setup: create a module for the modulepolicy

Instead of rewriting __init__ to define the modulepolicy,
write out a __modulepolicy__.py file like __version__.py

This should work for both system-wide installation and in-place build. Therefore
we can avoid relying on two separate modulepolicy rules, '@MODULELOADPOLICY@'
and 'mercurial/modulepolicy'.

.hgignore

@@ -1,68 +1,69
 syntax: glob
 
 *.elc
 *.tmp
 *.orig
 *.rej
 *~
 *.mergebackup
 *.o
 *.so
 *.dll
 *.exe
 *.pyd
 *.pyc
 *.pyo
 *$py.class
 *.swp
 *.prof
 *.zip
 \#*\#
 .\#*
 tests/.coverage*
 tests/.testtimes*
 tests/.hypothesis
 tests/hypothesis-generated
 tests/annotated
 tests/*.err
 tests/htmlcov
 build
 contrib/chg/chg
 contrib/hgsh/hgsh
 contrib/vagrant/.vagrant
 dist
 packages
 doc/common.txt
 doc/*.[0-9]
 doc/*.[0-9].txt
 doc/*.[0-9].gendoc.txt
 doc/*.[0-9].{x,ht}ml
 MANIFEST
 MANIFEST.in
 patches
+mercurial/__modulepolicy__.py
 mercurial/__version__.py
 mercurial/hgpythonlib.h
 mercurial.egg-info
 .DS_Store
 tags
 cscope.*
 .idea/*
 i18n/hg.pot
 locale/*/LC_MESSAGES/hg.mo
 hgext/__index__.py
 
 # files installed with a local --pure build
 mercurial/base85.py
 mercurial/bdiff.py
 mercurial/diffhelpers.py
 mercurial/mpatch.py
 mercurial/osutil.py
 mercurial/parsers.py
 
 syntax: regexp
 ^\.pc/
 ^\.(pydev)?project
 
 # hackable windows distribution additions
 ^hg-python
 ^hg.py$

Makefile

@@ -1,226 +1,227
 # If you want to change PREFIX, do not just edit it below. The changed
 # value wont get passed on to recursive make calls. You should instead
 # override the variable on the command like:
 #
 # % make PREFIX=/opt/ install
 
 PREFIX=/usr/local
 export PREFIX
 PYTHON=python
 $(eval HGROOT := $(shell pwd))
 HGPYTHONS ?= $(HGROOT)/build/pythons
 PURE=
 PYFILES:=$(shell find mercurial hgext doc -name '*.py')
 DOCFILES=mercurial/help/*.txt
 export LANGUAGE=C
 export LC_ALL=C
 TESTFLAGS ?= $(shell echo $$HGTESTFLAGS)
 
 # Set this to e.g. "mingw32" to use a non-default compiler.
 COMPILER=
 
 help:
 	@echo 'Commonly used make targets:'
 	@echo '  all          - build program and documentation'
 	@echo '  install      - install program and man pages to $$PREFIX ($(PREFIX))'
 	@echo '  install-home - install with setup.py install --home=$$HOME ($(HOME))'
 	@echo '  local        - build for inplace usage'
 	@echo '  tests        - run all tests in the automatic test suite'
 	@echo '  test-foo     - run only specified tests (e.g. test-merge1.t)'
 	@echo '  dist         - run all tests and create a source tarball in dist/'
 	@echo '  clean        - remove files created by other targets'
 	@echo '                 (except installed files or dist source tarball)'
 	@echo '  update-pot   - update i18n/hg.pot'
 	@echo
 	@echo 'Example for a system-wide installation under /usr/local:'
 	@echo '  make all && su -c "make install" && hg version'
 	@echo
 	@echo 'Example for a local installation (usable in this directory):'
 	@echo '  make local && ./hg version'
 
 all: build doc
 
 local:
 	$(PYTHON) setup.py $(PURE) \
 	  build_py -c -d . \
 	  build_ext $(COMPILER:%=-c %) -i \
 	  build_hgexe $(COMPILER:%=-c %) -i \
 	  build_mo
 	env HGRCPATH= $(PYTHON) hg version
 
 build:
 	$(PYTHON) setup.py $(PURE) build $(COMPILER:%=-c %)
 
 wheel:
 	FORCE_SETUPTOOLS=1 $(PYTHON) setup.py $(PURE) bdist_wheel $(COMPILER:%=-c %)
 
 doc:
 	$(MAKE) -C doc
 
 clean:
 	-$(PYTHON) setup.py clean --all # ignore errors from this command
 	find contrib doc hgext i18n mercurial tests \
 		\( -name '*.py[cdo]' -o -name '*.so' \) -exec rm -f '{}' ';'
 	rm -f $(addprefix mercurial/,$(notdir $(wildcard mercurial/pure/[a-z]*.py)))
 	rm -f MANIFEST MANIFEST.in hgext/__index__.py tests/*.err
+	rm -f mercurial/__modulepolicy__.py
 	if test -d .hg; then rm -f mercurial/__version__.py; fi
 	rm -rf build mercurial/locale
 	$(MAKE) -C doc clean
 
 install: install-bin install-doc
 
 install-bin: build
 	$(PYTHON) setup.py $(PURE) install --root="$(DESTDIR)/" --prefix="$(PREFIX)" --force
 
