clang-format-diff.py raw
1 #!/usr/bin/env python3
2 #
3 # ===- clang-format-diff.py - ClangFormat Diff Reformatter ----*- python -*--===#
4 #
5 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
6 # See https://llvm.org/LICENSE.txt for license information.
7 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
8 #
9 # ===------------------------------------------------------------------------===#
10
11 """
12 This script reads input from a unified diff and reformats all the changed
13 lines. This is useful to reformat all the lines touched by a specific patch.
14 Example usage for git/svn users:
15
16 git diff -U0 --no-color --relative HEAD^ | {clang_format_diff} -p1 -i
17 svn diff --diff-cmd=diff -x-U0 | {clang_format_diff} -i
18
19 It should be noted that the filename contained in the diff is used unmodified
20 to determine the source file to update. Users calling this script directly
21 should be careful to ensure that the path in the diff is correct relative to the
22 current working directory.
23 """
24 from __future__ import absolute_import, division, print_function
25
26 import argparse
27 import difflib
28 import re
29 import subprocess
30 import sys
31
32 from io import StringIO
33
34
35 def main():
36 parser = argparse.ArgumentParser(
37 description=__doc__.format(clang_format_diff="%(prog)s"),
38 formatter_class=argparse.RawDescriptionHelpFormatter,
39 )
40 parser.add_argument(
41 "-i",
42 action="store_true",
43 default=False,
44 help="apply edits to files instead of displaying a diff",
45 )
46 parser.add_argument(
47 "-p",
48 metavar="NUM",
49 default=0,
50 help="strip the smallest prefix containing P slashes",
51 )
52 parser.add_argument(
53 "-regex",
54 metavar="PATTERN",
55 default=None,
56 help="custom pattern selecting file paths to reformat "
57 "(case sensitive, overrides -iregex)",
58 )
59 parser.add_argument(
60 "-iregex",
61 metavar="PATTERN",
62 default=r".*\.(?:cpp|cc|c\+\+|cxx|cppm|ccm|cxxm|c\+\+m|c|cl|h|hh|hpp"
63 r"|hxx|m|mm|inc|js|ts|proto|protodevel|java|cs|json|s?vh?)",
64 help="custom pattern selecting file paths to reformat "
65 "(case insensitive, overridden by -regex)",
66 )
67 parser.add_argument(
68 "-sort-includes",
69 action="store_true",
70 default=False,
71 help="let clang-format sort include blocks",
72 )
73 parser.add_argument(
74 "-v",
75 "--verbose",
76 action="store_true",
77 help="be more verbose, ineffective without -i",
78 )
79 parser.add_argument(
80 "-style",
81 help="formatting style to apply (LLVM, GNU, Google, Chromium, "
82 "Microsoft, Mozilla, WebKit)",
83 )
84 parser.add_argument(
85 "-fallback-style",
86 help="The name of the predefined style used as a"
87 "fallback in case clang-format is invoked with"
88 "-style=file, but can not find the .clang-format"
89 "file to use.",
90 )
91 parser.add_argument(
92 "-binary",
93 default="clang-format",
94 help="location of binary to use for clang-format",
95 )
96 args = parser.parse_args()
97
98 # Extract changed lines for each file.
99 filename = None
100 lines_by_file = {}
101 for line in sys.stdin:
102 match = re.search(r"^\+\+\+\ (.*?/){%s}(\S*)" % args.p, line)
103 if match:
104 filename = match.group(2)
105 if filename is None:
106 continue
107
108 if args.regex is not None:
109 if not re.match("^%s$" % args.regex, filename):
110 continue
111 else:
112 if not re.match("^%s$" % args.iregex, filename, re.IGNORECASE):
113 continue
114
115 match = re.search(r"^@@.*\+(\d+)(?:,(\d+))?", line)
116 if match:
117 start_line = int(match.group(1))
118 line_count = 1
119 if match.group(2):
120 line_count = int(match.group(2))
121 # The input is something like
122 #
123 # @@ -1, +0,0 @@
124 #
125 # which means no lines were added.
126 if line_count == 0:
127 continue
128 # Also format lines range if line_count is 0 in case of deleting
129 # surrounding statements.
130 end_line = start_line
131 if line_count != 0:
132 end_line += line_count - 1
133 lines_by_file.setdefault(filename, []).extend(
134 ["-lines", str(start_line) + ":" + str(end_line)]
135 )
136
137 # Reformat files containing changes in place.
138 for filename, lines in lines_by_file.items():
139 if args.i and args.verbose:
140 print("Formatting {}".format(filename))
141 command = [args.binary, filename]
142 if args.i:
143 command.append("-i")
144 if args.sort_includes:
145 command.append("-sort-includes")
146 command.extend(lines)
147 if args.style:
148 command.extend(["-style", args.style])
149 if args.fallback_style:
150 command.extend(["-fallback-style", args.fallback_style])
151
152 try:
153 p = subprocess.Popen(
154 command,
155 stdout=subprocess.PIPE,
156 stderr=None,
157 stdin=subprocess.PIPE,
158 universal_newlines=True,
159 )
160 except OSError as e:
161 # Give the user more context when clang-format isn't
162 # found/isn't executable, etc.
163 raise RuntimeError(
164 'Failed to run "%s" - %s"' % (" ".join(command), e.strerror)
165 )
166
167 stdout, _stderr = p.communicate()
168 if p.returncode != 0:
169 sys.exit(p.returncode)
170
171 if not args.i:
172 with open(filename) as f:
173 code = f.readlines()
174 formatted_code = StringIO(stdout).readlines()
175 diff = difflib.unified_diff(
176 code,
177 formatted_code,
178 filename,
179 filename,
180 "(before formatting)",
181 "(after formatting)",
182 )
183 diff_string = "".join(diff)
184 if len(diff_string) > 0:
185 sys.stdout.write(diff_string)
186 sys.exit(1)
187
188
189 if __name__ == "__main__":
190 main()
191