X-Git-Url: https://git.cameronkatri.com/mandoc.git/blobdiff_plain/f54bc255ec6ce8e5cd01d9299f00e1a96baa51a4..c6cc6d2cdc21391e0fed1b0e6fd715071bee1879:/roff.c

diff --git a/roff.c b/roff.c
index 5a78640e..dd2d926c 100644
--- a/roff.c
+++ b/roff.c
@@ -1,6 +1,7 @@
-/*	$Id: roff.c,v 1.68 2010/05/15 18:43:59 kristaps Exp $ */
+/*	$Id: roff.c,v 1.105 2010/12/01 16:54:25 kristaps Exp $ */
 /*
  * 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
@@ -19,26 +20,75 @@
 #endif
 
 #include <assert.h>
+#include <errno.h>
+#include <ctype.h>
+#include <limits.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdio.h>
 
 #include "mandoc.h"
 #include "roff.h"
+#include "libmandoc.h"
+
+#define	RSTACK_MAX	128
+
+#define	ROFF_CTL(c) \
+	('.' == (c) || '\'' == (c))
+
+#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
 
 enum	rofft {
-	ROFF_de,
-	ROFF_dei,
+	ROFF_ad,
 	ROFF_am,
 	ROFF_ami,
+	ROFF_am1,
+	ROFF_de,
+	ROFF_dei,
+	ROFF_de1,
+	ROFF_ds,
+	ROFF_el,
+	ROFF_hy,
+	ROFF_ie,
+	ROFF_if,
 	ROFF_ig,
-	ROFF_close,
+	ROFF_ne,
+	ROFF_nh,
+	ROFF_nr,
+	ROFF_rm,
+	ROFF_so,
+	ROFF_tr,
+	ROFF_cblock,
+	ROFF_ccond, /* FIXME: remove this. */
 	ROFF_MAX
 };
 
+enum	roffrule {
+	ROFFRULE_ALLOW,
+	ROFFRULE_DENY
+};
+
+
+struct	roffstr {
+	char		*name; /* key of symbol */
+	char		*string; /* current value */
+	struct roffstr	*next; /* next in list */
+};
+
 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;
 };
 
 struct	roffnode {
@@ -46,43 +96,120 @@ struct	roffnode {
 	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 */
 };
 
 #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 /* current pos in buffer */
+			 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	 sub; /* child of control black */
-	roffproc	 new; /* root of stack (type = ROFF_MAX) */
+	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;
 };
 
-static	enum rofferr	 roff_ignore(ROFF_ARGS);
-static	enum rofferr	 roff_new_close(ROFF_ARGS);
-static	enum rofferr	 roff_new_ig(ROFF_ARGS);
-static	enum rofferr	 roff_sub_ig(ROFF_ARGS);
-
-const	struct roffmac	 roffs[ROFF_MAX] = {
-	{ "de", NULL, roff_ignore },
-	{ "dei", NULL, roff_ignore },
-	{ "am", NULL, roff_ignore },
-	{ "ami", NULL, roff_ignore },
-	{ "ig", roff_sub_ig, roff_new_ig },
-	{ ".", NULL, roff_new_close },
+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_ignore(ROFF_ARGS);
+static	enum rofferr	 roff_line_error(ROFF_ARGS);
+static	enum rofferr	 roff_nr(ROFF_ARGS);
+static	int		 roff_res(struct roff *, 
+				char **, size_t *, int);
+static	void		 roff_setstr(struct roff *,
+				const char *, const char *);
+static	enum rofferr	 roff_so(ROFF_ARGS);
+static	char		*roff_strdup(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] = {
+	{ "ad", roff_line_ignore, NULL, NULL, 0, NULL },
+	{ "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 },
+	{ "hy", roff_line_ignore, NULL, NULL, 0, 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 },
+	{ "ne", roff_line_ignore, NULL, NULL, 0, NULL },
+	{ "nh", roff_line_ignore, NULL, NULL, 0, NULL },
+	{ "nr", roff_nr, NULL, NULL, 0, NULL },
+	{ "rm", roff_line_error, NULL, NULL, 0, NULL },
+	{ "so", roff_so, NULL, NULL, 0, NULL },
+	{ "tr", roff_line_ignore, NULL, NULL, 0, NULL },
+	{ ".", roff_cblock, NULL, NULL, 0, NULL },
+	{ "\\}", roff_ccond, NULL, NULL, 0, NULL },
 };
 
