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forked from aniani/vim

patch 8.2.3215: Vim9: argument types are not checked at compile time

Problem:    Vim9: argument types are not checked at compile time.
Solution:   Add several more type checks. Sort the argument lists.
            (Yegappan Lakshmanan, closes #8626)
This commit is contained in:
Yegappan Lakshmanan
2021-07-24 21:33:26 +02:00
committed by Bram Moolenaar
parent 7d60384a00
commit 5bca906b30
8 changed files with 233 additions and 112 deletions

View File

@@ -644,83 +644,91 @@ arg_cursor1(type_T *type, argcontext_T *context)
/*
* Lists of functions that check the argument types of a builtin function.
*/
static argcheck_T arg1_string[] = {arg_string};
static argcheck_T arg1_number[] = {arg_number};
static argcheck_T arg1_bool[] = {arg_bool};
static argcheck_T arg1_list_any[] = {arg_list_any};
static argcheck_T arg1_dict_any[] = {arg_dict_any};
static argcheck_T arg1_job[] = {arg_job};
static argcheck_T arg1_buffer[] = {arg_buffer};
static argcheck_T arg1_lnum[] = {arg_lnum};
static argcheck_T arg1_list_number[] = {arg_list_number};
static argcheck_T arg1_list_string[] = {arg_list_string};
static argcheck_T arg1_buffer_or_dict_any[] = {arg_buffer_or_dict_any};
static argcheck_T arg1_chan_or_job[] = {arg_chan_or_job};
static argcheck_T arg1_dict_any[] = {arg_dict_any};
static argcheck_T arg1_dict_or_string[] = {arg_dict_any_or_string};
static argcheck_T arg1_float_or_nr[] = {arg_float_or_nr};
static argcheck_T arg1_string_or_nr[] = {arg_string_or_nr};
static argcheck_T arg1_string_or_list_any[] = {arg_string_or_list_any};
static argcheck_T arg1_string_or_list_string[] = {arg_string_or_list_string};
static argcheck_T arg1_job[] = {arg_job};
static argcheck_T arg1_list_any[] = {arg_list_any};
static argcheck_T arg1_list_number[] = {arg_list_number};
static argcheck_T arg1_list_or_blob[] = {arg_list_or_blob};
static argcheck_T arg1_list_or_dict[] = {arg_list_or_dict};
static argcheck_T arg1_chan_or_job[] = {arg_chan_or_job};
static argcheck_T arg1_dict_or_string[] = {arg_dict_any_or_string};
static argcheck_T arg1_buffer_or_dict_any[] = {arg_buffer_or_dict_any};
static argcheck_T arg2_float_or_nr[] = {arg_float_or_nr, arg_float_or_nr};
static argcheck_T arg2_number[] = {arg_number, arg_number};
static argcheck_T arg2_string[] = {arg_string, arg_string};
static argcheck_T arg2_string_number[] = {arg_string, arg_number};
static argcheck_T arg2_string_dict[] = {arg_string, arg_dict_any};
static argcheck_T arg2_string_list_nr[] = {arg_string, arg_list_number};
static argcheck_T arg2_string_bool[] = {arg_string, arg_bool};
static argcheck_T arg2_string_or_list_dict[] = {arg_string_or_list_any, arg_dict_any};
static argcheck_T arg2_string_string_or_number[] = {arg_string, arg_string_or_nr};
static argcheck_T arg2_string_chan_or_job[] = {arg_string, arg_chan_or_job};
static argcheck_T arg2_list_number[] = {arg_list_number, arg_list_number};
static argcheck_T arg2_list_number_bool[] = {arg_list_number, arg_bool};
static argcheck_T arg2_list_any_string[] = {arg_list_any, arg_string};
static argcheck_T arg2_list_any_number[] = {arg_list_any, arg_number};
static argcheck_T arg2_number_string[] = {arg_number, arg_string};
static argcheck_T arg2_number_bool[] = {arg_number, arg_bool};
