[smem] fix read-under-write serialization (#2595)

* [smem] fix read-under-write serialization

Also adds some tests for the parser and
the serializer.

* Serializer: always serialize smem ruw behavior

* test: simplify smem test circuit

1 files changed, 15 insertions, 0 deletions

diff --git a/src/test/scala/firrtlTests/SerializerSpec.scala b/src/test/scala/firrtlTests/SerializerSpec.scala
index 9a984d60..0e72b97f 100644
--- a/src/test/scala/firrtlTests/SerializerSpec.scala
+++ b/src/test/scala/firrtlTests/SerializerSpec.scala
@@ -121,4 +121,19 @@ class SerializerSpec extends AnyFlatSpec with Matchers {
     val serialized = Serializer.serialize(when, 1)
     serialized should be("  when cond :\n    skip\n")
   }
+
+  it should "serialize read-under-write behavior for smems correctly" in {
+    def parseSerializeParse(src: String): Circuit = Parser.parse(Parser.parse(src).serialize)
+    val undefined = parseSerializeParse(SMemTestCircuit.src(""))
+    assert(SMemTestCircuit.findRuw(undefined) == ReadUnderWrite.Undefined)
+
+    val undefined2 = parseSerializeParse(SMemTestCircuit.src(" undefined"))
+    assert(SMemTestCircuit.findRuw(undefined2) == ReadUnderWrite.Undefined)
+
+    val old = parseSerializeParse(SMemTestCircuit.src(" old"))
+    assert(SMemTestCircuit.findRuw(old) == ReadUnderWrite.Old)
+
+    val readNew = parseSerializeParse(SMemTestCircuit.src(" new"))
+    assert(SMemTestCircuit.findRuw(readNew) == ReadUnderWrite.New)
+  }
 }