xref: /vim-8.2.3635/src/ex_eval.c (revision 044b68f4)
1 /* vi:set ts=8 sts=4 sw=4:
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 void	free_msglist __ARGS((struct msglist *l));
19 static int	throw_exception __ARGS((void *, int, char_u *));
20 static char_u	*get_end_emsg __ARGS((struct condstack *cstack));
21 
22 /*
23  * Exception handling terms:
24  *
25  *	:try		":try" command		\
26  *	    ...		try block		|
27  *	:catch RE	":catch" command	|
28  *	    ...		catch clause		|- try conditional
29  *	:finally	":finally" command	|
30  *	    ...		finally clause		|
31  *	:endtry		":endtry" command	/
32  *
33  * The try conditional may have any number of catch clauses and at most one
34  * finally clause.  A ":throw" command can be inside the try block, a catch
35  * clause, the finally clause, or in a function called or script sourced from
36  * there or even outside the try conditional.  Try conditionals may be nested.
37  */
38 
39 /*
40  * Configuration whether an exception is thrown on error or interrupt.  When
41  * the preprocessor macros below evaluate to FALSE, an error (did_emsg) or
42  * interrupt (got_int) under an active try conditional terminates the script
43  * after the non-active finally clauses of all active try conditionals have been
44  * executed.  Otherwise, errors and/or interrupts are converted into catchable
45  * exceptions (did_throw additionally set), which terminate the script only if
46  * not caught.  For user exceptions, only did_throw is set.  (Note: got_int can
47  * be set asyncronously afterwards by a SIGINT, so did_throw && got_int is not
48  * a reliant test that the exception currently being thrown is an interrupt
49  * exception.  Similarly, did_emsg can be set afterwards on an error in an
50  * (unskipped) conditional command inside an inactive conditional, so did_throw
51  * && did_emsg is not a reliant test that the exception currently being thrown
52  * is an error exception.)  -  The macros can be defined as expressions checking
53  * for a variable that is allowed to be changed during execution of a script.
54  */
55 #if 0
56 /* Expressions used for testing during the development phase. */
57 # define THROW_ON_ERROR		(!eval_to_number("$VIMNOERRTHROW"))
58 # define THROW_ON_INTERRUPT	(!eval_to_number("$VIMNOINTTHROW"))
59 # define THROW_TEST
60 #else
61 /* Values used for the Vim release. */
62 # define THROW_ON_ERROR		TRUE
63 # define THROW_ON_INTERRUPT	TRUE
64 #endif
65 
66 static void	catch_exception __ARGS((except_T *excp));
67 static void	finish_exception __ARGS((except_T *excp));
68 static void	discard_exception __ARGS((except_T *excp, int was_finished));
69 static void	report_pending __ARGS((int action, int pending, void *value));
70 
71 /*
72  * When several errors appear in a row, setting "force_abort" is delayed until
73  * the failing command returned.  "cause_abort" is set to TRUE meanwhile, in
74  * order to indicate that situation.  This is useful when "force_abort" was set
75  * during execution of a function call from an expression: the aborting of the
76  * expression evaluation is done without producing any error messages, but all
77  * error messages on parsing errors during the expression evaluation are given
78  * (even if a try conditional is active).
79  */
80 static int cause_abort = FALSE;
81 
82 /*
83  * Return TRUE when immdediately aborting on error, or when an interrupt
84  * occurred or an exception was thrown but not caught.  Use for ":{range}call"
85  * to check whether an aborted function that does not handle a range itself
86  * should be called again for the next line in the range.  Also used for
87  * cancelling expression evaluation after a function call caused an immediate
88  * abort.  Note that the first emsg() call temporarily resets "force_abort"
89  * until the throw point for error messages has been reached.  That is, during
90  * cancellation of an expression evaluation after an aborting function call or
91  * due to a parsing error, aborting() always returns the same value.
92  */
93     int
94 aborting()
95 {
96     return (did_emsg && force_abort) || got_int || did_throw;
97 }
98 
99 /*
100  * The value of "force_abort" is temporarily reset by the first emsg() call
101  * during an expression evaluation, and "cause_abort" is used instead.  It might
102  * be necessary to restore "force_abort" even before the throw point for the
103  * error message has been reached.  update_force_abort() should be called then.
104  */
105     void
106 update_force_abort()
107 {
108     if (cause_abort)
109 	force_abort = TRUE;
110 }
111 
112 /*
113  * Return TRUE if a command with a subcommand resulting in "retcode" should
114  * abort the script processing.  Can be used to suppress an autocommand after
115  * execution of a failing subcommand as long as the error message has not been
116  * displayed and actually caused the abortion.
117  */
118     int
119 should_abort(retcode)
120     int		retcode;
121 {
122     return ((retcode == FAIL && trylevel != 0 && !emsg_silent) || aborting());
123 }
124 
125 /*
126  * Return TRUE if a function with the "abort" flag should not be considered
127  * ended on an error.  This means that parsing commands is continued in order
128  * to find finally clauses to be executed, and that some errors in skipped
129  * commands are still reported.
130  */
131     int
132 aborted_in_try()
133 {
134     /* This function is only called after an error.  In this case, "force_abort"
135      * determines whether searching for finally clauses is necessary. */
136     return force_abort;
137 }
138 
139 /*
140  * cause_errthrow(): Cause a throw of an error exception if appropriate.
141  * Return TRUE if the error message should not be displayed by emsg().
142  * Sets "ignore", if the emsg() call should be ignored completely.
143  *
144  * When several messages appear in the same command, the first is usually the
145  * most specific one and used as the exception value.  The "severe" flag can be
146  * set to TRUE, if a later but severer message should be used instead.
147  */
148     int
149 cause_errthrow(mesg, severe, ignore)
150     char_u	*mesg;
151     int		severe;
152     int		*ignore;
153 {
154     struct msglist *elem;
155     struct msglist **plist;
156 
157     /*
158      * Do nothing when displaying the interrupt message or reporting an
159      * uncaught exception (which has already been discarded then) at the top
160      * level.  Also when no exception can be thrown.  The message will be
161      * displayed by emsg().
162      */
163     if (suppress_errthrow)
164 	return FALSE;
165 
166     /*
167      * If emsg() has not been called previously, temporarily reset
168      * "force_abort" until the throw point for error messages has been
169      * reached.  This ensures that aborting() returns the same value for all
170      * errors that appear in the same command.  This means particularly that
171      * for parsing errors during expression evaluation emsg() will be called
172      * multiply, even when the expression is evaluated from a finally clause
173      * that was activated due to an aborting error, interrupt, or exception.
174      */
175     if (!did_emsg)
176     {
177 	cause_abort = force_abort;
178 	force_abort = FALSE;
179     }
180 
181     /*
182      * If no try conditional is active and no exception is being thrown and
183      * there has not been an error in a try conditional or a throw so far, do
184      * nothing (for compatibility of non-EH scripts).  The message will then
185      * be displayed by emsg().  When ":silent!" was used and we are not
186      * currently throwing an exception, do nothing.  The message text will
187      * then be stored to v:errmsg by emsg() without displaying it.
188      */
189     if (((trylevel == 0 && !cause_abort) || emsg_silent) && !did_throw)
190 	return FALSE;
191 
192     /*
193      * Ignore an interrupt message when inside a try conditional or when an
194      * exception is being thrown or when an error in a try conditional or
195      * throw has been detected previously.  This is important in order that an
196      * interrupt exception is catchable by the innermost try conditional and
197      * not replaced by an interrupt message error exception.
198      */
199     if (mesg == (char_u *)_(e_interr))
200     {
201 	*ignore = TRUE;
202 	return TRUE;
203     }
204 
205     /*
206      * Ensure that all commands in nested function calls and sourced files
207      * are aborted immediately.
208      */
209     cause_abort = TRUE;
210 
211     /*
212      * When an exception is being thrown, some commands (like conditionals) are
213      * not skipped.  Errors in those commands may affect what of the subsequent
214      * commands are regarded part of catch and finally clauses.  Catching the
215      * exception would then cause execution of commands not intended by the
216      * user, who wouldn't even get aware of the problem.  Therefor, discard the
217      * exception currently being thrown to prevent it from being caught.  Just
218      * execute finally clauses and terminate.
219      */
220     if (did_throw)
221     {
222 	/* When discarding an interrupt exception, reset got_int to prevent the
223 	 * same interrupt being converted to an exception again and discarding
224 	 * the error exception we are about to throw here. */
225 	if (current_exception->type == ET_INTERRUPT)
226 	    got_int = FALSE;
227 	discard_current_exception();
228     }
229 
230 #ifdef THROW_TEST
231     if (!THROW_ON_ERROR)
232     {
233 	/*
234 	 * Print error message immediately without searching for a matching
235 	 * catch clause; just finally clauses are executed before the script
236 	 * is terminated.
237 	 */
238 	return FALSE;
239     }
240     else
241 #endif
242     {
243 	/*
244 	 * Prepare the throw of an error exception, so that everything will
245 	 * be aborted (except for executing finally clauses), until the error
246 	 * exception is caught; if still uncaught at the top level, the error
247 	 * message will be displayed and the script processing terminated
248 	 * then.  -  This function has no access to the conditional stack.
249 	 * Thus, the actual throw is made after the failing command has
250 	 * returned.  -  Throw only the first of several errors in a row, except
251 	 * a severe error is following.
252 	 */
253 	if (msg_list != NULL)
254 	{
255 	    plist = msg_list;
256 	    while (*plist != NULL)
257 		plist = &(*plist)->next;
258 
259 	    elem = (struct msglist *)alloc((unsigned)sizeof(struct msglist));
260 	    if (elem == NULL)
261 	    {
262 		suppress_errthrow = TRUE;
263 		EMSG(_(e_outofmem));
264 	    }
265 	    else
266 	    {
267 		elem->msg = vim_strsave(mesg);
268 		if (elem->msg == NULL)
269 		{
270 		    vim_free(elem);
271 		    suppress_errthrow = TRUE;
272 		    EMSG(_(e_outofmem));
273 		}
274 		else
275 		{
276 		    elem->next = NULL;
277 		    elem->throw_msg = NULL;
278 		    *plist = elem;
279 		    if (plist == msg_list || severe)
280 		    {
281 			char_u	    *tmsg;
282 
283 			/* Skip the extra "Vim " prefix for message "E458". */
284 			tmsg = elem->msg;
285 			if (STRNCMP(tmsg, "Vim E", 5) == 0
286 				&& VIM_ISDIGIT(tmsg[5])
287 				&& VIM_ISDIGIT(tmsg[6])
288 				&& VIM_ISDIGIT(tmsg[7])
289 				&& tmsg[8] == ':'
290 				&& tmsg[9] == ' ')
291 			    (*msg_list)->throw_msg = &tmsg[4];
292 			else
293 			    (*msg_list)->throw_msg = tmsg;
294 		    }
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(l)
307     struct msglist  *l;
308 {
309     struct msglist  *messages, *next;
310 
311     messages = l;
312     while (messages != NULL)
313     {
314 	next = messages->next;
315 	vim_free(messages->msg);
316 	vim_free(messages);
317 	messages = next;
318     }
319 }
320 
321 /*
322  * Throw the message specified in the call to cause_errthrow() above as an
323  * error exception.  If cstack is NULL, postpone the throw until do_cmdline()
324  * has returned (see do_one_cmd()).
