diff options
Diffstat (limited to 'libcxx/include/typeinfo')
| -rw-r--r-- | libcxx/include/typeinfo | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/libcxx/include/typeinfo b/libcxx/include/typeinfo index 7e76da538796..048e57614aff 100644 --- a/libcxx/include/typeinfo +++ b/libcxx/include/typeinfo @@ -57,6 +57,7 @@ public: */ #include <__config> +#include <__availability> #include <exception> #include <cstddef> #include <cstdint> @@ -141,7 +142,7 @@ public: // comparison is equal. // -------------------------------------------------------------------------- // // NonUniqueARMRTTIBit -// (selected on ARM64 regardless of _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION) +// (_LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION = 3) // -------------------------------------------------------------------------- // // This implementation of type_info does not assume always a unique copy of // the RTTI for a given type inside a program. It packs the pointer to the @@ -160,6 +161,24 @@ public: // the pointer when it constructs the type_info, depending on whether it can // guarantee uniqueness for that specific type_info. +// This value can be overriden in the __config_site. When it's not overriden, +// we pick a default implementation based on the platform here. +#ifndef _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION + + // Windows binaries can't merge typeinfos, so use the NonUnique implementation. +# ifdef _LIBCPP_OBJECT_FORMAT_COFF +# define _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION 2 + + // On arm64 on Apple platforms, use the special NonUniqueARMRTTIBit implementation. +# elif defined(__APPLE__) && defined(__LP64__) && !defined(__x86_64__) +# define _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION 3 + + // On all other platforms, assume the Itanium C++ ABI and use the Unique implementation. +# else +# define _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION 1 +# endif +#endif + struct __type_info_implementations { struct __string_impl_base { typedef const char* __type_name_t; @@ -243,7 +262,7 @@ struct __type_info_implementations { private: // The unique bit is the top bit. It is expected that __type_name_t is 64 bits when // this implementation is actually used. - typedef std::integral_constant<__type_name_t, + typedef integral_constant<__type_name_t, (1ULL << ((__CHAR_BIT__ * sizeof(__type_name_t)) - 1))> __non_unique_rtti_bit; _LIBCPP_INLINE_VISIBILITY @@ -257,12 +276,12 @@ struct __type_info_implementations { }; typedef -#if defined(__APPLE__) && defined(__LP64__) && !defined(__x86_64__) - __non_unique_arm_rtti_bit_impl -#elif _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION == 1 +#if _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION == 1 __unique_impl #elif _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION == 2 __non_unique_impl +#elif _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION == 3 + __non_unique_arm_rtti_bit_impl #else # error invalid configuration for _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION #endif |