By using std::is_trivially_destructible instead of the old
__has_trivial_destructor built-in we no longer need the static_assert to
deal with types with deleted destructors. All non-destructible types,
including those with deleted destructors, will now give user-friendly
diagnostics that clearly explain the problem.
Also combine the _Destroy_aux and _Destroy_n_aux class templates used
for C++98 into one, so that we perform fewer expensive class template
instantiations.
libstdc++-v3/ChangeLog:
PR libstdc++/120390
* include/bits/stl_construct.h (_Destroy_aux::__destroy_n): New
static member function.
(_Destroy_aux<true>::__destroy_n): Likewise.
(_Destroy_n_aux): Remove.
(_Destroy(ForwardIterator, ForwardIterator)): Remove
static_assert. Use is_trivially_destructible instead of
__has_trivial_destructor.
(_Destroy_n): Likewise. Use _Destroy_aux::__destroy_n instead of
_Destroy_n_aux::__destroy_n.
*
testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_neg.cc:
Adjust dg-error strings. Move destroy_n tests to ...
*
testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_n_neg.cc:
New test.
* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
Adjust dg-error strings.
* testsuite/23_containers/vector/cons/destructible_neg.cc:
Likewise.
---
Tested x86_64-linux.
libstdc++-v3/include/bits/stl_construct.h | 56 +++++++-----------
.../memory_management_tools/destroy_n_neg.cc | 59 +++++++++++++++++++
.../memory_management_tools/destroy_neg.cc | 20 +++++--
.../vector/cons/destructible_debug_neg.cc | 7 +--
.../vector/cons/destructible_neg.cc | 7 +--
5 files changed, 98 insertions(+), 51 deletions(-)
create mode 100644
libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_n_neg.cc
diff --git a/libstdc++-v3/include/bits/stl_construct.h
b/libstdc++-v3/include/bits/stl_construct.h
index 23b8fb754710..3ac75715e0e0 100644
--- a/libstdc++-v3/include/bits/stl_construct.h
+++ b/libstdc++-v3/include/bits/stl_construct.h
@@ -181,6 +181,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
for (; __first != __last; ++__first)
std::_Destroy(std::__addressof(*__first));
}
+
+ template<typename _ForwardIterator, typename _Size>
+ static _GLIBCXX20_CONSTEXPR _ForwardIterator
+ __destroy_n(_ForwardIterator __first, _Size __count)
+ {
+ for (; __count > 0; (void)++__first, --__count)
+ std::_Destroy(std::__addressof(*__first));
+ return __first;
+ }
};
template<>
@@ -189,6 +198,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _ForwardIterator>
static void
__destroy(_ForwardIterator, _ForwardIterator) { }
+
+ template<typename _ForwardIterator, typename _Size>
+ static _ForwardIterator
+ __destroy_n(_ForwardIterator __first, _Size __count)
+ {
+ std::advance(__first, __count);
+ return __first;
+ }
};
#endif
@@ -204,10 +221,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
typedef typename iterator_traits<_ForwardIterator>::value_type
_Value_type;
#if __cplusplus >= 201103L
- // A deleted destructor is trivial, this ensures we reject such types:
- static_assert(is_destructible<_Value_type>::value,
- "value type is destructible");
- if constexpr (!__has_trivial_destructor(_Value_type))
+ if constexpr (!is_trivially_destructible<_Value_type>::value)
for (; __first != __last; ++__first)
std::_Destroy(std::__addressof(*__first));
#if __cpp_constexpr_dynamic_alloc // >= C++20
@@ -221,33 +235,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif
}
-#if __cplusplus < 201103L
- template<bool>
- struct _Destroy_n_aux
- {
- template<typename _ForwardIterator, typename _Size>
- static _GLIBCXX20_CONSTEXPR _ForwardIterator
- __destroy_n(_ForwardIterator __first, _Size __count)
- {
- for (; __count > 0; (void)++__first, --__count)
- std::_Destroy(std::__addressof(*__first));
- return __first;
- }
- };
-
- template<>
- struct _Destroy_n_aux<true>
- {
- template<typename _ForwardIterator, typename _Size>
- static _ForwardIterator
- __destroy_n(_ForwardIterator __first, _Size __count)
- {
- std::advance(__first, __count);
- return __first;
- }
- };
-#endif
-
/**
* Destroy a range of objects. If the value_type of the object has
* a trivial destructor, the compiler should optimize all of this
@@ -260,10 +247,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
typedef typename iterator_traits<_ForwardIterator>::value_type
_Value_type;
#if __cplusplus >= 201103L
- // A deleted destructor is trivial, this ensures we reject such types:
- static_assert(is_destructible<_Value_type>::value,
- "value type is destructible");
- if constexpr (!__has_trivial_destructor(_Value_type))
+ if constexpr (!is_trivially_destructible<_Value_type>::value)
for (; __count > 0; (void)++__first, --__count)
std::_Destroy(std::__addressof(*__first));
#if __cpp_constexpr_dynamic_alloc // >= C++20
@@ -275,7 +259,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
std::advance(__first, __count);
return __first;
#else
- return std::_Destroy_n_aux<__has_trivial_destructor(_Value_type)>::
+ return std::_Destroy_aux<__has_trivial_destructor(_Value_type)>::
__destroy_n(__first, __count);
#endif
}
diff --git
a/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_n_neg.cc
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_n_neg.cc
new file mode 100644
index 000000000000..12c0dc575ccf
--- /dev/null
+++
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_n_neg.cc
@@ -0,0 +1,59 @@
+// Copyright (C) 2017-2025 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++17 } }
+
+#include <memory>
+
+// This has a trivial destructor, but should not be destructible!
