/* * 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 __FBSDID("$FreeBSD$"); #include #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(void) { 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(void) { 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); } } } rrow += rulesetsize; } #ifdef DEBUG print_first_derives(); #endif free(EFF); } void closure(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); 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(void) { free(itemset); free(ruleset); free(first_derives + ntokens * WORDSIZE(nrules)); } #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 *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(void) { 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