static argcheck_T arg2_number_list[] = {arg_number, arg_list_any};
static argcheck_T arg2_number_dict_any[] = {arg_number, arg_dict_any};
static argcheck_T arg2_number_string_or_list[] = {arg_number, arg_string_or_list_any};
static argcheck_T arg2_dict_string[] = {arg_dict_any, arg_string};
static argcheck_T arg2_dict_any_string_or_nr[] = {arg_dict_any, arg_string_or_nr};
static argcheck_T arg2_job_dict[] = {arg_job, arg_dict_any};
static argcheck_T arg2_job_string_or_number[] = {arg_job, arg_string_or_nr};
static argcheck_T arg2_listblob_item[] = {arg_list_or_blob, arg_item_of_prev};
static argcheck_T arg2_str_or_nr_or_list_dict[] = {arg_str_or_nr_or_list, arg_dict_any};
static argcheck_T arg2_lnum[] = {arg_lnum, arg_lnum};
static argcheck_T arg2_lnum_number[] = {arg_lnum, arg_number};
static argcheck_T arg1_list_string[] = {arg_list_string};
static argcheck_T arg1_lnum[] = {arg_lnum};
static argcheck_T arg1_number[] = {arg_number};
static argcheck_T arg1_string[] = {arg_string};
static argcheck_T arg1_string_or_list_any[] = {arg_string_or_list_any};
static argcheck_T arg1_string_or_list_string[] = {arg_string_or_list_string};
static argcheck_T arg1_string_or_nr[] = {arg_string_or_nr};
static argcheck_T arg2_any_buffer[] = {NULL, arg_buffer};
static argcheck_T arg2_buffer_any[] = {arg_buffer, NULL};
static argcheck_T arg2_buffer_bool[] = {arg_buffer, arg_bool};
static argcheck_T arg2_buffer_list_any[] = {arg_buffer, arg_list_any};
static argcheck_T arg2_buffer_lnum[] = {arg_buffer, arg_lnum};
static argcheck_T arg2_buffer_number[] = {arg_buffer, arg_number};
static argcheck_T arg2_buffer_string[] = {arg_buffer, arg_string};
static argcheck_T arg2_chan_or_job_dict[] = {arg_chan_or_job, arg_dict_any};
static argcheck_T arg2_chan_or_job_string[] = {arg_chan_or_job, arg_string};
static argcheck_T arg2_buffer_string[] = {arg_buffer, arg_string};
static argcheck_T arg2_buffer_number[] = {arg_buffer, arg_number};
static argcheck_T arg2_buffer_bool[] = {arg_buffer, arg_bool};
static argcheck_T arg2_buffer_lnum[] = {arg_buffer, arg_lnum};
static argcheck_T arg2_buffer_list_any[] = {arg_buffer, arg_list_any};
static argcheck_T arg2_buffer_any[] = {arg_buffer, NULL};
static argcheck_T arg3_string[] = {arg_string, arg_string, arg_string};
static argcheck_T arg3_number[] = {arg_number, arg_number, arg_number};
static argcheck_T arg3_number_number_dict[] = {arg_number, arg_number, arg_dict_any};
static argcheck_T arg3_number_string_string[] = {arg_number, arg_string, arg_string};
static argcheck_T arg3_number_string_any[] = {arg_number, arg_string, NULL};
static argcheck_T arg3_number_string_buffer[] = {arg_number, arg_string, arg_buffer};
static argcheck_T arg3_number_any_dict[] = {arg_number, NULL, arg_dict_any};
static argcheck_T arg3_string_nr_bool[] = {arg_string, arg_number, arg_bool};
static argcheck_T arg3_string_string_nr[] = {arg_string, arg_string, arg_number};
static argcheck_T arg3_string_string_dict[] = {arg_string, arg_string, arg_dict_any};
static argcheck_T arg3_string_string_bool[] = {arg_string, arg_string, arg_bool};
static argcheck_T arg3_string_bool_bool[] = {arg_string, arg_bool, arg_bool};
static argcheck_T arg3_string_bool_dict[] = {arg_string, arg_bool, arg_dict_any};
static argcheck_T arg3_list_string_dict[] = {arg_list_any, arg_string, arg_dict_any};
