Unexpected tree could not be interpreted

[allanrenucci]

// Foo.scala
import scala.quoted._

class Foo {
  rewrite def foo1: String = ~Foo.impl
}

object Foo {
  rewrite def foo2: String = ~Foo.impl
  private def impl: Expr[String] = '("")
}

// Test.scala
class Test {
  def test1: String = (new Foo).foo1 // error
  def test2: String = Foo.foo2       // ok
}

> dotc -d out Foo.scala
> dotc -classpath out Test.scala
-- Error: Test.scala:2:22 ---------------------------------
2 |  def test1: String = (new Foo).foo1
  |                      ^
  |                      Unexpected tree could not be interpreted: Select(Ident(Foo_this),inline$impl)

If def impl is not private, the code compiles

[odersky]

That's because of the inline accessor. We either need to "see through" such accessors or forbid them (but then a better error message would help).

[allanrenucci]

But why can't we "see through" in the macro foo1 but we do in the macro foo2?

[nicolasstucki]

The issue is that we are generating the accessor a private member of the object in the class.

If we have the following code

class Foo {
  rewrite def foo0: String = Foo.impl1
}

object Foo {
  rewrite def foo1: String = Foo.impl1
  rewrite def foo2: String = Foo.impl2

  private def impl1: String = ""
  private def impl2: String = ""
}

after typer we currently have

result of Foo.scala after frontend:
package <empty> {
  class Foo() extends Object() { 
    rewrite def foo0: String = Foo.impl1
    def inline$impl1: String = Foo.impl1
  }
  final lazy module val Foo: Foo$ = new Foo$()
  final module class Foo$() extends Object() { this: Foo.type => 
    rewrite def foo1: String = Foo.impl1
    rewrite def foo2: String = Foo.impl2
    private def impl1: String = ""
    private def impl2: String = ""
    def inline$impl1: String = Foo.impl1
    def inline$impl2: String = Foo.impl2
  }
}

Note that we generated one inline$impl1 for foo0 in class Foo and one for foo1 in object Foo. Instead we should only generate inline$impl1 in object Foo and use that one for foo0.

[biboudis]

Check if still occurs after #5138 is merged.