Allow roff_parseln() to be re-run.

Allow roff_parseln() to manipulate the line buffer offset.  This is used
in situations like `.ie n .TH FOO 1' or `.ie n .ie n', where the line
buffer offset is recalculated then the roff parser re-run.
Fix mdoc_parseln() and man_parseln() to accept the initial line offset.
WARNING: backed-out ALL roff macros whilst accomodating for how roff
handles multi-line conditionals (in short, re-running the parser).

7 files changed, 213 insertions, 106 deletions

diff --git a/main.c b/main.c
index 730d4397..7ad8a3e5 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$Id: main.c,v 1.75 2010/05/16 00:04:46 kristaps Exp $ */
+/*	$Id: main.c,v 1.76 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -386,7 +386,7 @@ static void
 fdesc(struct curparse *curp)
 {
 	struct buf	 ln, blk;
-	int		 i, pos, lnn, lnn_start, with_mmap;
+	int		 i, pos, lnn, lnn_start, with_mmap, of;
 	enum rofferr	 re;
 	struct man	*man;
 	struct mdoc	*mdoc;
@@ -467,22 +467,42 @@ fdesc(struct curparse *curp)
 				goto bailout;
 		ln.buf[pos] = '\0';
 
-		re = roff_parseln(roff, lnn_start, &ln.buf, &ln.sz);
+		/*
+		 * A significant amount of complexity is contained by
+		 * the roff preprocessor.  It's line-oriented but can be
+		 * expressed on one line, so we need at times to
+		 * readjust our starting point and re-run it.  The roff
+		 * preprocessor can also readjust the buffers with new
+		 * data, so we pass them in wholesale.
+		 */
+
+		of = 0;
+		do {
+			re = roff_parseln(roff, lnn_start, 
+					&ln.buf, &ln.sz, of, &of);
+		} while (ROFF_RERUN == re);
+
 		if (ROFF_IGN == re)
 			continue;
 		else if (ROFF_ERR == re)
 			goto bailout;
 
-		/* If unset, assign parser in pset(). */
+		/*
+		 * If input parsers have not been allocated, do so now.
+		 * We keep these instanced betwen parsers, but set them
+		 * locally per parse routine since we can use different
+		 * parsers with each one.
+		 */
 
-		if ( ! (man || mdoc) && ! pset(ln.buf, pos, curp, &man, &mdoc))
-			goto bailout;
+		if ( ! (man || mdoc))
+			if ( ! pset(ln.buf + of, pos - of, curp, &man, &mdoc))
+				goto bailout;
 
-		/* Pass down into parsers. */
+		/* Lastly, push down into the parsers themselves. */
 
-		if (man && ! man_parseln(man, lnn_start, ln.buf))
+		if (man && ! man_parseln(man, lnn_start, ln.buf, of))
 			goto bailout;
-		if (mdoc && ! mdoc_parseln(mdoc, lnn_start, ln.buf))
+		if (mdoc && ! mdoc_parseln(mdoc, lnn_start, ln.buf, of))
 			goto bailout;
 	}
 
@@ -493,6 +513,8 @@ fdesc(struct curparse *curp)
 		goto bailout;
 	}
 
+	/* Clean up the parse routine ASTs. */
+
 	if (mdoc && ! mdoc_endparse(mdoc))
 		goto bailout;
 	if (man && ! man_endparse(man))
diff --git a/man.c b/man.c
index a1a0ecd4..975a82f8 100644
--- a/man.c
+++ b/man.c
@@ -1,4 +1,4 @@
-/*	$Id: man.c,v 1.71 2010/05/16 00:04:46 kristaps Exp $ */
+/*	$Id: man.c,v 1.72 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -74,11 +74,11 @@ static	int		 man_node_append(struct man *,
 static	void		 man_node_free(struct man_node *);
 static	void		 man_node_unlink(struct man *, 
 				struct man_node *);
-static	int		 man_ptext(struct man *, int, char *);
-static	int		 man_pmacro(struct man *, int, char *);
+static	int		 man_ptext(struct man *, int, char *, int);
+static	int		 man_pmacro(struct man *, int, char *, int);
 static	void		 man_free1(struct man *);
 static	void		 man_alloc1(struct man *);
-static	int		 macrowarn(struct man *, int, const char *);
+static	int		 macrowarn(struct man *, int, const char *, int);
 
 
 const struct man_node *
@@ -148,12 +148,15 @@ man_endparse(struct man *m)
 
 
 int
-man_parseln(struct man *m, int ln, char *buf)
+man_parseln(struct man *m, int ln, char *buf, int offs)
 {
 
