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comparison: js/src/jsnum.cpp

js/src/jsnum.cpp

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1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 * vim: set ts=8 sts=4 et sw=4 tw=99:
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 /*
8 * JS number type and wrapper class.
9 */
10
11 #include "jsnum.h"
12
13 #include "mozilla/FloatingPoint.h"
14 #include "mozilla/PodOperations.h"
15 #include "mozilla/RangedPtr.h"
16
17 #ifdef HAVE_LOCALECONV
18 #include <locale.h>
19 #endif
20 #include <math.h>
21 #include <string.h>
22
23 #include "double-conversion.h"
24 #include "jsatom.h"
25 #include "jscntxt.h"
26 #include "jsdtoa.h"
27 #include "jsobj.h"
28 #include "jsstr.h"
29 #include "jstypes.h"
30
31 #include "vm/GlobalObject.h"
32 #include "vm/NumericConversions.h"
33 #include "vm/StringBuffer.h"
34
35 #include "jsatominlines.h"
36
37 #include "vm/NumberObject-inl.h"
38 #include "vm/String-inl.h"
39
40 using namespace js;
41 using namespace js::types;
42
43 using mozilla::Abs;
44 using mozilla::MinNumberValue;
45 using mozilla::NegativeInfinity;
46 using mozilla::PodCopy;
47 using mozilla::PositiveInfinity;
48 using mozilla::RangedPtr;
49 using JS::GenericNaN;
50
51 /*
52 * If we're accumulating a decimal number and the number is >= 2^53, then the
53 * fast result from the loop in Get{Prefix,Decimal}Integer may be inaccurate.
54 * Call js_strtod_harder to get the correct answer.
55 */
56 static bool
57 ComputeAccurateDecimalInteger(ThreadSafeContext *cx,
58 const jschar *start, const jschar *end, double *dp)
59 {
60 size_t length = end - start;
61 char *cstr = cx->pod_malloc<char>(length + 1);
62 if (!cstr)
63 return false;
64
65 for (size_t i = 0; i < length; i++) {
66 char c = char(start[i]);
67 JS_ASSERT(('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'));
68 cstr[i] = c;
69 }
70 cstr[length] = 0;
71
72 char *estr;
73 int err = 0;
74 *dp = js_strtod_harder(cx->dtoaState(), cstr, &estr, &err);
75 if (err == JS_DTOA_ENOMEM) {
76 js_ReportOutOfMemory(cx);
77 js_free(cstr);
78 return false;
79 }
80 js_free(cstr);
81 return true;
82 }
83
84 namespace {
85
86 class BinaryDigitReader
87 {
88 const int base; /* Base of number; must be a power of 2 */
89 int digit; /* Current digit value in radix given by base */
90 int digitMask; /* Mask to extract the next bit from digit */
91 const jschar *start; /* Pointer to the remaining digits */
92 const jschar *end; /* Pointer to first non-digit */
93
94 public:
95 BinaryDigitReader(int base, const jschar *start, const jschar *end)
96 : base(base), digit(0), digitMask(0), start(start), end(end)
97 {
98 }
99
100 /* Return the next binary digit from the number, or -1 if done. */
101 int nextDigit() {
102 if (digitMask == 0) {
103 if (start == end)
104 return -1;
105
106 int c = *start++;
107 JS_ASSERT(('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'));
108 if ('0' <= c && c <= '9')
109 digit = c - '0';
110 else if ('a' <= c && c <= 'z')
111 digit = c - 'a' + 10;
112 else
113 digit = c - 'A' + 10;
114 digitMask = base >> 1;
115 }
116
117 int bit = (digit & digitMask) != 0;
118 digitMask >>= 1;
119 return bit;
120 }
121 };
122
123 } /* anonymous namespace */
124
125 /*
126 * The fast result might also have been inaccurate for power-of-two bases. This
127 * happens if the addition in value * 2 + digit causes a round-down to an even
128 * least significant mantissa bit when the first dropped bit is a one. If any
129 * of the following digits in the number (which haven't been added in yet) are
130 * nonzero, then the correct action would have been to round up instead of
131 * down. An example occurs when reading the number 0x1000000000000081, which
132 * rounds to 0x1000000000000000 instead of 0x1000000000000100.
133 */
134 static double
135 ComputeAccurateBinaryBaseInteger(const jschar *start, const jschar *end, int base)
136 {
137 BinaryDigitReader bdr(base, start, end);
138
139 /* Skip leading zeroes. */
140 int bit;
141 do {
142 bit = bdr.nextDigit();
143 } while (bit == 0);
144
145 JS_ASSERT(bit == 1); // guaranteed by Get{Prefix,Decimal}Integer
146
147 /* Gather the 53 significant bits (including the leading 1). */
148 double value = 1.0;
149 for (int j = 52; j > 0; j--) {
150 bit = bdr.nextDigit();
151 if (bit < 0)
152 return value;
153 value = value * 2 + bit;
154 }
155
156 /* bit2 is the 54th bit (the first dropped from the mantissa). */
157 int bit2 = bdr.nextDigit();
158 if (bit2 >= 0) {
159 double factor = 2.0;
160 int sticky = 0; /* sticky is 1 if any bit beyond the 54th is 1 */
161 int bit3;
162
163 while ((bit3 = bdr.nextDigit()) >= 0) {
164 sticky |= bit3;
165 factor *= 2;
166 }
167 value += bit2 & (bit | sticky);
168 value *= factor;
169 }
170
171 return value;
172 }
173
174 double
175 js::ParseDecimalNumber(const JS::TwoByteChars chars)
176 {
177 MOZ_ASSERT(chars.length() > 0);
178 uint64_t dec = 0;
179 RangedPtr<jschar> s = chars.start(), end = chars.end();
180 do {
181 jschar c = *s;
182 MOZ_ASSERT('0' <= c && c <= '9');
183 uint8_t digit = c - '0';
184 uint64_t next = dec * 10 + digit;
185 MOZ_ASSERT(next < DOUBLE_INTEGRAL_PRECISION_LIMIT,
186 "next value won't be an integrally-precise double");
187 dec = next;
188 } while (++s < end);
189 return static_cast<double>(dec);
190 }
191
192 bool
193 js::GetPrefixInteger(ThreadSafeContext *cx, const jschar *start, const jschar *end, int base,
194 const jschar **endp, double *dp)
195 {
196 JS_ASSERT(start <= end);
197 JS_ASSERT(2 <= base && base <= 36);
198
199 const jschar *s = start;
200 double d = 0.0;
201 for (; s < end; s++) {
202 int digit;
203 jschar c = *s;
204 if ('0' <= c && c <= '9')
205 digit = c - '0';
206 else if ('a' <= c && c <= 'z')
207 digit = c - 'a' + 10;
208 else if ('A' <= c && c <= 'Z')
209 digit = c - 'A' + 10;
210 else
211 break;
212 if (digit >= base)
213 break;
214 d = d * base + digit;
215 }
216
217 *endp = s;
218 *dp = d;
219
220 /* If we haven't reached the limit of integer precision, we're done. */
221 if (d < DOUBLE_INTEGRAL_PRECISION_LIMIT)
222 return true;
223
224 /*
225 * Otherwise compute the correct integer from the prefix of valid digits
226 * if we're computing for base ten or a power of two. Don't worry about
227 * other bases; see 15.1.2.2 step 13.
228 */
229 if (base == 10)
230 return ComputeAccurateDecimalInteger(cx, start, s, dp);
231 if ((base & (base - 1)) == 0)
232 *dp = ComputeAccurateBinaryBaseInteger(start, s, base);
233
234 return true;
235 }
236
237 bool
238 js::GetDecimalInteger(ExclusiveContext *cx, const jschar *start, const jschar *end, double *dp)
239 {
240 JS_ASSERT(start <= end);
241
242 const jschar *s = start;
243 double d = 0.0;
244 for (; s < end; s++) {
245 jschar c = *s;
246 JS_ASSERT('0' <= c && c <= '9');
247 int digit = c - '0';
248 d = d * 10 + digit;
249 }
250
251 *dp = d;
252
253 // If we haven't reached the limit of integer precision, we're done.
