xref: /vim-8.2.3635/src/ex_eval.c (revision 00a927d6)
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_ERROR_TRUE
64 # define THROW_ON_INTERRUPT	TRUE
65 # define THROW_ON_INTERRUPT_TRUE
66 #endif
67 
68 static void	catch_exception __ARGS((except_T *excp));
69 static void	finish_exception __ARGS((except_T *excp));
70 static void	discard_exception __ARGS((except_T *excp, int was_finished));
71 static void	report_pending __ARGS((int action, int pending, void *value));
72 
73 /*
74  * When several errors appear in a row, setting "force_abort" is delayed until
75  * the failing command returned.  "cause_abort" is set to TRUE meanwhile, in
76  * order to indicate that situation.  This is useful when "force_abort" was set
77  * during execution of a function call from an expression: the aborting of the
78  * expression evaluation is done without producing any error messages, but all
79  * error messages on parsing errors during the expression evaluation are given
80  * (even if a try conditional is active).
81  */
82 static int cause_abort = FALSE;
83 
84 /*
85  * Return TRUE when immediately aborting on error, or when an interrupt
86  * occurred or an exception was thrown but not caught.  Use for ":{range}call"
87  * to check whether an aborted function that does not handle a range itself
88  * should be called again for the next line in the range.  Also used for
89  * cancelling expression evaluation after a function call caused an immediate
90  * abort.  Note that the first emsg() call temporarily resets "force_abort"
91  * until the throw point for error messages has been reached.  That is, during
92  * cancellation of an expression evaluation after an aborting function call or
93  * due to a parsing error, aborting() always returns the same value.
94  */
95     int
96 aborting()
97 {
98     return (did_emsg && force_abort) || got_int || did_throw;
99 }
100 
101 /*
102  * The value of "force_abort" is temporarily reset by the first emsg() call
103  * during an expression evaluation, and "cause_abort" is used instead.  It might
104  * be necessary to restore "force_abort" even before the throw point for the
105  * error message has been reached.  update_force_abort() should be called then.
106  */
107     void
108 update_force_abort()
109 {
110     if (cause_abort)
111 	force_abort = TRUE;
112 }
113 
114 /*
115  * Return TRUE if a command with a subcommand resulting in "retcode" should
116  * abort the script processing.  Can be used to suppress an autocommand after
117  * execution of a failing subcommand as long as the error message has not been
118  * displayed and actually caused the abortion.
119  */
120     int
121 should_abort(retcode)
122     int		retcode;
123 {
124     return ((retcode == FAIL && trylevel != 0 && !emsg_silent) || aborting());
125 }
126 
127 /*
128  * Return TRUE if a function with the "abort" flag should not be considered
129  * ended on an error.  This means that parsing commands is continued in order
130  * to find finally clauses to be executed, and that some errors in skipped
131  * commands are still reported.
132  */
133     int
134 aborted_in_try()
135 {
136     /* This function is only called after an error.  In this case, "force_abort"
137      * determines whether searching for finally clauses is necessary. */
138     return force_abort;
139 }
140 
141 /*
142  * cause_errthrow(): Cause a throw of an error exception if appropriate.
143  * Return TRUE if the error message should not be displayed by emsg().
144  * Sets "ignore", if the emsg() call should be ignored completely.
145  *
146  * When several messages appear in the same command, the first is usually the
147  * most specific one and used as the exception value.  The "severe" flag can be
148  * set to TRUE, if a later but severer message should be used instead.
149  */
150     int
151 cause_errthrow(mesg, severe, ignore)
152     char_u	*mesg;
153     int		severe;
154     int		*ignore;
155 {
156     struct msglist *elem;
157     struct msglist **plist;
158 
159     /*
160      * Do nothing when displaying the interrupt message or reporting an
161      * uncaught exception (which has already been discarded then) at the top
162      * level.  Also when no exception can be thrown.  The message will be
163      * displayed by emsg().
164      */
165     if (suppress_errthrow)
166 	return FALSE;
167 
168     /*
169      * If emsg() has not been called previously, temporarily reset
170      * "force_abort" until the throw point for error messages has been
171      * reached.  This ensures that aborting() returns the same value for all
172      * errors that appear in the same command.  This means particularly that
173      * for parsing errors during expression evaluation emsg() will be called
174      * multiply, even when the expression is evaluated from a finally clause
175      * that was activated due to an aborting error, interrupt, or exception.
176      */
177     if (!did_emsg)
178     {
179 	cause_abort = force_abort;
180 	force_abort = FALSE;
181     }
182 
183     /*
184      * If no try conditional is active and no exception is being thrown and
185      * there has not been an error in a try conditional or a throw so far, do
186      * nothing (for compatibility of non-EH scripts).  The message will then
187      * be displayed by emsg().  When ":silent!" was used and we are not
188      * currently throwing an exception, do nothing.  The message text will
189      * then be stored to v:errmsg by emsg() without displaying it.
190      */
191     if (((trylevel == 0 && !cause_abort) || emsg_silent) && !did_throw)
192 	return FALSE;
193 
194     /*
195      * Ignore an interrupt message when inside a try conditional or when an
196      * exception is being thrown or when an error in a try conditional or
197      * throw has been detected previously.  This is important in order that an
198      * interrupt exception is catchable by the innermost try conditional and
199      * not replaced by an interrupt message error exception.
200      */
201     if (mesg == (char_u *)_(e_interr))
202     {
203 	*ignore = TRUE;
204 	return TRUE;
205     }
206 
207     /*
208      * Ensure that all commands in nested function calls and sourced files
209      * are aborted immediately.
210      */
211     cause_abort = TRUE;
212 
213     /*
214      * When an exception is being thrown, some commands (like conditionals) are
215      * not skipped.  Errors in those commands may affect what of the subsequent
216      * commands are regarded part of catch and finally clauses.  Catching the
217      * exception would then cause execution of commands not intended by the
218      * user, who wouldn't even get aware of the problem.  Therefor, discard the
219      * exception currently being thrown to prevent it from being caught.  Just
220      * execute finally clauses and terminate.
221      */
222     if (did_throw)
223     {
224 	/* When discarding an interrupt exception, reset got_int to prevent the
225 	 * same interrupt being converted to an exception again and discarding
226 	 * the error exception we are about to throw here. */
227 	if (current_exception->type == ET_INTERRUPT)
228 	    got_int = FALSE;
229 	discard_current_exception();
230     }
231 
232 #ifdef THROW_TEST
233     if (!THROW_ON_ERROR)
234     {
235 	/*
236 	 * Print error message immediately without searching for a matching
237 	 * catch clause; just finally clauses are executed before the script
238 	 * is terminated.
239 	 */
240 	return FALSE;
241     }
242     else
243 #endif
244     {
245 	/*
246 	 * Prepare the throw of an error exception, so that everything will
247 	 * be aborted (except for executing finally clauses), until the error
248 	 * exception is caught; if still uncaught at the top level, the error
249 	 * message will be displayed and the script processing terminated
250 	 * then.  -  This function has no access to the conditional stack.
251 	 * Thus, the actual throw is made after the failing command has
252 	 * returned.  -  Throw only the first of several errors in a row, except
253 	 * a severe error is following.
254 	 */
255 	if (msg_list != NULL)
256 	{
257 	    plist = msg_list;
258 	    while (*plist != NULL)
259 		plist = &(*plist)->next;
260 
261 	    elem = (struct msglist *)alloc((unsigned)sizeof(struct msglist));
262 	    if (elem == NULL)
263 	    {
264 		suppress_errthrow = TRUE;
265 		EMSG(_(e_outofmem));
266 	    }
267 	    else
268 	    {
269 		elem->msg = vim_strsave(mesg);
270 		if (elem->msg == NULL)
271 		{
272 		    vim_free(elem);
273 		    suppress_errthrow = TRUE;
274 		    EMSG(_(e_outofmem));
275 		}
276 		else
277 		{
278 		    elem->next = NULL;
279 		    elem->throw_msg = NULL;
280 		    *plist = elem;
281 		    if (plist == msg_list || severe)
282 		    {
283 			char_u	    *tmsg;
284 
285 			/* Skip the extra "Vim " prefix for message "E458". */
286 			tmsg = elem->msg;
287 			if (STRNCMP(tmsg, "Vim E", 5) == 0
288 				&& VIM_ISDIGIT(tmsg[5])
289 				&& VIM_ISDIGIT(tmsg[6])
290 				&& VIM_ISDIGIT(tmsg[7])
291 				&& tmsg[8] == ':'
292 				&& tmsg[9] == ' ')
293 			    (*msg_list)->throw_msg = &tmsg[4];
294 			else
295 			    (*msg_list)->throw_msg = tmsg;
296 		    }
297 		}
298 	    }
299 	}
300 	return TRUE;
301     }
302 }
303 
304 /*
305  * Free a "msg_list" and the messages it contains.
306  */
307     static void
308 free_msglist(l)
309     struct msglist  *l;
310 {
311     struct msglist  *messages, *next;
312 
313     messages = l;
314     while (messages != NULL)
315     {
316 	next = messages->next;
317 	vim_free(messages->msg);
318 	vim_free(messages);
319 	messages = next;
320     }
321 }
322 
323 /*
324  * Throw the message specified in the call to cause_errthrow() above as an
325  * error exception.  If cstack is NULL, postpone the throw until do_cmdline()
326  * has returned (see do_one_cmd()).
327  */
328     void
329 do_errthrow(cstack, cmdname)
330     struct condstack	*cstack;
331     char_u		*cmdname;
332 {
333     /*
334      * Ensure that all commands in nested function calls and sourced files
335      * are aborted immediately.
336      */
337     if (cause_abort)
338     {
339 	cause_abort = FALSE;
340 	force_abort = TRUE;
341     }
342 
343     /* If no exception is to be thrown or the conversion should be done after
344      * returning to a previous invocation of do_one_cmd(), do nothing. */
345     if (msg_list == NULL || *msg_list == NULL)
346 	return;
347 
348     if (throw_exception(*msg_list, ET_ERROR, cmdname) == FAIL)
349 	free_msglist(*msg_list);
350     else
351     {
352 	if (cstack != NULL)
353 	    do_throw(cstack);
354 	else
355 	    need_rethrow = TRUE;
356     }
357     *msg_list = NULL;
358 }
359 
360 /*
361  * do_intthrow(): Replace the current exception by an interrupt or interrupt
362  * exception if appropriate.  Return TRUE if the current exception is discarded,
363  * FALSE otherwise.
