xref: /vim-8.2.3635/src/vim9script.c (revision f3d30842)
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86 	// old imports and script variables are no longer valid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     // This works like "nr += 1" or "nr -= 1".
173     // Add a '|' to avoid looking in the next line.
174     eap->cmd = alloc(len);
175     if (eap->cmd == NULL)
176 	return;
177     vim_snprintf((char *)eap->cmd, len, "%s %c= 1 |", cmd + 2,
178 				     eap->cmdidx == CMD_increment ? '+' : '-');
179     eap->arg = eap->cmd;
180     eap->cmdidx = CMD_var;
181     eap->nextcmd = NULL;
182     ex_let(eap);
183     vim_free(eap->cmd);
184     eap->cmd = cmd;
185     eap->nextcmd = nextcmd;
186 }
187 
188 /*
189  * ":export let Name: type"
190  * ":export const Name: type"
191  * ":export def Name(..."
192  * ":export class Name ..."
193  */
194     void
195 ex_export(exarg_T *eap)
196 {
197     if (!in_vim9script())
198     {
199 	emsg(_(e_export_can_only_be_used_in_vim9script));
200 	return;
201     }
202 
203     eap->cmd = eap->arg;
204     (void)find_ex_command(eap, NULL, lookup_scriptitem, NULL);
205     switch (eap->cmdidx)
206     {
207 	case CMD_let:
208 	case CMD_var:
209 	case CMD_final:
210 	case CMD_const:
211 	case CMD_def:
212 	// case CMD_class:
213 	    is_export = TRUE;
214 	    do_cmdline(eap->cmd, eap->getline, eap->cookie,
215 						DOCMD_VERBOSE + DOCMD_NOWAIT);
216 
217 	    // The command will reset "is_export" when exporting an item.
218 	    if (is_export)
219 	    {
220 		emsg(_(e_export_with_invalid_argument));
221 		is_export = FALSE;
222 	    }
223 	    break;
224 	default:
225 	    emsg(_(e_invalid_command_after_export));
226 	    break;
227     }
228 }
229 
230 /*
231  * Add a new imported item entry to the current script.
232  */
233     static imported_T *
234 new_imported(garray_T *gap)
235 {
236     if (ga_grow(gap, 1) == OK)
237 	return ((imported_T *)gap->ga_data + gap->ga_len++);
238     return NULL;
239 }
240 
241 /*
242  * Free all imported items in script "sid".
243  */
244     void
245 free_imports_and_script_vars(int sid)
246 {
247     scriptitem_T    *si = SCRIPT_ITEM(sid);
248     int		    idx;
249 
250     for (idx = 0; idx < si->sn_imports.ga_len; ++idx)
251     {
252 	imported_T *imp = ((imported_T *)si->sn_imports.ga_data) + idx;
253 
254 	vim_free(imp->imp_name);
255     }
256     ga_clear(&si->sn_imports);
257 
258     free_all_script_vars(si);
259 
260     clear_type_list(&si->sn_type_list);
261 }
262 
263 /*
264  * Mark all imports as possible to redefine.  Used when a script is loaded
265  * again but not cleared.
266  */
267     void
268 mark_imports_for_reload(int sid)
269 {
270     scriptitem_T    *si = SCRIPT_ITEM(sid);
271     int		    idx;
272 
273     for (idx = 0; idx < si->sn_imports.ga_len; ++idx)
274     {
275 	imported_T *imp = ((imported_T *)si->sn_imports.ga_data) + idx;
276 
277 	imp->imp_flags |= IMP_FLAGS_RELOAD;
278     }
279 }
280 
281 /*
282  * ":import Item from 'filename'"
283  * ":import Item as Alias from 'filename'"
284  * ":import {Item} from 'filename'".
