xref: /vim-8.2.3635/src/ex_eval.c (revision f3caeb63)
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  * ex_eval.c: functions for Ex command line for the +eval feature.
12  */
13 
14 #include "vim.h"
15 
16 #if defined(FEAT_EVAL) || defined(PROTO)
17 
18 static char	*get_end_emsg(cstack_T *cstack);
19 
20 /*
21  * Exception handling terms:
22  *
23  *	:try		":try" command		\
24  *	    ...		try block		|
25  *	:catch RE	":catch" command	|
26  *	    ...		catch clause		|- try conditional
27  *	:finally	":finally" command	|
28  *	    ...		finally clause		|
29  *	:endtry		":endtry" command	/
30  *
31  * The try conditional may have any number of catch clauses and at most one
32  * finally clause.  A ":throw" command can be inside the try block, a catch
33  * clause, the finally clause, or in a function called or script sourced from
34  * there or even outside the try conditional.  Try conditionals may be nested.
35  */
36 
37 /*
38  * Configuration whether an exception is thrown on error or interrupt.  When
39  * the preprocessor macros below evaluate to FALSE, an error (did_emsg) or
40  * interrupt (got_int) under an active try conditional terminates the script
41  * after the non-active finally clauses of all active try conditionals have been
42  * executed.  Otherwise, errors and/or interrupts are converted into catchable
43  * exceptions (did_throw additionally set), which terminate the script only if
44  * not caught.  For user exceptions, only did_throw is set.  (Note: got_int can
45  * be set asynchronously afterwards by a SIGINT, so did_throw && got_int is not
46  * a reliant test that the exception currently being thrown is an interrupt
47  * exception.  Similarly, did_emsg can be set afterwards on an error in an
48  * (unskipped) conditional command inside an inactive conditional, so did_throw
49  * && did_emsg is not a reliant test that the exception currently being thrown
50  * is an error exception.)  -  The macros can be defined as expressions checking
51  * for a variable that is allowed to be changed during execution of a script.
52  */
53 #if 0
54 // Expressions used for testing during the development phase.
55 # define THROW_ON_ERROR		(!eval_to_number("$VIMNOERRTHROW"))
56 # define THROW_ON_INTERRUPT	(!eval_to_number("$VIMNOINTTHROW"))
57 # define THROW_TEST
58 #else
59 // Values used for the Vim release.
60 # define THROW_ON_ERROR		TRUE
61 # define THROW_ON_ERROR_TRUE
62 # define THROW_ON_INTERRUPT	TRUE
63 # define THROW_ON_INTERRUPT_TRUE
64 #endif
65 
66 /*
67  * When several errors appear in a row, setting "force_abort" is delayed until
68  * the failing command returned.  "cause_abort" is set to TRUE meanwhile, in
69  * order to indicate that situation.  This is useful when "force_abort" was set
70  * during execution of a function call from an expression: the aborting of the
71  * expression evaluation is done without producing any error messages, but all
72  * error messages on parsing errors during the expression evaluation are given
73  * (even if a try conditional is active).
74  */
75 static int cause_abort = FALSE;
76 
77 /*
78  * Return TRUE when immediately aborting on error, or when an interrupt
79  * occurred or an exception was thrown but not caught.  Use for ":{range}call"
80  * to check whether an aborted function that does not handle a range itself
81  * should be called again for the next line in the range.  Also used for
82  * cancelling expression evaluation after a function call caused an immediate
83  * abort.  Note that the first emsg() call temporarily resets "force_abort"
84  * until the throw point for error messages has been reached.  That is, during
85  * cancellation of an expression evaluation after an aborting function call or
86  * due to a parsing error, aborting() always returns the same value.
87  * "got_int" is also set by calling interrupt().
88  */
89     int
90 aborting(void)
91 {
92     return (did_emsg && force_abort) || got_int || did_throw;
93 }
94 
95 /*
96  * The value of "force_abort" is temporarily reset by the first emsg() call
97  * during an expression evaluation, and "cause_abort" is used instead.  It might
98  * be necessary to restore "force_abort" even before the throw point for the
99  * error message has been reached.  update_force_abort() should be called then.
100  */
101     void
102 update_force_abort(void)
103 {
104     if (cause_abort)
105 	force_abort = TRUE;
106 }
107 
108 /*
109  * Return TRUE if a command with a subcommand resulting in "retcode" should
110  * abort the script processing.  Can be used to suppress an autocommand after
111  * execution of a failing subcommand as long as the error message has not been
112  * displayed and actually caused the abortion.
113  */
114     int
115 should_abort(int retcode)
116 {
117     return ((retcode == FAIL && trylevel != 0 && !emsg_silent) || aborting());
118 }
119 
120 /*
121  * Return TRUE if a function with the "abort" flag should not be considered
122  * ended on an error.  This means that parsing commands is continued in order
123  * to find finally clauses to be executed, and that some errors in skipped
124  * commands are still reported.
125  */
126     int
127 aborted_in_try(void)
128 {
129     // This function is only called after an error.  In this case, "force_abort"
130     // determines whether searching for finally clauses is necessary.
131     return force_abort;
132 }
133 
134 /*
135  * cause_errthrow(): Cause a throw of an error exception if appropriate.
136  * Return TRUE if the error message should not be displayed by emsg().
137  * Sets "ignore", if the emsg() call should be ignored completely.
138  *
139  * When several messages appear in the same command, the first is usually the
140  * most specific one and used as the exception value.  The "severe" flag can be
141  * set to TRUE, if a later but severer message should be used instead.
142  */
143     int
144 cause_errthrow(
145     char_u	*mesg,
146     int		severe,
147     int		*ignore)
148 {
149     msglist_T	*elem;
150     msglist_T	**plist;
151 
152     /*
153      * Do nothing when displaying the interrupt message or reporting an
154      * uncaught exception (which has already been discarded then) at the top
155      * level.  Also when no exception can be thrown.  The message will be
156      * displayed by emsg().
157      */
158     if (suppress_errthrow)
159 	return FALSE;
160 
161     /*
162      * If emsg() has not been called previously, temporarily reset
163      * "force_abort" until the throw point for error messages has been
164      * reached.  This ensures that aborting() returns the same value for all
165      * errors that appear in the same command.  This means particularly that
166      * for parsing errors during expression evaluation emsg() will be called
167      * multiply, even when the expression is evaluated from a finally clause
168      * that was activated due to an aborting error, interrupt, or exception.
169      */
170     if (!did_emsg)
171     {
172 	cause_abort = force_abort;
173 	force_abort = FALSE;
174     }
175 
176     /*
177      * If no try conditional is active and no exception is being thrown and
178      * there has not been an error in a try conditional or a throw so far, do
179      * nothing (for compatibility of non-EH scripts).  The message will then
180      * be displayed by emsg().  When ":silent!" was used and we are not
181      * currently throwing an exception, do nothing.  The message text will
182      * then be stored to v:errmsg by emsg() without displaying it.
183      */
184     if (((trylevel == 0 && !cause_abort) || emsg_silent) && !did_throw)
185 	return FALSE;
186 
187     /*
188      * Ignore an interrupt message when inside a try conditional or when an
189      * exception is being thrown or when an error in a try conditional or
190      * throw has been detected previously.  This is important in order that an
191      * interrupt exception is catchable by the innermost try conditional and
192      * not replaced by an interrupt message error exception.
193      */
194     if (mesg == (char_u *)_(e_interr))
195     {
196 	*ignore = TRUE;
197 	return TRUE;
198     }
199 
200     /*
201      * Ensure that all commands in nested function calls and sourced files
202      * are aborted immediately.
203      */
204     cause_abort = TRUE;
205 
206     /*
207      * When an exception is being thrown, some commands (like conditionals) are
208      * not skipped.  Errors in those commands may affect what of the subsequent
209      * commands are regarded part of catch and finally clauses.  Catching the
210      * exception would then cause execution of commands not intended by the
211      * user, who wouldn't even get aware of the problem.  Therefor, discard the
212      * exception currently being thrown to prevent it from being caught.  Just
213      * execute finally clauses and terminate.
214      */
215     if (did_throw)
216     {
217 	// When discarding an interrupt exception, reset got_int to prevent the
218 	// same interrupt being converted to an exception again and discarding
219 	// the error exception we are about to throw here.
220 	if (current_exception->type == ET_INTERRUPT)
221 	    got_int = FALSE;
222 	discard_current_exception();
223     }
224 
225 #ifdef THROW_TEST
226     if (!THROW_ON_ERROR)
227     {
228 	/*
229 	 * Print error message immediately without searching for a matching
230 	 * catch clause; just finally clauses are executed before the script
231 	 * is terminated.
232 	 */
233 	return FALSE;
234     }
235     else
236 #endif
237     {
238 	/*
239 	 * Prepare the throw of an error exception, so that everything will
240 	 * be aborted (except for executing finally clauses), until the error
241 	 * exception is caught; if still uncaught at the top level, the error
242 	 * message will be displayed and the script processing terminated
243 	 * then.  -  This function has no access to the conditional stack.
244 	 * Thus, the actual throw is made after the failing command has
245 	 * returned.  -  Throw only the first of several errors in a row, except
246 	 * a severe error is following.
247 	 */
248 	if (msg_list != NULL)
249 	{
250 	    plist = msg_list;
251 	    while (*plist != NULL)
252 		plist = &(*plist)->next;
253 
254 	    elem = ALLOC_CLEAR_ONE(msglist_T);
255 	    if (elem == NULL)
256 	    {
257 		suppress_errthrow = TRUE;
258 		emsg(_(e_outofmem));
259 	    }
260 	    else
261 	    {
262 		elem->msg = (char *)vim_strsave(mesg);
263 		if (elem->msg == NULL)
264 		{
265 		    vim_free(elem);
266 		    suppress_errthrow = TRUE;
267 		    emsg(_(e_outofmem));
268 		}
269 		else
270 		{
271 		    elem->next = NULL;
272 		    elem->throw_msg = NULL;
273 		    *plist = elem;
274 		    if (plist == msg_list || severe)
275 		    {
276 			char	    *tmsg;
277 
278 			// Skip the extra "Vim " prefix for message "E458".
279 			tmsg = elem->msg;
280 			if (STRNCMP(tmsg, "Vim E", 5) == 0
281 				&& VIM_ISDIGIT(tmsg[5])
282 				&& VIM_ISDIGIT(tmsg[6])
283 				&& VIM_ISDIGIT(tmsg[7])
284 				&& tmsg[8] == ':'
285 				&& tmsg[9] == ' ')
286 			    (*msg_list)->throw_msg = &tmsg[4];
287 			else
288 			    (*msg_list)->throw_msg = tmsg;
289 		    }
290 
291 		    // Get the source name and lnum now, it may change before
292 		    // reaching do_errthrow().
293 		    elem->sfile = estack_sfile(ESTACK_NONE);
294 		    elem->slnum = SOURCING_LNUM;
295 		    elem->msg_compiling = estack_compiling;
296 		}
297 	    }
298 	}
299 	return TRUE;
300     }
301 }
302 
303 /*
304  * Free a "msg_list" and the messages it contains.
305  */
306     static void
307 free_msglist(msglist_T *l)
308 {
309     msglist_T  *messages, *next;
310 
311     messages = l;
312     while (messages != NULL)
313     {
314 	next = messages->next;
315 	vim_free(messages->msg);
316 	vim_free(messages->sfile);
317 	vim_free(messages);
318 	messages = next;
319     }
320 }
321 
322 /*
323  * Free global "*msg_list" and the messages it contains, then set "*msg_list"
324  * to NULL.
