--- /dev/null	Sat Jul 19 14:23:45 2014
+++ new/usr/src/cmd/mandoc/tbl_layout.c	Sat Jul 19 14:23:45 2014
@@ -0,0 +1,472 @@
+/*	$Id: tbl_layout.c,v 1.22 2011/09/18 14:14:15 schwarze Exp $ */
+/*
+ * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "mandoc.h"
+#include "libmandoc.h"
+#include "libroff.h"
+
+struct	tbl_phrase {
+	char		 name;
+	enum tbl_cellt	 key;
+};
+
+/*
+ * FIXME: we can make this parse a lot nicer by, when an error is
+ * encountered in a layout key, bailing to the next key (i.e. to the
+ * next whitespace then continuing).
+ */
+
+#define	KEYS_MAX	 11
+
+static	const struct tbl_phrase keys[KEYS_MAX] = {
+	{ 'c',		 TBL_CELL_CENTRE },
+	{ 'r',		 TBL_CELL_RIGHT },
+	{ 'l',		 TBL_CELL_LEFT },
+	{ 'n',		 TBL_CELL_NUMBER },
+	{ 's',		 TBL_CELL_SPAN },
+	{ 'a',		 TBL_CELL_LONG },
+	{ '^',		 TBL_CELL_DOWN },
+	{ '-',		 TBL_CELL_HORIZ },
+	{ '_',		 TBL_CELL_HORIZ },
+	{ '=',		 TBL_CELL_DHORIZ },
+	{ '|',		 TBL_CELL_VERT }
+};
+
+static	int		 mods(struct tbl_node *, struct tbl_cell *, 
+				int, const char *, int *);
+static	int		 cell(struct tbl_node *, struct tbl_row *, 
+				int, const char *, int *);
+static	void		 row(struct tbl_node *, int, const char *, int *);
+static	struct tbl_cell *cell_alloc(struct tbl_node *, 
+				struct tbl_row *, enum tbl_cellt);
+static	void		 head_adjust(const struct tbl_cell *, 
+				struct tbl_head *);
+
+static int
+mods(struct tbl_node *tbl, struct tbl_cell *cp, 
+		int ln, const char *p, int *pos)
+{
+	char		 buf[5];
+	int		 i;
+
+	/* Not all types accept modifiers. */
+
+	switch (cp->pos) {
+	case (TBL_CELL_DOWN):
+		/* FALLTHROUGH */
+	case (TBL_CELL_HORIZ):
+		/* FALLTHROUGH */
+	case (TBL_CELL_DHORIZ):
+		/* FALLTHROUGH */
+	case (TBL_CELL_VERT):
+		/* FALLTHROUGH */
+	case (TBL_CELL_DVERT):
+		return(1);
+	default:
+		break;
+	}
+
+mod:
+	/* 
+	 * XXX: since, at least for now, modifiers are non-conflicting
+	 * (are separable by value, regardless of position), we let
+	 * modifiers come in any order.  The existing tbl doesn't let
+	 * this happen.
+	 */
+	switch (p[*pos]) {
+	case ('\0'):
+		/* FALLTHROUGH */
+	case (' '):
+		/* FALLTHROUGH */
+	case ('\t'):
+		/* FALLTHROUGH */
+	case (','):
+		/* FALLTHROUGH */
+	case ('.'):
+		return(1);
+	default:
+		break;
+	}
+
+	/* Throw away parenthesised expression. */
+
+	if ('(' == p[*pos]) {
+		(*pos)++;
+		while (p[*pos] && ')' != p[*pos])
+			(*pos)++;
+		if (')' == p[*pos]) {
+			(*pos)++;
+			goto mod;
+		}
+		mandoc_msg(MANDOCERR_TBLLAYOUT, 
+				tbl->parse, ln, *pos, NULL);
+		return(0);
+	}
+
+	/* Parse numerical spacing from modifier string. */
+
+	if (isdigit((unsigned char)p[*pos])) {
+		for (i = 0; i < 4; i++) {
+			if ( ! isdigit((unsigned char)p[*pos + i]))
+				break;
+			buf[i] = p[*pos + i];
+		}
+		buf[i] = '\0';
+
+		/* No greater than 4 digits. */
+
+		if (4 == i) {
+			mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
+					ln, *pos, NULL);
+			return(0);
+		}
+
+		*pos += i;
+		cp->spacing = (size_t)atoi(buf);
+
+		goto mod;
+		/* NOTREACHED */
+	} 
+
+	/* TODO: GNU has many more extensions. */
+
+	switch (tolower((unsigned char)p[(*pos)++])) {
+	case ('z'):
+		cp->flags |= TBL_CELL_WIGN;
+		goto mod;
+	case ('u'):
+		cp->flags |= TBL_CELL_UP;
+		goto mod;
+	case ('e'):
+		cp->flags |= TBL_CELL_EQUAL;
+		goto mod;
+	case ('t'):
