trunk/js/jsobj.h

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sw=4 et tw=78:
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef jsobj_h___
#define jsobj_h___
/*
 * JS object definitions.
 *
 * A JS object consists of a possibly-shared object descriptor containing
 * ordered property names, called the map; and a dense vector of property
 * values, called slots.  The map/slot pointer pair is GC'ed, while the map
 * is reference counted and the slot vector is malloc'ed.
 */
#include "jshash.h" /* Added by JSIFY */
#include "jsprvtd.h"
#include "jspubtd.h"

JS_BEGIN_EXTERN_C

/* For detailed comments on these function pointer types, see jsprvtd.h. */
struct JSObjectOps {
    /*
     * Custom shared object map for non-native objects. For native objects
     * this should be null indicating, that JSObject.map is an instance of
     * JSScope.
     */
    const JSObjectMap   *objectMap;

    /* Mandatory non-null function pointer members. */
    JSLookupPropOp      lookupProperty;
    JSDefinePropOp      defineProperty;
    JSPropertyIdOp      getProperty;
    JSPropertyIdOp      setProperty;
    JSAttributesOp      getAttributes;
    JSAttributesOp      setAttributes;
    JSPropertyIdOp      deleteProperty;
    JSConvertOp         defaultValue;
    JSNewEnumerateOp    enumerate;
    JSCheckAccessIdOp   checkAccess;

    /* Optionally non-null members start here. */
    JSObjectOp          thisObject;
    JSPropertyRefOp     dropProperty;
    JSNative            call;
    JSNative            construct;
    JSHasInstanceOp     hasInstance;
    JSTraceOp           trace;
    JSFinalizeOp        clear;
    JSGetRequiredSlotOp getRequiredSlot;
    JSSetRequiredSlotOp setRequiredSlot;
};

struct JSObjectMap {
    JSObjectOps *ops;           /* high level object operation vtable */
};

/* Shorthand macros for frequently-made calls. */
#define OBJ_LOOKUP_PROPERTY(cx,obj,id,objp,propp)                             \
    (obj)->map->ops->lookupProperty(cx,obj,id,objp,propp)
#define OBJ_DEFINE_PROPERTY(cx,obj,id,value,getter,setter,attrs,propp)        \
    (obj)->map->ops->defineProperty(cx,obj,id,value,getter,setter,attrs,propp)
#define OBJ_GET_PROPERTY(cx,obj,id,vp)                                        \
    (obj)->map->ops->getProperty(cx,obj,id,vp)
#define OBJ_SET_PROPERTY(cx,obj,id,vp)                                        \
    (obj)->map->ops->setProperty(cx,obj,id,vp)
#define OBJ_GET_ATTRIBUTES(cx,obj,id,prop,attrsp)                             \
    (obj)->map->ops->getAttributes(cx,obj,id,prop,attrsp)
#define OBJ_SET_ATTRIBUTES(cx,obj,id,prop,attrsp)                             \
    (obj)->map->ops->setAttributes(cx,obj,id,prop,attrsp)
#define OBJ_DELETE_PROPERTY(cx,obj,id,rval)                                   \
    (obj)->map->ops->deleteProperty(cx,obj,id,rval)
#define OBJ_DEFAULT_VALUE(cx,obj,hint,vp)                                     \
    (obj)->map->ops->defaultValue(cx,obj,hint,vp)
#define OBJ_ENUMERATE(cx,obj,enum_op,statep,idp)                              \
    (obj)->map->ops->enumerate(cx,obj,enum_op,statep,idp)
#define OBJ_CHECK_ACCESS(cx,obj,id,mode,vp,attrsp)                            \
    (obj)->map->ops->checkAccess(cx,obj,id,mode,vp,attrsp)

/* These four are time-optimized to avoid stub calls. */
#define OBJ_THIS_OBJECT(cx,obj)                                               \
    ((obj)->map->ops->thisObject                                              \
     ? (obj)->map->ops->thisObject(cx,obj)                                    \
     : (obj))
#define OBJ_DROP_PROPERTY(cx,obj,prop)                                        \
    ((obj)->map->ops->dropProperty                                            \
     ? (obj)->map->ops->dropProperty(cx,obj,prop)                             \
     : (void)0)
#define OBJ_GET_REQUIRED_SLOT(cx,obj,slot)                                    \
    ((obj)->map->ops->getRequiredSlot                                         \
     ? (obj)->map->ops->getRequiredSlot(cx, obj, slot)                        \
     : JSVAL_VOID)
#define OBJ_SET_REQUIRED_SLOT(cx,obj,slot,v)                                  \
    ((obj)->map->ops->setRequiredSlot                                         \
     ? (obj)->map->ops->setRequiredSlot(cx, obj, slot, v)                     \
     : JS_TRUE)

