/* $OpenBSD: man_macro.c,v 1.111 2023/11/13 19:13:00 schwarze Exp $ */
/*
 * Copyright (c) 2012-2015,2017-2020,2022 Ingo Schwarze <schwarze@openbsd.org>
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2013 Franco Fichtner <franco@lastsummer.de>
 *
 * 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 <sys/types.h>

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

#include "mandoc.h"
#include "roff.h"
#include "man.h"
#include "libmandoc.h"
#include "roff_int.h"
#include "libman.h"

static  void             blk_close(MACRO_PROT_ARGS);
static  void             blk_exp(MACRO_PROT_ARGS);
static  void             blk_imp(MACRO_PROT_ARGS);
static  void             in_line_eoln(MACRO_PROT_ARGS);
static  int              man_args(struct roff_man *, int,
                                int *, char *, char **);
static  void             rew_scope(struct roff_man *, enum roff_tok);

static const struct man_macro man_macros[MAN_MAX - MAN_TH] = {
        { in_line_eoln, MAN_XSCOPE }, /* TH */
        { blk_imp, MAN_XSCOPE | MAN_BSCOPED }, /* SH */
        { blk_imp, MAN_XSCOPE | MAN_BSCOPED }, /* SS */
        { blk_imp, MAN_XSCOPE | MAN_BSCOPED }, /* TP */
        { blk_imp, MAN_XSCOPE | MAN_BSCOPED }, /* TQ */
        { blk_imp, MAN_XSCOPE }, /* LP */
        { blk_imp, MAN_XSCOPE }, /* PP */
        { blk_imp, MAN_XSCOPE }, /* P */
        { blk_imp, MAN_XSCOPE }, /* IP */
        { blk_imp, MAN_XSCOPE }, /* HP */
        { in_line_eoln, MAN_NSCOPED | MAN_ESCOPED | MAN_JOIN }, /* SM */
        { in_line_eoln, MAN_NSCOPED | MAN_ESCOPED | MAN_JOIN }, /* SB */
        { in_line_eoln, 0 }, /* BI */
        { in_line_eoln, 0 }, /* IB */
        { in_line_eoln, 0 }, /* BR */
        { in_line_eoln, 0 }, /* RB */
        { in_line_eoln, MAN_NSCOPED | MAN_ESCOPED | MAN_JOIN }, /* R */
        { in_line_eoln, MAN_NSCOPED | MAN_ESCOPED | MAN_JOIN }, /* B */
        { in_line_eoln, MAN_NSCOPED | MAN_ESCOPED | MAN_JOIN }, /* I */
        { in_line_eoln, 0 }, /* IR */
        { in_line_eoln, 0 }, /* RI */
        { blk_close, MAN_XSCOPE }, /* RE */
        { blk_exp, MAN_XSCOPE }, /* RS */
        { in_line_eoln, MAN_NSCOPED }, /* DT */
        { in_line_eoln, MAN_NSCOPED }, /* UC */
        { in_line_eoln, MAN_NSCOPED }, /* PD */
        { in_line_eoln, MAN_NSCOPED }, /* AT */
        { in_line_eoln, MAN_NSCOPED }, /* in */
        { blk_imp, MAN_XSCOPE }, /* SY */
        { blk_close, MAN_XSCOPE }, /* YS */
        { in_line_eoln, 0 }, /* OP */
        { in_line_eoln, MAN_XSCOPE }, /* EX */
        { in_line_eoln, MAN_XSCOPE }, /* EE */
        { blk_exp, MAN_XSCOPE }, /* UR */
        { blk_close, MAN_XSCOPE }, /* UE */
        { blk_exp, MAN_XSCOPE }, /* MT */
        { blk_close, MAN_XSCOPE }, /* ME */
        { in_line_eoln, 0 }, /* MR */
};


