1.1 --- a/src/share/classes/com/sun/tools/javac/code/Types.java Mon Feb 28 11:48:53 2011 +0000
1.2 +++ b/src/share/classes/com/sun/tools/javac/code/Types.java Mon Feb 28 11:50:56 2011 +0000
1.3 @@ -2832,12 +2832,26 @@
1.4 while (ts.head.tag != CLASS && ts.head.tag != TYPEVAR)
1.5 ts = ts.tail;
1.6 Assert.check(!ts.isEmpty());
1.7 - List<Type> cl = closure(ts.head);
1.8 + //step 1 - compute erased candidate set (EC)
1.9 + List<Type> cl = erasedSupertypes(ts.head);
1.10 for (Type t : ts.tail) {
1.11 if (t.tag == CLASS || t.tag == TYPEVAR)
1.12 - cl = intersect(cl, closure(t));
1.13 + cl = intersect(cl, erasedSupertypes(t));
1.14 }
1.15 - return compoundMin(cl);
1.16 + //step 2 - compute minimal erased candidate set (MEC)
1.17 + List<Type> mec = closureMin(cl);
1.18 + //step 3 - for each element G in MEC, compute lci(Inv(G))
1.19 + List<Type> candidates = List.nil();
1.20 + for (Type erasedSupertype : mec) {
1.21 + List<Type> lci = List.of(asSuper(ts.head, erasedSupertype.tsym));
1.22 + for (Type t : ts) {
1.23 + lci = intersect(lci, List.of(asSuper(t, erasedSupertype.tsym)));
1.24 + }
1.25 + candidates = candidates.appendList(lci);
1.26 + }
1.27 + //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
1.28 + //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
1.29 + return compoundMin(candidates);
1.30
1.31 default:
1.32 // calculate lub(A, B[])
1.33 @@ -2851,6 +2865,18 @@
1.34 }
1.35 }
1.36 // where
1.37 + List<Type> erasedSupertypes(Type t) {
1.38 + ListBuffer<Type> buf = lb();
1.39 + for (Type sup : closure(t)) {
1.40 + if (sup.tag == TYPEVAR) {
1.41 + buf.append(sup);
1.42 + } else {
1.43 + buf.append(erasure(sup));
1.44 + }
1.45 + }
1.46 + return buf.toList();
1.47 + }
1.48 +
1.49 private Type arraySuperType = null;
1.50 private Type arraySuperType() {
1.51 // initialized lazily to avoid problems during compiler startup
