/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=8 sts=4 et sw=4 tw=99: * 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/. */ /* * JS number type and wrapper class. */ #include "jsnum.h" #include "mozilla/double-conversion.h" #include "mozilla/FloatingPoint.h" #include "mozilla/PodOperations.h" #include "mozilla/RangedPtr.h" #ifdef HAVE_LOCALECONV #include #endif #include #include #include "jsatom.h" #include "jscntxt.h" #include "jsdtoa.h" #include "jsobj.h" #include "jsstr.h" #include "jstypes.h" #include "js/Conversions.h" #include "vm/GlobalObject.h" #include "vm/StringBuffer.h" #include "jsatominlines.h" #include "vm/NativeObject-inl.h" #include "vm/NumberObject-inl.h" #include "vm/String-inl.h" using namespace js; using mozilla::Abs; using mozilla::ArrayLength; using mozilla::MinNumberValue; using mozilla::NegativeInfinity; using mozilla::PodCopy; using mozilla::PositiveInfinity; using mozilla::RangedPtr; using JS::AutoCheckCannotGC; using JS::GenericNaN; using JS::ToInt8; using JS::ToInt16; using JS::ToInt32; using JS::ToInt64; using JS::ToUint32; using JS::ToUint64; /* * If we're accumulating a decimal number and the number is >= 2^53, then the * fast result from the loop in Get{Prefix,Decimal}Integer may be inaccurate. * Call js_strtod_harder to get the correct answer. */ template static bool ComputeAccurateDecimalInteger(ExclusiveContext* cx, const CharT* start, const CharT* end, double* dp) { size_t length = end - start; ScopedJSFreePtr cstr(cx->pod_malloc(length + 1)); if (!cstr) return false; for (size_t i = 0; i < length; i++) { char c = char(start[i]); MOZ_ASSERT(('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z')); cstr[i] = c; } cstr[length] = 0; char* estr; int err = 0; *dp = js_strtod_harder(cx->dtoaState(), cstr, &estr, &err); if (err == JS_DTOA_ENOMEM) { ReportOutOfMemory(cx); return false; } return true; } namespace { template 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* start; /* Pointer to the remaining digits */ const CharT* end; /* Pointer to first non-digit */ public: BinaryDigitReader(int base, const CharT* start, const CharT* end) : base(base), digit(0), digitMask(0), start(start), end(end) { } /* Return the next binary digit from the number, or -1 if done. */ int nextDigit() { if (digitMask == 0) { if (start == end) return -1; int c = *start++; MOZ_ASSERT(('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z')); if ('0' <= c && c <= '9') digit = c - '0'; else if ('a' <= c && c <= 'z') digit = c - 'a' + 10; else digit = c - 'A' + 10; 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 static double ComputeAccurateBinaryBaseInteger(const CharT* start, const CharT* end, int base) { BinaryDigitReader 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 double js::ParseDecimalNumber(const mozilla::Range chars) { MOZ_ASSERT(chars.length() > 0); uint64_t dec = 0; RangedPtr 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(dec); } template double js::ParseDecimalNumber(const mozilla::Range chars); template double js::ParseDecimalNumber(const mozilla::Range chars); template bool js::GetPrefixInteger(ExclusiveContext* cx, const CharT* start, const CharT* end, int base, 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++) { int digit; CharT c = *s; if ('0' <= c && c <= '9') digit = c - '0'; else if ('a' <= c && c <= 'z') digit = c - 'a' + 10; else if ('A' <= c && c <= 'Z') digit = c - 'A' + 10; else break; 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 15.1.2.2 step 13. */ if (base == 10) return ComputeAccurateDecimalInteger(cx, start, s, dp); if ((base & (base - 1)) == 0) *dp = ComputeAccurateBinaryBaseInteger(start, s, base); return true; } template bool js::GetPrefixInteger(ExclusiveContext* cx, const char16_t* start, const char16_t* end, int base, const char16_t** endp, double* dp); template bool js::GetPrefixInteger(ExclusiveContext* cx, const Latin1Char* start, const Latin1Char* end, int base, const Latin1Char** endp, double* dp); bool js::GetDecimalInteger(ExclusiveContext* cx, const char16_t* start, const char16_t* end, double* dp) { MOZ_ASSERT(start <= end); const char16_t* s = start; double d = 0.0; for (; s < end; s++) { char16_t c = *s; MOZ_ASSERT('0' <= c && c <= '9'); int digit = c - '0'; d = d * 10 + digit; } *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. return ComputeAccurateDecimalInteger(cx, start, s, dp); } static bool num_parseFloat(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); if (args.length() == 0) { args.rval().setNaN(); return true; } JSString* str = ToString(cx, args[0]); if (!str) return false; 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; if (!js_strtod(cx, begin, begin + linear->length(), &end, &d)) return false; if (end == begin) d = GenericNaN(); } else { const char16_t* begin = linear->twoByteChars(nogc); const char16_t* end; if (!js_strtod(cx, begin, begin + linear->length(), &end, &d)) return false; if (end == begin) d = GenericNaN(); } args.rval().setDouble(d); return true; } template 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 (!GetPrefixInteger(cx, s, end, radix, &actualEnd, &d)) return false; if (s == actualEnd) *res = GenericNaN(); else *res = negative ? -d : d; return true; } /* ES5 15.1.2.2. */ bool js::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 (1.0e-6 < d && d < 1.0e21) { args.rval().setNumber(floor(d)); return true; } if (-1.0e21 < d && d < -1.0e-6) { args.rval().setNumber(-floor(-d)); return true; } if (d == 0.0) { args.rval().setInt32(0); return true; } } } /* Step 1. */ RootedString inputString(cx, ToString(cx, args[0])); if (!inputString) return false; args[0].setString(inputString); /* Steps 6-9. */ bool stripPrefix = true; int32_t radix; if (!args.hasDefined(1)) { radix = 10; } else { if (!ToInt32(cx, args[1], &radix)) return false; if (radix == 0) { radix = 10; } else { if (radix < 2 || radix > 36) { args.rval().setNaN(); return true; } if (radix != 16) stripPrefix = false; } } JSLinearString* linear = inputString->ensureLinear(cx); if (!linear) return false; AutoCheckCannotGC nogc; size_t length = inputString->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; } args.rval().setNumber(number); return true; } static const JSFunctionSpec number_functions[] = { JS_SELF_HOSTED_FN(js_isNaN_str, "Global_isNaN", 1, JSPROP_RESOLVING), JS_SELF_HOSTED_FN(js_isFinite_str, "Global_isFinite", 1, JSPROP_RESOLVING), JS_FS_END }; const Class NumberObject::class_ = { js_Number_str, JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_HAS_CACHED_PROTO(JSProto_Number) }; static bool Number(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); /* Sample JS_CALLEE before clobbering. */ bool isConstructing = args.isConstructing(); if (args.length() > 0) { if (!ToNumber(cx, args[0])) return false; args.rval().set(args[0]); } else { args.rval().setInt32(0); } if (!isConstructing) return true; RootedObject newTarget(cx, &args.newTarget().toObject()); RootedObject proto(cx); if (!GetPrototypeFromConstructor(cx, newTarget, &proto)) return false; JSObject* obj = NumberObject::create(cx, args.rval().toNumber(), proto); if (!obj) return false; args.rval().setObject(*obj); return true; } MOZ_ALWAYS_INLINE bool IsNumber(HandleValue v) { return v.isNumber() || (v.isObject() && v.toObject().is()); } static