285  * ":import {Item as Alias} from 'filename'"
286  * ":import {Item, Item} from 'filename'"
287  * ":import {Item, Item as Alias} from 'filename'"
288  *
289  * ":import * as Name from 'filename'"
290  */
291     void
292 ex_import(exarg_T *eap)
293 {
294     char_u	*cmd_end;
295     evalarg_T	evalarg;
296 
297     if (!getline_equal(eap->getline, eap->cookie, getsourceline))
298     {
299 	emsg(_(e_import_can_only_be_used_in_script));
300 	return;
301     }
302     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
303 
304     cmd_end = handle_import(eap->arg, NULL, current_sctx.sc_sid,
305 							       &evalarg, NULL);
306     if (cmd_end != NULL)
307 	eap->nextcmd = check_nextcmd(cmd_end);
308     clear_evalarg(&evalarg, eap);
309 }
310 
311 /*
312  * Find an exported item in "sid" matching the name at "*argp".
313  * When it is a variable return the index.
314  * When it is a user function return "*ufunc".
315  * When not found returns -1 and "*ufunc" is NULL.
316  */
317     int
318 find_exported(
319 	int	    sid,
320 	char_u	    *name,
321 	ufunc_T	    **ufunc,
322 	type_T	    **type,
323 	cctx_T	    *cctx,
324 	int	    verbose)
325 {
326     int		idx = -1;
327     svar_T	*sv;
328     scriptitem_T *script = SCRIPT_ITEM(sid);
329 
330     // Find name in "script".
331     idx = get_script_item_idx(sid, name, 0, cctx);
332     if (idx >= 0)
333     {
334 	sv = ((svar_T *)script->sn_var_vals.ga_data) + idx;
335 	if (!sv->sv_export)
336 	{
337 	    if (verbose)
338 		semsg(_(e_item_not_exported_in_script_str), name);
339 	    return -1;
340 	}
341 	*type = sv->sv_type;
342 	*ufunc = NULL;
343     }
344     else
345     {
346 	char_u	buffer[200];
347 	char_u	*funcname;
348 
349 	// it could be a user function.
350 	if (STRLEN(name) < sizeof(buffer) - 15)
351 	    funcname = buffer;
352 	else
353 	{
354 	    funcname = alloc(STRLEN(name) + 15);
355 	    if (funcname == NULL)
356 		return -1;
357 	}
358 	funcname[0] = K_SPECIAL;
359 	funcname[1] = KS_EXTRA;
360 	funcname[2] = (int)KE_SNR;
361 	sprintf((char *)funcname + 3, "%ld_%s", (long)sid, name);
362 	*ufunc = find_func(funcname, FALSE, NULL);
363 	if (funcname != buffer)
364 	    vim_free(funcname);
365 
366 	if (*ufunc == NULL)
367 	{
368 	    if (verbose)
369 		semsg(_(e_item_not_found_in_script_str), name);
370 	    return -1;
371 	}
372 	else if (((*ufunc)->uf_flags & FC_EXPORT) == 0)
373 	{
374 	    if (verbose)
375 		semsg(_(e_item_not_exported_in_script_str), name);
376 	    *ufunc = NULL;
377 	    return -1;
378 	}
379     }
380 
381     return idx;
382 }
383 
384 /*
385  * Handle an ":import" command and add the resulting imported_T to "gap", when
386  * not NULL, or script "import_sid" sn_imports.
387  * "cctx" is NULL at the script level.
388  * Returns a pointer to after the command or NULL in case of failure
389  */
390     char_u *
391 handle_import(
392 	char_u	    *arg_start,
393 	garray_T    *gap,
394 	int	    import_sid,
395 	evalarg_T   *evalarg,
396 	void	    *cctx)
397 {
398     char_u	*arg = arg_start;
399     char_u	*cmd_end = NULL;
400     int		ret = FAIL;
401     typval_T	tv;
402     int		sid = -1;
403     int		res;
404     int		mult = FALSE;
405     garray_T	names;
406     garray_T	as_names;
407 
408     ga_init2(&names, sizeof(char_u *), 10);
409     ga_init2(&as_names, sizeof(char_u *), 10);
410     if (*arg == '{')
411     {
412 	// "import {item, item} from ..."
