/*
* duk_hobject property access functionality.
*
* This is very central functionality for size, performance, and compliance.
* It is also rather intricate; see hobject-algorithms.rst for discussion on
* the algorithms and memory-management.rst for discussion on refcounts and
* side effect issues.
*
* Notes:
*
* - It might be tempting to assert "refcount nonzero" for objects
* being operated on, but that's not always correct: objects with
* a zero refcount may be operated on by the refcount implementation
* (finalization) for instance. Hence, no refcount assertions are made.
*
* - Many operations (memory allocation, identifier operations, etc)
* may cause arbitrary side effects (e.g. through GC and finalization).
* These side effects may invalidate duk_tval pointers which point to
* areas subject to reallocation (like value stack). Heap objects
* themselves have stable pointers. Holding heap object pointers or
* duk_tval copies is not problematic with respect to side effects;
* care must be taken when holding and using argument duk_tval pointers.
*
* - If a finalizer is executed, it may operate on the the same object
* we're currently dealing with. For instance, the finalizer might
* delete a certain property which has already been looked up and
* confirmed to exist. Ideally finalizers would be disabled if GC
* happens during property access. At the moment property table realloc
* disables finalizers, and all DECREFs may cause arbitrary changes so
* handle DECREF carefully.
*
* - The order of operations for a DECREF matters. When DECREF is executed,
* the entire object graph must be consistent; note that a refzero may
* lead to a mark-and-sweep through a refcount finalizer. Use NORZ macros
* and an explicit DUK_REFZERO_CHECK_xxx() if achieving correct order is hard.
*/
/*
* XXX: array indices are mostly typed as duk_uint32_t here; duk_uarridx_t
* might be more appropriate.
*/
#include "third_party/duktape/duk_internal.h"
/*
* Local defines
*/
#define DUK__NO_ARRAY_INDEX DUK_HSTRING_NO_ARRAY_INDEX
/* Marker values for hash part. */
#define DUK__HASH_UNUSED DUK_HOBJECT_HASHIDX_UNUSED
#define DUK__HASH_DELETED DUK_HOBJECT_HASHIDX_DELETED
/* Valstack space that suffices for all local calls, excluding any recursion
* into ECMAScript or Duktape/C calls (Proxy, getters, etc).
*/
#define DUK__VALSTACK_SPACE 10
/* Valstack space allocated especially for proxy lookup which does a
* recursive property lookup.
*/
#define DUK__VALSTACK_PROXY_LOOKUP 20
/*
* Local prototypes
*/
DUK_LOCAL_DECL duk_bool_t duk__check_arguments_map_for_get(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *temp_desc);
DUK_LOCAL_DECL void duk__check_arguments_map_for_put(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *temp_desc, duk_bool_t throw_flag);
DUK_LOCAL_DECL void duk__check_arguments_map_for_delete(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *temp_desc);
DUK_LOCAL_DECL duk_bool_t duk__handle_put_array_length_smaller(duk_hthread *thr, duk_hobject *obj, duk_uint32_t old_len, duk_uint32_t new_len, duk_bool_t force_flag, duk_uint32_t *out_result_len);
DUK_LOCAL_DECL duk_bool_t duk__handle_put_array_length(duk_hthread *thr, duk_hobject *obj);
DUK_LOCAL_DECL duk_bool_t duk__get_propdesc(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *out_desc, duk_small_uint_t flags);
DUK_LOCAL_DECL duk_bool_t duk__get_own_propdesc_raw(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_uint32_t arr_idx, duk_propdesc *out_desc, duk_small_uint_t flags);
DUK_LOCAL_DECL void duk__abandon_array_part(duk_hthread *thr, duk_hobject *obj);
DUK_LOCAL_DECL void duk__grow_props_for_array_item(duk_hthread *thr, duk_hobject *obj, duk_uint32_t highest_arr_idx);
/*
* Misc helpers
*/
/* Convert a duk_tval number (caller checks) to a 32-bit index. Returns
* DUK__NO_ARRAY_INDEX if the number is not whole or not a valid array
* index.
*/
/* XXX: for fastints, could use a variant which assumes a double duk_tval
* (and doesn't need to check for fastint again).
*/
DUK_LOCAL duk_uint32_t duk__tval_number_to_arr_idx(duk_tval *tv) {
duk_double_t dbl;
duk_uint32_t idx;
DUK_ASSERT(tv != NULL);
DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv));
/* -0 is accepted here as index 0 because ToString(-0) == "0" which is
* in canonical form and thus an array index.
*/
dbl = DUK_TVAL_GET_NUMBER(tv);
idx = (duk_uint32_t) dbl;
if (duk_double_equals((duk_double_t) idx, dbl)) {
/* Is whole and within 32 bit range. If the value happens to be 0xFFFFFFFF,
* it's not a valid array index but will then match DUK__NO_ARRAY_INDEX.
*/
return idx;
}
return DUK__NO_ARRAY_INDEX;
}
#if defined(DUK_USE_FASTINT)
/* Convert a duk_tval fastint (caller checks) to a 32-bit index. */
DUK_LOCAL duk_uint32_t duk__tval_fastint_to_arr_idx(duk_tval *tv) {
duk_int64_t t;
DUK_ASSERT(tv != NULL);
DUK_ASSERT(DUK_TVAL_IS_FASTINT(tv));
t = DUK_TVAL_GET_FASTINT(tv);
if (((duk_uint64_t) t & ~DUK_U64_CONSTANT(0xffffffff)) != 0) {
/* Catches >0x100000000 and negative values. */
return DUK__NO_ARRAY_INDEX;
}
/* If the value happens to be 0xFFFFFFFF, it's not a valid array index
* but will then match DUK__NO_ARRAY_INDEX.
*/
return (duk_uint32_t) t;
}
#endif /* DUK_USE_FASTINT */
/* Convert a duk_tval on the value stack (in a trusted index we don't validate)
* to a string or symbol using ES2015 ToPropertyKey():
* http://www.ecma-international.org/ecma-262/6.0/#sec-topropertykey.
*
* Also check if it's a valid array index and return that (or DUK__NO_ARRAY_INDEX
* if not).
*/
DUK_LOCAL duk_uint32_t duk__to_property_key(duk_hthread *thr, duk_idx_t idx, duk_hstring **out_h) {
duk_uint32_t arr_idx;
duk_hstring *h;
duk_tval *tv_dst;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(out_h != NULL);
DUK_ASSERT(duk_is_valid_index(thr, idx));
DUK_ASSERT(idx < 0);
/* XXX: The revised ES2015 ToPropertyKey() handling (ES5.1 was just
* ToString()) involves a ToPrimitive(), a symbol check, and finally
* a ToString(). Figure out the best way to have a good fast path
* but still be compliant and share code.
*/
tv_dst = DUK_GET_TVAL_NEGIDX(thr, idx); /* intentionally unvalidated */
if (DUK_TVAL_IS_STRING(tv_dst)) {
/* Most important path: strings and plain symbols are used as
* is. For symbols the array index check below is unnecessary
* (they're never valid array indices) but checking that the
* string is a symbol would make the plain string path slower
* unnecessarily.
*/
h = DUK_TVAL_GET_STRING(tv_dst);
} else {
h = duk_to_property_key_hstring(thr, idx);
}
DUK_ASSERT(h != NULL);
*out_h = h;
arr_idx = DUK_HSTRING_GET_ARRIDX_FAST(h);
return arr_idx;
}
DUK_LOCAL duk_uint32_t duk__push_tval_to_property_key(duk_hthread *thr, duk_tval *tv_key, duk_hstring **out_h) {
duk_push_tval(thr, tv_key); /* XXX: could use an unsafe push here */
return duk__to_property_key(thr, -1, out_h);
}
/* String is an own (virtual) property of a plain buffer. */
DUK_LOCAL duk_bool_t duk__key_is_plain_buf_ownprop(duk_hthread *thr, duk_hbuffer *buf, duk_hstring *key, duk_uint32_t arr_idx) {
DUK_UNREF(thr);
/* Virtual index properties. Checking explicitly for
* 'arr_idx != DUK__NO_ARRAY_INDEX' is not necessary
* because DUK__NO_ARRAY_INDEXi is always larger than
* maximum allowed buffer size.
*/
DUK_ASSERT(DUK__NO_ARRAY_INDEX >= DUK_HBUFFER_GET_SIZE(buf));
if (arr_idx < DUK_HBUFFER_GET_SIZE(buf)) {
return 1;
}
/* Other virtual properties. */
return (key == DUK_HTHREAD_STRING_LENGTH(thr));
}
/*
* Helpers for managing property storage size
*/
/* Get default hash part size for a certain entry part size. */
#if defined(DUK_USE_HOBJECT_HASH_PART)
DUK_LOCAL duk_uint32_t duk__get_default_h_size(duk_uint32_t e_size) {
DUK_ASSERT(e_size <= DUK_HOBJECT_MAX_PROPERTIES);
if (e_size >= DUK_USE_HOBJECT_HASH_PROP_LIMIT) {
duk_uint32_t res;
duk_uint32_t tmp;
/* Hash size should be 2^N where N is chosen so that 2^N is
* larger than e_size. Extra shifting is used to ensure hash
* is relatively sparse.
*/
tmp = e_size;
res = 2; /* Result will be 2 ** (N + 1). */
while (tmp >= 0x40) {
tmp >>= 6;
res <<= 6;
}
while (tmp != 0) {
tmp >>= 1;
res <<= 1;
}
DUK_ASSERT((DUK_HOBJECT_MAX_PROPERTIES << 2U) > DUK_HOBJECT_MAX_PROPERTIES); /* Won't wrap, even shifted by 2. */
DUK_ASSERT(res > e_size);
return res;
} else {
return 0;
}
}
#endif /* USE_PROP_HASH_PART */
/* Get minimum entry part growth for a certain size. */
DUK_LOCAL duk_uint32_t duk__get_min_grow_e(duk_uint32_t e_size) {
duk_uint32_t res;
res = (e_size + DUK_USE_HOBJECT_ENTRY_MINGROW_ADD) / DUK_USE_HOBJECT_ENTRY_MINGROW_DIVISOR;
DUK_ASSERT(res >= 1); /* important for callers */
return res;
}
/* Get minimum array part growth for a certain size. */
DUK_LOCAL duk_uint32_t duk__get_min_grow_a(duk_uint32_t a_size) {
duk_uint32_t res;
res = (a_size + DUK_USE_HOBJECT_ARRAY_MINGROW_ADD) / DUK_USE_HOBJECT_ARRAY_MINGROW_DIVISOR;
DUK_ASSERT(res >= 1); /* important for callers */
return res;
}
/* Count actually used entry part entries (non-NULL keys). */
DUK_LOCAL duk_uint32_t duk__count_used_e_keys(duk_hthread *thr, duk_hobject *obj) {
duk_uint_fast32_t i;
duk_uint_fast32_t n = 0;
duk_hstring **e;
DUK_ASSERT(obj != NULL);
DUK_UNREF(thr);
e = DUK_HOBJECT_E_GET_KEY_BASE(thr->heap, obj);
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
if (*e++) {
n++;
}
}
return (duk_uint32_t) n;
}
/* Count actually used array part entries and array minimum size.
* NOTE: 'out_min_size' can be computed much faster by starting from the
* end and breaking out early when finding first used entry, but this is
* not needed now.
*/
DUK_LOCAL void duk__compute_a_stats(duk_hthread *thr, duk_hobject *obj, duk_uint32_t *out_used, duk_uint32_t *out_min_size) {
duk_uint_fast32_t i;
duk_uint_fast32_t used = 0;
duk_uint_fast32_t highest_idx = (duk_uint_fast32_t) -1; /* see below */
duk_tval *a;
DUK_ASSERT(obj != NULL);
DUK_ASSERT(out_used != NULL);
DUK_ASSERT(out_min_size != NULL);
DUK_UNREF(thr);
a = DUK_HOBJECT_A_GET_BASE(thr->heap, obj);
for (i = 0; i < DUK_HOBJECT_GET_ASIZE(obj); i++) {
duk_tval *tv = a++;
if (!DUK_TVAL_IS_UNUSED(tv)) {
used++;
highest_idx = i;
}
}
/* Initial value for highest_idx is -1 coerced to unsigned. This
* is a bit odd, but (highest_idx + 1) will then wrap to 0 below
* for out_min_size as intended.
*/
*out_used = (duk_uint32_t) used;
*out_min_size = (duk_uint32_t) (highest_idx + 1); /* 0 if no used entries */
}
/* Check array density and indicate whether or not the array part should be abandoned. */
DUK_LOCAL duk_bool_t duk__abandon_array_density_check(duk_uint32_t a_used, duk_uint32_t a_size) {
/*
* Array abandon check; abandon if:
*
* new_used / new_size < limit
* new_used < limit * new_size || limit is 3 bits fixed point
* new_used < limit' / 8 * new_size || *8
* 8*new_used < limit' * new_size || :8
* new_used < limit' * (new_size / 8)
*
* Here, new_used = a_used, new_size = a_size.
*
* Note: some callers use approximate values for a_used and/or a_size
* (e.g. dropping a '+1' term). This doesn't affect the usefulness
* of the check, but may confuse debugging.
*/
return (a_used < DUK_USE_HOBJECT_ARRAY_ABANDON_LIMIT * (a_size >> 3));
}
/* Fast check for extending array: check whether or not a slow density check is required. */
DUK_LOCAL duk_bool_t duk__abandon_array_slow_check_required(duk_uint32_t arr_idx, duk_uint32_t old_size) {
duk_uint32_t new_size_min;
/*
* In a fast check we assume old_size equals old_used (i.e., existing
* array is fully dense).
*
* Slow check if:
*
* (new_size - old_size) / old_size > limit
* new_size - old_size > limit * old_size
* new_size > (1 + limit) * old_size || limit' is 3 bits fixed point
* new_size > (1 + (limit' / 8)) * old_size || * 8
* 8 * new_size > (8 + limit') * old_size || : 8
* new_size > (8 + limit') * (old_size / 8)
* new_size > limit'' * (old_size / 8) || limit'' = 9 -> max 25% increase
* arr_idx + 1 > limit'' * (old_size / 8)
*
* This check doesn't work well for small values, so old_size is rounded
* up for the check (and the '+ 1' of arr_idx can be ignored in practice):
*
* arr_idx > limit'' * ((old_size + 7) / 8)
*/
new_size_min = arr_idx + 1;
return (new_size_min >= DUK_USE_HOBJECT_ARRAY_ABANDON_MINSIZE) &&
(arr_idx > DUK_USE_HOBJECT_ARRAY_FAST_RESIZE_LIMIT * ((old_size + 7) >> 3));
}
DUK_LOCAL duk_bool_t duk__abandon_array_check(duk_hthread *thr, duk_uint32_t arr_idx, duk_hobject *obj) {
duk_uint32_t min_size;
duk_uint32_t old_used;
duk_uint32_t old_size;
if (!duk__abandon_array_slow_check_required(arr_idx, DUK_HOBJECT_GET_ASIZE(obj))) {
DUK_DDD(DUK_DDDPRINT("=> fast resize is OK"));
return 0;
}
duk__compute_a_stats(thr, obj, &old_used, &old_size);
DUK_DDD(DUK_DDDPRINT("abandon check, array stats: old_used=%ld, old_size=%ld, arr_idx=%ld",
(long) old_used, (long) old_size, (long) arr_idx));
min_size = arr_idx + 1;
#if defined(DUK_USE_OBJSIZES16)
if (min_size > DUK_UINT16_MAX) {
goto do_abandon;
}
#endif
DUK_UNREF(min_size);
/* Note: intentionally use approximations to shave a few instructions:
* a_used = old_used (accurate: old_used + 1)
* a_size = arr_idx (accurate: arr_idx + 1)
*/
if (duk__abandon_array_density_check(old_used, arr_idx)) {
DUK_DD(DUK_DDPRINT("write to new array entry beyond current length, "
"decided to abandon array part (would become too sparse)"));
/* Abandoning requires a props allocation resize and
* 'rechecks' the valstack, invalidating any existing
* valstack value pointers.
*/
goto do_abandon;
}
DUK_DDD(DUK_DDDPRINT("=> decided to keep array part"));
return 0;
do_abandon:
duk__abandon_array_part(thr, obj);
DUK_ASSERT(!DUK_HOBJECT_HAS_ARRAY_PART(obj));
return 1;
}
DUK_LOCAL duk_tval *duk__obtain_arridx_slot_slowpath(duk_hthread *thr, duk_uint32_t arr_idx, duk_hobject *obj) {
/*
* Array needs to grow, but we don't want it becoming too sparse.
* If it were to become sparse, abandon array part, moving all
* array entries into the entries part (for good).
*
* Since we don't keep track of actual density (used vs. size) of
* the array part, we need to estimate somehow. The check is made
* in two parts:
*
* - Check whether the resize need is small compared to the
* current size (relatively); if so, resize without further
* checking (essentially we assume that the original part is
* "dense" so that the result would be dense enough).
*
* - Otherwise, compute the resize using an actual density
* measurement based on counting the used array entries.
*/
DUK_DDD(DUK_DDDPRINT("write to new array requires array resize, decide whether to do a "
"fast resize without abandon check (arr_idx=%ld, old_size=%ld)",
(long) arr_idx, (long) DUK_HOBJECT_GET_ASIZE(obj)));
if (DUK_UNLIKELY(duk__abandon_array_check(thr, arr_idx, obj) != 0)) {
DUK_ASSERT(!DUK_HOBJECT_HAS_ARRAY_PART(obj));
return NULL;
}
DUK_DD(DUK_DDPRINT("write to new array entry beyond current length, "
"decided to extend current allocation"));
/* In principle it's possible to run out of memory extending the
* array but with the allocation going through if we were to abandon
* the array part and try again. In practice this should be rare
* because abandoned arrays have a higher per-entry footprint.
*/
duk__grow_props_for_array_item(thr, obj, arr_idx);
DUK_ASSERT(DUK_HOBJECT_HAS_ARRAY_PART(obj));
DUK_ASSERT(arr_idx < DUK_HOBJECT_GET_ASIZE(obj));
return DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, arr_idx);
}
DUK_LOCAL DUK_INLINE duk_tval *duk__obtain_arridx_slot(duk_hthread *thr, duk_uint32_t arr_idx, duk_hobject *obj) {
if (DUK_LIKELY(arr_idx < DUK_HOBJECT_GET_ASIZE(obj))) {
return DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, arr_idx);
} else {
return duk__obtain_arridx_slot_slowpath(thr, arr_idx, obj);
}
}
/*
* Proxy helpers
*/
#if defined(DUK_USE_ES6_PROXY)
DUK_INTERNAL duk_bool_t duk_hobject_proxy_check(duk_hobject *obj, duk_hobject **out_target, duk_hobject **out_handler) {
duk_hproxy *h_proxy;
DUK_ASSERT(obj != NULL);
DUK_ASSERT(out_target != NULL);
DUK_ASSERT(out_handler != NULL);
/* Caller doesn't need to check exotic proxy behavior (but does so for
* some fast paths).
*/
if (DUK_LIKELY(!DUK_HOBJECT_IS_PROXY(obj))) {
return 0;
}
h_proxy = (duk_hproxy *) obj;
DUK_HPROXY_ASSERT_VALID(h_proxy);
DUK_ASSERT(h_proxy->handler != NULL);
DUK_ASSERT(h_proxy->target != NULL);
*out_handler = h_proxy->handler;
*out_target = h_proxy->target;
return 1;
}
#endif /* DUK_USE_ES6_PROXY */
/* Get Proxy target object. If the argument is not a Proxy, return it as is.
* If a Proxy is revoked, an error is thrown.
*/
#if defined(DUK_USE_ES6_PROXY)
DUK_INTERNAL duk_hobject *duk_hobject_resolve_proxy_target(duk_hobject *obj) {
DUK_ASSERT(obj != NULL);
/* Resolve Proxy targets until Proxy chain ends. No explicit check for
* a Proxy loop: user code cannot create such a loop (it would only be
* possible by editing duk_hproxy references directly).
*/
while (DUK_HOBJECT_IS_PROXY(obj)) {
duk_hproxy *h_proxy;
h_proxy = (duk_hproxy *) obj;
DUK_HPROXY_ASSERT_VALID(h_proxy);
obj = h_proxy->target;
DUK_ASSERT(obj != NULL);
}
DUK_ASSERT(obj != NULL);
return obj;
}
#endif /* DUK_USE_ES6_PROXY */
#if defined(DUK_USE_ES6_PROXY)
DUK_LOCAL duk_bool_t duk__proxy_check_prop(duk_hthread *thr, duk_hobject *obj, duk_small_uint_t stridx_trap, duk_tval *tv_key, duk_hobject **out_target) {
duk_hobject *h_handler;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(tv_key != NULL);
DUK_ASSERT(out_target != NULL);
if (!duk_hobject_proxy_check(obj, out_target, &h_handler)) {
return 0;
}
DUK_ASSERT(*out_target != NULL);
DUK_ASSERT(h_handler != NULL);
/* XXX: At the moment Duktape accesses internal keys like _Finalizer using a
* normal property set/get which would allow a proxy handler to interfere with
* such behavior and to get access to internal key strings. This is not a problem
* as such because internal key strings can be created in other ways too (e.g.
* through buffers). The best fix is to change Duktape internal lookups to
* skip proxy behavior. Until that, internal property accesses bypass the
* proxy and are applied to the target (as if the handler did not exist).
* This has some side effects, see test-bi-proxy-internal-keys.js.
*/
if (DUK_TVAL_IS_STRING(tv_key)) {
duk_hstring *h_key = (duk_hstring *) DUK_TVAL_GET_STRING(tv_key);
DUK_ASSERT(h_key != NULL);
if (DUK_HSTRING_HAS_HIDDEN(h_key)) {
/* Symbol accesses must go through proxy lookup in ES2015.
* Hidden symbols behave like Duktape 1.x internal keys
* and currently won't.
*/
DUK_DDD(DUK_DDDPRINT("hidden key, skip proxy handler and apply to target"));
return 0;
}
}
/* The handler is looked up with a normal property lookup; it may be an
* accessor or the handler object itself may be a proxy object. If the
* handler is a proxy, we need to extend the valstack as we make a
* recursive proxy check without a function call in between (in fact
* there is no limit to the potential recursion here).
*
* (For sanity, proxy creation rejects another proxy object as either
* the handler or the target at the moment so recursive proxy cases
* are not realized now.)
*/
/* XXX: C recursion limit if proxies are allowed as handler/target values */
duk_require_stack(thr, DUK__VALSTACK_PROXY_LOOKUP);
duk_push_hobject(thr, h_handler);
if (duk_get_prop_stridx_short(thr, -1, stridx_trap)) {
/* -> [ ... handler trap ] */
duk_insert(thr, -2); /* -> [ ... trap handler ] */
/* stack prepped for func call: [ ... trap handler ] */
return 1;
} else {
duk_pop_2_unsafe(thr);
return 0;
}
}
#endif /* DUK_USE_ES6_PROXY */
/*
* Reallocate property allocation, moving properties to the new allocation.
*
* Includes key compaction, rehashing, and can also optionally abandon
* the array part, 'migrating' array entries into the beginning of the
* new entry part.
*
* There is no support for in-place reallocation or just compacting keys
* without resizing the property allocation. This is intentional to keep
* code size minimal, but would be useful future work.
*
* The implementation is relatively straightforward, except for the array
* abandonment process. Array abandonment requires that new string keys
* are interned, which may trigger GC. All keys interned so far must be
* reachable for GC at all times and correctly refcounted for; valstack is
* used for that now.
*
* Also, a GC triggered during this reallocation process must not interfere
* with the object being resized. This is currently controlled by preventing
* finalizers (as they may affect ANY object) and object compaction in
* mark-and-sweep. It would suffice to protect only this particular object
* from compaction, however. DECREF refzero cascades are side effect free
* and OK.
*
* Note: because we need to potentially resize the valstack (as part
* of abandoning the array part), any tval pointers to the valstack
* will become invalid after this call.
*/
DUK_INTERNAL void duk_hobject_realloc_props(duk_hthread *thr,
duk_hobject *obj,
duk_uint32_t new_e_size,
duk_uint32_t new_a_size,
duk_uint32_t new_h_size,
duk_bool_t abandon_array) {
duk_small_uint_t prev_ms_base_flags;
duk_uint32_t new_alloc_size;
duk_uint32_t new_e_size_adjusted;
duk_uint8_t *new_p;
duk_hstring **new_e_k;
duk_propvalue *new_e_pv;
duk_uint8_t *new_e_f;
duk_tval *new_a;
duk_uint32_t *new_h;
duk_uint32_t new_e_next;
duk_uint_fast32_t i;
duk_size_t array_copy_size;
#if defined(DUK_USE_ASSERTIONS)
duk_bool_t prev_error_not_allowed;
#endif
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(!abandon_array || new_a_size == 0); /* if abandon_array, new_a_size must be 0 */
DUK_ASSERT(DUK_HOBJECT_GET_PROPS(thr->heap, obj) != NULL || (DUK_HOBJECT_GET_ESIZE(obj) == 0 && DUK_HOBJECT_GET_ASIZE(obj) == 0));
DUK_ASSERT(new_h_size == 0 || new_h_size >= new_e_size); /* required to guarantee success of rehashing,
* intentionally use unadjusted new_e_size
*/
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj));
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_STATS_INC(thr->heap, stats_object_realloc_props);
/*
* Pre resize assertions.
*/
#if defined(DUK_USE_ASSERTIONS)
/* XXX: pre-checks (such as no duplicate keys) */
#endif
/*
* For property layout 1, tweak e_size to ensure that the whole entry
* part (key + val + flags) is a suitable multiple for alignment
* (platform specific).
*
* Property layout 2 does not require this tweaking and is preferred
* on low RAM platforms requiring alignment.
*/
#if defined(DUK_USE_HOBJECT_LAYOUT_2) || defined(DUK_USE_HOBJECT_LAYOUT_3)
DUK_DDD(DUK_DDDPRINT("using layout 2 or 3, no need to pad e_size: %ld", (long) new_e_size));
new_e_size_adjusted = new_e_size;
#elif defined(DUK_USE_HOBJECT_LAYOUT_1) && (DUK_HOBJECT_ALIGN_TARGET == 1)
DUK_DDD(DUK_DDDPRINT("using layout 1, but no need to pad e_size: %ld", (long) new_e_size));
new_e_size_adjusted = new_e_size;
#elif defined(DUK_USE_HOBJECT_LAYOUT_1) && ((DUK_HOBJECT_ALIGN_TARGET == 4) || (DUK_HOBJECT_ALIGN_TARGET == 8))
new_e_size_adjusted = (new_e_size + (duk_uint32_t) DUK_HOBJECT_ALIGN_TARGET - 1U) &
(~((duk_uint32_t) DUK_HOBJECT_ALIGN_TARGET - 1U));
DUK_DDD(DUK_DDDPRINT("using layout 1, and alignment target is %ld, adjusted e_size: %ld -> %ld",
(long) DUK_HOBJECT_ALIGN_TARGET, (long) new_e_size, (long) new_e_size_adjusted));
DUK_ASSERT(new_e_size_adjusted >= new_e_size);
#else
#error invalid hobject layout defines
#endif
/*
* Debug logging after adjustment.
*/
DUK_DDD(DUK_DDDPRINT("attempt to resize hobject %p props (%ld -> %ld bytes), from {p=%p,e_size=%ld,e_next=%ld,a_size=%ld,h_size=%ld} to "
"{e_size=%ld,a_size=%ld,h_size=%ld}, abandon_array=%ld, unadjusted new_e_size=%ld",
(void *) obj,
(long) DUK_HOBJECT_P_COMPUTE_SIZE(DUK_HOBJECT_GET_ESIZE(obj),
DUK_HOBJECT_GET_ASIZE(obj),
DUK_HOBJECT_GET_HSIZE(obj)),
(long) DUK_HOBJECT_P_COMPUTE_SIZE(new_e_size_adjusted, new_a_size, new_h_size),
(void *) DUK_HOBJECT_GET_PROPS(thr->heap, obj),
(long) DUK_HOBJECT_GET_ESIZE(obj),
(long) DUK_HOBJECT_GET_ENEXT(obj),
(long) DUK_HOBJECT_GET_ASIZE(obj),
(long) DUK_HOBJECT_GET_HSIZE(obj),
(long) new_e_size_adjusted,
(long) new_a_size,
(long) new_h_size,
(long) abandon_array,
(long) new_e_size));
/*
* Property count check. This is the only point where we ensure that
* we don't get more (allocated) property space that we can handle.
* There aren't hard limits as such, but some algorithms may fail
* if we get too close to the 4G property limit.
