view src/vim9type.c @ 33096:828bcb1a37e7 v9.0.1833

patch 9.0.1833: [security] runtime file fixes Commit: https://github.com/vim/vim/commit/816fbcc262687b81fc46f82f7bbeb1453addfe0c Author: Christian Brabandt <cb@256bit.org> Date: Thu Aug 31 23:52:30 2023 +0200 patch 9.0.1833: [security] runtime file fixes Problem: runtime files may execute code in current dir Solution: only execute, if not run from current directory The perl, zig and ruby filetype plugins and the zip and gzip autoload plugins may try to load malicious executable files from the current working directory. This is especially a problem on windows, where the current directory is implicitly in your $PATH and windows may even run a file with the extension `.bat` because of $PATHEXT. So make sure that we are not trying to execute a file from the current directory. If this would be the case, error out (for the zip and gzip) plugins or silently do not run those commands (for the ftplugins). This assumes, that only the current working directory is bad. For all other directories, it is assumed that those directories were intentionally set to the $PATH by the user. Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Fri, 01 Sep 2023 00:00:02 +0200
parents ba1b40b520e8
children def9fc5c92d1
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.
 */

/*
 * vim9type.c: handling of types
 */

#define USING_FLOAT_STUFF
#include "vim.h"

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

#ifdef VMS
# include <float.h>
#endif

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

/*
 * Allocate memory for a type_T and add the pointer to type_gap, so that it can
 * be easily freed later.
 */
    type_T *
get_type_ptr(garray_T *type_gap)
{
    type_T *type;

    if (ga_grow(type_gap, 1) == FAIL)
	return NULL;
    type = ALLOC_CLEAR_ONE(type_T);
    if (type == NULL)
	return NULL;

    ((type_T **)type_gap->ga_data)[type_gap->ga_len] = type;
    ++type_gap->ga_len;
    return type;
}

/*
 * Make a shallow copy of "type".
 * When allocation fails returns "type".
 */
    type_T *
copy_type(type_T *type, garray_T *type_gap)
{
    type_T *copy = get_type_ptr(type_gap);

    if (copy == NULL)
	return type;
    *copy = *type;
    copy->tt_flags &= ~TTFLAG_STATIC;

    if (type->tt_args != NULL
	   && func_type_add_arg_types(copy, type->tt_argcount, type_gap) == OK)
	for (int i = 0; i < type->tt_argcount; ++i)
	    copy->tt_args[i] = type->tt_args[i];

    return copy;
}

/*
 * Inner part of copy_type_deep().
 * When allocation fails returns "type".
 */
    static type_T *
copy_type_deep_rec(type_T *type, garray_T *type_gap, garray_T *seen_types)
{
    for (int i = 0; i < seen_types->ga_len; ++i)
	if (((type_T **)seen_types->ga_data)[i * 2] == type)
	    // seen this type before, return the copy we made
	    return ((type_T **)seen_types->ga_data)[i * 2 + 1];

    type_T *copy = copy_type(type, type_gap);
    if (ga_grow(seen_types, 1) == FAIL)
	return copy;
    ((type_T **)seen_types->ga_data)[seen_types->ga_len * 2] = type;
    ((type_T **)seen_types->ga_data)[seen_types->ga_len * 2 + 1] = copy;
    ++seen_types->ga_len;

    if (copy->tt_member != NULL)
	copy->tt_member = copy_type_deep_rec(copy->tt_member,
							 type_gap, seen_types);
    if (type->tt_args != NULL)
	for (int i = 0; i < type->tt_argcount; ++i)
	    copy->tt_args[i] = copy_type_deep_rec(copy->tt_args[i],
							 type_gap, seen_types);

    return copy;
}

/*
 * Make a deep copy of "type".
 * When allocation fails returns "type".
 */
    static type_T *
copy_type_deep(type_T *type, garray_T *type_gap)
{
    garray_T seen_types;
    // stores type pairs : a type we have seen and the copy used
    ga_init2(&seen_types, sizeof(type_T *) * 2, 20);

    type_T *res = copy_type_deep_rec(type, type_gap, &seen_types);

    ga_clear(&seen_types);
    return res;
}

    void
clear_type_list(garray_T *gap)
{
    while (gap->ga_len > 0)
	vim_free(((type_T **)gap->ga_data)[--gap->ga_len]);
    ga_clear(gap);
}

/*
 * Take a type that is using entries in a growarray and turn it into a type
 * with allocated entries.
 */
    type_T *
alloc_type(type_T *type)
{
    type_T *ret;

    if (type == NULL)
	return NULL;

    // A fixed type never contains allocated types, return as-is.
    if (type->tt_flags & TTFLAG_STATIC)
	return type;

    ret = ALLOC_ONE(type_T);
    *ret = *type;

    if (ret->tt_member != NULL)
	ret->tt_member = alloc_type(ret->tt_member);

    if (type->tt_args != NULL)
    {
	int i;

	ret->tt_args = ALLOC_MULT(type_T *, type->tt_argcount);
	if (ret->tt_args != NULL)
	    for (i = 0; i < type->tt_argcount; ++i)
		ret->tt_args[i] = alloc_type(type->tt_args[i]);
    }

    return ret;
}

/*
 * Free a type that was created with alloc_type().
 */
    void
free_type(type_T *type)
{
    int i;

    if (type == NULL || (type->tt_flags & TTFLAG_STATIC))
	return;
    if (type->tt_args != NULL)
    {
	for (i = 0; i < type->tt_argcount; ++i)
	    free_type(type->tt_args[i]);
	vim_free(type->tt_args);
    }

    free_type(type->tt_member);

    vim_free(type);
}

/*
 * Return TRUE if "type" is to be recursed into for setting the type.
 */
    static int
set_tv_type_recurse(type_T *type)
{
    return type->tt_member != NULL
		&& (type->tt_member->tt_type == VAR_DICT
				       || type->tt_member->tt_type == VAR_LIST)
		&& type->tt_member->tt_member != NULL
		&& type->tt_member->tt_member != &t_any
		&& type->tt_member->tt_member != &t_unknown;
}

/*
 * Set the type of "tv" to "type" if it is a list or dict.
 */
    void
set_tv_type(typval_T *tv, type_T *type)
{
    if (tv->v_type == VAR_DICT && tv->vval.v_dict != NULL)
    {
	dict_T *d = tv->vval.v_dict;

	if (d->dv_type != type)
	{
	    free_type(d->dv_type);
	    d->dv_type = alloc_type(type);
	    if (set_tv_type_recurse(type))
	    {
		int		todo = (int)d->dv_hashtab.ht_used;
		hashitem_T	*hi;
		dictitem_T	*di;

