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File: [cvsweb.bsd.lv] / mandoc / roff.c (download)

Revision 1.269, Thu Apr 23 16:17:44 2015 UTC (8 years, 11 months ago) by schwarze
Branch: MAIN
Changes since 1.268: +47 -1 lines

Unify mdoc_deroff() and man_deroff() into a common function deroff().
No functional change except that for mdoc(7), it now skips leading
escape sequences just like it already did for man(7).
Escape sequences rarely occur in mdoc(7) code and if they do,
skipping them is an improvement in this context.
Minus 30 lines of code.

/*	$Id: roff.c,v 1.269 2015/04/23 16:17:44 schwarze Exp $ */
/*
 * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2010-2015 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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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 "config.h"

#include <sys/types.h>

#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "mandoc.h"
#include "mandoc_aux.h"
#include "roff.h"
#include "libmandoc.h"
#include "roff_int.h"
#include "libroff.h"

/* Maximum number of nested if-else conditionals. */
#define	RSTACK_MAX	128

/* Maximum number of string expansions per line, to break infinite loops. */
#define	EXPAND_LIMIT	1000

/* --- data types --------------------------------------------------------- */

enum	rofft {
	ROFF_ab,
	ROFF_ad,
	ROFF_af,
	ROFF_aln,
	ROFF_als,
	ROFF_am,
	ROFF_am1,
	ROFF_ami,
	ROFF_ami1,
	ROFF_as,
	ROFF_as1,
	ROFF_asciify,
	ROFF_backtrace,
	ROFF_bd,
	ROFF_bleedat,
	ROFF_blm,
	ROFF_box,
	ROFF_boxa,
	ROFF_bp,
	ROFF_BP,
	/* MAN_br, MDOC_br */
	ROFF_break,
	ROFF_breakchar,
	ROFF_brnl,
	ROFF_brp,
	ROFF_brpnl,
	ROFF_c2,
	ROFF_cc,
	ROFF_ce,
	ROFF_cf,
	ROFF_cflags,
	ROFF_ch,
	ROFF_char,
	ROFF_chop,
	ROFF_class,
	ROFF_close,
	ROFF_CL,
	ROFF_color,
	ROFF_composite,
	ROFF_continue,
	ROFF_cp,
	ROFF_cropat,
	ROFF_cs,
	ROFF_cu,
	ROFF_da,
	ROFF_dch,
	ROFF_Dd,
	ROFF_de,
	ROFF_de1,
	ROFF_defcolor,
	ROFF_dei,
	ROFF_dei1,
	ROFF_device,
	ROFF_devicem,
	ROFF_di,
	ROFF_do,
	ROFF_ds,
	ROFF_ds1,
	ROFF_dwh,
	ROFF_dt,
	ROFF_ec,
	ROFF_ecr,
	ROFF_ecs,
	ROFF_el,
	ROFF_em,
	ROFF_EN,
	ROFF_eo,
	ROFF_EP,
	ROFF_EQ,
	ROFF_errprint,
	ROFF_ev,
	ROFF_evc,
	ROFF_ex,
	ROFF_fallback,
	ROFF_fam,
	ROFF_fc,
	ROFF_fchar,
	ROFF_fcolor,
	ROFF_fdeferlig,
	ROFF_feature,
	/* MAN_fi; ignored in mdoc(7) */
	ROFF_fkern,
	ROFF_fl,
	ROFF_flig,
	ROFF_fp,
	ROFF_fps,
	ROFF_fschar,
	ROFF_fspacewidth,
	ROFF_fspecial,
	/* MAN_ft; ignored in mdoc(7) */
	ROFF_ftr,
	ROFF_fzoom,
	ROFF_gcolor,
	ROFF_hc,
	ROFF_hcode,
	ROFF_hidechar,
	ROFF_hla,
	ROFF_hlm,
	ROFF_hpf,
	ROFF_hpfa,
	ROFF_hpfcode,
	ROFF_hw,
	ROFF_hy,
	ROFF_hylang,
	ROFF_hylen,
	ROFF_hym,
	ROFF_hypp,
	ROFF_hys,
	ROFF_ie,
	ROFF_if,
	ROFF_ig,
	/* MAN_in; ignored in mdoc(7) */
	ROFF_index,
	ROFF_it,
	ROFF_itc,
	ROFF_IX,
	ROFF_kern,
	ROFF_kernafter,
	ROFF_kernbefore,
	ROFF_kernpair,
	ROFF_lc,
	ROFF_lc_ctype,
	ROFF_lds,
	ROFF_length,
	ROFF_letadj,
	ROFF_lf,
	ROFF_lg,
	ROFF_lhang,
	ROFF_linetabs,
	/* MAN_ll, MDOC_ll */
	ROFF_lnr,
	ROFF_lnrf,
	ROFF_lpfx,
	ROFF_ls,
	ROFF_lsm,
	ROFF_lt,
	ROFF_mc,
	ROFF_mediasize,
	ROFF_minss,
	ROFF_mk,
	ROFF_mso,
	ROFF_na,
	ROFF_ne,
	/* MAN_nf; ignored in mdoc(7) */
	ROFF_nh,
	ROFF_nhychar,
	ROFF_nm,
	ROFF_nn,
	ROFF_nop,
	ROFF_nr,
	ROFF_nrf,
	ROFF_nroff,
	ROFF_ns,
	ROFF_nx,
	ROFF_open,
	ROFF_opena,
	ROFF_os,
	ROFF_output,
	ROFF_padj,
	ROFF_papersize,
	ROFF_pc,
	ROFF_pev,
	ROFF_pi,
	ROFF_PI,
	ROFF_pl,
	ROFF_pm,
	ROFF_pn,
	ROFF_pnr,
	ROFF_po,
	ROFF_ps,
	ROFF_psbb,
	ROFF_pshape,
	ROFF_pso,
	ROFF_ptr,
	ROFF_pvs,
	ROFF_rchar,
	ROFF_rd,
	ROFF_recursionlimit,
	ROFF_return,
	ROFF_rfschar,
	ROFF_rhang,
	ROFF_rj,
	ROFF_rm,
	ROFF_rn,
	ROFF_rnn,
	ROFF_rr,
	ROFF_rs,
	ROFF_rt,
	ROFF_schar,
	ROFF_sentchar,
	ROFF_shc,
	ROFF_shift,
	ROFF_sizes,
	ROFF_so,
	/* MAN_sp, MDOC_sp */
	ROFF_spacewidth,
	ROFF_special,
	ROFF_spreadwarn,
	ROFF_ss,
	ROFF_sty,
	ROFF_substring,
	ROFF_sv,
	ROFF_sy,
	ROFF_T_,
	ROFF_ta,
	ROFF_tc,
	ROFF_TE,
	ROFF_TH,
	ROFF_ti,
	ROFF_tkf,
	ROFF_tl,
	ROFF_tm,
	ROFF_tm1,
	ROFF_tmc,
	ROFF_tr,
	ROFF_track,
	ROFF_transchar,
	ROFF_trf,
	ROFF_trimat,
	ROFF_trin,
	ROFF_trnt,
	ROFF_troff,
	ROFF_TS,
	ROFF_uf,
	ROFF_ul,
	ROFF_unformat,
	ROFF_unwatch,
	ROFF_unwatchn,
	ROFF_vpt,
	ROFF_vs,
	ROFF_warn,
	ROFF_warnscale,
	ROFF_watch,
	ROFF_watchlength,
	ROFF_watchn,
	ROFF_wh,
	ROFF_while,
	ROFF_write,
	ROFF_writec,
	ROFF_writem,
	ROFF_xflag,
	ROFF_cblock,
	ROFF_USERDEF,
	ROFF_MAX
};

/*
 * An incredibly-simple string buffer.
 */
struct	roffstr {
	char		*p; /* nil-terminated buffer */
	size_t		 sz; /* saved strlen(p) */
};

/*
 * A key-value roffstr pair as part of a singly-linked list.
 */
struct	roffkv {
	struct roffstr	 key;
	struct roffstr	 val;
	struct roffkv	*next; /* next in list */
};

/*
 * A single number register as part of a singly-linked list.
 */
struct	roffreg {
	struct roffstr	 key;
	int		 val;
	struct roffreg	*next;
};

struct	roff {
	struct mparse	*parse; /* parse point */
	const struct mchars *mchars; /* character table */
	struct roffnode	*last; /* leaf of stack */
	int		*rstack; /* stack of inverted `ie' values */
	struct roffreg	*regtab; /* number registers */
	struct roffkv	*strtab; /* user-defined strings & macros */
	struct roffkv	*xmbtab; /* multi-byte trans table (`tr') */
	struct roffstr	*xtab; /* single-byte trans table (`tr') */
	const char	*current_string; /* value of last called user macro */
	struct tbl_node	*first_tbl; /* first table parsed */
	struct tbl_node	*last_tbl; /* last table parsed */
	struct tbl_node	*tbl; /* current table being parsed */
	struct eqn_node	*last_eqn; /* last equation parsed */
	struct eqn_node	*first_eqn; /* first equation parsed */
	struct eqn_node	*eqn; /* current equation being parsed */
	int		 eqn_inline; /* current equation is inline */
	int		 options; /* parse options */
	int		 rstacksz; /* current size limit of rstack */
	int		 rstackpos; /* position in rstack */
	int		 format; /* current file in mdoc or man format */
	char		 control; /* control character */
};

struct	roffnode {
	enum rofft	 tok; /* type of node */
	struct roffnode	*parent; /* up one in stack */
	int		 line; /* parse line */
	int		 col; /* parse col */
	char		*name; /* node name, e.g. macro name */
	char		*end; /* end-rules: custom token */
	int		 endspan; /* end-rules: next-line or infty */
	int		 rule; /* current evaluation rule */
};

#define	ROFF_ARGS	 struct roff *r, /* parse ctx */ \
			 enum rofft tok, /* tok of macro */ \
			 struct buf *buf, /* 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;
};

struct	predef {
	const char	*name; /* predefined input name */
	const char	*str; /* replacement symbol */
};

#define	PREDEF(__name, __str) \
	{ (__name), (__str) },

/* --- function prototypes ------------------------------------------------ */

static	enum rofft	 roffhash_find(const char *, size_t);
static	void		 roffhash_init(void);
static	void		 roffnode_cleanscope(struct roff *);
static	void		 roffnode_pop(struct roff *);
static	void		 roffnode_push(struct roff *, enum rofft,
				const char *, int, int);
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_brp(ROFF_ARGS);
static	enum rofferr	 roff_cblock(ROFF_ARGS);
static	enum rofferr	 roff_cc(ROFF_ARGS);
static	void		 roff_ccond(struct roff *, int, int);
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 rofferr	 roff_eqndelim(struct roff *, struct buf *, int);
static	int		 roff_evalcond(struct roff *r, int,
				const char *, int *);
static	int		 roff_evalnum(struct roff *, int,
				const char *, int *, int *, int);
static	int		 roff_evalpar(struct roff *, int,
				const char *, int *, int *, int);
static	int		 roff_evalstrcond(const char *, int *);
static	void		 roff_free1(struct roff *);
static	void		 roff_freereg(struct roffreg *);
static	void		 roff_freestr(struct roffkv *);
static	size_t		 roff_getname(struct roff *, char **, int, int);
static	int		 roff_getnum(const char *, int *, int *, int);
static	int		 roff_getop(const char *, int *, char *);
static	int		 roff_getregn(const struct roff *,
				const char *, size_t);
static	int		 roff_getregro(const char *name);
static	const char	*roff_getstrn(const struct roff *,
				const char *, size_t);
static	enum rofferr	 roff_insec(ROFF_ARGS);
static	enum rofferr	 roff_it(ROFF_ARGS);
static	enum rofferr	 roff_line_ignore(ROFF_ARGS);
static	void		 roff_man_alloc1(struct roff_man *);
static	void		 roff_man_free1(struct roff_man *);
static	enum rofferr	 roff_nr(ROFF_ARGS);
static	enum rofft	 roff_parse(struct roff *, char *, int *,
				int, int);
static	enum rofferr	 roff_parsetext(struct buf *, int, int *);
static	enum rofferr	 roff_res(struct roff *, struct buf *, int, int);
static	enum rofferr	 roff_rm(ROFF_ARGS);
static	enum rofferr	 roff_rr(ROFF_ARGS);
static	void		 roff_setstr(struct roff *,
				const char *, const char *, int);
static	void		 roff_setstrn(struct roffkv **, const char *,
				size_t, const char *, size_t, int);
static	enum rofferr	 roff_so(ROFF_ARGS);
static	enum rofferr	 roff_tr(ROFF_ARGS);
static	enum rofferr	 roff_Dd(ROFF_ARGS);
static	enum rofferr	 roff_TH(ROFF_ARGS);
static	enum rofferr	 roff_TE(ROFF_ARGS);
static	enum rofferr	 roff_TS(ROFF_ARGS);
static	enum rofferr	 roff_EQ(ROFF_ARGS);
static	enum rofferr	 roff_EN(ROFF_ARGS);
static	enum rofferr	 roff_T_(ROFF_ARGS);
static	enum rofferr	 roff_unsupp(ROFF_ARGS);
static	enum rofferr	 roff_userdef(ROFF_ARGS);

