1. Eliminate struct eqn, instead use the existing members

of struct roff_node which is allocated for each equation anyway.
2. Do not keep a list of equation parsers, one parser is enough.
Minus fifty lines of code, no functional change.

13 files changed, 121 insertions, 197 deletions

diff --git a/usr.bin/mandoc/eqn.c b/usr.bin/mandoc/eqn.c
index fb65cb80f81..4de61175b38 100644
--- a/usr.bin/mandoc/eqn.c
+++ b/usr.bin/mandoc/eqn.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: eqn.c,v 1.38 2017/07/07 17:15:21 schwarze Exp $ */
+/*	$OpenBSD: eqn.c,v 1.39 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -25,8 +25,9 @@
 #include <string.h>
 #include <time.h>
 
-#include "mandoc.h"
 #include "mandoc_aux.h"
+#include "mandoc.h"
+#include "roff.h"
 #include "libmandoc.h"
 #include "libroff.h"
 
@@ -282,76 +283,48 @@ enum	parse_mode {
 };
 
 static	struct eqn_box	*eqn_box_alloc(struct eqn_node *, struct eqn_box *);
-static	void		 eqn_box_free(struct eqn_box *);
 static	struct eqn_box	*eqn_box_makebinary(struct eqn_node *,
 				struct eqn_box *);
 static	void		 eqn_def(struct eqn_node *);
 static	struct eqn_def	*eqn_def_find(struct eqn_node *);
 static	void		 eqn_delim(struct eqn_node *);
 static	enum eqn_tok	 eqn_next(struct eqn_node *, enum parse_mode);
-static	enum rofferr	 eqn_parse(struct eqn_node *, struct eqn_box *);
 static	void		 eqn_undef(struct eqn_node *);
 
 
-enum rofferr
-eqn_read(struct eqn_node **epp, int ln,
-		const char *p, int pos, int *offs)
+struct eqn_node *
+eqn_alloc(struct mparse *parse)
 {
-	size_t		 sz;
-	struct eqn_node	*ep;
-	enum rofferr	 er;
-
-	ep = *epp;
-
-	/*
-	 * If we're the terminating mark, unset our equation status and
-	 * validate the full equation.
-	 */
+	struct eqn_node *ep;
 
-	if (0 == strncmp(p, ".EN", 3)) {
-		er = eqn_end(epp);
-		p += 3;
-		while (' ' == *p || '\t' == *p)
-			p++;
-		if ('\0' == *p)
-			return er;
-		mandoc_vmsg(MANDOCERR_ARG_SKIP, ep->parse,
-		    ln, pos, "EN %s", p);
-		return er;
-	}
-
-	/*
-	 * Build up the full string, replacing all newlines with regular
-	 * whitespace.
-	 */
-
-	sz = strlen(p + pos) + 1;
-	ep->data = mandoc_realloc(ep->data, ep->sz + sz + 1);
-
-	/* First invocation: nil terminate the string. */
-
-	if (0 == ep->sz)
-		*ep->data = '\0';
-
-	ep->sz += sz;
-	strlcat(ep->data, p + pos, ep->sz + 1);
-	strlcat(ep->data, " ", ep->sz + 1);
-	return ROFF_IGN;
+	ep = mandoc_calloc(1, sizeof(*ep));
+	ep->parse = parse;
+	ep->gsize = EQN_DEFSIZE;
+	return ep;
 }
 
-struct eqn_node *
-eqn_alloc(int pos, int line, struct mparse *parse)
+void
+eqn_reset(struct eqn_node *ep)
 {
-	struct eqn_node	*p;
-
-	p = mandoc_calloc(1, sizeof(struct eqn_node));
+	free(ep->data);
+	ep->data = ep->start = ep->end = NULL;
+	ep->sz = ep->toksz = 0;
+}
 
-	p->parse = parse;
-	p->eqn.ln = line;
-	p->eqn.pos = pos;
-	p->gsize = EQN_DEFSIZE;
+void
+eqn_read(struct eqn_node *ep, const char *p)
+{
+	char		*cp;
 
