xref: /vim-8.2.3635/src/vim9script.c (revision 8ee52aff)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * vim9script.c: :vim9script, :import, :export and friends
12  */
13 
14 #include "vim.h"
15 
16 #if defined(FEAT_EVAL)
17 # include "vim9.h"
18 #endif
19 
20 /*
21  * Return TRUE when currently using Vim9 script syntax.
22  * Does not go up the stack, a ":function" inside vim9script uses legacy
23  * syntax.
24  */
25     int
26 in_vim9script(void)
27 {
28     // "sc_version" is also set when compiling a ":def" function in legacy
29     // script.
30     return (current_sctx.sc_version == SCRIPT_VERSION_VIM9
31 					 || (cmdmod.cmod_flags & CMOD_VIM9CMD))
32 		&& !(cmdmod.cmod_flags & CMOD_LEGACY);
33 }
34 
35 #if defined(FEAT_EVAL) || defined(PROTO)
36 /*
37  * Return TRUE if the current script is Vim9 script.
38  * This also returns TRUE in a legacy function in a Vim9 script.
39  */
40     int
41 current_script_is_vim9(void)
42 {
43     return SCRIPT_ID_VALID(current_sctx.sc_sid)
44 	    && SCRIPT_ITEM(current_sctx.sc_sid)->sn_version
45 						       == SCRIPT_VERSION_VIM9;
46 }
47 #endif
48 
49 /*
50  * ":vim9script".
51  */
52     void
53 ex_vim9script(exarg_T *eap UNUSED)
54 {
55 #ifdef FEAT_EVAL
56     int		    sid = current_sctx.sc_sid;
57     scriptitem_T    *si;
58 
59     if (!getline_equal(eap->getline, eap->cookie, getsourceline))
60     {
61 	emsg(_(e_vim9script_can_only_be_used_in_script));
62 	return;
63     }
64 
65     si = SCRIPT_ITEM(sid);
66     if (si->sn_state == SN_STATE_HAD_COMMAND)
67     {
68 	emsg(_(e_vim9script_must_be_first_command_in_script));
69 	return;
70     }
71     if (!IS_WHITE_OR_NUL(*eap->arg) && STRCMP(eap->arg, "noclear") != 0)
72     {
73 	semsg(_(e_invarg2), eap->arg);
74 	return;
75     }
76     if (si->sn_state == SN_STATE_RELOAD && IS_WHITE_OR_NUL(*eap->arg))
77     {
78 	hashtab_T	*ht = &SCRIPT_VARS(sid);
79 
80 	// Reloading a script without the "noclear" argument: clear
81 	// script-local variables and functions.
82 	hashtab_free_contents(ht);
83 	hash_init(ht);
84 	delete_script_functions(sid);
85 
86 	// old imports and script variables are no longer valid
87 	free_imports_and_script_vars(sid);
88     }
89     si->sn_state = SN_STATE_HAD_COMMAND;
90 
91     current_sctx.sc_version = SCRIPT_VERSION_VIM9;
92     si->sn_version = SCRIPT_VERSION_VIM9;
93 
94     if (STRCMP(p_cpo, CPO_VIM) != 0)
95     {
96 	si->sn_save_cpo = vim_strsave(p_cpo);
97 	set_option_value((char_u *)"cpo", 0L, (char_u *)CPO_VIM, OPT_NO_REDRAW);
98     }
99 #else
100     // No check for this being the first command, it doesn't matter.
101     current_sctx.sc_version = SCRIPT_VERSION_VIM9;
102 #endif
103 }
104 
105 /*
106  * When in Vim9 script give an error and return FAIL.
107  */
108     int
109 not_in_vim9(exarg_T *eap)
110 {
111     if (in_vim9script())
112 	switch (eap->cmdidx)
113 	{
114 	    case CMD_k:
115 		if (eap->addr_count > 0)
116 		{
117 		    emsg(_(e_norange));
118 		    return FAIL;
119 		}
120 		// FALLTHROUGH
121 	    case CMD_append:
122 	    case CMD_change:
123 	    case CMD_insert:
124 	    case CMD_open:
125 	    case CMD_t:
126 	    case CMD_xit:
127 		semsg(_(e_command_not_supported_in_vim9_script_missing_var_str), eap->cmd);
128 		return FAIL;
129 	    default: break;
130 	}
131     return OK;
132 }
133 
134 /*
135  * Give an error message if "p" points at "#{" and return TRUE.
136  * This avoids that using a legacy style #{} dictionary leads to difficult to
137  * understand errors.