*
* Since this works based on allocation size (not actually used size),
* the limit is a bit approximate but good enough in practice.
*/
if (new_e_size_adjusted + new_a_size > DUK_HOBJECT_MAX_PROPERTIES) {
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return;);
}
#if defined(DUK_USE_OBJSIZES16)
if (new_e_size_adjusted > DUK_UINT16_MAX || new_a_size > DUK_UINT16_MAX) {
/* If caller gave us sizes larger than what we can store,
* fail memory safely with an internal error rather than
* truncating the sizes.
*/
DUK_ERROR_INTERNAL(thr);
DUK_WO_NORETURN(return;);
}
#endif
/*
* Compute new alloc size and alloc new area.
*
* The new area is not tracked in the heap at all, so it's critical
* we get to free/keep it in a controlled manner.
*/
#if defined(DUK_USE_ASSERTIONS)
/* Whole path must be error throw free, but we may be called from
* within error handling so can't assert for error_not_allowed == 0.
*/
prev_error_not_allowed = thr->heap->error_not_allowed;
thr->heap->error_not_allowed = 1;
#endif
prev_ms_base_flags = thr->heap->ms_base_flags;
thr->heap->ms_base_flags |=
DUK_MS_FLAG_NO_OBJECT_COMPACTION; /* Avoid attempt to compact the current object (all objects really). */
thr->heap->pf_prevent_count++; /* Avoid finalizers. */
DUK_ASSERT(thr->heap->pf_prevent_count != 0); /* Wrap. */
new_alloc_size = DUK_HOBJECT_P_COMPUTE_SIZE(new_e_size_adjusted, new_a_size, new_h_size);
DUK_DDD(DUK_DDDPRINT("new hobject allocation size is %ld", (long) new_alloc_size));
if (new_alloc_size == 0) {
DUK_ASSERT(new_e_size_adjusted == 0);
DUK_ASSERT(new_a_size == 0);
DUK_ASSERT(new_h_size == 0);
new_p = NULL;
} else {
/* Alloc may trigger mark-and-sweep but no compaction, and
* cannot throw.
*/
#if 0 /* XXX: inject test */
if (1) {
new_p = NULL;
goto alloc_failed;
}
#endif
new_p = (duk_uint8_t *) DUK_ALLOC(thr->heap, new_alloc_size);
if (new_p == NULL) {
/* NULL always indicates alloc failure because
* new_alloc_size > 0.
*/
goto alloc_failed;
}
}
/* Set up pointers to the new property area: this is hidden behind a macro
* because it is memory layout specific.
*/
DUK_HOBJECT_P_SET_REALLOC_PTRS(new_p, new_e_k, new_e_pv, new_e_f, new_a, new_h,
new_e_size_adjusted, new_a_size, new_h_size);
DUK_UNREF(new_h); /* happens when hash part dropped */
new_e_next = 0;
/* if new_p == NULL, all of these pointers are NULL */
DUK_ASSERT((new_p != NULL) ||
(new_e_k == NULL && new_e_pv == NULL && new_e_f == NULL &&
new_a == NULL && new_h == NULL));
DUK_DDD(DUK_DDDPRINT("new alloc size %ld, new_e_k=%p, new_e_pv=%p, new_e_f=%p, new_a=%p, new_h=%p",
(long) new_alloc_size, (void *) new_e_k, (void *) new_e_pv, (void *) new_e_f,
(void *) new_a, (void *) new_h));
/*
* Migrate array part to start of entries if requested.
*
* Note: from an enumeration perspective the order of entry keys matters.
* Array keys should appear wherever they appeared before the array abandon
* operation. (This no longer matters much because keys are ES2015 sorted.)
*/
if (abandon_array) {
/* Assuming new_a_size == 0, and that entry part contains
* no conflicting keys, refcounts do not need to be adjusted for
* the values, as they remain exactly the same.
*
* The keys, however, need to be interned, incref'd, and be
* reachable for GC. Any intern attempt may trigger a GC and
* claim any non-reachable strings, so every key must be reachable
* at all times. Refcounts must be correct to satisfy refcount
* assertions.
*
* A longjmp must not occur here, as the new_p allocation would
* leak. Refcounts would come out correctly as the interned
* strings are valstack tracked.
*/
DUK_ASSERT(new_a_size == 0);
DUK_STATS_INC(thr->heap, stats_object_abandon_array);
for (i = 0; i < DUK_HOBJECT_GET_ASIZE(obj); i++) {
duk_tval *tv1;
duk_tval *tv2;
duk_hstring *key;
DUK_ASSERT(DUK_HOBJECT_GET_PROPS(thr->heap, obj) != NULL);
tv1 = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, i);
if (DUK_TVAL_IS_UNUSED(tv1)) {
continue;
}
DUK_ASSERT(new_p != NULL && new_e_k != NULL &&
new_e_pv != NULL && new_e_f != NULL);
/*
* Intern key via the valstack to ensure reachability behaves
* properly. We must avoid longjmp's here so use non-checked
* primitives.
*
* Note: duk_check_stack() potentially reallocs the valstack,
* invalidating any duk_tval pointers to valstack. Callers
* must be careful.
*/
#if 0 /* XXX: inject test */
if (1) {
goto abandon_error;
}
#endif
/* Never shrinks; auto-adds DUK_VALSTACK_INTERNAL_EXTRA, which
* is generous.
*/
if (!duk_check_stack(thr, 1)) {
goto abandon_error;
}
DUK_ASSERT_VALSTACK_SPACE(thr, 1);
key = duk_heap_strtable_intern_u32(thr->heap, (duk_uint32_t) i);
if (key == NULL) {
goto abandon_error;
}
duk_push_hstring(thr, key); /* keep key reachable for GC etc; guaranteed not to fail */
/* Key is now reachable in the valstack, don't INCREF
* the new allocation yet (we'll steal the refcounts
* from the value stack once all keys are done).
*/
new_e_k[new_e_next] = key;
tv2 = &new_e_pv[new_e_next].v; /* array entries are all plain values */
DUK_TVAL_SET_TVAL(tv2, tv1);
new_e_f[new_e_next] = DUK_PROPDESC_FLAG_WRITABLE |
DUK_PROPDESC_FLAG_ENUMERABLE |
DUK_PROPDESC_FLAG_CONFIGURABLE;
new_e_next++;
/* Note: new_e_next matches pushed temp key count, and nothing can
* fail above between the push and this point.
*/
}
/* Steal refcounts from value stack. */
DUK_DDD(DUK_DDDPRINT("abandon array: pop %ld key temps from valstack", (long) new_e_next));
duk_pop_n_nodecref_unsafe(thr, (duk_idx_t) new_e_next);
}
/*
* Copy keys and values in the entry part (compacting them at the same time).
*/
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
duk_hstring *key;
DUK_ASSERT(DUK_HOBJECT_GET_PROPS(thr->heap, obj) != NULL);
key = DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i);
if (key == NULL) {
continue;
}
DUK_ASSERT(new_p != NULL && new_e_k != NULL &&
new_e_pv != NULL && new_e_f != NULL);
new_e_k[new_e_next] = key;
new_e_pv[new_e_next] = DUK_HOBJECT_E_GET_VALUE(thr->heap, obj, i);
new_e_f[new_e_next] = DUK_HOBJECT_E_GET_FLAGS(thr->heap, obj, i);
new_e_next++;
}
/* the entries [new_e_next, new_e_size_adjusted[ are left uninitialized on purpose (ok, not gc reachable) */
/*
* Copy array elements to new array part. If the new array part is
* larger, initialize the unused entries as UNUSED because they are
* GC reachable.
*/
#if defined(DUK_USE_ASSERTIONS)
/* Caller must have decref'd values above new_a_size (if that is necessary). */
if (!abandon_array) {
for (i = new_a_size; i < DUK_HOBJECT_GET_ASIZE(obj); i++) {
duk_tval *tv;
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, i);
DUK_ASSERT(DUK_TVAL_IS_UNUSED(tv));
}
}
#endif
if (new_a_size > DUK_HOBJECT_GET_ASIZE(obj)) {
array_copy_size = sizeof(duk_tval) * DUK_HOBJECT_GET_ASIZE(obj);
} else {
array_copy_size = sizeof(duk_tval) * new_a_size;
}
DUK_ASSERT(new_a != NULL || array_copy_size == 0U);
DUK_ASSERT(DUK_HOBJECT_GET_PROPS(thr->heap, obj) != NULL || array_copy_size == 0U);
DUK_ASSERT(DUK_HOBJECT_GET_ASIZE(obj) > 0 || array_copy_size == 0U);
duk_memcpy_unsafe((void *) new_a,
(const void *) DUK_HOBJECT_A_GET_BASE(thr->heap, obj),
array_copy_size);
for (i = DUK_HOBJECT_GET_ASIZE(obj); i < new_a_size; i++) {
duk_tval *tv = &new_a[i];
DUK_TVAL_SET_UNUSED(tv);
}
/*
* Rebuild the hash part always from scratch (guaranteed to finish
* as long as caller gave consistent parameters).
*
* Any resize of hash part requires rehashing. In addition, by rehashing
* get rid of any elements marked deleted (DUK__HASH_DELETED) which is critical
* to ensuring the hash part never fills up.
*/
#if defined(DUK_USE_HOBJECT_HASH_PART)
if (new_h_size == 0) {
DUK_DDD(DUK_DDDPRINT("no hash part, no rehash"));
} else {
duk_uint32_t mask;
DUK_ASSERT(new_h != NULL);
/* fill new_h with u32 0xff = UNUSED */
DUK_ASSERT(new_h_size > 0);
duk_memset(new_h, 0xff, sizeof(duk_uint32_t) * new_h_size);
DUK_ASSERT(new_e_next <= new_h_size); /* equality not actually possible */
mask = new_h_size - 1;
for (i = 0; i < new_e_next; i++) {
duk_hstring *key = new_e_k[i];
duk_uint32_t j, step;
DUK_ASSERT(key != NULL);
j = DUK_HSTRING_GET_HASH(key) & mask;
step = 1; /* Cache friendly but clustering prone. */
for (;;) {
DUK_ASSERT(new_h[j] != DUK__HASH_DELETED); /* should never happen */
if (new_h[j] == DUK__HASH_UNUSED) {
DUK_DDD(DUK_DDDPRINT("rebuild hit %ld -> %ld", (long) j, (long) i));
new_h[j] = (duk_uint32_t) i;
break;
}
DUK_DDD(DUK_DDDPRINT("rebuild miss %ld, step %ld", (long) j, (long) step));
j = (j + step) & mask;
/* Guaranteed to finish (hash is larger than #props). */
}
}
}
#endif /* DUK_USE_HOBJECT_HASH_PART */
/*
* Nice debug log.
*/
DUK_DD(DUK_DDPRINT("resized hobject %p props (%ld -> %ld bytes), from {p=%p,e_size=%ld,e_next=%ld,a_size=%ld,h_size=%ld} to "
"{p=%p,e_size=%ld,e_next=%ld,a_size=%ld,h_size=%ld}, abandon_array=%ld, unadjusted new_e_size=%ld",
(void *) obj,
(long) DUK_HOBJECT_P_COMPUTE_SIZE(DUK_HOBJECT_GET_ESIZE(obj),
DUK_HOBJECT_GET_ASIZE(obj),
DUK_HOBJECT_GET_HSIZE(obj)),
(long) new_alloc_size,
(void *) DUK_HOBJECT_GET_PROPS(thr->heap, obj),
(long) DUK_HOBJECT_GET_ESIZE(obj),
(long) DUK_HOBJECT_GET_ENEXT(obj),
(long) DUK_HOBJECT_GET_ASIZE(obj),
(long) DUK_HOBJECT_GET_HSIZE(obj),
(void *) new_p,
(long) new_e_size_adjusted,
(long) new_e_next,
(long) new_a_size,
(long) new_h_size,
(long) abandon_array,
(long) new_e_size));
/*
* All done, switch properties ('p') allocation to new one.
*/
DUK_FREE_CHECKED(thr, DUK_HOBJECT_GET_PROPS(thr->heap, obj)); /* NULL obj->p is OK */
DUK_HOBJECT_SET_PROPS(thr->heap, obj, new_p);
DUK_HOBJECT_SET_ESIZE(obj, new_e_size_adjusted);
DUK_HOBJECT_SET_ENEXT(obj, new_e_next);
DUK_HOBJECT_SET_ASIZE(obj, new_a_size);
DUK_HOBJECT_SET_HSIZE(obj, new_h_size);
/* Clear array part flag only after switching. */
if (abandon_array) {
DUK_HOBJECT_CLEAR_ARRAY_PART(obj);
}
DUK_DDD(DUK_DDDPRINT("resize result: %!O", (duk_heaphdr *) obj));
DUK_ASSERT(thr->heap->pf_prevent_count > 0);
thr->heap->pf_prevent_count--;
thr->heap->ms_base_flags = prev_ms_base_flags;
#if defined(DUK_USE_ASSERTIONS)
DUK_ASSERT(thr->heap->error_not_allowed == 1);
thr->heap->error_not_allowed = prev_error_not_allowed;
#endif
/*
* Post resize assertions.
*/
#if defined(DUK_USE_ASSERTIONS)
/* XXX: post-checks (such as no duplicate keys) */
#endif
return;
/*
* Abandon array failed. We don't need to DECREF anything
* because the references in the new allocation are not
* INCREF'd until abandon is complete. The string interned
* keys are on the value stack and are handled normally by
* unwind.
*/
abandon_error:
alloc_failed:
DUK_D(DUK_DPRINT("object property table resize failed"));
DUK_FREE_CHECKED(thr, new_p); /* OK for NULL. */
thr->heap->pf_prevent_count--;
thr->heap->ms_base_flags = prev_ms_base_flags;
#if defined(DUK_USE_ASSERTIONS)
DUK_ASSERT(thr->heap->error_not_allowed == 1);
thr->heap->error_not_allowed = prev_error_not_allowed;
#endif
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return;);
}
/*
* Helpers to resize properties allocation on specific needs.
*/
DUK_INTERNAL void duk_hobject_resize_entrypart(duk_hthread *thr,
duk_hobject *obj,
duk_uint32_t new_e_size) {
duk_uint32_t old_e_size;
duk_uint32_t new_a_size;
duk_uint32_t new_h_size;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
old_e_size = DUK_HOBJECT_GET_ESIZE(obj);
if (old_e_size > new_e_size) {
new_e_size = old_e_size;
}
#if defined(DUK_USE_HOBJECT_HASH_PART)
new_h_size = duk__get_default_h_size(new_e_size);
#else
new_h_size = 0;
#endif
new_a_size = DUK_HOBJECT_GET_ASIZE(obj);
duk_hobject_realloc_props(thr, obj, new_e_size, new_a_size, new_h_size, 0);
}
/* Grow entry part allocation for one additional entry. */
DUK_LOCAL void duk__grow_props_for_new_entry_item(duk_hthread *thr, duk_hobject *obj) {
duk_uint32_t old_e_used; /* actually used, non-NULL entries */
duk_uint32_t new_e_size_minimum;
duk_uint32_t new_e_size;
duk_uint32_t new_a_size;
duk_uint32_t new_h_size;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
/* Duktape 0.11.0 and prior tried to optimize the resize by not
* counting the number of actually used keys prior to the resize.
* This worked mostly well but also caused weird leak-like behavior
* as in: test-bug-object-prop-alloc-unbounded.js. So, now we count
* the keys explicitly to compute the new entry part size.
*/
old_e_used = duk__count_used_e_keys(thr, obj);
new_e_size_minimum = old_e_used + 1;
new_e_size = old_e_used + duk__get_min_grow_e(old_e_used);
#if defined(DUK_USE_HOBJECT_HASH_PART)
new_h_size = duk__get_default_h_size(new_e_size);
#else
new_h_size = 0;
#endif
new_a_size = DUK_HOBJECT_GET_ASIZE(obj);
#if defined(DUK_USE_OBJSIZES16)
if (new_e_size > DUK_UINT16_MAX) {
new_e_size = DUK_UINT16_MAX;
}
if (new_h_size > DUK_UINT16_MAX) {
new_h_size = DUK_UINT16_MAX;
}
if (new_a_size > DUK_UINT16_MAX) {
new_a_size = DUK_UINT16_MAX;
}
#endif
DUK_ASSERT(new_h_size == 0 || new_h_size >= new_e_size);
if (!(new_e_size >= new_e_size_minimum)) {
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return;);
}
duk_hobject_realloc_props(thr, obj, new_e_size, new_a_size, new_h_size, 0);
}
/* Grow array part for a new highest array index. */
DUK_LOCAL void duk__grow_props_for_array_item(duk_hthread *thr, duk_hobject *obj, duk_uint32_t highest_arr_idx) {
duk_uint32_t new_e_size;
duk_uint32_t new_a_size;
duk_uint32_t new_a_size_minimum;
duk_uint32_t new_h_size;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(highest_arr_idx >= DUK_HOBJECT_GET_ASIZE(obj));
new_e_size = DUK_HOBJECT_GET_ESIZE(obj);
new_h_size = DUK_HOBJECT_GET_HSIZE(obj);
new_a_size_minimum = highest_arr_idx + 1;
new_a_size = highest_arr_idx + duk__get_min_grow_a(highest_arr_idx);
DUK_ASSERT(new_a_size >= highest_arr_idx + 1); /* duk__get_min_grow_a() is always >= 1 */
#if defined(DUK_USE_OBJSIZES16)
if (new_e_size > DUK_UINT16_MAX) {
new_e_size = DUK_UINT16_MAX;
}
if (new_h_size > DUK_UINT16_MAX) {
new_h_size = DUK_UINT16_MAX;
}
if (new_a_size > DUK_UINT16_MAX) {
new_a_size = DUK_UINT16_MAX;
}
#endif
if (!(new_a_size >= new_a_size_minimum)) {
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return;);
}
duk_hobject_realloc_props(thr, obj, new_e_size, new_a_size, new_h_size, 0);
}
/* Abandon array part, moving array entries into entries part.
* This requires a props resize, which is a heavy operation.
* We also compact the entries part while we're at it, although
* this is not strictly required.
*/
DUK_LOCAL void duk__abandon_array_part(duk_hthread *thr, duk_hobject *obj) {
duk_uint32_t new_e_size_minimum;
duk_uint32_t new_e_size;
duk_uint32_t new_a_size;
duk_uint32_t new_h_size;
duk_uint32_t e_used; /* actually used, non-NULL keys */
duk_uint32_t a_used;
duk_uint32_t a_size;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
e_used = duk__count_used_e_keys(thr, obj);
duk__compute_a_stats(thr, obj, &a_used, &a_size);
/*
* Must guarantee all actually used array entries will fit into
* new entry part. Add one growth step to ensure we don't run out
* of space right away.
*/
new_e_size_minimum = e_used + a_used;
new_e_size = new_e_size_minimum + duk__get_min_grow_e(new_e_size_minimum);
new_a_size = 0;
#if defined(DUK_USE_HOBJECT_HASH_PART)
new_h_size = duk__get_default_h_size(new_e_size);
#else
new_h_size = 0;
#endif
#if defined(DUK_USE_OBJSIZES16)
if (new_e_size > DUK_UINT16_MAX) {
new_e_size = DUK_UINT16_MAX;
}
if (new_h_size > DUK_UINT16_MAX) {
new_h_size = DUK_UINT16_MAX;
}
if (new_a_size > DUK_UINT16_MAX) {
new_a_size = DUK_UINT16_MAX;
}
#endif
if (!(new_e_size >= new_e_size_minimum)) {
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return;);
}
DUK_DD(DUK_DDPRINT("abandon array part for hobject %p, "
"array stats before: e_used=%ld, a_used=%ld, a_size=%ld; "
"resize to e_size=%ld, a_size=%ld, h_size=%ld",
(void *) obj, (long) e_used, (long) a_used, (long) a_size,
(long) new_e_size, (long) new_a_size, (long) new_h_size));
duk_hobject_realloc_props(thr, obj, new_e_size, new_a_size, new_h_size, 1);
}
/*
* Compact an object. Minimizes allocation size for objects which are
* not likely to be extended. This is useful for internal and non-
* extensible objects, but can also be called for non-extensible objects.
* May abandon the array part if it is computed to be too sparse.
*
* This call is relatively expensive, as it needs to scan both the
* entries and the array part.
*
* The call may fail due to allocation error.
*/
DUK_INTERNAL void duk_hobject_compact_props(duk_hthread *thr, duk_hobject *obj) {
duk_uint32_t e_size; /* currently used -> new size */
duk_uint32_t a_size; /* currently required */
duk_uint32_t a_used; /* actually used */
duk_uint32_t h_size;
duk_bool_t abandon_array;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
#if defined(DUK_USE_ROM_OBJECTS)
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)) {
DUK_DD(DUK_DDPRINT("ignore attempt to compact a rom object"));
return;
}
#endif
e_size = duk__count_used_e_keys(thr, obj);
duk__compute_a_stats(thr, obj, &a_used, &a_size);
DUK_DD(DUK_DDPRINT("compacting hobject, used e keys %ld, used a keys %ld, min a size %ld, "
"resized array density would be: %ld/%ld = %lf",
(long) e_size, (long) a_used, (long) a_size,
(long) a_used, (long) a_size,
(double) a_used / (double) a_size));
if (duk__abandon_array_density_check(a_used, a_size)) {
DUK_DD(DUK_DDPRINT("decided to abandon array during compaction, a_used=%ld, a_size=%ld",
(long) a_used, (long) a_size));
abandon_array = 1;
e_size += a_used;
a_size = 0;
} else {
DUK_DD(DUK_DDPRINT("decided to keep array during compaction"));
abandon_array = 0;
}
#if defined(DUK_USE_HOBJECT_HASH_PART)
if (e_size >= DUK_USE_HOBJECT_HASH_PROP_LIMIT) {
h_size = duk__get_default_h_size(e_size);
} else {
h_size = 0;
}
#else
h_size = 0;
#endif
DUK_DD(DUK_DDPRINT("compacting hobject -> new e_size %ld, new a_size=%ld, new h_size=%ld, abandon_array=%ld",
(long) e_size, (long) a_size, (long) h_size, (long) abandon_array));
duk_hobject_realloc_props(thr, obj, e_size, a_size, h_size, abandon_array);
}
/*
* Find an existing key from entry part either by linear scan or by
* using the hash index (if it exists).
*
* Sets entry index (and possibly the hash index) to output variables,
* which allows the caller to update the entry and hash entries in-place.
* If entry is not found, both values are set to -1. If entry is found
* but there is no hash part, h_idx is set to -1.
*/
DUK_INTERNAL duk_bool_t duk_hobject_find_entry(duk_heap *heap, duk_hobject *obj, duk_hstring *key, duk_int_t *e_idx, duk_int_t *h_idx) {
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(e_idx != NULL);
DUK_ASSERT(h_idx != NULL);
DUK_UNREF(heap);
if (DUK_LIKELY(DUK_HOBJECT_GET_HSIZE(obj) == 0))
{
/* Linear scan: more likely because most objects are small.
* This is an important fast path.
*
* XXX: this might be worth inlining for property lookups.
*/
duk_uint_fast32_t i;
duk_uint_fast32_t n;
duk_hstring **h_keys_base;
DUK_DDD(DUK_DDDPRINT("duk_hobject_find_entry() using linear scan for lookup"));
h_keys_base = DUK_HOBJECT_E_GET_KEY_BASE(heap, obj);
n = DUK_HOBJECT_GET_ENEXT(obj);
for (i = 0; i < n; i++) {
if (h_keys_base[i] == key) {
*e_idx = (duk_int_t) i;
*h_idx = -1;
return 1;
}
}
}
#if defined(DUK_USE_HOBJECT_HASH_PART)
else
{
/* hash lookup */
duk_uint32_t n;
duk_uint32_t i, step;
duk_uint32_t *h_base;
duk_uint32_t mask;
DUK_DDD(DUK_DDDPRINT("duk_hobject_find_entry() using hash part for lookup"));
h_base = DUK_HOBJECT_H_GET_BASE(heap, obj);
n = DUK_HOBJECT_GET_HSIZE(obj);
mask = n - 1;
i = DUK_HSTRING_GET_HASH(key) & mask;
step = 1; /* Cache friendly but clustering prone. */
for (;;) {
duk_uint32_t t;
DUK_ASSERT_DISABLE(i >= 0); /* unsigned */
DUK_ASSERT(i < DUK_HOBJECT_GET_HSIZE(obj));
t = h_base[i];
DUK_ASSERT(t == DUK__HASH_UNUSED || t == DUK__HASH_DELETED ||
(t < DUK_HOBJECT_GET_ESIZE(obj))); /* t >= 0 always true, unsigned */
if (t == DUK__HASH_UNUSED) {
break;
} else if (t == DUK__HASH_DELETED) {
DUK_DDD(DUK_DDDPRINT("lookup miss (deleted) i=%ld, t=%ld",
(long) i, (long) t));
} else {
DUK_ASSERT(t < DUK_HOBJECT_GET_ESIZE(obj));
if (DUK_HOBJECT_E_GET_KEY(heap, obj, t) == key) {
DUK_DDD(DUK_DDDPRINT("lookup hit i=%ld, t=%ld -> key %p",
(long) i, (long) t, (void *) key));
*e_idx = (duk_int_t) t;
*h_idx = (duk_int_t) i;
return 1;
}
DUK_DDD(DUK_DDDPRINT("lookup miss i=%ld, t=%ld",
(long) i, (long) t));
}
i = (i + step) & mask;
/* Guaranteed to finish (hash is larger than #props). */
}
}
#endif /* DUK_USE_HOBJECT_HASH_PART */
/* Not found, leave e_idx and h_idx unset. */
return 0;
}
/* For internal use: get non-accessor entry value */
DUK_INTERNAL duk_tval *duk_hobject_find_entry_tval_ptr(duk_heap *heap, duk_hobject *obj, duk_hstring *key) {
duk_int_t e_idx;
duk_int_t h_idx;
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_UNREF(heap);
if (duk_hobject_find_entry(heap, obj, key, &e_idx, &h_idx)) {
DUK_ASSERT(e_idx >= 0);
if (!DUK_HOBJECT_E_SLOT_IS_ACCESSOR(heap, obj, e_idx)) {
return DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(heap, obj, e_idx);
}
}
return NULL;
}
DUK_INTERNAL duk_tval *duk_hobject_find_entry_tval_ptr_stridx(duk_heap *heap, duk_hobject *obj, duk_small_uint_t stridx) {
return duk_hobject_find_entry_tval_ptr(heap, obj, DUK_HEAP_GET_STRING(heap, stridx));
}
/* For internal use: get non-accessor entry value and attributes */
DUK_INTERNAL duk_tval *duk_hobject_find_entry_tval_ptr_and_attrs(duk_heap *heap, duk_hobject *obj, duk_hstring *key, duk_uint_t *out_attrs) {
duk_int_t e_idx;
duk_int_t h_idx;
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(out_attrs != NULL);
DUK_UNREF(heap);
if (duk_hobject_find_entry(heap, obj, key, &e_idx, &h_idx)) {
DUK_ASSERT(e_idx >= 0);
if (!DUK_HOBJECT_E_SLOT_IS_ACCESSOR(heap, obj, e_idx)) {
*out_attrs = DUK_HOBJECT_E_GET_FLAGS(heap, obj, e_idx);
return DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(heap, obj, e_idx);
}
}
/* If not found, out_attrs is left unset. */
return NULL;
}
/* For internal use: get array part value */
DUK_INTERNAL duk_tval *duk_hobject_find_array_entry_tval_ptr(duk_heap *heap, duk_hobject *obj, duk_uarridx_t i) {
duk_tval *tv;
DUK_ASSERT(obj != NULL);
DUK_UNREF(heap);
if (!DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
return NULL;
}
if (i >= DUK_HOBJECT_GET_ASIZE(obj)) {
return NULL;
}
tv = DUK_HOBJECT_A_GET_VALUE_PTR(heap, obj, i);
return tv;
}
/*
* Allocate and initialize a new entry, resizing the properties allocation
* if necessary. Returns entry index (e_idx) or throws an error if alloc fails.
*
* Sets the key of the entry (increasing the key's refcount), and updates
* the hash part if it exists. Caller must set value and flags, and update
* the entry value refcount. A decref for the previous value is not necessary.
