mdoc.c revision 1.72 
1/*	$Id: mdoc.c,v 1.72 2010/12/21 23:46:17 schwarze Exp $ */
2/*
3 * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
4 * Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18#include <sys/types.h>
19
20#include <assert.h>
21#include <stdarg.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <time.h>
26
27#include "mandoc.h"
28#include "libmdoc.h"
29#include "libmandoc.h"
30
31#include "out.h"
32#include "term.h"
33#include "tbl.h"
34
35const	char *const __mdoc_macronames[MDOC_MAX] = {
36	"Ap",		"Dd",		"Dt",		"Os",
37	"Sh",		"Ss",		"Pp",		"D1",
38	"Dl",		"Bd",		"Ed",		"Bl",
39	"El",		"It",		"Ad",		"An",
40	"Ar",		"Cd",		"Cm",		"Dv",
41	"Er",		"Ev",		"Ex",		"Fa",
42	"Fd",		"Fl",		"Fn",		"Ft",
43	"Ic",		"In",		"Li",		"Nd",
44	"Nm",		"Op",		"Ot",		"Pa",
45	"Rv",		"St",		"Va",		"Vt",
46	/* LINTED */
47	"Xr",		"%A",		"%B",		"%D",
48	/* LINTED */
49	"%I",		"%J",		"%N",		"%O",
50	/* LINTED */
51	"%P",		"%R",		"%T",		"%V",
52	"Ac",		"Ao",		"Aq",		"At",
53	"Bc",		"Bf",		"Bo",		"Bq",
54	"Bsx",		"Bx",		"Db",		"Dc",
55	"Do",		"Dq",		"Ec",		"Ef",
56	"Em",		"Eo",		"Fx",		"Ms",
57	"No",		"Ns",		"Nx",		"Ox",
58	"Pc",		"Pf",		"Po",		"Pq",
59	"Qc",		"Ql",		"Qo",		"Qq",
60	"Re",		"Rs",		"Sc",		"So",
61	"Sq",		"Sm",		"Sx",		"Sy",
62	"Tn",		"Ux",		"Xc",		"Xo",
63	"Fo",		"Fc",		"Oo",		"Oc",
64	"Bk",		"Ek",		"Bt",		"Hf",
65	"Fr",		"Ud",		"Lb",		"Lp",
66	"Lk",		"Mt",		"Brq",		"Bro",
67	/* LINTED */
68	"Brc",		"%C",		"Es",		"En",
69	/* LINTED */
70	"Dx",		"%Q",		"br",		"sp",
71	/* LINTED */
72	"%U",		"Ta",		"TS",		"TE"
73	};
74
75const	char *const __mdoc_argnames[MDOC_ARG_MAX] = {
76	"split",		"nosplit",		"ragged",
77	"unfilled",		"literal",		"file",
78	"offset",		"bullet",		"dash",
79	"hyphen",		"item",			"enum",
80	"tag",			"diag",			"hang",
81	"ohang",		"inset",		"column",
82	"width",		"compact",		"std",
83	"filled",		"words",		"emphasis",
84	"symbolic",		"nested",		"centered"
85	};
86
87const	char * const *mdoc_macronames = __mdoc_macronames;
88const	char * const *mdoc_argnames = __mdoc_argnames;
89
90static	void		  mdoc_node_free(struct mdoc_node *);
91static	void		  mdoc_node_unlink(struct mdoc *,
92				struct mdoc_node *);
93static	void		  mdoc_free1(struct mdoc *);
94static	void		  mdoc_alloc1(struct mdoc *);
95static	struct mdoc_node *node_alloc(struct mdoc *, int, int,
96				enum mdoct, enum mdoc_type);
97static	int		  node_append(struct mdoc *,
98				struct mdoc_node *);
99static	int		  mdoc_ptext(struct mdoc *, int, char *, int);
100static	int		  mdoc_pmacro(struct mdoc *, int, char *, int);
101
102
103const struct mdoc_node *
104mdoc_node(const struct mdoc *m)
105{
106
107	return(MDOC_HALT & m->flags ? NULL : m->first);
108}
109
110
111const struct mdoc_meta *
112mdoc_meta(const struct mdoc *m)
113{
114
115	return(MDOC_HALT & m->flags ? NULL : &m->meta);
116}
117
118
119/*
120 * Frees volatile resources (parse tree, meta-data, fields).