325  */
326     void
327 free_global_msglist(void)
328 {
329     free_msglist(*msg_list);
330     *msg_list = NULL;
331 }
332 
333 /*
334  * Throw the message specified in the call to cause_errthrow() above as an
335  * error exception.  If cstack is NULL, postpone the throw until do_cmdline()
336  * has returned (see do_one_cmd()).
337  */
338     void
339 do_errthrow(cstack_T *cstack, char_u *cmdname)
340 {
341     /*
342      * Ensure that all commands in nested function calls and sourced files
343      * are aborted immediately.
344      */
345     if (cause_abort)
346     {
347 	cause_abort = FALSE;
348 	force_abort = TRUE;
349     }
350 
351     // If no exception is to be thrown or the conversion should be done after
352     // returning to a previous invocation of do_one_cmd(), do nothing.
353     if (msg_list == NULL || *msg_list == NULL)
354 	return;
355 
356     if (throw_exception(*msg_list, ET_ERROR, cmdname) == FAIL)
357 	free_msglist(*msg_list);
358     else
359     {
360 	if (cstack != NULL)
361 	    do_throw(cstack);
362 	else
363 	    need_rethrow = TRUE;
364     }
365     *msg_list = NULL;
366 }
367 
368 /*
369  * do_intthrow(): Replace the current exception by an interrupt or interrupt
370  * exception if appropriate.  Return TRUE if the current exception is discarded,
371  * FALSE otherwise.
372  */
373     int
374 do_intthrow(cstack_T *cstack)
375 {
376     /*
377      * If no interrupt occurred or no try conditional is active and no exception
378      * is being thrown, do nothing (for compatibility of non-EH scripts).
379      */
380     if (!got_int || (trylevel == 0 && !did_throw))
381 	return FALSE;
382 
383 #ifdef THROW_TEST	// avoid warning for condition always true
384     if (!THROW_ON_INTERRUPT)
385     {
386 	/*
387 	 * The interrupt aborts everything except for executing finally clauses.
388 	 * Discard any user or error or interrupt exception currently being
389 	 * thrown.
390 	 */
391 	if (did_throw)
392 	    discard_current_exception();
393     }
394     else
395 #endif
396     {
397 	/*
398 	 * Throw an interrupt exception, so that everything will be aborted
399 	 * (except for executing finally clauses), until the interrupt exception
400 	 * is caught; if still uncaught at the top level, the script processing
401 	 * will be terminated then.  -  If an interrupt exception is already
402 	 * being thrown, do nothing.
403 	 *
404 	 */
405 	if (did_throw)
406 	{
407 	    if (current_exception->type == ET_INTERRUPT)
408 		return FALSE;
409 
410 	    // An interrupt exception replaces any user or error exception.
411 	    discard_current_exception();
412 	}
413 	if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) != FAIL)
414 	    do_throw(cstack);
415     }
416 
417     return TRUE;
418 }
419 
420 /*
421  * Get an exception message that is to be stored in current_exception->value.
422  */
423     char *
424 get_exception_string(
425     void	*value,
426     except_type_T type,
427     char_u	*cmdname,
428     int		*should_free)
429 {
430     char	*ret;
431     char	*mesg;
432     int		cmdlen;
433     char	*p, *val;
434 
435     if (type == ET_ERROR)
436     {
437 	*should_free = TRUE;
438 	mesg = ((msglist_T *)value)->throw_msg;
439 	if (cmdname != NULL && *cmdname != NUL)
440 	{
441 	    cmdlen = (int)STRLEN(cmdname);
442 	    ret = (char *)vim_strnsave((char_u *)"Vim(",
443 						4 + cmdlen + 2 + STRLEN(mesg));
444 	    if (ret == NULL)
445 		return ret;
446 	    STRCPY(&ret[4], cmdname);
447 	    STRCPY(&ret[4 + cmdlen], "):");
448 	    val = ret + 4 + cmdlen + 2;
449 	}
450 	else
451 	{
452 	    ret = (char *)vim_strnsave((char_u *)"Vim:", 4 + STRLEN(mesg));
453 	    if (ret == NULL)
454 		return ret;
455 	    val = ret + 4;
456 	}
457 
458 	// msg_add_fname may have been used to prefix the message with a file
459 	// name in quotes.  In the exception value, put the file name in
460 	// parentheses and move it to the end.
461 	for (p = mesg; ; p++)
462 	{
463 	    if (*p == NUL
464 		    || (*p == 'E'
465 			&& VIM_ISDIGIT(p[1])
466 			&& (p[2] == ':'
467 			    || (VIM_ISDIGIT(p[2])
468 				&& (p[3] == ':'
469 				    || (VIM_ISDIGIT(p[3])
470 					&& p[4] == ':'))))))
471 	    {
472 		if (*p == NUL || p == mesg)
473 		    STRCAT(val, mesg);  // 'E123' missing or at beginning
474 		else
475 		{
476 		    // '"filename" E123: message text'
477 		    if (mesg[0] != '"' || p-2 < &mesg[1] ||
478 			    p[-2] != '"' || p[-1] != ' ')
479 			// "E123:" is part of the file name.
480 			continue;
481 
482 		    STRCAT(val, p);
483 		    p[-2] = NUL;
484 		    sprintf((char *)(val + STRLEN(p)), " (%s)", &mesg[1]);
485 		    p[-2] = '"';
486 		}
487 		break;
488 	    }
489 	}
490     }
491     else
492     {
493 	*should_free = FALSE;
494 	ret = value;
495     }
496 
497     return ret;
498 }
499 
500 
501 /*
502  * Throw a new exception.  Return FAIL when out of memory or it was tried to
503  * throw an illegal user exception.  "value" is the exception string for a
504  * user or interrupt exception, or points to a message list in case of an
505  * error exception.
506  */
507     int
508 throw_exception(void *value, except_type_T type, char_u *cmdname)
509 {
510     except_T	*excp;
511     int		should_free;
512 
513     /*
514      * Disallow faking Interrupt or error exceptions as user exceptions.  They
515      * would be treated differently from real interrupt or error exceptions
516      * when no active try block is found, see do_cmdline().
517      */
518     if (type == ET_USER)
519     {
520 	if (STRNCMP((char_u *)value, "Vim", 3) == 0
521 		&& (((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':'
522 		    || ((char_u *)value)[3] == '('))
523 	{
524 	    emsg(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
525 	    goto fail;
526 	}
527     }
528 
529     excp = ALLOC_ONE(except_T);
530     if (excp == NULL)
531 	goto nomem;
532 
533     if (type == ET_ERROR)
534 	// Store the original message and prefix the exception value with
535 	// "Vim:" or, if a command name is given, "Vim(cmdname):".
536 	excp->messages = (msglist_T *)value;
537 
538     excp->value = get_exception_string(value, type, cmdname, &should_free);
539     if (excp->value == NULL && should_free)
540 	goto nomem;
541 
542     excp->type = type;
543     if (type == ET_ERROR && ((msglist_T *)value)->sfile != NULL)
544     {
545 	msglist_T *entry = (msglist_T *)value;
546 
547 	excp->throw_name = entry->sfile;
548 	entry->sfile = NULL;
549 	excp->throw_lnum = entry->slnum;
550     }
551     else
552     {
553 	excp->throw_name = estack_sfile(ESTACK_NONE);
554 	if (excp->throw_name == NULL)
555 	    excp->throw_name = vim_strsave((char_u *)"");
556 	if (excp->throw_name == NULL)
557 	{
558 	    if (should_free)
559 		vim_free(excp->value);
560 	    goto nomem;
561 	}
562 	excp->throw_lnum = SOURCING_LNUM;
563     }
564 
565     if (p_verbose >= 13 || debug_break_level > 0)
566     {
567 	int	save_msg_silent = msg_silent;
568 
569 	if (debug_break_level > 0)
570 	    msg_silent = FALSE;		// display messages
571 	else
572 	    verbose_enter();
573 	++no_wait_return;
574 	if (debug_break_level > 0 || *p_vfile == NUL)
575 	    msg_scroll = TRUE;	    // always scroll up, don't overwrite
576 
577 	smsg(_("Exception thrown: %s"), excp->value);
578 	msg_puts("\n");   // don't overwrite this either
579 
580 	if (debug_break_level > 0 || *p_vfile == NUL)
581 	    cmdline_row = msg_row;
582 	--no_wait_return;
583 	if (debug_break_level > 0)
584 	    msg_silent = save_msg_silent;
585 	else
586 	    verbose_leave();
587     }
588 
589     current_exception = excp;
590     return OK;
591 
592 nomem:
593     vim_free(excp);
594     suppress_errthrow = TRUE;
595     emsg(_(e_outofmem));
596 fail:
597     current_exception = NULL;
598     return FAIL;
599 }
600 
601 /*
602  * Discard an exception.  "was_finished" is set when the exception has been
603  * caught and the catch clause has been ended normally.
604  */
605     static void
606 discard_exception(except_T *excp, int was_finished)
607 {
608     char_u		*saved_IObuff;
609 
610     if (current_exception == excp)
611 	current_exception = NULL;
612     if (excp == NULL)
613     {
614 	internal_error("discard_exception()");
615 	return;
616     }
617 
618     if (p_verbose >= 13 || debug_break_level > 0)
619     {
620 	int	save_msg_silent = msg_silent;
621 
622 	saved_IObuff = vim_strsave(IObuff);
623 	if (debug_break_level > 0)
624 	    msg_silent = FALSE;		// display messages
625 	else
626 	    verbose_enter();
627 	++no_wait_return;
628 	if (debug_break_level > 0 || *p_vfile == NUL)
629 	    msg_scroll = TRUE;	    // always scroll up, don't overwrite
630 	smsg(was_finished
631 		    ? _("Exception finished: %s")
632 		    : _("Exception discarded: %s"),
633 		excp->value);
634 	msg_puts("\n");   // don't overwrite this either
635 	if (debug_break_level > 0 || *p_vfile == NUL)
636 	    cmdline_row = msg_row;
637 	--no_wait_return;
638 	if (debug_break_level > 0)
639 	    msg_silent = save_msg_silent;
640 	else
641 	    verbose_leave();
642 	STRCPY(IObuff, saved_IObuff);
643 	vim_free(saved_IObuff);
644     }
645     if (excp->type != ET_INTERRUPT)
646 	vim_free(excp->value);
647     if (excp->type == ET_ERROR)
648 	free_msglist(excp->messages);
649     vim_free(excp->throw_name);
650     vim_free(excp);
651 }
652 
653 /*
654  * Discard the exception currently being thrown.
655  */
656     void
657 discard_current_exception(void)
658 {
659     if (current_exception != NULL)
660 	discard_exception(current_exception, FALSE);
661     did_throw = FALSE;
662     need_rethrow = FALSE;
663 }
664 
665 /*
666  * Put an exception on the caught stack.
667  */
668     void
669 catch_exception(except_T *excp)
670 {
671     excp->caught = caught_stack;
672     caught_stack = excp;
673     set_vim_var_string(VV_EXCEPTION, (char_u *)excp->value, -1);
674     if (*excp->throw_name != NUL)
675     {
676 	if (excp->throw_lnum != 0)
677 	    vim_snprintf((char *)IObuff, IOSIZE, _("%s, line %ld"),
678 				    excp->throw_name, (long)excp->throw_lnum);
679 	else
680 	    vim_snprintf((char *)IObuff, IOSIZE, "%s", excp->throw_name);
681 	set_vim_var_string(VV_THROWPOINT, IObuff, -1);
682     }
683     else
684 	// throw_name not set on an exception from a command that was typed.