138  */
139     int
140 vim9_bad_comment(char_u *p)
141 {
142     if (p[0] == '#' && p[1] == '{' && p[2] != '{')
143     {
144 	emsg(_(e_cannot_use_hash_curly_to_start_comment));
145 	return TRUE;
146     }
147     return FALSE;
148 }
149 
150 /*
151  * Return TRUE if "p" points at a "#" not followed by one '{'.
152  * Does not check for white space.
153  */
154     int
155 vim9_comment_start(char_u *p)
156 {
157     return p[0] == '#' && (p[1] != '{' || p[2] == '{');
158 }
159 
160 #if defined(FEAT_EVAL) || defined(PROTO)
161 
162 /*
163  * "++nr" and "--nr" commands.
164  */
165     void
166 ex_incdec(exarg_T *eap)
167 {
168     char_u	*cmd = eap->cmd;
169     char_u	*nextcmd = eap->nextcmd;
170     size_t	len = STRLEN(eap->cmd) + 8;
171 
172     if (VIM_ISWHITE(cmd[2]))
173     {
174 	semsg(_(e_no_white_space_allowed_after_str_str),
175 			 eap->cmdidx == CMD_increment ? "++" : "--", eap->cmd);
176 	return;
177     }
178 
179     // This works like "nr += 1" or "nr -= 1".
180     // Add a '|' to avoid looking in the next line.
181     eap->cmd = alloc(len);
182     if (eap->cmd == NULL)
183 	return;
184     vim_snprintf((char *)eap->cmd, len, "%s %c= 1 |", cmd + 2,
185 				     eap->cmdidx == CMD_increment ? '+' : '-');
186     eap->arg = eap->cmd;
187     eap->cmdidx = CMD_var;
188     eap->nextcmd = NULL;
189     ex_let(eap);
190     vim_free(eap->cmd);
191     eap->cmd = cmd;
192     eap->nextcmd = nextcmd;
193 }
194 
195 /*
196  * ":export let Name: type"
197  * ":export const Name: type"
198  * ":export def Name(..."
199  * ":export class Name ..."
200  */
201     void
202 ex_export(exarg_T *eap)
203 {
204     if (!in_vim9script())
205     {
206 	emsg(_(e_export_can_only_be_used_in_vim9script));
207 	return;
208     }
209 
210     eap->cmd = eap->arg;
211     (void)find_ex_command(eap, NULL, lookup_scriptitem, NULL);
212     switch (eap->cmdidx)
213     {
214 	case CMD_let:
215 	case CMD_var:
216 	case CMD_final:
217 	case CMD_const:
218 	case CMD_def:
219 	// case CMD_class:
220 	    is_export = TRUE;
221 	    do_cmdline(eap->cmd, eap->getline, eap->cookie,
222 						DOCMD_VERBOSE + DOCMD_NOWAIT);
223 
224 	    // The command will reset "is_export" when exporting an item.
225 	    if (is_export)
226 	    {
227 		emsg(_(e_export_with_invalid_argument));
228 		is_export = FALSE;
229 	    }
230 	    break;
231 	default:
232 	    emsg(_(e_invalid_command_after_export));
233 	    break;
234     }
235 }
236 
237 /*
238  * Add a new imported item entry to the current script.
239  */
240     static imported_T *
241 new_imported(garray_T *gap)
242 {
243     if (ga_grow(gap, 1) == OK)
244 	return ((imported_T *)gap->ga_data + gap->ga_len++);
245     return NULL;
246 }
247 
248 /*
249  * Free the script variables from "sn_all_vars".
250  */
251     static void
252 free_all_script_vars(scriptitem_T *si)
253 {
254     int		todo;
255     hashtab_T	*ht = &si->sn_all_vars.dv_hashtab;
256     hashitem_T	*hi;
257     sallvar_T	*sav;
258     sallvar_T	*sav_next;
259 
260     hash_lock(ht);
261     todo = (int)ht->ht_used;
262     for (hi = ht->ht_array; todo > 0; ++hi)
263     {
264 	if (!HASHITEM_EMPTY(hi))
265 	{
266 	    --todo;
267 
268 	    // Free the variable.  Don't remove it from the hashtab, ht_array
269 	    // might change then.  hash_clear() takes care of it later.
