Mercurial > hg
view hgext/win32mbcs.py @ 20742:3681de20b0a7
parsers: fail fast if Python has wrong minor version (issue4110)
This change causes an informative ImportError to be raised when importing
the parsers extension module if the minor version of the currently-running
Python interpreter doesn't match that of the Python used when compiling
the extension module.
This change also exposes a parsers.versionerrortext constant in the
C implementation of the module. Its presence can be used to determine
whether this behavior is present in a version of the module. The value
of the constant is the leading text of the ImportError raised and is set
to "Python minor version mismatch".
Here is an example of what the new error looks like:
Traceback (most recent call last):
File "test.py", line 1, in <module>
import mercurial.parsers
ImportError: Python minor version mismatch: The Mercurial extension
modules were compiled with Python 2.7.6, but Mercurial is currently using
Python with sys.hexversion=33883888: Python 2.5.6
(r256:88840, Nov 18 2012, 05:37:10)
[GCC 4.2.1 Compatible Apple Clang 4.1 ((tags/Apple/clang-421.11.66))]
at: /opt/local/Library/Frameworks/Python.framework/Versions/2.5/Resources/
Python.app/Contents/MacOS/Python
The reason for raising an error in this scenario is that Python's C API
is known not to be compatible from minor version to minor version, even
if sys.api_version is the same. See for example this Python bug report
about incompatibilities between 2.5 and 2.6+:
http://bugs.python.org/issue8118
These incompatibilities can cause Mercurial to break in mysterious,
unforeseen ways. For example, when Mercurial compiled with Python 2.7 was
run with 2.5, the following crash occurred when running "hg status":
http://bz.selenic.com/show_bug.cgi?id=4110
After this crash was fixed, running with Python 2.5 no longer crashes, but
the following puzzling behavior still occurs:
$ hg status
...
File ".../mercurial/changelog.py", line 123, in __init__
revlog.revlog.__init__(self, opener, "00changelog.i")
File ".../mercurial/revlog.py", line 251, in __init__
d = self._io.parseindex(i, self._inline)
File ".../mercurial/revlog.py", line 158, in parseindex
index, cache = parsers.parse_index2(data, inline)
TypeError: data is not a string
which can be reproduced more simply with:
import mercurial.parsers as parsers
parsers.parse_index2("", True)
Both the crash and the TypeError occurred because the Python C API's
PyString_Check() returns the wrong value when the C header files from
Python 2.7 are run with Python 2.5. This is an example of an
incompatibility of the sort mentioned in the Python bug report above.
Failing fast with an informative error message results in a better user
experience in cases like the above. The information in the ImportError
also simplifies troubleshooting for those on Mercurial mailing lists, the
bug tracker, etc.
This patch only adds the version check to parsers.c, which is sufficient
to affect command-line commands like "hg status" and "hg summary".
An idea for a future improvement is to move the version-checking C code
to a more central location, and have it run when importing all
Mercurial extension modules and not just parsers.c.
author | Chris Jerdonek <chris.jerdonek@gmail.com> |
---|---|
date | Wed, 04 Dec 2013 20:38:27 -0800 |
parents | 41c06a02814e |
children | 80c5b2666a96 |
line wrap: on
line source
# win32mbcs.py -- MBCS filename support for Mercurial # # Copyright (c) 2008 Shun-ichi Goto <shunichi.goto@gmail.com> # # Version: 0.3 # Author: Shun-ichi Goto <shunichi.goto@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. # '''allow the use of MBCS paths with problematic encodings Some MBCS encodings are not good for some path operations (i.e. splitting path, case conversion, etc.) with its encoded bytes. We call such a encoding (i.e. shift_jis and big5) as "problematic encoding". This extension can be used to fix the issue with those encodings by wrapping some functions to convert to Unicode string before path operation. This extension is useful for: - Japanese Windows users using shift_jis encoding. - Chinese Windows users using big5 encoding. - All users who use a repository with one of problematic encodings on case-insensitive file system. This extension is not needed for: - Any user who use only ASCII chars in path. - Any user who do not use any of problematic encodings. Note that there are some limitations on using this extension: - You should use single encoding in one repository. - If