[libc++] Refactor test components into modules.

[danalbert]

Summary

I've moved the bulk of lit.cfg into test/libcxx/testconfig.py and
test/libcxx/testformat.py. All that remains in lit.cfg is the
logic to discover lit.site.cfg if lit.cfg was run directly, and the
logic for loading configuration variants.

The configuration variant flow has changed with this patch. Rather
than instantiating an object of type <VARIANT>Configuration, we now
instatiate an object of type Configuration that was loaded from the
module <VARIANT>.testconfig.py.

This has to be done on a per-project basis rather than in LIT itself
because LIT doesn't actually know where the real test directory is,
only where the site configuration is (which is usually in the output
directory). It's simple enough to do though, so it's fine to require
each project to do it themselves.

I also cleaned up all the pylint issues while I was here, which was
mostly just a matter of fixing long lines.

[EricWF]

Whooo! I'm super happy to see this patch! Lets do some bike-shedding!

I would like to see the test module go into a directory by itself. Should this directory live in libcxx/utils or libcxx/test?
What should we name the module? I like LibcxxTest.

Once testconfig.py and testformat.py live in a subdirectory can we drop the test prefix?

[danalbert]

In D6881#106444, @EricWF wrote:

I would like to see the test module go into a directory by itself. Should this directory live in libcxx/utils or libcxx/test?
What should we name the module? I like LibcxxTest.

Once testconfig.py and testformat.py live in a subdirectory can we drop the test prefix?

I had considered using libcxx.test.format/libcxx.test.config. I was sort of leaning toward that anyway. I'll make the change.

[danalbert]

Move libcxx.test* modules into libcxx.test.*.

[EricWF]

Just a nit, could we give the python module a more descriptive name than test? This change will make it possible to share libc++'s configuration and format with libc++abi. When using it in libc++abi the name test will be quite vague.

I'm also not sure I like the libcxx root being a python module. What is the benefit of that?

Also I would introduce a .gitignore into the top of libc++ so git users don't see the generated .pyc files.

[EricWF]

In D6881#106467, @EricWF wrote:

Just a nit, could we give the python module a more descriptive name than test? This change will make it possible to share libc++'s configuration and format with libc++abi. When using it in libc++abi the name test will be quite vague.

I'm also not sure I like the libcxx root being a python module. What is the benefit of that?

Woops, I misunderstood the layout of this patch. I would still like to see the configuration live somewhere else. The currently layout seems needlessly complicated. Also I think it could live in libcxx/test instead of libcxx/test/libcxx, leaving libcxx/test/libcxx to only contain tests.

Also, @jroelofs doesn't want any generated files. Could we use sys.dont_write_bytecode = True in lit.cfg to turn this off? This way SVN users won't have to worry about generated .pyc files either, and we keep the source directory clean.

[jroelofs]

Yeah... it would be really nice to be able to check out libcxx into a directory, then mark it all read-only, then build. *.pyc's get in the way of that (though I'm ok with using the '-B' python flag, or sys.dont_write_bytecode = True).

[danalbert]

In D6881#106471, @EricWF wrote:

Woops, I misunderstood the layout of this patch. I would still like to see the configuration live somewhere else. The currently layout seems needlessly complicated. Also I think it could live in libcxx/test instead of libcxx/test/libcxx, leaving libcxx/test/libcxx to only contain tests.

I had considered adding them directly to <libcxx-root>/test/ and having the sys.path be <libcxx-root>/.., but since the root isn't guaranteed to be named libcxx, you can't reliably import it. We can't set the sys.path to <libcxx-root>, because then they would be imported as import test.libcxxconfig (or whatever), and we need a more unique name for our top level package (there is already a test package). If we're willing to say that your top level directory must be named libcxx, then I'd be happy adding them directly to <libcxx-root>/test.

Also, @jroelofs doesn't want any generated files. Could we use sys.dont_write_bytecode = True in lit.cfg to turn this off? This way SVN users won't have to worry about generated .pyc files either, and we keep the source directory clean.

Ah, my mistake. I have .py[cod] in my global .gitignore, so I hadn't noticed it. I'll add the local .gitignore and be sure to set the svn props.

[danalbert]

Add a gitignore for Python things.

[EricWF]

Changes LGTM.

[danalbert]

Closed by r225532 (arc for some reason left out that detail).

.gitignore

+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+#lib/ # We actually have things checked in to lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.cache
+nosetests.xml
+coverage.xml
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/

test/libcxx/test/config.py

-# -*- Python -*- vim: set syntax=python tabstop=4 expandtab cc=80:
-
-# Configuration file for the 'lit' test runner.
-
-import errno
 import locale
 import os
 import platform
 import re
 import shlex
-import signal
-import subprocess
 import sys
-import tempfile
-import time
 
-import lit.Test
-import lit.formats
-import lit.util
-
-class LibcxxTestFormat(lit.formats.FileBasedTest):
-    """
-    Custom test format handler for use with the test format use by libc++.
-
-    Tests fall into two categories:
-      FOO.pass.cpp - Executable test which should compile, run, and exit with
-                     code 0.
-      FOO.fail.cpp - Negative test case which is expected to fail compilation.
-    """
-
-    def __init__(self, cxx_under_test, use_verify_for_fail,
-                 cpp_flags, ld_flags, exec_env,
-                 use_ccache=False):
-        self.cxx_under_test = cxx_under_test
-        self.use_verify_for_fail = use_verify_for_fail
-        self.cpp_flags = list(cpp_flags)
-        self.ld_flags = list(ld_flags)
-        self.exec_env = dict(exec_env)
-        self.use_ccache = use_ccache
-
-    def execute(self, test, lit_config):
-        while True:
-            try:
-                return self._execute(test, lit_config)
-            except OSError, oe:
-                if oe.errno != errno.ETXTBSY:
-                    raise
-                time.sleep(0.1)
-
-    def _execute(self, test, lit_config):
-        # Extract test metadata from the test file.
-        requires = []
-        unsupported = []
-        use_verify = False
-        with open(test.getSourcePath()) as f:
-            for ln in f:
-                if 'XFAIL:' in ln:
-                    items = ln[ln.index('XFAIL:') + 6:].split(',')
-                    test.xfails.extend([s.strip() for s in items])
-                elif 'REQUIRES:' in ln:
-                    items = ln[ln.index('REQUIRES:') + 9:].split(',')
-                    requires.extend([s.strip() for s in items])
-                elif 'UNSUPPORTED:' in ln:
-                    items = ln[ln.index('UNSUPPORTED:') + 12:].split(',')
-                    unsupported.extend([s.strip() for s in items])
-                elif 'USE_VERIFY' in ln and self.use_verify_for_fail:
-                    use_verify = True
-                elif not ln.strip().startswith("//") and ln.strip():
-                    # Stop at the first non-empty line that is not a C++
-                    # comment.
-                    break
-
-        # Check that we have the required features.
-        #
-        # FIXME: For now, this is cribbed from lit.TestRunner, to avoid
-        # introducing a dependency there. What we more ideally would like to do
-        # is lift the "requires" handling to be a core lit framework feature.
-        missing_required_features = [f for f in requires
-                                     if f not in test.config.available_features]
-        if missing_required_features:
-            return (lit.Test.UNSUPPORTED,
-                    "Test requires the following features: %s" % (
-                      ', '.join(missing_required_features),))
-
-        unsupported_features = [f for f in unsupported
-                             if f in test.config.available_features]
-        if unsupported_features:
-            return (lit.Test.UNSUPPORTED,
-                    "Test is unsupported with the following features: %s" % (
-                       ', '.join(unsupported_features),))
-
-        # Evaluate the test.
-        return self._evaluate_test(test, use_verify, lit_config)
-
-    def _make_report(self, cmd, out, err, rc):
-        report = "Command: %s\n" % cmd
-        report += "Exit Code: %d\n" % rc
-        if out:
-            report += "Standard Output:\n--\n%s--\n" % out
-        if err:
-            report += "Standard Error:\n--\n%s--\n" % err
-        report += '\n'
-        return cmd, report, rc
-
-    def _compile(self, output_path, source_path, use_verify=False):
-        cmd = [self.cxx_under_test, '-c', '-o', output_path, source_path]
-        cmd += self.cpp_flags
-        if use_verify:
-            cmd += ['-Xclang', '-verify']
-        if self.use_ccache:
-            cmd = ['ccache'] + cmd
-        out, err, rc = lit.util.executeCommand(cmd)
-        return cmd, out, err, rc
-
-    def _link(self, exec_path, object_path):
-        cmd = [self.cxx_under_test, '-o', exec_path, object_path]
-        cmd += self.cpp_flags + self.ld_flags
-        out, err, rc = lit.util.executeCommand(cmd)
-        return cmd, out, err, rc
-
-    def _compile_and_link(self, exec_path, source_path):
-        object_file = tempfile.NamedTemporaryFile(suffix=".o", delete=False)
-        object_path = object_file.name
-        object_file.close()
-        try:
-            cmd, out, err, rc = self._compile(object_path, source_path)
-            if rc != 0:
-                return cmd, out, err, rc
-            return self._link(exec_path, object_path)
-        finally:
-            try:
-                os.remove(object_path)
-            except:
-                pass
+import lit.Test  # pylint: disable=import-error,no-name-in-module
+import lit.util  # pylint: disable=import-error,no-name-in-module
 
