Emit signal groups in GTKW files

amaranth/sim/core.py

@@ -210,17 +210,25 @@ def write_vcd(self, vcd_file, gtkw_file=None, *, traces=(), fs_per_delta=0):
                     file.close()
             raise ValueError("Cannot start writing waveforms after advancing simulation time")
 
-        for trace in traces:
-            if isinstance(trace, ValueLike):
-                trace_cast = Value.cast(trace)
+        def traverse_traces(traces):
+            if isinstance(traces, ValueLike):
+                trace_cast = Value.cast(traces)
                 if isinstance(trace_cast, MemoryData._Row):
-                    continue
+                    return
                 for trace_signal in trace_cast._rhs_signals():
                     if trace_signal.name == "":
-                        if trace_signal is trace:
+                        if trace_signal is traces:
                             raise TypeError("Cannot trace signal with private name")
                         else:
-                            raise TypeError(f"Cannot trace signal with private name (within {trace!r})")
+                            raise TypeError(f"Cannot trace signal with private name (within {traces!r})")
+            elif isinstance(traces, (list, tuple)):
+                for trace in traces:
+                    traverse_traces(trace)
+            elif isinstance(traces, dict):
+                for trace in traces.values():
+                    traverse_traces(trace)
+
+        traverse_traces(traces)
 
         return self._engine.write_vcd(vcd_file=vcd_file, gtkw_file=gtkw_file,
                                       traces=traces, fs_per_delta=fs_per_delta)

amaranth/sim/pysim.py

@@ -5,7 +5,9 @@
 import enum as py_enum
 
 from ..hdl import *
+from ..hdl._mem import MemoryInstance
 from ..hdl._ast import SignalDict
+from ..lib import data, wiring
 from ._base import *
 from ._async import *
 from ._pyeval import eval_format, eval_value, eval_assign
@@ -49,7 +51,7 @@
         self.gtkw_file = gtkw_file
         self.gtkw_save = gtkw_file and vcd.gtkw.GTKWSave(self.gtkw_file)
 
-        self.traces = []
+        self.traces = traces
 
         signal_names = SignalDict()
         memories = {}
@@ -64,9 +66,9 @@
 
         trace_names = SignalDict()
         assigned_names = set()
-        for trace in traces:
-            if isinstance(trace, ValueLike):
-                trace = Value.cast(trace)
+        def traverse_traces(traces):
+            if isinstance(traces, ValueLike):
+                trace = Value.cast(traces)
                 if isinstance(trace, MemoryData._Row):
                     memory = trace._memory
                     if not memory in memories:
@@ -77,7 +79,6 @@
                             assert name not in assigned_names
                         memories[memory] = ("bench", name)
                         assigned_names.add(name)
-                    self.traces.append(trace)
                 else:
                     for trace_signal in trace._rhs_signals():
                         if trace_signal not in signal_names:
@@ -88,19 +89,27 @@
                                 assert name not in assigned_names
                             trace_names[trace_signal] = {("bench", name)}
                             assigned_names.add(name)
-                        self.traces.append(trace_signal)
-            elif isinstance(trace, MemoryData):
-                if not trace in memories:
-                    if trace.name not in assigned_names:
-                        name = trace.name
+            elif isinstance(traces, MemoryData):
+                if not traces in memories:
+                    if traces.name not in assigned_names:
+                        name = traces.name
                     else:
-                        name = f"{trace.name}${len(assigned_names)}"
+                        name = f"{traces.name}${len(assigned_names)}"
                         assert name not in assigned_names
-                    memories[trace] = ("bench", name)
+                    memories[traces] = ("bench", name)
                     assigned_names.add(name)
-                self.traces.append(trace)
+            elif hasattr(traces, "signature") and isinstance(traces.signature, wiring.Signature):
+                for name in traces.signature.members:
+                    traverse_traces(getattr(traces, name))
+            elif isinstance(traces, list) or isinstance(traces, tuple):
+                for trace in traces:
+                    traverse_traces(trace)
+            elif isinstance(traces, dict):
+                for trace in traces.values():
+                    traverse_traces(trace)
             else:
-                raise TypeError(f"{trace!r} is not a traceable object")
+                raise TypeError(f"{traces!r} is not a traceable object")
+        traverse_traces(traces)
 
