Exemple #1
0
DUK_INTERNAL duk_ret_t duk_bi_proxy_constructor(duk_context *ctx) {
	duk_hobject *h_target;
	duk_hobject *h_handler;

	if (!duk_is_constructor_call(ctx)) {
		return DUK_RET_TYPE_ERROR;
	}

	/* Reject a proxy object as the target because it would need
	 * special handler in property lookups.  (ES6 has no such restriction)
	 */
	h_target = duk_require_hobject_or_lfunc_coerce(ctx, 0);
	DUK_ASSERT(h_target != NULL);
	if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(h_target)) {
		return DUK_RET_TYPE_ERROR;
	}

	/* Reject a proxy object as the handler because it would cause
	 * potentially unbounded recursion.  (ES6 has no such restriction)
	 */
	h_handler = duk_require_hobject_or_lfunc_coerce(ctx, 1);
	DUK_ASSERT(h_handler != NULL);
	if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(h_handler)) {
		return DUK_RET_TYPE_ERROR;
	}

	/* XXX: the returned value is exotic in ES6, but we use a
	 * simple object here with no prototype.  Without a prototype,
	 * [[DefaultValue]] coercion fails which is abit confusing.
	 * No callable check/handling in the current Proxy subset.
	 */
	(void) duk_push_object_helper_proto(ctx,
	                                    DUK_HOBJECT_FLAG_EXTENSIBLE |
	                                    DUK_HOBJECT_FLAG_EXOTIC_PROXYOBJ |
	                                    DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_OBJECT),
	                                    NULL);
	DUK_ASSERT_TOP(ctx, 3);

	/* Make _Target and _Handler non-configurable and non-writable.
	 * They can still be forcibly changed by C code (both user and
	 * Duktape internal), but not by Ecmascript code.
	 */

	/* Proxy target */
	duk_dup(ctx, 0);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_TARGET, DUK_PROPDESC_FLAGS_NONE);

	/* Proxy handler */
	duk_dup(ctx, 1);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_HANDLER, DUK_PROPDESC_FLAGS_NONE);

	return 1;  /* replacement handler */
}
DUK_INTERNAL void duk_hobject_run_finalizer(duk_hthread *thr, duk_hobject *obj) {
	duk_context *ctx = (duk_context *) thr;
	duk_ret_t rc;
#if defined(DUK_USE_ASSERTIONS)
	duk_idx_t entry_top;
#endif

	DUK_DDD(DUK_DDDPRINT("running object finalizer for object: %p", (void *) obj));

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(ctx != NULL);
	DUK_ASSERT(obj != NULL);
	DUK_ASSERT_VALSTACK_SPACE(thr, 1);

#if defined(DUK_USE_ASSERTIONS)
	entry_top = duk_get_top(ctx);
#endif
	/*
	 *  Get and call the finalizer.  All of this must be wrapped
	 *  in a protected call, because even getting the finalizer
	 *  may trigger an error (getter may throw one, for instance).
	 */

	DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj));
	if (DUK_HEAPHDR_HAS_FINALIZED((duk_heaphdr *) obj)) {
		DUK_D(DUK_DPRINT("object already finalized, avoid running finalizer twice: %!O", obj));
		return;
	}
	DUK_HEAPHDR_SET_FINALIZED((duk_heaphdr *) obj);  /* ensure never re-entered until rescue cycle complete */
	if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(obj)) {
		/* This shouldn't happen; call sites should avoid looking up
		 * _Finalizer "through" a Proxy, but ignore if we come here
		 * with a Proxy to avoid finalizer re-entry.
		 */
		DUK_D(DUK_DPRINT("object is a proxy, skip finalizer call"));
		return;
	}

	/* XXX: use a NULL error handler for the finalizer call? */

	DUK_DDD(DUK_DDDPRINT("-> finalizer found, calling wrapped finalize helper"));
	duk_push_hobject(ctx, obj);  /* this also increases refcount by one */
	rc = duk_safe_call(ctx, duk__finalize_helper, NULL /*udata*/, 0 /*nargs*/, 1 /*nrets*/);  /* -> [... obj retval/error] */
	DUK_ASSERT_TOP(ctx, entry_top + 2);  /* duk_safe_call discipline */

	if (rc != DUK_EXEC_SUCCESS) {
		/* Note: we ask for one return value from duk_safe_call to get this
		 * error debugging here.
		 */
		DUK_D(DUK_DPRINT("wrapped finalizer call failed for object %p (ignored); error: %!T",
		                 (void *) obj, (duk_tval *) duk_get_tval(ctx, -1)));
	}
	duk_pop_2(ctx);  /* -> [...] */

