===================================================================
RCS file: /cvs/mandoc/man_validate.c,v
retrieving revision 1.25
retrieving revision 1.153
diff -u -p -r1.25 -r1.153
--- mandoc/man_validate.c	2009/10/18 11:36:37	1.25
+++ mandoc/man_validate.c	2020/04/18 20:40:10	1.153
@@ -1,19 +1,24 @@
-/*	$Id: man_validate.c,v 1.25 2009/10/18 11:36:37 kristaps Exp $ */
+/* $Id: man_validate.c,v 1.153 2020/04/18 20:40:10 schwarze Exp $ */
 /*
- * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
+ * Copyright (c) 2010, 2012-2020 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2008, 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
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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.
+ *
+ * Validation module for man(7) syntax trees used by mandoc(1).
  */
+#include "config.h"
+
 #include <sys/types.h>
 
 #include <assert.h>
@@ -21,261 +26,628 @@
 #include <errno.h>
 #include <limits.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <time.h>
 
-#include "libman.h"
+#include "mandoc_aux.h"
+#include "mandoc.h"
+#include "roff.h"
+#include "man.h"
 #include "libmandoc.h"
+#include "roff_int.h"
+#include "libman.h"
+#include "tag.h"
 
-#define	CHKARGS	  struct man *m, const struct man_node *n
+#define	CHKARGS	  struct roff_man *man, struct roff_node *n
 
-typedef	int	(*v_check)(CHKARGS);
+typedef	void	(*v_check)(CHKARGS);
 
-struct	man_valid {
-	v_check	 *pres;
-	v_check	 *posts;
-};
+static	void	  check_abort(CHKARGS) __attribute__((__noreturn__));
+static	void	  check_par(CHKARGS);
+static	void	  check_part(CHKARGS);
+static	void	  check_root(CHKARGS);
+static	void	  check_tag(struct roff_node *, struct roff_node *);
+static	void	  check_text(CHKARGS);
 
-static	int	  check_bline(CHKARGS);
-static	int	  check_eq0(CHKARGS);
-static	int	  check_le1(CHKARGS);
-static	int	  check_ge2(CHKARGS);
-static	int	  check_le5(CHKARGS);
-static	int	  check_par(CHKARGS);
-static	int	  check_part(CHKARGS);
-static	int	  check_root(CHKARGS);
-static	int	  check_sec(CHKARGS);
-static	int	  check_text(CHKARGS);
+static	void	  post_AT(CHKARGS);
+static	void	  post_EE(CHKARGS);
+static	void	  post_EX(CHKARGS);
+static	void	  post_IP(CHKARGS);
+static	void	  post_OP(CHKARGS);
+static	void	  post_SH(CHKARGS);
+static	void	  post_TH(CHKARGS);
+static	void	  post_TP(CHKARGS);
+static	void	  post_UC(CHKARGS);
+static	void	  post_UR(CHKARGS);
+static	void	  post_in(CHKARGS);
 
