byteify-strings.py
230 lines
| 8.0 KiB
| text/x-python
|
PythonLexer
/ contrib / byteify-strings.py
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|
r38404 | #!/usr/bin/env python3 | ||
# | ||||
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r38403 | # byteify-strings.py - transform string literals to be Python 3 safe | ||
# | ||||
# Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com> | ||||
# | ||||
# This software may be used and distributed according to the terms of the | ||||
# GNU General Public License version 2 or any later version. | ||||
from __future__ import absolute_import | ||||
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r38404 | import argparse | ||
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r38405 | import contextlib | ||
import errno | ||||
import os | ||||
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r38404 | import sys | ||
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r38405 | import tempfile | ||
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r38403 | import token | ||
import tokenize | ||||
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r38409 | def adjusttokenpos(t, ofs): | ||
"""Adjust start/end column of the given token""" | ||||
return t._replace(start=(t.start[0], t.start[1] + ofs), | ||||
end=(t.end[0], t.end[1] + ofs)) | ||||
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r38410 | def replacetokens(tokens, opts): | ||
"""Transform a stream of tokens from raw to Python 3. | ||||
Returns a generator of possibly rewritten tokens. | ||||
The input token list may be mutated as part of processing. However, | ||||
its changes do not necessarily match the output token stream. | ||||
""" | ||||
sysstrtokens = set() | ||||
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r38403 | |||
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r38410 | # The following utility functions access the tokens list and i index of | ||
# the for i, t enumerate(tokens) loop below | ||||
def _isop(j, *o): | ||||
"""Assert that tokens[j] is an OP with one of the given values""" | ||||
try: | ||||
return tokens[j].type == token.OP and tokens[j].string in o | ||||
except IndexError: | ||||
return False | ||||
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r38403 | |||
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r38410 | def _findargnofcall(n): | ||
"""Find arg n of a call expression (start at 0) | ||||
Returns index of the first token of that argument, or None if | ||||
there is not that many arguments. | ||||
Assumes that token[i + 1] is '('. | ||||
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r38408 | |||
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r38410 | """ | ||
nested = 0 | ||||
for j in range(i + 2, len(tokens)): | ||||
if _isop(j, ')', ']', '}'): | ||||
# end of call, tuple, subscription or dict / set | ||||
nested -= 1 | ||||
if nested < 0: | ||||
return None | ||||
elif n == 0: | ||||
# this is the starting position of arg | ||||
return j | ||||
elif _isop(j, '(', '[', '{'): | ||||
nested += 1 | ||||
elif _isop(j, ',') and nested == 0: | ||||
n -= 1 | ||||
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r38403 | |||
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r38410 | return None | ||
def _ensuresysstr(j): | ||||
"""Make sure the token at j is a system string | ||||
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r38403 | |||
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r38410 | Remember the given token so the string transformer won't add | ||
the byte prefix. | ||||
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r38403 | |||
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r38410 | Ignores tokens that are not strings. Assumes bounds checking has | ||
already been done. | ||||
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r38403 | |||
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r38410 | """ | ||
st = tokens[j] | ||||
if st.type == token.STRING and st.string.startswith(("'", '"')): | ||||
sysstrtokens.add(st) | ||||
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r38403 | |||
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r38410 | coldelta = 0 # column increment for new opening parens | ||
coloffset = -1 # column offset for the current line (-1: TBD) | ||||
parens = [(0, 0, 0)] # stack of (line, end-column, column-offset) | ||||
for i, t in enumerate(tokens): | ||||
# Compute the column offset for the current line, such that | ||||
# the current line will be aligned to the last opening paren | ||||
# as before. | ||||
if coloffset < 0: | ||||
if t.start[1] == parens[-1][1]: | ||||
coloffset = parens[-1][2] | ||||
elif t.start[1] + 1 == parens[-1][1]: | ||||
# fix misaligned indent of s/util.Abort/error.Abort/ | ||||
coloffset = parens[-1][2] + (parens[-1][1] - t.start[1]) | ||||
else: | ||||
coloffset = 0 | ||||
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r38403 | |||
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r38410 | # Reset per-line attributes at EOL. | ||
if t.type in (token.NEWLINE, tokenize.NL): | ||||
yield adjusttokenpos(t, coloffset) | ||||
coldelta = 0 | ||||
coloffset = -1 | ||||
continue | ||||
# Remember the last paren position. | ||||
if _isop(i, '(', '[', '{'): | ||||
parens.append(t.end + (coloffset + coldelta,)) | ||||
elif _isop(i, ')', ']', '}'): | ||||
parens.pop() | ||||
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r38403 | |||
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r38410 | # Convert most string literals to byte literals. String literals | ||
# in Python 2 are bytes. String literals in Python 3 are unicode. | ||||
# Most strings in Mercurial are bytes and unicode strings are rare. | ||||
# Rather than rewrite all string literals to use ``b''`` to indicate | ||||
# byte strings, we apply this token transformer to insert the ``b`` | ||||
# prefix nearly everywhere. | ||||
if t.type == token.STRING and t not in sysstrtokens: | ||||
