/*
* Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
- * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
* Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
* Copyright (C) 2007 Maks Orlovich
*
#include "CallFrame.h"
#include "Interpreter.h"
+#include "JSFunction.h"
#include "JSGlobalObject.h"
#include "JSString.h"
#include "JSStringBuilder.h"
#include "Lexer.h"
#include "LiteralParser.h"
#include "Nodes.h"
+#include "Operations.h"
#include "Parser.h"
-#include "UStringBuilder.h"
-#include "dtoa.h"
+#include <wtf/dtoa.h>
#include <stdio.h>
#include <stdlib.h>
#include <wtf/ASCIICType.h>
#include <wtf/Assertions.h>
#include <wtf/MathExtras.h>
#include <wtf/StringExtras.h>
+#include <wtf/text/StringBuilder.h>
#include <wtf/unicode/UTF8.h>
using namespace WTF;
static JSValue encode(ExecState* exec, const char* doNotEscape)
{
- UString str = exec->argument(0).toString(exec);
- CString cstr = str.utf8(true);
+ CString cstr = exec->argument(0).toString(exec)->value(exec).utf8(String::StrictConversion);
if (!cstr.data())
- return throwError(exec, createURIError(exec, "String contained an illegal UTF-16 sequence."));
+ return throwError(exec, createURIError(exec, ASCIILiteral("String contained an illegal UTF-16 sequence.")));
JSStringBuilder builder;
const char* p = cstr.data();
return builder.build(exec);
}
-static JSValue decode(ExecState* exec, const char* doNotUnescape, bool strict)
+template <typename CharType>
+ALWAYS_INLINE
+static JSValue decode(ExecState* exec, const CharType* characters, int length, const char* doNotUnescape, bool strict)
{
JSStringBuilder builder;
- UString str = exec->argument(0).toString(exec);
int k = 0;
- int len = str.length();
- const UChar* d = str.characters();
UChar u = 0;
- while (k < len) {
- const UChar* p = d + k;
- UChar c = *p;
+ while (k < length) {
+ const CharType* p = characters + k;
+ CharType c = *p;
if (c == '%') {
int charLen = 0;
- if (k <= len - 3 && isASCIIHexDigit(p[1]) && isASCIIHexDigit(p[2])) {
- const char b0 = Lexer::convertHex(p[1], p[2]);
+ if (k <= length - 3 && isASCIIHexDigit(p[1]) && isASCIIHexDigit(p[2])) {
+ const char b0 = Lexer<CharType>::convertHex(p[1], p[2]);
const int sequenceLen = UTF8SequenceLength(b0);
- if (sequenceLen != 0 && k <= len - sequenceLen * 3) {
+ if (sequenceLen && k <= length - sequenceLen * 3) {
charLen = sequenceLen * 3;
char sequence[5];
sequence[0] = b0;
for (int i = 1; i < sequenceLen; ++i) {
- const UChar* q = p + i * 3;
+ const CharType* q = p + i * 3;
if (q[0] == '%' && isASCIIHexDigit(q[1]) && isASCIIHexDigit(q[2]))
- sequence[i] = Lexer::convertHex(q[1], q[2]);
+ sequence[i] = Lexer<CharType>::convertHex(q[1], q[2]);
else {
charLen = 0;
break;
}
if (charLen == 0) {
if (strict)
- return throwError(exec, createURIError(exec, "URI error"));
+ return throwError(exec, createURIError(exec, ASCIILiteral("URI error")));
// The only case where we don't use "strict" mode is the "unescape" function.
// For that, it's good to support the wonky "%u" syntax for compatibility with WinIE.
