/*      $Id: mdoc_macro.c,v 1.234 2020/01/19 18:02:00 schwarze Exp $ */
/*
 * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2010, 2012-2020 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#include "mandoc.h"
#include "roff.h"
#include "mdoc.h"
#include "libmandoc.h"
#include "roff_int.h"
#include "libmdoc.h"

static  void            blk_full(MACRO_PROT_ARGS);
static  void            blk_exp_close(MACRO_PROT_ARGS);
static  void            blk_part_exp(MACRO_PROT_ARGS);
static  void            blk_part_imp(MACRO_PROT_ARGS);
static  void            ctx_synopsis(MACRO_PROT_ARGS);
static  void            in_line_eoln(MACRO_PROT_ARGS);
static  void            in_line_argn(MACRO_PROT_ARGS);
static  void            in_line(MACRO_PROT_ARGS);
static  void            phrase_ta(MACRO_PROT_ARGS);

static  void            append_delims(struct roff_man *, int, int *, char *);
static  void            dword(struct roff_man *, int, int, const char *,
                                enum mdelim, int);
static  int             find_pending(struct roff_man *, enum roff_tok,
                                int, int, struct roff_node *);
static  int             lookup(struct roff_man *, int, int, int, const char *);
static  int             macro_or_word(MACRO_PROT_ARGS, char *, int);
static  void            break_intermediate(struct roff_node *,
                                struct roff_node *);
static  int             parse_rest(struct roff_man *, enum roff_tok,
                                int, int *, char *);
static  enum roff_tok   rew_alt(enum roff_tok);
static  void            rew_elem(struct roff_man *, enum roff_tok);
static  void            rew_last(struct roff_man *, const struct roff_node *);
static  void            rew_pending(struct roff_man *,
                                const struct roff_node *);

static const struct mdoc_macro mdoc_macros[MDOC_MAX - MDOC_Dd] = {
        { in_line_eoln, MDOC_PROLOGUE | MDOC_JOIN }, /* Dd */
        { in_line_eoln, MDOC_PROLOGUE }, /* Dt */
        { in_line_eoln, MDOC_PROLOGUE }, /* Os */
        { blk_full, MDOC_PARSED | MDOC_JOIN }, /* Sh */
        { blk_full, MDOC_PARSED | MDOC_JOIN }, /* Ss */
        { in_line_eoln, 0 }, /* Pp */
        { blk_part_imp, MDOC_PARSED | MDOC_JOIN }, /* D1 */
        { blk_part_imp, MDOC_PARSED | MDOC_JOIN }, /* Dl */
        { blk_full, MDOC_EXPLICIT }, /* Bd */
        { blk_exp_close, MDOC_EXPLICIT | MDOC_JOIN }, /* Ed */
        { blk_full, MDOC_EXPLICIT }, /* Bl */
        { blk_exp_close, MDOC_EXPLICIT | MDOC_JOIN }, /* El */
        { blk_full, MDOC_PARSED | MDOC_JOIN }, /* It */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Ad */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* An */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_IGNDELIM | MDOC_JOIN }, /* Ap */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Ar */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Cd */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Cm */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Dv */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Er */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Ev */
        { in_line_eoln, 0 }, /* Ex */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Fa */
        { in_line_eoln, 0 }, /* Fd */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Fl */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Fn */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Ft */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Ic */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* In */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Li */
        { blk_full, MDOC_JOIN }, /* Nd */
        { ctx_synopsis, MDOC_CALLABLE | MDOC_PARSED }, /* Nm */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED }, /* Op */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Ot */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Pa */
        { in_line_eoln, 0 }, /* Rv */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* St */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Va */
        { ctx_synopsis, MDOC_CALLABLE | MDOC_PARSED }, /* Vt */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Xr */
        { in_line_eoln, MDOC_JOIN }, /* %A */
        { in_line_eoln, MDOC_JOIN }, /* %B */
        { in_line_eoln, MDOC_JOIN }, /* %D */
        { in_line_eoln, MDOC_JOIN }, /* %I */
        { in_line_eoln, MDOC_JOIN }, /* %J */
        { in_line_eoln, 0 }, /* %N */
        { in_line_eoln, MDOC_JOIN }, /* %O */
        { in_line_eoln, 0 }, /* %P */
        { in_line_eoln, MDOC_JOIN }, /* %R */
        { in_line_eoln, MDOC_JOIN }, /* %T */
        { in_line_eoln, 0 }, /* %V */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Ac */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Ao */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Aq */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* At */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Bc */
        { blk_full, MDOC_EXPLICIT }, /* Bf */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Bo */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Bq */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Bsx */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Bx */
        { in_line_eoln, 0 }, /* Db */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Dc */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Do */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Dq */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED | MDOC_EXPLICIT }, /* Ec */
        { blk_exp_close, MDOC_EXPLICIT | MDOC_JOIN }, /* Ef */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Em */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED | MDOC_EXPLICIT }, /* Eo */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Fx */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Ms */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* No */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_IGNDELIM | MDOC_JOIN }, /* Ns */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Nx */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Ox */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Pc */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED | MDOC_IGNDELIM }, /* Pf */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Po */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Pq */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Qc */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Ql */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Qo */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Qq */
        { blk_exp_close, MDOC_EXPLICIT | MDOC_JOIN }, /* Re */
        { blk_full, MDOC_EXPLICIT }, /* Rs */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Sc */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* So */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Sq */
        { in_line_argn, 0 }, /* Sm */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Sx */
        { in_line, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Sy */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Tn */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Ux */
        { blk_exp_close, MDOC_EXPLICIT | MDOC_CALLABLE | MDOC_PARSED }, /* Xc */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED | MDOC_EXPLICIT }, /* Xo */
        { blk_full, MDOC_EXPLICIT | MDOC_CALLABLE }, /* Fo */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Fc */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Oo */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Oc */
        { blk_full, MDOC_EXPLICIT }, /* Bk */
        { blk_exp_close, MDOC_EXPLICIT | MDOC_JOIN }, /* Ek */
        { in_line_eoln, 0 }, /* Bt */
        { in_line_eoln, 0 }, /* Hf */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Fr */
        { in_line_eoln, 0 }, /* Ud */
        { in_line, 0 }, /* Lb */
        { in_line_eoln, 0 }, /* Lp */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Lk */
        { in_line, MDOC_CALLABLE | MDOC_PARSED }, /* Mt */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Brq */
        { blk_part_exp, MDOC_CALLABLE | MDOC_PARSED |
                        MDOC_EXPLICIT | MDOC_JOIN }, /* Bro */
        { blk_exp_close, MDOC_CALLABLE | MDOC_PARSED |
                         MDOC_EXPLICIT | MDOC_JOIN }, /* Brc */
        { in_line_eoln, MDOC_JOIN }, /* %C */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Es */
        { blk_part_imp, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* En */
        { in_line_argn, MDOC_CALLABLE | MDOC_PARSED }, /* Dx */
        { in_line_eoln, MDOC_JOIN }, /* %Q */
        { in_line_eoln, 0 }, /* %U */
        { phrase_ta, MDOC_CALLABLE | MDOC_PARSED | MDOC_JOIN }, /* Ta */
        { in_line_eoln, 0 }, /* Tg */
};