/* --- constant data ------------------------------------------------------ */

/* See roffhash_find() */

#define	ASCII_HI	 126
#define	ASCII_LO	 33
#define	HASHWIDTH	(ASCII_HI - ASCII_LO + 1)

#define	ROFFNUM_SCALE	(1 << 0)  /* Honour scaling in roff_getnum(). */
#define	ROFFNUM_WHITE	(1 << 1)  /* Skip whitespace in roff_evalnum(). */

static	struct roffmac	*hash[HASHWIDTH];

static	struct roffmac	 roffs[ROFF_MAX] = {
	{ "ab", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ad", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "af", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "aln", roff_unsupp, NULL, NULL, 0, NULL },
	{ "als", roff_unsupp, NULL, NULL, 0, NULL },
	{ "am", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "am1", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "ami", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "ami1", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "as", roff_ds, NULL, NULL, 0, NULL },
	{ "as1", roff_ds, NULL, NULL, 0, NULL },
	{ "asciify", roff_unsupp, NULL, NULL, 0, NULL },
	{ "backtrace", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "bd", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "bleedat", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "blm", roff_unsupp, NULL, NULL, 0, NULL },
	{ "box", roff_unsupp, NULL, NULL, 0, NULL },
	{ "boxa", roff_unsupp, NULL, NULL, 0, NULL },
	{ "bp", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "BP", roff_unsupp, NULL, NULL, 0, NULL },
	{ "break", roff_unsupp, NULL, NULL, 0, NULL },
	{ "breakchar", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "brnl", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "brp", roff_brp, NULL, NULL, 0, NULL },
	{ "brpnl", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "c2", roff_unsupp, NULL, NULL, 0, NULL },
	{ "cc", roff_cc, NULL, NULL, 0, NULL },
	{ "ce", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "cf", roff_insec, NULL, NULL, 0, NULL },
	{ "cflags", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ch", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "char", roff_unsupp, NULL, NULL, 0, NULL },
	{ "chop", roff_unsupp, NULL, NULL, 0, NULL },
	{ "class", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "close", roff_insec, NULL, NULL, 0, NULL },
	{ "CL", roff_unsupp, NULL, NULL, 0, NULL },
	{ "color", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "composite", roff_unsupp, NULL, NULL, 0, NULL },
	{ "continue", roff_unsupp, NULL, NULL, 0, NULL },
	{ "cp", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "cropat", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "cs", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "cu", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "da", roff_unsupp, NULL, NULL, 0, NULL },
	{ "dch", roff_unsupp, NULL, NULL, 0, NULL },
	{ "Dd", roff_Dd, NULL, NULL, 0, NULL },
	{ "de", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "de1", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "defcolor", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "dei", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "dei1", roff_block, roff_block_text, roff_block_sub, 0, NULL },
	{ "device", roff_unsupp, NULL, NULL, 0, NULL },
	{ "devicem", roff_unsupp, NULL, NULL, 0, NULL },
	{ "di", roff_unsupp, NULL, NULL, 0, NULL },
	{ "do", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ds", roff_ds, NULL, NULL, 0, NULL },
	{ "ds1", roff_ds, NULL, NULL, 0, NULL },
	{ "dwh", roff_unsupp, NULL, NULL, 0, NULL },
	{ "dt", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ec", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ecr", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ecs", roff_unsupp, NULL, NULL, 0, NULL },
	{ "el", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
	{ "em", roff_unsupp, NULL, NULL, 0, NULL },
	{ "EN", roff_EN, NULL, NULL, 0, NULL },
	{ "eo", roff_unsupp, NULL, NULL, 0, NULL },
	{ "EP", roff_unsupp, NULL, NULL, 0, NULL },
	{ "EQ", roff_EQ, NULL, NULL, 0, NULL },
	{ "errprint", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ev", roff_unsupp, NULL, NULL, 0, NULL },
	{ "evc", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ex", roff_unsupp, NULL, NULL, 0, NULL },
	{ "fallback", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fam", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fc", roff_unsupp, NULL, NULL, 0, NULL },
	{ "fchar", roff_unsupp, NULL, NULL, 0, NULL },
	{ "fcolor", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fdeferlig", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "feature", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fkern", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fl", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "flig", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fp", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fps", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fschar", roff_unsupp, NULL, NULL, 0, NULL },
	{ "fspacewidth", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fspecial", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ftr", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "fzoom", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "gcolor", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hc", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hcode", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hidechar", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hla", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hlm", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hpf", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hpfa", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hpfcode", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hw", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hy", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hylang", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hylen", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hym", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hypp", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "hys", 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 },
	{ "index", roff_unsupp, NULL, NULL, 0, NULL },
	{ "it", roff_it, NULL, NULL, 0, NULL },
	{ "itc", roff_unsupp, NULL, NULL, 0, NULL },
	{ "IX", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "kern", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "kernafter", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "kernbefore", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "kernpair", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "lc", roff_unsupp, NULL, NULL, 0, NULL },
	{ "lc_ctype", roff_unsupp, NULL, NULL, 0, NULL },
	{ "lds", roff_unsupp, NULL, NULL, 0, NULL },
	{ "length", roff_unsupp, NULL, NULL, 0, NULL },
	{ "letadj", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "lf", roff_insec, NULL, NULL, 0, NULL },
	{ "lg", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "lhang", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "linetabs", roff_unsupp, NULL, NULL, 0, NULL },
	{ "lnr", roff_unsupp, NULL, NULL, 0, NULL },
	{ "lnrf", roff_unsupp, NULL, NULL, 0, NULL },
	{ "lpfx", roff_unsupp, NULL, NULL, 0, NULL },
	{ "ls", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "lsm", roff_unsupp, NULL, NULL, 0, NULL },
	{ "lt", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "mc", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "mediasize", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "minss", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "mk", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "mso", roff_insec, NULL, NULL, 0, NULL },
	{ "na", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ne", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "nh", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "nhychar", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "nm", roff_unsupp, NULL, NULL, 0, NULL },
	{ "nn", roff_unsupp, NULL, NULL, 0, NULL },
	{ "nop", roff_unsupp, NULL, NULL, 0, NULL },
	{ "nr", roff_nr, NULL, NULL, 0, NULL },
	{ "nrf", roff_unsupp, NULL, NULL, 0, NULL },
	{ "nroff", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ns", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "nx", roff_insec, NULL, NULL, 0, NULL },
	{ "open", roff_insec, NULL, NULL, 0, NULL },
	{ "opena", roff_insec, NULL, NULL, 0, NULL },
	{ "os", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "output", roff_unsupp, NULL, NULL, 0, NULL },
	{ "padj", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "papersize", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pc", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pev", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pi", roff_insec, NULL, NULL, 0, NULL },
	{ "PI", roff_unsupp, NULL, NULL, 0, NULL },
	{ "pl", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pm", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pn", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pnr", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "po", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ps", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "psbb", roff_unsupp, NULL, NULL, 0, NULL },
	{ "pshape", roff_unsupp, NULL, NULL, 0, NULL },
	{ "pso", roff_insec, NULL, NULL, 0, NULL },
	{ "ptr", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "pvs", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "rchar", roff_unsupp, NULL, NULL, 0, NULL },
	{ "rd", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "recursionlimit", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "return", roff_unsupp, NULL, NULL, 0, NULL },
	{ "rfschar", roff_unsupp, NULL, NULL, 0, NULL },
	{ "rhang", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "rj", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "rm", roff_rm, NULL, NULL, 0, NULL },
	{ "rn", roff_unsupp, NULL, NULL, 0, NULL },
	{ "rnn", roff_unsupp, NULL, NULL, 0, NULL },
	{ "rr", roff_rr, NULL, NULL, 0, NULL },
	{ "rs", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "rt", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "schar", roff_unsupp, NULL, NULL, 0, NULL },
	{ "sentchar", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "shc", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "shift", roff_unsupp, NULL, NULL, 0, NULL },
	{ "sizes", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "so", roff_so, NULL, NULL, 0, NULL },
	{ "spacewidth", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "special", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "spreadwarn", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ss", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "sty", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "substring", roff_unsupp, NULL, NULL, 0, NULL },
	{ "sv", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "sy", roff_insec, NULL, NULL, 0, NULL },
	{ "T&", roff_T_, NULL, NULL, 0, NULL },
	{ "ta", roff_unsupp, NULL, NULL, 0, NULL },
	{ "tc", roff_unsupp, NULL, NULL, 0, NULL },
	{ "TE", roff_TE, NULL, NULL, 0, NULL },
	{ "TH", roff_TH, NULL, NULL, 0, NULL },
	{ "ti", roff_unsupp, NULL, NULL, 0, NULL },
	{ "tkf", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "tl", roff_unsupp, NULL, NULL, 0, NULL },
	{ "tm", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "tm1", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "tmc", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "tr", roff_tr, NULL, NULL, 0, NULL },
	{ "track", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "transchar", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "trf", roff_insec, NULL, NULL, 0, NULL },
	{ "trimat", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "trin", roff_unsupp, NULL, NULL, 0, NULL },
	{ "trnt", roff_unsupp, NULL, NULL, 0, NULL },
	{ "troff", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "TS", roff_TS, NULL, NULL, 0, NULL },
	{ "uf", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "ul", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "unformat", roff_unsupp, NULL, NULL, 0, NULL },
	{ "unwatch", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "unwatchn", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "vpt", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "vs", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "warn", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "warnscale", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "watch", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "watchlength", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "watchn", roff_line_ignore, NULL, NULL, 0, NULL },
	{ "wh", roff_unsupp, NULL, NULL, 0, NULL },
	{ "while", roff_unsupp, NULL, NULL, 0, NULL },
	{ "write", roff_insec, NULL, NULL, 0, NULL },
	{ "writec", roff_insec, NULL, NULL, 0, NULL },
	{ "writem", roff_insec, NULL, NULL, 0, NULL },
	{ "xflag", roff_line_ignore, NULL, NULL, 0, NULL },
	{ ".", roff_cblock, NULL, NULL, 0, NULL },
	{ NULL, roff_userdef, NULL, NULL, 0, NULL },
};