 install-doc: doc
 	cd doc && $(MAKE) $(MFLAGS) install
 
 install-home: install-home-bin install-home-doc
 
 install-home-bin: build
 	$(PYTHON) setup.py $(PURE) install --home="$(HOME)" --prefix="" --force
 
 install-home-doc: doc
 	cd doc && $(MAKE) $(MFLAGS) PREFIX="$(HOME)" install
 
 MANIFEST-doc:
 	$(MAKE) -C doc MANIFEST
 
 MANIFEST.in: MANIFEST-doc
 	hg manifest | sed -e 's/^/include /' > MANIFEST.in
 	echo include mercurial/__version__.py >> MANIFEST.in
 	sed -e 's/^/include /' < doc/MANIFEST >> MANIFEST.in
 
 dist:	tests dist-notests
 
 dist-notests:	doc MANIFEST.in
 	TAR_OPTIONS="--owner=root --group=root --mode=u+w,go-w,a+rX-s" $(PYTHON) setup.py -q sdist
 
 check: tests
 
 tests:
 	cd tests && $(PYTHON) run-tests.py $(TESTFLAGS)
 
 test-%:
 	cd tests && $(PYTHON) run-tests.py $(TESTFLAGS) $@
 
 testpy-%:
 	@echo Looking for Python $* in $(HGPYTHONS)
 	[ -e $(HGPYTHONS)/$*/bin/python ] || ( \
 	cd $$(mktemp --directory --tmpdir) && \
         $(MAKE) -f $(HGROOT)/contrib/Makefile.python PYTHONVER=$* PREFIX=$(HGPYTHONS)/$* python )
 	cd tests && $(HGPYTHONS)/$*/bin/python run-tests.py $(TESTFLAGS)
 
 check-code:
 	hg manifest | xargs python contrib/check-code.py
 
 update-pot: i18n/hg.pot
 
 i18n/hg.pot: $(PYFILES) $(DOCFILES) i18n/posplit i18n/hggettext
 	$(PYTHON) i18n/hggettext mercurial/commands.py \
 	  hgext/*.py hgext/*/__init__.py \
 	  mercurial/fileset.py mercurial/revset.py \
 	  mercurial/templatefilters.py mercurial/templatekw.py \
 	  mercurial/templater.py \
 	  mercurial/filemerge.py \
 	  mercurial/hgweb/webcommands.py \
 	  $(DOCFILES) > i18n/hg.pot.tmp
         # All strings marked for translation in Mercurial contain
         # ASCII characters only. But some files contain string
         # literals like this '\037\213'. xgettext thinks it has to
         # parse them even though they are not marked for translation.
         # Extracting with an explicit encoding of ISO-8859-1 will make
         # xgettext "parse" and ignore them.
 	echo $(PYFILES) | xargs \
 	  xgettext --package-name "Mercurial" \
 	  --msgid-bugs-address "<[e-mail]>" \
 	  --copyright-holder "Matt Mackall <[e-mail]> and others" \
 	  --from-code ISO-8859-1 --join --sort-by-file --add-comments=i18n: \
 	  -d hg -p i18n -o hg.pot.tmp
 	$(PYTHON) i18n/posplit i18n/hg.pot.tmp
         # The target file is not created before the last step. So it never is in
         # an intermediate state.
 	mv -f i18n/hg.pot.tmp i18n/hg.pot
 
 %.po: i18n/hg.pot
         # work on a temporary copy for never having a half completed target
 	cp $@ $@.tmp
 	msgmerge --no-location --update $@.tmp $^
 	mv -f $@.tmp $@
 
 # Packaging targets
 
 osx:
 	python -c 'import bdist_mpkg.script_bdist_mpkg' || \
 	   (echo "Missing bdist_mpkg (easy_install bdist_mpkg)"; false)
 	rm -rf dist/mercurial-*.mpkg
 	python -m bdist_mpkg.script_bdist_mpkg setup.py --
 	python contrib/fixpax.py dist/mercurial-*.mpkg/Contents/Packages/*.pkg/Contents/Archive.pax.gz
 	mkdir -p packages/osx
 	N=`cd dist && echo mercurial-*.mpkg | sed 's,\.mpkg$$,,'` && hdiutil create -srcfolder dist/$$N.mpkg/ -scrub -volname "$$N" -ov packages/osx/$$N.dmg
 	rm -rf dist/mercurial-*.mpkg
 
 deb:
 	contrib/builddeb
 
 docker-debian-jessie:
 	mkdir -p packages/debian-jessie
 	contrib/dockerdeb debian jessie
 
 fedora20:
 	mkdir -p packages/fedora20
 	contrib/buildrpm
 	cp rpmbuild/RPMS/*/* packages/fedora20
 	cp rpmbuild/SRPMS/* packages/fedora20
 	rm -rf rpmbuild
 
 docker-fedora20:
 	mkdir -p packages/fedora20
 	contrib/dockerrpm fedora20
 
 fedora21:
 	mkdir -p packages/fedora21
 	contrib/buildrpm
 	cp rpmbuild/RPMS/*/* packages/fedora21
 	cp rpmbuild/SRPMS/* packages/fedora21
 	rm -rf rpmbuild
 