		FOR_ALL_HASHTAB_ITEMS(&d->dv_hashtab, hi, todo)
		{
		    if (!HASHITEM_EMPTY(hi))
		    {
			--todo;
			di = HI2DI(hi);
			set_tv_type(&di->di_tv, type->tt_member);
		    }
		}
	    }
	}
    }
    else if (tv->v_type == VAR_LIST && tv->vval.v_list != NULL)
    {
	list_T *l = tv->vval.v_list;

	if (l->lv_type != type)
	{
	    free_type(l->lv_type);
	    l->lv_type = alloc_type(type);
	    if (l->lv_first != &range_list_item && set_tv_type_recurse(type))
	    {
		listitem_T	*li;

		FOR_ALL_LIST_ITEMS(l, li)
		    set_tv_type(&li->li_tv, type->tt_member);
	    }
	}
    }
}

    type_T *
get_list_type(type_T *member_type, garray_T *type_gap)
{
    type_T *type;

    // recognize commonly used types
    if (member_type == NULL || member_type->tt_type == VAR_ANY)
	return &t_list_any;
    if (member_type->tt_type == VAR_VOID
	    || member_type->tt_type == VAR_UNKNOWN)
	return &t_list_empty;
    if (member_type->tt_type == VAR_BOOL)
	return &t_list_bool;
    if (member_type->tt_type == VAR_NUMBER)
	return &t_list_number;
    if (member_type->tt_type == VAR_STRING)
	return &t_list_string;

    // Not a common type, create a new entry.
    type = get_type_ptr(type_gap);
    if (type == NULL)
	return &t_any;
    type->tt_type = VAR_LIST;
    type->tt_member = member_type;
    type->tt_argcount = 0;
    type->tt_args = NULL;
    return type;
}

    type_T *
get_dict_type(type_T *member_type, garray_T *type_gap)
{
    type_T *type;

    // recognize commonly used types
    if (member_type == NULL || member_type->tt_type == VAR_ANY)
	return &t_dict_any;
    if (member_type->tt_type == VAR_VOID
	    || member_type->tt_type == VAR_UNKNOWN)
	return &t_dict_empty;
    if (member_type->tt_type == VAR_BOOL)
	return &t_dict_bool;
    if (member_type->tt_type == VAR_NUMBER)
	return &t_dict_number;
    if (member_type->tt_type == VAR_STRING)
	return &t_dict_string;

    // Not a common type, create a new entry.
    type = get_type_ptr(type_gap);
    if (type == NULL)
	return &t_any;
    type->tt_type = VAR_DICT;
    type->tt_member = member_type;
    type->tt_argcount = 0;
    type->tt_args = NULL;
    return type;
}

/*
 * Allocate a new type for a function.
 */
    type_T *
alloc_func_type(type_T *ret_type, int argcount, garray_T *type_gap)
{
    type_T *type = get_type_ptr(type_gap);

    if (type == NULL)
	return &t_any;
    type->tt_type = VAR_FUNC;
    type->tt_member = ret_type == NULL ? &t_unknown : ret_type;
    type->tt_argcount = argcount;
    type->tt_args = NULL;
    return type;
}

/*
 * Get a function type, based on the return type "ret_type".
 * "argcount" must be -1 or 0, a predefined type can be used.
 */
    type_T *
get_func_type(type_T *ret_type, int argcount, garray_T *type_gap)
{
    // recognize commonly used types
    if (ret_type == &t_unknown || ret_type == NULL)
    {
	// (argcount == 0) is not possible
	return &t_func_unknown;
    }
    if (ret_type == &t_void)
    {
	if (argcount == 0)
	    return &t_func_0_void;
	else
	    return &t_func_void;
    }
    if (ret_type == &t_any)
    {
	if (argcount == 0)
	    return &t_func_0_any;
	else
	    return &t_func_any;
    }
    if (ret_type == &t_number)
    {
	if (argcount == 0)
	    return &t_func_0_number;
	else
	    return &t_func_number;
    }
    if (ret_type == &t_string)
    {
	if (argcount == 0)
	    return &t_func_0_string;
	else
	    return &t_func_string;
    }

    return alloc_func_type(ret_type, argcount, type_gap);
}

/*
 * For a function type, reserve space for "argcount" argument types (including
 * vararg).
 */
    int
func_type_add_arg_types(
	type_T	    *functype,
	int	    argcount,
	garray_T    *type_gap)
{
    // To make it easy to free the space needed for the argument types, add the
    // pointer to type_gap.
    if (ga_grow(type_gap, 1) == FAIL)
	return FAIL;
    functype->tt_args = ALLOC_CLEAR_MULT(type_T *, argcount);
    if (functype->tt_args == NULL)
	return FAIL;
    ((type_T **)type_gap->ga_data)[type_gap->ga_len] =
						     (void *)functype->tt_args;
    ++type_gap->ga_len;
    return OK;
}

/*
 * Return TRUE if "type" is NULL, any or unknown.
 * This also works for const (comparing with &t_any and &t_unknown doesn't).
 */
    int
type_any_or_unknown(type_T *type)
{
    return type == NULL || type->tt_type == VAR_ANY
					       || type->tt_type == VAR_UNKNOWN;
}

/*
 * Get a type_T for a typval_T.
 * "type_gap" is used to temporarily create types in.
 * When "flags" has TVTT_DO_MEMBER also get the member type, otherwise use
 * "any".
 * When "flags" has TVTT_MORE_SPECIFIC get the more specific member type if it
 * is "any".
 */
    static type_T *
typval2type_int(typval_T *tv, int copyID, garray_T *type_gap, int flags)
{
    type_T  *type;
    type_T  *member_type = NULL;
    class_T *class_type = NULL;
    int	    argcount = 0;
    int	    min_argcount = 0;

    if (tv->v_type == VAR_NUMBER)
	return &t_number;
    if (tv->v_type == VAR_BOOL)
	return &t_bool;
    if (tv->v_type == VAR_SPECIAL)
    {
	if (tv->vval.v_number == VVAL_NULL)
	    return &t_null;
	if (tv->vval.v_number == VVAL_NONE)
	    return &t_none;
	if (tv->vval.v_number == VVAL_TRUE
		|| tv->vval.v_number == VVAL_FALSE)
	    return &t_bool;
	return &t_unknown;
    }
    if (tv->v_type == VAR_STRING)
	return &t_string;
    if (tv->v_type == VAR_BLOB)
    {
	if (tv->vval.v_blob == NULL)
	    return &t_blob_null;
	return &t_blob;
    }

    if (tv->v_type == VAR_LIST)
    {
	list_T	    *l = tv->vval.v_list;
	listitem_T  *li;

