===================================================================
RCS file: /cvs/mandoc/mdoc_validate.c,v
retrieving revision 1.320
retrieving revision 1.335
diff -u -p -r1.320 -r1.335
--- mandoc/mdoc_validate.c	2017/04/24 23:06:18	1.320
+++ mandoc/mdoc_validate.c	2017/06/11 14:24:55	1.335
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_validate.c,v 1.320 2017/04/24 23:06:18 schwarze Exp $ */
+/*	$Id: mdoc_validate.c,v 1.335 2017/06/11 14:24:55 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -53,12 +53,13 @@ typedef	void	(*v_post)(POST_ARGS);
 
 static	int	 build_list(struct roff_man *, int);
 static	void	 check_text(struct roff_man *, int, int, char *);
+static	void	 check_bsd(struct roff_man *, int, int, char *);
 static	void	 check_argv(struct roff_man *,
 			struct roff_node *, struct mdoc_argv *);
 static	void	 check_args(struct roff_man *, struct roff_node *);
 static	int	 child_an(const struct roff_node *);
 static	size_t		macro2len(enum roff_tok);
-static	void	 rewrite_macro2len(char **);
+static	void	 rewrite_macro2len(struct roff_man *, char **);
 
 static	void	 post_an(POST_ARGS);
 static	void	 post_an_norm(POST_ARGS);
@@ -74,6 +75,7 @@ static	void	 post_bx(POST_ARGS);
 static	void	 post_defaults(POST_ARGS);
 static	void	 post_display(POST_ARGS);
 static	void	 post_dd(POST_ARGS);
+static	void	 post_delim(POST_ARGS);
 static	void	 post_dt(POST_ARGS);
 static	void	 post_en(POST_ARGS);
 static	void	 post_es(POST_ARGS);
@@ -105,6 +107,7 @@ static	void	 post_sh_authors(POST_ARGS);
 static	void	 post_sm(POST_ARGS);
 static	void	 post_st(POST_ARGS);
 static	void	 post_std(POST_ARGS);
+static	void	 post_useless(POST_ARGS);
 static	void	 post_xr(POST_ARGS);
 static	void	 post_xx(POST_ARGS);
 
