Synchronize libregrtest from master to 3.6 (#2244)

* bpo-30523: regrtest: Add --list-cases option (#2238)
* bpo-30284: Fix regrtest for out of tree build (#1481)
* bpo-30540: regrtest: add --matchfile option (#1909)
* bpo-30258: regrtest: Fix run_tests_multiprocess() (#1479)
* bpo-30263: regrtest: log system load (#1452)

7 files changed, 228 insertions, 58 deletions

diff --git a/Lib/test/libregrtest/cmdline.py b/Lib/test/libregrtest/cmdline.py
index cdbd1b8b925..bf64062ef96 100644
--- a/Lib/test/libregrtest/cmdline.py
+++ b/Lib/test/libregrtest/cmdline.py
@@ -117,6 +117,13 @@ resources to test.  Currently only the following are defined:
 To enable all resources except one, use '-uall,-<resource>'.  For
 example, to run all the tests except for the gui tests, give the
 option '-uall,-gui'.
+
+--matchfile filters tests using a text file, one pattern per line.
+Pattern examples:
+
+- test method: test_stat_attributes
+- test class: FileTests
+- test identifier: test_os.FileTests.test_stat_attributes
 """
 
 
@@ -189,8 +196,12 @@ def _create_parser():
                        help='single step through a set of tests.' +
                             more_details)
     group.add_argument('-m', '--match', metavar='PAT',
-                       dest='match_tests',
+                       dest='match_tests', action='append',
                        help='match test cases and methods with glob pattern PAT')
+    group.add_argument('--matchfile', metavar='FILENAME',
+                       dest='match_filename',
+                       help='similar to --match but get patterns from a '
+                            'text file, one pattern per line')
     group.add_argument('-G', '--failfast', action='store_true',
                        help='fail as soon as a test fails (only with -v or -W)')
     group.add_argument('-u', '--use', metavar='RES1,RES2,...',
@@ -239,6 +250,9 @@ def _create_parser():
     group.add_argument('--list-tests', action='store_true',
                        help="only write the name of tests that will be run, "
                             "don't execute them")
+    group.add_argument('--list-cases', action='store_true',
+                       help='only write the name of test cases that will be run'
+                            ' , don\'t execute them')
     group.add_argument('-P', '--pgo', dest='pgo', action='store_true',
                        help='enable Profile Guided Optimization training')
 
@@ -343,10 +357,19 @@ def _parse_args(args, **kwargs):
                     ns.use_resources.append(r)
     if ns.random_seed is not None:
         ns.randomize = True
+    if ns.verbose:
+        ns.header = True
     if ns.huntrleaks and ns.verbose3:
         ns.verbose3 = False
         print("WARNING: Disable --verbose3 because it's incompatible with "
               "--huntrleaks: see http://bugs.python.org/issue27103",
               file=sys.stderr)
+    if ns.match_filename:
+        if ns.match_tests is None:
+            ns.match_tests = []
+        filename = os.path.join(support.SAVEDCWD, ns.match_filename)
+        with open(filename) as fp:
+            for line in fp:
+                ns.match_tests.append(line.strip())
 
     return ns
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
index f0effc973c1..527de177792 100644
--- a/Lib/test/libregrtest/main.py
+++ b/Lib/test/libregrtest/main.py
@@ -10,9 +10,10 @@ import sysconfig
 import tempfile
 import textwrap
 import time
+import unittest
 from test.libregrtest.cmdline import _parse_args
 from test.libregrtest.runtest import (
-    findtests, runtest,
+    findtests, runtest, get_abs_module,
     STDTESTS, NOTTESTS, PASSED, FAILED, ENV_CHANGED, SKIPPED, RESOURCE_DENIED,
     INTERRUPTED, CHILD_ERROR,
     PROGRESS_MIN_TIME, format_test_result)
@@ -28,7 +29,13 @@ except ImportError:
 # to keep the test files in a subfolder.  This eases the cleanup of leftover
 # files using the "make distclean" command.
 if sysconfig.is_python_build():
-    TEMPDIR = os.path.join(sysconfig.get_config_var('srcdir'), 'build')
+    TEMPDIR = sysconfig.get_config_var('abs_builddir')
+    if TEMPDIR is None:
+        # bpo-30284: On Windows, only srcdir is available. Using abs_builddir
+        # mostly matters on UNIX when building Python out of the source tree,
+        # especially when the source tree is read only.
+        TEMPDIR = sysconfig.get_config_var('srcdir')
+    TEMPDIR = os.path.join(TEMPDIR, 'build')
 else:
     TEMPDIR = tempfile.gettempdir()
 TEMPDIR = os.path.abspath(TEMPDIR)
@@ -107,7 +114,7 @@ class Regrtest:
             self.test_times.append((test_time, test))
         if ok == PASSED:
             self.good.append(test)
-        elif ok == FAILED:
+        elif ok in (FAILED, CHILD_ERROR):
             self.bad.append(test)
         elif ok == ENV_CHANGED:
             self.environment_changed.append(test)
@@ -116,22 +123,28 @@ class Regrtest:
         elif ok == RESOURCE_DENIED:
             self.skipped.append(test)
             self.resource_denieds.append(test)
+        elif ok != INTERRUPTED:
+            raise ValueError("invalid test result: %r" % ok)
 
