Expected warning for @volatile def

[Benjamin Darfler]

Hello all,

I recently came across the following code in our codebase:

@volatile def doSomething = { /** do the thing */ }

I was immediately suspicious and created the following test

class Test {

  @volatile private[this] var something = "something"

  @volatile def doSomething = { println(something) }

}

$ scalac test.scala

$ javap -p Test.class

Compiled from "test.scala"

public class Test {

private volatile java.lang.String something;

public void doSomething();

public Test();

}

As you can see the @volatile on the var translates into a volatile variable in Java but the @volatile on the def is silently dropped. 

This makes sense since a @volatile def is nonsensical but I was surprised that there was no compiler warning for this.

Should this be considered a bug?

Ben Darfler

[Adriaan Moors]

Yes, I agree the compiler should warn more consistently about nonsensical use of @volatile.

I filed this at https://github.com/scala/scala-dev/issues/190