270 	    sav = HI2SAV(hi);
271 	    while (sav != NULL)
272 	    {
273 		sav_next = sav->sav_next;
274 		if (sav->sav_di == NULL)
275 		    clear_tv(&sav->sav_tv);
276 		vim_free(sav);
277 		sav = sav_next;
278 	    }
279 	}
280     }
281     hash_clear(ht);
282     hash_init(ht);
283 
284     ga_clear(&si->sn_var_vals);
285 
286     // existing commands using script variable indexes are no longer valid
287     si->sn_script_seq = current_sctx.sc_seq;
288 }
289 
290 /*
291  * Free all imported items in script "sid".
292  */
293     void
294 free_imports_and_script_vars(int sid)
295 {
296     scriptitem_T    *si = SCRIPT_ITEM(sid);
297     int		    idx;
298 
299     for (idx = 0; idx < si->sn_imports.ga_len; ++idx)
300     {
301 	imported_T *imp = ((imported_T *)si->sn_imports.ga_data) + idx;
302 
303 	vim_free(imp->imp_name);
304     }
305     ga_clear(&si->sn_imports);
306 
307     free_all_script_vars(si);
308 
309     clear_type_list(&si->sn_type_list);
310 }
311 
312 /*
313  * Mark all imports as possible to redefine.  Used when a script is loaded
314  * again but not cleared.
315  */
316     void
317 mark_imports_for_reload(int sid)
318 {
319     scriptitem_T    *si = SCRIPT_ITEM(sid);
320     int		    idx;
321 
322     for (idx = 0; idx < si->sn_imports.ga_len; ++idx)
323     {
324 	imported_T *imp = ((imported_T *)si->sn_imports.ga_data) + idx;
325 
326 	imp->imp_flags |= IMP_FLAGS_RELOAD;
327     }
328 }
329 
330 /*
331  * Handle an ":import" command and add the resulting imported_T to "gap", when
332  * not NULL, or script "import_sid" sn_imports.
333  * "cctx" is NULL at the script level.
334  * Returns a pointer to after the command or NULL in case of failure
335  */
336     static char_u *
337 handle_import(
338 	char_u	    *arg_start,
339 	garray_T    *gap,
340 	int	    import_sid,
341 	evalarg_T   *evalarg,
342 	void	    *cctx)
343 {
344     char_u	*arg = arg_start;
345     char_u	*cmd_end = NULL;
346     int		ret = FAIL;
347     typval_T	tv;
348     int		sid = -1;
349     int		res;
350     int		mult = FALSE;
351     garray_T	names;
352     garray_T	as_names;
353     long	start_lnum = SOURCING_LNUM;
354 
355     tv.v_type = VAR_UNKNOWN;
356     ga_init2(&names, sizeof(char_u *), 10);
357     ga_init2(&as_names, sizeof(char_u *), 10);
358     if (*arg == '{')
359     {
360 	// "import {item, item} from ..."
361 	mult = TRUE;
362 	arg = skipwhite_and_linebreak(arg + 1, evalarg);
363     }
364 
365     for (;;)
366     {
367 	char_u	    *p = arg;
368 	int	    had_comma = FALSE;
369 	char_u	    *as_name = NULL;
370 
371 	// accept "*" or "Name"
372 	if (!mult && arg[0] == '*' && IS_WHITE_OR_NUL(arg[1]))
373 	    ++arg;
374 	else
375 	    while (eval_isnamec(*arg))
376 		++arg;
377 	if (p == arg)
378 	    break;
379 	if (ga_grow(&names, 1) == FAIL || ga_grow(&as_names, 1) == FAIL)
380 	    goto erret;
381 	((char_u **)names.ga_data)[names.ga_len] = vim_strnsave(p, arg - p);
382 	++names.ga_len;
383 
384 	arg = skipwhite_and_linebreak(arg, evalarg);
385 	if (STRNCMP("as", arg, 2) == 0 && IS_WHITE_OR_NUL(arg[2]))
386 	{
387 	    // skip over "as Name "; no line break allowed after "as"
388 	    arg = skipwhite(arg + 2);
389 	    p = arg;
390 	    if (eval_isnamec1(*arg))
391 		while (eval_isnamec(*arg))
392 		    ++arg;
393 	    if (check_defined(p, arg - p, cctx, FALSE) == FAIL)
394 		goto erret;
395 	    as_name = vim_strnsave(p, arg - p);
396 	    arg = skipwhite_and_linebreak(arg, evalarg);
397 	}
398 	else if (*arg_start == '*')
399 	{
400 	    emsg(_(e_missing_as_after_star));
401 	    goto erret;
402 	}
403 	// without "as Name" the as_names entry is NULL
404 	((char_u **)as_names.ga_data)[as_names.ga_len] = as_name;
405 	++as_names.ga_len;
406 
407 	if (!mult)
408 	    break;
409 	if (*arg == ',')
410 	{
411 	    had_comma = TRUE;
412 	    ++arg;
413 	}
414 	arg = skipwhite_and_linebreak(arg, evalarg);
415 	if (*arg == '}')
416 	{
417 	    ++arg;
418 	    break;
419 	}
420 	if (!had_comma)
421 	{
422 	    emsg(_(e_missing_comma_in_import));
423 	    goto erret;
424 	}
425     }
426     arg = skipwhite_and_linebreak(arg, evalarg);
427 
428     if (names.ga_len == 0)
429     {
430 	emsg(_(e_syntax_error_in_import));
431 	goto erret;
432     }
433 
434     if (STRNCMP("from", arg, 4) != 0 || !IS_WHITE_OR_NUL(arg[4]))
435     {
436 	emsg(_(e_missing_from));
437 	goto erret;
438     }
439 
440     // The name of the file can be an expression, which must evaluate to a
441     // string.