-static	v_check	  posts_eq0[] = { check_eq0, NULL };
-static	v_check	  posts_ge2_le5[] = { check_ge2, check_le5, NULL };
-static	v_check	  posts_par[] = { check_par, NULL };
-static	v_check	  posts_part[] = { check_part, NULL };
-static	v_check	  posts_sec[] = { check_sec, NULL };
-static	v_check	  posts_sp[] = { check_le1, NULL };
-static	v_check	  pres_bline[] = { check_bline, NULL };
-
-static	const struct man_valid man_valids[MAN_MAX] = {
-	{ pres_bline, posts_eq0 }, /* br */
-	{ pres_bline, posts_ge2_le5 }, /* TH */
-	{ pres_bline, posts_sec }, /* SH */
-	{ pres_bline, posts_sec }, /* SS */
-	{ pres_bline, posts_par }, /* TP */
-	{ pres_bline, posts_par }, /* LP */
-	{ pres_bline, posts_par }, /* PP */
-	{ pres_bline, posts_par }, /* P */
-	{ pres_bline, posts_par }, /* IP */
-	{ pres_bline, posts_par }, /* HP */
-	{ NULL, NULL }, /* SM */
-	{ NULL, NULL }, /* SB */
-	{ NULL, NULL }, /* BI */
-	{ NULL, NULL }, /* IB */
-	{ NULL, NULL }, /* BR */
-	{ NULL, NULL }, /* RB */
-	{ NULL, NULL }, /* R */
-	{ NULL, NULL }, /* B */
-	{ NULL, NULL }, /* I */
-	{ NULL, NULL }, /* IR */
-	{ NULL, NULL }, /* RI */
-	{ pres_bline, posts_eq0 }, /* na */
-	{ NULL, NULL }, /* i */
-	{ pres_bline, posts_sp }, /* sp */
-	{ pres_bline, posts_eq0 }, /* nf */
-	{ pres_bline, posts_eq0 }, /* fi */
-	{ NULL, NULL }, /* r */
-	{ NULL, NULL }, /* RE */
-	{ NULL, posts_part }, /* RS */
-	{ NULL, NULL }, /* DT */
-	{ NULL, NULL }, /* UC */
+static	const v_check man_valids[MAN_MAX - MAN_TH] = {
+	post_TH,    /* TH */
+	post_SH,    /* SH */
+	post_SH,    /* SS */
+	post_TP,    /* TP */
+	post_TP,    /* TQ */
+	check_abort,/* LP */
+	check_par,  /* PP */
+	check_abort,/* P */
+	post_IP,    /* IP */
+	NULL,       /* HP */
+	NULL,       /* SM */
+	NULL,       /* SB */
+	NULL,       /* BI */
+	NULL,       /* IB */
+	NULL,       /* BR */
+	NULL,       /* RB */
+	NULL,       /* R */
+	NULL,       /* B */
+	NULL,       /* I */
+	NULL,       /* IR */
+	NULL,       /* RI */
+	NULL,       /* RE */
+	check_part, /* RS */
+	NULL,       /* DT */
+	post_UC,    /* UC */
+	NULL,       /* PD */
+	post_AT,    /* AT */
+	post_in,    /* in */
+	NULL,       /* SY */
+	NULL,       /* YS */
+	post_OP,    /* OP */
+	post_EX,    /* EX */
+	post_EE,    /* EE */
+	post_UR,    /* UR */
+	NULL,       /* UE */
+	post_UR,    /* MT */
+	NULL,       /* ME */
 };
 
 
-int
-man_valid_pre(struct man *m, const struct man_node *n)
+/* Validate the subtree rooted at man->last. */
+void
+man_validate(struct roff_man *man)
 {
-	v_check		*cp;
+	struct roff_node *n;
+	const v_check	 *cp;
 
-	if (MAN_TEXT == n->type)
-		return(1);
-	if (MAN_ROOT == n->type)
-		return(1);
+	/*
+	 * Translate obsolete macros such that later code
+	 * does not need to look for them.
+	 */
 
-	if (NULL == (cp = man_valids[n->tok].pres))
-		return(1);
-	for ( ; *cp; cp++)
-		if ( ! (*cp)(m, n)) 
-			return(0);
-	return(1);
-}
+	n = man->last;
+	switch (n->tok) {
+	case MAN_LP:
+	case MAN_P:
+		n->tok = MAN_PP;
+		break;
+	default:
+		break;
+	}
 
+	/*
+	 * Iterate over all children, recursing into each one
+	 * in turn, depth-first.
+	 */
 
-int
-man_valid_post(struct man *m)
-{
-	v_check		*cp;
+	man->last = man->last->child;
+	while (man->last != NULL) {
+		man_validate(man);
+		if (man->last == n)
+			man->last = man->last->child;
+		else
+			man->last = man->last->next;
+	}
 
-	if (MAN_VALID & m->last->flags)
-		return(1);
-	m->last->flags |= MAN_VALID;
+	/* Finally validate the macro itself. */
 