-static	void		 roff_alloc1(struct roff *);
 static	void		 roff_free1(struct roff *);
 static	enum rofft	 roff_hash_find(const char *);
-static	int		 roffnode_push(struct roff *, 
+static	void		 roff_hash_init(void);
+static	void		 roffnode_cleanscope(struct roff *);
+static	void		 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 *);
+
+/* See roff_hash_find() */
+#define	ROFF_HASH(p)	(p[0] - ASCII_LO)
+
+static void
+roff_hash_init(void)
+{
+	struct roffmac	 *n;
+	int		  buc, i;
+
+	for (i = 0; i < (int)ROFF_MAX; i++) {
+		assert(roffs[i].name[0] >= ASCII_LO);
+		assert(roffs[i].name[0] <= ASCII_HI);
+
+		buc = ROFF_HASH(roffs[i].name);
+
+		if (NULL != (n = hash[buc])) {
+			for ( ; n->next; n = n->next)
+				/* Do nothing. */ ;
+			n->next = &roffs[i];
+		} else
+			hash[buc] = &roffs[i];
+	}
+}
 
 
 /*
@@ -92,13 +219,26 @@ static	enum rofft	 roff_parse(const char *, int *);
 static enum rofft
 roff_hash_find(const char *p)
 {
-	int		 i;
+	int		 buc;
+	struct roffmac	*n;
+
+	/*
+	 * 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 (p[0] < ASCII_LO || p[0] > ASCII_HI)
+		return(ROFF_MAX);
 
-	/* FIXME: make this be fast and efficient. */
+	buc = ROFF_HASH(p);
 
-	for (i = 0; i < (int)ROFF_MAX; i++)
-		if (0 == strcmp(roffs[i].name, p))
-			return((enum rofft)i);
+	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(ROFF_MAX);
 }
@@ -113,9 +253,17 @@ roffnode_pop(struct roff *r)
 {
 	struct roffnode	*p;
 
-	if (NULL == (p = r->last))
-		return;
-	r->last = p->parent;
+	assert(r->last);
+	p = r->last; 
+
+	if (ROFF_el == p->tok)
+		if (r->rstackpos > -1)
+			r->rstackpos--;
+
+	ROFF_DEBUG("roff: popping scope\n");
+	r->last = r->last->parent;
+	if (p->end)
+		free(p->end);
 	free(p);
 }
 
@@ -124,23 +272,19 @@ roffnode_pop(struct roff *r)
  * Push a roff node onto the instruction stack.  This must later be
  * removed with roffnode_pop().
  */
-static int
+static void
 roffnode_push(struct roff *r, enum rofft tok, int line, int col)
 {
 	struct roffnode	*p;
 
-	if (NULL == (p = calloc(1, sizeof(struct roffnode)))) {
-		(*r->msg)(MANDOCERR_MEM, r->data, line, col, NULL);
-		return(0);
-	}
-
+	p = mandoc_calloc(1, sizeof(struct roffnode));
 	p->tok = tok;
 	p->parent = r->last;
 	p->line = line;
 	p->col = col;
+	p->rule = p->parent ? p->parent->rule : ROFFRULE_DENY;
 
 	r->last = p;
-	return(1);
 }
 
 
@@ -150,14 +294,7 @@ roff_free1(struct roff *r)
 
 	while (r->last)
 		roffnode_pop(r);
-}
-
-
-static void
-roff_alloc1(struct roff *r)
-{
-
-	/* Do nothing for now. */
+	roff_freestr(r);
 }
 
 
@@ -166,7 +303,6 @@ roff_reset(struct roff *r)
 {
 
 	roff_free1(r);
-	roff_alloc1(r);
 }
 
 
@@ -180,46 +316,163 @@ roff_free(struct roff *r)
 
 
 struct roff *
-roff_alloc(const mandocmsg msg, void *data)
+roff_alloc(struct regset *regs, void *data, const mandocmsg msg)
 {
 	struct roff	*r;
 