     def display_progress(self, test_index, test):
         if self.ns.quiet:
             return
+
+        # "[ 51/405/1] test_tcl passed"
+        line = f"{test_index:{self.test_count_width}}{self.test_count}"
         if self.bad and not self.ns.pgo:
-            fmt = "{time} [{test_index:{count_width}}{test_count}/{nbad}] {test_name}"
-        else:
-            fmt = "{time} [{test_index:{count_width}}{test_count}] {test_name}"
+            line = f"{line}/{len(self.bad)}"
+        line = f"[{line}] {test}"
+
+        # add the system load prefix: "load avg: 1.80 "
+        if hasattr(os, 'getloadavg'):
+            load_avg_1min = os.getloadavg()[0]
+            line = f"load avg: {load_avg_1min:.2f} {line}"
+
+        # add the timestamp prefix:  "0:01:05 "
         test_time = time.monotonic() - self.start_time
         test_time = datetime.timedelta(seconds=int(test_time))
-        line = fmt.format(count_width=self.test_count_width,
-                          test_index=test_index,
-                          test_count=self.test_count,
-                          nbad=len(self.bad),
-                          test_name=test,
-                          time=test_time)
+        line = f"{test_time} {line}"
         print(line, flush=True)
 
     def parse_args(self, kwargs):
@@ -179,19 +192,14 @@ class Regrtest:
             self.tests = []
             # regex to match 'test_builtin' in line:
             # '0:00:00 [  4/400] test_builtin -- test_dict took 1 sec'
-            regex = (r'^(?:[0-9]+:[0-9]+:[0-9]+ *)?'
-                     r'(?:\[[0-9/ ]+\] *)?'
-                     r'(test_[a-zA-Z0-9_]+)')
-            regex = re.compile(regex)
+            regex = re.compile(r'\btest_[a-zA-Z0-9_]+\b')
             with open(os.path.join(support.SAVEDCWD, self.ns.fromfile)) as fp:
                 for line in fp:
+                    line = line.split('#', 1)[0]
                     line = line.strip()
-                    if line.startswith('#'):
-                        continue
-                    match = regex.match(line)
-                    if match is None:
-                        continue
-                    self.tests.append(match.group(1))
+                    match = regex.search(line)
+                    if match is not None:
+                        self.tests.append(match.group())
 
         removepy(self.tests)
 
@@ -241,6 +249,29 @@ class Regrtest:
         for name in self.selected:
             print(name)
 
+    def _list_cases(self, suite):
+        for test in suite:
+            if isinstance(test, unittest.loader._FailedTest):
+                continue
+            if isinstance(test, unittest.TestSuite):
+                self._list_cases(test)
+            elif isinstance(test, unittest.TestCase):
+                print(test.id())
+
+    def list_cases(self):
+        for test in self.selected:
+            abstest = get_abs_module(self.ns, test)
+            try:
+                suite = unittest.defaultTestLoader.loadTestsFromName(abstest)
+                self._list_cases(suite)
+            except unittest.SkipTest:
+                self.skipped.append(test)
+
+        if self.skipped:
+            print(file=sys.stderr)
+            print(count(len(self.skipped), "test"), "skipped:", file=sys.stderr)
+            printlist(self.skipped, file=sys.stderr)
+
     def rerun_failed_tests(self):
         self.ns.verbose = True
         self.ns.failfast = False
@@ -381,23 +412,28 @@ class Regrtest:
                 if self.bad:
                     return
 
