jehanne/sys/src/cmd/rc/tree.c

171 lines
2.8 KiB
C

/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
/* Portions of this file are Copyright (C) 9front's team.
* See /doc/license/9front-mit for details about the licensing.
* See http://git.9front.org/plan9front/plan9front/HEAD/info.html for a list of authors.
*/
#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;
t->line = runq->lexline;
treenodes = t;
return t;
}
void
freenodes(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, (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*
treeeq(tree *c0, tree *c2)
{
tree *c1 = token("=", WORD);
return tree2('^', tree2('^', c0, c1), c2);
}
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 = estrdup((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)
free(p->str);
free(p);
}