto& converter =
double_conversion::DoubleToStringConverter::EcmaScriptConverter();
double_conversion::StringBuilder builder(buf, sizeof(buf));
bool ok = op(converter, builder);
MOZ_RELEASE_ASSERT(ok);
size_t numStrLen = builder.position();
const char* numStr = builder.Finalize();
MOZ_ASSERT(numStr == buf);
MOZ_ASSERT(numStrLen == strlen(numStr));
JSString* str = NewStringCopyN<CanGC>(cx, numStr, numStrLen);
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
// ES 2021 draft 21.1.3.3.
static bool num_toFixed(JSContext* cx, unsigned argc, Value* vp) {
AutoJSMethodProfilerEntry pseudoFrame(cx, "Number.prototype", "toFixed");
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
double d;
if (!ThisNumberValue(cx, args, "toFixed", &d)) {
return false;
}
// Steps 2-5.
int precision;
if (args.length() == 0) {
precision = 0;
} else {
double prec = 0;
if (!ToInteger(cx, args[0], &prec)) {
return false;
}
if (!ComputePrecisionInRange(cx, 0, MAX_PRECISION, prec, &precision)) {
return false;
}
}
// Step 6.
if (std::isnan(d)) {
args.rval().setString(cx->names().NaN);
return true;
}
if (std::isinf(d)) {
if (d > 0) {
args.rval().setString(cx->names().Infinity);
return true;
}
args.rval().setString(cx->names().NegativeInfinity_);
return true;
}
// Steps 7-10 for very large numbers.
if (d <= -1e21 || d >= 1e+21) {
JSString* s = NumberToString<CanGC>(cx, d);
if (!s) {
return false;
}
args.rval().setString(s);
return true;
}
// Steps 7-12.
// DoubleToStringConverter::ToFixed is documented as requiring a buffer size
// of:
//
// 1 + kMaxFixedDigitsBeforePoint + 1 + kMaxFixedDigitsAfterPoint + 1
// (one additional character for the sign, one for the decimal point,
// and one for the null terminator)
//
// We already ensured there are at most 21 digits before the point, and
// MAX_PRECISION digits after the point.
static_assert(1 + 21 + 1 + MAX_PRECISION + 1 <= DoubleToStrResultBufSize);
// The double-conversion library by default has a kMaxFixedDigitsAfterPoint of
// 60. Assert our modified version supports at least MAX_PRECISION (100).
using DToSConverter = double_conversion::DoubleToStringConverter;
static_assert(DToSConverter::kMaxFixedDigitsAfterPoint >= MAX_PRECISION);
return DoubleToStrResult(cx, args, [&](auto& converter, auto& builder) {
return converter.ToFixed(d, precision, &builder);
});
}
// ES 2021 draft 21.1.3.2.
static bool num_toExponential(JSContext* cx, unsigned argc, Value* vp) {
AutoJSMethodProfilerEntry pseudoFrame(cx, "Number.prototype",
"toExponential");
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
double d;
if (!ThisNumberValue(cx, args, "toExponential", &d)) {
return false;
}
// Step 2.
double prec = 0;
if (args.hasDefined(0)) {
if (!ToInteger(cx, args[0], &prec)) {
return false;
}
}
// Step 3.
MOZ_ASSERT_IF(!args.hasDefined(0), prec == 0);
// Step 4.
if (std::isnan(d)) {
args.rval().setString(cx->names().NaN);
return true;
}
if (std::isinf(d)) {
if (d > 0) {
args.rval().setString(cx->names().Infinity);
return true;
}
args.rval().setString(cx->names().NegativeInfinity_);
return true;
}
// Step 5.
int precision = 0;
if (!ComputePrecisionInRange(cx, 0, MAX_PRECISION, prec, &precision)) {
return false;
}
// Steps 6-15.