- if (k <= len - 6 && p[1] == 'u'
+ if (k <= length - 6 && p[1] == 'u'
&& isASCIIHexDigit(p[2]) && isASCIIHexDigit(p[3])
&& isASCIIHexDigit(p[4]) && isASCIIHexDigit(p[5])) {
charLen = 6;
- u = Lexer::convertUnicode(p[2], p[3], p[4], p[5]);
+ u = Lexer<UChar>::convertUnicode(p[2], p[3], p[4], p[5]);
}
}
if (charLen && (u == 0 || u >= 128 || !strchr(doNotUnescape, u))) {
- c = u;
- k += charLen - 1;
+ if (u < 256)
+ builder.append(static_cast<LChar>(u));
+ else
+ builder.append(u);
+ k += charLen;
+ continue;
}
}
k++;
return builder.build(exec);
}
+static JSValue decode(ExecState* exec, const char* doNotUnescape, bool strict)
+{
+ JSStringBuilder builder;
+ String str = exec->argument(0).toString(exec)->value(exec);
+
+ if (str.is8Bit())
+ return decode(exec, str.characters8(), str.length(), doNotUnescape, strict);
+ return decode(exec, str.characters16(), str.length(), doNotUnescape, strict);
+}
+
bool isStrWhiteSpace(UChar c)
{
switch (c) {
return digit;
}
-double parseIntOverflow(const char* s, int length, int radix)
+double parseIntOverflow(const LChar* s, int length, int radix)
{
double number = 0.0;
double radixMultiplier = 1.0;
- for (const char* p = s + length - 1; p >= s; p--) {
- if (radixMultiplier == Inf) {
+ for (const LChar* p = s + length - 1; p >= s; p--) {
+ if (radixMultiplier == std::numeric_limits<double>::infinity()) {
if (*p != '0') {
- number = Inf;
+ number = std::numeric_limits<double>::infinity();
break;
}
} else {
double radixMultiplier = 1.0;
for (const UChar* p = s + length - 1; p >= s; p--) {
- if (radixMultiplier == Inf) {
+ if (radixMultiplier == std::numeric_limits<double>::infinity()) {
if (*p != '0') {
- number = Inf;
+ number = std::numeric_limits<double>::infinity();
break;
}
} else {
return number;
}
-static double parseInt(const UString& s, int radix)
+// ES5.1 15.1.2.2
+template <typename CharType>
+ALWAYS_INLINE
+static double parseInt(const String& s, const CharType* data, int radix)
{
+ // 1. Let inputString be ToString(string).
+ // 2. Let S be a newly created substring of inputString consisting of the first character that is not a
+ // StrWhiteSpaceChar and all characters following that character. (In other words, remove leading white
+ // space.) If inputString does not contain any such characters, let S be the empty string.
int length = s.length();
- const UChar* data = s.characters();
int p = 0;
-
while (p < length && isStrWhiteSpace(data[p]))
++p;
+ // 3. Let sign be 1.
+ // 4. If S is not empty and the first character of S is a minus sign -, let sign be -1.
+ // 5. If S is not empty and the first character of S is a plus sign + or a minus sign -, then remove the first character from S.
double sign = 1;
if (p < length) {
if (data[p] == '+')
}
}
+ // 6. Let R = ToInt32(radix).
+ // 7. Let stripPrefix be true.
+ // 8. If R != 0,then
+ // b. If R != 16, let stripPrefix be false.
+ // 9. Else, R == 0
+ // a. LetR = 10.
+ // 10. If stripPrefix is true, then
+ // a. If the length of S is at least 2 and the first two characters of S are either ―0x or ―0X,
+ // then remove the first two characters from S and let R = 16.
+ // 11. If S contains any character that is not a radix-R digit, then let Z be the substring of S
+ // consisting of all characters before the first such character; otherwise, let Z be S.
if ((radix == 0 || radix == 16) && length - p >= 2 && data[p] == '0' && (data[p + 1] == 'x' || data[p + 1] == 'X')) {
radix = 16;
p += 2;
- } else if (radix == 0) {
- if (p < length && data[p] == '0')
- radix = 8;
- else
- radix = 10;
- }
+ } else if (radix == 0)
+ radix = 10;
+ // 8.a If R < 2 or R > 36, then return NaN.
if (radix < 2 || radix > 36)
- return NaN;
-
+ return QNaN;
+
+ // 13. Let mathInt be the mathematical integer value that is represented by Z in radix-R notation, using the letters
+ // A-Z and a-z for digits with values 10 through 35. (However, if R is 10 and Z contains more than 20 significant
+ // digits, every significant digit after the 20th may be replaced by a 0 digit, at the option of the implementation;
+ // and if R is not 2, 4, 8, 10, 16, or 32, then mathInt may be an implementation-dependent approximation to the
+ // mathematical integer value that is represented by Z in radix-R notation.)
+ // 14. Let number be the Number value for mathInt.
int firstDigitPosition = p;
bool sawDigit = false;
double number = 0;
++p;
}
+ // 12. If Z is empty, return NaN.