-	return p;
+	if (ep->data == NULL) {
+		ep->sz = strlen(p);
+		ep->data = mandoc_strdup(p);
+	} else {
+		ep->sz = mandoc_asprintf(&cp, "%s %s", ep->data, p);
+		free(ep->data);
+		ep->data = cp;
+	}
+	ep->sz += 1;
 }
 
 /*
@@ -425,7 +398,7 @@ eqn_next(struct eqn_node *ep, enum parse_mode mode)
 			ep->start++;  /* Skip opening quote. */
 			if (ep->end == NULL) {
 				mandoc_msg(MANDOCERR_ARG_QUOTE, ep->parse,
-				    ep->eqn.ln, ep->eqn.pos, NULL);
+				    ep->node->line, ep->node->pos, NULL);
 				ep->end = strchr(ep->start, '\0');
 			}
 		} else {
@@ -446,7 +419,7 @@ eqn_next(struct eqn_node *ep, enum parse_mode mode)
 			break;
 		if (++lim > EQN_NEST_MAX) {
 			mandoc_msg(MANDOCERR_ROFFLOOP, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, NULL);
+			    ep->node->line, ep->node->pos, NULL);
 			return EQN_TOK_EOF;
 		}
 
@@ -490,7 +463,7 @@ eqn_next(struct eqn_node *ep, enum parse_mode mode)
 	return EQN_TOK__MAX;
 }
 
-static void
+void
 eqn_box_free(struct eqn_box *bp)
 {
 
@@ -568,7 +541,7 @@ eqn_delim(struct eqn_node *ep)
 {
 	if (ep->end[0] == '\0' || ep->end[1] == '\0') {
 		mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-		    ep->eqn.ln, ep->eqn.pos, "delim");
+		    ep->node->line, ep->node->pos, "delim");
 		if (ep->end[0] != '\0')
 			ep->end++;
 	} else if (strncmp(ep->end, "off", 3) == 0) {
@@ -595,7 +568,7 @@ eqn_undef(struct eqn_node *ep)
 
 	if (eqn_next(ep, MODE_NOSUB) == EQN_TOK_EOF) {
 		mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-		    ep->eqn.ln, ep->eqn.pos, "undef");
+		    ep->node->line, ep->node->pos, "undef");
 		return;
 	}
 	if ((def = eqn_def_find(ep)) == NULL)
@@ -614,7 +587,7 @@ eqn_def(struct eqn_node *ep)
 
 	if (eqn_next(ep, MODE_NOSUB) == EQN_TOK_EOF) {
 		mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-		    ep->eqn.ln, ep->eqn.pos, "define");
+		    ep->node->line, ep->node->pos, "define");
 		return;
 	}
 
@@ -643,7 +616,7 @@ eqn_def(struct eqn_node *ep)
 
 	if (eqn_next(ep, MODE_QUOTED) == EQN_TOK_EOF) {
 		mandoc_vmsg(MANDOCERR_REQ_EMPTY, ep->parse,
-		    ep->eqn.ln, ep->eqn.pos, "define %s", def->key);
+		    ep->node->line, ep->node->pos, "define %s", def->key);
 		free(def->key);
 		free(def->val);
 		def->key = def->val = NULL;
@@ -655,19 +628,17 @@ eqn_def(struct eqn_node *ep)
 	def->valsz = ep->toksz;
 }
 
-/*
- * Recursively parse an eqn(7) expression.
- */
-static enum rofferr
-eqn_parse(struct eqn_node *ep, struct eqn_box *parent)
+void
+eqn_parse(struct eqn_node *ep)
 {
-	struct eqn_box	*cur, *nbox, *split;
+	struct eqn_box	*cur, *nbox, *parent, *split;
 	const char	*cp, *cpn;
 	char		*p;
 	enum eqn_tok	 tok;
 	enum { CCL_LET, CCL_DIG, CCL_PUN } ccl, ccln;
 	int		 size;
 
+	parent = ep->node->eqn;
 	assert(parent != NULL);
 