-    def _build(self, exec_path, source_path, compile_only=False,
-               use_verify=False):
-        if compile_only:
-            cmd, out, err, rc = self._compile(exec_path, source_path, use_verify)
-        else:
-            assert not use_verify
-            cmd, out, err, rc = self._compile_and_link(exec_path, source_path)
-        return self._make_report(cmd, out, err, rc)
-
-    def _clean(self, exec_path):
-        os.remove(exec_path)
-
-    def _run(self, exec_path, lit_config, in_dir=None):
-        cmd = []
-        if self.exec_env:
-            cmd.append('env')
-            cmd.extend('%s=%s' % (name, value)
-                       for name,value in self.exec_env.items())
-        cmd.append(exec_path)
-        if lit_config.useValgrind:
-            cmd = lit_config.valgrindArgs + cmd
-        out, err, rc = lit.util.executeCommand(cmd, cwd=in_dir)
-        return self._make_report(cmd, out, err, rc)
-
-    def _evaluate_test(self, test, use_verify, lit_config):
-        name = test.path_in_suite[-1]
-        source_path = test.getSourcePath()
-        source_dir = os.path.dirname(source_path)
-
-        # Check what kind of test this is.
-        assert name.endswith('.pass.cpp') or name.endswith('.fail.cpp')
-        expected_compile_fail = name.endswith('.fail.cpp')
-
-        # If this is a compile (failure) test, build it and check for failure.
-        if expected_compile_fail:
-            cmd, report, rc = self._build('/dev/null', source_path,
-                                          compile_only=True,
-                                          use_verify=use_verify)
-            expected_rc = 0 if use_verify else 1
-            if rc == expected_rc:
-                return lit.Test.PASS, ""
-            else:
-                return lit.Test.FAIL, report + 'Expected compilation to fail!\n'
-        else:
-            exec_file = tempfile.NamedTemporaryFile(suffix="exe", delete=False)
-            exec_path = exec_file.name
-            exec_file.close()
-
-            try:
-                cmd, report, rc = self._build(exec_path, source_path)
-                compile_cmd = cmd
-                if rc != 0:
-                    report += "Compilation failed unexpectedly!"
-                    return lit.Test.FAIL, report
-
-                cmd, report, rc = self._run(exec_path, lit_config,
-                                            source_dir)
-                if rc != 0:
-                    report = "Compiled With: %s\n%s" % (compile_cmd, report)
-                    report += "Compiled test failed unexpectedly!"
-                    return lit.Test.FAIL, report
-            finally:
-                try:
-                    # Note that cleanup of exec_file happens in `_clean()`. If
-                    # you override this, cleanup is your reponsibility.
-                    self._clean(exec_path)
-                except:
-                    pass
-        return lit.Test.PASS, ""
+from libcxx.test.format import LibcxxTestFormat
 
 
 class Configuration(object):
+    # pylint: disable=redefined-outer-name
     def __init__(self, lit_config, config):
         self.lit_config = lit_config
         self.config = config
         self.cxx = None
         self.src_root = None
         self.obj_root = None
         self.library_root = None
         self.env = {}
         self.compile_flags = []
         self.link_flags = []
         self.use_system_lib = False
         self.use_clang_verify = False
         self.use_ccache = False
+        self.long_tests = None
 
         if platform.system() not in ('Darwin', 'FreeBSD', 'Linux'):
             self.lit_config.fatal("unrecognized system")
 
     def get_lit_conf(self, name, default=None):
         val = self.lit_config.params.get(name, None)
         if val is None:
             val = getattr(self.config, name, None)
def configure_cxx(self):
                     "inferred cxx_under_test as: %r" % self.cxx)
         if not self.cxx:
             self.lit_config.fatal('must specify user parameter cxx_under_test '
                                   '(e.g., --param=cxx_under_test=clang++)')
 
     def probe_cxx(self):
         # Dump all of the predefined macros
         dump_macro_cmd = [self.cxx, '-dM', '-E', '-x', 'c++', '/dev/null']
-        out, err, rc = lit.util.executeCommand(dump_macro_cmd)
+        out, _, rc = lit.util.executeCommand(dump_macro_cmd)
         if rc != 0:
             self.lit_config.warning('Failed to dump macros for compiler: %s' %
                                     self.cxx)
             return
         # Create a dict containing all the predefined macros.
         macros = {}
         lines = [l.strip() for l in out.split('\n') if l.strip()]
         for l in lines:
class Configuration(object):
     def configure_src_root(self):
         self.src_root = self.get_lit_conf(
             'libcxx_src_root', os.path.dirname(self.config.test_source_root))
 
     def configure_obj_root(self):
         self.obj_root = self.get_lit_conf('libcxx_obj_root', self.src_root)
 
     def configure_library_root(self):
-        self.library_root = self.get_lit_conf('libcxx_library_root', self.obj_root)
+        self.library_root = self.get_lit_conf('libcxx_library_root',
+                                              self.obj_root)
 
     def configure_use_system_lib(self):
         # This test suite supports testing against either the system library or
         # the locally built one; the former mode is useful for testing ABI
         # compatibility between the current headers and a shipping dynamic
         # library.
         self.use_system_lib = self.get_lit_bool('use_system_lib')
         if self.use_system_lib is None:
def configure_features(self):
                 'zh_CN.UTF-8': 'Chinese_China.936',
             },
         }
 
         default_locale = locale.setlocale(locale.LC_ALL)
         for feature, loc in locales[platform.system()].items():
             try:
                 locale.setlocale(locale.LC_ALL, loc)
-                self.config.available_features.add('locale.{0}'.format(feature))
-            except:
+                self.config.available_features.add(
+                    'locale.{0}'.format(feature))
+            except locale.Error:
                 self.lit_config.warning('The locale {0} is not supported by '
                                         'your platform. Some tests will be '
                                         'unsupported.'.format(loc))
         locale.setlocale(locale.LC_ALL, default_locale)
 