*/
DUK_LOCAL duk_int_t duk__hobject_alloc_entry_checked(duk_hthread *thr, duk_hobject *obj, duk_hstring *key) {
duk_uint32_t idx;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(DUK_HOBJECT_GET_ENEXT(obj) <= DUK_HOBJECT_GET_ESIZE(obj));
#if defined(DUK_USE_ASSERTIONS)
/* key must not already exist in entry part */
{
duk_uint_fast32_t i;
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
DUK_ASSERT(DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i) != key);
}
}
#endif
if (DUK_HOBJECT_GET_ENEXT(obj) >= DUK_HOBJECT_GET_ESIZE(obj)) {
/* only need to guarantee 1 more slot, but allocation growth is in chunks */
DUK_DDD(DUK_DDDPRINT("entry part full, allocate space for one more entry"));
duk__grow_props_for_new_entry_item(thr, obj);
}
DUK_ASSERT(DUK_HOBJECT_GET_ENEXT(obj) < DUK_HOBJECT_GET_ESIZE(obj));
idx = DUK_HOBJECT_POSTINC_ENEXT(obj);
/* previous value is assumed to be garbage, so don't touch it */
DUK_HOBJECT_E_SET_KEY(thr->heap, obj, idx, key);
DUK_HSTRING_INCREF(thr, key);
#if defined(DUK_USE_HOBJECT_HASH_PART)
if (DUK_UNLIKELY(DUK_HOBJECT_GET_HSIZE(obj) > 0)) {
duk_uint32_t n, mask;
duk_uint32_t i, step;
duk_uint32_t *h_base = DUK_HOBJECT_H_GET_BASE(thr->heap, obj);
n = DUK_HOBJECT_GET_HSIZE(obj);
mask = n - 1;
i = DUK_HSTRING_GET_HASH(key) & mask;
step = 1; /* Cache friendly but clustering prone. */
for (;;) {
duk_uint32_t t = h_base[i];
if (t == DUK__HASH_UNUSED || t == DUK__HASH_DELETED) {
DUK_DDD(DUK_DDDPRINT("duk__hobject_alloc_entry_checked() inserted key into hash part, %ld -> %ld",
(long) i, (long) idx));
DUK_ASSERT_DISABLE(i >= 0); /* unsigned */
DUK_ASSERT(i < DUK_HOBJECT_GET_HSIZE(obj));
DUK_ASSERT_DISABLE(idx >= 0);
DUK_ASSERT(idx < DUK_HOBJECT_GET_ESIZE(obj));
h_base[i] = idx;
break;
}
DUK_DDD(DUK_DDDPRINT("duk__hobject_alloc_entry_checked() miss %ld", (long) i));
i = (i + step) & mask;
/* Guaranteed to finish (hash is larger than #props). */
}
}
#endif /* DUK_USE_HOBJECT_HASH_PART */
/* Note: we could return the hash index here too, but it's not
* needed right now.
*/
DUK_ASSERT_DISABLE(idx >= 0);
DUK_ASSERT(idx < DUK_HOBJECT_GET_ESIZE(obj));
DUK_ASSERT(idx < DUK_HOBJECT_GET_ENEXT(obj));
return (duk_int_t) idx;
}
/*
* Object internal value
*
* Returned value is guaranteed to be reachable / incref'd, caller does not need
* to incref OR decref. No proxies or accessors are invoked, no prototype walk.
*/
DUK_INTERNAL duk_tval *duk_hobject_get_internal_value_tval_ptr(duk_heap *heap, duk_hobject *obj) {
return duk_hobject_find_entry_tval_ptr_stridx(heap, obj, DUK_STRIDX_INT_VALUE);
}
DUK_LOCAL duk_heaphdr *duk_hobject_get_internal_value_heaphdr(duk_heap *heap, duk_hobject *obj) {
duk_tval *tv;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(obj != NULL);
tv = duk_hobject_get_internal_value_tval_ptr(heap, obj);
if (tv != NULL) {
duk_heaphdr *h = DUK_TVAL_GET_HEAPHDR(tv);
DUK_ASSERT(h != NULL);
return h;
}
return NULL;
}
DUK_INTERNAL duk_hstring *duk_hobject_get_internal_value_string(duk_heap *heap, duk_hobject *obj) {
duk_hstring *h;
h = (duk_hstring *) duk_hobject_get_internal_value_heaphdr(heap, obj);
if (h != NULL) {
DUK_ASSERT(DUK_HEAPHDR_IS_STRING((duk_heaphdr *) h));
}
return h;
}
DUK_LOCAL duk_hobject *duk__hobject_get_entry_object_stridx(duk_heap *heap, duk_hobject *obj, duk_small_uint_t stridx) {
duk_tval *tv;
duk_hobject *h;
tv = duk_hobject_find_entry_tval_ptr_stridx(heap, obj, stridx);
if (tv != NULL && DUK_TVAL_IS_OBJECT(tv)) {
h = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h != NULL);
return h;
}
return NULL;
}
DUK_INTERNAL duk_harray *duk_hobject_get_formals(duk_hthread *thr, duk_hobject *obj) {
duk_harray *h;
h = (duk_harray *) duk__hobject_get_entry_object_stridx(thr->heap, obj, DUK_STRIDX_INT_FORMALS);
if (h != NULL) {
DUK_ASSERT(DUK_HOBJECT_IS_ARRAY((duk_hobject *) h));
DUK_ASSERT(h->length <= DUK_HOBJECT_GET_ASIZE((duk_hobject *) h));
}
return h;
}
DUK_INTERNAL duk_hobject *duk_hobject_get_varmap(duk_hthread *thr, duk_hobject *obj) {
duk_hobject *h;
h = duk__hobject_get_entry_object_stridx(thr->heap, obj, DUK_STRIDX_INT_VARMAP);
return h;
}
/*
* Arguments handling helpers (argument map mainly).
*
* An arguments object has exotic behavior for some numeric indices.
* Accesses may translate to identifier operations which may have
* arbitrary side effects (potentially invalidating any duk_tval
* pointers).
*/
/* Lookup 'key' from arguments internal 'map', perform a variable lookup
* if mapped, and leave the result on top of stack (and return non-zero).
* Used in E5 Section 10.6 algorithms [[Get]] and [[GetOwnProperty]].
*/
DUK_LOCAL
duk_bool_t duk__lookup_arguments_map(duk_hthread *thr,
duk_hobject *obj,
duk_hstring *key,
duk_propdesc *temp_desc,
duk_hobject **out_map,
duk_hobject **out_varenv) {
duk_hobject *map;
duk_hobject *varenv;
duk_bool_t rc;
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_DDD(DUK_DDDPRINT("arguments map lookup: thr=%p, obj=%p, key=%p, temp_desc=%p "
"(obj -> %!O, key -> %!O)",
(void *) thr, (void *) obj, (void *) key, (void *) temp_desc,
(duk_heaphdr *) obj, (duk_heaphdr *) key));
if (!duk_hobject_get_own_propdesc(thr, obj, DUK_HTHREAD_STRING_INT_MAP(thr), temp_desc, DUK_GETDESC_FLAG_PUSH_VALUE)) {
DUK_DDD(DUK_DDDPRINT("-> no 'map'"));
return 0;
}
map = duk_require_hobject(thr, -1);
DUK_ASSERT(map != NULL);
duk_pop_unsafe(thr); /* map is reachable through obj */
if (!duk_hobject_get_own_propdesc(thr, map, key, temp_desc, DUK_GETDESC_FLAG_PUSH_VALUE)) {
DUK_DDD(DUK_DDDPRINT("-> 'map' exists, but key not in map"));
return 0;
}
/* [... varname] */
DUK_DDD(DUK_DDDPRINT("-> 'map' exists, and contains key, key is mapped to argument/variable binding %!T",
(duk_tval *) duk_get_tval(thr, -1)));
DUK_ASSERT(duk_is_string(thr, -1)); /* guaranteed when building arguments */
/* get varenv for varname (callee's declarative lexical environment) */
rc = duk_hobject_get_own_propdesc(thr, obj, DUK_HTHREAD_STRING_INT_VARENV(thr), temp_desc, DUK_GETDESC_FLAG_PUSH_VALUE);
DUK_UNREF(rc);
DUK_ASSERT(rc != 0); /* arguments MUST have an initialized lexical environment reference */
varenv = duk_require_hobject(thr, -1);
DUK_ASSERT(varenv != NULL);
duk_pop_unsafe(thr); /* varenv remains reachable through 'obj' */
DUK_DDD(DUK_DDDPRINT("arguments varenv is: %!dO", (duk_heaphdr *) varenv));
/* success: leave varname in stack */
*out_map = map;
*out_varenv = varenv;
return 1; /* [... varname] */
}
/* Lookup 'key' from arguments internal 'map', and leave replacement value
* on stack top if mapped (and return non-zero).
* Used in E5 Section 10.6 algorithm for [[GetOwnProperty]] (used by [[Get]]).
*/
DUK_LOCAL duk_bool_t duk__check_arguments_map_for_get(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *temp_desc) {
duk_hobject *map;
duk_hobject *varenv;
duk_hstring *varname;
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
if (!duk__lookup_arguments_map(thr, obj, key, temp_desc, &map, &varenv)) {
DUK_DDD(DUK_DDDPRINT("arguments: key not mapped, no exotic get behavior"));
return 0;
}
/* [... varname] */
varname = duk_require_hstring(thr, -1);
DUK_ASSERT(varname != NULL);
duk_pop_unsafe(thr); /* varname is still reachable */
DUK_DDD(DUK_DDDPRINT("arguments object automatic getvar for a bound variable; "
"key=%!O, varname=%!O",
(duk_heaphdr *) key,
(duk_heaphdr *) varname));
(void) duk_js_getvar_envrec(thr, varenv, varname, 1 /*throw*/);
/* [... value this_binding] */
duk_pop_unsafe(thr);
/* leave result on stack top */
return 1;
}
/* Lookup 'key' from arguments internal 'map', perform a variable write if mapped.
* Used in E5 Section 10.6 algorithm for [[DefineOwnProperty]] (used by [[Put]]).
* Assumes stack top contains 'put' value (which is NOT popped).
*/
DUK_LOCAL void duk__check_arguments_map_for_put(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *temp_desc, duk_bool_t throw_flag) {
duk_hobject *map;
duk_hobject *varenv;
duk_hstring *varname;
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
if (!duk__lookup_arguments_map(thr, obj, key, temp_desc, &map, &varenv)) {
DUK_DDD(DUK_DDDPRINT("arguments: key not mapped, no exotic put behavior"));
return;
}
/* [... put_value varname] */
varname = duk_require_hstring(thr, -1);
DUK_ASSERT(varname != NULL);
duk_pop_unsafe(thr); /* varname is still reachable */
DUK_DDD(DUK_DDDPRINT("arguments object automatic putvar for a bound variable; "
"key=%!O, varname=%!O, value=%!T",
(duk_heaphdr *) key,
(duk_heaphdr *) varname,
(duk_tval *) duk_require_tval(thr, -1)));
/* [... put_value] */
/*
* Note: although arguments object variable mappings are only established
* for non-strict functions (and a call to a non-strict function created
* the arguments object in question), an inner strict function may be doing
* the actual property write. Hence the throw_flag applied here comes from
* the property write call.
*/
duk_js_putvar_envrec(thr, varenv, varname, duk_require_tval(thr, -1), throw_flag);
/* [... put_value] */
}
/* Lookup 'key' from arguments internal 'map', delete mapping if found.
* Used in E5 Section 10.6 algorithm for [[Delete]]. Note that the
* variable/argument itself (where the map points) is not deleted.
*/
DUK_LOCAL void duk__check_arguments_map_for_delete(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *temp_desc) {
duk_hobject *map;
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
if (!duk_hobject_get_own_propdesc(thr, obj, DUK_HTHREAD_STRING_INT_MAP(thr), temp_desc, DUK_GETDESC_FLAG_PUSH_VALUE)) {
DUK_DDD(DUK_DDDPRINT("arguments: key not mapped, no exotic delete behavior"));
return;
}
map = duk_require_hobject(thr, -1);
DUK_ASSERT(map != NULL);
duk_pop_unsafe(thr); /* map is reachable through obj */
DUK_DDD(DUK_DDDPRINT("-> have 'map', delete key %!O from map (if exists)); ignore result",
(duk_heaphdr *) key));
/* Note: no recursion issue, we can trust 'map' to behave */
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_BEHAVIOR(map));
DUK_DDD(DUK_DDDPRINT("map before deletion: %!O", (duk_heaphdr *) map));
(void) duk_hobject_delprop_raw(thr, map, key, 0); /* ignore result */
DUK_DDD(DUK_DDDPRINT("map after deletion: %!O", (duk_heaphdr *) map));
}
/*
* ECMAScript compliant [[GetOwnProperty]](P), for internal use only.
*
* If property is found:
* - Fills descriptor fields to 'out_desc'
* - If DUK_GETDESC_FLAG_PUSH_VALUE is set, pushes a value related to the
* property onto the stack ('undefined' for accessor properties).
* - Returns non-zero
*
* If property is not found:
* - 'out_desc' is left in untouched state (possibly garbage)
* - Nothing is pushed onto the stack (not even with DUK_GETDESC_FLAG_PUSH_VALUE
* set)
* - Returns zero
*
* Notes:
*
* - Getting a property descriptor may cause an allocation (and hence
* GC) to take place, hence reachability and refcount of all related
* values matter. Reallocation of value stack, properties, etc may
* invalidate many duk_tval pointers (concretely, those which reside
* in memory areas subject to reallocation). However, heap object
* pointers are never affected (heap objects have stable pointers).
*
* - The value of a plain property is always reachable and has a non-zero
* reference count.
*
* - The value of a virtual property is not necessarily reachable from
* elsewhere and may have a refcount of zero. Hence we push it onto
* the valstack for the caller, which ensures it remains reachable
* while it is needed.
*
* - There are no virtual accessor properties. Hence, all getters and
* setters are always related to concretely stored properties, which
* ensures that the get/set functions in the resulting descriptor are
* reachable and have non-zero refcounts. Should there be virtual
* accessor properties later, this would need to change.
*/
DUK_LOCAL duk_bool_t duk__get_own_propdesc_raw(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_uint32_t arr_idx, duk_propdesc *out_desc, duk_small_uint_t flags) {
duk_tval *tv;
DUK_DDD(DUK_DDDPRINT("duk_hobject_get_own_propdesc: thr=%p, obj=%p, key=%p, out_desc=%p, flags=%lx, "
"arr_idx=%ld (obj -> %!O, key -> %!O)",
(void *) thr, (void *) obj, (void *) key, (void *) out_desc,
(long) flags, (long) arr_idx,
(duk_heaphdr *) obj, (duk_heaphdr *) key));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(out_desc != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_STATS_INC(thr->heap, stats_getownpropdesc_count);
/* Each code path returning 1 (= found) must fill in all the output
* descriptor fields. We don't do it beforehand because it'd be
* unnecessary work if the property isn't found and would happen
* multiple times for an inheritance chain.
*/
DUK_ASSERT_SET_GARBAGE(out_desc, sizeof(*out_desc));
#if 0
out_desc->flags = 0;
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = -1;
#endif
/*
* Try entries part first because it's the common case.
*
* Array part lookups are usually handled by the array fast path, and
* are not usually inherited. Array and entry parts never contain the
* same keys so the entry part vs. array part order doesn't matter.
*/
if (duk_hobject_find_entry(thr->heap, obj, key, &out_desc->e_idx, &out_desc->h_idx)) {
duk_int_t e_idx = out_desc->e_idx;
DUK_ASSERT(out_desc->e_idx >= 0);
out_desc->a_idx = -1;
out_desc->flags = DUK_HOBJECT_E_GET_FLAGS(thr->heap, obj, e_idx);
out_desc->get = NULL;
out_desc->set = NULL;
if (DUK_UNLIKELY(out_desc->flags & DUK_PROPDESC_FLAG_ACCESSOR)) {
DUK_DDD(DUK_DDDPRINT("-> found accessor property in entry part"));
out_desc->get = DUK_HOBJECT_E_GET_VALUE_GETTER(thr->heap, obj, e_idx);
out_desc->set = DUK_HOBJECT_E_GET_VALUE_SETTER(thr->heap, obj, e_idx);
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
/* a dummy undefined value is pushed to make valstack
* behavior uniform for caller
*/
duk_push_undefined(thr);
}
} else {
DUK_DDD(DUK_DDDPRINT("-> found plain property in entry part"));
tv = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, e_idx);
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
duk_push_tval(thr, tv);
}
}
goto prop_found;
}
/*
* Try array part.
*/
if (DUK_HOBJECT_HAS_ARRAY_PART(obj) && arr_idx != DUK__NO_ARRAY_INDEX) {
if (arr_idx < DUK_HOBJECT_GET_ASIZE(obj)) {
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, arr_idx);
if (!DUK_TVAL_IS_UNUSED(tv)) {
DUK_DDD(DUK_DDDPRINT("-> found in array part"));
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
duk_push_tval(thr, tv);
}
/* implicit attributes */
out_desc->flags = DUK_PROPDESC_FLAG_WRITABLE |
DUK_PROPDESC_FLAG_CONFIGURABLE |
DUK_PROPDESC_FLAG_ENUMERABLE;
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = (duk_int_t) arr_idx; /* XXX: limit 2G due to being signed */
goto prop_found;
}
}
}
DUK_DDD(DUK_DDDPRINT("-> not found as a concrete property"));
/*
* Not found as a concrete property, check for virtual properties.
*/
if (!DUK_HOBJECT_HAS_VIRTUAL_PROPERTIES(obj)) {
/* Quick skip. */
goto prop_not_found;
}
if (DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
duk_harray *a;
DUK_DDD(DUK_DDDPRINT("array object exotic property get for key: %!O, arr_idx: %ld",
(duk_heaphdr *) key, (long) arr_idx));
a = (duk_harray *) obj;
DUK_HARRAY_ASSERT_VALID(a);
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
DUK_DDD(DUK_DDDPRINT("-> found, key is 'length', length exotic behavior"));
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
duk_push_uint(thr, (duk_uint_t) a->length);
}
out_desc->flags = DUK_PROPDESC_FLAG_VIRTUAL;
if (DUK_HARRAY_LENGTH_WRITABLE(a)) {
out_desc->flags |= DUK_PROPDESC_FLAG_WRITABLE;
}
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = -1;
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj));
goto prop_found_noexotic; /* cannot be arguments exotic */
}
} else if (DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(obj)) {
DUK_DDD(DUK_DDDPRINT("string object exotic property get for key: %!O, arr_idx: %ld",
(duk_heaphdr *) key, (long) arr_idx));
/* XXX: charlen; avoid multiple lookups? */
if (arr_idx != DUK__NO_ARRAY_INDEX) {
duk_hstring *h_val;
DUK_DDD(DUK_DDDPRINT("array index exists"));
h_val = duk_hobject_get_internal_value_string(thr->heap, obj);
DUK_ASSERT(h_val);
if (arr_idx < DUK_HSTRING_GET_CHARLEN(h_val)) {
DUK_DDD(DUK_DDDPRINT("-> found, array index inside string"));
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
duk_push_hstring(thr, h_val);
duk_substring(thr, -1, arr_idx, arr_idx + 1); /* [str] -> [substr] */
}
out_desc->flags = DUK_PROPDESC_FLAG_ENUMERABLE | /* E5 Section 15.5.5.2 */
DUK_PROPDESC_FLAG_VIRTUAL;
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = -1;
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj));
goto prop_found_noexotic; /* cannot be arguments exotic */
} else {
/* index is above internal string length -> property is fully normal */
DUK_DDD(DUK_DDDPRINT("array index outside string -> normal property"));
}
} else if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
duk_hstring *h_val;
DUK_DDD(DUK_DDDPRINT("-> found, key is 'length', length exotic behavior"));
h_val = duk_hobject_get_internal_value_string(thr->heap, obj);
DUK_ASSERT(h_val != NULL);
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
duk_push_uint(thr, (duk_uint_t) DUK_HSTRING_GET_CHARLEN(h_val));
}
out_desc->flags = DUK_PROPDESC_FLAG_VIRTUAL; /* E5 Section 15.5.5.1 */
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = -1;
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj));
goto prop_found_noexotic; /* cannot be arguments exotic */
}
}
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
else if (DUK_HOBJECT_IS_BUFOBJ(obj)) {
duk_hbufobj *h_bufobj;
duk_uint_t byte_off;
duk_small_uint_t elem_size;
h_bufobj = (duk_hbufobj *) obj;
DUK_HBUFOBJ_ASSERT_VALID(h_bufobj);
DUK_DDD(DUK_DDDPRINT("bufobj property get for key: %!O, arr_idx: %ld",
(duk_heaphdr *) key, (long) arr_idx));
if (arr_idx != DUK__NO_ARRAY_INDEX && DUK_HBUFOBJ_HAS_VIRTUAL_INDICES(h_bufobj)) {
DUK_DDD(DUK_DDDPRINT("array index exists"));
/* Careful with wrapping: arr_idx upshift may easily wrap, whereas
* length downshift won't.
*/
if (arr_idx < (h_bufobj->length >> h_bufobj->shift)) {
byte_off = arr_idx << h_bufobj->shift; /* no wrap assuming h_bufobj->length is valid */
elem_size = (duk_small_uint_t) (1U << h_bufobj->shift);
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
duk_uint8_t *data;
if (h_bufobj->buf != NULL && DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_bufobj, byte_off + elem_size)) {
data = (duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_bufobj->buf) + h_bufobj->offset + byte_off;
duk_hbufobj_push_validated_read(thr, h_bufobj, data, elem_size);
} else {
DUK_D(DUK_DPRINT("bufobj access out of underlying buffer, ignoring (read zero)"));
duk_push_uint(thr, 0);
}
}
out_desc->flags = DUK_PROPDESC_FLAG_WRITABLE |
DUK_PROPDESC_FLAG_VIRTUAL;
if (DUK_HOBJECT_GET_CLASS_NUMBER(obj) != DUK_HOBJECT_CLASS_ARRAYBUFFER) {
/* ArrayBuffer indices are non-standard and are
* non-enumerable to avoid their serialization.
*/
out_desc->flags |= DUK_PROPDESC_FLAG_ENUMERABLE;
}
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = -1;
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj));
goto prop_found_noexotic; /* cannot be e.g. arguments exotic, since exotic 'traits' are mutually exclusive */
} else {
/* index is above internal buffer length -> property is fully normal */
DUK_DDD(DUK_DDDPRINT("array index outside buffer -> normal property"));
}
} else if (key == DUK_HTHREAD_STRING_LENGTH(thr) && DUK_HBUFOBJ_HAS_VIRTUAL_INDICES(h_bufobj)) {
DUK_DDD(DUK_DDDPRINT("-> found, key is 'length', length exotic behavior"));
if (flags & DUK_GETDESC_FLAG_PUSH_VALUE) {
/* Length in elements: take into account shift, but
* intentionally don't check the underlying buffer here.
*/
duk_push_uint(thr, h_bufobj->length >> h_bufobj->shift);
}
out_desc->flags = DUK_PROPDESC_FLAG_VIRTUAL;
out_desc->get = NULL;
out_desc->set = NULL;
out_desc->e_idx = -1;
out_desc->h_idx = -1;
out_desc->a_idx = -1;
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj));
goto prop_found_noexotic; /* cannot be arguments exotic */
}
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/* Array properties have exotic behavior but they are concrete,
* so no special handling here.
*
* Arguments exotic behavior (E5 Section 10.6, [[GetOwnProperty]]
* is only relevant as a post-check implemented below; hence no
* check here.
*/
/*
* Not found as concrete or virtual.
*/
prop_not_found:
DUK_DDD(DUK_DDDPRINT("-> not found (virtual, entry part, or array part)"));
DUK_STATS_INC(thr->heap, stats_getownpropdesc_miss);
return 0;
/*
* Found.
*
* Arguments object has exotic post-processing, see E5 Section 10.6,
* description of [[GetOwnProperty]] variant for arguments.
*/
prop_found:
DUK_DDD(DUK_DDDPRINT("-> property found, checking for arguments exotic post-behavior"));
/* Notes:
* - Only numbered indices are relevant, so arr_idx fast reject is good
* (this is valid unless there are more than 4**32-1 arguments).
* - Since variable lookup has no side effects, this can be skipped if
* DUK_GETDESC_FLAG_PUSH_VALUE is not set.
*/
if (DUK_UNLIKELY(DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj) &&
arr_idx != DUK__NO_ARRAY_INDEX &&
(flags & DUK_GETDESC_FLAG_PUSH_VALUE))) {
duk_propdesc temp_desc;
/* Magically bound variable cannot be an accessor. However,
* there may be an accessor property (or a plain property) in
* place with magic behavior removed. This happens e.g. when
* a magic property is redefined with defineProperty().
* Cannot assert for "not accessor" here.
*/
/* replaces top of stack with new value if necessary */
DUK_ASSERT((flags & DUK_GETDESC_FLAG_PUSH_VALUE) != 0);
/* This can perform a variable lookup but only into a declarative
* environment which has no side effects.
*/
if (duk__check_arguments_map_for_get(thr, obj, key, &temp_desc)) {
DUK_DDD(DUK_DDDPRINT("-> arguments exotic behavior overrides result: %!T -> %!T",
(duk_tval *) duk_get_tval(thr, -2),
(duk_tval *) duk_get_tval(thr, -1)));
/* [... old_result result] -> [... result] */
duk_remove_m2(thr);
}
}
prop_found_noexotic:
DUK_STATS_INC(thr->heap, stats_getownpropdesc_hit);
return 1;
}
DUK_INTERNAL duk_bool_t duk_hobject_get_own_propdesc(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *out_desc, duk_small_uint_t flags) {
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(out_desc != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
return duk__get_own_propdesc_raw(thr, obj, key, DUK_HSTRING_GET_ARRIDX_SLOW(key), out_desc, flags);
}
/*
* ECMAScript compliant [[GetProperty]](P), for internal use only.
*
* If property is found:
* - Fills descriptor fields to 'out_desc'
* - If DUK_GETDESC_FLAG_PUSH_VALUE is set, pushes a value related to the
* property onto the stack ('undefined' for accessor properties).
* - Returns non-zero
*
* If property is not found:
* - 'out_desc' is left in untouched state (possibly garbage)
* - Nothing is pushed onto the stack (not even with DUK_GETDESC_FLAG_PUSH_VALUE
* set)
* - Returns zero
*
* May cause arbitrary side effects and invalidate (most) duk_tval
* pointers.
*/
DUK_LOCAL duk_bool_t duk__get_propdesc(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_propdesc *out_desc, duk_small_uint_t flags) {
duk_hobject *curr;
duk_uint32_t arr_idx;
duk_uint_t sanity;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(out_desc != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_STATS_INC(thr->heap, stats_getpropdesc_count);
arr_idx = DUK_HSTRING_GET_ARRIDX_FAST(key);
DUK_DDD(DUK_DDDPRINT("duk__get_propdesc: thr=%p, obj=%p, key=%p, out_desc=%p, flags=%lx, "
"arr_idx=%ld (obj -> %!O, key -> %!O)",
(void *) thr, (void *) obj, (void *) key, (void *) out_desc,
(long) flags, (long) arr_idx,
(duk_heaphdr *) obj, (duk_heaphdr *) key));
curr = obj;
DUK_ASSERT(curr != NULL);
sanity = DUK_HOBJECT_PROTOTYPE_CHAIN_SANITY;
do {
if (duk__get_own_propdesc_raw(thr, curr, key, arr_idx, out_desc, flags)) {
/* stack contains value (if requested), 'out_desc' is set */
DUK_STATS_INC(thr->heap, stats_getpropdesc_hit);
return 1;
}
/* not found in 'curr', next in prototype chain; impose max depth */
if (DUK_UNLIKELY(sanity-- == 0)) {
if (flags & DUK_GETDESC_FLAG_IGNORE_PROTOLOOP) {
/* treat like property not found */
break;
} else {
DUK_ERROR_RANGE(thr, DUK_STR_PROTOTYPE_CHAIN_LIMIT);
DUK_WO_NORETURN(return 0;);
}
}
curr = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, curr);
} while (curr != NULL);
/* out_desc is left untouched (possibly garbage), caller must use return
* value to determine whether out_desc can be looked up
*/
DUK_STATS_INC(thr->heap, stats_getpropdesc_miss);
return 0;
}
/*
* Shallow fast path checks for accessing array elements with numeric
* indices. The goal is to try to avoid coercing an array index to an
* (interned) string for the most common lookups, in particular, for
* standard Array objects.
*
* Interning is avoided but only for a very narrow set of cases:
* - Object has array part, index is within array allocation, and
* value is not unused (= key exists)
* - Object has no interfering exotic behavior (e.g. arguments or
* string object exotic behaviors interfere, array exotic
* behavior does not).
*
* Current shortcoming: if key does not exist (even if it is within
* the array allocation range) a slow path lookup with interning is
* always required. This can probably be fixed so that there is a
* quick fast path for non-existent elements as well, at least for
* standard Array objects.
