src/third_party/mozjs/js/src/jsapi.h

/* -*- 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/. */

/* JavaScript API. */

#ifndef jsapi_h
#define jsapi_h

#include "mozilla/FloatingPoint.h"
#include "mozilla/RangedPtr.h"
#include "mozilla/StandardInteger.h"
#include "mozilla/ThreadLocal.h"
#include "mozilla/TypeTraits.h"

#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>

#include "js-config.h"
#include "jsalloc.h"
#include "jspubtd.h"

#include "js/CallArgs.h"
#include "js/CharacterEncoding.h"
#include "js/HashTable.h"
#include "js/RootingAPI.h"
#include "js/Utility.h"
#include "js/Value.h"
#include "js/Vector.h"

#include "starboard/file.h"
#include "nb/memory_scope.h"

/************************************************************************/

namespace JS {

typedef mozilla::RangedPtr<const jschar> CharPtr;

class StableCharPtr : public CharPtr {
  public:
    StableCharPtr(const StableCharPtr &s) : CharPtr(s) {}
    StableCharPtr(const mozilla::RangedPtr<const jschar> &s) : CharPtr(s) {}
    StableCharPtr(const jschar *s, size_t len) : CharPtr(s, len) {}
    StableCharPtr(const jschar *pos, const jschar *start, size_t len)
      : CharPtr(pos, start, len)
    {}
};

#if defined JS_THREADSAFE && defined JS_DEBUG

class JS_PUBLIC_API(AutoCheckRequestDepth)
{
    JSContext *cx;
  public:
    AutoCheckRequestDepth(JSContext *cx);
    ~AutoCheckRequestDepth();
};

# define CHECK_REQUEST(cx) \
    JS::AutoCheckRequestDepth _autoCheckRequestDepth(cx)

#else

# define CHECK_REQUEST(cx) \
    ((void) 0)

#endif /* JS_THREADSAFE && JS_DEBUG */

#ifdef JS_DEBUG
/*
 * Assert that we're not doing GC on cx, that we're in a request as
 * needed, and that the compartments for cx and v are correct.
 * Also check that GC would be safe at this point.
 */
JS_PUBLIC_API(void)
AssertArgumentsAreSane(JSContext *cx, const Value &v);
#else
inline void AssertArgumentsAreSane(JSContext *cx, const Value &v) {
    /* Do nothing */
}
#endif /* JS_DEBUG */

class JS_PUBLIC_API(AutoGCRooter) {
  public:
    AutoGCRooter(JSContext *cx, ptrdiff_t tag);

    ~AutoGCRooter() {
        JS_ASSERT(this == *stackTop);
        *stackTop = down;
    }

    /* Implemented in gc/RootMarking.cpp. */
    inline void trace(JSTracer *trc);
    static void traceAll(JSTracer *trc);
    static void traceAllWrappers(JSTracer *trc);

  protected:
    AutoGCRooter * const down;

    /*
     * Discriminates actual subclass of this being used.  If non-negative, the
     * subclass roots an array of values of the length stored in this field.
     * If negative, meaning is indicated by the corresponding value in the enum
     * below.  Any other negative value indicates some deeper problem such as
     * memory corruption.
     */
    ptrdiff_t tag_;

    enum {
        VALARRAY =     -2, /* js::AutoValueArray */
        PARSER =       -3, /* js::frontend::Parser */
        SHAPEVECTOR =  -4, /* js::AutoShapeVector */
        IDARRAY =      -6, /* js::AutoIdArray */
        DESCRIPTORS =  -7, /* js::AutoPropDescArrayRooter */
        ID =           -9, /* js::AutoIdRooter */
        VALVECTOR =   -10, /* js::AutoValueVector */
        DESCRIPTOR =  -11, /* js::AutoPropertyDescriptorRooter */
        STRING =      -12, /* js::AutoStringRooter */
        IDVECTOR =    -13, /* js::AutoIdVector */
        OBJVECTOR =   -14, /* js::AutoObjectVector */
        STRINGVECTOR =-15, /* js::AutoStringVector */
        SCRIPTVECTOR =-16, /* js::AutoScriptVector */
        NAMEVECTOR =  -17, /* js::AutoNameVector */
        HASHABLEVALUE=-18, /* js::HashableValue */
        IONMASM =     -19, /* js::jit::MacroAssembler */
        IONALLOC =    -20, /* js::jit::AutoTempAllocatorRooter */
        WRAPVECTOR =  -21, /* js::AutoWrapperVector */
        WRAPPER =     -22, /* js::AutoWrapperRooter */
        OBJOBJHASHMAP=-23, /* js::AutoObjectObjectHashMap */
        OBJU32HASHMAP=-24, /* js::AutoObjectUnsigned32HashMap */
        OBJHASHSET =  -25, /* js::AutoObjectHashSet */
        JSONPARSER =  -26, /* js::JSONParser */
        CUSTOM =      -27  /* js::CustomAutoRooter */
    };

  private:
    AutoGCRooter ** const stackTop;

    /* No copy or assignment semantics. */
    AutoGCRooter(AutoGCRooter &ida) MOZ_DELETE;
    void operator=(AutoGCRooter &ida) MOZ_DELETE;
};

class AutoStringRooter : private AutoGCRooter {
  public:
    AutoStringRooter(JSContext *cx, JSString *str = NULL
                     MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, STRING), str_(str)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    void setString(JSString *str) {
        str_ = str;
    }

    JSString * string() const {
        return str_;
    }

    JSString ** addr() {
        return &str_;
    }

    JSString * const * addr() const {
        return &str_;
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

  private:
    JSString *str_;
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

class AutoArrayRooter : private AutoGCRooter {
  public:
    AutoArrayRooter(JSContext *cx, size_t len, Value *vec
                    MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, len), array(vec), skip(cx, array, len)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
        JS_ASSERT(tag_ >= 0);
    }

    void changeLength(size_t newLength) {
        tag_ = ptrdiff_t(newLength);
        JS_ASSERT(tag_ >= 0);
    }

    void changeArray(Value *newArray, size_t newLength) {
        changeLength(newLength);
        array = newArray;
    }

    Value *array;

    MutableHandleValue handleAt(size_t i)
    {
        JS_ASSERT(i < size_t(tag_));
        return MutableHandleValue::fromMarkedLocation(&array[i]);
    }
    HandleValue handleAt(size_t i) const
    {
        JS_ASSERT(i < size_t(tag_));
        return HandleValue::fromMarkedLocation(&array[i]);
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

  private:
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

    js::SkipRoot skip;
};

template<class T>
class AutoVectorRooter : protected AutoGCRooter
{
  public:
    explicit AutoVectorRooter(JSContext *cx, ptrdiff_t tag
                              MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, tag), vector(cx), vectorRoot(cx, &vector)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    typedef T ElementType;

    size_t length() const { return vector.length(); }
    bool empty() const { return vector.empty(); }

    bool append(const T &v) { return vector.append(v); }
    bool append(const AutoVectorRooter<T> &other) {
        return vector.append(other.vector);
    }

    bool insert(T *p, const T &val) { return vector.insert(p, val); }

    /* For use when space has already been reserved. */
    void infallibleAppend(const T &v) { vector.infallibleAppend(v); }

    void popBack() { vector.popBack(); }
    T popCopy() { return vector.popCopy(); }

    bool growBy(size_t inc) {
        size_t oldLength = vector.length();
        if (!vector.growByUninitialized(inc))
            return false;
        makeRangeGCSafe(oldLength);
        return true;
    }

    bool resize(size_t newLength) {
        TRACK_MEMORY_SCOPE("Javascript");
        size_t oldLength = vector.length();
        if (newLength <= oldLength) {
            vector.shrinkBy(oldLength - newLength);
            return true;
        }
        if (!vector.growByUninitialized(newLength - oldLength))
            return false;
        makeRangeGCSafe(oldLength);
        return true;
    }

    void clear() { vector.clear(); }

    bool reserve(size_t newLength) {
        return vector.reserve(newLength);
    }

    T &operator[](size_t i) { return vector[i]; }
    const T &operator[](size_t i) const { return vector[i]; }

    JS::MutableHandle<T> handleAt(size_t i) { return JS::MutableHandle<T>::fromMarkedLocation(&vector[i]); }
    JS::Handle<T> handleAt(size_t i) const { return JS::Handle<T>::fromMarkedLocation(&vector[i]); }

    const T *begin() const { return vector.begin(); }
    T *begin() { return vector.begin(); }

    const T *end() const { return vector.end(); }
    T *end() { return vector.end(); }

    const T &back() const { return vector.back(); }

    friend void AutoGCRooter::trace(JSTracer *trc);

  private:
    void makeRangeGCSafe(size_t oldLength) {
        T *t = vector.begin() + oldLength;
        for (size_t i = oldLength; i < vector.length(); ++i, ++t)
            memset(t, 0, sizeof(T));
    }

    typedef js::Vector<T, 8> VectorImpl;
    VectorImpl vector;

    /* Prevent overwriting of inline elements in vector. */
    js::SkipRoot vectorRoot;

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

template<class Key, class Value>
class AutoHashMapRooter : protected AutoGCRooter
{
  private:
    typedef js::HashMap<Key, Value> HashMapImpl;

  public:
    explicit AutoHashMapRooter(JSContext *cx, ptrdiff_t tag
                               MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, tag), map(cx)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    typedef Key KeyType;
    typedef Value ValueType;
    typedef typename HashMapImpl::Lookup Lookup;
    typedef typename HashMapImpl::Ptr Ptr;
    typedef typename HashMapImpl::AddPtr AddPtr;

    bool init(uint32_t len = 16) {
        return map.init(len);
    }
    bool initialized() const {
        return map.initialized();
    }
    Ptr lookup(const Lookup &l) const {
        return map.lookup(l);
    }
    void remove(Ptr p) {
        map.remove(p);
    }
    AddPtr lookupForAdd(const Lookup &l) const {
        return map.lookupForAdd(l);
    }

    template<typename KeyInput, typename ValueInput>
    bool add(AddPtr &p, const KeyInput &k, const ValueInput &v) {
        return map.add(p, k, v);
    }

    bool add(AddPtr &p, const Key &k) {
        return map.add(p, k);
    }

    template<typename KeyInput, typename ValueInput>
    bool relookupOrAdd(AddPtr &p, const KeyInput &k, const ValueInput &v) {
        return map.relookupOrAdd(p, k, v);
    }

    typedef typename HashMapImpl::Range Range;
    Range all() const {
        return map.all();
    }

    typedef typename HashMapImpl::Enum Enum;

    void clear() {
        map.clear();
    }

    void finish() {
        map.finish();
    }

    bool empty() const {
        return map.empty();
    }

    uint32_t count() const {
        return map.count();
    }

    size_t capacity() const {
        return map.capacity();
    }

    size_t sizeOfExcludingThis(JSMallocSizeOfFun mallocSizeOf) const {
        return map.sizeOfExcludingThis(mallocSizeOf);
    }
    size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf) const {
        return map.sizeOfIncludingThis(mallocSizeOf);
    }

    unsigned generation() const {
        return map.generation();
    }

    /************************************************** Shorthand operations */

    bool has(const Lookup &l) const {
        return map.has(l);
    }

    template<typename KeyInput, typename ValueInput>
    bool put(const KeyInput &k, const ValueInput &v) {
        return map.put(k, v);
    }

    template<typename KeyInput, typename ValueInput>
    bool putNew(const KeyInput &k, const ValueInput &v) {
        return map.putNew(k, v);
    }

    Ptr lookupWithDefault(const Key &k, const Value &defaultValue) {
        return map.lookupWithDefault(k, defaultValue);
    }

    void remove(const Lookup &l) {
        map.remove(l);
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

  private:
    AutoHashMapRooter(const AutoHashMapRooter &hmr) MOZ_DELETE;
    AutoHashMapRooter &operator=(const AutoHashMapRooter &hmr) MOZ_DELETE;

    HashMapImpl map;

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

template<class T>
class AutoHashSetRooter : protected AutoGCRooter
{
  private:
    typedef js::HashSet<T> HashSetImpl;

  public:
    explicit AutoHashSetRooter(JSContext *cx, ptrdiff_t tag
                               MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, tag), set(cx)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    typedef typename HashSetImpl::Lookup Lookup;
    typedef typename HashSetImpl::Ptr Ptr;
    typedef typename HashSetImpl::AddPtr AddPtr;

    bool init(uint32_t len = 16) {
        return set.init(len);
    }
    bool initialized() const {
        return set.initialized();
    }
    Ptr lookup(const Lookup &l) const {
        return set.lookup(l);
    }
    void remove(Ptr p) {
        set.remove(p);
    }
    AddPtr lookupForAdd(const Lookup &l) const {
        return set.lookupForAdd(l);
    }

    bool add(AddPtr &p, const T &t) {
        return set.add(p, t);
    }

    bool relookupOrAdd(AddPtr &p, const Lookup &l, const T &t) {
        return set.relookupOrAdd(p, l, t);
    }

    typedef typename HashSetImpl::Range Range;
    Range all() const {
        return set.all();
    }

    typedef typename HashSetImpl::Enum Enum;

    void clear() {
        set.clear();
    }

    void finish() {
        set.finish();
    }

    bool empty() const {
        return set.empty();
    }

    uint32_t count() const {
        return set.count();
    }

    size_t capacity() const {
        return set.capacity();
    }

    size_t sizeOfExcludingThis(JSMallocSizeOfFun mallocSizeOf) const {
        return set.sizeOfExcludingThis(mallocSizeOf);
    }
    size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf) const {
        return set.sizeOfIncludingThis(mallocSizeOf);
    }

    unsigned generation() const {
        return set.generation();
    }

    /************************************************** Shorthand operations */

    bool has(const Lookup &l) const {
        return set.has(l);
    }

    bool put(const T &t) {
        return set.put(t);
    }

    bool putNew(const T &t) {
        return set.putNew(t);
    }

    void remove(const Lookup &l) {
        set.remove(l);
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

  private:
    AutoHashSetRooter(const AutoHashSetRooter &hmr) MOZ_DELETE;
    AutoHashSetRooter &operator=(const AutoHashSetRooter &hmr) MOZ_DELETE;

    HashSetImpl set;