+ if (!sawDigit)
+ return QNaN;
+
+ // Alternate code path for certain large numbers.
if (number >= mantissaOverflowLowerBound) {
- if (radix == 10)
- number = WTF::strtod(s.substringSharingImpl(firstDigitPosition, p - firstDigitPosition).utf8().data(), 0);
- else if (radix == 2 || radix == 4 || radix == 8 || radix == 16 || radix == 32)
+ if (radix == 10) {
+ size_t parsedLength;
+ number = parseDouble(s.characters() + firstDigitPosition, p - firstDigitPosition, parsedLength);
+ } else if (radix == 2 || radix == 4 || radix == 8 || radix == 16 || radix == 32)
number = parseIntOverflow(s.substringSharingImpl(firstDigitPosition, p - firstDigitPosition).utf8().data(), p - firstDigitPosition, radix);
}
- if (!sawDigit)
- return NaN;
-
+ // 15. Return sign x number.
return sign * number;
}
+static double parseInt(const String& s, int radix)
+{
+ if (s.is8Bit())
+ return parseInt(s, s.characters8(), radix);
+ return parseInt(s, s.characters16(), radix);
+}
+
static const int SizeOfInfinity = 8;
-static bool isInfinity(const UChar* data, const UChar* end)
+template <typename CharType>
+static bool isInfinity(const CharType* data, const CharType* end)
{
return (end - data) >= SizeOfInfinity
&& data[0] == 'I'
}
// See ecma-262 9.3.1
-static double jsHexIntegerLiteral(const UChar*& data, const UChar* end)
+template <typename CharType>
+static double jsHexIntegerLiteral(const CharType*& data, const CharType* end)
{
// Hex number.
data += 2;
- const UChar* firstDigitPosition = data;
+ const CharType* firstDigitPosition = data;
double number = 0;
while (true) {
number = number * 16 + toASCIIHexValue(*data);
}
// See ecma-262 9.3.1
-static double jsStrDecimalLiteral(const UChar*& data, const UChar* end)
+template <typename CharType>
+static double jsStrDecimalLiteral(const CharType*& data, const CharType* end)
{
- ASSERT(data < end);
+ RELEASE_ASSERT(data < end);
- // Copy the sting into a null-terminated byte buffer, and call strtod.
- Vector<char, 32> byteBuffer;
- for (const UChar* characters = data; characters < end; ++characters) {
- UChar character = *characters;
- byteBuffer.append(isASCII(character) ? character : 0);
- }
- byteBuffer.append(0);
- char* endOfNumber;
- double number = WTF::strtod(byteBuffer.data(), &endOfNumber);
-
- // Check if strtod found a number; if so return it.
- ptrdiff_t consumed = endOfNumber - byteBuffer.data();
- if (consumed) {
- data += consumed;
+ size_t parsedLength;
+ double number = parseDouble(data, end - data, parsedLength);
+ if (parsedLength) {
+ data += parsedLength;
return number;
}
case 'I':
if (isInfinity(data, end)) {
data += SizeOfInfinity;
- return Inf;
+ return std::numeric_limits<double>::infinity();
}
break;
case '+':
if (isInfinity(data + 1, end)) {
data += SizeOfInfinity + 1;
- return Inf;
+ return std::numeric_limits<double>::infinity();
}
break;
case '-':
if (isInfinity(data + 1, end)) {
data += SizeOfInfinity + 1;
- return -Inf;
+ return -std::numeric_limits<double>::infinity();
}
break;
}
// Not a number.
- return NaN;
+ return QNaN;
}
-// See ecma-262 9.3.1
-double jsToNumber(const UString& s)
+template <typename CharType>
+static double toDouble(const CharType* characters, unsigned size)
{
- unsigned size = s.length();
-
- if (size == 1) {
- UChar c = s.characters()[0];
- if (isASCIIDigit(c))
- return c - '0';
- if (isStrWhiteSpace(c))
- return 0;
- return NaN;
- }
-
- const UChar* data = s.characters();
- const UChar* end = data + size;
+ const CharType* endCharacters = characters + size;
// Skip leading white space.
- for (; data < end; ++data) {
- if (!isStrWhiteSpace(*data))
+ for (; characters < endCharacters; ++characters) {
+ if (!isStrWhiteSpace(*characters))
break;
}
-
+
// Empty string.
- if (data == end)
+ if (characters == endCharacters)
return 0.0;
-
+
double number;
- if (data[0] == '0' && data + 2 < end && (data[1] | 0x20) == 'x' && isASCIIHexDigit(data[2]))
- number = jsHexIntegerLiteral(data, end);
+ if (characters[0] == '0' && characters + 2 < endCharacters && (characters[1] | 0x20) == 'x' && isASCIIHexDigit(characters[2]))
+ number = jsHexIntegerLiteral(characters, endCharacters);
else
- number = jsStrDecimalLiteral(data, end);
-
+ number = jsStrDecimalLiteral(characters, endCharacters);
+
// Allow trailing white space.