         # Write an "available feature" that combines the triple when
         # use_system_lib is enabled. This is so that we can easily write XFAIL
         # markers for tests that are known to fail with versions of libc++ as
def configure_compile_flags(self):
             self.config.available_features.add('rtti')
         else:
             self.compile_flags += ['-fno-rtti', '-D_LIBCPP_NO_RTTI']
         enable_32bit = self.get_lit_bool('enable_32bit', False)
         if enable_32bit:
             self.compile_flags += ['-m32']
         # Configure threading features.
         enable_threads = self.get_lit_bool('enable_threads', True)
-        enable_monotonic_clock = self.get_lit_bool('enable_monotonic_clock', True)
+        enable_monotonic_clock = self.get_lit_bool('enable_monotonic_clock',
+                                                   True)
         if not enable_threads:
             self.compile_flags += ['-D_LIBCPP_HAS_NO_THREADS']
             self.config.available_features.add('libcpp-has-no-threads')
             if not enable_monotonic_clock:
                 self.compile_flags += ['-D_LIBCPP_HAS_NO_MONOTONIC_CLOCK']
-                self.config.available_features.add('libcpp-has-no-monotonic-clock')
+                self.config.available_features.add(
+                    'libcpp-has-no-monotonic-clock')
         elif not enable_monotonic_clock:
             self.lit_config.fatal('enable_monotonic_clock cannot be false when'
                                   ' enable_threads is true.')
         # Use verbose output for better errors
         self.compile_flags += ['-v']
         # Configure extra compile flags.
         compile_flags_str = self.get_lit_conf('compile_flags', '')
         self.compile_flags += shlex.split(compile_flags_str)
 
-
     def configure_link_flags(self):
         self.link_flags += ['-nodefaultlibs']
         libcxx_library = self.get_lit_conf('libcxx_library')
         # Configure libc++ library paths.
         if libcxx_library is not None:
             # Check that the given value for libcxx_library is valid.
             if not os.path.isfile(libcxx_library):
                 self.lit_config.fatal(
-                    "libcxx_library='%s' is not a valid file." % libcxx_library)
+                    "libcxx_library='%s' is not a valid file." %
+                    libcxx_library)
             if self.use_system_lib:
-                self.lit_config.fatal("Conflicting options: 'libcxx_library'"
-                    " cannot be used with 'use_system_lib=true'")
-            self.link_flags += ['-Wl,-rpath,' + os.path.dirname(libcxx_library)]
+                self.lit_config.fatal(
+                    "Conflicting options: 'libcxx_library' cannot be used "
+                    "with 'use_system_lib=true'")
+            self.link_flags += ['-Wl,-rpath,' +
+                                os.path.dirname(libcxx_library)]
         elif not self.use_system_lib:
             self.link_flags += ['-L' + self.library_root,
                                 '-Wl,-rpath,' + self.library_root]
         # Configure ABI library paths.
         abi_library_path = self.get_lit_conf('abi_library_path', '')
         if abi_library_path:
             self.link_flags += ['-L' + abi_library_path,
                                 '-Wl,-rpath,' + abi_library_path]
def configure_link_flags(self):
         elif sys.platform.startswith('freebsd'):
             self.link_flags += ['-lc', '-lm', '-pthread', '-lgcc_s']
         else:
             self.lit_config.fatal("unrecognized system: %r" % sys.platform)
 
         link_flags_str = self.get_lit_conf('link_flags', '')
         self.link_flags += shlex.split(link_flags_str)
 
-
     def configure_sanitizer(self):
         san = self.get_lit_conf('use_sanitizer', '').strip()
         if san:
             # Search for llvm-symbolizer along the compiler path first
             # and then along the PATH env variable.
             symbolizer_search_paths = os.environ.get('PATH', '')
             cxx_path = lit.util.which(self.cxx)
             if cxx_path is not None:
-                symbolizer_search_paths = os.path.dirname(cxx_path) + \
-                                          os.pathsep + symbolizer_search_paths
+                symbolizer_search_paths = (
+                    os.path.dirname(cxx_path) +
+                    os.pathsep + symbolizer_search_paths)
             llvm_symbolizer = lit.util.which('llvm-symbolizer',
                                              symbolizer_search_paths)
             # Setup the sanitizer compile flags
             self.compile_flags += ['-g', '-fno-omit-frame-pointer']
             if sys.platform.startswith('linux'):
                 self.link_flags += ['-ldl']
             if san == 'Address':
                 self.compile_flags += ['-fsanitize=address']
class Configuration(object):
     def configure_env(self):
         if sys.platform == 'darwin' and not self.use_system_lib:
             libcxx_library = self.get_lit_conf('libcxx_library')
             if libcxx_library:
                 library_root = os.path.dirname(libcxx_library)
             else:
                 library_root = self.library_root
             self.env['DYLD_LIBRARY_PATH'] = library_root
-
-# name: The name of this test suite.
-config.name = 'libc++'
-
-# suffixes: A list of file extensions to treat as test files.
-config.suffixes = ['.cpp']
-
-# test_source_root: The root path where tests are located.
-config.test_source_root = os.path.dirname(__file__)
-
-# Infer the test_exec_root from the libcxx_object root.
-libcxx_obj_root = getattr(config, 'libcxx_obj_root', None)
-if libcxx_obj_root is not None:
-    config.test_exec_root = os.path.join(libcxx_obj_root, 'test')
-
-# Check that the test exec root is known.
-if config.test_exec_root is None:
-    # Otherwise, we haven't loaded the site specific configuration (the user is
-    # probably trying to run on a test file directly, and either the site
-    # configuration hasn't been created by the build system, or we are in an
-    # out-of-tree build situation).
-    site_cfg = lit_config.params.get('libcxx_site_config',
-                                     os.environ.get('LIBCXX_SITE_CONFIG'))
-    if not site_cfg:
-        lit_config.warning('No site specific configuration file found!'
-                           ' Running the tests in the default configuration.')
-        # TODO: Set test_exec_root to a temporary directory where output files
-        # can be placed. This is needed for ShTest.
-    elif not os.path.isfile(site_cfg):
-        lit_config.fatal(
-            "Specified site configuration file does not exist: '%s'"  %
-            site_cfg)
-    else:
-        lit_config.note('using site specific configuration at %s' % site_cfg)
-        lit_config.load_config(config, site_cfg)
-        raise SystemExit()
-
-
-cfg_variant = getattr(config, 'configuration_variant', '')
-if cfg_variant:
-    print 'Using configuration variant: %s' % cfg_variant
-
-# Construct an object of the type named `<VARIANT>Configuration`.
-configuration = globals()['%sConfiguration' % cfg_variant](lit_config, config)
-configuration.configure()
-config.test_format = configuration.get_test_format()

