Only strip synthetic ascriptions inside inlined defs

Author: mbovel

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -836,6 +836,8 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
     unsplice(tree) match
       case Typed(expr, _) if tree.span.isSynthetic =>
         stripSyntheticTyped(expr)
+      case tree @ Inlined(call, bindings, expr) =>
+        cpy.Inlined(tree)(call, bindings, stripSyntheticTyped(expr))
       case Block(stats, expr) =>
         cpy.Block(tree)(stats, stripSyntheticTyped(expr))
       case _ =>

compiler/src/dotty/tools/dotc/inlines/Inliner.scala

@@ -790,7 +790,7 @@ class Inliner(val call: tpd.Tree)(using Context):
       }
 
       // Run a typing pass over the inlined tree. See InlineTyper for details.
-      val expansion1 = inlineTyper.typed(stripSyntheticTyped(expansion))(using inlineCtx)
+      val expansion1 = inlineTyper.typed(expansion)(using inlineCtx)
 
       if (ctx.settings.verbose.value) {
         inlining.println(i"to inline = $rhsToInline")
@@ -1056,7 +1056,8 @@ class Inliner(val call: tpd.Tree)(using Context):
       val meth = tree.symbol
       if meth.isAllOf(DeferredInline) then
         errorTree(tree, em"Deferred inline ${meth.showLocated} cannot be invoked")
-      else if Inlines.needsInlining(tree) then Inlines.inlineCall(simplify(tree, pt, locked))
+      else if Inlines.needsInlining(tree) then
+        stripSyntheticTyped(Inlines.inlineCall(simplify(tree, pt, locked)))
       else tree
 
     override def typedUnadapted(tree: untpd.Tree, pt: Type, locked: TypeVars)(using Context): Tree =

tests/run/i24420-inline-local-ref.check

@@ -9,4 +9,4 @@ inline def h(): Long =
   inline if g() > 0L then 1L else 0L
 
 @main def Test: Unit =
-  println(h())
+  assert(h() == 1L)

tests/run/i24420-inline-local-ref.scala

@@ -9,4 +9,4 @@ transparent inline def h(): Long =
   inline if g() > 0L then 1L else 0L
 
 @main def Test: Unit =
-  println(h())
+  assert(h() == 1L)