const struct man_macro *
man_macro(enum roff_tok tok)
{
        assert(tok >= MAN_TH && tok <= MAN_MAX);
        return man_macros + (tok - MAN_TH);
}

void
man_unscope(struct roff_man *man, const struct roff_node *to)
{
        struct roff_node *n;

        to = to->parent;
        n = man->last;
        while (n != to) {

                /* Reached the end of the document? */

                if (to == NULL && ! (n->flags & NODE_VALID)) {
                        if (man->flags & (MAN_BLINE | MAN_ELINE) &&
                            man_macro(n->tok)->flags &
                             (MAN_BSCOPED | MAN_NSCOPED)) {
                                mandoc_msg(MANDOCERR_BLK_LINE,
                                    n->line, n->pos,
                                    "EOF breaks %s", roff_name[n->tok]);
                                if (man->flags & MAN_ELINE) {
                                        if (n->parent->type == ROFFT_ROOT ||
                                            (man_macro(n->parent->tok)->flags &
                                            MAN_ESCOPED) == 0)
                                                man->flags &= ~MAN_ELINE;
                                } else {
                                        assert(n->type == ROFFT_HEAD);
                                        n = n->parent;
                                        man->flags &= ~MAN_BLINE;
                                }
                                man->last = n;
                                n = n->parent;
                                roff_node_delete(man, man->last);
                                continue;
                        }
                        if (n->type == ROFFT_BLOCK &&
                            man_macro(n->tok)->fp == blk_exp)
                                mandoc_msg(MANDOCERR_BLK_NOEND,
                                    n->line, n->pos, "%s",
                                    roff_name[n->tok]);
                }

                /*
                 * We might delete the man->last node
                 * in the post-validation phase.
                 * Save a pointer to the parent such that
                 * we know where to continue the iteration.
                 */

                man->last = n;
                n = n->parent;
                man->last->flags |= NODE_VALID;
        }

        /*
         * If we ended up at the parent of the node we were
         * supposed to rewind to, that means the target node
         * got deleted, so add the next node we parse as a child
         * of the parent instead of as a sibling of the target.
         */

        man->next = (man->last == to) ?
            ROFF_NEXT_CHILD : ROFF_NEXT_SIBLING;
}

/*
 * Rewinding entails ascending the parse tree until a coherent point,
 * for example, the `SH' macro will close out any intervening `SS'
 * scopes.  When a scope is closed, it must be validated and actioned.
 */
static void
rew_scope(struct roff_man *man, enum roff_tok tok)
{
        struct roff_node *n;

        /* Preserve empty paragraphs before RS. */

        n = man->last;
        if (tok == MAN_RS && n->child == NULL &&
            (n->tok == MAN_P || n->tok == MAN_PP || n->tok == MAN_LP))
                return;

        for (;;) {
                if (n->type == ROFFT_ROOT)
                        return;
                if (n->flags & NODE_VALID) {
                        n = n->parent;
                        continue;
                }
                if (n->type != ROFFT_BLOCK) {
                        if (n->parent->type == ROFFT_ROOT) {
                                man_unscope(man, n);
                                return;
                        } else {
                                n = n->parent;
                                continue;
                        }
                }
                if (tok != MAN_SH && (n->tok == MAN_SH ||
                    (tok != MAN_SS && (n->tok == MAN_SS ||
                     man_macro(n->tok)->fp == blk_exp))))
                        return;
                man_unscope(man, n);
                n = man->last;
        }
}


