[libc++] Update availability markup for Filesystem on Apple platforms

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@365068 91177308-0d34-0410-b5e6-96231b3b80d8

include/__config

@@ -1294,15 +1294,15 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
      __attribute__((availability(macosx,strict,introduced=10.9)))              \
      __attribute__((availability(ios,strict,introduced=7.0)))
 #  define _LIBCPP_AVAILABILITY_FILESYSTEM                                      \
-     __attribute__((availability(macosx,strict,unavailable)))                  \
-     __attribute__((availability(ios,strict,unavailable)))                     \
-     __attribute__((availability(tvos,strict,unavailable)))                    \
-     __attribute__((availability(watchos,strict,unavailable)))
+     __attribute__((availability(macosx,strict,introduced=10.15)))             \
+     __attribute__((availability(ios,strict,introduced=13.0)))                 \
+     __attribute__((availability(tvos,strict,introduced=13.0)))                \
+     __attribute__((availability(watchos,strict,introduced=6.0)))
 #  define _LIBCPP_AVAILABILITY_FILESYSTEM_PUSH                                 \
-     _Pragma("clang attribute push(__attribute__((availability(macosx,strict,unavailable))), apply_to=any(function,record))") \
-     _Pragma("clang attribute push(__attribute__((availability(ios,strict,unavailable))), apply_to=any(function,record))")    \
-     _Pragma("clang attribute push(__attribute__((availability(tvos,strict,unavailable))), apply_to=any(function,record))")   \
-     _Pragma("clang attribute push(__attribute__((availability(watchos,strict,unavailable))), apply_to=any(function,record))")
+     _Pragma("clang attribute push(__attribute__((availability(macosx,strict,introduced=10.15))), apply_to=any(function,record))") \
+     _Pragma("clang attribute push(__attribute__((availability(ios,strict,introduced=13.0))), apply_to=any(function,record))")     \
+     _Pragma("clang attribute push(__attribute__((availability(tvos,strict,introduced=13.0))), apply_to=any(function,record))")    \
+     _Pragma("clang attribute push(__attribute__((availability(watchos,strict,introduced=6.0))), apply_to=any(function,record))")
 #  define _LIBCPP_AVAILABILITY_FILESYSTEM_POP                                  \
      _Pragma("clang attribute pop")                                            \
      _Pragma("clang attribute pop")                                            \

utils/libcxx/test/config.py

@@ -1164,10 +1164,10 @@ 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 not supported on Apple platforms yet
-            if name == 'macosx':
+            # Filesystem is support on Apple platforms starting with macosx10.15.
+            if name == 'macosx' and version in ('10.%s' % v for v in range(7, 15)):
                 self.config.available_features.add('dylib-has-no-filesystem')
-                self.lit_config.note("the deployment target does not support the dylib parts of <filesystem>")
+                self.lit_config.note("the deployment target does not support <filesystem>")
         else:
             self.cxx.flags += ['-D_LIBCPP_DISABLE_AVAILABILITY']