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

class MOZ_STACK_CLASS AutoValueVector : public AutoVectorRooter<Value>
{
  public:
    explicit AutoValueVector(JSContext *cx
                             MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
        : AutoVectorRooter<Value>(cx, VALVECTOR)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

class AutoIdVector : public AutoVectorRooter<jsid>
{
  public:
    explicit AutoIdVector(JSContext *cx
                          MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
        : AutoVectorRooter<jsid>(cx, IDVECTOR)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

class AutoObjectVector : public AutoVectorRooter<JSObject *>
{
  public:
    explicit AutoObjectVector(JSContext *cx
                              MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
        : AutoVectorRooter<JSObject *>(cx, OBJVECTOR)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

class AutoScriptVector : public AutoVectorRooter<JSScript *>
{
  public:
    explicit AutoScriptVector(JSContext *cx
                              MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
        : AutoVectorRooter<JSScript *>(cx, SCRIPTVECTOR)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

/*
 * Cutsom rooting behavior for internal and external clients.
 */
class JS_PUBLIC_API(CustomAutoRooter) : private AutoGCRooter
{
  public:
    explicit CustomAutoRooter(JSContext *cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, CUSTOM)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

  protected:
    /* Supplied by derived class to trace roots. */
    virtual void trace(JSTracer *trc) = 0;

  private:
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

/* Returns true if |v| is considered an acceptable this-value. */
typedef bool (*IsAcceptableThis)(const Value &v);

/*
 * Implements the guts of a method; guaranteed to be provided an acceptable
 * this-value, as determined by a corresponding IsAcceptableThis method.
 */
typedef bool (*NativeImpl)(JSContext *cx, CallArgs args);

namespace detail {

/* DON'T CALL THIS DIRECTLY.  It's for use only by CallNonGenericMethod! */
extern JS_PUBLIC_API(bool)
CallMethodIfWrapped(JSContext *cx, IsAcceptableThis test, NativeImpl impl, CallArgs args);

} /* namespace detail */

/*
 * Methods usually act upon |this| objects only from a single global object and
 * compartment.  Sometimes, however, a method must act upon |this| values from
 * multiple global objects or compartments.  In such cases the |this| value a
 * method might see will be wrapped, such that various access to the object --
 * to its class, its private data, its reserved slots, and so on -- will not
 * work properly without entering that object's compartment.  This method
 * implements a solution to this problem.
 *
 * To implement a method that accepts |this| values from multiple compartments,
 * define two functions.  The first function matches the IsAcceptableThis type
 * and indicates whether the provided value is an acceptable |this| for the
 * method; it must be a pure function only of its argument.
 *
 *   static JSClass AnswerClass = { ... };
 *
 *   static bool
 *   IsAnswerObject(const Value &v)
 *   {
 *       if (!v.isObject())
 *           return false;
 *       return JS_GetClass(&v.toObject()) == &AnswerClass;
 *   }
 *
 * The second function implements the NativeImpl signature and defines the
 * behavior of the method when it is provided an acceptable |this| value.
 * Aside from some typing niceties -- see the CallArgs interface for details --
 * its interface is the same as that of JSNative.
 *
 *   static bool
 *   answer_getAnswer_impl(JSContext *cx, JS::CallArgs args)
 *   {
 *       args.rval().setInt32(42);
 *       return true;
 *   }
 *
 * The implementation function is guaranteed to be called *only* with a |this|
 * value which is considered acceptable.
 *
 * Now to implement the actual method, write a JSNative that calls the method
 * declared below, passing the appropriate template and runtime arguments.
 *
 *   static JSBool
 *   answer_getAnswer(JSContext *cx, unsigned argc, JS::Value *vp)
 *   {
 *       JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
 *       return JS::CallNonGenericMethod<IsAnswerObject, answer_getAnswer_impl>(cx, args);
 *   }
 *
 * Note that, because they are used as template arguments, the predicate
 * and implementation functions must have external linkage. (This is
 * unfortunate, but GCC wasn't inlining things as one would hope when we
 * passed them as function arguments.)
 *
 * JS::CallNonGenericMethod will test whether |args.thisv()| is acceptable.  If
 * it is, it will call the provided implementation function, which will return
 * a value and indicate success.  If it is not, it will attempt to unwrap
 * |this| and call the implementation function on the unwrapped |this|.  If
 * that succeeds, all well and good.  If it doesn't succeed, a TypeError will
 * be thrown.
 *
 * Note: JS::CallNonGenericMethod will only work correctly if it's called in
 *       tail position in a JSNative.  Do not call it from any other place.
 */
template<IsAcceptableThis Test, NativeImpl Impl>
JS_ALWAYS_INLINE bool
CallNonGenericMethod(JSContext *cx, CallArgs args)
{
    const Value &thisv = args.thisv();
    if (Test(thisv))
        return Impl(cx, args);

    return detail::CallMethodIfWrapped(cx, Test, Impl, args);
}

JS_ALWAYS_INLINE bool
CallNonGenericMethod(JSContext *cx, IsAcceptableThis Test, NativeImpl Impl, CallArgs args)
{
    TRACK_MEMORY_SCOPE("Javascript");
    const Value &thisv = args.thisv();
    if (Test(thisv))
        return Impl(cx, args);

    return detail::CallMethodIfWrapped(cx, Test, Impl, args);
}

}  /* namespace JS */

/************************************************************************/

/* JSClass operation signatures. */

/*
 * Add or get a property named by id in obj.  Note the jsid id type -- id may
 * be a string (Unicode property identifier) or an int (element index).  The
 * *vp out parameter, on success, is the new property value after the action.
 */
typedef JSBool
(* JSPropertyOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, JS::MutableHandle<JS::Value> vp);

/*
 * Set a property named by id in obj, treating the assignment as strict
 * mode code if strict is true. Note the jsid id type -- id may be a string
 * (Unicode property identifier) or an int (element index). The *vp out
 * parameter, on success, is the new property value after the
 * set.
 */
typedef JSBool
(* JSStrictPropertyOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, JSBool strict, JS::MutableHandle<JS::Value> vp);

/*
 * Delete a property named by id in obj.
 *
 * If an error occurred, return false as per normal JSAPI error practice.
 *
 * If no error occurred, but the deletion attempt wasn't allowed (perhaps
 * because the property was non-configurable), set *succeeded to false and
 * return true.  This will cause |delete obj[id]| to evaluate to false in
 * non-strict mode code, and to throw a TypeError in strict mode code.
 *
 * If no error occurred and the deletion wasn't disallowed (this is *not* the
 * same as saying that a deletion actually occurred -- deleting a non-existent
 * property, or an inherited property, is allowed -- it's just pointless),
 * set *succeeded to true and return true.
 */
typedef JSBool
(* JSDeletePropertyOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, JSBool *succeeded);

/*
 * This function type is used for callbacks that enumerate the properties of
 * a JSObject.  The behavior depends on the value of enum_op:
 *
 *  JSENUMERATE_INIT
 *    A new, opaque iterator state should be allocated and stored in *statep.
 *    (You can use PRIVATE_TO_JSVAL() to tag the pointer to be stored).
 *
 *    The number of properties that will be enumerated should be returned as
 *    an integer jsval in *idp, if idp is non-null, and provided the number of
 *    enumerable properties is known.  If idp is non-null and the number of
 *    enumerable properties can't be computed in advance, *idp should be set
 *    to JSVAL_ZERO.
 *
 *  JSENUMERATE_INIT_ALL
 *    Used identically to JSENUMERATE_INIT, but exposes all properties of the
 *    object regardless of enumerability.
 *
 *  JSENUMERATE_NEXT
 *    A previously allocated opaque iterator state is passed in via statep.
 *    Return the next jsid in the iteration using *idp.  The opaque iterator
 *    state pointed at by statep is destroyed and *statep is set to JSVAL_NULL
 *    if there are no properties left to enumerate.
 *
 *  JSENUMERATE_DESTROY
 *    Destroy the opaque iterator state previously allocated in *statep by a
 *    call to this function when enum_op was JSENUMERATE_INIT or
 *    JSENUMERATE_INIT_ALL.
 *
 * The return value is used to indicate success, with a value of JS_FALSE
 * indicating failure.
 */
typedef JSBool
(* JSNewEnumerateOp)(JSContext *cx, JS::Handle<JSObject*> obj, JSIterateOp enum_op,
                     JS::MutableHandle<JS::Value> statep, JS::MutableHandleId idp);

/*
 * The old-style JSClass.enumerate op should define all lazy properties not
 * yet reflected in obj.
 */
typedef JSBool
(* JSEnumerateOp)(JSContext *cx, JS::Handle<JSObject*> obj);

/*
 * Resolve a lazy property named by id in obj by defining it directly in obj.
 * Lazy properties are those reflected from some peer native property space
 * (e.g., the DOM attributes for a given node reflected as obj) on demand.
 *
 * JS looks for a property in an object, and if not found, tries to resolve
 * the given id.  If resolve succeeds, the engine looks again in case resolve
 * defined obj[id].  If no such property exists directly in obj, the process
 * is repeated with obj's prototype, etc.
 *
 * NB: JSNewResolveOp provides a cheaper way to resolve lazy properties.
 */
typedef JSBool
(* JSResolveOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id);

/*
 * Like JSResolveOp, but flags provide contextual information as follows:
 *
 *  JSRESOLVE_ASSIGNING   obj[id] is on the left-hand side of an assignment
 *
 * The *objp out parameter, on success, should be null to indicate that id
 * was not resolved; and non-null, referring to obj or one of its prototypes,
 * if id was resolved.  The hook may assume *objp is null on entry.
 *
 * This hook instead of JSResolveOp is called via the JSClass.resolve member
 * if JSCLASS_NEW_RESOLVE is set in JSClass.flags.
 */
typedef JSBool
(* JSNewResolveOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, unsigned flags,
                   JS::MutableHandleObject objp);

/*
 * Convert obj to the given type, returning true with the resulting value in
 * *vp on success, and returning false on error or exception.
 */
typedef JSBool
(* JSConvertOp)(JSContext *cx, JS::Handle<JSObject*> obj, JSType type,
                JS::MutableHandle<JS::Value> vp);

typedef struct JSFreeOp JSFreeOp;

struct JSFreeOp {
  private:
    JSRuntime   *runtime_;

  protected:
    JSFreeOp(JSRuntime *rt)
      : runtime_(rt) { }

  public:
    JSRuntime *runtime() const {
        return runtime_;
    }
};

/*
 * Finalize obj, which the garbage collector has determined to be unreachable
 * from other live objects or from GC roots.  Obviously, finalizers must never
 * store a reference to obj.
 */
typedef void
(* JSFinalizeOp)(JSFreeOp *fop, JSObject *obj);

/*
 * Finalizes external strings created by JS_NewExternalString.
 */
typedef struct JSStringFinalizer JSStringFinalizer;

struct JSStringFinalizer {
    void (*finalize)(const JSStringFinalizer *fin, jschar *chars);
};

/*
 * JSClass.checkAccess type: check whether obj[id] may be accessed per mode,
 * returning false on error/exception, true on success with obj[id]'s last-got
 * value in *vp, and its attributes in *attrsp.  As for JSPropertyOp above, id
 * is either a string or an int jsval.
 */
typedef JSBool
(* JSCheckAccessOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id,
                    JSAccessMode mode, JS::MutableHandle<JS::Value> vp);

/*
 * Check whether v is an instance of obj.  Return false on error or exception,
 * true on success with JS_TRUE in *bp if v is an instance of obj, JS_FALSE in
 * *bp otherwise.
 */
typedef JSBool
(* JSHasInstanceOp)(JSContext *cx, JS::Handle<JSObject*> obj, JS::MutableHandle<JS::Value> vp,
                    JSBool *bp);

/*
 * Function type for trace operation of the class called to enumerate all
 * traceable things reachable from obj's private data structure. For each such
 * thing, a trace implementation must call one of the JS_Call*Tracer variants
 * on the thing.
 *
 * JSTraceOp implementation can assume that no other threads mutates object
 * state. It must not change state of the object or corresponding native
 * structures. The only exception for this rule is the case when the embedding
 * needs a tight integration with GC. In that case the embedding can check if
 * the traversal is a part of the marking phase through calling
 * JS_IsGCMarkingTracer and apply a special code like emptying caches or
 * marking its native structures.
 */
typedef void
(* JSTraceOp)(JSTracer *trc, JSObject *obj);

/*
 * Callback that JSTraceOp implementation can provide to return a string
 * describing the reference traced with JS_CallTracer.
 */
typedef void
(* JSTraceNamePrinter)(JSTracer *trc, char *buf, size_t bufsize);

typedef JSObject *
(* JSWeakmapKeyDelegateOp)(JSObject *obj);

/* Callbacks and their arguments. */

typedef enum JSContextOp {
    JSCONTEXT_NEW,
    JSCONTEXT_DESTROY
} JSContextOp;

/*
 * The possible values for contextOp when the runtime calls the callback are:
 *   JSCONTEXT_NEW      JS_NewContext successfully created a new JSContext
 *                      instance. The callback can initialize the instance as
 *                      required. If the callback returns false, the instance
 *                      will be destroyed and JS_NewContext returns null. In
 *                      this case the callback is not called again.
 *   JSCONTEXT_DESTROY  One of JS_DestroyContext* methods is called. The
 *                      callback may perform its own cleanup and must always
 *                      return true.
 *   Any other value    For future compatibility the callback must do nothing
 *                      and return true in this case.
 */
typedef JSBool
(* JSContextCallback)(JSContext *cx, unsigned contextOp);

typedef enum JSGCStatus {
    JSGC_BEGIN,
    JSGC_END
} JSGCStatus;

typedef void
(* JSGCCallback)(JSRuntime *rt, JSGCStatus status);

typedef enum JSFinalizeStatus {
    /*
     * Called when preparing to sweep a group of compartments, before anything
     * has been swept.  The collector will not yield to the mutator before
     * calling the callback with JSFINALIZE_GROUP_END status.
     */
    JSFINALIZE_GROUP_START,

    /*
     * Called when preparing to sweep a group of compartments. Weak references
     * to unmarked things have been removed and things that are not swept
     * incrementally have been finalized at this point.  The collector may yield
     * to the mutator after this point.
     */
    JSFINALIZE_GROUP_END,