static argcheck_T arg3_dict_number_number[] = {arg_dict_any, arg_number, arg_number};
static argcheck_T arg3_lnum_number_bool[] = {arg_lnum, arg_number, arg_bool};
static argcheck_T arg2_dict_any_string_or_nr[] = {arg_dict_any, arg_string_or_nr};
static argcheck_T arg2_dict_string[] = {arg_dict_any, arg_string};
static argcheck_T arg2_float_or_nr[] = {arg_float_or_nr, arg_float_or_nr};
static argcheck_T arg2_job_dict[] = {arg_job, arg_dict_any};
static argcheck_T arg2_job_string_or_number[] = {arg_job, arg_string_or_nr};
static argcheck_T arg2_list_any_number[] = {arg_list_any, arg_number};
static argcheck_T arg2_list_any_string[] = {arg_list_any, arg_string};
static argcheck_T arg2_list_number[] = {arg_list_number, arg_list_number};
static argcheck_T arg2_list_number_bool[] = {arg_list_number, arg_bool};
static argcheck_T arg2_listblob_item[] = {arg_list_or_blob, arg_item_of_prev};
static argcheck_T arg2_lnum[] = {arg_lnum, arg_lnum};
static argcheck_T arg2_lnum_number[] = {arg_lnum, arg_number};
static argcheck_T arg2_number[] = {arg_number, arg_number};
static argcheck_T arg2_number_bool[] = {arg_number, arg_bool};
static argcheck_T arg2_number_dict_any[] = {arg_number, arg_dict_any};
static argcheck_T arg2_number_list[] = {arg_number, arg_list_any};
static argcheck_T arg2_number_string[] = {arg_number, arg_string};
static argcheck_T arg2_number_string_or_list[] = {arg_number, arg_string_or_list_any};
static argcheck_T arg2_str_or_nr_or_list_dict[] = {arg_str_or_nr_or_list, arg_dict_any};
static argcheck_T arg2_string[] = {arg_string, arg_string};
static argcheck_T arg2_string_any[] = {arg_string, NULL};
static argcheck_T arg2_string_bool[] = {arg_string, arg_bool};
static argcheck_T arg2_string_chan_or_job[] = {arg_string, arg_chan_or_job};
static argcheck_T arg2_string_dict[] = {arg_string, arg_dict_any};
static argcheck_T arg2_string_list_number[] = {arg_string, arg_list_number};
static argcheck_T arg2_string_number[] = {arg_string, arg_number};
static argcheck_T arg2_string_or_list_dict[] = {arg_string_or_list_any, arg_dict_any};
static argcheck_T arg2_string_string_or_number[] = {arg_string, arg_string_or_nr};
static argcheck_T arg3_any_list_dict[] = {NULL, arg_list_any, arg_dict_any};
static argcheck_T arg3_buffer_lnum_lnum[] = {arg_buffer, arg_lnum, arg_lnum};
static argcheck_T arg3_buffer_number_number[] = {arg_buffer, arg_number, arg_number};
static argcheck_T arg3_buffer_string_dict[] = {arg_buffer, arg_string, arg_dict_any};
static argcheck_T arg3_buffer_string_any[] = {arg_buffer, arg_string, NULL};
static argcheck_T arg3_buffer_string_dict[] = {arg_buffer, arg_string, arg_dict_any};
static argcheck_T arg3_dict_number_number[] = {arg_dict_any, arg_number, arg_number};
static argcheck_T arg3_list_string_dict[] = {arg_list_any, arg_string, arg_dict_any};
static argcheck_T arg3_lnum_number_bool[] = {arg_lnum, arg_number, arg_bool};
static argcheck_T arg3_number[] = {arg_number, arg_number, arg_number};
static argcheck_T arg3_number_any_dict[] = {arg_number, NULL, arg_dict_any};
static argcheck_T arg3_number_number_dict[] = {arg_number, arg_number, arg_dict_any};
static argcheck_T arg3_number_string_any[] = {arg_number, arg_string, NULL};
static argcheck_T arg3_number_string_buffer[] = {arg_number, arg_string, arg_buffer};
