Node *makearr(Node *p)
{
Cell *cp;
if (isvalue(p)) {
cp = (Cell *) (p->narg[0]);
if (isfcn(cp))
SYNTAX( "%s is a function, not an array", cp->nval );
else if (!isarr(cp)) {
xfree(cp->sval);
cp->sval = (char *) makesymtab(NSYMTAB);
cp->tval = ARR;
}
}
return p;
}
Cell *call(Node **a, int n) /* function call. very kludgy and fragile */
{
static Cell newcopycell = { OCELL, CCOPY, 0, "", 0.0, NUM|STR|DONTFREE };
int i, ncall, ndef;
int freed = 0; /* handles potential double freeing when fcn & param share a tempcell */
Node *x;
Cell *args[NARGS], *oargs[NARGS]; /* BUG: fixed size arrays */
Cell *y, *z, *fcn;
char *s;
fcn = execute(a[0]); /* the function itself */
s = fcn->nval;
if (!isfcn(fcn))
FATAL("calling undefined function %s", s);
if (frame == NULL) {
fp = frame = (struct Frame *) calloc(nframe += 100, sizeof(struct Frame));
if (frame == NULL)
FATAL("out of space for stack frames calling %s", s);
}
for (ncall = 0, x = a[1]; x != NULL; x = x->nnext) /* args in call */
ncall++;
ndef = (int) fcn->fval; /* args in defn */
dprintf( ("calling %s, %d args (%d in defn), fp=%d\n", s, ncall, ndef, (int) (fp-frame)) );
if (ncall > ndef)
WARNING("function %s called with %d args, uses only %d",
s, ncall, ndef);
if (ncall + ndef > NARGS)
FATAL("function %s has %d arguments, limit %d", s, ncall+ndef, NARGS);
for (i = 0, x = a[1]; x != NULL; i++, x = x->nnext) { /* get call args */
dprintf( ("evaluate args[%d], fp=%d:\n", i, (int) (fp-frame)) );
y = execute(x);
oargs[i] = y;
dprintf( ("args[%d]: %s %f <%s>, t=%o\n",
i, NN(y->nval), y->fval, isarr(y) ? "(array)" : NN(y->sval), y->tval) );
if (isfcn(y))
FATAL("can't use function %s as argument in %s", y->nval, s);
if (isarr(y))
args[i] = y; /* arrays by ref */
else
args[i] = copycell(y);
tempfree(y);
}
for ( ; i < ndef; i++) { /* add null args for ones not provided */
args[i] = gettemp();
*args[i] = newcopycell;
}
fp++; /* now ok to up frame */
if (fp >= frame + nframe) {
int dfp = fp - frame; /* old index */
frame = (struct Frame *)
realloc((char *) frame, (nframe += 100) * sizeof(struct Frame));
if (frame == NULL)
FATAL("out of space for stack frames in %s", s);
fp = frame + dfp;
}
fp->fcncell = fcn;
fp->args = args;
fp->nargs = ndef; /* number defined with (excess are locals) */
fp->retval = gettemp();
dprintf( ("start exec of %s, fp=%d\n", s, (int) (fp-frame)) );
y = execute((Node *)(fcn->sval)); /* execute body */
dprintf( ("finished exec of %s, fp=%d\n", s, (int) (fp-frame)) );
for (i = 0; i < ndef; i++) {
Cell *t = fp->args[i];
if (isarr(t)) {
if (t->csub == CCOPY) {
if (i >= ncall) {
freesymtab(t);
t->csub = CTEMP;
tempfree(t);
} else {
oargs[i]->tval = t->tval;
oargs[i]->tval &= ~(STR|NUM|DONTFREE);
oargs[i]->sval = t->sval;
tempfree(t);
}
}
} else if (t != y) { /* kludge to prevent freeing twice */
t->csub = CTEMP;
tempfree(t);
} else if (t == y && t->csub == CCOPY) {
t->csub = CTEMP;
tempfree(t);
freed = 1;
}
}
tempfree(fcn);
if (isexit(y) || isnext(y))
return y;
if (freed == 0) {
tempfree(y); /* don't free twice! */
}
z = fp->retval; /* return value */
dprintf( ("%s returns %g |%s| %o\n", s, getfval(z), getsval(z), z->tval) );
fp--;
return(z);
}