    /*
     * Called at the end of collection when everything has been swept.
     */
    JSFINALIZE_COLLECTION_END
} JSFinalizeStatus;

typedef void
(* JSFinalizeCallback)(JSFreeOp *fop, JSFinalizeStatus status, JSBool isCompartment);

/*
 * Generic trace operation that calls JS_CallTracer on each traceable thing
 * stored in data.
 */
typedef void
(* JSTraceDataOp)(JSTracer *trc, void *data);

typedef JSBool
(* JSOperationCallback)(JSContext *cx);

typedef void
(* JSErrorReporter)(JSContext *cx, const char *message, JSErrorReport *report);

#ifdef MOZ_TRACE_JSCALLS
typedef void
(* JSFunctionCallback)(const JSFunction *fun,
                       const JSScript *scr,
                       const JSContext *cx,
                       int entering);
#endif

/*
 * Possible exception types. These types are part of a JSErrorFormatString
 * structure. They define which error to throw in case of a runtime error.
 * JSEXN_NONE marks an unthrowable error.
 */
typedef enum JSExnType {
    JSEXN_NONE = -1,
      JSEXN_ERR,
        JSEXN_INTERNALERR,
        JSEXN_EVALERR,
        JSEXN_RANGEERR,
        JSEXN_REFERENCEERR,
        JSEXN_SYNTAXERR,
        JSEXN_TYPEERR,
        JSEXN_URIERR,
        JSEXN_LIMIT
} JSExnType;

typedef struct JSErrorFormatString {
    /* The error format string in ASCII. */
    const char *format;

    /* The number of arguments to expand in the formatted error message. */
    uint16_t argCount;

    /* One of the JSExnType constants above. */
    int16_t exnType;
} JSErrorFormatString;

typedef const JSErrorFormatString *
(* JSErrorCallback)(void *userRef, const char *locale,
                    const unsigned errorNumber);

typedef JSBool
(* JSLocaleToUpperCase)(JSContext *cx, JS::Handle<JSString*> src,
                        JS::MutableHandle<JS::Value> rval);

typedef JSBool
(* JSLocaleToLowerCase)(JSContext *cx, JS::Handle<JSString*> src,
                        JS::MutableHandle<JS::Value> rval);

typedef JSBool
(* JSLocaleCompare)(JSContext *cx, JS::Handle<JSString*> src1, JS::Handle<JSString*> src2,
                    JS::MutableHandle<JS::Value> rval);

typedef JSBool
(* JSLocaleToUnicode)(JSContext *cx, const char *src, JS::MutableHandle<JS::Value> rval);

/*
 * Security protocol types.
 */

typedef void
(* JSDestroyPrincipalsOp)(JSPrincipals *principals);

/*
 * Used to check if a CSP instance wants to disable eval() and friends.
 * See js_CheckCSPPermitsJSAction() in jsobj.
 */
typedef JSBool
(* JSCSPEvalChecker)(JSContext *cx);

/*
 * Callback used to ask the embedding for the cross compartment wrapper handler
 * that implements the desired prolicy for this kind of object in the
 * destination compartment. |obj| is the object to be wrapped. If |existing| is
 * non-NULL, it will point to an existing wrapper object that should be re-used
 * if possible. |existing| is guaranteed to be a cross-compartment wrapper with
 * a lazily-defined prototype and the correct global. It is guaranteed not to
 * wrap a function.
 */
typedef JSObject *
(* JSWrapObjectCallback)(JSContext *cx, JS::HandleObject existing, JS::HandleObject obj,
                         JS::HandleObject proto, JS::HandleObject parent,
                         unsigned flags);

/*
 * Callback used by the wrap hook to ask the embedding to prepare an object
 * for wrapping in a context. This might include unwrapping other wrappers
 * or even finding a more suitable object for the new compartment.
 */
typedef JSObject *
(* JSPreWrapCallback)(JSContext *cx, JS::HandleObject scope, JS::HandleObject obj,
                      unsigned flags);

/*
 * Callback used when wrapping determines that the underlying object is already
 * in the compartment for which it is being wrapped. This allows consumers to
 * maintain same-compartment wrapping invariants.
 *
 * |obj| is guaranteed to be same-compartment as |cx|, but it may (or may not)
 * be a security or cross-compartment wrapper. This is an unfortunate contract,
 * but is important for to avoid unnecessarily recomputing every cross-
 * compartment wrapper that gets passed to wrap.
 */
typedef JSObject *
(* JSSameCompartmentWrapObjectCallback)(JSContext *cx, JS::HandleObject obj);

typedef void
(* JSDestroyCompartmentCallback)(JSFreeOp *fop, JSCompartment *compartment);

typedef void
(* JSZoneCallback)(JS::Zone *zone);

typedef void
(* JSCompartmentNameCallback)(JSRuntime *rt, JSCompartment *compartment,
                              char *buf, size_t bufsize);

/*
 * Read structured data from the reader r. This hook is used to read a value
 * previously serialized by a call to the WriteStructuredCloneOp hook.
 *
 * tag and data are the pair of uint32_t values from the header. The callback
 * may use the JS_Read* APIs to read any other relevant parts of the object
 * from the reader r. closure is any value passed to the JS_ReadStructuredClone
 * function. Return the new object on success, NULL on error/exception.
 */
typedef JSObject *(*ReadStructuredCloneOp)(JSContext *cx, JSStructuredCloneReader *r,
                                           uint32_t tag, uint32_t data, void *closure);

/*
 * Structured data serialization hook. The engine can write primitive values,
 * Objects, Arrays, Dates, RegExps, TypedArrays, and ArrayBuffers. Any other
 * type of object requires application support. This callback must first use
 * the JS_WriteUint32Pair API to write an object header, passing a value
 * greater than JS_SCTAG_USER to the tag parameter. Then it can use the
 * JS_Write* APIs to write any other relevant parts of the value v to the
 * writer w. closure is any value passed to the JS_WriteStructuredCLone function.
 *
 * Return true on success, false on error/exception.
 */
typedef JSBool (*WriteStructuredCloneOp)(JSContext *cx, JSStructuredCloneWriter *w,
                                         JS::Handle<JSObject*> obj, void *closure);

/*
 * This is called when JS_WriteStructuredClone is given an invalid transferable.
 * To follow HTML5, the application must throw a DATA_CLONE_ERR DOMException
 * with error set to one of the JS_SCERR_* values.
 */
typedef void (*StructuredCloneErrorOp)(JSContext *cx, uint32_t errorid);

/************************************************************************/

/*
 * JS constants. For efficiency, prefer predicates (e.g. v.isNull()) and
 * constructing values from scratch (e.g. Int32Value(0)).  These constants are
 * stored in memory and initialized at startup, so testing against them and
 * using them requires memory loads and will be correspondingly slow.
 */
extern JS_PUBLIC_DATA(const jsval) JSVAL_NULL;
extern JS_PUBLIC_DATA(const jsval) JSVAL_ZERO;
extern JS_PUBLIC_DATA(const jsval) JSVAL_ONE;
extern JS_PUBLIC_DATA(const jsval) JSVAL_FALSE;
extern JS_PUBLIC_DATA(const jsval) JSVAL_TRUE;
extern JS_PUBLIC_DATA(const jsval) JSVAL_VOID;

static JS_ALWAYS_INLINE jsval
JS_NumberValue(double d)
{
    int32_t i;
    d = JS::CanonicalizeNaN(d);
    if (mozilla::DoubleIsInt32(d, &i))
        return INT_TO_JSVAL(i);
    return DOUBLE_TO_JSVAL(d);
}

/************************************************************************/

/*
 * A jsid is an identifier for a property or method of an object which is
 * either a 31-bit signed integer, interned string or object.  Also, there is
 * an additional jsid value, JSID_VOID, which does not occur in JS scripts but
 * may be used to indicate the absence of a valid jsid.
 *
 * A jsid is not implicitly convertible to or from a jsval; JS_ValueToId or
 * JS_IdToValue must be used instead.
 */

#define JSID_TYPE_STRING                 0x0
#define JSID_TYPE_INT                    0x1
#define JSID_TYPE_VOID                   0x2
#define JSID_TYPE_OBJECT                 0x4
#define JSID_TYPE_MASK                   0x7

/*
 * Avoid using canonical 'id' for jsid parameters since this is a magic word in
 * Objective-C++ which, apparently, wants to be able to #include jsapi.h.
 */
#define id iden

static JS_ALWAYS_INLINE JSBool
JSID_IS_STRING(jsid id)
{
    return (JSID_BITS(id) & JSID_TYPE_MASK) == 0;
}

static JS_ALWAYS_INLINE JSString *
JSID_TO_STRING(jsid id)
{
    JS_ASSERT(JSID_IS_STRING(id));
    return (JSString *)JSID_BITS(id);
}

static JS_ALWAYS_INLINE JSBool
JSID_IS_ZERO(jsid id)
{
    return JSID_BITS(id) == 0;
}

JS_PUBLIC_API(JSBool)
JS_StringHasBeenInterned(JSContext *cx, JSString *str);

/*
 * Only JSStrings that have been interned via the JSAPI can be turned into
 * jsids by API clients.
 *
 * N.B. if a jsid is backed by a string which has not been interned, that
 * string must be appropriately rooted to avoid being collected by the GC.
 */
JS_PUBLIC_API(jsid)
INTERNED_STRING_TO_JSID(JSContext *cx, JSString *str);

static JS_ALWAYS_INLINE JSBool
JSID_IS_INT(jsid id)
{
    return !!(JSID_BITS(id) & JSID_TYPE_INT);
}

static JS_ALWAYS_INLINE int32_t
JSID_TO_INT(jsid id)
{
    JS_ASSERT(JSID_IS_INT(id));
    return ((uint32_t)JSID_BITS(id)) >> 1;
}

#define JSID_INT_MIN  0
#define JSID_INT_MAX  INT32_MAX

static JS_ALWAYS_INLINE JSBool
INT_FITS_IN_JSID(int32_t i)
{
    return i >= 0;
}

static JS_ALWAYS_INLINE jsid
INT_TO_JSID(int32_t i)
{
    jsid id;
    JS_ASSERT(INT_FITS_IN_JSID(i));
    JSID_BITS(id) = ((i << 1) | JSID_TYPE_INT);
    return id;
}

static JS_ALWAYS_INLINE JSBool
JSID_IS_OBJECT(jsid id)
{
    return (JSID_BITS(id) & JSID_TYPE_MASK) == JSID_TYPE_OBJECT &&
           (size_t)JSID_BITS(id) != JSID_TYPE_OBJECT;
}

static JS_ALWAYS_INLINE JSObject *
JSID_TO_OBJECT(jsid id)
{
    JS_ASSERT(JSID_IS_OBJECT(id));
    return (JSObject *)(JSID_BITS(id) & ~(size_t)JSID_TYPE_MASK);
}

static JS_ALWAYS_INLINE jsid
OBJECT_TO_JSID(JSObject *obj)
{
    jsid id;
    JS_ASSERT(obj != NULL);
    JS_ASSERT(((size_t)obj & JSID_TYPE_MASK) == 0);
    JSID_BITS(id) = ((size_t)obj | JSID_TYPE_OBJECT);
    return id;
}

static JS_ALWAYS_INLINE JSBool
JSID_IS_GCTHING(jsid id)
{
    return JSID_IS_STRING(id) || JSID_IS_OBJECT(id);
}

static JS_ALWAYS_INLINE void *
JSID_TO_GCTHING(jsid id)
{
    return (void *)(JSID_BITS(id) & ~(size_t)JSID_TYPE_MASK);
}

/*
 * A void jsid is not a valid id and only arises as an exceptional API return
 * value, such as in JS_NextProperty. Embeddings must not pass JSID_VOID into
 * JSAPI entry points expecting a jsid and do not need to handle JSID_VOID in
 * hooks receiving a jsid except when explicitly noted in the API contract.
 */

static JS_ALWAYS_INLINE JSBool
JSID_IS_VOID(const jsid id)
{
    JS_ASSERT_IF(((size_t)JSID_BITS(id) & JSID_TYPE_MASK) == JSID_TYPE_VOID,
                 JSID_BITS(id) == JSID_TYPE_VOID);
    return ((size_t)JSID_BITS(id) == JSID_TYPE_VOID);
}

static JS_ALWAYS_INLINE JSBool
JSID_IS_EMPTY(const jsid id)
{
    return ((size_t)JSID_BITS(id) == JSID_TYPE_OBJECT);
}

#undef id

#ifdef JS_USE_JSID_STRUCT_TYPES
extern JS_PUBLIC_DATA(const jsid) JSID_VOID;
extern JS_PUBLIC_DATA(const jsid) JSID_EMPTY;
#else
# define JSID_VOID ((jsid)JSID_TYPE_VOID)
# define JSID_EMPTY ((jsid)JSID_TYPE_OBJECT)
#endif

/*
 * Returns true iff the given jsval is immune to GC and can be used across
 * multiple JSRuntimes without requiring any conversion API.
 */
static JS_ALWAYS_INLINE JSBool
JSVAL_IS_UNIVERSAL(jsval v)
{
    return !JSVAL_IS_GCTHING(v);
}

namespace JS {

class AutoIdRooter : private AutoGCRooter
{
  public:
    explicit AutoIdRooter(JSContext *cx, jsid aId = INT_TO_JSID(0)
                          MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, ID), id_(aId)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    jsid id() {
        return id_;
    }

    jsid * addr() {
        return &id_;
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

  private:
    jsid id_;
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

} /* namespace JS */

/************************************************************************/

/* Property attributes, set in JSPropertySpec and passed to API functions. */
#define JSPROP_ENUMERATE        0x01    /* property is visible to for/in loop */
#define JSPROP_READONLY         0x02    /* not settable: assignment is no-op.
                                           This flag is only valid when neither
                                           JSPROP_GETTER nor JSPROP_SETTER is
                                           set. */
#define JSPROP_PERMANENT        0x04    /* property cannot be deleted */
#define JSPROP_NATIVE_ACCESSORS 0x08    /* set in JSPropertyDescriptor.flags
                                           if getters/setters are JSNatives */
#define JSPROP_GETTER           0x10    /* property holds getter function */
#define JSPROP_SETTER           0x20    /* property holds setter function */
#define JSPROP_SHARED           0x40    /* don't allocate a value slot for this
                                           property; don't copy the property on
                                           set of the same-named property in an
                                           object that delegates to a prototype
                                           containing this property */
#define JSPROP_INDEX            0x80    /* name is actually (int) index */
#define JSPROP_SHORTID         0x100    /* set in JS_DefineProperty attrs
                                           if getters/setters use a shortid */