254 if (d < DOUBLE_INTEGRAL_PRECISION_LIMIT)
255 return true;
256
257 // Otherwise compute the correct integer from the prefix of valid digits.
258 return ComputeAccurateDecimalInteger(cx, start, s, dp);
259 }
260
261 static bool
262 num_isNaN(JSContext *cx, unsigned argc, Value *vp)
263 {
264 CallArgs args = CallArgsFromVp(argc, vp);
265
266 if (args.length() == 0) {
267 args.rval().setBoolean(true);
268 return true;
269 }
270
271 double x;
272 if (!ToNumber(cx, args[0], &x))
273 return false;
274
275 args.rval().setBoolean(mozilla::IsNaN(x));
276 return true;
277 }
278
279 static bool
280 num_isFinite(JSContext *cx, unsigned argc, Value *vp)
281 {
282 CallArgs args = CallArgsFromVp(argc, vp);
283
284 if (args.length() == 0) {
285 args.rval().setBoolean(false);
286 return true;
287 }
288
289 double x;
290 if (!ToNumber(cx, args[0], &x))
291 return false;
292
293 args.rval().setBoolean(mozilla::IsFinite(x));
294 return true;
295 }
296
297 static bool
298 num_parseFloat(JSContext *cx, unsigned argc, Value *vp)
299 {
300 CallArgs args = CallArgsFromVp(argc, vp);
301
302 if (args.length() == 0) {
303 args.rval().setNaN();
304 return true;
305 }
306 JSString *str = ToString<CanGC>(cx, args[0]);
307 if (!str)
308 return false;
309 const jschar *bp = str->getChars(cx);
310 if (!bp)
311 return false;
312 const jschar *end = bp + str->length();
313 const jschar *ep;
314 double d;
315 if (!js_strtod(cx, bp, end, &ep, &d))
316 return false;
317 if (ep == bp) {
318 args.rval().setNaN();
319 return true;
320 }
321 args.rval().setDouble(d);
322 return true;
323 }
324
325 /* ES5 15.1.2.2. */
326 bool
327 js::num_parseInt(JSContext *cx, unsigned argc, Value *vp)
328 {
329 CallArgs args = CallArgsFromVp(argc, vp);
330
331 /* Fast paths and exceptional cases. */
332 if (args.length() == 0) {
333 args.rval().setNaN();
334 return true;
335 }
336
337 if (args.length() == 1 ||
338 (args[1].isInt32() && (args[1].toInt32() == 0 || args[1].toInt32() == 10))) {
339 if (args[0].isInt32()) {
340 args.rval().set(args[0]);
341 return true;
342 }
343
344 /*
345 * Step 1 is |inputString = ToString(string)|. When string >=
346 * 1e21, ToString(string) is in the form "NeM". 'e' marks the end of
347 * the word, which would mean the result of parseInt(string) should be |N|.
348 *
349 * To preserve this behaviour, we can't use the fast-path when string >
350 * 1e21, or else the result would be |NeM|.
351 *
352 * The same goes for values smaller than 1.0e-6, because the string would be in
353 * the form of "Ne-M".
354 */
355 if (args[0].isDouble()) {
356 double d = args[0].toDouble();
357 if (1.0e-6 < d && d < 1.0e21) {
358 args.rval().setNumber(floor(d));
359 return true;
360 }
361 if (-1.0e21 < d && d < -1.0e-6) {
362 args.rval().setNumber(-floor(-d));
363 return true;
364 }
365 if (d == 0.0) {
366 args.rval().setInt32(0);
367 return true;
368 }
369 }
370 }
371
372 /* Step 1. */
373 RootedString inputString(cx, ToString<CanGC>(cx, args[0]));
374 if (!inputString)
375 return false;
376 args[0].setString(inputString);
377
378 /* Steps 6-9. */
379 bool stripPrefix = true;
380 int32_t radix;
381 if (!args.hasDefined(1)) {
382 radix = 10;
383 } else {
384 if (!ToInt32(cx, args[1], &radix))
385 return false;
386 if (radix == 0) {
387 radix = 10;
388 } else {
389 if (radix < 2 || radix > 36) {
390 args.rval().setNaN();
391 return true;
392 }
393 if (radix != 16)
394 stripPrefix = false;
395 }
396 }
397
398 /* Step 2. */
399 const jschar *s;
400 const jschar *end;
401 {
402 const jschar *ws = inputString->getChars(cx);
403 if (!ws)
404 return false;
405 end = ws + inputString->length();
406 s = SkipSpace(ws, end);
407
408 MOZ_ASSERT(ws <= s);
409 MOZ_ASSERT(s <= end);
410 }
411
412 /* Steps 3-4. */
413 bool negative = (s != end && s[0] == '-');
414
415 /* Step 5. */
416 if (s != end && (s[0] == '-' || s[0] == '+'))
417 s++;
418
419 /* Step 10. */
420 if (stripPrefix) {
421 if (end - s >= 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) {
422 s += 2;
423 radix = 16;
424 }
425 }
426
427 /* Steps 11-15. */
428 const jschar *actualEnd;
429 double number;
430 if (!GetPrefixInteger(cx, s, end, radix, &actualEnd, &number))
431 return false;
432 if (s == actualEnd)
433 args.rval().setNaN();
434 else
435 args.rval().setNumber(negative ? -number : number);
436 return true;
437 }
438
439 static const JSFunctionSpec number_functions[] = {
440 JS_FN(js_isNaN_str, num_isNaN, 1,0),
441 JS_FN(js_isFinite_str, num_isFinite, 1,0),
442 JS_FN(js_parseFloat_str, num_parseFloat, 1,0),
443 JS_FN(js_parseInt_str, num_parseInt, 2,0),
444 JS_FS_END
445 };
446
447 const Class NumberObject::class_ = {
448 js_Number_str,
449 JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_HAS_CACHED_PROTO(JSProto_Number),
450 JS_PropertyStub, /* addProperty */
451 JS_DeletePropertyStub, /* delProperty */
452 JS_PropertyStub, /* getProperty */
453 JS_StrictPropertyStub, /* setProperty */
454 JS_EnumerateStub,
455 JS_ResolveStub,
456 JS_ConvertStub
457 };
458
459 static bool
460 Number(JSContext *cx, unsigned argc, Value *vp)
461 {
462 CallArgs args = CallArgsFromVp(argc, vp);
463
464 /* Sample JS_CALLEE before clobbering. */
465 bool isConstructing = args.isConstructing();
466
467 if (args.length() > 0) {
468 if (!ToNumber(cx, args[0]))
469 return false;
470 args.rval().set(args[0]);
471 } else {
472 args.rval().setInt32(0);
473 }
474
475 if (!isConstructing)
476 return true;
477
478 JSObject *obj = NumberObject::create(cx, args.rval().toNumber());
479 if (!obj)
480 return false;
481 args.rval().setObject(*obj);
482 return true;
483 }
484
485 MOZ_ALWAYS_INLINE bool
486 IsNumber(HandleValue v)
487 {
488 return v.isNumber() || (v.isObject() && v.toObject().is<NumberObject>());
489 }
490
491 static inline double
492 Extract(const Value &v)
493 {
494 if (v.isNumber())
495 return v.toNumber();
496 return v.toObject().as<NumberObject>().unbox();
497 }
498
499 #if JS_HAS_TOSOURCE
