C++ DUK_HSTRING_GET_BYTELEN函数代码示例

			/* Overflow, relevant mainly when listlen is 16 bits. */
			return 1;  /* fail */
		}

		new_lst = (duk_hstring **) DUK_REALLOC(heap, e->u.strlist, sizeof(duk_hstring *) * (e->listlen + 1));
		if (new_lst == NULL) {
			return 1;  /* fail */
		}
		new_lst[e->listlen++] = h;
		e->u.strlist = new_lst;
	}
	return 0;
}
#endif  /* DUK_USE_HEAPPTR16 */

#if defined(DUK_USE_HEAPPTR16)
DUK_LOCAL duk_hstring *duk__find_matching_string_chain(duk_heap *heap, const duk_uint8_t *str, duk_uint32_t blen, duk_uint32_t strhash) {
	duk_small_uint_t slotidx;
	duk_strtab_entry *e;
	duk_uint16_t *lst;
	duk_size_t i, n;
	duk_uint16_t null16 = heap->heapptr_null16;

	DUK_ASSERT(heap != NULL);

	slotidx = strhash % DUK_STRTAB_CHAIN_SIZE;
	DUK_ASSERT(slotidx < DUK_STRTAB_CHAIN_SIZE);

	e = heap->strtable + slotidx;
	if (e->listlen == 0) {
		if (e->u.str16 != null16) {
			duk_hstring *h = (duk_hstring *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, e->u.str16);
			DUK_ASSERT(h != NULL);
			if (DUK_HSTRING_GET_BYTELEN(h) == blen &&
			    DUK_MEMCMP((const void *) str, (const void *) DUK_HSTRING_GET_DATA(h), (size_t) blen) == 0) {
				return h;
			}
		}
	} else {
		DUK_ASSERT(e->u.strlist16 != null16);
		lst = (duk_uint16_t *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, e->u.strlist16);
		DUK_ASSERT(lst != NULL);
		for (i = 0, n = e->listlen; i < n; i++) {
			if (lst[i] != null16) {
				duk_hstring *h = (duk_hstring *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, lst[i]);
				DUK_ASSERT(h != NULL);
				if (DUK_HSTRING_GET_BYTELEN(h) == blen &&
				    DUK_MEMCMP((const void *) str, (const void *) DUK_HSTRING_GET_DATA(h), (size_t) blen) == 0) {
					return h;
				}
			}
		}
	}

	return NULL;
}
#else  /* DUK_USE_HEAPPTR16 */
DUK_LOCAL duk_hstring *duk__find_matching_string_chain(duk_heap *heap, const duk_uint8_t *str, duk_uint32_t blen, duk_uint32_t strhash) {
	duk_small_uint_t slotidx;
	duk_strtab_entry *e;
	duk_hstring **lst;
	duk_size_t i, n;

	DUK_ASSERT(heap != NULL);

	slotidx = strhash % DUK_STRTAB_CHAIN_SIZE;
	DUK_ASSERT(slotidx < DUK_STRTAB_CHAIN_SIZE);

	e = heap->strtable + slotidx;
	if (e->listlen == 0) {
		if (e->u.str != NULL &&
	           DUK_HSTRING_GET_BYTELEN(e->u.str) == blen &&
	           DUK_MEMCMP((const void *) str, (const void *) DUK_HSTRING_GET_DATA(e->u.str), (size_t) blen) == 0) {
			return e->u.str;
		}
	} else {
		DUK_ASSERT(e->u.strlist != NULL);
		lst = e->u.strlist;
		for (i = 0, n = e->listlen; i < n; i++) {
			if (lst[i] != NULL &&
		           DUK_HSTRING_GET_BYTELEN(lst[i]) == blen &&
		           DUK_MEMCMP((const void *) str, (const void *) DUK_HSTRING_GET_DATA(lst[i]), (size_t) blen) == 0) {
				return lst[i];
			}
		}
	}

	return NULL;
}

DUK_INTERNAL duk_ucodepoint_t duk_hstring_char_code_at_raw(duk_hthread *thr, duk_hstring *h, duk_uint_t pos) {
	duk_uint32_t boff;
	const duk_uint8_t *p, *p_start, *p_end;
	duk_ucodepoint_t cp;

