PR libstdc++/87855 fix optional for types with non-trivial copy/move
When the contained value is not trivially copy (or move) constructible the union's copy (or move) constructor will be deleted, and so the _Optional_payload delegating constructors are invalid. G++ fails to diagnose this because it incorrectly performs copy elision in the delegating constructors. Clang does diagnose it (llvm.org/PR40245). The solution is to avoid performing any copy (or move) when the contained value's copy (or move) constructor isn't trivial. Instead the contained value can be constructed by calling _M_construct. This is OK, because the relevant constructor doesn't need to be constexpr when the contained value isn't trivially copy (or move) constructible. Additionally, this patch removes a lot of code duplication in the _Optional_payload partial specializations and the _Optional_base partial specialization, by hoisting it into common base classes. The Python pretty printer for std::optional needs to be adjusted to support the new layout. Retain support for the old layout, and add a test to verify that the support still works. PR libstdc++/87855 * include/std/optional (_Optional_payload_base): New class template for common code hoisted from _Optional_payload specializations. Use a template for the union, to allow a partial specialization for types with non-trivial destructors. Add constructors for in-place initialization to the union. (_Optional_payload(bool, const _Optional_payload&)): Use _M_construct to perform non-trivial copy construction, instead of relying on non-standard copy elision in a delegating constructor. (_Optional_payload(bool, _Optional_payload&&)): Likewise for non-trivial move construction. (_Optional_payload): Derive from _Optional_payload_base and use it for everything except the non-trivial assignment operators, which are defined as needed. (_Optional_payload<false, C, M>): Derive from the specialization _Optional_payload<true, false, false> and add a destructor. (_Optional_base_impl::_M_destruct, _Optional_base_impl::_M_reset): Forward to corresponding members of _Optional_payload. (_Optional_base_impl::_M_is_engaged, _Optional_base_impl::_M_get): Hoist common members from _Optional_base. (_Optional_base): Make all members and base class public. (_Optional_base::_M_get, _Optional_base::_M_is_engaged): Move to _Optional_base_impl. * python/libstdcxx/v6/printers.py (StdExpOptionalPrinter): Add support for new std::optional layout. * testsuite/libstdc++-prettyprinters/compat.cc: New test. From-SVN: r267742
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2019-01-08 Jonathan Wakely <jwakely@redhat.com>
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2019-01-08 Jonathan Wakely <jwakely@redhat.com>
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PR libstdc++/87855
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* include/std/optional (_Optional_payload_base): New class template
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for common code hoisted from _Optional_payload specializations. Use
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a template for the union, to allow a partial specialization for
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types with non-trivial destructors. Add constructors for in-place
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initialization to the union.
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(_Optional_payload(bool, const _Optional_payload&)): Use _M_construct
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to perform non-trivial copy construction, instead of relying on
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non-standard copy elision in a delegating constructor.
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(_Optional_payload(bool, _Optional_payload&&)): Likewise for
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non-trivial move construction.
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(_Optional_payload): Derive from _Optional_payload_base and use it
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for everything except the non-trivial assignment operators, which are
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defined as needed.
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(_Optional_payload<false, C, M>): Derive from the specialization
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_Optional_payload<true, false, false> and add a destructor.
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(_Optional_base_impl::_M_destruct, _Optional_base_impl::_M_reset):
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Forward to corresponding members of _Optional_payload.
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(_Optional_base_impl::_M_is_engaged, _Optional_base_impl::_M_get):
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Hoist common members from _Optional_base.
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(_Optional_base): Make all members and base class public.
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(_Optional_base::_M_get, _Optional_base::_M_is_engaged): Move to
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_Optional_base_impl.
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* python/libstdcxx/v6/printers.py (StdExpOptionalPrinter): Add
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support for new std::optional layout.
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* testsuite/libstdc++-prettyprinters/compat.cc: New test.
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PR libstdc++/88066
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PR libstdc++/88066
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* include/bits/locale_conv.h: Use <> for includes not "".
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* include/bits/locale_conv.h: Use <> for includes not "".
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* include/ext/random: Likewise.
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* include/ext/random: Likewise.
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File diff suppressed because it is too large
Load Diff
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@ -1093,13 +1093,23 @@ class StdExpOptionalPrinter(SingleObjContainerPrinter):
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def __init__ (self, typename, val):
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def __init__ (self, typename, val):
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valtype = self._recognize (val.type.template_argument(0))
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valtype = self._recognize (val.type.template_argument(0))
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self.typename = strip_versioned_namespace(typename)
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typename = strip_versioned_namespace(typename)
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self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, self.typename, 1)
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self.typename = re.sub('^std::(experimental::|)(fundamentals_v\d::|)(.*)', r'std::\1\3<%s>' % valtype, typename, 1)
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if not self.typename.startswith('std::experimental'):
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payload = val['_M_payload']
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val = val['_M_payload']
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if self.typename.startswith('std::experimental'):
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self.val = val
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engaged = val['_M_engaged']
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contained_value = val['_M_payload'] if self.val['_M_engaged'] else None
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contained_value = payload
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visualizer = gdb.default_visualizer (val['_M_payload'])
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else:
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engaged = payload['_M_engaged']
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contained_value = payload['_M_payload']
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try:
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# Since GCC 9
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contained_value = contained_value['_M_value']
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except:
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pass
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visualizer = gdb.default_visualizer (contained_value)
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if not engaged:
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contained_value = None
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super (StdExpOptionalPrinter, self).__init__ (contained_value, visualizer)
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super (StdExpOptionalPrinter, self).__init__ (contained_value, visualizer)
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def to_string (self):
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def to_string (self):
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@ -0,0 +1,76 @@
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// { dg-options "-g -O0" }
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// { dg-do run }
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// { dg-skip-if "" { *-*-* } { "-D_GLIBCXX_PROFILE" } }
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// Copyright (C) 2014-2019 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License along
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// with this library; see the file COPYING3. If not see
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// <http://www.gnu.org/licenses/>.
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// Test that current printers still support old definitions of types.
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namespace std
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{
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// Old representation of std::optional, before GCC 9
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template<typename T>
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struct _Optional_payload
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{
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_Optional_payload() : _M_empty(), _M_engaged(false) { }
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struct _Empty_byte { };
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union {
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_Empty_byte _M_empty;
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T _M_payload;
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};
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bool _M_engaged;
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};
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template<typename T>
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struct _Optional_base
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{
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_Optional_payload<T> _M_payload;
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};
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template<typename T>
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struct optional : _Optional_base<T>
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{
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optional() { }
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optional(T t)
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{
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this->_M_payload._M_payload = t;
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this->_M_payload._M_engaged = true;
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}
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};
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} // namespace std
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int
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main()
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{
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using std::optional;
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optional<int> o;
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// { dg-final { note-test o {std::optional<int> [no contained value]} } }
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optional<bool> ob{false};
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// { dg-final { note-test ob {std::optional<bool> = {[contained value] = false}} } }
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optional<int> oi{5};
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// { dg-final { note-test oi {std::optional<int> = {[contained value] = 5}} } }
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optional<void*> op{nullptr};
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// { dg-final { note-test op {std::optional<void *> = {[contained value] = 0x0}} } }
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__builtin_puts("");
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return 0; // Mark SPOT
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}
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// { dg-final { gdb-test SPOT } }
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