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| author | Nikolas Klauser <nikolasklauser@berlin.de> | 2025-04-02 22:12:59 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-04-02 22:12:59 +0200 |
| commit | c59d3a268444b14c2db0fdea7e4bd929bb30630b (patch) | |
| tree | bd3ad7a4401a4dc0e73fb1028be228f6b1d814f9 | |
| parent | fb0e7b5f161118a24eeef39b05882f6950be43c0 (diff) | |
| download | llvm-c59d3a268444b14c2db0fdea7e4bd929bb30630b.zip llvm-c59d3a268444b14c2db0fdea7e4bd929bb30630b.tar.gz llvm-c59d3a268444b14c2db0fdea7e4bd929bb30630b.tar.bz2 | |
[libc++] Add visibility annotations to the std namespace with GCC (#133233)
This allows us to remove the need for `_LIBCPP_TEMPLATE_VIS` and fixes a
bunch of missing annotations for RTTI when used across dylib boundaries.
`_LIBCPP_TEMPLATE_VIS` itself will be removed in a separate patch, since
it touches a lot of code.
This patch is a no-op for Clang. Only GCC is affected.
| -rw-r--r-- | libcxx/docs/ReleaseNotes/21.rst | 5 | ||||
| -rw-r--r-- | libcxx/include/__config | 19 |
2 files changed, 13 insertions, 11 deletions
diff --git a/libcxx/docs/ReleaseNotes/21.rst b/libcxx/docs/ReleaseNotes/21.rst index 877aa06..7af109d 100644 --- a/libcxx/docs/ReleaseNotes/21.rst +++ b/libcxx/docs/ReleaseNotes/21.rst @@ -77,7 +77,10 @@ LLVM 22 ABI Affecting Changes --------------------- -- TODO +- When using GCC, the ``std`` namespace is now annotated with ``[[gnu::visibility("default")]]``. This may cause more + symbols to be exported from shared libraries when building with ``-fvisibility=hidden``. This also fixes RTTI + comparison between shared libraries, since all RTTI has the correct visibility now. There is no behaviour change on + Clang. Build System Changes diff --git a/libcxx/include/__config b/libcxx/include/__config index 35e62d0a..ce8bc38 100644 --- a/libcxx/include/__config +++ b/libcxx/include/__config @@ -386,7 +386,7 @@ typedef __char32_t char32_t; # define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS # define _LIBCPP_TEMPLATE_VIS # define _LIBCPP_TEMPLATE_DATA_VIS -# define _LIBCPP_TYPE_VISIBILITY_DEFAULT +# define _LIBCPP_NAMESPACE_VISIBILITY # else @@ -414,17 +414,16 @@ typedef __char32_t char32_t; # define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS # endif -// GCC doesn't support the type_visibility attribute, so we have to keep the visibility attribute on templates -# if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && !__has_attribute(__type_visibility__) -# define _LIBCPP_TEMPLATE_VIS __attribute__((__visibility__("default"))) -# else -# define _LIBCPP_TEMPLATE_VIS -# endif +// This is kept to avoid a huge library-wide diff in the first step. +// TODO: Remove this in a follow-up patch +# define _LIBCPP_TEMPLATE_VIS # if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__) -# define _LIBCPP_TYPE_VISIBILITY_DEFAULT __attribute__((__type_visibility__("default"))) +# define _LIBCPP_NAMESPACE_VISIBILITY __attribute__((__type_visibility__("default"))) +# elif !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) +# define _LIBCPP_NAMESPACE_VISIBILITY __attribute__((__visibility__("default"))) # else -# define _LIBCPP_TYPE_VISIBILITY_DEFAULT +# define _LIBCPP_NAMESPACE_VISIBILITY # endif # endif // defined(_LIBCPP_OBJECT_FORMAT_COFF) @@ -583,7 +582,7 @@ typedef __char32_t char32_t; // If it's not clear whether using the unversioned namespace is the correct thing to do, it's not. The versioned // namespace (_LIBCPP_BEGIN_NAMESPACE_STD) should almost always be used. # define _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD \ - _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std { + _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS namespace _LIBCPP_NAMESPACE_VISIBILITY std { # define _LIBCPP_END_UNVERSIONED_NAMESPACE_STD } _LIBCPP_POP_EXTENSION_DIAGNOSTICS |