-	return(('.' == *buf || '\'' == *buf) ? 
-			man_pmacro(m, ln, buf) : 
-			man_ptext(m, ln, buf));
+	if (MAN_HALT & m->flags)
+		return(0);
+
+	return(('.' == buf[offs] || '\'' == buf[offs]) ? 
+			man_pmacro(m, ln, buf, offs) : 
+			man_ptext(m, ln, buf, offs));
 }
 
 
@@ -363,31 +366,33 @@ man_node_delete(struct man *m, struct man_node *p)
 
 
 static int
-man_ptext(struct man *m, int line, char *buf)
+man_ptext(struct man *m, int line, char *buf, int offs)
 {
 	int		 i;
 
 	/* Ignore bogus comments. */
 
-	if ('\\' == buf[0] && '.' == buf[1] && '\"' == buf[2])
-		return(man_pwarn(m, line, 0, WBADCOMMENT));
+	if ('\\' == buf[offs] && 
+			'.' == buf[offs + 1] && 
+			'"' == buf[offs + 2])
+		return(man_pwarn(m, line, offs, WBADCOMMENT));
 
 	/* Literal free-form text whitespace is preserved. */
 
 	if (MAN_LITERAL & m->flags) {
-		if ( ! man_word_alloc(m, line, 0, buf))
+		if ( ! man_word_alloc(m, line, offs, buf + offs))
 			return(0);
 		goto descope;
 	}
 
 	/* Pump blank lines directly into the backend. */
 
-	for (i = 0; ' ' == buf[i]; i++)
+	for (i = offs; ' ' == buf[i]; i++)
 		/* Skip leading whitespace. */ ;
 
 	if ('\0' == buf[i]) {
 		/* Allocate a blank entry. */
-		if ( ! man_word_alloc(m, line, 0, ""))
+		if ( ! man_word_alloc(m, line, offs, ""))
 			return(0);
 		goto descope;
 	}
@@ -414,7 +419,7 @@ man_ptext(struct man *m, int line, char *buf)
 		buf[i] = '\0';
 	}
 
-	if ( ! man_word_alloc(m, line, 0, buf))
+	if ( ! man_word_alloc(m, line, offs, buf + offs))
 		return(0);
 
 	/*
@@ -423,10 +428,7 @@ man_ptext(struct man *m, int line, char *buf)
 	 * sentence.  The front-end will know how to interpret this.
 	 */
 
-	/* FIXME: chain of close delims. */
-
 	assert(i);
-
 	if (mandoc_eos(buf, (size_t)i))
 		m->last->flags |= MAN_EOS;
 
@@ -449,23 +451,23 @@ descope:
 
 	if ( ! man_unscope(m, m->last->parent, WERRMAX))
 		return(0);
-	return(man_body_alloc(m, line, 0, m->last->tok));
+	return(man_body_alloc(m, line, offs, m->last->tok));
 }
 
 
 static int
-macrowarn(struct man *m, int ln, const char *buf)
+macrowarn(struct man *m, int ln, const char *buf, int offs)
 {
 	if ( ! (MAN_IGN_MACRO & m->pflags))
-		return(man_verr(m, ln, 0, "unknown macro: %s%s", 
+		return(man_verr(m, ln, offs, "unknown macro: %s%s", 
 				buf, strlen(buf) > 3 ? "..." : ""));
-	return(man_vwarn(m, ln, 0, "unknown macro: %s%s",
+	return(man_vwarn(m, ln, offs, "unknown macro: %s%s",
 				buf, strlen(buf) > 3 ? "..." : ""));
 }
 
 
 int
-man_pmacro(struct man *m, int ln, char *buf)
+man_pmacro(struct man *m, int ln, char *buf, int offs)
 {
 	int		 i, j, ppos;
 	enum mant	 tok;
@@ -474,10 +476,12 @@ man_pmacro(struct man *m, int ln, char *buf)
 