@@ -122,33 +125,33 @@ static	const v_post __mdoc_valids[MDOC_MAX - MDOC_Dd] 
 	post_bl,	/* Bl */
 	NULL,		/* El */
 	post_it,	/* It */
-	NULL,		/* Ad */
+	post_delim,	/* Ad */
 	post_an,	/* An */
 	NULL,		/* Ap */
 	post_defaults,	/* Ar */
 	NULL,		/* Cd */
-	NULL,		/* Cm */
-	NULL,		/* Dv */
-	NULL,		/* Er */
-	NULL,		/* Ev */
+	post_delim,	/* Cm */
+	post_delim,	/* Dv */
+	post_delim,	/* Er */
+	post_delim,	/* Ev */
 	post_ex,	/* Ex */
 	post_fa,	/* Fa */
 	NULL,		/* Fd */
-	NULL,		/* Fl */
+	post_delim,	/* Fl */
 	post_fn,	/* Fn */
-	NULL,		/* Ft */
-	NULL,		/* Ic */
-	NULL,		/* In */
+	post_delim,	/* Ft */
+	post_delim,	/* Ic */
+	post_delim,	/* In */
 	post_defaults,	/* Li */
 	post_nd,	/* Nd */
 	post_nm,	/* Nm */
-	NULL,		/* Op */
+	post_delim,	/* Op */
 	post_obsolete,	/* Ot */
 	post_defaults,	/* Pa */
 	post_rv,	/* Rv */
 	post_st,	/* St */
-	NULL,		/* Va */
-	NULL,		/* Vt */
+	post_delim,	/* Va */
+	post_delim,	/* Vt */
 	post_xr,	/* Xr */
 	NULL,		/* %A */
 	post_hyph,	/* %B */ /* FIXME: can be used outside Rs/Re. */
@@ -162,12 +165,12 @@ static	const v_post __mdoc_valids[MDOC_MAX - MDOC_Dd] 
 	post_hyph,	/* %T */ /* FIXME: can be used outside Rs/Re. */
 	NULL,		/* %V */
 	NULL,		/* Ac */
-	NULL,		/* Ao */
-	NULL,		/* Aq */
+	post_delim,	/* Ao */
+	post_delim,	/* Aq */
 	post_at,	/* At */
 	NULL,		/* Bc */
 	post_bf,	/* Bf */
-	NULL,		/* Bo */
+	post_delim,	/* Bo */
 	NULL,		/* Bq */
 	post_xx,	/* Bsx */
 	post_bx,	/* Bx */
@@ -177,61 +180,58 @@ static	const v_post __mdoc_valids[MDOC_MAX - MDOC_Dd] 
 	NULL,		/* Dq */
 	NULL,		/* Ec */
 	NULL,		/* Ef */
-	NULL,		/* Em */
+	post_delim,	/* Em */
 	NULL,		/* Eo */
 	post_xx,	/* Fx */
-	NULL,		/* Ms */
+	post_delim,	/* Ms */
 	NULL,		/* No */
 	post_ns,	/* Ns */
 	post_xx,	/* Nx */
 	post_xx,	/* Ox */
 	NULL,		/* Pc */
 	NULL,		/* Pf */
-	NULL,		/* Po */
-	NULL,		/* Pq */
+	post_delim,	/* Po */
+	post_delim,	/* Pq */
 	NULL,		/* Qc */
-	NULL,		/* Ql */
-	NULL,		/* Qo */
-	NULL,		/* Qq */
+	post_delim,	/* Ql */
+	post_delim,	/* Qo */
+	post_delim,	/* Qq */
 	NULL,		/* Re */
 	post_rs,	/* Rs */
 	NULL,		/* Sc */
-	NULL,		/* So */
-	NULL,		/* Sq */
+	post_delim,	/* So */
+	post_delim,	/* Sq */
 	post_sm,	/* Sm */
 	post_hyph,	/* Sx */
-	NULL,		/* Sy */
-	NULL,		/* Tn */
+	post_delim,	/* Sy */
+	post_useless,	/* Tn */
 	post_xx,	/* Ux */
 	NULL,		/* Xc */
 	NULL,		/* Xo */
 	post_fo,	/* Fo */
 	NULL,		/* Fc */
-	NULL,		/* Oo */
+	post_delim,	/* Oo */
 	NULL,		/* Oc */
 	post_bk,	/* Bk */
 	NULL,		/* Ek */
 	post_eoln,	/* Bt */
-	NULL,		/* Hf */
+	post_obsolete,	/* Hf */
 	post_obsolete,	/* Fr */
 	post_eoln,	/* Ud */
 	post_lb,	/* Lb */
 	post_par,	/* Lp */
-	NULL,		/* Lk */
+	post_delim,	/* Lk */
 	post_defaults,	/* Mt */
-	NULL,		/* Brq */
-	NULL,		/* Bro */
+	post_delim,	/* Brq */
+	post_delim,	/* Bro */
 	NULL,		/* Brc */
 	NULL,		/* %C */
 	post_es,	/* Es */
 	post_en,	/* En */
 	post_xx,	/* Dx */
 	NULL,		/* %Q */
-	post_par,	/* br */
-	post_par,	/* sp */
 	NULL,		/* %U */
 	NULL,		/* Ta */
-	NULL,		/* ll */
 };
 static	const v_post *const mdoc_valids = __mdoc_valids - MDOC_Dd;
 
@@ -304,6 +304,10 @@ mdoc_node_validate(struct roff_man *mdoc)
 		if (n->sec != SEC_SYNOPSIS ||
 		    (n->parent->tok != MDOC_Cd && n->parent->tok != MDOC_Fd))
 			check_text(mdoc, n->line, n->pos, n->string);
+		if (n->parent->tok == MDOC_Sh ||
+		    n->parent->tok == MDOC_Ss ||
+		    n->parent->tok == MDOC_It)
+			check_bsd(mdoc, n->line, n->pos, n->string);
 		break;
 	case ROFFT_EQN:
 	case ROFFT_TBL:
@@ -327,6 +331,20 @@ mdoc_node_validate(struct roff_man *mdoc)
 
