The memmove optimizations for std::uninitialized_copy/fill/_n will compile even if the type is not copy constructible, because std::copy doesn't require copy construction to work. But the uninitialized algorithms do require it.
This adds explicit static assertions to ensure we don't allow ill-formed initializations. PR libstdc++/89164 * include/bits/stl_uninitialized.h (uninitialized_copy): Add static assertion. * testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc: New test. * testsuite/20_util/specialized_algorithms/uninitialized_copy_n/ 89164.cc: New test. * testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc: New test. * testsuite/20_util/specialized_algorithms/uninitialized_fill_n/ 89164.cc: New test. * testsuite/23_containers/vector/cons/89164.cc: New test. This fixes an accepts-invalid bug in vector (and probably other containers, I didn't check) but I don't see any great urgency to fix this now. I'll wait for stage 1.
commit 6f61f77f40546fdf47aaf6320d141f380a0c7d49 Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue Feb 5 14:12:27 2019 +0000 PR libstdc++/89164 enforce constraints for uninitialized algos The memmove optimizations for std::uninitialized_copy/fill/_n will compile even if the type is not copy constructible, because std::copy doesn't require copy construction to work. But the uninitialized algorithms do require it. This adds explicit static assertions to ensure we don't allow ill-formed initializations. PR libstdc++/89164 * include/bits/stl_uninitialized.h (uninitialized_copy): Add static assertion. * testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc: New test. * testsuite/20_util/specialized_algorithms/uninitialized_copy_n/ 89164.cc: New test. * testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc: New test. * testsuite/20_util/specialized_algorithms/uninitialized_fill_n/ 89164.cc: New test. * testsuite/23_containers/vector/cons/89164.cc: New test. diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h index 2b69e658fe8..646d15b2164 100644 --- a/libstdc++-v3/include/bits/stl_algobase.h +++ b/libstdc++-v3/include/bits/stl_algobase.h @@ -301,7 +301,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // (2) If we're using random access iterators, then write the loop as // a for loop with an explicit count. - template<bool, bool, typename> + template<bool _IsMove, bool _IsSimple, typename _Category> struct __copy_move { template<typename _II, typename _OI> diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h index 0d42b253df1..f5ca74329e2 100644 --- a/libstdc++-v3/include/bits/stl_uninitialized.h +++ b/libstdc++-v3/include/bits/stl_uninitialized.h @@ -122,9 +122,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #if __cplusplus < 201103L const bool __assignable = true; #else - // trivial types can have deleted assignment + // Trivial types can have deleted copy constructor, but the std::copy + // optimization that uses memmove would happily "copy" them anyway. + static_assert(is_constructible<_ValueType2, decltype(*__first)>::value, + "result type must be constructible from value type of input range"); + typedef typename iterator_traits<_InputIterator>::reference _RefType1; typedef typename iterator_traits<_ForwardIterator>::reference _RefType2; + // Trivial types can have deleted assignment, so using std::copy + // would be ill-formed. Require assignability before using std::copy: const bool __assignable = is_assignable<_RefType2, _RefType1>::value; #endif @@ -186,7 +192,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #if __cplusplus < 201103L const bool __assignable = true; #else - // trivial types can have deleted assignment + // Trivial types can have deleted copy constructor, but the std::fill + // optimization that uses memmove would happily "copy" them anyway. + static_assert(is_constructible<_ValueType, const _Tp&>::value, + "result type must be constructible from input type"); + + // Trivial types can have deleted assignment, so using std::fill + // would be ill-formed. Require assignability before using std::fill: const bool __assignable = is_copy_assignable<_ValueType>::value; #endif @@ -248,7 +260,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #if __cplusplus < 201103L const bool __assignable = true; #else - // trivial types can have deleted assignment + // Trivial types can have deleted copy constructor, but the std::fill + // optimization that uses memmove would happily "copy" them anyway. + static_assert(is_constructible<_ValueType, const _Tp&>::value, + "result type must be constructible from input type"); + + // Trivial types can have deleted assignment, so using std::fill + // would be ill-formed. Require assignability before using std::fill: const bool __assignable = is_copy_assignable<_ValueType>::value; #endif return __uninitialized_fill_n<__is_trivial(_ValueType) && __assignable>:: diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc new file mode 100644 index 00000000000..0221c018362 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc @@ -0,0 +1,37 @@ +// 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++11 } } + +#include <vector> + +// PR libstdc++/89164 + +struct X +{ + X() = default; + X(const X&) = delete; +}; + +void test01() +{ + X x[1]; + alignas(X) unsigned char buf[sizeof(X)]; + X* p = (X*)buf; + + std::uninitialized_copy(x, x+1, p); // { dg-error "must be constructible" } +} diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc new file mode 100644 index 00000000000..c0f94d4fe5e --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc @@ -0,0 +1,34 @@ +// 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++11 } } + +#include <vector> + +struct X { + X() = default; + X(const X&) = delete; +}; + +void test01() +{ + X x[1]; + alignas(X) unsigned char buf[sizeof(X)]; + X* p = (X*)buf; + + std::uninitialized_copy_n(x, 1, p); // { dg-error "must be constructible" } +} diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc new file mode 100644 index 00000000000..7b4d2a29b6a --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc @@ -0,0 +1,34 @@ +// 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++11 } } + +#include <vector> + +struct X { + X() = default; + X(const X&) = delete; +}; + +void f() +{ + X x; + alignas(X) unsigned char buf[sizeof(X)]; + X* p = (X*)buf; + + std::uninitialized_fill(p, p+1, x); // { dg-error "must be constructible" } +} diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc new file mode 100644 index 00000000000..f251cb7ebd2 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc @@ -0,0 +1,34 @@ +// 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++11 } } + +#include <vector> + +struct X { + X() = default; + X(const X&) = delete; +}; + +void test01() +{ + X x; + alignas(X) unsigned char buf[sizeof(X)]; + X* p = (X*)buf; + + std::uninitialized_fill_n(p, 1, x); // { dg-error "must be constructible" } +} diff --git a/libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc b/libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc new file mode 100644 index 00000000000..c5c1ca1432b --- /dev/null +++ b/libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc @@ -0,0 +1,44 @@ +// 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++11 } } + +#include <vector> + +// PR libstdc++/89164 + +struct X +{ + X() = default; + X(const X&) = delete; +}; + +void test01() +{ + X x[1]; + // Should not be able to create vector using uninitialized_copy: + std::vector<X> v1{x, x+1}; // { dg-error "constructible from value" } + + // Should not be able to create vector using uninitialized_fill_n: + std::vector<X> v2{2u, X{}}; // { dg-error "constructible from input" } + +#if __cplusplus >= 201703L + // Can create initializer_list<X> with C++17 guaranteed copy elision, + // but shouldn't be able to copy from it with uninitialized_copy: + std::vector<X> v3{X{}, X{}, X{}}; // { dg-error "constructible from value" } +#endif +}