view src/vim9class.c @ 33225:52b121d4feb5 v9.0.1887

patch 9.0.1887: Vim9: class members are accessible via object Commit: https://github.com/vim/vim/commit/23c92d93c1b877edf18881b715ad51ec26386c2e Author: Yegappan Lakshmanan <yegappan@yahoo.com> Date: Sat Sep 9 11:33:29 2023 +0200 patch 9.0.1887: Vim9: class members are accessible via object Problem: Vim9: class members are accessible via object Solution: Disable class member variable access using an object Class methods can be accessed only using the class name and cannot be accessed using an object. To be consistent with this, do the same for class member variables also. They can be accessed only using the class name and not using an object. closes: #13057 Signed-off-by: Christian Brabandt <cb@256bit.org> Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
author Christian Brabandt <cb@256bit.org>
date Sat, 09 Sep 2023 11:45:06 +0200
parents 499ba27ba0f6
children 3672d3d13524
line wrap: on
line source

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * vim9class.c: Vim9 script class support
 */

#define USING_FLOAT_STUFF
#include "vim.h"

#if defined(FEAT_EVAL) || defined(PROTO)

// When not generating protos this is included in proto.h
#ifdef PROTO
# include "vim9.h"
#endif

static class_T *first_class = NULL;
static class_T *next_nonref_class = NULL;

/*
 * Call this function when a class has been created.  It will be added to the
 * list headed by "first_class".
 */
    static void
class_created(class_T *cl)
{
    if (first_class != NULL)
    {
	cl->class_next_used = first_class;
	first_class->class_prev_used = cl;
    }
    first_class = cl;
}

/*
 * Call this function when a class has been cleared and is about to be freed.
 * It is removed from the list headed by "first_class".
 */
    static void
class_cleared(class_T *cl)
{
    if (cl->class_next_used != NULL)
	cl->class_next_used->class_prev_used = cl->class_prev_used;
    if (cl->class_prev_used != NULL)
	cl->class_prev_used->class_next_used = cl->class_next_used;
    else if (first_class == cl)
	first_class = cl->class_next_used;

    // update the next class to check if needed
    if (cl == next_nonref_class)
	next_nonref_class = cl->class_next_used;
}

/*
 * Parse a member declaration, both object and class member.
 * Returns OK or FAIL.  When OK then "varname_end" is set to just after the
 * variable name and "type_ret" is set to the declared or detected type.
 * "init_expr" is set to the initialisation expression (allocated), if there is
 * one.  For an interface "init_expr" is NULL.
 */
    static int
parse_member(
    exarg_T	*eap,
    char_u	*line,
    char_u	*varname,
    int		has_public,	    // TRUE if "public" seen before "varname"
    char_u	**varname_end,
    garray_T	*type_list,
    type_T	**type_ret,
    char_u	**init_expr)
{
    *varname_end = to_name_end(varname, FALSE);
    if (*varname == '_' && has_public)
    {
	semsg(_(e_public_member_name_cannot_start_with_underscore_str), line);
	return FAIL;
    }

    char_u *colon = skipwhite(*varname_end);
    char_u *type_arg = colon;
    type_T *type = NULL;
    if (*colon == ':')
    {
	if (VIM_ISWHITE(**varname_end))
	{
	    semsg(_(e_no_white_space_allowed_before_colon_str), varname);
	    return FAIL;
	}
	if (!VIM_ISWHITE(colon[1]))
	{
	    semsg(_(e_white_space_required_after_str_str), ":", varname);
	    return FAIL;
	}
	type_arg = skipwhite(colon + 1);
	type = parse_type(&type_arg, type_list, TRUE);
	if (type == NULL)
	    return FAIL;
    }

    char_u *init_arg = skipwhite(type_arg);
    if (type == NULL && *init_arg != '=')
    {
	emsg(_(e_type_or_initialization_required));
	return FAIL;
    }

    if (init_expr == NULL && *init_arg == '=')
    {
	emsg(_(e_cannot_initialize_member_in_interface));
	return FAIL;
    }

    if (*init_arg == '=')
    {
	evalarg_T evalarg;
	char_u *expr_start, *expr_end;

	if (!VIM_ISWHITE(init_arg[-1]) || !VIM_ISWHITE(init_arg[1]))
	{
	    semsg(_(e_white_space_required_before_and_after_str_at_str),
							"=", type_arg);
	    return FAIL;
	}
	init_arg = skipwhite(init_arg + 1);

	fill_evalarg_from_eap(&evalarg, eap, FALSE);
	(void)skip_expr_concatenate(&init_arg, &expr_start, &expr_end, &evalarg);

	// No type specified for the member.  Set it to "any" and the correct
	// type will be set when the object is instantiated.
	if (type == NULL)
	    type = &t_any;

	*init_expr = vim_strnsave(expr_start, expr_end - expr_start);
	// Free the memory pointed by expr_start.
	clear_evalarg(&evalarg, NULL);
    }
    else if (!valid_declaration_type(type))
	return FAIL;

    *type_ret = type;
    return OK;
}

/*
 * Add a member to an object or a class.
 * Returns OK when successful, "init_expr" will be consumed then.
 * Returns FAIL otherwise, caller might need to free "init_expr".
 */
    static int
add_member(
    garray_T	*gap,
    char_u	*varname,
    char_u	*varname_end,
    int		has_public,
    type_T	*type,
    char_u	*init_expr)
{
    if (ga_grow(gap, 1) == FAIL)
	return FAIL;
    ocmember_T *m = ((ocmember_T *)gap->ga_data) + gap->ga_len;
    m->ocm_name = vim_strnsave(varname, varname_end - varname);
    m->ocm_access = has_public ? VIM_ACCESS_ALL
		      : *varname == '_' ? VIM_ACCESS_PRIVATE : VIM_ACCESS_READ;
    m->ocm_type = type;
    if (init_expr != NULL)
	m->ocm_init = init_expr;
    ++gap->ga_len;
    return OK;
}

/*
 * Move the class or object members found while parsing a class into the class.
 * "gap" contains the found members.
 * "parent_members" points to the members in the parent class (if any)
 * "parent_count" is the number of members in the parent class
 * "members" will be set to the newly allocated array of members and
 * "member_count" set to the number of members.
 * Returns OK or FAIL.
 */
    static int
add_members_to_class(
    garray_T	*gap,
    ocmember_T	*parent_members,
    int		parent_count,
    ocmember_T	**members,
    int		*member_count)
{
    *member_count = parent_count + gap->ga_len;
    *members = *member_count == 0 ? NULL
				       : ALLOC_MULT(ocmember_T, *member_count);
    if (*member_count > 0 && *members == NULL)
	return FAIL;
    for (int i = 0; i < parent_count; ++i)
    {
	// parent members need to be copied
	ocmember_T	*m = *members + i;
	*m = parent_members[i];
	m->ocm_name = vim_strsave(m->ocm_name);
	if (m->ocm_init != NULL)
	    m->ocm_init = vim_strsave(m->ocm_init);
    }
    if (gap->ga_len > 0)
	// new members are moved
	mch_memmove(*members + parent_count,
			       gap->ga_data, sizeof(ocmember_T) * gap->ga_len);
    VIM_CLEAR(gap->ga_data);
    return OK;
}

/*
 * Convert a member index "idx" of interface "itf" to the member index of class
 * "cl" implementing that interface.
 */
    int
object_index_from_itf_index(class_T *itf, int is_method, int idx, class_T *cl,
								int is_static)
{
    if (idx >= (is_method ? itf->class_obj_method_count
				   : is_static ? itf->class_class_member_count
						: itf->class_obj_member_count))
    {
	siemsg("index %d out of range for interface %s", idx, itf->class_name);
	return 0;
    }

    // If "cl" is the interface or the class that is extended, then the method
    // index can be used directly and there is no need to search for the method
    // index in one of the child classes.
    if (cl == itf)
	return idx;

    itf2class_T		*i2c = NULL;
    int			searching = TRUE;
    int			method_offset = 0;

    for (class_T *super = cl; super != NULL && searching;
						super = super->class_extends)
    {
	for (i2c = itf->class_itf2class; i2c != NULL; i2c = i2c->i2c_next)
	{
	    if (i2c->i2c_class == super && i2c->i2c_is_method == is_method)
	    {
		searching = FALSE;
		break;
	    }
	}
	if (searching && is_method)
	    // The parent class methods are stored after the current class
	    // methods.
	    method_offset += is_static
				? super->class_class_function_count_child
				: super->class_obj_method_count_child;
    }
    if (i2c == NULL)
    {
	siemsg("class %s not found on interface %s",
					      cl->class_name, itf->class_name);
	return 0;
    }
    if (is_static)
    {
	// TODO: Need a table for fast lookup?
	char_u *name = itf->class_class_members[idx].ocm_name;
	for (int i = 0; i < i2c->i2c_class->class_class_member_count; ++i)
	{
	    ocmember_T *m = &i2c->i2c_class->class_class_members[i];
	    if (STRCMP(name, m->ocm_name) == 0)
	    {
		return i;
	    }
	}
	siemsg("class %s, interface %s, static %s not found",
				      cl->class_name, itf->class_name, name);
	return 0;
    }
    else
    {
	// A table follows the i2c for the class
	int *table = (int *)(i2c + 1);
	// "method_offset" is 0, if method is in the current class.  If method
	// is in a parent class, then it is non-zero.
	return table[idx] + method_offset;
    }
}