121 */
122static void
123mdoc_free1(struct mdoc *mdoc)
124{
125
126	if (mdoc->first)
127		mdoc_node_delete(mdoc, mdoc->first);
128	if (mdoc->meta.title)
129		free(mdoc->meta.title);
130	if (mdoc->meta.os)
131		free(mdoc->meta.os);
132	if (mdoc->meta.name)
133		free(mdoc->meta.name);
134	if (mdoc->meta.arch)
135		free(mdoc->meta.arch);
136	if (mdoc->meta.vol)
137		free(mdoc->meta.vol);
138	if (mdoc->meta.msec)
139		free(mdoc->meta.msec);
140}
141
142
143/*
144 * Allocate all volatile resources (parse tree, meta-data, fields).
145 */
146static void
147mdoc_alloc1(struct mdoc *mdoc)
148{
149
150	memset(&mdoc->meta, 0, sizeof(struct mdoc_meta));
151	mdoc->flags = 0;
152	mdoc->lastnamed = mdoc->lastsec = SEC_NONE;
153	mdoc->last = mandoc_calloc(1, sizeof(struct mdoc_node));
154	mdoc->first = mdoc->last;
155	mdoc->last->type = MDOC_ROOT;
156	mdoc->next = MDOC_NEXT_CHILD;
157}
158
159
160/*
161 * Free up volatile resources (see mdoc_free1()) then re-initialises the
162 * data with mdoc_alloc1().  After invocation, parse data has been reset
163 * and the parser is ready for re-invocation on a new tree; however,
164 * cross-parse non-volatile data is kept intact.
165 */
166void
167mdoc_reset(struct mdoc *mdoc)
168{
169
170	mdoc_free1(mdoc);
171	mdoc_alloc1(mdoc);
172}
173
174
175/*
176 * Completely free up all volatile and non-volatile parse resources.
177 * After invocation, the pointer is no longer usable.
178 */
179void
180mdoc_free(struct mdoc *mdoc)
181{
182
183	mdoc_free1(mdoc);
184	free(mdoc);
185}
186
187
188/*
189 * Allocate volatile and non-volatile parse resources.
190 */
191struct mdoc *
192mdoc_alloc(struct regset *regs, void *data, mandocmsg msg)
193{
194	struct mdoc	*p;
195
196	p = mandoc_calloc(1, sizeof(struct mdoc));
197
198	p->msg = msg;
199	p->data = data;
200	p->regs = regs;
201
202	mdoc_hash_init();
203	mdoc_alloc1(p);
204	return(p);
205}
206
207
208/*
209 * Climb back up the parse tree, validating open scopes.  Mostly calls
210 * through to macro_end() in macro.c.
211 */
212int
213mdoc_endparse(struct mdoc *m)
214{
215
216	if (MDOC_HALT & m->flags)
217		return(0);
218	else if (mdoc_macroend(m))
219		return(1);
220	m->flags |= MDOC_HALT;
221	return(0);
222}
223
224
225/*
226 * Main parse routine.  Parses a single line -- really just hands off to
227 * the macro (mdoc_pmacro()) or text parser (mdoc_ptext()).