// DoubleToStringConverter::ToExponential is documented as adding at most 8
// characters on top of the requested digits: "the sign, the digit before the
// decimal point, the decimal point, the exponent character, the exponent's
// sign, and at most 3 exponent digits". In addition, the buffer must be able
// to hold the trailing '\0' character.
static_assert(MAX_PRECISION + 8 + 1 <= DoubleToStrResultBufSize);
return DoubleToStrResult(cx, args, [&](auto& converter, auto& builder) {
int requestedDigits = args.hasDefined(0) ? precision : -1;
return converter.ToExponential(d, requestedDigits, &builder);
});
}
// ES 2021 draft 21.1.3.5.
static bool num_toPrecision(JSContext* cx, unsigned argc, Value* vp) {
AutoJSMethodProfilerEntry pseudoFrame(cx, "Number.prototype", "toPrecision");
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
double d;
if (!ThisNumberValue(cx, args, "toPrecision", &d)) {
return false;
}
// Step 2.
if (!args.hasDefined(0)) {
JSString* str = NumberToStringWithBase<CanGC>(cx, d, 10);
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
// Step 3.
double prec = 0;
if (!ToInteger(cx, args[0], &prec)) {
return false;
}
// Step 4.
if (std::isnan(d)) {
args.rval().setString(cx->names().NaN);
return true;
}
if (std::isinf(d)) {
if (d > 0) {
args.rval().setString(cx->names().Infinity);
return true;
}
args.rval().setString(cx->names().NegativeInfinity_);
return true;
}
// Step 5.
int precision = 0;
if (!ComputePrecisionInRange(cx, 1, MAX_PRECISION, prec, &precision)) {
return false;
}
// Steps 6-14.
// DoubleToStringConverter::ToPrecision is documented as adding at most 7
// characters on top of the requested digits: "the sign, the decimal point,
// the exponent character, the exponent's sign, and at most 3 exponent
// digits". In addition, the buffer must be able to hold the trailing '\0'
// character.
static_assert(MAX_PRECISION + 7 + 1 <= DoubleToStrResultBufSize);
return DoubleToStrResult(cx, args, [&](auto& converter, auto& builder) {
return converter.ToPrecision(d, precision, &builder);
});
}
static constexpr JSFunctionSpec number_methods[] = {
JS_FN("toSource", num_toSource, 0, 0),
JS_INLINABLE_FN("toString", num_toString, 1, 0, NumberToString),
#if JS_HAS_INTL_API
JS_SELF_HOSTED_FN("toLocaleString", "Number_toLocaleString", 0, 0),
#else
JS_FN("toLocaleString", num_toLocaleString, 0, 0),
#endif
JS_FN("valueOf", num_valueOf, 0, 0),
JS_FN("toFixed", num_toFixed, 1, 0),
JS_FN("toExponential", num_toExponential, 1, 0),
JS_FN("toPrecision", num_toPrecision, 1, 0),
JS_FS_END,
};
bool js::IsInteger(double d) {
return std::isfinite(d) && JS::ToInteger(d) == d;
}
static constexpr JSFunctionSpec number_static_methods[] = {
JS_SELF_HOSTED_FN("isFinite", "Number_isFinite", 1, 0),
JS_SELF_HOSTED_FN("isInteger", "Number_isInteger", 1, 0),
JS_SELF_HOSTED_FN("isNaN", "Number_isNaN", 1, 0),
JS_SELF_HOSTED_FN("isSafeInteger", "Number_isSafeInteger", 1, 0),
JS_FS_END,
};
static constexpr JSPropertySpec number_static_properties[] = {
JS_DOUBLE_PS("POSITIVE_INFINITY", mozilla::PositiveInfinity<double>(),
JSPROP_READONLY | JSPROP_PERMANENT),
JS_DOUBLE_PS("NEGATIVE_INFINITY", mozilla::NegativeInfinity<double>(),
JSPROP_READONLY | JSPROP_PERMANENT),
JS_DOUBLE_PS("MAX_VALUE", MaxNumberValue<double>(),
JSPROP_READONLY | JSPROP_PERMANENT),
JS_DOUBLE_PS("MIN_VALUE", MinNumberValue<double>(),
JSPROP_READONLY | JSPROP_PERMANENT),
/* ES6 (April 2014 draft) 20.1.2.6 */
JS_DOUBLE_PS("MAX_SAFE_INTEGER", 9007199254740991,
JSPROP_READONLY | JSPROP_PERMANENT),
/* ES6 (April 2014 draft) 20.1.2.10 */
JS_DOUBLE_PS("MIN_SAFE_INTEGER", -9007199254740991,
JSPROP_READONLY | JSPROP_PERMANENT),
/* ES6 (May 2013 draft) 15.7.3.7 */
JS_DOUBLE_PS("EPSILON", 2.2204460492503130808472633361816e-16,
JSPROP_READONLY | JSPROP_PERMANENT),
JS_PS_END,
};
bool js::InitRuntimeNumberState(JSRuntime* rt) {
// XXX If JS_HAS_INTL_API becomes true all the time at some point,
// js::InitRuntimeNumberState is no longer fallible, and we should
// change its return type.