test/libcxx/test/format.py

+import errno
+import os
+import tempfile
+import time
+
+import lit.formats  # pylint: disable=import-error
+
+
+class LibcxxTestFormat(lit.formats.FileBasedTest):
+    """
+    Custom test format handler for use with the test format use by libc++.
+
+    Tests fall into two categories:
+      FOO.pass.cpp - Executable test which should compile, run, and exit with
+                     code 0.
+      FOO.fail.cpp - Negative test case which is expected to fail compilation.
+    """
+
+    def __init__(self, cxx_under_test, use_verify_for_fail,
+                 cpp_flags, ld_flags, exec_env,
+                 use_ccache=False):
+        self.cxx_under_test = cxx_under_test
+        self.use_verify_for_fail = use_verify_for_fail
+        self.cpp_flags = list(cpp_flags)
+        self.ld_flags = list(ld_flags)
+        self.exec_env = dict(exec_env)
+        self.use_ccache = use_ccache
+
+    def execute(self, test, lit_config):
+        while True:
+            try:
+                return self._execute(test, lit_config)
+            except OSError, oe:
+                if oe.errno != errno.ETXTBSY:
+                    raise
+                time.sleep(0.1)
+
+    def _execute(self, test, lit_config):
+        # Extract test metadata from the test file.
+        requires = []
+        unsupported = []
+        use_verify = False
+        with open(test.getSourcePath()) as f:
+            for ln in f:
+                if 'XFAIL:' in ln:
+                    items = ln[ln.index('XFAIL:') + 6:].split(',')
+                    test.xfails.extend([s.strip() for s in items])
+                elif 'REQUIRES:' in ln:
+                    items = ln[ln.index('REQUIRES:') + 9:].split(',')
+                    requires.extend([s.strip() for s in items])
+                elif 'UNSUPPORTED:' in ln:
+                    items = ln[ln.index('UNSUPPORTED:') + 12:].split(',')
+                    unsupported.extend([s.strip() for s in items])
+                elif 'USE_VERIFY' in ln and self.use_verify_for_fail:
+                    use_verify = True
+                elif not ln.strip().startswith("//") and ln.strip():
+                    # Stop at the first non-empty line that is not a C++
+                    # comment.
+                    break
+
+        # Check that we have the required features.
+        #
+        # FIXME: For now, this is cribbed from lit.TestRunner, to avoid
+        # introducing a dependency there. What we more ideally would like to do
+        # is lift the "requires" handling to be a core lit framework feature.
+        missing_required_features = [
+            f for f in requires
+            if f not in test.config.available_features
+        ]
+        if missing_required_features:
+            return (lit.Test.UNSUPPORTED,
+                    "Test requires the following features: %s" % (
+                        ', '.join(missing_required_features),))
+
+        unsupported_features = [f for f in unsupported
+                                if f in test.config.available_features]
+        if unsupported_features:
+            return (lit.Test.UNSUPPORTED,
+                    "Test is unsupported with the following features: %s" % (
+                        ', '.join(unsupported_features),))
+
+        # Evaluate the test.
+        return self._evaluate_test(test, use_verify, lit_config)
+
+    def _make_report(self, cmd, out, err, rc):  # pylint: disable=no-self-use
+        report = "Command: %s\n" % cmd
+        report += "Exit Code: %d\n" % rc
+        if out:
+            report += "Standard Output:\n--\n%s--\n" % out
+        if err:
+            report += "Standard Error:\n--\n%s--\n" % err
+        report += '\n'
+        return cmd, report, rc
+
+    def _compile(self, output_path, source_path, use_verify=False):
+        cmd = [self.cxx_under_test, '-c', '-o', output_path, source_path]
+        cmd += self.cpp_flags
+        if use_verify:
+            cmd += ['-Xclang', '-verify']
+        if self.use_ccache:
+            cmd = ['ccache'] + cmd
+        out, err, rc = lit.util.executeCommand(cmd)
+        return cmd, out, err, rc
+
+    def _link(self, exec_path, object_path):
+        cmd = [self.cxx_under_test, '-o', exec_path, object_path]
+        cmd += self.cpp_flags + self.ld_flags
+        out, err, rc = lit.util.executeCommand(cmd)
+        return cmd, out, err, rc
+
+    def _compile_and_link(self, exec_path, source_path):
+        object_file = tempfile.NamedTemporaryFile(suffix=".o", delete=False)
+        object_path = object_file.name
+        object_file.close()
+        try:
+            cmd, out, err, rc = self._compile(object_path, source_path)
+            if rc != 0:
+                return cmd, out, err, rc
+            return self._link(exec_path, object_path)
+        finally:
+            try:
+                os.remove(object_path)
+            except OSError:
+                pass
+
+    def _build(self, exec_path, source_path, compile_only=False,
+               use_verify=False):
+        if compile_only:
+            cmd, out, err, rc = self._compile(exec_path, source_path,
+                                              use_verify)
+        else:
+            assert not use_verify
+            cmd, out, err, rc = self._compile_and_link(exec_path, source_path)
+        return self._make_report(cmd, out, err, rc)
+
+    def _clean(self, exec_path):  # pylint: disable=no-self-use
+        try:
+            os.remove(exec_path)
+        except OSError:
+            pass
+
+    def _run(self, exec_path, lit_config, in_dir=None):
+        cmd = []
+        if self.exec_env:
+            cmd.append('env')
+            cmd.extend('%s=%s' % (name, value)
+                       for name, value in self.exec_env.items())
+        cmd.append(exec_path)
+        if lit_config.useValgrind:
+            cmd = lit_config.valgrindArgs + cmd
+        out, err, rc = lit.util.executeCommand(cmd, cwd=in_dir)
+        return self._make_report(cmd, out, err, rc)
+
+    def _evaluate_test(self, test, use_verify, lit_config):
+        name = test.path_in_suite[-1]
+        source_path = test.getSourcePath()
+        source_dir = os.path.dirname(source_path)
+
+        # Check what kind of test this is.
+        assert name.endswith('.pass.cpp') or name.endswith('.fail.cpp')
+        expected_compile_fail = name.endswith('.fail.cpp')
+
+        # If this is a compile (failure) test, build it and check for failure.
+        if expected_compile_fail:
+            cmd, report, rc = self._build('/dev/null', source_path,
+                                          compile_only=True,
+                                          use_verify=use_verify)
+            expected_rc = 0 if use_verify else 1
+            if rc == expected_rc:
+                return lit.Test.PASS, ""
+            else:
+                return (lit.Test.FAIL,
+                        report + 'Expected compilation to fail!\n')
+        else:
+            exec_file = tempfile.NamedTemporaryFile(suffix="exe", delete=False)
+            exec_path = exec_file.name
+            exec_file.close()
+
+            try:
+                cmd, report, rc = self._build(exec_path, source_path)
+                compile_cmd = cmd
+                if rc != 0:
+                    report += "Compilation failed unexpectedly!"
+                    return lit.Test.FAIL, report
+
+                cmd, report, rc = self._run(exec_path, lit_config,
+                                            source_dir)
+                if rc != 0:
+                    report = "Compiled With: %s\n%s" % (compile_cmd, report)
+                    report += "Compiled test failed unexpectedly!"
+                    return lit.Test.FAIL, report
+            finally:
+                # Note that cleanup of exec_file happens in `_clean()`. If you
+                # override this, cleanup is your reponsibility.
+                self._clean(exec_path)
+        return lit.Test.PASS, ""