325  */
326     void
327 do_errthrow(cstack, cmdname)
328     struct condstack	*cstack;
329     char_u		*cmdname;
330 {
331     /*
332      * Ensure that all commands in nested function calls and sourced files
333      * are aborted immediately.
334      */
335     if (cause_abort)
336     {
337 	cause_abort = FALSE;
338 	force_abort = TRUE;
339     }
340 
341     /* If no exception is to be thrown or the conversion should be done after
342      * returning to a previous invocation of do_one_cmd(), do nothing. */
343     if (msg_list == NULL || *msg_list == NULL)
344 	return;
345 
346     if (throw_exception(*msg_list, ET_ERROR, cmdname) == FAIL)
347 	free_msglist(*msg_list);
348     else
349     {
350 	if (cstack != NULL)
351 	    do_throw(cstack);
352 	else
353 	    need_rethrow = TRUE;
354     }
355     *msg_list = NULL;
356 }
357 
358 /*
359  * do_intthrow(): Replace the current exception by an interrupt or interrupt
360  * exception if appropriate.  Return TRUE if the current exception is discarded,
361  * FALSE otherwise.
362  */
363     int
364 do_intthrow(cstack)
365     struct condstack	*cstack;
366 {
367     /*
368      * If no interrupt occurred or no try conditional is active and no exception
369      * is being thrown, do nothing (for compatibility of non-EH scripts).
370      */
371     if (!got_int || (trylevel == 0 && !did_throw))
372 	return FALSE;
373 
374 #ifdef THROW_TEST	/* avoid warning for condition always true */
375     if (!THROW_ON_INTERRUPT)
376     {
377 	/*
378 	 * The interrupt aborts everything except for executing finally clauses.
379 	 * Discard any user or error or interrupt exception currently being
380 	 * thrown.
381 	 */
382 	if (did_throw)
383 	    discard_current_exception();
384     }
385     else
386 #endif
387     {
388 	/*
389 	 * Throw an interrupt exception, so that everything will be aborted
390 	 * (except for executing finally clauses), until the interrupt exception
391 	 * is caught; if still uncaught at the top level, the script processing
392 	 * will be terminated then.  -  If an interrupt exception is already
393 	 * being thrown, do nothing.
394 	 *
395 	 */
396 	if (did_throw)
397 	{
398 	    if (current_exception->type == ET_INTERRUPT)
399 		return FALSE;
400 
401 	    /* An interrupt exception replaces any user or error exception. */
402 	    discard_current_exception();
403 	}
404 	if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) != FAIL)
405 	    do_throw(cstack);
406     }
407 
408     return TRUE;
409 }
410 
411 
412 /*
413  * Throw a new exception.  Return FAIL when out of memory or it was tried to
414  * throw an illegal user exception.  "value" is the exception string for a user
415  * or interrupt exception, or points to a message list in case of an error
416  * exception.
417  */
418     static int
419 throw_exception(value, type, cmdname)
420     void	*value;
421     int		type;
422     char_u	*cmdname;
423 {
424     except_T	*excp;
425     char_u	*p, *mesg, *val;
426     int		cmdlen;
427 
428     /*
429      * Disallow faking Interrupt or error exceptions as user exceptions.  They
430      * would be treated differently from real interrupt or error exceptions when
431      * no active try block is found, see do_cmdline().
432      */
433     if (type == ET_USER)
434     {
435 	if (STRNCMP((char_u *)value, "Vim", 3) == 0 &&
436 		(((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':' ||
437 		 ((char_u *)value)[3] == '('))
438 	{
439 	    EMSG(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
440 	    goto fail;
441 	}
442     }
443 
444     excp = (except_T *)alloc((unsigned)sizeof(except_T));
445     if (excp == NULL)
446 	goto nomem;
447 
448     if (type == ET_ERROR)
449     {
450 	/* Store the original message and prefix the exception value with
451 	 * "Vim:" or, if a command name is given, "Vim(cmdname):". */
452 	excp->messages = (struct msglist *)value;
453 	mesg = excp->messages->throw_msg;
454 	if (cmdname != NULL && *cmdname != NUL)
455 	{
456 	    cmdlen = (int)STRLEN(cmdname);
457 	    excp->value = vim_strnsave((char_u *)"Vim(",
458 					   4 + cmdlen + 2 + (int)STRLEN(mesg));
459 	    if (excp->value == NULL)
460 		goto nomem;
461 	    STRCPY(&excp->value[4], cmdname);
462 	    STRCPY(&excp->value[4 + cmdlen], "):");
463 	    val = excp->value + 4 + cmdlen + 2;
464 	}
465 	else
466 	{
467 	    excp->value = vim_strnsave((char_u *)"Vim:", 4 + (int)STRLEN(mesg));
468 	    if (excp->value == NULL)
469 		goto nomem;
470 	    val = excp->value + 4;
471 	}
472 
473 	/* msg_add_fname may have been used to prefix the message with a file
474 	 * name in quotes.  In the exception value, put the file name in
475 	 * parentheses and move it to the end. */
476 	for (p = mesg; ; p++)
477 	{
478 	    if (*p == NUL
479 		    || (*p == 'E'
480 			&& VIM_ISDIGIT(p[1])
481 			&& (p[2] == ':'
482 			    || (VIM_ISDIGIT(p[2])
483 				&& (p[3] == ':'
484 				    || (VIM_ISDIGIT(p[3])
485 					&& p[4] == ':'))))))
486 	    {
487 		if (*p == NUL || p == mesg)
488 		    STRCAT(val, mesg);  /* 'E123' missing or at beginning */
489 		else
490 		{
491 		    /* '"filename" E123: message text' */
492 		    if (mesg[0] != '"' || p-2 < &mesg[1] ||
493 			    p[-2] != '"' || p[-1] != ' ')
494 			/* "E123:" is part of the file name. */
495 			continue;
496 
497 		    STRCAT(val, p);
498 		    p[-2] = NUL;
499 		    sprintf((char *)(val + STRLEN(p)), " (%s)", &mesg[1]);
500 		    p[-2] = '"';
501 		}
502 		break;
503 	    }
504 	}
505     }
506     else
507 	excp->value = value;
508 
509     excp->type = type;
510     excp->throw_name = vim_strsave(sourcing_name == NULL
511 					      ? (char_u *)"" : sourcing_name);
512     if (excp->throw_name == NULL)
513     {
514 	if (type == ET_ERROR)
515 	    vim_free(excp->value);
516 	goto nomem;
517     }
518     excp->throw_lnum = sourcing_lnum;
519 
520     if (p_verbose >= 13 || debug_break_level > 0)
521     {
522 	int	save_msg_silent = msg_silent;
523 
524 	if (debug_break_level > 0)
525 	    msg_silent = FALSE;		/* display messages */
526 	else
527 	    verbose_enter();
528 	++no_wait_return;
529 	if (debug_break_level > 0 || *p_vfile == NUL)
530 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
531 
532 	smsg((char_u *)_("Exception thrown: %s"), excp->value);
533 	msg_puts((char_u *)"\n");   /* don't overwrite this either */
534 
535 	if (debug_break_level > 0 || *p_vfile == NUL)
536 	    cmdline_row = msg_row;
537 	--no_wait_return;
538 	if (debug_break_level > 0)
539 	    msg_silent = save_msg_silent;
540 	else
541 	    verbose_leave();
542     }
543 
544     current_exception = excp;
545     return OK;
546 
547 nomem:
548     vim_free(excp);
549     suppress_errthrow = TRUE;
550     EMSG(_(e_outofmem));
551 fail:
552     current_exception = NULL;
553     return FAIL;
554 }
555 
556 /*
557  * Discard an exception.  "was_finished" is set when the exception has been
558  * caught and the catch clause has been ended normally.
559  */
560     static void
561 discard_exception(excp, was_finished)
562     except_T		*excp;
563     int			was_finished;
564 {
565     char_u		*saved_IObuff;
566 
567     if (excp == NULL)
568     {
569 	EMSG(_(e_internal));
570 	return;
571     }
572 
573     if (p_verbose >= 13 || debug_break_level > 0)
574     {
575 	int	save_msg_silent = msg_silent;
576 
577 	saved_IObuff = vim_strsave(IObuff);
578 	if (debug_break_level > 0)
579 	    msg_silent = FALSE;		/* display messages */
580 	else
581 	    verbose_enter();
582 	++no_wait_return;
583 	if (debug_break_level > 0 || *p_vfile == NUL)
584 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
585 	smsg(was_finished
586 		    ? (char_u *)_("Exception finished: %s")
587 		    : (char_u *)_("Exception discarded: %s"),
588 		excp->value);
589 	msg_puts((char_u *)"\n");   /* don't overwrite this either */
590 	if (debug_break_level > 0 || *p_vfile == NUL)
591 	    cmdline_row = msg_row;
592 	--no_wait_return;
593 	if (debug_break_level > 0)
594 	    msg_silent = save_msg_silent;
595 	else
596 	    verbose_leave();
597 	STRCPY(IObuff, saved_IObuff);
598 	vim_free(saved_IObuff);
599     }
600     if (excp->type != ET_INTERRUPT)
601 	vim_free(excp->value);
602     if (excp->type == ET_ERROR)
603 	free_msglist(excp->messages);
604     vim_free(excp->throw_name);
605     vim_free(excp);
606 }
607 
608 /*
609  * Discard the exception currently being thrown.
610  */
611     void
612 discard_current_exception()
613 {
614     discard_exception(current_exception, FALSE);
615     current_exception = NULL;
616     did_throw = FALSE;
617     need_rethrow = FALSE;
618 }
619 
620 /*
621  * Put an exception on the caught stack.