/*
 * Check whether a class named "extends_name" is present.  If the class is
 * valid, then "extends_clp" is set with the class pointer.
 * Returns TRUE if the class name "extends_names" is a valid class.
 */
    static int
validate_extends_class(char_u *extends_name, class_T **extends_clp)
{
    typval_T	tv;
    int		success = FALSE;

    tv.v_type = VAR_UNKNOWN;
    if (eval_variable_import(extends_name, &tv) == FAIL)
    {
	semsg(_(e_class_name_not_found_str), extends_name);
	return success;
    }

    if (tv.v_type != VAR_CLASS
	    || tv.vval.v_class == NULL
	    || (tv.vval.v_class->class_flags & CLASS_INTERFACE) != 0)
	semsg(_(e_cannot_extend_str), extends_name);
    else
    {
	class_T *extends_cl = tv.vval.v_class;
	++extends_cl->class_refcount;
	*extends_clp = extends_cl;
	success = TRUE;
    }
    clear_tv(&tv);

    return success;
}

/*
 * Check whether a class/object member variable in "classmembers_gap" /
 * "objmembers_gap" is a duplicate of a member in any of the extended parent
 * class lineage.  Returns TRUE if there are no duplicates.
 */
    static int
validate_extends_members(
    garray_T	*classmembers_gap,
    garray_T	*objmembers_gap,
    class_T	*extends_cl)
{
    for (int loop = 1; loop <= 2; ++loop)
    {
	// loop == 1: check class members
	// loop == 2: check object members
	int member_count = loop == 1 ? classmembers_gap->ga_len
						: objmembers_gap->ga_len;
	if (member_count == 0)
	    continue;
	ocmember_T *members = (ocmember_T *)(loop == 1
						? classmembers_gap->ga_data
						: objmembers_gap->ga_data);

	// Validate each member variable
	for (int c_i = 0; c_i < member_count; c_i++)
	{
	    class_T	*p_cl = extends_cl;
	    ocmember_T	*c_m = members + c_i;
	    char_u	*pstr = (*c_m->ocm_name == '_')
					? c_m->ocm_name + 1 : c_m->ocm_name;

	    // Check in all the parent classes in the lineage
	    while (p_cl != NULL)
	    {
		int p_member_count = loop == 1
					? p_cl->class_class_member_count
					: p_cl->class_obj_member_count;
		if (p_member_count == 0)
		    continue;
		ocmember_T *p_members = (loop == 1
					? p_cl->class_class_members
					: p_cl->class_obj_members);

		// Compare against all the members in the parent class
		for (int p_i = 0; p_i < p_member_count; p_i++)
		{
		    ocmember_T	*p_m = p_members + p_i;
		    char_u	*qstr = (*p_m->ocm_name == '_')
					? p_m->ocm_name + 1 : p_m->ocm_name;
		    if (STRCMP(pstr, qstr) == 0)
		    {
			semsg(_(e_duplicate_member_str), c_m->ocm_name);
			return FALSE;
		    }
		}

		p_cl = p_cl->class_extends;
	    }
	}
    }

    return TRUE;
}

/*
 * When extending an abstract class, check whether all the abstract methods in
 * the parent class are implemented.  Returns TRUE if all the methods are
 * implemented.
 */
    static int
validate_extends_methods(
    garray_T	*classmethods_gap,
    garray_T	*objmethods_gap,
    class_T	*extends_cl)
{
    for (int loop = 1; loop <= 2; ++loop)
    {
	// loop == 1: check class methods
	// loop == 2: check object methods
	int extends_method_count = loop == 1
				? extends_cl->class_class_function_count
				: extends_cl->class_obj_method_count;
	if (extends_method_count == 0)
	    continue;

	ufunc_T **extends_methods = loop == 1
				? extends_cl->class_class_functions
				: extends_cl->class_obj_methods;

	int method_count = loop == 1 ? classmethods_gap->ga_len
						: objmethods_gap->ga_len;
	ufunc_T **cl_fp = (ufunc_T **)(loop == 1
						? classmethods_gap->ga_data
						: objmethods_gap->ga_data);

	for (int i = 0; i < extends_method_count; i++)
	{
	    ufunc_T *uf = extends_methods[i];
	    if ((uf->uf_flags & FC_ABSTRACT) == 0)
		continue;

	    int method_found = FALSE;

	    for (int j = 0; j < method_count; j++)
	    {
		if (STRCMP(uf->uf_name, cl_fp[j]->uf_name) == 0)
		{
		    method_found = TRUE;
		    break;
		}
	    }

	    if (!method_found)
	    {
		semsg(_(e_abstract_method_str_not_found), uf->uf_name);
		return FALSE;
	    }
	}
    }

    return TRUE;
}

/*
 * Check the members of the interface class "ifcl" match the class members
 * ("classmembers_gap") and object members ("objmembers_gap") of a class.
 * Returns TRUE if the class and object member names are valid.
 */
    static int
validate_interface_members(
    char_u	*intf_class_name,
    class_T	*ifcl,
    garray_T	*classmembers_gap,
    garray_T	*objmembers_gap)
{
    for (int loop = 1; loop <= 2; ++loop)
    {
	// loop == 1: check class members
	// loop == 2: check object members
	int if_count = loop == 1 ? ifcl->class_class_member_count
						: ifcl->class_obj_member_count;
	if (if_count == 0)
	    continue;
	ocmember_T *if_ms = loop == 1 ? ifcl->class_class_members
						: ifcl->class_obj_members;
	ocmember_T *cl_ms = (ocmember_T *)(loop == 1
						? classmembers_gap->ga_data
						: objmembers_gap->ga_data);
	int cl_count = loop == 1 ? classmembers_gap->ga_len
						: objmembers_gap->ga_len;
	for (int if_i = 0; if_i < if_count; ++if_i)
	{
	    int cl_i;
	    for (cl_i = 0; cl_i < cl_count; ++cl_i)
	    {
		ocmember_T	*m = &cl_ms[cl_i];
		where_T		where = WHERE_INIT;

		if (STRCMP(if_ms[if_i].ocm_name, m->ocm_name) != 0)
		    continue;

		// Ensure the type is matching.
		where.wt_func_name = (char *)m->ocm_name;
		where.wt_kind = WT_MEMBER;
		if (check_type(if_ms[if_i].ocm_type, m->ocm_type, TRUE,
								where) == FAIL)
		    return FALSE;

		if (if_ms[if_i].ocm_access != m->ocm_access)
		{
		    semsg(_(e_member_str_of_interface_str_has_different_access),
			    if_ms[if_i].ocm_name, intf_class_name);
		    return FALSE;
		}

		break;
	    }
	    if (cl_i == cl_count)
	    {
		semsg(_(e_member_str_of_interface_str_not_implemented),
			if_ms[if_i].ocm_name, intf_class_name);
		return FALSE;
	    }
	}
    }

    return TRUE;
}

/*
 * Check the functions/methods of the interface class "ifcl" match the class
 * methods ("classfunctions_gap") and object functions ("objmemthods_gap") of a
 * class.
 * Returns TRUE if the class and object member names are valid.
 */
    static int
validate_interface_methods(
    char_u	*intf_class_name,
    class_T	*ifcl,
    garray_T	*classfunctions_gap,
    garray_T	*objmethods_gap)
{
    for (int loop = 1; loop <= 2; ++loop)
    {
	// loop == 1: check class functions
	// loop == 2: check object methods
	int if_count = loop == 1 ? ifcl->class_class_function_count
					: ifcl->class_obj_method_count;
	if (if_count == 0)
	    continue;
	ufunc_T **if_fp = loop == 1 ? ifcl->class_class_functions
						: ifcl->class_obj_methods;
	ufunc_T **cl_fp = (ufunc_T **)(loop == 1
						? classfunctions_gap->ga_data
						: objmethods_gap->ga_data);
	int cl_count = loop == 1 ? classfunctions_gap->ga_len
						: objmethods_gap->ga_len;
	for (int if_i = 0; if_i < if_count; ++if_i)
	{
	    char_u	*if_name = if_fp[if_i]->uf_name;
	    int		cl_i;
	    for (cl_i = 0; cl_i < cl_count; ++cl_i)
	    {
		char_u *cl_name = cl_fp[cl_i]->uf_name;
		if (STRCMP(if_name, cl_name) == 0)
		{
		    where_T where = WHERE_INIT;