/*
 * Close out a generic explicit macro.
 */
void
blk_close(MACRO_PROT_ARGS)
{
        enum roff_tok            ctok, ntok;
        const struct roff_node  *nn;
        char                    *p, *ep;
        int                      cline, cpos, la, nrew, target;

        nrew = 1;
        switch (tok) {
        case MAN_RE:
                ntok = MAN_RS;
                la = *pos;
                if ( ! man_args(man, line, pos, buf, &p))
                        break;
                for (nn = man->last->parent; nn; nn = nn->parent)
                        if (nn->tok == ntok && nn->type == ROFFT_BLOCK)
                                nrew++;
                target = strtol(p, &ep, 10);
                if (*ep != '\0')
                        mandoc_msg(MANDOCERR_ARG_EXCESS, line,
                            la + (buf[la] == '"') + (int)(ep - p),
                            "RE ... %s", ep);
                free(p);
                if (target == 0)
                        target = 1;
                nrew -= target;
                if (nrew < 1) {
                        mandoc_msg(MANDOCERR_RE_NOTOPEN,
                            line, ppos, "RE %d", target);
                        return;
                }
                break;
        case MAN_YS:
                ntok = MAN_SY;
                break;
        case MAN_UE:
                ntok = MAN_UR;
                break;
        case MAN_ME:
                ntok = MAN_MT;
                break;
        default:
                abort();
        }

        for (nn = man->last->parent; nn; nn = nn->parent)
                if (nn->tok == ntok && nn->type == ROFFT_BLOCK && ! --nrew)
                        break;

        if (nn == NULL) {
                mandoc_msg(MANDOCERR_BLK_NOTOPEN,
                    line, ppos, "%s", roff_name[tok]);
                rew_scope(man, MAN_PP);
                if (tok == MAN_RE) {
                        roff_elem_alloc(man, line, ppos, ROFF_br);
                        man->last->flags |= NODE_LINE |
                            NODE_VALID | NODE_ENDED;
                        man->next = ROFF_NEXT_SIBLING;
                }
                return;
        }

        cline = man->last->line;
        cpos = man->last->pos;
        ctok = man->last->tok;
        man_unscope(man, nn);

        if (tok == MAN_RE && nn->head->aux > 0)
                roff_setreg(man->roff, "an-margin", nn->head->aux, '-');

        /* Trailing text. */

        if (buf[*pos] != '\0') {
                roff_word_alloc(man, line, ppos, buf + *pos);
                man->last->flags |= NODE_DELIMC;
                if (mandoc_eos(man->last->string, strlen(man->last->string)))
                        man->last->flags |= NODE_EOS;
        }

        /* Move a trailing paragraph behind the block. */

        if (ctok == MAN_LP || ctok == MAN_PP || ctok == MAN_P) {
                *pos = strlen(buf);
                blk_imp(man, ctok, cline, cpos, pos, buf);
        }

        /* Synopsis blocks need an explicit end marker for spacing. */

        if (tok == MAN_YS && man->last == nn) {
                roff_elem_alloc(man, line, ppos, tok);
                man_unscope(man, man->last);
        }
}

void
blk_exp(MACRO_PROT_ARGS)
{
        struct roff_node *head;
        char            *p;
        int              la;

        if (tok == MAN_RS) {
                rew_scope(man, tok);
                man->flags |= ROFF_NONOFILL;
        }
        roff_block_alloc(man, line, ppos, tok);
        head = roff_head_alloc(man, line, ppos, tok);

        la = *pos;
        if (man_args(man, line, pos, buf, &p)) {
                roff_word_alloc(man, line, la, p);
                if (tok == MAN_RS) {
                        if (roff_getreg(man->roff, "an-margin") == 0)
                                roff_setreg(man->roff, "an-margin",
                                    5 * 24, '=');
                        if ((head->aux = strtod(p, NULL) * 24.0) > 0)
                                roff_setreg(man->roff, "an-margin",
                                    head->aux, '+');
                }
                free(p);
        }

        if (buf[*pos] != '\0')
                mandoc_msg(MANDOCERR_ARG_EXCESS, line, *pos,
                    "%s ... %s", roff_name[tok], buf + *pos);

        man_unscope(man, head);
        roff_body_alloc(man, line, ppos, tok);
        man->flags &= ~ROFF_NONOFILL;
}

