tests/test-demandimport.py

statfs: change Linux feature detection

Previously we check three things: "statfs" function, "linux/magic.h" and
"sys/vfs.h" headers. But we didn't check "struct statfs" or the "f_type"
field. That means if a system has "statfs" but "struct statfs" is not
defined in the two header files we check, or defined without the "f_type"
field, the compilation will fail.

This patch combines the checks (2 headers + 1 function + 1 field) together
and sets "HAVE_LINUX_STATFS". It makes setup.py faster (less checks), and
more reliable (immutable to the issue above).

from __future__ import print_function

from mercurial import demandimport
demandimport.enable()

import os
import subprocess
import sys

# Only run if demandimport is allowed
if subprocess.call(['python', '%s/hghave' % os.environ['TESTDIR'],
                    'demandimport']):
    sys.exit(80)

if os.name != 'nt':
    try:
        import distutils.msvc9compiler
        print('distutils.msvc9compiler needs to be an immediate '
              'importerror on non-windows platforms')
        distutils.msvc9compiler
    except ImportError:
        pass

import re

rsub = re.sub
def f(obj):
    l = repr(obj)
    l = rsub("0x[0-9a-fA-F]+", "0x?", l)
    l = rsub("from '.*'", "from '?'", l)
    l = rsub("'<[a-z]*>'", "'<whatever>'", l)
    return l

import os

print("os =", f(os))
print("os.system =", f(os.system))
print("os =", f(os))

from mercurial import util

print("util =", f(util))
print("util.system =", f(util.system))
print("util =", f(util))
print("util.system =", f(util.system))

from mercurial import hgweb
print("hgweb =", f(hgweb))
print("hgweb_mod =", f(hgweb.hgweb_mod))
print("hgweb =", f(hgweb))

import re as fred
print("fred =", f(fred))

import sys as re
print("re =", f(re))

print("fred =", f(fred))
print("fred.sub =", f(fred.sub))
print("fred =", f(fred))

print("re =", f(re))
print("re.stderr =", f(re.stderr))
print("re =", f(re))

import contextlib
print("contextlib =", f(contextlib))
try:
    from contextlib import unknownattr
    print('no demandmod should be created for attribute of non-package '
          'module:\ncontextlib.unknownattr =', f(unknownattr))
except ImportError as inst:
    print('contextlib.unknownattr = ImportError: %s'
          % rsub(r"'", '', str(inst)))

# Unlike the import statement, __import__() function should not raise
# ImportError even if fromlist has an unknown item
# (see Python/import.c:import_module_level() and ensure_fromlist())
contextlibimp = __import__('contextlib', globals(), locals(), ['unknownattr'])
print("__import__('contextlib', ..., ['unknownattr']) =", f(contextlibimp))
print("hasattr(contextlibimp, 'unknownattr') =",
      util.safehasattr(contextlibimp, 'unknownattr'))

demandimport.disable()
os.environ['HGDEMANDIMPORT'] = 'disable'
# this enable call should not actually enable demandimport!
demandimport.enable()
from mercurial import node
print("node =", f(node))