500 MOZ_ALWAYS_INLINE bool
501 num_toSource_impl(JSContext *cx, CallArgs args)
502 {
503 double d = Extract(args.thisv());
504
505 StringBuffer sb(cx);
506 if (!sb.append("(new Number(") ||
507 !NumberValueToStringBuffer(cx, NumberValue(d), sb) ||
508 !sb.append("))"))
509 {
510 return false;
511 }
512
513 JSString *str = sb.finishString();
514 if (!str)
515 return false;
516 args.rval().setString(str);
517 return true;
518 }
519
520 static bool
521 num_toSource(JSContext *cx, unsigned argc, Value *vp)
522 {
523 CallArgs args = CallArgsFromVp(argc, vp);
524 return CallNonGenericMethod<IsNumber, num_toSource_impl>(cx, args);
525 }
526 #endif
527
528 ToCStringBuf::ToCStringBuf() :dbuf(nullptr)
529 {
530 JS_STATIC_ASSERT(sbufSize >= DTOSTR_STANDARD_BUFFER_SIZE);
531 }
532
533 ToCStringBuf::~ToCStringBuf()
534 {
535 js_free(dbuf);
536 }
537
538 MOZ_ALWAYS_INLINE
539 static JSFlatString *
540 LookupDtoaCache(ThreadSafeContext *cx, double d)
541 {
542 if (!cx->isExclusiveContext())
543 return nullptr;
544
545 if (JSCompartment *comp = cx->asExclusiveContext()->compartment()) {
546 if (JSFlatString *str = comp->dtoaCache.lookup(10, d))
547 return str;
548 }
549
550 return nullptr;
551 }
552
553 MOZ_ALWAYS_INLINE
554 static void
555 CacheNumber(ThreadSafeContext *cx, double d, JSFlatString *str)
556 {
557 if (!cx->isExclusiveContext())
558 return;
559
560 if (JSCompartment *comp = cx->asExclusiveContext()->compartment())
561 comp->dtoaCache.cache(10, d, str);
562 }
563
564 MOZ_ALWAYS_INLINE
565 static JSFlatString *
566 LookupInt32ToString(ThreadSafeContext *cx, int32_t si)
567 {
568 if (si >= 0 && StaticStrings::hasInt(si))
569 return cx->staticStrings().getInt(si);
570
571 return LookupDtoaCache(cx, si);
572 }
573
574 template <typename T>
575 MOZ_ALWAYS_INLINE
576 static T *
577 BackfillInt32InBuffer(int32_t si, T *buffer, size_t size, size_t *length)
578 {
579 uint32_t ui = Abs(si);
580 JS_ASSERT_IF(si == INT32_MIN, ui == uint32_t(INT32_MAX) + 1);
581
582 RangedPtr<T> end(buffer + size - 1, buffer, size);
583 *end = '\0';
584 RangedPtr<T> start = BackfillIndexInCharBuffer(ui, end);
585 if (si < 0)
586 *--start = '-';
587
588 *length = end - start;
589 return start.get();
590 }
591
592 template <AllowGC allowGC>
593 JSFlatString *
594 js::Int32ToString(ThreadSafeContext *cx, int32_t si)
595 {
596 if (JSFlatString *str = LookupInt32ToString(cx, si))
597 return str;
598
599 JSFatInlineString *str = js_NewGCFatInlineString<allowGC>(cx);
600 if (!str)
601 return nullptr;
602
603 jschar buffer[JSFatInlineString::MAX_FAT_INLINE_LENGTH + 1];
604 size_t length;
605 jschar *start = BackfillInt32InBuffer(si, buffer,
606 JSFatInlineString::MAX_FAT_INLINE_LENGTH + 1, &length);
607
608 PodCopy(str->init(length), start, length + 1);
609
610 CacheNumber(cx, si, str);
611 return str;
612 }
613
614 template JSFlatString *
615 js::Int32ToString<CanGC>(ThreadSafeContext *cx, int32_t si);
616
617 template JSFlatString *
618 js::Int32ToString<NoGC>(ThreadSafeContext *cx, int32_t si);
619
620 JSAtom *
621 js::Int32ToAtom(ExclusiveContext *cx, int32_t si)
622 {
623 if (JSFlatString *str = LookupInt32ToString(cx, si))
624 return js::AtomizeString(cx, str);
625
626 char buffer[JSFatInlineString::MAX_FAT_INLINE_LENGTH + 1];
627 size_t length;
628 char *start = BackfillInt32InBuffer(si, buffer, JSFatInlineString::MAX_FAT_INLINE_LENGTH + 1, &length);
629
630 JSAtom *atom = Atomize(cx, start, length);
631 if (!atom)
632 return nullptr;
633
634 CacheNumber(cx, si, atom);
635 return atom;
636 }
637
638 /* Returns a non-nullptr pointer to inside cbuf. */
639 static char *
640 Int32ToCString(ToCStringBuf *cbuf, int32_t i, size_t *len, int base = 10)
641 {
642 uint32_t u = Abs(i);
643
644 RangedPtr<char> cp(cbuf->sbuf + ToCStringBuf::sbufSize - 1, cbuf->sbuf, ToCStringBuf::sbufSize);
645 char *end = cp.get();
646 *cp = '\0';
647
648 /* Build the string from behind. */
649 switch (base) {
650 case 10:
651 cp = BackfillIndexInCharBuffer(u, cp);
652 break;
653 case 16:
654 do {
655 unsigned newu = u / 16;
656 *--cp = "0123456789abcdef"[u - newu * 16];
657 u = newu;
658 } while (u != 0);
659 break;
660 default:
661 JS_ASSERT(base >= 2 && base <= 36);
662 do {
663 unsigned newu = u / base;
664 *--cp = "0123456789abcdefghijklmnopqrstuvwxyz"[u - newu * base];
665 u = newu;
666 } while (u != 0);
667 break;
668 }
669 if (i < 0)
670 *--cp = '-';
671
672 *len = end - cp.get();
673 return cp.get();
674 }
675
676 template <AllowGC allowGC>
677 static JSString * JS_FASTCALL
678 js_NumberToStringWithBase(ThreadSafeContext *cx, double d, int base);
679
680 MOZ_ALWAYS_INLINE bool
681 num_toString_impl(JSContext *cx, CallArgs args)
682 {
683 JS_ASSERT(IsNumber(args.thisv()));
684
685 double d = Extract(args.thisv());
686
687 int32_t base = 10;
688 if (args.hasDefined(0)) {
689 double d2;
690 if (!ToInteger(cx, args[0], &d2))
691 return false;
692
693 if (d2 < 2 || d2 > 36) {
694 JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_BAD_RADIX);
695 return false;
696 }
697
698 base = int32_t(d2);
699 }
700 JSString *str = js_NumberToStringWithBase<CanGC>(cx, d, base);
701 if (!str) {
702 JS_ReportOutOfMemory(cx);
703 return false;
704 }
705 args.rval().setString(str);
706 return true;
707 }
708
709 bool
710 js_num_toString(JSContext *cx, unsigned argc, Value *vp)
711 {
712 CallArgs args = CallArgsFromVp(argc, vp);
713 return CallNonGenericMethod<IsNumber, num_toString_impl>(cx, args);
714 }
715
716 #if !EXPOSE_INTL_API
717 MOZ_ALWAYS_INLINE bool
718 num_toLocaleString_impl(JSContext *cx, CallArgs args)
719 {
720 JS_ASSERT(IsNumber(args.thisv()));
721
722 double d = Extract(args.thisv());
723
724 Rooted<JSString*> str(cx, js_NumberToStringWithBase<CanGC>(cx, d, 10));
725 if (!str) {
726 JS_ReportOutOfMemory(cx);
727 return false;
728 }
729
730 /*
731 * Create the string, move back to bytes to make string twiddling
732 * a bit easier and so we can insert platform charset seperators.
