From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id 9E26E3858D1E; Wed, 8 Nov 2023 13:18:14 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9E26E3858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1699449494; bh=MedkYhkfq7WmKOjtQqtcoAM/Ia/C1HVFf+Vd/cffN4I=; h=From:To:Subject:Date:From; b=mbQScnfbjd28bizZlbItEQJ6IlP2IrsnuGRpp/+4aJ1VDrIIPFXUQUd2JpGTLt0TE Hh/Piwv4eaIUgI13dDP+lR6EA9Ca2RqiqY5EjyyycsgwGdHRbUFDC4JaOVdCDgSoY6 ZxjXfB0sNNqDFkV0+xr1od7pQihCeoYHwm9xgmbs= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jonathan Wakely To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r13-8010] libstdc++: Split std::basic_string::_M_use_local_data into two functions X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/releases/gcc-13 X-Git-Oldrev: 4fdd5a7e6a2d81a06511278ccd903071a059e47f X-Git-Newrev: 4b4f1981cc687338cfbe8ec9ec2ea5a4ae6598a5 Message-Id: <20231108131814.9E26E3858D1E@sourceware.org> Date: Wed, 8 Nov 2023 13:18:14 +0000 (GMT) List-Id: https://gcc.gnu.org/g:4b4f1981cc687338cfbe8ec9ec2ea5a4ae6598a5 commit r13-8010-g4b4f1981cc687338cfbe8ec9ec2ea5a4ae6598a5 Author: Jonathan Wakely Date: Fri Sep 29 12:12:22 2023 +0100 libstdc++: Split std::basic_string::_M_use_local_data into two functions This splits out the activate-the-union-member-for-constexpr logic from _M_use_local_data, so that it can be used separately in cases that don't need to use std::pointer_traits::pointer_to to obtain the return value. This leaves only three uses of _M_use_local_data() which are all of the same form: __s._M_data(_M_use_local_data()); __s._M_set_length(0); We could remove _M_use_local_data() and change those three places to use a new _M_reset() function that does: _M_init_local_buf(); _M_data(_M_local_data()); _M_set_length(0); This is left for a future change. libstdc++-v3/ChangeLog: * include/bits/basic_string.h (_M_init_local_buf()): New function. (_M_use_local_data()): Use _M_init_local_buf. (basic_string(), basic_string(const Alloc&)) (basic_string(basic_string&&)) (basic_string(basic_string&&, const Alloc&)): Use _M_init_local_buf instead of _M_use_local_data(). * include/bits/basic_string.tcc (swap(basic_string&)) (_M_construct(InIter, InIter, input_iterator_tag)) (_M_construct(InIter, InIter, forward_iterator_tag)) (_M_construct(size_type, CharT), reserve()): Likewise. (cherry picked from commit 405a4140fc30bce86b1ec885a98bb17704e0c8c6) Diff: --- libstdc++-v3/include/bits/basic_string.h | 22 ++++++++++++++++------ libstdc++-v3/include/bits/basic_string.tcc | 19 ++++++++++--------- 2 files changed, 26 insertions(+), 15 deletions(-) diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h index 11b62af8fb2..b73991d96da 100644 --- a/libstdc++-v3/include/bits/basic_string.h +++ b/libstdc++-v3/include/bits/basic_string.h @@ -344,13 +344,23 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 // Ensure that _M_local_buf is the active member of the union. __attribute__((__always_inline__)) _GLIBCXX14_CONSTEXPR - pointer - _M_use_local_data() _GLIBCXX_NOEXCEPT + void + _M_init_local_buf() _GLIBCXX_NOEXCEPT { #if __cpp_lib_is_constant_evaluated if (std::is_constant_evaluated()) for (size_type __i = 0; __i <= _S_local_capacity; ++__i) _M_local_buf[__i] = _CharT(); +#endif + } + + __attribute__((__always_inline__)) + _GLIBCXX14_CONSTEXPR + pointer + _M_use_local_data() _GLIBCXX_NOEXCEPT + { +#if __cpp_lib_is_constant_evaluated + _M_init_local_buf(); #endif return _M_local_data(); } @@ -513,7 +523,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Alloc>::value) : _M_dataplus(_M_local_data()) { - _M_use_local_data(); + _M_init_local_buf(); _M_set_length(0); } @@ -525,7 +535,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 basic_string(const _Alloc& __a) _GLIBCXX_NOEXCEPT : _M_dataplus(_M_local_data(), __a) { - _M_use_local_data(); + _M_init_local_buf(); _M_set_length(0); } @@ -669,7 +679,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 { if (__str._M_is_local()) { - (void)_M_use_local_data(); + _M_init_local_buf(); traits_type::copy(_M_local_buf, __str._M_local_buf, __str.length() + 1); } @@ -709,7 +719,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 { if (__str._M_is_local()) { - (void)_M_use_local_data(); + _M_init_local_buf(); traits_type::copy(_M_local_buf, __str._M_local_buf, __str.length() + 1); _M_length(__str.length()); diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc index 3495a69df6b..d7560f594c0 100644 --- a/libstdc++-v3/include/bits/basic_string.tcc +++ b/libstdc++-v3/include/bits/basic_string.tcc @@ -79,7 +79,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } else if (__s.length()) { - (void)_M_use_local_data(); + _M_init_local_buf(); traits_type::copy(_M_local_buf, __s._M_local_buf, __s.length() + 1); _M_length(__s.length()); @@ -88,7 +88,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } else if (length()) { - (void)__s._M_use_local_data(); + __s._M_init_local_buf(); traits_type::copy(__s._M_local_buf, _M_local_buf, length() + 1); __s._M_length(length()); @@ -99,7 +99,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION else { const size_type __tmp_capacity = __s._M_allocated_capacity; - (void)__s._M_use_local_data(); + __s._M_init_local_buf(); traits_type::copy(__s._M_local_buf, _M_local_buf, length() + 1); _M_data(__s._M_data()); @@ -111,7 +111,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION const size_type __tmp_capacity = _M_allocated_capacity; if (__s._M_is_local()) { - (void)_M_use_local_data(); + _M_init_local_buf(); traits_type::copy(_M_local_buf, __s._M_local_buf, __s.length() + 1); __s._M_data(_M_data()); @@ -174,11 +174,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION size_type __len = 0; size_type __capacity = size_type(_S_local_capacity); - pointer __p = _M_use_local_data(); + _M_init_local_buf(); while (__beg != __end && __len < __capacity) { - __p[__len++] = *__beg; + _M_local_buf[__len++] = *__beg; ++__beg; } @@ -230,7 +230,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _M_capacity(__dnew); } else - _M_use_local_data(); + _M_init_local_buf(); // Check for out_of_range and length_error exceptions. struct _Guard @@ -263,7 +263,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _M_capacity(__n); } else - _M_use_local_data(); + _M_init_local_buf(); if (__n) this->_S_assign(_M_data(), __n, __c); @@ -372,7 +372,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION if (__length <= size_type(_S_local_capacity)) { - this->_S_copy(_M_use_local_data(), _M_data(), __length + 1); + _M_init_local_buf(); + this->_S_copy(_M_local_buf, _M_data(), __length + 1); _M_destroy(__capacity); _M_data(_M_local_data()); }