/*      $Id: man.c,v 1.187 2019/01/05 00:36:50 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2013-2015, 2017-2019 Ingo Schwarze <schwarze@openbsd.org>
 * Copyright (c) 2011 Joerg Sonnenberger <joerg@netbsd.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 <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

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

static  char            *man_hasc(char *);
static  int              man_ptext(struct roff_man *, int, char *, int);
static  int              man_pmacro(struct roff_man *, int, char *, int);


int
man_parseln(struct roff_man *man, int ln, char *buf, int offs)
{

        if (man->last->type != ROFFT_EQN || ln > man->last->line)
                man->flags |= MAN_NEWLINE;

        return roff_getcontrol(man->roff, buf, &offs) ?
            man_pmacro(man, ln, buf, offs) :
            man_ptext(man, ln, buf, offs);
}

/*
 * If the string ends with \c, return a pointer to the backslash.
 * Otherwise, return NULL.
 */
static char *
man_hasc(char *start)
{
        char    *cp, *ep;

        ep = strchr(start, '\0') - 2;
        if (ep < start || ep[0] != '\\' || ep[1] != 'c')
                return NULL;
        for (cp = ep; cp > start; cp--)
                if (cp[-1] != '\\')
                        break;
        return (ep - cp) % 2 ? NULL : ep;
}

void
man_descope(struct roff_man *man, int line, int offs, char *start)
{
        /* Trailing \c keeps next-line scope open. */

        if (start != NULL && man_hasc(start) != NULL)
                return;

        /*
         * Co-ordinate what happens with having a next-line scope open:
         * first close out the element scopes (if applicable),
         * then close out the block scope (also if applicable).
         */

        if (man->flags & MAN_ELINE) {
                while (man->last->parent->type != ROFFT_ROOT &&
                    man_macro(man->last->parent->tok)->flags & MAN_ESCOPED)
                        man_unscope(man, man->last->parent);
                man->flags &= ~MAN_ELINE;
        }
        if ( ! (man->flags & MAN_BLINE))
                return;
        man_unscope(man, man->last->parent);
        roff_body_alloc(man, line, offs, man->last->tok);
        man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
}

static int
man_ptext(struct roff_man *man, int line, char *buf, int offs)
{
        int              i;
        char            *ep;

        /* In no-fill mode, whitespace is preserved on text lines. */

        if (man->flags & ROFF_NOFILL) {
                roff_word_alloc(man, line, offs, buf + offs);
                man_descope(man, line, offs, buf + offs);
                return 1;
        }

        for (i = offs; buf[i] == ' '; i++)
                /* Skip leading whitespace. */ ;

        /*
         * Blank lines are ignored in next line scope
         * and right after headings and cancel preceding \c,
         * but add a single vertical space elsewhere.
         */

        if (buf[i] == '\0') {
                if (man->flags & (MAN_ELINE | MAN_BLINE)) {
                        mandoc_msg(MANDOCERR_BLK_BLANK, line, 0, NULL);
                        return 1;
                }
                if (man->last->tok == MAN_SH || man->last->tok == MAN_SS)
                        return 1;
                if (man->last->type == ROFFT_TEXT &&
                    ((ep = man_hasc(man->last->string)) != NULL)) {
                        *ep = '\0';
                        return 1;
                }
                roff_elem_alloc(man, line, offs, ROFF_sp);
                man->next = ROFF_NEXT_SIBLING;
                return 1;
        }

        /*
         * Warn if the last un-escaped character is whitespace. Then
         * strip away the remaining spaces (tabs stay!).
         */

        i = (int)strlen(buf);
        assert(i);

        if (' ' == buf[i - 1] || '\t' == buf[i - 1]) {
                if (i > 1 && '\\' != buf[i - 2])
                        mandoc_msg(MANDOCERR_SPACE_EOL, line, i - 1, NULL);

                for (--i; i && ' ' == buf[i]; i--)
                        /* Spin back to non-space. */ ;

                /* Jump ahead of escaped whitespace. */
                i += '\\' == buf[i] ? 2 : 1;

                buf[i] = '\0';
        }
        roff_word_alloc(man, line, offs, buf + offs);

        /*
         * End-of-sentence check.  If the last character is an unescaped
         * EOS character, then flag the node as being the end of a
         * sentence.  The front-end will know how to interpret this.
         */

        assert(i);
        if (mandoc_eos(buf, (size_t)i))
                man->last->flags |= NODE_EOS;

        man_descope(man, line, offs, buf + offs);
        return 1;
}

static int
man_pmacro(struct roff_man *man, int ln, char *buf, int offs)
{
        struct roff_node *n;
        const char      *cp;
        size_t           sz;
        enum roff_tok    tok;
        int              ppos;
        int              bline;