	DUK_ASSERT_TOP(ctx, entry_top);
}
Exemple #3
0
void duk_debug_dump_hobject(duk_hobject *obj) {
	duk_uint_fast32_t i;
	const char *str_empty = "";
	const char *str_excl = "!";

	DUK_D(DUK_DPRINT("=== hobject %p ===", (void *) obj));
	if (!obj) {
		return;
	}

	DUK_D(DUK_DPRINT("  %sextensible", DUK_HOBJECT_HAS_EXTENSIBLE(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sconstructable", DUK_HOBJECT_HAS_CONSTRUCTABLE(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sbound", DUK_HOBJECT_HAS_BOUND(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %scompiledfunction", DUK_HOBJECT_HAS_COMPILEDFUNCTION(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %snativefunction", DUK_HOBJECT_HAS_NATIVEFUNCTION(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sthread", DUK_HOBJECT_HAS_THREAD(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sarray_part", DUK_HOBJECT_HAS_ARRAY_PART(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sstrict", DUK_HOBJECT_HAS_STRICT(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %snewenv", DUK_HOBJECT_HAS_NEWENV(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %snamebinding", DUK_HOBJECT_HAS_NAMEBINDING(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %screateargs", DUK_HOBJECT_HAS_CREATEARGS(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %senvrecclosed", DUK_HOBJECT_HAS_ENVRECCLOSED(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sexotic_array", DUK_HOBJECT_HAS_EXOTIC_ARRAY(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sexotic_stringobj", DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sexotic_arguments", DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sexotic_dukfunc", DUK_HOBJECT_HAS_EXOTIC_DUKFUNC(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sexotic_bufferobj", DUK_HOBJECT_HAS_EXOTIC_BUFFEROBJ(obj) ? str_empty : str_excl));
	DUK_D(DUK_DPRINT("  %sexotic_proxyobj", DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(obj) ? str_empty : str_excl));

	DUK_D(DUK_DPRINT("  class: number %d -> %s",
	                 (int) DUK_HOBJECT_GET_CLASS_NUMBER(obj),
	                 duk__class_names[(DUK_HOBJECT_GET_CLASS_NUMBER(obj)) & ((1 << DUK_HOBJECT_FLAG_CLASS_BITS) - 1)]));

	DUK_D(DUK_DPRINT("  prototype: %p -> %!O",
	                 (void *) obj->prototype,
	                 (duk_heaphdr *) obj->prototype));

	DUK_D(DUK_DPRINT("  props: p=%p, e_size=%d, e_used=%d, a_size=%d, h_size=%d",
	                 (void *) obj->p,
	                 (int) obj->e_size,
	                 (int) obj->e_used,
	                 (int) obj->a_size,
	                 (int) obj->h_size));

	/*
	 *  Object (struct layout) specific dumping.  Inline code here
	 *  instead of helpers, to ensure debug line prefix is identical.
	 */

	if (DUK_HOBJECT_IS_COMPILEDFUNCTION(obj)) {
		duk_hcompiledfunction *h = (duk_hcompiledfunction *) obj;

		DUK_D(DUK_DPRINT("  hcompiledfunction"));
		DUK_D(DUK_DPRINT("  data: %!O", h->data));
		DUK_D(DUK_DPRINT("  nregs: %d", (int) h->nregs));
		DUK_D(DUK_DPRINT("  nargs: %d", (int) h->nargs));

		if (h->data && DUK_HBUFFER_HAS_DYNAMIC(h->data) && DUK_HBUFFER_GET_DATA_PTR(h->data)) {
			DUK_D(DUK_DPRINT("  consts: %p (%d, %d bytes)",
			                 (void *) DUK_HCOMPILEDFUNCTION_GET_CONSTS_BASE(h),
			                 (int) DUK_HCOMPILEDFUNCTION_GET_CONSTS_COUNT(h),
			                 (int) DUK_HCOMPILEDFUNCTION_GET_CONSTS_SIZE(h)));
			DUK_D(DUK_DPRINT("  funcs: %p (%d, %d bytes)",
			                 (void *) DUK_HCOMPILEDFUNCTION_GET_FUNCS_BASE(h),
			                 (int) DUK_HCOMPILEDFUNCTION_GET_FUNCS_COUNT(h),
			                 (int) DUK_HCOMPILEDFUNCTION_GET_FUNCS_SIZE(h)));
			DUK_D(DUK_DPRINT("  bytecode: %p (%d, %d bytes)",
			                 (void *) DUK_HCOMPILEDFUNCTION_GET_CODE_BASE(h),
			                 (int) DUK_HCOMPILEDFUNCTION_GET_CODE_COUNT(h),
			                 (int) DUK_HCOMPILEDFUNCTION_GET_CODE_SIZE(h)));
		} else {
			DUK_D(DUK_DPRINT("  consts: ???"));
			DUK_D(DUK_DPRINT("  funcs: ???"));
			DUK_D(DUK_DPRINT("  bytecode: ???"));
		}
	} else if (DUK_HOBJECT_IS_NATIVEFUNCTION(obj)) {
		duk_hnativefunction *h = (duk_hnativefunction *) obj;

