Platforms/WASI/_package.py

__lazy_modules__ = [
    "datetime",
    "os",
    "pathlib",
    "shutil",
    "subprocess",
    "sys",
    "_shared",
]

import datetime
import os
import pathlib
import shutil
import subprocess
import sys

import _shared


def wasmtime_script(context):
    return f"""\
#!/bin/sh

set -eu

script_dir=$(CDPATH= cd "$(dirname "$0")" && pwd -P)
root=$(CDPATH= cd "$script_dir/.." && pwd -P)
wasm_file="$root/lib/python{python_version(context)}/lib-wasm/python{python_version(context, debug_ok=True)}.wasm"

exec wasmtime run \\
    --argv0 "$wasm_file" \\
    --config "$root/etc/python{python_version(context)}/wasmtime.toml" \\
    --dir "/" \\
    "$wasm_file" "$@"
"""


def python_version(context, debug_ok=False):
    """Calculate the M.N part of Python's version.

    If *debug_ok* is True, then "d" is appended as appropriate.
    """
    details = context.wasi_build_details
    major = details["language"]["version_info"]["major"]
    minor = details["language"]["version_info"]["minor"]
    version = f"{major}.{minor}"
    if debug_ok and context.is_debug:
        version += "d"
    return version


def lib_python(context):
    return pathlib.PurePath("lib") / f"python{python_version(context)}"


def license_file(context):
    """Have <src>/LICENSE end up as lib/pythonXY/LICENSE.txt."""
    return (lib_python(context) / "LICENSE.txt", context.checkout / "LICENSE")


def build_dir_files(context):
    """Have build/lib.* files end up in lib/pythonXY.

    Symlinks are skipped as those files are covered by handling
    <build>/Modules.
    """
    return [
        (lib_python(context) / path.name, path)
        for path in context.wasi_pybuilddir.iterdir()
        if path.is_file(follow_symlinks=False)
    ]


def stdlib_files(context):
    """Have <src>/Lib files end up in lib/pythonXY."""
    lib_dir = context.checkout / "Lib"
    lib_files = []
    for root, dirs, files in lib_dir.walk():
        try:
            dirs.remove("__pycache__")
        except ValueError:
            pass

        for file in files:
            file_path = pathlib.Path(root) / file
            details = (
                lib_python(context) / file_path.relative_to(lib_dir),
                file_path,
            )
            lib_files.append(details)
    return lib_files


def pkgconfig_files(context):
    """Have <src>/Misc/python*.pc end up in lib/pkgconfig.

    Each file ends up being listed under `python3` and `python-3.N`.
    """
    misc_dir = context.wasi_build_path / "Misc"
    pkgconfig = pathlib.PurePath("lib") / "pkgconfig"
    return [
        (
            pkgconfig / f"python-{python_version(context, debug_ok=True)}.pc",
            misc_dir / "python.pc",
        ),
        (
            pkgconfig
            / f"python-{python_version(context, debug_ok=True)}-embed.pc",
            misc_dir / "python-embed.pc",
        ),
    ]


def pkgconfig_symlinks(pkgconfig_files, context):
    assert len(pkgconfig_files) == 2
    embed, plain = (
        (0, 1) if pkgconfig_files[0].name.endswith("-embed.pc") else (1, 0)
    )
    embed_path, plain_path = pkgconfig_files[embed], pkgconfig_files[plain]
    major = context.wasi_build_details["language"]["version_info"]["major"]
    paths = [
        (embed_path.parent / f"python{major}-embed.pc", embed_path),
        (plain_path.parent / f"python{major}.pc", plain_path),
    ]
    if context.is_debug:
        paths += [
            (
                embed_path.parent
                / f"python-{python_version(context)}-embed.pc",
                embed_path,
            ),
            (
                plain_path.parent / f"python-{python_version(context)}.pc",
                plain_path,
            ),
        ]

    return paths


def pyconfig_file(context):
    """Have <build>/pyconfig.h end up in include/pythonXYd?/pyconfig.h."""
    return (
        pathlib.PurePath("include")
        / f"python{python_version(context, debug_ok=True)}"
        / "pyconfig.h",
        context.wasi_build_path / "pyconfig.h",
    )


