1 files changed, 42 insertions, 0 deletions
diff --git a/coreMacros/src/main/scala/chisel3/internal/RuntimeDeprecationTransform.scala b/coreMacros/src/main/scala/chisel3/internal/RuntimeDeprecationTransform.scala
new file mode 100644
index 00000000..baf5b746
--- /dev/null
+++ b/coreMacros/src/main/scala/chisel3/internal/RuntimeDeprecationTransform.scala
@@ -0,0 +1,42 @@
+// See LICENSE for license details.
+
+package chisel3.internal
+
+import scala.reflect.macros.whitebox.Context
+import scala.language.experimental.macros
+import scala.annotation.StaticAnnotation
+import scala.annotation.compileTimeOnly
+
+
+class RuntimeDeprecatedTransform(val c: Context) {
+  import c.universe._
+
+  /** Adds a Builder.deprecated(...) call based on the contents of a plain @deprecated annotation.
+    */
+  def runtimeDeprecated(annottees: c.Tree*): c.Tree = {
+    val transformed = annottees.map(annottee => annottee match {
+      case q"$mods def $tname[..$tparams](...$paramss): $tpt = $expr" => {
+        val Modifiers(_, _, annotations) = mods
+        val annotationMessage = annotations.collect {  // get all messages from deprecated annotations
+          case q"new deprecated($desc, $since)" => desc
+        } match {  // ensure there's only one and return it
+          case msg :: Nil => msg
+          case _ => c.abort(c.enclosingPosition, s"@chiselRuntimeDeprecated annotion must be used with exactly one @deprecated annotation, got annotations $annotations")
+        }
+        val message = s"$tname is deprecated: $annotationMessage"
+        val transformedExpr = q""" {
+        _root_.chisel3.internal.Builder.deprecated($message)
+        $expr
+        } """
+        q"$mods def $tname[..$tparams](...$paramss): $tpt = $transformedExpr"
+      }
+      case other => c.abort(c.enclosingPosition, s"@chiselRuntimeDeprecated annotion may only be used on defs, got ${showCode(other)}")
+    })
+    q"..$transformed"
+  }
+}
+
+@compileTimeOnly("enable macro paradise to expand macro annotations")
+class chiselRuntimeDeprecated extends StaticAnnotation {
+  def macroTransform(annottees: Any*): Any = macro chisel3.internal.RuntimeDeprecatedTransform.runtimeDeprecated
+}