/* -*- 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 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef jsnum_h #define jsnum_h #include "mozilla/FloatingPoint.h" #include "mozilla/Range.h" #include "mozilla/Utf8.h" #include #include "NamespaceImports.h" #include "js/Conversions.h" #include "js/friend/ErrorMessages.h" // JSMSG_* #include "vm/StringType.h" namespace js { namespace frontend { class ParserAtomsTable; class TaggedParserAtomIndex; } // namespace frontend class GlobalObject; class StringBuffer; [[nodiscard]] extern bool InitRuntimeNumberState(JSRuntime* rt); // This is a no-op if built with JS_HAS_INTL_API. extern void FinishRuntimeNumberState(JSRuntime* rt); /* * This function implements ToString() as specified by ECMA-262-5 section 9.8.1; * but note that it handles integers specially for performance. * See also js::NumberToCString(). */ template extern JSString* NumberToString(JSContext* cx, double d); extern JSString* NumberToStringPure(JSContext* cx, double d); extern JSAtom* NumberToAtom(JSContext* cx, double d); frontend::TaggedParserAtomIndex NumberToParserAtom( FrontendContext* fc, frontend::ParserAtomsTable& parserAtoms, double d); template extern JSLinearString* Int32ToString(JSContext* cx, int32_t i); template extern JSLinearString* Int32ToStringWithHeap(JSContext* cx, int32_t i, gc::Heap heap); extern JSLinearString* Int32ToStringPure(JSContext* cx, int32_t i); extern JSString* Int32ToStringWithBase(JSContext* cx, int32_t i, int32_t base, bool lowerCase); extern JSAtom* Int32ToAtom(JSContext* cx, int32_t si); frontend::TaggedParserAtomIndex Int32ToParserAtom( FrontendContext* fc, frontend::ParserAtomsTable& parserAtoms, int32_t si); // ES6 15.7.3.12 extern bool IsInteger(double d); /* * Convert an integer or double (contained in the given value) to a string and * append to the given buffer. */ [[nodiscard]] extern bool NumberValueToStringBuffer(const Value& v, StringBuffer& sb); extern JSLinearString* IndexToString(JSContext* cx, uint32_t index); struct ToCStringBuf { char sbuf[JS::MaximumNumberToStringLength] = {}; }; struct Int32ToCStringBuf { // The amount of space large enough to store the null-terminated result of // |ToString| on any int32. // // We use the same amount for uint32 (base 10 and base 16), even though uint32 // only need 11 characters (base 10) resp. 9 characters (base 16) instead of // 12 characters for int32 in base 10. static constexpr size_t MaximumInt32ToStringLength = std::numeric_limits::digits10 + 1 + // account for the largest possible int32 value 1 + // sign for negative numbers 1 // null character ; char sbuf[MaximumInt32ToStringLength] = {}; }; // Convert a number to a C string. This function implements ToString() as // specified by ECMA-262-5 section 9.8.1. It handles integral values cheaply. // Infallible: always returns a non-nullptr string. // The optional `length` out-param is set to the string length of the result. extern char* NumberToCString(ToCStringBuf* cbuf, double d, size_t* length = nullptr); extern char* Int32ToCString(Int32ToCStringBuf* cbuf, int32_t value, size_t* length = nullptr); extern char* Uint32ToCString(Int32ToCStringBuf* cbuf, uint32_t value, size_t* length = nullptr); // Like NumberToCString, but accepts only unsigned integers and uses base 16. // Infallible: always returns a non-nullptr string. // The optional `length` out-param is set to the string length of the result. extern char* Uint32ToHexCString(Int32ToCStringBuf* cbuf, uint32_t value, size_t* length = nullptr); /* * The largest positive integer such that all positive integers less than it * may be precisely represented using the IEEE-754 double-precision format. */ constexpr double DOUBLE_INTEGRAL_PRECISION_LIMIT = uint64_t(1) << 53; /* * The smallest positive double such that all positive doubles larger or equal * than it have an exact decimal representation without exponential form. */ constexpr double DOUBLE_DECIMAL_IN_SHORTEST_LOW = 