diff -r 000000000000 -r 6474c204b198 js/src/jsstr.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsstr.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,4943 @@
+/* -*- 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 string type implementation.
+ *
+ * In order to avoid unnecessary js_LockGCThing/js_UnlockGCThing calls, these
+ * native methods store strings (possibly newborn) converted from their 'this'
+ * parameter and arguments on the stack: 'this' conversions at argv[-1], arg
+ * conversions at their index (argv[0], argv[1]).  This is a legitimate method
+ * of rooting things that might lose their newborn root due to subsequent GC
+ * allocations in the same native method.
+ */
+
+#include "jsstr.h"
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Casting.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/PodOperations.h"
+
+#include <ctype.h>
+#include <string.h>
+
+#include "jsapi.h"
+#include "jsarray.h"
+#include "jsatom.h"
+#include "jsbool.h"
+#include "jscntxt.h"
+#include "jsgc.h"
+#include "jsnum.h"
+#include "jsobj.h"
+#include "jsopcode.h"
+#include "jstypes.h"
+#include "jsutil.h"
+
+#include "builtin/Intl.h"
+#include "builtin/RegExp.h"
+#if ENABLE_INTL_API
+#include "unicode/unorm.h"
+#endif
+#include "vm/GlobalObject.h"
+#include "vm/Interpreter.h"
+#include "vm/NumericConversions.h"
+#include "vm/Opcodes.h"
+#include "vm/RegExpObject.h"
+#include "vm/RegExpStatics.h"
+#include "vm/ScopeObject.h"
+#include "vm/StringBuffer.h"
+
+#include "jsinferinlines.h"
+
+#include "vm/Interpreter-inl.h"
+#include "vm/String-inl.h"
+#include "vm/StringObject-inl.h"
+
+using namespace js;
+using namespace js::gc;
+using namespace js::types;
+using namespace js::unicode;
+
+using mozilla::CheckedInt;
+using mozilla::IsNaN;
+using mozilla::IsNegativeZero;
+using mozilla::PodCopy;
+using mozilla::PodEqual;
+using mozilla::SafeCast;
+
+typedef Handle<JSLinearString*> HandleLinearString;
+
+static JSLinearString *
+ArgToRootedString(JSContext *cx, CallArgs &args, unsigned argno)
+{
+    if (argno >= args.length())
+        return cx->names().undefined;
+
+    JSString *str = ToString<CanGC>(cx, args[argno]);
+    if (!str)
+        return nullptr;
+
+    args[argno].setString(str);
+    return str->ensureLinear(cx);
+}
+
+/*
+ * Forward declarations for URI encode/decode and helper routines
+ */
+static bool
+str_decodeURI(JSContext *cx, unsigned argc, Value *vp);
+
+static bool
+str_decodeURI_Component(JSContext *cx, unsigned argc, Value *vp);
+
+static bool
+str_encodeURI(JSContext *cx, unsigned argc, Value *vp);
+
+static bool
+str_encodeURI_Component(JSContext *cx, unsigned argc, Value *vp);
+
+/*
+ * Global string methods
+ */
+
+
+/* ES5 B.2.1 */
+static bool
+str_escape(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    static const char digits[] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                                  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
+
+    JSLinearString *str = ArgToRootedString(cx, args, 0);
+    if (!str)
+        return false;
+
+    size_t length = str->length();
+    const jschar *chars = str->chars();
+
+    static const uint8_t shouldPassThrough[256] = {
+         0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+         0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+         0,0,0,0,0,0,0,0,0,0,1,1,0,1,1,1,       /*    !"#$%&'()*+,-./  */
+         1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,       /*   0123456789:;<=>?  */
+         1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,       /*   @ABCDEFGHIJKLMNO  */
+         1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,1,       /*   PQRSTUVWXYZ[\]^_  */
+         0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,       /*   `abcdefghijklmno  */
+         1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,     /*   pqrstuvwxyz{\}~  DEL */
+    };
+
+    /* In step 7, exactly 69 characters should pass through unencoded. */
+#ifdef DEBUG
+    size_t count = 0;
+    for (size_t i = 0; i < sizeof(shouldPassThrough); i++) {
+        if (shouldPassThrough[i]) {
+            count++;
+        }
+    }
+    JS_ASSERT(count == 69);
+#endif
+
+
+    /* Take a first pass and see how big the result string will need to be. */
+    size_t newlength = length;
+    for (size_t i = 0; i < length; i++) {
+        jschar ch = chars[i];
+        if (ch < 128 && shouldPassThrough[ch])
+            continue;
+
+        /* The character will be encoded as %XX or %uXXXX. */
+        newlength += (ch < 256) ? 2 : 5;
+
+        /*
+         * This overflow test works because newlength is incremented by at
+         * most 5 on each iteration.
+         */
+        if (newlength < length) {
+            js_ReportAllocationOverflow(cx);
+            return false;
+        }
+    }
+
+    if (newlength >= ~(size_t)0 / sizeof(jschar)) {
+        js_ReportAllocationOverflow(cx);
+        return false;
+    }
+
+    jschar *newchars = cx->pod_malloc<jschar>(newlength + 1);
+    if (!newchars)
+        return false;
+    size_t i, ni;
+    for (i = 0, ni = 0; i < length; i++) {
+        jschar ch = chars[i];
+        if (ch < 128 && shouldPassThrough[ch]) {
+            newchars[ni++] = ch;
+        } else if (ch < 256) {
+            newchars[ni++] = '%';
+            newchars[ni++] = digits[ch >> 4];
+            newchars[ni++] = digits[ch & 0xF];
+        } else {
+            newchars[ni++] = '%';
+            newchars[ni++] = 'u';
+            newchars[ni++] = digits[ch >> 12];
+            newchars[ni++] = digits[(ch & 0xF00) >> 8];
+            newchars[ni++] = digits[(ch & 0xF0) >> 4];
+            newchars[ni++] = digits[ch & 0xF];
+        }
+    }
+    JS_ASSERT(ni == newlength);
+    newchars[newlength] = 0;
+
+    JSString *retstr = js_NewString<CanGC>(cx, newchars, newlength);
+    if (!retstr) {
+        js_free(newchars);
+        return false;
+    }
+
+    args.rval().setString(retstr);
+    return true;
+}
+
+static inline bool
+Unhex4(const jschar *chars, jschar *result)
+{
+    jschar a = chars[0],
+           b = chars[1],
+           c = chars[2],
+           d = chars[3];
+
+    if (!(JS7_ISHEX(a) && JS7_ISHEX(b) && JS7_ISHEX(c) && JS7_ISHEX(d)))
+        return false;
+
+    *result = (((((JS7_UNHEX(a) << 4) + JS7_UNHEX(b)) << 4) + JS7_UNHEX(c)) << 4) + JS7_UNHEX(d);
+    return true;
+}
+
+static inline bool
+Unhex2(const jschar *chars, jschar *result)
+{
+    jschar a = chars[0],
+           b = chars[1];
+
+    if (!(JS7_ISHEX(a) && JS7_ISHEX(b)))
+        return false;
+
+    *result = (JS7_UNHEX(a) << 4) + JS7_UNHEX(b);
+    return true;
+}
+
+/* ES5 B.2.2 */
+static bool
+str_unescape(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /* Step 1. */
+    JSLinearString *str = ArgToRootedString(cx, args, 0);
+    if (!str)
+        return false;
+
+    /*
+     * NB: use signed integers for length/index to allow simple length
+     * comparisons without unsigned-underflow hazards.
+     */
+    JS_STATIC_ASSERT(JSString::MAX_LENGTH <= INT_MAX);
+
+    /* Step 2. */
+    int length = str->length();
+    const jschar *chars = str->chars();
+
+    /* Step 3. */
+    StringBuffer sb(cx);
+
+    /*
+     * Note that the spec algorithm has been optimized to avoid building
+     * a string in the case where no escapes are present.
+     */
+
+    /* Step 4. */
+    int k = 0;
+    bool building = false;
+
+    while (true) {
+        /* Step 5. */
+        if (k == length) {
+            JSLinearString *result;
+            if (building) {
+                result = sb.finishString();
+                if (!result)
+                    return false;
+            } else {
+                result = str;
+            }
+
+            args.rval().setString(result);
+            return true;
+        }
+
+        /* Step 6. */
+        jschar c = chars[k];
+
+        /* Step 7. */
+        if (c != '%')
+            goto step_18;
+
+        /* Step 8. */
+        if (k > length - 6)
+            goto step_14;
+
+        /* Step 9. */
+        if (chars[k + 1] != 'u')
+            goto step_14;
+
+#define ENSURE_BUILDING                             \
+    JS_BEGIN_MACRO                                  \
+        if (!building) {                            \
+            building = true;                        \
+            if (!sb.reserve(length))                \
+                return false;                       \
+            sb.infallibleAppend(chars, chars + k);  \
+        }                                           \
+    JS_END_MACRO
+
+        /* Step 10-13. */
+        if (Unhex4(&chars[k + 2], &c)) {
+            ENSURE_BUILDING;
+            k += 5;
+            goto step_18;
+        }
+
+      step_14:
+        /* Step 14. */
+        if (k > length - 3)
+            goto step_18;
+
+        /* Step 15-17. */
+        if (Unhex2(&chars[k + 1], &c)) {
+            ENSURE_BUILDING;
+            k += 2;
+        }
+
+      step_18:
+        if (building)
+            sb.infallibleAppend(c);
+
+        /* Step 19. */
+        k += 1;
+    }
+#undef ENSURE_BUILDING
+}
+
+#if JS_HAS_UNEVAL
+static bool
+str_uneval(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    JSString *str = ValueToSource(cx, args.get(0));
+    if (!str)
+        return false;
+
+    args.rval().setString(str);
+    return true;
+}
+#endif
+
+static const JSFunctionSpec string_functions[] = {
+    JS_FN(js_escape_str,             str_escape,                1,0),
+    JS_FN(js_unescape_str,           str_unescape,              1,0),
+#if JS_HAS_UNEVAL
+    JS_FN(js_uneval_str,             str_uneval,                1,0),
+#endif
+    JS_FN(js_decodeURI_str,          str_decodeURI,             1,0),
+    JS_FN(js_encodeURI_str,          str_encodeURI,             1,0),
+    JS_FN(js_decodeURIComponent_str, str_decodeURI_Component,   1,0),
+    JS_FN(js_encodeURIComponent_str, str_encodeURI_Component,   1,0),
+
+    JS_FS_END
+};
+
+const jschar      js_empty_ucstr[]  = {0};
+const JSSubString js_EmptySubString = {0, js_empty_ucstr};
+
+static const unsigned STRING_ELEMENT_ATTRS = JSPROP_ENUMERATE | JSPROP_READONLY | JSPROP_PERMANENT;
+
+static bool
+str_enumerate(JSContext *cx, HandleObject obj)
+{
+    RootedString str(cx, obj->as<StringObject>().unbox());
+    RootedValue value(cx);
+    for (size_t i = 0, length = str->length(); i < length; i++) {
+        JSString *str1 = js_NewDependentString(cx, str, i, 1);
+        if (!str1)
+            return false;
+        value.setString(str1);
+        if (!JSObject::defineElement(cx, obj, i, value,
+                                     JS_PropertyStub, JS_StrictPropertyStub,
+                                     STRING_ELEMENT_ATTRS))
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool
+js::str_resolve(JSContext *cx, HandleObject obj, HandleId id, MutableHandleObject objp)
+{
+    if (!JSID_IS_INT(id))
+        return true;
+
+    RootedString str(cx, obj->as<StringObject>().unbox());
+
+    int32_t slot = JSID_TO_INT(id);
+    if ((size_t)slot < str->length()) {
+        JSString *str1 = cx->staticStrings().getUnitStringForElement(cx, str, size_t(slot));
+        if (!str1)
+            return false;
+        RootedValue value(cx, StringValue(str1));
+        if (!JSObject::defineElement(cx, obj, uint32_t(slot), value, nullptr, nullptr,
+                                     STRING_ELEMENT_ATTRS))
+        {
+            return false;
+        }
+        objp.set(obj);
+    }
+    return true;
+}
+
+const Class StringObject::class_ = {
+    js_String_str,
+    JSCLASS_HAS_RESERVED_SLOTS(StringObject::RESERVED_SLOTS) |
+    JSCLASS_NEW_RESOLVE | JSCLASS_HAS_CACHED_PROTO(JSProto_String),
+    JS_PropertyStub,         /* addProperty */
+    JS_DeletePropertyStub,   /* delProperty */
+    JS_PropertyStub,         /* getProperty */
+    JS_StrictPropertyStub,   /* setProperty */
+    str_enumerate,
+    (JSResolveOp)str_resolve,
+    JS_ConvertStub
+};
+
+/*
+ * Returns a JSString * for the |this| value associated with 'call', or throws
+ * a TypeError if |this| is null or undefined.  This algorithm is the same as
+ * calling CheckObjectCoercible(this), then returning ToString(this), as all
+ * String.prototype.* methods do (other than toString and valueOf).
+ */
+static MOZ_ALWAYS_INLINE JSString *
+ThisToStringForStringProto(JSContext *cx, CallReceiver call)
+{
+    JS_CHECK_RECURSION(cx, return nullptr);
+
+    if (call.thisv().isString())
+        return call.thisv().toString();
+
+    if (call.thisv().isObject()) {
+        RootedObject obj(cx, &call.thisv().toObject());
+        if (obj->is<StringObject>()) {
+            Rooted<jsid> id(cx, NameToId(cx->names().toString));
+            if (ClassMethodIsNative(cx, obj, &StringObject::class_, id, js_str_toString)) {
+                JSString *str = obj->as<StringObject>().unbox();
+                call.setThis(StringValue(str));
+                return str;
+            }
+        }
+    } else if (call.thisv().isNullOrUndefined()) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_CANT_CONVERT_TO,
+                             call.thisv().isNull() ? "null" : "undefined", "object");
+        return nullptr;
+    }
+
+    JSString *str = ToStringSlow<CanGC>(cx, call.thisv());
+    if (!str)
+        return nullptr;
+
+    call.setThis(StringValue(str));
+    return str;
+}
+
+MOZ_ALWAYS_INLINE bool
+IsString(HandleValue v)
+{
+    return v.isString() || (v.isObject() && v.toObject().is<StringObject>());
+}
+
+#if JS_HAS_TOSOURCE
+
+/*
+ * String.prototype.quote is generic (as are most string methods), unlike
+ * toSource, toString, and valueOf.
+ */
+static bool
+str_quote(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+    str = js_QuoteString(cx, str, '"');
+    if (!str)
+        return false;
+    args.rval().setString(str);
+    return true;
+}
+
+MOZ_ALWAYS_INLINE bool
+str_toSource_impl(JSContext *cx, CallArgs args)
+{
+    JS_ASSERT(IsString(args.thisv()));
+
+    Rooted<JSString*> str(cx, ToString<CanGC>(cx, args.thisv()));
+    if (!str)
+        return false;
+
+    str = js_QuoteString(cx, str, '"');
+    if (!str)
+        return false;
+
+    StringBuffer sb(cx);
+    if (!sb.append("(new String(") || !sb.append(str) || !sb.append("))"))
+        return false;
+
+    str = sb.finishString();
+    if (!str)
+        return false;
+    args.rval().setString(str);
+    return true;
+}
+
+static bool
+str_toSource(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsString, str_toSource_impl>(cx, args);
+}
+
+#endif /* JS_HAS_TOSOURCE */
+
+MOZ_ALWAYS_INLINE bool
+str_toString_impl(JSContext *cx, CallArgs args)
+{
+    JS_ASSERT(IsString(args.thisv()));
+
+    args.rval().setString(args.thisv().isString()
+                              ? args.thisv().toString()
+                              : args.thisv().toObject().as<StringObject>().unbox());
+    return true;
+}
+
+bool
+js_str_toString(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsString, str_toString_impl>(cx, args);
+}
+
+/*
+ * Java-like string native methods.
+ */
+
+static MOZ_ALWAYS_INLINE bool
+ValueToIntegerRange(JSContext *cx, HandleValue v, int32_t *out)
+{
+    if (v.isInt32()) {
+        *out = v.toInt32();
+    } else {
+        double d;
+        if (!ToInteger(cx, v, &d))
+            return false;
+        if (d > INT32_MAX)
+            *out = INT32_MAX;
+        else if (d < INT32_MIN)
+            *out = INT32_MIN;
+        else
+            *out = int32_t(d);
+    }
+
+    return true;
+}
+
+static JSString *
+DoSubstr(JSContext *cx, JSString *str, size_t begin, size_t len)
+{
+    /*
+     * Optimization for one level deep ropes.
+     * This is common for the following pattern:
+     *
+     * while() {
+     *   text = text.substr(0, x) + "bla" + text.substr(x)
+     *   test.charCodeAt(x + 1)
+     * }
+     */
+    if (str->isRope()) {
+        JSRope *rope = &str->asRope();
+
+        /* Substring is totally in leftChild of rope. */
+        if (begin + len <= rope->leftChild()->length()) {
+            str = rope->leftChild();
+            return js_NewDependentString(cx, str, begin, len);
+        }
+
+        /* Substring is totally in rightChild of rope. */
+        if (begin >= rope->leftChild()->length()) {
+            str = rope->rightChild();
+            begin -= rope->leftChild()->length();
+            return js_NewDependentString(cx, str, begin, len);
+        }
+
+        /*
+         * Requested substring is partly in the left and partly in right child.
+         * Create a rope of substrings for both childs.
+         */
+        JS_ASSERT (begin < rope->leftChild()->length() &&
+                   begin + len > rope->leftChild()->length());
+
+        size_t lhsLength = rope->leftChild()->length() - begin;
+        size_t rhsLength = begin + len - rope->leftChild()->length();
+
+        Rooted<JSRope *> ropeRoot(cx, rope);
+        RootedString lhs(cx, js_NewDependentString(cx, ropeRoot->leftChild(),
+                                                   begin, lhsLength));
+        if (!lhs)
+            return nullptr;
+
+        RootedString rhs(cx, js_NewDependentString(cx, ropeRoot->rightChild(), 0, rhsLength));
+        if (!rhs)
+            return nullptr;
+
+        return JSRope::new_<CanGC>(cx, lhs, rhs, len);
+    }
+
+    return js_NewDependentString(cx, str, begin, len);
+}
+
+static bool
+str_substring(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    JSString *str = ThisToStringForStringProto(cx, args);
+    if (!str)
+        return false;
+
+    int32_t length, begin, end;
+    if (args.length() > 0) {
+        end = length = int32_t(str->length());
+
+        if (args[0].isInt32()) {
+            begin = args[0].toInt32();
+        } else {
+            RootedString strRoot(cx, str);
+            if (!ValueToIntegerRange(cx, args[0], &begin))
+                return false;
+            str = strRoot;
+        }
+
+        if (begin < 0)
+            begin = 0;
+        else if (begin > length)
+            begin = length;
+
+        if (args.hasDefined(1)) {
+            if (args[1].isInt32()) {
+                end = args[1].toInt32();
+            } else {
+                RootedString strRoot(cx, str);
+                if (!ValueToIntegerRange(cx, args[1], &end))
+                    return false;
+                str = strRoot;
+            }
+
+            if (end > length) {
+                end = length;
+            } else {
+                if (end < 0)
+                    end = 0;
+                if (end < begin) {
+                    int32_t tmp = begin;
+                    begin = end;
+                    end = tmp;
+                }
+            }
+        }
+
+        str = DoSubstr(cx, str, size_t(begin), size_t(end - begin));
+        if (!str)
+            return false;
+    }
+
+    args.rval().setString(str);
+    return true;
+}
+
+JSString* JS_FASTCALL
+js_toLowerCase(JSContext *cx, JSString *str)
+{
+    size_t n = str->length();
+    const jschar *s = str->getChars(cx);
+    if (!s)
+        return nullptr;
+
+    jschar *news = cx->pod_malloc<jschar>(n + 1);
+    if (!news)
+        return nullptr;
+    for (size_t i = 0; i < n; i++)
+        news[i] = unicode::ToLowerCase(s[i]);
+    news[n] = 0;
+    str = js_NewString<CanGC>(cx, news, n);
+    if (!str) {
+        js_free(news);
+        return nullptr;
+    }
+    return str;
+}
+
+static inline bool
+ToLowerCaseHelper(JSContext *cx, CallReceiver call)
+{
+    RootedString str(cx, ThisToStringForStringProto(cx, call));
+    if (!str)
+        return false;
+
+    str = js_toLowerCase(cx, str);
+    if (!str)
+        return false;
+
+    call.rval().setString(str);
+    return true;
+}
+
+static bool
+str_toLowerCase(JSContext *cx, unsigned argc, Value *vp)
+{
+    return ToLowerCaseHelper(cx, CallArgsFromVp(argc, vp));
+}
+
+static bool
+str_toLocaleLowerCase(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /*
+     * Forcefully ignore the first (or any) argument and return toLowerCase(),
+     * ECMA has reserved that argument, presumably for defining the locale.
+     */
+    if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeToLowerCase) {
+        RootedString str(cx, ThisToStringForStringProto(cx, args));
+        if (!str)
+            return false;
+
+        RootedValue result(cx);
+        if (!cx->runtime()->localeCallbacks->localeToLowerCase(cx, str, &result))
+            return false;
+
+        args.rval().set(result);
+        return true;
+    }
+
+    return ToLowerCaseHelper(cx, args);
+}
+
+JSString* JS_FASTCALL
+js_toUpperCase(JSContext *cx, JSString *str)
+{
+    size_t n = str->length();
+    const jschar *s = str->getChars(cx);
+    if (!s)
+        return nullptr;
+    jschar *news = cx->pod_malloc<jschar>(n + 1);
+    if (!news)
+        return nullptr;
+    for (size_t i = 0; i < n; i++)
+        news[i] = unicode::ToUpperCase(s[i]);
+    news[n] = 0;
+    str = js_NewString<CanGC>(cx, news, n);
+    if (!str) {
+        js_free(news);
+        return nullptr;
+    }
+    return str;
+}
+
+static bool
+ToUpperCaseHelper(JSContext *cx, CallReceiver call)
+{
+    RootedString str(cx, ThisToStringForStringProto(cx, call));
+    if (!str)
+        return false;
+
+    str = js_toUpperCase(cx, str);
+    if (!str)
+        return false;
+
+    call.rval().setString(str);
+    return true;
+}
+
+static bool
+str_toUpperCase(JSContext *cx, unsigned argc, Value *vp)
+{
+    return ToUpperCaseHelper(cx, CallArgsFromVp(argc, vp));
+}
+
+static bool
+str_toLocaleUpperCase(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /*
+     * Forcefully ignore the first (or any) argument and return toUpperCase(),
+     * ECMA has reserved that argument, presumably for defining the locale.
+     */
+    if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeToUpperCase) {
+        RootedString str(cx, ThisToStringForStringProto(cx, args));
+        if (!str)
+            return false;
+
+        RootedValue result(cx);
+        if (!cx->runtime()->localeCallbacks->localeToUpperCase(cx, str, &result))
+            return false;
+
+        args.rval().set(result);
+        return true;
+    }
+
+    return ToUpperCaseHelper(cx, args);
+}
+
+#if !EXPOSE_INTL_API
+static bool
+str_localeCompare(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    RootedString thatStr(cx, ToString<CanGC>(cx, args.get(0)));
+    if (!thatStr)
+        return false;
+
+    if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeCompare) {
+        RootedValue result(cx);
+        if (!cx->runtime()->localeCallbacks->localeCompare(cx, str, thatStr, &result))
+            return false;
+
+        args.rval().set(result);
+        return true;
+    }
+
+    int32_t result;
+    if (!CompareStrings(cx, str, thatStr, &result))
+        return false;
+
+    args.rval().setInt32(result);
+    return true;
+}
+#endif
+
+#if EXPOSE_INTL_API
+static const size_t SB_LENGTH = 32;
+
+/* ES6 20140210 draft 21.1.3.12. */
+static bool
+str_normalize(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // Steps 1-3.
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    // Step 4.
+    UNormalizationMode form;
+    if (!args.hasDefined(0)) {
+        form = UNORM_NFC;
+    } else {
+        // Steps 5-6.
+        Rooted<JSLinearString*> formStr(cx, ArgToRootedString(cx, args, 0));
+        if (!formStr)
+            return false;
+
+        // Step 7.
+        if (formStr == cx->names().NFC) {
+            form = UNORM_NFC;
+        } else if (formStr == cx->names().NFD) {
+            form = UNORM_NFD;
+        } else if (formStr == cx->names().NFKC) {
+            form = UNORM_NFKC;
+        } else if (formStr == cx->names().NFKD) {
+            form = UNORM_NFKD;
+        } else {
+            JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr,
+                                 JSMSG_INVALID_NORMALIZE_FORM);
+            return false;
+        }
+    }
+
+    // Step 8.
+    Rooted<JSFlatString*> flatStr(cx, str->ensureFlat(cx));
+    if (!flatStr)
+        return false;
+    const UChar *srcChars = JSCharToUChar(flatStr->chars());
+    int32_t srcLen = SafeCast<int32_t>(flatStr->length());
+    StringBuffer chars(cx);
+    if (!chars.resize(SB_LENGTH))
+        return false;
+    UErrorCode status = U_ZERO_ERROR;
+    int32_t size = unorm_normalize(srcChars, srcLen, form, 0,
+                                   JSCharToUChar(chars.begin()), SB_LENGTH,
+                                   &status);
+    if (status == U_BUFFER_OVERFLOW_ERROR) {
+        if (!chars.resize(size))
+            return false;
+        status = U_ZERO_ERROR;
+#ifdef DEBUG
+        int32_t finalSize =
+#endif
+        unorm_normalize(srcChars, srcLen, form, 0,
+                        JSCharToUChar(chars.begin()), size,
+                        &status);
+        MOZ_ASSERT(size == finalSize || U_FAILURE(status), "unorm_normalize behaved inconsistently");
+    }
+    if (U_FAILURE(status))
+        return false;
+    // Trim any unused characters.
+    if (!chars.resize(size))
+        return false;
+    RootedString ns(cx, chars.finishString());
+    if (!ns)
+        return false;
+
+    // Step 9.
+    args.rval().setString(ns);
+    return true;
+}
+#endif
+
+bool
+js_str_charAt(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    RootedString str(cx);
+    size_t i;
+    if (args.thisv().isString() && args.length() != 0 && args[0].isInt32()) {
+        str = args.thisv().toString();
+        i = size_t(args[0].toInt32());
+        if (i >= str->length())
+            goto out_of_range;
+    } else {
+        str = ThisToStringForStringProto(cx, args);
+        if (!str)
+            return false;
+
+        double d = 0.0;
+        if (args.length() > 0 && !ToInteger(cx, args[0], &d))
+            return false;
+
+        if (d < 0 || str->length() <= d)
+            goto out_of_range;
+        i = size_t(d);
+    }
+
+    str = cx->staticStrings().getUnitStringForElement(cx, str, i);
+    if (!str)
+        return false;
+    args.rval().setString(str);
+    return true;
+
+  out_of_range:
+    args.rval().setString(cx->runtime()->emptyString);
+    return true;
+}
+
+bool
+js_str_charCodeAt(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    RootedString str(cx);
+    size_t i;
+    if (args.thisv().isString() && args.length() != 0 && args[0].isInt32()) {
+        str = args.thisv().toString();
+        i = size_t(args[0].toInt32());
+        if (i >= str->length())
+            goto out_of_range;
+    } else {
+        str = ThisToStringForStringProto(cx, args);
+        if (!str)
+            return false;
+
+        double d = 0.0;
+        if (args.length() > 0 && !ToInteger(cx, args[0], &d))
+            return false;
+
+        if (d < 0 || str->length() <= d)
+            goto out_of_range;
+        i = size_t(d);
+    }
+
+    jschar c;
+    if (!str->getChar(cx, i, &c))
+        return false;
+    args.rval().setInt32(c);
+    return true;
+
+out_of_range:
+    args.rval().setNaN();
+    return true;
+}
+
+/*
+ * Boyer-Moore-Horspool superlinear search for pat:patlen in text:textlen.
+ * The patlen argument must be positive and no greater than sBMHPatLenMax.
+ *
+ * Return the index of pat in text, or -1 if not found.
+ */
+static const uint32_t sBMHCharSetSize = 256; /* ISO-Latin-1 */
+static const uint32_t sBMHPatLenMax   = 255; /* skip table element is uint8_t */
+static const int      sBMHBadPattern  = -2;  /* return value if pat is not ISO-Latin-1 */
+
+int
+js_BoyerMooreHorspool(const jschar *text, uint32_t textlen,
+                      const jschar *pat, uint32_t patlen)
+{
+    uint8_t skip[sBMHCharSetSize];
+
+    JS_ASSERT(0 < patlen && patlen <= sBMHPatLenMax);
+    for (uint32_t i = 0; i < sBMHCharSetSize; i++)
+        skip[i] = (uint8_t)patlen;
+    uint32_t m = patlen - 1;
+    for (uint32_t i = 0; i < m; i++) {
+        jschar c = pat[i];
+        if (c >= sBMHCharSetSize)
+            return sBMHBadPattern;
+        skip[c] = (uint8_t)(m - i);
+    }
+    jschar c;
+    for (uint32_t k = m;
+         k < textlen;
+         k += ((c = text[k]) >= sBMHCharSetSize) ? patlen : skip[c]) {
+        for (uint32_t i = k, j = m; ; i--, j--) {
+            if (text[i] != pat[j])
+                break;
+            if (j == 0)
+                return static_cast<int>(i);  /* safe: max string size */
+        }
+    }
+    return -1;
+}
+
+struct MemCmp {
+    typedef uint32_t Extent;
+    static MOZ_ALWAYS_INLINE Extent computeExtent(const jschar *, uint32_t patlen) {
+        return (patlen - 1) * sizeof(jschar);
+    }
+    static MOZ_ALWAYS_INLINE bool match(const jschar *p, const jschar *t, Extent extent) {
+        return memcmp(p, t, extent) == 0;
+    }
+};
+
+struct ManualCmp {
+    typedef const jschar *Extent;
+    static MOZ_ALWAYS_INLINE Extent computeExtent(const jschar *pat, uint32_t patlen) {
+        return pat + patlen;
+    }
+    static MOZ_ALWAYS_INLINE bool match(const jschar *p, const jschar *t, Extent extent) {
+        for (; p != extent; ++p, ++t) {
+            if (*p != *t)
+                return false;
+        }
+        return true;
+    }
+};
+
+template <class InnerMatch>
+static int
+UnrolledMatch(const jschar *text, uint32_t textlen, const jschar *pat, uint32_t patlen)
+{
+    JS_ASSERT(patlen > 0 && textlen > 0);
+    const jschar *textend = text + textlen - (patlen - 1);
+    const jschar p0 = *pat;
+    const jschar *const patNext = pat + 1;
+    const typename InnerMatch::Extent extent = InnerMatch::computeExtent(pat, patlen);
+    uint8_t fixup;
+
+    const jschar *t = text;
+    switch ((textend - t) & 7) {
+      case 0: if (*t++ == p0) { fixup = 8; goto match; }
+      case 7: if (*t++ == p0) { fixup = 7; goto match; }
+      case 6: if (*t++ == p0) { fixup = 6; goto match; }
+      case 5: if (*t++ == p0) { fixup = 5; goto match; }
+      case 4: if (*t++ == p0) { fixup = 4; goto match; }
+      case 3: if (*t++ == p0) { fixup = 3; goto match; }
+      case 2: if (*t++ == p0) { fixup = 2; goto match; }
+      case 1: if (*t++ == p0) { fixup = 1; goto match; }
+    }
+    while (t != textend) {
+      if (t[0] == p0) { t += 1; fixup = 8; goto match; }
+      if (t[1] == p0) { t += 2; fixup = 7; goto match; }
+      if (t[2] == p0) { t += 3; fixup = 6; goto match; }
+      if (t[3] == p0) { t += 4; fixup = 5; goto match; }
+      if (t[4] == p0) { t += 5; fixup = 4; goto match; }
+      if (t[5] == p0) { t += 6; fixup = 3; goto match; }
+      if (t[6] == p0) { t += 7; fixup = 2; goto match; }
+      if (t[7] == p0) { t += 8; fixup = 1; goto match; }
+        t += 8;
+        continue;
+        do {
+            if (*t++ == p0) {
+              match:
+                if (!InnerMatch::match(patNext, t, extent))
+                    goto failed_match;
+                return t - text - 1;
+            }
+          failed_match:;
+        } while (--fixup > 0);
+    }
+    return -1;
+}
+
+static MOZ_ALWAYS_INLINE int
+StringMatch(const jschar *text, uint32_t textlen,
+            const jschar *pat, uint32_t patlen)
+{
+    if (patlen == 0)
+        return 0;
+    if (textlen < patlen)
+        return -1;
+
+#if defined(__i386__) || defined(_M_IX86) || defined(__i386)
+    /*
+     * Given enough registers, the unrolled loop below is faster than the
+     * following loop. 32-bit x86 does not have enough registers.
+     */
+    if (patlen == 1) {
+        const jschar p0 = *pat;
+        for (const jschar *c = text, *end = text + textlen; c != end; ++c) {
+            if (*c == p0)
+                return c - text;
+        }
+        return -1;
+    }
+#endif
+
+    /*
+     * If the text or pattern string is short, BMH will be more expensive than
+     * the basic linear scan due to initialization cost and a more complex loop
+     * body. While the correct threshold is input-dependent, we can make a few
+     * conservative observations:
+     *  - When |textlen| is "big enough", the initialization time will be
+     *    proportionally small, so the worst-case slowdown is minimized.
+     *  - When |patlen| is "too small", even the best case for BMH will be
+     *    slower than a simple scan for large |textlen| due to the more complex
+     *    loop body of BMH.
+     * From this, the values for "big enough" and "too small" are determined
+     * empirically. See bug 526348.
+     */
+    if (textlen >= 512 && patlen >= 11 && patlen <= sBMHPatLenMax) {
+        int index = js_BoyerMooreHorspool(text, textlen, pat, patlen);
+        if (index != sBMHBadPattern)
+            return index;
+    }
+
+    /*
+     * For big patterns with large potential overlap we want the SIMD-optimized
+     * speed of memcmp. For small patterns, a simple loop is faster.
+     *
+     * FIXME: Linux memcmp performance is sad and the manual loop is faster.
+     */
+    return
+#if !defined(__linux__)
+           patlen > 128 ? UnrolledMatch<MemCmp>(text, textlen, pat, patlen)
+                        :
+#endif
+                          UnrolledMatch<ManualCmp>(text, textlen, pat, patlen);
+}
+
+static const size_t sRopeMatchThresholdRatioLog2 = 5;
+
+bool
+js::StringHasPattern(const jschar *text, uint32_t textlen,
+                     const jschar *pat, uint32_t patlen)
+{
+    return StringMatch(text, textlen, pat, patlen) != -1;
+}
+
+// When an algorithm does not need a string represented as a single linear
+// array of characters, this range utility may be used to traverse the string a
+// sequence of linear arrays of characters. This avoids flattening ropes.
+class StringSegmentRange
+{
+    // If malloc() shows up in any profiles from this vector, we can add a new
+    // StackAllocPolicy which stashes a reusable freed-at-gc buffer in the cx.
+    AutoStringVector stack;
+    Rooted<JSLinearString*> cur;
+
+    bool settle(JSString *str) {
+        while (str->isRope()) {
+            JSRope &rope = str->asRope();
+            if (!stack.append(rope.rightChild()))
+                return false;
+            str = rope.leftChild();
+        }
+        cur = &str->asLinear();
+        return true;
+    }
+
+  public:
+    StringSegmentRange(JSContext *cx)
+      : stack(cx), cur(cx)
+    {}
+
+    MOZ_WARN_UNUSED_RESULT bool init(JSString *str) {
+        JS_ASSERT(stack.empty());
+        return settle(str);
+    }
+
+    bool empty() const {
+        return cur == nullptr;
+    }
+
+    JSLinearString *front() const {
+        JS_ASSERT(!cur->isRope());
+        return cur;
+    }
+
+    MOZ_WARN_UNUSED_RESULT bool popFront() {
+        JS_ASSERT(!empty());
+        if (stack.empty()) {
+            cur = nullptr;
+            return true;
+        }
+        return settle(stack.popCopy());
+    }
+};
+
+/*
+ * RopeMatch takes the text to search and the pattern to search for in the text.
+ * RopeMatch returns false on OOM and otherwise returns the match index through
+ * the 'match' outparam (-1 for not found).
+ */
+static bool
+RopeMatch(JSContext *cx, JSString *textstr, const jschar *pat, uint32_t patlen, int *match)
+{
+    JS_ASSERT(textstr->isRope());
+
+    if (patlen == 0) {
+        *match = 0;
+        return true;
+    }
+    if (textstr->length() < patlen) {
+        *match = -1;
+        return true;
+    }
+
+    /*
+     * List of leaf nodes in the rope. If we run out of memory when trying to
+     * append to this list, we can still fall back to StringMatch, so use the
+     * system allocator so we don't report OOM in that case.
+     */
+    Vector<JSLinearString *, 16, SystemAllocPolicy> strs;
+
+    /*
+     * We don't want to do rope matching if there is a poor node-to-char ratio,
+     * since this means spending a lot of time in the match loop below. We also
+     * need to build the list of leaf nodes. Do both here: iterate over the
+     * nodes so long as there are not too many.