 		/* Call the macro's postprocessor. */
 
+		if (n->tok < ROFF_MAX) {
+			switch(n->tok) {
+			case ROFF_br:
+			case ROFF_sp:
+				post_par(mdoc);
+				break;
+			default:
+				roff_validate(mdoc);
+				break;
+			}
+			break;
+		}
+
+		assert(n->tok >= MDOC_Dd && n->tok < MDOC_MAX);
 		p = mdoc_valids + n->tok;
 		if (*p)
 			(*p)(mdoc);
@@ -372,6 +390,120 @@ check_text(struct roff_man *mdoc, int ln, int pos, cha
 }
 
 static void
+check_bsd(struct roff_man *mdoc, int ln, int pos, char *p)
+{
+	const char	*cp;
+
+	if ((cp = strstr(p, "OpenBSD")) != NULL)
+		mandoc_msg(MANDOCERR_BX, mdoc->parse,
+		    ln, pos + (cp - p), "Ox");
+	if ((cp = strstr(p, "NetBSD")) != NULL)
+		mandoc_msg(MANDOCERR_BX, mdoc->parse,
+		    ln, pos + (cp - p), "Nx");
+	if ((cp = strstr(p, "FreeBSD")) != NULL)
+		mandoc_msg(MANDOCERR_BX, mdoc->parse,
+		    ln, pos + (cp - p), "Fx");
+	if ((cp = strstr(p, "DragonFly")) != NULL)
+		mandoc_msg(MANDOCERR_BX, mdoc->parse,
+		    ln, pos + (cp - p), "Dx");
+}
+
+static void
+post_delim(POST_ARGS)
+{
+	const struct roff_node	*nch;
+	const char		*lc, *cp;
+	int			 nw;
+	enum mdelim		 delim;
+	enum roff_tok		 tok;
+
+	/*
+	 * Find candidates: at least two bytes,
+	 * the last one a closing or middle delimiter.
+	 */
+
+	tok = mdoc->last->tok;
+	nch = mdoc->last->last;
+	if (nch == NULL || nch->type != ROFFT_TEXT)
+		return;
+	lc = strchr(nch->string, '\0') - 1;
+	if (lc <= nch->string)
+		return;
+	delim = mdoc_isdelim(lc);
+	if (delim == DELIM_NONE || delim == DELIM_OPEN)
+		return;
+
+	/*
+	 * Reduce false positives by allowing various cases.
+	 */
+
+	/* Escaped delimiters. */
+	if (lc > nch->string + 1 && lc[-2] == '\\' &&
+	    (lc[-1] == '&' || lc[-1] == 'e'))
+		return;
+
+	/* Specific byte sequences. */
+	switch (*lc) {
+	case ')':
+		for (cp = lc; cp >= nch->string; cp--)
+			if (*cp == '(')
+				return;
+		break;
+	case '.':
+		if (lc > nch->string + 1 && lc[-2] == '.' && lc[-1] == '.')
+			return;
+		if (lc[-1] == '.')
+			return;
+		break;
+	case ';':
+		if (tok == MDOC_Vt)
+			return;
+		break;
+	case '?':
+		if (lc[-1] == '?')
+			return;
+		break;
+	case ']':
+		for (cp = lc; cp >= nch->string; cp--)
+			if (*cp == '[')
+				return;
+		break;
+	case '|':
+		if (lc == nch->string + 1 && lc[-1] == '|')
+			return;
+	default:
+		break;
+	}
+
+	/* Exactly two non-alphanumeric bytes. */
+	if (lc == nch->string + 1 && !isalnum((unsigned char)lc[-1]))
+		return;
+
+	/* At least three alphabetic words with a sentence ending. */
+	if (strchr("!.:?", *lc) != NULL && (tok == MDOC_Em ||
+	    tok == MDOC_Li || tok == MDOC_Po || tok == MDOC_Pq ||
+	    tok == MDOC_Sy)) {
+		nw = 0;
+		for (cp = lc - 1; cp >= nch->string; cp--) {
+			if (*cp == ' ') {
+				nw++;
+				if (cp > nch->string && cp[-1] == ',')
+					cp--;
+			} else if (isalpha((unsigned int)*cp)) {
+				if (nw > 1)
+					return;
+			} else
+				break;
+		}
+	}
+
+	mandoc_vmsg(MANDOCERR_DELIM, mdoc->parse,
+	    nch->line, nch->pos + (lc - nch->string),
+	    "%s%s %s", roff_name[tok],
+	    nch == mdoc->last->child ? "" : " ...", nch->string);
+}
+
+static void
 post_bl_norm(POST_ARGS)
 {
 	struct roff_node *n;
@@ -451,7 +583,7 @@ post_bl_norm(POST_ARGS)
 				    mdoc->parse, argv->line,
 				    argv->pos, "Bl -width %s",
 				    argv->value[0]);
-			rewrite_macro2len(argv->value);
+			rewrite_macro2len(mdoc, argv->value);
 			n->norm->Bl.width = argv->value[0];
 			break;
 		case MDOC_Offset:
@@ -466,7 +598,7 @@ post_bl_norm(POST_ARGS)
 				    mdoc->parse, argv->line,
 				    argv->pos, "Bl -offset %s",
 				    argv->value[0]);
-			rewrite_macro2len(argv->value);
+			rewrite_macro2len(mdoc, argv->value);
 			n->norm->Bl.offs = argv->value[0];
 			break;
 		default:
@@ -593,7 +725,7 @@ post_bd(POST_ARGS)
 				    mdoc->parse, argv->line,
 				    argv->pos, "Bd -offset %s",
 				    argv->value[0]);
-			rewrite_macro2len(argv->value);
+			rewrite_macro2len(mdoc, argv->value);
 			n->norm->Bd.offs = argv->value[0];
 			break;
 		case MDOC_Compact:
@@ -660,6 +792,7 @@ post_eoln(POST_ARGS)
 {
 	struct roff_node	*n;
 