#define JSFUN_STUB_GSOPS       0x200    /* use JS_PropertyStub getter/setter
                                           instead of defaulting to class gsops
                                           for property holding function */

#define JSFUN_CONSTRUCTOR      0x400    /* native that can be called as a ctor */


/*
 * Specify a generic native prototype methods, i.e., methods of a class
 * prototype that are exposed as static methods taking an extra leading
 * argument: the generic |this| parameter.
 *
 * If you set this flag in a JSFunctionSpec struct's flags initializer, then
 * that struct must live at least as long as the native static method object
 * created due to this flag by JS_DefineFunctions or JS_InitClass.  Typically
 * JSFunctionSpec structs are allocated in static arrays.
 */
#define JSFUN_GENERIC_NATIVE   0x800

#define JSFUN_FLAGS_MASK       0xe00    /* | of all the JSFUN_* flags */

/*
 * The first call to JS_CallOnce by any thread in a process will call 'func'.
 * Later calls to JS_CallOnce with the same JSCallOnceType object will be
 * suppressed.
 *
 * Equivalently: each distinct JSCallOnceType object will allow one JS_CallOnce
 * to invoke its JSInitCallback.
 */
extern JS_PUBLIC_API(JSBool)
JS_CallOnce(JSCallOnceType *once, JSInitCallback func);

/* Microseconds since the epoch, midnight, January 1, 1970 UTC. */
extern JS_PUBLIC_API(int64_t)
JS_Now(void);

/* Don't want to export data, so provide accessors for non-inline jsvals. */
extern JS_PUBLIC_API(jsval)
JS_GetNaNValue(JSContext *cx);

extern JS_PUBLIC_API(jsval)
JS_GetNegativeInfinityValue(JSContext *cx);

extern JS_PUBLIC_API(jsval)
JS_GetPositiveInfinityValue(JSContext *cx);

extern JS_PUBLIC_API(jsval)
JS_GetEmptyStringValue(JSContext *cx);

extern JS_PUBLIC_API(JSString *)
JS_GetEmptyString(JSRuntime *rt);

/*
 * Format is a string of the following characters (spaces are insignificant),
 * specifying the tabulated type conversions:
 *
 *   b      JSBool          Boolean
 *   c      uint16_t/jschar ECMA uint16_t, Unicode char
 *   i      int32_t         ECMA int32_t
 *   u      uint32_t        ECMA uint32_t
 *   j      int32_t         Rounded int32_t (coordinate)
 *   d      double          IEEE double
 *   I      double          Integral IEEE double
 *   S      JSString *      Unicode string, accessed by a JSString pointer
 *   W      jschar *        Unicode character vector, 0-terminated (W for wide)
 *   o      JSObject *      Object reference
 *   f      JSFunction *    Function private
 *   v      jsval           Argument value (no conversion)
 *   *      N/A             Skip this argument (no vararg)
 *   /      N/A             End of required arguments
 *
 * The variable argument list after format must consist of &b, &c, &s, e.g.,
 * where those variables have the types given above.  For the pointer types
 * char *, JSString *, and JSObject *, the pointed-at memory returned belongs
 * to the JS runtime, not to the calling native code.  The runtime promises
 * to keep this memory valid so long as argv refers to allocated stack space
 * (so long as the native function is active).
 *
 * Fewer arguments than format specifies may be passed only if there is a /
 * in format after the last required argument specifier and argc is at least
 * the number of required arguments.  More arguments than format specifies
 * may be passed without error; it is up to the caller to deal with trailing
 * unconverted arguments.
 */
extern JS_PUBLIC_API(JSBool)
JS_ConvertArguments(JSContext *cx, unsigned argc, jsval *argv, const char *format,
                    ...);

#ifdef va_start
extern JS_PUBLIC_API(JSBool)
JS_ConvertArgumentsVA(JSContext *cx, unsigned argc, jsval *argv,
                      const char *format, va_list ap);
#endif

extern JS_PUBLIC_API(JSBool)
JS_ConvertValue(JSContext *cx, jsval v, JSType type, jsval *vp);

extern JS_PUBLIC_API(JSBool)
JS_ValueToObject(JSContext *cx, jsval v, JSObject **objp);

extern JS_PUBLIC_API(JSFunction *)
JS_ValueToFunction(JSContext *cx, jsval v);

extern JS_PUBLIC_API(JSFunction *)
JS_ValueToConstructor(JSContext *cx, jsval v);

extern JS_PUBLIC_API(JSString *)
JS_ValueToString(JSContext *cx, jsval v);

extern JS_PUBLIC_API(JSString *)
JS_ValueToSource(JSContext *cx, jsval v);

extern JS_PUBLIC_API(JSBool)
JS_ValueToNumber(JSContext *cx, jsval v, double *dp);

namespace js {
/*
 * DO NOT CALL THIS.  Use JS::ToNumber
 */
extern JS_PUBLIC_API(bool)
ToNumberSlow(JSContext *cx, JS::Value v, double *dp);

/*
 * DO NOT CALL THIS. Use JS::ToBoolean
 */
extern JS_PUBLIC_API(bool)
ToBooleanSlow(const JS::Value &v);
} /* namespace js */

namespace JS {

/* ES5 9.3 ToNumber. */
JS_ALWAYS_INLINE bool
ToNumber(JSContext *cx, const Value &v, double *out)
{
    AssertArgumentsAreSane(cx, v);
    {
        js::SkipRoot root(cx, &v);
        js::MaybeCheckStackRoots(cx);
    }

    if (v.isNumber()) {
        *out = v.toNumber();
        return true;
    }
    return js::ToNumberSlow(cx, v, out);
}

JS_ALWAYS_INLINE bool
ToBoolean(const Value &v)
{
    if (v.isBoolean())
        return v.toBoolean();
    if (v.isInt32())
        return v.toInt32() != 0;
    if (v.isNullOrUndefined())
        return false;
    if (v.isDouble()) {
        double d = v.toDouble();
        return !mozilla::IsNaN(d) && d != 0;
    }

    /* The slow path handles strings and objects. */
    return js::ToBooleanSlow(v);
}

} /* namespace JS */

extern JS_PUBLIC_API(JSBool)
JS_DoubleIsInt32(double d, int32_t *ip);

extern JS_PUBLIC_API(int32_t)
JS_DoubleToInt32(double d);

extern JS_PUBLIC_API(uint32_t)
JS_DoubleToUint32(double d);

/*
 * Convert a value to a number, then to an int32_t, according to the ECMA rules
 * for ToInt32.
 */
extern JS_PUBLIC_API(JSBool)
JS_ValueToECMAInt32(JSContext *cx, jsval v, int32_t *ip);

/*
 * Convert a value to a number, then to an int64_t, according to the WebIDL
 * rules for ToInt64: http://dev.w3.org/2006/webapi/WebIDL/#es-long-long
 */
extern JS_PUBLIC_API(JSBool)
JS_ValueToInt64(JSContext *cx, jsval v, int64_t *ip);

/*
 * Convert a value to a number, then to an uint64_t, according to the WebIDL
 * rules for ToUint64: http://dev.w3.org/2006/webapi/WebIDL/#es-unsigned-long-long
 */
extern JS_PUBLIC_API(JSBool)
JS_ValueToUint64(JSContext *cx, jsval v, uint64_t *ip);

namespace js {
/* DO NOT CALL THIS.  Use JS::ToInt16. */
extern JS_PUBLIC_API(bool)
ToUint16Slow(JSContext *cx, const JS::Value &v, uint16_t *out);

/* DO NOT CALL THIS.  Use JS::ToInt32. */
extern JS_PUBLIC_API(bool)
ToInt32Slow(JSContext *cx, const JS::Value &v, int32_t *out);

/* DO NOT CALL THIS.  Use JS::ToUint32. */
extern JS_PUBLIC_API(bool)
ToUint32Slow(JSContext *cx, const JS::Value &v, uint32_t *out);

/* DO NOT CALL THIS. Use JS::ToInt64. */
extern JS_PUBLIC_API(bool)
ToInt64Slow(JSContext *cx, const JS::Value &v, int64_t *out);

/* DO NOT CALL THIS. Use JS::ToUint64. */
extern JS_PUBLIC_API(bool)
ToUint64Slow(JSContext *cx, const JS::Value &v, uint64_t *out);
} /* namespace js */

namespace JS {

JS_ALWAYS_INLINE bool
ToUint16(JSContext *cx, const JS::Value &v, uint16_t *out)
{
    AssertArgumentsAreSane(cx, v);
    {
        js::SkipRoot skip(cx, &v);
        js::MaybeCheckStackRoots(cx);
    }

    if (v.isInt32()) {
        *out = uint16_t(v.toInt32());
        return true;
    }
    return js::ToUint16Slow(cx, v, out);
}

JS_ALWAYS_INLINE bool
ToInt32(JSContext *cx, const JS::Value &v, int32_t *out)
{
    AssertArgumentsAreSane(cx, v);
    {
        js::SkipRoot root(cx, &v);
        js::MaybeCheckStackRoots(cx);
    }

    if (v.isInt32()) {
        *out = v.toInt32();
        return true;
    }
    return js::ToInt32Slow(cx, v, out);
}

JS_ALWAYS_INLINE bool
ToUint32(JSContext *cx, const JS::Value &v, uint32_t *out)
{
    AssertArgumentsAreSane(cx, v);
    {
        js::SkipRoot root(cx, &v);
        js::MaybeCheckStackRoots(cx);
    }

    if (v.isInt32()) {
        *out = uint32_t(v.toInt32());
        return true;
    }
    return js::ToUint32Slow(cx, v, out);
}

JS_ALWAYS_INLINE bool
ToInt64(JSContext *cx, const JS::Value &v, int64_t *out)
{
    AssertArgumentsAreSane(cx, v);
    {
        js::SkipRoot skip(cx, &v);
        js::MaybeCheckStackRoots(cx);
    }

    if (v.isInt32()) {
        *out = int64_t(v.toInt32());
        return true;
    }

    return js::ToInt64Slow(cx, v, out);
}

JS_ALWAYS_INLINE bool
ToUint64(JSContext *cx, const JS::Value &v, uint64_t *out)
{
    AssertArgumentsAreSane(cx, v);
    {
        js::SkipRoot skip(cx, &v);
        js::MaybeCheckStackRoots(cx);
    }

    if (v.isInt32()) {
        /* Account for sign extension of negatives into the longer 64bit space. */
        *out = uint64_t(int64_t(v.toInt32()));
        return true;
    }

    return js::ToUint64Slow(cx, v, out);
}


} /* namespace JS */

/*
 * Convert a value to a number, then to a uint32_t, according to the ECMA rules
 * for ToUint32.
 */
extern JS_PUBLIC_API(JSBool)
JS_ValueToECMAUint32(JSContext *cx, jsval v, uint32_t *ip);

/*
 * Convert a value to a number, then to an int32_t if it fits by rounding to
 * nearest; but failing with an error report if the double is out of range
 * or unordered.
 */
extern JS_PUBLIC_API(JSBool)
JS_ValueToInt32(JSContext *cx, jsval v, int32_t *ip);

/*
 * ECMA ToUint16, for mapping a jsval to a Unicode point.
 */
extern JS_PUBLIC_API(JSBool)
JS_ValueToUint16(JSContext *cx, jsval v, uint16_t *ip);

extern JS_PUBLIC_API(JSBool)
JS_ValueToBoolean(JSContext *cx, jsval v, JSBool *bp);

extern JS_PUBLIC_API(JSType)
JS_TypeOfValue(JSContext *cx, jsval v);

extern JS_PUBLIC_API(const char *)
JS_GetTypeName(JSContext *cx, JSType type);

extern JS_PUBLIC_API(JSBool)
JS_StrictlyEqual(JSContext *cx, jsval v1, jsval v2, JSBool *equal);

extern JS_PUBLIC_API(JSBool)
JS_LooselyEqual(JSContext *cx, jsval v1, jsval v2, JSBool *equal);

extern JS_PUBLIC_API(JSBool)
JS_SameValue(JSContext *cx, jsval v1, jsval v2, JSBool *same);

/* True iff fun is the global eval function. */
extern JS_PUBLIC_API(JSBool)
JS_IsBuiltinEvalFunction(JSFunction *fun);

/* True iff fun is the Function constructor. */
extern JS_PUBLIC_API(JSBool)
JS_IsBuiltinFunctionConstructor(JSFunction *fun);

/************************************************************************/

/*
 * Initialization, locking, contexts, and memory allocation.
 *
 * It is important that the first runtime and first context be created in a
 * single-threaded fashion, otherwise the behavior of the library is undefined.
 * See: http://developer.mozilla.org/en/docs/Category:JSAPI_Reference
 */

typedef enum JSUseHelperThreads
{
    JS_NO_HELPER_THREADS,
    JS_USE_HELPER_THREADS
} JSUseHelperThreads;

extern JS_PUBLIC_API(JSRuntime *)
JS_NewRuntime(uint32_t maxbytes, JSUseHelperThreads useHelperThreads);

extern JS_PUBLIC_API(void)
JS_DestroyRuntime(JSRuntime *rt);

extern JS_PUBLIC_API(void)
JS_ShutDown(void);

JS_PUBLIC_API(void *)
JS_GetRuntimePrivate(JSRuntime *rt);

extern JS_PUBLIC_API(JSRuntime *)
JS_GetRuntime(JSContext *cx);

JS_PUBLIC_API(void)
JS_SetRuntimePrivate(JSRuntime *rt, void *data);

extern JS_PUBLIC_API(void)
JS_BeginRequest(JSContext *cx);

extern JS_PUBLIC_API(void)
JS_EndRequest(JSContext *cx);

extern JS_PUBLIC_API(JSBool)
JS_IsInRequest(JSRuntime *rt);

namespace JS {

inline bool
IsPoisonedId(jsid iden)
{
    if (JSID_IS_STRING(iden))
        return JS::IsPoisonedPtr(JSID_TO_STRING(iden));
    if (JSID_IS_OBJECT(iden))
        return JS::IsPoisonedPtr(JSID_TO_OBJECT(iden));
    return false;
}