364  */
365     int
366 do_intthrow(cstack)
367     struct condstack	*cstack;
368 {
369     /*
370      * If no interrupt occurred or no try conditional is active and no exception
371      * is being thrown, do nothing (for compatibility of non-EH scripts).
372      */
373     if (!got_int || (trylevel == 0 && !did_throw))
374 	return FALSE;
375 
376 #ifdef THROW_TEST	/* avoid warning for condition always true */
377     if (!THROW_ON_INTERRUPT)
378     {
379 	/*
380 	 * The interrupt aborts everything except for executing finally clauses.
381 	 * Discard any user or error or interrupt exception currently being
382 	 * thrown.
383 	 */
384 	if (did_throw)
385 	    discard_current_exception();
386     }
387     else
388 #endif
389     {
390 	/*
391 	 * Throw an interrupt exception, so that everything will be aborted
392 	 * (except for executing finally clauses), until the interrupt exception
393 	 * is caught; if still uncaught at the top level, the script processing
394 	 * will be terminated then.  -  If an interrupt exception is already
395 	 * being thrown, do nothing.
396 	 *
397 	 */
398 	if (did_throw)
399 	{
400 	    if (current_exception->type == ET_INTERRUPT)
401 		return FALSE;
402 
403 	    /* An interrupt exception replaces any user or error exception. */
404 	    discard_current_exception();
405 	}
406 	if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) != FAIL)
407 	    do_throw(cstack);
408     }
409 
410     return TRUE;
411 }
412 
413 
414 /*
415  * Throw a new exception.  Return FAIL when out of memory or it was tried to
416  * throw an illegal user exception.  "value" is the exception string for a user
417  * or interrupt exception, or points to a message list in case of an error
418  * exception.
419  */
420     static int
421 throw_exception(value, type, cmdname)
422     void	*value;
423     int		type;
424     char_u	*cmdname;
425 {
426     except_T	*excp;
427     char_u	*p, *mesg, *val;
428     int		cmdlen;
429 
430     /*
431      * Disallow faking Interrupt or error exceptions as user exceptions.  They
432      * would be treated differently from real interrupt or error exceptions when
433      * no active try block is found, see do_cmdline().
434      */
435     if (type == ET_USER)
436     {
437 	if (STRNCMP((char_u *)value, "Vim", 3) == 0 &&
438 		(((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':' ||
439 		 ((char_u *)value)[3] == '('))
440 	{
441 	    EMSG(_("E608: Cannot :throw exceptions with 'Vim' prefix"));
442 	    goto fail;
443 	}
444     }
445 
446     excp = (except_T *)alloc((unsigned)sizeof(except_T));
447     if (excp == NULL)
448 	goto nomem;
449 
450     if (type == ET_ERROR)
451     {
452 	/* Store the original message and prefix the exception value with
453 	 * "Vim:" or, if a command name is given, "Vim(cmdname):". */
454 	excp->messages = (struct msglist *)value;
455 	mesg = excp->messages->throw_msg;
456 	if (cmdname != NULL && *cmdname != NUL)
457 	{
458 	    cmdlen = (int)STRLEN(cmdname);
459 	    excp->value = vim_strnsave((char_u *)"Vim(",
460 					   4 + cmdlen + 2 + (int)STRLEN(mesg));
461 	    if (excp->value == NULL)
462 		goto nomem;
463 	    STRCPY(&excp->value[4], cmdname);
464 	    STRCPY(&excp->value[4 + cmdlen], "):");
465 	    val = excp->value + 4 + cmdlen + 2;
466 	}
467 	else
468 	{
469 	    excp->value = vim_strnsave((char_u *)"Vim:", 4 + (int)STRLEN(mesg));
470 	    if (excp->value == NULL)
471 		goto nomem;
472 	    val = excp->value + 4;
473 	}
474 
475 	/* msg_add_fname may have been used to prefix the message with a file
476 	 * name in quotes.  In the exception value, put the file name in
477 	 * parentheses and move it to the end. */
478 	for (p = mesg; ; p++)
479 	{
480 	    if (*p == NUL
481 		    || (*p == 'E'
482 			&& VIM_ISDIGIT(p[1])
483 			&& (p[2] == ':'
484 			    || (VIM_ISDIGIT(p[2])
485 				&& (p[3] == ':'
486 				    || (VIM_ISDIGIT(p[3])
487 					&& p[4] == ':'))))))
488 	    {
489 		if (*p == NUL || p == mesg)
490 		    STRCAT(val, mesg);  /* 'E123' missing or at beginning */
491 		else
492 		{
493 		    /* '"filename" E123: message text' */
494 		    if (mesg[0] != '"' || p-2 < &mesg[1] ||
495 			    p[-2] != '"' || p[-1] != ' ')
496 			/* "E123:" is part of the file name. */
497 			continue;
498 
499 		    STRCAT(val, p);
500 		    p[-2] = NUL;
501 		    sprintf((char *)(val + STRLEN(p)), " (%s)", &mesg[1]);
502 		    p[-2] = '"';
503 		}
504 		break;
505 	    }
506 	}
507     }
508     else
509 	excp->value = value;
510 
511     excp->type = type;
512     excp->throw_name = vim_strsave(sourcing_name == NULL
513 					      ? (char_u *)"" : sourcing_name);
514     if (excp->throw_name == NULL)
515     {
516 	if (type == ET_ERROR)
517 	    vim_free(excp->value);
518 	goto nomem;
519     }
520     excp->throw_lnum = sourcing_lnum;
521 
522     if (p_verbose >= 13 || debug_break_level > 0)
523     {
524 	int	save_msg_silent = msg_silent;
525 
526 	if (debug_break_level > 0)
527 	    msg_silent = FALSE;		/* display messages */
528 	else
529 	    verbose_enter();
530 	++no_wait_return;
531 	if (debug_break_level > 0 || *p_vfile == NUL)
532 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
533 
534 	smsg((char_u *)_("Exception thrown: %s"), excp->value);
535 	msg_puts((char_u *)"\n");   /* don't overwrite this either */
536 
537 	if (debug_break_level > 0 || *p_vfile == NUL)
538 	    cmdline_row = msg_row;
539 	--no_wait_return;
540 	if (debug_break_level > 0)
541 	    msg_silent = save_msg_silent;
542 	else
543 	    verbose_leave();
544     }
545 
546     current_exception = excp;
547     return OK;
548 
549 nomem:
550     vim_free(excp);
551     suppress_errthrow = TRUE;
552     EMSG(_(e_outofmem));
553 fail:
554     current_exception = NULL;
555     return FAIL;
556 }
557 
558 /*
559  * Discard an exception.  "was_finished" is set when the exception has been
560  * caught and the catch clause has been ended normally.
561  */
562     static void
563 discard_exception(excp, was_finished)
564     except_T		*excp;
565     int			was_finished;
566 {
567     char_u		*saved_IObuff;
568 
569     if (excp == NULL)
570     {
571 	EMSG(_(e_internal));
572 	return;
573     }
574 
575     if (p_verbose >= 13 || debug_break_level > 0)
576     {
577 	int	save_msg_silent = msg_silent;
578 
579 	saved_IObuff = vim_strsave(IObuff);
580 	if (debug_break_level > 0)
581 	    msg_silent = FALSE;		/* display messages */
582 	else
583 	    verbose_enter();
584 	++no_wait_return;
585 	if (debug_break_level > 0 || *p_vfile == NUL)
586 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
587 	smsg(was_finished
588 		    ? (char_u *)_("Exception finished: %s")
589 		    : (char_u *)_("Exception discarded: %s"),
590 		excp->value);
591 	msg_puts((char_u *)"\n");   /* don't overwrite this either */
592 	if (debug_break_level > 0 || *p_vfile == NUL)
593 	    cmdline_row = msg_row;
594 	--no_wait_return;
595 	if (debug_break_level > 0)
596 	    msg_silent = save_msg_silent;
597 	else
598 	    verbose_leave();
599 	STRCPY(IObuff, saved_IObuff);
600 	vim_free(saved_IObuff);
601     }
602     if (excp->type != ET_INTERRUPT)
603 	vim_free(excp->value);
604     if (excp->type == ET_ERROR)
605 	free_msglist(excp->messages);
606     vim_free(excp->throw_name);
607     vim_free(excp);
608 }
609 
610 /*
611  * Discard the exception currently being thrown.
612  */
613     void
614 discard_current_exception()
615 {
616     discard_exception(current_exception, FALSE);
617     current_exception = NULL;
618     did_throw = FALSE;
619     need_rethrow = FALSE;
620 }
621 
622 /*
623  * Put an exception on the caught stack.
624  */
625     static void
626 catch_exception(excp)
627     except_T	*excp;
628 {
629     excp->caught = caught_stack;
630     caught_stack = excp;
631     set_vim_var_string(VV_EXCEPTION, excp->value, -1);
632     if (*excp->throw_name != NUL)
633     {
634 	if (excp->throw_lnum != 0)
635 	    vim_snprintf((char *)IObuff, IOSIZE, _("%s, line %ld"),
636 				    excp->throw_name, (long)excp->throw_lnum);
637 	else
638 	    vim_snprintf((char *)IObuff, IOSIZE, "%s", excp->throw_name);
639 	set_vim_var_string(VV_THROWPOINT, IObuff, -1);
640     }
641     else
642 	/* throw_name not set on an exception from a command that was typed. */
643 	set_vim_var_string(VV_THROWPOINT, NULL, -1);
644 
645     if (p_verbose >= 13 || debug_break_level > 0)
646     {
647 	int	save_msg_silent = msg_silent;
648 
649 	if (debug_break_level > 0)
650 	    msg_silent = FALSE;		/* display messages */
651 	else
652 	    verbose_enter();
653 	++no_wait_return;
654 	if (debug_break_level > 0 || *p_vfile == NUL)
655 	    msg_scroll = TRUE;	    /* always scroll up, don't overwrite */
656 
657 	smsg((char_u *)_("Exception caught: %s"), excp->value);
658 	msg_puts((char_u *)"\n");   /* don't overwrite this either */
659 
660 	if (debug_break_level > 0 || *p_vfile == NUL)
661 	    cmdline_row = msg_row;
662 	--no_wait_return;
663 	if (debug_break_level > 0)
664 	    msg_silent = save_msg_silent;
665 	else
666 	    verbose_leave();
667     }
668 }
669 
670 /*
671  * Remove an exception from the caught stack.