/*
 * Parse an implicit-block macro.  These contain a ROFFT_HEAD and a
 * ROFFT_BODY contained within a ROFFT_BLOCK.  Rules for closing out other
 * scopes, such as `SH' closing out an `SS', are defined in the rew
 * routines.
 */
void
blk_imp(MACRO_PROT_ARGS)
{
        int              la;
        char            *p;
        struct roff_node *n;

        rew_scope(man, tok);
        man->flags |= ROFF_NONOFILL;
        if (tok == MAN_SH || tok == MAN_SS)
                man->flags &= ~ROFF_NOFILL;
        roff_block_alloc(man, line, ppos, tok);
        n = roff_head_alloc(man, line, ppos, tok);

        /* Add line arguments. */

        for (;;) {
                la = *pos;
                if ( ! man_args(man, line, pos, buf, &p))
                        break;
                roff_word_alloc(man, line, la, p);
                free(p);
        }

        /*
         * For macros having optional next-line scope,
         * keep the head open if there were no arguments.
         * For `TP' and `TQ', always keep the head open.
         */

        if (man_macro(tok)->flags & MAN_BSCOPED &&
            (tok == MAN_TP || tok == MAN_TQ || n == man->last)) {
                man->flags |= MAN_BLINE;
                return;
        }

        /* Close out the head and open the body. */

        man_unscope(man, n);
        roff_body_alloc(man, line, ppos, tok);
        man->flags &= ~ROFF_NONOFILL;
}

void
in_line_eoln(MACRO_PROT_ARGS)
{
        int              la;
        char            *p;
        struct roff_node *n;

        roff_elem_alloc(man, line, ppos, tok);
        n = man->last;

        if (tok == MAN_EX)
                man->flags |= ROFF_NOFILL;
        else if (tok == MAN_EE)
                man->flags &= ~ROFF_NOFILL;

        for (;;) {
                if (buf[*pos] != '\0' && man->last != n && tok == MAN_PD) {
                        mandoc_msg(MANDOCERR_ARG_EXCESS, line, *pos,
                            "%s ... %s", roff_name[tok], buf + *pos);
                        break;
                }
                la = *pos;
                if ( ! man_args(man, line, pos, buf, &p))
                        break;
                if (man_macro(tok)->flags & MAN_JOIN &&
                    man->last->type == ROFFT_TEXT)
                        roff_word_append(man, p);
                else
                        roff_word_alloc(man, line, la, p);
                free(p);
        }

        /*
         * Append NODE_EOS in case the last snipped argument
         * ends with a dot, e.g. `.IR syslog (3).'
         */

        if (n != man->last &&
            mandoc_eos(man->last->string, strlen(man->last->string)))
                man->last->flags |= NODE_EOS;

        /*
         * If no arguments are specified and this is MAN_ESCOPED (i.e.,
         * next-line scoped), then set our mode to indicate that we're
         * waiting for terms to load into our context.
         */

        if (n == man->last && man_macro(tok)->flags & MAN_ESCOPED) {
                man->flags |= MAN_ELINE;
                return;
        }

        assert(man->last->type != ROFFT_ROOT);
        man->next = ROFF_NEXT_SIBLING;

        /* Rewind our element scope. */

        for ( ; man->last; man->last = man->last->parent) {
                man->last->flags |= NODE_VALID;
                if (man->last == n)
                        break;
        }

        /* Rewind next-line scoped ancestors, if any. */

        if (man_macro(tok)->flags & MAN_ESCOPED)
                man_descope(man, line, ppos, NULL);
}

void
man_endparse(struct roff_man *man)
{
        man_unscope(man, man->meta.first);
}

static int
man_args(struct roff_man *man, int line, int *pos, char *buf, char **v)
{
        char     *start;

        assert(*pos);
        *v = start = buf + *pos;
        assert(' ' != *start);

        if ('\0' == *start)
                return 0;

        *v = roff_getarg(man->roff, v, line, pos);
        return 1;
}