Return to roff.c CVS log

Up to [local] / src / usr.bin / mandoc

In theory, Kristaps never intended to write a roff parser,
but in practice, most real legacy man(7)uals are using so much
low level roff that we can't really get away without at least
partially handling some roff instructions.

As doing this in man(7) only has become messy and as even some
mdoc(7) pages need it, start a minimal partial roff preprocessor.
As a first step, move handling of .am[i], .de[i] and .ig there.
Do not use the roff preprocessor for new manuals!

Now that we have three main parser libraries - roff, man and mdoc -
each one having its own error handling is becoming messy, too.
Thus, start unifying message handling in one central place,
introducing a new generic function mmsg().

coded by kristaps@

/*	$Id: roff.c,v 1.1 2010/05/16 00:54:03 schwarze Exp $ */
/*
 * Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * 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 <assert.h>
#include <stdlib.h>
#include <string.h>

#include "mandoc.h"
#include "roff.h"

enum	rofft {
	ROFF_de,
	ROFF_dei,
	ROFF_am,
	ROFF_ami,
	ROFF_ig,
	ROFF_close,
	ROFF_MAX
};

struct	roff {
	struct roffnode	*last; /* leaf of stack */
	mandocmsg	 msg; /* err/warn/fatal messages */
	void		*data; /* privdata for messages */
};

struct	roffnode {
	enum rofft	 tok; /* type of node */
	struct roffnode	*parent; /* up one in stack */
	char		*end; /* custom end-token */
	int		 line; /* parse line */
	int		 col; /* parse col */
};

#define	ROFF_ARGS	 struct roff *r, /* parse ctx */ \
			 enum rofft tok, /* tok of macro */ \
		 	 char **bufp, /* input buffer */ \
			 size_t *szp, /* size of input buffer */ \
			 int ln, /* parse line */ \
			 int ppos /* current pos in buffer */

typedef	enum rofferr (*roffproc)(ROFF_ARGS);

struct	roffmac {
	const char	*name; /* macro name */
	roffproc	 sub; /* child of control black */
	roffproc	 new; /* root of stack (type = ROFF_MAX) */
};

static	enum rofferr	 roff_new_close(ROFF_ARGS);
static	enum rofferr	 roff_new_ig(ROFF_ARGS);
static	enum rofferr	 roff_sub_ig(ROFF_ARGS);

const	struct roffmac	 roffs[ROFF_MAX] = {
	{ "de", roff_sub_ig, roff_new_ig },
	{ "dei", roff_sub_ig, roff_new_ig },
	{ "am", roff_sub_ig, roff_new_ig },
	{ "ami", roff_sub_ig, roff_new_ig },
	{ "ig", roff_sub_ig, roff_new_ig },
	{ ".", NULL, roff_new_close },
};

static	void		 roff_free1(struct roff *);
static	enum rofft	 roff_hash_find(const char *);
static	int		 roffnode_push(struct roff *, 
				enum rofft, int, int);
static	void		 roffnode_pop(struct roff *);
static	enum rofft	 roff_parse(const char *, int *);


/*
 * Look up a roff token by its name.  Returns ROFF_MAX if no macro by
 * the nil-terminated string name could be found.
 */
static enum rofft
roff_hash_find(const char *p)
{
	int		 i;

	/* FIXME: make this be fast and efficient. */

	for (i = 0; i < (int)ROFF_MAX; i++)
		if (0 == strcmp(roffs[i].name, p))
			return((enum rofft)i);

	return(ROFF_MAX);
}


/*
 * Pop the current node off of the stack of roff instructions currently
 * pending.
 */
static void
roffnode_pop(struct roff *r)
{
	struct roffnode	*p;

	if (NULL == (p = r->last))
		return;
	r->last = p->parent;
	free(p);
}


/*
 * Push a roff node onto the instruction stack.  This must later be
 * removed with roffnode_pop().
 */
static int
roffnode_push(struct roff *r, enum rofft tok, int line, int col)
{
	struct roffnode	*p;

	if (NULL == (p = calloc(1, sizeof(struct roffnode)))) {
		(*r->msg)(MANDOCERR_MEM, r->data, line, col, NULL);
		return(0);
	}

	p->tok = tok;
	p->parent = r->last;
	p->line = line;
	p->col = col;

	r->last = p;
	return(1);
}


static void
roff_free1(struct roff *r)
{

	while (r->last)
		roffnode_pop(r);
}


void
roff_reset(struct roff *r)
{

	roff_free1(r);
}


void
roff_free(struct roff *r)
{

	roff_free1(r);
	free(r);
}


struct roff *
roff_alloc(const mandocmsg msg, void *data)
{
	struct roff	*r;

	if (NULL == (r = calloc(1, sizeof(struct roff)))) {
		(*msg)(MANDOCERR_MEM, data, 0, 0, NULL);
		return(0);
	}

	r->msg = msg;
	r->data = data;
	return(r);
}


enum rofferr
roff_parseln(struct roff *r, int ln, char **bufp, size_t *szp)
{
	enum rofft	 t;
	int		 ppos;

	if (NULL != r->last) {
		/*
		 * If there's a node on the stack, then jump directly
		 * into its processing function.
		 */
		t = r->last->tok;
		assert(roffs[t].sub);
		return((*roffs[t].sub)(r, t, bufp, szp, ln, 0));
	} else if ('.' != (*bufp)[0] && NULL == r->last)
		/* Return when in free text without a context. */
		return(ROFF_CONT);