-	if (NULL == (r = calloc(1, sizeof(struct roff)))) {
-		(*msg)(MANDOCERR_MEM, data, 0, 0, NULL);
-		return(0);
-	}
-
+	r = mandoc_calloc(1, sizeof(struct roff));
+	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
+roff_res(struct roff *r, char **bufp, size_t *szp, int pos)
+{
+	const char	*cp, *cpp, *st, *res;
+	int		 i, maxl;
+	size_t		 nsz;
+	char		*n;
+
+	/* LINTED */
+	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;
+		}
+
+		st = cp;
+
+		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);
+
+		if (NULL == res) {
+			cp -= maxl ? 1 : 0;
+			continue;
+		}
+
+		ROFF_DEBUG("roff: splicing reserved: [%.*s]\n", i, st);
+
+		nsz = *szp + strlen(res) + 1;
+		n = mandoc_malloc(nsz);
+
+		*n = '\0';
+
+		strlcat(n, *bufp, (size_t)(cpp - *bufp + 1));
+		strlcat(n, res, nsz);
+		strlcat(n, cp + (maxl ? 0 : 1), nsz);
+
+		free(*bufp);
+
+		*bufp = n;
+		*szp = nsz;
+		return(0);
+	}
+
+	return(1);
+}
+
+
 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 (NULL != r->last) {
-		/*
-		 * If there's a node on the stack, then jump directly
-		 * into its processing function.
-		 */
+	/*
+	 * Run the reserved-word filter only if we have some reserved
+	 * words to fill in.
+	 */
+
+	if (r->first_string && ! roff_res(r, bufp, szp, pos))
+		return(ROFF_RERUN);
+
+	/*
+	 * 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 (r->last && ! ROFF_CTL((*bufp)[pos])) {
 		t = r->last->tok;
-		assert(roffs[t].sub);
-		return((*roffs[t].sub)(r, bufp, szp, ln, 0));
-	} else if ('.' != (*bufp)[0] && NULL == r->last)
-		/* Return when in free text without a context. */
+		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);
 
-	/* There's nothing on the stack: make us anew. */
+	/*
+	 * If a scope is open, go to the child handler for that macro,
+	 * as it may want to preprocess before doing anything with it.
+	 */
 
-	if (ROFF_MAX == (t = roff_parse(*bufp, &ppos)))
+	if (r->last) {
+		t = r->last->tok;
+		assert(roffs[t].sub);
+		ROFF_DEBUG("roff: intercept scoped context: %s, [%s]\n", 
+				roffs[t].name, &(*bufp)[pos]);
+		return((*roffs[t].sub)
+				(r, t, bufp, szp, 
+				 ln, pos, pos, offs));
+	}
+
+	/*
+	 * 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.
+	 */
+
+	ppos = pos;
+	if (ROFF_MAX == (t = roff_parse(*bufp, &pos)))
 		return(ROFF_CONT);
 
-	assert(roffs[t].new);
-	return((*roffs[t].new)(r, bufp, szp, ln, ppos));
+	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));
+}
+
+
+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));
 }
 
 
@@ -234,8 +487,8 @@ roff_parse(const char *buf, int *pos)
 	char		 mac[5];
 	enum rofft	 t;
 
-	assert('.' == buf[0]);
-	*pos = 1;
+	assert(ROFF_CTL(buf[*pos]));
+	(*pos)++;
 
 	while (buf[*pos] && (' ' == buf[*pos] || '\t' == buf[*pos]))
 		(*pos)++;
@@ -246,7 +499,7 @@ roff_parse(const char *buf, int *pos)
 	for (j = 0; j < 4; j++, (*pos)++)
 		if ('\0' == (mac[j] = buf[*pos]))
 			break;
-		else if (' ' == buf[*pos])
+		else if (' ' == buf[*pos] || (j && '\\' == buf[*pos]))
 			break;
 
 	if (j == 4 || j < 1)
@@ -264,67 +517,641 @@ roff_parse(const char *buf, int *pos)
 }
 
 
+static int
+roff_parse_nat(const char *buf, unsigned int *res)
+{
+	char		*ep;
+	long		 lval;
+
+	errno = 0;
+	lval = strtol(buf, &ep, 10);
+	if (buf[0] == '\0' || *ep != '\0')
+		return(0);
+	if ((errno == ERANGE && 
+			(lval == LONG_MAX || lval == LONG_MIN)) ||
+			(lval > INT_MAX || lval < 0))
+		return(0);
+
+	*res = (unsigned int)lval;
+	return(1);
+}
+
+
 /* ARGSUSED */
 static enum rofferr
-roff_ignore(ROFF_ARGS)
+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 (ROFF_ami):
+		/* FALLTHROUGH */
+	case (ROFF_am1):
+		/* FALLTHROUGH */
+	case (ROFF_de):
+		/* FALLTHROUGH */
+	case (ROFF_dei):
+		/* FALLTHROUGH */
+	case (ROFF_de1):
+		/* FALLTHROUGH */
+	case (ROFF_ig):
+		break;
+	default:
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	}
+
+	if ((*bufp)[pos])
+		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, pos, NULL))
+			return(ROFF_ERR);
+
+	roffnode_pop(r);
+	roffnode_cleanscope(r);
 	return(ROFF_IGN);
+
+}
+
+
+static void
+roffnode_cleanscope(struct roff *r)
+{
+
+	while (r->last) {
+		if (--r->last->endspan < 0)
+			break;
+		roffnode_pop(r);
+	}
 }
 
