gcc/libstdc++-v3/include/ext/pod_char_traits.h
Jonathan Wakely 4a88769c96 re PR libstdc++/65049 (Undefined behaviour with std::char_traits<char>)
PR libstdc++/65049
	* include/bits/char_traits.h (char_traits<char>::compare,
	char_traits<char>::find, char_traits<char>::move,
	char_traits<char>::copy, char_traits<char>::assign): Check for zero
	length.
	(char_traits<wchar_t>::compare, char_traits<wchar_t>::find,
	char_traits<wchar_t>::move, char_traits<wchar_t>::copy,
	char_traits<wchar_t>::assign): Likewise.
	(char_traits<char16_t>::move, char_traits<char16_t>::copy): Likewise.
	(char_traits<char32_t>::move, char_traits<char32_t>::copy): Likewise.
	* include/ext/pod_char_traits.h (char_traits<character<>>::move,
	char_traits<character<>>::copy): Likewise.
	* testsuite/21_strings/char_traits/requirements/char/65049.cc: New.
	* testsuite/21_strings/char_traits/requirements/char16_t/65049.cc:
	New.
	* testsuite/21_strings/char_traits/requirements/char32_t/65049.cc:
	New.
	* testsuite/21_strings/char_traits/requirements/wchar_t/65049.cc:
	New.

From-SVN: r227127
2015-08-24 14:43:54 +01:00

199 lines
5.4 KiB
C++

// POD character, std::char_traits specialization -*- C++ -*-
// Copyright (C) 2002-2015 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file ext/pod_char_traits.h
* This file is a GNU extension to the Standard C++ Library.
*/
// Gabriel Dos Reis <gdr@integrable-solutions.net>
// Benjamin Kosnik <bkoz@redhat.com>
#ifndef _POD_CHAR_TRAITS_H
#define _POD_CHAR_TRAITS_H 1
#pragma GCC system_header
#include <string>
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// POD character abstraction.
// NB: The char_type parameter is a subset of int_type, as to allow
// int_type to properly hold the full range of char_type values as
// well as EOF.
/// @brief A POD class that serves as a character abstraction class.
template<typename _Value, typename _Int, typename _St = std::mbstate_t>
struct character
{
typedef _Value value_type;
typedef _Int int_type;
typedef _St state_type;
typedef character<_Value, _Int, _St> char_type;
value_type value;
template<typename V2>
static char_type
from(const V2& v)
{
char_type ret = { static_cast<value_type>(v) };
return ret;
}
template<typename V2>
static V2
to(const char_type& c)
{
V2 ret = { static_cast<V2>(c.value) };
return ret;
}
};
template<typename _Value, typename _Int, typename _St>
inline bool
operator==(const character<_Value, _Int, _St>& lhs,
const character<_Value, _Int, _St>& rhs)
{ return lhs.value == rhs.value; }
template<typename _Value, typename _Int, typename _St>
inline bool
operator<(const character<_Value, _Int, _St>& lhs,
const character<_Value, _Int, _St>& rhs)
{ return lhs.value < rhs.value; }
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/// char_traits<__gnu_cxx::character> specialization.
template<typename _Value, typename _Int, typename _St>
struct char_traits<__gnu_cxx::character<_Value, _Int, _St> >
{
typedef __gnu_cxx::character<_Value, _Int, _St> char_type;
typedef typename char_type::int_type int_type;
typedef typename char_type::state_type state_type;
typedef fpos<state_type> pos_type;
typedef streamoff off_type;
static void
assign(char_type& __c1, const char_type& __c2)
{ __c1 = __c2; }
static bool
eq(const char_type& __c1, const char_type& __c2)
{ return __c1 == __c2; }
static bool
lt(const char_type& __c1, const char_type& __c2)
{ return __c1 < __c2; }
static int
compare(const char_type* __s1, const char_type* __s2, size_t __n)
{
for (size_t __i = 0; __i < __n; ++__i)
if (!eq(__s1[__i], __s2[__i]))
return lt(__s1[__i], __s2[__i]) ? -1 : 1;
return 0;
}
static size_t
length(const char_type* __s)
{
const char_type* __p = __s;
while (__p->value)
++__p;
return (__p - __s);
}
static const char_type*
find(const char_type* __s, size_t __n, const char_type& __a)
{
for (const char_type* __p = __s; size_t(__p - __s) < __n; ++__p)
if (*__p == __a)
return __p;
return 0;
}
static char_type*
move(char_type* __s1, const char_type* __s2, size_t __n)
{
if (__n == 0)
return __s1;
return static_cast<char_type*>
(__builtin_memmove(__s1, __s2, __n * sizeof(char_type)));
}
static char_type*
copy(char_type* __s1, const char_type* __s2, size_t __n)
{
if (__n == 0)
return __s1;
std::copy(__s2, __s2 + __n, __s1);
return __s1;
}
static char_type*
assign(char_type* __s, size_t __n, char_type __a)
{
std::fill_n(__s, __n, __a);
return __s;
}
static char_type
to_char_type(const int_type& __i)
{ return char_type::template from(__i); }
static int_type
to_int_type(const char_type& __c)
{ return char_type::template to<int_type>(__c); }
static bool
eq_int_type(const int_type& __c1, const int_type& __c2)
{ return __c1 == __c2; }
static int_type
eof()
{
int_type __r = { static_cast<typename __gnu_cxx::__conditional_type
<std::__is_integer<int_type>::__value,
int_type, int>::__type>(-1) };
return __r;
}
static int_type
not_eof(const int_type& __c)
{ return eq_int_type(__c, eof()) ? int_type() : __c; }
};
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif