Update license action to update license checkstyle header if it exists

Author: ryanjbaxter

.github/actions/update-license-headers/action.yml

@@ -49,6 +49,18 @@ runs:
         git config user.name "${{ inputs.git-user-name }}"
         git config user.email "${{ inputs.git-user-email }}"
 
+        # Update checkstyle-header.txt files — committed separately
+        echo "Scanning for checkstyle-header.txt files..."
+        python3 "${{ github.action_path }}/update_checkstyle_header.py" .
+
+        git add .
+        if ! git diff --cached --quiet; then
+          git commit -m "Updating checkstyle header"
+          echo "Checkstyle header committed."
+        else
+          echo "No checkstyle header changes to commit."
+        fi
+
         # Replace Apache License 2.0 headers across all source files
         echo "Scanning for Apache License headers..."
         python3 "${{ github.action_path }}/update_licenses.py" .

.github/actions/update-license-headers/update_checkstyle_header.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""
+Finds every checkstyle-header.txt in the repository and replaces its content
+with the Broadcom license header pattern for Checkstyle.
+"""
+
+import os
+import sys
+
+CHECKSTYLE_HEADER = (
+    "^\\Q/*\\E$\n"
+    "^\\Q * Copyright \u00a9 \\E20\\d\\d\\Q Broadcom Inc. and/or its subsidiaries. All Rights Reserved.\\E$\n"
+    "^\\Q * Copyright \\E20\\d\\d\\-present\\Q the original author or authors.\\E$\n"
+    "^\\Q */\\E$\n"
+    "^$\n"
+    "^.*$\n"
+)
+
+SKIP_DIRS = frozenset([
+    ".git", "node_modules", "target", "build",
+    ".gradle", "__pycache__", ".mvn", ".idea",
+])
+
+
+def main():
+    root = sys.argv[1] if len(sys.argv) > 1 else "."
+    changed = 0
+    for dirpath, dirnames, filenames in os.walk(root, topdown=True):
+        dirnames[:] = [d for d in dirnames if d not in SKIP_DIRS]
+        for fname in filenames:
+            if fname != "checkstyle-header.txt":
+                continue
+            path = os.path.join(dirpath, fname)
+            try:
+                with open(path, "r", encoding="utf-8") as f:
+                    current = f.read()
+                if current == CHECKSTYLE_HEADER:
+                    print(f"  Already up to date: {path}")
+                    continue
+                with open(path, "w", encoding="utf-8") as f:
+                    f.write(CHECKSTYLE_HEADER)
+                print(f"  Updated: {path}")
+                changed += 1
+            except Exception as e:
+                print(f"  WARNING: cannot process {path}: {e}")
+    print(f"\nUpdated checkstyle headers in {changed} file(s).")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())