FreeBSD-5.3/usr.bin/yacc/closure.c
/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Robert Paul Corbett.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static char sccsid[] = "@(#)closure.c 5.3 (Berkeley) 5/24/93";
#endif
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.bin/yacc/closure.c,v 1.12 2002/04/09 11:39:05 ru Exp $");
#include <stdlib.h>
#include "defs.h"
short *itemset;
short *itemsetend;
unsigned *ruleset;
static void set_EFF(void);
#ifdef DEBUG
static void print_closure(int);
static void print_EFF();
static void print_first_derives();
#endif
static unsigned *first_derives;
static unsigned *EFF;
static void
set_EFF()
{
unsigned *row;
int symbol;
short *sp;
int rowsize;
int i;
int rule;
rowsize = WORDSIZE(nvars);
EFF = NEW2(nvars * rowsize, unsigned);
row = EFF;
for (i = start_symbol; i < nsyms; i++)
{
sp = derives[i];
for (rule = *sp; rule > 0; rule = *++sp)
{
symbol = ritem[rrhs[rule]];
if (ISVAR(symbol))
{
symbol -= start_symbol;
SETBIT(row, symbol);
}
}
row += rowsize;
}
reflexive_transitive_closure(EFF, nvars);
#ifdef DEBUG
print_EFF();
#endif
}
void
set_first_derives()
{
unsigned *rrow;
unsigned *vrow;
int j;
unsigned k;
unsigned cword = 0;
short *rp;
int rule;
int i;
int rulesetsize;
int varsetsize;
rulesetsize = WORDSIZE(nrules);
varsetsize = WORDSIZE(nvars);
first_derives = NEW2(nvars * rulesetsize, unsigned) - ntokens * rulesetsize;
set_EFF();
rrow = first_derives + ntokens * rulesetsize;
for (i = start_symbol; i < nsyms; i++)
{
vrow = EFF + ((i - ntokens) * varsetsize);
k = BITS_PER_WORD;
for (j = start_symbol; j < nsyms; k++, j++)
{
if (k >= BITS_PER_WORD)
{
cword = *vrow++;
k = 0;
}
if (cword & (1 << k))
{
rp = derives[j];
while ((rule = *rp++) >= 0)
{
SETBIT(rrow, rule);
}
}
}
vrow += varsetsize;
rrow += rulesetsize;
}
#ifdef DEBUG
print_first_derives();
#endif
FREE(EFF);
}
void
closure(nucleus, n)
short *nucleus;
int n;
{
int ruleno;
unsigned word;
unsigned i;
short *csp;
unsigned *dsp;
unsigned *rsp;
int rulesetsize;
short *csend;
unsigned *rsend;
int symbol;
int itemno;
rulesetsize = WORDSIZE(nrules);
rsp = ruleset;
rsend = ruleset + rulesetsize;
for (rsp = ruleset; rsp < rsend; rsp++)
*rsp = 0;
csend = nucleus + n;
for (csp = nucleus; csp < csend; ++csp)
{
symbol = ritem[*csp];
if (ISVAR(symbol))
{
dsp = first_derives + symbol * rulesetsize;
rsp = ruleset;
while (rsp < rsend)
*rsp++ |= *dsp++;
}
}
ruleno = 0;
itemsetend = itemset;
csp = nucleus;
for (rsp = ruleset; rsp < rsend; ++rsp)
{
word = *rsp;
if (word)
{
for (i = 0; i < BITS_PER_WORD; ++i)
{
if (word & (1 << i))
{
itemno = rrhs[ruleno+i];
while (csp < csend && *csp < itemno)
*itemsetend++ = *csp++;
*itemsetend++ = itemno;
while (csp < csend && *csp == itemno)
++csp;
}
}
}
ruleno += BITS_PER_WORD;
}
while (csp < csend)
*itemsetend++ = *csp++;
#ifdef DEBUG
print_closure(n);
#endif
}
void
finalize_closure()
{
FREE(itemset);
FREE(ruleset);
FREE(first_derives + ntokens * WORDSIZE(nrules));
}
#ifdef DEBUG
static void
print_closure(n)
int n;
{
short *isp;
printf("\n\nn = %d\n\n", n);
for (isp = itemset; isp < itemsetend; isp++)
printf(" %d\n", *isp);
}
static void
print_EFF()
{
int i, j;
unsigned *rowp;
unsigned word;
unsigned k;
printf("\n\nEpsilon Free Firsts\n");
for (i = start_symbol; i < nsyms; i++)
{
printf("\n%s", symbol_name[i]);
rowp = EFF + ((i - start_symbol) * WORDSIZE(nvars));
word = *rowp++;
k = BITS_PER_WORD;
for (j = 0; j < nvars; k++, j++)
{
if (k >= BITS_PER_WORD)
{
word = *rowp++;
k = 0;
}
if (word & (1 << k))
printf(" %s", symbol_name[start_symbol + j]);
}
}
}
static void
print_first_derives()
{
int i;
int j;
unsigned *rp;
unsigned cword;
unsigned k;
printf("\n\n\nFirst Derives\n");
for (i = start_symbol; i < nsyms; i++)
{
printf("\n%s derives\n", symbol_name[i]);
rp = first_derives + i * WORDSIZE(nrules);
k = BITS_PER_WORD;
for (j = 0; j <= nrules; k++, j++)
{
if (k >= BITS_PER_WORD)
{
cword = *rp++;
k = 0;
}
if (cword & (1 << k))
printf(" %d\n", j);
}
}
fflush(stdout);
}
#endif