		DUK_D(DUK_DPRINT("  hnativefunction"));
		/* XXX: h->func, cannot print function pointers portably */
		DUK_D(DUK_DPRINT("  nargs: %d", (int) h->nargs));
	} else if (DUK_HOBJECT_IS_THREAD(obj)) {
		duk_hthread *thr = (duk_hthread *) obj;
		duk_tval *p;

		DUK_D(DUK_DPRINT("  hthread"));
		DUK_D(DUK_DPRINT("  strict: %d", (int) thr->strict));
		DUK_D(DUK_DPRINT("  state: %d", (int) thr->state));

		DUK_D(DUK_DPRINT("  valstack_max: %d, callstack_max:%d, catchstack_max: %d",
		                 thr->valstack_max, thr->callstack_max, thr->catchstack_max));

		DUK_D(DUK_DPRINT("  callstack: ptr %p, size %d, top %d, preventcount %d, used size %d entries (%d bytes), alloc size %d entries (%d bytes)",
		                 (void *) thr->callstack,
		                 thr->callstack_size,
		                 thr->callstack_top,
		                 thr->callstack_preventcount,
		                 thr->callstack_top,
		                 thr->callstack_top * sizeof(duk_activation),
		                 thr->callstack_size,
		                 thr->callstack_size * sizeof(duk_activation)));

		DUK_DEBUG_SUMMARY_INIT();
		DUK_DEBUG_SUMMARY_CHAR('[');
		for (i = 0; i <= thr->callstack_size; i++) {
			if (i == thr->callstack_top) {
				DUK_DEBUG_SUMMARY_CHAR('|');
			}
			if (!thr->callstack) {
				DUK_DEBUG_SUMMARY_CHAR('@');
			} else if (i < thr->callstack_size) {
				if (i < thr->callstack_top) {
					/* tailcalling is nice to see immediately; other flags (e.g. strict)
					 * not that important.
					 */
					if (thr->callstack[i].flags & DUK_ACT_FLAG_TAILCALLED) {
						DUK_DEBUG_SUMMARY_CHAR('/');
					}
					DUK_DEBUG_SUMMARY_CHAR(duk__get_act_summary_char(&thr->callstack[i]));
				} else {
					DUK_DEBUG_SUMMARY_CHAR('.');
				}
			}
		}
		DUK_DEBUG_SUMMARY_CHAR(']');
		DUK_DEBUG_SUMMARY_FINISH();

		DUK_D(DUK_DPRINT("  valstack: ptr %p, end %p (%d), bottom %p (%d), top %p (%d), used size %d entries (%d bytes), alloc size %d entries (%d bytes)",
		                 (void *) thr->valstack,
		                 (void *) thr->valstack_end,
		                 (int) (thr->valstack_end - thr->valstack),
		                 (void *) thr->valstack_bottom,
		                 (int) (thr->valstack_bottom - thr->valstack),
		                 (void *) thr->valstack_top,
		                 (int) (thr->valstack_top - thr->valstack),
		                 (int) (thr->valstack_top - thr->valstack),
		                 (int) (thr->valstack_top - thr->valstack) * sizeof(duk_tval),
		                 (int) (thr->valstack_end - thr->valstack),
		                 (int) (thr->valstack_end - thr->valstack) * sizeof(duk_tval)));

		DUK_DEBUG_SUMMARY_INIT();
		DUK_DEBUG_SUMMARY_CHAR('[');
		p = thr->valstack;
		while (p <= thr->valstack_end) {
			i = (duk_uint_fast32_t) (p - thr->valstack);
			if (thr->callstack &&
			    thr->callstack_top > 0 &&
			    i == (duk_size_t) (thr->callstack + thr->callstack_top - 1)->idx_bottom) {
				DUK_DEBUG_SUMMARY_CHAR('>');
			}
			if (p == thr->valstack_top) {
				DUK_DEBUG_SUMMARY_CHAR('|');
			}
			if (p < thr->valstack_end) {
				if (p < thr->valstack_top) {
					DUK_DEBUG_SUMMARY_CHAR(duk__get_tval_summary_char(p));
				} else {
					/* XXX: safe printer for these?  would be nice, because
					 * we could visualize whether the values are in proper
					 * state.
					 */
					DUK_DEBUG_SUMMARY_CHAR('.');
				}
			}
			p++;
		}
		DUK_DEBUG_SUMMARY_CHAR(']');
		DUK_DEBUG_SUMMARY_FINISH();