inline double Extract(const Value& v) { if (v.isNumber()) return v.toNumber(); return v.toObject().as().unbox(); } #if JS_HAS_TOSOURCE MOZ_ALWAYS_INLINE bool num_toSource_impl(JSContext* cx, const CallArgs& args) { double d = Extract(args.thisv()); StringBuffer sb(cx); if (!sb.append("(new Number(") || !NumberValueToStringBuffer(cx, NumberValue(d), sb) || !sb.append("))")) { return false; } JSString* str = sb.finishString(); if (!str) return false; args.rval().setString(str); return true; } static bool num_toSource(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); return CallNonGenericMethod(cx, args); } #endif ToCStringBuf::ToCStringBuf() : dbuf(nullptr) { static_assert(sbufSize >= DTOSTR_STANDARD_BUFFER_SIZE, "builtin space must be large enough to store even the " "longest string produced by a conversion"); } ToCStringBuf::~ToCStringBuf() { js_free(dbuf); } MOZ_ALWAYS_INLINE static JSFlatString* LookupDtoaCache(ExclusiveContext* cx, double d) { if (JSCompartment* comp = cx->compartment()) { if (JSFlatString* str = comp->dtoaCache.lookup(10, d)) return str; } return nullptr; } MOZ_ALWAYS_INLINE static void CacheNumber(ExclusiveContext* cx, double d, JSFlatString* str) { if (JSCompartment* comp = cx->compartment()) comp->dtoaCache.cache(10, d, str); } MOZ_ALWAYS_INLINE static JSFlatString* LookupInt32ToString(ExclusiveContext* cx, int32_t si) { if (si >= 0 && StaticStrings::hasInt(si)) return cx->staticStrings().getInt(si); return LookupDtoaCache(cx, si); } template 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 end(buffer + size - 1, buffer, size); *end = '\0'; RangedPtr start = BackfillIndexInCharBuffer(ui, end); if (si < 0) *--start = '-'; *length = end - start; return start.get(); } template JSFlatString* js::Int32ToString(ExclusiveContext* cx, int32_t si) { if (JSFlatString* str = LookupInt32ToString(cx, si)) return str; Latin1Char buffer[JSFatInlineString::MAX_LENGTH_LATIN1 + 1]; size_t length; Latin1Char* start = BackfillInt32InBuffer(si, buffer, ArrayLength(buffer), &length); mozilla::Range chars(start, length); JSInlineString* str = NewInlineString(cx, chars); if (!str) return nullptr; CacheNumber(cx, si, str); return str; } template JSFlatString* js::Int32ToString(ExclusiveContext* cx, int32_t si); template JSFlatString* js::Int32ToString(ExclusiveContext* cx, int32_t si); JSAtom* js::Int32ToAtom(ExclusiveContext* cx, int32_t si) { if (JSFlatString* 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); JSAtom* atom = Atomize(cx, start, length); if (!atom) return nullptr; CacheNumber(cx, si, atom); return atom; } /* Returns a non-nullptr pointer to inside cbuf. */ static char* Int32ToCString(ToCStringBuf* cbuf, int32_t i, size_t* len, int base = 10) { uint32_t u = Abs(i); RangedPtr cp(cbuf->sbuf + ToCStringBuf::sbufSize - 1, cbuf->sbuf, ToCStringBuf::sbufSize); 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 (i < 0) *--cp = '-'; *len = end - cp.get(); return cp.get(); } template static JSString* NumberToStringWithBase(ExclusiveContext* cx, double d, int base); MOZ_ALWAYS_INLINE bool num_toString_impl(JSContext* cx, const CallArgs& args) { MOZ_ASSERT(IsNumber(args.thisv())); double d = Extract(args.thisv()); 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(cx, d, base); if (!str) { JS_ReportOutOfMemory(cx); return false; } args.rval().setString(str); return true; } bool js::num_toString(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); return CallNonGenericMethod(cx, args); } MOZ_ALWAYS_INLINE bool num_valueOf_impl(JSContext* cx, const CallArgs& args) { MOZ_ASSERT(IsNumber(args.thisv())); args.rval().setNumber(Extract(args.thisv())); return