def header_files(context):
    """Have <build>/Include/*.h end up in include/pythonXYd?/."""
    include_dir = context.checkout / "Include"
    files = []
    for root, dirs, filenames in include_dir.walk():
        for filename in filenames:
            file_path = pathlib.Path(root) / filename
            details = (
                pathlib.PurePath("include")
                / f"python{python_version(context, debug_ok=True)}"
                / file_path.relative_to(include_dir),
                file_path,
            )
            files.append(details)
    return files


def man_file(context):
    """Have Misc/python.man end up in share/man/man1/."""
    man_dir = pathlib.PurePath("share", "man", "man1")
    man_file = context.checkout / "Misc" / "python.man"
    return (
        man_dir / f"python{python_version(context)}.1",
        man_file,
    )


def man_symlink(man_path, context):
    """Symlink pythonN.M.1 to pythonN.1."""
    major = context.wasi_build_details["language"]["version_info"]["major"]
    return (man_path.parent / f"python{major}.1", man_path)


def wasmtime_config_file(context):
    """Have wasmtime.toml end up in etc/pythonXY/."""
    config = context.checkout / "Platforms" / "WASI" / "wasmtime.toml"
    return (
        pathlib.PurePath("etc")
        / f"python{python_version(context)}"
        / "wasmtime.toml",
        config,
    )


def wasm_file(context):
    """Have python.wasm end up at lib/pythonXY/lib-wasm/pythonX.Yd?.wasm."""
    return (
        lib_python(context)
        / "lib-wasm"
        / f"python{python_version(context, debug_ok=True)}.wasm",
        context.wasi_build_path / "python.wasm",
    )


def python_wasmtime_script(base, context):
    """Create bin/pythonN.Md?.wasmtime."""
    script = wasmtime_script(context)
    path = (
        base / f"bin/python{python_version(context, debug_ok=True)}.wasmtime"
    )
    path.parent.mkdir(parents=True, exist_ok=True)
    with open(path, "w") as f:
        f.write(script)
    path.chmod(0o755)

    return path


def python_wasmtime_symlink(path, context):
    """Symlink bin/pythonN.Md?.wasmtime.

    - bin/pythonN.M.wasmtime (if debug build)
    - bin/pythonN.wasmtime (if debug build)
    """
    symlinks = [
        path.parent / f"python{context.wasi_build_version['major']}.wasmtime"
    ]
    if context.is_debug:
        # The file already has the debug name, so the missing symlink is the non-debug name.
        symlinks.append(
            path.parent / f"python{python_version(context)}.wasmtime"
        )

    return [(symlink, path) for symlink in symlinks]


def config_file(context):
    """Have Misc/config.sh end up at bin/pythonN.Md?.config."""
    return (
        pathlib.PurePath("bin")
        / f"python{python_version(context, debug_ok=True)}-config",
        context.wasi_build_path / "Misc" / "python-config.sh",
    )


def config_symlink(config_path, context):
    """Symlink bin/pythonN.Md?-config.

    - bin/pythonN.M-config (if debug build)
    - bin/pythonNd?-config
    - bin/pythonN-config (if debug build)
    """
    symlinks = [
        config_path.parent
        / f"python{context.wasi_build_version['major']}-config"
    ]
    if context.is_debug:
        # The file already has the debug name, so the missing symlink is the non-debug name.
        symlinks.append(
            config_path.parent / f"python{python_version(context)}-config"
        )

    return [(symlink, config_path) for symlink in symlinks]


def copy_files(files, base):
    for dest, src in files:
        target = base / dest
        target.parent.mkdir(parents=True, exist_ok=True)
        src.copy(target)


def symlink_files(files, base):
    for target, source in files:
        target_path = base / target
        source_path = base / source
        target_path.symlink_to(
            os.path.relpath(source_path, start=target_path.parent)
        )


def gather(context):
    py_version = python_version(context)
    py_d_version = python_version(context, debug_ok=True)

    dist = context.dist_path
    if dist.exists():
        _shared.log("🧹", f"Deleting {dist} ...")
        shutil.rmtree(dist)

    indent = "  "
    base = context.archive_dir
    _shared.log("📝", f"Copying files to {base} ...")