622  */
623     static void
624 catch_exception(excp)
625     except_T	*excp;
626 {
627     excp->caught = caught_stack;
628     caught_stack = excp;
629     set_vim_var_string(VV_EXCEPTION, excp->value, -1);
630     if (*excp->throw_name != NUL)
631     {
632 	if (excp->throw_lnum != 0)
633 	    vim_snprintf((char *)IObuff, IOSIZE, _("%s, line %ld"),
634 				    excp->throw_name, (long)excp->throw_lnum);
635 	else
636 	    vim_snprintf((char *)IObuff, IOSIZE, "%s", excp->throw_name);
637 	set_vim_var_string(VV_THROWPOINT, IObuff, -1);
638     }
639     else
640 	/* throw_name not set on an exception from a command that was typed. */
641 	set_vim_var_string(VV_THROWPOINT, NULL, -1);
642 
643     if (p_verbose >= 13 || debug_break_level > 0)
644     {
645 	int	save_msg_silent = msg_silent;
646 
647 	if (debug_break_level > 0)
648 	    msg_silent = FALSE;		/* display messages */
649 	else
650 	    verbose_enter();
651 	++no_wait_return;
652 	if (debug_break_level > 0 || *p_vfile == NUL)
653 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
654 
655 	smsg((char_u *)_("Exception caught: %s"), excp->value);
656 	msg_puts((char_u *)"\n");   /* don't overwrite this either */
657 
658 	if (debug_break_level > 0 || *p_vfile == NUL)
659 	    cmdline_row = msg_row;
660 	--no_wait_return;
661 	if (debug_break_level > 0)
662 	    msg_silent = save_msg_silent;
663 	else
664 	    verbose_leave();
665     }
666 }
667 
668 /*
669  * Remove an exception from the caught stack.
670  */
671     static void
672 finish_exception(excp)
673     except_T	*excp;
674 {
675     if (excp != caught_stack)
676 	EMSG(_(e_internal));
677     caught_stack = caught_stack->caught;
678     if (caught_stack != NULL)
679     {
680 	set_vim_var_string(VV_EXCEPTION, caught_stack->value, -1);
681 	if (*caught_stack->throw_name != NUL)
682 	{
683 	    if (caught_stack->throw_lnum != 0)
684 		vim_snprintf((char *)IObuff, IOSIZE,
685 			_("%s, line %ld"), caught_stack->throw_name,
686 			(long)caught_stack->throw_lnum);
687 	    else
688 		vim_snprintf((char *)IObuff, IOSIZE, "%s",
689 						    caught_stack->throw_name);
690 	    set_vim_var_string(VV_THROWPOINT, IObuff, -1);
691 	}
692 	else
693 	    /* throw_name not set on an exception from a command that was
694 	     * typed. */
695 	    set_vim_var_string(VV_THROWPOINT, NULL, -1);
696     }
697     else
698     {
699 	set_vim_var_string(VV_EXCEPTION, NULL, -1);
700 	set_vim_var_string(VV_THROWPOINT, NULL, -1);
701     }
702 
703     /* Discard the exception, but use the finish message for 'verbose'. */
704     discard_exception(excp, TRUE);
705 }
706 
707 /*
708  * Flags specifying the message displayed by report_pending.
709  */
710 #define RP_MAKE		0
711 #define RP_RESUME	1
712 #define RP_DISCARD	2
713 
714 /*
715  * Report information about something pending in a finally clause if required by
716  * the 'verbose' option or when debugging.  "action" tells whether something is
717  * made pending or something pending is resumed or discarded.  "pending" tells
718  * what is pending.  "value" specifies the return value for a pending ":return"
719  * or the exception value for a pending exception.
720  */
721     static void
722 report_pending(action, pending, value)
723     int		action;
724     int		pending;
725     void	*value;
726 {
727     char_u	*mesg;
728     char	*s;
729     int		save_msg_silent;
730 
731 
732     switch (action)
733     {
734 	case RP_MAKE:
735 	    mesg = (char_u *)_("%s made pending");
736 	    break;
737 	case RP_RESUME:
738 	    mesg = (char_u *)_("%s resumed");
739 	    break;
740 	/* case RP_DISCARD: */
741 	default:
742 	    mesg = (char_u *)_("%s discarded");
743 	    break;
744     }
745 
746     switch (pending)
747     {
748 	case CSTP_NONE:
749 	    return;
750 
751 	case CSTP_CONTINUE:
752 	    s = ":continue";
753 	    break;
754 	case CSTP_BREAK:
755 	    s = ":break";
756 	    break;
757 	case CSTP_FINISH:
758 	    s = ":finish";
759 	    break;
760 	case CSTP_RETURN:
761 	    /* ":return" command producing value, allocated */
762 	    s = (char *)get_return_cmd(value);
763 	    break;
764 
765 	default:
766 	    if (pending & CSTP_THROW)
767 	    {
768 		vim_snprintf((char *)IObuff, IOSIZE,
769 						(char *)mesg, _("Exception"));
770 		mesg = vim_strnsave(IObuff, (int)STRLEN(IObuff) + 4);
771 		STRCAT(mesg, ": %s");
772 		s = (char *)((except_T *)value)->value;
773 	    }
774 	    else if ((pending & CSTP_ERROR) && (pending & CSTP_INTERRUPT))
775 		s = _("Error and interrupt");
776 	    else if (pending & CSTP_ERROR)
777 		s = _("Error");
778 	    else /* if (pending & CSTP_INTERRUPT) */
779 		s = _("Interrupt");
780     }
781 
782     save_msg_silent = msg_silent;
783     if (debug_break_level > 0)
784 	msg_silent = FALSE;	/* display messages */
785     ++no_wait_return;
786     msg_scroll = TRUE;		/* always scroll up, don't overwrite */
787     smsg(mesg, (char_u *)s);
788     msg_puts((char_u *)"\n");   /* don't overwrite this either */
789     cmdline_row = msg_row;
790     --no_wait_return;
791     if (debug_break_level > 0)
792 	msg_silent = save_msg_silent;
793 
794     if (pending == CSTP_RETURN)
795 	vim_free(s);
796     else if (pending & CSTP_THROW)
797 	vim_free(mesg);
798 }
799 
800 /*
801  * If something is made pending in a finally clause, report it if required by
802  * the 'verbose' option or when debugging.
803  */
804     void
805 report_make_pending(pending, value)
806     int		pending;
807     void	*value;
808 {
809     if (p_verbose >= 14 || debug_break_level > 0)
810     {
811 	if (debug_break_level <= 0)
812 	    verbose_enter();
813 	report_pending(RP_MAKE, pending, value);
814 	if (debug_break_level <= 0)
815 	    verbose_leave();
816     }
817 }
818 
819 /*
820  * If something pending in a finally clause is resumed at the ":endtry", report
821  * it if required by the 'verbose' option or when debugging.
822  */
823     void
824 report_resume_pending(pending, value)
825     int		pending;
826     void	*value;
827 {
828     if (p_verbose >= 14 || debug_break_level > 0)
829     {
830 	if (debug_break_level <= 0)
831 	    verbose_enter();
832 	report_pending(RP_RESUME, pending, value);
833 	if (debug_break_level <= 0)
834 	    verbose_leave();
835     }
836 }
837 
838 /*
839  * If something pending in a finally clause is discarded, report it if required
840  * by the 'verbose' option or when debugging.
841  */
842     void
843 report_discard_pending(pending, value)
844     int		pending;
845     void	*value;
846 {
847     if (p_verbose >= 14 || debug_break_level > 0)
848     {
849 	if (debug_break_level <= 0)
850 	    verbose_enter();
851 	report_pending(RP_DISCARD, pending, value);
852 	if (debug_break_level <= 0)
853 	    verbose_leave();
854     }
855 }
856 
857 
858 /*
859  * ":if".
860  */
861     void
862 ex_if(eap)
863     exarg_T	*eap;
864 {
865     int		error;
866     int		skip;
867     int		result;
868     struct condstack	*cstack = eap->cstack;
869 
870     if (cstack->cs_idx == CSTACK_LEN - 1)
871 	eap->errmsg = (char_u *)N_("E579: :if nesting too deep");
872     else
873     {
874 	++cstack->cs_idx;
875 	cstack->cs_flags[cstack->cs_idx] = 0;
876 
877 	/*
878 	 * Don't do something after an error, interrupt, or throw, or when there
879 	 * is a surrounding conditional and it was not active.
880 	 */
881 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
882 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
883 
884 	result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
885 
886 	if (!skip && !error)
887 	{
888 	    if (result)
889 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
890 	}
891 	else
892 	    /* set TRUE, so this conditional will never get active */
893 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
894     }
895 }
896 
897 /*
898  * ":endif".
899  */
900     void
901 ex_endif(eap)
902     exarg_T	*eap;
903 {
904     did_endif = TRUE;
905     if (eap->cstack->cs_idx < 0
906 	    || (eap->cstack->cs_flags[eap->cstack->cs_idx]
907 					   & (CSF_WHILE | CSF_FOR | CSF_TRY)))
908 	eap->errmsg = (char_u *)N_("E580: :endif without :if");
909     else
910     {
911 	/*
912 	 * When debugging or a breakpoint was encountered, display the debug
913 	 * prompt (if not already done).  This shows the user that an ":endif"
914 	 * is executed when the ":if" or a previous ":elseif" was not TRUE.
915 	 * Handle a ">quit" debug command as if an interrupt had occurred before
916 	 * the ":endif".  That is, throw an interrupt exception if appropriate.
917 	 * Doing this here prevents an exception for a parsing error being
918 	 * discarded by throwing the interrupt exception later on.
919 	 */
920 	if (!(eap->cstack->cs_flags[eap->cstack->cs_idx] & CSF_TRUE)
921 						    && dbg_check_skipped(eap))
922 	    (void)do_intthrow(eap->cstack);
923 
924 	--eap->cstack->cs_idx;
925     }
926 }
927 
928 /*
929  * ":else" and ":elseif".
930  */
931     void
932 ex_else(eap)
933     exarg_T	*eap;
934 {
935     int		error;
936     int		skip;
937     int		result;
938     struct condstack	*cstack = eap->cstack;
939 
940     /*
941      * Don't do something after an error, interrupt, or throw, or when there is
942      * a surrounding conditional and it was not active.