685 	set_vim_var_string(VV_THROWPOINT, NULL, -1);
686 
687     if (p_verbose >= 13 || debug_break_level > 0)
688     {
689 	int	save_msg_silent = msg_silent;
690 
691 	if (debug_break_level > 0)
692 	    msg_silent = FALSE;		// display messages
693 	else
694 	    verbose_enter();
695 	++no_wait_return;
696 	if (debug_break_level > 0 || *p_vfile == NUL)
697 	    msg_scroll = TRUE;	    // always scroll up, don't overwrite
698 
699 	smsg(_("Exception caught: %s"), excp->value);
700 	msg_puts("\n");   // don't overwrite this either
701 
702 	if (debug_break_level > 0 || *p_vfile == NUL)
703 	    cmdline_row = msg_row;
704 	--no_wait_return;
705 	if (debug_break_level > 0)
706 	    msg_silent = save_msg_silent;
707 	else
708 	    verbose_leave();
709     }
710 }
711 
712 /*
713  * Remove an exception from the caught stack.
714  */
715     static void
716 finish_exception(except_T *excp)
717 {
718     if (excp != caught_stack)
719 	internal_error("finish_exception()");
720     caught_stack = caught_stack->caught;
721     if (caught_stack != NULL)
722     {
723 	set_vim_var_string(VV_EXCEPTION, (char_u *)caught_stack->value, -1);
724 	if (*caught_stack->throw_name != NUL)
725 	{
726 	    if (caught_stack->throw_lnum != 0)
727 		vim_snprintf((char *)IObuff, IOSIZE,
728 			_("%s, line %ld"), caught_stack->throw_name,
729 			(long)caught_stack->throw_lnum);
730 	    else
731 		vim_snprintf((char *)IObuff, IOSIZE, "%s",
732 						    caught_stack->throw_name);
733 	    set_vim_var_string(VV_THROWPOINT, IObuff, -1);
734 	}
735 	else
736 	    // throw_name not set on an exception from a command that was
737 	    // typed.
738 	    set_vim_var_string(VV_THROWPOINT, NULL, -1);
739     }
740     else
741     {
742 	set_vim_var_string(VV_EXCEPTION, NULL, -1);
743 	set_vim_var_string(VV_THROWPOINT, NULL, -1);
744     }
745 
746     // Discard the exception, but use the finish message for 'verbose'.
747     discard_exception(excp, TRUE);
748 }
749 
750 /*
751  * Flags specifying the message displayed by report_pending.
752  */
753 #define RP_MAKE		0
754 #define RP_RESUME	1
755 #define RP_DISCARD	2
756 
757 /*
758  * Report information about something pending in a finally clause if required by
759  * the 'verbose' option or when debugging.  "action" tells whether something is
760  * made pending or something pending is resumed or discarded.  "pending" tells
761  * what is pending.  "value" specifies the return value for a pending ":return"
762  * or the exception value for a pending exception.
763  */
764     static void
765 report_pending(int action, int pending, void *value)
766 {
767     char	*mesg;
768     char	*s;
769     int		save_msg_silent;
770 
771 
772     switch (action)
773     {
774 	case RP_MAKE:
775 	    mesg = _("%s made pending");
776 	    break;
777 	case RP_RESUME:
778 	    mesg = _("%s resumed");
779 	    break;
780 	// case RP_DISCARD:
781 	default:
782 	    mesg = _("%s discarded");
783 	    break;
784     }
785 
786     switch (pending)
787     {
788 	case CSTP_NONE:
789 	    return;
790 
791 	case CSTP_CONTINUE:
792 	    s = ":continue";
793 	    break;
794 	case CSTP_BREAK:
795 	    s = ":break";
796 	    break;
797 	case CSTP_FINISH:
798 	    s = ":finish";
799 	    break;
800 	case CSTP_RETURN:
801 	    // ":return" command producing value, allocated
802 	    s = (char *)get_return_cmd(value);
803 	    break;
804 
805 	default:
806 	    if (pending & CSTP_THROW)
807 	    {
808 		vim_snprintf((char *)IObuff, IOSIZE, mesg, _("Exception"));
809 		mesg = (char *)vim_strnsave(IObuff, STRLEN(IObuff) + 4);
810 		STRCAT(mesg, ": %s");
811 		s = (char *)((except_T *)value)->value;
812 	    }
813 	    else if ((pending & CSTP_ERROR) && (pending & CSTP_INTERRUPT))
814 		s = _("Error and interrupt");
815 	    else if (pending & CSTP_ERROR)
816 		s = _("Error");
817 	    else // if (pending & CSTP_INTERRUPT)
818 		s = _("Interrupt");
819     }
820 
821     save_msg_silent = msg_silent;
822     if (debug_break_level > 0)
823 	msg_silent = FALSE;	// display messages
824     ++no_wait_return;
825     msg_scroll = TRUE;		// always scroll up, don't overwrite
826     smsg(mesg, s);
827     msg_puts("\n");   // don't overwrite this either
828     cmdline_row = msg_row;
829     --no_wait_return;
830     if (debug_break_level > 0)
831 	msg_silent = save_msg_silent;
832 
833     if (pending == CSTP_RETURN)
834 	vim_free(s);
835     else if (pending & CSTP_THROW)
836 	vim_free(mesg);
837 }
838 
839 /*
840  * If something is made pending in a finally clause, report it if required by
841  * the 'verbose' option or when debugging.
842  */
843     void
844 report_make_pending(int pending, void *value)
845 {
846     if (p_verbose >= 14 || debug_break_level > 0)
847     {
848 	if (debug_break_level <= 0)
849 	    verbose_enter();
850 	report_pending(RP_MAKE, pending, value);
851 	if (debug_break_level <= 0)
852 	    verbose_leave();
853     }
854 }
855 
856 /*
857  * If something pending in a finally clause is resumed at the ":endtry", report
858  * it if required by the 'verbose' option or when debugging.
859  */
860     static void
861 report_resume_pending(int pending, void *value)
862 {
863     if (p_verbose >= 14 || debug_break_level > 0)
864     {
865 	if (debug_break_level <= 0)
866 	    verbose_enter();
867 	report_pending(RP_RESUME, pending, value);
868 	if (debug_break_level <= 0)
869 	    verbose_leave();
870     }
871 }
872 
873 /*
874  * If something pending in a finally clause is discarded, report it if required
875  * by the 'verbose' option or when debugging.
876  */
877     static void
878 report_discard_pending(int pending, void *value)
879 {
880     if (p_verbose >= 14 || debug_break_level > 0)
881     {
882 	if (debug_break_level <= 0)
883 	    verbose_enter();
884 	report_pending(RP_DISCARD, pending, value);
885 	if (debug_break_level <= 0)
886 	    verbose_leave();
887     }
888 }
889 
890 
891 /*
892  * ":eval".
893  */
894     void
895 ex_eval(exarg_T *eap)
896 {
897     typval_T	tv;
898     evalarg_T	evalarg;
899 
900     fill_evalarg_from_eap(&evalarg, eap, eap->skip);
901 
902     if (eval0(eap->arg, &tv, eap, &evalarg) == OK)
903 	clear_tv(&tv);
904 
905     clear_evalarg(&evalarg, eap);
906 }
907 
908 /*
909  * Start a new scope/block.  Caller should have checked that cs_idx is not
910  * exceeding CSTACK_LEN.
911  */
912     static void
913 enter_block(cstack_T *cstack)
914 {
915     ++cstack->cs_idx;
916     if (in_vim9script() && current_sctx.sc_sid > 0)
917     {
918 	scriptitem_T *si = SCRIPT_ITEM(current_sctx.sc_sid);
919 
920 	cstack->cs_script_var_len[cstack->cs_idx] = si->sn_var_vals.ga_len;
921 	cstack->cs_block_id[cstack->cs_idx] = ++si->sn_last_block_id;
922 	si->sn_current_block_id = si->sn_last_block_id;
923     }
924     else
925     {
926 	// Just in case in_vim9script() does not return the same value when the
927 	// block ends.
928 	cstack->cs_script_var_len[cstack->cs_idx] = 0;
929 	cstack->cs_block_id[cstack->cs_idx] = 0;
930     }
931 }
932 
933     static void
934 leave_block(cstack_T *cstack)
935 {
936     if (in_vim9script() && SCRIPT_ID_VALID(current_sctx.sc_sid))
937     {
938 	scriptitem_T	*si = SCRIPT_ITEM(current_sctx.sc_sid);
939 	int		i;
940 	int		func_defined =
941 			       cstack->cs_flags[cstack->cs_idx] & CSF_FUNC_DEF;
942 
943 	for (i = cstack->cs_script_var_len[cstack->cs_idx];
944 					       i < si->sn_var_vals.ga_len; ++i)
945 	{
946 	    svar_T	*sv = ((svar_T *)si->sn_var_vals.ga_data) + i;
947 
948 	    // sv_name is set to NULL if it was already removed.  This happens
949 	    // when it was defined in an inner block and no functions were
950 	    // defined there.
951 	    if (sv->sv_name != NULL)
952 		// Remove a variable declared inside the block, if it still
953 		// exists, from sn_vars and move the value into sn_all_vars
954 		// if "func_defined" is non-zero.
955 		hide_script_var(si, i, func_defined);
956 	}
957 
958 	// TODO: is this needed?
959 	cstack->cs_script_var_len[cstack->cs_idx] = si->sn_var_vals.ga_len;
960 
961 	if (cstack->cs_idx == 0)
962 	    si->sn_current_block_id = 0;
963 	else
964 	    si->sn_current_block_id = cstack->cs_block_id[cstack->cs_idx - 1];
965     }
966     --cstack->cs_idx;
967 }
968 
969 /*
970  * ":if".
971  */
972     void
973 ex_if(exarg_T *eap)
974 {
975     int		error;
976     int		skip;
977     int		result;
978     cstack_T	*cstack = eap->cstack;
979 
980     if (cstack->cs_idx == CSTACK_LEN - 1)
981 	eap->errmsg = _("E579: :if nesting too deep");
982     else
983     {
984 	enter_block(cstack);
985 	cstack->cs_flags[cstack->cs_idx] = 0;
986 
987 	/*
988 	 * Don't do something after an error, interrupt, or throw, or when
989 	 * there is a surrounding conditional and it was not active.
990 	 */
991 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
992 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
993 
994 	result = eval_to_bool(eap->arg, &error, eap, skip);
995 
996 	if (!skip && !error)
997 	{
998 	    if (result)
999 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
1000 	}
1001 	else
1002 	    // set TRUE, so this conditional will never get active
1003 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1004     }
1005 }
1006 
1007 /*
1008  * ":endif".
1009  */
1010     void
1011 ex_endif(exarg_T *eap)
1012 {
1013     cstack_T	*cstack = eap->cstack;
1014 
1015     if (cmdmod_error())
1016 	return;
1017     did_endif = TRUE;
1018     if (cstack->cs_idx < 0
1019 	    || (cstack->cs_flags[cstack->cs_idx]
1020 				& (CSF_WHILE | CSF_FOR | CSF_TRY | CSF_BLOCK)))
1021 	eap->errmsg = _(e_endif_without_if);
1022     else
1023     {
1024 	/*
1025 	 * When debugging or a breakpoint was encountered, display the debug
1026 	 * prompt (if not already done).  This shows the user that an ":endif"
1027 	 * is executed when the ":if" or a previous ":elseif" was not TRUE.