 	/*
@@ -676,7 +647,7 @@ eqn_parse(struct eqn_node *ep, struct eqn_box *parent)
 	 */
 
 	if (ep->data == NULL)
-		return ROFF_IGN;
+		return;
 
 	ep->start = ep->end = ep->data + strspn(ep->data, " ^~");
 
@@ -694,7 +665,7 @@ next_tok:
 		if (eqn_next(ep, MODE_NOSUB) == EQN_TOK_EOF ||
 		    eqn_next(ep, MODE_QUOTED) == EQN_TOK_EOF)
 			mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, "tdefine");
+			    ep->node->line, ep->node->pos, "tdefine");
 		break;
 	case EQN_TOK_DELIM:
 		eqn_delim(ep);
@@ -702,7 +673,7 @@ next_tok:
 	case EQN_TOK_GFONT:
 		if (eqn_next(ep, MODE_SUB) == EQN_TOK_EOF)
 			mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 		break;
 	case EQN_TOK_MARK:
 	case EQN_TOK_LINEUP:
@@ -718,7 +689,7 @@ next_tok:
 	case EQN_TOK_DOTDOT:
 		if (parent->last == NULL) {
 			mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			cur = eqn_box_alloc(ep, parent);
 			cur->type = EQN_TEXT;
 			cur->text = mandoc_strdup("");
@@ -763,7 +734,7 @@ next_tok:
 	case EQN_TOK_UP:
 		if (eqn_next(ep, MODE_SUB) == EQN_TOK_EOF)
 			mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 		break;
 	case EQN_TOK_FAT:
 	case EQN_TOK_ROMAN:
@@ -801,13 +772,13 @@ next_tok:
 		/* Accept two values: integral size and a single. */
 		if (eqn_next(ep, MODE_SUB) == EQN_TOK_EOF) {
 			mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			break;
 		}
 		size = mandoc_strntoi(ep->start, ep->toksz, 10);
 		if (-1 == size) {
 			mandoc_msg(MANDOCERR_IT_NONUM, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			break;
 		}
 		if (EQN_TOK_GSIZE == tok) {
@@ -832,7 +803,7 @@ next_tok:
 		 */
 		if (parent->last == NULL) {
 			mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			cur = eqn_box_alloc(ep, parent);
 			cur->type = EQN_TEXT;
 			cur->text = mandoc_strdup("");
@@ -899,7 +870,7 @@ next_tok:
 		 */
 		if (parent->last == NULL) {
 			mandoc_msg(MANDOCERR_EQN_NOBOX, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			cur = eqn_box_alloc(ep, parent);
 			cur->type = EQN_TEXT;
 			cur->text = mandoc_strdup("");
@@ -926,15 +897,15 @@ next_tok:
 				break;
 		if (cur == NULL) {
 			mandoc_msg(MANDOCERR_BLK_NOTOPEN, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			break;
 		}
 		parent = cur;
 		if (EQN_TOK_RIGHT == tok) {
 			if (eqn_next(ep, MODE_SUB) == EQN_TOK_EOF) {
 				mandoc_msg(MANDOCERR_REQ_EMPTY,
-				    ep->parse, ep->eqn.ln,
-				    ep->eqn.pos, eqn_toks[tok]);
+				    ep->parse, ep->node->line,
+				    ep->node->pos, eqn_toks[tok]);
 				break;
 			}
 			/* Handling depends on right/left. */
@@ -969,7 +940,7 @@ next_tok:
 		if (EQN_TOK_LEFT == tok &&
 		    eqn_next(ep, MODE_SUB) == EQN_TOK_EOF) {
 			mandoc_msg(MANDOCERR_REQ_EMPTY, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			break;
 		}
 		parent = eqn_box_alloc(ep, parent);
@@ -1003,7 +974,7 @@ next_tok:
 				break;
 		if (cur == NULL) {
 			mandoc_msg(MANDOCERR_IT_STRAY, ep->parse,
-			    ep->eqn.ln, ep->eqn.pos, eqn_toks[tok]);
+			    ep->node->line, ep->node->pos, eqn_toks[tok]);
 			break;
 		}
 		parent = eqn_box_alloc(ep, cur);
@@ -1017,11 +988,7 @@ next_tok:
 		parent->expectargs = 1;
 		break;
 	case EQN_TOK_EOF:
-		/*
-		 * End of file!
-		 * TODO: make sure we're not in an open subexpression.
-		 */
-		return ROFF_EQN;
+		return;
 	case EQN_TOK__MAX:
 	case EQN_TOK_FUNC:
 	case EQN_TOK_QUOTED:
@@ -1118,26 +1085,11 @@ next_tok:
 	goto next_tok;
 }
 
