C++ DUK_DPRINT函数代码示例

DUK_LOCAL void duk__refcount_run_torture_finalizer(duk_hthread *thr, duk_hobject *obj) {
	duk_context *ctx;
	duk_int_t rc;

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(obj != NULL);
	ctx = (duk_context *) thr;

	/* Avoid fake finalization for the duk__refcount_fake_finalizer function
	 * itself, otherwise we're in infinite recursion.
	 */
	if (DUK_HOBJECT_HAS_NATFUNC(obj)) {
		if (((duk_hnatfunc *) obj)->func == duk__refcount_fake_finalizer) {
			DUK_DD(DUK_DDPRINT("avoid fake torture finalizer for duk__refcount_fake_finalizer itself"));
			return;
		}
	}
	/* Avoid fake finalization when callstack limit has been reached.
	 * Otherwise a callstack limit error will be created, then refzero'ed,
	 * and we're in an infinite loop.
	 */
	if (thr->heap->call_recursion_depth >= thr->heap->call_recursion_limit ||
	    thr->callstack_size + 2 * DUK_CALLSTACK_GROW_STEP >= thr->callstack_max /*approximate*/) {
		DUK_D(DUK_DPRINT("call recursion depth reached, avoid fake torture finalizer"));
		return;
	}

	/* Run fake finalizer.  Avoid creating new refzero queue entries
	 * so that we are not forced into a forever loop.
	 */
	duk_push_c_function(ctx, duk__refcount_fake_finalizer, 1 /*nargs*/);
	duk_push_hobject(ctx, obj);
	rc = duk_pcall(ctx, 1);
	DUK_UNREF(rc);  /* ignored */
	duk_pop(ctx);
}

DUK_LOCAL void duk__duplicate_ram_global_object(duk_hthread *thr) {
	duk_context *ctx;
	duk_hobject *h1;
#if defined(DUK_USE_ROM_GLOBAL_CLONE)
	duk_hobject *h2;
	duk_uint8_t *props;
	duk_size_t alloc_size;
#endif

	ctx = (duk_context *) thr;

	/* XXX: refactor into internal helper, duk_clone_hobject() */

#if defined(DUK_USE_ROM_GLOBAL_INHERIT)
	/* Inherit from ROM-based global object: less RAM usage, less transparent. */
	duk_push_object_helper(ctx,
	                       DUK_HOBJECT_FLAG_EXTENSIBLE |
	                       DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_GLOBAL),
	                       DUK_BIDX_GLOBAL);
	h1 = duk_get_hobject(ctx, -1);
	DUK_ASSERT(h1 != NULL);
#elif defined(DUK_USE_ROM_GLOBAL_CLONE)
	/* Clone the properties of the ROM-based global object to create a
	 * fully RAM-based global object.  Uses more memory than the inherit
	 * model but more compliant.
	 */
	duk_push_object_helper(ctx,
	                       DUK_HOBJECT_FLAG_EXTENSIBLE |
	                       DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_GLOBAL),
	                       DUK_BIDX_OBJECT_PROTOTYPE);
	h1 = duk_get_hobject(ctx, -1);
	DUK_ASSERT(h1 != NULL);
	h2 = thr->builtins[DUK_BIDX_GLOBAL];
	DUK_ASSERT(h2 != NULL);

	/* Copy the property table verbatim; this handles attributes etc.
	 * For ROM objects it's not necessary (or possible) to update
	 * refcounts so leave them as is.
	 */
	alloc_size = DUK_HOBJECT_P_ALLOC_SIZE(h2);
	DUK_ASSERT(alloc_size > 0);
	props = DUK_ALLOC(thr->heap, alloc_size);
	if (!props) {
		DUK_ERROR_ALLOC_FAILED(thr);
		return;
	}
	DUK_ASSERT(DUK_HOBJECT_GET_PROPS(thr->heap, h2) != NULL);
	DUK_MEMCPY((void *) props, (const void *) DUK_HOBJECT_GET_PROPS(thr->heap, h2), alloc_size);

	/* XXX: keep property attributes or tweak them here?
	 * Properties will now be non-configurable even when they're
	 * normally configurable for the global object.
	 */

	DUK_ASSERT(DUK_HOBJECT_GET_PROPS(thr->heap, h1) == NULL);
	DUK_HOBJECT_SET_PROPS(thr->heap, h1, props);
	DUK_HOBJECT_SET_ESIZE(h1, DUK_HOBJECT_GET_ESIZE(h2));
	DUK_HOBJECT_SET_ENEXT(h1, DUK_HOBJECT_GET_ENEXT(h2));
	DUK_HOBJECT_SET_ASIZE(h1, DUK_HOBJECT_GET_ASIZE(h2));
	DUK_HOBJECT_SET_HSIZE(h1, DUK_HOBJECT_GET_HSIZE(h2));
#else
#error internal error in defines
#endif

	duk_hobject_compact_props(thr, h1);
	DUK_ASSERT(thr->builtins[DUK_BIDX_GLOBAL] != NULL);
	DUK_ASSERT(!DUK_HEAPHDR_NEEDS_REFCOUNT_UPDATE((duk_heaphdr *) thr->builtins[DUK_BIDX_GLOBAL]));  /* no need to decref */
	thr->builtins[DUK_BIDX_GLOBAL] = h1;
	DUK_HOBJECT_INCREF(thr, h1);
	DUK_D(DUK_DPRINT("duplicated global object: %!O", h1));


	/* Create a fresh object environment for the global scope.  This is
	 * needed so that the global scope points to the newly created RAM-based
	 * global object.
	 */
	duk_push_object_helper(ctx,
	                       DUK_HOBJECT_FLAG_EXTENSIBLE |
	                       DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_OBJENV),
	                       -1);  /* no prototype */
	h1 = duk_get_hobject(ctx, -1);
	DUK_ASSERT(h1 != NULL);
	duk_dup(ctx, -2);
	duk_dup(ctx, -1);  /* -> [ ... new_global new_globalenv new_global new_global ] */
	duk_xdef_prop_stridx(thr, -3, DUK_STRIDX_INT_TARGET, DUK_PROPDESC_FLAGS_NONE);
	duk_xdef_prop_stridx(thr, -2, DUK_STRIDX_INT_THIS, DUK_PROPDESC_FLAGS_NONE);  /* always provideThis=true */

	duk_hobject_compact_props(thr, h1);
	DUK_ASSERT(thr->builtins[DUK_BIDX_GLOBAL_ENV] != NULL);
	DUK_ASSERT(!DUK_HEAPHDR_NEEDS_REFCOUNT_UPDATE((duk_heaphdr *) thr->builtins[DUK_BIDX_GLOBAL_ENV]));  /* no need to decref */
	thr->builtins[DUK_BIDX_GLOBAL_ENV] = h1;
	DUK_HOBJECT_INCREF(thr, h1);
	DUK_D(DUK_DPRINT("duplicated global env: %!O", h1));

	duk_pop_2(ctx);
}

DUK_INTERNAL void duk_err_longjmp(duk_hthread *thr) {
	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(thr->heap != NULL);