		    // Ensure the type is matching.
		    where.wt_func_name = (char *)if_name;
		    where.wt_kind = WT_METHOD;
		    if (check_type(if_fp[if_i]->uf_func_type,
			cl_fp[cl_i]->uf_func_type, TRUE, where) == FAIL)
			return FALSE;
		    break;
		}
	    }
	    if (cl_i == cl_count)
	    {
		semsg(_(e_function_str_of_interface_str_not_implemented),
			if_name, intf_class_name);
		return FALSE;
	    }
	}
    }

    return TRUE;
}

/*
 * Validate all the "implements" classes when creating a new class.  The
 * classes are returned in "intf_classes".  The class functions, class members,
 * object methods and object members in the new class are in
 * "classfunctions_gap", "classmembers_gap", "objmethods_gap", and
 * "objmembers_gap" respectively.
 */
    static int
validate_implements_classes(
    garray_T	*impl_gap,
    class_T	**intf_classes,
    garray_T	*classfunctions_gap,
    garray_T	*classmembers_gap,
    garray_T	*objmethods_gap,
    garray_T	*objmembers_gap)
{
    int		success = TRUE;

    for (int i = 0; i < impl_gap->ga_len && success; ++i)
    {
	char_u *impl = ((char_u **)impl_gap->ga_data)[i];
	typval_T tv;
	tv.v_type = VAR_UNKNOWN;
	if (eval_variable_import(impl, &tv) == FAIL)
	{
	    semsg(_(e_interface_name_not_found_str), impl);
	    success = FALSE;
	    break;
	}

	if (tv.v_type != VAR_CLASS
		|| tv.vval.v_class == NULL
		|| (tv.vval.v_class->class_flags & CLASS_INTERFACE) == 0)
	{
	    semsg(_(e_not_valid_interface_str), impl);
	    success = FALSE;
	    clear_tv(&tv);
	    break;
	}

	class_T *ifcl = tv.vval.v_class;
	intf_classes[i] = ifcl;
	++ifcl->class_refcount;

	// check the members of the interface match the members of the class
	success = validate_interface_members(impl, ifcl, classmembers_gap,
							objmembers_gap);

	// check the functions/methods of the interface match the
	// functions/methods of the class
	if (success)
	    success = validate_interface_methods(impl, ifcl,
					classfunctions_gap, objmethods_gap);
	clear_tv(&tv);
    }

    return success;
}

/*
 * Check no function argument name is used as a class member.
 * (Object members are always accessed with "this." prefix, so no need
 * to check them.)
 */
    static int
check_func_arg_names(
    garray_T	*classfunctions_gap,
    garray_T	*objmethods_gap,
    garray_T	*classmembers_gap)
{
    // loop 1: class functions, loop 2: object methods
    for (int loop = 1; loop <= 2; ++loop)
    {
	garray_T *gap = loop == 1 ? classfunctions_gap : objmethods_gap;

	for (int fi = 0; fi < gap->ga_len; ++fi)
	{
	    ufunc_T *uf = ((ufunc_T **)gap->ga_data)[fi];

	    for (int i = 0; i < uf->uf_args.ga_len; ++i)
	    {
		char_u *aname = ((char_u **)uf->uf_args.ga_data)[i];
		garray_T *mgap = classmembers_gap;

		// Check all the class member names
		for (int mi = 0; mi < mgap->ga_len; ++mi)
		{
		    char_u *mname =
				((ocmember_T *)mgap->ga_data + mi)->ocm_name;
		    if (STRCMP(aname, mname) == 0)
		    {
			if (uf->uf_script_ctx.sc_sid > 0)
			    SOURCING_LNUM = uf->uf_script_ctx.sc_lnum;

			semsg(_(e_argument_already_declared_in_class_str),
				aname);

			return FALSE;
		    }
		}
	    }
	}
    }

    return TRUE;
}

/*
 * Returns TRUE if the member "varname" is already defined.
 */
    static int
is_duplicate_member(garray_T *mgap, char_u *varname, char_u *varname_end)
{
    char_u	*name = vim_strnsave(varname, varname_end - varname);
    char_u	*pstr = (*name == '_') ? name + 1 : name;
    int		dup = FALSE;

    for (int i = 0; i < mgap->ga_len; ++i)
    {
	ocmember_T *m = ((ocmember_T *)mgap->ga_data) + i;
	char_u	*qstr = *m->ocm_name == '_' ? m->ocm_name + 1 : m->ocm_name;
	if (STRCMP(pstr, qstr) == 0)
	{
	    semsg(_(e_duplicate_member_str), name);
	    dup = TRUE;
	    break;
	}
    }

    vim_free(name);
    return dup;
}

/*
 * Returns TRUE if the method "name" is already defined.
 */
    static int
is_duplicate_method(garray_T *fgap, char_u *name)
{
    char_u *pstr = (*name == '_') ? name + 1 : name;

    for (int i = 0; i < fgap->ga_len; ++i)
    {
	char_u	*n = ((ufunc_T **)fgap->ga_data)[i]->uf_name;
	char_u	*qstr = *n == '_' ? n + 1 : n;
	if (STRCMP(pstr, qstr) == 0)
	{
	    semsg(_(e_duplicate_function_str), name);
	    return TRUE;
	}
    }

    return FALSE;
}

/*
 * Returns TRUE if the constructor is valid.
 */
    static int
is_valid_constructor(ufunc_T *uf, int is_abstract, int has_static)
{
    // Constructors are not allowed in abstract classes.
    if (is_abstract)
    {
	emsg(_(e_cannot_define_new_function_in_abstract_class));
	return FALSE;
    }
    // A constructor is always static, no need to define it so.
    if (has_static)
    {
	emsg(_(e_cannot_define_new_function_as_static));
	return FALSE;
    }
    // A return type should not be specified for the new()
    // constructor method.
    if (uf->uf_ret_type->tt_type != VAR_VOID)
    {
	emsg(_(e_cannot_use_a_return_type_with_new));
	return FALSE;
    }
    return TRUE;
}

/*
 * Update the interface class lookup table for the member index on the
 * interface to the member index in the class implementing the interface.
 * And a lookup table for the object method index on the interface
 * to the object method index in the class implementing the interface.
 * This is also used for updating the lookup table for the extended class
 * hierarchy.
 */
    static int
update_member_method_lookup_table(
    class_T	*ifcl,
    class_T	*cl,
    garray_T	*objmethods,
    int		pobj_method_offset,
    int		is_interface)
{
    if (ifcl == NULL)
	return OK;

    // Table for members.
    itf2class_T *if2cl = alloc_clear(sizeof(itf2class_T)
				+ ifcl->class_obj_member_count * sizeof(int));
    if (if2cl == NULL)
	return FAIL;
    if2cl->i2c_next = ifcl->class_itf2class;
    ifcl->class_itf2class = if2cl;
    if2cl->i2c_class = cl;
    if2cl->i2c_is_method = FALSE;

    for (int if_i = 0; if_i < ifcl->class_obj_member_count; ++if_i)
	for (int cl_i = 0; cl_i < cl->class_obj_member_count; ++cl_i)
	{
	    if (STRCMP(ifcl->class_obj_members[if_i].ocm_name,
				cl->class_obj_members[cl_i].ocm_name) == 0)
	    {
		int *table = (int *)(if2cl + 1);
		table[if_i] = cl_i;
		break;
	    }
	}

    // Table for methods.
    if2cl = alloc_clear(sizeof(itf2class_T)
				+ ifcl->class_obj_method_count * sizeof(int));
    if (if2cl == NULL)
	return FAIL;
    if2cl->i2c_next = ifcl->class_itf2class;
    ifcl->class_itf2class = if2cl;
    if2cl->i2c_class = cl;
    if2cl->i2c_is_method = TRUE;

    for (int if_i = 0; if_i < ifcl->class_obj_method_count; ++if_i)
    {
	int done = FALSE;
	for (int cl_i = 0; cl_i < objmethods->ga_len; ++cl_i)
	{
	    if (STRCMP(ifcl->class_obj_methods[if_i]->uf_name,
			((ufunc_T **)objmethods->ga_data)[cl_i]->uf_name) == 0)
	    {
		int *table = (int *)(if2cl + 1);
		table[if_i] = cl_i;
		done = TRUE;
		break;
	    }
	}

	// extended class object method is not overridden by the child class.
	// Keep the method declared in one of the parent classes in the
	// lineage.
	if (!done && !is_interface)
	{
	    // If "ifcl" is not the immediate parent of "cl", then search in
	    // the intermediate parent classes.
	    if (cl->class_extends != ifcl)
	    {
		class_T		*parent = cl->class_extends;
		int		method_offset = objmethods->ga_len;

		while (!done && parent != NULL && parent != ifcl)
		{

		    for (int cl_i = 0;
			    cl_i < parent->class_obj_method_count_child; ++cl_i)
		    {
			if (STRCMP(ifcl->class_obj_methods[if_i]->uf_name,
				    parent->class_obj_methods[cl_i]->uf_name)
				== 0)
			{
			    int *table = (int *)(if2cl + 1);
			    table[if_i] = method_offset + cl_i;
			    done = TRUE;
			    break;
			}
		    }
		    method_offset += parent->class_obj_method_count_child;
		    parent = parent->class_extends;
		}
	    }

	    if (!done)
	    {
		int *table = (int *)(if2cl + 1);
		table[if_i] = pobj_method_offset + if_i;
	    }
	}
    }

    return OK;
}

/*
 * Update the member and object method lookup tables for a new class in the
 * interface class.
 * For each interface add a lookup table for the member index on the interface
 * to the member index in the new class.  And a lookup table for the object
 * method index on the interface to the object method index in the new class.
 */
    static int
add_lookup_tables(class_T *cl, class_T *extends_cl, garray_T *objmethods_gap)
{
    for (int i = 0; i < cl->class_interface_count; ++i)
    {
	class_T *ifcl = cl->class_interfaces_cl[i];

	if (update_member_method_lookup_table(ifcl, cl, objmethods_gap,
							0, TRUE) == FAIL)
	    return FAIL;
    }