672  */
673     static void
674 finish_exception(excp)
675     except_T	*excp;
676 {
677     if (excp != caught_stack)
678 	EMSG(_(e_internal));
679     caught_stack = caught_stack->caught;
680     if (caught_stack != NULL)
681     {
682 	set_vim_var_string(VV_EXCEPTION, caught_stack->value, -1);
683 	if (*caught_stack->throw_name != NUL)
684 	{
685 	    if (caught_stack->throw_lnum != 0)
686 		vim_snprintf((char *)IObuff, IOSIZE,
687 			_("%s, line %ld"), caught_stack->throw_name,
688 			(long)caught_stack->throw_lnum);
689 	    else
690 		vim_snprintf((char *)IObuff, IOSIZE, "%s",
691 						    caught_stack->throw_name);
692 	    set_vim_var_string(VV_THROWPOINT, IObuff, -1);
693 	}
694 	else
695 	    /* throw_name not set on an exception from a command that was
696 	     * typed. */
697 	    set_vim_var_string(VV_THROWPOINT, NULL, -1);
698     }
699     else
700     {
701 	set_vim_var_string(VV_EXCEPTION, NULL, -1);
702 	set_vim_var_string(VV_THROWPOINT, NULL, -1);
703     }
704 
705     /* Discard the exception, but use the finish message for 'verbose'. */
706     discard_exception(excp, TRUE);
707 }
708 
709 /*
710  * Flags specifying the message displayed by report_pending.
711  */
712 #define RP_MAKE		0
713 #define RP_RESUME	1
714 #define RP_DISCARD	2
715 
716 /*
717  * Report information about something pending in a finally clause if required by
718  * the 'verbose' option or when debugging.  "action" tells whether something is
719  * made pending or something pending is resumed or discarded.  "pending" tells
720  * what is pending.  "value" specifies the return value for a pending ":return"
721  * or the exception value for a pending exception.
722  */
723     static void
724 report_pending(action, pending, value)
725     int		action;
726     int		pending;
727     void	*value;
728 {
729     char_u	*mesg;
730     char	*s;
731     int		save_msg_silent;
732 
733 
734     switch (action)
735     {
736 	case RP_MAKE:
737 	    mesg = (char_u *)_("%s made pending");
738 	    break;
739 	case RP_RESUME:
740 	    mesg = (char_u *)_("%s resumed");
741 	    break;
742 	/* case RP_DISCARD: */
743 	default:
744 	    mesg = (char_u *)_("%s discarded");
745 	    break;
746     }
747 
748     switch (pending)
749     {
750 	case CSTP_NONE:
751 	    return;
752 
753 	case CSTP_CONTINUE:
754 	    s = ":continue";
755 	    break;
756 	case CSTP_BREAK:
757 	    s = ":break";
758 	    break;
759 	case CSTP_FINISH:
760 	    s = ":finish";
761 	    break;
762 	case CSTP_RETURN:
763 	    /* ":return" command producing value, allocated */
764 	    s = (char *)get_return_cmd(value);
765 	    break;
766 
767 	default:
768 	    if (pending & CSTP_THROW)
769 	    {
770 		vim_snprintf((char *)IObuff, IOSIZE,
771 						(char *)mesg, _("Exception"));
772 		mesg = vim_strnsave(IObuff, (int)STRLEN(IObuff) + 4);
773 		STRCAT(mesg, ": %s");
774 		s = (char *)((except_T *)value)->value;
775 	    }
776 	    else if ((pending & CSTP_ERROR) && (pending & CSTP_INTERRUPT))
777 		s = _("Error and interrupt");
778 	    else if (pending & CSTP_ERROR)
779 		s = _("Error");
780 	    else /* if (pending & CSTP_INTERRUPT) */
781 		s = _("Interrupt");
782     }
783 
784     save_msg_silent = msg_silent;
785     if (debug_break_level > 0)
786 	msg_silent = FALSE;	/* display messages */
787     ++no_wait_return;
788     msg_scroll = TRUE;		/* always scroll up, don't overwrite */
789     smsg(mesg, (char_u *)s);
790     msg_puts((char_u *)"\n");   /* don't overwrite this either */
791     cmdline_row = msg_row;
792     --no_wait_return;
793     if (debug_break_level > 0)
794 	msg_silent = save_msg_silent;
795 
796     if (pending == CSTP_RETURN)
797 	vim_free(s);
798     else if (pending & CSTP_THROW)
799 	vim_free(mesg);
800 }
801 
802 /*
803  * If something is made pending in a finally clause, report it if required by
804  * the 'verbose' option or when debugging.
805  */
806     void
807 report_make_pending(pending, value)
808     int		pending;
809     void	*value;
810 {
811     if (p_verbose >= 14 || debug_break_level > 0)
812     {
813 	if (debug_break_level <= 0)
814 	    verbose_enter();
815 	report_pending(RP_MAKE, pending, value);
816 	if (debug_break_level <= 0)
817 	    verbose_leave();
818     }
819 }
820 
821 /*
822  * If something pending in a finally clause is resumed at the ":endtry", report
823  * it if required by the 'verbose' option or when debugging.
824  */
825     void
826 report_resume_pending(pending, value)
827     int		pending;
828     void	*value;
829 {
830     if (p_verbose >= 14 || debug_break_level > 0)
831     {
832 	if (debug_break_level <= 0)
833 	    verbose_enter();
834 	report_pending(RP_RESUME, pending, value);
835 	if (debug_break_level <= 0)
836 	    verbose_leave();
837     }
838 }
839 
840 /*
841  * If something pending in a finally clause is discarded, report it if required
842  * by the 'verbose' option or when debugging.
843  */
844     void
845 report_discard_pending(pending, value)
846     int		pending;
847     void	*value;
848 {
849     if (p_verbose >= 14 || debug_break_level > 0)
850     {
851 	if (debug_break_level <= 0)
852 	    verbose_enter();
853 	report_pending(RP_DISCARD, pending, value);
854 	if (debug_break_level <= 0)
855 	    verbose_leave();
856     }
857 }
858 
859 
860 /*
861  * ":if".
862  */
863     void
864 ex_if(eap)
865     exarg_T	*eap;
866 {
867     int		error;
868     int		skip;
869     int		result;
870     struct condstack	*cstack = eap->cstack;
871 
872     if (cstack->cs_idx == CSTACK_LEN - 1)
873 	eap->errmsg = (char_u *)N_("E579: :if nesting too deep");
874     else
875     {
876 	++cstack->cs_idx;
877 	cstack->cs_flags[cstack->cs_idx] = 0;
878 
879 	/*
880 	 * Don't do something after an error, interrupt, or throw, or when there
881 	 * is a surrounding conditional and it was not active.
882 	 */
883 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
884 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
885 
886 	result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
887 
888 	if (!skip && !error)
889 	{
890 	    if (result)
891 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
892 	}
893 	else
894 	    /* set TRUE, so this conditional will never get active */
895 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
896     }
897 }
898 
899 /*
900  * ":endif".
901  */
902     void
903 ex_endif(eap)
904     exarg_T	*eap;
905 {
906     did_endif = TRUE;
907     if (eap->cstack->cs_idx < 0
908 	    || (eap->cstack->cs_flags[eap->cstack->cs_idx]
909 					   & (CSF_WHILE | CSF_FOR | CSF_TRY)))
910 	eap->errmsg = (char_u *)N_("E580: :endif without :if");
911     else
912     {
913 	/*
914 	 * When debugging or a breakpoint was encountered, display the debug
915 	 * prompt (if not already done).  This shows the user that an ":endif"
916 	 * is executed when the ":if" or a previous ":elseif" was not TRUE.
917 	 * Handle a ">quit" debug command as if an interrupt had occurred before
918 	 * the ":endif".  That is, throw an interrupt exception if appropriate.
919 	 * Doing this here prevents an exception for a parsing error being
920 	 * discarded by throwing the interrupt exception later on.
921 	 */
922 	if (!(eap->cstack->cs_flags[eap->cstack->cs_idx] & CSF_TRUE)
923 						    && dbg_check_skipped(eap))
924 	    (void)do_intthrow(eap->cstack);
925 
926 	--eap->cstack->cs_idx;
927     }
928 }
929 
930 /*
931  * ":else" and ":elseif".
932  */
933     void
934 ex_else(eap)
935     exarg_T	*eap;
936 {
937     int		error;
938     int		skip;
939     int		result;
940     struct condstack	*cstack = eap->cstack;
941 
942     /*
943      * Don't do something after an error, interrupt, or throw, or when there is
944      * a surrounding conditional and it was not active.
945      */
946     skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
947 	    && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
948 
949     if (cstack->cs_idx < 0
950 	    || (cstack->cs_flags[cstack->cs_idx]
951 					   & (CSF_WHILE | CSF_FOR | CSF_TRY)))
952     {
953 	if (eap->cmdidx == CMD_else)
954 	{
955 	    eap->errmsg = (char_u *)N_("E581: :else without :if");
956 	    return;
957 	}
958 	eap->errmsg = (char_u *)N_("E582: :elseif without :if");
959 	skip = TRUE;
960     }
961     else if (cstack->cs_flags[cstack->cs_idx] & CSF_ELSE)
962     {
963 	if (eap->cmdidx == CMD_else)
964 	{
965 	    eap->errmsg = (char_u *)N_("E583: multiple :else");
966 	    return;
967 	}
968 	eap->errmsg = (char_u *)N_("E584: :elseif after :else");
969 	skip = TRUE;
970     }
971 
972     /* if skipping or the ":if" was TRUE, reset ACTIVE, otherwise set it */
973     if (skip || cstack->cs_flags[cstack->cs_idx] & CSF_TRUE)
974     {
975 	if (eap->errmsg == NULL)
976 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
977 	skip = TRUE;	/* don't evaluate an ":elseif" */
978     }
979     else
980 	cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE;
981 
982     /*
983      * When debugging or a breakpoint was encountered, display the debug prompt
984      * (if not already done).  This shows the user that an ":else" or ":elseif"
985      * is executed when the ":if" or previous ":elseif" was not TRUE.  Handle
986      * a ">quit" debug command as if an interrupt had occurred before the
987      * ":else" or ":elseif".  That is, set "skip" and throw an interrupt
988      * exception if appropriate.  Doing this here prevents that an exception
989      * for a parsing errors is discarded when throwing the interrupt exception
990      * later on.