1028 	 * Handle a ">quit" debug command as if an interrupt had occurred before
1029 	 * the ":endif".  That is, throw an interrupt exception if appropriate.
1030 	 * Doing this here prevents an exception for a parsing error being
1031 	 * discarded by throwing the interrupt exception later on.
1032 	 */
1033 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE)
1034 						    && dbg_check_skipped(eap))
1035 	    (void)do_intthrow(cstack);
1036 
1037 	leave_block(cstack);
1038     }
1039 }
1040 
1041 /*
1042  * ":else" and ":elseif".
1043  */
1044     void
1045 ex_else(exarg_T *eap)
1046 {
1047     int		error;
1048     int		skip;
1049     int		result;
1050     cstack_T	*cstack = eap->cstack;
1051 
1052     /*
1053      * Don't do something after an error, interrupt, or throw, or when there is
1054      * a surrounding conditional and it was not active.
1055      */
1056     skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1057 	    && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1058 
1059     if (cstack->cs_idx < 0
1060 	    || (cstack->cs_flags[cstack->cs_idx]
1061 				& (CSF_WHILE | CSF_FOR | CSF_TRY | CSF_BLOCK)))
1062     {
1063 	if (eap->cmdidx == CMD_else)
1064 	{
1065 	    eap->errmsg = _(e_else_without_if);
1066 	    return;
1067 	}
1068 	eap->errmsg = _(e_elseif_without_if);
1069 	skip = TRUE;
1070     }
1071     else if (cstack->cs_flags[cstack->cs_idx] & CSF_ELSE)
1072     {
1073 	if (eap->cmdidx == CMD_else)
1074 	{
1075 	    eap->errmsg = _("E583: multiple :else");
1076 	    return;
1077 	}
1078 	eap->errmsg = _("E584: :elseif after :else");
1079 	skip = TRUE;
1080     }
1081 
1082     // if skipping or the ":if" was TRUE, reset ACTIVE, otherwise set it
1083     if (skip || cstack->cs_flags[cstack->cs_idx] & CSF_TRUE)
1084     {
1085 	if (eap->errmsg == NULL)
1086 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1087 	skip = TRUE;	// don't evaluate an ":elseif"
1088     }
1089     else
1090 	cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE;
1091 
1092     /*
1093      * When debugging or a breakpoint was encountered, display the debug prompt
1094      * (if not already done).  This shows the user that an ":else" or ":elseif"
1095      * is executed when the ":if" or previous ":elseif" was not TRUE.  Handle
1096      * a ">quit" debug command as if an interrupt had occurred before the
1097      * ":else" or ":elseif".  That is, set "skip" and throw an interrupt
1098      * exception if appropriate.  Doing this here prevents that an exception
1099      * for a parsing errors is discarded when throwing the interrupt exception
1100      * later on.
1101      */
1102     if (!skip && dbg_check_skipped(eap) && got_int)
1103     {
1104 	(void)do_intthrow(cstack);
1105 	skip = TRUE;
1106     }
1107 
1108     if (eap->cmdidx == CMD_elseif)
1109     {
1110 	result = eval_to_bool(eap->arg, &error, eap, skip);
1111 
1112 	// When throwing error exceptions, we want to throw always the first
1113 	// of several errors in a row.  This is what actually happens when
1114 	// a conditional error was detected above and there is another failure
1115 	// when parsing the expression.  Since the skip flag is set in this
1116 	// case, the parsing error will be ignored by emsg().
1117 	if (!skip && !error)
1118 	{
1119 	    if (result)
1120 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
1121 	    else
1122 		cstack->cs_flags[cstack->cs_idx] = 0;
1123 	}
1124 	else if (eap->errmsg == NULL)
1125 	    // set TRUE, so this conditional will never get active
1126 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1127     }
1128     else
1129 	cstack->cs_flags[cstack->cs_idx] |= CSF_ELSE;
1130 }
1131 
1132 /*
1133  * Handle ":while" and ":for".
1134  */
1135     void
1136 ex_while(exarg_T *eap)
1137 {
1138     int		error;
1139     int		skip;
1140     int		result;
1141     cstack_T	*cstack = eap->cstack;
1142 
1143     if (cstack->cs_idx == CSTACK_LEN - 1)
1144 	eap->errmsg = _("E585: :while/:for nesting too deep");
1145     else
1146     {
1147 	/*
1148 	 * The loop flag is set when we have jumped back from the matching
1149 	 * ":endwhile" or ":endfor".  When not set, need to initialise this
1150 	 * cstack entry.
1151 	 */
1152 	if ((cstack->cs_lflags & CSL_HAD_LOOP) == 0)
1153 	{
1154 	    enter_block(cstack);
1155 	    ++cstack->cs_looplevel;
1156 	    cstack->cs_line[cstack->cs_idx] = -1;
1157 	}
1158 	else
1159 	{
1160 	    if (in_vim9script() && SCRIPT_ID_VALID(current_sctx.sc_sid))
1161 	    {
1162 		scriptitem_T	*si = SCRIPT_ITEM(current_sctx.sc_sid);
1163 		int		i;
1164 
1165 		// Any variables defined in the previous round are no longer
1166 		// visible.
1167 		for (i = cstack->cs_script_var_len[cstack->cs_idx];
1168 					       i < si->sn_var_vals.ga_len; ++i)
1169 		{
1170 		    svar_T	*sv = ((svar_T *)si->sn_var_vals.ga_data) + i;
1171 
1172 		    // sv_name is set to NULL if it was already removed.  This
1173 		    // happens when it was defined in an inner block and no
1174 		    // functions were defined there.
1175 		    if (sv->sv_name != NULL)
1176 			// Remove a variable declared inside the block, if it
1177 			// still exists, from sn_vars.
1178 			hide_script_var(si, i, FALSE);
1179 		}
1180 		cstack->cs_script_var_len[cstack->cs_idx] =
1181 							si->sn_var_vals.ga_len;
1182 	    }
1183 	}
1184 	cstack->cs_flags[cstack->cs_idx] =
1185 			       eap->cmdidx == CMD_while ? CSF_WHILE : CSF_FOR;
1186 
1187 	/*
1188 	 * Don't do something after an error, interrupt, or throw, or when
1189 	 * there is a surrounding conditional and it was not active.
1190 	 */
1191 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1192 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1193 	if (eap->cmdidx == CMD_while)
1194 	{
1195 	    /*
1196 	     * ":while bool-expr"
1197 	     */
1198 	    result = eval_to_bool(eap->arg, &error, eap, skip);
1199 	}
1200 	else
1201 	{
1202 	    void	*fi;
1203 	    evalarg_T	evalarg;
1204 
1205 	    /*
1206 	     * ":for var in list-expr"
1207 	     */
1208 	    CLEAR_FIELD(evalarg);
1209 	    evalarg.eval_flags = skip ? 0 : EVAL_EVALUATE;
1210 	    if (getline_equal(eap->getline, eap->cookie, getsourceline))
1211 	    {
1212 		evalarg.eval_getline = eap->getline;
1213 		evalarg.eval_cookie = eap->cookie;
1214 	    }
1215 
1216 	    if ((cstack->cs_lflags & CSL_HAD_LOOP) != 0)
1217 	    {
1218 		// Jumping here from a ":continue" or ":endfor": use the
1219 		// previously evaluated list.
1220 		fi = cstack->cs_forinfo[cstack->cs_idx];
1221 		error = FALSE;
1222 
1223 		// the "in expr" is not used, skip over it
1224 		skip_for_lines(fi, &evalarg);
1225 	    }
1226 	    else
1227 	    {
1228 		// Evaluate the argument and get the info in a structure.
1229 		fi = eval_for_line(eap->arg, &error, eap, &evalarg);
1230 		cstack->cs_forinfo[cstack->cs_idx] = fi;
1231 	    }
1232 
1233 	    // use the element at the start of the list and advance
1234 	    if (!error && fi != NULL && !skip)
1235 		result = next_for_item(fi, eap->arg);
1236 	    else
1237 		result = FALSE;
1238 
1239 	    if (!result)
1240 	    {
1241 		free_for_info(fi);
1242 		cstack->cs_forinfo[cstack->cs_idx] = NULL;
1243 	    }
1244 	    clear_evalarg(&evalarg, eap);
1245 	}
1246 
1247 	/*
1248 	 * If this cstack entry was just initialised and is active, set the
1249 	 * loop flag, so do_cmdline() will set the line number in cs_line[].
1250 	 * If executing the command a second time, clear the loop flag.
1251 	 */
1252 	if (!skip && !error && result)
1253 	{
1254 	    cstack->cs_flags[cstack->cs_idx] |= (CSF_ACTIVE | CSF_TRUE);
1255 	    cstack->cs_lflags ^= CSL_HAD_LOOP;
1256 	}
1257 	else
1258 	{
1259 	    cstack->cs_lflags &= ~CSL_HAD_LOOP;
1260 	    // If the ":while" evaluates to FALSE or ":for" is past the end of
1261 	    // the list, show the debug prompt at the ":endwhile"/":endfor" as
1262 	    // if there was a ":break" in a ":while"/":for" evaluating to
1263 	    // TRUE.
1264 	    if (!skip && !error)
1265 		cstack->cs_flags[cstack->cs_idx] |= CSF_TRUE;
1266 	}
1267     }
1268 }
1269 
1270 /*
1271  * ":continue"
1272  */
1273     void
1274 ex_continue(exarg_T *eap)
1275 {
1276     int		idx;
1277     cstack_T	*cstack = eap->cstack;
1278 
1279     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1280 	eap->errmsg = _(e_continue);
1281     else
1282     {
1283 	// Try to find the matching ":while".  This might stop at a try
1284 	// conditional not in its finally clause (which is then to be executed
1285 	// next).  Therefor, inactivate all conditionals except the ":while"
1286 	// itself (if reached).
1287 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1288 	if (idx >= 0 && (cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1289 	{
1290 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1291 
1292 	    /*
1293 	     * Set CSL_HAD_CONT, so do_cmdline() will jump back to the
1294 	     * matching ":while".
1295 	     */
1296 	    cstack->cs_lflags |= CSL_HAD_CONT;	// let do_cmdline() handle it
1297 	}
1298 	else
1299 	{
1300 	    // If a try conditional not in its finally clause is reached first,
1301 	    // make the ":continue" pending for execution at the ":endtry".
1302 	    cstack->cs_pending[idx] = CSTP_CONTINUE;
1303 	    report_make_pending(CSTP_CONTINUE, NULL);
1304 	}
1305     }
1306 }
1307 
1308 /*
1309  * ":break"
1310  */
1311     void
1312 ex_break(exarg_T *eap)
1313 {
1314     int		idx;
1315     cstack_T	*cstack = eap->cstack;
1316 
1317     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1318 	eap->errmsg = _(e_break);
1319     else
1320     {
1321 	// Inactivate conditionals until the matching ":while" or a try
1322 	// conditional not in its finally clause (which is then to be
1323 	// executed next) is found.  In the latter case, make the ":break"
1324 	// pending for execution at the ":endtry".