442     arg = skipwhite_and_linebreak(arg + 4, evalarg);
443     ret = eval0(arg, &tv, NULL, evalarg);
444     if (ret == FAIL)
445 	goto erret;
446     if (tv.v_type != VAR_STRING
447 		       || tv.vval.v_string == NULL || *tv.vval.v_string == NUL)
448     {
449 	emsg(_(e_invalid_string_after_from));
450 	goto erret;
451     }
452     cmd_end = arg;
453 
454     // Give error messages for the start of the line.
455     SOURCING_LNUM = start_lnum;
456 
457     /*
458      * find script file
459      */
460     if (*tv.vval.v_string == '.')
461     {
462 	size_t		len;
463 	scriptitem_T	*si = SCRIPT_ITEM(current_sctx.sc_sid);
464 	char_u		*tail = gettail(si->sn_name);
465 	char_u		*from_name;
466 
467 	// Relative to current script: "./name.vim", "../../name.vim".
468 	len = STRLEN(si->sn_name) - STRLEN(tail) + STRLEN(tv.vval.v_string) + 2;
469 	from_name = alloc((int)len);
470 	if (from_name == NULL)
471 	    goto erret;
472 	vim_strncpy(from_name, si->sn_name, tail - si->sn_name);
473 	add_pathsep(from_name);
474 	STRCAT(from_name, tv.vval.v_string);
475 	simplify_filename(from_name);
476 
477 	res = do_source(from_name, FALSE, DOSO_NONE, &sid);
478 	vim_free(from_name);
479     }
480     else if (mch_isFullName(tv.vval.v_string))
481     {
482 	// Absolute path: "/tmp/name.vim"
483 	res = do_source(tv.vval.v_string, FALSE, DOSO_NONE, &sid);
484     }
485     else
486     {
487 	size_t	    len = 7 + STRLEN(tv.vval.v_string) + 1;
488 	char_u	    *from_name;
489 
490 	// Find file in "import" subdirs in 'runtimepath'.
491 	from_name = alloc((int)len);
492 	if (from_name == NULL)
493 	{
494 	    goto erret;
495 	}
496 	vim_snprintf((char *)from_name, len, "import/%s", tv.vval.v_string);
497 	res = source_in_path(p_rtp, from_name, DIP_NOAFTER, &sid);
498 	vim_free(from_name);
499     }
500 
501     if (res == FAIL || sid <= 0)
502     {
503 	semsg(_(e_could_not_import_str), tv.vval.v_string);
504 	goto erret;
505     }
506 
507     if (*arg_start == '*')
508     {
509 	imported_T  *imported;
510 	char_u	    *as_name = ((char_u **)as_names.ga_data)[0];
511 
512 	// "import * as That"
513 	imported = find_imported(as_name, STRLEN(as_name), cctx);
514 	if (imported != NULL && imported->imp_sid == sid)
515 	{
516 	    if (imported->imp_flags & IMP_FLAGS_RELOAD)
517 		// import already defined on a previous script load
518 		imported->imp_flags &= ~IMP_FLAGS_RELOAD;
519 	    else
520 	    {
521 		semsg(_(e_name_already_defined_str), as_name);
522 		goto erret;
523 	    }
524 	}
525 
526 	imported = new_imported(gap != NULL ? gap
527 					: &SCRIPT_ITEM(import_sid)->sn_imports);
528 	if (imported == NULL)
529 	    goto erret;
530 	imported->imp_name = as_name;
531 	((char_u **)as_names.ga_data)[0] = NULL;
532 	imported->imp_sid = sid;
533 	imported->imp_flags = IMP_FLAGS_STAR;
534     }
535     else
536     {
537 	int i;
538 
539 	arg = arg_start;
540 	if (*arg == '{')
541 	    arg = skipwhite(arg + 1);
542 	for (i = 0; i < names.ga_len; ++i)
543 	{
544 	    char_u	*name = ((char_u **)names.ga_data)[i];
545 	    char_u	*as_name = ((char_u **)as_names.ga_data)[i];
546 	    size_t	len = STRLEN(name);
547 	    int		idx;
548 	    imported_T	*imported;
549 	    ufunc_T	*ufunc = NULL;
550 	    type_T	*type;
551 
552 	    idx = find_exported(sid, name, &ufunc, &type, cctx, TRUE);
553 
554 	    if (idx < 0 && ufunc == NULL)
555 		goto erret;
556 
557 	    // If already imported with the same properties and the
558 	    // IMP_FLAGS_RELOAD set then we keep that entry.  Otherwise create
559 	    // a new one (and give an error for an existing import).