static argcheck_T arg3_number_string_string[] = {arg_number, arg_string, arg_string};
static argcheck_T arg3_string[] = {arg_string, arg_string, arg_string};
static argcheck_T arg3_string_any_dict[] = {arg_string, NULL, arg_dict_any};
static argcheck_T arg3_string_bool_bool[] = {arg_string, arg_bool, arg_bool};
static argcheck_T arg3_string_bool_dict[] = {arg_string, arg_bool, arg_dict_any};
static argcheck_T arg3_string_number_bool[] = {arg_string, arg_number, arg_bool};
static argcheck_T arg3_string_number_number[] = {arg_string, arg_number, arg_number};
static argcheck_T arg3_string_string_bool[] = {arg_string, arg_string, arg_bool};
static argcheck_T arg3_string_string_dict[] = {arg_string, arg_string, arg_dict_any};
static argcheck_T arg3_string_string_nr[] = {arg_string, arg_string, arg_number};
static argcheck_T arg4_list_number_number_number[] = {arg_list_string, arg_number, arg_number, arg_number};
static argcheck_T arg4_number_number_string_any[] = {arg_number, arg_number, arg_string, NULL};
static argcheck_T arg4_string_string_any_string[] = {arg_string, arg_string, NULL, arg_string};
static argcheck_T arg4_string_string_number_string[] = {arg_string, arg_string, arg_number, arg_string};
static argcheck_T arg5_number[] = {arg_number, arg_number, arg_number, arg_number, arg_number};
/* Function specific argument types (not covered by the above) */
static argcheck_T arg4_browse[] = {arg_bool, arg_string, arg_string, arg_string};
static argcheck_T arg23_chanexpr[] = {arg_chan_or_job, NULL, arg_dict_any};
static argcheck_T arg23_chanraw[] = {arg_chan_or_job, arg_string_or_blob, arg_dict_any};
@@ -734,8 +742,9 @@ static argcheck_T arg14_glob[] = {arg_string, arg_bool, arg_bool, arg_bool};
static argcheck_T arg25_globpath[] = {arg_string, arg_string, arg_bool, arg_bool, arg_bool};
static argcheck_T arg24_index[] = {arg_list_or_blob, arg_item_of_prev, arg_number, arg_bool};
static argcheck_T arg23_insert[] = {arg_list_or_blob, arg_item_of_prev, arg_number};
static argcheck_T arg2_mapfilter[] = {arg_list_or_dict_or_blob, NULL};
static argcheck_T arg3_libcall[] = {arg_string, arg_string, arg_string_or_nr};
static argcheck_T arg14_maparg[] = {arg_string, arg_string, arg_bool, arg_bool};
static argcheck_T arg2_mapfilter[] = {arg_list_or_dict_or_blob, NULL};
static argcheck_T arg25_matchadd[] = {arg_string, arg_string, arg_number, arg_number, arg_dict_any};
static argcheck_T arg25_matchaddpos[] = {arg_string, arg_list_any, arg_number, arg_number, arg_dict_any};
static argcheck_T arg23_reduce[] = {arg_list_or_blob, NULL, NULL};
@@ -1138,7 +1147,7 @@ static funcentry_T global_functions[] =
ret_number, f_byteidx},
{"byteidxcomp", 2, 2, FEARG_1, arg2_string_number,
ret_number, f_byteidxcomp},
{"call", 2, 3, FEARG_1, NULL,
{"call", 2, 3, FEARG_1, arg3_any_list_dict,
ret_any, f_call},
{"ceil", 1, 1, FEARG_1, arg1_float_or_nr,
ret_float, FLOAT_FUNC(f_ceil)},
@@ -1186,7 +1195,7 @@ static funcentry_T global_functions[] =
ret_number, f_charclass},
{"charcol", 1, 1, FEARG_1, arg1_string_or_list_any,
ret_number, f_charcol},
{"charidx", 2, 3, FEARG_1, arg3_string_nr_bool,
{"charidx", 2, 3, FEARG_1, arg3_string_number_bool,
ret_number, f_charidx},
{"chdir", 1, 1, FEARG_1, arg1_string,
ret_string, f_chdir},
@@ -1310,9 +1319,9 @@ static funcentry_T global_functions[] =