1325 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, TRUE);
1326 	if (idx >= 0 && !(cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1327 	{
1328 	    cstack->cs_pending[idx] = CSTP_BREAK;
1329 	    report_make_pending(CSTP_BREAK, NULL);
1330 	}
1331     }
1332 }
1333 
1334 /*
1335  * ":endwhile" and ":endfor"
1336  */
1337     void
1338 ex_endwhile(exarg_T *eap)
1339 {
1340     cstack_T	*cstack = eap->cstack;
1341     int		idx;
1342     char	*err;
1343     int		csf;
1344     int		fl;
1345 
1346     if (cmdmod_error())
1347 	return;
1348 
1349     if (eap->cmdidx == CMD_endwhile)
1350     {
1351 	err = e_while;
1352 	csf = CSF_WHILE;
1353     }
1354     else
1355     {
1356 	err = e_for;
1357 	csf = CSF_FOR;
1358     }
1359 
1360     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1361 	eap->errmsg = _(err);
1362     else
1363     {
1364 	fl =  cstack->cs_flags[cstack->cs_idx];
1365 	if (!(fl & csf))
1366 	{
1367 	    // If we are in a ":while" or ":for" but used the wrong endloop
1368 	    // command, do not rewind to the next enclosing ":for"/":while".
1369 	    if (fl & CSF_WHILE)
1370 		eap->errmsg = _("E732: Using :endfor with :while");
1371 	    else if (fl & CSF_FOR)
1372 		eap->errmsg = _("E733: Using :endwhile with :for");
1373 	}
1374 	if (!(fl & (CSF_WHILE | CSF_FOR)))
1375 	{
1376 	    if (!(fl & CSF_TRY))
1377 		eap->errmsg = _(e_endif);
1378 	    else if (fl & CSF_FINALLY)
1379 		eap->errmsg = _(e_endtry);
1380 	    // Try to find the matching ":while" and report what's missing.
1381 	    for (idx = cstack->cs_idx; idx > 0; --idx)
1382 	    {
1383 		fl =  cstack->cs_flags[idx];
1384 		if ((fl & CSF_TRY) && !(fl & CSF_FINALLY))
1385 		{
1386 		    // Give up at a try conditional not in its finally clause.
1387 		    // Ignore the ":endwhile"/":endfor".
1388 		    eap->errmsg = _(err);
1389 		    return;
1390 		}
1391 		if (fl & csf)
1392 		    break;
1393 	    }
1394 	    // Cleanup and rewind all contained (and unclosed) conditionals.
1395 	    (void)cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1396 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1397 	}
1398 
1399 	/*
1400 	 * When debugging or a breakpoint was encountered, display the debug
1401 	 * prompt (if not already done).  This shows the user that an
1402 	 * ":endwhile"/":endfor" is executed when the ":while" was not TRUE or
1403 	 * after a ":break".  Handle a ">quit" debug command as if an
1404 	 * interrupt had occurred before the ":endwhile"/":endfor".  That is,
1405 	 * throw an interrupt exception if appropriate.  Doing this here
1406 	 * prevents that an exception for a parsing error is discarded when
1407 	 * throwing the interrupt exception later on.
1408 	 */
1409 	else if (cstack->cs_flags[cstack->cs_idx] & CSF_TRUE
1410 		&& !(cstack->cs_flags[cstack->cs_idx] & CSF_ACTIVE)
1411 		&& dbg_check_skipped(eap))
1412 	    (void)do_intthrow(cstack);
1413 
1414 	// Set loop flag, so do_cmdline() will jump back to the matching
1415 	// ":while" or ":for".
1416 	cstack->cs_lflags |= CSL_HAD_ENDLOOP;
1417     }
1418 }
1419 
1420 /*
1421  * "{" start of a block in Vim9 script
1422  */
1423     void
1424 ex_block(exarg_T *eap)
1425 {
1426     cstack_T	*cstack = eap->cstack;
1427 
1428     if (cstack->cs_idx == CSTACK_LEN - 1)
1429 	eap->errmsg = _("E579: block nesting too deep");
1430     else
1431     {
1432 	enter_block(cstack);
1433 	cstack->cs_flags[cstack->cs_idx] = CSF_BLOCK | CSF_ACTIVE | CSF_TRUE;
1434     }
1435 }
1436 
1437 /*
1438  * "}" end of a block in Vim9 script
1439  */
1440     void
1441 ex_endblock(exarg_T *eap)
1442 {
1443     cstack_T	*cstack = eap->cstack;
1444 
1445     if (cstack->cs_idx < 0
1446 	    || (cstack->cs_flags[cstack->cs_idx] & CSF_BLOCK) == 0)
1447 	eap->errmsg = _(e_endblock_without_block);
1448     else
1449 	leave_block(cstack);
1450 }
1451 
1452 /*
1453  * ":throw expr"
1454  */
1455     void
1456 ex_throw(exarg_T *eap)
1457 {
1458     char_u	*arg = eap->arg;
1459     char_u	*value;
1460 
1461     if (*arg != NUL && *arg != '|' && *arg != '\n')
1462 	value = eval_to_string_skip(arg, eap, eap->skip);
1463     else
1464     {
1465 	emsg(_(e_argreq));
1466 	value = NULL;
1467     }
1468 
1469     // On error or when an exception is thrown during argument evaluation, do
1470     // not throw.
1471     if (!eap->skip && value != NULL)
1472     {
1473 	if (throw_exception(value, ET_USER, NULL) == FAIL)
1474 	    vim_free(value);
1475 	else
1476 	    do_throw(eap->cstack);
1477     }
1478 }
1479 
1480 /*
1481  * Throw the current exception through the specified cstack.  Common routine
1482  * for ":throw" (user exception) and error and interrupt exceptions.  Also
1483  * used for rethrowing an uncaught exception.
1484  */
1485     void
1486 do_throw(cstack_T *cstack)
1487 {
1488     int		idx;
1489     int		inactivate_try = FALSE;
1490 
1491     /*
1492      * Cleanup and inactivate up to the next surrounding try conditional that
1493      * is not in its finally clause.  Normally, do not inactivate the try
1494      * conditional itself, so that its ACTIVE flag can be tested below.  But
1495      * if a previous error or interrupt has not been converted to an exception,
1496      * inactivate the try conditional, too, as if the conversion had been done,
1497      * and reset the did_emsg or got_int flag, so this won't happen again at
1498      * the next surrounding try conditional.
1499      */
1500 #ifndef THROW_ON_ERROR_TRUE
1501     if (did_emsg && !THROW_ON_ERROR)
1502     {
1503 	inactivate_try = TRUE;
1504 	did_emsg = FALSE;
1505     }
1506 #endif
1507 #ifndef THROW_ON_INTERRUPT_TRUE
1508     if (got_int && !THROW_ON_INTERRUPT)
1509     {
1510 	inactivate_try = TRUE;
1511 	got_int = FALSE;
1512     }
1513 #endif
1514     idx = cleanup_conditionals(cstack, 0, inactivate_try);
1515     if (idx >= 0)
1516     {
1517 	/*
1518 	 * If this try conditional is active and we are before its first
1519 	 * ":catch", set THROWN so that the ":catch" commands will check
1520 	 * whether the exception matches.  When the exception came from any of
1521 	 * the catch clauses, it will be made pending at the ":finally" (if
1522 	 * present) and rethrown at the ":endtry".  This will also happen if
1523 	 * the try conditional is inactive.  This is the case when we are
1524 	 * throwing an exception due to an error or interrupt on the way from
1525 	 * a preceding ":continue", ":break", ":return", ":finish", error or
1526 	 * interrupt (not converted to an exception) to the finally clause or
1527 	 * from a preceding throw of a user or error or interrupt exception to
1528 	 * the matching catch clause or the finally clause.
1529 	 */
1530 	if (!(cstack->cs_flags[idx] & CSF_CAUGHT))
1531 	{
1532 	    if (cstack->cs_flags[idx] & CSF_ACTIVE)
1533 		cstack->cs_flags[idx] |= CSF_THROWN;
1534 	    else
1535 		// THROWN may have already been set for a catchable exception
1536 		// that has been discarded.  Ensure it is reset for the new
1537 		// exception.
1538 		cstack->cs_flags[idx] &= ~CSF_THROWN;
1539 	}
1540 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
1541 	cstack->cs_exception[idx] = current_exception;
1542     }
1543 #if 0
1544     // TODO: Add optimization below.  Not yet done because of interface
1545     // problems to eval.c and ex_cmds2.c. (Servatius)
1546     else
1547     {
1548 	/*
1549 	 * There are no catch clauses to check or finally clauses to execute.
1550 	 * End the current script or function.  The exception will be rethrown
1551 	 * in the caller.
1552 	 */
1553 	if (getline_equal(eap->getline, eap->cookie, get_func_line))
1554 	    current_funccal->returned = TRUE;
1555 	elseif (eap->get_func_line == getsourceline)
1556 	    ((struct source_cookie *)eap->cookie)->finished = TRUE;
1557     }
1558 #endif
1559 
1560     did_throw = TRUE;
1561 }
1562 
1563 /*
1564  * ":try"
1565  */
1566     void
1567 ex_try(exarg_T *eap)
1568 {
1569     int		skip;
1570     cstack_T	*cstack = eap->cstack;
1571 
1572     if (cmdmod_error())
1573 	return;
1574 
1575     if (cstack->cs_idx == CSTACK_LEN - 1)
1576 	eap->errmsg = _("E601: :try nesting too deep");
1577     else
1578     {
1579 	enter_block(cstack);
1580 	++cstack->cs_trylevel;
1581 	cstack->cs_flags[cstack->cs_idx] = CSF_TRY;
1582 	cstack->cs_pending[cstack->cs_idx] = CSTP_NONE;
1583 
1584 	/*
1585 	 * Don't do something after an error, interrupt, or throw, or when there
1586 	 * is a surrounding conditional and it was not active.
1587 	 */
1588 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1589 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1590 
1591 	if (!skip)
1592 	{
1593 	    // Set ACTIVE and TRUE.  TRUE means that the corresponding ":catch"
1594 	    // commands should check for a match if an exception is thrown and
1595 	    // that the finally clause needs to be executed.
1596 	    cstack->cs_flags[cstack->cs_idx] |= CSF_ACTIVE | CSF_TRUE;
1597 
1598 	    /*
1599 	     * ":silent!", even when used in a try conditional, disables
1600 	     * displaying of error messages and conversion of errors to
1601 	     * exceptions.  When the silent commands again open a try
1602 	     * conditional, save "emsg_silent" and reset it so that errors are
1603 	     * again converted to exceptions.  The value is restored when that
1604 	     * try conditional is left.  If it is left normally, the commands
1605 	     * following the ":endtry" are again silent.  If it is left by
1606 	     * a ":continue", ":break", ":return", or ":finish", the commands
1607 	     * executed next are again silent.  If it is left due to an
1608 	     * aborting error, an interrupt, or an exception, restoring
1609 	     * "emsg_silent" does not matter since we are already in the
1610 	     * aborting state and/or the exception has already been thrown.
1611 	     * The effect is then just freeing the memory that was allocated
1612 	     * to save the value.