#define OBJ_TO_INNER_OBJECT(cx,obj)                                           \
    JS_BEGIN_MACRO                                                            \
        JSClass *clasp_ = OBJ_GET_CLASS(cx, obj);                             \
        if (clasp_->flags & JSCLASS_IS_EXTENDED) {                            \
            JSExtendedClass *xclasp_ = (JSExtendedClass*)clasp_;              \
            if (xclasp_->innerObject)                                         \
                obj = xclasp_->innerObject(cx, obj);                          \
        }                                                                     \
    JS_END_MACRO

#define OBJ_TO_OUTER_OBJECT(cx,obj)                                           \
    JS_BEGIN_MACRO                                                            \
        JSClass *clasp_ = OBJ_GET_CLASS(cx, obj);                             \
        if (clasp_->flags & JSCLASS_IS_EXTENDED) {                            \
            JSExtendedClass *xclasp_ = (JSExtendedClass*)clasp_;              \
            if (xclasp_->outerObject)                                         \
                obj = xclasp_->outerObject(cx, obj);                          \
        }                                                                     \
    JS_END_MACRO

#define JS_INITIAL_NSLOTS   5

/*
 * JSObject struct, with members sized to fit in 32 bytes on 32-bit targets,
 * 64 bytes on 64-bit systems. The JSFunction struct is an extension of this
 * struct allocated from a larger GC size-class.
 *
 * The classword member stores the JSClass pointer for this object, with the
 * least two bits encoding whether this object is a "delegate" or a "system"
 * object.
 *
 * An object is a delegate if it is on another object's prototype (linked by
 * JSSLOT_PROTO) or scope (JSSLOT_PARENT) chain, and therefore the delegate
 * might be asked implicitly to get or set a property on behalf of another
 * object. Delegates may be accessed directly too, as may any object, but only
 * those objects linked after the head of any prototype or scope chain are
 * flagged as delegates. This definition helps to optimize shape-based property
 * cache invalidation (see Purge{Scope,Proto}Chain in jsobj.cpp).
 *
 * The meaning of the system object bit is defined by the API client. It is
 * set in JS_NewSystemObject and is queried by JS_IsSystemObject (jsdbgapi.h),
 * but it has no intrinsic meaning to SpiderMonkey. Further, JSFILENAME_SYSTEM
 * and JS_FlagScriptFilenamePrefix (also exported via jsdbgapi.h) are intended
 * to be complementary to this bit, but it is up to the API client to implement
 * any such association.
 *
 * Both these classword tag bits are initially zero; they may be set or queried
 * using the STOBJ_(IS|SET)_(DELEGATE|SYSTEM) macros.
 *
 * The dslots member is null or a pointer into a dynamically allocated vector
 * of jsvals for reserved and dynamic slots. If dslots is not null, dslots[-1]
 * records the number of available slots.
 */
struct JSObject {
    JSObjectMap *map;                       /* propery map, see jsscope.h */
    jsuword     classword;                  /* classword, see above */
    jsval       fslots[JS_INITIAL_NSLOTS];  /* small number of fixed slots */
    jsval       *dslots;                    /* dynamically allocated slots */
};

#define JSSLOT_PROTO        0
#define JSSLOT_PARENT       1
#define JSSLOT_PRIVATE      2
#define JSSLOT_START(clasp) (((clasp)->flags & JSCLASS_HAS_PRIVATE)           \
                             ? JSSLOT_PRIVATE + 1                             \
                             : JSSLOT_PARENT + 1)

#define JSSLOT_FREE(clasp)  (JSSLOT_START(clasp)                              \
                             + JSCLASS_RESERVED_SLOTS(clasp))

/*
 * Maximum net gross capacity of the obj->dslots vector, excluding the additional
 * hidden slot used to store the length of the vector.
 */
#define MAX_DSLOTS_LENGTH   (JS_MAX(~(uint32)0, ~(size_t)0) / sizeof(jsval))

/*
 * STOBJ prefix means Single Threaded Object. Use the following fast macros to
 * directly manipulate slots in obj when only one thread can access obj, or
 * when accessing read-only slots within JS_INITIAL_NSLOTS.
 */

#define STOBJ_NSLOTS(obj)                                                     \
    ((obj)->dslots ? (uint32)(obj)->dslots[-1] : (uint32)JS_INITIAL_NSLOTS)

#define STOBJ_GET_SLOT(obj,slot)                                              \
    ((slot) < JS_INITIAL_NSLOTS                                               \
     ? (obj)->fslots[(slot)]                                                  \
     : (JS_ASSERT((slot) < (uint32)(obj)->dslots[-1]),                        \
        (obj)->dslots[(slot) - JS_INITIAL_NSLOTS]))

#define STOBJ_SET_SLOT(obj,slot,value)                                        \
    ((slot) < JS_INITIAL_NSLOTS                                               \
     ? (obj)->fslots[(slot)] = (value)                                        \
     : (JS_ASSERT((slot) < (uint32)(obj)->dslots[-1]),                        \
        (obj)->dslots[(slot) - JS_INITIAL_NSLOTS] = (value)))