} /* namespace JS */

namespace js {

template <> struct GCMethods<jsid>
{
    static jsid initial() { return JSID_VOID; }
    static ThingRootKind kind() { return THING_ROOT_ID; }
    static bool poisoned(jsid id) { return JS::IsPoisonedId(id); }
    static bool needsPostBarrier(jsid id) { return false; }
#ifdef JSGC_GENERATIONAL
    static void postBarrier(jsid *idp) {}
    static void relocate(jsid *idp) {}
#endif
};

} /* namespace js */

class JSAutoRequest
{
  public:
    JSAutoRequest(JSContext *cx
                  MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : mContext(cx)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
        JS_BeginRequest(mContext);
    }
    ~JSAutoRequest() {
        JS_EndRequest(mContext);
    }

  protected:
    JSContext *mContext;
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

#if 0
  private:
    static void *operator new(size_t) CPP_THROW_NEW { return 0; };
    static void operator delete(void *, size_t) { };
#endif
};

class JSAutoCheckRequest
{
  public:
    JSAutoCheckRequest(JSContext *cx
                       MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
    {
#if defined JS_THREADSAFE && defined JS_DEBUG
        mContext = cx;
        JS_ASSERT(JS_IsInRequest(JS_GetRuntime(cx)));
#endif
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }

    ~JSAutoCheckRequest() {
#if defined JS_THREADSAFE && defined JS_DEBUG
        JS_ASSERT(JS_IsInRequest(JS_GetRuntime(mContext)));
#endif
    }


  private:
#if defined JS_THREADSAFE && defined JS_DEBUG
    JSContext *mContext;
#endif
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};

extern JS_PUBLIC_API(JSContextCallback)
JS_SetContextCallback(JSRuntime *rt, JSContextCallback cxCallback);

extern JS_PUBLIC_API(JSContext *)
JS_NewContext(JSRuntime *rt, size_t stackChunkSize);

extern JS_PUBLIC_API(void)
JS_DestroyContext(JSContext *cx);

extern JS_PUBLIC_API(void)
JS_DestroyContextNoGC(JSContext *cx);

extern JS_PUBLIC_API(void *)
JS_GetContextPrivate(JSContext *cx);

extern JS_PUBLIC_API(void)
JS_SetContextPrivate(JSContext *cx, void *data);

extern JS_PUBLIC_API(void *)
JS_GetSecondContextPrivate(JSContext *cx);

extern JS_PUBLIC_API(void)
JS_SetSecondContextPrivate(JSContext *cx, void *data);

extern JS_PUBLIC_API(JSRuntime *)
JS_GetRuntime(JSContext *cx);

extern JS_PUBLIC_API(JSContext *)
JS_ContextIterator(JSRuntime *rt, JSContext **iterp);

extern JS_PUBLIC_API(JSVersion)
JS_GetVersion(JSContext *cx);

// Mutate the version on the compartment. This is generally discouraged, but
// necessary to support the version mutation in the js and xpc shell command
// set.
//
// It would be nice to put this in jsfriendapi, but the linkage requirements
// of the shells make that impossible.
JS_PUBLIC_API(void)
JS_SetVersionForCompartment(JSCompartment *compartment, JSVersion version);

extern JS_PUBLIC_API(const char *)
JS_VersionToString(JSVersion version);

extern JS_PUBLIC_API(JSVersion)
JS_StringToVersion(const char *string);

/*
 * JS options are orthogonal to version, and may be freely composed with one
 * another as well as with version.
 *
 * JSOPTION_VAROBJFIX is recommended -- see the comments associated with the
 * prototypes for JS_ExecuteScript, JS_EvaluateScript, etc.
 */
#define JSOPTION_EXTRA_WARNINGS JS_BIT(0)       /* warn on dubious practices */
#define JSOPTION_WERROR         JS_BIT(1)       /* convert warning to error */
#define JSOPTION_VAROBJFIX      JS_BIT(2)       /* make JS_EvaluateScript use
                                                   the last object on its 'obj'
                                                   param's scope chain as the
                                                   ECMA 'variables object' */
#define JSOPTION_PRIVATE_IS_NSISUPPORTS \
                                JS_BIT(3)       /* context private data points
                                                   to an nsISupports subclass */
#define JSOPTION_COMPILE_N_GO   JS_BIT(4)       /* caller of JS_Compile*Script
                                                   promises to execute compiled
                                                   script once only; enables
                                                   compile-time scope chain
                                                   resolution of consts. */

/* JS_BIT(5) is currently unused. */

/* JS_BIT(6) is currently unused. */

/* JS_BIT(7) is currently unused. */

#define JSOPTION_DONT_REPORT_UNCAUGHT                                   \
                                JS_BIT(8)       /* When returning from the
                                                   outermost API call, prevent
                                                   uncaught exceptions from
                                                   being converted to error
                                                   reports */

/* JS_BIT(9) is currently unused. */

/* JS_BIT(10) is currently unused. */

/* JS_BIT(11) is currently unused. */

#define JSOPTION_NO_SCRIPT_RVAL JS_BIT(12)      /* A promise to the compiler
                                                   that a null rval out-param
                                                   will be passed to each call
                                                   to JS_ExecuteScript. */
#define JSOPTION_UNROOTED_GLOBAL JS_BIT(13)     /* The GC will not root the
                                                   contexts' default compartment
                                                   object, leaving that up to the
                                                   embedding. */

#define JSOPTION_BASELINE       JS_BIT(14)      /* Baseline compiler. */

#define JSOPTION_PCCOUNT        JS_BIT(15)      /* Collect per-op execution counts */

#define JSOPTION_TYPE_INFERENCE JS_BIT(16)      /* Perform type inference. */
#define JSOPTION_STRICT_MODE    JS_BIT(17)      /* Provides a way to force
                                                   strict mode for all code
                                                   without requiring
                                                   "use strict" annotations. */

#define JSOPTION_ION            JS_BIT(18)      /* IonMonkey */

#define JSOPTION_ASMJS          JS_BIT(19)      /* optimizingasm.js compiler */

#define JSOPTION_MASK           JS_BITMASK(20)

extern JS_PUBLIC_API(uint32_t)
JS_GetOptions(JSContext *cx);

extern JS_PUBLIC_API(uint32_t)
JS_SetOptions(JSContext *cx, uint32_t options);

extern JS_PUBLIC_API(uint32_t)
JS_ToggleOptions(JSContext *cx, uint32_t options);

extern JS_PUBLIC_API(void)
JS_SetJitHardening(JSRuntime *rt, JSBool enabled);

extern JS_PUBLIC_API(const char *)
JS_GetImplementationVersion(void);

extern JS_PUBLIC_API(void)
JS_SetDestroyCompartmentCallback(JSRuntime *rt, JSDestroyCompartmentCallback callback);

extern JS_PUBLIC_API(void)
JS_SetDestroyZoneCallback(JSRuntime *rt, JSZoneCallback callback);

extern JS_PUBLIC_API(void)
JS_SetSweepZoneCallback(JSRuntime *rt, JSZoneCallback callback);

extern JS_PUBLIC_API(void)
JS_SetCompartmentNameCallback(JSRuntime *rt, JSCompartmentNameCallback callback);

extern JS_PUBLIC_API(JSWrapObjectCallback)
JS_SetWrapObjectCallbacks(JSRuntime *rt,
                          JSWrapObjectCallback callback,
                          JSSameCompartmentWrapObjectCallback sccallback,
                          JSPreWrapCallback precallback);

extern JS_PUBLIC_API(void)
JS_SetCompartmentPrivate(JSCompartment *compartment, void *data);

extern JS_PUBLIC_API(void *)
JS_GetCompartmentPrivate(JSCompartment *compartment);

extern JS_PUBLIC_API(void)
JS_SetZoneUserData(JS::Zone *zone, void *data);

extern JS_PUBLIC_API(void *)
JS_GetZoneUserData(JS::Zone *zone);

extern JS_PUBLIC_API(JSBool)
JS_WrapObject(JSContext *cx, JSObject **objp);

extern JS_PUBLIC_API(JSBool)
JS_WrapValue(JSContext *cx, jsval *vp);

extern JS_PUBLIC_API(JSBool)
JS_WrapId(JSContext *cx, jsid *idp);

extern JS_PUBLIC_API(JSObject *)
JS_TransplantObject(JSContext *cx, JS::HandleObject origobj, JS::HandleObject target);

extern JS_PUBLIC_API(JSBool)
JS_RefreshCrossCompartmentWrappers(JSContext *cx, JSObject *ob);

/*
 * At any time, a JSContext has a current (possibly-NULL) compartment.
 * Compartments are described in:
 *
 *   developer.mozilla.org/en-US/docs/SpiderMonkey/SpiderMonkey_compartments
 *
 * The current compartment of a context may be changed. The preferred way to do
 * this is with JSAutoCompartment:
 *
 *   void foo(JSContext *cx, JSObject *obj) {
 *     // in some compartment 'c'
 *     {
 *       JSAutoCompartment ac(cx, obj);  // constructor enters
 *       // in the compartment of 'obj'
 *     }                                 // destructor leaves
 *     // back in compartment 'c'
 *   }
 *
 * For more complicated uses that don't neatly fit in a C++ stack frame, the
 * compartment can entered and left using separate function calls:
 *
 *   void foo(JSContext *cx, JSObject *obj) {
 *     // in 'oldCompartment'
 *     JSCompartment *oldCompartment = JS_EnterCompartment(cx, obj);
 *     // in the compartment of 'obj'
 *     JS_LeaveCompartment(cx, oldCompartment);
 *     // back in 'oldCompartment'
 *   }
 *
 * Note: these calls must still execute in a LIFO manner w.r.t all other
 * enter/leave calls on the context. Furthermore, only the return value of a
 * JS_EnterCompartment call may be passed as the 'oldCompartment' argument of
 * the corresponding JS_LeaveCompartment call.
 */

class JS_PUBLIC_API(JSAutoCompartment)
{
    JSContext *cx_;
    JSCompartment *oldCompartment_;
  public:
    JSAutoCompartment(JSContext *cx, JSObject *target);
    JSAutoCompartment(JSContext *cx, JSScript *target);
    ~JSAutoCompartment();
};

/* NB: This API is infallible; a NULL return value does not indicate error. */
extern JS_PUBLIC_API(JSCompartment *)
JS_EnterCompartment(JSContext *cx, JSObject *target);

extern JS_PUBLIC_API(void)
JS_LeaveCompartment(JSContext *cx, JSCompartment *oldCompartment);

typedef void (*JSIterateCompartmentCallback)(JSRuntime *rt, void *data, JSCompartment *compartment);

/*
 * This function calls |compartmentCallback| on every compartment.  Beware that
 * there is no guarantee that the compartment will survive after the callback
 * returns.
 */
extern JS_PUBLIC_API(void)
JS_IterateCompartments(JSRuntime *rt, void *data,
                       JSIterateCompartmentCallback compartmentCallback);

extern JS_PUBLIC_API(void)
JS_SetGlobalObject(JSContext *cx, JSObject *obj);

/*
 * Initialize standard JS class constructors, prototypes, and any top-level
 * functions and constants associated with the standard classes (e.g. isNaN
 * for Number).
 *
 * NB: This sets cx's global object to obj if it was null.
 */
extern JS_PUBLIC_API(JSBool)
JS_InitStandardClasses(JSContext *cx, JSObject *obj);

/*
 * Resolve id, which must contain either a string or an int, to a standard
 * class name in obj if possible, defining the class's constructor and/or
 * prototype and storing true in *resolved.  If id does not name a standard
 * class or a top-level property induced by initializing a standard class,
 * store false in *resolved and just return true.  Return false on error,
 * as usual for JSBool result-typed API entry points.
 *
 * This API can be called directly from a global object class's resolve op,
 * to define standard classes lazily.  The class's enumerate op should call
 * JS_EnumerateStandardClasses(cx, obj), to define eagerly during for..in
 * loops any classes not yet resolved lazily.
 */
extern JS_PUBLIC_API(JSBool)
JS_ResolveStandardClass(JSContext *cx, JS::HandleObject obj, JS::HandleId id,
                        JSBool *resolved);

extern JS_PUBLIC_API(JSBool)
JS_EnumerateStandardClasses(JSContext *cx, JS::HandleObject obj);

extern JS_PUBLIC_API(JSBool)
JS_GetClassObject(JSContext *cx, JSObject *obj, JSProtoKey key, JSObject **objp);

extern JS_PUBLIC_API(JSBool)
JS_GetClassPrototype(JSContext *cx, JSProtoKey key, JSObject **objp);

extern JS_PUBLIC_API(JSProtoKey)
JS_IdentifyClassPrototype(JSContext *cx, JSObject *obj);

/*
 * Returns the original value of |Function.prototype| from the global object in
 * which |forObj| was created.
 */
extern JS_PUBLIC_API(JSObject *)
JS_GetFunctionPrototype(JSContext *cx, JSObject *forObj);

/*
 * Returns the original value of |Object.prototype| from the global object in
 * which |forObj| was created.
 */
extern JS_PUBLIC_API(JSObject *)
JS_GetObjectPrototype(JSContext *cx, JSObject *forObj);

/*
 * Returns the original value of |Array.prototype| from the global object in
 * which |forObj| was created.
 */
extern JS_PUBLIC_API(JSObject *)
JS_GetArrayPrototype(JSContext *cx, JSObject *forObj);

extern JS_PUBLIC_API(JSObject *)
JS_GetGlobalForObject(JSContext *cx, JSObject *obj);

extern JS_PUBLIC_API(JSBool)
JS_IsGlobalObject(JSObject *obj);

/*
 * May return NULL, if |c| never had a global (e.g. the atoms compartment), or
 * if |c|'s global has been collected.
 */
extern JS_PUBLIC_API(JSObject *)
JS_GetGlobalForCompartmentOrNull(JSContext *cx, JSCompartment *c);

extern JS_PUBLIC_API(JSObject *)
JS_GetGlobalForScopeChain(JSContext *cx);

