Tested on Linux x86_64 basic_string spurious use of a default constructible allocator - LWG2788
2019-05-27 Nina Dinka Ranns <dinka.ra...@gmail.com> basic_string spurious use of a default constructible allocator - LWG2788 * bits/basic_string.tcc: (_M_replace_dispatch()): string temporary now constructed with the current allocator * testsuite/21_strings/basic_string/allocator/char/lwg2788.cc: New * testsuite/21_strings/basic_string/allocator/wchar_t/lwg2788.cc: New
Index: libstdc++-v3/include/bits/basic_string.tcc =================================================================== --- libstdc++-v3/include/bits/basic_string.tcc (revision 271509) +++ libstdc++-v3/include/bits/basic_string.tcc (working copy) @@ -381,7 +381,9 @@ _InputIterator __k1, _InputIterator __k2, std::__false_type) { - const basic_string __s(__k1, __k2); + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 2788. unintentionally require a default constructible allocator + const basic_string __s(__k1, __k2, this->get_allocator()); const size_type __n1 = __i2 - __i1; return _M_replace(__i1 - begin(), __n1, __s._M_data(), __s.size()); Index: libstdc++-v3/testsuite/20_util/nonesuch/nonesuch.cc =================================================================== --- libstdc++-v3/testsuite/20_util/nonesuch/nonesuch.cc (revision 271509) +++ libstdc++-v3/testsuite/20_util/nonesuch/nonesuch.cc (nonexistent) @@ -1,39 +0,0 @@ -// 2019-05-14 Nina Dinka Ranns <dinka.ra...@gmail.com> -// Copyright (C) 2019 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. - -// You should have received a copy of the GNU General Public License along -// with this library; see the file COPYING3. If not see -// <http://www.gnu.org/licenses/>. - -// { dg-do compile { target c++14 } } - -#include <type_traits> -// Example taken from LWG2960 - -using std::__nonesuch; -struct such {}; -void f(const such&){}; -void f(const std::__nonesuch&); - -int main(){ - static_assert(!std::is_default_constructible<__nonesuch>::value, - "__nonesuch is default constructible"); - static_assert(!std::is_copy_constructible<__nonesuch>::value, - "__nonesuch is copy constructible"); - static_assert(!std::is_assignable<__nonesuch, __nonesuch>::value, - "__nonesuch is assignable"); - static_assert(!std::is_destructible<__nonesuch>::value, - "__nonesuch is destructible"); - f({}); -} Index: libstdc++-v3/testsuite/21_strings/basic_string/allocator/char/lwg2788.cc =================================================================== --- libstdc++-v3/testsuite/21_strings/basic_string/allocator/char/lwg2788.cc (nonexistent) +++ libstdc++-v3/testsuite/21_strings/basic_string/allocator/char/lwg2788.cc (working copy) @@ -0,0 +1,84 @@ +//{ dg-do run { target c++11 } } + +// 2019-05-27 Nina Dinka Ranns <dinka.ra...@gmail.com> +// +// Copyright (C) 2015-2019 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. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +#include <string> +#include <testsuite_hooks.h> + +using C = char; +using traits = std::char_traits<C>; +int constructCount = 0; + +static void resetCounter() +{ + constructCount = 0; +} + +template <class Tp> +struct TestAllocator +{ + typedef Tp value_type; + using size_type = unsigned; + + TestAllocator() noexcept { constructCount++; } + + template <class T> + TestAllocator(const TestAllocator<T>&) {} + + Tp *allocate(std::size_t n) + { return std::allocator<Tp>().allocate(n); } + + void deallocate(Tp *p, std::size_t n) + { std::allocator<Tp>().deallocate(p, n); } + +}; + +template <class T, class U> +bool operator==(const TestAllocator<T>&, const TestAllocator<U>&) +{ return true; } +template <class T, class U> +bool operator!=(const TestAllocator<T>&, const TestAllocator<U>&) +{ return false; } + +void test01() +{ + typedef TestAllocator<C> alloc_type; + typedef std::basic_string<C, traits, alloc_type> test_type; + test_type v1{alloc_type()}; + std::string v2{"some_content"}; + + resetCounter(); + v1.assign(v2.begin(),v2.end()); + VERIFY( constructCount == 0); + + v1.append(v2.begin(),v2.end()); + VERIFY( constructCount == 0); + + v1.insert(v1.begin(),v1.begin(),v1.end()); + VERIFY( constructCount == 0); + + v1.replace(v1.begin(),v1.end(),v1.begin(),v1.end()); + VERIFY( constructCount == 0); +} +int main() +{ + test01(); + return 0; +} Index: libstdc++-v3/testsuite/21_strings/basic_string/allocator/wchar_t/lwg2788.cc =================================================================== --- libstdc++-v3/testsuite/21_strings/basic_string/allocator/wchar_t/lwg2788.cc (nonexistent) +++ libstdc++-v3/testsuite/21_strings/basic_string/allocator/wchar_t/lwg2788.cc (working copy) @@ -0,0 +1,84 @@ +//{ dg-do run { target c++11 } } + +// 2019-05-27 Nina Dinka Ranns <dinka.ra...@gmail.com> +// +// Copyright (C) 2015-2019 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. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +#include <string> +#include <testsuite_hooks.h> + +using C = wchar_t; +using traits = std::char_traits<C>; +int constructCount = 0; + +static void resetCounter() +{ + constructCount = 0; +} + +template <class Tp> +struct TestAllocator +{ + typedef Tp value_type; + using size_type = unsigned; + + TestAllocator() noexcept { constructCount++; } + + template <class T> + TestAllocator(const TestAllocator<T>&) {} + + Tp *allocate(std::size_t n) + { return std::allocator<Tp>().allocate(n); } + + void deallocate(Tp *p, std::size_t n) + { std::allocator<Tp>().deallocate(p, n); } + +}; + +template <class T, class U> +bool operator==(const TestAllocator<T>&, const TestAllocator<U>&) +{ return true; } +template <class T, class U> +bool operator!=(const TestAllocator<T>&, const TestAllocator<U>&) +{ return false; } + +void test01() +{ + typedef TestAllocator<C> alloc_type; + typedef std::basic_string<C, traits, alloc_type> test_type; + test_type v1{alloc_type()}; + std::wstring v2{L"some_content"}; + + resetCounter(); + v1.assign(v2.begin(),v2.end()); + VERIFY( constructCount == 0); + + v1.append(v2.begin(),v2.end()); + VERIFY( constructCount == 0); + + v1.insert(v1.begin(),v1.begin(),v1.end()); + VERIFY( constructCount == 0); + + v1.replace(v1.begin(),v1.end(),v1.begin(),v1.end()); + VERIFY( constructCount == 0); +} +int main() +{ + test01(); + return 0; +}