*/
#if defined(DUK_USE_ARRAY_PROP_FASTPATH)
DUK_LOCAL duk_tval *duk__getprop_shallow_fastpath_array_tval(duk_hthread *thr, duk_hobject *obj, duk_tval *tv_key) {
duk_tval *tv;
duk_uint32_t idx;
DUK_UNREF(thr);
if (!(DUK_HOBJECT_HAS_ARRAY_PART(obj) &&
!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj) &&
!DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(obj) &&
!DUK_HOBJECT_IS_BUFOBJ(obj) &&
!DUK_HOBJECT_IS_PROXY(obj))) {
/* Must have array part and no conflicting exotic behaviors.
* Doesn't need to have array special behavior, e.g. Arguments
* object has array part.
*/
return NULL;
}
/* Arrays never have other exotic behaviors. */
DUK_DDD(DUK_DDDPRINT("fast path attempt (no exotic string/arguments/buffer "
"behavior, object has array part)"));
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
idx = duk__tval_fastint_to_arr_idx(tv_key);
} else
#endif
if (DUK_TVAL_IS_DOUBLE(tv_key)) {
idx = duk__tval_number_to_arr_idx(tv_key);
} else {
DUK_DDD(DUK_DDDPRINT("key is not a number"));
return NULL;
}
/* If index is not valid, idx will be DUK__NO_ARRAY_INDEX which
* is 0xffffffffUL. We don't need to check for that explicitly
* because 0xffffffffUL will never be inside object 'a_size'.
*/
if (idx >= DUK_HOBJECT_GET_ASIZE(obj)) {
DUK_DDD(DUK_DDDPRINT("key is not an array index or outside array part"));
return NULL;
}
DUK_ASSERT(idx != 0xffffffffUL);
DUK_ASSERT(idx != DUK__NO_ARRAY_INDEX);
/* XXX: for array instances we could take a shortcut here and assume
* Array.prototype doesn't contain an array index property.
*/
DUK_DDD(DUK_DDDPRINT("key is a valid array index and inside array part"));
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, idx);
if (!DUK_TVAL_IS_UNUSED(tv)) {
DUK_DDD(DUK_DDDPRINT("-> fast path successful"));
return tv;
}
DUK_DDD(DUK_DDDPRINT("fast path attempt failed, fall back to slow path"));
return NULL;
}
DUK_LOCAL duk_bool_t duk__putprop_shallow_fastpath_array_tval(duk_hthread *thr, duk_hobject *obj, duk_tval *tv_key, duk_tval *tv_val) {
duk_tval *tv;
duk_harray *a;
duk_uint32_t idx;
duk_uint32_t old_len, new_len;
if (!(DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj) &&
DUK_HOBJECT_HAS_ARRAY_PART(obj) &&
DUK_HOBJECT_HAS_EXTENSIBLE(obj))) {
return 0;
}
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)); /* caller ensures */
a = (duk_harray *) obj;
DUK_HARRAY_ASSERT_VALID(a);
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
idx = duk__tval_fastint_to_arr_idx(tv_key);
} else
#endif
if (DUK_TVAL_IS_DOUBLE(tv_key)) {
idx = duk__tval_number_to_arr_idx(tv_key);
} else {
DUK_DDD(DUK_DDDPRINT("key is not a number"));
return 0;
}
/* If index is not valid, idx will be DUK__NO_ARRAY_INDEX which
* is 0xffffffffUL. We don't need to check for that explicitly
* because 0xffffffffUL will never be inside object 'a_size'.
*/
if (idx >= DUK_HOBJECT_GET_ASIZE(obj)) { /* for resizing of array part, use slow path */
return 0;
}
DUK_ASSERT(idx != 0xffffffffUL);
DUK_ASSERT(idx != DUK__NO_ARRAY_INDEX);
old_len = a->length;
if (idx >= old_len) {
DUK_DDD(DUK_DDDPRINT("write new array entry requires length update "
"(arr_idx=%ld, old_len=%ld)",
(long) idx, (long) old_len));
if (DUK_HARRAY_LENGTH_NONWRITABLE(a)) {
/* The correct behavior here is either a silent error
* or a TypeError, depending on strictness. Fall back
* to the slow path to handle the situation.
*/
return 0;
}
new_len = idx + 1;
((duk_harray *) obj)->length = new_len;
}
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, idx);
DUK_TVAL_SET_TVAL_UPDREF(thr, tv, tv_val); /* side effects */
DUK_DDD(DUK_DDDPRINT("array fast path success for index %ld", (long) idx));
return 1;
}
#endif /* DUK_USE_ARRAY_PROP_FASTPATH */
/*
* Fast path for bufobj getprop/putprop
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_LOCAL duk_bool_t duk__getprop_fastpath_bufobj_tval(duk_hthread *thr, duk_hobject *obj, duk_tval *tv_key) {
duk_uint32_t idx;
duk_hbufobj *h_bufobj;
duk_uint_t byte_off;
duk_small_uint_t elem_size;
duk_uint8_t *data;
if (!DUK_HOBJECT_IS_BUFOBJ(obj)) {
return 0;
}
h_bufobj = (duk_hbufobj *) obj;
if (!DUK_HBUFOBJ_HAS_VIRTUAL_INDICES(h_bufobj)) {
return 0;
}
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
idx = duk__tval_fastint_to_arr_idx(tv_key);
} else
#endif
if (DUK_TVAL_IS_DOUBLE(tv_key)) {
idx = duk__tval_number_to_arr_idx(tv_key);
} else {
return 0;
}
/* If index is not valid, idx will be DUK__NO_ARRAY_INDEX which
* is 0xffffffffUL. We don't need to check for that explicitly
* because 0xffffffffUL will never be inside bufobj length.
*/
/* Careful with wrapping (left shifting idx would be unsafe). */
if (idx >= (h_bufobj->length >> h_bufobj->shift)) {
return 0;
}
DUK_ASSERT(idx != DUK__NO_ARRAY_INDEX);
byte_off = idx << h_bufobj->shift; /* no wrap assuming h_bufobj->length is valid */
elem_size = (duk_small_uint_t) (1U << h_bufobj->shift);
if (h_bufobj->buf != NULL && DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_bufobj, byte_off + elem_size)) {
data = (duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_bufobj->buf) + h_bufobj->offset + byte_off;
duk_hbufobj_push_validated_read(thr, h_bufobj, data, elem_size);
} else {
DUK_D(DUK_DPRINT("bufobj access out of underlying buffer, ignoring (read zero)"));
duk_push_uint(thr, 0);
}
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_LOCAL duk_bool_t duk__putprop_fastpath_bufobj_tval(duk_hthread *thr, duk_hobject *obj, duk_tval *tv_key, duk_tval *tv_val) {
duk_uint32_t idx;
duk_hbufobj *h_bufobj;
duk_uint_t byte_off;
duk_small_uint_t elem_size;
duk_uint8_t *data;
if (!(DUK_HOBJECT_IS_BUFOBJ(obj) &&
DUK_TVAL_IS_NUMBER(tv_val))) {
return 0;
}
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)); /* caller ensures; rom objects are never bufobjs now */
h_bufobj = (duk_hbufobj *) obj;
if (!DUK_HBUFOBJ_HAS_VIRTUAL_INDICES(h_bufobj)) {
return 0;
}
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
idx = duk__tval_fastint_to_arr_idx(tv_key);
} else
#endif
if (DUK_TVAL_IS_DOUBLE(tv_key)) {
idx = duk__tval_number_to_arr_idx(tv_key);
} else {
return 0;
}
/* If index is not valid, idx will be DUK__NO_ARRAY_INDEX which
* is 0xffffffffUL. We don't need to check for that explicitly
* because 0xffffffffUL will never be inside bufobj length.
*/
/* Careful with wrapping (left shifting idx would be unsafe). */
if (idx >= (h_bufobj->length >> h_bufobj->shift)) {
return 0;
}
DUK_ASSERT(idx != DUK__NO_ARRAY_INDEX);
byte_off = idx << h_bufobj->shift; /* no wrap assuming h_bufobj->length is valid */
elem_size = (duk_small_uint_t) (1U << h_bufobj->shift);
/* Value is required to be a number in the fast path so there
* are no side effects in write coercion.
*/
duk_push_tval(thr, tv_val);
DUK_ASSERT(duk_is_number(thr, -1));
if (h_bufobj->buf != NULL && DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_bufobj, byte_off + elem_size)) {
data = (duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_bufobj->buf) + h_bufobj->offset + byte_off;
duk_hbufobj_validated_write(thr, h_bufobj, data, elem_size);
} else {
DUK_D(DUK_DPRINT("bufobj access out of underlying buffer, ignoring (write skipped)"));
}
duk_pop_unsafe(thr);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* GETPROP: ECMAScript property read.
*/
DUK_INTERNAL duk_bool_t duk_hobject_getprop(duk_hthread *thr, duk_tval *tv_obj, duk_tval *tv_key) {
duk_tval tv_obj_copy;
duk_tval tv_key_copy;
duk_hobject *curr = NULL;
duk_hstring *key = NULL;
duk_uint32_t arr_idx = DUK__NO_ARRAY_INDEX;
duk_propdesc desc;
duk_uint_t sanity;
DUK_DDD(DUK_DDDPRINT("getprop: thr=%p, obj=%p, key=%p (obj -> %!T, key -> %!T)",
(void *) thr, (void *) tv_obj, (void *) tv_key,
(duk_tval *) tv_obj, (duk_tval *) tv_key));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(tv_obj != NULL);
DUK_ASSERT(tv_key != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_STATS_INC(thr->heap, stats_getprop_all);
/*
* Make a copy of tv_obj, tv_key, and tv_val to avoid any issues of
* them being invalidated by a valstack resize.
*
* XXX: this is now an overkill for many fast paths. Rework this
* to be faster (although switching to a valstack discipline might
* be a better solution overall).
*/
DUK_TVAL_SET_TVAL(&tv_obj_copy, tv_obj);
DUK_TVAL_SET_TVAL(&tv_key_copy, tv_key);
tv_obj = &tv_obj_copy;
tv_key = &tv_key_copy;
/*
* Coercion and fast path processing
*/
switch (DUK_TVAL_GET_TAG(tv_obj)) {
case DUK_TAG_UNDEFINED:
case DUK_TAG_NULL: {
/* Note: unconditional throw */
DUK_DDD(DUK_DDDPRINT("base object is undefined or null -> reject"));
#if defined(DUK_USE_PARANOID_ERRORS)
DUK_ERROR_TYPE(thr, DUK_STR_INVALID_BASE);
#else
DUK_ERROR_FMT2(thr, DUK_ERR_TYPE_ERROR, "cannot read property %s of %s",
duk_push_string_tval_readable(thr, tv_key), duk_push_string_tval_readable(thr, tv_obj));
#endif
DUK_WO_NORETURN(return 0;);
break;
}
case DUK_TAG_BOOLEAN: {
DUK_DDD(DUK_DDDPRINT("base object is a boolean, start lookup from boolean prototype"));
curr = thr->builtins[DUK_BIDX_BOOLEAN_PROTOTYPE];
break;
}
case DUK_TAG_STRING: {
duk_hstring *h = DUK_TVAL_GET_STRING(tv_obj);
duk_int_t pop_count;
if (DUK_UNLIKELY(DUK_HSTRING_HAS_SYMBOL(h))) {
/* Symbols (ES2015 or hidden) don't have virtual properties. */
DUK_DDD(DUK_DDDPRINT("base object is a symbol, start lookup from symbol prototype"));
curr = thr->builtins[DUK_BIDX_SYMBOL_PROTOTYPE];
break;
}
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
arr_idx = duk__tval_fastint_to_arr_idx(tv_key);
DUK_DDD(DUK_DDDPRINT("base object string, key is a fast-path fastint; arr_idx %ld", (long) arr_idx));
pop_count = 0;
} else
#endif
if (DUK_TVAL_IS_NUMBER(tv_key)) {
arr_idx = duk__tval_number_to_arr_idx(tv_key);
DUK_DDD(DUK_DDDPRINT("base object string, key is a fast-path number; arr_idx %ld", (long) arr_idx));
pop_count = 0;
} else {
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_DDD(DUK_DDDPRINT("base object string, key is a non-fast-path number; after "
"coercion key is %!T, arr_idx %ld",
(duk_tval *) duk_get_tval(thr, -1), (long) arr_idx));
pop_count = 1;
}
if (arr_idx != DUK__NO_ARRAY_INDEX &&
arr_idx < DUK_HSTRING_GET_CHARLEN(h)) {
duk_pop_n_unsafe(thr, pop_count);
duk_push_hstring(thr, h);
duk_substring(thr, -1, arr_idx, arr_idx + 1); /* [str] -> [substr] */
DUK_STATS_INC(thr->heap, stats_getprop_stringidx);
DUK_DDD(DUK_DDDPRINT("-> %!T (base is string, key is an index inside string length "
"after coercion -> return char)",
(duk_tval *) duk_get_tval(thr, -1)));
return 1;
}
if (pop_count == 0) {
/* This is a pretty awkward control flow, but we need to recheck the
* key coercion here.
*/
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_DDD(DUK_DDDPRINT("base object string, key is a non-fast-path number; after "
"coercion key is %!T, arr_idx %ld",
(duk_tval *) duk_get_tval(thr, -1), (long) arr_idx));
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
duk_pop_unsafe(thr); /* [key] -> [] */
duk_push_uint(thr, (duk_uint_t) DUK_HSTRING_GET_CHARLEN(h)); /* [] -> [res] */
DUK_STATS_INC(thr->heap, stats_getprop_stringlen);
DUK_DDD(DUK_DDDPRINT("-> %!T (base is string, key is 'length' after coercion -> "
"return string length)",
(duk_tval *) duk_get_tval(thr, -1)));
return 1;
}
DUK_DDD(DUK_DDDPRINT("base object is a string, start lookup from string prototype"));
curr = thr->builtins[DUK_BIDX_STRING_PROTOTYPE];
goto lookup; /* avoid double coercion */
}
case DUK_TAG_OBJECT: {
#if defined(DUK_USE_ARRAY_PROP_FASTPATH)
duk_tval *tmp;
#endif
curr = DUK_TVAL_GET_OBJECT(tv_obj);
DUK_ASSERT(curr != NULL);
/* XXX: array .length fast path (important in e.g. loops)? */
#if defined(DUK_USE_ARRAY_PROP_FASTPATH)
tmp = duk__getprop_shallow_fastpath_array_tval(thr, curr, tv_key);
if (tmp) {
duk_push_tval(thr, tmp);
DUK_DDD(DUK_DDDPRINT("-> %!T (base is object, key is a number, array part "
"fast path)",
(duk_tval *) duk_get_tval(thr, -1)));
DUK_STATS_INC(thr->heap, stats_getprop_arrayidx);
return 1;
}
#endif
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
if (duk__getprop_fastpath_bufobj_tval(thr, curr, tv_key) != 0) {
/* Read value pushed on stack. */
DUK_DDD(DUK_DDDPRINT("-> %!T (base is bufobj, key is a number, bufobj "
"fast path)",
(duk_tval *) duk_get_tval(thr, -1)));
DUK_STATS_INC(thr->heap, stats_getprop_bufobjidx);
return 1;
}
#endif
#if defined(DUK_USE_ES6_PROXY)
if (DUK_UNLIKELY(DUK_HOBJECT_IS_PROXY(curr))) {
duk_hobject *h_target;
if (duk__proxy_check_prop(thr, curr, DUK_STRIDX_GET, tv_key, &h_target)) {
/* -> [ ... trap handler ] */
DUK_DDD(DUK_DDDPRINT("-> proxy object 'get' for key %!T", (duk_tval *) tv_key));
DUK_STATS_INC(thr->heap, stats_getprop_proxy);
duk_push_hobject(thr, h_target); /* target */
duk_push_tval(thr, tv_key); /* P */
duk_push_tval(thr, tv_obj); /* Receiver: Proxy object */
duk_call_method(thr, 3 /*nargs*/);
/* Target object must be checked for a conflicting
* non-configurable property.
*/
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
if (duk__get_own_propdesc_raw(thr, h_target, key, arr_idx, &desc, DUK_GETDESC_FLAG_PUSH_VALUE)) {
duk_tval *tv_hook = duk_require_tval(thr, -3); /* value from hook */
duk_tval *tv_targ = duk_require_tval(thr, -1); /* value from target */
duk_bool_t datadesc_reject;
duk_bool_t accdesc_reject;
DUK_DDD(DUK_DDDPRINT("proxy 'get': target has matching property %!O, check for "
"conflicting property; tv_hook=%!T, tv_targ=%!T, desc.flags=0x%08lx, "
"desc.get=%p, desc.set=%p",
(duk_heaphdr *) key, (duk_tval *) tv_hook, (duk_tval *) tv_targ,
(unsigned long) desc.flags,
(void *) desc.get, (void *) desc.set));
datadesc_reject = !(desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) &&
!(desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) &&
!(desc.flags & DUK_PROPDESC_FLAG_WRITABLE) &&
!duk_js_samevalue(tv_hook, tv_targ);
accdesc_reject = (desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) &&
!(desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) &&
(desc.get == NULL) &&
!DUK_TVAL_IS_UNDEFINED(tv_hook);
if (datadesc_reject || accdesc_reject) {
DUK_ERROR_TYPE(thr, DUK_STR_PROXY_REJECTED);
DUK_WO_NORETURN(return 0;);
}
duk_pop_2_unsafe(thr);
} else {
duk_pop_unsafe(thr);
}
return 1; /* return value */
}
curr = h_target; /* resume lookup from target */
DUK_TVAL_SET_OBJECT(tv_obj, curr);
}
#endif /* DUK_USE_ES6_PROXY */
if (DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(curr)) {
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_STATS_INC(thr->heap, stats_getprop_arguments);
if (duk__check_arguments_map_for_get(thr, curr, key, &desc)) {
DUK_DDD(DUK_DDDPRINT("-> %!T (base is object with arguments exotic behavior, "
"key matches magically bound property -> skip standard "
"Get with replacement value)",
(duk_tval *) duk_get_tval(thr, -1)));
/* no need for 'caller' post-check, because 'key' must be an array index */
duk_remove_m2(thr); /* [key result] -> [result] */
return 1;
}
goto lookup; /* avoid double coercion */
}
break;
}
/* Buffer has virtual properties similar to string, but indexed values
* are numbers, not 1-byte buffers/strings which would perform badly.
*/
case DUK_TAG_BUFFER: {
duk_hbuffer *h = DUK_TVAL_GET_BUFFER(tv_obj);
duk_int_t pop_count;
/*
* Because buffer values are often looped over, a number fast path
* is important.
*/
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
arr_idx = duk__tval_fastint_to_arr_idx(tv_key);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a fast-path fastint; arr_idx %ld", (long) arr_idx));
pop_count = 0;
}
else
#endif
if (DUK_TVAL_IS_NUMBER(tv_key)) {
arr_idx = duk__tval_number_to_arr_idx(tv_key);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a fast-path number; arr_idx %ld", (long) arr_idx));
pop_count = 0;
} else {
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a non-fast-path number; after "
"coercion key is %!T, arr_idx %ld",
(duk_tval *) duk_get_tval(thr, -1), (long) arr_idx));
pop_count = 1;
}
if (arr_idx != DUK__NO_ARRAY_INDEX &&
arr_idx < DUK_HBUFFER_GET_SIZE(h)) {
duk_pop_n_unsafe(thr, pop_count);
duk_push_uint(thr, ((duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h))[arr_idx]);
DUK_STATS_INC(thr->heap, stats_getprop_bufferidx);
DUK_DDD(DUK_DDDPRINT("-> %!T (base is buffer, key is an index inside buffer length "
"after coercion -> return byte as number)",
(duk_tval *) duk_get_tval(thr, -1)));
return 1;
}
if (pop_count == 0) {
/* This is a pretty awkward control flow, but we need to recheck the
* key coercion here.
*/
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a non-fast-path number; after "
"coercion key is %!T, arr_idx %ld",
(duk_tval *) duk_get_tval(thr, -1), (long) arr_idx));
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
duk_pop_unsafe(thr); /* [key] -> [] */
duk_push_uint(thr, (duk_uint_t) DUK_HBUFFER_GET_SIZE(h)); /* [] -> [res] */
DUK_STATS_INC(thr->heap, stats_getprop_bufferlen);
DUK_DDD(DUK_DDDPRINT("-> %!T (base is buffer, key is 'length' "
"after coercion -> return buffer length)",
(duk_tval *) duk_get_tval(thr, -1)));
return 1;
}
DUK_DDD(DUK_DDDPRINT("base object is a buffer, start lookup from Uint8Array prototype"));
curr = thr->builtins[DUK_BIDX_UINT8ARRAY_PROTOTYPE];
goto lookup; /* avoid double coercion */
}
case DUK_TAG_POINTER: {
DUK_DDD(DUK_DDDPRINT("base object is a pointer, start lookup from pointer prototype"));
curr = thr->builtins[DUK_BIDX_POINTER_PROTOTYPE];
break;
}
case DUK_TAG_LIGHTFUNC: {
/* Lightfuncs inherit getter .name and .length from %NativeFunctionPrototype%. */
DUK_DDD(DUK_DDDPRINT("base object is a lightfunc, start lookup from function prototype"));
curr = thr->builtins[DUK_BIDX_NATIVE_FUNCTION_PROTOTYPE];
break;
}
#if defined(DUK_USE_FASTINT)
case DUK_TAG_FASTINT:
#endif
default: {
/* number */
DUK_DDD(DUK_DDDPRINT("base object is a number, start lookup from number prototype"));
DUK_ASSERT(!DUK_TVAL_IS_UNUSED(tv_obj));
DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv_obj));
curr = thr->builtins[DUK_BIDX_NUMBER_PROTOTYPE];
break;
}
}
/* key coercion (unless already coerced above) */
DUK_ASSERT(key == NULL);
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
/*
* Property lookup
*/
lookup:
/* [key] (coerced) */
DUK_ASSERT(curr != NULL);
DUK_ASSERT(key != NULL);
sanity = DUK_HOBJECT_PROTOTYPE_CHAIN_SANITY;
do {
if (!duk__get_own_propdesc_raw(thr, curr, key, arr_idx, &desc, DUK_GETDESC_FLAG_PUSH_VALUE)) {
goto next_in_chain;
}
if (desc.get != NULL) {
/* accessor with defined getter */
DUK_ASSERT((desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) != 0);
duk_pop_unsafe(thr); /* [key undefined] -> [key] */
duk_push_hobject(thr, desc.get);
duk_push_tval(thr, tv_obj); /* note: original, uncoerced base */
#if defined(DUK_USE_NONSTD_GETTER_KEY_ARGUMENT)
duk_dup_m3(thr);
duk_call_method(thr, 1); /* [key getter this key] -> [key retval] */
#else
duk_call_method(thr, 0); /* [key getter this] -> [key retval] */
#endif
} else {
/* [key value] or [key undefined] */
/* data property or accessor without getter */
DUK_ASSERT(((desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) == 0) ||
(desc.get == NULL));
/* if accessor without getter, return value is undefined */
DUK_ASSERT(((desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) == 0) ||
duk_is_undefined(thr, -1));
/* Note: for an accessor without getter, falling through to
* check for "caller" exotic behavior is unnecessary as
* "undefined" will never activate the behavior. But it does
* no harm, so we'll do it anyway.
*/
}
goto found; /* [key result] */
next_in_chain:
/* XXX: option to pretend property doesn't exist if sanity limit is
* hit might be useful.
*/
if (DUK_UNLIKELY(sanity-- == 0)) {
DUK_ERROR_RANGE(thr, DUK_STR_PROTOTYPE_CHAIN_LIMIT);
DUK_WO_NORETURN(return 0;);
}
curr = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, curr);
} while (curr != NULL);
/*
* Not found
*/
duk_to_undefined(thr, -1); /* [key] -> [undefined] (default value) */
DUK_DDD(DUK_DDDPRINT("-> %!T (not found)", (duk_tval *) duk_get_tval(thr, -1)));
return 0;
/*
* Found; post-processing (Function and arguments objects)
*/
found:
/* [key result] */
#if !defined(DUK_USE_NONSTD_FUNC_CALLER_PROPERTY)
/* Special behavior for 'caller' property of (non-bound) function objects
* and non-strict Arguments objects: if 'caller' -value- (!) is a strict
* mode function, throw a TypeError (E5 Sections 15.3.5.4, 10.6).
* Quite interestingly, a non-strict function with no formal arguments
* will get an arguments object -without- special 'caller' behavior!
*
* The E5.1 spec is a bit ambiguous if this special behavior applies when
* a bound function is the base value (not the 'caller' value): Section
* 15.3.4.5 (describing bind()) states that [[Get]] for bound functions
* matches that of Section 15.3.5.4 ([[Get]] for Function instances).
* However, Section 13.3.5.4 has "NOTE: Function objects created using
* Function.prototype.bind use the default [[Get]] internal method."
* The current implementation assumes this means that bound functions
* should not have the special [[Get]] behavior.
*
* The E5.1 spec is also a bit unclear if the TypeError throwing is
* applied if the 'caller' value is a strict bound function. The
* current implementation will throw even for both strict non-bound
* and strict bound functions.
*
* See test-dev-strict-func-as-caller-prop-value.js for quite extensive
* tests.
*
* This exotic behavior is disabled when the non-standard 'caller' property
* is enabled, as it conflicts with the free use of 'caller'.
*/
if (key == DUK_HTHREAD_STRING_CALLER(thr) &&
DUK_TVAL_IS_OBJECT(tv_obj)) {
duk_hobject *orig = DUK_TVAL_GET_OBJECT(tv_obj);
DUK_ASSERT(orig != NULL);
if (DUK_HOBJECT_IS_NONBOUND_FUNCTION(orig) ||
DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(orig)) {
duk_hobject *h;
/* XXX: The TypeError is currently not applied to bound
* functions because the 'strict' flag is not copied by
* bind(). This may or may not be correct, the specification
* only refers to the value being a "strict mode Function
* object" which is ambiguous.
*/
DUK_ASSERT(!DUK_HOBJECT_HAS_BOUNDFUNC(orig));
h = duk_get_hobject(thr, -1); /* NULL if not an object */
if (h &&
DUK_HOBJECT_IS_FUNCTION(h) &&
DUK_HOBJECT_HAS_STRICT(h)) {
/* XXX: sufficient to check 'strict', assert for 'is function' */
DUK_ERROR_TYPE(thr, DUK_STR_STRICT_CALLER_READ);
DUK_WO_NORETURN(return 0;);
}
}
}
#endif /* !DUK_USE_NONSTD_FUNC_CALLER_PROPERTY */
duk_remove_m2(thr); /* [key result] -> [result] */
DUK_DDD(DUK_DDDPRINT("-> %!T (found)", (duk_tval *) duk_get_tval(thr, -1)));
return 1;
}
/*
* HASPROP: ECMAScript property existence check ("in" operator).
*
* Interestingly, the 'in' operator does not do any coercion of
* the target object.
*/
DUK_INTERNAL duk_bool_t duk_hobject_hasprop(duk_hthread *thr, duk_tval *tv_obj, duk_tval *tv_key) {
duk_tval tv_key_copy;
duk_hobject *obj;
duk_hstring *key;
duk_uint32_t arr_idx;
duk_bool_t rc;
duk_propdesc desc;
DUK_DDD(DUK_DDDPRINT("hasprop: thr=%p, obj=%p, key=%p (obj -> %!T, key -> %!T)",
(void *) thr, (void *) tv_obj, (void *) tv_key,
(duk_tval *) tv_obj, (duk_tval *) tv_key));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(tv_obj != NULL);
DUK_ASSERT(tv_key != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_TVAL_SET_TVAL(&tv_key_copy, tv_key);
tv_key = &tv_key_copy;
/*
* The 'in' operator requires an object as its right hand side,
* throwing a TypeError unconditionally if this is not the case.
*
* However, lightfuncs need to behave like fully fledged objects
* here to be maximally transparent, so we need to handle them
* here. Same goes for plain buffers which behave like ArrayBuffers.
*/
/* XXX: Refactor key coercion so that it's only called once. It can't
* be trivially lifted here because the object must be type checked
* first.
*/
if (DUK_TVAL_IS_OBJECT(tv_obj)) {
obj = DUK_TVAL_GET_OBJECT(tv_obj);
DUK_ASSERT(obj != NULL);
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
} else if (DUK_TVAL_IS_BUFFER(tv_obj)) {
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
if (duk__key_is_plain_buf_ownprop(thr, DUK_TVAL_GET_BUFFER(tv_obj), key, arr_idx)) {
rc = 1;
goto pop_and_return;
}
obj = thr->builtins[DUK_BIDX_UINT8ARRAY_PROTOTYPE];
} else if (DUK_TVAL_IS_LIGHTFUNC(tv_obj)) {
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
/* If not found, resume existence check from %NativeFunctionPrototype%.