    // Update the lookup table for the extended class, if nay
    if (extends_cl != NULL)
    {
	class_T		*pclass = extends_cl;
	int		pobj_method_offset = objmethods_gap->ga_len;

	// Update the entire lineage of extended classes.
	while (pclass != NULL)
	{
	    if (update_member_method_lookup_table(pclass, cl,
			objmethods_gap, pobj_method_offset, FALSE) == FAIL)
		return FAIL;

	    pobj_method_offset += pclass->class_obj_method_count_child;
	    pclass = pclass->class_extends;
	}
    }

    return OK;
}

/*
 * Add class members to a new class.  Allocate a typval for each class member
 * and initialize it.
 */
    static void
add_class_members(class_T *cl, exarg_T *eap)
{
    // Allocate a typval for each class member and initialize it.
    cl->class_members_tv = ALLOC_CLEAR_MULT(typval_T,
					    cl->class_class_member_count);
    if (cl->class_members_tv == NULL)
	return;

    for (int i = 0; i < cl->class_class_member_count; ++i)
    {
	ocmember_T	*m = &cl->class_class_members[i];
	typval_T	*tv = &cl->class_members_tv[i];
	if (m->ocm_init != NULL)
	{
	    typval_T *etv = eval_expr(m->ocm_init, eap);
	    if (etv != NULL)
	    {
		*tv = *etv;
		vim_free(etv);
	    }
	}
	else
	{
	    // TODO: proper default value
	    tv->v_type = m->ocm_type->tt_type;
	    tv->vval.v_string = NULL;
	}
    }
}

/*
 * Add a default constructor method (new()) to the class "cl".
 */
    static void
add_default_constructor(
    class_T	*cl,
    garray_T	*classfunctions_gap,
    garray_T	*type_list_gap)
{
    garray_T fga;

    ga_init2(&fga, 1, 1000);
    ga_concat(&fga, (char_u *)"new(");
    for (int i = 0; i < cl->class_obj_member_count; ++i)
    {
	if (i > 0)
	    ga_concat(&fga, (char_u *)", ");
	ga_concat(&fga, (char_u *)"this.");
	ocmember_T *m = cl->class_obj_members + i;
	ga_concat(&fga, (char_u *)m->ocm_name);
	ga_concat(&fga, (char_u *)" = v:none");
    }
    ga_concat(&fga, (char_u *)")\nenddef\n");
    ga_append(&fga, NUL);

    exarg_T fea;
    CLEAR_FIELD(fea);
    fea.cmdidx = CMD_def;
    fea.cmd = fea.arg = fga.ga_data;

    garray_T lines_to_free;
    ga_init2(&lines_to_free, sizeof(char_u *), 50);

    ufunc_T *nf = define_function(&fea, NULL, &lines_to_free, CF_CLASS);

    ga_clear_strings(&lines_to_free);
    vim_free(fga.ga_data);

    if (nf != NULL && ga_grow(classfunctions_gap, 1) == OK)
    {
	((ufunc_T **)classfunctions_gap->ga_data)[classfunctions_gap->ga_len]
									= nf;
	++classfunctions_gap->ga_len;

	nf->uf_flags |= FC_NEW;
	nf->uf_ret_type = get_type_ptr(type_list_gap);
	if (nf->uf_ret_type != NULL)
	{
	    nf->uf_ret_type->tt_type = VAR_OBJECT;
	    nf->uf_ret_type->tt_class = cl;
	    nf->uf_ret_type->tt_argcount = 0;
	    nf->uf_ret_type->tt_args = NULL;
	}
    }
}

/*
 * Add the class functions and object methods to the new class "cl".
 * When extending a class, add the functions and methods from the parent class
 * also.
 */
    static int
add_classfuncs_objmethods(
    class_T	*cl,
    class_T	*extends_cl,
    garray_T	*classfunctions_gap,
    garray_T	*objmethods_gap)
{
    // loop 1: class functions, loop 2: object methods
    for (int loop = 1; loop <= 2; ++loop)
    {
	garray_T	*gap = loop == 1 ? classfunctions_gap : objmethods_gap;
	int		*fcount = loop == 1 ? &cl->class_class_function_count
						: &cl->class_obj_method_count;
	ufunc_T		***fup = loop == 1 ? &cl->class_class_functions
						: &cl->class_obj_methods;

	int parent_count = 0;
	if (extends_cl != NULL)
	    // Include functions from the parent.
	    parent_count = loop == 1
				? extends_cl->class_class_function_count
				: extends_cl->class_obj_method_count;

	*fcount = parent_count + gap->ga_len;
	if (*fcount == 0)
	{
	    *fup = NULL;
	    continue;
	}
	*fup = ALLOC_MULT(ufunc_T *, *fcount);
	if (*fup == NULL)
	    return FAIL;

	if (gap->ga_len != 0)
	    mch_memmove(*fup, gap->ga_data, sizeof(ufunc_T *) * gap->ga_len);
	vim_free(gap->ga_data);
	if (loop == 1)
	    cl->class_class_function_count_child = gap->ga_len;
	else
	    cl->class_obj_method_count_child = gap->ga_len;

	int skipped = 0;
	for (int i = 0; i < parent_count; ++i)
	{
	    // Copy functions from the parent.  Can't use the same
	    // function, because "uf_class" is different and compilation
	    // will have a different result.
	    // Put them after the functions in the current class, object
	    // methods may be overruled, then "super.Method()" is used to
	    // find a method from the parent.
	    // Skip "new" functions. TODO: not all of them.
	    if (loop == 1 && STRNCMP(
				extends_cl->class_class_functions[i]->uf_name,
				"new", 3) == 0)
		++skipped;
	    else
	    {
		ufunc_T *pf = (loop == 1
					? extends_cl->class_class_functions
					: extends_cl->class_obj_methods)[i];
		(*fup)[gap->ga_len + i - skipped] = copy_function(pf);

		// If the child class overrides a function from the parent
		// the signature must be equal.
		char_u *pname = pf->uf_name;
		for (int ci = 0; ci < gap->ga_len; ++ci)
		{
		    ufunc_T *cf = (*fup)[ci];
		    char_u *cname = cf->uf_name;
		    if (STRCMP(pname, cname) == 0)
		    {
			where_T where = WHERE_INIT;
			where.wt_func_name = (char *)pname;
			where.wt_kind = WT_METHOD;
			(void)check_type(pf->uf_func_type, cf->uf_func_type,
								TRUE, where);
		    }
		}
	    }
	}

	*fcount -= skipped;

	// Set the class pointer on all the functions and object methods.
	for (int i = 0; i < *fcount; ++i)
	{
	    ufunc_T *fp = (*fup)[i];
	    fp->uf_class = cl;
	    if (loop == 2)
		fp->uf_flags |= FC_OBJECT;
	}
    }

    return OK;
}

/*
 * Handle ":class" and ":abstract class" up to ":endclass".
 * Handle ":interface" up to ":endinterface".
 */
    void
ex_class(exarg_T *eap)
{
    int		is_class = eap->cmdidx == CMD_class;  // FALSE for :interface
    long	start_lnum = SOURCING_LNUM;
    char_u	*arg = eap->arg;
    int		is_abstract = eap->cmdidx == CMD_abstract;

    if (is_abstract)
    {
	if (STRNCMP(arg, "class", 5) != 0 || !VIM_ISWHITE(arg[5]))
	{
	    semsg(_(e_invalid_argument_str), arg);
	    return;
	}
	arg = skipwhite(arg + 5);
	is_class = TRUE;
    }

    if (!current_script_is_vim9()
		|| (cmdmod.cmod_flags & CMOD_LEGACY)
		|| !getline_equal(eap->getline, eap->cookie, getsourceline))
    {
	if (is_class)
	    emsg(_(e_class_can_only_be_defined_in_vim9_script));
	else
	    emsg(_(e_interface_can_only_be_defined_in_vim9_script));
	return;
    }

    if (!ASCII_ISUPPER(*arg))
    {
	if (is_class)
	    semsg(_(e_class_name_must_start_with_uppercase_letter_str), arg);
	else
	    semsg(_(e_interface_name_must_start_with_uppercase_letter_str),
									  arg);
	return;
    }
    char_u *name_end = find_name_end(arg, NULL, NULL, FNE_CHECK_START);
    if (!IS_WHITE_OR_NUL(*name_end))
    {
	semsg(_(e_white_space_required_after_name_str), arg);
	return;
    }
    char_u *name_start = arg;

    // "export class" gets used when creating the class, don't use "is_export"
    // for the items inside the class.
    int class_export = is_export;
    is_export = FALSE;

    // TODO:
    //    generics: <Tkey, Tentry>

    // Name for "extends BaseClass"
    char_u *extends = NULL;