991      */
992     if (!skip && dbg_check_skipped(eap) && got_int)
993     {
994 	(void)do_intthrow(cstack);
995 	skip = TRUE;
996     }
997 
998     if (eap->cmdidx == CMD_elseif)
999     {
1000 	result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
1001 	/* When throwing error exceptions, we want to throw always the first
1002 	 * of several errors in a row.  This is what actually happens when
1003 	 * a conditional error was detected above and there is another failure
1004 	 * when parsing the expression.  Since the skip flag is set in this
1005 	 * case, the parsing error will be ignored by emsg(). */
1006 
1007 	if (!skip && !error)
1008 	{
1009 	    if (result)
1010 		cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE;
1011 	    else
1012 		cstack->cs_flags[cstack->cs_idx] = 0;
1013 	}
1014 	else if (eap->errmsg == NULL)
1015 	    /* set TRUE, so this conditional will never get active */
1016 	    cstack->cs_flags[cstack->cs_idx] = CSF_TRUE;
1017     }
1018     else
1019 	cstack->cs_flags[cstack->cs_idx] |= CSF_ELSE;
1020 }
1021 
1022 /*
1023  * Handle ":while" and ":for".
1024  */
1025     void
1026 ex_while(eap)
1027     exarg_T	*eap;
1028 {
1029     int		error;
1030     int		skip;
1031     int		result;
1032     struct condstack	*cstack = eap->cstack;
1033 
1034     if (cstack->cs_idx == CSTACK_LEN - 1)
1035 	eap->errmsg = (char_u *)N_("E585: :while/:for nesting too deep");
1036     else
1037     {
1038 	/*
1039 	 * The loop flag is set when we have jumped back from the matching
1040 	 * ":endwhile" or ":endfor".  When not set, need to initialise this
1041 	 * cstack entry.
1042 	 */
1043 	if ((cstack->cs_lflags & CSL_HAD_LOOP) == 0)
1044 	{
1045 	    ++cstack->cs_idx;
1046 	    ++cstack->cs_looplevel;
1047 	    cstack->cs_line[cstack->cs_idx] = -1;
1048 	}
1049 	cstack->cs_flags[cstack->cs_idx] =
1050 			       eap->cmdidx == CMD_while ? CSF_WHILE : CSF_FOR;
1051 
1052 	/*
1053 	 * Don't do something after an error, interrupt, or throw, or when
1054 	 * there is a surrounding conditional and it was not active.
1055 	 */
1056 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1057 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1058 	if (eap->cmdidx == CMD_while)
1059 	{
1060 	    /*
1061 	     * ":while bool-expr"
1062 	     */
1063 	    result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip);
1064 	}
1065 	else
1066 	{
1067 	    void *fi;
1068 
1069 	    /*
1070 	     * ":for var in list-expr"
1071 	     */
1072 	    if ((cstack->cs_lflags & CSL_HAD_LOOP) != 0)
1073 	    {
1074 		/* Jumping here from a ":continue" or ":endfor": use the
1075 		 * previously evaluated list. */
1076 		fi = cstack->cs_forinfo[cstack->cs_idx];
1077 		error = FALSE;
1078 	    }
1079 	    else
1080 	    {
1081 		/* Evaluate the argument and get the info in a structure. */
1082 		fi = eval_for_line(eap->arg, &error, &eap->nextcmd, skip);
1083 		cstack->cs_forinfo[cstack->cs_idx] = fi;
1084 	    }
1085 
1086 	    /* use the element at the start of the list and advance */
1087 	    if (!error && fi != NULL && !skip)
1088 		result = next_for_item(fi, eap->arg);
1089 	    else
1090 		result = FALSE;
1091 
1092 	    if (!result)
1093 	    {
1094 		free_for_info(fi);
1095 		cstack->cs_forinfo[cstack->cs_idx] = NULL;
1096 	    }
1097 	}
1098 
1099 	/*
1100 	 * If this cstack entry was just initialised and is active, set the
1101 	 * loop flag, so do_cmdline() will set the line number in cs_line[].
1102 	 * If executing the command a second time, clear the loop flag.
1103 	 */
1104 	if (!skip && !error && result)
1105 	{
1106 	    cstack->cs_flags[cstack->cs_idx] |= (CSF_ACTIVE | CSF_TRUE);
1107 	    cstack->cs_lflags ^= CSL_HAD_LOOP;
1108 	}
1109 	else
1110 	{
1111 	    cstack->cs_lflags &= ~CSL_HAD_LOOP;
1112 	    /* If the ":while" evaluates to FALSE or ":for" is past the end of
1113 	     * the list, show the debug prompt at the ":endwhile"/":endfor" as
1114 	     * if there was a ":break" in a ":while"/":for" evaluating to
1115 	     * TRUE. */
1116 	    if (!skip && !error)
1117 		cstack->cs_flags[cstack->cs_idx] |= CSF_TRUE;
1118 	}
1119     }
1120 }
1121 
1122 /*
1123  * ":continue"
1124  */
1125     void
1126 ex_continue(eap)
1127     exarg_T	*eap;
1128 {
1129     int		idx;
1130     struct condstack	*cstack = eap->cstack;
1131 
1132     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1133 	eap->errmsg = (char_u *)N_("E586: :continue without :while or :for");
1134     else
1135     {
1136 	/* Try to find the matching ":while".  This might stop at a try
1137 	 * conditional not in its finally clause (which is then to be executed
1138 	 * next).  Therefor, inactivate all conditionals except the ":while"
1139 	 * itself (if reached). */
1140 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1141 	if (idx >= 0 && (cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1142 	{
1143 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1144 
1145 	    /*
1146 	     * Set CSL_HAD_CONT, so do_cmdline() will jump back to the
1147 	     * matching ":while".
1148 	     */
1149 	    cstack->cs_lflags |= CSL_HAD_CONT;	/* let do_cmdline() handle it */
1150 	}
1151 	else
1152 	{
1153 	    /* If a try conditional not in its finally clause is reached first,
1154 	     * make the ":continue" pending for execution at the ":endtry". */
1155 	    cstack->cs_pending[idx] = CSTP_CONTINUE;
1156 	    report_make_pending(CSTP_CONTINUE, NULL);
1157 	}
1158     }
1159 }
1160 
1161 /*
1162  * ":break"
1163  */
1164     void
1165 ex_break(eap)
1166     exarg_T	*eap;
1167 {
1168     int		idx;
1169     struct condstack	*cstack = eap->cstack;
1170 
1171     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1172 	eap->errmsg = (char_u *)N_("E587: :break without :while or :for");
1173     else
1174     {
1175 	/* Inactivate conditionals until the matching ":while" or a try
1176 	 * conditional not in its finally clause (which is then to be
1177 	 * executed next) is found.  In the latter case, make the ":break"
1178 	 * pending for execution at the ":endtry". */
1179 	idx = cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, TRUE);
1180 	if (idx >= 0 && !(cstack->cs_flags[idx] & (CSF_WHILE | CSF_FOR)))
1181 	{
1182 	    cstack->cs_pending[idx] = CSTP_BREAK;
1183 	    report_make_pending(CSTP_BREAK, NULL);
1184 	}
1185     }
1186 }
1187 
1188 /*
1189  * ":endwhile" and ":endfor"
1190  */
1191     void
1192 ex_endwhile(eap)
1193     exarg_T	*eap;
1194 {
1195     struct condstack	*cstack = eap->cstack;
1196     int			idx;
1197     char_u		*err;
1198     int			csf;
1199     int			fl;
1200 
1201     if (eap->cmdidx == CMD_endwhile)
1202     {
1203 	err = e_while;
1204 	csf = CSF_WHILE;
1205     }
1206     else
1207     {
1208 	err = e_for;
1209 	csf = CSF_FOR;
1210     }
1211 
1212     if (cstack->cs_looplevel <= 0 || cstack->cs_idx < 0)
1213 	eap->errmsg = err;
1214     else
1215     {
1216 	fl =  cstack->cs_flags[cstack->cs_idx];
1217 	if (!(fl & csf))
1218 	{
1219 	    /* If we are in a ":while" or ":for" but used the wrong endloop
1220 	     * command, do not rewind to the next enclosing ":for"/":while". */
1221 	    if (fl & CSF_WHILE)
1222 		eap->errmsg = (char_u *)_("E732: Using :endfor with :while");
1223 	    else if (fl & CSF_FOR)
1224 		eap->errmsg = (char_u *)_("E733: Using :endwhile with :for");
1225 	}
1226 	if (!(fl & (CSF_WHILE | CSF_FOR)))
1227 	{
1228 	    if (!(fl & CSF_TRY))
1229 		eap->errmsg = e_endif;
1230 	    else if (fl & CSF_FINALLY)
1231 		eap->errmsg = e_endtry;
1232 	    /* Try to find the matching ":while" and report what's missing. */
1233 	    for (idx = cstack->cs_idx; idx > 0; --idx)
1234 	    {
1235 		fl =  cstack->cs_flags[idx];
1236 		if ((fl & CSF_TRY) && !(fl & CSF_FINALLY))
1237 		{
1238 		    /* Give up at a try conditional not in its finally clause.
1239 		     * Ignore the ":endwhile"/":endfor". */
1240 		    eap->errmsg = err;
1241 		    return;
1242 		}
1243 		if (fl & csf)
1244 		    break;
1245 	    }
1246 	    /* Cleanup and rewind all contained (and unclosed) conditionals. */
1247 	    (void)cleanup_conditionals(cstack, CSF_WHILE | CSF_FOR, FALSE);
1248 	    rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel);
1249 	}
1250 
1251 	/*
1252 	 * When debugging or a breakpoint was encountered, display the debug
1253 	 * prompt (if not already done).  This shows the user that an
1254 	 * ":endwhile"/":endfor" is executed when the ":while" was not TRUE or
1255 	 * after a ":break".  Handle a ">quit" debug command as if an
1256 	 * interrupt had occurred before the ":endwhile"/":endfor".  That is,
1257 	 * throw an interrupt exception if appropriate.  Doing this here
1258 	 * prevents that an exception for a parsing error is discarded when
1259 	 * throwing the interrupt exception later on.
1260 	 */
1261 	else if (cstack->cs_flags[cstack->cs_idx] & CSF_TRUE
1262 		&& !(cstack->cs_flags[cstack->cs_idx] & CSF_ACTIVE)
1263 		&& dbg_check_skipped(eap))
1264 	    (void)do_intthrow(cstack);
1265 
1266 	/*
1267 	 * Set loop flag, so do_cmdline() will jump back to the matching
1268 	 * ":while" or ":for".