-	switch (m->last->type) {
-	case (MAN_TEXT): 
-		return(check_text(m, m->last));
-	case (MAN_ROOT):
-		return(check_root(m, m->last));
+	man->last = n;
+	man->next = ROFF_NEXT_SIBLING;
+	switch (n->type) {
+	case ROFFT_TEXT:
+		check_text(man, n);
+		break;
+	case ROFFT_ROOT:
+		check_root(man, n);
+		break;
+	case ROFFT_COMMENT:
+	case ROFFT_EQN:
+	case ROFFT_TBL:
+		break;
 	default:
+		if (n->tok < ROFF_MAX) {
+			roff_validate(man);
+			break;
+		}
+		assert(n->tok >= MAN_TH && n->tok < MAN_MAX);
+		cp = man_valids + (n->tok - MAN_TH);
+		if (*cp)
+			(*cp)(man, n);
+		if (man->last == n)
+			n->flags |= NODE_VALID;
 		break;
 	}
-
-	if (NULL == (cp = man_valids[m->last->tok].posts))
-		return(1);
-	for ( ; *cp; cp++)
-		if ( ! (*cp)(m, m->last))
-			return(0);
-
-	return(1);
 }
 
-
-static int
-check_root(CHKARGS) 
+static void
+check_root(CHKARGS)
 {
+	assert((man->flags & (MAN_BLINE | MAN_ELINE)) == 0);
 
-	if (MAN_BLINE & m->flags)
-		return(man_nwarn(m, n, WEXITSCOPE));
-	if (MAN_ELINE & m->flags)
-		return(man_nwarn(m, n, WEXITSCOPE));
+	if (n->last == NULL || n->last->type == ROFFT_COMMENT)
+		mandoc_msg(MANDOCERR_DOC_EMPTY, n->line, n->pos, NULL);
+	else
+		man->meta.hasbody = 1;
 
-	m->flags &= ~MAN_BLINE;
-	m->flags &= ~MAN_ELINE;
+	if (NULL == man->meta.title) {
+		mandoc_msg(MANDOCERR_TH_NOTITLE, n->line, n->pos, NULL);
 
-	if (NULL == m->first->child)
-		return(man_nerr(m, n, WNODATA));
-	if (NULL == m->meta.title)
-		return(man_nerr(m, n, WNOTITLE));
+		/*
+		 * If a title hasn't been set, do so now (by
+		 * implication, date and section also aren't set).
+		 */
 
-	return(1);
+		man->meta.title = mandoc_strdup("");
+		man->meta.msec = mandoc_strdup("");
+		man->meta.date = mandoc_normdate(NULL, NULL);
+	}
+
+	if (man->meta.os_e &&
+	    (man->meta.rcsids & (1 << man->meta.os_e)) == 0)
+		mandoc_msg(MANDOCERR_RCS_MISSING, 0, 0,
+		    man->meta.os_e == MANDOC_OS_OPENBSD ?
+		    "(OpenBSD)" : "(NetBSD)");
 }
 
+static void
+check_abort(CHKARGS)
+{
+	abort();
+}
 
-static int
-check_text(CHKARGS) 
+/*
+ * Skip leading whitespace, dashes, backslashes, and font escapes,
+ * then create a tag if the first following byte is a letter.
+ * Priority is high unless whitespace is present.
+ */
+static void
+check_tag(struct roff_node *n, struct roff_node *nt)
 {
-	const char	*p;
-	int		 pos, c;
+	const char	*cp, *arg;
+	int		 prio, sz;
 
-	assert(n->string);
+	if (nt == NULL || nt->type != ROFFT_TEXT)
+		return;
 
