From f953a516d083054202f9ada0191f02f99abed725 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Fran=C3=A7ois=20Nguyen?= <jf@jfng.fr>
Date: Fri, 11 Oct 2024 23:24:13 +0200
Subject: [PATCH] cxxrtl: fix handling of 0-bit variables in
 `vcd_writer.sample()`.

---
 backends/cxxrtl/runtime/cxxrtl/cxxrtl_vcd.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/backends/cxxrtl/runtime/cxxrtl/cxxrtl_vcd.h b/backends/cxxrtl/runtime/cxxrtl/cxxrtl_vcd.h
index e4c9a67702c..e8be7002814 100644
--- a/backends/cxxrtl/runtime/cxxrtl/cxxrtl_vcd.h
+++ b/backends/cxxrtl/runtime/cxxrtl/cxxrtl_vcd.h
@@ -127,6 +127,8 @@ class vcd_writer {
 			bool bit_curr = var.curr[bit / (8 * sizeof(chunk_t))] & (1 << (bit % (8 * sizeof(chunk_t))));
 			buffer += (bit_curr ? '1' : '0');
 		}
+		if (var.width == 0)
+			buffer += '0';
 		buffer += ' ';
 		emit_ident(var.ident);
 		buffer += '\n';