s = t.string | ||||
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r38409 | |||
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r38410 | # Preserve docstrings as string literals. This is inconsistent | ||
# with regular unprefixed strings. However, the | ||||
# "from __future__" parsing (which allows a module docstring to | ||||
# exist before it) doesn't properly handle the docstring if it | ||||
# is b''' prefixed, leading to a SyntaxError. We leave all | ||||
# docstrings as unprefixed to avoid this. This means Mercurial | ||||
# components touching docstrings need to handle unicode, | ||||
# unfortunately. | ||||
if s[0:3] in ("'''", '"""'): | ||||
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r38409 | yield adjusttokenpos(t, coloffset) | ||
continue | ||||
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r38410 | # If the first character isn't a quote, it is likely a string | ||
# prefixing character (such as 'b', 'u', or 'r'. Ignore. | ||||
if s[0] not in ("'", '"'): | ||||
yield adjusttokenpos(t, coloffset) | ||||
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r38403 | continue | ||
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r38410 | # String literal. Prefix to make a b'' string. | ||
yield adjusttokenpos(t._replace(string='b%s' % t.string), | ||||
coloffset) | ||||
coldelta += 1 | ||||
continue | ||||
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r38403 | |||
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r38410 | # This looks like a function call. | ||
if t.type == token.NAME and _isop(i + 1, '('): | ||||
fn = t.string | ||||
# *attr() builtins don't accept byte strings to 2nd argument. | ||||
if (fn in ('getattr', 'setattr', 'hasattr', 'safehasattr') and | ||||
not _isop(i - 1, '.')): | ||||
arg1idx = _findargnofcall(1) | ||||
if arg1idx is not None: | ||||
_ensuresysstr(arg1idx) | ||||
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r38403 | |||
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r38410 | # .encode() and .decode() on str/bytes/unicode don't accept | ||
# byte strings on Python 3. | ||||
elif fn in ('encode', 'decode') and _isop(i - 1, '.'): | ||||
for argn in range(2): | ||||
argidx = _findargnofcall(argn) | ||||
if argidx is not None: | ||||
_ensuresysstr(argidx) | ||||
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r38403 | |||
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r38410 | # It changes iteritems/values to items/values as they are not | ||
# present in Python 3 world. | ||||
elif opts['dictiter'] and fn in ('iteritems', 'itervalues'): | ||||
yield adjusttokenpos(t._replace(string=fn[4:]), coloffset) | ||||
continue | ||||
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r38403 | |||
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r39139 | # Looks like "if __name__ == '__main__'". | ||
if (t.type == token.NAME and t.string == '__name__' | ||||
and _isop(i + 1, '==')): | ||||
_ensuresysstr(i + 2) | ||||
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r38410 | # Emit unmodified token. | ||
yield adjusttokenpos(t, coloffset) | ||||
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r38404 | |||
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r38407 | def process(fin, fout, opts): | ||
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r38404 | tokens = tokenize.tokenize(fin.readline) | ||
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r38407 | tokens = replacetokens(list(tokens), opts) | ||
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r38404 | fout.write(tokenize.untokenize(tokens)) | ||
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r38405 | def tryunlink(fname): | ||
try: | ||||
os.unlink(fname) | ||||
except OSError as err: | ||||
if err.errno != errno.ENOENT: | ||||
raise | ||||
@contextlib.contextmanager | ||||
def editinplace(fname): | ||||
n = os.path.basename(fname) | ||||
d = os.path.dirname(fname) | ||||
fp = tempfile.NamedTemporaryFile(prefix='.%s-' % n, suffix='~', dir=d, | ||||
delete=False) | ||||
try: | ||||
yield fp | ||||
fp.close() | ||||
if os.name == 'nt': | ||||
tryunlink(fname) | ||||
os.rename(fp.name, fname) | ||||
finally: | ||||
fp.close() | ||||
tryunlink(fp.name) | ||||
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r38404 | def main(): | ||
ap = argparse.ArgumentParser() | ||||
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r38405 | ap.add_argument('-i', '--inplace', action='store_true', default=False, | ||
help='edit files in place') | ||||
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r38407 | ap.add_argument('--dictiter', action='store_true', default=False, | ||
help='rewrite iteritems() and itervalues()'), | ||||
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r38404 | ap.add_argument('files', metavar='FILE', nargs='+', help='source file') | ||
args = ap.parse_args() | ||||
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r38407 | opts = { | ||
'dictiter': args.dictiter, | ||||
} | ||||
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r38404 | for fname in args.files: | ||
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r38405 | if args.inplace: | ||
with editinplace(fname) as fout: | ||||
with open(fname, 'rb') as fin: | ||||
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r38407 | process(fin, fout, opts) | ||
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r38405 | else: | ||
with open(fname, 'rb') as fin: | ||||
fout = sys.stdout.buffer | ||||
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r38407 | process(fin, fout, opts) | ||
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r38404 | |||
if __name__ == '__main__': | ||||
main() | ||||