-	for (p = n->string, pos = n->pos + 1; *p; p++, pos++) {
-		if ('\\' == *p) {
-			c = mandoc_special(p);
-			if (c) {
-				p += c - 1;
-				pos += c - 1;
-				continue;
+	cp = nt->string;
+	prio = TAG_STRONG;
+	for (;;) {
+		switch (*cp) {
+		case ' ':
+		case '\t':
+			prio = TAG_WEAK;
+			/* FALLTHROUGH */
+		case '-':
+			cp++;
+			break;
+		case '\\':
+			cp++;
+			switch (mandoc_escape(&cp, &arg, &sz)) {
+			case ESCAPE_FONT:
+			case ESCAPE_FONTBOLD:
+			case ESCAPE_FONTITALIC:
+			case ESCAPE_FONTBI:
+			case ESCAPE_FONTROMAN:
+			case ESCAPE_FONTCW:
+			case ESCAPE_FONTPREV:
+			case ESCAPE_IGNORE:
+				break;
+			case ESCAPE_SPECIAL:
+				if (sz != 1)
+					return;
+				switch (*arg) {
+				case '-':
+				case 'e':
+					break;
+				default:
+					return;
+				}
+				break;
+			default:
+				return;
 			}
-			if ( ! (MAN_IGN_ESCAPE & m->pflags))
-				return(man_perr(m, n->line, pos, WESCAPE));
-			if ( ! man_pwarn(m, n->line, pos, WESCAPE))
-				return(0);
-			continue;
+			break;
+		default:
+			if (isalpha((unsigned char)*cp))
+				tag_put(cp, prio, n);
+			return;
 		}
+	}
+}
 
-		if ('\t' == *p || isprint((u_char)*p)) 
-			continue;
+static void
+check_text(CHKARGS)
+{
+	char		*cp, *p;
 
-		if (MAN_IGN_CHARS & m->pflags)
-			return(man_pwarn(m, n->line, pos, WNPRINT));
-		return(man_perr(m, n->line, pos, WNPRINT));
-	}
+	if (n->flags & NODE_NOFILL)
+		return;
 
-	return(1);
+	cp = n->string;
+	for (p = cp; NULL != (p = strchr(p, '\t')); p++)
+		mandoc_msg(MANDOCERR_FI_TAB,
+		    n->line, n->pos + (int)(p - cp), NULL);
 }
 
+static void
+post_EE(CHKARGS)
+{
+	if ((n->flags & NODE_NOFILL) == 0)
+		mandoc_msg(MANDOCERR_FI_SKIP, n->line, n->pos, "EE");
+}
 
-#define	INEQ_DEFINE(x, ineq, name) \
-static int \
-check_##name(CHKARGS) \
-{ \
-	if (n->nchild ineq (x)) \
-		return(1); \
-	return(man_verr(m, n->line, n->pos, \
-			"expected line arguments %s %d, have %d", \
-			#ineq, (x), n->nchild)); \
+static void
+post_EX(CHKARGS)
+{
+	if (n->flags & NODE_NOFILL)
+		mandoc_msg(MANDOCERR_NF_SKIP, n->line, n->pos, "EX");
 }
 
-INEQ_DEFINE(0, ==, eq0)
-INEQ_DEFINE(1, <=, le1)
-INEQ_DEFINE(2, >=, ge2)
-INEQ_DEFINE(5, <=, le5)
+static void
+post_OP(CHKARGS)
+{
 
+	if (n->child == NULL)
+		mandoc_msg(MANDOCERR_OP_EMPTY, n->line, n->pos, "OP");
+	else if (n->child->next != NULL && n->child->next->next != NULL) {
+		n = n->child->next->next;
+		mandoc_msg(MANDOCERR_ARG_EXCESS,
+		    n->line, n->pos, "OP ... %s", n->string);
+	}
+}
 
-static int
-check_sec(CHKARGS)
+static void
+post_SH(CHKARGS)
 {
+	struct roff_node	*nc;
+	char			*cp, *tag;
 