-enum rofferr
-eqn_end(struct eqn_node **epp)
-{
-	struct eqn_node	*ep;
-
-	ep = *epp;
-	*epp = NULL;
-
-	ep->eqn.root = mandoc_calloc(1, sizeof(struct eqn_box));
-	ep->eqn.root->expectargs = UINT_MAX;
-	return eqn_parse(ep, ep->eqn.root);
-}
-
 void
 eqn_free(struct eqn_node *p)
 {
 	int		 i;
 
-	eqn_box_free(p->eqn.root);
-
 	for (i = 0; i < (int)p->defsz; i++) {
 		free(p->defs[i].key);
 		free(p->defs[i].val);
diff --git a/usr.bin/mandoc/eqn_html.c b/usr.bin/mandoc/eqn_html.c
index 82e68f2f400..b725bfc46c6 100644
--- a/usr.bin/mandoc/eqn_html.c
+++ b/usr.bin/mandoc/eqn_html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: eqn_html.c,v 1.11 2017/07/05 15:03:20 schwarze Exp $ */
+/*	$OpenBSD: eqn_html.c,v 1.12 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -225,14 +225,14 @@ out:
 }
 
 void
-print_eqn(struct html *p, const struct eqn *ep)
+print_eqn(struct html *p, const struct eqn_box *bp)
 {
 	struct tag	*t;
 
 	t = print_otag(p, TAG_MATH, "c", "eqn");
 
 	p->flags |= HTML_NONOSPACE;
-	eqn_box(p, ep->root);
+	eqn_box(p, bp);
 	p->flags &= ~HTML_NONOSPACE;
 
 	print_tagq(p, t);
diff --git a/usr.bin/mandoc/eqn_term.c b/usr.bin/mandoc/eqn_term.c
index 4a48e793318..8688fee848e 100644
--- a/usr.bin/mandoc/eqn_term.c
+++ b/usr.bin/mandoc/eqn_term.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: eqn_term.c,v 1.8 2017/07/07 19:06:15 schwarze Exp $ */
+/*	$OpenBSD: eqn_term.c,v 1.9 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -38,10 +38,10 @@ static void	eqn_box(struct termp *, const struct eqn_box *);
 
 
 void
-term_eqn(struct termp *p, const struct eqn *ep)
+term_eqn(struct termp *p, const struct eqn_box *bp)
 {
 
-	eqn_box(p, ep->root);
+	eqn_box(p, bp);
 	p->flags &= ~TERMP_NOSPACE;
 }
 
diff --git a/usr.bin/mandoc/html.h b/usr.bin/mandoc/html.h
index 94fd0594f4a..234ab44c60a 100644
--- a/usr.bin/mandoc/html.h
+++ b/usr.bin/mandoc/html.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: html.h,v 1.48 2017/06/23 02:31:39 schwarze Exp $ */
+/*	$OpenBSD: html.h,v 1.49 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -115,7 +115,7 @@ struct	html {
 
 struct	roff_node;
 struct	tbl_span;
-struct	eqn;
+struct	eqn_box;
 
 void		  roff_html_pre(struct html *, const struct roff_node *);
 
