PR libstdc++/83658 fix exception-safety in std::any::emplace

	PR libstdc++/83658
	* include/std/any (any::__do_emplace): Only set _M_manager after
	constructing the contained object.
	* testsuite/20_util/any/misc/any_cast_neg.cc: Adjust dg-error line.
	* testsuite/20_util/any/modifiers/83658.cc: New test.

From-SVN: r257141

libstdc++-v3/ChangeLog

+2018-01-29  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/83658
+	* include/std/any (any::__do_emplace): Only set _M_manager after
+	constructing the contained object.
+	* testsuite/20_util/any/misc/any_cast_neg.cc: Adjust dg-error line.
+	* testsuite/20_util/any/modifiers/83658.cc: New test.
+
 2018-01-25  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/81076

libstdc++-v3/include/std/any

@@ -70,7 +70,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   /**
    *  @brief A type-safe container of any type.
-   * 
+   *
    *  An @c any object's state is either empty or it stores a contained object
    *  of CopyConstructible type.
    */
@@ -114,8 +114,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void __do_emplace(_Args&&... __args)
       {
 	reset();
-	_M_manager = &_Mgr::_S_manage;
         _Mgr::_S_create(_M_storage, std::forward<_Args>(__args)...);
+	_M_manager = &_Mgr::_S_manage;
       }
 
     /// Emplace with an object created from @p __il and @p __args as
@@ -125,8 +125,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void __do_emplace(initializer_list<_Up> __il, _Args&&... __args)
       {
 	reset();
-	_M_manager = &_Mgr::_S_manage;
         _Mgr::_S_create(_M_storage, __il, std::forward<_Args>(__args)...);
+	_M_manager = &_Mgr::_S_manage;
       }
 
   public:
@@ -272,8 +272,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 				   _Decay<_ValueType>, _Args&&...>::type
       emplace(_Args&&... __args)
       {
-	__do_emplace<_Decay<_ValueType>>
-	  (std::forward<_Args>(__args)...);
+	__do_emplace<_Decay<_ValueType>>(std::forward<_Args>(__args)...);
 	any::_Arg __arg;
 	this->_M_manager(any::_Op_access, this, &__arg);
 	return *static_cast<_Decay<_ValueType>*>(__arg._M_obj);
@@ -288,8 +287,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 				   _Args&&...>::type
       emplace(initializer_list<_Up> __il, _Args&&... __args)
       {
-	__do_emplace<_Decay<_ValueType>, _Up>
-	  (__il, std::forward<_Args>(__args)...);
+	__do_emplace<_Decay<_ValueType>, _Up>(__il,
+					      std::forward<_Args>(__args)...);
 	any::_Arg __arg;
 	this->_M_manager(any::_Op_access, this, &__arg);
 	return *static_cast<_Decay<_ValueType>*>(__arg._M_obj);
@@ -624,7 +623,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   /// @}
-  
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 

libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc

@@ -26,5 +26,5 @@ void test01()
   using std::any_cast;
 
   const any y(1);
-  any_cast<int&>(y); // { dg-error "invalid static_cast" "" { target { *-*-* } } 461 }
+  any_cast<int&>(y); // { dg-error "invalid static_cast" "" { target { *-*-* } } 460 }
 }

libstdc++-v3/testsuite/20_util/any/modifiers/83658.cc

+// 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-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+#include <any>
+#include <new>
+#include <testsuite_hooks.h>
+
+struct E : std::bad_alloc { };
+
+struct X
+{
+    X() = default;
+    X(std::initializer_list<int>) { }
+
+    // Prevents small-object optimization:
+    X(const X&) noexcept(false) { }
+
+    static void* operator new(std::size_t) { throw E{}; }
+    static void operator delete(void*, std::size_t) noexcept { }
+};
+
+void
+test01()
+{
+  std::any a;
+  try
+  {
+    a.emplace<X>();
+    VERIFY(false);
+  }
+  catch (const E&)
+  {
+    VERIFY( !a.has_value() );
+  }
+}
+
+void
+test02()
+{
+  std::any a;
+  try
+  {
+    a.emplace<X>(std::initializer_list<int>{});
+    VERIFY(false);
+  }
+  catch (const E&)
+  {
+    VERIFY( !a.has_value() );
+  }
+}
+
+int
+main()
+{
+  test01();
+  test02();
+}