Support C++11 thread_local destructors.

gcc/cp/
	* decl.c (get_thread_atexit_node): New.
	(register_dtor_fn): Use it for TLS.
libstdc++-v3/
	* libsupc++/cxxabi.h: Declare __cxa_thread_atexit.
	* libsupc++/atexit_thread.cc: New.
	* libsupc++/Makefile.am (nested_exception.lo): Add it.
	* config/abi/pre/gnu.ver: Add __cxa_thread_atexit.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@192210 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 135 insertions, 0 deletions

diff --git a/libstdc++-v3/libsupc++/atexit_thread.cc b/libstdc++-v3/libsupc++/atexit_thread.cc
new file mode 100644
index 00000000000..5e47708d934
--- /dev/null
+++ b/libstdc++-v3/libsupc++/atexit_thread.cc
@@ -0,0 +1,135 @@
+// Copyright (C) 2012 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC 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.
+
+// GCC 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#include <cxxabi.h>
+#include <cstdlib>
+#include <new>
+#include "bits/gthr.h"
+
+namespace {
+  // Data structure for the list of destructors: Singly-linked list
+  // of arrays.
+  class list
+  {
+    struct elt
+    {
+      void *object;
+      void (*destructor)(void *);
+    };
+
+    static const int max_nelts = 32;
+
+    list *next;
+    int nelts;
+    elt array[max_nelts];
+
+    elt *allocate_elt();
+  public:
+    void run();
+    static void run(void *p);
+    int add_elt(void (*)(void *), void *);
+  };
+
+  // Return the address of an open slot.
+  list::elt *
+  list::allocate_elt()
+  {
+    if (nelts < max_nelts)
+      return &array[nelts++];
+    if (!next)
+      next = new (std::nothrow) list();
+    if (!next)
+      return 0;
+    return next->allocate_elt();
+  }
+
+  // Run all the cleanups in the list.
+  void
+  list::run()
+  {
+    for (int i = nelts - 1; i >= 0; --i)
+      array[i].destructor (array[i].object);
+    if (next)
+      next->run();
+  }
+
+  // Static version to use as a callback to __gthread_key_create.
+  void
+  list::run(void *p)
+  {
+    static_cast<list *>(p)->run();
+  }
+
+  // The list of cleanups is per-thread.
+  thread_local list first;
+
+  // The pthread data structures for actually running the destructors at
+  // thread exit are shared.  The constructor of the thread-local sentinel
+  // object in add_elt performs the initialization.
+  __gthread_key_t key;
+  __gthread_once_t once = __GTHREAD_ONCE_INIT;
+  void run_current () { first.run(); }
+  void key_init() {
+    __gthread_key_create (&key, list::run);
+    // Also make sure the destructors are run by std::exit.
+    // FIXME TLS cleanups should run before static cleanups and atexit
+    // cleanups.
+    std::atexit (run_current);
+  }
+  struct sentinel
+  {
+    sentinel()
+    {
+      if (__gthread_active_p ())
+	{
+	  __gthread_once (&once, key_init);
+	  __gthread_setspecific (key, &first);
+	}
+      else
+	std::atexit (run_current);
+    }
+  };
+
+  // Actually insert an element.
+  int
+  list::add_elt(void (*dtor)(void *), void *obj)
+  {
+    thread_local sentinel s;
+    elt *e = allocate_elt ();
+    if (!e)
+      return -1;
+    e->object = obj;
+    e->destructor = dtor;
+    return 0;
+  }
+}
+
+namespace __cxxabiv1
+{
+  extern "C" int
+  __cxa_thread_atexit (void (*dtor)(void *), void *obj, void */*dso_handle*/)
+    _GLIBCXX_NOTHROW
+  {
+    return first.add_elt (dtor, obj);
+  }
+}