1 files changed, 49 insertions, 0 deletions
diff --git a/src/main/scala/chisel3/stage/phases/Checks.scala b/src/main/scala/chisel3/stage/phases/Checks.scala
new file mode 100644
index 00000000..e2606019
--- /dev/null
+++ b/src/main/scala/chisel3/stage/phases/Checks.scala
@@ -0,0 +1,49 @@
+// See LICENSE for license details.
+
+package chisel3.stage.phases
+
+import chisel3.stage.{ChiselOutputFileAnnotation, NoRunFirrtlCompilerAnnotation, PrintFullStackTraceAnnotation}
+
+import firrtl.AnnotationSeq
+import firrtl.annotations.Annotation
+import firrtl.options.{OptionsException, Phase}
+
+/** Sanity checks an [[firrtl.AnnotationSeq]] before running the main [[firrtl.options.Phase]]s of
+  * [[chisel3.stage.ChiselStage]].
+  */
+class Checks extends Phase {
+
+  def transform(annotations: AnnotationSeq): AnnotationSeq = {
+    val noF, st, outF = collection.mutable.ListBuffer[Annotation]()
+    annotations.foreach {
+      case a: NoRunFirrtlCompilerAnnotation.type => a +=: noF
+      case a: PrintFullStackTraceAnnotation.type => a +=: st
+      case a: ChiselOutputFileAnnotation         => a +=: outF
+      case _ =>
+    }
+
+    if (noF.size > 1) {
+      throw new OptionsException(
+        s"""|At most one NoRunFirrtlCompilerAnnotation can be specified, but found '${noF.size}'. Did you duplicate:
+            |    - option or annotation: -chnrf, --no-run-firrtl, NoRunFirrtlCompilerAnnotation
+            |""".stripMargin)
+    }
+
+    if (st.size > 1) {
+      throw new OptionsException(
+        s"""|At most one PrintFullStackTraceAnnotation can be specified, but found '${noF.size}'. Did you duplicate:
+            |    - option or annotation: --full-stacktrace, PrintFullStackTraceAnnotation
+            |""".stripMargin)
+    }
+
+    if (outF.size > 1) {
+      throw new OptionsException(
+        s"""|At most one Chisel output file can be specified but found '${outF.size}'. Did you duplicate:
+            |    - option or annotation: --chisel-output-file, ChiselOutputFileAnnotation
+            |""".stripMargin)
+    }
+
+    annotations
+  }
+
+}