Mercurial > hg
view contrib/byteify-strings.py @ 41307:e8273eaa0726 stable
ui: inline _writenobuf() into write() due to performance issue
I'll remove redundant conditions later in this series.
author | Yuya Nishihara <yuya@tcha.org> |
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date | Thu, 24 Jan 2019 21:35:55 +0900 |
parents | da130c5cef90 |
children | 970aaf38c3fc |
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#!/usr/bin/env python3 # # 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 import argparse import contextlib import errno import os import sys import tempfile import token import tokenize 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)) 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() # 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 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 '('. """ 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 return None def _ensuresysstr(j): """Make sure the token at j is a system string Remember the given token so the string transformer won't add the byte prefix. Ignores tokens that are not strings. Assumes bounds checking has already been done. """ st = tokens[j] if st.type == token.STRING and st.string.startswith(("'", '"')): sysstrtokens.add(st) 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 # 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() # 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 # 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 ("'''", '"""'): yield adjusttokenpos(t, coloffset) continue # 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) continue # String literal. Prefix to make a b'' string. yield adjusttokenpos(t._replace(string='b%s' % t.string), coloffset) coldelta += 1 continue # 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) # .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) # 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 # Looks like "if __name__ == '__main__'". if (t.type == token.NAME and t.string == '__name__' and _isop(i + 1, '==')): _ensuresysstr(i + 2) # Emit unmodified token. yield adjusttokenpos(t, coloffset) def process(fin, fout, opts): tokens = tokenize.tokenize(fin.readline) tokens = replacetokens(list(tokens), opts) fout.write(tokenize.untokenize(tokens)) 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) def main(): ap = argparse.ArgumentParser() ap.add_argument('-i', '--inplace', action='store_true', default=False, help='edit files in place') ap.add_argument('--dictiter', action='store_true', default=False, help='rewrite iteritems() and itervalues()'), ap.add_argument('files', metavar='FILE', nargs='+', help='source file') args = ap.parse_args() opts = { 'dictiter': args.dictiter, } for fname in args.files: if args.inplace: with editinplace(fname) as fout: with open(fname, 'rb') as fin: process(fin, fout, opts) else: with open(fname, 'rb') as fin: fout = sys.stdout.buffer process(fin, fout, opts) if __name__ == '__main__': main()