#define STOBJ_GET_PROTO(obj)                                                  \
    JSVAL_TO_OBJECT((obj)->fslots[JSSLOT_PROTO])
#define STOBJ_SET_PROTO(obj,proto)                                            \
    (void)(STOBJ_NULLSAFE_SET_DELEGATE(proto),                                \
           (obj)->fslots[JSSLOT_PROTO] = OBJECT_TO_JSVAL(proto))
#define STOBJ_CLEAR_PROTO(obj)                                                \
    ((obj)->fslots[JSSLOT_PROTO] = JSVAL_NULL)

#define STOBJ_GET_PARENT(obj)                                                 \
    JSVAL_TO_OBJECT((obj)->fslots[JSSLOT_PARENT])
#define STOBJ_SET_PARENT(obj,parent)                                          \
    (void)(STOBJ_NULLSAFE_SET_DELEGATE(parent),                               \
           (obj)->fslots[JSSLOT_PARENT] = OBJECT_TO_JSVAL(parent))
#define STOBJ_CLEAR_PARENT(obj)                                               \
    ((obj)->fslots[JSSLOT_PARENT] = JSVAL_NULL)

/*
 * We use JSObject.classword to store both JSClass* and the delegate and system
 * flags in the two least significant bits. We do *not* synchronize updates of
 * obj->classword -- API clients must take care.
 */
#define JSSLOT_CLASS_MASK_BITS 3

static JS_ALWAYS_INLINE JSClass*
STOBJ_GET_CLASS(const JSObject* obj)
{
    return (JSClass *) (obj->classword & ~JSSLOT_CLASS_MASK_BITS);
}

#define STOBJ_IS_DELEGATE(obj)  (((obj)->classword & 1) != 0)
#define STOBJ_SET_DELEGATE(obj) ((obj)->classword |= 1)
#define STOBJ_NULLSAFE_SET_DELEGATE(obj)                                      \
    (!(obj) || STOBJ_SET_DELEGATE((JSObject*)obj))
#define STOBJ_IS_SYSTEM(obj)    (((obj)->classword & 2) != 0)
#define STOBJ_SET_SYSTEM(obj)   ((obj)->classword |= 2)

#define STOBJ_GET_PRIVATE(obj)                                                \
    (JS_ASSERT(JSVAL_IS_INT(STOBJ_GET_SLOT(obj, JSSLOT_PRIVATE))),            \
     JSVAL_TO_PRIVATE(STOBJ_GET_SLOT(obj, JSSLOT_PRIVATE)))

#define OBJ_CHECK_SLOT(obj,slot)                                              \
    JS_ASSERT_IF(OBJ_IS_NATIVE(obj), slot < OBJ_SCOPE(obj)->freeslot)

#define LOCKED_OBJ_GET_SLOT(obj,slot)                                         \
    (OBJ_CHECK_SLOT(obj, slot), STOBJ_GET_SLOT(obj, slot))
#define LOCKED_OBJ_SET_SLOT(obj,slot,value)                                   \
    (OBJ_CHECK_SLOT(obj, slot), STOBJ_SET_SLOT(obj, slot, value))

/*
 * NB: Don't call LOCKED_OBJ_SET_SLOT or STOBJ_SET_SLOT for a write to a slot
 * that may contain a function reference already, or where the new value is a
 * function ref, and the object's scope may be branded with a property cache
 * structural type capability that distinguishes versions of the object with
 * and without the function property. Instead use LOCKED_OBJ_WRITE_BARRIER or
 * a fast inline equivalent (JSOP_SETNAME/JSOP_SETPROP cases in jsinterp.c).
 */
#define LOCKED_OBJ_WRITE_BARRIER(cx,obj,slot,newval)                          \
    JS_BEGIN_MACRO                                                            \
        JSScope *scope_ = OBJ_SCOPE(obj);                                     \
        JS_ASSERT(scope_->object == (obj));                                   \
        GC_WRITE_BARRIER(cx, scope_, LOCKED_OBJ_GET_SLOT(obj, slot), newval); \
        LOCKED_OBJ_SET_SLOT(obj, slot, newval);                               \
    JS_END_MACRO

#define LOCKED_OBJ_GET_PROTO(obj) \
    (OBJ_CHECK_SLOT(obj, JSSLOT_PROTO), STOBJ_GET_PROTO(obj))
#define LOCKED_OBJ_SET_PROTO(obj,proto) \
    (OBJ_CHECK_SLOT(obj, JSSLOT_PROTO), STOBJ_SET_PROTO(obj, proto))