* We can just substitute the value in this case; nothing will
* need the original base value (as would be the case with e.g.
* setters/getters.
*/
obj = thr->builtins[DUK_BIDX_NATIVE_FUNCTION_PROTOTYPE];
} else {
/* Note: unconditional throw */
DUK_DDD(DUK_DDDPRINT("base object is not an object -> reject"));
DUK_ERROR_TYPE(thr, DUK_STR_INVALID_BASE);
DUK_WO_NORETURN(return 0;);
}
/* XXX: fast path for arrays? */
DUK_ASSERT(key != NULL);
DUK_ASSERT(obj != NULL);
DUK_UNREF(arr_idx);
#if defined(DUK_USE_ES6_PROXY)
if (DUK_UNLIKELY(DUK_HOBJECT_IS_PROXY(obj))) {
duk_hobject *h_target;
duk_bool_t tmp_bool;
/* XXX: the key in 'key in obj' is string coerced before we're called
* (which is the required behavior in E5/E5.1/E6) so the key is a string
* here already.
*/
if (duk__proxy_check_prop(thr, obj, DUK_STRIDX_HAS, tv_key, &h_target)) {
/* [ ... key trap handler ] */
DUK_DDD(DUK_DDDPRINT("-> proxy object 'has' for key %!T", (duk_tval *) tv_key));
duk_push_hobject(thr, h_target); /* target */
duk_push_tval(thr, tv_key); /* P */
duk_call_method(thr, 2 /*nargs*/);
tmp_bool = duk_to_boolean_top_pop(thr);
if (!tmp_bool) {
/* Target object must be checked for a conflicting
* non-configurable property.
*/
if (duk__get_own_propdesc_raw(thr, h_target, key, arr_idx, &desc, 0 /*flags*/)) { /* don't push value */
DUK_DDD(DUK_DDDPRINT("proxy 'has': target has matching property %!O, check for "
"conflicting property; desc.flags=0x%08lx, "
"desc.get=%p, desc.set=%p",
(duk_heaphdr *) key, (unsigned long) desc.flags,
(void *) desc.get, (void *) desc.set));
/* XXX: Extensibility check for target uses IsExtensible(). If we
* implemented the isExtensible trap and didn't reject proxies as
* proxy targets, it should be respected here.
*/
if (!((desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) && /* property is configurable and */
DUK_HOBJECT_HAS_EXTENSIBLE(h_target))) { /* ... target is extensible */
DUK_ERROR_TYPE(thr, DUK_STR_PROXY_REJECTED);
DUK_WO_NORETURN(return 0;);
}
}
}
duk_pop_unsafe(thr); /* [ key ] -> [] */
return tmp_bool;
}
obj = h_target; /* resume check from proxy target */
}
#endif /* DUK_USE_ES6_PROXY */
/* XXX: inline into a prototype walking loop? */
rc = duk__get_propdesc(thr, obj, key, &desc, 0 /*flags*/); /* don't push value */
/* fall through */
pop_and_return:
duk_pop_unsafe(thr); /* [ key ] -> [] */
return rc;
}
/*
* HASPROP variant used internally.
*
* This primitive must never throw an error, callers rely on this.
* In particular, don't throw an error for prototype loops; instead,
* pretend like the property doesn't exist if a prototype sanity limit
* is reached.
*
* Does not implement proxy behavior: if applied to a proxy object,
* returns key existence on the proxy object itself.
*/
DUK_INTERNAL duk_bool_t duk_hobject_hasprop_raw(duk_hthread *thr, duk_hobject *obj, duk_hstring *key) {
duk_propdesc dummy;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
return duk__get_propdesc(thr, obj, key, &dummy, DUK_GETDESC_FLAG_IGNORE_PROTOLOOP); /* don't push value */
}
/*
* Helper: handle Array object 'length' write which automatically
* deletes properties, see E5 Section 15.4.5.1, step 3. This is
* quite tricky to get right.
*
* Used by duk_hobject_putprop().
*/
/* Coerce a new .length candidate to a number and check that it's a valid
* .length.
*/
DUK_LOCAL duk_uint32_t duk__to_new_array_length_checked(duk_hthread *thr, duk_tval *tv) {
duk_uint32_t res;
duk_double_t d;
#if !defined(DUK_USE_PREFER_SIZE)
#if defined(DUK_USE_FASTINT)
/* When fastints are enabled, the most interesting case is assigning
* a fastint to .length (e.g. arr.length = 0).
*/
if (DUK_TVAL_IS_FASTINT(tv)) {
/* Very common case. */
duk_int64_t fi;
fi = DUK_TVAL_GET_FASTINT(tv);
if (fi < 0 || fi > DUK_I64_CONSTANT(0xffffffff)) {
goto fail_range;
}
return (duk_uint32_t) fi;
}
#else /* DUK_USE_FASTINT */
/* When fastints are not enabled, the most interesting case is any
* number.
*/
if (DUK_TVAL_IS_DOUBLE(tv)) {
d = DUK_TVAL_GET_NUMBER(tv);
}
#endif /* DUK_USE_FASTINT */
else
#endif /* !DUK_USE_PREFER_SIZE */
{
/* In all other cases, and when doing a size optimized build,
* fall back to the comprehensive handler.
*/
d = duk_js_tonumber(thr, tv);
}
/* Refuse to update an Array's 'length' to a value outside the
* 32-bit range. Negative zero is accepted as zero.
*/
res = duk_double_to_uint32_t(d);
if (!duk_double_equals((duk_double_t) res, d)) {
goto fail_range;
}
return res;
fail_range:
DUK_ERROR_RANGE(thr, DUK_STR_INVALID_ARRAY_LENGTH);
DUK_WO_NORETURN(return 0;);
}
/* Delete elements required by a smaller length, taking into account
* potentially non-configurable elements. Returns non-zero if all
* elements could be deleted, and zero if all or some elements could
* not be deleted. Also writes final "target length" to 'out_result_len'.
* This is the length value that should go into the 'length' property
* (must be set by the caller). Never throws an error.
*/
DUK_LOCAL
duk_bool_t duk__handle_put_array_length_smaller(duk_hthread *thr,
duk_hobject *obj,
duk_uint32_t old_len,
duk_uint32_t new_len,
duk_bool_t force_flag,
duk_uint32_t *out_result_len) {
duk_uint32_t target_len;
duk_uint_fast32_t i;
duk_uint32_t arr_idx;
duk_hstring *key;
duk_tval *tv;
duk_bool_t rc;
DUK_DDD(DUK_DDDPRINT("new array length smaller than old (%ld -> %ld), "
"probably need to remove elements",
(long) old_len, (long) new_len));
/*
* New length is smaller than old length, need to delete properties above
* the new length.
*
* If array part exists, this is straightforward: array entries cannot
* be non-configurable so this is guaranteed to work.
*
* If array part does not exist, array-indexed values are scattered
* in the entry part, and some may not be configurable (preventing length
* from becoming lower than their index + 1). To handle the algorithm
* in E5 Section 15.4.5.1, step l correctly, we scan the entire property
* set twice.
*/
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(new_len < old_len);
DUK_ASSERT(out_result_len != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_ASSERT(DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj));
DUK_ASSERT(DUK_HOBJECT_IS_ARRAY(obj));
if (DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
/*
* All defined array-indexed properties are in the array part
* (we assume the array part is comprehensive), and all array
* entries are writable, configurable, and enumerable. Thus,
* nothing can prevent array entries from being deleted.
*/
DUK_DDD(DUK_DDDPRINT("have array part, easy case"));
if (old_len < DUK_HOBJECT_GET_ASIZE(obj)) {
/* XXX: assertion that entries >= old_len are already unused */
i = old_len;
} else {
i = DUK_HOBJECT_GET_ASIZE(obj);
}
DUK_ASSERT(i <= DUK_HOBJECT_GET_ASIZE(obj));
while (i > new_len) {
i--;
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, i);
DUK_TVAL_SET_UNUSED_UPDREF(thr, tv); /* side effects */
}
*out_result_len = new_len;
return 1;
} else {
/*
* Entries part is a bit more complex.
*/
/* Stage 1: find highest preventing non-configurable entry (if any).
* When forcing, ignore non-configurability.
*/
DUK_DDD(DUK_DDDPRINT("no array part, slow case"));
DUK_DDD(DUK_DDDPRINT("array length write, no array part, stage 1: find target_len "
"(highest preventing non-configurable entry (if any))"));
target_len = new_len;
if (force_flag) {
DUK_DDD(DUK_DDDPRINT("array length write, no array part; force flag -> skip stage 1"));
goto skip_stage1;
}
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
key = DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i);
if (!key) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: null key", (long) i));
continue;
}
if (!DUK_HSTRING_HAS_ARRIDX(key)) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: key not an array index", (long) i));
continue;
}
DUK_ASSERT(DUK_HSTRING_HAS_ARRIDX(key)); /* XXX: macro checks for array index flag, which is unnecessary here */
arr_idx = DUK_HSTRING_GET_ARRIDX_SLOW(key);
DUK_ASSERT(arr_idx != DUK__NO_ARRAY_INDEX);
DUK_ASSERT(arr_idx < old_len); /* consistency requires this */
if (arr_idx < new_len) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: key is array index %ld, below new_len",
(long) i, (long) arr_idx));
continue;
}
if (DUK_HOBJECT_E_SLOT_IS_CONFIGURABLE(thr->heap, obj, i)) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: key is a relevant array index %ld, but configurable",
(long) i, (long) arr_idx));
continue;
}
/* relevant array index is non-configurable, blocks write */
if (arr_idx >= target_len) {
DUK_DDD(DUK_DDDPRINT("entry at index %ld has arr_idx %ld, is not configurable, "
"update target_len %ld -> %ld",
(long) i, (long) arr_idx, (long) target_len,
(long) (arr_idx + 1)));
target_len = arr_idx + 1;
}
}
skip_stage1:
/* stage 2: delete configurable entries above target length */
DUK_DDD(DUK_DDDPRINT("old_len=%ld, new_len=%ld, target_len=%ld",
(long) old_len, (long) new_len, (long) target_len));
DUK_DDD(DUK_DDDPRINT("array length write, no array part, stage 2: remove "
"entries >= target_len"));
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
key = DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i);
if (!key) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: null key", (long) i));
continue;
}
if (!DUK_HSTRING_HAS_ARRIDX(key)) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: key not an array index", (long) i));
continue;
}
DUK_ASSERT(DUK_HSTRING_HAS_ARRIDX(key)); /* XXX: macro checks for array index flag, which is unnecessary here */
arr_idx = DUK_HSTRING_GET_ARRIDX_SLOW(key);
DUK_ASSERT(arr_idx != DUK__NO_ARRAY_INDEX);
DUK_ASSERT(arr_idx < old_len); /* consistency requires this */
if (arr_idx < target_len) {
DUK_DDD(DUK_DDDPRINT("skip entry index %ld: key is array index %ld, below target_len",
(long) i, (long) arr_idx));
continue;
}
DUK_ASSERT(force_flag || DUK_HOBJECT_E_SLOT_IS_CONFIGURABLE(thr->heap, obj, i)); /* stage 1 guarantees */
DUK_DDD(DUK_DDDPRINT("delete entry index %ld: key is array index %ld",
(long) i, (long) arr_idx));
/*
* Slow delete, but we don't care as we're already in a very slow path.
* The delete always succeeds: key has no exotic behavior, property
* is configurable, and no resize occurs.
*/
rc = duk_hobject_delprop_raw(thr, obj, key, force_flag ? DUK_DELPROP_FLAG_FORCE : 0);
DUK_UNREF(rc);
DUK_ASSERT(rc != 0);
}
/* stage 3: update length (done by caller), decide return code */
DUK_DDD(DUK_DDDPRINT("array length write, no array part, stage 3: update length (done by caller)"));
*out_result_len = target_len;
if (target_len == new_len) {
DUK_DDD(DUK_DDDPRINT("target_len matches new_len, return success"));
return 1;
}
DUK_DDD(DUK_DDDPRINT("target_len does not match new_len (some entry prevented "
"full length adjustment), return error"));
return 0;
}
DUK_UNREACHABLE();
}
/* XXX: is valstack top best place for argument? */
DUK_LOCAL duk_bool_t duk__handle_put_array_length(duk_hthread *thr, duk_hobject *obj) {
duk_harray *a;
duk_uint32_t old_len;
duk_uint32_t new_len;
duk_uint32_t result_len;
duk_bool_t rc;
DUK_DDD(DUK_DDDPRINT("handling a put operation to array 'length' exotic property, "
"new val: %!T",
(duk_tval *) duk_get_tval(thr, -1)));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_ASSERT(DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj));
DUK_ASSERT(DUK_HOBJECT_IS_ARRAY(obj));
a = (duk_harray *) obj;
DUK_HARRAY_ASSERT_VALID(a);
DUK_ASSERT(duk_is_valid_index(thr, -1));
/*
* Get old and new length
*/
old_len = a->length;
new_len = duk__to_new_array_length_checked(thr, DUK_GET_TVAL_NEGIDX(thr, -1));
DUK_DDD(DUK_DDDPRINT("old_len=%ld, new_len=%ld", (long) old_len, (long) new_len));
/*
* Writability check
*/
if (DUK_HARRAY_LENGTH_NONWRITABLE(a)) {
DUK_DDD(DUK_DDDPRINT("length is not writable, fail"));
return 0;
}
/*
* New length not lower than old length => no changes needed
* (not even array allocation).
*/
if (new_len >= old_len) {
DUK_DDD(DUK_DDDPRINT("new length is same or higher than old length, just update length, no deletions"));
a->length = new_len;
return 1;
}
DUK_DDD(DUK_DDDPRINT("new length is lower than old length, probably must delete entries"));
/*
* New length lower than old length => delete elements, then
* update length.
*
* Note: even though a bunch of elements have been deleted, the 'desc' is
* still valid as properties haven't been resized (and entries compacted).
*/
rc = duk__handle_put_array_length_smaller(thr, obj, old_len, new_len, 0 /*force_flag*/, &result_len);
DUK_ASSERT(result_len >= new_len && result_len <= old_len);
a->length = result_len;
/* XXX: shrink array allocation or entries compaction here? */
return rc;
}
/*
* PUTPROP: ECMAScript property write.
*
* Unlike ECMAScript primitive which returns nothing, returns 1 to indicate
* success and 0 to indicate failure (assuming throw is not set).
*
* This is an extremely tricky function. Some examples:
*
* * Currently a decref may trigger a GC, which may compact an object's
* property allocation. Consequently, any entry indices (e_idx) will
* be potentially invalidated by a decref.
*
* * Exotic behaviors (strings, arrays, arguments object) require,
* among other things:
*
* - Preprocessing before and postprocessing after an actual property
* write. For example, array index write requires pre-checking the
* array 'length' property for access control, and may require an
* array 'length' update after the actual write has succeeded (but
* not if it fails).
*
* - Deletion of multiple entries, as a result of array 'length' write.
*
* * Input values are taken as pointers which may point to the valstack.
* If valstack is resized because of the put (this may happen at least
* when the array part is abandoned), the pointers can be invalidated.
* (We currently make a copy of all of the input values to avoid issues.)
*/
DUK_INTERNAL duk_bool_t duk_hobject_putprop(duk_hthread *thr, duk_tval *tv_obj, duk_tval *tv_key, duk_tval *tv_val, duk_bool_t throw_flag) {
duk_tval tv_obj_copy;
duk_tval tv_key_copy;
duk_tval tv_val_copy;
duk_hobject *orig = NULL; /* NULL if tv_obj is primitive */
duk_hobject *curr;
duk_hstring *key = NULL;
duk_propdesc desc;
duk_tval *tv;
duk_uint32_t arr_idx;
duk_bool_t rc;
duk_int_t e_idx;
duk_uint_t sanity;
duk_uint32_t new_array_length = 0; /* 0 = no update */
DUK_DDD(DUK_DDDPRINT("putprop: thr=%p, obj=%p, key=%p, val=%p, throw=%ld "
"(obj -> %!T, key -> %!T, val -> %!T)",
(void *) thr, (void *) tv_obj, (void *) tv_key, (void *) tv_val,
(long) throw_flag, (duk_tval *) tv_obj, (duk_tval *) tv_key, (duk_tval *) tv_val));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(tv_obj != NULL);
DUK_ASSERT(tv_key != NULL);
DUK_ASSERT(tv_val != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_STATS_INC(thr->heap, stats_putprop_all);
/*
* Make a copy of tv_obj, tv_key, and tv_val to avoid any issues of
* them being invalidated by a valstack resize.
*
* XXX: this is an overkill for some paths, so optimize this later
* (or maybe switch to a stack arguments model entirely).
*/
DUK_TVAL_SET_TVAL(&tv_obj_copy, tv_obj);
DUK_TVAL_SET_TVAL(&tv_key_copy, tv_key);
DUK_TVAL_SET_TVAL(&tv_val_copy, tv_val);
tv_obj = &tv_obj_copy;
tv_key = &tv_key_copy;
tv_val = &tv_val_copy;
/*
* Coercion and fast path processing.
*/
switch (DUK_TVAL_GET_TAG(tv_obj)) {
case DUK_TAG_UNDEFINED:
case DUK_TAG_NULL: {
/* Note: unconditional throw */
DUK_DDD(DUK_DDDPRINT("base object is undefined or null -> reject (object=%!iT)",
(duk_tval *) tv_obj));
#if defined(DUK_USE_PARANOID_ERRORS)
DUK_ERROR_TYPE(thr, DUK_STR_INVALID_BASE);
#else
DUK_ERROR_FMT2(thr, DUK_ERR_TYPE_ERROR, "cannot write property %s of %s",
duk_push_string_tval_readable(thr, tv_key), duk_push_string_tval_readable(thr, tv_obj));
#endif
DUK_WO_NORETURN(return 0;);
break;
}
case DUK_TAG_BOOLEAN: {
DUK_DDD(DUK_DDDPRINT("base object is a boolean, start lookup from boolean prototype"));
curr = thr->builtins[DUK_BIDX_BOOLEAN_PROTOTYPE];
break;
}
case DUK_TAG_STRING: {
duk_hstring *h = DUK_TVAL_GET_STRING(tv_obj);
/*
* Note: currently no fast path for array index writes.
* They won't be possible anyway as strings are immutable.
*/
DUK_ASSERT(key == NULL);
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
if (DUK_UNLIKELY(DUK_HSTRING_HAS_SYMBOL(h))) {
/* Symbols (ES2015 or hidden) don't have virtual properties. */
curr = thr->builtins[DUK_BIDX_SYMBOL_PROTOTYPE];
goto lookup;
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
goto fail_not_writable;
}
if (arr_idx != DUK__NO_ARRAY_INDEX &&
arr_idx < DUK_HSTRING_GET_CHARLEN(h)) {
goto fail_not_writable;
}
DUK_DDD(DUK_DDDPRINT("base object is a string, start lookup from string prototype"));
curr = thr->builtins[DUK_BIDX_STRING_PROTOTYPE];
goto lookup; /* avoid double coercion */
}
case DUK_TAG_OBJECT: {
orig = DUK_TVAL_GET_OBJECT(tv_obj);
DUK_ASSERT(orig != NULL);
#if defined(DUK_USE_ROM_OBJECTS)
/* With this check in place fast paths won't need read-only
* object checks. This is technically incorrect if there are
* setters that cause no writes to ROM objects, but current
* built-ins don't have such setters.
*/
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) orig)) {
DUK_DD(DUK_DDPRINT("attempt to putprop on read-only target object"));
goto fail_not_writable_no_pop; /* Must avoid duk_pop() in exit path */
}
#endif
/* The fast path for array property put is not fully compliant:
* If one places conflicting number-indexed properties into
* Array.prototype (for example, a non-writable Array.prototype[7])
* the fast path will incorrectly ignore them.
*
* This fast path could be made compliant by falling through
* to the slow path if the previous value was UNUSED. This would
* also remove the need to check for extensibility. Right now a
* non-extensible array is slower than an extensible one as far
* as writes are concerned.
*
* The fast path behavior is documented in more detail here:
* tests/ecmascript/test-misc-array-fast-write.js
*/
/* XXX: array .length? */
#if defined(DUK_USE_ARRAY_PROP_FASTPATH)
if (duk__putprop_shallow_fastpath_array_tval(thr, orig, tv_key, tv_val) != 0) {
DUK_DDD(DUK_DDDPRINT("array fast path success"));
DUK_STATS_INC(thr->heap, stats_putprop_arrayidx);
return 1;
}
#endif
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
if (duk__putprop_fastpath_bufobj_tval(thr, orig, tv_key, tv_val) != 0) {
DUK_DDD(DUK_DDDPRINT("base is bufobj, key is a number, bufobj fast path"));
DUK_STATS_INC(thr->heap, stats_putprop_bufobjidx);
return 1;
}
#endif
#if defined(DUK_USE_ES6_PROXY)
if (DUK_UNLIKELY(DUK_HOBJECT_IS_PROXY(orig))) {
duk_hobject *h_target;
duk_bool_t tmp_bool;
if (duk__proxy_check_prop(thr, orig, DUK_STRIDX_SET, tv_key, &h_target)) {
/* -> [ ... trap handler ] */
DUK_DDD(DUK_DDDPRINT("-> proxy object 'set' for key %!T", (duk_tval *) tv_key));
DUK_STATS_INC(thr->heap, stats_putprop_proxy);
duk_push_hobject(thr, h_target); /* target */
duk_push_tval(thr, tv_key); /* P */
duk_push_tval(thr, tv_val); /* V */
duk_push_tval(thr, tv_obj); /* Receiver: Proxy object */
duk_call_method(thr, 4 /*nargs*/);
tmp_bool = duk_to_boolean_top_pop(thr);
if (!tmp_bool) {
goto fail_proxy_rejected;
}
/* Target object must be checked for a conflicting
* non-configurable property.
*/
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
if (duk__get_own_propdesc_raw(thr, h_target, key, arr_idx, &desc, DUK_GETDESC_FLAG_PUSH_VALUE)) {
duk_tval *tv_targ = duk_require_tval(thr, -1);
duk_bool_t datadesc_reject;
duk_bool_t accdesc_reject;
DUK_DDD(DUK_DDDPRINT("proxy 'set': target has matching property %!O, check for "
"conflicting property; tv_val=%!T, tv_targ=%!T, desc.flags=0x%08lx, "
"desc.get=%p, desc.set=%p",
(duk_heaphdr *) key, (duk_tval *) tv_val, (duk_tval *) tv_targ,
(unsigned long) desc.flags,
(void *) desc.get, (void *) desc.set));
datadesc_reject = !(desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) &&
!(desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) &&
!(desc.flags & DUK_PROPDESC_FLAG_WRITABLE) &&
!duk_js_samevalue(tv_val, tv_targ);
accdesc_reject = (desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) &&
!(desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) &&
(desc.set == NULL);
if (datadesc_reject || accdesc_reject) {
DUK_ERROR_TYPE(thr, DUK_STR_PROXY_REJECTED);
DUK_WO_NORETURN(return 0;);
}
duk_pop_2_unsafe(thr);
} else {
duk_pop_unsafe(thr);
}
return 1; /* success */
}
orig = h_target; /* resume write to target */
DUK_TVAL_SET_OBJECT(tv_obj, orig);
}
#endif /* DUK_USE_ES6_PROXY */
curr = orig;
break;
}
case DUK_TAG_BUFFER: {
duk_hbuffer *h = DUK_TVAL_GET_BUFFER(tv_obj);
duk_int_t pop_count = 0;
/*
* Because buffer values may be looped over and read/written
* from, an array index fast path is important.
*/
#if defined(DUK_USE_FASTINT)
if (DUK_TVAL_IS_FASTINT(tv_key)) {
arr_idx = duk__tval_fastint_to_arr_idx(tv_key);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a fast-path fastint; arr_idx %ld", (long) arr_idx));
pop_count = 0;
} else
#endif
if (DUK_TVAL_IS_NUMBER(tv_key)) {
arr_idx = duk__tval_number_to_arr_idx(tv_key);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a fast-path number; arr_idx %ld", (long) arr_idx));
pop_count = 0;
} else {
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a non-fast-path number; after "
"coercion key is %!T, arr_idx %ld",
(duk_tval *) duk_get_tval(thr, -1), (long) arr_idx));
pop_count = 1;
}
if (arr_idx != DUK__NO_ARRAY_INDEX &&
arr_idx < DUK_HBUFFER_GET_SIZE(h)) {
duk_uint8_t *data;
DUK_DDD(DUK_DDDPRINT("writing to buffer data at index %ld", (long) arr_idx));
data = (duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h);
/* XXX: duk_to_int() ensures we'll get 8 lowest bits as
* as input is within duk_int_t range (capped outside it).
*/
#if defined(DUK_USE_FASTINT)
/* Buffer writes are often integers. */
if (DUK_TVAL_IS_FASTINT(tv_val)) {
data[arr_idx] = (duk_uint8_t) DUK_TVAL_GET_FASTINT_U32(tv_val);
}
else
#endif
{
duk_push_tval(thr, tv_val);
data[arr_idx] = (duk_uint8_t) duk_to_uint32(thr, -1);
pop_count++;
}
duk_pop_n_unsafe(thr, pop_count);
DUK_DDD(DUK_DDDPRINT("result: success (buffer data write)"));
DUK_STATS_INC(thr->heap, stats_putprop_bufferidx);
return 1;
}
if (pop_count == 0) {
/* This is a pretty awkward control flow, but we need to recheck the
* key coercion here.
*/
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
DUK_DDD(DUK_DDDPRINT("base object buffer, key is a non-fast-path number; after "
"coercion key is %!T, arr_idx %ld",
(duk_tval *) duk_get_tval(thr, -1), (long) arr_idx));
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
goto fail_not_writable;
}
DUK_DDD(DUK_DDDPRINT("base object is a buffer, start lookup from Uint8Array prototype"));
curr = thr->builtins[DUK_BIDX_UINT8ARRAY_PROTOTYPE];
goto lookup; /* avoid double coercion */
}
case DUK_TAG_POINTER: {
DUK_DDD(DUK_DDDPRINT("base object is a pointer, start lookup from pointer prototype"));
curr = thr->builtins[DUK_BIDX_POINTER_PROTOTYPE];
break;
}
case DUK_TAG_LIGHTFUNC: {
/* Lightfuncs have no own properties and are considered non-extensible.
* However, the write may be captured by an inherited setter which
* means we can't stop the lookup here.
*/
DUK_DDD(DUK_DDDPRINT("base object is a lightfunc, start lookup from function prototype"));
curr = thr->builtins[DUK_BIDX_NATIVE_FUNCTION_PROTOTYPE];
break;
}
#if defined(DUK_USE_FASTINT)
case DUK_TAG_FASTINT:
#endif
default: {
/* number */
DUK_DDD(DUK_DDDPRINT("base object is a number, start lookup from number prototype"));
DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv_obj));
curr = thr->builtins[DUK_BIDX_NUMBER_PROTOTYPE];
break;
}
}
DUK_ASSERT(key == NULL);
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
lookup:
/*
* Check whether the property already exists in the prototype chain.
* Note that the actual write goes into the original base object
* (except if an accessor property captures the write).
*/
/* [key] */
DUK_ASSERT(curr != NULL);
sanity = DUK_HOBJECT_PROTOTYPE_CHAIN_SANITY;
do {
if (!duk__get_own_propdesc_raw(thr, curr, key, arr_idx, &desc, 0 /*flags*/)) { /* don't push value */
goto next_in_chain;
}
if (desc.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
/*
* Found existing accessor property (own or inherited).
* Call setter with 'this' set to orig, and value as the only argument.
* Setter calls are OK even for ROM objects.
*
* Note: no exotic arguments object behavior, because [[Put]] never
* calls [[DefineOwnProperty]] (E5 Section 8.12.5, step 5.b).
*/
duk_hobject *setter;
DUK_DD(DUK_DDPRINT("put to an own or inherited accessor, calling setter"));
setter = DUK_HOBJECT_E_GET_VALUE_SETTER(thr->heap, curr, desc.e_idx);
if (!setter) {
goto fail_no_setter;
}
duk_push_hobject(thr, setter);
duk_push_tval(thr, tv_obj); /* note: original, uncoerced base */
duk_push_tval(thr, tv_val); /* [key setter this val] */
#if defined(DUK_USE_NONSTD_SETTER_KEY_ARGUMENT)
duk_dup_m4(thr);
duk_call_method(thr, 2); /* [key setter this val key] -> [key retval] */
#else
duk_call_method(thr, 1); /* [key setter this val] -> [key retval] */
#endif
duk_pop_unsafe(thr); /* ignore retval -> [key] */
goto success_no_arguments_exotic;
}
if (orig == NULL) {
/*
* Found existing own or inherited plain property, but original
* base is a primitive value.