+	post_useless(mdoc);
 	n = mdoc->last;
 	if (n->child != NULL)
 		mandoc_vmsg(MANDOCERR_ARG_SKIP, mdoc->parse, n->line,
@@ -745,6 +878,8 @@ post_lb(POST_ARGS)
 	struct roff_node	*n;
 	const char		*p;
 
+	post_delim(mdoc);
+
 	n = mdoc->last;
 	assert(n->child->type == ROFFT_TEXT);
 	mdoc->next = ROFF_NEXT_CHILD;
@@ -757,6 +892,9 @@ post_lb(POST_ARGS)
 		return;
 	}
 
+	mandoc_vmsg(MANDOCERR_LB_BAD, mdoc->parse, n->child->line,
+	    n->child->pos, "Lb %s", n->child->string);
+
 	roff_word_alloc(mdoc, n->line, n->pos, "library");
 	mdoc->last->flags = NODE_NOSRC;
 	roff_word_alloc(mdoc, n->line, n->pos, "\\(Lq");
@@ -855,6 +993,16 @@ post_obsolete(POST_ARGS)
 		    n->line, n->pos, roff_name[n->tok]);
 }
 
+static void
+post_useless(POST_ARGS)
+{
+	struct roff_node *n;
+
+	n = mdoc->last;
+	mandoc_msg(MANDOCERR_MACRO_USELESS, mdoc->parse,
+	    n->line, n->pos, roff_name[n->tok]);
+}
+
 /*
  * Block macros.
  */
@@ -992,6 +1140,7 @@ post_fa(POST_ARGS)
 			break;
 		}
 	}
+	post_delim(mdoc);
 }
 
 static void
@@ -1014,6 +1163,9 @@ post_nm(POST_ARGS)
 		mandoc_msg(MANDOCERR_NM_NONAME, mdoc->parse,
 		    n->line, n->pos, "Nm");
 
+	if (n->type == ROFFT_ELEM)
+		post_delim(mdoc);
+
 	if ((n->type != ROFFT_ELEM && n->type != ROFFT_HEAD) ||
 	    (n->child != NULL && n->child->type == ROFFT_TEXT) ||
 	    mdoc->meta.name == NULL)
@@ -1029,6 +1181,7 @@ static void
 post_nd(POST_ARGS)
 {
 	struct roff_node	*n;
+	size_t			 sz;
 
 	n = mdoc->last;
 
@@ -1042,6 +1195,11 @@ post_nd(POST_ARGS)
 	if (n->child == NULL)
 		mandoc_msg(MANDOCERR_ND_EMPTY, mdoc->parse,
 		    n->line, n->pos, "Nd");
+	else if (n->last->type == ROFFT_TEXT &&
+	    (sz = strlen(n->last->string)) != 0 &&
+	    n->last->string[sz - 1] == '.')
+		mandoc_msg(MANDOCERR_ND_DOT, mdoc->parse,
+		    n->last->line, n->last->pos + sz - 1, NULL);
 
 	post_hyph(mdoc);
 }
@@ -1098,17 +1256,18 @@ post_defaults(POST_ARGS)
 {
 	struct roff_node *nn;
 