    // Names for "implements SomeInterface"
    garray_T	ga_impl;
    ga_init2(&ga_impl, sizeof(char_u *), 5);

    arg = skipwhite(name_end);
    while (*arg != NUL && *arg != '#' && *arg != '\n')
    {
	// TODO:
	//    specifies SomeInterface
	if (STRNCMP(arg, "extends", 7) == 0 && IS_WHITE_OR_NUL(arg[7]))
	{
	    if (extends != NULL)
	    {
		emsg(_(e_duplicate_extends));
		goto early_ret;
	    }
	    arg = skipwhite(arg + 7);
	    char_u *end = find_name_end(arg, NULL, NULL, FNE_CHECK_START);
	    if (!IS_WHITE_OR_NUL(*end))
	    {
		semsg(_(e_white_space_required_after_name_str), arg);
		goto early_ret;
	    }
	    extends = vim_strnsave(arg, end - arg);
	    if (extends == NULL)
		goto early_ret;

	    arg = skipwhite(end + 1);
	}
	else if (STRNCMP(arg, "implements", 10) == 0
						   && IS_WHITE_OR_NUL(arg[10]))
	{
	    if (ga_impl.ga_len > 0)
	    {
		emsg(_(e_duplicate_implements));
		goto early_ret;
	    }
	    arg = skipwhite(arg + 10);

	    for (;;)
	    {
		char_u *impl_end = find_name_end(arg, NULL, NULL,
							      FNE_CHECK_START);
		if (!IS_WHITE_OR_NUL(*impl_end) && *impl_end != ',')
		{
		    semsg(_(e_white_space_required_after_name_str), arg);
		    goto early_ret;
		}
		char_u *iname = vim_strnsave(arg, impl_end - arg);
		if (iname == NULL)
		    goto early_ret;
		for (int i = 0; i < ga_impl.ga_len; ++i)
		    if (STRCMP(((char_u **)ga_impl.ga_data)[i], iname) == 0)
		    {
			semsg(_(e_duplicate_interface_after_implements_str),
									iname);
			vim_free(iname);
			goto early_ret;
		    }
		if (ga_add_string(&ga_impl, iname) == FAIL)
		{
		    vim_free(iname);
		    goto early_ret;
		}
		if (*impl_end != ',')
		{
		    arg = skipwhite(impl_end);
		    break;
		}
		arg = skipwhite(impl_end + 1);
	    }
	}
	else
	{
	    semsg(_(e_trailing_characters_str), arg);
early_ret:
	    vim_free(extends);
	    ga_clear_strings(&ga_impl);
	    return;
	}
    }

    garray_T	type_list;	    // list of pointers to allocated types
    ga_init2(&type_list, sizeof(type_T *), 10);

    // Growarray with class members declared in the class.
    garray_T classmembers;
    ga_init2(&classmembers, sizeof(ocmember_T), 10);

    // Growarray with functions declared in the class.
    garray_T classfunctions;
    ga_init2(&classfunctions, sizeof(ufunc_T *), 10);

    // Growarray with object members declared in the class.
    garray_T objmembers;
    ga_init2(&objmembers, sizeof(ocmember_T), 10);

    // Growarray with object methods declared in the class.
    garray_T objmethods;
    ga_init2(&objmethods, sizeof(ufunc_T *), 10);

    /*
     * Go over the body of the class/interface until "endclass" or
     * "endinterface" is found.
     */
    char_u *theline = NULL;
    int success = FALSE;
    for (;;)
    {
	vim_free(theline);
	theline = eap->getline(':', eap->cookie, 0, GETLINE_CONCAT_ALL);
	if (theline == NULL)
	    break;
	char_u *line = skipwhite(theline);

	// Skip empty and comment lines.
	if (*line == NUL)
	    continue;
	if (*line == '#')
	{
	    if (vim9_bad_comment(line))
		break;
	    continue;
	}

	char_u *p = line;
	char *end_name = is_class ? "endclass" : "endinterface";
	if (checkforcmd(&p, end_name, is_class ? 4 : 5))
	{
	    if (STRNCMP(line, end_name, is_class ? 8 : 12) != 0)
		semsg(_(e_command_cannot_be_shortened_str), line);
	    else if (*p == '|' || !ends_excmd2(line, p))
		semsg(_(e_trailing_characters_str), p);
	    else
		success = TRUE;
	    break;
	}
	char *wrong_name = is_class ? "endinterface" : "endclass";
	if (checkforcmd(&p, wrong_name, is_class ? 5 : 4))
	{
	    semsg(_(e_invalid_command_str_expected_str), line, end_name);
	    break;
	}

	int has_public = FALSE;
	if (checkforcmd(&p, "public", 3))
	{
	    if (STRNCMP(line, "public", 6) != 0)
	    {
		semsg(_(e_command_cannot_be_shortened_str), line);
		break;
	    }
	    has_public = TRUE;
	    p = skipwhite(line + 6);

	    if (STRNCMP(p, "this", 4) != 0 && STRNCMP(p, "static", 6) != 0)
	    {
		emsg(_(e_public_must_be_followed_by_this_or_static));
		break;
	    }
	}

	int abstract_method = FALSE;
	char_u *pa = p;
	if (checkforcmd(&p, "abstract", 3))
	{
	    if (STRNCMP(pa, "abstract", 8) != 0)
	    {
		semsg(_(e_command_cannot_be_shortened_str), pa);
		break;
	    }

	    if (!is_abstract)
	    {
		semsg(_(e_abstract_method_in_concrete_class), pa);
		break;
	    }

	    abstract_method = TRUE;
	    p = skipwhite(pa + 8);
	    if (STRNCMP(p, "def", 3) != 0 && STRNCMP(p, "static", 6) != 0)
	    {
		emsg(_(e_abstract_must_be_followed_by_def_or_static));
		break;
	    }
	}

	int has_static = FALSE;
	char_u *ps = p;
	if (checkforcmd(&p, "static", 4))
	{
	    if (STRNCMP(ps, "static", 6) != 0)
	    {
		semsg(_(e_command_cannot_be_shortened_str), ps);
		break;
	    }
	    has_static = TRUE;
	    p = skipwhite(ps + 6);
	}

	// object members (public, read access, private):
	//	"this._varname"
	//	"this.varname"
	//	"public this.varname"
	if (STRNCMP(p, "this", 4) == 0)
	{
	    if (p[4] != '.' || !eval_isnamec1(p[5]))
	    {
		semsg(_(e_invalid_object_member_declaration_str), p);
		break;
	    }
	    if (has_static)
	    {
		emsg(_(e_static_cannot_be_followed_by_this));
		break;
	    }
	    char_u *varname = p + 5;
	    char_u *varname_end = NULL;
	    type_T *type = NULL;
	    char_u *init_expr = NULL;
	    if (parse_member(eap, line, varname, has_public,
			  &varname_end, &type_list, &type,
			  is_class ? &init_expr: NULL) == FAIL)
		break;
	    if (is_duplicate_member(&objmembers, varname, varname_end))
	    {
		vim_free(init_expr);
		break;
	    }
	    if (add_member(&objmembers, varname, varname_end,
					  has_public, type, init_expr) == FAIL)
	    {
		vim_free(init_expr);
		break;
	    }
	}

	// constructors:
	//	  def new()
	//	  enddef
	//	  def newOther()
	//	  enddef
	// object methods and class functions:
	//	  def SomeMethod()
	//	  enddef
	//	  static def ClassFunction()
	//	  enddef
	// TODO:
	//	  def <Tval> someMethod()
	//	  enddef
	else if (checkforcmd(&p, "def", 3))
	{
	    exarg_T	ea;
	    garray_T	lines_to_free;

	    // TODO: error for "public static def Func()"?

	    CLEAR_FIELD(ea);
	    ea.cmd = line;
	    ea.arg = p;
	    ea.cmdidx = CMD_def;
	    ea.getline = eap->getline;
	    ea.cookie = eap->cookie;

	    ga_init2(&lines_to_free, sizeof(char_u *), 50);
	    int class_flags;
	    if (is_class)
		class_flags = abstract_method ? CF_ABSTRACT_METHOD : CF_CLASS;
	    else
		class_flags = CF_INTERFACE;
	    ufunc_T *uf = define_function(&ea, NULL, &lines_to_free,
								class_flags);
	    ga_clear_strings(&lines_to_free);

	    if (uf != NULL)
	    {
		char_u	*name = uf->uf_name;
		int	is_new = STRNCMP(name, "new", 3) == 0;

		if (is_new && !is_valid_constructor(uf, is_abstract,
								has_static))
		{
		    func_clear_free(uf, FALSE);
		    break;
		}

		garray_T *fgap = has_static || is_new
					       ? &classfunctions : &objmethods;
		// Check the name isn't used already.
		if (is_duplicate_method(fgap, name))
		{
		    success = FALSE;
		    func_clear_free(uf, FALSE);
		    break;
		}

		if (ga_grow(fgap, 1) == OK)
		{
		    if (is_new)
			uf->uf_flags |= FC_NEW;

		    if (abstract_method)
			uf->uf_flags |= FC_ABSTRACT;

