RFR: 8178701: Compile error with switch statement on protected enum defined in parent inner class

[Jan Lahoda]

Consider the following code in two packages:

package foo;

import bar.D.E;

public class A {

    public static class B {

        protected enum C {
            X, Y, Z
        }
    }

    public static void main(String... args) {
        new E().run(B.C.X);
    }
}



package bar;

import foo.A.B;

public class D {

    public static class E extends B {

        public void run(C arg) {
            switch (arg) {
                default:
                    System.out.println("OK");
            }
        }
    }
}


Accessing `foo.A.B.C` in `bar.D.E` is OK, as it is accessible through the `E`'s superclass. But, for the `switch`, javac creates a map (array) from runtime ordinals of constants of `E` to compile-time positions. But, this mapping is in a different class that does not extend `B`, so internal method lookups fail for it, as the methods are not accessible per Java rules.

But, at runtime, the enum class is effectively public, so I think it is possible to ignore the protected access rules and accept the method invocations while generatting the mapping code, which is what this patch is trying to do.

-------------

Commit messages:
 - 8178701: Compile error with switch statement on protected enum defined in parent inner class

Changes: https://git.openjdk.java.net/jdk/pull/7621/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7621&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8178701
  Stats: 184 lines in 4 files changed: 137 ins; 0 del; 47 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7621.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7621/head:pull/7621

PR: https://git.openjdk.java.net/jdk/pull/7621