	/* Caller must check character offset to be inside the string. */
	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(h != NULL);
	DUK_ASSERT_DISABLE(pos >= 0);  /* unsigned */
	DUK_ASSERT(pos < (duk_uint_t) DUK_HSTRING_GET_CHARLEN(h));

	boff = duk_heap_strcache_offset_char2byte(thr, h, (duk_uint32_t) pos);
	DUK_DDD(DUK_DDDPRINT("charCodeAt: pos=%ld -> boff=%ld, str=%!O",
	                     (long) pos, (long) boff, (duk_heaphdr *) h));
	DUK_ASSERT_DISABLE(boff >= 0);
	DUK_ASSERT(boff < DUK_HSTRING_GET_BYTELEN(h));

	p_start = DUK_HSTRING_GET_DATA(h);
	p_end = p_start + DUK_HSTRING_GET_BYTELEN(h);
	p = p_start + boff;
	DUK_DDD(DUK_DDDPRINT("p_start=%p, p_end=%p, p=%p",
	                     (void *) p_start, (void *) p_end, (void *) p));

	/* This may throw an error though not for valid E5 strings. */
	cp = duk_unicode_decode_xutf8_checked(thr, &p, p_start, p_end);
	return cp;
}

DUK_INTERNAL duk_ret_t duk_bi_string_prototype_locale_compare(duk_context *ctx) {
	duk_hstring *h1;
	duk_hstring *h2;
	duk_size_t h1_len, h2_len, prefix_len;
	duk_small_int_t ret = 0;
	duk_small_int_t rc;

	/* The current implementation of localeCompare() is simply a codepoint
	 * by codepoint comparison, implemented with a simple string compare
	 * because UTF-8 should preserve codepoint ordering (assuming valid
	 * shortest UTF-8 encoding).
	 *
	 * The specification requires that the return value must be related
	 * to the sort order: e.g. negative means that 'this' comes before
	 * 'that' in sort order.  We assume an ascending sort order.
	 */

	/* XXX: could share code with duk_js_ops.c, duk_js_compare_helper */

	h1 = duk_push_this_coercible_to_string(ctx);
	DUK_ASSERT(h1 != NULL);

	h2 = duk_to_hstring(ctx, 0);
	DUK_ASSERT(h2 != NULL);

	h1_len = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h1);
	h2_len = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h2);
	prefix_len = (h1_len <= h2_len ? h1_len : h2_len);

	/* Zero size compare not an issue with DUK_MEMCMP. */
	rc = (duk_small_int_t) DUK_MEMCMP((const char *) DUK_HSTRING_GET_DATA(h1),
	                                  (const char *) DUK_HSTRING_GET_DATA(h2),
	                                  prefix_len);

	if (rc < 0) {
		ret = -1;
		goto done;
	} else if (rc > 0) {
		ret = 1;
		goto done;
	}

	/* prefix matches, lengths matter now */
	if (h1_len > h2_len) {
		ret = 1;
		goto done;
	} else if (h1_len == h2_len) {
		DUK_ASSERT(ret == 0);
		goto done;
	}
	ret = -1;
	goto done;

 done:
	duk_push_int(ctx, (duk_int_t) ret);
	return 1;
}

DUK_INTERNAL duk_small_int_t duk_js_string_compare(duk_hstring *h1, duk_hstring *h2) {
	/*
	 *  String comparison (E5 Section 11.8.5, step 4), which
	 *  needs to compare codepoint by codepoint.
	 *
	 *  However, UTF-8 allows us to use strcmp directly: the shared
	 *  prefix will be encoded identically (UTF-8 has unique encoding)
	 *  and the first differing character can be compared with a simple
	 *  unsigned byte comparison (which strcmp does).
	 *
	 *  This will not work properly for non-xutf-8 strings, but this
	 *  is not an issue for compliance.
	 */

	duk_size_t h1_len, h2_len, prefix_len;
	duk_small_int_t rc;

	DUK_ASSERT(h1 != NULL);
	DUK_ASSERT(h2 != NULL);
	h1_len = DUK_HSTRING_GET_BYTELEN(h1);
	h2_len = DUK_HSTRING_GET_BYTELEN(h2);
	prefix_len = (h1_len <= h2_len ? h1_len : h2_len);