	// An empty list has type list<unknown>, unless the type was specified
	// and is not list<any>.  This matters when assigning to a variable
	// with a specific list type.
	if (l == NULL || (l->lv_first == NULL
		   && (l->lv_type == NULL || l->lv_type->tt_member == &t_any)))
	    return &t_list_empty;
	if ((flags & TVTT_DO_MEMBER) == 0)
	    return &t_list_any;
	// If the type is list<any> go through the members, it may end up a
	// more specific type.
	if (l->lv_type != NULL && (l->lv_first == NULL
					   || (flags & TVTT_MORE_SPECIFIC) == 0
					   || l->lv_type->tt_member != &t_any))
	    // make a copy, lv_type may be freed if the list is freed
	    return copy_type_deep(l->lv_type, type_gap);
	if (l->lv_first == &range_list_item)
	    return &t_list_number;
	if (l->lv_copyID == copyID)
	    // avoid recursion
	    return &t_list_any;
	l->lv_copyID = copyID;

	// Use the common type of all members.
	member_type = typval2type(&l->lv_first->li_tv, copyID, type_gap,
							       TVTT_DO_MEMBER);
	for (li = l->lv_first->li_next; li != NULL; li = li->li_next)
	    common_type(typval2type(&li->li_tv, copyID, type_gap,
							       TVTT_DO_MEMBER),
					  member_type, &member_type, type_gap);
	return get_list_type(member_type, type_gap);
    }

    if (tv->v_type == VAR_DICT)
    {
	dict_iterator_T iter;
	typval_T	*value;
	dict_T		*d = tv->vval.v_dict;

	if (d == NULL || (d->dv_hashtab.ht_used == 0 && d->dv_type == NULL))
	    return &t_dict_empty;
	if ((flags & TVTT_DO_MEMBER) == 0)
	    return &t_dict_any;
	// If the type is dict<any> go through the members, it may end up a
	// more specific type.
	if (d->dv_type != NULL && (d->dv_hashtab.ht_used == 0
					   || (flags & TVTT_MORE_SPECIFIC) == 0
					   || d->dv_type->tt_member != &t_any))
	    return d->dv_type;
	if (d->dv_copyID == copyID)
	    // avoid recursion
	    return &t_dict_any;
	d->dv_copyID = copyID;

	// Use the common type of all values.
	dict_iterate_start(tv, &iter);
	dict_iterate_next(&iter, &value);
	member_type = typval2type(value, copyID, type_gap, TVTT_DO_MEMBER);
	while (dict_iterate_next(&iter, &value) != NULL)
	    common_type(typval2type(value, copyID, type_gap, TVTT_DO_MEMBER),
					  member_type, &member_type, type_gap);
	return get_dict_type(member_type, type_gap);
    }

    if (tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
    {
	char_u	*name = NULL;
	ufunc_T *ufunc = NULL;

	if (tv->v_type == VAR_PARTIAL && tv->vval.v_partial != NULL)
	{
	    if (tv->vval.v_partial->pt_func != NULL)
		ufunc = tv->vval.v_partial->pt_func;
	    else
		name = tv->vval.v_partial->pt_name;
	}
	else
	    name = tv->vval.v_string;
	if (name == NULL && ufunc == NULL)
	    return &t_func_unknown;
	if (name != NULL)
	{
	    int idx = find_internal_func(name);

	    if (idx >= 0)
	    {
		type_T *decl_type;  // unused

		internal_func_get_argcount(idx, &argcount, &min_argcount);
		member_type = internal_func_ret_type(idx, 0, NULL, &decl_type,
								     type_gap);
	    }
	    else
		ufunc = find_func(name, FALSE);
	}
	if (ufunc != NULL)
	{
	    // May need to get the argument types from default values by
	    // compiling the function.
	    if (ufunc->uf_def_status == UF_TO_BE_COMPILED
			    && compile_def_function(ufunc, TRUE, CT_NONE, NULL)
								       == FAIL)
		return NULL;
	    if (ufunc->uf_func_type == NULL)
		set_function_type(ufunc);
	    if (ufunc->uf_func_type != NULL)
	    {
		if (tv->v_type == VAR_PARTIAL && tv->vval.v_partial != NULL
					    && tv->vval.v_partial->pt_argc > 0)
		{
		    type = get_type_ptr(type_gap);
		    if (type == NULL)
			return NULL;
		    *type = *ufunc->uf_func_type;
		    if (type->tt_argcount >= 0)
		    {
			type->tt_argcount -= tv->vval.v_partial->pt_argc;
			type->tt_min_argcount -= tv->vval.v_partial->pt_argc;
			if (type->tt_argcount > 0
				&& func_type_add_arg_types(type,
					    type->tt_argcount, type_gap) == OK)
			    for (int i = 0; i < type->tt_argcount; ++i)
				type->tt_args[i] =
					ufunc->uf_func_type->tt_args[
					      i + tv->vval.v_partial->pt_argc];
		    }
		    return type;
		}
		return ufunc->uf_func_type;
	    }
	}
    }

    if (tv->v_type == VAR_CLASS)
	class_type = tv->vval.v_class;
    else if (tv->v_type == VAR_OBJECT && tv->vval.v_object != NULL)
	class_type = tv->vval.v_object->obj_class;

    type = get_type_ptr(type_gap);
    if (type == NULL)
	return NULL;
    type->tt_type = tv->v_type;
    type->tt_argcount = argcount;
    type->tt_min_argcount = min_argcount;
    if (tv->v_type == VAR_PARTIAL && tv->vval.v_partial != NULL
					    && tv->vval.v_partial->pt_argc > 0)
    {
	type->tt_argcount -= tv->vval.v_partial->pt_argc;
	type->tt_min_argcount -= tv->vval.v_partial->pt_argc;
    }
    type->tt_member = member_type;
    type->tt_class = class_type;

    return type;
}

/*
 * Return TRUE if "tv" is not a bool but should be converted to bool.
 */
    int
need_convert_to_bool(type_T *type, typval_T *tv)
{
    return type != NULL && type == &t_bool && tv->v_type != VAR_BOOL
	    && (tv->v_type == VAR_NUMBER
		       && (tv->vval.v_number == 0 || tv->vval.v_number == 1));
}

/*
 * Get a type_T for a typval_T.
 * "type_list" is used to temporarily create types in.
 * When "flags" has TVTT_DO_MEMBER also get the member type, otherwise use
 * "any".
 * When "flags" has TVTT_MORE_SPECIFIC get the most specific member type.
 */
    type_T *
typval2type(typval_T *tv, int copyID, garray_T *type_gap, int flags)
{
    type_T *type = typval2type_int(tv, copyID, type_gap, flags);

    if (type == NULL)
	return NULL;

    if (type != &t_bool && (tv->v_type == VAR_NUMBER
		&& (tv->vval.v_number == 0 || tv->vval.v_number == 1)))
	// Number 0 and 1 and expression with "&&" or "||" can also be used
	// for bool.
	type = &t_number_bool;
    else if (type != &t_float && tv->v_type == VAR_NUMBER)
	// A number can also be used for float.
	type = &t_number_float;
    return type;
}