 	/* Comments and empties are quickly ignored. */
 
-	if ('\0' == buf[1])
+	offs++;
+
+	if ('\0' == buf[offs])
 		return(1);
 
-	i = 1;
+	i = offs;
 
 	/*
 	 * Skip whitespace between the control character and initial
@@ -522,7 +526,7 @@ man_pmacro(struct man *m, int ln, char *buf)
 	}
 	
 	if (MAN_MAX == (tok = man_hash_find(mac))) {
-		if ( ! macrowarn(m, ln, mac))
+		if ( ! macrowarn(m, ln, mac, ppos))
 			goto err;
 		return(1);
 	}
@@ -628,7 +632,7 @@ out:
 
 	if ( ! man_unscope(m, m->last->parent, WERRMAX))
 		return(0);
-	return(man_body_alloc(m, ln, 0, m->last->tok));
+	return(man_body_alloc(m, ln, offs, m->last->tok));
 
 err:	/* Error out. */
 
diff --git a/man.h b/man.h
index a0ea681a..739cf8ba 100644
--- a/man.h
+++ b/man.h
@@ -1,4 +1,4 @@
-/*	$Id: man.h,v 1.32 2010/05/15 22:44:04 kristaps Exp $ */
+/*	$Id: man.h,v 1.33 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -111,7 +111,7 @@ struct	man;
 void	 	  man_free(struct man *);
 struct	man	 *man_alloc(void *, int, const struct man_cb *);
 void		  man_reset(struct man *);
-int	 	  man_parseln(struct man *, int, char *buf);
+int	 	  man_parseln(struct man *, int, char *, int);
 int		  man_endparse(struct man *);
 
 const struct man_node *man_node(const struct man *);
diff --git a/mdoc.c b/mdoc.c
index e521e27b..dc35f85e 100644
--- a/mdoc.c
+++ b/mdoc.c
@@ -1,4 +1,4 @@
-/*	$Id: mdoc.c,v 1.134 2010/05/16 00:04:46 kristaps Exp $ */
+/*	$Id: mdoc.c,v 1.135 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -150,9 +150,10 @@ static	struct mdoc_node *node_alloc(struct mdoc *, int, int,
 				enum mdoct, enum mdoc_type);
 static	int		  node_append(struct mdoc *, 
 				struct mdoc_node *);
-static	int		  mdoc_ptext(struct mdoc *, int, char *);
-static	int		  mdoc_pmacro(struct mdoc *, int, char *);
-static	int		  macrowarn(struct mdoc *, int, const char *);
+static	int		  mdoc_ptext(struct mdoc *, int, char *, int);
+static	int		  mdoc_pmacro(struct mdoc *, int, char *, int);
+static	int		  macrowarn(struct mdoc *, int, 
+				const char *, int);
 
 
 const struct mdoc_node *
@@ -284,16 +285,16 @@ mdoc_endparse(struct mdoc *m)
  * the macro (mdoc_pmacro()) or text parser (mdoc_ptext()).
  */
 int
-mdoc_parseln(struct mdoc *m, int ln, char *buf)
+mdoc_parseln(struct mdoc *m, int ln, char *buf, int offs)
 {
 
 	if (MDOC_HALT & m->flags)
 		return(0);
 
 	m->flags |= MDOC_NEWLINE;
-	return(('.' == *buf || '\'' == *buf) ? 
-			mdoc_pmacro(m, ln, buf) :
-			mdoc_ptext(m, ln, buf));
+	return(('.' == buf[offs] || '\'' == buf[offs]) ? 
+			mdoc_pmacro(m, ln, buf, offs) :
+			mdoc_ptext(m, ln, buf, offs));
 }
 