943      */
944     skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
945 	    && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
946 
947     if (cstack->cs_idx < 0
948 	    || (cstack->cs_flags[cstack->cs_idx]
949 					   & (CSF_WHILE | CSF_FOR | CSF_TRY)))
950     {
951 	if (eap->cmdidx == CMD_else)
952 	{
953 	    eap->errmsg = (char_u *)N_("E581: :else without :if");
954 	    return;
955 	}
956 	eap->errmsg = (char_u *)N_("E582: :elseif without :if");
957 	skip = TRUE;
958     }
959     else if (cstack->cs_flags[cstack->cs_idx] & CSF_ELSE)
960     {
961 	if (eap->cmdidx == CMD_else)
962 	{
963 	    eap->errmsg = (char_u *)N_("E583: multiple :else");
964 	    return;
965 	}
966 	eap->errmsg = (char_u *)N_("E584: :elseif after :else");
967 	skip = TRUE;
968     }
969 
970     /* if skipping or the ":if" was TRUE, reset ACTIVE, otherwise set it */
971     if (skip || cstack->cs_flags[cstack->cs_idx] & CSF_TRUE)
972     {
973 	if (eap->errmsg == NULL)
974 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
975 	skip = TRUE;	/* don't evaluate an ":elseif" */
976     }
977     else
978 	cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE;
979 
980     /*
981      * When debugging or a breakpoint was encountered, display the debug prompt
982      * (if not already done).  This shows the user that an ":else" or ":elseif"
983      * is executed when the ":if" or previous ":elseif" was not TRUE.  Handle
984      * a ">quit" debug command as if an interrupt had occurred before the
985      * ":else" or ":elseif".  That is, set "skip" and throw an interrupt
986      * exception if appropriate.  Doing this here prevents that an exception
987      * for a parsing errors is discarded when throwing the interrupt exception
988      * later on.
989      */
990     if (!skip && dbg_check_skipped(eap) && got_int)
991     {
992 	(void)do_intthrow(cstack);
993 	skip = TRUE;
994     }
995 
996     if (eap->cmdidx == CMD_elseif)
997     {
998 	result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
999 	/* When throwing error exceptions, we want to throw always the first
1000 	 * of several errors in a row.  This is what actually happens when
1001 	 * a conditional error was detected above and there is another failure
1002 	 * when parsing the expression.  Since the skip flag is set in this
1003 	 * case, the parsing error will be ignored by emsg(). */
1004 
1005 	if (!skip && !error)
1006 	{
1007 	    if (result)
1008 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
1009 	    else
1010 		cstack->cs_flags[cstack->cs_idx] = 0;
1011 	}
1012 	else if (eap->errmsg == NULL)
1013 	    /* set TRUE, so this conditional will never get active */
1014 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1015     }
1016     else
1017 	cstack->cs_flags[cstack->cs_idx] |= CSF_ELSE;
1018 }
1019 
1020 /*
1021  * Handle ":while" and ":for".
1022  */
1023     void
1024 ex_while(eap)
1025     exarg_T	*eap;
1026 {
1027     int		error;
1028     int		skip;
1029     int		result;
1030     struct condstack	*cstack = eap->cstack;
1031 
1032     if (cstack->cs_idx == CSTACK_LEN - 1)
1033 	eap->errmsg = (char_u *)N_("E585: :while/:for nesting too deep");
1034     else
1035     {
1036 	/*
1037 	 * The loop flag is set when we have jumped back from the matching
1038 	 * ":endwhile" or ":endfor".  When not set, need to initialise this
1039 	 * cstack entry.
1040 	 */
1041 	if ((cstack->cs_lflags & CSL_HAD_LOOP) == 0)
1042 	{
1043 	    ++cstack->cs_idx;
1044 	    ++cstack->cs_looplevel;
1045 	    cstack->cs_line[cstack->cs_idx] = -1;
1046 	}
1047 	cstack->cs_flags[cstack->cs_idx] =
1048 			       eap->cmdidx == CMD_while ? CSF_WHILE : CSF_FOR;
1049 
1050 	/*
1051 	 * Don't do something after an error, interrupt, or throw, or when
1052 	 * there is a surrounding conditional and it was not active.
1053 	 */
1054 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1055 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1056 	if (eap->cmdidx == CMD_while)
1057 	{
1058 	    /*
1059 	     * ":while bool-expr"
1060 	     */
1061 	    result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
1062 	}
1063 	else
1064 	{
1065 	    void *fi;
1066 
1067 	    /*
1068 	     * ":for var in list-expr"
1069 	     */
1070 	    if ((cstack->cs_lflags & CSL_HAD_LOOP) != 0)
1071 	    {
1072 		/* Jumping here from a ":continue" or ":endfor": use the
1073 		 * previously evaluated list. */
1074 		fi = cstack->cs_forinfo[cstack->cs_idx];
1075 		error = FALSE;
1076 	    }
1077 	    else
1078 	    {
1079 		/* Evaluate the argument and get the info in a structure. */
1080 		fi = eval_for_line(eap->arg, &error, &eap->nextcmd, skip);
1081 		cstack->cs_forinfo[cstack->cs_idx] = fi;
1082 	    }
1083 
1084 	    /* use the element at the start of the list and advance */
1085 	    if (!error && fi != NULL && !skip)
1086 		result = next_for_item(fi, eap->arg);
1087 	    else
1088 		result = FALSE;
1089 
1090 	    if (!result)
1091 	    {
1092 		free_for_info(fi);
1093 		cstack->cs_forinfo[cstack->cs_idx] = NULL;
1094 	    }
1095 	}
1096 
1097 	/*
1098 	 * If this cstack entry was just initialised and is active, set the
1099 	 * loop flag, so do_cmdline() will set the line number in cs_line[].
1100 	 * If executing the command a second time, clear the loop flag.
1101 	 */
1102 	if (!skip && !error && result)
1103 	{
1104 	    cstack->cs_flags[cstack->cs_idx] |= (CSF_ACTIVE | CSF_TRUE);
1105 	    cstack->cs_lflags ^= CSL_HAD_LOOP;
1106 	}
1107 	else
1108 	{
1109 	    cstack->cs_lflags &= ~CSL_HAD_LOOP;
1110 	    /* If the ":while" evaluates to FALSE or ":for" is past the end of
1111 	     * the list, show the debug prompt at the ":endwhile"/":endfor" as
1112 	     * if there was a ":break" in a ":while"/":for" evaluating to
1113 	     * TRUE. */
1114 	    if (!skip && !error)
1115 		cstack->cs_flags[cstack->cs_idx] |= CSF_TRUE;
1116 	}
1117     }
1118 }
1119 
1120 /*
1121  * ":continue"
1122  */
1123     void
1124 ex_continue(eap)
1125     exarg_T	*eap;
1126 {
1127     int		idx;
1128     struct condstack	*cstack = eap->cstack;
1129 
1130     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1131 	eap->errmsg = (char_u *)N_("E586: :continue without :while or :for");
1132     else
1133     {
1134 	/* Try to find the matching ":while".  This might stop at a try
1135 	 * conditional not in its finally clause (which is then to be executed
1136 	 * next).  Therefor, inactivate all conditionals except the ":while"
1137 	 * itself (if reached). */
1138 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1139 	if (idx >= 0 && (cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1140 	{
1141 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1142 
1143 	    /*
1144 	     * Set CSL_HAD_CONT, so do_cmdline() will jump back to the
1145 	     * matching ":while".
1146 	     */
1147 	    cstack->cs_lflags |= CSL_HAD_CONT;	/* let do_cmdline() handle it */
1148 	}
1149 	else
1150 	{
1151 	    /* If a try conditional not in its finally clause is reached first,
1152 	     * make the ":continue" pending for execution at the ":endtry". */
1153 	    cstack->cs_pending[idx] = CSTP_CONTINUE;
1154 	    report_make_pending(CSTP_CONTINUE, NULL);
1155 	}
1156     }
1157 }
1158 
1159 /*
1160  * ":break"
1161  */
1162     void
1163 ex_break(eap)
1164     exarg_T	*eap;
1165 {
1166     int		idx;
1167     struct condstack	*cstack = eap->cstack;
1168 
1169     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1170 	eap->errmsg = (char_u *)N_("E587: :break without :while or :for");
1171     else
1172     {
1173 	/* Inactivate conditionals until the matching ":while" or a try
1174 	 * conditional not in its finally clause (which is then to be
1175 	 * executed next) is found.  In the latter case, make the ":break"
1176 	 * pending for execution at the ":endtry". */
1177 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, TRUE);
1178 	if (idx >= 0 && !(cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1179 	{
1180 	    cstack->cs_pending[idx] = CSTP_BREAK;
1181 	    report_make_pending(CSTP_BREAK, NULL);
1182 	}
1183     }
1184 }
1185 
1186 /*
1187  * ":endwhile" and ":endfor"
1188  */
1189     void
1190 ex_endwhile(eap)
1191     exarg_T	*eap;
1192 {
1193     struct condstack	*cstack = eap->cstack;
1194     int			idx;
1195     char_u		*err;
1196     int			csf;
1197     int			fl;
1198 
1199     if (eap->cmdidx == CMD_endwhile)
1200     {
1201 	err = e_while;
1202 	csf = CSF_WHILE;
1203     }
1204     else
1205     {
1206 	err = e_for;
1207 	csf = CSF_FOR;
1208     }
1209 
1210     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1211 	eap->errmsg = err;
1212     else
1213     {
1214 	fl =  cstack->cs_flags[cstack->cs_idx];
1215 	if (!(fl & csf))
1216 	{
1217 	    /* If we are in a ":while" or ":for" but used the wrong endloop
1218 	     * command, do not rewind to the next enclosing ":for"/":while". */
1219 	    if (fl & CSF_WHILE)
1220 		eap->errmsg = (char_u *)_("E732: Using :endfor with :while");
1221 	    else if (fl & CSF_FOR)
1222 		eap->errmsg = (char_u *)_("E733: Using :endwhile with :for");
1223 	}
1224 	if (!(fl & (CSF_WHILE | CSF_FOR)))
1225 	{
1226 	    if (!(fl & CSF_TRY))
1227 		eap->errmsg = e_endif;
1228 	    else if (fl & CSF_FINALLY)
1229 		eap->errmsg = e_endtry;
1230 	    /* Try to find the matching ":while" and report what's missing. */
1231 	    for (idx = cstack->cs_idx; idx > 0; --idx)
1232 	    {
1233 		fl =  cstack->cs_flags[idx];
1234 		if ((fl & CSF_TRY) && !(fl & CSF_FINALLY))
1235 		{
1236 		    /* Give up at a try conditional not in its finally clause.