test/lit.cfg

-# -*- Python -*- vim: set syntax=python tabstop=4 expandtab cc=80:
-
+# -*- Python -*- vim: set ft=python ts=4 sw=4 expandtab tw=79:
 # Configuration file for the 'lit' test runner.
-
-import errno
-import locale
 import os
-import platform
-import re
-import shlex
-import signal
-import subprocess
-import sys
-import tempfile
-import time
-
-import lit.Test
-import lit.formats
-import lit.util
-
-class LibcxxTestFormat(lit.formats.FileBasedTest):
-    """
-    Custom test format handler for use with the test format use by libc++.
-
-    Tests fall into two categories:
-      FOO.pass.cpp - Executable test which should compile, run, and exit with
-                     code 0.
-      FOO.fail.cpp - Negative test case which is expected to fail compilation.
-    """
-
-    def __init__(self, cxx_under_test, use_verify_for_fail,
-                 cpp_flags, ld_flags, exec_env,
-                 use_ccache=False):
-        self.cxx_under_test = cxx_under_test
-        self.use_verify_for_fail = use_verify_for_fail
-        self.cpp_flags = list(cpp_flags)
-        self.ld_flags = list(ld_flags)
-        self.exec_env = dict(exec_env)
-        self.use_ccache = use_ccache
-
-    def execute(self, test, lit_config):
-        while True:
-            try:
-                return self._execute(test, lit_config)
-            except OSError, oe:
-                if oe.errno != errno.ETXTBSY:
-                    raise
-                time.sleep(0.1)
-
-    def _execute(self, test, lit_config):
-        # Extract test metadata from the test file.
-        requires = []
-        unsupported = []
-        use_verify = False
-        with open(test.getSourcePath()) as f:
-            for ln in f:
-                if 'XFAIL:' in ln:
-                    items = ln[ln.index('XFAIL:') + 6:].split(',')
-                    test.xfails.extend([s.strip() for s in items])
-                elif 'REQUIRES:' in ln:
-                    items = ln[ln.index('REQUIRES:') + 9:].split(',')
-                    requires.extend([s.strip() for s in items])
-                elif 'UNSUPPORTED:' in ln:
-                    items = ln[ln.index('UNSUPPORTED:') + 12:].split(',')
-                    unsupported.extend([s.strip() for s in items])
-                elif 'USE_VERIFY' in ln and self.use_verify_for_fail:
-                    use_verify = True
-                elif not ln.strip().startswith("//") and ln.strip():
-                    # Stop at the first non-empty line that is not a C++
-                    # comment.
-                    break
-
-        # Check that we have the required features.
-        #
-        # FIXME: For now, this is cribbed from lit.TestRunner, to avoid
-        # introducing a dependency there. What we more ideally would like to do
-        # is lift the "requires" handling to be a core lit framework feature.
-        missing_required_features = [f for f in requires
-                                     if f not in test.config.available_features]
-        if missing_required_features:
-            return (lit.Test.UNSUPPORTED,
-                    "Test requires the following features: %s" % (
-                      ', '.join(missing_required_features),))
-
-        unsupported_features = [f for f in unsupported
-                             if f in test.config.available_features]
-        if unsupported_features:
-            return (lit.Test.UNSUPPORTED,
-                    "Test is unsupported with the following features: %s" % (
-                       ', '.join(unsupported_features),))
-
-        # Evaluate the test.
-        return self._evaluate_test(test, use_verify, lit_config)
-
-    def _make_report(self, cmd, out, err, rc):
-        report = "Command: %s\n" % cmd
-        report += "Exit Code: %d\n" % rc
-        if out:
-            report += "Standard Output:\n--\n%s--\n" % out
-        if err:
-            report += "Standard Error:\n--\n%s--\n" % err
-        report += '\n'
-        return cmd, report, rc
-
-    def _compile(self, output_path, source_path, use_verify=False):
-        cmd = [self.cxx_under_test, '-c', '-o', output_path, source_path]
-        cmd += self.cpp_flags
-        if use_verify:
-            cmd += ['-Xclang', '-verify']
-        if self.use_ccache:
-            cmd = ['ccache'] + cmd
-        out, err, rc = lit.util.executeCommand(cmd)
-        return cmd, out, err, rc
-
-    def _link(self, exec_path, object_path):
-        cmd = [self.cxx_under_test, '-o', exec_path, object_path]
-        cmd += self.cpp_flags + self.ld_flags
-        out, err, rc = lit.util.executeCommand(cmd)
-        return cmd, out, err, rc
-
-    def _compile_and_link(self, exec_path, source_path):
-        object_file = tempfile.NamedTemporaryFile(suffix=".o", delete=False)
-        object_path = object_file.name
-        object_file.close()
-        try:
-            cmd, out, err, rc = self._compile(object_path, source_path)
-            if rc != 0:
-                return cmd, out, err, rc
-            return self._link(exec_path, object_path)
-        finally:
-            try:
-                os.remove(object_path)
-            except:
-                pass
-
-    def _build(self, exec_path, source_path, compile_only=False,
-               use_verify=False):
-        if compile_only:
-            cmd, out, err, rc = self._compile(exec_path, source_path, use_verify)
-        else:
-            assert not use_verify
-            cmd, out, err, rc = self._compile_and_link(exec_path, source_path)
-        return self._make_report(cmd, out, err, rc)
-
-    def _clean(self, exec_path):
-        os.remove(exec_path)
-
-    def _run(self, exec_path, lit_config, in_dir=None):
-        cmd = []
-        if self.exec_env:
-            cmd.append('env')
-            cmd.extend('%s=%s' % (name, value)
-                       for name,value in self.exec_env.items())
-        cmd.append(exec_path)
-        if lit_config.useValgrind:
-            cmd = lit_config.valgrindArgs + cmd
-        out, err, rc = lit.util.executeCommand(cmd, cwd=in_dir)
-        return self._make_report(cmd, out, err, rc)
-
-    def _evaluate_test(self, test, use_verify, lit_config):
-        name = test.path_in_suite[-1]
-        source_path = test.getSourcePath()
-        source_dir = os.path.dirname(source_path)
-
-        # Check what kind of test this is.
-        assert name.endswith('.pass.cpp') or name.endswith('.fail.cpp')
-        expected_compile_fail = name.endswith('.fail.cpp')
-
-        # If this is a compile (failure) test, build it and check for failure.
-        if expected_compile_fail:
-            cmd, report, rc = self._build('/dev/null', source_path,
-                                          compile_only=True,
-                                          use_verify=use_verify)
-            expected_rc = 0 if use_verify else 1
-            if rc == expected_rc:
-                return lit.Test.PASS, ""
-            else:
-                return lit.Test.FAIL, report + 'Expected compilation to fail!\n'
-        else:
-            exec_file = tempfile.NamedTemporaryFile(suffix="exe", delete=False)
-            exec_path = exec_file.name
-            exec_file.close()
-
-            try:
-                cmd, report, rc = self._build(exec_path, source_path)
-                compile_cmd = cmd
-                if rc != 0:
-                    report += "Compilation failed unexpectedly!"
-                    return lit.Test.FAIL, report
-
-                cmd, report, rc = self._run(exec_path, lit_config,
-                                            source_dir)
-                if rc != 0:
-                    report = "Compiled With: %s\n%s" % (compile_cmd, report)
-                    report += "Compiled test failed unexpectedly!"
-                    return lit.Test.FAIL, report
-            finally:
-                try:
-                    # Note that cleanup of exec_file happens in `_clean()`. If
