xref: /vim-8.2.3635/src/ex_eval.c (revision fbbcd003)
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 		}
296 	    }
297 	}
298 	return TRUE;
299     }
300 }
301 
302 /*
303  * Free a "msg_list" and the messages it contains.
304  */
305     static void
306 free_msglist(msglist_T *l)
307 {
308     msglist_T  *messages, *next;
309 
310     messages = l;
311     while (messages != NULL)
312     {
313 	next = messages->next;
314 	vim_free(messages->msg);
315 	vim_free(messages->sfile);
316 	vim_free(messages);
317 	messages = next;
318     }
319 }
320 
321 /*
322  * Free global "*msg_list" and the messages it contains, then set "*msg_list"
323  * to NULL.
324  */
325     void
326 free_global_msglist(void)
327 {
328     free_msglist(*msg_list);
329     *msg_list = NULL;
330 }
331 
332 /*
333  * Throw the message specified in the call to cause_errthrow() above as an
334  * error exception.  If cstack is NULL, postpone the throw until do_cmdline()
335  * has returned (see do_one_cmd()).
336  */
337     void
338 do_errthrow(cstack_T *cstack, char_u *cmdname)
339 {
340     /*
341      * Ensure that all commands in nested function calls and sourced files
342      * are aborted immediately.
343      */
344     if (cause_abort)
345     {
346 	cause_abort = FALSE;
347 	force_abort = TRUE;
348     }
349 
350     // If no exception is to be thrown or the conversion should be done after
351     // returning to a previous invocation of do_one_cmd(), do nothing.
352     if (msg_list == NULL || *msg_list == NULL)
353 	return;
354 
355     if (throw_exception(*msg_list, ET_ERROR, cmdname) == FAIL)
356 	free_msglist(*msg_list);
357     else
358     {
359 	if (cstack != NULL)
360 	    do_throw(cstack);
361 	else
362 	    need_rethrow = TRUE;
363     }
364     *msg_list = NULL;
365 }
366 
367 /*
368  * do_intthrow(): Replace the current exception by an interrupt or interrupt
369  * exception if appropriate.  Return TRUE if the current exception is discarded,
370  * FALSE otherwise.
371  */
372     int
373 do_intthrow(cstack_T *cstack)
374 {
375     /*
376      * If no interrupt occurred or no try conditional is active and no exception
377      * is being thrown, do nothing (for compatibility of non-EH scripts).
378      */
379     if (!got_int || (trylevel == 0 && !did_throw))
380 	return FALSE;
381 
382 #ifdef THROW_TEST	// avoid warning for condition always true
383     if (!THROW_ON_INTERRUPT)
384     {
385 	/*
386 	 * The interrupt aborts everything except for executing finally clauses.
387 	 * Discard any user or error or interrupt exception currently being
388 	 * thrown.
389 	 */
390 	if (did_throw)
391 	    discard_current_exception();
392     }
393     else
394 #endif
395     {
396 	/*
397 	 * Throw an interrupt exception, so that everything will be aborted
398 	 * (except for executing finally clauses), until the interrupt exception
399 	 * is caught; if still uncaught at the top level, the script processing
400 	 * will be terminated then.  -  If an interrupt exception is already
401 	 * being thrown, do nothing.
402 	 *
403 	 */
404 	if (did_throw)
405 	{
406 	    if (current_exception->type == ET_INTERRUPT)
407 		return FALSE;
408 
409 	    // An interrupt exception replaces any user or error exception.
410 	    discard_current_exception();
411 	}
412 	if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) != FAIL)
413 	    do_throw(cstack);
414     }
415 
416     return TRUE;
417 }
418 
419 /*
420  * Get an exception message that is to be stored in current_exception->value.
421  */
422     char *
423 get_exception_string(
424     void	*value,
425     except_type_T type,
426     char_u	*cmdname,
427     int		*should_free)
428 {
429     char	*ret;
430     char	*mesg;
431     int		cmdlen;
432     char	*p, *val;
433 
434     if (type == ET_ERROR)
435     {
436 	*should_free = TRUE;
437 	mesg = ((msglist_T *)value)->throw_msg;
438 	if (cmdname != NULL && *cmdname != NUL)
439 	{
440 	    cmdlen = (int)STRLEN(cmdname);
441 	    ret = (char *)vim_strnsave((char_u *)"Vim(",
442 						4 + cmdlen + 2 + STRLEN(mesg));
443 	    if (ret == NULL)
444 		return ret;
445 	    STRCPY(&ret[4], cmdname);
446 	    STRCPY(&ret[4 + cmdlen], "):");
447 	    val = ret + 4 + cmdlen + 2;
448 	}
449 	else
450 	{
451 	    ret = (char *)vim_strnsave((char_u *)"Vim:", 4 + STRLEN(mesg));
452 	    if (ret == NULL)
453 		return ret;
454 	    val = ret + 4;
455 	}
456 
457 	// msg_add_fname may have been used to prefix the message with a file
458 	// name in quotes.  In the exception value, put the file name in
459 	// parentheses and move it to the end.
460 	for (p = mesg; ; p++)
461 	{
462 	    if (*p == NUL
463 		    || (*p == 'E'
464 			&& VIM_ISDIGIT(p[1])
465 			&& (p[2] == ':'
466 			    || (VIM_ISDIGIT(p[2])
467 				&& (p[3] == ':'
468 				    || (VIM_ISDIGIT(p[3])
469 					&& p[4] == ':'))))))
470 	    {
471 		if (*p == NUL || p == mesg)
472 		    STRCAT(val, mesg);  // 'E123' missing or at beginning
473 		else
474 		{
475 		    // '"filename" E123: message text'
476 		    if (mesg[0] != '"' || p-2 < &mesg[1] ||
477 			    p[-2] != '"' || p[-1] != ' ')
478 			// "E123:" is part of the file name.
479 			continue;
480 
481 		    STRCAT(val, p);
482 		    p[-2] = NUL;
483 		    sprintf((char *)(val + STRLEN(p)), " (%s)", &mesg[1]);
484 		    p[-2] = '"';
485 		}
486 		break;
487 	    }
488 	}
489     }
490     else
491     {
492 	*should_free = FALSE;
493 	ret = value;
494     }
495 
496     return ret;
497 }
498 
499 
500 /*
501  * Throw a new exception.  Return FAIL when out of memory or it was tried to
502  * throw an illegal user exception.  "value" is the exception string for a
503  * user or interrupt exception, or points to a message list in case of an
504  * error exception.
505  */
506     int
507 throw_exception(void *value, except_type_T type, char_u *cmdname)
508 {
509     except_T	*excp;
510     int		should_free;
511 
512     /*
513      * Disallow faking Interrupt or error exceptions as user exceptions.  They
514      * would be treated differently from real interrupt or error exceptions
515      * when no active try block is found, see do_cmdline().
516      */
517     if (type == ET_USER)
518     {
519 	if (STRNCMP((char_u *)value, "Vim", 3) == 0
520 		&& (((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':'
521 		    || ((char_u *)value)[3] == '('))
522 	{
523 	    emsg(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
524 	    goto fail;
525 	}
526     }
527 
528     excp = ALLOC_ONE(except_T);
529     if (excp == NULL)
530 	goto nomem;
531 
532     if (type == ET_ERROR)
533 	// Store the original message and prefix the exception value with
534 	// "Vim:" or, if a command name is given, "Vim(cmdname):".
535 	excp->messages = (msglist_T *)value;
536 
537     excp->value = get_exception_string(value, type, cmdname, &should_free);
538     if (excp->value == NULL && should_free)
539 	goto nomem;
540 
541     excp->type = type;
542     if (type == ET_ERROR && ((msglist_T *)value)->sfile != NULL)
543     {
544 	msglist_T *entry = (msglist_T *)value;
545 
546 	excp->throw_name = entry->sfile;
547 	entry->sfile = NULL;
548 	excp->throw_lnum = entry->slnum;
549     }
550     else
551     {
552 	excp->throw_name = estack_sfile(ESTACK_NONE);
553 	if (excp->throw_name == NULL)
554 	    excp->throw_name = vim_strsave((char_u *)"");
555 	if (excp->throw_name == NULL)
556 	{
557 	    if (should_free)
558 		vim_free(excp->value);
559 	    goto nomem;
560 	}
561 	excp->throw_lnum = SOURCING_LNUM;
562     }
563 
564     if (p_verbose >= 13 || debug_break_level > 0)
565     {
566 	int	save_msg_silent = msg_silent;
567 
568 	if (debug_break_level > 0)
569 	    msg_silent = FALSE;		// display messages
570 	else
571 	    verbose_enter();
572 	++no_wait_return;
573 	if (debug_break_level > 0 || *p_vfile == NUL)
574 	    msg_scroll = TRUE;	    // always scroll up, don't overwrite
575 
576 	smsg(_("Exception thrown: %s"), excp->value);
577 	msg_puts("\n");   // don't overwrite this either
578 
579 	if (debug_break_level > 0 || *p_vfile == NUL)
580 	    cmdline_row = msg_row;
581 	--no_wait_return;
582 	if (debug_break_level > 0)
583 	    msg_silent = save_msg_silent;
584 	else
585 	    verbose_leave();
586     }
587 
588     current_exception = excp;
589     return OK;
590 
591 nomem:
592     vim_free(excp);
593     suppress_errthrow = TRUE;
594     emsg(_(e_outofmem));
595 fail:
596     current_exception = NULL;
597     return FAIL;
598 }
599 
600 /*
601  * Discard an exception.  "was_finished" is set when the exception has been
602  * caught and the catch clause has been ended normally.