+     */
+    {
+        size_t textstrlen = textstr->length();
+        size_t threshold = textstrlen >> sRopeMatchThresholdRatioLog2;
+        StringSegmentRange r(cx);
+        if (!r.init(textstr))
+            return false;
+        while (!r.empty()) {
+            if (threshold-- == 0 || !strs.append(r.front())) {
+                const jschar *chars = textstr->getChars(cx);
+                if (!chars)
+                    return false;
+                *match = StringMatch(chars, textstrlen, pat, patlen);
+                return true;
+            }
+            if (!r.popFront())
+                return false;
+        }
+    }
+
+    /* Absolute offset from the beginning of the logical string textstr. */
+    int pos = 0;
+
+    for (JSLinearString **outerp = strs.begin(); outerp != strs.end(); ++outerp) {
+        /* Try to find a match within 'outer'. */
+        JSLinearString *outer = *outerp;
+        const jschar *chars = outer->chars();
+        size_t len = outer->length();
+        int matchResult = StringMatch(chars, len, pat, patlen);
+        if (matchResult != -1) {
+            /* Matched! */
+            *match = pos + matchResult;
+            return true;
+        }
+
+        /* Try to find a match starting in 'outer' and running into other nodes. */
+        const jschar *const text = chars + (patlen > len ? 0 : len - patlen + 1);
+        const jschar *const textend = chars + len;
+        const jschar p0 = *pat;
+        const jschar *const p1 = pat + 1;
+        const jschar *const patend = pat + patlen;
+        for (const jschar *t = text; t != textend; ) {
+            if (*t++ != p0)
+                continue;
+            JSLinearString **innerp = outerp;
+            const jschar *ttend = textend;
+            for (const jschar *pp = p1, *tt = t; pp != patend; ++pp, ++tt) {
+                while (tt == ttend) {
+                    if (++innerp == strs.end()) {
+                        *match = -1;
+                        return true;
+                    }
+                    JSLinearString *inner = *innerp;
+                    tt = inner->chars();
+                    ttend = tt + inner->length();
+                }
+                if (*pp != *tt)
+                    goto break_continue;
+            }
+
+            /* Matched! */
+            *match = pos + (t - chars) - 1;  /* -1 because of *t++ above */
+            return true;
+
+          break_continue:;
+        }
+
+        pos += len;
+    }
+
+    *match = -1;
+    return true;
+}
+
+/* ES6 20121026 draft 15.5.4.24. */
+static bool
+str_contains(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // Steps 1, 2, and 3
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    // Steps 4 and 5
+    Rooted<JSLinearString*> searchStr(cx, ArgToRootedString(cx, args, 0));
+    if (!searchStr)
+        return false;
+
+    // Steps 6 and 7
+    uint32_t pos = 0;
+    if (args.hasDefined(1)) {
+        if (args[1].isInt32()) {
+            int i = args[1].toInt32();
+            pos = (i < 0) ? 0U : uint32_t(i);
+        } else {
+            double d;
+            if (!ToInteger(cx, args[1], &d))
+                return false;
+            pos = uint32_t(Min(Max(d, 0.0), double(UINT32_MAX)));
+        }
+    }
+
+    // Step 8
+    uint32_t textLen = str->length();
+    const jschar *textChars = str->getChars(cx);
+    if (!textChars)
+        return false;
+
+    // Step 9
+    uint32_t start = Min(Max(pos, 0U), textLen);
+
+    // Step 10
+    uint32_t searchLen = searchStr->length();
+    const jschar *searchChars = searchStr->chars();
+
+    // Step 11
+    textChars += start;
+    textLen -= start;
+    int match = StringMatch(textChars, textLen, searchChars, searchLen);
+    args.rval().setBoolean(match != -1);
+    return true;
+}
+
+/* ES6 20120927 draft 15.5.4.7. */
+static bool
+str_indexOf(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // Steps 1, 2, and 3
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    // Steps 4 and 5
+    Rooted<JSLinearString*> searchStr(cx, ArgToRootedString(cx, args, 0));
+    if (!searchStr)
+        return false;
+
+    // Steps 6 and 7
+    uint32_t pos = 0;
+    if (args.hasDefined(1)) {
+        if (args[1].isInt32()) {
+            int i = args[1].toInt32();
+            pos = (i < 0) ? 0U : uint32_t(i);
+        } else {
+            double d;
+            if (!ToInteger(cx, args[1], &d))
+                return false;
+            pos = uint32_t(Min(Max(d, 0.0), double(UINT32_MAX)));
+        }
+    }
+
+   // Step 8
+    uint32_t textLen = str->length();
+    const jschar *textChars = str->getChars(cx);
+    if (!textChars)
+        return false;
+
+    // Step 9
+    uint32_t start = Min(Max(pos, 0U), textLen);
+
+    // Step 10
+    uint32_t searchLen = searchStr->length();
+    const jschar *searchChars = searchStr->chars();
+
+    // Step 11
+    textChars += start;
+    textLen -= start;
+    int match = StringMatch(textChars, textLen, searchChars, searchLen);
+    args.rval().setInt32((match == -1) ? -1 : start + match);
+    return true;
+}
+
+static bool
+str_lastIndexOf(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedString textstr(cx, ThisToStringForStringProto(cx, args));
+    if (!textstr)
+        return false;
+
+    size_t textlen = textstr->length();
+
+    Rooted<JSLinearString*> patstr(cx, ArgToRootedString(cx, args, 0));
+    if (!patstr)
+        return false;
+
+    size_t patlen = patstr->length();
+
+    int i = textlen - patlen; // Start searching here
+    if (i < 0) {
+        args.rval().setInt32(-1);
+        return true;
+    }
+
+    if (args.length() > 1) {
+        if (args[1].isInt32()) {
+            int j = args[1].toInt32();
+            if (j <= 0)
+                i = 0;
+            else if (j < i)
+                i = j;
+        } else {
+            double d;
+            if (!ToNumber(cx, args[1], &d))
+                return false;
+            if (!IsNaN(d)) {
+                d = ToInteger(d);
+                if (d <= 0)
+                    i = 0;
+                else if (d < i)
+                    i = (int)d;
+            }
+        }
+    }
+
+    if (patlen == 0) {
+        args.rval().setInt32(i);
+        return true;
+    }
+
+    const jschar *text = textstr->getChars(cx);
+    if (!text)
+        return false;
+
+    const jschar *pat = patstr->chars();
+
+    const jschar *t = text + i;
+    const jschar *textend = text - 1;
+    const jschar p0 = *pat;
+    const jschar *patNext = pat + 1;
+    const jschar *patEnd = pat + patlen;
+
+    for (; t != textend; --t) {
+        if (*t == p0) {
+            const jschar *t1 = t + 1;
+            for (const jschar *p1 = patNext; p1 != patEnd; ++p1, ++t1) {
+                if (*t1 != *p1)
+                    goto break_continue;
+            }
+            args.rval().setInt32(t - text);
+            return true;
+        }
+      break_continue:;
+    }
+
+    args.rval().setInt32(-1);
+    return true;
+}
+
+/* ES6 20131108 draft 21.1.3.18. */
+static bool
+str_startsWith(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // Steps 1, 2, and 3
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    // Step 4
+    if (args.get(0).isObject() && IsObjectWithClass(args[0], ESClass_RegExp, cx)) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_INVALID_ARG_TYPE,
+                             "first", "", "Regular Expression");
+        return false;
+    }
+
+    // Steps 5 and 6
+    Rooted<JSLinearString*> searchStr(cx, ArgToRootedString(cx, args, 0));
+    if (!searchStr)
+        return false;
+
+    // Steps 7 and 8
+    uint32_t pos = 0;
+    if (args.hasDefined(1)) {
+        if (args[1].isInt32()) {
+            int i = args[1].toInt32();
+            pos = (i < 0) ? 0U : uint32_t(i);
+        } else {
+            double d;
+            if (!ToInteger(cx, args[1], &d))
+                return false;
+            pos = uint32_t(Min(Max(d, 0.0), double(UINT32_MAX)));
+        }
+    }
+
+    // Step 9
+    uint32_t textLen = str->length();
+    const jschar *textChars = str->getChars(cx);
+    if (!textChars)
+        return false;
+
+    // Step 10
+    uint32_t start = Min(Max(pos, 0U), textLen);
+
+    // Step 11
+    uint32_t searchLen = searchStr->length();
+    const jschar *searchChars = searchStr->chars();
+
+    // Step 12
+    if (searchLen + start < searchLen || searchLen + start > textLen) {
+        args.rval().setBoolean(false);
+        return true;
+    }
+
+    // Steps 13 and 14
+    args.rval().setBoolean(PodEqual(textChars + start, searchChars, searchLen));
+    return true;
+}
+
+/* ES6 20131108 draft 21.1.3.7. */
+static bool
+str_endsWith(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    // Steps 1, 2, and 3
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    // Step 4
+    if (args.get(0).isObject() && IsObjectWithClass(args[0], ESClass_RegExp, cx)) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_INVALID_ARG_TYPE,
+                             "first", "", "Regular Expression");
+        return false;
+    }
+
+    // Steps 5 and 6
+    Rooted<JSLinearString *> searchStr(cx, ArgToRootedString(cx, args, 0));
+    if (!searchStr)
+        return false;
+
+    // Step 7
+    uint32_t textLen = str->length();
+    const jschar *textChars = str->getChars(cx);
+    if (!textChars)
+        return false;
+
+    // Steps 8 and 9
+    uint32_t pos = textLen;
+    if (args.hasDefined(1)) {
+        if (args[1].isInt32()) {
+            int i = args[1].toInt32();
+            pos = (i < 0) ? 0U : uint32_t(i);
+        } else {
+            double d;
+            if (!ToInteger(cx, args[1], &d))
+                return false;
+            pos = uint32_t(Min(Max(d, 0.0), double(UINT32_MAX)));
+        }
+    }
+
+    // Step 10
+    uint32_t end = Min(Max(pos, 0U), textLen);
+
+    // Step 11
+    uint32_t searchLen = searchStr->length();
+    const jschar *searchChars = searchStr->chars();
+
+    // Step 13 (reordered)
+    if (searchLen > end) {
+        args.rval().setBoolean(false);
+        return true;
+    }
+
+    // Step 12
+    uint32_t start = end - searchLen;
+
+    // Steps 14 and 15
+    args.rval().setBoolean(PodEqual(textChars + start, searchChars, searchLen));
+    return true;
+}
+
+static bool
+js_TrimString(JSContext *cx, Value *vp, bool trimLeft, bool trimRight)
+{
+    CallReceiver call = CallReceiverFromVp(vp);
+    RootedString str(cx, ThisToStringForStringProto(cx, call));
+    if (!str)
+        return false;
+    size_t length = str->length();
+    const jschar *chars = str->getChars(cx);
+    if (!chars)
+        return false;
+
+    size_t begin = 0;
+    size_t end = length;
+
+    if (trimLeft) {
+        while (begin < length && unicode::IsSpace(chars[begin]))
+            ++begin;
+    }
+
+    if (trimRight) {
+        while (end > begin && unicode::IsSpace(chars[end - 1]))
+            --end;
+    }
+
+    str = js_NewDependentString(cx, str, begin, end - begin);
+    if (!str)
+        return false;
+
+    call.rval().setString(str);
+    return true;
+}
+
+static bool
+str_trim(JSContext *cx, unsigned argc, Value *vp)
+{
+    return js_TrimString(cx, vp, true, true);
+}
+
+static bool
+str_trimLeft(JSContext *cx, unsigned argc, Value *vp)
+{
+    return js_TrimString(cx, vp, true, false);
+}
+
+static bool
+str_trimRight(JSContext *cx, unsigned argc, Value *vp)
+{
+    return js_TrimString(cx, vp, false, true);
+}
+
+/*
+ * Perl-inspired string functions.
+ */
+
+namespace {
+
+/* Result of a successfully performed flat match. */
+class FlatMatch
+{
+    RootedAtom patstr;
+    const jschar *pat;
+    size_t       patlen;
+    int32_t      match_;
+
+    friend class StringRegExpGuard;
+
+  public:
+    FlatMatch(JSContext *cx) : patstr(cx) {}
+    JSLinearString *pattern() const { return patstr; }
+    size_t patternLength() const { return patlen; }
+
+    /*
+     * Note: The match is -1 when the match is performed successfully,
+     * but no match is found.
+     */
+    int32_t match() const { return match_; }
+};
+
+} /* anonymous namespace */
+
+static inline bool
+IsRegExpMetaChar(jschar c)
+{
+    switch (c) {
+      /* Taken from the PatternCharacter production in 15.10.1. */
+      case '^': case '$': case '\\': case '.': case '*': case '+':
+      case '?': case '(': case ')': case '[': case ']': case '{':
+      case '}': case '|':
+        return true;
+      default:
+        return false;
+    }
+}
+
+static inline bool
+HasRegExpMetaChars(const jschar *chars, size_t length)
+{
+    for (size_t i = 0; i < length; ++i) {
+        if (IsRegExpMetaChar(chars[i]))
+            return true;
+    }
+    return false;
+}
+
+namespace {
+
+/*
+ * StringRegExpGuard factors logic out of String regexp operations.
+ *
+ * |optarg| indicates in which argument position RegExp flags will be found, if
+ * present. This is a Mozilla extension and not part of any ECMA spec.
+ */
+class MOZ_STACK_CLASS StringRegExpGuard
+{
+    RegExpGuard re_;
+    FlatMatch   fm;
+    RootedObject obj_;
+
+    /*
+     * Upper bound on the number of characters we are willing to potentially
+     * waste on searching for RegExp meta-characters.
+     */
+    static const size_t MAX_FLAT_PAT_LEN = 256;
+
+    static JSAtom *
+    flattenPattern(JSContext *cx, JSAtom *patstr)
+    {
+        StringBuffer sb(cx);
+        if (!sb.reserve(patstr->length()))
+            return nullptr;
+
+        static const jschar ESCAPE_CHAR = '\\';
+        const jschar *chars = patstr->chars();
+        size_t len = patstr->length();
+        for (const jschar *it = chars; it != chars + len; ++it) {
+            if (IsRegExpMetaChar(*it)) {
+                if (!sb.append(ESCAPE_CHAR) || !sb.append(*it))
+                    return nullptr;
+            } else {
+                if (!sb.append(*it))
+                    return nullptr;
+            }
+        }
+        return sb.finishAtom();
+    }
+
+  public:
+    StringRegExpGuard(JSContext *cx)
+      : re_(cx), fm(cx), obj_(cx)
+    { }
+
+    /* init must succeed in order to call tryFlatMatch or normalizeRegExp. */
+    bool init(JSContext *cx, CallArgs args, bool convertVoid = false)
+    {
+        if (args.length() != 0 && IsObjectWithClass(args[0], ESClass_RegExp, cx))
+            return init(cx, &args[0].toObject());
+
+        if (convertVoid && !args.hasDefined(0)) {
+            fm.patstr = cx->runtime()->emptyString;
+            return true;
+        }
+
+        JSString *arg = ArgToRootedString(cx, args, 0);
+        if (!arg)
+            return false;
+
+        fm.patstr = AtomizeString(cx, arg);
+        if (!fm.patstr)
+            return false;
+
+        return true;
+    }
+
+    bool init(JSContext *cx, JSObject *regexp) {
+        obj_ = regexp;
+
+        JS_ASSERT(ObjectClassIs(obj_, ESClass_RegExp, cx));
+
+        if (!RegExpToShared(cx, obj_, &re_))
+            return false;
+        return true;
+    }
+
+    bool init(JSContext *cx, HandleString pattern) {
+        fm.patstr = AtomizeString(cx, pattern);
+        if (!fm.patstr)
+            return false;
+        return true;
+    }
+
+    /*
+     * Attempt to match |patstr| to |textstr|. A flags argument, metachars in
+     * the pattern string, or a lengthy pattern string can thwart this process.
+     *
+     * |checkMetaChars| looks for regexp metachars in the pattern string.
+     *
+     * Return whether flat matching could be used.
+     *
+     * N.B. tryFlatMatch returns nullptr on OOM, so the caller must check
+     * cx->isExceptionPending().
+     */
+    const FlatMatch *
+    tryFlatMatch(JSContext *cx, JSString *textstr, unsigned optarg, unsigned argc,
+                 bool checkMetaChars = true)
+    {
+        if (re_.initialized())
+            return nullptr;
+
+        fm.pat = fm.patstr->chars();
+        fm.patlen = fm.patstr->length();
+
+        if (optarg < argc)
+            return nullptr;
+
+        if (checkMetaChars &&
+            (fm.patlen > MAX_FLAT_PAT_LEN || HasRegExpMetaChars(fm.pat, fm.patlen))) {
+            return nullptr;
+        }
+
+        /*
+         * textstr could be a rope, so we want to avoid flattening it for as
+         * long as possible.
+         */
+        if (textstr->isRope()) {
+            if (!RopeMatch(cx, textstr, fm.pat, fm.patlen, &fm.match_))
+                return nullptr;
+        } else {
+            const jschar *text = textstr->asLinear().chars();
+            size_t textlen = textstr->length();
+            fm.match_ = StringMatch(text, textlen, fm.pat, fm.patlen);
+        }
+        return &fm;
+    }
+
+    /* If the pattern is not already a regular expression, make it so. */
+    bool normalizeRegExp(JSContext *cx, bool flat, unsigned optarg, CallArgs args)
+    {
+        if (re_.initialized())
+            return true;
+
+        /* Build RegExp from pattern string. */
+        RootedString opt(cx);
+        if (optarg < args.length()) {
+            opt = ToString<CanGC>(cx, args[optarg]);
+            if (!opt)
+                return false;
+        } else {
+            opt = nullptr;
+        }
+
+        Rooted<JSAtom *> patstr(cx);
+        if (flat) {
+            patstr = flattenPattern(cx, fm.patstr);
+            if (!patstr)
+                return false;
+        } else {
+            patstr = fm.patstr;
+        }
+        JS_ASSERT(patstr);
+
+        return cx->compartment()->regExps.get(cx, patstr, opt, &re_);
+    }
+
+    bool zeroLastIndex(JSContext *cx) {
+        if (!regExpIsObject())
+            return true;
+
+        // Use a fast path for same-global RegExp objects with writable
+        // lastIndex.
+        if (obj_->is<RegExpObject>() && obj_->nativeLookup(cx, cx->names().lastIndex)->writable()) {
+            obj_->as<RegExpObject>().zeroLastIndex();
+            return true;
+        }
+
+        // Handle everything else generically (including throwing if .lastIndex is non-writable).
+        RootedValue zero(cx, Int32Value(0));
+        return JSObject::setProperty(cx, obj_, obj_, cx->names().lastIndex, &zero, true);
+    }
+
+    RegExpShared &regExp() { return *re_; }
+
+    bool regExpIsObject() { return obj_ != nullptr; }
+    HandleObject regExpObject() {
+        JS_ASSERT(regExpIsObject());
+        return obj_;
+    }
+
+  private:
+    StringRegExpGuard(const StringRegExpGuard &) MOZ_DELETE;
+    void operator=(const StringRegExpGuard &) MOZ_DELETE;
+};
+
+} /* anonymous namespace */
+
+static bool
+DoMatchLocal(JSContext *cx, CallArgs args, RegExpStatics *res, Handle<JSLinearString*> input,
+             RegExpShared &re)
+{
+    size_t charsLen = input->length();
+    const jschar *chars = input->chars();
+
+    size_t i = 0;
+    ScopedMatchPairs matches(&cx->tempLifoAlloc());
+    RegExpRunStatus status = re.execute(cx, chars, charsLen, &i, matches);
+    if (status == RegExpRunStatus_Error)
+        return false;
+
+    if (status == RegExpRunStatus_Success_NotFound) {
+        args.rval().setNull();
+        return true;
+    }
+
+    if (!res->updateFromMatchPairs(cx, input, matches))
+        return false;
+
+    RootedValue rval(cx);
+    if (!CreateRegExpMatchResult(cx, input, matches, &rval))
+        return false;
+
+    args.rval().set(rval);
+    return true;
+}
+
+/* ES5 15.5.4.10 step 8. */
+static bool
+DoMatchGlobal(JSContext *cx, CallArgs args, RegExpStatics *res, Handle<JSLinearString*> input,
+              StringRegExpGuard &g)
+{
+    // Step 8a.
+    //
+    // This single zeroing of "lastIndex" covers all "lastIndex" changes in the
+    // rest of String.prototype.match, particularly in steps 8f(i) and
+    // 8f(iii)(2)(a).  Here's why.