+	if (mdoc->last->child != NULL) {
+		post_delim(mdoc);
+		return;
+	}
+
 	/*
 	 * The `Ar' defaults to "file ..." if no value is provided as an
 	 * argument; the `Mt' and `Pa' macros use "~"; the `Li' just
 	 * gets an empty string.
 	 */
 
-	if (mdoc->last->child != NULL)
-		return;
-
 	nn = mdoc->last;
-
 	switch (nn->tok) {
 	case MDOC_Ar:
 		mdoc->next = ROFF_NEXT_CHILD;
@@ -1172,6 +1331,8 @@ post_an(POST_ARGS)
 		if (nch == NULL)
 			mandoc_msg(MANDOCERR_MACRO_EMPTY, mdoc->parse,
 			    np->line, np->pos, "An");
+		else
+			post_delim(mdoc);
 	} else if (nch != NULL)
 		mandoc_vmsg(MANDOCERR_ARG_EXCESS, mdoc->parse,
 		    nch->line, nch->pos, "An ... %s", nch->string);
@@ -1200,6 +1361,8 @@ post_xx(POST_ARGS)
 	struct roff_node	*n;
 	const char		*os;
 
+	post_delim(mdoc);
+
 	n = mdoc->last;
 	switch (n->tok) {
 	case MDOC_Bsx:
@@ -1310,7 +1473,7 @@ post_bl_block(POST_ARGS)
 			switch (nc->tok) {
 			case MDOC_Pp:
 			case MDOC_Lp:
-			case MDOC_br:
+			case ROFF_br:
 				break;
 			default:
 				nc = NULL;
@@ -1338,8 +1501,8 @@ post_bl_block(POST_ARGS)
  * If the argument of -offset or -width is a macro,
  * replace it with the associated default width.
  */
-void
-rewrite_macro2len(char **arg)
+static void
+rewrite_macro2len(struct roff_man *mdoc, char **arg)
 {
 	size_t		  width;
 	enum roff_tok	  tok;
@@ -1348,7 +1511,7 @@ rewrite_macro2len(char **arg)
 		return;
 	else if ( ! strcmp(*arg, "Ds"))
 		width = 6;
-	else if ((tok = mdoc_hash_find(*arg)) == TOKEN_NONE)
+	else if ((tok = roffhash_find(mdoc->mdocmac, *arg, 0)) == TOKEN_NONE)
 		return;
 	else
 		width = macro2len(tok);
@@ -1426,6 +1589,8 @@ post_bl(POST_ARGS)
 	struct roff_node	*nparent, *nprev; /* of the Bl block */
 	struct roff_node	*nblock, *nbody;  /* of the Bl */
 	struct roff_node	*nchild, *nnext;  /* of the Bl body */
+	const char		*prev_Er;
+	int			 order;
 
 	nbody = mdoc->last;
 	switch (nbody->type) {
@@ -1526,6 +1691,34 @@ post_bl(POST_ARGS)
 
 		nchild = nnext;
 	}
+
+	if (mdoc->meta.os_e != MDOC_OS_NETBSD)
+		return;
+
+	prev_Er = NULL;
+	for (nchild = nbody->child; nchild != NULL; nchild = nchild->next) {
+		if (nchild->tok != MDOC_It)
+			continue;
+		if ((nnext = nchild->head->child) == NULL)
+			continue;
+		if (nnext->type == ROFFT_BLOCK)
+			nnext = nnext->body->child;
+		if (nnext == NULL || nnext->tok != MDOC_Er)
+			continue;
+		nnext = nnext->child;
+		if (prev_Er != NULL) {
+			order = strcmp(prev_Er, nnext->string);
+			if (order > 0)
+				mandoc_vmsg(MANDOCERR_ER_ORDER,
+				    mdoc->parse, nnext->line, nnext->pos,
+				    "Er %s %s", prev_Er, nnext->string);
+			else if (order == 0)
+				mandoc_vmsg(MANDOCERR_ER_REP,
+				    mdoc->parse, nnext->line, nnext->pos,
+				    "Er %s", prev_Er);
+		}
+		prev_Er = nnext->string;
+	}
 }
 
