Parent of primitive arrays is not Object[]

[GraxCode]

CFR version

499f6d3b2e431bc647e1f4c1799ec178c8e9e600

Compiler

jdk 8

Description

CFR assumes the parent type of primitive arrays is Object[]. This code is invalid.

    public static void main(String[] args) {
        Object[] array = null;
        array = byteArray ? new byte[1] : new boolean[1];
        array[0] = 0;
        System.out.println(array[0]);
    }

it should be

   public static void main(String[] args) {
      Object array = null;
      array = byteArray ? new byte[1] : new boolean[1];
      ((byte[])array)[0] = 0;
      System.out.println(((byte[])array)[0]);
   }

It is also important to not ignore the cast on the bastore instruction as bastore works for byte[] and boolean[]. (I tried to make a sample that is not decompilable, but found this bug instead. And it seems like java requires a checkcast before the array store, so my idea is not really possible).

Example

ByteBooleanDesaster.class.txt

[Marcono1234]

Might be related to #132.

---

I tried to make a sample that is not decompilable, but found this bug instead. And it seems like java requires a checkcast before the array store, so my idea is not really possible

It would probably be good if CFR then emitted a comment noting that the array cast is a behavior change.

[GraxCode]

It would probably be good if CFR then emitted a comment noting that the array cast is a behavior change.

I meant java needs the checkcast, as the verifier would throw an error. I didn't know that and tried to make a bastore that takes either a byte or boolean array. This does not work. Also the cast would have to be placed in decompiled code either way, as the array reference is an Object, so no behavior change. So, if the array reference is not an Object, but a byte[], the cast is not needed.

[leibnitz27]

All of these things boil down to inadequate lifetime analysis. I'm going to have a go at improving that over the next month or so - but it's a big job which requires lots of surgery, so I wouldn't expect much for a while.