[libc++] Translate the enable_filesystem parameter to the DSL

libcxx/utils/ci/macos-backdeployment.sh

@@ -119,10 +119,16 @@ fi
 LIBCXX_ROOT_ON_DEPLOYMENT_TARGET="${PREVIOUS_DYLIBS_DIR}/macOS/libc++/${DEPLOYMENT_TARGET}"
 LIBCXXABI_ROOT_ON_DEPLOYMENT_TARGET="${PREVIOUS_DYLIBS_DIR}/macOS/libc++abi/${DEPLOYMENT_TARGET}"
 
+# Filesystem is supported on Apple platforms starting with macosx10.15.
+if [[ ${DEPLOYMENT_TARGET} =~ "^10.9|10.10|10.11|10.12|10.13|10.14$" ]]; then
+    ENABLE_FILESYSTEM="--param enable_filesystem=False"
+fi
+
 # TODO: We need to also run the tests for libc++abi.
 echo "@@@ Running tests for libc++ @@@"
 "${LLVM_BUILD_DIR}/bin/llvm-lit" -sv "${MONOREPO_ROOT}/libcxx/test" \
                                  --param=enable_experimental=false \
+                                 ${ENABLE_FILESYSTEM} \
                                  --param=cxx_headers="${LLVM_INSTALL_DIR}/include/c++/v1" \
                                  --param=std="${STD}" \
                                  --param=platform="macosx${DEPLOYMENT_TARGET}" \

libcxx/utils/libcxx/test/config.py

@@ -328,9 +328,6 @@ class Configuration(object):
         if self.long_tests:
             self.config.available_features.add('long_tests')
 
-        if not self.get_lit_bool('enable_filesystem', default=True):
-            self.config.available_features.add('c++filesystem-disabled')
-
         if self.target_info.is_windows():
             self.config.available_features.add('windows')
             if self.cxx_stdlib_under_test == 'libc++':
@@ -868,10 +865,6 @@ class Configuration(object):
 
                 self.config.available_features.add('dylib-has-no-bad_any_cast')
                 self.lit_config.note("throwing bad_any_cast is not supported by the deployment target")
-            # Filesystem is support on Apple platforms starting with macosx10.15.
-            if name == 'macosx' and version in ('10.%s' % v for v in range(9, 15)):
-                self.config.available_features.add('c++filesystem-disabled')
-                self.lit_config.note("the deployment target does not support <filesystem>")
         else:
             self.cxx.compile_flags += ['-D_LIBCPP_DISABLE_AVAILABILITY']
 

libcxx/utils/libcxx/test/params.py

@@ -13,4 +13,10 @@ parameters = [
             help="Whether to enable exceptions when compiling the test suite.",
             feature=lambda exceptions: None if exceptions else
               Feature(name='no-exceptions', compileFlag='-fno-exceptions')),
+
+  # Parameters to enable or disable parts of the test suite
+  Parameter(name='enable_filesystem', choices=[True, False], type=bool, default=True,
+            help="Whether to enable tests for the C++ <filesystem> library.",
+            feature=lambda filesystem: None if filesystem else
+              Feature(name='c++filesystem-disabled')),
 ]