get_lval(
    char_u	*name,
    typval_T	*rettv,
    lval_T	*lp,
    int		unlet,
    int		skip,
    int		flags,	    // GLV_ values
    int		fne_flags)  // flags for find_name_end()
{
    char_u	*p;
    char_u	*expr_start, *expr_end;
    int		cc;
    dictitem_T	*v;
    typval_T	var1;
    typval_T	var2;
    int		empty1 = FALSE;
    char_u	*key = NULL;
    int		len;
    hashtab_T	*ht = NULL;
    int		quiet = flags & GLV_QUIET;
    int		writing;
    int		vim9script = in_vim9script();

    // Clear everything in "lp".
    CLEAR_POINTER(lp);

    if (skip || (flags & GLV_COMPILING))
    {
	// When skipping or compiling just find the end of the name.
	lp->ll_name = name;
	lp->ll_name_end = find_name_end(name, NULL, NULL,
						      FNE_INCL_BR | fne_flags);
	return lp->ll_name_end;
    }

    // Cannot use "s:var" at the Vim9 script level.  "s: type" is OK.
    if (vim9script && at_script_level()
		  && name[0] == 's' && name[1] == ':' && !VIM_ISWHITE(name[2]))
    {
	semsg(_(e_cannot_use_s_colon_in_vim9_script_str), name);
	return NULL;
    }

    // Find the end of the name.
    p = find_name_end(name, &expr_start, &expr_end, fne_flags);
    lp->ll_name_end = p;
    if (expr_start != NULL)
    {
	// Don't expand the name when we already know there is an error.
	if (unlet && !VIM_ISWHITE(*p) && !ends_excmd(*p)
						    && *p != '[' && *p != '.')
	{
	    semsg(_(e_trailing_characters_str), p);
	    return NULL;
	}

	lp->ll_exp_name = make_expanded_name(name, expr_start, expr_end, p);
	if (lp->ll_exp_name == NULL)
	{
	    // Report an invalid expression in braces, unless the
	    // expression evaluation has been cancelled due to an
	    // aborting error, an interrupt, or an exception.
	    if (!aborting() && !quiet)
	    {
		emsg_severe = TRUE;
		semsg(_(e_invalid_argument_str), name);
		return NULL;
	    }
	}
	lp->ll_name = lp->ll_exp_name;
    }
    else
    {
	lp->ll_name = name;

	if (vim9script)
	{
	    // "a: type" is declaring variable "a" with a type, not "a:".
	    // However, "g:[key]" is indexing a dictionary.
	    if (p == name + 2 && p[-1] == ':' && *p != '[')
	    {
		--p;
		lp->ll_name_end = p;
	    }
	    if (*p == ':')
	    {
		char_u	    *tp = skipwhite(p + 1);

		if (tp == p + 1 && !quiet)
		{
		    semsg(_(e_white_space_required_after_str_str), ":", p);
		    return NULL;
		}

		if (!SCRIPT_ID_VALID(current_sctx.sc_sid))
		{
		    semsg(_(e_using_type_not_in_script_context_str), p);
		    return NULL;
		}

		// parse the type after the name
		lp->ll_type = parse_type(&tp,
			       &SCRIPT_ITEM(current_sctx.sc_sid)->sn_type_list,
			       !quiet);
		if (lp->ll_type == NULL && !quiet)
		    return NULL;
		lp->ll_name_end = tp;
	    }
	}
    }
    if (lp->ll_name == NULL)
	return p;

    if (*p == '.')
    {
	imported_T *import = find_imported(lp->ll_name, p - lp->ll_name, TRUE);

	if (import != NULL)
	{
	    ufunc_T *ufunc;
	    type_T *type;

	    lp->ll_sid = import->imp_sid;
	    lp->ll_name = skipwhite(p + 1);
	    p = find_name_end(lp->ll_name, NULL, NULL, fne_flags);
	    lp->ll_name_end = p;

	    // check the item is exported
	    cc = *p;
	    *p = NUL;
	    if (find_exported(import->imp_sid, lp->ll_name, &ufunc, &type,
						       NULL, NULL, TRUE) == -1)
	    {
		*p = cc;
		return NULL;
	    }
	    *p = cc;
	}
    }

    // Without [idx] or .key we are done.
    if ((*p != '[' && *p != '.'))
	return p;

    if (vim9script && lval_root != NULL)
    {
	// using local variable
	lp->ll_tv = lval_root;
	v = NULL;
    }
    else
    {
	cc = *p;
	*p = NUL;
	// When we would write to the variable pass &ht and prevent autoload.
	writing = !(flags & GLV_READ_ONLY);
	v = find_var(lp->ll_name, writing ? &ht : NULL,
					 (flags & GLV_NO_AUTOLOAD) || writing);
	if (v == NULL && !quiet)
	    semsg(_(e_undefined_variable_str), lp->ll_name);
	*p = cc;
	if (v == NULL)
	    return NULL;
	lp->ll_tv = &v->di_tv;
    }

    if (vim9script && (flags & GLV_NO_DECL) == 0)
    {
	if (!quiet)
	    semsg(_(e_variable_already_declared), lp->ll_name);
	return NULL;
    }

