save header change tool for posterity

Author: dhalbert

tools/circuitpy_header_change.py

@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+
+# This file is part of the CircuitPython project: https://circuitpython.org
+
+# SPDX-FileCopyrightText: Copyright (c) 2024 by Dan Halbert for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+#
+# Casual tool to help convert old-style copyright/license headers to SPDX and label
+# them as CircuitPython.
+#
+# Typical usages:
+# header_change.py *.c *.h --change
+# find boards common-hal/ peripherals/ supervisor/ -name '*.[ch]' |xargs header_change.py
+# find boards common-hal/ peripherals/ supervisor/ -name '*.[ch]' |xargs header_change.py --change
+
+import click
+import os
+import pathlib
+import re
+import sys
+
+SPDX_COPYRIGHT_RE = re.compile(r"(SPDX-FileCopyrightText:.*$)")
+ORIGINAL_COPYRIGHT_RE = re.compile(r"\* (.*Copyright .*[12].*$)", flags=re.IGNORECASE)
+MIT_LICENSE_RE = re.compile(r"MIT License", flags=re.IGNORECASE)
+
+
+def find_related_copyrights(filename):
+    path = pathlib.Path(filename)
+    copyrights = []
+
+    if "boards" in path.parts:
+        related_path = path.parent / "board.c"
+        if related_path.is_file():
+            with open(related_path, "r") as f:
+                for line in f.readlines():
+                    match = SPDX_COPYRIGHT_RE.search(line)
+                    if match:
+                        copyrights.append(f"// {match.group(1)}")
+                        continue
+                    match = ORIGINAL_COPYRIGHT_RE.search(line)
+                    if match:
+                        copyrights.append(f"// SPDX-FileCopyrightText: {match.group(1)}")
+
+    return copyrights
+
+
+def fix_file(filename, change):
+    copyrights = []
+    mit_license = False
+    empty_file = False
+    first_line = ""
+    no_existing_header = False
+
+    with open(filename, "r") as f:
+        lines = f.readlines()
+        if not lines:
+            empty_file = True
+            no_existing_header = True
+            mit_license = True
+            copyrights.append(
+                f"// SPDX-FileCopyrightText: Copyright (c) 2024 Adafruit Industries LLC"
+            )
+        else:
+            first_line = lines.pop(0)
+
+            if first_line.startswith("// SPDX"):
+                return "already SPDX"
+
+            if first_line.startswith("// This file is part of the CircuitPython"):
+                return "already converted to CircuitPython header"
+
+            if not first_line == "/*\n":
+                no_existing_header = True
+                mit_license = True
+
+                # Put back the line we just read, and add a blank line to separate the header as well.
+                lines.insert(0, first_line)
+                lines.insert(0, "\n")
+
+        while lines and not no_existing_header:
+            line = lines.pop(0)
+
+            if not line and not no_existing_header:
+                return "Could not find '*/'"
+
+            # Check that it's MIT-licensed
+            match = MIT_LICENSE_RE.search(line)
+            if match:
+                mit_license = True
+                continue
+
+            # If there's an SPDX copyright, just use it. There may be more than one
+            match = SPDX_COPYRIGHT_RE.search(line)
+            if match:
+                copyrights.append(f"// {match.group(1)}")
+                continue
+
+            # If it's a non-SPDX copyright, use the copyright text and put it in an SPDX-FileCopyrightText.
+            match = ORIGINAL_COPYRIGHT_RE.search(line)
+            if match:
+                copyrights.append(f"// SPDX-FileCopyrightText: {match.group(1)}")
+                continue
+
+            if line.strip() == "*/":
+                break
+
+        if not mit_license and not no_existing_header:
+            return "No MIT license"
+        if not copyrights:
+            copyrights = find_related_copyrights(filename)
+            if not copyrights:
+                copyrights.append(
+                    f"// SPDX-FileCopyrightText: Copyright (c) 2024 Adafruit Industries LLC"
+                )
+
+        if change:
+            with open(filename, "w") as f:
+                f.write(
+                    "// This file is part of the CircuitPython project: https://circuitpython.org\n//\n"
+                )
+                for copyright in copyrights:
+                    f.write(copyright)
+                    f.write("\n")
+                f.write("//\n// SPDX-License-Identifier: MIT\n")
+
+                # Copy the rest of the file.
+                for line in lines:
+                    f.write(line)
+        return None
+
+
+@click.command()
+@click.option("--change/--no-change", default=False, help="update the file, or only do a dry run")
+@click.argument("files", type=click.Path(exists=True, dir_okay=False, writable=True), nargs=-1)
+def main(change, files):
+    if not change:
+        print("Dry-run only. No changes being made. Use --change to change files")
+    for filename in files:
+        print(filename, end="")
+        error = fix_file(filename, change)
+        if error:
+            print(" :", error)
+        else:
+            print()
+
+
+if __name__ == "__main__":
+    main()