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"""PEP 656 support. |
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This module implements logic to detect if the currently running Python is |
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linked against musl, and what musl version is used. |
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""" |
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from __future__ import annotations |
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import functools |
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import re |
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import subprocess |
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import sys |
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from typing import Iterator, NamedTuple, Sequence |
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from ._elffile import ELFFile |
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class _MuslVersion(NamedTuple): |
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major: int |
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minor: int |
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def _parse_musl_version(output: str) -> _MuslVersion | None: |
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lines = [n for n in (n.strip() for n in output.splitlines()) if n] |
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if len(lines) < 2 or lines[0][:4] != "musl": |
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return None |
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m = re.match(r"Version (\d+)\.(\d+)", lines[1]) |
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if not m: |
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return None |
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return _MuslVersion(major=int(m.group(1)), minor=int(m.group(2))) |
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@functools.lru_cache |
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def _get_musl_version(executable: str) -> _MuslVersion | None: |
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"""Detect currently-running musl runtime version. |
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This is done by checking the specified executable's dynamic linking |
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information, and invoking the loader to parse its output for a version |
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string. If the loader is musl, the output would be something like:: |
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musl libc (x86_64) |
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Version 1.2.2 |
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Dynamic Program Loader |
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""" |
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try: |
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with open(executable, "rb") as f: |
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ld = ELFFile(f).interpreter |
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except (OSError, TypeError, ValueError): |
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return None |
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if ld is None or "musl" not in ld: |
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return None |
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proc = subprocess.run([ld], stderr=subprocess.PIPE, text=True) |
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return _parse_musl_version(proc.stderr) |
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def platform_tags(archs: Sequence[str]) -> Iterator[str]: |
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"""Generate musllinux tags compatible to the current platform. |
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:param archs: Sequence of compatible architectures. |
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The first one shall be the closest to the actual architecture and be the part of |
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platform tag after the ``linux_`` prefix, e.g. ``x86_64``. |
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The ``linux_`` prefix is assumed as a prerequisite for the current platform to |
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be musllinux-compatible. |
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:returns: An iterator of compatible musllinux tags. |
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""" |
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sys_musl = _get_musl_version(sys.executable) |
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if sys_musl is None: |
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return |
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for arch in archs: |
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for minor in range(sys_musl.minor, -1, -1): |
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yield f"musllinux_{sys_musl.major}_{minor}_{arch}" |
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if __name__ == "__main__": |
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import sysconfig |
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plat = sysconfig.get_platform() |
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assert plat.startswith("linux-"), "not linux" |
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print("plat:", plat) |
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print("musl:", _get_musl_version(sys.executable)) |
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print("tags:", end=" ") |
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for t in platform_tags(re.sub(r"[.-]", "_", plat.split("-", 1)[-1])): |
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print(t, end="\n ") |
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