413 	mult = TRUE;
414 	arg = skipwhite_and_linebreak(arg + 1, evalarg);
415     }
416 
417     for (;;)
418     {
419 	char_u	    *p = arg;
420 	int	    had_comma = FALSE;
421 	char_u	    *as_name = NULL;
422 
423 	// accept "*" or "Name"
424 	if (!mult && arg[0] == '*' && IS_WHITE_OR_NUL(arg[1]))
425 	    ++arg;
426 	else
427 	    while (eval_isnamec(*arg))
428 		++arg;
429 	if (p == arg)
430 	    break;
431 	if (ga_grow(&names, 1) == FAIL || ga_grow(&as_names, 1) == FAIL)
432 	    goto erret;
433 	((char_u **)names.ga_data)[names.ga_len] = vim_strnsave(p, arg - p);
434 	++names.ga_len;
435 
436 	arg = skipwhite_and_linebreak(arg, evalarg);
437 	if (STRNCMP("as", arg, 2) == 0 && IS_WHITE_OR_NUL(arg[2]))
438 	{
439 	    // skip over "as Name "; no line break allowed after "as"
440 	    arg = skipwhite(arg + 2);
441 	    p = arg;
442 	    if (eval_isnamec1(*arg))
443 		while (eval_isnamec(*arg))
444 		    ++arg;
445 	    if (check_defined(p, arg - p, cctx, FALSE) == FAIL)
446 		goto erret;
447 	    as_name = vim_strnsave(p, arg - p);
448 	    arg = skipwhite_and_linebreak(arg, evalarg);
449 	}
450 	else if (*arg_start == '*')
451 	{
452 	    emsg(_(e_missing_as_after_star));
453 	    goto erret;
454 	}
455 	// without "as Name" the as_names entry is NULL
456 	((char_u **)as_names.ga_data)[as_names.ga_len] = as_name;
457 	++as_names.ga_len;
458 
459 	if (!mult)
460 	    break;
461 	if (*arg == ',')
462 	{
463 	    had_comma = TRUE;
464 	    ++arg;
465 	}
466 	arg = skipwhite_and_linebreak(arg, evalarg);
467 	if (*arg == '}')
468 	{
469 	    ++arg;
470 	    break;
471 	}
472 	if (!had_comma)
473 	{
474 	    emsg(_(e_missing_comma_in_import));
475 	    goto erret;
476 	}
477     }
478     arg = skipwhite_and_linebreak(arg, evalarg);
479 
480     if (names.ga_len == 0)
481     {
482 	emsg(_(e_syntax_error_in_import));
483 	goto erret;
484     }
485 
486     if (STRNCMP("from", arg, 4) != 0 || !IS_WHITE_OR_NUL(arg[4]))
487     {
488 	emsg(_(e_missing_from));
489 	goto erret;
490     }
491 
492     arg = skipwhite_and_linebreak(arg + 4, evalarg);
493     tv.v_type = VAR_UNKNOWN;
494     // TODO: should we accept any expression?
495     if (*arg == '\'')
496 	ret = eval_lit_string(&arg, &tv, TRUE);
497     else if (*arg == '"')
498 	ret = eval_string(&arg, &tv, TRUE);
499     if (ret == FAIL || tv.vval.v_string == NULL || *tv.vval.v_string == NUL)
500     {
501 	emsg(_(e_invalid_string_after_from));
502 	goto erret;
503     }
504     cmd_end = arg;
505 
506     /*
507      * find script file
508      */
509     if (*tv.vval.v_string == '.')
510     {
511 	size_t		len;
512 	scriptitem_T	*si = SCRIPT_ITEM(current_sctx.sc_sid);
513 	char_u		*tail = gettail(si->sn_name);
514 	char_u		*from_name;
515 
516 	// Relative to current script: "./name.vim", "../../name.vim".
517 	len = STRLEN(si->sn_name) - STRLEN(tail) + STRLEN(tv.vval.v_string) + 2;
518 	from_name = alloc((int)len);
519 	if (from_name == NULL)
520 	{
521 	    clear_tv(&tv);
522 	    goto erret;
523 	}
524 	vim_strncpy(from_name, si->sn_name, tail - si->sn_name);
525 	add_pathsep(from_name);
526 	STRCAT(from_name, tv.vval.v_string);
527 	simplify_filename(from_name);
528 
529 	res = do_source(from_name, FALSE, DOSO_NONE, &sid);
530 	vim_free(from_name);
531     }
532     else if (mch_isFullName(tv.vval.v_string))
533     {
534 	// Absolute path: "/tmp/name.vim"
535 	res = do_source(tv.vval.v_string, FALSE, DOSO_NONE, &sid);
536     }
537     else
538     {
539 	size_t	    len = 7 + STRLEN(tv.vval.v_string) + 1;
540 	char_u	    *from_name;
541 
542 	// Find file in "import" subdirs in 'runtimepath'.
