mandoc: update to 1.14.1

[unleashed.git] / bin / mandoc / term.c

/*      $Id: term.c,v 1.259 2017/01/08 18:16:58 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2010-2017 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 <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)
{

        free(p->buf);
        free(p->fontq);
        free(p);
}

void
term_begin(struct termp *p, term_margin head,
                term_margin foot, const struct roff_meta *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_BRTRSP: Consider trailing whitespace significant
 *    when deciding whether the chunk fits or not.
 *  - 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 */

        /*
         * 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.
         */
        dv = p->rmargin > p->offset ? p->rmargin - p->offset : 0;
        maxvis = (int)dv > p->overstep ? dv - (size_t)p->overstep : 0;

        if (p->flags & TERMP_NOBREAK) {
                dv = p->maxrmargin > p->offset ?
                     p->maxrmargin - p->offset : 0;
                bp = (int)dv > p->overstep ?
                     dv - (size_t)p->overstep : 0;
        } else
                bp = 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 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;
                                vend -= 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 (i < p->col && ' ' == 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 > vbl)
                vis -= vbl;
        else
                vis = 0;

        p->col = 0;
        p->overstep = 0;
        p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE);

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

        if (TERMP_HANG & p->flags) {
                p->overstep += (int)(p->offset + vis - p->rmargin +
                    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;

        /* Trailing whitespace is significant in some columns. */
        if (vis && vbl && (TERMP_BRTRSP & p->flags))
                vis += vbl;

        /* 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);
}

/* Swap current and previous font; for \fP and .ft P */
void
term_fontlast(struct termp *p)
{
        enum termfont    f;

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

/* Set font, save current, discard previous; for \f, .ft, .B etc. */
void
term_fontrepl(struct termp *p, enum termfont f)
{

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

/* Set font, save previous. */
void
term_fontpush(struct termp *p, enum termfont f)
{

        p->fontl = p->fontq[p->fonti];
        if (++p->fonti == p->fontsz) {
                p->fontsz += 8;
                p->fontq = mandoc_reallocarray(p->fontq,
                    p->fontsz, sizeof(*p->fontq));
        }
        p->fontq[p->fonti] = f;
}

/* Flush to make the saved pointer current again. */
void
term_fontpopq(struct termp *p, int i)
{

        assert(i >= 0);
        if (p->fonti > i)
                p->fonti = i;
}

/* Pop one font off the stack. */
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;
        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 | TERMP_NONEWLINE);
        p->skipvsp = 0;

        while ('\0' != *word) {
                if ('\\' != *word) {
                        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;

                switch (esc) {
                case ESCAPE_UNICODE:
                        uc = mchars_num2uc(seq + 1, sz - 1);
                        break;
                case ESCAPE_NUMBERED:
                        uc = mchars_num2char(seq, sz);
                        if (uc < 0)
                                continue;
                        break;
                case ESCAPE_SPECIAL:
                        if (p->enc == TERMENC_ASCII) {
                                cp = mchars_spec2str(seq, sz, &ssz);
                                if (cp != NULL)
                                        encode(p, cp, ssz);
                        } else {
                                uc = mchars_spec2cp(seq, sz);
                                if (uc > 0)
                                        encode1(p, uc);
                        }
                        continue;
                case ESCAPE_FONTBOLD:
                        term_fontrepl(p, TERMFONT_BOLD);
                        continue;
                case ESCAPE_FONTITALIC:
                        term_fontrepl(p, TERMFONT_UNDER);
                        continue;
                case ESCAPE_FONTBI:
                        term_fontrepl(p, TERMFONT_BI);
                        continue;
                case ESCAPE_FONT:
                case ESCAPE_FONTROMAN:
                        term_fontrepl(p, TERMFONT_NONE);
                        continue;
                case ESCAPE_FONTPREV:
                        term_fontlast(p);
                        continue;
                case ESCAPE_NOSPACE:
                        if (p->flags & TERMP_BACKAFTER)
                                p->flags &= ~TERMP_BACKAFTER;
                        else if (*word == '\0')
                                p->flags |= (TERMP_NOSPACE | TERMP_NONEWLINE);
                        continue;
                case ESCAPE_SKIPCHAR:
                        p->flags |= TERMP_BACKAFTER;
                        continue;
                case ESCAPE_OVERSTRIKE:
                        cp = seq + sz;
                        while (seq < cp) {
                                if (*seq == '\\') {
                                        mandoc_escape(&seq, NULL, NULL);
                                        continue;
                                }
                                encode1(p, *seq++);
                                if (seq < cp) {
                                        if (p->flags & TERMP_BACKBEFORE)
                                                p->flags |= TERMP_BACKAFTER;
                                        else
                                                p->flags |= TERMP_BACKBEFORE;
                                }
                        }
                        /* Trim trailing backspace/blank pair. */
                        if (p->col > 2 &&
                            (p->buf[p->col - 1] == ' ' ||
                             p->buf[p->col - 1] == '\t'))
                                p->col -= 2;
                        continue;
                default:
                        continue;
                }

