From 103f1fa4bb8fb9688f6dfb0a8162f6bc2975e2fa Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Fri, 20 Nov 2020 17:01:15 +0000
Subject: [PATCH] Add enumeration assignment compatibility check for continuous
 assignments.

(cherry picked from commit 1b3f0dd689092d69f7a7407a7f2b311c3365825e)
---
 elaborate.cc | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/elaborate.cc b/elaborate.cc
index 81d4174b2..ae3345cde 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -110,6 +110,18 @@ void PGAssign::elaborate(Design*des, NetScope*scope) const
 	    return;
       }
 
+      if (lval->enumeration()) {
+	    if (! rval_expr->enumeration()) {
+		  cerr << get_fileline() << ": error: "
+		          "This assignment requires an explicit cast." << endl;
+		  des->errors += 1;
+	    } else if (! lval->enumeration()->matches(rval_expr->enumeration())) {
+		  cerr << get_fileline() << ": error: "
+		          "Enumeration type mismatch in assignment." << endl;
+		  des->errors += 1;
+	    }
+      }
+
       NetNet*rval = rval_expr->synthesize(des, scope, rval_expr);
 
       if (rval == 0) {