	DUK_DD(DUK_DDPRINT("longjmp error: type=%d iserror=%d value1=%!T value2=%!T",
	                   (int) thr->heap->lj.type, (int) thr->heap->lj.iserror,
	                   &thr->heap->lj.value1, &thr->heap->lj.value2));

	/* Prevent finalizer execution during error handling.  All error
	 * handling sites will process pending finalizers once error handling
	 * is complete and we're ready for the side effects.  Does not prevent
	 * refzero freeing or mark-and-sweep during error handling.
	 *
	 * NOTE: when we come here some calling code may have used DECREF
	 * NORZ macros without an explicit DUK_REFZERO_CHECK_xxx() call.
	 * We don't want to do it here because it would just check for
	 * pending finalizers and we prevent that explicitly.  Instead,
	 * the error catcher will run the finalizers once error handling
	 * is complete.
	 */

	DUK_ASSERT_LJSTATE_SET(thr->heap);

	thr->heap->pf_prevent_count++;
	DUK_ASSERT(thr->heap->pf_prevent_count != 0);  /* Wrap. */

#if defined(DUK_USE_ASSERTIONS)
	/* XXX: set this immediately when longjmp state is set */
	DUK_ASSERT(thr->heap->error_not_allowed == 0);  /* Detect error within critical section. */
	thr->heap->error_not_allowed = 1;
#endif

	DUK_DD(DUK_DDPRINT("about to longjmp, pf_prevent_count=%ld", (long) thr->heap->pf_prevent_count));

#if !defined(DUK_USE_CPP_EXCEPTIONS)
	/* If we don't have a jmpbuf_ptr, there is little we can do except
	 * cause a fatal error.  The caller's expectation is that we never
	 * return.
	 *
	 * With C++ exceptions we now just propagate an uncaught error
	 * instead of invoking the fatal error handler.  Because there's
	 * a dummy jmpbuf for C++ exceptions now, this could be changed.
	 */
	if (!thr->heap->lj.jmpbuf_ptr) {
		DUK_D(DUK_DPRINT("uncaught error: type=%d iserror=%d value1=%!T value2=%!T",
		                 (int) thr->heap->lj.type, (int) thr->heap->lj.iserror,
		                 &thr->heap->lj.value1, &thr->heap->lj.value2));

#if defined(DUK_USE_PREFER_SIZE)
		duk__uncaught_minimal(thr);
#else
		duk__uncaught_error_aware(thr);
#endif
		DUK_UNREACHABLE();
	}
#endif  /* DUK_USE_CPP_EXCEPTIONS */

#if defined(DUK_USE_CPP_EXCEPTIONS)
	{
		duk_internal_exception exc;  /* dummy */
		throw exc;
	}
#else  /* DUK_USE_CPP_EXCEPTIONS */
	DUK_LONGJMP(thr->heap->lj.jmpbuf_ptr->jb);
#endif  /* DUK_USE_CPP_EXCEPTIONS */

	DUK_UNREACHABLE();
}

DUK_INTERNAL void *duk_heap_mem_realloc_indirect(duk_heap *heap, duk_mem_getptr cb, void *ud, duk_size_t newsize) {
	void *res;
	duk_bool_t rc;
	duk_small_int_t i;

	DUK_ASSERT(heap != NULL);
	DUK_ASSERT_DISABLE(newsize >= 0);

	/*
	 *  Voluntary periodic GC (if enabled)
	 */

	DUK__VOLUNTARY_PERIODIC_GC(heap);

	/*
	 *  First attempt
	 */

#if defined(DUK_USE_GC_TORTURE)
	/* simulate alloc failure on every realloc (except when mark-and-sweep is running) */
	if (!DUK_HEAP_HAS_MARKANDSWEEP_RUNNING(heap)) {
		DUK_DDD(DUK_DDDPRINT("gc torture enabled, pretend that first indirect realloc attempt fails"));
		res = NULL;
		DUK_UNREF(res);
		goto skip_attempt;
	}
#endif
	res = heap->realloc_func(heap->heap_udata, cb(heap, ud), newsize);
	if (res || newsize == 0) {
		/* for zero size allocations NULL is allowed */
		return res;
	}
#if defined(DUK_USE_GC_TORTURE)
 skip_attempt:
#endif

	DUK_D(DUK_DPRINT("first indirect realloc attempt failed, attempt to gc and retry"));

	/*
	 *  Avoid a GC if GC is already running.  See duk_heap_mem_alloc().
	 */

	if (DUK_HEAP_HAS_MARKANDSWEEP_RUNNING(heap)) {
		DUK_D(DUK_DPRINT("duk_heap_mem_realloc_indirect() failed, gc in progress (gc skipped), alloc size %ld", (long) newsize));
		return NULL;
	}

	/*
	 *  Retry with several GC attempts.  Initial attempts are made without
	 *  emergency mode; later attempts use emergency mode which minimizes
	 *  memory allocations forcibly.
	 */

	for (i = 0; i < DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_LIMIT; i++) {
		duk_small_uint_t flags;

#if defined(DUK_USE_ASSERTIONS)
		void *ptr_pre;  /* ptr before mark-and-sweep */
		void *ptr_post;
#endif

#if defined(DUK_USE_ASSERTIONS)
		ptr_pre = cb(heap, ud);
#endif
		flags = 0;
		if (i >= DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_EMERGENCY_LIMIT - 1) {
			flags |= DUK_MS_FLAG_EMERGENCY;
		}

		rc = duk_heap_mark_and_sweep(heap, flags);
		DUK_UNREF(rc);
#if defined(DUK_USE_ASSERTIONS)
		ptr_post = cb(heap, ud);
		if (ptr_pre != ptr_post) {
			/* useful for debugging */
			DUK_DD(DUK_DDPRINT("note: base pointer changed by mark-and-sweep: %p -> %p",
			                   (void *) ptr_pre, (void *) ptr_post));
		}
#endif

		/* Note: key issue here is to re-lookup the base pointer on every attempt.
		 * The pointer being reallocated may change after every mark-and-sweep.
		 */

		res = heap->realloc_func(heap->heap_udata, cb(heap, ud), newsize);
		if (res || newsize == 0) {
			DUK_D(DUK_DPRINT("duk_heap_mem_realloc_indirect() succeeded after gc (pass %ld), alloc size %ld",
			                 (long) (i + 1), (long) newsize));
			return res;
		}
	}

	DUK_D(DUK_DPRINT("duk_heap_mem_realloc_indirect() failed even after gc, alloc size %ld", (long) newsize));
	return NULL;
}

duk_heap *duk_heap_alloc(duk_alloc_function alloc_func,
                         duk_realloc_function realloc_func,
                         duk_free_function free_func,
                         void *alloc_udata,
                         duk_fatal_function fatal_func) {
	duk_heap *res = NULL;

	DUK_D(DUK_DPRINT("allocate heap"));