	/* XXX: this special case can now be removed with DUK_MEMCMP */
	/* memcmp() should return zero (equal) for zero length, but avoid
	 * it because there are some platform specific bugs.  Don't use
	 * strncmp() because it stops comparing at a NUL.
	 */

	if (prefix_len == 0) {
		rc = 0;
	} else {
		rc = DUK_MEMCMP((const char *) DUK_HSTRING_GET_DATA(h1),
		                (const char *) DUK_HSTRING_GET_DATA(h2),
		                prefix_len);
	}

	if (rc < 0) {
		return -1;
	} else if (rc > 0) {
		return 1;
	}

	/* prefix matches, lengths matter now */
	if (h1_len < h2_len) {
		/* e.g. "x" < "xx" */
		return -1;
	} else if (h1_len > h2_len) {
		return 1;
	}

	return 0;
}

static duk_hstring *duk__find_matching_string(duk_heap *heap, duk_hstring **entries, duk_uint32_t size, duk_uint8_t *str, duk_uint32_t blen, duk_uint32_t strhash) {
	duk_uint32_t i;
	duk_uint32_t step;

	DUK_ASSERT(size > 0);

	i = DUK__HASH_INITIAL(strhash, size);
	step = DUK__HASH_PROBE_STEP(strhash);
	for (;;) {
		duk_hstring *e;

		e = entries[i];
		if (!e) {
			return NULL;
		}
		if (e != DUK__DELETED_MARKER(heap) && DUK_HSTRING_GET_BYTELEN(e) == blen) {
			if (DUK_MEMCMP(str, DUK_HSTRING_GET_DATA(e), blen) == 0) {
				DUK_DDD(DUK_DDDPRINT("find matching hit: %d (step %d, size %d)", i, step, size));
				return e;
			}
		}
		DUK_DDD(DUK_DDDPRINT("find matching miss: %d (step %d, size %d)", i, step, size));
		i = (i + step) % size;

		/* looping should never happen */
		DUK_ASSERT(i != DUK__HASH_INITIAL(strhash, size));
	}
	DUK_UNREACHABLE();
}

DUK_LOCAL void duk__print_hstring(duk__dprint_state *st, duk_hstring *h, duk_bool_t quotes) {
	duk_fixedbuffer *fb = st->fb;
	const duk_uint8_t *p;
	const duk_uint8_t *p_end;

	/* terminal type: no depth check */

	if (duk_fb_is_full(fb)) {
		return;
	}

	duk__print_shared_heaphdr_string(st, &h->hdr);

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

	p = DUK_HSTRING_GET_DATA(h);
	p_end = p + DUK_HSTRING_GET_BYTELEN(h);

	if (p_end > p && p[0] == DUK_ASC_UNDERSCORE) {
		/* if property key begins with underscore, encode it with
		 * forced quotes (e.g. "_Foo") to distinguish it from encoded
		 * internal properties (e.g. \xffBar -> _Bar).
		 */
		quotes = 1;
	}

	if (quotes) {
		duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_DOUBLEQUOTE);
	}
	while (p < p_end) {
		duk_uint8_t ch = *p++;

		/* two special escapes: '\' and '"', other printables as is */
		if (ch == '\\') {
			duk_fb_sprintf(fb, "\\\\");
		} else if (ch == '"') {
			duk_fb_sprintf(fb, "\\\"");
		} else if (ch >= 0x20 && ch <= 0x7e) {
			duk_fb_put_byte(fb, ch);
		} else if (ch == 0xff && !quotes) {
			/* encode \xffBar as _Bar if no quotes are applied, this is for
			 * readable internal keys.
			 */
			duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_UNDERSCORE);
		} else {
			duk_fb_sprintf(fb, "\\x%02lx", (unsigned long) ch);
		}
	}
	if (quotes) {
		duk_fb_put_byte(fb, (duk_uint8_t) DUK_ASC_DOUBLEQUOTE);
	}
#if defined(DUK_USE_REFERENCE_COUNTING)
	/* XXX: limit to quoted strings only, to save keys from being cluttered? */
	duk_fb_sprintf(fb, "/%lu", (unsigned long) DUK_HEAPHDR_GET_REFCOUNT(&h->hdr));
#endif
}

static duk_hstring *duk__alloc_init_hstring(duk_heap *heap,
                                            duk_uint8_t *str,
                                            duk_uint32_t blen,
                                            duk_uint32_t strhash) {
	duk_hstring *res = NULL;
	duk_uint8_t *data;
	duk_size_t alloc_size;
	duk_uarridx_t dummy;

	/* NUL terminate for convenient C access */

	alloc_size = (duk_size_t) (sizeof(duk_hstring) + blen + 1);
	res = (duk_hstring *) DUK_ALLOC(heap, alloc_size);
	if (!res) {
		goto error;
	}