const struct mdoc_macro *
mdoc_macro(enum roff_tok tok)
{
        assert(tok >= MDOC_Dd && tok < MDOC_MAX);
        return mdoc_macros + (tok - MDOC_Dd);
}

/*
 * This is called at the end of parsing.  It must traverse up the tree,
 * closing out open [implicit] scopes.  Obviously, open explicit scopes
 * are errors.
 */
void
mdoc_endparse(struct roff_man *mdoc)
{
        struct roff_node *n;

        /* Scan for open explicit scopes. */

        n = mdoc->last->flags & NODE_VALID ?
            mdoc->last->parent : mdoc->last;

        for ( ; n; n = n->parent)
                if (n->type == ROFFT_BLOCK &&
                    mdoc_macro(n->tok)->flags & MDOC_EXPLICIT)
                        mandoc_msg(MANDOCERR_BLK_NOEND,
                            n->line, n->pos, "%s", roff_name[n->tok]);

        /* Rewind to the first. */

        rew_last(mdoc, mdoc->meta.first);
}

/*
 * Look up the macro at *p called by "from",
 * or as a line macro if from == TOKEN_NONE.
 */
static int
lookup(struct roff_man *mdoc, int from, int line, int ppos, const char *p)
{
        enum roff_tok    res;

        if (mdoc->flags & MDOC_PHRASEQF) {
                mdoc->flags &= ~MDOC_PHRASEQF;
                return TOKEN_NONE;
        }
        if (from == TOKEN_NONE || mdoc_macro(from)->flags & MDOC_PARSED) {
                res = roffhash_find(mdoc->mdocmac, p, 0);
                if (res != TOKEN_NONE) {
                        if (mdoc_macro(res)->flags & MDOC_CALLABLE)
                                return res;
                        mandoc_msg(MANDOCERR_MACRO_CALL, line, ppos, "%s", p);
                }
        }
        return TOKEN_NONE;
}

/*
 * Rewind up to and including a specific node.
 */
static void
rew_last(struct roff_man *mdoc, const struct roff_node *to)
{

        if (to->flags & NODE_VALID)
                return;

        while (mdoc->last != to) {
                mdoc_state(mdoc, mdoc->last);
                mdoc->last->flags |= NODE_VALID | NODE_ENDED;
                mdoc->last = mdoc->last->parent;
        }
        mdoc_state(mdoc, mdoc->last);
        mdoc->last->flags |= NODE_VALID | NODE_ENDED;
        mdoc->next = ROFF_NEXT_SIBLING;
}

/*
 * Rewind up to a specific block, including all blocks that broke it.
 */
static void
rew_pending(struct roff_man *mdoc, const struct roff_node *n)
{

        for (;;) {
                rew_last(mdoc, n);

                if (mdoc->last == n) {
                        switch (n->type) {
                        case ROFFT_HEAD:
                                roff_body_alloc(mdoc, n->line, n->pos,
                                    n->tok);
                                if (n->tok == MDOC_Ss)
                                        mdoc->flags &= ~ROFF_NONOFILL;
                                break;
                        case ROFFT_BLOCK:
                                break;
                        default:
                                return;
                        }
                        if ( ! (n->flags & NODE_BROKEN))
                                return;
                } else
                        n = mdoc->last;

                for (;;) {
                        if ((n = n->parent) == NULL)
                                return;

                        if (n->type == ROFFT_BLOCK ||
                            n->type == ROFFT_HEAD) {
                                if (n->flags & NODE_ENDED)
                                        break;
                                else
                                        return;
                        }
                }
        }
}

/*
 * For a block closing macro, return the corresponding opening one.
 * Otherwise, return the macro itself.
 */
static enum roff_tok
rew_alt(enum roff_tok tok)
{
        switch (tok) {
        case MDOC_Ac:
                return MDOC_Ao;
        case MDOC_Bc:
                return MDOC_Bo;
        case MDOC_Brc:
                return MDOC_Bro;
        case MDOC_Dc:
                return MDOC_Do;
        case MDOC_Ec:
                return MDOC_Eo;
        case MDOC_Ed:
                return MDOC_Bd;
        case MDOC_Ef:
                return MDOC_Bf;
        case MDOC_Ek:
                return MDOC_Bk;
        case MDOC_El:
                return MDOC_Bl;
        case MDOC_Fc:
                return MDOC_Fo;
        case MDOC_Oc:
                return MDOC_Oo;
        case MDOC_Pc:
                return MDOC_Po;
        case MDOC_Qc:
                return MDOC_Qo;
        case MDOC_Re:
                return MDOC_Rs;
        case MDOC_Sc:
                return MDOC_So;
        case MDOC_Xc:
                return MDOC_Xo;
        default:
                return tok;
        }
}

static void
rew_elem(struct roff_man *mdoc, enum roff_tok tok)
{
        struct roff_node *n;

        n = mdoc->last;
        if (n->type != ROFFT_ELEM)
                n = n->parent;
        assert(n->type == ROFFT_ELEM);
        assert(tok == n->tok);
        rew_last(mdoc, n);
}

static void
break_intermediate(struct roff_node *n, struct roff_node *breaker)
{
        if (n != breaker &&
            n->type != ROFFT_BLOCK && n->type != ROFFT_HEAD &&
            (n->type != ROFFT_BODY || n->end != ENDBODY_NOT))
                n = n->parent;
        while (n != breaker) {
                if ( ! (n->flags & NODE_VALID))
                        n->flags |= NODE_BROKEN;
                n = n->parent;
        }
}

