1 files changed, 306 insertions, 0 deletions
diff --git a/usr.bin/yacc/closure.c b/usr.bin/yacc/closure.c
new file mode 100644
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--- /dev/null
+++ b/usr.bin/yacc/closure.c
@@ -0,0 +1,306 @@
+/*
+ * 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.
+ * 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("$FreeBSD$");
+
+#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(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