1237 		     * Ignore the ":endwhile"/":endfor". */
1238 		    eap->errmsg = err;
1239 		    return;
1240 		}
1241 		if (fl & csf)
1242 		    break;
1243 	    }
1244 	    /* Cleanup and rewind all contained (and unclosed) conditionals. */
1245 	    (void)cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1246 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1247 	}
1248 
1249 	/*
1250 	 * When debugging or a breakpoint was encountered, display the debug
1251 	 * prompt (if not already done).  This shows the user that an
1252 	 * ":endwhile"/":endfor" is executed when the ":while" was not TRUE or
1253 	 * after a ":break".  Handle a ">quit" debug command as if an
1254 	 * interrupt had occurred before the ":endwhile"/":endfor".  That is,
1255 	 * throw an interrupt exception if appropriate.  Doing this here
1256 	 * prevents that an exception for a parsing error is discarded when
1257 	 * throwing the interrupt exception later on.
1258 	 */
1259 	else if (cstack->cs_flags[cstack->cs_idx] & CSF_TRUE
1260 		&& !(cstack->cs_flags[cstack->cs_idx] & CSF_ACTIVE)
1261 		&& dbg_check_skipped(eap))
1262 	    (void)do_intthrow(cstack);
1263 
1264 	/*
1265 	 * Set loop flag, so do_cmdline() will jump back to the matching
1266 	 * ":while" or ":for".
1267 	 */
1268 	cstack->cs_lflags |= CSL_HAD_ENDLOOP;
1269     }
1270 }
1271 
1272 
1273 /*
1274  * ":throw expr"
1275  */
1276     void
1277 ex_throw(eap)
1278     exarg_T	*eap;
1279 {
1280     char_u	*arg = eap->arg;
1281     char_u	*value;
1282 
1283     if (*arg != NUL && *arg != '|' && *arg != '\n')
1284 	value = eval_to_string_skip(arg, &eap->nextcmd, eap->skip);
1285     else
1286     {
1287 	EMSG(_(e_argreq));
1288 	value = NULL;
1289     }
1290 
1291     /* On error or when an exception is thrown during argument evaluation, do
1292      * not throw. */
1293     if (!eap->skip && value != NULL)
1294     {
1295 	if (throw_exception(value, ET_USER, NULL) == FAIL)
1296 	    vim_free(value);
1297 	else
1298 	    do_throw(eap->cstack);
1299     }
1300 }
1301 
1302 /*
1303  * Throw the current exception through the specified cstack.  Common routine
1304  * for ":throw" (user exception) and error and interrupt exceptions.  Also
1305  * used for rethrowing an uncaught exception.
1306  */
1307     void
1308 do_throw(cstack)
1309     struct condstack	*cstack;
1310 {
1311     int		idx;
1312     int		inactivate_try = FALSE;
1313 
1314     /*
1315      * Cleanup and inactivate up to the next surrounding try conditional that
1316      * is not in its finally clause.  Normally, do not inactivate the try
1317      * conditional itself, so that its ACTIVE flag can be tested below.  But
1318      * if a previous error or interrupt has not been converted to an exception,
1319      * inactivate the try conditional, too, as if the conversion had been done,
1320      * and reset the did_emsg or got_int flag, so this won't happen again at
1321      * the next surrounding try conditional.
1322      */
1323     if (did_emsg && !THROW_ON_ERROR)
1324     {
1325 	inactivate_try = TRUE;
1326 	did_emsg = FALSE;
1327     }
1328     if (got_int && !THROW_ON_INTERRUPT)
1329     {
1330 	inactivate_try = TRUE;
1331 	got_int = FALSE;
1332     }
1333     idx = cleanup_conditionals(cstack, 0, inactivate_try);
1334     if (idx >= 0)
1335     {
1336 	/*
1337 	 * If this try conditional is active and we are before its first
1338 	 * ":catch", set THROWN so that the ":catch" commands will check
1339 	 * whether the exception matches.  When the exception came from any of
1340 	 * the catch clauses, it will be made pending at the ":finally" (if
1341 	 * present) and rethrown at the ":endtry".  This will also happen if
1342 	 * the try conditional is inactive.  This is the case when we are
1343 	 * throwing an exception due to an error or interrupt on the way from
1344 	 * a preceding ":continue", ":break", ":return", ":finish", error or
1345 	 * interrupt (not converted to an exception) to the finally clause or
1346 	 * from a preceding throw of a user or error or interrupt exception to
1347 	 * the matching catch clause or the finally clause.
1348 	 */
1349 	if (!(cstack->cs_flags[idx] & CSF_CAUGHT))
1350 	{
1351 	    if (cstack->cs_flags[idx] & CSF_ACTIVE)
1352 		cstack->cs_flags[idx] |= CSF_THROWN;
1353 	    else
1354 		/* THROWN may have already been set for a catchable exception
1355 		 * that has been discarded.  Ensure it is reset for the new
1356 		 * exception. */
1357 		cstack->cs_flags[idx] &= ~CSF_THROWN;
1358 	}
1359 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
1360 	cstack->cs_exception[idx] = current_exception;
1361     }
1362 #if 0
1363     /* TODO: Add optimization below.  Not yet done because of interface
1364      * problems to eval.c and ex_cmds2.c. (Servatius) */
1365     else
1366     {
1367 	/*
1368 	 * There are no catch clauses to check or finally clauses to execute.
1369 	 * End the current script or function.  The exception will be rethrown
1370 	 * in the caller.
1371 	 */
1372 	if (getline_equal(eap->getline, eap->cookie, get_func_line))
1373 	    current_funccal->returned = TRUE;
1374 	elseif (eap->get_func_line == getsourceline)
1375 	    ((struct source_cookie *)eap->cookie)->finished = TRUE;
1376     }
1377 #endif
1378 
1379     did_throw = TRUE;
1380 }
1381 
1382 /*
1383  * ":try"
1384  */
1385     void
1386 ex_try(eap)
1387     exarg_T	*eap;
1388 {
1389     int		skip;
1390     struct condstack	*cstack = eap->cstack;
1391 
1392     if (cstack->cs_idx == CSTACK_LEN - 1)
1393 	eap->errmsg = (char_u *)N_("E601: :try nesting too deep");
1394     else
1395     {
1396 	++cstack->cs_idx;
1397 	++cstack->cs_trylevel;
1398 	cstack->cs_flags[cstack->cs_idx] = CSF_TRY;
1399 	cstack->cs_pending[cstack->cs_idx] = CSTP_NONE;
1400 
1401 	/*
1402 	 * Don't do something after an error, interrupt, or throw, or when there
1403 	 * is a surrounding conditional and it was not active.
1404 	 */
1405 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1406 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1407 
1408 	if (!skip)
1409 	{
1410 	    /* Set ACTIVE and TRUE.  TRUE means that the corresponding ":catch"
1411 	     * commands should check for a match if an exception is thrown and
1412 	     * that the finally clause needs to be executed. */
1413 	    cstack->cs_flags[cstack->cs_idx] |= CSF_ACTIVE | CSF_TRUE;
1414 
1415 	    /*
1416 	     * ":silent!", even when used in a try conditional, disables
1417 	     * displaying of error messages and conversion of errors to
1418 	     * exceptions.  When the silent commands again open a try
1419 	     * conditional, save "emsg_silent" and reset it so that errors are
1420 	     * again converted to exceptions.  The value is restored when that
1421 	     * try conditional is left.  If it is left normally, the commands
1422 	     * following the ":endtry" are again silent.  If it is left by
1423 	     * a ":continue", ":break", ":return", or ":finish", the commands
1424 	     * executed next are again silent.  If it is left due to an
1425 	     * aborting error, an interrupt, or an exception, restoring
1426 	     * "emsg_silent" does not matter since we are already in the
1427 	     * aborting state and/or the exception has already been thrown.
1428 	     * The effect is then just freeing the memory that was allocated
1429 	     * to save the value.
1430 	     */
1431 	    if (emsg_silent)
1432 	    {
1433 		eslist_T	*elem;
1434 
1435 		elem = (eslist_T *)alloc((unsigned)sizeof(struct eslist_elem));
1436 		if (elem == NULL)
1437 		    EMSG(_(e_outofmem));
1438 		else
1439 		{
1440 		    elem->saved_emsg_silent = emsg_silent;
1441 		    elem->next = cstack->cs_emsg_silent_list;
1442 		    cstack->cs_emsg_silent_list = elem;
1443 		    cstack->cs_flags[cstack->cs_idx] |= CSF_SILENT;
1444 		    emsg_silent = 0;
1445 		}
1446 	    }
1447 	}
1448 
1449     }
1450 }
1451 
1452 /*
1453  * ":catch /{pattern}/" and ":catch"
1454  */
1455     void
1456 ex_catch(eap)
1457     exarg_T	*eap;
1458 {
1459     int		idx = 0;
1460     int		give_up = FALSE;
1461     int		skip = FALSE;
1462     int		caught = FALSE;
1463     char_u	*end;
1464     int		save_char = 0;
1465     char_u	*save_cpo;
1466     regmatch_T	regmatch;
1467     int		prev_got_int;
1468     struct condstack	*cstack = eap->cstack;
1469     char_u	*pat;
1470 
1471     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1472     {
1473 	eap->errmsg = (char_u *)N_("E603: :catch without :try");
1474 	give_up = TRUE;
1475     }
1476     else
1477     {
1478 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1479 	{
1480 	    /* Report what's missing if the matching ":try" is not in its
1481 	     * finally clause. */
1482 	    eap->errmsg = get_end_emsg(cstack);
1483 	    skip = TRUE;
1484 	}
1485 	for (idx = cstack->cs_idx; idx > 0; --idx)
1486 	    if (cstack->cs_flags[idx] & CSF_TRY)
1487 		break;
1488 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1489 	{
1490 	    /* Give up for a ":catch" after ":finally" and ignore it.
1491 	     * Just parse. */
1492 	    eap->errmsg = (char_u *)N_("E604: :catch after :finally");
1493 	    give_up = TRUE;
1494 	}
1495 	else
1496 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1497 						       &cstack->cs_looplevel);
1498     }
1499 
1500     if (ends_excmd(*eap->arg))	/* no argument, catch all errors */
1501     {
1502 	pat = (char_u *)".*";
1503 	end = NULL;
1504 	eap->nextcmd = find_nextcmd(eap->arg);
1505     }
1506     else
1507     {
1508 	pat = eap->arg + 1;
1509 	end = skip_regexp(pat, *eap->arg, TRUE, NULL);
1510     }
1511 
1512     if (!give_up)
1513     {
1514 	/*
1515 	 * Don't do something when no exception has been thrown or when the
1516 	 * corresponding try block never got active (because of an inactive
1517 	 * surrounding conditional or after an error or interrupt or throw).