 docker-fedora21:
 	mkdir -p packages/fedora21
 	contrib/dockerrpm fedora21
 
 centos5:
 	mkdir -p packages/centos5
 	contrib/buildrpm --withpython
 	cp rpmbuild/RPMS/*/* packages/centos5
 	cp rpmbuild/SRPMS/* packages/centos5
 
 docker-centos5:
 	mkdir -p packages/centos5
 	contrib/dockerrpm centos5 --withpython
 
 centos6:
 	mkdir -p packages/centos6
 	contrib/buildrpm
 	cp rpmbuild/RPMS/*/* packages/centos6
 	cp rpmbuild/SRPMS/* packages/centos6
 
 docker-centos6:
 	mkdir -p packages/centos6
 	contrib/dockerrpm centos6
 
 centos7:
 	mkdir -p packages/centos7
 	contrib/buildrpm
 	cp rpmbuild/RPMS/*/* packages/centos7
 	cp rpmbuild/SRPMS/* packages/centos7
 
 docker-centos7:
 	mkdir -p packages/centos7
 	contrib/dockerrpm centos7
 
 .PHONY: help all local build doc clean install install-bin install-doc \
 	install-home install-home-bin install-home-doc \
 	dist dist-notests check tests check-code update-pot \
 	osx fedora20 docker-fedora20 fedora21 docker-fedora21 \
 	centos5 docker-centos5 centos6 docker-centos6 centos7 docker-centos7

mercurial/__init__.py

@@ -1,144 +1,147
 # __init__.py - Startup and module loading logic for Mercurial.
 #
 # Copyright 2015 Gregory Szorc <[e-mail]>
 #
 # 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 imp
 import os
 import sys
 import zipimport
 
 __all__ = []
 
 # Rules for how modules can be loaded. Values are:
 #
 #    c - require C extensions
 #    allow - allow pure Python implementation when C loading fails
 #    py - only load pure Python modules
-modulepolicy = '@MODULELOADPOLICY@'
-
+#
 # By default, require the C extensions for performance reasons.
-if modulepolicy == '@' 'MODULELOADPOLICY' '@':
     modulepolicy = 'c'
+try:
+    from . import __modulepolicy__
+    modulepolicy = __modulepolicy__.modulepolicy
+except ImportError:
+    pass
 
 # PyPy doesn't load C extensions.
 #
 # The canonical way to do this is to test platform.python_implementation().
 # But we don't import platform and don't bloat for it here.
 if '__pypy__' in sys.builtin_module_names:
     modulepolicy = 'py'
 
 # Environment variable can always force settings.
 modulepolicy = os.environ.get('HGMODULEPOLICY', modulepolicy)
 
 # Modules that have both Python and C implementations. See also the
 # set of .py files under mercurial/pure/.
 _dualmodules = set([
     'mercurial.base85',
     'mercurial.bdiff',
     'mercurial.diffhelpers',
     'mercurial.mpatch',
     'mercurial.osutil',
     'mercurial.parsers',
 ])
 
 class hgimporter(object):
     """Object that conforms to import hook interface defined in PEP-302."""
     def find_module(self, name, path=None):
         # We only care about modules that have both C and pure implementations.
         if name in _dualmodules:
             return self
         return None
 
     def load_module(self, name):
         mod = sys.modules.get(name, None)
         if mod:
             return mod
 
         mercurial = sys.modules['mercurial']
 
         # The zip importer behaves sufficiently differently from the default
         # importer to warrant its own code path.
         loader = getattr(mercurial, '__loader__', None)
         if isinstance(loader, zipimport.zipimporter):
             def ziploader(*paths):
                 """Obtain a zipimporter for a directory under the main zip."""
                 path = os.path.join(loader.archive, *paths)
                 zl = sys.path_importer_cache.get(path)
                 if not zl:
                     zl = zipimport.zipimporter(path)
                 return zl
 
             try:
                 if modulepolicy == 'py':
                     raise ImportError()
 
                 zl = ziploader('mercurial')
                 mod = zl.load_module(name)
                 # Unlike imp, ziploader doesn't expose module metadata that
                 # indicates the type of module. So just assume what we found
                 # is OK (even though it could be a pure Python module).
             except ImportError:
                 if modulepolicy == 'c':
                     raise
                 zl = ziploader('mercurial', 'pure')
                 mod = zl.load_module(name)
 
             sys.modules[name] = mod
             return mod
 
         # Unlike the default importer which searches special locations and
         # sys.path, we only look in the directory where "mercurial" was
         # imported from.
 
