tor/scripts/maint/rename_c_identifier.py

268 lines
7.9 KiB
Python
Raw Normal View History

#!/usr/bin/env python3
#
# Copyright (c) 2001 Matej Pfajfar.
# Copyright (c) 2001-2004, Roger Dingledine.
# Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
# Copyright (c) 2007-2019, The Tor Project, Inc.
# See LICENSE for licensing information
"""
Helpful script to replace one or more C identifiers, and optionally
generate a commit message explaining what happened.
"""
# Future imports for Python 2.7, mandatory in 3.0
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
import argparse
import fileinput
import os
import re
import shlex
import subprocess
import sys
import tempfile
TOPDIR = "src"
def is_c_file(fn):
"""
Return true iff fn is the name of a C file.
>>> is_c_file("a/b/module.c")
True
>>> is_c_file("a/b/module.h")
True
>>> is_c_file("a/b/module.c~")
False
>>> is_c_file("a/b/.module.c")
False
>>> is_c_file("a/b/module.cpp")
False
"""
fn = os.path.split(fn)[1]
# Avoid editor temporary files
if fn.startswith(".") or fn.startswith("#"):
return False
ext = os.path.splitext(fn)[1]
return ext in {".c", ".h", ".i", ".inc"}
def list_c_files(topdir=TOPDIR):
"""
Use git to list all the C files under version control.
>>> lst = list(list_c_files())
>>> "src/core/mainloop/mainloop.c" in lst
True
>>> "src/core/mainloop/twiddledeedoo.c" in lst
False
>>> "micro-revision.i" in lst
False
"""
proc = subprocess.Popen(
["git", "ls-tree", "--name-only", "-r", "HEAD", topdir],
stdout=subprocess.PIPE,
encoding="utf-8")
for line in proc.stdout.readlines():
line = line.strip()
if is_c_file(line):
yield line
class Rewriter:
"""
A rewriter applies a series of word-by-word replacements, in
sequence. Replacements only happen at "word boundaries",
as determined by the \\b regular expression marker.
("A word is defined as a sequence of alphanumeric or underscore
characters", according to the documentation.)
>>> R = Rewriter([("magic", "secret"), ("words", "codes")])
>>> R.apply("The magic words are rambunctious bluejay")
'The secret codes are rambunctious bluejay'
>>> R.apply("The magical words are rambunctious bluejay")
'The magical codes are rambunctious bluejay'
>>> R.get_count()
3
"""
def __init__(self, replacements):
"""Make a new Rewriter. Takes a sequence of pairs of
(from_id, to_id), where from_id is an identifier to replace,
and to_id is its replacement.
"""
self._patterns = []
for id1, id2 in replacements:
pat = re.compile(r"\b{}\b".format(re.escape(id1)))
self._patterns.append((pat, id2))
self._count = 0
def apply(self, line):
"""Return `line` as transformed by this rewriter."""
for pat, ident in self._patterns:
line, count = pat.subn(ident, line)
self._count += count
return line
def get_count(self):
"""Return the number of identifiers that this rewriter has
rewritten."""
return self._count
def rewrite_files(files, rewriter):
"""
Apply `rewriter` to every file in `files`, replacing those files
with their rewritten contents.
"""
for line in fileinput.input(files, inplace=True):
sys.stdout.write(rewriter.apply(line))
def make_commit_msg(pairs, no_verify):
"""Return a commit message to explain what was replaced by the provided
arguments.
"""
script = ["./scripts/maint/rename_c_identifier.py"]
for id1, id2 in pairs:
qid1 = shlex.quote(id1)
qid2 = shlex.quote(id2)
script.append(" {} {}".format(qid1, qid2))
script = " \\\n".join(script)
if len(pairs) == 1:
line1 = "Rename {} to {}".format(*pairs[0])
else:
line1 = "Replace several C identifiers."
msg = """\
{}
This is an automated commit, generated by this command:
{}
""".format(line1, script)
if no_verify:
msg += """
It was generated with --no-verify, so it probably breaks some commit hooks.
The committer should be sure to fix them up in a subsequent commit.
"""
return msg
def commit(pairs, no_verify=False):
"""Try to commit the current git state, generating the commit message as
appropriate. If `no_verify` is True, pass the --no-verify argument to
git commit.
"""
args = []
if no_verify:
args.append("--no-verify")
# We have to use a try block to delete the temporary file here, since we
# are using tempfile with delete=False. We have to use delete=False,
# since otherwise we are not guaranteed to be able to give the file to
# git for it to open.
fname = None
try:
with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
fname = f.name
f.write(make_commit_msg(pairs, no_verify))
s = subprocess.run(["git", "commit", "-a", "-F", fname, "--edit"]+args)
if s.returncode != 0 and not no_verify:
print('"git commit" failed. Maybe retry with --no-verify?',
file=sys.stderr)
revert_changes()
return False
finally:
os.unlink(fname)
return True
def any_uncommitted_changes():
"""Return True if git says there are any uncommitted changes in the current
working tree; false otherwise.
"""
s = subprocess.run(["git", "diff-index", "--quiet", "HEAD"])
return s.returncode != 0
DESC = "Replace one identifier with another throughout our source."
EXAMPLES = """\
Examples:
rename_c_identifier.py set_ctrl_id set_controller_id
(Replaces every occurrence of "set_ctrl_id" with "set_controller_id".)
rename_c_identifier.py --commit set_ctrl_id set_controller_id
(As above, but also generate a git commit with an appropriate message.)
rename_c_identifier.py a b c d
(Replace "a" with "b", and "c" with "d".)"""
def revert_changes():
"""Tell git to revert all the changes in the current working tree.
"""
print('Reverting changes.', file=sys.stderr)
subprocess.run(["git", "checkout", "--quiet", TOPDIR])
def main(argv):
import argparse
parser = argparse.ArgumentParser(description=DESC, epilog=EXAMPLES,
# prevent re-wrapping the examples
formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument("--commit", action='store_true',
help="Generate a Git commit.")
parser.add_argument("--no-verify", action='store_true',
help="Tell Git not to run its pre-commit hooks.")
parser.add_argument("from_id", type=str, help="Original identifier")
parser.add_argument("to_id", type=str, help="New identifier")
parser.add_argument("more", type=str, nargs=argparse.REMAINDER,
help="Additional identifier pairs")
args = parser.parse_args(argv[1:])
if len(args.more) % 2 != 0:
print("I require an even number of identifiers.", file=sys.stderr)
return 1
if args.commit and any_uncommitted_changes():
print("Uncommitted changes found. Not running.", file=sys.stderr)
return 1
pairs = []
print("renaming {} to {}".format(args.from_id, args.to_id), file=sys.stderr)
pairs.append((args.from_id, args.to_id))
for idx in range(0, len(args.more), 2):
id1 = args.more[idx]
id2 = args.more[idx+1]
print("renaming {} to {}".format(id1, id2))
pairs.append((id1, id2))
rewriter = Rewriter(pairs)
rewrite_files(list_c_files(), rewriter)
print("Replaced {} identifiers".format(rewriter.get_count()),
file=sys.stderr)
if args.commit:
commit(pairs, args.no_verify)
if __name__ == '__main__':
main(sys.argv)