mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
868af3f950
You can now use the hardest fastest and most dangerous language there is with Cosmopolitan. So far about 75% of LLVM libcxx has been added. A few breaking changes needed to be made to help this go smoothly. - Rename nothrow to dontthrow - Rename nodiscard to dontdiscard - Add some libm functions, e.g. lgamma, nan, etc. - Change intmax_t from int128 to int64 like everything else - Introduce %jjd formatting directive for int128_t - Introduce strtoi128(), strtou128(), etc. - Rename bsrmax() to bsr128() Some of the templates that should be working currently are std::vector, std::string, std::map, std::set, std::deque, etc.
114 lines
3.1 KiB
C++
114 lines
3.1 KiB
C++
//===------------------------ __refstring ---------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP_REFSTRING_H
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#define _LIBCPP_REFSTRING_H
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#include "third_party/libcxx/__config"
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#include "third_party/libcxx/stdexcept"
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#include "third_party/libcxx/cstddef"
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#include "third_party/libcxx/cstring"
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#include "third_party/libcxx/atomic_support.hh"
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_LIBCPP_BEGIN_NAMESPACE_STD
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namespace __refstring_imp {
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namespace {
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typedef int count_t;
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struct _Rep_base {
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std::size_t len;
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std::size_t cap;
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count_t count;
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};
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inline _Rep_base* rep_from_data(const char* data_) noexcept {
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char* data = const_cast<char*>(data_);
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return reinterpret_cast<_Rep_base*>(data - sizeof(_Rep_base));
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}
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inline char* data_from_rep(_Rep_base* rep) noexcept {
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char* data = reinterpret_cast<char*>(rep);
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return data + sizeof(*rep);
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}
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#if defined(__APPLE__)
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inline const char* compute_gcc_empty_string_storage() _NOEXCEPT {
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void* handle = dlopen("/usr/lib/libstdc++.6.dylib", RTLD_NOLOAD);
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if (handle == nullptr)
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return nullptr;
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void* sym = dlsym(handle, "_ZNSs4_Rep20_S_empty_rep_storageE");
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if (sym == nullptr)
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return nullptr;
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return data_from_rep(reinterpret_cast<_Rep_base*>(sym));
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}
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inline const char* get_gcc_empty_string_storage() _NOEXCEPT {
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static const char* p = compute_gcc_empty_string_storage();
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return p;
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}
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#endif
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} // namespace
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} // namespace __refstring_imp
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using namespace __refstring_imp;
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inline __libcpp_refstring::__libcpp_refstring(const char* msg) {
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std::size_t len = strlen(msg);
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_Rep_base* rep =
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static_cast<_Rep_base*>(::operator new(sizeof(*rep) + len + 1));
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rep->len = len;
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rep->cap = len;
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rep->count = 0;
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char* data = data_from_rep(rep);
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std::memcpy(data, msg, len + 1);
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__imp_ = data;
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}
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inline __libcpp_refstring::__libcpp_refstring(
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const __libcpp_refstring& s) _NOEXCEPT : __imp_(s.__imp_) {
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if (__uses_refcount())
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__libcpp_atomic_add(&rep_from_data(__imp_)->count, 1);
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}
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inline __libcpp_refstring&
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__libcpp_refstring::operator=(__libcpp_refstring const& s) _NOEXCEPT {
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bool adjust_old_count = __uses_refcount();
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struct _Rep_base* old_rep = rep_from_data(__imp_);
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__imp_ = s.__imp_;
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if (__uses_refcount())
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__libcpp_atomic_add(&rep_from_data(__imp_)->count, 1);
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if (adjust_old_count) {
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if (__libcpp_atomic_add(&old_rep->count, count_t(-1)) < 0) {
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::operator delete(old_rep);
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}
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}
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return *this;
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}
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inline __libcpp_refstring::~__libcpp_refstring() {
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if (__uses_refcount()) {
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_Rep_base* rep = rep_from_data(__imp_);
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if (__libcpp_atomic_add(&rep->count, count_t(-1)) < 0) {
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::operator delete(rep);
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}
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}
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}
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inline bool __libcpp_refstring::__uses_refcount() const {
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#ifdef __APPLE__
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return __imp_ != get_gcc_empty_string_storage();
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#else
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return true;
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#endif
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}
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_LIBCPP_END_NAMESPACE_STD
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#endif //_LIBCPP_REFSTRING_H
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