Fix scala#19369 - duplicate macro execution in unapply methods

Author: jchyb

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -1446,7 +1446,7 @@ trait Applications extends Compatibility {
             unapplyArgType
 
         val dummyArg = dummyTreeOfType(ownType)
-        val unapplyApp = typedExpr(untpd.TypedSplice(Apply(unapplyFn, dummyArg :: Nil)))
+        val unapplyApp = typedExpr(untpd.TypedSplice(Apply(unapplyFn, dummyArg :: Nil)))(using ctx.addMode(Mode.NoInline))
         def unapplyImplicits(unapp: Tree): List[Tree] = {
           val res = List.newBuilder[Tree]
           def loop(unapp: Tree): Unit = unapp match {

tests/pos-macros/i19369/Macro_1.scala

@@ -0,0 +1,11 @@
+import scala.quoted._
+
+object Unapplier:
+  transparent inline def unapply(arg: Any): Option[Int] = ${unapplyImpl('arg)}
+
+  def unapplyImpl(using Quotes)(argExpr: Expr[Any]): Expr[Option[Int]] =
+    import quotes.reflect._
+    // The code below will recurse, throwing cyclic reference, if it is being inlined too early,
+    // which is caused by the same problem as the duplicate macro execution here
+    println(Symbol.spliceOwner.owner.tree)
+    '{Some(1)}

tests/pos-macros/i19369/Main_2.scala

@@ -0,0 +1,5 @@
+object Test {
+  def main(args: Array[String]): Unit = {
+    val Unapplier(result) = Some(5)
+  }
+}