1269 	 */
1270 	cstack->cs_lflags |= CSL_HAD_ENDLOOP;
1271     }
1272 }
1273 
1274 
1275 /*
1276  * ":throw expr"
1277  */
1278     void
1279 ex_throw(eap)
1280     exarg_T	*eap;
1281 {
1282     char_u	*arg = eap->arg;
1283     char_u	*value;
1284 
1285     if (*arg != NUL && *arg != '|' && *arg != '\n')
1286 	value = eval_to_string_skip(arg, &eap->nextcmd, eap->skip);
1287     else
1288     {
1289 	EMSG(_(e_argreq));
1290 	value = NULL;
1291     }
1292 
1293     /* On error or when an exception is thrown during argument evaluation, do
1294      * not throw. */
1295     if (!eap->skip && value != NULL)
1296     {
1297 	if (throw_exception(value, ET_USER, NULL) == FAIL)
1298 	    vim_free(value);
1299 	else
1300 	    do_throw(eap->cstack);
1301     }
1302 }
1303 
1304 /*
1305  * Throw the current exception through the specified cstack.  Common routine
1306  * for ":throw" (user exception) and error and interrupt exceptions.  Also
1307  * used for rethrowing an uncaught exception.
1308  */
1309     void
1310 do_throw(cstack)
1311     struct condstack	*cstack;
1312 {
1313     int		idx;
1314     int		inactivate_try = FALSE;
1315 
1316     /*
1317      * Cleanup and inactivate up to the next surrounding try conditional that
1318      * is not in its finally clause.  Normally, do not inactivate the try
1319      * conditional itself, so that its ACTIVE flag can be tested below.  But
1320      * if a previous error or interrupt has not been converted to an exception,
1321      * inactivate the try conditional, too, as if the conversion had been done,
1322      * and reset the did_emsg or got_int flag, so this won't happen again at
1323      * the next surrounding try conditional.
1324      */
1325 #ifndef THROW_ON_ERROR_TRUE
1326     if (did_emsg && !THROW_ON_ERROR)
1327     {
1328 	inactivate_try = TRUE;
1329 	did_emsg = FALSE;
1330     }
1331 #endif
1332 #ifndef THROW_ON_INTERRUPT_TRUE
1333     if (got_int && !THROW_ON_INTERRUPT)
1334     {
1335 	inactivate_try = TRUE;
1336 	got_int = FALSE;
1337     }
1338 #endif
1339     idx = cleanup_conditionals(cstack, 0, inactivate_try);
1340     if (idx >= 0)
1341     {
1342 	/*
1343 	 * If this try conditional is active and we are before its first
1344 	 * ":catch", set THROWN so that the ":catch" commands will check
1345 	 * whether the exception matches.  When the exception came from any of
1346 	 * the catch clauses, it will be made pending at the ":finally" (if
1347 	 * present) and rethrown at the ":endtry".  This will also happen if
1348 	 * the try conditional is inactive.  This is the case when we are
1349 	 * throwing an exception due to an error or interrupt on the way from
1350 	 * a preceding ":continue", ":break", ":return", ":finish", error or
1351 	 * interrupt (not converted to an exception) to the finally clause or
1352 	 * from a preceding throw of a user or error or interrupt exception to
1353 	 * the matching catch clause or the finally clause.
1354 	 */
1355 	if (!(cstack->cs_flags[idx] & CSF_CAUGHT))
1356 	{
1357 	    if (cstack->cs_flags[idx] & CSF_ACTIVE)
1358 		cstack->cs_flags[idx] |= CSF_THROWN;
1359 	    else
1360 		/* THROWN may have already been set for a catchable exception
1361 		 * that has been discarded.  Ensure it is reset for the new
1362 		 * exception. */
1363 		cstack->cs_flags[idx] &= ~CSF_THROWN;
1364 	}
1365 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
1366 	cstack->cs_exception[idx] = current_exception;
1367     }
1368 #if 0
1369     /* TODO: Add optimization below.  Not yet done because of interface
1370      * problems to eval.c and ex_cmds2.c. (Servatius) */
1371     else
1372     {
1373 	/*
1374 	 * There are no catch clauses to check or finally clauses to execute.
1375 	 * End the current script or function.  The exception will be rethrown
1376 	 * in the caller.
1377 	 */
1378 	if (getline_equal(eap->getline, eap->cookie, get_func_line))
1379 	    current_funccal->returned = TRUE;
1380 	elseif (eap->get_func_line == getsourceline)
1381 	    ((struct source_cookie *)eap->cookie)->finished = TRUE;
1382     }
1383 #endif
1384 
1385     did_throw = TRUE;
1386 }
1387 
1388 /*
1389  * ":try"
1390  */
1391     void
1392 ex_try(eap)
1393     exarg_T	*eap;
1394 {
1395     int		skip;
1396     struct condstack	*cstack = eap->cstack;
1397 
1398     if (cstack->cs_idx == CSTACK_LEN - 1)
1399 	eap->errmsg = (char_u *)N_("E601: :try nesting too deep");
1400     else
1401     {
1402 	++cstack->cs_idx;
1403 	++cstack->cs_trylevel;
1404 	cstack->cs_flags[cstack->cs_idx] = CSF_TRY;
1405 	cstack->cs_pending[cstack->cs_idx] = CSTP_NONE;
1406 
1407 	/*
1408 	 * Don't do something after an error, interrupt, or throw, or when there
1409 	 * is a surrounding conditional and it was not active.
1410 	 */
1411 	skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0
1412 		&& !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE));
1413 
1414 	if (!skip)
1415 	{
1416 	    /* Set ACTIVE and TRUE.  TRUE means that the corresponding ":catch"
1417 	     * commands should check for a match if an exception is thrown and
1418 	     * that the finally clause needs to be executed. */
1419 	    cstack->cs_flags[cstack->cs_idx] |= CSF_ACTIVE | CSF_TRUE;
1420 
1421 	    /*
1422 	     * ":silent!", even when used in a try conditional, disables
1423 	     * displaying of error messages and conversion of errors to
1424 	     * exceptions.  When the silent commands again open a try
1425 	     * conditional, save "emsg_silent" and reset it so that errors are
1426 	     * again converted to exceptions.  The value is restored when that
1427 	     * try conditional is left.  If it is left normally, the commands
1428 	     * following the ":endtry" are again silent.  If it is left by
1429 	     * a ":continue", ":break", ":return", or ":finish", the commands
1430 	     * executed next are again silent.  If it is left due to an
1431 	     * aborting error, an interrupt, or an exception, restoring
1432 	     * "emsg_silent" does not matter since we are already in the
1433 	     * aborting state and/or the exception has already been thrown.
1434 	     * The effect is then just freeing the memory that was allocated
1435 	     * to save the value.
1436 	     */
1437 	    if (emsg_silent)
1438 	    {
1439 		eslist_T	*elem;
1440 
1441 		elem = (eslist_T *)alloc((unsigned)sizeof(struct eslist_elem));
1442 		if (elem == NULL)
1443 		    EMSG(_(e_outofmem));
1444 		else
1445 		{
1446 		    elem->saved_emsg_silent = emsg_silent;
1447 		    elem->next = cstack->cs_emsg_silent_list;
1448 		    cstack->cs_emsg_silent_list = elem;
1449 		    cstack->cs_flags[cstack->cs_idx] |= CSF_SILENT;
1450 		    emsg_silent = 0;
1451 		}
1452 	    }
1453 	}
1454 
1455     }
1456 }
1457 
1458 /*
1459  * ":catch /{pattern}/" and ":catch"
1460  */
1461     void
1462 ex_catch(eap)
1463     exarg_T	*eap;
1464 {
1465     int		idx = 0;
1466     int		give_up = FALSE;
1467     int		skip = FALSE;
1468     int		caught = FALSE;
1469     char_u	*end;
1470     int		save_char = 0;
1471     char_u	*save_cpo;
1472     regmatch_T	regmatch;
1473     int		prev_got_int;
1474     struct condstack	*cstack = eap->cstack;
1475     char_u	*pat;
1476 
1477     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1478     {
1479 	eap->errmsg = (char_u *)N_("E603: :catch without :try");
1480 	give_up = TRUE;
1481     }
1482     else
1483     {
1484 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1485 	{
1486 	    /* Report what's missing if the matching ":try" is not in its
1487 	     * finally clause. */
1488 	    eap->errmsg = get_end_emsg(cstack);
1489 	    skip = TRUE;
1490 	}
1491 	for (idx = cstack->cs_idx; idx > 0; --idx)
1492 	    if (cstack->cs_flags[idx] & CSF_TRY)
1493 		break;
1494 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1495 	{
1496 	    /* Give up for a ":catch" after ":finally" and ignore it.
1497 	     * Just parse. */
1498 	    eap->errmsg = (char_u *)N_("E604: :catch after :finally");
1499 	    give_up = TRUE;
1500 	}
1501 	else
1502 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1503 						       &cstack->cs_looplevel);
1504     }
1505 
1506     if (ends_excmd(*eap->arg))	/* no argument, catch all errors */
1507     {
1508 	pat = (char_u *)".*";
1509 	end = NULL;
1510 	eap->nextcmd = find_nextcmd(eap->arg);
1511     }
1512     else
1513     {
1514 	pat = eap->arg + 1;
1515 	end = skip_regexp(pat, *eap->arg, TRUE, NULL);
1516     }
1517 
1518     if (!give_up)
1519     {
1520 	/*
1521 	 * Don't do something when no exception has been thrown or when the
1522 	 * corresponding try block never got active (because of an inactive
1523 	 * surrounding conditional or after an error or interrupt or throw).
1524 	 */
1525 	if (!did_throw || !(cstack->cs_flags[idx] & CSF_TRUE))
1526 	    skip = TRUE;
1527 
1528 	/*
1529 	 * Check for a match only if an exception is thrown but not caught by
1530 	 * a previous ":catch".  An exception that has replaced a discarded
1531 	 * exception is not checked (THROWN is not set then).
1532 	 */
1533 	if (!skip && (cstack->cs_flags[idx] & CSF_THROWN)
1534 		&& !(cstack->cs_flags[idx] & CSF_CAUGHT))
1535 	{
1536 	    if (end != NULL && *end != NUL && !ends_excmd(*skipwhite(end + 1)))
1537 	    {
1538 		EMSG(_(e_trailing));
1539 		return;
1540 	    }
1541 
1542 	    /* When debugging or a breakpoint was encountered, display the
1543 	     * debug prompt (if not already done) before checking for a match.
