diff options
| -rw-r--r-- | libcxx/docs/ReleaseNotes.rst | 7 | ||||
| -rw-r--r-- | libcxx/include/__config | 11 |
2 files changed, 17 insertions, 1 deletions
diff --git a/libcxx/docs/ReleaseNotes.rst b/libcxx/docs/ReleaseNotes.rst index 52d7a1ed42f..4cf5182a7f3 100644 --- a/libcxx/docs/ReleaseNotes.rst +++ b/libcxx/docs/ReleaseNotes.rst @@ -41,3 +41,10 @@ New Features API Changes ----------- - Building libc++ for Mac OSX 10.6 is not supported anymore. +- Starting with LLVM 8.0.0, users that wish to link together translation units + built with different versions of libc++'s headers into the same final linked + image MUST define the _LIBCPP_HIDE_FROM_ABI_PER_TU macro to 1 when building + those translation units. Not defining _LIBCPP_HIDE_FROM_ABI_PER_TU to 1 and + linking translation units built with different versions of libc++'s headers + together may lead to ODR violations and ABI issues. On the flipside, code + size improvements should be expected for everyone not defining the macro. diff --git a/libcxx/include/__config b/libcxx/include/__config index f6020748e1b..6f133b678a0 100644 --- a/libcxx/include/__config +++ b/libcxx/include/__config @@ -787,6 +787,15 @@ _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD # define _LIBCPP_INTERNAL_LINKAGE _LIBCPP_ALWAYS_INLINE #endif +#if __has_attribute(exclude_from_explicit_instantiation) +# define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__ ((__exclude_from_explicit_instantiation__)) +#else + // Try to approximate the effect of exclude_from_explicit_instantiation + // (which is that entities are not assumed to be provided by explicit + // template instantitations in the dylib) by always inlining those entities. +# define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE +#endif + #ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU # ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT # define _LIBCPP_HIDE_FROM_ABI_PER_TU 0 @@ -799,7 +808,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD # if _LIBCPP_HIDE_FROM_ABI_PER_TU # define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE # else -# define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_ALWAYS_INLINE +# define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION # endif #endif |