		    ((ufunc_T **)fgap->ga_data)[fgap->ga_len] = uf;
		    ++fgap->ga_len;
		}
	    }
	}

	// class members
	else if (has_static)
	{
	    // class members (public, read access, private):
	    //	"static _varname"
	    //	"static varname"
	    //	"public static varname"
	    char_u *varname = p;
	    char_u *varname_end = NULL;
	    type_T *type = NULL;
	    char_u *init_expr = NULL;
	    if (parse_member(eap, line, varname, has_public,
		      &varname_end, &type_list, &type,
		      is_class ? &init_expr : NULL) == FAIL)
		break;
	    if (is_duplicate_member(&classmembers, varname, varname_end))
	    {
		vim_free(init_expr);
		break;
	    }
	    if (add_member(&classmembers, varname, varname_end,
				      has_public, type, init_expr) == FAIL)
	    {
		vim_free(init_expr);
		break;
	    }
	}

	else
	{
	    if (is_class)
		semsg(_(e_not_valid_command_in_class_str), line);
	    else
		semsg(_(e_not_valid_command_in_interface_str), line);
	    break;
	}
    }
    vim_free(theline);

    class_T *extends_cl = NULL;  // class from "extends" argument

    /*
     * Check a few things before defining the class.
     */

    // Check the "extends" class is valid.
    if (success && extends != NULL)
	success = validate_extends_class(extends, &extends_cl);
    VIM_CLEAR(extends);

    // Check the new class members and object members are not duplicates of the
    // members in the extended class lineage.
    if (success && extends_cl != NULL)
	success = validate_extends_members(&classmembers, &objmembers,
								extends_cl);

    // When extending an abstract class, make sure all the abstract methods in
    // the parent class are implemented.  If the current class is an abstract
    // class, then there is no need for this check.
    if (success && !is_abstract && extends_cl != NULL
				&& (extends_cl->class_flags & CLASS_ABSTRACT))
	success = validate_extends_methods(&classfunctions, &objmethods,
								extends_cl);

    class_T **intf_classes = NULL;

    // Check all "implements" entries are valid.
    if (success && ga_impl.ga_len > 0)
    {
	intf_classes = ALLOC_CLEAR_MULT(class_T *, ga_impl.ga_len);

	success = validate_implements_classes(&ga_impl, intf_classes,
					&classfunctions, &classmembers,
					&objmethods, &objmembers);
    }

    // Check no function argument name is used as a class member.
    if (success)
	success = check_func_arg_names(&classfunctions, &objmethods,
							&classmembers);

    class_T *cl = NULL;
    if (success)
    {
	// "endclass" encountered without failures: Create the class.

	cl = ALLOC_CLEAR_ONE(class_T);
	if (cl == NULL)
	    goto cleanup;
	if (!is_class)
	    cl->class_flags = CLASS_INTERFACE;
	else if (is_abstract)
	    cl->class_flags = CLASS_ABSTRACT;

	cl->class_refcount = 1;
	cl->class_name = vim_strnsave(name_start, name_end - name_start);
	if (cl->class_name == NULL)
	    goto cleanup;

	if (extends_cl != NULL)
	{
	    cl->class_extends = extends_cl;
	    extends_cl->class_flags |= CLASS_EXTENDED;
	}

	// Add class and object members to "cl".
	if (add_members_to_class(&classmembers,
				 extends_cl == NULL ? NULL
					     : extends_cl->class_class_members,
				 extends_cl == NULL ? 0
					: extends_cl->class_class_member_count,
				 &cl->class_class_members,
				 &cl->class_class_member_count) == FAIL
		|| add_members_to_class(&objmembers,
				 extends_cl == NULL ? NULL
					       : extends_cl->class_obj_members,
				 extends_cl == NULL ? 0
					  : extends_cl->class_obj_member_count,
				 &cl->class_obj_members,
				 &cl->class_obj_member_count) == FAIL)
	    goto cleanup;

	if (ga_impl.ga_len > 0)
	{
	    // Move the "implements" names into the class.
	    cl->class_interface_count = ga_impl.ga_len;
	    cl->class_interfaces = ALLOC_MULT(char_u *, ga_impl.ga_len);
	    if (cl->class_interfaces == NULL)
		goto cleanup;
	    for (int i = 0; i < ga_impl.ga_len; ++i)
		cl->class_interfaces[i] = ((char_u **)ga_impl.ga_data)[i];
	    VIM_CLEAR(ga_impl.ga_data);
	    ga_impl.ga_len = 0;

	    cl->class_interfaces_cl = intf_classes;
	    intf_classes = NULL;
	}

	if (cl->class_interface_count > 0 || extends_cl != NULL)
	{
	    // Add a method and member lookup table to each of the interface
	    // classes.
	    if (add_lookup_tables(cl, extends_cl, &objmethods) == FAIL)
		goto cleanup;
	}

	// Allocate a typval for each class member and initialize it.
	if (is_class && cl->class_class_member_count > 0)
	    add_class_members(cl, eap);

	int	have_new = FALSE;
	ufunc_T	*class_func = NULL;
	for (int i = 0; i < classfunctions.ga_len; ++i)
	{
	    class_func = ((ufunc_T **)classfunctions.ga_data)[i];
	    if (STRCMP(class_func->uf_name, "new") == 0)
	    {
		have_new = TRUE;
		break;
	    }
	}

	if (have_new)
	    // The return type of new() is an object of class "cl"
	    class_func->uf_ret_type->tt_class = cl;
	else if (is_class && !is_abstract && !have_new)
	    // No new() method was defined, add the default constructor.
	    add_default_constructor(cl, &classfunctions, &type_list);

	// Move all the functions into the created class.
	if (add_classfuncs_objmethods(cl, extends_cl, &classfunctions,
							&objmethods) == FAIL)
	    goto cleanup;

	cl->class_type.tt_type = VAR_CLASS;
	cl->class_type.tt_class = cl;
	cl->class_object_type.tt_type = VAR_OBJECT;
	cl->class_object_type.tt_class = cl;
	cl->class_type_list = type_list;

	class_created(cl);

	// TODO:
	// - Fill hashtab with object members and methods ?

	// Add the class to the script-local variables.
	// TODO: handle other context, e.g. in a function
	// TODO: does uf_hash need to be cleared?
	typval_T tv;
	tv.v_type = VAR_CLASS;
	tv.vval.v_class = cl;
	is_export = class_export;
	SOURCING_LNUM = start_lnum;
	set_var_const(cl->class_name, current_sctx.sc_sid,
						       NULL, &tv, FALSE, 0, 0);
	return;
    }

cleanup:
    if (cl != NULL)
    {
	vim_free(cl->class_name);
	vim_free(cl->class_class_functions);
	if (cl->class_interfaces != NULL)
	{
	    for (int i = 0; i < cl->class_interface_count; ++i)
		vim_free(cl->class_interfaces[i]);
	    vim_free(cl->class_interfaces);
	}
	if (cl->class_interfaces_cl != NULL)
	{
	    for (int i = 0; i < cl->class_interface_count; ++i)
		class_unref(cl->class_interfaces_cl[i]);
	    vim_free(cl->class_interfaces_cl);
	}
	vim_free(cl->class_obj_members);
	vim_free(cl->class_obj_methods);
	vim_free(cl);
    }

    vim_free(extends);
    class_unref(extends_cl);

    if (intf_classes != NULL)
    {
	for (int i = 0; i < ga_impl.ga_len; ++i)
	    class_unref(intf_classes[i]);
	vim_free(intf_classes);
    }
    ga_clear_strings(&ga_impl);

    for (int round = 1; round <= 2; ++round)
    {
	garray_T *gap = round == 1 ? &classmembers : &objmembers;
	if (gap->ga_len == 0 || gap->ga_data == NULL)
	    continue;

	for (int i = 0; i < gap->ga_len; ++i)
	{
	    ocmember_T *m = ((ocmember_T *)gap->ga_data) + i;
	    vim_free(m->ocm_name);
	    vim_free(m->ocm_init);
	}
	ga_clear(gap);
    }

    for (int i = 0; i < objmethods.ga_len; ++i)
    {
	ufunc_T *uf = ((ufunc_T **)objmethods.ga_data)[i];
	func_clear_free(uf, FALSE);
    }
    ga_clear(&objmethods);

    for (int i = 0; i < classfunctions.ga_len; ++i)
    {
	ufunc_T *uf = ((ufunc_T **)classfunctions.ga_data)[i];
	func_clear_free(uf, FALSE);
    }
    ga_clear(&classfunctions);

    clear_type_list(&type_list);
}

/*
 * Find member "name" in class "cl", set "member_idx" to the member index and
 * return its type.
 * When "is_object" is TRUE, then look for object members.  Otherwise look for
 * class members.
 * When not found "member_idx" is set to -1 and t_any is returned.
 * Set *p_m ocmmember_T if not NULL
 */
    type_T *
class_member_type(
    class_T	*cl,
    int		is_object,
    char_u	*name,
    char_u	*name_end,
    int		*member_idx,
    ocmember_T	**p_m)
{
    *member_idx = -1;  // not found (yet)
    size_t	len = name_end - name;
    int		member_count = is_object ? cl->class_obj_member_count
						: cl->class_class_member_count;
    ocmember_T	*members = is_object ? cl->class_obj_members
						: cl->class_class_members;

    for (int i = 0; i < member_count; ++i)
    {
	ocmember_T *m = members + i;
	if (STRNCMP(m->ocm_name, name, len) == 0 && m->ocm_name[len] == NUL)
	{
	    *member_idx = i;
	    if (p_m != NULL)
		*p_m = m;
	    return m->ocm_type;
	}
    }

    semsg(_(e_unknown_variable_str), name);
    return &t_any;
}

/*
 * Handle ":enum" up to ":endenum".
 */
    void
ex_enum(exarg_T *eap UNUSED)
{
    // TODO
}

