X-Git-Url: https://git.cameronkatri.com/mandoc.git/blobdiff_plain/d54afcd6206b4f4d7ffc18ab336cabe41c5bd6ab..b088e954af8efacd0953fb5fb903d2e434649ebf:/roff.c

diff --git a/roff.c b/roff.c
index 4e115f5f..0d845c7c 100644
--- a/roff.c
+++ b/roff.c
@@ -1,1373 +1,1093 @@
-/* $Id: roff.c,v 1.46 2008/12/06 19:41:41 kristaps Exp $ */
+/*	$Id: roff.c,v 1.94 2010/07/07 15:04:54 kristaps Exp $ */
 /*
- * Copyright (c) 2008 Kristaps Dzonsons <kristaps@kth.se>
+ * Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
+ * Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
  *
  * 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.
+ * 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.
+ * 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.
  */
-#include <sys/param.h>
-#include <sys/types.h>
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 
 #include <assert.h>
+#include <errno.h>
 #include <ctype.h>
-#include <err.h>
-#include <stdarg.h>
+#include <limits.h>
 #include <stdlib.h>
-#include <stdio.h>
 #include <string.h>
-#include <time.h>
+#include <stdio.h>
 
-#include "libmdocml.h"
-#include "private.h"
+#include "mandoc.h"
 #include "roff.h"
+#include "libmandoc.h"
 
-/* FIXME: First letters of quoted-text interpreted in rofffindtok. */
-/* FIXME: `No' not implemented. */
-/* TODO: warn if Pp occurs before/after Sh etc. (see mdoc.samples). */
-/* TODO: warn about "X section only" macros. */
-/* TODO: warn about empty lists. */
-/* TODO: (warn) some sections need specific elements. */
-/* TODO: (warn) NAME section has particular order. */
-/* TODO: unify empty-content tags a la <br />. */
-/* TODO: macros with a set number of arguments? */
-/* TODO: validate Dt macro arguments. */
-/* FIXME: Bl -diag supposed to ignore callable children. */
-/* FIXME: Nm has newline when used in NAME section. */
+#define	RSTACK_MAX	128
 
-struct	roffnode {
-	int		  tok;			/* Token id. */
-	struct roffnode	 *parent;		/* Parent (or NULL). */
-};
-
-struct	rofftree {
-	struct roffnode	 *last;			/* Last parsed node. */
-	char		 *cur;			/* Line start. */
-	struct tm	  tm;			/* `Dd' results. */
-	char		  name[64];		/* `Nm' results. */
-	char		  os[64];		/* `Os' results. */
-	char		  title[64];		/* `Dt' results. */
-	char		  section[64];		/* `Dt' results. */
-	char		  volume[64];		/* `Dt' results. */
-	int		  state;
-#define	ROFF_PRELUDE	 (1 << 1)		/* In roff prelude. */
-#define	ROFF_PRELUDE_Os	 (1 << 2)		/* `Os' is parsed. */
-#define	ROFF_PRELUDE_Dt	 (1 << 3)		/* `Dt' is parsed. */
-#define	ROFF_PRELUDE_Dd	 (1 << 4)		/* `Dd' is parsed. */
-#define	ROFF_BODY	 (1 << 5)		/* In roff body. */
-	struct roffcb	  cb;			/* Callbacks. */
-	void		 *arg;			/* Callbacks' arg. */
-};
+#define	ROFF_CTL(c) \
+	('.' == (c) || '\'' == (c))
 
-static	struct roffnode	 *roffnode_new(int, struct rofftree *);
-static	void		  roffnode_free(struct rofftree *);
-static	void		  roff_warn(const struct rofftree *, 
-				const char *, char *, ...);
-static	void		  roff_err(const struct rofftree *, 
-				const char *, char *, ...);
-static	int		  roffpurgepunct(struct rofftree *, char **);
-static	int		  roffscan(int, const int *);
-static	int		  rofffindtok(const char *);
-static	int		  rofffindarg(const char *);
-static	int		  rofffindcallable(const char *);
-static	int		  roffargs(const struct rofftree *,
-				int, char *, char **);
-static	int		  roffargok(int, int);
-static	int		  roffnextopt(const struct rofftree *,
-				int, char ***, char **);
-static	int		  roffparseopts(struct rofftree *, int, 
-				char ***, int *, char **);
-static	int		  roffcall(struct rofftree *, int, char **);
-static	int 		  roffparse(struct rofftree *, char *);
-static	int		  textparse(struct rofftree *, char *);
-static	int		  roffdata(struct rofftree *, int, char *);
-static	int		  roffspecial(struct rofftree *, int, 
-				const char *, size_t, char **);
-static	int		  roffsetname(struct rofftree *, char **);
-
-#ifdef __linux__ 
-extern	size_t		  strlcat(char *, const char *, size_t);
-extern	size_t		  strlcpy(char *, const char *, size_t);
-extern	int		  vsnprintf(char *, size_t, 
-				const char *, va_list);
-extern	char		 *strptime(const char *, const char *,
-				struct tm *);
+#if 1
+#define	ROFF_DEBUG(fmt, args...) \
+	do { /* Nothing. */ } while (/*CONSTCOND*/ 0)
+#else
+#define	ROFF_DEBUG(fmt, args...) \
+	do { fprintf(stderr, fmt , ##args); } while (/*CONSTCOND*/ 0)
 #endif
 
-int
-roff_free(struct rofftree *tree, int flush)
-{
-	int		 error, t;
-	struct roffnode	*n;
+enum	rofft {
+	ROFF_am,
+	ROFF_ami,
+	ROFF_am1,
+	ROFF_de,
+	ROFF_dei,
+	ROFF_de1,
+	ROFF_ds,
+	ROFF_el,
+	ROFF_ie,
+	ROFF_if,
+	ROFF_ig,
+	ROFF_rm,
+	ROFF_tr,
+	ROFF_cblock,
+	ROFF_ccond,
+	ROFF_nr,
+	ROFF_MAX
+};
+
+enum	roffrule {
+	ROFFRULE_ALLOW,
+	ROFFRULE_DENY
+};
 
-	error = 0;
 
-	if ( ! flush)
-		goto end;
+struct	roffstr {
+	char		*name; /* key of symbol */
+	char		*string; /* current value */
+	struct roffstr	*next; /* next in list */
+};
 
-	error = 1;
+struct	roff {
+	struct roffnode	*last; /* leaf of stack */
+	mandocmsg	 msg; /* err/warn/fatal messages */
+	void		*data; /* privdata for messages */
+	enum roffrule	 rstack[RSTACK_MAX]; /* stack of !`ie' rules */
+	int		 rstackpos; /* position in rstack */
+	struct regset	*regs; /* read/writable registers */
+	struct roffstr	*first_string;
+};
 
-	if (ROFF_PRELUDE & tree->state) {
-		roff_err(tree, NULL, "prelude never finished");
-		goto end;
-	} 
+struct	roffnode {
+	enum rofft	 tok; /* type of node */
+	struct roffnode	*parent; /* up one in stack */
+	int		 line; /* parse line */
+	int		 col; /* parse col */
+	char		*end; /* end-rules: custom token */
+	int		 endspan; /* end-rules: next-line or infty */
+	enum roffrule	 rule; /* current evaluation rule */
+};
 
-	for (n = tree->last; n; n = n->parent) {
-		if (0 != tokens[n->tok].ctx) 
-			continue;
-		roff_err(tree, NULL, "closing explicit scope `%s'", 
-				toknames[n->tok]);
-		goto end;
-	}
+#define	ROFF_ARGS	 struct roff *r, /* parse ctx */ \
+			 enum rofft tok, /* tok of macro */ \
+		 	 char **bufp, /* input buffer */ \
+			 size_t *szp, /* size of input buffer */ \
+			 int ln, /* parse line */ \
+			 int ppos, /* original pos in buffer */ \
+			 int pos, /* current pos in buffer */ \
+			 int *offs /* reset offset of buffer data */
+
+typedef	enum rofferr (*roffproc)(ROFF_ARGS);
+
+struct	roffmac {
+	const char	*name; /* macro name */
+	roffproc	 proc; /* process new macro */
+	roffproc	 text; /* process as child text of macro */
+	roffproc	 sub; /* process as child of macro */
+	int		 flags;
+#define	ROFFMAC_STRUCT	(1 << 0) /* always interpret */
+	struct roffmac	*next;
+};
 
