from __future__ import absolute_import
import re
import ctypes
import platform
import warnings
def glibc_version_string():
"Returns glibc version string, or None if not using glibc."
# ctypes.CDLL(None) internally calls dlopen(NULL), and as the dlopen
# manpage says, "If filename is NULL, then the returned handle is for the
# main program". This way we can let the linker do the work to figure out
# which libc our process is actually using.
process_namespace = ctypes.CDLL(None)
try:
gnu_get_libc_version = process_namespace.gnu_get_libc_version
except AttributeError:
# Symbol doesn't exist -> therefore, we are not linked to
# glibc.
return None
# Call gnu_get_libc_version, which returns a string like "2.5"
gnu_get_libc_version.restype = ctypes.c_char_p
version_str = gnu_get_libc_version()
# py2 / py3 compatibility:
if not isinstance(version_str, str):
version_str = version_str.decode("ascii")
return version_str
# Separated out from have_compatible_glibc for easier unit testing
def check_glibc_version(version_str, required_major, minimum_minor):
# Parse string and check against requested version.
#
# We use a regexp instead of str.split because we want to discard any
# random junk that might come after the minor version -- this might happen
# in patched/forked versions of glibc (e.g. Linaro's version of glibc
# uses version strings like "2.20-2014.11"). See gh-3588.
m = re.match(r"(?P<major>[0-9]+)\.(?P<minor>[0-9]+)", version_str)
if not m:
warnings.warn("Expected glibc version with 2 components major.minor,"
" got: %s" % version_str, RuntimeWarning)
return False
return (int(m.group("major")) == required_major and
int(m.group("minor")) >= minimum_minor)
def have_compatible_glibc(required_major, minimum_minor):
version_str = glibc_version_string()
if version_str is None:
return False
return check_glibc_version(version_str, required_major, minimum_minor)
# platform.libc_ver regularly returns completely nonsensical glibc
# versions. E.g. on my computer, platform says:
#
# ~$ python2.7 -c 'import platform; print(platform.libc_ver())'
# ('glibc', '2.7')
# ~$ python3.5 -c 'import platform; print(platform.libc_ver())'
# ('glibc', '2.9')
#
# But the truth is:
#
# ~$ ldd --version
# ldd (Debian GLIBC 2.22-11) 2.22
#
# This is unfortunate, because it means that the linehaul data on libc
# versions that was generated by pip 8.1.2 and earlier is useless and
# misleading. Solution: instead of using platform, use our code that actually
# works.
def libc_ver():
glibc_version = glibc_version_string()
if glibc_version is None:
# For non-glibc platforms, fall back on platform.libc_ver
return platform.libc_ver()
else:
return ("glibc", glibc_version)