/*
 * Return TRUE if "type" can be used for a variable declaration.
 * Give an error and return FALSE if not.
 */
    int
valid_declaration_type(type_T *type)
{
    if (type->tt_type == VAR_SPECIAL  // null, none
	    || type->tt_type == VAR_VOID)
    {
	char *tofree = NULL;
	char *name = type_name(type, &tofree);
	semsg(_(e_invalid_type_for_object_member_str), name);
	vim_free(tofree);
	return FALSE;
    }
    return TRUE;
}

/*
 * Get a type_T for a typval_T, used for v: variables.
 * "type_list" is used to temporarily create types in.
 */
    type_T *
typval2type_vimvar(typval_T *tv, garray_T *type_gap)
{
    if (tv->v_type == VAR_LIST)  // e.g. for v:oldfiles
	return &t_list_string;
    if (tv->v_type == VAR_DICT)  // e.g. for v:event
	return &t_dict_any;
    return typval2type(tv, get_copyID(), type_gap, TVTT_DO_MEMBER);
}

    int
check_typval_arg_type(
	type_T	    *expected,
	typval_T    *actual_tv,
	char	    *func_name,
	int	    arg_idx)
{
    where_T	where = WHERE_INIT;

    if (arg_idx > 0)
    {
	where.wt_index = arg_idx;
	where.wt_kind = WT_ARGUMENT;
    }
    where.wt_func_name = func_name;
    return check_typval_type(expected, actual_tv, where);
}

/*
 * Return FAIL if "expected" and "actual" don't match.
 * When "argidx" > 0 it is included in the error message.
 */
    int
check_typval_type(type_T *expected, typval_T *actual_tv, where_T where)
{
    garray_T	type_list;
    type_T	*actual_type;
    int		res = FAIL;

    if (expected == NULL)
	return OK;  // didn't expect anything.
		    //
    ga_init2(&type_list, sizeof(type_T *), 10);

    // A null_function and null_partial are special cases, they can be used to
    // clear a variable.
    if ((actual_tv->v_type == VAR_FUNC && actual_tv->vval.v_string == NULL)
	    || (actual_tv->v_type == VAR_PARTIAL
					 && actual_tv->vval.v_partial == NULL))
	actual_type = &t_func_unknown;
    else
	// When the actual type is list<any> or dict<any> go through the values
	// to possibly get a more specific type.
	actual_type = typval2type(actual_tv, get_copyID(), &type_list,
					  TVTT_DO_MEMBER | TVTT_MORE_SPECIFIC);
    if (actual_type != NULL)
    {
	res = check_type_maybe(expected, actual_type, TRUE, where);
	if (res == MAYBE && !(actual_type->tt_type == VAR_FUNC
				      && actual_type->tt_member == &t_unknown))
	{
	    // If a type check is needed that means assigning "any" or
	    // "unknown" to a more specific type, which fails here.
	    // Execpt when it looks like a lambda, since they have an
	    // incomplete type.
	    type_mismatch_where(expected, actual_type, where);
	    res = FAIL;
	}
    }
    clear_type_list(&type_list);
    return res;
}

    void
arg_type_mismatch(type_T *expected, type_T *actual, int arg_idx)
{
    where_T	where = WHERE_INIT;

    if (arg_idx > 0)
    {
	where.wt_index = arg_idx;
	where.wt_kind = WT_ARGUMENT;
    }
    type_mismatch_where(expected, actual, where);
}

    void
type_mismatch_where(type_T *expected, type_T *actual, where_T where)
{
    char *tofree1, *tofree2;
    char *typename1 = type_name(expected, &tofree1);
    char *typename2 = type_name(actual, &tofree2);

    switch (where.wt_kind)
    {
	case WT_MEMBER:
	    semsg(_(e_member_str_type_mismatch_expected_str_but_got_str),
		    where.wt_func_name, typename1, typename2);
	    break;
	case WT_METHOD:
	    semsg(_(e_method_str_type_mismatch_expected_str_but_got_str),
		    where.wt_func_name, typename1, typename2);
	    break;
	case WT_VARIABLE:
	    if (where.wt_func_name == NULL)
		semsg(_(e_variable_nr_type_mismatch_expected_str_but_got_str),
			where.wt_index, typename1, typename2);
	    else
		semsg(_(e_variable_nr_type_mismatch_expected_str_but_got_str_in_str),
			where.wt_index, typename1, typename2, where.wt_func_name);
	    break;
	case WT_ARGUMENT:
	    if (where.wt_func_name == NULL)
		semsg(_(e_argument_nr_type_mismatch_expected_str_but_got_str),
			where.wt_index, typename1, typename2);
	    else
		semsg(_(e_argument_nr_type_mismatch_expected_str_but_got_str_in_str),
			where.wt_index, typename1, typename2, where.wt_func_name);
	    break;
	case WT_UNKNOWN:
	    if (where.wt_func_name == NULL)
		semsg(_(e_type_mismatch_expected_str_but_got_str),
			typename1, typename2);
	    else
		semsg(_(e_type_mismatch_expected_str_but_got_str_in_str),
			typename1, typename2, where.wt_func_name);
	    break;
    }

    vim_free(tofree1);
    vim_free(tofree2);
}

/*
 * Check if the expected and actual types match.
 * Does not allow for assigning "any" to a specific type.
 * When "argidx" > 0 it is included in the error message.
 * Return OK if types match.
 * Return FAIL if types do not match.
 */
    int
check_type(
	type_T	*expected,
	type_T	*actual,
	int	give_msg,
	where_T where)
{
    int ret = check_type_maybe(expected, actual, give_msg, where);

    return ret == MAYBE ? OK : ret;
}

/*
 * As check_type() but return MAYBE when a runtime type check should be used
 * when compiling.
 */
    int
check_type_maybe(
	type_T	*expected,
	type_T	*actual,
	int	give_msg,
	where_T where)
{
    int ret = OK;

    // When expected is "unknown" we accept any actual type.
    // When expected is "any" we accept any actual type except "void".
    if (expected->tt_type != VAR_UNKNOWN
	    && !(expected->tt_type == VAR_ANY && actual->tt_type != VAR_VOID))