1518 	 */
1519 	if (!did_throw || !(cstack->cs_flags[idx] & CSF_TRUE))
1520 	    skip = TRUE;
1521 
1522 	/*
1523 	 * Check for a match only if an exception is thrown but not caught by
1524 	 * a previous ":catch".  An exception that has replaced a discarded
1525 	 * exception is not checked (THROWN is not set then).
1526 	 */
1527 	if (!skip && (cstack->cs_flags[idx] & CSF_THROWN)
1528 		&& !(cstack->cs_flags[idx] & CSF_CAUGHT))
1529 	{
1530 	    if (end != NULL && *end != NUL && !ends_excmd(*skipwhite(end + 1)))
1531 	    {
1532 		EMSG(_(e_trailing));
1533 		return;
1534 	    }
1535 
1536 	    /* When debugging or a breakpoint was encountered, display the
1537 	     * debug prompt (if not already done) before checking for a match.
1538 	     * This is a helpful hint for the user when the regular expression
1539 	     * matching fails.  Handle a ">quit" debug command as if an
1540 	     * interrupt had occurred before the ":catch".  That is, discard
1541 	     * the original exception, replace it by an interrupt exception,
1542 	     * and don't catch it in this try block. */
1543 	    if (!dbg_check_skipped(eap) || !do_intthrow(cstack))
1544 	    {
1545 		/* Terminate the pattern and avoid the 'l' flag in 'cpoptions'
1546 		 * while compiling it. */
1547 		if (end != NULL)
1548 		{
1549 		    save_char = *end;
1550 		    *end = NUL;
1551 		}
1552 		save_cpo  = p_cpo;
1553 		p_cpo = (char_u *)"";
1554 		regmatch.regprog = vim_regcomp(pat, TRUE);
1555 		regmatch.rm_ic = FALSE;
1556 		if (end != NULL)
1557 		    *end = save_char;
1558 		p_cpo = save_cpo;
1559 		if (regmatch.regprog == NULL)
1560 		    EMSG2(_(e_invarg2), pat);
1561 		else
1562 		{
1563 		    /*
1564 		     * Save the value of got_int and reset it.  We don't want
1565 		     * a previous interruption cancel matching, only hitting
1566 		     * CTRL-C while matching should abort it.
1567 		     */
1568 		    prev_got_int = got_int;
1569 		    got_int = FALSE;
1570 		    caught = vim_regexec_nl(&regmatch, current_exception->value,
1571 			    (colnr_T)0);
1572 		    got_int |= prev_got_int;
1573 		    vim_free(regmatch.regprog);
1574 		}
1575 	    }
1576 	}
1577 
1578 	if (caught)
1579 	{
1580 	    /* Make this ":catch" clause active and reset did_emsg, got_int,
1581 	     * and did_throw.  Put the exception on the caught stack. */
1582 	    cstack->cs_flags[idx] |= CSF_ACTIVE | CSF_CAUGHT;
1583 	    did_emsg = got_int = did_throw = FALSE;
1584 	    catch_exception((except_T *)cstack->cs_exception[idx]);
1585 	    /* It's mandatory that the current exception is stored in the cstack
1586 	     * so that it can be discarded at the next ":catch", ":finally", or
1587 	     * ":endtry" or when the catch clause is left by a ":continue",
1588 	     * ":break", ":return", ":finish", error, interrupt, or another
1589 	     * exception. */
1590 	    if (cstack->cs_exception[cstack->cs_idx] != current_exception)
1591 		EMSG(_(e_internal));
1592 	}
1593 	else
1594 	{
1595 	    /*
1596 	     * If there is a preceding catch clause and it caught the exception,
1597 	     * finish the exception now.  This happens also after errors except
1598 	     * when this ":catch" was after the ":finally" or not within
1599 	     * a ":try".  Make the try conditional inactive so that the
1600 	     * following catch clauses are skipped.  On an error or interrupt
1601 	     * after the preceding try block or catch clause was left by
1602 	     * a ":continue", ":break", ":return", or ":finish", discard the
1603 	     * pending action.
1604 	     */
1605 	    cleanup_conditionals(cstack, CSF_TRY, TRUE);
1606 	}
1607     }
1608 
1609     if (end != NULL)
1610 	eap->nextcmd = find_nextcmd(end);
1611 }
1612 
1613 /*
1614  * ":finally"
1615  */
1616     void
1617 ex_finally(eap)
1618     exarg_T	*eap;
1619 {
1620     int		idx;
1621     int		skip = FALSE;
1622     int		pending = CSTP_NONE;
1623     struct condstack	*cstack = eap->cstack;
1624 
1625     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1626 	eap->errmsg = (char_u *)N_("E606: :finally without :try");
1627     else
1628     {
1629 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1630 	{
1631 	    eap->errmsg = get_end_emsg(cstack);
1632 	    for (idx = cstack->cs_idx - 1; idx > 0; --idx)
1633 		if (cstack->cs_flags[idx] & CSF_TRY)
1634 		    break;
1635 	    /* Make this error pending, so that the commands in the following
1636 	     * finally clause can be executed.  This overrules also a pending
1637 	     * ":continue", ":break", ":return", or ":finish". */
1638 	    pending = CSTP_ERROR;
1639 	}
1640 	else
1641 	    idx = cstack->cs_idx;
1642 
1643 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1644 	{
1645 	    /* Give up for a multiple ":finally" and ignore it. */
1646 	    eap->errmsg = (char_u *)N_("E607: multiple :finally");
1647 	    return;
1648 	}
1649 	rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1650 						       &cstack->cs_looplevel);
1651 
1652 	/*
1653 	 * Don't do something when the corresponding try block never got active
1654 	 * (because of an inactive surrounding conditional or after an error or
1655 	 * interrupt or throw) or for a ":finally" without ":try" or a multiple
1656 	 * ":finally".  After every other error (did_emsg or the conditional
1657 	 * errors detected above) or after an interrupt (got_int) or an
1658 	 * exception (did_throw), the finally clause must be executed.
1659 	 */
1660 	skip = !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1661 
1662 	if (!skip)
1663 	{
1664 	    /* When debugging or a breakpoint was encountered, display the
1665 	     * debug prompt (if not already done).  The user then knows that the
1666 	     * finally clause is executed. */
1667 	    if (dbg_check_skipped(eap))
1668 	    {
1669 		/* Handle a ">quit" debug command as if an interrupt had
1670 		 * occurred before the ":finally".  That is, discard the
1671 		 * original exception and replace it by an interrupt
1672 		 * exception. */
1673 		(void)do_intthrow(cstack);
1674 	    }
1675 
1676 	    /*
1677 	     * If there is a preceding catch clause and it caught the exception,
1678 	     * finish the exception now.  This happens also after errors except
1679 	     * when this is a multiple ":finally" or one not within a ":try".
1680 	     * After an error or interrupt, this also discards a pending
1681 	     * ":continue", ":break", ":finish", or ":return" from the preceding
1682 	     * try block or catch clause.
1683 	     */
1684 	    cleanup_conditionals(cstack, CSF_TRY, FALSE);
1685 
1686 	    /*
1687 	     * Make did_emsg, got_int, did_throw pending.  If set, they overrule
1688 	     * a pending ":continue", ":break", ":return", or ":finish".  Then
1689 	     * we have particularly to discard a pending return value (as done
1690 	     * by the call to cleanup_conditionals() above when did_emsg or
1691 	     * got_int is set).  The pending values are restored by the
1692 	     * ":endtry", except if there is a new error, interrupt, exception,
1693 	     * ":continue", ":break", ":return", or ":finish" in the following
1694 	     * finally clause.  A missing ":endwhile", ":endfor" or ":endif"
1695 	     * detected here is treated as if did_emsg and did_throw had
1696 	     * already been set, respectively in case that the error is not
1697 	     * converted to an exception, did_throw had already been unset.
1698 	     * We must not set did_emsg here since that would suppress the
1699 	     * error message.
1700 	     */
1701 	    if (pending == CSTP_ERROR || did_emsg || got_int || did_throw)
1702 	    {
1703 		if (cstack->cs_pending[cstack->cs_idx] == CSTP_RETURN)
1704 		{
1705 		    report_discard_pending(CSTP_RETURN,
1706 					   cstack->cs_rettv[cstack->cs_idx]);
1707 		    discard_pending_return(cstack->cs_rettv[cstack->cs_idx]);
1708 		}
1709 		if (pending == CSTP_ERROR && !did_emsg)
1710 		    pending |= (THROW_ON_ERROR) ? CSTP_THROW : 0;
1711 		else
1712 		    pending |= did_throw ? CSTP_THROW : 0;
1713 		pending |= did_emsg  ? CSTP_ERROR     : 0;
1714 		pending |= got_int   ? CSTP_INTERRUPT : 0;
1715 		cstack->cs_pending[cstack->cs_idx] = pending;
1716 
1717 		/* It's mandatory that the current exception is stored in the
1718 		 * cstack so that it can be rethrown at the ":endtry" or be
1719 		 * discarded if the finally clause is left by a ":continue",
1720 		 * ":break", ":return", ":finish", error, interrupt, or another
1721 		 * exception.  When emsg() is called for a missing ":endif" or
1722 		 * a missing ":endwhile"/":endfor" detected here, the
1723 		 * exception will be discarded. */
1724 		if (did_throw && cstack->cs_exception[cstack->cs_idx]
1725 							 != current_exception)
1726 		    EMSG(_(e_internal));
1727 	    }
1728 
1729 	    /*
1730 	     * Set CSL_HAD_FINA, so do_cmdline() will reset did_emsg,
1731 	     * got_int, and did_throw and make the finally clause active.
1732 	     * This will happen after emsg() has been called for a missing
1733 	     * ":endif" or a missing ":endwhile"/":endfor" detected here, so
1734 	     * that the following finally clause will be executed even then.