	DUK_MEMZERO(res, sizeof(duk_hstring));
#ifdef DUK_USE_EXPLICIT_NULL_INIT
	DUK_HEAPHDR_STRING_INIT_NULLS(&res->hdr);
#endif
	DUK_HEAPHDR_SET_TYPE_AND_FLAGS(&res->hdr, DUK_HTYPE_STRING, 0);

	if (duk_js_to_arrayindex_raw_string(str, blen, &dummy)) {
		DUK_HSTRING_SET_ARRIDX(res);
	}

	/* All strings beginning with 0xff are treated as "internal",
	 * even strings interned by the user.  This allows user code to
	 * create internal properties too, and makes behavior consistent
	 * in case user code happens to use a string also used by Duktape
	 * (such as string has already been interned and has the 'internal'
	 * flag set).
	 */
	if (blen > 0 && str[0] == (duk_uint8_t) 0xff) {
		DUK_HSTRING_SET_INTERNAL(res);
	}

	res->hash = strhash;
	res->blen = blen;
	res->clen = (duk_uint32_t) duk_unicode_unvalidated_utf8_length(str, (duk_size_t) blen);  /* clen <= blen */

	data = (duk_uint8_t *) (res + 1);
	DUK_MEMCPY(data, str, blen);
	data[blen] = (duk_uint8_t) 0;

	DUK_DDD(DUK_DDDPRINT("interned string, hash=0x%08lx, blen=%ld, clen=%ld, has_arridx=%ld",
	                     (unsigned long) DUK_HSTRING_GET_HASH(res),
	                     (long) DUK_HSTRING_GET_BYTELEN(res),
	                     (long) DUK_HSTRING_GET_CHARLEN(res),
	                     (long) DUK_HSTRING_HAS_ARRIDX(res) ? 1 : 0));

	return res;

 error:
	DUK_FREE(heap, res);
	return NULL;
}

size_t duk_hbuffer_append_hstring(duk_hthread *thr, duk_hbuffer_dynamic *buf, duk_hstring *str) {
	size_t len;

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(buf != NULL);
	DUK_ASSERT(str != NULL);
	DUK_ASSERT(DUK_HBUFFER_HAS_DYNAMIC(buf));

	len = DUK_HSTRING_GET_BYTELEN(str);
	duk_hbuffer_insert_bytes(thr, buf, DUK_HBUFFER_GET_SIZE(buf), (duk_uint8_t *) DUK_HSTRING_GET_DATA(str), len);
	return len;
}

DUK_INTERNAL duk_bool_t duk_js_toboolean(duk_tval *tv) {
	switch (DUK_TVAL_GET_TAG(tv)) {
	case DUK_TAG_UNDEFINED:
	case DUK_TAG_NULL:
		return 0;
	case DUK_TAG_BOOLEAN:
		return DUK_TVAL_GET_BOOLEAN(tv);
	case DUK_TAG_STRING: {
		duk_hstring *h = DUK_TVAL_GET_STRING(tv);
		DUK_ASSERT(h != NULL);
		return (DUK_HSTRING_GET_BYTELEN(h) > 0 ? 1 : 0);
	}
	case DUK_TAG_OBJECT: {
		return 1;
	}
	case DUK_TAG_BUFFER: {
		/* mimic semantics for strings */
		duk_hbuffer *h = DUK_TVAL_GET_BUFFER(tv);
		DUK_ASSERT(h != NULL);
		return (DUK_HBUFFER_GET_SIZE(h) > 0 ? 1 : 0);
	}
	case DUK_TAG_POINTER: {
		void *p = DUK_TVAL_GET_POINTER(tv);
		return (p != NULL ? 1 : 0);
	}
	case DUK_TAG_LIGHTFUNC: {
		return 1;
	}
#if defined(DUK_USE_FASTINT)
	case DUK_TAG_FASTINT:
		if (DUK_TVAL_GET_FASTINT(tv) != 0) {
			return 1;
		} else {
			return 0;
		}
#endif
	default: {
		/* number */
		duk_double_t d;
		int c;
		DUK_ASSERT(!DUK_TVAL_IS_UNUSED(tv));
		DUK_ASSERT(DUK_TVAL_IS_DOUBLE(tv));
		d = DUK_TVAL_GET_DOUBLE(tv);
		c = DUK_FPCLASSIFY((double) d);
		if (c == DUK_FP_ZERO || c == DUK_FP_NAN) {
			return 0;
		} else {
			return 1;
		}
	}
	}
	DUK_UNREACHABLE();
}

