Plan 9 from Bell Labs’s /usr/web/sources/contrib/cinap_lenrek/push/tree.c

Copyright © 2021 Plan 9 Foundation.
Distributed under the MIT License.
Download the Plan 9 distribution.


#include "rc.h"
#include "exec.h"
#include "io.h"
#include "fns.h"
tree *treenodes;
/*
 * create and clear a new tree node, and add it
 * to the node list.
 */

tree*
newtree(void)
{
	tree *t = new(tree);
	t->iskw = 0;
	t->str = 0;
	t->child[0] = t->child[1] = t->child[2] = 0;
	t->next = treenodes;
	treenodes = t;
	return t;
}

void
freenodes(void)
{
	tree *t, *u;
	for(t = treenodes;t;t = u){
		u = t->next;
		if(t->str)
			efree(t->str);
		efree((char *)t);
	}
	treenodes = 0;
}

tree*
tree1(int type, tree *c0)
{
	return tree3(type, c0, (tree *)0, (tree *)0);
}

tree*
tree2(int type, tree *c0, tree *c1)
{
	return tree3(type, c0, c1, (tree *)0);
}

tree*
tree3(int type, tree *c0, tree *c1, tree *c2)
{
	tree *t;
	if(type==';'){
		if(c0==0)
			return c1;
		if(c1==0)
			return c0;
	}
	t = newtree();
	t->type = type;
	t->child[0] = c0;
	t->child[1] = c1;
	t->child[2] = c2;
	return t;
}

tree*
mung1(tree *t, tree *c0)
{
	t->child[0] = c0;
	return t;
}

tree*
mung2(tree *t, tree *c0, tree *c1)
{
	t->child[0] = c0;
	t->child[1] = c1;
	return t;
}

/*
The majority of Fan in and Fan out are implemented as syntax transformations. 

the fd1 for fanouts and the f0 for fanins are implemented together to make sure they speak correctly. 
*/


tree*
mung3mp(tree *t, tree *c0, tree *c1, tree *c2)
{
	t->type = FANIN;
	t->child[0] = tree1(SIMPLE, 
		tree2(ARGLIST, 
			tree1('$', token("irf", WORD)),
			tree1('$', token("irfds", WORD))));	
	t->child[1] = tree3(FANOUT,
		tree1(SIMPLE,
			tree2(ARGLIST,
				tree1('$', token("orf", WORD)),
				tree1('$', token("orfds", WORD)))),
		c0,
		c1); // filled in later);
			
	t->child[2] = c2;
					
	/* XXX: I have a wild number of fds here, now I need to fix this */
	/* the fanin and fanout have the same number of fds */
	t->child[1]->fd0 = t->fd0;
	t->child[1]->fd1 = t->fd1;
	if(t->fd1 == 0)
		t->child[0]->fd1 = 10; // XXX: fixme! with real value
//	t->child[0]->child[0]->fd0 = t->child[0]->child[0]->fd1;
	return t;
}



tree*
mung3(tree *t, tree *c0, tree *c1, tree *c2)
{
	t->child[0] = c0;
	t->child[1] = c1;
	t->child[2] = c2;
	return t;
}

tree*
epimung(tree *comp, tree *epi)
{
	tree *p;
	if(epi==0)
		return comp;
	for(p = epi;p->child[1];p = p->child[1]);
	p->child[1] = comp;
	return epi;
}
/*
 * Add a SIMPLE node at the root of t and percolate all the redirections
 * up to the root.
 */

tree*
simplemung(tree *t)
{
	tree *u;
	struct io *s;
	t = tree1(SIMPLE, t);
	s = openstr();
	pfmt(s, "%t", t);
	t->str = strdup((char*)s->strp);
	closeio(s);
	for(u = t->child[0];u->type==ARGLIST;u = u->child[0]){
		if(u->child[1]->type==DUP
		|| u->child[1]->type==REDIR){
			u->child[1]->child[1] = t;
			t = u->child[1];
			u->child[1] = 0;
		}
	}
	return t;
}

tree*
token(char *str, int type)
{
	tree *t = newtree();

	t->type = type;
	t->str = strdup(str);
	return t;
}

void
freetree(tree *p)
{
	if(p==0)
		return;	
	freetree(p->child[0]);
	freetree(p->child[1]);
	freetree(p->child[2]);
	if(p->str)
		efree(p->str);
	efree((char *)p);
}

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