1735 	     */
1736 	    cstack->cs_lflags |= CSL_HAD_FINA;
1737 	}
1738     }
1739 }
1740 
1741 /*
1742  * ":endtry"
1743  */
1744     void
1745 ex_endtry(eap)
1746     exarg_T	*eap;
1747 {
1748     int		idx;
1749     int		skip;
1750     int		rethrow = FALSE;
1751     int		pending = CSTP_NONE;
1752     void	*rettv = NULL;
1753     struct condstack	*cstack = eap->cstack;
1754 
1755     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1756 	eap->errmsg = (char_u *)N_("E602: :endtry without :try");
1757     else
1758     {
1759 	/*
1760 	 * Don't do something after an error, interrupt or throw in the try
1761 	 * block, catch clause, or finally clause preceding this ":endtry" or
1762 	 * when an error or interrupt occurred after a ":continue", ":break",
1763 	 * ":return", or ":finish" in a try block or catch clause preceding this
1764 	 * ":endtry" or when the try block never got active (because of an
1765 	 * inactive surrounding conditional or after an error or interrupt or
1766 	 * throw) or when there is a surrounding conditional and it has been
1767 	 * made inactive by a ":continue", ":break", ":return", or ":finish" in
1768 	 * the finally clause.  The latter case need not be tested since then
1769 	 * anything pending has already been discarded. */
1770 	skip = did_emsg || got_int || did_throw ||
1771 	    !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1772 
1773 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1774 	{
1775 	    eap->errmsg = get_end_emsg(cstack);
1776 	    /* Find the matching ":try" and report what's missing. */
1777 	    idx = cstack->cs_idx;
1778 	    do
1779 		--idx;
1780 	    while (idx > 0 && !(cstack->cs_flags[idx] & CSF_TRY));
1781 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1782 						       &cstack->cs_looplevel);
1783 	    skip = TRUE;
1784 
1785 	    /*
1786 	     * If an exception is being thrown, discard it to prevent it from
1787 	     * being rethrown at the end of this function.  It would be
1788 	     * discarded by the error message, anyway.  Resets did_throw.
1789 	     * This does not affect the script termination due to the error
1790 	     * since "trylevel" is decremented after emsg() has been called.
1791 	     */
1792 	    if (did_throw)
1793 		discard_current_exception();
1794 	}
1795 	else
1796 	{
1797 	    idx = cstack->cs_idx;
1798 
1799 	    /*
1800 	     * If we stopped with the exception currently being thrown at this
1801 	     * try conditional since we didn't know that it doesn't have
1802 	     * a finally clause, we need to rethrow it after closing the try
1803 	     * conditional.
1804 	     */
1805 	    if (did_throw && (cstack->cs_flags[idx] & CSF_TRUE)
1806 		    && !(cstack->cs_flags[idx] & CSF_FINALLY))
1807 		rethrow = TRUE;
1808 	}
1809 
1810 	/* If there was no finally clause, show the user when debugging or
1811 	 * a breakpoint was encountered that the end of the try conditional has
1812 	 * been reached: display the debug prompt (if not already done).  Do
1813 	 * this on normal control flow or when an exception was thrown, but not
1814 	 * on an interrupt or error not converted to an exception or when
1815 	 * a ":break", ":continue", ":return", or ":finish" is pending.  These
1816 	 * actions are carried out immediately.
1817 	 */
1818 	if ((rethrow || (!skip
1819 			&& !(cstack->cs_flags[idx] & CSF_FINALLY)
1820 			&& !cstack->cs_pending[idx]))
1821 		&& dbg_check_skipped(eap))
1822 	{
1823 	    /* Handle a ">quit" debug command as if an interrupt had occurred
1824 	     * before the ":endtry".  That is, throw an interrupt exception and
1825 	     * set "skip" and "rethrow". */
1826 	    if (got_int)
1827 	    {
1828 		skip = TRUE;
1829 		(void)do_intthrow(cstack);
1830 		/* The do_intthrow() call may have reset did_throw or
1831 		 * cstack->cs_pending[idx].*/
1832 		rethrow = FALSE;
1833 		if (did_throw && !(cstack->cs_flags[idx] & CSF_FINALLY))
1834 		    rethrow = TRUE;
1835 	    }
1836 	}
1837 
1838 	/*
1839 	 * If a ":return" is pending, we need to resume it after closing the
1840 	 * try conditional; remember the return value.  If there was a finally
1841 	 * clause making an exception pending, we need to rethrow it.  Make it
1842 	 * the exception currently being thrown.
1843 	 */
1844 	if (!skip)
1845 	{
1846 	    pending = cstack->cs_pending[idx];
1847 	    cstack->cs_pending[idx] = CSTP_NONE;
1848 	    if (pending == CSTP_RETURN)
1849 		rettv = cstack->cs_rettv[idx];
1850 	    else if (pending & CSTP_THROW)
1851 		current_exception = cstack->cs_exception[idx];
1852 	}
1853 
1854 	/*
1855 	 * Discard anything pending on an error, interrupt, or throw in the
1856 	 * finally clause.  If there was no ":finally", discard a pending
1857 	 * ":continue", ":break", ":return", or ":finish" if an error or
1858 	 * interrupt occurred afterwards, but before the ":endtry" was reached.
1859 	 * If an exception was caught by the last of the catch clauses and there
1860 	 * was no finally clause, finish the exception now.  This happens also
1861 	 * after errors except when this ":endtry" is not within a ":try".
1862 	 * Restore "emsg_silent" if it has been reset by this try conditional.
1863 	 */
1864 	(void)cleanup_conditionals(cstack, CSF_TRY | CSF_SILENT, TRUE);
1865 
1866 	--cstack->cs_idx;
1867 	--cstack->cs_trylevel;
1868 
1869 	if (!skip)
1870 	{
1871 	    report_resume_pending(pending,
1872 		    (pending == CSTP_RETURN) ? rettv :
1873 		    (pending & CSTP_THROW) ? (void *)current_exception : NULL);
1874 	    switch (pending)
1875 	    {
1876 		case CSTP_NONE:
1877 		    break;
1878 
1879 		/* Reactivate a pending ":continue", ":break", ":return",
1880 		 * ":finish" from the try block or a catch clause of this try
1881 		 * conditional.  This is skipped, if there was an error in an
1882 		 * (unskipped) conditional command or an interrupt afterwards
1883 		 * or if the finally clause is present and executed a new error,
1884 		 * interrupt, throw, ":continue", ":break", ":return", or
1885 		 * ":finish". */
1886 		case CSTP_CONTINUE:
1887 		    ex_continue(eap);
1888 		    break;
1889 		case CSTP_BREAK:
1890 		    ex_break(eap);
1891 		    break;
1892 		case CSTP_RETURN:
1893 		    do_return(eap, FALSE, FALSE, rettv);
1894 		    break;
1895 		case CSTP_FINISH:
1896 		    do_finish(eap, FALSE);
1897 		    break;
1898 
1899 		/* When the finally clause was entered due to an error,
1900 		 * interrupt or throw (as opposed to a ":continue", ":break",
1901 		 * ":return", or ":finish"), restore the pending values of
1902 		 * did_emsg, got_int, and did_throw.  This is skipped, if there
1903 		 * was a new error, interrupt, throw, ":continue", ":break",
1904 		 * ":return", or ":finish".  in the finally clause. */
1905 		default:
1906 		    if (pending & CSTP_ERROR)
1907 			did_emsg = TRUE;
1908 		    if (pending & CSTP_INTERRUPT)
1909 			got_int = TRUE;
1910 		    if (pending & CSTP_THROW)
1911 			rethrow = TRUE;
1912 		    break;
1913 	    }
1914 	}
1915 
1916 	if (rethrow)
1917 	    /* Rethrow the current exception (within this cstack). */
1918 	    do_throw(cstack);
1919     }
1920 }
1921 
1922 /*
1923  * enter_cleanup() and leave_cleanup()
1924  *
1925  * Functions to be called before/after invoking a sequence of autocommands for
1926  * cleanup for a failed command.  (Failure means here that a call to emsg()
1927  * has been made, an interrupt occurred, or there is an uncaught exception
1928  * from a previous autocommand execution of the same command.)
1929  *
1930  * Call enter_cleanup() with a pointer to a cleanup_T and pass the same
1931  * pointer to leave_cleanup().  The cleanup_T structure stores the pending
1932  * error/interrupt/exception state.
1933  */
1934 
1935 /*
1936  * This function works a bit like ex_finally() except that there was not
1937  * actually an extra try block around the part that failed and an error or
1938  * interrupt has not (yet) been converted to an exception.  This function
1939  * saves the error/interrupt/ exception state and prepares for the call to
1940  * do_cmdline() that is going to be made for the cleanup autocommand
1941  * execution.
1942  */
1943     void
1944 enter_cleanup(csp)
1945     cleanup_T	*csp;
1946 {
1947     int		pending = CSTP_NONE;
1948 
1949     /*
1950      * Postpone did_emsg, got_int, did_throw.  The pending values will be
1951      * restored by leave_cleanup() except if there was an aborting error,
1952      * interrupt, or uncaught exception after this function ends.
1953      */
1954     if (did_emsg || got_int || did_throw || need_rethrow)
1955     {
1956 	csp->pending = (did_emsg     ? CSTP_ERROR     : 0)
1957 		     | (got_int      ? CSTP_INTERRUPT : 0)
1958 		     | (did_throw    ? CSTP_THROW     : 0)
1959 		     | (need_rethrow ? CSTP_THROW     : 0);
1960 
1961 	/* If we are currently throwing an exception (did_throw), save it as
1962 	 * well.  On an error not yet converted to an exception, update
1963 	 * "force_abort" and reset "cause_abort" (as do_errthrow() would do).
1964 	 * This is needed for the do_cmdline() call that is going to be made
1965 	 * for autocommand execution.  We need not save *msg_list because
1966 	 * there is an extra instance for every call of do_cmdline(), anyway.
1967 	 */
1968 	if (did_throw || need_rethrow)
1969 	    csp->exception = current_exception;
1970 	else
1971 	{
1972 	    csp->exception = NULL;
1973 	    if (did_emsg)
1974 	    {
1975 		force_abort |= cause_abort;
1976 		cause_abort = FALSE;
1977 	    }
1978 	}
1979 	did_emsg = got_int = did_throw = need_rethrow = FALSE;
1980 
1981 	/* Report if required by the 'verbose' option or when debugging.  */
1982 	report_make_pending(pending, csp->exception);
1983     }
1984     else
1985     {
1986 	csp->pending = CSTP_NONE;
1987 	csp->exception = NULL;
1988     }
1989 }
1990 
1991 /*
1992  * See comment above enter_cleanup() for how this function is used.
1993  *
1994  * This function is a bit like ex_endtry() except that there was not actually
1995  * an extra try block around the part that failed and an error or interrupt
1996  * had not (yet) been converted to an exception when the cleanup autocommand
1997  * sequence was invoked.
1998  *
1999  * This function has to be called with the address of the cleanup_T structure
2000  * filled by enter_cleanup() as an argument; it restores the error/interrupt/
2001  * exception state saved by that function - except there was an aborting
2002  * error, an interrupt or an uncaught exception during execution of the
2003  * cleanup autocommands.  In the latter case, the saved error/interrupt/
2004  * exception state is discarded.
