libcxx/src/typeinfo.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include <typeinfo>
  10
  11 #if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_ABI_VCRUNTIME)
  12
  13 #include <string.h>
  14
  15 int std::type_info::__compare(const type_info &__rhs) const noexcept {
  16   if (&__data == &__rhs.__data)
  17     return 0;
  18   return strcmp(&__data.__decorated_name[1], &__rhs.__data.__decorated_name[1]);
  19 }
  20
  21 const char *std::type_info::name() const noexcept {
  22   // TODO(compnerd) cache demangled &__data.__decorated_name[1]
  23   return &__data.__decorated_name[1];
  24 }
  25
  26 size_t std::type_info::hash_code() const noexcept {
  27 #if defined(_WIN64)
  28   constexpr size_t fnv_offset_basis = 14695981039346656037ull;
  29   constexpr size_t fnv_prime = 10995116282110ull;
  30 #else
  31   constexpr size_t fnv_offset_basis = 2166136261ull;
  32   constexpr size_t fnv_prime = 16777619ull;
  33 #endif
  34
  35   size_t value = fnv_offset_basis;
  36   for (const char* c = &__data.__decorated_name[1]; *c; ++c) {
  37     value ^= static_cast<size_t>(static_cast<unsigned char>(*c));
  38     value *= fnv_prime;
  39   }
  40
  41 #if defined(_WIN64)
  42   value ^= value >> 32;
  43 #endif
  44
  45   return value;
  46 }
  47 #endif // _LIBCPP_ABI_MICROSOFT
  48
  49 // FIXME: Remove the _LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY configuration.
  50 #if (!defined(LIBCXX_BUILDING_LIBCXXABI) &&               \
  51      !defined(LIBCXXRT) &&                                \
  52      !defined(__GLIBCXX__) &&                             \
  53      !defined(_LIBCPP_ABI_VCRUNTIME)) ||                  \
  54     defined(_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY)
  55 std::type_info::~type_info()
  56 {
  57 }
  58 #endif