the repository path ends with 0x5c, .hg/hgrc cannot be read. - win32mbcs is not compatible with fixutf8 extension. By default, win32mbcs uses encoding.encoding decided by Mercurial. You can specify the encoding by config option:: [win32mbcs] encoding = sjis It is useful for the users who want to commit with UTF-8 log message. ''' import os, sys from mercurial.i18n import _ from mercurial import util, encoding testedwith = 'internal' _encoding = None # see extsetup def decode(arg): if isinstance(arg, str): uarg = arg.decode(_encoding) if arg == uarg.encode(_encoding): return uarg raise UnicodeError("Not local encoding") elif isinstance(arg, tuple): return tuple(map(decode, arg)) elif isinstance(arg, list): return map(decode, arg) elif isinstance(arg, dict): for k, v in arg.items(): arg[k] = decode(v) return arg def encode(arg): if isinstance(arg, unicode): return arg.encode(_encoding) elif isinstance(arg, tuple): return tuple(map(encode, arg)) elif isinstance(arg, list): return map(encode, arg) elif isinstance(arg, dict): for k, v in arg.items(): arg[k] = encode(v) return arg def appendsep(s): # ensure the path ends with os.sep, appending it if necessary. try: us = decode(s) except UnicodeError: us = s if us and us[-1] not in ':/\\': s += os.sep return s def basewrapper(func, argtype, enc, dec, args, kwds): # check check already converted, then call original for arg in args: if isinstance(arg, argtype): return func(*args, **kwds) try: # convert string arguments, call func, then convert back the # return value. return enc(func(*dec(args), **dec(kwds))) except UnicodeError: raise util.Abort(_("[win32mbcs] filename conversion failed with" " %s encoding\n") % (_encoding)) def wrapper(func, args, kwds): return basewrapper(func, unicode, encode, decode, args, kwds) def reversewrapper(func, args, kwds): return basewrapper(func, str, decode, encode, args, kwds) def wrapperforlistdir(func, args, kwds): # Ensure 'path' argument ends with os.sep to avoids # misinterpreting last 0x5c of MBCS 2nd byte as path separator. if args: args = list(args) args[0] = appendsep(args[0]) if 'path' in kwds: kwds['path'] = appendsep(kwds['path']) return func(*args, **kwds) def wrapname(name, wrapper): module, name = name.rsplit('.', 1) module = sys.modules[module] func = getattr(module, name) def f(*args, **kwds): return wrapper(func, args, kwds) try: f.__name__ = func.__name__ # fails with Python 2.3 except Exception: pass setattr(module, name, f) # List of functions to be wrapped. # NOTE: os.path.dirname() and os.path.basename() are safe because # they use result of os.path.split() funcs = '''os.path.join os.path.split os.path.splitext os.path.normpath os.makedirs mercurial.util.endswithsep mercurial.util.splitpath mercurial.util.checkcase mercurial.util.fspath mercurial.util.pconvert mercurial.util.normpath mercurial.util.checkwinfilename mercurial.util.checkosfilename mercurial.util.split''' # These functions are required to be called with local encoded string # because they expects argument is local encoded string and cause # problem with unicode string. rfuncs = '''mercurial.encoding.upper mercurial.encoding.lower''' # List of Windows specific functions to be wrapped. winfuncs = '''os.path.splitunc''' # codec and alias names of sjis and big5 to be faked. problematic_encodings = '''big5 big5-tw csbig5 big5hkscs big5-hkscs hkscs cp932 932 ms932 mskanji ms-kanji shift_jis csshiftjis shiftjis sjis s_jis shift_jis_2004 shiftjis2004 sjis_2004 sjis2004 shift_jisx0213 shiftjisx0213 sjisx0213 s_jisx0213 950 cp950 ms950 ''' def extsetup(ui): # TODO: decide use of config section for this extension if ((not os.path.supports_unicode_filenames) and (sys.platform != 'cygwin')): ui.warn(_("[win32mbcs] cannot activate on this platform.\n")) return # determine encoding for filename global _encoding _encoding = ui.config('win32mbcs', 'encoding', encoding.encoding) # fake is only for relevant environment. if _encoding.lower() in problematic_encodings.split(): for f in funcs.split(): wrapname(f, wrapper) if os.name == 'nt': for f in winfuncs.split(): wrapname(f, wrapper) wrapname("mercurial.osutil.listdir", wrapperforlistdir) # wrap functions to be called with local byte string arguments for f in rfuncs.split(): wrapname(f, reversewrapper) # Check sys.args manually instead of using ui.debug() because # command line options is not yet applied when # extensions.loadall() is called. if '--debug' in sys.argv: ui.write("[win32mbcs] activated with encoding: %s\n" % _encoding)