+    //
+    // The inputs to the calls to RegExp.prototype.exec are a RegExp object
+    // whose .global is true and a string.  The only side effect of a call in
+    // these circumstances is that the RegExp's .lastIndex will be modified to
+    // the next starting index after the discovered match (or to 0 if there's
+    // no remaining match).  Because .lastIndex is a non-configurable data
+    // property and no script-controllable code executes after step 8a, passing
+    // step 8a implies *every* .lastIndex set succeeds.  String.prototype.match
+    // calls RegExp.prototype.exec repeatedly, and the last call doesn't match,
+    // so the final value of .lastIndex is 0: exactly the state after step 8a
+    // succeeds.  No spec step lets script observe intermediate .lastIndex
+    // values.
+    //
+    // The arrays returned by RegExp.prototype.exec always have a string at
+    // index 0, for which [[Get]]s have no side effects.
+    //
+    // Filling in a new array using [[DefineOwnProperty]] is unobservable.
+    //
+    // This is a tricky point, because after this set, our implementation *can*
+    // fail.  The key is that script can't distinguish these failure modes from
+    // one where, in spec terms, we fail immediately after step 8a.  That *in
+    // reality* we might have done extra matching work, or created a partial
+    // results array to return, or hit an interrupt, is irrelevant.  The
+    // script can't tell we did any of those things but didn't update
+    // .lastIndex.  Thus we can optimize steps 8b onward however we want,
+    // including eliminating intermediate .lastIndex sets, as long as we don't
+    // add ways for script to observe the intermediate states.
+    //
+    // In short: it's okay to cheat (by setting .lastIndex to 0, once) because
+    // we can't get caught.
+    if (!g.zeroLastIndex(cx))
+        return false;
+
+    // Step 8b.
+    AutoValueVector elements(cx);
+
+    size_t lastSuccessfulStart = 0;
+
+    // The loop variables from steps 8c-e aren't needed, as we use different
+    // techniques from the spec to implement step 8f's loop.
+
+    // Step 8f.
+    MatchPair match;
+    size_t charsLen = input->length();
+    const jschar *chars = input->chars();
+    RegExpShared &re = g.regExp();
+    for (size_t searchIndex = 0; searchIndex <= charsLen; ) {
+        if (!CheckForInterrupt(cx))
+            return false;
+
+        // Steps 8f(i-ii), minus "lastIndex" updates (see above).
+        size_t nextSearchIndex = searchIndex;
+        RegExpRunStatus status = re.executeMatchOnly(cx, chars, charsLen, &nextSearchIndex, match);
+        if (status == RegExpRunStatus_Error)
+            return false;
+
+        // Step 8f(ii).
+        if (status == RegExpRunStatus_Success_NotFound)
+            break;
+
+        lastSuccessfulStart = searchIndex;
+
+        // Steps 8f(iii)(1-3).
+        searchIndex = match.isEmpty() ? nextSearchIndex + 1 : nextSearchIndex;
+
+        // Step 8f(iii)(4-5).
+        JSLinearString *str = js_NewDependentString(cx, input, match.start, match.length());
+        if (!str)
+            return false;
+        if (!elements.append(StringValue(str)))
+            return false;
+    }
+
+    // Step 8g.
+    if (elements.empty()) {
+        args.rval().setNull();
+        return true;
+    }
+
+    // The last *successful* match updates the RegExpStatics. (Interestingly,
+    // this implies that String.prototype.match's semantics aren't those
+    // implied by the RegExp.prototype.exec calls in the ES5 algorithm.)
+    res->updateLazily(cx, input, &re, lastSuccessfulStart);
+
+    // Steps 8b, 8f(iii)(5-6), 8h.
+    JSObject *array = NewDenseCopiedArray(cx, elements.length(), elements.begin());
+    if (!array)
+        return false;
+
+    args.rval().setObject(*array);
+    return true;
+}
+
+static bool
+BuildFlatMatchArray(JSContext *cx, HandleString textstr, const FlatMatch &fm, CallArgs *args)
+{
+    if (fm.match() < 0) {
+        args->rval().setNull();
+        return true;
+    }
+
+    /* For this non-global match, produce a RegExp.exec-style array. */
+    RootedObject obj(cx, NewDenseEmptyArray(cx));
+    if (!obj)
+        return false;
+
+    RootedValue patternVal(cx, StringValue(fm.pattern()));
+    RootedValue matchVal(cx, Int32Value(fm.match()));
+    RootedValue textVal(cx, StringValue(textstr));
+
+    if (!JSObject::defineElement(cx, obj, 0, patternVal) ||
+        !JSObject::defineProperty(cx, obj, cx->names().index, matchVal) ||
+        !JSObject::defineProperty(cx, obj, cx->names().input, textVal))
+    {
+        return false;
+    }
+
+    args->rval().setObject(*obj);
+    return true;
+}
+
+/* ES5 15.5.4.10. */
+bool
+js::str_match(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /* Steps 1-2. */
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    /* Steps 3-4, plus the trailing-argument "flags" extension. */
+    StringRegExpGuard g(cx);
+    if (!g.init(cx, args, true))
+        return false;
+
+    /* Fast path when the search pattern can be searched for as a string. */
+    if (const FlatMatch *fm = g.tryFlatMatch(cx, str, 1, args.length()))
+        return BuildFlatMatchArray(cx, str, *fm, &args);
+
+    /* Return if there was an error in tryFlatMatch. */
+    if (cx->isExceptionPending())
+        return false;
+
+    /* Create regular-expression internals as needed to perform the match. */
+    if (!g.normalizeRegExp(cx, false, 1, args))
+        return false;
+
+    RegExpStatics *res = cx->global()->getRegExpStatics();
+    Rooted<JSLinearString*> linearStr(cx, str->ensureLinear(cx));
+    if (!linearStr)
+        return false;
+
+    /* Steps 5-6, 7. */
+    if (!g.regExp().global())
+        return DoMatchLocal(cx, args, res, linearStr, g.regExp());
+
+    /* Steps 6, 8. */
+    return DoMatchGlobal(cx, args, res, linearStr, g);
+}
+
+bool
+js::str_search(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    StringRegExpGuard g(cx);
+    if (!g.init(cx, args, true))
+        return false;
+    if (const FlatMatch *fm = g.tryFlatMatch(cx, str, 1, args.length())) {
+        args.rval().setInt32(fm->match());
+        return true;
+    }
+
+    if (cx->isExceptionPending())  /* from tryFlatMatch */
+        return false;
+
+    if (!g.normalizeRegExp(cx, false, 1, args))
+        return false;
+
+    Rooted<JSLinearString*> linearStr(cx, str->ensureLinear(cx));
+    if (!linearStr)
+        return false;
+
+    const jschar *chars = linearStr->chars();
+    size_t length = linearStr->length();
+    RegExpStatics *res = cx->global()->getRegExpStatics();
+
+    /* Per ECMAv5 15.5.4.12 (5) The last index property is ignored and left unchanged. */
+    size_t i = 0;
+    MatchPair match;
+
+    RegExpRunStatus status = g.regExp().executeMatchOnly(cx, chars, length, &i, match);
+    if (status == RegExpRunStatus_Error)
+        return false;
+
+    if (status == RegExpRunStatus_Success)
+        res->updateLazily(cx, linearStr, &g.regExp(), 0);
+
+    JS_ASSERT_IF(status == RegExpRunStatus_Success_NotFound, match.start == -1);
+    args.rval().setInt32(match.start);
+    return true;
+}
+
+// Utility for building a rope (lazy concatenation) of strings.
+class RopeBuilder {
+    JSContext *cx;
+    RootedString res;
+
+    RopeBuilder(const RopeBuilder &other) MOZ_DELETE;
+    void operator=(const RopeBuilder &other) MOZ_DELETE;
+
+  public:
+    RopeBuilder(JSContext *cx)
+      : cx(cx), res(cx, cx->runtime()->emptyString)
+    {}
+
+    inline bool append(HandleString str) {
+        res = ConcatStrings<CanGC>(cx, res, str);
+        return !!res;
+    }
+
+    inline JSString *result() {
+        return res;
+    }
+};
+
+namespace {
+
+struct ReplaceData
+{
+    ReplaceData(JSContext *cx)
+      : str(cx), g(cx), lambda(cx), elembase(cx), repstr(cx),
+        fig(cx, NullValue()), sb(cx)
+    {}
+
+    inline void setReplacementString(JSLinearString *string) {
+        JS_ASSERT(string);
+        lambda = nullptr;
+        elembase = nullptr;
+        repstr = string;
+
+        /* We're about to store pointers into the middle of our string. */
+        dollarEnd = repstr->chars() + repstr->length();
+        dollar = js_strchr_limit(repstr->chars(), '$', dollarEnd);
+    }
+
+    inline void setReplacementFunction(JSObject *func) {
+        JS_ASSERT(func);
+        lambda = func;
+        elembase = nullptr;
+        repstr = nullptr;
+        dollar = dollarEnd = nullptr;
+    }
+
+    RootedString       str;            /* 'this' parameter object as a string */
+    StringRegExpGuard  g;              /* regexp parameter object and private data */
+    RootedObject       lambda;         /* replacement function object or null */
+    RootedObject       elembase;       /* object for function(a){return b[a]} replace */
+    Rooted<JSLinearString*> repstr; /* replacement string */
+    const jschar       *dollar;        /* null or pointer to first $ in repstr */
+    const jschar       *dollarEnd;     /* limit pointer for js_strchr_limit */
+    int                leftIndex;      /* left context index in str->chars */
+    JSSubString        dollarStr;      /* for "$$" InterpretDollar result */
+    bool               calledBack;     /* record whether callback has been called */
+    FastInvokeGuard    fig;            /* used for lambda calls, also holds arguments */
+    StringBuffer       sb;             /* buffer built during DoMatch */
+};
+
+} /* anonymous namespace */
+
+static bool
+ReplaceRegExp(JSContext *cx, RegExpStatics *res, ReplaceData &rdata);
+
+static bool
+DoMatchForReplaceLocal(JSContext *cx, RegExpStatics *res, Handle<JSLinearString*> linearStr,
+                       RegExpShared &re, ReplaceData &rdata)
+{
+    size_t charsLen = linearStr->length();
+    size_t i = 0;
+    ScopedMatchPairs matches(&cx->tempLifoAlloc());
+    RegExpRunStatus status = re.execute(cx, linearStr->chars(), charsLen, &i, matches);
+    if (status == RegExpRunStatus_Error)
+        return false;
+
+    if (status == RegExpRunStatus_Success_NotFound)
+        return true;
+
+    if (!res->updateFromMatchPairs(cx, linearStr, matches))
+        return false;
+
+    return ReplaceRegExp(cx, res, rdata);
+}
+
+static bool
+DoMatchForReplaceGlobal(JSContext *cx, RegExpStatics *res, Handle<JSLinearString*> linearStr,
+                        RegExpShared &re, ReplaceData &rdata)
+{
+    size_t charsLen = linearStr->length();
+    ScopedMatchPairs matches(&cx->tempLifoAlloc());
+    for (size_t count = 0, i = 0; i <= charsLen; ++count) {
+        if (!CheckForInterrupt(cx))
+            return false;
+
+        RegExpRunStatus status = re.execute(cx, linearStr->chars(), charsLen, &i, matches);
+        if (status == RegExpRunStatus_Error)
+            return false;
+
+        if (status == RegExpRunStatus_Success_NotFound)
+            break;
+
+        if (!res->updateFromMatchPairs(cx, linearStr, matches))
+            return false;
+
+        if (!ReplaceRegExp(cx, res, rdata))
+            return false;
+        if (!res->matched())
+            ++i;
+    }
+
+    return true;
+}
+
+static bool
+InterpretDollar(RegExpStatics *res, const jschar *dp, const jschar *ep,
+                ReplaceData &rdata, JSSubString *out, size_t *skip)
+{
+    JS_ASSERT(*dp == '$');
+
+    /* If there is only a dollar, bail now */
+    if (dp + 1 >= ep)
+        return false;
+
+    /* Interpret all Perl match-induced dollar variables. */
+    jschar dc = dp[1];
+    if (JS7_ISDEC(dc)) {
+        /* ECMA-262 Edition 3: 1-9 or 01-99 */
+        unsigned num = JS7_UNDEC(dc);
+        if (num > res->getMatches().parenCount())
+            return false;
+
+        const jschar *cp = dp + 2;
+        if (cp < ep && (dc = *cp, JS7_ISDEC(dc))) {
+            unsigned tmp = 10 * num + JS7_UNDEC(dc);
+            if (tmp <= res->getMatches().parenCount()) {
+                cp++;
+                num = tmp;
+            }
+        }
+        if (num == 0)
+            return false;
+
+        *skip = cp - dp;
+
+        JS_ASSERT(num <= res->getMatches().parenCount());
+
+        /*
+         * Note: we index to get the paren with the (1-indexed) pair
+         * number, as opposed to a (0-indexed) paren number.
+         */
+        res->getParen(num, out);
+        return true;
+    }
+
+    *skip = 2;
+    switch (dc) {
+      case '$':
+        rdata.dollarStr.chars = dp;
+        rdata.dollarStr.length = 1;
+        *out = rdata.dollarStr;
+        return true;
+      case '&':
+        res->getLastMatch(out);
+        return true;
+      case '+':
+        res->getLastParen(out);
+        return true;
+      case '`':
+        res->getLeftContext(out);
+        return true;
+      case '\'':
+        res->getRightContext(out);
+        return true;
+    }
+    return false;
+}
+
+static bool
+FindReplaceLength(JSContext *cx, RegExpStatics *res, ReplaceData &rdata, size_t *sizep)
+{
+    if (rdata.elembase) {
+        /*
+         * The base object is used when replace was passed a lambda which looks like
+         * 'function(a) { return b[a]; }' for the base object b.  b will not change
+         * in the course of the replace unless we end up making a scripted call due
+         * to accessing a scripted getter or a value with a scripted toString.
+         */
+        JS_ASSERT(rdata.lambda);
+        JS_ASSERT(!rdata.elembase->getOps()->lookupProperty);
+        JS_ASSERT(!rdata.elembase->getOps()->getProperty);
+
+        RootedValue match(cx);
+        if (!res->createLastMatch(cx, &match))
+            return false;
+        JSAtom *atom = ToAtom<CanGC>(cx, match);
+        if (!atom)
+            return false;
+
+        RootedValue v(cx);
+        if (HasDataProperty(cx, rdata.elembase, AtomToId(atom), v.address()) && v.isString()) {
+            rdata.repstr = v.toString()->ensureLinear(cx);
+            if (!rdata.repstr)
+                return false;
+            *sizep = rdata.repstr->length();
+            return true;
+        }
+
+        /*
+         * Couldn't handle this property, fall through and despecialize to the
+         * general lambda case.
+         */
+        rdata.elembase = nullptr;
+    }
+
+    if (rdata.lambda) {
+        RootedObject lambda(cx, rdata.lambda);
+        PreserveRegExpStatics staticsGuard(cx, res);
+        if (!staticsGuard.init(cx))
+            return false;
+
+        /*
+         * In the lambda case, not only do we find the replacement string's
+         * length, we compute repstr and return it via rdata for use within
+         * DoReplace.  The lambda is called with arguments ($&, $1, $2, ...,
+         * index, input), i.e., all the properties of a regexp match array.
+         * For $&, etc., we must create string jsvals from cx->regExpStatics.
+         * We grab up stack space to keep the newborn strings GC-rooted.
+         */
+        unsigned p = res->getMatches().parenCount();
+        unsigned argc = 1 + p + 2;
+
+        InvokeArgs &args = rdata.fig.args();
+        if (!args.init(argc))
+            return false;
+
+        args.setCallee(ObjectValue(*lambda));
+        args.setThis(UndefinedValue());
+
+        /* Push $&, $1, $2, ... */
+        unsigned argi = 0;
+        if (!res->createLastMatch(cx, args[argi++]))
+            return false;
+
+        for (size_t i = 0; i < res->getMatches().parenCount(); ++i) {
+            if (!res->createParen(cx, i + 1, args[argi++]))
+                return false;
+        }
+
+        /* Push match index and input string. */
+        args[argi++].setInt32(res->getMatches()[0].start);
+        args[argi].setString(rdata.str);
+
+        if (!rdata.fig.invoke(cx))
+            return false;
+
+        /* root repstr: rdata is on the stack, so scanned by conservative gc. */
+        JSString *repstr = ToString<CanGC>(cx, args.rval());
+        if (!repstr)
+            return false;
+        rdata.repstr = repstr->ensureLinear(cx);
+        if (!rdata.repstr)
+            return false;
+        *sizep = rdata.repstr->length();
+        return true;
+    }
+
+    JSString *repstr = rdata.repstr;
+    CheckedInt<uint32_t> replen = repstr->length();
+    for (const jschar *dp = rdata.dollar, *ep = rdata.dollarEnd; dp;
+         dp = js_strchr_limit(dp, '$', ep)) {
+        JSSubString sub;
+        size_t skip;
+        if (InterpretDollar(res, dp, ep, rdata, &sub, &skip)) {
+            if (sub.length > skip)
+                replen += sub.length - skip;
+            else
+                replen -= skip - sub.length;
+            dp += skip;
+        } else {
+            dp++;
+        }
+    }
+
+    if (!replen.isValid()) {
+        js_ReportAllocationOverflow(cx);
+        return false;
+    }
+
+    *sizep = replen.value();
+    return true;
+}
+
+/*
+ * Precondition: |rdata.sb| already has necessary growth space reserved (as
+ * derived from FindReplaceLength).
+ */
+static void
+DoReplace(RegExpStatics *res, ReplaceData &rdata)
+{
+    JSLinearString *repstr = rdata.repstr;
+    const jschar *cp;
+    const jschar *bp = cp = repstr->chars();
+
+    const jschar *dp = rdata.dollar;
+    const jschar *ep = rdata.dollarEnd;
+    for (; dp; dp = js_strchr_limit(dp, '$', ep)) {
+        /* Move one of the constant portions of the replacement value. */
+        size_t len = dp - cp;
+        rdata.sb.infallibleAppend(cp, len);
+        cp = dp;
+
+        JSSubString sub;
+        size_t skip;
+        if (InterpretDollar(res, dp, ep, rdata, &sub, &skip)) {
+            len = sub.length;
+            rdata.sb.infallibleAppend(sub.chars, len);
+            cp += skip;
+            dp += skip;
+        } else {
+            dp++;
+        }
+    }
+    rdata.sb.infallibleAppend(cp, repstr->length() - (cp - bp));
+}
+
+static bool
+ReplaceRegExp(JSContext *cx, RegExpStatics *res, ReplaceData &rdata)
+{
+
+    const MatchPair &match = res->getMatches()[0];
+    JS_ASSERT(!match.isUndefined());
+    JS_ASSERT(match.limit >= match.start && match.limit >= 0);
+
+    rdata.calledBack = true;
+    size_t leftoff = rdata.leftIndex;
+    size_t leftlen = match.start - leftoff;
+    rdata.leftIndex = match.limit;
+
+    size_t replen = 0;  /* silence 'unused' warning */
+    if (!FindReplaceLength(cx, res, rdata, &replen))
+        return false;
+
+    CheckedInt<uint32_t> newlen(rdata.sb.length());
+    newlen += leftlen;
+    newlen += replen;
+    if (!newlen.isValid()) {
+        js_ReportAllocationOverflow(cx);
+        return false;
+    }
+    if (!rdata.sb.reserve(newlen.value()))
+        return false;
+
+    JSLinearString &str = rdata.str->asLinear();  /* flattened for regexp */
+    const jschar *left = str.chars() + leftoff;
+
+    rdata.sb.infallibleAppend(left, leftlen); /* skipped-over portion of the search value */
+    DoReplace(res, rdata);
+    return true;
+}
+
+static bool
+BuildFlatReplacement(JSContext *cx, HandleString textstr, HandleString repstr,
+                     const FlatMatch &fm, MutableHandleValue rval)
+{
+    RopeBuilder builder(cx);
+    size_t match = fm.match();
+    size_t matchEnd = match + fm.patternLength();
+
+    if (textstr->isRope()) {
+        /*
+         * If we are replacing over a rope, avoid flattening it by iterating
+         * through it, building a new rope.