	/* Debug dump type sizes */
#ifdef DUK_USE_DEBUG
	duk__dump_type_sizes();
#endif

	/* If selftests enabled, run them as early as possible. */
#ifdef DUK_USE_SELF_TESTS
	DUK_D(DUK_DPRINT("running self tests"));
	duk_selftest_run_tests();
	DUK_D(DUK_DPRINT("self tests passed"));
#endif

#ifdef DUK_USE_COMPUTED_NAN
	do {
		/* Workaround for some exotic platforms where NAN is missing
		 * and the expression (0.0 / 0.0) does NOT result in a NaN.
		 * Such platforms use the global 'duk_computed_nan' which must
		 * be initialized at runtime.  Use 'volatile' to ensure that
		 * the compiler will actually do the computation and not try
		 * to do constant folding which might result in the original
		 * problem.
		 */
		volatile double dbl1 = 0.0;
		volatile double dbl2 = 0.0;
		duk_computed_nan = dbl1 / dbl2;
	} while (0);
#endif

#ifdef DUK_USE_COMPUTED_INFINITY
	do {
		/* Similar workaround for INFINITY. */
		volatile double dbl1 = 1.0;
		volatile double dbl2 = 0.0;
		duk_computed_infinity = dbl1 / dbl2;
	} while (0);
#endif

	/* use a raw call, all macros expect the heap to be initialized */
	res = (duk_heap *) alloc_func(alloc_udata, sizeof(duk_heap));
	if (!res) {
		goto error;
	}

	/* zero everything */
	DUK_MEMZERO(res, sizeof(*res));

	/* explicit NULL inits */
#ifdef DUK_USE_EXPLICIT_NULL_INIT
	res->alloc_udata = NULL;
	res->heap_allocated = NULL;
#ifdef DUK_USE_REFERENCE_COUNTING
	res->refzero_list = NULL;
	res->refzero_list_tail = NULL;
#endif
#ifdef DUK_USE_MARK_AND_SWEEP
	res->finalize_list = NULL;
#endif
	res->heap_thread = NULL;
	res->curr_thread = NULL;
	res->heap_object = NULL;
	res->log_buffer = NULL;
	res->st = NULL;
	{
		int i;
	        for (i = 0; i < DUK_HEAP_NUM_STRINGS; i++) {
        	        res->strs[i] = NULL;
	        }
	}
#endif

	/* initialize the structure, roughly in order */
	res->alloc_func = alloc_func;
	res->realloc_func = realloc_func;
	res->free_func = free_func;
	res->alloc_udata = alloc_udata;
	res->fatal_func = fatal_func;

	/* res->mark_and_sweep_trigger_counter == 0 -> now causes immediate GC; which is OK */

	res->call_recursion_depth = 0;
	res->call_recursion_limit = DUK_HEAP_DEFAULT_CALL_RECURSION_LIMIT;

	/* FIXME: use the pointer as a seed for now: mix in time at least */

	/* cast through C99 intptr_t to avoid GCC warning:
	 *
	 *   warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
	 */
	res->hash_seed = (duk_uint32_t) (duk_intptr_t) res;
	res->rnd_state = (duk_uint32_t) (duk_intptr_t) res;

//.........这里部分代码省略.........

/* Allocate a new duk_hbuffer of a certain type and return a pointer to it
 * (NULL on error).  Write buffer data pointer to 'out_bufdata' (only if
 * allocation successful).
 */
DUK_INTERNAL duk_hbuffer *duk_hbuffer_alloc(duk_heap *heap, duk_size_t size, duk_small_uint_t flags, void **out_bufdata) {
	duk_hbuffer *res = NULL;
	duk_size_t header_size;
	duk_size_t alloc_size;

	DUK_ASSERT(heap != NULL);
	DUK_ASSERT(out_bufdata != NULL);

	DUK_DDD(DUK_DDDPRINT("allocate hbuffer"));

	/* Size sanity check.  Should not be necessary because caller is
	 * required to check this, but we don't want to cause a segfault
	 * if the size wraps either in duk_size_t computation or when
	 * storing the size in a 16-bit field.
	 */
	if (size > DUK_HBUFFER_MAX_BYTELEN) {
		DUK_D(DUK_DPRINT("hbuffer alloc failed: size too large: %ld", (long) size));
		return NULL;  /* no need to write 'out_bufdata' */
	}

	if (flags & DUK_BUF_FLAG_EXTERNAL) {
		header_size = sizeof(duk_hbuffer_external);
		alloc_size = sizeof(duk_hbuffer_external);
	} else if (flags & DUK_BUF_FLAG_DYNAMIC) {
		header_size = sizeof(duk_hbuffer_dynamic);
		alloc_size = sizeof(duk_hbuffer_dynamic);
	} else {
		header_size = sizeof(duk_hbuffer_fixed);
		alloc_size = sizeof(duk_hbuffer_fixed) + size;
		DUK_ASSERT(alloc_size >= sizeof(duk_hbuffer_fixed));  /* no wrapping */
	}

	res = (duk_hbuffer *) DUK_ALLOC(heap, alloc_size);
	if (DUK_UNLIKELY(res == NULL)) {
		goto alloc_error;
	}

	/* zero everything unless requested not to do so */
#if defined(DUK_USE_ZERO_BUFFER_DATA)
	DUK_MEMZERO((void *) res,
	            (flags & DUK_BUF_FLAG_NOZERO) ? header_size : alloc_size);
#else
	DUK_MEMZERO((void *) res, header_size);
#endif

	if (flags & DUK_BUF_FLAG_EXTERNAL) {
		duk_hbuffer_external *h;
		h = (duk_hbuffer_external *) res;
		DUK_UNREF(h);
		*out_bufdata = NULL;
#if defined(DUK_USE_EXPLICIT_NULL_INIT)
#if defined(DUK_USE_HEAPPTR16)
/* the compressed pointer is zeroed which maps to NULL, so nothing to do. */
#else
		DUK_HBUFFER_EXTERNAL_SET_DATA_PTR(heap, h, NULL);
#endif
#endif
		DUK_ASSERT(DUK_HBUFFER_EXTERNAL_GET_DATA_PTR(heap, h) == NULL);
	} else if (flags & DUK_BUF_FLAG_DYNAMIC) {
		duk_hbuffer_dynamic *h = (duk_hbuffer_dynamic *) res;
		void *ptr;

		if (size > 0) {
			DUK_ASSERT(!(flags & DUK_BUF_FLAG_EXTERNAL));  /* alloc external with size zero */
			DUK_DDD(DUK_DDDPRINT("dynamic buffer with nonzero size, alloc actual buffer"));
#if defined(DUK_USE_ZERO_BUFFER_DATA)
			ptr = DUK_ALLOC_ZEROED(heap, size);
#else
			ptr = DUK_ALLOC(heap, size);
#endif
			if (DUK_UNLIKELY(ptr == NULL)) {
				/* Because size > 0, NULL check is correct */
				goto alloc_error;
			}
			*out_bufdata = ptr;

			DUK_HBUFFER_DYNAMIC_SET_DATA_PTR(heap, h, ptr);
		} else {
			*out_bufdata = NULL;
#if defined(DUK_USE_EXPLICIT_NULL_INIT)
#if defined(DUK_USE_HEAPPTR16)
/* the compressed pointer is zeroed which maps to NULL, so nothing to do. */
#else
			DUK_HBUFFER_DYNAMIC_SET_DATA_PTR(heap, h, NULL);
#endif
#endif
			DUK_ASSERT(DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(heap, h) == NULL);
		}
	} else {
		*out_bufdata = (void *) ((duk_hbuffer_fixed *) res + 1);
	}

	DUK_HBUFFER_SET_SIZE(res, size);

	DUK_HEAPHDR_SET_TYPE(&res->hdr, DUK_HTYPE_BUFFER);
	if (flags & DUK_BUF_FLAG_DYNAMIC) {
//.........这里部分代码省略.........