#if !JS_HAS_INTL_API
/* Copy locale-specific separators into the runtime strings. */
const char* thousandsSeparator;
const char* decimalPoint;
const char* grouping;
# ifdef HAVE_LOCALECONV
struct lconv* locale = localeconv();
thousandsSeparator = locale->thousands_sep;
decimalPoint = locale->decimal_point;
grouping = locale->grouping;
# else
thousandsSeparator = getenv("LOCALE_THOUSANDS_SEP");
decimalPoint = getenv("LOCALE_DECIMAL_POINT");
grouping = getenv("LOCALE_GROUPING");
# endif
if (!thousandsSeparator) {
thousandsSeparator = "'";
}
if (!decimalPoint) {
decimalPoint = ".";
}
if (!grouping) {
grouping = "\3\0";
}
/*
* We use single malloc to get the memory for all separator and grouping
* strings.
*/
size_t thousandsSeparatorSize = strlen(thousandsSeparator) + 1;
size_t decimalPointSize = strlen(decimalPoint) + 1;
size_t groupingSize = strlen(grouping) + 1;
char* storage = js_pod_malloc<char>(thousandsSeparatorSize +
decimalPointSize + groupingSize);
if (!storage) {
return false;
}
js_memcpy(storage, thousandsSeparator, thousandsSeparatorSize);
rt->thousandsSeparator = storage;
storage += thousandsSeparatorSize;
js_memcpy(storage, decimalPoint, decimalPointSize);
rt->decimalSeparator = storage;
storage += decimalPointSize;
js_memcpy(storage, grouping, groupingSize);
rt->numGrouping = grouping;
#endif /* !JS_HAS_INTL_API */
return true;
}
void js::FinishRuntimeNumberState(JSRuntime* rt) {
#if !JS_HAS_INTL_API
/*
* The free also releases the memory for decimalSeparator and numGrouping
* strings.
*/
char* storage = const_cast<char*>(rt->thousandsSeparator.ref());
js_free(storage);
#endif // !JS_HAS_INTL_API
}
JSObject* NumberObject::createPrototype(JSContext* cx, JSProtoKey key) {
NumberObject* numberProto =
GlobalObject::createBlankPrototype<NumberObject>(cx, cx->global());
if (!numberProto) {
return nullptr;
}
numberProto->setPrimitiveValue(0);
return numberProto;
}
static bool NumberClassFinish(JSContext* cx, HandleObject ctor,
HandleObject proto) {
Handle<GlobalObject*> global = cx->global();
if (!JS_DefineFunctions(cx, global, number_functions)) {
return false;
}
// Number.parseInt should be the same function object as global parseInt.
RootedId parseIntId(cx, NameToId(cx->names().parseInt));
JSFunction* parseInt =
DefineFunction(cx, global, parseIntId, num_parseInt, 2, JSPROP_RESOLVING);
if (!parseInt) {
return false;
}
parseInt->setJitInfo(&jit::JitInfo_NumberParseInt);
RootedValue parseIntValue(cx, ObjectValue(*parseInt));
if (!DefineDataProperty(cx, ctor, parseIntId, parseIntValue, 0)) {
return false;
}
// Number.parseFloat should be the same function object as global
// parseFloat.