+    def display_header(self):
+        # Print basic platform information
+        print("==", platform.python_implementation(), *sys.version.split())
+        print("==", platform.platform(aliased=True),
+                      "%s-endian" % sys.byteorder)
+        print("== hash algorithm:", sys.hash_info.algorithm,
+              "64bit" if sys.maxsize > 2**32 else "32bit")
+        print("== cwd:", os.getcwd())
+        cpu_count = os.cpu_count()
+        if cpu_count:
+            print("== CPU count:", cpu_count)
+        print("== encodings: locale=%s, FS=%s"
+              % (locale.getpreferredencoding(False),
+                 sys.getfilesystemencoding()))
+        print("Testing with flags:", sys.flags)
+
     def run_tests(self):
         # For a partial run, we do not need to clutter the output.
-        if (self.ns.verbose
-            or self.ns.header
-            or not (self.ns.pgo or self.ns.quiet or self.ns.single
-                    or self.tests or self.ns.args)):
-            # Print basic platform information
-            print("==", platform.python_implementation(), *sys.version.split())
-            print("==  ", platform.platform(aliased=True),
-                          "%s-endian" % sys.byteorder)
-            print("==  ", "hash algorithm:", sys.hash_info.algorithm,
-                  "64bit" if sys.maxsize > 2**32 else "32bit")
-            print("==  cwd:", os.getcwd())
-            print("==  encodings: locale=%s, FS=%s"
-                  % (locale.getpreferredencoding(False),
-                     sys.getfilesystemencoding()))
-            print("Testing with flags:", sys.flags)
+        if (self.ns.header
+            or not(self.ns.pgo or self.ns.quiet or self.ns.single
+                   or self.tests or self.ns.args)):
+            self.display_header()
 
         if self.ns.randomize:
             print("Using random seed", self.ns.random_seed)
@@ -487,6 +523,10 @@ class Regrtest:
             self.list_tests()
             sys.exit(0)
 
+        if self.ns.list_cases:
+            self.list_cases()
+            sys.exit(0)
+
         self.run_tests()
         self.display_result()
 
@@ -513,7 +553,7 @@ def count(n, word):
         return "%d %ss" % (n, word)
 
 
-def printlist(x, width=70, indent=4):
+def printlist(x, width=70, indent=4, file=None):
     """Print the elements of iterable x to stdout.
 
     Optional arg width (default 70) is the maximum line length.
@@ -524,7 +564,8 @@ def printlist(x, width=70, indent=4):
     blanks = ' ' * indent
     # Print the sorted list: 'x' may be a '--random' list or a set()
     print(textwrap.fill(' '.join(str(elt) for elt in sorted(x)), width,
-                        initial_indent=blanks, subsequent_indent=blanks))
+                        initial_indent=blanks, subsequent_indent=blanks),
+          file=file)
 
 
 def main(tests=None, **kwargs):
diff --git a/Lib/test/libregrtest/refleak.py b/Lib/test/libregrtest/refleak.py
index e2e58bd872f..c69fc0f1477 100644
--- a/Lib/test/libregrtest/refleak.py
+++ b/Lib/test/libregrtest/refleak.py
@@ -84,7 +84,7 @@ def dash_R(the_module, test, indirect_test, huntrleaks):
         indirect_test()
         alloc_after, rc_after, fd_after = dash_R_cleanup(fs, ps, pic, zdc,
                                                          abcs)
-        print('.', end='', flush=True)
+        print('.', end='', file=sys.stderr, flush=True)
         if i >= nwarmup:
             rc_deltas[i] = rc_after - rc_before
             alloc_deltas[i] = alloc_after - alloc_before
diff --git a/Lib/test/libregrtest/runtest.py b/Lib/test/libregrtest/runtest.py
index ba0df0a317a..fda4ca1ebca 100644
--- a/Lib/test/libregrtest/runtest.py
+++ b/Lib/test/libregrtest/runtest.py
@@ -71,6 +71,14 @@ def findtests(testdir=None, stdtests=STDTESTS, nottests=NOTTESTS):
     return stdtests + sorted(tests)
 
 
+def get_abs_module(ns, test):
+    if test.startswith('test.') or ns.testdir:
+        return test
+    else:
+        # Always import it from the test package
+        return 'test.' + test
+
+
 def runtest(ns, test):
     """Run a single test.
 