/* not currently implemented: Ds em Eq LP Me PP pp Or Rd Sf SH */
const	char *const __mdoc_reserved[] = {
	"Ac", "Ad", "An", "Ao", "Ap", "Aq", "Ar", "At",
	"Bc", "Bd", "Bf", "Bk", "Bl", "Bo", "Bq",
	"Brc", "Bro", "Brq", "Bsx", "Bt", "Bx",
	"Cd", "Cm", "Db", "Dc", "Dd", "Dl", "Do", "Dq",
	"Dt", "Dv", "Dx", "D1",
	"Ec", "Ed", "Ef", "Ek", "El", "Em",
	"En", "Eo", "Er", "Es", "Ev", "Ex",
	"Fa", "Fc", "Fd", "Fl", "Fn", "Fo", "Fr", "Ft", "Fx",
	"Hf", "Ic", "In", "It", "Lb", "Li", "Lk", "Lp",
	"Ms", "Mt", "Nd", "Nm", "No", "Ns", "Nx",
	"Oc", "Oo", "Op", "Os", "Ot", "Ox",
	"Pa", "Pc", "Pf", "Po", "Pp", "Pq",
	"Qc", "Ql", "Qo", "Qq", "Re", "Rs", "Rv",
	"Sc", "Sh", "Sm", "So", "Sq",
	"Ss", "St", "Sx", "Sy",
	"Ta", "Tn", "Ud", "Ux", "Va", "Vt", "Xc", "Xo", "Xr",
	"%A", "%B", "%C", "%D", "%I", "%J", "%N", "%O",
	"%P", "%Q", "%R", "%T", "%U", "%V",
	NULL
};

/* not currently implemented: BT DE DS ME MT PT SY TQ YS */
const	char *const __man_reserved[] = {
	"AT", "B", "BI", "BR", "DT",
	"EE", "EN", "EQ", "EX", "HP", "I", "IB", "IP", "IR",
	"LP", "OP", "P", "PD", "PP",
	"R", "RB", "RE", "RI", "RS", "SB", "SH", "SM", "SS",
	"TE", "TH", "TP", "TS", "T&", "UC", "UE", "UR",
	NULL
};

/* Array of injected predefined strings. */
#define	PREDEFS_MAX	 38
static	const struct predef predefs[PREDEFS_MAX] = {
#include "predefs.in"
};

/* See roffhash_find() */
#define	ROFF_HASH(p)	(p[0] - ASCII_LO)

static	int	 roffit_lines;  /* number of lines to delay */
static	char	*roffit_macro;  /* nil-terminated macro line */


/* --- request table ------------------------------------------------------ */

static void
roffhash_init(void)
{
	struct roffmac	 *n;
	int		  buc, i;

	for (i = 0; i < (int)ROFF_USERDEF; 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];
	}
}

/*
 * 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
roffhash_find(const char *p, size_t s)
{
	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);

	buc = ROFF_HASH(p);

	if (NULL == (n = hash[buc]))
		return(ROFF_MAX);
	for ( ; n; n = n->next)
		if (0 == strncmp(n->name, p, s) && '\0' == n->name[(int)s])
			return((enum rofft)(n - roffs));

	return(ROFF_MAX);
}

/* --- stack of request blocks -------------------------------------------- */

/*
 * Pop the current node off of the stack of roff instructions currently
 * pending.
 */
static void
roffnode_pop(struct roff *r)
{
	struct roffnode	*p;

	assert(r->last);
	p = r->last;

	r->last = r->last->parent;
	free(p->name);
	free(p->end);
	free(p);
}

/*
 * Push a roff node onto the instruction stack.  This must later be
 * removed with roffnode_pop().
 */
static void
roffnode_push(struct roff *r, enum rofft tok, const char *name,
		int line, int col)
{
	struct roffnode	*p;

	p = mandoc_calloc(1, sizeof(struct roffnode));
	p->tok = tok;
	if (name)
		p->name = mandoc_strdup(name);
	p->parent = r->last;
	p->line = line;
	p->col = col;
	p->rule = p->parent ? p->parent->rule : 0;

	r->last = p;
}

/* --- roff parser state data management ---------------------------------- */

static void
roff_free1(struct roff *r)
{
	struct tbl_node	*tbl;
	struct eqn_node	*e;
	int		 i;

	while (NULL != (tbl = r->first_tbl)) {
		r->first_tbl = tbl->next;
		tbl_free(tbl);
	}
	r->first_tbl = r->last_tbl = r->tbl = NULL;

	while (NULL != (e = r->first_eqn)) {
		r->first_eqn = e->next;
		eqn_free(e);
	}
	r->first_eqn = r->last_eqn = r->eqn = NULL;

	while (r->last)
		roffnode_pop(r);

	free (r->rstack);
	r->rstack = NULL;
	r->rstacksz = 0;
	r->rstackpos = -1;

	roff_freereg(r->regtab);
	r->regtab = NULL;

	roff_freestr(r->strtab);
	roff_freestr(r->xmbtab);
	r->strtab = r->xmbtab = NULL;

	if (r->xtab)
		for (i = 0; i < 128; i++)
			free(r->xtab[i].p);
	free(r->xtab);
	r->xtab = NULL;
}

void
roff_reset(struct roff *r)
{

	roff_free1(r);
	r->format = r->options & (MPARSE_MDOC | MPARSE_MAN);
	r->control = 0;
}

void
roff_free(struct roff *r)
{

	roff_free1(r);
	free(r);
}

struct roff *
roff_alloc(struct mparse *parse, const struct mchars *mchars, int options)
{
	struct roff	*r;

	r = mandoc_calloc(1, sizeof(struct roff));
	r->parse = parse;
	r->mchars = mchars;
	r->options = options;
	r->format = options & (MPARSE_MDOC | MPARSE_MAN);
	r->rstackpos = -1;

	roffhash_init();

	return(r);
}

/* --- syntax tree state data management ---------------------------------- */

static void
roff_man_free1(struct roff_man *man)
{

	if (man->first != NULL)
		roff_node_delete(man, man->first);
	free(man->meta.msec);
	free(man->meta.vol);
	free(man->meta.os);
	free(man->meta.arch);
	free(man->meta.title);
	free(man->meta.name);
	free(man->meta.date);
}

static void
roff_man_alloc1(struct roff_man *man)
{

	memset(&man->meta, 0, sizeof(man->meta));
	man->first = mandoc_calloc(1, sizeof(*man->first));
	man->first->type = ROFFT_ROOT;
	man->last = man->first;
	man->last_es = NULL;
	man->flags = 0;
	man->macroset = MACROSET_NONE;
	man->lastsec = man->lastnamed = SEC_NONE;
	man->next = ROFF_NEXT_CHILD;
}

void
roff_man_reset(struct roff_man *man)
{

	roff_man_free1(man);
	roff_man_alloc1(man);
}

void
roff_man_free(struct roff_man *man)
{

	roff_man_free1(man);
	free(man);
}

struct roff_man *
roff_man_alloc(struct roff *roff, struct mparse *parse,
	const char *defos, int quick)
{
	struct roff_man *man;

	man = mandoc_calloc(1, sizeof(*man));
	man->parse = parse;
	man->roff = roff;
	man->defos = defos;
	man->quick = quick;
	roff_man_alloc1(man);
	return(man);
}

/* --- syntax tree handling ----------------------------------------------- */

struct roff_node *
roff_node_alloc(struct roff_man *man, int line, int pos,
	enum roff_type type, int tok)
{
	struct roff_node	*n;

	n = mandoc_calloc(1, sizeof(*n));
	n->line = line;
	n->pos = pos;
	n->tok = tok;
	n->type = type;
	n->sec = man->lastsec;

	if (man->flags & MDOC_SYNOPSIS)
		n->flags |= MDOC_SYNPRETTY;
	else
		n->flags &= ~MDOC_SYNPRETTY;
	if (man->flags & MDOC_NEWLINE)
		n->flags |= MDOC_LINE;
	man->flags &= ~MDOC_NEWLINE;

	return(n);
}

void
roff_node_append(struct roff_man *man, struct roff_node *n)
{

	switch (man->next) {
	case ROFF_NEXT_SIBLING:
		man->last->next = n;
		n->prev = man->last;
		n->parent = man->last->parent;
		break;
	case ROFF_NEXT_CHILD:
		man->last->child = n;
		n->parent = man->last;
		break;
	default:
		abort();
		/* NOTREACHED */
	}
	n->parent->nchild++;

	/*
	 * Copy over the normalised-data pointer of our parent.  Not
	 * everybody has one, but copying a null pointer is fine.
	 */

	switch (n->type) {
	case ROFFT_BODY:
		if (n->end != ENDBODY_NOT)
			break;
		/* FALLTHROUGH */
	case ROFFT_TAIL:
		/* FALLTHROUGH */
	case ROFFT_HEAD:
		n->norm = n->parent->norm;
		break;
	default:
		break;
	}

	if (man->macroset == MACROSET_MDOC)
		mdoc_valid_pre(man, n);

	switch (n->type) {
	case ROFFT_HEAD:
		assert(n->parent->type == ROFFT_BLOCK);
		n->parent->head = n;
		break;
	case ROFFT_BODY:
		if (n->end)
			break;
		assert(n->parent->type == ROFFT_BLOCK);
		n->parent->body = n;
		break;
	case ROFFT_TAIL:
		assert(n->parent->type == ROFFT_BLOCK);
		n->parent->tail = n;
		break;
	default:
		break;
	}
	man->last = n;
}

void
roff_word_alloc(struct roff_man *man, int line, int pos, const char *word)
{
	struct roff_node	*n;

	n = roff_node_alloc(man, line, pos, ROFFT_TEXT, TOKEN_NONE);
	n->string = roff_strdup(man->roff, word);
	roff_node_append(man, n);
	if (man->macroset == MACROSET_MDOC)
		mdoc_valid_post(man);
	else
		man_valid_post(man);
	man->next = ROFF_NEXT_SIBLING;
}

void
roff_word_append(struct roff_man *man, const char *word)
{
	struct roff_node	*n;
	char			*addstr, *newstr;

	n = man->last;
	addstr = roff_strdup(man->roff, word);
	mandoc_asprintf(&newstr, "%s %s", n->string, addstr);
	free(addstr);
	free(n->string);
	n->string = newstr;
	man->next = ROFF_NEXT_SIBLING;
}

void
roff_elem_alloc(struct roff_man *man, int line, int pos, int tok)
{
	struct roff_node	*n;

	n = roff_node_alloc(man, line, pos, ROFFT_ELEM, tok);
	roff_node_append(man, n);
	man->next = ROFF_NEXT_CHILD;
}

struct roff_node *
roff_block_alloc(struct roff_man *man, int line, int pos, int tok)
{
	struct roff_node	*n;

	n = roff_node_alloc(man, line, pos, ROFFT_BLOCK, tok);
	roff_node_append(man, n);
	man->next = ROFF_NEXT_CHILD;
	return(n);
}

struct roff_node *
roff_head_alloc(struct roff_man *man, int line, int pos, int tok)
{
	struct roff_node	*n;

	n = roff_node_alloc(man, line, pos, ROFFT_HEAD, tok);
	roff_node_append(man, n);
	man->next = ROFF_NEXT_CHILD;
	return(n);
}

struct roff_node *
roff_body_alloc(struct roff_man *man, int line, int pos, int tok)
{
	struct roff_node	*n;

	n = roff_node_alloc(man, line, pos, ROFFT_BODY, tok);
	roff_node_append(man, n);
	man->next = ROFF_NEXT_CHILD;
	return(n);
}

void
roff_addeqn(struct roff_man *man, const struct eqn *eqn)
{
	struct roff_node	*n;

	n = roff_node_alloc(man, eqn->ln, eqn->pos, ROFFT_EQN, TOKEN_NONE);
	n->eqn = eqn;
	if (eqn->ln > man->last->line)
		n->flags |= MDOC_LINE;
	roff_node_append(man, n);
	man->next = ROFF_NEXT_SIBLING;
}

void
roff_addtbl(struct roff_man *man, const struct tbl_span *tbl)
{
	struct roff_node	*n;

	if (man->macroset == MACROSET_MAN)
		man_breakscope(man, TOKEN_NONE);
	n = roff_node_alloc(man, tbl->line, 0, ROFFT_TBL, TOKEN_NONE);
	n->span = tbl;
	roff_node_append(man, n);
	if (man->macroset == MACROSET_MDOC)
		mdoc_valid_post(man);
	else
		man_valid_post(man);
	man->next = ROFF_NEXT_SIBLING;
}

void
roff_node_unlink(struct roff_man *man, struct roff_node *n)
{

	/* Adjust siblings. */

	if (n->prev)
		n->prev->next = n->next;
	if (n->next)
		n->next->prev = n->prev;