/*
 * If there is an open sub-block of the target requiring
 * explicit close-out, postpone closing out the target until
 * the rew_pending() call closing out the sub-block.
 */
static int
find_pending(struct roff_man *mdoc, enum roff_tok tok, int line, int ppos,
        struct roff_node *target)
{
        struct roff_node        *n;
        int                      irc;

        if (target->flags & NODE_VALID)
                return 0;

        irc = 0;
        for (n = mdoc->last; n != NULL && n != target; n = n->parent) {
                if (n->flags & NODE_ENDED)
                        continue;
                if (n->type == ROFFT_BLOCK &&
                    mdoc_macro(n->tok)->flags & MDOC_EXPLICIT) {
                        irc = 1;
                        break_intermediate(mdoc->last, target);
                        if (target->type == ROFFT_HEAD)
                                target->flags |= NODE_ENDED;
                        else if ( ! (target->flags & NODE_ENDED)) {
                                mandoc_msg(MANDOCERR_BLK_NEST,
                                    line, ppos, "%s breaks %s",
                                    roff_name[tok], roff_name[n->tok]);
                                mdoc_endbody_alloc(mdoc, line, ppos,
                                    tok, target);
                        }
                }
        }
        return irc;
}

/*
 * Allocate a word and check whether it's punctuation or not.
 * Punctuation consists of those tokens found in mdoc_isdelim().
 */
static void
dword(struct roff_man *mdoc, int line, int col, const char *p,
                enum mdelim d, int may_append)
{

        if (d == DELIM_MAX)
                d = mdoc_isdelim(p);

        if (may_append &&
            ! (mdoc->flags & (MDOC_SYNOPSIS | MDOC_KEEP | MDOC_SMOFF)) &&
            d == DELIM_NONE && mdoc->last->type == ROFFT_TEXT &&
            mdoc_isdelim(mdoc->last->string) == DELIM_NONE) {
                roff_word_append(mdoc, p);
                return;
        }

        roff_word_alloc(mdoc, line, col, p);

        /*
         * If the word consists of a bare delimiter,
         * flag the new node accordingly,
         * unless doing so was vetoed by the invoking macro.
         * Always clear the veto, it is only valid for one word.
         */

        if (d == DELIM_OPEN)
                mdoc->last->flags |= NODE_DELIMO;
        else if (d == DELIM_CLOSE &&
            ! (mdoc->flags & MDOC_NODELIMC) &&
            mdoc->last->parent->tok != MDOC_Fd)
                mdoc->last->flags |= NODE_DELIMC;
        mdoc->flags &= ~MDOC_NODELIMC;
}

static void
append_delims(struct roff_man *mdoc, int line, int *pos, char *buf)
{
        char            *p;
        int              la;
        enum margserr    ac;

        if (buf[*pos] == '\0')
                return;

        for (;;) {
                la = *pos;
                ac = mdoc_args(mdoc, line, pos, buf, TOKEN_NONE, &p);
                if (ac == ARGS_EOLN)
                        break;
                dword(mdoc, line, la, p, DELIM_MAX, 1);

                /*
                 * If we encounter end-of-sentence symbols, then trigger
                 * the double-space.
                 *
                 * XXX: it's easy to allow this to propagate outward to
                 * the last symbol, such that `. )' will cause the
                 * correct double-spacing.  However, (1) groff isn't
                 * smart enough to do this and (2) it would require
                 * knowing which symbols break this behaviour, for
                 * example, `.  ;' shouldn't propagate the double-space.
                 */

                if (mandoc_eos(p, strlen(p)))
                        mdoc->last->flags |= NODE_EOS;
                if (ac == ARGS_ALLOC)
                        free(p);
        }
}

/*
 * Parse one word.
 * If it is a macro, call it and return 1.
 * Otherwise, allocate it and return 0.
 */
static int
macro_or_word(MACRO_PROT_ARGS, char *p, int parsed)
{
        int              ntok;

        ntok = buf[ppos] == '"' || parsed == 0 ||
            mdoc->flags & MDOC_PHRASELIT ? TOKEN_NONE :
            lookup(mdoc, tok, line, ppos, p);

        if (ntok == TOKEN_NONE) {
                dword(mdoc, line, ppos, p, DELIM_MAX, tok == TOKEN_NONE ||
                    mdoc_macro(tok)->flags & MDOC_JOIN);
                return 0;
        } else {
                if (tok != TOKEN_NONE &&
                    mdoc_macro(tok)->fp == in_line_eoln)
                        rew_elem(mdoc, tok);
                (*mdoc_macro(ntok)->fp)(mdoc, ntok, line, ppos, pos, buf);
                if (tok == TOKEN_NONE)
                        append_delims(mdoc, line, pos, buf);
                return 1;
        }
}

/*
 * Close out block partial/full explicit.
 */
static void
blk_exp_close(MACRO_PROT_ARGS)
{
        struct roff_node *body;         /* Our own body. */
        struct roff_node *endbody;      /* Our own end marker. */
        struct roff_node *itblk;        /* An It block starting later. */
        struct roff_node *later;        /* A sub-block starting later. */
        struct roff_node *n;            /* Search back to our block. */
        struct roff_node *target;       /* For find_pending(). */

        int              j, lastarg, maxargs, nl, pending;
        enum margserr    ac;
        enum roff_tok    atok, ntok;
        char            *p;

        nl = MDOC_NEWLINE & mdoc->flags;

        switch (tok) {
        case MDOC_Ec:
                maxargs = 1;
                break;
        case MDOC_Ek:
                mdoc->flags &= ~MDOC_KEEP;
                /* FALLTHROUGH */
        default:
                maxargs = 0;
                break;
        }