         # imp.find_module doesn't support submodules (modules with ".").
         # Instead you have to pass the parent package's __path__ attribute
         # as the path argument.
         stem = name.split('.')[-1]
 
         try:
             if modulepolicy == 'py':
                 raise ImportError()
 
             modinfo = imp.find_module(stem, mercurial.__path__)
 
             # The Mercurial installer used to copy files from
             # mercurial/pure/*.py to mercurial/*.py. Therefore, it's possible
             # for some installations to have .py files under mercurial/*.
             # Loading Python modules when we expected C versions could result
             # in a) poor performance b) loading a version from a previous
             # Mercurial version, potentially leading to incompatibility. Either
             # scenario is bad. So we verify that modules loaded from
             # mercurial/* are C extensions. If the current policy allows the
             # loading of .py modules, the module will be re-imported from
             # mercurial/pure/* below.
             if modinfo[2][2] != imp.C_EXTENSION:
                 raise ImportError('.py version of %s found where C '
                                   'version should exist' % name)
 
         except ImportError:
             if modulepolicy == 'c':
                 raise
 
             # Could not load the C extension and pure Python is allowed. So
             # try to load them.
             from . import pure
             modinfo = imp.find_module(stem, pure.__path__)
             if not modinfo:
                 raise ImportError('could not find mercurial module %s' %
                                   name)
 
         mod = imp.load_module(name, *modinfo)
         sys.modules[name] = mod
         return mod
 
 # We automagically register our custom importer as a side-effect of loading.
 # This is necessary to ensure that any entry points are able to import
 # mercurial.* modules without having to perform this registration themselves.
 if not any(isinstance(x, hgimporter) for x in sys.meta_path):
     # meta_path is used before any implicit finders and before sys.path.
     sys.meta_path.insert(0, hgimporter())

setup.py

@@ -1,673 +1,668
 #
 # This is the mercurial setup script.
 #
 # 'python setup.py install', or
 # 'python setup.py --help' for more options
 
 import sys, platform
 if getattr(sys, 'version_info', (0, 0, 0)) < (2, 6, 0, 'final'):
     raise SystemExit("Mercurial requires Python 2.6 or later.")
 
 if sys.version_info[0] >= 3:
     printf = eval('print')
     libdir_escape = 'unicode_escape'
 else:
     libdir_escape = 'string_escape'
     def printf(*args, **kwargs):
         f = kwargs.get('file', sys.stdout)
         end = kwargs.get('end', '\n')
         f.write(b' '.join(args) + end)
 
 # Solaris Python packaging brain damage
 try:
     import hashlib
     sha = hashlib.sha1()
 except ImportError:
     try:
         import sha
         sha.sha # silence unused import warning
     except ImportError:
         raise SystemExit(
             "Couldn't import standard hashlib (incomplete Python install).")
 
 try:
     import zlib
     zlib.compressobj # silence unused import warning
 except ImportError:
     raise SystemExit(
         "Couldn't import standard zlib (incomplete Python install).")
 
 # The base IronPython distribution (as of 2.7.1) doesn't support bz2
 isironpython = False
 try:
     isironpython = (platform.python_implementation()
                     .lower().find("ironpython") != -1)
 except AttributeError:
     pass
 
 if isironpython:
     sys.stderr.write("warning: IronPython detected (no bz2 support)\n")
 else:
     try:
         import bz2
         bz2.BZ2Compressor # silence unused import warning
     except ImportError:
         raise SystemExit(
             "Couldn't import standard bz2 (incomplete Python install).")
 
 ispypy = "PyPy" in sys.version
 
 import os, stat, subprocess, time
 import re
 import shutil
 import tempfile
 from distutils import log
 if 'FORCE_SETUPTOOLS' in os.environ:
     from setuptools import setup
 else:
     from distutils.core import setup
 from distutils.core import Command, Extension
 from distutils.dist import Distribution
 from distutils.command.build import build
 from distutils.command.build_ext import build_ext
 from distutils.command.build_py import build_py
 from distutils.command.build_scripts import build_scripts
 from distutils.command.install_lib import install_lib
 from distutils.command.install_scripts import install_scripts
 from distutils.spawn import spawn, find_executable
 from distutils import file_util
 from distutils.errors import (
     CCompilerError,
     DistutilsError,
     DistutilsExecError,
 )
 from distutils.sysconfig import get_python_inc, get_config_var
 from distutils.version import StrictVersion
 
 scripts = ['hg']
 if os.name == 'nt':
     # We remove hg.bat if we are able to build hg.exe.
     scripts.append('contrib/win32/hg.bat')
 
 # simplified version of distutils.ccompiler.CCompiler.has_function
 # that actually removes its temporary files.
 def hasfunction(cc, funcname):
     tmpdir = tempfile.mkdtemp(prefix='hg-install-')
     devnull = oldstderr = None
     try:
         fname = os.path.join(tmpdir, 'funcname.c')
         f = open(fname, 'w')
         f.write('int main(void) {\n')
         f.write('    %s();\n' % funcname)
         f.write('}\n')
         f.close()
         # Redirect stderr to /dev/null to hide any error messages
         # from the compiler.
         # This will have to be changed if we ever have to check
         # for a function on Windows.
         devnull = open('/dev/null', 'w')
         oldstderr = os.dup(sys.stderr.fileno())
         os.dup2(devnull.fileno(), sys.stderr.fileno())
         objects = cc.compile([fname], output_dir=tmpdir)
         cc.link_executable(objects, os.path.join(tmpdir, "a.out"))
         return True
     except Exception:
         return False
     finally:
         if oldstderr is not None:
             os.dup2(oldstderr, sys.stderr.fileno())
         if devnull is not None:
             devnull.close()
         shutil.rmtree(tmpdir)
 