2005  */
2006     void
2007 leave_cleanup(csp)
2008     cleanup_T	*csp;
2009 {
2010     int		pending = csp->pending;
2011 
2012     if (pending == CSTP_NONE)	/* nothing to do */
2013 	return;
2014 
2015     /* If there was an aborting error, an interrupt, or an uncaught exception
2016      * after the corresponding call to enter_cleanup(), discard what has been
2017      * made pending by it.  Report this to the user if required by the
2018      * 'verbose' option or when debugging. */
2019     if (aborting() || need_rethrow)
2020     {
2021 	if (pending & CSTP_THROW)
2022 	    /* Cancel the pending exception (includes report). */
2023 	    discard_exception((except_T *)csp->exception, FALSE);
2024 	else
2025 	    report_discard_pending(pending, NULL);
2026 
2027 	/* If an error was about to be converted to an exception when
2028 	 * enter_cleanup() was called, free the message list. */
2029 	if (msg_list != NULL)
2030 	{
2031 	    free_msglist(*msg_list);
2032 	    *msg_list = NULL;
2033 	}
2034     }
2035 
2036     /*
2037      * If there was no new error, interrupt, or throw between the calls
2038      * to enter_cleanup() and leave_cleanup(), restore the pending
2039      * error/interrupt/exception state.
2040      */
2041     else
2042     {
2043 	/*
2044 	 * If there was an exception being thrown when enter_cleanup() was
2045 	 * called, we need to rethrow it.  Make it the exception currently
2046 	 * being thrown.
2047 	 */
2048 	if (pending & CSTP_THROW)
2049 	    current_exception = csp->exception;
2050 
2051 	/*
2052 	 * If an error was about to be converted to an exception when
2053 	 * enter_cleanup() was called, let "cause_abort" take the part of
2054 	 * "force_abort" (as done by cause_errthrow()).
2055 	 */
2056 	else if (pending & CSTP_ERROR)
2057 	{
2058 	    cause_abort = force_abort;
2059 	    force_abort = FALSE;
2060 	}
2061 
2062 	/*
2063 	 * Restore the pending values of did_emsg, got_int, and did_throw.
2064 	 */
2065 	if (pending & CSTP_ERROR)
2066 	    did_emsg = TRUE;
2067 	if (pending & CSTP_INTERRUPT)
2068 	    got_int = TRUE;
2069 	if (pending & CSTP_THROW)
2070 	    need_rethrow = TRUE;    /* did_throw will be set by do_one_cmd() */
2071 
2072 	/* Report if required by the 'verbose' option or when debugging. */
2073 	report_resume_pending(pending,
2074 		   (pending & CSTP_THROW) ? (void *)current_exception : NULL);
2075     }
2076 }
2077 
2078 
2079 /*
2080  * Make conditionals inactive and discard what's pending in finally clauses
2081  * until the conditional type searched for or a try conditional not in its
2082  * finally clause is reached.  If this is in an active catch clause, finish
2083  * the caught exception.
2084  * Return the cstack index where the search stopped.
2085  * Values used for "searched_cond" are (CSF_WHILE | CSF_FOR) or CSF_TRY or 0,
2086  * the latter meaning the innermost try conditional not in its finally clause.
2087  * "inclusive" tells whether the conditional searched for should be made
2088  * inactive itself (a try conditional not in its finally claused possibly find
2089  * before is always made inactive).  If "inclusive" is TRUE and
2090  * "searched_cond" is CSF_TRY|CSF_SILENT, the saved former value of
2091  * "emsg_silent", if reset when the try conditional finally reached was
2092  * entered, is restored (unsed by ex_endtry()).  This is normally done only
2093  * when such a try conditional is left.
2094  */
2095     int
2096 cleanup_conditionals(cstack, searched_cond, inclusive)
2097     struct condstack   *cstack;
2098     int		searched_cond;
2099     int		inclusive;
2100 {
2101     int		idx;
2102     int		stop = FALSE;
2103 
2104     for (idx = cstack->cs_idx; idx >= 0; --idx)
2105     {
2106 	if (cstack->cs_flags[idx] & CSF_TRY)
2107 	{
2108 	    /*
2109 	     * Discard anything pending in a finally clause and continue the
2110 	     * search.  There may also be a pending ":continue", ":break",
2111 	     * ":return", or ":finish" before the finally clause.  We must not
2112 	     * discard it, unless an error or interrupt occurred afterwards.
2113 	     */
2114 	    if (did_emsg || got_int || (cstack->cs_flags[idx] & CSF_FINALLY))
2115 	    {
2116 		switch (cstack->cs_pending[idx])
2117 		{
2118 		    case CSTP_NONE:
2119 			break;
2120 
2121 		    case CSTP_CONTINUE:
2122 		    case CSTP_BREAK:
2123 		    case CSTP_FINISH:
2124 			report_discard_pending(cstack->cs_pending[idx], NULL);
2125 			cstack->cs_pending[idx] = CSTP_NONE;
2126 			break;
2127 
2128 		    case CSTP_RETURN:
2129 			report_discard_pending(CSTP_RETURN,
2130 						      cstack->cs_rettv[idx]);
2131 			discard_pending_return(cstack->cs_rettv[idx]);
2132 			cstack->cs_pending[idx] = CSTP_NONE;
2133 			break;
2134 
2135 		    default:
2136 			if (cstack->cs_flags[idx] & CSF_FINALLY)
2137 			{
2138 			    if (cstack->cs_pending[idx] & CSTP_THROW)
2139 			    {
2140 				/* Cancel the pending exception.  This is in the
2141 				 * finally clause, so that the stack of the
2142 				 * caught exceptions is not involved. */
2143 				discard_exception((except_T *)
2144 					cstack->cs_exception[idx],
2145 					FALSE);
2146 			    }
2147 			    else
2148 				report_discard_pending(cstack->cs_pending[idx],
2149 					NULL);
2150 			    cstack->cs_pending[idx] = CSTP_NONE;
2151 			}
2152 			break;
2153 		}
2154 	    }
2155 
2156 	    /*
2157 	     * Stop at a try conditional not in its finally clause.  If this try
2158 	     * conditional is in an active catch clause, finish the caught
2159 	     * exception.
2160 	     */
2161 	    if (!(cstack->cs_flags[idx] & CSF_FINALLY))
2162 	    {
2163 		if ((cstack->cs_flags[idx] & CSF_ACTIVE)
2164 			&& (cstack->cs_flags[idx] & CSF_CAUGHT))
2165 		    finish_exception((except_T *)cstack->cs_exception[idx]);
2166 		/* Stop at this try conditional - except the try block never
2167 		 * got active (because of an inactive surrounding conditional
2168 		 * or when the ":try" appeared after an error or interrupt or
2169 		 * throw). */
2170 		if (cstack->cs_flags[idx] & CSF_TRUE)
2171 		{
2172 		    if (searched_cond == 0 && !inclusive)
2173 			break;
2174 		    stop = TRUE;
2175 		}
2176 	    }
2177 	}
2178 
2179 	/* Stop on the searched conditional type (even when the surrounding
2180 	 * conditional is not active or something has been made pending).
2181 	 * If "inclusive" is TRUE and "searched_cond" is CSF_TRY|CSF_SILENT,
2182 	 * check first whether "emsg_silent" needs to be restored. */
2183 	if (cstack->cs_flags[idx] & searched_cond)
2184 	{
2185 	    if (!inclusive)
2186 		break;
2187 	    stop = TRUE;
2188 	}
2189 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
2190 	if (stop && searched_cond != (CSF_TRY | CSF_SILENT))
2191 	    break;
2192 
2193 	/*
2194 	 * When leaving a try conditinal that reset "emsg_silent" on its entry
2195 	 * after saving the original value, restore that value here and free the
2196 	 * memory used to store it.
2197 	 */
2198 	if ((cstack->cs_flags[idx] & CSF_TRY)
2199 		&& (cstack->cs_flags[idx] & CSF_SILENT))
2200 	{
2201 	    eslist_T	*elem;
2202 
2203 	    elem = cstack->cs_emsg_silent_list;
2204 	    cstack->cs_emsg_silent_list = elem->next;
2205 	    emsg_silent = elem->saved_emsg_silent;
2206 	    vim_free(elem);
2207 	    cstack->cs_flags[idx] &= ~CSF_SILENT;
2208 	}
2209 	if (stop)
2210 	    break;
2211     }
2212     return idx;
2213 }
2214 
2215 /*
2216  * Return an appropriate error message for a missing endwhile/endfor/endif.
2217  */
2218    static char_u *
2219 get_end_emsg(cstack)
2220     struct condstack	*cstack;
2221 {
2222     if (cstack->cs_flags[cstack->cs_idx] & CSF_WHILE)
2223 	return e_endwhile;
2224     if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2225 	return e_endfor;
2226     return e_endif;
2227 }
2228 
2229 
2230 /*
2231  * Rewind conditionals until index "idx" is reached.  "cond_type" and
2232  * "cond_level" specify a conditional type and the address of a level variable
2233  * which is to be decremented with each skipped conditional of the specified
2234  * type.
2235  * Also free "for info" structures where needed.
2236  */
2237     void
2238 rewind_conditionals(cstack, idx, cond_type, cond_level)
2239     struct condstack   *cstack;
2240     int		idx;
2241     int		cond_type;
2242     int		*cond_level;
2243 {
2244     while (cstack->cs_idx > idx)
2245     {
2246 	if (cstack->cs_flags[cstack->cs_idx] & cond_type)
2247 	    --*cond_level;
2248 	if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2249 	    free_for_info(cstack->cs_forinfo[cstack->cs_idx]);
2250 	--cstack->cs_idx;
2251     }
2252 }
2253 
2254 /*
2255  * ":endfunction" when not after a ":function"
2256  */
2257 /*ARGSUSED*/
2258     void
2259 ex_endfunction(eap)
2260     exarg_T	*eap;
2261 {
2262     EMSG(_("E193: :endfunction not inside a function"));
2263 }
2264 
2265 /*
2266  * Return TRUE if the string "p" looks like a ":while" or ":for" command.
2267  */
2268     int
2269 has_loop_cmd(p)
2270     char_u	*p;
2271 {
2272     p = skipwhite(p);
2273     while (*p == ':')
2274 	p = skipwhite(p + 1);
2275     if ((p[0] == 'w' && p[1] == 'h')
2276 	    || (p[0] == 'f' && p[1] == 'o' && p[2] == 'r'))
2277 	return TRUE;
2278     return FALSE;
2279 }
2280 
2281 #endif /* FEAT_EVAL */
2282