/*
 * This method returns the global corresponding to the most recent scripted
 * frame, which may not match the cx's current compartment. This is extremely
 * dangerous, because it can bypass compartment security invariants in subtle
 * ways. To use it safely, the caller must perform a subsequent security
 * check. There is currently only one consumer of this function in Gecko, and
 * it should probably stay that way. If you'd like to use it, please consult
 * the XPConnect module owner first.
 */
extern JS_PUBLIC_API(JSObject *)
JS_GetScriptedGlobal(JSContext *cx);

/*
 * Initialize the 'Reflect' object on a global object.
 */
extern JS_PUBLIC_API(JSObject *)
JS_InitReflect(JSContext *cx, JSObject *global);

#ifdef JS_HAS_CTYPES
/*
 * Initialize the 'ctypes' object on a global variable 'obj'. The 'ctypes'
 * object will be sealed.
 */
extern JS_PUBLIC_API(JSBool)
JS_InitCTypesClass(JSContext *cx, JSObject *global);

/*
 * Convert a unicode string 'source' of length 'slen' to the platform native
 * charset, returning a null-terminated string allocated with JS_malloc. On
 * failure, this function should report an error.
 */
typedef char *
(* JSCTypesUnicodeToNativeFun)(JSContext *cx, const jschar *source, size_t slen);

/*
 * Set of function pointers that ctypes can use for various internal functions.
 * See JS_SetCTypesCallbacks below. Providing NULL for a function is safe,
 * and will result in the applicable ctypes functionality not being available.
 */
struct JSCTypesCallbacks {
    JSCTypesUnicodeToNativeFun unicodeToNative;
};

typedef struct JSCTypesCallbacks JSCTypesCallbacks;

/*
 * Set the callbacks on the provided 'ctypesObj' object. 'callbacks' should be a
 * pointer to static data that exists for the lifetime of 'ctypesObj', but it
 * may safely be altered after calling this function and without having
 * to call this function again.
 */
extern JS_PUBLIC_API(void)
JS_SetCTypesCallbacks(JSObject *ctypesObj, JSCTypesCallbacks *callbacks);
#endif

typedef JSBool
(* JSEnumerateDiagnosticMemoryCallback)(void *ptr, size_t length);

/*
 * Enumerate memory regions that contain diagnostic information
 * intended to be included in crash report minidumps.
 */
extern JS_PUBLIC_API(void)
JS_EnumerateDiagnosticMemoryRegions(JSEnumerateDiagnosticMemoryCallback callback);

extern JS_PUBLIC_API(void *)
JS_malloc(JSContext *cx, size_t nbytes);

extern JS_PUBLIC_API(void *)
JS_realloc(JSContext *cx, void *p, size_t nbytes);

/*
 * A wrapper for js_free(p) that may delay js_free(p) invocation as a
 * performance optimization.
 * cx may be NULL.
 */
extern JS_PUBLIC_API(void)
JS_free(JSContext *cx, void *p);

/*
 * A wrapper for js_free(p) that may delay js_free(p) invocation as a
 * performance optimization as specified by the given JSFreeOp instance.
 */
extern JS_PUBLIC_API(void)
JS_freeop(JSFreeOp *fop, void *p);

extern JS_PUBLIC_API(JSFreeOp *)
JS_GetDefaultFreeOp(JSRuntime *rt);

extern JS_PUBLIC_API(void)
JS_updateMallocCounter(JSContext *cx, size_t nbytes);

extern JS_PUBLIC_API(char *)
JS_strdup(JSContext *cx, const char *s);

/* Duplicate a string.  Does not report an error on failure. */
extern JS_PUBLIC_API(char *)
JS_strdup(JSRuntime *rt, const char *s);


/*
 * A GC root is a pointer to a jsval, JSObject * or JSString * that itself
 * points into the GC heap. JS_AddValueRoot takes a pointer to a jsval and
 * JS_AddGCThingRoot takes a pointer to a JSObject * or JString *.
 *
 * Note that, since JS_Add*Root stores the address of a variable (of type
 * jsval, JSString *, or JSObject *), that variable must live until
 * JS_Remove*Root is called to remove that variable. For example, after:
 *
 *   void some_function() {
 *     jsval v;
 *     JS_AddNamedValueRoot(cx, &v, "name");
 *
 * the caller must perform
 *
 *     JS_RemoveValueRoot(cx, &v);
 *
 * before some_function() returns.
 *
 * Also, use JS_AddNamed*Root(cx, &structPtr->memberObj, "structPtr->memberObj")
 * in preference to JS_Add*Root(cx, &structPtr->memberObj), in order to identify
 * roots by their source callsites.  This way, you can find the callsite while
 * debugging if you should fail to do JS_Remove*Root(cx, &structPtr->memberObj)
 * before freeing structPtr's memory.
 */
extern JS_PUBLIC_API(JSBool)
JS_AddValueRoot(JSContext *cx, jsval *vp);

extern JS_PUBLIC_API(JSBool)
JS_AddStringRoot(JSContext *cx, JSString **rp);

extern JS_PUBLIC_API(JSBool)
JS_AddObjectRoot(JSContext *cx, JSObject **rp);

#ifdef NAME_ALL_GC_ROOTS
#define JS_DEFINE_TO_TOKEN(def) #def
#define JS_DEFINE_TO_STRING(def) JS_DEFINE_TO_TOKEN(def)
#define JS_AddValueRoot(cx,vp) JS_AddNamedValueRoot((cx), (vp), (__FILE__ ":" JS_TOKEN_TO_STRING(__LINE__))
#define JS_AddStringRoot(cx,rp) JS_AddNamedStringRoot((cx), (rp), (__FILE__ ":" JS_TOKEN_TO_STRING(__LINE__))
#define JS_AddObjectRoot(cx,rp) JS_AddNamedObjectRoot((cx), (rp), (__FILE__ ":" JS_TOKEN_TO_STRING(__LINE__))
#endif

extern JS_PUBLIC_API(JSBool)
JS_AddNamedValueRoot(JSContext *cx, jsval *vp, const char *name);

extern JS_PUBLIC_API(JSBool)
JS_AddNamedValueRootRT(JSRuntime *rt, jsval *vp, const char *name);

extern JS_PUBLIC_API(JSBool)
JS_AddNamedStringRoot(JSContext *cx, JSString **rp, const char *name);

extern JS_PUBLIC_API(JSBool)
JS_AddNamedObjectRoot(JSContext *cx, JSObject **rp, const char *name);

extern JS_PUBLIC_API(JSBool)
JS_AddNamedScriptRoot(JSContext *cx, JSScript **rp, const char *name);

extern JS_PUBLIC_API(void)
JS_RemoveValueRoot(JSContext *cx, jsval *vp);

extern JS_PUBLIC_API(void)
JS_RemoveStringRoot(JSContext *cx, JSString **rp);

extern JS_PUBLIC_API(void)
JS_RemoveObjectRoot(JSContext *cx, JSObject **rp);

extern JS_PUBLIC_API(void)
JS_RemoveScriptRoot(JSContext *cx, JSScript **rp);

extern JS_PUBLIC_API(void)
JS_RemoveValueRootRT(JSRuntime *rt, jsval *vp);

extern JS_PUBLIC_API(void)
JS_RemoveStringRootRT(JSRuntime *rt, JSString **rp);

extern JS_PUBLIC_API(void)
JS_RemoveObjectRootRT(JSRuntime *rt, JSObject **rp);

extern JS_PUBLIC_API(void)
JS_RemoveScriptRootRT(JSRuntime *rt, JSScript **rp);

/* TODO: remove these APIs */

extern JS_FRIEND_API(void)
js_RemoveRoot(JSRuntime *rt, void *rp);

/*
 * C-compatible version of the Anchor class. It should be called after the last
 * use of the variable it protects.
 */
extern JS_NEVER_INLINE JS_PUBLIC_API(void)
JS_AnchorPtr(void *p);

/*
 * Register externally maintained GC roots.
 *
 * traceOp: the trace operation. For each root the implementation should call
 *          JS_CallTracer whenever the root contains a traceable thing.
 * data:    the data argument to pass to each invocation of traceOp.
 */
extern JS_PUBLIC_API(JSBool)
JS_AddExtraGCRootsTracer(JSRuntime *rt, JSTraceDataOp traceOp, void *data);

/* Undo a call to JS_AddExtraGCRootsTracer. */
extern JS_PUBLIC_API(void)
JS_RemoveExtraGCRootsTracer(JSRuntime *rt, JSTraceDataOp traceOp, void *data);

/*
 * JS_CallTracer API and related macros for implementors of JSTraceOp, to
 * enumerate all references to traceable things reachable via a property or
 * other strong ref identified for debugging purposes by name or index or
 * a naming callback.
 *
 * See the JSTraceOp typedef.
 */

/*
 * Use the following macros to check if a particular jsval is a traceable
 * thing and to extract the thing and its kind to pass to JS_CallTracer.
 */
static JS_ALWAYS_INLINE JSBool
JSVAL_IS_TRACEABLE(jsval v)
{
    return JSVAL_IS_TRACEABLE_IMPL(JSVAL_TO_IMPL(v));
}

static JS_ALWAYS_INLINE void *
JSVAL_TO_TRACEABLE(jsval v)
{
    return JSVAL_TO_GCTHING(v);
}

static JS_ALWAYS_INLINE JSGCTraceKind
JSVAL_TRACE_KIND(jsval v)
{
    JS_ASSERT(JSVAL_IS_GCTHING(v));
    return (JSGCTraceKind) JSVAL_TRACE_KIND_IMPL(JSVAL_TO_IMPL(v));
}

/*
 * Tracer callback, called for each traceable thing directly referenced by a
 * particular object or runtime structure. It is the callback responsibility
 * to ensure the traversal of the full object graph via calling eventually
 * JS_TraceChildren on the passed thing. In this case the callback must be
 * prepared to deal with cycles in the traversal graph.
 *
 * kind argument is one of JSTRACE_OBJECT, JSTRACE_STRING or a tag denoting
 * internal implementation-specific traversal kind. In the latter case the only
 * operations on thing that the callback can do is to call JS_TraceChildren or
 * JS_GetTraceThingInfo.
 *
 * If eagerlyTraceWeakMaps is true, when we trace a WeakMap visit all
 * of its mappings.  This should be used in cases where the tracer
 * wants to use the existing liveness of entries.
 */
typedef void
(* JSTraceCallback)(JSTracer *trc, void **thingp, JSGCTraceKind kind);

enum WeakMapTraceKind {
    DoNotTraceWeakMaps = 0,
    TraceWeakMapValues = 1,
    TraceWeakMapKeysValues = 2
};

struct JSTracer {
    JSRuntime           *runtime;
    JSTraceCallback     callback;
    JSTraceNamePrinter  debugPrinter;
    const void          *debugPrintArg;
    size_t              debugPrintIndex;
    WeakMapTraceKind    eagerlyTraceWeakMaps;
#ifdef JS_GC_ZEAL
    void                *realLocation;
#endif
};

/*
 * Set debugging information about a reference to a traceable thing to prepare
 * for the following call to JS_CallTracer.
 *
 * When printer is null, arg must be const char * or char * C string naming
 * the reference and index must be either (size_t)-1 indicating that the name
 * alone describes the reference or it must be an index into some array vector
 * that stores the reference.
 *
 * When printer callback is not null, the arg and index arguments are
 * available to the callback as debugPrintArg and debugPrintIndex fields
 * of JSTracer.
 *
 * The storage for name or callback's arguments needs to live only until
 * the following call to JS_CallTracer returns.
 */
# define JS_SET_TRACING_DETAILS(trc, printer, arg, index)                     \
    JS_BEGIN_MACRO                                                            \
        (trc)->debugPrinter = (printer);                                      \
        (trc)->debugPrintArg = (arg);                                         \
        (trc)->debugPrintIndex = (index);                                     \
    JS_END_MACRO

/*
 * Sets the real location for a marked reference, when passing the address
 * directly is not feasable.
 *
 * FIXME: This is currently overcomplicated by our need to nest calls for Values
 * stored as keys in hash tables, but will get simplified once we can rekey
 * in-place.
 */
#ifdef JS_GC_ZEAL
# define JS_SET_TRACING_LOCATION(trc, location)                               \
    JS_BEGIN_MACRO                                                            \
        if (!(trc)->realLocation || !(location))                              \
            (trc)->realLocation = (location);                                 \
    JS_END_MACRO
# define JS_UNSET_TRACING_LOCATION(trc)                                       \
    JS_BEGIN_MACRO                                                            \
        (trc)->realLocation = NULL;                                           \
    JS_END_MACRO
#else
# define JS_SET_TRACING_LOCATION(trc, location)                               \
    JS_BEGIN_MACRO                                                            \
    JS_END_MACRO
# define JS_UNSET_TRACING_LOCATION(trc)                                       \
    JS_BEGIN_MACRO                                                            \
    JS_END_MACRO
#endif


/*
 * Convenience macro to describe the argument of JS_CallTracer using C string
 * and index.
 */
# define JS_SET_TRACING_INDEX(trc, name, index)                               \
    JS_SET_TRACING_DETAILS(trc, NULL, name, index)

/*
 * Convenience macro to describe the argument of JS_CallTracer using C string.
 */
# define JS_SET_TRACING_NAME(trc, name)                                       \
    JS_SET_TRACING_DETAILS(trc, NULL, name, (size_t)-1)

