414 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			414 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*	$NetBSD: mkpar.c,v 1.12 2009/04/14 09:41:31 lukem Exp $	*/
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| 
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| /*
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|  * Copyright (c) 1989 The Regents of the University of California.
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|  * All rights reserved.
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|  *
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|  * This code is derived from software contributed to Berkeley by
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|  * Robert Paul Corbett.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  * 3. Neither the name of the University nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #include <sys/cdefs.h>
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| #if defined(__RCSID) && !defined(lint)
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| #if 0
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| static char sccsid[] = "@(#)mkpar.c	5.3 (Berkeley) 1/20/91";
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| #else
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| __RCSID("$NetBSD: mkpar.c,v 1.12 2009/04/14 09:41:31 lukem Exp $");
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| #endif
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| #endif /* not lint */
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| 
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| #include "defs.h"
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| 
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| action **parser;
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| int SRtotal;
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| int RRtotal;
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| short *SRconflicts;
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| short *RRconflicts;
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| short *defred;
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| short *rules_used;
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| short nunused;
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| short final_state;
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| 
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| static int SRcount;
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| static int RRcount;
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| 
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| static action *parse_actions(int);
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| static action *get_shifts(int);
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| static action *add_reductions(int, action *);
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| static action *add_reduce(action *, int, int);
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| 
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| static int sole_reduction(int);
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| static void free_action_row(action *);
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| 
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| static void find_final_state(void);
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| static void unused_rules(void);
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| static void remove_conflicts(void);
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| static void total_conflicts(void);
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| static void defreds(void);
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| 
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| 
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| void
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| make_parser(void)
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| {
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|     int i;
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| 
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|     parser = NEW2(nstates, action *);
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|     for (i = 0; i < nstates; i++)
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| 	parser[i] = parse_actions(i);
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| 
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|     find_final_state();
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|     remove_conflicts();
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|     unused_rules();
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|     if (SRtotal + RRtotal > 0) total_conflicts();
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|     defreds();
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| }
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| 
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| 
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| static action *
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| parse_actions(int stateno)
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| {
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|     action *actions;
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| 
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|     actions = get_shifts(stateno);
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|     actions = add_reductions(stateno, actions);
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|     return (actions);
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| }
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| 
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| 
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| static action *
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| get_shifts(int stateno)
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| {
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|     action *actions, *temp;
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|     shifts *sp;
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|     short *state;
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|     int i, k;
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|     int symbol;
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| 
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|     actions = 0;
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|     sp = shift_table[stateno];
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|     if (sp)
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|     {
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| 	state = sp->shift;
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| 	for (i = sp->nshifts - 1; i >= 0; i--)
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| 	{
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| 	    k = state[i];
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| 	    symbol = accessing_symbol[k];
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| 	    if (ISTOKEN(symbol))
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| 	    {
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| 		temp = NEW(action);
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| 		temp->next = actions;
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| 		temp->symbol = symbol;
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| 		temp->number = k;
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| 		temp->prec = symbol_prec[symbol];
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| 		temp->action_code = SHIFT;
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| 		temp->assoc = symbol_assoc[symbol];
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| 		actions = temp;
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| 	    }
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| 	}
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|     }
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|     return (actions);
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| }
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| 
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| static action *
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| add_reductions(int stateno, action *actions)
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| {
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|     int i, j, m, n;
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|     int ruleno, tokensetsize;
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|     unsigned *rowp;
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| 
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|     tokensetsize = WORDSIZE(ntokens);
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|     m = lookaheads[stateno];
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|     n = lookaheads[stateno + 1];
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|     for (i = m; i < n; i++)
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|     {
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| 	ruleno = LAruleno[i];
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| 	rowp = LA + i * tokensetsize;
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| 	for (j = ntokens - 1; j >= 0; j--)
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| 	{
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| 	    if (BIT(rowp, j))
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| 		actions = add_reduce(actions, ruleno, j);
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| 	}
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|     }
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|     return (actions);
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| }
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| 
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| 
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| static action *
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| add_reduce(action *actions, int ruleno, int symbol)
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| {
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|     action *temp, *prev, *next;
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| 
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|     prev = 0;
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|     for (next = actions; next && next->symbol < symbol; next = next->next)
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| 	prev = next;
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| 
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|     while (next && next->symbol == symbol && next->action_code == SHIFT)
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|     {
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| 	prev = next;
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| 	next = next->next;
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|     }
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| 
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|     while (next && next->symbol == symbol &&
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| 	    next->action_code == REDUCE && next->number < ruleno)
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|     {
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| 	prev = next;
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| 	next = next->next;
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|     }
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| 
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|     temp = NEW(action);
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|     temp->next = next;
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|     temp->symbol = symbol;
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|     temp->number = ruleno;
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|     temp->prec = rprec[ruleno];
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|     temp->action_code = REDUCE;
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|     temp->assoc = rassoc[ruleno];
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| 
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|     if (prev)
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| 	prev->next = temp;
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|     else
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| 	actions = temp;
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| 
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|     return (actions);
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| }
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| 
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| 
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| static void
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| find_final_state(void)
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| {
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|     int goal, i;
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|     short *state;
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|     shifts *p;
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| 
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|     p = shift_table[0];
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|     state = p->shift;
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|     goal = ritem[1];
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|     for (i = p->nshifts - 1; i >= 0; --i)
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|     {
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| 	final_state = state[i];
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| 	if (accessing_symbol[final_state] == goal) break;
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|     }
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| }
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| 
