Classification makeClassification(ConstMap cm, MustParamOracle mpo, HCodeElement hce, Temp t) {
if (cm.isConst(hce, t)) // constant value?
return new Classification(cm.constMap(hce, t));
if (mpo.isMustParam(t)) // must be a parameter?
return new Classification(mpo.whichMustParam(t));
return new Classification(); // no info
}
/** Find fields which are *not* subclass-final. */
private Set findBadFields(HCodeFactory hcf, ClassHierarchy ch) {
Set badFields = new HashSet();
// for each callable method...
for (Iterator it = ch.callableMethods().iterator(); it.hasNext(); ) {
HMethod hm = (HMethod) it.next();
HCode hc = hcf.convert(hm);
if (hc == null) continue; // xxx: native methods may write fields!
// construct a must-param oracle for constructors.
MustParamOracle mpo = isConstructor(hm) ? new MustParamOracle(hc) : null;
// examine this method for writes
HClass thisClass = hc.getMethod().getDeclaringClass();
for (Iterator it2 = hc.getElementsI(); it2.hasNext(); ) {
Quad q = (Quad) it2.next();
if (q instanceof SET) {
SET qq = (SET) q;
// ignore writes of static fields.
if (qq.isStatic()) continue;
// if this is a constructor, than it may write only
// to fields of 'this'
if (isConstructor(hm)
&& mpo.isMustParam(qq.objectref())
&& mpo.whichMustParam(qq.objectref()) == 0) continue; // this is a permitted write.
// writes by subclass methods to superclass fields are
// okay. (but not writes by 'this' methods to 'this'
// fields, unless the method is a constructor)
if (qq.field().getDeclaringClass().isInstanceOf(thisClass)
&&
// XXX i think the presence of the 'isConstructor'
// clause here is a bug. constructor writes
// should be taken care of by clause above.
(isConstructor(hm) || !thisClass.equals(qq.field().getDeclaringClass())))
continue; // subclass writes are permitted.
// non-permitted write!
badFields.add(qq.field());
}
}
// on to the next!
}
// done! we have set of all bad (not subclass-final) fields.
return Collections.unmodifiableSet(badFields);
}