#define LOCKED_OBJ_GET_PARENT(obj) \
    (OBJ_CHECK_SLOT(obj, JSSLOT_PARENT), STOBJ_GET_PARENT(obj))
#define LOCKED_OBJ_SET_PARENT(obj,parent) \
    (OBJ_CHECK_SLOT(obj, JSSLOT_PARENT), STOBJ_SET_PARENT(obj, parent))

#define LOCKED_OBJ_GET_CLASS(obj) \
    STOBJ_GET_CLASS(obj)

#define LOCKED_OBJ_GET_PRIVATE(obj) \
    (OBJ_CHECK_SLOT(obj, JSSLOT_PRIVATE), STOBJ_GET_PRIVATE(obj))

#ifdef JS_THREADSAFE

/* Thread-safe functions and wrapper macros for accessing slots in obj. */
#define OBJ_GET_SLOT(cx,obj,slot)                                             \
    (OBJ_CHECK_SLOT(obj, slot),                                               \
     (OBJ_IS_NATIVE(obj) && OBJ_SCOPE(obj)->title.ownercx == cx)              \
     ? LOCKED_OBJ_GET_SLOT(obj, slot)                                         \
     : js_GetSlotThreadSafe(cx, obj, slot))

#define OBJ_SET_SLOT(cx,obj,slot,value)                                       \
    JS_BEGIN_MACRO                                                            \
        OBJ_CHECK_SLOT(obj, slot);                                            \
        if (OBJ_IS_NATIVE(obj) && OBJ_SCOPE(obj)->title.ownercx == cx)        \
            LOCKED_OBJ_WRITE_BARRIER(cx, obj, slot, value);                   \
        else                                                                  \
            js_SetSlotThreadSafe(cx, obj, slot, value);                       \
    JS_END_MACRO

/*
 * If thread-safe, define an OBJ_GET_SLOT wrapper that bypasses, for a native
 * object, the lock-free "fast path" test of (OBJ_SCOPE(obj)->ownercx == cx),
 * to avoid needlessly switching from lock-free to lock-full scope when doing
 * GC on a different context from the last one to own the scope.  The caller
 * in this case is probably a JSClass.mark function, e.g., fun_mark, or maybe
 * a finalizer.
 *
 * The GC runs only when all threads except the one on which the GC is active
 * are suspended at GC-safe points, so calling STOBJ_GET_SLOT from the GC's
 * thread is safe when rt->gcRunning is set. See jsgc.c for details.
 */
#define THREAD_IS_RUNNING_GC(rt, thread)                                      \
    ((rt)->gcRunning && (rt)->gcThread == (thread))

#define CX_THREAD_IS_RUNNING_GC(cx)                                           \
    THREAD_IS_RUNNING_GC((cx)->runtime, (cx)->thread)

#else   /* !JS_THREADSAFE */

#define OBJ_GET_SLOT(cx,obj,slot)       LOCKED_OBJ_GET_SLOT(obj,slot)
#define OBJ_SET_SLOT(cx,obj,slot,value) LOCKED_OBJ_WRITE_BARRIER(cx,obj,slot, \
                                                                 value)

#endif /* !JS_THREADSAFE */

/* Thread-safe delegate, proto, parent, and class access macros. */
#define OBJ_IS_DELEGATE(cx,obj)         STOBJ_IS_DELEGATE(obj)
#define OBJ_SET_DELEGATE(cx,obj)        STOBJ_SET_DELEGATE(obj)

#define OBJ_GET_PROTO(cx,obj)           STOBJ_GET_PROTO(obj)
#define OBJ_SET_PROTO(cx,obj,proto)     STOBJ_SET_PROTO(obj, proto)
#define OBJ_CLEAR_PROTO(cx,obj)         STOBJ_CLEAR_PROTO(obj)

#define OBJ_GET_PARENT(cx,obj)          STOBJ_GET_PARENT(obj)
#define OBJ_SET_PARENT(cx,obj,parent)   STOBJ_SET_PARENT(obj, parent)
#define OBJ_CLEAR_PARENT(cx,obj)        STOBJ_CLEAR_PARENT(obj)

/*
 * Class is invariant and comes from the fixed clasp member. Thus no locking
 * is necessary to read it. Same for the private slot.
 */
#define OBJ_GET_CLASS(cx,obj)           STOBJ_GET_CLASS(obj)
#define OBJ_GET_PRIVATE(cx,obj)         STOBJ_GET_PRIVATE(obj)

/*
 * Test whether the object is native. FIXME bug 492938: consider how it would
 * affect the performance to do just the !ops->objectMap check.
 */
#define OPS_IS_NATIVE(ops)                                                    \
    JS_LIKELY((ops) == &js_ObjectOps || !(ops)->objectMap)

#define OBJ_IS_NATIVE(obj)  OPS_IS_NATIVE((obj)->map->ops)

extern JS_FRIEND_DATA(JSObjectOps) js_ObjectOps;
extern JS_FRIEND_DATA(JSObjectOps) js_WithObjectOps;
extern JSClass  js_ObjectClass;
extern JSClass  js_WithClass;
extern JSClass  js_BlockClass;