228 */
229int
230mdoc_parseln(struct mdoc *m, int ln, char *buf, int offs)
231{
232	struct mdoc_node *n;
233
234	if (MDOC_HALT & m->flags)
235		return(0);
236
237	m->flags |= MDOC_NEWLINE;
238
239	n = m->last;
240
241	if (n && MDOC_TS == n->tok && MDOC_BODY == n->type &&
242	    strncmp(buf+offs, ".TE", 3)) {
243		n = n->parent;
244		if ( ! tbl_read(n->data.TS, "mdoc tbl parser",
245		    ln, buf+offs, strlen(buf+offs)))
246			mdoc_nmsg(m, n, MANDOCERR_TBL);
247		return(1);
248	}
249
250	/*
251	 * Let the roff nS register switch SYNOPSIS mode early,
252	 * such that the parser knows at all times
253	 * whether this mode is on or off.
254	 * Note that this mode is also switched by the Sh macro.
255	 */
256	if (m->regs->regs[(int)REG_nS].set) {
257		if (m->regs->regs[(int)REG_nS].v.u)
258			m->flags |= MDOC_SYNOPSIS;
259		else
260			m->flags &= ~MDOC_SYNOPSIS;
261	}
262
263	return(('.' == buf[offs] || '\'' == buf[offs]) ?
264			mdoc_pmacro(m, ln, buf, offs) :
265			mdoc_ptext(m, ln, buf, offs));
266}
267
268
269int
270mdoc_vmsg(struct mdoc *mdoc, enum mandocerr t,
271		int ln, int pos, const char *fmt, ...)
272{
273	char		 buf[256];
274	va_list		 ap;
275
276	va_start(ap, fmt);
277	vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
278	va_end(ap);
279
280	return((*mdoc->msg)(t, mdoc->data, ln, pos, buf));
281}
282
283
284int
285mdoc_macro(MACRO_PROT_ARGS)
286{
287	assert(tok < MDOC_MAX);
288
289	/* If we're in the body, deny prologue calls. */
290
291	if (MDOC_PROLOGUE & mdoc_macros[tok].flags &&
292			MDOC_PBODY & m->flags)
293		return(mdoc_pmsg(m, line, ppos, MANDOCERR_BADBODY));
294
295	/* If we're in the prologue, deny "body" macros.  */
296
297	if ( ! (MDOC_PROLOGUE & mdoc_macros[tok].flags) &&
298			! (MDOC_PBODY & m->flags)) {
299		if ( ! mdoc_pmsg(m, line, ppos, MANDOCERR_BADPROLOG))
300			return(0);
301		if (NULL == m->meta.msec)
302			m->meta.msec = mandoc_strdup("1");
303		if (NULL == m->meta.title)
304			m->meta.title = mandoc_strdup("UNKNOWN");
305		if (NULL == m->meta.vol)
306			m->meta.vol = mandoc_strdup("LOCAL");
307		if (NULL == m->meta.os)
308			m->meta.os = mandoc_strdup("LOCAL");
309		if (0 == m->meta.date)
310			m->meta.date = time(NULL);
311		m->flags |= MDOC_PBODY;
312	}
313
314	return((*mdoc_macros[tok].fp)(m, tok, line, ppos, pos, buf));
315}
316
317
318static int
319node_append(struct mdoc *mdoc, struct mdoc_node *p)
320{
321
322	assert(mdoc->last);
323	assert(mdoc->first);
324	assert(MDOC_ROOT != p->type);
325
326	switch (mdoc->next) {
327	case (MDOC_NEXT_SIBLING):
328		mdoc->last->next = p;
329		p->prev = mdoc->last;
330		p->parent = mdoc->last->parent;
331		break;
332	case (MDOC_NEXT_CHILD):
333		mdoc->last->child = p;
334		p->parent = mdoc->last;
335		break;
336	default:
337		abort();
338		/* NOTREACHED */
339	}
340
341	p->parent->nchild++;
342
343	if ( ! mdoc_valid_pre(mdoc, p))
344		return(0);
345
346	switch (p->type) {
347	case (MDOC_HEAD):
348		assert(MDOC_BLOCK == p->parent->type);
349		p->parent->head = p;
350		break;
351	case (MDOC_TAIL):
