[PyCDE] Disabling Handshake-DC tests

Since the DC flow is broken, disabling the test and flow.
http://github.com/llvm/circt/issues/7949

frontends/PyCDE/integration_test/esi_test.py

@@ -109,6 +109,10 @@ def construct(ports):
 
 
 class JoinAddFunc(Func):
+  # This test is broken since the DC dialect flow is broken. Leaving the code
+  # here in case it gets fixed in the future.
+  # https://github.com/llvm/circt/issues/7949 is the latest layer of the onion.
+
   a = Input(UInt(32))
   b = Input(UInt(32))
   x = Output(UInt(32))
@@ -119,6 +123,7 @@ def construct(ports):
 
 
 class Join(Module):
+  # This test is broken since the JoinAddFunc function is broken.
   clk = Clock()
   rst = Reset()
 
@@ -141,7 +146,9 @@ def construct(ports):
       MMIOClient(i)()
     MMIOReadWriteClient(clk=ports.clk, rst=ports.rst)
     ConstProducer(clk=ports.clk, rst=ports.rst)
-    Join(clk=ports.clk, rst=ports.rst)
+
+    # Disable broken test.
+    # Join(clk=ports.clk, rst=ports.rst)
 
 
 if __name__ == "__main__":

frontends/PyCDE/integration_test/test_software/esi_test.py

@@ -148,15 +148,18 @@ def read_offset_check(i: int, add_amt: int):
 # Handshake JoinAddFunc tests
 ################################################################################
 
-a = d.ports[esi.AppID("join_a")].write_port("data")
-a.connect()
-b = d.ports[esi.AppID("join_b")].write_port("data")
-b.connect()
-x = d.ports[esi.AppID("join_x")].read_port("data")
-x.connect()
-
-a.write(15)
-b.write(24)
-xdata = x.read()
-print(f"join: {xdata}")
-assert xdata == 15 + 24
+# Disabled test since the DC dialect flow is broken. Leaving the code here in
+# case someone fixes it.
+
+# a = d.ports[esi.AppID("join_a")].write_port("data")
+# a.connect()
+# b = d.ports[esi.AppID("join_b")].write_port("data")
+# b.connect()
+# x = d.ports[esi.AppID("join_x")].read_port("data")
+# x.connect()
+
+# a.write(15)
+# b.write(24)
+# xdata = x.read()
+# print(f"join: {xdata}")
+# assert xdata == 15 + 24

frontends/PyCDE/src/pycde/handshake.py

@@ -3,6 +3,7 @@
 #  SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 from __future__ import annotations
+import sys
 from typing import List, Optional, Dict, Tuple
 
 from .module import Module, ModuleLikeBuilderBase, PortError
@@ -41,6 +42,10 @@ def create_op(self, sys: System, symbol):
   def generate(self):
     """Fill in (generate) this module. Only supports a single generator
     currently."""
+
+    print(
+        sys.stderr, "WARNING: the Func handshake flow is currently broken "
+        "and thus disabled.")
     if len(self.generators) != 1:
       raise ValueError("Must have exactly one generator.")
     g: Generator = list(self.generators.values())[0]
@@ -121,7 +126,11 @@ class Func(Module):
   to hardware design.
 
   The PyCDE interface to it (this class) is considered experimental. Use at your
-  own risk and test the resulting RTL thoroughly."""
+  own risk and test the resulting RTL thoroughly.
+
+  Warning: the DC flow is currently broken and thus disabled. Do not use this.
+  https://github.com/llvm/circt/issues/7949
+  """
 
   BuilderType: type[ModuleLikeBuilderBase] = FuncBuilder
   _builder: FuncBuilder

frontends/PyCDE/src/pycde/system.py

@@ -262,10 +262,15 @@ def get_instance(self,
       lambda sys: TypeAlias.declare_aliases(sys.mod),
 
       # Then run all the passes to lower dialects which produce `hw.module`s.
-      "builtin.module(lower-handshake-to-dc)",
-      "builtin.module(dc-materialize-forks-sinks)",
-      "builtin.module(lower-dc-to-hw)",
-      "builtin.module(map-arith-to-comb)",
+
+      # The DC flow is broken, so don't bother running these passes. Leaving
+      # them in case someone fixes it in the future.
+      # https://github.com/llvm/circt/issues/7949 is the latest layer of the
+      # onion.
+      # "builtin.module(lower-handshake-to-dc)",
+      # "builtin.module(dc-materialize-forks-sinks)",
+      # "builtin.module(lower-dc-to-hw)",
+      # "builtin.module(map-arith-to-comb)",
 
       # Run ESI manifest passes.
       "builtin.module(esi-appid-hier{{top={tops} }}, esi-build-manifest{{top={tops} }})",