exports.5: network prefixlength (CIDR) format is supported

[dragonfly.git] / contrib / mdocml / term.c

/*      $Id: term.c,v 1.226 2014/08/01 19:38:29 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2010-2014 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 AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h>

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

#include "mandoc.h"
#include "mandoc_aux.h"
#include "out.h"
#include "term.h"
#include "main.h"

static  size_t           cond_width(const struct termp *, int, int *);
static  void             adjbuf(struct termp *p, size_t);
static  void             bufferc(struct termp *, char);
static  void             encode(struct termp *, const char *, size_t);
static  void             encode1(struct termp *, int);


void
term_free(struct termp *p)
{

        if (p->buf)
                free(p->buf);
        if (p->symtab)
                mchars_free(p->symtab);

        free(p);
}

void
term_begin(struct termp *p, term_margin head,
                term_margin foot, const void *arg)
{

        p->headf = head;
        p->footf = foot;
        p->argf = arg;
        (*p->begin)(p);
}

void
term_end(struct termp *p)
{

        (*p->end)(p);
}

/*
 * Flush a chunk of text.  By default, break the output line each time
 * the right margin is reached, and continue output on the next line
 * at the same offset as the chunk itself.  By default, also break the
 * output line at the end of the chunk.
 * The following flags may be specified:
 *
 *  - TERMP_NOBREAK: Do not break the output line at the right margin,
 *    but only at the max right margin.  Also, do not break the output
 *    line at the end of the chunk, such that the next call can pad to
 *    the next column.  However, if less than p->trailspace blanks,
 *    which can be 0, 1, or 2, remain to the right margin, the line
 *    will be broken.
 *  - TERMP_BRIND: If the chunk does not fit and the output line has
 *    to be broken, start the next line at the right margin instead
 *    of at the offset.  Used together with TERMP_NOBREAK for the tags
 *    in various kinds of tagged lists.
 *  - TERMP_DANGLE: Do not break the output line at the right margin,
 *    append the next chunk after it even if this one is too long.
 *    To be used together with TERMP_NOBREAK.
 *  - TERMP_HANG: Like TERMP_DANGLE, and also suppress padding before
 *    the next chunk if this column is not full.
 */
void
term_flushln(struct termp *p)
{
        size_t           i;     /* current input position in p->buf */
        int              ntab;  /* number of tabs to prepend */
        size_t           vis;   /* current visual position on output */
        size_t           vbl;   /* number of blanks to prepend to output */
        size_t           vend;  /* end of word visual position on output */
        size_t           bp;    /* visual right border position */
        size_t           dv;    /* temporary for visual pos calculations */
        size_t           j;     /* temporary loop index for p->buf */
        size_t           jhy;   /* last hyph before overflow w/r/t j */
        size_t           maxvis; /* output position of visible boundary */
        size_t           mmax; /* used in calculating bp */

        /*
         * First, establish the maximum columns of "visible" content.
         * This is usually the difference between the right-margin and
         * an indentation, but can be, for tagged lists or columns, a
         * small set of values.
         *
         * The following unsigned-signed subtractions look strange,
         * but they are actually correct.  If the int p->overstep
         * is negative, it gets sign extended.  Subtracting that
         * very large size_t effectively adds a small number to dv.
         */
        assert  (p->rmargin >= p->offset);
        dv     = p->rmargin - p->offset;
        maxvis = (int)dv > p->overstep ? dv - (size_t)p->overstep : 0;
        dv     = p->maxrmargin - p->offset;
        mmax   = (int)dv > p->overstep ? dv - (size_t)p->overstep : 0;

        bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;

        /*
         * Calculate the required amount of padding.
         */
        vbl = p->offset + p->overstep > p->viscol ?
              p->offset + p->overstep - p->viscol : 0;

        vis = vend = 0;
        i = 0;

        while (i < p->col) {
                /*
                 * Handle literal tab characters: collapse all
                 * subsequent tabs into a single huge set of spaces.
                 */
                ntab = 0;
                while (i < p->col && '\t' == p->buf[i]) {
                        vend = (vis / p->tabwidth + 1) * p->tabwidth;
                        vbl += vend - vis;
                        vis = vend;
                        ntab++;
                        i++;
                }