560 	    imported = find_imported(name, len, cctx);
561 	    if (imported != NULL
562 		    && (imported->imp_flags & IMP_FLAGS_RELOAD)
563 		    && imported->imp_sid == sid
564 		    && (idx >= 0
565 			? (equal_type(imported->imp_type, type, 0)
566 			    && imported->imp_var_vals_idx == idx)
567 			: (equal_type(imported->imp_type, ufunc->uf_func_type,
568 							     ETYPE_ARG_UNKNOWN)
569 			    && STRCMP(imported->imp_funcname,
570 							ufunc->uf_name) == 0)))
571 	    {
572 		imported->imp_flags &= ~IMP_FLAGS_RELOAD;
573 	    }
574 	    else
575 	    {
576 		if (as_name == NULL
577 			      && check_defined(name, len, cctx, FALSE) == FAIL)
578 		    goto erret;
579 
580 		imported = new_imported(gap != NULL ? gap
581 				       : &SCRIPT_ITEM(import_sid)->sn_imports);
582 		if (imported == NULL)
583 		    goto erret;
584 
585 		if (as_name == NULL)
586 		{
587 		    imported->imp_name = name;
588 		    ((char_u **)names.ga_data)[i] = NULL;
589 		}
590 		else
591 		{
592 		    // "import This as That ..."
593 		    imported->imp_name = as_name;
594 		    ((char_u **)as_names.ga_data)[i] = NULL;
595 		}
596 		imported->imp_sid = sid;
597 		if (idx >= 0)
598 		{
599 		    imported->imp_type = type;
600 		    imported->imp_var_vals_idx = idx;
601 		}
602 		else
603 		{
604 		    imported->imp_type = ufunc->uf_func_type;
605 		    imported->imp_funcname = ufunc->uf_name;
606 		}
607 	    }
608 	}
609     }
610 erret:
611     clear_tv(&tv);
612     ga_clear_strings(&names);
613     ga_clear_strings(&as_names);
614     return cmd_end;
615 }
616 
617 /*
618  * ":import Item from 'filename'"
619  * ":import Item as Alias from 'filename'"
620  * ":import {Item} from 'filename'".
621  * ":import {Item as Alias} from 'filename'"
622  * ":import {Item, Item} from 'filename'"
623  * ":import {Item, Item as Alias} from 'filename'"
624  *
625  * ":import * as Name from 'filename'"
626  */
627     void
628 ex_import(exarg_T *eap)
629 {
630     char_u	*cmd_end;
631     evalarg_T	evalarg;
632 
633     if (!getline_equal(eap->getline, eap->cookie, getsourceline))
634     {
635 	emsg(_(e_import_can_only_be_used_in_script));
636 	return;
637     }
638     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
639 
640     cmd_end = handle_import(eap->arg, NULL, current_sctx.sc_sid,
641 							       &evalarg, NULL);
642     if (cmd_end != NULL)
643 	set_nextcmd(eap, cmd_end);
644     clear_evalarg(&evalarg, eap);
645 }
646 
647 /*
648  * Find an exported item in "sid" matching the name at "*argp".
649  * When it is a variable return the index.
650  * When it is a user function return "*ufunc".
651  * When not found returns -1 and "*ufunc" is NULL.