733 */
734 JSAutoByteString numBytes(cx, str);
735 if (!numBytes)
736 return false;
737 const char *num = numBytes.ptr();
738 if (!num)
739 return false;
740
741 /*
742 * Find the first non-integer value, whether it be a letter as in
743 * 'Infinity', a decimal point, or an 'e' from exponential notation.
744 */
745 const char *nint = num;
746 if (*nint == '-')
747 nint++;
748 while (*nint >= '0' && *nint <= '9')
749 nint++;
750 int digits = nint - num;
751 const char *end = num + digits;
752 if (!digits) {
753 args.rval().setString(str);
754 return true;
755 }
756
757 JSRuntime *rt = cx->runtime();
758 size_t thousandsLength = strlen(rt->thousandsSeparator);
759 size_t decimalLength = strlen(rt->decimalSeparator);
760
761 /* Figure out how long resulting string will be. */
762 int buflen = strlen(num);
763 if (*nint == '.')
764 buflen += decimalLength - 1; /* -1 to account for existing '.' */
765
766 const char *numGrouping;
767 const char *tmpGroup;
768 numGrouping = tmpGroup = rt->numGrouping;
769 int remainder = digits;
770 if (*num == '-')
771 remainder--;
772
773 while (*tmpGroup != CHAR_MAX && *tmpGroup != '\0') {
774 if (*tmpGroup >= remainder)
775 break;
776 buflen += thousandsLength;
777 remainder -= *tmpGroup;
778 tmpGroup++;
779 }
780
781 int nrepeat;
782 if (*tmpGroup == '\0' && *numGrouping != '\0') {
783 nrepeat = (remainder - 1) / tmpGroup[-1];
784 buflen += thousandsLength * nrepeat;
785 remainder -= nrepeat * tmpGroup[-1];
786 } else {
787 nrepeat = 0;
788 }
789 tmpGroup--;
790
791 char *buf = cx->pod_malloc<char>(buflen + 1);
792 if (!buf)
793 return false;
794
795 char *tmpDest = buf;
796 const char *tmpSrc = num;
797
798 while (*tmpSrc == '-' || remainder--) {
799 JS_ASSERT(tmpDest - buf < buflen);
800 *tmpDest++ = *tmpSrc++;
801 }
802 while (tmpSrc < end) {
803 JS_ASSERT(tmpDest - buf + ptrdiff_t(thousandsLength) <= buflen);
804 strcpy(tmpDest, rt->thousandsSeparator);
805 tmpDest += thousandsLength;
806 JS_ASSERT(tmpDest - buf + *tmpGroup <= buflen);
807 js_memcpy(tmpDest, tmpSrc, *tmpGroup);
808 tmpDest += *tmpGroup;
809 tmpSrc += *tmpGroup;
810 if (--nrepeat < 0)
811 tmpGroup--;
812 }
813
814 if (*nint == '.') {
815 JS_ASSERT(tmpDest - buf + ptrdiff_t(decimalLength) <= buflen);
816 strcpy(tmpDest, rt->decimalSeparator);
817 tmpDest += decimalLength;
818 JS_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint + 1)) <= buflen);
819 strcpy(tmpDest, nint + 1);
820 } else {
821 JS_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint)) <= buflen);
822 strcpy(tmpDest, nint);
823 }
824
825 if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeToUnicode) {
826 Rooted<Value> v(cx, StringValue(str));
827 bool ok = !!cx->runtime()->localeCallbacks->localeToUnicode(cx, buf, &v);
828 if (ok)
829 args.rval().set(v);
830 js_free(buf);
831 return ok;
832 }
833
834 str = js_NewStringCopyN<CanGC>(cx, buf, buflen);
835 js_free(buf);
836 if (!str)
837 return false;
838
839 args.rval().setString(str);
840 return true;
841 }
842
843 static bool
844 num_toLocaleString(JSContext *cx, unsigned argc, Value *vp)
845 {
846 CallArgs args = CallArgsFromVp(argc, vp);
847 return CallNonGenericMethod<IsNumber, num_toLocaleString_impl>(cx, args);
848 }
849 #endif /* !EXPOSE_INTL_API */
850
851 MOZ_ALWAYS_INLINE bool
852 num_valueOf_impl(JSContext *cx, CallArgs args)
853 {
854 JS_ASSERT(IsNumber(args.thisv()));
855 args.rval().setNumber(Extract(args.thisv()));
856 return true;
857 }
858
859 bool
860 js_num_valueOf(JSContext *cx, unsigned argc, Value *vp)
861 {
862 CallArgs args = CallArgsFromVp(argc, vp);
863 return CallNonGenericMethod<IsNumber, num_valueOf_impl>(cx, args);
864 }
865
866 static const unsigned MAX_PRECISION = 100;
867
868 static bool
869 ComputePrecisionInRange(JSContext *cx, int minPrecision, int maxPrecision, HandleValue v,
870 int *precision)
871 {
872 double prec;
873 if (!ToInteger(cx, v, &prec))
874 return false;
875 if (minPrecision <= prec && prec <= maxPrecision) {
876 *precision = int(prec);
877 return true;
878 }
879
880 ToCStringBuf cbuf;
881 if (char *numStr = NumberToCString(cx, &cbuf, prec, 10))
882 JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_PRECISION_RANGE, numStr);
883 return false;
884 }
885
886 static bool
887 DToStrResult(JSContext *cx, double d, JSDToStrMode mode, int precision, CallArgs args)
888 {
889 char buf[DTOSTR_VARIABLE_BUFFER_SIZE(MAX_PRECISION + 1)];
890 char *numStr = js_dtostr(cx->mainThread().dtoaState, buf, sizeof buf, mode, precision, d);
891 if (!numStr) {
892 JS_ReportOutOfMemory(cx);
893 return false;
894 }
895 JSString *str = js_NewStringCopyZ<CanGC>(cx, numStr);
896 if (!str)
897 return false;
898 args.rval().setString(str);
899 return true;
900 }
901
902 /*
903 * In the following three implementations, we allow a larger range of precision
904 * than ECMA requires; this is permitted by ECMA-262.