		DUK_D(DUK_DPRINT("  catchstack: ptr %p, size %d, top %d, used size %d entries (%d bytes), alloc size %d entries (%d bytes)",
		                 (void *) thr->catchstack,
		                 thr->catchstack_size,
		                 thr->catchstack_top,
		                 thr->catchstack_top,
		                 thr->catchstack_top * sizeof(duk_catcher),
		                 thr->catchstack_size,
		                 thr->catchstack_size * sizeof(duk_catcher)));

		DUK_DEBUG_SUMMARY_INIT();
		DUK_DEBUG_SUMMARY_CHAR('[');
		for (i = 0; i <= thr->catchstack_size; i++) {
			if (i == thr->catchstack_top) {
				DUK_DEBUG_SUMMARY_CHAR('|');
			}
			if (!thr->catchstack) {
				DUK_DEBUG_SUMMARY_CHAR('@');
			} else if (i < thr->catchstack_size) {
				if (i < thr->catchstack_top) {
					DUK_DEBUG_SUMMARY_CHAR(duk__get_cat_summary_char(&thr->catchstack[i]));
				} else {
					DUK_DEBUG_SUMMARY_CHAR('.');
				}
			}
		}
		DUK_DEBUG_SUMMARY_CHAR(']');
		DUK_DEBUG_SUMMARY_FINISH();

		DUK_D(DUK_DPRINT("  resumer: ptr %p",
		                 (void *) thr->resumer));

#if 0  /* worth dumping? */
		for (i = 0; i < DUK_NUM_BUILTINS; i++) {
			DUK_D(DUK_DPRINT("  builtins[%d] -> %!@O", i, thr->builtins[i]));
		}
#endif
	}

	if (obj->p) {
		DUK_D(DUK_DPRINT("  props alloc size: %d",
		                 (int) DUK_HOBJECT_P_COMPUTE_SIZE(obj->e_size, obj->a_size, obj->h_size)));
	} else {
		DUK_D(DUK_DPRINT("  props alloc size: n/a"));
	}

	DUK_D(DUK_DPRINT("  prop entries:"));
	for (i = 0; i < obj->e_size; i++) {
		duk_hstring *k;
		duk_propvalue *v;

		k = DUK_HOBJECT_E_GET_KEY(obj, i);
		v = DUK_HOBJECT_E_GET_VALUE_PTR(obj, i);

		if (i >= obj->e_used) {
			DUK_D(DUK_DPRINT("    [%d]: UNUSED", i));
			continue;
		}

		if (!k) {
			DUK_D(DUK_DPRINT("    [%d]: NULL", i));
			continue;
		}

		if (DUK_HOBJECT_E_SLOT_IS_ACCESSOR(obj, i)) {
			DUK_D(DUK_DPRINT("    [%d]: [w=%d e=%d c=%d a=%d] %!O -> get:%p set:%p; get %!O; set %!O",
			                 i,
			                 DUK_HOBJECT_E_SLOT_IS_WRITABLE(obj, i),
			                 DUK_HOBJECT_E_SLOT_IS_ENUMERABLE(obj, i),
			                 DUK_HOBJECT_E_SLOT_IS_CONFIGURABLE(obj, i),
			                 DUK_HOBJECT_E_SLOT_IS_ACCESSOR(obj, i),
			                 k,
			                 (void *) v->a.get,
			                 (void *) v->a.set,
			                 (duk_heaphdr *) v->a.get,
			                 (duk_heaphdr *) v->a.set));
		} else {
			DUK_D(DUK_DPRINT("    [%d]: [w=%d e=%d c=%d a=%d] %!O -> %!T",
			                 i,
			                 DUK_HOBJECT_E_SLOT_IS_WRITABLE(obj, i),
			                 DUK_HOBJECT_E_SLOT_IS_ENUMERABLE(obj, i),
			                 DUK_HOBJECT_E_SLOT_IS_CONFIGURABLE(obj, i),
			                 DUK_HOBJECT_E_SLOT_IS_ACCESSOR(obj, i),
			                 k,
			                 &v->v));
		}
	}

	DUK_D(DUK_DPRINT("  array entries:"));
	for (i = 0; i < obj->a_size; i++) {
		DUK_D(DUK_DPRINT("    [%d]: [w=%d e=%d c=%d a=%d] %d -> %!T",
		                 i,
		                 1,  /* implicit attributes */
		                 1,
		                 1,
		                 0,
		                 i,
		                 DUK_HOBJECT_A_GET_VALUE_PTR(obj, i)));
	}

