[libc++] Remove the inline namespace for std::filesystem in ABIv2

[philnik777]

No description provided.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Nikolas Klauser (philnik777)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/92971.diff

1 Files Affected:

• (modified) libcxx/include/__config (+8)

diff --git a/libcxx/include/__config b/libcxx/include/__config
index 104a244cc82cc..b2f0a50cf787a 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -166,6 +166,8 @@
 // requires code not to make these assumptions.
 #    define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY
 #    define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_STRING_VIEW
+// Dont' add an inline namespace for `std::filesystem`
+#    define _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE
 #  elif _LIBCPP_ABI_VERSION == 1
 #    if !(defined(_LIBCPP_OBJECT_FORMAT_COFF) || defined(_LIBCPP_OBJECT_FORMAT_XCOFF))
 // Enable compiling copies of now inline methods into the dylib to support
@@ -831,10 +833,16 @@ typedef __char32_t char32_t;
                                inline namespace _LIBCPP_ABI_NAMESPACE {
 #  define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_POP_EXTENSION_DIAGNOSTICS
 
+#ifdef _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE
+#  define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD namespace filesystem {
+#  define _LIBCPP_END_NAMESPACE_FILESYSTEM } _LIBCPP_END_NAMESPACE_STD
+#else
 #  define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD                                               \
                                              inline namespace __fs { namespace filesystem {
 
 #  define _LIBCPP_END_NAMESPACE_FILESYSTEM }} _LIBCPP_END_NAMESPACE_STD
+#endif
+
 // clang-format on
 
 #  if __has_attribute(__enable_if__)

[EricWF]

Please try to add a brief explanation of why changes are made going forward.