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Revision 1.248, Wed Apr 29 18:35:00 2015 UTC (8 years, 11 months ago) by schwarze
Branch: MAIN
Changes since 1.247: +27 -43 lines

Replace the kludge for the \z escape sequence by an actual
implementation.  As a side effect, minus ten lines of code.

As another side effect, this also fixes the assertion failure that
used to be triggered by "\z\o'ab'c" at the beginning of an output
line, found by jsg@ with afl (test case 022/Apr27).

/*	$Id: term.c,v 1.248 2015/04/29 18:35:00 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2010-2015 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_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 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;

	/* 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(enum termfont *));
	}
	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(p->symtab,
				    seq, sz, &ssz);
				if (cp != NULL)
					encode(p, cp, ssz);
			} else {
				uc = mchars_spec2cp(p->symtab, 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:
			/* FALLTHROUGH */
		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;
				}
			}
			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 || isgraph(c)) ?
	    p->fontq[p->fonti] : TERMFONT_NONE;

	if (p->flags & TERMP_BACKBEFORE) {
		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];
	}
}

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(p->symtab,
					    seq, ssz, &rsz);
					if (rhs != NULL)
						break;
				} else {
					uc = mchars_spec2cp(p->symtab,
					    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++;
			/* FALLTHROUGH */
		case ASCII_BREAK:
			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:
		/* FALLTHROUGH */
	case SCALE_EM:
		r = su->scale * 0.6;
		break;
	case SCALE_VS:
		r = su->scale;
		break;
	default:
		abort();
		/* NOTREACHED */
	}
	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));
}