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      1 # This file originally from pip:
      2 # https://github.com/pypa/pip/blob/8f4f15a5a95d7d5b511ceaee9ed261176c181970/src/pip/_internal/utils/glibc.py
      3 from __future__ import absolute_import
      4 
      5 import ctypes
      6 import re
      7 import warnings
      8 
      9 
     10 def glibc_version_string():
     11     "Returns glibc version string, or None if not using glibc."
     12 
     13     # ctypes.CDLL(None) internally calls dlopen(NULL), and as the dlopen
     14     # manpage says, "If filename is NULL, then the returned handle is for the
     15     # main program". This way we can let the linker do the work to figure out
     16     # which libc our process is actually using.
     17     process_namespace = ctypes.CDLL(None)
     18     try:
     19         gnu_get_libc_version = process_namespace.gnu_get_libc_version
     20     except AttributeError:
     21         # Symbol doesn't exist -> therefore, we are not linked to
     22         # glibc.
     23         return None
     24 
     25     # Call gnu_get_libc_version, which returns a string like "2.5"
     26     gnu_get_libc_version.restype = ctypes.c_char_p
     27     version_str = gnu_get_libc_version()
     28     # py2 / py3 compatibility:
     29     if not isinstance(version_str, str):
     30         version_str = version_str.decode("ascii")
     31 
     32     return version_str
     33 
     34 
     35 # Separated out from have_compatible_glibc for easier unit testing
     36 def check_glibc_version(version_str, required_major, minimum_minor):
     37     # Parse string and check against requested version.
     38     #
     39     # We use a regexp instead of str.split because we want to discard any
     40     # random junk that might come after the minor version -- this might happen
     41     # in patched/forked versions of glibc (e.g. Linaro's version of glibc
     42     # uses version strings like "2.20-2014.11"). See gh-3588.
     43     m = re.match(r"(?P<major>[0-9]+)\.(?P<minor>[0-9]+)", version_str)
     44     if not m:
     45         warnings.warn("Expected glibc version with 2 components major.minor,"
     46                       " got: %s" % version_str, RuntimeWarning)
     47         return False
     48     return (int(m.group("major")) == required_major and
     49             int(m.group("minor")) >= minimum_minor)
     50 
     51 
     52 def have_compatible_glibc(required_major, minimum_minor):
     53     version_str = glibc_version_string()
     54     if version_str is None:
     55         return False
     56     return check_glibc_version(version_str, required_major, minimum_minor)
     57 
     58 
     59 # platform.libc_ver regularly returns completely nonsensical glibc
     60 # versions. E.g. on my computer, platform says:
     61 #
     62 #   ~$ python2.7 -c 'import platform; print(platform.libc_ver())'
     63 #   ('glibc', '2.7')
     64 #   ~$ python3.5 -c 'import platform; print(platform.libc_ver())'
     65 #   ('glibc', '2.9')
     66 #
     67 # But the truth is:
     68 #
     69 #   ~$ ldd --version
     70 #   ldd (Debian GLIBC 2.22-11) 2.22
     71 #
     72 # This is unfortunate, because it means that the linehaul data on libc
     73 # versions that was generated by pip 8.1.2 and earlier is useless and
     74 # misleading. Solution: instead of using platform, use our code that actually
     75 # works.
     76 def libc_ver():
     77     """Try to determine the glibc version
     78 
     79     Returns a tuple of strings (lib, version) which default to empty strings
     80     in case the lookup fails.
     81     """
     82     glibc_version = glibc_version_string()
     83     if glibc_version is None:
     84         return ("", "")
     85     else:
     86         return ("glibc", glibc_version)
     87