    /*
     * Loop until no more [idx] or .key is following.
     */
    var1.v_type = VAR_UNKNOWN;
    var2.v_type = VAR_UNKNOWN;
    while (*p == '[' || (*p == '.' && p[1] != '=' && p[1] != '.'))
    {
	if (*p == '.' && lp->ll_tv->v_type != VAR_DICT)
	{
	    if (!quiet)
		semsg(_(e_dot_can_only_be_used_on_dictionary_str), name);
	    return NULL;
	}
	if (lp->ll_tv->v_type != VAR_LIST
		&& lp->ll_tv->v_type != VAR_DICT
		&& lp->ll_tv->v_type != VAR_BLOB)
	{
	    if (!quiet)
		emsg(_(e_can_only_index_list_dictionary_or_blob));
	    return NULL;
	}

	// a NULL list/blob works like an empty list/blob, allocate one now.
	if (lp->ll_tv->v_type == VAR_LIST && lp->ll_tv->vval.v_list == NULL)
	    rettv_list_alloc(lp->ll_tv);
	else if (lp->ll_tv->v_type == VAR_BLOB
					     && lp->ll_tv->vval.v_blob == NULL)
	    rettv_blob_alloc(lp->ll_tv);

	if (lp->ll_range)
	{
	    if (!quiet)
		emsg(_(e_slice_must_come_last));
	    return NULL;
	}

	if (vim9script && lp->ll_valtype == NULL
		&& v != NULL
		&& lp->ll_tv == &v->di_tv
		&& ht != NULL && ht == get_script_local_ht())
	{
	    svar_T  *sv = find_typval_in_script(lp->ll_tv, 0, TRUE);

	    // Vim9 script local variable: get the type
	    if (sv != NULL)
		lp->ll_valtype = sv->sv_type;
	}

	len = -1;
	if (*p == '.')
	{
	    key = p + 1;
	    for (len = 0; ASCII_ISALNUM(key[len]) || key[len] == '_'; ++len)
		;
	    if (len == 0)
	    {
		if (!quiet)
		    emsg(_(e_cannot_use_empty_key_for_dictionary));
		return NULL;
	    }
	    p = key + len;
	}
	else
	{
	    // Get the index [expr] or the first index [expr: ].
	    p = skipwhite(p + 1);
	    if (*p == ':')
		empty1 = TRUE;
	    else
	    {
		empty1 = FALSE;
		if (eval1(&p, &var1, &EVALARG_EVALUATE) == FAIL)  // recursive!
		    return NULL;
		if (tv_get_string_chk(&var1) == NULL)
		{
		    // not a number or string
		    clear_tv(&var1);
		    return NULL;
		}
		p = skipwhite(p);
	    }

	    // Optionally get the second index [ :expr].
	    if (*p == ':')
	    {
		if (lp->ll_tv->v_type == VAR_DICT)
		{
		    if (!quiet)
			emsg(_(e_cannot_slice_dictionary));
		    clear_tv(&var1);
		    return NULL;
		}
		if (rettv != NULL
			&& !(rettv->v_type == VAR_LIST
						 && rettv->vval.v_list != NULL)
			&& !(rettv->v_type == VAR_BLOB
						&& rettv->vval.v_blob != NULL))
		{
		    if (!quiet)
			emsg(_(e_slice_requires_list_or_blob_value));
		    clear_tv(&var1);
		    return NULL;
		}
		p = skipwhite(p + 1);
		if (*p == ']')
		    lp->ll_empty2 = TRUE;
		else
		{
		    lp->ll_empty2 = FALSE;
		    // recursive!
		    if (eval1(&p, &var2, &EVALARG_EVALUATE) == FAIL)
		    {
			clear_tv(&var1);
			return NULL;
		    }
		    if (tv_get_string_chk(&var2) == NULL)
		    {
			// not a number or string
			clear_tv(&var1);
			clear_tv(&var2);
			return NULL;
		    }
		}
		lp->ll_range = TRUE;
	    }
	    else
		lp->ll_range = FALSE;

	    if (*p != ']')
	    {
		if (!quiet)
		    emsg(_(e_missing_closing_square_brace));
		clear_tv(&var1);
		clear_tv(&var2);
		return NULL;
	    }

	    // Skip to past ']'.
	    ++p;
	}

	if (lp->ll_tv->v_type == VAR_DICT)
	{
	    if (len == -1)
	    {
		// "[key]": get key from "var1"
		key = tv_get_string_chk(&var1);	// is number or string
		if (key == NULL)
		{
		    clear_tv(&var1);
		    return NULL;
		}
	    }
	    lp->ll_list = NULL;

	    // a NULL dict is equivalent with an empty dict
	    if (lp->ll_tv->vval.v_dict == NULL)
	    {
		lp->ll_tv->vval.v_dict = dict_alloc();
		if (lp->ll_tv->vval.v_dict == NULL)
		{
		    clear_tv(&var1);
		    return NULL;
		}
		++lp->ll_tv->vval.v_dict->dv_refcount;
	    }
	    lp->ll_dict = lp->ll_tv->vval.v_dict;

	    lp->ll_di = dict_find(lp->ll_dict, key, len);