                /*
                 * Count up visible word characters.  Control sequences
                 * (starting with the CSI) aren't counted.  A space
                 * generates a non-printing word, which is valid (the
                 * space is printed according to regular spacing rules).
                 */

                for (j = i, jhy = 0; j < p->col; j++) {
                        if (' ' == p->buf[j] || '\t' == p->buf[j])
                                break;

                        /* Back over the the last printed character. */
                        if (8 == p->buf[j]) {
                                assert(j);
                                vend -= (*p->width)(p, p->buf[j - 1]);
                                continue;
                        }

                        /* Regular word. */
                        /* Break at the hyphen point if we overrun. */
                        if (vend > vis && vend < bp &&
                            (ASCII_HYPH == p->buf[j] ||
                             ASCII_BREAK == p->buf[j]))
                                jhy = j;

                        /*
                         * Hyphenation now decided, put back a real
                         * hyphen such that we get the correct width.
                         */
                        if (ASCII_HYPH == p->buf[j])
                                p->buf[j] = '-';

                        vend += (*p->width)(p, p->buf[j]);
                }

                /*
                 * Find out whether we would exceed the right margin.
                 * If so, break to the next line.
                 */
                if (vend > bp && 0 == jhy && vis > 0) {
                        vend -= vis;
                        (*p->endline)(p);
                        p->viscol = 0;
                        if (TERMP_BRIND & p->flags) {
                                vbl = p->rmargin;
                                vend += p->rmargin - p->offset;
                        } else
                                vbl = p->offset;

                        /* use pending tabs on the new line */

                        if (0 < ntab)
                                vbl += ntab * p->tabwidth;

                        /*
                         * Remove the p->overstep width.
                         * Again, if p->overstep is negative,
                         * sign extension does the right thing.
                         */

                        bp += (size_t)p->overstep;
                        p->overstep = 0;
                }

                /* Write out the [remaining] word. */
                for ( ; i < p->col; i++) {
                        if (vend > bp && jhy > 0 && i > jhy)
                                break;
                        if ('\t' == p->buf[i])
                                break;
                        if (' ' == p->buf[i]) {
                                j = i;
                                while (' ' == p->buf[i])
                                        i++;
                                dv = (i - j) * (*p->width)(p, ' ');
                                vbl += dv;
                                vend += dv;
                                break;
                        }
                        if (ASCII_NBRSP == p->buf[i]) {
                                vbl += (*p->width)(p, ' ');
                                continue;
                        }
                        if (ASCII_BREAK == p->buf[i])
                                continue;

                        /*
                         * Now we definitely know there will be
                         * printable characters to output,
                         * so write preceding white space now.
                         */
                        if (vbl) {
                                (*p->advance)(p, vbl);
                                p->viscol += vbl;
                                vbl = 0;
                        }

                        (*p->letter)(p, p->buf[i]);
                        if (8 == p->buf[i])
                                p->viscol -= (*p->width)(p, p->buf[i-1]);
                        else
                                p->viscol += (*p->width)(p, p->buf[i]);
                }
                vis = vend;
        }

        /*
         * If there was trailing white space, it was not printed;
         * so reset the cursor position accordingly.
         */
        if (vis)
                vis -= vbl;

        p->col = 0;
        p->overstep = 0;

        if ( ! (TERMP_NOBREAK & p->flags)) {
                p->viscol = 0;
                (*p->endline)(p);
                return;
        }

        if (TERMP_HANG & p->flags) {
                p->overstep = (int)(vis - maxvis +
                    p->trailspace * (*p->width)(p, ' '));

                /*
                 * If we have overstepped the margin, temporarily move
                 * it to the right and flag the rest of the line to be
                 * shorter.
                 * If there is a request to keep the columns together,
                 * allow negative overstep when the column is not full.
                 */
                if (p->trailspace && p->overstep < 0)
                        p->overstep = 0;
                return;

        } else if (TERMP_DANGLE & p->flags)
                return;

        /* If the column was overrun, break the line. */
        if (maxvis < vis + p->trailspace * (*p->width)(p, ' ')) {
                (*p->endline)(p);
                p->viscol = 0;
        }
}

/*
 * A newline only breaks an existing line; it won't assert vertical
 * space.  All data in the output buffer is flushed prior to the newline
 * assertion.
 */
void
term_newln(struct termp *p)
{

        p->flags |= TERMP_NOSPACE;
        if (p->col || p->viscol)
                term_flushln(p);
}