-	while (tree->last) {
-		t = tree->last->tok;
-		if ( ! (*tokens[t].cb)(t, tree, NULL, ROFF_EXIT))
-			goto end;
-	}
+static	enum rofferr	 roff_block(ROFF_ARGS);
+static	enum rofferr	 roff_block_text(ROFF_ARGS);
+static	enum rofferr	 roff_block_sub(ROFF_ARGS);
+static	enum rofferr	 roff_cblock(ROFF_ARGS);
+static	enum rofferr	 roff_ccond(ROFF_ARGS);
+static	enum rofferr	 roff_cond(ROFF_ARGS);
+static	enum rofferr	 roff_cond_text(ROFF_ARGS);
+static	enum rofferr	 roff_cond_sub(ROFF_ARGS);
+static	enum rofferr	 roff_ds(ROFF_ARGS);
+static	enum roffrule	 roff_evalcond(const char *, int *);
+static	void		 roff_freestr(struct roff *);
+static	const char	*roff_getstrn(const struct roff *, 
+				const char *, size_t);
+static	enum rofferr	 roff_line(ROFF_ARGS);
+static	enum rofferr	 roff_nr(ROFF_ARGS);
+static	int		 roff_res(struct roff *, int, 
+				char **, size_t *, int, int *);
+static	void		 roff_setstr(struct roff *,
+				const char *, const char *);
+
+/* See roff_hash_find() */
+
+#define	ASCII_HI	 126
+#define	ASCII_LO	 33
+#define	HASHWIDTH	(ASCII_HI - ASCII_LO + 1)
+
+static	struct roffmac	*hash[HASHWIDTH];
+
+static	struct roffmac	 roffs[ROFF_MAX] = {
+	{ "am", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "ami", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "am1", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "de", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "dei", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "de1", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "ds", roff_ds, NULL, NULL, 0, NULL },
+	{ "el", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
+	{ "ie", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
+	{ "if", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
+	{ "ig", roff_block, roff_block_text, roff_block_sub, 0, NULL },
+	{ "rm", roff_line, NULL, NULL, 0, NULL },
+	{ "tr", roff_line, NULL, NULL, 0, NULL },
+	{ ".", roff_cblock, NULL, NULL, 0, NULL },
+	{ "\\}", roff_ccond, NULL, NULL, 0, NULL },
+	{ "nr", roff_nr, NULL, NULL, 0, NULL },
+};
 
-	if ( ! (*tree->cb.rofftail)(tree->arg))
-		goto end;
+static	void		 roff_free1(struct roff *);
+static	enum rofft	 roff_hash_find(const char *);
+static	void		 roff_hash_init(void);
+static	void		 roffnode_cleanscope(struct roff *);
+static	int		 roffnode_push(struct roff *, 
+				enum rofft, int, int);
+static	void		 roffnode_pop(struct roff *);
+static	enum rofft	 roff_parse(const char *, int *);
+static	int		 roff_parse_nat(const char *, unsigned int *);
 
-	error = 0;
+/* See roff_hash_find() */
+#define	ROFF_HASH(p)	(p[0] - ASCII_LO)
 
-end:
+static void
+roff_hash_init(void)
+{
+	struct roffmac	 *n;
+	int		  buc, i;
 
-	while (tree->last) 
-		roffnode_free(tree);
+	for (i = 0; i < (int)ROFF_MAX; i++) {
+		assert(roffs[i].name[0] >= ASCII_LO);
+		assert(roffs[i].name[0] <= ASCII_HI);
 
-	free(tree);
+		buc = ROFF_HASH(roffs[i].name);
 
-	return(error ? 0 : 1);
+		if (NULL != (n = hash[buc])) {
+			for ( ; n->next; n = n->next)
+				/* Do nothing. */ ;
+			n->next = &roffs[i];
+		} else
+			hash[buc] = &roffs[i];
+	}
 }
 
 
-struct rofftree *
-roff_alloc(const struct roffcb *cb, void *args)
+/*
+ * Look up a roff token by its name.  Returns ROFF_MAX if no macro by
+ * the nil-terminated string name could be found.
+ */
+static enum rofft
+roff_hash_find(const char *p)
 {
-	struct rofftree	*tree;
+	int		 buc;
+	struct roffmac	*n;
 
-	assert(args);
-	assert(cb);
+	/*
+	 * libroff has an extremely simple hashtable, for the time
+	 * being, which simply keys on the first character, which must
+	 * be printable, then walks a chain.  It works well enough until
+	 * optimised.
+	 */
 
-	if (NULL == (tree = calloc(1, sizeof(struct rofftree))))
-		err(1, "calloc");
+	if (p[0] < ASCII_LO || p[0] > ASCII_HI)
+		return(ROFF_MAX);
 
-	tree->state = ROFF_PRELUDE;
-	tree->arg = args;
+	buc = ROFF_HASH(p);
 
-	(void)memcpy(&tree->cb, cb, sizeof(struct roffcb));
+	if (NULL == (n = hash[buc]))
+		return(ROFF_MAX);
+	for ( ; n; n = n->next)
+		if (0 == strcmp(n->name, p))
+			return((enum rofft)(n - roffs));
 
-	return(tree);
+	return(ROFF_MAX);
 }
 
 
-int
-roff_engine(struct rofftree *tree, char *buf)
+/*
+ * Pop the current node off of the stack of roff instructions currently
+ * pending.
+ */
+static void
+roffnode_pop(struct roff *r)
 {
+	struct roffnode	*p;
 
-	tree->cur = buf;
-	assert(buf);
+	assert(r->last);
+	p = r->last; 
 
-	if (0 == *buf) {
-		roff_err(tree, buf, "blank line");
-		return(0);
-	} else if ('.' != *buf)
-		return(textparse(tree, buf));
+	if (ROFF_el == p->tok)
+		if (r->rstackpos > -1)
+			r->rstackpos--;
 
-	return(roffparse(tree, buf));
+	r->last = r->last->parent;
+	if (p->end)
+		free(p->end);
+	free(p);
 }
 
 
+/*
+ * Push a roff node onto the instruction stack.  This must later be
+ * removed with roffnode_pop().
+ */
 static int
-textparse(struct rofftree *tree, char *buf)
+roffnode_push(struct roff *r, enum rofft tok, int line, int col)
 {
-	char		*bufp;
-
-	/* TODO: literal parsing. */
+	struct roffnode	*p;
 
-	if ( ! (ROFF_BODY & tree->state)) {
-		roff_err(tree, buf, "data not in body");
+	if (NULL == (p = calloc(1, sizeof(struct roffnode)))) {
+		(*r->msg)(MANDOCERR_MEM, r->data, line, col, NULL);
 		return(0);
 	}
 
-	/* LINTED */
-	while (*buf) {
-		while (*buf && isspace(*buf))
-			buf++;
+	p->tok = tok;
+	p->parent = r->last;
+	p->line = line;
+	p->col = col;
+	p->rule = p->parent ? p->parent->rule : ROFFRULE_DENY;
 
-		if (0 == *buf)
-			break;
+	r->last = p;
+	return(1);
+}
 
-		bufp = buf++;
 
-		while (*buf && ! isspace(*buf))
-			buf++;
+static void
+roff_free1(struct roff *r)
+{
 
-		if (0 != *buf) {
-			*buf++ = 0;
-			if ( ! roffdata(tree, 1, bufp))
-				return(0);
-			continue;
-		}
+	while (r->last)
+		roffnode_pop(r);
+	roff_freestr(r);
+}
 
-		if ( ! roffdata(tree, 1, bufp))
-			return(0);
-		break;
-	}
 
-	return(1);
+void
+roff_reset(struct roff *r)
+{
+
+	roff_free1(r);
 }
 
 
-static int
-roffargs(const struct rofftree *tree, 
-		int tok, char *buf, char **argv)
+void
+roff_free(struct roff *r)
 {
-	int		 i;
-	char		*p;
 
-	assert(tok >= 0 && tok < ROFF_MAX);
-	assert('.' == *buf);
+	roff_free1(r);
+	free(r);
+}
 
-	p = buf;
 
-	/*
-	 * This is an ugly little loop.  It parses a line into
-	 * space-delimited tokens.  If a quote mark is encountered, a
-	 * token is alloted the entire quoted text.  If whitespace is
-	 * escaped, it's included in the prior alloted token.
-	 */
-
-	/* LINTED */
-	for (i = 0; *buf && i < ROFF_MAXLINEARG; i++) {
-		if ('\"' == *buf) {
-			argv[i] = ++buf;
-			while (*buf && '\"' != *buf)
-				buf++;
-			if (0 == *buf) {
-				roff_err(tree, argv[i], "unclosed "
-						"quote in argument "
-						"list for `%s'", 
-						toknames[tok]);
-				return(0);
-			}
-		} else { 
-			argv[i] = buf++;
-			while (*buf) {
-				if ( ! isspace(*buf)) {
-					buf++;
-					continue;
-				}
-				if (*(buf - 1) == '\\') {
-					buf++;
-					continue;
-				}
-				break;
-			}
-			if (0 == *buf)
-				continue;
-		}
-		*buf++ = 0;
-		while (*buf && isspace(*buf))
-			buf++;
-	}
+struct roff *
+roff_alloc(struct regset *regs, const mandocmsg msg, void *data)
+{
+	struct roff	*r;
 
