debian: support building a single deb for multiple py3 versions
Around transitions from one python minor version to another (such as 3.7 to
3.8), the current packaging can be slightly problematic - it produces a
`control` file that requires that the version of `python3` that's installed be
exactly the one that was used on the build machine for the `mercurial` package,
by containing a line like:
Depends: sensible-utils, libc6 (>= 2.14), python3 (<< 3.8), python3 (>= 3.7~), python3:any (>= 3.5~)
This is because it "knows" we only built for v3.7, which is the current default
on my system. By building the native components for multiple versions, we can
make it produce a line like this, which is compatible with 3.7 AND 3.8:
Depends: sensible-utils, libc6 (>= 2.14), python3 (<< 3.9), python3 (>= 3.7~), python3:any (>= 3.5~)
This isn't *normally* required, so I'm not making it the default. For those that
receive their python3 and mercurial packages from their distro, and/or don't
have to worry about a situation where the team that manages the python3
installation isn't the same as the team that manages the mercurial installation,
this is probably not necessary.
I chose the names `DEB_HG_*` because `DEB_*` is passed through `debuild`
automatically (otherwise we'd have to explicitly allow the options through,
which is a nuisance), and the `HG` part is to make it clear that this isn't a
"standard" debian option that other packages might respect.
Test Plan:
1. "nothing changed":
- built a deb without these changes
- built a deb with these changes but everything at the default
- used diffoscope to compare, all differences were due to timestamps
2. "explicit is the same as implicit" (single version)
- built a deb with everything at the default
- built a deb with DEB_HG_PYTHON_VERSIONS=3.7
- used diffoscope to compare, all differences were due to timestamps
3. "explicit is the same as implicit" (multi version)
- built a deb with DEB_HG_MULTI_VERSION=1
- built a deb with DEB_HG_PYTHON_VERSIONS=3.7
- used diffoscope to compare, all differences were due to timestamps
4. (single version, 3.7) doesn't work with python3.8
- `/usr/bin/python3.7 /usr/bin/hg debuginstall` works
- `/usr/bin/python3.8 /usr/bin/hg debuginstall` crashes
5. (multi version, 3.7 + 3.8)
- `/usr/bin/python3.7 /usr/bin/hg debuginstall` works
- `/usr/bin/python3.8 /usr/bin/hg debuginstall` works
Differential Revision: https://phab.mercurial-scm.org/D8642
# pycompat.py - portability shim for python 3
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Mercurial portability shim for python 3.
This contains aliases to hide python version-specific details from the core.
"""
from __future__ import absolute_import
import getopt
import inspect
import json
import locale
import os
import shlex
import sys
import tempfile
ispy3 = sys.version_info[0] >= 3
ispypy = '__pypy__' in sys.builtin_module_names
TYPE_CHECKING = False
if not globals(): # hide this from non-pytype users
import typing
TYPE_CHECKING = typing.TYPE_CHECKING
if not ispy3:
import cookielib
import cPickle as pickle
import httplib
import Queue as queue
import SocketServer as socketserver
import xmlrpclib
from .thirdparty.concurrent import futures
def future_set_exception_info(f, exc_info):
f.set_exception_info(*exc_info)
else:
import concurrent.futures as futures
import http.cookiejar as cookielib
import http.client as httplib
import pickle
import queue as queue
import socketserver
import xmlrpc.client as xmlrpclib
def future_set_exception_info(f, exc_info):
f.set_exception(exc_info[0])
def identity(a):
return a
def _rapply(f, xs):
if xs is None:
# assume None means non-value of optional data
return xs
if isinstance(xs, (list, set, tuple)):
return type(xs)(_rapply(f, x) for x in xs)
if isinstance(xs, dict):
return type(xs)((_rapply(f, k), _rapply(f, v)) for k, v in xs.items())
return f(xs)
def rapply(f, xs):
"""Apply function recursively to every item preserving the data structure
>>> def f(x):
... return 'f(%s)' % x
>>> rapply(f, None) is None
True
>>> rapply(f, 'a')
'f(a)'
>>> rapply(f, {'a'}) == {'f(a)'}
True
>>> rapply(f, ['a', 'b', None, {'c': 'd'}, []])
['f(a)', 'f(b)', None, {'f(c)': 'f(d)'}, []]
>>> xs = [object()]
>>> rapply(identity, xs) is xs
True
"""
if f is identity:
# fast path mainly for py2
return xs
return _rapply(f, xs)