	/* Adjust parent. */

	if (n->parent != NULL) {
		n->parent->nchild--;
		if (n->parent->child == n)
			n->parent->child = n->next;
		if (n->parent->last == n)
			n->parent->last = n->prev;
	}

	/* Adjust parse point. */

	if (man == NULL)
		return;
	if (man->last == n) {
		if (n->prev == NULL) {
			man->last = n->parent;
			man->next = ROFF_NEXT_CHILD;
		} else {
			man->last = n->prev;
			man->next = ROFF_NEXT_SIBLING;
		}
	}
	if (man->first == n)
		man->first = NULL;
}

void
roff_node_free(struct roff_node *n)
{

	if (n->args != NULL)
		mdoc_argv_free(n->args);
	if (n->type == ROFFT_BLOCK || n->type == ROFFT_ELEM)
		free(n->norm);
	free(n->string);
	free(n);
}

void
roff_node_delete(struct roff_man *man, struct roff_node *n)
{

	while (n->child != NULL)
		roff_node_delete(man, n->child);
	assert(n->nchild == 0);
	roff_node_unlink(man, n);
	roff_node_free(n);
}

void
deroff(char **dest, const struct roff_node *n)
{
	char	*cp;
	size_t	 sz;

	if (n->type != ROFFT_TEXT) {
		for (n = n->child; n != NULL; n = n->next)
			deroff(dest, n);
		return;
	}

	/* Skip leading whitespace and escape sequences. */

	cp = n->string;
	while (*cp != '\0') {
		if ('\\' == *cp) {
			cp++;
			mandoc_escape((const char **)&cp, NULL, NULL);
		} else if (isspace((unsigned char)*cp))
			cp++;
		else
			break;
	}

	/* Skip trailing whitespace. */

	for (sz = strlen(cp); sz; sz--)
		if ( ! isspace((unsigned char)cp[sz-1]))
			break;

	/* Skip empty strings. */

	if (sz == 0)
		return;

	if (*dest == NULL) {
		*dest = mandoc_strndup(cp, sz);
		return;
	}

	mandoc_asprintf(&cp, "%s %*s", *dest, (int)sz, cp);
	free(*dest);
	*dest = cp;
}

/* --- main functions of the roff parser ---------------------------------- */

/*
 * In the current line, expand escape sequences that tend to get
 * used in numerical expressions and conditional requests.
 * Also check the syntax of the remaining escape sequences.
 */
static enum rofferr
roff_res(struct roff *r, struct buf *buf, int ln, int pos)
{
	char		 ubuf[24]; /* buffer to print the number */
	const char	*start;	/* start of the string to process */
	char		*stesc;	/* start of an escape sequence ('\\') */
	const char	*stnam;	/* start of the name, after "[(*" */
	const char	*cp;	/* end of the name, e.g. before ']' */
	const char	*res;	/* the string to be substituted */
	char		*nbuf;	/* new buffer to copy buf->buf to */
	size_t		 maxl;  /* expected length of the escape name */
	size_t		 naml;	/* actual length of the escape name */
	enum mandoc_esc	 esc;	/* type of the escape sequence */
	int		 inaml;	/* length returned from mandoc_escape() */
	int		 expand_count;	/* to avoid infinite loops */
	int		 npos;	/* position in numeric expression */
	int		 arg_complete; /* argument not interrupted by eol */
	char		 term;	/* character terminating the escape */

	expand_count = 0;
	start = buf->buf + pos;
	stesc = strchr(start, '\0') - 1;
	while (stesc-- > start) {

		/* Search backwards for the next backslash. */

		if (*stesc != '\\')
			continue;

		/* If it is escaped, skip it. */

		for (cp = stesc - 1; cp >= start; cp--)
			if (*cp != '\\')
				break;

		if ((stesc - cp) % 2 == 0) {
			stesc = (char *)cp;
			continue;
		}

		/* Decide whether to expand or to check only. */

		term = '\0';
		cp = stesc + 1;
		switch (*cp) {
		case '*':
			res = NULL;
			break;
		case 'B':
			/* FALLTHROUGH */
		case 'w':
			term = cp[1];
			/* FALLTHROUGH */
		case 'n':
			res = ubuf;
			break;
		default:
			esc = mandoc_escape(&cp, &stnam, &inaml);
			if (esc == ESCAPE_ERROR ||
			    (esc == ESCAPE_SPECIAL &&
			     mchars_spec2cp(r->mchars, stnam, inaml) < 0))
				mandoc_vmsg(MANDOCERR_ESC_BAD,
				    r->parse, ln, (int)(stesc - buf->buf),
				    "%.*s", (int)(cp - stesc), stesc);
			continue;
		}

		if (EXPAND_LIMIT < ++expand_count) {
			mandoc_msg(MANDOCERR_ROFFLOOP, r->parse,
			    ln, (int)(stesc - buf->buf), NULL);
			return(ROFF_IGN);
		}

		/*
		 * The third character decides the length
		 * of the name of the string or register.
		 * Save a pointer to the name.
		 */

		if (term == '\0') {
			switch (*++cp) {
			case '\0':
				maxl = 0;
				break;
			case '(':
				cp++;
				maxl = 2;
				break;
			case '[':
				cp++;
				term = ']';
				maxl = 0;
				break;
			default:
				maxl = 1;
				break;
			}
		} else {
			cp += 2;
			maxl = 0;
		}
		stnam = cp;

		/* Advance to the end of the name. */

		naml = 0;
		arg_complete = 1;
		while (maxl == 0 || naml < maxl) {
			if (*cp == '\0') {
				mandoc_msg(MANDOCERR_ESC_BAD, r->parse,
				    ln, (int)(stesc - buf->buf), stesc);
				arg_complete = 0;
				break;
			}
			if (maxl == 0 && *cp == term) {
				cp++;
				break;
			}
			if (*cp++ != '\\' || stesc[1] != 'w') {
				naml++;
				continue;
			}
			switch (mandoc_escape(&cp, NULL, NULL)) {
			case ESCAPE_SPECIAL:
				/* FALLTHROUGH */
			case ESCAPE_UNICODE:
				/* FALLTHROUGH */
			case ESCAPE_NUMBERED:
				/* FALLTHROUGH */
			case ESCAPE_OVERSTRIKE:
				naml++;
				break;
			default:
				break;
			}
		}

		/*
		 * Retrieve the replacement string; if it is
		 * undefined, resume searching for escapes.
		 */

		switch (stesc[1]) {
		case '*':
			if (arg_complete)
				res = roff_getstrn(r, stnam, naml);
			break;
		case 'B':
			npos = 0;
			ubuf[0] = arg_complete &&
			    roff_evalnum(r, ln, stnam, &npos,
			      NULL, ROFFNUM_SCALE) &&
			    stnam + npos + 1 == cp ? '1' : '0';
			ubuf[1] = '\0';
			break;
		case 'n':
			if (arg_complete)
				(void)snprintf(ubuf, sizeof(ubuf), "%d",
				    roff_getregn(r, stnam, naml));
			else
				ubuf[0] = '\0';
			break;
		case 'w':
			/* use even incomplete args */
			(void)snprintf(ubuf, sizeof(ubuf), "%d",
			    24 * (int)naml);
			break;
		}

		if (res == NULL) {
			mandoc_vmsg(MANDOCERR_STR_UNDEF,
			    r->parse, ln, (int)(stesc - buf->buf),
			    "%.*s", (int)naml, stnam);
			res = "";
		} else if (buf->sz + strlen(res) > SHRT_MAX) {
			mandoc_msg(MANDOCERR_ROFFLOOP, r->parse,
			    ln, (int)(stesc - buf->buf), NULL);
			return(ROFF_IGN);
		}

		/* Replace the escape sequence by the string. */

		*stesc = '\0';
		buf->sz = mandoc_asprintf(&nbuf, "%s%s%s",
		    buf->buf, res, cp) + 1;

		/* Prepare for the next replacement. */

		start = nbuf + pos;
		stesc = nbuf + (stesc - buf->buf) + strlen(res);
		free(buf->buf);
		buf->buf = nbuf;
	}
	return(ROFF_CONT);
}

/*
 * Process text streams:
 * Convert all breakable hyphens into ASCII_HYPH.
 * Decrement and spring input line trap.
 */
static enum rofferr
roff_parsetext(struct buf *buf, int pos, int *offs)
{
	size_t		 sz;
	const char	*start;
	char		*p;
	int		 isz;
	enum mandoc_esc	 esc;

	start = p = buf->buf + pos;

	while (*p != '\0') {
		sz = strcspn(p, "-\\");
		p += sz;

		if (*p == '\0')
			break;

		if (*p == '\\') {
			/* Skip over escapes. */
			p++;
			esc = mandoc_escape((const char **)&p, NULL, NULL);
			if (esc == ESCAPE_ERROR)
				break;
			while (*p == '-')
				p++;
			continue;
		} else if (p == start) {
			p++;
			continue;
		}

		if (isalpha((unsigned char)p[-1]) &&
		    isalpha((unsigned char)p[1]))
			*p = ASCII_HYPH;
		p++;
	}

	/* Spring the input line trap. */
	if (roffit_lines == 1) {
		isz = mandoc_asprintf(&p, "%s\n.%s", buf->buf, roffit_macro);
		free(buf->buf);
		buf->buf = p;
		buf->sz = isz + 1;
		*offs = 0;
		free(roffit_macro);
		roffit_lines = 0;
		return(ROFF_REPARSE);
	} else if (roffit_lines > 1)
		--roffit_lines;
	return(ROFF_CONT);
}

enum rofferr
roff_parseln(struct roff *r, int ln, struct buf *buf, int *offs)
{
	enum rofft	 t;
	enum rofferr	 e;
	int		 pos;	/* parse point */
	int		 spos;	/* saved parse point for messages */
	int		 ppos;	/* original offset in buf->buf */
	int		 ctl;	/* macro line (boolean) */

	ppos = pos = *offs;

	/* Handle in-line equation delimiters. */

	if (r->tbl == NULL &&
	    r->last_eqn != NULL && r->last_eqn->delim &&
	    (r->eqn == NULL || r->eqn_inline)) {
		e = roff_eqndelim(r, buf, pos);
		if (e == ROFF_REPARSE)
			return(e);
		assert(e == ROFF_CONT);
	}

	/* Expand some escape sequences. */

	e = roff_res(r, buf, ln, pos);
	if (e == ROFF_IGN)
		return(e);
	assert(e == ROFF_CONT);

	ctl = roff_getcontrol(r, buf->buf, &pos);