-                    # you override this, cleanup is your reponsibility.
-                    self._clean(exec_path)
-                except:
-                    pass
-        return lit.Test.PASS, ""
-
-
-class Configuration(object):
-    def __init__(self, lit_config, config):
-        self.lit_config = lit_config
-        self.config = config
-        self.cxx = None
-        self.src_root = None
-        self.obj_root = None
-        self.library_root = None
-        self.env = {}
-        self.compile_flags = []
-        self.link_flags = []
-        self.use_system_lib = False
-        self.use_clang_verify = False
-        self.use_ccache = False
-
-        if platform.system() not in ('Darwin', 'FreeBSD', 'Linux'):
-            self.lit_config.fatal("unrecognized system")
-
-    def get_lit_conf(self, name, default=None):
-        val = self.lit_config.params.get(name, None)
-        if val is None:
-            val = getattr(self.config, name, None)
-            if val is None:
-                val = default
-        return val
-
-    def get_lit_bool(self, name, default=None):
-        conf = self.get_lit_conf(name)
-        if conf is None:
-            return default
-        if conf.lower() in ('1', 'true'):
-            return True
-        if conf.lower() in ('', '0', 'false'):
-            return False
-        self.lit_config.fatal(
-            "parameter '{}' should be true or false".format(name))
-
-    def configure(self):
-        self.configure_cxx()
-        self.probe_cxx()
-        self.configure_triple()
-        self.configure_src_root()
-        self.configure_obj_root()
-        self.configure_library_root()
-        self.configure_use_system_lib()
-        self.configure_use_clang_verify()
-        self.configure_ccache()
-        self.configure_env()
-        self.configure_compile_flags()
-        self.configure_link_flags()
-        self.configure_sanitizer()
-        self.configure_features()
-        # Print the final compile and link flags.
-        self.lit_config.note('Using compile flags: %s' % self.compile_flags)
-        self.lit_config.note('Using link flags: %s' % self.link_flags)
-        # Print as list to prevent "set([...])" from being printed.
-        self.lit_config.note('Using available_features: %s' %
-                             list(self.config.available_features))
-
-    def get_test_format(self):
-        return LibcxxTestFormat(
-            self.cxx,
-            self.use_clang_verify,
-            cpp_flags=self.compile_flags,
-            ld_flags=self.link_flags,
-            exec_env=self.env,
-            use_ccache=self.use_ccache)
-
-    def configure_cxx(self):
-        # Gather various compiler parameters.
-        self.cxx = self.get_lit_conf('cxx_under_test')
-
-        # If no specific cxx_under_test was given, attempt to infer it as
-        # clang++.
-        if self.cxx is None:
-            clangxx = lit.util.which('clang++',
-                                     self.config.environment['PATH'])
-            if clangxx:
-                self.cxx = clangxx
-                self.lit_config.note(
-                    "inferred cxx_under_test as: %r" % self.cxx)
-        if not self.cxx:
-            self.lit_config.fatal('must specify user parameter cxx_under_test '
-                                  '(e.g., --param=cxx_under_test=clang++)')
-
-    def probe_cxx(self):
-        # Dump all of the predefined macros
-        dump_macro_cmd = [self.cxx, '-dM', '-E', '-x', 'c++', '/dev/null']
-        out, err, rc = lit.util.executeCommand(dump_macro_cmd)
-        if rc != 0:
-            self.lit_config.warning('Failed to dump macros for compiler: %s' %
-                                    self.cxx)
-            return
-        # Create a dict containing all the predefined macros.
-        macros = {}
-        lines = [l.strip() for l in out.split('\n') if l.strip()]
-        for l in lines:
-            assert l.startswith('#define ')
-            l = l[len('#define '):]
-            macro, _, value = l.partition(' ')
-            macros[macro] = value
-        # Add compiler information to available features.
-        compiler_name = None
-        major_ver = minor_ver = None
-        if '__clang__' in macros.keys():
-            compiler_name = 'clang'
-            # Treat apple's llvm fork differently.
-            if '__apple_build_version__' in macros.keys():
-                compiler_name = 'apple-clang'
-            major_ver = macros['__clang_major__']
-            minor_ver = macros['__clang_minor__']
-        elif '__GNUC__' in macros.keys():
-            compiler_name = 'gcc'
-            major_ver = macros['__GNUC__']
-            minor_ver = macros['__GNUC_MINOR__']
-        else:
-            self.lit_config.warning('Failed to detect compiler for cxx: %s' %
-                                    self.cxx)
-        if compiler_name is not None:
-            self.config.available_features.add(compiler_name)
-            self.config.available_features.add('%s-%s.%s' % (
-                compiler_name, major_ver, minor_ver))
-
-    def configure_src_root(self):
-        self.src_root = self.get_lit_conf(
-            'libcxx_src_root', os.path.dirname(self.config.test_source_root))
-
-    def configure_obj_root(self):
-        self.obj_root = self.get_lit_conf('libcxx_obj_root', self.src_root)
-
-    def configure_library_root(self):
-        self.library_root = self.get_lit_conf('libcxx_library_root', self.obj_root)
-
-    def configure_use_system_lib(self):
-        # This test suite supports testing against either the system library or
-        # the locally built one; the former mode is useful for testing ABI
-        # compatibility between the current headers and a shipping dynamic
-        # library.
-        self.use_system_lib = self.get_lit_bool('use_system_lib')
-        if self.use_system_lib is None:
-            # Default to testing against the locally built libc++ library.
-            self.use_system_lib = False
-            self.lit_config.note(
-                "inferred use_system_lib as: %r" % self.use_system_lib)
-
-    def configure_use_clang_verify(self):
-        '''If set, run clang with -verify on failing tests.'''
-        self.use_clang_verify = self.get_lit_bool('use_clang_verify')
-        if self.use_clang_verify is None:
-            # TODO: Default this to True when using clang.
-            self.use_clang_verify = False
-            self.lit_config.note(
-                "inferred use_clang_verify as: %r" % self.use_clang_verify)
-
-    def configure_ccache(self):
-        self.use_ccache = self.get_lit_bool('use_ccache', False)
-        if self.use_ccache:
-            self.lit_config.note('enabling ccache')
-
-    def configure_features(self):
-        additional_features = self.get_lit_conf('additional_features')
-        if additional_features:
-            for f in additional_features.split(','):
-                self.config.available_features.add(f.strip())
-
-        # Figure out which of the required locales we support
-        locales = {
-            'Darwin': {
-                'en_US.UTF-8': 'en_US.UTF-8',
-                'cs_CZ.ISO8859-2': 'cs_CZ.ISO8859-2',
-                'fr_FR.UTF-8': 'fr_FR.UTF-8',
-                'fr_CA.ISO8859-1': 'cs_CZ.ISO8859-1',
-                'ru_RU.UTF-8': 'ru_RU.UTF-8',
-                'zh_CN.UTF-8': 'zh_CN.UTF-8',
-            },
-            'FreeBSD': {
-                'en_US.UTF-8': 'en_US.UTF-8',
-                'cs_CZ.ISO8859-2': 'cs_CZ.ISO8859-2',
-                'fr_FR.UTF-8': 'fr_FR.UTF-8',
-                'fr_CA.ISO8859-1': 'fr_CA.ISO8859-1',
-                'ru_RU.UTF-8': 'ru_RU.UTF-8',
-                'zh_CN.UTF-8': 'zh_CN.UTF-8',
-            },
-            'Linux': {
-                'en_US.UTF-8': 'en_US.UTF-8',
-                'cs_CZ.ISO8859-2': 'cs_CZ.ISO-8859-2',
-                'fr_FR.UTF-8': 'fr_FR.UTF-8',
-                'fr_CA.ISO8859-1': 'fr_CA.ISO-8859-1',