DUK_LOCAL void duk__mark_hobject(duk_heap *heap, duk_hobject *h) {
	duk_uint_fast32_t i;

	DUK_DDD(DUK_DDDPRINT("duk__mark_hobject: %p", (void *) h));

	DUK_ASSERT(h);

	/* XXX: use advancing pointers instead of index macros -> faster and smaller? */

	for (i = 0; i < (duk_uint_fast32_t) DUK_HOBJECT_GET_ENEXT(h); i++) {
		duk_hstring *key = DUK_HOBJECT_E_GET_KEY(heap, h, i);
		if (!key) {
			continue;
		}
		duk__mark_heaphdr(heap, (duk_heaphdr *) key);
		if (DUK_HOBJECT_E_SLOT_IS_ACCESSOR(heap, h, i)) {
			duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_HOBJECT_E_GET_VALUE_PTR(heap, h, i)->a.get);
			duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_HOBJECT_E_GET_VALUE_PTR(heap, h, i)->a.set);
		} else {
			duk__mark_tval(heap, &DUK_HOBJECT_E_GET_VALUE_PTR(heap, h, i)->v);
		}
	}

	for (i = 0; i < (duk_uint_fast32_t) DUK_HOBJECT_GET_ASIZE(h); i++) {
		duk__mark_tval(heap, DUK_HOBJECT_A_GET_VALUE_PTR(heap, h, i));
	}

	/* hash part is a 'weak reference' and does not contribute */

	duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_HOBJECT_GET_PROTOTYPE(heap, h));

	/* XXX: rearrange bits to allow a switch case to be used here? */
	/* XXX: add a fast path for objects (and arrays)? */
	/* DUK_HOBJECT_IS_ARRAY(h): needs no special handling now as there are
	 * no extra fields in need of marking.
	 */
	if (DUK_HOBJECT_IS_COMPFUNC(h)) {
		duk_hcompfunc *f = (duk_hcompfunc *) h;
		duk_tval *tv, *tv_end;
		duk_hobject **fn, **fn_end;

		/* 'data' is reachable through every compiled function which
		 * contains a reference.
		 */

		duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_HCOMPFUNC_GET_DATA(heap, f));
		duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_HCOMPFUNC_GET_LEXENV(heap, f));
		duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_HCOMPFUNC_GET_VARENV(heap, f));

		if (DUK_HCOMPFUNC_GET_DATA(heap, f) != NULL) {
			tv = DUK_HCOMPFUNC_GET_CONSTS_BASE(heap, f);
			tv_end = DUK_HCOMPFUNC_GET_CONSTS_END(heap, f);
			while (tv < tv_end) {
				duk__mark_tval(heap, tv);
				tv++;
			}

			fn = DUK_HCOMPFUNC_GET_FUNCS_BASE(heap, f);
			fn_end = DUK_HCOMPFUNC_GET_FUNCS_END(heap, f);
			while (fn < fn_end) {
				duk__mark_heaphdr(heap, (duk_heaphdr *) *fn);
				fn++;
			}
		} else {
			/* May happen in some out-of-memory corner cases. */
			DUK_D(DUK_DPRINT("duk_hcompfunc 'data' is NULL, skipping marking"));
		}
	} else if (DUK_HOBJECT_IS_NATFUNC(h)) {
		duk_hnatfunc *f = (duk_hnatfunc *) h;
		DUK_UNREF(f);
		/* nothing to mark */
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
	} else if (DUK_HOBJECT_IS_BUFOBJ(h)) {
		duk_hbufobj *b = (duk_hbufobj *) h;
		duk__mark_heaphdr(heap, (duk_heaphdr *) b->buf);
		duk__mark_heaphdr(heap, (duk_heaphdr *) b->buf_prop);
#endif  /* DUK_USE_BUFFEROBJECT_SUPPORT */
	} else if (DUK_HOBJECT_IS_THREAD(h)) {
		duk_hthread *t = (duk_hthread *) h;
		duk_tval *tv;

		tv = t->valstack;
		while (tv < t->valstack_top) {
			duk__mark_tval(heap, tv);
			tv++;
		}

		for (i = 0; i < (duk_uint_fast32_t) t->callstack_top; i++) {
			duk_activation *act = t->callstack + i;
			duk__mark_heaphdr(heap, (duk_heaphdr *) DUK_ACT_GET_FUNC(act));
			duk__mark_heaphdr(heap, (duk_heaphdr *) act->var_env);
			duk__mark_heaphdr(heap, (duk_heaphdr *) act->lex_env);
#if defined(DUK_USE_NONSTD_FUNC_CALLER_PROPERTY)
			duk__mark_heaphdr(heap, (duk_heaphdr *) act->prev_caller);
#endif
		}

#if 0  /* nothing now */
		for (i = 0; i < (duk_uint_fast32_t) t->catchstack_top; i++) {
			duk_catcher *cat = t->catchstack + i;
//.........这里部分代码省略.........

DUK_LOCAL void duk__dump_type_sizes(void) {
	DUK_D(DUK_DPRINT("sizeof()"));

	/* basic platform types */
	DUK__DUMPSZ(char);
	DUK__DUMPSZ(short);
	DUK__DUMPSZ(int);
	DUK__DUMPSZ(long);
	DUK__DUMPSZ(double);
	DUK__DUMPSZ(void *);
	DUK__DUMPSZ(size_t);

	/* basic types from duk_features.h */
	DUK__DUMPSZ(duk_uint8_t);
	DUK__DUMPSZ(duk_int8_t);
	DUK__DUMPSZ(duk_uint16_t);
	DUK__DUMPSZ(duk_int16_t);
	DUK__DUMPSZ(duk_uint32_t);
	DUK__DUMPSZ(duk_int32_t);
	DUK__DUMPSZ(duk_uint64_t);
	DUK__DUMPSZ(duk_int64_t);
	DUK__DUMPSZ(duk_uint_least8_t);
	DUK__DUMPSZ(duk_int_least8_t);
	DUK__DUMPSZ(duk_uint_least16_t);
	DUK__DUMPSZ(duk_int_least16_t);
	DUK__DUMPSZ(duk_uint_least32_t);
	DUK__DUMPSZ(duk_int_least32_t);
#if defined(DUK_USE_64BIT_OPS)
	DUK__DUMPSZ(duk_uint_least64_t);
	DUK__DUMPSZ(duk_int_least64_t);
#endif
	DUK__DUMPSZ(duk_uint_fast8_t);
	DUK__DUMPSZ(duk_int_fast8_t);
	DUK__DUMPSZ(duk_uint_fast16_t);
	DUK__DUMPSZ(duk_int_fast16_t);
	DUK__DUMPSZ(duk_uint_fast32_t);
	DUK__DUMPSZ(duk_int_fast32_t);
#if defined(DUK_USE_64BIT_OPS)
	DUK__DUMPSZ(duk_uint_fast64_t);
	DUK__DUMPSZ(duk_int_fast64_t);
#endif
	DUK__DUMPSZ(duk_uintptr_t);
	DUK__DUMPSZ(duk_intptr_t);
	DUK__DUMPSZ(duk_uintmax_t);
	DUK__DUMPSZ(duk_intmax_t);
	DUK__DUMPSZ(duk_double_t);