-	assert(i > 0);
-	if (ROFF_MAXLINEARG == i && *buf) {
-		roff_err(tree, p, "too many arguments for `%s'", toknames
-				[tok]);
+	if (NULL == (r = calloc(1, sizeof(struct roff)))) {
+		(*msg)(MANDOCERR_MEM, data, 0, 0, NULL);
 		return(0);
 	}
 
-	argv[i] = NULL;
-	return(1);
+	r->regs = regs;
+	r->msg = msg;
+	r->data = data;
+	r->rstackpos = -1;
+	
+	roff_hash_init();
+	return(r);
 }
 
 
+/*
+ * Pre-filter each and every line for reserved words (one beginning with
+ * `\*', e.g., `\*(ab').  These must be handled before the actual line
+ * is processed. 
+ */
 static int
-roffscan(int tok, const int *tokv)
+roff_res(struct roff *r, int ln, char **bufp,
+		size_t *szp, int pos, int *offs)
 {
+	const char	*cp, *cpp, *st, *res;
+	int		 i, maxl;
+	size_t		 nsz;
+	char		*n;
+
+	for (cp = &(*bufp)[pos]; (cpp = strstr(cp, "\\*")); cp++) {
+		cp = cpp + 2;
+		switch (*cp) {
+		case ('('):
+			cp++;
+			maxl = 2;
+			break;
+		case ('['):
+			cp++;
+			maxl = 0;
+			break;
+		default:
+			maxl = 1;
+			break;
+		}
 
-	if (NULL == tokv)
-		return(1);
-
-	for ( ; ROFF_MAX != *tokv; tokv++) 
-		if (tok == *tokv)
-			return(1);
+		st = cp;
 
-	return(0);
-}
+		for (i = 0; 0 == maxl || i < maxl; i++, cp++) {
+			if ('\0' == *cp)
+				return(1); /* Error. */
+			if (0 == maxl && ']' == *cp)
+				break;
+		}
 
+		res = roff_getstrn(r, st, (size_t)i);
 
-static int
-roffparse(struct rofftree *tree, char *buf)
-{
-	int		  tok, t;
-	struct roffnode	 *n;
-	char		 *argv[ROFF_MAXLINEARG];
-	char		**argvp;
+		if (NULL == res) {
+			cp -= maxl ? 1 : 0;
+			continue;
+		}
 
-	if (0 != *buf && 0 != *(buf + 1) && 0 != *(buf + 2))
-		if (0 == strncmp(buf, ".\\\"", 3))
-			return(1);
+		ROFF_DEBUG("roff: splicing reserved: [%.*s]\n", i, st);
 
-	if (ROFF_MAX == (tok = rofffindtok(buf + 1))) {
-		roff_err(tree, buf + 1, "bogus line macro");
-		return(0);
-	} else if (NULL == tokens[tok].cb) {
-		roff_err(tree, buf + 1, "unsupported macro `%s'", 
-				toknames[tok]);
-		return(0);
-	}
+		nsz = *szp + strlen(res) + 1;
+		n = mandoc_malloc(nsz);
 
-	assert(ROFF___ != tok);
-	if ( ! roffargs(tree, tok, buf, argv)) 
-		return(0);
+		*n = '\0';
 
-	argvp = (char **)argv;
+		strlcat(n, *bufp, (size_t)(cpp - *bufp + 1));
+		strlcat(n, res, nsz);
+		strlcat(n, cp + (maxl ? 0 : 1), nsz);
 
-	/* 
-	 * Prelude macros break some assumptions, so branch now. 
-	 */
-	
-	if (ROFF_PRELUDE & tree->state) {
-		assert(NULL == tree->last);
-		return((*tokens[tok].cb)(tok, tree, argvp, ROFF_ENTER));
-	} 
+		free(*bufp);
 
-	assert(ROFF_BODY & tree->state);
+		*bufp = n;
+		*szp = nsz;
+		return(0);
+	}
 
-	/* 
-	 * First check that our possible parents and parent's possible
-	 * children are satisfied.  
-	 */
+	return(1);
+}
 
-	if (tree->last && ! roffscan
-			(tree->last->tok, tokens[tok].parents)) {
-		roff_err(tree, *argvp, "`%s' has invalid parent `%s'",
-				toknames[tok], 
-				toknames[tree->last->tok]);
-		return(0);
-	} 
 
-	if (tree->last && ! roffscan
-			(tok, tokens[tree->last->tok].children)) {
-		roff_err(tree, *argvp, "`%s' is invalid child of `%s'",
-				toknames[tok],
-				toknames[tree->last->tok]);
-		return(0);
-	}
+enum rofferr
+roff_parseln(struct roff *r, int ln, char **bufp, 
+		size_t *szp, int pos, int *offs)
+{
+	enum rofft	 t;
+	int		 ppos;
 
 	/*
-	 * Branch if we're not a layout token.
+	 * Run the reserved-word filter only if we have some reserved
+	 * words to fill in.
 	 */
 
-	if (ROFF_LAYOUT != tokens[tok].type)
-		return((*tokens[tok].cb)(tok, tree, argvp, ROFF_ENTER));
-	if (0 == tokens[tok].ctx)
-		return((*tokens[tok].cb)(tok, tree, argvp, ROFF_ENTER));
+	if (r->first_string && ! roff_res(r, ln, bufp, szp, pos, offs))
+		return(ROFF_RERUN);
 
 	/*
-	 * First consider implicit-end tags, like as follows:
-	 *	.Sh SECTION 1
-	 *	.Sh SECTION 2
-	 * In this, we want to close the scope of the NAME section.  If
-	 * there's an intermediary implicit-end tag, such as
-	 *	.Sh SECTION 1
-	 *	.Ss Subsection 1
-	 *	.Sh SECTION 2
-	 * then it must be closed as well.
+	 * First, if a scope is open and we're not a macro, pass the
+	 * text through the macro's filter.  If a scope isn't open and
+	 * we're not a macro, just let it through.
 	 */
 
-	if (tok == tokens[tok].ctx) {
-		/* 
-		 * First search up to the point where we must close.
-		 * If one doesn't exist, then we can open a new scope.
-		 */
-
-		for (n = tree->last; n; n = n->parent) {
-			assert(0 == tokens[n->tok].ctx ||
-					n->tok == tokens[n->tok].ctx);
-			if (n->tok == tok)
-				break;
-			if (ROFF_SHALLOW & tokens[tok].flags) {
-				n = NULL;
-				break;
-			}
-			if (tokens[n->tok].ctx == n->tok)
-				continue;
-			roff_err(tree, *argv, "`%s' breaks `%s' scope",
-					toknames[tok], toknames[n->tok]);
-			return(0);
-		}
-
-		/*
-		 * Create a new scope, as no previous one exists to
-		 * close out.
-		 */
-
-		if (NULL == n)
-			return((*tokens[tok].cb)(tok, tree, argvp, ROFF_ENTER));
+	if (r->last && ! ROFF_CTL((*bufp)[pos])) {
+		t = r->last->tok;
+		assert(roffs[t].text);
+		ROFF_DEBUG("roff: intercept scoped text: %s, [%s]\n", 
+				roffs[t].name, &(*bufp)[pos]);
+		return((*roffs[t].text)
+				(r, t, bufp, szp, 
+				 ln, pos, pos, offs));
+	} else if ( ! ROFF_CTL((*bufp)[pos]))
+		return(ROFF_CONT);
 
-		/* 
-		 * Close out all intermediary scoped blocks, then hang
-		 * the current scope from our predecessor's parent.
-		 */
-
-		do {
-			t = tree->last->tok;
-			if ( ! (*tokens[t].cb)(t, tree, NULL, ROFF_EXIT))
-				return(0);
-		} while (t != tok);
+	/*
+	 * If a scope is open, go to the child handler for that macro,
+	 * as it may want to preprocess before doing anything with it.
+	 */
 