    _shared.log("📁", "bin/", spacing=indent * 2)
    _shared.log("📄", f"python{py_d_version}-config", spacing=indent * 3)
    config_location = config_file(context)
    copy_files([config_location], base)
    symlink_files(config_symlink(config_location[0], context), base)

    _shared.log("📄", f"python{py_d_version}.wasmtime", spacing=indent * 3)
    script_path = python_wasmtime_script(base, context)
    symlink_files(python_wasmtime_symlink(script_path, context), base)

    _shared.log("📁", "etc/", spacing=indent * 2)
    _shared.log("📁", f"python{py_version}/", spacing=indent * 3)
    _shared.log("📄", "wasmtime.toml", spacing=indent * 4)
    copy_files([wasmtime_config_file(context)], base)

    _shared.log("📁", "include/", spacing=indent * 2)
    _shared.log("📁", f"python{py_version}/", spacing=indent * 3)
    _shared.log("📄", "pyconfig.h", spacing=indent * 4)
    copy_files([pyconfig_file(context)], base)
    _shared.log("📄", "**/*.h", spacing=indent * 4)
    copy_files(header_files(context), base)

    _shared.log("📁", "lib/", spacing=indent * 2)
    _shared.log("📁", f"python{py_version}/", spacing=indent * 3)
    _shared.log("📁", "lib-dynload/", spacing=indent * 4)
    (base / lib_python(context) / "lib-dynload").mkdir(
        parents=True, exist_ok=True
    )
    _shared.log("📄", "<empty>", spacing=indent * 5)

    _shared.log("📁", "lib-wasm/", spacing=indent * 4)
    _shared.log("📄", f"python{py_d_version}.wasm", spacing=indent * 5)
    copy_files([wasm_file(context)], base)
    _shared.log("📄", "LICENSE.txt", spacing=indent * 4)
    copy_files([license_file(context)], base)
    _shared.log("📄", "files in `cat pybuilddir.txt`", spacing=indent * 4)
    copy_files(build_dir_files(context), base)
    _shared.log("📄", "**/*.py", spacing=indent * 4)
    copy_files(stdlib_files(context), base)

    _shared.log("📁", "pkgconfig/", spacing=indent * 3)
    _shared.log("📄", "python*.pc", spacing=indent * 4)
    pkgconfig_paths = pkgconfig_files(context)
    copy_files(pkgconfig_paths, base)
    symlink_files(
        pkgconfig_symlinks([path for path, _ in pkgconfig_paths], context),
        base,
    )
    _shared.log("📁", "share/", spacing=indent * 2)
    _shared.log("📁", "man/", spacing=indent * 3)
    _shared.log("📁", "man1/", spacing=indent * 4)
    _shared.log("📄", "python*.1", spacing=indent * 5)
    man_path = man_file(context)
    copy_files([man_path], base)
    symlink_files([man_symlink(man_path[0], context)], base)

    return base


def archive(context):
    file_name = f"{context.archive_stem}.tar.xz"
    file_path = context.dist_path / file_name
    if file_path.exists():
        _shared.log("🧹", f"Deleting {file_path} ...")
        file_path.unlink()
    to_compress = context.archive_dir
    _shared.log("🗜️", f"Archiving to {file_path} ...")
    mtime_format = "%Y-%m-%dT%H:%M:%SZ"
    if source_date_epoch := os.environ.get("SOURCE_DATE_EPOCH"):
        mtime = datetime.datetime.fromtimestamp(
            int(source_date_epoch), datetime.UTC
        ).strftime(mtime_format)
    else:
        try:
            mtime = subprocess.run(
                [
                    "git",
                    "log",
                    "-1",
                    "--format=tformat:%cd",
                    f"--date=format:{mtime_format}",
                    os.fsdecode(context.checkout),
                ],
                env={"TZ": "UTC0"},
                capture_output=True,
                text=True,
                check=True,
            ).stdout.strip()
        except subprocess.CalledProcessError as error:
            print(error.output)
            sys.exit(error.returncode)

    try:
        subprocess.run(
            [
                "tar",
                "-c",
                "-f",
                os.fsdecode(file_path),
                "--sort=name",
                "--mtime",
                mtime,
                "--clamp-mtime",
                "--owner=0",
                "--group=0",
                "--numeric-owner",
                "--pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime",
                "--mode=go+u,go-w",
                # Explicitly using `-T` because if you don't compress with threads you can't
                # uncompress with them and the size difference is negligible when using
                # single-threaded compression.
                "--use-compress-program",
                "xz -T 0",
                to_compress.name,
            ],
            cwd=to_compress.parent,
            capture_output=True,
            text=True,
            check=True,
        )
    except subprocess.CalledProcessError as error:
        print(error.output)
        sys.exit(error.returncode)