-                'ru_RU.UTF-8': 'ru_RU.UTF-8',
-                'zh_CN.UTF-8': 'zh_CN.UTF-8',
-            },
-            'Windows': {
-                'en_US.UTF-8': 'English_United States.1252',
-                'cs_CZ.ISO8859-2': 'Czech_Czech Republic.1250',
-                'fr_FR.UTF-8': 'French_France.1252',
-                'fr_CA.ISO8859-1': 'French_Canada.1252',
-                'ru_RU.UTF-8': 'Russian_Russia.1251',
-                'zh_CN.UTF-8': 'Chinese_China.936',
-            },
-        }
-
-        default_locale = locale.setlocale(locale.LC_ALL)
-        for feature, loc in locales[platform.system()].items():
-            try:
-                locale.setlocale(locale.LC_ALL, loc)
-                self.config.available_features.add('locale.{0}'.format(feature))
-            except:
-                self.lit_config.warning('The locale {0} is not supported by '
-                                        'your platform. Some tests will be '
-                                        'unsupported.'.format(loc))
-        locale.setlocale(locale.LC_ALL, default_locale)
-
-        # Write an "available feature" that combines the triple when
-        # use_system_lib is enabled. This is so that we can easily write XFAIL
-        # markers for tests that are known to fail with versions of libc++ as
-        # were shipped with a particular triple.
-        if self.use_system_lib:
-            self.config.available_features.add(
-                'with_system_lib=%s' % self.config.target_triple)
-
-        # Some linux distributions have different locale data than others.
-        # Insert the distributions name and name-version into the available
-        # features to allow tests to XFAIL on them.
-        if sys.platform.startswith('linux'):
-            name, ver, _ = platform.linux_distribution()
-            name = name.lower().strip()
-            ver = ver.lower().strip()
-            if name:
-                self.config.available_features.add(name)
-            if name and ver:
-                self.config.available_features.add('%s-%s' % (name, ver))
-
-        # Simulator testing can take a really long time for some of these tests
-        # so add a feature check so we can REQUIRES: long_tests in them
-        self.long_tests = self.get_lit_bool('long_tests')
-        if self.long_tests is None:
-            # Default to running long tests.
-            self.long_tests = True
-            self.lit_config.note(
-                "inferred long_tests as: %r" % self.long_tests)
-
-        if self.long_tests:
-            self.config.available_features.add('long_tests')
-
-    def configure_compile_flags(self):
-        # Try and get the std version from the command line. Fall back to
-        # default given in lit.site.cfg is not present. If default is not
-        # present then force c++11.
-        std = self.get_lit_conf('std', 'c++11')
-        self.compile_flags += ['-std={0}'.format(std)]
-        self.config.available_features.add(std)
-        # Configure include paths
-        self.compile_flags += ['-nostdinc++']
-        self.compile_flags += ['-I' + self.src_root + '/test/support']
-        libcxx_headers = self.get_lit_conf('libcxx_headers',
-                                           self.src_root + '/include')
-        if not os.path.isdir(libcxx_headers):
-            self.lit_config.fatal("libcxx_headers='%s' is not a directory."
-                                  % libcxx_headers)
-        self.compile_flags += ['-I' + libcxx_headers]
-        if sys.platform.startswith('linux'):
-            self.compile_flags += ['-D__STDC_FORMAT_MACROS',
-                                   '-D__STDC_LIMIT_MACROS',
-                                   '-D__STDC_CONSTANT_MACROS']
-        # Configure feature flags.
-        enable_exceptions = self.get_lit_bool('enable_exceptions', True)
-        if enable_exceptions:
-            self.config.available_features.add('exceptions')
-        else:
-            self.compile_flags += ['-fno-exceptions']
-        enable_rtti = self.get_lit_bool('enable_rtti', True)
-        if enable_rtti:
-            self.config.available_features.add('rtti')
-        else:
-            self.compile_flags += ['-fno-rtti', '-D_LIBCPP_NO_RTTI']
-        enable_32bit = self.get_lit_bool('enable_32bit', False)
-        if enable_32bit:
-            self.compile_flags += ['-m32']
-        # Configure threading features.
-        enable_threads = self.get_lit_bool('enable_threads', True)
-        enable_monotonic_clock = self.get_lit_bool('enable_monotonic_clock', True)
-        if not enable_threads:
-            self.compile_flags += ['-D_LIBCPP_HAS_NO_THREADS']
-            self.config.available_features.add('libcpp-has-no-threads')
-            if not enable_monotonic_clock:
-                self.compile_flags += ['-D_LIBCPP_HAS_NO_MONOTONIC_CLOCK']
-                self.config.available_features.add('libcpp-has-no-monotonic-clock')
-        elif not enable_monotonic_clock:
-            self.lit_config.fatal('enable_monotonic_clock cannot be false when'
-                                  ' enable_threads is true.')
-        # Use verbose output for better errors
-        self.compile_flags += ['-v']
-        # Configure extra compile flags.
-        compile_flags_str = self.get_lit_conf('compile_flags', '')
-        self.compile_flags += shlex.split(compile_flags_str)
-
-
-    def configure_link_flags(self):
-        self.link_flags += ['-nodefaultlibs']
-        libcxx_library = self.get_lit_conf('libcxx_library')
-        # Configure libc++ library paths.
-        if libcxx_library is not None:
-            # Check that the given value for libcxx_library is valid.
-            if not os.path.isfile(libcxx_library):
-                self.lit_config.fatal(
-                    "libcxx_library='%s' is not a valid file." % libcxx_library)
-            if self.use_system_lib:
-                self.lit_config.fatal("Conflicting options: 'libcxx_library'"
-                    " cannot be used with 'use_system_lib=true'")
-            self.link_flags += ['-Wl,-rpath,' + os.path.dirname(libcxx_library)]
-        elif not self.use_system_lib:
-            self.link_flags += ['-L' + self.library_root,
-                                '-Wl,-rpath,' + self.library_root]
-        # Configure ABI library paths.
-        abi_library_path = self.get_lit_conf('abi_library_path', '')
-        if abi_library_path:
-            self.link_flags += ['-L' + abi_library_path,
-                                '-Wl,-rpath,' + abi_library_path]
-        # Configure libraries
-        if libcxx_library:
-            self.link_flags += [libcxx_library]
-        else:
-            self.link_flags += ['-lc++']
-        cxx_abi = self.get_lit_conf('cxx_abi', 'libcxxabi')
-        if cxx_abi == 'libstdc++':
-            self.link_flags += ['-lstdc++']
-        elif cxx_abi == 'libsupc++':
-            self.link_flags += ['-lsupc++']
-        elif cxx_abi == 'libcxxabi':
-            self.link_flags += ['-lc++abi']
-        elif cxx_abi == 'libcxxrt':
-            self.link_flags += ['-lcxxrt']
-        elif cxx_abi == 'none':
-            pass
-        else:
-            self.lit_config.fatal(
-                'C++ ABI setting %s unsupported for tests' % cxx_abi)
-        # Configure extra libraries.
-        if sys.platform == 'darwin':
-            self.link_flags += ['-lSystem']
-        elif sys.platform.startswith('linux'):
-            self.link_flags += ['-lgcc_eh', '-lc', '-lm', '-lpthread',
-                                '-lrt', '-lgcc_s']
-        elif sys.platform.startswith('freebsd'):
-            self.link_flags += ['-lc', '-lm', '-pthread', '-lgcc_s']
-        else:
-            self.lit_config.fatal("unrecognized system: %r" % sys.platform)
-
-        link_flags_str = self.get_lit_conf('link_flags', '')
-        self.link_flags += shlex.split(link_flags_str)
+import site
 