 static void
@@ -1868,7 +2061,7 @@ post_sh_see_also(POST_ARGS)
 			if (isalpha((const unsigned char)*name))
 				return;
 		lastpunct = n->string;
-		if (n->next == NULL)
+		if (n->next == NULL || n->next->tok == MDOC_Rs)
 			mandoc_vmsg(MANDOCERR_XR_PUNCT, mdoc->parse,
 			    n->line, n->pos, "%s after %s(%s)",
 			    lastpunct, lastname, lastsec);
@@ -2004,9 +2197,9 @@ post_xr(POST_ARGS)
 	if (nch->next == NULL) {
 		mandoc_vmsg(MANDOCERR_XR_NOSEC, mdoc->parse,
 		    n->line, n->pos, "Xr %s", nch->string);
-		return;
-	}
-	assert(nch->next == n->last);
+	} else
+		assert(nch->next == n->last);
+	post_delim(mdoc);
 }
 
 static void
@@ -2015,6 +2208,9 @@ post_ignpar(POST_ARGS)
 	struct roff_node *np;
 
 	switch (mdoc->last->type) {
+	case ROFFT_BLOCK:
+		post_prevpar(mdoc);
+		return;
 	case ROFFT_HEAD:
 		post_hyph(mdoc);
 		return;
@@ -2061,7 +2257,7 @@ post_prevpar(POST_ARGS)
 
 	if (n->prev->tok != MDOC_Pp &&
 	    n->prev->tok != MDOC_Lp &&
-	    n->prev->tok != MDOC_br)
+	    n->prev->tok != ROFF_br)
 		return;
 	if (n->tok == MDOC_Bl && n->norm->Bl.comp)
 		return;
@@ -2082,10 +2278,10 @@ post_par(POST_ARGS)
 	struct roff_node *np;
 
 	np = mdoc->last;
-	if (np->tok != MDOC_br && np->tok != MDOC_sp)
+	if (np->tok != ROFF_br && np->tok != ROFF_sp)
 		post_prevpar(mdoc);
 
-	if (np->tok == MDOC_sp) {
+	if (np->tok == ROFF_sp) {
 		if (np->child != NULL && np->child->next != NULL)
 			mandoc_vmsg(MANDOCERR_ARG_EXCESS, mdoc->parse,
 			    np->child->next->line, np->child->next->pos,
@@ -2100,8 +2296,8 @@ post_par(POST_ARGS)
 		if (np->tok != MDOC_Sh && np->tok != MDOC_Ss)
 			return;
 	} else if (np->tok != MDOC_Pp && np->tok != MDOC_Lp &&
-	    (mdoc->last->tok != MDOC_br ||
-	     (np->tok != MDOC_sp && np->tok != MDOC_br)))
+	    (mdoc->last->tok != ROFF_br ||
+	     (np->tok != ROFF_sp && np->tok != ROFF_br)))
 		return;
 
 	mandoc_vmsg(MANDOCERR_PAR_SKIP, mdoc->parse,
@@ -2250,11 +2446,21 @@ static void
 post_bx(POST_ARGS)
 {
 	struct roff_node	*n, *nch;
+	const char		*macro;
 
+	post_delim(mdoc);
+
 	n = mdoc->last;
 	nch = n->child;
 
 	if (nch != NULL) {
+		macro = !strcmp(nch->string, "Open") ? "Ox" :
+		    !strcmp(nch->string, "Net") ? "Nx" :
+		    !strcmp(nch->string, "Free") ? "Fx" :
+		    !strcmp(nch->string, "DragonFly") ? "Dx" : NULL;
+		if (macro != NULL)
+			mandoc_msg(MANDOCERR_BX, mdoc->parse,
+			    n->line, n->pos, macro);
 		mdoc->last = nch;
 		nch = nch->next;
 		mdoc->next = ROFF_NEXT_SIBLING;
@@ -2321,11 +2527,11 @@ post_os(POST_ARGS)
 	mdoc->meta.os = NULL;
 	deroff(&mdoc->meta.os, n);
 	if (mdoc->meta.os)
-		return;
+		goto out;
 
 	if (mdoc->defos) {
 		mdoc->meta.os = mandoc_strdup(mdoc->defos);
-		return;
+		goto out;
 	}
 
 #ifdef OSNAME
@@ -2342,6 +2548,10 @@ post_os(POST_ARGS)
 	}
 	mdoc->meta.os = mandoc_strdup(defbuf);
 #endif /*!OSNAME*/
+
+out:	mdoc->meta.os_e = strstr(mdoc->meta.os, "OpenBSD") != NULL ?
+	    MDOC_OS_OPENBSD : strstr(mdoc->meta.os, "NetBSD") != NULL ?
+	    MDOC_OS_NETBSD : MDOC_OS_OTHER;
 }
 
 enum roff_sec