1544 	     * This is a helpful hint for the user when the regular expression
1545 	     * matching fails.  Handle a ">quit" debug command as if an
1546 	     * interrupt had occurred before the ":catch".  That is, discard
1547 	     * the original exception, replace it by an interrupt exception,
1548 	     * and don't catch it in this try block. */
1549 	    if (!dbg_check_skipped(eap) || !do_intthrow(cstack))
1550 	    {
1551 		/* Terminate the pattern and avoid the 'l' flag in 'cpoptions'
1552 		 * while compiling it. */
1553 		if (end != NULL)
1554 		{
1555 		    save_char = *end;
1556 		    *end = NUL;
1557 		}
1558 		save_cpo  = p_cpo;
1559 		p_cpo = (char_u *)"";
1560 		regmatch.regprog = vim_regcomp(pat, RE_MAGIC + RE_STRING);
1561 		regmatch.rm_ic = FALSE;
1562 		if (end != NULL)
1563 		    *end = save_char;
1564 		p_cpo = save_cpo;
1565 		if (regmatch.regprog == NULL)
1566 		    EMSG2(_(e_invarg2), pat);
1567 		else
1568 		{
1569 		    /*
1570 		     * Save the value of got_int and reset it.  We don't want
1571 		     * a previous interruption cancel matching, only hitting
1572 		     * CTRL-C while matching should abort it.
1573 		     */
1574 		    prev_got_int = got_int;
1575 		    got_int = FALSE;
1576 		    caught = vim_regexec_nl(&regmatch, current_exception->value,
1577 			    (colnr_T)0);
1578 		    got_int |= prev_got_int;
1579 		    vim_free(regmatch.regprog);
1580 		}
1581 	    }
1582 	}
1583 
1584 	if (caught)
1585 	{
1586 	    /* Make this ":catch" clause active and reset did_emsg, got_int,
1587 	     * and did_throw.  Put the exception on the caught stack. */
1588 	    cstack->cs_flags[idx] |= CSF_ACTIVE | CSF_CAUGHT;
1589 	    did_emsg = got_int = did_throw = FALSE;
1590 	    catch_exception((except_T *)cstack->cs_exception[idx]);
1591 	    /* It's mandatory that the current exception is stored in the cstack
1592 	     * so that it can be discarded at the next ":catch", ":finally", or
1593 	     * ":endtry" or when the catch clause is left by a ":continue",
1594 	     * ":break", ":return", ":finish", error, interrupt, or another
1595 	     * exception. */
1596 	    if (cstack->cs_exception[cstack->cs_idx] != current_exception)
1597 		EMSG(_(e_internal));
1598 	}
1599 	else
1600 	{
1601 	    /*
1602 	     * If there is a preceding catch clause and it caught the exception,
1603 	     * finish the exception now.  This happens also after errors except
1604 	     * when this ":catch" was after the ":finally" or not within
1605 	     * a ":try".  Make the try conditional inactive so that the
1606 	     * following catch clauses are skipped.  On an error or interrupt
1607 	     * after the preceding try block or catch clause was left by
1608 	     * a ":continue", ":break", ":return", or ":finish", discard the
1609 	     * pending action.
1610 	     */
1611 	    cleanup_conditionals(cstack, CSF_TRY, TRUE);
1612 	}
1613     }
1614 
1615     if (end != NULL)
1616 	eap->nextcmd = find_nextcmd(end);
1617 }
1618 
1619 /*
1620  * ":finally"
1621  */
1622     void
1623 ex_finally(eap)
1624     exarg_T	*eap;
1625 {
1626     int		idx;
1627     int		skip = FALSE;
1628     int		pending = CSTP_NONE;
1629     struct condstack	*cstack = eap->cstack;
1630 
1631     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1632 	eap->errmsg = (char_u *)N_("E606: :finally without :try");
1633     else
1634     {
1635 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1636 	{
1637 	    eap->errmsg = get_end_emsg(cstack);
1638 	    for (idx = cstack->cs_idx - 1; idx > 0; --idx)
1639 		if (cstack->cs_flags[idx] & CSF_TRY)
1640 		    break;
1641 	    /* Make this error pending, so that the commands in the following
1642 	     * finally clause can be executed.  This overrules also a pending
1643 	     * ":continue", ":break", ":return", or ":finish". */
1644 	    pending = CSTP_ERROR;
1645 	}
1646 	else
1647 	    idx = cstack->cs_idx;
1648 
1649 	if (cstack->cs_flags[idx] & CSF_FINALLY)
1650 	{
1651 	    /* Give up for a multiple ":finally" and ignore it. */
1652 	    eap->errmsg = (char_u *)N_("E607: multiple :finally");
1653 	    return;
1654 	}
1655 	rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1656 						       &cstack->cs_looplevel);
1657 
1658 	/*
1659 	 * Don't do something when the corresponding try block never got active
1660 	 * (because of an inactive surrounding conditional or after an error or
1661 	 * interrupt or throw) or for a ":finally" without ":try" or a multiple
1662 	 * ":finally".  After every other error (did_emsg or the conditional
1663 	 * errors detected above) or after an interrupt (got_int) or an
1664 	 * exception (did_throw), the finally clause must be executed.
1665 	 */
1666 	skip = !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1667 
1668 	if (!skip)
1669 	{
1670 	    /* When debugging or a breakpoint was encountered, display the
1671 	     * debug prompt (if not already done).  The user then knows that the
1672 	     * finally clause is executed. */
1673 	    if (dbg_check_skipped(eap))
1674 	    {
1675 		/* Handle a ">quit" debug command as if an interrupt had
1676 		 * occurred before the ":finally".  That is, discard the
1677 		 * original exception and replace it by an interrupt
1678 		 * exception. */
1679 		(void)do_intthrow(cstack);
1680 	    }
1681 
1682 	    /*
1683 	     * If there is a preceding catch clause and it caught the exception,
1684 	     * finish the exception now.  This happens also after errors except
1685 	     * when this is a multiple ":finally" or one not within a ":try".
1686 	     * After an error or interrupt, this also discards a pending
1687 	     * ":continue", ":break", ":finish", or ":return" from the preceding
1688 	     * try block or catch clause.
1689 	     */
1690 	    cleanup_conditionals(cstack, CSF_TRY, FALSE);
1691 
1692 	    /*
1693 	     * Make did_emsg, got_int, did_throw pending.  If set, they overrule
1694 	     * a pending ":continue", ":break", ":return", or ":finish".  Then
1695 	     * we have particularly to discard a pending return value (as done
1696 	     * by the call to cleanup_conditionals() above when did_emsg or
1697 	     * got_int is set).  The pending values are restored by the
1698 	     * ":endtry", except if there is a new error, interrupt, exception,
1699 	     * ":continue", ":break", ":return", or ":finish" in the following
1700 	     * finally clause.  A missing ":endwhile", ":endfor" or ":endif"
1701 	     * detected here is treated as if did_emsg and did_throw had
1702 	     * already been set, respectively in case that the error is not
1703 	     * converted to an exception, did_throw had already been unset.
1704 	     * We must not set did_emsg here since that would suppress the
1705 	     * error message.
1706 	     */
1707 	    if (pending == CSTP_ERROR || did_emsg || got_int || did_throw)
1708 	    {
1709 		if (cstack->cs_pending[cstack->cs_idx] == CSTP_RETURN)
1710 		{
1711 		    report_discard_pending(CSTP_RETURN,
1712 					   cstack->cs_rettv[cstack->cs_idx]);
1713 		    discard_pending_return(cstack->cs_rettv[cstack->cs_idx]);
1714 		}
1715 		if (pending == CSTP_ERROR && !did_emsg)
1716 		    pending |= (THROW_ON_ERROR) ? CSTP_THROW : 0;
1717 		else
1718 		    pending |= did_throw ? CSTP_THROW : 0;
1719 		pending |= did_emsg  ? CSTP_ERROR     : 0;
1720 		pending |= got_int   ? CSTP_INTERRUPT : 0;
1721 		cstack->cs_pending[cstack->cs_idx] = pending;
1722 
1723 		/* It's mandatory that the current exception is stored in the
1724 		 * cstack so that it can be rethrown at the ":endtry" or be
1725 		 * discarded if the finally clause is left by a ":continue",
1726 		 * ":break", ":return", ":finish", error, interrupt, or another
1727 		 * exception.  When emsg() is called for a missing ":endif" or
1728 		 * a missing ":endwhile"/":endfor" detected here, the
1729 		 * exception will be discarded. */
1730 		if (did_throw && cstack->cs_exception[cstack->cs_idx]
1731 							 != current_exception)
1732 		    EMSG(_(e_internal));
1733 	    }
1734 
1735 	    /*
1736 	     * Set CSL_HAD_FINA, so do_cmdline() will reset did_emsg,
1737 	     * got_int, and did_throw and make the finally clause active.
1738 	     * This will happen after emsg() has been called for a missing
1739 	     * ":endif" or a missing ":endwhile"/":endfor" detected here, so
1740 	     * that the following finally clause will be executed even then.
1741 	     */
1742 	    cstack->cs_lflags |= CSL_HAD_FINA;
1743 	}
1744     }
1745 }
1746 
1747 /*
1748  * ":endtry"
1749  */
1750     void
1751 ex_endtry(eap)
1752     exarg_T	*eap;
1753 {
1754     int		idx;
1755     int		skip;
1756     int		rethrow = FALSE;
1757     int		pending = CSTP_NONE;
1758     void	*rettv = NULL;
1759     struct condstack	*cstack = eap->cstack;
1760 
1761     if (cstack->cs_trylevel <= 0 || cstack->cs_idx < 0)
1762 	eap->errmsg = (char_u *)N_("E602: :endtry without :try");
1763     else
1764     {
1765 	/*
1766 	 * Don't do something after an error, interrupt or throw in the try
1767 	 * block, catch clause, or finally clause preceding this ":endtry" or
1768 	 * when an error or interrupt occurred after a ":continue", ":break",
1769 	 * ":return", or ":finish" in a try block or catch clause preceding this
1770 	 * ":endtry" or when the try block never got active (because of an
1771 	 * inactive surrounding conditional or after an error or interrupt or
1772 	 * throw) or when there is a surrounding conditional and it has been
1773 	 * made inactive by a ":continue", ":break", ":return", or ":finish" in
1774 	 * the finally clause.  The latter case need not be tested since then
1775 	 * anything pending has already been discarded. */
1776 	skip = did_emsg || got_int || did_throw ||
1777 	    !(cstack->cs_flags[cstack->cs_idx] & CSF_TRUE);
1778 
1779 	if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY))
1780 	{
1781 	    eap->errmsg = get_end_emsg(cstack);
1782 	    /* Find the matching ":try" and report what's missing. */
1783 	    idx = cstack->cs_idx;
1784 	    do
1785 		--idx;
1786 	    while (idx > 0 && !(cstack->cs_flags[idx] & CSF_TRY));
1787 	    rewind_conditionals(cstack, idx, CSF_WHILE | CSF_FOR,
1788 						       &cstack->cs_looplevel);
1789 	    skip = TRUE;
1790 
1791 	    /*
1792 	     * If an exception is being thrown, discard it to prevent it from
1793 	     * being rethrown at the end of this function.  It would be
1794 	     * discarded by the error message, anyway.  Resets did_throw.