# Passing the '' locale means that the locale should be set according to the
# user settings (environment variables).
# Python sometimes avoids setting the global locale settings. When interfacing
# with C code (e.g. the curses module or the Subversion bindings), the global
# locale settings must be initialized correctly. Python 2 does not initialize
# the global locale settings on interpreter startup. Python 3 sometimes
# initializes LC_CTYPE, but not consistently at least on Windows. Therefore we
# explicitly initialize it to get consistent behavior if it's not already
# initialized. Since CPython commit 177d921c8c03d30daa32994362023f777624b10d,
# LC_CTYPE is always initialized. If we require Python 3.8+, we should re-check
# if we can remove this code.
if locale.setlocale(locale.LC_CTYPE, None) == 'C':
try:
locale.setlocale(locale.LC_CTYPE, '')
except locale.Error:
# The likely case is that the locale from the environment variables is
# unknown.
pass
if ispy3:
import builtins
import codecs
import functools
import io
import struct
if os.name == r'nt' and sys.version_info >= (3, 6):
# MBCS (or ANSI) filesystem encoding must be used as before.
# Otherwise non-ASCII filenames in existing repositories would be
# corrupted.
# This must be set once prior to any fsencode/fsdecode calls.
sys._enablelegacywindowsfsencoding() # pytype: disable=module-attr
fsencode = os.fsencode
fsdecode = os.fsdecode
oscurdir = os.curdir.encode('ascii')
oslinesep = os.linesep.encode('ascii')
osname = os.name.encode('ascii')
ospathsep = os.pathsep.encode('ascii')
ospardir = os.pardir.encode('ascii')
ossep = os.sep.encode('ascii')
osaltsep = os.altsep
if osaltsep:
osaltsep = osaltsep.encode('ascii')
osdevnull = os.devnull.encode('ascii')
sysplatform = sys.platform.encode('ascii')
sysexecutable = sys.executable
if sysexecutable:
sysexecutable = os.fsencode(sysexecutable)
bytesio = io.BytesIO
# TODO deprecate stringio name, as it is a lie on Python 3.
stringio = bytesio
def maplist(*args):
return list(map(*args))
def rangelist(*args):
return list(range(*args))
def ziplist(*args):
return list(zip(*args))
rawinput = input
getargspec = inspect.getfullargspec
long = int
# Warning: sys.stdout.buffer and sys.stderr.buffer do not necessarily have
# the same buffering behavior as sys.stdout and sys.stderr. The interpreter
# initializes them with block-buffered streams or unbuffered streams (when
# the -u option or the PYTHONUNBUFFERED environment variable is set), never
# with a line-buffered stream.
# TODO: .buffer might not exist if std streams were replaced; we'll need
# a silly wrapper to make a bytes stream backed by a unicode one.
stdin = sys.stdin.buffer
stdout = sys.stdout.buffer
stderr = sys.stderr.buffer
if getattr(sys, 'argv', None) is not None:
# On POSIX, the char** argv array is converted to Python str using
# Py_DecodeLocale(). The inverse of this is Py_EncodeLocale(), which
# isn't directly callable from Python code. In practice, os.fsencode()
# can be used instead (this is recommended by Python's documentation
# for sys.argv).
#
# On Windows, the wchar_t **argv is passed into the interpreter as-is.
# Like POSIX, we need to emulate what Py_EncodeLocale() would do. But
# there's an additional wrinkle. What we really want to access is the
# ANSI codepage representation of the arguments, as this is what
# `int main()` would receive if Python 3 didn't define `int wmain()`
# (this is how Python 2 worked). To get that, we encode with the mbcs
# encoding, which will pass CP_ACP to the underlying Windows API to
# produce bytes.
if os.name == r'nt':
sysargv = [a.encode("mbcs", "ignore") for a in sys.argv]
else:
sysargv = [fsencode(a) for a in sys.argv]
bytechr = struct.Struct('>B').pack
byterepr = b'%r'.__mod__
class bytestr(bytes):
"""A bytes which mostly acts as a Python 2 str
>>> bytestr(), bytestr(bytearray(b'foo')), bytestr(u'ascii'), bytestr(1)
('', 'foo', 'ascii', '1')
>>> s = bytestr(b'foo')
>>> assert s is bytestr(s)
__bytes__() should be called if provided:
>>> class bytesable(object):
... def __bytes__(self):
... return b'bytes'
>>> bytestr(bytesable())
'bytes'
There's no implicit conversion from non-ascii str as its encoding is
unknown:
>>> bytestr(chr(0x80)) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
UnicodeEncodeError: ...
Comparison between bytestr and bytes should work:
>>> assert bytestr(b'foo') == b'foo'
>>> assert b'foo' == bytestr(b'foo')
>>> assert b'f' in bytestr(b'foo')
>>> assert bytestr(b'f') in b'foo'
Sliced elements should be bytes, not integer:
>>> s[1], s[:2]
(b'o', b'fo')
>>> list(s), list(reversed(s))
([b'f', b'o', b'o'], [b'o', b'o', b'f'])
As bytestr type isn't propagated across operations, you need to cast
bytes to bytestr explicitly:
>>> s = bytestr(b'foo').upper()
>>> t = bytestr(s)
>>> s[0], t[0]
(70, b'F')
Be careful to not pass a bytestr object to a function which expects
bytearray-like behavior.
