1// Helper for accessing __cxx11::string from the ABI -*- C++ -*-
2
3// Copyright (C) 2014-2020 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25
26#define _GLIBCXX_USE_CXX11_ABI 1
27#define __sso_string __sso_stringxxx
28#include <string>
29#include <stdexcept>
30#undef __sso_string
31
32#if ! _GLIBCXX_USE_DUAL_ABI
33# error This file should not be compiled for this configuration.
34#endif
35
36namespace std _GLIBCXX_VISIBILITY(default)
37{
38_GLIBCXX_BEGIN_NAMESPACE_VERSION
39
40#pragma GCC diagnostic push
41#pragma GCC diagnostic ignored "-Wabi-tag"
42  // Redefine __sso_string so that we can define and export its members
43  // in terms of the SSO std::string.
44  struct __sso_string
45  {
46    struct __str
47    {
48      const char* _M_p;
49      size_t _M_string_length;
50      char _M_local_buf[16];
51    };
52
53    union {
54      __str _M_s;
55      char _M_bytes[sizeof(_M_s)];
56      std::string _M_str;
57    };
58
59    __sso_string();
60    __sso_string(const std::string& s);
61    __sso_string(const char*, size_t n);
62    __sso_string(const __sso_string&) noexcept;
63    __sso_string& operator=(const __sso_string&) noexcept;
64    ~__sso_string();
65    __sso_string(__sso_string&&) noexcept;
66    __sso_string& operator=(__sso_string&&) noexcept;
67  };
68#pragma GCC diagnostic pop
69
70  __sso_string::__sso_string() : _M_str() { }
71
72#if _GLIBCXX_USE_CXX11_ABI
73  static_assert(sizeof(__sso_string) == sizeof(std::string),
74                "sizeof(std::string) has changed");
75  static_assert(alignof(__sso_string) == alignof(std::string),
76                "alignof(std::string) has changed");
77
78  // This constructor is defined in src/c++11/cow-stdexcept.cc for COW strings
79  __sso_string::__sso_string(const std::string& s) : _M_str(s) { }
80#endif
81
82  __sso_string::__sso_string(const char* s, size_t n) : _M_str(s, n) { }
83
84  __sso_string::__sso_string(const __sso_string& s) noexcept
85  : _M_str(s._M_str) { }
86
87  __sso_string&
88  __sso_string::operator=(const __sso_string& s) noexcept
89  {
90    _M_str = s._M_str;
91    return *this;
92  }
93
94  __sso_string::~__sso_string() { _M_str.~basic_string(); }
95
96  __sso_string::__sso_string(__sso_string&& s) noexcept
97  : _M_str(std::move(s._M_str)) { }
98
99  __sso_string&
100  __sso_string::operator=(__sso_string&& s) noexcept
101  {
102    _M_str = std::move(s._M_str);
103    return *this;
104  }
105
106_GLIBCXX_END_NAMESPACE_VERSION
107} // namespace
108