603  */
604     static void
605 discard_exception(except_T *excp, int was_finished)
606 {
607     char_u		*saved_IObuff;
608 
609     if (excp == NULL)
610     {
611 	internal_error("discard_exception()");
612 	return;
613     }
614 
615     if (p_verbose >= 13 || debug_break_level > 0)
616     {
617 	int	save_msg_silent = msg_silent;
618 
619 	saved_IObuff = vim_strsave(IObuff);
620 	if (debug_break_level > 0)
621 	    msg_silent = FALSE;		// display messages
622 	else
623 	    verbose_enter();
624 	++no_wait_return;
625 	if (debug_break_level > 0 || *p_vfile == NUL)
626 	    msg_scroll = TRUE;	    // always scroll up, don't overwrite
627 	smsg(was_finished
628 		    ? _("Exception finished: %s")
629 		    : _("Exception discarded: %s"),
630 		excp->value);
631 	msg_puts("\n");   // don't overwrite this either
632 	if (debug_break_level > 0 || *p_vfile == NUL)
633 	    cmdline_row = msg_row;
634 	--no_wait_return;
635 	if (debug_break_level > 0)
636 	    msg_silent = save_msg_silent;
637 	else
638 	    verbose_leave();
639 	STRCPY(IObuff, saved_IObuff);
640 	vim_free(saved_IObuff);
641     }
642     if (excp->type != ET_INTERRUPT)
643 	vim_free(excp->value);
644     if (excp->type == ET_ERROR)
645 	free_msglist(excp->messages);
646     vim_free(excp->throw_name);
647     vim_free(excp);
648 }
649 
650 /*
651  * Discard the exception currently being thrown.
652  */
653     void
654 discard_current_exception(void)
655 {
656     if (current_exception != NULL)
657     {
658 	discard_exception(current_exception, FALSE);
659 	current_exception = NULL;
660     }
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())
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 }
925 
926     static void
927 leave_block(cstack_T *cstack)
928 {
929     if (in_vim9script() && SCRIPT_ID_VALID(current_sctx.sc_sid))
930     {
931 	scriptitem_T	*si = SCRIPT_ITEM(current_sctx.sc_sid);
932 	int		i;
933 
934 	for (i = cstack->cs_script_var_len[cstack->cs_idx];
935 					       i < si->sn_var_vals.ga_len; ++i)
936 	{
937 	    svar_T	*sv = ((svar_T *)si->sn_var_vals.ga_data) + i;
938 
939 	    if (sv->sv_name != NULL)
940 		// Remove a variable declared inside the block, if it still
941 		// exists, from sn_vars and move the value into sn_all_vars.
942 		hide_script_var(si, i);
943 	}
944 
945 	// TODO: is this needed?
946 	cstack->cs_script_var_len[cstack->cs_idx] = si->sn_var_vals.ga_len;
947 
948 	if (cstack->cs_idx == 0)
949 	    si->sn_current_block_id = 0;
950 	else
951 	    si->sn_current_block_id = cstack->cs_block_id[cstack->cs_idx - 1];
952     }
953     --cstack->cs_idx;
954 }
955 
956 /*
957  * ":if".
958  */
959     void
960 ex_if(exarg_T *eap)
961 {
962     int		error;
963     int		skip;
964     int		result;
965     cstack_T	*cstack = eap->cstack;
966 
967     if (cstack->cs_idx == CSTACK_LEN - 1)
968 	eap->errmsg = _("E579: :if nesting too deep");
969     else
970     {
971 	enter_block(cstack);
972 	cstack->cs_flags[cstack->cs_idx] = 0;
973 
974 	/*
975 	 * Don't do something after an error, interrupt, or throw, or when
976 	 * there is a surrounding conditional and it was not active.
977 	 */
978 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
979 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
980 
981 	result = eval_to_bool(eap->arg, &error, eap, skip);
982 
983 	if (!skip && !error)
984 	{
985 	    if (result)
986 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
987 	}
988 	else
989 	    // set TRUE, so this conditional will never get active
990 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
991     }
992 }
993 
994 /*
995  * ":endif".
996  */
997     void
998 ex_endif(exarg_T *eap)
999 {
1000     cstack_T	*cstack = eap->cstack;
1001 
1002     did_endif = TRUE;
1003     if (cstack->cs_idx < 0
1004 	    || (cstack->cs_flags[cstack->cs_idx]
1005 				& (CSF_WHILE | CSF_FOR | CSF_TRY | CSF_BLOCK)))
1006 	eap->errmsg = _(e_endif_without_if);
1007     else
1008     {
1009 	/*
1010 	 * When debugging or a breakpoint was encountered, display the debug
1011 	 * prompt (if not already done).  This shows the user that an ":endif"
1012 	 * is executed when the ":if" or a previous ":elseif" was not TRUE.
1013 	 * Handle a ">quit" debug command as if an interrupt had occurred before
1014 	 * the ":endif".  That is, throw an interrupt exception if appropriate.
1015 	 * Doing this here prevents an exception for a parsing error being
1016 	 * discarded by throwing the interrupt exception later on.
1017 	 */
1018 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE)
1019 						    && dbg_check_skipped(eap))
1020 	    (void)do_intthrow(cstack);
1021 
1022 	leave_block(cstack);
1023     }
1024 }
1025 
1026 /*
1027  * ":else" and ":elseif".
1028  */
1029     void
1030 ex_else(exarg_T *eap)
1031 {
1032     int		error;
1033     int		skip;
1034     int		result;
1035     cstack_T	*cstack = eap->cstack;
1036 
1037     /*
1038      * Don't do something after an error, interrupt, or throw, or when there is
1039      * a surrounding conditional and it was not active.
1040      */
1041     skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1042 	    && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1043 
1044     if (cstack->cs_idx < 0
1045 	    || (cstack->cs_flags[cstack->cs_idx]
1046 				& (CSF_WHILE | CSF_FOR | CSF_TRY | CSF_BLOCK)))
1047     {
1048 	if (eap->cmdidx == CMD_else)
1049 	{
1050 	    eap->errmsg = _(e_else_without_if);
1051 	    return;
1052 	}
1053 	eap->errmsg = _(e_elseif_without_if);
1054 	skip = TRUE;
1055     }
1056     else if (cstack->cs_flags[cstack->cs_idx] & CSF_ELSE)
1057     {
1058 	if (eap->cmdidx == CMD_else)
1059 	{
1060 	    eap->errmsg = _("E583: multiple :else");
1061 	    return;
1062 	}
1063 	eap->errmsg = _("E584: :elseif after :else");
1064 	skip = TRUE;
1065     }
1066 
1067     // if skipping or the ":if" was TRUE, reset ACTIVE, otherwise set it
1068     if (skip || cstack->cs_flags[cstack->cs_idx] & CSF_TRUE)
1069     {
1070 	if (eap->errmsg == NULL)
1071 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1072 	skip = TRUE;	// don't evaluate an ":elseif"
1073     }
1074     else
1075 	cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE;
1076 
1077     /*
1078      * When debugging or a breakpoint was encountered, display the debug prompt
1079      * (if not already done).  This shows the user that an ":else" or ":elseif"
1080      * is executed when the ":if" or previous ":elseif" was not TRUE.  Handle
1081      * a ">quit" debug command as if an interrupt had occurred before the
1082      * ":else" or ":elseif".  That is, set "skip" and throw an interrupt
1083      * exception if appropriate.  Doing this here prevents that an exception
1084      * for a parsing errors is discarded when throwing the interrupt exception
1085      * later on.
1086      */
1087     if (!skip && dbg_check_skipped(eap) && got_int)
1088     {
1089 	(void)do_intthrow(cstack);
1090 	skip = TRUE;
1091     }
1092 
1093     if (eap->cmdidx == CMD_elseif)
1094     {
1095 	result = eval_to_bool(eap->arg, &error, eap, skip);
1096 
1097 	// When throwing error exceptions, we want to throw always the first
1098 	// of several errors in a row.  This is what actually happens when
1099 	// a conditional error was detected above and there is another failure
1100 	// when parsing the expression.  Since the skip flag is set in this
1101 	// case, the parsing error will be ignored by emsg().
