Move gdbsupport to the top level

[deliverable/binutils-gdb.git] / gdbsupport / refcounted-object.h

diff --git a/gdbsupport/refcounted-object.h b/gdbsupport/refcounted-object.h
new file mode 100644 (file)
index 0000000..95a3127
--- /dev/null
+++ b/gdbsupport/refcounted-object.h
@@ -0,0 +1,70 @@
+/* Base class of intrusively reference-counted objects.
+   Copyright (C) 2017-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program 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 of the License, or
+   (at your option) any later version.
+
+   This program 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 program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef COMMON_REFCOUNTED_OBJECT_H
+#define COMMON_REFCOUNTED_OBJECT_H
+
+/* Base class of intrusively reference-countable objects.
+   Incrementing and decrementing the reference count is an external
+   responsibility.  */
+
+class refcounted_object
+{
+public:
+  refcounted_object () = default;
+
+  /* Increase the refcount.  */
+  void incref ()
+  {
+    gdb_assert (m_refcount >= 0);
+    m_refcount++;
+  }
+
+  /* Decrease the refcount.  */
+  void decref ()
+  {
+    m_refcount--;
+    gdb_assert (m_refcount >= 0);
+  }
+
+  int refcount () const { return m_refcount; }
+
+private:
+  DISABLE_COPY_AND_ASSIGN (refcounted_object);
+
+  /* The reference count.  */
+  int m_refcount = 0;
+};
+
+/* A policy class to interface gdb::ref_ptr with a
+   refcounted_object.  */
+
+struct refcounted_object_ref_policy
+{
+  static void incref (refcounted_object *ptr)
+  {
+    ptr->incref ();
+  }
+
+  static void decref (refcounted_object *ptr)
+  {
+    ptr->decref ();
+  }
+};
+
+#endif /* COMMON_REFCOUNTED_OBJECT_H */