543 	from_name = alloc((int)len);
544 	if (from_name == NULL)
545 	{
546 	    clear_tv(&tv);
547 	    goto erret;
548 	}
549 	vim_snprintf((char *)from_name, len, "import/%s", tv.vval.v_string);
550 	res = source_in_path(p_rtp, from_name, DIP_NOAFTER, &sid);
551 	vim_free(from_name);
552     }
553 
554     if (res == FAIL || sid <= 0)
555     {
556 	semsg(_(e_could_not_import_str), tv.vval.v_string);
557 	clear_tv(&tv);
558 	goto erret;
559     }
560     clear_tv(&tv);
561 
562     if (*arg_start == '*')
563     {
564 	imported_T  *imported;
565 	char_u	    *as_name = ((char_u **)as_names.ga_data)[0];
566 
567 	// "import * as That"
568 	imported = find_imported(as_name, STRLEN(as_name), cctx);
569 	if (imported != NULL && imported->imp_sid == sid)
570 	{
571 	    if (imported->imp_flags & IMP_FLAGS_RELOAD)
572 		// import already defined on a previous script load
573 		imported->imp_flags &= ~IMP_FLAGS_RELOAD;
574 	    else
575 	    {
576 		semsg(_(e_name_already_defined_str), as_name);
577 		goto erret;
578 	    }
579 	}
580 
581 	imported = new_imported(gap != NULL ? gap
582 					: &SCRIPT_ITEM(import_sid)->sn_imports);
583 	if (imported == NULL)
584 	    goto erret;
585 	imported->imp_name = as_name;
586 	((char_u **)as_names.ga_data)[0] = NULL;
587 	imported->imp_sid = sid;
588 	imported->imp_flags = IMP_FLAGS_STAR;
589     }
590     else
591     {
592 	int i;
593 
594 	arg = arg_start;
595 	if (*arg == '{')
596 	    arg = skipwhite(arg + 1);
597 	for (i = 0; i < names.ga_len; ++i)
598 	{
599 	    char_u	*name = ((char_u **)names.ga_data)[i];
600 	    char_u	*as_name = ((char_u **)as_names.ga_data)[i];
601 	    size_t	len = STRLEN(name);
602 	    int		idx;
603 	    imported_T	*imported;
604 	    ufunc_T	*ufunc = NULL;
605 	    type_T	*type;
606 
607 	    idx = find_exported(sid, name, &ufunc, &type, cctx, TRUE);
608 
609 	    if (idx < 0 && ufunc == NULL)
610 		goto erret;
611 
612 	    // If already imported with the same propertis and the
613 	    // IMP_FLAGS_RELOAD set then we keep that entry.  Otherwise create
614 	    // a new one (and give an error for an existing import).
615 	    imported = find_imported(name, len, cctx);
616 	    if (imported != NULL
617 		    && (imported->imp_flags & IMP_FLAGS_RELOAD)
618 		    && imported->imp_sid == sid
619 		    && (idx >= 0
620 			? (equal_type(imported->imp_type, type)
621 			    && imported->imp_var_vals_idx == idx)
622 			: (equal_type(imported->imp_type, ufunc->uf_func_type)
623 			    && STRCMP(imported->imp_funcname,
624 							ufunc->uf_name) == 0)))
625 	    {
626 		imported->imp_flags &= ~IMP_FLAGS_RELOAD;
627 	    }
628 	    else
629 	    {
630 		if (as_name == NULL
631 			      && check_defined(name, len, cctx, FALSE) == FAIL)
632 		    goto erret;
633 
634 		imported = new_imported(gap != NULL ? gap
635 				       : &SCRIPT_ITEM(import_sid)->sn_imports);
636 		if (imported == NULL)
637 		    goto erret;
638 
639 		if (as_name == NULL)
640 		{
641 		    imported->imp_name = name;
642 		    ((char_u **)names.ga_data)[i] = NULL;
643 		}
644 		else
645 		{
646 		    // "import This as That ..."
