#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;}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(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);}