From 36f465e26455168f357c63fbfc2f456034031f3c Mon Sep 17 00:00:00 2001
From: whitequark <cz@m-labs.hk>
Date: Thu, 13 Dec 2018 15:24:55 +0000
Subject: [PATCH] fhdl.cd: rename ClockDomain signals together with domain.

---
 nmigen/fhdl/cd.py           | 18 ++++++++++++++++--
 nmigen/fhdl/xfrm.py         |  2 +-
 nmigen/test/test_fhdl_cd.py | 16 ++++++++++++++++
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/nmigen/fhdl/cd.py b/nmigen/fhdl/cd.py
index 09d930a..85c6b71 100644
--- a/nmigen/fhdl/cd.py
+++ b/nmigen/fhdl/cd.py
@@ -30,6 +30,14 @@ class ClockDomain:
     rst : Signal or None, inout
         Reset signal for this domain. Can be driven or used to drive.
     """
+
+    @staticmethod
+    def _name_for(domain_name, signal_name):
+        if domain_name == "sync":
+            return signal_name
+        else:
+            return "{}_{}".format(domain_name, signal_name)
+
     def __init__(self, name=None, reset_less=False, async_reset=False):
         if name is None:
             try:
@@ -40,10 +48,16 @@ class ClockDomain:
             name = name[3:]
         self.name = name
 
-        self.clk = Signal(name=self.name + "_clk", src_loc_at=1)
+        self.clk = Signal(name=self._name_for(name, "clk"), src_loc_at=1)
         if reset_less:
             self.rst = None
         else:
-            self.rst = Signal(name=self.name + "_rst", src_loc_at=1)
+            self.rst = Signal(name=self._name_for(name, "rst"), src_loc_at=1)
 
         self.async_reset = async_reset
+
+    def rename(self, name):
+        self.name = name
+        self.clk.name = self._name_for(name, "clk")
+        if self.rst is not None:
+            self.rst.name = self._name_for(name, "rst")
diff --git a/nmigen/fhdl/xfrm.py b/nmigen/fhdl/xfrm.py
index 2c74e43..c32083e 100644
--- a/nmigen/fhdl/xfrm.py
+++ b/nmigen/fhdl/xfrm.py
@@ -153,7 +153,7 @@ class DomainRenamer(FragmentTransformer, ValueTransformer, StatementTransformer)
             if domain in self.domain_map:
                 if cd.name == domain:
                     # Rename the actual ClockDomain object.
-                    cd.name = self.domain_map[domain]
+                    cd.rename(self.domain_map[domain])
                 else:
                     assert cd.name == self.domain_map[domain]
             new_fragment.add_domains(cd)
diff --git a/nmigen/test/test_fhdl_cd.py b/nmigen/test/test_fhdl_cd.py
index 8b453de..2ec8fb6 100644
--- a/nmigen/test/test_fhdl_cd.py
+++ b/nmigen/test/test_fhdl_cd.py
@@ -4,8 +4,14 @@ from .tools import *
 
 class ClockDomainCase(FHDLTestCase):
     def test_name(self):
+        sync = ClockDomain()
+        self.assertEqual(sync.name, "sync")
+        self.assertEqual(sync.clk.name, "clk")
+        self.assertEqual(sync.rst.name, "rst")
         pix = ClockDomain()
         self.assertEqual(pix.name, "pix")
+        self.assertEqual(pix.clk.name, "pix_clk")
+        self.assertEqual(pix.rst.name, "pix_rst")
         cd_pix = ClockDomain()
         self.assertEqual(pix.name, "pix")
         dom = [ClockDomain("foo")][0]
@@ -31,3 +37,13 @@ class ClockDomainCase(FHDLTestCase):
         self.assertIsNotNone(pix.clk)
         self.assertIsNotNone(pix.rst)
         self.assertTrue(pix.async_reset)
+
+    def test_rename(self):
+        sync = ClockDomain()
+        self.assertEqual(sync.name, "sync")
+        self.assertEqual(sync.clk.name, "clk")
+        self.assertEqual(sync.rst.name, "rst")
+        sync.rename("pix")
+        self.assertEqual(sync.name, "pix")
+        self.assertEqual(sync.clk.name, "pix_clk")
+        self.assertEqual(sync.rst.name, "pix_rst")
-- 
2.30.2