1.0e-6; /* * The largest positive double such that all positive doubles less than it * have an exact decimal representation without exponential form. */ constexpr double DOUBLE_DECIMAL_IN_SHORTEST_HIGH = 1.0e21; /* * Parse a decimal number encoded in |chars|. The decimal number must be * sufficiently small that it will not overflow the integrally-precise range of * the double type -- that is, the number will be smaller than * DOUBLE_INTEGRAL_PRECISION_LIMIT */ template extern double ParseDecimalNumber(const mozilla::Range chars); enum class IntegerSeparatorHandling : bool { None, SkipUnderscore }; /* * Compute the positive integer of the given base described immediately at the * start of the range [start, end) -- no whitespace-skipping, no magical * leading-"0" octal or leading-"0x" hex behavior, no "+"/"-" parsing, just * reading the digits of the integer. Return the index one past the end of the * digits of the integer in *endp, and return the integer itself in *dp. If * base is 10 or a power of two the returned integer is the closest possible * double; otherwise extremely large integers may be slightly inaccurate. * * The |separatorHandling| controls whether or not numeric separators can be * part of integer string. If the option is enabled, all '_' characters in the * string are ignored. Underscore characters must not appear directly next to * each other, e.g. '1__2' will lead to an assertion. * * If [start, end) does not begin with a number with the specified base, * *dp == 0 and *endp == start upon return. */ template [[nodiscard]] extern bool GetPrefixInteger( const CharT* start, const CharT* end, int base, IntegerSeparatorHandling separatorHandling, const CharT** endp, double* dp); inline const char16_t* ToRawChars(const char16_t* units) { return units; } inline const unsigned char* ToRawChars(const unsigned char* units) { return units; } inline const unsigned char* ToRawChars(const mozilla::Utf8Unit* units) { return mozilla::Utf8AsUnsignedChars(units); } /** * Like GetPrefixInteger, but [start, end) must all be digits in the given * base (and so this function doesn't take a useless outparam). */ template [[nodiscard]] extern bool GetFullInteger( const CharT* start, const CharT* end, int base, IntegerSeparatorHandling separatorHandling, double* dp) { decltype(ToRawChars(start)) realEnd; if (GetPrefixInteger(ToRawChars(start), ToRawChars(end), base, separatorHandling, &realEnd, dp)) { MOZ_ASSERT(end == static_cast(realEnd)); return true; } return false; } /* * This is like GetPrefixInteger, but only deals with base 10, always ignores * '_', and doesn't have an |endp| outparam. It should only be used when the * characters are known to match |DecimalIntegerLiteral|, cf. ES2020, 11.8.3 * Numeric Literals. */ template [[nodiscard]] extern bool GetDecimalInteger(const CharT* start, const CharT* end, double* dp); /* * This is like GetDecimalInteger, but also allows non-integer numbers. It * should only be used when the characters are known to match |DecimalLiteral|, * cf. ES2020, 11.8.3 Numeric Literals. */ template [[nodiscard]] extern bool GetDecimal(const CharT* start, const CharT* end, double* dp); template double CharsToNumber(const CharT* chars, size_t length); [[nodiscard]] extern bool StringToNumber(JSContext* cx, JSString* str, double* result); [[nodiscard]] extern bool StringToNumberPure(JSContext* cx, JSString* str, double* result); // Infallible version of StringToNumber for linear strings. extern double LinearStringToNumber(JSLinearString* str); // Parse the input string as if Number.parseInt had been called. extern bool NumberParseInt(JSContext* cx, JS::HandleString str, int32_t radix, JS::MutableHandleValue result); /* ES5 9.3 ToNumber, overwriting *vp with the appropriate number value. */ [[nodiscard]] MOZ_ALWAYS_INLINE bool ToNumber(JSContext* cx, JS::MutableHandleValue vp) { if (vp.isNumber()) { return true; } double d; extern JS_PUBLIC_API bool ToNumberSlow(JSContext * cx, HandleValue