@@ -141,11 +149,7 @@ def runtest_inner(ns, test, display_failure=True):
     test_time = 0.0
     refleak = False  # True if the test leaked references.
     try:
-        if test.startswith('test.') or ns.testdir:
-            abstest = test
-        else:
-            # Always import it from the test package
-            abstest = 'test.' + test
+        abstest = get_abs_module(ns, test)
         clear_caches()
         with saved_test_environment(test, ns.verbose, ns.quiet, pgo=ns.pgo) as environment:
             start_time = time.time()
diff --git a/Lib/test/libregrtest/runtest_mp.py b/Lib/test/libregrtest/runtest_mp.py
index 9604c166009..779ff01a649 100644
--- a/Lib/test/libregrtest/runtest_mp.py
+++ b/Lib/test/libregrtest/runtest_mp.py
@@ -41,7 +41,7 @@ def run_test_in_subprocess(testname, ns):
     slaveargs = json.dumps(slaveargs)
 
     cmd = [sys.executable, *support.args_from_interpreter_flags(),
-           '-X', 'faulthandler',
+           '-u',    # Unbuffered stdout and stderr
            '-m', 'test.regrtest',
            '--slaveargs', slaveargs]
     if ns.pgo:
@@ -124,13 +124,13 @@ class MultiprocessThread(threading.Thread):
         finally:
             self.current_test = None
 
-        stdout, _, result = stdout.strip().rpartition("\n")
         if retcode != 0:
             result = (CHILD_ERROR, "Exit code %s" % retcode)
             self.output.put((test, stdout.rstrip(), stderr.rstrip(),
                              result))
-            return True
+            return False
 
+        stdout, _, result = stdout.strip().rpartition("\n")
         if not result:
             self.output.put((None, None, None, None))
             return True
@@ -203,6 +203,8 @@ def run_tests_multiprocess(regrtest):
                 and test_time >= PROGRESS_MIN_TIME
                 and not regrtest.ns.pgo):
                 text += ' (%.0f sec)' % test_time
+            elif ok == CHILD_ERROR:
+                text = '%s (%s)' % (text, test_time)
             running = get_running(workers)
             if running and not regrtest.ns.pgo:
                 text += ' -- running: %s' % ', '.join(running)
@@ -216,9 +218,6 @@ def run_tests_multiprocess(regrtest):
 
             if result[0] == INTERRUPTED:
                 raise KeyboardInterrupt
-            if result[0] == CHILD_ERROR:
-                msg = "Child error on {}: {}".format(test, result[1])
-                raise Exception(msg)
             test_index += 1
     except KeyboardInterrupt:
         regrtest.interrupted = True
diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index f8d177990bf..be926ea6c71 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -1915,9 +1915,15 @@ def run_unittest(*classes):
     def case_pred(test):
         if match_tests is None:
             return True
-        for name in test.id().split("."):
-            if fnmatch.fnmatchcase(name, match_tests):
+        test_id = test.id()
+
+        for match_test in match_tests:
+            if fnmatch.fnmatchcase(test_id, match_test):
                 return True
+
+            for name in test_id.split("."):
+                if fnmatch.fnmatchcase(name, match_test):
+                    return True
         return False
     _filter_suite(suite, case_pred)
     _run_suite(suite)
diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
index 751df1537d2..5c6154a347d 100644
--- a/Lib/test/test_regrtest.py
+++ b/Lib/test/test_regrtest.py
@@ -118,6 +118,9 @@ class ParseArgsTestCase(unittest.TestCase):
         ns = libregrtest._parse_args(['--header'])
         self.assertTrue(ns.header)
 
+        ns = libregrtest._parse_args(['--verbose'])
+        self.assertTrue(ns.header)
+
     def test_randomize(self):
         for opt in '-r', '--randomize':
             with self.subTest(opt=opt):
@@ -156,9 +159,24 @@ class ParseArgsTestCase(unittest.TestCase):
         for opt in '-m', '--match':
             with self.subTest(opt=opt):
                 ns = libregrtest._parse_args([opt, 'pattern'])
-                self.assertEqual(ns.match_tests, 'pattern')
+                self.assertEqual(ns.match_tests, ['pattern'])
                 self.checkError([opt], 'expected one argument')
 
+        ns = libregrtest._parse_args(['-m', 'pattern1',
+                                      '-m', 'pattern2'])
+        self.assertEqual(ns.match_tests, ['pattern1', 'pattern2'])
+
+        self.addCleanup(support.unlink, support.TESTFN)
+        with open(support.TESTFN, "w") as fp:
+            print('matchfile1', file=fp)
+            print('matchfile2', file=fp)
+
+        filename = os.path.abspath(support.TESTFN)
+        ns = libregrtest._parse_args(['-m', 'match',
+                                      '--matchfile', filename])
+        self.assertEqual(ns.match_tests,
+                         ['match', 'matchfile1', 'matchfile2'])
+
     def test_failfast(self):
         for opt in '-G', '--failfast':
             with self.subTest(opt=opt):
@@ -272,7 +290,6 @@ class ParseArgsTestCase(unittest.TestCase):
                 ns = libregrtest._parse_args([opt])
                 self.assertTrue(ns.forever)
 
