@GuardedBy checks inconsistent: variables vs methods, 'this' qualifier, etc.

[goldberg-n]

(2.1.3)

I noticed a bunch of weirdness with @GuardedBy: mostly it works as expected, but in quite a few cases that Error Prone should complain, it doesn't.

Altering this test slightly:

class Test {
    final Object mu = new Object();
    @GuardedBy("mu") int y;
    @GuardedBy("mu") void y() {}
}

class Main {
    void m(Test t) {
        t.y++; // Barfs, as expected
        t.y(); // No complaints
    }
}

Some more oddities:

class Main {
    void m(Test t) {
        // ErrorProne complains, as expected
        thisLock();
        t.classLock();

        // ErrorProne is fine with these?
        this.thisLock();
        t.testLock();
    }

    @GuardedBy("this") void thisLock() {}
}
 
class Test {
    @GuardedBy("Test.class") void classLock () {}
    @GuardedBy("this") void testLock() {}
}