1613 	     */
1614 	    if (emsg_silent)
1615 	    {
1616 		eslist_T	*elem;
1617 
1618 		elem = ALLOC_ONE(struct eslist_elem);
1619 		if (elem == NULL)
1620 		    emsg(_(e_outofmem));
1621 		else
1622 		{
1623 		    elem->saved_emsg_silent = emsg_silent;
1624 		    elem->next = cstack->cs_emsg_silent_list;
1625 		    cstack->cs_emsg_silent_list = elem;
1626 		    cstack->cs_flags[cstack->cs_idx] |= CSF_SILENT;
1627 		    emsg_silent = 0;
1628 		}
1629 	    }
1630 	}
1631 
1632     }
1633 }
1634 
1635 /*
1636  * ":catch /{pattern}/" and ":catch"
1637  */
1638     void
1639 ex_catch(exarg_T *eap)
1640 {
1641     int		idx = 0;
1642     int		give_up = FALSE;
1643     int		skip = FALSE;
1644     int		caught = FALSE;
1645     char_u	*end;
1646     int		save_char = 0;
1647     char_u	*save_cpo;
1648     regmatch_T	regmatch;
1649     int		prev_got_int;
1650     cstack_T	*cstack = eap->cstack;
1651     char_u	*pat;
1652 
1653     if (cmdmod_error())
1654 	return;
1655 
1656     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1657     {
1658 	eap->errmsg = _(e_catch);
1659 	give_up = TRUE;
1660     }
1661     else
1662     {
1663 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1664 	{
1665 	    // Report what's missing if the matching ":try" is not in its
1666 	    // finally clause.
1667 	    eap->errmsg = get_end_emsg(cstack);
1668 	    skip = TRUE;
1669 	}
1670 	for (idx = cstack->cs_idx; idx > 0; --idx)
1671 	    if (cstack->cs_flags[idx] & CSF_TRY)
1672 		break;
1673 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1674 	{
1675 	    // Give up for a ":catch" after ":finally" and ignore it.
1676 	    // Just parse.
1677 	    eap->errmsg = _("E604: :catch after :finally");
1678 	    give_up = TRUE;
1679 	}
1680 	else
1681 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1682 						       &cstack->cs_looplevel);
1683     }
1684 
1685     if (ends_excmd2(eap->cmd, eap->arg))   // no argument, catch all errors
1686     {
1687 	pat = (char_u *)".*";
1688 	end = NULL;
1689 	eap->nextcmd = find_nextcmd(eap->arg);
1690     }
1691     else
1692     {
1693 	pat = eap->arg + 1;
1694 	end = skip_regexp_err(pat, *eap->arg, TRUE);
1695 	if (end == NULL)
1696 	    give_up = TRUE;
1697     }
1698 
1699     if (!give_up)
1700     {
1701 	/*
1702 	 * Don't do something when no exception has been thrown or when the
1703 	 * corresponding try block never got active (because of an inactive
1704 	 * surrounding conditional or after an error or interrupt or throw).
1705 	 */
1706 	if (!did_throw || !(cstack->cs_flags[idx] & CSF_TRUE))
1707 	    skip = TRUE;
1708 
1709 	/*
1710 	 * Check for a match only if an exception is thrown but not caught by
1711 	 * a previous ":catch".  An exception that has replaced a discarded
1712 	 * exception is not checked (THROWN is not set then).
1713 	 */
1714 	if (!skip && (cstack->cs_flags[idx] & CSF_THROWN)
1715 		&& !(cstack->cs_flags[idx] & CSF_CAUGHT))
1716 	{
1717 	    if (end != NULL && *end != NUL
1718 				      && !ends_excmd2(end, skipwhite(end + 1)))
1719 	    {
1720 		semsg(_(e_trailing_arg), end);
1721 		return;
1722 	    }
1723 
1724 	    // When debugging or a breakpoint was encountered, display the
1725 	    // debug prompt (if not already done) before checking for a match.
1726 	    // This is a helpful hint for the user when the regular expression
1727 	    // matching fails.  Handle a ">quit" debug command as if an
1728 	    // interrupt had occurred before the ":catch".  That is, discard
1729 	    // the original exception, replace it by an interrupt exception,
1730 	    // and don't catch it in this try block.
1731 	    if (!dbg_check_skipped(eap) || !do_intthrow(cstack))
1732 	    {
1733 		// Terminate the pattern and avoid the 'l' flag in 'cpoptions'
1734 		// while compiling it.
1735 		if (end != NULL)
1736 		{
1737 		    save_char = *end;
1738 		    *end = NUL;
1739 		}
1740 		save_cpo  = p_cpo;
1741 		p_cpo = empty_option;
1742 		// Disable error messages, it will make current_exception
1743 		// invalid.
1744 		++emsg_off;
1745 		regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1746 		--emsg_off;
1747 		regmatch.rm_ic = FALSE;
1748 		if (end != NULL)
1749 		    *end = save_char;
1750 		p_cpo = save_cpo;
1751 		if (regmatch.regprog == NULL)
1752 		    semsg(_(e_invarg2), pat);
1753 		else
1754 		{
1755 		    /*
1756 		     * Save the value of got_int and reset it.  We don't want
1757 		     * a previous interruption cancel matching, only hitting
1758 		     * CTRL-C while matching should abort it.
1759 		     */
1760 		    prev_got_int = got_int;
1761 		    got_int = FALSE;
1762 		    caught = vim_regexec_nl(&regmatch,
1763 			       (char_u *)current_exception->value, (colnr_T)0);
1764 		    got_int |= prev_got_int;
1765 		    vim_regfree(regmatch.regprog);
1766 		}
1767 	    }
1768 	}
1769 
1770 	if (caught)
1771 	{
1772 	    // Make this ":catch" clause active and reset did_emsg, got_int,
1773 	    // and did_throw.  Put the exception on the caught stack.
1774 	    cstack->cs_flags[idx] |= CSF_ACTIVE | CSF_CAUGHT;
1775 	    did_emsg = got_int = did_throw = FALSE;
1776 	    catch_exception((except_T *)cstack->cs_exception[idx]);
1777 	    // It's mandatory that the current exception is stored in the cstack
1778 	    // so that it can be discarded at the next ":catch", ":finally", or
1779 	    // ":endtry" or when the catch clause is left by a ":continue",
1780 	    // ":break", ":return", ":finish", error, interrupt, or another
1781 	    // exception.
1782 	    if (cstack->cs_exception[cstack->cs_idx] != current_exception)
1783 		internal_error("ex_catch()");
1784 	}
1785 	else
1786 	{
1787 	    /*
1788 	     * If there is a preceding catch clause and it caught the exception,
1789 	     * finish the exception now.  This happens also after errors except
1790 	     * when this ":catch" was after the ":finally" or not within
1791 	     * a ":try".  Make the try conditional inactive so that the
1792 	     * following catch clauses are skipped.  On an error or interrupt
1793 	     * after the preceding try block or catch clause was left by
1794 	     * a ":continue", ":break", ":return", or ":finish", discard the
1795 	     * pending action.
1796 	     */
1797 	    cleanup_conditionals(cstack, CSF_TRY, TRUE);
1798 	}
1799     }
1800 
1801     if (end != NULL)
1802 	eap->nextcmd = find_nextcmd(end);
1803 }
1804 
1805 /*
1806  * ":finally"
1807  */
1808     void
1809 ex_finally(exarg_T *eap)
1810 {
1811     int		idx;
1812     int		skip = FALSE;
1813     int		pending = CSTP_NONE;
1814     cstack_T	*cstack = eap->cstack;
1815 
1816     if (cmdmod_error())
1817 	return;
1818 
1819     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1820 	eap->errmsg = _(e_finally);
1821     else
1822     {
1823 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1824 	{
1825 	    eap->errmsg = get_end_emsg(cstack);
1826 	    for (idx = cstack->cs_idx - 1; idx > 0; --idx)
1827 		if (cstack->cs_flags[idx] & CSF_TRY)
1828 		    break;
1829 	    // Make this error pending, so that the commands in the following
1830 	    // finally clause can be executed.  This overrules also a pending
1831 	    // ":continue", ":break", ":return", or ":finish".
1832 	    pending = CSTP_ERROR;
1833 	}
1834 	else
1835 	    idx = cstack->cs_idx;
1836 
1837 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1838 	{
1839 	    // Give up for a multiple ":finally" and ignore it.
1840 	    eap->errmsg = _(e_finally_dup);
1841 	    return;
1842 	}
1843 	rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1844 						       &cstack->cs_looplevel);
1845 
1846 	/*
1847 	 * Don't do something when the corresponding try block never got active
1848 	 * (because of an inactive surrounding conditional or after an error or
1849 	 * interrupt or throw) or for a ":finally" without ":try" or a multiple
1850 	 * ":finally".  After every other error (did_emsg or the conditional
1851 	 * errors detected above) or after an interrupt (got_int) or an
1852 	 * exception (did_throw), the finally clause must be executed.
1853 	 */
1854 	skip = !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1855 
1856 	if (!skip)
1857 	{
1858 	    // When debugging or a breakpoint was encountered, display the
1859 	    // debug prompt (if not already done).  The user then knows that the
1860 	    // finally clause is executed.
1861 	    if (dbg_check_skipped(eap))
1862 	    {
1863 		// Handle a ">quit" debug command as if an interrupt had
1864 		// occurred before the ":finally".  That is, discard the
1865 		// original exception and replace it by an interrupt
1866 		// exception.
1867 		(void)do_intthrow(cstack);
1868 	    }
1869 
1870 	    /*
1871 	     * If there is a preceding catch clause and it caught the exception,
1872 	     * finish the exception now.  This happens also after errors except
1873 	     * when this is a multiple ":finally" or one not within a ":try".
1874 	     * After an error or interrupt, this also discards a pending
1875 	     * ":continue", ":break", ":finish", or ":return" from the preceding
1876 	     * try block or catch clause.
1877 	     */
1878 	    cleanup_conditionals(cstack, CSF_TRY, FALSE);
1879 
1880 	    /*
1881 	     * Make did_emsg, got_int, did_throw pending.  If set, they overrule
1882 	     * a pending ":continue", ":break", ":return", or ":finish".  Then
1883 	     * we have particularly to discard a pending return value (as done
1884 	     * by the call to cleanup_conditionals() above when did_emsg or
1885 	     * got_int is set).  The pending values are restored by the
1886 	     * ":endtry", except if there is a new error, interrupt, exception,
1887 	     * ":continue", ":break", ":return", or ":finish" in the following
1888 	     * finally clause.  A missing ":endwhile", ":endfor" or ":endif"
1889 	     * detected here is treated as if did_emsg and did_throw had
1890 	     * already been set, respectively in case that the error is not
1891 	     * converted to an exception, did_throw had already been unset.
1892 	     * We must not set did_emsg here since that would suppress the
1893 	     * error message.
1894 	     */
1895 	    if (pending == CSTP_ERROR || did_emsg || got_int || did_throw)
1896 	    {
1897 		if (cstack->cs_pending[cstack->cs_idx] == CSTP_RETURN)
1898 		{
1899 		    report_discard_pending(CSTP_RETURN,
1900 					   cstack->cs_rettv[cstack->cs_idx]);
1901 		    discard_pending_return(cstack->cs_rettv[cstack->cs_idx]);
1902 		}
1903 		if (pending == CSTP_ERROR && !did_emsg)
1904 		    pending |= (THROW_ON_ERROR) ? CSTP_THROW : 0;
1905 		else
1906 		    pending |= did_throw ? CSTP_THROW : 0;
1907 		pending |= did_emsg  ? CSTP_ERROR     : 0;
1908 		pending |= got_int   ? CSTP_INTERRUPT : 0;
1909 		cstack->cs_pending[cstack->cs_idx] = pending;
1910 
1911 		// It's mandatory that the current exception is stored in the
1912 		// cstack so that it can be rethrown at the ":endtry" or be
1913 		// discarded if the finally clause is left by a ":continue",
1914 		// ":break", ":return", ":finish", error, interrupt, or another
1915 		// exception.  When emsg() is called for a missing ":endif" or
1916 		// a missing ":endwhile"/":endfor" detected here, the
1917 		// exception will be discarded.
