contrib/python-zstandard/setup_zstd.py

filemerge: show warning about choice of :prompt only at an actual fallback

Before this patch, internal merge tool :prompt shows "no tool found to
merge FILE" line, even if :prompt is explicitly specified as a tool to
be used.

This patch shows warning message about choice of :prompt only at an
actual fallback, in which case any tool is rejected by capability for
binary or symlink.

It is for backward compatibility to omit warning message in
"changedelete" case.

# 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 os
from distutils.extension import Extension


zstd_sources = ['zstd/%s' % p for p in (
    '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/huf_compress.c',
    'compress/zstd_compress.c',
    'compress/zstdmt_compress.c',
    'decompress/huf_decompress.c',
    'decompress/zstd_decompress.c',
    'dictBuilder/cover.c',
    'dictBuilder/divsufsort.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 = [
    'c-ext',
    'zstd',
    'zstd/common',
    'zstd/compress',
    'zstd/decompress',
    'zstd/dictBuilder',
]

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

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

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


def get_c_extension(support_legacy=False, name='zstd'):
    """Obtain a distutils.extension.Extension for the C extension."""
    root = os.path.abspath(os.path.dirname(__file__))

    sources = [os.path.join(root, p) for p in zstd_sources + ext_sources]
    if support_legacy:
        sources.extend([os.path.join(root, p) for p in zstd_sources_legacy])

    include_dirs = [os.path.join(root, d) for d in zstd_includes]
    if support_legacy:
        include_dirs.extend([os.path.join(root, d) for d in zstd_includes_legacy])

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

    extra_args = ['-DZSTD_MULTITHREAD']

    if support_legacy:
        extra_args.append('-DZSTD_LEGACY_SUPPORT=1')

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