@@ -127,7 +127,7 @@ void		  print_stagq(struct html *, const struct tag *);
 void		  print_text(struct html *, const char *);
 void		  print_tblclose(struct html *);
 void		  print_tbl(struct html *, const struct tbl_span *);
-void		  print_eqn(struct html *, const struct eqn *);
+void		  print_eqn(struct html *, const struct eqn_box *);
 void		  print_paragraph(struct html *);
 void		  print_endline(struct html *);
 
diff --git a/usr.bin/mandoc/libmandoc.h b/usr.bin/mandoc/libmandoc.h
index 4b42b61b544..b526498a9d7 100644
--- a/usr.bin/mandoc/libmandoc.h
+++ b/usr.bin/mandoc/libmandoc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: libmandoc.h,v 1.53 2017/06/11 19:36:31 schwarze Exp $ */
+/*	$OpenBSD: libmandoc.h,v 1.54 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -24,7 +24,6 @@ enum	rofferr {
 	ROFF_SO, /* include another file */
 	ROFF_IGN, /* ignore current line */
 	ROFF_TBL, /* a table row was successfully parsed */
-	ROFF_EQN /* an equation was successfully parsed */
 };
 
 struct	buf {
@@ -35,7 +34,6 @@ struct	buf {
 
 struct	mparse;
 struct	tbl_span;
-struct	eqn;
 struct	roff;
 struct	roff_man;
 
@@ -77,4 +75,3 @@ int		 roff_getcontrol(const struct roff *,
 int		 roff_getformat(const struct roff *);
 
 const struct tbl_span	*roff_span(const struct roff *);
-const struct eqn	*roff_eqn(const struct roff *);
diff --git a/usr.bin/mandoc/libroff.h b/usr.bin/mandoc/libroff.h
index 3beca8c8b0e..532333a438d 100644
--- a/usr.bin/mandoc/libroff.h
+++ b/usr.bin/mandoc/libroff.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: libroff.h,v 1.18 2017/06/26 19:53:00 schwarze Exp $ */
+/*	$OpenBSD: libroff.h,v 1.19 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -38,9 +38,8 @@ struct	tbl_node {
 };
 
 struct	eqn_node {
-	struct eqn	  eqn;    /* syntax tree of this equation */
 	struct mparse	 *parse;  /* main parser, for error reporting */
-	struct eqn_node  *next;   /* singly linked list of equations */
+	struct roff_node *node;   /* syntax tree of this equation */
 	struct eqn_def	 *defs;   /* array of definitions */
 	char		 *data;   /* source code of this equation */
 	char		 *start;  /* first byte of the current token */
@@ -73,8 +72,9 @@ void		 tbl_data(struct tbl_node *, int, const char *, int);
 int		 tbl_cdata(struct tbl_node *, int, const char *, int);
 const struct tbl_span	*tbl_span(struct tbl_node *);
 int		 tbl_end(struct tbl_node **);
-struct eqn_node	*eqn_alloc(int, int, struct mparse *);
-enum rofferr	 eqn_end(struct eqn_node **);
+struct eqn_node	*eqn_alloc(struct mparse *);
+void		 eqn_box_free(struct eqn_box *);
 void		 eqn_free(struct eqn_node *);
-enum rofferr	 eqn_read(struct eqn_node **, int,
-			const char *, int, int *);
+void		 eqn_parse(struct eqn_node *);
+void		 eqn_read(struct eqn_node *, const char *);
+void		 eqn_reset(struct eqn_node *);
diff --git a/usr.bin/mandoc/mandoc.h b/usr.bin/mandoc/mandoc.h
index b78d886dcb7..8f4d4ee040a 100644
--- a/usr.bin/mandoc/mandoc.h
+++ b/usr.bin/mandoc/mandoc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mandoc.h,v 1.186 2017/07/07 19:39:17 schwarze Exp $ */
+/*	$OpenBSD: mandoc.h,v 1.187 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -402,17 +402,6 @@ struct	eqn_box {
 };
 