/*
 * Block scope object macros.  The slots reserved by js_BlockClass are:
 *
 *   JSSLOT_PRIVATE       JSStackFrame *    active frame pointer or null
 *   JSSLOT_BLOCK_DEPTH   int               depth of block slots in frame
 *
 * After JSSLOT_BLOCK_DEPTH come one or more slots for the block locals.
 *
 * A With object is like a Block object, in that both have one reserved slot
 * telling the stack depth of the relevant slots (the slot whose value is the
 * object named in the with statement, the slots containing the block's local
 * variables); and both have a private slot referring to the JSStackFrame in
 * whose activation they were created (or null if the with or block object
 * outlives the frame).
 */
#define JSSLOT_BLOCK_DEPTH      (JSSLOT_PRIVATE + 1)

#define OBJ_IS_CLONED_BLOCK(obj)                                              \
    (OBJ_SCOPE(obj)->object != (obj))
#define OBJ_BLOCK_COUNT(cx,obj)                                               \
    (OBJ_SCOPE(obj)->entryCount)
#define OBJ_BLOCK_DEPTH(cx,obj)                                               \
    JSVAL_TO_INT(STOBJ_GET_SLOT(obj, JSSLOT_BLOCK_DEPTH))
#define OBJ_SET_BLOCK_DEPTH(cx,obj,depth)                                     \
    STOBJ_SET_SLOT(obj, JSSLOT_BLOCK_DEPTH, INT_TO_JSVAL(depth))

/*
 * To make sure this slot is well-defined, always call js_NewWithObject to
 * create a With object, don't call js_NewObject directly.  When creating a
 * With object that does not correspond to a stack slot, pass -1 for depth.
 *
 * When popping the stack across this object's "with" statement, client code
 * must call JS_SetPrivate(cx, withobj, NULL).
 */
extern JS_REQUIRES_STACK JSObject *
js_NewWithObject(JSContext *cx, JSObject *proto, JSObject *parent, jsint depth);

/*
 * Create a new block scope object not linked to any proto or parent object.
 * Blocks are created by the compiler to reify let blocks and comprehensions.
 * Only when dynamic scope is captured do they need to be cloned and spliced
 * into an active scope chain.
 */
extern JSObject *
js_NewBlockObject(JSContext *cx);

extern JSObject *
js_CloneBlockObject(JSContext *cx, JSObject *proto, JSObject *parent,
                    JSStackFrame *fp);

extern JS_REQUIRES_STACK JSBool
js_PutBlockObject(JSContext *cx, JSBool normalUnwind);

JSBool
js_XDRBlockObject(JSXDRState *xdr, JSObject **objp);

struct JSSharpObjectMap {
    jsrefcount  depth;
    jsatomid    sharpgen;
    JSHashTable *table;
};

#define SHARP_BIT       ((jsatomid) 1)
#define BUSY_BIT        ((jsatomid) 2)
#define SHARP_ID_SHIFT  2
#define IS_SHARP(he)    (JS_PTR_TO_UINT32((he)->value) & SHARP_BIT)
#define MAKE_SHARP(he)  ((he)->value = JS_UINT32_TO_PTR(JS_PTR_TO_UINT32((he)->value)|SHARP_BIT))
#define IS_BUSY(he)     (JS_PTR_TO_UINT32((he)->value) & BUSY_BIT)
#define MAKE_BUSY(he)   ((he)->value = JS_UINT32_TO_PTR(JS_PTR_TO_UINT32((he)->value)|BUSY_BIT))
#define CLEAR_BUSY(he)  ((he)->value = JS_UINT32_TO_PTR(JS_PTR_TO_UINT32((he)->value)&~BUSY_BIT))

extern JSHashEntry *
js_EnterSharpObject(JSContext *cx, JSObject *obj, JSIdArray **idap,
                    jschar **sp);

extern void
js_LeaveSharpObject(JSContext *cx, JSIdArray **idap);

/*
 * Mark objects stored in map if GC happens between js_EnterSharpObject
 * and js_LeaveSharpObject. GC calls this when map->depth > 0.
 */
extern void
js_TraceSharpMap(JSTracer *trc, JSSharpObjectMap *map);

extern JSBool
js_HasOwnPropertyHelper(JSContext *cx, JSLookupPropOp lookup, uintN argc,
                        jsval *vp);

extern JSBool
js_HasOwnProperty(JSContext *cx, JSLookupPropOp lookup, JSObject *obj, jsid id,
                  jsval *vp);

extern JSBool
js_PropertyIsEnumerable(JSContext *cx, JSObject *obj, jsid id, jsval *vp);

extern JSObject *
js_InitEval(JSContext *cx, JSObject *obj);

extern JSObject *
js_InitObjectClass(JSContext *cx, JSObject *obj);

extern JSObject *
js_InitClass(JSContext *cx, JSObject *obj, JSObject *parent_proto,
             JSClass *clasp, JSNative constructor, uintN nargs,
             JSPropertySpec *ps, JSFunctionSpec *fs,
             JSPropertySpec *static_ps, JSFunctionSpec *static_fs);