    {
	// tt_type should match, except that a "partial" can be assigned to a
	// variable with type "func".
	// And "unknown" (using global variable) and "any" need a runtime type
	// check.
	if (!(expected->tt_type == actual->tt_type
		    || actual->tt_type == VAR_UNKNOWN
		    || actual->tt_type == VAR_ANY
		    || (expected->tt_type == VAR_FUNC
					   && actual->tt_type == VAR_PARTIAL)))
	{
	    if (expected->tt_type == VAR_BOOL
					&& (actual->tt_flags & TTFLAG_BOOL_OK))
		// Using number 0 or 1 for bool is OK.
		return OK;
	    if (expected->tt_type == VAR_FLOAT
		    && actual->tt_type == VAR_NUMBER
		    && ((expected->tt_flags & TTFLAG_NUMBER_OK)
			     || (actual->tt_flags & TTFLAG_FLOAT_OK)))
		// Using a number where a float is expected is OK here.
		return OK;
	    if (give_msg)
		type_mismatch_where(expected, actual, where);
	    return FAIL;
	}
	if (expected->tt_type == VAR_DICT || expected->tt_type == VAR_LIST)
	{
	    // "unknown" is used for an empty list or dict
	    if (actual->tt_member != NULL && actual->tt_member != &t_unknown)
		ret = check_type_maybe(expected->tt_member, actual->tt_member,
								 FALSE, where);
	}
	else if (expected->tt_type == VAR_FUNC && actual != &t_any)
	{
	    // If the return type is unknown it can be anything, including
	    // nothing, thus there is no point in checking.
	    if (expected->tt_member != &t_unknown)
	    {
		if (actual->tt_member != NULL
					    && actual->tt_member != &t_unknown)
		    ret = check_type_maybe(expected->tt_member,
					      actual->tt_member, FALSE, where);
		else
		    ret = MAYBE;
	    }
	    if (ret != FAIL && expected->tt_argcount != -1
		    && actual->tt_min_argcount != -1
		    && (actual->tt_argcount == -1
			|| (actual->tt_argcount < expected->tt_min_argcount
			    || actual->tt_argcount > expected->tt_argcount)))
		ret = FAIL;
	    if (ret != FAIL && expected->tt_args != NULL
						    && actual->tt_args != NULL)
	    {
		int i;

		for (i = 0; i < expected->tt_argcount
					       && i < actual->tt_argcount; ++i)
		    // Allow for using "any" argument type, lambda's have them.
		    if (actual->tt_args[i] != &t_any && check_type(
			    expected->tt_args[i], actual->tt_args[i], FALSE,
								where) == FAIL)
		    {
			ret = FAIL;
			break;
		    }
	    }
	    if (ret == OK && expected->tt_argcount >= 0
						  && actual->tt_argcount == -1)
		// check the argument count at runtime
		ret = MAYBE;
	}
	else if (expected->tt_type == VAR_OBJECT)
	{
	    if (actual->tt_type == VAR_ANY)
		return MAYBE;	// use runtime type check
	    if (actual->tt_type != VAR_OBJECT)
		return FAIL;	// don't use tt_class
	    if (actual->tt_class == NULL)
		return OK;	// A null object matches

	    if (class_instance_of(actual->tt_class, expected->tt_class) == FALSE)
		ret = FAIL;
	}

	if (ret == FAIL && give_msg)
	    type_mismatch_where(expected, actual, where);
    }

    if (ret == OK && expected->tt_type != VAR_UNKNOWN
	    && expected->tt_type != VAR_ANY
	    && (actual->tt_type == VAR_UNKNOWN || actual->tt_type == VAR_ANY))
	// check the type at runtime
	ret = MAYBE;

    return ret;
}

/*
 * Check that the arguments of "type" match "argvars[argcount]".
 * "base_tv" is from "expr->Func()".
 * Return OK/FAIL.
 */
    int
check_argument_types(
	type_T	    *type,
	typval_T    *argvars,
	int	    argcount,
	typval_T    *base_tv,
	char_u	    *name)
{
    int	    varargs = (type->tt_flags & TTFLAG_VARARGS) ? 1 : 0;
    int	    i;
    int	    totcount = argcount + (base_tv == NULL ? 0 : 1);

    if (type->tt_type != VAR_FUNC && type->tt_type != VAR_PARTIAL)
	return OK;  // just in case
    if (totcount < type->tt_min_argcount - varargs)
    {
	emsg_funcname(e_not_enough_arguments_for_function_str, name);
	return FAIL;
    }
    if (!varargs && type->tt_argcount >= 0 && totcount > type->tt_argcount)
    {
	emsg_funcname(e_too_many_arguments_for_function_str, name);
	return FAIL;
    }
    if (type->tt_args == NULL)
	return OK;  // cannot check


    for (i = 0; i < totcount; ++i)
    {
	type_T	    *expected;
	typval_T    *tv;

	if (base_tv != NULL)
	{
	    if (i == 0)
		tv = base_tv;
	    else
		tv = &argvars[i - 1];
	}
	else
	    tv = &argvars[i];
	if (varargs && i >= type->tt_argcount - 1)
	{
	    expected = type->tt_args[type->tt_argcount - 1];
	    if (expected != NULL && expected->tt_type == VAR_LIST)
		expected = expected->tt_member;
	    if (expected == NULL)
		expected = &t_any;
	}
	else
	    expected = type->tt_args[i];

	// check the type, unless the value is v:none
	if ((tv->v_type != VAR_SPECIAL || tv->vval.v_number != VVAL_NONE)
		   && check_typval_arg_type(expected, tv, NULL, i + 1) == FAIL)
	    return FAIL;
    }
    return OK;
}

/*
 * Skip over a type definition and return a pointer to just after it.
 * When "optional" is TRUE then a leading "?" is accepted.
 */
    char_u *
skip_type(char_u *start, int optional)
{
    char_u *p = start;

    if (optional && *p == '?')
	++p;

    // Also skip over "." for imported classes: "import.ClassName".
    while (ASCII_ISALNUM(*p) || *p == '_' || *p == '.')
	++p;

    // Skip over "<type>"; this is permissive about white space.
    if (*skipwhite(p) == '<')
    {
	p = skipwhite(p);
	p = skip_type(skipwhite(p + 1), FALSE);
	p = skipwhite(p);
	if (*p == '>')
	    ++p;
    }
    else if ((*p == '(' || (*p == ':' && VIM_ISWHITE(p[1])))
					     && STRNCMP("func", start, 4) == 0)
    {
	if (*p == '(')
	{
	    // handle func(args): type
	    ++p;
	    while (*p != ')' && *p != NUL)
	    {
		char_u *sp = p;

		if (STRNCMP(p, "...", 3) == 0)
		    p += 3;
		p = skip_type(p, TRUE);
		if (p == sp)
		    return p;  // syntax error
		if (*p == ',')
		    p = skipwhite(p + 1);
	    }
	    if (*p == ')')
	    {
		if (p[1] == ':')
		    p = skip_type(skipwhite(p + 2), FALSE);
		else
		    ++p;
	    }
	}
	else
	{
	    // handle func: return_type
	    p = skip_type(skipwhite(p + 1), FALSE);
	}
    }

    return p;
}

/*
 * Parse the member type: "<type>" and return "type" with the member set.
 * Use "type_gap" if a new type needs to be added.
 * "info" is extra information for an error message.
 * Returns NULL in case of failure.
 */
    static type_T *
parse_type_member(
	char_u	    **arg,
	type_T	    *type,
	garray_T    *type_gap,
	int	    give_error,
	char	    *info)
{
    char_u  *arg_start = *arg;
    type_T  *member_type;
    int	    prev_called_emsg = called_emsg;

    if (**arg != '<')
    {
	if (give_error)
	{
	    if (*skipwhite(*arg) == '<')
		semsg(_(e_no_white_space_allowed_before_str_str), "<", *arg);
	    else
		semsg(_(e_missing_type_after_str), info);
	}
	return NULL;
    }
    *arg = skipwhite(*arg + 1);

    member_type = parse_type(arg, type_gap, give_error);
    if (member_type == NULL)
	return NULL;