 # py2exe needs to be installed to work
 try:
     import py2exe
     py2exe.Distribution # silence unused import warning
     py2exeloaded = True
     # import py2exe's patched Distribution class
     from distutils.core import Distribution
 except ImportError:
     py2exeloaded = False
 
 def runcmd(cmd, env):
     if (sys.platform == 'plan9'
        and (sys.version_info[0] == 2 and sys.version_info[1] < 7)):
         # subprocess kludge to work around issues in half-baked Python
         # ports, notably bichued/python:
         _, out, err = os.popen3(cmd)
         return str(out), str(err)
     else:
         p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE, env=env)
         out, err = p.communicate()
         return out, err
 
 def runhg(cmd, env):
     out, err = runcmd(cmd, env)
     # If root is executing setup.py, but the repository is owned by
     # another user (as in "sudo python setup.py install") we will get
     # trust warnings since the .hg/hgrc file is untrusted. That is
     # fine, we don't want to load it anyway.  Python may warn about
     # a missing __init__.py in mercurial/locale, we also ignore that.
     err = [e for e in err.splitlines()
            if not e.startswith(b'not trusting file') \
               and not e.startswith(b'warning: Not importing') \
               and not e.startswith(b'obsolete feature not enabled')]
     if err:
         printf("stderr from '%s':" % (' '.join(cmd)), file=sys.stderr)
         printf(b'\n'.join([b'  ' + e for e in err]), file=sys.stderr)
         return ''
     return out
 
 version = ''
 
 # Execute hg out of this directory with a custom environment which takes care
 # to not use any hgrc files and do no localization.
 env = {'HGMODULEPOLICY': 'py',
        'HGRCPATH': '',
        'LANGUAGE': 'C'}
 if 'LD_LIBRARY_PATH' in os.environ:
     env['LD_LIBRARY_PATH'] = os.environ['LD_LIBRARY_PATH']
 if 'SystemRoot' in os.environ:
     # Copy SystemRoot into the custom environment for Python 2.6
     # under Windows. Otherwise, the subprocess will fail with
     # error 0xc0150004. See: http://bugs.python.org/issue3440
     env['SystemRoot'] = os.environ['SystemRoot']
 
 if os.path.isdir('.hg'):
     cmd = [sys.executable, 'hg', 'log', '-r', '.', '--template', '{tags}\n']
     numerictags = [t for t in runhg(cmd, env).split() if t[0].isdigit()]
     hgid = runhg([sys.executable, 'hg', 'id', '-i'], env).strip()
     if numerictags: # tag(s) found
         version = numerictags[-1]
         if hgid.endswith('+'): # propagate the dirty status to the tag
             version += '+'
     else: # no tag found
         ltagcmd = [sys.executable, 'hg', 'parents', '--template',
                    '{latesttag}']
         ltag = runhg(ltagcmd, env)
         changessincecmd = [sys.executable, 'hg', 'log', '-T', 'x\n', '-r',
                            "only(.,'%s')" % ltag]
         changessince = len(runhg(changessincecmd, env).splitlines())
         version = '%s+%s-%s' % (ltag, changessince, hgid)
     if version.endswith('+'):
         version += time.strftime('%Y%m%d')
 elif os.path.exists('.hg_archival.txt'):
     kw = dict([[t.strip() for t in l.split(':', 1)]
                for l in open('.hg_archival.txt')])
     if 'tag' in kw:
         version = kw['tag']
     elif 'latesttag' in kw:
         if 'changessincelatesttag' in kw:
             version = '%(latesttag)s+%(changessincelatesttag)s-%(node).12s' % kw
         else:
             version = '%(latesttag)s+%(latesttagdistance)s-%(node).12s' % kw
     else:
         version = kw.get('node', '')[:12]
 
 if version:
     with open("mercurial/__version__.py", "w") as f:
         f.write('# this file is autogenerated by setup.py\n')
         f.write('version = "%s"\n' % version)
 
 try:
     from mercurial import __version__
     version = __version__.version
 except ImportError:
     version = 'unknown'
 
 class hgbuild(build):
     # Insert hgbuildmo first so that files in mercurial/locale/ are found
     # when build_py is run next.
     sub_commands = [('build_mo', None)] + build.sub_commands
 
 class hgbuildmo(build):
 
     description = "build translations (.mo files)"
 
     def run(self):
         if not find_executable('msgfmt'):
             self.warn("could not find msgfmt executable, no translations "
                      "will be built")
             return
 
         podir = 'i18n'
         if not os.path.isdir(podir):
             self.warn("could not find %s/ directory" % podir)
             return
 
         join = os.path.join
         for po in os.listdir(podir):
             if not po.endswith('.po'):
                 continue
             pofile = join(podir, po)
             modir = join('locale', po[:-3], 'LC_MESSAGES')
             mofile = join(modir, 'hg.mo')
             mobuildfile = join('mercurial', mofile)
             cmd = ['msgfmt', '-v', '-o', mobuildfile, pofile]
             if sys.platform != 'sunos5':
                 # msgfmt on Solaris does not know about -c
                 cmd.append('-c')
             self.mkpath(join('mercurial', modir))
             self.make_file([pofile], mobuildfile, spawn, (cmd,))
 
 
 class hgdist(Distribution):
     pure = ispypy
 
     global_options = Distribution.global_options + \
                      [('pure', None, "use pure (slow) Python "
                         "code instead of C extensions"),
                      ]
 
