libstdc++/69945 Add __gnu_cxx::__freeres hook

	PR libstdc++/69945
	* config/abi/pre/gnu.ver: Add new symbol.
	* libsupc++/eh_alloc.cc (__gnu_cxx::__freeres): Define.
	* testsuite/18_support/free_eh_pool.cc: New test.

From-SVN: r234465

libstdc++-v3/ChangeLog

+2016-03-24  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/69945
+	* config/abi/pre/gnu.ver: Add new symbol.
+	* libsupc++/eh_alloc.cc (__gnu_cxx::__freeres): Define.
+	* testsuite/18_support/free_eh_pool.cc: New test.
+
 2016-03-23  Bernd Edlinger  <bernd.edlinger@hotmail.de>
 
 	* include/Makefile.am (install-freestanding-headers): Add

libstdc++-v3/config/abi/pre/gnu.ver

@@ -2148,6 +2148,8 @@ CXXABI_1.3.10 {
     _ZGTtNKSt13bad_exceptionD1Ev;
     _ZGTtNKSt13bad_exception4whatEv;
 
+    _ZN9__gnu_cxx9__freeresEv;
+
 } CXXABI_1.3.9;
 
 # Symbols in the support library (libsupc++) supporting transactional memory.

libstdc++-v3/libsupc++/eh_alloc.cc

@@ -73,6 +73,10 @@ using namespace __cxxabiv1;
 # define EMERGENCY_OBJ_COUNT	4
 #endif
 
+namespace __gnu_cxx
+{
+  void __freeres();
+}
 
 namespace
 {
@@ -106,6 +110,8 @@ namespace
       // to implement in_pool.
       char *arena;
       std::size_t arena_size;
+
+      friend void __gnu_cxx::__freeres();
     };
 
   pool::pool()
@@ -244,6 +250,19 @@ namespace
   pool emergency_pool;
 }
 
+namespace __gnu_cxx
+{
+  void
+  __freeres()
+  {
+    if (emergency_pool.arena)
+      {
+	::free(emergency_pool.arena);
+	emergency_pool.arena = 0;
+      }
+  }
+}
+
 extern "C" void *
 __cxxabiv1::__cxa_allocate_exception(std::size_t thrown_size) _GLIBCXX_NOTHROW
 {

libstdc++-v3/testsuite/18_support/free_eh_pool.cc

+// Copyright (C) 2016 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 }
+
+namespace __gnu_cxx {
+  void __freeres();
+}
+
+struct X {
+  ~X() {
+    __gnu_cxx::__freeres();
+  }
+};
+
+X x;
+
+int
+main()
+{
+}