 /*
- * An equation consists of a tree of expressions starting at a given
- * line and position.
- */
-struct	eqn {
-	char		 *name; /* identifier (or NULL) */
-	struct eqn_box	 *root; /* root mathematical expression */
-	int		  ln; /* invocation line */
-	int		  pos; /* invocation position */
-};
-
-/*
  * Parse options.
  */
 #define	MPARSE_MDOC	1  /* assume -mdoc */
diff --git a/usr.bin/mandoc/read.c b/usr.bin/mandoc/read.c
index d5c9e6d47c8..3636e1c5658 100644
--- a/usr.bin/mandoc/read.c
+++ b/usr.bin/mandoc/read.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: read.c,v 1.161 2017/07/06 22:58:44 schwarze Exp $ */
+/*	$OpenBSD: read.c,v 1.162 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -536,14 +536,11 @@ rerun:
 		 * currently open parse.  Since we only get here if
 		 * there does exist data (see tbl_data.c), we're
 		 * guaranteed that something's been allocated.
-		 * Do the same for ROFF_EQN.
 		 */
 
 		if (rr == ROFF_TBL)
 			while ((span = roff_span(curp->roff)) != NULL)
 				roff_addtbl(curp->man, span);
-		else if (rr == ROFF_EQN)
-			roff_addeqn(curp->man, roff_eqn(curp->roff));
 		else if ((curp->man->macroset == MACROSET_MDOC ?
 		    mdoc_parseln(curp->man, curp->line, ln.buf, of) :
 		    man_parseln(curp->man, curp->line, ln.buf, of)) == 2)
diff --git a/usr.bin/mandoc/roff.c b/usr.bin/mandoc/roff.c
index 6d085c53b32..a645b02b464 100644
--- a/usr.bin/mandoc/roff.c
+++ b/usr.bin/mandoc/roff.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.c,v 1.190 2017/07/04 22:49:59 schwarze Exp $ */
+/*	$OpenBSD: roff.c,v 1.191 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -96,9 +96,8 @@ struct	roff {
 	struct tbl_node	*first_tbl; /* first table parsed */
 	struct tbl_node	*last_tbl; /* last table parsed */
 	struct tbl_node	*tbl; /* current table being parsed */
-	struct eqn_node	*last_eqn; /* last equation parsed */
-	struct eqn_node	*first_eqn; /* first equation parsed */
-	struct eqn_node	*eqn; /* current equation being parsed */
+	struct eqn_node	*last_eqn; /* equation parser */
+	struct eqn_node	*eqn; /* active equation parser */
 	int		 eqn_inline; /* current equation is inline */
 	int		 options; /* parse options */
 	int		 rstacksz; /* current size limit of rstack */
@@ -693,7 +692,6 @@ static void
 roff_free1(struct roff *r)
 {
 	struct tbl_node	*tbl;
-	struct eqn_node	*e;
 	int		 i;
 
 	while (NULL != (tbl = r->first_tbl)) {
@@ -702,11 +700,9 @@ roff_free1(struct roff *r)
 	}
 	r->first_tbl = r->last_tbl = r->tbl = NULL;
 
-	while (NULL != (e = r->first_eqn)) {
-		r->first_eqn = e->next;
-		eqn_free(e);
-	}
-	r->first_eqn = r->last_eqn = r->eqn = NULL;
+	if (r->last_eqn != NULL)
+		eqn_free(r->last_eqn);
+	r->last_eqn = r->eqn = NULL;
 
 	while (r->last)
 		roffnode_pop(r);
@@ -982,19 +978,6 @@ roff_body_alloc(struct roff_man *man, int line, int pos, int tok)
 }
 
 void
-roff_addeqn(struct roff_man *man, const struct eqn *eqn)
-{
-	struct roff_node	*n;
-
-	n = roff_node_alloc(man, eqn->ln, eqn->pos, ROFFT_EQN, TOKEN_NONE);
-	n->eqn = eqn;
-	if (eqn->ln > man->last->line)
-		n->flags |= NODE_LINE;
-	roff_node_append(man, n);
-	man->next = ROFF_NEXT_SIBLING;
-}
-
-void
 roff_addtbl(struct roff_man *man, const struct tbl_span *tbl)
 {
 	struct roff_node	*n;
@@ -1053,6 +1036,8 @@ roff_node_free(struct roff_node *n)
 		mdoc_argv_free(n->args);
 	if (n->type == ROFFT_BLOCK || n->type == ROFFT_ELEM)
 		free(n->norm);
+	if (n->eqn != NULL)
+		eqn_box_free(n->eqn);
 	free(n->string);
 	free(n);
 }
@@ -1510,8 +1495,10 @@ roff_parseln(struct roff *r, int ln, struct buf *buf, int *offs)
 			return e;
 		assert(e == ROFF_CONT);
 	}
-	if (r->eqn != NULL)
-		return eqn_read(&r->eqn, ln, buf->buf, ppos, offs);
+	if (r->eqn != NULL && strncmp(buf->buf + ppos, ".EN", 3)) {
+		eqn_read(r->eqn, buf->buf + ppos);
+		return ROFF_IGN;
+	}
 	if (r->tbl != NULL && ( ! ctl || buf->buf[pos] == '\0'))
 		return tbl_read(r->tbl, ln, buf->buf, ppos);
 	if ( ! ctl)
@@ -1591,8 +1578,9 @@ roff_endparse(struct roff *r)
 
