_setupares.py

# -*- coding: utf-8 -*-
"""
setup helpers for c-ares.
"""

from __future__ import print_function, absolute_import, division

import os
import os.path
import shutil
import sys

from _setuputils import Extension

import distutils.sysconfig  # to get CFLAGS to pass into c-ares configure script pylint:disable=import-error

from _setuputils import WIN
from _setuputils import quoted_dep_abspath
from _setuputils import system
from _setuputils import should_embed
from _setuputils import LIBRARIES
from _setuputils import DEFINE_MACROS
from _setuputils import glob_many
from _setuputils import dep_abspath
from _setuputils import RUNNING_ON_CI
from _setuputils import RUNNING_FROM_CHECKOUT
from _setuputils import cythonize1
from _setuputils import get_include_dirs


CARES_EMBED = should_embed('c-ares')

# See #616, trouble building for a 32-bit python on a 64-bit platform
# (Linux).
_distutils_cflags = distutils.sysconfig.get_config_var("CFLAGS") or ''
cflags = _distutils_cflags + ((' ' + os.environ['CFLAGS']) if os.environ.get("CFLAGS") else '')
cflags = ('CFLAGS="%s"' % (cflags,)) if cflags else ''


# Use -r, not -e, for support of old solaris. See
# https://github.com/gevent/gevent/issues/777
ares_configure_command = ' '.join([
    "(cd ", quoted_dep_abspath('c-ares'),
    " && if [ -r ares_build.h ]; then cp ares_build.h ares_build.h.orig; fi ",
    " && sh ./configure --disable-dependency-tracking -C " + cflags,
    " && cp ares_config.h ares_build.h \"$OLDPWD\" ",
    " && cat ares_build.h ",
    " && if [ -r ares_build.h.orig ]; then mv ares_build.h.orig ares_build.h; fi)",
    "> configure-output.txt"
])

if 'GEVENT_MANYLINUX' in os.environ:
    # Assumes that c-ares is pre-configured.
    ares_configure_command = '(echo preconfigured) > configure-output.txt'



def configure_ares(bext, ext):
    print("Embedding c-ares", bext, ext)
    bdir = os.path.join(bext.build_temp, 'c-ares')
    ext.include_dirs.insert(0, bdir)
    print("Inserted ", bdir, "in include dirs", ext.include_dirs)

    if not os.path.isdir(bdir):
        os.makedirs(bdir)

    if WIN:
        src = "deps\\c-ares\\ares_build.h.dist"
        dest = os.path.join(bdir, "ares_build.h")
        print("Copying %r to %r" % (src, dest))
        shutil.copy(src, dest)
        return

    cwd = os.getcwd()
    os.chdir(bdir)
    try:
        if os.path.exists('ares_config.h') and os.path.exists('ares_build.h'):
            return
        try:
            system(ares_configure_command)
        except:
            with open('configure-output.txt', 'r') as t:
                print(t.read(), file=sys.stderr)
            raise
    finally:
        os.chdir(cwd)


ARES = Extension(
    name='gevent.resolver.cares',
    sources=[
        'src/gevent/resolver/cares.pyx'
    ],
    include_dirs=get_include_dirs(*([dep_abspath('c-ares')] if CARES_EMBED else [])),
    libraries=list(LIBRARIES),
    define_macros=list(DEFINE_MACROS),
    depends=glob_many(
        'src/gevent/resolver/cares_*.[ch]')
)

ares_required = RUNNING_ON_CI and RUNNING_FROM_CHECKOUT
ARES.optional = not ares_required


if CARES_EMBED:
    ARES.sources += glob_many('deps/c-ares/*.c')
    # Strip the standalone binaries that would otherwise
    # cause linking issues
    for bin_c in ('acountry', 'adig', 'ahost'):
        ARES.sources.remove('deps/c-ares' + os.sep + bin_c + '.c')
    ARES.configure = configure_ares
    if WIN:
        ARES.libraries += ['advapi32']
        ARES.define_macros += [('CARES_STATICLIB', '')]
    else:
        ARES.define_macros += [('HAVE_CONFIG_H', '')]
        if sys.platform != 'darwin':
            ARES.libraries += ['rt']
        else:
            # libresolv dependency introduced in
            # c-ares 1.16.1.
            ARES.libraries += ['resolv']
    ARES.define_macros += [('CARES_EMBED', '1')]
else:
    ARES.libraries.append('cares')
    ARES.define_macros += [('HAVE_NETDB_H', '')]
    ARES.configure = lambda bext, ext: print("c-ares not embedded, not configuring", bext, ext)

ARES = cythonize1(ARES)