-		return((*tokens[tok].cb)(tok, tree, argvp, ROFF_ENTER));
+	if (r->last) {
+		t = r->last->tok;
+		assert(roffs[t].sub);
+		ROFF_DEBUG("roff: intercept scoped context: %s\n", 
+				roffs[t].name);
+		return((*roffs[t].sub)
+				(r, t, bufp, szp, 
+				 ln, pos, pos, offs));
 	}
 
 	/*
-	 * Now consider explicit-end tags, where we want to close back
-	 * to a specific tag.  Example:
-	 * 	.Bl
-	 * 	.It Item.
-	 * 	.El
-	 * In this, the `El' tag closes out the scope of `Bl'.
+	 * Lastly, as we've no scope open, try to look up and execute
+	 * the new macro.  If no macro is found, simply return and let
+	 * the compilers handle it.
 	 */
 
-	assert(tok != tokens[tok].ctx && 0 != tokens[tok].ctx);
-
-	/* LINTED */
-	for (n = tree->last; n; n = n->parent)
-		if (n->tok != tokens[tok].ctx) {
-			if (n->tok == tokens[n->tok].ctx)
-				continue;
-			roff_err(tree, *argv, "`%s' breaks `%s' scope",
-					toknames[tok], toknames[n->tok]);
-			return(0);
-		} else
-			break;
+	ppos = pos;
+	if (ROFF_MAX == (t = roff_parse(*bufp, &pos)))
+		return(ROFF_CONT);
 
+	ROFF_DEBUG("roff: intercept new-scope: %s, [%s]\n", 
+			roffs[t].name, &(*bufp)[pos]);
+	assert(roffs[t].proc);
+	return((*roffs[t].proc)
+			(r, t, bufp, szp, 
+			 ln, ppos, pos, offs));
+}
 
-	if (NULL == n) {
-		roff_err(tree, *argv, "`%s' has no starting tag `%s'",
-				toknames[tok], 
-				toknames[tokens[tok].ctx]);
-		return(0);
-	}
 
-	/* LINTED */
-	do {
-		t = tree->last->tok;
-		if ( ! (*tokens[t].cb)(t, tree, NULL, ROFF_EXIT))
-			return(0);
-	} while (t != tokens[tok].ctx);
+int
+roff_endparse(struct roff *r)
+{
 
-	return(1);
+	if (NULL == r->last)
+		return(1);
+	return((*r->msg)(MANDOCERR_SCOPEEXIT, r->data, r->last->line, 
+				r->last->col, NULL));
 }
 
 
-static int
-rofffindarg(const char *name)
+/*
+ * Parse a roff node's type from the input buffer.  This must be in the
+ * form of ".foo xxx" in the usual way.
+ */
+static enum rofft
+roff_parse(const char *buf, int *pos)
 {
-	size_t		 i;
-
-	/* FIXME: use a table, this is slow but ok for now. */
+	int		 j;
+	char		 mac[5];
+	enum rofft	 t;
 
-	/* LINTED */
-	for (i = 0; i < ROFF_ARGMAX; i++)
-		/* LINTED */
-		if (0 == strcmp(name, tokargnames[i]))
-			return((int)i);
-	
-	return(ROFF_ARGMAX);
-}
+	assert(ROFF_CTL(buf[*pos]));
+	(*pos)++;
 
+	while (buf[*pos] && (' ' == buf[*pos] || '\t' == buf[*pos]))
+		(*pos)++;
 
-static int
-rofffindtok(const char *buf)
-{
-	char		 token[4];
-	int		 i;
+	if ('\0' == buf[*pos])
+		return(ROFF_MAX);
 
-	for (i = 0; *buf && ! isspace(*buf) && i < 3; i++, buf++)
-		token[i] = *buf;
+	for (j = 0; j < 4; j++, (*pos)++)
+		if ('\0' == (mac[j] = buf[*pos]))
+			break;
+		else if (' ' == buf[*pos] || (j && '\\' == buf[*pos]))
+			break;
 
-	if (i == 3) 
+	if (j == 4 || j < 1)
 		return(ROFF_MAX);
 
-	token[i] = 0;
+	mac[j] = '\0';
 
-	/* FIXME: use a table, this is slow but ok for now. */
+	if (ROFF_MAX == (t = roff_hash_find(mac)))
+		return(t);
 
-	/* LINTED */
-	for (i = 0; i < ROFF_MAX; i++)
-		/* LINTED */
-		if (0 == strcmp(toknames[i], token))
-			return((int)i);
+	while (buf[*pos] && ' ' == buf[*pos])
+		(*pos)++;
 
-	return(ROFF_MAX);
+	return(t);
 }
 
 
 static int
-roffispunct(const char *p)
+roff_parse_nat(const char *buf, unsigned int *res)
 {
+	char		*ep;
+	long		 lval;
 
-	if (0 == *p)
+	errno = 0;
+	lval = strtol(buf, &ep, 10);
+	if (buf[0] == '\0' || *ep != '\0')
 		return(0);
-	if (0 != *(p + 1))
+	if ((errno == ERANGE && 
+			(lval == LONG_MAX || lval == LONG_MIN)) ||
+			(lval > INT_MAX || lval < 0))
 		return(0);
 
-	switch (*p) {
-	case('{'):
-		/* FALLTHROUGH */
-	case('.'):
-		/* FALLTHROUGH */
-	case(','):
-		/* FALLTHROUGH */
-	case(';'):
-		/* FALLTHROUGH */
-	case(':'):
-		/* FALLTHROUGH */
-	case('?'):
+	*res = (unsigned int)lval;
+	return(1);
+}
+
+
+/* ARGSUSED */
+static enum rofferr
+roff_cblock(ROFF_ARGS)
+{
+
+	/*
+	 * A block-close `..' should only be invoked as a child of an
+	 * ignore macro, otherwise raise a warning and just ignore it.
+	 */
+
+	if (NULL == r->last) {
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	}
+
+	switch (r->last->tok) {
+	case (ROFF_am):
 		/* FALLTHROUGH */
-	case('!'):
+	case (ROFF_ami):
 		/* FALLTHROUGH */
-	case('('):
+	case (ROFF_am1):
 		/* FALLTHROUGH */
-	case(')'):
+	case (ROFF_de):
 		/* FALLTHROUGH */
-	case('['):
+	case (ROFF_dei):
 		/* FALLTHROUGH */
-	case(']'):
+	case (ROFF_de1):
 		/* FALLTHROUGH */
-	case('}'):
-		return(1);
-	default:
+	case (ROFF_ig):
 		break;
+	default:
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
 	}
 
-	return(0);
-}
-
-
-static int
-rofffindcallable(const char *name)
-{
-	int		 c;
-
-	if (ROFF_MAX == (c = rofffindtok(name)))
-		return(ROFF_MAX);
-	assert(c >= 0 && c < ROFF_MAX);
-	return(ROFF_CALLABLE & tokens[c].flags ? c : ROFF_MAX);
-}
-
-
-static struct roffnode *
-roffnode_new(int tokid, struct rofftree *tree)
-{
-	struct roffnode	*p;
-	
-	if (NULL == (p = malloc(sizeof(struct roffnode))))
-		err(1, "malloc");
-
-	p->tok = tokid;
-	p->parent = tree->last;
-	tree->last = p;
+	if ((*bufp)[pos])
+		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, pos, NULL))
+			return(ROFF_ERR);
 
-	return(p);
-}
+	roffnode_pop(r);
+	roffnode_cleanscope(r);
+	return(ROFF_IGN);
 
-
-static int
-roffargok(int tokid, int argid)
-{
-	const int	*c;
-
-	if (NULL == (c = tokens[tokid].args))
-		return(0);
-
-	for ( ; ROFF_ARGMAX != *c; c++) 
-		if (argid == *c)
-			return(1);
-
-	return(0);
 }
 
 
 static void
-roffnode_free(struct rofftree *tree)
+roffnode_cleanscope(struct roff *r)
 {
-	struct roffnode	*p;
-
-	assert(tree->last);
 
-	p = tree->last;
-	tree->last = tree->last->parent;
-	free(p);
+	while (r->last) {
+		if (--r->last->endspan < 0)
+			break;
+		roffnode_pop(r);
+	}
 }
 
 
-static int
-roffspecial(struct rofftree *tree, int tok, 
-		const char *start, size_t sz, char **ordp)
+/* ARGSUSED */
+static enum rofferr
+roff_ccond(ROFF_ARGS)
 {
 
