Add base SystemC support

Author: desmonddak

.github/workflows/general.yml

@@ -61,17 +61,33 @@ jobs:
       - name: Install software - Icarus Verilog
         run: tool/gh_actions/install_iverilog.sh
 
+      - name: Install software - Accellera SystemC
+        run: tool/gh_actions/install_systemc.sh
+
+      - name: Pre-build SystemC PCH and Makefile
+        run: tool/gh_actions/setup_systemc_pch.sh
+
       - name: Run project tests
         run: tool/gh_actions/run_tests.sh
 
+      - name: Run SystemC tests
+        run: dart test test/systemc_vector_test.dart
+
+      - name: Clean SystemC temporary files
+        run: tool/gh_actions/cleanup_systemc_tmp.sh
+
       - name: Check temporary test files
         run: tool/gh_actions/check_tmp_test.sh
 
       # https://github.com/devcontainers/ci/blob/main/docs/github-action.md
       - name: Build dev container and run tests in it
         uses: devcontainers/ci@v0.3
         with:
-          runCmd: tool/gh_actions/run_tests.sh
+          runCmd: |
+            tool/gh_actions/run_tests.sh
+            dart test test/systemc_vector_test.dart
+            tool/gh_actions/cleanup_systemc_tmp.sh
+            tool/gh_actions/check_tmp_test.sh
 
   deploy-documentation:
     name: Deploy Documentation

README.md

@@ -9,7 +9,6 @@
 [![Chat](https://img.shields.io/discord/1001179329411166267?label=Chat)](https://discord.gg/jubxF84yGw)
 [![License](https://img.shields.io/badge/License-BSD--3-blue)](https://github.com/intel/rohd/blob/main/LICENSE)
 [![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-2.1-4baaaa.svg)](https://github.com/intel/rohd/blob/main/CODE_OF_CONDUCT.md)
-[![Coverage](https://raw.githubusercontent.com/intel/rohd/refs/heads/badges/coverage/main.svg)](https://github.com/intel/rohd/blob/main/.github/workflows/coverage.yml)
 
 ROHD (pronounced like "road") is a framework for describing and verifying hardware in the Dart programming language.
 
@@ -45,7 +44,7 @@ You can also open this repository in a GitHub Codespace to run the example in yo
 - **Simple and fast build**, free of complex build systems and EDA vendor tools
 - Can use the excellent pub.dev **package manager** and all the packages it has to offer
 - Built-in event-based **fast simulator** with **4-value** (0, 1, X, and Z) support and a **waveform dumper** to .vcd file format
-- Conversion of modules to equivalent, human-readable, structurally similar **SystemVerilog** for integration or downstream tool consumption
+- Conversion of modules to equivalent, human-readable, structurally similar **SystemVerilog** and **SystemC** for integration or downstream tool consumption
 - **Run-time dynamic** module port definitions (numbers, names, widths, etc.) and internal module logic, including recursive module contents
 - Leverage the [ROHD Hardware Component Library (ROHD-HCL)](https://github.com/intel/rohd-hcl) with reusable and configurable design and verification components.
 - Simple, free, **open source tool stack** without any headaches from library dependencies, file ordering, elaboration/analysis options, +defines, etc.
@@ -69,5 +68,6 @@ One of ROHD's goals is to help grow an open-source community around reusable har
 ROHD is under active development.  If you're interested in contributing, have feedback or a question, or found a bug, please see [CONTRIBUTING.md](https://github.com/intel/rohd/blob/main/CONTRIBUTING.md).
 
 ----------------
+
 Copyright (C) 2021-2026 Intel Corporation  
 SPDX-License-Identifier: BSD-3-Clause

dart_test.yaml

@@ -0,0 +1,15 @@
+# Test configuration for ROHD.
+#
+# To exclude FFI-dependent tests (e.g. in CI without native code support):
+#   dart test --preset no-ffi
+#
+# To run all tests including FFI (requires native shared libraries):
+#   dart test
+
+tags:
+  ffi:
+    # Tests requiring dart:ffi and native shared libraries.
+
+presets:
+  no-ffi:
+    exclude_tags: ffi

doc/architecture.md

@@ -24,7 +24,7 @@ The `Simulator` acts as a statically accessible driver of the overall simulation
 
 ### Synthesizer
 
-A separate type of object responsible for taking a `Module` and converting it to some output, such as SystemVerilog.
+A separate type of object responsible for taking a `Module` and converting it to some output, such as SystemVerilog or SystemC.
 