 
 /* ARGSUSED */
 static enum rofferr
-roff_sub_ig(ROFF_ARGS)
+roff_ccond(ROFF_ARGS)
 {
-	enum rofft	 t;
-	int		 pos;
 
-	/* Ignore free-text lines. */
+	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_el):
+		/* FALLTHROUGH */
+	case (ROFF_ie):
+		/* FALLTHROUGH */
+	case (ROFF_if):
+		break;
+	default:
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	}
+
+	if (r->last->endspan > -1) {
+		if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+			return(ROFF_ERR);
+		return(ROFF_IGN);
+	}
+
+	if ((*bufp)[pos])
+		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, pos, NULL))
+			return(ROFF_ERR);
+
+	roffnode_pop(r);
+	roffnode_cleanscope(r);
+	return(ROFF_IGN);
+}
+
+
+/* ARGSUSED */
+static enum rofferr
+roff_block(ROFF_ARGS)
+{
+	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++;
+	}
 
-	if ('.' != (*bufp)[ppos])
+	roffnode_push(r, tok, ln, ppos);
+
+	if ('\0' == (*bufp)[pos])
 		return(ROFF_IGN);
 
-	/* Ignore macros unless it's a closing macro. */
+	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.
+	 */
+
+	assert(pos > sv);
+	sz = (size_t)(pos - sv);
+
+	if (1 == sz && '.' == (*bufp)[sv])
+		return(ROFF_IGN);
+
+	r->last->end = mandoc_malloc(sz + 1);
+
+	memcpy(r->last->end, *bufp + sv, sz);
+	r->last->end[(int)sz] = '\0';
+
+	if ((*bufp)[pos])
+		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, pos, NULL))
+			return(ROFF_ERR);
+
+	return(ROFF_IGN);
+}
+
+
+/* ARGSUSED */
+static enum rofferr
+roff_block_sub(ROFF_ARGS)
+{
+	enum rofft	t;
+	int		i, j;
+
+	/*
+	 * 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.
+	 */
+
+	if (r->last->end) {
+		i = pos + 1;
+		while (' ' == (*bufp)[i] || '\t' == (*bufp)[i])
+			i++;
+
+		for (j = 0; r->last->end[j]; j++, i++)
+			if ((*bufp)[i] != r->last->end[j])
+				break;
+
+		if ('\0' == r->last->end[j] && 
+				('\0' == (*bufp)[i] ||
+				 ' ' == (*bufp)[i] ||
+				 '\t' == (*bufp)[i])) {
+			roffnode_pop(r);
+			roffnode_cleanscope(r);
+
+			if (ROFF_MAX != roff_parse(*bufp, &pos))
+				return(ROFF_RERUN);
+			return(ROFF_IGN);
+		}
+	}
+
+	/*
+	 * If we have no custom end-query or lookup failed, then try
+	 * pulling it out of the hashtable.
+	 */
+
+	ppos = pos;
 	t = roff_parse(*bufp, &pos);
-	if (ROFF_close != t)
+
+	/* If we're not a comment-end, then throw it away. */
+	if (ROFF_cblock != t)
 		return(ROFF_IGN);
 
-	roffnode_pop(r);
+	assert(roffs[t].proc);
+	return((*roffs[t].proc)(r, t, bufp, szp, 
+				ln, ppos, pos, offs));
+}
+
+
+/* ARGSUSED */
+static enum rofferr
+roff_block_text(ROFF_ARGS)
+{
+
 	return(ROFF_IGN);
 }
 