1795 	     * This does not affect the script termination due to the error
1796 	     * since "trylevel" is decremented after emsg() has been called.
1797 	     */
1798 	    if (did_throw)
1799 		discard_current_exception();
1800 	}
1801 	else
1802 	{
1803 	    idx = cstack->cs_idx;
1804 
1805 	    /*
1806 	     * If we stopped with the exception currently being thrown at this
1807 	     * try conditional since we didn't know that it doesn't have
1808 	     * a finally clause, we need to rethrow it after closing the try
1809 	     * conditional.
1810 	     */
1811 	    if (did_throw && (cstack->cs_flags[idx] & CSF_TRUE)
1812 		    && !(cstack->cs_flags[idx] & CSF_FINALLY))
1813 		rethrow = TRUE;
1814 	}
1815 
1816 	/* If there was no finally clause, show the user when debugging or
1817 	 * a breakpoint was encountered that the end of the try conditional has
1818 	 * been reached: display the debug prompt (if not already done).  Do
1819 	 * this on normal control flow or when an exception was thrown, but not
1820 	 * on an interrupt or error not converted to an exception or when
1821 	 * a ":break", ":continue", ":return", or ":finish" is pending.  These
1822 	 * actions are carried out immediately.
1823 	 */
1824 	if ((rethrow || (!skip
1825 			&& !(cstack->cs_flags[idx] & CSF_FINALLY)
1826 			&& !cstack->cs_pending[idx]))
1827 		&& dbg_check_skipped(eap))
1828 	{
1829 	    /* Handle a ">quit" debug command as if an interrupt had occurred
1830 	     * before the ":endtry".  That is, throw an interrupt exception and
1831 	     * set "skip" and "rethrow". */
1832 	    if (got_int)
1833 	    {
1834 		skip = TRUE;
1835 		(void)do_intthrow(cstack);
1836 		/* The do_intthrow() call may have reset did_throw or
1837 		 * cstack->cs_pending[idx].*/
1838 		rethrow = FALSE;
1839 		if (did_throw && !(cstack->cs_flags[idx] & CSF_FINALLY))
1840 		    rethrow = TRUE;
1841 	    }
1842 	}
1843 
1844 	/*
1845 	 * If a ":return" is pending, we need to resume it after closing the
1846 	 * try conditional; remember the return value.  If there was a finally
1847 	 * clause making an exception pending, we need to rethrow it.  Make it
1848 	 * the exception currently being thrown.
1849 	 */
1850 	if (!skip)
1851 	{
1852 	    pending = cstack->cs_pending[idx];
1853 	    cstack->cs_pending[idx] = CSTP_NONE;
1854 	    if (pending == CSTP_RETURN)
1855 		rettv = cstack->cs_rettv[idx];
1856 	    else if (pending & CSTP_THROW)
1857 		current_exception = cstack->cs_exception[idx];
1858 	}
1859 
1860 	/*
1861 	 * Discard anything pending on an error, interrupt, or throw in the
1862 	 * finally clause.  If there was no ":finally", discard a pending
1863 	 * ":continue", ":break", ":return", or ":finish" if an error or
1864 	 * interrupt occurred afterwards, but before the ":endtry" was reached.
1865 	 * If an exception was caught by the last of the catch clauses and there
1866 	 * was no finally clause, finish the exception now.  This happens also
1867 	 * after errors except when this ":endtry" is not within a ":try".
1868 	 * Restore "emsg_silent" if it has been reset by this try conditional.
1869 	 */
1870 	(void)cleanup_conditionals(cstack, CSF_TRY | CSF_SILENT, TRUE);
1871 
1872 	--cstack->cs_idx;
1873 	--cstack->cs_trylevel;
1874 
1875 	if (!skip)
1876 	{
1877 	    report_resume_pending(pending,
1878 		    (pending == CSTP_RETURN) ? rettv :
1879 		    (pending & CSTP_THROW) ? (void *)current_exception : NULL);
1880 	    switch (pending)
1881 	    {
1882 		case CSTP_NONE:
1883 		    break;
1884 
1885 		/* Reactivate a pending ":continue", ":break", ":return",
1886 		 * ":finish" from the try block or a catch clause of this try
1887 		 * conditional.  This is skipped, if there was an error in an
1888 		 * (unskipped) conditional command or an interrupt afterwards
1889 		 * or if the finally clause is present and executed a new error,
1890 		 * interrupt, throw, ":continue", ":break", ":return", or
1891 		 * ":finish". */
1892 		case CSTP_CONTINUE:
1893 		    ex_continue(eap);
1894 		    break;
1895 		case CSTP_BREAK:
1896 		    ex_break(eap);
1897 		    break;
1898 		case CSTP_RETURN:
1899 		    do_return(eap, FALSE, FALSE, rettv);
1900 		    break;
1901 		case CSTP_FINISH:
1902 		    do_finish(eap, FALSE);
1903 		    break;
1904 
1905 		/* When the finally clause was entered due to an error,
1906 		 * interrupt or throw (as opposed to a ":continue", ":break",
1907 		 * ":return", or ":finish"), restore the pending values of
1908 		 * did_emsg, got_int, and did_throw.  This is skipped, if there
1909 		 * was a new error, interrupt, throw, ":continue", ":break",
1910 		 * ":return", or ":finish".  in the finally clause. */
1911 		default:
1912 		    if (pending & CSTP_ERROR)
1913 			did_emsg = TRUE;
1914 		    if (pending & CSTP_INTERRUPT)
1915 			got_int = TRUE;
1916 		    if (pending & CSTP_THROW)
1917 			rethrow = TRUE;
1918 		    break;
1919 	    }
1920 	}
1921 
1922 	if (rethrow)
1923 	    /* Rethrow the current exception (within this cstack). */
1924 	    do_throw(cstack);
1925     }
1926 }
1927 
1928 /*
1929  * enter_cleanup() and leave_cleanup()
1930  *
1931  * Functions to be called before/after invoking a sequence of autocommands for
1932  * cleanup for a failed command.  (Failure means here that a call to emsg()
1933  * has been made, an interrupt occurred, or there is an uncaught exception
1934  * from a previous autocommand execution of the same command.)
1935  *
1936  * Call enter_cleanup() with a pointer to a cleanup_T and pass the same
1937  * pointer to leave_cleanup().  The cleanup_T structure stores the pending
1938  * error/interrupt/exception state.
1939  */
1940 
1941 /*
1942  * This function works a bit like ex_finally() except that there was not
1943  * actually an extra try block around the part that failed and an error or
1944  * interrupt has not (yet) been converted to an exception.  This function
1945  * saves the error/interrupt/ exception state and prepares for the call to
1946  * do_cmdline() that is going to be made for the cleanup autocommand
1947  * execution.
1948  */
1949     void
1950 enter_cleanup(csp)
1951     cleanup_T	*csp;
1952 {
1953     int		pending = CSTP_NONE;
1954 
1955     /*
1956      * Postpone did_emsg, got_int, did_throw.  The pending values will be
1957      * restored by leave_cleanup() except if there was an aborting error,
1958      * interrupt, or uncaught exception after this function ends.
1959      */
1960     if (did_emsg || got_int || did_throw || need_rethrow)
1961     {
1962 	csp->pending = (did_emsg     ? CSTP_ERROR     : 0)
1963 		     | (got_int      ? CSTP_INTERRUPT : 0)
1964 		     | (did_throw    ? CSTP_THROW     : 0)
1965 		     | (need_rethrow ? CSTP_THROW     : 0);
1966 
1967 	/* If we are currently throwing an exception (did_throw), save it as
1968 	 * well.  On an error not yet converted to an exception, update
1969 	 * "force_abort" and reset "cause_abort" (as do_errthrow() would do).
1970 	 * This is needed for the do_cmdline() call that is going to be made
1971 	 * for autocommand execution.  We need not save *msg_list because
1972 	 * there is an extra instance for every call of do_cmdline(), anyway.
1973 	 */
1974 	if (did_throw || need_rethrow)
1975 	    csp->exception = current_exception;
1976 	else
1977 	{
1978 	    csp->exception = NULL;
1979 	    if (did_emsg)
1980 	    {
1981 		force_abort |= cause_abort;
1982 		cause_abort = FALSE;
1983 	    }
1984 	}
1985 	did_emsg = got_int = did_throw = need_rethrow = FALSE;
1986 
1987 	/* Report if required by the 'verbose' option or when debugging.  */
1988 	report_make_pending(pending, csp->exception);
1989     }
1990     else
1991     {
1992 	csp->pending = CSTP_NONE;
1993 	csp->exception = NULL;
1994     }
1995 }
1996 
1997 /*
1998  * See comment above enter_cleanup() for how this function is used.
1999  *
2000  * This function is a bit like ex_endtry() except that there was not actually
2001  * an extra try block around the part that failed and an error or interrupt
2002  * had not (yet) been converted to an exception when the cleanup autocommand
2003  * sequence was invoked.
2004  *
2005  * This function has to be called with the address of the cleanup_T structure
2006  * filled by enter_cleanup() as an argument; it restores the error/interrupt/
2007  * exception state saved by that function - except there was an aborting
2008  * error, an interrupt or an uncaught exception during execution of the
2009  * cleanup autocommands.  In the latter case, the saved error/interrupt/
2010  * exception state is discarded.