1102 	if (!skip && !error)
1103 	{
1104 	    if (result)
1105 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
1106 	    else
1107 		cstack->cs_flags[cstack->cs_idx] = 0;
1108 	}
1109 	else if (eap->errmsg == NULL)
1110 	    // set TRUE, so this conditional will never get active
1111 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1112     }
1113     else
1114 	cstack->cs_flags[cstack->cs_idx] |= CSF_ELSE;
1115 }
1116 
1117 /*
1118  * Handle ":while" and ":for".
1119  */
1120     void
1121 ex_while(exarg_T *eap)
1122 {
1123     int		error;
1124     int		skip;
1125     int		result;
1126     cstack_T	*cstack = eap->cstack;
1127 
1128     if (cstack->cs_idx == CSTACK_LEN - 1)
1129 	eap->errmsg = _("E585: :while/:for nesting too deep");
1130     else
1131     {
1132 	/*
1133 	 * The loop flag is set when we have jumped back from the matching
1134 	 * ":endwhile" or ":endfor".  When not set, need to initialise this
1135 	 * cstack entry.
1136 	 */
1137 	if ((cstack->cs_lflags & CSL_HAD_LOOP) == 0)
1138 	{
1139 	    enter_block(cstack);
1140 	    ++cstack->cs_looplevel;
1141 	    cstack->cs_line[cstack->cs_idx] = -1;
1142 	}
1143 	cstack->cs_flags[cstack->cs_idx] =
1144 			       eap->cmdidx == CMD_while ? CSF_WHILE : CSF_FOR;
1145 
1146 	/*
1147 	 * Don't do something after an error, interrupt, or throw, or when
1148 	 * there is a surrounding conditional and it was not active.
1149 	 */
1150 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1151 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1152 	if (eap->cmdidx == CMD_while)
1153 	{
1154 	    /*
1155 	     * ":while bool-expr"
1156 	     */
1157 	    result = eval_to_bool(eap->arg, &error, eap, skip);
1158 	}
1159 	else
1160 	{
1161 	    void	*fi;
1162 	    evalarg_T	evalarg;
1163 
1164 	    CLEAR_FIELD(evalarg);
1165 	    evalarg.eval_flags = skip ? 0 : EVAL_EVALUATE;
1166 	    if (getline_equal(eap->getline, eap->cookie, getsourceline))
1167 	    {
1168 		evalarg.eval_getline = eap->getline;
1169 		evalarg.eval_cookie = eap->cookie;
1170 	    }
1171 
1172 	    /*
1173 	     * ":for var in list-expr"
1174 	     */
1175 	    if ((cstack->cs_lflags & CSL_HAD_LOOP) != 0)
1176 	    {
1177 		// Jumping here from a ":continue" or ":endfor": use the
1178 		// previously evaluated list.
1179 		fi = cstack->cs_forinfo[cstack->cs_idx];
1180 		error = FALSE;
1181 
1182 		// the "in expr" is not used, skip over it
1183 		skip_for_lines(fi, &evalarg);
1184 	    }
1185 	    else
1186 	    {
1187 		// Evaluate the argument and get the info in a structure.
1188 		fi = eval_for_line(eap->arg, &error, eap, &evalarg);
1189 		cstack->cs_forinfo[cstack->cs_idx] = fi;
1190 	    }
1191 
1192 	    // use the element at the start of the list and advance
1193 	    if (!error && fi != NULL && !skip)
1194 		result = next_for_item(fi, eap->arg);
1195 	    else
1196 		result = FALSE;
1197 
1198 	    if (!result)
1199 	    {
1200 		free_for_info(fi);
1201 		cstack->cs_forinfo[cstack->cs_idx] = NULL;
1202 	    }
1203 	    clear_evalarg(&evalarg, eap);
1204 	}
1205 
1206 	/*
1207 	 * If this cstack entry was just initialised and is active, set the
1208 	 * loop flag, so do_cmdline() will set the line number in cs_line[].
1209 	 * If executing the command a second time, clear the loop flag.
1210 	 */
1211 	if (!skip && !error && result)
1212 	{
1213 	    cstack->cs_flags[cstack->cs_idx] |= (CSF_ACTIVE | CSF_TRUE);
1214 	    cstack->cs_lflags ^= CSL_HAD_LOOP;
1215 	}
1216 	else
1217 	{
1218 	    cstack->cs_lflags &= ~CSL_HAD_LOOP;
1219 	    // If the ":while" evaluates to FALSE or ":for" is past the end of
1220 	    // the list, show the debug prompt at the ":endwhile"/":endfor" as
1221 	    // if there was a ":break" in a ":while"/":for" evaluating to
1222 	    // TRUE.
1223 	    if (!skip && !error)
1224 		cstack->cs_flags[cstack->cs_idx] |= CSF_TRUE;
1225 	}
1226     }
1227 }
1228 
1229 /*
1230  * ":continue"
1231  */
1232     void
1233 ex_continue(exarg_T *eap)
1234 {
1235     int		idx;
1236     cstack_T	*cstack = eap->cstack;
1237 
1238     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1239 	eap->errmsg = _(e_continue);
1240     else
1241     {
1242 	// Try to find the matching ":while".  This might stop at a try
1243 	// conditional not in its finally clause (which is then to be executed
1244 	// next).  Therefor, inactivate all conditionals except the ":while"
1245 	// itself (if reached).
1246 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1247 	if (idx >= 0 && (cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1248 	{
1249 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1250 
1251 	    /*
1252 	     * Set CSL_HAD_CONT, so do_cmdline() will jump back to the
1253 	     * matching ":while".
1254 	     */
1255 	    cstack->cs_lflags |= CSL_HAD_CONT;	// let do_cmdline() handle it
1256 	}
1257 	else
1258 	{
1259 	    // If a try conditional not in its finally clause is reached first,
1260 	    // make the ":continue" pending for execution at the ":endtry".
1261 	    cstack->cs_pending[idx] = CSTP_CONTINUE;
1262 	    report_make_pending(CSTP_CONTINUE, NULL);
1263 	}
1264     }
1265 }
1266 
1267 /*
1268  * ":break"
1269  */
1270     void
1271 ex_break(exarg_T *eap)
1272 {
1273     int		idx;
1274     cstack_T	*cstack = eap->cstack;
1275 
1276     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1277 	eap->errmsg = _(e_break);
1278     else
1279     {
1280 	// Inactivate conditionals until the matching ":while" or a try
1281 	// conditional not in its finally clause (which is then to be
1282 	// executed next) is found.  In the latter case, make the ":break"
1283 	// pending for execution at the ":endtry".
1284 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, TRUE);
1285 	if (idx >= 0 && !(cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1286 	{
1287 	    cstack->cs_pending[idx] = CSTP_BREAK;
1288 	    report_make_pending(CSTP_BREAK, NULL);
1289 	}
1290     }
1291 }
1292 
1293 /*
1294  * ":endwhile" and ":endfor"
1295  */
1296     void
1297 ex_endwhile(exarg_T *eap)
1298 {
1299     cstack_T	*cstack = eap->cstack;
1300     int		idx;
1301     char	*err;
1302     int		csf;
1303     int		fl;
1304 
1305     if (eap->cmdidx == CMD_endwhile)
1306     {
1307 	err = e_while;
1308 	csf = CSF_WHILE;
1309     }
1310     else
1311     {
1312 	err = e_for;
1313 	csf = CSF_FOR;
1314     }
1315 
1316     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1317 	eap->errmsg = _(err);
1318     else
1319     {
1320 	fl =  cstack->cs_flags[cstack->cs_idx];
1321 	if (!(fl & csf))
1322 	{
1323 	    // If we are in a ":while" or ":for" but used the wrong endloop
1324 	    // command, do not rewind to the next enclosing ":for"/":while".
1325 	    if (fl & CSF_WHILE)
1326 		eap->errmsg = _("E732: Using :endfor with :while");
1327 	    else if (fl & CSF_FOR)
1328 		eap->errmsg = _("E733: Using :endwhile with :for");
1329 	}
1330 	if (!(fl & (CSF_WHILE | CSF_FOR)))
1331 	{
1332 	    if (!(fl & CSF_TRY))
1333 		eap->errmsg = _(e_endif);
1334 	    else if (fl & CSF_FINALLY)
1335 		eap->errmsg = _(e_endtry);
1336 	    // Try to find the matching ":while" and report what's missing.