- for (; data < end; ++data) {
- if (!isStrWhiteSpace(*data))
+ for (; characters < endCharacters; ++characters) {
+ if (!isStrWhiteSpace(*characters))
break;
}
- if (data != end)
- return NaN;
-
+ if (characters != endCharacters)
+ return QNaN;
+
return number;
}
-static double parseFloat(const UString& s)
+// See ecma-262 9.3.1
+double jsToNumber(const String& s)
{
unsigned size = s.length();
if (size == 1) {
- UChar c = s.characters()[0];
+ UChar c = s[0];
if (isASCIIDigit(c))
return c - '0';
- return NaN;
+ if (isStrWhiteSpace(c))
+ return 0;
+ return QNaN;
}
- const UChar* data = s.characters();
+ if (s.is8Bit())
+ return toDouble(s.characters8(), size);
+ return toDouble(s.characters16(), size);
+}
+
+static double parseFloat(const String& s)
+{
+ unsigned size = s.length();
+
+ if (size == 1) {
+ UChar c = s[0];
+ if (isASCIIDigit(c))
+ return c - '0';
+ return QNaN;
+ }
+
+ if (s.is8Bit()) {
+ const LChar* data = s.characters8();
+ const LChar* end = data + size;
+
+ // Skip leading white space.
+ for (; data < end; ++data) {
+ if (!isStrWhiteSpace(*data))
+ break;
+ }
+
+ // Empty string.
+ if (data == end)
+ return QNaN;
+
+ return jsStrDecimalLiteral(data, end);
+ }
+
+ const UChar* data = s.characters16();
const UChar* end = data + size;
// Skip leading white space.
// Empty string.
if (data == end)
- return NaN;
+ return QNaN;
return jsStrDecimalLiteral(data, end);
}
EncodedJSValue JSC_HOST_CALL globalFuncEval(ExecState* exec)
{
- JSObject* thisObject = exec->hostThisValue().toThisObject(exec);
- JSObject* unwrappedObject = thisObject->unwrappedObject();
- if (!unwrappedObject->isGlobalObject() || static_cast<JSGlobalObject*>(unwrappedObject)->evalFunction() != exec->callee())
- return throwVMError(exec, createEvalError(exec, "The \"this\" value passed to eval must be the global object from which eval originated"));
-
JSValue x = exec->argument(0);
if (!x.isString())
return JSValue::encode(x);
- UString s = x.toString(exec);
+ String s = x.toString(exec)->value(exec);
- LiteralParser preparser(exec, s.characters(), s.length(), LiteralParser::NonStrictJSON);
- if (JSValue parsedObject = preparser.tryLiteralParse())
- return JSValue::encode(parsedObject);
+ if (s.is8Bit()) {
+ LiteralParser<LChar> preparser(exec, s.characters8(), s.length(), NonStrictJSON);
+ if (JSValue parsedObject = preparser.tryLiteralParse())
+ return JSValue::encode(parsedObject);
+ } else {
+ LiteralParser<UChar> preparser(exec, s.characters16(), s.length(), NonStrictJSON);
+ if (JSValue parsedObject = preparser.tryLiteralParse())
+ return JSValue::encode(parsedObject);
+ }
- EvalExecutable* eval = EvalExecutable::create(exec, makeSource(s), false);
- JSObject* error = eval->compile(exec, static_cast<JSGlobalObject*>(unwrappedObject)->globalScopeChain());
+ JSGlobalObject* calleeGlobalObject = exec->callee()->globalObject();
+ EvalExecutable* eval = EvalExecutable::create(exec, exec->vm().codeCache(), makeSource(s), false);
+ JSObject* error = eval->compile(exec, calleeGlobalObject);
if (error)
return throwVMError(exec, error);
- return JSValue::encode(exec->interpreter()->execute(eval, exec, thisObject, static_cast<JSGlobalObject*>(unwrappedObject)->globalScopeChain()));
+ return JSValue::encode(exec->interpreter()->execute(eval, exec, calleeGlobalObject->globalThis(), calleeGlobalObject));
}
EncodedJSValue JSC_HOST_CALL globalFuncParseInt(ExecState* exec)
{
JSValue value = exec->argument(0);
- int32_t radix = exec->argument(1).toInt32(exec);
-
- if (radix != 0 && radix != 10)
- return JSValue::encode(jsNumber(parseInt(value.toString(exec), radix)));
-
- if (value.isInt32())
- return JSValue::encode(value);
-
- if (value.isDouble()) {
- double d = value.asDouble();
- if (isfinite(d))
- return JSValue::encode(jsNumber((d > 0) ? floor(d) : ceil(d)));
- if (isnan(d) || isinf(d))
- return JSValue::encode(jsNaN());
- return JSValue::encode(jsNumber(0));
+ JSValue radixValue = exec->argument(1);
+
+ // Optimized handling for numbers:
+ // If the argument is 0 or a number in range 10^-6 <= n < INT_MAX+1, then parseInt
+ // results in a truncation to integer. In the case of -0, this is converted to 0.