RootedId parseFloatId(cx, NameToId(cx->names().parseFloat));
JSFunction* parseFloat = DefineFunction(cx, global, parseFloatId,
num_parseFloat, 1, JSPROP_RESOLVING);
if (!parseFloat) {
return false;
}
RootedValue parseFloatValue(cx, ObjectValue(*parseFloat));
if (!DefineDataProperty(cx, ctor, parseFloatId, parseFloatValue, 0)) {
return false;
}
RootedValue valueNaN(cx, JS::NaNValue());
RootedValue valueInfinity(cx, JS::InfinityValue());
if (!DefineDataProperty(
cx, ctor, cx->names().NaN, valueNaN,
JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING)) {
return false;
}
// ES5 15.1.1.1, 15.1.1.2
if (!NativeDefineDataProperty(
cx, global, cx->names().NaN, valueNaN,
JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING) ||
!NativeDefineDataProperty(
cx, global, cx->names().Infinity, valueInfinity,
JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING)) {
return false;
}
return true;
}
const ClassSpec NumberObject::classSpec_ = {
GenericCreateConstructor<Number, 1, gc::AllocKind::FUNCTION,
&jit::JitInfo_Number>,
NumberObject::createPrototype,
number_static_methods,
number_static_properties,
number_methods,
nullptr,
NumberClassFinish,
};
static char* FracNumberToCString(ToCStringBuf* cbuf, double d, size_t* len) {
#ifdef DEBUG
{
int32_t _;
MOZ_ASSERT(!NumberEqualsInt32(d, &_));
}
#endif
/*
* This is V8's implementation of the algorithm described in the
* following paper:
*
* Printing floating-point numbers quickly and accurately with integers.
* Florian Loitsch, PLDI 2010.
*/
const double_conversion::DoubleToStringConverter& converter =
double_conversion::DoubleToStringConverter::EcmaScriptConverter();
double_conversion::StringBuilder builder(cbuf->sbuf, std::size(cbuf->sbuf));
converter.ToShortest(d, &builder);
*len = builder.position();
return builder.Finalize();
}
void JS::NumberToString(double d, char (&out)[MaximumNumberToStringLength]) {
int32_t i;
if (NumberEqualsInt32(d, &i)) {
Int32ToCStringBuf cbuf;
size_t len;
char* loc = ::Int32ToCString(&cbuf, i, &len);
memmove(out, loc, len);
out[len] = '\0';
} else {
const double_conversion::DoubleToStringConverter& converter =
double_conversion::DoubleToStringConverter::EcmaScriptConverter();
double_conversion::StringBuilder builder(out, sizeof(out));
converter.ToShortest(d, &builder);
#ifdef DEBUG
char* result =
#endif
builder.Finalize();
MOZ_ASSERT(out == result);
}
}
char* js::NumberToCString(ToCStringBuf* cbuf, double d, size_t* length) {
int32_t i;
size_t len;
char* s = NumberEqualsInt32(d, &i) ? ::Int32ToCString(cbuf, i, &len)
: FracNumberToCString(cbuf, d, &len);
MOZ_ASSERT(s);
if (length) {
*length = len;
}
return s;
}
char* js::Int32ToCString(Int32ToCStringBuf* cbuf, int32_t value,
size_t* length) {
size_t len;
char* s = ::Int32ToCString(cbuf, value, &len);
MOZ_ASSERT(s);
if (length) {
*length = len;
}
return s;
}
char* js::Uint32ToCString(Int32ToCStringBuf* cbuf, uint32_t value,
size_t* length) {
size_t len;
char* s = ::Int32ToCString(cbuf, value, &len);
MOZ_ASSERT(s);
if (length) {
*length = len;
}
return s;
}
char* js::Uint32ToHexCString(Int32ToCStringBuf* cbuf, uint32_t value,
size_t* length) {
size_t len;
char* s = ::Int32ToCString<uint32_t, 16>(cbuf, value, &len);
MOZ_ASSERT(s);
if (length) {
*length = len;
}
return s;
}
template <AllowGC allowGC>
static JSString* NumberToStringWithBase(JSContext* cx, double d, int base) {
MOZ_ASSERT(2 <= base && base <= 36);
Realm* realm = cx->realm();
int32_t i;
if (NumberEqualsInt32(d, &i)) {
bool isBase10Int = (base == 10);
if (isBase10Int) {
static_assert(StaticStrings::INT_STATIC_LIMIT > 10 * 10);
if (StaticStrings::hasInt(i)) {
return cx->staticStrings().getInt(i);
}
} else if (unsigned(i) < unsigned(base)) {
if (i < 10) {
return cx->staticStrings().getInt(i);
}
char16_t c = 'a' + i - 10;
MOZ_ASSERT(StaticStrings::hasUnit(c));
return cx->staticStrings().getUnit(c);
} else if (unsigned(i) < unsigned(base * base)) {
static constexpr char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
char chars[] = {digits[i / base], digits[i % base]};
JSString* str = cx->staticStrings().lookup(chars, 2);
MOZ_ASSERT(str);
return str;
}
if (JSLinearString* str = realm->dtoaCache.lookup(base, d)) {
return str;
}
// Plus three to include the largest number, the sign, and the terminating
// null character.