352		assert(MDOC_BLOCK == p->parent->type);
353		p->parent->tail = p;
354		break;
355	case (MDOC_BODY):
356		if (p->end)
357			break;
358		assert(MDOC_BLOCK == p->parent->type);
359		p->parent->body = p;
360		break;
361	default:
362		break;
363	}
364
365	mdoc->last = p;
366
367	switch (p->type) {
368	case (MDOC_TEXT):
369		if ( ! mdoc_valid_post(mdoc))
370			return(0);
371		break;
372	default:
373		break;
374	}
375
376	return(1);
377}
378
379
380static struct mdoc_node *
381node_alloc(struct mdoc *m, int line, int pos,
382		enum mdoct tok, enum mdoc_type type)
383{
384	struct mdoc_node *p;
385
386	p = mandoc_calloc(1, sizeof(struct mdoc_node));
387	p->sec = m->lastsec;
388	p->line = line;
389	p->pos = pos;
390	p->tok = tok;
391	p->type = type;
392
393	/* Flag analysis. */
394
395	if (MDOC_SYNOPSIS & m->flags)
396		p->flags |= MDOC_SYNPRETTY;
397	else
398		p->flags &= ~MDOC_SYNPRETTY;
399	if (MDOC_NEWLINE & m->flags)
400		p->flags |= MDOC_LINE;
401	m->flags &= ~MDOC_NEWLINE;
402
403	return(p);
404}
405
406
407int
408mdoc_tail_alloc(struct mdoc *m, int line, int pos, enum mdoct tok)
409{
410	struct mdoc_node *p;
411
412	p = node_alloc(m, line, pos, tok, MDOC_TAIL);
413	if ( ! node_append(m, p))
414		return(0);
415	m->next = MDOC_NEXT_CHILD;
416	return(1);
417}
418
419
420int
421mdoc_head_alloc(struct mdoc *m, int line, int pos, enum mdoct tok)
422{
423	struct mdoc_node *p;
424
425	assert(m->first);
426	assert(m->last);
427
428	p = node_alloc(m, line, pos, tok, MDOC_HEAD);
429	if ( ! node_append(m, p))
430		return(0);
431	m->next = MDOC_NEXT_CHILD;
432	return(1);
433}
434
435
436int
437mdoc_body_alloc(struct mdoc *m, int line, int pos, enum mdoct tok)
438{
439	struct mdoc_node *p;
440
441	p = node_alloc(m, line, pos, tok, MDOC_BODY);
442	if ( ! node_append(m, p))
443		return(0);
444	m->next = MDOC_NEXT_CHILD;
445	return(1);
446}
447
448
449int
450mdoc_endbody_alloc(struct mdoc *m, int line, int pos, enum mdoct tok,
451		struct mdoc_node *body, enum mdoc_endbody end)
452{
453	struct mdoc_node *p;
454
455	p = node_alloc(m, line, pos, tok, MDOC_BODY);
456	p->pending = body;
457	p->end = end;
458	if ( ! node_append(m, p))
459		return(0);
460	m->next = MDOC_NEXT_SIBLING;
461	return(1);
462}
463
464
465int
466mdoc_block_alloc(struct mdoc *m, int line, int pos,
467		enum mdoct tok, struct mdoc_arg *args)
468{
469	struct mdoc_node *p;
470
471	p = node_alloc(m, line, pos, tok, MDOC_BLOCK);
472	p->args = args;
473	if (p->args)
474		(args->refcnt)++;
475	if ( ! node_append(m, p))
476		return(0);
477	m->next = MDOC_NEXT_CHILD;
478	return(1);
479}
480
481
482int
483mdoc_elem_alloc(struct mdoc *m, int line, int pos,
484		enum mdoct tok, struct mdoc_arg *args)
485{
486	struct mdoc_node *p;
487
488	p = node_alloc(m, line, pos, tok, MDOC_ELEM);
489	p->args = args;
490	if (p->args)
491		(args->refcnt)++;
492	if ( ! node_append(m, p))
493		return(0);
494	m->next = MDOC_NEXT_CHILD;
495	return(1);
496}
497
498
499int
500mdoc_word_alloc(struct mdoc *m, int line, int pos, const char *p)
501{
502	struct mdoc_node *n;