+ //
+ // This is also a truncation for values in the range INT_MAX+1 <= n < 10^21,
+ // however these values cannot be trivially truncated to int since 10^21 exceeds
+ // even the int64_t range. Negative numbers are a little trickier, the case for
+ // values in the range -10^21 < n <= -1 are similar to those for integer, but
+ // values in the range -1 < n <= -10^-6 need to truncate to -0, not 0.
+ static const double tenToTheMinus6 = 0.000001;
+ static const double intMaxPlusOne = 2147483648.0;
+ if (value.isNumber()) {
+ double n = value.asNumber();
+ if (((n < intMaxPlusOne && n >= tenToTheMinus6) || !n) && radixValue.isUndefinedOrNull())
+ return JSValue::encode(jsNumber(static_cast<int32_t>(n)));
}
- return JSValue::encode(jsNumber(parseInt(value.toString(exec), radix)));
+ // If ToString throws, we shouldn't call ToInt32.
+ String s = value.toString(exec)->value(exec);
+ if (exec->hadException())
+ return JSValue::encode(jsUndefined());
+
+ return JSValue::encode(jsNumber(parseInt(s, radixValue.toInt32(exec))));
}
EncodedJSValue JSC_HOST_CALL globalFuncParseFloat(ExecState* exec)
{
- return JSValue::encode(jsNumber(parseFloat(exec->argument(0).toString(exec))));
+ return JSValue::encode(jsNumber(parseFloat(exec->argument(0).toString(exec)->value(exec))));
}
EncodedJSValue JSC_HOST_CALL globalFuncIsNaN(ExecState* exec)
{
- return JSValue::encode(jsBoolean(isnan(exec->argument(0).toNumber(exec))));
+ return JSValue::encode(jsBoolean(std::isnan(exec->argument(0).toNumber(exec))));
}
EncodedJSValue JSC_HOST_CALL globalFuncIsFinite(ExecState* exec)
{
double n = exec->argument(0).toNumber(exec);
- return JSValue::encode(jsBoolean(!isnan(n) && !isinf(n)));
+ return JSValue::encode(jsBoolean(std::isfinite(n)));
}
EncodedJSValue JSC_HOST_CALL globalFuncDecodeURI(ExecState* exec)
"*+-./@_";
JSStringBuilder builder;
- UString str = exec->argument(0).toString(exec);
- const UChar* c = str.characters();
+ String str = exec->argument(0).toString(exec)->value(exec);
+ if (str.is8Bit()) {
+ const LChar* c = str.characters8();
+ for (unsigned k = 0; k < str.length(); k++, c++) {
+ int u = c[0];
+ if (u && strchr(do_not_escape, static_cast<char>(u)))
+ builder.append(c, 1);
+ else {
+ char tmp[4];
+ snprintf(tmp, sizeof(tmp), "%%%02X", u);
+ builder.append(tmp);
+ }
+ }
+
+ return JSValue::encode(builder.build(exec));
+ }
+
+ const UChar* c = str.characters16();
for (unsigned k = 0; k < str.length(); k++, c++) {
int u = c[0];
if (u > 255) {
EncodedJSValue JSC_HOST_CALL globalFuncUnescape(ExecState* exec)
{
- UStringBuilder builder;
- UString str = exec->argument(0).toString(exec);
+ StringBuilder builder;
+ String str = exec->argument(0).toString(exec)->value(exec);
int k = 0;
int len = str.length();
- while (k < len) {
- const UChar* c = str.characters() + k;
- UChar u;
- if (c[0] == '%' && k <= len - 6 && c[1] == 'u') {
- if (isASCIIHexDigit(c[2]) && isASCIIHexDigit(c[3]) && isASCIIHexDigit(c[4]) && isASCIIHexDigit(c[5])) {
- u = Lexer::convertUnicode(c[2], c[3], c[4], c[5]);