DUK_LOCAL duk_hstring *duk__find_matching_string_chain(duk_heap *heap, const duk_uint8_t *str, duk_uint32_t blen, duk_uint32_t strhash) {
	duk_small_uint_t slotidx;
	duk_strtab_entry *e;
	duk_uint16_t *lst;
	duk_size_t i, n;
	duk_uint16_t null16 = heap->heapptr_null16;

	DUK_ASSERT(heap != NULL);

	slotidx = strhash % DUK_STRTAB_CHAIN_SIZE;
	DUK_ASSERT(slotidx < DUK_STRTAB_CHAIN_SIZE);

	e = heap->strtable + slotidx;
	if (e->listlen == 0) {
		if (e->u.str16 != null16) {
			duk_hstring *h = (duk_hstring *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, e->u.str16);
			DUK_ASSERT(h != NULL);
			if (DUK_HSTRING_GET_BYTELEN(h) == blen &&
			    DUK_MEMCMP((const void *) str, (const void *) DUK_HSTRING_GET_DATA(h), (size_t) blen) == 0) {
				return h;
			}
		}
	} else {
		DUK_ASSERT(e->u.strlist16 != null16);
		lst = (duk_uint16_t *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, e->u.strlist16);
		DUK_ASSERT(lst != NULL);
		for (i = 0, n = e->listlen; i < n; i++) {
			if (lst[i] != null16) {
				duk_hstring *h = (duk_hstring *) DUK_USE_HEAPPTR_DEC16(heap->heap_udata, lst[i]);
				DUK_ASSERT(h != NULL);
				if (DUK_HSTRING_GET_BYTELEN(h) == blen &&
				    DUK_MEMCMP((const void *) str, (const void *) DUK_HSTRING_GET_DATA(h), (size_t) blen) == 0) {
					return h;
				}
			}
		}
	}

	return NULL;
}

DUK_INTERNAL duk_small_int_t duk_js_string_compare(duk_hstring *h1, duk_hstring *h2) {
	/*
	 *  String comparison (E5 Section 11.8.5, step 4), which
	 *  needs to compare codepoint by codepoint.
	 *
	 *  However, UTF-8 allows us to use strcmp directly: the shared
	 *  prefix will be encoded identically (UTF-8 has unique encoding)
	 *  and the first differing character can be compared with a simple
	 *  unsigned byte comparison (which strcmp does).
	 *
	 *  This will not work properly for non-xutf-8 strings, but this
	 *  is not an issue for compliance.
	 */

	DUK_ASSERT(h1 != NULL);
	DUK_ASSERT(h2 != NULL);

	return duk_js_data_compare((const duk_uint8_t *) DUK_HSTRING_GET_DATA(h1),
	                           (const duk_uint8_t *) DUK_HSTRING_GET_DATA(h2),
	                           (duk_size_t) DUK_HSTRING_GET_BYTELEN(h1),
	                           (duk_size_t) DUK_HSTRING_GET_BYTELEN(h2));
}

DUK_INTERNAL void duk_regexp_create_instance(duk_hthread *thr) {
    duk_context *ctx = (duk_context *) thr;
    duk_hobject *h;
    duk_hstring *h_bc;
    duk_small_int_t re_flags;

    /* [ ... escape_source bytecode ] */

    h_bc = duk_get_hstring(ctx, -1);
    DUK_ASSERT(h_bc != NULL);
    DUK_ASSERT(DUK_HSTRING_GET_BYTELEN(h_bc) >= 1);          /* always at least the header */
    DUK_ASSERT(DUK_HSTRING_GET_CHARLEN(h_bc) >= 1);
    DUK_ASSERT((duk_small_int_t) DUK_HSTRING_GET_DATA(h_bc)[0] < 0x80);  /* flags always encodes to 1 byte */
    re_flags = (duk_small_int_t) DUK_HSTRING_GET_DATA(h_bc)[0];

    /* [ ... escaped_source bytecode ] */

    duk_push_object(ctx);
    h = duk_get_hobject(ctx, -1);
    DUK_ASSERT(h != NULL);
    duk_insert(ctx, -3);

    /* [ ... regexp_object escaped_source bytecode ] */

    DUK_HOBJECT_SET_CLASS_NUMBER(h, DUK_HOBJECT_CLASS_REGEXP);
    DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, h, thr->builtins[DUK_BIDX_REGEXP_PROTOTYPE]);

    duk_xdef_prop_stridx(ctx, -3, DUK_STRIDX_INT_BYTECODE, DUK_PROPDESC_FLAGS_NONE);