503	size_t		  sv, len;
504
505	len = strlen(p);
506
507	n = node_alloc(m, line, pos, MDOC_MAX, MDOC_TEXT);
508	n->string = mandoc_malloc(len + 1);
509	sv = strlcpy(n->string, p, len + 1);
510
511	/* Prohibit truncation. */
512	assert(sv < len + 1);
513
514	if ( ! node_append(m, n))
515		return(0);
516
517	m->next = MDOC_NEXT_SIBLING;
518	return(1);
519}
520
521
522static void
523mdoc_node_free(struct mdoc_node *p)
524{
525
526	/*
527	 * XXX: if these end up being problematic in terms of memory
528	 * management and dereferencing freed blocks, then make them
529	 * into reference-counted double-pointers.
530	 */
531
532	if (MDOC_Bd == p->tok && MDOC_BLOCK == p->type)
533		if (p->data.Bd)
534			free(p->data.Bd);
535	if (MDOC_Bl == p->tok && MDOC_BLOCK == p->type)
536		if (p->data.Bl)
537			free(p->data.Bl);
538	if (MDOC_Bf == p->tok && MDOC_HEAD == p->type)
539		if (p->data.Bf)
540			free(p->data.Bf);
541	if (MDOC_TS == p->tok && MDOC_BLOCK == p->type)
542		if (p->data.TS)
543			tbl_free(p->data.TS);
544
545	if (p->string)
546		free(p->string);
547	if (p->args)
548		mdoc_argv_free(p->args);
549	free(p);
550}
551
552
553static void
554mdoc_node_unlink(struct mdoc *m, struct mdoc_node *n)
555{
556
557	/* Adjust siblings. */
558
559	if (n->prev)
560		n->prev->next = n->next;
561	if (n->next)
562		n->next->prev = n->prev;
563
564	/* Adjust parent. */
565
566	if (n->parent) {
567		n->parent->nchild--;
568		if (n->parent->child == n)
569			n->parent->child = n->prev ? n->prev : n->next;
570		if (n->parent->last == n)
571			n->parent->last = n->prev ? n->prev : NULL;
572	}
573
574	/* Adjust parse point, if applicable. */
575
576	if (m && m->last == n) {
577		if (n->prev) {
578			m->last = n->prev;
579			m->next = MDOC_NEXT_SIBLING;
580		} else {
581			m->last = n->parent;
582			m->next = MDOC_NEXT_CHILD;
583		}
584	}
585
586	if (m && m->first == n)
587		m->first = NULL;
588}
589
590
591void
592mdoc_node_delete(struct mdoc *m, struct mdoc_node *p)
593{
594
595	while (p->child) {
596		assert(p->nchild);
597		mdoc_node_delete(m, p->child);
598	}
599	assert(0 == p->nchild);
600
601	mdoc_node_unlink(m, p);
602	mdoc_node_free(p);
603}
604
605
606/*
607 * Parse free-form text, that is, a line that does not begin with the
608 * control character.
609 */
610static int
611mdoc_ptext(struct mdoc *m, int line, char *buf, int offs)
612{
613	char		 *c, *ws, *end;
614	struct mdoc_node *n;
615
616	/* Ignore bogus comments. */
617
618	if ('\\' == buf[offs] &&
619			'.' == buf[offs + 1] &&
620			'"' == buf[offs + 2])
621		return(mdoc_pmsg(m, line, offs, MANDOCERR_BADCOMMENT));
622
623	/* No text before an initial macro. */
624
625	if (SEC_NONE == m->lastnamed)
626		return(mdoc_pmsg(m, line, offs, MANDOCERR_NOTEXT));
627
628	assert(m->last);
629	n = m->last;
630
631	/*
632	 * Divert directly to list processing if we're encountering a
633	 * columnar MDOC_BLOCK with or without a prior MDOC_BLOCK entry
634	 * (a MDOC_BODY means it's already open, in which case we should
635	 * process within its context in the normal way).
