[2.13.9] Whitebox macro sometimes not return right side macro expansion type with -Xsource:3

[jilen]

Reproduction steps

Scala version: 2.13.9

For quill's quote method (whitebox macro)

implicit def quote[T](body: T): Quoted[T] = macro QuotationMacro.quote[T]

With following example

//> using lib "io.getquill::quill-core:4.4.1"
//> using option "-Xsource:3"

import io.getquill._

case class TestEntity(name: String)
object Foo {
  val ctx = new MirrorContext(MirrorIdiom, Literal)
  import ctx._
  val q1 = quote(query[TestEntity])
}

Foo.q1 is inferred as io.getquill.Quoted[io.getquill.EntityQuery[TestEntity]]

Problem

Foo.q1 should be the anonymous class type

Note

//> using lib "org.scala-lang:scala-reflect:2.13.9"
//> using option "-Xsource:3"

import scala.language.experimental.macros
import scala.reflect.macros.whitebox.Context

trait Ast
case class Foo(id: Int) extends Ast

trait Ctx {
  trait Quoted[+A] {
    def ast: Ast
    def data: A
  }
  final def quote[A](a: A): Quoted[A] = macro QuoteMacro.quoteImpl[A]
}


class QuoteMacro(val c: Context) {

  import c.universe._

  def quoteImpl[A](a: c.Expr[A])(implicit ta: WeakTypeTag[A]) = {
    val m = TermName(c.freshName("fff"))
    val tree = c.untypecheck {
      q"""
      new ${c.prefix}.Quoted[$ta] {
         def $m() = ()
         def data = $a
         final override def ast: Foo = Foo(0)
      }
      """
    }
    println(tree)
    tree
  }
}

object Foo {
  val ctx = new Ctx {}
}

Tried this example, but Foo.ctx.quote works just fine.

Maybe related to scala/scala#9891

[som-snytt]

That is a good question.

[som-snytt]

Just realized that the code is not a minimization, and "works just fine" is not a typo.

[som-snytt]

I verified that it's sufficient to check for macros in flight before using the Xsource:3 behavior.

I'll try to make a test that fails.

I could not figure out how to make scala-cli give me -Vprint output, so I made a small sbt project. It will be a while before I touch scala-cli again.