+		cp->flags |= TBL_CELL_TALIGN;
+		goto mod;
+	case ('d'):
+		cp->flags |= TBL_CELL_BALIGN;
+		goto mod;
+	case ('w'):  /* XXX for now, ignore minimal column width */
+		goto mod;
+	case ('f'):
+		break;
+	case ('r'):
+		/* FALLTHROUGH */
+	case ('b'):
+		/* FALLTHROUGH */
+	case ('i'):
+		(*pos)--;
+		break;
+	default:
+		mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
+				ln, *pos - 1, NULL);
+		return(0);
+	}
+
+	switch (tolower((unsigned char)p[(*pos)++])) {
+	case ('3'):
+		/* FALLTHROUGH */
+	case ('b'):
+		cp->flags |= TBL_CELL_BOLD;
+		goto mod;
+	case ('2'):
+		/* FALLTHROUGH */
+	case ('i'):
+		cp->flags |= TBL_CELL_ITALIC;
+		goto mod;
+	case ('1'):
+		/* FALLTHROUGH */
+	case ('r'):
+		goto mod;
+	default:
+		break;
+	}
+
+	mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
+			ln, *pos - 1, NULL);
+	return(0);
+}
+
+static int
+cell(struct tbl_node *tbl, struct tbl_row *rp, 
+		int ln, const char *p, int *pos)
+{
+	int		 i;
+	enum tbl_cellt	 c;
+
+	/* Parse the column position (`r', `R', `|', ...). */
+
+	for (i = 0; i < KEYS_MAX; i++)
+		if (tolower((unsigned char)p[*pos]) == keys[i].name)
+			break;
+
+	if (KEYS_MAX == i) {
+		mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse, 
+				ln, *pos, NULL);
+		return(0);
+	}
+
+	c = keys[i].key;
+
+	/*
+	 * If a span cell is found first, raise a warning and abort the
+	 * parse.  If a span cell is found and the last layout element
+	 * isn't a "normal" layout, bail.
+	 *
+	 * FIXME: recover from this somehow?
+	 */
+
+	if (TBL_CELL_SPAN == c) {
+		if (NULL == rp->first) {
+			mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
+					ln, *pos, NULL);
+			return(0);
+		} else if (rp->last)
+			switch (rp->last->pos) {
+			case (TBL_CELL_VERT):
+			case (TBL_CELL_DVERT):
+			case (TBL_CELL_HORIZ):
+			case (TBL_CELL_DHORIZ):
+				mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
+						ln, *pos, NULL);
+				return(0);
+			default:
+				break;
+			}
+	}
+
+	/*
+	 * If a vertical spanner is found, we may not be in the first
+	 * row.
+	 */
+
+	if (TBL_CELL_DOWN == c && rp == tbl->first_row) {
+		mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse, ln, *pos, NULL);
+		return(0);
+	}
+
+	(*pos)++;
+
+	/* Extra check for the double-vertical. */
+
+	if (TBL_CELL_VERT == c && '|' == p[*pos]) {
+		(*pos)++;
+		c = TBL_CELL_DVERT;
+	} 
+	
+	/* Disallow adjacent spacers. */
+
+	if (rp->last && (TBL_CELL_VERT == c || TBL_CELL_DVERT == c) &&
+			(TBL_CELL_VERT == rp->last->pos || 
+			 TBL_CELL_DVERT == rp->last->pos)) {
+		mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse, ln, *pos - 1, NULL);
+		return(0);
+	}
+
+	/* Allocate cell then parse its modifiers. */
+
+	return(mods(tbl, cell_alloc(tbl, rp, c), ln, p, pos));
+}
+
+
+static void
+row(struct tbl_node *tbl, int ln, const char *p, int *pos)
+{
+	struct tbl_row	*rp;
+
+row:	/*
+	 * EBNF describing this section:
+	 *
+	 * row		::= row_list [:space:]* [.]?[\n]
+	 * row_list	::= [:space:]* row_elem row_tail
+	 * row_tail	::= [:space:]*[,] row_list |
+	 *                  epsilon
+	 * row_elem	::= [\t\ ]*[:alpha:]+
+	 */
+
+	rp = mandoc_calloc(1, sizeof(struct tbl_row));
+	if (tbl->last_row) {
+		tbl->last_row->next = rp;
+		tbl->last_row = rp;
+	} else
+		tbl->last_row = tbl->first_row = rp;
+
+cell:
+	while (isspace((unsigned char)p[*pos]))