-	switch (tok) {
-	case (ROFF_At):
-		if (0 == sz)
-			break;
-		if (0 == strcmp(*ordp, "v6"))
-			break;
-		else if (0 == strcmp(*ordp, "v7")) 
-			break;
-		else if (0 == strcmp(*ordp, "32v"))
-			break;
-		else if (0 == strcmp(*ordp, "V.1"))
-			break;
-		else if (0 == strcmp(*ordp, "V.4"))
-			break;
-		roff_err(tree, start, "invalid `At' arg");
-		return(0);
-
-	case (ROFF_Nm):
-		if (0 == sz) {
-			if (0 == tree->name[0]) {
-				roff_err(tree, start, "`Nm' not set");
-				return(0);
-			}
-			ordp[0] = tree->name;
-			ordp[1] = NULL;
-		} else if ( ! roffsetname(tree, ordp))
-			return(0);
-		break;
-
-	case (ROFF_Sx):
-		/* FALLTHROUGH*/
-	case (ROFF_Ex):
-		if (1 != sz) {
-			roff_err(tree, start, "`%s' expects one arg",
-					toknames[tok]);
-			return(0);
-		}
-		break;
+	if (NULL == r->last) {
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	}
 
-	case (ROFF_Sm):
-		if (1 != sz) {
-			roff_err(tree, start, "`Sm' expects one arg");
-			return(0);
-		} 
-		
-		if (0 != strcmp(ordp[0], "on") &&
-				0 != strcmp(ordp[0], "off")) {
-			roff_err(tree, start, "`Sm' has invalid argument");
-			return(0);
-		}
-		break;
-	
-	case (ROFF_Ud):
+	switch (r->last->tok) {
+	case (ROFF_el):
 		/* FALLTHROUGH */
-	case (ROFF_Ux):
+	case (ROFF_ie):
 		/* FALLTHROUGH */
-	case (ROFF_Bt):
-		if (0 != sz) {
-			roff_err(tree, start, "`%s' expects no args",
-					toknames[tok]);
-			return(0);
-		}
+	case (ROFF_if):
 		break;
 	default:
-		break;
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
 	}
 
-	return((*tree->cb.roffspecial)
-			(tree->arg, tok, tree->cur, ordp));
-}
-
+	if (r->last->endspan > -1) {
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	}
 
-static int
-roffcall(struct rofftree *tree, int tok, char **argv)
-{
+	if ((*bufp)[pos])
+		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, pos, NULL))
+			return(ROFF_ERR);
 
-	if (NULL == tokens[tok].cb) {
-		roff_err(tree, *argv, "unsupported macro `%s'", 
-				toknames[tok]);
-		return(0);
-	}
-	if ( ! (*tokens[tok].cb)(tok, tree, argv, ROFF_ENTER))
-		return(0);
-	return(1);
+	roffnode_pop(r);
+	roffnode_cleanscope(r);
+	return(ROFF_IGN);
 }
 
 
-static int
-roffnextopt(const struct rofftree *tree, int tok, 
-		char ***in, char **val)
+/* ARGSUSED */
+static enum rofferr
+roff_block(ROFF_ARGS)
 {
-	char		*arg, **argv;
-	int		 v;
-
-	*val = NULL;
-	argv = *in;
-	assert(argv);
-
-	if (NULL == (arg = *argv))
-		return(-1);
-	if ('-' != *arg)
-		return(-1);
-
-	if (ROFF_ARGMAX == (v = rofffindarg(arg + 1))) {
-		roff_warn(tree, arg, "argument-like parameter `%s' to "
-				"`%s'", arg, toknames[tok]);
-		return(-1);
-	} 
-	
-	if ( ! roffargok(tok, v)) {
-		roff_warn(tree, arg, "invalid argument parameter `%s' to "
-				"`%s'", tokargnames[v], toknames[tok]);
-		return(-1);
-	} 
-	
-	if ( ! (ROFF_VALUE & tokenargs[v]))
-		return(v);
-
-	*in = ++argv;
-
-	if (NULL == *argv) {
-		roff_err(tree, arg, "empty value of `%s' for `%s'",
-				tokargnames[v], toknames[tok]);
-		return(ROFF_ARGMAX);
+	int		sv;
+	size_t		sz;
+
+	if (ROFF_ig != tok && '\0' == (*bufp)[pos]) {
+		if ( ! (*r->msg)(MANDOCERR_NOARGS, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	} else if (ROFF_ig != tok) {
+		while ((*bufp)[pos] && ' ' != (*bufp)[pos])
+			pos++;
+		while (' ' == (*bufp)[pos])
+			pos++;
 	}
 
-	return(v);
-}
-
+	if ( ! roffnode_push(r, tok, ln, ppos))
+		return(ROFF_ERR);
 
-static int
-roffpurgepunct(struct rofftree *tree, char **argv)
-{
-	int		 i;
+	if ('\0' == (*bufp)[pos])
+		return(ROFF_IGN);
 
-	i = 0;
-	while (argv[i])
-		i++;
-	assert(i > 0);
-	if ( ! roffispunct(argv[--i]))
-		return(1);
-	while (i >= 0 && roffispunct(argv[i]))
-		i--;
-	i++;
-
-	/* LINTED */
-	while (argv[i])
-		if ( ! roffdata(tree, 0, argv[i++]))
-			return(0);
-	return(1);
-}
+	sv = pos;
+	while ((*bufp)[pos] && ' ' != (*bufp)[pos] && 
+			'\t' != (*bufp)[pos])
+		pos++;
 
+	/*
+	 * Note: groff does NOT like escape characters in the input.
+	 * Instead of detecting this, we're just going to let it fly and
+	 * to hell with it.
+	 */
 
-static int
-roffparseopts(struct rofftree *tree, int tok, 
-		char ***args, int *argc, char **argv)
-{
-	int		 i, c;
-	char		*v;
+	assert(pos > sv);
+	sz = (size_t)(pos - sv);
 
-	i = 0;
+	if (1 == sz && '.' == (*bufp)[sv])
+		return(ROFF_IGN);
 
-	while (-1 != (c = roffnextopt(tree, tok, args, &v))) {
-		if (ROFF_ARGMAX == c) 
-			return(0);
+	r->last->end = malloc(sz + 1);
 
-		argc[i] = c;
-		argv[i] = v;
-		i++;
-		*args = *args + 1;
+	if (NULL == r->last->end) {
+		(*r->msg)(MANDOCERR_MEM, r->data, ln, pos, NULL);
+		return(ROFF_ERR);
 	}
 
-	argc[i] = ROFF_ARGMAX;
-	argv[i] = NULL;
-	return(1);
-}
-
+	memcpy(r->last->end, *bufp + sv, sz);
+	r->last->end[(int)sz] = '\0';
 
-static int
-roffdata(struct rofftree *tree, int space, char *buf)
-{
+	if ((*bufp)[pos])
+		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, pos, NULL))
+			return(ROFF_ERR);
 
-	if (0 == *buf)
-		return(1);
-	return((*tree->cb.roffdata)(tree->arg, 
-				space != 0, tree->cur, buf));
+	return(ROFF_IGN);
 }
 
 
 /* ARGSUSED */
-static	int
-roff_Dd(ROFFCALL_ARGS)
+static enum rofferr
+roff_block_sub(ROFF_ARGS)
 {
-	time_t		 t;
-	char		*p, buf[32];
-
-	if (ROFF_BODY & tree->state) {
-		assert( ! (ROFF_PRELUDE & tree->state));
-		assert(ROFF_PRELUDE_Dd & tree->state);
-		return(roff_text(tok, tree, argv, type));
-	}
-
-	assert(ROFF_PRELUDE & tree->state);
-	assert( ! (ROFF_BODY & tree->state));
+	enum rofft	t;
+	int		i, j;
 
-	if (ROFF_PRELUDE_Dd & tree->state) {
-		roff_err(tree, *argv, "repeated `Dd' in prelude");
-		return(0);
-	} else if (ROFF_PRELUDE_Dt & tree->state) {
-		roff_err(tree, *argv, "out-of-order `Dd' in prelude");
-		return(0);
-	}
+	/*
+	 * First check whether a custom macro exists at this level.  If
+	 * it does, then check against it.  This is some of groff's
+	 * stranger behaviours.  If we encountered a custom end-scope
+	 * tag and that tag also happens to be a "real" macro, then we
+	 * need to try interpreting it again as a real macro.  If it's
+	 * not, then return ignore.  Else continue.
+	 */
 
-	assert(NULL == tree->last);
+	if (r->last->end) {
+		i = pos + 1;
+		while (' ' == (*bufp)[i] || '\t' == (*bufp)[i])
+			i++;
 
-	argv++;
+		for (j = 0; r->last->end[j]; j++, i++)
+			if ((*bufp)[i] != r->last->end[j])
+				break;
 
