File: [local] / src / usr.bin / yacc / closure.c (download)
Revision 1.15, Thu May 25 20:11:03 2017 UTC (7 years ago) by tedu
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, OPENBSD_7_3_BASE, OPENBSD_7_3, OPENBSD_7_2_BASE, OPENBSD_7_2, OPENBSD_7_1_BASE, OPENBSD_7_1, OPENBSD_7_0_BASE, OPENBSD_7_0, OPENBSD_6_9_BASE, OPENBSD_6_9, OPENBSD_6_8_BASE, OPENBSD_6_8, OPENBSD_6_7_BASE, OPENBSD_6_7, OPENBSD_6_6_BASE, OPENBSD_6_6, OPENBSD_6_5_BASE, OPENBSD_6_5, OPENBSD_6_4_BASE, OPENBSD_6_4, OPENBSD_6_3_BASE, OPENBSD_6_3, OPENBSD_6_2_BASE, OPENBSD_6_2, HEAD Changes since 1.14: +71 -71 lines
fix a variety of warnings. from Brian Callahan
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/* $OpenBSD: closure.c,v 1.15 2017/05/25 20:11:03 tedu Exp $ */
/* $NetBSD: closure.c,v 1.4 1996/03/19 03:21:29 jtc Exp $ */
/*
* 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. 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.
*/
#include "defs.h"
short *itemset;
short *itemsetend;
unsigned *ruleset;
static unsigned *first_derives;
static unsigned *EFF;
#ifdef DEBUG
static void
print_closure(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(void)
{
int i, j;
unsigned int *rowp;
unsigned int k, word;
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(void)
{
int i, j;
unsigned int *rp;
unsigned int k, cword = 0;
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
static void
set_EFF(void)
{
unsigned int *row;
int symbol, rowsize, i, rule;
short *sp;
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(void)
{
unsigned int *rrow, *vrow;
unsigned int k, cword = 0;
int i, j, rule, rulesetsize, varsetsize;
short *rp;
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);
}
}
}
rrow += rulesetsize;
}
#ifdef DEBUG
print_first_derives();
#endif
free(EFF);
}
void
closure(short *nucleus, int n)
{
unsigned int i, word;
short *csp, *csend;
unsigned int *dsp, *rsp, *rsend;
int rulesetsize;
int ruleno, symbol, itemno;
rulesetsize = WORDSIZE(nrules);
rsend = ruleset + rulesetsize;
memset(ruleset, 0, rulesetsize * sizeof(*ruleset));
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(void)
{
free(itemset);
free(ruleset);
free(first_derives + ntokens * WORDSIZE(nrules));
}