    *arg = skipwhite(*arg);
    if (**arg != '>' && called_emsg == prev_called_emsg)
    {
	if (give_error)
	    semsg(_(e_missing_gt_after_type_str), arg_start);
	return NULL;
    }
    ++*arg;

    if (type->tt_type == VAR_LIST)
	return get_list_type(member_type, type_gap);
    return get_dict_type(member_type, type_gap);
}

/*
 * Parse a type at "arg" and advance over it.
 * When "give_error" is TRUE give error messages, otherwise be quiet.
 * Return NULL for failure.
 */
    type_T *
parse_type(char_u **arg, garray_T *type_gap, int give_error)
{
    char_u  *p = *arg;
    size_t  len;

    // Skip over the first word.
    while (ASCII_ISALNUM(*p) || *p == '_')
	++p;
    len = p - *arg;

    switch (**arg)
    {
	case 'a':
	    if (len == 3 && STRNCMP(*arg, "any", len) == 0)
	    {
		*arg += len;
		return &t_any;
	    }
	    break;
	case 'b':
	    if (len == 4 && STRNCMP(*arg, "bool", len) == 0)
	    {
		*arg += len;
		return &t_bool;
	    }
	    if (len == 4 && STRNCMP(*arg, "blob", len) == 0)
	    {
		*arg += len;
		return &t_blob;
	    }
	    break;
	case 'c':
	    if (len == 7 && STRNCMP(*arg, "channel", len) == 0)
	    {
		*arg += len;
		return &t_channel;
	    }
	    break;
	case 'd':
	    if (len == 4 && STRNCMP(*arg, "dict", len) == 0)
	    {
		*arg += len;
		return parse_type_member(arg, &t_dict_any,
						 type_gap, give_error, "dict");
	    }
	    break;
	case 'f':
	    if (len == 5 && STRNCMP(*arg, "float", len) == 0)
	    {
		*arg += len;
		return &t_float;
	    }
	    if (len == 4 && STRNCMP(*arg, "func", len) == 0)
	    {
		type_T  *type;
		type_T  *ret_type = &t_unknown;
		int	argcount = -1;
		int	flags = 0;
		int	first_optional = -1;
		type_T	*arg_type[MAX_FUNC_ARGS + 1];

		// func({type}, ...{type}): {type}
		*arg += len;
		if (**arg == '(')
		{
		    // "func" may or may not return a value, "func()" does
		    // not return a value.
		    ret_type = &t_void;

		    p = ++*arg;
		    argcount = 0;
		    while (*p != NUL && *p != ')')
		    {
			if (*p == '?')
			{
			    if (first_optional == -1)
				first_optional = argcount;
			    ++p;
			}
			else if (STRNCMP(p, "...", 3) == 0)
			{
			    flags |= TTFLAG_VARARGS;
			    p += 3;
			}
			else if (first_optional != -1)
			{
			    if (give_error)
				emsg(_(e_mandatory_argument_after_optional_argument));
			    return NULL;
			}

			type = parse_type(&p, type_gap, give_error);
			if (type == NULL)
			    return NULL;
			arg_type[argcount++] = type;

			// Nothing comes after "...{type}".
			if (flags & TTFLAG_VARARGS)
			    break;

			if (*p != ',' && *skipwhite(p) == ',')
			{
			    if (give_error)
				semsg(_(e_no_white_space_allowed_before_str_str),
								       ",", p);
			    return NULL;
			}
			if (*p == ',')
			{
			    ++p;
			    if (!VIM_ISWHITE(*p))
			    {
				if (give_error)
				    semsg(_(e_white_space_required_after_str_str),
								   ",", p - 1);
				return NULL;
			    }
			}
			p = skipwhite(p);
			if (argcount == MAX_FUNC_ARGS)
			{
			    if (give_error)
				emsg(_(e_too_many_argument_types));
			    return NULL;
			}
		    }

		    p = skipwhite(p);
		    if (*p != ')')
		    {
			if (give_error)
			    emsg(_(e_missing_closing_paren));
			return NULL;
		    }
		    *arg = p + 1;
		}
		if (**arg == ':')
		{
		    // parse return type
		    ++*arg;
		    if (!VIM_ISWHITE(**arg) && give_error)
			semsg(_(e_white_space_required_after_str_str),
								":", *arg - 1);
		    *arg = skipwhite(*arg);
		    ret_type = parse_type(arg, type_gap, give_error);
		    if (ret_type == NULL)
			return NULL;
		}
		if (flags == 0 && first_optional == -1 && argcount <= 0)
		    type = get_func_type(ret_type, argcount, type_gap);
		else
		{
		    type = alloc_func_type(ret_type, argcount, type_gap);
		    type->tt_flags = flags;
		    if (argcount > 0)
		    {
			type->tt_argcount = argcount;
			type->tt_min_argcount = first_optional == -1
						   ? argcount : first_optional;
			if (func_type_add_arg_types(type, argcount,
							     type_gap) == FAIL)
			    return NULL;
			mch_memmove(type->tt_args, arg_type,
						  sizeof(type_T *) * argcount);
		    }
		}
		return type;
	    }
	    break;
	case 'j':
	    if (len == 3 && STRNCMP(*arg, "job", len) == 0)
	    {
		*arg += len;
		return &t_job;
	    }
	    break;
	case 'l':
	    if (len == 4 && STRNCMP(*arg, "list", len) == 0)
	    {
		*arg += len;
		return parse_type_member(arg, &t_list_any,
						 type_gap, give_error, "list");
	    }
	    break;
	case 'n':
	    if (len == 6 && STRNCMP(*arg, "number", len) == 0)
	    {
		*arg += len;
		return &t_number;
	    }
	    break;
	case 's':
	    if (len == 6 && STRNCMP(*arg, "string", len) == 0)
	    {
		*arg += len;
		return &t_string;
	    }
	    break;
	case 'v':
	    if (len == 4 && STRNCMP(*arg, "void", len) == 0)
	    {
		*arg += len;
		return &t_void;
	    }
	    break;
    }