636	 */
637
638	if (MDOC_Bl == n->tok && MDOC_BODY == n->type &&
639			LIST_column == n->data.Bl->type) {
640		/* `Bl' is open without any children. */
641		m->flags |= MDOC_FREECOL;
642		return(mdoc_macro(m, MDOC_It, line, offs, &offs, buf));
643	}
644
645	if (MDOC_It == n->tok && MDOC_BLOCK == n->type &&
646			NULL != n->parent &&
647			MDOC_Bl == n->parent->tok &&
648			LIST_column == n->parent->data.Bl->type) {
649		/* `Bl' has block-level `It' children. */
650		m->flags |= MDOC_FREECOL;
651		return(mdoc_macro(m, MDOC_It, line, offs, &offs, buf));
652	}
653
654	/*
655	 * Search for the beginning of unescaped trailing whitespace (ws)
656	 * and for the first character not to be output (end).
657	 */
658
659	/* FIXME: replace with strcspn(). */
660	ws = NULL;
661	for (c = end = buf + offs; *c; c++) {
662		switch (*c) {
663		case '-':
664			if (mandoc_hyph(buf + offs, c))
665				*c = ASCII_HYPH;
666			ws = NULL;
667			break;
668		case ' ':
669			if (NULL == ws)
670				ws = c;
671			continue;
672		case '\t':
673			/*
674			 * Always warn about trailing tabs,
675			 * even outside literal context,
676			 * where they should be put on the next line.
677			 */
678			if (NULL == ws)
679				ws = c;
680			/*
681			 * Strip trailing tabs in literal context only;
682			 * outside, they affect the next line.
683			 */
684			if (MDOC_LITERAL & m->flags)
685				continue;
686			break;
687		case '\\':
688			/* Skip the escaped character, too, if any. */
689			if (c[1])
690				c++;
691			/* FALLTHROUGH */
692		default:
693			ws = NULL;
694			break;
695		}
696		end = c + 1;
697	}
698	*end = '\0';
699
700	if (ws)
701		if ( ! mdoc_pmsg(m, line, (int)(ws-buf), MANDOCERR_EOLNSPACE))
702			return(0);
703
704	if ('\0' == buf[offs] && ! (MDOC_LITERAL & m->flags)) {
705		if ( ! mdoc_pmsg(m, line, (int)(c-buf), MANDOCERR_NOBLANKLN))
706			return(0);
707
708		/*
709		 * Insert a `sp' in the case of a blank line.  Technically,
710		 * blank lines aren't allowed, but enough manuals assume this
711		 * behaviour that we want to work around it.
712		 */
713		if ( ! mdoc_elem_alloc(m, line, offs, MDOC_sp, NULL))
714			return(0);
715
716		m->next = MDOC_NEXT_SIBLING;
717		return(1);
718	}
719
720	if ( ! mdoc_word_alloc(m, line, offs, buf+offs))
721		return(0);
722
723	if (MDOC_LITERAL & m->flags)
724		return(1);
725
726	/*
727	 * End-of-sentence check.  If the last character is an unescaped
728	 * EOS character, then flag the node as being the end of a
729	 * sentence.  The front-end will know how to interpret this.
730	 */
731
732	assert(buf < end);
733
734	if (mandoc_eos(buf+offs, (size_t)(end-buf-offs), 0))
735		m->last->flags |= MDOC_EOS;
736
737	return(1);
738}
739
740
741/*
742 * Parse a macro line, that is, a line beginning with the control
743 * character.