     def has_ext_modules(self):
         # self.ext_modules is emptied in hgbuildpy.finalize_options which is
         # too late for some cases
         return not self.pure and Distribution.has_ext_modules(self)
 
 class hgbuildext(build_ext):
 
     def build_extension(self, ext):
         try:
             build_ext.build_extension(self, ext)
         except CCompilerError:
             if not getattr(ext, 'optional', False):
                 raise
             log.warn("Failed to build optional extension '%s' (skipping)",
                      ext.name)
 
 class hgbuildscripts(build_scripts):
     def run(self):
         if os.name != 'nt' or self.distribution.pure:
             return build_scripts.run(self)
 
         exebuilt = False
         try:
             self.run_command('build_hgexe')
             exebuilt = True
         except (DistutilsError, CCompilerError):
             log.warn('failed to build optional hg.exe')
 
         if exebuilt:
             # Copying hg.exe to the scripts build directory ensures it is
             # installed by the install_scripts command.
             hgexecommand = self.get_finalized_command('build_hgexe')
             dest = os.path.join(self.build_dir, 'hg.exe')
             self.mkpath(self.build_dir)
             self.copy_file(hgexecommand.hgexepath, dest)
 
             # Remove hg.bat because it is redundant with hg.exe.
             self.scripts.remove('contrib/win32/hg.bat')
 
         return build_scripts.run(self)
 
 class hgbuildpy(build_py):
     def finalize_options(self):
         build_py.finalize_options(self)
 
         if self.distribution.pure:
             self.distribution.ext_modules = []
         else:
             h = os.path.join(get_python_inc(), 'Python.h')
             if not os.path.exists(h):
                 raise SystemExit('Python headers are required to build '
                                  'Mercurial but weren\'t found in %s' % h)
 
-    def copy_file(self, *args, **kwargs):
-        dst, copied = build_py.copy_file(self, *args, **kwargs)
-
-        if copied and dst.endswith('__init__.py'):
+    def run(self):
             if self.distribution.pure:
                 modulepolicy = 'py'
             else:
                 modulepolicy = 'c'
-            content = open(dst, 'rb').read()
-            content = content.replace(b'@MODULELOADPOLICY@',
-                                      modulepolicy.encode(libdir_escape))
-            with open(dst, 'wb') as fh:
-                fh.write(content)
+        with open("mercurial/__modulepolicy__.py", "w") as f:
+            f.write('# this file is autogenerated by setup.py\n')
+            f.write('modulepolicy = "%s"\n' % modulepolicy)
 
-        return dst, copied
+        build_py.run(self)
 
 class buildhgextindex(Command):
     description = 'generate prebuilt index of hgext (for frozen package)'
     user_options = []
     _indexfilename = 'hgext/__index__.py'
 
     def initialize_options(self):
         pass
 
     def finalize_options(self):
         pass
 
     def run(self):
         if os.path.exists(self._indexfilename):
             with open(self._indexfilename, 'w') as f:
                 f.write('# empty\n')
 
         # here no extension enabled, disabled() lists up everything
         code = ('import pprint; from mercurial import extensions; '
                 'pprint.pprint(extensions.disabled())')
         out, err = runcmd([sys.executable, '-c', code], env)
         if err:
             raise DistutilsExecError(err)
 
         with open(self._indexfilename, 'w') as f:
             f.write('# this file is autogenerated by setup.py\n')
             f.write('docs = ')
             f.write(out)
 
 class buildhgexe(build_ext):
     description = 'compile hg.exe from mercurial/exewrapper.c'
 
     def build_extensions(self):
         if os.name != 'nt':
             return
         if isinstance(self.compiler, HackedMingw32CCompiler):
             self.compiler.compiler_so = self.compiler.compiler # no -mdll
             self.compiler.dll_libraries = [] # no -lmsrvc90
         hv = sys.hexversion
         pythonlib = 'python%d%d' % (hv >> 24, (hv >> 16) & 0xff)
         with open('mercurial/hgpythonlib.h', 'wb') as f:
             f.write('/* this file is autogenerated by setup.py */\n')
             f.write('#define HGPYTHONLIB "%s"\n' % pythonlib)
         objects = self.compiler.compile(['mercurial/exewrapper.c'],
                                          output_dir=self.build_temp)
         dir = os.path.dirname(self.get_ext_fullpath('dummy'))
         target = os.path.join(dir, 'hg')
         self.compiler.link_executable(objects, target,
                                       libraries=[],
                                       output_dir=self.build_temp)
 
     @property
     def hgexepath(self):
         dir = os.path.dirname(self.get_ext_fullpath('dummy'))
         return os.path.join(self.build_temp, dir, 'hg.exe')
 
 class hginstalllib(install_lib):
     '''
     This is a specialization of install_lib that replaces the copy_file used
     there so that it supports setting the mode of files after copying them,
     instead of just preserving the mode that the files originally had.  If your
     system has a umask of something like 027, preserving the permissions when
     copying will lead to a broken install.
 
