isAfterTyper test

Add test whether we are after typer. Use it to assert that
eta expansion and implicit search do not happen after typer.

3 files changed, 8 insertions, 2 deletions

diff --git a/src/dotty/tools/dotc/core/Phases.scala b/src/dotty/tools/dotc/core/Phases.scala
index f76b83db6..251cd3876 100644
--- a/src/dotty/tools/dotc/core/Phases.scala
+++ b/src/dotty/tools/dotc/core/Phases.scala
@@ -36,6 +36,8 @@ trait Phases {
 
   def atPhaseNotLaterThanTyper[T](op: Context => T): T =
     atPhaseNotLaterThan(base.typerPhase)(op)
+
+  def isAfterTyper: Boolean = base.isAfterTyper(phase)
 }
 
 object Phases {
@@ -177,9 +179,11 @@ object Phases {
     def refchecksPhase = refChecksCache.phase
     def erasurePhase = erasureCache.phase
     def flattenPhase = flattenCache.phase
+
+    def isAfterTyper(phase: Phase): Boolean = phase.id > typerPhase.id
   }
 
-  final val typerName = "typer"
+  final val typerName = "frontend"
   final val refChecksName = "refchecks"
   final val erasureName = "erasure"
   final val flattenName = "flatten"
diff --git a/src/dotty/tools/dotc/typer/EtaExpansion.scala b/src/dotty/tools/dotc/typer/EtaExpansion.scala
index 099dd943a..110dc6152 100644
--- a/src/dotty/tools/dotc/typer/EtaExpansion.scala
+++ b/src/dotty/tools/dotc/typer/EtaExpansion.scala
@@ -116,6 +116,7 @@ object EtaExpansion {
    */
   def etaExpand(tree: Tree, mt: MethodType, xarity: Int)(implicit ctx: Context): untpd.Tree = {
     import untpd._
+    assert(!ctx.isAfterTyper)
     val defs = new mutable.ListBuffer[tpd.Tree]
     val lifted: Tree = TypedSplice(liftApp(defs, tree))
     val paramTypes: List[Tree] =
diff --git a/src/dotty/tools/dotc/typer/Implicits.scala b/src/dotty/tools/dotc/typer/Implicits.scala
index 93876651a..4767e6dd3 100644
--- a/src/dotty/tools/dotc/typer/Implicits.scala
+++ b/src/dotty/tools/dotc/typer/Implicits.scala
@@ -400,6 +400,7 @@ trait Implicits { self: Typer =>
    *  !!! todo: catch potential cycles
    */
   def inferImplicit(pt: Type, argument: Tree, pos: Position)(implicit ctx: Context): SearchResult = track("inferImplicit") {
+    assert(!ctx.isAfterTyper)
     ctx.traceIndented(s"search implicit ${pt.show}, arg = ${argument.show}: ${argument.tpe.show}", implicits, show = true) {
       assert(!pt.isInstanceOf[ExprType])
       val isearch =
@@ -472,7 +473,7 @@ trait Implicits { self: Typer =>
           shadowedImplicit(ref, methPart(shadowing).tpe)
         }
         else
-          SearchSuccess(generated, ref, ctx.typerState)
+          SearchSuccess(generated1, ref, ctx.typerState)
       }}
 
       /** Given a list of implicit references, produce a list of all implicit search successes,