905 */
906 MOZ_ALWAYS_INLINE bool
907 num_toFixed_impl(JSContext *cx, CallArgs args)
908 {
909 JS_ASSERT(IsNumber(args.thisv()));
910
911 int precision;
912 if (args.length() == 0) {
913 precision = 0;
914 } else {
915 if (!ComputePrecisionInRange(cx, -20, MAX_PRECISION, args[0], &precision))
916 return false;
917 }
918
919 return DToStrResult(cx, Extract(args.thisv()), DTOSTR_FIXED, precision, args);
920 }
921
922 static bool
923 num_toFixed(JSContext *cx, unsigned argc, Value *vp)
924 {
925 CallArgs args = CallArgsFromVp(argc, vp);
926 return CallNonGenericMethod<IsNumber, num_toFixed_impl>(cx, args);
927 }
928
929 MOZ_ALWAYS_INLINE bool
930 num_toExponential_impl(JSContext *cx, CallArgs args)
931 {
932 JS_ASSERT(IsNumber(args.thisv()));
933
934 JSDToStrMode mode;
935 int precision;
936 if (!args.hasDefined(0)) {
937 mode = DTOSTR_STANDARD_EXPONENTIAL;
938 precision = 0;
939 } else {
940 mode = DTOSTR_EXPONENTIAL;
941 if (!ComputePrecisionInRange(cx, 0, MAX_PRECISION, args[0], &precision))
942 return false;
943 }
944
945 return DToStrResult(cx, Extract(args.thisv()), mode, precision + 1, args);
946 }
947
948 static bool
949 num_toExponential(JSContext *cx, unsigned argc, Value *vp)
950 {
951 CallArgs args = CallArgsFromVp(argc, vp);
952 return CallNonGenericMethod<IsNumber, num_toExponential_impl>(cx, args);
953 }
954
955 MOZ_ALWAYS_INLINE bool
956 num_toPrecision_impl(JSContext *cx, CallArgs args)
957 {
958 JS_ASSERT(IsNumber(args.thisv()));
959
960 double d = Extract(args.thisv());
961
962 if (!args.hasDefined(0)) {
963 JSString *str = js_NumberToStringWithBase<CanGC>(cx, d, 10);
964 if (!str) {
965 JS_ReportOutOfMemory(cx);
966 return false;
967 }
968 args.rval().setString(str);
969 return true;
970 }
971
972 int precision;
973 if (!ComputePrecisionInRange(cx, 1, MAX_PRECISION, args[0], &precision))
974 return false;
975
976 return DToStrResult(cx, d, DTOSTR_PRECISION, precision, args);
977 }
978
979 static bool
980 num_toPrecision(JSContext *cx, unsigned argc, Value *vp)
981 {
982 CallArgs args = CallArgsFromVp(argc, vp);
983 return CallNonGenericMethod<IsNumber, num_toPrecision_impl>(cx, args);
984 }
985
986 static const JSFunctionSpec number_methods[] = {
987 #if JS_HAS_TOSOURCE
988 JS_FN(js_toSource_str, num_toSource, 0, 0),
989 #endif
990 JS_FN(js_toString_str, js_num_toString, 1, 0),
991 #if EXPOSE_INTL_API
992 JS_SELF_HOSTED_FN(js_toLocaleString_str, "Number_toLocaleString", 0,0),
993 #else
994 JS_FN(js_toLocaleString_str, num_toLocaleString, 0,0),
995 #endif
996 JS_FN(js_valueOf_str, js_num_valueOf, 0, 0),
997 JS_FN("toFixed", num_toFixed, 1, 0),
998 JS_FN("toExponential", num_toExponential, 1, 0),
999 JS_FN("toPrecision", num_toPrecision, 1, 0),
1000 JS_FS_END
1001 };
1002
1003
1004 // ES6 draft ES6 15.7.3.10
1005 static bool
1006 Number_isNaN(JSContext *cx, unsigned argc, Value *vp)
1007 {
1008 CallArgs args = CallArgsFromVp(argc, vp);
1009 if (args.length() < 1 || !args[0].isDouble()) {
1010 args.rval().setBoolean(false);
1011 return true;
1012 }
1013 args.rval().setBoolean(mozilla::IsNaN(args[0].toDouble()));
1014 return true;
1015 }
1016
1017 // ES6 draft ES6 15.7.3.11
1018 static bool
1019 Number_isFinite(JSContext *cx, unsigned argc, Value *vp)
1020 {
1021 CallArgs args = CallArgsFromVp(argc, vp);
1022 if (args.length() < 1 || !args[0].isNumber()) {
1023 args.rval().setBoolean(false);
1024 return true;
1025 }
1026 args.rval().setBoolean(args[0].isInt32() ||
1027 mozilla::IsFinite(args[0].toDouble()));
1028 return true;
1029 }
1030
1031 // ES6 draft ES6 15.7.3.12
1032 static bool
1033 Number_isInteger(JSContext *cx, unsigned argc, Value *vp)
1034 {
1035 CallArgs args = CallArgsFromVp(argc, vp);
1036 if (args.length() < 1 || !args[0].isNumber()) {
1037 args.rval().setBoolean(false);
1038 return true;
1039 }
1040 Value val = args[0];
1041 args.rval().setBoolean(val.isInt32() ||
1042 (mozilla::IsFinite(val.toDouble()) &&
1043 ToInteger(val.toDouble()) == val.toDouble()));
1044 return true;
1045 }
1046
1047 // ES6 drafult ES6 15.7.3.13
1048 static bool
1049 Number_toInteger(JSContext *cx, unsigned argc, Value *vp)
1050 {
1051 CallArgs args = CallArgsFromVp(argc, vp);
1052 if (args.length() < 1) {
1053 args.rval().setInt32(0);
1054 return true;
1055 }
1056 double asint;
1057 if (!ToInteger(cx, args[0], &asint))
1058 return false;
1059 args.rval().setNumber(asint);
1060 return true;
1061 }
1062
1063
1064 static const JSFunctionSpec number_static_methods[] = {
1065 JS_FN("isFinite", Number_isFinite, 1, 0),
1066 JS_FN("isInteger", Number_isInteger, 1, 0),
1067 JS_FN("isNaN", Number_isNaN, 1, 0),
1068 JS_FN("toInteger", Number_toInteger, 1, 0),
1069 /* ES6 additions. */
1070 JS_FN("parseFloat", num_parseFloat, 1, 0),
1071 JS_FN("parseInt", num_parseInt, 2, 0),
1072 JS_FS_END
1073 };
1074
1075
1076 /* NB: Keep this in synch with number_constants[]. */
1077 enum nc_slot {
1078 NC_NaN,
1079 NC_POSITIVE_INFINITY,
1080 NC_NEGATIVE_INFINITY,
1081 NC_MAX_VALUE,
1082 NC_MIN_VALUE,
1083 NC_MAX_SAFE_INTEGER,
1084 NC_MIN_SAFE_INTEGER,
1085 NC_EPSILON,
1086 NC_LIMIT
1087 };
1088
1089 /*
1090 * Some to most C compilers forbid spelling these at compile time, or barf
1091 * if you try, so all but MAX_VALUE are set up by InitRuntimeNumberState
1092 * using union jsdpun.
1093 */
1094 static JSConstDoubleSpec number_constants[] = {
1095 {0, "NaN", 0,{0,0,0}},
1096 {0, "POSITIVE_INFINITY", 0,{0,0,0}},
1097 {0, "NEGATIVE_INFINITY", 0,{0,0,0}},
1098 {1.7976931348623157E+308, "MAX_VALUE", 0,{0,0,0}},
1099 {0, "MIN_VALUE", 0,{0,0,0}},
1100 /* ES6 (April 2014 draft) 20.1.2.6 */
1101 {9007199254740991, "MAX_SAFE_INTEGER", 0,{0,0,0}},
1102 /* ES6 (April 2014 draft) 20.1.2.10 */
1103 {-9007199254740991, "MIN_SAFE_INTEGER", 0,{0,0,0}},
1104 /* ES6 (May 2013 draft) 15.7.3.7 */
1105 {2.2204460492503130808472633361816e-16, "EPSILON", 0,{0,0,0}},
1106 {0,0,0,{0,0,0}}
1107 };
1108
1109 #if (defined __GNUC__ && defined __i386__) || \
1110 (defined __SUNPRO_CC && defined __i386)
1111
1112 /*
1113 * Set the exception mask to mask all exceptions and set the FPU precision
1114 * to 53 bit mantissa (64 bit doubles).
1115 */
1116 static inline void FIX_FPU() {
1117 short control;
1118 asm("fstcw %0" : "=m" (control) : );
1119 control &= ~0x300; // Lower bits 8 and 9 (precision control).
1120 control |= 0x2f3; // Raise bits 0-5 (exception masks) and 9 (64-bit precision).
1121 asm("fldcw %0" : : "m" (control) );
1122 }
1123
1124 #else
1125
1126 #define FIX_FPU() ((void)0)
1127
1128 #endif
1129
1130 bool
1131 js::InitRuntimeNumberState(JSRuntime *rt)
1132 {
1133 FIX_FPU();
1134
1135 /*
1136 * Our NaN must be one particular canonical value, because we rely on NaN
1137 * encoding for our value representation. See Value.h.
1138 */
1139 number_constants[NC_NaN].dval = GenericNaN();
1140
1141 number_constants[NC_POSITIVE_INFINITY].dval = mozilla::PositiveInfinity<double>();
1142 number_constants[NC_NEGATIVE_INFINITY].dval = mozilla::NegativeInfinity<double>();
1143
1144 number_constants[NC_MIN_VALUE].dval = MinNumberValue<double>();
1145
1146 // XXX If EXPOSE_INTL_API becomes true all the time at some point,
1147 // js::InitRuntimeNumberState is no longer fallible, and we should
1148 // change its return type.