1337 	    for (idx = cstack->cs_idx; idx > 0; --idx)
1338 	    {
1339 		fl =  cstack->cs_flags[idx];
1340 		if ((fl & CSF_TRY) && !(fl & CSF_FINALLY))
1341 		{
1342 		    // Give up at a try conditional not in its finally clause.
1343 		    // Ignore the ":endwhile"/":endfor".
1344 		    eap->errmsg = _(err);
1345 		    return;
1346 		}
1347 		if (fl & csf)
1348 		    break;
1349 	    }
1350 	    // Cleanup and rewind all contained (and unclosed) conditionals.
1351 	    (void)cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1352 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1353 	}
1354 
1355 	/*
1356 	 * When debugging or a breakpoint was encountered, display the debug
1357 	 * prompt (if not already done).  This shows the user that an
1358 	 * ":endwhile"/":endfor" is executed when the ":while" was not TRUE or
1359 	 * after a ":break".  Handle a ">quit" debug command as if an
1360 	 * interrupt had occurred before the ":endwhile"/":endfor".  That is,
1361 	 * throw an interrupt exception if appropriate.  Doing this here
1362 	 * prevents that an exception for a parsing error is discarded when
1363 	 * throwing the interrupt exception later on.
1364 	 */
1365 	else if (cstack->cs_flags[cstack->cs_idx] & CSF_TRUE
1366 		&& !(cstack->cs_flags[cstack->cs_idx] & CSF_ACTIVE)
1367 		&& dbg_check_skipped(eap))
1368 	    (void)do_intthrow(cstack);
1369 
1370 	/*
1371 	 * Set loop flag, so do_cmdline() will jump back to the matching
1372 	 * ":while" or ":for".
1373 	 */
1374 	cstack->cs_lflags |= CSL_HAD_ENDLOOP;
1375     }
1376 }
1377 
1378 /*
1379  * "{" start of a block in Vim9 script
1380  */
1381     void
1382 ex_block(exarg_T *eap)
1383 {
1384     cstack_T	*cstack = eap->cstack;
1385 
1386     if (cstack->cs_idx == CSTACK_LEN - 1)
1387 	eap->errmsg = _("E579: block nesting too deep");
1388     else
1389     {
1390 	enter_block(cstack);
1391 	cstack->cs_flags[cstack->cs_idx] = CSF_BLOCK | CSF_ACTIVE | CSF_TRUE;
1392     }
1393 }
1394 
1395 /*
1396  * "}" end of a block in Vim9 script
1397  */
1398     void
1399 ex_endblock(exarg_T *eap)
1400 {
1401     cstack_T	*cstack = eap->cstack;
1402 
1403     if (cstack->cs_idx < 0
1404 	    || (cstack->cs_flags[cstack->cs_idx] & CSF_BLOCK) == 0)
1405 	eap->errmsg = _(e_endblock_without_block);
1406     else
1407 	leave_block(cstack);
1408 }
1409 
1410 /*
1411  * ":throw expr"
1412  */
1413     void
1414 ex_throw(exarg_T *eap)
1415 {
1416     char_u	*arg = eap->arg;
1417     char_u	*value;
1418 
1419     if (*arg != NUL && *arg != '|' && *arg != '\n')
1420 	value = eval_to_string_skip(arg, eap, eap->skip);
1421     else
1422     {
1423 	emsg(_(e_argreq));
1424 	value = NULL;
1425     }
1426 
1427     // On error or when an exception is thrown during argument evaluation, do
1428     // not throw.
1429     if (!eap->skip && value != NULL)
1430     {
1431 	if (throw_exception(value, ET_USER, NULL) == FAIL)
1432 	    vim_free(value);
1433 	else
1434 	    do_throw(eap->cstack);
1435     }
1436 }
1437 
1438 /*
1439  * Throw the current exception through the specified cstack.  Common routine
1440  * for ":throw" (user exception) and error and interrupt exceptions.  Also
1441  * used for rethrowing an uncaught exception.
1442  */
1443     void
1444 do_throw(cstack_T *cstack)
1445 {
1446     int		idx;
1447     int		inactivate_try = FALSE;
1448 
1449     /*
1450      * Cleanup and inactivate up to the next surrounding try conditional that
1451      * is not in its finally clause.  Normally, do not inactivate the try
1452      * conditional itself, so that its ACTIVE flag can be tested below.  But
1453      * if a previous error or interrupt has not been converted to an exception,
1454      * inactivate the try conditional, too, as if the conversion had been done,
1455      * and reset the did_emsg or got_int flag, so this won't happen again at
1456      * the next surrounding try conditional.
1457      */
1458 #ifndef THROW_ON_ERROR_TRUE
1459     if (did_emsg && !THROW_ON_ERROR)
1460     {
1461 	inactivate_try = TRUE;
1462 	did_emsg = FALSE;
1463     }
1464 #endif
1465 #ifndef THROW_ON_INTERRUPT_TRUE
1466     if (got_int && !THROW_ON_INTERRUPT)
1467     {
1468 	inactivate_try = TRUE;
1469 	got_int = FALSE;
1470     }
1471 #endif
1472     idx = cleanup_conditionals(cstack, 0, inactivate_try);
1473     if (idx >= 0)
1474     {
1475 	/*
1476 	 * If this try conditional is active and we are before its first
1477 	 * ":catch", set THROWN so that the ":catch" commands will check
1478 	 * whether the exception matches.  When the exception came from any of
1479 	 * the catch clauses, it will be made pending at the ":finally" (if
1480 	 * present) and rethrown at the ":endtry".  This will also happen if
1481 	 * the try conditional is inactive.  This is the case when we are
1482 	 * throwing an exception due to an error or interrupt on the way from
1483 	 * a preceding ":continue", ":break", ":return", ":finish", error or
1484 	 * interrupt (not converted to an exception) to the finally clause or
1485 	 * from a preceding throw of a user or error or interrupt exception to
1486 	 * the matching catch clause or the finally clause.
1487 	 */
1488 	if (!(cstack->cs_flags[idx] & CSF_CAUGHT))
1489 	{
1490 	    if (cstack->cs_flags[idx] & CSF_ACTIVE)
1491 		cstack->cs_flags[idx] |= CSF_THROWN;
1492 	    else
1493 		// THROWN may have already been set for a catchable exception
1494 		// that has been discarded.  Ensure it is reset for the new
1495 		// exception.
1496 		cstack->cs_flags[idx] &= ~CSF_THROWN;
1497 	}
1498 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
1499 	cstack->cs_exception[idx] = current_exception;
1500     }
1501 #if 0
1502     // TODO: Add optimization below.  Not yet done because of interface
1503     // problems to eval.c and ex_cmds2.c. (Servatius)
1504     else
1505     {
1506 	/*
1507 	 * There are no catch clauses to check or finally clauses to execute.
1508 	 * End the current script or function.  The exception will be rethrown
1509 	 * in the caller.
1510 	 */
1511 	if (getline_equal(eap->getline, eap->cookie, get_func_line))
1512 	    current_funccal->returned = TRUE;
1513 	elseif (eap->get_func_line == getsourceline)
1514 	    ((struct source_cookie *)eap->cookie)->finished = TRUE;
1515     }
1516 #endif
1517 
1518     did_throw = TRUE;
1519 }
1520 
1521 /*
1522  * ":try"
1523  */
1524     void
1525 ex_try(exarg_T *eap)
1526 {
1527     int		skip;
1528     cstack_T	*cstack = eap->cstack;
1529 
1530     if (cstack->cs_idx == CSTACK_LEN - 1)
1531 	eap->errmsg = _("E601: :try nesting too deep");
1532     else
1533     {
1534 	enter_block(cstack);
1535 	++cstack->cs_trylevel;
1536 	cstack->cs_flags[cstack->cs_idx] = CSF_TRY;
1537 	cstack->cs_pending[cstack->cs_idx] = CSTP_NONE;
1538 
1539 	/*
1540 	 * Don't do something after an error, interrupt, or throw, or when there
1541 	 * is a surrounding conditional and it was not active.
1542 	 */
1543 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1544 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1545 
1546 	if (!skip)
1547 	{
1548 	    // Set ACTIVE and TRUE.  TRUE means that the corresponding ":catch"
1549 	    // commands should check for a match if an exception is thrown and
1550 	    // that the finally clause needs to be executed.
1551 	    cstack->cs_flags[cstack->cs_idx] |= CSF_ACTIVE | CSF_TRUE;
1552 
1553 	    /*
1554 	     * ":silent!", even when used in a try conditional, disables
1555 	     * displaying of error messages and conversion of errors to
1556 	     * exceptions.  When the silent commands again open a try
1557 	     * conditional, save "emsg_silent" and reset it so that errors are
1558 	     * again converted to exceptions.  The value is restored when that
1559 	     * try conditional is left.  If it is left normally, the commands
1560 	     * following the ":endtry" are again silent.  If it is left by
1561 	     * a ":continue", ":break", ":return", or ":finish", the commands
1562 	     * executed next are again silent.  If it is left due to an
1563 	     * aborting error, an interrupt, or an exception, restoring
1564 	     * "emsg_silent" does not matter since we are already in the
1565 	     * aborting state and/or the exception has already been thrown.