+		(*pos)++;
+
+	/* Safely exit layout context. */
+
+	if ('.' == p[*pos]) {
+		tbl->part = TBL_PART_DATA;
+		if (NULL == tbl->first_row) 
+			mandoc_msg(MANDOCERR_TBLNOLAYOUT, tbl->parse, 
+					ln, *pos, NULL);
+		(*pos)++;
+		return;
+	}
+
+	/* End (and possibly restart) a row. */
+
+	if (',' == p[*pos]) {
+		(*pos)++;
+		goto row;
+	} else if ('\0' == p[*pos])
+		return;
+
+	if ( ! cell(tbl, rp, ln, p, pos))
+		return;
+
+	goto cell;
+	/* NOTREACHED */
+}
+
+int
+tbl_layout(struct tbl_node *tbl, int ln, const char *p)
+{
+	int		 pos;
+
+	pos = 0;
+	row(tbl, ln, p, &pos);
+
+	/* Always succeed. */
+	return(1);
+}
+
+static struct tbl_cell *
+cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos)
+{
+	struct tbl_cell	*p, *pp;
+	struct tbl_head	*h, *hp;
+
+	p = mandoc_calloc(1, sizeof(struct tbl_cell));
+
+	if (NULL != (pp = rp->last)) {
+		rp->last->next = p;
+		rp->last = p;
+	} else
+		rp->last = rp->first = p;
+
+	p->pos = pos;
+
+	/*
+	 * This is a little bit complicated.  Here we determine the
+	 * header the corresponds to a cell.  We add headers dynamically
+	 * when need be or re-use them, otherwise.  As an example, given
+	 * the following:
+	 *
+	 * 	1  c || l 
+	 * 	2  | c | l
+	 * 	3  l l
+	 * 	3  || c | l |.
+	 *
+	 * We first add the new headers (as there are none) in (1); then
+	 * in (2) we insert the first spanner (as it doesn't match up
+	 * with the header); then we re-use the prior data headers,
+	 * skipping over the spanners; then we re-use everything and add
+	 * a last spanner.  Note that VERT headers are made into DVERT
+	 * ones.
+	 */
+
+	h = pp ? pp->head->next : tbl->first_head;
+
+	if (h) {
+		/* Re-use data header. */
+		if (TBL_HEAD_DATA == h->pos && 
+				(TBL_CELL_VERT != p->pos &&
+				 TBL_CELL_DVERT != p->pos)) {
+			p->head = h;
+			return(p);
+		}
+
+		/* Re-use spanner header. */
+		if (TBL_HEAD_DATA != h->pos && 
+				(TBL_CELL_VERT == p->pos ||
+				 TBL_CELL_DVERT == p->pos)) {
+			head_adjust(p, h);
+			p->head = h;
+			return(p);
+		}
+
+		/* Right-shift headers with a new spanner. */
+		if (TBL_HEAD_DATA == h->pos && 
+				(TBL_CELL_VERT == p->pos ||
+				 TBL_CELL_DVERT == p->pos)) {
+			hp = mandoc_calloc(1, sizeof(struct tbl_head));
+			hp->ident = tbl->opts.cols++;
+			hp->prev = h->prev;
+			if (h->prev)
+				h->prev->next = hp;
+			if (h == tbl->first_head)
+				tbl->first_head = hp;
+			h->prev = hp;
+			hp->next = h;
+			head_adjust(p, hp);
+			p->head = hp;
+			return(p);
+		}
+
+		if (NULL != (h = h->next)) {
+			head_adjust(p, h);
+			p->head = h;
+			return(p);
+		}
+
+		/* Fall through to default case... */
+	}
+
+	hp = mandoc_calloc(1, sizeof(struct tbl_head));
+	hp->ident = tbl->opts.cols++;
+
+	if (tbl->last_head) {
+		hp->prev = tbl->last_head;
+		tbl->last_head->next = hp;
+		tbl->last_head = hp;
+	} else
+		tbl->last_head = tbl->first_head = hp;
+
+	head_adjust(p, hp);
+	p->head = hp;
+	return(p);
+}
+
+static void
+head_adjust(const struct tbl_cell *cellp, struct tbl_head *head)
+{
+	if (TBL_CELL_VERT != cellp->pos &&
+			TBL_CELL_DVERT != cellp->pos) {
+		head->pos = TBL_HEAD_DATA;
+		return;
+	}
+
+	if (TBL_CELL_VERT == cellp->pos)
+		if (TBL_HEAD_DVERT != head->pos)
+			head->pos = TBL_HEAD_VERT;
+
+	if (TBL_CELL_DVERT == cellp->pos)
+		head->pos = TBL_HEAD_DVERT;
+}
+
