Populate addresses of symbols, types and trees after pickler

[DarkDimius]

To allow other phases to generate additional sections that refer to them.

[DarkDimius]

@odersky please review

[odersky]

I'd use a simple loop here:

for ((key, addr) <- mp.toList) mp(key) = adjusted(addr)

Shorter, clearer, faster.

[retronym]

Updating a mutable data structure during iteration doesn't work in general. I guess this is safe because you don't change the key set, but I would be cautious about using the same approach in general.

If you were to use an mutable.AnyRefMap rather than a mutable.Map (which is a good idea for performance reasons anyway), you can use mp.transformValues(adjusted).

[DarkDimius]

That's way I wrote the code this way: at the point when I am updating the datastructure, I'm already iterating over a different one.

[odersky]

@retronym: Good point. We could modify like this

for (key <- mp.keysIterator.toBuffer) mp(key) = adjusted(mp(key))

That looks like the most efficient safe solution. I believe efficiency is a concern here - these maps can become large.

[retronym]

Any reason to avoid AnyRefMap? IMO that should be the first choice when you need a map in the compiler. Its main claim to fame is that it can calls equals/hashCode rather than ==/``##` which is a non-negligible performance win.

[odersky]

Otherwise, LGTM