	/*
	 * First, if a scope is open and we're not a macro, pass the
	 * text through the macro's filter.
	 * Equations process all content themselves.
	 * Tables process almost all content themselves, but we want
	 * to warn about macros before passing it there.
	 */

	if (r->last != NULL && ! ctl) {
		t = r->last->tok;
		assert(roffs[t].text);
		e = (*roffs[t].text)(r, t, buf, ln, pos, pos, offs);
		assert(e == ROFF_IGN || e == ROFF_CONT);
		if (e != ROFF_CONT)
			return(e);
	}
	if (r->eqn != NULL)
		return(eqn_read(&r->eqn, ln, buf->buf, ppos, offs));
	if (r->tbl != NULL && ( ! ctl || buf->buf[pos] == '\0'))
		return(tbl_read(r->tbl, ln, buf->buf, ppos));
	if ( ! ctl)
		return(roff_parsetext(buf, pos, offs));

	/* Skip empty request lines. */

	if (buf->buf[pos] == '"') {
		mandoc_msg(MANDOCERR_COMMENT_BAD, r->parse,
		    ln, pos, NULL);
		return(ROFF_IGN);
	} else if (buf->buf[pos] == '\0')
		return(ROFF_IGN);

	/*
	 * If a scope is open, go to the child handler for that macro,
	 * as it may want to preprocess before doing anything with it.
	 * Don't do so if an equation is open.
	 */

	if (r->last) {
		t = r->last->tok;
		assert(roffs[t].sub);
		return((*roffs[t].sub)(r, t, buf, ln, ppos, pos, offs));
	}

	/* No scope is open.  This is a new request or macro. */

	spos = pos;
	t = roff_parse(r, buf->buf, &pos, ln, ppos);

	/* Tables ignore most macros. */

	if (r->tbl != NULL && (t == ROFF_MAX || t == ROFF_TS)) {
		mandoc_msg(MANDOCERR_TBLMACRO, r->parse,
		    ln, pos, buf->buf + spos);
		if (t == ROFF_TS)
			return(ROFF_IGN);
		while (buf->buf[pos] != '\0' && buf->buf[pos] != ' ')
			pos++;
		while (buf->buf[pos] != '\0' && buf->buf[pos] == ' ')
			pos++;
		return(tbl_read(r->tbl, ln, buf->buf, pos));
	}

	/*
	 * This is neither a roff request nor a user-defined macro.
	 * Let the standard macro set parsers handle it.
	 */

	if (t == ROFF_MAX)
		return(ROFF_CONT);

	/* Execute a roff request or a user defined macro. */

	assert(roffs[t].proc);
	return((*roffs[t].proc)(r, t, buf, ln, ppos, pos, offs));
}

void
roff_endparse(struct roff *r)
{

	if (r->last)
		mandoc_msg(MANDOCERR_BLK_NOEND, r->parse,
		    r->last->line, r->last->col,
		    roffs[r->last->tok].name);

	if (r->eqn) {
		mandoc_msg(MANDOCERR_BLK_NOEND, r->parse,
		    r->eqn->eqn.ln, r->eqn->eqn.pos, "EQ");
		eqn_end(&r->eqn);
	}

	if (r->tbl) {
		mandoc_msg(MANDOCERR_BLK_NOEND, r->parse,
		    r->tbl->line, r->tbl->pos, "TS");
		tbl_end(&r->tbl);
	}
}

/*
 * 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(struct roff *r, char *buf, int *pos, int ln, int ppos)
{
	char		*cp;
	const char	*mac;
	size_t		 maclen;
	enum rofft	 t;

	cp = buf + *pos;

	if ('\0' == *cp || '"' == *cp || '\t' == *cp || ' ' == *cp)
		return(ROFF_MAX);

	mac = cp;
	maclen = roff_getname(r, &cp, ln, ppos);

	t = (r->current_string = roff_getstrn(r, mac, maclen))
	    ? ROFF_USERDEF : roffhash_find(mac, maclen);

	if (ROFF_MAX != t)
		*pos = cp - buf;

	return(t);
}

/* --- handling of request blocks ----------------------------------------- */

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 (r->last == NULL) {
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "..");
		return(ROFF_IGN);
	}

	switch (r->last->tok) {
	case ROFF_am:
		/* ROFF_am1 is remapped to ROFF_am in roff_block(). */
		/* FALLTHROUGH */
	case ROFF_ami:
		/* FALLTHROUGH */
	case ROFF_de:
		/* ROFF_de1 is remapped to ROFF_de in roff_block(). */
		/* FALLTHROUGH */
	case ROFF_dei:
		/* FALLTHROUGH */
	case ROFF_ig:
		break;
	default:
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "..");
		return(ROFF_IGN);
	}

	if (buf->buf[pos] != '\0')
		mandoc_vmsg(MANDOCERR_ARG_SKIP, r->parse, ln, pos,
		    ".. %s", buf->buf + pos);

	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);
	}
}

static void
roff_ccond(struct roff *r, int ln, int ppos)
{

	if (NULL == r->last) {
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "\\}");
		return;
	}

	switch (r->last->tok) {
	case ROFF_el:
		/* FALLTHROUGH */
	case ROFF_ie:
		/* FALLTHROUGH */
	case ROFF_if:
		break;
	default:
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "\\}");
		return;
	}

	if (r->last->endspan > -1) {
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "\\}");
		return;
	}

	roffnode_pop(r);
	roffnode_cleanscope(r);
	return;
}

static enum rofferr
roff_block(ROFF_ARGS)
{
	const char	*name;
	char		*iname, *cp;
	size_t		 namesz;

	/* Ignore groff compatibility mode for now. */

	if (tok == ROFF_de1)
		tok = ROFF_de;
	else if (tok == ROFF_dei1)
		tok = ROFF_dei;
	else if (tok == ROFF_am1)
		tok = ROFF_am;
	else if (tok == ROFF_ami1)
		tok = ROFF_ami;

	/* Parse the macro name argument. */

	cp = buf->buf + pos;
	if (tok == ROFF_ig) {
		iname = NULL;
		namesz = 0;
	} else {
		iname = cp;
		namesz = roff_getname(r, &cp, ln, ppos);
		iname[namesz] = '\0';
	}

	/* Resolve the macro name argument if it is indirect. */

	if (namesz && (tok == ROFF_dei || tok == ROFF_ami)) {
		if ((name = roff_getstrn(r, iname, namesz)) == NULL) {
			mandoc_vmsg(MANDOCERR_STR_UNDEF,
			    r->parse, ln, (int)(iname - buf->buf),
			    "%.*s", (int)namesz, iname);
			namesz = 0;
		} else
			namesz = strlen(name);
	} else
		name = iname;

	if (namesz == 0 && tok != ROFF_ig) {
		mandoc_msg(MANDOCERR_REQ_EMPTY, r->parse,
		    ln, ppos, roffs[tok].name);
		return(ROFF_IGN);
	}

	roffnode_push(r, tok, name, ln, ppos);

	/*
	 * At the beginning of a `de' macro, clear the existing string
	 * with the same name, if there is one.  New content will be
	 * appended from roff_block_text() in multiline mode.
	 */

	if (tok == ROFF_de || tok == ROFF_dei)
		roff_setstrn(&r->strtab, name, namesz, "", 0, 0);

	if (*cp == '\0')
		return(ROFF_IGN);

	/* Get the custom end marker. */

	iname = cp;
	namesz = roff_getname(r, &cp, ln, ppos);

	/* Resolve the end marker if it is indirect. */

	if (namesz && (tok == ROFF_dei || tok == ROFF_ami)) {
		if ((name = roff_getstrn(r, iname, namesz)) == NULL) {
			mandoc_vmsg(MANDOCERR_STR_UNDEF,
			    r->parse, ln, (int)(iname - buf->buf),
			    "%.*s", (int)namesz, iname);
			namesz = 0;
		} else
			namesz = strlen(name);
	} else
		name = iname;

	if (namesz)
		r->last->end = mandoc_strndup(name, namesz);

	if (*cp != '\0')
		mandoc_vmsg(MANDOCERR_ARG_EXCESS, r->parse,
		    ln, pos, ".%s ... %s", roffs[tok].name, cp);

	return(ROFF_IGN);
}

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) {
		for (i = pos, j = 0; r->last->end[j]; j++, i++)
			if (buf->buf[i] != r->last->end[j])
				break;

		if (r->last->end[j] == '\0' &&
		    (buf->buf[i] == '\0' ||
		     buf->buf[i] == ' ' ||
		     buf->buf[i] == '\t')) {
			roffnode_pop(r);
			roffnode_cleanscope(r);

			while (buf->buf[i] == ' ' || buf->buf[i] == '\t')
				i++;

			pos = i;
			if (roff_parse(r, buf->buf, &pos, ln, ppos) !=
			    ROFF_MAX)
				return(ROFF_RERUN);
			return(ROFF_IGN);
		}
	}

	/*
	 * If we have no custom end-query or lookup failed, then try
	 * pulling it out of the hashtable.
	 */

	t = roff_parse(r, buf->buf, &pos, ln, ppos);

	if (t != ROFF_cblock) {
		if (tok != ROFF_ig)
			roff_setstr(r, r->last->name, buf->buf + ppos, 2);
		return(ROFF_IGN);
	}

	assert(roffs[t].proc);
	return((*roffs[t].proc)(r, t, buf, ln, ppos, pos, offs));
}

static enum rofferr
roff_block_text(ROFF_ARGS)
{

	if (tok != ROFF_ig)
		roff_setstr(r, r->last->name, buf->buf + pos, 2);

	return(ROFF_IGN);
}

static enum rofferr
roff_cond_sub(ROFF_ARGS)
{
	enum rofft	 t;
	char		*ep;
	int		 rr;

	rr = r->last->rule;
	roffnode_cleanscope(r);
	t = roff_parse(r, buf->buf, &pos, ln, ppos);

	/*
	 * Fully handle known macros when they are structurally
	 * required or when the conditional evaluated to true.
	 */

	if ((t != ROFF_MAX) &&
	    (rr || roffs[t].flags & ROFFMAC_STRUCT)) {
		assert(roffs[t].proc);
		return((*roffs[t].proc)(r, t, buf, ln, ppos, pos, offs));
	}

	/*
	 * If `\}' occurs on a macro line without a preceding macro,
	 * drop the line completely.
	 */

	ep = buf->buf + pos;
	if (ep[0] == '\\' && ep[1] == '}')
		rr = 0;

	/* Always check for the closing delimiter `\}'. */

	while ((ep = strchr(ep, '\\')) != NULL) {
		if (*(++ep) == '}') {
			*ep = '&';
			roff_ccond(r, ln, ep - buf->buf - 1);
		}
		if (*ep != '\0')
			++ep;
	}
	return(rr ? ROFF_CONT : ROFF_IGN);
}

static enum rofferr
roff_cond_text(ROFF_ARGS)
{
	char		*ep;
	int		 rr;

	rr = r->last->rule;
	roffnode_cleanscope(r);

	ep = buf->buf + pos;
	while ((ep = strchr(ep, '\\')) != NULL) {
		if (*(++ep) == '}') {
			*ep = '&';
			roff_ccond(r, ln, ep - buf->buf - 1);
		}
		if (*ep != '\0')
			++ep;
	}
	return(rr ? ROFF_CONT : ROFF_IGN);
}

/* --- handling of numeric and conditional expressions -------------------- */

/*
 * Parse a single signed integer number.  Stop at the first non-digit.
 * If there is at least one digit, return success and advance the
 * parse point, else return failure and let the parse point unchanged.
 * Ignore overflows, treat them just like the C language.
 */
static int
roff_getnum(const char *v, int *pos, int *res, int flags)
{
	int	 myres, scaled, n, p;

	if (NULL == res)
		res = &myres;

	p = *pos;
	n = v[p] == '-';
	if (n || v[p] == '+')
		p++;

	if (flags & ROFFNUM_WHITE)
		while (isspace((unsigned char)v[p]))
			p++;

	for (*res = 0; isdigit((unsigned char)v[p]); p++)
		*res = 10 * *res + v[p] - '0';
	if (p == *pos + n)
		return 0;

	if (n)
		*res = -*res;