 
@@ -630,32 +631,34 @@ mdoc_node_delete(struct mdoc *m, struct mdoc_node *p)
  * control character.
  */
 static int
-mdoc_ptext(struct mdoc *m, int line, char *buf)
+mdoc_ptext(struct mdoc *m, int line, char *buf, int offs)
 {
 	int		 i;
 
 	/* Ignore bogus comments. */
 
-	if ('\\' == buf[0] && '.' == buf[1] && '\"' == buf[2])
-		return(mdoc_pwarn(m, line, 0, EBADCOMMENT));
+	if ('\\' == buf[offs] && 
+			'.' == buf[offs + 1] && 
+			'"' == buf[offs + 2])
+		return(mdoc_pwarn(m, line, offs, EBADCOMMENT));
 
 	/* No text before an initial macro. */
 
 	if (SEC_NONE == m->lastnamed)
-		return(mdoc_perr(m, line, 0, ETEXTPROL));
+		return(mdoc_perr(m, line, offs, ETEXTPROL));
 
 	/* Literal just gets pulled in as-is. */
 	
 	if (MDOC_LITERAL & m->flags)
-		return(mdoc_word_alloc(m, line, 0, buf));
+		return(mdoc_word_alloc(m, line, offs, buf + offs));
 
 	/* Check for a blank line, which may also consist of spaces. */
 
-	for (i = 0; ' ' == buf[i]; i++)
+	for (i = offs; ' ' == buf[i]; i++)
 		/* Skip to first non-space. */ ;
 
 	if ('\0' == buf[i]) {
-		if ( ! mdoc_pwarn(m, line, 0, ENOBLANK))
+		if ( ! mdoc_pwarn(m, line, offs, ENOBLANK))
 			return(0);
 
 		/*
@@ -663,7 +666,7 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 		 * blank lines aren't allowed, but enough manuals assume this
 		 * behaviour that we want to work around it.
 		 */
-		if ( ! mdoc_elem_alloc(m, line, 0, MDOC_Pp, NULL))
+		if ( ! mdoc_elem_alloc(m, line, offs, MDOC_Pp, NULL))
 			return(0);
 
 		m->next = MDOC_NEXT_SIBLING;
@@ -694,7 +697,7 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 
 	/* Allocate the whole word. */
 
-	if ( ! mdoc_word_alloc(m, line, 0, buf))
+	if ( ! mdoc_word_alloc(m, line, offs, buf + offs))
 		return(0);
 
 	/*
@@ -703,10 +706,7 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 	 * sentence.  The front-end will know how to interpret this.
 	 */
 
-	/* FIXME: chain of close delims. */
-
 	assert(i);
-
 	if (mandoc_eos(buf, (size_t)i))
 		m->last->flags |= MDOC_EOS;
 
@@ -715,12 +715,12 @@ mdoc_ptext(struct mdoc *m, int line, char *buf)
 
 
 static int
-macrowarn(struct mdoc *m, int ln, const char *buf)
+macrowarn(struct mdoc *m, int ln, const char *buf, int offs)
 {
 	if ( ! (MDOC_IGN_MACRO & m->pflags))
-		return(mdoc_verr(m, ln, 0, "unknown macro: %s%s", 
+		return(mdoc_verr(m, ln, offs, "unknown macro: %s%s", 
 				buf, strlen(buf) > 3 ? "..." : ""));
-	return(mdoc_vwarn(m, ln, 0, "unknown macro: %s%s",
+	return(mdoc_vwarn(m, ln, offs, "unknown macro: %s%s",
 				buf, strlen(buf) > 3 ? "..." : ""));
 }
 
@@ -730,7 +730,7 @@ macrowarn(struct mdoc *m, int ln, const char *buf)
  * character.
  */
 int
-mdoc_pmacro(struct mdoc *m, int ln, char *buf)
+mdoc_pmacro(struct mdoc *m, int ln, char *buf, int offs)
 {
 	enum mdoct	tok;
 	int		i, j, sv;
@@ -738,10 +738,12 @@ mdoc_pmacro(struct mdoc *m, int ln, char *buf)
 