	    // When assigning to a scope dictionary check that a function and
	    // variable name is valid (only variable name unless it is l: or
	    // g: dictionary). Disallow overwriting a builtin function.
	    if (rettv != NULL && lp->ll_dict->dv_scope != 0)
	    {
		int prevval;
		int wrong;

		if (len != -1)
		{
		    prevval = key[len];
		    key[len] = NUL;
		}
		else
		    prevval = 0; // avoid compiler warning
		wrong = (lp->ll_dict->dv_scope == VAR_DEF_SCOPE
			       && rettv->v_type == VAR_FUNC
			       && var_wrong_func_name(key, lp->ll_di == NULL))
			|| !valid_varname(key, -1, TRUE);
		if (len != -1)
		    key[len] = prevval;
		if (wrong)
		{
		    clear_tv(&var1);
		    return NULL;
		}
	    }

	    if (lp->ll_valtype != NULL)
		// use the type of the member
		lp->ll_valtype = lp->ll_valtype->tt_member;

	    if (lp->ll_di == NULL)
	    {
		// Can't add "v:" or "a:" variable.
		if (lp->ll_dict == get_vimvar_dict()
			 || &lp->ll_dict->dv_hashtab == get_funccal_args_ht())
		{
		    semsg(_(e_illegal_variable_name_str), name);
		    clear_tv(&var1);
		    return NULL;
		}

		// Key does not exist in dict: may need to add it.
		if (*p == '[' || *p == '.' || unlet)
		{
		    if (!quiet)
			semsg(_(e_key_not_present_in_dictionary), key);
		    clear_tv(&var1);
		    return NULL;
		}
		if (len == -1)
		    lp->ll_newkey = vim_strsave(key);
		else
		    lp->ll_newkey = vim_strnsave(key, len);
		clear_tv(&var1);
		if (lp->ll_newkey == NULL)
		    p = NULL;
		break;
	    }
	    // existing variable, need to check if it can be changed
	    else if ((flags & GLV_READ_ONLY) == 0
			&& (var_check_ro(lp->ll_di->di_flags, name, FALSE)
			  || var_check_lock(lp->ll_di->di_flags, name, FALSE)))
	    {
		clear_tv(&var1);
		return NULL;
	    }

	    clear_tv(&var1);
	    lp->ll_tv = &lp->ll_di->di_tv;
	}
	else if (lp->ll_tv->v_type == VAR_BLOB)
	{
	    long bloblen = blob_len(lp->ll_tv->vval.v_blob);

	    /*
	     * Get the number and item for the only or first index of the List.
	     */
	    if (empty1)
		lp->ll_n1 = 0;
	    else
		// is number or string
		lp->ll_n1 = (long)tv_get_number(&var1);
	    clear_tv(&var1);

	    if (check_blob_index(bloblen, lp->ll_n1, quiet) == FAIL)
	    {
		clear_tv(&var2);
		return NULL;
	    }
	    if (lp->ll_range && !lp->ll_empty2)
	    {
		lp->ll_n2 = (long)tv_get_number(&var2);
		clear_tv(&var2);
		if (check_blob_range(bloblen, lp->ll_n1, lp->ll_n2, quiet)
								       == FAIL)
		    return NULL;
	    }
	    lp->ll_blob = lp->ll_tv->vval.v_blob;
	    lp->ll_tv = NULL;
	    break;
	}
	else
	{
	    /*
	     * Get the number and item for the only or first index of the List.
	     */
	    if (empty1)
		lp->ll_n1 = 0;
	    else
		// is number or string
		lp->ll_n1 = (long)tv_get_number(&var1);
	    clear_tv(&var1);

	    lp->ll_dict = NULL;
	    lp->ll_list = lp->ll_tv->vval.v_list;
	    lp->ll_li = check_range_index_one(lp->ll_list, &lp->ll_n1,
				     (flags & GLV_ASSIGN_WITH_OP) == 0, quiet);
	    if (lp->ll_li == NULL)
	    {
		clear_tv(&var2);
		return NULL;
	    }

	    if (lp->ll_valtype != NULL)
		// use the type of the member
		lp->ll_valtype = lp->ll_valtype->tt_member;

	    /*
	     * May need to find the item or absolute index for the second
	     * index of a range.
	     * When no index given: "lp->ll_empty2" is TRUE.
	     * Otherwise "lp->ll_n2" is set to the second index.
	     */
	    if (lp->ll_range && !lp->ll_empty2)
	    {
		lp->ll_n2 = (long)tv_get_number(&var2);
						    // is number or string
		clear_tv(&var2);
		if (check_range_index_two(lp->ll_list,
					    &lp->ll_n1, lp->ll_li,
					    &lp->ll_n2, quiet) == FAIL)
		    return NULL;
	    }

	    lp->ll_tv = &lp->ll_li->li_tv;
	}
    }

    clear_tv(&var1);
    lp->ll_name_end = p;
    return p;
}