	DUK_D(DUK_DPRINT("  hash entries:"));
	for (i = 0; i < obj->h_size; i++) {
		duk_uint32_t t = DUK_HOBJECT_H_GET_INDEX(obj, i);
		if (t == DUK_HOBJECT_HASHIDX_UNUSED) {
			DUK_D(DUK_DPRINT("    [%d]: unused", i));
		} else if (t == DUK_HOBJECT_HASHIDX_DELETED) {
			DUK_D(DUK_DPRINT("    [%d]: deleted", i));
		} else {
			DUK_D(DUK_DPRINT("    [%d]: %d",
			                 i,
			                 (int) t));
		}
	}
}
Exemple #4
0
/*
 *  Returns non-zero if a key and/or value was enumerated, and:
 *
 *   [enum] -> [key]        (get_value == 0)
 *   [enum] -> [key value]  (get_value == 1)
 *
 *  Returns zero without pushing anything on the stack otherwise.
 */
duk_bool_t duk_hobject_enumerator_next(duk_context *ctx, duk_bool_t get_value) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_hobject *e;
	duk_hobject *enum_target;
	duk_hstring *res = NULL;
	duk_uint_fast32_t idx;
	duk_bool_t check_existence;

	DUK_ASSERT(ctx != NULL);

	/* [... enum] */

	e = duk_require_hobject(ctx, -1);

	/* XXX use get tval ptr, more efficient */
	duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INT_NEXT);
	idx = (duk_uint_fast32_t) duk_require_uint(ctx, -1);
	duk_pop(ctx);
	DUK_DDD(DUK_DDDPRINT("enumeration: index is: %ld", (long) idx));

	/* Enumeration keys are checked against the enumeration target (to see
	 * that they still exist).  In the proxy enumeration case _target will
	 * be the proxy, and checking key existence against the proxy is not
	 * required (or sensible, as the keys may be fully virtual).
	 */
	duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INT_TARGET);
	enum_target = duk_require_hobject(ctx, -1);
	DUK_ASSERT(enum_target != NULL);
#if defined(DUK_USE_ES6_PROXY)
	check_existence = (!DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(enum_target));
#else
	check_existence = 1;
#endif
	duk_pop(ctx);  /* still reachable */

	DUK_DDD(DUK_DDDPRINT("getting next enum value, enum_target=%!iO, enumerator=%!iT",
	                     (duk_heaphdr *) enum_target, (duk_tval *) duk_get_tval(ctx, -1)));

	/* no array part */
	for (;;) {
		duk_hstring *k;

		if (idx >= e->e_next) {
			DUK_DDD(DUK_DDDPRINT("enumeration: ran out of elements"));
			break;
		}

		/* we know these because enum objects are internally created */
		k = DUK_HOBJECT_E_GET_KEY(e, idx);
		DUK_ASSERT(k != NULL);
		DUK_ASSERT(!DUK_HOBJECT_E_SLOT_IS_ACCESSOR(e, idx));
		DUK_ASSERT(!DUK_TVAL_IS_UNDEFINED_UNUSED(&DUK_HOBJECT_E_GET_VALUE(e, idx).v));

		idx++;

		/* recheck that the property still exists */
		if (check_existence && !duk_hobject_hasprop_raw(thr, enum_target, k)) {
			DUK_DDD(DUK_DDDPRINT("property deleted during enumeration, skip"));
			continue;
		}

		DUK_DDD(DUK_DDDPRINT("enumeration: found element, key: %!O", (duk_heaphdr *) k));
		res = k;
		break;
	}

	DUK_DDD(DUK_DDDPRINT("enumeration: updating next index to %ld", (long) idx));

	duk_push_number(ctx, (double) idx);
	duk_put_prop_stridx(ctx, -2, DUK_STRIDX_INT_NEXT);

	/* [... enum] */

	if (res) {
		duk_push_hstring(ctx, res);
		if (get_value) {
			duk_push_hobject(ctx, enum_target);
			duk_dup(ctx, -2);      /* -> [... enum key enum_target key] */
			duk_get_prop(ctx, -2); /* -> [... enum key enum_target val] */
			duk_remove(ctx, -2);   /* -> [... enum key val] */
			duk_remove(ctx, -3);   /* -> [... key val] */
		} else {
			duk_remove(ctx, -2);   /* -> [... key] */
		}
		return 1;
	} else {
		duk_pop(ctx);  /* -> [...] */
		return 0;
	}
}
DUK_LOCAL void duk__print_hobject(duk__dprint_state *st, duk_hobject *h) {
	duk_fixedbuffer *fb = st->fb;
	duk_uint_fast32_t i;
	duk_tval *tv;
	duk_hstring *key;
	duk_bool_t first = 1;
	const char *brace1 = "{";
	const char *brace2 = "}";
	duk_bool_t pushed_loopstack = 0;