652  */
653     int
654 find_exported(
655 	int	    sid,
656 	char_u	    *name,
657 	ufunc_T	    **ufunc,
658 	type_T	    **type,
659 	cctx_T	    *cctx,
660 	int	    verbose)
661 {
662     int		idx = -1;
663     svar_T	*sv;
664     scriptitem_T *script = SCRIPT_ITEM(sid);
665 
666     // Find name in "script".
667     idx = get_script_item_idx(sid, name, 0, cctx);
668     if (idx >= 0)
669     {
670 	sv = ((svar_T *)script->sn_var_vals.ga_data) + idx;
671 	if (!sv->sv_export)
672 	{
673 	    if (verbose)
674 		semsg(_(e_item_not_exported_in_script_str), name);
675 	    return -1;
676 	}
677 	*type = sv->sv_type;
678 	*ufunc = NULL;
679     }
680     else
681     {
682 	char_u	buffer[200];
683 	char_u	*funcname;
684 
685 	// it could be a user function.
686 	if (STRLEN(name) < sizeof(buffer) - 15)
687 	    funcname = buffer;
688 	else
689 	{
690 	    funcname = alloc(STRLEN(name) + 15);
691 	    if (funcname == NULL)
692 		return -1;
693 	}
694 	funcname[0] = K_SPECIAL;
695 	funcname[1] = KS_EXTRA;
696 	funcname[2] = (int)KE_SNR;
697 	sprintf((char *)funcname + 3, "%ld_%s", (long)sid, name);
698 	*ufunc = find_func(funcname, FALSE, NULL);
699 	if (funcname != buffer)
700 	    vim_free(funcname);
701 
702 	if (*ufunc == NULL)
703 	{
704 	    if (verbose)
705 		semsg(_(e_item_not_found_in_script_str), name);
706 	    return -1;
707 	}
708 	else if (((*ufunc)->uf_flags & FC_EXPORT) == 0)
709 	{
710 	    if (verbose)
711 		semsg(_(e_item_not_exported_in_script_str), name);
712 	    *ufunc = NULL;
713 	    return -1;
714 	}
715     }
716 
717     return idx;
718 }
719 
720 /*
721  * Declare a script-local variable without init: "let var: type".
722  * "const" is an error since the value is missing.
723  * Returns a pointer to after the type.
724  */
725     char_u *
726 vim9_declare_scriptvar(exarg_T *eap, char_u *arg)
727 {
728     char_u	    *p;
729     char_u	    *name;
730     scriptitem_T    *si = SCRIPT_ITEM(current_sctx.sc_sid);
731     type_T	    *type;
732     typval_T	    init_tv;
733 
734     if (eap->cmdidx == CMD_final || eap->cmdidx == CMD_const)
735     {
736 	if (eap->cmdidx == CMD_final)
737 	    emsg(_(e_final_requires_a_value));
738 	else
739 	    emsg(_(e_const_requires_a_value));
740 	return arg + STRLEN(arg);
741     }
742 
743     // Check for valid starting character.
744     if (!eval_isnamec1(*arg))
745     {
746 	semsg(_(e_invarg2), arg);
747 	return arg + STRLEN(arg);
748     }
749 
750     for (p = arg + 1; *p != NUL && eval_isnamec(*p); MB_PTR_ADV(p))
751 	if (*p == ':' && (VIM_ISWHITE(p[1]) || p != arg + 1))
752 	    break;
753 
754     if (*p != ':')
755     {
756 	emsg(_(e_type_or_initialization_required));
757 	return arg + STRLEN(arg);
758     }
759     if (!VIM_ISWHITE(p[1]))
760     {
761 	semsg(_(e_white_space_required_after_str_str), ":", p);
762 	return arg + STRLEN(arg);
763     }
764     name = vim_strnsave(arg, p - arg);
765 
766     // parse type, check for reserved name
767     p = skipwhite(p + 1);
768     type = parse_type(&p, &si->sn_type_list, TRUE);
769     if (type == NULL || check_reserved_name(name) == FAIL)
770     {
771 	vim_free(name);
772 	return p;
773     }
774 
775     // Create the variable with 0/NULL value.
776     CLEAR_FIELD(init_tv);
777     if (type->tt_type == VAR_ANY)
778 	// A variable of type "any" is not possible, just use zero instead
779 	init_tv.v_type = VAR_NUMBER;
780     else
781 	init_tv.v_type = type->tt_type;
782     set_var_const(name, type, &init_tv, FALSE, 0, 0);
783 
784     vim_free(name);
785     return p;
786 }
787 
788 /*
789  * Vim9 part of adding a script variable: add it to sn_all_vars (lookup by name
790  * with a hashtable) and sn_var_vals (lookup by index).
