bpo-46633: Skip tests on ASAN and/or MSAN builds (GH-31632)

Skip tests on ASAN and/or MSAN builds:

* multiprocessing tests
* test___all__
* test_concurrent_futures
* test_decimal
* test_peg_generator
* test_tools

The ASAN job of GitHub Actions no longer excludes these tests.

.github/workflows/build.yml

@@ -306,12 +306,4 @@ jobs:
     - name: Display build info
       run: make pythoninfo
     - name: Tests
-      # Skip test_tools test_peg_generator test_concurrent_futures because
-      # there are too slow: between 5 and 20 minutes on this CI.
-      #
-      # Skip multiprocessing and concurrent.futures tests which are affected by
-      # bpo-45200 bug: libasan dead lock in pthread_create().
-      #
-      # test___all__ is skipped because importing some modules directly can trigger
-      # known problems with ASAN (like tk or crypt).
-      run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu -x test___all__ test_multiprocessing_fork test_multiprocessing_forkserver test_multiprocessing_spawn test_tools test_peg_generator test_concurrent_futures"
+      run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"

Lib/test/_test_multiprocessing.py

@@ -73,6 +73,12 @@ except ImportError:
     msvcrt = None
 
 
+if support.check_sanitizer(address=True):
+    # bpo-45200: Skip multiprocessing tests if Python is built with ASAN to
+    # work around a libasan race condition: dead lock in pthread_create().
+    raise unittest.SkipTest("libasan has a pthread_create() dead lock")
+
+
 def latin(s):
     return s.encode('latin')
 

Lib/test/test___all__.py

@@ -11,6 +11,13 @@ except ModuleNotFoundError:
     _multiprocessing = None
 
 
+if support.check_sanitizer(address=True, memory=True):
+    # bpo-46633: test___all__ is skipped because importing some modules
+    # directly can trigger known problems with ASAN (like tk or crypt).
+    raise unittest.SkipTest("workaround ASAN build issues on loading tests "
+                            "like tk or crypt")
+
+
 class NoAll(RuntimeError):
     pass
 

Lib/test/test_concurrent_futures.py

@@ -32,6 +32,12 @@ import multiprocessing.process
 import multiprocessing.util
 
 
+if support.check_sanitizer(address=True, memory=True):
+    # bpo-46633: Skip the test because it is too slow when Python is built
+    # with ASAN/MSAN: between 5 and 20 minutes on GitHub Actions.
+    raise unittest.SkipTest("test too slow on ASAN/MSAN build")
+
+
 def create_future(state=PENDING, exception=None, result=None):
     f = Future()
     f._state = state

Lib/test/test_decimal.py

@@ -34,7 +34,7 @@ import numbers
 import locale
 from test.support import (run_unittest, run_doctest, is_resource_enabled,
                           requires_IEEE_754, requires_docstrings,
-                          requires_legacy_unicode_capi)
+                          requires_legacy_unicode_capi, check_sanitizer)
 from test.support import (TestFailed,
                           run_with_locale, cpython_only,
                           darwin_malloc_err_warning)
@@ -43,17 +43,6 @@ from test.support import warnings_helper
 import random
 import inspect
 import threading
-import sysconfig
-_cflags = sysconfig.get_config_var('CFLAGS') or ''
-_config_args = sysconfig.get_config_var('CONFIG_ARGS') or ''
-MEMORY_SANITIZER = (
-    '-fsanitize=memory' in _cflags or
-    '--with-memory-sanitizer' in _config_args
-)
-
-ADDRESS_SANITIZER = (
-    '-fsanitize=address' in _cflags
-)
 
 
 if sys.platform == 'darwin':
@@ -5518,7 +5507,8 @@ class CWhitebox(unittest.TestCase):
     # Issue 41540:
     @unittest.skipIf(sys.platform.startswith("aix"),
                      "AIX: default ulimit: test is flaky because of extreme over-allocation")
-    @unittest.skipIf(MEMORY_SANITIZER or ADDRESS_SANITIZER, "sanitizer defaults to crashing "
+    @unittest.skipIf(check_sanitizer(address=True, memory=True),
+                     "ASAN/MSAN sanitizer defaults to crashing "
                      "instead of returning NULL for malloc failure.")
     def test_maxcontext_exact_arith(self):
 

Lib/test/test_peg_generator/__init__.py

@@ -1,7 +1,15 @@
-import os
-
+import os.path
+import unittest
+from test import support
 from test.support import load_package_tests
 
+
+if support.check_sanitizer(address=True, memory=True):
+    # bpo-46633: Skip the test because it is too slow when Python is built
+    # with ASAN/MSAN: between 5 and 20 minutes on GitHub Actions.
+    raise unittest.SkipTest("test too slow on ASAN/MSAN build")
+
+
 # Load all tests in package
 def load_tests(*args):
     return load_package_tests(os.path.dirname(__file__), *args)

Lib/test/test_tools/__init__.py

@@ -6,6 +6,13 @@ import unittest
 from test import support
 from test.support import import_helper
 
+
+if support.check_sanitizer(address=True, memory=True):
+    # bpo-46633: Skip the test because it is too slow when Python is built
+    # with ASAN/MSAN: between 5 and 20 minutes on GitHub Actions.
+    raise unittest.SkipTest("test too slow on ASAN/MSAN build")
+
+
 basepath = os.path.normpath(
         os.path.dirname(                 # <src/install dir>
             os.path.dirname(                # Lib