From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: [PATCH] PR libstdc++/87704 fix unique_ptr(nullptr_t) constructors
Date: Tue, 23 Oct 2018 13:41:00 -0000 [thread overview]
Message-ID: <20181023131029.GA4754@redhat.com> (raw)
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Using a delegating constructor to implement these constructors means
that they instantiate the destructor, which requires the element_type to
be complete. In C++11 and C++14 they were specified to be delegating,
but that was changed as part of LWG 2801 so in C++17 they don't require
a complete type (as was intended all along).
PR libstdc++/87704
* include/bits/unique_ptr.h (unique_ptr::unique_ptr(nullptr_t)): Do
not delegate to default constructor.
(unique_ptr<T[], D>::unique_ptr(nullptr_t)): Likewise.
* testsuite/20_util/unique_ptr/cons/incomplete.cc: New test.
Tested powerpc64le-linux, committed to trunk. Backports to follow.
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commit 072315d496bd19a7227213b945652c984ddc4162
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Oct 23 12:40:03 2018 +0100
PR libstdc++/87704 fix unique_ptr(nullptr_t) constructors
Using a delegating constructor to implement these constructors means
that they instantiate the destructor, which requires the element_type to
be complete. In C++11 and C++14 they were specified to be delegating,
but that was changed as part of LWG 2801 so in C++17 they don't require
a complete type (as was intended all along).
PR libstdc++/87704
* include/bits/unique_ptr.h (unique_ptr::unique_ptr(nullptr_t)): Do
not delegate to default constructor.
(unique_ptr<T[], D>::unique_ptr(nullptr_t)): Likewise.
* testsuite/20_util/unique_ptr/cons/incomplete.cc: New test.
diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h
index 0717c1e2728..dcb866d37bc 100644
--- a/libstdc++-v3/include/bits/unique_ptr.h
+++ b/libstdc++-v3/include/bits/unique_ptr.h
@@ -195,7 +195,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
constexpr unique_ptr() noexcept
: _M_t()
- { }
+ { }
/** Takes ownership of a pointer.
*
@@ -244,7 +244,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// Creates a unique_ptr that owns nothing.
template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
- constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
+ constexpr unique_ptr(nullptr_t) noexcept
+ : _M_t()
+ { }
// Move constructors.
@@ -472,7 +474,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
constexpr unique_ptr() noexcept
: _M_t()
- { }
+ { }
/** Takes ownership of a pointer.
*
@@ -535,7 +537,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// Creates a unique_ptr that owns nothing.
template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
- constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
+ constexpr unique_ptr(nullptr_t) noexcept
+ : _M_t()
+ { }
template<typename _Up, typename _Ep,
typename = _Require<__safe_conversion_up<_Up, _Ep>>>
diff --git a/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc
new file mode 100644
index 00000000000..1a8f28838a1
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/unique_ptr/cons/incomplete.cc
@@ -0,0 +1,32 @@
+// Copyright (C) 2018 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 <memory>
+
+struct Incomplete;
+
+void f(void** p)
+{
+ ::new (p[0]) std::unique_ptr<Incomplete>();
+ ::new (p[1]) std::unique_ptr<Incomplete[]>();
+
+ // PR libstdc++/87704
+ ::new (p[2]) std::unique_ptr<Incomplete>(nullptr);
+ ::new (p[3]) std::unique_ptr<Incomplete[]>(nullptr);
+}
next reply other threads:[~2018-10-23 13:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-23 13:41 Jonathan Wakely [this message]
2018-10-25 18:35 ` Jonathan Wakely
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