1566 	     * The effect is then just freeing the memory that was allocated
1567 	     * to save the value.
1568 	     */
1569 	    if (emsg_silent)
1570 	    {
1571 		eslist_T	*elem;
1572 
1573 		elem = ALLOC_ONE(struct eslist_elem);
1574 		if (elem == NULL)
1575 		    emsg(_(e_outofmem));
1576 		else
1577 		{
1578 		    elem->saved_emsg_silent = emsg_silent;
1579 		    elem->next = cstack->cs_emsg_silent_list;
1580 		    cstack->cs_emsg_silent_list = elem;
1581 		    cstack->cs_flags[cstack->cs_idx] |= CSF_SILENT;
1582 		    emsg_silent = 0;
1583 		}
1584 	    }
1585 	}
1586 
1587     }
1588 }
1589 
1590 /*
1591  * ":catch /{pattern}/" and ":catch"
1592  */
1593     void
1594 ex_catch(exarg_T *eap)
1595 {
1596     int		idx = 0;
1597     int		give_up = FALSE;
1598     int		skip = FALSE;
1599     int		caught = FALSE;
1600     char_u	*end;
1601     int		save_char = 0;
1602     char_u	*save_cpo;
1603     regmatch_T	regmatch;
1604     int		prev_got_int;
1605     cstack_T	*cstack = eap->cstack;
1606     char_u	*pat;
1607 
1608     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1609     {
1610 	eap->errmsg = _(e_catch);
1611 	give_up = TRUE;
1612     }
1613     else
1614     {
1615 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1616 	{
1617 	    // Report what's missing if the matching ":try" is not in its
1618 	    // finally clause.
1619 	    eap->errmsg = get_end_emsg(cstack);
1620 	    skip = TRUE;
1621 	}
1622 	for (idx = cstack->cs_idx; idx > 0; --idx)
1623 	    if (cstack->cs_flags[idx] & CSF_TRY)
1624 		break;
1625 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1626 	{
1627 	    // Give up for a ":catch" after ":finally" and ignore it.
1628 	    // Just parse.
1629 	    eap->errmsg = _("E604: :catch after :finally");
1630 	    give_up = TRUE;
1631 	}
1632 	else
1633 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1634 						       &cstack->cs_looplevel);
1635     }
1636 
1637     if (ends_excmd2(eap->cmd, eap->arg))   // no argument, catch all errors
1638     {
1639 	pat = (char_u *)".*";
1640 	end = NULL;
1641 	eap->nextcmd = find_nextcmd(eap->arg);
1642     }
1643     else
1644     {
1645 	pat = eap->arg + 1;
1646 	end = skip_regexp_err(pat, *eap->arg, TRUE);
1647 	if (end == NULL)
1648 	    give_up = TRUE;
1649     }
1650 
1651     if (!give_up)
1652     {
1653 	/*
1654 	 * Don't do something when no exception has been thrown or when the
1655 	 * corresponding try block never got active (because of an inactive
1656 	 * surrounding conditional or after an error or interrupt or throw).
1657 	 */
1658 	if (!did_throw || !(cstack->cs_flags[idx] & CSF_TRUE))
1659 	    skip = TRUE;
1660 
1661 	/*
1662 	 * Check for a match only if an exception is thrown but not caught by
1663 	 * a previous ":catch".  An exception that has replaced a discarded
1664 	 * exception is not checked (THROWN is not set then).
1665 	 */
1666 	if (!skip && (cstack->cs_flags[idx] & CSF_THROWN)
1667 		&& !(cstack->cs_flags[idx] & CSF_CAUGHT))
1668 	{
1669 	    if (end != NULL && *end != NUL
1670 				      && !ends_excmd2(end, skipwhite(end + 1)))
1671 	    {
1672 		semsg(_(e_trailing_arg), end);
1673 		return;
1674 	    }
1675 
1676 	    // When debugging or a breakpoint was encountered, display the
1677 	    // debug prompt (if not already done) before checking for a match.
1678 	    // This is a helpful hint for the user when the regular expression
1679 	    // matching fails.  Handle a ">quit" debug command as if an
1680 	    // interrupt had occurred before the ":catch".  That is, discard
1681 	    // the original exception, replace it by an interrupt exception,
1682 	    // and don't catch it in this try block.
1683 	    if (!dbg_check_skipped(eap) || !do_intthrow(cstack))
1684 	    {
1685 		// Terminate the pattern and avoid the 'l' flag in 'cpoptions'
1686 		// while compiling it.
1687 		if (end != NULL)
1688 		{
1689 		    save_char = *end;
1690 		    *end = NUL;
1691 		}
1692 		save_cpo  = p_cpo;
1693 		p_cpo = (char_u *)"";
1694 		// Disable error messages, it will make current_exception
1695 		// invalid.
1696 		++emsg_off;
1697 		regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1698 		--emsg_off;
1699 		regmatch.rm_ic = FALSE;
1700 		if (end != NULL)
1701 		    *end = save_char;
1702 		p_cpo = save_cpo;
1703 		if (regmatch.regprog == NULL)
1704 		    semsg(_(e_invarg2), pat);
1705 		else
1706 		{
1707 		    /*
1708 		     * Save the value of got_int and reset it.  We don't want
1709 		     * a previous interruption cancel matching, only hitting
1710 		     * CTRL-C while matching should abort it.
1711 		     */
1712 		    prev_got_int = got_int;
1713 		    got_int = FALSE;
1714 		    caught = vim_regexec_nl(&regmatch,
1715 			       (char_u *)current_exception->value, (colnr_T)0);
1716 		    got_int |= prev_got_int;
1717 		    vim_regfree(regmatch.regprog);
1718 		}
1719 	    }
1720 	}
1721 
1722 	if (caught)
1723 	{
1724 	    // Make this ":catch" clause active and reset did_emsg, got_int,
1725 	    // and did_throw.  Put the exception on the caught stack.
1726 	    cstack->cs_flags[idx] |= CSF_ACTIVE | CSF_CAUGHT;
1727 	    did_emsg = got_int = did_throw = FALSE;
1728 	    catch_exception((except_T *)cstack->cs_exception[idx]);
1729 	    // It's mandatory that the current exception is stored in the cstack
1730 	    // so that it can be discarded at the next ":catch", ":finally", or
1731 	    // ":endtry" or when the catch clause is left by a ":continue",
1732 	    // ":break", ":return", ":finish", error, interrupt, or another
1733 	    // exception.
1734 	    if (cstack->cs_exception[cstack->cs_idx] != current_exception)
1735 		internal_error("ex_catch()");
1736 	}
1737 	else
1738 	{
1739 	    /*
1740 	     * If there is a preceding catch clause and it caught the exception,
1741 	     * finish the exception now.  This happens also after errors except
1742 	     * when this ":catch" was after the ":finally" or not within
1743 	     * a ":try".  Make the try conditional inactive so that the
1744 	     * following catch clauses are skipped.  On an error or interrupt
1745 	     * after the preceding try block or catch clause was left by
1746 	     * a ":continue", ":break", ":return", or ":finish", discard the
1747 	     * pending action.
1748 	     */
1749 	    cleanup_conditionals(cstack, CSF_TRY, TRUE);
1750 	}
1751     }
1752 
1753     if (end != NULL)
1754 	eap->nextcmd = find_nextcmd(end);
1755 }
1756 
1757 /*
1758  * ":finally"
1759  */
1760     void
1761 ex_finally(exarg_T *eap)
1762 {
1763     int		idx;
1764     int		skip = FALSE;
1765     int		pending = CSTP_NONE;
1766     cstack_T	*cstack = eap->cstack;
1767 
1768     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1769 	eap->errmsg = _(e_finally);
1770     else
1771     {
1772 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1773 	{
1774 	    eap->errmsg = get_end_emsg(cstack);
1775 	    for (idx = cstack->cs_idx - 1; idx > 0; --idx)
1776 		if (cstack->cs_flags[idx] & CSF_TRY)
1777 		    break;
1778 	    // Make this error pending, so that the commands in the following
1779 	    // finally clause can be executed.  This overrules also a pending
1780 	    // ":continue", ":break", ":return", or ":finish".
1781 	    pending = CSTP_ERROR;
1782 	}
1783 	else
1784 	    idx = cstack->cs_idx;
1785 
1786 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1787 	{
1788 	    // Give up for a multiple ":finally" and ignore it.
