contrib/python-zstandard/setup_zstd.py

dirstate: fix restoration of "merged" state after a remove

Before this change, "merged" file that get removed and re-added later were
recorded as "from_p2" instead.

This came from 8fe74328f700, a 2014 changeset that start explicitly doing so
for reason I have not been able to fully grasp.  The graft test mentioned in
the description are still happy after this changeset.

So this changeset restore what seems to be the intended behavior. Restoring
information as it was before the removal.

Differential Revision: https://phab.mercurial-scm.org/D11429

# 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_literals.c",
        "compress/zstd_compress_sequences.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/error_private.c",
    "zstd/common/pool.c",
    "zstd/common/threading.c",
    "zstd/common/zstd_common.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,
    )