 ## Organization
 
@@ -44,7 +44,7 @@ Contains a collection of `Module` implementations that can be used as primitive
 
 ### Synthesizers
 
-Contains logic for synthesizing `Module`s into some output. It is structured to maximize reusability across different output types (including those not yet supported).
+Contains logic for synthesizing `Module`s into some output (e.g. SystemVerilog, SystemC). It is structured to maximize reusability across different output types.
 
 ### Utilities
 

doc/user_guide/_docs/A21-generation.md

@@ -5,7 +5,7 @@ last_modified_at: 2023-11-13
 toc: true
 ---
 
-Hardware in ROHD is convertible to an output format via `Synthesizer`s, the most popular of which is SystemVerilog. Hardware in ROHD can be converted to logically equivalent, human-readable SystemVerilog with structure, hierarchy, ports, and names maintained.
+Hardware in ROHD is convertible to an output format via `Synthesizer`s. The most popular output format is SystemVerilog, with SystemC also available. Hardware in ROHD can be converted to logically equivalent, human-readable SystemVerilog or SystemC with structure, hierarchy, ports, and names maintained.
 
 The simplest way to generate SystemVerilog is with the helper method `generateSynth` in `Module`:
 
@@ -28,6 +28,26 @@ void main() async {
 
 The `generateSynth` function will return a `String` with the SystemVerilog `module` definitions for the top-level it is called on, as well as any sub-modules (recursively).  You can dump the entire contents to a file and use it anywhere you would any other SystemVerilog.
 
+## SystemC generation
+
+ROHD can also generate SystemC (C++ with the SystemC library) from the same hardware description. Use the `generateSystemC` helper method:
+
+```dart
+void main() async {
+    final myModule = MyModule();
+    await myModule.build();
+
+    final generatedSc = myModule.generateSystemC();
+
+    // write it to a file
+    File('myHardware.h').writeAsStringSync(generatedSc);
+}
+```
+
+The generated SystemC uses `SC_MODULE`, `SC_METHOD`, and `SC_CTHREAD` constructs. Combinational logic becomes `SC_METHOD` processes, sequential logic (flip-flops and `Sequential` blocks) sharing the same clock and reset are consolidated into a single `SC_CTHREAD`, and sub-modules are instantiated with port bindings. All signal types map to SystemC equivalents (`bool`, `sc_uint<N>`, `sc_biguint<N>`).
+
+For more control over SystemC generation, use `SynthBuilder` with `SystemCSynthesizer()` directly.
+
 ## Controlling naming
 
 ### Modules

doc/user_guide/_get-started/01-overview.md

@@ -19,7 +19,7 @@ Features of ROHD include:
 - **Simple and fast build**, free of complex build systems and EDA vendor tools
 - Can use the excellent pub.dev **package manager** and all the packages it has to offer
 - Built-in event-based **fast simulator** with **4-value** (0, 1, X, and Z) support and a **waveform dumper** to .vcd file format
-- Conversion of modules to equivalent, human-readable, structurally similar **SystemVerilog** for integration or downstream tool consumption
+- Conversion of modules to equivalent, human-readable, structurally similar **SystemVerilog** and **SystemC** for integration or downstream tool consumption
 - **Run-time dynamic** module port definitions (numbers, names, widths, etc.) and internal module logic, including recursive module contents
 - Leverage the [ROHD Hardware Component Library (ROHD-HCL)](https://github.com/intel/rohd-hcl) with reusable and configurable design and verification components.
 - Simple, free, **open source tool stack** without any headaches from library dependencies, file ordering, elaboration/analysis options, +defines, etc.

