Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/packaging/_musllinux.py: 38%

1"""PEP 656 support. 

2 

3This module implements logic to detect if the currently running Python is 

4linked against musl, and what musl version is used. 

5""" 

6 

7import functools 

8import re 

9import subprocess 

10import sys 

11from typing import Iterator, NamedTuple, Optional 

12 

13from ._elffile import ELFFile 

14 

15 

16class _MuslVersion(NamedTuple): 

17 major: int 

18 minor: int 

19 

20 

21def _parse_musl_version(output: str) -> Optional[_MuslVersion]: 

22 lines = [n for n in (n.strip() for n in output.splitlines()) if n] 

23 if len(lines) < 2 or lines[0][:4] != "musl": 

24 return None 

25 m = re.match(r"Version (\d+)\.(\d+)", lines[1]) 

26 if not m: 

27 return None 

28 return _MuslVersion(major=int(m.group(1)), minor=int(m.group(2))) 

29 

30 

31@functools.lru_cache() 

32def _get_musl_version(executable: str) -> Optional[_MuslVersion]: 

33 """Detect currently-running musl runtime version. 

34 

35 This is done by checking the specified executable's dynamic linking 

36 information, and invoking the loader to parse its output for a version 

37 string. If the loader is musl, the output would be something like:: 

38 

39 musl libc (x86_64) 

40 Version 1.2.2 

41 Dynamic Program Loader 

42 """ 

43 try: 

44 with open(executable, "rb") as f: 

45 ld = ELFFile(f).interpreter 

46 except (OSError, TypeError, ValueError): 

47 return None 

48 if ld is None or "musl" not in ld: 

49 return None 

50 proc = subprocess.run([ld], stderr=subprocess.PIPE, universal_newlines=True) 

51 return _parse_musl_version(proc.stderr) 

52 

53 

54def platform_tags(arch: str) -> Iterator[str]: 

55 """Generate musllinux tags compatible to the current platform. 

56 

57 :param arch: Should be the part of platform tag after the ``linux_`` 

58 prefix, e.g. ``x86_64``. The ``linux_`` prefix is assumed as a 

59 prerequisite for the current platform to be musllinux-compatible. 

60 

61 :returns: An iterator of compatible musllinux tags. 

62 """ 

63 sys_musl = _get_musl_version(sys.executable) 

64 if sys_musl is None: # Python not dynamically linked against musl. 

65 return 

66 for minor in range(sys_musl.minor, -1, -1): 

67 yield f"musllinux_{sys_musl.major}_{minor}_{arch}" 

68 

69 

70if __name__ == "__main__": # pragma: no cover 

71 import sysconfig 

72 

73 plat = sysconfig.get_platform() 

74 assert plat.startswith("linux-"), "not linux" 

75 

76 print("plat:", plat) 

77 print("musl:", _get_musl_version(sys.executable)) 

78 print("tags:", end=" ") 

79 for t in platform_tags(re.sub(r"[.-]", "_", plat.split("-", 1)[-1])): 

80 print(t, end="\n ")