1 files changed, 100 insertions, 0 deletions
diff --git a/gdb/user-selection.h b/gdb/user-selection.h
new file mode 100644
index 00000000000..a6f9af30c91
--- /dev/null
+++ b/gdb/user-selection.h
@@ -0,0 +1,100 @@
+#ifndef USER_SELECTION_H
+#define USER_SELECTION_H
+
+class user_selection {
+public:
+
+  /* Default constructor, nothing is selected.  */
+
+  user_selection ()
+  : m_inferior (nullptr),
+    m_thread (nullptr),
+    m_frame_id (null_frame_id),
+    m_frame_level (INVALID_FRAME_LEVEL)
+  {}
+
+  /* Make INF the selected inferior.  If NOTIFY is true, call the observer
+     indicating a selection change.
+
+     Return true if the newly selected inferior is different than the previously
+     selected inferior.  */
+
+  bool select_inferior (struct inferior *inf, bool notify);
+
+  /* Make THREAD the selected thread.  If NOTIFY is true, call the observer
+     indicating a selection change.
+
+     Return true if the newly selected thread is different than the previously
+     selected thread.  */
+
+  bool select_thread (struct thread_info *thread, bool notify);
+
+  /* Make FRAME the selected frame.  If NOTIFY is true, call the observer
+     indicating a selection change.
+
+     Return true if the newly selected frame is different than the previously
+     selected frame.  */
+
+  bool select_frame (struct frame_info *frame, bool notify);
+
+  /* Get the selected inferior.  */
+
+  struct inferior *inferior () const
+  { return m_inferior; }
+
+  /* Get the selected thread.  */
+
+  struct thread_info *thread () const
+  { return m_thread; }
+
+  /* Get the selected frame.  */
+
+  struct frame_info *
+  frame ()
+  {
+    if (!has_valid_frame ())
+      try_select_current_frame ();
+
+    if (!has_valid_frame ())
+      return NULL;
+
+    return frame_find_by_id (m_frame_id);
+  }
+
+  frame_id
+  raw_frame_id () const
+  { return m_frame_id; }
+
+  int
+  raw_frame_level () const
+  { return m_frame_level; }
+
+  bool has_valid_frame () const
+  { return m_frame_level != INVALID_FRAME_LEVEL; }
+
+private:
+
+  struct inferior *m_inferior;
+  struct thread_info *m_thread;
+
+  struct frame_id m_frame_id;
+  int m_frame_level;
+
+  void sanity_check () const;
+  void try_select_current_frame ();
+};
+
+/* Get the global user selection.  */
+
+user_selection *global_user_selection ();
+
+/* Initialize the global user selection.  This must be called after the initial
+   inferior has been created.  */
+
+void init_global_user_selection ();
+
+/* Apply the global user selection to core of gdb.  */
+
+void apply_global_user_selection ();
+
+#endif /* USER_SELECTION_H */