 	/* Empty lines are ignored. */
 
-	if ('\0' == buf[1])
+	offs++;
+
+	if ('\0' == buf[offs])
 		return(1);
 
-	i = 1;
+	i = offs;
 
 	/* Accept whitespace after the initial control char. */
 
@@ -770,16 +772,16 @@ mdoc_pmacro(struct mdoc *m, int ln, char *buf)
 		return(mdoc_perr(m, ln, i, EPRINT));
 	}
 
-	mac[j] = 0;
+	mac[j] = '\0';
 
 	if (j == 4 || j < 2) {
-		if ( ! macrowarn(m, ln, mac))
+		if ( ! macrowarn(m, ln, mac, sv))
 			goto err;
 		return(1);
 	} 
 	
 	if (MDOC_MAX == (tok = mdoc_hash_find(mac))) {
-		if ( ! macrowarn(m, ln, mac))
+		if ( ! macrowarn(m, ln, mac, sv))
 			goto err;
 		return(1);
 	}
diff --git a/mdoc.h b/mdoc.h
index 0c9408bb..bfec2f12 100644
--- a/mdoc.h
+++ b/mdoc.h
@@ -1,4 +1,4 @@
-/*	$Id: mdoc.h,v 1.79 2010/05/15 16:24:38 kristaps Exp $ */
+/*	$Id: mdoc.h,v 1.80 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -299,7 +299,7 @@ struct	mdoc;
 void	 	  mdoc_free(struct mdoc *);
 struct	mdoc	 *mdoc_alloc(void *, int, const struct mdoc_cb *);
 void		  mdoc_reset(struct mdoc *);
-int	 	  mdoc_parseln(struct mdoc *, int, char *buf);
+int	 	  mdoc_parseln(struct mdoc *, int, char *, int);
 const struct mdoc_node *mdoc_node(const struct mdoc *);
 const struct mdoc_meta *mdoc_meta(const struct mdoc *);
 int		  mdoc_endparse(struct mdoc *);
diff --git a/roff.c b/roff.c
index 4cdbd4a2..6fa48917 100644
--- a/roff.c
+++ b/roff.c
@@ -1,4 +1,4 @@
-/*	$Id: roff.c,v 1.73 2010/05/15 22:28:22 kristaps Exp $ */
+/*	$Id: roff.c,v 1.74 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -26,12 +26,15 @@
 #include "roff.h"
 
 enum	rofft {
-	ROFF_de,
-	ROFF_dei,
+#if 0
 	ROFF_am,
 	ROFF_ami,
+	ROFF_de,
+	ROFF_dei,
+	ROFF_if,
 	ROFF_ig,
 	ROFF_close,
+#endif
 	ROFF_MAX
 };
 
@@ -44,9 +47,11 @@ struct	roff {
 struct	roffnode {
 	enum rofft	 tok; /* type of node */
 	struct roffnode	*parent; /* up one in stack */
-	char		*end; /* custom end-token */
+	char		*end; /* end-token: custom */
 	int		 line; /* parse line */
 	int		 col; /* parse col */
+	int		 flags;
+#define	ROFF_PARSEONLY	(1 << 0)
 };
 
 #define	ROFF_ARGS	 struct roff *r, /* parse ctx */ \
@@ -54,7 +59,8 @@ struct	roffnode {
 		 	 char **bufp, /* input buffer */ \
 			 size_t *szp, /* size of input buffer */ \
 			 int ln, /* parse line */ \
-			 int ppos /* current pos in buffer */
+			 int ppos, /* current pos in buffer */ \
+			 int *offs /* reset offset of buffer data */
 
 typedef	enum rofferr (*roffproc)(ROFF_ARGS);
 
@@ -64,17 +70,24 @@ struct	roffmac {
 	roffproc	 new; /* root of stack (type = ROFF_MAX) */
 };
 