	/* Each number may be followed by one optional scaling unit. */

	switch (v[p]) {
	case 'f':
		scaled = *res * 65536;
		break;
	case 'i':
		scaled = *res * 240;
		break;
	case 'c':
		scaled = *res * 240 / 2.54;
		break;
	case 'v':
		/* FALLTROUGH */
	case 'P':
		scaled = *res * 40;
		break;
	case 'm':
		/* FALLTROUGH */
	case 'n':
		scaled = *res * 24;
		break;
	case 'p':
		scaled = *res * 10 / 3;
		break;
	case 'u':
		scaled = *res;
		break;
	case 'M':
		scaled = *res * 6 / 25;
		break;
	default:
		scaled = *res;
		p--;
		break;
	}
	if (flags & ROFFNUM_SCALE)
		*res = scaled;

	*pos = p + 1;
	return(1);
}

/*
 * Evaluate a string comparison condition.
 * The first character is the delimiter.
 * Succeed if the string up to its second occurrence
 * matches the string up to its third occurence.
 * Advance the cursor after the third occurrence
 * or lacking that, to the end of the line.
 */
static int
roff_evalstrcond(const char *v, int *pos)
{
	const char	*s1, *s2, *s3;
	int		 match;

	match = 0;
	s1 = v + *pos;		/* initial delimiter */
	s2 = s1 + 1;		/* for scanning the first string */
	s3 = strchr(s2, *s1);	/* for scanning the second string */

	if (NULL == s3)		/* found no middle delimiter */
		goto out;

	while ('\0' != *++s3) {
		if (*s2 != *s3) {  /* mismatch */
			s3 = strchr(s3, *s1);
			break;
		}
		if (*s3 == *s1) {  /* found the final delimiter */
			match = 1;
			break;
		}
		s2++;
	}

out:
	if (NULL == s3)
		s3 = strchr(s2, '\0');
	else if (*s3 != '\0')
		s3++;
	*pos = s3 - v;
	return(match);
}

/*
 * Evaluate an optionally negated single character, numerical,
 * or string condition.
 */
static int
roff_evalcond(struct roff *r, int ln, const char *v, int *pos)
{
	int	 number, savepos, wanttrue;

	if ('!' == v[*pos]) {
		wanttrue = 0;
		(*pos)++;
	} else
		wanttrue = 1;

	switch (v[*pos]) {
	case '\0':
		return(0);
	case 'n':
		/* FALLTHROUGH */
	case 'o':
		(*pos)++;
		return(wanttrue);
	case 'c':
		/* FALLTHROUGH */
	case 'd':
		/* FALLTHROUGH */
	case 'e':
		/* FALLTHROUGH */
	case 'r':
		/* FALLTHROUGH */
	case 't':
		/* FALLTHROUGH */
	case 'v':
		(*pos)++;
		return(!wanttrue);
	default:
		break;
	}

	savepos = *pos;
	if (roff_evalnum(r, ln, v, pos, &number, ROFFNUM_SCALE))
		return((number > 0) == wanttrue);
	else if (*pos == savepos)
		return(roff_evalstrcond(v, pos) == wanttrue);
	else
		return (0);
}

static enum rofferr
roff_line_ignore(ROFF_ARGS)
{

	return(ROFF_IGN);
}

static enum rofferr
roff_insec(ROFF_ARGS)
{

	mandoc_msg(MANDOCERR_REQ_INSEC, r->parse,
	    ln, ppos, roffs[tok].name);
	return(ROFF_IGN);
}

static enum rofferr
roff_unsupp(ROFF_ARGS)
{

	mandoc_msg(MANDOCERR_REQ_UNSUPP, r->parse,
	    ln, ppos, roffs[tok].name);
	return(ROFF_IGN);
}

static enum rofferr
roff_cond(ROFF_ARGS)
{

	roffnode_push(r, tok, NULL, ln, ppos);

	/*
	 * An `.el' has no conditional body: it will consume the value
	 * of the current rstack entry set in prior `ie' calls or
	 * defaults to DENY.
	 *
	 * If we're not an `el', however, then evaluate the conditional.
	 */

	r->last->rule = tok == ROFF_el ?
	    (r->rstackpos < 0 ? 0 : r->rstack[r->rstackpos--]) :
	    roff_evalcond(r, ln, buf->buf, &pos);

	/*
	 * An if-else will put the NEGATION of the current evaluated
	 * conditional into the stack of rules.
	 */

	if (tok == ROFF_ie) {
		if (r->rstackpos + 1 == r->rstacksz) {
			r->rstacksz += 16;
			r->rstack = mandoc_reallocarray(r->rstack,
			    r->rstacksz, sizeof(int));
		}
		r->rstack[++r->rstackpos] = !r->last->rule;
	}

	/* If the parent has false as its rule, then so do we. */

	if (r->last->parent && !r->last->parent->rule)
		r->last->rule = 0;

	/*
	 * Determine scope.
	 * If there is nothing on the line after the conditional,
	 * not even whitespace, use next-line scope.
	 */

	if (buf->buf[pos] == '\0') {
		r->last->endspan = 2;
		goto out;
	}

	while (buf->buf[pos] == ' ')
		pos++;

	/* An opening brace requests multiline scope. */

	if (buf->buf[pos] == '\\' && buf->buf[pos + 1] == '{') {
		r->last->endspan = -1;
		pos += 2;
		goto out;
	}

	/*
	 * Anything else following the conditional causes
	 * single-line scope.  Warn if the scope contains
	 * nothing but trailing whitespace.
	 */

	if (buf->buf[pos] == '\0')
		mandoc_msg(MANDOCERR_COND_EMPTY, r->parse,
		    ln, ppos, roffs[tok].name);

	r->last->endspan = 1;

out:
	*offs = pos;
	return(ROFF_RERUN);
}

static enum rofferr
roff_ds(ROFF_ARGS)
{
	char		*string;
	const char	*name;
	size_t		 namesz;

	/* Ignore groff compatibility mode for now. */

	if (tok == ROFF_ds1)
		tok = ROFF_ds;
	else if (tok == ROFF_as1)
		tok = ROFF_as;

	/*
	 * The first word is the name of the string.
	 * If it is empty or terminated by an escape sequence,
	 * abort the `ds' request without defining anything.
	 */

	name = string = buf->buf + pos;
	if (*name == '\0')
		return(ROFF_IGN);

	namesz = roff_getname(r, &string, ln, pos);
	if (name[namesz] == '\\')
		return(ROFF_IGN);

	/* Read past the initial double-quote, if any. */
	if (*string == '"')
		string++;

	/* The rest is the value. */
	roff_setstrn(&r->strtab, name, namesz, string, strlen(string),
	    ROFF_as == tok);
	return(ROFF_IGN);
}

/*
 * Parse a single operator, one or two characters long.
 * If the operator is recognized, return success and advance the
 * parse point, else return failure and let the parse point unchanged.
 */
static int
roff_getop(const char *v, int *pos, char *res)
{

	*res = v[*pos];

	switch (*res) {
	case '+':
		/* FALLTHROUGH */
	case '-':
		/* FALLTHROUGH */
	case '*':
		/* FALLTHROUGH */
	case '/':
		/* FALLTHROUGH */
	case '%':
		/* FALLTHROUGH */
	case '&':
		/* FALLTHROUGH */
	case ':':
		break;
	case '<':
		switch (v[*pos + 1]) {
		case '=':
			*res = 'l';
			(*pos)++;
			break;
		case '>':
			*res = '!';
			(*pos)++;
			break;
		case '?':
			*res = 'i';
			(*pos)++;
			break;
		default:
			break;
		}
		break;
	case '>':
		switch (v[*pos + 1]) {
		case '=':
			*res = 'g';
			(*pos)++;
			break;
		case '?':
			*res = 'a';
			(*pos)++;
			break;
		default:
			break;
		}
		break;
	case '=':
		if ('=' == v[*pos + 1])
			(*pos)++;
		break;
	default:
		return(0);
	}
	(*pos)++;

	return(*res);
}

/*
 * Evaluate either a parenthesized numeric expression
 * or a single signed integer number.
 */
static int
roff_evalpar(struct roff *r, int ln,
	const char *v, int *pos, int *res, int flags)
{

	if ('(' != v[*pos])
		return(roff_getnum(v, pos, res, flags));

	(*pos)++;
	if ( ! roff_evalnum(r, ln, v, pos, res, flags | ROFFNUM_WHITE))
		return(0);

	/*
	 * Omission of the closing parenthesis
	 * is an error in validation mode,
	 * but ignored in evaluation mode.
	 */

	if (')' == v[*pos])
		(*pos)++;
	else if (NULL == res)
		return(0);

	return(1);
}

/*
 * Evaluate a complete numeric expression.
 * Proceed left to right, there is no concept of precedence.
 */
static int
roff_evalnum(struct roff *r, int ln, const char *v,
	int *pos, int *res, int flags)
{
	int		 mypos, operand2;
	char		 operator;

	if (NULL == pos) {
		mypos = 0;
		pos = &mypos;
	}

	if (flags & ROFFNUM_WHITE)
		while (isspace((unsigned char)v[*pos]))
			(*pos)++;

	if ( ! roff_evalpar(r, ln, v, pos, res, flags))
		return(0);

	while (1) {
		if (flags & ROFFNUM_WHITE)
			while (isspace((unsigned char)v[*pos]))
				(*pos)++;

		if ( ! roff_getop(v, pos, &operator))
			break;

		if (flags & ROFFNUM_WHITE)
			while (isspace((unsigned char)v[*pos]))
				(*pos)++;

		if ( ! roff_evalpar(r, ln, v, pos, &operand2, flags))
			return(0);

		if (flags & ROFFNUM_WHITE)
			while (isspace((unsigned char)v[*pos]))
				(*pos)++;

		if (NULL == res)
			continue;

		switch (operator) {
		case '+':
			*res += operand2;
			break;
		case '-':
			*res -= operand2;
			break;
		case '*':
			*res *= operand2;
			break;
		case '/':
			if (operand2 == 0) {
				mandoc_msg(MANDOCERR_DIVZERO,
					r->parse, ln, *pos, v);
				*res = 0;
				break;
			}
			*res /= operand2;
			break;
		case '%':
			if (operand2 == 0) {
				mandoc_msg(MANDOCERR_DIVZERO,
					r->parse, ln, *pos, v);
				*res = 0;
				break;
			}
			*res %= operand2;
			break;
		case '<':
			*res = *res < operand2;
			break;
		case '>':
			*res = *res > operand2;
			break;
		case 'l':
			*res = *res <= operand2;
			break;
		case 'g':
			*res = *res >= operand2;
			break;
		case '=':
			*res = *res == operand2;
			break;
		case '!':
			*res = *res != operand2;
			break;
		case '&':
			*res = *res && operand2;
			break;
		case ':':
			*res = *res || operand2;
			break;
		case 'i':
			if (operand2 < *res)
				*res = operand2;
			break;
		case 'a':
			if (operand2 > *res)
				*res = operand2;
			break;
		default:
			abort();
		}
	}
	return(1);
}

/* --- register management ------------------------------------------------ */

void
roff_setreg(struct roff *r, const char *name, int val, char sign)
{
	struct roffreg	*reg;

	/* Search for an existing register with the same name. */
	reg = r->regtab;

	while (reg && strcmp(name, reg->key.p))
		reg = reg->next;

	if (NULL == reg) {
		/* Create a new register. */
		reg = mandoc_malloc(sizeof(struct roffreg));
		reg->key.p = mandoc_strdup(name);
		reg->key.sz = strlen(name);
		reg->val = 0;
		reg->next = r->regtab;
		r->regtab = reg;
	}

	if ('+' == sign)
		reg->val += val;
	else if ('-' == sign)
		reg->val -= val;
	else
		reg->val = val;
}