/*
 * Asserts a vertical space (a full, empty line-break between lines).
 * Note that if used twice, this will cause two blank spaces and so on.
 * All data in the output buffer is flushed prior to the newline
 * assertion.
 */
void
term_vspace(struct termp *p)
{

        term_newln(p);
        p->viscol = 0;
        if (0 < p->skipvsp)
                p->skipvsp--;
        else
                (*p->endline)(p);
}

void
term_fontlast(struct termp *p)
{
        enum termfont    f;

        f = p->fontl;
        p->fontl = p->fontq[p->fonti];
        p->fontq[p->fonti] = f;
}

void
term_fontrepl(struct termp *p, enum termfont f)
{

        p->fontl = p->fontq[p->fonti];
        p->fontq[p->fonti] = f;
}

void
term_fontpush(struct termp *p, enum termfont f)
{

        assert(p->fonti + 1 < 10);
        p->fontl = p->fontq[p->fonti];
        p->fontq[++p->fonti] = f;
}

const void *
term_fontq(struct termp *p)
{

        return(&p->fontq[p->fonti]);
}

enum termfont
term_fonttop(struct termp *p)
{

        return(p->fontq[p->fonti]);
}

void
term_fontpopq(struct termp *p, const void *key)
{

        while (p->fonti >= 0 && key < (void *)(p->fontq + p->fonti))
                p->fonti--;
        assert(p->fonti >= 0);
}

void
term_fontpop(struct termp *p)
{

        assert(p->fonti);
        p->fonti--;
}

/*
 * Handle pwords, partial words, which may be either a single word or a
 * phrase that cannot be broken down (such as a literal string).  This
 * handles word styling.
 */
void
term_word(struct termp *p, const char *word)
{
        const char       nbrsp[2] = { ASCII_NBRSP, 0 };
        const char      *seq, *cp;
        char             c;
        int              sz, uc;
        size_t           ssz;
        enum mandoc_esc  esc;

        if ( ! (TERMP_NOSPACE & p->flags)) {
                if ( ! (TERMP_KEEP & p->flags)) {
                        bufferc(p, ' ');
                        if (TERMP_SENTENCE & p->flags)
                                bufferc(p, ' ');
                } else
                        bufferc(p, ASCII_NBRSP);
        }
        if (TERMP_PREKEEP & p->flags)
                p->flags |= TERMP_KEEP;

        if ( ! (p->flags & TERMP_NONOSPACE))
                p->flags &= ~TERMP_NOSPACE;
        else
                p->flags |= TERMP_NOSPACE;

        p->flags &= ~TERMP_SENTENCE;

        while ('\0' != *word) {
                if ('\\' != *word) {
                        if (TERMP_SKIPCHAR & p->flags) {
                                p->flags &= ~TERMP_SKIPCHAR;
                                word++;
                                continue;
                        }
                        if (TERMP_NBRWORD & p->flags) {
                                if (' ' == *word) {
                                        encode(p, nbrsp, 1);
                                        word++;
                                        continue;
                                }
                                ssz = strcspn(word, "\\ ");
                        } else
                                ssz = strcspn(word, "\\");
                        encode(p, word, ssz);
                        word += (int)ssz;
                        continue;
                }

                word++;
                esc = mandoc_escape(&word, &seq, &sz);
                if (ESCAPE_ERROR == esc)
                        continue;

                if (TERMENC_ASCII != p->enc)
                        switch (esc) {
                        case ESCAPE_UNICODE:
                                uc = mchars_num2uc(seq + 1, sz - 1);
                                if ('\0' == uc)
                                        break;
                                encode1(p, uc);
                                continue;
                        case ESCAPE_SPECIAL:
                                uc = mchars_spec2cp(p->symtab, seq, sz);
                                if (uc <= 0)
                                        break;
                                encode1(p, uc);
                                continue;
                        default:
                                break;
                        }

