Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/pip/_internal/utils/glibc.py: 45%

1# The following comment should be removed at some point in the future. 

2# mypy: strict-optional=False 

3 

4import os 

5import sys 

6from typing import Optional, Tuple 

7 

8 

9def glibc_version_string() -> Optional[str]: 

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

11 return glibc_version_string_confstr() or glibc_version_string_ctypes() 

12 

13 

14def glibc_version_string_confstr() -> Optional[str]: 

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

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

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

18 # platform module: 

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

20 if sys.platform == "win32": 

21 return None 

22 try: 

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

24 _, version = os.confstr("CS_GNU_LIBC_VERSION").split() 

25 except (AttributeError, OSError, ValueError): 

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

27 return None 

28 return version 

29 

30 

31def glibc_version_string_ctypes() -> Optional[str]: 

32 "Fallback implementation of glibc_version_string using ctypes." 

33 

34 try: 

35 import ctypes 

36 except ImportError: 

37 return None 

38 

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

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

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

42 # which libc our process is actually using. 

43 process_namespace = ctypes.CDLL(None) 

44 try: 

45 gnu_get_libc_version = process_namespace.gnu_get_libc_version 

46 except AttributeError: 

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

48 # glibc. 

49 return None 

50 

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

52 gnu_get_libc_version.restype = ctypes.c_char_p 

53 version_str = gnu_get_libc_version() 

54 # py2 / py3 compatibility: 

55 if not isinstance(version_str, str): 

56 version_str = version_str.decode("ascii") 

57 

58 return version_str 

59 

60 

61# platform.libc_ver regularly returns completely nonsensical glibc 

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

63# 

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

65# ('glibc', '2.7') 

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

67# ('glibc', '2.9') 

68# 

69# But the truth is: 

70# 

71# ~$ ldd --version 

72# ldd (Debian GLIBC 2.22-11) 2.22 

73# 

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

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

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

77# works. 

78def libc_ver() -> Tuple[str, str]: 

79 """Try to determine the glibc version 

80 

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

82 in case the lookup fails. 

83 """ 

84 glibc_version = glibc_version_string() 

85 if glibc_version is None: 

86 return ("", "") 

87 else: 

88 return ("glibc", glibc_version)