[gcc(refs/vendors/redhat/heads/gcc-9-branch)] libstdc++: Fix regressions in unique_ptr::swap (PR 93562)
Jakub Jelinek
jakub@gcc.gnu.org
Tue Mar 17 19:15:51 GMT 2020
https://gcc.gnu.org/g:30cb4c78ea6563177c43f897e480d9993c38c0ed
commit 30cb4c78ea6563177c43f897e480d9993c38c0ed
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Feb 26 15:04:53 2020 +0000
libstdc++: Fix regressions in unique_ptr::swap (PR 93562)
The requirements for this function are only that the deleter is
swappable, but we incorrectly require that the element type is complete
and that the deleter can be swapped using std::swap (which requires it
to be move cosntructible and move assignable).
The fix is to add __uniq_ptr_impl::swap which swaps the pointer and
deleter individually, instead of using the generic std::swap on the
tuple containing them.
PR libstdc++/93562
* include/bits/unique_ptr.h (__uniq_ptr_impl::swap): Define.
(unique_ptr::swap, unique_ptr<T[], D>::swap): Call it.
* testsuite/20_util/unique_ptr/modifiers/93562.cc: New test.
Diff:
---
libstdc++-v3/ChangeLog | 8 ++
libstdc++-v3/include/bits/unique_ptr.h | 16 +++-
.../20_util/unique_ptr/modifiers/93562.cc | 98 ++++++++++++++++++++++
3 files changed, 118 insertions(+), 4 deletions(-)
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index a94334f8ab1..075442c124a 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,13 @@
2020-02-26 Jonathan Wakely <jwakely@redhat.com>
+ Backport from mainline
+ 2020-02-04 Jonathan Wakely <jwakely@redhat.com>
+
+ PR libstdc++/93562
+ * include/bits/unique_ptr.h (__uniq_ptr_impl::swap): Define.
+ (unique_ptr::swap, unique_ptr<T[], D>::swap): Call it.
+ * testsuite/20_util/unique_ptr/modifiers/93562.cc: New test.
+
Backport from mainline
2020-01-17 Jonathan Wakely <jwakely@redhat.com>
diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h
index d8129747eb5..c934873a722 100644
--- a/libstdc++-v3/include/bits/unique_ptr.h
+++ b/libstdc++-v3/include/bits/unique_ptr.h
@@ -155,6 +155,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Dp& _M_deleter() { return std::get<1>(_M_t); }
const _Dp& _M_deleter() const { return std::get<1>(_M_t); }
+ void
+ swap(__uniq_ptr_impl& __rhs) noexcept
+ {
+ using std::swap;
+ swap(this->_M_ptr(), __rhs._M_ptr());
+ swap(this->_M_deleter(), __rhs._M_deleter());
+ }
+
private:
tuple<pointer, _Dp> _M_t;
};
@@ -398,8 +406,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
swap(unique_ptr& __u) noexcept
{
- using std::swap;
- swap(_M_t, __u._M_t);
+ static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
+ _M_t.swap(__u._M_t);
}
// Disable copy from lvalue.
@@ -673,8 +681,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
swap(unique_ptr& __u) noexcept
{
- using std::swap;
- swap(_M_t, __u._M_t);
+ static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
+ _M_t.swap(__u._M_t);
}
// Disable copy from lvalue.
diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/modifiers/93562.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/modifiers/93562.cc
new file mode 100644
index 00000000000..8ed236333ac
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/unique_ptr/modifiers/93562.cc
@@ -0,0 +1,98 @@
+// Copyright (C) 2020 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 run { target c++11 } }
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+struct incomplete;
+
+// This function isn't called, we just need to check it compiles.
+void
+test01(std::unique_ptr<incomplete>& p1, std::unique_ptr<incomplete>& p2)
+{
+ // PR libstdc++/93562
+ p1.swap(p2);
+ swap(p1, p2);
+}
+
+// This function isn't called, we just need to check it compiles.
+void
+test02(std::unique_ptr<incomplete[]>& p1, std::unique_ptr<incomplete[]>& p2)
+{
+ // PR libstdc++/93562
+ p1.swap(p2);
+ swap(p1, p2);
+}
+
+namespace A
+{
+ struct Deleter
+ {
+ Deleter& operator=(const Deleter&) = delete;
+
+ void operator()(int* p) const noexcept { delete p; }
+
+ // found by ADL
+ friend void swap(Deleter& lhs, Deleter& rhs) noexcept
+ { std::swap(lhs.id, rhs.id); }
+
+ int id;
+ };
+
+ static_assert(!std::is_move_assignable<Deleter>::value, "not assignable");
+#if __cplusplus >= 201703L
+ static_assert(std::is_swappable_v<Deleter>, "but swappable");
+#endif
+} // namespace A
+
+void
+test03()
+{
+ std::unique_ptr<int, A::Deleter> p1(new int(1), { -1 });
+ std::unique_ptr<int, A::Deleter> p2(new int(2), { -2 });
+ int* const pi1 = p1.get();
+ int* const pi2 = p2.get();
+ // This type must swappable even though the deleter is not move-assignable:
+ swap(p1, p2);
+ VERIFY(p1.get() == pi2);
+ VERIFY(p1.get_deleter().id == -2);
+ VERIFY(p2.get() == pi1);
+ VERIFY(p2.get_deleter().id == -1);
+}
+
+void
+test04()
+{
+ std::unique_ptr<int[], A::Deleter> p1(new int[1]{1}, { -1 });
+ std::unique_ptr<int[], A::Deleter> p2(new int[2]{2, 2}, { -2 });
+ int* const pi1 = p1.get();
+ int* const pi2 = p2.get();
+ // This type must swappable even though the deleter is not move-assignable:
+ swap(p1, p2);
+ VERIFY(p1.get() == pi2);
+ VERIFY(p1.get_deleter().id == -2);
+ VERIFY(p2.get() == pi1);
+ VERIFY(p2.get_deleter().id == -1);
+}
+
+int main()
+{
+ test03();
+ test04();
+}
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