+         */
+        StringSegmentRange r(cx);
+        if (!r.init(textstr))
+            return false;
+        size_t pos = 0;
+        while (!r.empty()) {
+            RootedString str(cx, r.front());
+            size_t len = str->length();
+            size_t strEnd = pos + len;
+            if (pos < matchEnd && strEnd > match) {
+                /*
+                 * We need to special-case any part of the rope that overlaps
+                 * with the replacement string.
+                 */
+                if (match >= pos) {
+                    /*
+                     * If this part of the rope overlaps with the left side of
+                     * the pattern, then it must be the only one to overlap with
+                     * the first character in the pattern, so we include the
+                     * replacement string here.
+                     */
+                    RootedString leftSide(cx, js_NewDependentString(cx, str, 0, match - pos));
+                    if (!leftSide ||
+                        !builder.append(leftSide) ||
+                        !builder.append(repstr)) {
+                        return false;
+                    }
+                }
+
+                /*
+                 * If str runs off the end of the matched string, append the
+                 * last part of str.
+                 */
+                if (strEnd > matchEnd) {
+                    RootedString rightSide(cx, js_NewDependentString(cx, str, matchEnd - pos,
+                                                                     strEnd - matchEnd));
+                    if (!rightSide || !builder.append(rightSide))
+                        return false;
+                }
+            } else {
+                if (!builder.append(str))
+                    return false;
+            }
+            pos += str->length();
+            if (!r.popFront())
+                return false;
+        }
+    } else {
+        RootedString leftSide(cx, js_NewDependentString(cx, textstr, 0, match));
+        if (!leftSide)
+            return false;
+        RootedString rightSide(cx);
+        rightSide = js_NewDependentString(cx, textstr, match + fm.patternLength(),
+                                          textstr->length() - match - fm.patternLength());
+        if (!rightSide ||
+            !builder.append(leftSide) ||
+            !builder.append(repstr) ||
+            !builder.append(rightSide)) {
+            return false;
+        }
+    }
+
+    rval.setString(builder.result());
+    return true;
+}
+
+/*
+ * Perform a linear-scan dollar substitution on the replacement text,
+ * constructing a result string that looks like:
+ *
+ *      newstring = string[:matchStart] + dollarSub(replaceValue) + string[matchLimit:]
+ */
+static inline bool
+BuildDollarReplacement(JSContext *cx, JSString *textstrArg, JSLinearString *repstr,
+                       const jschar *firstDollar, const FlatMatch &fm, MutableHandleValue rval)
+{
+    Rooted<JSLinearString*> textstr(cx, textstrArg->ensureLinear(cx));
+    if (!textstr)
+        return false;
+
+    JS_ASSERT(repstr->chars() <= firstDollar && firstDollar < repstr->chars() + repstr->length());
+    size_t matchStart = fm.match();
+    size_t matchLimit = matchStart + fm.patternLength();
+
+    /*
+     * Most probably:
+     *
+     *      len(newstr) >= len(orig) - len(match) + len(replacement)
+     *
+     * Note that dollar vars _could_ make the resulting text smaller than this.
+     */
+    StringBuffer newReplaceChars(cx);
+    if (!newReplaceChars.reserve(textstr->length() - fm.patternLength() + repstr->length()))
+        return false;
+
+    /* Move the pre-dollar chunk in bulk. */
+    newReplaceChars.infallibleAppend(repstr->chars(), firstDollar);
+
+    /* Move the rest char-by-char, interpreting dollars as we encounter them. */
+#define ENSURE(__cond) if (!(__cond)) return false;
+    const jschar *repstrLimit = repstr->chars() + repstr->length();
+    for (const jschar *it = firstDollar; it < repstrLimit; ++it) {
+        if (*it != '$' || it == repstrLimit - 1) {
+            ENSURE(newReplaceChars.append(*it));
+            continue;
+        }
+
+        switch (*(it + 1)) {
+          case '$': /* Eat one of the dollars. */
+            ENSURE(newReplaceChars.append(*it));
+            break;
+          case '&':
+            ENSURE(newReplaceChars.append(textstr->chars() + matchStart,
+                                          textstr->chars() + matchLimit));
+            break;
+          case '`':
+            ENSURE(newReplaceChars.append(textstr->chars(), textstr->chars() + matchStart));
+            break;
+          case '\'':
+            ENSURE(newReplaceChars.append(textstr->chars() + matchLimit,
+                                          textstr->chars() + textstr->length()));
+            break;
+          default: /* The dollar we saw was not special (no matter what its mother told it). */
+            ENSURE(newReplaceChars.append(*it));
+            continue;
+        }
+        ++it; /* We always eat an extra char in the above switch. */
+    }
+
+    RootedString leftSide(cx, js_NewDependentString(cx, textstr, 0, matchStart));
+    ENSURE(leftSide);
+
+    RootedString newReplace(cx, newReplaceChars.finishString());
+    ENSURE(newReplace);
+
+    JS_ASSERT(textstr->length() >= matchLimit);
+    RootedString rightSide(cx, js_NewDependentString(cx, textstr, matchLimit,
+                                                        textstr->length() - matchLimit));
+    ENSURE(rightSide);
+
+    RopeBuilder builder(cx);
+    ENSURE(builder.append(leftSide) &&
+           builder.append(newReplace) &&
+           builder.append(rightSide));
+#undef ENSURE
+
+    rval.setString(builder.result());
+    return true;
+}
+
+struct StringRange
+{
+    size_t start;
+    size_t length;
+
+    StringRange(size_t s, size_t l)
+      : start(s), length(l)
+    { }
+};
+
+static inline JSFatInlineString *
+FlattenSubstrings(JSContext *cx, const jschar *chars,
+                  const StringRange *ranges, size_t rangesLen, size_t outputLen)
+{
+    JS_ASSERT(JSFatInlineString::lengthFits(outputLen));
+
+    JSFatInlineString *str = js_NewGCFatInlineString<CanGC>(cx);
+    if (!str)
+        return nullptr;
+    jschar *buf = str->init(outputLen);
+
+    size_t pos = 0;
+    for (size_t i = 0; i < rangesLen; i++) {
+        PodCopy(buf + pos, chars + ranges[i].start, ranges[i].length);
+        pos += ranges[i].length;
+    }
+    JS_ASSERT(pos == outputLen);
+
+    buf[outputLen] = 0;
+    return str;
+}
+
+static JSString *
+AppendSubstrings(JSContext *cx, Handle<JSFlatString*> flatStr,
+                 const StringRange *ranges, size_t rangesLen)
+{
+    JS_ASSERT(rangesLen);
+
+    /* For single substrings, construct a dependent string. */
+    if (rangesLen == 1)
+        return js_NewDependentString(cx, flatStr, ranges[0].start, ranges[0].length);
+
+    const jschar *chars = flatStr->getChars(cx);
+    if (!chars)
+        return nullptr;
+
+    /* Collect substrings into a rope */
+    size_t i = 0;
+    RopeBuilder rope(cx);
+    RootedString part(cx, nullptr);
+    while (i < rangesLen) {
+
+        /* Find maximum range that fits in JSFatInlineString */
+        size_t substrLen = 0;
+        size_t end = i;
+        for (; end < rangesLen; end++) {
+            if (substrLen + ranges[end].length > JSFatInlineString::MAX_FAT_INLINE_LENGTH)
+                break;
+            substrLen += ranges[end].length;
+        }
+
+        if (i == end) {
+            /* Not even one range fits JSFatInlineString, use DependentString */
+            const StringRange &sr = ranges[i++];
+            part = js_NewDependentString(cx, flatStr, sr.start, sr.length);
+        } else {
+            /* Copy the ranges (linearly) into a JSFatInlineString */
+            part = FlattenSubstrings(cx, chars, ranges + i, end - i, substrLen);
+            i = end;
+        }
+
+        if (!part)
+            return nullptr;
+
+        /* Appending to the rope permanently roots the substring. */
+        if (!rope.append(part))
+            return nullptr;
+    }
+
+    return rope.result();
+}
+
+static bool
+StrReplaceRegexpRemove(JSContext *cx, HandleString str, RegExpShared &re, MutableHandleValue rval)
+{
+    Rooted<JSFlatString*> flatStr(cx, str->ensureFlat(cx));
+    if (!flatStr)
+        return false;
+
+    Vector<StringRange, 16, SystemAllocPolicy> ranges;
+
+    size_t charsLen = flatStr->length();
+
+    MatchPair match;
+    size_t startIndex = 0; /* Index used for iterating through the string. */
+    size_t lastIndex = 0;  /* Index after last successful match. */
+    size_t lazyIndex = 0;  /* Index before last successful match. */
+
+    /* Accumulate StringRanges for unmatched substrings. */
+    while (startIndex <= charsLen) {
+        if (!CheckForInterrupt(cx))
+            return false;
+
+        RegExpRunStatus status =
+            re.executeMatchOnly(cx, flatStr->chars(), charsLen, &startIndex, match);
+        if (status == RegExpRunStatus_Error)
+            return false;
+        if (status == RegExpRunStatus_Success_NotFound)
+            break;
+
+        /* Include the latest unmatched substring. */
+        if (size_t(match.start) > lastIndex) {
+            if (!ranges.append(StringRange(lastIndex, match.start - lastIndex)))
+                return false;
+        }
+
+        lazyIndex = lastIndex;
+        lastIndex = startIndex;
+
+        if (match.isEmpty())
+            startIndex++;
+
+        /* Non-global removal executes at most once. */
+        if (!re.global())
+            break;
+    }
+
+    /* If unmatched, return the input string. */
+    if (!lastIndex) {
+        if (startIndex > 0)
+            cx->global()->getRegExpStatics()->updateLazily(cx, flatStr, &re, lazyIndex);
+        rval.setString(str);
+        return true;
+    }
+
+    /* The last successful match updates the RegExpStatics. */
+    cx->global()->getRegExpStatics()->updateLazily(cx, flatStr, &re, lazyIndex);
+
+    /* Include any remaining part of the string. */
+    if (lastIndex < charsLen) {
+        if (!ranges.append(StringRange(lastIndex, charsLen - lastIndex)))
+            return false;
+    }
+
+    /* Handle the empty string before calling .begin(). */
+    if (ranges.empty()) {
+        rval.setString(cx->runtime()->emptyString);
+        return true;
+    }
+
+    JSString *result = AppendSubstrings(cx, flatStr, ranges.begin(), ranges.length());
+    if (!result)
+        return false;
+
+    rval.setString(result);
+    return true;
+}
+
+static inline bool
+StrReplaceRegExp(JSContext *cx, ReplaceData &rdata, MutableHandleValue rval)
+{
+    rdata.leftIndex = 0;
+    rdata.calledBack = false;
+
+    RegExpStatics *res = cx->global()->getRegExpStatics();
+    RegExpShared &re = rdata.g.regExp();
+
+    // The spec doesn't describe this function very clearly, so we go ahead and
+    // assume that when the input to String.prototype.replace is a global
+    // RegExp, calling the replacer function (assuming one was provided) takes
+    // place only after the matching is done. See the comment at the beginning
+    // of DoMatchGlobal explaining why we can zero the the RegExp object's
+    // lastIndex property here.
+    if (re.global() && !rdata.g.zeroLastIndex(cx))
+        return false;
+
+    /* Optimize removal. */
+    if (rdata.repstr && rdata.repstr->length() == 0) {
+        JS_ASSERT(!rdata.lambda && !rdata.elembase && !rdata.dollar);
+        return StrReplaceRegexpRemove(cx, rdata.str, re, rval);
+    }
+
+    Rooted<JSLinearString*> linearStr(cx, rdata.str->ensureLinear(cx));
+    if (!linearStr)
+        return false;
+
+    if (re.global()) {
+        if (!DoMatchForReplaceGlobal(cx, res, linearStr, re, rdata))
+            return false;
+    } else {
+        if (!DoMatchForReplaceLocal(cx, res, linearStr, re, rdata))
+            return false;
+    }
+
+    if (!rdata.calledBack) {
+        /* Didn't match, so the string is unmodified. */
+        rval.setString(rdata.str);
+        return true;
+    }
+
+    JSSubString sub;
+    res->getRightContext(&sub);
+    if (!rdata.sb.append(sub.chars, sub.length))
+        return false;
+
+    JSString *retstr = rdata.sb.finishString();
+    if (!retstr)
+        return false;
+
+    rval.setString(retstr);
+    return true;
+}
+
+static inline bool
+str_replace_regexp(JSContext *cx, CallArgs args, ReplaceData &rdata)
+{
+    if (!rdata.g.normalizeRegExp(cx, true, 2, args))
+        return false;
+
+    return StrReplaceRegExp(cx, rdata, args.rval());
+}
+
+bool
+js::str_replace_regexp_raw(JSContext *cx, HandleString string, HandleObject regexp,
+                       HandleString replacement, MutableHandleValue rval)
+{
+    /* Optimize removal, so we don't have to create ReplaceData */
+    if (replacement->length() == 0) {
+        StringRegExpGuard guard(cx);
+        if (!guard.init(cx, regexp))
+            return false;
+
+        RegExpShared &re = guard.regExp();
+        return StrReplaceRegexpRemove(cx, string, re, rval);
+    }
+
+    ReplaceData rdata(cx);
+    rdata.str = string;
+
+    JSLinearString *repl = replacement->ensureLinear(cx);
+    if (!repl)
+        return false;
+
+    rdata.setReplacementString(repl);
+
+    if (!rdata.g.init(cx, regexp))
+        return false;
+
+    return StrReplaceRegExp(cx, rdata, rval);
+}
+
+static inline bool
+StrReplaceString(JSContext *cx, ReplaceData &rdata, const FlatMatch &fm, MutableHandleValue rval)
+{
+    /*
+     * Note: we could optimize the text.length == pattern.length case if we wanted,
+     * even in the presence of dollar metachars.
+     */
+    if (rdata.dollar)
+        return BuildDollarReplacement(cx, rdata.str, rdata.repstr, rdata.dollar, fm, rval);
+    return BuildFlatReplacement(cx, rdata.str, rdata.repstr, fm, rval);
+}
+
+static const uint32_t ReplaceOptArg = 2;
+
+bool
+js::str_replace_string_raw(JSContext *cx, HandleString string, HandleString pattern,
+                          HandleString replacement, MutableHandleValue rval)
+{
+    ReplaceData rdata(cx);
+
+    rdata.str = string;
+    JSLinearString *repl = replacement->ensureLinear(cx);
+    if (!repl)
+        return false;
+    rdata.setReplacementString(repl);
+
+    if (!rdata.g.init(cx, pattern))
+        return false;
+    const FlatMatch *fm = rdata.g.tryFlatMatch(cx, rdata.str, ReplaceOptArg, ReplaceOptArg, false);
+
+    if (fm->match() < 0) {
+        rval.setString(string);
+        return true;
+    }
+
+    return StrReplaceString(cx, rdata, *fm, rval);
+}
+
+static inline bool
+str_replace_flat_lambda(JSContext *cx, CallArgs outerArgs, ReplaceData &rdata, const FlatMatch &fm)
+{
+    RootedString matchStr(cx, js_NewDependentString(cx, rdata.str, fm.match(), fm.patternLength()));
+    if (!matchStr)
+        return false;
+
+    /* lambda(matchStr, matchStart, textstr) */
+    static const uint32_t lambdaArgc = 3;
+    if (!rdata.fig.args().init(lambdaArgc))
+        return false;
+
+    CallArgs &args = rdata.fig.args();
+    args.setCallee(ObjectValue(*rdata.lambda));
+    args.setThis(UndefinedValue());
+
+    Value *sp = args.array();
+    sp[0].setString(matchStr);
+    sp[1].setInt32(fm.match());
+    sp[2].setString(rdata.str);
+
+    if (!rdata.fig.invoke(cx))
+        return false;
+
+    RootedString repstr(cx, ToString<CanGC>(cx, args.rval()));
+    if (!repstr)
+        return false;
+
+    RootedString leftSide(cx, js_NewDependentString(cx, rdata.str, 0, fm.match()));
+    if (!leftSide)
+        return false;
+
+    size_t matchLimit = fm.match() + fm.patternLength();
+    RootedString rightSide(cx, js_NewDependentString(cx, rdata.str, matchLimit,
+                                                        rdata.str->length() - matchLimit));
+    if (!rightSide)
+        return false;
+
+    RopeBuilder builder(cx);
+    if (!(builder.append(leftSide) &&
+          builder.append(repstr) &&
+          builder.append(rightSide))) {
+        return false;
+    }
+
+    outerArgs.rval().setString(builder.result());
+    return true;
+}
+
+/*
+ * Pattern match the script to check if it is is indexing into a particular
+ * object, e.g. 'function(a) { return b[a]; }'. Avoid calling the script in
+ * such cases, which are used by javascript packers (particularly the popular
+ * Dean Edwards packer) to efficiently encode large scripts. We only handle the
+ * code patterns generated by such packers here.
+ */
+static bool
+LambdaIsGetElem(JSContext *cx, JSObject &lambda, MutableHandleObject pobj)
+{
+    if (!lambda.is<JSFunction>())
+        return true;
+
+    RootedFunction fun(cx, &lambda.as<JSFunction>());
+    if (!fun->isInterpreted())
+        return true;
+
+    JSScript *script = fun->getOrCreateScript(cx);
+    if (!script)
+        return false;
+
+    jsbytecode *pc = script->code();
+
+    /*
+     * JSOP_GETALIASEDVAR tells us exactly where to find the base object 'b'.
+     * Rule out the (unlikely) possibility of a heavyweight function since it
+     * would make our scope walk off by 1.