	if (duk_fb_is_full(fb)) {
		return;
	}

	duk__print_shared_heaphdr(st, &h->hdr);

	if (h && DUK_HOBJECT_HAS_ARRAY_PART(h)) {
		brace1 = "[";
		brace2 = "]";
	}

	if (!h) {
		duk_fb_put_cstring(fb, "NULL");
		goto finished;
	}

	if (st->depth >= st->depth_limit) {
		const char *subtype = "generic";

		if (DUK_HOBJECT_IS_COMPFUNC(h)) {
			subtype = "compfunc";
		} else if (DUK_HOBJECT_IS_NATFUNC(h)) {
			subtype = "natfunc";
		} else if (DUK_HOBJECT_IS_THREAD(h)) {
			subtype = "thread";
		} else if (DUK_HOBJECT_IS_BUFOBJ(h)) {
			subtype = "bufobj";
		} else if (DUK_HOBJECT_IS_ARRAY(h)) {
			subtype = "array";
		}
		duk_fb_sprintf(fb, "%sobject/%s %p%s", (const char *) brace1, subtype, (void *) h, (const char *) brace2);
		return;
	}

	for (i = 0; i < (duk_uint_fast32_t) st->loop_stack_index; i++) {
		if (st->loop_stack[i] == h) {
			duk_fb_sprintf(fb, "%sLOOP:%p%s", (const char *) brace1, (void *) h, (const char *) brace2);
			return;
		}
	}

	/* after this, return paths should 'goto finished' for decrement */
	st->depth++;

	if (st->loop_stack_index >= st->loop_stack_limit) {
		duk_fb_sprintf(fb, "%sOUT-OF-LOOP-STACK%s", (const char *) brace1, (const char *) brace2);
		goto finished;
	}
	st->loop_stack[st->loop_stack_index++] = h;
	pushed_loopstack = 1;

	/*
	 *  Notation: double underscore used for internal properties which are not
	 *  stored in the property allocation (e.g. '__valstack').
	 */

	duk_fb_put_cstring(fb, brace1);

	if (DUK_HOBJECT_GET_PROPS(NULL, h)) {
		duk_uint32_t a_limit;

		a_limit = DUK_HOBJECT_GET_ASIZE(h);
		if (st->internal) {
			/* dump all allocated entries, unused entries print as 'unused',
			 * note that these may extend beyond current 'length' and look
			 * a bit funny.
			 */
		} else {
			/* leave out trailing 'unused' elements */
			while (a_limit > 0) {
				tv = DUK_HOBJECT_A_GET_VALUE_PTR(NULL, h, a_limit - 1);
				if (!DUK_TVAL_IS_UNUSED(tv)) {
					break;
				}
				a_limit--;
			}
		}

		for (i = 0; i < a_limit; i++) {
			tv = DUK_HOBJECT_A_GET_VALUE_PTR(NULL, h, i);
			DUK__COMMA();
			duk__print_tval(st, tv);
		}
		for (i = 0; i < DUK_HOBJECT_GET_ENEXT(h); i++) {
			key = DUK_HOBJECT_E_GET_KEY(NULL, h, i);
			if (!key) {
				continue;
			}
			if (!st->internal && DUK_HSTRING_HAS_HIDDEN(key)) {
				continue;
			}
			DUK__COMMA();
			duk__print_hstring(st, key, 0);
			duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_COLON);
			if (DUK_HOBJECT_E_SLOT_IS_ACCESSOR(NULL, h, i)) {
				duk_fb_sprintf(fb, "[get:%p,set:%p]",
				               (void *) DUK_HOBJECT_E_GET_VALUE(NULL, h, i).a.get,
				               (void *) DUK_HOBJECT_E_GET_VALUE(NULL, h, i).a.set);
			} else {
				tv = &DUK_HOBJECT_E_GET_VALUE(NULL, h, i).v;
				duk__print_tval(st, tv);
			}
			if (st->heavy) {
				duk_fb_sprintf(fb, "<%02lx>", (unsigned long) DUK_HOBJECT_E_GET_FLAGS(NULL, h, i));
			}
		}
	}
	if (st->internal) {
		if (DUK_HOBJECT_HAS_EXTENSIBLE(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__extensible:true");
		}
		if (DUK_HOBJECT_HAS_CONSTRUCTABLE(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__constructable:true");
		}
		if (DUK_HOBJECT_HAS_BOUNDFUNC(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__boundfunc:true");
		}
		if (DUK_HOBJECT_HAS_COMPFUNC(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__compfunc:true");
		}
		if (DUK_HOBJECT_HAS_NATFUNC(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__natfunc:true");
		}
		if (DUK_HOBJECT_HAS_BUFOBJ(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__bufobj:true");
		}
		if (DUK_HOBJECT_HAS_THREAD(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__thread:true");
		}
		if (DUK_HOBJECT_HAS_ARRAY_PART(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__array_part:true");
		}
		if (DUK_HOBJECT_HAS_STRICT(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__strict:true");
		}
		if (DUK_HOBJECT_HAS_NOTAIL(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__notail:true");
		}
		if (DUK_HOBJECT_HAS_NEWENV(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__newenv:true");
		}
		if (DUK_HOBJECT_HAS_NAMEBINDING(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__namebinding:true");
		}
		if (DUK_HOBJECT_HAS_CREATEARGS(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__createargs:true");
		}
		if (DUK_HOBJECT_HAS_ENVRECCLOSED(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__envrecclosed:true");
		}
		if (DUK_HOBJECT_HAS_EXOTIC_ARRAY(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__exotic_array:true");
		}
		if (DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__exotic_stringobj:true");
		}
		if (DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__exotic_arguments:true");
		}
		if (DUK_HOBJECT_HAS_EXOTIC_DUKFUNC(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__exotic_dukfunc:true");
		}
		if (DUK_HOBJECT_IS_BUFOBJ(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__exotic_bufobj:true");
		}
		if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(h)) {
			DUK__COMMA(); duk_fb_sprintf(fb, "__exotic_proxyobj:true");
		}
	}