        /* Search backwards for the beginning of our own body. */

        atok = rew_alt(tok);
        body = NULL;
        for (n = mdoc->last; n; n = n->parent) {
                if (n->flags & NODE_ENDED || n->tok != atok ||
                    n->type != ROFFT_BODY || n->end != ENDBODY_NOT)
                        continue;
                body = n;
                break;
        }

        /*
         * Search backwards for beginnings of blocks,
         * both of our own and of pending sub-blocks.
         */

        endbody = itblk = later = NULL;
        for (n = mdoc->last; n; n = n->parent) {
                if (n->flags & NODE_ENDED)
                        continue;

                /*
                 * Mismatching end macros can never break anything
                 * and we only care about the breaking of BLOCKs.
                 */

                if (body == NULL || n->type != ROFFT_BLOCK)
                        continue;

                /*
                 * SYNOPSIS name blocks can not be broken themselves,
                 * but they do get broken together with a broken child.
                 */

                if (n->tok == MDOC_Nm) {
                        if (later != NULL)
                                n->flags |= NODE_BROKEN | NODE_ENDED;
                        continue;
                }

                if (n->tok == MDOC_It) {
                        itblk = n;
                        continue;
                }

                if (atok == n->tok) {

                        /*
                         * Found the start of our own block.
                         * When there is no pending sub block,
                         * just proceed to closing out.
                         */

                        if (later == NULL ||
                            (tok == MDOC_El && itblk == NULL))
                                break;

                        /*
                         * When there is a pending sub block, postpone
                         * closing out the current block until the
                         * rew_pending() closing out the sub-block.
                         * Mark the place where the formatting - but not
                         * the scope - of the current block ends.
                         */

                        mandoc_msg(MANDOCERR_BLK_NEST,
                            line, ppos, "%s breaks %s",
                            roff_name[atok], roff_name[later->tok]);

                        endbody = mdoc_endbody_alloc(mdoc, line, ppos,
                            atok, body);

                        if (tok == MDOC_El)
                                itblk->flags |= NODE_ENDED | NODE_BROKEN;

                        /*
                         * If a block closing macro taking arguments
                         * breaks another block, put the arguments
                         * into the end marker.
                         */

                        if (maxargs)
                                mdoc->next = ROFF_NEXT_CHILD;
                        break;
                }

                /*
                 * Explicit blocks close out description lines, but
                 * even those can get broken together with a child.
                 */

                if (n->tok == MDOC_Nd) {
                        if (later != NULL)
                                n->flags |= NODE_BROKEN | NODE_ENDED;
                        else
                                rew_last(mdoc, n);
                        continue;
                }

                /* Breaking an open sub block. */

                break_intermediate(mdoc->last, body);
                n->flags |= NODE_BROKEN;
                if (later == NULL)
                        later = n;
        }

        if (body == NULL) {
                mandoc_msg(MANDOCERR_BLK_NOTOPEN, line, ppos,
                    "%s", roff_name[tok]);
                if (maxargs && endbody == NULL) {
                        /*
                         * Stray .Ec without previous .Eo:
                         * Break the output line, keep the arguments.
                         */
                        roff_elem_alloc(mdoc, line, ppos, ROFF_br);
                        rew_elem(mdoc, ROFF_br);
                }
        } else if (endbody == NULL) {
                rew_last(mdoc, body);
                if (maxargs)
                        mdoc_tail_alloc(mdoc, line, ppos, atok);
        }

        if ((mdoc_macro(tok)->flags & MDOC_PARSED) == 0) {
                if (buf[*pos] != '\0')
                        mandoc_msg(MANDOCERR_ARG_SKIP, line, ppos,
                            "%s %s", roff_name[tok], buf + *pos);
                if (endbody == NULL && n != NULL)
                        rew_pending(mdoc, n);

                /*
                 * Restore the fill mode that was set before the display.
                 * This needs to be done here rather than during validation
                 * such that subsequent nodes get the right flags.
                 */

                if (tok == MDOC_Ed && body != NULL) {
                        if (body->flags & NODE_NOFILL)
                                mdoc->flags |= ROFF_NOFILL;
                        else
                                mdoc->flags &= ~ROFF_NOFILL;
                }
                return;
        }

        if (endbody != NULL)
                n = endbody;

        ntok = TOKEN_NONE;
        for (j = 0; ; j++) {
                lastarg = *pos;

                if (j == maxargs && n != NULL)
                        rew_last(mdoc, n);

                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);
                if (ac == ARGS_PUNCT || ac == ARGS_EOLN)
                        break;

                ntok = lookup(mdoc, tok, line, lastarg, p);

                if (ntok == TOKEN_NONE) {
                        dword(mdoc, line, lastarg, p, DELIM_MAX,
                            mdoc_macro(tok)->flags & MDOC_JOIN);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        continue;
                }
                if (ac == ARGS_ALLOC)
                        free(p);

                if (n != NULL)
                        rew_last(mdoc, n);
                mdoc->flags &= ~MDOC_NEWLINE;
                (*mdoc_macro(ntok)->fp)(mdoc, ntok, line, lastarg, pos, buf);
                break;
        }

        if (n != NULL) {
                pending = 0;
                if (ntok != TOKEN_NONE && n->flags & NODE_BROKEN) {
                        target = n;
                        do
                                target = target->parent;
                        while ( ! (target->flags & NODE_ENDED));
                        pending = find_pending(mdoc, ntok, line, ppos, target);
                }
                if ( ! pending)
                        rew_pending(mdoc, n);
        }
        if (nl)
                append_delims(mdoc, line, pos, buf);
}

static void
in_line(MACRO_PROT_ARGS)
{
        int              la, scope, cnt, firstarg, mayopen, nc, nl;
        enum roff_tok    ntok;
        enum margserr    ac;
        enum mdelim      d;
        struct mdoc_arg *arg;
        char            *p;

        nl = MDOC_NEWLINE & mdoc->flags;