*/
DUK_DD(DUK_DDPRINT("attempt to create a new property in a primitive base object"));
goto fail_base_primitive;
}
if (curr != orig) {
/*
* Found existing inherited plain property.
* Do an access control check, and if OK, write
* new property to 'orig'.
*/
if (!DUK_HOBJECT_HAS_EXTENSIBLE(orig)) {
DUK_DD(DUK_DDPRINT("found existing inherited plain property, but original object is not extensible"));
goto fail_not_extensible;
}
if (!(desc.flags & DUK_PROPDESC_FLAG_WRITABLE)) {
DUK_DD(DUK_DDPRINT("found existing inherited plain property, original object is extensible, but inherited property is not writable"));
goto fail_not_writable;
}
DUK_DD(DUK_DDPRINT("put to new property, object extensible, inherited property found and is writable"));
goto create_new;
} else {
/*
* Found existing own (non-inherited) plain property.
* Do an access control check and update in place.
*/
if (!(desc.flags & DUK_PROPDESC_FLAG_WRITABLE)) {
DUK_DD(DUK_DDPRINT("found existing own (non-inherited) plain property, but property is not writable"));
goto fail_not_writable;
}
if (desc.flags & DUK_PROPDESC_FLAG_VIRTUAL) {
DUK_DD(DUK_DDPRINT("found existing own (non-inherited) virtual property, property is writable"));
if (DUK_HOBJECT_IS_ARRAY(curr)) {
/*
* Write to 'length' of an array is a very complex case
* handled in a helper which updates both the array elements
* and writes the new 'length'. The write may result in an
* unconditional RangeError or a partial write (indicated
* by a return code).
*
* Note: the helper has an unnecessary writability check
* for 'length', we already know it is writable.
*/
DUK_ASSERT(key == DUK_HTHREAD_STRING_LENGTH(thr)); /* only virtual array property */
DUK_DDD(DUK_DDDPRINT("writing existing 'length' property to array exotic, invoke complex helper"));
/* XXX: the helper currently assumes stack top contains new
* 'length' value and the whole calling convention is not very
* compatible with what we need.
*/
duk_push_tval(thr, tv_val); /* [key val] */
rc = duk__handle_put_array_length(thr, orig);
duk_pop_unsafe(thr); /* [key val] -> [key] */
if (!rc) {
goto fail_array_length_partial;
}
/* key is 'length', cannot match argument exotic behavior */
goto success_no_arguments_exotic;
}
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
else if (DUK_HOBJECT_IS_BUFOBJ(curr)) {
duk_hbufobj *h_bufobj;
duk_uint_t byte_off;
duk_small_uint_t elem_size;
h_bufobj = (duk_hbufobj *) curr;
DUK_HBUFOBJ_ASSERT_VALID(h_bufobj);
DUK_DD(DUK_DDPRINT("writable virtual property is in buffer object"));
/* Careful with wrapping: arr_idx upshift may easily wrap, whereas
* length downshift won't.
*/
if (arr_idx < (h_bufobj->length >> h_bufobj->shift) && DUK_HBUFOBJ_HAS_VIRTUAL_INDICES(h_bufobj)) {
duk_uint8_t *data;
DUK_DDD(DUK_DDDPRINT("writing to buffer data at index %ld", (long) arr_idx));
DUK_ASSERT(arr_idx != DUK__NO_ARRAY_INDEX); /* index/length check guarantees */
byte_off = arr_idx << h_bufobj->shift; /* no wrap assuming h_bufobj->length is valid */
elem_size = (duk_small_uint_t) (1U << h_bufobj->shift);
/* Coerce to number before validating pointers etc so that the
* number coercions in duk_hbufobj_validated_write() are
* guaranteed to be side effect free and not invalidate the
* pointer checks we do here.
*/
duk_push_tval(thr, tv_val);
(void) duk_to_number_m1(thr);
if (h_bufobj->buf != NULL && DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_bufobj, byte_off + elem_size)) {
data = (duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_bufobj->buf) + h_bufobj->offset + byte_off;
duk_hbufobj_validated_write(thr, h_bufobj, data, elem_size);
} else {
DUK_D(DUK_DPRINT("bufobj access out of underlying buffer, ignoring (write skipped)"));
}
duk_pop_unsafe(thr);
goto success_no_arguments_exotic;
}
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
DUK_D(DUK_DPRINT("should not happen, key %!O", key));
goto fail_internal; /* should not happen */
}
DUK_DD(DUK_DDPRINT("put to existing own plain property, property is writable"));
goto update_old;
}
DUK_UNREACHABLE();
next_in_chain:
/* XXX: option to pretend property doesn't exist if sanity limit is
* hit might be useful.
*/
if (DUK_UNLIKELY(sanity-- == 0)) {
DUK_ERROR_RANGE(thr, DUK_STR_PROTOTYPE_CHAIN_LIMIT);
DUK_WO_NORETURN(return 0;);
}
curr = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, curr);
} while (curr != NULL);
/*
* Property not found in prototype chain.
*/
DUK_DDD(DUK_DDDPRINT("property not found in prototype chain"));
if (orig == NULL) {
DUK_DD(DUK_DDPRINT("attempt to create a new property in a primitive base object"));
goto fail_base_primitive;
}
if (!DUK_HOBJECT_HAS_EXTENSIBLE(orig)) {
DUK_DD(DUK_DDPRINT("put to a new property (not found in prototype chain), but original object not extensible"));
goto fail_not_extensible;
}
goto create_new;
update_old:
/*
* Update an existing property of the base object.
*/
/* [key] */
DUK_DDD(DUK_DDDPRINT("update an existing property of the original object"));
DUK_ASSERT(orig != NULL);
#if defined(DUK_USE_ROM_OBJECTS)
/* This should not happen because DUK_TAG_OBJECT case checks
* for this already, but check just in case.
*/
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) orig)) {
goto fail_not_writable;
}
#endif
/* Although there are writable virtual properties (e.g. plain buffer
* and buffer object number indices), they are handled before we come
* here.
*/
DUK_ASSERT((desc.flags & DUK_PROPDESC_FLAG_VIRTUAL) == 0);
DUK_ASSERT(desc.a_idx >= 0 || desc.e_idx >= 0);
/* Array own property .length is handled above. */
DUK_ASSERT(!(DUK_HOBJECT_IS_ARRAY(orig) && key == DUK_HTHREAD_STRING_LENGTH(thr)));
if (desc.e_idx >= 0) {
tv = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, orig, desc.e_idx);
DUK_DDD(DUK_DDDPRINT("previous entry value: %!iT", (duk_tval *) tv));
DUK_TVAL_SET_TVAL_UPDREF(thr, tv, tv_val); /* side effects; e_idx may be invalidated */
/* don't touch property attributes or hash part */
DUK_DD(DUK_DDPRINT("put to an existing entry at index %ld -> new value %!iT",
(long) desc.e_idx, (duk_tval *) tv));
} else {
/* Note: array entries are always writable, so the writability check
* above is pointless for them. The check could be avoided with some
* refactoring but is probably not worth it.
*/
DUK_ASSERT(desc.a_idx >= 0);
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, orig, desc.a_idx);
DUK_DDD(DUK_DDDPRINT("previous array value: %!iT", (duk_tval *) tv));
DUK_TVAL_SET_TVAL_UPDREF(thr, tv, tv_val); /* side effects; a_idx may be invalidated */
DUK_DD(DUK_DDPRINT("put to an existing array entry at index %ld -> new value %!iT",
(long) desc.a_idx, (duk_tval *) tv));
}
/* Regardless of whether property is found in entry or array part,
* it may have arguments exotic behavior (array indices may reside
* in entry part for abandoned / non-existent array parts).
*/
goto success_with_arguments_exotic;
create_new:
/*
* Create a new property in the original object.
*
* Exotic properties need to be reconsidered here from a write
* perspective (not just property attributes perspective).
* However, the property does not exist in the object already,
* so this limits the kind of exotic properties that apply.
*/
/* [key] */
DUK_DDD(DUK_DDDPRINT("create new property to original object"));
DUK_ASSERT(orig != NULL);
/* Array own property .length is handled above. */
DUK_ASSERT(!(DUK_HOBJECT_IS_ARRAY(orig) && key == DUK_HTHREAD_STRING_LENGTH(thr)));
#if defined(DUK_USE_ROM_OBJECTS)
/* This should not happen because DUK_TAG_OBJECT case checks
* for this already, but check just in case.
*/
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) orig)) {
goto fail_not_writable;
}
#endif
/* Not possible because array object 'length' is present
* from its creation and cannot be deleted, and is thus
* caught as an existing property above.
*/
DUK_ASSERT(!(DUK_HOBJECT_HAS_EXOTIC_ARRAY(orig) &&
key == DUK_HTHREAD_STRING_LENGTH(thr)));
if (DUK_HOBJECT_HAS_EXOTIC_ARRAY(orig) &&
arr_idx != DUK__NO_ARRAY_INDEX) {
/* automatic length update */
duk_uint32_t old_len;
duk_harray *a;
a = (duk_harray *) orig;
DUK_HARRAY_ASSERT_VALID(a);
old_len = a->length;
if (arr_idx >= old_len) {
DUK_DDD(DUK_DDDPRINT("write new array entry requires length update "
"(arr_idx=%ld, old_len=%ld)",
(long) arr_idx, (long) old_len));
if (DUK_HARRAY_LENGTH_NONWRITABLE(a)) {
DUK_DD(DUK_DDPRINT("attempt to extend array, but array 'length' is not writable"));
goto fail_not_writable;
}
/* Note: actual update happens once write has been completed
* without error below. The write should always succeed
* from a specification viewpoint, but we may e.g. run out
* of memory. It's safer in this order.
*/
DUK_ASSERT(arr_idx != 0xffffffffUL);
new_array_length = arr_idx + 1; /* flag for later write */
} else {
DUK_DDD(DUK_DDDPRINT("write new array entry does not require length update "
"(arr_idx=%ld, old_len=%ld)",
(long) arr_idx, (long) old_len));
}
}
/* write_to_array_part: */
/*
* Write to array part?
*
* Note: array abandonding requires a property resize which uses
* 'rechecks' valstack for temporaries and may cause any existing
* valstack pointers to be invalidated. To protect against this,
* tv_obj, tv_key, and tv_val are copies of the original inputs.
*/
if (arr_idx != DUK__NO_ARRAY_INDEX && DUK_HOBJECT_HAS_ARRAY_PART(orig)) {
tv = duk__obtain_arridx_slot(thr, arr_idx, orig);
if (tv == NULL) {
DUK_ASSERT(!DUK_HOBJECT_HAS_ARRAY_PART(orig));
goto write_to_entry_part;
}
/* prev value must be unused, no decref */
DUK_ASSERT(DUK_TVAL_IS_UNUSED(tv));
DUK_TVAL_SET_TVAL(tv, tv_val);
DUK_TVAL_INCREF(thr, tv);
DUK_DD(DUK_DDPRINT("put to new array entry: %ld -> %!T",
(long) arr_idx, (duk_tval *) tv));
/* Note: array part values are [[Writable]], [[Enumerable]],
* and [[Configurable]] which matches the required attributes
* here.
*/
goto entry_updated;
}
write_to_entry_part:
/*
* Write to entry part
*/
/* entry allocation updates hash part and increases the key
* refcount; may need a props allocation resize but doesn't
* 'recheck' the valstack.
*/
e_idx = duk__hobject_alloc_entry_checked(thr, orig, key);
DUK_ASSERT(e_idx >= 0);
tv = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, orig, e_idx);
/* prev value can be garbage, no decref */
DUK_TVAL_SET_TVAL(tv, tv_val);
DUK_TVAL_INCREF(thr, tv);
DUK_HOBJECT_E_SET_FLAGS(thr->heap, orig, e_idx, DUK_PROPDESC_FLAGS_WEC);
goto entry_updated;
entry_updated:
/*
* Possible pending array length update, which must only be done
* if the actual entry write succeeded.
*/
if (new_array_length > 0) {
/* Note: zero works as a "no update" marker because the new length
* can never be zero after a new property is written.
*/
DUK_ASSERT(DUK_HOBJECT_HAS_EXOTIC_ARRAY(orig));
DUK_DDD(DUK_DDDPRINT("write successful, pending array length update to: %ld",
(long) new_array_length));
((duk_harray *) orig)->length = new_array_length;
}
/*
* Arguments exotic behavior not possible for new properties: all
* magically bound properties are initially present in the arguments
* object, and if they are deleted, the binding is also removed from
* parameter map.
*/
goto success_no_arguments_exotic;
success_with_arguments_exotic:
/*
* Arguments objects have exotic [[DefineOwnProperty]] which updates
* the internal 'map' of arguments for writes to currently mapped
* arguments. More conretely, writes to mapped arguments generate
* a write to a bound variable.
*
* The [[Put]] algorithm invokes [[DefineOwnProperty]] for existing
* data properties and new properties, but not for existing accessors.
* Hence, in E5 Section 10.6 ([[DefinedOwnProperty]] algorithm), we
* have a Desc with 'Value' (and possibly other properties too), and
* we end up in step 5.b.i.
*/
if (arr_idx != DUK__NO_ARRAY_INDEX &&
DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(orig)) {
/* Note: only numbered indices are relevant, so arr_idx fast reject
* is good (this is valid unless there are more than 4**32-1 arguments).
*/
DUK_DDD(DUK_DDDPRINT("putprop successful, arguments exotic behavior needed"));
/* Note: we can reuse 'desc' here */
/* XXX: top of stack must contain value, which helper doesn't touch,
* rework to use tv_val directly?
*/
duk_push_tval(thr, tv_val);
(void) duk__check_arguments_map_for_put(thr, orig, key, &desc, throw_flag);
duk_pop_unsafe(thr);
}
/* fall thru */
success_no_arguments_exotic:
/* shared exit path now */
DUK_DDD(DUK_DDDPRINT("result: success"));
duk_pop_unsafe(thr); /* remove key */
return 1;
#if defined(DUK_USE_ES6_PROXY)
fail_proxy_rejected:
DUK_DDD(DUK_DDDPRINT("result: error, proxy rejects"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_PROXY_REJECTED);
DUK_WO_NORETURN(return 0;);
}
/* Note: no key on stack */
return 0;
#endif
fail_base_primitive:
DUK_DDD(DUK_DDDPRINT("result: error, base primitive"));
if (throw_flag) {
#if defined(DUK_USE_PARANOID_ERRORS)
DUK_ERROR_TYPE(thr, DUK_STR_INVALID_BASE);
#else
DUK_ERROR_FMT2(thr, DUK_ERR_TYPE_ERROR, "cannot write property %s of %s",
duk_push_string_tval_readable(thr, tv_key), duk_push_string_tval_readable(thr, tv_obj));
#endif
DUK_WO_NORETURN(return 0;);
}
duk_pop_unsafe(thr); /* remove key */
return 0;
fail_not_extensible:
DUK_DDD(DUK_DDDPRINT("result: error, not extensible"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_EXTENSIBLE);
DUK_WO_NORETURN(return 0;);
}
duk_pop_unsafe(thr); /* remove key */
return 0;
fail_not_writable:
DUK_DDD(DUK_DDDPRINT("result: error, not writable"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_WRITABLE);
DUK_WO_NORETURN(return 0;);
}
duk_pop_unsafe(thr); /* remove key */
return 0;
#if defined(DUK_USE_ROM_OBJECTS)
fail_not_writable_no_pop:
DUK_DDD(DUK_DDDPRINT("result: error, not writable"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_WRITABLE);
DUK_WO_NORETURN(return 0;);
}
return 0;
#endif
fail_array_length_partial:
DUK_DD(DUK_DDPRINT("result: error, array length write only partially successful"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
DUK_WO_NORETURN(return 0;);
}
duk_pop_unsafe(thr); /* remove key */
return 0;
fail_no_setter:
DUK_DDD(DUK_DDDPRINT("result: error, accessor property without setter"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_SETTER_UNDEFINED);
DUK_WO_NORETURN(return 0;);
}
duk_pop_unsafe(thr); /* remove key */
return 0;
fail_internal:
DUK_DDD(DUK_DDDPRINT("result: error, internal"));
if (throw_flag) {
DUK_ERROR_INTERNAL(thr);
DUK_WO_NORETURN(return 0;);
}
duk_pop_unsafe(thr); /* remove key */
return 0;
}
/*
* ECMAScript compliant [[Delete]](P, Throw).
*/
DUK_INTERNAL duk_bool_t duk_hobject_delprop_raw(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_small_uint_t flags) {
duk_propdesc desc;
duk_tval *tv;
duk_uint32_t arr_idx;
duk_bool_t throw_flag;
duk_bool_t force_flag;
throw_flag = (flags & DUK_DELPROP_FLAG_THROW);
force_flag = (flags & DUK_DELPROP_FLAG_FORCE);
DUK_DDD(DUK_DDDPRINT("delprop_raw: thr=%p, obj=%p, key=%p, throw=%ld, force=%ld (obj -> %!O, key -> %!O)",
(void *) thr, (void *) obj, (void *) key, (long) throw_flag, (long) force_flag,
(duk_heaphdr *) obj, (duk_heaphdr *) key));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
arr_idx = DUK_HSTRING_GET_ARRIDX_FAST(key);
/* 0 = don't push current value */
if (!duk__get_own_propdesc_raw(thr, obj, key, arr_idx, &desc, 0 /*flags*/)) { /* don't push value */
DUK_DDD(DUK_DDDPRINT("property not found, succeed always"));
goto success;
}
#if defined(DUK_USE_ROM_OBJECTS)
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)) {
DUK_DD(DUK_DDPRINT("attempt to delprop on read-only target object"));
goto fail_not_configurable;
}
#endif
if ((desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) == 0 && !force_flag) {
goto fail_not_configurable;
}
if (desc.a_idx < 0 && desc.e_idx < 0) {
/* Currently there are no deletable virtual properties, but
* with force_flag we might attempt to delete one.
*/
DUK_DD(DUK_DDPRINT("delete failed: property found, force flag, but virtual (and implicitly non-configurable)"));
goto fail_virtual;
}
if (desc.a_idx >= 0) {
DUK_ASSERT(desc.e_idx < 0);
tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, desc.a_idx);
DUK_TVAL_SET_UNUSED_UPDREF(thr, tv); /* side effects */
goto success;
} else {
DUK_ASSERT(desc.a_idx < 0);
/* remove hash entry (no decref) */
#if defined(DUK_USE_HOBJECT_HASH_PART)
if (desc.h_idx >= 0) {
duk_uint32_t *h_base = DUK_HOBJECT_H_GET_BASE(thr->heap, obj);
DUK_DDD(DUK_DDDPRINT("removing hash entry at h_idx %ld", (long) desc.h_idx));
DUK_ASSERT(DUK_HOBJECT_GET_HSIZE(obj) > 0);
DUK_ASSERT((duk_uint32_t) desc.h_idx < DUK_HOBJECT_GET_HSIZE(obj));
h_base[desc.h_idx] = DUK__HASH_DELETED;
} else {
DUK_ASSERT(DUK_HOBJECT_GET_HSIZE(obj) == 0);
}
#else
DUK_ASSERT(DUK_HOBJECT_GET_HSIZE(obj) == 0);
#endif
/* Remove value. This requires multiple writes so avoid side
* effects via no-refzero macros so that e_idx is not
* invalidated.
*/
DUK_DDD(DUK_DDDPRINT("before removing value, e_idx %ld, key %p, key at slot %p",
(long) desc.e_idx, (void *) key, (void *) DUK_HOBJECT_E_GET_KEY(thr->heap, obj, desc.e_idx)));
DUK_DDD(DUK_DDDPRINT("removing value at e_idx %ld", (long) desc.e_idx));
if (DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, desc.e_idx)) {
duk_hobject *tmp;
tmp = DUK_HOBJECT_E_GET_VALUE_GETTER(thr->heap, obj, desc.e_idx);
DUK_HOBJECT_E_SET_VALUE_GETTER(thr->heap, obj, desc.e_idx, NULL);
DUK_UNREF(tmp);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, tmp);
tmp = DUK_HOBJECT_E_GET_VALUE_SETTER(thr->heap, obj, desc.e_idx);
DUK_HOBJECT_E_SET_VALUE_SETTER(thr->heap, obj, desc.e_idx, NULL);
DUK_UNREF(tmp);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, tmp);
} else {
tv = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, desc.e_idx);
DUK_TVAL_SET_UNDEFINED_UPDREF_NORZ(thr, tv);
}
#if 0
/* Not strictly necessary because if key == NULL, flag MUST be ignored. */
DUK_HOBJECT_E_SET_FLAGS(thr->heap, obj, desc.e_idx, 0);
#endif
/* Remove key. */
DUK_DDD(DUK_DDDPRINT("before removing key, e_idx %ld, key %p, key at slot %p",
(long) desc.e_idx, (void *) key, (void *) DUK_HOBJECT_E_GET_KEY(thr->heap, obj, desc.e_idx)));
DUK_DDD(DUK_DDDPRINT("removing key at e_idx %ld", (long) desc.e_idx));
DUK_ASSERT(key == DUK_HOBJECT_E_GET_KEY(thr->heap, obj, desc.e_idx));
DUK_HOBJECT_E_SET_KEY(thr->heap, obj, desc.e_idx, NULL);
DUK_HSTRING_DECREF_NORZ(thr, key);
/* Trigger refzero side effects only when we're done as a
* finalizer might operate on the object and affect the
* e_idx we're supposed to use.
*/
DUK_REFZERO_CHECK_SLOW(thr);
goto success;
}
DUK_UNREACHABLE();
success:
/*
* Argument exotic [[Delete]] behavior (E5 Section 10.6) is
* a post-check, keeping arguments internal 'map' in sync with
* any successful deletes (note that property does not need to
* exist for delete to 'succeed').
*
* Delete key from 'map'. Since 'map' only contains array index
* keys, we can use arr_idx for a fast skip.
*/
DUK_DDD(DUK_DDDPRINT("delete successful, check for arguments exotic behavior"));
if (arr_idx != DUK__NO_ARRAY_INDEX && DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj)) {
/* Note: only numbered indices are relevant, so arr_idx fast reject
* is good (this is valid unless there are more than 4**32-1 arguments).
*/
DUK_DDD(DUK_DDDPRINT("delete successful, arguments exotic behavior needed"));
/* Note: we can reuse 'desc' here */
(void) duk__check_arguments_map_for_delete(thr, obj, key, &desc);
}
DUK_DDD(DUK_DDDPRINT("delete successful"));
return 1;
fail_virtual: /* just use the same "not configurable" error message */
fail_not_configurable:
DUK_DDD(DUK_DDDPRINT("delete failed: property found, not configurable"));
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
DUK_WO_NORETURN(return 0;);
}
return 0;
}
/*
* DELPROP: ECMAScript property deletion.
*/
DUK_INTERNAL duk_bool_t duk_hobject_delprop(duk_hthread *thr, duk_tval *tv_obj, duk_tval *tv_key, duk_bool_t throw_flag) {
duk_hstring *key = NULL;
#if defined(DUK_USE_ES6_PROXY)
duk_propdesc desc;
#endif
duk_int_t entry_top;
duk_uint32_t arr_idx = DUK__NO_ARRAY_INDEX;
duk_bool_t rc;
DUK_DDD(DUK_DDDPRINT("delprop: thr=%p, obj=%p, key=%p (obj -> %!T, key -> %!T)",
(void *) thr, (void *) tv_obj, (void *) tv_key,
(duk_tval *) tv_obj, (duk_tval *) tv_key));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(tv_obj != NULL);
DUK_ASSERT(tv_key != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
/* Storing the entry top is cheaper here to ensure stack is correct at exit,
* as there are several paths out.
*/
entry_top = duk_get_top(thr);
if (DUK_TVAL_IS_UNDEFINED(tv_obj) ||
DUK_TVAL_IS_NULL(tv_obj)) {
DUK_DDD(DUK_DDDPRINT("base object is undefined or null -> reject"));
goto fail_invalid_base_uncond;
}
duk_push_tval(thr, tv_obj);
duk_push_tval(thr, tv_key);
tv_obj = DUK_GET_TVAL_NEGIDX(thr, -2);
if (DUK_TVAL_IS_OBJECT(tv_obj)) {
duk_hobject *obj = DUK_TVAL_GET_OBJECT(tv_obj);
DUK_ASSERT(obj != NULL);
#if defined(DUK_USE_ES6_PROXY)
if (DUK_UNLIKELY(DUK_HOBJECT_IS_PROXY(obj))) {
duk_hobject *h_target;
duk_bool_t tmp_bool;
/* Note: proxy handling must happen before key is string coerced. */
if (duk__proxy_check_prop(thr, obj, DUK_STRIDX_DELETE_PROPERTY, tv_key, &h_target)) {
/* -> [ ... obj key trap handler ] */
DUK_DDD(DUK_DDDPRINT("-> proxy object 'deleteProperty' for key %!T", (duk_tval *) tv_key));
duk_push_hobject(thr, h_target); /* target */
duk_dup_m4(thr); /* P */
duk_call_method(thr, 2 /*nargs*/);
tmp_bool = duk_to_boolean_top_pop(thr);
if (!tmp_bool) {
goto fail_proxy_rejected; /* retval indicates delete failed */
}
/* Target object must be checked for a conflicting
* non-configurable property.
*/
tv_key = DUK_GET_TVAL_NEGIDX(thr, -1);
arr_idx = duk__push_tval_to_property_key(thr, tv_key, &key);
DUK_ASSERT(key != NULL);
if (duk__get_own_propdesc_raw(thr, h_target, key, arr_idx, &desc, 0 /*flags*/)) { /* don't push value */
duk_small_int_t desc_reject;
DUK_DDD(DUK_DDDPRINT("proxy 'deleteProperty': target has matching property %!O, check for "
"conflicting property; desc.flags=0x%08lx, "
"desc.get=%p, desc.set=%p",
(duk_heaphdr *) key, (unsigned long) desc.flags,
(void *) desc.get, (void *) desc.set));
desc_reject = !(desc.flags & DUK_PROPDESC_FLAG_CONFIGURABLE);
if (desc_reject) {
/* unconditional */
DUK_ERROR_TYPE(thr, DUK_STR_PROXY_REJECTED);
DUK_WO_NORETURN(return 0;);
}
}
rc = 1; /* success */
goto done_rc;
}
obj = h_target; /* resume delete to target */
}
#endif /* DUK_USE_ES6_PROXY */
arr_idx = duk__to_property_key(thr, -1, &key);
DUK_ASSERT(key != NULL);
rc = duk_hobject_delprop_raw(thr, obj, key, throw_flag ? DUK_DELPROP_FLAG_THROW : 0);
goto done_rc;
} else if (DUK_TVAL_IS_STRING(tv_obj)) {
/* String has .length and array index virtual properties
* which can't be deleted. No need for a symbol check;
* no offending virtual symbols exist.
*/
/* XXX: unnecessary string coercion for array indices,
* intentional to keep small.
*/
duk_hstring *h = DUK_TVAL_GET_STRING(tv_obj);
DUK_ASSERT(h != NULL);
arr_idx = duk__to_property_key(thr, -1, &key);
DUK_ASSERT(key != NULL);
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
goto fail_not_configurable;
}
if (arr_idx != DUK__NO_ARRAY_INDEX &&
arr_idx < DUK_HSTRING_GET_CHARLEN(h)) {
goto fail_not_configurable;
}
} else if (DUK_TVAL_IS_BUFFER(tv_obj)) {
/* XXX: unnecessary string coercion for array indices,
* intentional to keep small; some overlap with string
* handling.
*/
duk_hbuffer *h = DUK_TVAL_GET_BUFFER(tv_obj);
DUK_ASSERT(h != NULL);
arr_idx = duk__to_property_key(thr, -1, &key);
DUK_ASSERT(key != NULL);
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
goto fail_not_configurable;
}
if (arr_idx != DUK__NO_ARRAY_INDEX &&
arr_idx < DUK_HBUFFER_GET_SIZE(h)) {
goto fail_not_configurable;
}
} else if (DUK_TVAL_IS_LIGHTFUNC(tv_obj)) {
/* Lightfunc has no virtual properties since Duktape 2.2
* so success. Still must coerce key for side effects.
