1 #include "rc.h"
2 #include "exec.h"
3 #include "io.h"
4 #include "fns.h"
5 tree *treenodes;
6 /*
7  * create and clear a new tree node, and add it
8  * to the node list.
9  */
10 
11 tree*
12 newtree(void)
13 {
14 	tree *t = new(tree);
15 	t->iskw = 0;
16 	t->str = 0;
17 	t->child[0] = t->child[1] = t->child[2] = 0;
18 	t->next = treenodes;
19 	treenodes = t;
20 	return t;
21 }
22 
23 void
24 freenodes(void)
25 {
26 	tree *t, *u;
27 	for(t = treenodes;t;t = u){
28 		u = t->next;
29 		if(t->str)
30 			efree(t->str);
31 		efree((char *)t);
32 	}
33 	treenodes = 0;
34 }
35 
36 tree*
37 tree1(int type, tree *c0)
38 {
39 	return tree3(type, c0, (tree *)0, (tree *)0);
40 }
41 
42 tree*
43 tree2(int type, tree *c0, tree *c1)
44 {
45 	return tree3(type, c0, c1, (tree *)0);
46 }
47 
48 tree*
49 tree3(int type, tree *c0, tree *c1, tree *c2)
50 {
51 	tree *t;
52 	if(type==';'){
53 		if(c0==0)
54 			return c1;
55 		if(c1==0)
56 			return c0;
57 	}
58 	t = newtree();
59 	t->type = type;
60 	t->child[0] = c0;
61 	t->child[1] = c1;
62 	t->child[2] = c2;
63 	return t;
64 }
65 
66 tree*
67 mung1(tree *t, tree *c0)
68 {
69 	t->child[0] = c0;
70 	return t;
71 }
72 
73 tree*
74 mung2(tree *t, tree *c0, tree *c1)
75 {
76 	t->child[0] = c0;
77 	t->child[1] = c1;
78 	return t;
79 }
80 
81 tree*
82 mung3(tree *t, tree *c0, tree *c1, tree *c2)
83 {
84 	t->child[0] = c0;
85 	t->child[1] = c1;
86 	t->child[2] = c2;
87 	return t;
88 }
89 
90 tree*
91 epimung(tree *comp, tree *epi)
92 {
93 	tree *p;
94 	if(epi==0)
95 		return comp;
96 	for(p = epi;p->child[1];p = p->child[1]);
97 	p->child[1] = comp;
98 	return epi;
99 }
100 /*
101  * Add a SIMPLE node at the root of t and percolate all the redirections
102  * up to the root.
103  */
104 
105 tree*
106 simplemung(tree *t)
107 {
108 	tree *u;
109 	struct io *s;
110 	t = tree1(SIMPLE, t);
111 	s = openstr();
112 	pfmt(s, "%t", t);
113 	t->str = strdup(s->strp);
114 	closeio(s);
115 	for(u = t->child[0];u->type==ARGLIST;u = u->child[0]){
116 		if(u->child[1]->type==DUP
117 		|| u->child[1]->type==REDIR){
118 			u->child[1]->child[1] = t;
119 			t = u->child[1];
120 			u->child[1] = 0;
121 		}
122 	}
123 	return t;
124 }
125 
126 tree*
127 token(char *str, int type)
128 {
129 	tree *t = newtree();
130 	t->type = type;
131 	t->str = strdup(str);
132 	return t;
133 }
134 
135 void
136 freetree(tree *p)
137 {
138 	if(p==0)
139 		return;	
140 	freetree(p->child[0]);
141 	freetree(p->child[1]);
142 	freetree(p->child[2]);
143 	if(p->str)
144 		efree(p->str);
145 	efree((char *)p);
146 }