                switch (esc) {
                case ESCAPE_UNICODE:
                        encode1(p, '?');
                        break;
                case ESCAPE_NUMBERED:
                        c = mchars_num2char(seq, sz);
                        if ('\0' != c)
                                encode(p, &c, 1);
                        break;
                case ESCAPE_SPECIAL:
                        cp = mchars_spec2str(p->symtab, seq, sz, &ssz);
                        if (NULL != cp)
                                encode(p, cp, ssz);
                        else if (1 == ssz)
                                encode(p, seq, sz);
                        break;
                case ESCAPE_FONTBOLD:
                        term_fontrepl(p, TERMFONT_BOLD);
                        break;
                case ESCAPE_FONTITALIC:
                        term_fontrepl(p, TERMFONT_UNDER);
                        break;
                case ESCAPE_FONTBI:
                        term_fontrepl(p, TERMFONT_BI);
                        break;
                case ESCAPE_FONT:
                        /* FALLTHROUGH */
                case ESCAPE_FONTROMAN:
                        term_fontrepl(p, TERMFONT_NONE);
                        break;
                case ESCAPE_FONTPREV:
                        term_fontlast(p);
                        break;
                case ESCAPE_NOSPACE:
                        if (TERMP_SKIPCHAR & p->flags)
                                p->flags &= ~TERMP_SKIPCHAR;
                        else if ('\0' == *word)
                                p->flags |= TERMP_NOSPACE;
                        break;
                case ESCAPE_SKIPCHAR:
                        p->flags |= TERMP_SKIPCHAR;
                        break;
                default:
                        break;
                }
        }
        p->flags &= ~TERMP_NBRWORD;
}

static void
adjbuf(struct termp *p, size_t sz)
{

        if (0 == p->maxcols)
                p->maxcols = 1024;
        while (sz >= p->maxcols)
                p->maxcols <<= 2;

        p->buf = mandoc_reallocarray(p->buf, p->maxcols, sizeof(int));
}

static void
bufferc(struct termp *p, char c)
{

        if (p->col + 1 >= p->maxcols)
                adjbuf(p, p->col + 1);

        p->buf[p->col++] = c;
}

/*
 * See encode().
 * Do this for a single (probably unicode) value.
 * Does not check for non-decorated glyphs.
 */
static void
encode1(struct termp *p, int c)
{
        enum termfont     f;

        if (TERMP_SKIPCHAR & p->flags) {
                p->flags &= ~TERMP_SKIPCHAR;
                return;
        }

        if (p->col + 6 >= p->maxcols)
                adjbuf(p, p->col + 6);

        f = term_fonttop(p);

        if (TERMFONT_UNDER == f || TERMFONT_BI == f) {
                p->buf[p->col++] = '_';
                p->buf[p->col++] = 8;
        }
        if (TERMFONT_BOLD == f || TERMFONT_BI == f) {
                if (ASCII_HYPH == c)
                        p->buf[p->col++] = '-';
                else
                        p->buf[p->col++] = c;
                p->buf[p->col++] = 8;
        }
        p->buf[p->col++] = c;
}

static void
encode(struct termp *p, const char *word, size_t sz)
{
        size_t            i;

        if (TERMP_SKIPCHAR & p->flags) {
                p->flags &= ~TERMP_SKIPCHAR;
                return;
        }

        /*
         * Encode and buffer a string of characters.  If the current
         * font mode is unset, buffer directly, else encode then buffer
         * character by character.
         */

        if (TERMFONT_NONE == term_fonttop(p)) {
                if (p->col + sz >= p->maxcols)
                        adjbuf(p, p->col + sz);
                for (i = 0; i < sz; i++)
                        p->buf[p->col++] = word[i];
                return;
        }

        /* Pre-buffer, assuming worst-case. */

        if (p->col + 1 + (sz * 5) >= p->maxcols)
                adjbuf(p, p->col + 1 + (sz * 5));

        for (i = 0; i < sz; i++) {
                if (ASCII_HYPH == word[i] ||
                    isgraph((unsigned char)word[i]))
                        encode1(p, word[i]);
                else
                        p->buf[p->col++] = word[i];
        }
}

void
term_setwidth(struct termp *p, const char *wstr)
{
        struct roffsu    su;
        size_t           width;
        int              iop;

        iop = 0;
        width = 0;
        if (NULL != wstr) {
                switch (*wstr) {
                case '+':
                        iop = 1;
                        wstr++;
                        break;
                case '-':
                        iop = -1;
                        wstr++;
                        break;
                default:
                        break;
                }
                if (a2roffsu(wstr, &su, SCALE_MAX))
                        width = term_hspan(p, &su);
                else
                        iop = 0;
        }
        (*p->setwidth)(p, iop, width);
}