744 */
745static int
746mdoc_pmacro(struct mdoc *m, int ln, char *buf, int offs)
747{
748	enum mdoct	  tok;
749	int		  i, j, sv;
750	char		  mac[5];
751	struct mdoc_node *n;
752
753	/* Empty lines are ignored. */
754
755	offs++;
756
757	if ('\0' == buf[offs])
758		return(1);
759
760	i = offs;
761
762	/* Accept tabs/whitespace after the initial control char. */
763
764	if (' ' == buf[i] || '\t' == buf[i]) {
765		i++;
766		while (buf[i] && (' ' == buf[i] || '\t' == buf[i]))
767			i++;
768		if ('\0' == buf[i])
769			return(1);
770	}
771
772	sv = i;
773
774	/*
775	 * Copy the first word into a nil-terminated buffer.
776	 * Stop copying when a tab, space, or eoln is encountered.
777	 */
778
779	j = 0;
780	while (j < 4 && '\0' != buf[i] && ' ' != buf[i] && '\t' != buf[i])
781		mac[j++] = buf[i++];
782	mac[j] = '\0';
783
784	tok = (j > 1 || j < 4) ? mdoc_hash_find(mac) : MDOC_MAX;
785	if (MDOC_MAX == tok) {
786		mdoc_vmsg(m, MANDOCERR_MACRO, ln, sv, "%s", buf + sv - 1);
787		return(1);
788	}
789
790	/* Disregard the first trailing tab, if applicable. */
791
792	if ('\t' == buf[i])
793		i++;
794
795	/* Jump to the next non-whitespace word. */
796
797	while (buf[i] && ' ' == buf[i])
798		i++;
799
800	/*
801	 * Trailing whitespace.  Note that tabs are allowed to be passed
802	 * into the parser as "text", so we only warn about spaces here.
803	 */
804
805	if ('\0' == buf[i] && ' ' == buf[i - 1])
806		if ( ! mdoc_pmsg(m, ln, i - 1, MANDOCERR_EOLNSPACE))
807			goto err;
808
809	/*
810	 * If an initial macro or a list invocation, divert directly
811	 * into macro processing.
812	 */
813
814	if (NULL == m->last || MDOC_It == tok || MDOC_El == tok) {
815		if ( ! mdoc_macro(m, tok, ln, sv, &i, buf))
816			goto err;
817		return(1);
818	}
819
820	n = m->last;
821	assert(m->last);
822
823	/*
824	 * If the first macro of a `Bl -column', open an `It' block
825	 * context around the parsed macro.
826	 */
827
828	if (MDOC_Bl == n->tok && MDOC_BODY == n->type &&
829			LIST_column == n->data.Bl->type) {
830		m->flags |= MDOC_FREECOL;
831		if ( ! mdoc_macro(m, MDOC_It, ln, sv, &sv, buf))
832			goto err;
833		return(1);
834	}
835
836	/*
837	 * If we're following a block-level `It' within a `Bl -column'
838	 * context (perhaps opened in the above block or in ptext()),
839	 * then open an `It' block context around the parsed macro.
840	 */
841
842	if (MDOC_It == n->tok && MDOC_BLOCK == n->type &&
843			NULL != n->parent &&
844			MDOC_Bl == n->parent->tok &&
845			LIST_column == n->parent->data.Bl->type) {
846		m->flags |= MDOC_FREECOL;
847		if ( ! mdoc_macro(m, MDOC_It, ln, sv, &sv, buf))
848			goto err;
849		return(1);
850	}
851
852	/* Normal processing of a macro. */
853
854	if ( ! mdoc_macro(m, tok, ln, sv, &i, buf))
855		goto err;
856
857	return(1);
858
859err:	/* Error out. */
860
861	m->flags |= MDOC_HALT;
862	return(0);
863}
864
865
866