2011  */
2012     void
2013 leave_cleanup(csp)
2014     cleanup_T	*csp;
2015 {
2016     int		pending = csp->pending;
2017 
2018     if (pending == CSTP_NONE)	/* nothing to do */
2019 	return;
2020 
2021     /* If there was an aborting error, an interrupt, or an uncaught exception
2022      * after the corresponding call to enter_cleanup(), discard what has been
2023      * made pending by it.  Report this to the user if required by the
2024      * 'verbose' option or when debugging. */
2025     if (aborting() || need_rethrow)
2026     {
2027 	if (pending & CSTP_THROW)
2028 	    /* Cancel the pending exception (includes report). */
2029 	    discard_exception((except_T *)csp->exception, FALSE);
2030 	else
2031 	    report_discard_pending(pending, NULL);
2032 
2033 	/* If an error was about to be converted to an exception when
2034 	 * enter_cleanup() was called, free the message list. */
2035 	if (msg_list != NULL)
2036 	{
2037 	    free_msglist(*msg_list);
2038 	    *msg_list = NULL;
2039 	}
2040     }
2041 
2042     /*
2043      * If there was no new error, interrupt, or throw between the calls
2044      * to enter_cleanup() and leave_cleanup(), restore the pending
2045      * error/interrupt/exception state.
2046      */
2047     else
2048     {
2049 	/*
2050 	 * If there was an exception being thrown when enter_cleanup() was
2051 	 * called, we need to rethrow it.  Make it the exception currently
2052 	 * being thrown.
2053 	 */
2054 	if (pending & CSTP_THROW)
2055 	    current_exception = csp->exception;
2056 
2057 	/*
2058 	 * If an error was about to be converted to an exception when
2059 	 * enter_cleanup() was called, let "cause_abort" take the part of
2060 	 * "force_abort" (as done by cause_errthrow()).
2061 	 */
2062 	else if (pending & CSTP_ERROR)
2063 	{
2064 	    cause_abort = force_abort;
2065 	    force_abort = FALSE;
2066 	}
2067 
2068 	/*
2069 	 * Restore the pending values of did_emsg, got_int, and did_throw.
2070 	 */
2071 	if (pending & CSTP_ERROR)
2072 	    did_emsg = TRUE;
2073 	if (pending & CSTP_INTERRUPT)
2074 	    got_int = TRUE;
2075 	if (pending & CSTP_THROW)
2076 	    need_rethrow = TRUE;    /* did_throw will be set by do_one_cmd() */
2077 
2078 	/* Report if required by the 'verbose' option or when debugging. */
2079 	report_resume_pending(pending,
2080 		   (pending & CSTP_THROW) ? (void *)current_exception : NULL);
2081     }
2082 }
2083 
2084 
2085 /*
2086  * Make conditionals inactive and discard what's pending in finally clauses
2087  * until the conditional type searched for or a try conditional not in its
2088  * finally clause is reached.  If this is in an active catch clause, finish
2089  * the caught exception.
2090  * Return the cstack index where the search stopped.
2091  * Values used for "searched_cond" are (CSF_WHILE | CSF_FOR) or CSF_TRY or 0,
2092  * the latter meaning the innermost try conditional not in its finally clause.
2093  * "inclusive" tells whether the conditional searched for should be made
2094  * inactive itself (a try conditional not in its finally claused possibly find
2095  * before is always made inactive).  If "inclusive" is TRUE and
2096  * "searched_cond" is CSF_TRY|CSF_SILENT, the saved former value of
2097  * "emsg_silent", if reset when the try conditional finally reached was
2098  * entered, is restored (unsed by ex_endtry()).  This is normally done only
2099  * when such a try conditional is left.
2100  */
2101     int
2102 cleanup_conditionals(cstack, searched_cond, inclusive)
2103     struct condstack   *cstack;
2104     int		searched_cond;
2105     int		inclusive;
2106 {
2107     int		idx;
2108     int		stop = FALSE;
2109 
2110     for (idx = cstack->cs_idx; idx >= 0; --idx)
2111     {
2112 	if (cstack->cs_flags[idx] & CSF_TRY)
2113 	{
2114 	    /*
2115 	     * Discard anything pending in a finally clause and continue the
2116 	     * search.  There may also be a pending ":continue", ":break",
2117 	     * ":return", or ":finish" before the finally clause.  We must not
2118 	     * discard it, unless an error or interrupt occurred afterwards.
2119 	     */
2120 	    if (did_emsg || got_int || (cstack->cs_flags[idx] & CSF_FINALLY))
2121 	    {
2122 		switch (cstack->cs_pending[idx])
2123 		{
2124 		    case CSTP_NONE:
2125 			break;
2126 
2127 		    case CSTP_CONTINUE:
2128 		    case CSTP_BREAK:
2129 		    case CSTP_FINISH:
2130 			report_discard_pending(cstack->cs_pending[idx], NULL);
2131 			cstack->cs_pending[idx] = CSTP_NONE;
2132 			break;
2133 
2134 		    case CSTP_RETURN:
2135 			report_discard_pending(CSTP_RETURN,
2136 						      cstack->cs_rettv[idx]);
2137 			discard_pending_return(cstack->cs_rettv[idx]);
2138 			cstack->cs_pending[idx] = CSTP_NONE;
2139 			break;
2140 
2141 		    default:
2142 			if (cstack->cs_flags[idx] & CSF_FINALLY)
2143 			{
2144 			    if (cstack->cs_pending[idx] & CSTP_THROW)
2145 			    {
2146 				/* Cancel the pending exception.  This is in the
2147 				 * finally clause, so that the stack of the
2148 				 * caught exceptions is not involved. */
2149 				discard_exception((except_T *)
2150 					cstack->cs_exception[idx],
2151 					FALSE);
2152 			    }
2153 			    else
2154 				report_discard_pending(cstack->cs_pending[idx],
2155 					NULL);
2156 			    cstack->cs_pending[idx] = CSTP_NONE;
2157 			}
2158 			break;
2159 		}
2160 	    }
2161 
2162 	    /*
2163 	     * Stop at a try conditional not in its finally clause.  If this try
2164 	     * conditional is in an active catch clause, finish the caught
2165 	     * exception.
2166 	     */
2167 	    if (!(cstack->cs_flags[idx] & CSF_FINALLY))
2168 	    {
2169 		if ((cstack->cs_flags[idx] & CSF_ACTIVE)
2170 			&& (cstack->cs_flags[idx] & CSF_CAUGHT))
2171 		    finish_exception((except_T *)cstack->cs_exception[idx]);
2172 		/* Stop at this try conditional - except the try block never
2173 		 * got active (because of an inactive surrounding conditional
2174 		 * or when the ":try" appeared after an error or interrupt or
2175 		 * throw). */
2176 		if (cstack->cs_flags[idx] & CSF_TRUE)
2177 		{
2178 		    if (searched_cond == 0 && !inclusive)
2179 			break;
2180 		    stop = TRUE;
2181 		}
2182 	    }
2183 	}
2184 
2185 	/* Stop on the searched conditional type (even when the surrounding
2186 	 * conditional is not active or something has been made pending).
2187 	 * If "inclusive" is TRUE and "searched_cond" is CSF_TRY|CSF_SILENT,
2188 	 * check first whether "emsg_silent" needs to be restored. */
2189 	if (cstack->cs_flags[idx] & searched_cond)
2190 	{
2191 	    if (!inclusive)
2192 		break;
2193 	    stop = TRUE;
2194 	}
2195 	cstack->cs_flags[idx] &= ~CSF_ACTIVE;
2196 	if (stop && searched_cond != (CSF_TRY | CSF_SILENT))
2197 	    break;
2198 
2199 	/*
2200 	 * When leaving a try conditional that reset "emsg_silent" on its
2201 	 * entry after saving the original value, restore that value here and
2202 	 * free the memory used to store it.
2203 	 */
2204 	if ((cstack->cs_flags[idx] & CSF_TRY)
2205 		&& (cstack->cs_flags[idx] & CSF_SILENT))
2206 	{
2207 	    eslist_T	*elem;
2208 
2209 	    elem = cstack->cs_emsg_silent_list;
2210 	    cstack->cs_emsg_silent_list = elem->next;
2211 	    emsg_silent = elem->saved_emsg_silent;
2212 	    vim_free(elem);
2213 	    cstack->cs_flags[idx] &= ~CSF_SILENT;
2214 	}
2215 	if (stop)
2216 	    break;
2217     }
2218     return idx;
2219 }
2220 
2221 /*
2222  * Return an appropriate error message for a missing endwhile/endfor/endif.
2223  */
2224    static char_u *
2225 get_end_emsg(cstack)
2226     struct condstack	*cstack;
2227 {
2228     if (cstack->cs_flags[cstack->cs_idx] & CSF_WHILE)
2229 	return e_endwhile;
2230     if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2231 	return e_endfor;
2232     return e_endif;
2233 }
2234 
2235 
2236 /*
2237  * Rewind conditionals until index "idx" is reached.  "cond_type" and
2238  * "cond_level" specify a conditional type and the address of a level variable
2239  * which is to be decremented with each skipped conditional of the specified
2240  * type.
2241  * Also free "for info" structures where needed.
2242  */
2243     void
2244 rewind_conditionals(cstack, idx, cond_type, cond_level)
2245     struct condstack   *cstack;
2246     int		idx;
2247     int		cond_type;
2248     int		*cond_level;
2249 {
2250     while (cstack->cs_idx > idx)
2251     {
2252 	if (cstack->cs_flags[cstack->cs_idx] & cond_type)
2253 	    --*cond_level;
2254 	if (cstack->cs_flags[cstack->cs_idx] & CSF_FOR)
2255 	    free_for_info(cstack->cs_forinfo[cstack->cs_idx]);
2256 	--cstack->cs_idx;
2257     }
2258 }
2259 
2260 /*
2261  * ":endfunction" when not after a ":function"
2262  */
2263     void
2264 ex_endfunction(eap)
2265     exarg_T	*eap UNUSED;
2266 {
2267     EMSG(_("E193: :endfunction not inside a function"));
2268 }
2269 
2270 /*
2271  * Return TRUE if the string "p" looks like a ":while" or ":for" command.
2272  */
2273     int
2274 has_loop_cmd(p)
2275     char_u	*p;
2276 {
2277     int		len;
2278 
2279     /* skip modifiers, white space and ':' */
2280     for (;;)
2281     {
2282 	while (*p == ' ' || *p == '\t' || *p == ':')
2283 	    ++p;
2284 	len = modifier_len(p);
2285 	if (len == 0)
2286 	    break;
2287 	p += len;
2288     }
2289     if ((p[0] == 'w' && p[1] == 'h')
2290 	    || (p[0] == 'f' && p[1] == 'o' && p[2] == 'r'))
2291 	return TRUE;
2292     return FALSE;
2293 }
2294 
2295 #endif /* FEAT_EVAL */
2296