-	if (MAN_BODY == n->type && 0 == n->nchild)
-		return(man_nwarn(m, n, WBODYARGS));
-	if (MAN_HEAD == n->type && 0 == n->nchild)
-		return(man_nerr(m, n, WHEADARGS));
-	return(1);
+	nc = n->child;
+	switch (n->type) {
+	case ROFFT_HEAD:
+		tag = NULL;
+		deroff(&tag, n);
+		if (tag != NULL) {
+			for (cp = tag; *cp != '\0'; cp++)
+				if (*cp == ' ')
+					*cp = '_';
+			if (nc != NULL && nc->type == ROFFT_TEXT &&
+			    strcmp(nc->string, tag) == 0)
+				tag_put(NULL, TAG_WEAK, n);
+			else
+				tag_put(tag, TAG_FALLBACK, n);
+			free(tag);
+		}
+		return;
+	case ROFFT_BODY:
+		if (nc != NULL)
+			break;
+		return;
+	default:
+		return;
+	}
+
+	if (nc->tok == MAN_PP && nc->body->child != NULL) {
+		while (nc->body->last != NULL) {
+			man->next = ROFF_NEXT_CHILD;
+			roff_node_relink(man, nc->body->last);
+			man->last = n;
+		}
+	}
+
+	if (nc->tok == MAN_PP || nc->tok == ROFF_sp || nc->tok == ROFF_br) {
+		mandoc_msg(MANDOCERR_PAR_SKIP, nc->line, nc->pos,
+		    "%s after %s", roff_name[nc->tok], roff_name[n->tok]);
+		roff_node_delete(man, nc);
+	}
+
+	/*
+	 * Trailing PP is empty, so it is deleted by check_par().
+	 * Trailing sp is significant.
+	 */
+
+	if ((nc = n->last) != NULL && nc->tok == ROFF_br) {
+		mandoc_msg(MANDOCERR_PAR_SKIP,
+		    nc->line, nc->pos, "%s at the end of %s",
+		    roff_name[nc->tok], roff_name[n->tok]);
+		roff_node_delete(man, nc);
+	}
 }
 
+static void
+post_UR(CHKARGS)
+{
+	if (n->type == ROFFT_HEAD && n->child == NULL)
+		mandoc_msg(MANDOCERR_UR_NOHEAD, n->line, n->pos,
+		    "%s", roff_name[n->tok]);
+	check_part(man, n);
+}
 
-static int
+static void
 check_part(CHKARGS)
 {
 
-	if (MAN_BODY == n->type && 0 == n->nchild)
-		return(man_nwarn(m, n, WBODYARGS));
-	return(1);
+	if (n->type == ROFFT_BODY && n->child == NULL)
+		mandoc_msg(MANDOCERR_BLK_EMPTY, n->line, n->pos,
+		    "%s", roff_name[n->tok]);
 }
 