1789 	    eap->errmsg = _(e_finally_dup);
1790 	    return;
1791 	}
1792 	rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1793 						       &cstack->cs_looplevel);
1794 
1795 	/*
1796 	 * Don't do something when the corresponding try block never got active
1797 	 * (because of an inactive surrounding conditional or after an error or
1798 	 * interrupt or throw) or for a ":finally" without ":try" or a multiple
1799 	 * ":finally".  After every other error (did_emsg or the conditional
1800 	 * errors detected above) or after an interrupt (got_int) or an
1801 	 * exception (did_throw), the finally clause must be executed.
1802 	 */
1803 	skip = !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1804 
1805 	if (!skip)
1806 	{
1807 	    // When debugging or a breakpoint was encountered, display the
1808 	    // debug prompt (if not already done).  The user then knows that the
1809 	    // finally clause is executed.
1810 	    if (dbg_check_skipped(eap))
1811 	    {
1812 		// Handle a ">quit" debug command as if an interrupt had
1813 		// occurred before the ":finally".  That is, discard the
1814 		// original exception and replace it by an interrupt
1815 		// exception.
1816 		(void)do_intthrow(cstack);
1817 	    }
1818 
1819 	    /*
1820 	     * If there is a preceding catch clause and it caught the exception,
1821 	     * finish the exception now.  This happens also after errors except
1822 	     * when this is a multiple ":finally" or one not within a ":try".
1823 	     * After an error or interrupt, this also discards a pending
1824 	     * ":continue", ":break", ":finish", or ":return" from the preceding
1825 	     * try block or catch clause.
1826 	     */
1827 	    cleanup_conditionals(cstack, CSF_TRY, FALSE);
1828 
1829 	    /*
1830 	     * Make did_emsg, got_int, did_throw pending.  If set, they overrule
1831 	     * a pending ":continue", ":break", ":return", or ":finish".  Then
1832 	     * we have particularly to discard a pending return value (as done
1833 	     * by the call to cleanup_conditionals() above when did_emsg or
1834 	     * got_int is set).  The pending values are restored by the
1835 	     * ":endtry", except if there is a new error, interrupt, exception,
1836 	     * ":continue", ":break", ":return", or ":finish" in the following
1837 	     * finally clause.  A missing ":endwhile", ":endfor" or ":endif"
1838 	     * detected here is treated as if did_emsg and did_throw had
1839 	     * already been set, respectively in case that the error is not
1840 	     * converted to an exception, did_throw had already been unset.
1841 	     * We must not set did_emsg here since that would suppress the
1842 	     * error message.
1843 	     */
1844 	    if (pending == CSTP_ERROR || did_emsg || got_int || did_throw)
1845 	    {
1846 		if (cstack->cs_pending[cstack->cs_idx] == CSTP_RETURN)
1847 		{
1848 		    report_discard_pending(CSTP_RETURN,
1849 					   cstack->cs_rettv[cstack->cs_idx]);
1850 		    discard_pending_return(cstack->cs_rettv[cstack->cs_idx]);
1851 		}
1852 		if (pending == CSTP_ERROR && !did_emsg)
1853 		    pending |= (THROW_ON_ERROR) ? CSTP_THROW : 0;
1854 		else
1855 		    pending |= did_throw ? CSTP_THROW : 0;
1856 		pending |= did_emsg  ? CSTP_ERROR     : 0;
1857 		pending |= got_int   ? CSTP_INTERRUPT : 0;
1858 		cstack->cs_pending[cstack->cs_idx] = pending;
1859 
1860 		// It's mandatory that the current exception is stored in the
1861 		// cstack so that it can be rethrown at the ":endtry" or be
1862 		// discarded if the finally clause is left by a ":continue",
1863 		// ":break", ":return", ":finish", error, interrupt, or another
1864 		// exception.  When emsg() is called for a missing ":endif" or
1865 		// a missing ":endwhile"/":endfor" detected here, the
1866 		// exception will be discarded.
1867 		if (did_throw && cstack->cs_exception[cstack->cs_idx]
1868 							 != current_exception)
1869 		    internal_error("ex_finally()");
1870 	    }
1871 
1872 	    /*
1873 	     * Set CSL_HAD_FINA, so do_cmdline() will reset did_emsg,
1874 	     * got_int, and did_throw and make the finally clause active.
1875 	     * This will happen after emsg() has been called for a missing
1876 	     * ":endif" or a missing ":endwhile"/":endfor" detected here, so
1877 	     * that the following finally clause will be executed even then.
1878 	     */
1879 	    cstack->cs_lflags |= CSL_HAD_FINA;
1880 	}
1881     }
1882 }
1883 
1884 /*
1885  * ":endtry"
1886  */
1887     void
1888 ex_endtry(exarg_T *eap)
1889 {
1890     int		idx;
1891     int		skip;
1892     int		rethrow = FALSE;
1893     int		pending = CSTP_NONE;
1894     void	*rettv = NULL;
1895     cstack_T	*cstack = eap->cstack;
1896 
1897     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1898 	eap->errmsg = _(e_no_endtry);
1899     else
1900     {
1901 	/*
1902 	 * Don't do something after an error, interrupt or throw in the try
1903 	 * block, catch clause, or finally clause preceding this ":endtry" or
1904 	 * when an error or interrupt occurred after a ":continue", ":break",
1905 	 * ":return", or ":finish" in a try block or catch clause preceding this
1906 	 * ":endtry" or when the try block never got active (because of an
1907 	 * inactive surrounding conditional or after an error or interrupt or
1908 	 * throw) or when there is a surrounding conditional and it has been
1909 	 * made inactive by a ":continue", ":break", ":return", or ":finish" in
1910 	 * the finally clause.  The latter case need not be tested since then
1911 	 * anything pending has already been discarded. */
1912 	skip = did_emsg || got_int || did_throw ||
1913 	    !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1914 
1915 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1916 	{
1917 	    eap->errmsg = get_end_emsg(cstack);
1918 	    // Find the matching ":try" and report what's missing.
1919 	    idx = cstack->cs_idx;
1920 	    do
1921 		--idx;
1922 	    while (idx > 0 && !(cstack->cs_flags[idx] & CSF_TRY));
1923 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1924 						       &cstack->cs_looplevel);
1925 	    skip = TRUE;
1926 
1927 	    /*
1928 	     * If an exception is being thrown, discard it to prevent it from
1929 	     * being rethrown at the end of this function.  It would be
1930 	     * discarded by the error message, anyway.  Resets did_throw.
1931 	     * This does not affect the script termination due to the error
1932 	     * since "trylevel" is decremented after emsg() has been called.
1933 	     */
1934 	    if (did_throw)
1935 		discard_current_exception();
1936 	}
1937 	else
1938 	{
1939 	    idx = cstack->cs_idx;
1940 
1941 	    /*
1942 	     * If we stopped with the exception currently being thrown at this
1943 	     * try conditional since we didn't know that it doesn't have
1944 	     * a finally clause, we need to rethrow it after closing the try
1945 	     * conditional.
1946 	     */
1947 	    if (did_throw && (cstack->cs_flags[idx] & CSF_TRUE)
1948 		    && !(cstack->cs_flags[idx] & CSF_FINALLY))
1949 		rethrow = TRUE;
1950 	}
1951 
1952 	// If there was no finally clause, show the user when debugging or
1953 	// a breakpoint was encountered that the end of the try conditional has
1954 	// been reached: display the debug prompt (if not already done).  Do
1955 	// this on normal control flow or when an exception was thrown, but not
1956 	// on an interrupt or error not converted to an exception or when
1957 	// a ":break", ":continue", ":return", or ":finish" is pending.  These
1958 	// actions are carried out immediately.
1959 	if ((rethrow || (!skip
1960 			&& !(cstack->cs_flags[idx] & CSF_FINALLY)
1961 			&& !cstack->cs_pending[idx]))
1962 		&& dbg_check_skipped(eap))
1963 	{
1964 	    // Handle a ">quit" debug command as if an interrupt had occurred
1965 	    // before the ":endtry".  That is, throw an interrupt exception and
1966 	    // set "skip" and "rethrow".
1967 	    if (got_int)
1968 	    {
1969 		skip = TRUE;
1970 		(void)do_intthrow(cstack);
1971 		// The do_intthrow() call may have reset did_throw or
1972 		// cstack->cs_pending[idx].
1973 		rethrow = FALSE;
1974 		if (did_throw && !(cstack->cs_flags[idx] & CSF_FINALLY))
1975 		    rethrow = TRUE;
1976 	    }
1977 	}
1978 
1979 	/*
1980 	 * If a ":return" is pending, we need to resume it after closing the
1981 	 * try conditional; remember the return value.  If there was a finally
1982 	 * clause making an exception pending, we need to rethrow it.  Make it
1983 	 * the exception currently being thrown.