791  * When "create" is TRUE this is a new variable, otherwise find and update an
792  * existing variable.
793  * "flags" can have ASSIGN_FINAL or ASSIGN_CONST.
794  * When "*type" is NULL use "tv" for the type and update "*type".  If
795  * "do_member" is TRUE also use the member type, otherwise use "any".
796  */
797     void
798 update_vim9_script_var(
799 	int	    create,
800 	dictitem_T  *di,
801 	int	    flags,
802 	typval_T    *tv,
803 	type_T	    **type,
804 	int	    do_member)
805 {
806     scriptitem_T    *si = SCRIPT_ITEM(current_sctx.sc_sid);
807     hashitem_T	    *hi;
808     svar_T	    *sv = NULL;
809 
810     if (create)
811     {
812 	sallvar_T   *newsav;
813 	sallvar_T   *sav = NULL;
814 
815 	// Store a pointer to the typval_T, so that it can be found by index
816 	// instead of using a hastab lookup.
817 	if (ga_grow(&si->sn_var_vals, 1) == FAIL)
818 	    return;
819 
820 	hi = hash_find(&si->sn_all_vars.dv_hashtab, di->di_key);
821 	if (!HASHITEM_EMPTY(hi))
822 	{
823 	    // Variable with this name exists, either in this block or in
824 	    // another block.
825 	    for (sav = HI2SAV(hi); ; sav = sav->sav_next)
826 	    {
827 		if (sav->sav_block_id == si->sn_current_block_id)
828 		{
829 		    // variable defined in a loop, re-use the entry
830 		    sv = ((svar_T *)si->sn_var_vals.ga_data)
831 						       + sav->sav_var_vals_idx;
832 		    // unhide the variable
833 		    if (sv->sv_tv == &sav->sav_tv)
834 		    {
835 			clear_tv(&sav->sav_tv);
836 			sv->sv_tv = &di->di_tv;
837 			sav->sav_di = di;
838 		    }
839 		    break;
840 		}
841 		if (sav->sav_next == NULL)
842 		    break;
843 	    }
844 	}
845 
846 	if (sv == NULL)
847 	{
848 	    // Variable not defined or not defined in current block: Add a
849 	    // svar_T and create a new sallvar_T.
850 	    sv = ((svar_T *)si->sn_var_vals.ga_data) + si->sn_var_vals.ga_len;
851 	    newsav = (sallvar_T *)alloc_clear(
852 				       sizeof(sallvar_T) + STRLEN(di->di_key));
853 	    if (newsav == NULL)
854 		return;
855 
856 	    sv->sv_tv = &di->di_tv;
857 	    sv->sv_const = (flags & ASSIGN_FINAL) ? ASSIGN_FINAL
858 				   : (flags & ASSIGN_CONST) ? ASSIGN_CONST : 0;
859 	    sv->sv_export = is_export;
860 	    newsav->sav_var_vals_idx = si->sn_var_vals.ga_len;
861 	    ++si->sn_var_vals.ga_len;
862 	    STRCPY(&newsav->sav_key, di->di_key);
863 	    sv->sv_name = newsav->sav_key;
864 	    newsav->sav_di = di;
865 	    newsav->sav_block_id = si->sn_current_block_id;
866 
867 	    if (HASHITEM_EMPTY(hi))
868 		// new variable name
869 		hash_add(&si->sn_all_vars.dv_hashtab, newsav->sav_key);
870 	    else if (sav != NULL)
871 		// existing name in a new block, append to the list
872 		sav->sav_next = newsav;
873 	}
874     }
875     else
876     {
877 	sv = find_typval_in_script(&di->di_tv);
878     }
879     if (sv != NULL)
880     {
881 	if (*type == NULL)
882 	    *type = typval2type(tv, get_copyID(), &si->sn_type_list, do_member);
883 	sv->sv_type = *type;
884     }
885 
886     // let ex_export() know the export worked.
887     is_export = FALSE;
888 }
889 
890 /*
891  * Hide a script variable when leaving a block.
892  * "idx" is de index in sn_var_vals.
893  * When "func_defined" is non-zero then a function was defined in this block,
894  * the variable may be accessed by it.  Otherwise the variable can be cleared.
895  */
896     void
897 hide_script_var(scriptitem_T *si, int idx, int func_defined)
898 {
899     svar_T	*sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
900     hashtab_T	*script_ht = get_script_local_ht();
901     hashtab_T	*all_ht = &si->sn_all_vars.dv_hashtab;
902     hashitem_T	*script_hi;
903     hashitem_T	*all_hi;
904 
905     // Remove a variable declared inside the block, if it still exists.