                /*
                 * Common handling for Unicode and numbered
                 * character escape sequences.
                 */

                if (p->enc == TERMENC_ASCII) {
                        cp = ascii_uc2str(uc);
                        encode(p, cp, strlen(cp));
                } else {
                        if ((uc < 0x20 && uc != 0x09) ||
                            (uc > 0x7E && uc < 0xA0))
                                uc = 0xFFFD;
                        encode1(p, uc);
                }
        }
        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 (p->col + 7 >= p->maxcols)
                adjbuf(p, p->col + 7);

        f = (c == ASCII_HYPH || c > 127 || isgraph(c)) ?
            p->fontq[p->fonti] : TERMFONT_NONE;

        if (p->flags & TERMP_BACKBEFORE) {
                if (p->buf[p->col - 1] == ' ' || p->buf[p->col - 1] == '\t')
                        p->col--;
                else
                        p->buf[p->col++] = 8;
                p->flags &= ~TERMP_BACKBEFORE;
        }
        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;
        if (p->flags & TERMP_BACKAFTER) {
                p->flags |= TERMP_BACKBEFORE;
                p->flags &= ~TERMP_BACKAFTER;
        }
}

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

        if (p->col + 2 + (sz * 5) >= p->maxcols)
                adjbuf(p, p->col + 2 + (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];

                        /*
                         * Postpone the effect of \z while handling
                         * an overstrike sequence from ascii_uc2str().
                         */

                        if (word[i] == '\b' &&
                            (p->flags & TERMP_BACKBEFORE)) {
                                p->flags &= ~TERMP_BACKBEFORE;
                                p->flags |= TERMP_BACKAFTER;
                        }
                }
        }
}

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

        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, uc;
        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;

                        rhs = NULL;

                        switch (esc) {
                        case ESCAPE_UNICODE:
                                uc = mchars_num2uc(seq + 1, ssz - 1);
                                break;
                        case ESCAPE_NUMBERED:
                                uc = mchars_num2char(seq, ssz);
                                if (uc < 0)
                                        continue;
                                break;
                        case ESCAPE_SPECIAL:
                                if (p->enc == TERMENC_ASCII) {
                                        rhs = mchars_spec2str(seq, ssz, &rsz);
                                        if (rhs != NULL)
                                                break;
                                } else {
                                        uc = mchars_spec2cp(seq, ssz);
                                        if (uc > 0)
                                                sz += cond_width(p, uc, &skip);
                                }
                                continue;
                        case ESCAPE_SKIPCHAR:
                                skip = 1;
                                continue;
                        case ESCAPE_OVERSTRIKE:
                                rsz = 0;
                                rhs = seq + ssz;
                                while (seq < rhs) {
                                        if (*seq == '\\') {
                                                mandoc_escape(&seq, NULL, NULL);
                                                continue;
                                        }
                                        i = (*p->width)(p, *seq++);
                                        if (rsz < i)
                                                rsz = i;
                                }
                                sz += rsz;
                                continue;
                        default:
                                continue;
                        }

                        /*
                         * Common handling for Unicode and numbered
                         * character escape sequences.
                         */

                        if (rhs == NULL) {
                                if (p->enc == TERMENC_ASCII) {
                                        rhs = ascii_uc2str(uc);
                                        rsz = strlen(rhs);
                                } else {
                                        if ((uc < 0x20 && uc != 0x09) ||
                                            (uc > 0x7E && uc < 0xA0))
                                                uc = 0xFFFD;
                                        sz += cond_width(p, uc, &skip);
                                        continue;
                                }
                        }

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

                        /*
                         * Common handling for all escape sequences
                         * printing more than one character.
                         */

                        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++;
                        break;
                default:
                        break;
                }
        }

        return sz;
}

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

        switch (su->unit) {
        case SCALE_BU:
                r = su->scale / 40.0;
                break;
        case SCALE_CM:
                r = su->scale * 6.0 / 2.54;
                break;
        case SCALE_FS:
                r = su->scale * 65536.0 / 40.0;
                break;
        case SCALE_IN:
                r = su->scale * 6.0;
                break;
        case SCALE_MM:
                r = su->scale * 0.006;
                break;
        case SCALE_PC:
                r = su->scale;
                break;
        case SCALE_PT:
                r = su->scale / 12.0;
                break;
        case SCALE_EN:
        case SCALE_EM:
                r = su->scale * 0.6;
                break;
        case SCALE_VS:
                r = su->scale;
                break;
        default:
                abort();
        }
        ri = r > 0.0 ? r + 0.4995 : r - 0.4995;
        return ri < 66 ? ri : 1;
}

/*
 * Convert a scaling width to basic units, rounding down.
 */
int
term_hspan(const struct termp *p, const struct roffsu *su)
{

        return (*p->hspan)(p, su);
}