ret_void, f_foreground},
{"fullcommand", 1, 1, FEARG_1, arg1_string,
ret_string, f_fullcommand},
{"funcref", 1, 3, FEARG_1, NULL,
{"funcref", 1, 3, FEARG_1, arg3_any_list_dict,
ret_func_any, f_funcref},
{"function", 1, 3, FEARG_1, NULL,
{"function", 1, 3, FEARG_1, arg3_any_list_dict,
ret_f_function, f_function},
{"garbagecollect", 0, 1, 0, arg1_bool,
ret_void, f_garbagecollect},
@@ -1508,9 +1517,9 @@ static funcentry_T global_functions[] =
ret_number, f_last_buffer_nr},
{"len", 1, 1, FEARG_1, NULL,
ret_number, f_len},
{"libcall", 3, 3, FEARG_3, NULL,
{"libcall", 3, 3, FEARG_3, arg3_libcall,
ret_string, f_libcall},
{"libcallnr", 3, 3, FEARG_3, NULL,
{"libcallnr", 3, 3, FEARG_3, arg3_libcall,
ret_number, f_libcallnr},
{"line", 1, 2, FEARG_1, arg2_string_number,
ret_number, f_line},
@@ -1520,7 +1529,7 @@ static funcentry_T global_functions[] =
ret_number, f_lispindent},
{"list2str", 1, 2, FEARG_1, arg2_list_number_bool,
ret_string, f_list2str},
{"listener_add", 1, 2, FEARG_2, NULL,
{"listener_add", 1, 2, FEARG_2, arg2_any_buffer,
ret_number, f_listener_add},
{"listener_flush", 0, 1, FEARG_1, arg1_buffer,
ret_void, f_listener_flush},
@@ -1722,9 +1731,9 @@ static funcentry_T global_functions[] =
ret_list_number, f_range},
{"readblob", 1, 1, FEARG_1, arg1_string,
ret_blob, f_readblob},
{"readdir", 1, 3, FEARG_1, NULL,
{"readdir", 1, 3, FEARG_1, arg3_string_any_dict,
ret_list_string, f_readdir},
{"readdirex", 1, 3, FEARG_1, NULL,
{"readdirex", 1, 3, FEARG_1, arg3_string_any_dict,
ret_list_dict_any, f_readdirex},
{"readfile", 1, 3, FEARG_1, arg3_string_string_nr,
ret_list_string, f_readfile},
@@ -1808,7 +1817,7 @@ static funcentry_T global_functions[] =
ret_void, f_setbufvar},
{"setcellwidths", 1, 1, FEARG_1, arg1_list_any,
ret_void, f_setcellwidths},
{"setcharpos", 2, 2, FEARG_2, arg2_string_list_nr,
{"setcharpos", 2, 2, FEARG_2, arg2_string_list_number,
ret_number_bool, f_setcharpos},
{"setcharsearch", 1, 1, FEARG_1, arg1_dict_any,
ret_void, f_setcharsearch},
@@ -1830,7 +1839,7 @@ static funcentry_T global_functions[] =
ret_number_bool, f_setloclist},
{"setmatches", 1, 2, FEARG_1, arg2_list_any_number,
ret_number_bool, f_setmatches},
{"setpos", 2, 2, FEARG_2, arg2_string_list_nr,
{"setpos", 2, 2, FEARG_2, arg2_string_list_number,
ret_number_bool, f_setpos},
{"setqflist", 1, 3, FEARG_1, arg13_setqflist,
ret_number_bool, f_setqflist},
@@ -1886,9 +1895,9 @@ static funcentry_T global_functions[] =
ret_first_arg, f_sort},
{"sound_clear", 0, 0, 0, NULL,
ret_void, SOUND_FUNC(f_sound_clear)},
{"sound_playevent", 1, 2, FEARG_1, NULL,
{"sound_playevent", 1, 2, FEARG_1, arg2_string_any,
ret_number, SOUND_FUNC(f_sound_playevent)},
{"sound_playfile", 1, 2, FEARG_1, NULL,
{"sound_playfile", 1, 2, FEARG_1, arg2_string_any,
ret_number, SOUND_FUNC(f_sound_playfile)},
{"sound_stop", 1, 1, FEARG_1, arg1_number,
ret_void, SOUND_FUNC(f_sound_stop)},
@@ -1896,7 +1905,7 @@ static funcentry_T global_functions[] =
ret_string, f_soundfold},
{"spellbadword", 0, 1, FEARG_1, arg1_string,
ret_list_string, f_spellbadword},
{"spellsuggest", 1, 3, FEARG_1, arg3_string_nr_bool,
{"spellsuggest", 1, 3, FEARG_1, arg3_string_number_bool,
ret_list_string, f_spellsuggest},
{"split", 1, 3, FEARG_1, arg3_string_string_bool,
ret_list_string, f_split},
@@ -1910,7 +1919,7 @@ static funcentry_T global_functions[] =