	if (st->internal && DUK_HOBJECT_IS_ARRAY(h)) {
		duk_harray *a = (duk_harray *) h;
		DUK__COMMA(); duk_fb_sprintf(fb, "__length:%ld", (long) a->length);
		DUK__COMMA(); duk_fb_sprintf(fb, "__length_nonwritable:%ld", (long) a->length_nonwritable);
	} else if (st->internal && DUK_HOBJECT_IS_COMPFUNC(h)) {
		duk_hcompfunc *f = (duk_hcompfunc *) h;
		DUK__COMMA(); duk_fb_put_cstring(fb, "__data:");
		duk__print_hbuffer(st, (duk_hbuffer *) DUK_HCOMPFUNC_GET_DATA(NULL, f));
		DUK__COMMA(); duk_fb_put_cstring(fb, "__lexenv:"); duk__print_hobject(st, DUK_HCOMPFUNC_GET_LEXENV(NULL, f));
		DUK__COMMA(); duk_fb_put_cstring(fb, "__varenv:"); duk__print_hobject(st, DUK_HCOMPFUNC_GET_VARENV(NULL, f));
		DUK__COMMA(); duk_fb_sprintf(fb, "__nregs:%ld", (long) f->nregs);
		DUK__COMMA(); duk_fb_sprintf(fb, "__nargs:%ld", (long) f->nargs);
#if defined(DUK_USE_DEBUGGER_SUPPORT)
		DUK__COMMA(); duk_fb_sprintf(fb, "__start_line:%ld", (long) f->start_line);
		DUK__COMMA(); duk_fb_sprintf(fb, "__end_line:%ld", (long) f->end_line);
#endif
		DUK__COMMA(); duk_fb_put_cstring(fb, "__data:");
		duk__print_hbuffer(st, (duk_hbuffer *) DUK_HCOMPFUNC_GET_DATA(NULL, f));
	} else if (st->internal && DUK_HOBJECT_IS_NATFUNC(h)) {
		duk_hnatfunc *f = (duk_hnatfunc *) h;
		DUK__COMMA(); duk_fb_sprintf(fb, "__func:");
		duk_fb_put_funcptr(fb, (duk_uint8_t *) &f->func, sizeof(f->func));
		DUK__COMMA(); duk_fb_sprintf(fb, "__nargs:%ld", (long) f->nargs);
		DUK__COMMA(); duk_fb_sprintf(fb, "__magic:%ld", (long) f->magic);
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
	} else if (st->internal && DUK_HOBJECT_IS_BUFOBJ(h)) {
		duk_hbufobj *b = (duk_hbufobj *) h;
		DUK__COMMA(); duk_fb_sprintf(fb, "__buf:");
		duk__print_hbuffer(st, (duk_hbuffer *) b->buf);
		DUK__COMMA(); duk_fb_sprintf(fb, "__buf_prop:");
		duk__print_hobject(st, (duk_hobject *) b->buf_prop);
		DUK__COMMA(); duk_fb_sprintf(fb, "__offset:%ld", (long) b->offset);
		DUK__COMMA(); duk_fb_sprintf(fb, "__length:%ld", (long) b->length);
		DUK__COMMA(); duk_fb_sprintf(fb, "__shift:%ld", (long) b->shift);
		DUK__COMMA(); duk_fb_sprintf(fb, "__elemtype:%ld", (long) b->elem_type);
#endif
	} else if (st->internal && DUK_HOBJECT_IS_THREAD(h)) {
		duk_hthread *t = (duk_hthread *) h;
		DUK__COMMA(); duk_fb_sprintf(fb, "__strict:%ld", (long) t->strict);
		DUK__COMMA(); duk_fb_sprintf(fb, "__state:%ld", (long) t->state);
		DUK__COMMA(); duk_fb_sprintf(fb, "__unused1:%ld", (long) t->unused1);
		DUK__COMMA(); duk_fb_sprintf(fb, "__unused2:%ld", (long) t->unused2);
		DUK__COMMA(); duk_fb_sprintf(fb, "__valstack_max:%ld", (long) t->valstack_max);
		DUK__COMMA(); duk_fb_sprintf(fb, "__callstack_max:%ld", (long) t->callstack_max);
		DUK__COMMA(); duk_fb_sprintf(fb, "__catchstack_max:%ld", (long) t->catchstack_max);
		DUK__COMMA(); duk_fb_sprintf(fb, "__valstack:%p", (void *) t->valstack);
		DUK__COMMA(); duk_fb_sprintf(fb, "__valstack_end:%p/%ld", (void *) t->valstack_end, (long) (t->valstack_end - t->valstack));
		DUK__COMMA(); duk_fb_sprintf(fb, "__valstack_bottom:%p/%ld", (void *) t->valstack_bottom, (long) (t->valstack_bottom - t->valstack));
		DUK__COMMA(); duk_fb_sprintf(fb, "__valstack_top:%p/%ld", (void *) t->valstack_top, (long) (t->valstack_top - t->valstack));
		DUK__COMMA(); duk_fb_sprintf(fb, "__catchstack:%p", (void *) t->catchstack);
		DUK__COMMA(); duk_fb_sprintf(fb, "__catchstack_size:%ld", (long) t->catchstack_size);
		DUK__COMMA(); duk_fb_sprintf(fb, "__catchstack_top:%ld", (long) t->catchstack_top);
		DUK__COMMA(); duk_fb_sprintf(fb, "__resumer:"); duk__print_hobject(st, (duk_hobject *) t->resumer);
		/* XXX: print built-ins array? */