 
 /* ARGSUSED */
 static enum rofferr
-roff_new_close(ROFF_ARGS)
+roff_cond_sub(ROFF_ARGS)
 {
+	enum rofft	 t;
+	enum roffrule	 rr;
+
+	ppos = pos;
+	rr = r->last->rule;
+
+	/* 
+	 * Clean out scope.  If we've closed ourselves, then don't
+	 * continue. 
+	 */
+
+	roffnode_cleanscope(r);
+
+	if (ROFF_MAX == (t = roff_parse(*bufp, &pos))) {
+		if ('\\' == (*bufp)[pos] && '}' == (*bufp)[pos + 1])
+			return(roff_ccond
+				(r, ROFF_ccond, bufp, szp, 
+				 ln, pos, pos + 2, offs));
+		return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
+	}
+
+	/*
+	 * 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 enum rofferr
+roff_cond_text(ROFF_ARGS)
+{
+	char		*ep, *st;
+	enum roffrule	 rr;
+
+	rr = r->last->rule;
+
+	/*
+	 * We display the value of the text if out current evaluation
+	 * scope permits us to do so.
+	 */
+
+	/* FIXME: use roff_ccond? */
+
+	st = &(*bufp)[pos];
+	if (NULL == (ep = strstr(st, "\\}"))) {
+		roffnode_cleanscope(r);
+		return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
+	}
+
+	if (ep == st || (ep > st && '\\' != *(ep - 1)))
+		roffnode_pop(r);
+
+	roffnode_cleanscope(r);
+	return(ROFFRULE_DENY == rr ? ROFF_IGN : ROFF_CONT);
+}
+
+
+static enum roffrule
+roff_evalcond(const char *v, int *pos)
+{
+
+	switch (v[*pos]) {
+	case ('n'):
+		(*pos)++;
+		return(ROFFRULE_ALLOW);
+	case ('e'):
+		/* FALLTHROUGH */
+	case ('o'):
+		/* FALLTHROUGH */
+	case ('t'):
+		(*pos)++;
+		return(ROFFRULE_DENY);
+	default:
+		break;
+	}
+
+	while (v[*pos] && ' ' != v[*pos])
+		(*pos)++;
+	return(ROFFRULE_DENY);
+}
+
+/* ARGSUSED */
+static enum rofferr
+roff_line_ignore(ROFF_ARGS)
+{
+
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
+roff_line_error(ROFF_ARGS)
+{
+
+	(*r->msg)(MANDOCERR_REQUEST, r->data, ln, ppos, roffs[tok].name);
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
+roff_cond(ROFF_ARGS)
+{
+	int		 sv;
+	enum roffrule	 rule;
+
+	/* Stack overflow! */
+
+	if (ROFF_ie == tok && r->rstackpos == RSTACK_MAX - 1) {
+		(*r->msg)(MANDOCERR_MEM, r->data, ln, ppos, NULL);
+		return(ROFF_ERR);
+	}
+
+	/* First, evaluate the conditional. */
+
+	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++;
 
 	/*
-	if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
+	 * 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 ('\0' == (*bufp)[pos] && sv != pos) {
+		if ((*r->msg)(MANDOCERR_NOARGS, r->data, ln, ppos, NULL))
+			return(ROFF_IGN);
 		return(ROFF_ERR);
-	*/
-	return(ROFF_CONT);
+	}
+
+	roffnode_push(r, tok, ln, ppos);
+
+	r->last->rule = rule;
+
+	ROFF_DEBUG("roff: cond: %s -> %s\n", roffs[tok].name, 
+			ROFFRULE_ALLOW == rule ?  "allow" : "deny");
+
+	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;
+	}
+
+	/* If the parent has false as its rule, then so do we. */
+
+	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);
+	}
+
+	/*
+	 * 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.
+	 */
+
+	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);
+
+	/*
+	 * If there are no arguments on the line, the next-line scope is
+	 * assumed.
+	 */
+
+	if ('\0' == (*bufp)[pos])
+		return(ROFF_IGN);
+
+	/* Otherwise re-run the roff parser after recalculating. */
+
+	*offs = pos;
+	return(ROFF_RERUN);
 }
 
 
 /* ARGSUSED */
 static enum rofferr
-roff_new_ig(ROFF_ARGS)
+roff_ds(ROFF_ARGS)
 {
+	char		*name, *string;
+
+	/*
+	 * A symbol is named by the first word following the macro
+	 * invocation up to a space.  Its value is anything after the
+	 * name's trailing whitespace and optional double-quote.  Thus,
+	 *
+	 *  [.ds foo "bar  "     ]
+	 *
+	 * will have `bar  "     ' as its value.
+	 */
+
+	name = *bufp + pos;
+	if ('\0' == *name)
+		return(ROFF_IGN);
 