647 		    imported->imp_name = as_name;
648 		    ((char_u **)as_names.ga_data)[i] = NULL;
649 		}
650 		imported->imp_sid = sid;
651 		if (idx >= 0)
652 		{
653 		    imported->imp_type = type;
654 		    imported->imp_var_vals_idx = idx;
655 		}
656 		else
657 		{
658 		    imported->imp_type = ufunc->uf_func_type;
659 		    imported->imp_funcname = ufunc->uf_name;
660 		}
661 	    }
662 	}
663     }
664 erret:
665     ga_clear_strings(&names);
666     ga_clear_strings(&as_names);
667     return cmd_end;
668 }
669 
670 /*
671  * Declare a script-local variable without init: "let var: type".
672  * "const" is an error since the value is missing.
673  * Returns a pointer to after the type.
674  */
675     char_u *
676 vim9_declare_scriptvar(exarg_T *eap, char_u *arg)
677 {
678     char_u	    *p;
679     char_u	    *name;
680     scriptitem_T    *si = SCRIPT_ITEM(current_sctx.sc_sid);
681     type_T	    *type;
682     typval_T	    init_tv;
683 
684     if (eap->cmdidx == CMD_final || eap->cmdidx == CMD_const)
685     {
686 	if (eap->cmdidx == CMD_final)
687 	    emsg(_(e_final_requires_a_value));
688 	else
689 	    emsg(_(e_const_requires_a_value));
690 	return arg + STRLEN(arg);
691     }
692 
693     // Check for valid starting character.
694     if (!eval_isnamec1(*arg))
695     {
696 	semsg(_(e_invarg2), arg);
697 	return arg + STRLEN(arg);
698     }
699 
700     for (p = arg + 1; *p != NUL && eval_isnamec(*p); MB_PTR_ADV(p))
701 	if (*p == ':' && (VIM_ISWHITE(p[1]) || p != arg + 1))
702 	    break;
703 
704     if (*p != ':')
705     {
706 	emsg(_(e_type_or_initialization_required));
707 	return arg + STRLEN(arg);
708     }
709     if (!VIM_ISWHITE(p[1]))
710     {
711 	semsg(_(e_white_space_required_after_str_str), ":", p);
712 	return arg + STRLEN(arg);
713     }
714     name = vim_strnsave(arg, p - arg);
715 
716     // parse type, check for reserved name
717     p = skipwhite(p + 1);
718     type = parse_type(&p, &si->sn_type_list, TRUE);
719     if (type == NULL || check_reserved_name(name) == FAIL)
720     {
721 	vim_free(name);
722 	return p;
723     }
724 
725     // Create the variable with 0/NULL value.
726     CLEAR_FIELD(init_tv);
727     if (type->tt_type == VAR_ANY)
728 	// A variable of type "any" is not possible, just use zero instead
729 	init_tv.v_type = VAR_NUMBER;
730     else
731 	init_tv.v_type = type->tt_type;
732     set_var_const(name, type, &init_tv, FALSE, 0, 0);
733 
734     vim_free(name);
735     return p;
736 }
737 
738 /*
739  * Vim9 part of adding a script variable: add it to sn_all_vars (lookup by name
740  * with a hashtable) and sn_var_vals (lookup by index).
741  * When "create" is TRUE this is a new variable, otherwise find and update an
742  * existing variable.
743  * "flags" can have ASSIGN_FINAL or ASSIGN_CONST.
744  * When "*type" is NULL use "tv" for the type and update "*type".  If
745  * "do_member" is TRUE also use the member type, otherwise use "any".
746  */
747     void
748 update_vim9_script_var(
749 	int	    create,
750 	dictitem_T  *di,
751 	int	    flags,
752 	typval_T    *tv,
753 	type_T	    **type,
754 	int	    do_member)
755 {
756     scriptitem_T    *si = SCRIPT_ITEM(current_sctx.sc_sid);
757     hashitem_T	    *hi;
758     svar_T	    *sv;
759 
760     if (create)
761     {
762 	sallvar_T	    *newsav;
763 
764 	// Store a pointer to the typval_T, so that it can be found by index
765 	// instead of using a hastab lookup.