-
-static int
+static void
 check_par(CHKARGS)
 {
 
-	if (MAN_BODY == n->type) 
-		switch (n->tok) {
-		case (MAN_IP):
-			/* FALLTHROUGH */
-		case (MAN_HP):
-			/* FALLTHROUGH */
-		case (MAN_TP):
-			/* Body-less lists are ok. */
-			break;
-		default:
-			if (n->nchild)
-				break;
-			return(man_nwarn(m, n, WBODYARGS));
+	switch (n->type) {
+	case ROFFT_BLOCK:
+		if (n->body->child == NULL)
+			roff_node_delete(man, n);
+		break;
+	case ROFFT_BODY:
+		if (n->child != NULL &&
+		    (n->child->tok == ROFF_sp || n->child->tok == ROFF_br)) {
+			mandoc_msg(MANDOCERR_PAR_SKIP,
+			    n->child->line, n->child->pos,
+			    "%s after %s", roff_name[n->child->tok],
+			    roff_name[n->tok]);
+			roff_node_delete(man, n->child);
 		}
-	if (MAN_HEAD == n->type)
-		switch (n->tok) {
-		case (MAN_PP):
-			/* FALLTHROUGH */
-		case (MAN_P):
-			/* FALLTHROUGH */
-		case (MAN_LP):
-			if (0 == n->nchild)
+		if (n->child == NULL)
+			mandoc_msg(MANDOCERR_PAR_SKIP, n->line, n->pos,
+			    "%s empty", roff_name[n->tok]);
+		break;
+	case ROFFT_HEAD:
+		if (n->child != NULL)
+			mandoc_msg(MANDOCERR_ARG_SKIP,
+			    n->line, n->pos, "%s %s%s",
+			    roff_name[n->tok], n->child->string,
+			    n->child->next != NULL ? " ..." : "");
+		break;
+	default:
+		break;
+	}
+}
+
+static void
+post_IP(CHKARGS)
+{
+	switch (n->type) {
+	case ROFFT_BLOCK:
+		if (n->head->child == NULL && n->body->child == NULL)
+			roff_node_delete(man, n);
+		break;
+	case ROFFT_HEAD:
+		check_tag(n, n->child);
+		break;
+	case ROFFT_BODY:
+		if (n->parent->head->child == NULL && n->child == NULL)
+			mandoc_msg(MANDOCERR_PAR_SKIP, n->line, n->pos,
+			    "%s empty", roff_name[n->tok]);
+		break;
+	default:
+		break;
+	}
+}
+
+/*
+ * The first next-line element in the head is the tag.
+ * If that's a font macro, use its first child instead.
+ */
+static void
+post_TP(CHKARGS)
+{
+	struct roff_node *nt;
+
+	if (n->type != ROFFT_HEAD || (nt = n->child) == NULL)
+		return;
+
+	while ((nt->flags & NODE_LINE) == 0)
+		if ((nt = nt->next) == NULL)
+			return;
+
+	switch (nt->tok) {
+	case MAN_B:
+	case MAN_BI:
+	case MAN_BR:
+	case MAN_I:
+	case MAN_IB:
+	case MAN_IR:
+		nt = nt->child;
+		break;
+	default:
+		break;
+	}
+	check_tag(n, nt);
+}
+
+static void
+post_TH(CHKARGS)
+{
+	struct roff_node *nb;
+	const char	*p;
+
+	free(man->meta.title);
+	free(man->meta.vol);
+	free(man->meta.os);
+	free(man->meta.msec);
+	free(man->meta.date);
+
+	man->meta.title = man->meta.vol = man->meta.date =
+	    man->meta.msec = man->meta.os = NULL;
+
+	nb = n;
+
+	/* ->TITLE<- MSEC DATE OS VOL */
+
+	n = n->child;
+	if (n != NULL && n->string != NULL) {
+		for (p = n->string; *p != '\0'; p++) {
+			/* Only warn about this once... */
+			if (isalpha((unsigned char)*p) &&
+			    ! isupper((unsigned char)*p)) {
+				mandoc_msg(MANDOCERR_TITLE_CASE, n->line,
+				    n->pos + (int)(p - n->string),
+				    "TH %s", n->string);
 				break;
-			return(man_nwarn(m, n, WNHEADARGS));
-		default:
-			if (n->nchild)
-				break;
-			return(man_nwarn(m, n, WHEADARGS));
+			}
 		}
+		man->meta.title = mandoc_strdup(n->string);
+	} else {
+		man->meta.title = mandoc_strdup("");
+		mandoc_msg(MANDOCERR_TH_NOTITLE, nb->line, nb->pos, "TH");
+	}
 
