Inconsistent lifting of receiver in macro

[allanrenucci]

Let's consider the following macro:

import scala.quoted._
import scala.tasty.Tasty

object Macro {
  class StringContextOps(sc: => StringContext) {
    rewrite def ff(args: => Any*): String = ~Macro.impl('(sc), '(args))
  }
  implicit rewrite def XmlQuote(sc: => StringContext): StringContextOps = new StringContextOps(sc)
  def impl(sc: Expr[StringContext], args: Expr[Seq[Any]])(implicit tasty: Tasty): Expr[String] = {
    import tasty._

    println(sc.toTasty.show)
    println(args.toTasty.show)
    '("")
  }
}

In the following use case:

class Test {
  import Macro._
  def test = ff"Hello World ${1}!"
}

the Macro.impl sees the receiver sc as

Macro.impl(
  scala.quoted.Expr.apply[StringContext](
    {
      _root_.scala.StringContext.apply(
        ["Hello World ","!" : String]: String*
      )
    }
  ),
  scala.quoted.Expr.apply[Any*](
    {
      [1 : Any]: Any*
    }
  )
)

as expected.

But now if my interpolator has no splice:

class Test {
  import Macro._
  def test = ff"Hello World"
}

the receiver is lifted out and I only see a reference to it:

val $1$: Macro.StringContextOps = ...

Macro.impl(
  scala.quoted.Expr.apply[StringContext](
    {
      $1$
    }.inline$sc
  ),
  scala.quoted.Expr.apply[Any*](
    {
      [ : Any]: Any*
    }
  )
)

[allanrenucci]

Blocked on this for xml interpolation

[nicolasstucki]

This can be minimized to

object Macro {
  final class StringContextOps(sc: => StringContext) {
    rewrite def ff(args: => Any*): String = sc.toString
  }
  implicit rewrite def XmlQuote(sc: => StringContext): StringContextOps = new StringContextOps(sc)

  def test0 = ff"Hello World 0!"
  def test1 = ff"Hello World 1 ${1}!"
  def test2 = ff"Hello World 2 ${22} ${222}!"
}

where in test0 sc is not inlined.

[allanrenucci]

Note that this is still an issue after the introduction of TermAPI::underlyingArgument

[allanrenucci]

So this is not as issue with Inlining but when typing StringContext("Hello").foo():

object Test {
  implicit class SCOps(ctx: StringContext) {
    def foo(args: => Any*): String = ""
  }

  def test(name: String) = {
    // {
    //   val $1$: Test.SCOps = SCOps(StringContext.apply(["Hello" : String]: String*))
    //   $1$.foo([ : Any]: Any*)
    // }
    foo"Hello"

    // SCOps(StringContext.apply(["Hello ","" : String]: String*)).foo([name : Any]: Any*)
    foo"Hello $name"
  }
}