+     */
+    if (JSOp(*pc) != JSOP_GETALIASEDVAR || fun->isHeavyweight())
+        return true;
+    ScopeCoordinate sc(pc);
+    ScopeObject *scope = &fun->environment()->as<ScopeObject>();
+    for (unsigned i = 0; i < sc.hops(); ++i)
+        scope = &scope->enclosingScope().as<ScopeObject>();
+    Value b = scope->aliasedVar(sc);
+    pc += JSOP_GETALIASEDVAR_LENGTH;
+
+    /* Look for 'a' to be the lambda's first argument. */
+    if (JSOp(*pc) != JSOP_GETARG || GET_ARGNO(pc) != 0)
+        return true;
+    pc += JSOP_GETARG_LENGTH;
+
+    /* 'b[a]' */
+    if (JSOp(*pc) != JSOP_GETELEM)
+        return true;
+    pc += JSOP_GETELEM_LENGTH;
+
+    /* 'return b[a]' */
+    if (JSOp(*pc) != JSOP_RETURN)
+        return true;
+
+    /* 'b' must behave like a normal object. */
+    if (!b.isObject())
+        return true;
+
+    JSObject &bobj = b.toObject();
+    const Class *clasp = bobj.getClass();
+    if (!clasp->isNative() || clasp->ops.lookupProperty || clasp->ops.getProperty)
+        return true;
+
+    pobj.set(&bobj);
+    return true;
+}
+
+bool
+js::str_replace(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    ReplaceData rdata(cx);
+    rdata.str = ThisToStringForStringProto(cx, args);
+    if (!rdata.str)
+        return false;
+
+    if (!rdata.g.init(cx, args))
+        return false;
+
+    /* Extract replacement string/function. */
+    if (args.length() >= ReplaceOptArg && js_IsCallable(args[1])) {
+        rdata.setReplacementFunction(&args[1].toObject());
+
+        if (!LambdaIsGetElem(cx, *rdata.lambda, &rdata.elembase))
+            return false;
+    } else {
+        JSLinearString *string = ArgToRootedString(cx, args, 1);
+        if (!string)
+            return false;
+
+        rdata.setReplacementString(string);
+    }
+
+    rdata.fig.initFunction(ObjectOrNullValue(rdata.lambda));
+
+    /*
+     * Unlike its |String.prototype| brethren, |replace| doesn't convert
+     * its input to a regular expression. (Even if it contains metachars.)
+     *
+     * However, if the user invokes our (non-standard) |flags| argument
+     * extension then we revert to creating a regular expression. Note that
+     * this is observable behavior through the side-effect mutation of the
+     * |RegExp| statics.
+     */
+
+    const FlatMatch *fm = rdata.g.tryFlatMatch(cx, rdata.str, ReplaceOptArg, args.length(), false);
+
+    if (!fm) {
+        if (cx->isExceptionPending())  /* oom in RopeMatch in tryFlatMatch */
+            return false;
+        return str_replace_regexp(cx, args, rdata);
+    }
+
+    if (fm->match() < 0) {
+        args.rval().setString(rdata.str);
+        return true;
+    }
+
+    if (rdata.lambda)
+        return str_replace_flat_lambda(cx, args, rdata, *fm);
+    return StrReplaceString(cx, rdata, *fm, args.rval());
+}
+
+namespace {
+
+class SplitMatchResult {
+    size_t endIndex_;
+    size_t length_;
+
+  public:
+    void setFailure() {
+        JS_STATIC_ASSERT(SIZE_MAX > JSString::MAX_LENGTH);
+        endIndex_ = SIZE_MAX;
+    }
+    bool isFailure() const {
+        return endIndex_ == SIZE_MAX;
+    }
+    size_t endIndex() const {
+        JS_ASSERT(!isFailure());
+        return endIndex_;
+    }
+    size_t length() const {
+        JS_ASSERT(!isFailure());
+        return length_;
+    }
+    void setResult(size_t length, size_t endIndex) {
+        length_ = length;
+        endIndex_ = endIndex;
+    }
+};
+
+} /* anonymous namespace */
+
+template<class Matcher>
+static ArrayObject *
+SplitHelper(JSContext *cx, Handle<JSLinearString*> str, uint32_t limit, const Matcher &splitMatch,
+            Handle<TypeObject*> type)
+{
+    size_t strLength = str->length();
+    SplitMatchResult result;
+
+    /* Step 11. */
+    if (strLength == 0) {
+        if (!splitMatch(cx, str, 0, &result))
+            return nullptr;
+
+        /*
+         * NB: Unlike in the non-empty string case, it's perfectly fine
+         *     (indeed the spec requires it) if we match at the end of the
+         *     string.  Thus these cases should hold:
+         *
+         *   var a = "".split("");
+         *   assertEq(a.length, 0);
+         *   var b = "".split(/.?/);
+         *   assertEq(b.length, 0);
+         */
+        if (!result.isFailure())
+            return NewDenseEmptyArray(cx);
+
+        RootedValue v(cx, StringValue(str));
+        return NewDenseCopiedArray(cx, 1, v.address());
+    }
+
+    /* Step 12. */
+    size_t lastEndIndex = 0;
+    size_t index = 0;
+
+    /* Step 13. */
+    AutoValueVector splits(cx);
+
+    while (index < strLength) {
+        /* Step 13(a). */
+        if (!splitMatch(cx, str, index, &result))
+            return nullptr;
+
+        /*
+         * Step 13(b).
+         *
+         * Our match algorithm differs from the spec in that it returns the
+         * next index at which a match happens.  If no match happens we're
+         * done.
+         *
+         * But what if the match is at the end of the string (and the string is
+         * not empty)?  Per 13(c)(ii) this shouldn't be a match, so we have to
+         * specially exclude it.  Thus this case should hold:
+         *
+         *   var a = "abc".split(/\b/);
+         *   assertEq(a.length, 1);
+         *   assertEq(a[0], "abc");
+         */
+        if (result.isFailure())
+            break;
+
+        /* Step 13(c)(i). */
+        size_t sepLength = result.length();
+        size_t endIndex = result.endIndex();
+        if (sepLength == 0 && endIndex == strLength)
+            break;
+
+        /* Step 13(c)(ii). */
+        if (endIndex == lastEndIndex) {
+            index++;
+            continue;
+        }
+
+        /* Step 13(c)(iii). */
+        JS_ASSERT(lastEndIndex < endIndex);
+        JS_ASSERT(sepLength <= strLength);
+        JS_ASSERT(lastEndIndex + sepLength <= endIndex);
+
+        /* Steps 13(c)(iii)(1-3). */
+        size_t subLength = size_t(endIndex - sepLength - lastEndIndex);
+        JSString *sub = js_NewDependentString(cx, str, lastEndIndex, subLength);
+        if (!sub || !splits.append(StringValue(sub)))
+            return nullptr;
+
+        /* Step 13(c)(iii)(4). */
+        if (splits.length() == limit)
+            return NewDenseCopiedArray(cx, splits.length(), splits.begin());
+
+        /* Step 13(c)(iii)(5). */
+        lastEndIndex = endIndex;
+
+        /* Step 13(c)(iii)(6-7). */
+        if (Matcher::returnsCaptures) {
+            RegExpStatics *res = cx->global()->getRegExpStatics();
+            const MatchPairs &matches = res->getMatches();
+            for (size_t i = 0; i < matches.parenCount(); i++) {
+                /* Steps 13(c)(iii)(7)(a-c). */
+                if (!matches[i + 1].isUndefined()) {
+                    JSSubString parsub;
+                    res->getParen(i + 1, &parsub);
+                    sub = js_NewStringCopyN<CanGC>(cx, parsub.chars, parsub.length);
+                    if (!sub || !splits.append(StringValue(sub)))
+                        return nullptr;
+                } else {
+                    /* Only string entries have been accounted for so far. */
+                    AddTypePropertyId(cx, type, JSID_VOID, UndefinedValue());
+                    if (!splits.append(UndefinedValue()))
+                        return nullptr;
+                }
+
+                /* Step 13(c)(iii)(7)(d). */
+                if (splits.length() == limit)
+                    return NewDenseCopiedArray(cx, splits.length(), splits.begin());
+            }
+        }
+
+        /* Step 13(c)(iii)(8). */
+        index = lastEndIndex;
+    }
+
+    /* Steps 14-15. */
+    JSString *sub = js_NewDependentString(cx, str, lastEndIndex, strLength - lastEndIndex);
+    if (!sub || !splits.append(StringValue(sub)))
+        return nullptr;
+
+    /* Step 16. */
+    return NewDenseCopiedArray(cx, splits.length(), splits.begin());
+}
+
+// Fast-path for splitting a string into a character array via split("").
+static ArrayObject *
+CharSplitHelper(JSContext *cx, Handle<JSLinearString*> str, uint32_t limit)
+{
+    size_t strLength = str->length();
+    if (strLength == 0)
+        return NewDenseEmptyArray(cx);
+
+    js::StaticStrings &staticStrings = cx->staticStrings();
+    uint32_t resultlen = (limit < strLength ? limit : strLength);
+
+    AutoValueVector splits(cx);
+    if (!splits.reserve(resultlen))
+        return nullptr;
+
+    for (size_t i = 0; i < resultlen; ++i) {
+        JSString *sub = staticStrings.getUnitStringForElement(cx, str, i);
+        if (!sub)
+            return nullptr;
+        splits.infallibleAppend(StringValue(sub));
+    }
+
+    return NewDenseCopiedArray(cx, splits.length(), splits.begin());
+}
+
+namespace {
+
+/*
+ * The SplitMatch operation from ES5 15.5.4.14 is implemented using different
+ * paths for regular expression and string separators.
+ *
+ * The algorithm differs from the spec in that the we return the next index at
+ * which a match happens.
+ */
+class SplitRegExpMatcher
+{
+    RegExpShared &re;
+    RegExpStatics *res;
+
+  public:
+    SplitRegExpMatcher(RegExpShared &re, RegExpStatics *res) : re(re), res(res) {}
+
+    static const bool returnsCaptures = true;
+
+    bool operator()(JSContext *cx, Handle<JSLinearString*> str, size_t index,
+                    SplitMatchResult *result) const
+    {
+        const jschar *chars = str->chars();
+        size_t length = str->length();
+
+        ScopedMatchPairs matches(&cx->tempLifoAlloc());
+        RegExpRunStatus status = re.execute(cx, chars, length, &index, matches);
+        if (status == RegExpRunStatus_Error)
+            return false;
+
+        if (status == RegExpRunStatus_Success_NotFound) {
+            result->setFailure();
+            return true;
+        }
+
+        if (!res->updateFromMatchPairs(cx, str, matches))
+            return false;
+
+        JSSubString sep;
+        res->getLastMatch(&sep);
+
+        result->setResult(sep.length, index);
+        return true;
+    }
+};
+
+class SplitStringMatcher
+{
+    Rooted<JSLinearString*> sep;
+
+  public:
+    SplitStringMatcher(JSContext *cx, HandleLinearString sep)
+      : sep(cx, sep)
+    {}
+
+    static const bool returnsCaptures = false;
+
+    bool operator()(JSContext *cx, JSLinearString *str, size_t index, SplitMatchResult *res) const
+    {
+        JS_ASSERT(index == 0 || index < str->length());
+        const jschar *chars = str->chars();
+        int match = StringMatch(chars + index, str->length() - index,
+                                sep->chars(), sep->length());
+        if (match == -1)
+            res->setFailure();
+        else
+            res->setResult(sep->length(), index + match + sep->length());
+        return true;
+    }
+};
+
+} /* anonymous namespace */
+
+/* ES5 15.5.4.14 */
+bool
+js::str_split(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    /* Steps 1-2. */
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    RootedTypeObject type(cx, GetTypeCallerInitObject(cx, JSProto_Array));
+    if (!type)
+        return false;
+    AddTypePropertyId(cx, type, JSID_VOID, Type::StringType());
+
+    /* Step 5: Use the second argument as the split limit, if given. */
+    uint32_t limit;
+    if (args.hasDefined(1)) {
+        double d;
+        if (!ToNumber(cx, args[1], &d))
+            return false;
+        limit = ToUint32(d);
+    } else {
+        limit = UINT32_MAX;
+    }
+
+    /* Step 8. */
+    RegExpGuard re(cx);
+    RootedLinearString sepstr(cx);
+    bool sepDefined = args.hasDefined(0);
+    if (sepDefined) {
+        if (IsObjectWithClass(args[0], ESClass_RegExp, cx)) {
+            RootedObject obj(cx, &args[0].toObject());
+            if (!RegExpToShared(cx, obj, &re))
+                return false;
+        } else {
+            sepstr = ArgToRootedString(cx, args, 0);
+            if (!sepstr)
+                return false;
+        }
+    }
+
+    /* Step 9. */
+    if (limit == 0) {
+        JSObject *aobj = NewDenseEmptyArray(cx);
+        if (!aobj)
+            return false;
+        aobj->setType(type);
+        args.rval().setObject(*aobj);
+        return true;
+    }
+
+    /* Step 10. */
+    if (!sepDefined) {
+        RootedValue v(cx, StringValue(str));
+        JSObject *aobj = NewDenseCopiedArray(cx, 1, v.address());
+        if (!aobj)
+            return false;
+        aobj->setType(type);
+        args.rval().setObject(*aobj);
+        return true;
+    }
+    Rooted<JSLinearString*> linearStr(cx, str->ensureLinear(cx));
+    if (!linearStr)
+        return false;
+
+    /* Steps 11-15. */
+    RootedObject aobj(cx);
+    if (!re.initialized()) {
+        if (sepstr->length() == 0) {
+            aobj = CharSplitHelper(cx, linearStr, limit);
+        } else {
+            SplitStringMatcher matcher(cx, sepstr);
+            aobj = SplitHelper(cx, linearStr, limit, matcher, type);
+        }
+    } else {
+        SplitRegExpMatcher matcher(*re, cx->global()->getRegExpStatics());
+        aobj = SplitHelper(cx, linearStr, limit, matcher, type);
+    }
+    if (!aobj)
+        return false;
+
+    /* Step 16. */
+    aobj->setType(type);
+    args.rval().setObject(*aobj);
+    return true;
+}
+
+JSObject *
+js::str_split_string(JSContext *cx, HandleTypeObject type, HandleString str, HandleString sep)
+{
+    Rooted<JSLinearString*> linearStr(cx, str->ensureLinear(cx));
+    if (!linearStr)
+        return nullptr;
+
+    Rooted<JSLinearString*> linearSep(cx, sep->ensureLinear(cx));
+    if (!linearSep)
+        return nullptr;
+
+    uint32_t limit = UINT32_MAX;
+
+    RootedObject aobj(cx);
+    if (linearSep->length() == 0) {
+        aobj = CharSplitHelper(cx, linearStr, limit);
+    } else {
+        SplitStringMatcher matcher(cx, linearSep);
+        aobj = SplitHelper(cx, linearStr, limit, matcher, type);
+    }
+
+    if (!aobj)
+        return nullptr;
+
+    aobj->setType(type);
+    return aobj;
+}
+
+static bool
+str_substr(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    int32_t length, len, begin;
+    if (args.length() > 0) {
+        length = int32_t(str->length());
+        if (!ValueToIntegerRange(cx, args[0], &begin))
+            return false;
+
+        if (begin >= length) {
+            args.rval().setString(cx->runtime()->emptyString);
+            return true;
+        }
+        if (begin < 0) {
+            begin += length; /* length + INT_MIN will always be less than 0 */
+            if (begin < 0)
+                begin = 0;
+        }
+
+        if (args.hasDefined(1)) {
+            if (!ValueToIntegerRange(cx, args[1], &len))
+                return false;
+
+            if (len <= 0) {
+                args.rval().setString(cx->runtime()->emptyString);
+                return true;
+            }
+
+            if (uint32_t(length) < uint32_t(begin + len))
+                len = length - begin;
+        } else {
+            len = length - begin;
+        }
+
+        str = DoSubstr(cx, str, size_t(begin), size_t(len));
+        if (!str)
+            return false;
+    }
+
+    args.rval().setString(str);
+    return true;
+}
+
+/*
+ * Python-esque sequence operations.
+ */
+static bool
+str_concat(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    JSString *str = ThisToStringForStringProto(cx, args);
+    if (!str)
+        return false;
+
+    for (unsigned i = 0; i < args.length(); i++) {
+        JSString *argStr = ToString<NoGC>(cx, args[i]);
+        if (!argStr) {
+            RootedString strRoot(cx, str);
+            argStr = ToString<CanGC>(cx, args[i]);
+            if (!argStr)
+                return false;
+            str = strRoot;
+        }
+
+        JSString *next = ConcatStrings<NoGC>(cx, str, argStr);
+        if (next) {
+            str = next;
+        } else {
+            RootedString strRoot(cx, str), argStrRoot(cx, argStr);
+            str = ConcatStrings<CanGC>(cx, strRoot, argStrRoot);
+            if (!str)
+                return false;
+        }
+    }
+
+    args.rval().setString(str);
+    return true;
+}
+
+static bool
+str_slice(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    if (args.length() == 1 && args.thisv().isString() && args[0].isInt32()) {
+        JSString *str = args.thisv().toString();
+        size_t begin = args[0].toInt32();
+        size_t end = str->length();
+        if (begin <= end) {
+            size_t length = end - begin;
+            if (length == 0) {
+                str = cx->runtime()->emptyString;
+            } else {
+                str = (length == 1)
+                      ? cx->staticStrings().getUnitStringForElement(cx, str, begin)
+                      : js_NewDependentString(cx, str, begin, length);
+                if (!str)
+                    return false;
+            }
+            args.rval().setString(str);
+            return true;
+        }
+    }
+
+    RootedString str(cx, ThisToStringForStringProto(cx, args));
+    if (!str)
+        return false;
+
+    if (args.length() != 0) {
+        double begin, end, length;
+
+        if (!ToInteger(cx, args[0], &begin))
+            return false;
+        length = str->length();
+        if (begin < 0) {
+            begin += length;
+            if (begin < 0)
+                begin = 0;
+        } else if (begin > length) {
+            begin = length;
+        }
+
+        if (args.hasDefined(1)) {
+            if (!ToInteger(cx, args[1], &end))
+                return false;
+            if (end < 0) {
+                end += length;
+                if (end < 0)
+                    end = 0;
+            } else if (end > length) {
+                end = length;
+            }
+            if (end < begin)
+                end = begin;
+        } else {
+            end = length;
+        }
+
+        str = js_NewDependentString(cx, str,
+                                    (size_t)begin,
+                                    (size_t)(end - begin));
+        if (!str)
+            return false;
+    }
+    args.rval().setString(str);
+    return true;
+}
+
+#if JS_HAS_STR_HTML_HELPERS
+/*
+ * HTML composition aids.
