Add access information to SymbolInformation

[tanishiking]

#12963

This PR adds access information to SymbolInformation. I confirm the diff is legit just by thoroughly check the diff in metac.expect.

(but, it might be better to have a script to verify the Scala2 and Scala3 will extract the same SemanticDB for the same program, so we can use the scala2's output as a test oracle 🤔 )(as long as the program compiles both in Scala2 and Scala3)

[bishabosha]

Thank you for taking this on!
There seems to be an issue with private-qualified/protected-qualified that does not match my expectation

[bishabosha]

worth noting here that the official metap will print the displayName of the associated SymbolInformation, and we have been trying to replicate its output style as much as possible

[tanishiking]

Yeah, the situation will be better with #12885 but I was just a bit lazy to duplicate the pretty printer to this PR... Can I go with this and prettify it in the future?

[bishabosha]

yep, this is fine for now

[bishabosha]

Here I think printing info.access should come before printing info.kind (private[example] val method foo rather than val method private[example] foo)

[tanishiking]

done 338e6d2

[bishabosha]

if we look in tests/semanticdb/expect/Access.scala this should be private qualified not protected qualified

[tanishiking]

Fixed by #12964 (comment)

[bishabosha]

I think here that a private qualified symbol never gets the private flag, you should instead check if it is protected. See the other comment about the metac.expect output for tests/semanticdb/expect/Access.scala

[tanishiking]

You're right, fixed in fb6b679 👍

[bishabosha]

I'm not sure this is right, in scala 2 semanticdb the access is printed as private, and the definition in tests/semanticdb/expect/semanticdb-Flags.scala is private lazy val x = 1

[bishabosha]

to debug you can try using this script I made.

If I run it with

scala3-compiler-bootstrapped/Test/runMain dotty.tools.printSymFlags "package flags { package object p { private lazy val x = 1 }}" "x"

I get the output

val x => lazy <touched> private[module class p]

// compiler/test/dotty/tools/DottySymbolStealer.scala
package dotty.tools

import dotc.ast.tpd
import dotc.core.Names._
import dotc.ast.tpd._
import dotc.core.Contexts.Context
import dotc.core.Symbols.Symbol
import dotc.core.Decorators._
import dotc.core.Types.Type

@main def printSymFlags(source: String, termRefs: String*) = {
  val (ctx, syms) = DottySymbolStealer.stealSymbol(source, termRefs*)
  given Context = ctx
  syms.map(sym =>
    val priv = sym.privateWithin
    s"$sym => ${sym.flags.flagStrings(if priv.exists then s"$priv" else "").mkString(" ")}"
  ).foreach(println)
}

object DottySymbolStealer extends DottyTest {
  def stealSymbol(source: String, termRefs: String*): (Context, List[Symbol]) = {
    var scontext : Context = null
    var tp: List[Symbol] = null
    checkCompile("typer", source) {
      (tree, context) =>
        given Context = context
        val remaining = scala.collection.mutable.Set.from(termRefs)
        val findDef: (List[ValOrDefDef], tpd.Tree) => List[ValOrDefDef] =
          (acc , tree) =>  tree match {
            case t: ValOrDefDef =>
              remaining.find(t.name.toString == _) match
                case Some(name) =>
                  remaining -= name
                  t :: acc
                case _ =>
                  acc
            case _ => acc
          }
        val d = new DeepFolder[List[ValOrDefDef]](findDef).foldOver(Nil, tree)
        tp = d.map(_.symbol).reverse
        scontext = context
    }
    (scontext, tp)
  }
}

[bishabosha]

so using scala 2 repl with the power mode it appears that private values in a package object do not get a privateWithin symbol, but I think its ok to keep it for scala 3, however it still needs to be private[p] not protected[p]

[bishabosha]

This looks great to me, thank you