
/* 
 * $Copyright:	$
 * Copyright (c) 1984, 1985, 1986, 1987, 1988, 1989, 1990 
 * Sequent Computer Systems, Inc.   All rights reserved.
 *  
 * This software is furnished under a license and may be used
 * only in accordance with the terms of that license and with the
 * inclusion of the above copyright notice.   This software may not
 * be provided or otherwise made available to, or used by, any
 * other person.  No title to or ownership of the software is
 * hereby transferred.
 */
/*	Copyright (c) 1988 AT&T	*/
/*	  All Rights Reserved  	*/

/*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T	*/
/*	The copyright notice above does not evidence any   	*/
/*	actual or intended publication of such source code.	*/

#ident	"$Header: tree.c 1.4 90/02/27 $ @(#)tree.c	1.0 1989/12"

#include <stdio.h>
#include "symtab.h"

#ifdef CCS
#include "kbd.h"
#define gettxt(a,b)   b
#else
#include <sys/kbd.h>
extern char *gettxt();
#endif

extern int linnum;	/* line number */

struct node *root;
int numnode = 0;

struct node *nalloc();

/*
 * Build nodes in the tree for new strings.
 */

int dup_error = 0;	/*
			 * the line number that is duped by this entry IF
			 * it is a duplicate of something already in
			 * the tree.
			 */

tree(p, input, result)
	register struct node *p;
	register unsigned char *input;
	register unsigned char *result;
{
	register struct node *q;

	dup_error = 0;	/* set initially to zero */
	if (! *input) {
		fprintf(stderr, gettxt("kbdcomp:52", "Internal error in 'tree' (no input).\n"));
		return(E_ERROR);
	}
	q = p;	/* p is the first node at this level */
	while (p && (p->n_val != *input)) {
		/* seek the *i at this level */
		p = p->n_next;
	}
	if (!p) {	/* no node this level */
		/* make p a new node this level, link it AFTER q. */
		p = nalloc();
		if (q) {
			p->n_next = q->n_next;
			q->n_next = p;
		}
		/* make a child node */
		p->n_what.n_child = nalloc();
		if (! (*(input+1))) { /* we're at last character */
			p->n_val = *input;
			p->n_what.n_child->n_flag = N_RESULT;
			p->n_what.n_child->n_what.n_result = strsave(result);
/*
 * Try to keep track of line numbers whenever a result is
 * generated.  It may help when the table has duplicate nodes.
 */
			p->n_what.n_child->n_lnum = linnum;
			return(0);
		}
		else {	/* have to descend */
			p->n_flag = N_CHILD;
			p->n_val = *input++;
			tree(p->n_what.n_child, input, result);
/*
 * Remove null entries generated by the "descent" mechanism.. SIGH...
 */
			if ((! p->n_what.n_child->n_val) &&
				p->n_what.n_child->n_next) {
				q = p->n_what.n_child;
				p->n_what.n_child = q->n_next;
				free(q);
			}
			return(0);
		}
	}
	if (p->n_val != *input) {
		fprintf(stderr, gettxt("kbdcomp:53", "Internal error in 'tree' (n_val != *input)\n"));
		return(E_ERROR);
	}
	/* we have found the node at at this level */
	if (! (*(input+1))) {
		/*
		 * if at "end of string", it's a DUP:  trying to define
		 * a shorter string dup'ing one already in the tree.
		 */
		return(E_DUP);
	}
	if (p->n_flag == N_RESULT) {
		fprintf(stderr, gettxt("kbdcomp:54", "Internal error: bad node type in 'tree'.\n"));
		return(E_ERROR);
	}
	if (p->n_what.n_child) {	/* has a child??? */
		if (p->n_what.n_child->n_flag == N_RESULT) {
			/*
			 * Catch places where we're trying to do a dup
			 * that's LONGER than something already defined.
			 */
			dup_error = p->n_what.n_child->n_lnum;
			return(E_DUP);
		}
		++input;
	}
	else {	/* why no children ? */
		p->n_what.n_child = nalloc();
		p->n_what.n_child->n_flag = N_CHILD;
		p->n_val = *input++;
		if (! *input) {
			fprintf(stderr, gettxt("kbdcomp:55", "Internal error in tree walk (unexpected end of input).\n"));
			return(E_ERROR);
		}
	}
	return(tree(p->n_what.n_child, input, result));
}

char *calloc();

struct node *
nalloc()