	/* important chosen base types */
	DUK__DUMPSZ(duk_int_t);
	DUK__DUMPSZ(duk_uint_t);
	DUK__DUMPSZ(duk_int_fast_t);
	DUK__DUMPSZ(duk_uint_fast_t);
	DUK__DUMPSZ(duk_small_int_t);
	DUK__DUMPSZ(duk_small_uint_t);
	DUK__DUMPSZ(duk_small_int_fast_t);
	DUK__DUMPSZ(duk_small_uint_fast_t);

	/* some derived types */
	DUK__DUMPSZ(duk_codepoint_t);
	DUK__DUMPSZ(duk_ucodepoint_t);
	DUK__DUMPSZ(duk_idx_t);
	DUK__DUMPSZ(duk_errcode_t);
	DUK__DUMPSZ(duk_uarridx_t);

	/* tval */
	DUK__DUMPSZ(duk_double_union);
	DUK__DUMPSZ(duk_tval);

	/* structs from duk_forwdecl.h */
	DUK__DUMPSZ(duk_jmpbuf);
	DUK__DUMPSZ(duk_heaphdr);
	DUK__DUMPSZ(duk_heaphdr_string);
	DUK__DUMPSZ(duk_hstring);
	DUK__DUMPSZ(duk_hstring_external);
	DUK__DUMPSZ(duk_hobject);
	DUK__DUMPSZ(duk_hcompiledfunction);
	DUK__DUMPSZ(duk_hnativefunction);
	DUK__DUMPSZ(duk_hthread);
	DUK__DUMPSZ(duk_hbuffer);
	DUK__DUMPSZ(duk_hbuffer_fixed);
	DUK__DUMPSZ(duk_hbuffer_dynamic);
	DUK__DUMPSZ(duk_propaccessor);
	DUK__DUMPSZ(duk_propvalue);
	DUK__DUMPSZ(duk_propdesc);
	DUK__DUMPSZ(duk_heap);
#if defined(DUK_USE_STRTAB_CHAIN)
	DUK__DUMPSZ(duk_strtab_entry);
#endif
	DUK__DUMPSZ(duk_activation);
	DUK__DUMPSZ(duk_catcher);
	DUK__DUMPSZ(duk_strcache);
	DUK__DUMPSZ(duk_ljstate);
	DUK__DUMPSZ(duk_fixedbuffer);
	DUK__DUMPSZ(duk_bitdecoder_ctx);
	DUK__DUMPSZ(duk_bitencoder_ctx);
	DUK__DUMPSZ(duk_token);
	DUK__DUMPSZ(duk_re_token);
	DUK__DUMPSZ(duk_lexer_point);
	DUK__DUMPSZ(duk_lexer_ctx);
	DUK__DUMPSZ(duk_compiler_instr);
//.........这里部分代码省略.........

DUK_INTERNAL void duk_err_create_and_throw(duk_hthread *thr, duk_errcode_t code, const char *msg, const char *filename, duk_int_t line) {
#else
DUK_INTERNAL void duk_err_create_and_throw(duk_hthread *thr, duk_errcode_t code) {
#endif
	duk_context *ctx = (duk_context *) thr;
	duk_bool_t double_error = thr->heap->handling_error;

#ifdef DUK_USE_VERBOSE_ERRORS
	DUK_DD(DUK_DDPRINT("duk_err_create_and_throw(): code=%ld, msg=%s, filename=%s, line=%ld",
	                   (long) code, (const char *) msg,
	                   (const char *) filename, (long) line));
#else
	DUK_DD(DUK_DDPRINT("duk_err_create_and_throw(): code=%ld", (long) code));
#endif

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(ctx != NULL);

	thr->heap->handling_error = 1;

	/*
	 *  Create and push an error object onto the top of stack.
	 *  If a "double error" occurs, use a fixed error instance
	 *  to avoid further trouble.
	 */

	/* XXX: if attempt to push beyond allocated valstack, this double fault
	 * handling fails miserably.  We should really write the double error
	 * directly to thr->heap->lj.value1 and avoid valstack use entirely.
	 */

	if (double_error) {
		if (thr->builtins[DUK_BIDX_DOUBLE_ERROR]) {
			DUK_D(DUK_DPRINT("double fault detected -> push built-in fixed 'double error' instance"));
			duk_push_hobject_bidx(ctx, DUK_BIDX_DOUBLE_ERROR);
		} else {
			DUK_D(DUK_DPRINT("double fault detected; there is no built-in fixed 'double error' instance "
			                 "-> push the error code as a number"));
			duk_push_int(ctx, (duk_int_t) code);
		}
	} else {
		/* Error object is augmented at its creation here. */
		duk_require_stack(ctx, 1);
		/* XXX: unnecessary '%s' formatting here, but cannot use
		 * 'msg' as a format string directly.
		 */
#ifdef DUK_USE_VERBOSE_ERRORS
		duk_push_error_object_raw(ctx,
		                          code | DUK_ERRCODE_FLAG_NOBLAME_FILELINE,
		                          filename,
		                          line,
		                          "%s",
		                          (const char *) msg);
#else
		duk_push_error_object_raw(ctx,
		                          code | DUK_ERRCODE_FLAG_NOBLAME_FILELINE,
		                          NULL,
		                          0,
		                          NULL);
#endif
	}

	/*
	 *  Augment error (throw time), unless alloc/double error
	 */

	if (double_error || code == DUK_ERR_ALLOC_ERROR) {
		DUK_D(DUK_DPRINT("alloc or double error: skip throw augmenting to avoid further trouble"));
	} else {
#if defined(DUK_USE_AUGMENT_ERROR_THROW)
		DUK_DDD(DUK_DDDPRINT("THROW ERROR (INTERNAL): %!iT (before throw augment)",
		                     (duk_tval *) duk_get_tval(ctx, -1)));
		duk_err_augment_error_throw(thr);
#endif
	}

	/*
	 *  Finally, longjmp
	 */

	thr->heap->handling_error = 0;

	duk_err_setup_heap_ljstate(thr, DUK_LJ_TYPE_THROW);