     Note that just passing keep_permissions=False to copy_file would be
     insufficient, as it might still be applying a umask.
     '''
 
     def run(self):
         realcopyfile = file_util.copy_file
         def copyfileandsetmode(*args, **kwargs):
             src, dst = args[0], args[1]
             dst, copied = realcopyfile(*args, **kwargs)
             if copied:
                 st = os.stat(src)
                 # Persist executable bit (apply it to group and other if user
                 # has it)
                 if st[stat.ST_MODE] & stat.S_IXUSR:
                     setmode = int('0755', 8)
                 else:
                     setmode = int('0644', 8)
                 m = stat.S_IMODE(st[stat.ST_MODE])
                 m = (m & ~int('0777', 8)) | setmode
                 os.chmod(dst, m)
         file_util.copy_file = copyfileandsetmode
         try:
             install_lib.run(self)
         finally:
             file_util.copy_file = realcopyfile
 
 class hginstallscripts(install_scripts):
     '''
     This is a specialization of install_scripts that replaces the @LIBDIR@ with
     the configured directory for modules. If possible, the path is made relative
     to the directory for scripts.
     '''
 
     def initialize_options(self):
         install_scripts.initialize_options(self)
 
         self.install_lib = None
 
     def finalize_options(self):
         install_scripts.finalize_options(self)
         self.set_undefined_options('install',
                                    ('install_lib', 'install_lib'))
 
     def run(self):
         install_scripts.run(self)
 
         # It only makes sense to replace @LIBDIR@ with the install path if
         # the install path is known. For wheels, the logic below calculates
         # the libdir to be "../..". This is because the internal layout of a
         # wheel archive looks like:
         #
         #   mercurial-3.6.1.data/scripts/hg
         #   mercurial/__init__.py
         #
         # When installing wheels, the subdirectories of the "<pkg>.data"
         # directory are translated to system local paths and files therein
         # are copied in place. The mercurial/* files are installed into the
         # site-packages directory. However, the site-packages directory
         # isn't known until wheel install time. This means we have no clue
         # at wheel generation time what the installed site-packages directory
         # will be. And, wheels don't appear to provide the ability to register
         # custom code to run during wheel installation. This all means that
         # we can't reliably set the libdir in wheels: the default behavior
         # of looking in sys.path must do.
 
         if (os.path.splitdrive(self.install_dir)[0] !=
             os.path.splitdrive(self.install_lib)[0]):
             # can't make relative paths from one drive to another, so use an
             # absolute path instead
             libdir = self.install_lib
         else:
             common = os.path.commonprefix((self.install_dir, self.install_lib))
             rest = self.install_dir[len(common):]
             uplevel = len([n for n in os.path.split(rest) if n])
 
             libdir = uplevel * ('..' + os.sep) + self.install_lib[len(common):]
 
         for outfile in self.outfiles:
             with open(outfile, 'rb') as fp:
                 data = fp.read()
 
             # skip binary files
             if b'\0' in data:
                 continue
 
             # During local installs, the shebang will be rewritten to the final
             # install path. During wheel packaging, the shebang has a special
             # value.
             if data.startswith(b'#!python'):
                 log.info('not rewriting @LIBDIR@ in %s because install path '
                          'not known' % outfile)
                 continue
 
             data = data.replace(b'@LIBDIR@', libdir.encode(libdir_escape))
             with open(outfile, 'wb') as fp:
                 fp.write(data)
 
 cmdclass = {'build': hgbuild,
             'build_mo': hgbuildmo,
             'build_ext': hgbuildext,
             'build_py': hgbuildpy,
             'build_scripts': hgbuildscripts,
             'build_hgextindex': buildhgextindex,
             'install_lib': hginstalllib,
             'install_scripts': hginstallscripts,
             'build_hgexe': buildhgexe,
             }
 
 packages = ['mercurial', 'mercurial.hgweb', 'mercurial.httpclient',
             'mercurial.pure',
             'hgext', 'hgext.convert', 'hgext.highlight', 'hgext.zeroconf',
             'hgext.largefiles']
 
 common_depends = ['mercurial/util.h']
 
 osutil_ldflags = []
 
 if sys.platform == 'darwin':
     osutil_ldflags += ['-framework', 'ApplicationServices']
 
 extmodules = [
     Extension('mercurial.base85', ['mercurial/base85.c'],
               depends=common_depends),
     Extension('mercurial.bdiff', ['mercurial/bdiff.c'],
               depends=common_depends),
     Extension('mercurial.diffhelpers', ['mercurial/diffhelpers.c'],
               depends=common_depends),
     Extension('mercurial.mpatch', ['mercurial/mpatch.c'],
               depends=common_depends),
     Extension('mercurial.parsers', ['mercurial/dirs.c',
                                     'mercurial/manifest.c',
                                     'mercurial/parsers.c',
                                     'mercurial/pathencode.c'],
               depends=common_depends),
     Extension('mercurial.osutil', ['mercurial/osutil.c'],
               extra_link_args=osutil_ldflags,
               depends=common_depends),
     ]
 
 try:
     from distutils import cygwinccompiler
 
     # the -mno-cygwin option has been deprecated for years
     compiler = cygwinccompiler.Mingw32CCompiler
 
     class HackedMingw32CCompiler(cygwinccompiler.Mingw32CCompiler):
         def __init__(self, *args, **kwargs):
             compiler.__init__(self, *args, **kwargs)
             for i in 'compiler compiler_so linker_exe linker_so'.split():
                 try:
                     getattr(self, i).remove('-mno-cygwin')
                 except ValueError:
                     pass
 