constexpr size_t MaximumLength = std::numeric_limits<int32_t>::digits + 3;
char buf[MaximumLength] = {};
size_t numStrLen;
char* numStr = Int32ToCStringWithBase(buf, i, &numStrLen, base);
MOZ_ASSERT(numStrLen == strlen(numStr));
JSLinearString* s = NewStringCopyN<allowGC>(cx, numStr, numStrLen);
if (!s) {
return nullptr;
}
if (isBase10Int && i >= 0) {
s->maybeInitializeIndexValue(i);
}
realm->dtoaCache.cache(base, d, s);
return s;
}
if (JSLinearString* str = realm->dtoaCache.lookup(base, d)) {
return str;
}
JSLinearString* s;
if (base == 10) {
// We use a faster algorithm for base 10.
ToCStringBuf cbuf;
size_t numStrLen;
char* numStr = FracNumberToCString(&cbuf, d, &numStrLen);
MOZ_ASSERT(numStr);
MOZ_ASSERT(numStrLen == strlen(numStr));
s = NewStringCopyN<allowGC>(cx, numStr, numStrLen);
if (!s) {
return nullptr;
}
} else {
if (!EnsureDtoaState(cx)) {
if constexpr (allowGC) {
ReportOutOfMemory(cx);
}
return nullptr;
}
UniqueChars numStr(js_dtobasestr(cx->dtoaState, base, d));
if (!numStr) {
if constexpr (allowGC) {
ReportOutOfMemory(cx);
}
return nullptr;
}
s = NewStringCopyZ<allowGC>(cx, numStr.get());
if (!s) {
return nullptr;
}
}
realm->dtoaCache.cache(base, d, s);
return s;
}
template <AllowGC allowGC>
JSString* js::NumberToString(JSContext* cx, double d) {
return NumberToStringWithBase<allowGC>(cx, d, 10);
}
template JSString* js::NumberToString<CanGC>(JSContext* cx, double d);
template JSString* js::NumberToString<NoGC>(JSContext* cx, double d);
JSString* js::NumberToStringPure(JSContext* cx, double d) {
AutoUnsafeCallWithABI unsafe;
return NumberToString<NoGC>(cx, d);
}
JSAtom* js::NumberToAtom(JSContext* cx, double d) {
int32_t si;
if (NumberEqualsInt32(d, &si)) {
return Int32ToAtom(cx, si);
}
if (JSLinearString* str = LookupDtoaCache(cx, d)) {
return AtomizeString(cx, str);
}
ToCStringBuf cbuf;
size_t length;
char* numStr = FracNumberToCString(&cbuf, d, &length);
MOZ_ASSERT(numStr);
MOZ_ASSERT(std::begin(cbuf.sbuf) <= numStr && numStr < std::end(cbuf.sbuf));
MOZ_ASSERT(length == strlen(numStr));
JSAtom* atom = Atomize(cx, numStr, length);
if (!atom) {
return nullptr;
}
CacheNumber(cx, d, atom);
return atom;
}
frontend::TaggedParserAtomIndex js::NumberToParserAtom(
FrontendContext* fc, frontend::ParserAtomsTable& parserAtoms, double d) {
int32_t si;
if (NumberEqualsInt32(d, &si)) {
return Int32ToParserAtom(fc, parserAtoms, si);
}
ToCStringBuf cbuf;
size_t length;
char* numStr = FracNumberToCString(&cbuf, d, &length);
MOZ_ASSERT(numStr);
MOZ_ASSERT(std::begin(cbuf.sbuf) <= numStr && numStr < std::end(cbuf.sbuf));
MOZ_ASSERT(length == strlen(numStr));
return parserAtoms.internAscii(fc, numStr, length);
}
JSLinearString* js::IndexToString(JSContext* cx, uint32_t index) {
if (StaticStrings::hasUint(index)) {
return cx->staticStrings().getUint(index);
}
Realm* realm = cx->realm();
if (JSLinearString* str = realm->dtoaCache.lookup(10, index)) {