ret_float, FLOAT_FUNC(f_str2float)},
{"str2list", 1, 2, FEARG_1, arg2_string_bool,
ret_list_number, f_str2list},
{"str2nr", 1, 3, FEARG_1, arg3_string_nr_bool,
{"str2nr", 1, 3, FEARG_1, arg3_string_number_bool,
ret_number, f_str2nr},
{"strcharlen", 1, 1, FEARG_1, arg1_string_or_nr,
ret_number, f_strcharlen},
@@ -1954,7 +1963,7 @@ static funcentry_T global_functions[] =
ret_number, f_strwidth},
{"submatch", 1, 2, FEARG_1, arg2_number_bool,
ret_string, f_submatch},
{"substitute", 4, 4, FEARG_1, NULL,
{"substitute", 4, 4, FEARG_1, arg4_string_string_any_string,
ret_string, f_substitute},
{"swapinfo", 1, 1, FEARG_1, arg1_string,
ret_dict_any, f_swapinfo},
@@ -2064,7 +2073,7 @@ static funcentry_T global_functions[] =
ret_void, f_test_garbagecollect_soon},
{"test_getvalue", 1, 1, FEARG_1, arg1_string,
ret_number, f_test_getvalue},
{"test_gui_drop_files", 4, 4, 0, NULL,
{"test_gui_drop_files", 4, 4, 0, arg4_list_number_number_number,
ret_void, f_test_gui_drop_files},
{"test_gui_mouse_event", 5, 5, 0, arg5_number,
ret_void, f_test_gui_mouse_event},
@@ -2092,7 +2101,7 @@ static funcentry_T global_functions[] =
ret_void, f_test_override},
{"test_refcount", 1, 1, FEARG_1, NULL,
ret_number, f_test_refcount},
{"test_scrollbar", 3, 3, FEARG_2, NULL,
{"test_scrollbar", 3, 3, FEARG_2, arg3_string_number_number,
ret_void,
#ifdef FEAT_GUI
f_test_scrollbar
@@ -2682,6 +2691,11 @@ f_call(typval_T *argvars, typval_T *rettv)
partial_T *partial = NULL;
dict_T *selfdict = NULL;
if (in_vim9script()
&& (check_for_list_arg(argvars, 1) == FAIL
|| check_for_opt_dict_arg(argvars, 2) == FAIL))
return;
if (argvars[1].v_type != VAR_LIST)
{
emsg(_(e_listreq));
@@ -3734,6 +3748,12 @@ common_function(typval_T *argvars, typval_T *rettv, int is_funcref)
char_u *trans_name = NULL;
int is_global = FALSE;
if (in_vim9script()
&& (check_for_opt_list_arg(argvars, 1) == FAIL
|| (argvars[1].v_type != VAR_UNKNOWN
&& check_for_opt_dict_arg(argvars, 2) == FAIL)))
return;
if (argvars[0].v_type == VAR_FUNC)
{
// function(MyFunc, [arg], dict)
@@ -6417,6 +6437,12 @@ libcall_common(typval_T *argvars UNUSED, typval_T *rettv, int type)
if (check_restricted() || check_secure())
return;
if (in_vim9script()
&& (check_for_string_arg(argvars, 0) == FAIL
|| check_for_string_arg(argvars, 1) == FAIL
|| check_for_string_or_number_arg(argvars, 2) == FAIL))
return;
#ifdef FEAT_LIBCALL
// The first two args must be strings, otherwise it's meaningless
if (argvars[0].v_type == VAR_STRING && argvars[1].v_type == VAR_STRING)
@@ -9177,12 +9203,21 @@ f_substitute(typval_T *argvars, typval_T *rettv)
char_u patbuf[NUMBUFLEN];
char_u subbuf[NUMBUFLEN];
char_u flagsbuf[NUMBUFLEN];
char_u *str = tv_get_string_chk(&argvars[0]);
char_u *pat = tv_get_string_buf_chk(&argvars[1], patbuf);
char_u *str;
char_u *pat;
char_u *sub = NULL;
typval_T *expr = NULL;
char_u *flg = tv_get_string_buf_chk(&argvars[3], flagsbuf);
char_u *flg;
if (in_vim9script()
&& (check_for_string_arg(argvars, 0) == FAIL
|| check_for_string_arg(argvars, 1) == FAIL
|| check_for_string_arg(argvars, 3) == FAIL))
return;
str = tv_get_string_chk(&argvars[0]);
pat = tv_get_string_buf_chk(&argvars[1], patbuf);
flg = tv_get_string_buf_chk(&argvars[3], flagsbuf);
if (argvars[2].v_type == VAR_FUNC || argvars[2].v_type == VAR_PARTIAL)
expr = &argvars[2];