Merge pull request #11029 from dotty-staging/fix-#9254

Add regression test

Author: nicolasstucki

tests/pos-macros/i9254/Macros_1.scala

@@ -0,0 +1,59 @@
+package cps
+
+import scala.quoted._
+
+trait CpsMonad[F[_]]
+
+trait ComputationBound[T]
+
+implicit object ComputationBoundMonad extends CpsMonad[ComputationBound]
+
+inline def async[F[_]](using am:CpsMonad[F]): Async.InferAsyncArg[F] =
+   new Async.InferAsyncArg[F]
+
+object PFHelper {
+  def create[X,Y](x:Boolean):PartialFunction[X,Y] = ???
+}
+
+object Async {
+
+  class InferAsyncArg[F[_]](using am:CpsMonad[F]) {
+
+       inline def apply[T](inline expr: T):Unit =
+       ${
+         Async.transformImpl[F,T]('expr)
+        }
+
+  }
+
+  def transformImpl[F[_]:Type,T:Type](f: Expr[T])(using Quotes): Expr[Unit] =
+    import quotes.reflect._
+
+    def uninline(t:Term):Term =
+      t match
+        case Inlined(_,_,x) => uninline(x)
+        case _ => t
+
+    val fu = uninline(f.asTerm)
+    fu match
+      case Block(_,Apply(TypeApply(Select(q,n),tparams),List(param))) =>
+        param.tpe match
+          case AppliedType(tp,tparams1) =>
+            val fromTypeOrBounds = tparams1.head
+            val fromType = fromTypeOrBounds match
+                 case bounds: TypeBounds => bounds.low
+                 case tp: TypeRepr => tp
+                 case np: NoPrefix => ???
+            val toType = tparams1.tail.head
+            val fType = TypeRepr.of[F]
+            val toWrapped = fType.appliedTo(toType)
+            val helper = '{ cps.PFHelper }.asTerm
+            val helperSelect = Select.unique(helper,"create")
+            val createPF = Apply(
+                             TypeApply(helperSelect,List(Inferred(fromType),Inferred(toWrapped))),
+                             List(Literal(BooleanConstant(true)))
+                           )
+            val createPfApply = Apply(Select.unique(createPF,"apply"),List(Literal(IntConstant(1))))
+            Block(List(createPfApply),Literal(UnitConstant())).asExpr.asInstanceOf[Expr[Unit]]
+
+}

tests/pos-macros/i9254/Test_2.scala

@@ -0,0 +1,5 @@
+package cps
+
+val c = async[ComputationBound]{
+    List(1,2,3,4).collectFirst{ case x if x > 0 => x > 3 }
+}