hdl.dsl: bring new naming rules to submodules

Author: tpwrules

amaranth/hdl/_dsl.py

@@ -615,6 +615,7 @@ def _add_submodule(self, submodule, name=None, src_loc=None):
         if name == None:
             self._anon_submodules.append((submodule, src_loc))
         else:
+            validate_name(name, "Submodule name")
             if name in self._named_submodules:
                 raise NameError(f"Submodule named '{name}' already exists")
             self._named_submodules[name] = (submodule, src_loc)

tests/test_hdl_dsl.py

@@ -900,6 +900,16 @@ def test_submodule_named_index(self):
         self.assertEqual(m1._named_submodules.keys(), {"foo"})
         self.assertEqual(m1._named_submodules["foo"][0], m2)
 
+    def test_submodule_wrong_name(self):
+        m1 = Module()
+        m2 = Module()
+        with self.assertRaisesRegex(TypeError,
+                r"^Submodule name must be a string, not 1$"):
+            m1.submodules[1] = m2
+        with self.assertRaisesRegex(NameError,
+                r"^Submodule name must be a non-empty string$"):
+            m1.submodules[""] = m2
+
     def test_submodule_wrong(self):
         m = Module()
         with self.assertRaisesRegex(TypeError,