/*
 * Select Object.prototype method names shared between jsapi.cpp and jsobj.cpp.
 */
extern const char js_watch_str[];
extern const char js_unwatch_str[];
extern const char js_hasOwnProperty_str[];
extern const char js_isPrototypeOf_str[];
extern const char js_propertyIsEnumerable_str[];
extern const char js_defineGetter_str[];
extern const char js_defineSetter_str[];
extern const char js_lookupGetter_str[];
extern const char js_lookupSetter_str[];

extern JSBool
js_GetClassId(JSContext *cx, JSClass *clasp, jsid *idp);

extern JSObject *
js_NewObject(JSContext *cx, JSClass *clasp, JSObject *proto, JSObject *parent,
             uintN objectSize);

/*
 * See jsapi.h, JS_NewObjectWithGivenProto.
 *
 * objectSize is either the explicit size for the allocated object or 0
 * indicating to use the default size based on object's class.
 */
extern JSObject *
js_NewObjectWithGivenProto(JSContext *cx, JSClass *clasp, JSObject *proto,
                           JSObject *parent, uintN objectSize);

/*
 * Allocate a new native object and initialize all fslots with JSVAL_VOID
 * starting with the specified slot. The parent slot is set to the value of
 * proto's parent slot.
 *
 * Note that this is the correct global object for native class instances, but
 * not for user-defined functions called as constructors.  Functions used as
 * constructors must create instances parented by the parent of the function
 * object, not by the parent of its .prototype object value.
 */
extern JSObject*
js_NewNativeObject(JSContext *cx, JSClass *clasp, JSObject *proto, uint32 slot);

/*
 * Fast access to immutable standard objects (constructors and prototypes).
 */
extern JSBool
js_GetClassObject(JSContext *cx, JSObject *obj, JSProtoKey key,
                  JSObject **objp);

extern JSBool
js_SetClassObject(JSContext *cx, JSObject *obj, JSProtoKey key, JSObject *cobj);

extern JSBool
js_FindClassObject(JSContext *cx, JSObject *start, jsid id, jsval *vp);

extern JSObject *
js_ConstructObject(JSContext *cx, JSClass *clasp, JSObject *proto,
                   JSObject *parent, uintN argc, jsval *argv);

extern void
js_FinalizeObject(JSContext *cx, JSObject *obj);

extern JSBool
js_AllocSlot(JSContext *cx, JSObject *obj, uint32 *slotp);

extern void
js_FreeSlot(JSContext *cx, JSObject *obj, uint32 slot);

/* JSVAL_INT_MAX as a string */
#define JSVAL_INT_MAX_STRING "1073741823"

/*
 * Convert string indexes that convert to int jsvals as ints to save memory.
 * Care must be taken to use this macro every time a property name is used, or
 * else double-sets, incorrect property cache misses, or other mistakes could
 * occur.
 */
#define CHECK_FOR_STRING_INDEX(id)                                            \
    JS_BEGIN_MACRO                                                            \
        if (JSID_IS_ATOM(id)) {                                               \
            JSAtom *atom_ = JSID_TO_ATOM(id);                                 \
            JSString *str_ = ATOM_TO_STRING(atom_);                           \
            const jschar *s_ = JSFLATSTR_CHARS(str_);                         \
            JSBool negative_ = (*s_ == '-');                                  \
            if (negative_) s_++;                                              \
            if (JS7_ISDEC(*s_)) {                                             \
                size_t n_ = JSFLATSTR_LENGTH(str_) - negative_;               \
                if (n_ <= sizeof(JSVAL_INT_MAX_STRING) - 1)                   \
                    id = js_CheckForStringIndex(id, s_, s_ + n_, negative_);  \
            }                                                                 \
        }                                                                     \
    JS_END_MACRO

extern jsid
js_CheckForStringIndex(jsid id, const jschar *cp, const jschar *end,
                       JSBool negative);

/*
 * js_PurgeScopeChain does nothing if obj is not itself a prototype or parent
 * scope, else it reshapes the scope and prototype chains it links. It calls
 * js_PurgeScopeChainHelper, which asserts that obj is flagged as a delegate
 * (i.e., obj has ever been on a prototype or parent chain).
 */
extern void
js_PurgeScopeChainHelper(JSContext *cx, JSObject *obj, jsid id);

#ifdef __cplusplus /* Aargh, libgjs, bug 492720. */
static JS_INLINE void
js_PurgeScopeChain(JSContext *cx, JSObject *obj, jsid id)
{
    if (OBJ_IS_DELEGATE(cx, obj))
        js_PurgeScopeChainHelper(cx, obj, id);
}
#endif

