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cpython/Parser/node.c
1990-12-20 15:06:42 +00:00

77 lines
1.2 KiB
C

/* Parse tree node implementation */
#include "pgenheaders.h"
#include "node.h"
node *
newtree(type)
int type;
{
node *n = NEW(node, 1);
if (n == NULL)
return NULL;
n->n_type = type;
n->n_str = NULL;
n->n_lineno = 0;
n->n_nchildren = 0;
n->n_child = NULL;
return n;
}
#define XXX 3 /* Node alignment factor to speed up realloc */
#define XXXROUNDUP(n) ((n) == 1 ? 1 : ((n) + XXX - 1) / XXX * XXX)
node *
addchild(n1, type, str, lineno)
register node *n1;
int type;
char *str;
int lineno;
{
register int nch = n1->n_nchildren;
register int nch1 = nch+1;
register node *n;
if (XXXROUNDUP(nch) < nch1) {
n = n1->n_child;
nch1 = XXXROUNDUP(nch1);
RESIZE(n, node, nch1);
if (n == NULL)
return NULL;
n1->n_child = n;
}
n = &n1->n_child[n1->n_nchildren++];
n->n_type = type;
n->n_str = str;
n->n_lineno = lineno;
n->n_nchildren = 0;
n->n_child = NULL;
return n;
}
/* Forward */
static void freechildren PROTO((node *));
void
freetree(n)
node *n;
{
if (n != NULL) {
freechildren(n);
DEL(n);
}
}
static void
freechildren(n)
node *n;
{
int i;
for (i = NCH(n); --i >= 0; )
freechildren(CHILD(n, i));
if (n->n_child != NULL)
DEL(n->n_child);
if (STR(n) != NULL)
DEL(STR(n));
}