+#if 0
 static	enum rofferr	 roff_new_close(ROFF_ARGS);
+static	enum rofferr	 roff_new_if(ROFF_ARGS);
+static	enum rofferr	 roff_sub_if(ROFF_ARGS);
 static	enum rofferr	 roff_new_ig(ROFF_ARGS);
 static	enum rofferr	 roff_sub_ig(ROFF_ARGS);
+#endif
 
 const	struct roffmac	 roffs[ROFF_MAX] = {
-	{ "de", roff_sub_ig, roff_new_ig },
-	{ "dei", roff_sub_ig, roff_new_ig },
+#if 0
 	{ "am", roff_sub_ig, roff_new_ig },
 	{ "ami", roff_sub_ig, roff_new_ig },
+	{ "de", roff_sub_ig, roff_new_ig },
+	{ "dei", roff_sub_ig, roff_new_ig },
+	{ "if", roff_sub_if, roff_new_if },
 	{ "ig", roff_sub_ig, roff_new_ig },
 	{ ".", NULL, roff_new_close },
+#endif
 };
 
 static	void		 roff_free1(struct roff *);
@@ -116,6 +129,8 @@ roffnode_pop(struct roff *r)
 	if (NULL == (p = r->last))
 		return;
 	r->last = p->parent;
+	if (p->end)
+		free(p->end);
 	free(p);
 }
 
@@ -187,30 +202,42 @@ roff_alloc(const mandocmsg msg, void *data)
 
 
 enum rofferr
-roff_parseln(struct roff *r, int ln, char **bufp, size_t *szp)
+roff_parseln(struct roff *r, int ln, 
+		char **bufp, size_t *szp, int pos, int *offs)
 {
 	enum rofft	 t;
-	int		 ppos;
+
+	/* If stacked, jump directly into its processing function. */
 
 	if (NULL != r->last) {
-		/*
-		 * If there's a node on the stack, then jump directly
-		 * into its processing function.
-		 */
 		t = r->last->tok;
 		assert(roffs[t].sub);
-		return((*roffs[t].sub)(r, t, bufp, szp, ln, 0));
-	} else if ('.' != (*bufp)[0] && NULL == r->last)
-		/* Return when in free text without a context. */
+		return((*roffs[t].sub)(r, t, bufp, szp, ln, pos, offs));
+	} 
+	
+	/* Return when in free text without a context. */
+
+	if ('.' != (*bufp)[0] && '\'' != (*bufp)[0] && NULL == r->last)
 		return(ROFF_CONT);
 
 	/* There's nothing on the stack: make us anew. */
 
-	if (ROFF_MAX == (t = roff_parse(*bufp, &ppos)))
+	if (ROFF_MAX == (t = roff_parse(*bufp, &pos)))
 		return(ROFF_CONT);
 
 	assert(roffs[t].new);
-	return((*roffs[t].new)(r, t, bufp, szp, ln, ppos));
+	return((*roffs[t].new)(r, t, bufp, szp, ln, pos, offs));
+}
+
+
+int
+roff_endparse(struct roff *r)
+{
+
+	if (NULL == r->last)
+		return(1);
+	return((*r->msg)(MANDOCERR_SCOPEEXIT, r->data, r->last->line, 
+				r->last->col, NULL));
 }
 
 
@@ -225,7 +252,7 @@ roff_parse(const char *buf, int *pos)
 	char		 mac[5];
 	enum rofft	 t;
 
-	assert('.' == buf[0]);
+	assert('.' == buf[0] || '\'' == buf[0]);
 	*pos = 1;
 
 	while (buf[*pos] && (' ' == buf[*pos] || '\t' == buf[*pos]))
@@ -255,6 +282,7 @@ roff_parse(const char *buf, int *pos)
 }
 
 
+#if 0
 /* ARGSUSED */
 static enum rofferr
 roff_sub_ig(ROFF_ARGS)
@@ -263,7 +291,7 @@ roff_sub_ig(ROFF_ARGS)
 
