xref: /freebsd/contrib/llvm-project/libcxx/src/typeinfo.cpp (revision cb14a3fe5122c879eae1fb480ed7ce82a699ddb6)
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) && !defined(LIBCXXRT) && !defined(__GLIBCXX__) &&                             \
51      !defined(_LIBCPP_ABI_VCRUNTIME)) ||                                                                               \
52     defined(_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY)
53 std::type_info::~type_info() {}
54 #endif
55