libstdc++: Backport std::basic_string::_S_allocate from trunk

This is a backport of r14-739-gc62e945492afbb to keep the exported
symbol list consistent between trunk and gcc-13. The new assertions from
that commit are not part of this backport.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver: Export basic_string::_S_allocate.
	* include/bits/basic_string.h: (basic_string::_Alloc_traits_impl):
	Remove class template.
	(basic_string::_S_allocate): New static member function.
	(basic_string::assign): Use _S_allocate.
	* include/bits/basic_string.tcc (basic_string::_M_create)
	(basic_string::reserve, basic_string::_M_replace): Likewise.

(cherry picked from commit c62e945492afbbd2a09896fc7b0b07f7e719a606)
This commit is contained in:
Jonathan Wakely 2023-05-10 21:30:10 +01:00
parent ca2b591c5d
commit 0d5a359140
3 changed files with 24 additions and 36 deletions

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@ -1759,7 +1759,9 @@ GLIBCXX_3.4.21 {
#endif
# ABI-tagged std::basic_string
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE1[01]**;
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE10_M_[dr]*;
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE10_S_compareE[jmy][jmy];
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE11_M_capacityE[jmy];
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE12_Alloc_hiderC[12]EP[cw]RKS3_;
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE12_M*;
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE13*;
@ -2516,6 +2518,7 @@ GLIBCXX_3.4.31 {
GLIBCXX_3.4.32 {
_ZSt21ios_base_library_initv;
_ZNSt7__cxx1112basic_stringI[cw]St11char_traitsI[cw]ESaI[cw]EE11_S_allocateERS3_[jmy];
} GLIBCXX_3.4.31;
# Symbols in the support library (libsupc++) have their own tag.

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@ -89,36 +89,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
rebind<_CharT>::other _Char_alloc_type;
#if __cpp_lib_constexpr_string < 201907L
typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits;
#else
template<typename _Traits2, typename _Dummy_for_PR85282>
struct _Alloc_traits_impl : __gnu_cxx::__alloc_traits<_Char_alloc_type>
{
typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Base;
[[__gnu__::__always_inline__]]
static constexpr typename _Base::pointer
allocate(_Char_alloc_type& __a, typename _Base::size_type __n)
{
pointer __p = _Base::allocate(__a, __n);
if (std::is_constant_evaluated())
// Begin the lifetime of characters in allocated storage.
for (size_type __i = 0; __i < __n; ++__i)
std::construct_at(__builtin_addressof(__p[__i]));
return __p;
}
};
template<typename _Dummy_for_PR85282>
struct _Alloc_traits_impl<char_traits<_CharT>, _Dummy_for_PR85282>
: __gnu_cxx::__alloc_traits<_Char_alloc_type>
{
// std::char_traits begins the lifetime of characters.
};
using _Alloc_traits = _Alloc_traits_impl<_Traits, void>;
#endif
// Types:
public:
@ -149,6 +120,22 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
#endif
private:
static _GLIBCXX20_CONSTEXPR pointer
_S_allocate(_Char_alloc_type& __a, size_type __n)
{
pointer __p = _Alloc_traits::allocate(__a, __n);
#if __cpp_lib_constexpr_string >= 201907L
// std::char_traits begins the lifetime of characters,
// but custom traits might not, so do it here.
if constexpr (!is_same_v<_Traits, char_traits<_CharT>>)
if (std::__is_constant_evaluated())
// Begin the lifetime of characters in allocated storage.
for (size_type __i = 0; __i < __n; ++__i)
std::construct_at(__builtin_addressof(__p[__i]));
#endif
return __p;
}
#if __cplusplus >= 201703L
// A helper type for avoiding boiler-plate.
typedef basic_string_view<_CharT, _Traits> __sv_type;
@ -1596,7 +1583,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
const auto __len = __str.size();
auto __alloc = __str._M_get_allocator();
// If this allocation throws there are no effects:
auto __ptr = _Alloc_traits::allocate(__alloc, __len + 1);
auto __ptr = _S_allocate(__alloc, __len + 1);
_M_destroy(_M_allocated_capacity);
_M_data(__ptr);
_M_capacity(__len);

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@ -152,7 +152,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// NB: Need an array of char_type[__capacity], plus a terminating
// null char_type() element.
return _Alloc_traits::allocate(_M_get_allocator(), __capacity + 1);
return _S_allocate(_M_get_allocator(), __capacity + 1);
}
// NB: This is the special case for Input Iterators, used in
@ -376,8 +376,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
else if (__length < __capacity)
try
{
pointer __tmp
= _Alloc_traits::allocate(_M_get_allocator(), __length + 1);
pointer __tmp = _S_allocate(_M_get_allocator(), __length + 1);
this->_S_copy(__tmp, _M_data(), __length + 1);
_M_dispose();
_M_data(__tmp);
@ -521,8 +520,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
{
auto __newp = _Alloc_traits::allocate(_M_get_allocator(),
__new_size);
auto __newp = _S_allocate(_M_get_allocator(), __new_size);
_S_copy(__newp, this->_M_data(), __pos);
_S_copy(__newp + __pos, __s, __len2);
_S_copy(__newp + __pos + __len2, __p + __len1, __how_much);