	}
#if defined(DUK_USE_REFERENCE_COUNTING)
	if (st->internal) {
		DUK__COMMA(); duk_fb_sprintf(fb, "__refcount:%lu", (unsigned long) DUK_HEAPHDR_GET_REFCOUNT((duk_heaphdr *) h));
	}
#endif
	if (st->internal) {
		DUK__COMMA(); duk_fb_sprintf(fb, "__class:%ld", (long) DUK_HOBJECT_GET_CLASS_NUMBER(h));
	}

	DUK__COMMA(); duk_fb_sprintf(fb, "__heapptr:%p", (void *) h);  /* own pointer */

	/* prototype should be last, for readability */
	if (DUK_HOBJECT_GET_PROTOTYPE(NULL, h)) {
		if (st->follow_proto) {
			DUK__COMMA(); duk_fb_put_cstring(fb, "__prototype:"); duk__print_hobject(st, DUK_HOBJECT_GET_PROTOTYPE(NULL, h));
		} else {
			DUK__COMMA(); duk_fb_sprintf(fb, "__prototype:%p", (void *) DUK_HOBJECT_GET_PROTOTYPE(NULL, h));
		}
	}

	duk_fb_put_cstring(fb, brace2);

#if defined(DUK_USE_HOBJECT_HASH_PART)
	if (st->heavy && DUK_HOBJECT_GET_HSIZE(h) > 0) {
		duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_LANGLE);
		for (i = 0; i < DUK_HOBJECT_GET_HSIZE(h); i++) {
			duk_uint_t h_idx = DUK_HOBJECT_H_GET_INDEX(NULL, h, i);
			if (i > 0) {
				duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_COMMA);
			}
			if (h_idx == DUK_HOBJECT_HASHIDX_UNUSED) {
				duk_fb_sprintf(fb, "u");
			} else if (h_idx == DUK_HOBJECT_HASHIDX_DELETED) {
				duk_fb_sprintf(fb, "d");
			} else {
				duk_fb_sprintf(fb, "%ld", (long) h_idx);
			}
		}
		duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_RANGLE);
	}
#endif

 finished:
	st->depth--;
	if (pushed_loopstack) {
		st->loop_stack_index--;
		st->loop_stack[st->loop_stack_index] = NULL;
	}
}