1149 #if !EXPOSE_INTL_API
1150 /* Copy locale-specific separators into the runtime strings. */
1151 const char *thousandsSeparator, *decimalPoint, *grouping;
1152 #ifdef HAVE_LOCALECONV
1153 struct lconv *locale = localeconv();
1154 thousandsSeparator = locale->thousands_sep;
1155 decimalPoint = locale->decimal_point;
1156 grouping = locale->grouping;
1157 #else
1158 thousandsSeparator = getenv("LOCALE_THOUSANDS_SEP");
1159 decimalPoint = getenv("LOCALE_DECIMAL_POINT");
1160 grouping = getenv("LOCALE_GROUPING");
1161 #endif
1162 if (!thousandsSeparator)
1163 thousandsSeparator = "'";
1164 if (!decimalPoint)
1165 decimalPoint = ".";
1166 if (!grouping)
1167 grouping = "\3\0";
1168
1169 /*
1170 * We use single malloc to get the memory for all separator and grouping
1171 * strings.
1172 */
1173 size_t thousandsSeparatorSize = strlen(thousandsSeparator) + 1;
1174 size_t decimalPointSize = strlen(decimalPoint) + 1;
1175 size_t groupingSize = strlen(grouping) + 1;
1176
1177 char *storage = js_pod_malloc<char>(thousandsSeparatorSize +
1178 decimalPointSize +
1179 groupingSize);
1180 if (!storage)
1181 return false;
1182
1183 js_memcpy(storage, thousandsSeparator, thousandsSeparatorSize);
1184 rt->thousandsSeparator = storage;
1185 storage += thousandsSeparatorSize;
1186
1187 js_memcpy(storage, decimalPoint, decimalPointSize);
1188 rt->decimalSeparator = storage;
1189 storage += decimalPointSize;
1190
1191 js_memcpy(storage, grouping, groupingSize);
1192 rt->numGrouping = grouping;
1193 #endif /* !EXPOSE_INTL_API */
1194 return true;
1195 }
1196
1197 #if !EXPOSE_INTL_API
1198 void
1199 js::FinishRuntimeNumberState(JSRuntime *rt)
1200 {
1201 /*
1202 * The free also releases the memory for decimalSeparator and numGrouping
1203 * strings.
1204 */
1205 char *storage = const_cast<char *>(rt->thousandsSeparator);
1206 js_free(storage);
1207 }
1208 #endif
1209
1210 JSObject *
1211 js_InitNumberClass(JSContext *cx, HandleObject obj)
1212 {
1213 JS_ASSERT(obj->isNative());
1214
1215 /* XXX must do at least once per new thread, so do it per JSContext... */
1216 FIX_FPU();
1217
1218 Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
1219
1220 RootedObject numberProto(cx, global->createBlankPrototype(cx, &NumberObject::class_));
1221 if (!numberProto)
1222 return nullptr;
1223 numberProto->as<NumberObject>().setPrimitiveValue(0);
1224
1225 RootedFunction ctor(cx);
1226 ctor = global->createConstructor(cx, Number, cx->names().Number, 1);
1227 if (!ctor)
1228 return nullptr;
1229
1230 if (!LinkConstructorAndPrototype(cx, ctor, numberProto))
1231 return nullptr;
1232
1233 /* Add numeric constants (MAX_VALUE, NaN, &c.) to the Number constructor. */
1234 if (!JS_DefineConstDoubles(cx, ctor, number_constants))
1235 return nullptr;
1236
1237 if (!DefinePropertiesAndBrand(cx, ctor, nullptr, number_static_methods))
1238 return nullptr;
1239
1240 if (!DefinePropertiesAndBrand(cx, numberProto, nullptr, number_methods))
1241 return nullptr;
1242
1243 if (!JS_DefineFunctions(cx, global, number_functions))
1244 return nullptr;
1245
1246 RootedValue valueNaN(cx, cx->runtime()->NaNValue);
1247 RootedValue valueInfinity(cx, cx->runtime()->positiveInfinityValue);
1248
1249 /* ES5 15.1.1.1, 15.1.1.2 */
1250 if (!DefineNativeProperty(cx, global, cx->names().NaN, valueNaN,
1251 JS_PropertyStub, JS_StrictPropertyStub,
1252 JSPROP_PERMANENT | JSPROP_READONLY) ||
1253 !DefineNativeProperty(cx, global, cx->names().Infinity, valueInfinity,
1254 JS_PropertyStub, JS_StrictPropertyStub,
1255 JSPROP_PERMANENT | JSPROP_READONLY))
1256 {
1257 return nullptr;
1258 }
1259
1260 if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_Number, ctor, numberProto))
1261 return nullptr;
1262
1263 return numberProto;
1264 }
1265
1266 static char *
1267 FracNumberToCString(ThreadSafeContext *cx, ToCStringBuf *cbuf, double d, int base = 10)
1268 {
1269 #ifdef DEBUG
1270 {
1271 int32_t _;
1272 JS_ASSERT(!mozilla::NumberIsInt32(d, &_));
1273 }
1274 #endif
1275
1276 char* numStr;
1277 if (base == 10) {
1278 /*
1279 * This is V8's implementation of the algorithm described in the
1280 * following paper:
1281 *
1282 * Printing floating-point numbers quickly and accurately with integers.
1283 * Florian Loitsch, PLDI 2010.
1284 */
1285 const double_conversion::DoubleToStringConverter &converter
1286 = double_conversion::DoubleToStringConverter::EcmaScriptConverter();
1287 double_conversion::StringBuilder builder(cbuf->sbuf, cbuf->sbufSize);
1288 converter.ToShortest(d, &builder);
1289 numStr = builder.Finalize();
1290 } else {
1291 numStr = cbuf->dbuf = js_dtobasestr(cx->dtoaState(), base, d);
1292 }
1293 return numStr;
1294 }
1295
1296 char *
1297 js::NumberToCString(JSContext *cx, ToCStringBuf *cbuf, double d, int base/* = 10*/)
1298 {
1299 int32_t i;
1300 size_t len;
1301 return mozilla::NumberIsInt32(d, &i)
1302 ? Int32ToCString(cbuf, i, &len, base)
1303 : FracNumberToCString(cx, cbuf, d, base);
1304 }
1305
1306 template <AllowGC allowGC>
1307 static JSString * JS_FASTCALL
1308 js_NumberToStringWithBase(ThreadSafeContext *cx, double d, int base)
1309 {
1310 ToCStringBuf cbuf;
1311 char *numStr;
1312
1313 /*
1314 * Caller is responsible for error reporting. When called from trace,
1315 * returning nullptr here will cause us to fall of trace and then retry
1316 * from the interpreter (which will report the error).