true; } bool js::num_valueOf(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); return CallNonGenericMethod(cx, args); } 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; if (char* numStr = NumberToCString(cx, &cbuf, prec, 10)) JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_PRECISION_RANGE, numStr); return false; } static bool DToStrResult(JSContext* cx, double d, JSDToStrMode mode, int precision, const CallArgs& args) { char buf[DTOSTR_VARIABLE_BUFFER_SIZE(MAX_PRECISION + 1)]; char* numStr = js_dtostr(cx->mainThread().dtoaState, buf, sizeof buf, mode, precision, d); if (!numStr) { JS_ReportOutOfMemory(cx); return false; } JSString* str = NewStringCopyZ(cx, numStr); if (!str) return false; args.rval().setString(str); return true; } /* * In the following three implementations, we allow a larger range of precision * than ECMA requires; this is permitted by ECMA-262. */ // ES 2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f 20.1.3.3. MOZ_ALWAYS_INLINE bool num_toFixed_impl(JSContext* cx, const CallArgs& args) { // Step 1. MOZ_ASSERT(IsNumber(args.thisv())); double d = Extract(args.thisv()); // Steps 2-3. int precision; if (args.length() == 0) { precision = 0; } else { double prec = 0; if (!ToInteger(cx, args[0], &prec)) return false; if (!ComputePrecisionInRange(cx, -20, MAX_PRECISION, prec, &precision)) return false; } // Step 4. if (mozilla::IsNaN(d)) { args.rval().setString(cx->names().NaN); return true; } // Steps 5-7, 9 (optimized path for Infinity). if (mozilla::IsInfinite(d)) { if(d > 0) { args.rval().setString(cx->names().Infinity); return true; } args.rval().setString(cx->names().NegativeInfinity); return true; } // Steps 5-9. return DToStrResult(cx, Extract(args.thisv()), DTOSTR_FIXED, precision, args); } static bool num_toFixed(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); return CallNonGenericMethod(cx, args); } // ES 2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f 20.1.3.2. MOZ_ALWAYS_INLINE bool num_toExponential_impl(JSContext* cx, const CallArgs& args) { // Step 1. MOZ_ASSERT(IsNumber(args.thisv())); double d = Extract(args.thisv()); // Step 2. double prec = 0; JSDToStrMode mode = DTOSTR_STANDARD_EXPONENTIAL; if (args.hasDefined(0)) { mode = DTOSTR_EXPONENTIAL; if (!ToInteger(cx, args[0], &prec)) return false; } // Step 3. MOZ_ASSERT_IF(!args.hasDefined(0), prec == 0); // Step 4. if (mozilla::IsNaN(d)) { args.rval().setString(cx->names().NaN); return true; } // Steps 5-7. if (mozilla::IsInfinite(d)) { if (d > 0) { args.rval().setString(cx->names().Infinity); return true; } args.rval().setString(cx->names().NegativeInfinity); return true; } // Steps 5-6, 8-15. int precision = 0; if (mode == DTOSTR_EXPONENTIAL) { if (!ComputePrecisionInRange(cx, 0, MAX_PRECISION, prec, &precision)) return false; } return DToStrResult(cx, d, mode, precision + 1, args); } static bool num_toExponential(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); return CallNonGenericMethod(cx, args); } // ES 2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f 20.1.3.5. MOZ_ALWAYS_INLINE bool num_toPrecision_impl(JSContext* cx, const CallArgs& args) { // Step 1. MOZ_ASSERT(IsNumber(args.thisv())); double d = Extract(args.thisv()); // Step 2. if (!args.hasDefined(0)) { JSString* str = NumberToStringWithBase(cx, d, 10); if (!str) { JS_ReportOutOfMemory(cx); return false; } args.rval().setString(str); return true; } // Step 3. double prec = 0; if (!ToInteger(cx, args[0], &prec)) return false; // Step 4. if (mozilla::IsNaN(d)) { args.rval().setString(cx->names().NaN); return true; } // Steps 5-7. if (mozilla::IsInfinite(d)) { if (d > 0) { args.rval().setString(cx->names().Infinity); return true; } args.rval().setString(cx->names().NegativeInfinity); return true; } // Steps 5-6, 8-14. int precision = 0; if (!ComputePrecisionInRange(cx, 1, MAX_PRECISION, prec, &precision)) return false; return DToStrResult(cx, d, DTOSTR_PRECISION, precision, args); } static bool num_toPrecision(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); return CallNonGenericMethod(cx, args); } static const JSFunctionSpec number_methods[] = { #if JS_HAS_TOSOURCE JS_FN(js_toSource_str, num_toSource, 0, 0), #endif JS_FN(js_toString_str, num_toString, 1, 0), JS_SELF_HOSTED_FN(js_toLocaleString_str, "Number_toLocaleString", 0,0), JS_FN(js_valueOf_str, 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 }; // ES6 draft ES6 15.7.3.12 static bool Number_isInteger(JSContext* cx, unsigned argc, Value* vp) { CallArgs args = CallArgsFromVp(argc, vp); if (args.length() < 1 || !args[0].isNumber()) { args.rval().setBoolean(false); return true; } Value val = args[0]; args.rval().setBoolean(val.isInt32() || (mozilla::IsFinite(val.toDouble()) && JS::ToInteger(val.toDouble()) == val.toDouble())); return true; } static const JSFunctionSpec number_static_methods[] = { JS_SELF_HOSTED_FN("isFinite", "Number_isFinite", 1,0), JS_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 }; /* * Set the exception mask to mask all exceptions and set the FPU precision * to 53 bit mantissa (64 bit doubles). */ void js::FIX_FPU() { #if (defined __GNUC__ && defined __i386__) || \ (defined __SUNPRO_CC && defined __i386) short control; asm("fstcw %0" : "=m" (control) : ); control &= ~0x300; // Lower bits 8 and 9 (precision control). control |= 0x2f3; // Raise bits 0-5 (exception masks) and 9 (64-bit precision). asm("fldcw %0" : : "m" (control) ); #endif } void js::InitRuntimeNumberState(JSRuntime* rt) { FIX_FPU(); } JSObject* js::InitNumberClass(JSContext* cx, HandleObject obj) { MOZ_ASSERT(obj->isNative()); /* XXX must do at least once per new thread, so do it per JSContext... */ FIX_FPU(); Rooted global(cx, &obj->as()); RootedObject numberProto(cx, global->createBlankPrototype(cx, &NumberObject::class_)); if (!numberProto) return nullptr; numberProto->as().setPrimitiveValue(0); RootedFunction ctor(cx); ctor = global->createConstructor(cx, Number, cx->names().Number, 1); if (!ctor) return nullptr; if (!LinkConstructorAndPrototype(cx, ctor, numberProto)) return nullptr; /* * Our NaN must be one particular canonical value, because we rely on NaN * encoding for our value representation. See Value.h. */ static JSConstDoubleSpec number_constants[] = { {"NaN", GenericNaN() }, {"POSITIVE_INFINITY", mozilla::PositiveInfinity() }, {"NEGATIVE_INFINITY", mozilla::NegativeInfinity() }, {"MAX_VALUE", 1.7976931348623157E+308 }, {"MIN_VALUE", MinNumberValue() }, /* ES6 (April 2014 draft) 20.1.2.6 */ {"MAX_SAFE_INTEGER", 9007199254740991 }, /* ES6 (April 2014 draft) 20.1.2.10 */ {"MIN_SAFE_INTEGER", -9007199254740991, }, /* ES6 (May 2013 draft) 15.7.3.7 */ {"EPSILON", 2.2204460492503130808472633361816e-16}, {0,0} }; /* Add numeric constants (MAX_VALUE, NaN, &c.) to the Number constructor. */ if (!JS_DefineConstDoubles(cx, ctor, number_constants)) return nullptr; if (!DefinePropertiesAndFunctions(cx, ctor, nullptr, number_static_methods)) return nullptr; if (!DefinePropertiesAndFunctions(cx, numberProto, nullptr, number_methods)) return nullptr; if (!JS_DefineFunctions(cx, global, number_functions)) return nullptr; /* 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 nullptr; RootedValue parseIntValue(cx, ObjectValue(*parseInt)); if (!DefineProperty(cx, ctor, parseIntId, parseIntValue, nullptr, nullptr, 0)) return nullptr; /* 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 nullptr; RootedValue parseFloatValue(cx, ObjectValue(*parseFloat)); if (!DefineProperty(cx, ctor, parseFloatId, parseFloatValue, nullptr, nullptr, 0)) return nullptr; RootedValue valueNaN(cx, cx->runtime()->NaNValue); RootedValue valueInfinity(cx, cx->runtime()->positiveInfinityValue); /* ES5 15.1.1.1, 15.1.1.2 */ if (!NativeDefineProperty(cx, global, cx->names().NaN, valueNaN, nullptr, nullptr, JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING) || !NativeDefineProperty(cx, global, cx->names().Infinity, valueInfinity, nullptr, nullptr, JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING)) { return nullptr; } if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_Number, ctor, numberProto)) return nullptr; return numberProto; } static char* FracNumberToCString(ExclusiveContext* cx, ToCStringBuf* cbuf, double d, int base = 10) { #ifdef DEBUG { int32_t _; MOZ_ASSERT(!mozilla::NumberIsInt32(d, &_)); } #endif char* numStr; if (base == 10) { /* * 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, cbuf->sbufSize); converter.ToShortest(d, &builder); numStr = builder.Finalize(); } else { numStr = cbuf->dbuf = js_dtobasestr(cx->dtoaState(), base, d); } return numStr; } char* js::NumberToCString(JSContext* cx, ToCStringBuf* cbuf, double d, int base/* = 10*/) { int32_t i; size_t len; return mozilla::NumberIsInt32(d, &i) ? Int32ToCString(cbuf, i, &len, base) : FracNumberToCString(cx, cbuf, d, base); } template static JSString* NumberToStringWithBase(ExclusiveContext* cx, double d, int base) { ToCStringBuf cbuf; char* numStr; /* * Caller is responsible for error reporting. When called from trace, * returning nullptr here will cause us to fall of trace and then retry * from the interpreter (which will report the error). */ if (base < 2 || base > 36) return nullptr; JSCompartment* comp = cx->compartment(); int32_t i; if (mozilla::NumberIsInt32(d, &i)) { if (base == 10 && StaticStrings::hasInt(i)) return cx->staticStrings().getInt(i); 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); } if (JSFlatString* str = comp->dtoaCache.lookup(base, d)) return str; size_t len; numStr = Int32ToCString(&cbuf, i, &len, base); MOZ_ASSERT(!cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize); } else { if (JSFlatString* str = comp->dtoaCache.lookup(base, d)) return str; numStr = FracNumberToCString(cx, &cbuf, d, base); if (!numStr) { ReportOutOfMemory(cx); return nullptr; } MOZ_ASSERT_IF(base == 10, !cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize); MOZ_ASSERT_IF(base != 10, cbuf.dbuf && cbuf.dbuf == numStr); } JSFlatString* s = NewStringCopyZ(cx, numStr); comp->dtoaCache.cache(base, d, s); return s; } template JSString* js::NumberToString(ExclusiveContext* cx, double d) { return NumberToStringWithBase(cx, d, 10); } template JSString* js::NumberToString(ExclusiveContext* cx, double d); template JSString* js::NumberToString(ExclusiveContext* cx, double d); JSAtom* js::NumberToAtom(ExclusiveContext* cx, double d) { int32_t si; if (mozilla::NumberIsInt32(d, &si)) return Int32ToAtom(cx, si); if (JSFlatString* str = LookupDtoaCache(cx, d)) return AtomizeString(cx, str); ToCStringBuf cbuf; char* numStr = FracNumberToCString(cx, &cbuf, d); if (!numStr) { ReportOutOfMemory(cx); return nullptr; } MOZ_ASSERT(!cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize); size_t length = strlen(numStr); JSAtom* atom = Atomize(cx, numStr, length); if (!atom) return nullptr; CacheNumber(cx, d, atom); return