*/
arr_idx = duk__to_property_key(thr, -1, &key);
DUK_ASSERT(key != NULL);
DUK_UNREF(key);
}
/* non-object base, no offending virtual property */
rc = 1;
goto done_rc;
done_rc:
duk_set_top_unsafe(thr, entry_top);
return rc;
fail_invalid_base_uncond:
/* Note: unconditional throw */
DUK_ASSERT(duk_get_top(thr) == entry_top);
#if defined(DUK_USE_PARANOID_ERRORS)
DUK_ERROR_TYPE(thr, DUK_STR_INVALID_BASE);
#else
DUK_ERROR_FMT2(thr, DUK_ERR_TYPE_ERROR, "cannot delete property %s of %s",
duk_push_string_tval_readable(thr, tv_key), duk_push_string_tval_readable(thr, tv_obj));
#endif
DUK_WO_NORETURN(return 0;);
#if defined(DUK_USE_ES6_PROXY)
fail_proxy_rejected:
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_PROXY_REJECTED);
DUK_WO_NORETURN(return 0;);
}
duk_set_top_unsafe(thr, entry_top);
return 0;
#endif
fail_not_configurable:
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
DUK_WO_NORETURN(return 0;);
}
duk_set_top_unsafe(thr, entry_top);
return 0;
}
/*
* Internal helper to define a property with specific flags, ignoring
* normal semantics such as extensibility, write protection etc.
* Overwrites any existing value and attributes unless caller requests
* that value only be updated if it doesn't already exists.
*
* Does not support:
* - virtual properties (error if write attempted)
* - getter/setter properties (error if write attempted)
* - non-default (!= WEC) attributes for array entries (error if attempted)
* - array abandoning: if array part exists, it is always extended
* - array 'length' updating
*
* Stack: [... in_val] -> []
*
* Used for e.g. built-in initialization and environment record
* operations.
*/
DUK_INTERNAL void duk_hobject_define_property_internal(duk_hthread *thr, duk_hobject *obj, duk_hstring *key, duk_small_uint_t flags) {
duk_propdesc desc;
duk_uint32_t arr_idx;
duk_int_t e_idx;
duk_tval *tv1 = NULL;
duk_tval *tv2 = NULL;
duk_small_uint_t propflags = flags & DUK_PROPDESC_FLAGS_MASK; /* mask out flags not actually stored */
DUK_DDD(DUK_DDDPRINT("define new property (internal): thr=%p, obj=%!O, key=%!O, flags=0x%02lx, val=%!T",
(void *) thr, (duk_heaphdr *) obj, (duk_heaphdr *) key,
(unsigned long) flags, (duk_tval *) duk_get_tval(thr, -1)));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj));
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
DUK_ASSERT(duk_is_valid_index(thr, -1)); /* contains value */
arr_idx = DUK_HSTRING_GET_ARRIDX_SLOW(key);
if (duk__get_own_propdesc_raw(thr, obj, key, arr_idx, &desc, 0 /*flags*/)) { /* don't push value */
if (desc.e_idx >= 0) {
if (flags & DUK_PROPDESC_FLAG_NO_OVERWRITE) {
DUK_DDD(DUK_DDDPRINT("property already exists in the entry part -> skip as requested"));
goto pop_exit;
}
DUK_DDD(DUK_DDDPRINT("property already exists in the entry part -> update value and attributes"));
if (DUK_UNLIKELY(DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, desc.e_idx))) {
DUK_D(DUK_DPRINT("existing property is an accessor, not supported"));
goto error_internal;
}
DUK_HOBJECT_E_SET_FLAGS(thr->heap, obj, desc.e_idx, propflags);
tv1 = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, desc.e_idx);
} else if (desc.a_idx >= 0) {
if (flags & DUK_PROPDESC_FLAG_NO_OVERWRITE) {
DUK_DDD(DUK_DDDPRINT("property already exists in the array part -> skip as requested"));
goto pop_exit;
}
DUK_DDD(DUK_DDDPRINT("property already exists in the array part -> update value (assert attributes)"));
if (propflags != DUK_PROPDESC_FLAGS_WEC) {
DUK_D(DUK_DPRINT("existing property in array part, but propflags not WEC (0x%02lx)",
(unsigned long) propflags));
goto error_internal;
}
tv1 = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, desc.a_idx);
} else {
if (flags & DUK_PROPDESC_FLAG_NO_OVERWRITE) {
DUK_DDD(DUK_DDDPRINT("property already exists but is virtual -> skip as requested"));
goto pop_exit;
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr) && DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
duk_uint32_t new_len;
#if defined(DUK_USE_DEBUG)
duk_uint32_t prev_len;
prev_len = ((duk_harray *) obj)->length;
#endif
new_len = duk__to_new_array_length_checked(thr, DUK_GET_TVAL_NEGIDX(thr, -1));
((duk_harray *) obj)->length = new_len;
DUK_DD(DUK_DDPRINT("internal define property for array .length: %ld -> %ld",
(long) prev_len, (long) ((duk_harray *) obj)->length));
goto pop_exit;
}
DUK_DD(DUK_DDPRINT("property already exists but is virtual -> failure"));
goto error_virtual;
}
goto write_value;
}
if (DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
if (arr_idx != DUK__NO_ARRAY_INDEX) {
DUK_DDD(DUK_DDDPRINT("property does not exist, object has array part -> possibly extend array part and write value (assert attributes)"));
DUK_ASSERT(propflags == DUK_PROPDESC_FLAGS_WEC);
tv1 = duk__obtain_arridx_slot(thr, arr_idx, obj);
if (tv1 == NULL) {
DUK_ASSERT(!DUK_HOBJECT_HAS_ARRAY_PART(obj));
goto write_to_entry_part;
}
tv1 = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, arr_idx);
goto write_value;
}
}
write_to_entry_part:
DUK_DDD(DUK_DDDPRINT("property does not exist, object belongs in entry part -> allocate new entry and write value and attributes"));
e_idx = duk__hobject_alloc_entry_checked(thr, obj, key); /* increases key refcount */
DUK_ASSERT(e_idx >= 0);
DUK_HOBJECT_E_SET_FLAGS(thr->heap, obj, e_idx, propflags);
tv1 = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, e_idx);
/* new entry: previous value is garbage; set to undefined to share write_value */
DUK_TVAL_SET_UNDEFINED(tv1);
goto write_value;
write_value:
/* tv1 points to value storage */
tv2 = duk_require_tval(thr, -1); /* late lookup, avoid side effects */
DUK_DDD(DUK_DDDPRINT("writing/updating value: %!T -> %!T",
(duk_tval *) tv1, (duk_tval *) tv2));
DUK_TVAL_SET_TVAL_UPDREF(thr, tv1, tv2); /* side effects */
goto pop_exit;
pop_exit:
duk_pop_unsafe(thr); /* remove in_val */
return;
error_virtual: /* share error message */
error_internal:
DUK_ERROR_INTERNAL(thr);
DUK_WO_NORETURN(return;);
}
/*
* Fast path for defining array indexed values without interning the key.
* This is used by e.g. code for Array prototype and traceback creation so
* must avoid interning.
*/
DUK_INTERNAL void duk_hobject_define_property_internal_arridx(duk_hthread *thr, duk_hobject *obj, duk_uarridx_t arr_idx, duk_small_uint_t flags) {
duk_hstring *key;
duk_tval *tv1, *tv2;
DUK_DDD(DUK_DDDPRINT("define new property (internal) arr_idx fast path: thr=%p, obj=%!O, "
"arr_idx=%ld, flags=0x%02lx, val=%!T",
(void *) thr, obj, (long) arr_idx, (unsigned long) flags,
(duk_tval *) duk_get_tval(thr, -1)));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj));
if (DUK_HOBJECT_HAS_ARRAY_PART(obj) &&
arr_idx != DUK__NO_ARRAY_INDEX &&
flags == DUK_PROPDESC_FLAGS_WEC) {
DUK_ASSERT((flags & DUK_PROPDESC_FLAG_NO_OVERWRITE) == 0); /* covered by comparison */
DUK_DDD(DUK_DDDPRINT("define property to array part (property may or may not exist yet)"));
tv1 = duk__obtain_arridx_slot(thr, arr_idx, obj);
if (tv1 == NULL) {
DUK_ASSERT(!DUK_HOBJECT_HAS_ARRAY_PART(obj));
goto write_slow;
}
tv2 = duk_require_tval(thr, -1);
DUK_TVAL_SET_TVAL_UPDREF(thr, tv1, tv2); /* side effects */
duk_pop_unsafe(thr); /* [ ...val ] -> [ ... ] */
return;
}
write_slow:
DUK_DDD(DUK_DDDPRINT("define property fast path didn't work, use slow path"));
key = duk_push_uint_to_hstring(thr, (duk_uint_t) arr_idx);
DUK_ASSERT(key != NULL);
duk_insert(thr, -2); /* [ ... val key ] -> [ ... key val ] */
duk_hobject_define_property_internal(thr, obj, key, flags);
duk_pop_unsafe(thr); /* [ ... key ] -> [ ... ] */
}
/*
* Internal helpers for managing object 'length'
*/
DUK_INTERNAL duk_size_t duk_hobject_get_length(duk_hthread *thr, duk_hobject *obj) {
duk_double_t val;
DUK_CTX_ASSERT_VALID(thr);
DUK_ASSERT(obj != NULL);
/* Fast path for Arrays. */
if (DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
return ((duk_harray *) obj)->length;
}
/* Slow path, .length can be e.g. accessor, obj can be a Proxy, etc. */
duk_push_hobject(thr, obj);
duk_push_hstring_stridx(thr, DUK_STRIDX_LENGTH);
(void) duk_hobject_getprop(thr,
DUK_GET_TVAL_NEGIDX(thr, -2),
DUK_GET_TVAL_NEGIDX(thr, -1));
val = duk_to_number_m1(thr);
duk_pop_3_unsafe(thr);
/* This isn't part of ECMAScript semantics; return a value within
* duk_size_t range, or 0 otherwise.
*/
if (val >= 0.0 && val <= (duk_double_t) DUK_SIZE_MAX) {
return (duk_size_t) val;
}
return 0;
}
/*
* Fast finalizer check for an object. Walks the prototype chain, checking
* for finalizer presence using DUK_HOBJECT_FLAG_HAVE_FINALIZER which is kept
* in sync with the actual property when setting/removing the finalizer.
*/
#if defined(DUK_USE_HEAPPTR16)
DUK_INTERNAL duk_bool_t duk_hobject_has_finalizer_fast_raw(duk_heap *heap, duk_hobject *obj) {
#else
DUK_INTERNAL duk_bool_t duk_hobject_has_finalizer_fast_raw(duk_hobject *obj) {
#endif
duk_uint_t sanity;
DUK_ASSERT(obj != NULL);
sanity = DUK_HOBJECT_PROTOTYPE_CHAIN_SANITY;
do {
if (DUK_UNLIKELY(DUK_HOBJECT_HAS_HAVE_FINALIZER(obj))) {
return 1;
}
if (DUK_UNLIKELY(sanity-- == 0)) {
DUK_D(DUK_DPRINT("prototype loop when checking for finalizer existence; returning false"));
return 0;
}
#if defined(DUK_USE_HEAPPTR16)
DUK_ASSERT(heap != NULL);
obj = DUK_HOBJECT_GET_PROTOTYPE(heap, obj);
#else
obj = DUK_HOBJECT_GET_PROTOTYPE(NULL, obj); /* 'heap' arg ignored */
#endif
} while (obj != NULL);
return 0;
}
/*
* Object.getOwnPropertyDescriptor() (E5 Sections 15.2.3.3, 8.10.4)
*
* [ ... key ] -> [ ... desc/undefined ]
*/
DUK_INTERNAL void duk_hobject_object_get_own_property_descriptor(duk_hthread *thr, duk_idx_t obj_idx) {
duk_hobject *obj;
duk_hstring *key;
duk_propdesc pd;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
obj = duk_require_hobject_promote_mask(thr, obj_idx, DUK_TYPE_MASK_LIGHTFUNC | DUK_TYPE_MASK_BUFFER);
key = duk_to_property_key_hstring(thr, -1);
DUK_ASSERT(key != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
if (!duk_hobject_get_own_propdesc(thr, obj, key, &pd, DUK_GETDESC_FLAG_PUSH_VALUE)) {
duk_push_undefined(thr);
duk_remove_m2(thr);
return;
}
duk_push_object(thr);
/* [ ... key value desc ] */
if (DUK_PROPDESC_IS_ACCESSOR(&pd)) {
/* If a setter/getter is missing (undefined), the descriptor must
* still have the property present with the value 'undefined'.
*/
if (pd.get) {
duk_push_hobject(thr, pd.get);
} else {
duk_push_undefined(thr);
}
duk_put_prop_stridx_short(thr, -2, DUK_STRIDX_GET);
if (pd.set) {
duk_push_hobject(thr, pd.set);
} else {
duk_push_undefined(thr);
}
duk_put_prop_stridx_short(thr, -2, DUK_STRIDX_SET);
} else {
duk_dup_m2(thr);
duk_put_prop_stridx_short(thr, -2, DUK_STRIDX_VALUE);
duk_push_boolean(thr, DUK_PROPDESC_IS_WRITABLE(&pd));
duk_put_prop_stridx_short(thr, -2, DUK_STRIDX_WRITABLE);
}
duk_push_boolean(thr, DUK_PROPDESC_IS_ENUMERABLE(&pd));
duk_put_prop_stridx_short(thr, -2, DUK_STRIDX_ENUMERABLE);
duk_push_boolean(thr, DUK_PROPDESC_IS_CONFIGURABLE(&pd));
duk_put_prop_stridx_short(thr, -2, DUK_STRIDX_CONFIGURABLE);
/* [ ... key value desc ] */
duk_replace(thr, -3);
duk_pop_unsafe(thr); /* -> [ ... desc ] */
}
/*
* NormalizePropertyDescriptor() related helper.
*
* Internal helper which validates and normalizes a property descriptor
* represented as an ECMAScript object (e.g. argument to defineProperty()).
* The output of this conversion is a set of defprop_flags and possibly
* some values pushed on the value stack to (1) ensure borrowed pointers
* remain valid, and (2) avoid unnecessary pops for footprint reasons.
* Caller must manage stack top carefully because the number of values
* pushed depends on the input property descriptor.
*
* The original descriptor object must not be altered in the process.
*/
/* XXX: very basic optimization -> duk_get_prop_stridx_top */
DUK_INTERNAL
void duk_hobject_prepare_property_descriptor(duk_hthread *thr,
duk_idx_t idx_in,
duk_uint_t *out_defprop_flags,
duk_idx_t *out_idx_value,
duk_hobject **out_getter,
duk_hobject **out_setter) {
duk_idx_t idx_value = -1;
duk_hobject *getter = NULL;
duk_hobject *setter = NULL;
duk_bool_t is_data_desc = 0;
duk_bool_t is_acc_desc = 0;
duk_uint_t defprop_flags = 0;
DUK_ASSERT(out_defprop_flags != NULL);
DUK_ASSERT(out_idx_value != NULL);
DUK_ASSERT(out_getter != NULL);
DUK_ASSERT(out_setter != NULL);
DUK_ASSERT(idx_in <= 0x7fffL); /* short variants would be OK, but not used to avoid shifts */
/* Must be an object, otherwise TypeError (E5.1 Section 8.10.5, step 1). */
idx_in = duk_require_normalize_index(thr, idx_in);
(void) duk_require_hobject(thr, idx_in);
/* The coercion order must match the ToPropertyDescriptor() algorithm
* so that side effects in coercion happen in the correct order.
* (This order also happens to be compatible with duk_def_prop(),
* although it doesn't matter in practice.)
*/
if (duk_get_prop_stridx(thr, idx_in, DUK_STRIDX_VALUE)) {
is_data_desc = 1;
defprop_flags |= DUK_DEFPROP_HAVE_VALUE;
idx_value = duk_get_top_index(thr);
}
if (duk_get_prop_stridx(thr, idx_in, DUK_STRIDX_WRITABLE)) {
is_data_desc = 1;
if (duk_to_boolean_top_pop(thr)) {
defprop_flags |= DUK_DEFPROP_HAVE_WRITABLE | DUK_DEFPROP_WRITABLE;
} else {
defprop_flags |= DUK_DEFPROP_HAVE_WRITABLE;
}
}
if (duk_get_prop_stridx(thr, idx_in, DUK_STRIDX_GET)) {
duk_tval *tv = duk_require_tval(thr, -1);
duk_hobject *h_get;
if (DUK_TVAL_IS_UNDEFINED(tv)) {
/* undefined is accepted */
DUK_ASSERT(getter == NULL);
} else {
/* NOTE: lightfuncs are coerced to full functions because
* lightfuncs don't fit into a property value slot. This
* has some side effects, see test-dev-lightfunc-accessor.js.
*/
h_get = duk_get_hobject_promote_lfunc(thr, -1);
if (h_get == NULL || !DUK_HOBJECT_IS_CALLABLE(h_get)) {
goto type_error;
}
getter = h_get;
}
is_acc_desc = 1;
defprop_flags |= DUK_DEFPROP_HAVE_GETTER;
}
if (duk_get_prop_stridx(thr, idx_in, DUK_STRIDX_SET)) {
duk_tval *tv = duk_require_tval(thr, -1);
duk_hobject *h_set;
if (DUK_TVAL_IS_UNDEFINED(tv)) {
/* undefined is accepted */
DUK_ASSERT(setter == NULL);
} else {
/* NOTE: lightfuncs are coerced to full functions because
* lightfuncs don't fit into a property value slot. This
* has some side effects, see test-dev-lightfunc-accessor.js.
*/
h_set = duk_get_hobject_promote_lfunc(thr, -1);
if (h_set == NULL || !DUK_HOBJECT_IS_CALLABLE(h_set)) {
goto type_error;
}
setter = h_set;
}
is_acc_desc = 1;
defprop_flags |= DUK_DEFPROP_HAVE_SETTER;
}
if (duk_get_prop_stridx(thr, idx_in, DUK_STRIDX_ENUMERABLE)) {
if (duk_to_boolean_top_pop(thr)) {
defprop_flags |= DUK_DEFPROP_HAVE_ENUMERABLE | DUK_DEFPROP_ENUMERABLE;
} else {
defprop_flags |= DUK_DEFPROP_HAVE_ENUMERABLE;
}
}
if (duk_get_prop_stridx(thr, idx_in, DUK_STRIDX_CONFIGURABLE)) {
if (duk_to_boolean_top_pop(thr)) {
defprop_flags |= DUK_DEFPROP_HAVE_CONFIGURABLE | DUK_DEFPROP_CONFIGURABLE;
} else {
defprop_flags |= DUK_DEFPROP_HAVE_CONFIGURABLE;
}
}
if (is_data_desc && is_acc_desc) {
goto type_error;
}
*out_defprop_flags = defprop_flags;
*out_idx_value = idx_value;
*out_getter = getter;
*out_setter = setter;
/* [ ... [multiple values] ] */
return;
type_error:
DUK_ERROR_TYPE(thr, DUK_STR_INVALID_DESCRIPTOR);
DUK_WO_NORETURN(return;);
}
/*
* Object.defineProperty() related helper (E5 Section 15.2.3.6).
* Also handles ES2015 Reflect.defineProperty().
*
* Inlines all [[DefineOwnProperty]] exotic behaviors.
*
* Note: ECMAScript compliant [[DefineOwnProperty]](P, Desc, Throw) is not
* implemented directly, but Object.defineProperty() serves its purpose.
* We don't need the [[DefineOwnProperty]] internally and we don't have a
* property descriptor with 'missing values' so it's easier to avoid it
* entirely.
*
* Note: this is only called for actual objects, not primitive values.
* This must support virtual properties for full objects (e.g. Strings)
* but not for plain values (e.g. strings). Lightfuncs, even though
* primitive in a sense, are treated like objects and accepted as target
* values.
*/
/* XXX: this is a major target for size optimization */
DUK_INTERNAL
duk_bool_t duk_hobject_define_property_helper(duk_hthread *thr,
duk_uint_t defprop_flags,
duk_hobject *obj,
duk_hstring *key,
duk_idx_t idx_value,
duk_hobject *get,
duk_hobject *set,
duk_bool_t throw_flag) {
duk_uint32_t arr_idx;
duk_tval tv;
duk_bool_t has_enumerable;
duk_bool_t has_configurable;
duk_bool_t has_writable;
duk_bool_t has_value;
duk_bool_t has_get;
duk_bool_t has_set;
duk_bool_t is_enumerable;
duk_bool_t is_configurable;
duk_bool_t is_writable;
duk_bool_t force_flag;
duk_small_uint_t new_flags;
duk_propdesc curr;
duk_uint32_t arridx_new_array_length; /* != 0 => post-update for array 'length' (used when key is an array index) */
duk_uint32_t arrlen_old_len;
duk_uint32_t arrlen_new_len;
duk_bool_t pending_write_protect;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT(key != NULL);
/* idx_value may be < 0 (no value), set and get may be NULL */
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
/* All the flags fit in 16 bits, so will fit into duk_bool_t. */
has_writable = (defprop_flags & DUK_DEFPROP_HAVE_WRITABLE);
has_enumerable = (defprop_flags & DUK_DEFPROP_HAVE_ENUMERABLE);
has_configurable = (defprop_flags & DUK_DEFPROP_HAVE_CONFIGURABLE);
has_value = (defprop_flags & DUK_DEFPROP_HAVE_VALUE);
has_get = (defprop_flags & DUK_DEFPROP_HAVE_GETTER);
has_set = (defprop_flags & DUK_DEFPROP_HAVE_SETTER);
is_writable = (defprop_flags & DUK_DEFPROP_WRITABLE);
is_enumerable = (defprop_flags & DUK_DEFPROP_ENUMERABLE);
is_configurable = (defprop_flags & DUK_DEFPROP_CONFIGURABLE);
force_flag = (defprop_flags & DUK_DEFPROP_FORCE);
arr_idx = DUK_HSTRING_GET_ARRIDX_SLOW(key);
arridx_new_array_length = 0;
pending_write_protect = 0;
arrlen_old_len = 0;
arrlen_new_len = 0;
DUK_DDD(DUK_DDDPRINT("has_enumerable=%ld is_enumerable=%ld "
"has_configurable=%ld is_configurable=%ld "
"has_writable=%ld is_writable=%ld "
"has_value=%ld value=%!T "
"has_get=%ld get=%p=%!O "
"has_set=%ld set=%p=%!O "
"arr_idx=%ld throw_flag=!%ld",
(long) has_enumerable, (long) is_enumerable,
(long) has_configurable, (long) is_configurable,
(long) has_writable, (long) is_writable,
(long) has_value, (duk_tval *) (idx_value >= 0 ? duk_get_tval(thr, idx_value) : NULL),
(long) has_get, (void *) get, (duk_heaphdr *) get,
(long) has_set, (void *) set, (duk_heaphdr *) set,
(long) arr_idx, (long) throw_flag));
/*
* Array exotic behaviors can be implemented at this point. The local variables
* are essentially a 'value copy' of the input descriptor (Desc), which is modified
* by the Array [[DefineOwnProperty]] (E5 Section 15.4.5.1).
*/
if (!DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
goto skip_array_exotic;
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr)) {
duk_harray *a;
/* E5 Section 15.4.5.1, step 3, steps a - i are implemented here, j - n at the end */
if (!has_value) {
DUK_DDD(DUK_DDDPRINT("exotic array behavior for 'length', but no value in descriptor -> normal behavior"));
goto skip_array_exotic;
}
DUK_DDD(DUK_DDDPRINT("exotic array behavior for 'length', value present in descriptor -> exotic behavior"));
/*
* Get old and new length
*/
a = (duk_harray *) obj;
DUK_HARRAY_ASSERT_VALID(a);
arrlen_old_len = a->length;
DUK_ASSERT(idx_value >= 0);
arrlen_new_len = duk__to_new_array_length_checked(thr, DUK_GET_TVAL_POSIDX(thr, idx_value));
duk_push_u32(thr, arrlen_new_len);
duk_replace(thr, idx_value); /* step 3.e: replace 'Desc.[[Value]]' */
DUK_DDD(DUK_DDDPRINT("old_len=%ld, new_len=%ld", (long) arrlen_old_len, (long) arrlen_new_len));
if (arrlen_new_len >= arrlen_old_len) {
/* standard behavior, step 3.f.i */
DUK_DDD(DUK_DDDPRINT("new length is same or higher as previous => standard behavior"));
goto skip_array_exotic;
}
DUK_DDD(DUK_DDDPRINT("new length is smaller than previous => exotic post behavior"));
/* XXX: consolidated algorithm step 15.f -> redundant? */
if (DUK_HARRAY_LENGTH_NONWRITABLE(a) && !force_flag) {
/* Array .length is always non-configurable; if it's also
* non-writable, don't allow it to be written.
*/
goto fail_not_configurable;
}
/* steps 3.h and 3.i */
if (has_writable && !is_writable) {
DUK_DDD(DUK_DDDPRINT("desc writable is false, force it back to true, and flag pending write protect"));
is_writable = 1;
pending_write_protect = 1;
}
/* remaining actual steps are carried out if standard DefineOwnProperty succeeds */
} else if (arr_idx != DUK__NO_ARRAY_INDEX) {
/* XXX: any chance of unifying this with the 'length' key handling? */
/* E5 Section 15.4.5.1, step 4 */
duk_uint32_t old_len;
duk_harray *a;
a = (duk_harray *) obj;
DUK_HARRAY_ASSERT_VALID(a);
old_len = a->length;
if (arr_idx >= old_len) {
DUK_DDD(DUK_DDDPRINT("defineProperty requires array length update "
"(arr_idx=%ld, old_len=%ld)",
(long) arr_idx, (long) old_len));
if (DUK_HARRAY_LENGTH_NONWRITABLE(a) && !force_flag) {
/* Array .length is always non-configurable, so
* if it's also non-writable, don't allow a value
* write. With force flag allow writing.
*/
goto fail_not_configurable;
}
/* actual update happens once write has been completed without
* error below.
*/
DUK_ASSERT(arr_idx != 0xffffffffUL);
arridx_new_array_length = arr_idx + 1;
} else {
DUK_DDD(DUK_DDDPRINT("defineProperty does not require length update "
"(arr_idx=%ld, old_len=%ld) -> standard behavior",
(long) arr_idx, (long) old_len));
}
}
skip_array_exotic:
/* XXX: There is currently no support for writing buffer object
* indexed elements here. Attempt to do so will succeed and
* write a concrete property into the buffer object. This should
* be fixed at some point but because buffers are a custom feature
* anyway, this is relatively unimportant.
*/
/*
* Actual Object.defineProperty() default algorithm.
*/
/*
* First check whether property exists; if not, simple case. This covers
* steps 1-4.
*/
if (!duk__get_own_propdesc_raw(thr, obj, key, arr_idx, &curr, DUK_GETDESC_FLAG_PUSH_VALUE)) {
DUK_DDD(DUK_DDDPRINT("property does not exist"));
if (!DUK_HOBJECT_HAS_EXTENSIBLE(obj) && !force_flag) {
goto fail_not_extensible;
}
#if defined(DUK_USE_ROM_OBJECTS)
/* ROM objects are never extensible but force flag may
* allow us to come here anyway.
*/
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj) || !DUK_HOBJECT_HAS_EXTENSIBLE(obj));
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)) {
DUK_D(DUK_DPRINT("attempt to define property on a read-only target object"));
goto fail_not_configurable;
}
#endif
/* XXX: share final setting code for value and flags? difficult because
* refcount code is different. Share entry allocation? But can't allocate
* until array index checked.
