Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/pip/_internal/utils/glibc.py: 44%

1from __future__ import annotations 

2 

3import os 

4import sys 

5 

6 

7def glibc_version_string() -> str | None: 

8 "Returns glibc version string, or None if not using glibc." 

9 return glibc_version_string_confstr() or glibc_version_string_ctypes() 

10 

11 

12def glibc_version_string_confstr() -> str | None: 

13 "Primary implementation of glibc_version_string using os.confstr." 

14 # os.confstr is quite a bit faster than ctypes.DLL. It's also less likely 

15 # to be broken or missing. This strategy is used in the standard library 

16 # platform module: 

17 # https://github.com/python/cpython/blob/fcf1d003bf4f0100c9d0921ff3d70e1127ca1b71/Lib/platform.py#L175-L183 

18 if sys.platform == "win32": 

19 return None 

20 try: 

21 gnu_libc_version = os.confstr("CS_GNU_LIBC_VERSION") 

22 if gnu_libc_version is None: 

23 return None 

24 # os.confstr("CS_GNU_LIBC_VERSION") returns a string like "glibc 2.17": 

25 _, version = gnu_libc_version.split() 

26 except (AttributeError, OSError, ValueError): 

27 # os.confstr() or CS_GNU_LIBC_VERSION not available (or a bad value)... 

28 return None 

29 return version 

30 

31 

32def glibc_version_string_ctypes() -> str | None: 

33 "Fallback implementation of glibc_version_string using ctypes." 

34 

35 try: 

36 import ctypes 

37 except ImportError: 

38 return None 

39 

40 # ctypes.CDLL(None) internally calls dlopen(NULL), and as the dlopen 

41 # manpage says, "If filename is NULL, then the returned handle is for the 

42 # main program". This way we can let the linker do the work to figure out 

43 # which libc our process is actually using. 

44 # 

45 # We must also handle the special case where the executable is not a 

46 # dynamically linked executable. This can occur when using musl libc, 

47 # for example. In this situation, dlopen() will error, leading to an 

48 # OSError. Interestingly, at least in the case of musl, there is no 

49 # errno set on the OSError. The single string argument used to construct 

50 # OSError comes from libc itself and is therefore not portable to 

51 # hard code here. In any case, failure to call dlopen() means we 

52 # can't proceed, so we bail on our attempt. 

53 try: 

54 process_namespace = ctypes.CDLL(None) 

55 except OSError: 

56 return None 

57 

58 try: 

59 gnu_get_libc_version = process_namespace.gnu_get_libc_version 

60 except AttributeError: 

61 # Symbol doesn't exist -> therefore, we are not linked to 

62 # glibc. 

63 return None 

64 

65 # Call gnu_get_libc_version, which returns a string like "2.5" 

66 gnu_get_libc_version.restype = ctypes.c_char_p 

67 version_str: str = gnu_get_libc_version() 

68 # py2 / py3 compatibility: 

69 if not isinstance(version_str, str): 

70 version_str = version_str.decode("ascii") 

71 

72 return version_str 

73 

74 

75# platform.libc_ver regularly returns completely nonsensical glibc 

76# versions. E.g. on my computer, platform says: 

77# 

78# ~$ python2.7 -c 'import platform; print(platform.libc_ver())' 

79# ('glibc', '2.7') 

80# ~$ python3.5 -c 'import platform; print(platform.libc_ver())' 

81# ('glibc', '2.9') 

82# 

83# But the truth is: 

84# 

85# ~$ ldd --version 

86# ldd (Debian GLIBC 2.22-11) 2.22 

87# 

88# This is unfortunate, because it means that the linehaul data on libc 

89# versions that was generated by pip 8.1.2 and earlier is useless and 

90# misleading. Solution: instead of using platform, use our code that actually 

91# works. 

92def libc_ver() -> tuple[str, str]: 

93 """Try to determine the glibc version 

94 

95 Returns a tuple of strings (lib, version) which default to empty strings 

96 in case the lookup fails. 

97 """ 

98 glibc_version = glibc_version_string() 

99 if glibc_version is None: 

100 return ("", "") 

101 else: 

102 return ("glibc", glibc_version)