rust_ext.py

# From https://github.com/novocaine/rust-python-ext
# The MIT License (MIT)
#
# Copyright (c) 2015 James Salter
#
# 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.
from __future__ import print_function
import platform
import sys
import subprocess
import os.path
import glob
from distutils.cmd import Command
from distutils.command.install_lib import install_lib
import shutil


class RustBuildCommand(Command):
    """
    Command for building rust crates via cargo.
    Don't use this directly; use the build_rust_cmdclass
    factory method.
    """

    description = "build rust crates into Python extensions"

    user_options = []

    def _unpack_classargs(self):
        for k, v in self.__class__.args.items():
            setattr(self, k, v)

    def initialize_options(self):
        self._unpack_classargs()

    def finalize_options(self):
        pass

    def run(self):
        if self.debug:
            self.debug_or_release = "--debug"
        else:
            self.debug_or_release = "--release"

        # Make sure that if pythonXX-sys is used, it builds against the current
        # executing python interpreter.
        bindir = os.path.dirname(sys.executable)

        env = os.environ
        # disables rust's pkg-config seeking for specified packages,
        # which causes pythonXX-sys to fall back to detecting the
        # interpreter from the path.
        env["PYTHON_2.7_NO_PKG_CONFIG"] = "1"
        env["PATH"] = bindir + os.pathsep + os.environ.get("PATH", "")

        # Execute cargo.
        try:
            args = (["cargo", "build", "--manifest-path", self.cargo_toml_path,
                self.debug_or_release, "--verbose"] + list(self.extra_cargo_args or []))
            if not self.quiet:
                print(" ".join(args), file=sys.stderr)
            output = subprocess.check_output(
                ' '.join(args),
                env=env,
                shell=True,
                stderr=subprocess.STDOUT
            )
        except subprocess.CalledProcessError as e:
            msg = "cargo failed with code: %d\n%s" % (e.returncode, e.output)
            raise Exception(msg)
        except OSError:
            raise Exception("Unable to execute 'cargo' - this package "
                "requires rust to be installed and cargo to be on the PATH")

        if not self.quiet:
            print(output, file=sys.stderr)

        # Find the shared library that cargo hopefully produced and copy
        # it into the build directory as if it were produced by build_cext.
        if self.debug:
            suffix = "debug"
        else:
            suffix = "release"

        target_dir = os.path.join(os.path.dirname(self.cargo_toml_path),
            "target/", suffix)

        if sys.platform == "win32":
            wildcard_so = "*.dll"
        elif sys.platform == "darwin":
            wildcard_so = "*.dylib"
        else:
            wildcard_so = "*.so"

        try:
            dylib_path = glob.glob(os.path.join(target_dir, wildcard_so))[0]
        except IndexError:
            raise Exception("rust build failed; unable to find any .dylib in %s" %
                target_dir)

        # Ask build_ext where the shared library would go if it had built it,
        # then copy it there.
        build_ext = self.get_finalized_command('build_ext')
        target_fname = os.path.splitext(os.path.basename(dylib_path)[3:])[0]
        ext_path = build_ext.get_ext_fullpath(os.path.basename(target_fname))
        try:
            os.makedirs(os.path.dirname(ext_path))
        except OSError:
            pass
        shutil.copyfile(dylib_path, ext_path)


def build_rust_cmdclass(cargo_toml_path, debug=False,
                        extra_cargo_args=None, quiet=False):
    """
    Args:
        cargo_toml_path (str)   The path to the cargo.toml manifest
                                (--manifest)
        debug (boolean)         Controls whether --debug or --release is
                                passed to cargo.
        extra_carg_args (list)  A list of extra argumenents to be passed to
                                cargo.
        quiet (boolean)         If True, doesn't echo cargo's output.
    Returns:
        A Command subclass suitable for passing to the cmdclass argument
        of distutils.
    """

    # Manufacture a once-off command class here and set the params on it as
    # class members, which it can retrieve later in initialize_options.
    # This is clumsy, but distutils doesn't give you an appropriate
    # hook for passing params to custom command classes (and it does the
    # instantiation).

    _args = locals()

    class RustBuildCommand_Impl(RustBuildCommand):
        args = _args

    return RustBuildCommand_Impl


class install_lib_including_rust(install_lib):
    """
    A replacement install_lib cmdclass that remembers to build_rust
    during install_lib.
    Typically you want to use this so that the usual 'setup.py install'
    just works.
    """

    def build(self):
        install_lib.build(self)
        if not self.skip_build:
            self.run_command('build_rust')