- c = &u;
- k += 5;
+
+ if (str.is8Bit()) {
+ const LChar* characters = str.characters8();
+ LChar convertedLChar;
+ while (k < len) {
+ const LChar* c = characters + k;
+ if (c[0] == '%' && k <= len - 6 && c[1] == 'u') {
+ if (isASCIIHexDigit(c[2]) && isASCIIHexDigit(c[3]) && isASCIIHexDigit(c[4]) && isASCIIHexDigit(c[5])) {
+ builder.append(Lexer<UChar>::convertUnicode(c[2], c[3], c[4], c[5]));
+ k += 6;
+ continue;
+ }
+ } else if (c[0] == '%' && k <= len - 3 && isASCIIHexDigit(c[1]) && isASCIIHexDigit(c[2])) {
+ convertedLChar = LChar(Lexer<LChar>::convertHex(c[1], c[2]));
+ c = &convertedLChar;
+ k += 2;
+ }
+ builder.append(*c);
+ k++;
+ }
+ } else {
+ const UChar* characters = str.characters16();
+
+ while (k < len) {
+ const UChar* c = characters + k;
+ UChar convertedUChar;
+ if (c[0] == '%' && k <= len - 6 && c[1] == 'u') {
+ if (isASCIIHexDigit(c[2]) && isASCIIHexDigit(c[3]) && isASCIIHexDigit(c[4]) && isASCIIHexDigit(c[5])) {
+ convertedUChar = Lexer<UChar>::convertUnicode(c[2], c[3], c[4], c[5]);
+ c = &convertedUChar;
+ k += 5;
+ }
+ } else if (c[0] == '%' && k <= len - 3 && isASCIIHexDigit(c[1]) && isASCIIHexDigit(c[2])) {
+ convertedUChar = UChar(Lexer<UChar>::convertHex(c[1], c[2]));
+ c = &convertedUChar;
+ k += 2;
}
- } else if (c[0] == '%' && k <= len - 3 && isASCIIHexDigit(c[1]) && isASCIIHexDigit(c[2])) {
- u = UChar(Lexer::convertHex(c[1], c[2]));
- c = &u;
- k += 2;
+ k++;
+ builder.append(*c);
}
- k++;
- builder.append(*c);
}
- return JSValue::encode(jsString(exec, builder.toUString()));
+ return JSValue::encode(jsString(exec, builder.toString()));
+}
+
+EncodedJSValue JSC_HOST_CALL globalFuncThrowTypeError(ExecState* exec)
+{
+ return throwVMTypeError(exec);
+}
+
+EncodedJSValue JSC_HOST_CALL globalFuncProtoGetter(ExecState* exec)
+{
+ if (!exec->thisValue().isObject())
+ return JSValue::encode(exec->thisValue().synthesizePrototype(exec));
+
+ JSObject* thisObject = asObject(exec->thisValue());
+ if (!thisObject->allowsAccessFrom(exec->trueCallerFrame()))
+ return JSValue::encode(jsUndefined());
+
+ return JSValue::encode(thisObject->prototype());
+}
+
+EncodedJSValue JSC_HOST_CALL globalFuncProtoSetter(ExecState* exec)
+{
+ JSValue value = exec->argument(0);
+
+ // Setting __proto__ of a primitive should have no effect.
+ if (!exec->thisValue().isObject())
+ return JSValue::encode(jsUndefined());
+
+ JSObject* thisObject = asObject(exec->thisValue());
+ if (!thisObject->allowsAccessFrom(exec->trueCallerFrame()))
+ return JSValue::encode(jsUndefined());
+
+ // Setting __proto__ to a non-object, non-null value is silently ignored to match Mozilla.
+ if (!value.isObject() && !value.isNull())
+ return JSValue::encode(jsUndefined());
+
+ if (!thisObject->isExtensible())
+ return throwVMError(exec, createTypeError(exec, StrictModeReadonlyPropertyWriteError));
+
+ if (!thisObject->setPrototypeWithCycleCheck(exec->vm(), value))
+ throwError(exec, createError(exec, "cyclic __proto__ value"));
+ return JSValue::encode(jsUndefined());
}
} // namespace JSC