>>> t = bytes(t) # cast to bytes
>>> assert type(t) is bytes
"""
def __new__(cls, s=b''):
if isinstance(s, bytestr):
return s
if not isinstance(
s, (bytes, bytearray)
) and not hasattr( # hasattr-py3-only
s, u'__bytes__'
):
s = str(s).encode('ascii')
return bytes.__new__(cls, s)
def __getitem__(self, key):
s = bytes.__getitem__(self, key)
if not isinstance(s, bytes):
s = bytechr(s)
return s
def __iter__(self):
return iterbytestr(bytes.__iter__(self))
def __repr__(self):
return bytes.__repr__(self)[1:] # drop b''
def iterbytestr(s):
"""Iterate bytes as if it were a str object of Python 2"""
return map(bytechr, s)
def maybebytestr(s):
"""Promote bytes to bytestr"""
if isinstance(s, bytes):
return bytestr(s)
return s
def sysbytes(s):
"""Convert an internal str (e.g. keyword, __doc__) back to bytes
This never raises UnicodeEncodeError, but only ASCII characters
can be round-trip by sysstr(sysbytes(s)).
"""
if isinstance(s, bytes):
return s
return s.encode('utf-8')
def sysstr(s):
"""Return a keyword str to be passed to Python functions such as
getattr() and str.encode()
This never raises UnicodeDecodeError. Non-ascii characters are
considered invalid and mapped to arbitrary but unique code points
such that 'sysstr(a) != sysstr(b)' for all 'a != b'.
"""
if isinstance(s, builtins.str):
return s
return s.decode('latin-1')
def strurl(url):
"""Converts a bytes url back to str"""
if isinstance(url, bytes):
return url.decode('ascii')
return url
def bytesurl(url):
"""Converts a str url to bytes by encoding in ascii"""
if isinstance(url, str):
return url.encode('ascii')
return url
def raisewithtb(exc, tb):
"""Raise exception with the given traceback"""
raise exc.with_traceback(tb)
def getdoc(obj):
"""Get docstring as bytes; may be None so gettext() won't confuse it
with _('')"""
doc = getattr(obj, '__doc__', None)
if doc is None:
return doc
return sysbytes(doc)
def _wrapattrfunc(f):
@functools.wraps(f)
def w(object, name, *args):
return f(object, sysstr(name), *args)
return w
# these wrappers are automagically imported by hgloader
delattr = _wrapattrfunc(builtins.delattr)
getattr = _wrapattrfunc(builtins.getattr)
hasattr = _wrapattrfunc(builtins.hasattr)
setattr = _wrapattrfunc(builtins.setattr)
xrange = builtins.range
unicode = str
def open(name, mode=b'r', buffering=-1, encoding=None):
return builtins.open(name, sysstr(mode), buffering, encoding)
safehasattr = _wrapattrfunc(builtins.hasattr)
def _getoptbwrapper(orig, args, shortlist, namelist):
"""
Takes bytes arguments, converts them to unicode, pass them to
getopt.getopt(), convert the returned values back to bytes and then
return them for Python 3 compatibility as getopt.getopt() don't accepts
bytes on Python 3.
"""
args = [a.decode('latin-1') for a in args]
shortlist = shortlist.decode('latin-1')
namelist = [a.decode('latin-1') for a in namelist]
opts, args = orig(args, shortlist, namelist)
opts = [(a[0].encode('latin-1'), a[1].encode('latin-1')) for a in opts]
args = [a.encode('latin-1') for a in args]
return opts, args
def strkwargs(dic):
"""
Converts the keys of a python dictonary to str i.e. unicodes so that
they can be passed as keyword arguments as dictonaries with bytes keys
can't be passed as keyword arguments to functions on Python 3.
"""
dic = {k.decode('latin-1'): v for k, v in dic.items()}
return dic
def byteskwargs(dic):
"""
Converts keys of python dictonaries to bytes as they were converted to
str to pass that dictonary as a keyword argument on Python 3.
"""
dic = {k.encode('latin-1'): v for k, v in dic.items()}
return dic
# TODO: handle shlex.shlex().
def shlexsplit(s, comments=False, posix=True):
"""
Takes bytes argument, convert it to str i.e. unicodes, pass that into
shlex.split(), convert the returned value to bytes and return that for
Python 3 compatibility as shelx.split() don't accept bytes on Python 3.