1984 	 */
1985 	if (!skip)
1986 	{
1987 	    pending = cstack->cs_pending[idx];
1988 	    cstack->cs_pending[idx] = CSTP_NONE;
1989 	    if (pending == CSTP_RETURN)
1990 		rettv = cstack->cs_rettv[idx];
1991 	    else if (pending & CSTP_THROW)
1992 		current_exception = cstack->cs_exception[idx];
1993 	}
1994 
1995 	/*
1996 	 * Discard anything pending on an error, interrupt, or throw in the
1997 	 * finally clause.  If there was no ":finally", discard a pending
1998 	 * ":continue", ":break", ":return", or ":finish" if an error or
1999 	 * interrupt occurred afterwards, but before the ":endtry" was reached.
2000 	 * If an exception was caught by the last of the catch clauses and there
2001 	 * was no finally clause, finish the exception now.  This happens also
2002 	 * after errors except when this ":endtry" is not within a ":try".
2003 	 * Restore "emsg_silent" if it has been reset by this try conditional.
2004 	 */
2005 	(void)cleanup_conditionals(cstack, CSF_TRY | CSF_SILENT, TRUE);
2006 
2007 	leave_block(cstack);
2008 	--cstack->cs_trylevel;
2009 
2010 	if (!skip)
2011 	{
2012 	    report_resume_pending(pending,
2013 		    (pending == CSTP_RETURN) ? rettv :
2014 		    (pending & CSTP_THROW) ? (void *)current_exception : NULL);
2015 	    switch (pending)
2016 	    {
2017 		case CSTP_NONE:
2018 		    break;
2019 
2020 		// Reactivate a pending ":continue", ":break", ":return",
2021 		// ":finish" from the try block or a catch clause of this try
2022 		// conditional.  This is skipped, if there was an error in an
2023 		// (unskipped) conditional command or an interrupt afterwards
2024 		// or if the finally clause is present and executed a new error,
2025 		// interrupt, throw, ":continue", ":break", ":return", or
2026 		// ":finish".
2027 		case CSTP_CONTINUE:
2028 		    ex_continue(eap);
2029 		    break;
2030 		case CSTP_BREAK:
2031 		    ex_break(eap);
2032 		    break;
2033 		case CSTP_RETURN:
2034 		    do_return(eap, FALSE, FALSE, rettv);
2035 		    break;
2036 		case CSTP_FINISH:
2037 		    do_finish(eap, FALSE);
2038 		    break;
2039 
2040 		// When the finally clause was entered due to an error,
2041 		// interrupt or throw (as opposed to a ":continue", ":break",
2042 		// ":return", or ":finish"), restore the pending values of
2043 		// did_emsg, got_int, and did_throw.  This is skipped, if there
2044 		// was a new error, interrupt, throw, ":continue", ":break",
2045 		// ":return", or ":finish".  in the finally clause.
2046 		default:
2047 		    if (pending & CSTP_ERROR)
2048 			did_emsg = TRUE;
2049 		    if (pending & CSTP_INTERRUPT)
2050 			got_int = TRUE;
2051 		    if (pending & CSTP_THROW)
2052 			rethrow = TRUE;
2053 		    break;
2054 	    }
2055 	}
2056 
2057 	if (rethrow)
2058 	    // Rethrow the current exception (within this cstack).
2059 	    do_throw(cstack);
2060     }
2061 }
2062 
2063 /*
2064  * enter_cleanup() and leave_cleanup()
2065  *
2066  * Functions to be called before/after invoking a sequence of autocommands for
2067  * cleanup for a failed command.  (Failure means here that a call to emsg()
2068  * has been made, an interrupt occurred, or there is an uncaught exception
2069  * from a previous autocommand execution of the same command.)
2070  *
2071  * Call enter_cleanup() with a pointer to a cleanup_T and pass the same
2072  * pointer to leave_cleanup().  The cleanup_T structure stores the pending
2073  * error/interrupt/exception state.
2074  */
2075 
2076 /*
2077  * This function works a bit like ex_finally() except that there was not
2078  * actually an extra try block around the part that failed and an error or
2079  * interrupt has not (yet) been converted to an exception.  This function
2080  * saves the error/interrupt/ exception state and prepares for the call to
2081  * do_cmdline() that is going to be made for the cleanup autocommand
2082  * execution.
2083  */
2084     void
2085 enter_cleanup(cleanup_T *csp)
2086 {
2087     int		pending = CSTP_NONE;
2088 
2089     /*
2090      * Postpone did_emsg, got_int, did_throw.  The pending values will be
2091      * restored by leave_cleanup() except if there was an aborting error,
2092      * interrupt, or uncaught exception after this function ends.
2093      */
2094     if (did_emsg || got_int || did_throw || need_rethrow)
2095     {
2096 	csp->pending = (did_emsg     ? CSTP_ERROR     : 0)
2097 		     | (got_int      ? CSTP_INTERRUPT : 0)
2098 		     | (did_throw    ? CSTP_THROW     : 0)
2099 		     | (need_rethrow ? CSTP_THROW     : 0);
2100 
2101 	// If we are currently throwing an exception (did_throw), save it as
2102 	// well.  On an error not yet converted to an exception, update
2103 	// "force_abort" and reset "cause_abort" (as do_errthrow() would do).
2104 	// This is needed for the do_cmdline() call that is going to be made
2105 	// for autocommand execution.  We need not save *msg_list because
2106 	// there is an extra instance for every call of do_cmdline(), anyway.
2107 	if (did_throw || need_rethrow)
2108 	{
2109 	    csp->exception = current_exception;
2110 	    current_exception = NULL;
2111 	}
2112 	else
2113 	{
2114 	    csp->exception = NULL;
2115 	    if (did_emsg)
2116 	    {
2117 		force_abort |= cause_abort;
2118 		cause_abort = FALSE;
2119 	    }
2120 	}
2121 	did_emsg = got_int = did_throw = need_rethrow = FALSE;
2122 
2123 	// Report if required by the 'verbose' option or when debugging.
2124 	report_make_pending(pending, csp->exception);
2125     }
2126     else
2127     {
2128 	csp->pending = CSTP_NONE;
2129 	csp->exception = NULL;
2130     }
2131 }
2132 
2133 /*
2134  * See comment above enter_cleanup() for how this function is used.
2135  *
2136  * This function is a bit like ex_endtry() except that there was not actually
2137  * an extra try block around the part that failed and an error or interrupt
2138  * had not (yet) been converted to an exception when the cleanup autocommand
2139  * sequence was invoked.
2140  *
2141  * This function has to be called with the address of the cleanup_T structure
2142  * filled by enter_cleanup() as an argument; it restores the error/interrupt/
2143  * exception state saved by that function - except there was an aborting
2144  * error, an interrupt or an uncaught exception during execution of the
2145  * cleanup autocommands.  In the latter case, the saved error/interrupt/
2146  * exception state is discarded.
2147  */
2148     void
2149 leave_cleanup(cleanup_T *csp)
2150 {
2151     int		pending = csp->pending;
2152 
2153     if (pending == CSTP_NONE)	// nothing to do
2154 	return;
2155 
2156     // If there was an aborting error, an interrupt, or an uncaught exception
2157     // after the corresponding call to enter_cleanup(), discard what has been
2158     // made pending by it.  Report this to the user if required by the
2159     // 'verbose' option or when debugging.
2160     if (aborting() || need_rethrow)
2161     {
2162 	if (pending & CSTP_THROW)
2163 	    // Cancel the pending exception (includes report).
2164 	    discard_exception((except_T *)csp->exception, FALSE);
2165 	else
2166 	    report_discard_pending(pending, NULL);
2167 
2168 	// If an error was about to be converted to an exception when
2169 	// enter_cleanup() was called, free the message list.
2170 	if (msg_list != NULL)
2171 	    free_global_msglist();
2172     }
2173 
2174     /*
2175      * If there was no new error, interrupt, or throw between the calls
2176      * to enter_cleanup() and leave_cleanup(), restore the pending
2177      * error/interrupt/exception state.
2178      */
2179     else
2180     {
2181 	/*
2182 	 * If there was an exception being thrown when enter_cleanup() was
2183 	 * called, we need to rethrow it.  Make it the exception currently
2184 	 * being thrown.
2185 	 */
2186 	if (pending & CSTP_THROW)
2187 	    current_exception = csp->exception;
2188 
2189 	/*
2190 	 * If an error was about to be converted to an exception when
2191 	 * enter_cleanup() was called, let "cause_abort" take the part of
2192 	 * "force_abort" (as done by cause_errthrow()).
2193 	 */
2194 	else if (pending & CSTP_ERROR)
2195 	{
2196 	    cause_abort = force_abort;
2197 	    force_abort = FALSE;
2198 	}
2199 
2200 	/*
2201 	 * Restore the pending values of did_emsg, got_int, and did_throw.
