explicitly remove systemc artifacts

Author: desmonddak

.github/workflows/general.yml

@@ -73,6 +73,9 @@ jobs:
       - 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
 
@@ -83,6 +86,7 @@ jobs:
           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:

lib/src/utilities/simcompare.dart

@@ -523,8 +523,8 @@ abstract class SimCompare {
   /// Returns the directory containing systemc.h.gch, or null on failure.
   ///
   /// In CI, the PCH is pre-built by `tool/gh_actions/setup_systemc_pch.sh`
-  /// before tests run, so this first looks for the shared CI path. Locally,
-  /// each test process builds its own PCH directory to avoid parallel races.
+  /// before tests run. Locally, tests lazily build the same shared PCH under a
+  /// file lock so parallel test isolates can reuse it without racing.
   static String? _ensurePch(String scHome, String cxxStd) {
     if (_pchPath != null) {
       return _pchPath;
@@ -533,43 +533,57 @@ abstract class SimCompare {
     const dir = 'tmp_test';
     const sharedPchDir = '$dir/pch';
     const sharedGchFile = '$sharedPchDir/systemc.h.gch';
+    const lockFile = '$dir/pch.lock';
 
     // Reuse the CI-prebuilt PCH if available.
     if (File(sharedGchFile).existsSync()) {
       return _pchPath = sharedPchDir;
     }
 
-    final pchDir = '$dir/${_systemCTempPrefix}_pch';
-    final gchFile = '$pchDir/systemc.h.gch';
-
-    // Reuse if this process already built it on disk.
-    if (File(gchFile).existsSync()) {
-      return _pchPath = pchDir;
-    }
+    Directory(dir).createSync(recursive: true);
+    RandomAccessFile? lock;
+    try {
+      lock = File(lockFile).openSync(mode: FileMode.append)..lockSync();
 
-    Directory(pchDir).createSync(recursive: true);
+      if (File(sharedGchFile).existsSync()) {
+        return _pchPath = sharedPchDir;
+      }
 
-    // Copy the original header next to the .gch so g++ matches them.
-    final pchHeader = '$pchDir/systemc.h';
-    File('$scHome/systemc.h').copySync(pchHeader);
+      Directory(sharedPchDir).createSync(recursive: true);
+
+      // Copy the original header next to the .gch so g++ matches them.
+      const pchHeader = '$sharedPchDir/systemc.h';
+      File('$scHome/systemc.h').copySync(pchHeader);
+
+      final args = [
+        '-std=$cxxStd',
+        '-I$scHome',
+        '-x',
+        'c++-header',
+        '-o',
+        sharedGchFile,
+        pchHeader,
+      ];
+      final result = Process.runSync('g++', args);
+      if (result.exitCode != 0) {
+        print('PCH compilation failed (falling back to normal headers):');
+        print(result.stderr);
+        Directory(sharedPchDir).deleteSync(recursive: true);
+        return null;
+      }
 
-    final args = [
-      '-std=$cxxStd',
-      '-I$scHome',
-      '-x',
-      'c++-header',
-      '-o',
-      gchFile,
-      pchHeader,
-    ];
-    final result = Process.runSync('g++', args);
-    if (result.exitCode != 0) {
-      print('PCH compilation failed (falling back to normal headers):');
-      print(result.stderr);
+      return _pchPath = sharedPchDir;
+    } on Exception catch (e) {
+      print('PCH setup failed (falling back to normal headers): $e');
       return null;
+    } finally {
+      if (lock != null) {
+        try {
+          lock.unlockSync();
+        } on Exception catch (_) {}
+        lock.closeSync();
+      }
     }
-
-    return _pchPath = pchDir;
   }
 
   /// Resolves SystemC home/lib paths. If explicit paths are given, uses them.
@@ -638,6 +652,11 @@ abstract class SimCompare {
             continue;
           }
 
+          if (!keepPch && name == 'pch.lock') {
+            entity.deleteSync();
+            continue;
+          }
+
           // Leave everything else (iverilog files from parallel tests) alone
         }
       }

test/systemc_simcompare_test.dart

@@ -72,7 +72,7 @@ void main() {
   tearDown(() async {
     await Simulator.reset();
   });
-  tearDownAll(() => SimCompare.cleanupSystemCCache(keepPch: false));
+  tearDownAll(SimCompare.cleanupSystemCCache);
 
   group('SimCompare SystemC', () {
     test('gate module passes vectors', () async {

test/systemc_vector_test.dart

@@ -542,7 +542,7 @@ void main() {
     await Simulator.reset();
   });
 
-  tearDownAll(() => SimCompare.cleanupSystemCCache(keepPch: false));
+  tearDownAll(SimCompare.cleanupSystemCCache);
 
   // ===== Flop tests (from flop_test.dart) =====
   group('flop', () {

tool/gh_actions/cleanup_systemc_tmp.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# Copyright (C) 2026 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause
+#
+# cleanup_systemc_tmp.sh
+# GitHub Actions step helper: remove SystemC temporary build caches.
+#
+# 2026 June
+# Author: Desmond Kirkpatrick
+
+set -euo pipefail
+
+declare -r folder_name='tmp_test'
+
+if [ ! -d "${folder_name}" ]; then
+  exit 0
+fi
+
+find "${folder_name}" -mindepth 1 \
+  \( \
+    -name 'pch' -o \
+    -name 'pch.lock' -o \
+    -name 'tmp_sc_*' -o \
+    -name 'sc_input_*' -o \
+    -name 'Makefile_sc' \
+  \) \
+  -exec rm -rf {} +
+
+mkdir -p "${folder_name}"

tool/run_checks.sh

@@ -63,6 +63,10 @@ fi
 print_step 'Run project tests'
 tool/gh_actions/run_tests.sh
 
+# Clean SystemC temporary files
+print_step 'Clean SystemC temporary files'
+tool/gh_actions/cleanup_systemc_tmp.sh
+
 # Check temporary test files
 print_step 'Check temporary test files'
 tool/gh_actions/check_tmp_test.sh