xref: /llvm-project/clang/docs/tools/dump_format_help.py (revision c47c480b1845c27693f95d4ec8f3373898e99365)
1#!/usr/bin/env python3
2# A tool to parse the output of `clang-format --help` and update the
3# documentation in ../ClangFormat.rst automatically.
4
5import os
6import re
7import subprocess
8import sys
9
10PARENT_DIR = os.path.join(os.path.dirname(__file__), "..")
11DOC_FILE = os.path.join(PARENT_DIR, "ClangFormat.rst")
12
13
14def substitute(text, tag, contents):
15    replacement = "\n.. START_%s\n\n%s\n\n.. END_%s\n" % (tag, contents, tag)
16    pattern = r"\n\.\. START_%s\n.*\n\.\. END_%s\n" % (tag, tag)
17    return re.sub(pattern, replacement, text, flags=re.S)
18
19
20def indent(text, columns, indent_first_line=True):
21    indent_str = " " * columns
22    s = re.sub(r"\n([^\n])", "\n" + indent_str + "\\1", text, flags=re.S)
23    if not indent_first_line or s.startswith("\n"):
24        return s
25    return indent_str + s
26
27
28def get_help_output():
29    args = ["clang-format", "--help"]
30    cmd = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
31    out, _ = cmd.communicate()
32    out = out.decode(sys.stdout.encoding)
33    return out
34
35
36def get_help_text():
37    out = get_help_output()
38    out = re.sub(r" clang-format\.exe ", " clang-format ", out)
39
40    out = (
41        """.. code-block:: console
42
43$ clang-format --help
44"""
45        + out
46    )
47    out = indent(out, 2, indent_first_line=False)
48    return out
49
50
51def validate(text, columns):
52    for line in text.splitlines():
53        if len(line) > columns:
54            print("warning: line too long:\n", line, file=sys.stderr)
55
56
57help_text = get_help_text()
58validate(help_text, 100)
59
60with open(DOC_FILE) as f:
61    contents = f.read()
62
63contents = substitute(contents, "FORMAT_HELP", help_text)
64
65with open(DOC_FILE, "wb") as output:
66    output.write(contents.encode())
67