Merge pull request #3606 from xeno-by/ticket/8375

SI-8375 saner binary incompat errors for macros

2 files changed, 13 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
index 2043eb5d5d..d439bb5603 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
@@ -725,11 +725,18 @@ trait ContextErrors {
         NormalTypeError(expandee, "too many argument lists for " + fun)
       }
 
-      def MacroIncompatibleEngineError(macroEngine: String) = {
-        val message = s"macro cannot be expanded, because it was compiled by an incompatible macro engine $macroEngine"
+      private def MacroIncompatibleEngineError(friendlyMessage: String, internalMessage: String) = {
+        def debugDiagnostic = s"(internal diagnostic: $internalMessage)"
+        val message = if (macroDebugLite || macroDebugVerbose) s"$friendlyMessage $debugDiagnostic" else friendlyMessage
         issueNormalTypeError(lastTreeToTyper, message)
       }
 
+      def MacroCantExpand210xMacrosError(internalMessage: String) =
+        MacroIncompatibleEngineError("can't expand macros compiled by previous versions of Scala", internalMessage)
+
+      def MacroCantExpandIncompatibleMacrosError(internalMessage: String) =
+        MacroIncompatibleEngineError("macro cannot be expanded, because it was compiled by an incompatible macro engine", internalMessage)
+
       case object MacroExpansionException extends Exception with scala.util.control.ControlThrowable
 
       protected def macroExpansionError(expandee: Tree, msg: String, pos: Position = NoPosition) = {
diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
index 677c94e063..9cf92ca5b9 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
@@ -224,7 +224,8 @@ 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: $msg")
+      import typer.TyperErrorGen._
+      def fail(msg: String) = MacroCantExpandIncompatibleMacrosError(msg)
       def unpickle[T](field: String, clazz: Class[T]): T = {
         def failField(msg: String) = fail(s"$field $msg")
         if (!payload.contains(field)) failField("is supposed to be there")
@@ -236,8 +237,9 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
         raw.asInstanceOf[T]
       }
 
+      if (!payload.contains("macroEngine")) MacroCantExpand210xMacrosError("macroEngine field not found")
       val macroEngine = unpickle("macroEngine", classOf[String])
-      if (self.macroEngine != macroEngine) typer.TyperErrorGen.MacroIncompatibleEngineError(macroEngine)
+      if (self.macroEngine != macroEngine) MacroCantExpandIncompatibleMacrosError(s"expected = ${self.macroEngine}, actual = $macroEngine")
 
       val isBundle = unpickle("isBundle", classOf[Boolean])
       val isBlackbox = unpickle("isBlackbox", classOf[Boolean])