1918 		if (did_throw && cstack->cs_exception[cstack->cs_idx]
1919 							 != current_exception)
1920 		    internal_error("ex_finally()");
1921 	    }
1922 
1923 	    /*
1924 	     * Set CSL_HAD_FINA, so do_cmdline() will reset did_emsg,
1925 	     * got_int, and did_throw and make the finally clause active.
1926 	     * This will happen after emsg() has been called for a missing
1927 	     * ":endif" or a missing ":endwhile"/":endfor" detected here, so
1928 	     * that the following finally clause will be executed even then.
1929 	     */
1930 	    cstack->cs_lflags |= CSL_HAD_FINA;
1931 	}
1932     }
1933 }
1934 
1935 /*
1936  * ":endtry"
1937  */
1938     void
1939 ex_endtry(exarg_T *eap)
1940 {
1941     int		idx;
1942     int		skip;
1943     int		rethrow = FALSE;
1944     int		pending = CSTP_NONE;
1945     void	*rettv = NULL;
1946     cstack_T	*cstack = eap->cstack;
1947 
1948     if (cmdmod_error())
1949 	return;
1950 
1951     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1952 	eap->errmsg = _(e_no_endtry);
1953     else
1954     {
1955 	/*
1956 	 * Don't do something after an error, interrupt or throw in the try
1957 	 * block, catch clause, or finally clause preceding this ":endtry" or
1958 	 * when an error or interrupt occurred after a ":continue", ":break",
1959 	 * ":return", or ":finish" in a try block or catch clause preceding this
1960 	 * ":endtry" or when the try block never got active (because of an
1961 	 * inactive surrounding conditional or after an error or interrupt or
1962 	 * throw) or when there is a surrounding conditional and it has been
1963 	 * made inactive by a ":continue", ":break", ":return", or ":finish" in
1964 	 * the finally clause.  The latter case need not be tested since then
1965 	 * anything pending has already been discarded. */
1966 	skip = did_emsg || got_int || did_throw ||
1967 	    !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1968 
1969 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1970 	{
1971 	    eap->errmsg = get_end_emsg(cstack);
1972 	    // Find the matching ":try" and report what's missing.
1973 	    idx = cstack->cs_idx;
1974 	    do
1975 		--idx;
1976 	    while (idx > 0 && !(cstack->cs_flags[idx] & CSF_TRY));
1977 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1978 						       &cstack->cs_looplevel);
1979 	    skip = TRUE;
1980 
1981 	    /*
1982 	     * If an exception is being thrown, discard it to prevent it from
1983 	     * being rethrown at the end of this function.  It would be
1984 	     * discarded by the error message, anyway.  Resets did_throw.
1985 	     * This does not affect the script termination due to the error
1986 	     * since "trylevel" is decremented after emsg() has been called.
1987 	     */
1988 	    if (did_throw)
1989 		discard_current_exception();
1990 	}
1991 	else
1992 	{
1993 	    idx = cstack->cs_idx;
1994 
1995 	    /*
1996 	     * If we stopped with the exception currently being thrown at this
1997 	     * try conditional since we didn't know that it doesn't have
1998 	     * a finally clause, we need to rethrow it after closing the try
1999 	     * conditional.
2000 	     */
2001 	    if (did_throw && (cstack->cs_flags[idx] & CSF_TRUE)
2002 		    && !(cstack->cs_flags[idx] & CSF_FINALLY))
2003 		rethrow = TRUE;
2004 	}
2005 
2006 	// If there was no finally clause, show the user when debugging or
2007 	// a breakpoint was encountered that the end of the try conditional has
2008 	// been reached: display the debug prompt (if not already done).  Do
2009 	// this on normal control flow or when an exception was thrown, but not
2010 	// on an interrupt or error not converted to an exception or when
2011 	// a ":break", ":continue", ":return", or ":finish" is pending.  These
2012 	// actions are carried out immediately.
2013 	if ((rethrow || (!skip
2014 			&& !(cstack->cs_flags[idx] & CSF_FINALLY)
2015 			&& !cstack->cs_pending[idx]))
2016 		&& dbg_check_skipped(eap))
2017 	{
2018 	    // Handle a ">quit" debug command as if an interrupt had occurred
2019 	    // before the ":endtry".  That is, throw an interrupt exception and
2020 	    // set "skip" and "rethrow".
2021 	    if (got_int)
2022 	    {
2023 		skip = TRUE;
2024 		(void)do_intthrow(cstack);
2025 		// The do_intthrow() call may have reset did_throw or
2026 		// cstack->cs_pending[idx].
2027 		rethrow = FALSE;
2028 		if (did_throw && !(cstack->cs_flags[idx] & CSF_FINALLY))
2029 		    rethrow = TRUE;
2030 	    }
2031 	}
2032 
2033 	/*
2034 	 * If a ":return" is pending, we need to resume it after closing the
2035 	 * try conditional; remember the return value.  If there was a finally
2036 	 * clause making an exception pending, we need to rethrow it.  Make it
2037 	 * the exception currently being thrown.
2038 	 */
2039 	if (!skip)
2040 	{
2041 	    pending = cstack->cs_pending[idx];
2042 	    cstack->cs_pending[idx] = CSTP_NONE;
2043 	    if (pending == CSTP_RETURN)
2044 		rettv = cstack->cs_rettv[idx];
2045 	    else if (pending & CSTP_THROW)
2046 		current_exception = cstack->cs_exception[idx];
2047 	}
2048 
2049 	/*
2050 	 * Discard anything pending on an error, interrupt, or throw in the
2051 	 * finally clause.  If there was no ":finally", discard a pending
2052 	 * ":continue", ":break", ":return", or ":finish" if an error or
2053 	 * interrupt occurred afterwards, but before the ":endtry" was reached.
2054 	 * If an exception was caught by the last of the catch clauses and there
2055 	 * was no finally clause, finish the exception now.  This happens also
2056 	 * after errors except when this ":endtry" is not within a ":try".
2057 	 * Restore "emsg_silent" if it has been reset by this try conditional.
2058 	 */
2059 	(void)cleanup_conditionals(cstack, CSF_TRY | CSF_SILENT, TRUE);
2060 
2061 	leave_block(cstack);
2062 	--cstack->cs_trylevel;
2063 
2064 	if (!skip)
2065 	{
2066 	    report_resume_pending(pending,
2067 		    (pending == CSTP_RETURN) ? rettv :
2068 		    (pending & CSTP_THROW) ? (void *)current_exception : NULL);
2069 	    switch (pending)
2070 	    {
2071 		case CSTP_NONE:
2072 		    break;
2073 
2074 		// Reactivate a pending ":continue", ":break", ":return",
2075 		// ":finish" from the try block or a catch clause of this try
2076 		// conditional.  This is skipped, if there was an error in an
2077 		// (unskipped) conditional command or an interrupt afterwards
2078 		// or if the finally clause is present and executed a new error,
2079 		// interrupt, throw, ":continue", ":break", ":return", or
2080 		// ":finish".
2081 		case CSTP_CONTINUE:
2082 		    ex_continue(eap);
2083 		    break;
2084 		case CSTP_BREAK:
2085 		    ex_break(eap);
2086 		    break;
2087 		case CSTP_RETURN:
2088 		    do_return(eap, FALSE, FALSE, rettv);
2089 		    break;
2090 		case CSTP_FINISH:
2091 		    do_finish(eap, FALSE);
2092 		    break;
2093 
2094 		// When the finally clause was entered due to an error,
2095 		// interrupt or throw (as opposed to a ":continue", ":break",
2096 		// ":return", or ":finish"), restore the pending values of
2097 		// did_emsg, got_int, and did_throw.  This is skipped, if there
2098 		// was a new error, interrupt, throw, ":continue", ":break",
2099 		// ":return", or ":finish".  in the finally clause.
2100 		default:
2101 		    if (pending & CSTP_ERROR)
2102 			did_emsg = TRUE;
2103 		    if (pending & CSTP_INTERRUPT)
2104 			got_int = TRUE;
2105 		    if (pending & CSTP_THROW)
2106 			rethrow = TRUE;
2107 		    break;
2108 	    }
2109 	}
2110 
2111 	if (rethrow)
2112 	    // Rethrow the current exception (within this cstack).
2113 	    do_throw(cstack);
2114     }
2115 }
2116 
2117 /*
2118  * enter_cleanup() and leave_cleanup()
2119  *
2120  * Functions to be called before/after invoking a sequence of autocommands for
2121  * cleanup for a failed command.  (Failure means here that a call to emsg()
2122  * has been made, an interrupt occurred, or there is an uncaught exception
2123  * from a previous autocommand execution of the same command.)
2124  *
2125  * Call enter_cleanup() with a pointer to a cleanup_T and pass the same
2126  * pointer to leave_cleanup().  The cleanup_T structure stores the pending
2127  * error/interrupt/exception state.
2128  */
2129 
2130 /*
2131  * This function works a bit like ex_finally() except that there was not
2132  * actually an extra try block around the part that failed and an error or
2133  * interrupt has not (yet) been converted to an exception.  This function
2134  * saves the error/interrupt/ exception state and prepares for the call to
2135  * do_cmdline() that is going to be made for the cleanup autocommand
2136  * execution.
2137  */
2138     void
2139 enter_cleanup(cleanup_T *csp)
2140 {
2141     int		pending = CSTP_NONE;
2142 
2143     /*
2144      * Postpone did_emsg, got_int, did_throw.  The pending values will be
2145      * restored by leave_cleanup() except if there was an aborting error,
2146      * interrupt, or uncaught exception after this function ends.
2147      */
2148     if (did_emsg || got_int || did_throw || need_rethrow)
2149     {
2150 	csp->pending = (did_emsg     ? CSTP_ERROR     : 0)
2151 		     | (got_int      ? CSTP_INTERRUPT : 0)
2152 		     | (did_throw    ? CSTP_THROW     : 0)
2153 		     | (need_rethrow ? CSTP_THROW     : 0);
2154 
2155 	// If we are currently throwing an exception (did_throw), save it as
2156 	// well.  On an error not yet converted to an exception, update
2157 	// "force_abort" and reset "cause_abort" (as do_errthrow() would do).
2158 	// This is needed for the do_cmdline() call that is going to be made
2159 	// for autocommand execution.  We need not save *msg_list because
2160 	// there is an extra instance for every call of do_cmdline(), anyway.
2161 	if (did_throw || need_rethrow)
2162 	{
2163 	    csp->exception = current_exception;
2164 	    current_exception = NULL;
2165 	}
2166 	else
2167 	{
2168 	    csp->exception = NULL;
2169 	    if (did_emsg)
2170 	    {
2171 		force_abort |= cause_abort;
2172 		cause_abort = FALSE;
2173 	    }
2174 	}
2175 	did_emsg = got_int = did_throw = need_rethrow = FALSE;
2176 
2177 	// Report if required by the 'verbose' option or when debugging.
