Pull in ~pristine copies of pep425tags/glibc from our vendored setupt…

…ools.

pex/glibc.py

@@ -1,61 +1,64 @@
-# This file was copied from the pip project master branch on 2016/12/05
+# NB: Copied from our vendored setuptools' version at:
+#   pex/vendor/_vendored/setuptools/setuptools/glibc.py
+# Modifications are marked with `# NB: Modified from ...`
 
+# This file originally from pip:
+# https://github.com/pypa/pip/blob/8f4f15a5a95d7d5b511ceaee9ed261176c181970/src/pip/_internal/utils/glibc.py
 from __future__ import absolute_import
 
 import ctypes
-import platform
 import re
-
-from pex import pex_warnings
+from pex import pex_warnings  # NB: Modified from `import warnings`
 
 
 def glibc_version_string():
-  "Returns glibc version string, or None if not using glibc."
+    "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
+    # 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")
+    # 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
+    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:
-    pex_warnings.warn("Expected glibc version with 2 components major.minor,"
-                      " got: %s" % version_str)
-    return False
-  return (int(m.group("major")) == required_major and
-          int(m.group("minor")) >= 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:
+        # NB: Modified from `warnings.warn(..., RuntimeError)`
+        pex_warnings.warn("Expected glibc version with 2 components major.minor,"
+                          " got: %s" % version_str)
+        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)
+    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
@@ -76,9 +79,13 @@ def have_compatible_glibc(required_major, minimum_minor):
 # 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)
+    """Try to determine the glibc version
+
+    Returns a tuple of strings (lib, version) which default to empty strings
+    in case the lookup fails.
+    """
+    glibc_version = glibc_version_string()
+    if glibc_version is None:
+        return ("", "")
+    else:
+        return ("glibc", glibc_version)