1317 */
1318 if (base < 2 || base > 36)
1319 return nullptr;
1320
1321 JSCompartment *comp = cx->isExclusiveContext()
1322 ? cx->asExclusiveContext()->compartment()
1323 : nullptr;
1324
1325 int32_t i;
1326 if (mozilla::NumberIsInt32(d, &i)) {
1327 if (base == 10 && StaticStrings::hasInt(i))
1328 return cx->staticStrings().getInt(i);
1329 if (unsigned(i) < unsigned(base)) {
1330 if (i < 10)
1331 return cx->staticStrings().getInt(i);
1332 jschar c = 'a' + i - 10;
1333 JS_ASSERT(StaticStrings::hasUnit(c));
1334 return cx->staticStrings().getUnit(c);
1335 }
1336
1337 if (comp) {
1338 if (JSFlatString *str = comp->dtoaCache.lookup(base, d))
1339 return str;
1340 }
1341
1342 size_t len;
1343 numStr = Int32ToCString(&cbuf, i, &len, base);
1344 JS_ASSERT(!cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize);
1345 } else {
1346 if (comp) {
1347 if (JSFlatString *str = comp->dtoaCache.lookup(base, d))
1348 return str;
1349 }
1350
1351 numStr = FracNumberToCString(cx, &cbuf, d, base);
1352 if (!numStr) {
1353 js_ReportOutOfMemory(cx);
1354 return nullptr;
1355 }
1356 JS_ASSERT_IF(base == 10,
1357 !cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize);
1358 JS_ASSERT_IF(base != 10,
1359 cbuf.dbuf && cbuf.dbuf == numStr);
1360 }
1361
1362 JSFlatString *s = js_NewStringCopyZ<allowGC>(cx, numStr);
1363
1364 if (comp)
1365 comp->dtoaCache.cache(base, d, s);
1366
1367 return s;
1368 }
1369
1370 template <AllowGC allowGC>
1371 JSString *
1372 js::NumberToString(ThreadSafeContext *cx, double d)
1373 {
1374 return js_NumberToStringWithBase<allowGC>(cx, d, 10);
1375 }
1376
1377 template JSString *
1378 js::NumberToString<CanGC>(ThreadSafeContext *cx, double d);
1379
1380 template JSString *
1381 js::NumberToString<NoGC>(ThreadSafeContext *cx, double d);
1382
1383 JSAtom *
1384 js::NumberToAtom(ExclusiveContext *cx, double d)
1385 {
1386 int32_t si;
1387 if (mozilla::NumberIsInt32(d, &si))
1388 return Int32ToAtom(cx, si);
1389
1390 if (JSFlatString *str = LookupDtoaCache(cx, d))
1391 return AtomizeString(cx, str);
1392
1393 ToCStringBuf cbuf;
1394 char *numStr = FracNumberToCString(cx, &cbuf, d);
1395 if (!numStr) {
1396 js_ReportOutOfMemory(cx);
1397 return nullptr;
1398 }
1399 JS_ASSERT(!cbuf.dbuf && numStr >= cbuf.sbuf && numStr < cbuf.sbuf + cbuf.sbufSize);
1400
1401 size_t length = strlen(numStr);
1402 JSAtom *atom = Atomize(cx, numStr, length);
1403 if (!atom)
1404 return nullptr;
1405
1406 CacheNumber(cx, d, atom);
1407
1408 return atom;
1409 }
1410
1411 JSFlatString *
1412 js::NumberToString(JSContext *cx, double d)
1413 {
1414 if (JSString *str = js_NumberToStringWithBase<CanGC>(cx, d, 10))
1415 return &str->asFlat();
1416 return nullptr;
1417 }
1418
1419 JSFlatString *
1420 js::IndexToString(JSContext *cx, uint32_t index)
1421 {
1422 if (StaticStrings::hasUint(index))
1423 return cx->staticStrings().getUint(index);
1424
1425 JSCompartment *c = cx->compartment();
1426 if (JSFlatString *str = c->dtoaCache.lookup(10, index))
1427 return str;
1428
1429 JSFatInlineString *str = js_NewGCFatInlineString<CanGC>(cx);
1430 if (!str)
1431 return nullptr;
1432
1433 jschar buffer[JSFatInlineString::MAX_FAT_INLINE_LENGTH + 1];
1434 RangedPtr<jschar> end(buffer + JSFatInlineString::MAX_FAT_INLINE_LENGTH,
1435 buffer, JSFatInlineString::MAX_FAT_INLINE_LENGTH + 1);
1436 *end = '\0';
1437 RangedPtr<jschar> start = BackfillIndexInCharBuffer(index, end);
1438
1439 jschar *dst = str->init(end - start);
1440 PodCopy(dst, start.get(), end - start + 1);
1441
1442 c->dtoaCache.cache(10, index, str);
1443 return str;
1444 }
1445
1446 bool JS_FASTCALL
1447 js::NumberValueToStringBuffer(JSContext *cx, const Value &v, StringBuffer &sb)
1448 {
1449 /* Convert to C-string. */
1450 ToCStringBuf cbuf;
1451 const char *cstr;
1452 size_t cstrlen;
1453 if (v.isInt32()) {
1454 cstr = Int32ToCString(&cbuf, v.toInt32(), &cstrlen);
1455 JS_ASSERT(cstrlen == strlen(cstr));
1456 } else {
1457 cstr = NumberToCString(cx, &cbuf, v.toDouble());
1458 if (!cstr) {
1459 JS_ReportOutOfMemory(cx);
1460 return false;
1461 }
1462 cstrlen = strlen(cstr);
1463 }
1464
1465 /*
1466 * Inflate to jschar string. The input C-string characters are < 127, so
1467 * even if jschars are UTF-8, all chars should map to one jschar.
1468 */
1469 JS_ASSERT(!cbuf.dbuf && cstrlen < cbuf.sbufSize);
1470 return sb.appendInflated(cstr, cstrlen);
1471 }
1472
1473 static bool
1474 CharsToNumber(ThreadSafeContext *cx, const jschar *chars, size_t length, double *result)
1475 {
1476 if (length == 1) {
1477 jschar c = chars[0];
1478 if ('0' <= c && c <= '9')
1479 *result = c - '0';
1480 else if (unicode::IsSpace(c))
1481 *result = 0.0;
1482 else
1483 *result = GenericNaN();
1484 return true;
1485 }
1486
1487 const jschar *end = chars + length;
1488 const jschar *bp = SkipSpace(chars, end);
1489
1490 /* ECMA doesn't allow signed hex numbers (bug 273467). */
1491 if (end - bp >= 2 && bp[0] == '0' && (bp[1] == 'x' || bp[1] == 'X')) {
1492 /*
1493 * It's probably a hex number. Accept if there's at least one hex
1494 * digit after the 0x, and if no non-whitespace characters follow all
1495 * the hex digits.
1496 */
1497 const jschar *endptr;
1498 double d;
1499 if (!GetPrefixInteger(cx, bp + 2, end, 16, &endptr, &d) ||
1500 endptr == bp + 2 ||
1501 SkipSpace(endptr, end) != end)
1502 {
1503 *result = GenericNaN();
1504 } else {
1505 *result = d;
1506 }
1507 return true;
1508 }
1509
1510 /*
1511 * Note that ECMA doesn't treat a string beginning with a '0' as
1512 * an octal number here. This works because all such numbers will
1513 * be interpreted as decimal by js_strtod. Also, any hex numbers
1514 * that have made it here (which can only be negative ones) will
1515 * be treated as 0 without consuming the 'x' by js_strtod.
