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lib2to3.pgen3.driver.load_grammar() now creates a stable cache file

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between runs given the same Grammar.txt input regardless of the hash
randomization setting.
This commit is contained in:
Gregory P. Smith ext:(%20%5BGoogle%20Inc.%5D) 2016-09-08 00:46:26 +00:00
commit 0c578d62fc
6 changed files with 116 additions and 16 deletions
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71
Lib/lib2to3/tests/test_parser.py
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@ -15,11 +15,15 @@ from test.support import verbose
# Python imports
import os
import shutil
import subprocess
import sys
import tempfile
import unittest
import warnings
import subprocess
# Local imports
from lib2to3.pgen2 import driver as pgen2_driver
from lib2to3.pgen2 import tokenize
from ..pgen2.parse import ParseError
from lib2to3.pygram import python_symbols as syms
@ -34,6 +38,71 @@ class TestDriver(support.TestCase):
self.assertEqual(t.children[1].children[0].type, syms.print_stmt)
class TestPgen2Caching(support.TestCase):
def test_load_grammar_from_txt_file(self):
pgen2_driver.load_grammar(support.grammar_path, save=False, force=True)
def test_load_grammar_from_pickle(self):
# Make a copy of the grammar file in a temp directory we are
# guaranteed to be able to write to.
tmpdir = tempfile.mkdtemp()
try:
grammar_copy = os.path.join(
tmpdir, os.path.basename(support.grammar_path))
shutil.copy(support.grammar_path, grammar_copy)
pickle_name = pgen2_driver._generate_pickle_name(grammar_copy)
pgen2_driver.load_grammar(grammar_copy, save=True, force=True)
self.assertTrue(os.path.exists(pickle_name))
os.unlink(grammar_copy) # Only the pickle remains...
pgen2_driver.load_grammar(grammar_copy, save=False, force=False)
finally:
shutil.rmtree(tmpdir)
@unittest.skipIf(sys.executable is None, 'sys.executable required')
def test_load_grammar_from_subprocess(self):
tmpdir = tempfile.mkdtemp()
tmpsubdir = os.path.join(tmpdir, 'subdir')
try:
os.mkdir(tmpsubdir)
grammar_base = os.path.basename(support.grammar_path)
grammar_copy = os.path.join(tmpdir, grammar_base)
grammar_sub_copy = os.path.join(tmpsubdir, grammar_base)
shutil.copy(support.grammar_path, grammar_copy)
shutil.copy(support.grammar_path, grammar_sub_copy)
pickle_name = pgen2_driver._generate_pickle_name(grammar_copy)
pickle_sub_name = pgen2_driver._generate_pickle_name(
grammar_sub_copy)
self.assertNotEqual(pickle_name, pickle_sub_name)
# Generate a pickle file from this process.
pgen2_driver.load_grammar(grammar_copy, save=True, force=True)
self.assertTrue(os.path.exists(pickle_name))
# Generate a new pickle file in a subprocess with a most likely
# different hash randomization seed.
sub_env = dict(os.environ)
sub_env['PYTHONHASHSEED'] = 'random'
subprocess.check_call(
[sys.executable, '-c', """
from lib2to3.pgen2 import driver as pgen2_driver
pgen2_driver.load_grammar(%r, save=True, force=True)
""" % (grammar_sub_copy,)],
env=sub_env)
self.assertTrue(os.path.exists(pickle_sub_name))
with open(pickle_name, 'rb') as pickle_f_1, \
open(pickle_sub_name, 'rb') as pickle_f_2:
self.assertEqual(
pickle_f_1.read(), pickle_f_2.read(),
msg='Grammar caches generated using different hash seeds'
' were not identical.')
finally:
shutil.rmtree(tmpdir)
class GrammarTest(support.TestCase):
def validate(self, code):
support.parse_string(code)