SI-8375 saner binary incompat errors for macros

Inspired by Brian McKenna's RC1 migration experience, this commit improves
macro impl binding validation in order to provide more helpful diagnostic
for this quite frequent class of errors.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
index 677c94e063..f1dd00d4cd 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
@@ -224,7 +224,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
       val Apply(_, pickledPayload) = wrapped
       val payload = pickledPayload.map{ case Assign(k, v) => (unpickleAtom(k), unpickleAtom(v)) }.toMap
 
-      def fail(msg: String) = abort(s"bad macro impl binding: $msg")
+      def fail(msg: String) = typer.TyperErrorGen.MacroIncompatibleEngineError(msg)
       def unpickle[T](field: String, clazz: Class[T]): T = {
         def failField(msg: String) = fail(s"$field $msg")
         if (!payload.contains(field)) failField("is supposed to be there")
@@ -237,7 +237,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
       }
 
       val macroEngine = unpickle("macroEngine", classOf[String])
-      if (self.macroEngine != macroEngine) typer.TyperErrorGen.MacroIncompatibleEngineError(macroEngine)
+      if (self.macroEngine != macroEngine) typer.TyperErrorGen.MacroIncompatibleEngineError(s"expected = ${self.macroEngine}, actual = $macroEngine")
 
       val isBundle = unpickle("isBundle", classOf[Boolean])
       val isBlackbox = unpickle("isBlackbox", classOf[Boolean])