"""
ret = shlex.split(s.decode('latin-1'), comments, posix)
return [a.encode('latin-1') for a in ret]
iteritems = lambda x: x.items()
itervalues = lambda x: x.values()
# Python 3.5's json.load and json.loads require str. We polyfill its
# code for detecting encoding from bytes.
if sys.version_info[0:2] < (3, 6):
def _detect_encoding(b):
bstartswith = b.startswith
if bstartswith((codecs.BOM_UTF32_BE, codecs.BOM_UTF32_LE)):
return 'utf-32'
if bstartswith((codecs.BOM_UTF16_BE, codecs.BOM_UTF16_LE)):
return 'utf-16'
if bstartswith(codecs.BOM_UTF8):
return 'utf-8-sig'
if len(b) >= 4:
if not b[0]:
# 00 00 -- -- - utf-32-be
# 00 XX -- -- - utf-16-be
return 'utf-16-be' if b[1] else 'utf-32-be'
if not b[1]:
# XX 00 00 00 - utf-32-le
# XX 00 00 XX - utf-16-le
# XX 00 XX -- - utf-16-le
return 'utf-16-le' if b[2] or b[3] else 'utf-32-le'
elif len(b) == 2:
if not b[0]:
# 00 XX - utf-16-be
return 'utf-16-be'
if not b[1]:
# XX 00 - utf-16-le
return 'utf-16-le'
# default
return 'utf-8'
def json_loads(s, *args, **kwargs):
if isinstance(s, (bytes, bytearray)):
s = s.decode(_detect_encoding(s), 'surrogatepass')
return json.loads(s, *args, **kwargs)
else:
json_loads = json.loads
else:
import cStringIO
xrange = xrange
unicode = unicode
bytechr = chr
byterepr = repr
bytestr = str
iterbytestr = iter
maybebytestr = identity
sysbytes = identity
sysstr = identity
strurl = identity
bytesurl = identity
open = open
delattr = delattr
getattr = getattr
hasattr = hasattr
setattr = setattr
# this can't be parsed on Python 3
exec(b'def raisewithtb(exc, tb):\n raise exc, None, tb\n')
def fsencode(filename):
"""
Partial backport from os.py in Python 3, which only accepts bytes.
In Python 2, our paths should only ever be bytes, a unicode path
indicates a bug.
"""
if isinstance(filename, str):
return filename
else:
raise TypeError("expect str, not %s" % type(filename).__name__)
# In Python 2, fsdecode() has a very chance to receive bytes. So it's
# better not to touch Python 2 part as it's already working fine.
fsdecode = identity
def getdoc(obj):
return getattr(obj, '__doc__', None)
_notset = object()
def safehasattr(thing, attr):
return getattr(thing, attr, _notset) is not _notset
def _getoptbwrapper(orig, args, shortlist, namelist):
return orig(args, shortlist, namelist)
strkwargs = identity
byteskwargs = identity
oscurdir = os.curdir
oslinesep = os.linesep
osname = os.name
ospathsep = os.pathsep
ospardir = os.pardir
ossep = os.sep
osaltsep = os.altsep
osdevnull = os.devnull
long = long
stdin = sys.stdin
stdout = sys.stdout
stderr = sys.stderr
if getattr(sys, 'argv', None) is not None:
sysargv = sys.argv
sysplatform = sys.platform
sysexecutable = sys.executable
shlexsplit = shlex.split
bytesio = cStringIO.StringIO
stringio = bytesio
maplist = map
rangelist = range
ziplist = zip
rawinput = raw_input
getargspec = inspect.getargspec
iteritems = lambda x: x.iteritems()
itervalues = lambda x: x.itervalues()
json_loads = json.loads
isjython = sysplatform.startswith(b'java')
isdarwin = sysplatform.startswith(b'darwin')
islinux = sysplatform.startswith(b'linux')
isposix = osname == b'posix'
iswindows = osname == b'nt'
def getoptb(args, shortlist, namelist):
return _getoptbwrapper(getopt.getopt, args, shortlist, namelist)
def gnugetoptb(args, shortlist, namelist):
return _getoptbwrapper(getopt.gnu_getopt, args, shortlist, namelist)
def mkdtemp(suffix=b'', prefix=b'tmp', dir=None):
return tempfile.mkdtemp(suffix, prefix, dir)
# text=True is not supported; use util.from/tonativeeol() instead
def mkstemp(suffix=b'', prefix=b'tmp', dir=None):
return tempfile.mkstemp(suffix, prefix, dir)
# mode must include 'b'ytes as encoding= is not supported
def namedtempfile(
mode=b'w+b', bufsize=-1, suffix=b'', prefix=b'tmp', dir=None, delete=True
):
mode = sysstr(mode)
assert 'b' in mode
return tempfile.NamedTemporaryFile(
mode, bufsize, suffix=suffix, prefix=prefix, dir=dir, delete=delete
)