/*
 * Handle some predefined read-only number registers.
 * For now, return -1 if the requested register is not predefined;
 * in case a predefined read-only register having the value -1
 * were to turn up, another special value would have to be chosen.
 */
static int
roff_getregro(const char *name)
{

	switch (*name) {
	case 'A':  /* ASCII approximation mode is always off. */
		return(0);
	case 'g':  /* Groff compatibility mode is always on. */
		return(1);
	case 'H':  /* Fixed horizontal resolution. */
		return (24);
	case 'j':  /* Always adjust left margin only. */
		return(0);
	case 'T':  /* Some output device is always defined. */
		return(1);
	case 'V':  /* Fixed vertical resolution. */
		return (40);
	default:
		return (-1);
	}
}

int
roff_getreg(const struct roff *r, const char *name)
{
	struct roffreg	*reg;
	int		 val;

	if ('.' == name[0] && '\0' != name[1] && '\0' == name[2]) {
		val = roff_getregro(name + 1);
		if (-1 != val)
			return (val);
	}

	for (reg = r->regtab; reg; reg = reg->next)
		if (0 == strcmp(name, reg->key.p))
			return(reg->val);

	return(0);
}

static int
roff_getregn(const struct roff *r, const char *name, size_t len)
{
	struct roffreg	*reg;
	int		 val;

	if ('.' == name[0] && 2 == len) {
		val = roff_getregro(name + 1);
		if (-1 != val)
			return (val);
	}

	for (reg = r->regtab; reg; reg = reg->next)
		if (len == reg->key.sz &&
		    0 == strncmp(name, reg->key.p, len))
			return(reg->val);

	return(0);
}

static void
roff_freereg(struct roffreg *reg)
{
	struct roffreg	*old_reg;

	while (NULL != reg) {
		free(reg->key.p);
		old_reg = reg;
		reg = reg->next;
		free(old_reg);
	}
}

static enum rofferr
roff_nr(ROFF_ARGS)
{
	char		*key, *val;
	size_t		 keysz;
	int		 iv;
	char		 sign;

	key = val = buf->buf + pos;
	if (*key == '\0')
		return(ROFF_IGN);

	keysz = roff_getname(r, &val, ln, pos);
	if (key[keysz] == '\\')
		return(ROFF_IGN);
	key[keysz] = '\0';

	sign = *val;
	if (sign == '+' || sign == '-')
		val++;

	if (roff_evalnum(r, ln, val, NULL, &iv, ROFFNUM_SCALE))
		roff_setreg(r, key, iv, sign);

	return(ROFF_IGN);
}

static enum rofferr
roff_rr(ROFF_ARGS)
{
	struct roffreg	*reg, **prev;
	char		*name, *cp;
	size_t		 namesz;

	name = cp = buf->buf + pos;
	if (*name == '\0')
		return(ROFF_IGN);
	namesz = roff_getname(r, &cp, ln, pos);
	name[namesz] = '\0';

	prev = &r->regtab;
	while (1) {
		reg = *prev;
		if (reg == NULL || !strcmp(name, reg->key.p))
			break;
		prev = &reg->next;
	}
	if (reg != NULL) {
		*prev = reg->next;
		free(reg->key.p);
		free(reg);
	}
	return(ROFF_IGN);
}

/* --- handler functions for roff requests -------------------------------- */

static enum rofferr
roff_rm(ROFF_ARGS)
{
	const char	 *name;
	char		 *cp;
	size_t		  namesz;

	cp = buf->buf + pos;
	while (*cp != '\0') {
		name = cp;
		namesz = roff_getname(r, &cp, ln, (int)(cp - buf->buf));
		roff_setstrn(&r->strtab, name, namesz, NULL, 0, 0);
		if (name[namesz] == '\\')
			break;
	}
	return(ROFF_IGN);
}

static enum rofferr
roff_it(ROFF_ARGS)
{
	int		 iv;

	/* Parse the number of lines. */

	if ( ! roff_evalnum(r, ln, buf->buf, &pos, &iv, 0)) {
		mandoc_msg(MANDOCERR_IT_NONUM, r->parse,
		    ln, ppos, buf->buf + 1);
		return(ROFF_IGN);
	}

	while (isspace((unsigned char)buf->buf[pos]))
		pos++;

	/*
	 * Arm the input line trap.
	 * Special-casing "an-trap" is an ugly workaround to cope
	 * with DocBook stupidly fiddling with man(7) internals.
	 */

	roffit_lines = iv;
	roffit_macro = mandoc_strdup(iv != 1 ||
	    strcmp(buf->buf + pos, "an-trap") ?
	    buf->buf + pos : "br");
	return(ROFF_IGN);
}

static enum rofferr
roff_Dd(ROFF_ARGS)
{
	const char *const	*cp;

	if ((r->options & (MPARSE_MDOC | MPARSE_QUICK)) == 0)
		for (cp = __mdoc_reserved; *cp; cp++)
			roff_setstr(r, *cp, NULL, 0);

	if (r->format == 0)
		r->format = MPARSE_MDOC;

	return(ROFF_CONT);
}

static enum rofferr
roff_TH(ROFF_ARGS)
{
	const char *const	*cp;

	if ((r->options & MPARSE_QUICK) == 0)
		for (cp = __man_reserved; *cp; cp++)
			roff_setstr(r, *cp, NULL, 0);

	if (r->format == 0)
		r->format = MPARSE_MAN;

	return(ROFF_CONT);
}

static enum rofferr
roff_TE(ROFF_ARGS)
{

	if (NULL == r->tbl)
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "TE");
	else if ( ! tbl_end(&r->tbl)) {
		free(buf->buf);
		buf->buf = mandoc_strdup(".sp");
		buf->sz = 4;
		return(ROFF_REPARSE);
	}
	return(ROFF_IGN);
}

static enum rofferr
roff_T_(ROFF_ARGS)
{

	if (NULL == r->tbl)
		mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse,
		    ln, ppos, "T&");
	else
		tbl_restart(ppos, ln, r->tbl);

	return(ROFF_IGN);
}

/*
 * Handle in-line equation delimiters.
 */
static enum rofferr
roff_eqndelim(struct roff *r, struct buf *buf, int pos)
{
	char		*cp1, *cp2;
	const char	*bef_pr, *bef_nl, *mac, *aft_nl, *aft_pr;

	/*
	 * Outside equations, look for an opening delimiter.
	 * If we are inside an equation, we already know it is
	 * in-line, or this function wouldn't have been called;
	 * so look for a closing delimiter.
	 */

	cp1 = buf->buf + pos;
	cp2 = strchr(cp1, r->eqn == NULL ?
	    r->last_eqn->odelim : r->last_eqn->cdelim);
	if (cp2 == NULL)
		return(ROFF_CONT);

	*cp2++ = '\0';
	bef_pr = bef_nl = aft_nl = aft_pr = "";

	/* Handle preceding text, protecting whitespace. */

	if (*buf->buf != '\0') {
		if (r->eqn == NULL)
			bef_pr = "\\&";
		bef_nl = "\n";
	}

	/*
	 * Prepare replacing the delimiter with an equation macro
	 * and drop leading white space from the equation.
	 */

	if (r->eqn == NULL) {
		while (*cp2 == ' ')
			cp2++;
		mac = ".EQ";
	} else
		mac = ".EN";

	/* Handle following text, protecting whitespace. */

	if (*cp2 != '\0') {
		aft_nl = "\n";
		if (r->eqn != NULL)
			aft_pr = "\\&";
	}

	/* Do the actual replacement. */

	buf->sz = mandoc_asprintf(&cp1, "%s%s%s%s%s%s%s", buf->buf,
	    bef_pr, bef_nl, mac, aft_nl, aft_pr, cp2) + 1;
	free(buf->buf);
	buf->buf = cp1;

	/* Toggle the in-line state of the eqn subsystem. */

	r->eqn_inline = r->eqn == NULL;
	return(ROFF_REPARSE);
}

static enum rofferr
roff_EQ(ROFF_ARGS)
{
	struct eqn_node *e;

	assert(r->eqn == NULL);
	e = eqn_alloc(ppos, ln, r->parse);

	if (r->last_eqn) {
		r->last_eqn->next = e;
		e->delim = r->last_eqn->delim;
		e->odelim = r->last_eqn->odelim;
		e->cdelim = r->last_eqn->cdelim;
	} else
		r->first_eqn = r->last_eqn = e;

	r->eqn = r->last_eqn = e;

	if (buf->buf[pos] != '\0')
		mandoc_vmsg(MANDOCERR_ARG_SKIP, r->parse, ln, pos,
		    ".EQ %s", buf->buf + pos);

	return(ROFF_IGN);
}

static enum rofferr
roff_EN(ROFF_ARGS)
{

	mandoc_msg(MANDOCERR_BLK_NOTOPEN, r->parse, ln, ppos, "EN");
	return(ROFF_IGN);
}

static enum rofferr
roff_TS(ROFF_ARGS)
{
	struct tbl_node	*tbl;

	if (r->tbl) {
		mandoc_msg(MANDOCERR_BLK_BROKEN, r->parse,
		    ln, ppos, "TS breaks TS");
		tbl_end(&r->tbl);
	}

	tbl = tbl_alloc(ppos, ln, r->parse);

	if (r->last_tbl)
		r->last_tbl->next = tbl;
	else
		r->first_tbl = r->last_tbl = tbl;

	r->tbl = r->last_tbl = tbl;
	return(ROFF_IGN);
}

static enum rofferr
roff_brp(ROFF_ARGS)
{

	buf->buf[pos - 1] = '\0';
	return(ROFF_CONT);
}

static enum rofferr
roff_cc(ROFF_ARGS)
{
	const char	*p;

	p = buf->buf + pos;

	if (*p == '\0' || (r->control = *p++) == '.')
		r->control = 0;

	if (*p != '\0')
		mandoc_vmsg(MANDOCERR_ARG_EXCESS, r->parse,
		    ln, p - buf->buf, "cc ... %s", p);

	return(ROFF_IGN);
}

static enum rofferr
roff_tr(ROFF_ARGS)
{
	const char	*p, *first, *second;
	size_t		 fsz, ssz;
	enum mandoc_esc	 esc;

	p = buf->buf + pos;

	if (*p == '\0') {
		mandoc_msg(MANDOCERR_REQ_EMPTY, r->parse, ln, ppos, "tr");
		return(ROFF_IGN);
	}

	while (*p != '\0') {
		fsz = ssz = 1;

		first = p++;
		if (*first == '\\') {
			esc = mandoc_escape(&p, NULL, NULL);
			if (esc == ESCAPE_ERROR) {
				mandoc_msg(MANDOCERR_ESC_BAD, r->parse,
				    ln, (int)(p - buf->buf), first);
				return(ROFF_IGN);
			}
			fsz = (size_t)(p - first);
		}

		second = p++;
		if (*second == '\\') {
			esc = mandoc_escape(&p, NULL, NULL);
			if (esc == ESCAPE_ERROR) {
				mandoc_msg(MANDOCERR_ESC_BAD, r->parse,
				    ln, (int)(p - buf->buf), second);
				return(ROFF_IGN);
			}
			ssz = (size_t)(p - second);
		} else if (*second == '\0') {
			mandoc_vmsg(MANDOCERR_TR_ODD, r->parse,
			    ln, first - buf->buf, "tr %s", first);
			second = " ";
			p--;
		}

		if (fsz > 1) {
			roff_setstrn(&r->xmbtab, first, fsz,
			    second, ssz, 0);
			continue;
		}

		if (r->xtab == NULL)
			r->xtab = mandoc_calloc(128,
			    sizeof(struct roffstr));

		free(r->xtab[(int)*first].p);
		r->xtab[(int)*first].p = mandoc_strndup(second, ssz);
		r->xtab[(int)*first].sz = ssz;
	}

	return(ROFF_IGN);
}

static enum rofferr
roff_so(ROFF_ARGS)
{
	char *name, *cp;

	name = buf->buf + pos;
	mandoc_vmsg(MANDOCERR_SO, r->parse, ln, ppos, "so %s", name);