{
	struct node *n;

	if (n = (struct node *) calloc(1, sizeof(struct node))) {
		if (!root)
			root = n;
		return(n);
	}
	else {
		fprintf(stderr, gettxt("kbdcomp:56", "Error - calloc failed in 'nalloc'.\n"));
		exit(1);
	}
}

int level = 0;

#if 0	/* Debugging Routines */
showtree(p)

	struct node *p;
{
	while (p) {
		switch (p->n_flag) {
		case N_CHILD:	fprintf(stderr, "C"); break;
		case N_RESULT:	fprintf(stderr, "R"); break;
		case N_EMPTY:	fprintf(stderr, "E"); break;
		default:	fprintf(stderr, "?"); break;
		}
		fprintf(stderr, "-%04d(%04d)", p->n_num, p->n_node);
		dolevel(level);
		switch (p->n_flag) {
		case N_CHILD:	if (!p->n_val)
					fprintf(stderr, gettxt("kbdcomp:57", "(null)\n"));
				else
					fprintf(stderr, "%c\n", p->n_val);
				++level;
				showtree(p->n_what.n_child);
				--level;
				break;
		case N_RESULT:	fprintf(stderr, "%s\n", p->n_what.n_result);
				break;
		case N_EMPTY:	fprintf(stderr, "EMPTY:%03o\n", p->n_val);
				break;
		default:	fprintf(stderr, gettxt("kbdcomp:58", "Unknown Node Type %d\n"), p->n_flag);
				break;
		}
		p = p->n_next;
	}

}

dolevel(i)

	int i;
{
	fprintf(stderr, "%4d ", i);
	while (i--)
		fprintf(stderr, "  ");

}
#endif	/* end of Debugging Routines */

/*
 * Number the nodes of the tree prior to building the output tree.
 * We number a whole level, then descend to each child, in order,
 * and number the level recursively.  This insures that a whole
 * level is contiguous in the output.
 */
numtree(p)

	struct node *p;
{
	register struct node *q;
	register struct node *ick;

	q = p;
	while (q) {
		if (q->n_next) {
			/*
			 * I'm not sure why, but this comes up sometimes.
			 * We just free the "icky node" and continue.
			 * I wish I knew the cause of this...  It does not
			 * seem to be fatal or result in any strangeness
			 * in the output table.
			 */
			if (! q->n_val) { /* && (q->n_flag == N_CHILD)) { */
				ick = q->n_next;
				q->n_next = q->n_next->n_next;
				free(ick);
			}
		}
/*
 * Don't number result nodes - they'll get hoisted!  Empty nodes still
 * get numbered.
 */
		if (q->n_flag != N_RESULT)
			q->n_num = numnode++;
		else
			q->n_num = (-1);
		q = q->n_next;
	}
	q = p;
	while (q) {
		switch (q->n_flag) {
		case N_CHILD:	numtree(q->n_what.n_child);
				break;
/*
 * EMPTY nodes have no children.  With RESULT nodes, we're "there".
 */
		case N_EMPTY:
		case N_RESULT:	break;
		default:	fprintf(stderr, gettxt("kbdcomp:59", "Internal error - unknown node type %d\n"), q->n_flag);
				exit(1);
				break;
		}
		q = q->n_next;
	}
	q = p;
	while (q) {
		switch (q->n_flag) {
		case N_CHILD:	q->n_node = q->n_what.n_child->n_num;
				break;
		case N_EMPTY:
		case N_RESULT:	q->n_node = 0;
				break;
		default:	fprintf(stderr, gettxt("kbdcomp:60", "Internal error - unknown node type(2) %d\n"),
					q->n_flag);
				exit(1);
		}
		q = q->n_next;
	}
}