atom; } JSFlatString* js::NumberToString(JSContext* cx, double d) { if (JSString* str = NumberToStringWithBase(cx, d, 10)) return &str->asFlat(); return nullptr; } JSFlatString* js::IndexToString(JSContext* cx, uint32_t index) { if (StaticStrings::hasUint(index)) return cx->staticStrings().getUint(index); JSCompartment* c = cx->compartment(); if (JSFlatString* str = c->dtoaCache.lookup(10, index)) return str; Latin1Char buffer[JSFatInlineString::MAX_LENGTH_LATIN1 + 1]; RangedPtr end(buffer + JSFatInlineString::MAX_LENGTH_LATIN1, buffer, JSFatInlineString::MAX_LENGTH_LATIN1 + 1); *end = '\0'; RangedPtr start = BackfillIndexInCharBuffer(index, end); mozilla::Range chars(start.get(), end - start); JSInlineString* str = NewInlineString(cx, chars); if (!str) return nullptr; c->dtoaCache.cache(10, index, str); return str; } bool JS_FASTCALL js::NumberValueToStringBuffer(JSContext* cx, const Value& v, StringBuffer& sb) { /* Convert to C-string. */ ToCStringBuf cbuf; const char* cstr; size_t cstrlen; if (v.isInt32()) { cstr = Int32ToCString(&cbuf, v.toInt32(), &cstrlen); MOZ_ASSERT(cstrlen == strlen(cstr)); } else { cstr = NumberToCString(cx, &cbuf, v.toDouble()); if (!cstr) { JS_ReportOutOfMemory(cx); return false; } cstrlen = strlen(cstr); } /* * Inflate to char16_t string. The input C-string characters are < 127, so * even if char16_t units are UTF-8, all chars should map to one char16_t. */ MOZ_ASSERT(!cbuf.dbuf && cstrlen < cbuf.sbufSize); return sb.append(cstr, cstrlen); } template static bool CharsToNumber(ExclusiveContext* cx, const CharT* chars, size_t length, double* result) { if (length == 1) { CharT c = chars[0]; if ('0' <= c && c <= '9') *result = c - '0'; else if (unicode::IsSpace(c)) *result = 0.0; else *result = GenericNaN(); return true; } const CharT* end = chars + length; const CharT* bp = SkipSpace(chars, end); /* ECMA doesn't allow signed non-decimal numbers (bug 273467). */ if (end - bp >= 2 && bp[0] == '0') { int radix = 0; if (bp[1] == 'b' || bp[1] == 'B') radix = 2; else if (bp[1] == 'o' || bp[1] == 'O') radix = 8; else if (bp[1] == 'x' || bp[1] == 'X') radix = 16; if (radix != 0) { /* * 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; if (!GetPrefixInteger(cx, bp + 2, end, radix, &endptr, &d) || endptr == bp + 2 || SkipSpace(endptr, end) != end) { *result = GenericNaN(); } else { *result = d; } return true; } } /* * 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; if (!js_strtod(cx, bp, end, &ep, &d)) { *result = GenericNaN(); return false; } if (SkipSpace(ep, end) != end) *result = GenericNaN(); else *result = d; return true; } bool js::StringToNumber(ExclusiveContext* cx, JSString* str, double* result) { AutoCheckCannotGC nogc; JSLinearString* linearStr = str->ensureLinear(cx); if (!linearStr) return false; return linearStr->hasLatin1Chars() ? CharsToNumber(cx, linearStr->latin1Chars(nogc), str->length(), result) : CharsToNumber(cx, linearStr->twoByteChars(nogc), str->length(), result); } bool js::ToNumberSlow(ExclusiveContext* cx, HandleValue v_, double* out) { RootedValue v(cx, v_); MOZ_ASSERT(!v.isNumber()); if (!v.isPrimitive()) { if (!cx->isJSContext()) return false; if (!ToPrimitive(cx->asJSContext(), 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.isSymbol()) { if (cx->isJSContext()) { JS_ReportErrorNumberASCII(cx->asJSContext(), GetErrorMessage, nullptr, JSMSG_SYMBOL_TO_NUMBER); } return false; } MOZ_ASSERT(v.isUndefined()); *out = GenericNaN(); return true; } JS_PUBLIC_API(bool) js::ToNumberSlow(JSContext* cx, HandleValue v, double* out) { return ToNumberSlow(static_cast(cx), v, out); } /* * 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 = ToInt8(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; } 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; } if (d == 0 || !mozilla::IsFinite(d)) { *out = 0; return true; } uint16_t u = (uint16_t) d; if ((double)u == d) { *out = u; return true; } bool neg = (d < 0); d = floor(neg ? -d : d); d = neg ? -d : d; unsigned m = JS_BIT(16); d = fmod(d, (double) m); if (d < 0) d += m; *out = (uint16_t) d; return true; } template bool js::ToLengthClamped(T* cx, HandleValue v, uint32_t* out, bool* overflow) { if (v.isInt32()) { int32_t i = v.toInt32(); *out = i < 0 ? 0 : i; return true; } double d; if (v.isDouble()) { d = v.toDouble(); } else { if (!ToNumber(cx, v, &d)) { *overflow = false; return false; } } d = JS::ToInteger(d); if (d <= 0.0) { *out = 0; return true; } if (d >= (double)0xFFFFFFFEU) { *overflow = true; return false; } *out = (uint32_t)d; return true; } template bool js::ToLengthClamped(JSContext*, HandleValue, uint32_t*, bool*); template bool js::ToLengthClamped(ExclusiveContext*, HandleValue, uint32_t*, bool*); bool js::ToIntegerIndex(JSContext* cx, JS::HandleValue v, uint64_t* index) { // Fast common case. if (v.isInt32()) { int32_t i = v.toInt32(); if (i >= 0) { *index = i; return true; } } // Slow case. Use ToNumber() to coerce. This may throw a TypeError. double d; if (!ToNumber(cx, v, &d)) return false; // Check that |d| is an integer in the valid range. // // Not all floating point integers fit in the range of a uint64_t, so we // need a rough range check before the real range check in our caller. We // could limit indexes to UINT64_MAX, but this would mean that our callers // have to be very careful about integer overflow. The contiguous integer // floating point numbers end at 2^53, so make that our upper limit. If we // ever support arrays with more than 2^53 elements, this will need to // change. // // Reject infinities, NaNs, and numbers outside the contiguous integer range // with a RangeError. // Write relation so NaNs throw a RangeError. if (!(0 <= d && d <= (uint64_t(1) << 53))) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_INDEX); return false; } // Check that d is an integer, throw a RangeError if not. // Note that this conversion could invoke undefined behaviour without the // range check above. uint64_t i(d); if (d != double(i)) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_INDEX); return false; } *index = i; return true; } template bool js_strtod(ExclusiveContext* cx, const CharT* begin, const CharT* end, const CharT** dEnd, double* d) { const CharT* s = SkipSpace(begin, end); size_t length = end - s; Vector chars(cx); if (!chars.growByUninitialized(length + 1)) return false; size_t i = 0; for (; i < length; i++) { char16_t c = s[i]; if (c >> 8) break; chars[i] = char(c); } chars[i] = 0; /* Try to parse +Infinity, -Infinity or Infinity. */ { char* afterSign = chars.begin(); bool negative = (*afterSign == '-'); if (negative || *afterSign == '+') afterSign++; if (*afterSign == 'I' && !strncmp(afterSign, "Infinity", 8)) { *d = negative ? NegativeInfinity() : PositiveInfinity(); *dEnd = s + (afterSign - chars.begin()) + 8; return true; } } /* Everything else. */ int err; char* ep; *d = js_strtod_harder(cx->dtoaState(), chars.begin(), &ep, &err); MOZ_ASSERT(ep >= chars.begin()); if (ep == chars.begin()) *dEnd = begin; else *dEnd = s + (ep - chars.begin()); return true; } template bool js_strtod(ExclusiveContext* cx, const char16_t* begin, const char16_t* end, const char16_t** dEnd, double* d); template bool js_strtod(ExclusiveContext* cx, const Latin1Char* begin, const Latin1Char* end, const Latin1Char** dEnd, double* d);