return str;
}
Latin1Char buffer[JSFatInlineString::MAX_LENGTH_LATIN1 + 1];
RangedPtr<Latin1Char> end(buffer + JSFatInlineString::MAX_LENGTH_LATIN1,
buffer, JSFatInlineString::MAX_LENGTH_LATIN1 + 1);
*end = '\0';
RangedPtr<Latin1Char> start = BackfillIndexInCharBuffer(index, end);
mozilla::Range<const Latin1Char> chars(start.get(), end - start);
JSInlineString* str =
NewInlineString<CanGC>(cx, chars, js::gc::Heap::Default);
if (!str) {
return nullptr;
}
realm->dtoaCache.cache(10, index, str);
return str;
}
JSString* js::Int32ToStringWithBase(JSContext* cx, int32_t i, int32_t base,
bool lowerCase) {
Rooted<JSString*> str(cx, NumberToStringWithBase<CanGC>(cx, double(i), base));
if (!str) {
return nullptr;
}
if (lowerCase) {
return str;
}
return StringToUpperCase(cx, str);
}
bool js::NumberValueToStringBuilder(const Value& v, StringBuilder& sb) {
/* Convert to C-string. */
ToCStringBuf cbuf;
const char* cstr;
size_t cstrlen;
if (v.isInt32()) {
cstr = ::Int32ToCString(&cbuf, v.toInt32(), &cstrlen);
} else {
cstr = NumberToCString(&cbuf, v.toDouble(), &cstrlen);
}
MOZ_ASSERT(cstr);
MOZ_ASSERT(cstrlen == strlen(cstr));
MOZ_ASSERT(cstrlen < std::size(cbuf.sbuf));
return sb.append(cstr, cstrlen);
}
template <typename CharT>
inline double CharToNumber(CharT c) {
if ('0' <= c && c <= '9') {
return c - '0';
}
if (unicode::IsSpace(c)) {
return 0.0;
}
return GenericNaN();
}
template <typename CharT>
inline bool CharsToNonDecimalNumber(const CharT* start, const CharT* end,
double* result) {
MOZ_ASSERT(end - start >= 2);
MOZ_ASSERT(start[0] == '0');
int radix = 0;
if (start[1] == 'b' || start[1] == 'B') {
radix = 2;
} else if (start[1] == 'o' || start[1] == 'O') {
radix = 8;
} else if (start[1] == 'x' || start[1] == 'X') {
radix = 16;
} else {
return false;
}
// It's probably a non-decimal number. Accept if there's at least one digit
// after the 0b|0o|0x, and if no non-whitespace characters follow all the
// digits.
const CharT* endptr;
double d;
MOZ_ALWAYS_TRUE(GetPrefixIntegerImpl(
start + 2, end, radix, IntegerSeparatorHandling::None, &endptr, &d));
if (endptr == start + 2 || SkipSpace(endptr, end) != end) {
*result = GenericNaN();
} else {
*result = d;
}
return true;
}
template <typename CharT>
double js::CharsToNumber(const CharT* chars, size_t length) {
if (length == 1) {
return CharToNumber(chars[0]);
}
const CharT* end = chars + length;
const CharT* start = SkipSpace(chars, end);
if (end - start >= 2 && start[0] == '0') {
double d;
if (CharsToNonDecimalNumber(start, end, &d)) {
return d;
}
}
/*
* Note that ECMA doesn't treat a string beginning with a '0' as
* an octal number here. This works because all such numbers will
* be interpreted as decimal by js_strtod. Also, any hex numbers
* that have made it here (which can only be negative ones) will
* be treated as 0 without consuming the 'x' by js_strtod.