766 	if (ga_grow(&si->sn_var_vals, 1) == FAIL)
767 	    return;
768 
769 	sv = ((svar_T *)si->sn_var_vals.ga_data) + si->sn_var_vals.ga_len;
770 	newsav = (sallvar_T *)alloc_clear(
771 				       sizeof(sallvar_T) + STRLEN(di->di_key));
772 	if (newsav == NULL)
773 	    return;
774 
775 	sv->sv_tv = &di->di_tv;
776 	sv->sv_const = (flags & ASSIGN_FINAL) ? ASSIGN_FINAL
777 				   : (flags & ASSIGN_CONST) ? ASSIGN_CONST : 0;
778 	sv->sv_export = is_export;
779 	newsav->sav_var_vals_idx = si->sn_var_vals.ga_len;
780 	++si->sn_var_vals.ga_len;
781 	STRCPY(&newsav->sav_key, di->di_key);
782 	sv->sv_name = newsav->sav_key;
783 	newsav->sav_di = di;
784 	newsav->sav_block_id = si->sn_current_block_id;
785 
786 	hi = hash_find(&si->sn_all_vars.dv_hashtab, newsav->sav_key);
787 	if (!HASHITEM_EMPTY(hi))
788 	{
789 	    sallvar_T *sav = HI2SAV(hi);
790 
791 	    // variable with this name exists in another block
792 	    while (sav->sav_next != NULL)
793 		sav = sav->sav_next;
794 	    sav->sav_next = newsav;
795 	}
796 	else
797 	    // new variable name
798 	    hash_add(&si->sn_all_vars.dv_hashtab, newsav->sav_key);
799     }
800     else
801     {
802 	sv = find_typval_in_script(&di->di_tv);
803     }
804     if (sv != NULL)
805     {
806 	if (*type == NULL)
807 	    *type = typval2type(tv, get_copyID(), &si->sn_type_list,
808 								    do_member);
809 	sv->sv_type = *type;
810     }
811 
812     // let ex_export() know the export worked.
813     is_export = FALSE;
814 }
815 
816 /*
817  * Hide a script variable when leaving a block.
818  * "idx" is de index in sn_var_vals.
819  * When "func_defined" is non-zero then a function was defined in this block,
820  * the variable may be accessed by it.  Otherwise the variable can be cleared.
821  */
822     void
823 hide_script_var(scriptitem_T *si, int idx, int func_defined)
824 {
825     svar_T	*sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
826     hashtab_T	*script_ht = get_script_local_ht();
827     hashtab_T	*all_ht = &si->sn_all_vars.dv_hashtab;
828     hashitem_T	*script_hi;
829     hashitem_T	*all_hi;
830 
831     // Remove a variable declared inside the block, if it still exists.
832     // If it was added in a nested block it will already have been removed.
833     // The typval is moved into the sallvar_T.
834     script_hi = hash_find(script_ht, sv->sv_name);
835     all_hi = hash_find(all_ht, sv->sv_name);
836     if (!HASHITEM_EMPTY(script_hi) && !HASHITEM_EMPTY(all_hi))
837     {
838 	dictitem_T	*di = HI2DI(script_hi);
839 	sallvar_T	*sav = HI2SAV(all_hi);
840 	sallvar_T	*sav_prev = NULL;
841 
842 	// There can be multiple entries with the same name in different
843 	// blocks, find the right one.
844 	while (sav != NULL && sav->sav_var_vals_idx != idx)
845 	{
846 	    sav_prev = sav;
847 	    sav = sav->sav_next;
848 	}
849 	if (sav != NULL)
850 	{
851 	    if (func_defined)
852 	    {
853 		// move the typval from the dictitem to the sallvar
854 		sav->sav_tv = di->di_tv;
855 		di->di_tv.v_type = VAR_UNKNOWN;
856 		sav->sav_flags = di->di_flags;
857 		sav->sav_di = NULL;
858 		sv->sv_tv = &sav->sav_tv;
859 	    }
860 	    else
861 	    {
862 		if (sav_prev == NULL)
863 		    hash_remove(all_ht, all_hi);
864 		else
865 		    sav_prev->sav_next = sav->sav_next;
866 		sv->sv_name = NULL;
867 		vim_free(sav);
868 	    }
869 	    delete_var(script_ht, script_hi);
870 	}
871     }
872 }
873 
874 /*
875  * Free the script variables from "sn_all_vars".