        /*
         * Whether we allow ignored elements (those without content,
         * usually because of reserved words) to squeak by.
         */

        switch (tok) {
        case MDOC_An:
        case MDOC_Ar:
        case MDOC_Fl:
        case MDOC_Mt:
        case MDOC_Nm:
        case MDOC_Pa:
                nc = 1;
                break;
        default:
                nc = 0;
                break;
        }

        mdoc_argv(mdoc, line, tok, &arg, pos, buf);

        d = DELIM_NONE;
        firstarg = 1;
        mayopen = 1;
        for (cnt = scope = 0;; ) {
                la = *pos;
                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);

                /*
                 * At the end of a macro line,
                 * opening delimiters do not suppress spacing.
                 */

                if (ac == ARGS_EOLN) {
                        if (d == DELIM_OPEN)
                                mdoc->last->flags &= ~NODE_DELIMO;
                        break;
                }

                /*
                 * The rest of the macro line is only punctuation,
                 * to be handled by append_delims().
                 * If there were no other arguments,
                 * do not allow the first one to suppress spacing,
                 * even if it turns out to be a closing one.
                 */

                if (ac == ARGS_PUNCT) {
                        if (cnt == 0 && (nc == 0 || tok == MDOC_An))
                                mdoc->flags |= MDOC_NODELIMC;
                        break;
                }

                ntok = (tok == MDOC_Fn && !cnt) ?
                    TOKEN_NONE : lookup(mdoc, tok, line, la, p);

                /*
                 * In this case, we've located a submacro and must
                 * execute it.  Close out scope, if open.  If no
                 * elements have been generated, either create one (nc)
                 * or raise a warning.
                 */

                if (ntok != TOKEN_NONE) {
                        if (scope)
                                rew_elem(mdoc, tok);
                        if (nc && ! cnt) {
                                mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
                                rew_last(mdoc, mdoc->last);
                        } else if ( ! nc && ! cnt) {
                                mdoc_argv_free(arg);
                                mandoc_msg(MANDOCERR_MACRO_EMPTY,
                                    line, ppos, "%s", roff_name[tok]);
                        }
                        (*mdoc_macro(ntok)->fp)(mdoc, ntok,
                            line, la, pos, buf);
                        if (nl)
                                append_delims(mdoc, line, pos, buf);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        return;
                }

                /*
                 * Handle punctuation.  Set up our scope, if a word;
                 * rewind the scope, if a delimiter; then append the word.
                 */

                if ((d = mdoc_isdelim(p)) != DELIM_NONE) {
                        /*
                         * If we encounter closing punctuation, no word
                         * has been emitted, no scope is open, and we're
                         * allowed to have an empty element, then start
                         * a new scope.
                         */
                        if ((d == DELIM_CLOSE ||
                             (d == DELIM_MIDDLE && tok == MDOC_Fl)) &&
                            !cnt && !scope && nc && mayopen) {
                                mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
                                scope = 1;
                                cnt++;
                                if (tok == MDOC_Nm)
                                        mayopen = 0;
                        }
                        /*
                         * Close out our scope, if one is open, before
                         * any punctuation.
                         */
                        if (scope && tok != MDOC_Lk) {
                                rew_elem(mdoc, tok);
                                scope = 0;
                                if (tok == MDOC_Fn)
                                        mayopen = 0;
                        }
                } else if (mayopen && !scope) {
                        mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
                        scope = 1;
                        cnt++;
                }

                dword(mdoc, line, la, p, d,
                    mdoc_macro(tok)->flags & MDOC_JOIN);

                if (ac == ARGS_ALLOC)
                        free(p);

                /*
                 * If the first argument is a closing delimiter,
                 * do not suppress spacing before it.
                 */

                if (firstarg && d == DELIM_CLOSE && !nc)
                        mdoc->last->flags &= ~NODE_DELIMC;
                firstarg = 0;

                /*
                 * `Fl' macros have their scope re-opened with each new
                 * word so that the `-' can be added to each one without
                 * having to parse out spaces.
                 */
                if (scope && tok == MDOC_Fl) {
                        rew_elem(mdoc, tok);
                        scope = 0;
                }
        }

        if (scope && tok != MDOC_Lk) {
                rew_elem(mdoc, tok);
                scope = 0;
        }

        /*
         * If no elements have been collected and we're allowed to have
         * empties (nc), open a scope and close it out.  Otherwise,
         * raise a warning.
         */

        if ( ! cnt) {
                if (nc) {
                        mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
                        rew_last(mdoc, mdoc->last);
                } else {
                        mdoc_argv_free(arg);
                        mandoc_msg(MANDOCERR_MACRO_EMPTY,
                            line, ppos, "%s", roff_name[tok]);
                }
        }
        if (nl)
                append_delims(mdoc, line, pos, buf);
        if (scope)
                rew_elem(mdoc, tok);
}

static void
blk_full(MACRO_PROT_ARGS)
{
        struct mdoc_arg  *arg;
        struct roff_node *blk; /* Our own or a broken block. */
        struct roff_node *head; /* Our own head. */
        struct roff_node *body; /* Our own body. */
        struct roff_node *n;
        char             *p;
        size_t            iarg;
        int               done, la, nl, parsed;
        enum margserr     ac, lac;

        nl = MDOC_NEWLINE & mdoc->flags;

        if (buf[*pos] == '\0' && (tok == MDOC_Sh || tok == MDOC_Ss)) {
                mandoc_msg(MANDOCERR_MACRO_EMPTY,
                    line, ppos, "%s", roff_name[tok]);
                return;
        }

        if ((mdoc_macro(tok)->flags & MDOC_EXPLICIT) == 0) {

                /* Here, tok is one of Sh Ss Nm Nd It. */

                blk = NULL;
                for (n = mdoc->last; n != NULL; n = n->parent) {
                        if (n->flags & NODE_ENDED) {
                                if ( ! (n->flags & NODE_VALID))
                                        n->flags |= NODE_BROKEN;
                                continue;
                        }
                        if (n->type != ROFFT_BLOCK)
                                continue;

                        if (tok == MDOC_It && n->tok == MDOC_Bl) {
                                if (blk != NULL) {
                                        mandoc_msg(MANDOCERR_BLK_BROKEN,
                                            line, ppos, "It breaks %s",
                                            roff_name[blk->tok]);
                                        rew_pending(mdoc, blk);
                                }
                                break;
                        }

