fhdl.ast.Signal: assign an internal name if tracer fails.

diff --git a/nmigen/fhdl/ast.py b/nmigen/fhdl/ast.py
index 198b5c4b522865407c34e22dcb957899ee3918b1..b78021f89d4b5d6db32200d8e41a67400cb6e6a3 100644 (file)
--- a/nmigen/fhdl/ast.py
+++ b/nmigen/fhdl/ast.py
@@ -505,7 +505,10 @@ class Signal(Value, DUID):
         super().__init__()
 
         if name is None:
-            name = tracer.get_var_name()
+            try:
+                name = tracer.get_var_name()
+            except tracer.NameNotFound:
+                name = "$signal"
         self.name = name
 
         if isinstance(bits_sign, int):