        /* Determine the line macro. */

        ppos = offs;
        tok = TOKEN_NONE;
        for (sz = 0; sz < 4 && strchr(" \t\\", buf[offs]) == NULL; sz++)
                offs++;
        if (sz > 0 && sz < 4)
                tok = roffhash_find(man->manmac, buf + ppos, sz);
        if (tok == TOKEN_NONE) {
                mandoc_msg(MANDOCERR_MACRO, ln, ppos, "%s", buf + ppos - 1);
                return 1;
        }

        /* Skip a leading escape sequence or tab. */

        switch (buf[offs]) {
        case '\\':
                cp = buf + offs + 1;
                mandoc_escape(&cp, NULL, NULL);
                offs = cp - buf;
                break;
        case '\t':
                offs++;
                break;
        default:
                break;
        }

        /* Jump to the next non-whitespace word. */

        while (buf[offs] == ' ')
                offs++;

        /*
         * Trailing whitespace.  Note that tabs are allowed to be passed
         * into the parser as "text", so we only warn about spaces here.
         */

        if (buf[offs] == '\0' && buf[offs - 1] == ' ')
                mandoc_msg(MANDOCERR_SPACE_EOL, ln, offs - 1, NULL);

        /*
         * Some macros break next-line scopes; otherwise, remember
         * whether we are in next-line scope for a block head.
         */

        man_breakscope(man, tok);
        bline = man->flags & MAN_BLINE;

        /*
         * If the line in next-line scope ends with \c, keep the
         * next-line scope open for the subsequent input line.
         * That is not at all portable, only groff >= 1.22.4
         * does it, but *if* this weird idiom occurs in a manual
         * page, that's very likely what the author intended.
         */

        if (bline && man_hasc(buf + offs))
                bline = 0;

        /* Call to handler... */

        (*man_macro(tok)->fp)(man, tok, ln, ppos, &offs, buf);

        /* In quick mode (for mandocdb), abort after the NAME section. */

        if (man->quick && tok == MAN_SH) {
                n = man->last;
                if (n->type == ROFFT_BODY &&
                    strcmp(n->prev->child->string, "NAME"))
                        return 2;
        }

        /*
         * If we are in a next-line scope for a block head,
         * close it out now and switch to the body,
         * unless the next-line scope is allowed to continue.
         */

        if (bline == 0 ||
            (man->flags & MAN_BLINE) == 0 ||
            man->flags & MAN_ELINE ||
            man_macro(tok)->flags & MAN_NSCOPED)
                return 1;

        man_unscope(man, man->last->parent);
        roff_body_alloc(man, ln, ppos, man->last->tok);
        man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
        return 1;
}

void
man_breakscope(struct roff_man *man, int tok)
{
        struct roff_node *n;

        /*
         * An element next line scope is open,
         * and the new macro is not allowed inside elements.
         * Delete the element that is being broken.
         */

        if (man->flags & MAN_ELINE && (tok < MAN_TH ||
            (man_macro(tok)->flags & MAN_NSCOPED) == 0)) {
                n = man->last;
                if (n->type == ROFFT_TEXT)
                        n = n->parent;
                if (n->tok < MAN_TH ||
                    (man_macro(n->tok)->flags & (MAN_NSCOPED | MAN_ESCOPED))
                     == MAN_NSCOPED)
                        n = n->parent;

                mandoc_msg(MANDOCERR_BLK_LINE, n->line, n->pos,
                    "%s breaks %s", roff_name[tok], roff_name[n->tok]);

                roff_node_delete(man, n);
                man->flags &= ~MAN_ELINE;
        }

        /*
         * Weird special case:
         * Switching fill mode closes section headers.
         */

        if (man->flags & MAN_BLINE &&
            (tok == ROFF_nf || tok == ROFF_fi) &&
            (man->last->tok == MAN_SH || man->last->tok == MAN_SS)) {
                n = man->last;
                man_unscope(man, n);
                roff_body_alloc(man, n->line, n->pos, n->tok);
                man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
        }

        /*
         * A block header next line scope is open,
         * and the new macro is not allowed inside block headers.
         * Delete the block that is being broken.
         */

        if (man->flags & MAN_BLINE && tok != ROFF_nf && tok != ROFF_fi &&
            (tok < MAN_TH || man_macro(tok)->flags & MAN_XSCOPE)) {
                n = man->last;
                if (n->type == ROFFT_TEXT)
                        n = n->parent;
                if (n->tok < MAN_TH ||
                    (man_macro(n->tok)->flags & MAN_XSCOPE) == 0)
                        n = n->parent;

                assert(n->type == ROFFT_HEAD);
                n = n->parent;
                assert(n->type == ROFFT_BLOCK);
                assert(man_macro(n->tok)->flags & MAN_BSCOPED);

                mandoc_msg(MANDOCERR_BLK_LINE, n->line, n->pos,
                    "%s breaks %s", roff_name[tok], roff_name[n->tok]);

                roff_node_delete(man, n);
                man->flags &= ~(MAN_BLINE | ROFF_NONOFILL);
        }
}