*/
/* steps 4.a and 4.b are tricky */
if (has_set || has_get) {
duk_int_t e_idx;
DUK_DDD(DUK_DDDPRINT("create new accessor property"));
DUK_ASSERT(has_set || set == NULL);
DUK_ASSERT(has_get || get == NULL);
DUK_ASSERT(!has_value);
DUK_ASSERT(!has_writable);
new_flags = DUK_PROPDESC_FLAG_ACCESSOR; /* defaults, E5 Section 8.6.1, Table 7 */
if (has_enumerable && is_enumerable) {
new_flags |= DUK_PROPDESC_FLAG_ENUMERABLE;
}
if (has_configurable && is_configurable) {
new_flags |= DUK_PROPDESC_FLAG_CONFIGURABLE;
}
if (arr_idx != DUK__NO_ARRAY_INDEX && DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
DUK_DDD(DUK_DDDPRINT("accessor cannot go to array part, abandon array"));
duk__abandon_array_part(thr, obj);
}
/* write to entry part */
e_idx = duk__hobject_alloc_entry_checked(thr, obj, key);
DUK_ASSERT(e_idx >= 0);
DUK_HOBJECT_E_SET_VALUE_GETTER(thr->heap, obj, e_idx, get);
DUK_HOBJECT_E_SET_VALUE_SETTER(thr->heap, obj, e_idx, set);
DUK_HOBJECT_INCREF_ALLOWNULL(thr, get);
DUK_HOBJECT_INCREF_ALLOWNULL(thr, set);
DUK_HOBJECT_E_SET_FLAGS(thr->heap, obj, e_idx, new_flags);
goto success_exotics;
} else {
duk_int_t e_idx;
duk_tval *tv2;
DUK_DDD(DUK_DDDPRINT("create new data property"));
DUK_ASSERT(!has_set);
DUK_ASSERT(!has_get);
new_flags = 0; /* defaults, E5 Section 8.6.1, Table 7 */
if (has_writable && is_writable) {
new_flags |= DUK_PROPDESC_FLAG_WRITABLE;
}
if (has_enumerable && is_enumerable) {
new_flags |= DUK_PROPDESC_FLAG_ENUMERABLE;
}
if (has_configurable && is_configurable) {
new_flags |= DUK_PROPDESC_FLAG_CONFIGURABLE;
}
if (has_value) {
duk_tval *tv_tmp = duk_require_tval(thr, idx_value);
DUK_TVAL_SET_TVAL(&tv, tv_tmp);
} else {
DUK_TVAL_SET_UNDEFINED(&tv); /* default value */
}
if (arr_idx != DUK__NO_ARRAY_INDEX && DUK_HOBJECT_HAS_ARRAY_PART(obj)) {
if (new_flags == DUK_PROPDESC_FLAGS_WEC) {
DUK_DDD(DUK_DDDPRINT("new data property attributes match array defaults, attempt to write to array part"));
tv2 = duk__obtain_arridx_slot(thr, arr_idx, obj);
if (tv2 == NULL) {
DUK_DDD(DUK_DDDPRINT("failed writing to array part, abandoned array"));
} else {
DUK_DDD(DUK_DDDPRINT("success in writing to array part"));
DUK_ASSERT(DUK_HOBJECT_HAS_ARRAY_PART(obj));
DUK_ASSERT(DUK_TVAL_IS_UNUSED(tv2));
DUK_TVAL_SET_TVAL(tv2, &tv);
DUK_TVAL_INCREF(thr, tv2);
goto success_exotics;
}
} else {
DUK_DDD(DUK_DDDPRINT("new data property cannot go to array part, abandon array"));
duk__abandon_array_part(thr, obj);
}
/* fall through */
}
/* write to entry part */
e_idx = duk__hobject_alloc_entry_checked(thr, obj, key);
DUK_ASSERT(e_idx >= 0);
tv2 = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, e_idx);
DUK_TVAL_SET_TVAL(tv2, &tv);
DUK_TVAL_INCREF(thr, tv2);
DUK_HOBJECT_E_SET_FLAGS(thr->heap, obj, e_idx, new_flags);
goto success_exotics;
}
DUK_UNREACHABLE();
}
/* we currently assume virtual properties are not configurable (as none of them are) */
DUK_ASSERT((curr.e_idx >= 0 || curr.a_idx >= 0) || !(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE));
/* [obj key desc value get set curr_value] */
/*
* Property already exists. Steps 5-6 detect whether any changes need
* to be made.
*/
if (has_enumerable) {
if (is_enumerable) {
if (!(curr.flags & DUK_PROPDESC_FLAG_ENUMERABLE)) {
goto need_check;
}
} else {
if (curr.flags & DUK_PROPDESC_FLAG_ENUMERABLE) {
goto need_check;
}
}
}
if (has_configurable) {
if (is_configurable) {
if (!(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE)) {
goto need_check;
}
} else {
if (curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) {
goto need_check;
}
}
}
if (has_value) {
duk_tval *tmp1;
duk_tval *tmp2;
/* attempt to change from accessor to data property */
if (curr.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
goto need_check;
}
tmp1 = duk_require_tval(thr, -1); /* curr value */
tmp2 = duk_require_tval(thr, idx_value); /* new value */
if (!duk_js_samevalue(tmp1, tmp2)) {
goto need_check;
}
}
if (has_writable) {
/* attempt to change from accessor to data property */
if (curr.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
goto need_check;
}
if (is_writable) {
if (!(curr.flags & DUK_PROPDESC_FLAG_WRITABLE)) {
goto need_check;
}
} else {
if (curr.flags & DUK_PROPDESC_FLAG_WRITABLE) {
goto need_check;
}
}
}
if (has_set) {
if (curr.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
if (set != curr.set) {
goto need_check;
}
} else {
goto need_check;
}
}
if (has_get) {
if (curr.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
if (get != curr.get) {
goto need_check;
}
} else {
goto need_check;
}
}
/* property exists, either 'desc' is empty, or all values
* match (SameValue)
*/
goto success_no_exotics;
need_check:
/*
* Some change(s) need to be made. Steps 7-11.
*/
/* shared checks for all descriptor types */
if (!(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) && !force_flag) {
if (has_configurable && is_configurable) {
goto fail_not_configurable;
}
if (has_enumerable) {
if (curr.flags & DUK_PROPDESC_FLAG_ENUMERABLE) {
if (!is_enumerable) {
goto fail_not_configurable;
}
} else {
if (is_enumerable) {
goto fail_not_configurable;
}
}
}
}
/* Virtual properties don't have backing so they can't mostly be
* edited. Some virtual properties are, however, writable: for
* example, virtual index properties of buffer objects and Array
* instance .length. These are not configurable so the checks
* above mostly cover attempts to change them, except when the
* duk_def_prop() call is used with DUK_DEFPROP_FORCE; even in
* that case we can't forcibly change the property attributes
* because they don't have concrete backing.
*/
/* XXX: for ROM objects too it'd be best if value modify was
* allowed if the value matches SameValue.
*/
/* Reject attempt to change a read-only object. */
#if defined(DUK_USE_ROM_OBJECTS)
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)) {
DUK_DD(DUK_DDPRINT("attempt to define property on read-only target object"));
goto fail_not_configurable;
}
#endif
/* descriptor type specific checks */
if (has_set || has_get) {
/* IsAccessorDescriptor(desc) == true */
DUK_ASSERT(!has_writable);
DUK_ASSERT(!has_value);
if (curr.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
/* curr and desc are accessors */
if (!(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) && !force_flag) {
if (has_set && set != curr.set) {
goto fail_not_configurable;
}
if (has_get && get != curr.get) {
goto fail_not_configurable;
}
}
} else {
duk_bool_t rc;
duk_tval *tv1;
/* curr is data, desc is accessor */
if (!(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) && !force_flag) {
goto fail_not_configurable;
}
DUK_DDD(DUK_DDDPRINT("convert property to accessor property"));
if (curr.a_idx >= 0) {
DUK_DDD(DUK_DDDPRINT("property to convert is stored in an array entry, abandon array and re-lookup"));
duk__abandon_array_part(thr, obj);
duk_pop_unsafe(thr); /* remove old value */
rc = duk__get_own_propdesc_raw(thr, obj, key, arr_idx, &curr, DUK_GETDESC_FLAG_PUSH_VALUE);
DUK_UNREF(rc);
DUK_ASSERT(rc != 0);
DUK_ASSERT(curr.e_idx >= 0 && curr.a_idx < 0);
}
if (curr.e_idx < 0) {
DUK_ASSERT(curr.a_idx < 0 && curr.e_idx < 0);
goto fail_virtual; /* safeguard for virtual property */
}
DUK_ASSERT(curr.e_idx >= 0);
DUK_ASSERT(!DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, curr.e_idx));
tv1 = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, curr.e_idx);
DUK_TVAL_SET_UNDEFINED_UPDREF_NORZ(thr, tv1); /* XXX: just decref */
DUK_HOBJECT_E_SET_VALUE_GETTER(thr->heap, obj, curr.e_idx, NULL);
DUK_HOBJECT_E_SET_VALUE_SETTER(thr->heap, obj, curr.e_idx, NULL);
DUK_HOBJECT_E_SLOT_CLEAR_WRITABLE(thr->heap, obj, curr.e_idx);
DUK_HOBJECT_E_SLOT_SET_ACCESSOR(thr->heap, obj, curr.e_idx);
DUK_DDD(DUK_DDDPRINT("flags after data->accessor conversion: 0x%02lx",
(unsigned long) DUK_HOBJECT_E_GET_FLAGS(thr->heap, obj, curr.e_idx)));
/* Update curr.flags; faster than a re-lookup. */
curr.flags &= ~DUK_PROPDESC_FLAG_WRITABLE;
curr.flags |= DUK_PROPDESC_FLAG_ACCESSOR;
}
} else if (has_value || has_writable) {
/* IsDataDescriptor(desc) == true */
DUK_ASSERT(!has_set);
DUK_ASSERT(!has_get);
if (curr.flags & DUK_PROPDESC_FLAG_ACCESSOR) {
duk_hobject *tmp;
/* curr is accessor, desc is data */
if (!(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) && !force_flag) {
goto fail_not_configurable;
}
/* curr is accessor -> cannot be in array part. */
DUK_ASSERT(curr.a_idx < 0);
if (curr.e_idx < 0) {
goto fail_virtual; /* safeguard; no virtual accessors now */
}
DUK_DDD(DUK_DDDPRINT("convert property to data property"));
DUK_ASSERT(DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, curr.e_idx));
tmp = DUK_HOBJECT_E_GET_VALUE_GETTER(thr->heap, obj, curr.e_idx);
DUK_UNREF(tmp);
DUK_HOBJECT_E_SET_VALUE_GETTER(thr->heap, obj, curr.e_idx, NULL);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, tmp);
tmp = DUK_HOBJECT_E_GET_VALUE_SETTER(thr->heap, obj, curr.e_idx);
DUK_UNREF(tmp);
DUK_HOBJECT_E_SET_VALUE_SETTER(thr->heap, obj, curr.e_idx, NULL);
DUK_HOBJECT_DECREF_NORZ_ALLOWNULL(thr, tmp);
DUK_TVAL_SET_UNDEFINED(DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, curr.e_idx));
DUK_HOBJECT_E_SLOT_CLEAR_WRITABLE(thr->heap, obj, curr.e_idx);
DUK_HOBJECT_E_SLOT_CLEAR_ACCESSOR(thr->heap, obj, curr.e_idx);
DUK_DDD(DUK_DDDPRINT("flags after accessor->data conversion: 0x%02lx",
(unsigned long) DUK_HOBJECT_E_GET_FLAGS(thr->heap, obj, curr.e_idx)));
/* Update curr.flags; faster than a re-lookup. */
curr.flags &= ~(DUK_PROPDESC_FLAG_WRITABLE | DUK_PROPDESC_FLAG_ACCESSOR);
} else {
/* curr and desc are data */
if (!(curr.flags & DUK_PROPDESC_FLAG_CONFIGURABLE) && !force_flag) {
if (!(curr.flags & DUK_PROPDESC_FLAG_WRITABLE) && has_writable && is_writable) {
goto fail_not_configurable;
}
/* Note: changing from writable to non-writable is OK */
if (!(curr.flags & DUK_PROPDESC_FLAG_WRITABLE) && has_value) {
duk_tval *tmp1 = duk_require_tval(thr, -1); /* curr value */
duk_tval *tmp2 = duk_require_tval(thr, idx_value); /* new value */
if (!duk_js_samevalue(tmp1, tmp2)) {
goto fail_not_configurable;
}
}
}
}
} else {
/* IsGenericDescriptor(desc) == true; this means in practice that 'desc'
* only has [[Enumerable]] or [[Configurable]] flag updates, which are
* allowed at this point.
*/
DUK_ASSERT(!has_value && !has_writable && !has_get && !has_set);
}
/*
* Start doing property attributes updates. Steps 12-13.
*
* Start by computing new attribute flags without writing yet.
* Property type conversion is done above if necessary.
*/
new_flags = curr.flags;
if (has_enumerable) {
if (is_enumerable) {
new_flags |= DUK_PROPDESC_FLAG_ENUMERABLE;
} else {
new_flags &= ~DUK_PROPDESC_FLAG_ENUMERABLE;
}
}
if (has_configurable) {
if (is_configurable) {
new_flags |= DUK_PROPDESC_FLAG_CONFIGURABLE;
} else {
new_flags &= ~DUK_PROPDESC_FLAG_CONFIGURABLE;
}
}
if (has_writable) {
if (is_writable) {
new_flags |= DUK_PROPDESC_FLAG_WRITABLE;
} else {
new_flags &= ~DUK_PROPDESC_FLAG_WRITABLE;
}
}
/* XXX: write protect after flag? -> any chance of handling it here? */
DUK_DDD(DUK_DDDPRINT("new flags that we want to write: 0x%02lx",
(unsigned long) new_flags));
/*
* Check whether we need to abandon an array part (if it exists)
*/
if (curr.a_idx >= 0) {
duk_bool_t rc;
DUK_ASSERT(curr.e_idx < 0);
if (new_flags == DUK_PROPDESC_FLAGS_WEC) {
duk_tval *tv1, *tv2;
DUK_DDD(DUK_DDDPRINT("array index, new property attributes match array defaults, update in-place"));
DUK_ASSERT(curr.flags == DUK_PROPDESC_FLAGS_WEC); /* must have been, since in array part */
DUK_ASSERT(!has_set);
DUK_ASSERT(!has_get);
DUK_ASSERT(idx_value >= 0); /* must be: if attributes match and we get here the value must differ (otherwise no change) */
tv2 = duk_require_tval(thr, idx_value);
tv1 = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, curr.a_idx);
DUK_TVAL_SET_TVAL_UPDREF(thr, tv1, tv2); /* side effects; may invalidate a_idx */
goto success_exotics;
}
DUK_DDD(DUK_DDDPRINT("array index, new property attributes do not match array defaults, abandon array and re-lookup"));
duk__abandon_array_part(thr, obj);
duk_pop_unsafe(thr); /* remove old value */
rc = duk__get_own_propdesc_raw(thr, obj, key, arr_idx, &curr, DUK_GETDESC_FLAG_PUSH_VALUE);
DUK_UNREF(rc);
DUK_ASSERT(rc != 0);
DUK_ASSERT(curr.e_idx >= 0 && curr.a_idx < 0);
}
DUK_DDD(DUK_DDDPRINT("updating existing property in entry part"));
/* Array case is handled comprehensively above: either in entry
* part or a virtual property.
*/
DUK_ASSERT(curr.a_idx < 0);
DUK_DDD(DUK_DDDPRINT("update existing property attributes"));
if (curr.e_idx >= 0) {
DUK_HOBJECT_E_SET_FLAGS(thr->heap, obj, curr.e_idx, new_flags);
} else {
/* For Array .length the only allowed transition is for .length
* to become non-writable.
*/
if (key == DUK_HTHREAD_STRING_LENGTH(thr) && DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
duk_harray *a;
a = (duk_harray *) obj;
DUK_DD(DUK_DDPRINT("Object.defineProperty() attribute update for duk_harray .length -> %02lx", (unsigned long) new_flags));
DUK_HARRAY_ASSERT_VALID(a);
if ((new_flags & DUK_PROPDESC_FLAGS_EC) != (curr.flags & DUK_PROPDESC_FLAGS_EC)) {
DUK_D(DUK_DPRINT("Object.defineProperty() attempt to change virtual array .length enumerable or configurable attribute, fail"));
goto fail_virtual;
}
if (new_flags & DUK_PROPDESC_FLAG_WRITABLE) {
DUK_HARRAY_SET_LENGTH_WRITABLE(a);
} else {
DUK_HARRAY_SET_LENGTH_NONWRITABLE(a);
}
}
}
if (has_set) {
duk_hobject *tmp;
/* Virtual properties are non-configurable but with a 'force'
* flag we might come here so check explicitly for virtual.
*/
if (curr.e_idx < 0) {
goto fail_virtual;
}
DUK_DDD(DUK_DDDPRINT("update existing property setter"));
DUK_ASSERT(DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, curr.e_idx));
tmp = DUK_HOBJECT_E_GET_VALUE_SETTER(thr->heap, obj, curr.e_idx);
DUK_UNREF(tmp);
DUK_HOBJECT_E_SET_VALUE_SETTER(thr->heap, obj, curr.e_idx, set);
DUK_HOBJECT_INCREF_ALLOWNULL(thr, set);
DUK_HOBJECT_DECREF_ALLOWNULL(thr, tmp); /* side effects; may invalidate e_idx */
}
if (has_get) {
duk_hobject *tmp;
if (curr.e_idx < 0) {
goto fail_virtual;
}
DUK_DDD(DUK_DDDPRINT("update existing property getter"));
DUK_ASSERT(DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, curr.e_idx));
tmp = DUK_HOBJECT_E_GET_VALUE_GETTER(thr->heap, obj, curr.e_idx);
DUK_UNREF(tmp);
DUK_HOBJECT_E_SET_VALUE_GETTER(thr->heap, obj, curr.e_idx, get);
DUK_HOBJECT_INCREF_ALLOWNULL(thr, get);
DUK_HOBJECT_DECREF_ALLOWNULL(thr, tmp); /* side effects; may invalidate e_idx */
}
if (has_value) {
duk_tval *tv1, *tv2;
DUK_DDD(DUK_DDDPRINT("update existing property value"));
if (curr.e_idx >= 0) {
DUK_ASSERT(!DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, obj, curr.e_idx));
tv2 = duk_require_tval(thr, idx_value);
tv1 = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, obj, curr.e_idx);
DUK_TVAL_SET_TVAL_UPDREF(thr, tv1, tv2); /* side effects; may invalidate e_idx */
} else {
DUK_ASSERT(curr.a_idx < 0); /* array part case handled comprehensively previously */
DUK_DD(DUK_DDPRINT("Object.defineProperty(), value update for virtual property"));
/* XXX: Uint8Array and other typed array virtual writes not currently
* handled.
*/
if (key == DUK_HTHREAD_STRING_LENGTH(thr) && DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
duk_harray *a;
a = (duk_harray *) obj;
DUK_DD(DUK_DDPRINT("Object.defineProperty() value update for duk_harray .length -> %ld", (long) arrlen_new_len));
DUK_HARRAY_ASSERT_VALID(a);
a->length = arrlen_new_len;
} else {
goto fail_virtual; /* should not happen */
}
}
}
/*
* Standard algorithm succeeded without errors, check for exotic post-behaviors.
*
* Arguments exotic behavior in E5 Section 10.6 occurs after the standard
* [[DefineOwnProperty]] has completed successfully.
*
* Array exotic behavior in E5 Section 15.4.5.1 is implemented partly
* prior to the default [[DefineOwnProperty]], but:
* - for an array index key (e.g. "10") the final 'length' update occurs here
* - for 'length' key the element deletion and 'length' update occurs here
*/
success_exotics:
/* curr.a_idx or curr.e_idx may have been invalidated by side effects
* above.
*/
/* [obj key desc value get set curr_value] */
if (DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)) {
duk_harray *a;
a = (duk_harray *) obj;
DUK_HARRAY_ASSERT_VALID(a);
if (arridx_new_array_length > 0) {
/*
* Note: zero works as a "no update" marker because the new length
* can never be zero after a new property is written.
*/
/* E5 Section 15.4.5.1, steps 4.e.i - 4.e.ii */
DUK_DDD(DUK_DDDPRINT("defineProperty successful, pending array length update to: %ld",
(long) arridx_new_array_length));
a->length = arridx_new_array_length;
}
if (key == DUK_HTHREAD_STRING_LENGTH(thr) && arrlen_new_len < arrlen_old_len) {
/*
* E5 Section 15.4.5.1, steps 3.k - 3.n. The order at the end combines
* the error case 3.l.iii and the success case 3.m-3.n.
*/
/* XXX: investigate whether write protect can be handled above, if we
* just update length here while ignoring its protected status
*/
duk_uint32_t result_len;
duk_bool_t rc;
DUK_DDD(DUK_DDDPRINT("defineProperty successful, key is 'length', exotic array behavior, "
"doing array element deletion and length update"));
rc = duk__handle_put_array_length_smaller(thr, obj, arrlen_old_len, arrlen_new_len, force_flag, &result_len);
/* update length (curr points to length, and we assume it's still valid) */
DUK_ASSERT(result_len >= arrlen_new_len && result_len <= arrlen_old_len);
a->length = result_len;
if (pending_write_protect) {
DUK_DDD(DUK_DDDPRINT("setting array length non-writable (pending writability update)"));
DUK_HARRAY_SET_LENGTH_NONWRITABLE(a);
}
/* XXX: shrink array allocation or entries compaction here? */
if (!rc) {
DUK_DD(DUK_DDPRINT("array length write only partially successful"));
goto fail_not_configurable;
}
}
} else if (arr_idx != DUK__NO_ARRAY_INDEX && DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj)) {
duk_hobject *map;
duk_hobject *varenv;
DUK_ASSERT(arridx_new_array_length == 0);
DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj)); /* traits are separate; in particular, arguments not an array */
map = NULL;
varenv = NULL;
if (!duk__lookup_arguments_map(thr, obj, key, &curr, &map, &varenv)) {
goto success_no_exotics;
}
DUK_ASSERT(map != NULL);
DUK_ASSERT(varenv != NULL);
/* [obj key desc value get set curr_value varname] */
if (has_set || has_get) {
/* = IsAccessorDescriptor(Desc) */
DUK_DDD(DUK_DDDPRINT("defineProperty successful, key mapped to arguments 'map' "
"changed to an accessor, delete arguments binding"));
(void) duk_hobject_delprop_raw(thr, map, key, 0); /* ignore result */
} else {
/* Note: this order matters (final value before deleting map entry must be done) */
DUK_DDD(DUK_DDDPRINT("defineProperty successful, key mapped to arguments 'map', "
"check for value update / binding deletion"));
if (has_value) {
duk_hstring *varname;
DUK_DDD(DUK_DDDPRINT("defineProperty successful, key mapped to arguments 'map', "
"update bound value (variable/argument)"));
varname = duk_require_hstring(thr, -1);
DUK_ASSERT(varname != NULL);
DUK_DDD(DUK_DDDPRINT("arguments object automatic putvar for a bound variable; "
"key=%!O, varname=%!O, value=%!T",
(duk_heaphdr *) key,
(duk_heaphdr *) varname,
(duk_tval *) duk_require_tval(thr, idx_value)));
/* strict flag for putvar comes from our caller (currently: fixed) */
duk_js_putvar_envrec(thr, varenv, varname, duk_require_tval(thr, idx_value), 1 /*throw_flag*/);
}
if (has_writable && !is_writable) {
DUK_DDD(DUK_DDDPRINT("defineProperty successful, key mapped to arguments 'map', "
"changed to non-writable, delete arguments binding"));
(void) duk_hobject_delprop_raw(thr, map, key, 0); /* ignore result */
}
}
/* 'varname' is in stack in this else branch, leaving an unbalanced stack below,
* but this doesn't matter now.
*/
}
success_no_exotics:
/* Some code paths use NORZ macros for simplicity, ensure refzero
* handling is completed.
*/
DUK_REFZERO_CHECK_SLOW(thr);
return 1;
fail_not_extensible:
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_EXTENSIBLE);
DUK_WO_NORETURN(return 0;);
}
return 0;
fail_virtual: /* just use the same "not configurable" error message" */
fail_not_configurable:
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
DUK_WO_NORETURN(return 0;);
}
return 0;
}
/*
* Object.prototype.hasOwnProperty() and Object.prototype.propertyIsEnumerable().
*/
DUK_INTERNAL duk_bool_t duk_hobject_object_ownprop_helper(duk_hthread *thr, duk_small_uint_t required_desc_flags) {
duk_hstring *h_v;
duk_hobject *h_obj;
duk_propdesc desc;
duk_bool_t ret;
/* coercion order matters */
h_v = duk_to_hstring_acceptsymbol(thr, 0);
DUK_ASSERT(h_v != NULL);
h_obj = duk_push_this_coercible_to_object(thr);
DUK_ASSERT(h_obj != NULL);
ret = duk_hobject_get_own_propdesc(thr, h_obj, h_v, &desc, 0 /*flags*/); /* don't push value */
duk_push_boolean(thr, ret && ((desc.flags & required_desc_flags) == required_desc_flags));
return 1;
}
/*
* Object.seal() and Object.freeze() (E5 Sections 15.2.3.8 and 15.2.3.9)
*
* Since the algorithms are similar, a helper provides both functions.
* Freezing is essentially sealing + making plain properties non-writable.
*
* Note: virtual (non-concrete) properties which are non-configurable but
* writable would pose some problems, but such properties do not currently
* exist (all virtual properties are non-configurable and non-writable).
* If they did exist, the non-configurability does NOT prevent them from
* becoming non-writable. However, this change should be recorded somehow
* so that it would turn up (e.g. when getting the property descriptor),
* requiring some additional flags in the object.
*/
DUK_INTERNAL void duk_hobject_object_seal_freeze_helper(duk_hthread *thr, duk_hobject *obj, duk_bool_t is_freeze) {
duk_uint_fast32_t i;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);
#if defined(DUK_USE_ROM_OBJECTS)
if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)) {
DUK_DD(DUK_DDPRINT("attempt to seal/freeze a readonly object, reject"));
DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
DUK_WO_NORETURN(return;);
}
#endif
/*
* Abandon array part because all properties must become non-configurable.
* Note that this is now done regardless of whether this is always the case
* (skips check, but performance problem if caller would do this many times
* for the same object; not likely).
*/
duk__abandon_array_part(thr, obj);
DUK_ASSERT(DUK_HOBJECT_GET_ASIZE(obj) == 0);
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
duk_uint8_t *fp;
/* since duk__abandon_array_part() causes a resize, there should be no gaps in keys */
DUK_ASSERT(DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i) != NULL);
/* avoid multiple computations of flags address; bypasses macros */
fp = DUK_HOBJECT_E_GET_FLAGS_PTR(thr->heap, obj, i);
if (is_freeze && !((*fp) & DUK_PROPDESC_FLAG_ACCESSOR)) {
*fp &= ~(DUK_PROPDESC_FLAG_WRITABLE | DUK_PROPDESC_FLAG_CONFIGURABLE);
} else {
*fp &= ~DUK_PROPDESC_FLAG_CONFIGURABLE;
}
}
DUK_HOBJECT_CLEAR_EXTENSIBLE(obj);
/* no need to compact since we already did that in duk__abandon_array_part()
* (regardless of whether an array part existed or not.
*/
return;
}
/*
* Object.isSealed() and Object.isFrozen() (E5 Sections 15.2.3.11, 15.2.3.13)
*
* Since the algorithms are similar, a helper provides both functions.
* Freezing is essentially sealing + making plain properties non-writable.
*
* Note: all virtual (non-concrete) properties are currently non-configurable
* and non-writable (and there are no accessor virtual properties), so they don't
* need to be considered here now.
*/
DUK_INTERNAL duk_bool_t duk_hobject_object_is_sealed_frozen_helper(duk_hthread *thr, duk_hobject *obj, duk_bool_t is_frozen) {
duk_uint_fast32_t i;
DUK_ASSERT(obj != NULL);
DUK_UNREF(thr);
/* Note: no allocation pressure, no need to check refcounts etc */
/* must not be extensible */
if (DUK_HOBJECT_HAS_EXTENSIBLE(obj)) {
return 0;
}
/* all virtual properties are non-configurable and non-writable */
/* entry part must not contain any configurable properties, or
* writable properties (if is_frozen).
*/
for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
duk_small_uint_t flags;
if (!DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i)) {
continue;
}
/* avoid multiple computations of flags address; bypasses macros */
flags = (duk_small_uint_t) DUK_HOBJECT_E_GET_FLAGS(thr->heap, obj, i);
if (flags & DUK_PROPDESC_FLAG_CONFIGURABLE) {
return 0;
}
if (is_frozen &&
!(flags & DUK_PROPDESC_FLAG_ACCESSOR) &&
(flags & DUK_PROPDESC_FLAG_WRITABLE)) {
return 0;
}
}
/* array part must not contain any non-unused properties, as they would
* be configurable and writable.
*/
for (i = 0; i < DUK_HOBJECT_GET_ASIZE(obj); i++) {
duk_tval *tv = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, obj, i);
if (!DUK_TVAL_IS_UNUSED(tv)) {
return 0;
}
}
return 1;
}
/*
* Object.preventExtensions() and Object.isExtensible() (E5 Sections 15.2.3.10, 15.2.3.13)
*
* Not needed, implemented by macros DUK_HOBJECT_{HAS,CLEAR,SET}_EXTENSIBLE
* and the Object built-in bindings.
*/