int
epcmp( /* compare two expressions for equivalence */
EPNODE *ep1,
EPNODE *ep2
)
{
double d;
if (ep1->type != ep2->type)
return(1);
switch (ep1->type) {
case VAR:
return(ep1->v.ln != ep2->v.ln);
case NUM:
if (ep2->v.num == 0)
return(ep1->v.num != 0);
d = ep1->v.num / ep2->v.num;
return((d > 1.000000000001) | (d < 0.999999999999));
case CHAN:
case ARG:
return(ep1->v.chan != ep2->v.chan);
case '=':
case ':':
return(epcmp(ep1->v.kid->sibling, ep2->v.kid->sibling));
case CLKT:
case SYM: /* should never get this one */
return(0);
default:
ep1 = ep1->v.kid;
ep2 = ep2->v.kid;
while (ep1 != NULL) {
if (ep2 == NULL)
return(1);
if (epcmp(ep1, ep2))
return(1);
ep1 = ep1->sibling;
ep2 = ep2->sibling;
}
return(ep2 != NULL);
}
}
void
getstatement(void) /* get next statement */
{
EPNODE *ep;
char *qname;
VARDEF *vdef;
if (nextc == ';') { /* empty statement */
scan();
return;
}
if (esupport&E_OUTCHAN &&
nextc == '$') { /* channel assignment */
ep = getchan();
addchan(ep);
} else { /* ordinary definition */
ep = getdefn();
qname = qualname(dname(ep), 0);
if (esupport&E_REDEFW && (vdef = varlookup(qname)) != NULL) {
if (vdef->def != NULL && epcmp(ep, vdef->def)) {
wputs(qname);
if (vdef->def->type == ':')
wputs(": redefined constant expression\n");
else
wputs(": redefined\n");
} else if (ep->v.kid->type == FUNC && vdef->lib != NULL) {
wputs(qname);
wputs(": definition hides library function\n");
}
}
if (ep->type == ':')
dremove(qname);
else
dclear(qname);
dpush(qname, ep);
}
if (nextc != EOF) {
if (nextc != ';')
syntax("';' expected");
scan();
}
}