/*
 * The JS_Call*Tracer family of functions traces the given GC thing reference.
 * This performs the tracing action configured on the given JSTracer:
 * typically calling the JSTracer::callback or marking the thing as live.
 *
 * The argument to JS_Call*Tracer is an in-out param: when the function
 * returns, the garbage collector might have moved the GC thing. In this case,
 * the reference passed to JS_Call*Tracer will be updated to the object's new
 * location. Callers of this method are responsible for updating any state
 * that is dependent on the object's address. For example, if the object's
 * address is used as a key in a hashtable, then the object must be removed
 * and re-inserted with the correct hash.
 */
extern JS_PUBLIC_API(void)
JS_CallValueTracer(JSTracer *trc, JS::Value *valuep, const char *name);

extern JS_PUBLIC_API(void)
JS_CallIdTracer(JSTracer *trc, jsid *idp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallObjectTracer(JSTracer *trc, JSObject **objp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallStringTracer(JSTracer *trc, JSString **strp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallScriptTracer(JSTracer *trc, JSScript **scriptp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallHeapValueTracer(JSTracer *trc, JS::Heap<JS::Value> *valuep, const char *name);

extern JS_PUBLIC_API(void)
JS_CallHeapIdTracer(JSTracer *trc, JS::Heap<jsid> *idp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallHeapObjectTracer(JSTracer *trc, JS::Heap<JSObject *> *objp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallHeapStringTracer(JSTracer *trc, JS::Heap<JSString *> *strp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallHeapScriptTracer(JSTracer *trc, JS::Heap<JSScript *> *scriptp, const char *name);

extern JS_PUBLIC_API(void)
JS_CallGenericTracer(JSTracer *trc, void *gcthing, const char *name);

template <typename HashSetEnum>
inline void
JS_CallHashSetObjectTracer(JSTracer *trc, HashSetEnum &e, JSObject *const &key, const char *name)
{
    JSObject *updated = key;
    JS_SET_TRACING_LOCATION(trc, reinterpret_cast<void *>(&const_cast<JSObject *&>(key)));
    JS_CallObjectTracer(trc, &updated, name);
    if (updated != key)
        e.rekeyFront(key, updated);
}

/*
 * The JS_CallMaskedObjectTracer variant traces a JSObject* that is stored
 * with flags embedded in the low bits of the word. The flagMask parameter
 * expects |*objp & flagMask| to yield the flags with the pointer value
 * stripped and |*objp & ~flagMask| to yield a valid GC pointer.
 */
extern JS_PUBLIC_API(void)
JS_CallMaskedObjectTracer(JSTracer *trc, uintptr_t *objp, uintptr_t flagMask, const char *name);

/*
 * API for JSTraceCallback implementations.
 */
extern JS_PUBLIC_API(void)
JS_TracerInit(JSTracer *trc, JSRuntime *rt, JSTraceCallback callback);

extern JS_PUBLIC_API(void)
JS_TraceChildren(JSTracer *trc, void *thing, JSGCTraceKind kind);

extern JS_PUBLIC_API(void)
JS_TraceRuntime(JSTracer *trc);

extern JS_PUBLIC_API(void)
JS_GetTraceThingInfo(char *buf, size_t bufsize, JSTracer *trc,
                     void *thing, JSGCTraceKind kind, JSBool includeDetails);

extern JS_PUBLIC_API(const char *)
JS_GetTraceEdgeName(JSTracer *trc, char *buffer, int bufferSize);

#ifdef JS_DEBUG

/*
 * Debug-only method to dump the object graph of heap-allocated things.
 *
 * fp:              file for the dump output.
 * start:           when non-null, dump only things reachable from start
 *                  thing. Otherwise dump all things reachable from the
 *                  runtime roots.
 * startKind:       trace kind of start if start is not null. Must be
 *                  JSTRACE_OBJECT when start is null.
 * thingToFind:     dump only paths in the object graph leading to thingToFind
 *                  when non-null.
 * maxDepth:        the upper bound on the number of edges to descend from the
 *                  graph roots.
 * thingToIgnore:   thing to ignore during the graph traversal when non-null.
 */
extern JS_PUBLIC_API(JSBool)
JS_DumpHeap(JSRuntime *rt, FILE *fp, void* startThing, JSGCTraceKind kind,
            void *thingToFind, size_t maxDepth, void *thingToIgnore);

#endif

/*
 * Garbage collector API.
 */
extern JS_PUBLIC_API(void)
JS_GC(JSRuntime *rt);

extern JS_PUBLIC_API(void)
JS_MaybeGC(JSContext *cx);

extern JS_PUBLIC_API(void)
JS_SetGCCallback(JSRuntime *rt, JSGCCallback cb);

extern JS_PUBLIC_API(void)
JS_SetFinalizeCallback(JSRuntime *rt, JSFinalizeCallback cb);

extern JS_PUBLIC_API(JSBool)
JS_IsGCMarkingTracer(JSTracer *trc);

/*
 * JS_IsAboutToBeFinalized checks if the given object is going to be finalized
 * at the end of the current GC. When called outside of the context of a GC,
 * this function will return false. Typically this function is used on weak
 * references, where the reference should be nulled out or destroyed if the
 * given object is about to be finalized.
 *
 * The argument to JS_IsAboutToBeFinalized is an in-out param: when the
 * function returns false, the object being referenced is still alive, but the
 * garbage collector might have moved it. In this case, the reference passed
 * to JS_IsAboutToBeFinalized will be updated to the object's new location.
 * Callers of this method are responsible for updating any state that is
 * dependent on the object's address. For example, if the object's address is
 * used as a key in a hashtable, then the object must be removed and
 * re-inserted with the correct hash.
 */
extern JS_PUBLIC_API(JSBool)
JS_IsAboutToBeFinalized(JSObject **obj);

typedef enum JSGCParamKey {
    /* Maximum nominal heap before last ditch GC. */
    JSGC_MAX_BYTES          = 0,

    /* Number of JS_malloc bytes before last ditch GC. */
    JSGC_MAX_MALLOC_BYTES   = 1,

    /* Amount of bytes allocated by the GC. */
    JSGC_BYTES = 3,

    /* Number of times when GC was invoked. */
    JSGC_NUMBER = 4,

    /* Max size of the code cache in bytes. */
    JSGC_MAX_CODE_CACHE_BYTES = 5,

    /* Select GC mode. */
    JSGC_MODE = 6,

    /* Number of cached empty GC chunks. */
    JSGC_UNUSED_CHUNKS = 7,

    /* Total number of allocated GC chunks. */
    JSGC_TOTAL_CHUNKS = 8,

    /* Max milliseconds to spend in an incremental GC slice. */
    JSGC_SLICE_TIME_BUDGET = 9,

    /* Maximum size the GC mark stack can grow to. */
    JSGC_MARK_STACK_LIMIT = 10,

    /*
     * GCs less than this far apart in time will be considered 'high-frequency GCs'.
     * See setGCLastBytes in jsgc.cpp.
     */
    JSGC_HIGH_FREQUENCY_TIME_LIMIT = 11,

    /* Start of dynamic heap growth. */
    JSGC_HIGH_FREQUENCY_LOW_LIMIT = 12,

    /* End of dynamic heap growth. */
    JSGC_HIGH_FREQUENCY_HIGH_LIMIT = 13,

    /* Upper bound of heap growth. */
    JSGC_HIGH_FREQUENCY_HEAP_GROWTH_MAX = 14,

    /* Lower bound of heap growth. */
    JSGC_HIGH_FREQUENCY_HEAP_GROWTH_MIN = 15,

    /* Heap growth for low frequency GCs. */
    JSGC_LOW_FREQUENCY_HEAP_GROWTH = 16,

    /*
     * If false, the heap growth factor is fixed at 3. If true, it is determined
     * based on whether GCs are high- or low- frequency.
     */
    JSGC_DYNAMIC_HEAP_GROWTH = 17,

    /* If true, high-frequency GCs will use a longer mark slice. */
    JSGC_DYNAMIC_MARK_SLICE = 18,

    /* Number of megabytes of analysis data to allocate before purging. */
    JSGC_ANALYSIS_PURGE_TRIGGER = 19,

    /* Lower limit after which we limit the heap growth. */
    JSGC_ALLOCATION_THRESHOLD = 20,

    /*
     * We decommit memory lazily. If more than this number of megabytes is
     * available to be decommitted, then JS_MaybeGC will trigger a shrinking GC
     * to decommit it.
     */
    JSGC_DECOMMIT_THRESHOLD = 21
} JSGCParamKey;

typedef enum JSGCMode {
    /* Perform only global GCs. */
    JSGC_MODE_GLOBAL = 0,

    /* Perform per-compartment GCs until too much garbage has accumulated. */
    JSGC_MODE_COMPARTMENT = 1,

    /*
     * Collect in short time slices rather than all at once. Implies
     * JSGC_MODE_COMPARTMENT.
     */
    JSGC_MODE_INCREMENTAL = 2
} JSGCMode;

extern JS_PUBLIC_API(void)
JS_SetGCParameter(JSRuntime *rt, JSGCParamKey key, uint32_t value);

extern JS_PUBLIC_API(uint32_t)
JS_GetGCParameter(JSRuntime *rt, JSGCParamKey key);

extern JS_PUBLIC_API(void)
JS_SetGCParameterForThread(JSContext *cx, JSGCParamKey key, uint32_t value);

extern JS_PUBLIC_API(uint32_t)
JS_GetGCParameterForThread(JSContext *cx, JSGCParamKey key);

/*
 * Create a new JSString whose chars member refers to external memory, i.e.,
 * memory requiring application-specific finalization.
 */
extern JS_PUBLIC_API(JSString *)
JS_NewExternalString(JSContext *cx, const jschar *chars, size_t length,
                     const JSStringFinalizer *fin);

/*
 * Return whether 'str' was created with JS_NewExternalString or
 * JS_NewExternalStringWithClosure.
 */
extern JS_PUBLIC_API(JSBool)
JS_IsExternalString(JSString *str);

/*
 * Return the 'closure' arg passed to JS_NewExternalStringWithClosure or NULL
 * if the external string was created via JS_NewExternalString.
 */
extern JS_PUBLIC_API(const JSStringFinalizer *)
JS_GetExternalStringFinalizer(JSString *str);

/*
 * Set the size of the native stack that should not be exceed. To disable
 * stack size checking pass 0.
 */
extern JS_PUBLIC_API(void)
JS_SetNativeStackQuota(JSRuntime *cx, size_t stackSize);

/************************************************************************/

/*
 * Classes, objects, and properties.
 */
typedef void (*JSClassInternal)();

struct JSClass {
    const char          *name;
    uint32_t            flags;

    /* Mandatory non-null function pointer members. */
    JSPropertyOp        addProperty;
    JSDeletePropertyOp  delProperty;
    JSPropertyOp        getProperty;
    JSStrictPropertyOp  setProperty;
    JSEnumerateOp       enumerate;
    JSResolveOp         resolve;
    JSConvertOp         convert;
    JSFinalizeOp        finalize;

    /* Optionally non-null members start here. */
    JSCheckAccessOp     checkAccess;
    JSNative            call;
    JSHasInstanceOp     hasInstance;
    JSNative            construct;
    JSTraceOp           trace;

    void                *reserved[40];
};

#define JSCLASS_HAS_PRIVATE             (1<<0)  /* objects have private slot */
#define JSCLASS_NEW_ENUMERATE           (1<<1)  /* has JSNewEnumerateOp hook */
#define JSCLASS_NEW_RESOLVE             (1<<2)  /* has JSNewResolveOp hook */
#define JSCLASS_PRIVATE_IS_NSISUPPORTS  (1<<3)  /* private is (nsISupports *) */
#define JSCLASS_IS_DOMJSCLASS           (1<<4)  /* objects are DOM */
#define JSCLASS_IMPLEMENTS_BARRIERS     (1<<5)  /* Correctly implements GC read
                                                   and write barriers */
#define JSCLASS_EMULATES_UNDEFINED      (1<<6)  /* objects of this class act
                                                   like the value undefined,
                                                   in some contexts */
#define JSCLASS_USERBIT1                (1<<7)  /* Reserved for embeddings. */

/*
 * To reserve slots fetched and stored via JS_Get/SetReservedSlot, bitwise-or
 * JSCLASS_HAS_RESERVED_SLOTS(n) into the initializer for JSClass.flags, where
 * n is a constant in [1, 255].  Reserved slots are indexed from 0 to n-1.
 */
#define JSCLASS_RESERVED_SLOTS_SHIFT    8       /* room for 8 flags below */
#define JSCLASS_RESERVED_SLOTS_WIDTH    8       /* and 16 above this field */
#define JSCLASS_RESERVED_SLOTS_MASK     JS_BITMASK(JSCLASS_RESERVED_SLOTS_WIDTH)
#define JSCLASS_HAS_RESERVED_SLOTS(n)   (((n) & JSCLASS_RESERVED_SLOTS_MASK)  \
                                         << JSCLASS_RESERVED_SLOTS_SHIFT)
#define JSCLASS_RESERVED_SLOTS(clasp)   (((clasp)->flags                      \
                                          >> JSCLASS_RESERVED_SLOTS_SHIFT)    \
                                         & JSCLASS_RESERVED_SLOTS_MASK)

#define JSCLASS_HIGH_FLAGS_SHIFT        (JSCLASS_RESERVED_SLOTS_SHIFT +       \
                                         JSCLASS_RESERVED_SLOTS_WIDTH)

#define JSCLASS_IS_ANONYMOUS            (1<<(JSCLASS_HIGH_FLAGS_SHIFT+0))
#define JSCLASS_IS_GLOBAL               (1<<(JSCLASS_HIGH_FLAGS_SHIFT+1))
#define JSCLASS_INTERNAL_FLAG2          (1<<(JSCLASS_HIGH_FLAGS_SHIFT+2))
#define JSCLASS_INTERNAL_FLAG3          (1<<(JSCLASS_HIGH_FLAGS_SHIFT+3))

/* Indicate whether the proto or ctor should be frozen. */
#define JSCLASS_FREEZE_PROTO            (1<<(JSCLASS_HIGH_FLAGS_SHIFT+4))
#define JSCLASS_FREEZE_CTOR             (1<<(JSCLASS_HIGH_FLAGS_SHIFT+5))

/* Reserved for embeddings. */
#define JSCLASS_USERBIT2                (1<<(JSCLASS_HIGH_FLAGS_SHIFT+6))
#define JSCLASS_USERBIT3                (1<<(JSCLASS_HIGH_FLAGS_SHIFT+7))

#define JSCLASS_BACKGROUND_FINALIZE     (1<<(JSCLASS_HIGH_FLAGS_SHIFT+8))

/*
 * Bits 26 through 31 are reserved for the CACHED_PROTO_KEY mechanism, see
 * below.
 */

