#include "rc.h"#include "y.tab.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;} voidfreenodes(void){	Tree *t, *u;	for(t=Treenodes;t;t=u){		u=t->next;		if(t->str)			free(t->str);		free(t);	}	Treenodes=0;} Tree *tree1(int type, Tree *c0){	return tree3(type, c0, 0, 0);} Tree *tree2(int type, Tree *c0, Tree *c1){	return tree3(type, c0, c1, 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;	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;} voidfreetree(Tree *p){	if(p==0) return;		freetree(p->child[0]);	freetree(p->child[1]);	freetree(p->child[2]);	if(p->str) free(p->str);	free((char *)p);}