*/
const CharT* ep;
double d = js_strtod(start, end, &ep);
if (SkipSpace(ep, end) != end) {
return GenericNaN();
}
return d;
}
template double js::CharsToNumber(const Latin1Char* chars, size_t length);
template double js::CharsToNumber(const char16_t* chars, size_t length);
double js::LinearStringToNumber(const JSLinearString* str) {
if (str->hasIndexValue()) {
return str->getIndexValue();
}
AutoCheckCannotGC nogc;
return str->hasLatin1Chars()
? CharsToNumber(str->latin1Chars(nogc), str->length())
: CharsToNumber(str->twoByteChars(nogc), str->length());
}
bool js::StringToNumber(JSContext* cx, JSString* str, double* result) {
JSLinearString* linearStr = str->ensureLinear(cx);
if (!linearStr) {
return false;
}
*result = LinearStringToNumber(linearStr);
return true;
}
bool js::StringToNumberPure(JSContext* cx, JSString* str, double* result) {
// IC Code calls this directly.
AutoUnsafeCallWithABI unsafe;
if (!StringToNumber(cx, str, result)) {
cx->recoverFromOutOfMemory();
return false;
}
return true;
}
JS_PUBLIC_API bool js::ToNumberSlow(JSContext* cx, HandleValue v_,
double* out) {
RootedValue v(cx, v_);
MOZ_ASSERT(!v.isNumber());
if (!v.isPrimitive()) {
if (!ToPrimitive(cx, JSTYPE_NUMBER, &v)) {
return false;
}
if (v.isNumber()) {
*out = v.toNumber();
return true;
}
}
if (v.isString()) {
return StringToNumber(cx, v.toString(), out);
}
if (v.isBoolean()) {
*out = v.toBoolean() ? 1.0 : 0.0;
return true;
}
if (v.isNull()) {
*out = 0.0;
return true;
}
if (v.isUndefined()) {
*out = GenericNaN();
return true;
}
#ifdef ENABLE_RECORD_TUPLE
if (v.isExtendedPrimitive()) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_RECORD_TUPLE_TO_NUMBER);
return false;
}
#endif
MOZ_ASSERT(v.isSymbol() || v.isBigInt());
unsigned errnum = JSMSG_SYMBOL_TO_NUMBER;
if (v.isBigInt()) {
errnum = JSMSG_BIGINT_TO_NUMBER;
}
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, errnum);
return false;
}
// BigInt proposal section 3.1.6
bool js::ToNumericSlow(JSContext* cx, MutableHandleValue vp) {
MOZ_ASSERT(!vp.isNumeric());
// Step 1.
if (!vp.isPrimitive()) {
if (!ToPrimitive(cx, JSTYPE_NUMBER, vp)) {
return false;
}
}
// Step 2.
if (vp.isBigInt()) {
return true;
}
// Step 3.
return ToNumber(cx, vp);
}
/*
* Convert a value to an int8_t, according to the WebIDL rules for byte
* conversion. Return converted value in *out on success, false on failure.
*/
JS_PUBLIC_API bool js::ToInt8Slow(JSContext* cx, const HandleValue v,
int8_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToInt8(d);
return true;
}
/*
* Convert a value to an uint8_t, according to the ToUInt8() function in ES6
* ECMA-262, 7.1.10. Return converted value in *out on success, false on
* failure.
*/
JS_PUBLIC_API bool js::ToUint8Slow(JSContext* cx, const HandleValue v,
uint8_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToUint8(d);
return true;
}
/*
* Convert a value to an int16_t, according to the WebIDL rules for short
* conversion. Return converted value in *out on success, false on failure.
*/
JS_PUBLIC_API bool js::ToInt16Slow(JSContext* cx, const HandleValue v,
int16_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToInt16(d);
return true;
}
/*
* Convert a value to an int64_t, according to the WebIDL rules for long long
* conversion. Return converted value in *out on success, false on failure.
*/
JS_PUBLIC_API bool js::ToInt64Slow(JSContext* cx, const HandleValue v,
int64_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToInt64(d);
return true;
}
/*
* Convert a value to an uint64_t, according to the WebIDL rules for unsigned
* long long conversion. Return converted value in *out on success, false on
* failure.