/* Global flags. */
#define JSGLOBAL_FLAGS_CLEARED          0x1

/*
 * ECMA-262 requires that most constructors used internally create objects
 * with "the original Foo.prototype value" as their [[Prototype]] (__proto__)
 * member initial value.  The "original ... value" verbiage is there because
 * in ECMA-262, global properties naming class objects are read/write and
 * deleteable, for the most part.
 *
 * Implementing this efficiently requires that global objects have classes
 * with the following flags. Failure to use JSCLASS_GLOBAL_FLAGS was
 * prevously allowed, but is now an ES5 violation and thus unsupported.
 */
#define JSCLASS_GLOBAL_SLOT_COUNT      (JSProto_LIMIT * 3 + 25)
#define JSCLASS_GLOBAL_FLAGS_WITH_SLOTS(n)                                    \
    (JSCLASS_IS_GLOBAL | JSCLASS_HAS_RESERVED_SLOTS(JSCLASS_GLOBAL_SLOT_COUNT + (n)))
#define JSCLASS_GLOBAL_FLAGS                                                  \
    JSCLASS_GLOBAL_FLAGS_WITH_SLOTS(0)
#define JSCLASS_HAS_GLOBAL_FLAG_AND_SLOTS(clasp)                              \
  (((clasp)->flags & JSCLASS_IS_GLOBAL)                                       \
   && JSCLASS_RESERVED_SLOTS(clasp) >= JSCLASS_GLOBAL_SLOT_COUNT)

/* Fast access to the original value of each standard class's prototype. */
#define JSCLASS_CACHED_PROTO_SHIFT      (JSCLASS_HIGH_FLAGS_SHIFT + 10)
#define JSCLASS_CACHED_PROTO_WIDTH      6
#define JSCLASS_CACHED_PROTO_MASK       JS_BITMASK(JSCLASS_CACHED_PROTO_WIDTH)
#define JSCLASS_HAS_CACHED_PROTO(key)   (uint32_t(key) << JSCLASS_CACHED_PROTO_SHIFT)
#define JSCLASS_CACHED_PROTO_KEY(clasp) ((JSProtoKey)                         \
                                         (((clasp)->flags                     \
                                           >> JSCLASS_CACHED_PROTO_SHIFT)     \
                                          & JSCLASS_CACHED_PROTO_MASK))

/* Initializer for unused members of statically initialized JSClass structs. */
#define JSCLASS_NO_INTERNAL_MEMBERS     {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
#define JSCLASS_NO_OPTIONAL_MEMBERS     0,0,0,0,0,JSCLASS_NO_INTERNAL_MEMBERS

extern JS_PUBLIC_API(int)
JS_IdArrayLength(JSContext *cx, JSIdArray *ida);

extern JS_PUBLIC_API(jsid)
JS_IdArrayGet(JSContext *cx, JSIdArray *ida, int index);

extern JS_PUBLIC_API(void)
JS_DestroyIdArray(JSContext *cx, JSIdArray *ida);

namespace JS {

class AutoIdArray : private AutoGCRooter
{
  public:
    AutoIdArray(JSContext *cx, JSIdArray *ida
                MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
      : AutoGCRooter(cx, IDARRAY), context(cx), idArray(ida)
    {
        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    }
    ~AutoIdArray() {
        if (idArray)
            JS_DestroyIdArray(context, idArray);
    }
    bool operator!() {
        return !idArray;
    }
    jsid operator[](size_t i) const {
        JS_ASSERT(idArray);
        JS_ASSERT(i < length());
        return JS_IdArrayGet(context, idArray, i);
    }
    size_t length() const {
        return JS_IdArrayLength(context, idArray);
    }

    friend void AutoGCRooter::trace(JSTracer *trc);

    JSIdArray *steal() {
        JSIdArray *copy = idArray;
        idArray = NULL;
        return copy;
    }

  protected:
    inline void trace(JSTracer *trc);

  private:
    JSContext *context;
    JSIdArray *idArray;
    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER

    /* No copy or assignment semantics. */
    AutoIdArray(AutoIdArray &ida) MOZ_DELETE;
    void operator=(AutoIdArray &ida) MOZ_DELETE;
};

} /* namespace JS */

extern JS_PUBLIC_API(JSBool)
JS_ValueToId(JSContext *cx, jsval v, jsid *idp);

extern JS_PUBLIC_API(JSBool)
JS_IdToValue(JSContext *cx, jsid id, jsval *vp);

/*
 * JSNewResolveOp flag bits.
 */
#define JSRESOLVE_ASSIGNING     0x01    /* resolve on the left of assignment */

/*
 * Invoke the [[DefaultValue]] hook (see ES5 8.6.2) with the provided hint on
 * the specified object, computing a primitive default value for the object.
 * The hint must be JSTYPE_STRING, JSTYPE_NUMBER, or JSTYPE_VOID (no hint).  On
 * success the resulting value is stored in *vp.
 */
extern JS_PUBLIC_API(JSBool)
JS_DefaultValue(JSContext *cx, JSObject *obj, JSType hint, jsval *vp);

extern JS_PUBLIC_API(JSBool)
JS_PropertyStub(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id,
                JS::MutableHandle<JS::Value> vp);

extern JS_PUBLIC_API(JSBool)
JS_StrictPropertyStub(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, JSBool strict,
                      JS::MutableHandle<JS::Value> vp);

extern JS_PUBLIC_API(JSBool)
JS_DeletePropertyStub(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id,
                      JSBool *succeeded);

extern JS_PUBLIC_API(JSBool)
JS_EnumerateStub(JSContext *cx, JS::Handle<JSObject*> obj);

extern JS_PUBLIC_API(JSBool)
JS_ResolveStub(JSContext *cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id);

extern JS_PUBLIC_API(JSBool)
JS_ConvertStub(JSContext *cx, JS::Handle<JSObject*> obj, JSType type,
               JS::MutableHandle<JS::Value> vp);

struct JSConstDoubleSpec {
    double          dval;
    const char      *name;
    uint8_t         flags;
    uint8_t         spare[3];
};

typedef struct JSJitInfo JSJitInfo;

/*
 * Wrappers to replace {Strict,}PropertyOp for JSPropertySpecs. This will allow
 * us to pass one JSJitInfo per function with the property spec, without
 * additional field overhead.
 */
typedef struct JSStrictPropertyOpWrapper {
    JSStrictPropertyOp  op;
    const JSJitInfo     *info;
} JSStrictPropertyOpWrapper;

typedef struct JSPropertyOpWrapper {
    JSPropertyOp        op;
    const JSJitInfo     *info;
} JSPropertyOpWrapper;

/*
 * Wrapper to do as above, but for JSNatives for JSFunctionSpecs.
 */
typedef struct JSNativeWrapper {
    JSNative        op;
    const JSJitInfo *info;
} JSNativeWrapper;

/*
 * Macro static initializers which make it easy to pass no JSJitInfo as part of a
 * JSPropertySpec or JSFunctionSpec.
 */
#define JSOP_WRAPPER(op) {op, NULL}
#define JSOP_NULLWRAPPER JSOP_WRAPPER(NULL)

/*
 * To define an array element rather than a named property member, cast the
 * element's index to (const char *) and initialize name with it, and set the
 * JSPROP_INDEX bit in flags.
 */
struct JSPropertySpec {
    const char                  *name;
    int8_t                      tinyid;
    uint8_t                     flags;
    JSPropertyOpWrapper         getter;
    JSStrictPropertyOpWrapper   setter;
};

namespace JS {
namespace detail {

/* NEVER DEFINED, DON'T USE.  For use by JS_CAST_NATIVE_TO only. */
inline int CheckIsNative(JSNative native);

} // namespace detail
} // namespace JS

#define JS_CAST_NATIVE_TO(v, To) \
  (static_cast<void>(sizeof(JS::detail::CheckIsNative(v))), \
   reinterpret_cast<To>(v))

/*
 * JSPropertySpec uses JSAPI JSPropertyOp and JSStrictPropertyOp in function
 * signatures, but with JSPROP_NATIVE_ACCESSORS the actual values must be
 * JSNatives. To avoid widespread casting, have JS_PSG and JS_PSGS perform
 * type-safe casts.
 */
#define JS_PSG(name, getter, flags) \
    {name, 0, (flags) | JSPROP_SHARED | JSPROP_NATIVE_ACCESSORS, \
     JSOP_WRAPPER(JS_CAST_NATIVE_TO(getter, JSPropertyOp)), \
     JSOP_NULLWRAPPER}
#define JS_PSGS(name, getter, setter, flags) \
    {name, 0, (flags) | JSPROP_SHARED | JSPROP_NATIVE_ACCESSORS, \
     JSOP_WRAPPER(JS_CAST_NATIVE_TO(getter, JSPropertyOp)), \
     JSOP_WRAPPER(JS_CAST_NATIVE_TO(setter, JSStrictPropertyOp))}
#define JS_PS_END {0, 0, 0, JSOP_NULLWRAPPER, JSOP_NULLWRAPPER}

/*
 * To define a native function, set call to a JSNativeWrapper. To define a
 * self-hosted function, set selfHostedName to the name of a function
 * compiled during JSRuntime::initSelfHosting.
 */
struct JSFunctionSpec {
    const char      *name;
    JSNativeWrapper call;
    uint16_t        nargs;
    uint16_t        flags;
    const char      *selfHostedName;
};

/*
 * Terminating sentinel initializer to put at the end of a JSFunctionSpec array
 * that's passed to JS_DefineFunctions or JS_InitClass.
 */
#define JS_FS_END JS_FS(NULL,NULL,0,0)

/*
 * Initializer macros for a JSFunctionSpec array element. JS_FN (whose name
 * pays homage to the old JSNative/JSFastNative split) simply adds the flag
 * JSFUN_STUB_GSOPS. JS_FNINFO allows the simple adding of JSJitInfos.
 */
#define JS_FS(name,call,nargs,flags)                                          \
    {name, JSOP_WRAPPER(call), nargs, flags}
#define JS_FN(name,call,nargs,flags)                                          \
    {name, JSOP_WRAPPER(call), nargs, (flags) | JSFUN_STUB_GSOPS}
#define JS_FNINFO(name,call,info,nargs,flags)                                 \
    {name,{call,info},nargs,flags}

extern JS_PUBLIC_API(JSObject *)
JS_InitClass(JSContext *cx, JSObject *obj, JSObject *parent_proto,
             JSClass *clasp, JSNative constructor, unsigned nargs,
             const JSPropertySpec *ps, const JSFunctionSpec *fs,
             const JSPropertySpec *static_ps, const JSFunctionSpec *static_fs);

/*
 * Set up ctor.prototype = proto and proto.constructor = ctor with the
 * right property flags.
 */
extern JS_PUBLIC_API(JSBool)
JS_LinkConstructorAndPrototype(JSContext *cx, JSObject *ctor, JSObject *proto);

extern JS_PUBLIC_API(JSClass *)
JS_GetClass(JSObject *obj);

extern JS_PUBLIC_API(JSBool)
JS_InstanceOf(JSContext *cx, JSObject *obj, JSClass *clasp, jsval *argv);

extern JS_PUBLIC_API(JSBool)
JS_HasInstance(JSContext *cx, JSObject *obj, jsval v, JSBool *bp);

extern JS_PUBLIC_API(void *)
JS_GetPrivate(JSObject *obj);

extern JS_PUBLIC_API(void)
JS_SetPrivate(JSObject *obj, void *data);

extern JS_PUBLIC_API(void *)
JS_GetInstancePrivate(JSContext *cx, JSObject *obj, JSClass *clasp,
                      jsval *argv);

extern JS_PUBLIC_API(JSBool)
JS_GetPrototype(JSContext *cx, JSObject *obj, JSObject **protop);

extern JS_PUBLIC_API(JSBool)
JS_SetPrototype(JSContext *cx, JSObject *obj, JSObject *proto);

extern JS_PUBLIC_API(JSObject *)
JS_GetParent(JSObject *obj);

extern JS_PUBLIC_API(JSBool)
JS_SetParent(JSContext *cx, JSObject *obj, JSObject *parent);

extern JS_PUBLIC_API(JSObject *)
JS_GetConstructor(JSContext *cx, JSObject *proto);

/*
 * Get a unique identifier for obj, good for the lifetime of obj (even if it
 * is moved by a copying GC).  Return false on failure (likely out of memory),
 * and true with *idp containing the unique id on success.
 */
extern JS_PUBLIC_API(JSBool)
JS_GetObjectId(JSContext *cx, JSObject *obj, jsid *idp);

namespace JS {

enum {
    FreshZone,
    SystemZone,
    SpecificZones
};

typedef uintptr_t ZoneSpecifier;

inline ZoneSpecifier
SameZoneAs(JSObject *obj)
{
    JS_ASSERT(uintptr_t(obj) > SpecificZones);
    return ZoneSpecifier(obj);
}

struct JS_PUBLIC_API(CompartmentOptions) {
    ZoneSpecifier zoneSpec;
    bool hasVersion;
    JSVersion version;

    explicit CompartmentOptions() : zoneSpec(JS::FreshZone)
                                  , hasVersion(false)
                                  , version(JSVERSION_UNKNOWN)
    {}

    CompartmentOptions &setZone(ZoneSpecifier spec) { zoneSpec = spec; return *this; }
    CompartmentOptions &setVersion(JSVersion version_) { hasVersion = true; version = version_; return *this; }
};

} /* namespace JS */

extern JS_PUBLIC_API(JSObject *)
JS_NewGlobalObject(JSContext *cx, JSClass *clasp, JSPrincipals *principals,
                   const JS::CompartmentOptions &options = JS::CompartmentOptions());

extern JS_PUBLIC_API(JSObject *)
JS_NewObject(JSContext *cx, JSClass *clasp, JSObject *proto, JSObject *parent);

/* Queries the [[Extensible]] property of the object. */
extern JS_PUBLIC_API(JSBool)
JS_IsExtensible(JSObject *obj);

extern JS_PUBLIC_API(JSBool)
JS_IsNative(JSObject *obj);

extern JS_PUBLIC_API(JSRuntime *)
JS_GetObjectRuntime(JSObject *obj);

/*
 * Unlike JS_NewObject, JS_NewObjectWithGivenProto does not compute a default
 * proto if proto's actual parameter value is null.
 */
extern JS_PUBLIC_API(JSObject *)
JS_NewObjectWithGivenProto(JSContext *cx, JSClass *clasp, JSObject *proto,
                           JSObject *parent);

/*
 * Freeze obj, and all objects it refers to, recursively. This will not recurse