 	if (r->eqn) {
 		mandoc_msg(MANDOCERR_BLK_NOEND, r->parse,
-		    r->eqn->eqn.ln, r->eqn->eqn.pos, "EQ");
-		eqn_end(&r->eqn);
+		    r->eqn->node->line, r->eqn->node->pos, "EQ");
+		eqn_parse(r->eqn);
+		r->eqn = NULL;
 	}
 
 	if (r->tbl) {
@@ -2875,20 +2863,23 @@ roff_eqndelim(struct roff *r, struct buf *buf, int pos)
 static enum rofferr
 roff_EQ(ROFF_ARGS)
 {
-	struct eqn_node *e;
-
-	assert(r->eqn == NULL);
-	e = eqn_alloc(ppos, ln, r->parse);
+	struct roff_node	*n;
 
-	if (r->last_eqn) {
-		r->last_eqn->next = e;
-		e->delim = r->last_eqn->delim;
-		e->odelim = r->last_eqn->odelim;
-		e->cdelim = r->last_eqn->cdelim;
-	} else
-		r->first_eqn = r->last_eqn = e;
+	n = roff_node_alloc(r->man, ln, ppos, ROFFT_EQN, TOKEN_NONE);
+	if (ln > r->man->last->line)
+		n->flags |= NODE_LINE;
+	n->eqn = mandoc_calloc(1, sizeof(*n->eqn));
+	n->eqn->expectargs = UINT_MAX;
+	roff_node_append(r->man, n);
+	r->man->next = ROFF_NEXT_SIBLING;
 
-	r->eqn = r->last_eqn = e;
+	assert(r->eqn == NULL);
+	if (r->last_eqn == NULL)
+		r->last_eqn = eqn_alloc(r->parse);
+	else
+		eqn_reset(r->last_eqn);
+	r->eqn = r->last_eqn;
+	r->eqn->node = n;
 
 	if (buf->buf[pos] != '\0')
 		mandoc_vmsg(MANDOCERR_ARG_SKIP, r->parse, ln, pos,
@@ -2900,8 +2891,14 @@ roff_EQ(ROFF_ARGS)
 static enum rofferr
 roff_EN(ROFF_ARGS)
 {
-
-	mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse, ln, ppos, "EN");
+	if (r->eqn != NULL) {
+		eqn_parse(r->eqn);
+		r->eqn = NULL;
+	} else
+		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse, ln, ppos, "EN");
+	if (buf->buf[pos] != '\0')
+		mandoc_vmsg(MANDOCERR_ARG_SKIP, r->parse, ln, pos,
+		    "EN %s", buf->buf + pos);
 	return ROFF_IGN;
 }
 
@@ -3608,13 +3605,6 @@ roff_span(const struct roff *r)
 	return r->tbl ? tbl_span(r->tbl) : NULL;
 }
 