*/
JS_PUBLIC_API bool js::ToUint64Slow(JSContext* cx, const HandleValue v,
uint64_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToUint64(d);
return true;
}
JS_PUBLIC_API bool js::ToInt32Slow(JSContext* cx, const HandleValue v,
int32_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToInt32(d);
return true;
}
bool js::ToInt32OrBigIntSlow(JSContext* cx, MutableHandleValue vp) {
MOZ_ASSERT(!vp.isInt32());
if (vp.isDouble()) {
vp.setInt32(ToInt32(vp.toDouble()));
return true;
}
if (!ToNumeric(cx, vp)) {
return false;
}
if (vp.isBigInt()) {
return true;
}
vp.setInt32(ToInt32(vp.toNumber()));
return true;
}
JS_PUBLIC_API bool js::ToUint32Slow(JSContext* cx, const HandleValue v,
uint32_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumberSlow(cx, v, &d)) {
return false;
}
}
*out = ToUint32(d);
return true;
}
JS_PUBLIC_API bool js::ToUint16Slow(JSContext* cx, const HandleValue v,
uint16_t* out) {
MOZ_ASSERT(!v.isInt32());
double d;
if (v.isDouble()) {
d = v.toDouble();
} else if (!ToNumberSlow(cx, v, &d)) {
return false;
}
*out = ToUint16(d);
return true;
}
// ES2017 draft 7.1.17 ToIndex
bool js::ToIndexSlow(JSContext* cx, JS::HandleValue v,
const unsigned errorNumber, uint64_t* index) {
MOZ_ASSERT_IF(v.isInt32(), v.toInt32() < 0);
// Step 1.
if (v.isUndefined()) {
*index = 0;
return true;
}
// Step 2.a.
double integerIndex;
if (!ToInteger(cx, v, &integerIndex)) {
return false;
}
// Inlined version of ToLength.
// 1. Already an integer.
// 2. Step eliminates < 0, +0 == -0 with SameValueZero.
// 3/4. Limit to <= 2^53-1, so everything above should fail.
if (integerIndex < 0 || integerIndex >= DOUBLE_INTEGRAL_PRECISION_LIMIT) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, errorNumber);
return false;
}
// Step 3.
*index = uint64_t(integerIndex);
return true;
}
template <typename CharT>
double js_strtod(const CharT* begin, const CharT* end, const CharT** dEnd) {
const CharT* s = SkipSpace(begin, end);
size_t length = end - s;
{
// StringToDouble can make indirect calls but can't trigger a GC.
JS::AutoSuppressGCAnalysis nogc;
using SToDConverter = double_conversion::StringToDoubleConverter;
SToDConverter converter(SToDConverter::ALLOW_TRAILING_JUNK,
/* empty_string_value = */ 0.0,
/* junk_string_value = */ GenericNaN(),
/* infinity_symbol = */ nullptr,
/* nan_symbol = */ nullptr);
int lengthInt = mozilla::AssertedCast<int>(length);
double d;
int processed = 0;
if constexpr (std::is_same_v<CharT, char16_t>) {
d = converter.StringToDouble(reinterpret_cast<const uc16*>(s), lengthInt,
&processed);
} else {
static_assert(std::is_same_v<CharT, Latin1Char>);
d = converter.StringToDouble(reinterpret_cast<const char*>(s), lengthInt,
&processed);
}
MOZ_ASSERT(processed >= 0);
MOZ_ASSERT(processed <= lengthInt);
if (processed > 0) {
*dEnd = s + processed;
return d;
}
}
// Try to parse +Infinity, -Infinity or Infinity. Note that we do this here
// instead of using StringToDoubleConverter's infinity_symbol because it's
// faster: the code below is less generic and not on the fast path for regular
// doubles.
static constexpr std::string_view Infinity = "Infinity";
if (length >= Infinity.length()) {
const CharT* afterSign = s;
bool negative = (*afterSign == '-');
if (negative || *afterSign == '+') {
afterSign++;
}
MOZ_ASSERT(afterSign < end);
if (*afterSign == 'I' && size_t(end - afterSign) >= Infinity.length() &&
EqualChars(afterSign, Infinity.data(), Infinity.length())) {
*dEnd = afterSign + Infinity.length();
return negative ? NegativeInfinity<double>() : PositiveInfinity<double>();
}
}
*dEnd = begin;
return 0.0;
}
template double js_strtod(const char16_t* begin, const char16_t* end,
const char16_t** dEnd);
template double js_strtod(const Latin1Char* begin, const Latin1Char* end,
const Latin1Char** dEnd);