+struct DeletedDtor {
+ ~DeletedDtor() = delete;
+};
+
+void
+test01()
+{
+ alignas(DeletedDtor) unsigned char buf[sizeof(DeletedDtor)];
+ auto p = ::new (buf) DeletedDtor();
+ std::destroy_n(p, 1);
+}
+
+class PrivateDtor {
+ ~PrivateDtor() { }
+};
+
+void
+test02()
+{
+ alignas(PrivateDtor) unsigned char buf[sizeof(PrivateDtor)];
+ auto p = ::new (buf) PrivateDtor();
+ std::destroy_n(p, 1);
+}
+
+#if __cpp_constexpr_dynamic_alloc // >= C++20
+consteval bool
+test03()
+{
+ DeletedDtor* p = nullptr;
+ std::destroy_n(p, 0);
+ return true;
+}
+static_assert(test03());
+#endif
+
+// { dg-error "deleted function .*DeletedDtor" "" { target *-*-* } 0 }
+// { dg-error "PrivateDtor.* is private" "" { target *-*-* } 0 }
diff --git
a/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_neg.cc
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_neg.cc
index 5946a82de3bc..096f218ee2be 100644
---
a/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_neg.cc
+++
b/libstdc++-v3/testsuite/20_util/specialized_algorithms/memory_management_tools/destroy_neg.cc
@@ -29,8 +29,7 @@ test01()
{
alignas(DeletedDtor) unsigned char buf[sizeof(DeletedDtor)];
auto p = ::new (buf) DeletedDtor();
- std::destroy(p, p + 1); // { dg-error "here" }
- std::destroy_n(p, 1); // { dg-error "here" }
+ std::destroy(p, p + 1);
}
class PrivateDtor {
@@ -42,8 +41,19 @@ test02()
{
alignas(PrivateDtor) unsigned char buf[sizeof(PrivateDtor)];
auto p = ::new (buf) PrivateDtor();
- std::destroy(p, p + 1); // { dg-error "here" }
- std::destroy_n(p, 1); // { dg-error "here" }
+ std::destroy(p, p + 1);
}
-// { dg-error "value type is destructible" "" { target *-*-* } 0 }
+#if __cpp_constexpr_dynamic_alloc // >= C++20
+consteval bool
+test03()
+{
+ DeletedDtor* p = nullptr;
+ std::destroy(p, p);
+ return true;
+}
+static_assert(test03());
+#endif
+
+// { dg-error "deleted function .*DeletedDtor" "" { target *-*-* } 0 }
+// { dg-error "PrivateDtor.* is private" "" { target *-*-* } 0 }
diff --git
a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
index 61b99d34a1ca..e6689f7ea265 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
@@ -43,11 +43,8 @@ test02()
std::vector<PrivateDtor> v;
}
-// { dg-error "value type is destructible" "" { target *-*-* } 0 }
+// { dg-error "deleted function .*DeletedDtor" "" { target *-*-* } 0 }
+// { dg-error "PrivateDtor.* is private" "" { target *-*-* } 0 }
// In Debug Mode the "required from here" errors come from <debug/vector>
// { dg-error "required from here" "" { target *-*-* } 182 }
-
-// Needed because of PR c++/92193
-// { dg-prune-output "deleted function" }
-// { dg-prune-output "private within this context" }
diff --git
a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_neg.cc
b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_neg.cc
index 0807d158304c..2bd15bc68eec 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_neg.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_neg.cc
@@ -42,8 +42,5 @@ test02()
std::vector<PrivateDtor> v; // { dg-error "here" }
}
-// { dg-error "value type is destructible" "" { target *-*-* } 0 }
-
-// Needed because of PR c++/92193
-// { dg-prune-output "deleted function" }
-// { dg-prune-output "private within this context" }
+// { dg-error "deleted function .*DeletedDtor" "" { target *-*-* } 0 }
+// { dg-error "PrivateDtor.* is private" "" { target *-*-* } 0 }
--
2.49.0