/*
 * Find or create a property named by id in obj's scope, with the given getter
 * and setter, slot, attributes, and other members.
 */
extern JSScopeProperty *
js_AddNativeProperty(JSContext *cx, JSObject *obj, jsid id,
                     JSPropertyOp getter, JSPropertyOp setter, uint32 slot,
                     uintN attrs, uintN flags, intN shortid);

/*
 * Change sprop to have the given attrs, getter, and setter in scope, morphing
 * it into a potentially new JSScopeProperty.  Return a pointer to the changed
 * or identical property.
 */
extern JSScopeProperty *
js_ChangeNativePropertyAttrs(JSContext *cx, JSObject *obj,
                             JSScopeProperty *sprop, uintN attrs, uintN mask,
                             JSPropertyOp getter, JSPropertyOp setter);

/*
 * On error, return false.  On success, if propp is non-null, return true with
 * obj locked and with a held property in *propp; if propp is null, return true
 * but release obj's lock first.  Therefore all callers who pass non-null propp
 * result parameters must later call OBJ_DROP_PROPERTY(cx, obj, *propp) both to
 * drop the held property, and to release the lock on obj.
 */
extern JSBool
js_DefineProperty(JSContext *cx, JSObject *obj, jsid id, jsval value,
                  JSPropertyOp getter, JSPropertyOp setter, uintN attrs,
                  JSProperty **propp);

#ifdef __cplusplus /* FIXME: bug 442399 removes this LiveConnect requirement. */

/*
 * Flags for the defineHow parameter of js_DefineNativeProperty.
 */
const uintN JSDNP_CACHE_RESULT = 1; /* an interpreter call from JSOP_INITPROP */
const uintN JSDNP_DONT_PURGE   = 2; /* suppress js_PurgeScopeChain */

extern JSBool
js_DefineNativeProperty(JSContext *cx, JSObject *obj, jsid id, jsval value,
                        JSPropertyOp getter, JSPropertyOp setter, uintN attrs,
                        uintN flags, intN shortid, JSProperty **propp,
                        uintN defineHow = 0);
#endif

/*
 * Unlike js_DefineProperty, propp must be non-null. On success, and if id was
 * found, return true with *objp non-null and locked, and with a held property
 * stored in *propp. If successful but id was not found, return true with both
 * *objp and *propp null. Therefore all callers who receive a non-null *propp
 * must later call OBJ_DROP_PROPERTY(cx, *objp, *propp).
 */
extern JS_FRIEND_API(JSBool)
js_LookupProperty(JSContext *cx, JSObject *obj, jsid id, JSObject **objp,
                  JSProperty **propp);

/*
 * Specialized subroutine that allows caller to preset JSRESOLVE_* flags and
 * returns the index along the prototype chain in which *propp was found, or
 * the last index if not found, or -1 on error.
 */
extern int
js_LookupPropertyWithFlags(JSContext *cx, JSObject *obj, jsid id, uintN flags,
                           JSObject **objp, JSProperty **propp);

/*
 * If cacheResult is false, return JS_NO_PROP_CACHE_FILL on success.
 */
extern JSPropCacheEntry *
js_FindPropertyHelper(JSContext *cx, jsid id, JSBool cacheResult,
                      JSObject **objp, JSObject **pobjp, JSProperty **propp);

/*
 * Return the index along the scope chain in which id was found, or the last
 * index if not found, or -1 on error.
 */
extern JS_FRIEND_API(JSBool)
js_FindProperty(JSContext *cx, jsid id, JSObject **objp, JSObject **pobjp,
                JSProperty **propp);

extern JS_REQUIRES_STACK JSObject *
js_FindIdentifierBase(JSContext *cx, JSObject *scopeChain, jsid id);

extern JSObject *
js_FindVariableScope(JSContext *cx, JSFunction **funp);

/*
 * NB: js_NativeGet and js_NativeSet are called with the scope containing sprop
 * (pobj's scope for Get, obj's for Set) locked, and on successful return, that
 * scope is again locked.  But on failure, both functions return false with the
 * scope containing sprop unlocked.
 */
extern JSBool
js_NativeGet(JSContext *cx, JSObject *obj, JSObject *pobj,
             JSScopeProperty *sprop, jsval *vp);

extern JSBool
js_NativeSet(JSContext *cx, JSObject *obj, JSScopeProperty *sprop, jsval *vp);

extern JSBool
js_GetPropertyHelper(JSContext *cx, JSObject *obj, jsid id, JSBool cacheResult,
                     jsval *vp);

extern JSBool
js_GetProperty(JSContext *cx, JSObject *obj, jsid id, jsval *vp);

extern JSBool
js_GetMethod(JSContext *cx, JSObject *obj, jsid id, JSBool cacheResult,
             jsval *vp);