-
     def test_unrecognized_argument(self):
         self.checkError(['--xxx'], 'usage:')
 
@@ -354,7 +371,7 @@ class BaseTestCase(unittest.TestCase):
         self.assertRegex(output, regex)
 
     def parse_executed_tests(self, output):
-        regex = (r'^[0-9]+:[0-9]+:[0-9]+ \[ *[0-9]+(?:/ *[0-9]+)?\] (%s)'
+        regex = (r'^[0-9]+:[0-9]+:[0-9]+ (?:load avg: [0-9]+\.[0-9]{2} )?\[ *[0-9]+(?:/ *[0-9]+)*\] (%s)'
                  % self.TESTNAME_REGEX)
         parser = re.finditer(regex, output, re.MULTILINE)
         return list(match.group(1) for match in parser)
@@ -454,7 +471,6 @@ class BaseTestCase(unittest.TestCase):
             self.fail(msg)
         return proc
 
-
     def run_python(self, args, **kw):
         args = [sys.executable, '-X', 'faulthandler', '-I', *args]
         proc = self.run_command(args, **kw)
@@ -676,6 +692,14 @@ class ArgsTestCase(BaseTestCase):
         output = self.run_tests('--fromfile', filename)
         self.check_executed_tests(output, tests)
 
+        # test format 'Lib/test/test_opcodes.py'
+        with open(filename, "w") as fp:
+            for name in tests:
+                print('Lib/test/%s.py' % name, file=fp)
+
+        output = self.run_tests('--fromfile', filename)
+        self.check_executed_tests(output, tests)
+
     def test_interrupted(self):
         code = TEST_INTERRUPTED
         test = self.create_test('sigint', code=code)
@@ -801,6 +825,79 @@ class ArgsTestCase(BaseTestCase):
         self.assertEqual(output.rstrip().splitlines(),
                          tests)
 
+    def test_list_cases(self):
+        # test --list-cases
+        code = textwrap.dedent("""
+            import unittest
+
+            class Tests(unittest.TestCase):
+                def test_method1(self):
+                    pass
+                def test_method2(self):
+                    pass
+        """)
+        testname = self.create_test(code=code)
+        all_methods = ['%s.Tests.test_method1' % testname,
+                       '%s.Tests.test_method2' % testname]
+        output = self.run_tests('--list-cases', testname)
+        self.assertEqual(output.splitlines(), all_methods)
+
+    def test_crashed(self):
+        # Any code which causes a crash
+        code = 'import faulthandler; faulthandler._sigsegv()'
+        crash_test = self.create_test(name="crash", code=code)
+        ok_test = self.create_test(name="ok")
+
+        tests = [crash_test, ok_test]
+        output = self.run_tests("-j2", *tests, exitcode=1)
+        self.check_executed_tests(output, tests, failed=crash_test,
+                                  randomize=True)
+
+    def parse_methods(self, output):
+        regex = re.compile("^(test[^ ]+).*ok$", flags=re.MULTILINE)
+        return [match.group(1) for match in regex.finditer(output)]
+
+    def test_matchfile(self):
+        code = textwrap.dedent("""
+            import unittest
+
+            class Tests(unittest.TestCase):
+                def test_method1(self):
+                    pass
+                def test_method2(self):
+                    pass
+                def test_method3(self):
+                    pass
+                def test_method4(self):
+                    pass
+        """)
+        all_methods = ['test_method1', 'test_method2',
+                       'test_method3', 'test_method4']
+        testname = self.create_test(code=code)
+
+        # by default, all methods should be run
+        output = self.run_tests("-v", testname)
+        methods = self.parse_methods(output)
+        self.assertEqual(methods, all_methods)
+
+        # only run a subset
+        filename = support.TESTFN
+        self.addCleanup(support.unlink, filename)
+
+        subset = [
+            # only match the method name
+            'test_method1',
+            # match the full identifier
+            '%s.Tests.test_method3' % testname]
+        with open(filename, "w") as fp:
+            for name in subset:
+                print(name, file=fp)
+
+        output = self.run_tests("-v", "--matchfile", filename, testname)
+        methods = self.parse_methods(output)
+        subset = ['test_method1', 'test_method3']
+        self.assertEqual(methods, subset)
+
 
 if __name__ == '__main__':
     unittest.main()