view contrib/python-zstandard/setup_zstd.py @ 42172:71d8b4d91616 stable

setup: properly package distutils in py2exe virtualenv builds

Our in-repo py2exe packaging code uses virtualenvs for managing
dependencies. An advantage of this is that packaging is more
deterministic and reproducible. Without virtualenvs, we need to
install packages in the system Python install. Packages installed
by other consumers of the system Python could leak into the Mercurial
package.

A regression from this change was that py2exe packages contained
the virtualenv's hacked distutils modules instead of the original
distutils modules. (virtualenv installs a hacked distutils module
because distutils uses relative path lookups that fail when running
from a virtualenv.)

This commit introduces a workaround so py2exe packaging uses the
original distutils modules when running from a virtualenv.

With this change, `import distutils` no longer fails from py2exe
builds produced from a virtualenv. This fixes the regression.
Furthermore, we now include all distutils modules. Before, py2exe's
module finding would only find modules there were explicitly
referenced in code. So, we now package a complete copy of distutils
instead of a partial one. This is even better than before.

# no-check-commit foo_bar function name

# Copyright (c) 2016-present, Gregory Szorc
# All rights reserved.
#
# This software may be modified and distributed under the terms
# of the BSD license. See the LICENSE file for details.

import distutils.ccompiler
import os

from distutils.extension import Extension


zstd_sources = ['zstd/%s' % p for p in (
    'common/debug.c',
    'common/entropy_common.c',
    'common/error_private.c',
    'common/fse_decompress.c',
    'common/pool.c',
    'common/threading.c',
    'common/xxhash.c',
    'common/zstd_common.c',
    'compress/fse_compress.c',
    'compress/hist.c',
    'compress/huf_compress.c',
    'compress/zstd_compress.c',
    'compress/zstd_double_fast.c',
    'compress/zstd_fast.c',
    'compress/zstd_lazy.c',
    'compress/zstd_ldm.c',
    'compress/zstd_opt.c',
    'compress/zstdmt_compress.c',
    'decompress/huf_decompress.c',
    'decompress/zstd_ddict.c',
    'decompress/zstd_decompress.c',
    'decompress/zstd_decompress_block.c',
    'dictBuilder/cover.c',
    'dictBuilder/divsufsort.c',
    'dictBuilder/fastcover.c',
    'dictBuilder/zdict.c',
)]

zstd_sources_legacy = ['zstd/%s' % p for p in (
    'deprecated/zbuff_common.c',
    'deprecated/zbuff_compress.c',
    'deprecated/zbuff_decompress.c',
    'legacy/zstd_v01.c',
    'legacy/zstd_v02.c',
    'legacy/zstd_v03.c',
    'legacy/zstd_v04.c',
    'legacy/zstd_v05.c',
    'legacy/zstd_v06.c',
    'legacy/zstd_v07.c'
)]

zstd_includes = [
    'zstd',
    'zstd/common',
    'zstd/compress',
    'zstd/decompress',
    'zstd/dictBuilder',
]

zstd_includes_legacy = [
    'zstd/deprecated',
    'zstd/legacy',
]

ext_includes = [
    'c-ext',
    'zstd/common',
]

ext_sources = [
    'zstd/common/pool.c',
    'zstd/common/threading.c',
    'zstd.c',
    'c-ext/bufferutil.c',
    'c-ext/compressiondict.c',
    'c-ext/compressobj.c',
    'c-ext/compressor.c',
    'c-ext/compressoriterator.c',
    'c-ext/compressionchunker.c',
    'c-ext/compressionparams.c',
    'c-ext/compressionreader.c',
    'c-ext/compressionwriter.c',
    'c-ext/constants.c',
    'c-ext/decompressobj.c',
    'c-ext/decompressor.c',
    'c-ext/decompressoriterator.c',
    'c-ext/decompressionreader.c',
    'c-ext/decompressionwriter.c',
    'c-ext/frameparams.c',
]

zstd_depends = [
    'c-ext/python-zstandard.h',
]


def get_c_extension(support_legacy=False, system_zstd=False, name='zstd',
                    warnings_as_errors=False, root=None):
    """Obtain a distutils.extension.Extension for the C extension.

    ``support_legacy`` controls whether to compile in legacy zstd format support.

    ``system_zstd`` controls whether to compile against the system zstd library.
    For this to work, the system zstd library and headers must match what
    python-zstandard is coded against exactly.

    ``name`` is the module name of the C extension to produce.

    ``warnings_as_errors`` controls whether compiler warnings are turned into
    compiler errors.

    ``root`` defines a root path that source should be computed as relative
    to. This should be the directory with the main ``setup.py`` that is
    being invoked. If not defined, paths will be relative to this file.
    """
    actual_root = os.path.abspath(os.path.dirname(__file__))
    root = root or actual_root

    sources = set([os.path.join(actual_root, p) for p in ext_sources])
    if not system_zstd:
        sources.update([os.path.join(actual_root, p) for p in zstd_sources])
        if support_legacy:
            sources.update([os.path.join(actual_root, p)
                            for p in zstd_sources_legacy])
    sources = list(sources)

    include_dirs = set([os.path.join(actual_root, d) for d in ext_includes])
    if not system_zstd:
        include_dirs.update([os.path.join(actual_root, d)
                             for d in zstd_includes])
        if support_legacy:
            include_dirs.update([os.path.join(actual_root, d)
                                 for d in zstd_includes_legacy])
    include_dirs = list(include_dirs)

    depends = [os.path.join(actual_root, p) for p in zstd_depends]

    compiler = distutils.ccompiler.new_compiler()

    # Needed for MSVC.
    if hasattr(compiler, 'initialize'):
        compiler.initialize()

    if compiler.compiler_type == 'unix':
        compiler_type = 'unix'
    elif compiler.compiler_type == 'msvc':
        compiler_type = 'msvc'
    elif compiler.compiler_type == 'mingw32':
        compiler_type = 'mingw32'
    else:
        raise Exception('unhandled compiler type: %s' %
                        compiler.compiler_type)

    extra_args = ['-DZSTD_MULTITHREAD']

    if not system_zstd:
        extra_args.append('-DZSTDLIB_VISIBILITY=')
        extra_args.append('-DZDICTLIB_VISIBILITY=')
        extra_args.append('-DZSTDERRORLIB_VISIBILITY=')

        if compiler_type == 'unix':
            extra_args.append('-fvisibility=hidden')

    if not system_zstd and support_legacy:
        extra_args.append('-DZSTD_LEGACY_SUPPORT=1')

    if warnings_as_errors:
        if compiler_type in ('unix', 'mingw32'):
            extra_args.append('-Werror')
        elif compiler_type == 'msvc':
            extra_args.append('/WX')
        else:
            assert False

    libraries = ['zstd'] if system_zstd else []

    # Python 3.7 doesn't like absolute paths. So normalize to relative.
    sources = [os.path.relpath(p, root) for p in sources]
    include_dirs = [os.path.relpath(p, root) for p in include_dirs]
    depends = [os.path.relpath(p, root) for p in depends]

    # TODO compile with optimizations.
    return Extension(name, sources,
                     include_dirs=include_dirs,
                     depends=depends,
                     extra_compile_args=extra_args,
                     libraries=libraries)