	DUK_DDD(DUK_DDDPRINT("THROW ERROR (INTERNAL): %!iT, %!iT (after throw augment)",
	                     (duk_tval *) &thr->heap->lj.value1, (duk_tval *) &thr->heap->lj.value2));

	duk_err_longjmp(thr);
	DUK_UNREACHABLE();
}

void *duk_heap_mem_realloc(duk_heap *heap, void *ptr, size_t newsize) {
	void *res;
	int rc;
	int i;

	DUK_ASSERT(heap != NULL);
	/* ptr may be NULL */
	DUK_ASSERT_DISABLE(newsize >= 0);

	/*
	 *  Voluntary periodic GC (if enabled)
	 */

	DUK__VOLUNTARY_PERIODIC_GC(heap);

	/*
	 *  First attempt
	 */

#ifdef DUK_USE_GC_TORTURE
	/* simulate alloc failure on every realloc (except when mark-and-sweep is running) */
	if (!DUK_HEAP_HAS_MARKANDSWEEP_RUNNING(heap)) {
		DUK_DDD(DUK_DDDPRINT("gc torture enabled, pretend that first realloc attempt fails"));
		res = NULL;
		DUK_UNREF(res);
		goto skip_attempt;
	}
#endif
	res = heap->realloc_func(heap->alloc_udata, ptr, newsize);
	if (res || newsize == 0) {
		/* for zero size allocations NULL is allowed */
		return res;
	}
#ifdef DUK_USE_GC_TORTURE
 skip_attempt:
#endif

	DUK_D(DUK_DPRINT("first realloc attempt failed, attempt to gc and retry"));

	/*
	 *  Avoid a GC if GC is already running.  See duk_heap_mem_alloc().
	 */

	if (DUK_HEAP_HAS_MARKANDSWEEP_RUNNING(heap)) {
		DUK_D(DUK_DPRINT("duk_heap_mem_realloc() failed, gc in progress (gc skipped), alloc size %d", newsize));
		return NULL;
	}

	/*
	 *  Retry with several GC attempts.  Initial attempts are made without
	 *  emergency mode; later attempts use emergency mode which minimizes
	 *  memory allocations forcibly.
	 */

	for (i = 0; i < DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_LIMIT; i++) {
		int flags;

		flags = 0;
		if (i >= DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_EMERGENCY_LIMIT - 1) {
			flags |= DUK_MS_FLAG_EMERGENCY;
		}

		rc = duk_heap_mark_and_sweep(heap, flags);
		DUK_UNREF(rc);

		res = heap->realloc_func(heap->alloc_udata, ptr, newsize);
		if (res) {
			DUK_D(DUK_DPRINT("duk_heap_mem_realloc() succeeded after gc (pass %d), alloc size %d",
			                 i + 1, newsize));
			return res;
		}
	}

	DUK_D(DUK_DPRINT("duk_heap_mem_realloc() failed even after gc, alloc size %d", newsize));
	return NULL;
}

DUK_INTERNAL void duk_regexp_compile(duk_hthread *thr) {
	duk_context *ctx = (duk_context *) thr;
	duk_re_compiler_ctx re_ctx;
	duk_lexer_point lex_point;
	duk_hstring *h_pattern;
	duk_hstring *h_flags;
	duk__re_disjunction_info ign_disj;

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(ctx != NULL);

	/*
	 *  Args validation
	 */

	/* TypeError if fails */
	h_pattern = duk_require_hstring(ctx, -2);
	h_flags = duk_require_hstring(ctx, -1);

	/*
	 *  Create normalized 'source' property (E5 Section 15.10.3).
	 */

	/* [ ... pattern flags ] */

	duk__create_escaped_source(thr, -2);

	/* [ ... pattern flags escaped_source ] */

	/*
	 *  Init compilation context
	 */

	/* [ ... pattern flags escaped_source buffer ] */

	DUK_MEMZERO(&re_ctx, sizeof(re_ctx));
	DUK_LEXER_INITCTX(&re_ctx.lex);  /* duplicate zeroing, expect for (possible) NULL inits */
	re_ctx.thr = thr;
	re_ctx.lex.thr = thr;
	re_ctx.lex.input = DUK_HSTRING_GET_DATA(h_pattern);
	re_ctx.lex.input_length = DUK_HSTRING_GET_BYTELEN(h_pattern);
	re_ctx.lex.token_limit = DUK_RE_COMPILE_TOKEN_LIMIT;
	re_ctx.recursion_limit = DUK_USE_REGEXP_COMPILER_RECLIMIT;
	re_ctx.re_flags = duk__parse_regexp_flags(thr, h_flags);

	DUK_BW_INIT_PUSHBUF(thr, &re_ctx.bw, DUK__RE_INITIAL_BUFSIZE);

	DUK_DD(DUK_DDPRINT("regexp compiler ctx initialized, flags=0x%08lx, recursion_limit=%ld",
	                   (unsigned long) re_ctx.re_flags, (long) re_ctx.recursion_limit));

	/*
	 *  Init lexer
	 */

	lex_point.offset = 0;  /* expensive init, just want to fill window */
	lex_point.line = 1;
	DUK_LEXER_SETPOINT(&re_ctx.lex, &lex_point);

	/*
	 *  Compilation
	 */

	DUK_D(DUK_DPRINT("starting regexp compilation"));

	duk__append_u32(&re_ctx, DUK_REOP_SAVE);
	duk__append_u32(&re_ctx, 0);
	duk__parse_disjunction(&re_ctx, 1 /*expect_eof*/, &ign_disj);
	duk__append_u32(&re_ctx, DUK_REOP_SAVE);
	duk__append_u32(&re_ctx, 1);
	duk__append_u32(&re_ctx, DUK_REOP_MATCH);

	/*
	 *  Check for invalid backreferences; note that it is NOT an error
	 *  to back-reference a capture group which has not yet been introduced
	 *  in the pattern (as in /\1(foo)/); in fact, the backreference will
	 *  always match!  It IS an error to back-reference a capture group
	 *  which will never be introduced in the pattern.  Thus, we can check
	 *  for such references only after parsing is complete.
	 */

	if (re_ctx.highest_backref > re_ctx.captures) {
		DUK_ERROR(thr, DUK_ERR_SYNTAX_ERROR, DUK_STR_INVALID_BACKREFS);
	}

	/*
	 *  Emit compiled regexp header: flags, ncaptures
	 *  (insertion order inverted on purpose)
	 */

	duk__insert_u32(&re_ctx, 0, (re_ctx.captures + 1) * 2);
	duk__insert_u32(&re_ctx, 0, re_ctx.re_flags);

	/* [ ... pattern flags escaped_source buffer ] */

	DUK_BW_COMPACT(thr, &re_ctx.bw);
	duk_to_string(ctx, -1);  /* coerce to string */

	/* [ ... pattern flags escaped_source bytecode ] */

	/*
//.........这里部分代码省略.........