+site.addsitedir(os.path.dirname(__file__))
 
-    def configure_sanitizer(self):
-        san = self.get_lit_conf('use_sanitizer', '').strip()
-        if san:
-            # Search for llvm-symbolizer along the compiler path first
-            # and then along the PATH env variable.
-            symbolizer_search_paths = os.environ.get('PATH', '')
-            cxx_path = lit.util.which(self.cxx)
-            if cxx_path is not None:
-                symbolizer_search_paths = os.path.dirname(cxx_path) + \
-                                          os.pathsep + symbolizer_search_paths
-            llvm_symbolizer = lit.util.which('llvm-symbolizer',
-                                             symbolizer_search_paths)
-            # Setup the sanitizer compile flags
-            self.compile_flags += ['-g', '-fno-omit-frame-pointer']
-            if sys.platform.startswith('linux'):
-                self.link_flags += ['-ldl']
-            if san == 'Address':
-                self.compile_flags += ['-fsanitize=address']
-                if llvm_symbolizer is not None:
-                    self.env['ASAN_SYMBOLIZER_PATH'] = llvm_symbolizer
-                self.config.available_features.add('asan')
-            elif san == 'Memory' or san == 'MemoryWithOrigins':
-                self.compile_flags += ['-fsanitize=memory']
-                if san == 'MemoryWithOrigins':
-                    self.compile_flags += ['-fsanitize-memory-track-origins']
-                if llvm_symbolizer is not None:
-                    self.env['MSAN_SYMBOLIZER_PATH'] = llvm_symbolizer
-                self.config.available_features.add('msan')
-            elif san == 'Undefined':
-                self.compile_flags += ['-fsanitize=undefined',
-                                       '-fno-sanitize=vptr,function',
-                                       '-fno-sanitize-recover', '-O3']
-                self.config.available_features.add('ubsan')
-            elif san == 'Thread':
-                self.compile_flags += ['-fsanitize=thread']
-                self.config.available_features.add('tsan')
-            else:
-                self.lit_config.fatal('unsupported value for '
-                                      'libcxx_use_san: {0}'.format(san))
 
-    def configure_triple(self):
-        # Get or infer the target triple.
-        self.config.target_triple = self.get_lit_conf('target_triple')
-        # If no target triple was given, try to infer it from the compiler
-        # under test.
-        if not self.config.target_triple:
-            target_triple = lit.util.capture(
-                [self.cxx, '-dumpmachine']).strip()
-            # Drop sub-major version components from the triple, because the
-            # current XFAIL handling expects exact matches for feature checks.
-            # Example: x86_64-apple-darwin14.0.0 -> x86_64-apple-darwin14
-            # The 5th group handles triples greater than 3 parts
-            # (ex x86_64-pc-linux-gnu).
-            target_triple = re.sub(r'([^-]+)-([^-]+)-([^.]+)([^-]*)(.*)',
-                                   r'\1-\2-\3\5', target_triple)
-            # linux-gnu is needed in the triple to properly identify linuxes
-            # that use GLIBC. Handle redhat and opensuse triples as special
-            # cases and append the missing `-gnu` portion.
-            if target_triple.endswith('redhat-linux') or \
-               target_triple.endswith('suse-linux'):
-                target_triple += '-gnu'
-            self.config.target_triple = target_triple
-            self.lit_config.note(
-                "inferred target_triple as: %r" % self.config.target_triple)
-
-    def configure_env(self):
-        if sys.platform == 'darwin' and not self.use_system_lib:
-            libcxx_library = self.get_lit_conf('libcxx_library')
-            if libcxx_library:
-                library_root = os.path.dirname(libcxx_library)
-            else:
-                library_root = self.library_root
-            self.env['DYLD_LIBRARY_PATH'] = library_root
+# Tell pylint that we know config and lit_config exist somewhere.
+if 'PYLINT_IMPORT' in os.environ:
+    config = object()
+    lit_config = object()
 
 # name: The name of this test suite.
 config.name = 'libc++'
 
 # suffixes: A list of file extensions to treat as test files.
 config.suffixes = ['.cpp']
 
 # test_source_root: The root path where tests are located.
site_cfg = lit_config.params.get('libcxx_site_config',
                                      os.environ.get('LIBCXX_SITE_CONFIG'))
     if not site_cfg:
         lit_config.warning('No site specific configuration file found!'
                            ' Running the tests in the default configuration.')
         # TODO: Set test_exec_root to a temporary directory where output files
         # can be placed. This is needed for ShTest.
     elif not os.path.isfile(site_cfg):
         lit_config.fatal(
-            "Specified site configuration file does not exist: '%s'"  %
+            "Specified site configuration file does not exist: '%s'" %
             site_cfg)
     else:
         lit_config.note('using site specific configuration at %s' % site_cfg)
         lit_config.load_config(config, site_cfg)
         raise SystemExit()
 
-
-cfg_variant = getattr(config, 'configuration_variant', '')
+cfg_variant = getattr(config, 'configuration_variant', 'libcxx')
 if cfg_variant:
     print 'Using configuration variant: %s' % cfg_variant
 
-# Construct an object of the type named `<VARIANT>Configuration`.
-configuration = globals()['%sConfiguration' % cfg_variant](lit_config, config)
+# Load the Configuration class from the module name <cfg_variant>.test.config.
+config_module_name = '.'.join([cfg_variant, 'test', 'config'])
+config_module = __import__(config_module_name, fromlist=['Configuration'])
+
+configuration = config_module.Configuration(lit_config, config)
 configuration.configure()
 config.test_format = configuration.get_test_format()