                        if (mdoc_macro(n->tok)->flags & MDOC_EXPLICIT) {
                                switch (tok) {
                                case MDOC_Sh:
                                case MDOC_Ss:
                                        mandoc_msg(MANDOCERR_BLK_BROKEN,
                                            line, ppos,
                                            "%s breaks %s", roff_name[tok],
                                            roff_name[n->tok]);
                                        rew_pending(mdoc, n);
                                        n = mdoc->last;
                                        continue;
                                case MDOC_It:
                                        /* Delay in case it's astray. */
                                        blk = n;
                                        continue;
                                default:
                                        break;
                                }
                                break;
                        }

                        /* Here, n is one of Sh Ss Nm Nd It. */

                        if (tok != MDOC_Sh && (n->tok == MDOC_Sh ||
                            (tok != MDOC_Ss && (n->tok == MDOC_Ss ||
                             (tok != MDOC_It && n->tok == MDOC_It)))))
                                break;

                        /* Item breaking an explicit block. */

                        if (blk != NULL) {
                                mandoc_msg(MANDOCERR_BLK_BROKEN, line, ppos,
                                    "It breaks %s", roff_name[blk->tok]);
                                rew_pending(mdoc, blk);
                                blk = NULL;
                        }

                        /* Close out prior implicit scopes. */

                        rew_pending(mdoc, n);
                }

                /* Skip items outside lists. */

                if (tok == MDOC_It && (n == NULL || n->tok != MDOC_Bl)) {
                        mandoc_msg(MANDOCERR_IT_STRAY,
                            line, ppos, "It %s", buf + *pos);
                        roff_elem_alloc(mdoc, line, ppos, ROFF_br);
                        rew_elem(mdoc, ROFF_br);
                        return;
                }
        }

        /*
         * This routine accommodates implicitly- and explicitly-scoped
         * macro openings.  Implicit ones first close out prior scope
         * (seen above).  Delay opening the head until necessary to
         * allow leading punctuation to print.  Special consideration
         * for `It -column', which has phrase-part syntax instead of
         * regular child nodes.
         */

        switch (tok) {
        case MDOC_Sh:
                mdoc->flags &= ~ROFF_NOFILL;
                break;
        case MDOC_Ss:
                mdoc->flags |= ROFF_NONOFILL;
                break;
        default:
                break;
        }
        mdoc_argv(mdoc, line, tok, &arg, pos, buf);
        blk = mdoc_block_alloc(mdoc, line, ppos, tok, arg);
        head = body = NULL;

        /*
         * Exception: Heads of `It' macros in `-diag' lists are not
         * parsed, even though `It' macros in general are parsed.
         */

        parsed = tok != MDOC_It ||
            mdoc->last->parent->tok != MDOC_Bl ||
            mdoc->last->parent->norm->Bl.type != LIST_diag;

        /*
         * The `Nd' macro has all arguments in its body: it's a hybrid
         * of block partial-explicit and full-implicit.  Stupid.
         */

        if (tok == MDOC_Nd) {
                head = roff_head_alloc(mdoc, line, ppos, tok);
                rew_last(mdoc, head);
                body = roff_body_alloc(mdoc, line, ppos, tok);
        }

        if (tok == MDOC_Bk)
                mdoc->flags |= MDOC_KEEP;

        ac = ARGS_EOLN;
        for (;;) {

                /*
                 * If we are right after a tab character,
                 * do not parse the first word for macros.
                 */

                if (mdoc->flags & MDOC_PHRASEQN) {
                        mdoc->flags &= ~MDOC_PHRASEQN;
                        mdoc->flags |= MDOC_PHRASEQF;
                }

                la = *pos;
                lac = ac;
                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);
                if (ac == ARGS_EOLN) {
                        if (lac != ARGS_PHRASE ||
                            ! (mdoc->flags & MDOC_PHRASEQF))
                                break;

                        /*
                         * This line ends in a tab; start the next
                         * column now, with a leading blank.
                         */

                        if (body != NULL)
                                rew_last(mdoc, body);
                        body = roff_body_alloc(mdoc, line, ppos, tok);
                        roff_word_alloc(mdoc, line, ppos, "\\&");
                        break;
                }

                if (tok == MDOC_Bd || tok == MDOC_Bk) {
                        mandoc_msg(MANDOCERR_ARG_EXCESS, line, la,
                            "%s ... %s", roff_name[tok], buf + la);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        break;
                }
                if (tok == MDOC_Rs) {
                        mandoc_msg(MANDOCERR_ARG_SKIP,
                            line, la, "Rs %s", buf + la);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        break;
                }
                if (ac == ARGS_PUNCT)
                        break;

                /*
                 * Emit leading punctuation (i.e., punctuation before
                 * the ROFFT_HEAD) for non-phrase types.
                 */

                if (head == NULL &&
                    ac != ARGS_PHRASE &&
                    mdoc_isdelim(p) == DELIM_OPEN) {
                        dword(mdoc, line, la, p, DELIM_OPEN, 0);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        continue;
                }

                /* Open a head if one hasn't been opened. */

                if (head == NULL)
                        head = roff_head_alloc(mdoc, line, ppos, tok);

                if (ac == ARGS_PHRASE) {

                        /*
                         * If we haven't opened a body yet, rewind the
                         * head; if we have, rewind that instead.
                         */

                        rew_last(mdoc, body == NULL ? head : body);
                        body = roff_body_alloc(mdoc, line, ppos, tok);

                        /* Process to the tab or to the end of the line. */

                        mdoc->flags |= MDOC_PHRASE;
                        parse_rest(mdoc, TOKEN_NONE, line, &la, buf);
                        mdoc->flags &= ~MDOC_PHRASE;

                        /* There may have been `Ta' macros. */

                        while (body->next != NULL)
                                body = body->next;
                        continue;
                }

                done = macro_or_word(mdoc, tok, line, la, pos, buf, p, parsed);
                if (ac == ARGS_ALLOC)
                        free(p);
                if (done)
                        break;
        }

        if (blk->flags & NODE_VALID)
                return;
        if (head == NULL)
                head = roff_head_alloc(mdoc, line, ppos, tok);
        if (nl && tok != MDOC_Bd && tok != MDOC_Bl && tok != MDOC_Rs)
                append_delims(mdoc, line, pos, buf);
        if (body != NULL)
                goto out;
        if (find_pending(mdoc, tok, line, ppos, head))
                return;