     cygwinccompiler.Mingw32CCompiler = HackedMingw32CCompiler
 except ImportError:
     # the cygwinccompiler package is not available on some Python
     # distributions like the ones from the optware project for Synology
     # DiskStation boxes
     class HackedMingw32CCompiler(object):
         pass
 
 packagedata = {'mercurial': ['locale/*/LC_MESSAGES/hg.mo',
                              'help/*.txt',
                              'help/internals/*.txt',
                              'default.d/*.rc',
                              'dummycert.pem']}
 
 def ordinarypath(p):
     return p and p[0] != '.' and p[-1] != '~'
 
 for root in ('templates',):
     for curdir, dirs, files in os.walk(os.path.join('mercurial', root)):
         curdir = curdir.split(os.sep, 1)[1]
         dirs[:] = filter(ordinarypath, dirs)
         for f in filter(ordinarypath, files):
             f = os.path.join(curdir, f)
             packagedata['mercurial'].append(f)
 
 datafiles = []
 setupversion = version
 extra = {}
 
 if py2exeloaded:
     extra['console'] = [
         {'script':'hg',
          'copyright':'Copyright (C) 2005-2016 Matt Mackall and others',
          'product_version':version}]
     # sub command of 'build' because 'py2exe' does not handle sub_commands
     build.sub_commands.insert(0, ('build_hgextindex', None))
     # put dlls in sub directory so that they won't pollute PATH
     extra['zipfile'] = 'lib/library.zip'
 
 if os.name == 'nt':
     # Windows binary file versions for exe/dll files must have the
     # form W.X.Y.Z, where W,X,Y,Z are numbers in the range 0..65535
     setupversion = version.split('+', 1)[0]
 
 if sys.platform == 'darwin' and os.path.exists('/usr/bin/xcodebuild'):
     version = runcmd(['/usr/bin/xcodebuild', '-version'], {})[0].splitlines()
     if version:
         version = version[0]
         if sys.version_info[0] == 3:
             version = version.decode('utf-8')
         xcode4 = (version.startswith('Xcode') and
                   StrictVersion(version.split()[1]) >= StrictVersion('4.0'))
         xcode51 = re.match(r'^Xcode\s+5\.1', version) is not None
     else:
         # xcodebuild returns empty on OS X Lion with XCode 4.3 not
         # installed, but instead with only command-line tools. Assume
         # that only happens on >= Lion, thus no PPC support.
         xcode4 = True
         xcode51 = False
 
     # XCode 4.0 dropped support for ppc architecture, which is hardcoded in
     # distutils.sysconfig
     if xcode4:
         os.environ['ARCHFLAGS'] = ''
 
     # XCode 5.1 changes clang such that it now fails to compile if the
     # -mno-fused-madd flag is passed, but the version of Python shipped with
     # OS X 10.9 Mavericks includes this flag. This causes problems in all
     # C extension modules, and a bug has been filed upstream at
     # http://bugs.python.org/issue21244. We also need to patch this here
     # so Mercurial can continue to compile in the meantime.
     if xcode51:
         cflags = get_config_var('CFLAGS')
         if cflags and re.search(r'-mno-fused-madd\b', cflags) is not None:
             os.environ['CFLAGS'] = (
                 os.environ.get('CFLAGS', '') + ' -Qunused-arguments')
 
 setup(name='mercurial',
       version=setupversion,
       author='Matt Mackall and many others',
       author_email='[e-mail]',
       url='https://mercurial-scm.org/',
       download_url='https://mercurial-scm.org/release/',
       description=('Fast scalable distributed SCM (revision control, version '
                    'control) system'),
       long_description=('Mercurial is a distributed SCM tool written in Python.'
                         ' It is used by a number of large projects that require'
                         ' fast, reliable distributed revision control, such as '
                         'Mozilla.'),
       license='GNU GPLv2 or any later version',
       classifiers=[
           'Development Status :: 6 - Mature',
           'Environment :: Console',
           'Intended Audience :: Developers',
           'Intended Audience :: System Administrators',
           'License :: OSI Approved :: GNU General Public License (GPL)',
           'Natural Language :: Danish',
           'Natural Language :: English',
           'Natural Language :: German',
           'Natural Language :: Italian',
           'Natural Language :: Japanese',
           'Natural Language :: Portuguese (Brazilian)',
           'Operating System :: Microsoft :: Windows',
           'Operating System :: OS Independent',
           'Operating System :: POSIX',
           'Programming Language :: C',
           'Programming Language :: Python',
           'Topic :: Software Development :: Version Control',
       ],
       scripts=scripts,
       packages=packages,
       ext_modules=extmodules,
       data_files=datafiles,
       package_data=packagedata,
       cmdclass=cmdclass,
       distclass=hgdist,
       options={'py2exe': {'packages': ['hgext', 'email']},
                'bdist_mpkg': {'zipdist': False,
                               'license': 'COPYING',
                               'readme': 'contrib/macosx/Readme.html',
                               'welcome': 'contrib/macosx/Welcome.html',
                               },
                },
       **extra)