DUK_LOCAL void duk__free_stringtable(duk_heap *heap) {
	duk_uint_fast32_t i;

	/* strings are only tracked by stringtable */
#if defined(DUK_USE_HEAPPTR16)
	if (heap->strtable16) {
#else
	if (heap->strtable) {
#endif
		for (i = 0; i < (duk_uint_fast32_t) heap->st_size; i++) {
			duk_hstring *e;
#if defined(DUK_USE_HEAPPTR16)
			e = (duk_hstring *) DUK_USE_HEAPPTR_DEC16(heap->strtable16[i]);
#else
			e = heap->strtable[i];
#endif
			if (e == NULL || e == DUK_STRTAB_DELETED_MARKER(heap)) {
				continue;
			}
			DUK_ASSERT(e != NULL);

			/* strings may have inner refs (extdata) in some cases */
			duk_free_hstring_inner(heap, (duk_hstring *) e);

			DUK_DDD(DUK_DDDPRINT("FINALFREE (string): %!iO",
			                     (duk_heaphdr *) e));
			DUK_FREE(heap, e);
#if 0  /* not strictly necessary */
			heap->strtable[i] = NULL;
#endif
		}
#if defined(DUK_USE_HEAPPTR16)
		DUK_FREE(heap, heap->strtable16);
#else
		DUK_FREE(heap, heap->strtable);
#endif
#if 0  /* not strictly necessary */
		heap->strtable = NULL;
#endif
	}
}

DUK_LOCAL void duk__free_run_finalizers(duk_heap *heap) {
	duk_hthread *thr;
	duk_heaphdr *curr;
#ifdef DUK_USE_DEBUG
	duk_size_t count_obj = 0;
#endif

	DUK_ASSERT(heap != NULL);
	DUK_ASSERT(heap->heap_thread != NULL);
#ifdef DUK_USE_REFERENCE_COUNTING
	DUK_ASSERT(heap->refzero_list == NULL);  /* refzero not running -> must be empty */
#endif
#ifdef DUK_USE_MARK_AND_SWEEP
	DUK_ASSERT(heap->finalize_list == NULL);  /* mark-and-sweep not running -> must be empty */
#endif

	/* XXX: here again finalizer thread is the heap_thread which needs
	 * to be coordinated with finalizer thread fixes.
	 */
	thr = heap->heap_thread;
	DUK_ASSERT(thr != NULL);

	curr = heap->heap_allocated;
	while (curr) {
		if (DUK_HEAPHDR_GET_TYPE(curr) == DUK_HTYPE_OBJECT) {
			/* Only objects in heap_allocated may have finalizers.  Check that
			 * the object itself has a _Finalizer property so that we don't
			 * execute finalizers for e.g. Proxy objects.
			 */
			DUK_ASSERT(thr != NULL);
			DUK_ASSERT(curr != NULL);

			if (duk_hobject_hasprop_raw(thr, (duk_hobject *) curr, DUK_HTHREAD_STRING_INT_FINALIZER(thr))) {
				duk_hobject_run_finalizer(thr, (duk_hobject *) curr);
			}
#ifdef DUK_USE_DEBUG
			count_obj++;
#endif
		}
		curr = DUK_HEAPHDR_GET_NEXT(curr);
	}

	/* Note: count includes all objects, not only those with an actual finalizer. */
#ifdef DUK_USE_DEBUG
	DUK_D(DUK_DPRINT("checked %ld objects for finalizers before freeing heap", (long) count_obj));
#endif
}

DUK_LOCAL void duk__sweep_stringtable_probe(duk_heap *heap, duk_size_t *out_count_keep) {
	duk_hstring *h;
	duk_uint_fast32_t i;
#ifdef DUK_USE_DEBUG
	duk_size_t count_free = 0;
#endif
	duk_size_t count_keep = 0;

	DUK_DD(DUK_DDPRINT("duk__sweep_stringtable: %p", (void *) heap));

	for (i = 0; i < heap->st_size; i++) {
#if defined(DUK_USE_HEAPPTR16)
		h = (duk_hstring *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, heap->strtable16[i]);
#else
		h = heap->strtable[i];
#endif
		if (h == NULL || h == DUK_STRTAB_DELETED_MARKER(heap)) {
			continue;
		} else if (DUK_HEAPHDR_HAS_REACHABLE((duk_heaphdr *) h)) {
			DUK_HEAPHDR_CLEAR_REACHABLE((duk_heaphdr *) h);
			count_keep++;
			continue;
		}

#ifdef DUK_USE_DEBUG
		count_free++;
#endif

#if defined(DUK_USE_REFERENCE_COUNTING)
		/* Non-zero refcounts should not happen for unreachable strings,
		 * because we refcount finalize all unreachable objects which
		 * should have decreased unreachable string refcounts to zero
		 * (even for cycles).
		 */
		DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT((duk_heaphdr *) h) == 0);
#endif

		DUK_DDD(DUK_DDDPRINT("sweep string, not reachable: %p", (void *) h));

		/* deal with weak references first */
		duk_heap_strcache_string_remove(heap, (duk_hstring *) h);

		/* remove the string (mark DELETED), could also call
		 * duk_heap_string_remove() but that would be slow and
		 * pointless because we already know the slot.
		 */
#if defined(DUK_USE_HEAPPTR16)
		heap->strtable16[i] = heap->heapptr_deleted16;
#else
		heap->strtable[i] = DUK_STRTAB_DELETED_MARKER(heap);
#endif

		/* free inner references (these exist e.g. when external
		 * strings are enabled)
		 */
		duk_free_hstring_inner(heap, (duk_hstring *) h);

		/* finally free the struct itself */
		DUK_FREE(heap, h);
	}

#ifdef DUK_USE_DEBUG
	DUK_D(DUK_DPRINT("mark-and-sweep sweep stringtable: %ld freed, %ld kept",
	                 (long) count_free, (long) count_keep));
#endif
	*out_count_keep = count_keep;
}

DUK_INTERNAL void duk_hthread_create_builtin_objects(duk_hthread *thr) {
	duk_context *ctx = (duk_context *) thr;
	duk_bitdecoder_ctx bd_ctx;
	duk_bitdecoder_ctx *bd = &bd_ctx;  /* convenience */
	duk_hobject *h;
	duk_small_uint_t i, j;

	DUK_D(DUK_DPRINT("INITBUILTINS BEGIN"));

	DUK_MEMZERO(&bd_ctx, sizeof(bd_ctx));
	bd->data = (const duk_uint8_t *) duk_builtins_data;
	bd->length = (duk_size_t) DUK_BUILTINS_DATA_LENGTH;

	/*
	 *  First create all built-in bare objects on the empty valstack.
	 *  During init, their indices will correspond to built-in indices.
	 *
	 *  Built-ins will be reachable from both valstack and thr->builtins.
	 */

	/* XXX: there is no need to resize valstack because builtin count
	 * is much less than the default space; assert for it.
	 */