+ */
+static bool
+tagify(JSContext *cx, const char *begin, HandleLinearString param, const char *end,
+       CallReceiver call)
+{
+    JSString *thisstr = ThisToStringForStringProto(cx, call);
+    if (!thisstr)
+        return false;
+
+    JSLinearString *str = thisstr->ensureLinear(cx);
+    if (!str)
+        return false;
+
+    if (!end)
+        end = begin;
+
+    size_t beglen = strlen(begin);
+    size_t taglen = 1 + beglen + 1;                     /* '<begin' + '>' */
+    if (param) {
+        size_t numChars = param->length();
+        const jschar *parchars = param->chars();
+        for (size_t i = 0, parlen = numChars; i < parlen; ++i) {
+            if (parchars[i] == '"')
+                numChars += 5;                          /* len(&quot;) - len(") */
+        }
+        taglen += 2 + numChars + 1;                     /* '="param"' */
+    }
+    size_t endlen = strlen(end);
+    taglen += str->length() + 2 + endlen + 1;           /* 'str</end>' */
+
+
+    StringBuffer sb(cx);
+    if (!sb.reserve(taglen))
+        return false;
+
+    sb.infallibleAppend('<');
+
+    MOZ_ALWAYS_TRUE(sb.appendInflated(begin, beglen));
+
+    if (param) {
+        sb.infallibleAppend('=');
+        sb.infallibleAppend('"');
+        const jschar *parchars = param->chars();
+        for (size_t i = 0, parlen = param->length(); i < parlen; ++i) {
+            if (parchars[i] != '"') {
+                sb.infallibleAppend(parchars[i]);
+            } else {
+                MOZ_ALWAYS_TRUE(sb.append("&quot;"));
+            }
+        }
+        sb.infallibleAppend('"');
+    }
+
+    sb.infallibleAppend('>');
+
+    MOZ_ALWAYS_TRUE(sb.append(str));
+
+    sb.infallibleAppend('<');
+    sb.infallibleAppend('/');
+
+    MOZ_ALWAYS_TRUE(sb.appendInflated(end, endlen));
+
+    sb.infallibleAppend('>');
+
+    JSFlatString *retstr = sb.finishString();
+    if (!retstr)
+        return false;
+
+    call.rval().setString(retstr);
+    return true;
+}
+
+static bool
+tagify_value(JSContext *cx, CallArgs args, const char *begin, const char *end)
+{
+    RootedLinearString param(cx, ArgToRootedString(cx, args, 0));
+    if (!param)
+        return false;
+
+    return tagify(cx, begin, param, end, args);
+}
+
+static bool
+str_bold(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "b", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_italics(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "i", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_fixed(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "tt", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_fontsize(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify_value(cx, CallArgsFromVp(argc, vp), "font size", "font");
+}
+
+static bool
+str_fontcolor(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify_value(cx, CallArgsFromVp(argc, vp), "font color", "font");
+}
+
+static bool
+str_link(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify_value(cx, CallArgsFromVp(argc, vp), "a href", "a");
+}
+
+static bool
+str_anchor(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify_value(cx, CallArgsFromVp(argc, vp), "a name", "a");
+}
+
+static bool
+str_strike(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "strike", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_small(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "small", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_big(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "big", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_blink(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "blink", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_sup(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "sup", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+
+static bool
+str_sub(JSContext *cx, unsigned argc, Value *vp)
+{
+    return tagify(cx, "sub", NullPtr(), nullptr, CallReceiverFromVp(vp));
+}
+#endif /* JS_HAS_STR_HTML_HELPERS */
+
+static const JSFunctionSpec string_methods[] = {
+#if JS_HAS_TOSOURCE
+    JS_FN("quote",             str_quote,             0,JSFUN_GENERIC_NATIVE),
+    JS_FN(js_toSource_str,     str_toSource,          0,0),
+#endif
+
+    /* Java-like methods. */
+    JS_FN(js_toString_str,     js_str_toString,       0,0),
+    JS_FN(js_valueOf_str,      js_str_toString,       0,0),
+    JS_FN("substring",         str_substring,         2,JSFUN_GENERIC_NATIVE),
+    JS_FN("toLowerCase",       str_toLowerCase,       0,JSFUN_GENERIC_NATIVE),
+    JS_FN("toUpperCase",       str_toUpperCase,       0,JSFUN_GENERIC_NATIVE),
+    JS_FN("charAt",            js_str_charAt,         1,JSFUN_GENERIC_NATIVE),
+    JS_FN("charCodeAt",        js_str_charCodeAt,     1,JSFUN_GENERIC_NATIVE),
+    JS_SELF_HOSTED_FN("codePointAt", "String_codePointAt", 1,0),
+    JS_FN("contains",          str_contains,          1,JSFUN_GENERIC_NATIVE),
+    JS_FN("indexOf",           str_indexOf,           1,JSFUN_GENERIC_NATIVE),
+    JS_FN("lastIndexOf",       str_lastIndexOf,       1,JSFUN_GENERIC_NATIVE),
+    JS_FN("startsWith",        str_startsWith,        1,JSFUN_GENERIC_NATIVE),
+    JS_FN("endsWith",          str_endsWith,          1,JSFUN_GENERIC_NATIVE),
+    JS_FN("trim",              str_trim,              0,JSFUN_GENERIC_NATIVE),
+    JS_FN("trimLeft",          str_trimLeft,          0,JSFUN_GENERIC_NATIVE),
+    JS_FN("trimRight",         str_trimRight,         0,JSFUN_GENERIC_NATIVE),
+    JS_FN("toLocaleLowerCase", str_toLocaleLowerCase, 0,JSFUN_GENERIC_NATIVE),
+    JS_FN("toLocaleUpperCase", str_toLocaleUpperCase, 0,JSFUN_GENERIC_NATIVE),
+#if EXPOSE_INTL_API
+    JS_SELF_HOSTED_FN("localeCompare", "String_localeCompare", 1,0),
+#else
+    JS_FN("localeCompare",     str_localeCompare,     1,JSFUN_GENERIC_NATIVE),
+#endif
+    JS_SELF_HOSTED_FN("repeat", "String_repeat",      1,0),
+#if EXPOSE_INTL_API
+    JS_FN("normalize",         str_normalize,         0,JSFUN_GENERIC_NATIVE),
+#endif
+
+    /* Perl-ish methods (search is actually Python-esque). */
+    JS_FN("match",             str_match,             1,JSFUN_GENERIC_NATIVE),
+    JS_FN("search",            str_search,            1,JSFUN_GENERIC_NATIVE),
+    JS_FN("replace",           str_replace,           2,JSFUN_GENERIC_NATIVE),
+    JS_FN("split",             str_split,             2,JSFUN_GENERIC_NATIVE),
+    JS_FN("substr",            str_substr,            2,JSFUN_GENERIC_NATIVE),
+
+    /* Python-esque sequence methods. */
+    JS_FN("concat",            str_concat,            1,JSFUN_GENERIC_NATIVE),
+    JS_FN("slice",             str_slice,             2,JSFUN_GENERIC_NATIVE),
+
+    /* HTML string methods. */
+#if JS_HAS_STR_HTML_HELPERS
+    JS_FN("bold",              str_bold,              0,0),
+    JS_FN("italics",           str_italics,           0,0),
+    JS_FN("fixed",             str_fixed,             0,0),
+    JS_FN("fontsize",          str_fontsize,          1,0),
+    JS_FN("fontcolor",         str_fontcolor,         1,0),
+    JS_FN("link",              str_link,              1,0),
+    JS_FN("anchor",            str_anchor,            1,0),
+    JS_FN("strike",            str_strike,            0,0),
+    JS_FN("small",             str_small,             0,0),
+    JS_FN("big",               str_big,               0,0),
+    JS_FN("blink",             str_blink,             0,0),
+    JS_FN("sup",               str_sup,               0,0),
+    JS_FN("sub",               str_sub,               0,0),
+#endif
+    JS_SELF_HOSTED_FN("@@iterator", "String_iterator", 0,0),
+    JS_FS_END
+};
+
+bool
+js_String(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    RootedString str(cx);
+    if (args.length() > 0) {
+        str = ToString<CanGC>(cx, args[0]);
+        if (!str)
+            return false;
+    } else {
+        str = cx->runtime()->emptyString;
+    }
+
+    if (args.isConstructing()) {
+        StringObject *strobj = StringObject::create(cx, str);
+        if (!strobj)
+            return false;
+        args.rval().setObject(*strobj);
+        return true;
+    }
+
+    args.rval().setString(str);
+    return true;
+}
+
+bool
+js::str_fromCharCode(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    JS_ASSERT(args.length() <= ARGS_LENGTH_MAX);
+    if (args.length() == 1) {
+        uint16_t code;
+        if (!ToUint16(cx, args[0], &code))
+            return false;
+        if (StaticStrings::hasUnit(code)) {
+            args.rval().setString(cx->staticStrings().getUnit(code));
+            return true;
+        }
+        args[0].setInt32(code);
+    }
+    jschar *chars = cx->pod_malloc<jschar>(args.length() + 1);
+    if (!chars)
+        return false;
+    for (unsigned i = 0; i < args.length(); i++) {
+        uint16_t code;
+        if (!ToUint16(cx, args[i], &code)) {
+            js_free(chars);
+            return false;
+        }
+        chars[i] = (jschar)code;
+    }
+    chars[args.length()] = 0;
+    JSString *str = js_NewString<CanGC>(cx, chars, args.length());
+    if (!str) {
+        js_free(chars);
+        return false;
+    }
+
+    args.rval().setString(str);
+    return true;
+}
+
+static const JSFunctionSpec string_static_methods[] = {
+    JS_FN("fromCharCode", js::str_fromCharCode, 1, 0),
+    JS_SELF_HOSTED_FN("fromCodePoint", "String_static_fromCodePoint", 0,0),
+
+    // This must be at the end because of bug 853075: functions listed after
+    // self-hosted methods aren't available in self-hosted code.
+#if EXPOSE_INTL_API
+    JS_SELF_HOSTED_FN("localeCompare", "String_static_localeCompare", 2,0),
+#endif
+    JS_FS_END
+};
+
+/* static */ Shape *
+StringObject::assignInitialShape(ExclusiveContext *cx, Handle<StringObject*> obj)
+{
+    JS_ASSERT(obj->nativeEmpty());
+
+    return obj->addDataProperty(cx, cx->names().length, LENGTH_SLOT,
+                                JSPROP_PERMANENT | JSPROP_READONLY);
+}
+
+JSObject *
+js_InitStringClass(JSContext *cx, HandleObject obj)
+{
+    JS_ASSERT(obj->isNative());
+
+    Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
+
+    Rooted<JSString*> empty(cx, cx->runtime()->emptyString);
+    RootedObject proto(cx, global->createBlankPrototype(cx, &StringObject::class_));
+    if (!proto || !proto->as<StringObject>().init(cx, empty))
+        return nullptr;
+
+    /* Now create the String function. */
+    RootedFunction ctor(cx);
+    ctor = global->createConstructor(cx, js_String, cx->names().String, 1);
+    if (!ctor)
+        return nullptr;
+
+    if (!LinkConstructorAndPrototype(cx, ctor, proto))
+        return nullptr;
+
+    if (!DefinePropertiesAndBrand(cx, proto, nullptr, string_methods) ||
+        !DefinePropertiesAndBrand(cx, ctor, nullptr, string_static_methods))
+    {
+        return nullptr;
+    }
+
+    if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_String, ctor, proto))
+        return nullptr;
+
+    /*
+     * Define escape/unescape, the URI encode/decode functions, and maybe
+     * uneval on the global object.
+     */
+    if (!JS_DefineFunctions(cx, global, string_functions))
+        return nullptr;
+
+    return proto;
+}
+
+template <AllowGC allowGC>
+JSFlatString *
+js_NewString(ThreadSafeContext *cx, jschar *chars, size_t length)
+{
+    if (length == 1) {
+        jschar c = chars[0];
+        if (StaticStrings::hasUnit(c)) {
+            // Free |chars| because we're taking possession of it, but it's no
+            // longer needed because we use the static string instead.
+            js_free(chars);
+            return cx->staticStrings().getUnit(c);
+        }
+    }
+
+    return JSFlatString::new_<allowGC>(cx, chars, length);
+}
+
+template JSFlatString *
+js_NewString<CanGC>(ThreadSafeContext *cx, jschar *chars, size_t length);
+
+template JSFlatString *
+js_NewString<NoGC>(ThreadSafeContext *cx, jschar *chars, size_t length);
+
+JSLinearString *
+js_NewDependentString(JSContext *cx, JSString *baseArg, size_t start, size_t length)
+{
+    if (length == 0)
+        return cx->emptyString();
+
+    JSLinearString *base = baseArg->ensureLinear(cx);
+    if (!base)
+        return nullptr;
+
+    if (start == 0 && length == base->length())
+        return base;
+
+    const jschar *chars = base->chars() + start;
+
+    if (JSLinearString *staticStr = cx->staticStrings().lookup(chars, length))
+        return staticStr;
+
+    return JSDependentString::new_(cx, base, chars, length);
+}
+
+template <AllowGC allowGC>
+JSFlatString *
+js_NewStringCopyN(ExclusiveContext *cx, const jschar *s, size_t n)
+{
+    if (JSFatInlineString::lengthFits(n))
+        return NewFatInlineString<allowGC>(cx, TwoByteChars(s, n));
+
+    jschar *news = cx->pod_malloc<jschar>(n + 1);
+    if (!news)
+        return nullptr;
+    js_strncpy(news, s, n);
+    news[n] = 0;
+    JSFlatString *str = js_NewString<allowGC>(cx, news, n);
+    if (!str)
+        js_free(news);
+    return str;
+}
+
+template JSFlatString *
+js_NewStringCopyN<CanGC>(ExclusiveContext *cx, const jschar *s, size_t n);
+
+template JSFlatString *
+js_NewStringCopyN<NoGC>(ExclusiveContext *cx, const jschar *s, size_t n);
+
+template <AllowGC allowGC>
+JSFlatString *
+js_NewStringCopyN(ThreadSafeContext *cx, const char *s, size_t n)
+{
+    if (JSFatInlineString::lengthFits(n))
+        return NewFatInlineString<allowGC>(cx, JS::Latin1Chars(s, n));
+
+    jschar *chars = InflateString(cx, s, &n);
+    if (!chars)
+        return nullptr;
+    JSFlatString *str = js_NewString<allowGC>(cx, chars, n);
+    if (!str)
+        js_free(chars);
+    return str;
+}
+
+template JSFlatString *
+js_NewStringCopyN<CanGC>(ThreadSafeContext *cx, const char *s, size_t n);
+
+template JSFlatString *
+js_NewStringCopyN<NoGC>(ThreadSafeContext *cx, const char *s, size_t n);
+
+template <AllowGC allowGC>
+JSFlatString *
+js_NewStringCopyZ(ExclusiveContext *cx, const jschar *s)
+{
+    size_t n = js_strlen(s);
+    if (JSFatInlineString::lengthFits(n))
+        return NewFatInlineString<allowGC>(cx, TwoByteChars(s, n));
+
+    size_t m = (n + 1) * sizeof(jschar);
+    jschar *news = (jschar *) cx->malloc_(m);
+    if (!news)
+        return nullptr;
+    js_memcpy(news, s, m);
+    JSFlatString *str = js_NewString<allowGC>(cx, news, n);
+    if (!str)
+        js_free(news);
+    return str;
+}
+
+template JSFlatString *
+js_NewStringCopyZ<CanGC>(ExclusiveContext *cx, const jschar *s);
+
+template JSFlatString *
+js_NewStringCopyZ<NoGC>(ExclusiveContext *cx, const jschar *s);
+
+template <AllowGC allowGC>
+JSFlatString *
+js_NewStringCopyZ(ThreadSafeContext *cx, const char *s)
+{
+    return js_NewStringCopyN<allowGC>(cx, s, strlen(s));
+}
+
+template JSFlatString *
+js_NewStringCopyZ<CanGC>(ThreadSafeContext *cx, const char *s);
+
+template JSFlatString *
+js_NewStringCopyZ<NoGC>(ThreadSafeContext *cx, const char *s);
+
+const char *
+js_ValueToPrintable(JSContext *cx, const Value &vArg, JSAutoByteString *bytes, bool asSource)
+{
+    RootedValue v(cx, vArg);
+    JSString *str;
+    if (asSource)
+        str = ValueToSource(cx, v);
+    else
+        str = ToString<CanGC>(cx, v);
+    if (!str)
+        return nullptr;
+    str = js_QuoteString(cx, str, 0);
+    if (!str)
+        return nullptr;
+    return bytes->encodeLatin1(cx, str);
+}
+
+template <AllowGC allowGC>
+JSString *
+js::ToStringSlow(ExclusiveContext *cx, typename MaybeRooted<Value, allowGC>::HandleType arg)
+{
+    /* As with ToObjectSlow, callers must verify that |arg| isn't a string. */
+    JS_ASSERT(!arg.isString());
+
+    Value v = arg;
+    if (!v.isPrimitive()) {
+        if (!cx->shouldBeJSContext() || !allowGC)
+            return nullptr;
+        RootedValue v2(cx, v);
+        if (!ToPrimitive(cx->asJSContext(), JSTYPE_STRING, &v2))
+            return nullptr;
+        v = v2;
+    }
+
+    JSString *str;
+    if (v.isString()) {
+        str = v.toString();
+    } else if (v.isInt32()) {
+        str = Int32ToString<allowGC>(cx, v.toInt32());
+    } else if (v.isDouble()) {
+        str = NumberToString<allowGC>(cx, v.toDouble());
+    } else if (v.isBoolean()) {
+        str = js_BooleanToString(cx, v.toBoolean());
+    } else if (v.isNull()) {
+        str = cx->names().null;
+    } else {
+        str = cx->names().undefined;
+    }
+    return str;
+}
+
+template JSString *
+js::ToStringSlow<CanGC>(ExclusiveContext *cx, HandleValue arg);
+
+template JSString *
+js::ToStringSlow<NoGC>(ExclusiveContext *cx, Value arg);
+
+JS_PUBLIC_API(JSString *)
+js::ToStringSlow(JSContext *cx, HandleValue v)
+{
+    return ToStringSlow<CanGC>(cx, v);
+}
+
+JSString *
+js::ValueToSource(JSContext *cx, HandleValue v)
+{
+    JS_CHECK_RECURSION(cx, return nullptr);
+    assertSameCompartment(cx, v);
+
+    if (v.isUndefined())
+        return cx->names().void0;
+    if (v.isString())
+        return StringToSource(cx, v.toString());
+    if (v.isPrimitive()) {
+        /* Special case to preserve negative zero, _contra_ toString. */
+        if (v.isDouble() && IsNegativeZero(v.toDouble())) {
+            /* NB: _ucNstr rather than _ucstr to indicate non-terminated. */
+            static const jschar js_negzero_ucNstr[] = {'-', '0'};
+
+            return js_NewStringCopyN<CanGC>(cx, js_negzero_ucNstr, 2);
+        }
+        return ToString<CanGC>(cx, v);
+    }
+
+    RootedValue fval(cx);
+    RootedObject obj(cx, &v.toObject());
+    if (!JSObject::getProperty(cx, obj, obj, cx->names().toSource, &fval))
+        return nullptr;
+    if (js_IsCallable(fval)) {
+        RootedValue rval(cx);
+        if (!Invoke(cx, ObjectValue(*obj), fval, 0, nullptr, &rval))
+            return nullptr;
+        return ToString<CanGC>(cx, rval);
+    }
+
+    return ObjectToSource(cx, obj);
+}
+
+JSString *
+js::StringToSource(JSContext *cx, JSString *str)
+{
+    return js_QuoteString(cx, str, '"');
+}
+
+bool
+js::EqualStrings(JSContext *cx, JSString *str1, JSString *str2, bool *result)
+{
+    if (str1 == str2) {
+        *result = true;
+        return true;
+    }
+
+    size_t length1 = str1->length();
+    if (length1 != str2->length()) {
+        *result = false;
+        return true;
+    }
+
+    JSLinearString *linear1 = str1->ensureLinear(cx);
+    if (!linear1)
+        return false;
+    JSLinearString *linear2 = str2->ensureLinear(cx);
+    if (!linear2)
+        return false;
+
+    *result = PodEqual(linear1->chars(), linear2->chars(), length1);
+    return true;
+}
+
+bool
+js::EqualStrings(JSLinearString *str1, JSLinearString *str2)
+{
+    if (str1 == str2)
+        return true;
+
+    size_t length1 = str1->length();
+    if (length1 != str2->length())
+        return false;
+
+    return PodEqual(str1->chars(), str2->chars(), length1);
+}
+
+static bool
+CompareStringsImpl(JSContext *cx, JSString *str1, JSString *str2, int32_t *result)
+{
+    JS_ASSERT(str1);
+    JS_ASSERT(str2);
+
+    if (str1 == str2) {
+        *result = 0;
+        return true;
+    }
+
+    const jschar *s1 = str1->getChars(cx);
+    if (!s1)
+        return false;
+
+    const jschar *s2 = str2->getChars(cx);
+    if (!s2)
+        return false;
+
+    *result = CompareChars(s1, str1->length(), s2, str2->length());
+    return true;
+}
+
+bool
+js::CompareStrings(JSContext *cx, JSString *str1, JSString *str2, int32_t *result)
+{
+    return CompareStringsImpl(cx, str1, str2, result);
+}
+
+int32_t
+js::CompareAtoms(JSAtom *atom1, JSAtom *atom2)
+{
+    return CompareChars(atom1->chars(), atom1->length(), atom2->chars(), atom2->length());
+}
+
+bool
+js::StringEqualsAscii(JSLinearString *str, const char *asciiBytes)
+{
+    size_t length = strlen(asciiBytes);
+#ifdef DEBUG
+    for (size_t i = 0; i != length; ++i)
+        JS_ASSERT(unsigned(asciiBytes[i]) <= 127);
+#endif
+    if (length != str->length())
+        return false;
+    const jschar *chars = str->chars();
+    for (size_t i = 0; i != length; ++i) {
+        if (unsigned(asciiBytes[i]) != unsigned(chars[i]))
+            return false;
+    }
+    return true;
+}
+
+size_t
+js_strlen(const jschar *s)
+{
+    const jschar *t;
+
+    for (t = s; *t != 0; t++)
+        continue;
+    return (size_t)(t - s);
+}
+
+int32_t
+js_strcmp(const jschar *lhs, const jschar *rhs)
+{
+    while (true) {
+        if (*lhs != *rhs)
+            return int32_t(*lhs) - int32_t(*rhs);
+        if (*lhs == 0)
+            return 0;
+        ++lhs, ++rhs;
+    }
+}
+
+jschar *
+js_strdup(js::ThreadSafeContext *cx, const jschar *s)
+{
+    size_t n = js_strlen(s);
+    jschar *ret = cx->pod_malloc<jschar>(n + 1);
+    if (!ret)
+        return nullptr;
+    js_strncpy(ret, s, n);
+    ret[n] = '\0';
+    return ret;
+}
+
+jschar *
+js_strchr_limit(const jschar *s, jschar c, const jschar *limit)
+{
+    while (s < limit) {
+        if (*s == c)
+            return (jschar *)s;
+        s++;
+    }
+    return nullptr;
+}
+
+jschar *
+js::InflateString(ThreadSafeContext *cx, const char *bytes, size_t *lengthp)
+{
+    size_t nchars;
+    jschar *chars;
+    size_t nbytes = *lengthp;
+
+    nchars = nbytes;
+    chars = cx->pod_malloc<jschar>(nchars + 1);
+    if (!chars)
+        goto bad;
+    for (size_t i = 0; i < nchars; i++)
+        chars[i] = (unsigned char) bytes[i];
+    *lengthp = nchars;
+    chars[nchars] = 0;
+    return chars;
+
+  bad:
+    // For compatibility with callers of JS_DecodeBytes we must zero lengthp
+    // on errors.