876  */
877     void
878 free_all_script_vars(scriptitem_T *si)
879 {
880     int		todo;
881     hashtab_T	*ht = &si->sn_all_vars.dv_hashtab;
882     hashitem_T	*hi;
883     sallvar_T	*sav;
884     sallvar_T	*sav_next;
885 
886     hash_lock(ht);
887     todo = (int)ht->ht_used;
888     for (hi = ht->ht_array; todo > 0; ++hi)
889     {
890 	if (!HASHITEM_EMPTY(hi))
891 	{
892 	    --todo;
893 
894 	    // Free the variable.  Don't remove it from the hashtab, ht_array
895 	    // might change then.  hash_clear() takes care of it later.
896 	    sav = HI2SAV(hi);
897 	    while (sav != NULL)
898 	    {
899 		sav_next = sav->sav_next;
900 		if (sav->sav_di == NULL)
901 		    clear_tv(&sav->sav_tv);
902 		vim_free(sav);
903 		sav = sav_next;
904 	    }
905 	}
906     }
907     hash_clear(ht);
908     hash_init(ht);
909 
910     ga_clear(&si->sn_var_vals);
911 
912     // existing commands using script variable indexes are no longer valid
913     si->sn_script_seq = current_sctx.sc_seq;
914 }
915 
916 /*
917  * Find the script-local variable that links to "dest".
918  * Returns NULL if not found.
919  */
920     svar_T *
921 find_typval_in_script(typval_T *dest)
922 {
923     scriptitem_T    *si = SCRIPT_ITEM(current_sctx.sc_sid);
924     int		    idx;
925 
926     if (si->sn_version != SCRIPT_VERSION_VIM9)
927 	// legacy script doesn't store variable types
928 	return NULL;
929 
930     // Find the svar_T in sn_var_vals.
931     for (idx = 0; idx < si->sn_var_vals.ga_len; ++idx)
932     {
933 	svar_T    *sv = ((svar_T *)si->sn_var_vals.ga_data) + idx;
934 
935 	// If "sv_name" is NULL the variable was hidden when leaving a block,
936 	// don't check "sv_tv" then, it might be used for another variable now.
937 	if (sv->sv_name != NULL && sv->sv_tv == dest)
938 	    return sv;
939     }
940     iemsg("find_typval_in_script(): not found");
941     return NULL;
942 }
943 
944 /*
945  * Check if the type of script variable "dest" allows assigning "value".
946  * If needed convert "value" to a bool.
947  */
948     int
949 check_script_var_type(
950 	typval_T    *dest,
951 	typval_T    *value,
952 	char_u	    *name,
953 	where_T	    where)
954 {
955     svar_T  *sv = find_typval_in_script(dest);
956     int	    ret;
957 
958     if (sv != NULL)
959     {
960 	if (sv->sv_const != 0)
961 	{
962 	    semsg(_(e_readonlyvar), name);
963 	    return FAIL;
964 	}
965 	ret = check_typval_type(sv->sv_type, value, where);
966 	if (ret == OK && need_convert_to_bool(sv->sv_type, value))
967 	{
968 	    int	val = tv2bool(value);
969 
970 	    clear_tv(value);
971 	    value->v_type = VAR_BOOL;
972 	    value->v_lock = 0;
973 	    value->vval.v_number = val ? VVAL_TRUE : VVAL_FALSE;
974 	}
975 	return ret;
976     }
977 
978     return OK; // not really
979 }
980 
981 // words that cannot be used as a variable
982 static char *reserved[] = {
983     "true",
984     "false",
985     "null",
986     "this",
987     NULL
988 };
989 
990     int
991 check_reserved_name(char_u *name)
992 {
993     int idx;
994 
995     for (idx = 0; reserved[idx] != NULL; ++idx)
996 	if (STRCMP(reserved[idx], name) == 0)
997 	{
998 	    semsg(_(e_cannot_use_reserved_name), name);
999 	    return FAIL;
1000 	}
1001     return OK;
1002 }
1003 
1004 #endif // FEAT_EVAL
1005