/*
 * Check whether it is OK to assign an undeclared property of the global
 * object at the current script PC.
 */
extern JS_FRIEND_API(JSBool)
js_CheckUndeclaredVarAssignment(JSContext *cx);

extern JSBool
js_SetPropertyHelper(JSContext *cx, JSObject *obj, jsid id, JSBool cacheResult,
                     jsval *vp);

extern JSBool
js_SetProperty(JSContext *cx, JSObject *obj, jsid id, jsval *vp);

extern JSBool
js_GetAttributes(JSContext *cx, JSObject *obj, jsid id, JSProperty *prop,
                 uintN *attrsp);

extern JSBool
js_SetAttributes(JSContext *cx, JSObject *obj, jsid id, JSProperty *prop,
                 uintN *attrsp);

extern JSBool
js_DeleteProperty(JSContext *cx, JSObject *obj, jsid id, jsval *rval);

extern JSBool
js_DefaultValue(JSContext *cx, JSObject *obj, JSType hint, jsval *vp);

extern JSBool
js_Enumerate(JSContext *cx, JSObject *obj, JSIterateOp enum_op,
             jsval *statep, jsid *idp);

extern void
js_TraceNativeEnumerators(JSTracer *trc);

extern JSBool
js_CheckAccess(JSContext *cx, JSObject *obj, jsid id, JSAccessMode mode,
               jsval *vp, uintN *attrsp);

extern JSBool
js_Call(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);

extern JSBool
js_Construct(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
             jsval *rval);

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

extern JSBool
js_SetProtoOrParent(JSContext *cx, JSObject *obj, uint32 slot, JSObject *pobj,
                    JSBool checkForCycles);

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

extern JSBool
js_GetClassPrototype(JSContext *cx, JSObject *scope, jsid id,
                     JSObject **protop);

extern JSBool
js_SetClassPrototype(JSContext *cx, JSObject *ctor, JSObject *proto,
                     uintN attrs);

/*
 * Wrap boolean, number or string as Boolean, Number or String object.
 * *vp must not be an object, null or undefined.
 */
extern JSBool
js_PrimitiveToObject(JSContext *cx, jsval *vp);

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

extern JSObject *
js_ValueToNonNullObject(JSContext *cx, jsval v);

extern JSBool
js_TryValueOf(JSContext *cx, JSObject *obj, JSType type, jsval *rval);

extern JSBool
js_TryMethod(JSContext *cx, JSObject *obj, JSAtom *atom,
             uintN argc, jsval *argv, jsval *rval);

extern JSBool
js_XDRObject(JSXDRState *xdr, JSObject **objp);

extern void
js_TraceObject(JSTracer *trc, JSObject *obj);

extern void
js_PrintObjectSlotName(JSTracer *trc, char *buf, size_t bufsize);

extern void
js_Clear(JSContext *cx, JSObject *obj);

extern jsval
js_GetRequiredSlot(JSContext *cx, JSObject *obj, uint32 slot);

extern JSBool
js_SetRequiredSlot(JSContext *cx, JSObject *obj, uint32 slot, jsval v);

/*
 * Precondition: obj must be locked.
 */
extern JSBool
js_ReallocSlots(JSContext *cx, JSObject *obj, uint32 nslots,
                JSBool exactAllocation);

extern JSObject *
js_CheckScopeChainValidity(JSContext *cx, JSObject *scopeobj, const char *caller);

extern JSBool
js_CheckPrincipalsAccess(JSContext *cx, JSObject *scopeobj,
                         JSPrincipals *principals, JSAtom *caller);

/* Infallible -- returns its argument if there is no wrapped object. */
extern JSObject *
js_GetWrappedObject(JSContext *cx, JSObject *obj);

/* NB: Infallible. */
extern const char *
js_ComputeFilename(JSContext *cx, JSStackFrame *caller,
                   JSPrincipals *principals, uintN *linenop);

/* Infallible, therefore cx is last parameter instead of first. */
extern JSBool
js_IsCallable(JSObject *obj, JSContext *cx);

void
js_ReportGetterOnlyAssignment(JSContext *cx);

extern JS_FRIEND_API(JSBool)
js_GetterOnlyPropertyStub(JSContext *cx, JSObject *obj, jsval id, jsval *vp);

#ifdef DEBUG
JS_FRIEND_API(void) js_DumpChars(const jschar *s, size_t n);
JS_FRIEND_API(void) js_DumpString(JSString *str);
JS_FRIEND_API(void) js_DumpAtom(JSAtom *atom);
JS_FRIEND_API(void) js_DumpValue(jsval val);
JS_FRIEND_API(void) js_DumpId(jsid id);
JS_FRIEND_API(void) js_DumpObject(JSObject *obj);
#endif

JS_END_EXTERN_C

#endif /* jsobj_h___ */