	DUK_DD(DUK_DDPRINT("create empty built-ins"));
	DUK_ASSERT_TOP(ctx, 0);
	for (i = 0; i < DUK_NUM_BUILTINS; i++) {
		duk_small_uint_t class_num;
		duk_small_int_t len = -1;  /* must be signed */

		class_num = (duk_small_uint_t) duk_bd_decode(bd, DUK__CLASS_BITS);
		len = (duk_small_int_t) duk_bd_decode_flagged(bd, DUK__LENGTH_PROP_BITS, (duk_int32_t) -1 /*def_value*/);

		if (class_num == DUK_HOBJECT_CLASS_FUNCTION) {
			duk_small_uint_t natidx;
			duk_small_uint_t stridx;
			duk_int_t c_nargs;  /* must hold DUK_VARARGS */
			duk_c_function c_func;
			duk_int16_t magic;

			DUK_DDD(DUK_DDDPRINT("len=%ld", (long) len));
			DUK_ASSERT(len >= 0);

			natidx = (duk_small_uint_t) duk_bd_decode(bd, DUK__NATIDX_BITS);
			stridx = (duk_small_uint_t) duk_bd_decode(bd, DUK__STRIDX_BITS);
			c_func = duk_bi_native_functions[natidx];

			c_nargs = (duk_small_uint_t) duk_bd_decode_flagged(bd, DUK__NARGS_BITS, len /*def_value*/);
			if (c_nargs == DUK__NARGS_VARARGS_MARKER) {
				c_nargs = DUK_VARARGS;
			}

			/* XXX: set magic directly here? (it could share the c_nargs arg) */
			duk_push_c_function_noexotic(ctx, c_func, c_nargs);

			h = duk_require_hobject(ctx, -1);
			DUK_ASSERT(h != NULL);

			/* Currently all built-in native functions are strict.
			 * duk_push_c_function() now sets strict flag, so
			 * assert for it.
			 */
			DUK_ASSERT(DUK_HOBJECT_HAS_STRICT(h));

			/* XXX: function properties */

			duk_push_hstring_stridx(ctx, stridx);
			duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_NAME, DUK_PROPDESC_FLAGS_NONE);

			/* Almost all global level Function objects are constructable
			 * but not all: Function.prototype is a non-constructable,
			 * callable Function.
			 */
			if (duk_bd_decode_flag(bd)) {
				DUK_ASSERT(DUK_HOBJECT_HAS_CONSTRUCTABLE(h));
			} else {
				DUK_HOBJECT_CLEAR_CONSTRUCTABLE(h);
			}

			/* Cast converts magic to 16-bit signed value */
			magic = (duk_int16_t) duk_bd_decode_flagged(bd, DUK__MAGIC_BITS, 0 /*def_value*/);
			((duk_hnativefunction *) h)->magic = magic;
		} else {
			/* XXX: ARRAY_PART for Array prototype? */

			duk_push_object_helper(ctx,
			                       DUK_HOBJECT_FLAG_EXTENSIBLE,
			                       -1);  /* no prototype or class yet */

			h = duk_require_hobject(ctx, -1);
			DUK_ASSERT(h != NULL);
		}

		DUK_HOBJECT_SET_CLASS_NUMBER(h, class_num);

		thr->builtins[i] = h;
		DUK_HOBJECT_INCREF(thr, &h->hdr);

		if (len >= 0) {
			/*
//.........这里部分代码省略.........

void duk_hthread_create_builtin_objects(duk_hthread *thr) {
	duk_context *ctx = (duk_context *) thr;
	duk_bitdecoder_ctx bd_ctx;
	duk_bitdecoder_ctx *bd = &bd_ctx;  /* convenience */
	duk_hobject *h;
	int i, j;

	DUK_DPRINT("INITBUILTINS BEGIN");

	DUK_MEMZERO(&bd_ctx, sizeof(bd_ctx));
	bd->data = (const duk_uint8_t *) duk_builtins_data;
	bd->length = (duk_size_t) DUK_BUILTINS_DATA_LENGTH;

	/*
	 *  First create all built-in bare objects on the empty valstack.
	 *  During init, their indices will correspond to built-in indices.
	 *
	 *  Built-ins will be reachable from both valstack and thr->builtins.
	 */

	/* XXX: there is no need to resize valstack because builtin count
	 * is much less than the default space; assert for it.
	 */

	DUK_DDPRINT("create empty built-ins");
	DUK_ASSERT_TOP(ctx, 0);
	for (i = 0; i < DUK_NUM_BUILTINS; i++) {
		int class_num;
		int len = -1;

		class_num = duk_bd_decode(bd, DUK__CLASS_BITS);
		len = duk_bd_decode_flagged(bd, DUK__LENGTH_PROP_BITS, (duk_int32_t) -1 /*def_value*/);

		if (class_num == DUK_HOBJECT_CLASS_FUNCTION) {
			int natidx;
			int stridx;
			int c_nargs;
			duk_c_function c_func;
			duk_int16_t magic;

			DUK_DDDPRINT("len=%d", len);
			DUK_ASSERT(len >= 0);

			natidx = duk_bd_decode(bd, DUK__NATIDX_BITS);
			stridx = duk_bd_decode(bd, DUK__STRIDX_BITS);
			c_func = duk_bi_native_functions[natidx];

			c_nargs = duk_bd_decode_flagged(bd, DUK__NARGS_BITS, len /*def_value*/);
			if (c_nargs == DUK__NARGS_VARARGS_MARKER) {
				c_nargs = DUK_VARARGS;
			}

			/* FIXME: set magic directly here? (it could share the c_nargs arg) */
			duk_push_c_function_nospecial(ctx, c_func, c_nargs);

			h = duk_require_hobject(ctx, -1);
			DUK_ASSERT(h != NULL);

			/* Currently all built-in native functions are strict.
			 * duk_push_c_function() now sets strict flag, so
			 * assert for it.
			 */
			DUK_ASSERT(DUK_HOBJECT_HAS_STRICT(h));

			/* FIXME: function properties */

			duk_push_hstring_stridx(ctx, stridx);
			duk_def_prop_stridx(ctx, -2, DUK_STRIDX_NAME, DUK_PROPDESC_FLAGS_NONE);

			/* Almost all global level Function objects are constructable
			 * but not all: Function.prototype is a non-constructable,
			 * callable Function.
			 */
			if (duk_bd_decode_flag(bd)) {
				DUK_ASSERT(DUK_HOBJECT_HAS_CONSTRUCTABLE(h));
			} else {
				DUK_HOBJECT_CLEAR_CONSTRUCTABLE(h);
			}

			/* Cast converts magic to 16-bit signed value */
			magic = (duk_int16_t) duk_bd_decode_flagged(bd, DUK__MAGIC_BITS, 0 /*def_value*/);
			((duk_hnativefunction *) h)->magic = magic;
		} else {
			/* FIXME: ARRAY_PART for Array prototype? */

			duk_push_object_helper(ctx,
			                       DUK_HOBJECT_FLAG_EXTENSIBLE,
			                       -1);  /* no prototype or class yet */

			h = duk_require_hobject(ctx, -1);
			DUK_ASSERT(h != NULL);
		}

		DUK_HOBJECT_SET_CLASS_NUMBER(h, class_num);

		thr->builtins[i] = h;
		DUK_HOBJECT_INCREF(thr, &h->hdr);

		if (len >= 0) {
			/*
//.........这里部分代码省略.........