lib/src/module.dart

@@ -14,6 +14,7 @@ import 'package:meta/meta.dart';
 import 'package:rohd/rohd.dart';
 import 'package:rohd/src/collections/traverseable_collection.dart';
 import 'package:rohd/src/diagnostics/inspector_service.dart';
+import 'package:rohd/src/synthesizers/systemc/systemc.dart';
 import 'package:rohd/src/utilities/config.dart';
 import 'package:rohd/src/utilities/namer.dart';
 import 'package:rohd/src/utilities/sanitizer.dart';
@@ -1155,6 +1156,27 @@ abstract class Module {
             .getSynthFileContents()
             .join('\n\n////////////////////\n\n');
   }
+
+  /// Returns a synthesized SystemC version of this [Module].
+  ///
+  /// Generates SystemC code that is equivalent to the hardware described by
+  /// this module, using the same naming strategy as [generateSynth].
+  String generateSystemC() {
+    if (!_hasBuilt) {
+      throw ModuleNotBuiltException(this);
+    }
+
+    final synthBuilder = SynthBuilder(this, SystemCSynthesizer());
+    final moduleContents =
+        synthBuilder.getSynthFileContents().map((e) => e.contents).join('\n');
+    return '// Generated by ROHD - www.github.com/intel/rohd\n'
+        '// Generation time: ${Timestamper.stamp()}\n'
+        '// ROHD Version: ${Config.version}\n'
+        '\n'
+        '#include <systemc.h>\n'
+        '\n'
+        '$moduleContents';
+  }
 }
 
 extension on LogicStructure {

lib/src/modules/conditionals/flop.dart

@@ -88,6 +88,11 @@ class FlipFlop extends Module with SystemVerilog {
   /// Only initialized if a constant value is provided.
   late LogicValue _resetValueConst;
 
+  /// Returns the constant reset value if one was provided, or null if the
+  /// reset value is a port or no reset exists.
+  LogicValue? get constantResetValue =>
+      _reset != null && _resetValuePort == null ? _resetValueConst : null;
+
   /// Indicates whether provided `reset` signals should be treated as an async
   /// reset. If no `reset` is provided, this will have no effect.
   final bool asyncReset;

lib/src/modules/conditionals/sequential.dart

@@ -135,6 +135,14 @@ class Sequential extends Always {
   /// The input edge triggers used in this block.
   final List<_SequentialTrigger> _triggers = [];
 
+  /// Returns the edge polarity for each trigger input port.
+  ///
+  /// Each entry pairs the trigger input port name with whether the trigger
+  /// fires on a positive edge (`true`) or negative edge (`false`).
+  List<({String portName, bool isPosedge})> get triggerEdges => _triggers
+      .map((t) => (portName: t.signal.name, isPosedge: t.isPosedge))
+      .toList();
+
   /// When `false`, an [SignalRedrivenException] will be thrown during
   /// simulation if the same signal is driven multiple times within this
   /// [Sequential].

lib/src/synthesizers/systemc/systemc.dart

@@ -0,0 +1,29 @@
+// Copyright (C) 2021-2026 Intel Corporation
+// SPDX-License-Identifier: BSD-3-Clause
+//
+// systemc_synthesizer.dart
+// Definition for SystemC Synthesizer
+//
+// 2026 May
+// Author: Desmond A. Kirkpatrick <desmond.a.kirkpatrick@intel.com>
+
+import 'package:rohd/rohd.dart';
+import 'package:rohd/src/synthesizers/systemc/systemc_synthesis_result.dart';
+
+/// A [Synthesizer] which generates equivalent SystemC as the given [Module].
+///
+/// Attempts to maintain signal naming and structure as much as possible,
+/// using the same naming strategy as the SystemVerilog synthesizer.
+class SystemCSynthesizer extends Synthesizer {
+  @override
+  bool generatesDefinition(Module module) =>
+      // ignore: deprecated_member_use_from_same_package
+      !((module is CustomSystemVerilog) ||
+          (module is SystemVerilog &&
+              module.generatedDefinitionType == DefinitionGenerationType.none));
+
+  @override
+  SynthesisResult synthesize(Module module,
+          String Function(Module module) getInstanceTypeOfModule) =>
+      SystemCSynthesisResult(module, getInstanceTypeOfModule);
+}