v, double* dp); if (!ToNumberSlow(cx, vp, &d)) { return false; } vp.setNumber(d); return true; } bool ToNumericSlow(JSContext* cx, JS::MutableHandleValue vp); // BigInt proposal section 3.1.6 [[nodiscard]] MOZ_ALWAYS_INLINE bool ToNumeric(JSContext* cx, JS::MutableHandleValue vp) { if (vp.isNumeric()) { return true; } return ToNumericSlow(cx, vp); } bool ToInt32OrBigIntSlow(JSContext* cx, JS::MutableHandleValue vp); [[nodiscard]] MOZ_ALWAYS_INLINE bool ToInt32OrBigInt( JSContext* cx, JS::MutableHandleValue vp) { if (vp.isInt32()) { return true; } return ToInt32OrBigIntSlow(cx, vp); } } /* namespace js */ /* * Similar to strtod except that it replaces overflows with infinities of the * correct sign, and underflows with zeros of the correct sign. Guaranteed to * return the closest double number to the given input. * * Also allows inputs of the form [+|-]Infinity, which produce an infinity of * the appropriate sign. The case of the "Infinity" string must match exactly. * If the string does not contain a number, set *dEnd to begin and return 0.0. */ template [[nodiscard]] extern double js_strtod(const CharT* begin, const CharT* end, const CharT** dEnd); namespace js { /** * Like js_strtod, but for when the number always constitutes the entire range * (and so |dEnd| would be a value already known). */ template [[nodiscard]] extern double FullStringToDouble(const CharT* begin, const CharT* end) { decltype(ToRawChars(begin)) realEnd; double d = js_strtod(ToRawChars(begin), ToRawChars(end), &realEnd); MOZ_ASSERT(end == static_cast(realEnd)); return d; } [[nodiscard]] extern bool ThisNumberValueForToLocaleString(JSContext* cx, unsigned argc, Value* vp); [[nodiscard]] extern bool num_valueOf(JSContext* cx, unsigned argc, Value* vp); /* * Returns true if the given value is definitely an index: that is, the value * is a number that's an unsigned 32-bit integer. * * This method prioritizes common-case speed over accuracy in every case. It * can produce false negatives (but not false positives): some values which are * indexes will be reported not to be indexes by this method. Users must * consider this possibility when using this method. */ static MOZ_ALWAYS_INLINE bool IsDefinitelyIndex(const Value& v, uint32_t* indexp) { if (v.isInt32() && v.toInt32() >= 0) { *indexp = v.toInt32(); return true; } int32_t i; if (v.isDouble() && mozilla::NumberEqualsInt32(v.toDouble(), &i) && i >= 0) { *indexp = uint32_t(i); return true; } if (v.isString() && v.toString()->hasIndexValue()) { *indexp = v.toString()->getIndexValue(); return true; } return false; } // ES2020 draft rev 6b05bc56ba4e3c7a2b9922c4282d9eb844426d9b // 7.1.5 ToInteger ( argument ) [[nodiscard]] static inline bool ToInteger(JSContext* cx, HandleValue v, double* dp) { if (v.isInt32()) { *dp = v.toInt32(); return true; } if (v.isDouble()) { *dp = v.toDouble(); } else if (v.isString() && v.toString()->hasIndexValue()) { *dp = v.toString()->getIndexValue(); return true; } else { extern JS_PUBLIC_API bool ToNumberSlow(JSContext * cx, HandleValue v, double* dp); if (!ToNumberSlow(cx, v, dp)) { return false; } } *dp = JS::ToInteger(*dp); return true; } /* ES2017 draft 7.1.17 ToIndex * * Return true and set |*index| to the integer value if |v| is a valid * integer index value. Otherwise report a RangeError and return false. * * The returned index will always be in the range 0 <= *index <= 2^53-1. */ [[nodiscard]] extern bool ToIndexSlow(JSContext* cx, JS::HandleValue v, const unsigned errorNumber, uint64_t* index); [[nodiscard]] static inline bool ToIndex(JSContext* cx, JS::HandleValue v, const unsigned errorNumber, uint64_t* index) { if (v.isInt32()) { int32_t i = v.toInt32(); if (i >= 0) { *index = uint64_t(i); return true; } } return ToIndexSlow(cx, v, errorNumber, index); } [[nodiscard]] static inline bool ToIndex(JSContext* cx, JS::HandleValue v, uint64_t* index) { return ToIndex(cx, v, JSMSG_BAD_INDEX, index); } } /* namespace js */ #endif /* jsnum_h */