-	if (0 == strcmp(*argv, "$Mdocdate: December 6 2008 $")) {
-		t = time(NULL);
-		if (NULL == localtime_r(&t, &tree->tm))
-			err(1, "localtime_r");
-		tree->state |= ROFF_PRELUDE_Dd;
-		return(1);
-	} 
+		if ('\0' == r->last->end[j] && 
+				('\0' == (*bufp)[i] ||
+				 ' ' == (*bufp)[i] ||
+				 '\t' == (*bufp)[i])) {
+			roffnode_pop(r);
+			roffnode_cleanscope(r);
 
-	/* Build this from Mdocdate or raw date. */
-	
-	buf[0] = 0;
-	p = *argv;
-
-	if (0 != strcmp(*argv, "$Mdocdate:")) {
-		while (*argv) {
-			if (strlcat(buf, *argv++, sizeof(buf))
-					< sizeof(buf)) 
-				continue;
-			roff_err(tree, p, "bad `Dd' date");
-			return(0);
+			if (ROFF_MAX != roff_parse(*bufp, &pos))
+				return(ROFF_RERUN);
+			return(ROFF_IGN);
 		}
-		if (strptime(buf, "%b%d,%Y", &tree->tm)) {
-			tree->state |= ROFF_PRELUDE_Dd;
-			return(1);
-		}
-		roff_err(tree, *argv, "bad `Dd' date");
-		return(0);
 	}
 
-	argv++;
-	while (*argv && **argv != '$') {
-		if (strlcat(buf, *argv++, sizeof(buf))
-				>= sizeof(buf)) {
-			roff_err(tree, p, "bad `Dd' Mdocdate");
-			return(0);
-		} 
-		if (strlcat(buf, " ", sizeof(buf))
-				>= sizeof(buf)) {
-			roff_err(tree, p, "bad `Dd' Mdocdate");
-			return(0);
-		}
-	}
-	if (NULL == *argv) {
-		roff_err(tree, p, "bad `Dd' Mdocdate");
-		return(0);
-	}
+	/*
+	 * If we have no custom end-query or lookup failed, then try
+	 * pulling it out of the hashtable.
+	 */
 
-	if (NULL == strptime(buf, "%b %d %Y", &tree->tm)) {
-		roff_err(tree, *argv, "bad `Dd' Mdocdate");
-		return(0);
-	}
+	ppos = pos;
+	t = roff_parse(*bufp, &pos);
 
-	tree->state |= ROFF_PRELUDE_Dd;
-	return(1);
+	/* If we're not a comment-end, then throw it away. */
+	if (ROFF_cblock != t)
+		return(ROFF_IGN);
+
+	assert(roffs[t].proc);
+	return((*roffs[t].proc)(r, t, bufp, szp, 
+				ln, ppos, pos, offs));
 }
 
 
 /* ARGSUSED */
-static	int
-roff_Dt(ROFFCALL_ARGS)
+static enum rofferr
+roff_block_text(ROFF_ARGS)
 {
 
-	if (ROFF_BODY & tree->state) {
-		assert( ! (ROFF_PRELUDE & tree->state));
-		assert(ROFF_PRELUDE_Dt & tree->state);
-		return(roff_text(tok, tree, argv, type));
-	}
-
-	assert(ROFF_PRELUDE & tree->state);
-	assert( ! (ROFF_BODY & tree->state));
-
-	if ( ! (ROFF_PRELUDE_Dd & tree->state)) {
-		roff_err(tree, *argv, "out-of-order `Dt' in prelude");
-		return(0);
-	} else if (ROFF_PRELUDE_Dt & tree->state) {
-		roff_err(tree, *argv, "repeated `Dt' in prelude");
-		return(0);
-	}
-
-	argv++;
-	if (NULL == *argv) {
-		roff_err(tree, *argv, "`Dt' needs document title");
-		return(0);
-	} else if (strlcpy(tree->title, *argv, sizeof(tree->title))
-			>= sizeof(tree->title)) {
-		roff_err(tree, *argv, "`Dt' document title too long");
-		return(0);
-	}
+	return(ROFF_IGN);
+}
 
-	argv++;
-	if (NULL == *argv) {
-		roff_err(tree, *argv, "`Dt' needs section");
-		return(0);
-	} else if (strlcpy(tree->section, *argv, sizeof(tree->section))
-			>= sizeof(tree->section)) {
-		roff_err(tree, *argv, "`Dt' section too long");
-		return(0);
-	}
 
-	argv++;
-	if (NULL == *argv) {
-		tree->volume[0] = 0;
-	} else if (strlcpy(tree->volume, *argv, sizeof(tree->volume))
-			>= sizeof(tree->volume)) {
-		roff_err(tree, *argv, "`Dt' volume too long");
-		return(0);
-	}
+/* ARGSUSED */
+static enum rofferr
+roff_cond_sub(ROFF_ARGS)
+{
+	enum rofft	 t;
+	enum roffrule	 rr;
+	struct roffnode	*l;
 
-	assert(NULL == tree->last);
-	tree->state |= ROFF_PRELUDE_Dt;
+	ppos = pos;
+	rr = r->last->rule;
 
-	return(1);
-}
+	/* 
+	 * Clean out scope.  If we've closed ourselves, then don't
+	 * continue. 
+	 */
 
+	l = r->last;
+	roffnode_cleanscope(r);
 
-static int
-roffsetname(struct rofftree *tree, char **ordp)
-{
-	
-	assert(*ordp);
+	if (l != r->last)
+		return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
 
-	/* FIXME: not all sections can set this. */
+	if (ROFF_MAX == (t = roff_parse(*bufp, &pos)))
+		return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
 
-	if (NULL != *(ordp + 1)) {
-		roff_err(tree, *ordp, "too many `Nm' args");
-		return(0);
-	} 
-	
-	if (strlcpy(tree->name, *ordp, sizeof(tree->name)) 
-			>= sizeof(tree->name)) {
-		roff_err(tree, *ordp, "`Nm' arg too long");
-		return(0);
-	}
-
-	return(1);
+	/*
+	 * A denied conditional must evaluate its children if and only
+	 * if they're either structurally required (such as loops and
+	 * conditionals) or a closing macro.
+	 */
+	if (ROFFRULE_DENY == rr)
+		if ( ! (ROFFMAC_STRUCT & roffs[t].flags))
+			if (ROFF_ccond != t)
+				return(ROFF_IGN);
+
+	assert(roffs[t].proc);
+	return((*roffs[t].proc)(r, t, bufp, szp, 
+				ln, ppos, pos, offs));
 }
 
 
 /* ARGSUSED */
-static	int
-roff_Ns(ROFFCALL_ARGS)
+static enum rofferr
+roff_cond_text(ROFF_ARGS)
 {
-	int		 j, c, first;
-	char		*morep[1];
-
-	first = (*argv++ == tree->cur);
-	morep[0] = NULL;
-
-	if ( ! roffspecial(tree, tok, *argv, 0, morep))
-		return(0);
+	char		*ep, *st;
+	enum roffrule	 rr;
 
-	while (*argv) {
-		if (ROFF_MAX != (c = rofffindcallable(*argv))) {
-			if ( ! roffcall(tree, c, argv))
-				return(0);
-			break;
-		}
+	rr = r->last->rule;
 
-		if ( ! roffispunct(*argv)) {
-			if ( ! roffdata(tree, 1, *argv++))
-				return(0);
-			continue;
-		}
-
-		for (j = 0; argv[j]; j++)
-			if ( ! roffispunct(argv[j]))
-				break;
-
-		if (argv[j]) {
-			if ( ! roffdata(tree, 0, *argv++))
-				return(0);
-			continue;
-		}
+	/*
+	 * We display the value of the text if out current evaluation
+	 * scope permits us to do so.
+	 */
 
-		break;
+	st = &(*bufp)[pos];
+	if (NULL == (ep = strstr(st, "\\}"))) {
+		roffnode_cleanscope(r);
+		return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
 	}
 
-	if ( ! first)
-		return(1);
+	if (ep == st || (ep > st && '\\' != *(ep - 1)))
+		roffnode_pop(r);
 
-	return(roffpurgepunct(tree, argv));
+	roffnode_cleanscope(r);
+	return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
 }
 
 
-/* ARGSUSED */
-static	int
-roff_Os(ROFFCALL_ARGS)
+static enum roffrule
+roff_evalcond(const char *v, int *pos)
 {
-	char		*p;
 