         if self.vcd_writer is None:
             return
@@ -277,19 +286,40 @@
             self.gtkw_save.dumpfile_size(self.vcd_file.tell())
 
             self.gtkw_save.treeopen("top")
-            for trace in self.traces:
-                if isinstance(trace, Signal):
-                    for name in self.gtkw_signal_names[trace]:
+
+            def traverse_traces(traces):
+                if isinstance(traces, Signal):
+                    for name in self.gtkw_signal_names[traces]:
                         self.gtkw_save.trace(name)
-                elif isinstance(trace, MemoryData):
-                    for row_names in self.gtkw_memory_names[trace]:
+                elif isinstance(traces, data.View):
+                    with self.gtkw_save.group("view"):
+                        trace = Value.cast(traces)
+                        for trace_signal in trace._rhs_signals():
+                            for name in self.gtkw_signal_names[trace_signal]:
+                                self.gtkw_save.trace(name)
+                elif isinstance(traces, ValueLike):
+                    traverse_traces(Value.cast(traces))
+                elif isinstance(traces, MemoryData):
+                    for row_names in self.gtkw_memory_names[traces]:
                         for name in row_names:
                             self.gtkw_save.trace(name)
-                elif isinstance(trace, MemoryData._Row):
-                    for name in self.gtkw_memory_names[trace._memory][trace._index]:
+                elif isinstance(traces, MemoryData._Row):
+                    for name in self.gtkw_memory_names[traces._memory][traces._index]:
                         self.gtkw_save.trace(name)
+                elif hasattr(traces, "signature") and isinstance(traces.signature, wiring.Signature):
+                    with self.gtkw_save.group("interface"):
+                        for _, _, member in traces.signature.flatten(traces):
+                            traverse_traces(member)
+                elif isinstance(traces, list) or isinstance(traces, tuple):
+                    for trace in traces:
+                        traverse_traces(trace)
+                elif isinstance(traces, dict):
+                    for name, trace in traces.items():
+                        with self.gtkw_save.group(name):
+                            traverse_traces(trace)
                 else:
                     assert False # :nocov:
+            traverse_traces(self.traces)
 
         if self.close_vcd:
             self.vcd_file.close()

tests/test_sim.py

@@ -16,7 +16,7 @@
 from amaranth.sim import *
 from amaranth.sim._pyeval import eval_format
 from amaranth.lib.memory import Memory
-from amaranth.lib import enum, data
+from amaranth.lib import enum, data, wiring
 
 from .utils import *
 from amaranth._utils import _ignore_deprecated
@@ -1375,6 +1375,49 @@ def testbench():
             sim.add_testbench(testbench)
 
 
+class SimulatorTracesTestCase(FHDLTestCase):
+    def assertDef(self, traces, flat_traces):
+        frag = Fragment()
+
+        def process():
+            yield Delay(1e-6)
+
+        sim = Simulator(frag)
+        sim.add_testbench(process)
+        with sim.write_vcd("test.vcd", "test.gtkw", traces=traces):
+            sim.run()
+
+    def test_signal(self):
+        a = Signal()
+        self.assertDef(a, [a])
+
+    def test_list(self):
+        a = Signal()
+        self.assertDef([a], [a])
+
+    def test_tuple(self):
+        a = Signal()
+        self.assertDef((a,), [a])
+
+    def test_dict(self):
+        a = Signal()
+        self.assertDef({"a": a}, [a])
+
+    def test_struct_view(self):
+        a = Signal(data.StructLayout({"a": 1, "b": 3}))
+        self.assertDef(a, [a])
+
+    def test_interface(self):
+        sig = wiring.Signature({
+            "a": wiring.In(1),
+            "b": wiring.Out(3),
+            "c": wiring.Out(2).array(4),
+            "d": wiring.In(wiring.Signature({"e": wiring.In(5)}))
+        })
+        a = sig.create()
+        self.assertDef(a, [a])
+
+
 class SimulatorRegressionTestCase(FHDLTestCase):
     def test_bug_325(self):
         dut = Module()