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| 
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| static void
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| unused_rules(void)
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| {
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|     int i;
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|     action *p;
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| 
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|     rules_used = (short *) MALLOC(nrules*sizeof(short));
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|     if (rules_used == 0) no_space();
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| 
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|     for (i = 0; i < nrules; ++i)
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| 	rules_used[i] = 0;
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| 
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|     for (i = 0; i < nstates; ++i)
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|     {
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| 	for (p = parser[i]; p; p = p->next)
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| 	{
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| 	    if (p->action_code == REDUCE && p->suppressed == 0)
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| 		rules_used[p->number] = 1;
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| 	}
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|     }
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| 
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|     nunused = 0;
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|     for (i = 3; i < nrules; ++i)
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| 	if (!rules_used[i]) ++nunused;
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| 
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|     if (nunused) {
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| 	if (nunused == 1)
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| 	    fprintf(stderr, "%s: 1 rule never reduced\n", myname);
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| 	else
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| 	    fprintf(stderr, "%s: %d rules never reduced\n", myname, nunused);
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|     }
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| }
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| 
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| 
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| static void
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| remove_conflicts(void)
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| {
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|     int i;
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|     int symbol;
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|     action *p, *pref;
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| 
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|     pref = NULL;
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|     SRtotal = 0;
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|     RRtotal = 0;
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|     SRconflicts = NEW2(nstates, short);
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|     RRconflicts = NEW2(nstates, short);
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|     for (i = 0; i < nstates; i++)
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|     {
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| 	SRcount = 0;
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| 	RRcount = 0;
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| 	symbol = -1;
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| 	for (p = parser[i]; p; p = p->next)
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| 	{
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| 	    if (p->symbol != symbol)
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| 	    {
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| 		pref = p;
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| 		symbol = p->symbol;
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| 	    }
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| 	    else if (i == final_state && symbol == 0)
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| 	    {
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| 		SRcount++;
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| 		p->suppressed = 1;
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| 	    }
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| 	    else 
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| 	    {
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| 		assert(pref != NULL);
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| 		if (pref->action_code == SHIFT)
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| 		{
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| 		    if (pref->prec > 0 && p->prec > 0)
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| 		    {
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| 			if (pref->prec < p->prec)
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| 			{
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| 			    pref->suppressed = 2;
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| 			    pref = p;
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| 			}
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| 			else if (pref->prec > p->prec)
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| 			{
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| 			    p->suppressed = 2;
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| 			}
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| 			else if (pref->assoc == LEFT)
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| 			{
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| 			    pref->suppressed = 2;
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| 			    pref = p;
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| 			}
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| 			else if (pref->assoc == RIGHT)
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| 			{
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| 			    p->suppressed = 2;
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| 			}
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| 			else
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| 			{
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| 			    pref->suppressed = 2;
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| 			    p->suppressed = 2;
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| 			}
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| 		    }
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| 		    else
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| 		    {
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| 			SRcount++;
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| 			p->suppressed = 1;
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| 		    }
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| 		}
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| 		else
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| 		{
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| 		    RRcount++;
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| 		    p->suppressed = 1;
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| 		}
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| 	    }
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| 	}
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| 	SRtotal += SRcount;
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| 	RRtotal += RRcount;
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| 	SRconflicts[i] = SRcount;
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| 	RRconflicts[i] = RRcount;
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|     }
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| }
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| 
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| 
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| static void
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| total_conflicts(void)
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| {
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|     fprintf(stderr, "%s: ", myname);
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|     if (SRtotal == 1)
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| 	fprintf(stderr, "1 shift/reduce conflict");
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|     else if (SRtotal > 1)
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| 	fprintf(stderr, "%d shift/reduce conflicts", SRtotal);
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| 
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|     if (SRtotal && RRtotal)
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| 	fprintf(stderr, ", ");
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| 
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|     if (RRtotal == 1)
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| 	fprintf(stderr, "1 reduce/reduce conflict");
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|     else if (RRtotal > 1)
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| 	fprintf(stderr, "%d reduce/reduce conflicts", RRtotal);
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| 
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|     fprintf(stderr, ".\n");
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| }
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| 
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| 
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| static int
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| sole_reduction(int stateno)
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| {
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|     int count, ruleno;
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|     action *p;
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| 
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|     count = 0;
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|     ruleno = 0; 
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|     for (p = parser[stateno]; p; p = p->next)
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|     {
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| 	if (p->action_code == SHIFT && p->suppressed == 0)
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| 	    return (0);
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| 	else if (p->action_code == REDUCE && p->suppressed == 0)
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| 	{
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| 	    if (ruleno > 0 && p->number != ruleno)
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| 		return (0);
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| 	    if (p->symbol != 1)
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| 		++count;
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| 	    ruleno = p->number;
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| 	}
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|     }
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| 
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|     if (count == 0)
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| 	return (0);
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|     return (ruleno);
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| }
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| 
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| 
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| static void
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| defreds(void)
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| {
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|     int i;
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| 
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|     defred = NEW2(nstates, short);
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|     for (i = 0; i < nstates; i++)
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| 	defred[i] = sole_reduction(i);
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| }
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| 
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| static void 
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| free_action_row(action *p)
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| {
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|   action *q;
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| 
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|   while (p)
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|     {
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|       q = p->next;
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|       FREE(p);
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|       p = q;
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|     }
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| }
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| 
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| void
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| free_parser(void)
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| {
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|   int i;
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| 
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|   for (i = 0; i < nstates; i++)
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|     free_action_row(parser[i]);
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| 
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|   FREE(parser);
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| }
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