        /* Close out scopes to remain in a consistent state. */

        rew_last(mdoc, head);
        body = roff_body_alloc(mdoc, line, ppos, tok);
        if (tok == MDOC_Ss)
                mdoc->flags &= ~ROFF_NONOFILL;

        /*
         * Set up fill mode for display blocks.
         * This needs to be done here up front rather than during
         * validation such that child nodes get the right flags.
         */

        if (tok == MDOC_Bd && arg != NULL) {
                for (iarg = 0; iarg < arg->argc; iarg++) {
                        switch (arg->argv[iarg].arg) {
                        case MDOC_Unfilled:
                        case MDOC_Literal:
                                mdoc->flags |= ROFF_NOFILL;
                                break;
                        case MDOC_Filled:
                        case MDOC_Ragged:
                        case MDOC_Centred:
                                mdoc->flags &= ~ROFF_NOFILL;
                                break;
                        default:
                                continue;
                        }
                        break;
                }
        }
out:
        if (mdoc->flags & MDOC_FREECOL) {
                rew_last(mdoc, body);
                rew_last(mdoc, blk);
                mdoc->flags &= ~MDOC_FREECOL;
        }
}

static void
blk_part_imp(MACRO_PROT_ARGS)
{
        int               done, la, nl;
        enum margserr     ac;
        char             *p;
        struct roff_node *blk; /* saved block context */
        struct roff_node *body; /* saved body context */
        struct roff_node *n;

        nl = MDOC_NEWLINE & mdoc->flags;

        /*
         * A macro that spans to the end of the line.  This is generally
         * (but not necessarily) called as the first macro.  The block
         * has a head as the immediate child, which is always empty,
         * followed by zero or more opening punctuation nodes, then the
         * body (which may be empty, depending on the macro), then zero
         * or more closing punctuation nodes.
         */

        blk = mdoc_block_alloc(mdoc, line, ppos, tok, NULL);
        rew_last(mdoc, roff_head_alloc(mdoc, line, ppos, tok));

        /*
         * Open the body scope "on-demand", that is, after we've
         * processed all our the leading delimiters (open parenthesis,
         * etc.).
         */

        for (body = NULL; ; ) {
                la = *pos;
                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);
                if (ac == ARGS_EOLN || ac == ARGS_PUNCT)
                        break;

                if (body == NULL && mdoc_isdelim(p) == DELIM_OPEN) {
                        dword(mdoc, line, la, p, DELIM_OPEN, 0);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        continue;
                }

                if (body == NULL)
                        body = roff_body_alloc(mdoc, line, ppos, tok);

                done = macro_or_word(mdoc, tok, line, la, pos, buf, p, 1);
                if (ac == ARGS_ALLOC)
                        free(p);
                if (done)
                        break;
        }
        if (body == NULL)
                body = roff_body_alloc(mdoc, line, ppos, tok);

        if (find_pending(mdoc, tok, line, ppos, body))
                return;

        rew_last(mdoc, body);
        if (nl)
                append_delims(mdoc, line, pos, buf);
        rew_pending(mdoc, blk);

        /* Move trailing .Ns out of scope. */

        for (n = body->child; n && n->next; n = n->next)
                /* Do nothing. */ ;
        if (n && n->tok == MDOC_Ns)
                roff_node_relink(mdoc, n);
}

static void
blk_part_exp(MACRO_PROT_ARGS)
{
        int               done, la, nl;
        enum margserr     ac;
        struct roff_node *head; /* keep track of head */
        char             *p;

        nl = MDOC_NEWLINE & mdoc->flags;

        /*
         * The opening of an explicit macro having zero or more leading
         * punctuation nodes; a head with optional single element (the
         * case of `Eo'); and a body that may be empty.
         */

        roff_block_alloc(mdoc, line, ppos, tok);
        head = NULL;
        for (;;) {
                la = *pos;
                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);
                if (ac == ARGS_PUNCT || ac == ARGS_EOLN)
                        break;

                /* Flush out leading punctuation. */

                if (head == NULL && mdoc_isdelim(p) == DELIM_OPEN) {
                        dword(mdoc, line, la, p, DELIM_OPEN, 0);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        continue;
                }

                if (head == NULL) {
                        head = roff_head_alloc(mdoc, line, ppos, tok);
                        if (tok == MDOC_Eo)  /* Not parsed. */
                                dword(mdoc, line, la, p, DELIM_MAX, 0);
                        rew_last(mdoc, head);
                        roff_body_alloc(mdoc, line, ppos, tok);
                        if (tok == MDOC_Eo) {
                                if (ac == ARGS_ALLOC)
                                        free(p);
                                continue;
                        }
                }

                done = macro_or_word(mdoc, tok, line, la, pos, buf, p, 1);
                if (ac == ARGS_ALLOC)
                        free(p);
                if (done)
                        break;
        }

        /* Clean-up to leave in a consistent state. */

        if (head == NULL) {
                rew_last(mdoc, roff_head_alloc(mdoc, line, ppos, tok));
                roff_body_alloc(mdoc, line, ppos, tok);
        }
        if (nl)
                append_delims(mdoc, line, pos, buf);
}

static void
in_line_argn(MACRO_PROT_ARGS)
{
        struct mdoc_arg *arg;
        char            *p;
        enum margserr    ac;
        enum roff_tok    ntok;
        int              state; /* arg#; -1: not yet open; -2: closed */
        int              la, maxargs, nl;

        nl = mdoc->flags & MDOC_NEWLINE;

