Should we include synthetic fields?

[algomaster99]

Hi @khaes-kth,

You posted this diff on overleaf reporting that it is no longer reproducible. This happens because we exclude synthetic fields. The compiler creates an implicit this$0 reference to the outerclass of TreeNode, but we ignore it. If we include it, we get the same output as before.

[algomaster99]

Consider this case:

package synthetic;

public class SyntheticField {
    int x;
    int y;

    public class InnerClass {
        int z;

        public InnerClass() {
            z = 42;
        }

        public int getZ() {
            return z; // breakpoint
        }
    }
}

Trace excluding synthetic fields

{
  "breakpoint" : [
    {
      "file" : "synthetic/SyntheticField$InnerClass",
      "lineNumber" : 15,
      "stackFrameContext" : [
        {
          "positionFromTopInStackTrace" : 1,
          "location" : "synthetic.SyntheticField$InnerClass:15",
          "stackTrace" : [
            "getZ:15, synthetic.SyntheticField$InnerClass",
            "fieldTest:9, FieldTest"
          ],
          "runtimeValueCollection" : [
            {
              "kind" : "FIELD",
              "name" : "z",
              "type" : "int",
              "fields" : [ ],
              "value" : 42,
              "arrayElements" : [ ]
            }
          ]
        }
      ]
    }
  ],
  "return" : [ ]
}

Trace including synthetic fields

{
  "breakpoint" : [
    {
      "file" : "synthetic/SyntheticField$InnerClass",
      "lineNumber" : 15,
      "stackFrameContext" : [
        {
          "positionFromTopInStackTrace" : 1,
          "location" : "synthetic.SyntheticField$InnerClass:15",
          "stackTrace" : [
            "getZ:15, synthetic.SyntheticField$InnerClass",
            "fieldTest:9, FieldTest"
          ],
          "runtimeValueCollection" : [
            {
              "kind" : "FIELD",
              "name" : "z",
              "type" : "int",
              "fields" : [ ],
              "value" : 42,
              "arrayElements" : [ ]
            },
            {
              "kind" : "FIELD",
              "name" : "this$0",
              "type" : "synthetic.SyntheticField",
              "fields" : [
                {
                  "kind" : "FIELD",
                  "name" : "x",
                  "type" : "int",
                  "fields" : [ ],
                  "value" : 0,
                  "arrayElements" : [ ]
                },
                {
                  "kind" : "FIELD",
                  "name" : "y",
                  "type" : "int",
                  "fields" : [ ],
                  "value" : 0,
                  "arrayElements" : [ ]
                }
              ],
              "value" : "synthetic.SyntheticField",
              "arrayElements" : [ ]
            }
          ]
        }
      ]
    }
  ],
  "return" : [ ]
}

[khaes-kth]

Great! I believe we should ignore such synthetic fields. So, I'm closing this discussion.