    // It can be a class or interface name, possibly imported.
    typval_T tv;
    tv.v_type = VAR_UNKNOWN;
    if (eval_variable_import(*arg, &tv) == OK)
    {
	if (tv.v_type == VAR_CLASS && tv.vval.v_class != NULL)
	{
	    type_T *type = get_type_ptr(type_gap);
	    if (type != NULL)
	    {
		// Although the name is that of a class or interface, the type
		// uses will be an object.
		type->tt_type = VAR_OBJECT;
		type->tt_class = tv.vval.v_class;
		clear_tv(&tv);

		*arg += len;
		// Skip over ".ClassName".
		while (ASCII_ISALNUM(**arg) || **arg == '_' || **arg == '.')
		    ++*arg;

		return type;
	    }
	}

	clear_tv(&tv);
    }

    if (give_error)
	semsg(_(e_type_not_recognized_str), *arg);
    return NULL;
}

/*
 * Check if "type1" and "type2" are exactly the same.
 * "flags" can have ETYPE_ARG_UNKNOWN, which means that an unknown argument
 * type in "type1" is accepted.
 */
    int
equal_type(type_T *type1, type_T *type2, int flags)
{
    int i;

    if (type1 == NULL || type2 == NULL)
	return FALSE;
    if (type1->tt_type != type2->tt_type)
	return FALSE;
    switch (type1->tt_type)
    {
	case VAR_UNKNOWN:
	case VAR_ANY:
	case VAR_VOID:
	case VAR_SPECIAL:
	case VAR_BOOL:
	case VAR_NUMBER:
	case VAR_FLOAT:
	case VAR_STRING:
	case VAR_BLOB:
	case VAR_JOB:
	case VAR_CHANNEL:
	case VAR_INSTR:
	case VAR_CLASS:
	case VAR_OBJECT:
	    break;  // not composite is always OK
	case VAR_LIST:
	case VAR_DICT:
	    return equal_type(type1->tt_member, type2->tt_member, flags);
	case VAR_FUNC:
	case VAR_PARTIAL:
	    if (!equal_type(type1->tt_member, type2->tt_member, flags)
		    || type1->tt_argcount != type2->tt_argcount)
		return FALSE;
	    if (type1->tt_argcount < 0
			   || type1->tt_args == NULL || type2->tt_args == NULL)
		return TRUE;
	    for (i = 0; i < type1->tt_argcount; ++i)
		if ((flags & ETYPE_ARG_UNKNOWN) == 0
			&& !equal_type(type1->tt_args[i], type2->tt_args[i],
									flags))
		    return FALSE;
	    return TRUE;
    }
    return TRUE;
}

/*
 * Find the common type of "type1" and "type2" and put it in "dest".
 * "type2" and "dest" may be the same.
 */
    void
common_type(type_T *type1, type_T *type2, type_T **dest, garray_T *type_gap)
{
    if (equal_type(type1, type2, 0))
    {
	*dest = type1;
	return;
    }

    // If either is VAR_UNKNOWN use the other type.  An empty list/dict has no
    // specific type.
    if (type1 == NULL || type1->tt_type == VAR_UNKNOWN)
    {
	*dest = type2;
	return;
    }
    if (type2 == NULL || type2->tt_type == VAR_UNKNOWN)
    {
	*dest = type1;
	return;
    }

    if (type1->tt_type == type2->tt_type)
    {
	if (type1->tt_type == VAR_LIST || type2->tt_type == VAR_DICT)
	{
	    type_T *common;

	    common_type(type1->tt_member, type2->tt_member, &common, type_gap);
	    if (type1->tt_type == VAR_LIST)
		*dest = get_list_type(common, type_gap);
	    else
		*dest = get_dict_type(common, type_gap);
	    return;
	}
	if (type1->tt_type == VAR_FUNC)
	{
	    type_T *common;

	    // When one of the types is t_func_unknown return the other one.
	    // Useful if a list or dict item is null_func.
	    if (type1 == &t_func_unknown)
	    {
		*dest = type2;
		return;
	    }
	    if (type2 == &t_func_unknown)
	    {
		*dest = type1;
		return;
	    }

	    common_type(type1->tt_member, type2->tt_member, &common, type_gap);
	    if (type1->tt_argcount == type2->tt_argcount
						    && type1->tt_argcount >= 0)
	    {
		int argcount = type1->tt_argcount;
		int i;

		*dest = alloc_func_type(common, argcount, type_gap);
		if (type1->tt_args != NULL && type2->tt_args != NULL)
		{
		    if (func_type_add_arg_types(*dest, argcount,
							     type_gap) == OK)
			for (i = 0; i < argcount; ++i)
			    common_type(type1->tt_args[i], type2->tt_args[i],
					       &(*dest)->tt_args[i], type_gap);
		}
	    }
	    else
		// Use -1 for "tt_argcount" to indicate an unknown number of
		// arguments.
		*dest = alloc_func_type(common, -1, type_gap);

	    // Use the minimum of min_argcount.
	    (*dest)->tt_min_argcount =
			type1->tt_min_argcount < type2->tt_min_argcount
			     ? type1->tt_min_argcount : type2->tt_min_argcount;
	    return;
	}
    }

    *dest = &t_any;
}

/*
 * Push an entry onto the type stack.  "type" used both for the current type
 * and the declared type.
 * Returns FAIL when out of memory.
 */
    int
push_type_stack(cctx_T *cctx, type_T *type)
{
    return push_type_stack2(cctx, type, type);
}

/*
 * Push an entry onto the type stack.  "type" is the current type, "decl_type"
 * is the declared type.
 * Returns FAIL when out of memory.
 */
    int
push_type_stack2(cctx_T *cctx, type_T *type, type_T *decl_type)
{
    garray_T	*stack = &cctx->ctx_type_stack;
    type2_T	*typep;

    if (GA_GROW_FAILS(stack, 1))
	return FAIL;
    typep = ((type2_T *)stack->ga_data) + stack->ga_len;
    typep->type_curr = type;
    typep->type_decl = decl_type;
    ++stack->ga_len;
    return OK;
}

/*
 * Set the type of the top of the stack to "type".
 */
    void
set_type_on_stack(cctx_T *cctx, type_T *type, int offset)
{
    garray_T	*stack = &cctx->ctx_type_stack;
    type2_T	*typep = ((type2_T *)stack->ga_data)
						  + stack->ga_len - 1 - offset;

    typep->type_curr = type;
    typep->type_decl = &t_any;
}

/*
 * Get the current type from the type stack.  If "offset" is zero the one at
 * the top,
 * if "offset" is one the type above that, etc.
 * Returns &t_unknown if there is no such stack entry.
 */
    type_T *
get_type_on_stack(cctx_T *cctx, int offset)
{
    garray_T	*stack = &cctx->ctx_type_stack;

    if (offset + 1 > stack->ga_len)
	return &t_unknown;
    return (((type2_T *)stack->ga_data) + stack->ga_len - offset - 1)
								   ->type_curr;
}