906     // If it was added in a nested block it will already have been removed.
907     // The typval is moved into the sallvar_T.
908     script_hi = hash_find(script_ht, sv->sv_name);
909     all_hi = hash_find(all_ht, sv->sv_name);
910     if (!HASHITEM_EMPTY(script_hi) && !HASHITEM_EMPTY(all_hi))
911     {
912 	dictitem_T	*di = HI2DI(script_hi);
913 	sallvar_T	*sav = HI2SAV(all_hi);
914 	sallvar_T	*sav_prev = NULL;
915 
916 	// There can be multiple entries with the same name in different
917 	// blocks, find the right one.
918 	while (sav != NULL && sav->sav_var_vals_idx != idx)
919 	{
920 	    sav_prev = sav;
921 	    sav = sav->sav_next;
922 	}
923 	if (sav != NULL)
924 	{
925 	    if (func_defined)
926 	    {
927 		// move the typval from the dictitem to the sallvar
928 		sav->sav_tv = di->di_tv;
929 		di->di_tv.v_type = VAR_UNKNOWN;
930 		sav->sav_flags = di->di_flags;
931 		sav->sav_di = NULL;
932 		sv->sv_tv = &sav->sav_tv;
933 	    }
934 	    else
935 	    {
936 		if (sav_prev == NULL)
937 		    hash_remove(all_ht, all_hi);
938 		else
939 		    sav_prev->sav_next = sav->sav_next;
940 		sv->sv_name = NULL;
941 		vim_free(sav);
942 	    }
943 	    delete_var(script_ht, script_hi);
944 	}
945     }
946 }
947 
948 /*
949  * Find the script-local variable that links to "dest".
950  * Returns NULL if not found and give an internal error.
951  */
952     svar_T *
953 find_typval_in_script(typval_T *dest)
954 {
955     scriptitem_T    *si = SCRIPT_ITEM(current_sctx.sc_sid);
956     int		    idx;
957 
958     if (si->sn_version != SCRIPT_VERSION_VIM9)
959 	// legacy script doesn't store variable types
960 	return NULL;
961 
962     // Find the svar_T in sn_var_vals.
963     for (idx = 0; idx < si->sn_var_vals.ga_len; ++idx)
964     {
965 	svar_T    *sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
966 
967 	// If "sv_name" is NULL the variable was hidden when leaving a block,
968 	// don't check "sv_tv" then, it might be used for another variable now.
969 	if (sv->sv_name != NULL && sv->sv_tv == dest)
970 	    return sv;
971     }
972     iemsg("find_typval_in_script(): not found");
973     return NULL;
974 }
975 
976 /*
977  * Check if the type of script variable "dest" allows assigning "value".
978  * If needed convert "value" to a bool.
979  */
980     int
981 check_script_var_type(
982 	typval_T    *dest,
983 	typval_T    *value,
984 	char_u	    *name,
985 	where_T	    where)
986 {
987     svar_T  *sv = find_typval_in_script(dest);
988     int	    ret;
989 
990     if (sv != NULL)
991     {
992 	if (sv->sv_const != 0)
993 	{
994 	    semsg(_(e_cannot_change_readonly_variable_str), name);
995 	    return FAIL;
996 	}
997 	ret = check_typval_type(sv->sv_type, value, where);
998 	if (ret == OK && need_convert_to_bool(sv->sv_type, value))
999 	{
1000 	    int	val = tv2bool(value);
1001 
1002 	    clear_tv(value);
1003 	    value->v_type = VAR_BOOL;
1004 	    value->v_lock = 0;
1005 	    value->vval.v_number = val ? VVAL_TRUE : VVAL_FALSE;
1006 	}
1007 	return ret;
1008     }
1009 
1010     return OK; // not really
1011 }
1012 
1013 // words that cannot be used as a variable
1014 static char *reserved[] = {
1015     "true",
1016     "false",
1017     "null",
1018     "this",
1019     NULL
1020 };
1021 
1022     int
1023 check_reserved_name(char_u *name)
1024 {
1025     int idx;
1026 
1027     for (idx = 0; reserved[idx] != NULL; ++idx)
1028 	if (STRCMP(reserved[idx], name) == 0)
1029 	{
1030 	    semsg(_(e_cannot_use_reserved_name), name);
1031 	    return FAIL;
1032 	}
1033     return OK;
1034 }
1035 
1036 #endif // FEAT_EVAL
1037