        /*
         * A line macro that has a fixed number of arguments (maxargs).
         * Only open the scope once the first non-leading-punctuation is
         * found (unless MDOC_IGNDELIM is noted, like in `Pf'), then
         * keep it open until the maximum number of arguments are
         * exhausted.
         */

        switch (tok) {
        case MDOC_Ap:
        case MDOC_Ns:
        case MDOC_Ux:
                maxargs = 0;
                break;
        case MDOC_Bx:
        case MDOC_Es:
        case MDOC_Xr:
                maxargs = 2;
                break;
        default:
                maxargs = 1;
                break;
        }

        mdoc_argv(mdoc, line, tok, &arg, pos, buf);

        state = -1;
        p = NULL;
        for (;;) {
                la = *pos;
                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);

                if ((ac == ARGS_WORD || ac == ARGS_ALLOC) && state == -1 &&
                    (mdoc_macro(tok)->flags & MDOC_IGNDELIM) == 0 &&
                    mdoc_isdelim(p) == DELIM_OPEN) {
                        dword(mdoc, line, la, p, DELIM_OPEN, 0);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        continue;
                }

                if (state == -1 && tok != MDOC_In &&
                    tok != MDOC_St && tok != MDOC_Xr) {
                        mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
                        state = 0;
                }

                if (ac == ARGS_PUNCT || ac == ARGS_EOLN) {
                        if (abs(state) < 2 && tok == MDOC_Pf)
                                mandoc_msg(MANDOCERR_PF_SKIP,
                                    line, ppos, "Pf %s",
                                    p == NULL ? "at eol" : p);
                        break;
                }

                if (state == maxargs) {
                        rew_elem(mdoc, tok);
                        state = -2;
                }

                ntok = (tok == MDOC_Pf && state == 0) ?
                    TOKEN_NONE : lookup(mdoc, tok, line, la, p);

                if (ntok != TOKEN_NONE) {
                        if (state >= 0) {
                                rew_elem(mdoc, tok);
                                state = -2;
                        }
                        (*mdoc_macro(ntok)->fp)(mdoc, ntok,
                            line, la, pos, buf);
                        if (ac == ARGS_ALLOC)
                                free(p);
                        break;
                }

                if (mdoc_macro(tok)->flags & MDOC_IGNDELIM ||
                    mdoc_isdelim(p) == DELIM_NONE) {
                        if (state == -1) {
                                mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
                                state = 1;
                        } else if (state >= 0)
                                state++;
                } else if (state >= 0) {
                        rew_elem(mdoc, tok);
                        state = -2;
                }

                dword(mdoc, line, la, p, DELIM_MAX,
                    mdoc_macro(tok)->flags & MDOC_JOIN);
                if (ac == ARGS_ALLOC)
                        free(p);
                p = mdoc->last->string;
        }

        if (state == -1) {
                mandoc_msg(MANDOCERR_MACRO_EMPTY,
                    line, ppos, "%s", roff_name[tok]);
                return;
        }

        if (state == 0 && tok == MDOC_Pf)
                append_delims(mdoc, line, pos, buf);
        if (state >= 0)
                rew_elem(mdoc, tok);
        if (nl)
                append_delims(mdoc, line, pos, buf);
}

static void
in_line_eoln(MACRO_PROT_ARGS)
{
        struct roff_node        *n;
        struct mdoc_arg         *arg;

        if ((tok == MDOC_Pp || tok == MDOC_Lp) &&
            ! (mdoc->flags & MDOC_SYNOPSIS)) {
                n = mdoc->last;
                if (mdoc->next == ROFF_NEXT_SIBLING)
                        n = n->parent;
                if (n->tok == MDOC_Nm)
                        rew_last(mdoc, n->parent);
        }

        if (buf[*pos] == '\0' &&
            (tok == MDOC_Fd || *roff_name[tok] == '%')) {
                mandoc_msg(MANDOCERR_MACRO_EMPTY,
                    line, ppos, "%s", roff_name[tok]);
                return;
        }

        mdoc_argv(mdoc, line, tok, &arg, pos, buf);
        mdoc_elem_alloc(mdoc, line, ppos, tok, arg);
        if (parse_rest(mdoc, tok, line, pos, buf))
                return;
        rew_elem(mdoc, tok);
}

/*
 * The simplest argument parser available: Parse the remaining
 * words until the end of the phrase or line and return 0
 * or until the next macro, call that macro, and return 1.
 */
static int
parse_rest(struct roff_man *mdoc, enum roff_tok tok,
    int line, int *pos, char *buf)
{
        char            *p;
        int              done, la;
        enum margserr    ac;

        for (;;) {
                la = *pos;
                ac = mdoc_args(mdoc, line, pos, buf, tok, &p);
                if (ac == ARGS_EOLN)
                        return 0;
                done = macro_or_word(mdoc, tok, line, la, pos, buf, p, 1);
                if (ac == ARGS_ALLOC)
                        free(p);
                if (done)
                        return 1;
        }
}

static void
ctx_synopsis(MACRO_PROT_ARGS)
{

        if (~mdoc->flags & (MDOC_SYNOPSIS | MDOC_NEWLINE))
                in_line(mdoc, tok, line, ppos, pos, buf);
        else if (tok == MDOC_Nm)
                blk_full(mdoc, tok, line, ppos, pos, buf);
        else {
                assert(tok == MDOC_Vt);
                blk_part_imp(mdoc, tok, line, ppos, pos, buf);
        }
}

/*
 * Phrases occur within `Bl -column' entries, separated by `Ta' or tabs.
 * They're unusual because they're basically free-form text until a
 * macro is encountered.
 */
static void
phrase_ta(MACRO_PROT_ARGS)
{
        struct roff_node *body, *n;

        /* Make sure we are in a column list or ignore this macro. */

        body = NULL;
        for (n = mdoc->last; n != NULL; n = n->parent) {
                if (n->flags & NODE_ENDED)
                        continue;
                if (n->tok == MDOC_It && n->type == ROFFT_BODY)
                        body = n;
                if (n->tok == MDOC_Bl && n->end == ENDBODY_NOT)
                        break;
        }

        if (n == NULL || n->norm->Bl.type != LIST_column) {
                mandoc_msg(MANDOCERR_TA_STRAY, line, ppos, "Ta");
                return;
        }

        /* Advance to the next column. */

        rew_last(mdoc, body);
        roff_body_alloc(mdoc, line, ppos, MDOC_It);
        parse_rest(mdoc, TOKEN_NONE, line, pos, buf);
}