/*
 * Get the declared type from the type stack.  If "offset" is zero the one at
 * the top,
 * if "offset" is one the type above that, etc.
 * Returns &t_unknown if there is no such stack entry.
 */
    type_T *
get_decl_type_on_stack(cctx_T *cctx, int offset)
{
    garray_T	*stack = &cctx->ctx_type_stack;

    if (offset + 1 > stack->ga_len)
	return &t_unknown;
    return (((type2_T *)stack->ga_data) + stack->ga_len - offset - 1)
								   ->type_decl;
}

/*
 * Get the member type of a dict or list from the items on the stack of "cctx".
 * The declared type is stored in "decl_type".
 * For a list "skip" is 1, for a dict "skip" is 2, keys are skipped.
 * Returns &t_void for an empty list or dict.
 * Otherwise finds the common type of all items.
 */
    type_T *
get_member_type_from_stack(
	int	    count,
	int	    skip,
	cctx_T	    *cctx)
{
    garray_T	*stack = &cctx->ctx_type_stack;
    type2_T	*typep;
    garray_T    *type_gap = cctx->ctx_type_list;
    int		i;
    type_T	*result;
    type_T	*type;

    // Use "unknown" for an empty list or dict.
    if (count == 0)
	return &t_unknown;

    // Use the first value type for the list member type, then find the common
    // type from following items.
    typep = ((type2_T *)stack->ga_data) + stack->ga_len;
    result = (typep -(count * skip) + skip - 1)->type_curr;
    for (i = 1; i < count; ++i)
    {
	if (result == &t_any)
	    break;  // won't get more common
	type = (typep -((count - i) * skip) + skip - 1)->type_curr;
	common_type(type, result, &result, type_gap);
    }

    return result;
}

    char *
vartype_name(vartype_T type)
{
    switch (type)
    {
	case VAR_UNKNOWN: break;
	case VAR_ANY: return "any";
	case VAR_VOID: return "void";
	case VAR_SPECIAL: return "special";
	case VAR_BOOL: return "bool";
	case VAR_NUMBER: return "number";
	case VAR_FLOAT: return "float";
	case VAR_STRING: return "string";
	case VAR_BLOB: return "blob";
	case VAR_JOB: return "job";
	case VAR_CHANNEL: return "channel";
	case VAR_LIST: return "list";
	case VAR_DICT: return "dict";
	case VAR_INSTR: return "instr";
	case VAR_CLASS: return "class";
	case VAR_OBJECT: return "object";

	case VAR_FUNC:
	case VAR_PARTIAL: return "func";
    }
    return "unknown";
}

/*
 * Return the name of a type.
 * The result may be in allocated memory, in which case "tofree" is set.
 */
    char *
type_name(type_T *type, char **tofree)
{
    char *name;
    char *arg_free = NULL;

    *tofree = NULL;
    if (type == NULL)
	return "[unknown]";
    name = vartype_name(type->tt_type);

    if (type->tt_type == VAR_LIST || type->tt_type == VAR_DICT)
    {
	char *member_free;
	char *member_name = type_name(type->tt_member, &member_free);
	size_t len = STRLEN(name) + STRLEN(member_name) + 3;
	*tofree = alloc(len);
	if (*tofree != NULL)
	{
	    vim_snprintf(*tofree, len, "%s<%s>", name, member_name);
	    vim_free(member_free);
	    return *tofree;
	}
    }

    if (type->tt_type == VAR_OBJECT || type->tt_type == VAR_CLASS)
    {
	char_u *class_name = type->tt_class == NULL ? (char_u *)"Unknown"
				    : type->tt_class->class_name;
	size_t len = STRLEN(name) + STRLEN(class_name) + 3;
	*tofree = alloc(len);
	if (*tofree != NULL)
	{
	    vim_snprintf(*tofree, len, "%s<%s>", name, class_name);
	    return *tofree;
	}
    }

    if (type->tt_type == VAR_FUNC)
    {
	garray_T    ga;
	int	    i;
	int	    varargs = (type->tt_flags & TTFLAG_VARARGS) ? 1 : 0;

	ga_init2(&ga, 1, 100);
	if (ga_grow(&ga, 20) == FAIL)
	    goto failed;
	STRCPY(ga.ga_data, "func(");
	ga.ga_len += 5;

	for (i = 0; i < type->tt_argcount; ++i)
	{
	    char *arg_type;
	    int  len;

	    if (type->tt_args == NULL)
		arg_type = "[unknown]";
	    else
		arg_type = type_name(type->tt_args[i], &arg_free);
	    if (i > 0)
	    {
		STRCPY((char *)ga.ga_data + ga.ga_len, ", ");
		ga.ga_len += 2;
	    }
	    len = (int)STRLEN(arg_type);
	    if (ga_grow(&ga, len + 8) == FAIL)
		goto failed;
	    if (varargs && i == type->tt_argcount - 1)
		ga_concat(&ga, (char_u *)"...");
	    else if (i >= type->tt_min_argcount)
		*((char *)ga.ga_data + ga.ga_len++) = '?';
	    ga_concat(&ga, (char_u *)arg_type);
	    VIM_CLEAR(arg_free);
	}
	if (type->tt_argcount < 0)
	    // any number of arguments
	    ga_concat(&ga, (char_u *)"...");

	if (type->tt_member == &t_void)
	    STRCPY((char *)ga.ga_data + ga.ga_len, ")");
	else
	{
	    char *ret_free;
	    char *ret_name = type_name(type->tt_member, &ret_free);
	    int  len;

	    len = (int)STRLEN(ret_name) + 4;
	    if (ga_grow(&ga, len) == FAIL)
		goto failed;
	    STRCPY((char *)ga.ga_data + ga.ga_len, "): ");
	    STRCPY((char *)ga.ga_data + ga.ga_len + 3, ret_name);
	    vim_free(ret_free);
	}
	*tofree = ga.ga_data;
	return ga.ga_data;

failed:
	vim_free(arg_free);
	ga_clear(&ga);
	return "[unknown]";
    }

    return name;
}

/*
 * "typename(expr)" function
 */
    void
f_typename(typval_T *argvars, typval_T *rettv)
{
    garray_T	type_list;
    type_T	*type;
    char	*tofree;
    char	*name;

    rettv->v_type = VAR_STRING;
    ga_init2(&type_list, sizeof(type_T *), 10);
    type = typval2type(argvars, get_copyID(), &type_list, TVTT_DO_MEMBER);
    name = type_name(type, &tofree);
    if (tofree != NULL)
	rettv->vval.v_string = (char_u *)tofree;
    else
	rettv->vval.v_string = vim_strsave((char_u *)name);
    clear_type_list(&type_list);
}

#endif // FEAT_EVAL