1516 */
1517 const jschar *ep;
1518 double d;
1519 if (!js_strtod(cx, bp, end, &ep, &d)) {
1520 *result = GenericNaN();
1521 return false;
1522 }
1523
1524 if (SkipSpace(ep, end) != end)
1525 *result = GenericNaN();
1526 else
1527 *result = d;
1528
1529 return true;
1530 }
1531
1532 bool
1533 js::StringToNumber(ThreadSafeContext *cx, JSString *str, double *result)
1534 {
1535 ScopedThreadSafeStringInspector inspector(str);
1536 if (!inspector.ensureChars(cx))
1537 return false;
1538
1539 return CharsToNumber(cx, inspector.chars(), str->length(), result);
1540 }
1541
1542 bool
1543 js::NonObjectToNumberSlow(ThreadSafeContext *cx, Value v, double *out)
1544 {
1545 JS_ASSERT(!v.isNumber());
1546 JS_ASSERT(!v.isObject());
1547
1548 if (v.isString())
1549 return StringToNumber(cx, v.toString(), out);
1550 if (v.isBoolean()) {
1551 *out = v.toBoolean() ? 1.0 : 0.0;
1552 return true;
1553 }
1554 if (v.isNull()) {
1555 *out = 0.0;
1556 return true;
1557 }
1558
1559 JS_ASSERT(v.isUndefined());
1560 *out = GenericNaN();
1561 return true;
1562 }
1563
1564 #if defined(_MSC_VER)
1565 # pragma optimize("g", off)
1566 #endif
1567
1568 bool
1569 js::ToNumberSlow(ExclusiveContext *cx, Value v, double *out)
1570 {
1571 JS_ASSERT(!v.isNumber());
1572 goto skip_int_double;
1573 for (;;) {
1574 if (v.isNumber()) {
1575 *out = v.toNumber();
1576 return true;
1577 }
1578
1579 skip_int_double:
1580 if (!v.isObject())
1581 return NonObjectToNumberSlow(cx, v, out);
1582
1583 if (!cx->isJSContext())
1584 return false;
1585
1586 RootedValue v2(cx, v);
1587 if (!ToPrimitive(cx->asJSContext(), JSTYPE_NUMBER, &v2))
1588 return false;
1589 v = v2;
1590 if (v.isObject())
1591 break;
1592 }
1593
1594 *out = GenericNaN();
1595 return true;
1596 }
1597
1598 JS_PUBLIC_API(bool)
1599 js::ToNumberSlow(JSContext *cx, Value v, double *out)
1600 {
1601 return ToNumberSlow(static_cast<ExclusiveContext *>(cx), v, out);
1602 }
1603
1604 #if defined(_MSC_VER)
1605 # pragma optimize("", on)
1606 #endif
1607
1608 /*
1609 * Convert a value to an int64_t, according to the WebIDL rules for long long
1610 * conversion. Return converted value in *out on success, false on failure.
1611 */
1612 JS_PUBLIC_API(bool)
1613 js::ToInt64Slow(JSContext *cx, const HandleValue v, int64_t *out)
1614 {
1615 JS_ASSERT(!v.isInt32());
1616 double d;
1617 if (v.isDouble()) {
1618 d = v.toDouble();
1619 } else {
1620 if (!ToNumberSlow(cx, v, &d))
1621 return false;
1622 }
1623 *out = ToInt64(d);
1624 return true;
1625 }
1626
1627 /*
1628 * Convert a value to an uint64_t, according to the WebIDL rules for unsigned long long
1629 * conversion. Return converted value in *out on success, false on failure.
1630 */
1631 JS_PUBLIC_API(bool)
1632 js::ToUint64Slow(JSContext *cx, const HandleValue v, uint64_t *out)
1633 {
1634 JS_ASSERT(!v.isInt32());
1635 double d;
1636 if (v.isDouble()) {
1637 d = v.toDouble();
1638 } else {
1639 if (!ToNumberSlow(cx, v, &d))
1640 return false;
1641 }
1642 *out = ToUint64(d);
1643 return true;
1644 }
1645
1646 template <typename ContextType,
1647 bool (*ToNumberSlowFn)(ContextType *, Value, double *),
1648 typename ValueType>
1649 static bool
1650 ToInt32SlowImpl(ContextType *cx, const ValueType v, int32_t *out)
1651 {
1652 JS_ASSERT(!v.isInt32());
1653 double d;
1654 if (v.isDouble()) {
1655 d = v.toDouble();
1656 } else {
1657 if (!ToNumberSlowFn(cx, v, &d))
1658 return false;
1659 }
1660 *out = ToInt32(d);
1661 return true;
1662 }
1663
1664 JS_PUBLIC_API(bool)
1665 js::ToInt32Slow(JSContext *cx, const HandleValue v, int32_t *out)
1666 {
1667 return ToInt32SlowImpl<JSContext, ToNumberSlow>(cx, v, out);
1668 }
1669
1670 bool
1671 js::NonObjectToInt32Slow(ThreadSafeContext *cx, const Value &v, int32_t *out)
1672 {
1673 return ToInt32SlowImpl<ThreadSafeContext, NonObjectToNumberSlow>(cx, v, out);
1674 }
1675
1676 template <typename ContextType,
1677 bool (*ToNumberSlowFn)(ContextType *, Value, double *),
1678 typename ValueType>
1679 static bool
1680 ToUint32SlowImpl(ContextType *cx, const ValueType v, uint32_t *out)
1681 {
1682 JS_ASSERT(!v.isInt32());
1683 double d;
1684 if (v.isDouble()) {
1685 d = v.toDouble();
1686 } else {
1687 if (!ToNumberSlowFn(cx, v, &d))
1688 return false;
1689 }
1690 *out = ToUint32(d);
1691 return true;
1692 }
1693
1694 JS_PUBLIC_API(bool)
1695 js::ToUint32Slow(JSContext *cx, const HandleValue v, uint32_t *out)
1696 {
1697 return ToUint32SlowImpl<JSContext, ToNumberSlow>(cx, v, out);
1698 }
1699
1700 bool
1701 js::NonObjectToUint32Slow(ThreadSafeContext *cx, const Value &v, uint32_t *out)
1702 {
1703 return ToUint32SlowImpl<ThreadSafeContext, NonObjectToNumberSlow>(cx, v, out);
1704 }
1705
1706 JS_PUBLIC_API(bool)
1707 js::ToUint16Slow(JSContext *cx, const HandleValue v, uint16_t *out)
1708 {
1709 JS_ASSERT(!v.isInt32());
1710 double d;
1711 if (v.isDouble()) {
1712 d = v.toDouble();
1713 } else if (!ToNumberSlow(cx, v, &d)) {
1714 return false;
1715 }
1716
1717 if (d == 0 || !mozilla::IsFinite(d)) {
1718 *out = 0;
1719 return true;
1720 }
1721
1722 uint16_t u = (uint16_t) d;
1723 if ((double)u == d) {
1724 *out = u;
1725 return true;
1726 }
1727
1728 bool neg = (d < 0);
1729 d = floor(neg ? -d : d);
1730 d = neg ? -d : d;
1731 unsigned m = JS_BIT(16);
1732 d = fmod(d, (double) m);
1733 if (d < 0)
1734 d += m;
1735 *out = (uint16_t) d;
1736 return true;
1737 }
1738
1739 bool
1740 js_strtod(ThreadSafeContext *cx, const jschar *s, const jschar *send,
1741 const jschar **ep, double *dp)
1742 {
1743 size_t i;
1744 char cbuf[32];
1745 char *cstr, *istr, *estr;
1746 bool negative;
1747 double d;
1748
1749 const jschar *s1 = SkipSpace(s, send);
1750 size_t length = send - s1;
1751
1752 /* Use cbuf to avoid malloc */
1753 if (length >= sizeof cbuf) {
1754 cstr = (char *) cx->malloc_(length + 1);
1755 if (!cstr)
1756 return false;
1757 } else {
1758 cstr = cbuf;
1759 }
1760
1761 for (i = 0; i != length; i++) {
1762 if (s1[i] >> 8)
1763 break;
1764 cstr[i] = (char)s1[i];
1765 }
1766 cstr[i] = 0;
1767
1768 istr = cstr;
1769 if ((negative = (*istr == '-')) != 0 || *istr == '+')
1770 istr++;
1771 if (*istr == 'I' && !strncmp(istr, "Infinity", 8)) {
1772 d = negative ? NegativeInfinity<double>() : PositiveInfinity<double>();
1773 estr = istr + 8;
1774 } else {
1775 int err;
1776 d = js_strtod_harder(cx->dtoaState(), cstr, &estr, &err);
1777 }
1778
1779 i = estr - cstr;
1780 if (cstr != cbuf)
1781 js_free(cstr);
1782 *ep = i ? s1 + i : s;
1783 *dp = d;
1784 return true;
1785 }

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