+    *lengthp = 0;
+    return nullptr;
+}
+
+bool
+js::DeflateStringToBuffer(JSContext *maybecx, const jschar *src, size_t srclen,
+                          char *dst, size_t *dstlenp)
+{
+    size_t dstlen = *dstlenp;
+    if (srclen > dstlen) {
+        for (size_t i = 0; i < dstlen; i++)
+            dst[i] = (char) src[i];
+        if (maybecx) {
+            AutoSuppressGC suppress(maybecx);
+            JS_ReportErrorNumber(maybecx, js_GetErrorMessage, nullptr,
+                                 JSMSG_BUFFER_TOO_SMALL);
+        }
+        return false;
+    }
+    for (size_t i = 0; i < srclen; i++)
+        dst[i] = (char) src[i];
+    *dstlenp = srclen;
+    return true;
+}
+
+#define ____ false
+
+/*
+ * Identifier start chars:
+ * -      36:    $
+ * -  65..90: A..Z
+ * -      95:    _
+ * - 97..122: a..z
+ */
+const bool js_isidstart[] = {
+/*       0     1     2     3     4     5     6     7     8     9  */
+/*  0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  1 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  3 */ ____, ____, ____, ____, ____, ____, true, ____, ____, ____,
+/*  4 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  5 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  6 */ ____, ____, ____, ____, ____, true, true, true, true, true,
+/*  7 */ true, true, true, true, true, true, true, true, true, true,
+/*  8 */ true, true, true, true, true, true, true, true, true, true,
+/*  9 */ true, ____, ____, ____, ____, true, ____, true, true, true,
+/* 10 */ true, true, true, true, true, true, true, true, true, true,
+/* 11 */ true, true, true, true, true, true, true, true, true, true,
+/* 12 */ true, true, true, ____, ____, ____, ____, ____
+};
+
+/*
+ * Identifier chars:
+ * -      36:    $
+ * -  48..57: 0..9
+ * -  65..90: A..Z
+ * -      95:    _
+ * - 97..122: a..z
+ */
+const bool js_isident[] = {
+/*       0     1     2     3     4     5     6     7     8     9  */
+/*  0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  1 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  3 */ ____, ____, ____, ____, ____, ____, true, ____, ____, ____,
+/*  4 */ ____, ____, ____, ____, ____, ____, ____, ____, true, true,
+/*  5 */ true, true, true, true, true, true, true, true, ____, ____,
+/*  6 */ ____, ____, ____, ____, ____, true, true, true, true, true,
+/*  7 */ true, true, true, true, true, true, true, true, true, true,
+/*  8 */ true, true, true, true, true, true, true, true, true, true,
+/*  9 */ true, ____, ____, ____, ____, true, ____, true, true, true,
+/* 10 */ true, true, true, true, true, true, true, true, true, true,
+/* 11 */ true, true, true, true, true, true, true, true, true, true,
+/* 12 */ true, true, true, ____, ____, ____, ____, ____
+};
+
+/* Whitespace chars: '\t', '\n', '\v', '\f', '\r', ' '. */
+const bool js_isspace[] = {
+/*       0     1     2     3     4     5     6     7     8     9  */
+/*  0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, true,
+/*  1 */ true, true, true, true, ____, ____, ____, ____, ____, ____,
+/*  2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  3 */ ____, ____, true, ____, ____, ____, ____, ____, ____, ____,
+/*  4 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  5 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  6 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  7 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  8 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  9 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/* 10 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/* 11 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/* 12 */ ____, ____, ____, ____, ____, ____, ____, ____
+};
+
+/*
+ * Uri reserved chars + #:
+ * - 35: #
+ * - 36: $
+ * - 38: &
+ * - 43: +
+ * - 44: ,
+ * - 47: /
+ * - 58: :
+ * - 59: ;
+ * - 61: =
+ * - 63: ?
+ * - 64: @
+ */
+static const bool js_isUriReservedPlusPound[] = {
+/*       0     1     2     3     4     5     6     7     8     9  */
+/*  0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  1 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  3 */ ____, ____, ____, ____, ____, true, true, ____, true, ____,
+/*  4 */ ____, ____, ____, true, true, ____, ____, true, ____, ____,
+/*  5 */ ____, ____, ____, ____, ____, ____, ____, ____, true, true,
+/*  6 */ ____, true, ____, true, true, ____, ____, ____, ____, ____,
+/*  7 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  8 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  9 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/* 10 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/* 11 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/* 12 */ ____, ____, ____, ____, ____, ____, ____, ____
+};
+
+/*
+ * Uri unescaped chars:
+ * -      33: !
+ * -      39: '
+ * -      40: (
+ * -      41: )
+ * -      42: *
+ * -      45: -
+ * -      46: .
+ * -  48..57: 0-9
+ * -  65..90: A-Z
+ * -      95: _
+ * - 97..122: a-z
+ * -     126: ~
+ */
+static const bool js_isUriUnescaped[] = {
+/*       0     1     2     3     4     5     6     7     8     9  */
+/*  0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  1 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____,
+/*  3 */ ____, ____, ____, true, ____, ____, ____, ____, ____, true,
+/*  4 */ true, true, true, ____, ____, true, true, ____, true, true,
+/*  5 */ true, true, true, true, true, true, true, true, ____, ____,
+/*  6 */ ____, ____, ____, ____, ____, true, true, true, true, true,
+/*  7 */ true, true, true, true, true, true, true, true, true, true,
+/*  8 */ true, true, true, true, true, true, true, true, true, true,
+/*  9 */ true, ____, ____, ____, ____, true, ____, true, true, true,
+/* 10 */ true, true, true, true, true, true, true, true, true, true,
+/* 11 */ true, true, true, true, true, true, true, true, true, true,
+/* 12 */ true, true, true, ____, ____, ____, true, ____
+};
+
+#undef ____
+
+#define URI_CHUNK 64U
+
+static inline bool
+TransferBufferToString(StringBuffer &sb, MutableHandleValue rval)
+{
+    JSString *str = sb.finishString();
+    if (!str)
+        return false;
+    rval.setString(str);
+    return true;
+}
+
+/*
+ * ECMA 3, 15.1.3 URI Handling Function Properties
+ *
+ * The following are implementations of the algorithms
+ * given in the ECMA specification for the hidden functions
+ * 'Encode' and 'Decode'.
+ */
+static bool
+Encode(JSContext *cx, Handle<JSLinearString*> str, const bool *unescapedSet,
+       const bool *unescapedSet2, MutableHandleValue rval)
+{
+    static const char HexDigits[] = "0123456789ABCDEF"; /* NB: uppercase */
+
+    size_t length = str->length();
+    if (length == 0) {
+        rval.setString(cx->runtime()->emptyString);
+        return true;
+    }
+
+    const jschar *chars = str->chars();
+    StringBuffer sb(cx);
+    if (!sb.reserve(length))
+        return false;
+    jschar hexBuf[4];
+    hexBuf[0] = '%';
+    hexBuf[3] = 0;
+    for (size_t k = 0; k < length; k++) {
+        jschar c = chars[k];
+        if (c < 128 && (unescapedSet[c] || (unescapedSet2 && unescapedSet2[c]))) {
+            if (!sb.append(c))
+                return false;
+        } else {
+            if ((c >= 0xDC00) && (c <= 0xDFFF)) {
+                JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_BAD_URI, nullptr);
+                return false;
+            }
+            uint32_t v;
+            if (c < 0xD800 || c > 0xDBFF) {
+                v = c;
+            } else {
+                k++;
+                if (k == length) {
+                    JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr,
+                                     JSMSG_BAD_URI, nullptr);
+                    return false;
+                }
+                jschar c2 = chars[k];
+                if ((c2 < 0xDC00) || (c2 > 0xDFFF)) {
+                    JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr,
+                                     JSMSG_BAD_URI, nullptr);
+                    return false;
+                }
+                v = ((c - 0xD800) << 10) + (c2 - 0xDC00) + 0x10000;
+            }
+            uint8_t utf8buf[4];
+            size_t L = js_OneUcs4ToUtf8Char(utf8buf, v);
+            for (size_t j = 0; j < L; j++) {
+                hexBuf[1] = HexDigits[utf8buf[j] >> 4];
+                hexBuf[2] = HexDigits[utf8buf[j] & 0xf];
+                if (!sb.append(hexBuf, 3))
+                    return false;
+            }
+        }
+    }
+
+    return TransferBufferToString(sb, rval);
+}
+
+static bool
+Decode(JSContext *cx, Handle<JSLinearString*> str, const bool *reservedSet, MutableHandleValue rval)
+{
+    size_t length = str->length();
+    if (length == 0) {
+        rval.setString(cx->runtime()->emptyString);
+        return true;
+    }
+
+    const jschar *chars = str->chars();
+    StringBuffer sb(cx);
+    for (size_t k = 0; k < length; k++) {
+        jschar c = chars[k];
+        if (c == '%') {
+            size_t start = k;
+            if ((k + 2) >= length)
+                goto report_bad_uri;
+            if (!JS7_ISHEX(chars[k+1]) || !JS7_ISHEX(chars[k+2]))
+                goto report_bad_uri;
+            uint32_t B = JS7_UNHEX(chars[k+1]) * 16 + JS7_UNHEX(chars[k+2]);
+            k += 2;
+            if (!(B & 0x80)) {
+                c = (jschar)B;
+            } else {
+                int n = 1;
+                while (B & (0x80 >> n))
+                    n++;
+                if (n == 1 || n > 4)
+                    goto report_bad_uri;
+                uint8_t octets[4];
+                octets[0] = (uint8_t)B;
+                if (k + 3 * (n - 1) >= length)
+                    goto report_bad_uri;
+                for (int j = 1; j < n; j++) {
+                    k++;
+                    if (chars[k] != '%')
+                        goto report_bad_uri;
+                    if (!JS7_ISHEX(chars[k+1]) || !JS7_ISHEX(chars[k+2]))
+                        goto report_bad_uri;
+                    B = JS7_UNHEX(chars[k+1]) * 16 + JS7_UNHEX(chars[k+2]);
+                    if ((B & 0xC0) != 0x80)
+                        goto report_bad_uri;
+                    k += 2;
+                    octets[j] = (char)B;
+                }
+                uint32_t v = JS::Utf8ToOneUcs4Char(octets, n);
+                if (v >= 0x10000) {
+                    v -= 0x10000;
+                    if (v > 0xFFFFF)
+                        goto report_bad_uri;
+                    c = (jschar)((v & 0x3FF) + 0xDC00);
+                    jschar H = (jschar)((v >> 10) + 0xD800);
+                    if (!sb.append(H))
+                        return false;
+                } else {
+                    c = (jschar)v;
+                }
+            }
+            if (c < 128 && reservedSet && reservedSet[c]) {
+                if (!sb.append(chars + start, k - start + 1))
+                    return false;
+            } else {
+                if (!sb.append(c))
+                    return false;
+            }
+        } else {
+            if (!sb.append(c))
+                return false;
+        }
+    }
+
+    return TransferBufferToString(sb, rval);
+
+  report_bad_uri:
+    JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_BAD_URI);
+    /* FALL THROUGH */
+
+    return false;
+}
+
+static bool
+str_decodeURI(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    Rooted<JSLinearString*> str(cx, ArgToRootedString(cx, args, 0));
+    if (!str)
+        return false;
+
+    return Decode(cx, str, js_isUriReservedPlusPound, args.rval());
+}
+
+static bool
+str_decodeURI_Component(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    Rooted<JSLinearString*> str(cx, ArgToRootedString(cx, args, 0));
+    if (!str)
+        return false;
+
+    return Decode(cx, str, nullptr, args.rval());
+}
+
+static bool
+str_encodeURI(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    Rooted<JSLinearString*> str(cx, ArgToRootedString(cx, args, 0));
+    if (!str)
+        return false;
+
+    return Encode(cx, str, js_isUriUnescaped, js_isUriReservedPlusPound, args.rval());
+}
+
+static bool
+str_encodeURI_Component(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    Rooted<JSLinearString*> str(cx, ArgToRootedString(cx, args, 0));
+    if (!str)
+        return false;
+
+    return Encode(cx, str, js_isUriUnescaped, nullptr, args.rval());
+}
+
+/*
+ * Convert one UCS-4 char and write it into a UTF-8 buffer, which must be at
+ * least 4 bytes long.  Return the number of UTF-8 bytes of data written.
+ */
+int
+js_OneUcs4ToUtf8Char(uint8_t *utf8Buffer, uint32_t ucs4Char)
+{
+    int utf8Length = 1;
+
+    JS_ASSERT(ucs4Char <= 0x10FFFF);
+    if (ucs4Char < 0x80) {
+        *utf8Buffer = (uint8_t)ucs4Char;
+    } else {
+        int i;
+        uint32_t a = ucs4Char >> 11;
+        utf8Length = 2;
+        while (a) {
+            a >>= 5;
+            utf8Length++;
+        }
+        i = utf8Length;
+        while (--i) {
+            utf8Buffer[i] = (uint8_t)((ucs4Char & 0x3F) | 0x80);
+            ucs4Char >>= 6;
+        }
+        *utf8Buffer = (uint8_t)(0x100 - (1 << (8-utf8Length)) + ucs4Char);
+    }
+    return utf8Length;
+}
+
+size_t
+js::PutEscapedStringImpl(char *buffer, size_t bufferSize, FILE *fp, JSLinearString *str,
+                         uint32_t quote)
+{
+    return PutEscapedStringImpl(buffer, bufferSize, fp, str->chars(),
+                                str->length(), quote);
+}
+
+size_t
+js::PutEscapedStringImpl(char *buffer, size_t bufferSize, FILE *fp, const jschar *chars,
+                         size_t length, uint32_t quote)
+{
+    enum {
+        STOP, FIRST_QUOTE, LAST_QUOTE, CHARS, ESCAPE_START, ESCAPE_MORE
+    } state;
+
+    JS_ASSERT(quote == 0 || quote == '\'' || quote == '"');
+    JS_ASSERT_IF(!buffer, bufferSize == 0);
+    JS_ASSERT_IF(fp, !buffer);
+
+    if (bufferSize == 0)
+        buffer = nullptr;
+    else
+        bufferSize--;
+
+    const jschar *charsEnd = chars + length;
+    size_t n = 0;
+    state = FIRST_QUOTE;
+    unsigned shift = 0;
+    unsigned hex = 0;
+    unsigned u = 0;
+    char c = 0;  /* to quell GCC warnings */
+
+    for (;;) {
+        switch (state) {
+          case STOP:
+            goto stop;
+          case FIRST_QUOTE:
+            state = CHARS;
+            goto do_quote;
+          case LAST_QUOTE:
+            state = STOP;
+          do_quote:
+            if (quote == 0)
+                continue;
+            c = (char)quote;
+            break;
+          case CHARS:
+            if (chars == charsEnd) {
+                state = LAST_QUOTE;
+                continue;
+            }
+            u = *chars++;
+            if (u < ' ') {
+                if (u != 0) {
+                    const char *escape = strchr(js_EscapeMap, (int)u);
+                    if (escape) {
+                        u = escape[1];
+                        goto do_escape;
+                    }
+                }
+                goto do_hex_escape;
+            }
+            if (u < 127) {
+                if (u == quote || u == '\\')
+                    goto do_escape;
+                c = (char)u;
+            } else if (u < 0x100) {
+                goto do_hex_escape;
+            } else {
+                shift = 16;
+                hex = u;
+                u = 'u';
+                goto do_escape;
+            }
+            break;
+          do_hex_escape:
+            shift = 8;
+            hex = u;
+            u = 'x';
+          do_escape:
+            c = '\\';
+            state = ESCAPE_START;
+            break;
+          case ESCAPE_START:
+            JS_ASSERT(' ' <= u && u < 127);
+            c = (char)u;
+            state = ESCAPE_MORE;
+            break;
+          case ESCAPE_MORE:
+            if (shift == 0) {
+                state = CHARS;
+                continue;
+            }
+            shift -= 4;
+            u = 0xF & (hex >> shift);
+            c = (char)(u + (u < 10 ? '0' : 'A' - 10));
+            break;
+        }
+        if (buffer) {
+            JS_ASSERT(n <= bufferSize);
+            if (n != bufferSize) {
+                buffer[n] = c;
+            } else {
+                buffer[n] = '\0';
+                buffer = nullptr;
+            }
+        } else if (fp) {
+            if (fputc(c, fp) < 0)
+                return size_t(-1);
+        }
+        n++;
+    }
+  stop:
+    if (buffer)
+        buffer[n] = '\0';
+    return n;
+}