-const struct eqn *
-roff_eqn(const struct roff *r)
-{
-
-	return r->last_eqn ? &r->last_eqn->eqn : NULL;
-}
-
 /*
  * Duplicate an input string, making the appropriate character
  * conversations (as stipulated by `tr') along the way.
diff --git a/usr.bin/mandoc/roff.h b/usr.bin/mandoc/roff.h
index a7ffc1dcd3b..2be8356de08 100644
--- a/usr.bin/mandoc/roff.h
+++ b/usr.bin/mandoc/roff.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff.h,v 1.39 2017/06/25 07:23:53 bentley Exp $	*/
+/*	$OpenBSD: roff.h,v 1.40 2017/07/08 14:51:01 schwarze Exp $	*/
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013, 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -499,7 +499,7 @@ struct	roff_node {
 	union mdoc_data	 *norm;    /* Normalized arguments. */
 	char		 *string;  /* TEXT */
 	const struct tbl_span *span; /* TBL */
-	const struct eqn *eqn;	   /* EQN */
+	struct eqn_box	 *eqn;     /* EQN */
 	int		  line;    /* Input file line number. */
 	int		  pos;     /* Input file column number. */
 	int		  flags;
diff --git a/usr.bin/mandoc/roff_int.h b/usr.bin/mandoc/roff_int.h
index bae90e44987..e8b7592fde7 100644
--- a/usr.bin/mandoc/roff_int.h
+++ b/usr.bin/mandoc/roff_int.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff_int.h,v 1.7 2015/11/07 13:57:55 schwarze Exp $	*/
+/*	$OpenBSD: roff_int.h,v 1.8 2017/07/08 14:51:01 schwarze Exp $	*/
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -25,7 +25,6 @@ void		  roff_elem_alloc(struct roff_man *, int, int, int);
 struct roff_node *roff_block_alloc(struct roff_man *, int, int, int);
 struct roff_node *roff_head_alloc(struct roff_man *, int, int, int);
 struct roff_node *roff_body_alloc(struct roff_man *, int, int, int);
-void		  roff_addeqn(struct roff_man *, const struct eqn *);
 void		  roff_addtbl(struct roff_man *, const struct tbl_span *);
 void		  roff_node_unlink(struct roff_man *, struct roff_node *);
 void		  roff_node_free(struct roff_node *);
diff --git a/usr.bin/mandoc/term.h b/usr.bin/mandoc/term.h
index 6a8ef603ba2..792fc093b8d 100644
--- a/usr.bin/mandoc/term.h
+++ b/usr.bin/mandoc/term.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: term.h,v 1.73 2017/06/17 14:55:02 schwarze Exp $ */
+/*	$OpenBSD: term.h,v 1.74 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -36,7 +36,7 @@ enum	termfont {
 	TERMFONT__MAX
 };
 
-struct	eqn;
+struct	eqn_box;
 struct	roff_meta;
 struct	roff_node;
 struct	tbl_span;
@@ -126,7 +126,7 @@ const char	 *ascii_uc2str(int);
 
 void		  roff_term_pre(struct termp *, const struct roff_node *);
 
-void		  term_eqn(struct termp *, const struct eqn *);
+void		  term_eqn(struct termp *, const struct eqn_box *);
 void		  term_tbl(struct termp *, const struct tbl_span *);
 void		  term_free(struct termp *);
 void		  term_setcol(struct termp *, size_t);
diff --git a/usr.bin/mandoc/tree.c b/usr.bin/mandoc/tree.c
index b217ad87078..e7c163b2817 100644
--- a/usr.bin/mandoc/tree.c
+++ b/usr.bin/mandoc/tree.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tree.c,v 1.43 2017/07/07 19:39:17 schwarze Exp $ */
+/*	$OpenBSD: tree.c,v 1.44 2017/07/08 14:51:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013, 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -200,7 +200,7 @@ print_mdoc(const struct roff_node *n, int indent)
 	}
 
 	if (n->eqn)
-		print_box(n->eqn->root->first, indent + 4);
+		print_box(n->eqn->first, indent + 4);
 	if (n->child)
 		print_mdoc(n->child, indent +
 		    (n->type == ROFFT_BLOCK ? 2 : 4));
@@ -285,7 +285,7 @@ print_man(const struct roff_node *n, int indent)
 	}
 
 	if (n->eqn)
-		print_box(n->eqn->root->first, indent + 4);
+		print_box(n->eqn->first, indent + 4);
 	if (n->child)
 		print_man(n->child, indent +
 		    (n->type == ROFFT_BLOCK ? 2 : 4));