diff options
Diffstat (limited to 'core')
-rw-r--r-- | core/shared/src/main/scala/interface.scala | 12 | ||||
-rw-r--r-- | core/shared/src/main/scala/magnolia.scala | 8 |
2 files changed, 19 insertions, 1 deletions
diff --git a/core/shared/src/main/scala/interface.scala b/core/shared/src/main/scala/interface.scala index 05803f0..51abc22 100644 --- a/core/shared/src/main/scala/interface.scala +++ b/core/shared/src/main/scala/interface.scala @@ -188,4 +188,14 @@ final class SealedTrait[Typeclass[_], Type](val typeName: TypeName, */ final case class TypeName(owner: String, short: String) { def full: String = s"$owner.$short" -}
\ No newline at end of file +} + +/** + * This annotation can be attached to the implicit `gen` method of a type class companion, + * which is implemented by the `Magnolia.gen` macro. + * It causes magnolia to dump the macro-generated code to the console during compilation. + * + * @param typeNamePart If non-empty restricts the output generation to types + * whose full name contains the given [[String]] + */ +final class debug(typeNamePart: String = "") extends scala.annotation.StaticAnnotation diff --git a/core/shared/src/main/scala/magnolia.scala b/core/shared/src/main/scala/magnolia.scala index b61d1c0..b5c196a 100644 --- a/core/shared/src/main/scala/magnolia.scala +++ b/core/shared/src/main/scala/magnolia.scala @@ -69,6 +69,10 @@ object Magnolia { import c.universe._ import internal._ + val debug = c.macroApplication.symbol.annotations + .find(_.tree.tpe <:< typeOf[debug]) + .flatMap(_.tree.children.tail.collectFirst { case Literal(Constant(s: String)) => s }) + val magnoliaPkg = q"_root_.magnolia" val scalaPkg = q"_root_.scala" @@ -447,6 +451,10 @@ object Magnolia { if (currentStack.frames.isEmpty) recursionStack = ListMap() val dereferencedResult = result.map { tree => + if (debug.isDefined && genericType.toString.contains(debug.get)) { + c.echo(c.enclosingPosition, s"Magnolia macro expansion for $genericType") + c.echo(NoPosition, s"... = ${showCode(tree)}\n\n") + } if (currentStack.frames.isEmpty) c.untypecheck(removeDeferred.transform(tree)) else tree } |