-	return(1);
+	/* TITLE ->MSEC<- DATE OS VOL */
+
+	if (n != NULL)
+		n = n->next;
+	if (n != NULL && n->string != NULL)
+		man->meta.msec = mandoc_strdup(n->string);
+	else {
+		man->meta.msec = mandoc_strdup("");
+		mandoc_msg(MANDOCERR_MSEC_MISSING,
+		    nb->line, nb->pos, "TH %s", man->meta.title);
+	}
+
+	/* TITLE MSEC ->DATE<- OS VOL */
+
+	if (n != NULL)
+		n = n->next;
+	if (man->quick && n != NULL)
+		man->meta.date = mandoc_strdup("");
+	else
+		man->meta.date = mandoc_normdate(n, nb);
+
+	/* TITLE MSEC DATE ->OS<- VOL */
+
+	if (n && (n = n->next))
+		man->meta.os = mandoc_strdup(n->string);
+	else if (man->os_s != NULL)
+		man->meta.os = mandoc_strdup(man->os_s);
+	if (man->meta.os_e == MANDOC_OS_OTHER && man->meta.os != NULL) {
+		if (strstr(man->meta.os, "OpenBSD") != NULL)
+			man->meta.os_e = MANDOC_OS_OPENBSD;
+		else if (strstr(man->meta.os, "NetBSD") != NULL)
+			man->meta.os_e = MANDOC_OS_NETBSD;
+	}
+
+	/* TITLE MSEC DATE OS ->VOL<- */
+	/* If missing, use the default VOL name for MSEC. */
+
+	if (n && (n = n->next))
+		man->meta.vol = mandoc_strdup(n->string);
+	else if ('\0' != man->meta.msec[0] &&
+	    (NULL != (p = mandoc_a2msec(man->meta.msec))))
+		man->meta.vol = mandoc_strdup(p);
+
+	if (n != NULL && (n = n->next) != NULL)
+		mandoc_msg(MANDOCERR_ARG_EXCESS,
+		    n->line, n->pos, "TH ... %s", n->string);
+
+	/*
+	 * Remove the `TH' node after we've processed it for our
+	 * meta-data.
+	 */
+	roff_node_delete(man, man->last);
 }
 
+static void
+post_UC(CHKARGS)
+{
+	static const char * const bsd_versions[] = {
+	    "3rd Berkeley Distribution",
+	    "4th Berkeley Distribution",
+	    "4.2 Berkeley Distribution",
+	    "4.3 Berkeley Distribution",
+	    "4.4 Berkeley Distribution",
+	};
 
-static int
-check_bline(CHKARGS)
+	const char	*p, *s;
+
+	n = n->child;
+
+	if (n == NULL || n->type != ROFFT_TEXT)
+		p = bsd_versions[0];
+	else {
+		s = n->string;
+		if (0 == strcmp(s, "3"))
+			p = bsd_versions[0];
+		else if (0 == strcmp(s, "4"))
+			p = bsd_versions[1];
+		else if (0 == strcmp(s, "5"))
+			p = bsd_versions[2];
+		else if (0 == strcmp(s, "6"))
+			p = bsd_versions[3];
+		else if (0 == strcmp(s, "7"))
+			p = bsd_versions[4];
+		else
+			p = bsd_versions[0];
+	}
+
+	free(man->meta.os);
+	man->meta.os = mandoc_strdup(p);
+}
+
+static void
+post_AT(CHKARGS)
 {
+	static const char * const unix_versions[] = {
+	    "7th Edition",
+	    "System III",
+	    "System V",
+	    "System V Release 2",
+	};
 
-	assert( ! (MAN_ELINE & m->flags));
-	if (MAN_BLINE & m->flags)
-		return(man_nerr(m, n, WLNSCOPE));
-	return(1);
+	struct roff_node *nn;
+	const char	*p, *s;
+
+	n = n->child;
+
+	if (n == NULL || n->type != ROFFT_TEXT)
+		p = unix_versions[0];
+	else {
+		s = n->string;
+		if (0 == strcmp(s, "3"))
+			p = unix_versions[0];
+		else if (0 == strcmp(s, "4"))
+			p = unix_versions[1];
+		else if (0 == strcmp(s, "5")) {
+			nn = n->next;
+			if (nn != NULL &&
+			    nn->type == ROFFT_TEXT &&
+			    nn->string[0] != '\0')
+				p = unix_versions[3];
+			else
+				p = unix_versions[2];
+		} else
+			p = unix_versions[0];
+	}
+
+	free(man->meta.os);
+	man->meta.os = mandoc_strdup(p);
 }
 
+static void
+post_in(CHKARGS)
+{
+	char	*s;
+
+	if (n->parent->tok != MAN_TP ||
+	    n->parent->type != ROFFT_HEAD ||
+	    n->child == NULL ||
+	    *n->child->string == '+' ||
+	    *n->child->string == '-')
+		return;
+	mandoc_asprintf(&s, "+%s", n->child->string);
+	free(n->child->string);
+	n->child->string = s;
+}