2202 	 */
2203 	if (pending & CSTP_ERROR)
2204 	    did_emsg = TRUE;
2205 	if (pending & CSTP_INTERRUPT)
2206 	    got_int = TRUE;
2207 	if (pending & CSTP_THROW)
2208 	    need_rethrow = TRUE;    // did_throw will be set by do_one_cmd()
2209 
2210 	// Report if required by the 'verbose' option or when debugging.
2211 	report_resume_pending(pending,
2212 		   (pending & CSTP_THROW) ? (void *)current_exception : NULL);
2213     }
2214 }
2215 
2216 
2217 /*
2218  * Make conditionals inactive and discard what's pending in finally clauses
2219  * until the conditional type searched for or a try conditional not in its
2220  * finally clause is reached.  If this is in an active catch clause, finish
2221  * the caught exception.
2222  * Return the cstack index where the search stopped.
2223  * Values used for "searched_cond" are (CSF_WHILE | CSF_FOR) or CSF_TRY or 0,
2224  * the latter meaning the innermost try conditional not in its finally clause.
2225  * "inclusive" tells whether the conditional searched for should be made
2226  * inactive itself (a try conditional not in its finally clause possibly find
2227  * before is always made inactive).  If "inclusive" is TRUE and
2228  * "searched_cond" is CSF_TRY|CSF_SILENT, the saved former value of
2229  * "emsg_silent", if reset when the try conditional finally reached was
2230  * entered, is restored (used by ex_endtry()).  This is normally done only
2231  * when such a try conditional is left.
2232  */
2233     int
2234 cleanup_conditionals(
2235     cstack_T   *cstack,
2236     int		searched_cond,
2237     int		inclusive)
2238 {
2239     int		idx;
2240     int		stop = FALSE;
2241 
2242     for (idx = cstack->cs_idx; idx >= 0; --idx)
2243     {
2244 	if (cstack->cs_flags[idx] & CSF_TRY)
2245 	{
2246 	    /*
2247 	     * Discard anything pending in a finally clause and continue the
2248 	     * search.  There may also be a pending ":continue", ":break",
2249 	     * ":return", or ":finish" before the finally clause.  We must not
2250 	     * discard it, unless an error or interrupt occurred afterwards.
2251 	     */
2252 	    if (did_emsg || got_int || (cstack->cs_flags[idx] & CSF_FINALLY))
2253 	    {
2254 		switch (cstack->cs_pending[idx])
2255 		{
2256 		    case CSTP_NONE:
2257 			break;
2258 
2259 		    case CSTP_CONTINUE:
2260 		    case CSTP_BREAK:
2261 		    case CSTP_FINISH:
2262 			report_discard_pending(cstack->cs_pending[idx], NULL);
2263 			cstack->cs_pending[idx] = CSTP_NONE;
2264 			break;
2265 
2266 		    case CSTP_RETURN:
2267 			report_discard_pending(CSTP_RETURN,
2268 						      cstack->cs_rettv[idx]);
2269 			discard_pending_return(cstack->cs_rettv[idx]);
2270 			cstack->cs_pending[idx] = CSTP_NONE;
2271 			break;
2272 
2273 		    default:
2274 			if (cstack->cs_flags[idx] & CSF_FINALLY)
2275 			{
2276 			    if (cstack->cs_pending[idx] & CSTP_THROW)
2277 			    {
2278 				// Cancel the pending exception.  This is in the
2279 				// finally clause, so that the stack of the
2280 				// caught exceptions is not involved.
2281 				discard_exception((except_T *)
2282 					cstack->cs_exception[idx],
2283 					FALSE);
2284 			    }
2285 			    else
2286 				report_discard_pending(cstack->cs_pending[idx],
2287 					NULL);
2288 			    cstack->cs_pending[idx] = CSTP_NONE;
2289 			}
2290 			break;
2291 		}
2292 	    }
2293 
2294 	    /*
2295 	     * Stop at a try conditional not in its finally clause.  If this try
2296 	     * conditional is in an active catch clause, finish the caught
2297 	     * exception.
2298 	     */
2299 	    if (!(cstack->cs_flags[idx] & CSF_FINALLY))
2300 	    {
2301 		if ((cstack->cs_flags[idx] & CSF_ACTIVE)
2302 			&& (cstack->cs_flags[idx] & CSF_CAUGHT))
2303 		    finish_exception((except_T *)cstack->cs_exception[idx]);
2304 		// Stop at this try conditional - except the try block never
2305 		// got active (because of an inactive surrounding conditional
2306 		// or when the ":try" appeared after an error or interrupt or
2307 		// throw).
2308 		if (cstack->cs_flags[idx] & CSF_TRUE)
2309 		{
2310 		    if (searched_cond == 0 && !inclusive)
2311 			break;
2312 		    stop = TRUE;
2313 		}
2314 	    }
2315 	}
2316 
2317 	// Stop on the searched conditional type (even when the surrounding
2318 	// conditional is not active or something has been made pending).
2319 	// If "inclusive" is TRUE and "searched_cond" is CSF_TRY|CSF_SILENT,
2320 	// check first whether "emsg_silent" needs to be restored.
2321 	if (cstack->cs_flags[idx] & searched_cond)
2322 	{
2323 	    if (!inclusive)
2324 		break;
2325 	    stop = TRUE;
2326 	}
2327 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
2328 	if (stop && searched_cond != (CSF_TRY | CSF_SILENT))
2329 	    break;
2330 
2331 	/*
2332 	 * When leaving a try conditional that reset "emsg_silent" on its
2333 	 * entry after saving the original value, restore that value here and
2334 	 * free the memory used to store it.
2335 	 */
2336 	if ((cstack->cs_flags[idx] & CSF_TRY)
2337 		&& (cstack->cs_flags[idx] & CSF_SILENT))
2338 	{
2339 	    eslist_T	*elem;
2340 
2341 	    elem = cstack->cs_emsg_silent_list;
2342 	    cstack->cs_emsg_silent_list = elem->next;
2343 	    emsg_silent = elem->saved_emsg_silent;
2344 	    vim_free(elem);
2345 	    cstack->cs_flags[idx] &= ~CSF_SILENT;
2346 	}
2347 	if (stop)
2348 	    break;
2349     }
2350     return idx;
2351 }
2352 
2353 /*
2354  * Return an appropriate error message for a missing endwhile/endfor/endif.
2355  */
2356    static char *
2357 get_end_emsg(cstack_T *cstack)
2358 {
2359     if (cstack->cs_flags[cstack->cs_idx] & CSF_WHILE)
2360 	return _(e_endwhile);
2361     if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2362 	return _(e_endfor);
2363     return _(e_endif);
2364 }
2365 
2366 
2367 /*
2368  * Rewind conditionals until index "idx" is reached.  "cond_type" and
2369  * "cond_level" specify a conditional type and the address of a level variable
2370  * which is to be decremented with each skipped conditional of the specified
2371  * type.
2372  * Also free "for info" structures where needed.
2373  */
2374     void
2375 rewind_conditionals(
2376     cstack_T   *cstack,
2377     int		idx,
2378     int		cond_type,
2379     int		*cond_level)
2380 {
2381     while (cstack->cs_idx > idx)
2382     {
2383 	if (cstack->cs_flags[cstack->cs_idx] & cond_type)
2384 	    --*cond_level;
2385 	if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2386 	    free_for_info(cstack->cs_forinfo[cstack->cs_idx]);
2387 	leave_block(cstack);
2388     }
2389 }
2390 
2391 /*
2392  * ":endfunction" when not after a ":function"
2393  */
2394     void
2395 ex_endfunction(exarg_T *eap)
2396 {
2397     if (eap->cmdidx == CMD_enddef)
2398 	emsg(_("E193: :enddef not inside a function"));
2399     else
2400 	emsg(_("E193: :endfunction not inside a function"));
2401 }
2402 
2403 /*
2404  * Return TRUE if the string "p" looks like a ":while" or ":for" command.
2405  */
2406     int
2407 has_loop_cmd(char_u *p)
2408 {
2409     int		len;
2410 
2411     // skip modifiers, white space and ':'
2412     for (;;)
2413     {
2414 	while (*p == ' ' || *p == '\t' || *p == ':')
2415 	    ++p;
2416 	len = modifier_len(p);
2417 	if (len == 0)
2418 	    break;
2419 	p += len;
2420     }
2421     if ((p[0] == 'w' && p[1] == 'h')
2422 	    || (p[0] == 'f' && p[1] == 'o' && p[2] == 'r'))
2423 	return TRUE;
2424     return FALSE;
2425 }
2426 
2427 #endif // FEAT_EVAL
2428