    /* [ ... regexp_object escaped_source ] */

    duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_SOURCE, DUK_PROPDESC_FLAGS_NONE);

    /* [ ... regexp_object ] */

    duk_push_boolean(ctx, (re_flags & DUK_RE_FLAG_GLOBAL));
    duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_GLOBAL, DUK_PROPDESC_FLAGS_NONE);

    duk_push_boolean(ctx, (re_flags & DUK_RE_FLAG_IGNORE_CASE));
    duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_IGNORE_CASE, DUK_PROPDESC_FLAGS_NONE);

    duk_push_boolean(ctx, (re_flags & DUK_RE_FLAG_MULTILINE));
    duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_MULTILINE, DUK_PROPDESC_FLAGS_NONE);

    duk_push_int(ctx, 0);
    duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_LAST_INDEX, DUK_PROPDESC_FLAGS_W);

    /* [ ... regexp_object ] */
}

/* Called by duk_hstring.h macros */
DUK_INTERNAL duk_uarridx_t duk_js_to_arrayindex_string_helper(duk_hstring *h) {
	duk_uarridx_t res;
	duk_small_int_t rc;

	if (!DUK_HSTRING_HAS_ARRIDX(h)) {
		return DUK_HSTRING_NO_ARRAY_INDEX;
	}

	rc = duk_js_to_arrayindex_raw_string(DUK_HSTRING_GET_DATA(h),
	                                     DUK_HSTRING_GET_BYTELEN(h),
	                                     &res);
	DUK_UNREF(rc);
	DUK_ASSERT(rc != 0);
	return res;
}

DUK_LOCAL duk_uint8_t *duk__dump_hstring_raw(duk_uint8_t *p, duk_hstring *h) {
	duk_size_t len;
	duk_uint32_t tmp32;

	DUK_ASSERT(h != NULL);

	len = DUK_HSTRING_GET_BYTELEN(h);
	DUK_ASSERT(len <= 0xffffffffUL);  /* string limits */
	tmp32 = (duk_uint32_t) len;
	DUK_RAW_WRITE_U32_BE(p, tmp32);
	DUK_MEMCPY((void *) p,
	           (const void *) DUK_HSTRING_GET_DATA(h),
	           len);
	p += len;
	return p;
}

static duk_hstring *duk__alloc_init_hstring(duk_heap *heap,
                                            duk_uint8_t *str,
                                            duk_uint32_t blen,
                                            duk_uint32_t strhash) {
	duk_hstring *res = NULL;
	duk_uint8_t *data;
	duk_uint32_t alloc_size;
	duk_uint32_t dummy;

	/* NUL terminate for convenient C access */

	alloc_size = sizeof(duk_hstring) + blen + 1;
	res = (duk_hstring *) DUK_ALLOC(heap, alloc_size);
	if (!res) {
		goto error;
	}

	DUK_MEMZERO(res, sizeof(duk_hstring));
#ifdef DUK_USE_EXPLICIT_NULL_INIT
	DUK_HEAPHDR_STRING_INIT_NULLS(&res->hdr);
#endif
	DUK_HEAPHDR_SET_TYPE_AND_FLAGS(&res->hdr, DUK_HTYPE_STRING, 0);

	if (duk_js_to_arrayindex_raw_string(str, blen, &dummy)) {
		DUK_HSTRING_SET_ARRIDX(res);
	}

	res->hash = strhash;
	res->blen = blen;
	res->clen = (duk_uint32_t) duk_unicode_unvalidated_utf8_length(str, (duk_size_t) blen);  /* clen <= blen */

	data = (duk_uint8_t *) (res + 1);
	DUK_MEMCPY(data, str, blen);
	data[blen] = (duk_uint8_t) 0;

	DUK_DDD(DUK_DDDPRINT("interned string, hash=0x%08x, blen=%d, clen=%d, arridx=%d",
	                     DUK_HSTRING_GET_HASH(res),
	                     DUK_HSTRING_GET_BYTELEN(res),
	                     DUK_HSTRING_GET_CHARLEN(res),
	                     DUK_HSTRING_HAS_ARRIDX(res) ? 1 : 0));

	return res;

 error:
	DUK_FREE(heap, res);
	return NULL;
}