ci: Move clang-format-diff.py into CI directory

There’s no point in having it in the root directory when it’s only
really used for CI. It just clutters up the root.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

.gitlab-ci/clang-format-diff.py

@@ -0,0 +1,166 @@
+#!/usr/bin/env python3
+#
+# === clang-format-diff.py - ClangFormat Diff Reformatter ---*- python -*-=== #
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+# ===---------------------------------------------------------------------=== #
+
+"""
+This script reads input from a unified diff and reformats all the changed
+lines. This is useful to reformat all the lines touched by a specific patch.
+Example usage for git/svn users:
+
+  git diff -U0 --no-color HEAD^ | clang-format-diff.py -p1 -i
+  svn diff --diff-cmd=diff -x-U0 | clang-format-diff.py -i
+
+"""
+from __future__ import absolute_import, division, print_function
+
+import argparse
+import difflib
+import re
+import subprocess
+import sys
+
+if sys.version_info.major >= 3:
+    from io import StringIO
+else:
+    from io import BytesIO as StringIO
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter
+    )
+    parser.add_argument(
+        "-i",
+        action="store_true",
+        default=False,
+        help="apply edits to files instead of displaying a " "diff",
+    )
+    parser.add_argument(
+        "-p",
+        metavar="NUM",
+        default=0,
+        help="strip the smallest prefix containing P slashes",
+    )
+    parser.add_argument(
+        "-regex",
+        metavar="PATTERN",
+        default=None,
+        help="custom pattern selecting file paths to reformat "
+        "(case sensitive, overrides -iregex)",
+    )
+    parser.add_argument(
+        "-iregex",
+        metavar="PATTERN",
+        default=r".*\.(cpp|cc|c\+\+|cxx|c|cl|h|hh|hpp|m|mm|inc"
+        r"|js|ts|proto|protodevel|java|cs)",
+        help="custom pattern selecting file paths to reformat "
+        "(case insensitive, overridden by -regex)",
+    )
+    parser.add_argument(
+        "-sort-includes",
+        action="store_true",
+        default=False,
+        help="let clang-format sort include blocks",
+    )
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        action="store_true",
+        help="be more verbose, ineffective without -i",
+    )
+    parser.add_argument(
+        "-style",
+        help="formatting style to apply (LLVM, Google, " "Chromium, Mozilla, WebKit)",
+    )
+    parser.add_argument(
+        "-binary",
+        default="clang-format",
+        help="location of binary to use for clang-format",
+    )
+    args = parser.parse_args()
+
+    # Extract changed lines for each file.
+    filename = None
+    lines_by_file = {}
+    for line in sys.stdin:
+        match = re.search(r"^\+\+\+\ (.*?/){%s}(\S*)" % args.p, line)
+        if match:
+            filename = match.group(2)
+        if filename is None:
+            continue
+
+        if args.regex is not None:
+            if not re.match("^%s$" % args.regex, filename):
+                continue
+        else:
+            if not re.match("^%s$" % args.iregex, filename, re.IGNORECASE):
+                continue
+
+        match = re.search(r"^@@.*\+(\d+)(,(\d+))?", line)
+        if match:
+            start_line = int(match.group(1))
+            line_count = 1
+            if match.group(3):
+                line_count = int(match.group(3))
+            if line_count == 0:
+                continue
+            end_line = start_line + line_count - 1
+            lines_by_file.setdefault(filename, []).extend(
+                ["-lines", str(start_line) + ":" + str(end_line)]
+            )
+
+    # Reformat files containing changes in place.
+    # We need to count amount of bytes generated in the output of
+    # clang-format-diff. If clang-format-diff doesn't generate any bytes it
+    # means there is nothing to format.
+    format_line_counter = 0
+    for filename, lines in lines_by_file.items():
+        if args.i and args.verbose:
+            print("Formatting {}".format(filename))
+        command = [args.binary, filename]
+        if args.i:
+            command.append("-i")
+        if args.sort_includes:
+            command.append("-sort-includes")
+        command.extend(lines)
+        if args.style:
+            command.extend(["-style", args.style])
+        p = subprocess.Popen(
+            command,
+            stdout=subprocess.PIPE,
+            stderr=None,
+            stdin=subprocess.PIPE,
+            universal_newlines=True,
+        )
+        stdout, _ = p.communicate()
+        if p.returncode != 0:
+            sys.exit(p.returncode)
+
+        if not args.i:
+            with open(filename) as f:
+                code = f.readlines()
+            formatted_code = StringIO(stdout).readlines()
+            diff = difflib.unified_diff(
+                code,
+                formatted_code,
+                filename,
+                filename,
+                "(before formatting)",
+                "(after formatting)",
+            )
+            diff_string = "".join(diff)
+            if diff_string:
+                format_line_counter += sys.stdout.write(diff_string)
+
+    if format_line_counter > 0:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()