/*
 * Handle ":type".
 */
    void
ex_type(exarg_T *eap UNUSED)
{
    // TODO
}

/*
 * Returns OK if a member variable named "name" is present in the class "cl".
 * Otherwise returns FAIL.  If found, the member variable typval is set in
 * "rettv".  If "is_object" is TRUE, then the object member variable table is
 * searched.  Otherwise the class member variable table is searched.
 */
    static int
get_member_tv(
    class_T	*cl,
    int		is_object,
    char_u	*name,
    size_t	namelen,
    typval_T	*rettv)
{
    int member_count = is_object ? cl->class_obj_member_count
						: cl->class_class_member_count;
    ocmember_T *members = is_object ? cl->class_obj_members
						: cl->class_class_members;

    for (int i = 0; i < member_count; ++i)
    {
	ocmember_T *m = &members[i];
	if (STRNCMP(name, m->ocm_name, namelen) == 0
						&& m->ocm_name[namelen] == NUL)
	{
	    if (*name == '_')
	    {
		semsg(_(e_cannot_access_private_member_str), m->ocm_name);
		return FAIL;
	    }

	    // The object only contains a pointer to the class, the member
	    // values array follows right after that.
	    object_T *obj = rettv->vval.v_object;
	    if (is_object)
	    {
		typval_T *tv = (typval_T *)(obj + 1) + i;
		copy_tv(tv, rettv);
	    }
	    else
		copy_tv(&cl->class_members_tv[i], rettv);

	    object_unref(obj);

	    return OK;
	}
    }

    return FAIL;
}

/*
 * Evaluate what comes after a class:
 * - class member: SomeClass.varname
 * - class function: SomeClass.SomeMethod()
 * - class constructor: SomeClass.new()
 * - object member: someObject.varname
 * - object method: someObject.SomeMethod()
 *
 * "*arg" points to the '.'.
 * "*arg" is advanced to after the member name or method call.
 *
 * Returns FAIL or OK.
 */
    int
class_object_index(
    char_u	**arg,
    typval_T	*rettv,
    evalarg_T	*evalarg,
    int		verbose UNUSED)	// give error messages
{
    if (VIM_ISWHITE((*arg)[1]))
    {
	semsg(_(e_no_white_space_allowed_after_str_str), ".", *arg);
	return FAIL;
    }

    ++*arg;
    char_u *name = *arg;
    char_u *name_end = find_name_end(name, NULL, NULL, FNE_CHECK_START);
    if (name_end == name)
	return FAIL;
    size_t len = name_end - name;

    class_T *cl;
    if (rettv->v_type == VAR_CLASS)
	cl = rettv->vval.v_class;
    else // VAR_OBJECT
    {
	if (rettv->vval.v_object == NULL)
	{
	    emsg(_(e_using_null_object));
	    return FAIL;
	}
	cl = rettv->vval.v_object->obj_class;
    }

    if (cl == NULL)
    {
	emsg(_(e_incomplete_type));
	return FAIL;
    }

    if (*name_end == '(')
    {
	int on_class = rettv->v_type == VAR_CLASS;
	int count = on_class ? cl->class_class_function_count
			     : cl->class_obj_method_count;
	for (int i = 0; i < count; ++i)
	{
	    ufunc_T *fp = on_class ? cl->class_class_functions[i]
				   : cl->class_obj_methods[i];
	    // Use a separate pointer to avoid that ASAN complains about
	    // uf_name[] only being 4 characters.
	    char_u *ufname = (char_u *)fp->uf_name;
	    if (STRNCMP(name, ufname, len) == 0 && ufname[len] == NUL)
	    {
		typval_T	argvars[MAX_FUNC_ARGS + 1];
		int		argcount = 0;

		if (*ufname == '_')
		{
		    // Cannot access a private method outside of a class
		    semsg(_(e_cannot_access_private_method_str), name);
		    return FAIL;
		}

		char_u *argp = name_end;
		int ret = get_func_arguments(&argp, evalarg, 0,
							   argvars, &argcount);
		if (ret == FAIL)
		    return FAIL;

		funcexe_T funcexe;
		CLEAR_FIELD(funcexe);
		funcexe.fe_evaluate = TRUE;
		if (rettv->v_type == VAR_OBJECT)
		{
		    funcexe.fe_object = rettv->vval.v_object;
		    ++funcexe.fe_object->obj_refcount;
		}

		// Clear the class or object after calling the function, in
		// case the refcount is one.
		typval_T tv_tofree = *rettv;
		rettv->v_type = VAR_UNKNOWN;

		// Call the user function.  Result goes into rettv;
		int error = call_user_func_check(fp, argcount, argvars,
							rettv, &funcexe, NULL);

		// Clear the previous rettv and the arguments.
		clear_tv(&tv_tofree);
		for (int idx = 0; idx < argcount; ++idx)
		    clear_tv(&argvars[idx]);

		if (error != FCERR_NONE)
		{
		    user_func_error(error, printable_func_name(fp),
							 funcexe.fe_found_var);
		    return FAIL;
		}
		*arg = argp;
		return OK;
	    }
	}

	semsg(_(e_method_not_found_on_class_str_str), cl->class_name, name);
    }

    else if (rettv->v_type == VAR_OBJECT)
    {
	// Search in the object member variable table and the class member
	// variable table.
	if (get_member_tv(cl, TRUE, name, len, rettv) == OK)
	{
	    *arg = name_end;
	    return OK;
	}

	semsg(_(e_member_not_found_on_object_str_str), cl->class_name, name);
    }

    else if (rettv->v_type == VAR_CLASS)
    {
	// class member
	for (int i = 0; i < cl->class_class_member_count; ++i)
	{
	    ocmember_T *m = &cl->class_class_members[i];
	    if (STRNCMP(name, m->ocm_name, len) == 0 && m->ocm_name[len] == NUL)
	    {
		if (*name == '_')
		{
		    semsg(_(e_cannot_access_private_member_str), m->ocm_name);
		    return FAIL;
		}
		if ((cl->class_flags & CLASS_INTERFACE) != 0)
		{
		    semsg(_(e_interface_static_direct_access_str),
						cl->class_name, m->ocm_name);
		    return FAIL;
		}

		typval_T *tv = &cl->class_members_tv[i];
		copy_tv(tv, rettv);
		class_unref(cl);

		*arg = name_end;
		return OK;
	    }
	}

	semsg(_(e_member_not_found_on_class_str_str), cl->class_name, name);
    }

    return FAIL;
}

/*
 * If "arg" points to a class or object method, return it.
 * Otherwise return NULL.
 */
    ufunc_T *
find_class_func(char_u **arg)
{
    char_u *name = *arg;
    char_u *name_end = find_name_end(name, NULL, NULL, FNE_CHECK_START);
    if (name_end == name || *name_end != '.')
	return NULL;

    size_t	len = name_end - name;
    typval_T	tv;
    tv.v_type = VAR_UNKNOWN;
    if (eval_variable(name, (int)len,
				    0, &tv, NULL, EVAL_VAR_NOAUTOLOAD) == FAIL)
	return NULL;
    if (tv.v_type != VAR_CLASS && tv.v_type != VAR_OBJECT)
	goto fail_after_eval;

    class_T *cl = tv.v_type == VAR_CLASS ? tv.vval.v_class
						 : tv.vval.v_object->obj_class;
    if (cl == NULL)
	goto fail_after_eval;
    char_u *fname = name_end + 1;
    char_u *fname_end = find_name_end(fname, NULL, NULL, FNE_CHECK_START);
    if (fname_end == fname)
	goto fail_after_eval;
    len = fname_end - fname;

    int count = tv.v_type == VAR_CLASS ? cl->class_class_function_count
				       : cl->class_obj_method_count;
    ufunc_T **funcs = tv.v_type == VAR_CLASS ? cl->class_class_functions
					     : cl->class_obj_methods;
    for (int i = 0; i < count; ++i)
    {
	ufunc_T *fp = funcs[i];
	// Use a separate pointer to avoid that ASAN complains about
	// uf_name[] only being 4 characters.
	char_u *ufname = (char_u *)fp->uf_name;
	if (STRNCMP(fname, ufname, len) == 0 && ufname[len] == NUL)
	{
	    clear_tv(&tv);
	    return fp;
	}
    }

fail_after_eval:
    clear_tv(&tv);
    return NULL;
}

/*
 * If "name[len]" is a class member in cctx->ctx_ufunc->uf_class return the
 * index in class.class_class_members[].
 * If "cl_ret" is not NULL set it to the class.
 * Otherwise return -1;
 */
    int
class_member_index(char_u *name, size_t len, class_T **cl_ret, cctx_T *cctx)
{
    if (cctx == NULL || cctx->ctx_ufunc == NULL
					  || cctx->ctx_ufunc->uf_class == NULL)
	return -1;
    class_T *cl = cctx->ctx_ufunc->uf_class;

    for (int i = 0; i < cl->class_class_member_count; ++i)
    {
	ocmember_T *m = &cl->class_class_members[i];
	if (STRNCMP(name, m->ocm_name, len) == 0 && m->ocm_name[len] == NUL)
	{
	    if (cl_ret != NULL)
		*cl_ret = cl;
	    return i;
	}
    }
    return -1;
}