2178 	report_make_pending(pending, csp->exception);
2179     }
2180     else
2181     {
2182 	csp->pending = CSTP_NONE;
2183 	csp->exception = NULL;
2184     }
2185 }
2186 
2187 /*
2188  * See comment above enter_cleanup() for how this function is used.
2189  *
2190  * This function is a bit like ex_endtry() except that there was not actually
2191  * an extra try block around the part that failed and an error or interrupt
2192  * had not (yet) been converted to an exception when the cleanup autocommand
2193  * sequence was invoked.
2194  *
2195  * This function has to be called with the address of the cleanup_T structure
2196  * filled by enter_cleanup() as an argument; it restores the error/interrupt/
2197  * exception state saved by that function - except there was an aborting
2198  * error, an interrupt or an uncaught exception during execution of the
2199  * cleanup autocommands.  In the latter case, the saved error/interrupt/
2200  * exception state is discarded.
2201  */
2202     void
2203 leave_cleanup(cleanup_T *csp)
2204 {
2205     int		pending = csp->pending;
2206 
2207     if (pending == CSTP_NONE)	// nothing to do
2208 	return;
2209 
2210     // If there was an aborting error, an interrupt, or an uncaught exception
2211     // after the corresponding call to enter_cleanup(), discard what has been
2212     // made pending by it.  Report this to the user if required by the
2213     // 'verbose' option or when debugging.
2214     if (aborting() || need_rethrow)
2215     {
2216 	if (pending & CSTP_THROW)
2217 	    // Cancel the pending exception (includes report).
2218 	    discard_exception((except_T *)csp->exception, FALSE);
2219 	else
2220 	    report_discard_pending(pending, NULL);
2221 
2222 	// If an error was about to be converted to an exception when
2223 	// enter_cleanup() was called, free the message list.
2224 	if (msg_list != NULL)
2225 	    free_global_msglist();
2226     }
2227 
2228     /*
2229      * If there was no new error, interrupt, or throw between the calls
2230      * to enter_cleanup() and leave_cleanup(), restore the pending
2231      * error/interrupt/exception state.
2232      */
2233     else
2234     {
2235 	/*
2236 	 * If there was an exception being thrown when enter_cleanup() was
2237 	 * called, we need to rethrow it.  Make it the exception currently
2238 	 * being thrown.
2239 	 */
2240 	if (pending & CSTP_THROW)
2241 	    current_exception = csp->exception;
2242 
2243 	/*
2244 	 * If an error was about to be converted to an exception when
2245 	 * enter_cleanup() was called, let "cause_abort" take the part of
2246 	 * "force_abort" (as done by cause_errthrow()).
2247 	 */
2248 	else if (pending & CSTP_ERROR)
2249 	{
2250 	    cause_abort = force_abort;
2251 	    force_abort = FALSE;
2252 	}
2253 
2254 	/*
2255 	 * Restore the pending values of did_emsg, got_int, and did_throw.
2256 	 */
2257 	if (pending & CSTP_ERROR)
2258 	    did_emsg = TRUE;
2259 	if (pending & CSTP_INTERRUPT)
2260 	    got_int = TRUE;
2261 	if (pending & CSTP_THROW)
2262 	    need_rethrow = TRUE;    // did_throw will be set by do_one_cmd()
2263 
2264 	// Report if required by the 'verbose' option or when debugging.
2265 	report_resume_pending(pending,
2266 		   (pending & CSTP_THROW) ? (void *)current_exception : NULL);
2267     }
2268 }
2269 
2270 
2271 /*
2272  * Make conditionals inactive and discard what's pending in finally clauses
2273  * until the conditional type searched for or a try conditional not in its
2274  * finally clause is reached.  If this is in an active catch clause, finish
2275  * the caught exception.
2276  * Return the cstack index where the search stopped.
2277  * Values used for "searched_cond" are (CSF_WHILE | CSF_FOR) or CSF_TRY or 0,
2278  * the latter meaning the innermost try conditional not in its finally clause.
2279  * "inclusive" tells whether the conditional searched for should be made
2280  * inactive itself (a try conditional not in its finally clause possibly find
2281  * before is always made inactive).  If "inclusive" is TRUE and
2282  * "searched_cond" is CSF_TRY|CSF_SILENT, the saved former value of
2283  * "emsg_silent", if reset when the try conditional finally reached was
2284  * entered, is restored (used by ex_endtry()).  This is normally done only
2285  * when such a try conditional is left.
2286  */
2287     int
2288 cleanup_conditionals(
2289     cstack_T   *cstack,
2290     int		searched_cond,
2291     int		inclusive)
2292 {
2293     int		idx;
2294     int		stop = FALSE;
2295 
2296     for (idx = cstack->cs_idx; idx >= 0; --idx)
2297     {
2298 	if (cstack->cs_flags[idx] & CSF_TRY)
2299 	{
2300 	    /*
2301 	     * Discard anything pending in a finally clause and continue the
2302 	     * search.  There may also be a pending ":continue", ":break",
2303 	     * ":return", or ":finish" before the finally clause.  We must not
2304 	     * discard it, unless an error or interrupt occurred afterwards.
2305 	     */
2306 	    if (did_emsg || got_int || (cstack->cs_flags[idx] & CSF_FINALLY))
2307 	    {
2308 		switch (cstack->cs_pending[idx])
2309 		{
2310 		    case CSTP_NONE:
2311 			break;
2312 
2313 		    case CSTP_CONTINUE:
2314 		    case CSTP_BREAK:
2315 		    case CSTP_FINISH:
2316 			report_discard_pending(cstack->cs_pending[idx], NULL);
2317 			cstack->cs_pending[idx] = CSTP_NONE;
2318 			break;
2319 
2320 		    case CSTP_RETURN:
2321 			report_discard_pending(CSTP_RETURN,
2322 						      cstack->cs_rettv[idx]);
2323 			discard_pending_return(cstack->cs_rettv[idx]);
2324 			cstack->cs_pending[idx] = CSTP_NONE;
2325 			break;
2326 
2327 		    default:
2328 			if (cstack->cs_flags[idx] & CSF_FINALLY)
2329 			{
2330 			    if (cstack->cs_pending[idx] & CSTP_THROW)
2331 			    {
2332 				// Cancel the pending exception.  This is in the
2333 				// finally clause, so that the stack of the
2334 				// caught exceptions is not involved.
2335 				discard_exception(
2336 					(except_T *)cstack->cs_exception[idx],
2337 					FALSE);
2338 			    }
2339 			    else
2340 				report_discard_pending(cstack->cs_pending[idx],
2341 					NULL);
2342 			    cstack->cs_pending[idx] = CSTP_NONE;
2343 			}
2344 			break;
2345 		}
2346 	    }
2347 
2348 	    /*
2349 	     * Stop at a try conditional not in its finally clause.  If this try
2350 	     * conditional is in an active catch clause, finish the caught
2351 	     * exception.
2352 	     */
2353 	    if (!(cstack->cs_flags[idx] & CSF_FINALLY))
2354 	    {
2355 		if ((cstack->cs_flags[idx] & CSF_ACTIVE)
2356 			&& (cstack->cs_flags[idx] & CSF_CAUGHT))
2357 		    finish_exception((except_T *)cstack->cs_exception[idx]);
2358 		// Stop at this try conditional - except the try block never
2359 		// got active (because of an inactive surrounding conditional
2360 		// or when the ":try" appeared after an error or interrupt or
2361 		// throw).
2362 		if (cstack->cs_flags[idx] & CSF_TRUE)
2363 		{
2364 		    if (searched_cond == 0 && !inclusive)
2365 			break;
2366 		    stop = TRUE;
2367 		}
2368 	    }
2369 	}
2370 
2371 	// Stop on the searched conditional type (even when the surrounding
2372 	// conditional is not active or something has been made pending).
2373 	// If "inclusive" is TRUE and "searched_cond" is CSF_TRY|CSF_SILENT,
2374 	// check first whether "emsg_silent" needs to be restored.
2375 	if (cstack->cs_flags[idx] & searched_cond)
2376 	{
2377 	    if (!inclusive)
2378 		break;
2379 	    stop = TRUE;
2380 	}
2381 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
2382 	if (stop && searched_cond != (CSF_TRY | CSF_SILENT))
2383 	    break;
2384 
2385 	/*
2386 	 * When leaving a try conditional that reset "emsg_silent" on its
2387 	 * entry after saving the original value, restore that value here and
2388 	 * free the memory used to store it.
2389 	 */
2390 	if ((cstack->cs_flags[idx] & CSF_TRY)
2391 		&& (cstack->cs_flags[idx] & CSF_SILENT))
2392 	{
2393 	    eslist_T	*elem;
2394 
2395 	    elem = cstack->cs_emsg_silent_list;
2396 	    cstack->cs_emsg_silent_list = elem->next;
2397 	    emsg_silent = elem->saved_emsg_silent;
2398 	    vim_free(elem);
2399 	    cstack->cs_flags[idx] &= ~CSF_SILENT;
2400 	}
2401 	if (stop)
2402 	    break;
2403     }
2404     return idx;
2405 }
2406 
2407 /*
2408  * Return an appropriate error message for a missing endwhile/endfor/endif.
2409  */
2410    static char *
2411 get_end_emsg(cstack_T *cstack)
2412 {
2413     if (cstack->cs_flags[cstack->cs_idx] & CSF_WHILE)
2414 	return _(e_endwhile);
2415     if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2416 	return _(e_endfor);
2417     return _(e_endif);
2418 }
2419 
2420 
2421 /*
2422  * Rewind conditionals until index "idx" is reached.  "cond_type" and
2423  * "cond_level" specify a conditional type and the address of a level variable
2424  * which is to be decremented with each skipped conditional of the specified
2425  * type.
2426  * Also free "for info" structures where needed.
2427  */
2428     void
2429 rewind_conditionals(
2430     cstack_T   *cstack,
2431     int		idx,
2432     int		cond_type,
2433     int		*cond_level)
2434 {
2435     while (cstack->cs_idx > idx)
2436     {
2437 	if (cstack->cs_flags[cstack->cs_idx] & cond_type)
2438 	    --*cond_level;
2439 	if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2440 	    free_for_info(cstack->cs_forinfo[cstack->cs_idx]);
2441 	leave_block(cstack);
2442     }
2443 }
2444 
2445 /*
2446  * ":endfunction" when not after a ":function"
2447  */
2448     void
2449 ex_endfunction(exarg_T *eap)
2450 {
2451     if (eap->cmdidx == CMD_enddef)
2452 	emsg(_("E193: :enddef not inside a function"));
2453     else
2454 	emsg(_("E193: :endfunction not inside a function"));
2455 }
2456 
2457 /*
2458  * Return TRUE if the string "p" looks like a ":while" or ":for" command.
2459  */
2460     int
2461 has_loop_cmd(char_u *p)
2462 {
2463     int		len;
2464 
2465     // skip modifiers, white space and ':'
2466     for (;;)
2467     {
2468 	while (*p == ' ' || *p == '\t' || *p == ':')
2469 	    ++p;
2470 	len = modifier_len(p);
2471 	if (len == 0)
2472 	    break;
2473 	p += len;
2474     }
2475     if ((p[0] == 'w' && p[1] == 'h')
2476 	    || (p[0] == 'f' && p[1] == 'o' && p[2] == 'r'))
2477 	return TRUE;
2478     return FALSE;
2479 }
2480 
2481 #endif // FEAT_EVAL
2482