-	if (ROFF_BODY & tree->state) {
-		assert( ! (ROFF_PRELUDE & tree->state));
-		assert(ROFF_PRELUDE_Os & tree->state);
-		return(roff_text(tok, tree, argv, type));
-	}
-
-	assert(ROFF_PRELUDE & tree->state);
-	if ( ! (ROFF_PRELUDE_Dt & tree->state) ||
-			! (ROFF_PRELUDE_Dd & tree->state)) {
-		roff_err(tree, *argv, "out-of-order `Os' in prelude");
-		return(0);
-	}
-
-	tree->os[0] = 0;
-
-	p = *++argv;
-
-	while (*argv) {
-		if (strlcat(tree->os, *argv++, sizeof(tree->os))
-				< sizeof(tree->os)) 
-			continue;
-		roff_err(tree, p, "`Os' value too long");
-		return(0);
+	switch (v[*pos]) {
+	case ('n'):
+		(*pos)++;
+		return(ROFFRULE_ALLOW);
+	case ('e'):
+		/* FALLTHROUGH */
+	case ('o'):
+		/* FALLTHROUGH */
+	case ('t'):
+		(*pos)++;
+		return(ROFFRULE_DENY);
+	default:
+		break;
 	}
 
-	if (0 == tree->os[0])
-		if (strlcpy(tree->os, "LOCAL", sizeof(tree->os))
-				>= sizeof(tree->os)) {
-			roff_err(tree, p, "`Os' value too long");
-			return(0);
-		}
+	while (v[*pos] && ' ' != v[*pos])
+		(*pos)++;
+	return(ROFFRULE_DENY);
+}
 
-	tree->state |= ROFF_PRELUDE_Os;
-	tree->state &= ~ROFF_PRELUDE;
-	tree->state |= ROFF_BODY;
 
-	assert(NULL == tree->last);
+/* ARGSUSED */
+static enum rofferr
+roff_line(ROFF_ARGS)
+{
 
-	return((*tree->cb.roffhead)(tree->arg, &tree->tm,
-				tree->os, tree->title, tree->section,
-				tree->volume));
+	return(ROFF_IGN);
 }
 
 
 /* ARGSUSED */
-static int
-roff_layout(ROFFCALL_ARGS) 
+static enum rofferr
+roff_cond(ROFF_ARGS)
 {
-	int		 i, c, argcp[ROFF_MAXLINEARG];
-	char		*argvp[ROFF_MAXLINEARG];
+	int		 sv;
+	enum roffrule	 rule;
 
-	if (ROFF_PRELUDE & tree->state) {
-		roff_err(tree, *argv, "bad `%s' in prelude", 
-				toknames[tok]);
-		return(0);
-	} else if (ROFF_EXIT == type) {
-		roffnode_free(tree);
-		if ( ! (*tree->cb.roffblkbodyout)(tree->arg, tok))
-			return(0);
-		return((*tree->cb.roffblkout)(tree->arg, tok));
-	} 
+	/* Stack overflow! */
 
-	assert( ! (ROFF_CALLABLE & tokens[tok].flags));
+	if (ROFF_ie == tok && r->rstackpos == RSTACK_MAX - 1) {
+		(*r->msg)(MANDOCERR_MEM, r->data, ln, ppos, NULL);
+		return(ROFF_ERR);
+	}
 
-	++argv;
+	/* First, evaluate the conditional. */
 
-	if ( ! roffparseopts(tree, tok, &argv, argcp, argvp))
-		return(0);
-	if (NULL == roffnode_new(tok, tree))
-		return(0);
+	if (ROFF_el == tok) {
+		/* 
+		 * An `.el' will get the value of the current rstack
+		 * entry set in prior `ie' calls or defaults to DENY.
+	 	 */
+		if (r->rstackpos < 0)
+			rule = ROFFRULE_DENY;
+		else
+			rule = r->rstack[r->rstackpos];
+	} else
+		rule = roff_evalcond(*bufp, &pos);
+
+	sv = pos;
+
+	while (' ' == (*bufp)[pos])
+		pos++;
 
 	/*
-	 * Layouts have two parts: the layout body and header.  The
-	 * layout header is the trailing text of the line macro, while
-	 * the layout body is everything following until termination.
+	 * Roff is weird.  If we have just white-space after the
+	 * conditional, it's considered the BODY and we exit without
+	 * really doing anything.  Warn about this.  It's probably
+	 * wrong.
 	 */
 
-	if ( ! (*tree->cb.roffblkin)(tree->arg, tok, argcp, argvp))
-		return(0);
-	if (NULL == *argv)
-		return((*tree->cb.roffblkbodyin)
-				(tree->arg, tok, argcp, argvp));
+	if ('\0' == (*bufp)[pos] && sv != pos) {
+		if ((*r->msg)(MANDOCERR_NOARGS, r->data, ln, ppos, NULL))
+			return(ROFF_IGN);
+		return(ROFF_ERR);
+	}
 
-	if ( ! (*tree->cb.roffblkheadin)(tree->arg, tok, argcp, argvp))
-		return(0);
+	if ( ! roffnode_push(r, tok, ln, ppos))
+		return(ROFF_ERR);
 
-	/*
-	 * If there are no parsable parts, then write remaining tokens
-	 * into the layout header and exit.
-	 */
+	r->last->rule = rule;
 
-	if ( ! (ROFF_PARSED & tokens[tok].flags)) {
-		i = 0;
-		while (*argv)
-			if ( ! roffdata(tree, i++, *argv++))
-				return(0);
+	ROFF_DEBUG("roff: cond: %s -> %s\n", roffs[tok].name, 
+			ROFFRULE_ALLOW == rule ?  "allow" : "deny");
 
-		if ( ! (*tree->cb.roffblkheadout)(tree->arg, tok))
-			return(0);
-		return((*tree->cb.roffblkbodyin)
-				(tree->arg, tok, argcp, argvp));
+	if (ROFF_ie == tok) {
+		/*
+		 * An if-else will put the NEGATION of the current
+		 * evaluated conditional into the stack.
+		 */
+		r->rstackpos++;
+		if (ROFFRULE_DENY == r->last->rule)
+			r->rstack[r->rstackpos] = ROFFRULE_ALLOW;
+		else
+			r->rstack[r->rstackpos] = ROFFRULE_DENY;
 	}
 
-	/*
-	 * Parsable elements may be in the header (or be the header, for
-	 * that matter).  Follow the regular parsing rules for these.
-	 */
+	/* If the parent has false as its rule, then so do we. */
 
-	i = 0;
-	while (*argv) {
-		if (ROFF_MAX == (c = rofffindcallable(*argv))) {
-			assert(tree->arg);
-			if ( ! roffdata(tree, i++, *argv++))
-				return(0);
-			continue;
-		}
-		if ( ! roffcall(tree, c, argv))
-			return(0);
-		break;
+	if (r->last->parent && ROFFRULE_DENY == r->last->parent->rule) {
+		r->last->rule = ROFFRULE_DENY;
+		ROFF_DEBUG("roff: cond override: %s -> deny\n",
+				roffs[tok].name);
 	}
 
-	/* 
-	 * If there's trailing punctuation in the header, then write it
-	 * out now.  Here we mimic the behaviour of a line-dominant text
-	 * macro.
+	/*
+	 * Determine scope.  If we're invoked with "\{" trailing the
+	 * conditional, then we're in a multiline scope.  Else our scope
+	 * expires on the next line.
 	 */
 
-	if (NULL == *argv) {
-		if ( ! (*tree->cb.roffblkheadout)(tree->arg, tok))
-			return(0);
-		return((*tree->cb.roffblkbodyin)
-				(tree->arg, tok, argcp, argvp));
-	}
+	r->last->endspan = 1;
+
+	if ('\\' == (*bufp)[pos] && '{' == (*bufp)[pos + 1]) {
+		r->last->endspan = -1;
+		pos += 2;
+		ROFF_DEBUG("roff: cond-scope: %s, multi-line\n", 
+				roffs[tok].name);
+	} else
+		ROFF_DEBUG("roff: cond-scope: %s, one-line\n", 
+				roffs[tok].name);
 
 	/*
-	 * Expensive.  Scan to the end of line then work backwards until
-	 * a token isn't punctuation.
+	 * If there are no arguments on the line, the next-line scope is
+	 * assumed.
 	 */
 
-	if ( ! roffpurgepunct(tree, argv))
-		return(0);
+	if ('\0' == (*bufp)[pos])
+		return(ROFF_IGN);
 
-	if ( ! (*tree->cb.roffblkheadout)(tree->arg, tok))
-		return(0);
-	return((*tree->cb.roffblkbodyin)
-			(tree->arg, tok, argcp, argvp));
+	/* Otherwise re-run the roff parser after recalculating. */
+
+	*offs = pos;
+	return(ROFF_RERUN);
 }
 
