bt2: honor build system compiler/linker preferences

[babeltrace.git] / src / bindings / python / bt2 / setup.py.in

# The MIT License (MIT)
#
# Copyright (C) 2017 - Francis Deslauriers <francis.deslauriers@efficios.com>
# Copyright (C) 2020 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

import sys
import os
import distutils.sysconfig

from distutils.core import setup, Extension

PY_PATH_WARN_MSG = """
-------------------------------------WARNING------------------------------------
The install directory used:\n ({})\nis not included in your PYTHONPATH.

To add this directory to your Python search path permanently you can add the
following command to your .bashrc/.zshrc:
    export PYTHONPATH="${{PYTHONPATH}}:{}"
--------------------------------------------------------------------------------
"""

original_get_config_vars = distutils.sysconfig.get_config_vars


def get_cflags():
    cflags = os.environ.get('CFLAGS')

    if cflags is None:
        [cflags] = original_get_config_vars('CFLAGS')

    return cflags


# distutils performs a similar transformation step on LDSHARED on
# darwin to use the overriden CC as the default command for LDSHARED
# (see distutils' customize_compiler() step in the sysconfig module).
#
# This takes it a step further by using our own LDFLAGS (when available)
# along with the overriden compiler and ensure that flags that are unsupported
# by either the Python interprter's CC or the overriden CC don't cause a
# build failure.
def get_ldshared():
    cc = os.environ.get('CC')
    ldflags = os.environ.get('LDFLAGS')
    [py_cc] = original_get_config_vars('CC')
    [py_ldshared] = original_get_config_vars('LDSHARED')

    if not py_ldshared.startswith(py_cc):
        return py_ldshared

    if cc and ldflags:
        return '{} -shared {}'.format(cc, ldflags)
    elif cc:
        return cc + py_ldshared[len(py_cc) :]
    elif ldflags:
        return py_cc + py_ldshared[len(py_cc) :]
    else:
        return py_ldshared


def our_get_config_vars(*args):
    overridden_config_vars = {
        'CFLAGS': get_cflags(),
        'LDSHARED': get_ldshared(),
    }

    if len(args) == 0:
        all_config_vars = original_get_config_vars()
        for name in overridden_config_vars:
            all_config_vars[name] = overridden_config_vars[name]
        return all_config_vars

    subset_config_vars = []
    for name in args:
        if name not in overridden_config_vars:
            [var] = original_get_config_vars(name)
            subset_config_vars.append(var)
            continue

        subset_config_vars.append(overridden_config_vars[name])

    return subset_config_vars


distutils.sysconfig.get_config_vars = our_get_config_vars


def main():
    babeltrace_ext = Extension(
        'bt2._native_bt',
        sources=['bt2/native_bt.c', '@srcdir@/bt2/logging.c'],
        libraries=['babeltrace2', 'glib-2.0'],
        extra_objects=[
            '@top_builddir@/src/autodisc/.libs/libbabeltrace2-autodisc.a',
            '@top_builddir@/src/logging/.libs/libbabeltrace2-logging.a',
            '@top_builddir@/src/common/.libs/libbabeltrace2-common.a',
            '@top_builddir@/src/py-common/.libs/libbabeltrace2-py-common.a',
            '@top_builddir@/src/string-format/.libs/libbabeltrace2-string-format.a',
        ],
    )

    dist = setup(
        name='bt2',
        version='@PACKAGE_VERSION@',
        description='Babeltrace 2 Python Bindings',
        packages=['bt2'],
        package_dir={'bt2': 'bt2'},
        options={
            'build': {'build_base': 'build', 'build_lib': 'build/build_lib'},
            'build_ext': {'build_lib': 'build/build_lib'},
        },
        url='https://babeltrace.org/',
        ext_modules=[babeltrace_ext],
        license='MIT',
        classifiers=[
            'Development Status :: 5 - Production/Stable',
            'Intended Audience :: Developers',
            'License :: OSI Approved :: The MIT License',
            'Programming Language :: Python :: 3' 'Topic :: System :: Logging',
        ],
    )

    # After the installation, we check that the install directory is included in
    # the Python search path and we print a warning message when it's not.
    # We need to do this because Python search path differs depending on the distro
    # and some distros don't include any /usr/local/ in the search path. This is
    # also useful for out-of-tree installs and tests.
    # It's only relevant to make this check on the `install` command.

    if 'install' in dist.command_obj:
        install_dir = dist.command_obj['install'].install_libbase
        if install_dir not in sys.path:
            # We can't consider this an error because if affects every
            # distro differently. We only warn the user that some
            # extra configuration is needed to use the bindings
            print(PY_PATH_WARN_MSG.format(install_dir, install_dir))


if __name__ == "__main__":
    main()