/*
 * Return TRUE if current context "cctx_arg" is inside class "cl".
 * Return FALSE if not.
 */
    int
inside_class(cctx_T *cctx_arg, class_T *cl)
{
    for (cctx_T *cctx = cctx_arg; cctx != NULL; cctx = cctx->ctx_outer)
	if (cctx->ctx_ufunc != NULL
			&& class_instance_of(cctx->ctx_ufunc->uf_class, cl))
	    return TRUE;
    return FALSE;
}

/*
 * Make a copy of an object.
 */
    void
copy_object(typval_T *from, typval_T *to)
{
    if (from->vval.v_object == NULL)
	to->vval.v_object = NULL;
    else
    {
	to->vval.v_object = from->vval.v_object;
	++to->vval.v_object->obj_refcount;
    }
}

/*
 * Free an object.
 */
    static void
object_clear(object_T *obj)
{
    // Avoid a recursive call, it can happen if "obj" has a circular reference.
    obj->obj_refcount = INT_MAX;

    class_T *cl = obj->obj_class;

    if (!cl)
	return;

    // the member values are just after the object structure
    typval_T *tv = (typval_T *)(obj + 1);
    for (int i = 0; i < cl->class_obj_member_count; ++i)
	clear_tv(tv + i);

    // Remove from the list headed by "first_object".
    object_cleared(obj);

    vim_free(obj);
    class_unref(cl);
}

/*
 * Unreference an object.
 */
    void
object_unref(object_T *obj)
{
    if (obj != NULL && --obj->obj_refcount <= 0)
	object_clear(obj);
}

/*
 * Make a copy of a class.
 */
    void
copy_class(typval_T *from, typval_T *to)
{
    if (from->vval.v_class == NULL)
	to->vval.v_class = NULL;
    else
    {
	to->vval.v_class = from->vval.v_class;
	++to->vval.v_class->class_refcount;
    }
}

/*
 * Free the class "cl" and its contents.
 */
    static void
class_free(class_T *cl)
{
    // Freeing what the class contains may recursively come back here.
    // Clear "class_name" first, if it is NULL the class does not need to
    // be freed.
    VIM_CLEAR(cl->class_name);

    class_unref(cl->class_extends);

    for (int i = 0; i < cl->class_interface_count; ++i)
    {
	vim_free(((char_u **)cl->class_interfaces)[i]);
	if (cl->class_interfaces_cl[i] != NULL)
	    class_unref(cl->class_interfaces_cl[i]);
    }
    vim_free(cl->class_interfaces);
    vim_free(cl->class_interfaces_cl);

    itf2class_T *next;
    for (itf2class_T *i2c = cl->class_itf2class; i2c != NULL; i2c = next)
    {
	next = i2c->i2c_next;
	vim_free(i2c);
    }

    for (int i = 0; i < cl->class_class_member_count; ++i)
    {
	ocmember_T *m = &cl->class_class_members[i];
	vim_free(m->ocm_name);
	vim_free(m->ocm_init);
	if (cl->class_members_tv != NULL)
	    clear_tv(&cl->class_members_tv[i]);
    }
    vim_free(cl->class_class_members);
    vim_free(cl->class_members_tv);

    for (int i = 0; i < cl->class_obj_member_count; ++i)
    {
	ocmember_T *m = &cl->class_obj_members[i];
	vim_free(m->ocm_name);
	vim_free(m->ocm_init);
    }
    vim_free(cl->class_obj_members);

    for (int i = 0; i < cl->class_class_function_count; ++i)
    {
	ufunc_T *uf = cl->class_class_functions[i];
	func_clear_free(uf, FALSE);
    }
    vim_free(cl->class_class_functions);

    for (int i = 0; i < cl->class_obj_method_count; ++i)
    {
	ufunc_T *uf = cl->class_obj_methods[i];
	func_clear_free(uf, FALSE);
    }
    vim_free(cl->class_obj_methods);

    clear_type_list(&cl->class_type_list);

    class_cleared(cl);

    vim_free(cl);
}

/*
 * Unreference a class.  Free it when the reference count goes down to zero.
 */
    void
class_unref(class_T *cl)
{
    if (cl != NULL && --cl->class_refcount <= 0 && cl->class_name != NULL)
	class_free(cl);
}

/*
 * Go through the list of all classes and free items without "copyID".
 */
    int
class_free_nonref(int copyID)
{
    int		did_free = FALSE;

    for (class_T *cl = first_class; cl != NULL; cl = next_nonref_class)
    {
	next_nonref_class = cl->class_next_used;
	if ((cl->class_copyID & COPYID_MASK) != (copyID & COPYID_MASK))
	{
	    // Free the class and items it contains.
	    class_free(cl);
	    did_free = TRUE;
	}
    }

    next_nonref_class = NULL;
    return did_free;
}

    int
set_ref_in_classes(int copyID)
{
    for (class_T *cl = first_class; cl != NULL; cl = cl->class_next_used)
	set_ref_in_item_class(cl, copyID, NULL, NULL);

    return FALSE;
}

static object_T *first_object = NULL;

/*
 * Call this function when an object has been created.  It will be added to the
 * list headed by "first_object".
 */
    void
object_created(object_T *obj)
{
    if (first_object != NULL)
    {
	obj->obj_next_used = first_object;
	first_object->obj_prev_used = obj;
    }
    first_object = obj;
}

static object_T	*next_nonref_obj = NULL;

/*
 * Call this function when an object has been cleared and is about to be freed.
 * It is removed from the list headed by "first_object".
 */
    void
object_cleared(object_T *obj)
{
    if (obj->obj_next_used != NULL)
	obj->obj_next_used->obj_prev_used = obj->obj_prev_used;
    if (obj->obj_prev_used != NULL)
	obj->obj_prev_used->obj_next_used = obj->obj_next_used;
    else if (first_object == obj)
	first_object = obj->obj_next_used;

    // update the next object to check if needed
    if (obj == next_nonref_obj)
	next_nonref_obj = obj->obj_next_used;
}

/*
 * Go through the list of all objects and free items without "copyID".
 */
    int
object_free_nonref(int copyID)
{
    int		did_free = FALSE;

    for (object_T *obj = first_object; obj != NULL; obj = next_nonref_obj)
    {
	next_nonref_obj = obj->obj_next_used;
	if ((obj->obj_copyID & COPYID_MASK) != (copyID & COPYID_MASK))
	{
	    // Free the object and items it contains.
	    object_clear(obj);
	    did_free = TRUE;
	}
    }

    next_nonref_obj = NULL;
    return did_free;
}

/*
 * Return TRUE when the class "cl", its base class or one of the implemented
 * interfaces matches the class "other_cl".
 */
    int
class_instance_of(class_T *cl, class_T *other_cl)
{
    if (cl == other_cl)
	return TRUE;

    // Recursively check the base classes.
    for (; cl != NULL; cl = cl->class_extends)
    {
	if (cl == other_cl)
	    return TRUE;
	// Check the implemented interfaces.
	for (int i = cl->class_interface_count - 1; i >= 0; --i)
	    if (cl->class_interfaces_cl[i] == other_cl)
		return TRUE;
    }

    return FALSE;
}

/*
 * "instanceof(object, classinfo)" function
 */
    void
f_instanceof(typval_T *argvars, typval_T *rettv)
{
    typval_T	*object_tv = &argvars[0];
    typval_T	*classinfo_tv = &argvars[1];
    listitem_T	*li;

    rettv->vval.v_number = VVAL_FALSE;

    if (check_for_object_arg(argvars, 0) == FAIL
	    || check_for_class_or_list_arg(argvars, 1) == FAIL)
	return;

    if (classinfo_tv->v_type == VAR_LIST)
    {
	FOR_ALL_LIST_ITEMS(classinfo_tv->vval.v_list, li)
	{
	    if (li->li_tv.v_type != VAR_CLASS)
	    {
		emsg(_(e_class_required));
		return;
	    }

	    if (class_instance_of(object_tv->vval.v_object->obj_class,
			li->li_tv.vval.v_class) == TRUE)
	    {
		rettv->vval.v_number = VVAL_TRUE;
		return;
	    }
	}
    }
    else if (classinfo_tv->v_type == VAR_CLASS)
    {
	rettv->vval.v_number = class_instance_of(object_tv->vval.v_object->obj_class,
		classinfo_tv->vval.v_class);
    }
}

#endif // FEAT_EVAL