size_t
term_len(const struct termp *p, size_t sz)
{

        return((*p->width)(p, ' ') * sz);
}

static size_t
cond_width(const struct termp *p, int c, int *skip)
{

        if (*skip) {
                (*skip) = 0;
                return(0);
        } else
                return((*p->width)(p, c));
}

size_t
term_strlen(const struct termp *p, const char *cp)
{
        size_t           sz, rsz, i;
        int              ssz, skip, c;
        const char      *seq, *rhs;
        enum mandoc_esc  esc;
        static const char rej[] = { '\\', ASCII_NBRSP, ASCII_HYPH,
                        ASCII_BREAK, '\0' };

        /*
         * Account for escaped sequences within string length
         * calculations.  This follows the logic in term_word() as we
         * must calculate the width of produced strings.
         */

        sz = 0;
        skip = 0;
        while ('\0' != *cp) {
                rsz = strcspn(cp, rej);
                for (i = 0; i < rsz; i++)
                        sz += cond_width(p, *cp++, &skip);

                switch (*cp) {
                case '\\':
                        cp++;
                        esc = mandoc_escape(&cp, &seq, &ssz);
                        if (ESCAPE_ERROR == esc)
                                continue;

                        if (TERMENC_ASCII != p->enc)
                                switch (esc) {
                                case ESCAPE_UNICODE:
                                        c = mchars_num2uc(seq + 1,
                                            ssz - 1);
                                        if ('\0' == c)
                                                break;
                                        sz += cond_width(p, c, &skip);
                                        continue;
                                case ESCAPE_SPECIAL:
                                        c = mchars_spec2cp(p->symtab,
                                            seq, ssz);
                                        if (c <= 0)
                                                break;
                                        sz += cond_width(p, c, &skip);
                                        continue;
                                default:
                                        break;
                                }

                        rhs = NULL;

                        switch (esc) {
                        case ESCAPE_UNICODE:
                                sz += cond_width(p, '?', &skip);
                                break;
                        case ESCAPE_NUMBERED:
                                c = mchars_num2char(seq, ssz);
                                if ('\0' != c)
                                        sz += cond_width(p, c, &skip);
                                break;
                        case ESCAPE_SPECIAL:
                                rhs = mchars_spec2str(p->symtab,
                                    seq, ssz, &rsz);

                                if (ssz != 1 || rhs)
                                        break;

                                rhs = seq;
                                rsz = ssz;
                                break;
                        case ESCAPE_SKIPCHAR:
                                skip = 1;
                                break;
                        default:
                                break;
                        }

                        if (NULL == rhs)
                                break;

                        if (skip) {
                                skip = 0;
                                break;
                        }

                        for (i = 0; i < rsz; i++)
                                sz += (*p->width)(p, *rhs++);
                        break;
                case ASCII_NBRSP:
                        sz += cond_width(p, ' ', &skip);
                        cp++;
                        break;
                case ASCII_HYPH:
                        sz += cond_width(p, '-', &skip);
                        cp++;
                        /* FALLTHROUGH */
                case ASCII_BREAK:
                        break;
                default:
                        break;
                }
        }

        return(sz);
}

size_t
term_vspan(const struct termp *p, const struct roffsu *su)
{
        double           r;

        switch (su->unit) {
        case SCALE_CM:
                r = su->scale * 2.0;
                break;
        case SCALE_IN:
                r = su->scale * 6.0;
                break;
        case SCALE_PC:
                r = su->scale;
                break;
        case SCALE_PT:
                r = su->scale / 8.0;
                break;
        case SCALE_MM:
                r = su->scale / 1000.0;
                break;
        case SCALE_VS:
                r = su->scale;
                break;
        default:
                r = su->scale - 1.0;
                break;
        }

        if (r < 0.0)
                r = 0.0;
        return((size_t)(r + 0.0005));
}

size_t
term_hspan(const struct termp *p, const struct roffsu *su)
{
        double           v;

        v = (*p->hspan)(p, su);
        if (v < 0.0)
                v = 0.0;
        return((size_t)(v + 0.0005));
}