 
 /* ARGSUSED */
-static int
-roff_ordered(ROFFCALL_ARGS) 
+static enum rofferr
+roff_ds(ROFF_ARGS)
 {
-	int		 i, first, c, argcp[ROFF_MAXLINEARG];
-	char		*ordp[ROFF_MAXLINEARG], *p,
-			*argvp[ROFF_MAXLINEARG];
-
-	if (ROFF_PRELUDE & tree->state) {
-		roff_err(tree, *argv, "`%s' disallowed in prelude", 
-				toknames[tok]);
-		return(0);
+	char *name, *string, *end;
+
+	name = *bufp + pos;
+	if ('\0' == *name)
+		return(ROFF_IGN);
+
+	string = name;
+	while (*string && ' ' != *string)
+		string++;
+	if (*string)
+		*(string++) = NULL;
+	if (*string && '"' == *string)
+		string++;
+	while (*string && ' ' == *string)
+		string++;
+	end = string;
+	while (*end)
+		end++;
+	if (string < end) {
+		end--;
+		if (*end == '"')
+			*end = '\0';
 	}
 
-	first = (*argv == tree->cur);
-	p = *argv++;
-
-	if ( ! roffparseopts(tree, tok, &argv, argcp, argvp))
-		return(0);
-
-	if (NULL == *argv)
-		return(roffspecial(tree, tok, p, 0, ordp));
-
-	i = 0;
-	while (*argv && i < ROFF_MAXLINEARG) {
-		c = ROFF_PARSED & tokens[tok].flags ?
-			rofffindcallable(*argv) : ROFF_MAX;
-
-		if (ROFF_MAX == c && ! roffispunct(*argv)) {
-			ordp[i++] = *argv++;
-			continue;
-		}
-		ordp[i] = NULL;
-
-		if (ROFF_MAX == c)
-			break;
-
-		if ( ! roffspecial(tree, tok, p, (size_t)i, ordp))
-			return(0);
-
-		return(roffcall(tree, c, argv));
-	}
-
-	assert(i != ROFF_MAXLINEARG);
-	ordp[i] = NULL;
-
-	if ( ! roffspecial(tree, tok, p, (size_t)i, ordp))
-		return(0);
-
-	/* FIXME: error if there's stuff after the punctuation. */
-
-	if ( ! first || NULL == *argv)
-		return(1);
-
-	return(roffpurgepunct(tree, argv));
+	roff_setstr(r, name, string);
+	return(ROFF_IGN);
 }
 
 
 /* ARGSUSED */
-static int
-roff_text(ROFFCALL_ARGS) 
+static enum rofferr
+roff_nr(ROFF_ARGS)
 {
-	int		 i, j, first, c, argcp[ROFF_MAXLINEARG];
-	char		*argvp[ROFF_MAXLINEARG];
+	const char	*key, *val;
+	struct reg	*rg;
 
-	if (ROFF_PRELUDE & tree->state) {
-		roff_err(tree, *argv, "`%s' disallowed in prelude", 
-				toknames[tok]);
-		return(0);
-	}
+	key = &(*bufp)[pos];
+	rg = r->regs->regs;
 
-	first = (*argv == tree->cur);
-	argv++;
-
-	if ( ! roffparseopts(tree, tok, &argv, argcp, argvp))
-		return(0);
-	if ( ! (*tree->cb.roffin)(tree->arg, tok, argcp, argvp))
-		return(0);
-	if (NULL == *argv)
-		return((*tree->cb.roffout)(tree->arg, tok));
-
-	if ( ! (ROFF_PARSED & tokens[tok].flags)) {
-		i = 0;
-		while (*argv)
-			if ( ! roffdata(tree, i++, *argv++))
-				return(0);
-
-		return((*tree->cb.roffout)(tree->arg, tok));
-	}
+	/* Parse register request. */
+	while ((*bufp)[pos] && ' ' != (*bufp)[pos])
+		pos++;
 
 	/*
-	 * Deal with punctuation.  Ugly.  Work ahead until we encounter
-	 * terminating punctuation.  If we encounter it and all
-	 * subsequent tokens are punctuation, then stop processing (the
-	 * line-dominant macro will print these tokens after closure).
+	 * Set our nil terminator.  Because this line is going to be
+	 * ignored anyway, we can munge it as we please.
 	 */
+	if ((*bufp)[pos])
+		(*bufp)[pos++] = '\0';
 
-	i = 0;
-	while (*argv) {
-		if (ROFF_MAX != (c = rofffindcallable(*argv))) {
-			if ( ! (ROFF_LSCOPE & tokens[tok].flags))
-				if ( ! (*tree->cb.roffout)(tree->arg, tok))
-					return(0);
-	
-			if ( ! roffcall(tree, c, argv))
-				return(0);
-	
-			if (ROFF_LSCOPE & tokens[tok].flags)
-				if ( ! (*tree->cb.roffout)(tree->arg, tok))
-					return(0);
-	
-			break;
-		}
+	/* Skip whitespace to register token. */
+	while ((*bufp)[pos] && ' ' == (*bufp)[pos])
+		pos++;
 
-		if ( ! roffispunct(*argv)) {
-			if ( ! roffdata(tree, i++, *argv++))
-				return(0);
-			continue;
-		}
+	val = &(*bufp)[pos];
 
-		i = 1;
-		for (j = 0; argv[j]; j++)
-			if ( ! roffispunct(argv[j]))
-				break;
+	/* Process register token. */
 
-		if (argv[j]) {
-			if ( ! roffdata(tree, 0, *argv++))
-				return(0);
-			continue;
-		}
+	if (0 == strcmp(key, "nS")) {
+		rg[(int)REG_nS].set = 1;
+		if ( ! roff_parse_nat(val, &rg[(int)REG_nS].v.u))
+			rg[(int)REG_nS].v.u = 0;
 
-		if ( ! (*tree->cb.roffout)(tree->arg, tok))
-			return(0);
-		break;
-	}
-
-	if (NULL == *argv)
-		return((*tree->cb.roffout)(tree->arg, tok));
-	if ( ! first)
-		return(1);
+		ROFF_DEBUG("roff: register nS: %u\n", 
+				rg[(int)REG_nS].v.u);
+	} else
+		ROFF_DEBUG("roff: ignoring register: %s\n", key);
 
-	return(roffpurgepunct(tree, argv));
+	return(ROFF_IGN);
 }
 
 
-/* ARGSUSED */
-static int
-roff_noop(ROFFCALL_ARGS)
+static void
+roff_setstr(struct roff *r, const char *name, const char *string)
 {
+	struct roffstr	 *n;
+	char		 *namecopy;
 
-	return(1);
-}
-
-
-/* ARGSUSED */
-static int
-roff_depr(ROFFCALL_ARGS)
-{
+	n = r->first_string;
+	while (n && strcmp(name, n->name))
+		n = n->next;
 
-	roff_err(tree, *argv, "`%s' is deprecated", toknames[tok]);
-	return(0);
+	if (NULL == n) {
+		namecopy = mandoc_strdup(name);
+		n = mandoc_malloc(sizeof(struct roffstr));
+		n->name = namecopy;
+		n->next = r->first_string;
+		r->first_string = n;
+	} else
+		free(n->string);
+
+	n->string = string ? strdup(string) : NULL;
 }
 
 
-static void
-roff_warn(const struct rofftree *tree, const char *pos, char *fmt, ...)
+static const char *
+roff_getstrn(const struct roff *r, const char *name, size_t len)
 {
-	va_list		 ap;
-	char		 buf[128];
+	const struct roffstr *n;
 
-	va_start(ap, fmt);
-	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
-	va_end(ap);
+	n = r->first_string;
+	while (n && (strncmp(name, n->name, len) || '\0' != n->name[len]))
+		n = n->next;
 
-	(*tree->cb.roffmsg)(tree->arg, 
-			ROFF_WARN, tree->cur, pos, buf);
+	return(n ? n->string : NULL);
 }
 
 
 static void
-roff_err(const struct rofftree *tree, const char *pos, char *fmt, ...)
+roff_freestr(struct roff *r)
 {
-	va_list		 ap;
-	char		 buf[128];
+	struct roffstr	 *n, *nn;
 
-	va_start(ap, fmt);
-	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
-	va_end(ap);
+	for (n = r->first_string; n; n = nn) {
+		free(n->name);
+		free(n->string);
+		nn = n->next;
+		free(n);
+	}
 
-	(*tree->cb.roffmsg)(tree->arg, 
-			ROFF_ERROR, tree->cur, pos, buf);
+	r->first_string = NULL;
 }
-