 	/* Ignore free-text lines. */
 
-	if ('.' != (*bufp)[ppos])
+	if ('.' != (*bufp)[ppos] && '\'' != (*bufp)[ppos])
 		return(ROFF_IGN);
 
 	if (r->last->end) {
@@ -310,7 +338,61 @@ roff_new_close(ROFF_ARGS)
 }
 
 
-/* ARGSUSED */
+static enum rofferr
+roff_sub_if(ROFF_ARGS)
+{
+	int		 i;
+	enum rofft	 t;
+
+	i = (int)strlen(*bufp);
+
+	if (i > 1 && '}' == (*bufp)[i - 1] && '\\' == (*bufp)[i - 2])
+		roffnode_pop(r);
+
+	return(ROFF_IGN);
+}
+
+
+static enum rofferr
+roff_new_if(ROFF_ARGS)
+{
+	struct roffnode	*n;
+	enum rofferr	 re;
+
+	/*
+	 * Read ahead past the conditional.
+	 * FIXME: this does not work, as conditionals don't end on
+	 * whitespace, but are parsed according to a formal grammar.
+	 * It's good enough for now, however.
+	 */
+
+	while ((*bufp)[ppos] && ' ' != (*bufp)[ppos])
+		ppos++;
+	while (' ' == (*bufp)[ppos])
+		ppos++;
+
+	if ( ! roffnode_push(r, tok, ln, ppos))
+		return(ROFF_ERR);
+
+	n = r->last;
+
+	/* Don't evaluate: just assume NO. */
+
+	r->last->flags |= ROFF_PARSEONLY;
+
+	if ('\\' == (*bufp)[ppos] && '{' == (*bufp)[ppos + 1]) {
+		re = roff_parseln(r, ln, bufp, szp, pos);
+		if (ROFF_ERR == re)
+			return(re);
+		if (r->last == n)
+			roffnode_pop(r, tok, ln, ppos);
+		return(re);
+	}
+
+	return(ROFF_IGN);
+}
+
+
 static enum rofferr
 roff_new_ig(ROFF_ARGS)
 {
@@ -318,6 +400,11 @@ roff_new_ig(ROFF_ARGS)
 
 	if ( ! roffnode_push(r, tok, ln, ppos))
 		return(ROFF_ERR);
+	
+	/*
+	 * Other macros (not `ig') using this routine have additional
+	 * crap here that we discard. 
+	 */
 
 	if (ROFF_ig != tok) {
 		while ((*bufp)[ppos] && ' ' != (*bufp)[ppos])
@@ -360,14 +447,4 @@ roff_new_ig(ROFF_ARGS)
 
 	return(ROFF_IGN);
 }
-
-
-int
-roff_endparse(struct roff *r)
-{
-
-	if (NULL == r->last)
-		return(1);
-	return((*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
-				r->last->line, r->last->col, NULL));
-}
+#endif
diff --git a/roff.h b/roff.h
index 2e18011d..c28c05eb 100644
--- a/roff.h
+++ b/roff.h
@@ -1,4 +1,4 @@
-/*	$Id: roff.h,v 1.13 2010/05/15 18:35:14 kristaps Exp $ */
+/*	$Id: roff.h,v 1.14 2010/05/16 10:59:36 kristaps Exp $ */
 /*
  * Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -18,9 +18,10 @@
 #define ROFF_H
 
 enum	rofferr {
-	ROFF_CONT, /* re-process line with libmdoc or libman */
-	ROFF_IGN, /* ignore line */
-	ROFF_ERR, /* badness */
+	ROFF_CONT, /* continue processing line */
+	ROFF_RERUN, /* re-run roff interpreter with offset */
+	ROFF_IGN, /* ignore current line */
+	ROFF_ERR, /* badness: puke and stop */
 };
 
 __BEGIN_DECLS
@@ -30,7 +31,8 @@ struct	roff;
 void	 	  roff_free(struct roff *);
 struct	roff	 *roff_alloc(mandocmsg, void *);
 void		  roff_reset(struct roff *);
-enum	rofferr	  roff_parseln(struct roff *, int, char **, size_t *);
+enum	rofferr	  roff_parseln(struct roff *, int, 
+			char **, size_t *, int, int *);
 int		  roff_endparse(struct roff *);
 
 __END_DECLS