	/*
	 * 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.
	 */

	if (*name == '/' || strstr(name, "../") || strstr(name, "/..")) {
		mandoc_vmsg(MANDOCERR_SO_PATH, r->parse, ln, ppos,
		    ".so %s", name);
		buf->sz = mandoc_asprintf(&cp,
		    ".sp\nSee the file %s.\n.sp", name) + 1;
		free(buf->buf);
		buf->buf = cp;
		*offs = 0;
		return(ROFF_REPARSE);
	}

	*offs = pos;
	return(ROFF_SO);
}

/* --- user defined strings and macros ------------------------------------ */

static enum rofferr
roff_userdef(ROFF_ARGS)
{
	const char	 *arg[9], *ap;
	char		 *cp, *n1, *n2;
	int		  i;
	size_t		  asz, rsz;

	/*
	 * Collect pointers to macro argument strings
	 * and NUL-terminate them.
	 */

	cp = buf->buf + pos;
	for (i = 0; i < 9; i++)
		arg[i] = *cp == '\0' ? "" :
		    mandoc_getarg(r->parse, &cp, ln, &pos);

	/*
	 * Expand macro arguments.
	 */

	buf->sz = strlen(r->current_string) + 1;
	n1 = cp = mandoc_malloc(buf->sz);
	memcpy(n1, r->current_string, buf->sz);
	while (*cp != '\0') {

		/* Scan ahead for the next argument invocation. */

		if (*cp++ != '\\')
			continue;
		if (*cp++ != '$')
			continue;
		i = *cp - '1';
		if (0 > i || 8 < i)
			continue;
		cp -= 2;

		/*
		 * Determine the size of the expanded argument,
		 * taking escaping of quotes into account.
		 */

		asz = 0;
		for (ap = arg[i]; *ap != '\0'; ap++) {
			asz++;
			if (*ap == '"')
				asz += 3;
		}
		if (asz != 3) {

			/*
			 * Determine the size of the rest of the
			 * unexpanded macro, including the NUL.
			 */

			rsz = buf->sz - (cp - n1) - 3;

			/*
			 * When shrinking, move before
			 * releasing the storage.
			 */

			if (asz < 3)
				memmove(cp + asz, cp + 3, rsz);

			/*
			 * Resize the storage for the macro
			 * and readjust the parse pointer.
			 */

			buf->sz += asz - 3;
			n2 = mandoc_realloc(n1, buf->sz);
			cp = n2 + (cp - n1);
			n1 = n2;

			/*
			 * When growing, make room
			 * for the expanded argument.
			 */

			if (asz > 3)
				memmove(cp + asz, cp + 3, rsz);
		}

		/* Copy the expanded argument, escaping quotes. */

		n2 = cp;
		for (ap = arg[i]; *ap != '\0'; ap++) {
			if (*ap == '"') {
				memcpy(n2, "\\(dq", 4);
				n2 += 4;
			} else
				*n2++ = *ap;
		}
	}

	/*
	 * Replace the macro invocation
	 * by the expanded macro.
	 */

	free(buf->buf);
	buf->buf = n1;
	*offs = 0;

	return(buf->sz > 1 && buf->buf[buf->sz - 2] == '\n' ?
	   ROFF_REPARSE : ROFF_APPEND);
}

static size_t
roff_getname(struct roff *r, char **cpp, int ln, int pos)
{
	char	 *name, *cp;
	size_t	  namesz;

	name = *cpp;
	if ('\0' == *name)
		return(0);

	/* Read until end of name and terminate it with NUL. */
	for (cp = name; 1; cp++) {
		if ('\0' == *cp || ' ' == *cp) {
			namesz = cp - name;
			break;
		}
		if ('\\' != *cp)
			continue;
		namesz = cp - name;
		if ('{' == cp[1] || '}' == cp[1])
			break;
		cp++;
		if ('\\' == *cp)
			continue;
		mandoc_vmsg(MANDOCERR_NAMESC, r->parse, ln, pos,
		    "%.*s", (int)(cp - name + 1), name);
		mandoc_escape((const char **)&cp, NULL, NULL);
		break;
	}

	/* Read past spaces. */
	while (' ' == *cp)
		cp++;

	*cpp = cp;
	return(namesz);
}

/*
 * Store *string into the user-defined string called *name.
 * To clear an existing entry, call with (*r, *name, NULL, 0).
 * append == 0: replace mode
 * append == 1: single-line append mode
 * append == 2: multiline append mode, append '\n' after each call
 */
static void
roff_setstr(struct roff *r, const char *name, const char *string,
	int append)
{

	roff_setstrn(&r->strtab, name, strlen(name), string,
	    string ? strlen(string) : 0, append);
}

static void
roff_setstrn(struct roffkv **r, const char *name, size_t namesz,
		const char *string, size_t stringsz, int append)
{
	struct roffkv	*n;
	char		*c;
	int		 i;
	size_t		 oldch, newch;

	/* Search for an existing string with the same name. */
	n = *r;

	while (n && (namesz != n->key.sz ||
			strncmp(n->key.p, name, namesz)))
		n = n->next;

	if (NULL == n) {
		/* Create a new string table entry. */
		n = mandoc_malloc(sizeof(struct roffkv));
		n->key.p = mandoc_strndup(name, namesz);
		n->key.sz = namesz;
		n->val.p = NULL;
		n->val.sz = 0;
		n->next = *r;
		*r = n;
	} else if (0 == append) {
		free(n->val.p);
		n->val.p = NULL;
		n->val.sz = 0;
	}

	if (NULL == string)
		return;

	/*
	 * One additional byte for the '\n' in multiline mode,
	 * and one for the terminating '\0'.
	 */
	newch = stringsz + (1 < append ? 2u : 1u);

	if (NULL == n->val.p) {
		n->val.p = mandoc_malloc(newch);
		*n->val.p = '\0';
		oldch = 0;
	} else {
		oldch = n->val.sz;
		n->val.p = mandoc_realloc(n->val.p, oldch + newch);
	}

	/* Skip existing content in the destination buffer. */
	c = n->val.p + (int)oldch;

	/* Append new content to the destination buffer. */
	i = 0;
	while (i < (int)stringsz) {
		/*
		 * Rudimentary roff copy mode:
		 * Handle escaped backslashes.
		 */
		if ('\\' == string[i] && '\\' == string[i + 1])
			i++;
		*c++ = string[i++];
	}

	/* Append terminating bytes. */
	if (1 < append)
		*c++ = '\n';

	*c = '\0';
	n->val.sz = (int)(c - n->val.p);
}

static const char *
roff_getstrn(const struct roff *r, const char *name, size_t len)
{
	const struct roffkv *n;
	int i;

	for (n = r->strtab; n; n = n->next)
		if (0 == strncmp(name, n->key.p, len) &&
		    '\0' == n->key.p[(int)len])
			return(n->val.p);

	for (i = 0; i < PREDEFS_MAX; i++)
		if (0 == strncmp(name, predefs[i].name, len) &&
				'\0' == predefs[i].name[(int)len])
			return(predefs[i].str);

	return(NULL);
}

static void
roff_freestr(struct roffkv *r)
{
	struct roffkv	 *n, *nn;

	for (n = r; n; n = nn) {
		free(n->key.p);
		free(n->val.p);
		nn = n->next;
		free(n);
	}
}

/* --- accessors and utility functions ------------------------------------ */

const struct tbl_span *
roff_span(const struct roff *r)
{

	return(r->tbl ? tbl_span(r->tbl) : NULL);
}

const struct eqn *
roff_eqn(const struct roff *r)
{

	return(r->last_eqn ? &r->last_eqn->eqn : NULL);
}

/*
 * Duplicate an input string, making the appropriate character
 * conversations (as stipulated by `tr') along the way.
 * Returns a heap-allocated string with all the replacements made.
 */
char *
roff_strdup(const struct roff *r, const char *p)
{
	const struct roffkv *cp;
	char		*res;
	const char	*pp;
	size_t		 ssz, sz;
	enum mandoc_esc	 esc;

	if (NULL == r->xmbtab && NULL == r->xtab)
		return(mandoc_strdup(p));
	else if ('\0' == *p)
		return(mandoc_strdup(""));

	/*
	 * Step through each character looking for term matches
	 * (remember that a `tr' can be invoked with an escape, which is
	 * a glyph but the escape is multi-character).
	 * We only do this if the character hash has been initialised
	 * and the string is >0 length.
	 */

	res = NULL;
	ssz = 0;

	while ('\0' != *p) {
		if ('\\' != *p && r->xtab && r->xtab[(int)*p].p) {
			sz = r->xtab[(int)*p].sz;
			res = mandoc_realloc(res, ssz + sz + 1);
			memcpy(res + ssz, r->xtab[(int)*p].p, sz);
			ssz += sz;
			p++;
			continue;
		} else if ('\\' != *p) {
			res = mandoc_realloc(res, ssz + 2);
			res[ssz++] = *p++;
			continue;
		}

		/* Search for term matches. */
		for (cp = r->xmbtab; cp; cp = cp->next)
			if (0 == strncmp(p, cp->key.p, cp->key.sz))
				break;

		if (NULL != cp) {
			/*
			 * A match has been found.
			 * Append the match to the array and move
			 * forward by its keysize.
			 */
			res = mandoc_realloc(res,
			    ssz + cp->val.sz + 1);
			memcpy(res + ssz, cp->val.p, cp->val.sz);
			ssz += cp->val.sz;
			p += (int)cp->key.sz;
			continue;
		}

		/*
		 * Handle escapes carefully: we need to copy
		 * over just the escape itself, or else we might
		 * do replacements within the escape itself.
		 * Make sure to pass along the bogus string.
		 */
		pp = p++;
		esc = mandoc_escape(&p, NULL, NULL);
		if (ESCAPE_ERROR == esc) {
			sz = strlen(pp);
			res = mandoc_realloc(res, ssz + sz + 1);
			memcpy(res + ssz, pp, sz);
			break;
		}
		/*
		 * We bail out on bad escapes.
		 * No need to warn: we already did so when
		 * roff_res() was called.
		 */
		sz = (int)(p - pp);
		res = mandoc_realloc(res, ssz + sz + 1);
		memcpy(res + ssz, pp, sz);
		ssz += sz;
	}

	res[(int)ssz] = '\0';
	return(res);
}

int
roff_getformat(const struct roff *r)
{

	return(r->format);
}

/*
 * Find out whether a line is a macro line or not.
 * If it is, adjust the current position and return one; if it isn't,
 * return zero and don't change the current position.
 * If the control character has been set with `.cc', then let that grain
 * precedence.
 * This is slighly contrary to groff, where using the non-breaking
 * control character when `cc' has been invoked will cause the
 * non-breaking macro contents to be printed verbatim.
 */
int
roff_getcontrol(const struct roff *r, const char *cp, int *ppos)
{
	int		pos;

	pos = *ppos;

	if (0 != r->control && cp[pos] == r->control)
		pos++;
	else if (0 != r->control)
		return(0);
	else if ('\\' == cp[pos] && '.' == cp[pos + 1])
		pos += 2;
	else if ('.' == cp[pos] || '\'' == cp[pos])
		pos++;
	else
		return(0);

	while (' ' == cp[pos] || '\t' == cp[pos])
		pos++;

	*ppos = pos;
	return(1);
}