1 files changed, 42 insertions, 0 deletions
diff --git a/src/main/scala/logger/phases/Checks.scala b/src/main/scala/logger/phases/Checks.scala
new file mode 100644
index 00000000..c706948c
--- /dev/null
+++ b/src/main/scala/logger/phases/Checks.scala
@@ -0,0 +1,42 @@
+// See LICENSE for license details.
+
+package logger.phases
+
+import firrtl.AnnotationSeq
+import firrtl.annotations.Annotation
+import firrtl.options.Phase
+
+import logger.{LogLevelAnnotation, LogFileAnnotation, LoggerException}
+
+import scala.collection.mutable
+
+/** Check that an [[firrtl.AnnotationSeq AnnotationSeq]] has all necessary [[firrtl.annotations.Annotation Annotation]]s
+  * for a [[Logger]] */
+object Checks extends Phase {
+
+  /** Ensure that an [[firrtl.AnnotationSeq AnnotationSeq]] has necessary [[Logger]] [[firrtl.annotations.Annotation
+    * Annotation]]s
+    * @param annotations input annotations
+    * @return input annotations unmodified
+    * @throws logger.LoggerException
+    */
+  def transform(annotations: AnnotationSeq): AnnotationSeq = {
+    val ll, lf = mutable.ListBuffer[Annotation]()
+    annotations.foreach(
+      _ match {
+        case a: LogLevelAnnotation => ll += a
+        case a: LogFileAnnotation  => lf += a
+        case _                     =>         })
+    if (ll.size > 1) {
+      val l = ll.map{ case LogLevelAnnotation(x) => x }
+      throw new LoggerException(
+        s"""|At most one log level can be specified, but found '${l.mkString(", ")}' specified via:
+            |    - an option or annotation: -ll, --log-level, LogLevelAnnotation""".stripMargin )}
+    if (lf.size > 1) {
+      throw new LoggerException(
+        s"""|At most one log file can be specified, but found ${lf.size} combinations of:
+            |    - an options or annotation: -ltf, --log-to-file, --log-file, LogFileAnnotation""".stripMargin )}
+    annotations
+  }
+
+}