	/* There's nothing on the stack: make us anew. */

	if (ROFF_MAX == (t = roff_parse(*bufp, &ppos)))
		return(ROFF_CONT);

	assert(roffs[t].new);
	return((*roffs[t].new)(r, t, bufp, szp, ln, ppos));
}


/*
 * Parse a roff node's type from the input buffer.  This must be in the
 * form of ".foo xxx" in the usual way.
 */
static enum rofft
roff_parse(const char *buf, int *pos)
{
	int		 j;
	char		 mac[5];
	enum rofft	 t;

	assert('.' == buf[0]);
	*pos = 1;

	while (buf[*pos] && (' ' == buf[*pos] || '\t' == buf[*pos]))
		(*pos)++;

	if ('\0' == buf[*pos])
		return(ROFF_MAX);

	for (j = 0; j < 4; j++, (*pos)++)
		if ('\0' == (mac[j] = buf[*pos]))
			break;
		else if (' ' == buf[*pos])
			break;

	if (j == 4 || j < 1)
		return(ROFF_MAX);

	mac[j] = '\0';

	if (ROFF_MAX == (t = roff_hash_find(mac)))
		return(t);

	while (buf[*pos] && ' ' == buf[*pos])
		(*pos)++;

	return(t);
}


/* ARGSUSED */
static enum rofferr
roff_sub_ig(ROFF_ARGS)
{
	int		 i, j;

	/* Ignore free-text lines. */

	if ('.' != (*bufp)[ppos])
		return(ROFF_IGN);

	if (r->last->end) {
		i = ppos + 1;

		while ((*bufp)[i] && ' ' == (*bufp)[i])
			i++;

		for (j = 0; r->last->end[j]; i++, j++)
			if ((*bufp)[i] != r->last->end[j])
				return(ROFF_IGN);

		if (r->last->end[j])
			return(ROFF_IGN);
		if ((*bufp)[i] && ' ' != (*bufp)[i])
			return(ROFF_IGN);

		while (' ' == (*bufp)[i])
			i++;

	} else if (ROFF_close != roff_parse(*bufp, &i))
		return(ROFF_IGN);

	roffnode_pop(r);

	if ('\0' == (*bufp)[i])
		return(ROFF_IGN);
	if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, i, NULL))
		return(ROFF_ERR);

	return(ROFF_IGN);
}


/* ARGSUSED */
static enum rofferr
roff_new_close(ROFF_ARGS)
{

	if ( ! (*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL))
		return(ROFF_ERR);

	return(ROFF_IGN);
}


/* ARGSUSED */
static enum rofferr
roff_new_ig(ROFF_ARGS)
{
	int		 i;

	if ( ! roffnode_push(r, tok, ln, ppos))
		return(ROFF_ERR);

	if (ROFF_ig != tok) {
		while ((*bufp)[ppos] && ' ' != (*bufp)[ppos])
			ppos++;
		while (' ' == (*bufp)[ppos])
			ppos++;
	}

	i = (int)ppos;

	while ((*bufp)[i] && ' ' != (*bufp)[i])
		i++;

	if (i == (int)ppos)
		return(ROFF_IGN);

	if ((*bufp)[i])
		if ( ! (*r->msg)(MANDOCERR_ARGSLOST, r->data, ln, i, NULL))
			return(ROFF_ERR);

	/*
	 * If the macro has arguments, the first argument (up to the
	 * next whitespace) is interpreted as an argument marking the
	 * macro close.  Thus, `.ig foo' will close at `.foo'.
	 *
	 * NOTE: the closing macro `.foo' in the above case is not
	 * allowed to have leading spaces with old groff!  Thus `.foo'
	 * != `. foo'.  Oh yeah, everything after the `.foo' is lost.
	 * Merry fucking Christmas.
	 */

	r->last->end = malloc((size_t)(i - ppos) + 1);
	if (NULL == r->last->end) {
		(*r->msg)(MANDOCERR_MEM, r->data, ln, ppos, NULL);
		return(ROFF_ERR);
	}

	memcpy(r->last->end, &(*bufp)[ppos], (size_t)(i - ppos));
	r->last->end[i - ppos] = '\0';

	return(ROFF_IGN);
}


int
roff_endparse(struct roff *r)
{

	if (NULL == r->last)
		return(1);
	return((*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
				r->last->line, r->last->col, NULL));
}