-	return(roffnode_push(r, ROFF_ig, ln, ppos) ? 
-			ROFF_IGN : ROFF_ERR);
+	string = name;
+	/* Read until end of name. */
+	while (*string && ' ' != *string)
+		string++;
+
+	/* Nil-terminate name. */
+	if (*string)
+		*(string++) = '\0';
+	
+	/* Read past spaces. */
+	while (*string && ' ' == *string)
+		string++;
+
+	/* Read passed initial double-quote. */
+	if (*string && '"' == *string)
+		string++;
+
+	/* The rest is the value. */
+	roff_setstr(r, name, string);
+	return(ROFF_IGN);
 }
 
 
-int
-roff_endparse(struct roff *r)
+/* ARGSUSED */
+static enum rofferr
+roff_nr(ROFF_ARGS)
 {
+	const char	*key, *val;
+	struct reg	*rg;
 
-	if (NULL == r->last)
-		return(1);
-	return((*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
-				r->last->line, r->last->col, NULL));
+	key = &(*bufp)[pos];
+	rg = r->regs->regs;
+
+	/* Parse register request. */
+	while ((*bufp)[pos] && ' ' != (*bufp)[pos])
+		pos++;
+
+	/*
+	 * 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';
+
+	/* Skip whitespace to register token. */
+	while ((*bufp)[pos] && ' ' == (*bufp)[pos])
+		pos++;
+
+	val = &(*bufp)[pos];
+
+	/* Process register token. */
+
+	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;
+
+		ROFF_DEBUG("roff: register nS: %u\n", 
+				rg[(int)REG_nS].v.u);
+	} else
+		ROFF_DEBUG("roff: ignoring register: %s\n", key);
+
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
+roff_so(ROFF_ARGS)
+{
+	char *name;
+
+	(*r->msg)(MANDOCERR_SO, r->data, ln, ppos, NULL);
+
+	/*
+	 * Handle `so'.  Be EXTREMELY careful, as we shouldn't be
+	 * opening anything that's not in our cwd or anything beneath
+	 * it.  Thus, explicitly disallow traversing up the file-system
+	 * or using absolute paths.
+	 */
+
+	name = *bufp + pos;
+	if ('/' == *name || strstr(name, "../") || strstr(name, "/..")) {
+		(*r->msg)(MANDOCERR_SOPATH, r->data, ln, pos, NULL);
+		return(ROFF_ERR);
+	}
+
+	*offs = pos;
+	return(ROFF_SO);
+}
+
+static char *
+roff_strdup(const char *name)
+{
+	char		*namecopy, *sv;
+
+	/* 
+	 * This isn't a nice simple mandoc_strdup() because we must
+	 * handle roff's stupid double-escape rule. 
+	 */
+	sv = namecopy = mandoc_malloc(strlen(name) + 1);
+	while (*name) {
+		if ('\\' == *name && '\\' == *(name + 1))
+			name++;
+		*namecopy++ = *name++;
+	}
+
+	*namecopy = '\0';
+	return(sv);
+}
+
+
+static void
+roff_setstr(struct roff *r, const char *name, const char *string)
+{
+	struct roffstr	 *n;
+	char		 *namecopy;
+
+	n = r->first_string;
+	while (n && strcmp(name, n->name))
+		n = n->next;
+
+	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);
+
+	/* Don't use mandoc_strdup: clean out double-escapes. */
+	n->string = string ? roff_strdup(string) : NULL;
+	ROFF_DEBUG("roff: new symbol: [%s] = [%s]\n", name, n->string);
+}
+
+
+static const char *
+roff_getstrn(const struct roff *r, const char *name, size_t len)
+{
+	const struct roffstr *n;
+
+	n = r->first_string;
+	while (n && (strncmp(name, n->name, len) || '\0' != n->name[(int)len]))
+		n = n->next;
+
+	return(n ? n->string : NULL);
+}
+
+
+static void
+roff_freestr(struct roff *r)
+{
+	struct roffstr	 *n, *nn;
+
+	for (n = r->first_string; n; n = nn) {
+		free(n->name);
+		free(n->string);
+		nn = n->next;
+		free(n);
+	}
+
+	r->first_string = NULL;
 }